/* Fold a constant sub-tree into a single node for C-compiler
- Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
- 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
+ Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
+ 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
+ Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
-Software Foundation; either version 2, or (at your option) any later
+Software Foundation; either version 3, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
for more details.
You should have received a copy of the GNU General Public License
-along with GCC; see the file COPYING. If not, write to the Free
-Software Foundation, 59 Temple Place - Suite 330, Boston, MA
-02111-1307, USA. */
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
/*@@ This file should be rewritten to use an arbitrary precision
@@ representation for "struct tree_int_cst" and "struct tree_real_cst".
@@ for cross-compilers. */
/* The entry points in this file are fold, size_int_wide, size_binop
- and force_fit_type.
+ and force_fit_type_double.
fold takes a tree as argument and returns a simplified tree.
size_int takes an integer value, and creates a tree constant
with type from `sizetype'.
- force_fit_type takes a constant and prior overflow indicator, and
- forces the value to fit the type. It returns an overflow indicator. */
+ force_fit_type_double takes a constant, an overflowable flag and a
+ prior overflow indicator. It forces the value to fit the type and
+ sets TREE_OVERFLOW.
+
+ Note: Since the folders get called on non-gimple code as well as
+ gimple code, we need to handle GIMPLE tuples as well as their
+ corresponding tree equivalents. */
#include "config.h"
#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
#include "flags.h"
#include "tree.h"
+#include "real.h"
+#include "fixed-value.h"
#include "rtl.h"
#include "expr.h"
#include "tm_p.h"
+#include "target.h"
#include "toplev.h"
+#include "intl.h"
#include "ggc.h"
#include "hashtab.h"
+#include "langhooks.h"
+#include "md5.h"
+#include "gimple.h"
+
+/* Nonzero if we are folding constants inside an initializer; zero
+ otherwise. */
+int folding_initializer = 0;
+
+/* The following constants represent a bit based encoding of GCC's
+ comparison operators. This encoding simplifies transformations
+ on relational comparison operators, such as AND and OR. */
+enum comparison_code {
+ COMPCODE_FALSE = 0,
+ COMPCODE_LT = 1,
+ COMPCODE_EQ = 2,
+ COMPCODE_LE = 3,
+ COMPCODE_GT = 4,
+ COMPCODE_LTGT = 5,
+ COMPCODE_GE = 6,
+ COMPCODE_ORD = 7,
+ COMPCODE_UNORD = 8,
+ COMPCODE_UNLT = 9,
+ COMPCODE_UNEQ = 10,
+ COMPCODE_UNLE = 11,
+ COMPCODE_UNGT = 12,
+ COMPCODE_NE = 13,
+ COMPCODE_UNGE = 14,
+ COMPCODE_TRUE = 15
+};
+
+static void encode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT, HOST_WIDE_INT);
+static void decode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
+static bool negate_mathfn_p (enum built_in_function);
+static bool negate_expr_p (tree);
+static tree negate_expr (tree);
+static tree split_tree (tree, enum tree_code, tree *, tree *, tree *, int);
+static tree associate_trees (tree, tree, enum tree_code, tree);
+static tree const_binop (enum tree_code, tree, tree, int);
+static enum comparison_code comparison_to_compcode (enum tree_code);
+static enum tree_code compcode_to_comparison (enum comparison_code);
+static tree combine_comparisons (enum tree_code, enum tree_code,
+ enum tree_code, tree, tree, tree);
+static int operand_equal_for_comparison_p (tree, tree, tree);
+static int twoval_comparison_p (tree, tree *, tree *, int *);
+static tree eval_subst (tree, tree, tree, tree, tree);
+static tree pedantic_omit_one_operand (tree, tree, tree);
+static tree distribute_bit_expr (enum tree_code, tree, tree, tree);
+static tree make_bit_field_ref (tree, tree, HOST_WIDE_INT, HOST_WIDE_INT, int);
+static tree optimize_bit_field_compare (enum tree_code, tree, tree, tree);
+static tree decode_field_reference (tree, HOST_WIDE_INT *, HOST_WIDE_INT *,
+ enum machine_mode *, int *, int *,
+ tree *, tree *);
+static int all_ones_mask_p (const_tree, int);
+static tree sign_bit_p (tree, const_tree);
+static int simple_operand_p (const_tree);
+static tree range_binop (enum tree_code, tree, tree, int, tree, int);
+static tree range_predecessor (tree);
+static tree range_successor (tree);
+static tree make_range (tree, int *, tree *, tree *, bool *);
+static tree build_range_check (tree, tree, int, tree, tree);
+static int merge_ranges (int *, tree *, tree *, int, tree, tree, int, tree,
+ tree);
+static tree fold_range_test (enum tree_code, tree, tree, tree);
+static tree fold_cond_expr_with_comparison (tree, tree, tree, tree);
+static tree unextend (tree, int, int, tree);
+static tree fold_truthop (enum tree_code, tree, tree, tree);
+static tree optimize_minmax_comparison (enum tree_code, tree, tree, tree);
+static tree extract_muldiv (tree, tree, enum tree_code, tree, bool *);
+static tree extract_muldiv_1 (tree, tree, enum tree_code, tree, bool *);
+static tree fold_binary_op_with_conditional_arg (enum tree_code, tree,
+ tree, tree,
+ tree, tree, int);
+static tree fold_mathfn_compare (enum built_in_function, enum tree_code,
+ tree, tree, tree);
+static tree fold_inf_compare (enum tree_code, tree, tree, tree);
+static tree fold_div_compare (enum tree_code, tree, tree, tree);
+static bool reorder_operands_p (const_tree, const_tree);
+static tree fold_negate_const (tree, tree);
+static tree fold_not_const (tree, tree);
+static tree fold_relational_const (enum tree_code, tree, tree, tree);
-static void encode PARAMS ((HOST_WIDE_INT *,
- unsigned HOST_WIDE_INT,
- HOST_WIDE_INT));
-static void decode PARAMS ((HOST_WIDE_INT *,
- unsigned HOST_WIDE_INT *,
- HOST_WIDE_INT *));
-#ifndef REAL_ARITHMETIC
-static void exact_real_inverse_1 PARAMS ((PTR));
-#endif
-static tree negate_expr PARAMS ((tree));
-static tree split_tree PARAMS ((tree, enum tree_code, tree *, tree *,
- tree *, int));
-static tree associate_trees PARAMS ((tree, tree, enum tree_code, tree));
-static tree int_const_binop PARAMS ((enum tree_code, tree, tree, int));
-static void const_binop_1 PARAMS ((PTR));
-static tree const_binop PARAMS ((enum tree_code, tree, tree, int));
-static hashval_t size_htab_hash PARAMS ((const void *));
-static int size_htab_eq PARAMS ((const void *, const void *));
-static void fold_convert_1 PARAMS ((PTR));
-static tree fold_convert PARAMS ((tree, tree));
-static enum tree_code invert_tree_comparison PARAMS ((enum tree_code));
-static enum tree_code swap_tree_comparison PARAMS ((enum tree_code));
-static int truth_value_p PARAMS ((enum tree_code));
-static int operand_equal_for_comparison_p PARAMS ((tree, tree, tree));
-static int twoval_comparison_p PARAMS ((tree, tree *, tree *, int *));
-static tree eval_subst PARAMS ((tree, tree, tree, tree, tree));
-static tree omit_one_operand PARAMS ((tree, tree, tree));
-static tree pedantic_omit_one_operand PARAMS ((tree, tree, tree));
-static tree distribute_bit_expr PARAMS ((enum tree_code, tree, tree, tree));
-static tree make_bit_field_ref PARAMS ((tree, tree, int, int, int));
-static tree optimize_bit_field_compare PARAMS ((enum tree_code, tree,
- tree, tree));
-static tree decode_field_reference PARAMS ((tree, HOST_WIDE_INT *,
- HOST_WIDE_INT *,
- enum machine_mode *, int *,
- int *, tree *, tree *));
-static int all_ones_mask_p PARAMS ((tree, int));
-static int simple_operand_p PARAMS ((tree));
-static tree range_binop PARAMS ((enum tree_code, tree, tree, int,
- tree, int));
-static tree make_range PARAMS ((tree, int *, tree *, tree *));
-static tree build_range_check PARAMS ((tree, tree, int, tree, tree));
-static int merge_ranges PARAMS ((int *, tree *, tree *, int, tree, tree,
- int, tree, tree));
-static tree fold_range_test PARAMS ((tree));
-static tree unextend PARAMS ((tree, int, int, tree));
-static tree fold_truthop PARAMS ((enum tree_code, tree, tree, tree));
-static tree optimize_minmax_comparison PARAMS ((tree));
-static tree extract_muldiv PARAMS ((tree, tree, enum tree_code, tree));
-static tree extract_muldiv_1 PARAMS ((tree, tree, enum tree_code, tree));
-static tree strip_compound_expr PARAMS ((tree, tree));
-static int multiple_of_p PARAMS ((tree, tree, tree));
-static tree constant_boolean_node PARAMS ((int, tree));
-static int count_cond PARAMS ((tree, int));
-static tree fold_binary_op_with_conditional_arg
- PARAMS ((enum tree_code, tree, tree, tree, int));
-
-#if defined(HOST_EBCDIC)
-/* bit 8 is significant in EBCDIC */
-#define CHARMASK 0xff
-#else
-#define CHARMASK 0x7f
-#endif
/* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
WORDS points to the array of HOST_WIDE_INTs. */
static void
-encode (words, low, hi)
- HOST_WIDE_INT *words;
- unsigned HOST_WIDE_INT low;
- HOST_WIDE_INT hi;
+encode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT low, HOST_WIDE_INT hi)
{
words[0] = LOWPART (low);
words[1] = HIGHPART (low);
The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
static void
-decode (words, low, hi)
- HOST_WIDE_INT *words;
- unsigned HOST_WIDE_INT *low;
- HOST_WIDE_INT *hi;
+decode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT *low,
+ HOST_WIDE_INT *hi)
{
*low = words[0] + words[1] * BASE;
*hi = words[2] + words[3] * BASE;
}
\f
-/* Make the integer constant T valid for its type by setting to 0 or 1 all
- the bits in the constant that don't belong in the type.
-
- Return 1 if a signed overflow occurs, 0 otherwise. If OVERFLOW is
- nonzero, a signed overflow has already occurred in calculating T, so
- propagate it.
-
- Make the real constant T valid for its type by calling CHECK_FLOAT_VALUE,
- if it exists. */
+/* Force the double-word integer L1, H1 to be within the range of the
+ integer type TYPE. Stores the properly truncated and sign-extended
+ double-word integer in *LV, *HV. Returns true if the operation
+ overflows, that is, argument and result are different. */
int
-force_fit_type (t, overflow)
- tree t;
- int overflow;
+fit_double_type (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
+ unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, const_tree type)
{
- unsigned HOST_WIDE_INT low;
- HOST_WIDE_INT high;
+ unsigned HOST_WIDE_INT low0 = l1;
+ HOST_WIDE_INT high0 = h1;
unsigned int prec;
+ int sign_extended_type;
- if (TREE_CODE (t) == REAL_CST)
- {
-#ifdef CHECK_FLOAT_VALUE
- CHECK_FLOAT_VALUE (TYPE_MODE (TREE_TYPE (t)), TREE_REAL_CST (t),
- overflow);
-#endif
- return overflow;
- }
-
- else if (TREE_CODE (t) != INTEGER_CST)
- return overflow;
-
- low = TREE_INT_CST_LOW (t);
- high = TREE_INT_CST_HIGH (t);
-
- if (POINTER_TYPE_P (TREE_TYPE (t)))
+ if (POINTER_TYPE_P (type)
+ || TREE_CODE (type) == OFFSET_TYPE)
prec = POINTER_SIZE;
else
- prec = TYPE_PRECISION (TREE_TYPE (t));
+ prec = TYPE_PRECISION (type);
- /* First clear all bits that are beyond the type's precision. */
+ /* Size types *are* sign extended. */
+ sign_extended_type = (!TYPE_UNSIGNED (type)
+ || (TREE_CODE (type) == INTEGER_TYPE
+ && TYPE_IS_SIZETYPE (type)));
- if (prec == 2 * HOST_BITS_PER_WIDE_INT)
+ /* First clear all bits that are beyond the type's precision. */
+ if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
;
else if (prec > HOST_BITS_PER_WIDE_INT)
- TREE_INT_CST_HIGH (t)
- &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
+ h1 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
else
{
- TREE_INT_CST_HIGH (t) = 0;
+ h1 = 0;
if (prec < HOST_BITS_PER_WIDE_INT)
- TREE_INT_CST_LOW (t) &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
- }
-
- /* Unsigned types do not suffer sign extension or overflow unless they
- are a sizetype. */
- if (TREE_UNSIGNED (TREE_TYPE (t))
- && ! (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
- && TYPE_IS_SIZETYPE (TREE_TYPE (t))))
- return overflow;
-
- /* If the value's sign bit is set, extend the sign. */
- if (prec != 2 * HOST_BITS_PER_WIDE_INT
- && (prec > HOST_BITS_PER_WIDE_INT
- ? 0 != (TREE_INT_CST_HIGH (t)
- & ((HOST_WIDE_INT) 1
- << (prec - HOST_BITS_PER_WIDE_INT - 1)))
- : 0 != (TREE_INT_CST_LOW (t)
- & ((unsigned HOST_WIDE_INT) 1 << (prec - 1)))))
- {
- /* Value is negative:
- set to 1 all the bits that are outside this type's precision. */
- if (prec > HOST_BITS_PER_WIDE_INT)
- TREE_INT_CST_HIGH (t)
- |= ((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
- else
+ l1 &= ~((HOST_WIDE_INT) (-1) << prec);
+ }
+
+ /* Then do sign extension if necessary. */
+ if (!sign_extended_type)
+ /* No sign extension */;
+ else if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
+ /* Correct width already. */;
+ else if (prec > HOST_BITS_PER_WIDE_INT)
+ {
+ /* Sign extend top half? */
+ if (h1 & ((unsigned HOST_WIDE_INT)1
+ << (prec - HOST_BITS_PER_WIDE_INT - 1)))
+ h1 |= (HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT);
+ }
+ else if (prec == HOST_BITS_PER_WIDE_INT)
+ {
+ if ((HOST_WIDE_INT)l1 < 0)
+ h1 = -1;
+ }
+ else
+ {
+ /* Sign extend bottom half? */
+ if (l1 & ((unsigned HOST_WIDE_INT)1 << (prec - 1)))
{
- TREE_INT_CST_HIGH (t) = -1;
- if (prec < HOST_BITS_PER_WIDE_INT)
- TREE_INT_CST_LOW (t) |= ((unsigned HOST_WIDE_INT) (-1) << prec);
+ h1 = -1;
+ l1 |= (HOST_WIDE_INT)(-1) << prec;
}
}
- /* Return nonzero if signed overflow occurred. */
- return
- ((overflow | (low ^ TREE_INT_CST_LOW (t)) | (high ^ TREE_INT_CST_HIGH (t)))
- != 0);
+ *lv = l1;
+ *hv = h1;
+
+ /* If the value didn't fit, signal overflow. */
+ return l1 != low0 || h1 != high0;
+}
+
+/* We force the double-int HIGH:LOW to the range of the type TYPE by
+ sign or zero extending it.
+ OVERFLOWABLE indicates if we are interested
+ in overflow of the value, when >0 we are only interested in signed
+ overflow, for <0 we are interested in any overflow. OVERFLOWED
+ indicates whether overflow has already occurred. CONST_OVERFLOWED
+ indicates whether constant overflow has already occurred. We force
+ T's value to be within range of T's type (by setting to 0 or 1 all
+ the bits outside the type's range). We set TREE_OVERFLOWED if,
+ OVERFLOWED is nonzero,
+ or OVERFLOWABLE is >0 and signed overflow occurs
+ or OVERFLOWABLE is <0 and any overflow occurs
+ We return a new tree node for the extended double-int. The node
+ is shared if no overflow flags are set. */
+
+tree
+force_fit_type_double (tree type, unsigned HOST_WIDE_INT low,
+ HOST_WIDE_INT high, int overflowable,
+ bool overflowed)
+{
+ int sign_extended_type;
+ bool overflow;
+
+ /* Size types *are* sign extended. */
+ sign_extended_type = (!TYPE_UNSIGNED (type)
+ || (TREE_CODE (type) == INTEGER_TYPE
+ && TYPE_IS_SIZETYPE (type)));
+
+ overflow = fit_double_type (low, high, &low, &high, type);
+
+ /* If we need to set overflow flags, return a new unshared node. */
+ if (overflowed || overflow)
+ {
+ if (overflowed
+ || overflowable < 0
+ || (overflowable > 0 && sign_extended_type))
+ {
+ tree t = make_node (INTEGER_CST);
+ TREE_INT_CST_LOW (t) = low;
+ TREE_INT_CST_HIGH (t) = high;
+ TREE_TYPE (t) = type;
+ TREE_OVERFLOW (t) = 1;
+ return t;
+ }
+ }
+
+ /* Else build a shared node. */
+ return build_int_cst_wide (type, low, high);
}
\f
/* Add two doubleword integers with doubleword result.
+ Return nonzero if the operation overflows according to UNSIGNED_P.
Each argument is given as two `HOST_WIDE_INT' pieces.
One argument is L1 and H1; the other, L2 and H2.
The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
int
-add_double (l1, h1, l2, h2, lv, hv)
- unsigned HOST_WIDE_INT l1, l2;
- HOST_WIDE_INT h1, h2;
- unsigned HOST_WIDE_INT *lv;
- HOST_WIDE_INT *hv;
+add_double_with_sign (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
+ unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
+ unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
+ bool unsigned_p)
{
unsigned HOST_WIDE_INT l;
HOST_WIDE_INT h;
l = l1 + l2;
- h = h1 + h2 + (l < l1);
+ h = (HOST_WIDE_INT) ((unsigned HOST_WIDE_INT) h1
+ + (unsigned HOST_WIDE_INT) h2
+ + (l < l1));
*lv = l;
*hv = h;
- return OVERFLOW_SUM_SIGN (h1, h2, h);
+
+ if (unsigned_p)
+ return ((unsigned HOST_WIDE_INT) h < (unsigned HOST_WIDE_INT) h1
+ || (h == h1
+ && l < l1));
+ else
+ return OVERFLOW_SUM_SIGN (h1, h2, h);
}
/* Negate a doubleword integer with doubleword result.
The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
int
-neg_double (l1, h1, lv, hv)
- unsigned HOST_WIDE_INT l1;
- HOST_WIDE_INT h1;
- unsigned HOST_WIDE_INT *lv;
- HOST_WIDE_INT *hv;
+neg_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
+ unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
{
if (l1 == 0)
{
}
\f
/* Multiply two doubleword integers with doubleword result.
- Return nonzero if the operation overflows, assuming it's signed.
+ Return nonzero if the operation overflows according to UNSIGNED_P.
Each argument is given as two `HOST_WIDE_INT' pieces.
One argument is L1 and H1; the other, L2 and H2.
The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
int
-mul_double (l1, h1, l2, h2, lv, hv)
- unsigned HOST_WIDE_INT l1, l2;
- HOST_WIDE_INT h1, h2;
- unsigned HOST_WIDE_INT *lv;
- HOST_WIDE_INT *hv;
+mul_double_with_sign (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
+ unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
+ unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
+ bool unsigned_p)
{
HOST_WIDE_INT arg1[4];
HOST_WIDE_INT arg2[4];
encode (arg1, l1, h1);
encode (arg2, l2, h2);
- memset ((char *) prod, 0, sizeof prod);
+ memset (prod, 0, sizeof prod);
for (i = 0; i < 4; i++)
{
prod[i + 4] = carry;
}
- decode (prod, lv, hv); /* This ignores prod[4] through prod[4*2-1] */
-
- /* Check for overflow by calculating the top half of the answer in full;
- it should agree with the low half's sign bit. */
+ decode (prod, lv, hv);
decode (prod + 4, &toplow, &tophigh);
+
+ /* Unsigned overflow is immediate. */
+ if (unsigned_p)
+ return (toplow | tophigh) != 0;
+
+ /* Check for signed overflow by calculating the signed representation of the
+ top half of the result; it should agree with the low half's sign bit. */
if (h1 < 0)
{
neg_double (l2, h2, &neglow, &neghigh);
Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
void
-lshift_double (l1, h1, count, prec, lv, hv, arith)
- unsigned HOST_WIDE_INT l1;
- HOST_WIDE_INT h1, count;
- unsigned int prec;
- unsigned HOST_WIDE_INT *lv;
- HOST_WIDE_INT *hv;
- int arith;
+lshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
+ HOST_WIDE_INT count, unsigned int prec,
+ unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, int arith)
{
unsigned HOST_WIDE_INT signmask;
return;
}
-#ifdef SHIFT_COUNT_TRUNCATED
if (SHIFT_COUNT_TRUNCATED)
count %= prec;
-#endif
if (count >= 2 * HOST_BITS_PER_WIDE_INT)
{
/* Sign extend all bits that are beyond the precision. */
signmask = -((prec > HOST_BITS_PER_WIDE_INT
- ? (*hv >> (prec - HOST_BITS_PER_WIDE_INT - 1))
+ ? ((unsigned HOST_WIDE_INT) *hv
+ >> (prec - HOST_BITS_PER_WIDE_INT - 1))
: (*lv >> (prec - 1))) & 1);
if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
void
-rshift_double (l1, h1, count, prec, lv, hv, arith)
- unsigned HOST_WIDE_INT l1;
- HOST_WIDE_INT h1, count;
- unsigned int prec;
- unsigned HOST_WIDE_INT *lv;
- HOST_WIDE_INT *hv;
- int arith;
+rshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
+ HOST_WIDE_INT count, unsigned int prec,
+ unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
+ int arith)
{
unsigned HOST_WIDE_INT signmask;
? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
: 0);
-#ifdef SHIFT_COUNT_TRUNCATED
if (SHIFT_COUNT_TRUNCATED)
count %= prec;
-#endif
if (count >= 2 * HOST_BITS_PER_WIDE_INT)
{
Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
void
-lrotate_double (l1, h1, count, prec, lv, hv)
- unsigned HOST_WIDE_INT l1;
- HOST_WIDE_INT h1, count;
- unsigned int prec;
- unsigned HOST_WIDE_INT *lv;
- HOST_WIDE_INT *hv;
+lrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
+ HOST_WIDE_INT count, unsigned int prec,
+ unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
{
unsigned HOST_WIDE_INT s1l, s2l;
HOST_WIDE_INT s1h, s2h;
Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
void
-rrotate_double (l1, h1, count, prec, lv, hv)
- unsigned HOST_WIDE_INT l1;
- HOST_WIDE_INT h1, count;
- unsigned int prec;
- unsigned HOST_WIDE_INT *lv;
- HOST_WIDE_INT *hv;
+rrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
+ HOST_WIDE_INT count, unsigned int prec,
+ unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
{
unsigned HOST_WIDE_INT s1l, s2l;
HOST_WIDE_INT s1h, s2h;
UNS nonzero says do unsigned division. */
int
-div_and_round_double (code, uns,
- lnum_orig, hnum_orig, lden_orig, hden_orig,
- lquo, hquo, lrem, hrem)
- enum tree_code code;
- int uns;
- unsigned HOST_WIDE_INT lnum_orig; /* num == numerator == dividend */
- HOST_WIDE_INT hnum_orig;
- unsigned HOST_WIDE_INT lden_orig; /* den == denominator == divisor */
- HOST_WIDE_INT hden_orig;
- unsigned HOST_WIDE_INT *lquo, *lrem;
- HOST_WIDE_INT *hquo, *hrem;
+div_and_round_double (enum tree_code code, int uns,
+ unsigned HOST_WIDE_INT lnum_orig, /* num == numerator == dividend */
+ HOST_WIDE_INT hnum_orig,
+ unsigned HOST_WIDE_INT lden_orig, /* den == denominator == divisor */
+ HOST_WIDE_INT hden_orig,
+ unsigned HOST_WIDE_INT *lquo,
+ HOST_WIDE_INT *hquo, unsigned HOST_WIDE_INT *lrem,
+ HOST_WIDE_INT *hrem)
{
int quo_neg = 0;
HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
if (hden == 0 && lden == 0)
overflow = 1, lden = 1;
- /* calculate quotient sign and convert operands to unsigned. */
+ /* Calculate quotient sign and convert operands to unsigned. */
if (!uns)
{
if (hnum < 0)
goto finish_up;
}
- memset ((char *) quo, 0, sizeof quo);
+ memset (quo, 0, sizeof quo);
- memset ((char *) num, 0, sizeof num); /* to zero 9th element */
- memset ((char *) den, 0, sizeof den);
+ memset (num, 0, sizeof num); /* to zero 9th element */
+ memset (den, 0, sizeof den);
encode (num, lnum, hnum);
encode (den, lden, hden);
int num_hi_sig, den_hi_sig;
unsigned HOST_WIDE_INT quo_est, scale;
- /* Find the highest non-zero divisor digit. */
+ /* Find the highest nonzero divisor digit. */
for (i = 4 - 1;; i--)
if (den[i] != 0)
{
/* If quo_est was high by one, then num[i] went negative and
we need to correct things. */
- if (num[num_hi_sig] < carry)
+ if (num[num_hi_sig] < (HOST_WIDE_INT) carry)
{
quo_est--;
carry = 0; /* add divisor back in */
decode (quo, lquo, hquo);
finish_up:
- /* if result is negative, make it so. */
+ /* If result is negative, make it so. */
if (quo_neg)
neg_double (*lquo, *hquo, lquo, hquo);
- /* compute trial remainder: rem = num - (quo * den) */
+ /* Compute trial remainder: rem = num - (quo * den) */
mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
neg_double (*lrem, *hrem, lrem, hrem);
add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
unsigned HOST_WIDE_INT labs_den = lden, ltwice;
HOST_WIDE_INT habs_den = hden, htwice;
- /* Get absolute values */
+ /* Get absolute values. */
if (*hrem < 0)
neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
if (hden < 0)
neg_double (lden, hden, &labs_den, &habs_den);
- /* If (2 * abs (lrem) >= abs (lden)) */
+ /* If (2 * abs (lrem) >= abs (lden)), adjust the quotient. */
mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
labs_rem, habs_rem, <wice, &htwice);
< (unsigned HOST_WIDE_INT) htwice)
|| (((unsigned HOST_WIDE_INT) habs_den
== (unsigned HOST_WIDE_INT) htwice)
- && (labs_den < ltwice)))
+ && (labs_den <= ltwice)))
{
if (*hquo < 0)
/* quo = quo - 1; */
break;
default:
- abort ();
+ gcc_unreachable ();
}
- /* compute true remainder: rem = num - (quo * den) */
+ /* Compute true remainder: rem = num - (quo * den) */
mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
neg_double (*lrem, *hrem, lrem, hrem);
add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
return overflow;
}
-\f
-#ifndef REAL_ARITHMETIC
-/* Effectively truncate a real value to represent the nearest possible value
- in a narrower mode. The result is actually represented in the same data
- type as the argument, but its value is usually different.
- A trap may occur during the FP operations and it is the responsibility
- of the calling function to have a handler established. */
+/* If ARG2 divides ARG1 with zero remainder, carries out the division
+ of type CODE and returns the quotient.
+ Otherwise returns NULL_TREE. */
-REAL_VALUE_TYPE
-real_value_truncate (mode, arg)
- enum machine_mode mode;
- REAL_VALUE_TYPE arg;
+static tree
+div_if_zero_remainder (enum tree_code code, const_tree arg1, const_tree arg2)
{
- return REAL_VALUE_TRUNCATE (mode, arg);
-}
-
-#if TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
-
-/* Check for infinity in an IEEE double precision number. */
+ unsigned HOST_WIDE_INT int1l, int2l;
+ HOST_WIDE_INT int1h, int2h;
+ unsigned HOST_WIDE_INT quol, reml;
+ HOST_WIDE_INT quoh, remh;
+ tree type = TREE_TYPE (arg1);
+ int uns = TYPE_UNSIGNED (type);
-int
-target_isinf (x)
- REAL_VALUE_TYPE x;
-{
- /* The IEEE 64-bit double format. */
- union {
- REAL_VALUE_TYPE d;
- struct {
- unsigned sign : 1;
- unsigned exponent : 11;
- unsigned mantissa1 : 20;
- unsigned mantissa2 : 32;
- } little_endian;
- struct {
- unsigned mantissa2 : 32;
- unsigned mantissa1 : 20;
- unsigned exponent : 11;
- unsigned sign : 1;
- } big_endian;
- } u;
-
- u.d = dconstm1;
- if (u.big_endian.sign == 1)
- {
- u.d = x;
- return (u.big_endian.exponent == 2047
- && u.big_endian.mantissa1 == 0
- && u.big_endian.mantissa2 == 0);
- }
- else
+ int1l = TREE_INT_CST_LOW (arg1);
+ int1h = TREE_INT_CST_HIGH (arg1);
+ /* &obj[0] + -128 really should be compiled as &obj[-8] rather than
+ &obj[some_exotic_number]. */
+ if (POINTER_TYPE_P (type))
{
- u.d = x;
- return (u.little_endian.exponent == 2047
- && u.little_endian.mantissa1 == 0
- && u.little_endian.mantissa2 == 0);
- }
-}
-
-/* Check whether an IEEE double precision number is a NaN. */
-
-int
-target_isnan (x)
- REAL_VALUE_TYPE x;
-{
- /* The IEEE 64-bit double format. */
- union {
- REAL_VALUE_TYPE d;
- struct {
- unsigned sign : 1;
- unsigned exponent : 11;
- unsigned mantissa1 : 20;
- unsigned mantissa2 : 32;
- } little_endian;
- struct {
- unsigned mantissa2 : 32;
- unsigned mantissa1 : 20;
- unsigned exponent : 11;
- unsigned sign : 1;
- } big_endian;
- } u;
-
- u.d = dconstm1;
- if (u.big_endian.sign == 1)
- {
- u.d = x;
- return (u.big_endian.exponent == 2047
- && (u.big_endian.mantissa1 != 0
- || u.big_endian.mantissa2 != 0));
+ uns = false;
+ type = signed_type_for (type);
+ fit_double_type (int1l, int1h, &int1l, &int1h,
+ type);
}
else
- {
- u.d = x;
- return (u.little_endian.exponent == 2047
- && (u.little_endian.mantissa1 != 0
- || u.little_endian.mantissa2 != 0));
- }
-}
+ fit_double_type (int1l, int1h, &int1l, &int1h, type);
+ int2l = TREE_INT_CST_LOW (arg2);
+ int2h = TREE_INT_CST_HIGH (arg2);
-/* Check for a negative IEEE double precision number. */
+ div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
+ &quol, &quoh, &reml, &remh);
+ if (remh != 0 || reml != 0)
+ return NULL_TREE;
-int
-target_negative (x)
- REAL_VALUE_TYPE x;
-{
- /* The IEEE 64-bit double format. */
- union {
- REAL_VALUE_TYPE d;
- struct {
- unsigned sign : 1;
- unsigned exponent : 11;
- unsigned mantissa1 : 20;
- unsigned mantissa2 : 32;
- } little_endian;
- struct {
- unsigned mantissa2 : 32;
- unsigned mantissa1 : 20;
- unsigned exponent : 11;
- unsigned sign : 1;
- } big_endian;
- } u;
-
- u.d = dconstm1;
- if (u.big_endian.sign == 1)
- {
- u.d = x;
- return u.big_endian.sign;
- }
- else
- {
- u.d = x;
- return u.little_endian.sign;
- }
+ return build_int_cst_wide (type, quol, quoh);
}
-#else /* Target not IEEE */
+\f
+/* This is nonzero if we should defer warnings about undefined
+ overflow. This facility exists because these warnings are a
+ special case. The code to estimate loop iterations does not want
+ to issue any warnings, since it works with expressions which do not
+ occur in user code. Various bits of cleanup code call fold(), but
+ only use the result if it has certain characteristics (e.g., is a
+ constant); that code only wants to issue a warning if the result is
+ used. */
-/* Let's assume other float formats don't have infinity.
- (This can be overridden by redefining REAL_VALUE_ISINF.) */
+static int fold_deferring_overflow_warnings;
-int
-target_isinf (x)
- REAL_VALUE_TYPE x ATTRIBUTE_UNUSED;
-{
- return 0;
-}
+/* If a warning about undefined overflow is deferred, this is the
+ warning. Note that this may cause us to turn two warnings into
+ one, but that is fine since it is sufficient to only give one
+ warning per expression. */
-/* Let's assume other float formats don't have NaNs.
- (This can be overridden by redefining REAL_VALUE_ISNAN.) */
+static const char* fold_deferred_overflow_warning;
-int
-target_isnan (x)
- REAL_VALUE_TYPE x ATTRIBUTE_UNUSED;
-{
- return 0;
-}
+/* If a warning about undefined overflow is deferred, this is the
+ level at which the warning should be emitted. */
-/* Let's assume other float formats don't have minus zero.
- (This can be overridden by redefining REAL_VALUE_NEGATIVE.) */
+static enum warn_strict_overflow_code fold_deferred_overflow_code;
-int
-target_negative (x)
- REAL_VALUE_TYPE x;
+/* Start deferring overflow warnings. We could use a stack here to
+ permit nested calls, but at present it is not necessary. */
+
+void
+fold_defer_overflow_warnings (void)
{
- return x < 0;
+ ++fold_deferring_overflow_warnings;
}
-#endif /* Target not IEEE */
-/* Try to change R into its exact multiplicative inverse in machine mode
- MODE. Return nonzero function value if successful. */
-struct exact_real_inverse_args
-{
- REAL_VALUE_TYPE *r;
- enum machine_mode mode;
- int success;
-};
+/* Stop deferring overflow warnings. If there is a pending warning,
+ and ISSUE is true, then issue the warning if appropriate. STMT is
+ the statement with which the warning should be associated (used for
+ location information); STMT may be NULL. CODE is the level of the
+ warning--a warn_strict_overflow_code value. This function will use
+ the smaller of CODE and the deferred code when deciding whether to
+ issue the warning. CODE may be zero to mean to always use the
+ deferred code. */
-static void
-exact_real_inverse_1 (p)
- PTR p;
+void
+fold_undefer_overflow_warnings (bool issue, const_gimple stmt, int code)
{
- struct exact_real_inverse_args *args =
- (struct exact_real_inverse_args *) p;
-
- enum machine_mode mode = args->mode;
- REAL_VALUE_TYPE *r = args->r;
-
- union
- {
- double d;
- unsigned short i[4];
- }
- x, t, y;
-#ifdef CHECK_FLOAT_VALUE
- int i;
-#endif
+ const char *warnmsg;
+ location_t locus;
- /* Set array index to the less significant bits in the unions, depending
- on the endian-ness of the host doubles. */
-#if HOST_FLOAT_FORMAT == VAX_FLOAT_FORMAT \
- || HOST_FLOAT_FORMAT == IBM_FLOAT_FORMAT
-# define K 2
-#else
-# define K (2 * HOST_FLOAT_WORDS_BIG_ENDIAN)
-#endif
+ gcc_assert (fold_deferring_overflow_warnings > 0);
+ --fold_deferring_overflow_warnings;
+ if (fold_deferring_overflow_warnings > 0)
+ {
+ if (fold_deferred_overflow_warning != NULL
+ && code != 0
+ && code < (int) fold_deferred_overflow_code)
+ fold_deferred_overflow_code = code;
+ return;
+ }
- /* Domain check the argument. */
- x.d = *r;
- if (x.d == 0.0)
- goto fail;
+ warnmsg = fold_deferred_overflow_warning;
+ fold_deferred_overflow_warning = NULL;
-#ifdef REAL_INFINITY
- if (REAL_VALUE_ISINF (x.d) || REAL_VALUE_ISNAN (x.d))
- goto fail;
-#endif
+ if (!issue || warnmsg == NULL)
+ return;
- /* Compute the reciprocal and check for numerical exactness.
- It is unnecessary to check all the significand bits to determine
- whether X is a power of 2. If X is not, then it is impossible for
- the bottom half significand of both X and 1/X to be all zero bits.
- Hence we ignore the data structure of the top half and examine only
- the low order bits of the two significands. */
- t.d = 1.0 / x.d;
- if (x.i[K] != 0 || x.i[K + 1] != 0 || t.i[K] != 0 || t.i[K + 1] != 0)
- goto fail;
-
- /* Truncate to the required mode and range-check the result. */
- y.d = REAL_VALUE_TRUNCATE (mode, t.d);
-#ifdef CHECK_FLOAT_VALUE
- i = 0;
- if (CHECK_FLOAT_VALUE (mode, y.d, i))
- goto fail;
-#endif
+ if (gimple_no_warning_p (stmt))
+ return;
- /* Fail if truncation changed the value. */
- if (y.d != t.d || y.d == 0.0)
- goto fail;
+ /* Use the smallest code level when deciding to issue the
+ warning. */
+ if (code == 0 || code > (int) fold_deferred_overflow_code)
+ code = fold_deferred_overflow_code;
-#ifdef REAL_INFINITY
- if (REAL_VALUE_ISINF (y.d) || REAL_VALUE_ISNAN (y.d))
- goto fail;
-#endif
+ if (!issue_strict_overflow_warning (code))
+ return;
- /* Output the reciprocal and return success flag. */
- *r = y.d;
- args->success = 1;
- return;
+ if (stmt == NULL)
+ locus = input_location;
+ else
+ locus = gimple_location (stmt);
+ warning (OPT_Wstrict_overflow, "%H%s", &locus, warnmsg);
+}
- fail:
- args->success = 0;
- return;
+/* Stop deferring overflow warnings, ignoring any deferred
+ warnings. */
-#undef K
+void
+fold_undefer_and_ignore_overflow_warnings (void)
+{
+ fold_undefer_overflow_warnings (false, NULL, 0);
}
+/* Whether we are deferring overflow warnings. */
-int
-exact_real_inverse (mode, r)
- enum machine_mode mode;
- REAL_VALUE_TYPE *r;
+bool
+fold_deferring_overflow_warnings_p (void)
{
- struct exact_real_inverse_args args;
-
- /* Disable if insufficient information on the data structure. */
-#if HOST_FLOAT_FORMAT == UNKNOWN_FLOAT_FORMAT
- return 0;
-#endif
+ return fold_deferring_overflow_warnings > 0;
+}
- /* Usually disable if bounds checks are not reliable. */
- if ((HOST_FLOAT_FORMAT != TARGET_FLOAT_FORMAT) && !flag_pretend_float)
- return 0;
+/* This is called when we fold something based on the fact that signed
+ overflow is undefined. */
- args.mode = mode;
- args.r = r;
+static void
+fold_overflow_warning (const char* gmsgid, enum warn_strict_overflow_code wc)
+{
+ if (fold_deferring_overflow_warnings > 0)
+ {
+ if (fold_deferred_overflow_warning == NULL
+ || wc < fold_deferred_overflow_code)
+ {
+ fold_deferred_overflow_warning = gmsgid;
+ fold_deferred_overflow_code = wc;
+ }
+ }
+ else if (issue_strict_overflow_warning (wc))
+ warning (OPT_Wstrict_overflow, gmsgid);
+}
+\f
+/* Return true if the built-in mathematical function specified by CODE
+ is odd, i.e. -f(x) == f(-x). */
- if (do_float_handler (exact_real_inverse_1, (PTR) &args))
- return args.success;
- return 0;
+static bool
+negate_mathfn_p (enum built_in_function code)
+{
+ switch (code)
+ {
+ CASE_FLT_FN (BUILT_IN_ASIN):
+ CASE_FLT_FN (BUILT_IN_ASINH):
+ CASE_FLT_FN (BUILT_IN_ATAN):
+ CASE_FLT_FN (BUILT_IN_ATANH):
+ CASE_FLT_FN (BUILT_IN_CASIN):
+ CASE_FLT_FN (BUILT_IN_CASINH):
+ CASE_FLT_FN (BUILT_IN_CATAN):
+ CASE_FLT_FN (BUILT_IN_CATANH):
+ CASE_FLT_FN (BUILT_IN_CBRT):
+ CASE_FLT_FN (BUILT_IN_CPROJ):
+ CASE_FLT_FN (BUILT_IN_CSIN):
+ CASE_FLT_FN (BUILT_IN_CSINH):
+ CASE_FLT_FN (BUILT_IN_CTAN):
+ CASE_FLT_FN (BUILT_IN_CTANH):
+ CASE_FLT_FN (BUILT_IN_ERF):
+ CASE_FLT_FN (BUILT_IN_LLROUND):
+ CASE_FLT_FN (BUILT_IN_LROUND):
+ CASE_FLT_FN (BUILT_IN_ROUND):
+ CASE_FLT_FN (BUILT_IN_SIN):
+ CASE_FLT_FN (BUILT_IN_SINH):
+ CASE_FLT_FN (BUILT_IN_TAN):
+ CASE_FLT_FN (BUILT_IN_TANH):
+ CASE_FLT_FN (BUILT_IN_TRUNC):
+ return true;
+
+ CASE_FLT_FN (BUILT_IN_LLRINT):
+ CASE_FLT_FN (BUILT_IN_LRINT):
+ CASE_FLT_FN (BUILT_IN_NEARBYINT):
+ CASE_FLT_FN (BUILT_IN_RINT):
+ return !flag_rounding_math;
+
+ default:
+ break;
+ }
+ return false;
}
-/* Convert C99 hexadecimal floating point string constant S. Return
- real value type in mode MODE. This function uses the host computer's
- floating point arithmetic when there is no REAL_ARITHMETIC. */
+/* Check whether we may negate an integer constant T without causing
+ overflow. */
-REAL_VALUE_TYPE
-real_hex_to_f (s, mode)
- const char *s;
- enum machine_mode mode;
+bool
+may_negate_without_overflow_p (const_tree t)
{
- REAL_VALUE_TYPE ip;
- const char *p = s;
- unsigned HOST_WIDE_INT low, high;
- int shcount, nrmcount, k;
- int sign, expsign, isfloat;
- int lost = 0;/* Nonzero low order bits shifted out and discarded. */
- int frexpon = 0; /* Bits after the decimal point. */
- int expon = 0; /* Value of exponent. */
- int decpt = 0; /* How many decimal points. */
- int gotp = 0; /* How many P's. */
- char c;
-
- isfloat = 0;
- expsign = 1;
- ip = 0.0;
+ unsigned HOST_WIDE_INT val;
+ unsigned int prec;
+ tree type;
- while (*p == ' ' || *p == '\t')
- ++p;
+ gcc_assert (TREE_CODE (t) == INTEGER_CST);
- /* Sign, if any, comes first. */
- sign = 1;
- if (*p == '-')
- {
- sign = -1;
- ++p;
- }
+ type = TREE_TYPE (t);
+ if (TYPE_UNSIGNED (type))
+ return false;
- /* The string is supposed to start with 0x or 0X . */
- if (*p == '0')
+ prec = TYPE_PRECISION (type);
+ if (prec > HOST_BITS_PER_WIDE_INT)
{
- ++p;
- if (*p == 'x' || *p == 'X')
- ++p;
- else
- abort ();
+ if (TREE_INT_CST_LOW (t) != 0)
+ return true;
+ prec -= HOST_BITS_PER_WIDE_INT;
+ val = TREE_INT_CST_HIGH (t);
}
else
- abort ();
+ val = TREE_INT_CST_LOW (t);
+ if (prec < HOST_BITS_PER_WIDE_INT)
+ val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
+ return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
+}
- while (*p == '0')
- ++p;
+/* Determine whether an expression T can be cheaply negated using
+ the function negate_expr without introducing undefined overflow. */
- high = 0;
- low = 0;
- shcount = 0;
- while ((c = *p) != '\0')
- {
- if (ISXDIGIT (c))
- {
- k = hex_value (c & CHARMASK);
+static bool
+negate_expr_p (tree t)
+{
+ tree type;
- if ((high & 0xf0000000) == 0)
- {
- high = (high << 4) + ((low >> 28) & 15);
- low = (low << 4) + k;
- shcount += 4;
- if (decpt)
- frexpon += 4;
- }
- else
- {
- /* Record nonzero lost bits. */
- lost |= k;
- if (! decpt)
- frexpon -= 4;
- }
- ++p;
- }
- else if (c == '.')
- {
- ++decpt;
- ++p;
- }
+ if (t == 0)
+ return false;
- else if (c == 'p' || c == 'P')
- {
- ++gotp;
- ++p;
- /* Sign of exponent. */
- if (*p == '-')
- {
- expsign = -1;
- ++p;
- }
+ type = TREE_TYPE (t);
- /* Value of exponent.
- The exponent field is a decimal integer. */
- while (ISDIGIT (*p))
- {
- k = (*p++ & CHARMASK) - '0';
- expon = 10 * expon + k;
- }
+ STRIP_SIGN_NOPS (t);
+ switch (TREE_CODE (t))
+ {
+ case INTEGER_CST:
+ if (TYPE_OVERFLOW_WRAPS (type))
+ return true;
- expon *= expsign;
- /* F suffix is ambiguous in the significand part
- so it must appear after the decimal exponent field. */
- if (*p == 'f' || *p == 'F')
- {
- isfloat = 1;
- ++p;
- break;
- }
- }
+ /* Check that -CST will not overflow type. */
+ return may_negate_without_overflow_p (t);
+ case BIT_NOT_EXPR:
+ return (INTEGRAL_TYPE_P (type)
+ && TYPE_OVERFLOW_WRAPS (type));
- else if (c == 'l' || c == 'L')
- {
- ++p;
- break;
- }
- else
- break;
- }
+ case FIXED_CST:
+ case REAL_CST:
+ case NEGATE_EXPR:
+ return true;
- /* Abort if last character read was not legitimate. */
- c = *p;
- if ((c != '\0' && c != ' ' && c != '\n' && c != '\r') || (decpt > 1))
- abort ();
+ case COMPLEX_CST:
+ return negate_expr_p (TREE_REALPART (t))
+ && negate_expr_p (TREE_IMAGPART (t));
- /* There must be either one decimal point or one p. */
- if (decpt == 0 && gotp == 0)
- abort ();
+ case COMPLEX_EXPR:
+ return negate_expr_p (TREE_OPERAND (t, 0))
+ && negate_expr_p (TREE_OPERAND (t, 1));
- shcount -= 4;
- if (high == 0 && low == 0)
- return dconst0;
+ case CONJ_EXPR:
+ return negate_expr_p (TREE_OPERAND (t, 0));
- /* Normalize. */
- nrmcount = 0;
- if (high == 0)
- {
- high = low;
- low = 0;
- nrmcount += 32;
- }
+ case PLUS_EXPR:
+ if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
+ || HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
+ return false;
+ /* -(A + B) -> (-B) - A. */
+ if (negate_expr_p (TREE_OPERAND (t, 1))
+ && reorder_operands_p (TREE_OPERAND (t, 0),
+ TREE_OPERAND (t, 1)))
+ return true;
+ /* -(A + B) -> (-A) - B. */
+ return negate_expr_p (TREE_OPERAND (t, 0));
- /* Leave a high guard bit for carry-out. */
- if ((high & 0x80000000) != 0)
- {
- lost |= low & 1;
- low = (low >> 1) | (high << 31);
- high = high >> 1;
- nrmcount -= 1;
- }
+ case MINUS_EXPR:
+ /* We can't turn -(A-B) into B-A when we honor signed zeros. */
+ return !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
+ && !HONOR_SIGNED_ZEROS (TYPE_MODE (type))
+ && reorder_operands_p (TREE_OPERAND (t, 0),
+ TREE_OPERAND (t, 1));
- if ((high & 0xffff8000) == 0)
- {
- high = (high << 16) + ((low >> 16) & 0xffff);
- low = low << 16;
- nrmcount += 16;
- }
+ case MULT_EXPR:
+ if (TYPE_UNSIGNED (TREE_TYPE (t)))
+ break;
- while ((high & 0xc0000000) == 0)
- {
- high = (high << 1) + ((low >> 31) & 1);
- low = low << 1;
- nrmcount += 1;
- }
+ /* Fall through. */
- if (isfloat || GET_MODE_SIZE (mode) == UNITS_PER_WORD)
- {
- /* Keep 24 bits precision, bits 0x7fffff80.
- Rounding bit is 0x40. */
- lost = lost | low | (high & 0x3f);
- low = 0;
- if (high & 0x40)
- {
- if ((high & 0x80) || lost)
- high += 0x40;
- }
- high &= 0xffffff80;
- }
- else
- {
- /* We need real.c to do long double formats, so here default
- to double precision. */
-#if HOST_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
- /* IEEE double.
- Keep 53 bits precision, bits 0x7fffffff fffffc00.
- Rounding bit is low word 0x200. */
- lost = lost | (low & 0x1ff);
- if (low & 0x200)
+ case RDIV_EXPR:
+ if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
+ return negate_expr_p (TREE_OPERAND (t, 1))
+ || negate_expr_p (TREE_OPERAND (t, 0));
+ break;
+
+ case TRUNC_DIV_EXPR:
+ case ROUND_DIV_EXPR:
+ case FLOOR_DIV_EXPR:
+ case CEIL_DIV_EXPR:
+ case EXACT_DIV_EXPR:
+ /* In general we can't negate A / B, because if A is INT_MIN and
+ B is 1, we may turn this into INT_MIN / -1 which is undefined
+ and actually traps on some architectures. But if overflow is
+ undefined, we can negate, because - (INT_MIN / 1) is an
+ overflow. */
+ if (INTEGRAL_TYPE_P (TREE_TYPE (t))
+ && !TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (t)))
+ break;
+ return negate_expr_p (TREE_OPERAND (t, 1))
+ || negate_expr_p (TREE_OPERAND (t, 0));
+
+ case NOP_EXPR:
+ /* Negate -((double)float) as (double)(-float). */
+ if (TREE_CODE (type) == REAL_TYPE)
{
- if ((low & 0x400) || lost)
- {
- low = (low + 0x200) & 0xfffffc00;
- if (low == 0)
- high += 1;
- }
+ tree tem = strip_float_extensions (t);
+ if (tem != t)
+ return negate_expr_p (tem);
}
- low &= 0xfffffc00;
-#else
- /* Assume it's a VAX with 56-bit significand,
- bits 0x7fffffff ffffff80. */
- lost = lost | (low & 0x7f);
- if (low & 0x40)
+ break;
+
+ case CALL_EXPR:
+ /* Negate -f(x) as f(-x). */
+ if (negate_mathfn_p (builtin_mathfn_code (t)))
+ return negate_expr_p (CALL_EXPR_ARG (t, 0));
+ break;
+
+ case RSHIFT_EXPR:
+ /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
+ if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
{
- if ((low & 0x80) || lost)
- {
- low = (low + 0x40) & 0xffffff80;
- if (low == 0)
- high += 1;
- }
+ tree op1 = TREE_OPERAND (t, 1);
+ if (TREE_INT_CST_HIGH (op1) == 0
+ && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
+ == TREE_INT_CST_LOW (op1))
+ return true;
}
- low &= 0xffffff80;
-#endif
- }
-
- ip = (double) high;
- ip = REAL_VALUE_LDEXP (ip, 32) + (double) low;
- /* Apply shifts and exponent value as power of 2. */
- ip = REAL_VALUE_LDEXP (ip, expon - (nrmcount + frexpon));
+ break;
- if (sign < 0)
- ip = -ip;
- return ip;
+ default:
+ break;
+ }
+ return false;
}
-#endif /* no REAL_ARITHMETIC */
-\f
-/* Given T, an expression, return the negation of T. Allow for T to be
- null, in which case return null. */
+/* Given T, an expression, return a folded tree for -T or NULL_TREE, if no
+ simplification is possible.
+ If negate_expr_p would return true for T, NULL_TREE will never be
+ returned. */
static tree
-negate_expr (t)
- tree t;
+fold_negate_expr (tree t)
{
- tree type;
+ tree type = TREE_TYPE (t);
tree tem;
- if (t == 0)
- return 0;
-
- type = TREE_TYPE (t);
- STRIP_SIGN_NOPS (t);
-
switch (TREE_CODE (t))
{
+ /* Convert - (~A) to A + 1. */
+ case BIT_NOT_EXPR:
+ if (INTEGRAL_TYPE_P (type))
+ return fold_build2 (PLUS_EXPR, type, TREE_OPERAND (t, 0),
+ build_int_cst (type, 1));
+ break;
+
case INTEGER_CST:
+ tem = fold_negate_const (t, type);
+ if (TREE_OVERFLOW (tem) == TREE_OVERFLOW (t)
+ || !TYPE_OVERFLOW_TRAPS (type))
+ return tem;
+ break;
+
case REAL_CST:
- if (! TREE_UNSIGNED (type)
- && 0 != (tem = fold (build1 (NEGATE_EXPR, type, t)))
- && ! TREE_OVERFLOW (tem))
+ tem = fold_negate_const (t, type);
+ /* Two's complement FP formats, such as c4x, may overflow. */
+ if (!TREE_OVERFLOW (tem) || !flag_trapping_math)
return tem;
break;
- case NEGATE_EXPR:
- return convert (type, TREE_OPERAND (t, 0));
+ case FIXED_CST:
+ tem = fold_negate_const (t, type);
+ return tem;
- case MINUS_EXPR:
- /* - (A - B) -> B - A */
- if (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
- return convert (type,
- fold (build (MINUS_EXPR, TREE_TYPE (t),
- TREE_OPERAND (t, 1),
- TREE_OPERAND (t, 0))));
+ case COMPLEX_CST:
+ {
+ tree rpart = negate_expr (TREE_REALPART (t));
+ tree ipart = negate_expr (TREE_IMAGPART (t));
+
+ if ((TREE_CODE (rpart) == REAL_CST
+ && TREE_CODE (ipart) == REAL_CST)
+ || (TREE_CODE (rpart) == INTEGER_CST
+ && TREE_CODE (ipart) == INTEGER_CST))
+ return build_complex (type, rpart, ipart);
+ }
+ break;
+
+ case COMPLEX_EXPR:
+ if (negate_expr_p (t))
+ return fold_build2 (COMPLEX_EXPR, type,
+ fold_negate_expr (TREE_OPERAND (t, 0)),
+ fold_negate_expr (TREE_OPERAND (t, 1)));
+ break;
+
+ case CONJ_EXPR:
+ if (negate_expr_p (t))
+ return fold_build1 (CONJ_EXPR, type,
+ fold_negate_expr (TREE_OPERAND (t, 0)));
+ break;
+
+ case NEGATE_EXPR:
+ return TREE_OPERAND (t, 0);
+
+ case PLUS_EXPR:
+ if (!HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
+ && !HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
+ {
+ /* -(A + B) -> (-B) - A. */
+ if (negate_expr_p (TREE_OPERAND (t, 1))
+ && reorder_operands_p (TREE_OPERAND (t, 0),
+ TREE_OPERAND (t, 1)))
+ {
+ tem = negate_expr (TREE_OPERAND (t, 1));
+ return fold_build2 (MINUS_EXPR, type,
+ tem, TREE_OPERAND (t, 0));
+ }
+
+ /* -(A + B) -> (-A) - B. */
+ if (negate_expr_p (TREE_OPERAND (t, 0)))
+ {
+ tem = negate_expr (TREE_OPERAND (t, 0));
+ return fold_build2 (MINUS_EXPR, type,
+ tem, TREE_OPERAND (t, 1));
+ }
+ }
+ break;
+
+ case MINUS_EXPR:
+ /* - (A - B) -> B - A */
+ if (!HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
+ && !HONOR_SIGNED_ZEROS (TYPE_MODE (type))
+ && reorder_operands_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1)))
+ return fold_build2 (MINUS_EXPR, type,
+ TREE_OPERAND (t, 1), TREE_OPERAND (t, 0));
+ break;
+
+ case MULT_EXPR:
+ if (TYPE_UNSIGNED (type))
+ break;
+
+ /* Fall through. */
+
+ case RDIV_EXPR:
+ if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type)))
+ {
+ tem = TREE_OPERAND (t, 1);
+ if (negate_expr_p (tem))
+ return fold_build2 (TREE_CODE (t), type,
+ TREE_OPERAND (t, 0), negate_expr (tem));
+ tem = TREE_OPERAND (t, 0);
+ if (negate_expr_p (tem))
+ return fold_build2 (TREE_CODE (t), type,
+ negate_expr (tem), TREE_OPERAND (t, 1));
+ }
+ break;
+
+ case TRUNC_DIV_EXPR:
+ case ROUND_DIV_EXPR:
+ case FLOOR_DIV_EXPR:
+ case CEIL_DIV_EXPR:
+ case EXACT_DIV_EXPR:
+ /* In general we can't negate A / B, because if A is INT_MIN and
+ B is 1, we may turn this into INT_MIN / -1 which is undefined
+ and actually traps on some architectures. But if overflow is
+ undefined, we can negate, because - (INT_MIN / 1) is an
+ overflow. */
+ if (!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
+ {
+ const char * const warnmsg = G_("assuming signed overflow does not "
+ "occur when negating a division");
+ tem = TREE_OPERAND (t, 1);
+ if (negate_expr_p (tem))
+ {
+ if (INTEGRAL_TYPE_P (type)
+ && (TREE_CODE (tem) != INTEGER_CST
+ || integer_onep (tem)))
+ fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MISC);
+ return fold_build2 (TREE_CODE (t), type,
+ TREE_OPERAND (t, 0), negate_expr (tem));
+ }
+ tem = TREE_OPERAND (t, 0);
+ if (negate_expr_p (tem))
+ {
+ if (INTEGRAL_TYPE_P (type)
+ && (TREE_CODE (tem) != INTEGER_CST
+ || tree_int_cst_equal (tem, TYPE_MIN_VALUE (type))))
+ fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MISC);
+ return fold_build2 (TREE_CODE (t), type,
+ negate_expr (tem), TREE_OPERAND (t, 1));
+ }
+ }
+ break;
+
+ case NOP_EXPR:
+ /* Convert -((double)float) into (double)(-float). */
+ if (TREE_CODE (type) == REAL_TYPE)
+ {
+ tem = strip_float_extensions (t);
+ if (tem != t && negate_expr_p (tem))
+ return fold_convert (type, negate_expr (tem));
+ }
+ break;
+
+ case CALL_EXPR:
+ /* Negate -f(x) as f(-x). */
+ if (negate_mathfn_p (builtin_mathfn_code (t))
+ && negate_expr_p (CALL_EXPR_ARG (t, 0)))
+ {
+ tree fndecl, arg;
+
+ fndecl = get_callee_fndecl (t);
+ arg = negate_expr (CALL_EXPR_ARG (t, 0));
+ return build_call_expr (fndecl, 1, arg);
+ }
+ break;
+
+ case RSHIFT_EXPR:
+ /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
+ if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
+ {
+ tree op1 = TREE_OPERAND (t, 1);
+ if (TREE_INT_CST_HIGH (op1) == 0
+ && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
+ == TREE_INT_CST_LOW (op1))
+ {
+ tree ntype = TYPE_UNSIGNED (type)
+ ? signed_type_for (type)
+ : unsigned_type_for (type);
+ tree temp = fold_convert (ntype, TREE_OPERAND (t, 0));
+ temp = fold_build2 (RSHIFT_EXPR, ntype, temp, op1);
+ return fold_convert (type, temp);
+ }
+ }
break;
default:
break;
}
- return convert (type, fold (build1 (NEGATE_EXPR, TREE_TYPE (t), t)));
+ return NULL_TREE;
+}
+
+/* Like fold_negate_expr, but return a NEGATE_EXPR tree, if T can not be
+ negated in a simpler way. Also allow for T to be NULL_TREE, in which case
+ return NULL_TREE. */
+
+static tree
+negate_expr (tree t)
+{
+ tree type, tem;
+
+ if (t == NULL_TREE)
+ return NULL_TREE;
+
+ type = TREE_TYPE (t);
+ STRIP_SIGN_NOPS (t);
+
+ tem = fold_negate_expr (t);
+ if (!tem)
+ tem = build1 (NEGATE_EXPR, TREE_TYPE (t), t);
+ return fold_convert (type, tem);
}
\f
/* Split a tree IN into a constant, literal and variable parts that could be
same type as IN, but they will have the same signedness and mode. */
static tree
-split_tree (in, code, conp, litp, minus_litp, negate_p)
- tree in;
- enum tree_code code;
- tree *conp, *litp, *minus_litp;
- int negate_p;
+split_tree (tree in, enum tree_code code, tree *conp, tree *litp,
+ tree *minus_litp, int negate_p)
{
tree var = 0;
/* Strip any conversions that don't change the machine mode or signedness. */
STRIP_SIGN_NOPS (in);
- if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
+ if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST
+ || TREE_CODE (in) == FIXED_CST)
*litp = in;
else if (TREE_CODE (in) == code
- || (! FLOAT_TYPE_P (TREE_TYPE (in))
+ || ((! FLOAT_TYPE_P (TREE_TYPE (in)) || flag_associative_math)
+ && ! SAT_FIXED_POINT_TYPE_P (TREE_TYPE (in))
/* We can associate addition and subtraction together (even
though the C standard doesn't say so) for integers because
the value is not affected. For reals, the value might be
int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
/* First see if either of the operands is a literal, then a constant. */
- if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
+ if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST
+ || TREE_CODE (op0) == FIXED_CST)
*litp = op0, op0 = 0;
- else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
+ else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST
+ || TREE_CODE (op1) == FIXED_CST)
*litp = op1, neg_litp_p = neg1_p, op1 = 0;
if (op0 != 0 && TREE_CONSTANT (op0))
we build an operation, do it in TYPE and with CODE. */
static tree
-associate_trees (t1, t2, code, type)
- tree t1, t2;
- enum tree_code code;
- tree type;
+associate_trees (tree t1, tree t2, enum tree_code code, tree type)
{
if (t1 == 0)
return t2;
if (code == PLUS_EXPR)
{
if (TREE_CODE (t1) == NEGATE_EXPR)
- return build (MINUS_EXPR, type, convert (type, t2),
- convert (type, TREE_OPERAND (t1, 0)));
+ return build2 (MINUS_EXPR, type, fold_convert (type, t2),
+ fold_convert (type, TREE_OPERAND (t1, 0)));
else if (TREE_CODE (t2) == NEGATE_EXPR)
- return build (MINUS_EXPR, type, convert (type, t1),
- convert (type, TREE_OPERAND (t2, 0)));
+ return build2 (MINUS_EXPR, type, fold_convert (type, t1),
+ fold_convert (type, TREE_OPERAND (t2, 0)));
+ else if (integer_zerop (t2))
+ return fold_convert (type, t1);
+ }
+ else if (code == MINUS_EXPR)
+ {
+ if (integer_zerop (t2))
+ return fold_convert (type, t1);
}
- return build (code, type, convert (type, t1), convert (type, t2));
+
+ return build2 (code, type, fold_convert (type, t1),
+ fold_convert (type, t2));
}
- return fold (build (code, type, convert (type, t1), convert (type, t2)));
+ return fold_build2 (code, type, fold_convert (type, t1),
+ fold_convert (type, t2));
}
\f
+/* Check whether TYPE1 and TYPE2 are equivalent integer types, suitable
+ for use in int_const_binop, size_binop and size_diffop. */
+
+static bool
+int_binop_types_match_p (enum tree_code code, const_tree type1, const_tree type2)
+{
+ if (TREE_CODE (type1) != INTEGER_TYPE && !POINTER_TYPE_P (type1))
+ return false;
+ if (TREE_CODE (type2) != INTEGER_TYPE && !POINTER_TYPE_P (type2))
+ return false;
+
+ switch (code)
+ {
+ case LSHIFT_EXPR:
+ case RSHIFT_EXPR:
+ case LROTATE_EXPR:
+ case RROTATE_EXPR:
+ return true;
+
+ default:
+ break;
+ }
+
+ return TYPE_UNSIGNED (type1) == TYPE_UNSIGNED (type2)
+ && TYPE_PRECISION (type1) == TYPE_PRECISION (type2)
+ && TYPE_MODE (type1) == TYPE_MODE (type2);
+}
+
+
/* Combine two integer constants ARG1 and ARG2 under operation CODE
- to produce a new constant.
+ to produce a new constant. Return NULL_TREE if we don't know how
+ to evaluate CODE at compile-time.
If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
-static tree
-int_const_binop (code, arg1, arg2, notrunc)
- enum tree_code code;
- tree arg1, arg2;
- int notrunc;
+tree
+int_const_binop (enum tree_code code, const_tree arg1, const_tree arg2, int notrunc)
{
unsigned HOST_WIDE_INT int1l, int2l;
HOST_WIDE_INT int1h, int2h;
HOST_WIDE_INT garbageh;
tree t;
tree type = TREE_TYPE (arg1);
- int uns = TREE_UNSIGNED (type);
+ int uns = TYPE_UNSIGNED (type);
int is_sizetype
= (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
int overflow = 0;
- int no_overflow = 0;
int1l = TREE_INT_CST_LOW (arg1);
int1h = TREE_INT_CST_HIGH (arg1);
low = int1l & int2l, hi = int1h & int2h;
break;
- case BIT_ANDTC_EXPR:
- low = int1l & ~int2l, hi = int1h & ~int2h;
- break;
-
case RSHIFT_EXPR:
int2l = -int2l;
case LSHIFT_EXPR:
interpretation ruling is needed. */
lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
&low, &hi, !uns);
- no_overflow = 1;
break;
case RROTATE_EXPR:
case EXACT_DIV_EXPR:
/* This is a shortcut for a common special case. */
if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
- && ! TREE_CONSTANT_OVERFLOW (arg1)
- && ! TREE_CONSTANT_OVERFLOW (arg2)
+ && !TREE_OVERFLOW (arg1)
+ && !TREE_OVERFLOW (arg2)
&& int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
{
if (code == CEIL_DIV_EXPR)
/* ... fall through ... */
case ROUND_DIV_EXPR:
+ if (int2h == 0 && int2l == 0)
+ return NULL_TREE;
if (int2h == 0 && int2l == 1)
{
low = int1l, hi = int1h;
case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
/* This is a shortcut for a common special case. */
if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
- && ! TREE_CONSTANT_OVERFLOW (arg1)
- && ! TREE_CONSTANT_OVERFLOW (arg2)
+ && !TREE_OVERFLOW (arg1)
+ && !TREE_OVERFLOW (arg2)
&& int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
{
if (code == CEIL_MOD_EXPR)
/* ... fall through ... */
case ROUND_MOD_EXPR:
+ if (int2h == 0 && int2l == 0)
+ return NULL_TREE;
overflow = div_and_round_double (code, uns,
int1l, int1h, int2l, int2h,
&garbagel, &garbageh, &low, &hi);
break;
default:
- abort ();
+ return NULL_TREE;
}
- /* If this is for a sizetype, can be represented as one (signed)
- HOST_WIDE_INT word, and doesn't overflow, use size_int since it caches
- constants. */
- if (is_sizetype
- && ((hi == 0 && (HOST_WIDE_INT) low >= 0)
- || (hi == -1 && (HOST_WIDE_INT) low < 0))
- && overflow == 0 && ! TREE_OVERFLOW (arg1) && ! TREE_OVERFLOW (arg2))
- return size_int_type_wide (low, type);
- else
- {
- t = build_int_2 (low, hi);
- TREE_TYPE (t) = TREE_TYPE (arg1);
- }
-
- TREE_OVERFLOW (t)
- = ((notrunc
- ? (!uns || is_sizetype) && overflow
- : (force_fit_type (t, (!uns || is_sizetype) && overflow)
- && ! no_overflow))
- | TREE_OVERFLOW (arg1)
- | TREE_OVERFLOW (arg2));
-
- /* If we're doing a size calculation, unsigned arithmetic does overflow.
- So check if force_fit_type truncated the value. */
- if (is_sizetype
- && ! TREE_OVERFLOW (t)
- && (TREE_INT_CST_HIGH (t) != hi
- || TREE_INT_CST_LOW (t) != low))
- TREE_OVERFLOW (t) = 1;
-
- TREE_CONSTANT_OVERFLOW (t) = (TREE_OVERFLOW (t)
- | TREE_CONSTANT_OVERFLOW (arg1)
- | TREE_CONSTANT_OVERFLOW (arg2));
- return t;
-}
-
-/* Define input and output argument for const_binop_1. */
-struct cb_args
-{
- enum tree_code code; /* Input: tree code for operation. */
- tree type; /* Input: tree type for operation. */
- REAL_VALUE_TYPE d1, d2; /* Input: floating point operands. */
- tree t; /* Output: constant for result. */
-};
-
-/* Do the real arithmetic for const_binop while protected by a
- float overflow handler. */
-
-static void
-const_binop_1 (data)
- PTR data;
-{
- struct cb_args *args = (struct cb_args *) data;
- REAL_VALUE_TYPE value;
-
-#ifdef REAL_ARITHMETIC
- REAL_ARITHMETIC (value, args->code, args->d1, args->d2);
-#else
- switch (args->code)
+ if (notrunc)
{
- case PLUS_EXPR:
- value = args->d1 + args->d2;
- break;
-
- case MINUS_EXPR:
- value = args->d1 - args->d2;
- break;
-
- case MULT_EXPR:
- value = args->d1 * args->d2;
- break;
-
- case RDIV_EXPR:
-#ifndef REAL_INFINITY
- if (args->d2 == 0)
- abort ();
-#endif
-
- value = args->d1 / args->d2;
- break;
-
- case MIN_EXPR:
- value = MIN (args->d1, args->d2);
- break;
-
- case MAX_EXPR:
- value = MAX (args->d1, args->d2);
- break;
+ t = build_int_cst_wide (TREE_TYPE (arg1), low, hi);
- default:
- abort ();
+ /* Propagate overflow flags ourselves. */
+ if (((!uns || is_sizetype) && overflow)
+ | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2))
+ {
+ t = copy_node (t);
+ TREE_OVERFLOW (t) = 1;
+ }
}
-#endif /* no REAL_ARITHMETIC */
+ else
+ t = force_fit_type_double (TREE_TYPE (arg1), low, hi, 1,
+ ((!uns || is_sizetype) && overflow)
+ | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
- args->t
- = build_real (args->type,
- real_value_truncate (TYPE_MODE (args->type), value));
+ return t;
}
/* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
constant. We assume ARG1 and ARG2 have the same data type, or at least
- are the same kind of constant and the same machine mode.
+ are the same kind of constant and the same machine mode. Return zero if
+ combining the constants is not allowed in the current operating mode.
If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
static tree
-const_binop (code, arg1, arg2, notrunc)
- enum tree_code code;
- tree arg1, arg2;
- int notrunc;
+const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
{
+ /* Sanity check for the recursive cases. */
+ if (!arg1 || !arg2)
+ return NULL_TREE;
+
STRIP_NOPS (arg1);
STRIP_NOPS (arg2);
if (TREE_CODE (arg1) == INTEGER_CST)
return int_const_binop (code, arg1, arg2, notrunc);
-#if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
if (TREE_CODE (arg1) == REAL_CST)
{
+ enum machine_mode mode;
REAL_VALUE_TYPE d1;
REAL_VALUE_TYPE d2;
- int overflow = 0;
- tree t;
- struct cb_args args;
+ REAL_VALUE_TYPE value;
+ REAL_VALUE_TYPE result;
+ bool inexact;
+ tree t, type;
+
+ /* The following codes are handled by real_arithmetic. */
+ switch (code)
+ {
+ case PLUS_EXPR:
+ case MINUS_EXPR:
+ case MULT_EXPR:
+ case RDIV_EXPR:
+ case MIN_EXPR:
+ case MAX_EXPR:
+ break;
+
+ default:
+ return NULL_TREE;
+ }
d1 = TREE_REAL_CST (arg1);
d2 = TREE_REAL_CST (arg2);
+ type = TREE_TYPE (arg1);
+ mode = TYPE_MODE (type);
+
+ /* Don't perform operation if we honor signaling NaNs and
+ either operand is a NaN. */
+ if (HONOR_SNANS (mode)
+ && (REAL_VALUE_ISNAN (d1) || REAL_VALUE_ISNAN (d2)))
+ return NULL_TREE;
+
+ /* Don't perform operation if it would raise a division
+ by zero exception. */
+ if (code == RDIV_EXPR
+ && REAL_VALUES_EQUAL (d2, dconst0)
+ && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
+ return NULL_TREE;
+
/* If either operand is a NaN, just return it. Otherwise, set up
for floating-point trap; we return an overflow. */
if (REAL_VALUE_ISNAN (d1))
else if (REAL_VALUE_ISNAN (d2))
return arg2;
- /* Setup input for const_binop_1() */
- args.type = TREE_TYPE (arg1);
- args.d1 = d1;
- args.d2 = d2;
- args.code = code;
+ inexact = real_arithmetic (&value, code, &d1, &d2);
+ real_convert (&result, mode, &value);
+
+ /* Don't constant fold this floating point operation if
+ the result has overflowed and flag_trapping_math. */
+ if (flag_trapping_math
+ && MODE_HAS_INFINITIES (mode)
+ && REAL_VALUE_ISINF (result)
+ && !REAL_VALUE_ISINF (d1)
+ && !REAL_VALUE_ISINF (d2))
+ return NULL_TREE;
+
+ /* Don't constant fold this floating point operation if the
+ result may dependent upon the run-time rounding mode and
+ flag_rounding_math is set, or if GCC's software emulation
+ is unable to accurately represent the result. */
+ if ((flag_rounding_math
+ || (MODE_COMPOSITE_P (mode) && !flag_unsafe_math_optimizations))
+ && (inexact || !real_identical (&result, &value)))
+ return NULL_TREE;
+
+ t = build_real (type, result);
+
+ TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2);
+ return t;
+ }
- if (do_float_handler (const_binop_1, (PTR) &args))
- /* Receive output from const_binop_1. */
- t = args.t;
- else
+ if (TREE_CODE (arg1) == FIXED_CST)
+ {
+ FIXED_VALUE_TYPE f1;
+ FIXED_VALUE_TYPE f2;
+ FIXED_VALUE_TYPE result;
+ tree t, type;
+ int sat_p;
+ bool overflow_p;
+
+ /* The following codes are handled by fixed_arithmetic. */
+ switch (code)
+ {
+ case PLUS_EXPR:
+ case MINUS_EXPR:
+ case MULT_EXPR:
+ case TRUNC_DIV_EXPR:
+ f2 = TREE_FIXED_CST (arg2);
+ break;
+
+ case LSHIFT_EXPR:
+ case RSHIFT_EXPR:
+ f2.data.high = TREE_INT_CST_HIGH (arg2);
+ f2.data.low = TREE_INT_CST_LOW (arg2);
+ f2.mode = SImode;
+ break;
+
+ default:
+ return NULL_TREE;
+ }
+
+ f1 = TREE_FIXED_CST (arg1);
+ type = TREE_TYPE (arg1);
+ sat_p = TYPE_SATURATING (type);
+ overflow_p = fixed_arithmetic (&result, code, &f1, &f2, sat_p);
+ t = build_fixed (type, result);
+ /* Propagate overflow flags. */
+ if (overflow_p | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2))
{
- /* We got an exception from const_binop_1. */
- t = copy_node (arg1);
- overflow = 1;
+ TREE_OVERFLOW (t) = 1;
+ TREE_CONSTANT_OVERFLOW (t) = 1;
}
-
- TREE_OVERFLOW (t)
- = (force_fit_type (t, overflow)
- | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
- TREE_CONSTANT_OVERFLOW (t)
- = TREE_OVERFLOW (t)
- | TREE_CONSTANT_OVERFLOW (arg1)
- | TREE_CONSTANT_OVERFLOW (arg2);
+ else if (TREE_CONSTANT_OVERFLOW (arg1) | TREE_CONSTANT_OVERFLOW (arg2))
+ TREE_CONSTANT_OVERFLOW (t) = 1;
return t;
}
-#endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
+
if (TREE_CODE (arg1) == COMPLEX_CST)
{
tree type = TREE_TYPE (arg1);
tree i1 = TREE_IMAGPART (arg1);
tree r2 = TREE_REALPART (arg2);
tree i2 = TREE_IMAGPART (arg2);
- tree t;
+ tree real, imag;
switch (code)
{
case PLUS_EXPR:
- t = build_complex (type,
- const_binop (PLUS_EXPR, r1, r2, notrunc),
- const_binop (PLUS_EXPR, i1, i2, notrunc));
- break;
-
case MINUS_EXPR:
- t = build_complex (type,
- const_binop (MINUS_EXPR, r1, r2, notrunc),
- const_binop (MINUS_EXPR, i1, i2, notrunc));
+ real = const_binop (code, r1, r2, notrunc);
+ imag = const_binop (code, i1, i2, notrunc);
break;
case MULT_EXPR:
- t = build_complex (type,
- const_binop (MINUS_EXPR,
- const_binop (MULT_EXPR,
- r1, r2, notrunc),
- const_binop (MULT_EXPR,
- i1, i2, notrunc),
- notrunc),
- const_binop (PLUS_EXPR,
- const_binop (MULT_EXPR,
- r1, i2, notrunc),
- const_binop (MULT_EXPR,
- i1, r2, notrunc),
- notrunc));
+ real = const_binop (MINUS_EXPR,
+ const_binop (MULT_EXPR, r1, r2, notrunc),
+ const_binop (MULT_EXPR, i1, i2, notrunc),
+ notrunc);
+ imag = const_binop (PLUS_EXPR,
+ const_binop (MULT_EXPR, r1, i2, notrunc),
+ const_binop (MULT_EXPR, i1, r2, notrunc),
+ notrunc);
break;
case RDIV_EXPR:
const_binop (MULT_EXPR, r2, r2, notrunc),
const_binop (MULT_EXPR, i2, i2, notrunc),
notrunc);
+ tree t1
+ = const_binop (PLUS_EXPR,
+ const_binop (MULT_EXPR, r1, r2, notrunc),
+ const_binop (MULT_EXPR, i1, i2, notrunc),
+ notrunc);
+ tree t2
+ = const_binop (MINUS_EXPR,
+ const_binop (MULT_EXPR, i1, r2, notrunc),
+ const_binop (MULT_EXPR, r1, i2, notrunc),
+ notrunc);
- t = build_complex (type,
- const_binop
- (INTEGRAL_TYPE_P (TREE_TYPE (r1))
- ? TRUNC_DIV_EXPR : RDIV_EXPR,
- const_binop (PLUS_EXPR,
- const_binop (MULT_EXPR, r1, r2,
- notrunc),
- const_binop (MULT_EXPR, i1, i2,
- notrunc),
- notrunc),
- magsquared, notrunc),
- const_binop
- (INTEGRAL_TYPE_P (TREE_TYPE (r1))
- ? TRUNC_DIV_EXPR : RDIV_EXPR,
- const_binop (MINUS_EXPR,
- const_binop (MULT_EXPR, i1, r2,
- notrunc),
- const_binop (MULT_EXPR, r1, i2,
- notrunc),
- notrunc),
- magsquared, notrunc));
+ if (INTEGRAL_TYPE_P (TREE_TYPE (r1)))
+ code = TRUNC_DIV_EXPR;
+
+ real = const_binop (code, t1, magsquared, notrunc);
+ imag = const_binop (code, t2, magsquared, notrunc);
}
break;
default:
- abort ();
+ return NULL_TREE;
}
- return t;
- }
- return 0;
-}
-
-/* These are the hash table functions for the hash table of INTEGER_CST
- nodes of a sizetype. */
-
-/* Return the hash code code X, an INTEGER_CST. */
-
-static hashval_t
-size_htab_hash (x)
- const void *x;
-{
- tree t = (tree) x;
-
- return (TREE_INT_CST_HIGH (t) ^ TREE_INT_CST_LOW (t)
- ^ (hashval_t) ((long) TREE_TYPE (t) >> 3)
- ^ (TREE_OVERFLOW (t) << 20));
-}
-
-/* Return non-zero if the value represented by *X (an INTEGER_CST tree node)
- is the same as that given by *Y, which is the same. */
-static int
-size_htab_eq (x, y)
- const void *x;
- const void *y;
-{
- tree xt = (tree) x;
- tree yt = (tree) y;
-
- return (TREE_INT_CST_HIGH (xt) == TREE_INT_CST_HIGH (yt)
- && TREE_INT_CST_LOW (xt) == TREE_INT_CST_LOW (yt)
- && TREE_TYPE (xt) == TREE_TYPE (yt)
- && TREE_OVERFLOW (xt) == TREE_OVERFLOW (yt));
-}
-\f
-/* Return an INTEGER_CST with value whose low-order HOST_BITS_PER_WIDE_INT
- bits are given by NUMBER and of the sizetype represented by KIND. */
+ if (real && imag)
+ return build_complex (type, real, imag);
+ }
-tree
-size_int_wide (number, kind)
- HOST_WIDE_INT number;
- enum size_type_kind kind;
-{
- return size_int_type_wide (number, sizetype_tab[(int) kind]);
+ return NULL_TREE;
}
-/* Likewise, but the desired type is specified explicitly. */
+/* Create a size type INT_CST node with NUMBER sign extended. KIND
+ indicates which particular sizetype to create. */
tree
-size_int_type_wide (number, type)
- HOST_WIDE_INT number;
- tree type;
+size_int_kind (HOST_WIDE_INT number, enum size_type_kind kind)
{
- static htab_t size_htab = 0;
- static tree new_const = 0;
- PTR *slot;
-
- if (size_htab == 0)
- {
- size_htab = htab_create (1024, size_htab_hash, size_htab_eq, NULL);
- ggc_add_deletable_htab (size_htab, NULL, NULL);
- new_const = make_node (INTEGER_CST);
- ggc_add_tree_root (&new_const, 1);
- }
-
- /* Adjust NEW_CONST to be the constant we want. If it's already in the
- hash table, we return the value from the hash table. Otherwise, we
- place that in the hash table and make a new node for the next time. */
- TREE_INT_CST_LOW (new_const) = number;
- TREE_INT_CST_HIGH (new_const) = number < 0 ? -1 : 0;
- TREE_TYPE (new_const) = type;
- TREE_OVERFLOW (new_const) = TREE_CONSTANT_OVERFLOW (new_const)
- = force_fit_type (new_const, 0);
-
- slot = htab_find_slot (size_htab, new_const, INSERT);
- if (*slot == 0)
- {
- tree t = new_const;
-
- *slot = (PTR) new_const;
- new_const = make_node (INTEGER_CST);
- return t;
- }
- else
- return (tree) *slot;
+ return build_int_cst (sizetype_tab[(int) kind], number);
}
-
+\f
/* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
is a tree code. The type of the result is taken from the operands.
- Both must be the same type integer type and it must be a size type.
+ Both must be equivalent integer types, ala int_binop_types_match_p.
If the operands are constant, so is the result. */
tree
-size_binop (code, arg0, arg1)
- enum tree_code code;
- tree arg0, arg1;
+size_binop (enum tree_code code, tree arg0, tree arg1)
{
tree type = TREE_TYPE (arg0);
- if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
- || type != TREE_TYPE (arg1))
- abort ();
+ if (arg0 == error_mark_node || arg1 == error_mark_node)
+ return error_mark_node;
+
+ gcc_assert (int_binop_types_match_p (code, TREE_TYPE (arg0),
+ TREE_TYPE (arg1)));
/* Handle the special case of two integer constants faster. */
if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
{
/* And some specific cases even faster than that. */
- if (code == PLUS_EXPR && integer_zerop (arg0))
- return arg1;
- else if ((code == MINUS_EXPR || code == PLUS_EXPR)
- && integer_zerop (arg1))
- return arg0;
- else if (code == MULT_EXPR && integer_onep (arg0))
- return arg1;
+ if (code == PLUS_EXPR)
+ {
+ if (integer_zerop (arg0) && !TREE_OVERFLOW (arg0))
+ return arg1;
+ if (integer_zerop (arg1) && !TREE_OVERFLOW (arg1))
+ return arg0;
+ }
+ else if (code == MINUS_EXPR)
+ {
+ if (integer_zerop (arg1) && !TREE_OVERFLOW (arg1))
+ return arg0;
+ }
+ else if (code == MULT_EXPR)
+ {
+ if (integer_onep (arg0) && !TREE_OVERFLOW (arg0))
+ return arg1;
+ }
/* Handle general case of two integer constants. */
return int_const_binop (code, arg0, arg1, 0);
}
- if (arg0 == error_mark_node || arg1 == error_mark_node)
- return error_mark_node;
-
- return fold (build (code, type, arg0, arg1));
+ return fold_build2 (code, type, arg0, arg1);
}
/* Given two values, either both of sizetype or both of bitsizetype,
in signed type corresponding to the type of the operands. */
tree
-size_diffop (arg0, arg1)
- tree arg0, arg1;
+size_diffop (tree arg0, tree arg1)
{
tree type = TREE_TYPE (arg0);
tree ctype;
- if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
- || type != TREE_TYPE (arg1))
- abort ();
+ gcc_assert (int_binop_types_match_p (MINUS_EXPR, TREE_TYPE (arg0),
+ TREE_TYPE (arg1)));
/* If the type is already signed, just do the simple thing. */
- if (! TREE_UNSIGNED (type))
+ if (!TYPE_UNSIGNED (type))
return size_binop (MINUS_EXPR, arg0, arg1);
- ctype = (type == bitsizetype || type == ubitsizetype
- ? sbitsizetype : ssizetype);
+ if (type == sizetype)
+ ctype = ssizetype;
+ else if (type == bitsizetype)
+ ctype = sbitsizetype;
+ else
+ ctype = signed_type_for (type);
/* If either operand is not a constant, do the conversions to the signed
type and subtract. The hardware will do the right thing with any
overflow in the subtraction. */
if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
- return size_binop (MINUS_EXPR, convert (ctype, arg0),
- convert (ctype, arg1));
+ return size_binop (MINUS_EXPR, fold_convert (ctype, arg0),
+ fold_convert (ctype, arg1));
/* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
Otherwise, subtract the other way, convert to CTYPE (we know that can't
overflow) and negate (which can't either). Special-case a result
of zero while we're here. */
if (tree_int_cst_equal (arg0, arg1))
- return convert (ctype, integer_zero_node);
+ return build_int_cst (ctype, 0);
else if (tree_int_cst_lt (arg1, arg0))
- return convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
+ return fold_convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
else
- return size_binop (MINUS_EXPR, convert (ctype, integer_zero_node),
- convert (ctype, size_binop (MINUS_EXPR, arg1, arg0)));
+ return size_binop (MINUS_EXPR, build_int_cst (ctype, 0),
+ fold_convert (ctype, size_binop (MINUS_EXPR,
+ arg1, arg0)));
}
\f
-/* This structure is used to communicate arguments to fold_convert_1. */
-struct fc_args
-{
- tree arg1; /* Input: value to convert. */
- tree type; /* Input: type to convert value to. */
- tree t; /* Output: result of conversion. */
-};
-
-/* Function to convert floating-point constants, protected by floating
- point exception handler. */
+/* A subroutine of fold_convert_const handling conversions of an
+ INTEGER_CST to another integer type. */
-static void
-fold_convert_1 (data)
- PTR data;
+static tree
+fold_convert_const_int_from_int (tree type, const_tree arg1)
{
- struct fc_args *args = (struct fc_args *) data;
+ tree t;
+
+ /* Given an integer constant, make new constant with new type,
+ appropriately sign-extended or truncated. */
+ t = force_fit_type_double (type, TREE_INT_CST_LOW (arg1),
+ TREE_INT_CST_HIGH (arg1),
+ /* Don't set the overflow when
+ converting from a pointer, */
+ !POINTER_TYPE_P (TREE_TYPE (arg1))
+ /* or to a sizetype with same signedness
+ and the precision is unchanged.
+ ??? sizetype is always sign-extended,
+ but its signedness depends on the
+ frontend. Thus we see spurious overflows
+ here if we do not check this. */
+ && !((TYPE_PRECISION (TREE_TYPE (arg1))
+ == TYPE_PRECISION (type))
+ && (TYPE_UNSIGNED (TREE_TYPE (arg1))
+ == TYPE_UNSIGNED (type))
+ && ((TREE_CODE (TREE_TYPE (arg1)) == INTEGER_TYPE
+ && TYPE_IS_SIZETYPE (TREE_TYPE (arg1)))
+ || (TREE_CODE (type) == INTEGER_TYPE
+ && TYPE_IS_SIZETYPE (type)))),
+ (TREE_INT_CST_HIGH (arg1) < 0
+ && (TYPE_UNSIGNED (type)
+ < TYPE_UNSIGNED (TREE_TYPE (arg1))))
+ | TREE_OVERFLOW (arg1));
- args->t = build_real (args->type,
- real_value_truncate (TYPE_MODE (args->type),
- TREE_REAL_CST (args->arg1)));
+ return t;
}
-/* Given T, a tree representing type conversion of ARG1, a constant,
- return a constant tree representing the result of conversion. */
+/* A subroutine of fold_convert_const handling conversions a REAL_CST
+ to an integer type. */
static tree
-fold_convert (t, arg1)
- tree t;
- tree arg1;
+fold_convert_const_int_from_real (enum tree_code code, tree type, const_tree arg1)
{
- tree type = TREE_TYPE (t);
int overflow = 0;
+ tree t;
+
+ /* The following code implements the floating point to integer
+ conversion rules required by the Java Language Specification,
+ that IEEE NaNs are mapped to zero and values that overflow
+ the target precision saturate, i.e. values greater than
+ INT_MAX are mapped to INT_MAX, and values less than INT_MIN
+ are mapped to INT_MIN. These semantics are allowed by the
+ C and C++ standards that simply state that the behavior of
+ FP-to-integer conversion is unspecified upon overflow. */
- if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
+ HOST_WIDE_INT high, low;
+ REAL_VALUE_TYPE r;
+ REAL_VALUE_TYPE x = TREE_REAL_CST (arg1);
+
+ switch (code)
{
- if (TREE_CODE (arg1) == INTEGER_CST)
- {
- /* If we would build a constant wider than GCC supports,
- leave the conversion unfolded. */
- if (TYPE_PRECISION (type) > 2 * HOST_BITS_PER_WIDE_INT)
- return t;
+ case FIX_TRUNC_EXPR:
+ real_trunc (&r, VOIDmode, &x);
+ break;
- /* If we are trying to make a sizetype for a small integer, use
- size_int to pick up cached types to reduce duplicate nodes. */
- if (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
- && !TREE_CONSTANT_OVERFLOW (arg1)
- && compare_tree_int (arg1, 10000) < 0)
- return size_int_type_wide (TREE_INT_CST_LOW (arg1), type);
-
- /* Given an integer constant, make new constant with new type,
- appropriately sign-extended or truncated. */
- t = build_int_2 (TREE_INT_CST_LOW (arg1),
- TREE_INT_CST_HIGH (arg1));
- TREE_TYPE (t) = type;
- /* Indicate an overflow if (1) ARG1 already overflowed,
- or (2) force_fit_type indicates an overflow.
- Tell force_fit_type that an overflow has already occurred
- if ARG1 is a too-large unsigned value and T is signed.
- But don't indicate an overflow if converting a pointer. */
- TREE_OVERFLOW (t)
- = ((force_fit_type (t,
- (TREE_INT_CST_HIGH (arg1) < 0
- && (TREE_UNSIGNED (type)
- < TREE_UNSIGNED (TREE_TYPE (arg1)))))
- && ! POINTER_TYPE_P (TREE_TYPE (arg1)))
- || TREE_OVERFLOW (arg1));
- TREE_CONSTANT_OVERFLOW (t)
- = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
- }
-#if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
- else if (TREE_CODE (arg1) == REAL_CST)
- {
- /* Don't initialize these, use assignments.
- Initialized local aggregates don't work on old compilers. */
- REAL_VALUE_TYPE x;
- REAL_VALUE_TYPE l;
- REAL_VALUE_TYPE u;
- tree type1 = TREE_TYPE (arg1);
- int no_upper_bound;
-
- x = TREE_REAL_CST (arg1);
- l = real_value_from_int_cst (type1, TYPE_MIN_VALUE (type));
-
- no_upper_bound = (TYPE_MAX_VALUE (type) == NULL);
- if (!no_upper_bound)
- u = real_value_from_int_cst (type1, TYPE_MAX_VALUE (type));
-
- /* See if X will be in range after truncation towards 0.
- To compensate for truncation, move the bounds away from 0,
- but reject if X exactly equals the adjusted bounds. */
-#ifdef REAL_ARITHMETIC
- REAL_ARITHMETIC (l, MINUS_EXPR, l, dconst1);
- if (!no_upper_bound)
- REAL_ARITHMETIC (u, PLUS_EXPR, u, dconst1);
-#else
- l--;
- if (!no_upper_bound)
- u++;
-#endif
- /* If X is a NaN, use zero instead and show we have an overflow.
- Otherwise, range check. */
- if (REAL_VALUE_ISNAN (x))
- overflow = 1, x = dconst0;
- else if (! (REAL_VALUES_LESS (l, x)
- && !no_upper_bound
- && REAL_VALUES_LESS (x, u)))
- overflow = 1;
+ default:
+ gcc_unreachable ();
+ }
-#ifndef REAL_ARITHMETIC
- {
- HOST_WIDE_INT low, high;
- HOST_WIDE_INT half_word
- = (HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2);
+ /* If R is NaN, return zero and show we have an overflow. */
+ if (REAL_VALUE_ISNAN (r))
+ {
+ overflow = 1;
+ high = 0;
+ low = 0;
+ }
- if (x < 0)
- x = -x;
+ /* See if R is less than the lower bound or greater than the
+ upper bound. */
- high = (HOST_WIDE_INT) (x / half_word / half_word);
- x -= (REAL_VALUE_TYPE) high * half_word * half_word;
- if (x >= (REAL_VALUE_TYPE) half_word * half_word / 2)
- {
- low = x - (REAL_VALUE_TYPE) half_word * half_word / 2;
- low |= (HOST_WIDE_INT) -1 << (HOST_BITS_PER_WIDE_INT - 1);
- }
- else
- low = (HOST_WIDE_INT) x;
- if (TREE_REAL_CST (arg1) < 0)
- neg_double (low, high, &low, &high);
- t = build_int_2 (low, high);
- }
-#else
- {
- HOST_WIDE_INT low, high;
- REAL_VALUE_TO_INT (&low, &high, x);
- t = build_int_2 (low, high);
- }
-#endif
- TREE_TYPE (t) = type;
- TREE_OVERFLOW (t)
- = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
- TREE_CONSTANT_OVERFLOW (t)
- = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
+ if (! overflow)
+ {
+ tree lt = TYPE_MIN_VALUE (type);
+ REAL_VALUE_TYPE l = real_value_from_int_cst (NULL_TREE, lt);
+ if (REAL_VALUES_LESS (r, l))
+ {
+ overflow = 1;
+ high = TREE_INT_CST_HIGH (lt);
+ low = TREE_INT_CST_LOW (lt);
+ }
+ }
+
+ if (! overflow)
+ {
+ tree ut = TYPE_MAX_VALUE (type);
+ if (ut)
+ {
+ REAL_VALUE_TYPE u = real_value_from_int_cst (NULL_TREE, ut);
+ if (REAL_VALUES_LESS (u, r))
+ {
+ overflow = 1;
+ high = TREE_INT_CST_HIGH (ut);
+ low = TREE_INT_CST_LOW (ut);
+ }
}
-#endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
- TREE_TYPE (t) = type;
+ }
+
+ if (! overflow)
+ REAL_VALUE_TO_INT (&low, &high, r);
+
+ t = force_fit_type_double (type, low, high, -1,
+ overflow | TREE_OVERFLOW (arg1));
+ return t;
+}
+
+/* A subroutine of fold_convert_const handling conversions of a
+ FIXED_CST to an integer type. */
+
+static tree
+fold_convert_const_int_from_fixed (tree type, const_tree arg1)
+{
+ tree t;
+ double_int temp, temp_trunc;
+ unsigned int mode;
+
+ /* Right shift FIXED_CST to temp by fbit. */
+ temp = TREE_FIXED_CST (arg1).data;
+ mode = TREE_FIXED_CST (arg1).mode;
+ if (GET_MODE_FBIT (mode) < 2 * HOST_BITS_PER_WIDE_INT)
+ {
+ lshift_double (temp.low, temp.high,
+ - GET_MODE_FBIT (mode), 2 * HOST_BITS_PER_WIDE_INT,
+ &temp.low, &temp.high, SIGNED_FIXED_POINT_MODE_P (mode));
+
+ /* Left shift temp to temp_trunc by fbit. */
+ lshift_double (temp.low, temp.high,
+ GET_MODE_FBIT (mode), 2 * HOST_BITS_PER_WIDE_INT,
+ &temp_trunc.low, &temp_trunc.high,
+ SIGNED_FIXED_POINT_MODE_P (mode));
+ }
+ else
+ {
+ temp.low = 0;
+ temp.high = 0;
+ temp_trunc.low = 0;
+ temp_trunc.high = 0;
+ }
+
+ /* If FIXED_CST is negative, we need to round the value toward 0.
+ By checking if the fractional bits are not zero to add 1 to temp. */
+ if (SIGNED_FIXED_POINT_MODE_P (mode) && temp_trunc.high < 0
+ && !double_int_equal_p (TREE_FIXED_CST (arg1).data, temp_trunc))
+ {
+ double_int one;
+ one.low = 1;
+ one.high = 0;
+ temp = double_int_add (temp, one);
+ }
+
+ /* Given a fixed-point constant, make new constant with new type,
+ appropriately sign-extended or truncated. */
+ t = force_fit_type_double (type, temp.low, temp.high, -1,
+ (temp.high < 0
+ && (TYPE_UNSIGNED (type)
+ < TYPE_UNSIGNED (TREE_TYPE (arg1))))
+ | TREE_OVERFLOW (arg1));
+
+ return t;
+}
+
+/* A subroutine of fold_convert_const handling conversions a REAL_CST
+ to another floating point type. */
+
+static tree
+fold_convert_const_real_from_real (tree type, const_tree arg1)
+{
+ REAL_VALUE_TYPE value;
+ tree t;
+
+ real_convert (&value, TYPE_MODE (type), &TREE_REAL_CST (arg1));
+ t = build_real (type, value);
+
+ TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1);
+ return t;
+}
+
+/* A subroutine of fold_convert_const handling conversions a FIXED_CST
+ to a floating point type. */
+
+static tree
+fold_convert_const_real_from_fixed (tree type, const_tree arg1)
+{
+ REAL_VALUE_TYPE value;
+ tree t;
+
+ real_convert_from_fixed (&value, TYPE_MODE (type), &TREE_FIXED_CST (arg1));
+ t = build_real (type, value);
+
+ TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1);
+ TREE_CONSTANT_OVERFLOW (t)
+ = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
+ return t;
+}
+
+/* A subroutine of fold_convert_const handling conversions a FIXED_CST
+ to another fixed-point type. */
+
+static tree
+fold_convert_const_fixed_from_fixed (tree type, const_tree arg1)
+{
+ FIXED_VALUE_TYPE value;
+ tree t;
+ bool overflow_p;
+
+ overflow_p = fixed_convert (&value, TYPE_MODE (type), &TREE_FIXED_CST (arg1),
+ TYPE_SATURATING (type));
+ t = build_fixed (type, value);
+
+ /* Propagate overflow flags. */
+ if (overflow_p | TREE_OVERFLOW (arg1))
+ {
+ TREE_OVERFLOW (t) = 1;
+ TREE_CONSTANT_OVERFLOW (t) = 1;
+ }
+ else if (TREE_CONSTANT_OVERFLOW (arg1))
+ TREE_CONSTANT_OVERFLOW (t) = 1;
+ return t;
+}
+
+/* A subroutine of fold_convert_const handling conversions an INTEGER_CST
+ to a fixed-point type. */
+
+static tree
+fold_convert_const_fixed_from_int (tree type, const_tree arg1)
+{
+ FIXED_VALUE_TYPE value;
+ tree t;
+ bool overflow_p;
+
+ overflow_p = fixed_convert_from_int (&value, TYPE_MODE (type),
+ TREE_INT_CST (arg1),
+ TYPE_UNSIGNED (TREE_TYPE (arg1)),
+ TYPE_SATURATING (type));
+ t = build_fixed (type, value);
+
+ /* Propagate overflow flags. */
+ if (overflow_p | TREE_OVERFLOW (arg1))
+ {
+ TREE_OVERFLOW (t) = 1;
+ TREE_CONSTANT_OVERFLOW (t) = 1;
+ }
+ else if (TREE_CONSTANT_OVERFLOW (arg1))
+ TREE_CONSTANT_OVERFLOW (t) = 1;
+ return t;
+}
+
+/* A subroutine of fold_convert_const handling conversions a REAL_CST
+ to a fixed-point type. */
+
+static tree
+fold_convert_const_fixed_from_real (tree type, const_tree arg1)
+{
+ FIXED_VALUE_TYPE value;
+ tree t;
+ bool overflow_p;
+
+ overflow_p = fixed_convert_from_real (&value, TYPE_MODE (type),
+ &TREE_REAL_CST (arg1),
+ TYPE_SATURATING (type));
+ t = build_fixed (type, value);
+
+ /* Propagate overflow flags. */
+ if (overflow_p | TREE_OVERFLOW (arg1))
+ {
+ TREE_OVERFLOW (t) = 1;
+ TREE_CONSTANT_OVERFLOW (t) = 1;
+ }
+ else if (TREE_CONSTANT_OVERFLOW (arg1))
+ TREE_CONSTANT_OVERFLOW (t) = 1;
+ return t;
+}
+
+/* Attempt to fold type conversion operation CODE of expression ARG1 to
+ type TYPE. If no simplification can be done return NULL_TREE. */
+
+static tree
+fold_convert_const (enum tree_code code, tree type, tree arg1)
+{
+ if (TREE_TYPE (arg1) == type)
+ return arg1;
+
+ if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type)
+ || TREE_CODE (type) == OFFSET_TYPE)
+ {
+ if (TREE_CODE (arg1) == INTEGER_CST)
+ return fold_convert_const_int_from_int (type, arg1);
+ else if (TREE_CODE (arg1) == REAL_CST)
+ return fold_convert_const_int_from_real (code, type, arg1);
+ else if (TREE_CODE (arg1) == FIXED_CST)
+ return fold_convert_const_int_from_fixed (type, arg1);
}
else if (TREE_CODE (type) == REAL_TYPE)
{
-#if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
if (TREE_CODE (arg1) == INTEGER_CST)
return build_real_from_int_cst (type, arg1);
-#endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
- if (TREE_CODE (arg1) == REAL_CST)
+ else if (TREE_CODE (arg1) == REAL_CST)
+ return fold_convert_const_real_from_real (type, arg1);
+ else if (TREE_CODE (arg1) == FIXED_CST)
+ return fold_convert_const_real_from_fixed (type, arg1);
+ }
+ else if (TREE_CODE (type) == FIXED_POINT_TYPE)
+ {
+ if (TREE_CODE (arg1) == FIXED_CST)
+ return fold_convert_const_fixed_from_fixed (type, arg1);
+ else if (TREE_CODE (arg1) == INTEGER_CST)
+ return fold_convert_const_fixed_from_int (type, arg1);
+ else if (TREE_CODE (arg1) == REAL_CST)
+ return fold_convert_const_fixed_from_real (type, arg1);
+ }
+ return NULL_TREE;
+}
+
+/* Construct a vector of zero elements of vector type TYPE. */
+
+static tree
+build_zero_vector (tree type)
+{
+ tree elem, list;
+ int i, units;
+
+ elem = fold_convert_const (NOP_EXPR, TREE_TYPE (type), integer_zero_node);
+ units = TYPE_VECTOR_SUBPARTS (type);
+
+ list = NULL_TREE;
+ for (i = 0; i < units; i++)
+ list = tree_cons (NULL_TREE, elem, list);
+ return build_vector (type, list);
+}
+
+/* Returns true, if ARG is convertible to TYPE using a NOP_EXPR. */
+
+bool
+fold_convertible_p (const_tree type, const_tree arg)
+{
+ tree orig = TREE_TYPE (arg);
+
+ if (type == orig)
+ return true;
+
+ if (TREE_CODE (arg) == ERROR_MARK
+ || TREE_CODE (type) == ERROR_MARK
+ || TREE_CODE (orig) == ERROR_MARK)
+ return false;
+
+ if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig))
+ return true;
+
+ switch (TREE_CODE (type))
+ {
+ case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
+ case POINTER_TYPE: case REFERENCE_TYPE:
+ case OFFSET_TYPE:
+ if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
+ || TREE_CODE (orig) == OFFSET_TYPE)
+ return true;
+ return (TREE_CODE (orig) == VECTOR_TYPE
+ && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
+
+ case REAL_TYPE:
+ case FIXED_POINT_TYPE:
+ case COMPLEX_TYPE:
+ case VECTOR_TYPE:
+ case VOID_TYPE:
+ return TREE_CODE (type) == TREE_CODE (orig);
+
+ default:
+ return false;
+ }
+}
+
+/* Convert expression ARG to type TYPE. Used by the middle-end for
+ simple conversions in preference to calling the front-end's convert. */
+
+tree
+fold_convert (tree type, tree arg)
+{
+ tree orig = TREE_TYPE (arg);
+ tree tem;
+
+ if (type == orig)
+ return arg;
+
+ if (TREE_CODE (arg) == ERROR_MARK
+ || TREE_CODE (type) == ERROR_MARK
+ || TREE_CODE (orig) == ERROR_MARK)
+ return error_mark_node;
+
+ if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig))
+ return fold_build1 (NOP_EXPR, type, arg);
+
+ switch (TREE_CODE (type))
+ {
+ case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
+ case POINTER_TYPE: case REFERENCE_TYPE:
+ case OFFSET_TYPE:
+ if (TREE_CODE (arg) == INTEGER_CST)
+ {
+ tem = fold_convert_const (NOP_EXPR, type, arg);
+ if (tem != NULL_TREE)
+ return tem;
+ }
+ if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
+ || TREE_CODE (orig) == OFFSET_TYPE)
+ return fold_build1 (NOP_EXPR, type, arg);
+ if (TREE_CODE (orig) == COMPLEX_TYPE)
{
- struct fc_args args;
+ tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
+ return fold_convert (type, tem);
+ }
+ gcc_assert (TREE_CODE (orig) == VECTOR_TYPE
+ && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
+ return fold_build1 (NOP_EXPR, type, arg);
- if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
- {
- t = arg1;
- TREE_TYPE (arg1) = type;
- return t;
- }
+ case REAL_TYPE:
+ if (TREE_CODE (arg) == INTEGER_CST)
+ {
+ tem = fold_convert_const (FLOAT_EXPR, type, arg);
+ if (tem != NULL_TREE)
+ return tem;
+ }
+ else if (TREE_CODE (arg) == REAL_CST)
+ {
+ tem = fold_convert_const (NOP_EXPR, type, arg);
+ if (tem != NULL_TREE)
+ return tem;
+ }
+ else if (TREE_CODE (arg) == FIXED_CST)
+ {
+ tem = fold_convert_const (FIXED_CONVERT_EXPR, type, arg);
+ if (tem != NULL_TREE)
+ return tem;
+ }
+
+ switch (TREE_CODE (orig))
+ {
+ case INTEGER_TYPE:
+ case BOOLEAN_TYPE: case ENUMERAL_TYPE:
+ case POINTER_TYPE: case REFERENCE_TYPE:
+ return fold_build1 (FLOAT_EXPR, type, arg);
- /* Setup input for fold_convert_1() */
- args.arg1 = arg1;
- args.type = type;
+ case REAL_TYPE:
+ return fold_build1 (NOP_EXPR, type, arg);
- if (do_float_handler (fold_convert_1, (PTR) &args))
- {
- /* Receive output from fold_convert_1() */
- t = args.t;
- }
- else
- {
- /* We got an exception from fold_convert_1() */
- overflow = 1;
- t = copy_node (arg1);
- }
+ case FIXED_POINT_TYPE:
+ return fold_build1 (FIXED_CONVERT_EXPR, type, arg);
- TREE_OVERFLOW (t)
- = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
- TREE_CONSTANT_OVERFLOW (t)
- = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
- return t;
+ case COMPLEX_TYPE:
+ tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
+ return fold_convert (type, tem);
+
+ default:
+ gcc_unreachable ();
+ }
+
+ case FIXED_POINT_TYPE:
+ if (TREE_CODE (arg) == FIXED_CST || TREE_CODE (arg) == INTEGER_CST
+ || TREE_CODE (arg) == REAL_CST)
+ {
+ tem = fold_convert_const (FIXED_CONVERT_EXPR, type, arg);
+ if (tem != NULL_TREE)
+ return tem;
+ }
+
+ switch (TREE_CODE (orig))
+ {
+ case FIXED_POINT_TYPE:
+ case INTEGER_TYPE:
+ case ENUMERAL_TYPE:
+ case BOOLEAN_TYPE:
+ case REAL_TYPE:
+ return fold_build1 (FIXED_CONVERT_EXPR, type, arg);
+
+ case COMPLEX_TYPE:
+ tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
+ return fold_convert (type, tem);
+
+ default:
+ gcc_unreachable ();
+ }
+
+ case COMPLEX_TYPE:
+ switch (TREE_CODE (orig))
+ {
+ case INTEGER_TYPE:
+ case BOOLEAN_TYPE: case ENUMERAL_TYPE:
+ case POINTER_TYPE: case REFERENCE_TYPE:
+ case REAL_TYPE:
+ case FIXED_POINT_TYPE:
+ return fold_build2 (COMPLEX_EXPR, type,
+ fold_convert (TREE_TYPE (type), arg),
+ fold_convert (TREE_TYPE (type),
+ integer_zero_node));
+ case COMPLEX_TYPE:
+ {
+ tree rpart, ipart;
+
+ if (TREE_CODE (arg) == COMPLEX_EXPR)
+ {
+ rpart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 0));
+ ipart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 1));
+ return fold_build2 (COMPLEX_EXPR, type, rpart, ipart);
+ }
+
+ arg = save_expr (arg);
+ rpart = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
+ ipart = fold_build1 (IMAGPART_EXPR, TREE_TYPE (orig), arg);
+ rpart = fold_convert (TREE_TYPE (type), rpart);
+ ipart = fold_convert (TREE_TYPE (type), ipart);
+ return fold_build2 (COMPLEX_EXPR, type, rpart, ipart);
+ }
+
+ default:
+ gcc_unreachable ();
}
+
+ case VECTOR_TYPE:
+ if (integer_zerop (arg))
+ return build_zero_vector (type);
+ gcc_assert (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
+ gcc_assert (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
+ || TREE_CODE (orig) == VECTOR_TYPE);
+ return fold_build1 (VIEW_CONVERT_EXPR, type, arg);
+
+ case VOID_TYPE:
+ tem = fold_ignored_result (arg);
+ if (TREE_CODE (tem) == MODIFY_EXPR)
+ return tem;
+ return fold_build1 (NOP_EXPR, type, tem);
+
+ default:
+ gcc_unreachable ();
}
- TREE_CONSTANT (t) = 1;
- return t;
}
\f
+/* Return false if expr can be assumed not to be an lvalue, true
+ otherwise. */
+
+static bool
+maybe_lvalue_p (const_tree x)
+{
+ /* We only need to wrap lvalue tree codes. */
+ switch (TREE_CODE (x))
+ {
+ case VAR_DECL:
+ case PARM_DECL:
+ case RESULT_DECL:
+ case LABEL_DECL:
+ case FUNCTION_DECL:
+ case SSA_NAME:
+
+ case COMPONENT_REF:
+ case INDIRECT_REF:
+ case ALIGN_INDIRECT_REF:
+ case MISALIGNED_INDIRECT_REF:
+ case ARRAY_REF:
+ case ARRAY_RANGE_REF:
+ case BIT_FIELD_REF:
+ case OBJ_TYPE_REF:
+
+ case REALPART_EXPR:
+ case IMAGPART_EXPR:
+ case PREINCREMENT_EXPR:
+ case PREDECREMENT_EXPR:
+ case SAVE_EXPR:
+ case TRY_CATCH_EXPR:
+ case WITH_CLEANUP_EXPR:
+ case COMPOUND_EXPR:
+ case MODIFY_EXPR:
+ case TARGET_EXPR:
+ case COND_EXPR:
+ case BIND_EXPR:
+ case MIN_EXPR:
+ case MAX_EXPR:
+ break;
+
+ default:
+ /* Assume the worst for front-end tree codes. */
+ if ((int)TREE_CODE (x) >= NUM_TREE_CODES)
+ break;
+ return false;
+ }
+
+ return true;
+}
+
/* Return an expr equal to X but certainly not valid as an lvalue. */
tree
-non_lvalue (x)
- tree x;
+non_lvalue (tree x)
{
- tree result;
-
- /* These things are certainly not lvalues. */
- if (TREE_CODE (x) == NON_LVALUE_EXPR
- || TREE_CODE (x) == INTEGER_CST
- || TREE_CODE (x) == REAL_CST
- || TREE_CODE (x) == STRING_CST
- || TREE_CODE (x) == ADDR_EXPR)
+ /* While we are in GIMPLE, NON_LVALUE_EXPR doesn't mean anything to
+ us. */
+ if (in_gimple_form)
return x;
- result = build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
- TREE_CONSTANT (result) = TREE_CONSTANT (x);
- return result;
+ if (! maybe_lvalue_p (x))
+ return x;
+ return build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
}
/* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
/* When pedantic, return an expr equal to X but certainly not valid as a
pedantic lvalue. Otherwise, return X. */
-tree
-pedantic_non_lvalue (x)
- tree x;
+static tree
+pedantic_non_lvalue (tree x)
{
if (pedantic_lvalues)
return non_lvalue (x);
\f
/* Given a tree comparison code, return the code that is the logical inverse
of the given code. It is not safe to do this for floating-point
- comparisons, except for NE_EXPR and EQ_EXPR. */
+ comparisons, except for NE_EXPR and EQ_EXPR, so we receive a machine mode
+ as well: if reversing the comparison is unsafe, return ERROR_MARK. */
-static enum tree_code
-invert_tree_comparison (code)
- enum tree_code code;
+enum tree_code
+invert_tree_comparison (enum tree_code code, bool honor_nans)
{
+ if (honor_nans && flag_trapping_math)
+ return ERROR_MARK;
+
switch (code)
{
case EQ_EXPR:
case NE_EXPR:
return EQ_EXPR;
case GT_EXPR:
- return LE_EXPR;
+ return honor_nans ? UNLE_EXPR : LE_EXPR;
case GE_EXPR:
- return LT_EXPR;
+ return honor_nans ? UNLT_EXPR : LT_EXPR;
case LT_EXPR:
- return GE_EXPR;
+ return honor_nans ? UNGE_EXPR : GE_EXPR;
case LE_EXPR:
+ return honor_nans ? UNGT_EXPR : GT_EXPR;
+ case LTGT_EXPR:
+ return UNEQ_EXPR;
+ case UNEQ_EXPR:
+ return LTGT_EXPR;
+ case UNGT_EXPR:
+ return LE_EXPR;
+ case UNGE_EXPR:
+ return LT_EXPR;
+ case UNLT_EXPR:
+ return GE_EXPR;
+ case UNLE_EXPR:
return GT_EXPR;
+ case ORDERED_EXPR:
+ return UNORDERED_EXPR;
+ case UNORDERED_EXPR:
+ return ORDERED_EXPR;
default:
- abort ();
+ gcc_unreachable ();
}
}
/* Similar, but return the comparison that results if the operands are
swapped. This is safe for floating-point. */
-static enum tree_code
-swap_tree_comparison (code)
- enum tree_code code;
+enum tree_code
+swap_tree_comparison (enum tree_code code)
{
switch (code)
{
case EQ_EXPR:
case NE_EXPR:
+ case ORDERED_EXPR:
+ case UNORDERED_EXPR:
+ case LTGT_EXPR:
+ case UNEQ_EXPR:
return code;
case GT_EXPR:
return LT_EXPR;
return GT_EXPR;
case LE_EXPR:
return GE_EXPR;
+ case UNGT_EXPR:
+ return UNLT_EXPR;
+ case UNGE_EXPR:
+ return UNLE_EXPR;
+ case UNLT_EXPR:
+ return UNGT_EXPR;
+ case UNLE_EXPR:
+ return UNGE_EXPR;
default:
- abort ();
+ gcc_unreachable ();
}
}
-/* Return nonzero if CODE is a tree code that represents a truth value. */
-static int
-truth_value_p (code)
- enum tree_code code;
+/* Convert a comparison tree code from an enum tree_code representation
+ into a compcode bit-based encoding. This function is the inverse of
+ compcode_to_comparison. */
+
+static enum comparison_code
+comparison_to_compcode (enum tree_code code)
{
- return (TREE_CODE_CLASS (code) == '<'
- || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
- || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
- || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
+ switch (code)
+ {
+ case LT_EXPR:
+ return COMPCODE_LT;
+ case EQ_EXPR:
+ return COMPCODE_EQ;
+ case LE_EXPR:
+ return COMPCODE_LE;
+ case GT_EXPR:
+ return COMPCODE_GT;
+ case NE_EXPR:
+ return COMPCODE_NE;
+ case GE_EXPR:
+ return COMPCODE_GE;
+ case ORDERED_EXPR:
+ return COMPCODE_ORD;
+ case UNORDERED_EXPR:
+ return COMPCODE_UNORD;
+ case UNLT_EXPR:
+ return COMPCODE_UNLT;
+ case UNEQ_EXPR:
+ return COMPCODE_UNEQ;
+ case UNLE_EXPR:
+ return COMPCODE_UNLE;
+ case UNGT_EXPR:
+ return COMPCODE_UNGT;
+ case LTGT_EXPR:
+ return COMPCODE_LTGT;
+ case UNGE_EXPR:
+ return COMPCODE_UNGE;
+ default:
+ gcc_unreachable ();
+ }
}
-\f
-/* Return nonzero if two operands are necessarily equal.
- If ONLY_CONST is non-zero, only return non-zero for constants.
- This function tests whether the operands are indistinguishable;
- it does not test whether they are equal using C's == operation.
- The distinction is important for IEEE floating point, because
- (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
- (2) two NaNs may be indistinguishable, but NaN!=NaN. */
-int
-operand_equal_p (arg0, arg1, only_const)
- tree arg0, arg1;
- int only_const;
+/* Convert a compcode bit-based encoding of a comparison operator back
+ to GCC's enum tree_code representation. This function is the
+ inverse of comparison_to_compcode. */
+
+static enum tree_code
+compcode_to_comparison (enum comparison_code code)
{
- /* If both types don't have the same signedness, then we can't consider
- them equal. We must check this before the STRIP_NOPS calls
- because they may change the signedness of the arguments. */
- if (TREE_UNSIGNED (TREE_TYPE (arg0)) != TREE_UNSIGNED (TREE_TYPE (arg1)))
- return 0;
+ switch (code)
+ {
+ case COMPCODE_LT:
+ return LT_EXPR;
+ case COMPCODE_EQ:
+ return EQ_EXPR;
+ case COMPCODE_LE:
+ return LE_EXPR;
+ case COMPCODE_GT:
+ return GT_EXPR;
+ case COMPCODE_NE:
+ return NE_EXPR;
+ case COMPCODE_GE:
+ return GE_EXPR;
+ case COMPCODE_ORD:
+ return ORDERED_EXPR;
+ case COMPCODE_UNORD:
+ return UNORDERED_EXPR;
+ case COMPCODE_UNLT:
+ return UNLT_EXPR;
+ case COMPCODE_UNEQ:
+ return UNEQ_EXPR;
+ case COMPCODE_UNLE:
+ return UNLE_EXPR;
+ case COMPCODE_UNGT:
+ return UNGT_EXPR;
+ case COMPCODE_LTGT:
+ return LTGT_EXPR;
+ case COMPCODE_UNGE:
+ return UNGE_EXPR;
+ default:
+ gcc_unreachable ();
+ }
+}
- STRIP_NOPS (arg0);
- STRIP_NOPS (arg1);
+/* Return a tree for the comparison which is the combination of
+ doing the AND or OR (depending on CODE) of the two operations LCODE
+ and RCODE on the identical operands LL_ARG and LR_ARG. Take into account
+ the possibility of trapping if the mode has NaNs, and return NULL_TREE
+ if this makes the transformation invalid. */
- if (TREE_CODE (arg0) != TREE_CODE (arg1)
- /* This is needed for conversions and for COMPONENT_REF.
- Might as well play it safe and always test this. */
- || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
- || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
- || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
- return 0;
+tree
+combine_comparisons (enum tree_code code, enum tree_code lcode,
+ enum tree_code rcode, tree truth_type,
+ tree ll_arg, tree lr_arg)
+{
+ bool honor_nans = HONOR_NANS (TYPE_MODE (TREE_TYPE (ll_arg)));
+ enum comparison_code lcompcode = comparison_to_compcode (lcode);
+ enum comparison_code rcompcode = comparison_to_compcode (rcode);
+ enum comparison_code compcode;
- /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
+ switch (code)
+ {
+ case TRUTH_AND_EXPR: case TRUTH_ANDIF_EXPR:
+ compcode = lcompcode & rcompcode;
+ break;
+
+ case TRUTH_OR_EXPR: case TRUTH_ORIF_EXPR:
+ compcode = lcompcode | rcompcode;
+ break;
+
+ default:
+ return NULL_TREE;
+ }
+
+ if (!honor_nans)
+ {
+ /* Eliminate unordered comparisons, as well as LTGT and ORD
+ which are not used unless the mode has NaNs. */
+ compcode &= ~COMPCODE_UNORD;
+ if (compcode == COMPCODE_LTGT)
+ compcode = COMPCODE_NE;
+ else if (compcode == COMPCODE_ORD)
+ compcode = COMPCODE_TRUE;
+ }
+ else if (flag_trapping_math)
+ {
+ /* Check that the original operation and the optimized ones will trap
+ under the same condition. */
+ bool ltrap = (lcompcode & COMPCODE_UNORD) == 0
+ && (lcompcode != COMPCODE_EQ)
+ && (lcompcode != COMPCODE_ORD);
+ bool rtrap = (rcompcode & COMPCODE_UNORD) == 0
+ && (rcompcode != COMPCODE_EQ)
+ && (rcompcode != COMPCODE_ORD);
+ bool trap = (compcode & COMPCODE_UNORD) == 0
+ && (compcode != COMPCODE_EQ)
+ && (compcode != COMPCODE_ORD);
+
+ /* In a short-circuited boolean expression the LHS might be
+ such that the RHS, if evaluated, will never trap. For
+ example, in ORD (x, y) && (x < y), we evaluate the RHS only
+ if neither x nor y is NaN. (This is a mixed blessing: for
+ example, the expression above will never trap, hence
+ optimizing it to x < y would be invalid). */
+ if ((code == TRUTH_ORIF_EXPR && (lcompcode & COMPCODE_UNORD))
+ || (code == TRUTH_ANDIF_EXPR && !(lcompcode & COMPCODE_UNORD)))
+ rtrap = false;
+
+ /* If the comparison was short-circuited, and only the RHS
+ trapped, we may now generate a spurious trap. */
+ if (rtrap && !ltrap
+ && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
+ return NULL_TREE;
+
+ /* If we changed the conditions that cause a trap, we lose. */
+ if ((ltrap || rtrap) != trap)
+ return NULL_TREE;
+ }
+
+ if (compcode == COMPCODE_TRUE)
+ return constant_boolean_node (true, truth_type);
+ else if (compcode == COMPCODE_FALSE)
+ return constant_boolean_node (false, truth_type);
+ else
+ return fold_build2 (compcode_to_comparison (compcode),
+ truth_type, ll_arg, lr_arg);
+}
+\f
+/* Return nonzero if two operands (typically of the same tree node)
+ are necessarily equal. If either argument has side-effects this
+ function returns zero. FLAGS modifies behavior as follows:
+
+ If OEP_ONLY_CONST is set, only return nonzero for constants.
+ This function tests whether the operands are indistinguishable;
+ it does not test whether they are equal using C's == operation.
+ The distinction is important for IEEE floating point, because
+ (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
+ (2) two NaNs may be indistinguishable, but NaN!=NaN.
+
+ If OEP_ONLY_CONST is unset, a VAR_DECL is considered equal to itself
+ even though it may hold multiple values during a function.
+ This is because a GCC tree node guarantees that nothing else is
+ executed between the evaluation of its "operands" (which may often
+ be evaluated in arbitrary order). Hence if the operands themselves
+ don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
+ same value in each operand/subexpression. Hence leaving OEP_ONLY_CONST
+ unset means assuming isochronic (or instantaneous) tree equivalence.
+ Unless comparing arbitrary expression trees, such as from different
+ statements, this flag can usually be left unset.
+
+ If OEP_PURE_SAME is set, then pure functions with identical arguments
+ are considered the same. It is used when the caller has other ways
+ to ensure that global memory is unchanged in between. */
+
+int
+operand_equal_p (const_tree arg0, const_tree arg1, unsigned int flags)
+{
+ /* If either is ERROR_MARK, they aren't equal. */
+ if (TREE_CODE (arg0) == ERROR_MARK || TREE_CODE (arg1) == ERROR_MARK)
+ return 0;
+
+ /* Check equality of integer constants before bailing out due to
+ precision differences. */
+ if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
+ return tree_int_cst_equal (arg0, arg1);
+
+ /* If both types don't have the same signedness, then we can't consider
+ them equal. We must check this before the STRIP_NOPS calls
+ because they may change the signedness of the arguments. As pointers
+ strictly don't have a signedness, require either two pointers or
+ two non-pointers as well. */
+ if (TYPE_UNSIGNED (TREE_TYPE (arg0)) != TYPE_UNSIGNED (TREE_TYPE (arg1))
+ || POINTER_TYPE_P (TREE_TYPE (arg0)) != POINTER_TYPE_P (TREE_TYPE (arg1)))
+ return 0;
+
+ /* If both types don't have the same precision, then it is not safe
+ to strip NOPs. */
+ if (TYPE_PRECISION (TREE_TYPE (arg0)) != TYPE_PRECISION (TREE_TYPE (arg1)))
+ return 0;
+
+ STRIP_NOPS (arg0);
+ STRIP_NOPS (arg1);
+
+ /* In case both args are comparisons but with different comparison
+ code, try to swap the comparison operands of one arg to produce
+ a match and compare that variant. */
+ if (TREE_CODE (arg0) != TREE_CODE (arg1)
+ && COMPARISON_CLASS_P (arg0)
+ && COMPARISON_CLASS_P (arg1))
+ {
+ enum tree_code swap_code = swap_tree_comparison (TREE_CODE (arg1));
+
+ if (TREE_CODE (arg0) == swap_code)
+ return operand_equal_p (TREE_OPERAND (arg0, 0),
+ TREE_OPERAND (arg1, 1), flags)
+ && operand_equal_p (TREE_OPERAND (arg0, 1),
+ TREE_OPERAND (arg1, 0), flags);
+ }
+
+ if (TREE_CODE (arg0) != TREE_CODE (arg1)
+ /* This is needed for conversions and for COMPONENT_REF.
+ Might as well play it safe and always test this. */
+ || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
+ || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
+ || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
+ return 0;
+
+ /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
We don't care about side effects in that case because the SAVE_EXPR
takes care of that for us. In all other cases, two expressions are
equal if they have no side effects. If we have two identical
expressions with side effects that should be treated the same due
to the only side effects being identical SAVE_EXPR's, that will
be detected in the recursive calls below. */
- if (arg0 == arg1 && ! only_const
+ if (arg0 == arg1 && ! (flags & OEP_ONLY_CONST)
&& (TREE_CODE (arg0) == SAVE_EXPR
|| (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
return 1;
switch (TREE_CODE (arg0))
{
case INTEGER_CST:
- return (! TREE_CONSTANT_OVERFLOW (arg0)
- && ! TREE_CONSTANT_OVERFLOW (arg1)
- && tree_int_cst_equal (arg0, arg1));
+ return tree_int_cst_equal (arg0, arg1);
+
+ case FIXED_CST:
+ return FIXED_VALUES_IDENTICAL (TREE_FIXED_CST (arg0),
+ TREE_FIXED_CST (arg1));
case REAL_CST:
- return (! TREE_CONSTANT_OVERFLOW (arg0)
- && ! TREE_CONSTANT_OVERFLOW (arg1)
- && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
- TREE_REAL_CST (arg1)));
+ if (REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
+ TREE_REAL_CST (arg1)))
+ return 1;
+
+
+ if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0))))
+ {
+ /* If we do not distinguish between signed and unsigned zero,
+ consider them equal. */
+ if (real_zerop (arg0) && real_zerop (arg1))
+ return 1;
+ }
+ return 0;
case VECTOR_CST:
{
tree v1, v2;
- if (TREE_CONSTANT_OVERFLOW (arg0)
- || TREE_CONSTANT_OVERFLOW (arg1))
- return 0;
-
v1 = TREE_VECTOR_CST_ELTS (arg0);
v2 = TREE_VECTOR_CST_ELTS (arg1);
while (v1 && v2)
{
- if (!operand_equal_p (v1, v2, only_const))
+ if (!operand_equal_p (TREE_VALUE (v1), TREE_VALUE (v2),
+ flags))
return 0;
v1 = TREE_CHAIN (v1);
v2 = TREE_CHAIN (v2);
}
- return 1;
+ return v1 == v2;
}
case COMPLEX_CST:
return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
- only_const)
+ flags)
&& operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
- only_const));
+ flags));
case STRING_CST:
return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
break;
}
- if (only_const)
+ if (flags & OEP_ONLY_CONST)
return 0;
+/* Define macros to test an operand from arg0 and arg1 for equality and a
+ variant that allows null and views null as being different from any
+ non-null value. In the latter case, if either is null, the both
+ must be; otherwise, do the normal comparison. */
+#define OP_SAME(N) operand_equal_p (TREE_OPERAND (arg0, N), \
+ TREE_OPERAND (arg1, N), flags)
+
+#define OP_SAME_WITH_NULL(N) \
+ ((!TREE_OPERAND (arg0, N) || !TREE_OPERAND (arg1, N)) \
+ ? TREE_OPERAND (arg0, N) == TREE_OPERAND (arg1, N) : OP_SAME (N))
+
switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
{
- case '1':
+ case tcc_unary:
/* Two conversions are equal only if signedness and modes match. */
- if ((TREE_CODE (arg0) == NOP_EXPR || TREE_CODE (arg0) == CONVERT_EXPR)
- && (TREE_UNSIGNED (TREE_TYPE (arg0))
- != TREE_UNSIGNED (TREE_TYPE (arg1))))
- return 0;
+ switch (TREE_CODE (arg0))
+ {
+ CASE_CONVERT:
+ case FIX_TRUNC_EXPR:
+ if (TYPE_UNSIGNED (TREE_TYPE (arg0))
+ != TYPE_UNSIGNED (TREE_TYPE (arg1)))
+ return 0;
+ break;
+ default:
+ break;
+ }
- return operand_equal_p (TREE_OPERAND (arg0, 0),
- TREE_OPERAND (arg1, 0), 0);
+ return OP_SAME (0);
- case '<':
- case '2':
- if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0)
- && operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1),
- 0))
+
+ case tcc_comparison:
+ case tcc_binary:
+ if (OP_SAME (0) && OP_SAME (1))
return 1;
/* For commutative ops, allow the other order. */
- return ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MULT_EXPR
- || TREE_CODE (arg0) == MIN_EXPR || TREE_CODE (arg0) == MAX_EXPR
- || TREE_CODE (arg0) == BIT_IOR_EXPR
- || TREE_CODE (arg0) == BIT_XOR_EXPR
- || TREE_CODE (arg0) == BIT_AND_EXPR
- || TREE_CODE (arg0) == NE_EXPR || TREE_CODE (arg0) == EQ_EXPR)
+ return (commutative_tree_code (TREE_CODE (arg0))
&& operand_equal_p (TREE_OPERAND (arg0, 0),
- TREE_OPERAND (arg1, 1), 0)
+ TREE_OPERAND (arg1, 1), flags)
&& operand_equal_p (TREE_OPERAND (arg0, 1),
- TREE_OPERAND (arg1, 0), 0));
+ TREE_OPERAND (arg1, 0), flags));
- case 'r':
- /* If either of the pointer (or reference) expressions we are dereferencing
- contain a side effect, these cannot be equal. */
+ case tcc_reference:
+ /* If either of the pointer (or reference) expressions we are
+ dereferencing contain a side effect, these cannot be equal. */
if (TREE_SIDE_EFFECTS (arg0)
|| TREE_SIDE_EFFECTS (arg1))
return 0;
switch (TREE_CODE (arg0))
{
case INDIRECT_REF:
- return operand_equal_p (TREE_OPERAND (arg0, 0),
- TREE_OPERAND (arg1, 0), 0);
+ case ALIGN_INDIRECT_REF:
+ case MISALIGNED_INDIRECT_REF:
+ case REALPART_EXPR:
+ case IMAGPART_EXPR:
+ return OP_SAME (0);
- case COMPONENT_REF:
case ARRAY_REF:
case ARRAY_RANGE_REF:
- return (operand_equal_p (TREE_OPERAND (arg0, 0),
- TREE_OPERAND (arg1, 0), 0)
- && operand_equal_p (TREE_OPERAND (arg0, 1),
- TREE_OPERAND (arg1, 1), 0));
+ /* Operands 2 and 3 may be null.
+ Compare the array index by value if it is constant first as we
+ may have different types but same value here. */
+ return (OP_SAME (0)
+ && (tree_int_cst_equal (TREE_OPERAND (arg0, 1),
+ TREE_OPERAND (arg1, 1))
+ || OP_SAME (1))
+ && OP_SAME_WITH_NULL (2)
+ && OP_SAME_WITH_NULL (3));
+
+ case COMPONENT_REF:
+ /* Handle operand 2 the same as for ARRAY_REF. Operand 0
+ may be NULL when we're called to compare MEM_EXPRs. */
+ return OP_SAME_WITH_NULL (0)
+ && OP_SAME (1)
+ && OP_SAME_WITH_NULL (2);
case BIT_FIELD_REF:
+ return OP_SAME (0) && OP_SAME (1) && OP_SAME (2);
+
+ default:
+ return 0;
+ }
+
+ case tcc_expression:
+ switch (TREE_CODE (arg0))
+ {
+ case ADDR_EXPR:
+ case TRUTH_NOT_EXPR:
+ return OP_SAME (0);
+
+ case TRUTH_ANDIF_EXPR:
+ case TRUTH_ORIF_EXPR:
+ return OP_SAME (0) && OP_SAME (1);
+
+ case TRUTH_AND_EXPR:
+ case TRUTH_OR_EXPR:
+ case TRUTH_XOR_EXPR:
+ if (OP_SAME (0) && OP_SAME (1))
+ return 1;
+
+ /* Otherwise take into account this is a commutative operation. */
return (operand_equal_p (TREE_OPERAND (arg0, 0),
- TREE_OPERAND (arg1, 0), 0)
+ TREE_OPERAND (arg1, 1), flags)
&& operand_equal_p (TREE_OPERAND (arg0, 1),
- TREE_OPERAND (arg1, 1), 0)
- && operand_equal_p (TREE_OPERAND (arg0, 2),
- TREE_OPERAND (arg1, 2), 0));
+ TREE_OPERAND (arg1, 0), flags));
+
+ case COND_EXPR:
+ return OP_SAME (0) && OP_SAME (1) && OP_SAME (2);
+
default:
return 0;
}
- case 'e':
- if (TREE_CODE (arg0) == RTL_EXPR)
- return rtx_equal_p (RTL_EXPR_RTL (arg0), RTL_EXPR_RTL (arg1));
- return 0;
+ case tcc_vl_exp:
+ switch (TREE_CODE (arg0))
+ {
+ case CALL_EXPR:
+ /* If the CALL_EXPRs call different functions, then they
+ clearly can not be equal. */
+ if (! operand_equal_p (CALL_EXPR_FN (arg0), CALL_EXPR_FN (arg1),
+ flags))
+ return 0;
+
+ {
+ unsigned int cef = call_expr_flags (arg0);
+ if (flags & OEP_PURE_SAME)
+ cef &= ECF_CONST | ECF_PURE;
+ else
+ cef &= ECF_CONST;
+ if (!cef)
+ return 0;
+ }
+
+ /* Now see if all the arguments are the same. */
+ {
+ const_call_expr_arg_iterator iter0, iter1;
+ const_tree a0, a1;
+ for (a0 = first_const_call_expr_arg (arg0, &iter0),
+ a1 = first_const_call_expr_arg (arg1, &iter1);
+ a0 && a1;
+ a0 = next_const_call_expr_arg (&iter0),
+ a1 = next_const_call_expr_arg (&iter1))
+ if (! operand_equal_p (a0, a1, flags))
+ return 0;
+
+ /* If we get here and both argument lists are exhausted
+ then the CALL_EXPRs are equal. */
+ return ! (a0 || a1);
+ }
+ default:
+ return 0;
+ }
+
+ case tcc_declaration:
+ /* Consider __builtin_sqrt equal to sqrt. */
+ return (TREE_CODE (arg0) == FUNCTION_DECL
+ && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
+ && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
+ && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1));
default:
return 0;
}
+
+#undef OP_SAME
+#undef OP_SAME_WITH_NULL
}
\f
/* Similar to operand_equal_p, but see if ARG0 might have been made by
When in doubt, return 0. */
static int
-operand_equal_for_comparison_p (arg0, arg1, other)
- tree arg0, arg1;
- tree other;
+operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
{
int unsignedp1, unsignedpo;
tree primarg0, primarg1, primother;
/* Make sure shorter operand is extended the right way
to match the longer operand. */
- primarg1 = convert (signed_or_unsigned_type (unsignedp1,
- TREE_TYPE (primarg1)),
- primarg1);
+ primarg1 = fold_convert (signed_or_unsigned_type_for
+ (unsignedp1, TREE_TYPE (primarg1)), primarg1);
- if (operand_equal_p (arg0, convert (type, primarg1), 0))
+ if (operand_equal_p (arg0, fold_convert (type, primarg1), 0))
return 1;
}
/* See if ARG is an expression that is either a comparison or is performing
arithmetic on comparisons. The comparisons must only be comparing
two different values, which will be stored in *CVAL1 and *CVAL2; if
- they are non-zero it means that some operands have already been found.
+ they are nonzero it means that some operands have already been found.
No variables may be used anywhere else in the expression except in the
comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
the expression and save_expr needs to be called with CVAL1 and CVAL2.
If this is true, return 1. Otherwise, return zero. */
static int
-twoval_comparison_p (arg, cval1, cval2, save_p)
- tree arg;
- tree *cval1, *cval2;
- int *save_p;
+twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
{
enum tree_code code = TREE_CODE (arg);
- char class = TREE_CODE_CLASS (code);
+ enum tree_code_class tclass = TREE_CODE_CLASS (code);
- /* We can handle some of the 'e' cases here. */
- if (class == 'e' && code == TRUTH_NOT_EXPR)
- class = '1';
- else if (class == 'e'
+ /* We can handle some of the tcc_expression cases here. */
+ if (tclass == tcc_expression && code == TRUTH_NOT_EXPR)
+ tclass = tcc_unary;
+ else if (tclass == tcc_expression
&& (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
|| code == COMPOUND_EXPR))
- class = '2';
+ tclass = tcc_binary;
- else if (class == 'e' && code == SAVE_EXPR && SAVE_EXPR_RTL (arg) == 0
+ else if (tclass == tcc_expression && code == SAVE_EXPR
&& ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
{
/* If we've already found a CVAL1 or CVAL2, this expression is
if (*cval1 || *cval2)
return 0;
- class = '1';
+ tclass = tcc_unary;
*save_p = 1;
}
- switch (class)
+ switch (tclass)
{
- case '1':
+ case tcc_unary:
return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
- case '2':
+ case tcc_binary:
return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
&& twoval_comparison_p (TREE_OPERAND (arg, 1),
cval1, cval2, save_p));
- case 'c':
+ case tcc_constant:
return 1;
- case 'e':
+ case tcc_expression:
if (code == COND_EXPR)
return (twoval_comparison_p (TREE_OPERAND (arg, 0),
cval1, cval2, save_p)
cval1, cval2, save_p));
return 0;
- case '<':
+ case tcc_comparison:
/* First see if we can handle the first operand, then the second. For
the second operand, we know *CVAL1 can't be zero. It must be that
one side of the comparison is each of the values; test for the
NEW1 and OLD1. */
static tree
-eval_subst (arg, old0, new0, old1, new1)
- tree arg;
- tree old0, new0, old1, new1;
+eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
{
tree type = TREE_TYPE (arg);
enum tree_code code = TREE_CODE (arg);
- char class = TREE_CODE_CLASS (code);
+ enum tree_code_class tclass = TREE_CODE_CLASS (code);
- /* We can handle some of the 'e' cases here. */
- if (class == 'e' && code == TRUTH_NOT_EXPR)
- class = '1';
- else if (class == 'e'
+ /* We can handle some of the tcc_expression cases here. */
+ if (tclass == tcc_expression && code == TRUTH_NOT_EXPR)
+ tclass = tcc_unary;
+ else if (tclass == tcc_expression
&& (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
- class = '2';
+ tclass = tcc_binary;
- switch (class)
+ switch (tclass)
{
- case '1':
- return fold (build1 (code, type,
- eval_subst (TREE_OPERAND (arg, 0),
- old0, new0, old1, new1)));
+ case tcc_unary:
+ return fold_build1 (code, type,
+ eval_subst (TREE_OPERAND (arg, 0),
+ old0, new0, old1, new1));
- case '2':
- return fold (build (code, type,
+ case tcc_binary:
+ return fold_build2 (code, type,
eval_subst (TREE_OPERAND (arg, 0),
old0, new0, old1, new1),
eval_subst (TREE_OPERAND (arg, 1),
- old0, new0, old1, new1)));
+ old0, new0, old1, new1));
- case 'e':
+ case tcc_expression:
switch (code)
{
case SAVE_EXPR:
return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
case COND_EXPR:
- return fold (build (code, type,
+ return fold_build3 (code, type,
eval_subst (TREE_OPERAND (arg, 0),
old0, new0, old1, new1),
eval_subst (TREE_OPERAND (arg, 1),
old0, new0, old1, new1),
eval_subst (TREE_OPERAND (arg, 2),
- old0, new0, old1, new1)));
+ old0, new0, old1, new1));
default:
break;
}
- /* fall through - ??? */
+ /* Fall through - ??? */
- case '<':
+ case tcc_comparison:
{
tree arg0 = TREE_OPERAND (arg, 0);
tree arg1 = TREE_OPERAND (arg, 1);
else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
arg1 = new1;
- return fold (build (code, type, arg0, arg1));
+ return fold_build2 (code, type, arg0, arg1);
}
default:
If OMITTED has side effects, we must evaluate it. Otherwise, just do
the conversion of RESULT to TYPE. */
-static tree
-omit_one_operand (type, result, omitted)
- tree type, result, omitted;
+tree
+omit_one_operand (tree type, tree result, tree omitted)
{
- tree t = convert (type, result);
+ tree t = fold_convert (type, result);
+
+ /* If the resulting operand is an empty statement, just return the omitted
+ statement casted to void. */
+ if (IS_EMPTY_STMT (t) && TREE_SIDE_EFFECTS (omitted))
+ return build1 (NOP_EXPR, void_type_node, fold_ignored_result (omitted));
if (TREE_SIDE_EFFECTS (omitted))
- return build (COMPOUND_EXPR, type, omitted, t);
+ return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
return non_lvalue (t);
}
/* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
static tree
-pedantic_omit_one_operand (type, result, omitted)
- tree type, result, omitted;
+pedantic_omit_one_operand (tree type, tree result, tree omitted)
{
- tree t = convert (type, result);
+ tree t = fold_convert (type, result);
+
+ /* If the resulting operand is an empty statement, just return the omitted
+ statement casted to void. */
+ if (IS_EMPTY_STMT (t) && TREE_SIDE_EFFECTS (omitted))
+ return build1 (NOP_EXPR, void_type_node, fold_ignored_result (omitted));
if (TREE_SIDE_EFFECTS (omitted))
- return build (COMPOUND_EXPR, type, omitted, t);
+ return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
return pedantic_non_lvalue (t);
}
+
+/* Return a tree for the case when the result of an expression is RESULT
+ converted to TYPE and OMITTED1 and OMITTED2 were previously operands
+ of the expression but are now not needed.
+
+ If OMITTED1 or OMITTED2 has side effects, they must be evaluated.
+ If both OMITTED1 and OMITTED2 have side effects, OMITTED1 is
+ evaluated before OMITTED2. Otherwise, if neither has side effects,
+ just do the conversion of RESULT to TYPE. */
+
+tree
+omit_two_operands (tree type, tree result, tree omitted1, tree omitted2)
+{
+ tree t = fold_convert (type, result);
+
+ if (TREE_SIDE_EFFECTS (omitted2))
+ t = build2 (COMPOUND_EXPR, type, omitted2, t);
+ if (TREE_SIDE_EFFECTS (omitted1))
+ t = build2 (COMPOUND_EXPR, type, omitted1, t);
+
+ return TREE_CODE (t) != COMPOUND_EXPR ? non_lvalue (t) : t;
+}
+
\f
/* Return a simplified tree node for the truth-negation of ARG. This
never alters ARG itself. We assume that ARG is an operation that
- returns a truth value (0 or 1). */
+ returns a truth value (0 or 1).
+
+ FIXME: one would think we would fold the result, but it causes
+ problems with the dominator optimizer. */
tree
-invert_truthvalue (arg)
- tree arg;
+fold_truth_not_expr (tree arg)
{
tree type = TREE_TYPE (arg);
enum tree_code code = TREE_CODE (arg);
- if (code == ERROR_MARK)
- return arg;
-
/* If this is a comparison, we can simply invert it, except for
floating-point non-equality comparisons, in which case we just
enclose a TRUTH_NOT_EXPR around what we have. */
- if (TREE_CODE_CLASS (code) == '<')
+ if (TREE_CODE_CLASS (code) == tcc_comparison)
{
- if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg, 0)))
- && !flag_unsafe_math_optimizations
- && code != NE_EXPR
- && code != EQ_EXPR)
- return build1 (TRUTH_NOT_EXPR, type, arg);
+ tree op_type = TREE_TYPE (TREE_OPERAND (arg, 0));
+ if (FLOAT_TYPE_P (op_type)
+ && flag_trapping_math
+ && code != ORDERED_EXPR && code != UNORDERED_EXPR
+ && code != NE_EXPR && code != EQ_EXPR)
+ return NULL_TREE;
else
- return build (invert_tree_comparison (code), type,
- TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
+ {
+ code = invert_tree_comparison (code,
+ HONOR_NANS (TYPE_MODE (op_type)));
+ if (code == ERROR_MARK)
+ return NULL_TREE;
+ else
+ return build2 (code, type,
+ TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
+ }
}
switch (code)
{
case INTEGER_CST:
- return convert (type, build_int_2 (integer_zerop (arg), 0));
+ return constant_boolean_node (integer_zerop (arg), type);
case TRUTH_AND_EXPR:
- return build (TRUTH_OR_EXPR, type,
- invert_truthvalue (TREE_OPERAND (arg, 0)),
- invert_truthvalue (TREE_OPERAND (arg, 1)));
+ return build2 (TRUTH_OR_EXPR, type,
+ invert_truthvalue (TREE_OPERAND (arg, 0)),
+ invert_truthvalue (TREE_OPERAND (arg, 1)));
case TRUTH_OR_EXPR:
- return build (TRUTH_AND_EXPR, type,
- invert_truthvalue (TREE_OPERAND (arg, 0)),
- invert_truthvalue (TREE_OPERAND (arg, 1)));
+ return build2 (TRUTH_AND_EXPR, type,
+ invert_truthvalue (TREE_OPERAND (arg, 0)),
+ invert_truthvalue (TREE_OPERAND (arg, 1)));
case TRUTH_XOR_EXPR:
/* Here we can invert either operand. We invert the first operand
negation of the second operand. */
if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
- return build (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
- TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
+ return build2 (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
+ TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
else
- return build (TRUTH_XOR_EXPR, type,
- invert_truthvalue (TREE_OPERAND (arg, 0)),
- TREE_OPERAND (arg, 1));
+ return build2 (TRUTH_XOR_EXPR, type,
+ invert_truthvalue (TREE_OPERAND (arg, 0)),
+ TREE_OPERAND (arg, 1));
case TRUTH_ANDIF_EXPR:
- return build (TRUTH_ORIF_EXPR, type,
- invert_truthvalue (TREE_OPERAND (arg, 0)),
- invert_truthvalue (TREE_OPERAND (arg, 1)));
+ return build2 (TRUTH_ORIF_EXPR, type,
+ invert_truthvalue (TREE_OPERAND (arg, 0)),
+ invert_truthvalue (TREE_OPERAND (arg, 1)));
case TRUTH_ORIF_EXPR:
- return build (TRUTH_ANDIF_EXPR, type,
- invert_truthvalue (TREE_OPERAND (arg, 0)),
- invert_truthvalue (TREE_OPERAND (arg, 1)));
+ return build2 (TRUTH_ANDIF_EXPR, type,
+ invert_truthvalue (TREE_OPERAND (arg, 0)),
+ invert_truthvalue (TREE_OPERAND (arg, 1)));
case TRUTH_NOT_EXPR:
return TREE_OPERAND (arg, 0);
case COND_EXPR:
- return build (COND_EXPR, type, TREE_OPERAND (arg, 0),
- invert_truthvalue (TREE_OPERAND (arg, 1)),
- invert_truthvalue (TREE_OPERAND (arg, 2)));
+ {
+ tree arg1 = TREE_OPERAND (arg, 1);
+ tree arg2 = TREE_OPERAND (arg, 2);
+ /* A COND_EXPR may have a throw as one operand, which
+ then has void type. Just leave void operands
+ as they are. */
+ return build3 (COND_EXPR, type, TREE_OPERAND (arg, 0),
+ VOID_TYPE_P (TREE_TYPE (arg1))
+ ? arg1 : invert_truthvalue (arg1),
+ VOID_TYPE_P (TREE_TYPE (arg2))
+ ? arg2 : invert_truthvalue (arg2));
+ }
case COMPOUND_EXPR:
- return build (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
- invert_truthvalue (TREE_OPERAND (arg, 1)));
-
- case WITH_RECORD_EXPR:
- return build (WITH_RECORD_EXPR, type,
- invert_truthvalue (TREE_OPERAND (arg, 0)),
- TREE_OPERAND (arg, 1));
+ return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
+ invert_truthvalue (TREE_OPERAND (arg, 1)));
case NON_LVALUE_EXPR:
return invert_truthvalue (TREE_OPERAND (arg, 0));
case NOP_EXPR:
+ if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
+ return build1 (TRUTH_NOT_EXPR, type, arg);
+
case CONVERT_EXPR:
case FLOAT_EXPR:
return build1 (TREE_CODE (arg), type,
case BIT_AND_EXPR:
if (!integer_onep (TREE_OPERAND (arg, 1)))
break;
- return build (EQ_EXPR, type, arg, convert (type, integer_zero_node));
+ return build2 (EQ_EXPR, type, arg,
+ build_int_cst (type, 0));
case SAVE_EXPR:
return build1 (TRUTH_NOT_EXPR, type, arg);
default:
break;
}
- if (TREE_CODE (TREE_TYPE (arg)) != BOOLEAN_TYPE)
- abort ();
- return build1 (TRUTH_NOT_EXPR, type, arg);
+
+ return NULL_TREE;
+}
+
+/* Return a simplified tree node for the truth-negation of ARG. This
+ never alters ARG itself. We assume that ARG is an operation that
+ returns a truth value (0 or 1).
+
+ FIXME: one would think we would fold the result, but it causes
+ problems with the dominator optimizer. */
+
+tree
+invert_truthvalue (tree arg)
+{
+ tree tem;
+
+ if (TREE_CODE (arg) == ERROR_MARK)
+ return arg;
+
+ tem = fold_truth_not_expr (arg);
+ if (!tem)
+ tem = build1 (TRUTH_NOT_EXPR, TREE_TYPE (arg), arg);
+
+ return tem;
}
/* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
operands are another bit-wise operation with a common input. If so,
distribute the bit operations to save an operation and possibly two if
constants are involved. For example, convert
- (A | B) & (A | C) into A | (B & C)
+ (A | B) & (A | C) into A | (B & C)
Further simplification will occur if B and C are constants.
If this optimization cannot be done, 0 will be returned. */
static tree
-distribute_bit_expr (code, type, arg0, arg1)
- enum tree_code code;
- tree type;
- tree arg0, arg1;
+distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
{
tree common;
tree left, right;
else
return 0;
- return fold (build (TREE_CODE (arg0), type, common,
- fold (build (code, type, left, right))));
+ common = fold_convert (type, common);
+ left = fold_convert (type, left);
+ right = fold_convert (type, right);
+ return fold_build2 (TREE_CODE (arg0), type, common,
+ fold_build2 (code, type, left, right));
+}
+
+/* Knowing that ARG0 and ARG1 are both RDIV_EXPRs, simplify a binary operation
+ with code CODE. This optimization is unsafe. */
+static tree
+distribute_real_division (enum tree_code code, tree type, tree arg0, tree arg1)
+{
+ bool mul0 = TREE_CODE (arg0) == MULT_EXPR;
+ bool mul1 = TREE_CODE (arg1) == MULT_EXPR;
+
+ /* (A / C) +- (B / C) -> (A +- B) / C. */
+ if (mul0 == mul1
+ && operand_equal_p (TREE_OPERAND (arg0, 1),
+ TREE_OPERAND (arg1, 1), 0))
+ return fold_build2 (mul0 ? MULT_EXPR : RDIV_EXPR, type,
+ fold_build2 (code, type,
+ TREE_OPERAND (arg0, 0),
+ TREE_OPERAND (arg1, 0)),
+ TREE_OPERAND (arg0, 1));
+
+ /* (A / C1) +- (A / C2) -> A * (1 / C1 +- 1 / C2). */
+ if (operand_equal_p (TREE_OPERAND (arg0, 0),
+ TREE_OPERAND (arg1, 0), 0)
+ && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
+ && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
+ {
+ REAL_VALUE_TYPE r0, r1;
+ r0 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
+ r1 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
+ if (!mul0)
+ real_arithmetic (&r0, RDIV_EXPR, &dconst1, &r0);
+ if (!mul1)
+ real_arithmetic (&r1, RDIV_EXPR, &dconst1, &r1);
+ real_arithmetic (&r0, code, &r0, &r1);
+ return fold_build2 (MULT_EXPR, type,
+ TREE_OPERAND (arg0, 0),
+ build_real (type, r0));
+ }
+
+ return NULL_TREE;
}
\f
/* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
- starting at BITPOS. The field is unsigned if UNSIGNEDP is non-zero. */
+ starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
static tree
-make_bit_field_ref (inner, type, bitsize, bitpos, unsignedp)
- tree inner;
- tree type;
- int bitsize, bitpos;
- int unsignedp;
+make_bit_field_ref (tree inner, tree type, HOST_WIDE_INT bitsize,
+ HOST_WIDE_INT bitpos, int unsignedp)
{
- tree result = build (BIT_FIELD_REF, type, inner,
- size_int (bitsize), bitsize_int (bitpos));
+ tree result, bftype;
+
+ if (bitpos == 0)
+ {
+ tree size = TYPE_SIZE (TREE_TYPE (inner));
+ if ((INTEGRAL_TYPE_P (TREE_TYPE (inner))
+ || POINTER_TYPE_P (TREE_TYPE (inner)))
+ && host_integerp (size, 0)
+ && tree_low_cst (size, 0) == bitsize)
+ return fold_convert (type, inner);
+ }
- TREE_UNSIGNED (result) = unsignedp;
+ bftype = type;
+ if (TYPE_PRECISION (bftype) != bitsize
+ || TYPE_UNSIGNED (bftype) == !unsignedp)
+ bftype = build_nonstandard_integer_type (bitsize, 0);
+
+ result = build3 (BIT_FIELD_REF, bftype, inner,
+ size_int (bitsize), bitsize_int (bitpos));
+
+ if (bftype != type)
+ result = fold_convert (type, result);
return result;
}
tree. Otherwise we return zero. */
static tree
-optimize_bit_field_compare (code, compare_type, lhs, rhs)
- enum tree_code code;
- tree compare_type;
- tree lhs, rhs;
+optimize_bit_field_compare (enum tree_code code, tree compare_type,
+ tree lhs, tree rhs)
{
HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
tree type = TREE_TYPE (lhs);
do anything if the inner expression is a PLACEHOLDER_EXPR since we
then will no longer be able to replace it. */
linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
- &lunsignedp, &lvolatilep);
+ &lunsignedp, &lvolatilep, false);
if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
|| offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
return 0;
/* If this is not a constant, we can only do something if bit positions,
sizes, and signedness are the same. */
rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
- &runsignedp, &rvolatilep);
+ &runsignedp, &rvolatilep, false);
if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
|| lunsignedp != runsignedp || offset != 0
/* Set signed and unsigned types of the precision of this mode for the
shifts below. */
- signed_type = type_for_mode (nmode, 0);
- unsigned_type = type_for_mode (nmode, 1);
+ signed_type = lang_hooks.types.type_for_mode (nmode, 0);
+ unsigned_type = lang_hooks.types.type_for_mode (nmode, 1);
/* Compute the bit position and size for the new reference and our offset
within it. If the new reference is the same size as the original, we
lbitpos = nbitsize - lbitsize - lbitpos;
/* Make the mask to be used against the extracted field. */
- mask = build_int_2 (~0, ~0);
- TREE_TYPE (mask) = unsigned_type;
- force_fit_type (mask, 0);
- mask = convert (unsigned_type, mask);
+ mask = build_int_cst_type (unsigned_type, -1);
mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
mask = const_binop (RSHIFT_EXPR, mask,
size_int (nbitsize - lbitsize - lbitpos), 0);
if (! const_p)
/* If not comparing with constant, just rework the comparison
and return. */
- return build (code, compare_type,
- build (BIT_AND_EXPR, unsigned_type,
- make_bit_field_ref (linner, unsigned_type,
- nbitsize, nbitpos, 1),
- mask),
- build (BIT_AND_EXPR, unsigned_type,
- make_bit_field_ref (rinner, unsigned_type,
- nbitsize, nbitpos, 1),
- mask));
+ return fold_build2 (code, compare_type,
+ fold_build2 (BIT_AND_EXPR, unsigned_type,
+ make_bit_field_ref (linner,
+ unsigned_type,
+ nbitsize, nbitpos,
+ 1),
+ mask),
+ fold_build2 (BIT_AND_EXPR, unsigned_type,
+ make_bit_field_ref (rinner,
+ unsigned_type,
+ nbitsize, nbitpos,
+ 1),
+ mask));
/* Otherwise, we are handling the constant case. See if the constant is too
big for the field. Warn and return a tree of for 0 (false) if so. We do
if (lunsignedp)
{
if (! integer_zerop (const_binop (RSHIFT_EXPR,
- convert (unsigned_type, rhs),
+ fold_convert (unsigned_type, rhs),
size_int (lbitsize), 0)))
{
- warning ("comparison is always %d due to width of bit-field",
+ warning (0, "comparison is always %d due to width of bit-field",
code == NE_EXPR);
- return convert (compare_type,
- (code == NE_EXPR
- ? integer_one_node : integer_zero_node));
+ return constant_boolean_node (code == NE_EXPR, compare_type);
}
}
else
{
- tree tem = const_binop (RSHIFT_EXPR, convert (signed_type, rhs),
+ tree tem = const_binop (RSHIFT_EXPR, fold_convert (signed_type, rhs),
size_int (lbitsize - 1), 0);
if (! integer_zerop (tem) && ! integer_all_onesp (tem))
{
- warning ("comparison is always %d due to width of bit-field",
+ warning (0, "comparison is always %d due to width of bit-field",
code == NE_EXPR);
- return convert (compare_type,
- (code == NE_EXPR
- ? integer_one_node : integer_zero_node));
+ return constant_boolean_node (code == NE_EXPR, compare_type);
}
}
if (lbitsize == 1 && ! integer_zerop (rhs))
{
code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
- rhs = convert (type, integer_zero_node);
+ rhs = build_int_cst (type, 0);
}
/* Make a new bitfield reference, shift the constant over the
TREE_THIS_VOLATILE (lhs) = 1;
}
- rhs = fold (const_binop (BIT_AND_EXPR,
- const_binop (LSHIFT_EXPR,
- convert (unsigned_type, rhs),
- size_int (lbitpos), 0),
- mask, 0));
+ rhs = const_binop (BIT_AND_EXPR,
+ const_binop (LSHIFT_EXPR,
+ fold_convert (unsigned_type, rhs),
+ size_int (lbitpos), 0),
+ mask, 0);
- return build (code, compare_type,
- build (BIT_AND_EXPR, unsigned_type, lhs, mask),
- rhs);
+ return build2 (code, compare_type,
+ build2 (BIT_AND_EXPR, unsigned_type, lhs, mask),
+ rhs);
}
\f
/* Subroutine for fold_truthop: decode a field reference.
do anything with. */
static tree
-decode_field_reference (exp, pbitsize, pbitpos, pmode, punsignedp,
- pvolatilep, pmask, pand_mask)
- tree exp;
- HOST_WIDE_INT *pbitsize, *pbitpos;
- enum machine_mode *pmode;
- int *punsignedp, *pvolatilep;
- tree *pmask;
- tree *pand_mask;
+decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize,
+ HOST_WIDE_INT *pbitpos, enum machine_mode *pmode,
+ int *punsignedp, int *pvolatilep,
+ tree *pmask, tree *pand_mask)
{
+ tree outer_type = 0;
tree and_mask = 0;
tree mask, inner, offset;
tree unsigned_type;
if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
return 0;
+ /* We are interested in the bare arrangement of bits, so strip everything
+ that doesn't affect the machine mode. However, record the type of the
+ outermost expression if it may matter below. */
+ if (CONVERT_EXPR_P (exp)
+ || TREE_CODE (exp) == NON_LVALUE_EXPR)
+ outer_type = TREE_TYPE (exp);
STRIP_NOPS (exp);
if (TREE_CODE (exp) == BIT_AND_EXPR)
}
inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
- punsignedp, pvolatilep);
+ punsignedp, pvolatilep, false);
if ((inner == exp && and_mask == 0)
|| *pbitsize < 0 || offset != 0
|| TREE_CODE (inner) == PLACEHOLDER_EXPR)
return 0;
+ /* If the number of bits in the reference is the same as the bitsize of
+ the outer type, then the outer type gives the signedness. Otherwise
+ (in case of a small bitfield) the signedness is unchanged. */
+ if (outer_type && *pbitsize == TYPE_PRECISION (outer_type))
+ *punsignedp = TYPE_UNSIGNED (outer_type);
+
/* Compute the mask to access the bitfield. */
- unsigned_type = type_for_size (*pbitsize, 1);
+ unsigned_type = lang_hooks.types.type_for_size (*pbitsize, 1);
precision = TYPE_PRECISION (unsigned_type);
- mask = build_int_2 (~0, ~0);
- TREE_TYPE (mask) = unsigned_type;
- force_fit_type (mask, 0);
+ mask = build_int_cst_type (unsigned_type, -1);
+
mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
/* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
if (and_mask != 0)
- mask = fold (build (BIT_AND_EXPR, unsigned_type,
- convert (unsigned_type, and_mask), mask));
+ mask = fold_build2 (BIT_AND_EXPR, unsigned_type,
+ fold_convert (unsigned_type, and_mask), mask);
*pmask = mask;
*pand_mask = and_mask;
return inner;
}
-/* Return non-zero if MASK represents a mask of SIZE ones in the low-order
+/* Return nonzero if MASK represents a mask of SIZE ones in the low-order
bit positions. */
static int
-all_ones_mask_p (mask, size)
- tree mask;
- int size;
+all_ones_mask_p (const_tree mask, int size)
{
tree type = TREE_TYPE (mask);
unsigned int precision = TYPE_PRECISION (type);
tree tmask;
- tmask = build_int_2 (~0, ~0);
- TREE_TYPE (tmask) = signed_type (type);
- force_fit_type (tmask, 0);
+ tmask = build_int_cst_type (signed_type_for (type), -1);
+
return
tree_int_cst_equal (mask,
const_binop (RSHIFT_EXPR,
size_int (precision - size), 0));
}
+/* Subroutine for fold: determine if VAL is the INTEGER_CONST that
+ represents the sign bit of EXP's type. If EXP represents a sign
+ or zero extension, also test VAL against the unextended type.
+ The return value is the (sub)expression whose sign bit is VAL,
+ or NULL_TREE otherwise. */
+
+static tree
+sign_bit_p (tree exp, const_tree val)
+{
+ unsigned HOST_WIDE_INT mask_lo, lo;
+ HOST_WIDE_INT mask_hi, hi;
+ int width;
+ tree t;
+
+ /* Tree EXP must have an integral type. */
+ t = TREE_TYPE (exp);
+ if (! INTEGRAL_TYPE_P (t))
+ return NULL_TREE;
+
+ /* Tree VAL must be an integer constant. */
+ if (TREE_CODE (val) != INTEGER_CST
+ || TREE_OVERFLOW (val))
+ return NULL_TREE;
+
+ width = TYPE_PRECISION (t);
+ if (width > HOST_BITS_PER_WIDE_INT)
+ {
+ hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
+ lo = 0;
+
+ mask_hi = ((unsigned HOST_WIDE_INT) -1
+ >> (2 * HOST_BITS_PER_WIDE_INT - width));
+ mask_lo = -1;
+ }
+ else
+ {
+ hi = 0;
+ lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
+
+ mask_hi = 0;
+ mask_lo = ((unsigned HOST_WIDE_INT) -1
+ >> (HOST_BITS_PER_WIDE_INT - width));
+ }
+
+ /* We mask off those bits beyond TREE_TYPE (exp) so that we can
+ treat VAL as if it were unsigned. */
+ if ((TREE_INT_CST_HIGH (val) & mask_hi) == hi
+ && (TREE_INT_CST_LOW (val) & mask_lo) == lo)
+ return exp;
+
+ /* Handle extension from a narrower type. */
+ if (TREE_CODE (exp) == NOP_EXPR
+ && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
+ return sign_bit_p (TREE_OPERAND (exp, 0), val);
+
+ return NULL_TREE;
+}
+
/* Subroutine for fold_truthop: determine if an operand is simple enough
to be evaluated unconditionally. */
static int
-simple_operand_p (exp)
- tree exp;
+simple_operand_p (const_tree exp)
{
/* Strip any conversions that don't change the machine mode. */
- while ((TREE_CODE (exp) == NOP_EXPR
- || TREE_CODE (exp) == CONVERT_EXPR)
- && (TYPE_MODE (TREE_TYPE (exp))
- == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)))))
- exp = TREE_OPERAND (exp, 0);
+ STRIP_NOPS (exp);
- return (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c'
+ return (CONSTANT_CLASS_P (exp)
+ || TREE_CODE (exp) == SSA_NAME
|| (DECL_P (exp)
&& ! TREE_ADDRESSABLE (exp)
&& ! TREE_THIS_VOLATILE (exp)
try to change a logical combination of comparisons into a range test.
For example, both
- X == 2 || X == 3 || X == 4 || X == 5
+ X == 2 || X == 3 || X == 4 || X == 5
and
- X >= 2 && X <= 5
+ X >= 2 && X <= 5
are converted to
(unsigned) (X - 2) <= 3
type if both are specified. */
static tree
-range_binop (code, type, arg0, upper0_p, arg1, upper1_p)
- enum tree_code code;
- tree type;
- tree arg0, arg1;
- int upper0_p, upper1_p;
+range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
+ tree arg1, int upper1_p)
{
tree tem;
int result;
if (arg0 != 0 && arg1 != 0)
{
- tem = fold (build (code, type != 0 ? type : TREE_TYPE (arg0),
- arg0, convert (TREE_TYPE (arg0), arg1)));
+ tem = fold_build2 (code, type != 0 ? type : TREE_TYPE (arg0),
+ arg0, fold_convert (TREE_TYPE (arg0), arg1));
STRIP_NOPS (tem);
return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
}
- if (TREE_CODE_CLASS (code) != '<')
+ if (TREE_CODE_CLASS (code) != tcc_comparison)
return 0;
/* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
result = sgn0 >= sgn1;
break;
default:
- abort ();
+ gcc_unreachable ();
}
- return convert (type, result ? integer_one_node : integer_zero_node);
+ return constant_boolean_node (result, type);
}
\f
/* Given EXP, a logical expression, set the range it is testing into
variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
- actually being tested. *PLOW and *PHIGH will be made of the same type
- as the returned expression. If EXP is not a comparison, we will most
- likely not be returning a useful value and range. */
+ actually being tested. *PLOW and *PHIGH will be made of the same
+ type as the returned expression. If EXP is not a comparison, we
+ will most likely not be returning a useful value and range. Set
+ *STRICT_OVERFLOW_P to true if the return value is only valid
+ because signed overflow is undefined; otherwise, do not change
+ *STRICT_OVERFLOW_P. */
static tree
-make_range (exp, pin_p, plow, phigh)
- tree exp;
- int *pin_p;
- tree *plow, *phigh;
+make_range (tree exp, int *pin_p, tree *plow, tree *phigh,
+ bool *strict_overflow_p)
{
enum tree_code code;
- tree arg0 = NULL_TREE, arg1 = NULL_TREE, type = NULL_TREE;
- tree orig_type = NULL_TREE;
+ tree arg0 = NULL_TREE, arg1 = NULL_TREE;
+ tree exp_type = NULL_TREE, arg0_type = NULL_TREE;
int in_p, n_in_p;
tree low, high, n_low, n_high;
the outer loop when we've changed something; otherwise we "break"
the switch, which will "break" the while. */
- in_p = 0, low = high = convert (TREE_TYPE (exp), integer_zero_node);
+ in_p = 0;
+ low = high = build_int_cst (TREE_TYPE (exp), 0);
while (1)
{
code = TREE_CODE (exp);
+ exp_type = TREE_TYPE (exp);
if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
{
- arg0 = TREE_OPERAND (exp, 0);
- if (TREE_CODE_CLASS (code) == '<'
- || TREE_CODE_CLASS (code) == '1'
- || TREE_CODE_CLASS (code) == '2')
- type = TREE_TYPE (arg0);
- if (TREE_CODE_CLASS (code) == '2'
- || TREE_CODE_CLASS (code) == '<'
- || (TREE_CODE_CLASS (code) == 'e'
- && TREE_CODE_LENGTH (code) > 1))
+ if (TREE_OPERAND_LENGTH (exp) > 0)
+ arg0 = TREE_OPERAND (exp, 0);
+ if (TREE_CODE_CLASS (code) == tcc_comparison
+ || TREE_CODE_CLASS (code) == tcc_unary
+ || TREE_CODE_CLASS (code) == tcc_binary)
+ arg0_type = TREE_TYPE (arg0);
+ if (TREE_CODE_CLASS (code) == tcc_binary
+ || TREE_CODE_CLASS (code) == tcc_comparison
+ || (TREE_CODE_CLASS (code) == tcc_expression
+ && TREE_OPERAND_LENGTH (exp) > 1))
arg1 = TREE_OPERAND (exp, 1);
}
- /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
- lose a cast by accident. */
- if (type != NULL_TREE && orig_type == NULL_TREE)
- orig_type = type;
-
switch (code)
{
case TRUTH_NOT_EXPR:
in_p = ! in_p, low = 0, high = arg1;
break;
default:
- abort ();
+ gcc_unreachable ();
}
- exp = arg0;
-
/* If this is an unsigned comparison, we also know that EXP is
greater than or equal to zero. We base the range tests we make
on that fact, so we record it here so we can parse existing
- range tests. */
- if (TREE_UNSIGNED (type) && (low == 0 || high == 0))
+ range tests. We test arg0_type since often the return type
+ of, e.g. EQ_EXPR, is boolean. */
+ if (TYPE_UNSIGNED (arg0_type) && (low == 0 || high == 0))
{
- if (! merge_ranges (&n_in_p, &n_low, &n_high, in_p, low, high,
- 1, convert (type, integer_zero_node),
+ if (! merge_ranges (&n_in_p, &n_low, &n_high,
+ in_p, low, high, 1,
+ build_int_cst (arg0_type, 0),
NULL_TREE))
break;
in_p = n_in_p, low = n_low, high = n_high;
- /* If the high bound is missing, but we
- have a low bound, reverse the range so
- it goes from zero to the low bound minus 1. */
- if (high == 0 && low)
+ /* If the high bound is missing, but we have a nonzero low
+ bound, reverse the range so it goes from zero to the low bound
+ minus 1. */
+ if (high == 0 && low && ! integer_zerop (low))
{
in_p = ! in_p;
high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
integer_one_node, 0);
- low = convert (type, integer_zero_node);
+ low = build_int_cst (arg0_type, 0);
}
}
+
+ exp = arg0;
continue;
case NEGATE_EXPR:
/* (-x) IN [a,b] -> x in [-b, -a] */
- n_low = range_binop (MINUS_EXPR, type,
- convert (type, integer_zero_node), 0, high, 1);
- n_high = range_binop (MINUS_EXPR, type,
- convert (type, integer_zero_node), 0, low, 0);
+ n_low = range_binop (MINUS_EXPR, exp_type,
+ build_int_cst (exp_type, 0),
+ 0, high, 1);
+ n_high = range_binop (MINUS_EXPR, exp_type,
+ build_int_cst (exp_type, 0),
+ 0, low, 0);
low = n_low, high = n_high;
exp = arg0;
continue;
case BIT_NOT_EXPR:
/* ~ X -> -X - 1 */
- exp = build (MINUS_EXPR, type, negate_expr (arg0),
- convert (type, integer_one_node));
+ exp = build2 (MINUS_EXPR, exp_type, negate_expr (arg0),
+ build_int_cst (exp_type, 1));
continue;
case PLUS_EXPR: case MINUS_EXPR:
if (TREE_CODE (arg1) != INTEGER_CST)
break;
+ /* If flag_wrapv and ARG0_TYPE is signed, then we cannot
+ move a constant to the other side. */
+ if (!TYPE_UNSIGNED (arg0_type)
+ && !TYPE_OVERFLOW_UNDEFINED (arg0_type))
+ break;
+
/* If EXP is signed, any overflow in the computation is undefined,
so we don't worry about it so long as our computations on
the bounds don't overflow. For unsigned, overflow is defined
and this is exactly the right thing. */
n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
- type, low, 0, arg1, 0);
+ arg0_type, low, 0, arg1, 0);
n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
- type, high, 1, arg1, 0);
+ arg0_type, high, 1, arg1, 0);
if ((n_low != 0 && TREE_OVERFLOW (n_low))
|| (n_high != 0 && TREE_OVERFLOW (n_high)))
break;
+ if (TYPE_OVERFLOW_UNDEFINED (arg0_type))
+ *strict_overflow_p = true;
+
/* Check for an unsigned range which has wrapped around the maximum
value thus making n_high < n_low, and normalize it. */
if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
{
- low = range_binop (PLUS_EXPR, type, n_high, 0,
+ low = range_binop (PLUS_EXPR, arg0_type, n_high, 0,
integer_one_node, 0);
- high = range_binop (MINUS_EXPR, type, n_low, 0,
+ high = range_binop (MINUS_EXPR, arg0_type, n_low, 0,
integer_one_node, 0);
/* If the range is of the form +/- [ x+1, x ], we won't
exp = arg0;
continue;
- case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
- if (TYPE_PRECISION (type) > TYPE_PRECISION (orig_type))
+ CASE_CONVERT: case NON_LVALUE_EXPR:
+ if (TYPE_PRECISION (arg0_type) > TYPE_PRECISION (exp_type))
break;
- if (! INTEGRAL_TYPE_P (type)
- || (low != 0 && ! int_fits_type_p (low, type))
- || (high != 0 && ! int_fits_type_p (high, type)))
+ if (! INTEGRAL_TYPE_P (arg0_type)
+ || (low != 0 && ! int_fits_type_p (low, arg0_type))
+ || (high != 0 && ! int_fits_type_p (high, arg0_type)))
break;
n_low = low, n_high = high;
if (n_low != 0)
- n_low = convert (type, n_low);
+ n_low = fold_convert (arg0_type, n_low);
if (n_high != 0)
- n_high = convert (type, n_high);
+ n_high = fold_convert (arg0_type, n_high);
- /* If we're converting from an unsigned to a signed type,
- we will be doing the comparison as unsigned. The tests above
- have already verified that LOW and HIGH are both positive.
- So we have to make sure that the original unsigned value will
- be interpreted as positive. */
- if (TREE_UNSIGNED (type) && ! TREE_UNSIGNED (TREE_TYPE (exp)))
+ /* If we're converting arg0 from an unsigned type, to exp,
+ a signed type, we will be doing the comparison as unsigned.
+ The tests above have already verified that LOW and HIGH
+ are both positive.
+
+ So we have to ensure that we will handle large unsigned
+ values the same way that the current signed bounds treat
+ negative values. */
+
+ if (!TYPE_UNSIGNED (exp_type) && TYPE_UNSIGNED (arg0_type))
{
- tree equiv_type = type_for_mode (TYPE_MODE (type), 1);
tree high_positive;
+ tree equiv_type;
+ /* For fixed-point modes, we need to pass the saturating flag
+ as the 2nd parameter. */
+ if (ALL_FIXED_POINT_MODE_P (TYPE_MODE (arg0_type)))
+ equiv_type = lang_hooks.types.type_for_mode
+ (TYPE_MODE (arg0_type),
+ TYPE_SATURATING (arg0_type));
+ else
+ equiv_type = lang_hooks.types.type_for_mode
+ (TYPE_MODE (arg0_type), 1);
/* A range without an upper bound is, naturally, unbounded.
Since convert would have cropped a very large value, use
the max value for the destination type. */
high_positive
= TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
- : TYPE_MAX_VALUE (type);
+ : TYPE_MAX_VALUE (arg0_type);
- high_positive = fold (build (RSHIFT_EXPR, type,
- convert (type, high_positive),
- convert (type, integer_one_node)));
+ if (TYPE_PRECISION (exp_type) == TYPE_PRECISION (arg0_type))
+ high_positive = fold_build2 (RSHIFT_EXPR, arg0_type,
+ fold_convert (arg0_type,
+ high_positive),
+ build_int_cst (arg0_type, 1));
/* If the low bound is specified, "and" the range with the
range for which the original unsigned value will be
if (low != 0)
{
if (! merge_ranges (&n_in_p, &n_low, &n_high,
- 1, n_low, n_high,
- 1, convert (type, integer_zero_node),
+ 1, n_low, n_high, 1,
+ fold_convert (arg0_type,
+ integer_zero_node),
high_positive))
break;
/* Otherwise, "or" the range with the range of the input
that will be interpreted as negative. */
if (! merge_ranges (&n_in_p, &n_low, &n_high,
- 0, n_low, n_high,
- 1, convert (type, integer_zero_node),
+ 0, n_low, n_high, 1,
+ fold_convert (arg0_type,
+ integer_zero_node),
high_positive))
break;
\f
/* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
type, TYPE, return an expression to test if EXP is in (or out of, depending
- on IN_P) the range. */
+ on IN_P) the range. Return 0 if the test couldn't be created. */
static tree
-build_range_check (type, exp, in_p, low, high)
- tree type;
- tree exp;
- int in_p;
- tree low, high;
+build_range_check (tree type, tree exp, int in_p, tree low, tree high)
{
tree etype = TREE_TYPE (exp);
- tree utype, value;
+ tree value;
+
+#ifdef HAVE_canonicalize_funcptr_for_compare
+ /* Disable this optimization for function pointer expressions
+ on targets that require function pointer canonicalization. */
+ if (HAVE_canonicalize_funcptr_for_compare
+ && TREE_CODE (etype) == POINTER_TYPE
+ && TREE_CODE (TREE_TYPE (etype)) == FUNCTION_TYPE)
+ return NULL_TREE;
+#endif
+
+ if (! in_p)
+ {
+ value = build_range_check (type, exp, 1, low, high);
+ if (value != 0)
+ return invert_truthvalue (value);
+
+ return 0;
+ }
+
+ if (low == 0 && high == 0)
+ return build_int_cst (type, 1);
+
+ if (low == 0)
+ return fold_build2 (LE_EXPR, type, exp,
+ fold_convert (etype, high));
+
+ if (high == 0)
+ return fold_build2 (GE_EXPR, type, exp,
+ fold_convert (etype, low));
+
+ if (operand_equal_p (low, high, 0))
+ return fold_build2 (EQ_EXPR, type, exp,
+ fold_convert (etype, low));
+
+ if (integer_zerop (low))
+ {
+ if (! TYPE_UNSIGNED (etype))
+ {
+ etype = unsigned_type_for (etype);
+ high = fold_convert (etype, high);
+ exp = fold_convert (etype, exp);
+ }
+ return build_range_check (type, exp, 1, 0, high);
+ }
+
+ /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
+ if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
+ {
+ unsigned HOST_WIDE_INT lo;
+ HOST_WIDE_INT hi;
+ int prec;
+
+ prec = TYPE_PRECISION (etype);
+ if (prec <= HOST_BITS_PER_WIDE_INT)
+ {
+ hi = 0;
+ lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
+ }
+ else
+ {
+ hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
+ lo = (unsigned HOST_WIDE_INT) -1;
+ }
- if (! in_p
- && (0 != (value = build_range_check (type, exp, 1, low, high))))
- return invert_truthvalue (value);
+ if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
+ {
+ if (TYPE_UNSIGNED (etype))
+ {
+ tree signed_etype = signed_type_for (etype);
+ if (TYPE_PRECISION (signed_etype) != TYPE_PRECISION (etype))
+ etype
+ = build_nonstandard_integer_type (TYPE_PRECISION (etype), 0);
+ else
+ etype = signed_etype;
+ exp = fold_convert (etype, exp);
+ }
+ return fold_build2 (GT_EXPR, type, exp,
+ build_int_cst (etype, 0));
+ }
+ }
+
+ /* Optimize (c>=low) && (c<=high) into (c-low>=0) && (c-low<=high-low).
+ This requires wrap-around arithmetics for the type of the expression. */
+ switch (TREE_CODE (etype))
+ {
+ case INTEGER_TYPE:
+ /* There is no requirement that LOW be within the range of ETYPE
+ if the latter is a subtype. It must, however, be within the base
+ type of ETYPE. So be sure we do the subtraction in that type. */
+ if (TREE_TYPE (etype))
+ etype = TREE_TYPE (etype);
+ break;
+
+ case ENUMERAL_TYPE:
+ case BOOLEAN_TYPE:
+ etype = lang_hooks.types.type_for_size (TYPE_PRECISION (etype),
+ TYPE_UNSIGNED (etype));
+ break;
- else if (low == 0 && high == 0)
- return convert (type, integer_one_node);
+ default:
+ break;
+ }
- else if (low == 0)
- return fold (build (LE_EXPR, type, exp, high));
+ /* If we don't have wrap-around arithmetics upfront, try to force it. */
+ if (TREE_CODE (etype) == INTEGER_TYPE
+ && !TYPE_OVERFLOW_WRAPS (etype))
+ {
+ tree utype, minv, maxv;
+
+ /* Check if (unsigned) INT_MAX + 1 == (unsigned) INT_MIN
+ for the type in question, as we rely on this here. */
+ utype = unsigned_type_for (etype);
+ maxv = fold_convert (utype, TYPE_MAX_VALUE (etype));
+ maxv = range_binop (PLUS_EXPR, NULL_TREE, maxv, 1,
+ integer_one_node, 1);
+ minv = fold_convert (utype, TYPE_MIN_VALUE (etype));
+
+ if (integer_zerop (range_binop (NE_EXPR, integer_type_node,
+ minv, 1, maxv, 1)))
+ etype = utype;
+ else
+ return 0;
+ }
- else if (high == 0)
- return fold (build (GE_EXPR, type, exp, low));
+ high = fold_convert (etype, high);
+ low = fold_convert (etype, low);
+ exp = fold_convert (etype, exp);
- else if (operand_equal_p (low, high, 0))
- return fold (build (EQ_EXPR, type, exp, low));
+ value = const_binop (MINUS_EXPR, high, low, 0);
- else if (TREE_UNSIGNED (etype) && integer_zerop (low))
- return build_range_check (type, exp, 1, 0, high);
- else if (integer_zerop (low))
+ if (POINTER_TYPE_P (etype))
{
- utype = unsigned_type (etype);
- return build_range_check (type, convert (utype, exp), 1, 0,
- convert (utype, high));
+ if (value != 0 && !TREE_OVERFLOW (value))
+ {
+ low = fold_convert (sizetype, low);
+ low = fold_build1 (NEGATE_EXPR, sizetype, low);
+ return build_range_check (type,
+ fold_build2 (POINTER_PLUS_EXPR, etype, exp, low),
+ 1, build_int_cst (etype, 0), value);
+ }
+ return 0;
}
- else if (0 != (value = const_binop (MINUS_EXPR, high, low, 0))
- && ! TREE_OVERFLOW (value))
+ if (value != 0 && !TREE_OVERFLOW (value))
return build_range_check (type,
- fold (build (MINUS_EXPR, etype, exp, low)),
- 1, convert (etype, integer_zero_node), value);
- else
- return 0;
+ fold_build2 (MINUS_EXPR, etype, exp, low),
+ 1, build_int_cst (etype, 0), value);
+
+ return 0;
}
\f
-/* Given two ranges, see if we can merge them into one. Return 1 if we
- can, 0 if we can't. Set the output range into the specified parameters. */
+/* Return the predecessor of VAL in its type, handling the infinite case. */
-static int
-merge_ranges (pin_p, plow, phigh, in0_p, low0, high0, in1_p, low1, high1)
- int *pin_p;
- tree *plow, *phigh;
- int in0_p, in1_p;
- tree low0, high0, low1, high1;
+static tree
+range_predecessor (tree val)
{
- int no_overlap;
- int subset;
- int temp;
+ tree type = TREE_TYPE (val);
+
+ if (INTEGRAL_TYPE_P (type)
+ && operand_equal_p (val, TYPE_MIN_VALUE (type), 0))
+ return 0;
+ else
+ return range_binop (MINUS_EXPR, NULL_TREE, val, 0, integer_one_node, 0);
+}
+
+/* Return the successor of VAL in its type, handling the infinite case. */
+
+static tree
+range_successor (tree val)
+{
+ tree type = TREE_TYPE (val);
+
+ if (INTEGRAL_TYPE_P (type)
+ && operand_equal_p (val, TYPE_MAX_VALUE (type), 0))
+ return 0;
+ else
+ return range_binop (PLUS_EXPR, NULL_TREE, val, 0, integer_one_node, 0);
+}
+
+/* Given two ranges, see if we can merge them into one. Return 1 if we
+ can, 0 if we can't. Set the output range into the specified parameters. */
+
+static int
+merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
+ tree high0, int in1_p, tree low1, tree high1)
+{
+ int no_overlap;
+ int subset;
+ int temp;
tree tem;
int in_p;
tree low, high;
/* If they don't overlap, the result is the first range. If they are
equal, the result is false. If the second range is a subset of the
first, and the ranges begin at the same place, we go from just after
- the end of the first range to the end of the second. If the second
+ the end of the second range to the end of the first. If the second
range is not a subset of the first, or if it is a subset and both
ranges end at the same place, the range starts at the start of the
first range and ends just before the second range.
in_p = 0, low = high = 0;
else if (subset && lowequal)
{
- in_p = 1, high = high0;
- low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
- integer_one_node, 0);
+ low = range_successor (high1);
+ high = high0;
+ in_p = 1;
+ if (low == 0)
+ {
+ /* We are in the weird situation where high0 > high1 but
+ high1 has no successor. Punt. */
+ return 0;
+ }
}
else if (! subset || highequal)
{
- in_p = 1, low = low0;
- high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
- integer_one_node, 0);
+ low = low0;
+ high = range_predecessor (low1);
+ in_p = 1;
+ if (high == 0)
+ {
+ /* low0 < low1 but low1 has no predecessor. Punt. */
+ return 0;
+ }
}
else
return 0;
in_p = 0, low = high = 0;
else
{
- in_p = 1, high = high1;
- low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
- integer_one_node, 0);
+ low = range_successor (high0);
+ high = high1;
+ in_p = 1;
+ if (low == 0)
+ {
+ /* high1 > high0 but high0 has no successor. Punt. */
+ return 0;
+ }
}
}
if (no_overlap)
{
if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
- range_binop (PLUS_EXPR, NULL_TREE,
- high0, 1,
- integer_one_node, 1),
+ range_successor (high0),
1, low1, 0)))
in_p = 0, low = low0, high = high1;
else
- return 0;
+ {
+ /* Canonicalize - [min, x] into - [-, x]. */
+ if (low0 && TREE_CODE (low0) == INTEGER_CST)
+ switch (TREE_CODE (TREE_TYPE (low0)))
+ {
+ case ENUMERAL_TYPE:
+ if (TYPE_PRECISION (TREE_TYPE (low0))
+ != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (low0))))
+ break;
+ /* FALLTHROUGH */
+ case INTEGER_TYPE:
+ if (tree_int_cst_equal (low0,
+ TYPE_MIN_VALUE (TREE_TYPE (low0))))
+ low0 = 0;
+ break;
+ case POINTER_TYPE:
+ if (TYPE_UNSIGNED (TREE_TYPE (low0))
+ && integer_zerop (low0))
+ low0 = 0;
+ break;
+ default:
+ break;
+ }
+
+ /* Canonicalize - [x, max] into - [x, -]. */
+ if (high1 && TREE_CODE (high1) == INTEGER_CST)
+ switch (TREE_CODE (TREE_TYPE (high1)))
+ {
+ case ENUMERAL_TYPE:
+ if (TYPE_PRECISION (TREE_TYPE (high1))
+ != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (high1))))
+ break;
+ /* FALLTHROUGH */
+ case INTEGER_TYPE:
+ if (tree_int_cst_equal (high1,
+ TYPE_MAX_VALUE (TREE_TYPE (high1))))
+ high1 = 0;
+ break;
+ case POINTER_TYPE:
+ if (TYPE_UNSIGNED (TREE_TYPE (high1))
+ && integer_zerop (range_binop (PLUS_EXPR, NULL_TREE,
+ high1, 1,
+ integer_one_node, 1)))
+ high1 = 0;
+ break;
+ default:
+ break;
+ }
+
+ /* The ranges might be also adjacent between the maximum and
+ minimum values of the given type. For
+ - [{min,-}, x] and - [y, {max,-}] ranges where x + 1 < y
+ return + [x + 1, y - 1]. */
+ if (low0 == 0 && high1 == 0)
+ {
+ low = range_successor (high0);
+ high = range_predecessor (low1);
+ if (low == 0 || high == 0)
+ return 0;
+
+ in_p = 1;
+ }
+ else
+ return 0;
+ }
}
else if (subset)
in_p = 0, low = low0, high = high0;
return 1;
}
\f
+
+/* Subroutine of fold, looking inside expressions of the form
+ A op B ? A : C, where ARG0, ARG1 and ARG2 are the three operands
+ of the COND_EXPR. This function is being used also to optimize
+ A op B ? C : A, by reversing the comparison first.
+
+ Return a folded expression whose code is not a COND_EXPR
+ anymore, or NULL_TREE if no folding opportunity is found. */
+
+static tree
+fold_cond_expr_with_comparison (tree type, tree arg0, tree arg1, tree arg2)
+{
+ enum tree_code comp_code = TREE_CODE (arg0);
+ tree arg00 = TREE_OPERAND (arg0, 0);
+ tree arg01 = TREE_OPERAND (arg0, 1);
+ tree arg1_type = TREE_TYPE (arg1);
+ tree tem;
+
+ STRIP_NOPS (arg1);
+ STRIP_NOPS (arg2);
+
+ /* If we have A op 0 ? A : -A, consider applying the following
+ transformations:
+
+ A == 0? A : -A same as -A
+ A != 0? A : -A same as A
+ A >= 0? A : -A same as abs (A)
+ A > 0? A : -A same as abs (A)
+ A <= 0? A : -A same as -abs (A)
+ A < 0? A : -A same as -abs (A)
+
+ None of these transformations work for modes with signed
+ zeros. If A is +/-0, the first two transformations will
+ change the sign of the result (from +0 to -0, or vice
+ versa). The last four will fix the sign of the result,
+ even though the original expressions could be positive or
+ negative, depending on the sign of A.
+
+ Note that all these transformations are correct if A is
+ NaN, since the two alternatives (A and -A) are also NaNs. */
+ if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type))
+ && (FLOAT_TYPE_P (TREE_TYPE (arg01))
+ ? real_zerop (arg01)
+ : integer_zerop (arg01))
+ && ((TREE_CODE (arg2) == NEGATE_EXPR
+ && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
+ /* In the case that A is of the form X-Y, '-A' (arg2) may
+ have already been folded to Y-X, check for that. */
+ || (TREE_CODE (arg1) == MINUS_EXPR
+ && TREE_CODE (arg2) == MINUS_EXPR
+ && operand_equal_p (TREE_OPERAND (arg1, 0),
+ TREE_OPERAND (arg2, 1), 0)
+ && operand_equal_p (TREE_OPERAND (arg1, 1),
+ TREE_OPERAND (arg2, 0), 0))))
+ switch (comp_code)
+ {
+ case EQ_EXPR:
+ case UNEQ_EXPR:
+ tem = fold_convert (arg1_type, arg1);
+ return pedantic_non_lvalue (fold_convert (type, negate_expr (tem)));
+ case NE_EXPR:
+ case LTGT_EXPR:
+ return pedantic_non_lvalue (fold_convert (type, arg1));
+ case UNGE_EXPR:
+ case UNGT_EXPR:
+ if (flag_trapping_math)
+ break;
+ /* Fall through. */
+ case GE_EXPR:
+ case GT_EXPR:
+ if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
+ arg1 = fold_convert (signed_type_for
+ (TREE_TYPE (arg1)), arg1);
+ tem = fold_build1 (ABS_EXPR, TREE_TYPE (arg1), arg1);
+ return pedantic_non_lvalue (fold_convert (type, tem));
+ case UNLE_EXPR:
+ case UNLT_EXPR:
+ if (flag_trapping_math)
+ break;
+ case LE_EXPR:
+ case LT_EXPR:
+ if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
+ arg1 = fold_convert (signed_type_for
+ (TREE_TYPE (arg1)), arg1);
+ tem = fold_build1 (ABS_EXPR, TREE_TYPE (arg1), arg1);
+ return negate_expr (fold_convert (type, tem));
+ default:
+ gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
+ break;
+ }
+
+ /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
+ A == 0 ? A : 0 is always 0 unless A is -0. Note that
+ both transformations are correct when A is NaN: A != 0
+ is then true, and A == 0 is false. */
+
+ if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type))
+ && integer_zerop (arg01) && integer_zerop (arg2))
+ {
+ if (comp_code == NE_EXPR)
+ return pedantic_non_lvalue (fold_convert (type, arg1));
+ else if (comp_code == EQ_EXPR)
+ return build_int_cst (type, 0);
+ }
+
+ /* Try some transformations of A op B ? A : B.
+
+ A == B? A : B same as B
+ A != B? A : B same as A
+ A >= B? A : B same as max (A, B)
+ A > B? A : B same as max (B, A)
+ A <= B? A : B same as min (A, B)
+ A < B? A : B same as min (B, A)
+
+ As above, these transformations don't work in the presence
+ of signed zeros. For example, if A and B are zeros of
+ opposite sign, the first two transformations will change
+ the sign of the result. In the last four, the original
+ expressions give different results for (A=+0, B=-0) and
+ (A=-0, B=+0), but the transformed expressions do not.
+
+ The first two transformations are correct if either A or B
+ is a NaN. In the first transformation, the condition will
+ be false, and B will indeed be chosen. In the case of the
+ second transformation, the condition A != B will be true,
+ and A will be chosen.
+
+ The conversions to max() and min() are not correct if B is
+ a number and A is not. The conditions in the original
+ expressions will be false, so all four give B. The min()
+ and max() versions would give a NaN instead. */
+ if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type))
+ && operand_equal_for_comparison_p (arg01, arg2, arg00)
+ /* Avoid these transformations if the COND_EXPR may be used
+ as an lvalue in the C++ front-end. PR c++/19199. */
+ && (in_gimple_form
+ || (strcmp (lang_hooks.name, "GNU C++") != 0
+ && strcmp (lang_hooks.name, "GNU Objective-C++") != 0)
+ || ! maybe_lvalue_p (arg1)
+ || ! maybe_lvalue_p (arg2)))
+ {
+ tree comp_op0 = arg00;
+ tree comp_op1 = arg01;
+ tree comp_type = TREE_TYPE (comp_op0);
+
+ /* Avoid adding NOP_EXPRs in case this is an lvalue. */
+ if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
+ {
+ comp_type = type;
+ comp_op0 = arg1;
+ comp_op1 = arg2;
+ }
+
+ switch (comp_code)
+ {
+ case EQ_EXPR:
+ return pedantic_non_lvalue (fold_convert (type, arg2));
+ case NE_EXPR:
+ return pedantic_non_lvalue (fold_convert (type, arg1));
+ case LE_EXPR:
+ case LT_EXPR:
+ case UNLE_EXPR:
+ case UNLT_EXPR:
+ /* In C++ a ?: expression can be an lvalue, so put the
+ operand which will be used if they are equal first
+ so that we can convert this back to the
+ corresponding COND_EXPR. */
+ if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
+ {
+ comp_op0 = fold_convert (comp_type, comp_op0);
+ comp_op1 = fold_convert (comp_type, comp_op1);
+ tem = (comp_code == LE_EXPR || comp_code == UNLE_EXPR)
+ ? fold_build2 (MIN_EXPR, comp_type, comp_op0, comp_op1)
+ : fold_build2 (MIN_EXPR, comp_type, comp_op1, comp_op0);
+ return pedantic_non_lvalue (fold_convert (type, tem));
+ }
+ break;
+ case GE_EXPR:
+ case GT_EXPR:
+ case UNGE_EXPR:
+ case UNGT_EXPR:
+ if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
+ {
+ comp_op0 = fold_convert (comp_type, comp_op0);
+ comp_op1 = fold_convert (comp_type, comp_op1);
+ tem = (comp_code == GE_EXPR || comp_code == UNGE_EXPR)
+ ? fold_build2 (MAX_EXPR, comp_type, comp_op0, comp_op1)
+ : fold_build2 (MAX_EXPR, comp_type, comp_op1, comp_op0);
+ return pedantic_non_lvalue (fold_convert (type, tem));
+ }
+ break;
+ case UNEQ_EXPR:
+ if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
+ return pedantic_non_lvalue (fold_convert (type, arg2));
+ break;
+ case LTGT_EXPR:
+ if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
+ return pedantic_non_lvalue (fold_convert (type, arg1));
+ break;
+ default:
+ gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
+ break;
+ }
+ }
+
+ /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
+ we might still be able to simplify this. For example,
+ if C1 is one less or one more than C2, this might have started
+ out as a MIN or MAX and been transformed by this function.
+ Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
+
+ if (INTEGRAL_TYPE_P (type)
+ && TREE_CODE (arg01) == INTEGER_CST
+ && TREE_CODE (arg2) == INTEGER_CST)
+ switch (comp_code)
+ {
+ case EQ_EXPR:
+ /* We can replace A with C1 in this case. */
+ arg1 = fold_convert (type, arg01);
+ return fold_build3 (COND_EXPR, type, arg0, arg1, arg2);
+
+ case LT_EXPR:
+ /* If C1 is C2 + 1, this is min(A, C2), but use ARG00's type for
+ MIN_EXPR, to preserve the signedness of the comparison. */
+ if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
+ OEP_ONLY_CONST)
+ && operand_equal_p (arg01,
+ const_binop (PLUS_EXPR, arg2,
+ build_int_cst (type, 1), 0),
+ OEP_ONLY_CONST))
+ {
+ tem = fold_build2 (MIN_EXPR, TREE_TYPE (arg00), arg00,
+ fold_convert (TREE_TYPE (arg00), arg2));
+ return pedantic_non_lvalue (fold_convert (type, tem));
+ }
+ break;
+
+ case LE_EXPR:
+ /* If C1 is C2 - 1, this is min(A, C2), with the same care
+ as above. */
+ if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
+ OEP_ONLY_CONST)
+ && operand_equal_p (arg01,
+ const_binop (MINUS_EXPR, arg2,
+ build_int_cst (type, 1), 0),
+ OEP_ONLY_CONST))
+ {
+ tem = fold_build2 (MIN_EXPR, TREE_TYPE (arg00), arg00,
+ fold_convert (TREE_TYPE (arg00), arg2));
+ return pedantic_non_lvalue (fold_convert (type, tem));
+ }
+ break;
+
+ case GT_EXPR:
+ /* If C1 is C2 - 1, this is max(A, C2), but use ARG00's type for
+ MAX_EXPR, to preserve the signedness of the comparison. */
+ if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
+ OEP_ONLY_CONST)
+ && operand_equal_p (arg01,
+ const_binop (MINUS_EXPR, arg2,
+ build_int_cst (type, 1), 0),
+ OEP_ONLY_CONST))
+ {
+ tem = fold_build2 (MAX_EXPR, TREE_TYPE (arg00), arg00,
+ fold_convert (TREE_TYPE (arg00), arg2));
+ return pedantic_non_lvalue (fold_convert (type, tem));
+ }
+ break;
+
+ case GE_EXPR:
+ /* If C1 is C2 + 1, this is max(A, C2), with the same care as above. */
+ if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
+ OEP_ONLY_CONST)
+ && operand_equal_p (arg01,
+ const_binop (PLUS_EXPR, arg2,
+ build_int_cst (type, 1), 0),
+ OEP_ONLY_CONST))
+ {
+ tem = fold_build2 (MAX_EXPR, TREE_TYPE (arg00), arg00,
+ fold_convert (TREE_TYPE (arg00), arg2));
+ return pedantic_non_lvalue (fold_convert (type, tem));
+ }
+ break;
+ case NE_EXPR:
+ break;
+ default:
+ gcc_unreachable ();
+ }
+
+ return NULL_TREE;
+}
+
+
+\f
+#ifndef LOGICAL_OP_NON_SHORT_CIRCUIT
+#define LOGICAL_OP_NON_SHORT_CIRCUIT \
+ (BRANCH_COST (optimize_function_for_speed_p (cfun), \
+ false) >= 2)
+#endif
+
/* EXP is some logical combination of boolean tests. See if we can
merge it into some range test. Return the new tree if so. */
static tree
-fold_range_test (exp)
- tree exp;
+fold_range_test (enum tree_code code, tree type, tree op0, tree op1)
{
- int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
- || TREE_CODE (exp) == TRUTH_OR_EXPR);
+ int or_op = (code == TRUTH_ORIF_EXPR
+ || code == TRUTH_OR_EXPR);
int in0_p, in1_p, in_p;
tree low0, low1, low, high0, high1, high;
- tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
- tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
+ bool strict_overflow_p = false;
+ tree lhs = make_range (op0, &in0_p, &low0, &high0, &strict_overflow_p);
+ tree rhs = make_range (op1, &in1_p, &low1, &high1, &strict_overflow_p);
tree tem;
+ const char * const warnmsg = G_("assuming signed overflow does not occur "
+ "when simplifying range test");
/* If this is an OR operation, invert both sides; we will invert
again at the end. */
if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
&& merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
in1_p, low1, high1)
- && 0 != (tem = (build_range_check (TREE_TYPE (exp),
+ && 0 != (tem = (build_range_check (type,
lhs != 0 ? lhs
: rhs != 0 ? rhs : integer_zero_node,
in_p, low, high))))
- return or_op ? invert_truthvalue (tem) : tem;
+ {
+ if (strict_overflow_p)
+ fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
+ return or_op ? invert_truthvalue (tem) : tem;
+ }
/* On machines where the branch cost is expensive, if this is a
short-circuited branch and the underlying object on both sides
is the same, make a non-short-circuit operation. */
- else if (BRANCH_COST >= 2
+ else if (LOGICAL_OP_NON_SHORT_CIRCUIT
&& lhs != 0 && rhs != 0
- && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
- || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
+ && (code == TRUTH_ANDIF_EXPR
+ || code == TRUTH_ORIF_EXPR)
&& operand_equal_p (lhs, rhs, 0))
{
/* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
which cases we can't do this. */
if (simple_operand_p (lhs))
- return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
- ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
- TREE_TYPE (exp), TREE_OPERAND (exp, 0),
- TREE_OPERAND (exp, 1));
+ return build2 (code == TRUTH_ANDIF_EXPR
+ ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
+ type, op0, op1);
- else if (global_bindings_p () == 0
- && ! contains_placeholder_p (lhs))
+ else if (lang_hooks.decls.global_bindings_p () == 0
+ && ! CONTAINS_PLACEHOLDER_P (lhs))
{
tree common = save_expr (lhs);
- if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
+ if (0 != (lhs = build_range_check (type, common,
or_op ? ! in0_p : in0_p,
low0, high0))
- && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
+ && (0 != (rhs = build_range_check (type, common,
or_op ? ! in1_p : in1_p,
low1, high1))))
- return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
- ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
- TREE_TYPE (exp), lhs, rhs);
+ {
+ if (strict_overflow_p)
+ fold_overflow_warning (warnmsg,
+ WARN_STRICT_OVERFLOW_COMPARISON);
+ return build2 (code == TRUTH_ANDIF_EXPR
+ ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
+ type, lhs, rhs);
+ }
}
}
it is an INTEGER_CST that should be AND'ed with the extra bits. */
static tree
-unextend (c, p, unsignedp, mask)
- tree c;
- int p;
- int unsignedp;
- tree mask;
+unextend (tree c, int p, int unsignedp, tree mask)
{
tree type = TREE_TYPE (c);
int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
do the type conversion here. At this point, the constant is either
zero or one, and the conversion to a signed type can never overflow.
We could get an overflow if this conversion is done anywhere else. */
- if (TREE_UNSIGNED (type))
- temp = convert (signed_type (type), temp);
+ if (TYPE_UNSIGNED (type))
+ temp = fold_convert (signed_type_for (type), temp);
temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
if (mask != 0)
- temp = const_binop (BIT_AND_EXPR, temp, convert (TREE_TYPE (c), mask), 0);
+ temp = const_binop (BIT_AND_EXPR, temp,
+ fold_convert (TREE_TYPE (c), mask), 0);
/* If necessary, convert the type back to match the type of C. */
- if (TREE_UNSIGNED (type))
- temp = convert (type, temp);
+ if (TYPE_UNSIGNED (type))
+ temp = fold_convert (type, temp);
- return convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
+ return fold_convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
}
\f
/* Find ways of folding logical expressions of LHS and RHS:
We return the simplified tree or 0 if no optimization is possible. */
static tree
-fold_truthop (code, truth_type, lhs, rhs)
- enum tree_code code;
- tree truth_type, lhs, rhs;
+fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
{
/* If this is the "or" of two comparisons, we can do something if
the comparisons are NE_EXPR. If this is the "and", we can do something
if the comparisons are EQ_EXPR. I.e.,
- (a->b == 2 && a->c == 4) can become (a->new == NEW).
+ (a->b == 2 && a->c == 4) can become (a->new == NEW).
WANTED_CODE is this operation code. For single bit fields, we can
convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
tree l_const, r_const;
tree lntype, rntype, result;
- int first_bit, end_bit;
+ HOST_WIDE_INT first_bit, end_bit;
int volatilep;
+ tree orig_lhs = lhs, orig_rhs = rhs;
+ enum tree_code orig_code = code;
/* Start by getting the comparison codes. Fail if anything is volatile.
If one operand is a BIT_AND_EXPR with the constant one, treat it as if
rcode = TREE_CODE (rhs);
if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
- lcode = NE_EXPR, lhs = build (NE_EXPR, truth_type, lhs, integer_zero_node);
+ {
+ lhs = build2 (NE_EXPR, truth_type, lhs,
+ build_int_cst (TREE_TYPE (lhs), 0));
+ lcode = NE_EXPR;
+ }
if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
- rcode = NE_EXPR, rhs = build (NE_EXPR, truth_type, rhs, integer_zero_node);
+ {
+ rhs = build2 (NE_EXPR, truth_type, rhs,
+ build_int_cst (TREE_TYPE (rhs), 0));
+ rcode = NE_EXPR;
+ }
- if (TREE_CODE_CLASS (lcode) != '<' || TREE_CODE_CLASS (rcode) != '<')
+ if (TREE_CODE_CLASS (lcode) != tcc_comparison
+ || TREE_CODE_CLASS (rcode) != tcc_comparison)
return 0;
- code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
- ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
-
ll_arg = TREE_OPERAND (lhs, 0);
lr_arg = TREE_OPERAND (lhs, 1);
rl_arg = TREE_OPERAND (rhs, 0);
rr_arg = TREE_OPERAND (rhs, 1);
+ /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
+ if (simple_operand_p (ll_arg)
+ && simple_operand_p (lr_arg))
+ {
+ tree result;
+ if (operand_equal_p (ll_arg, rl_arg, 0)
+ && operand_equal_p (lr_arg, rr_arg, 0))
+ {
+ result = combine_comparisons (code, lcode, rcode,
+ truth_type, ll_arg, lr_arg);
+ if (result)
+ return result;
+ }
+ else if (operand_equal_p (ll_arg, rr_arg, 0)
+ && operand_equal_p (lr_arg, rl_arg, 0))
+ {
+ result = combine_comparisons (code, lcode,
+ swap_tree_comparison (rcode),
+ truth_type, ll_arg, lr_arg);
+ if (result)
+ return result;
+ }
+ }
+
+ code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
+ ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
+
/* If the RHS can be evaluated unconditionally and its operands are
simple, it wins to evaluate the RHS unconditionally on machines
with expensive branches. In this case, this isn't a comparison
that can be merged. Avoid doing this if the RHS is a floating-point
comparison since those can trap. */
- if (BRANCH_COST >= 2
+ if (BRANCH_COST (optimize_function_for_speed_p (cfun),
+ false) >= 2
&& ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
&& simple_operand_p (rl_arg)
&& simple_operand_p (rr_arg))
- return build (code, truth_type, lhs, rhs);
+ {
+ /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
+ if (code == TRUTH_OR_EXPR
+ && lcode == NE_EXPR && integer_zerop (lr_arg)
+ && rcode == NE_EXPR && integer_zerop (rr_arg)
+ && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg)
+ && INTEGRAL_TYPE_P (TREE_TYPE (ll_arg)))
+ return build2 (NE_EXPR, truth_type,
+ build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
+ ll_arg, rl_arg),
+ build_int_cst (TREE_TYPE (ll_arg), 0));
+
+ /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
+ if (code == TRUTH_AND_EXPR
+ && lcode == EQ_EXPR && integer_zerop (lr_arg)
+ && rcode == EQ_EXPR && integer_zerop (rr_arg)
+ && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg)
+ && INTEGRAL_TYPE_P (TREE_TYPE (ll_arg)))
+ return build2 (EQ_EXPR, truth_type,
+ build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
+ ll_arg, rl_arg),
+ build_int_cst (TREE_TYPE (ll_arg), 0));
+
+ if (LOGICAL_OP_NON_SHORT_CIRCUIT)
+ {
+ if (code != orig_code || lhs != orig_lhs || rhs != orig_rhs)
+ return build2 (code, truth_type, lhs, rhs);
+ return NULL_TREE;
+ }
+ }
/* See if the comparisons can be merged. Then get all the parameters for
each side. */
lnbitsize = GET_MODE_BITSIZE (lnmode);
lnbitpos = first_bit & ~ (lnbitsize - 1);
- lntype = type_for_size (lnbitsize, 1);
+ lntype = lang_hooks.types.type_for_size (lnbitsize, 1);
xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
if (BYTES_BIG_ENDIAN)
xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
}
- ll_mask = const_binop (LSHIFT_EXPR, convert (lntype, ll_mask),
+ ll_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, ll_mask),
size_int (xll_bitpos), 0);
- rl_mask = const_binop (LSHIFT_EXPR, convert (lntype, rl_mask),
+ rl_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, rl_mask),
size_int (xrl_bitpos), 0);
if (l_const)
{
- l_const = convert (lntype, l_const);
+ l_const = fold_convert (lntype, l_const);
l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
- fold (build1 (BIT_NOT_EXPR,
- lntype, ll_mask)),
+ fold_build1 (BIT_NOT_EXPR,
+ lntype, ll_mask),
0)))
{
- warning ("comparison is always %d", wanted_code == NE_EXPR);
+ warning (0, "comparison is always %d", wanted_code == NE_EXPR);
- return convert (truth_type,
- wanted_code == NE_EXPR
- ? integer_one_node : integer_zero_node);
+ return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
}
}
if (r_const)
{
- r_const = convert (lntype, r_const);
+ r_const = fold_convert (lntype, r_const);
r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
- fold (build1 (BIT_NOT_EXPR,
- lntype, rl_mask)),
+ fold_build1 (BIT_NOT_EXPR,
+ lntype, rl_mask),
0)))
{
- warning ("comparison is always %d", wanted_code == NE_EXPR);
+ warning (0, "comparison is always %d", wanted_code == NE_EXPR);
- return convert (truth_type,
- wanted_code == NE_EXPR
- ? integer_one_node : integer_zero_node);
+ return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
}
}
rnbitsize = GET_MODE_BITSIZE (rnmode);
rnbitpos = first_bit & ~ (rnbitsize - 1);
- rntype = type_for_size (rnbitsize, 1);
+ rntype = lang_hooks.types.type_for_size (rnbitsize, 1);
xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
if (BYTES_BIG_ENDIAN)
xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
}
- lr_mask = const_binop (LSHIFT_EXPR, convert (rntype, lr_mask),
+ lr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, lr_mask),
size_int (xlr_bitpos), 0);
- rr_mask = const_binop (LSHIFT_EXPR, convert (rntype, rr_mask),
+ rr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, rr_mask),
size_int (xrr_bitpos), 0);
/* Make a mask that corresponds to both fields being compared.
lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
ll_unsignedp || rl_unsignedp);
if (! all_ones_mask_p (ll_mask, lnbitsize))
- lhs = build (BIT_AND_EXPR, lntype, lhs, ll_mask);
+ lhs = build2 (BIT_AND_EXPR, lntype, lhs, ll_mask);
rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
lr_unsignedp || rr_unsignedp);
if (! all_ones_mask_p (lr_mask, rnbitsize))
- rhs = build (BIT_AND_EXPR, rntype, rhs, lr_mask);
+ rhs = build2 (BIT_AND_EXPR, rntype, rhs, lr_mask);
- return build (wanted_code, truth_type, lhs, rhs);
+ return build2 (wanted_code, truth_type, lhs, rhs);
}
/* There is still another way we can do something: If both pairs of
{
if (lnbitsize > rnbitsize)
{
- lhs = convert (rntype, lhs);
- ll_mask = convert (rntype, ll_mask);
+ lhs = fold_convert (rntype, lhs);
+ ll_mask = fold_convert (rntype, ll_mask);
type = rntype;
}
else if (lnbitsize < rnbitsize)
{
- rhs = convert (lntype, rhs);
- lr_mask = convert (lntype, lr_mask);
+ rhs = fold_convert (lntype, rhs);
+ lr_mask = fold_convert (lntype, lr_mask);
type = lntype;
}
}
if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
- lhs = build (BIT_AND_EXPR, type, lhs, ll_mask);
+ lhs = build2 (BIT_AND_EXPR, type, lhs, ll_mask);
if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
- rhs = build (BIT_AND_EXPR, type, rhs, lr_mask);
+ rhs = build2 (BIT_AND_EXPR, type, rhs, lr_mask);
- return build (wanted_code, truth_type, lhs, rhs);
+ return build2 (wanted_code, truth_type, lhs, rhs);
}
return 0;
{
if (wanted_code == NE_EXPR)
{
- warning ("`or' of unmatched not-equal tests is always 1");
- return convert (truth_type, integer_one_node);
+ warning (0, "%<or%> of unmatched not-equal tests is always 1");
+ return constant_boolean_node (true, truth_type);
}
else
{
- warning ("`and' of mutually exclusive equal-tests is always 0");
- return convert (truth_type, integer_zero_node);
+ warning (0, "%<and%> of mutually exclusive equal-tests is always 0");
+ return constant_boolean_node (false, truth_type);
}
}
ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
if (! all_ones_mask_p (ll_mask, lnbitsize))
- result = build (BIT_AND_EXPR, lntype, result, ll_mask);
+ result = build2 (BIT_AND_EXPR, lntype, result, ll_mask);
- return build (wanted_code, truth_type, result,
- const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
+ return build2 (wanted_code, truth_type, result,
+ const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
}
\f
/* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
constant. */
static tree
-optimize_minmax_comparison (t)
- tree t;
+optimize_minmax_comparison (enum tree_code code, tree type, tree op0, tree op1)
{
- tree type = TREE_TYPE (t);
- tree arg0 = TREE_OPERAND (t, 0);
+ tree arg0 = op0;
enum tree_code op_code;
- tree comp_const = TREE_OPERAND (t, 1);
+ tree comp_const;
tree minmax_const;
int consts_equal, consts_lt;
tree inner;
op_code = TREE_CODE (arg0);
minmax_const = TREE_OPERAND (arg0, 1);
+ comp_const = fold_convert (TREE_TYPE (arg0), op1);
consts_equal = tree_int_cst_equal (minmax_const, comp_const);
consts_lt = tree_int_cst_lt (minmax_const, comp_const);
inner = TREE_OPERAND (arg0, 0);
/* If something does not permit us to optimize, return the original tree. */
if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
|| TREE_CODE (comp_const) != INTEGER_CST
- || TREE_CONSTANT_OVERFLOW (comp_const)
+ || TREE_OVERFLOW (comp_const)
|| TREE_CODE (minmax_const) != INTEGER_CST
- || TREE_CONSTANT_OVERFLOW (minmax_const))
- return t;
+ || TREE_OVERFLOW (minmax_const))
+ return NULL_TREE;
/* Now handle all the various comparison codes. We only handle EQ_EXPR
and GT_EXPR, doing the rest with recursive calls using logical
simplifications. */
- switch (TREE_CODE (t))
+ switch (code)
{
case NE_EXPR: case LT_EXPR: case LE_EXPR:
- return
- invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t)));
+ {
+ tree tem = optimize_minmax_comparison (invert_tree_comparison (code, false),
+ type, op0, op1);
+ if (tem)
+ return invert_truthvalue (tem);
+ return NULL_TREE;
+ }
case GE_EXPR:
return
- fold (build (TRUTH_ORIF_EXPR, type,
+ fold_build2 (TRUTH_ORIF_EXPR, type,
optimize_minmax_comparison
- (build (EQ_EXPR, type, arg0, comp_const)),
+ (EQ_EXPR, type, arg0, comp_const),
optimize_minmax_comparison
- (build (GT_EXPR, type, arg0, comp_const))));
+ (GT_EXPR, type, arg0, comp_const));
case EQ_EXPR:
if (op_code == MAX_EXPR && consts_equal)
/* MAX (X, 0) == 0 -> X <= 0 */
- return fold (build (LE_EXPR, type, inner, comp_const));
+ return fold_build2 (LE_EXPR, type, inner, comp_const);
else if (op_code == MAX_EXPR && consts_lt)
/* MAX (X, 0) == 5 -> X == 5 */
- return fold (build (EQ_EXPR, type, inner, comp_const));
+ return fold_build2 (EQ_EXPR, type, inner, comp_const);
else if (op_code == MAX_EXPR)
/* MAX (X, 0) == -1 -> false */
else if (consts_equal)
/* MIN (X, 0) == 0 -> X >= 0 */
- return fold (build (GE_EXPR, type, inner, comp_const));
+ return fold_build2 (GE_EXPR, type, inner, comp_const);
else if (consts_lt)
/* MIN (X, 0) == 5 -> false */
else
/* MIN (X, 0) == -1 -> X == -1 */
- return fold (build (EQ_EXPR, type, inner, comp_const));
+ return fold_build2 (EQ_EXPR, type, inner, comp_const);
case GT_EXPR:
if (op_code == MAX_EXPR && (consts_equal || consts_lt))
/* MAX (X, 0) > 0 -> X > 0
MAX (X, 0) > 5 -> X > 5 */
- return fold (build (GT_EXPR, type, inner, comp_const));
+ return fold_build2 (GT_EXPR, type, inner, comp_const);
else if (op_code == MAX_EXPR)
/* MAX (X, 0) > -1 -> true */
else
/* MIN (X, 0) > -1 -> X > -1 */
- return fold (build (GT_EXPR, type, inner, comp_const));
+ return fold_build2 (GT_EXPR, type, inner, comp_const);
default:
- return t;
+ return NULL_TREE;
}
}
\f
expression would not overflow or that overflow is undefined for the type
in the language in question.
- We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
- the machine has a multiply-accumulate insn or that this is part of an
- addressing calculation.
-
If we return a non-null expression, it is an equivalent form of the
- original computation, but need not be in the original type. */
+ original computation, but need not be in the original type.
+
+ We set *STRICT_OVERFLOW_P to true if the return values depends on
+ signed overflow being undefined. Otherwise we do not change
+ *STRICT_OVERFLOW_P. */
static tree
-extract_muldiv (t, c, code, wide_type)
- tree t;
- tree c;
- enum tree_code code;
- tree wide_type;
+extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type,
+ bool *strict_overflow_p)
{
/* To avoid exponential search depth, refuse to allow recursion past
three levels. Beyond that (1) it's highly unlikely that we'll find
return NULL;
depth++;
- ret = extract_muldiv_1 (t, c, code, wide_type);
+ ret = extract_muldiv_1 (t, c, code, wide_type, strict_overflow_p);
depth--;
return ret;
}
static tree
-extract_muldiv_1 (t, c, code, wide_type)
- tree t;
- tree c;
- enum tree_code code;
- tree wide_type;
+extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type,
+ bool *strict_overflow_p)
{
tree type = TREE_TYPE (t);
enum tree_code tcode = TREE_CODE (t);
tree t1, t2;
int same_p = tcode == code;
tree op0 = NULL_TREE, op1 = NULL_TREE;
+ bool sub_strict_overflow_p;
/* Don't deal with constants of zero here; they confuse the code below. */
if (integer_zerop (c))
return NULL_TREE;
- if (TREE_CODE_CLASS (tcode) == '1')
+ if (TREE_CODE_CLASS (tcode) == tcc_unary)
op0 = TREE_OPERAND (t, 0);
- if (TREE_CODE_CLASS (tcode) == '2')
+ if (TREE_CODE_CLASS (tcode) == tcc_binary)
op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
/* Note that we need not handle conditional operations here since fold
or (for divide and modulus) if it is a multiple of our constant. */
if (code == MULT_EXPR
|| integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
- return const_binop (code, convert (ctype, t), convert (ctype, c), 0);
+ return const_binop (code, fold_convert (ctype, t),
+ fold_convert (ctype, c), 0);
break;
- case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
- /* If op0 is an expression... */
- if ((TREE_CODE_CLASS (TREE_CODE (op0)) == '<'
- || TREE_CODE_CLASS (TREE_CODE (op0)) == '1'
- || TREE_CODE_CLASS (TREE_CODE (op0)) == '2'
- || TREE_CODE_CLASS (TREE_CODE (op0)) == 'e')
- /* ...and is unsigned, and its type is smaller than ctype,
- then we cannot pass through this widening. */
- && ((TREE_UNSIGNED (TREE_TYPE (op0))
+ CASE_CONVERT: case NON_LVALUE_EXPR:
+ /* If op0 is an expression ... */
+ if ((COMPARISON_CLASS_P (op0)
+ || UNARY_CLASS_P (op0)
+ || BINARY_CLASS_P (op0)
+ || VL_EXP_CLASS_P (op0)
+ || EXPRESSION_CLASS_P (op0))
+ /* ... and has wrapping overflow, and its type is smaller
+ than ctype, then we cannot pass through as widening. */
+ && ((TYPE_OVERFLOW_WRAPS (TREE_TYPE (op0))
&& ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
- && (GET_MODE_SIZE (TYPE_MODE (ctype))
- > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
- /* ...and its type is larger than ctype,
- then we cannot pass through this truncation. */
- || (GET_MODE_SIZE (TYPE_MODE (ctype))
- < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
+ && (TYPE_PRECISION (ctype)
+ > TYPE_PRECISION (TREE_TYPE (op0))))
+ /* ... or this is a truncation (t is narrower than op0),
+ then we cannot pass through this narrowing. */
+ || (TYPE_PRECISION (type)
+ < TYPE_PRECISION (TREE_TYPE (op0)))
/* ... or signedness changes for division or modulus,
then we cannot pass through this conversion. */
|| (code != MULT_EXPR
- && (TREE_UNSIGNED (ctype)
- != TREE_UNSIGNED (TREE_TYPE (op0))))))
+ && (TYPE_UNSIGNED (ctype)
+ != TYPE_UNSIGNED (TREE_TYPE (op0))))
+ /* ... or has undefined overflow while the converted to
+ type has not, we cannot do the operation in the inner type
+ as that would introduce undefined overflow. */
+ || (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (op0))
+ && !TYPE_OVERFLOW_UNDEFINED (type))))
break;
/* Pass the constant down and see if we can make a simplification. If
we can, replace this expression with the inner simplification for
possible later conversion to our or some other type. */
- if (0 != (t1 = extract_muldiv (op0, convert (TREE_TYPE (op0), c), code,
- code == MULT_EXPR ? ctype : NULL_TREE)))
+ if ((t2 = fold_convert (TREE_TYPE (op0), c)) != 0
+ && TREE_CODE (t2) == INTEGER_CST
+ && !TREE_OVERFLOW (t2)
+ && (0 != (t1 = extract_muldiv (op0, t2, code,
+ code == MULT_EXPR
+ ? ctype : NULL_TREE,
+ strict_overflow_p))))
return t1;
break;
- case NEGATE_EXPR: case ABS_EXPR:
- if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
- return fold (build1 (tcode, ctype, convert (ctype, t1)));
+ case ABS_EXPR:
+ /* If widening the type changes it from signed to unsigned, then we
+ must avoid building ABS_EXPR itself as unsigned. */
+ if (TYPE_UNSIGNED (ctype) && !TYPE_UNSIGNED (type))
+ {
+ tree cstype = (*signed_type_for) (ctype);
+ if ((t1 = extract_muldiv (op0, c, code, cstype, strict_overflow_p))
+ != 0)
+ {
+ t1 = fold_build1 (tcode, cstype, fold_convert (cstype, t1));
+ return fold_convert (ctype, t1);
+ }
+ break;
+ }
+ /* If the constant is negative, we cannot simplify this. */
+ if (tree_int_cst_sgn (c) == -1)
+ break;
+ /* FALLTHROUGH */
+ case NEGATE_EXPR:
+ if ((t1 = extract_muldiv (op0, c, code, wide_type, strict_overflow_p))
+ != 0)
+ return fold_build1 (tcode, ctype, fold_convert (ctype, t1));
break;
case MIN_EXPR: case MAX_EXPR:
/* If widening the type changes the signedness, then we can't perform
this optimization as that changes the result. */
- if (TREE_UNSIGNED (ctype) != TREE_UNSIGNED (type))
+ if (TYPE_UNSIGNED (ctype) != TYPE_UNSIGNED (type))
break;
/* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
- if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
- && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
+ sub_strict_overflow_p = false;
+ if ((t1 = extract_muldiv (op0, c, code, wide_type,
+ &sub_strict_overflow_p)) != 0
+ && (t2 = extract_muldiv (op1, c, code, wide_type,
+ &sub_strict_overflow_p)) != 0)
{
if (tree_int_cst_sgn (c) < 0)
tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
-
- return fold (build (tcode, ctype, convert (ctype, t1),
- convert (ctype, t2)));
- }
- break;
-
- case WITH_RECORD_EXPR:
- if ((t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code, wide_type)) != 0)
- return build (WITH_RECORD_EXPR, TREE_TYPE (t1), t1,
- TREE_OPERAND (t, 1));
- break;
-
- case SAVE_EXPR:
- /* If this has not been evaluated and the operand has no side effects,
- we can see if we can do something inside it and make a new one.
- Note that this test is overly conservative since we can do this
- if the only reason it had side effects is that it was another
- similar SAVE_EXPR, but that isn't worth bothering with. */
- if (SAVE_EXPR_RTL (t) == 0 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0))
- && 0 != (t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code,
- wide_type)))
- {
- t1 = save_expr (t1);
- if (SAVE_EXPR_PERSISTENT_P (t) && TREE_CODE (t1) == SAVE_EXPR)
- SAVE_EXPR_PERSISTENT_P (t1) = 1;
- if (is_pending_size (t))
- put_pending_size (t1);
- return t1;
+ if (sub_strict_overflow_p)
+ *strict_overflow_p = true;
+ return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
+ fold_convert (ctype, t2));
}
break;
case LSHIFT_EXPR: case RSHIFT_EXPR:
/* If the second operand is constant, this is a multiplication
or floor division, by a power of two, so we can treat it that
- way unless the multiplier or divisor overflows. */
+ way unless the multiplier or divisor overflows. Signed
+ left-shift overflow is implementation-defined rather than
+ undefined in C90, so do not convert signed left shift into
+ multiplication. */
if (TREE_CODE (op1) == INTEGER_CST
+ && (tcode == RSHIFT_EXPR || TYPE_UNSIGNED (TREE_TYPE (op0)))
/* const_binop may not detect overflow correctly,
so check for it explicitly here. */
&& TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
&& TREE_INT_CST_HIGH (op1) == 0
- && 0 != (t1 = convert (ctype,
- const_binop (LSHIFT_EXPR, size_one_node,
- op1, 0)))
- && ! TREE_OVERFLOW (t1))
- return extract_muldiv (build (tcode == LSHIFT_EXPR
- ? MULT_EXPR : FLOOR_DIV_EXPR,
- ctype, convert (ctype, op0), t1),
- c, code, wide_type);
+ && 0 != (t1 = fold_convert (ctype,
+ const_binop (LSHIFT_EXPR,
+ size_one_node,
+ op1, 0)))
+ && !TREE_OVERFLOW (t1))
+ return extract_muldiv (build2 (tcode == LSHIFT_EXPR
+ ? MULT_EXPR : FLOOR_DIV_EXPR,
+ ctype, fold_convert (ctype, op0), t1),
+ c, code, wide_type, strict_overflow_p);
break;
case PLUS_EXPR: case MINUS_EXPR:
can return a new PLUS or MINUS. If we can't, the only remaining
cases where we can do anything are if the second operand is a
constant. */
- t1 = extract_muldiv (op0, c, code, wide_type);
- t2 = extract_muldiv (op1, c, code, wide_type);
+ sub_strict_overflow_p = false;
+ t1 = extract_muldiv (op0, c, code, wide_type, &sub_strict_overflow_p);
+ t2 = extract_muldiv (op1, c, code, wide_type, &sub_strict_overflow_p);
if (t1 != 0 && t2 != 0
&& (code == MULT_EXPR
/* If not multiplication, we can only do this if both operands
are divisible by c. */
|| (multiple_of_p (ctype, op0, c)
&& multiple_of_p (ctype, op1, c))))
- return fold (build (tcode, ctype, convert (ctype, t1),
- convert (ctype, t2)));
+ {
+ if (sub_strict_overflow_p)
+ *strict_overflow_p = true;
+ return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
+ fold_convert (ctype, t2));
+ }
/* If this was a subtraction, negate OP1 and set it to be an addition.
This simplifies the logic below. */
of our constant, do the operation and verify it doesn't overflow. */
if (code == MULT_EXPR
|| integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
- {
- op1 = const_binop (code, convert (ctype, op1), convert (ctype, c), 0);
- if (op1 == 0 || TREE_OVERFLOW (op1))
- break;
- }
+ {
+ op1 = const_binop (code, fold_convert (ctype, op1),
+ fold_convert (ctype, c), 0);
+ /* We allow the constant to overflow with wrapping semantics. */
+ if (op1 == 0
+ || (TREE_OVERFLOW (op1) && !TYPE_OVERFLOW_WRAPS (ctype)))
+ break;
+ }
else
- break;
+ break;
/* If we have an unsigned type is not a sizetype, we cannot widen
the operation since it will change the result if the original
computation overflowed. */
- if (TREE_UNSIGNED (ctype)
+ if (TYPE_UNSIGNED (ctype)
&& ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
&& ctype != type)
break;
/* If we were able to eliminate our operation from the first side,
apply our operation to the second side and reform the PLUS. */
if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
- return fold (build (tcode, ctype, convert (ctype, t1), op1));
+ return fold_build2 (tcode, ctype, fold_convert (ctype, t1), op1);
/* The last case is if we are a multiply. In that case, we can
apply the distributive law to commute the multiply and addition
if the multiplication of the constants doesn't overflow. */
if (code == MULT_EXPR)
- return fold (build (tcode, ctype, fold (build (code, ctype,
- convert (ctype, op0),
- convert (ctype, c))),
- op1));
+ return fold_build2 (tcode, ctype,
+ fold_build2 (code, ctype,
+ fold_convert (ctype, op0),
+ fold_convert (ctype, c)),
+ op1);
break;
(C * 8) % 4 since we know that's zero. */
if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
|| code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
+ /* If the multiplication can overflow we cannot optimize this.
+ ??? Until we can properly mark individual operations as
+ not overflowing we need to treat sizetype special here as
+ stor-layout relies on this opimization to make
+ DECL_FIELD_BIT_OFFSET always a constant. */
+ && (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (t))
+ || (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
+ && TYPE_IS_SIZETYPE (TREE_TYPE (t))))
&& TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
&& integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
- return omit_one_operand (type, integer_zero_node, op0);
+ {
+ *strict_overflow_p = true;
+ return omit_one_operand (type, integer_zero_node, op0);
+ }
/* ... fall through ... */
new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
do something only if the second operand is a constant. */
if (same_p
- && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
- return fold (build (tcode, ctype, convert (ctype, t1),
- convert (ctype, op1)));
+ && (t1 = extract_muldiv (op0, c, code, wide_type,
+ strict_overflow_p)) != 0)
+ return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
+ fold_convert (ctype, op1));
else if (tcode == MULT_EXPR && code == MULT_EXPR
- && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
- return fold (build (tcode, ctype, convert (ctype, op0),
- convert (ctype, t1)));
+ && (t1 = extract_muldiv (op1, c, code, wide_type,
+ strict_overflow_p)) != 0)
+ return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
+ fold_convert (ctype, t1));
else if (TREE_CODE (op1) != INTEGER_CST)
return 0;
/* If these are the same operation types, we can associate them
assuming no overflow. */
if (tcode == code
- && 0 != (t1 = const_binop (MULT_EXPR, convert (ctype, op1),
- convert (ctype, c), 0))
- && ! TREE_OVERFLOW (t1))
- return fold (build (tcode, ctype, convert (ctype, op0), t1));
+ && 0 != (t1 = int_const_binop (MULT_EXPR, fold_convert (ctype, op1),
+ fold_convert (ctype, c), 1))
+ && 0 != (t1 = force_fit_type_double (ctype, TREE_INT_CST_LOW (t1),
+ TREE_INT_CST_HIGH (t1),
+ (TYPE_UNSIGNED (ctype)
+ && tcode != MULT_EXPR) ? -1 : 1,
+ TREE_OVERFLOW (t1)))
+ && !TREE_OVERFLOW (t1))
+ return fold_build2 (tcode, ctype, fold_convert (ctype, op0), t1);
/* If these operations "cancel" each other, we have the main
optimizations of this pass, which occur when either constant is a
If we have an unsigned type that is not a sizetype, we cannot do
this since it will change the result if the original computation
overflowed. */
- if ((! TREE_UNSIGNED (ctype)
+ if ((TYPE_OVERFLOW_UNDEFINED (ctype)
|| (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
&& ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
|| (tcode == MULT_EXPR
&& code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
- && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
+ && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR
+ && code != MULT_EXPR)))
{
if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
- return fold (build (tcode, ctype, convert (ctype, op0),
- convert (ctype,
- const_binop (TRUNC_DIV_EXPR,
- op1, c, 0))));
+ {
+ if (TYPE_OVERFLOW_UNDEFINED (ctype))
+ *strict_overflow_p = true;
+ return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
+ fold_convert (ctype,
+ const_binop (TRUNC_DIV_EXPR,
+ op1, c, 0)));
+ }
else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
- return fold (build (code, ctype, convert (ctype, op0),
- convert (ctype,
- const_binop (TRUNC_DIV_EXPR,
- c, op1, 0))));
+ {
+ if (TYPE_OVERFLOW_UNDEFINED (ctype))
+ *strict_overflow_p = true;
+ return fold_build2 (code, ctype, fold_convert (ctype, op0),
+ fold_convert (ctype,
+ const_binop (TRUNC_DIV_EXPR,
+ c, op1, 0)));
+ }
}
break;
return 0;
}
\f
-/* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
- S, a SAVE_EXPR, return the expression actually being evaluated. Note
- that we may sometimes modify the tree. */
-
-static tree
-strip_compound_expr (t, s)
- tree t;
- tree s;
-{
- enum tree_code code = TREE_CODE (t);
-
- /* See if this is the COMPOUND_EXPR we want to eliminate. */
- if (code == COMPOUND_EXPR && TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR
- && TREE_OPERAND (TREE_OPERAND (t, 0), 0) == s)
- return TREE_OPERAND (t, 1);
-
- /* See if this is a COND_EXPR or a simple arithmetic operator. We
- don't bother handling any other types. */
- else if (code == COND_EXPR)
- {
- TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
- TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
- TREE_OPERAND (t, 2) = strip_compound_expr (TREE_OPERAND (t, 2), s);
- }
- else if (TREE_CODE_CLASS (code) == '1')
- TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
- else if (TREE_CODE_CLASS (code) == '<'
- || TREE_CODE_CLASS (code) == '2')
- {
- TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
- TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
- }
-
- return t;
-}
-\f
/* Return a node which has the indicated constant VALUE (either 0 or
1), and is of the indicated TYPE. */
-static tree
-constant_boolean_node (value, type)
- int value;
- tree type;
+tree
+constant_boolean_node (int value, tree type)
{
if (type == integer_type_node)
return value ? integer_one_node : integer_zero_node;
- else if (TREE_CODE (type) == BOOLEAN_TYPE)
- return truthvalue_conversion (value ? integer_one_node :
- integer_zero_node);
+ else if (type == boolean_type_node)
+ return value ? boolean_true_node : boolean_false_node;
else
- {
- tree t = build_int_2 (value, 0);
-
- TREE_TYPE (t) = type;
- return t;
- }
+ return build_int_cst (type, value);
}
-/* Utility function for the following routine, to see how complex a nesting of
- COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
- we don't care (to avoid spending too much time on complex expressions.). */
-
-static int
-count_cond (expr, lim)
- tree expr;
- int lim;
-{
- int ctrue, cfalse;
-
- if (TREE_CODE (expr) != COND_EXPR)
- return 0;
- else if (lim <= 0)
- return 0;
-
- ctrue = count_cond (TREE_OPERAND (expr, 1), lim - 1);
- cfalse = count_cond (TREE_OPERAND (expr, 2), lim - 1 - ctrue);
- return MIN (lim, 1 + ctrue + cfalse);
-}
-/* Transform `a + (b ? x : y)' into `x ? (a + b) : (a + y)'.
+/* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
- expression, and ARG to `a'. If COND_FIRST_P is non-zero, then the
+ expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
COND is the first argument to CODE; otherwise (as in the example
given here), it is the second argument. TYPE is the type of the
- original expression. */
+ original expression. Return NULL_TREE if no simplification is
+ possible. */
static tree
-fold_binary_op_with_conditional_arg (code, type, cond, arg, cond_first_p)
- enum tree_code code;
- tree type;
- tree cond;
- tree arg;
- int cond_first_p;
+fold_binary_op_with_conditional_arg (enum tree_code code,
+ tree type, tree op0, tree op1,
+ tree cond, tree arg, int cond_first_p)
{
+ tree cond_type = cond_first_p ? TREE_TYPE (op0) : TREE_TYPE (op1);
+ tree arg_type = cond_first_p ? TREE_TYPE (op1) : TREE_TYPE (op0);
tree test, true_value, false_value;
tree lhs = NULL_TREE;
tree rhs = NULL_TREE;
- /* In the end, we'll produce a COND_EXPR. Both arms of the
- conditional expression will be binary operations. The left-hand
- side of the expression to be executed if the condition is true
- will be pointed to by TRUE_LHS. Similarly, the right-hand side
- of the expression to be executed if the condition is true will be
- pointed to by TRUE_RHS. FALSE_LHS and FALSE_RHS are analogous --
- but apply to the expression to be executed if the conditional is
- false. */
- tree *true_lhs;
- tree *true_rhs;
- tree *false_lhs;
- tree *false_rhs;
- /* These are the codes to use for the left-hand side and right-hand
- side of the COND_EXPR. Normally, they are the same as CODE. */
- enum tree_code lhs_code = code;
- enum tree_code rhs_code = code;
- /* And these are the types of the expressions. */
- tree lhs_type = type;
- tree rhs_type = type;
- int save = 0;
-
- if (cond_first_p)
- {
- true_rhs = false_rhs = &arg;
- true_lhs = &true_value;
- false_lhs = &false_value;
- }
- else
- {
- true_lhs = false_lhs = &arg;
- true_rhs = &true_value;
- false_rhs = &false_value;
- }
+
+ /* This transformation is only worthwhile if we don't have to wrap
+ arg in a SAVE_EXPR, and the operation can be simplified on at least
+ one of the branches once its pushed inside the COND_EXPR. */
+ if (!TREE_CONSTANT (arg))
+ return NULL_TREE;
if (TREE_CODE (cond) == COND_EXPR)
{
false_value = TREE_OPERAND (cond, 2);
/* If this operand throws an expression, then it does not make
sense to try to perform a logical or arithmetic operation
- involving it. Instead of building `a + throw 3' for example,
- we simply build `a, throw 3'. */
+ involving it. */
if (VOID_TYPE_P (TREE_TYPE (true_value)))
- {
- lhs_code = COMPOUND_EXPR;
- if (!cond_first_p)
- lhs_type = void_type_node;
- }
+ lhs = true_value;
if (VOID_TYPE_P (TREE_TYPE (false_value)))
- {
- rhs_code = COMPOUND_EXPR;
- if (!cond_first_p)
- rhs_type = void_type_node;
- }
+ rhs = false_value;
}
else
{
tree testtype = TREE_TYPE (cond);
test = cond;
- true_value = convert (testtype, integer_one_node);
- false_value = convert (testtype, integer_zero_node);
- }
-
- /* If ARG is complex we want to make sure we only evaluate
- it once. Though this is only required if it is volatile, it
- might be more efficient even if it is not. However, if we
- succeed in folding one part to a constant, we do not need
- to make this SAVE_EXPR. Since we do this optimization
- primarily to see if we do end up with constant and this
- SAVE_EXPR interferes with later optimizations, suppressing
- it when we can is important.
-
- If we are not in a function, we can't make a SAVE_EXPR, so don't
- try to do so. Don't try to see if the result is a constant
- if an arm is a COND_EXPR since we get exponential behavior
- in that case. */
-
- if (TREE_CODE (arg) == SAVE_EXPR)
- save = 1;
- else if (! TREE_CONSTANT (arg)
- && global_bindings_p () == 0
- && ((TREE_CODE (arg) != VAR_DECL && TREE_CODE (arg) != PARM_DECL)
- || TREE_SIDE_EFFECTS (arg)))
- {
- if (TREE_CODE (true_value) != COND_EXPR)
- lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs));
-
- if (TREE_CODE (false_value) != COND_EXPR)
- rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs));
-
- if ((lhs == 0 || ! TREE_CONSTANT (lhs))
- && (rhs == 0 || !TREE_CONSTANT (rhs)))
- {
- arg = save_expr (arg);
- lhs = rhs = 0;
- save = 1;
- }
+ true_value = constant_boolean_node (true, testtype);
+ false_value = constant_boolean_node (false, testtype);
}
-
+
+ arg = fold_convert (arg_type, arg);
if (lhs == 0)
- lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs));
+ {
+ true_value = fold_convert (cond_type, true_value);
+ if (cond_first_p)
+ lhs = fold_build2 (code, type, true_value, arg);
+ else
+ lhs = fold_build2 (code, type, arg, true_value);
+ }
if (rhs == 0)
- rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs));
-
- test = fold (build (COND_EXPR, type, test, lhs, rhs));
-
- if (save)
- return build (COMPOUND_EXPR, type,
- convert (void_type_node, arg),
- strip_compound_expr (test, arg));
- else
- return convert (type, test);
+ {
+ false_value = fold_convert (cond_type, false_value);
+ if (cond_first_p)
+ rhs = fold_build2 (code, type, false_value, arg);
+ else
+ rhs = fold_build2 (code, type, arg, false_value);
+ }
+
+ test = fold_build3 (COND_EXPR, type, test, lhs, rhs);
+ return fold_convert (type, test);
}
\f
-/* Perform constant folding and related simplification of EXPR.
- The related simplifications include x*1 => x, x*0 => 0, etc.,
- and application of the associative law.
- NOP_EXPR conversions may be removed freely (as long as we
- are careful not to change the C type of the overall expression)
- We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
- but we can constant-fold them if they have constant operands. */
+/* Subroutine of fold() that checks for the addition of +/- 0.0.
-tree
-fold (expr)
- tree expr;
+ If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
+ TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
+ ADDEND is the same as X.
+
+ X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
+ and finite. The problematic cases are when X is zero, and its mode
+ has signed zeros. In the case of rounding towards -infinity,
+ X - 0 is not the same as X because 0 - 0 is -0. In other rounding
+ modes, X + 0 is not the same as X because -0 + 0 is 0. */
+
+bool
+fold_real_zero_addition_p (const_tree type, const_tree addend, int negate)
{
- tree t = expr;
- tree t1 = NULL_TREE;
- tree tem;
- tree type = TREE_TYPE (expr);
- tree arg0 = NULL_TREE, arg1 = NULL_TREE;
- enum tree_code code = TREE_CODE (t);
- int kind = TREE_CODE_CLASS (code);
- int invert;
- /* WINS will be nonzero when the switch is done
- if all operands are constant. */
- int wins = 1;
-
- /* Don't try to process an RTL_EXPR since its operands aren't trees.
- Likewise for a SAVE_EXPR that's already been evaluated. */
- if (code == RTL_EXPR || (code == SAVE_EXPR && SAVE_EXPR_RTL (t) != 0))
- return t;
+ if (!real_zerop (addend))
+ return false;
+
+ /* Don't allow the fold with -fsignaling-nans. */
+ if (HONOR_SNANS (TYPE_MODE (type)))
+ return false;
+
+ /* Allow the fold if zeros aren't signed, or their sign isn't important. */
+ if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
+ return true;
+
+ /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
+ if (TREE_CODE (addend) == REAL_CST
+ && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
+ negate = !negate;
+
+ /* The mode has signed zeros, and we have to honor their sign.
+ In this situation, there is only one case we can return true for.
+ X - 0 is the same as X unless rounding towards -infinity is
+ supported. */
+ return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
+}
- /* Return right away if a constant. */
- if (kind == 'c')
- return t;
+/* Subroutine of fold() that checks comparisons of built-in math
+ functions against real constants.
-#ifdef MAX_INTEGER_COMPUTATION_MODE
- check_max_integer_computation_mode (expr);
-#endif
+ FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
+ operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
+ is the type of the result and ARG0 and ARG1 are the operands of the
+ comparison. ARG1 must be a TREE_REAL_CST.
+
+ The function returns the constant folded tree if a simplification
+ can be made, and NULL_TREE otherwise. */
+
+static tree
+fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
+ tree type, tree arg0, tree arg1)
+{
+ REAL_VALUE_TYPE c;
- if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
+ if (BUILTIN_SQRT_P (fcode))
{
- tree subop;
+ tree arg = CALL_EXPR_ARG (arg0, 0);
+ enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
- /* Special case for conversion ops that can have fixed point args. */
- arg0 = TREE_OPERAND (t, 0);
+ c = TREE_REAL_CST (arg1);
+ if (REAL_VALUE_NEGATIVE (c))
+ {
+ /* sqrt(x) < y is always false, if y is negative. */
+ if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
+ return omit_one_operand (type, integer_zero_node, arg);
+
+ /* sqrt(x) > y is always true, if y is negative and we
+ don't care about NaNs, i.e. negative values of x. */
+ if (code == NE_EXPR || !HONOR_NANS (mode))
+ return omit_one_operand (type, integer_one_node, arg);
+
+ /* sqrt(x) > y is the same as x >= 0, if y is negative. */
+ return fold_build2 (GE_EXPR, type, arg,
+ build_real (TREE_TYPE (arg), dconst0));
+ }
+ else if (code == GT_EXPR || code == GE_EXPR)
+ {
+ REAL_VALUE_TYPE c2;
- /* Don't use STRIP_NOPS, because signedness of argument type matters. */
- if (arg0 != 0)
- STRIP_SIGN_NOPS (arg0);
+ REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
+ real_convert (&c2, mode, &c2);
- if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
- subop = TREE_REALPART (arg0);
- else
- subop = arg0;
+ if (REAL_VALUE_ISINF (c2))
+ {
+ /* sqrt(x) > y is x == +Inf, when y is very large. */
+ if (HONOR_INFINITIES (mode))
+ return fold_build2 (EQ_EXPR, type, arg,
+ build_real (TREE_TYPE (arg), c2));
+
+ /* sqrt(x) > y is always false, when y is very large
+ and we don't care about infinities. */
+ return omit_one_operand (type, integer_zero_node, arg);
+ }
- if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
-#if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
- && TREE_CODE (subop) != REAL_CST
-#endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
- )
- /* Note that TREE_CONSTANT isn't enough:
- static var addresses are constant but we can't
- do arithmetic on them. */
- wins = 0;
- }
- else if (IS_EXPR_CODE_CLASS (kind) || kind == 'r')
- {
- int len = first_rtl_op (code);
- int i;
- for (i = 0; i < len; i++)
+ /* sqrt(x) > c is the same as x > c*c. */
+ return fold_build2 (code, type, arg,
+ build_real (TREE_TYPE (arg), c2));
+ }
+ else if (code == LT_EXPR || code == LE_EXPR)
{
- tree op = TREE_OPERAND (t, i);
- tree subop;
+ REAL_VALUE_TYPE c2;
- if (op == 0)
- continue; /* Valid for CALL_EXPR, at least. */
+ REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
+ real_convert (&c2, mode, &c2);
- if (kind == '<' || code == RSHIFT_EXPR)
+ if (REAL_VALUE_ISINF (c2))
{
- /* Signedness matters here. Perhaps we can refine this
- later. */
- STRIP_SIGN_NOPS (op);
+ /* sqrt(x) < y is always true, when y is a very large
+ value and we don't care about NaNs or Infinities. */
+ if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
+ return omit_one_operand (type, integer_one_node, arg);
+
+ /* sqrt(x) < y is x != +Inf when y is very large and we
+ don't care about NaNs. */
+ if (! HONOR_NANS (mode))
+ return fold_build2 (NE_EXPR, type, arg,
+ build_real (TREE_TYPE (arg), c2));
+
+ /* sqrt(x) < y is x >= 0 when y is very large and we
+ don't care about Infinities. */
+ if (! HONOR_INFINITIES (mode))
+ return fold_build2 (GE_EXPR, type, arg,
+ build_real (TREE_TYPE (arg), dconst0));
+
+ /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
+ if (lang_hooks.decls.global_bindings_p () != 0
+ || CONTAINS_PLACEHOLDER_P (arg))
+ return NULL_TREE;
+
+ arg = save_expr (arg);
+ return fold_build2 (TRUTH_ANDIF_EXPR, type,
+ fold_build2 (GE_EXPR, type, arg,
+ build_real (TREE_TYPE (arg),
+ dconst0)),
+ fold_build2 (NE_EXPR, type, arg,
+ build_real (TREE_TYPE (arg),
+ c2)));
}
- else
- /* Strip any conversions that don't change the mode. */
- STRIP_NOPS (op);
-
- if (TREE_CODE (op) == COMPLEX_CST)
- subop = TREE_REALPART (op);
- else
- subop = op;
- if (TREE_CODE (subop) != INTEGER_CST
-#if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
- && TREE_CODE (subop) != REAL_CST
-#endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
- )
- /* Note that TREE_CONSTANT isn't enough:
- static var addresses are constant but we can't
- do arithmetic on them. */
- wins = 0;
+ /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
+ if (! HONOR_NANS (mode))
+ return fold_build2 (code, type, arg,
+ build_real (TREE_TYPE (arg), c2));
- if (i == 0)
- arg0 = op;
- else if (i == 1)
- arg1 = op;
+ /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
+ if (lang_hooks.decls.global_bindings_p () == 0
+ && ! CONTAINS_PLACEHOLDER_P (arg))
+ {
+ arg = save_expr (arg);
+ return fold_build2 (TRUTH_ANDIF_EXPR, type,
+ fold_build2 (GE_EXPR, type, arg,
+ build_real (TREE_TYPE (arg),
+ dconst0)),
+ fold_build2 (code, type, arg,
+ build_real (TREE_TYPE (arg),
+ c2)));
+ }
}
}
- /* If this is a commutative operation, and ARG0 is a constant, move it
- to ARG1 to reduce the number of tests below. */
- if ((code == PLUS_EXPR || code == MULT_EXPR || code == MIN_EXPR
- || code == MAX_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR
- || code == BIT_AND_EXPR)
- && (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST))
- {
- tem = arg0; arg0 = arg1; arg1 = tem;
+ return NULL_TREE;
+}
- tem = TREE_OPERAND (t, 0); TREE_OPERAND (t, 0) = TREE_OPERAND (t, 1);
- TREE_OPERAND (t, 1) = tem;
- }
+/* Subroutine of fold() that optimizes comparisons against Infinities,
+ either +Inf or -Inf.
- /* Now WINS is set as described above,
- ARG0 is the first operand of EXPR,
- and ARG1 is the second operand (if it has more than one operand).
+ CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
+ GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
+ are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
- First check for cases where an arithmetic operation is applied to a
- compound, conditional, or comparison operation. Push the arithmetic
- operation inside the compound or conditional to see if any folding
- can then be done. Convert comparison to conditional for this purpose.
- The also optimizes non-constant cases that used to be done in
- expand_expr.
+ The function returns the constant folded tree if a simplification
+ can be made, and NULL_TREE otherwise. */
- Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
- one of the operands is a comparison and the other is a comparison, a
- BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
- code below would make the expression more complex. Change it to a
- TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
- TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
+static tree
+fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
+{
+ enum machine_mode mode;
+ REAL_VALUE_TYPE max;
+ tree temp;
+ bool neg;
- if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
- || code == EQ_EXPR || code == NE_EXPR)
- && ((truth_value_p (TREE_CODE (arg0))
- && (truth_value_p (TREE_CODE (arg1))
- || (TREE_CODE (arg1) == BIT_AND_EXPR
- && integer_onep (TREE_OPERAND (arg1, 1)))))
- || (truth_value_p (TREE_CODE (arg1))
- && (truth_value_p (TREE_CODE (arg0))
- || (TREE_CODE (arg0) == BIT_AND_EXPR
- && integer_onep (TREE_OPERAND (arg0, 1)))))))
+ mode = TYPE_MODE (TREE_TYPE (arg0));
+
+ /* For negative infinity swap the sense of the comparison. */
+ neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
+ if (neg)
+ code = swap_tree_comparison (code);
+
+ switch (code)
{
- t = fold (build (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
- : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
- : TRUTH_XOR_EXPR,
- type, arg0, arg1));
+ case GT_EXPR:
+ /* x > +Inf is always false, if with ignore sNANs. */
+ if (HONOR_SNANS (mode))
+ return NULL_TREE;
+ return omit_one_operand (type, integer_zero_node, arg0);
- if (code == EQ_EXPR)
- t = invert_truthvalue (t);
+ case LE_EXPR:
+ /* x <= +Inf is always true, if we don't case about NaNs. */
+ if (! HONOR_NANS (mode))
+ return omit_one_operand (type, integer_one_node, arg0);
- return t;
+ /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
+ if (lang_hooks.decls.global_bindings_p () == 0
+ && ! CONTAINS_PLACEHOLDER_P (arg0))
+ {
+ arg0 = save_expr (arg0);
+ return fold_build2 (EQ_EXPR, type, arg0, arg0);
+ }
+ break;
+
+ case EQ_EXPR:
+ case GE_EXPR:
+ /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
+ real_maxval (&max, neg, mode);
+ return fold_build2 (neg ? LT_EXPR : GT_EXPR, type,
+ arg0, build_real (TREE_TYPE (arg0), max));
+
+ case LT_EXPR:
+ /* x < +Inf is always equal to x <= DBL_MAX. */
+ real_maxval (&max, neg, mode);
+ return fold_build2 (neg ? GE_EXPR : LE_EXPR, type,
+ arg0, build_real (TREE_TYPE (arg0), max));
+
+ case NE_EXPR:
+ /* x != +Inf is always equal to !(x > DBL_MAX). */
+ real_maxval (&max, neg, mode);
+ if (! HONOR_NANS (mode))
+ return fold_build2 (neg ? GE_EXPR : LE_EXPR, type,
+ arg0, build_real (TREE_TYPE (arg0), max));
+
+ temp = fold_build2 (neg ? LT_EXPR : GT_EXPR, type,
+ arg0, build_real (TREE_TYPE (arg0), max));
+ return fold_build1 (TRUTH_NOT_EXPR, type, temp);
+
+ default:
+ break;
}
- if (TREE_CODE_CLASS (code) == '1')
- {
- if (TREE_CODE (arg0) == COMPOUND_EXPR)
- return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
- fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
- else if (TREE_CODE (arg0) == COND_EXPR)
- {
- t = fold (build (COND_EXPR, type, TREE_OPERAND (arg0, 0),
- fold (build1 (code, type, TREE_OPERAND (arg0, 1))),
- fold (build1 (code, type, TREE_OPERAND (arg0, 2)))));
+ return NULL_TREE;
+}
- /* If this was a conversion, and all we did was to move into
- inside the COND_EXPR, bring it back out. But leave it if
- it is a conversion from integer to integer and the
- result precision is no wider than a word since such a
- conversion is cheap and may be optimized away by combine,
- while it couldn't if it were outside the COND_EXPR. Then return
- so we don't get into an infinite recursion loop taking the
- conversion out and then back in. */
+/* Subroutine of fold() that optimizes comparisons of a division by
+ a nonzero integer constant against an integer constant, i.e.
+ X/C1 op C2.
- if ((code == NOP_EXPR || code == CONVERT_EXPR
- || code == NON_LVALUE_EXPR)
- && TREE_CODE (t) == COND_EXPR
- && TREE_CODE (TREE_OPERAND (t, 1)) == code
- && TREE_CODE (TREE_OPERAND (t, 2)) == code
- && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))
- == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 2), 0)))
- && ! (INTEGRAL_TYPE_P (TREE_TYPE (t))
- && (INTEGRAL_TYPE_P
- (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))))
- && TYPE_PRECISION (TREE_TYPE (t)) <= BITS_PER_WORD))
- t = build1 (code, type,
- build (COND_EXPR,
- TREE_TYPE (TREE_OPERAND
- (TREE_OPERAND (t, 1), 0)),
- TREE_OPERAND (t, 0),
- TREE_OPERAND (TREE_OPERAND (t, 1), 0),
- TREE_OPERAND (TREE_OPERAND (t, 2), 0)));
- return t;
- }
- else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
- return fold (build (COND_EXPR, type, arg0,
- fold (build1 (code, type, integer_one_node)),
- fold (build1 (code, type, integer_zero_node))));
- }
- else if (TREE_CODE_CLASS (code) == '2'
- || TREE_CODE_CLASS (code) == '<')
- {
- if (TREE_CODE (arg1) == COMPOUND_EXPR)
- return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
- fold (build (code, type,
- arg0, TREE_OPERAND (arg1, 1))));
- else if ((TREE_CODE (arg1) == COND_EXPR
- || (TREE_CODE_CLASS (TREE_CODE (arg1)) == '<'
- && TREE_CODE_CLASS (code) != '<'))
- && (TREE_CODE (arg0) != COND_EXPR
- || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
- && (! TREE_SIDE_EFFECTS (arg0)
- || (global_bindings_p () == 0
- && ! contains_placeholder_p (arg0))))
- return
- fold_binary_op_with_conditional_arg (code, type, arg1, arg0,
- /*cond_first_p=*/0);
- else if (TREE_CODE (arg0) == COMPOUND_EXPR)
- return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
- fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
- else if ((TREE_CODE (arg0) == COND_EXPR
- || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
- && TREE_CODE_CLASS (code) != '<'))
- && (TREE_CODE (arg1) != COND_EXPR
- || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
- && (! TREE_SIDE_EFFECTS (arg1)
- || (global_bindings_p () == 0
- && ! contains_placeholder_p (arg1))))
- return
- fold_binary_op_with_conditional_arg (code, type, arg0, arg1,
- /*cond_first_p=*/1);
- }
- else if (TREE_CODE_CLASS (code) == '<'
- && TREE_CODE (arg0) == COMPOUND_EXPR)
- return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
- fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
- else if (TREE_CODE_CLASS (code) == '<'
- && TREE_CODE (arg1) == COMPOUND_EXPR)
- return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
- fold (build (code, type, arg0, TREE_OPERAND (arg1, 1))));
+ CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
+ GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
+ are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
- switch (code)
+ The function returns the constant folded tree if a simplification
+ can be made, and NULL_TREE otherwise. */
+
+static tree
+fold_div_compare (enum tree_code code, tree type, tree arg0, tree arg1)
+{
+ tree prod, tmp, hi, lo;
+ tree arg00 = TREE_OPERAND (arg0, 0);
+ tree arg01 = TREE_OPERAND (arg0, 1);
+ unsigned HOST_WIDE_INT lpart;
+ HOST_WIDE_INT hpart;
+ bool unsigned_p = TYPE_UNSIGNED (TREE_TYPE (arg0));
+ bool neg_overflow;
+ int overflow;
+
+ /* We have to do this the hard way to detect unsigned overflow.
+ prod = int_const_binop (MULT_EXPR, arg01, arg1, 0); */
+ overflow = mul_double_with_sign (TREE_INT_CST_LOW (arg01),
+ TREE_INT_CST_HIGH (arg01),
+ TREE_INT_CST_LOW (arg1),
+ TREE_INT_CST_HIGH (arg1),
+ &lpart, &hpart, unsigned_p);
+ prod = force_fit_type_double (TREE_TYPE (arg00), lpart, hpart,
+ -1, overflow);
+ neg_overflow = false;
+
+ if (unsigned_p)
{
- case INTEGER_CST:
- case REAL_CST:
- case VECTOR_CST:
- case STRING_CST:
- case COMPLEX_CST:
- case CONSTRUCTOR:
- return t;
+ tmp = int_const_binop (MINUS_EXPR, arg01,
+ build_int_cst (TREE_TYPE (arg01), 1), 0);
+ lo = prod;
+
+ /* Likewise hi = int_const_binop (PLUS_EXPR, prod, tmp, 0). */
+ overflow = add_double_with_sign (TREE_INT_CST_LOW (prod),
+ TREE_INT_CST_HIGH (prod),
+ TREE_INT_CST_LOW (tmp),
+ TREE_INT_CST_HIGH (tmp),
+ &lpart, &hpart, unsigned_p);
+ hi = force_fit_type_double (TREE_TYPE (arg00), lpart, hpart,
+ -1, overflow | TREE_OVERFLOW (prod));
+ }
+ else if (tree_int_cst_sgn (arg01) >= 0)
+ {
+ tmp = int_const_binop (MINUS_EXPR, arg01,
+ build_int_cst (TREE_TYPE (arg01), 1), 0);
+ switch (tree_int_cst_sgn (arg1))
+ {
+ case -1:
+ neg_overflow = true;
+ lo = int_const_binop (MINUS_EXPR, prod, tmp, 0);
+ hi = prod;
+ break;
- case CONST_DECL:
- return fold (DECL_INITIAL (t));
+ case 0:
+ lo = fold_negate_const (tmp, TREE_TYPE (arg0));
+ hi = tmp;
+ break;
- case NOP_EXPR:
- case FLOAT_EXPR:
- case CONVERT_EXPR:
- case FIX_TRUNC_EXPR:
- /* Other kinds of FIX are not handled properly by fold_convert. */
+ case 1:
+ hi = int_const_binop (PLUS_EXPR, prod, tmp, 0);
+ lo = prod;
+ break;
- if (TREE_TYPE (TREE_OPERAND (t, 0)) == TREE_TYPE (t))
- return TREE_OPERAND (t, 0);
+ default:
+ gcc_unreachable ();
+ }
+ }
+ else
+ {
+ /* A negative divisor reverses the relational operators. */
+ code = swap_tree_comparison (code);
- /* Handle cases of two conversions in a row. */
- if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
- || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
+ tmp = int_const_binop (PLUS_EXPR, arg01,
+ build_int_cst (TREE_TYPE (arg01), 1), 0);
+ switch (tree_int_cst_sgn (arg1))
{
- tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
- tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
- tree final_type = TREE_TYPE (t);
- int inside_int = INTEGRAL_TYPE_P (inside_type);
- int inside_ptr = POINTER_TYPE_P (inside_type);
- int inside_float = FLOAT_TYPE_P (inside_type);
- unsigned int inside_prec = TYPE_PRECISION (inside_type);
- int inside_unsignedp = TREE_UNSIGNED (inside_type);
- int inter_int = INTEGRAL_TYPE_P (inter_type);
- int inter_ptr = POINTER_TYPE_P (inter_type);
- int inter_float = FLOAT_TYPE_P (inter_type);
- unsigned int inter_prec = TYPE_PRECISION (inter_type);
- int inter_unsignedp = TREE_UNSIGNED (inter_type);
- int final_int = INTEGRAL_TYPE_P (final_type);
- int final_ptr = POINTER_TYPE_P (final_type);
- int final_float = FLOAT_TYPE_P (final_type);
- unsigned int final_prec = TYPE_PRECISION (final_type);
- int final_unsignedp = TREE_UNSIGNED (final_type);
+ case -1:
+ hi = int_const_binop (MINUS_EXPR, prod, tmp, 0);
+ lo = prod;
+ break;
- /* In addition to the cases of two conversions in a row
- handled below, if we are converting something to its own
- type via an object of identical or wider precision, neither
- conversion is needed. */
- if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (final_type)
- && ((inter_int && final_int) || (inter_float && final_float))
- && inter_prec >= final_prec)
- return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
-
- /* Likewise, if the intermediate and final types are either both
- float or both integer, we don't need the middle conversion if
- it is wider than the final type and doesn't change the signedness
- (for integers). Avoid this if the final type is a pointer
- since then we sometimes need the inner conversion. Likewise if
- the outer has a precision not equal to the size of its mode. */
- if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
- || (inter_float && inside_float))
- && inter_prec >= inside_prec
- && (inter_float || inter_unsignedp == inside_unsignedp)
- && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
- && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
- && ! final_ptr)
- return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
+ case 0:
+ hi = fold_negate_const (tmp, TREE_TYPE (arg0));
+ lo = tmp;
+ break;
- /* If we have a sign-extension of a zero-extended value, we can
- replace that by a single zero-extension. */
- if (inside_int && inter_int && final_int
- && inside_prec < inter_prec && inter_prec < final_prec
- && inside_unsignedp && !inter_unsignedp)
- return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
+ case 1:
+ neg_overflow = true;
+ lo = int_const_binop (PLUS_EXPR, prod, tmp, 0);
+ hi = prod;
+ break;
- /* Two conversions in a row are not needed unless:
- - some conversion is floating-point (overstrict for now), or
- - the intermediate type is narrower than both initial and
- final, or
- - the intermediate type and innermost type differ in signedness,
- and the outermost type is wider than the intermediate, or
- - the initial type is a pointer type and the precisions of the
- intermediate and final types differ, or
- - the final type is a pointer type and the precisions of the
- initial and intermediate types differ. */
- if (! inside_float && ! inter_float && ! final_float
- && (inter_prec > inside_prec || inter_prec > final_prec)
- && ! (inside_int && inter_int
- && inter_unsignedp != inside_unsignedp
- && inter_prec < final_prec)
- && ((inter_unsignedp && inter_prec > inside_prec)
- == (final_unsignedp && final_prec > inter_prec))
- && ! (inside_ptr && inter_prec != final_prec)
- && ! (final_ptr && inside_prec != inter_prec)
- && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
- && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
- && ! final_ptr)
- return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
+ default:
+ gcc_unreachable ();
}
+ }
- if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
- && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
- /* Detect assigning a bitfield. */
- && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
- && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
+ switch (code)
+ {
+ case EQ_EXPR:
+ if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
+ return omit_one_operand (type, integer_zero_node, arg00);
+ if (TREE_OVERFLOW (hi))
+ return fold_build2 (GE_EXPR, type, arg00, lo);
+ if (TREE_OVERFLOW (lo))
+ return fold_build2 (LE_EXPR, type, arg00, hi);
+ return build_range_check (type, arg00, 1, lo, hi);
+
+ case NE_EXPR:
+ if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
+ return omit_one_operand (type, integer_one_node, arg00);
+ if (TREE_OVERFLOW (hi))
+ return fold_build2 (LT_EXPR, type, arg00, lo);
+ if (TREE_OVERFLOW (lo))
+ return fold_build2 (GT_EXPR, type, arg00, hi);
+ return build_range_check (type, arg00, 0, lo, hi);
+
+ case LT_EXPR:
+ if (TREE_OVERFLOW (lo))
{
- /* Don't leave an assignment inside a conversion
- unless assigning a bitfield. */
- tree prev = TREE_OPERAND (t, 0);
- TREE_OPERAND (t, 0) = TREE_OPERAND (prev, 1);
- /* First do the assignment, then return converted constant. */
- t = build (COMPOUND_EXPR, TREE_TYPE (t), prev, fold (t));
- TREE_USED (t) = 1;
- return t;
+ tmp = neg_overflow ? integer_zero_node : integer_one_node;
+ return omit_one_operand (type, tmp, arg00);
}
- if (!wins)
+ return fold_build2 (LT_EXPR, type, arg00, lo);
+
+ case LE_EXPR:
+ if (TREE_OVERFLOW (hi))
{
- TREE_CONSTANT (t) = TREE_CONSTANT (arg0);
- return t;
+ tmp = neg_overflow ? integer_zero_node : integer_one_node;
+ return omit_one_operand (type, tmp, arg00);
}
- return fold_convert (t, arg0);
-
- case VIEW_CONVERT_EXPR:
- if (TREE_CODE (TREE_OPERAND (t, 0)) == VIEW_CONVERT_EXPR)
- return build1 (VIEW_CONVERT_EXPR, type,
- TREE_OPERAND (TREE_OPERAND (t, 0), 0));
- return t;
+ return fold_build2 (LE_EXPR, type, arg00, hi);
-#if 0 /* This loses on &"foo"[0]. */
- case ARRAY_REF:
+ case GT_EXPR:
+ if (TREE_OVERFLOW (hi))
{
- int i;
-
- /* Fold an expression like: "foo"[2] */
- if (TREE_CODE (arg0) == STRING_CST
- && TREE_CODE (arg1) == INTEGER_CST
- && compare_tree_int (arg1, TREE_STRING_LENGTH (arg0)) < 0)
- {
- t = build_int_2 (TREE_STRING_POINTER (arg0)[TREE_INT_CST_LOW (arg))], 0);
- TREE_TYPE (t) = TREE_TYPE (TREE_TYPE (arg0));
- force_fit_type (t, 0);
- }
+ tmp = neg_overflow ? integer_one_node : integer_zero_node;
+ return omit_one_operand (type, tmp, arg00);
}
- return t;
-#endif /* 0 */
+ return fold_build2 (GT_EXPR, type, arg00, hi);
- case COMPONENT_REF:
- if (TREE_CODE (arg0) == CONSTRUCTOR)
+ case GE_EXPR:
+ if (TREE_OVERFLOW (lo))
{
- tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
- if (m)
- t = TREE_VALUE (m);
+ tmp = neg_overflow ? integer_one_node : integer_zero_node;
+ return omit_one_operand (type, tmp, arg00);
}
- return t;
+ return fold_build2 (GE_EXPR, type, arg00, lo);
- case RANGE_EXPR:
- TREE_CONSTANT (t) = wins;
- return t;
+ default:
+ break;
+ }
- case NEGATE_EXPR:
- if (wins)
- {
- if (TREE_CODE (arg0) == INTEGER_CST)
- {
- unsigned HOST_WIDE_INT low;
- HOST_WIDE_INT high;
- int overflow = neg_double (TREE_INT_CST_LOW (arg0),
- TREE_INT_CST_HIGH (arg0),
- &low, &high);
- t = build_int_2 (low, high);
- TREE_TYPE (t) = type;
- TREE_OVERFLOW (t)
- = (TREE_OVERFLOW (arg0)
- | force_fit_type (t, overflow && !TREE_UNSIGNED (type)));
- TREE_CONSTANT_OVERFLOW (t)
- = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
- }
- else if (TREE_CODE (arg0) == REAL_CST)
- t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
- }
- else if (TREE_CODE (arg0) == NEGATE_EXPR)
- return TREE_OPERAND (arg0, 0);
+ return NULL_TREE;
+}
- /* Convert - (a - b) to (b - a) for non-floating-point. */
- else if (TREE_CODE (arg0) == MINUS_EXPR
- && (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
- return build (MINUS_EXPR, type, TREE_OPERAND (arg0, 1),
- TREE_OPERAND (arg0, 0));
- return t;
+/* If CODE with arguments ARG0 and ARG1 represents a single bit
+ equality/inequality test, then return a simplified form of the test
+ using a sign testing. Otherwise return NULL. TYPE is the desired
+ result type. */
- case ABS_EXPR:
- if (wins)
+static tree
+fold_single_bit_test_into_sign_test (enum tree_code code, tree arg0, tree arg1,
+ tree result_type)
+{
+ /* If this is testing a single bit, we can optimize the test. */
+ if ((code == NE_EXPR || code == EQ_EXPR)
+ && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
+ && integer_pow2p (TREE_OPERAND (arg0, 1)))
+ {
+ /* If we have (A & C) != 0 where C is the sign bit of A, convert
+ this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
+ tree arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
+
+ if (arg00 != NULL_TREE
+ /* This is only a win if casting to a signed type is cheap,
+ i.e. when arg00's type is not a partial mode. */
+ && TYPE_PRECISION (TREE_TYPE (arg00))
+ == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg00))))
{
- if (TREE_CODE (arg0) == INTEGER_CST)
- {
- /* If the value is unsigned, then the absolute value is
- the same as the ordinary value. */
- if (TREE_UNSIGNED (type))
- return arg0;
- /* Similarly, if the value is non-negative. */
- else if (INT_CST_LT (integer_minus_one_node, arg0))
- return arg0;
- /* If the value is negative, then the absolute value is
- its negation. */
- else
- {
- unsigned HOST_WIDE_INT low;
- HOST_WIDE_INT high;
- int overflow = neg_double (TREE_INT_CST_LOW (arg0),
- TREE_INT_CST_HIGH (arg0),
- &low, &high);
- t = build_int_2 (low, high);
- TREE_TYPE (t) = type;
- TREE_OVERFLOW (t)
- = (TREE_OVERFLOW (arg0)
- | force_fit_type (t, overflow));
- TREE_CONSTANT_OVERFLOW (t)
- = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
- }
- }
- else if (TREE_CODE (arg0) == REAL_CST)
- {
- if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
- t = build_real (type,
- REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
- }
+ tree stype = signed_type_for (TREE_TYPE (arg00));
+ return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
+ result_type, fold_convert (stype, arg00),
+ build_int_cst (stype, 0));
}
- else if (TREE_CODE (arg0) == ABS_EXPR || TREE_CODE (arg0) == NEGATE_EXPR)
- return build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
- return t;
+ }
- case CONJ_EXPR:
- if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
- return convert (type, arg0);
- else if (TREE_CODE (arg0) == COMPLEX_EXPR)
- return build (COMPLEX_EXPR, type,
- TREE_OPERAND (arg0, 0),
- negate_expr (TREE_OPERAND (arg0, 1)));
- else if (TREE_CODE (arg0) == COMPLEX_CST)
- return build_complex (type, TREE_REALPART (arg0),
- negate_expr (TREE_IMAGPART (arg0)));
- else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
- return fold (build (TREE_CODE (arg0), type,
- fold (build1 (CONJ_EXPR, type,
- TREE_OPERAND (arg0, 0))),
- fold (build1 (CONJ_EXPR,
- type, TREE_OPERAND (arg0, 1)))));
- else if (TREE_CODE (arg0) == CONJ_EXPR)
- return TREE_OPERAND (arg0, 0);
- return t;
+ return NULL_TREE;
+}
- case BIT_NOT_EXPR:
- if (wins)
+/* If CODE with arguments ARG0 and ARG1 represents a single bit
+ equality/inequality test, then return a simplified form of
+ the test using shifts and logical operations. Otherwise return
+ NULL. TYPE is the desired result type. */
+
+tree
+fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
+ tree result_type)
+{
+ /* If this is testing a single bit, we can optimize the test. */
+ if ((code == NE_EXPR || code == EQ_EXPR)
+ && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
+ && integer_pow2p (TREE_OPERAND (arg0, 1)))
+ {
+ tree inner = TREE_OPERAND (arg0, 0);
+ tree type = TREE_TYPE (arg0);
+ int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
+ enum machine_mode operand_mode = TYPE_MODE (type);
+ int ops_unsigned;
+ tree signed_type, unsigned_type, intermediate_type;
+ tree tem, one;
+
+ /* First, see if we can fold the single bit test into a sign-bit
+ test. */
+ tem = fold_single_bit_test_into_sign_test (code, arg0, arg1,
+ result_type);
+ if (tem)
+ return tem;
+
+ /* Otherwise we have (A & C) != 0 where C is a single bit,
+ convert that into ((A >> C2) & 1). Where C2 = log2(C).
+ Similarly for (A & C) == 0. */
+
+ /* If INNER is a right shift of a constant and it plus BITNUM does
+ not overflow, adjust BITNUM and INNER. */
+ if (TREE_CODE (inner) == RSHIFT_EXPR
+ && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
+ && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
+ && bitnum < TYPE_PRECISION (type)
+ && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
+ bitnum - TYPE_PRECISION (type)))
{
- t = build_int_2 (~ TREE_INT_CST_LOW (arg0),
- ~ TREE_INT_CST_HIGH (arg0));
- TREE_TYPE (t) = type;
- force_fit_type (t, 0);
- TREE_OVERFLOW (t) = TREE_OVERFLOW (arg0);
- TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (arg0);
+ bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
+ inner = TREE_OPERAND (inner, 0);
}
- else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
- return TREE_OPERAND (arg0, 0);
- return t;
- case PLUS_EXPR:
- /* A + (-B) -> A - B */
- if (TREE_CODE (arg1) == NEGATE_EXPR)
- return fold (build (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
- /* (-A) + B -> B - A */
- if (TREE_CODE (arg0) == NEGATE_EXPR)
- return fold (build (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
- else if (! FLOAT_TYPE_P (type))
- {
- if (integer_zerop (arg1))
- return non_lvalue (convert (type, arg0));
+ /* If we are going to be able to omit the AND below, we must do our
+ operations as unsigned. If we must use the AND, we have a choice.
+ Normally unsigned is faster, but for some machines signed is. */
+#ifdef LOAD_EXTEND_OP
+ ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND
+ && !flag_syntax_only) ? 0 : 1;
+#else
+ ops_unsigned = 1;
+#endif
- /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
- with a constant, and the two constants have no bits in common,
- we should treat this as a BIT_IOR_EXPR since this may produce more
- simplifications. */
- if (TREE_CODE (arg0) == BIT_AND_EXPR
- && TREE_CODE (arg1) == BIT_AND_EXPR
- && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
- && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
- && integer_zerop (const_binop (BIT_AND_EXPR,
- TREE_OPERAND (arg0, 1),
- TREE_OPERAND (arg1, 1), 0)))
- {
- code = BIT_IOR_EXPR;
- goto bit_ior;
- }
+ signed_type = lang_hooks.types.type_for_mode (operand_mode, 0);
+ unsigned_type = lang_hooks.types.type_for_mode (operand_mode, 1);
+ intermediate_type = ops_unsigned ? unsigned_type : signed_type;
+ inner = fold_convert (intermediate_type, inner);
- /* Reassociate (plus (plus (mult) (foo)) (mult)) as
- (plus (plus (mult) (mult)) (foo)) so that we can
- take advantage of the factoring cases below. */
- if ((TREE_CODE (arg0) == PLUS_EXPR
+ if (bitnum != 0)
+ inner = build2 (RSHIFT_EXPR, intermediate_type,
+ inner, size_int (bitnum));
+
+ one = build_int_cst (intermediate_type, 1);
+
+ if (code == EQ_EXPR)
+ inner = fold_build2 (BIT_XOR_EXPR, intermediate_type, inner, one);
+
+ /* Put the AND last so it can combine with more things. */
+ inner = build2 (BIT_AND_EXPR, intermediate_type, inner, one);
+
+ /* Make sure to return the proper type. */
+ inner = fold_convert (result_type, inner);
+
+ return inner;
+ }
+ return NULL_TREE;
+}
+
+/* Check whether we are allowed to reorder operands arg0 and arg1,
+ such that the evaluation of arg1 occurs before arg0. */
+
+static bool
+reorder_operands_p (const_tree arg0, const_tree arg1)
+{
+ if (! flag_evaluation_order)
+ return true;
+ if (TREE_CONSTANT (arg0) || TREE_CONSTANT (arg1))
+ return true;
+ return ! TREE_SIDE_EFFECTS (arg0)
+ && ! TREE_SIDE_EFFECTS (arg1);
+}
+
+/* Test whether it is preferable two swap two operands, ARG0 and
+ ARG1, for example because ARG0 is an integer constant and ARG1
+ isn't. If REORDER is true, only recommend swapping if we can
+ evaluate the operands in reverse order. */
+
+bool
+tree_swap_operands_p (const_tree arg0, const_tree arg1, bool reorder)
+{
+ STRIP_SIGN_NOPS (arg0);
+ STRIP_SIGN_NOPS (arg1);
+
+ if (TREE_CODE (arg1) == INTEGER_CST)
+ return 0;
+ if (TREE_CODE (arg0) == INTEGER_CST)
+ return 1;
+
+ if (TREE_CODE (arg1) == REAL_CST)
+ return 0;
+ if (TREE_CODE (arg0) == REAL_CST)
+ return 1;
+
+ if (TREE_CODE (arg1) == FIXED_CST)
+ return 0;
+ if (TREE_CODE (arg0) == FIXED_CST)
+ return 1;
+
+ if (TREE_CODE (arg1) == COMPLEX_CST)
+ return 0;
+ if (TREE_CODE (arg0) == COMPLEX_CST)
+ return 1;
+
+ if (TREE_CONSTANT (arg1))
+ return 0;
+ if (TREE_CONSTANT (arg0))
+ return 1;
+
+ if (optimize_function_for_size_p (cfun))
+ return 0;
+
+ if (reorder && flag_evaluation_order
+ && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
+ return 0;
+
+ /* It is preferable to swap two SSA_NAME to ensure a canonical form
+ for commutative and comparison operators. Ensuring a canonical
+ form allows the optimizers to find additional redundancies without
+ having to explicitly check for both orderings. */
+ if (TREE_CODE (arg0) == SSA_NAME
+ && TREE_CODE (arg1) == SSA_NAME
+ && SSA_NAME_VERSION (arg0) > SSA_NAME_VERSION (arg1))
+ return 1;
+
+ /* Put SSA_NAMEs last. */
+ if (TREE_CODE (arg1) == SSA_NAME)
+ return 0;
+ if (TREE_CODE (arg0) == SSA_NAME)
+ return 1;
+
+ /* Put variables last. */
+ if (DECL_P (arg1))
+ return 0;
+ if (DECL_P (arg0))
+ return 1;
+
+ return 0;
+}
+
+/* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where
+ ARG0 is extended to a wider type. */
+
+static tree
+fold_widened_comparison (enum tree_code code, tree type, tree arg0, tree arg1)
+{
+ tree arg0_unw = get_unwidened (arg0, NULL_TREE);
+ tree arg1_unw;
+ tree shorter_type, outer_type;
+ tree min, max;
+ bool above, below;
+
+ if (arg0_unw == arg0)
+ return NULL_TREE;
+ shorter_type = TREE_TYPE (arg0_unw);
+
+#ifdef HAVE_canonicalize_funcptr_for_compare
+ /* Disable this optimization if we're casting a function pointer
+ type on targets that require function pointer canonicalization. */
+ if (HAVE_canonicalize_funcptr_for_compare
+ && TREE_CODE (shorter_type) == POINTER_TYPE
+ && TREE_CODE (TREE_TYPE (shorter_type)) == FUNCTION_TYPE)
+ return NULL_TREE;
+#endif
+
+ if (TYPE_PRECISION (TREE_TYPE (arg0)) <= TYPE_PRECISION (shorter_type))
+ return NULL_TREE;
+
+ arg1_unw = get_unwidened (arg1, NULL_TREE);
+
+ /* If possible, express the comparison in the shorter mode. */
+ if ((code == EQ_EXPR || code == NE_EXPR
+ || TYPE_UNSIGNED (TREE_TYPE (arg0)) == TYPE_UNSIGNED (shorter_type))
+ && (TREE_TYPE (arg1_unw) == shorter_type
+ || ((TYPE_PRECISION (shorter_type)
+ >= TYPE_PRECISION (TREE_TYPE (arg1_unw)))
+ && (TYPE_UNSIGNED (shorter_type)
+ == TYPE_UNSIGNED (TREE_TYPE (arg1_unw))))
+ || (TREE_CODE (arg1_unw) == INTEGER_CST
+ && (TREE_CODE (shorter_type) == INTEGER_TYPE
+ || TREE_CODE (shorter_type) == BOOLEAN_TYPE)
+ && int_fits_type_p (arg1_unw, shorter_type))))
+ return fold_build2 (code, type, arg0_unw,
+ fold_convert (shorter_type, arg1_unw));
+
+ if (TREE_CODE (arg1_unw) != INTEGER_CST
+ || TREE_CODE (shorter_type) != INTEGER_TYPE
+ || !int_fits_type_p (arg1_unw, shorter_type))
+ return NULL_TREE;
+
+ /* If we are comparing with the integer that does not fit into the range
+ of the shorter type, the result is known. */
+ outer_type = TREE_TYPE (arg1_unw);
+ min = lower_bound_in_type (outer_type, shorter_type);
+ max = upper_bound_in_type (outer_type, shorter_type);
+
+ above = integer_nonzerop (fold_relational_const (LT_EXPR, type,
+ max, arg1_unw));
+ below = integer_nonzerop (fold_relational_const (LT_EXPR, type,
+ arg1_unw, min));
+
+ switch (code)
+ {
+ case EQ_EXPR:
+ if (above || below)
+ return omit_one_operand (type, integer_zero_node, arg0);
+ break;
+
+ case NE_EXPR:
+ if (above || below)
+ return omit_one_operand (type, integer_one_node, arg0);
+ break;
+
+ case LT_EXPR:
+ case LE_EXPR:
+ if (above)
+ return omit_one_operand (type, integer_one_node, arg0);
+ else if (below)
+ return omit_one_operand (type, integer_zero_node, arg0);
+
+ case GT_EXPR:
+ case GE_EXPR:
+ if (above)
+ return omit_one_operand (type, integer_zero_node, arg0);
+ else if (below)
+ return omit_one_operand (type, integer_one_node, arg0);
+
+ default:
+ break;
+ }
+
+ return NULL_TREE;
+}
+
+/* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where for
+ ARG0 just the signedness is changed. */
+
+static tree
+fold_sign_changed_comparison (enum tree_code code, tree type,
+ tree arg0, tree arg1)
+{
+ tree arg0_inner;
+ tree inner_type, outer_type;
+
+ if (!CONVERT_EXPR_P (arg0))
+ return NULL_TREE;
+
+ outer_type = TREE_TYPE (arg0);
+ arg0_inner = TREE_OPERAND (arg0, 0);
+ inner_type = TREE_TYPE (arg0_inner);
+
+#ifdef HAVE_canonicalize_funcptr_for_compare
+ /* Disable this optimization if we're casting a function pointer
+ type on targets that require function pointer canonicalization. */
+ if (HAVE_canonicalize_funcptr_for_compare
+ && TREE_CODE (inner_type) == POINTER_TYPE
+ && TREE_CODE (TREE_TYPE (inner_type)) == FUNCTION_TYPE)
+ return NULL_TREE;
+#endif
+
+ if (TYPE_PRECISION (inner_type) != TYPE_PRECISION (outer_type))
+ return NULL_TREE;
+
+ /* If the conversion is from an integral subtype to its basetype
+ leave it alone. */
+ if (TREE_TYPE (inner_type) == outer_type)
+ return NULL_TREE;
+
+ if (TREE_CODE (arg1) != INTEGER_CST
+ && !(CONVERT_EXPR_P (arg1)
+ && TREE_TYPE (TREE_OPERAND (arg1, 0)) == inner_type))
+ return NULL_TREE;
+
+ if ((TYPE_UNSIGNED (inner_type) != TYPE_UNSIGNED (outer_type)
+ || POINTER_TYPE_P (inner_type) != POINTER_TYPE_P (outer_type))
+ && code != NE_EXPR
+ && code != EQ_EXPR)
+ return NULL_TREE;
+
+ if (TREE_CODE (arg1) == INTEGER_CST)
+ arg1 = force_fit_type_double (inner_type, TREE_INT_CST_LOW (arg1),
+ TREE_INT_CST_HIGH (arg1), 0,
+ TREE_OVERFLOW (arg1));
+ else
+ arg1 = fold_convert (inner_type, arg1);
+
+ return fold_build2 (code, type, arg0_inner, arg1);
+}
+
+/* Tries to replace &a[idx] p+ s * delta with &a[idx + delta], if s is
+ step of the array. Reconstructs s and delta in the case of s * delta
+ being an integer constant (and thus already folded).
+ ADDR is the address. MULT is the multiplicative expression.
+ If the function succeeds, the new address expression is returned. Otherwise
+ NULL_TREE is returned. */
+
+static tree
+try_move_mult_to_index (tree addr, tree op1)
+{
+ tree s, delta, step;
+ tree ref = TREE_OPERAND (addr, 0), pref;
+ tree ret, pos;
+ tree itype;
+ bool mdim = false;
+
+ /* Strip the nops that might be added when converting op1 to sizetype. */
+ STRIP_NOPS (op1);
+
+ /* Canonicalize op1 into a possibly non-constant delta
+ and an INTEGER_CST s. */
+ if (TREE_CODE (op1) == MULT_EXPR)
+ {
+ tree arg0 = TREE_OPERAND (op1, 0), arg1 = TREE_OPERAND (op1, 1);
+
+ STRIP_NOPS (arg0);
+ STRIP_NOPS (arg1);
+
+ if (TREE_CODE (arg0) == INTEGER_CST)
+ {
+ s = arg0;
+ delta = arg1;
+ }
+ else if (TREE_CODE (arg1) == INTEGER_CST)
+ {
+ s = arg1;
+ delta = arg0;
+ }
+ else
+ return NULL_TREE;
+ }
+ else if (TREE_CODE (op1) == INTEGER_CST)
+ {
+ delta = op1;
+ s = NULL_TREE;
+ }
+ else
+ {
+ /* Simulate we are delta * 1. */
+ delta = op1;
+ s = integer_one_node;
+ }
+
+ for (;; ref = TREE_OPERAND (ref, 0))
+ {
+ if (TREE_CODE (ref) == ARRAY_REF)
+ {
+ /* Remember if this was a multi-dimensional array. */
+ if (TREE_CODE (TREE_OPERAND (ref, 0)) == ARRAY_REF)
+ mdim = true;
+
+ itype = TYPE_DOMAIN (TREE_TYPE (TREE_OPERAND (ref, 0)));
+ if (! itype)
+ continue;
+
+ step = array_ref_element_size (ref);
+ if (TREE_CODE (step) != INTEGER_CST)
+ continue;
+
+ if (s)
+ {
+ if (! tree_int_cst_equal (step, s))
+ continue;
+ }
+ else
+ {
+ /* Try if delta is a multiple of step. */
+ tree tmp = div_if_zero_remainder (EXACT_DIV_EXPR, op1, step);
+ if (! tmp)
+ continue;
+ delta = tmp;
+ }
+
+ /* Only fold here if we can verify we do not overflow one
+ dimension of a multi-dimensional array. */
+ if (mdim)
+ {
+ tree tmp;
+
+ if (TREE_CODE (TREE_OPERAND (ref, 1)) != INTEGER_CST
+ || !INTEGRAL_TYPE_P (itype)
+ || !TYPE_MAX_VALUE (itype)
+ || TREE_CODE (TYPE_MAX_VALUE (itype)) != INTEGER_CST)
+ continue;
+
+ tmp = fold_binary (PLUS_EXPR, itype,
+ fold_convert (itype,
+ TREE_OPERAND (ref, 1)),
+ fold_convert (itype, delta));
+ if (!tmp
+ || TREE_CODE (tmp) != INTEGER_CST
+ || tree_int_cst_lt (TYPE_MAX_VALUE (itype), tmp))
+ continue;
+ }
+
+ break;
+ }
+ else
+ mdim = false;
+
+ if (!handled_component_p (ref))
+ return NULL_TREE;
+ }
+
+ /* We found the suitable array reference. So copy everything up to it,
+ and replace the index. */
+
+ pref = TREE_OPERAND (addr, 0);
+ ret = copy_node (pref);
+ pos = ret;
+
+ while (pref != ref)
+ {
+ pref = TREE_OPERAND (pref, 0);
+ TREE_OPERAND (pos, 0) = copy_node (pref);
+ pos = TREE_OPERAND (pos, 0);
+ }
+
+ TREE_OPERAND (pos, 1) = fold_build2 (PLUS_EXPR, itype,
+ fold_convert (itype,
+ TREE_OPERAND (pos, 1)),
+ fold_convert (itype, delta));
+
+ return fold_build1 (ADDR_EXPR, TREE_TYPE (addr), ret);
+}
+
+
+/* Fold A < X && A + 1 > Y to A < X && A >= Y. Normally A + 1 > Y
+ means A >= Y && A != MAX, but in this case we know that
+ A < X <= MAX. INEQ is A + 1 > Y, BOUND is A < X. */
+
+static tree
+fold_to_nonsharp_ineq_using_bound (tree ineq, tree bound)
+{
+ tree a, typea, type = TREE_TYPE (ineq), a1, diff, y;
+
+ if (TREE_CODE (bound) == LT_EXPR)
+ a = TREE_OPERAND (bound, 0);
+ else if (TREE_CODE (bound) == GT_EXPR)
+ a = TREE_OPERAND (bound, 1);
+ else
+ return NULL_TREE;
+
+ typea = TREE_TYPE (a);
+ if (!INTEGRAL_TYPE_P (typea)
+ && !POINTER_TYPE_P (typea))
+ return NULL_TREE;
+
+ if (TREE_CODE (ineq) == LT_EXPR)
+ {
+ a1 = TREE_OPERAND (ineq, 1);
+ y = TREE_OPERAND (ineq, 0);
+ }
+ else if (TREE_CODE (ineq) == GT_EXPR)
+ {
+ a1 = TREE_OPERAND (ineq, 0);
+ y = TREE_OPERAND (ineq, 1);
+ }
+ else
+ return NULL_TREE;
+
+ if (TREE_TYPE (a1) != typea)
+ return NULL_TREE;
+
+ if (POINTER_TYPE_P (typea))
+ {
+ /* Convert the pointer types into integer before taking the difference. */
+ tree ta = fold_convert (ssizetype, a);
+ tree ta1 = fold_convert (ssizetype, a1);
+ diff = fold_binary (MINUS_EXPR, ssizetype, ta1, ta);
+ }
+ else
+ diff = fold_binary (MINUS_EXPR, typea, a1, a);
+
+ if (!diff || !integer_onep (diff))
+ return NULL_TREE;
+
+ return fold_build2 (GE_EXPR, type, a, y);
+}
+
+/* Fold a sum or difference of at least one multiplication.
+ Returns the folded tree or NULL if no simplification could be made. */
+
+static tree
+fold_plusminus_mult_expr (enum tree_code code, tree type, tree arg0, tree arg1)
+{
+ tree arg00, arg01, arg10, arg11;
+ tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
+
+ /* (A * C) +- (B * C) -> (A+-B) * C.
+ (A * C) +- A -> A * (C+-1).
+ We are most concerned about the case where C is a constant,
+ but other combinations show up during loop reduction. Since
+ it is not difficult, try all four possibilities. */
+
+ if (TREE_CODE (arg0) == MULT_EXPR)
+ {
+ arg00 = TREE_OPERAND (arg0, 0);
+ arg01 = TREE_OPERAND (arg0, 1);
+ }
+ else if (TREE_CODE (arg0) == INTEGER_CST)
+ {
+ arg00 = build_one_cst (type);
+ arg01 = arg0;
+ }
+ else
+ {
+ /* We cannot generate constant 1 for fract. */
+ if (ALL_FRACT_MODE_P (TYPE_MODE (type)))
+ return NULL_TREE;
+ arg00 = arg0;
+ arg01 = build_one_cst (type);
+ }
+ if (TREE_CODE (arg1) == MULT_EXPR)
+ {
+ arg10 = TREE_OPERAND (arg1, 0);
+ arg11 = TREE_OPERAND (arg1, 1);
+ }
+ else if (TREE_CODE (arg1) == INTEGER_CST)
+ {
+ arg10 = build_one_cst (type);
+ /* As we canonicalize A - 2 to A + -2 get rid of that sign for
+ the purpose of this canonicalization. */
+ if (TREE_INT_CST_HIGH (arg1) == -1
+ && negate_expr_p (arg1)
+ && code == PLUS_EXPR)
+ {
+ arg11 = negate_expr (arg1);
+ code = MINUS_EXPR;
+ }
+ else
+ arg11 = arg1;
+ }
+ else
+ {
+ /* We cannot generate constant 1 for fract. */
+ if (ALL_FRACT_MODE_P (TYPE_MODE (type)))
+ return NULL_TREE;
+ arg10 = arg1;
+ arg11 = build_one_cst (type);
+ }
+ same = NULL_TREE;
+
+ if (operand_equal_p (arg01, arg11, 0))
+ same = arg01, alt0 = arg00, alt1 = arg10;
+ else if (operand_equal_p (arg00, arg10, 0))
+ same = arg00, alt0 = arg01, alt1 = arg11;
+ else if (operand_equal_p (arg00, arg11, 0))
+ same = arg00, alt0 = arg01, alt1 = arg10;
+ else if (operand_equal_p (arg01, arg10, 0))
+ same = arg01, alt0 = arg00, alt1 = arg11;
+
+ /* No identical multiplicands; see if we can find a common
+ power-of-two factor in non-power-of-two multiplies. This
+ can help in multi-dimensional array access. */
+ else if (host_integerp (arg01, 0)
+ && host_integerp (arg11, 0))
+ {
+ HOST_WIDE_INT int01, int11, tmp;
+ bool swap = false;
+ tree maybe_same;
+ int01 = TREE_INT_CST_LOW (arg01);
+ int11 = TREE_INT_CST_LOW (arg11);
+
+ /* Move min of absolute values to int11. */
+ if ((int01 >= 0 ? int01 : -int01)
+ < (int11 >= 0 ? int11 : -int11))
+ {
+ tmp = int01, int01 = int11, int11 = tmp;
+ alt0 = arg00, arg00 = arg10, arg10 = alt0;
+ maybe_same = arg01;
+ swap = true;
+ }
+ else
+ maybe_same = arg11;
+
+ if (exact_log2 (abs (int11)) > 0 && int01 % int11 == 0)
+ {
+ alt0 = fold_build2 (MULT_EXPR, TREE_TYPE (arg00), arg00,
+ build_int_cst (TREE_TYPE (arg00),
+ int01 / int11));
+ alt1 = arg10;
+ same = maybe_same;
+ if (swap)
+ maybe_same = alt0, alt0 = alt1, alt1 = maybe_same;
+ }
+ }
+
+ if (same)
+ return fold_build2 (MULT_EXPR, type,
+ fold_build2 (code, type,
+ fold_convert (type, alt0),
+ fold_convert (type, alt1)),
+ fold_convert (type, same));
+
+ return NULL_TREE;
+}
+
+/* Subroutine of native_encode_expr. Encode the INTEGER_CST
+ specified by EXPR into the buffer PTR of length LEN bytes.
+ Return the number of bytes placed in the buffer, or zero
+ upon failure. */
+
+static int
+native_encode_int (const_tree expr, unsigned char *ptr, int len)
+{
+ tree type = TREE_TYPE (expr);
+ int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
+ int byte, offset, word, words;
+ unsigned char value;
+
+ if (total_bytes > len)
+ return 0;
+ words = total_bytes / UNITS_PER_WORD;
+
+ for (byte = 0; byte < total_bytes; byte++)
+ {
+ int bitpos = byte * BITS_PER_UNIT;
+ if (bitpos < HOST_BITS_PER_WIDE_INT)
+ value = (unsigned char) (TREE_INT_CST_LOW (expr) >> bitpos);
+ else
+ value = (unsigned char) (TREE_INT_CST_HIGH (expr)
+ >> (bitpos - HOST_BITS_PER_WIDE_INT));
+
+ if (total_bytes > UNITS_PER_WORD)
+ {
+ word = byte / UNITS_PER_WORD;
+ if (WORDS_BIG_ENDIAN)
+ word = (words - 1) - word;
+ offset = word * UNITS_PER_WORD;
+ if (BYTES_BIG_ENDIAN)
+ offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
+ else
+ offset += byte % UNITS_PER_WORD;
+ }
+ else
+ offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
+ ptr[offset] = value;
+ }
+ return total_bytes;
+}
+
+
+/* Subroutine of native_encode_expr. Encode the REAL_CST
+ specified by EXPR into the buffer PTR of length LEN bytes.
+ Return the number of bytes placed in the buffer, or zero
+ upon failure. */
+
+static int
+native_encode_real (const_tree expr, unsigned char *ptr, int len)
+{
+ tree type = TREE_TYPE (expr);
+ int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
+ int byte, offset, word, words, bitpos;
+ unsigned char value;
+
+ /* There are always 32 bits in each long, no matter the size of
+ the hosts long. We handle floating point representations with
+ up to 192 bits. */
+ long tmp[6];
+
+ if (total_bytes > len)
+ return 0;
+ words = (32 / BITS_PER_UNIT) / UNITS_PER_WORD;
+
+ real_to_target (tmp, TREE_REAL_CST_PTR (expr), TYPE_MODE (type));
+
+ for (bitpos = 0; bitpos < total_bytes * BITS_PER_UNIT;
+ bitpos += BITS_PER_UNIT)
+ {
+ byte = (bitpos / BITS_PER_UNIT) & 3;
+ value = (unsigned char) (tmp[bitpos / 32] >> (bitpos & 31));
+
+ if (UNITS_PER_WORD < 4)
+ {
+ word = byte / UNITS_PER_WORD;
+ if (WORDS_BIG_ENDIAN)
+ word = (words - 1) - word;
+ offset = word * UNITS_PER_WORD;
+ if (BYTES_BIG_ENDIAN)
+ offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
+ else
+ offset += byte % UNITS_PER_WORD;
+ }
+ else
+ offset = BYTES_BIG_ENDIAN ? 3 - byte : byte;
+ ptr[offset + ((bitpos / BITS_PER_UNIT) & ~3)] = value;
+ }
+ return total_bytes;
+}
+
+/* Subroutine of native_encode_expr. Encode the COMPLEX_CST
+ specified by EXPR into the buffer PTR of length LEN bytes.
+ Return the number of bytes placed in the buffer, or zero
+ upon failure. */
+
+static int
+native_encode_complex (const_tree expr, unsigned char *ptr, int len)
+{
+ int rsize, isize;
+ tree part;
+
+ part = TREE_REALPART (expr);
+ rsize = native_encode_expr (part, ptr, len);
+ if (rsize == 0)
+ return 0;
+ part = TREE_IMAGPART (expr);
+ isize = native_encode_expr (part, ptr+rsize, len-rsize);
+ if (isize != rsize)
+ return 0;
+ return rsize + isize;
+}
+
+
+/* Subroutine of native_encode_expr. Encode the VECTOR_CST
+ specified by EXPR into the buffer PTR of length LEN bytes.
+ Return the number of bytes placed in the buffer, or zero
+ upon failure. */
+
+static int
+native_encode_vector (const_tree expr, unsigned char *ptr, int len)
+{
+ int i, size, offset, count;
+ tree itype, elem, elements;
+
+ offset = 0;
+ elements = TREE_VECTOR_CST_ELTS (expr);
+ count = TYPE_VECTOR_SUBPARTS (TREE_TYPE (expr));
+ itype = TREE_TYPE (TREE_TYPE (expr));
+ size = GET_MODE_SIZE (TYPE_MODE (itype));
+ for (i = 0; i < count; i++)
+ {
+ if (elements)
+ {
+ elem = TREE_VALUE (elements);
+ elements = TREE_CHAIN (elements);
+ }
+ else
+ elem = NULL_TREE;
+
+ if (elem)
+ {
+ if (native_encode_expr (elem, ptr+offset, len-offset) != size)
+ return 0;
+ }
+ else
+ {
+ if (offset + size > len)
+ return 0;
+ memset (ptr+offset, 0, size);
+ }
+ offset += size;
+ }
+ return offset;
+}
+
+
+/* Subroutine of native_encode_expr. Encode the STRING_CST
+ specified by EXPR into the buffer PTR of length LEN bytes.
+ Return the number of bytes placed in the buffer, or zero
+ upon failure. */
+
+static int
+native_encode_string (const_tree expr, unsigned char *ptr, int len)
+{
+ tree type = TREE_TYPE (expr);
+ HOST_WIDE_INT total_bytes;
+
+ if (TREE_CODE (type) != ARRAY_TYPE
+ || TREE_CODE (TREE_TYPE (type)) != INTEGER_TYPE
+ || GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (type))) != BITS_PER_UNIT
+ || !host_integerp (TYPE_SIZE_UNIT (type), 0))
+ return 0;
+ total_bytes = tree_low_cst (TYPE_SIZE_UNIT (type), 0);
+ if (total_bytes > len)
+ return 0;
+ if (TREE_STRING_LENGTH (expr) < total_bytes)
+ {
+ memcpy (ptr, TREE_STRING_POINTER (expr), TREE_STRING_LENGTH (expr));
+ memset (ptr + TREE_STRING_LENGTH (expr), 0,
+ total_bytes - TREE_STRING_LENGTH (expr));
+ }
+ else
+ memcpy (ptr, TREE_STRING_POINTER (expr), total_bytes);
+ return total_bytes;
+}
+
+
+/* Subroutine of fold_view_convert_expr. Encode the INTEGER_CST,
+ REAL_CST, COMPLEX_CST or VECTOR_CST specified by EXPR into the
+ buffer PTR of length LEN bytes. Return the number of bytes
+ placed in the buffer, or zero upon failure. */
+
+int
+native_encode_expr (const_tree expr, unsigned char *ptr, int len)
+{
+ switch (TREE_CODE (expr))
+ {
+ case INTEGER_CST:
+ return native_encode_int (expr, ptr, len);
+
+ case REAL_CST:
+ return native_encode_real (expr, ptr, len);
+
+ case COMPLEX_CST:
+ return native_encode_complex (expr, ptr, len);
+
+ case VECTOR_CST:
+ return native_encode_vector (expr, ptr, len);
+
+ case STRING_CST:
+ return native_encode_string (expr, ptr, len);
+
+ default:
+ return 0;
+ }
+}
+
+
+/* Subroutine of native_interpret_expr. Interpret the contents of
+ the buffer PTR of length LEN as an INTEGER_CST of type TYPE.
+ If the buffer cannot be interpreted, return NULL_TREE. */
+
+static tree
+native_interpret_int (tree type, const unsigned char *ptr, int len)
+{
+ int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
+ int byte, offset, word, words;
+ unsigned char value;
+ unsigned int HOST_WIDE_INT lo = 0;
+ HOST_WIDE_INT hi = 0;
+
+ if (total_bytes > len)
+ return NULL_TREE;
+ if (total_bytes * BITS_PER_UNIT > 2 * HOST_BITS_PER_WIDE_INT)
+ return NULL_TREE;
+ words = total_bytes / UNITS_PER_WORD;
+
+ for (byte = 0; byte < total_bytes; byte++)
+ {
+ int bitpos = byte * BITS_PER_UNIT;
+ if (total_bytes > UNITS_PER_WORD)
+ {
+ word = byte / UNITS_PER_WORD;
+ if (WORDS_BIG_ENDIAN)
+ word = (words - 1) - word;
+ offset = word * UNITS_PER_WORD;
+ if (BYTES_BIG_ENDIAN)
+ offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
+ else
+ offset += byte % UNITS_PER_WORD;
+ }
+ else
+ offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
+ value = ptr[offset];
+
+ if (bitpos < HOST_BITS_PER_WIDE_INT)
+ lo |= (unsigned HOST_WIDE_INT) value << bitpos;
+ else
+ hi |= (unsigned HOST_WIDE_INT) value
+ << (bitpos - HOST_BITS_PER_WIDE_INT);
+ }
+
+ return build_int_cst_wide_type (type, lo, hi);
+}
+
+
+/* Subroutine of native_interpret_expr. Interpret the contents of
+ the buffer PTR of length LEN as a REAL_CST of type TYPE.
+ If the buffer cannot be interpreted, return NULL_TREE. */
+
+static tree
+native_interpret_real (tree type, const unsigned char *ptr, int len)
+{
+ enum machine_mode mode = TYPE_MODE (type);
+ int total_bytes = GET_MODE_SIZE (mode);
+ int byte, offset, word, words, bitpos;
+ unsigned char value;
+ /* There are always 32 bits in each long, no matter the size of
+ the hosts long. We handle floating point representations with
+ up to 192 bits. */
+ REAL_VALUE_TYPE r;
+ long tmp[6];
+
+ total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
+ if (total_bytes > len || total_bytes > 24)
+ return NULL_TREE;
+ words = (32 / BITS_PER_UNIT) / UNITS_PER_WORD;
+
+ memset (tmp, 0, sizeof (tmp));
+ for (bitpos = 0; bitpos < total_bytes * BITS_PER_UNIT;
+ bitpos += BITS_PER_UNIT)
+ {
+ byte = (bitpos / BITS_PER_UNIT) & 3;
+ if (UNITS_PER_WORD < 4)
+ {
+ word = byte / UNITS_PER_WORD;
+ if (WORDS_BIG_ENDIAN)
+ word = (words - 1) - word;
+ offset = word * UNITS_PER_WORD;
+ if (BYTES_BIG_ENDIAN)
+ offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
+ else
+ offset += byte % UNITS_PER_WORD;
+ }
+ else
+ offset = BYTES_BIG_ENDIAN ? 3 - byte : byte;
+ value = ptr[offset + ((bitpos / BITS_PER_UNIT) & ~3)];
+
+ tmp[bitpos / 32] |= (unsigned long)value << (bitpos & 31);
+ }
+
+ real_from_target (&r, tmp, mode);
+ return build_real (type, r);
+}
+
+
+/* Subroutine of native_interpret_expr. Interpret the contents of
+ the buffer PTR of length LEN as a COMPLEX_CST of type TYPE.
+ If the buffer cannot be interpreted, return NULL_TREE. */
+
+static tree
+native_interpret_complex (tree type, const unsigned char *ptr, int len)
+{
+ tree etype, rpart, ipart;
+ int size;
+
+ etype = TREE_TYPE (type);
+ size = GET_MODE_SIZE (TYPE_MODE (etype));
+ if (size * 2 > len)
+ return NULL_TREE;
+ rpart = native_interpret_expr (etype, ptr, size);
+ if (!rpart)
+ return NULL_TREE;
+ ipart = native_interpret_expr (etype, ptr+size, size);
+ if (!ipart)
+ return NULL_TREE;
+ return build_complex (type, rpart, ipart);
+}
+
+
+/* Subroutine of native_interpret_expr. Interpret the contents of
+ the buffer PTR of length LEN as a VECTOR_CST of type TYPE.
+ If the buffer cannot be interpreted, return NULL_TREE. */
+
+static tree
+native_interpret_vector (tree type, const unsigned char *ptr, int len)
+{
+ tree etype, elem, elements;
+ int i, size, count;
+
+ etype = TREE_TYPE (type);
+ size = GET_MODE_SIZE (TYPE_MODE (etype));
+ count = TYPE_VECTOR_SUBPARTS (type);
+ if (size * count > len)
+ return NULL_TREE;
+
+ elements = NULL_TREE;
+ for (i = count - 1; i >= 0; i--)
+ {
+ elem = native_interpret_expr (etype, ptr+(i*size), size);
+ if (!elem)
+ return NULL_TREE;
+ elements = tree_cons (NULL_TREE, elem, elements);
+ }
+ return build_vector (type, elements);
+}
+
+
+/* Subroutine of fold_view_convert_expr. Interpret the contents of
+ the buffer PTR of length LEN as a constant of type TYPE. For
+ INTEGRAL_TYPE_P we return an INTEGER_CST, for SCALAR_FLOAT_TYPE_P
+ we return a REAL_CST, etc... If the buffer cannot be interpreted,
+ return NULL_TREE. */
+
+tree
+native_interpret_expr (tree type, const unsigned char *ptr, int len)
+{
+ switch (TREE_CODE (type))
+ {
+ case INTEGER_TYPE:
+ case ENUMERAL_TYPE:
+ case BOOLEAN_TYPE:
+ return native_interpret_int (type, ptr, len);
+
+ case REAL_TYPE:
+ return native_interpret_real (type, ptr, len);
+
+ case COMPLEX_TYPE:
+ return native_interpret_complex (type, ptr, len);
+
+ case VECTOR_TYPE:
+ return native_interpret_vector (type, ptr, len);
+
+ default:
+ return NULL_TREE;
+ }
+}
+
+
+/* Fold a VIEW_CONVERT_EXPR of a constant expression EXPR to type
+ TYPE at compile-time. If we're unable to perform the conversion
+ return NULL_TREE. */
+
+static tree
+fold_view_convert_expr (tree type, tree expr)
+{
+ /* We support up to 512-bit values (for V8DFmode). */
+ unsigned char buffer[64];
+ int len;
+
+ /* Check that the host and target are sane. */
+ if (CHAR_BIT != 8 || BITS_PER_UNIT != 8)
+ return NULL_TREE;
+
+ len = native_encode_expr (expr, buffer, sizeof (buffer));
+ if (len == 0)
+ return NULL_TREE;
+
+ return native_interpret_expr (type, buffer, len);
+}
+
+/* Build an expression for the address of T. Folds away INDIRECT_REF
+ to avoid confusing the gimplify process. When IN_FOLD is true
+ avoid modifications of T. */
+
+static tree
+build_fold_addr_expr_with_type_1 (tree t, tree ptrtype, bool in_fold)
+{
+ /* The size of the object is not relevant when talking about its address. */
+ if (TREE_CODE (t) == WITH_SIZE_EXPR)
+ t = TREE_OPERAND (t, 0);
+
+ /* Note: doesn't apply to ALIGN_INDIRECT_REF */
+ if (TREE_CODE (t) == INDIRECT_REF
+ || TREE_CODE (t) == MISALIGNED_INDIRECT_REF)
+ {
+ t = TREE_OPERAND (t, 0);
+
+ if (TREE_TYPE (t) != ptrtype)
+ t = build1 (NOP_EXPR, ptrtype, t);
+ }
+ else if (!in_fold)
+ {
+ tree base = t;
+
+ while (handled_component_p (base))
+ base = TREE_OPERAND (base, 0);
+
+ if (DECL_P (base))
+ TREE_ADDRESSABLE (base) = 1;
+
+ t = build1 (ADDR_EXPR, ptrtype, t);
+ }
+ else
+ t = build1 (ADDR_EXPR, ptrtype, t);
+
+ return t;
+}
+
+/* Build an expression for the address of T with type PTRTYPE. This
+ function modifies the input parameter 'T' by sometimes setting the
+ TREE_ADDRESSABLE flag. */
+
+tree
+build_fold_addr_expr_with_type (tree t, tree ptrtype)
+{
+ return build_fold_addr_expr_with_type_1 (t, ptrtype, false);
+}
+
+/* Build an expression for the address of T. This function modifies
+ the input parameter 'T' by sometimes setting the TREE_ADDRESSABLE
+ flag. When called from fold functions, use fold_addr_expr instead. */
+
+tree
+build_fold_addr_expr (tree t)
+{
+ return build_fold_addr_expr_with_type_1 (t,
+ build_pointer_type (TREE_TYPE (t)),
+ false);
+}
+
+/* Same as build_fold_addr_expr, builds an expression for the address
+ of T, but avoids touching the input node 't'. Fold functions
+ should use this version. */
+
+static tree
+fold_addr_expr (tree t)
+{
+ tree ptrtype = build_pointer_type (TREE_TYPE (t));
+
+ return build_fold_addr_expr_with_type_1 (t, ptrtype, true);
+}
+
+/* Fold a unary expression of code CODE and type TYPE with operand
+ OP0. Return the folded expression if folding is successful.
+ Otherwise, return NULL_TREE. */
+
+tree
+fold_unary (enum tree_code code, tree type, tree op0)
+{
+ tree tem;
+ tree arg0;
+ enum tree_code_class kind = TREE_CODE_CLASS (code);
+
+ gcc_assert (IS_EXPR_CODE_CLASS (kind)
+ && TREE_CODE_LENGTH (code) == 1);
+
+ arg0 = op0;
+ if (arg0)
+ {
+ if (CONVERT_EXPR_CODE_P (code)
+ || code == FLOAT_EXPR || code == ABS_EXPR)
+ {
+ /* Don't use STRIP_NOPS, because signedness of argument type
+ matters. */
+ STRIP_SIGN_NOPS (arg0);
+ }
+ else
+ {
+ /* Strip any conversions that don't change the mode. This
+ is safe for every expression, except for a comparison
+ expression because its signedness is derived from its
+ operands.
+
+ Note that this is done as an internal manipulation within
+ the constant folder, in order to find the simplest
+ representation of the arguments so that their form can be
+ studied. In any cases, the appropriate type conversions
+ should be put back in the tree that will get out of the
+ constant folder. */
+ STRIP_NOPS (arg0);
+ }
+ }
+
+ if (TREE_CODE_CLASS (code) == tcc_unary)
+ {
+ if (TREE_CODE (arg0) == COMPOUND_EXPR)
+ return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
+ fold_build1 (code, type,
+ fold_convert (TREE_TYPE (op0),
+ TREE_OPERAND (arg0, 1))));
+ else if (TREE_CODE (arg0) == COND_EXPR)
+ {
+ tree arg01 = TREE_OPERAND (arg0, 1);
+ tree arg02 = TREE_OPERAND (arg0, 2);
+ if (! VOID_TYPE_P (TREE_TYPE (arg01)))
+ arg01 = fold_build1 (code, type,
+ fold_convert (TREE_TYPE (op0), arg01));
+ if (! VOID_TYPE_P (TREE_TYPE (arg02)))
+ arg02 = fold_build1 (code, type,
+ fold_convert (TREE_TYPE (op0), arg02));
+ tem = fold_build3 (COND_EXPR, type, TREE_OPERAND (arg0, 0),
+ arg01, arg02);
+
+ /* If this was a conversion, and all we did was to move into
+ inside the COND_EXPR, bring it back out. But leave it if
+ it is a conversion from integer to integer and the
+ result precision is no wider than a word since such a
+ conversion is cheap and may be optimized away by combine,
+ while it couldn't if it were outside the COND_EXPR. Then return
+ so we don't get into an infinite recursion loop taking the
+ conversion out and then back in. */
+
+ if ((CONVERT_EXPR_CODE_P (code)
+ || code == NON_LVALUE_EXPR)
+ && TREE_CODE (tem) == COND_EXPR
+ && TREE_CODE (TREE_OPERAND (tem, 1)) == code
+ && TREE_CODE (TREE_OPERAND (tem, 2)) == code
+ && ! VOID_TYPE_P (TREE_OPERAND (tem, 1))
+ && ! VOID_TYPE_P (TREE_OPERAND (tem, 2))
+ && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))
+ == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 2), 0)))
+ && (! (INTEGRAL_TYPE_P (TREE_TYPE (tem))
+ && (INTEGRAL_TYPE_P
+ (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))))
+ && TYPE_PRECISION (TREE_TYPE (tem)) <= BITS_PER_WORD)
+ || flag_syntax_only))
+ tem = build1 (code, type,
+ build3 (COND_EXPR,
+ TREE_TYPE (TREE_OPERAND
+ (TREE_OPERAND (tem, 1), 0)),
+ TREE_OPERAND (tem, 0),
+ TREE_OPERAND (TREE_OPERAND (tem, 1), 0),
+ TREE_OPERAND (TREE_OPERAND (tem, 2), 0)));
+ return tem;
+ }
+ else if (COMPARISON_CLASS_P (arg0))
+ {
+ if (TREE_CODE (type) == BOOLEAN_TYPE)
+ {
+ arg0 = copy_node (arg0);
+ TREE_TYPE (arg0) = type;
+ return arg0;
+ }
+ else if (TREE_CODE (type) != INTEGER_TYPE)
+ return fold_build3 (COND_EXPR, type, arg0,
+ fold_build1 (code, type,
+ integer_one_node),
+ fold_build1 (code, type,
+ integer_zero_node));
+ }
+ }
+
+ switch (code)
+ {
+ case PAREN_EXPR:
+ /* Re-association barriers around constants and other re-association
+ barriers can be removed. */
+ if (CONSTANT_CLASS_P (op0)
+ || TREE_CODE (op0) == PAREN_EXPR)
+ return fold_convert (type, op0);
+ return NULL_TREE;
+
+ CASE_CONVERT:
+ case FLOAT_EXPR:
+ case FIX_TRUNC_EXPR:
+ if (TREE_TYPE (op0) == type)
+ return op0;
+
+ /* If we have (type) (a CMP b) and type is an integral type, return
+ new expression involving the new type. */
+ if (COMPARISON_CLASS_P (op0) && INTEGRAL_TYPE_P (type))
+ return fold_build2 (TREE_CODE (op0), type, TREE_OPERAND (op0, 0),
+ TREE_OPERAND (op0, 1));
+
+ /* Handle cases of two conversions in a row. */
+ if (CONVERT_EXPR_P (op0))
+ {
+ tree inside_type = TREE_TYPE (TREE_OPERAND (op0, 0));
+ tree inter_type = TREE_TYPE (op0);
+ int inside_int = INTEGRAL_TYPE_P (inside_type);
+ int inside_ptr = POINTER_TYPE_P (inside_type);
+ int inside_float = FLOAT_TYPE_P (inside_type);
+ int inside_vec = TREE_CODE (inside_type) == VECTOR_TYPE;
+ unsigned int inside_prec = TYPE_PRECISION (inside_type);
+ int inside_unsignedp = TYPE_UNSIGNED (inside_type);
+ int inter_int = INTEGRAL_TYPE_P (inter_type);
+ int inter_ptr = POINTER_TYPE_P (inter_type);
+ int inter_float = FLOAT_TYPE_P (inter_type);
+ int inter_vec = TREE_CODE (inter_type) == VECTOR_TYPE;
+ unsigned int inter_prec = TYPE_PRECISION (inter_type);
+ int inter_unsignedp = TYPE_UNSIGNED (inter_type);
+ int final_int = INTEGRAL_TYPE_P (type);
+ int final_ptr = POINTER_TYPE_P (type);
+ int final_float = FLOAT_TYPE_P (type);
+ int final_vec = TREE_CODE (type) == VECTOR_TYPE;
+ unsigned int final_prec = TYPE_PRECISION (type);
+ int final_unsignedp = TYPE_UNSIGNED (type);
+
+ /* In addition to the cases of two conversions in a row
+ handled below, if we are converting something to its own
+ type via an object of identical or wider precision, neither
+ conversion is needed. */
+ if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (type)
+ && (((inter_int || inter_ptr) && final_int)
+ || (inter_float && final_float))
+ && inter_prec >= final_prec)
+ return fold_build1 (code, type, TREE_OPERAND (op0, 0));
+
+ /* Likewise, if the intermediate and initial types are either both
+ float or both integer, we don't need the middle conversion if the
+ former is wider than the latter and doesn't change the signedness
+ (for integers). Avoid this if the final type is a pointer since
+ then we sometimes need the middle conversion. Likewise if the
+ final type has a precision not equal to the size of its mode. */
+ if (((inter_int && inside_int)
+ || (inter_float && inside_float)
+ || (inter_vec && inside_vec))
+ && inter_prec >= inside_prec
+ && (inter_float || inter_vec
+ || inter_unsignedp == inside_unsignedp)
+ && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
+ && TYPE_MODE (type) == TYPE_MODE (inter_type))
+ && ! final_ptr
+ && (! final_vec || inter_prec == inside_prec))
+ return fold_build1 (code, type, TREE_OPERAND (op0, 0));
+
+ /* If we have a sign-extension of a zero-extended value, we can
+ replace that by a single zero-extension. */
+ if (inside_int && inter_int && final_int
+ && inside_prec < inter_prec && inter_prec < final_prec
+ && inside_unsignedp && !inter_unsignedp)
+ return fold_build1 (code, type, TREE_OPERAND (op0, 0));
+
+ /* Two conversions in a row are not needed unless:
+ - some conversion is floating-point (overstrict for now), or
+ - some conversion is a vector (overstrict for now), or
+ - the intermediate type is narrower than both initial and
+ final, or
+ - the intermediate type and innermost type differ in signedness,
+ and the outermost type is wider than the intermediate, or
+ - the initial type is a pointer type and the precisions of the
+ intermediate and final types differ, or
+ - the final type is a pointer type and the precisions of the
+ initial and intermediate types differ. */
+ if (! inside_float && ! inter_float && ! final_float
+ && ! inside_vec && ! inter_vec && ! final_vec
+ && (inter_prec >= inside_prec || inter_prec >= final_prec)
+ && ! (inside_int && inter_int
+ && inter_unsignedp != inside_unsignedp
+ && inter_prec < final_prec)
+ && ((inter_unsignedp && inter_prec > inside_prec)
+ == (final_unsignedp && final_prec > inter_prec))
+ && ! (inside_ptr && inter_prec != final_prec)
+ && ! (final_ptr && inside_prec != inter_prec)
+ && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
+ && TYPE_MODE (type) == TYPE_MODE (inter_type)))
+ return fold_build1 (code, type, TREE_OPERAND (op0, 0));
+ }
+
+ /* Handle (T *)&A.B.C for A being of type T and B and C
+ living at offset zero. This occurs frequently in
+ C++ upcasting and then accessing the base. */
+ if (TREE_CODE (op0) == ADDR_EXPR
+ && POINTER_TYPE_P (type)
+ && handled_component_p (TREE_OPERAND (op0, 0)))
+ {
+ HOST_WIDE_INT bitsize, bitpos;
+ tree offset;
+ enum machine_mode mode;
+ int unsignedp, volatilep;
+ tree base = TREE_OPERAND (op0, 0);
+ base = get_inner_reference (base, &bitsize, &bitpos, &offset,
+ &mode, &unsignedp, &volatilep, false);
+ /* If the reference was to a (constant) zero offset, we can use
+ the address of the base if it has the same base type
+ as the result type. */
+ if (! offset && bitpos == 0
+ && TYPE_MAIN_VARIANT (TREE_TYPE (type))
+ == TYPE_MAIN_VARIANT (TREE_TYPE (base)))
+ return fold_convert (type, fold_addr_expr (base));
+ }
+
+ if (TREE_CODE (op0) == MODIFY_EXPR
+ && TREE_CONSTANT (TREE_OPERAND (op0, 1))
+ /* Detect assigning a bitfield. */
+ && !(TREE_CODE (TREE_OPERAND (op0, 0)) == COMPONENT_REF
+ && DECL_BIT_FIELD
+ (TREE_OPERAND (TREE_OPERAND (op0, 0), 1))))
+ {
+ /* Don't leave an assignment inside a conversion
+ unless assigning a bitfield. */
+ tem = fold_build1 (code, type, TREE_OPERAND (op0, 1));
+ /* First do the assignment, then return converted constant. */
+ tem = build2 (COMPOUND_EXPR, TREE_TYPE (tem), op0, tem);
+ TREE_NO_WARNING (tem) = 1;
+ TREE_USED (tem) = 1;
+ return tem;
+ }
+
+ /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
+ constants (if x has signed type, the sign bit cannot be set
+ in c). This folds extension into the BIT_AND_EXPR.
+ ??? We don't do it for BOOLEAN_TYPE or ENUMERAL_TYPE because they
+ very likely don't have maximal range for their precision and this
+ transformation effectively doesn't preserve non-maximal ranges. */
+ if (TREE_CODE (type) == INTEGER_TYPE
+ && TREE_CODE (op0) == BIT_AND_EXPR
+ && TREE_CODE (TREE_OPERAND (op0, 1)) == INTEGER_CST
+ /* Not if the conversion is to the sub-type. */
+ && TREE_TYPE (type) != TREE_TYPE (op0))
+ {
+ tree and = op0;
+ tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
+ int change = 0;
+
+ if (TYPE_UNSIGNED (TREE_TYPE (and))
+ || (TYPE_PRECISION (type)
+ <= TYPE_PRECISION (TREE_TYPE (and))))
+ change = 1;
+ else if (TYPE_PRECISION (TREE_TYPE (and1))
+ <= HOST_BITS_PER_WIDE_INT
+ && host_integerp (and1, 1))
+ {
+ unsigned HOST_WIDE_INT cst;
+
+ cst = tree_low_cst (and1, 1);
+ cst &= (HOST_WIDE_INT) -1
+ << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
+ change = (cst == 0);
+#ifdef LOAD_EXTEND_OP
+ if (change
+ && !flag_syntax_only
+ && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
+ == ZERO_EXTEND))
+ {
+ tree uns = unsigned_type_for (TREE_TYPE (and0));
+ and0 = fold_convert (uns, and0);
+ and1 = fold_convert (uns, and1);
+ }
+#endif
+ }
+ if (change)
+ {
+ tem = force_fit_type_double (type, TREE_INT_CST_LOW (and1),
+ TREE_INT_CST_HIGH (and1), 0,
+ TREE_OVERFLOW (and1));
+ return fold_build2 (BIT_AND_EXPR, type,
+ fold_convert (type, and0), tem);
+ }
+ }
+
+ /* Convert (T1)(X p+ Y) into ((T1)X p+ Y), for pointer type,
+ when one of the new casts will fold away. Conservatively we assume
+ that this happens when X or Y is NOP_EXPR or Y is INTEGER_CST. */
+ if (POINTER_TYPE_P (type)
+ && TREE_CODE (arg0) == POINTER_PLUS_EXPR
+ && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
+ || TREE_CODE (TREE_OPERAND (arg0, 0)) == NOP_EXPR
+ || TREE_CODE (TREE_OPERAND (arg0, 1)) == NOP_EXPR))
+ {
+ tree arg00 = TREE_OPERAND (arg0, 0);
+ tree arg01 = TREE_OPERAND (arg0, 1);
+
+ return fold_build2 (TREE_CODE (arg0), type, fold_convert (type, arg00),
+ fold_convert (sizetype, arg01));
+ }
+
+ /* Convert (T1)(~(T2)X) into ~(T1)X if T1 and T2 are integral types
+ of the same precision, and X is an integer type not narrower than
+ types T1 or T2, i.e. the cast (T2)X isn't an extension. */
+ if (INTEGRAL_TYPE_P (type)
+ && TREE_CODE (op0) == BIT_NOT_EXPR
+ && INTEGRAL_TYPE_P (TREE_TYPE (op0))
+ && CONVERT_EXPR_P (TREE_OPERAND (op0, 0))
+ && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op0)))
+ {
+ tem = TREE_OPERAND (TREE_OPERAND (op0, 0), 0);
+ if (INTEGRAL_TYPE_P (TREE_TYPE (tem))
+ && TYPE_PRECISION (type) <= TYPE_PRECISION (TREE_TYPE (tem)))
+ return fold_build1 (BIT_NOT_EXPR, type, fold_convert (type, tem));
+ }
+
+ /* Convert (T1)(X * Y) into (T1)X * (T1)Y if T1 is narrower than the
+ type of X and Y (integer types only). */
+ if (INTEGRAL_TYPE_P (type)
+ && TREE_CODE (op0) == MULT_EXPR
+ && INTEGRAL_TYPE_P (TREE_TYPE (op0))
+ && TYPE_PRECISION (type) < TYPE_PRECISION (TREE_TYPE (op0)))
+ {
+ /* Be careful not to introduce new overflows. */
+ tree mult_type;
+ if (TYPE_OVERFLOW_WRAPS (type))
+ mult_type = type;
+ else
+ mult_type = unsigned_type_for (type);
+
+ if (TYPE_PRECISION (mult_type) < TYPE_PRECISION (TREE_TYPE (op0)))
+ {
+ tem = fold_build2 (MULT_EXPR, mult_type,
+ fold_convert (mult_type,
+ TREE_OPERAND (op0, 0)),
+ fold_convert (mult_type,
+ TREE_OPERAND (op0, 1)));
+ return fold_convert (type, tem);
+ }
+ }
+
+ tem = fold_convert_const (code, type, op0);
+ return tem ? tem : NULL_TREE;
+
+ case FIXED_CONVERT_EXPR:
+ tem = fold_convert_const (code, type, arg0);
+ return tem ? tem : NULL_TREE;
+
+ case VIEW_CONVERT_EXPR:
+ if (TREE_TYPE (op0) == type)
+ return op0;
+ if (TREE_CODE (op0) == VIEW_CONVERT_EXPR)
+ return fold_build1 (VIEW_CONVERT_EXPR, type, TREE_OPERAND (op0, 0));
+
+ /* For integral conversions with the same precision or pointer
+ conversions use a NOP_EXPR instead. */
+ if ((INTEGRAL_TYPE_P (type)
+ || POINTER_TYPE_P (type))
+ && (INTEGRAL_TYPE_P (TREE_TYPE (op0))
+ || POINTER_TYPE_P (TREE_TYPE (op0)))
+ && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op0))
+ /* Do not muck with VIEW_CONVERT_EXPRs that convert from
+ a sub-type to its base type as generated by the Ada FE. */
+ && !(INTEGRAL_TYPE_P (TREE_TYPE (op0))
+ && TREE_TYPE (TREE_TYPE (op0))))
+ return fold_convert (type, op0);
+
+ /* Strip inner integral conversions that do not change the precision. */
+ if (CONVERT_EXPR_P (op0)
+ && (INTEGRAL_TYPE_P (TREE_TYPE (op0))
+ || POINTER_TYPE_P (TREE_TYPE (op0)))
+ && (INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (op0, 0)))
+ || POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (op0, 0))))
+ && (TYPE_PRECISION (TREE_TYPE (op0))
+ == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op0, 0)))))
+ return fold_build1 (VIEW_CONVERT_EXPR, type, TREE_OPERAND (op0, 0));
+
+ return fold_view_convert_expr (type, op0);
+
+ case NEGATE_EXPR:
+ tem = fold_negate_expr (arg0);
+ if (tem)
+ return fold_convert (type, tem);
+ return NULL_TREE;
+
+ case ABS_EXPR:
+ if (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST)
+ return fold_abs_const (arg0, type);
+ else if (TREE_CODE (arg0) == NEGATE_EXPR)
+ return fold_build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
+ /* Convert fabs((double)float) into (double)fabsf(float). */
+ else if (TREE_CODE (arg0) == NOP_EXPR
+ && TREE_CODE (type) == REAL_TYPE)
+ {
+ tree targ0 = strip_float_extensions (arg0);
+ if (targ0 != arg0)
+ return fold_convert (type, fold_build1 (ABS_EXPR,
+ TREE_TYPE (targ0),
+ targ0));
+ }
+ /* ABS_EXPR<ABS_EXPR<x>> = ABS_EXPR<x> even if flag_wrapv is on. */
+ else if (TREE_CODE (arg0) == ABS_EXPR)
+ return arg0;
+ else if (tree_expr_nonnegative_p (arg0))
+ return arg0;
+
+ /* Strip sign ops from argument. */
+ if (TREE_CODE (type) == REAL_TYPE)
+ {
+ tem = fold_strip_sign_ops (arg0);
+ if (tem)
+ return fold_build1 (ABS_EXPR, type, fold_convert (type, tem));
+ }
+ return NULL_TREE;
+
+ case CONJ_EXPR:
+ if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
+ return fold_convert (type, arg0);
+ if (TREE_CODE (arg0) == COMPLEX_EXPR)
+ {
+ tree itype = TREE_TYPE (type);
+ tree rpart = fold_convert (itype, TREE_OPERAND (arg0, 0));
+ tree ipart = fold_convert (itype, TREE_OPERAND (arg0, 1));
+ return fold_build2 (COMPLEX_EXPR, type, rpart, negate_expr (ipart));
+ }
+ if (TREE_CODE (arg0) == COMPLEX_CST)
+ {
+ tree itype = TREE_TYPE (type);
+ tree rpart = fold_convert (itype, TREE_REALPART (arg0));
+ tree ipart = fold_convert (itype, TREE_IMAGPART (arg0));
+ return build_complex (type, rpart, negate_expr (ipart));
+ }
+ if (TREE_CODE (arg0) == CONJ_EXPR)
+ return fold_convert (type, TREE_OPERAND (arg0, 0));
+ return NULL_TREE;
+
+ case BIT_NOT_EXPR:
+ if (TREE_CODE (arg0) == INTEGER_CST)
+ return fold_not_const (arg0, type);
+ else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
+ return fold_convert (type, TREE_OPERAND (arg0, 0));
+ /* Convert ~ (-A) to A - 1. */
+ else if (INTEGRAL_TYPE_P (type) && TREE_CODE (arg0) == NEGATE_EXPR)
+ return fold_build2 (MINUS_EXPR, type,
+ fold_convert (type, TREE_OPERAND (arg0, 0)),
+ build_int_cst (type, 1));
+ /* Convert ~ (A - 1) or ~ (A + -1) to -A. */
+ else if (INTEGRAL_TYPE_P (type)
+ && ((TREE_CODE (arg0) == MINUS_EXPR
+ && integer_onep (TREE_OPERAND (arg0, 1)))
+ || (TREE_CODE (arg0) == PLUS_EXPR
+ && integer_all_onesp (TREE_OPERAND (arg0, 1)))))
+ return fold_build1 (NEGATE_EXPR, type,
+ fold_convert (type, TREE_OPERAND (arg0, 0)));
+ /* Convert ~(X ^ Y) to ~X ^ Y or X ^ ~Y if ~X or ~Y simplify. */
+ else if (TREE_CODE (arg0) == BIT_XOR_EXPR
+ && (tem = fold_unary (BIT_NOT_EXPR, type,
+ fold_convert (type,
+ TREE_OPERAND (arg0, 0)))))
+ return fold_build2 (BIT_XOR_EXPR, type, tem,
+ fold_convert (type, TREE_OPERAND (arg0, 1)));
+ else if (TREE_CODE (arg0) == BIT_XOR_EXPR
+ && (tem = fold_unary (BIT_NOT_EXPR, type,
+ fold_convert (type,
+ TREE_OPERAND (arg0, 1)))))
+ return fold_build2 (BIT_XOR_EXPR, type,
+ fold_convert (type, TREE_OPERAND (arg0, 0)), tem);
+ /* Perform BIT_NOT_EXPR on each element individually. */
+ else if (TREE_CODE (arg0) == VECTOR_CST)
+ {
+ tree elements = TREE_VECTOR_CST_ELTS (arg0), elem, list = NULL_TREE;
+ int count = TYPE_VECTOR_SUBPARTS (type), i;
+
+ for (i = 0; i < count; i++)
+ {
+ if (elements)
+ {
+ elem = TREE_VALUE (elements);
+ elem = fold_unary (BIT_NOT_EXPR, TREE_TYPE (type), elem);
+ if (elem == NULL_TREE)
+ break;
+ elements = TREE_CHAIN (elements);
+ }
+ else
+ elem = build_int_cst (TREE_TYPE (type), -1);
+ list = tree_cons (NULL_TREE, elem, list);
+ }
+ if (i == count)
+ return build_vector (type, nreverse (list));
+ }
+
+ return NULL_TREE;
+
+ case TRUTH_NOT_EXPR:
+ /* The argument to invert_truthvalue must have Boolean type. */
+ if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
+ arg0 = fold_convert (boolean_type_node, arg0);
+
+ /* Note that the operand of this must be an int
+ and its values must be 0 or 1.
+ ("true" is a fixed value perhaps depending on the language,
+ but we don't handle values other than 1 correctly yet.) */
+ tem = fold_truth_not_expr (arg0);
+ if (!tem)
+ return NULL_TREE;
+ return fold_convert (type, tem);
+
+ case REALPART_EXPR:
+ if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
+ return fold_convert (type, arg0);
+ if (TREE_CODE (arg0) == COMPLEX_EXPR)
+ return omit_one_operand (type, TREE_OPERAND (arg0, 0),
+ TREE_OPERAND (arg0, 1));
+ if (TREE_CODE (arg0) == COMPLEX_CST)
+ return fold_convert (type, TREE_REALPART (arg0));
+ if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
+ {
+ tree itype = TREE_TYPE (TREE_TYPE (arg0));
+ tem = fold_build2 (TREE_CODE (arg0), itype,
+ fold_build1 (REALPART_EXPR, itype,
+ TREE_OPERAND (arg0, 0)),
+ fold_build1 (REALPART_EXPR, itype,
+ TREE_OPERAND (arg0, 1)));
+ return fold_convert (type, tem);
+ }
+ if (TREE_CODE (arg0) == CONJ_EXPR)
+ {
+ tree itype = TREE_TYPE (TREE_TYPE (arg0));
+ tem = fold_build1 (REALPART_EXPR, itype, TREE_OPERAND (arg0, 0));
+ return fold_convert (type, tem);
+ }
+ if (TREE_CODE (arg0) == CALL_EXPR)
+ {
+ tree fn = get_callee_fndecl (arg0);
+ if (fn && DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL)
+ switch (DECL_FUNCTION_CODE (fn))
+ {
+ CASE_FLT_FN (BUILT_IN_CEXPI):
+ fn = mathfn_built_in (type, BUILT_IN_COS);
+ if (fn)
+ return build_call_expr (fn, 1, CALL_EXPR_ARG (arg0, 0));
+ break;
+
+ default:
+ break;
+ }
+ }
+ return NULL_TREE;
+
+ case IMAGPART_EXPR:
+ if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
+ return fold_convert (type, integer_zero_node);
+ if (TREE_CODE (arg0) == COMPLEX_EXPR)
+ return omit_one_operand (type, TREE_OPERAND (arg0, 1),
+ TREE_OPERAND (arg0, 0));
+ if (TREE_CODE (arg0) == COMPLEX_CST)
+ return fold_convert (type, TREE_IMAGPART (arg0));
+ if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
+ {
+ tree itype = TREE_TYPE (TREE_TYPE (arg0));
+ tem = fold_build2 (TREE_CODE (arg0), itype,
+ fold_build1 (IMAGPART_EXPR, itype,
+ TREE_OPERAND (arg0, 0)),
+ fold_build1 (IMAGPART_EXPR, itype,
+ TREE_OPERAND (arg0, 1)));
+ return fold_convert (type, tem);
+ }
+ if (TREE_CODE (arg0) == CONJ_EXPR)
+ {
+ tree itype = TREE_TYPE (TREE_TYPE (arg0));
+ tem = fold_build1 (IMAGPART_EXPR, itype, TREE_OPERAND (arg0, 0));
+ return fold_convert (type, negate_expr (tem));
+ }
+ if (TREE_CODE (arg0) == CALL_EXPR)
+ {
+ tree fn = get_callee_fndecl (arg0);
+ if (fn && DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL)
+ switch (DECL_FUNCTION_CODE (fn))
+ {
+ CASE_FLT_FN (BUILT_IN_CEXPI):
+ fn = mathfn_built_in (type, BUILT_IN_SIN);
+ if (fn)
+ return build_call_expr (fn, 1, CALL_EXPR_ARG (arg0, 0));
+ break;
+
+ default:
+ break;
+ }
+ }
+ return NULL_TREE;
+
+ default:
+ return NULL_TREE;
+ } /* switch (code) */
+}
+
+
+/* If the operation was a conversion do _not_ mark a resulting constant
+ with TREE_OVERFLOW if the original constant was not. These conversions
+ have implementation defined behavior and retaining the TREE_OVERFLOW
+ flag here would confuse later passes such as VRP. */
+tree
+fold_unary_ignore_overflow (enum tree_code code, tree type, tree op0)
+{
+ tree res = fold_unary (code, type, op0);
+ if (res
+ && TREE_CODE (res) == INTEGER_CST
+ && TREE_CODE (op0) == INTEGER_CST
+ && CONVERT_EXPR_CODE_P (code))
+ TREE_OVERFLOW (res) = TREE_OVERFLOW (op0);
+
+ return res;
+}
+
+/* Fold a binary expression of code CODE and type TYPE with operands
+ OP0 and OP1, containing either a MIN-MAX or a MAX-MIN combination.
+ Return the folded expression if folding is successful. Otherwise,
+ return NULL_TREE. */
+
+static tree
+fold_minmax (enum tree_code code, tree type, tree op0, tree op1)
+{
+ enum tree_code compl_code;
+
+ if (code == MIN_EXPR)
+ compl_code = MAX_EXPR;
+ else if (code == MAX_EXPR)
+ compl_code = MIN_EXPR;
+ else
+ gcc_unreachable ();
+
+ /* MIN (MAX (a, b), b) == b. */
+ if (TREE_CODE (op0) == compl_code
+ && operand_equal_p (TREE_OPERAND (op0, 1), op1, 0))
+ return omit_one_operand (type, op1, TREE_OPERAND (op0, 0));
+
+ /* MIN (MAX (b, a), b) == b. */
+ if (TREE_CODE (op0) == compl_code
+ && operand_equal_p (TREE_OPERAND (op0, 0), op1, 0)
+ && reorder_operands_p (TREE_OPERAND (op0, 1), op1))
+ return omit_one_operand (type, op1, TREE_OPERAND (op0, 1));
+
+ /* MIN (a, MAX (a, b)) == a. */
+ if (TREE_CODE (op1) == compl_code
+ && operand_equal_p (op0, TREE_OPERAND (op1, 0), 0)
+ && reorder_operands_p (op0, TREE_OPERAND (op1, 1)))
+ return omit_one_operand (type, op0, TREE_OPERAND (op1, 1));
+
+ /* MIN (a, MAX (b, a)) == a. */
+ if (TREE_CODE (op1) == compl_code
+ && operand_equal_p (op0, TREE_OPERAND (op1, 1), 0)
+ && reorder_operands_p (op0, TREE_OPERAND (op1, 0)))
+ return omit_one_operand (type, op0, TREE_OPERAND (op1, 0));
+
+ return NULL_TREE;
+}
+
+/* Helper that tries to canonicalize the comparison ARG0 CODE ARG1
+ by changing CODE to reduce the magnitude of constants involved in
+ ARG0 of the comparison.
+ Returns a canonicalized comparison tree if a simplification was
+ possible, otherwise returns NULL_TREE.
+ Set *STRICT_OVERFLOW_P to true if the canonicalization is only
+ valid if signed overflow is undefined. */
+
+static tree
+maybe_canonicalize_comparison_1 (enum tree_code code, tree type,
+ tree arg0, tree arg1,
+ bool *strict_overflow_p)
+{
+ enum tree_code code0 = TREE_CODE (arg0);
+ tree t, cst0 = NULL_TREE;
+ int sgn0;
+ bool swap = false;
+
+ /* Match A +- CST code arg1 and CST code arg1. We can change the
+ first form only if overflow is undefined. */
+ if (!((TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
+ /* In principle pointers also have undefined overflow behavior,
+ but that causes problems elsewhere. */
+ && !POINTER_TYPE_P (TREE_TYPE (arg0))
+ && (code0 == MINUS_EXPR
+ || code0 == PLUS_EXPR)
+ && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
+ || code0 == INTEGER_CST))
+ return NULL_TREE;
+
+ /* Identify the constant in arg0 and its sign. */
+ if (code0 == INTEGER_CST)
+ cst0 = arg0;
+ else
+ cst0 = TREE_OPERAND (arg0, 1);
+ sgn0 = tree_int_cst_sgn (cst0);
+
+ /* Overflowed constants and zero will cause problems. */
+ if (integer_zerop (cst0)
+ || TREE_OVERFLOW (cst0))
+ return NULL_TREE;
+
+ /* See if we can reduce the magnitude of the constant in
+ arg0 by changing the comparison code. */
+ if (code0 == INTEGER_CST)
+ {
+ /* CST <= arg1 -> CST-1 < arg1. */
+ if (code == LE_EXPR && sgn0 == 1)
+ code = LT_EXPR;
+ /* -CST < arg1 -> -CST-1 <= arg1. */
+ else if (code == LT_EXPR && sgn0 == -1)
+ code = LE_EXPR;
+ /* CST > arg1 -> CST-1 >= arg1. */
+ else if (code == GT_EXPR && sgn0 == 1)
+ code = GE_EXPR;
+ /* -CST >= arg1 -> -CST-1 > arg1. */
+ else if (code == GE_EXPR && sgn0 == -1)
+ code = GT_EXPR;
+ else
+ return NULL_TREE;
+ /* arg1 code' CST' might be more canonical. */
+ swap = true;
+ }
+ else
+ {
+ /* A - CST < arg1 -> A - CST-1 <= arg1. */
+ if (code == LT_EXPR
+ && code0 == ((sgn0 == -1) ? PLUS_EXPR : MINUS_EXPR))
+ code = LE_EXPR;
+ /* A + CST > arg1 -> A + CST-1 >= arg1. */
+ else if (code == GT_EXPR
+ && code0 == ((sgn0 == -1) ? MINUS_EXPR : PLUS_EXPR))
+ code = GE_EXPR;
+ /* A + CST <= arg1 -> A + CST-1 < arg1. */
+ else if (code == LE_EXPR
+ && code0 == ((sgn0 == -1) ? MINUS_EXPR : PLUS_EXPR))
+ code = LT_EXPR;
+ /* A - CST >= arg1 -> A - CST-1 > arg1. */
+ else if (code == GE_EXPR
+ && code0 == ((sgn0 == -1) ? PLUS_EXPR : MINUS_EXPR))
+ code = GT_EXPR;
+ else
+ return NULL_TREE;
+ *strict_overflow_p = true;
+ }
+
+ /* Now build the constant reduced in magnitude. But not if that
+ would produce one outside of its types range. */
+ if (INTEGRAL_TYPE_P (TREE_TYPE (cst0))
+ && ((sgn0 == 1
+ && TYPE_MIN_VALUE (TREE_TYPE (cst0))
+ && tree_int_cst_equal (cst0, TYPE_MIN_VALUE (TREE_TYPE (cst0))))
+ || (sgn0 == -1
+ && TYPE_MAX_VALUE (TREE_TYPE (cst0))
+ && tree_int_cst_equal (cst0, TYPE_MAX_VALUE (TREE_TYPE (cst0))))))
+ /* We cannot swap the comparison here as that would cause us to
+ endlessly recurse. */
+ return NULL_TREE;
+
+ t = int_const_binop (sgn0 == -1 ? PLUS_EXPR : MINUS_EXPR,
+ cst0, build_int_cst (TREE_TYPE (cst0), 1), 0);
+ if (code0 != INTEGER_CST)
+ t = fold_build2 (code0, TREE_TYPE (arg0), TREE_OPERAND (arg0, 0), t);
+
+ /* If swapping might yield to a more canonical form, do so. */
+ if (swap)
+ return fold_build2 (swap_tree_comparison (code), type, arg1, t);
+ else
+ return fold_build2 (code, type, t, arg1);
+}
+
+/* Canonicalize the comparison ARG0 CODE ARG1 with type TYPE with undefined
+ overflow further. Try to decrease the magnitude of constants involved
+ by changing LE_EXPR and GE_EXPR to LT_EXPR and GT_EXPR or vice versa
+ and put sole constants at the second argument position.
+ Returns the canonicalized tree if changed, otherwise NULL_TREE. */
+
+static tree
+maybe_canonicalize_comparison (enum tree_code code, tree type,
+ tree arg0, tree arg1)
+{
+ tree t;
+ bool strict_overflow_p;
+ const char * const warnmsg = G_("assuming signed overflow does not occur "
+ "when reducing constant in comparison");
+
+ /* Try canonicalization by simplifying arg0. */
+ strict_overflow_p = false;
+ t = maybe_canonicalize_comparison_1 (code, type, arg0, arg1,
+ &strict_overflow_p);
+ if (t)
+ {
+ if (strict_overflow_p)
+ fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MAGNITUDE);
+ return t;
+ }
+
+ /* Try canonicalization by simplifying arg1 using the swapped
+ comparison. */
+ code = swap_tree_comparison (code);
+ strict_overflow_p = false;
+ t = maybe_canonicalize_comparison_1 (code, type, arg1, arg0,
+ &strict_overflow_p);
+ if (t && strict_overflow_p)
+ fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MAGNITUDE);
+ return t;
+}
+
+/* Return whether BASE + OFFSET + BITPOS may wrap around the address
+ space. This is used to avoid issuing overflow warnings for
+ expressions like &p->x which can not wrap. */
+
+static bool
+pointer_may_wrap_p (tree base, tree offset, HOST_WIDE_INT bitpos)
+{
+ unsigned HOST_WIDE_INT offset_low, total_low;
+ HOST_WIDE_INT size, offset_high, total_high;
+
+ if (!POINTER_TYPE_P (TREE_TYPE (base)))
+ return true;
+
+ if (bitpos < 0)
+ return true;
+
+ if (offset == NULL_TREE)
+ {
+ offset_low = 0;
+ offset_high = 0;
+ }
+ else if (TREE_CODE (offset) != INTEGER_CST || TREE_OVERFLOW (offset))
+ return true;
+ else
+ {
+ offset_low = TREE_INT_CST_LOW (offset);
+ offset_high = TREE_INT_CST_HIGH (offset);
+ }
+
+ if (add_double_with_sign (offset_low, offset_high,
+ bitpos / BITS_PER_UNIT, 0,
+ &total_low, &total_high,
+ true))
+ return true;
+
+ if (total_high != 0)
+ return true;
+
+ size = int_size_in_bytes (TREE_TYPE (TREE_TYPE (base)));
+ if (size <= 0)
+ return true;
+
+ /* We can do slightly better for SIZE if we have an ADDR_EXPR of an
+ array. */
+ if (TREE_CODE (base) == ADDR_EXPR)
+ {
+ HOST_WIDE_INT base_size;
+
+ base_size = int_size_in_bytes (TREE_TYPE (TREE_OPERAND (base, 0)));
+ if (base_size > 0 && size < base_size)
+ size = base_size;
+ }
+
+ return total_low > (unsigned HOST_WIDE_INT) size;
+}
+
+/* Subroutine of fold_binary. This routine performs all of the
+ transformations that are common to the equality/inequality
+ operators (EQ_EXPR and NE_EXPR) and the ordering operators
+ (LT_EXPR, LE_EXPR, GE_EXPR and GT_EXPR). Callers other than
+ fold_binary should call fold_binary. Fold a comparison with
+ tree code CODE and type TYPE with operands OP0 and OP1. Return
+ the folded comparison or NULL_TREE. */
+
+static tree
+fold_comparison (enum tree_code code, tree type, tree op0, tree op1)
+{
+ tree arg0, arg1, tem;
+
+ arg0 = op0;
+ arg1 = op1;
+
+ STRIP_SIGN_NOPS (arg0);
+ STRIP_SIGN_NOPS (arg1);
+
+ tem = fold_relational_const (code, type, arg0, arg1);
+ if (tem != NULL_TREE)
+ return tem;
+
+ /* If one arg is a real or integer constant, put it last. */
+ if (tree_swap_operands_p (arg0, arg1, true))
+ return fold_build2 (swap_tree_comparison (code), type, op1, op0);
+
+ /* Transform comparisons of the form X +- C1 CMP C2 to X CMP C2 +- C1. */
+ if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
+ && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
+ && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
+ && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
+ && (TREE_CODE (arg1) == INTEGER_CST
+ && !TREE_OVERFLOW (arg1)))
+ {
+ tree const1 = TREE_OPERAND (arg0, 1);
+ tree const2 = arg1;
+ tree variable = TREE_OPERAND (arg0, 0);
+ tree lhs;
+ int lhs_add;
+ lhs_add = TREE_CODE (arg0) != PLUS_EXPR;
+
+ lhs = fold_build2 (lhs_add ? PLUS_EXPR : MINUS_EXPR,
+ TREE_TYPE (arg1), const2, const1);
+
+ /* If the constant operation overflowed this can be
+ simplified as a comparison against INT_MAX/INT_MIN. */
+ if (TREE_CODE (lhs) == INTEGER_CST
+ && TREE_OVERFLOW (lhs))
+ {
+ int const1_sgn = tree_int_cst_sgn (const1);
+ enum tree_code code2 = code;
+
+ /* Get the sign of the constant on the lhs if the
+ operation were VARIABLE + CONST1. */
+ if (TREE_CODE (arg0) == MINUS_EXPR)
+ const1_sgn = -const1_sgn;
+
+ /* The sign of the constant determines if we overflowed
+ INT_MAX (const1_sgn == -1) or INT_MIN (const1_sgn == 1).
+ Canonicalize to the INT_MIN overflow by swapping the comparison
+ if necessary. */
+ if (const1_sgn == -1)
+ code2 = swap_tree_comparison (code);
+
+ /* We now can look at the canonicalized case
+ VARIABLE + 1 CODE2 INT_MIN
+ and decide on the result. */
+ if (code2 == LT_EXPR
+ || code2 == LE_EXPR
+ || code2 == EQ_EXPR)
+ return omit_one_operand (type, boolean_false_node, variable);
+ else if (code2 == NE_EXPR
+ || code2 == GE_EXPR
+ || code2 == GT_EXPR)
+ return omit_one_operand (type, boolean_true_node, variable);
+ }
+
+ if (TREE_CODE (lhs) == TREE_CODE (arg1)
+ && (TREE_CODE (lhs) != INTEGER_CST
+ || !TREE_OVERFLOW (lhs)))
+ {
+ fold_overflow_warning (("assuming signed overflow does not occur "
+ "when changing X +- C1 cmp C2 to "
+ "X cmp C1 +- C2"),
+ WARN_STRICT_OVERFLOW_COMPARISON);
+ return fold_build2 (code, type, variable, lhs);
+ }
+ }
+
+ /* For comparisons of pointers we can decompose it to a compile time
+ comparison of the base objects and the offsets into the object.
+ This requires at least one operand being an ADDR_EXPR or a
+ POINTER_PLUS_EXPR to do more than the operand_equal_p test below. */
+ if (POINTER_TYPE_P (TREE_TYPE (arg0))
+ && (TREE_CODE (arg0) == ADDR_EXPR
+ || TREE_CODE (arg1) == ADDR_EXPR
+ || TREE_CODE (arg0) == POINTER_PLUS_EXPR
+ || TREE_CODE (arg1) == POINTER_PLUS_EXPR))
+ {
+ tree base0, base1, offset0 = NULL_TREE, offset1 = NULL_TREE;
+ HOST_WIDE_INT bitsize, bitpos0 = 0, bitpos1 = 0;
+ enum machine_mode mode;
+ int volatilep, unsignedp;
+ bool indirect_base0 = false, indirect_base1 = false;
+
+ /* Get base and offset for the access. Strip ADDR_EXPR for
+ get_inner_reference, but put it back by stripping INDIRECT_REF
+ off the base object if possible. indirect_baseN will be true
+ if baseN is not an address but refers to the object itself. */
+ base0 = arg0;
+ if (TREE_CODE (arg0) == ADDR_EXPR)
+ {
+ base0 = get_inner_reference (TREE_OPERAND (arg0, 0),
+ &bitsize, &bitpos0, &offset0, &mode,
+ &unsignedp, &volatilep, false);
+ if (TREE_CODE (base0) == INDIRECT_REF)
+ base0 = TREE_OPERAND (base0, 0);
+ else
+ indirect_base0 = true;
+ }
+ else if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
+ {
+ base0 = TREE_OPERAND (arg0, 0);
+ offset0 = TREE_OPERAND (arg0, 1);
+ }
+
+ base1 = arg1;
+ if (TREE_CODE (arg1) == ADDR_EXPR)
+ {
+ base1 = get_inner_reference (TREE_OPERAND (arg1, 0),
+ &bitsize, &bitpos1, &offset1, &mode,
+ &unsignedp, &volatilep, false);
+ if (TREE_CODE (base1) == INDIRECT_REF)
+ base1 = TREE_OPERAND (base1, 0);
+ else
+ indirect_base1 = true;
+ }
+ else if (TREE_CODE (arg1) == POINTER_PLUS_EXPR)
+ {
+ base1 = TREE_OPERAND (arg1, 0);
+ offset1 = TREE_OPERAND (arg1, 1);
+ }
+
+ /* If we have equivalent bases we might be able to simplify. */
+ if (indirect_base0 == indirect_base1
+ && operand_equal_p (base0, base1, 0))
+ {
+ /* We can fold this expression to a constant if the non-constant
+ offset parts are equal. */
+ if ((offset0 == offset1
+ || (offset0 && offset1
+ && operand_equal_p (offset0, offset1, 0)))
+ && (code == EQ_EXPR
+ || code == NE_EXPR
+ || POINTER_TYPE_OVERFLOW_UNDEFINED))
+
+ {
+ if (code != EQ_EXPR
+ && code != NE_EXPR
+ && bitpos0 != bitpos1
+ && (pointer_may_wrap_p (base0, offset0, bitpos0)
+ || pointer_may_wrap_p (base1, offset1, bitpos1)))
+ fold_overflow_warning (("assuming pointer wraparound does not "
+ "occur when comparing P +- C1 with "
+ "P +- C2"),
+ WARN_STRICT_OVERFLOW_CONDITIONAL);
+
+ switch (code)
+ {
+ case EQ_EXPR:
+ return constant_boolean_node (bitpos0 == bitpos1, type);
+ case NE_EXPR:
+ return constant_boolean_node (bitpos0 != bitpos1, type);
+ case LT_EXPR:
+ return constant_boolean_node (bitpos0 < bitpos1, type);
+ case LE_EXPR:
+ return constant_boolean_node (bitpos0 <= bitpos1, type);
+ case GE_EXPR:
+ return constant_boolean_node (bitpos0 >= bitpos1, type);
+ case GT_EXPR:
+ return constant_boolean_node (bitpos0 > bitpos1, type);
+ default:;
+ }
+ }
+ /* We can simplify the comparison to a comparison of the variable
+ offset parts if the constant offset parts are equal.
+ Be careful to use signed size type here because otherwise we
+ mess with array offsets in the wrong way. This is possible
+ because pointer arithmetic is restricted to retain within an
+ object and overflow on pointer differences is undefined as of
+ 6.5.6/8 and /9 with respect to the signed ptrdiff_t. */
+ else if (bitpos0 == bitpos1
+ && ((code == EQ_EXPR || code == NE_EXPR)
+ || POINTER_TYPE_OVERFLOW_UNDEFINED))
+ {
+ tree signed_size_type_node;
+ signed_size_type_node = signed_type_for (size_type_node);
+
+ /* By converting to signed size type we cover middle-end pointer
+ arithmetic which operates on unsigned pointer types of size
+ type size and ARRAY_REF offsets which are properly sign or
+ zero extended from their type in case it is narrower than
+ size type. */
+ if (offset0 == NULL_TREE)
+ offset0 = build_int_cst (signed_size_type_node, 0);
+ else
+ offset0 = fold_convert (signed_size_type_node, offset0);
+ if (offset1 == NULL_TREE)
+ offset1 = build_int_cst (signed_size_type_node, 0);
+ else
+ offset1 = fold_convert (signed_size_type_node, offset1);
+
+ if (code != EQ_EXPR
+ && code != NE_EXPR
+ && (pointer_may_wrap_p (base0, offset0, bitpos0)
+ || pointer_may_wrap_p (base1, offset1, bitpos1)))
+ fold_overflow_warning (("assuming pointer wraparound does not "
+ "occur when comparing P +- C1 with "
+ "P +- C2"),
+ WARN_STRICT_OVERFLOW_COMPARISON);
+
+ return fold_build2 (code, type, offset0, offset1);
+ }
+ }
+ /* For non-equal bases we can simplify if they are addresses
+ of local binding decls or constants. */
+ else if (indirect_base0 && indirect_base1
+ /* We know that !operand_equal_p (base0, base1, 0)
+ because the if condition was false. But make
+ sure two decls are not the same. */
+ && base0 != base1
+ && TREE_CODE (arg0) == ADDR_EXPR
+ && TREE_CODE (arg1) == ADDR_EXPR
+ && (((TREE_CODE (base0) == VAR_DECL
+ || TREE_CODE (base0) == PARM_DECL)
+ && (targetm.binds_local_p (base0)
+ || CONSTANT_CLASS_P (base1)))
+ || CONSTANT_CLASS_P (base0))
+ && (((TREE_CODE (base1) == VAR_DECL
+ || TREE_CODE (base1) == PARM_DECL)
+ && (targetm.binds_local_p (base1)
+ || CONSTANT_CLASS_P (base0)))
+ || CONSTANT_CLASS_P (base1)))
+ {
+ if (code == EQ_EXPR)
+ return omit_two_operands (type, boolean_false_node, arg0, arg1);
+ else if (code == NE_EXPR)
+ return omit_two_operands (type, boolean_true_node, arg0, arg1);
+ }
+ /* For equal offsets we can simplify to a comparison of the
+ base addresses. */
+ else if (bitpos0 == bitpos1
+ && (indirect_base0
+ ? base0 != TREE_OPERAND (arg0, 0) : base0 != arg0)
+ && (indirect_base1
+ ? base1 != TREE_OPERAND (arg1, 0) : base1 != arg1)
+ && ((offset0 == offset1)
+ || (offset0 && offset1
+ && operand_equal_p (offset0, offset1, 0))))
+ {
+ if (indirect_base0)
+ base0 = fold_addr_expr (base0);
+ if (indirect_base1)
+ base1 = fold_addr_expr (base1);
+ return fold_build2 (code, type, base0, base1);
+ }
+ }
+
+ /* Transform comparisons of the form X +- C1 CMP Y +- C2 to
+ X CMP Y +- C2 +- C1 for signed X, Y. This is valid if
+ the resulting offset is smaller in absolute value than the
+ original one. */
+ if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
+ && (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
+ && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
+ && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1)))
+ && (TREE_CODE (arg1) == PLUS_EXPR || TREE_CODE (arg1) == MINUS_EXPR)
+ && (TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
+ && !TREE_OVERFLOW (TREE_OPERAND (arg1, 1))))
+ {
+ tree const1 = TREE_OPERAND (arg0, 1);
+ tree const2 = TREE_OPERAND (arg1, 1);
+ tree variable1 = TREE_OPERAND (arg0, 0);
+ tree variable2 = TREE_OPERAND (arg1, 0);
+ tree cst;
+ const char * const warnmsg = G_("assuming signed overflow does not "
+ "occur when combining constants around "
+ "a comparison");
+
+ /* Put the constant on the side where it doesn't overflow and is
+ of lower absolute value than before. */
+ cst = int_const_binop (TREE_CODE (arg0) == TREE_CODE (arg1)
+ ? MINUS_EXPR : PLUS_EXPR,
+ const2, const1, 0);
+ if (!TREE_OVERFLOW (cst)
+ && tree_int_cst_compare (const2, cst) == tree_int_cst_sgn (const2))
+ {
+ fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
+ return fold_build2 (code, type,
+ variable1,
+ fold_build2 (TREE_CODE (arg1), TREE_TYPE (arg1),
+ variable2, cst));
+ }
+
+ cst = int_const_binop (TREE_CODE (arg0) == TREE_CODE (arg1)
+ ? MINUS_EXPR : PLUS_EXPR,
+ const1, const2, 0);
+ if (!TREE_OVERFLOW (cst)
+ && tree_int_cst_compare (const1, cst) == tree_int_cst_sgn (const1))
+ {
+ fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
+ return fold_build2 (code, type,
+ fold_build2 (TREE_CODE (arg0), TREE_TYPE (arg0),
+ variable1, cst),
+ variable2);
+ }
+ }
+
+ /* Transform comparisons of the form X * C1 CMP 0 to X CMP 0 in the
+ signed arithmetic case. That form is created by the compiler
+ often enough for folding it to be of value. One example is in
+ computing loop trip counts after Operator Strength Reduction. */
+ if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
+ && TREE_CODE (arg0) == MULT_EXPR
+ && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
+ && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1)))
+ && integer_zerop (arg1))
+ {
+ tree const1 = TREE_OPERAND (arg0, 1);
+ tree const2 = arg1; /* zero */
+ tree variable1 = TREE_OPERAND (arg0, 0);
+ enum tree_code cmp_code = code;
+
+ gcc_assert (!integer_zerop (const1));
+
+ fold_overflow_warning (("assuming signed overflow does not occur when "
+ "eliminating multiplication in comparison "
+ "with zero"),
+ WARN_STRICT_OVERFLOW_COMPARISON);
+
+ /* If const1 is negative we swap the sense of the comparison. */
+ if (tree_int_cst_sgn (const1) < 0)
+ cmp_code = swap_tree_comparison (cmp_code);
+
+ return fold_build2 (cmp_code, type, variable1, const2);
+ }
+
+ tem = maybe_canonicalize_comparison (code, type, op0, op1);
+ if (tem)
+ return tem;
+
+ if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
+ {
+ tree targ0 = strip_float_extensions (arg0);
+ tree targ1 = strip_float_extensions (arg1);
+ tree newtype = TREE_TYPE (targ0);
+
+ if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
+ newtype = TREE_TYPE (targ1);
+
+ /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
+ if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
+ return fold_build2 (code, type, fold_convert (newtype, targ0),
+ fold_convert (newtype, targ1));
+
+ /* (-a) CMP (-b) -> b CMP a */
+ if (TREE_CODE (arg0) == NEGATE_EXPR
+ && TREE_CODE (arg1) == NEGATE_EXPR)
+ return fold_build2 (code, type, TREE_OPERAND (arg1, 0),
+ TREE_OPERAND (arg0, 0));
+
+ if (TREE_CODE (arg1) == REAL_CST)
+ {
+ REAL_VALUE_TYPE cst;
+ cst = TREE_REAL_CST (arg1);
+
+ /* (-a) CMP CST -> a swap(CMP) (-CST) */
+ if (TREE_CODE (arg0) == NEGATE_EXPR)
+ return fold_build2 (swap_tree_comparison (code), type,
+ TREE_OPERAND (arg0, 0),
+ build_real (TREE_TYPE (arg1),
+ REAL_VALUE_NEGATE (cst)));
+
+ /* IEEE doesn't distinguish +0 and -0 in comparisons. */
+ /* a CMP (-0) -> a CMP 0 */
+ if (REAL_VALUE_MINUS_ZERO (cst))
+ return fold_build2 (code, type, arg0,
+ build_real (TREE_TYPE (arg1), dconst0));
+
+ /* x != NaN is always true, other ops are always false. */
+ if (REAL_VALUE_ISNAN (cst)
+ && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
+ {
+ tem = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
+ return omit_one_operand (type, tem, arg0);
+ }
+
+ /* Fold comparisons against infinity. */
+ if (REAL_VALUE_ISINF (cst)
+ && MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1))))
+ {
+ tem = fold_inf_compare (code, type, arg0, arg1);
+ if (tem != NULL_TREE)
+ return tem;
+ }
+ }
+
+ /* If this is a comparison of a real constant with a PLUS_EXPR
+ or a MINUS_EXPR of a real constant, we can convert it into a
+ comparison with a revised real constant as long as no overflow
+ occurs when unsafe_math_optimizations are enabled. */
+ if (flag_unsafe_math_optimizations
+ && TREE_CODE (arg1) == REAL_CST
+ && (TREE_CODE (arg0) == PLUS_EXPR
+ || TREE_CODE (arg0) == MINUS_EXPR)
+ && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
+ && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
+ ? MINUS_EXPR : PLUS_EXPR,
+ arg1, TREE_OPERAND (arg0, 1), 0))
+ && !TREE_OVERFLOW (tem))
+ return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
+
+ /* Likewise, we can simplify a comparison of a real constant with
+ a MINUS_EXPR whose first operand is also a real constant, i.e.
+ (c1 - x) < c2 becomes x > c1-c2. Reordering is allowed on
+ floating-point types only if -fassociative-math is set. */
+ if (flag_associative_math
+ && TREE_CODE (arg1) == REAL_CST
+ && TREE_CODE (arg0) == MINUS_EXPR
+ && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
+ && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
+ arg1, 0))
+ && !TREE_OVERFLOW (tem))
+ return fold_build2 (swap_tree_comparison (code), type,
+ TREE_OPERAND (arg0, 1), tem);
+
+ /* Fold comparisons against built-in math functions. */
+ if (TREE_CODE (arg1) == REAL_CST
+ && flag_unsafe_math_optimizations
+ && ! flag_errno_math)
+ {
+ enum built_in_function fcode = builtin_mathfn_code (arg0);
+
+ if (fcode != END_BUILTINS)
+ {
+ tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
+ if (tem != NULL_TREE)
+ return tem;
+ }
+ }
+ }
+
+ if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
+ && CONVERT_EXPR_P (arg0))
+ {
+ /* If we are widening one operand of an integer comparison,
+ see if the other operand is similarly being widened. Perhaps we
+ can do the comparison in the narrower type. */
+ tem = fold_widened_comparison (code, type, arg0, arg1);
+ if (tem)
+ return tem;
+
+ /* Or if we are changing signedness. */
+ tem = fold_sign_changed_comparison (code, type, arg0, arg1);
+ if (tem)
+ return tem;
+ }
+
+ /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
+ constant, we can simplify it. */
+ if (TREE_CODE (arg1) == INTEGER_CST
+ && (TREE_CODE (arg0) == MIN_EXPR
+ || TREE_CODE (arg0) == MAX_EXPR)
+ && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
+ {
+ tem = optimize_minmax_comparison (code, type, op0, op1);
+ if (tem)
+ return tem;
+ }
+
+ /* Simplify comparison of something with itself. (For IEEE
+ floating-point, we can only do some of these simplifications.) */
+ if (operand_equal_p (arg0, arg1, 0))
+ {
+ switch (code)
+ {
+ case EQ_EXPR:
+ if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
+ || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
+ return constant_boolean_node (1, type);
+ break;
+
+ case GE_EXPR:
+ case LE_EXPR:
+ if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
+ || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
+ return constant_boolean_node (1, type);
+ return fold_build2 (EQ_EXPR, type, arg0, arg1);
+
+ case NE_EXPR:
+ /* For NE, we can only do this simplification if integer
+ or we don't honor IEEE floating point NaNs. */
+ if (FLOAT_TYPE_P (TREE_TYPE (arg0))
+ && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
+ break;
+ /* ... fall through ... */
+ case GT_EXPR:
+ case LT_EXPR:
+ return constant_boolean_node (0, type);
+ default:
+ gcc_unreachable ();
+ }
+ }
+
+ /* If we are comparing an expression that just has comparisons
+ of two integer values, arithmetic expressions of those comparisons,
+ and constants, we can simplify it. There are only three cases
+ to check: the two values can either be equal, the first can be
+ greater, or the second can be greater. Fold the expression for
+ those three values. Since each value must be 0 or 1, we have
+ eight possibilities, each of which corresponds to the constant 0
+ or 1 or one of the six possible comparisons.
+
+ This handles common cases like (a > b) == 0 but also handles
+ expressions like ((x > y) - (y > x)) > 0, which supposedly
+ occur in macroized code. */
+
+ if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
+ {
+ tree cval1 = 0, cval2 = 0;
+ int save_p = 0;
+
+ if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
+ /* Don't handle degenerate cases here; they should already
+ have been handled anyway. */
+ && cval1 != 0 && cval2 != 0
+ && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
+ && TREE_TYPE (cval1) == TREE_TYPE (cval2)
+ && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
+ && TYPE_MAX_VALUE (TREE_TYPE (cval1))
+ && TYPE_MAX_VALUE (TREE_TYPE (cval2))
+ && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
+ TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
+ {
+ tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
+ tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
+
+ /* We can't just pass T to eval_subst in case cval1 or cval2
+ was the same as ARG1. */
+
+ tree high_result
+ = fold_build2 (code, type,
+ eval_subst (arg0, cval1, maxval,
+ cval2, minval),
+ arg1);
+ tree equal_result
+ = fold_build2 (code, type,
+ eval_subst (arg0, cval1, maxval,
+ cval2, maxval),
+ arg1);
+ tree low_result
+ = fold_build2 (code, type,
+ eval_subst (arg0, cval1, minval,
+ cval2, maxval),
+ arg1);
+
+ /* All three of these results should be 0 or 1. Confirm they are.
+ Then use those values to select the proper code to use. */
+
+ if (TREE_CODE (high_result) == INTEGER_CST
+ && TREE_CODE (equal_result) == INTEGER_CST
+ && TREE_CODE (low_result) == INTEGER_CST)
+ {
+ /* Make a 3-bit mask with the high-order bit being the
+ value for `>', the next for '=', and the low for '<'. */
+ switch ((integer_onep (high_result) * 4)
+ + (integer_onep (equal_result) * 2)
+ + integer_onep (low_result))
+ {
+ case 0:
+ /* Always false. */
+ return omit_one_operand (type, integer_zero_node, arg0);
+ case 1:
+ code = LT_EXPR;
+ break;
+ case 2:
+ code = EQ_EXPR;
+ break;
+ case 3:
+ code = LE_EXPR;
+ break;
+ case 4:
+ code = GT_EXPR;
+ break;
+ case 5:
+ code = NE_EXPR;
+ break;
+ case 6:
+ code = GE_EXPR;
+ break;
+ case 7:
+ /* Always true. */
+ return omit_one_operand (type, integer_one_node, arg0);
+ }
+
+ if (save_p)
+ return save_expr (build2 (code, type, cval1, cval2));
+ return fold_build2 (code, type, cval1, cval2);
+ }
+ }
+ }
+
+ /* We can fold X/C1 op C2 where C1 and C2 are integer constants
+ into a single range test. */
+ if ((TREE_CODE (arg0) == TRUNC_DIV_EXPR
+ || TREE_CODE (arg0) == EXACT_DIV_EXPR)
+ && TREE_CODE (arg1) == INTEGER_CST
+ && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
+ && !integer_zerop (TREE_OPERAND (arg0, 1))
+ && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
+ && !TREE_OVERFLOW (arg1))
+ {
+ tem = fold_div_compare (code, type, arg0, arg1);
+ if (tem != NULL_TREE)
+ return tem;
+ }
+
+ /* Fold ~X op ~Y as Y op X. */
+ if (TREE_CODE (arg0) == BIT_NOT_EXPR
+ && TREE_CODE (arg1) == BIT_NOT_EXPR)
+ {
+ tree cmp_type = TREE_TYPE (TREE_OPERAND (arg0, 0));
+ return fold_build2 (code, type,
+ fold_convert (cmp_type, TREE_OPERAND (arg1, 0)),
+ TREE_OPERAND (arg0, 0));
+ }
+
+ /* Fold ~X op C as X op' ~C, where op' is the swapped comparison. */
+ if (TREE_CODE (arg0) == BIT_NOT_EXPR
+ && TREE_CODE (arg1) == INTEGER_CST)
+ {
+ tree cmp_type = TREE_TYPE (TREE_OPERAND (arg0, 0));
+ return fold_build2 (swap_tree_comparison (code), type,
+ TREE_OPERAND (arg0, 0),
+ fold_build1 (BIT_NOT_EXPR, cmp_type,
+ fold_convert (cmp_type, arg1)));
+ }
+
+ return NULL_TREE;
+}
+
+
+/* Subroutine of fold_binary. Optimize complex multiplications of the
+ form z * conj(z), as pow(realpart(z),2) + pow(imagpart(z),2). The
+ argument EXPR represents the expression "z" of type TYPE. */
+
+static tree
+fold_mult_zconjz (tree type, tree expr)
+{
+ tree itype = TREE_TYPE (type);
+ tree rpart, ipart, tem;
+
+ if (TREE_CODE (expr) == COMPLEX_EXPR)
+ {
+ rpart = TREE_OPERAND (expr, 0);
+ ipart = TREE_OPERAND (expr, 1);
+ }
+ else if (TREE_CODE (expr) == COMPLEX_CST)
+ {
+ rpart = TREE_REALPART (expr);
+ ipart = TREE_IMAGPART (expr);
+ }
+ else
+ {
+ expr = save_expr (expr);
+ rpart = fold_build1 (REALPART_EXPR, itype, expr);
+ ipart = fold_build1 (IMAGPART_EXPR, itype, expr);
+ }
+
+ rpart = save_expr (rpart);
+ ipart = save_expr (ipart);
+ tem = fold_build2 (PLUS_EXPR, itype,
+ fold_build2 (MULT_EXPR, itype, rpart, rpart),
+ fold_build2 (MULT_EXPR, itype, ipart, ipart));
+ return fold_build2 (COMPLEX_EXPR, type, tem,
+ fold_convert (itype, integer_zero_node));
+}
+
+
+/* Subroutine of fold_binary. If P is the value of EXPR, computes
+ power-of-two M and (arbitrary) N such that M divides (P-N). This condition
+ guarantees that P and N have the same least significant log2(M) bits.
+ N is not otherwise constrained. In particular, N is not normalized to
+ 0 <= N < M as is common. In general, the precise value of P is unknown.
+ M is chosen as large as possible such that constant N can be determined.
+
+ Returns M and sets *RESIDUE to N. */
+
+static unsigned HOST_WIDE_INT
+get_pointer_modulus_and_residue (tree expr, unsigned HOST_WIDE_INT *residue)
+{
+ enum tree_code code;
+
+ *residue = 0;
+
+ code = TREE_CODE (expr);
+ if (code == ADDR_EXPR)
+ {
+ expr = TREE_OPERAND (expr, 0);
+ if (handled_component_p (expr))
+ {
+ HOST_WIDE_INT bitsize, bitpos;
+ tree offset;
+ enum machine_mode mode;
+ int unsignedp, volatilep;
+
+ expr = get_inner_reference (expr, &bitsize, &bitpos, &offset,
+ &mode, &unsignedp, &volatilep, false);
+ *residue = bitpos / BITS_PER_UNIT;
+ if (offset)
+ {
+ if (TREE_CODE (offset) == INTEGER_CST)
+ *residue += TREE_INT_CST_LOW (offset);
+ else
+ /* We don't handle more complicated offset expressions. */
+ return 1;
+ }
+ }
+
+ if (DECL_P (expr) && TREE_CODE (expr) != FUNCTION_DECL)
+ return DECL_ALIGN_UNIT (expr);
+ }
+ else if (code == POINTER_PLUS_EXPR)
+ {
+ tree op0, op1;
+ unsigned HOST_WIDE_INT modulus;
+ enum tree_code inner_code;
+
+ op0 = TREE_OPERAND (expr, 0);
+ STRIP_NOPS (op0);
+ modulus = get_pointer_modulus_and_residue (op0, residue);
+
+ op1 = TREE_OPERAND (expr, 1);
+ STRIP_NOPS (op1);
+ inner_code = TREE_CODE (op1);
+ if (inner_code == INTEGER_CST)
+ {
+ *residue += TREE_INT_CST_LOW (op1);
+ return modulus;
+ }
+ else if (inner_code == MULT_EXPR)
+ {
+ op1 = TREE_OPERAND (op1, 1);
+ if (TREE_CODE (op1) == INTEGER_CST)
+ {
+ unsigned HOST_WIDE_INT align;
+
+ /* Compute the greatest power-of-2 divisor of op1. */
+ align = TREE_INT_CST_LOW (op1);
+ align &= -align;
+
+ /* If align is non-zero and less than *modulus, replace
+ *modulus with align., If align is 0, then either op1 is 0
+ or the greatest power-of-2 divisor of op1 doesn't fit in an
+ unsigned HOST_WIDE_INT. In either case, no additional
+ constraint is imposed. */
+ if (align)
+ modulus = MIN (modulus, align);
+
+ return modulus;
+ }
+ }
+ }
+
+ /* If we get here, we were unable to determine anything useful about the
+ expression. */
+ return 1;
+}
+
+
+/* Fold a binary expression of code CODE and type TYPE with operands
+ OP0 and OP1. Return the folded expression if folding is
+ successful. Otherwise, return NULL_TREE. */
+
+tree
+fold_binary (enum tree_code code, tree type, tree op0, tree op1)
+{
+ enum tree_code_class kind = TREE_CODE_CLASS (code);
+ tree arg0, arg1, tem;
+ tree t1 = NULL_TREE;
+ bool strict_overflow_p;
+
+ gcc_assert (IS_EXPR_CODE_CLASS (kind)
+ && TREE_CODE_LENGTH (code) == 2
+ && op0 != NULL_TREE
+ && op1 != NULL_TREE);
+
+ arg0 = op0;
+ arg1 = op1;
+
+ /* Strip any conversions that don't change the mode. This is
+ safe for every expression, except for a comparison expression
+ because its signedness is derived from its operands. So, in
+ the latter case, only strip conversions that don't change the
+ signedness. MIN_EXPR/MAX_EXPR also need signedness of arguments
+ preserved.
+
+ Note that this is done as an internal manipulation within the
+ constant folder, in order to find the simplest representation
+ of the arguments so that their form can be studied. In any
+ cases, the appropriate type conversions should be put back in
+ the tree that will get out of the constant folder. */
+
+ if (kind == tcc_comparison || code == MIN_EXPR || code == MAX_EXPR)
+ {
+ STRIP_SIGN_NOPS (arg0);
+ STRIP_SIGN_NOPS (arg1);
+ }
+ else
+ {
+ STRIP_NOPS (arg0);
+ STRIP_NOPS (arg1);
+ }
+
+ /* Note that TREE_CONSTANT isn't enough: static var addresses are
+ constant but we can't do arithmetic on them. */
+ if ((TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
+ || (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
+ || (TREE_CODE (arg0) == FIXED_CST && TREE_CODE (arg1) == FIXED_CST)
+ || (TREE_CODE (arg0) == FIXED_CST && TREE_CODE (arg1) == INTEGER_CST)
+ || (TREE_CODE (arg0) == COMPLEX_CST && TREE_CODE (arg1) == COMPLEX_CST)
+ || (TREE_CODE (arg0) == VECTOR_CST && TREE_CODE (arg1) == VECTOR_CST))
+ {
+ if (kind == tcc_binary)
+ {
+ /* Make sure type and arg0 have the same saturating flag. */
+ gcc_assert (TYPE_SATURATING (type)
+ == TYPE_SATURATING (TREE_TYPE (arg0)));
+ tem = const_binop (code, arg0, arg1, 0);
+ }
+ else if (kind == tcc_comparison)
+ tem = fold_relational_const (code, type, arg0, arg1);
+ else
+ tem = NULL_TREE;
+
+ if (tem != NULL_TREE)
+ {
+ if (TREE_TYPE (tem) != type)
+ tem = fold_convert (type, tem);
+ return tem;
+ }
+ }
+
+ /* If this is a commutative operation, and ARG0 is a constant, move it
+ to ARG1 to reduce the number of tests below. */
+ if (commutative_tree_code (code)
+ && tree_swap_operands_p (arg0, arg1, true))
+ return fold_build2 (code, type, op1, op0);
+
+ /* ARG0 is the first operand of EXPR, and ARG1 is the second operand.
+
+ First check for cases where an arithmetic operation is applied to a
+ compound, conditional, or comparison operation. Push the arithmetic
+ operation inside the compound or conditional to see if any folding
+ can then be done. Convert comparison to conditional for this purpose.
+ The also optimizes non-constant cases that used to be done in
+ expand_expr.
+
+ Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
+ one of the operands is a comparison and the other is a comparison, a
+ BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
+ code below would make the expression more complex. Change it to a
+ TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
+ TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
+
+ if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
+ || code == EQ_EXPR || code == NE_EXPR)
+ && ((truth_value_p (TREE_CODE (arg0))
+ && (truth_value_p (TREE_CODE (arg1))
+ || (TREE_CODE (arg1) == BIT_AND_EXPR
+ && integer_onep (TREE_OPERAND (arg1, 1)))))
+ || (truth_value_p (TREE_CODE (arg1))
+ && (truth_value_p (TREE_CODE (arg0))
+ || (TREE_CODE (arg0) == BIT_AND_EXPR
+ && integer_onep (TREE_OPERAND (arg0, 1)))))))
+ {
+ tem = fold_build2 (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
+ : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
+ : TRUTH_XOR_EXPR,
+ boolean_type_node,
+ fold_convert (boolean_type_node, arg0),
+ fold_convert (boolean_type_node, arg1));
+
+ if (code == EQ_EXPR)
+ tem = invert_truthvalue (tem);
+
+ return fold_convert (type, tem);
+ }
+
+ if (TREE_CODE_CLASS (code) == tcc_binary
+ || TREE_CODE_CLASS (code) == tcc_comparison)
+ {
+ if (TREE_CODE (arg0) == COMPOUND_EXPR)
+ return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
+ fold_build2 (code, type,
+ fold_convert (TREE_TYPE (op0),
+ TREE_OPERAND (arg0, 1)),
+ op1));
+ if (TREE_CODE (arg1) == COMPOUND_EXPR
+ && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
+ return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
+ fold_build2 (code, type, op0,
+ fold_convert (TREE_TYPE (op1),
+ TREE_OPERAND (arg1, 1))));
+
+ if (TREE_CODE (arg0) == COND_EXPR || COMPARISON_CLASS_P (arg0))
+ {
+ tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
+ arg0, arg1,
+ /*cond_first_p=*/1);
+ if (tem != NULL_TREE)
+ return tem;
+ }
+
+ if (TREE_CODE (arg1) == COND_EXPR || COMPARISON_CLASS_P (arg1))
+ {
+ tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
+ arg1, arg0,
+ /*cond_first_p=*/0);
+ if (tem != NULL_TREE)
+ return tem;
+ }
+ }
+
+ switch (code)
+ {
+ case POINTER_PLUS_EXPR:
+ /* 0 +p index -> (type)index */
+ if (integer_zerop (arg0))
+ return non_lvalue (fold_convert (type, arg1));
+
+ /* PTR +p 0 -> PTR */
+ if (integer_zerop (arg1))
+ return non_lvalue (fold_convert (type, arg0));
+
+ /* INT +p INT -> (PTR)(INT + INT). Stripping types allows for this. */
+ if (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
+ && INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
+ return fold_convert (type, fold_build2 (PLUS_EXPR, sizetype,
+ fold_convert (sizetype, arg1),
+ fold_convert (sizetype, arg0)));
+
+ /* index +p PTR -> PTR +p index */
+ if (POINTER_TYPE_P (TREE_TYPE (arg1))
+ && INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
+ return fold_build2 (POINTER_PLUS_EXPR, type,
+ fold_convert (type, arg1),
+ fold_convert (sizetype, arg0));
+
+ /* (PTR +p B) +p A -> PTR +p (B + A) */
+ if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
+ {
+ tree inner;
+ tree arg01 = fold_convert (sizetype, TREE_OPERAND (arg0, 1));
+ tree arg00 = TREE_OPERAND (arg0, 0);
+ inner = fold_build2 (PLUS_EXPR, sizetype,
+ arg01, fold_convert (sizetype, arg1));
+ return fold_convert (type,
+ fold_build2 (POINTER_PLUS_EXPR,
+ TREE_TYPE (arg00), arg00, inner));
+ }
+
+ /* PTR_CST +p CST -> CST1 */
+ if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
+ return fold_build2 (PLUS_EXPR, type, arg0, fold_convert (type, arg1));
+
+ /* Try replacing &a[i1] +p c * i2 with &a[i1 + i2], if c is step
+ of the array. Loop optimizer sometimes produce this type of
+ expressions. */
+ if (TREE_CODE (arg0) == ADDR_EXPR)
+ {
+ tem = try_move_mult_to_index (arg0, fold_convert (sizetype, arg1));
+ if (tem)
+ return fold_convert (type, tem);
+ }
+
+ return NULL_TREE;
+
+ case PLUS_EXPR:
+ /* A + (-B) -> A - B */
+ if (TREE_CODE (arg1) == NEGATE_EXPR)
+ return fold_build2 (MINUS_EXPR, type,
+ fold_convert (type, arg0),
+ fold_convert (type, TREE_OPERAND (arg1, 0)));
+ /* (-A) + B -> B - A */
+ if (TREE_CODE (arg0) == NEGATE_EXPR
+ && reorder_operands_p (TREE_OPERAND (arg0, 0), arg1))
+ return fold_build2 (MINUS_EXPR, type,
+ fold_convert (type, arg1),
+ fold_convert (type, TREE_OPERAND (arg0, 0)));
+
+ if (INTEGRAL_TYPE_P (type))
+ {
+ /* Convert ~A + 1 to -A. */
+ if (TREE_CODE (arg0) == BIT_NOT_EXPR
+ && integer_onep (arg1))
+ return fold_build1 (NEGATE_EXPR, type,
+ fold_convert (type, TREE_OPERAND (arg0, 0)));
+
+ /* ~X + X is -1. */
+ if (TREE_CODE (arg0) == BIT_NOT_EXPR
+ && !TYPE_OVERFLOW_TRAPS (type))
+ {
+ tree tem = TREE_OPERAND (arg0, 0);
+
+ STRIP_NOPS (tem);
+ if (operand_equal_p (tem, arg1, 0))
+ {
+ t1 = build_int_cst_type (type, -1);
+ return omit_one_operand (type, t1, arg1);
+ }
+ }
+
+ /* X + ~X is -1. */
+ if (TREE_CODE (arg1) == BIT_NOT_EXPR
+ && !TYPE_OVERFLOW_TRAPS (type))
+ {
+ tree tem = TREE_OPERAND (arg1, 0);
+
+ STRIP_NOPS (tem);
+ if (operand_equal_p (arg0, tem, 0))
+ {
+ t1 = build_int_cst_type (type, -1);
+ return omit_one_operand (type, t1, arg0);
+ }
+ }
+
+ /* X + (X / CST) * -CST is X % CST. */
+ if (TREE_CODE (arg1) == MULT_EXPR
+ && TREE_CODE (TREE_OPERAND (arg1, 0)) == TRUNC_DIV_EXPR
+ && operand_equal_p (arg0,
+ TREE_OPERAND (TREE_OPERAND (arg1, 0), 0), 0))
+ {
+ tree cst0 = TREE_OPERAND (TREE_OPERAND (arg1, 0), 1);
+ tree cst1 = TREE_OPERAND (arg1, 1);
+ tree sum = fold_binary (PLUS_EXPR, TREE_TYPE (cst1), cst1, cst0);
+ if (sum && integer_zerop (sum))
+ return fold_convert (type,
+ fold_build2 (TRUNC_MOD_EXPR,
+ TREE_TYPE (arg0), arg0, cst0));
+ }
+ }
+
+ /* Handle (A1 * C1) + (A2 * C2) with A1, A2 or C1, C2 being the
+ same or one. Make sure type is not saturating.
+ fold_plusminus_mult_expr will re-associate. */
+ if ((TREE_CODE (arg0) == MULT_EXPR
+ || TREE_CODE (arg1) == MULT_EXPR)
+ && !TYPE_SATURATING (type)
+ && (!FLOAT_TYPE_P (type) || flag_associative_math))
+ {
+ tree tem = fold_plusminus_mult_expr (code, type, arg0, arg1);
+ if (tem)
+ return tem;
+ }
+
+ if (! FLOAT_TYPE_P (type))
+ {
+ if (integer_zerop (arg1))
+ return non_lvalue (fold_convert (type, arg0));
+
+ /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
+ with a constant, and the two constants have no bits in common,
+ we should treat this as a BIT_IOR_EXPR since this may produce more
+ simplifications. */
+ if (TREE_CODE (arg0) == BIT_AND_EXPR
+ && TREE_CODE (arg1) == BIT_AND_EXPR
+ && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
+ && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
+ && integer_zerop (const_binop (BIT_AND_EXPR,
+ TREE_OPERAND (arg0, 1),
+ TREE_OPERAND (arg1, 1), 0)))
+ {
+ code = BIT_IOR_EXPR;
+ goto bit_ior;
+ }
+
+ /* Reassociate (plus (plus (mult) (foo)) (mult)) as
+ (plus (plus (mult) (mult)) (foo)) so that we can
+ take advantage of the factoring cases below. */
+ if (((TREE_CODE (arg0) == PLUS_EXPR
+ || TREE_CODE (arg0) == MINUS_EXPR)
&& TREE_CODE (arg1) == MULT_EXPR)
- || (TREE_CODE (arg1) == PLUS_EXPR
+ || ((TREE_CODE (arg1) == PLUS_EXPR
+ || TREE_CODE (arg1) == MINUS_EXPR)
&& TREE_CODE (arg0) == MULT_EXPR))
{
- tree parg0, parg1, parg, marg;
+ tree parg0, parg1, parg, marg;
+ enum tree_code pcode;
+
+ if (TREE_CODE (arg1) == MULT_EXPR)
+ parg = arg0, marg = arg1;
+ else
+ parg = arg1, marg = arg0;
+ pcode = TREE_CODE (parg);
+ parg0 = TREE_OPERAND (parg, 0);
+ parg1 = TREE_OPERAND (parg, 1);
+ STRIP_NOPS (parg0);
+ STRIP_NOPS (parg1);
+
+ if (TREE_CODE (parg0) == MULT_EXPR
+ && TREE_CODE (parg1) != MULT_EXPR)
+ return fold_build2 (pcode, type,
+ fold_build2 (PLUS_EXPR, type,
+ fold_convert (type, parg0),
+ fold_convert (type, marg)),
+ fold_convert (type, parg1));
+ if (TREE_CODE (parg0) != MULT_EXPR
+ && TREE_CODE (parg1) == MULT_EXPR)
+ return fold_build2 (PLUS_EXPR, type,
+ fold_convert (type, parg0),
+ fold_build2 (pcode, type,
+ fold_convert (type, marg),
+ fold_convert (type,
+ parg1)));
+ }
+ }
+ else
+ {
+ /* See if ARG1 is zero and X + ARG1 reduces to X. */
+ if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
+ return non_lvalue (fold_convert (type, arg0));
+
+ /* Likewise if the operands are reversed. */
+ if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
+ return non_lvalue (fold_convert (type, arg1));
+
+ /* Convert X + -C into X - C. */
+ if (TREE_CODE (arg1) == REAL_CST
+ && REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1)))
+ {
+ tem = fold_negate_const (arg1, type);
+ if (!TREE_OVERFLOW (arg1) || !flag_trapping_math)
+ return fold_build2 (MINUS_EXPR, type,
+ fold_convert (type, arg0),
+ fold_convert (type, tem));
+ }
+
+ /* Fold __complex__ ( x, 0 ) + __complex__ ( 0, y )
+ to __complex__ ( x, y ). This is not the same for SNaNs or
+ if signed zeros are involved. */
+ if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
+ && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
+ && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0)))
+ {
+ tree rtype = TREE_TYPE (TREE_TYPE (arg0));
+ tree arg0r = fold_unary (REALPART_EXPR, rtype, arg0);
+ tree arg0i = fold_unary (IMAGPART_EXPR, rtype, arg0);
+ bool arg0rz = false, arg0iz = false;
+ if ((arg0r && (arg0rz = real_zerop (arg0r)))
+ || (arg0i && (arg0iz = real_zerop (arg0i))))
+ {
+ tree arg1r = fold_unary (REALPART_EXPR, rtype, arg1);
+ tree arg1i = fold_unary (IMAGPART_EXPR, rtype, arg1);
+ if (arg0rz && arg1i && real_zerop (arg1i))
+ {
+ tree rp = arg1r ? arg1r
+ : build1 (REALPART_EXPR, rtype, arg1);
+ tree ip = arg0i ? arg0i
+ : build1 (IMAGPART_EXPR, rtype, arg0);
+ return fold_build2 (COMPLEX_EXPR, type, rp, ip);
+ }
+ else if (arg0iz && arg1r && real_zerop (arg1r))
+ {
+ tree rp = arg0r ? arg0r
+ : build1 (REALPART_EXPR, rtype, arg0);
+ tree ip = arg1i ? arg1i
+ : build1 (IMAGPART_EXPR, rtype, arg1);
+ return fold_build2 (COMPLEX_EXPR, type, rp, ip);
+ }
+ }
+ }
+
+ if (flag_unsafe_math_optimizations
+ && (TREE_CODE (arg0) == RDIV_EXPR || TREE_CODE (arg0) == MULT_EXPR)
+ && (TREE_CODE (arg1) == RDIV_EXPR || TREE_CODE (arg1) == MULT_EXPR)
+ && (tem = distribute_real_division (code, type, arg0, arg1)))
+ return tem;
+
+ /* Convert x+x into x*2.0. */
+ if (operand_equal_p (arg0, arg1, 0)
+ && SCALAR_FLOAT_TYPE_P (type))
+ return fold_build2 (MULT_EXPR, type, arg0,
+ build_real (type, dconst2));
+
+ /* Convert a + (b*c + d*e) into (a + b*c) + d*e.
+ We associate floats only if the user has specified
+ -fassociative-math. */
+ if (flag_associative_math
+ && TREE_CODE (arg1) == PLUS_EXPR
+ && TREE_CODE (arg0) != MULT_EXPR)
+ {
+ tree tree10 = TREE_OPERAND (arg1, 0);
+ tree tree11 = TREE_OPERAND (arg1, 1);
+ if (TREE_CODE (tree11) == MULT_EXPR
+ && TREE_CODE (tree10) == MULT_EXPR)
+ {
+ tree tree0;
+ tree0 = fold_build2 (PLUS_EXPR, type, arg0, tree10);
+ return fold_build2 (PLUS_EXPR, type, tree0, tree11);
+ }
+ }
+ /* Convert (b*c + d*e) + a into b*c + (d*e +a).
+ We associate floats only if the user has specified
+ -fassociative-math. */
+ if (flag_associative_math
+ && TREE_CODE (arg0) == PLUS_EXPR
+ && TREE_CODE (arg1) != MULT_EXPR)
+ {
+ tree tree00 = TREE_OPERAND (arg0, 0);
+ tree tree01 = TREE_OPERAND (arg0, 1);
+ if (TREE_CODE (tree01) == MULT_EXPR
+ && TREE_CODE (tree00) == MULT_EXPR)
+ {
+ tree tree0;
+ tree0 = fold_build2 (PLUS_EXPR, type, tree01, arg1);
+ return fold_build2 (PLUS_EXPR, type, tree00, tree0);
+ }
+ }
+ }
+
+ bit_rotate:
+ /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
+ is a rotate of A by C1 bits. */
+ /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
+ is a rotate of A by B bits. */
+ {
+ enum tree_code code0, code1;
+ tree rtype;
+ code0 = TREE_CODE (arg0);
+ code1 = TREE_CODE (arg1);
+ if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
+ || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
+ && operand_equal_p (TREE_OPERAND (arg0, 0),
+ TREE_OPERAND (arg1, 0), 0)
+ && (rtype = TREE_TYPE (TREE_OPERAND (arg0, 0)),
+ TYPE_UNSIGNED (rtype))
+ /* Only create rotates in complete modes. Other cases are not
+ expanded properly. */
+ && TYPE_PRECISION (rtype) == GET_MODE_PRECISION (TYPE_MODE (rtype)))
+ {
+ tree tree01, tree11;
+ enum tree_code code01, code11;
+
+ tree01 = TREE_OPERAND (arg0, 1);
+ tree11 = TREE_OPERAND (arg1, 1);
+ STRIP_NOPS (tree01);
+ STRIP_NOPS (tree11);
+ code01 = TREE_CODE (tree01);
+ code11 = TREE_CODE (tree11);
+ if (code01 == INTEGER_CST
+ && code11 == INTEGER_CST
+ && TREE_INT_CST_HIGH (tree01) == 0
+ && TREE_INT_CST_HIGH (tree11) == 0
+ && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
+ == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
+ return build2 (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
+ code0 == LSHIFT_EXPR ? tree01 : tree11);
+ else if (code11 == MINUS_EXPR)
+ {
+ tree tree110, tree111;
+ tree110 = TREE_OPERAND (tree11, 0);
+ tree111 = TREE_OPERAND (tree11, 1);
+ STRIP_NOPS (tree110);
+ STRIP_NOPS (tree111);
+ if (TREE_CODE (tree110) == INTEGER_CST
+ && 0 == compare_tree_int (tree110,
+ TYPE_PRECISION
+ (TREE_TYPE (TREE_OPERAND
+ (arg0, 0))))
+ && operand_equal_p (tree01, tree111, 0))
+ return build2 ((code0 == LSHIFT_EXPR
+ ? LROTATE_EXPR
+ : RROTATE_EXPR),
+ type, TREE_OPERAND (arg0, 0), tree01);
+ }
+ else if (code01 == MINUS_EXPR)
+ {
+ tree tree010, tree011;
+ tree010 = TREE_OPERAND (tree01, 0);
+ tree011 = TREE_OPERAND (tree01, 1);
+ STRIP_NOPS (tree010);
+ STRIP_NOPS (tree011);
+ if (TREE_CODE (tree010) == INTEGER_CST
+ && 0 == compare_tree_int (tree010,
+ TYPE_PRECISION
+ (TREE_TYPE (TREE_OPERAND
+ (arg0, 0))))
+ && operand_equal_p (tree11, tree011, 0))
+ return build2 ((code0 != LSHIFT_EXPR
+ ? LROTATE_EXPR
+ : RROTATE_EXPR),
+ type, TREE_OPERAND (arg0, 0), tree11);
+ }
+ }
+ }
+
+ associate:
+ /* In most languages, can't associate operations on floats through
+ parentheses. Rather than remember where the parentheses were, we
+ don't associate floats at all, unless the user has specified
+ -fassociative-math.
+ And, we need to make sure type is not saturating. */
+
+ if ((! FLOAT_TYPE_P (type) || flag_associative_math)
+ && !TYPE_SATURATING (type))
+ {
+ tree var0, con0, lit0, minus_lit0;
+ tree var1, con1, lit1, minus_lit1;
+ bool ok = true;
+
+ /* Split both trees into variables, constants, and literals. Then
+ associate each group together, the constants with literals,
+ then the result with variables. This increases the chances of
+ literals being recombined later and of generating relocatable
+ expressions for the sum of a constant and literal. */
+ var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
+ var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
+ code == MINUS_EXPR);
+
+ /* With undefined overflow we can only associate constants
+ with one variable. */
+ if (((POINTER_TYPE_P (type) && POINTER_TYPE_OVERFLOW_UNDEFINED)
+ || (INTEGRAL_TYPE_P (type) && !TYPE_OVERFLOW_WRAPS (type)))
+ && var0 && var1)
+ {
+ tree tmp0 = var0;
+ tree tmp1 = var1;
+
+ if (TREE_CODE (tmp0) == NEGATE_EXPR)
+ tmp0 = TREE_OPERAND (tmp0, 0);
+ if (TREE_CODE (tmp1) == NEGATE_EXPR)
+ tmp1 = TREE_OPERAND (tmp1, 0);
+ /* The only case we can still associate with two variables
+ is if they are the same, modulo negation. */
+ if (!operand_equal_p (tmp0, tmp1, 0))
+ ok = false;
+ }
+
+ /* Only do something if we found more than two objects. Otherwise,
+ nothing has changed and we risk infinite recursion. */
+ if (ok
+ && (2 < ((var0 != 0) + (var1 != 0)
+ + (con0 != 0) + (con1 != 0)
+ + (lit0 != 0) + (lit1 != 0)
+ + (minus_lit0 != 0) + (minus_lit1 != 0))))
+ {
+ /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
+ if (code == MINUS_EXPR)
+ code = PLUS_EXPR;
+
+ var0 = associate_trees (var0, var1, code, type);
+ con0 = associate_trees (con0, con1, code, type);
+ lit0 = associate_trees (lit0, lit1, code, type);
+ minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
+
+ /* Preserve the MINUS_EXPR if the negative part of the literal is
+ greater than the positive part. Otherwise, the multiplicative
+ folding code (i.e extract_muldiv) may be fooled in case
+ unsigned constants are subtracted, like in the following
+ example: ((X*2 + 4) - 8U)/2. */
+ if (minus_lit0 && lit0)
+ {
+ if (TREE_CODE (lit0) == INTEGER_CST
+ && TREE_CODE (minus_lit0) == INTEGER_CST
+ && tree_int_cst_lt (lit0, minus_lit0))
+ {
+ minus_lit0 = associate_trees (minus_lit0, lit0,
+ MINUS_EXPR, type);
+ lit0 = 0;
+ }
+ else
+ {
+ lit0 = associate_trees (lit0, minus_lit0,
+ MINUS_EXPR, type);
+ minus_lit0 = 0;
+ }
+ }
+ if (minus_lit0)
+ {
+ if (con0 == 0)
+ return fold_convert (type,
+ associate_trees (var0, minus_lit0,
+ MINUS_EXPR, type));
+ else
+ {
+ con0 = associate_trees (con0, minus_lit0,
+ MINUS_EXPR, type);
+ return fold_convert (type,
+ associate_trees (var0, con0,
+ PLUS_EXPR, type));
+ }
+ }
+
+ con0 = associate_trees (con0, lit0, code, type);
+ return fold_convert (type, associate_trees (var0, con0,
+ code, type));
+ }
+ }
+
+ return NULL_TREE;
+
+ case MINUS_EXPR:
+ /* Pointer simplifications for subtraction, simple reassociations. */
+ if (POINTER_TYPE_P (TREE_TYPE (arg1)) && POINTER_TYPE_P (TREE_TYPE (arg0)))
+ {
+ /* (PTR0 p+ A) - (PTR1 p+ B) -> (PTR0 - PTR1) + (A - B) */
+ if (TREE_CODE (arg0) == POINTER_PLUS_EXPR
+ && TREE_CODE (arg1) == POINTER_PLUS_EXPR)
+ {
+ tree arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
+ tree arg01 = fold_convert (type, TREE_OPERAND (arg0, 1));
+ tree arg10 = fold_convert (type, TREE_OPERAND (arg1, 0));
+ tree arg11 = fold_convert (type, TREE_OPERAND (arg1, 1));
+ return fold_build2 (PLUS_EXPR, type,
+ fold_build2 (MINUS_EXPR, type, arg00, arg10),
+ fold_build2 (MINUS_EXPR, type, arg01, arg11));
+ }
+ /* (PTR0 p+ A) - PTR1 -> (PTR0 - PTR1) + A, assuming PTR0 - PTR1 simplifies. */
+ else if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
+ {
+ tree arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
+ tree arg01 = fold_convert (type, TREE_OPERAND (arg0, 1));
+ tree tmp = fold_binary (MINUS_EXPR, type, arg00, fold_convert (type, arg1));
+ if (tmp)
+ return fold_build2 (PLUS_EXPR, type, tmp, arg01);
+ }
+ }
+ /* A - (-B) -> A + B */
+ if (TREE_CODE (arg1) == NEGATE_EXPR)
+ return fold_build2 (PLUS_EXPR, type, op0,
+ fold_convert (type, TREE_OPERAND (arg1, 0)));
+ /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
+ if (TREE_CODE (arg0) == NEGATE_EXPR
+ && (FLOAT_TYPE_P (type)
+ || INTEGRAL_TYPE_P (type))
+ && negate_expr_p (arg1)
+ && reorder_operands_p (arg0, arg1))
+ return fold_build2 (MINUS_EXPR, type,
+ fold_convert (type, negate_expr (arg1)),
+ fold_convert (type, TREE_OPERAND (arg0, 0)));
+ /* Convert -A - 1 to ~A. */
+ if (INTEGRAL_TYPE_P (type)
+ && TREE_CODE (arg0) == NEGATE_EXPR
+ && integer_onep (arg1)
+ && !TYPE_OVERFLOW_TRAPS (type))
+ return fold_build1 (BIT_NOT_EXPR, type,
+ fold_convert (type, TREE_OPERAND (arg0, 0)));
+
+ /* Convert -1 - A to ~A. */
+ if (INTEGRAL_TYPE_P (type)
+ && integer_all_onesp (arg0))
+ return fold_build1 (BIT_NOT_EXPR, type, op1);
+
+
+ /* X - (X / CST) * CST is X % CST. */
+ if (INTEGRAL_TYPE_P (type)
+ && TREE_CODE (arg1) == MULT_EXPR
+ && TREE_CODE (TREE_OPERAND (arg1, 0)) == TRUNC_DIV_EXPR
+ && operand_equal_p (arg0,
+ TREE_OPERAND (TREE_OPERAND (arg1, 0), 0), 0)
+ && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg1, 0), 1),
+ TREE_OPERAND (arg1, 1), 0))
+ return fold_convert (type,
+ fold_build2 (TRUNC_MOD_EXPR, TREE_TYPE (arg0),
+ arg0, TREE_OPERAND (arg1, 1)));
+
+ if (! FLOAT_TYPE_P (type))
+ {
+ if (integer_zerop (arg0))
+ return negate_expr (fold_convert (type, arg1));
+ if (integer_zerop (arg1))
+ return non_lvalue (fold_convert (type, arg0));
+
+ /* Fold A - (A & B) into ~B & A. */
+ if (!TREE_SIDE_EFFECTS (arg0)
+ && TREE_CODE (arg1) == BIT_AND_EXPR)
+ {
+ if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
+ {
+ tree arg10 = fold_convert (type, TREE_OPERAND (arg1, 0));
+ return fold_build2 (BIT_AND_EXPR, type,
+ fold_build1 (BIT_NOT_EXPR, type, arg10),
+ fold_convert (type, arg0));
+ }
+ if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
+ {
+ tree arg11 = fold_convert (type, TREE_OPERAND (arg1, 1));
+ return fold_build2 (BIT_AND_EXPR, type,
+ fold_build1 (BIT_NOT_EXPR, type, arg11),
+ fold_convert (type, arg0));
+ }
+ }
+
+ /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
+ any power of 2 minus 1. */
+ if (TREE_CODE (arg0) == BIT_AND_EXPR
+ && TREE_CODE (arg1) == BIT_AND_EXPR
+ && operand_equal_p (TREE_OPERAND (arg0, 0),
+ TREE_OPERAND (arg1, 0), 0))
+ {
+ tree mask0 = TREE_OPERAND (arg0, 1);
+ tree mask1 = TREE_OPERAND (arg1, 1);
+ tree tem = fold_build1 (BIT_NOT_EXPR, type, mask0);
+
+ if (operand_equal_p (tem, mask1, 0))
+ {
+ tem = fold_build2 (BIT_XOR_EXPR, type,
+ TREE_OPERAND (arg0, 0), mask1);
+ return fold_build2 (MINUS_EXPR, type, tem, mask1);
+ }
+ }
+ }
+
+ /* See if ARG1 is zero and X - ARG1 reduces to X. */
+ else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
+ return non_lvalue (fold_convert (type, arg0));
+
+ /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
+ ARG0 is zero and X + ARG0 reduces to X, since that would mean
+ (-ARG1 + ARG0) reduces to -ARG1. */
+ else if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
+ return negate_expr (fold_convert (type, arg1));
+
+ /* Fold __complex__ ( x, 0 ) - __complex__ ( 0, y ) to
+ __complex__ ( x, -y ). This is not the same for SNaNs or if
+ signed zeros are involved. */
+ if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
+ && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
+ && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0)))
+ {
+ tree rtype = TREE_TYPE (TREE_TYPE (arg0));
+ tree arg0r = fold_unary (REALPART_EXPR, rtype, arg0);
+ tree arg0i = fold_unary (IMAGPART_EXPR, rtype, arg0);
+ bool arg0rz = false, arg0iz = false;
+ if ((arg0r && (arg0rz = real_zerop (arg0r)))
+ || (arg0i && (arg0iz = real_zerop (arg0i))))
+ {
+ tree arg1r = fold_unary (REALPART_EXPR, rtype, arg1);
+ tree arg1i = fold_unary (IMAGPART_EXPR, rtype, arg1);
+ if (arg0rz && arg1i && real_zerop (arg1i))
+ {
+ tree rp = fold_build1 (NEGATE_EXPR, rtype,
+ arg1r ? arg1r
+ : build1 (REALPART_EXPR, rtype, arg1));
+ tree ip = arg0i ? arg0i
+ : build1 (IMAGPART_EXPR, rtype, arg0);
+ return fold_build2 (COMPLEX_EXPR, type, rp, ip);
+ }
+ else if (arg0iz && arg1r && real_zerop (arg1r))
+ {
+ tree rp = arg0r ? arg0r
+ : build1 (REALPART_EXPR, rtype, arg0);
+ tree ip = fold_build1 (NEGATE_EXPR, rtype,
+ arg1i ? arg1i
+ : build1 (IMAGPART_EXPR, rtype, arg1));
+ return fold_build2 (COMPLEX_EXPR, type, rp, ip);
+ }
+ }
+ }
+
+ /* Fold &x - &x. This can happen from &x.foo - &x.
+ This is unsafe for certain floats even in non-IEEE formats.
+ In IEEE, it is unsafe because it does wrong for NaNs.
+ Also note that operand_equal_p is always false if an operand
+ is volatile. */
+
+ if ((!FLOAT_TYPE_P (type) || !HONOR_NANS (TYPE_MODE (type)))
+ && operand_equal_p (arg0, arg1, 0))
+ return fold_convert (type, integer_zero_node);
+
+ /* A - B -> A + (-B) if B is easily negatable. */
+ if (negate_expr_p (arg1)
+ && ((FLOAT_TYPE_P (type)
+ /* Avoid this transformation if B is a positive REAL_CST. */
+ && (TREE_CODE (arg1) != REAL_CST
+ || REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1))))
+ || INTEGRAL_TYPE_P (type)))
+ return fold_build2 (PLUS_EXPR, type,
+ fold_convert (type, arg0),
+ fold_convert (type, negate_expr (arg1)));
+
+ /* Try folding difference of addresses. */
+ {
+ HOST_WIDE_INT diff;
+
+ if ((TREE_CODE (arg0) == ADDR_EXPR
+ || TREE_CODE (arg1) == ADDR_EXPR)
+ && ptr_difference_const (arg0, arg1, &diff))
+ return build_int_cst_type (type, diff);
+ }
+
+ /* Fold &a[i] - &a[j] to i-j. */
+ if (TREE_CODE (arg0) == ADDR_EXPR
+ && TREE_CODE (TREE_OPERAND (arg0, 0)) == ARRAY_REF
+ && TREE_CODE (arg1) == ADDR_EXPR
+ && TREE_CODE (TREE_OPERAND (arg1, 0)) == ARRAY_REF)
+ {
+ tree aref0 = TREE_OPERAND (arg0, 0);
+ tree aref1 = TREE_OPERAND (arg1, 0);
+ if (operand_equal_p (TREE_OPERAND (aref0, 0),
+ TREE_OPERAND (aref1, 0), 0))
+ {
+ tree op0 = fold_convert (type, TREE_OPERAND (aref0, 1));
+ tree op1 = fold_convert (type, TREE_OPERAND (aref1, 1));
+ tree esz = array_ref_element_size (aref0);
+ tree diff = build2 (MINUS_EXPR, type, op0, op1);
+ return fold_build2 (MULT_EXPR, type, diff,
+ fold_convert (type, esz));
+
+ }
+ }
+
+ if (flag_unsafe_math_optimizations
+ && (TREE_CODE (arg0) == RDIV_EXPR || TREE_CODE (arg0) == MULT_EXPR)
+ && (TREE_CODE (arg1) == RDIV_EXPR || TREE_CODE (arg1) == MULT_EXPR)
+ && (tem = distribute_real_division (code, type, arg0, arg1)))
+ return tem;
+
+ /* Handle (A1 * C1) - (A2 * C2) with A1, A2 or C1, C2 being the
+ same or one. Make sure type is not saturating.
+ fold_plusminus_mult_expr will re-associate. */
+ if ((TREE_CODE (arg0) == MULT_EXPR
+ || TREE_CODE (arg1) == MULT_EXPR)
+ && !TYPE_SATURATING (type)
+ && (!FLOAT_TYPE_P (type) || flag_associative_math))
+ {
+ tree tem = fold_plusminus_mult_expr (code, type, arg0, arg1);
+ if (tem)
+ return tem;
+ }
+
+ goto associate;
+
+ case MULT_EXPR:
+ /* (-A) * (-B) -> A * B */
+ if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
+ return fold_build2 (MULT_EXPR, type,
+ fold_convert (type, TREE_OPERAND (arg0, 0)),
+ fold_convert (type, negate_expr (arg1)));
+ if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
+ return fold_build2 (MULT_EXPR, type,
+ fold_convert (type, negate_expr (arg0)),
+ fold_convert (type, TREE_OPERAND (arg1, 0)));
+
+ if (! FLOAT_TYPE_P (type))
+ {
+ if (integer_zerop (arg1))
+ return omit_one_operand (type, arg1, arg0);
+ if (integer_onep (arg1))
+ return non_lvalue (fold_convert (type, arg0));
+ /* Transform x * -1 into -x. Make sure to do the negation
+ on the original operand with conversions not stripped
+ because we can only strip non-sign-changing conversions. */
+ if (integer_all_onesp (arg1))
+ return fold_convert (type, negate_expr (op0));
+ /* Transform x * -C into -x * C if x is easily negatable. */
+ if (TREE_CODE (arg1) == INTEGER_CST
+ && tree_int_cst_sgn (arg1) == -1
+ && negate_expr_p (arg0)
+ && (tem = negate_expr (arg1)) != arg1
+ && !TREE_OVERFLOW (tem))
+ return fold_build2 (MULT_EXPR, type,
+ fold_convert (type, negate_expr (arg0)), tem);
+
+ /* (a * (1 << b)) is (a << b) */
+ if (TREE_CODE (arg1) == LSHIFT_EXPR
+ && integer_onep (TREE_OPERAND (arg1, 0)))
+ return fold_build2 (LSHIFT_EXPR, type, op0,
+ TREE_OPERAND (arg1, 1));
+ if (TREE_CODE (arg0) == LSHIFT_EXPR
+ && integer_onep (TREE_OPERAND (arg0, 0)))
+ return fold_build2 (LSHIFT_EXPR, type, op1,
+ TREE_OPERAND (arg0, 1));
+
+ /* (A + A) * C -> A * 2 * C */
+ if (TREE_CODE (arg0) == PLUS_EXPR
+ && TREE_CODE (arg1) == INTEGER_CST
+ && operand_equal_p (TREE_OPERAND (arg0, 0),
+ TREE_OPERAND (arg0, 1), 0))
+ return fold_build2 (MULT_EXPR, type,
+ omit_one_operand (type, TREE_OPERAND (arg0, 0),
+ TREE_OPERAND (arg0, 1)),
+ fold_build2 (MULT_EXPR, type,
+ build_int_cst (type, 2) , arg1));
+
+ strict_overflow_p = false;
+ if (TREE_CODE (arg1) == INTEGER_CST
+ && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
+ &strict_overflow_p)))
+ {
+ if (strict_overflow_p)
+ fold_overflow_warning (("assuming signed overflow does not "
+ "occur when simplifying "
+ "multiplication"),
+ WARN_STRICT_OVERFLOW_MISC);
+ return fold_convert (type, tem);
+ }
+
+ /* Optimize z * conj(z) for integer complex numbers. */
+ if (TREE_CODE (arg0) == CONJ_EXPR
+ && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
+ return fold_mult_zconjz (type, arg1);
+ if (TREE_CODE (arg1) == CONJ_EXPR
+ && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
+ return fold_mult_zconjz (type, arg0);
+ }
+ else
+ {
+ /* Maybe fold x * 0 to 0. The expressions aren't the same
+ when x is NaN, since x * 0 is also NaN. Nor are they the
+ same in modes with signed zeros, since multiplying a
+ negative value by 0 gives -0, not +0. */
+ if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
+ && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
+ && real_zerop (arg1))
+ return omit_one_operand (type, arg1, arg0);
+ /* In IEEE floating point, x*1 is not equivalent to x for snans. */
+ if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
+ && real_onep (arg1))
+ return non_lvalue (fold_convert (type, arg0));
+
+ /* Transform x * -1.0 into -x. */
+ if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
+ && real_minus_onep (arg1))
+ return fold_convert (type, negate_expr (arg0));
+
+ /* Convert (C1/X)*C2 into (C1*C2)/X. This transformation may change
+ the result for floating point types due to rounding so it is applied
+ only if -fassociative-math was specify. */
+ if (flag_associative_math
+ && TREE_CODE (arg0) == RDIV_EXPR
+ && TREE_CODE (arg1) == REAL_CST
+ && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST)
+ {
+ tree tem = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 0),
+ arg1, 0);
+ if (tem)
+ return fold_build2 (RDIV_EXPR, type, tem,
+ TREE_OPERAND (arg0, 1));
+ }
+
+ /* Strip sign operations from X in X*X, i.e. -Y*-Y -> Y*Y. */
+ if (operand_equal_p (arg0, arg1, 0))
+ {
+ tree tem = fold_strip_sign_ops (arg0);
+ if (tem != NULL_TREE)
+ {
+ tem = fold_convert (type, tem);
+ return fold_build2 (MULT_EXPR, type, tem, tem);
+ }
+ }
+
+ /* Fold z * +-I to __complex__ (-+__imag z, +-__real z).
+ This is not the same for NaNs or if signed zeros are
+ involved. */
+ if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
+ && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
+ && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0))
+ && TREE_CODE (arg1) == COMPLEX_CST
+ && real_zerop (TREE_REALPART (arg1)))
+ {
+ tree rtype = TREE_TYPE (TREE_TYPE (arg0));
+ if (real_onep (TREE_IMAGPART (arg1)))
+ return fold_build2 (COMPLEX_EXPR, type,
+ negate_expr (fold_build1 (IMAGPART_EXPR,
+ rtype, arg0)),
+ fold_build1 (REALPART_EXPR, rtype, arg0));
+ else if (real_minus_onep (TREE_IMAGPART (arg1)))
+ return fold_build2 (COMPLEX_EXPR, type,
+ fold_build1 (IMAGPART_EXPR, rtype, arg0),
+ negate_expr (fold_build1 (REALPART_EXPR,
+ rtype, arg0)));
+ }
+
+ /* Optimize z * conj(z) for floating point complex numbers.
+ Guarded by flag_unsafe_math_optimizations as non-finite
+ imaginary components don't produce scalar results. */
+ if (flag_unsafe_math_optimizations
+ && TREE_CODE (arg0) == CONJ_EXPR
+ && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
+ return fold_mult_zconjz (type, arg1);
+ if (flag_unsafe_math_optimizations
+ && TREE_CODE (arg1) == CONJ_EXPR
+ && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
+ return fold_mult_zconjz (type, arg0);
+
+ if (flag_unsafe_math_optimizations)
+ {
+ enum built_in_function fcode0 = builtin_mathfn_code (arg0);
+ enum built_in_function fcode1 = builtin_mathfn_code (arg1);
+
+ /* Optimizations of root(...)*root(...). */
+ if (fcode0 == fcode1 && BUILTIN_ROOT_P (fcode0))
+ {
+ tree rootfn, arg;
+ tree arg00 = CALL_EXPR_ARG (arg0, 0);
+ tree arg10 = CALL_EXPR_ARG (arg1, 0);
+
+ /* Optimize sqrt(x)*sqrt(x) as x. */
+ if (BUILTIN_SQRT_P (fcode0)
+ && operand_equal_p (arg00, arg10, 0)
+ && ! HONOR_SNANS (TYPE_MODE (type)))
+ return arg00;
+
+ /* Optimize root(x)*root(y) as root(x*y). */
+ rootfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
+ arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
+ return build_call_expr (rootfn, 1, arg);
+ }
+
+ /* Optimize expN(x)*expN(y) as expN(x+y). */
+ if (fcode0 == fcode1 && BUILTIN_EXPONENT_P (fcode0))
+ {
+ tree expfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
+ tree arg = fold_build2 (PLUS_EXPR, type,
+ CALL_EXPR_ARG (arg0, 0),
+ CALL_EXPR_ARG (arg1, 0));
+ return build_call_expr (expfn, 1, arg);
+ }
+
+ /* Optimizations of pow(...)*pow(...). */
+ if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
+ || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
+ || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
+ {
+ tree arg00 = CALL_EXPR_ARG (arg0, 0);
+ tree arg01 = CALL_EXPR_ARG (arg0, 1);
+ tree arg10 = CALL_EXPR_ARG (arg1, 0);
+ tree arg11 = CALL_EXPR_ARG (arg1, 1);
+
+ /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
+ if (operand_equal_p (arg01, arg11, 0))
+ {
+ tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
+ tree arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
+ return build_call_expr (powfn, 2, arg, arg01);
+ }
+
+ /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
+ if (operand_equal_p (arg00, arg10, 0))
+ {
+ tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
+ tree arg = fold_build2 (PLUS_EXPR, type, arg01, arg11);
+ return build_call_expr (powfn, 2, arg00, arg);
+ }
+ }
+
+ /* Optimize tan(x)*cos(x) as sin(x). */
+ if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
+ || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
+ || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
+ || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
+ || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
+ || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
+ && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
+ CALL_EXPR_ARG (arg1, 0), 0))
+ {
+ tree sinfn = mathfn_built_in (type, BUILT_IN_SIN);
+
+ if (sinfn != NULL_TREE)
+ return build_call_expr (sinfn, 1, CALL_EXPR_ARG (arg0, 0));
+ }
+
+ /* Optimize x*pow(x,c) as pow(x,c+1). */
+ if (fcode1 == BUILT_IN_POW
+ || fcode1 == BUILT_IN_POWF
+ || fcode1 == BUILT_IN_POWL)
+ {
+ tree arg10 = CALL_EXPR_ARG (arg1, 0);
+ tree arg11 = CALL_EXPR_ARG (arg1, 1);
+ if (TREE_CODE (arg11) == REAL_CST
+ && !TREE_OVERFLOW (arg11)
+ && operand_equal_p (arg0, arg10, 0))
+ {
+ tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
+ REAL_VALUE_TYPE c;
+ tree arg;
+
+ c = TREE_REAL_CST (arg11);
+ real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
+ arg = build_real (type, c);
+ return build_call_expr (powfn, 2, arg0, arg);
+ }
+ }
+
+ /* Optimize pow(x,c)*x as pow(x,c+1). */
+ if (fcode0 == BUILT_IN_POW
+ || fcode0 == BUILT_IN_POWF
+ || fcode0 == BUILT_IN_POWL)
+ {
+ tree arg00 = CALL_EXPR_ARG (arg0, 0);
+ tree arg01 = CALL_EXPR_ARG (arg0, 1);
+ if (TREE_CODE (arg01) == REAL_CST
+ && !TREE_OVERFLOW (arg01)
+ && operand_equal_p (arg1, arg00, 0))
+ {
+ tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
+ REAL_VALUE_TYPE c;
+ tree arg;
+
+ c = TREE_REAL_CST (arg01);
+ real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
+ arg = build_real (type, c);
+ return build_call_expr (powfn, 2, arg1, arg);
+ }
+ }
+
+ /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
+ if (optimize_function_for_speed_p (cfun)
+ && operand_equal_p (arg0, arg1, 0))
+ {
+ tree powfn = mathfn_built_in (type, BUILT_IN_POW);
+
+ if (powfn)
+ {
+ tree arg = build_real (type, dconst2);
+ return build_call_expr (powfn, 2, arg0, arg);
+ }
+ }
+ }
+ }
+ goto associate;
+
+ case BIT_IOR_EXPR:
+ bit_ior:
+ if (integer_all_onesp (arg1))
+ return omit_one_operand (type, arg1, arg0);
+ if (integer_zerop (arg1))
+ return non_lvalue (fold_convert (type, arg0));
+ if (operand_equal_p (arg0, arg1, 0))
+ return non_lvalue (fold_convert (type, arg0));
+
+ /* ~X | X is -1. */
+ if (TREE_CODE (arg0) == BIT_NOT_EXPR
+ && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
+ {
+ t1 = fold_convert (type, integer_zero_node);
+ t1 = fold_unary (BIT_NOT_EXPR, type, t1);
+ return omit_one_operand (type, t1, arg1);
+ }
+
+ /* X | ~X is -1. */
+ if (TREE_CODE (arg1) == BIT_NOT_EXPR
+ && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
+ {
+ t1 = fold_convert (type, integer_zero_node);
+ t1 = fold_unary (BIT_NOT_EXPR, type, t1);
+ return omit_one_operand (type, t1, arg0);
+ }
+
+ /* Canonicalize (X & C1) | C2. */
+ if (TREE_CODE (arg0) == BIT_AND_EXPR
+ && TREE_CODE (arg1) == INTEGER_CST
+ && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
+ {
+ unsigned HOST_WIDE_INT hi1, lo1, hi2, lo2, hi3, lo3, mlo, mhi;
+ int width = TYPE_PRECISION (type), w;
+ hi1 = TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1));
+ lo1 = TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1));
+ hi2 = TREE_INT_CST_HIGH (arg1);
+ lo2 = TREE_INT_CST_LOW (arg1);
+
+ /* If (C1&C2) == C1, then (X&C1)|C2 becomes (X,C2). */
+ if ((hi1 & hi2) == hi1 && (lo1 & lo2) == lo1)
+ return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
+
+ if (width > HOST_BITS_PER_WIDE_INT)
+ {
+ mhi = (unsigned HOST_WIDE_INT) -1
+ >> (2 * HOST_BITS_PER_WIDE_INT - width);
+ mlo = -1;
+ }
+ else
+ {
+ mhi = 0;
+ mlo = (unsigned HOST_WIDE_INT) -1
+ >> (HOST_BITS_PER_WIDE_INT - width);
+ }
+
+ /* If (C1|C2) == ~0 then (X&C1)|C2 becomes X|C2. */
+ if ((~(hi1 | hi2) & mhi) == 0 && (~(lo1 | lo2) & mlo) == 0)
+ return fold_build2 (BIT_IOR_EXPR, type,
+ TREE_OPERAND (arg0, 0), arg1);
+
+ /* Minimize the number of bits set in C1, i.e. C1 := C1 & ~C2,
+ unless (C1 & ~C2) | (C2 & C3) for some C3 is a mask of some
+ mode which allows further optimizations. */
+ hi1 &= mhi;
+ lo1 &= mlo;
+ hi2 &= mhi;
+ lo2 &= mlo;
+ hi3 = hi1 & ~hi2;
+ lo3 = lo1 & ~lo2;
+ for (w = BITS_PER_UNIT;
+ w <= width && w <= HOST_BITS_PER_WIDE_INT;
+ w <<= 1)
+ {
+ unsigned HOST_WIDE_INT mask
+ = (unsigned HOST_WIDE_INT) -1 >> (HOST_BITS_PER_WIDE_INT - w);
+ if (((lo1 | lo2) & mask) == mask
+ && (lo1 & ~mask) == 0 && hi1 == 0)
+ {
+ hi3 = 0;
+ lo3 = mask;
+ break;
+ }
+ }
+ if (hi3 != hi1 || lo3 != lo1)
+ return fold_build2 (BIT_IOR_EXPR, type,
+ fold_build2 (BIT_AND_EXPR, type,
+ TREE_OPERAND (arg0, 0),
+ build_int_cst_wide (type,
+ lo3, hi3)),
+ arg1);
+ }
+
+ /* (X & Y) | Y is (X, Y). */
+ if (TREE_CODE (arg0) == BIT_AND_EXPR
+ && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
+ return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
+ /* (X & Y) | X is (Y, X). */
+ if (TREE_CODE (arg0) == BIT_AND_EXPR
+ && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
+ && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
+ return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
+ /* X | (X & Y) is (Y, X). */
+ if (TREE_CODE (arg1) == BIT_AND_EXPR
+ && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
+ && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
+ return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
+ /* X | (Y & X) is (Y, X). */
+ if (TREE_CODE (arg1) == BIT_AND_EXPR
+ && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
+ && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
+ return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
+
+ t1 = distribute_bit_expr (code, type, arg0, arg1);
+ if (t1 != NULL_TREE)
+ return t1;
+
+ /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
+
+ This results in more efficient code for machines without a NAND
+ instruction. Combine will canonicalize to the first form
+ which will allow use of NAND instructions provided by the
+ backend if they exist. */
+ if (TREE_CODE (arg0) == BIT_NOT_EXPR
+ && TREE_CODE (arg1) == BIT_NOT_EXPR)
+ {
+ return fold_build1 (BIT_NOT_EXPR, type,
+ build2 (BIT_AND_EXPR, type,
+ fold_convert (type,
+ TREE_OPERAND (arg0, 0)),
+ fold_convert (type,
+ TREE_OPERAND (arg1, 0))));
+ }
+
+ /* See if this can be simplified into a rotate first. If that
+ is unsuccessful continue in the association code. */
+ goto bit_rotate;
+
+ case BIT_XOR_EXPR:
+ if (integer_zerop (arg1))
+ return non_lvalue (fold_convert (type, arg0));
+ if (integer_all_onesp (arg1))
+ return fold_build1 (BIT_NOT_EXPR, type, op0);
+ if (operand_equal_p (arg0, arg1, 0))
+ return omit_one_operand (type, integer_zero_node, arg0);
+
+ /* ~X ^ X is -1. */
+ if (TREE_CODE (arg0) == BIT_NOT_EXPR
+ && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
+ {
+ t1 = fold_convert (type, integer_zero_node);
+ t1 = fold_unary (BIT_NOT_EXPR, type, t1);
+ return omit_one_operand (type, t1, arg1);
+ }
+
+ /* X ^ ~X is -1. */
+ if (TREE_CODE (arg1) == BIT_NOT_EXPR
+ && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
+ {
+ t1 = fold_convert (type, integer_zero_node);
+ t1 = fold_unary (BIT_NOT_EXPR, type, t1);
+ return omit_one_operand (type, t1, arg0);
+ }
+
+ /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
+ with a constant, and the two constants have no bits in common,
+ we should treat this as a BIT_IOR_EXPR since this may produce more
+ simplifications. */
+ if (TREE_CODE (arg0) == BIT_AND_EXPR
+ && TREE_CODE (arg1) == BIT_AND_EXPR
+ && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
+ && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
+ && integer_zerop (const_binop (BIT_AND_EXPR,
+ TREE_OPERAND (arg0, 1),
+ TREE_OPERAND (arg1, 1), 0)))
+ {
+ code = BIT_IOR_EXPR;
+ goto bit_ior;
+ }
+
+ /* (X | Y) ^ X -> Y & ~ X*/
+ if (TREE_CODE (arg0) == BIT_IOR_EXPR
+ && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
+ {
+ tree t2 = TREE_OPERAND (arg0, 1);
+ t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1),
+ arg1);
+ t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
+ fold_convert (type, t1));
+ return t1;
+ }
+
+ /* (Y | X) ^ X -> Y & ~ X*/
+ if (TREE_CODE (arg0) == BIT_IOR_EXPR
+ && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
+ {
+ tree t2 = TREE_OPERAND (arg0, 0);
+ t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1),
+ arg1);
+ t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
+ fold_convert (type, t1));
+ return t1;
+ }
+
+ /* X ^ (X | Y) -> Y & ~ X*/
+ if (TREE_CODE (arg1) == BIT_IOR_EXPR
+ && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
+ {
+ tree t2 = TREE_OPERAND (arg1, 1);
+ t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg0),
+ arg0);
+ t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
+ fold_convert (type, t1));
+ return t1;
+ }
+
+ /* X ^ (Y | X) -> Y & ~ X*/
+ if (TREE_CODE (arg1) == BIT_IOR_EXPR
+ && operand_equal_p (TREE_OPERAND (arg1, 1), arg0, 0))
+ {
+ tree t2 = TREE_OPERAND (arg1, 0);
+ t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg0),
+ arg0);
+ t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
+ fold_convert (type, t1));
+ return t1;
+ }
+
+ /* Convert ~X ^ ~Y to X ^ Y. */
+ if (TREE_CODE (arg0) == BIT_NOT_EXPR
+ && TREE_CODE (arg1) == BIT_NOT_EXPR)
+ return fold_build2 (code, type,
+ fold_convert (type, TREE_OPERAND (arg0, 0)),
+ fold_convert (type, TREE_OPERAND (arg1, 0)));
+
+ /* Convert ~X ^ C to X ^ ~C. */
+ if (TREE_CODE (arg0) == BIT_NOT_EXPR
+ && TREE_CODE (arg1) == INTEGER_CST)
+ return fold_build2 (code, type,
+ fold_convert (type, TREE_OPERAND (arg0, 0)),
+ fold_build1 (BIT_NOT_EXPR, type, arg1));
+
+ /* Fold (X & 1) ^ 1 as (X & 1) == 0. */
+ if (TREE_CODE (arg0) == BIT_AND_EXPR
+ && integer_onep (TREE_OPERAND (arg0, 1))
+ && integer_onep (arg1))
+ return fold_build2 (EQ_EXPR, type, arg0,
+ build_int_cst (TREE_TYPE (arg0), 0));
+
+ /* Fold (X & Y) ^ Y as ~X & Y. */
+ if (TREE_CODE (arg0) == BIT_AND_EXPR
+ && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
+ {
+ tem = fold_convert (type, TREE_OPERAND (arg0, 0));
+ return fold_build2 (BIT_AND_EXPR, type,
+ fold_build1 (BIT_NOT_EXPR, type, tem),
+ fold_convert (type, arg1));
+ }
+ /* Fold (X & Y) ^ X as ~Y & X. */
+ if (TREE_CODE (arg0) == BIT_AND_EXPR
+ && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
+ && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
+ {
+ tem = fold_convert (type, TREE_OPERAND (arg0, 1));
+ return fold_build2 (BIT_AND_EXPR, type,
+ fold_build1 (BIT_NOT_EXPR, type, tem),
+ fold_convert (type, arg1));
+ }
+ /* Fold X ^ (X & Y) as X & ~Y. */
+ if (TREE_CODE (arg1) == BIT_AND_EXPR
+ && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
+ {
+ tem = fold_convert (type, TREE_OPERAND (arg1, 1));
+ return fold_build2 (BIT_AND_EXPR, type,
+ fold_convert (type, arg0),
+ fold_build1 (BIT_NOT_EXPR, type, tem));
+ }
+ /* Fold X ^ (Y & X) as ~Y & X. */
+ if (TREE_CODE (arg1) == BIT_AND_EXPR
+ && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
+ && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
+ {
+ tem = fold_convert (type, TREE_OPERAND (arg1, 0));
+ return fold_build2 (BIT_AND_EXPR, type,
+ fold_build1 (BIT_NOT_EXPR, type, tem),
+ fold_convert (type, arg0));
+ }
+
+ /* See if this can be simplified into a rotate first. If that
+ is unsuccessful continue in the association code. */
+ goto bit_rotate;
+
+ case BIT_AND_EXPR:
+ if (integer_all_onesp (arg1))
+ return non_lvalue (fold_convert (type, arg0));
+ if (integer_zerop (arg1))
+ return omit_one_operand (type, arg1, arg0);
+ if (operand_equal_p (arg0, arg1, 0))
+ return non_lvalue (fold_convert (type, arg0));
+
+ /* ~X & X is always zero. */
+ if (TREE_CODE (arg0) == BIT_NOT_EXPR
+ && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
+ return omit_one_operand (type, integer_zero_node, arg1);
+
+ /* X & ~X is always zero. */
+ if (TREE_CODE (arg1) == BIT_NOT_EXPR
+ && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
+ return omit_one_operand (type, integer_zero_node, arg0);
+
+ /* Canonicalize (X | C1) & C2 as (X & C2) | (C1 & C2). */
+ if (TREE_CODE (arg0) == BIT_IOR_EXPR
+ && TREE_CODE (arg1) == INTEGER_CST
+ && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
+ {
+ tree tmp1 = fold_convert (type, arg1);
+ tree tmp2 = fold_convert (type, TREE_OPERAND (arg0, 0));
+ tree tmp3 = fold_convert (type, TREE_OPERAND (arg0, 1));
+ tmp2 = fold_build2 (BIT_AND_EXPR, type, tmp2, tmp1);
+ tmp3 = fold_build2 (BIT_AND_EXPR, type, tmp3, tmp1);
+ return fold_convert (type,
+ fold_build2 (BIT_IOR_EXPR, type, tmp2, tmp3));
+ }
+
+ /* (X | Y) & Y is (X, Y). */
+ if (TREE_CODE (arg0) == BIT_IOR_EXPR
+ && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
+ return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
+ /* (X | Y) & X is (Y, X). */
+ if (TREE_CODE (arg0) == BIT_IOR_EXPR
+ && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
+ && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
+ return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
+ /* X & (X | Y) is (Y, X). */
+ if (TREE_CODE (arg1) == BIT_IOR_EXPR
+ && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
+ && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
+ return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
+ /* X & (Y | X) is (Y, X). */
+ if (TREE_CODE (arg1) == BIT_IOR_EXPR
+ && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
+ && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
+ return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
+
+ /* Fold (X ^ 1) & 1 as (X & 1) == 0. */
+ if (TREE_CODE (arg0) == BIT_XOR_EXPR
+ && integer_onep (TREE_OPERAND (arg0, 1))
+ && integer_onep (arg1))
+ {
+ tem = TREE_OPERAND (arg0, 0);
+ return fold_build2 (EQ_EXPR, type,
+ fold_build2 (BIT_AND_EXPR, TREE_TYPE (tem), tem,
+ build_int_cst (TREE_TYPE (tem), 1)),
+ build_int_cst (TREE_TYPE (tem), 0));
+ }
+ /* Fold ~X & 1 as (X & 1) == 0. */
+ if (TREE_CODE (arg0) == BIT_NOT_EXPR
+ && integer_onep (arg1))
+ {
+ tem = TREE_OPERAND (arg0, 0);
+ return fold_build2 (EQ_EXPR, type,
+ fold_build2 (BIT_AND_EXPR, TREE_TYPE (tem), tem,
+ build_int_cst (TREE_TYPE (tem), 1)),
+ build_int_cst (TREE_TYPE (tem), 0));
+ }
+
+ /* Fold (X ^ Y) & Y as ~X & Y. */
+ if (TREE_CODE (arg0) == BIT_XOR_EXPR
+ && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
+ {
+ tem = fold_convert (type, TREE_OPERAND (arg0, 0));
+ return fold_build2 (BIT_AND_EXPR, type,
+ fold_build1 (BIT_NOT_EXPR, type, tem),
+ fold_convert (type, arg1));
+ }
+ /* Fold (X ^ Y) & X as ~Y & X. */
+ if (TREE_CODE (arg0) == BIT_XOR_EXPR
+ && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
+ && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
+ {
+ tem = fold_convert (type, TREE_OPERAND (arg0, 1));
+ return fold_build2 (BIT_AND_EXPR, type,
+ fold_build1 (BIT_NOT_EXPR, type, tem),
+ fold_convert (type, arg1));
+ }
+ /* Fold X & (X ^ Y) as X & ~Y. */
+ if (TREE_CODE (arg1) == BIT_XOR_EXPR
+ && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
+ {
+ tem = fold_convert (type, TREE_OPERAND (arg1, 1));
+ return fold_build2 (BIT_AND_EXPR, type,
+ fold_convert (type, arg0),
+ fold_build1 (BIT_NOT_EXPR, type, tem));
+ }
+ /* Fold X & (Y ^ X) as ~Y & X. */
+ if (TREE_CODE (arg1) == BIT_XOR_EXPR
+ && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
+ && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
+ {
+ tem = fold_convert (type, TREE_OPERAND (arg1, 0));
+ return fold_build2 (BIT_AND_EXPR, type,
+ fold_build1 (BIT_NOT_EXPR, type, tem),
+ fold_convert (type, arg0));
+ }
+
+ t1 = distribute_bit_expr (code, type, arg0, arg1);
+ if (t1 != NULL_TREE)
+ return t1;
+ /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
+ if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
+ && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
+ {
+ unsigned int prec
+ = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
+
+ if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
+ && (~TREE_INT_CST_LOW (arg1)
+ & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
+ return fold_convert (type, TREE_OPERAND (arg0, 0));
+ }
+
+ /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
+
+ This results in more efficient code for machines without a NOR
+ instruction. Combine will canonicalize to the first form
+ which will allow use of NOR instructions provided by the
+ backend if they exist. */
+ if (TREE_CODE (arg0) == BIT_NOT_EXPR
+ && TREE_CODE (arg1) == BIT_NOT_EXPR)
+ {
+ return fold_build1 (BIT_NOT_EXPR, type,
+ build2 (BIT_IOR_EXPR, type,
+ fold_convert (type,
+ TREE_OPERAND (arg0, 0)),
+ fold_convert (type,
+ TREE_OPERAND (arg1, 0))));
+ }
+
+ /* If arg0 is derived from the address of an object or function, we may
+ be able to fold this expression using the object or function's
+ alignment. */
+ if (POINTER_TYPE_P (TREE_TYPE (arg0)) && host_integerp (arg1, 1))
+ {
+ unsigned HOST_WIDE_INT modulus, residue;
+ unsigned HOST_WIDE_INT low = TREE_INT_CST_LOW (arg1);
+
+ modulus = get_pointer_modulus_and_residue (arg0, &residue);
+
+ /* This works because modulus is a power of 2. If this weren't the
+ case, we'd have to replace it by its greatest power-of-2
+ divisor: modulus & -modulus. */
+ if (low < modulus)
+ return build_int_cst (type, residue & low);
+ }
+
+ /* Fold (X << C1) & C2 into (X << C1) & (C2 | ((1 << C1) - 1))
+ (X >> C1) & C2 into (X >> C1) & (C2 | ~((type) -1 >> C1))
+ if the new mask might be further optimized. */
+ if ((TREE_CODE (arg0) == LSHIFT_EXPR
+ || TREE_CODE (arg0) == RSHIFT_EXPR)
+ && host_integerp (TREE_OPERAND (arg0, 1), 1)
+ && host_integerp (arg1, TYPE_UNSIGNED (TREE_TYPE (arg1)))
+ && tree_low_cst (TREE_OPERAND (arg0, 1), 1)
+ < TYPE_PRECISION (TREE_TYPE (arg0))
+ && TYPE_PRECISION (TREE_TYPE (arg0)) <= HOST_BITS_PER_WIDE_INT
+ && tree_low_cst (TREE_OPERAND (arg0, 1), 1) > 0)
+ {
+ unsigned int shiftc = tree_low_cst (TREE_OPERAND (arg0, 1), 1);
+ unsigned HOST_WIDE_INT mask
+ = tree_low_cst (arg1, TYPE_UNSIGNED (TREE_TYPE (arg1)));
+ unsigned HOST_WIDE_INT newmask, zerobits = 0;
+ tree shift_type = TREE_TYPE (arg0);
+
+ if (TREE_CODE (arg0) == LSHIFT_EXPR)
+ zerobits = ((((unsigned HOST_WIDE_INT) 1) << shiftc) - 1);
+ else if (TREE_CODE (arg0) == RSHIFT_EXPR
+ && TYPE_PRECISION (TREE_TYPE (arg0))
+ == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg0))))
+ {
+ unsigned int prec = TYPE_PRECISION (TREE_TYPE (arg0));
+ tree arg00 = TREE_OPERAND (arg0, 0);
+ /* See if more bits can be proven as zero because of
+ zero extension. */
+ if (TREE_CODE (arg00) == NOP_EXPR
+ && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg00, 0))))
+ {
+ tree inner_type = TREE_TYPE (TREE_OPERAND (arg00, 0));
+ if (TYPE_PRECISION (inner_type)
+ == GET_MODE_BITSIZE (TYPE_MODE (inner_type))
+ && TYPE_PRECISION (inner_type) < prec)
+ {
+ prec = TYPE_PRECISION (inner_type);
+ /* See if we can shorten the right shift. */
+ if (shiftc < prec)
+ shift_type = inner_type;
+ }
+ }
+ zerobits = ~(unsigned HOST_WIDE_INT) 0;
+ zerobits >>= HOST_BITS_PER_WIDE_INT - shiftc;
+ zerobits <<= prec - shiftc;
+ /* For arithmetic shift if sign bit could be set, zerobits
+ can contain actually sign bits, so no transformation is
+ possible, unless MASK masks them all away. In that
+ case the shift needs to be converted into logical shift. */
+ if (!TYPE_UNSIGNED (TREE_TYPE (arg0))
+ && prec == TYPE_PRECISION (TREE_TYPE (arg0)))
+ {
+ if ((mask & zerobits) == 0)
+ shift_type = unsigned_type_for (TREE_TYPE (arg0));
+ else
+ zerobits = 0;
+ }
+ }
+
+ /* ((X << 16) & 0xff00) is (X, 0). */
+ if ((mask & zerobits) == mask)
+ return omit_one_operand (type, build_int_cst (type, 0), arg0);
+
+ newmask = mask | zerobits;
+ if (newmask != mask && (newmask & (newmask + 1)) == 0)
+ {
+ unsigned int prec;
+
+ /* Only do the transformation if NEWMASK is some integer
+ mode's mask. */
+ for (prec = BITS_PER_UNIT;
+ prec < HOST_BITS_PER_WIDE_INT; prec <<= 1)
+ if (newmask == (((unsigned HOST_WIDE_INT) 1) << prec) - 1)
+ break;
+ if (prec < HOST_BITS_PER_WIDE_INT
+ || newmask == ~(unsigned HOST_WIDE_INT) 0)
+ {
+ tree newmaskt;
+
+ if (shift_type != TREE_TYPE (arg0))
+ {
+ tem = fold_build2 (TREE_CODE (arg0), shift_type,
+ fold_convert (shift_type,
+ TREE_OPERAND (arg0, 0)),
+ TREE_OPERAND (arg0, 1));
+ tem = fold_convert (type, tem);
+ }
+ else
+ tem = op0;
+ newmaskt = build_int_cst_type (TREE_TYPE (op1), newmask);
+ if (!tree_int_cst_equal (newmaskt, arg1))
+ return fold_build2 (BIT_AND_EXPR, type, tem, newmaskt);
+ }
+ }
+ }
+
+ goto associate;
+
+ case RDIV_EXPR:
+ /* Don't touch a floating-point divide by zero unless the mode
+ of the constant can represent infinity. */
+ if (TREE_CODE (arg1) == REAL_CST
+ && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
+ && real_zerop (arg1))
+ return NULL_TREE;
+
+ /* Optimize A / A to 1.0 if we don't care about
+ NaNs or Infinities. Skip the transformation
+ for non-real operands. */
+ if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (arg0))
+ && ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
+ && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg0)))
+ && operand_equal_p (arg0, arg1, 0))
+ {
+ tree r = build_real (TREE_TYPE (arg0), dconst1);
+
+ return omit_two_operands (type, r, arg0, arg1);
+ }
+
+ /* The complex version of the above A / A optimization. */
+ if (COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0))
+ && operand_equal_p (arg0, arg1, 0))
+ {
+ tree elem_type = TREE_TYPE (TREE_TYPE (arg0));
+ if (! HONOR_NANS (TYPE_MODE (elem_type))
+ && ! HONOR_INFINITIES (TYPE_MODE (elem_type)))
+ {
+ tree r = build_real (elem_type, dconst1);
+ /* omit_two_operands will call fold_convert for us. */
+ return omit_two_operands (type, r, arg0, arg1);
+ }
+ }
+
+ /* (-A) / (-B) -> A / B */
+ if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
+ return fold_build2 (RDIV_EXPR, type,
+ TREE_OPERAND (arg0, 0),
+ negate_expr (arg1));
+ if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
+ return fold_build2 (RDIV_EXPR, type,
+ negate_expr (arg0),
+ TREE_OPERAND (arg1, 0));
+
+ /* In IEEE floating point, x/1 is not equivalent to x for snans. */
+ if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
+ && real_onep (arg1))
+ return non_lvalue (fold_convert (type, arg0));
+
+ /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
+ if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
+ && real_minus_onep (arg1))
+ return non_lvalue (fold_convert (type, negate_expr (arg0)));
+
+ /* If ARG1 is a constant, we can convert this to a multiply by the
+ reciprocal. This does not have the same rounding properties,
+ so only do this if -freciprocal-math. We can actually
+ always safely do it if ARG1 is a power of two, but it's hard to
+ tell if it is or not in a portable manner. */
+ if (TREE_CODE (arg1) == REAL_CST)
+ {
+ if (flag_reciprocal_math
+ && 0 != (tem = const_binop (code, build_real (type, dconst1),
+ arg1, 0)))
+ return fold_build2 (MULT_EXPR, type, arg0, tem);
+ /* Find the reciprocal if optimizing and the result is exact. */
+ if (optimize)
+ {
+ REAL_VALUE_TYPE r;
+ r = TREE_REAL_CST (arg1);
+ if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
+ {
+ tem = build_real (type, r);
+ return fold_build2 (MULT_EXPR, type,
+ fold_convert (type, arg0), tem);
+ }
+ }
+ }
+ /* Convert A/B/C to A/(B*C). */
+ if (flag_reciprocal_math
+ && TREE_CODE (arg0) == RDIV_EXPR)
+ return fold_build2 (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
+ fold_build2 (MULT_EXPR, type,
+ TREE_OPERAND (arg0, 1), arg1));
+
+ /* Convert A/(B/C) to (A/B)*C. */
+ if (flag_reciprocal_math
+ && TREE_CODE (arg1) == RDIV_EXPR)
+ return fold_build2 (MULT_EXPR, type,
+ fold_build2 (RDIV_EXPR, type, arg0,
+ TREE_OPERAND (arg1, 0)),
+ TREE_OPERAND (arg1, 1));
+
+ /* Convert C1/(X*C2) into (C1/C2)/X. */
+ if (flag_reciprocal_math
+ && TREE_CODE (arg1) == MULT_EXPR
+ && TREE_CODE (arg0) == REAL_CST
+ && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
+ {
+ tree tem = const_binop (RDIV_EXPR, arg0,
+ TREE_OPERAND (arg1, 1), 0);
+ if (tem)
+ return fold_build2 (RDIV_EXPR, type, tem,
+ TREE_OPERAND (arg1, 0));
+ }
+
+ if (flag_unsafe_math_optimizations)
+ {
+ enum built_in_function fcode0 = builtin_mathfn_code (arg0);
+ enum built_in_function fcode1 = builtin_mathfn_code (arg1);
+
+ /* Optimize sin(x)/cos(x) as tan(x). */
+ if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
+ || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
+ || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
+ && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
+ CALL_EXPR_ARG (arg1, 0), 0))
+ {
+ tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
+
+ if (tanfn != NULL_TREE)
+ return build_call_expr (tanfn, 1, CALL_EXPR_ARG (arg0, 0));
+ }
+
+ /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
+ if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
+ || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
+ || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
+ && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
+ CALL_EXPR_ARG (arg1, 0), 0))
+ {
+ tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
+
+ if (tanfn != NULL_TREE)
+ {
+ tree tmp = build_call_expr (tanfn, 1, CALL_EXPR_ARG (arg0, 0));
+ return fold_build2 (RDIV_EXPR, type,
+ build_real (type, dconst1), tmp);
+ }
+ }
+
+ /* Optimize sin(x)/tan(x) as cos(x) if we don't care about
+ NaNs or Infinities. */
+ if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_TAN)
+ || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_TANF)
+ || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_TANL)))
+ {
+ tree arg00 = CALL_EXPR_ARG (arg0, 0);
+ tree arg01 = CALL_EXPR_ARG (arg1, 0);
+
+ if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00)))
+ && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00)))
+ && operand_equal_p (arg00, arg01, 0))
+ {
+ tree cosfn = mathfn_built_in (type, BUILT_IN_COS);
+
+ if (cosfn != NULL_TREE)
+ return build_call_expr (cosfn, 1, arg00);
+ }
+ }
+
+ /* Optimize tan(x)/sin(x) as 1.0/cos(x) if we don't care about
+ NaNs or Infinities. */
+ if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_SIN)
+ || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_SINF)
+ || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_SINL)))
+ {
+ tree arg00 = CALL_EXPR_ARG (arg0, 0);
+ tree arg01 = CALL_EXPR_ARG (arg1, 0);
+
+ if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00)))
+ && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00)))
+ && operand_equal_p (arg00, arg01, 0))
+ {
+ tree cosfn = mathfn_built_in (type, BUILT_IN_COS);
+
+ if (cosfn != NULL_TREE)
+ {
+ tree tmp = build_call_expr (cosfn, 1, arg00);
+ return fold_build2 (RDIV_EXPR, type,
+ build_real (type, dconst1),
+ tmp);
+ }
+ }
+ }
+
+ /* Optimize pow(x,c)/x as pow(x,c-1). */
+ if (fcode0 == BUILT_IN_POW
+ || fcode0 == BUILT_IN_POWF
+ || fcode0 == BUILT_IN_POWL)
+ {
+ tree arg00 = CALL_EXPR_ARG (arg0, 0);
+ tree arg01 = CALL_EXPR_ARG (arg0, 1);
+ if (TREE_CODE (arg01) == REAL_CST
+ && !TREE_OVERFLOW (arg01)
+ && operand_equal_p (arg1, arg00, 0))
+ {
+ tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
+ REAL_VALUE_TYPE c;
+ tree arg;
+
+ c = TREE_REAL_CST (arg01);
+ real_arithmetic (&c, MINUS_EXPR, &c, &dconst1);
+ arg = build_real (type, c);
+ return build_call_expr (powfn, 2, arg1, arg);
+ }
+ }
+
+ /* Optimize a/root(b/c) into a*root(c/b). */
+ if (BUILTIN_ROOT_P (fcode1))
+ {
+ tree rootarg = CALL_EXPR_ARG (arg1, 0);
+
+ if (TREE_CODE (rootarg) == RDIV_EXPR)
+ {
+ tree rootfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
+ tree b = TREE_OPERAND (rootarg, 0);
+ tree c = TREE_OPERAND (rootarg, 1);
+
+ tree tmp = fold_build2 (RDIV_EXPR, type, c, b);
+
+ tmp = build_call_expr (rootfn, 1, tmp);
+ return fold_build2 (MULT_EXPR, type, arg0, tmp);
+ }
+ }
+
+ /* Optimize x/expN(y) into x*expN(-y). */
+ if (BUILTIN_EXPONENT_P (fcode1))
+ {
+ tree expfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
+ tree arg = negate_expr (CALL_EXPR_ARG (arg1, 0));
+ arg1 = build_call_expr (expfn, 1, fold_convert (type, arg));
+ return fold_build2 (MULT_EXPR, type, arg0, arg1);
+ }
+
+ /* Optimize x/pow(y,z) into x*pow(y,-z). */
+ if (fcode1 == BUILT_IN_POW
+ || fcode1 == BUILT_IN_POWF
+ || fcode1 == BUILT_IN_POWL)
+ {
+ tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
+ tree arg10 = CALL_EXPR_ARG (arg1, 0);
+ tree arg11 = CALL_EXPR_ARG (arg1, 1);
+ tree neg11 = fold_convert (type, negate_expr (arg11));
+ arg1 = build_call_expr (powfn, 2, arg10, neg11);
+ return fold_build2 (MULT_EXPR, type, arg0, arg1);
+ }
+ }
+ return NULL_TREE;
+
+ case TRUNC_DIV_EXPR:
+ case FLOOR_DIV_EXPR:
+ /* Simplify A / (B << N) where A and B are positive and B is
+ a power of 2, to A >> (N + log2(B)). */
+ strict_overflow_p = false;
+ if (TREE_CODE (arg1) == LSHIFT_EXPR
+ && (TYPE_UNSIGNED (type)
+ || tree_expr_nonnegative_warnv_p (op0, &strict_overflow_p)))
+ {
+ tree sval = TREE_OPERAND (arg1, 0);
+ if (integer_pow2p (sval) && tree_int_cst_sgn (sval) > 0)
+ {
+ tree sh_cnt = TREE_OPERAND (arg1, 1);
+ unsigned long pow2 = exact_log2 (TREE_INT_CST_LOW (sval));
+
+ if (strict_overflow_p)
+ fold_overflow_warning (("assuming signed overflow does not "
+ "occur when simplifying A / (B << N)"),
+ WARN_STRICT_OVERFLOW_MISC);
+
+ sh_cnt = fold_build2 (PLUS_EXPR, TREE_TYPE (sh_cnt),
+ sh_cnt, build_int_cst (NULL_TREE, pow2));
+ return fold_build2 (RSHIFT_EXPR, type,
+ fold_convert (type, arg0), sh_cnt);
+ }
+ }
+
+ /* For unsigned integral types, FLOOR_DIV_EXPR is the same as
+ TRUNC_DIV_EXPR. Rewrite into the latter in this case. */
+ if (INTEGRAL_TYPE_P (type)
+ && TYPE_UNSIGNED (type)
+ && code == FLOOR_DIV_EXPR)
+ return fold_build2 (TRUNC_DIV_EXPR, type, op0, op1);
+
+ /* Fall thru */
+
+ case ROUND_DIV_EXPR:
+ case CEIL_DIV_EXPR:
+ case EXACT_DIV_EXPR:
+ if (integer_onep (arg1))
+ return non_lvalue (fold_convert (type, arg0));
+ if (integer_zerop (arg1))
+ return NULL_TREE;
+ /* X / -1 is -X. */
+ if (!TYPE_UNSIGNED (type)
+ && TREE_CODE (arg1) == INTEGER_CST
+ && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
+ && TREE_INT_CST_HIGH (arg1) == -1)
+ return fold_convert (type, negate_expr (arg0));
+
+ /* Convert -A / -B to A / B when the type is signed and overflow is
+ undefined. */
+ if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
+ && TREE_CODE (arg0) == NEGATE_EXPR
+ && negate_expr_p (arg1))
+ {
+ if (INTEGRAL_TYPE_P (type))
+ fold_overflow_warning (("assuming signed overflow does not occur "
+ "when distributing negation across "
+ "division"),
+ WARN_STRICT_OVERFLOW_MISC);
+ return fold_build2 (code, type,
+ fold_convert (type, TREE_OPERAND (arg0, 0)),
+ fold_convert (type, negate_expr (arg1)));
+ }
+ if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
+ && TREE_CODE (arg1) == NEGATE_EXPR
+ && negate_expr_p (arg0))
+ {
+ if (INTEGRAL_TYPE_P (type))
+ fold_overflow_warning (("assuming signed overflow does not occur "
+ "when distributing negation across "
+ "division"),
+ WARN_STRICT_OVERFLOW_MISC);
+ return fold_build2 (code, type,
+ fold_convert (type, negate_expr (arg0)),
+ fold_convert (type, TREE_OPERAND (arg1, 0)));
+ }
+
+ /* If arg0 is a multiple of arg1, then rewrite to the fastest div
+ operation, EXACT_DIV_EXPR.
+
+ Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
+ At one time others generated faster code, it's not clear if they do
+ after the last round to changes to the DIV code in expmed.c. */
+ if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
+ && multiple_of_p (type, arg0, arg1))
+ return fold_build2 (EXACT_DIV_EXPR, type, arg0, arg1);
+
+ strict_overflow_p = false;
+ if (TREE_CODE (arg1) == INTEGER_CST
+ && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
+ &strict_overflow_p)))
+ {
+ if (strict_overflow_p)
+ fold_overflow_warning (("assuming signed overflow does not occur "
+ "when simplifying division"),
+ WARN_STRICT_OVERFLOW_MISC);
+ return fold_convert (type, tem);
+ }
+
+ return NULL_TREE;
+
+ case CEIL_MOD_EXPR:
+ case FLOOR_MOD_EXPR:
+ case ROUND_MOD_EXPR:
+ case TRUNC_MOD_EXPR:
+ /* X % 1 is always zero, but be sure to preserve any side
+ effects in X. */
+ if (integer_onep (arg1))
+ return omit_one_operand (type, integer_zero_node, arg0);
+
+ /* X % 0, return X % 0 unchanged so that we can get the
+ proper warnings and errors. */
+ if (integer_zerop (arg1))
+ return NULL_TREE;
+
+ /* 0 % X is always zero, but be sure to preserve any side
+ effects in X. Place this after checking for X == 0. */
+ if (integer_zerop (arg0))
+ return omit_one_operand (type, integer_zero_node, arg1);
+
+ /* X % -1 is zero. */
+ if (!TYPE_UNSIGNED (type)
+ && TREE_CODE (arg1) == INTEGER_CST
+ && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
+ && TREE_INT_CST_HIGH (arg1) == -1)
+ return omit_one_operand (type, integer_zero_node, arg0);
+
+ /* Optimize TRUNC_MOD_EXPR by a power of two into a BIT_AND_EXPR,
+ i.e. "X % C" into "X & (C - 1)", if X and C are positive. */
+ strict_overflow_p = false;
+ if ((code == TRUNC_MOD_EXPR || code == FLOOR_MOD_EXPR)
+ && (TYPE_UNSIGNED (type)
+ || tree_expr_nonnegative_warnv_p (op0, &strict_overflow_p)))
+ {
+ tree c = arg1;
+ /* Also optimize A % (C << N) where C is a power of 2,
+ to A & ((C << N) - 1). */
+ if (TREE_CODE (arg1) == LSHIFT_EXPR)
+ c = TREE_OPERAND (arg1, 0);
+
+ if (integer_pow2p (c) && tree_int_cst_sgn (c) > 0)
+ {
+ tree mask = fold_build2 (MINUS_EXPR, TREE_TYPE (arg1), arg1,
+ build_int_cst (TREE_TYPE (arg1), 1));
+ if (strict_overflow_p)
+ fold_overflow_warning (("assuming signed overflow does not "
+ "occur when simplifying "
+ "X % (power of two)"),
+ WARN_STRICT_OVERFLOW_MISC);
+ return fold_build2 (BIT_AND_EXPR, type,
+ fold_convert (type, arg0),
+ fold_convert (type, mask));
+ }
+ }
+
+ /* X % -C is the same as X % C. */
+ if (code == TRUNC_MOD_EXPR
+ && !TYPE_UNSIGNED (type)
+ && TREE_CODE (arg1) == INTEGER_CST
+ && !TREE_OVERFLOW (arg1)
+ && TREE_INT_CST_HIGH (arg1) < 0
+ && !TYPE_OVERFLOW_TRAPS (type)
+ /* Avoid this transformation if C is INT_MIN, i.e. C == -C. */
+ && !sign_bit_p (arg1, arg1))
+ return fold_build2 (code, type, fold_convert (type, arg0),
+ fold_convert (type, negate_expr (arg1)));
+
+ /* X % -Y is the same as X % Y. */
+ if (code == TRUNC_MOD_EXPR
+ && !TYPE_UNSIGNED (type)
+ && TREE_CODE (arg1) == NEGATE_EXPR
+ && !TYPE_OVERFLOW_TRAPS (type))
+ return fold_build2 (code, type, fold_convert (type, arg0),
+ fold_convert (type, TREE_OPERAND (arg1, 0)));
+
+ if (TREE_CODE (arg1) == INTEGER_CST
+ && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
+ &strict_overflow_p)))
+ {
+ if (strict_overflow_p)
+ fold_overflow_warning (("assuming signed overflow does not occur "
+ "when simplifying modulus"),
+ WARN_STRICT_OVERFLOW_MISC);
+ return fold_convert (type, tem);
+ }
+
+ return NULL_TREE;
+
+ case LROTATE_EXPR:
+ case RROTATE_EXPR:
+ if (integer_all_onesp (arg0))
+ return omit_one_operand (type, arg0, arg1);
+ goto shift;
+
+ case RSHIFT_EXPR:
+ /* Optimize -1 >> x for arithmetic right shifts. */
+ if (integer_all_onesp (arg0) && !TYPE_UNSIGNED (type)
+ && tree_expr_nonnegative_p (arg1))
+ return omit_one_operand (type, arg0, arg1);
+ /* ... fall through ... */
+
+ case LSHIFT_EXPR:
+ shift:
+ if (integer_zerop (arg1))
+ return non_lvalue (fold_convert (type, arg0));
+ if (integer_zerop (arg0))
+ return omit_one_operand (type, arg0, arg1);
+
+ /* Since negative shift count is not well-defined,
+ don't try to compute it in the compiler. */
+ if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
+ return NULL_TREE;
+
+ /* Turn (a OP c1) OP c2 into a OP (c1+c2). */
+ if (TREE_CODE (op0) == code && host_integerp (arg1, false)
+ && TREE_INT_CST_LOW (arg1) < TYPE_PRECISION (type)
+ && host_integerp (TREE_OPERAND (arg0, 1), false)
+ && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) < TYPE_PRECISION (type))
+ {
+ HOST_WIDE_INT low = (TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1))
+ + TREE_INT_CST_LOW (arg1));
+
+ /* Deal with a OP (c1 + c2) being undefined but (a OP c1) OP c2
+ being well defined. */
+ if (low >= TYPE_PRECISION (type))
+ {
+ if (code == LROTATE_EXPR || code == RROTATE_EXPR)
+ low = low % TYPE_PRECISION (type);
+ else if (TYPE_UNSIGNED (type) || code == LSHIFT_EXPR)
+ return omit_one_operand (type, build_int_cst (type, 0),
+ TREE_OPERAND (arg0, 0));
+ else
+ low = TYPE_PRECISION (type) - 1;
+ }
+
+ return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
+ build_int_cst (type, low));
+ }
+
+ /* Transform (x >> c) << c into x & (-1<<c), or transform (x << c) >> c
+ into x & ((unsigned)-1 >> c) for unsigned types. */
+ if (((code == LSHIFT_EXPR && TREE_CODE (arg0) == RSHIFT_EXPR)
+ || (TYPE_UNSIGNED (type)
+ && code == RSHIFT_EXPR && TREE_CODE (arg0) == LSHIFT_EXPR))
+ && host_integerp (arg1, false)
+ && TREE_INT_CST_LOW (arg1) < TYPE_PRECISION (type)
+ && host_integerp (TREE_OPERAND (arg0, 1), false)
+ && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) < TYPE_PRECISION (type))
+ {
+ HOST_WIDE_INT low0 = TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1));
+ HOST_WIDE_INT low1 = TREE_INT_CST_LOW (arg1);
+ tree lshift;
+ tree arg00;
+
+ if (low0 == low1)
+ {
+ arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
+
+ lshift = build_int_cst (type, -1);
+ lshift = int_const_binop (code, lshift, arg1, 0);
+
+ return fold_build2 (BIT_AND_EXPR, type, arg00, lshift);
+ }
+ }
+
+ /* Rewrite an LROTATE_EXPR by a constant into an
+ RROTATE_EXPR by a new constant. */
+ if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
+ {
+ tree tem = build_int_cst (TREE_TYPE (arg1),
+ TYPE_PRECISION (type));
+ tem = const_binop (MINUS_EXPR, tem, arg1, 0);
+ return fold_build2 (RROTATE_EXPR, type, op0, tem);
+ }
+
+ /* If we have a rotate of a bit operation with the rotate count and
+ the second operand of the bit operation both constant,
+ permute the two operations. */
+ if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
+ && (TREE_CODE (arg0) == BIT_AND_EXPR
+ || TREE_CODE (arg0) == BIT_IOR_EXPR
+ || TREE_CODE (arg0) == BIT_XOR_EXPR)
+ && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
+ return fold_build2 (TREE_CODE (arg0), type,
+ fold_build2 (code, type,
+ TREE_OPERAND (arg0, 0), arg1),
+ fold_build2 (code, type,
+ TREE_OPERAND (arg0, 1), arg1));
+
+ /* Two consecutive rotates adding up to the precision of the
+ type can be ignored. */
+ if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
+ && TREE_CODE (arg0) == RROTATE_EXPR
+ && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
+ && TREE_INT_CST_HIGH (arg1) == 0
+ && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
+ && ((TREE_INT_CST_LOW (arg1)
+ + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
+ == (unsigned int) TYPE_PRECISION (type)))
+ return TREE_OPERAND (arg0, 0);
+
+ /* Fold (X & C2) << C1 into (X << C1) & (C2 << C1)
+ (X & C2) >> C1 into (X >> C1) & (C2 >> C1)
+ if the latter can be further optimized. */
+ if ((code == LSHIFT_EXPR || code == RSHIFT_EXPR)
+ && TREE_CODE (arg0) == BIT_AND_EXPR
+ && TREE_CODE (arg1) == INTEGER_CST
+ && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
+ {
+ tree mask = fold_build2 (code, type,
+ fold_convert (type, TREE_OPERAND (arg0, 1)),
+ arg1);
+ tree shift = fold_build2 (code, type,
+ fold_convert (type, TREE_OPERAND (arg0, 0)),
+ arg1);
+ tem = fold_binary (BIT_AND_EXPR, type, shift, mask);
+ if (tem)
+ return tem;
+ }
+
+ return NULL_TREE;
+
+ case MIN_EXPR:
+ if (operand_equal_p (arg0, arg1, 0))
+ return omit_one_operand (type, arg0, arg1);
+ if (INTEGRAL_TYPE_P (type)
+ && operand_equal_p (arg1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
+ return omit_one_operand (type, arg1, arg0);
+ tem = fold_minmax (MIN_EXPR, type, arg0, arg1);
+ if (tem)
+ return tem;
+ goto associate;
+
+ case MAX_EXPR:
+ if (operand_equal_p (arg0, arg1, 0))
+ return omit_one_operand (type, arg0, arg1);
+ if (INTEGRAL_TYPE_P (type)
+ && TYPE_MAX_VALUE (type)
+ && operand_equal_p (arg1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
+ return omit_one_operand (type, arg1, arg0);
+ tem = fold_minmax (MAX_EXPR, type, arg0, arg1);
+ if (tem)
+ return tem;
+ goto associate;
+
+ case TRUTH_ANDIF_EXPR:
+ /* Note that the operands of this must be ints
+ and their values must be 0 or 1.
+ ("true" is a fixed value perhaps depending on the language.) */
+ /* If first arg is constant zero, return it. */
+ if (integer_zerop (arg0))
+ return fold_convert (type, arg0);
+ case TRUTH_AND_EXPR:
+ /* If either arg is constant true, drop it. */
+ if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
+ return non_lvalue (fold_convert (type, arg1));
+ if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
+ /* Preserve sequence points. */
+ && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
+ return non_lvalue (fold_convert (type, arg0));
+ /* If second arg is constant zero, result is zero, but first arg
+ must be evaluated. */
+ if (integer_zerop (arg1))
+ return omit_one_operand (type, arg1, arg0);
+ /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
+ case will be handled here. */
+ if (integer_zerop (arg0))
+ return omit_one_operand (type, arg0, arg1);
+
+ /* !X && X is always false. */
+ if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
+ && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
+ return omit_one_operand (type, integer_zero_node, arg1);
+ /* X && !X is always false. */
+ if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
+ && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
+ return omit_one_operand (type, integer_zero_node, arg0);
+
+ /* A < X && A + 1 > Y ==> A < X && A >= Y. Normally A + 1 > Y
+ means A >= Y && A != MAX, but in this case we know that
+ A < X <= MAX. */
+
+ if (!TREE_SIDE_EFFECTS (arg0)
+ && !TREE_SIDE_EFFECTS (arg1))
+ {
+ tem = fold_to_nonsharp_ineq_using_bound (arg0, arg1);
+ if (tem && !operand_equal_p (tem, arg0, 0))
+ return fold_build2 (code, type, tem, arg1);
+
+ tem = fold_to_nonsharp_ineq_using_bound (arg1, arg0);
+ if (tem && !operand_equal_p (tem, arg1, 0))
+ return fold_build2 (code, type, arg0, tem);
+ }
+
+ truth_andor:
+ /* We only do these simplifications if we are optimizing. */
+ if (!optimize)
+ return NULL_TREE;
+
+ /* Check for things like (A || B) && (A || C). We can convert this
+ to A || (B && C). Note that either operator can be any of the four
+ truth and/or operations and the transformation will still be
+ valid. Also note that we only care about order for the
+ ANDIF and ORIF operators. If B contains side effects, this
+ might change the truth-value of A. */
+ if (TREE_CODE (arg0) == TREE_CODE (arg1)
+ && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
+ || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
+ || TREE_CODE (arg0) == TRUTH_AND_EXPR
+ || TREE_CODE (arg0) == TRUTH_OR_EXPR)
+ && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
+ {
+ tree a00 = TREE_OPERAND (arg0, 0);
+ tree a01 = TREE_OPERAND (arg0, 1);
+ tree a10 = TREE_OPERAND (arg1, 0);
+ tree a11 = TREE_OPERAND (arg1, 1);
+ int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
+ || TREE_CODE (arg0) == TRUTH_AND_EXPR)
+ && (code == TRUTH_AND_EXPR
+ || code == TRUTH_OR_EXPR));
+
+ if (operand_equal_p (a00, a10, 0))
+ return fold_build2 (TREE_CODE (arg0), type, a00,
+ fold_build2 (code, type, a01, a11));
+ else if (commutative && operand_equal_p (a00, a11, 0))
+ return fold_build2 (TREE_CODE (arg0), type, a00,
+ fold_build2 (code, type, a01, a10));
+ else if (commutative && operand_equal_p (a01, a10, 0))
+ return fold_build2 (TREE_CODE (arg0), type, a01,
+ fold_build2 (code, type, a00, a11));
+
+ /* This case if tricky because we must either have commutative
+ operators or else A10 must not have side-effects. */
+
+ else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
+ && operand_equal_p (a01, a11, 0))
+ return fold_build2 (TREE_CODE (arg0), type,
+ fold_build2 (code, type, a00, a10),
+ a01);
+ }
+
+ /* See if we can build a range comparison. */
+ if (0 != (tem = fold_range_test (code, type, op0, op1)))
+ return tem;
+
+ /* Check for the possibility of merging component references. If our
+ lhs is another similar operation, try to merge its rhs with our
+ rhs. Then try to merge our lhs and rhs. */
+ if (TREE_CODE (arg0) == code
+ && 0 != (tem = fold_truthop (code, type,
+ TREE_OPERAND (arg0, 1), arg1)))
+ return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
+
+ if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
+ return tem;
+
+ return NULL_TREE;
+
+ case TRUTH_ORIF_EXPR:
+ /* Note that the operands of this must be ints
+ and their values must be 0 or true.
+ ("true" is a fixed value perhaps depending on the language.) */
+ /* If first arg is constant true, return it. */
+ if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
+ return fold_convert (type, arg0);
+ case TRUTH_OR_EXPR:
+ /* If either arg is constant zero, drop it. */
+ if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
+ return non_lvalue (fold_convert (type, arg1));
+ if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
+ /* Preserve sequence points. */
+ && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
+ return non_lvalue (fold_convert (type, arg0));
+ /* If second arg is constant true, result is true, but we must
+ evaluate first arg. */
+ if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
+ return omit_one_operand (type, arg1, arg0);
+ /* Likewise for first arg, but note this only occurs here for
+ TRUTH_OR_EXPR. */
+ if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
+ return omit_one_operand (type, arg0, arg1);
+
+ /* !X || X is always true. */
+ if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
+ && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
+ return omit_one_operand (type, integer_one_node, arg1);
+ /* X || !X is always true. */
+ if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
+ && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
+ return omit_one_operand (type, integer_one_node, arg0);
+
+ goto truth_andor;
+
+ case TRUTH_XOR_EXPR:
+ /* If the second arg is constant zero, drop it. */
+ if (integer_zerop (arg1))
+ return non_lvalue (fold_convert (type, arg0));
+ /* If the second arg is constant true, this is a logical inversion. */
+ if (integer_onep (arg1))
+ {
+ /* Only call invert_truthvalue if operand is a truth value. */
+ if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
+ tem = fold_build1 (TRUTH_NOT_EXPR, TREE_TYPE (arg0), arg0);
+ else
+ tem = invert_truthvalue (arg0);
+ return non_lvalue (fold_convert (type, tem));
+ }
+ /* Identical arguments cancel to zero. */
+ if (operand_equal_p (arg0, arg1, 0))
+ return omit_one_operand (type, integer_zero_node, arg0);
+
+ /* !X ^ X is always true. */
+ if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
+ && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
+ return omit_one_operand (type, integer_one_node, arg1);
+
+ /* X ^ !X is always true. */
+ if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
+ && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
+ return omit_one_operand (type, integer_one_node, arg0);
+
+ return NULL_TREE;
+
+ case EQ_EXPR:
+ case NE_EXPR:
+ tem = fold_comparison (code, type, op0, op1);
+ if (tem != NULL_TREE)
+ return tem;
+
+ /* bool_var != 0 becomes bool_var. */
+ if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
+ && code == NE_EXPR)
+ return non_lvalue (fold_convert (type, arg0));
+
+ /* bool_var == 1 becomes bool_var. */
+ if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
+ && code == EQ_EXPR)
+ return non_lvalue (fold_convert (type, arg0));
+
+ /* bool_var != 1 becomes !bool_var. */
+ if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
+ && code == NE_EXPR)
+ return fold_build1 (TRUTH_NOT_EXPR, type, fold_convert (type, arg0));
+
+ /* bool_var == 0 becomes !bool_var. */
+ if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
+ && code == EQ_EXPR)
+ return fold_build1 (TRUTH_NOT_EXPR, type, fold_convert (type, arg0));
+
+ /* If this is an equality comparison of the address of two non-weak,
+ unaliased symbols neither of which are extern (since we do not
+ have access to attributes for externs), then we know the result. */
+ if (TREE_CODE (arg0) == ADDR_EXPR
+ && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg0, 0))
+ && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
+ && ! lookup_attribute ("alias",
+ DECL_ATTRIBUTES (TREE_OPERAND (arg0, 0)))
+ && ! DECL_EXTERNAL (TREE_OPERAND (arg0, 0))
+ && TREE_CODE (arg1) == ADDR_EXPR
+ && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg1, 0))
+ && ! DECL_WEAK (TREE_OPERAND (arg1, 0))
+ && ! lookup_attribute ("alias",
+ DECL_ATTRIBUTES (TREE_OPERAND (arg1, 0)))
+ && ! DECL_EXTERNAL (TREE_OPERAND (arg1, 0)))
+ {
+ /* We know that we're looking at the address of two
+ non-weak, unaliased, static _DECL nodes.
+
+ It is both wasteful and incorrect to call operand_equal_p
+ to compare the two ADDR_EXPR nodes. It is wasteful in that
+ all we need to do is test pointer equality for the arguments
+ to the two ADDR_EXPR nodes. It is incorrect to use
+ operand_equal_p as that function is NOT equivalent to a
+ C equality test. It can in fact return false for two
+ objects which would test as equal using the C equality
+ operator. */
+ bool equal = TREE_OPERAND (arg0, 0) == TREE_OPERAND (arg1, 0);
+ return constant_boolean_node (equal
+ ? code == EQ_EXPR : code != EQ_EXPR,
+ type);
+ }
+
+ /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
+ a MINUS_EXPR of a constant, we can convert it into a comparison with
+ a revised constant as long as no overflow occurs. */
+ if (TREE_CODE (arg1) == INTEGER_CST
+ && (TREE_CODE (arg0) == PLUS_EXPR
+ || TREE_CODE (arg0) == MINUS_EXPR)
+ && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
+ && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
+ ? MINUS_EXPR : PLUS_EXPR,
+ fold_convert (TREE_TYPE (arg0), arg1),
+ TREE_OPERAND (arg0, 1), 0))
+ && !TREE_OVERFLOW (tem))
+ return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
+
+ /* Similarly for a NEGATE_EXPR. */
+ if (TREE_CODE (arg0) == NEGATE_EXPR
+ && TREE_CODE (arg1) == INTEGER_CST
+ && 0 != (tem = negate_expr (arg1))
+ && TREE_CODE (tem) == INTEGER_CST
+ && !TREE_OVERFLOW (tem))
+ return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
+
+ /* Similarly for a BIT_XOR_EXPR; X ^ C1 == C2 is X == (C1 ^ C2). */
+ if (TREE_CODE (arg0) == BIT_XOR_EXPR
+ && TREE_CODE (arg1) == INTEGER_CST
+ && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
+ return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
+ fold_build2 (BIT_XOR_EXPR, TREE_TYPE (arg0),
+ fold_convert (TREE_TYPE (arg0), arg1),
+ TREE_OPERAND (arg0, 1)));
+
+ /* Transform comparisons of the form X +- C CMP X. */
+ if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
+ && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
+ && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
+ && (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
+ || POINTER_TYPE_P (TREE_TYPE (arg0))))
+ {
+ tree cst = TREE_OPERAND (arg0, 1);
+
+ if (code == EQ_EXPR
+ && !integer_zerop (cst))
+ return omit_two_operands (type, boolean_false_node,
+ TREE_OPERAND (arg0, 0), arg1);
+ else
+ return omit_two_operands (type, boolean_true_node,
+ TREE_OPERAND (arg0, 0), arg1);
+ }
+
+ /* If we have X - Y == 0, we can convert that to X == Y and similarly
+ for !=. Don't do this for ordered comparisons due to overflow. */
+ if (TREE_CODE (arg0) == MINUS_EXPR
+ && integer_zerop (arg1))
+ return fold_build2 (code, type,
+ TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
+
+ /* Convert ABS_EXPR<x> == 0 or ABS_EXPR<x> != 0 to x == 0 or x != 0. */
+ if (TREE_CODE (arg0) == ABS_EXPR
+ && (integer_zerop (arg1) || real_zerop (arg1)))
+ return fold_build2 (code, type, TREE_OPERAND (arg0, 0), arg1);
+
+ /* If this is an EQ or NE comparison with zero and ARG0 is
+ (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
+ two operations, but the latter can be done in one less insn
+ on machines that have only two-operand insns or on which a
+ constant cannot be the first operand. */
+ if (TREE_CODE (arg0) == BIT_AND_EXPR
+ && integer_zerop (arg1))
+ {
+ tree arg00 = TREE_OPERAND (arg0, 0);
+ tree arg01 = TREE_OPERAND (arg0, 1);
+ if (TREE_CODE (arg00) == LSHIFT_EXPR
+ && integer_onep (TREE_OPERAND (arg00, 0)))
+ {
+ tree tem = fold_build2 (RSHIFT_EXPR, TREE_TYPE (arg00),
+ arg01, TREE_OPERAND (arg00, 1));
+ tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0), tem,
+ build_int_cst (TREE_TYPE (arg0), 1));
+ return fold_build2 (code, type,
+ fold_convert (TREE_TYPE (arg1), tem), arg1);
+ }
+ else if (TREE_CODE (arg01) == LSHIFT_EXPR
+ && integer_onep (TREE_OPERAND (arg01, 0)))
+ {
+ tree tem = fold_build2 (RSHIFT_EXPR, TREE_TYPE (arg01),
+ arg00, TREE_OPERAND (arg01, 1));
+ tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0), tem,
+ build_int_cst (TREE_TYPE (arg0), 1));
+ return fold_build2 (code, type,
+ fold_convert (TREE_TYPE (arg1), tem), arg1);
+ }
+ }
+
+ /* If this is an NE or EQ comparison of zero against the result of a
+ signed MOD operation whose second operand is a power of 2, make
+ the MOD operation unsigned since it is simpler and equivalent. */
+ if (integer_zerop (arg1)
+ && !TYPE_UNSIGNED (TREE_TYPE (arg0))
+ && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
+ || TREE_CODE (arg0) == CEIL_MOD_EXPR
+ || TREE_CODE (arg0) == FLOOR_MOD_EXPR
+ || TREE_CODE (arg0) == ROUND_MOD_EXPR)
+ && integer_pow2p (TREE_OPERAND (arg0, 1)))
+ {
+ tree newtype = unsigned_type_for (TREE_TYPE (arg0));
+ tree newmod = fold_build2 (TREE_CODE (arg0), newtype,
+ fold_convert (newtype,
+ TREE_OPERAND (arg0, 0)),
+ fold_convert (newtype,
+ TREE_OPERAND (arg0, 1)));
+
+ return fold_build2 (code, type, newmod,
+ fold_convert (newtype, arg1));
+ }
+
+ /* Fold ((X >> C1) & C2) == 0 and ((X >> C1) & C2) != 0 where
+ C1 is a valid shift constant, and C2 is a power of two, i.e.
+ a single bit. */
+ if (TREE_CODE (arg0) == BIT_AND_EXPR
+ && TREE_CODE (TREE_OPERAND (arg0, 0)) == RSHIFT_EXPR
+ && TREE_CODE (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1))
+ == INTEGER_CST
+ && integer_pow2p (TREE_OPERAND (arg0, 1))
+ && integer_zerop (arg1))
+ {
+ tree itype = TREE_TYPE (arg0);
+ unsigned HOST_WIDE_INT prec = TYPE_PRECISION (itype);
+ tree arg001 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 1);
+
+ /* Check for a valid shift count. */
+ if (TREE_INT_CST_HIGH (arg001) == 0
+ && TREE_INT_CST_LOW (arg001) < prec)
+ {
+ tree arg01 = TREE_OPERAND (arg0, 1);
+ tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
+ unsigned HOST_WIDE_INT log2 = tree_log2 (arg01);
+ /* If (C2 << C1) doesn't overflow, then ((X >> C1) & C2) != 0
+ can be rewritten as (X & (C2 << C1)) != 0. */
+ if ((log2 + TREE_INT_CST_LOW (arg001)) < prec)
+ {
+ tem = fold_build2 (LSHIFT_EXPR, itype, arg01, arg001);
+ tem = fold_build2 (BIT_AND_EXPR, itype, arg000, tem);
+ return fold_build2 (code, type, tem, arg1);
+ }
+ /* Otherwise, for signed (arithmetic) shifts,
+ ((X >> C1) & C2) != 0 is rewritten as X < 0, and
+ ((X >> C1) & C2) == 0 is rewritten as X >= 0. */
+ else if (!TYPE_UNSIGNED (itype))
+ return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR, type,
+ arg000, build_int_cst (itype, 0));
+ /* Otherwise, of unsigned (logical) shifts,
+ ((X >> C1) & C2) != 0 is rewritten as (X,false), and
+ ((X >> C1) & C2) == 0 is rewritten as (X,true). */
+ else
+ return omit_one_operand (type,
+ code == EQ_EXPR ? integer_one_node
+ : integer_zero_node,
+ arg000);
+ }
+ }
+
+ /* If this is an NE comparison of zero with an AND of one, remove the
+ comparison since the AND will give the correct value. */
+ if (code == NE_EXPR
+ && integer_zerop (arg1)
+ && TREE_CODE (arg0) == BIT_AND_EXPR
+ && integer_onep (TREE_OPERAND (arg0, 1)))
+ return fold_convert (type, arg0);
+
+ /* If we have (A & C) == C where C is a power of 2, convert this into
+ (A & C) != 0. Similarly for NE_EXPR. */
+ if (TREE_CODE (arg0) == BIT_AND_EXPR
+ && integer_pow2p (TREE_OPERAND (arg0, 1))
+ && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
+ return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
+ arg0, fold_convert (TREE_TYPE (arg0),
+ integer_zero_node));
+
+ /* If we have (A & C) != 0 or (A & C) == 0 and C is the sign
+ bit, then fold the expression into A < 0 or A >= 0. */
+ tem = fold_single_bit_test_into_sign_test (code, arg0, arg1, type);
+ if (tem)
+ return tem;
+
+ /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
+ Similarly for NE_EXPR. */
+ if (TREE_CODE (arg0) == BIT_AND_EXPR
+ && TREE_CODE (arg1) == INTEGER_CST
+ && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
+ {
+ tree notc = fold_build1 (BIT_NOT_EXPR,
+ TREE_TYPE (TREE_OPERAND (arg0, 1)),
+ TREE_OPERAND (arg0, 1));
+ tree dandnotc = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
+ arg1, notc);
+ tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
+ if (integer_nonzerop (dandnotc))
+ return omit_one_operand (type, rslt, arg0);
+ }
+
+ /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
+ Similarly for NE_EXPR. */
+ if (TREE_CODE (arg0) == BIT_IOR_EXPR
+ && TREE_CODE (arg1) == INTEGER_CST
+ && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
+ {
+ tree notd = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1);
+ tree candnotd = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
+ TREE_OPERAND (arg0, 1), notd);
+ tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
+ if (integer_nonzerop (candnotd))
+ return omit_one_operand (type, rslt, arg0);
+ }
+
+ /* If this is a comparison of a field, we may be able to simplify it. */
+ if ((TREE_CODE (arg0) == COMPONENT_REF
+ || TREE_CODE (arg0) == BIT_FIELD_REF)
+ /* Handle the constant case even without -O
+ to make sure the warnings are given. */
+ && (optimize || TREE_CODE (arg1) == INTEGER_CST))
+ {
+ t1 = optimize_bit_field_compare (code, type, arg0, arg1);
+ if (t1)
+ return t1;
+ }
+
+ /* Optimize comparisons of strlen vs zero to a compare of the
+ first character of the string vs zero. To wit,
+ strlen(ptr) == 0 => *ptr == 0
+ strlen(ptr) != 0 => *ptr != 0
+ Other cases should reduce to one of these two (or a constant)
+ due to the return value of strlen being unsigned. */
+ if (TREE_CODE (arg0) == CALL_EXPR
+ && integer_zerop (arg1))
+ {
+ tree fndecl = get_callee_fndecl (arg0);
+
+ if (fndecl
+ && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
+ && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
+ && call_expr_nargs (arg0) == 1
+ && TREE_CODE (TREE_TYPE (CALL_EXPR_ARG (arg0, 0))) == POINTER_TYPE)
+ {
+ tree iref = build_fold_indirect_ref (CALL_EXPR_ARG (arg0, 0));
+ return fold_build2 (code, type, iref,
+ build_int_cst (TREE_TYPE (iref), 0));
+ }
+ }
+
+ /* Fold (X >> C) != 0 into X < 0 if C is one less than the width
+ of X. Similarly fold (X >> C) == 0 into X >= 0. */
+ if (TREE_CODE (arg0) == RSHIFT_EXPR
+ && integer_zerop (arg1)
+ && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
+ {
+ tree arg00 = TREE_OPERAND (arg0, 0);
+ tree arg01 = TREE_OPERAND (arg0, 1);
+ tree itype = TREE_TYPE (arg00);
+ if (TREE_INT_CST_HIGH (arg01) == 0
+ && TREE_INT_CST_LOW (arg01)
+ == (unsigned HOST_WIDE_INT) (TYPE_PRECISION (itype) - 1))
+ {
+ if (TYPE_UNSIGNED (itype))
+ {
+ itype = signed_type_for (itype);
+ arg00 = fold_convert (itype, arg00);
+ }
+ return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
+ type, arg00, build_int_cst (itype, 0));
+ }
+ }
+
+ /* (X ^ Y) == 0 becomes X == Y, and (X ^ Y) != 0 becomes X != Y. */
+ if (integer_zerop (arg1)
+ && TREE_CODE (arg0) == BIT_XOR_EXPR)
+ return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
+ TREE_OPERAND (arg0, 1));
+
+ /* (X ^ Y) == Y becomes X == 0. We know that Y has no side-effects. */
+ if (TREE_CODE (arg0) == BIT_XOR_EXPR
+ && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
+ return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
+ build_int_cst (TREE_TYPE (arg1), 0));
+ /* Likewise (X ^ Y) == X becomes Y == 0. X has no side-effects. */
+ if (TREE_CODE (arg0) == BIT_XOR_EXPR
+ && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
+ && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
+ return fold_build2 (code, type, TREE_OPERAND (arg0, 1),
+ build_int_cst (TREE_TYPE (arg1), 0));
+
+ /* (X ^ C1) op C2 can be rewritten as X op (C1 ^ C2). */
+ if (TREE_CODE (arg0) == BIT_XOR_EXPR
+ && TREE_CODE (arg1) == INTEGER_CST
+ && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
+ return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
+ fold_build2 (BIT_XOR_EXPR, TREE_TYPE (arg1),
+ TREE_OPERAND (arg0, 1), arg1));
+
+ /* Fold (~X & C) == 0 into (X & C) != 0 and (~X & C) != 0 into
+ (X & C) == 0 when C is a single bit. */
+ if (TREE_CODE (arg0) == BIT_AND_EXPR
+ && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_NOT_EXPR
+ && integer_zerop (arg1)
+ && integer_pow2p (TREE_OPERAND (arg0, 1)))
+ {
+ tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
+ TREE_OPERAND (TREE_OPERAND (arg0, 0), 0),
+ TREE_OPERAND (arg0, 1));
+ return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR,
+ type, tem, arg1);
+ }
+
+ /* Fold ((X & C) ^ C) eq/ne 0 into (X & C) ne/eq 0, when the
+ constant C is a power of two, i.e. a single bit. */
+ if (TREE_CODE (arg0) == BIT_XOR_EXPR
+ && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
+ && integer_zerop (arg1)
+ && integer_pow2p (TREE_OPERAND (arg0, 1))
+ && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
+ TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
+ {
+ tree arg00 = TREE_OPERAND (arg0, 0);
+ return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
+ arg00, build_int_cst (TREE_TYPE (arg00), 0));
+ }
+
+ /* Likewise, fold ((X ^ C) & C) eq/ne 0 into (X & C) ne/eq 0,
+ when is C is a power of two, i.e. a single bit. */
+ if (TREE_CODE (arg0) == BIT_AND_EXPR
+ && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_XOR_EXPR
+ && integer_zerop (arg1)
+ && integer_pow2p (TREE_OPERAND (arg0, 1))
+ && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
+ TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
+ {
+ tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
+ tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg000),
+ arg000, TREE_OPERAND (arg0, 1));
+ return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
+ tem, build_int_cst (TREE_TYPE (tem), 0));
+ }
+
+ if (integer_zerop (arg1)
+ && tree_expr_nonzero_p (arg0))
+ {
+ tree res = constant_boolean_node (code==NE_EXPR, type);
+ return omit_one_operand (type, res, arg0);
+ }
+
+ /* Fold -X op -Y as X op Y, where op is eq/ne. */
+ if (TREE_CODE (arg0) == NEGATE_EXPR
+ && TREE_CODE (arg1) == NEGATE_EXPR)
+ return fold_build2 (code, type,
+ TREE_OPERAND (arg0, 0),
+ TREE_OPERAND (arg1, 0));
+
+ /* Fold (X & C) op (Y & C) as (X ^ Y) & C op 0", and symmetries. */
+ if (TREE_CODE (arg0) == BIT_AND_EXPR
+ && TREE_CODE (arg1) == BIT_AND_EXPR)
+ {
+ tree arg00 = TREE_OPERAND (arg0, 0);
+ tree arg01 = TREE_OPERAND (arg0, 1);
+ tree arg10 = TREE_OPERAND (arg1, 0);
+ tree arg11 = TREE_OPERAND (arg1, 1);
+ tree itype = TREE_TYPE (arg0);
+
+ if (operand_equal_p (arg01, arg11, 0))
+ return fold_build2 (code, type,
+ fold_build2 (BIT_AND_EXPR, itype,
+ fold_build2 (BIT_XOR_EXPR, itype,
+ arg00, arg10),
+ arg01),
+ build_int_cst (itype, 0));
+
+ if (operand_equal_p (arg01, arg10, 0))
+ return fold_build2 (code, type,
+ fold_build2 (BIT_AND_EXPR, itype,
+ fold_build2 (BIT_XOR_EXPR, itype,
+ arg00, arg11),
+ arg01),
+ build_int_cst (itype, 0));
+
+ if (operand_equal_p (arg00, arg11, 0))
+ return fold_build2 (code, type,
+ fold_build2 (BIT_AND_EXPR, itype,
+ fold_build2 (BIT_XOR_EXPR, itype,
+ arg01, arg10),
+ arg00),
+ build_int_cst (itype, 0));
+
+ if (operand_equal_p (arg00, arg10, 0))
+ return fold_build2 (code, type,
+ fold_build2 (BIT_AND_EXPR, itype,
+ fold_build2 (BIT_XOR_EXPR, itype,
+ arg01, arg11),
+ arg00),
+ build_int_cst (itype, 0));
+ }
+
+ if (TREE_CODE (arg0) == BIT_XOR_EXPR
+ && TREE_CODE (arg1) == BIT_XOR_EXPR)
+ {
+ tree arg00 = TREE_OPERAND (arg0, 0);
+ tree arg01 = TREE_OPERAND (arg0, 1);
+ tree arg10 = TREE_OPERAND (arg1, 0);
+ tree arg11 = TREE_OPERAND (arg1, 1);
+ tree itype = TREE_TYPE (arg0);
+
+ /* Optimize (X ^ Z) op (Y ^ Z) as X op Y, and symmetries.
+ operand_equal_p guarantees no side-effects so we don't need
+ to use omit_one_operand on Z. */
+ if (operand_equal_p (arg01, arg11, 0))
+ return fold_build2 (code, type, arg00, arg10);
+ if (operand_equal_p (arg01, arg10, 0))
+ return fold_build2 (code, type, arg00, arg11);
+ if (operand_equal_p (arg00, arg11, 0))
+ return fold_build2 (code, type, arg01, arg10);
+ if (operand_equal_p (arg00, arg10, 0))
+ return fold_build2 (code, type, arg01, arg11);
+
+ /* Optimize (X ^ C1) op (Y ^ C2) as (X ^ (C1 ^ C2)) op Y. */
+ if (TREE_CODE (arg01) == INTEGER_CST
+ && TREE_CODE (arg11) == INTEGER_CST)
+ return fold_build2 (code, type,
+ fold_build2 (BIT_XOR_EXPR, itype, arg00,
+ fold_build2 (BIT_XOR_EXPR, itype,
+ arg01, arg11)),
+ arg10);
+ }
+
+ /* Attempt to simplify equality/inequality comparisons of complex
+ values. Only lower the comparison if the result is known or
+ can be simplified to a single scalar comparison. */
+ if ((TREE_CODE (arg0) == COMPLEX_EXPR
+ || TREE_CODE (arg0) == COMPLEX_CST)
+ && (TREE_CODE (arg1) == COMPLEX_EXPR
+ || TREE_CODE (arg1) == COMPLEX_CST))
+ {
+ tree real0, imag0, real1, imag1;
+ tree rcond, icond;
+
+ if (TREE_CODE (arg0) == COMPLEX_EXPR)
+ {
+ real0 = TREE_OPERAND (arg0, 0);
+ imag0 = TREE_OPERAND (arg0, 1);
+ }
+ else
+ {
+ real0 = TREE_REALPART (arg0);
+ imag0 = TREE_IMAGPART (arg0);
+ }
+
+ if (TREE_CODE (arg1) == COMPLEX_EXPR)
+ {
+ real1 = TREE_OPERAND (arg1, 0);
+ imag1 = TREE_OPERAND (arg1, 1);
+ }
+ else
+ {
+ real1 = TREE_REALPART (arg1);
+ imag1 = TREE_IMAGPART (arg1);
+ }
+
+ rcond = fold_binary (code, type, real0, real1);
+ if (rcond && TREE_CODE (rcond) == INTEGER_CST)
+ {
+ if (integer_zerop (rcond))
+ {
+ if (code == EQ_EXPR)
+ return omit_two_operands (type, boolean_false_node,
+ imag0, imag1);
+ return fold_build2 (NE_EXPR, type, imag0, imag1);
+ }
+ else
+ {
+ if (code == NE_EXPR)
+ return omit_two_operands (type, boolean_true_node,
+ imag0, imag1);
+ return fold_build2 (EQ_EXPR, type, imag0, imag1);
+ }
+ }
+
+ icond = fold_binary (code, type, imag0, imag1);
+ if (icond && TREE_CODE (icond) == INTEGER_CST)
+ {
+ if (integer_zerop (icond))
+ {
+ if (code == EQ_EXPR)
+ return omit_two_operands (type, boolean_false_node,
+ real0, real1);
+ return fold_build2 (NE_EXPR, type, real0, real1);
+ }
+ else
+ {
+ if (code == NE_EXPR)
+ return omit_two_operands (type, boolean_true_node,
+ real0, real1);
+ return fold_build2 (EQ_EXPR, type, real0, real1);
+ }
+ }
+ }
+
+ return NULL_TREE;
+
+ case LT_EXPR:
+ case GT_EXPR:
+ case LE_EXPR:
+ case GE_EXPR:
+ tem = fold_comparison (code, type, op0, op1);
+ if (tem != NULL_TREE)
+ return tem;
+
+ /* Transform comparisons of the form X +- C CMP X. */
+ if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
+ && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
+ && ((TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
+ && !HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0))))
+ || (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
+ && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))))
+ {
+ tree arg01 = TREE_OPERAND (arg0, 1);
+ enum tree_code code0 = TREE_CODE (arg0);
+ int is_positive;
+
+ if (TREE_CODE (arg01) == REAL_CST)
+ is_positive = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg01)) ? -1 : 1;
+ else
+ is_positive = tree_int_cst_sgn (arg01);
+
+ /* (X - c) > X becomes false. */
+ if (code == GT_EXPR
+ && ((code0 == MINUS_EXPR && is_positive >= 0)
+ || (code0 == PLUS_EXPR && is_positive <= 0)))
+ {
+ if (TREE_CODE (arg01) == INTEGER_CST
+ && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
+ fold_overflow_warning (("assuming signed overflow does not "
+ "occur when assuming that (X - c) > X "
+ "is always false"),
+ WARN_STRICT_OVERFLOW_ALL);
+ return constant_boolean_node (0, type);
+ }
+
+ /* Likewise (X + c) < X becomes false. */
+ if (code == LT_EXPR
+ && ((code0 == PLUS_EXPR && is_positive >= 0)
+ || (code0 == MINUS_EXPR && is_positive <= 0)))
+ {
+ if (TREE_CODE (arg01) == INTEGER_CST
+ && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
+ fold_overflow_warning (("assuming signed overflow does not "
+ "occur when assuming that "
+ "(X + c) < X is always false"),
+ WARN_STRICT_OVERFLOW_ALL);
+ return constant_boolean_node (0, type);
+ }
- if (TREE_CODE (arg0) == PLUS_EXPR)
- parg = arg0, marg = arg1;
+ /* Convert (X - c) <= X to true. */
+ if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
+ && code == LE_EXPR
+ && ((code0 == MINUS_EXPR && is_positive >= 0)
+ || (code0 == PLUS_EXPR && is_positive <= 0)))
+ {
+ if (TREE_CODE (arg01) == INTEGER_CST
+ && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
+ fold_overflow_warning (("assuming signed overflow does not "
+ "occur when assuming that "
+ "(X - c) <= X is always true"),
+ WARN_STRICT_OVERFLOW_ALL);
+ return constant_boolean_node (1, type);
+ }
+
+ /* Convert (X + c) >= X to true. */
+ if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
+ && code == GE_EXPR
+ && ((code0 == PLUS_EXPR && is_positive >= 0)
+ || (code0 == MINUS_EXPR && is_positive <= 0)))
+ {
+ if (TREE_CODE (arg01) == INTEGER_CST
+ && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
+ fold_overflow_warning (("assuming signed overflow does not "
+ "occur when assuming that "
+ "(X + c) >= X is always true"),
+ WARN_STRICT_OVERFLOW_ALL);
+ return constant_boolean_node (1, type);
+ }
+
+ if (TREE_CODE (arg01) == INTEGER_CST)
+ {
+ /* Convert X + c > X and X - c < X to true for integers. */
+ if (code == GT_EXPR
+ && ((code0 == PLUS_EXPR && is_positive > 0)
+ || (code0 == MINUS_EXPR && is_positive < 0)))
+ {
+ if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
+ fold_overflow_warning (("assuming signed overflow does "
+ "not occur when assuming that "
+ "(X + c) > X is always true"),
+ WARN_STRICT_OVERFLOW_ALL);
+ return constant_boolean_node (1, type);
+ }
+
+ if (code == LT_EXPR
+ && ((code0 == MINUS_EXPR && is_positive > 0)
+ || (code0 == PLUS_EXPR && is_positive < 0)))
+ {
+ if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
+ fold_overflow_warning (("assuming signed overflow does "
+ "not occur when assuming that "
+ "(X - c) < X is always true"),
+ WARN_STRICT_OVERFLOW_ALL);
+ return constant_boolean_node (1, type);
+ }
+
+ /* Convert X + c <= X and X - c >= X to false for integers. */
+ if (code == LE_EXPR
+ && ((code0 == PLUS_EXPR && is_positive > 0)
+ || (code0 == MINUS_EXPR && is_positive < 0)))
+ {
+ if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
+ fold_overflow_warning (("assuming signed overflow does "
+ "not occur when assuming that "
+ "(X + c) <= X is always false"),
+ WARN_STRICT_OVERFLOW_ALL);
+ return constant_boolean_node (0, type);
+ }
+
+ if (code == GE_EXPR
+ && ((code0 == MINUS_EXPR && is_positive > 0)
+ || (code0 == PLUS_EXPR && is_positive < 0)))
+ {
+ if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
+ fold_overflow_warning (("assuming signed overflow does "
+ "not occur when assuming that "
+ "(X - c) >= X is always false"),
+ WARN_STRICT_OVERFLOW_ALL);
+ return constant_boolean_node (0, type);
+ }
+ }
+ }
+
+ /* Comparisons with the highest or lowest possible integer of
+ the specified precision will have known values. */
+ {
+ tree arg1_type = TREE_TYPE (arg1);
+ unsigned int width = TYPE_PRECISION (arg1_type);
+
+ if (TREE_CODE (arg1) == INTEGER_CST
+ && width <= 2 * HOST_BITS_PER_WIDE_INT
+ && (INTEGRAL_TYPE_P (arg1_type) || POINTER_TYPE_P (arg1_type)))
+ {
+ HOST_WIDE_INT signed_max_hi;
+ unsigned HOST_WIDE_INT signed_max_lo;
+ unsigned HOST_WIDE_INT max_hi, max_lo, min_hi, min_lo;
+
+ if (width <= HOST_BITS_PER_WIDE_INT)
+ {
+ signed_max_lo = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
+ - 1;
+ signed_max_hi = 0;
+ max_hi = 0;
+
+ if (TYPE_UNSIGNED (arg1_type))
+ {
+ max_lo = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
+ min_lo = 0;
+ min_hi = 0;
+ }
+ else
+ {
+ max_lo = signed_max_lo;
+ min_lo = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
+ min_hi = -1;
+ }
+ }
+ else
+ {
+ width -= HOST_BITS_PER_WIDE_INT;
+ signed_max_lo = -1;
+ signed_max_hi = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
+ - 1;
+ max_lo = -1;
+ min_lo = 0;
+
+ if (TYPE_UNSIGNED (arg1_type))
+ {
+ max_hi = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
+ min_hi = 0;
+ }
+ else
+ {
+ max_hi = signed_max_hi;
+ min_hi = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
+ }
+ }
+
+ if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1) == max_hi
+ && TREE_INT_CST_LOW (arg1) == max_lo)
+ switch (code)
+ {
+ case GT_EXPR:
+ return omit_one_operand (type, integer_zero_node, arg0);
+
+ case GE_EXPR:
+ return fold_build2 (EQ_EXPR, type, op0, op1);
+
+ case LE_EXPR:
+ return omit_one_operand (type, integer_one_node, arg0);
+
+ case LT_EXPR:
+ return fold_build2 (NE_EXPR, type, op0, op1);
+
+ /* The GE_EXPR and LT_EXPR cases above are not normally
+ reached because of previous transformations. */
+
+ default:
+ break;
+ }
+ else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
+ == max_hi
+ && TREE_INT_CST_LOW (arg1) == max_lo - 1)
+ switch (code)
+ {
+ case GT_EXPR:
+ arg1 = const_binop (PLUS_EXPR, arg1,
+ build_int_cst (TREE_TYPE (arg1), 1), 0);
+ return fold_build2 (EQ_EXPR, type,
+ fold_convert (TREE_TYPE (arg1), arg0),
+ arg1);
+ case LE_EXPR:
+ arg1 = const_binop (PLUS_EXPR, arg1,
+ build_int_cst (TREE_TYPE (arg1), 1), 0);
+ return fold_build2 (NE_EXPR, type,
+ fold_convert (TREE_TYPE (arg1), arg0),
+ arg1);
+ default:
+ break;
+ }
+ else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
+ == min_hi
+ && TREE_INT_CST_LOW (arg1) == min_lo)
+ switch (code)
+ {
+ case LT_EXPR:
+ return omit_one_operand (type, integer_zero_node, arg0);
+
+ case LE_EXPR:
+ return fold_build2 (EQ_EXPR, type, op0, op1);
+
+ case GE_EXPR:
+ return omit_one_operand (type, integer_one_node, arg0);
+
+ case GT_EXPR:
+ return fold_build2 (NE_EXPR, type, op0, op1);
+
+ default:
+ break;
+ }
+ else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
+ == min_hi
+ && TREE_INT_CST_LOW (arg1) == min_lo + 1)
+ switch (code)
+ {
+ case GE_EXPR:
+ arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
+ return fold_build2 (NE_EXPR, type,
+ fold_convert (TREE_TYPE (arg1), arg0),
+ arg1);
+ case LT_EXPR:
+ arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
+ return fold_build2 (EQ_EXPR, type,
+ fold_convert (TREE_TYPE (arg1), arg0),
+ arg1);
+ default:
+ break;
+ }
+
+ else if (TREE_INT_CST_HIGH (arg1) == signed_max_hi
+ && TREE_INT_CST_LOW (arg1) == signed_max_lo
+ && TYPE_UNSIGNED (arg1_type)
+ /* We will flip the signedness of the comparison operator
+ associated with the mode of arg1, so the sign bit is
+ specified by this mode. Check that arg1 is the signed
+ max associated with this sign bit. */
+ && width == GET_MODE_BITSIZE (TYPE_MODE (arg1_type))
+ /* signed_type does not work on pointer types. */
+ && INTEGRAL_TYPE_P (arg1_type))
+ {
+ /* The following case also applies to X < signed_max+1
+ and X >= signed_max+1 because previous transformations. */
+ if (code == LE_EXPR || code == GT_EXPR)
+ {
+ tree st;
+ st = signed_type_for (TREE_TYPE (arg1));
+ return fold_build2 (code == LE_EXPR ? GE_EXPR : LT_EXPR,
+ type, fold_convert (st, arg0),
+ build_int_cst (st, 0));
+ }
+ }
+ }
+ }
+
+ /* If we are comparing an ABS_EXPR with a constant, we can
+ convert all the cases into explicit comparisons, but they may
+ well not be faster than doing the ABS and one comparison.
+ But ABS (X) <= C is a range comparison, which becomes a subtraction
+ and a comparison, and is probably faster. */
+ if (code == LE_EXPR
+ && TREE_CODE (arg1) == INTEGER_CST
+ && TREE_CODE (arg0) == ABS_EXPR
+ && ! TREE_SIDE_EFFECTS (arg0)
+ && (0 != (tem = negate_expr (arg1)))
+ && TREE_CODE (tem) == INTEGER_CST
+ && !TREE_OVERFLOW (tem))
+ return fold_build2 (TRUTH_ANDIF_EXPR, type,
+ build2 (GE_EXPR, type,
+ TREE_OPERAND (arg0, 0), tem),
+ build2 (LE_EXPR, type,
+ TREE_OPERAND (arg0, 0), arg1));
+
+ /* Convert ABS_EXPR<x> >= 0 to true. */
+ strict_overflow_p = false;
+ if (code == GE_EXPR
+ && (integer_zerop (arg1)
+ || (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
+ && real_zerop (arg1)))
+ && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
+ {
+ if (strict_overflow_p)
+ fold_overflow_warning (("assuming signed overflow does not occur "
+ "when simplifying comparison of "
+ "absolute value and zero"),
+ WARN_STRICT_OVERFLOW_CONDITIONAL);
+ return omit_one_operand (type, integer_one_node, arg0);
+ }
+
+ /* Convert ABS_EXPR<x> < 0 to false. */
+ strict_overflow_p = false;
+ if (code == LT_EXPR
+ && (integer_zerop (arg1) || real_zerop (arg1))
+ && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
+ {
+ if (strict_overflow_p)
+ fold_overflow_warning (("assuming signed overflow does not occur "
+ "when simplifying comparison of "
+ "absolute value and zero"),
+ WARN_STRICT_OVERFLOW_CONDITIONAL);
+ return omit_one_operand (type, integer_zero_node, arg0);
+ }
+
+ /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
+ and similarly for >= into !=. */
+ if ((code == LT_EXPR || code == GE_EXPR)
+ && TYPE_UNSIGNED (TREE_TYPE (arg0))
+ && TREE_CODE (arg1) == LSHIFT_EXPR
+ && integer_onep (TREE_OPERAND (arg1, 0)))
+ return build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
+ build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
+ TREE_OPERAND (arg1, 1)),
+ build_int_cst (TREE_TYPE (arg0), 0));
+
+ if ((code == LT_EXPR || code == GE_EXPR)
+ && TYPE_UNSIGNED (TREE_TYPE (arg0))
+ && CONVERT_EXPR_P (arg1)
+ && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
+ && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
+ return
+ build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
+ fold_convert (TREE_TYPE (arg0),
+ build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
+ TREE_OPERAND (TREE_OPERAND (arg1, 0),
+ 1))),
+ build_int_cst (TREE_TYPE (arg0), 0));
+
+ return NULL_TREE;
+
+ case UNORDERED_EXPR:
+ case ORDERED_EXPR:
+ case UNLT_EXPR:
+ case UNLE_EXPR:
+ case UNGT_EXPR:
+ case UNGE_EXPR:
+ case UNEQ_EXPR:
+ case LTGT_EXPR:
+ if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
+ {
+ t1 = fold_relational_const (code, type, arg0, arg1);
+ if (t1 != NULL_TREE)
+ return t1;
+ }
+
+ /* If the first operand is NaN, the result is constant. */
+ if (TREE_CODE (arg0) == REAL_CST
+ && REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
+ && (code != LTGT_EXPR || ! flag_trapping_math))
+ {
+ t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
+ ? integer_zero_node
+ : integer_one_node;
+ return omit_one_operand (type, t1, arg1);
+ }
+
+ /* If the second operand is NaN, the result is constant. */
+ if (TREE_CODE (arg1) == REAL_CST
+ && REAL_VALUE_ISNAN (TREE_REAL_CST (arg1))
+ && (code != LTGT_EXPR || ! flag_trapping_math))
+ {
+ t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
+ ? integer_zero_node
+ : integer_one_node;
+ return omit_one_operand (type, t1, arg0);
+ }
+
+ /* Simplify unordered comparison of something with itself. */
+ if ((code == UNLE_EXPR || code == UNGE_EXPR || code == UNEQ_EXPR)
+ && operand_equal_p (arg0, arg1, 0))
+ return constant_boolean_node (1, type);
+
+ if (code == LTGT_EXPR
+ && !flag_trapping_math
+ && operand_equal_p (arg0, arg1, 0))
+ return constant_boolean_node (0, type);
+
+ /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
+ {
+ tree targ0 = strip_float_extensions (arg0);
+ tree targ1 = strip_float_extensions (arg1);
+ tree newtype = TREE_TYPE (targ0);
+
+ if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
+ newtype = TREE_TYPE (targ1);
+
+ if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
+ return fold_build2 (code, type, fold_convert (newtype, targ0),
+ fold_convert (newtype, targ1));
+ }
+
+ return NULL_TREE;
+
+ case COMPOUND_EXPR:
+ /* When pedantic, a compound expression can be neither an lvalue
+ nor an integer constant expression. */
+ if (TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
+ return NULL_TREE;
+ /* Don't let (0, 0) be null pointer constant. */
+ tem = integer_zerop (arg1) ? build1 (NOP_EXPR, type, arg1)
+ : fold_convert (type, arg1);
+ return pedantic_non_lvalue (tem);
+
+ case COMPLEX_EXPR:
+ if ((TREE_CODE (arg0) == REAL_CST
+ && TREE_CODE (arg1) == REAL_CST)
+ || (TREE_CODE (arg0) == INTEGER_CST
+ && TREE_CODE (arg1) == INTEGER_CST))
+ return build_complex (type, arg0, arg1);
+ return NULL_TREE;
+
+ case ASSERT_EXPR:
+ /* An ASSERT_EXPR should never be passed to fold_binary. */
+ gcc_unreachable ();
+
+ default:
+ return NULL_TREE;
+ } /* switch (code) */
+}
+
+/* Callback for walk_tree, looking for LABEL_EXPR.
+ Returns tree TP if it is LABEL_EXPR. Otherwise it returns NULL_TREE.
+ Do not check the sub-tree of GOTO_EXPR. */
+
+static tree
+contains_label_1 (tree *tp,
+ int *walk_subtrees,
+ void *data ATTRIBUTE_UNUSED)
+{
+ switch (TREE_CODE (*tp))
+ {
+ case LABEL_EXPR:
+ return *tp;
+ case GOTO_EXPR:
+ *walk_subtrees = 0;
+ /* no break */
+ default:
+ return NULL_TREE;
+ }
+}
+
+/* Checks whether the sub-tree ST contains a label LABEL_EXPR which is
+ accessible from outside the sub-tree. Returns NULL_TREE if no
+ addressable label is found. */
+
+static bool
+contains_label_p (tree st)
+{
+ return (walk_tree (&st, contains_label_1 , NULL, NULL) != NULL_TREE);
+}
+
+/* Fold a ternary expression of code CODE and type TYPE with operands
+ OP0, OP1, and OP2. Return the folded expression if folding is
+ successful. Otherwise, return NULL_TREE. */
+
+tree
+fold_ternary (enum tree_code code, tree type, tree op0, tree op1, tree op2)
+{
+ tree tem;
+ tree arg0 = NULL_TREE, arg1 = NULL_TREE;
+ enum tree_code_class kind = TREE_CODE_CLASS (code);
+
+ gcc_assert (IS_EXPR_CODE_CLASS (kind)
+ && TREE_CODE_LENGTH (code) == 3);
+
+ /* Strip any conversions that don't change the mode. This is safe
+ for every expression, except for a comparison expression because
+ its signedness is derived from its operands. So, in the latter
+ case, only strip conversions that don't change the signedness.
+
+ Note that this is done as an internal manipulation within the
+ constant folder, in order to find the simplest representation of
+ the arguments so that their form can be studied. In any cases,
+ the appropriate type conversions should be put back in the tree
+ that will get out of the constant folder. */
+ if (op0)
+ {
+ arg0 = op0;
+ STRIP_NOPS (arg0);
+ }
+
+ if (op1)
+ {
+ arg1 = op1;
+ STRIP_NOPS (arg1);
+ }
+
+ switch (code)
+ {
+ case COMPONENT_REF:
+ if (TREE_CODE (arg0) == CONSTRUCTOR
+ && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
+ {
+ unsigned HOST_WIDE_INT idx;
+ tree field, value;
+ FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg0), idx, field, value)
+ if (field == arg1)
+ return value;
+ }
+ return NULL_TREE;
+
+ case COND_EXPR:
+ /* Pedantic ANSI C says that a conditional expression is never an lvalue,
+ so all simple results must be passed through pedantic_non_lvalue. */
+ if (TREE_CODE (arg0) == INTEGER_CST)
+ {
+ tree unused_op = integer_zerop (arg0) ? op1 : op2;
+ tem = integer_zerop (arg0) ? op2 : op1;
+ /* Only optimize constant conditions when the selected branch
+ has the same type as the COND_EXPR. This avoids optimizing
+ away "c ? x : throw", where the throw has a void type.
+ Avoid throwing away that operand which contains label. */
+ if ((!TREE_SIDE_EFFECTS (unused_op)
+ || !contains_label_p (unused_op))
+ && (! VOID_TYPE_P (TREE_TYPE (tem))
+ || VOID_TYPE_P (type)))
+ return pedantic_non_lvalue (tem);
+ return NULL_TREE;
+ }
+ if (operand_equal_p (arg1, op2, 0))
+ return pedantic_omit_one_operand (type, arg1, arg0);
+
+ /* If we have A op B ? A : C, we may be able to convert this to a
+ simpler expression, depending on the operation and the values
+ of B and C. Signed zeros prevent all of these transformations,
+ for reasons given above each one.
+
+ Also try swapping the arguments and inverting the conditional. */
+ if (COMPARISON_CLASS_P (arg0)
+ && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
+ arg1, TREE_OPERAND (arg0, 1))
+ && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
+ {
+ tem = fold_cond_expr_with_comparison (type, arg0, op1, op2);
+ if (tem)
+ return tem;
+ }
+
+ if (COMPARISON_CLASS_P (arg0)
+ && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
+ op2,
+ TREE_OPERAND (arg0, 1))
+ && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (op2))))
+ {
+ tem = fold_truth_not_expr (arg0);
+ if (tem && COMPARISON_CLASS_P (tem))
+ {
+ tem = fold_cond_expr_with_comparison (type, tem, op2, op1);
+ if (tem)
+ return tem;
+ }
+ }
+
+ /* If the second operand is simpler than the third, swap them
+ since that produces better jump optimization results. */
+ if (truth_value_p (TREE_CODE (arg0))
+ && tree_swap_operands_p (op1, op2, false))
+ {
+ /* See if this can be inverted. If it can't, possibly because
+ it was a floating-point inequality comparison, don't do
+ anything. */
+ tem = fold_truth_not_expr (arg0);
+ if (tem)
+ return fold_build3 (code, type, tem, op2, op1);
+ }
+
+ /* Convert A ? 1 : 0 to simply A. */
+ if (integer_onep (op1)
+ && integer_zerop (op2)
+ /* If we try to convert OP0 to our type, the
+ call to fold will try to move the conversion inside
+ a COND, which will recurse. In that case, the COND_EXPR
+ is probably the best choice, so leave it alone. */
+ && type == TREE_TYPE (arg0))
+ return pedantic_non_lvalue (arg0);
+
+ /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
+ over COND_EXPR in cases such as floating point comparisons. */
+ if (integer_zerop (op1)
+ && integer_onep (op2)
+ && truth_value_p (TREE_CODE (arg0)))
+ return pedantic_non_lvalue (fold_convert (type,
+ invert_truthvalue (arg0)));
+
+ /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
+ if (TREE_CODE (arg0) == LT_EXPR
+ && integer_zerop (TREE_OPERAND (arg0, 1))
+ && integer_zerop (op2)
+ && (tem = sign_bit_p (TREE_OPERAND (arg0, 0), arg1)))
+ {
+ /* sign_bit_p only checks ARG1 bits within A's precision.
+ If <sign bit of A> has wider type than A, bits outside
+ of A's precision in <sign bit of A> need to be checked.
+ If they are all 0, this optimization needs to be done
+ in unsigned A's type, if they are all 1 in signed A's type,
+ otherwise this can't be done. */
+ if (TYPE_PRECISION (TREE_TYPE (tem))
+ < TYPE_PRECISION (TREE_TYPE (arg1))
+ && TYPE_PRECISION (TREE_TYPE (tem))
+ < TYPE_PRECISION (type))
+ {
+ unsigned HOST_WIDE_INT mask_lo;
+ HOST_WIDE_INT mask_hi;
+ int inner_width, outer_width;
+ tree tem_type;
+
+ inner_width = TYPE_PRECISION (TREE_TYPE (tem));
+ outer_width = TYPE_PRECISION (TREE_TYPE (arg1));
+ if (outer_width > TYPE_PRECISION (type))
+ outer_width = TYPE_PRECISION (type);
+
+ if (outer_width > HOST_BITS_PER_WIDE_INT)
+ {
+ mask_hi = ((unsigned HOST_WIDE_INT) -1
+ >> (2 * HOST_BITS_PER_WIDE_INT - outer_width));
+ mask_lo = -1;
+ }
else
- parg = arg1, marg = arg0;
- parg0 = TREE_OPERAND (parg, 0);
- parg1 = TREE_OPERAND (parg, 1);
- STRIP_NOPS (parg0);
- STRIP_NOPS (parg1);
+ {
+ mask_hi = 0;
+ mask_lo = ((unsigned HOST_WIDE_INT) -1
+ >> (HOST_BITS_PER_WIDE_INT - outer_width));
+ }
+ if (inner_width > HOST_BITS_PER_WIDE_INT)
+ {
+ mask_hi &= ~((unsigned HOST_WIDE_INT) -1
+ >> (HOST_BITS_PER_WIDE_INT - inner_width));
+ mask_lo = 0;
+ }
+ else
+ mask_lo &= ~((unsigned HOST_WIDE_INT) -1
+ >> (HOST_BITS_PER_WIDE_INT - inner_width));
+
+ if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == mask_hi
+ && (TREE_INT_CST_LOW (arg1) & mask_lo) == mask_lo)
+ {
+ tem_type = signed_type_for (TREE_TYPE (tem));
+ tem = fold_convert (tem_type, tem);
+ }
+ else if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == 0
+ && (TREE_INT_CST_LOW (arg1) & mask_lo) == 0)
+ {
+ tem_type = unsigned_type_for (TREE_TYPE (tem));
+ tem = fold_convert (tem_type, tem);
+ }
+ else
+ tem = NULL;
+ }
+
+ if (tem)
+ return fold_convert (type,
+ fold_build2 (BIT_AND_EXPR,
+ TREE_TYPE (tem), tem,
+ fold_convert (TREE_TYPE (tem),
+ arg1)));
+ }
+
+ /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
+ already handled above. */
+ if (TREE_CODE (arg0) == BIT_AND_EXPR
+ && integer_onep (TREE_OPERAND (arg0, 1))
+ && integer_zerop (op2)
+ && integer_pow2p (arg1))
+ {
+ tree tem = TREE_OPERAND (arg0, 0);
+ STRIP_NOPS (tem);
+ if (TREE_CODE (tem) == RSHIFT_EXPR
+ && TREE_CODE (TREE_OPERAND (tem, 1)) == INTEGER_CST
+ && (unsigned HOST_WIDE_INT) tree_log2 (arg1) ==
+ TREE_INT_CST_LOW (TREE_OPERAND (tem, 1)))
+ return fold_build2 (BIT_AND_EXPR, type,
+ TREE_OPERAND (tem, 0), arg1);
+ }
+
+ /* A & N ? N : 0 is simply A & N if N is a power of two. This
+ is probably obsolete because the first operand should be a
+ truth value (that's why we have the two cases above), but let's
+ leave it in until we can confirm this for all front-ends. */
+ if (integer_zerop (op2)
+ && TREE_CODE (arg0) == NE_EXPR
+ && integer_zerop (TREE_OPERAND (arg0, 1))
+ && integer_pow2p (arg1)
+ && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
+ && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
+ arg1, OEP_ONLY_CONST))
+ return pedantic_non_lvalue (fold_convert (type,
+ TREE_OPERAND (arg0, 0)));
+
+ /* Convert A ? B : 0 into A && B if A and B are truth values. */
+ if (integer_zerop (op2)
+ && truth_value_p (TREE_CODE (arg0))
+ && truth_value_p (TREE_CODE (arg1)))
+ return fold_build2 (TRUTH_ANDIF_EXPR, type,
+ fold_convert (type, arg0),
+ arg1);
+
+ /* Convert A ? B : 1 into !A || B if A and B are truth values. */
+ if (integer_onep (op2)
+ && truth_value_p (TREE_CODE (arg0))
+ && truth_value_p (TREE_CODE (arg1)))
+ {
+ /* Only perform transformation if ARG0 is easily inverted. */
+ tem = fold_truth_not_expr (arg0);
+ if (tem)
+ return fold_build2 (TRUTH_ORIF_EXPR, type,
+ fold_convert (type, tem),
+ arg1);
+ }
+
+ /* Convert A ? 0 : B into !A && B if A and B are truth values. */
+ if (integer_zerop (arg1)
+ && truth_value_p (TREE_CODE (arg0))
+ && truth_value_p (TREE_CODE (op2)))
+ {
+ /* Only perform transformation if ARG0 is easily inverted. */
+ tem = fold_truth_not_expr (arg0);
+ if (tem)
+ return fold_build2 (TRUTH_ANDIF_EXPR, type,
+ fold_convert (type, tem),
+ op2);
+ }
+
+ /* Convert A ? 1 : B into A || B if A and B are truth values. */
+ if (integer_onep (arg1)
+ && truth_value_p (TREE_CODE (arg0))
+ && truth_value_p (TREE_CODE (op2)))
+ return fold_build2 (TRUTH_ORIF_EXPR, type,
+ fold_convert (type, arg0),
+ op2);
- if (TREE_CODE (parg0) == MULT_EXPR
- && TREE_CODE (parg1) != MULT_EXPR)
- return fold (build (PLUS_EXPR, type,
- fold (build (PLUS_EXPR, type, parg0, marg)),
- parg1));
- if (TREE_CODE (parg0) != MULT_EXPR
- && TREE_CODE (parg1) == MULT_EXPR)
- return fold (build (PLUS_EXPR, type,
- fold (build (PLUS_EXPR, type, parg1, marg)),
- parg0));
- }
+ return NULL_TREE;
- if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
+ case CALL_EXPR:
+ /* CALL_EXPRs used to be ternary exprs. Catch any mistaken uses
+ of fold_ternary on them. */
+ gcc_unreachable ();
+
+ case BIT_FIELD_REF:
+ if ((TREE_CODE (arg0) == VECTOR_CST
+ || (TREE_CODE (arg0) == CONSTRUCTOR && TREE_CONSTANT (arg0)))
+ && type == TREE_TYPE (TREE_TYPE (arg0)))
+ {
+ unsigned HOST_WIDE_INT width = tree_low_cst (arg1, 1);
+ unsigned HOST_WIDE_INT idx = tree_low_cst (op2, 1);
+
+ if (width != 0
+ && simple_cst_equal (arg1, TYPE_SIZE (type)) == 1
+ && (idx % width) == 0
+ && (idx = idx / width)
+ < TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0)))
{
- tree arg00, arg01, arg10, arg11;
- tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
-
- /* (A * C) + (B * C) -> (A+B) * C.
- We are most concerned about the case where C is a constant,
- but other combinations show up during loop reduction. Since
- it is not difficult, try all four possibilities. */
-
- arg00 = TREE_OPERAND (arg0, 0);
- arg01 = TREE_OPERAND (arg0, 1);
- arg10 = TREE_OPERAND (arg1, 0);
- arg11 = TREE_OPERAND (arg1, 1);
- same = NULL_TREE;
-
- if (operand_equal_p (arg01, arg11, 0))
- same = arg01, alt0 = arg00, alt1 = arg10;
- else if (operand_equal_p (arg00, arg10, 0))
- same = arg00, alt0 = arg01, alt1 = arg11;
- else if (operand_equal_p (arg00, arg11, 0))
- same = arg00, alt0 = arg01, alt1 = arg10;
- else if (operand_equal_p (arg01, arg10, 0))
- same = arg01, alt0 = arg00, alt1 = arg11;
-
- /* No identical multiplicands; see if we can find a common
- power-of-two factor in non-power-of-two multiplies. This
- can help in multi-dimensional array access. */
- else if (TREE_CODE (arg01) == INTEGER_CST
- && TREE_CODE (arg11) == INTEGER_CST
- && TREE_INT_CST_HIGH (arg01) == 0
- && TREE_INT_CST_HIGH (arg11) == 0)
- {
- HOST_WIDE_INT int01, int11, tmp;
- int01 = TREE_INT_CST_LOW (arg01);
- int11 = TREE_INT_CST_LOW (arg11);
+ tree elements = NULL_TREE;
- /* Move min of absolute values to int11. */
- if ((int01 >= 0 ? int01 : -int01)
- < (int11 >= 0 ? int11 : -int11))
- {
- tmp = int01, int01 = int11, int11 = tmp;
- alt0 = arg00, arg00 = arg10, arg10 = alt0;
- alt0 = arg01, arg01 = arg11, arg11 = alt0;
- }
+ if (TREE_CODE (arg0) == VECTOR_CST)
+ elements = TREE_VECTOR_CST_ELTS (arg0);
+ else
+ {
+ unsigned HOST_WIDE_INT idx;
+ tree value;
- if (exact_log2 (int11) > 0 && int01 % int11 == 0)
- {
- alt0 = fold (build (MULT_EXPR, type, arg00,
- build_int_2 (int01 / int11, 0)));
- alt1 = arg10;
- same = arg11;
- }
+ FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg0), idx, value)
+ elements = tree_cons (NULL_TREE, value, elements);
}
-
- if (same)
- return fold (build (MULT_EXPR, type,
- fold (build (PLUS_EXPR, type, alt0, alt1)),
- same));
+ while (idx-- > 0 && elements)
+ elements = TREE_CHAIN (elements);
+ if (elements)
+ return TREE_VALUE (elements);
+ else
+ return fold_convert (type, integer_zero_node);
}
}
- /* In IEEE floating point, x+0 may not equal x. */
- else if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
- || flag_unsafe_math_optimizations)
- && real_zerop (arg1))
- return non_lvalue (convert (type, arg0));
- /* x+(-0) equals x, even for IEEE. */
- else if (TREE_CODE (arg1) == REAL_CST
- && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (arg1)))
- return non_lvalue (convert (type, arg0));
- bit_rotate:
- /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
- is a rotate of A by C1 bits. */
- /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
- is a rotate of A by B bits. */
+ /* A bit-field-ref that referenced the full argument can be stripped. */
+ if (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
+ && TYPE_PRECISION (TREE_TYPE (arg0)) == tree_low_cst (arg1, 1)
+ && integer_zerop (op2))
+ return fold_convert (type, arg0);
+
+ return NULL_TREE;
+
+ default:
+ return NULL_TREE;
+ } /* switch (code) */
+}
+
+/* Perform constant folding and related simplification of EXPR.
+ The related simplifications include x*1 => x, x*0 => 0, etc.,
+ and application of the associative law.
+ NOP_EXPR conversions may be removed freely (as long as we
+ are careful not to change the type of the overall expression).
+ We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
+ but we can constant-fold them if they have constant operands. */
+
+#ifdef ENABLE_FOLD_CHECKING
+# define fold(x) fold_1 (x)
+static tree fold_1 (tree);
+static
+#endif
+tree
+fold (tree expr)
+{
+ const tree t = expr;
+ enum tree_code code = TREE_CODE (t);
+ enum tree_code_class kind = TREE_CODE_CLASS (code);
+ tree tem;
+
+ /* Return right away if a constant. */
+ if (kind == tcc_constant)
+ return t;
+
+ /* CALL_EXPR-like objects with variable numbers of operands are
+ treated specially. */
+ if (kind == tcc_vl_exp)
+ {
+ if (code == CALL_EXPR)
+ {
+ tem = fold_call_expr (expr, false);
+ return tem ? tem : expr;
+ }
+ return expr;
+ }
+
+ if (IS_EXPR_CODE_CLASS (kind))
+ {
+ tree type = TREE_TYPE (t);
+ tree op0, op1, op2;
+
+ switch (TREE_CODE_LENGTH (code))
+ {
+ case 1:
+ op0 = TREE_OPERAND (t, 0);
+ tem = fold_unary (code, type, op0);
+ return tem ? tem : expr;
+ case 2:
+ op0 = TREE_OPERAND (t, 0);
+ op1 = TREE_OPERAND (t, 1);
+ tem = fold_binary (code, type, op0, op1);
+ return tem ? tem : expr;
+ case 3:
+ op0 = TREE_OPERAND (t, 0);
+ op1 = TREE_OPERAND (t, 1);
+ op2 = TREE_OPERAND (t, 2);
+ tem = fold_ternary (code, type, op0, op1, op2);
+ return tem ? tem : expr;
+ default:
+ break;
+ }
+ }
+
+ switch (code)
+ {
+ case ARRAY_REF:
{
- enum tree_code code0, code1;
- code0 = TREE_CODE (arg0);
- code1 = TREE_CODE (arg1);
- if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
- || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
- && operand_equal_p (TREE_OPERAND (arg0, 0),
- TREE_OPERAND (arg1, 0), 0)
- && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
+ tree op0 = TREE_OPERAND (t, 0);
+ tree op1 = TREE_OPERAND (t, 1);
+
+ if (TREE_CODE (op1) == INTEGER_CST
+ && TREE_CODE (op0) == CONSTRUCTOR
+ && ! type_contains_placeholder_p (TREE_TYPE (op0)))
{
- tree tree01, tree11;
- enum tree_code code01, code11;
+ VEC(constructor_elt,gc) *elts = CONSTRUCTOR_ELTS (op0);
+ unsigned HOST_WIDE_INT end = VEC_length (constructor_elt, elts);
+ unsigned HOST_WIDE_INT begin = 0;
- tree01 = TREE_OPERAND (arg0, 1);
- tree11 = TREE_OPERAND (arg1, 1);
- STRIP_NOPS (tree01);
- STRIP_NOPS (tree11);
- code01 = TREE_CODE (tree01);
- code11 = TREE_CODE (tree11);
- if (code01 == INTEGER_CST
- && code11 == INTEGER_CST
- && TREE_INT_CST_HIGH (tree01) == 0
- && TREE_INT_CST_HIGH (tree11) == 0
- && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
- == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
- return build (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
- code0 == LSHIFT_EXPR ? tree01 : tree11);
- else if (code11 == MINUS_EXPR)
- {
- tree tree110, tree111;
- tree110 = TREE_OPERAND (tree11, 0);
- tree111 = TREE_OPERAND (tree11, 1);
- STRIP_NOPS (tree110);
- STRIP_NOPS (tree111);
- if (TREE_CODE (tree110) == INTEGER_CST
- && 0 == compare_tree_int (tree110,
- TYPE_PRECISION
- (TREE_TYPE (TREE_OPERAND
- (arg0, 0))))
- && operand_equal_p (tree01, tree111, 0))
- return build ((code0 == LSHIFT_EXPR
- ? LROTATE_EXPR
- : RROTATE_EXPR),
- type, TREE_OPERAND (arg0, 0), tree01);
- }
- else if (code01 == MINUS_EXPR)
+ /* Find a matching index by means of a binary search. */
+ while (begin != end)
{
- tree tree010, tree011;
- tree010 = TREE_OPERAND (tree01, 0);
- tree011 = TREE_OPERAND (tree01, 1);
- STRIP_NOPS (tree010);
- STRIP_NOPS (tree011);
- if (TREE_CODE (tree010) == INTEGER_CST
- && 0 == compare_tree_int (tree010,
- TYPE_PRECISION
- (TREE_TYPE (TREE_OPERAND
- (arg0, 0))))
- && operand_equal_p (tree11, tree011, 0))
- return build ((code0 != LSHIFT_EXPR
- ? LROTATE_EXPR
- : RROTATE_EXPR),
- type, TREE_OPERAND (arg0, 0), tree11);
+ unsigned HOST_WIDE_INT middle = (begin + end) / 2;
+ tree index = VEC_index (constructor_elt, elts, middle)->index;
+
+ if (TREE_CODE (index) == INTEGER_CST
+ && tree_int_cst_lt (index, op1))
+ begin = middle + 1;
+ else if (TREE_CODE (index) == INTEGER_CST
+ && tree_int_cst_lt (op1, index))
+ end = middle;
+ else if (TREE_CODE (index) == RANGE_EXPR
+ && tree_int_cst_lt (TREE_OPERAND (index, 1), op1))
+ begin = middle + 1;
+ else if (TREE_CODE (index) == RANGE_EXPR
+ && tree_int_cst_lt (op1, TREE_OPERAND (index, 0)))
+ end = middle;
+ else
+ return VEC_index (constructor_elt, elts, middle)->value;
}
}
+
+ return t;
}
- associate:
- /* In most languages, can't associate operations on floats through
- parentheses. Rather than remember where the parentheses were, we
- don't associate floats at all. It shouldn't matter much. However,
- associating multiplications is only very slightly inaccurate, so do
- that if -funsafe-math-optimizations is specified. */
+ case CONST_DECL:
+ return fold (DECL_INITIAL (t));
+
+ default:
+ return t;
+ } /* switch (code) */
+}
+
+#ifdef ENABLE_FOLD_CHECKING
+#undef fold
+
+static void fold_checksum_tree (const_tree, struct md5_ctx *, htab_t);
+static void fold_check_failed (const_tree, const_tree);
+void print_fold_checksum (const_tree);
+
+/* When --enable-checking=fold, compute a digest of expr before
+ and after actual fold call to see if fold did not accidentally
+ change original expr. */
+
+tree
+fold (tree expr)
+{
+ tree ret;
+ struct md5_ctx ctx;
+ unsigned char checksum_before[16], checksum_after[16];
+ htab_t ht;
+
+ ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
+ md5_init_ctx (&ctx);
+ fold_checksum_tree (expr, &ctx, ht);
+ md5_finish_ctx (&ctx, checksum_before);
+ htab_empty (ht);
+
+ ret = fold_1 (expr);
+
+ md5_init_ctx (&ctx);
+ fold_checksum_tree (expr, &ctx, ht);
+ md5_finish_ctx (&ctx, checksum_after);
+ htab_delete (ht);
+
+ if (memcmp (checksum_before, checksum_after, 16))
+ fold_check_failed (expr, ret);
+
+ return ret;
+}
+
+void
+print_fold_checksum (const_tree expr)
+{
+ struct md5_ctx ctx;
+ unsigned char checksum[16], cnt;
+ htab_t ht;
+
+ ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
+ md5_init_ctx (&ctx);
+ fold_checksum_tree (expr, &ctx, ht);
+ md5_finish_ctx (&ctx, checksum);
+ htab_delete (ht);
+ for (cnt = 0; cnt < 16; ++cnt)
+ fprintf (stderr, "%02x", checksum[cnt]);
+ putc ('\n', stderr);
+}
+
+static void
+fold_check_failed (const_tree expr ATTRIBUTE_UNUSED, const_tree ret ATTRIBUTE_UNUSED)
+{
+ internal_error ("fold check: original tree changed by fold");
+}
+
+static void
+fold_checksum_tree (const_tree expr, struct md5_ctx *ctx, htab_t ht)
+{
+ const void **slot;
+ enum tree_code code;
+ union tree_node buf;
+ int i, len;
+
+recursive_label:
+
+ gcc_assert ((sizeof (struct tree_exp) + 5 * sizeof (tree)
+ <= sizeof (struct tree_function_decl))
+ && sizeof (struct tree_type) <= sizeof (struct tree_function_decl));
+ if (expr == NULL)
+ return;
+ slot = (const void **) htab_find_slot (ht, expr, INSERT);
+ if (*slot != NULL)
+ return;
+ *slot = expr;
+ code = TREE_CODE (expr);
+ if (TREE_CODE_CLASS (code) == tcc_declaration
+ && DECL_ASSEMBLER_NAME_SET_P (expr))
+ {
+ /* Allow DECL_ASSEMBLER_NAME to be modified. */
+ memcpy ((char *) &buf, expr, tree_size (expr));
+ SET_DECL_ASSEMBLER_NAME ((tree)&buf, NULL);
+ expr = (tree) &buf;
+ }
+ else if (TREE_CODE_CLASS (code) == tcc_type
+ && (TYPE_POINTER_TO (expr)
+ || TYPE_REFERENCE_TO (expr)
+ || TYPE_CACHED_VALUES_P (expr)
+ || TYPE_CONTAINS_PLACEHOLDER_INTERNAL (expr)
+ || TYPE_NEXT_VARIANT (expr)))
+ {
+ /* Allow these fields to be modified. */
+ tree tmp;
+ memcpy ((char *) &buf, expr, tree_size (expr));
+ expr = tmp = (tree) &buf;
+ TYPE_CONTAINS_PLACEHOLDER_INTERNAL (tmp) = 0;
+ TYPE_POINTER_TO (tmp) = NULL;
+ TYPE_REFERENCE_TO (tmp) = NULL;
+ TYPE_NEXT_VARIANT (tmp) = NULL;
+ if (TYPE_CACHED_VALUES_P (tmp))
+ {
+ TYPE_CACHED_VALUES_P (tmp) = 0;
+ TYPE_CACHED_VALUES (tmp) = NULL;
+ }
+ }
+ md5_process_bytes (expr, tree_size (expr), ctx);
+ fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
+ if (TREE_CODE_CLASS (code) != tcc_type
+ && TREE_CODE_CLASS (code) != tcc_declaration
+ && code != TREE_LIST
+ && code != SSA_NAME)
+ fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
+ switch (TREE_CODE_CLASS (code))
+ {
+ case tcc_constant:
+ switch (code)
+ {
+ case STRING_CST:
+ md5_process_bytes (TREE_STRING_POINTER (expr),
+ TREE_STRING_LENGTH (expr), ctx);
+ break;
+ case COMPLEX_CST:
+ fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
+ fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
+ break;
+ case VECTOR_CST:
+ fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
+ break;
+ default:
+ break;
+ }
+ break;
+ case tcc_exceptional:
+ switch (code)
+ {
+ case TREE_LIST:
+ fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
+ fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
+ expr = TREE_CHAIN (expr);
+ goto recursive_label;
+ break;
+ case TREE_VEC:
+ for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
+ fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
+ break;
+ default:
+ break;
+ }
+ break;
+ case tcc_expression:
+ case tcc_reference:
+ case tcc_comparison:
+ case tcc_unary:
+ case tcc_binary:
+ case tcc_statement:
+ case tcc_vl_exp:
+ len = TREE_OPERAND_LENGTH (expr);
+ for (i = 0; i < len; ++i)
+ fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
+ break;
+ case tcc_declaration:
+ fold_checksum_tree (DECL_NAME (expr), ctx, ht);
+ fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
+ if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_COMMON))
+ {
+ fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
+ fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
+ fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
+ fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
+ fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
+ }
+ if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_WITH_VIS))
+ fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
+
+ if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_NON_COMMON))
+ {
+ fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
+ fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
+ fold_checksum_tree (DECL_ARGUMENT_FLD (expr), ctx, ht);
+ }
+ break;
+ case tcc_type:
+ if (TREE_CODE (expr) == ENUMERAL_TYPE)
+ fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
+ fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
+ fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
+ fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
+ fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
+ if (INTEGRAL_TYPE_P (expr)
+ || SCALAR_FLOAT_TYPE_P (expr))
+ {
+ fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
+ fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
+ }
+ fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
+ if (TREE_CODE (expr) == RECORD_TYPE
+ || TREE_CODE (expr) == UNION_TYPE
+ || TREE_CODE (expr) == QUAL_UNION_TYPE)
+ fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
+ fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
+ break;
+ default:
+ break;
+ }
+}
+
+/* Helper function for outputting the checksum of a tree T. When
+ debugging with gdb, you can "define mynext" to be "next" followed
+ by "call debug_fold_checksum (op0)", then just trace down till the
+ outputs differ. */
+
+void
+debug_fold_checksum (const_tree t)
+{
+ int i;
+ unsigned char checksum[16];
+ struct md5_ctx ctx;
+ htab_t ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
+
+ md5_init_ctx (&ctx);
+ fold_checksum_tree (t, &ctx, ht);
+ md5_finish_ctx (&ctx, checksum);
+ htab_empty (ht);
+
+ for (i = 0; i < 16; i++)
+ fprintf (stderr, "%d ", checksum[i]);
+
+ fprintf (stderr, "\n");
+}
+
+#endif
+
+/* Fold a unary tree expression with code CODE of type TYPE with an
+ operand OP0. Return a folded expression if successful. Otherwise,
+ return a tree expression with code CODE of type TYPE with an
+ operand OP0. */
+
+tree
+fold_build1_stat (enum tree_code code, tree type, tree op0 MEM_STAT_DECL)
+{
+ tree tem;
+#ifdef ENABLE_FOLD_CHECKING
+ unsigned char checksum_before[16], checksum_after[16];
+ struct md5_ctx ctx;
+ htab_t ht;
+
+ ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
+ md5_init_ctx (&ctx);
+ fold_checksum_tree (op0, &ctx, ht);
+ md5_finish_ctx (&ctx, checksum_before);
+ htab_empty (ht);
+#endif
+
+ tem = fold_unary (code, type, op0);
+ if (!tem)
+ tem = build1_stat (code, type, op0 PASS_MEM_STAT);
+
+#ifdef ENABLE_FOLD_CHECKING
+ md5_init_ctx (&ctx);
+ fold_checksum_tree (op0, &ctx, ht);
+ md5_finish_ctx (&ctx, checksum_after);
+ htab_delete (ht);
+
+ if (memcmp (checksum_before, checksum_after, 16))
+ fold_check_failed (op0, tem);
+#endif
+ return tem;
+}
+
+/* Fold a binary tree expression with code CODE of type TYPE with
+ operands OP0 and OP1. Return a folded expression if successful.
+ Otherwise, return a tree expression with code CODE of type TYPE
+ with operands OP0 and OP1. */
+
+tree
+fold_build2_stat (enum tree_code code, tree type, tree op0, tree op1
+ MEM_STAT_DECL)
+{
+ tree tem;
+#ifdef ENABLE_FOLD_CHECKING
+ unsigned char checksum_before_op0[16],
+ checksum_before_op1[16],
+ checksum_after_op0[16],
+ checksum_after_op1[16];
+ struct md5_ctx ctx;
+ htab_t ht;
+
+ ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
+ md5_init_ctx (&ctx);
+ fold_checksum_tree (op0, &ctx, ht);
+ md5_finish_ctx (&ctx, checksum_before_op0);
+ htab_empty (ht);
+
+ md5_init_ctx (&ctx);
+ fold_checksum_tree (op1, &ctx, ht);
+ md5_finish_ctx (&ctx, checksum_before_op1);
+ htab_empty (ht);
+#endif
+
+ tem = fold_binary (code, type, op0, op1);
+ if (!tem)
+ tem = build2_stat (code, type, op0, op1 PASS_MEM_STAT);
+
+#ifdef ENABLE_FOLD_CHECKING
+ md5_init_ctx (&ctx);
+ fold_checksum_tree (op0, &ctx, ht);
+ md5_finish_ctx (&ctx, checksum_after_op0);
+ htab_empty (ht);
+
+ if (memcmp (checksum_before_op0, checksum_after_op0, 16))
+ fold_check_failed (op0, tem);
+
+ md5_init_ctx (&ctx);
+ fold_checksum_tree (op1, &ctx, ht);
+ md5_finish_ctx (&ctx, checksum_after_op1);
+ htab_delete (ht);
+
+ if (memcmp (checksum_before_op1, checksum_after_op1, 16))
+ fold_check_failed (op1, tem);
+#endif
+ return tem;
+}
+
+/* Fold a ternary tree expression with code CODE of type TYPE with
+ operands OP0, OP1, and OP2. Return a folded expression if
+ successful. Otherwise, return a tree expression with code CODE of
+ type TYPE with operands OP0, OP1, and OP2. */
+
+tree
+fold_build3_stat (enum tree_code code, tree type, tree op0, tree op1, tree op2
+ MEM_STAT_DECL)
+{
+ tree tem;
+#ifdef ENABLE_FOLD_CHECKING
+ unsigned char checksum_before_op0[16],
+ checksum_before_op1[16],
+ checksum_before_op2[16],
+ checksum_after_op0[16],
+ checksum_after_op1[16],
+ checksum_after_op2[16];
+ struct md5_ctx ctx;
+ htab_t ht;
+
+ ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
+ md5_init_ctx (&ctx);
+ fold_checksum_tree (op0, &ctx, ht);
+ md5_finish_ctx (&ctx, checksum_before_op0);
+ htab_empty (ht);
+
+ md5_init_ctx (&ctx);
+ fold_checksum_tree (op1, &ctx, ht);
+ md5_finish_ctx (&ctx, checksum_before_op1);
+ htab_empty (ht);
+
+ md5_init_ctx (&ctx);
+ fold_checksum_tree (op2, &ctx, ht);
+ md5_finish_ctx (&ctx, checksum_before_op2);
+ htab_empty (ht);
+#endif
+
+ gcc_assert (TREE_CODE_CLASS (code) != tcc_vl_exp);
+ tem = fold_ternary (code, type, op0, op1, op2);
+ if (!tem)
+ tem = build3_stat (code, type, op0, op1, op2 PASS_MEM_STAT);
+
+#ifdef ENABLE_FOLD_CHECKING
+ md5_init_ctx (&ctx);
+ fold_checksum_tree (op0, &ctx, ht);
+ md5_finish_ctx (&ctx, checksum_after_op0);
+ htab_empty (ht);
+
+ if (memcmp (checksum_before_op0, checksum_after_op0, 16))
+ fold_check_failed (op0, tem);
+
+ md5_init_ctx (&ctx);
+ fold_checksum_tree (op1, &ctx, ht);
+ md5_finish_ctx (&ctx, checksum_after_op1);
+ htab_empty (ht);
+
+ if (memcmp (checksum_before_op1, checksum_after_op1, 16))
+ fold_check_failed (op1, tem);
+
+ md5_init_ctx (&ctx);
+ fold_checksum_tree (op2, &ctx, ht);
+ md5_finish_ctx (&ctx, checksum_after_op2);
+ htab_delete (ht);
+
+ if (memcmp (checksum_before_op2, checksum_after_op2, 16))
+ fold_check_failed (op2, tem);
+#endif
+ return tem;
+}
+
+/* Fold a CALL_EXPR expression of type TYPE with operands FN and NARGS
+ arguments in ARGARRAY, and a null static chain.
+ Return a folded expression if successful. Otherwise, return a CALL_EXPR
+ of type TYPE from the given operands as constructed by build_call_array. */
+
+tree
+fold_build_call_array (tree type, tree fn, int nargs, tree *argarray)
+{
+ tree tem;
+#ifdef ENABLE_FOLD_CHECKING
+ unsigned char checksum_before_fn[16],
+ checksum_before_arglist[16],
+ checksum_after_fn[16],
+ checksum_after_arglist[16];
+ struct md5_ctx ctx;
+ htab_t ht;
+ int i;
+
+ ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
+ md5_init_ctx (&ctx);
+ fold_checksum_tree (fn, &ctx, ht);
+ md5_finish_ctx (&ctx, checksum_before_fn);
+ htab_empty (ht);
+
+ md5_init_ctx (&ctx);
+ for (i = 0; i < nargs; i++)
+ fold_checksum_tree (argarray[i], &ctx, ht);
+ md5_finish_ctx (&ctx, checksum_before_arglist);
+ htab_empty (ht);
+#endif
+
+ tem = fold_builtin_call_array (type, fn, nargs, argarray);
+
+#ifdef ENABLE_FOLD_CHECKING
+ md5_init_ctx (&ctx);
+ fold_checksum_tree (fn, &ctx, ht);
+ md5_finish_ctx (&ctx, checksum_after_fn);
+ htab_empty (ht);
+
+ if (memcmp (checksum_before_fn, checksum_after_fn, 16))
+ fold_check_failed (fn, tem);
+
+ md5_init_ctx (&ctx);
+ for (i = 0; i < nargs; i++)
+ fold_checksum_tree (argarray[i], &ctx, ht);
+ md5_finish_ctx (&ctx, checksum_after_arglist);
+ htab_delete (ht);
+
+ if (memcmp (checksum_before_arglist, checksum_after_arglist, 16))
+ fold_check_failed (NULL_TREE, tem);
+#endif
+ return tem;
+}
+
+/* Perform constant folding and related simplification of initializer
+ expression EXPR. These behave identically to "fold_buildN" but ignore
+ potential run-time traps and exceptions that fold must preserve. */
+
+#define START_FOLD_INIT \
+ int saved_signaling_nans = flag_signaling_nans;\
+ int saved_trapping_math = flag_trapping_math;\
+ int saved_rounding_math = flag_rounding_math;\
+ int saved_trapv = flag_trapv;\
+ int saved_folding_initializer = folding_initializer;\
+ flag_signaling_nans = 0;\
+ flag_trapping_math = 0;\
+ flag_rounding_math = 0;\
+ flag_trapv = 0;\
+ folding_initializer = 1;
+
+#define END_FOLD_INIT \
+ flag_signaling_nans = saved_signaling_nans;\
+ flag_trapping_math = saved_trapping_math;\
+ flag_rounding_math = saved_rounding_math;\
+ flag_trapv = saved_trapv;\
+ folding_initializer = saved_folding_initializer;
+
+tree
+fold_build1_initializer (enum tree_code code, tree type, tree op)
+{
+ tree result;
+ START_FOLD_INIT;
+
+ result = fold_build1 (code, type, op);
+
+ END_FOLD_INIT;
+ return result;
+}
+
+tree
+fold_build2_initializer (enum tree_code code, tree type, tree op0, tree op1)
+{
+ tree result;
+ START_FOLD_INIT;
+
+ result = fold_build2 (code, type, op0, op1);
+
+ END_FOLD_INIT;
+ return result;
+}
+
+tree
+fold_build3_initializer (enum tree_code code, tree type, tree op0, tree op1,
+ tree op2)
+{
+ tree result;
+ START_FOLD_INIT;
- if (! wins
- && (! FLOAT_TYPE_P (type)
- || (flag_unsafe_math_optimizations && code == MULT_EXPR)))
- {
- tree var0, con0, lit0, minus_lit0;
- tree var1, con1, lit1, minus_lit1;
+ result = fold_build3 (code, type, op0, op1, op2);
- /* Split both trees into variables, constants, and literals. Then
- associate each group together, the constants with literals,
- then the result with variables. This increases the chances of
- literals being recombined later and of generating relocatable
- expressions for the sum of a constant and literal. */
- var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
- var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
- code == MINUS_EXPR);
+ END_FOLD_INIT;
+ return result;
+}
- /* Only do something if we found more than two objects. Otherwise,
- nothing has changed and we risk infinite recursion. */
- if (2 < ((var0 != 0) + (var1 != 0)
- + (con0 != 0) + (con1 != 0)
- + (lit0 != 0) + (lit1 != 0)
- + (minus_lit0 != 0) + (minus_lit1 != 0)))
- {
- /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
- if (code == MINUS_EXPR)
- code = PLUS_EXPR;
+tree
+fold_build_call_array_initializer (tree type, tree fn,
+ int nargs, tree *argarray)
+{
+ tree result;
+ START_FOLD_INIT;
- var0 = associate_trees (var0, var1, code, type);
- con0 = associate_trees (con0, con1, code, type);
- lit0 = associate_trees (lit0, lit1, code, type);
- minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
+ result = fold_build_call_array (type, fn, nargs, argarray);
- /* Preserve the MINUS_EXPR if the negative part of the literal is
- greater than the positive part. Otherwise, the multiplicative
- folding code (i.e extract_muldiv) may be fooled in case
- unsigned constants are substracted, like in the following
- example: ((X*2 + 4) - 8U)/2. */
- if (minus_lit0 && lit0)
- {
- if (tree_int_cst_lt (lit0, minus_lit0))
- {
- minus_lit0 = associate_trees (minus_lit0, lit0,
- MINUS_EXPR, type);
- lit0 = 0;
- }
- else
- {
- lit0 = associate_trees (lit0, minus_lit0,
- MINUS_EXPR, type);
- minus_lit0 = 0;
- }
- }
- if (minus_lit0)
- {
- if (con0 == 0)
- return convert (type, associate_trees (var0, minus_lit0,
- MINUS_EXPR, type));
- else
- {
- con0 = associate_trees (con0, minus_lit0,
- MINUS_EXPR, type);
- return convert (type, associate_trees (var0, con0,
- PLUS_EXPR, type));
- }
- }
+ END_FOLD_INIT;
+ return result;
+}
- con0 = associate_trees (con0, lit0, code, type);
- return convert (type, associate_trees (var0, con0, code, type));
- }
- }
+#undef START_FOLD_INIT
+#undef END_FOLD_INIT
- binary:
-#if defined (REAL_IS_NOT_DOUBLE) && ! defined (REAL_ARITHMETIC)
- if (TREE_CODE (arg1) == REAL_CST)
- return t;
-#endif /* REAL_IS_NOT_DOUBLE, and no REAL_ARITHMETIC */
- if (wins)
- t1 = const_binop (code, arg0, arg1, 0);
- if (t1 != NULL_TREE)
- {
- /* The return value should always have
- the same type as the original expression. */
- if (TREE_TYPE (t1) != TREE_TYPE (t))
- t1 = convert (TREE_TYPE (t), t1);
+/* Determine if first argument is a multiple of second argument. Return 0 if
+ it is not, or we cannot easily determined it to be.
- return t1;
- }
- return t;
+ An example of the sort of thing we care about (at this point; this routine
+ could surely be made more general, and expanded to do what the *_DIV_EXPR's
+ fold cases do now) is discovering that
- case MINUS_EXPR:
- /* A - (-B) -> A + B */
- if (TREE_CODE (arg1) == NEGATE_EXPR)
- return fold (build (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
- /* (-A) - CST -> (-CST) - A for floating point (what about ints ?) */
- if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == REAL_CST)
- return
- fold (build (MINUS_EXPR, type,
- build_real (TREE_TYPE (arg1),
- REAL_VALUE_NEGATE (TREE_REAL_CST (arg1))),
- TREE_OPERAND (arg0, 0)));
+ SAVE_EXPR (I) * SAVE_EXPR (J * 8)
- if (! FLOAT_TYPE_P (type))
- {
- if (! wins && integer_zerop (arg0))
- return negate_expr (convert (type, arg1));
- if (integer_zerop (arg1))
- return non_lvalue (convert (type, arg0));
+ is a multiple of
- /* (A * C) - (B * C) -> (A-B) * C. Since we are most concerned
- about the case where C is a constant, just try one of the
- four possibilities. */
+ SAVE_EXPR (J * 8)
- if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR
- && operand_equal_p (TREE_OPERAND (arg0, 1),
- TREE_OPERAND (arg1, 1), 0))
- return fold (build (MULT_EXPR, type,
- fold (build (MINUS_EXPR, type,
- TREE_OPERAND (arg0, 0),
- TREE_OPERAND (arg1, 0))),
- TREE_OPERAND (arg0, 1)));
- }
+ when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
- else if (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
- || flag_unsafe_math_optimizations)
- {
- /* Except with IEEE floating point, 0-x equals -x. */
- if (! wins && real_zerop (arg0))
- return negate_expr (convert (type, arg1));
- /* Except with IEEE floating point, x-0 equals x. */
- if (real_zerop (arg1))
- return non_lvalue (convert (type, arg0));
- }
+ This code also handles discovering that
- /* Fold &x - &x. This can happen from &x.foo - &x.
- This is unsafe for certain floats even in non-IEEE formats.
- In IEEE, it is unsafe because it does wrong for NaNs.
- Also note that operand_equal_p is always false if an operand
- is volatile. */
+ SAVE_EXPR (I) * SAVE_EXPR (J * 8)
- if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
- && operand_equal_p (arg0, arg1, 0))
- return convert (type, integer_zero_node);
+ is a multiple of 8 so we don't have to worry about dealing with a
+ possible remainder.
- goto associate;
+ Note that we *look* inside a SAVE_EXPR only to determine how it was
+ calculated; it is not safe for fold to do much of anything else with the
+ internals of a SAVE_EXPR, since it cannot know when it will be evaluated
+ at run time. For example, the latter example above *cannot* be implemented
+ as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
+ evaluation time of the original SAVE_EXPR is not necessarily the same at
+ the time the new expression is evaluated. The only optimization of this
+ sort that would be valid is changing
- case MULT_EXPR:
- /* (-A) * (-B) -> A * B */
- if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
- return fold (build (MULT_EXPR, type, TREE_OPERAND (arg0, 0),
- TREE_OPERAND (arg1, 0)));
+ SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
- if (! FLOAT_TYPE_P (type))
- {
- if (integer_zerop (arg1))
- return omit_one_operand (type, arg1, arg0);
- if (integer_onep (arg1))
- return non_lvalue (convert (type, arg0));
+ divided by 8 to
- /* (a * (1 << b)) is (a << b) */
- if (TREE_CODE (arg1) == LSHIFT_EXPR
- && integer_onep (TREE_OPERAND (arg1, 0)))
- return fold (build (LSHIFT_EXPR, type, arg0,
- TREE_OPERAND (arg1, 1)));
- if (TREE_CODE (arg0) == LSHIFT_EXPR
- && integer_onep (TREE_OPERAND (arg0, 0)))
- return fold (build (LSHIFT_EXPR, type, arg1,
- TREE_OPERAND (arg0, 1)));
+ SAVE_EXPR (I) * SAVE_EXPR (J)
- if (TREE_CODE (arg1) == INTEGER_CST
- && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
- code, NULL_TREE)))
- return convert (type, tem);
+ (where the same SAVE_EXPR (J) is used in the original and the
+ transformed version). */
- }
- else
- {
- /* x*0 is 0, except for IEEE floating point. */
- if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
- || flag_unsafe_math_optimizations)
- && real_zerop (arg1))
- return omit_one_operand (type, arg1, arg0);
- /* In IEEE floating point, x*1 is not equivalent to x for snans.
- However, ANSI says we can drop signals,
- so we can do this anyway. */
- if (real_onep (arg1))
- return non_lvalue (convert (type, arg0));
- /* x*2 is x+x */
- if (! wins && real_twop (arg1) && global_bindings_p () == 0
- && ! contains_placeholder_p (arg0))
- {
- tree arg = save_expr (arg0);
- return build (PLUS_EXPR, type, arg, arg);
- }
- }
- goto associate;
+int
+multiple_of_p (tree type, const_tree top, const_tree bottom)
+{
+ if (operand_equal_p (top, bottom, 0))
+ return 1;
- case BIT_IOR_EXPR:
- bit_ior:
- if (integer_all_onesp (arg1))
- return omit_one_operand (type, arg1, arg0);
- if (integer_zerop (arg1))
- return non_lvalue (convert (type, arg0));
- t1 = distribute_bit_expr (code, type, arg0, arg1);
- if (t1 != NULL_TREE)
- return t1;
+ if (TREE_CODE (type) != INTEGER_TYPE)
+ return 0;
- /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
+ switch (TREE_CODE (top))
+ {
+ case BIT_AND_EXPR:
+ /* Bitwise and provides a power of two multiple. If the mask is
+ a multiple of BOTTOM then TOP is a multiple of BOTTOM. */
+ if (!integer_pow2p (bottom))
+ return 0;
+ /* FALLTHRU */
- This results in more efficient code for machines without a NAND
- instruction. Combine will canonicalize to the first form
- which will allow use of NAND instructions provided by the
- backend if they exist. */
- if (TREE_CODE (arg0) == BIT_NOT_EXPR
- && TREE_CODE (arg1) == BIT_NOT_EXPR)
+ case MULT_EXPR:
+ return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
+ || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
+
+ case PLUS_EXPR:
+ case MINUS_EXPR:
+ return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
+ && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
+
+ case LSHIFT_EXPR:
+ if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
{
- return fold (build1 (BIT_NOT_EXPR, type,
- build (BIT_AND_EXPR, type,
- TREE_OPERAND (arg0, 0),
- TREE_OPERAND (arg1, 0))));
+ tree op1, t1;
+
+ op1 = TREE_OPERAND (top, 1);
+ /* const_binop may not detect overflow correctly,
+ so check for it explicitly here. */
+ if (TYPE_PRECISION (TREE_TYPE (size_one_node))
+ > TREE_INT_CST_LOW (op1)
+ && TREE_INT_CST_HIGH (op1) == 0
+ && 0 != (t1 = fold_convert (type,
+ const_binop (LSHIFT_EXPR,
+ size_one_node,
+ op1, 0)))
+ && !TREE_OVERFLOW (t1))
+ return multiple_of_p (type, t1, bottom);
}
+ return 0;
- /* See if this can be simplified into a rotate first. If that
- is unsuccessful continue in the association code. */
- goto bit_rotate;
+ case NOP_EXPR:
+ /* Can't handle conversions from non-integral or wider integral type. */
+ if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
+ || (TYPE_PRECISION (type)
+ < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
+ return 0;
- case BIT_XOR_EXPR:
- if (integer_zerop (arg1))
- return non_lvalue (convert (type, arg0));
- if (integer_all_onesp (arg1))
- return fold (build1 (BIT_NOT_EXPR, type, arg0));
+ /* .. fall through ... */
- /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
- with a constant, and the two constants have no bits in common,
- we should treat this as a BIT_IOR_EXPR since this may produce more
- simplifications. */
- if (TREE_CODE (arg0) == BIT_AND_EXPR
- && TREE_CODE (arg1) == BIT_AND_EXPR
- && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
- && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
- && integer_zerop (const_binop (BIT_AND_EXPR,
- TREE_OPERAND (arg0, 1),
- TREE_OPERAND (arg1, 1), 0)))
- {
- code = BIT_IOR_EXPR;
- goto bit_ior;
- }
+ case SAVE_EXPR:
+ return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
- /* See if this can be simplified into a rotate first. If that
- is unsuccessful continue in the association code. */
- goto bit_rotate;
+ case INTEGER_CST:
+ if (TREE_CODE (bottom) != INTEGER_CST
+ || integer_zerop (bottom)
+ || (TYPE_UNSIGNED (type)
+ && (tree_int_cst_sgn (top) < 0
+ || tree_int_cst_sgn (bottom) < 0)))
+ return 0;
+ return integer_zerop (int_const_binop (TRUNC_MOD_EXPR,
+ top, bottom, 0));
- case BIT_AND_EXPR:
- bit_and:
- if (integer_all_onesp (arg1))
- return non_lvalue (convert (type, arg0));
- if (integer_zerop (arg1))
- return omit_one_operand (type, arg1, arg0);
- t1 = distribute_bit_expr (code, type, arg0, arg1);
- if (t1 != NULL_TREE)
- return t1;
- /* Simplify ((int)c & 0x377) into (int)c, if c is unsigned char. */
- if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == NOP_EXPR
- && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg1, 0))))
- {
- unsigned int prec
- = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg1, 0)));
+ default:
+ return 0;
+ }
+}
- if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
- && (~TREE_INT_CST_LOW (arg0)
- & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
- return build1 (NOP_EXPR, type, TREE_OPERAND (arg1, 0));
- }
- if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
- && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
- {
- unsigned int prec
- = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
+/* Return true if CODE or TYPE is known to be non-negative. */
- if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
- && (~TREE_INT_CST_LOW (arg1)
- & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
- return build1 (NOP_EXPR, type, TREE_OPERAND (arg0, 0));
+static bool
+tree_simple_nonnegative_warnv_p (enum tree_code code, tree type)
+{
+ if ((TYPE_PRECISION (type) != 1 || TYPE_UNSIGNED (type))
+ && truth_value_p (code))
+ /* Truth values evaluate to 0 or 1, which is nonnegative unless we
+ have a signed:1 type (where the value is -1 and 0). */
+ return true;
+ return false;
+}
+
+/* Return true if (CODE OP0) is known to be non-negative. If the return
+ value is based on the assumption that signed overflow is undefined,
+ set *STRICT_OVERFLOW_P to true; otherwise, don't change
+ *STRICT_OVERFLOW_P. */
+
+bool
+tree_unary_nonnegative_warnv_p (enum tree_code code, tree type, tree op0,
+ bool *strict_overflow_p)
+{
+ if (TYPE_UNSIGNED (type))
+ return true;
+
+ switch (code)
+ {
+ case ABS_EXPR:
+ /* We can't return 1 if flag_wrapv is set because
+ ABS_EXPR<INT_MIN> = INT_MIN. */
+ if (!INTEGRAL_TYPE_P (type))
+ return true;
+ if (TYPE_OVERFLOW_UNDEFINED (type))
+ {
+ *strict_overflow_p = true;
+ return true;
}
+ break;
- /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
+ case NON_LVALUE_EXPR:
+ case FLOAT_EXPR:
+ case FIX_TRUNC_EXPR:
+ return tree_expr_nonnegative_warnv_p (op0,
+ strict_overflow_p);
- This results in more efficient code for machines without a NOR
- instruction. Combine will canonicalize to the first form
- which will allow use of NOR instructions provided by the
- backend if they exist. */
- if (TREE_CODE (arg0) == BIT_NOT_EXPR
- && TREE_CODE (arg1) == BIT_NOT_EXPR)
- {
- return fold (build1 (BIT_NOT_EXPR, type,
- build (BIT_IOR_EXPR, type,
- TREE_OPERAND (arg0, 0),
- TREE_OPERAND (arg1, 0))));
- }
+ case NOP_EXPR:
+ {
+ tree inner_type = TREE_TYPE (op0);
+ tree outer_type = type;
- goto associate;
+ if (TREE_CODE (outer_type) == REAL_TYPE)
+ {
+ if (TREE_CODE (inner_type) == REAL_TYPE)
+ return tree_expr_nonnegative_warnv_p (op0,
+ strict_overflow_p);
+ if (TREE_CODE (inner_type) == INTEGER_TYPE)
+ {
+ if (TYPE_UNSIGNED (inner_type))
+ return true;
+ return tree_expr_nonnegative_warnv_p (op0,
+ strict_overflow_p);
+ }
+ }
+ else if (TREE_CODE (outer_type) == INTEGER_TYPE)
+ {
+ if (TREE_CODE (inner_type) == REAL_TYPE)
+ return tree_expr_nonnegative_warnv_p (op0,
+ strict_overflow_p);
+ if (TREE_CODE (inner_type) == INTEGER_TYPE)
+ return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
+ && TYPE_UNSIGNED (inner_type);
+ }
+ }
+ break;
- case BIT_ANDTC_EXPR:
- if (integer_all_onesp (arg0))
- return non_lvalue (convert (type, arg1));
- if (integer_zerop (arg0))
- return omit_one_operand (type, arg0, arg1);
- if (TREE_CODE (arg1) == INTEGER_CST)
- {
- arg1 = fold (build1 (BIT_NOT_EXPR, type, arg1));
- code = BIT_AND_EXPR;
- goto bit_and;
- }
- goto binary;
+ default:
+ return tree_simple_nonnegative_warnv_p (code, type);
+ }
- case RDIV_EXPR:
- /* In most cases, do nothing with a divide by zero. */
-#if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
-#ifndef REAL_INFINITY
- if (TREE_CODE (arg1) == REAL_CST && real_zerop (arg1))
- return t;
-#endif
-#endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
+ /* We don't know sign of `t', so be conservative and return false. */
+ return false;
+}
- /* (-A) / (-B) -> A / B */
- if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
- return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
- TREE_OPERAND (arg1, 0)));
+/* Return true if (CODE OP0 OP1) is known to be non-negative. If the return
+ value is based on the assumption that signed overflow is undefined,
+ set *STRICT_OVERFLOW_P to true; otherwise, don't change
+ *STRICT_OVERFLOW_P. */
- /* In IEEE floating point, x/1 is not equivalent to x for snans.
- However, ANSI says we can drop signals, so we can do this anyway. */
- if (real_onep (arg1))
- return non_lvalue (convert (type, arg0));
+bool
+tree_binary_nonnegative_warnv_p (enum tree_code code, tree type, tree op0,
+ tree op1, bool *strict_overflow_p)
+{
+ if (TYPE_UNSIGNED (type))
+ return true;
- /* If ARG1 is a constant, we can convert this to a multiply by the
- reciprocal. This does not have the same rounding properties,
- so only do this if -funsafe-math-optimizations. We can actually
- always safely do it if ARG1 is a power of two, but it's hard to
- tell if it is or not in a portable manner. */
- if (TREE_CODE (arg1) == REAL_CST)
+ switch (code)
+ {
+ case POINTER_PLUS_EXPR:
+ case PLUS_EXPR:
+ if (FLOAT_TYPE_P (type))
+ return (tree_expr_nonnegative_warnv_p (op0,
+ strict_overflow_p)
+ && tree_expr_nonnegative_warnv_p (op1,
+ strict_overflow_p));
+
+ /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
+ both unsigned and at least 2 bits shorter than the result. */
+ if (TREE_CODE (type) == INTEGER_TYPE
+ && TREE_CODE (op0) == NOP_EXPR
+ && TREE_CODE (op1) == NOP_EXPR)
{
- if (flag_unsafe_math_optimizations
- && 0 != (tem = const_binop (code, build_real (type, dconst1),
- arg1, 0)))
- return fold (build (MULT_EXPR, type, arg0, tem));
- /* Find the reciprocal if optimizing and the result is exact. */
- else if (optimize)
+ tree inner1 = TREE_TYPE (TREE_OPERAND (op0, 0));
+ tree inner2 = TREE_TYPE (TREE_OPERAND (op1, 0));
+ if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
+ && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
{
- REAL_VALUE_TYPE r;
- r = TREE_REAL_CST (arg1);
- if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
- {
- tem = build_real (type, r);
- return fold (build (MULT_EXPR, type, arg0, tem));
- }
+ unsigned int prec = MAX (TYPE_PRECISION (inner1),
+ TYPE_PRECISION (inner2)) + 1;
+ return prec < TYPE_PRECISION (type);
}
}
- /* Convert A/B/C to A/(B*C). */
- if (flag_unsafe_math_optimizations
- && TREE_CODE (arg0) == RDIV_EXPR)
+ break;
+
+ case MULT_EXPR:
+ if (FLOAT_TYPE_P (type))
{
- return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
- build (MULT_EXPR, type, TREE_OPERAND (arg0, 1),
- arg1)));
+ /* x * x for floating point x is always non-negative. */
+ if (operand_equal_p (op0, op1, 0))
+ return true;
+ return (tree_expr_nonnegative_warnv_p (op0,
+ strict_overflow_p)
+ && tree_expr_nonnegative_warnv_p (op1,
+ strict_overflow_p));
}
- /* Convert A/(B/C) to (A/B)*C. */
- if (flag_unsafe_math_optimizations
- && TREE_CODE (arg1) == RDIV_EXPR)
+
+ /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
+ both unsigned and their total bits is shorter than the result. */
+ if (TREE_CODE (type) == INTEGER_TYPE
+ && (TREE_CODE (op0) == NOP_EXPR || TREE_CODE (op0) == INTEGER_CST)
+ && (TREE_CODE (op1) == NOP_EXPR || TREE_CODE (op1) == INTEGER_CST))
{
- return fold (build (MULT_EXPR, type,
- build (RDIV_EXPR, type, arg0,
- TREE_OPERAND (arg1, 0)),
- TREE_OPERAND (arg1, 1)));
- }
- goto binary;
+ tree inner0 = (TREE_CODE (op0) == NOP_EXPR)
+ ? TREE_TYPE (TREE_OPERAND (op0, 0))
+ : TREE_TYPE (op0);
+ tree inner1 = (TREE_CODE (op1) == NOP_EXPR)
+ ? TREE_TYPE (TREE_OPERAND (op1, 0))
+ : TREE_TYPE (op1);
- case TRUNC_DIV_EXPR:
- case ROUND_DIV_EXPR:
- case FLOOR_DIV_EXPR:
- case CEIL_DIV_EXPR:
- case EXACT_DIV_EXPR:
- if (integer_onep (arg1))
- return non_lvalue (convert (type, arg0));
- if (integer_zerop (arg1))
- return t;
+ bool unsigned0 = TYPE_UNSIGNED (inner0);
+ bool unsigned1 = TYPE_UNSIGNED (inner1);
- /* If arg0 is a multiple of arg1, then rewrite to the fastest div
- operation, EXACT_DIV_EXPR.
+ if (TREE_CODE (op0) == INTEGER_CST)
+ unsigned0 = unsigned0 || tree_int_cst_sgn (op0) >= 0;
- Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
- At one time others generated faster code, it's not clear if they do
- after the last round to changes to the DIV code in expmed.c. */
- if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
- && multiple_of_p (type, arg0, arg1))
- return fold (build (EXACT_DIV_EXPR, type, arg0, arg1));
+ if (TREE_CODE (op1) == INTEGER_CST)
+ unsigned1 = unsigned1 || tree_int_cst_sgn (op1) >= 0;
- if (TREE_CODE (arg1) == INTEGER_CST
- && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
- code, NULL_TREE)))
- return convert (type, tem);
+ if (TREE_CODE (inner0) == INTEGER_TYPE && unsigned0
+ && TREE_CODE (inner1) == INTEGER_TYPE && unsigned1)
+ {
+ unsigned int precision0 = (TREE_CODE (op0) == INTEGER_CST)
+ ? tree_int_cst_min_precision (op0, /*unsignedp=*/true)
+ : TYPE_PRECISION (inner0);
+
+ unsigned int precision1 = (TREE_CODE (op1) == INTEGER_CST)
+ ? tree_int_cst_min_precision (op1, /*unsignedp=*/true)
+ : TYPE_PRECISION (inner1);
+
+ return precision0 + precision1 < TYPE_PRECISION (type);
+ }
+ }
+ return false;
- goto binary;
+ case BIT_AND_EXPR:
+ case MAX_EXPR:
+ return (tree_expr_nonnegative_warnv_p (op0,
+ strict_overflow_p)
+ || tree_expr_nonnegative_warnv_p (op1,
+ strict_overflow_p));
+
+ case BIT_IOR_EXPR:
+ case BIT_XOR_EXPR:
+ case MIN_EXPR:
+ case RDIV_EXPR:
+ case TRUNC_DIV_EXPR:
+ case CEIL_DIV_EXPR:
+ case FLOOR_DIV_EXPR:
+ case ROUND_DIV_EXPR:
+ return (tree_expr_nonnegative_warnv_p (op0,
+ strict_overflow_p)
+ && tree_expr_nonnegative_warnv_p (op1,
+ strict_overflow_p));
+ case TRUNC_MOD_EXPR:
case CEIL_MOD_EXPR:
case FLOOR_MOD_EXPR:
case ROUND_MOD_EXPR:
- case TRUNC_MOD_EXPR:
- if (integer_onep (arg1))
- return omit_one_operand (type, integer_zero_node, arg0);
- if (integer_zerop (arg1))
- return t;
+ return tree_expr_nonnegative_warnv_p (op0,
+ strict_overflow_p);
+ default:
+ return tree_simple_nonnegative_warnv_p (code, type);
+ }
- if (TREE_CODE (arg1) == INTEGER_CST
- && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
- code, NULL_TREE)))
- return convert (type, tem);
+ /* We don't know sign of `t', so be conservative and return false. */
+ return false;
+}
- goto binary;
+/* Return true if T is known to be non-negative. If the return
+ value is based on the assumption that signed overflow is undefined,
+ set *STRICT_OVERFLOW_P to true; otherwise, don't change
+ *STRICT_OVERFLOW_P. */
- case LSHIFT_EXPR:
- case RSHIFT_EXPR:
- case LROTATE_EXPR:
- case RROTATE_EXPR:
- if (integer_zerop (arg1))
- return non_lvalue (convert (type, arg0));
- /* Since negative shift count is not well-defined,
- don't try to compute it in the compiler. */
- if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
- return t;
- /* Rewrite an LROTATE_EXPR by a constant into an
- RROTATE_EXPR by a new constant. */
- if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
- {
- TREE_SET_CODE (t, RROTATE_EXPR);
- code = RROTATE_EXPR;
- TREE_OPERAND (t, 1) = arg1
- = const_binop
- (MINUS_EXPR,
- convert (TREE_TYPE (arg1),
- build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type)), 0)),
- arg1, 0);
- if (tree_int_cst_sgn (arg1) < 0)
- return t;
- }
+bool
+tree_single_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
+{
+ if (TYPE_UNSIGNED (TREE_TYPE (t)))
+ return true;
- /* If we have a rotate of a bit operation with the rotate count and
- the second operand of the bit operation both constant,
- permute the two operations. */
- if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
- && (TREE_CODE (arg0) == BIT_AND_EXPR
- || TREE_CODE (arg0) == BIT_ANDTC_EXPR
- || TREE_CODE (arg0) == BIT_IOR_EXPR
- || TREE_CODE (arg0) == BIT_XOR_EXPR)
- && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
- return fold (build (TREE_CODE (arg0), type,
- fold (build (code, type,
- TREE_OPERAND (arg0, 0), arg1)),
- fold (build (code, type,
- TREE_OPERAND (arg0, 1), arg1))));
-
- /* Two consecutive rotates adding up to the width of the mode can
- be ignored. */
- if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
- && TREE_CODE (arg0) == RROTATE_EXPR
- && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
- && TREE_INT_CST_HIGH (arg1) == 0
- && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
- && ((TREE_INT_CST_LOW (arg1)
- + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
- == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
- return TREE_OPERAND (arg0, 0);
+ switch (TREE_CODE (t))
+ {
+ case INTEGER_CST:
+ return tree_int_cst_sgn (t) >= 0;
- goto binary;
+ case REAL_CST:
+ return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
- case MIN_EXPR:
- if (operand_equal_p (arg0, arg1, 0))
- return omit_one_operand (type, arg0, arg1);
- if (INTEGRAL_TYPE_P (type)
- && operand_equal_p (arg1, TYPE_MIN_VALUE (type), 1))
- return omit_one_operand (type, arg1, arg0);
- goto associate;
+ case FIXED_CST:
+ return ! FIXED_VALUE_NEGATIVE (TREE_FIXED_CST (t));
- case MAX_EXPR:
- if (operand_equal_p (arg0, arg1, 0))
- return omit_one_operand (type, arg0, arg1);
- if (INTEGRAL_TYPE_P (type)
- && TYPE_MAX_VALUE (type)
- && operand_equal_p (arg1, TYPE_MAX_VALUE (type), 1))
- return omit_one_operand (type, arg1, arg0);
- goto associate;
+ case COND_EXPR:
+ return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
+ strict_overflow_p)
+ && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 2),
+ strict_overflow_p));
+ default:
+ return tree_simple_nonnegative_warnv_p (TREE_CODE (t),
+ TREE_TYPE (t));
+ }
+ /* We don't know sign of `t', so be conservative and return false. */
+ return false;
+}
- case TRUTH_NOT_EXPR:
- /* Note that the operand of this must be an int
- and its values must be 0 or 1.
- ("true" is a fixed value perhaps depending on the language,
- but we don't handle values other than 1 correctly yet.) */
- tem = invert_truthvalue (arg0);
- /* Avoid infinite recursion. */
- if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
- return t;
- return convert (type, tem);
+/* Return true if T is known to be non-negative. If the return
+ value is based on the assumption that signed overflow is undefined,
+ set *STRICT_OVERFLOW_P to true; otherwise, don't change
+ *STRICT_OVERFLOW_P. */
- case TRUTH_ANDIF_EXPR:
- /* Note that the operands of this must be ints
- and their values must be 0 or 1.
- ("true" is a fixed value perhaps depending on the language.) */
- /* If first arg is constant zero, return it. */
- if (integer_zerop (arg0))
- return convert (type, arg0);
+bool
+tree_call_nonnegative_warnv_p (tree type, tree fndecl,
+ tree arg0, tree arg1, bool *strict_overflow_p)
+{
+ if (fndecl && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
+ switch (DECL_FUNCTION_CODE (fndecl))
+ {
+ CASE_FLT_FN (BUILT_IN_ACOS):
+ CASE_FLT_FN (BUILT_IN_ACOSH):
+ CASE_FLT_FN (BUILT_IN_CABS):
+ CASE_FLT_FN (BUILT_IN_COSH):
+ CASE_FLT_FN (BUILT_IN_ERFC):
+ CASE_FLT_FN (BUILT_IN_EXP):
+ CASE_FLT_FN (BUILT_IN_EXP10):
+ CASE_FLT_FN (BUILT_IN_EXP2):
+ CASE_FLT_FN (BUILT_IN_FABS):
+ CASE_FLT_FN (BUILT_IN_FDIM):
+ CASE_FLT_FN (BUILT_IN_HYPOT):
+ CASE_FLT_FN (BUILT_IN_POW10):
+ CASE_INT_FN (BUILT_IN_FFS):
+ CASE_INT_FN (BUILT_IN_PARITY):
+ CASE_INT_FN (BUILT_IN_POPCOUNT):
+ case BUILT_IN_BSWAP32:
+ case BUILT_IN_BSWAP64:
+ /* Always true. */
+ return true;
+
+ CASE_FLT_FN (BUILT_IN_SQRT):
+ /* sqrt(-0.0) is -0.0. */
+ if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
+ return true;
+ return tree_expr_nonnegative_warnv_p (arg0,
+ strict_overflow_p);
+
+ CASE_FLT_FN (BUILT_IN_ASINH):
+ CASE_FLT_FN (BUILT_IN_ATAN):
+ CASE_FLT_FN (BUILT_IN_ATANH):
+ CASE_FLT_FN (BUILT_IN_CBRT):
+ CASE_FLT_FN (BUILT_IN_CEIL):
+ CASE_FLT_FN (BUILT_IN_ERF):
+ CASE_FLT_FN (BUILT_IN_EXPM1):
+ CASE_FLT_FN (BUILT_IN_FLOOR):
+ CASE_FLT_FN (BUILT_IN_FMOD):
+ CASE_FLT_FN (BUILT_IN_FREXP):
+ CASE_FLT_FN (BUILT_IN_LCEIL):
+ CASE_FLT_FN (BUILT_IN_LDEXP):
+ CASE_FLT_FN (BUILT_IN_LFLOOR):
+ CASE_FLT_FN (BUILT_IN_LLCEIL):
+ CASE_FLT_FN (BUILT_IN_LLFLOOR):
+ CASE_FLT_FN (BUILT_IN_LLRINT):
+ CASE_FLT_FN (BUILT_IN_LLROUND):
+ CASE_FLT_FN (BUILT_IN_LRINT):
+ CASE_FLT_FN (BUILT_IN_LROUND):
+ CASE_FLT_FN (BUILT_IN_MODF):
+ CASE_FLT_FN (BUILT_IN_NEARBYINT):
+ CASE_FLT_FN (BUILT_IN_RINT):
+ CASE_FLT_FN (BUILT_IN_ROUND):
+ CASE_FLT_FN (BUILT_IN_SCALB):
+ CASE_FLT_FN (BUILT_IN_SCALBLN):
+ CASE_FLT_FN (BUILT_IN_SCALBN):
+ CASE_FLT_FN (BUILT_IN_SIGNBIT):
+ CASE_FLT_FN (BUILT_IN_SIGNIFICAND):
+ CASE_FLT_FN (BUILT_IN_SINH):
+ CASE_FLT_FN (BUILT_IN_TANH):
+ CASE_FLT_FN (BUILT_IN_TRUNC):
+ /* True if the 1st argument is nonnegative. */
+ return tree_expr_nonnegative_warnv_p (arg0,
+ strict_overflow_p);
+
+ CASE_FLT_FN (BUILT_IN_FMAX):
+ /* True if the 1st OR 2nd arguments are nonnegative. */
+ return (tree_expr_nonnegative_warnv_p (arg0,
+ strict_overflow_p)
+ || (tree_expr_nonnegative_warnv_p (arg1,
+ strict_overflow_p)));
+
+ CASE_FLT_FN (BUILT_IN_FMIN):
+ /* True if the 1st AND 2nd arguments are nonnegative. */
+ return (tree_expr_nonnegative_warnv_p (arg0,
+ strict_overflow_p)
+ && (tree_expr_nonnegative_warnv_p (arg1,
+ strict_overflow_p)));
+
+ CASE_FLT_FN (BUILT_IN_COPYSIGN):
+ /* True if the 2nd argument is nonnegative. */
+ return tree_expr_nonnegative_warnv_p (arg1,
+ strict_overflow_p);
+
+ CASE_FLT_FN (BUILT_IN_POWI):
+ /* True if the 1st argument is nonnegative or the second
+ argument is an even integer. */
+ if (TREE_CODE (arg1) == INTEGER_CST
+ && (TREE_INT_CST_LOW (arg1) & 1) == 0)
+ return true;
+ return tree_expr_nonnegative_warnv_p (arg0,
+ strict_overflow_p);
+
+ CASE_FLT_FN (BUILT_IN_POW):
+ /* True if the 1st argument is nonnegative or the second
+ argument is an even integer valued real. */
+ if (TREE_CODE (arg1) == REAL_CST)
+ {
+ REAL_VALUE_TYPE c;
+ HOST_WIDE_INT n;
+
+ c = TREE_REAL_CST (arg1);
+ n = real_to_integer (&c);
+ if ((n & 1) == 0)
+ {
+ REAL_VALUE_TYPE cint;
+ real_from_integer (&cint, VOIDmode, n,
+ n < 0 ? -1 : 0, 0);
+ if (real_identical (&c, &cint))
+ return true;
+ }
+ }
+ return tree_expr_nonnegative_warnv_p (arg0,
+ strict_overflow_p);
+
+ default:
+ break;
+ }
+ return tree_simple_nonnegative_warnv_p (CALL_EXPR,
+ type);
+}
+
+/* Return true if T is known to be non-negative. If the return
+ value is based on the assumption that signed overflow is undefined,
+ set *STRICT_OVERFLOW_P to true; otherwise, don't change
+ *STRICT_OVERFLOW_P. */
+
+bool
+tree_invalid_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
+{
+ enum tree_code code = TREE_CODE (t);
+ if (TYPE_UNSIGNED (TREE_TYPE (t)))
+ return true;
+
+ switch (code)
+ {
+ case TARGET_EXPR:
+ {
+ tree temp = TARGET_EXPR_SLOT (t);
+ t = TARGET_EXPR_INITIAL (t);
+
+ /* If the initializer is non-void, then it's a normal expression
+ that will be assigned to the slot. */
+ if (!VOID_TYPE_P (t))
+ return tree_expr_nonnegative_warnv_p (t, strict_overflow_p);
+
+ /* Otherwise, the initializer sets the slot in some way. One common
+ way is an assignment statement at the end of the initializer. */
+ while (1)
+ {
+ if (TREE_CODE (t) == BIND_EXPR)
+ t = expr_last (BIND_EXPR_BODY (t));
+ else if (TREE_CODE (t) == TRY_FINALLY_EXPR
+ || TREE_CODE (t) == TRY_CATCH_EXPR)
+ t = expr_last (TREE_OPERAND (t, 0));
+ else if (TREE_CODE (t) == STATEMENT_LIST)
+ t = expr_last (t);
+ else
+ break;
+ }
+ if (TREE_CODE (t) == MODIFY_EXPR
+ && TREE_OPERAND (t, 0) == temp)
+ return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
+ strict_overflow_p);
+
+ return false;
+ }
+
+ case CALL_EXPR:
+ {
+ tree arg0 = call_expr_nargs (t) > 0 ? CALL_EXPR_ARG (t, 0) : NULL_TREE;
+ tree arg1 = call_expr_nargs (t) > 1 ? CALL_EXPR_ARG (t, 1) : NULL_TREE;
+
+ return tree_call_nonnegative_warnv_p (TREE_TYPE (t),
+ get_callee_fndecl (t),
+ arg0,
+ arg1,
+ strict_overflow_p);
+ }
+ case COMPOUND_EXPR:
+ case MODIFY_EXPR:
+ return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
+ strict_overflow_p);
+ case BIND_EXPR:
+ return tree_expr_nonnegative_warnv_p (expr_last (TREE_OPERAND (t, 1)),
+ strict_overflow_p);
+ case SAVE_EXPR:
+ return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
+ strict_overflow_p);
+
+ default:
+ return tree_simple_nonnegative_warnv_p (TREE_CODE (t),
+ TREE_TYPE (t));
+ }
+
+ /* We don't know sign of `t', so be conservative and return false. */
+ return false;
+}
+
+/* Return true if T is known to be non-negative. If the return
+ value is based on the assumption that signed overflow is undefined,
+ set *STRICT_OVERFLOW_P to true; otherwise, don't change
+ *STRICT_OVERFLOW_P. */
+
+bool
+tree_expr_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
+{
+ enum tree_code code;
+ if (t == error_mark_node)
+ return false;
+
+ code = TREE_CODE (t);
+ switch (TREE_CODE_CLASS (code))
+ {
+ case tcc_binary:
+ case tcc_comparison:
+ return tree_binary_nonnegative_warnv_p (TREE_CODE (t),
+ TREE_TYPE (t),
+ TREE_OPERAND (t, 0),
+ TREE_OPERAND (t, 1),
+ strict_overflow_p);
+
+ case tcc_unary:
+ return tree_unary_nonnegative_warnv_p (TREE_CODE (t),
+ TREE_TYPE (t),
+ TREE_OPERAND (t, 0),
+ strict_overflow_p);
+
+ case tcc_constant:
+ case tcc_declaration:
+ case tcc_reference:
+ return tree_single_nonnegative_warnv_p (t, strict_overflow_p);
+
+ default:
+ break;
+ }
+
+ switch (code)
+ {
case TRUTH_AND_EXPR:
- /* If either arg is constant true, drop it. */
- if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
- return non_lvalue (convert (type, arg1));
- if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
- /* Preserve sequence points. */
- && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
- return non_lvalue (convert (type, arg0));
- /* If second arg is constant zero, result is zero, but first arg
- must be evaluated. */
- if (integer_zerop (arg1))
- return omit_one_operand (type, arg1, arg0);
- /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
- case will be handled here. */
- if (integer_zerop (arg0))
- return omit_one_operand (type, arg0, arg1);
+ case TRUTH_OR_EXPR:
+ case TRUTH_XOR_EXPR:
+ return tree_binary_nonnegative_warnv_p (TREE_CODE (t),
+ TREE_TYPE (t),
+ TREE_OPERAND (t, 0),
+ TREE_OPERAND (t, 1),
+ strict_overflow_p);
+ case TRUTH_NOT_EXPR:
+ return tree_unary_nonnegative_warnv_p (TREE_CODE (t),
+ TREE_TYPE (t),
+ TREE_OPERAND (t, 0),
+ strict_overflow_p);
+
+ case COND_EXPR:
+ case CONSTRUCTOR:
+ case OBJ_TYPE_REF:
+ case ASSERT_EXPR:
+ case ADDR_EXPR:
+ case WITH_SIZE_EXPR:
+ case EXC_PTR_EXPR:
+ case SSA_NAME:
+ case FILTER_EXPR:
+ return tree_single_nonnegative_warnv_p (t, strict_overflow_p);
+
+ default:
+ return tree_invalid_nonnegative_warnv_p (t, strict_overflow_p);
+ }
+}
+
+/* Return true if `t' is known to be non-negative. Handle warnings
+ about undefined signed overflow. */
+
+bool
+tree_expr_nonnegative_p (tree t)
+{
+ bool ret, strict_overflow_p;
+
+ strict_overflow_p = false;
+ ret = tree_expr_nonnegative_warnv_p (t, &strict_overflow_p);
+ if (strict_overflow_p)
+ fold_overflow_warning (("assuming signed overflow does not occur when "
+ "determining that expression is always "
+ "non-negative"),
+ WARN_STRICT_OVERFLOW_MISC);
+ return ret;
+}
- truth_andor:
- /* We only do these simplifications if we are optimizing. */
- if (!optimize)
- return t;
- /* Check for things like (A || B) && (A || C). We can convert this
- to A || (B && C). Note that either operator can be any of the four
- truth and/or operations and the transformation will still be
- valid. Also note that we only care about order for the
- ANDIF and ORIF operators. If B contains side effects, this
- might change the truth-value of A. */
- if (TREE_CODE (arg0) == TREE_CODE (arg1)
- && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
- || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
- || TREE_CODE (arg0) == TRUTH_AND_EXPR
- || TREE_CODE (arg0) == TRUTH_OR_EXPR)
- && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
- {
- tree a00 = TREE_OPERAND (arg0, 0);
- tree a01 = TREE_OPERAND (arg0, 1);
- tree a10 = TREE_OPERAND (arg1, 0);
- tree a11 = TREE_OPERAND (arg1, 1);
- int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
- || TREE_CODE (arg0) == TRUTH_AND_EXPR)
- && (code == TRUTH_AND_EXPR
- || code == TRUTH_OR_EXPR));
+/* Return true when (CODE OP0) is an address and is known to be nonzero.
+ For floating point we further ensure that T is not denormal.
+ Similar logic is present in nonzero_address in rtlanal.h.
- if (operand_equal_p (a00, a10, 0))
- return fold (build (TREE_CODE (arg0), type, a00,
- fold (build (code, type, a01, a11))));
- else if (commutative && operand_equal_p (a00, a11, 0))
- return fold (build (TREE_CODE (arg0), type, a00,
- fold (build (code, type, a01, a10))));
- else if (commutative && operand_equal_p (a01, a10, 0))
- return fold (build (TREE_CODE (arg0), type, a01,
- fold (build (code, type, a00, a11))));
+ If the return value is based on the assumption that signed overflow
+ is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
+ change *STRICT_OVERFLOW_P. */
- /* This case if tricky because we must either have commutative
- operators or else A10 must not have side-effects. */
+bool
+tree_unary_nonzero_warnv_p (enum tree_code code, tree type, tree op0,
+ bool *strict_overflow_p)
+{
+ switch (code)
+ {
+ case ABS_EXPR:
+ return tree_expr_nonzero_warnv_p (op0,
+ strict_overflow_p);
- else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
- && operand_equal_p (a01, a11, 0))
- return fold (build (TREE_CODE (arg0), type,
- fold (build (code, type, a00, a10)),
- a01));
- }
+ case NOP_EXPR:
+ {
+ tree inner_type = TREE_TYPE (op0);
+ tree outer_type = type;
- /* See if we can build a range comparison. */
- if (0 != (tem = fold_range_test (t)))
- return tem;
+ return (TYPE_PRECISION (outer_type) >= TYPE_PRECISION (inner_type)
+ && tree_expr_nonzero_warnv_p (op0,
+ strict_overflow_p));
+ }
+ break;
- /* Check for the possibility of merging component references. If our
- lhs is another similar operation, try to merge its rhs with our
- rhs. Then try to merge our lhs and rhs. */
- if (TREE_CODE (arg0) == code
- && 0 != (tem = fold_truthop (code, type,
- TREE_OPERAND (arg0, 1), arg1)))
- return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
+ case NON_LVALUE_EXPR:
+ return tree_expr_nonzero_warnv_p (op0,
+ strict_overflow_p);
- if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
- return tem;
+ default:
+ break;
+ }
- return t;
+ return false;
+}
- case TRUTH_ORIF_EXPR:
- /* Note that the operands of this must be ints
- and their values must be 0 or true.
- ("true" is a fixed value perhaps depending on the language.) */
- /* If first arg is constant true, return it. */
- if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
- return convert (type, arg0);
- case TRUTH_OR_EXPR:
- /* If either arg is constant zero, drop it. */
- if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
- return non_lvalue (convert (type, arg1));
- if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
- /* Preserve sequence points. */
- && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
- return non_lvalue (convert (type, arg0));
- /* If second arg is constant true, result is true, but we must
- evaluate first arg. */
- if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
- return omit_one_operand (type, arg1, arg0);
- /* Likewise for first arg, but note this only occurs here for
- TRUTH_OR_EXPR. */
- if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
- return omit_one_operand (type, arg0, arg1);
- goto truth_andor;
+/* Return true when (CODE OP0 OP1) is an address and is known to be nonzero.
+ For floating point we further ensure that T is not denormal.
+ Similar logic is present in nonzero_address in rtlanal.h.
- case TRUTH_XOR_EXPR:
- /* If either arg is constant zero, drop it. */
- if (integer_zerop (arg0))
- return non_lvalue (convert (type, arg1));
- if (integer_zerop (arg1))
- return non_lvalue (convert (type, arg0));
- /* If either arg is constant true, this is a logical inversion. */
- if (integer_onep (arg0))
- return non_lvalue (convert (type, invert_truthvalue (arg1)));
- if (integer_onep (arg1))
- return non_lvalue (convert (type, invert_truthvalue (arg0)));
- return t;
+ If the return value is based on the assumption that signed overflow
+ is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
+ change *STRICT_OVERFLOW_P. */
- case EQ_EXPR:
- case NE_EXPR:
- case LT_EXPR:
- case GT_EXPR:
- case LE_EXPR:
- case GE_EXPR:
- if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
+bool
+tree_binary_nonzero_warnv_p (enum tree_code code,
+ tree type,
+ tree op0,
+ tree op1, bool *strict_overflow_p)
+{
+ bool sub_strict_overflow_p;
+ switch (code)
+ {
+ case POINTER_PLUS_EXPR:
+ case PLUS_EXPR:
+ if (TYPE_OVERFLOW_UNDEFINED (type))
{
- /* (-a) CMP (-b) -> b CMP a */
- if (TREE_CODE (arg0) == NEGATE_EXPR
- && TREE_CODE (arg1) == NEGATE_EXPR)
- return fold (build (code, type, TREE_OPERAND (arg1, 0),
- TREE_OPERAND (arg0, 0)));
- /* (-a) CMP CST -> a swap(CMP) (-CST) */
- if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == REAL_CST)
- return
- fold (build
- (swap_tree_comparison (code), type,
- TREE_OPERAND (arg0, 0),
- build_real (TREE_TYPE (arg1),
- REAL_VALUE_NEGATE (TREE_REAL_CST (arg1)))));
- /* IEEE doesn't distinguish +0 and -0 in comparisons. */
- /* a CMP (-0) -> a CMP 0 */
- if (TREE_CODE (arg1) == REAL_CST
- && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (arg1)))
- return fold (build (code, type, arg0,
- build_real (TREE_TYPE (arg1), dconst0)));
+ /* With the presence of negative values it is hard
+ to say something. */
+ sub_strict_overflow_p = false;
+ if (!tree_expr_nonnegative_warnv_p (op0,
+ &sub_strict_overflow_p)
+ || !tree_expr_nonnegative_warnv_p (op1,
+ &sub_strict_overflow_p))
+ return false;
+ /* One of operands must be positive and the other non-negative. */
+ /* We don't set *STRICT_OVERFLOW_P here: even if this value
+ overflows, on a twos-complement machine the sum of two
+ nonnegative numbers can never be zero. */
+ return (tree_expr_nonzero_warnv_p (op0,
+ strict_overflow_p)
+ || tree_expr_nonzero_warnv_p (op1,
+ strict_overflow_p));
}
+ break;
- /* If one arg is a constant integer, put it last. */
- if (TREE_CODE (arg0) == INTEGER_CST
- && TREE_CODE (arg1) != INTEGER_CST)
+ case MULT_EXPR:
+ if (TYPE_OVERFLOW_UNDEFINED (type))
{
- TREE_OPERAND (t, 0) = arg1;
- TREE_OPERAND (t, 1) = arg0;
- arg0 = TREE_OPERAND (t, 0);
- arg1 = TREE_OPERAND (t, 1);
- code = swap_tree_comparison (code);
- TREE_SET_CODE (t, code);
+ if (tree_expr_nonzero_warnv_p (op0,
+ strict_overflow_p)
+ && tree_expr_nonzero_warnv_p (op1,
+ strict_overflow_p))
+ {
+ *strict_overflow_p = true;
+ return true;
+ }
}
+ break;
- /* Convert foo++ == CONST into ++foo == CONST + INCR.
- First, see if one arg is constant; find the constant arg
- and the other one. */
- {
- tree constop = 0, varop = NULL_TREE;
- int constopnum = -1;
+ case MIN_EXPR:
+ sub_strict_overflow_p = false;
+ if (tree_expr_nonzero_warnv_p (op0,
+ &sub_strict_overflow_p)
+ && tree_expr_nonzero_warnv_p (op1,
+ &sub_strict_overflow_p))
+ {
+ if (sub_strict_overflow_p)
+ *strict_overflow_p = true;
+ }
+ break;
- if (TREE_CONSTANT (arg1))
- constopnum = 1, constop = arg1, varop = arg0;
- if (TREE_CONSTANT (arg0))
- constopnum = 0, constop = arg0, varop = arg1;
+ case MAX_EXPR:
+ sub_strict_overflow_p = false;
+ if (tree_expr_nonzero_warnv_p (op0,
+ &sub_strict_overflow_p))
+ {
+ if (sub_strict_overflow_p)
+ *strict_overflow_p = true;
- if (constop && TREE_CODE (varop) == POSTINCREMENT_EXPR)
- {
- /* This optimization is invalid for ordered comparisons
- if CONST+INCR overflows or if foo+incr might overflow.
- This optimization is invalid for floating point due to rounding.
- For pointer types we assume overflow doesn't happen. */
- if (POINTER_TYPE_P (TREE_TYPE (varop))
- || (! FLOAT_TYPE_P (TREE_TYPE (varop))
- && (code == EQ_EXPR || code == NE_EXPR)))
- {
- tree newconst
- = fold (build (PLUS_EXPR, TREE_TYPE (varop),
- constop, TREE_OPERAND (varop, 1)));
-
- /* Do not overwrite the current varop to be a preincrement,
- create a new node so that we won't confuse our caller who
- might create trees and throw them away, reusing the
- arguments that they passed to build. This shows up in
- the THEN or ELSE parts of ?: being postincrements. */
- varop = build (PREINCREMENT_EXPR, TREE_TYPE (varop),
- TREE_OPERAND (varop, 0),
- TREE_OPERAND (varop, 1));
-
- /* If VAROP is a reference to a bitfield, we must mask
- the constant by the width of the field. */
- if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
- && DECL_BIT_FIELD(TREE_OPERAND
- (TREE_OPERAND (varop, 0), 1)))
- {
- int size
- = TREE_INT_CST_LOW (DECL_SIZE
- (TREE_OPERAND
- (TREE_OPERAND (varop, 0), 1)));
- tree mask, unsigned_type;
- unsigned int precision;
- tree folded_compare;
-
- /* First check whether the comparison would come out
- always the same. If we don't do that we would
- change the meaning with the masking. */
- if (constopnum == 0)
- folded_compare = fold (build (code, type, constop,
- TREE_OPERAND (varop, 0)));
- else
- folded_compare = fold (build (code, type,
- TREE_OPERAND (varop, 0),
- constop));
- if (integer_zerop (folded_compare)
- || integer_onep (folded_compare))
- return omit_one_operand (type, folded_compare, varop);
-
- unsigned_type = type_for_size (size, 1);
- precision = TYPE_PRECISION (unsigned_type);
- mask = build_int_2 (~0, ~0);
- TREE_TYPE (mask) = unsigned_type;
- force_fit_type (mask, 0);
- mask = const_binop (RSHIFT_EXPR, mask,
- size_int (precision - size), 0);
- newconst = fold (build (BIT_AND_EXPR,
- TREE_TYPE (varop), newconst,
- convert (TREE_TYPE (varop),
- mask)));
- }
+ /* When both operands are nonzero, then MAX must be too. */
+ if (tree_expr_nonzero_warnv_p (op1,
+ strict_overflow_p))
+ return true;
- t = build (code, type,
- (constopnum == 0) ? newconst : varop,
- (constopnum == 1) ? newconst : varop);
- return t;
- }
- }
- else if (constop && TREE_CODE (varop) == POSTDECREMENT_EXPR)
- {
- if (POINTER_TYPE_P (TREE_TYPE (varop))
- || (! FLOAT_TYPE_P (TREE_TYPE (varop))
- && (code == EQ_EXPR || code == NE_EXPR)))
- {
- tree newconst
- = fold (build (MINUS_EXPR, TREE_TYPE (varop),
- constop, TREE_OPERAND (varop, 1)));
-
- /* Do not overwrite the current varop to be a predecrement,
- create a new node so that we won't confuse our caller who
- might create trees and throw them away, reusing the
- arguments that they passed to build. This shows up in
- the THEN or ELSE parts of ?: being postdecrements. */
- varop = build (PREDECREMENT_EXPR, TREE_TYPE (varop),
- TREE_OPERAND (varop, 0),
- TREE_OPERAND (varop, 1));
-
- if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
- && DECL_BIT_FIELD(TREE_OPERAND
- (TREE_OPERAND (varop, 0), 1)))
- {
- int size
- = TREE_INT_CST_LOW (DECL_SIZE
- (TREE_OPERAND
- (TREE_OPERAND (varop, 0), 1)));
- tree mask, unsigned_type;
- unsigned int precision;
- tree folded_compare;
-
- if (constopnum == 0)
- folded_compare = fold (build (code, type, constop,
- TREE_OPERAND (varop, 0)));
- else
- folded_compare = fold (build (code, type,
- TREE_OPERAND (varop, 0),
- constop));
- if (integer_zerop (folded_compare)
- || integer_onep (folded_compare))
- return omit_one_operand (type, folded_compare, varop);
-
- unsigned_type = type_for_size (size, 1);
- precision = TYPE_PRECISION (unsigned_type);
- mask = build_int_2 (~0, ~0);
- TREE_TYPE (mask) = TREE_TYPE (varop);
- force_fit_type (mask, 0);
- mask = const_binop (RSHIFT_EXPR, mask,
- size_int (precision - size), 0);
- newconst = fold (build (BIT_AND_EXPR,
- TREE_TYPE (varop), newconst,
- convert (TREE_TYPE (varop),
- mask)));
- }
+ /* MAX where operand 0 is positive is positive. */
+ return tree_expr_nonnegative_warnv_p (op0,
+ strict_overflow_p);
+ }
+ /* MAX where operand 1 is positive is positive. */
+ else if (tree_expr_nonzero_warnv_p (op1,
+ &sub_strict_overflow_p)
+ && tree_expr_nonnegative_warnv_p (op1,
+ &sub_strict_overflow_p))
+ {
+ if (sub_strict_overflow_p)
+ *strict_overflow_p = true;
+ return true;
+ }
+ break;
- t = build (code, type,
- (constopnum == 0) ? newconst : varop,
- (constopnum == 1) ? newconst : varop);
- return t;
- }
- }
- }
+ case BIT_IOR_EXPR:
+ return (tree_expr_nonzero_warnv_p (op1,
+ strict_overflow_p)
+ || tree_expr_nonzero_warnv_p (op0,
+ strict_overflow_p));
- /* Comparisons with the highest or lowest possible integer of
- the specified size will have known values and an unsigned
- <= 0x7fffffff can be simplified. */
- {
- int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
+ default:
+ break;
+ }
- if (TREE_CODE (arg1) == INTEGER_CST
- && ! TREE_CONSTANT_OVERFLOW (arg1)
- && width <= HOST_BITS_PER_WIDE_INT
- && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
- || POINTER_TYPE_P (TREE_TYPE (arg1))))
- {
- if (TREE_INT_CST_HIGH (arg1) == 0
- && (TREE_INT_CST_LOW (arg1)
- == ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1)
- && ! TREE_UNSIGNED (TREE_TYPE (arg1)))
- switch (TREE_CODE (t))
- {
- case GT_EXPR:
- return omit_one_operand (type,
- convert (type, integer_zero_node),
- arg0);
- case GE_EXPR:
- TREE_SET_CODE (t, EQ_EXPR);
- break;
+ return false;
+}
- case LE_EXPR:
- return omit_one_operand (type,
- convert (type, integer_one_node),
- arg0);
- case LT_EXPR:
- TREE_SET_CODE (t, NE_EXPR);
- break;
+/* Return true when T is an address and is known to be nonzero.
+ For floating point we further ensure that T is not denormal.
+ Similar logic is present in nonzero_address in rtlanal.h.
- default:
- break;
- }
+ If the return value is based on the assumption that signed overflow
+ is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
+ change *STRICT_OVERFLOW_P. */
- else if (TREE_INT_CST_HIGH (arg1) == -1
- && (TREE_INT_CST_LOW (arg1)
- == ((unsigned HOST_WIDE_INT) -1 << (width - 1)))
- && ! TREE_UNSIGNED (TREE_TYPE (arg1)))
- switch (TREE_CODE (t))
- {
- case LT_EXPR:
- return omit_one_operand (type,
- convert (type, integer_zero_node),
- arg0);
- case LE_EXPR:
- TREE_SET_CODE (t, EQ_EXPR);
- break;
+bool
+tree_single_nonzero_warnv_p (tree t, bool *strict_overflow_p)
+{
+ bool sub_strict_overflow_p;
+ switch (TREE_CODE (t))
+ {
+ case INTEGER_CST:
+ return !integer_zerop (t);
- case GE_EXPR:
- return omit_one_operand (type,
- convert (type, integer_one_node),
- arg0);
- case GT_EXPR:
- TREE_SET_CODE (t, NE_EXPR);
- break;
+ case ADDR_EXPR:
+ {
+ tree base = get_base_address (TREE_OPERAND (t, 0));
- default:
- break;
- }
+ if (!base)
+ return false;
- else if (TREE_INT_CST_HIGH (arg1) == 0
- && (TREE_INT_CST_LOW (arg1)
- == ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1)
- && TREE_UNSIGNED (TREE_TYPE (arg1))
- /* signed_type does not work on pointer types. */
- && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
- switch (TREE_CODE (t))
- {
- case LE_EXPR:
- return fold (build (GE_EXPR, type,
- convert (signed_type (TREE_TYPE (arg0)),
- arg0),
- convert (signed_type (TREE_TYPE (arg1)),
- integer_zero_node)));
- case GT_EXPR:
- return fold (build (LT_EXPR, type,
- convert (signed_type (TREE_TYPE (arg0)),
- arg0),
- convert (signed_type (TREE_TYPE (arg1)),
- integer_zero_node)));
+ /* Weak declarations may link to NULL. */
+ if (VAR_OR_FUNCTION_DECL_P (base))
+ return !DECL_WEAK (base);
- default:
- break;
- }
+ /* Constants are never weak. */
+ if (CONSTANT_CLASS_P (base))
+ return true;
- else if (TREE_INT_CST_HIGH (arg1) == 0
- && (TREE_INT_CST_LOW (arg1)
- == ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1)
- && TREE_UNSIGNED (TREE_TYPE (arg1)))
- switch (TREE_CODE (t))
- {
- case GT_EXPR:
- return omit_one_operand (type,
- convert (type, integer_zero_node),
- arg0);
- case GE_EXPR:
- TREE_SET_CODE (t, EQ_EXPR);
- break;
-
- case LE_EXPR:
- return omit_one_operand (type,
- convert (type, integer_one_node),
- arg0);
- case LT_EXPR:
- TREE_SET_CODE (t, NE_EXPR);
- break;
-
- default:
- break;
- }
- }
+ return false;
}
- /* Change X >= CST to X > (CST - 1) and X < CST to X <= (CST - 1)
- if CST is positive. */
- if (TREE_CODE (arg1) == INTEGER_CST
- && TREE_CODE (arg0) != INTEGER_CST
- && tree_int_cst_sgn (arg1) > 0)
+ case COND_EXPR:
+ sub_strict_overflow_p = false;
+ if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
+ &sub_strict_overflow_p)
+ && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 2),
+ &sub_strict_overflow_p))
{
- switch (TREE_CODE (t))
- {
- case GE_EXPR:
- code = GT_EXPR;
- arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
- t = build (code, type, TREE_OPERAND (t, 0), arg1);
- break;
+ if (sub_strict_overflow_p)
+ *strict_overflow_p = true;
+ return true;
+ }
+ break;
- case LT_EXPR:
- code = LE_EXPR;
- arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
- t = build (code, type, TREE_OPERAND (t, 0), arg1);
- break;
+ default:
+ break;
+ }
+ return false;
+}
- default:
- break;
- }
- }
+/* Return true when T is an address and is known to be nonzero.
+ For floating point we further ensure that T is not denormal.
+ Similar logic is present in nonzero_address in rtlanal.h.
- /* An unsigned comparison against 0 can be simplified. */
- if (integer_zerop (arg1)
- && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
- || POINTER_TYPE_P (TREE_TYPE (arg1)))
- && TREE_UNSIGNED (TREE_TYPE (arg1)))
- {
- switch (TREE_CODE (t))
- {
- case GT_EXPR:
- code = NE_EXPR;
- TREE_SET_CODE (t, NE_EXPR);
- break;
- case LE_EXPR:
- code = EQ_EXPR;
- TREE_SET_CODE (t, EQ_EXPR);
- break;
- case GE_EXPR:
- return omit_one_operand (type,
- convert (type, integer_one_node),
- arg0);
- case LT_EXPR:
- return omit_one_operand (type,
- convert (type, integer_zero_node),
- arg0);
- default:
- break;
- }
- }
+ If the return value is based on the assumption that signed overflow
+ is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
+ change *STRICT_OVERFLOW_P. */
- /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
- a MINUS_EXPR of a constant, we can convert it into a comparison with
- a revised constant as long as no overflow occurs. */
- if ((code == EQ_EXPR || code == NE_EXPR)
- && TREE_CODE (arg1) == INTEGER_CST
- && (TREE_CODE (arg0) == PLUS_EXPR
- || TREE_CODE (arg0) == MINUS_EXPR)
- && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
- && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
- ? MINUS_EXPR : PLUS_EXPR,
- arg1, TREE_OPERAND (arg0, 1), 0))
- && ! TREE_CONSTANT_OVERFLOW (tem))
- return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
+bool
+tree_expr_nonzero_warnv_p (tree t, bool *strict_overflow_p)
+{
+ tree type = TREE_TYPE (t);
+ enum tree_code code;
+
+ /* Doing something useful for floating point would need more work. */
+ if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
+ return false;
+
+ code = TREE_CODE (t);
+ switch (TREE_CODE_CLASS (code))
+ {
+ case tcc_unary:
+ return tree_unary_nonzero_warnv_p (code, type, TREE_OPERAND (t, 0),
+ strict_overflow_p);
+ case tcc_binary:
+ case tcc_comparison:
+ return tree_binary_nonzero_warnv_p (code, type,
+ TREE_OPERAND (t, 0),
+ TREE_OPERAND (t, 1),
+ strict_overflow_p);
+ case tcc_constant:
+ case tcc_declaration:
+ case tcc_reference:
+ return tree_single_nonzero_warnv_p (t, strict_overflow_p);
+
+ default:
+ break;
+ }
+
+ switch (code)
+ {
+ case TRUTH_NOT_EXPR:
+ return tree_unary_nonzero_warnv_p (code, type, TREE_OPERAND (t, 0),
+ strict_overflow_p);
+
+ case TRUTH_AND_EXPR:
+ case TRUTH_OR_EXPR:
+ case TRUTH_XOR_EXPR:
+ return tree_binary_nonzero_warnv_p (code, type,
+ TREE_OPERAND (t, 0),
+ TREE_OPERAND (t, 1),
+ strict_overflow_p);
+
+ case COND_EXPR:
+ case CONSTRUCTOR:
+ case OBJ_TYPE_REF:
+ case ASSERT_EXPR:
+ case ADDR_EXPR:
+ case WITH_SIZE_EXPR:
+ case EXC_PTR_EXPR:
+ case SSA_NAME:
+ case FILTER_EXPR:
+ return tree_single_nonzero_warnv_p (t, strict_overflow_p);
+
+ case COMPOUND_EXPR:
+ case MODIFY_EXPR:
+ case BIND_EXPR:
+ return tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
+ strict_overflow_p);
+
+ case SAVE_EXPR:
+ return tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
+ strict_overflow_p);
+
+ case CALL_EXPR:
+ return alloca_call_p (t);
+
+ default:
+ break;
+ }
+ return false;
+}
+
+/* Return true when T is an address and is known to be nonzero.
+ Handle warnings about undefined signed overflow. */
+
+bool
+tree_expr_nonzero_p (tree t)
+{
+ bool ret, strict_overflow_p;
+
+ strict_overflow_p = false;
+ ret = tree_expr_nonzero_warnv_p (t, &strict_overflow_p);
+ if (strict_overflow_p)
+ fold_overflow_warning (("assuming signed overflow does not occur when "
+ "determining that expression is always "
+ "non-zero"),
+ WARN_STRICT_OVERFLOW_MISC);
+ return ret;
+}
+
+/* Given the components of a binary expression CODE, TYPE, OP0 and OP1,
+ attempt to fold the expression to a constant without modifying TYPE,
+ OP0 or OP1.
+
+ If the expression could be simplified to a constant, then return
+ the constant. If the expression would not be simplified to a
+ constant, then return NULL_TREE. */
+
+tree
+fold_binary_to_constant (enum tree_code code, tree type, tree op0, tree op1)
+{
+ tree tem = fold_binary (code, type, op0, op1);
+ return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
+}
- /* Similarly for a NEGATE_EXPR. */
- else if ((code == EQ_EXPR || code == NE_EXPR)
- && TREE_CODE (arg0) == NEGATE_EXPR
- && TREE_CODE (arg1) == INTEGER_CST
- && 0 != (tem = negate_expr (arg1))
- && TREE_CODE (tem) == INTEGER_CST
- && ! TREE_CONSTANT_OVERFLOW (tem))
- return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
+/* Given the components of a unary expression CODE, TYPE and OP0,
+ attempt to fold the expression to a constant without modifying
+ TYPE or OP0.
- /* If we have X - Y == 0, we can convert that to X == Y and similarly
- for !=. Don't do this for ordered comparisons due to overflow. */
- else if ((code == NE_EXPR || code == EQ_EXPR)
- && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
- return fold (build (code, type,
- TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1)));
+ If the expression could be simplified to a constant, then return
+ the constant. If the expression would not be simplified to a
+ constant, then return NULL_TREE. */
- /* If we are widening one operand of an integer comparison,
- see if the other operand is similarly being widened. Perhaps we
- can do the comparison in the narrower type. */
- else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
- && TREE_CODE (arg0) == NOP_EXPR
- && (tem = get_unwidened (arg0, NULL_TREE)) != arg0
- && (t1 = get_unwidened (arg1, TREE_TYPE (tem))) != 0
- && (TREE_TYPE (t1) == TREE_TYPE (tem)
- || (TREE_CODE (t1) == INTEGER_CST
- && int_fits_type_p (t1, TREE_TYPE (tem)))))
- return fold (build (code, type, tem, convert (TREE_TYPE (tem), t1)));
-
- /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
- constant, we can simplify it. */
- else if (TREE_CODE (arg1) == INTEGER_CST
- && (TREE_CODE (arg0) == MIN_EXPR
- || TREE_CODE (arg0) == MAX_EXPR)
- && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
- return optimize_minmax_comparison (t);
+tree
+fold_unary_to_constant (enum tree_code code, tree type, tree op0)
+{
+ tree tem = fold_unary (code, type, op0);
+ return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
+}
- /* If we are comparing an ABS_EXPR with a constant, we can
- convert all the cases into explicit comparisons, but they may
- well not be faster than doing the ABS and one comparison.
- But ABS (X) <= C is a range comparison, which becomes a subtraction
- and a comparison, and is probably faster. */
- else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
- && TREE_CODE (arg0) == ABS_EXPR
- && ! TREE_SIDE_EFFECTS (arg0)
- && (0 != (tem = negate_expr (arg1)))
- && TREE_CODE (tem) == INTEGER_CST
- && ! TREE_CONSTANT_OVERFLOW (tem))
- return fold (build (TRUTH_ANDIF_EXPR, type,
- build (GE_EXPR, type, TREE_OPERAND (arg0, 0), tem),
- build (LE_EXPR, type,
- TREE_OPERAND (arg0, 0), arg1)));
+/* If EXP represents referencing an element in a constant string
+ (either via pointer arithmetic or array indexing), return the
+ tree representing the value accessed, otherwise return NULL. */
- /* If this is an EQ or NE comparison with zero and ARG0 is
- (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
- two operations, but the latter can be done in one less insn
- on machines that have only two-operand insns or on which a
- constant cannot be the first operand. */
- if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
- && TREE_CODE (arg0) == BIT_AND_EXPR)
- {
- if (TREE_CODE (TREE_OPERAND (arg0, 0)) == LSHIFT_EXPR
- && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 0), 0)))
- return
- fold (build (code, type,
- build (BIT_AND_EXPR, TREE_TYPE (arg0),
- build (RSHIFT_EXPR,
- TREE_TYPE (TREE_OPERAND (arg0, 0)),
- TREE_OPERAND (arg0, 1),
- TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)),
- convert (TREE_TYPE (arg0),
- integer_one_node)),
- arg1));
- else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
- && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
- return
- fold (build (code, type,
- build (BIT_AND_EXPR, TREE_TYPE (arg0),
- build (RSHIFT_EXPR,
- TREE_TYPE (TREE_OPERAND (arg0, 1)),
- TREE_OPERAND (arg0, 0),
- TREE_OPERAND (TREE_OPERAND (arg0, 1), 1)),
- convert (TREE_TYPE (arg0),
- integer_one_node)),
- arg1));
- }
+tree
+fold_read_from_constant_string (tree exp)
+{
+ if ((TREE_CODE (exp) == INDIRECT_REF
+ || TREE_CODE (exp) == ARRAY_REF)
+ && TREE_CODE (TREE_TYPE (exp)) == INTEGER_TYPE)
+ {
+ tree exp1 = TREE_OPERAND (exp, 0);
+ tree index;
+ tree string;
- /* If this is an NE or EQ comparison of zero against the result of a
- signed MOD operation whose second operand is a power of 2, make
- the MOD operation unsigned since it is simpler and equivalent. */
- if ((code == NE_EXPR || code == EQ_EXPR)
- && integer_zerop (arg1)
- && ! TREE_UNSIGNED (TREE_TYPE (arg0))
- && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
- || TREE_CODE (arg0) == CEIL_MOD_EXPR
- || TREE_CODE (arg0) == FLOOR_MOD_EXPR
- || TREE_CODE (arg0) == ROUND_MOD_EXPR)
- && integer_pow2p (TREE_OPERAND (arg0, 1)))
+ if (TREE_CODE (exp) == INDIRECT_REF)
+ string = string_constant (exp1, &index);
+ else
{
- tree newtype = unsigned_type (TREE_TYPE (arg0));
- tree newmod = build (TREE_CODE (arg0), newtype,
- convert (newtype, TREE_OPERAND (arg0, 0)),
- convert (newtype, TREE_OPERAND (arg0, 1)));
+ tree low_bound = array_ref_low_bound (exp);
+ index = fold_convert (sizetype, TREE_OPERAND (exp, 1));
- return build (code, type, newmod, convert (newtype, arg1));
- }
+ /* Optimize the special-case of a zero lower bound.
- /* If this is an NE comparison of zero with an AND of one, remove the
- comparison since the AND will give the correct value. */
- if (code == NE_EXPR && integer_zerop (arg1)
- && TREE_CODE (arg0) == BIT_AND_EXPR
- && integer_onep (TREE_OPERAND (arg0, 1)))
- return convert (type, arg0);
+ We convert the low_bound to sizetype to avoid some problems
+ with constant folding. (E.g. suppose the lower bound is 1,
+ and its mode is QI. Without the conversion,l (ARRAY
+ +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
+ +INDEX), which becomes (ARRAY+255+INDEX). Oops!) */
+ if (! integer_zerop (low_bound))
+ index = size_diffop (index, fold_convert (sizetype, low_bound));
- /* If we have (A & C) == C where C is a power of 2, convert this into
- (A & C) != 0. Similarly for NE_EXPR. */
- if ((code == EQ_EXPR || code == NE_EXPR)
- && TREE_CODE (arg0) == BIT_AND_EXPR
- && integer_pow2p (TREE_OPERAND (arg0, 1))
- && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
- return build (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
- arg0, integer_zero_node);
+ string = exp1;
+ }
- /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
- and similarly for >= into !=. */
- if ((code == LT_EXPR || code == GE_EXPR)
- && TREE_UNSIGNED (TREE_TYPE (arg0))
- && TREE_CODE (arg1) == LSHIFT_EXPR
- && integer_onep (TREE_OPERAND (arg1, 0)))
- return build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
- build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
- TREE_OPERAND (arg1, 1)),
- convert (TREE_TYPE (arg0), integer_zero_node));
-
- else if ((code == LT_EXPR || code == GE_EXPR)
- && TREE_UNSIGNED (TREE_TYPE (arg0))
- && (TREE_CODE (arg1) == NOP_EXPR
- || TREE_CODE (arg1) == CONVERT_EXPR)
- && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
- && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
- return
- build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
- convert (TREE_TYPE (arg0),
- build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
- TREE_OPERAND (TREE_OPERAND (arg1, 0), 1))),
- convert (TREE_TYPE (arg0), integer_zero_node));
-
- /* Simplify comparison of something with itself. (For IEEE
- floating-point, we can only do some of these simplifications.) */
- if (operand_equal_p (arg0, arg1, 0))
- {
- switch (code)
- {
- case EQ_EXPR:
- case GE_EXPR:
- case LE_EXPR:
- if (! FLOAT_TYPE_P (TREE_TYPE (arg0)))
- return constant_boolean_node (1, type);
- code = EQ_EXPR;
- TREE_SET_CODE (t, code);
- break;
+ if (string
+ && TYPE_MODE (TREE_TYPE (exp)) == TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))
+ && TREE_CODE (string) == STRING_CST
+ && TREE_CODE (index) == INTEGER_CST
+ && compare_tree_int (index, TREE_STRING_LENGTH (string)) < 0
+ && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (string))))
+ == MODE_INT)
+ && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))) == 1))
+ return build_int_cst_type (TREE_TYPE (exp),
+ (TREE_STRING_POINTER (string)
+ [TREE_INT_CST_LOW (index)]));
+ }
+ return NULL;
+}
- case NE_EXPR:
- /* For NE, we can only do this simplification if integer. */
- if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
- break;
- /* ... fall through ... */
- case GT_EXPR:
- case LT_EXPR:
- return constant_boolean_node (0, type);
- default:
- abort ();
- }
- }
+/* Return the tree for neg (ARG0) when ARG0 is known to be either
+ an integer constant, real, or fixed-point constant.
- /* If we are comparing an expression that just has comparisons
- of two integer values, arithmetic expressions of those comparisons,
- and constants, we can simplify it. There are only three cases
- to check: the two values can either be equal, the first can be
- greater, or the second can be greater. Fold the expression for
- those three values. Since each value must be 0 or 1, we have
- eight possibilities, each of which corresponds to the constant 0
- or 1 or one of the six possible comparisons.
-
- This handles common cases like (a > b) == 0 but also handles
- expressions like ((x > y) - (y > x)) > 0, which supposedly
- occur in macroized code. */
-
- if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
- {
- tree cval1 = 0, cval2 = 0;
- int save_p = 0;
-
- if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
- /* Don't handle degenerate cases here; they should already
- have been handled anyway. */
- && cval1 != 0 && cval2 != 0
- && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
- && TREE_TYPE (cval1) == TREE_TYPE (cval2)
- && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
- && TYPE_MAX_VALUE (TREE_TYPE (cval1))
- && TYPE_MAX_VALUE (TREE_TYPE (cval2))
- && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
- TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
- {
- tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
- tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
-
- /* We can't just pass T to eval_subst in case cval1 or cval2
- was the same as ARG1. */
-
- tree high_result
- = fold (build (code, type,
- eval_subst (arg0, cval1, maxval, cval2, minval),
- arg1));
- tree equal_result
- = fold (build (code, type,
- eval_subst (arg0, cval1, maxval, cval2, maxval),
- arg1));
- tree low_result
- = fold (build (code, type,
- eval_subst (arg0, cval1, minval, cval2, maxval),
- arg1));
-
- /* All three of these results should be 0 or 1. Confirm they
- are. Then use those values to select the proper code
- to use. */
-
- if ((integer_zerop (high_result)
- || integer_onep (high_result))
- && (integer_zerop (equal_result)
- || integer_onep (equal_result))
- && (integer_zerop (low_result)
- || integer_onep (low_result)))
- {
- /* Make a 3-bit mask with the high-order bit being the
- value for `>', the next for '=', and the low for '<'. */
- switch ((integer_onep (high_result) * 4)
- + (integer_onep (equal_result) * 2)
- + integer_onep (low_result))
- {
- case 0:
- /* Always false. */
- return omit_one_operand (type, integer_zero_node, arg0);
- case 1:
- code = LT_EXPR;
- break;
- case 2:
- code = EQ_EXPR;
- break;
- case 3:
- code = LE_EXPR;
- break;
- case 4:
- code = GT_EXPR;
- break;
- case 5:
- code = NE_EXPR;
- break;
- case 6:
- code = GE_EXPR;
- break;
- case 7:
- /* Always true. */
- return omit_one_operand (type, integer_one_node, arg0);
- }
+ TYPE is the type of the result. */
- t = build (code, type, cval1, cval2);
- if (save_p)
- return save_expr (t);
- else
- return fold (t);
- }
- }
- }
+static tree
+fold_negate_const (tree arg0, tree type)
+{
+ tree t = NULL_TREE;
- /* If this is a comparison of a field, we may be able to simplify it. */
- if ((TREE_CODE (arg0) == COMPONENT_REF
- || TREE_CODE (arg0) == BIT_FIELD_REF)
- && (code == EQ_EXPR || code == NE_EXPR)
- /* Handle the constant case even without -O
- to make sure the warnings are given. */
- && (optimize || TREE_CODE (arg1) == INTEGER_CST))
- {
- t1 = optimize_bit_field_compare (code, type, arg0, arg1);
- return t1 ? t1 : t;
- }
-
- /* If this is a comparison of complex values and either or both sides
- are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
- comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
- This may prevent needless evaluations. */
- if ((code == EQ_EXPR || code == NE_EXPR)
- && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
- && (TREE_CODE (arg0) == COMPLEX_EXPR
- || TREE_CODE (arg1) == COMPLEX_EXPR
- || TREE_CODE (arg0) == COMPLEX_CST
- || TREE_CODE (arg1) == COMPLEX_CST))
- {
- tree subtype = TREE_TYPE (TREE_TYPE (arg0));
- tree real0, imag0, real1, imag1;
+ switch (TREE_CODE (arg0))
+ {
+ case INTEGER_CST:
+ {
+ unsigned HOST_WIDE_INT low;
+ HOST_WIDE_INT high;
+ int overflow = neg_double (TREE_INT_CST_LOW (arg0),
+ TREE_INT_CST_HIGH (arg0),
+ &low, &high);
+ t = force_fit_type_double (type, low, high, 1,
+ (overflow | TREE_OVERFLOW (arg0))
+ && !TYPE_UNSIGNED (type));
+ break;
+ }
- arg0 = save_expr (arg0);
- arg1 = save_expr (arg1);
- real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
- imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
- real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
- imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
+ case REAL_CST:
+ t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
+ break;
- return fold (build ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
- : TRUTH_ORIF_EXPR),
- type,
- fold (build (code, type, real0, real1)),
- fold (build (code, type, imag0, imag1))));
- }
+ case FIXED_CST:
+ {
+ FIXED_VALUE_TYPE f;
+ bool overflow_p = fixed_arithmetic (&f, NEGATE_EXPR,
+ &(TREE_FIXED_CST (arg0)), NULL,
+ TYPE_SATURATING (type));
+ t = build_fixed (type, f);
+ /* Propagate overflow flags. */
+ if (overflow_p | TREE_OVERFLOW (arg0))
+ {
+ TREE_OVERFLOW (t) = 1;
+ TREE_CONSTANT_OVERFLOW (t) = 1;
+ }
+ else if (TREE_CONSTANT_OVERFLOW (arg0))
+ TREE_CONSTANT_OVERFLOW (t) = 1;
+ break;
+ }
- /* Optimize comparisons of strlen vs zero to a compare of the
- first character of the string vs zero. To wit,
- strlen(ptr) == 0 => *ptr == 0
- strlen(ptr) != 0 => *ptr != 0
- Other cases should reduce to one of these two (or a constant)
- due to the return value of strlen being unsigned. */
- if ((code == EQ_EXPR || code == NE_EXPR)
- && integer_zerop (arg1)
- && TREE_CODE (arg0) == CALL_EXPR
- && TREE_CODE (TREE_OPERAND (arg0, 0)) == ADDR_EXPR)
- {
- tree fndecl = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
- tree arglist;
+ default:
+ gcc_unreachable ();
+ }
- if (TREE_CODE (fndecl) == FUNCTION_DECL
- && DECL_BUILT_IN (fndecl)
- && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD
- && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
- && (arglist = TREE_OPERAND (arg0, 1))
- && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist))) == POINTER_TYPE
- && ! TREE_CHAIN (arglist))
- return fold (build (code, type,
- build1 (INDIRECT_REF, char_type_node,
- TREE_VALUE(arglist)),
- integer_zero_node));
- }
+ return t;
+}
- /* From here on, the only cases we handle are when the result is
- known to be a constant.
+/* Return the tree for abs (ARG0) when ARG0 is known to be either
+ an integer constant or real constant.
- To compute GT, swap the arguments and do LT.
- To compute GE, do LT and invert the result.
- To compute LE, swap the arguments, do LT and invert the result.
- To compute NE, do EQ and invert the result.
+ TYPE is the type of the result. */
- Therefore, the code below must handle only EQ and LT. */
+tree
+fold_abs_const (tree arg0, tree type)
+{
+ tree t = NULL_TREE;
- if (code == LE_EXPR || code == GT_EXPR)
+ switch (TREE_CODE (arg0))
+ {
+ case INTEGER_CST:
+ /* If the value is unsigned, then the absolute value is
+ the same as the ordinary value. */
+ if (TYPE_UNSIGNED (type))
+ t = arg0;
+ /* Similarly, if the value is non-negative. */
+ else if (INT_CST_LT (integer_minus_one_node, arg0))
+ t = arg0;
+ /* If the value is negative, then the absolute value is
+ its negation. */
+ else
{
- tem = arg0, arg0 = arg1, arg1 = tem;
- code = swap_tree_comparison (code);
+ unsigned HOST_WIDE_INT low;
+ HOST_WIDE_INT high;
+ int overflow = neg_double (TREE_INT_CST_LOW (arg0),
+ TREE_INT_CST_HIGH (arg0),
+ &low, &high);
+ t = force_fit_type_double (type, low, high, -1,
+ overflow | TREE_OVERFLOW (arg0));
}
+ break;
- /* Note that it is safe to invert for real values here because we
- will check below in the one case that it matters. */
+ case REAL_CST:
+ if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
+ t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
+ else
+ t = arg0;
+ break;
- t1 = NULL_TREE;
- invert = 0;
- if (code == NE_EXPR || code == GE_EXPR)
- {
- invert = 1;
- code = invert_tree_comparison (code);
- }
+ default:
+ gcc_unreachable ();
+ }
- /* Compute a result for LT or EQ if args permit;
- otherwise return T. */
- if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
- {
- if (code == EQ_EXPR)
- t1 = build_int_2 (tree_int_cst_equal (arg0, arg1), 0);
- else
- t1 = build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0))
- ? INT_CST_LT_UNSIGNED (arg0, arg1)
- : INT_CST_LT (arg0, arg1)),
- 0);
- }
-
-#if 0 /* This is no longer useful, but breaks some real code. */
- /* Assume a nonexplicit constant cannot equal an explicit one,
- since such code would be undefined anyway.
- Exception: on sysvr4, using #pragma weak,
- a label can come out as 0. */
- else if (TREE_CODE (arg1) == INTEGER_CST
- && !integer_zerop (arg1)
- && TREE_CONSTANT (arg0)
- && TREE_CODE (arg0) == ADDR_EXPR
- && code == EQ_EXPR)
- t1 = build_int_2 (0, 0);
-#endif
- /* Two real constants can be compared explicitly. */
- else if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
- {
- /* If either operand is a NaN, the result is false with two
- exceptions: First, an NE_EXPR is true on NaNs, but that case
- is already handled correctly since we will be inverting the
- result for NE_EXPR. Second, if we had inverted a LE_EXPR
- or a GE_EXPR into a LT_EXPR, we must return true so that it
- will be inverted into false. */
-
- if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
- || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
- t1 = build_int_2 (invert && code == LT_EXPR, 0);
-
- else if (code == EQ_EXPR)
- t1 = build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0),
- TREE_REAL_CST (arg1)),
- 0);
- else
- t1 = build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0),
- TREE_REAL_CST (arg1)),
- 0);
- }
+ return t;
+}
- if (t1 == NULL_TREE)
- return t;
+/* Return the tree for not (ARG0) when ARG0 is known to be an integer
+ constant. TYPE is the type of the result. */
- if (invert)
- TREE_INT_CST_LOW (t1) ^= 1;
+static tree
+fold_not_const (tree arg0, tree type)
+{
+ tree t = NULL_TREE;
- TREE_TYPE (t1) = type;
- if (TREE_CODE (type) == BOOLEAN_TYPE)
- return truthvalue_conversion (t1);
- return t1;
+ gcc_assert (TREE_CODE (arg0) == INTEGER_CST);
- case COND_EXPR:
- /* Pedantic ANSI C says that a conditional expression is never an lvalue,
- so all simple results must be passed through pedantic_non_lvalue. */
- if (TREE_CODE (arg0) == INTEGER_CST)
- return pedantic_non_lvalue
- (TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1)));
- else if (operand_equal_p (arg1, TREE_OPERAND (expr, 2), 0))
- return pedantic_omit_one_operand (type, arg1, arg0);
+ t = force_fit_type_double (type, ~TREE_INT_CST_LOW (arg0),
+ ~TREE_INT_CST_HIGH (arg0), 0,
+ TREE_OVERFLOW (arg0));
- /* If the second operand is zero, invert the comparison and swap
- the second and third operands. Likewise if the second operand
- is constant and the third is not or if the third operand is
- equivalent to the first operand of the comparison. */
+ return t;
+}
- if (integer_zerop (arg1)
- || (TREE_CONSTANT (arg1) && ! TREE_CONSTANT (TREE_OPERAND (t, 2)))
- || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
- && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
- TREE_OPERAND (t, 2),
- TREE_OPERAND (arg0, 1))))
- {
- /* See if this can be inverted. If it can't, possibly because
- it was a floating-point inequality comparison, don't do
- anything. */
- tem = invert_truthvalue (arg0);
+/* Given CODE, a relational operator, the target type, TYPE and two
+ constant operands OP0 and OP1, return the result of the
+ relational operation. If the result is not a compile time
+ constant, then return NULL_TREE. */
+
+static tree
+fold_relational_const (enum tree_code code, tree type, tree op0, tree op1)
+{
+ int result, invert;
+
+ /* From here on, the only cases we handle are when the result is
+ known to be a constant. */
+
+ if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
+ {
+ const REAL_VALUE_TYPE *c0 = TREE_REAL_CST_PTR (op0);
+ const REAL_VALUE_TYPE *c1 = TREE_REAL_CST_PTR (op1);
- if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
+ /* Handle the cases where either operand is a NaN. */
+ if (real_isnan (c0) || real_isnan (c1))
+ {
+ switch (code)
{
- t = build (code, type, tem,
- TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
- arg0 = tem;
- /* arg1 should be the first argument of the new T. */
- arg1 = TREE_OPERAND (t, 1);
- STRIP_NOPS (arg1);
+ case EQ_EXPR:
+ case ORDERED_EXPR:
+ result = 0;
+ break;
+
+ case NE_EXPR:
+ case UNORDERED_EXPR:
+ case UNLT_EXPR:
+ case UNLE_EXPR:
+ case UNGT_EXPR:
+ case UNGE_EXPR:
+ case UNEQ_EXPR:
+ result = 1;
+ break;
+
+ case LT_EXPR:
+ case LE_EXPR:
+ case GT_EXPR:
+ case GE_EXPR:
+ case LTGT_EXPR:
+ if (flag_trapping_math)
+ return NULL_TREE;
+ result = 0;
+ break;
+
+ default:
+ gcc_unreachable ();
}
+
+ return constant_boolean_node (result, type);
}
- /* If we have A op B ? A : C, we may be able to convert this to a
- simpler expression, depending on the operation and the values
- of B and C. IEEE floating point prevents this though,
- because A or B might be -0.0 or a NaN. */
+ return constant_boolean_node (real_compare (code, c0, c1), type);
+ }
- if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
- && (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
- || ! FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0)))
- || flag_unsafe_math_optimizations)
- && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
- arg1, TREE_OPERAND (arg0, 1)))
- {
- tree arg2 = TREE_OPERAND (t, 2);
- enum tree_code comp_code = TREE_CODE (arg0);
+ if (TREE_CODE (op0) == FIXED_CST && TREE_CODE (op1) == FIXED_CST)
+ {
+ const FIXED_VALUE_TYPE *c0 = TREE_FIXED_CST_PTR (op0);
+ const FIXED_VALUE_TYPE *c1 = TREE_FIXED_CST_PTR (op1);
+ return constant_boolean_node (fixed_compare (code, c0, c1), type);
+ }
+
+ /* Handle equality/inequality of complex constants. */
+ if (TREE_CODE (op0) == COMPLEX_CST && TREE_CODE (op1) == COMPLEX_CST)
+ {
+ tree rcond = fold_relational_const (code, type,
+ TREE_REALPART (op0),
+ TREE_REALPART (op1));
+ tree icond = fold_relational_const (code, type,
+ TREE_IMAGPART (op0),
+ TREE_IMAGPART (op1));
+ if (code == EQ_EXPR)
+ return fold_build2 (TRUTH_ANDIF_EXPR, type, rcond, icond);
+ else if (code == NE_EXPR)
+ return fold_build2 (TRUTH_ORIF_EXPR, type, rcond, icond);
+ else
+ return NULL_TREE;
+ }
- STRIP_NOPS (arg2);
+ /* From here on we only handle LT, LE, GT, GE, EQ and NE.
- /* If we have A op 0 ? A : -A, this is A, -A, abs (A), or -abs (A),
- depending on the comparison operation. */
- if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 1)))
- ? real_zerop (TREE_OPERAND (arg0, 1))
- : integer_zerop (TREE_OPERAND (arg0, 1)))
- && TREE_CODE (arg2) == NEGATE_EXPR
- && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
- switch (comp_code)
- {
- case EQ_EXPR:
- return
- pedantic_non_lvalue
- (convert (type,
- negate_expr
- (convert (TREE_TYPE (TREE_OPERAND (t, 1)),
- arg1))));
-
- case NE_EXPR:
- return pedantic_non_lvalue (convert (type, arg1));
- case GE_EXPR:
- case GT_EXPR:
- if (TREE_UNSIGNED (TREE_TYPE (arg1)))
- arg1 = convert (signed_type (TREE_TYPE (arg1)), arg1);
- return pedantic_non_lvalue
- (convert (type, fold (build1 (ABS_EXPR,
- TREE_TYPE (arg1), arg1))));
- case LE_EXPR:
- case LT_EXPR:
- if (TREE_UNSIGNED (TREE_TYPE (arg1)))
- arg1 = convert (signed_type (TREE_TYPE (arg1)), arg1);
- return pedantic_non_lvalue
- (negate_expr (convert (type,
- fold (build1 (ABS_EXPR,
- TREE_TYPE (arg1),
- arg1)))));
- default:
- abort ();
- }
+ To compute GT, swap the arguments and do LT.
+ To compute GE, do LT and invert the result.
+ To compute LE, swap the arguments, do LT and invert the result.
+ To compute NE, do EQ and invert the result.
- /* If this is A != 0 ? A : 0, this is simply A. For ==, it is
- always zero. */
+ Therefore, the code below must handle only EQ and LT. */
- if (integer_zerop (TREE_OPERAND (arg0, 1)) && integer_zerop (arg2))
- {
- if (comp_code == NE_EXPR)
- return pedantic_non_lvalue (convert (type, arg1));
- else if (comp_code == EQ_EXPR)
- return pedantic_non_lvalue (convert (type, integer_zero_node));
- }
+ if (code == LE_EXPR || code == GT_EXPR)
+ {
+ tree tem = op0;
+ op0 = op1;
+ op1 = tem;
+ code = swap_tree_comparison (code);
+ }
- /* If this is A op B ? A : B, this is either A, B, min (A, B),
- or max (A, B), depending on the operation. */
+ /* Note that it is safe to invert for real values here because we
+ have already handled the one case that it matters. */
- if (operand_equal_for_comparison_p (TREE_OPERAND (arg0, 1),
- arg2, TREE_OPERAND (arg0, 0)))
- {
- tree comp_op0 = TREE_OPERAND (arg0, 0);
- tree comp_op1 = TREE_OPERAND (arg0, 1);
- tree comp_type = TREE_TYPE (comp_op0);
+ invert = 0;
+ if (code == NE_EXPR || code == GE_EXPR)
+ {
+ invert = 1;
+ code = invert_tree_comparison (code, false);
+ }
- /* Avoid adding NOP_EXPRs in case this is an lvalue. */
- if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
- comp_type = type;
+ /* Compute a result for LT or EQ if args permit;
+ Otherwise return T. */
+ if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
+ {
+ if (code == EQ_EXPR)
+ result = tree_int_cst_equal (op0, op1);
+ else if (TYPE_UNSIGNED (TREE_TYPE (op0)))
+ result = INT_CST_LT_UNSIGNED (op0, op1);
+ else
+ result = INT_CST_LT (op0, op1);
+ }
+ else
+ return NULL_TREE;
- switch (comp_code)
- {
- case EQ_EXPR:
- return pedantic_non_lvalue (convert (type, arg2));
- case NE_EXPR:
- return pedantic_non_lvalue (convert (type, arg1));
- case LE_EXPR:
- case LT_EXPR:
- /* In C++ a ?: expression can be an lvalue, so put the
- operand which will be used if they are equal first
- so that we can convert this back to the
- corresponding COND_EXPR. */
- return pedantic_non_lvalue
- (convert (type, fold (build (MIN_EXPR, comp_type,
- (comp_code == LE_EXPR
- ? comp_op0 : comp_op1),
- (comp_code == LE_EXPR
- ? comp_op1 : comp_op0)))));
- break;
- case GE_EXPR:
- case GT_EXPR:
- return pedantic_non_lvalue
- (convert (type, fold (build (MAX_EXPR, comp_type,
- (comp_code == GE_EXPR
- ? comp_op0 : comp_op1),
- (comp_code == GE_EXPR
- ? comp_op1 : comp_op0)))));
- break;
- default:
- abort ();
- }
- }
+ if (invert)
+ result ^= 1;
+ return constant_boolean_node (result, type);
+}
- /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
- we might still be able to simplify this. For example,
- if C1 is one less or one more than C2, this might have started
- out as a MIN or MAX and been transformed by this function.
- Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
+/* If necessary, return a CLEANUP_POINT_EXPR for EXPR with the
+ indicated TYPE. If no CLEANUP_POINT_EXPR is necessary, return EXPR
+ itself. */
- if (INTEGRAL_TYPE_P (type)
- && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
- && TREE_CODE (arg2) == INTEGER_CST)
- switch (comp_code)
- {
- case EQ_EXPR:
- /* We can replace A with C1 in this case. */
- arg1 = convert (type, TREE_OPERAND (arg0, 1));
- t = build (code, type, TREE_OPERAND (t, 0), arg1,
- TREE_OPERAND (t, 2));
- break;
+tree
+fold_build_cleanup_point_expr (tree type, tree expr)
+{
+ /* If the expression does not have side effects then we don't have to wrap
+ it with a cleanup point expression. */
+ if (!TREE_SIDE_EFFECTS (expr))
+ return expr;
+
+ /* If the expression is a return, check to see if the expression inside the
+ return has no side effects or the right hand side of the modify expression
+ inside the return. If either don't have side effects set we don't need to
+ wrap the expression in a cleanup point expression. Note we don't check the
+ left hand side of the modify because it should always be a return decl. */
+ if (TREE_CODE (expr) == RETURN_EXPR)
+ {
+ tree op = TREE_OPERAND (expr, 0);
+ if (!op || !TREE_SIDE_EFFECTS (op))
+ return expr;
+ op = TREE_OPERAND (op, 1);
+ if (!TREE_SIDE_EFFECTS (op))
+ return expr;
+ }
+
+ return build1 (CLEANUP_POINT_EXPR, type, expr);
+}
- case LT_EXPR:
- /* If C1 is C2 + 1, this is min(A, C2). */
- if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
- && operand_equal_p (TREE_OPERAND (arg0, 1),
- const_binop (PLUS_EXPR, arg2,
- integer_one_node, 0), 1))
- return pedantic_non_lvalue
- (fold (build (MIN_EXPR, type, arg1, arg2)));
- break;
+/* Given a pointer value OP0 and a type TYPE, return a simplified version
+ of an indirection through OP0, or NULL_TREE if no simplification is
+ possible. */
- case LE_EXPR:
- /* If C1 is C2 - 1, this is min(A, C2). */
- if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
- && operand_equal_p (TREE_OPERAND (arg0, 1),
- const_binop (MINUS_EXPR, arg2,
- integer_one_node, 0), 1))
- return pedantic_non_lvalue
- (fold (build (MIN_EXPR, type, arg1, arg2)));
- break;
+tree
+fold_indirect_ref_1 (tree type, tree op0)
+{
+ tree sub = op0;
+ tree subtype;
- case GT_EXPR:
- /* If C1 is C2 - 1, this is max(A, C2). */
- if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
- && operand_equal_p (TREE_OPERAND (arg0, 1),
- const_binop (MINUS_EXPR, arg2,
- integer_one_node, 0), 1))
- return pedantic_non_lvalue
- (fold (build (MAX_EXPR, type, arg1, arg2)));
- break;
+ STRIP_NOPS (sub);
+ subtype = TREE_TYPE (sub);
+ if (!POINTER_TYPE_P (subtype))
+ return NULL_TREE;
- case GE_EXPR:
- /* If C1 is C2 + 1, this is max(A, C2). */
- if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
- && operand_equal_p (TREE_OPERAND (arg0, 1),
- const_binop (PLUS_EXPR, arg2,
- integer_one_node, 0), 1))
- return pedantic_non_lvalue
- (fold (build (MAX_EXPR, type, arg1, arg2)));
- break;
- case NE_EXPR:
- break;
- default:
- abort ();
- }
+ if (TREE_CODE (sub) == ADDR_EXPR)
+ {
+ tree op = TREE_OPERAND (sub, 0);
+ tree optype = TREE_TYPE (op);
+ /* *&CONST_DECL -> to the value of the const decl. */
+ if (TREE_CODE (op) == CONST_DECL)
+ return DECL_INITIAL (op);
+ /* *&p => p; make sure to handle *&"str"[cst] here. */
+ if (type == optype)
+ {
+ tree fop = fold_read_from_constant_string (op);
+ if (fop)
+ return fop;
+ else
+ return op;
+ }
+ /* *(foo *)&fooarray => fooarray[0] */
+ else if (TREE_CODE (optype) == ARRAY_TYPE
+ && type == TREE_TYPE (optype))
+ {
+ tree type_domain = TYPE_DOMAIN (optype);
+ tree min_val = size_zero_node;
+ if (type_domain && TYPE_MIN_VALUE (type_domain))
+ min_val = TYPE_MIN_VALUE (type_domain);
+ return build4 (ARRAY_REF, type, op, min_val, NULL_TREE, NULL_TREE);
+ }
+ /* *(foo *)&complexfoo => __real__ complexfoo */
+ else if (TREE_CODE (optype) == COMPLEX_TYPE
+ && type == TREE_TYPE (optype))
+ return fold_build1 (REALPART_EXPR, type, op);
+ /* *(foo *)&vectorfoo => BIT_FIELD_REF<vectorfoo,...> */
+ else if (TREE_CODE (optype) == VECTOR_TYPE
+ && type == TREE_TYPE (optype))
+ {
+ tree part_width = TYPE_SIZE (type);
+ tree index = bitsize_int (0);
+ return fold_build3 (BIT_FIELD_REF, type, op, part_width, index);
+ }
+ }
+
+ /* ((foo*)&vectorfoo)[1] => BIT_FIELD_REF<vectorfoo,...> */
+ if (TREE_CODE (sub) == POINTER_PLUS_EXPR
+ && TREE_CODE (TREE_OPERAND (sub, 1)) == INTEGER_CST)
+ {
+ tree op00 = TREE_OPERAND (sub, 0);
+ tree op01 = TREE_OPERAND (sub, 1);
+ tree op00type;
+
+ STRIP_NOPS (op00);
+ op00type = TREE_TYPE (op00);
+ if (TREE_CODE (op00) == ADDR_EXPR
+ && TREE_CODE (TREE_TYPE (op00type)) == VECTOR_TYPE
+ && type == TREE_TYPE (TREE_TYPE (op00type)))
+ {
+ HOST_WIDE_INT offset = tree_low_cst (op01, 0);
+ tree part_width = TYPE_SIZE (type);
+ unsigned HOST_WIDE_INT part_widthi = tree_low_cst (part_width, 0)/BITS_PER_UNIT;
+ unsigned HOST_WIDE_INT indexi = offset * BITS_PER_UNIT;
+ tree index = bitsize_int (indexi);
+
+ if (offset/part_widthi <= TYPE_VECTOR_SUBPARTS (TREE_TYPE (op00type)))
+ return fold_build3 (BIT_FIELD_REF, type, TREE_OPERAND (op00, 0),
+ part_width, index);
+
}
+ }
- /* If the second operand is simpler than the third, swap them
- since that produces better jump optimization results. */
- if ((TREE_CONSTANT (arg1) || DECL_P (arg1)
- || TREE_CODE (arg1) == SAVE_EXPR)
- && ! (TREE_CONSTANT (TREE_OPERAND (t, 2))
- || DECL_P (TREE_OPERAND (t, 2))
- || TREE_CODE (TREE_OPERAND (t, 2)) == SAVE_EXPR))
- {
- /* See if this can be inverted. If it can't, possibly because
- it was a floating-point inequality comparison, don't do
- anything. */
- tem = invert_truthvalue (arg0);
- if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
- {
- t = build (code, type, tem,
- TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
- arg0 = tem;
- /* arg1 should be the first argument of the new T. */
- arg1 = TREE_OPERAND (t, 1);
- STRIP_NOPS (arg1);
- }
+ /* ((foo*)&complexfoo)[1] => __imag__ complexfoo */
+ if (TREE_CODE (sub) == POINTER_PLUS_EXPR
+ && TREE_CODE (TREE_OPERAND (sub, 1)) == INTEGER_CST)
+ {
+ tree op00 = TREE_OPERAND (sub, 0);
+ tree op01 = TREE_OPERAND (sub, 1);
+ tree op00type;
+
+ STRIP_NOPS (op00);
+ op00type = TREE_TYPE (op00);
+ if (TREE_CODE (op00) == ADDR_EXPR
+ && TREE_CODE (TREE_TYPE (op00type)) == COMPLEX_TYPE
+ && type == TREE_TYPE (TREE_TYPE (op00type)))
+ {
+ tree size = TYPE_SIZE_UNIT (type);
+ if (tree_int_cst_equal (size, op01))
+ return fold_build1 (IMAGPART_EXPR, type, TREE_OPERAND (op00, 0));
}
+ }
+
+ /* *(foo *)fooarrptr => (*fooarrptr)[0] */
+ if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE
+ && type == TREE_TYPE (TREE_TYPE (subtype)))
+ {
+ tree type_domain;
+ tree min_val = size_zero_node;
+ sub = build_fold_indirect_ref (sub);
+ type_domain = TYPE_DOMAIN (TREE_TYPE (sub));
+ if (type_domain && TYPE_MIN_VALUE (type_domain))
+ min_val = TYPE_MIN_VALUE (type_domain);
+ return build4 (ARRAY_REF, type, sub, min_val, NULL_TREE, NULL_TREE);
+ }
- /* Convert A ? 1 : 0 to simply A. */
- if (integer_onep (TREE_OPERAND (t, 1))
- && integer_zerop (TREE_OPERAND (t, 2))
- /* If we try to convert TREE_OPERAND (t, 0) to our type, the
- call to fold will try to move the conversion inside
- a COND, which will recurse. In that case, the COND_EXPR
- is probably the best choice, so leave it alone. */
- && type == TREE_TYPE (arg0))
- return pedantic_non_lvalue (arg0);
+ return NULL_TREE;
+}
- /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
- operation is simply A & 2. */
+/* Builds an expression for an indirection through T, simplifying some
+ cases. */
- if (integer_zerop (TREE_OPERAND (t, 2))
- && TREE_CODE (arg0) == NE_EXPR
- && integer_zerop (TREE_OPERAND (arg0, 1))
- && integer_pow2p (arg1)
- && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
- && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
- arg1, 1))
- return pedantic_non_lvalue (convert (type, TREE_OPERAND (arg0, 0)));
+tree
+build_fold_indirect_ref (tree t)
+{
+ tree type = TREE_TYPE (TREE_TYPE (t));
+ tree sub = fold_indirect_ref_1 (type, t);
- return t;
+ if (sub)
+ return sub;
+ else
+ return build1 (INDIRECT_REF, type, t);
+}
- case COMPOUND_EXPR:
- /* When pedantic, a compound expression can be neither an lvalue
- nor an integer constant expression. */
- if (TREE_SIDE_EFFECTS (arg0) || pedantic)
- return t;
- /* Don't let (0, 0) be null pointer constant. */
- if (integer_zerop (arg1))
- return build1 (NOP_EXPR, type, arg1);
- return convert (type, arg1);
+/* Given an INDIRECT_REF T, return either T or a simplified version. */
- case COMPLEX_EXPR:
- if (wins)
- return build_complex (type, arg0, arg1);
- return t;
+tree
+fold_indirect_ref (tree t)
+{
+ tree sub = fold_indirect_ref_1 (TREE_TYPE (t), TREE_OPERAND (t, 0));
- case REALPART_EXPR:
- if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
- return t;
- else if (TREE_CODE (arg0) == COMPLEX_EXPR)
- return omit_one_operand (type, TREE_OPERAND (arg0, 0),
- TREE_OPERAND (arg0, 1));
- else if (TREE_CODE (arg0) == COMPLEX_CST)
- return TREE_REALPART (arg0);
- else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
- return fold (build (TREE_CODE (arg0), type,
- fold (build1 (REALPART_EXPR, type,
- TREE_OPERAND (arg0, 0))),
- fold (build1 (REALPART_EXPR,
- type, TREE_OPERAND (arg0, 1)))));
- return t;
+ if (sub)
+ return sub;
+ else
+ return t;
+}
- case IMAGPART_EXPR:
- if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
- return convert (type, integer_zero_node);
- else if (TREE_CODE (arg0) == COMPLEX_EXPR)
- return omit_one_operand (type, TREE_OPERAND (arg0, 1),
- TREE_OPERAND (arg0, 0));
- else if (TREE_CODE (arg0) == COMPLEX_CST)
- return TREE_IMAGPART (arg0);
- else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
- return fold (build (TREE_CODE (arg0), type,
- fold (build1 (IMAGPART_EXPR, type,
- TREE_OPERAND (arg0, 0))),
- fold (build1 (IMAGPART_EXPR, type,
- TREE_OPERAND (arg0, 1)))));
- return t;
+/* Strip non-trapping, non-side-effecting tree nodes from an expression
+ whose result is ignored. The type of the returned tree need not be
+ the same as the original expression. */
- /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
- appropriate. */
- case CLEANUP_POINT_EXPR:
- if (! has_cleanups (arg0))
- return TREE_OPERAND (t, 0);
+tree
+fold_ignored_result (tree t)
+{
+ if (!TREE_SIDE_EFFECTS (t))
+ return integer_zero_node;
+ for (;;)
+ switch (TREE_CODE_CLASS (TREE_CODE (t)))
{
- enum tree_code code0 = TREE_CODE (arg0);
- int kind0 = TREE_CODE_CLASS (code0);
- tree arg00 = TREE_OPERAND (arg0, 0);
- tree arg01;
-
- if (kind0 == '1' || code0 == TRUTH_NOT_EXPR)
- return fold (build1 (code0, type,
- fold (build1 (CLEANUP_POINT_EXPR,
- TREE_TYPE (arg00), arg00))));
-
- if (kind0 == '<' || kind0 == '2'
- || code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR
- || code0 == TRUTH_AND_EXPR || code0 == TRUTH_OR_EXPR
- || code0 == TRUTH_XOR_EXPR)
+ case tcc_unary:
+ t = TREE_OPERAND (t, 0);
+ break;
+
+ case tcc_binary:
+ case tcc_comparison:
+ if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
+ t = TREE_OPERAND (t, 0);
+ else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0)))
+ t = TREE_OPERAND (t, 1);
+ else
+ return t;
+ break;
+
+ case tcc_expression:
+ switch (TREE_CODE (t))
{
- arg01 = TREE_OPERAND (arg0, 1);
-
- if (TREE_CONSTANT (arg00)
- || ((code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR)
- && ! has_cleanups (arg00)))
- return fold (build (code0, type, arg00,
- fold (build1 (CLEANUP_POINT_EXPR,
- TREE_TYPE (arg01), arg01))));
-
- if (TREE_CONSTANT (arg01))
- return fold (build (code0, type,
- fold (build1 (CLEANUP_POINT_EXPR,
- TREE_TYPE (arg00), arg00)),
- arg01));
+ case COMPOUND_EXPR:
+ if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
+ return t;
+ t = TREE_OPERAND (t, 0);
+ break;
+
+ case COND_EXPR:
+ if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1))
+ || TREE_SIDE_EFFECTS (TREE_OPERAND (t, 2)))
+ return t;
+ t = TREE_OPERAND (t, 0);
+ break;
+
+ default:
+ return t;
}
+ break;
+ default:
return t;
}
+}
- case CALL_EXPR:
- /* Check for a built-in function. */
- if (TREE_CODE (TREE_OPERAND (expr, 0)) == ADDR_EXPR
- && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (expr, 0), 0))
- == FUNCTION_DECL)
- && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (expr, 0), 0)))
- {
- tree tmp = fold_builtin (expr);
- if (tmp)
- return tmp;
- }
- return t;
+/* Return the value of VALUE, rounded up to a multiple of DIVISOR.
+ This can only be applied to objects of a sizetype. */
- default:
- return t;
- } /* switch (code) */
-}
+tree
+round_up (tree value, int divisor)
+{
+ tree div = NULL_TREE;
-/* Determine if first argument is a multiple of second argument. Return 0 if
- it is not, or we cannot easily determined it to be.
+ gcc_assert (divisor > 0);
+ if (divisor == 1)
+ return value;
- An example of the sort of thing we care about (at this point; this routine
- could surely be made more general, and expanded to do what the *_DIV_EXPR's
- fold cases do now) is discovering that
+ /* See if VALUE is already a multiple of DIVISOR. If so, we don't
+ have to do anything. Only do this when we are not given a const,
+ because in that case, this check is more expensive than just
+ doing it. */
+ if (TREE_CODE (value) != INTEGER_CST)
+ {
+ div = build_int_cst (TREE_TYPE (value), divisor);
- SAVE_EXPR (I) * SAVE_EXPR (J * 8)
+ if (multiple_of_p (TREE_TYPE (value), value, div))
+ return value;
+ }
- is a multiple of
+ /* If divisor is a power of two, simplify this to bit manipulation. */
+ if (divisor == (divisor & -divisor))
+ {
+ if (TREE_CODE (value) == INTEGER_CST)
+ {
+ unsigned HOST_WIDE_INT low = TREE_INT_CST_LOW (value);
+ unsigned HOST_WIDE_INT high;
+ bool overflow_p;
+
+ if ((low & (divisor - 1)) == 0)
+ return value;
+
+ overflow_p = TREE_OVERFLOW (value);
+ high = TREE_INT_CST_HIGH (value);
+ low &= ~(divisor - 1);
+ low += divisor;
+ if (low == 0)
+ {
+ high++;
+ if (high == 0)
+ overflow_p = true;
+ }
- SAVE_EXPR (J * 8)
+ return force_fit_type_double (TREE_TYPE (value), low, high,
+ -1, overflow_p);
+ }
+ else
+ {
+ tree t;
- when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
+ t = build_int_cst (TREE_TYPE (value), divisor - 1);
+ value = size_binop (PLUS_EXPR, value, t);
+ t = build_int_cst (TREE_TYPE (value), -divisor);
+ value = size_binop (BIT_AND_EXPR, value, t);
+ }
+ }
+ else
+ {
+ if (!div)
+ div = build_int_cst (TREE_TYPE (value), divisor);
+ value = size_binop (CEIL_DIV_EXPR, value, div);
+ value = size_binop (MULT_EXPR, value, div);
+ }
- This code also handles discovering that
+ return value;
+}
- SAVE_EXPR (I) * SAVE_EXPR (J * 8)
+/* Likewise, but round down. */
- is a multiple of 8 so we don't have to worry about dealing with a
- possible remainder.
+tree
+round_down (tree value, int divisor)
+{
+ tree div = NULL_TREE;
- Note that we *look* inside a SAVE_EXPR only to determine how it was
- calculated; it is not safe for fold to do much of anything else with the
- internals of a SAVE_EXPR, since it cannot know when it will be evaluated
- at run time. For example, the latter example above *cannot* be implemented
- as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
- evaluation time of the original SAVE_EXPR is not necessarily the same at
- the time the new expression is evaluated. The only optimization of this
- sort that would be valid is changing
+ gcc_assert (divisor > 0);
+ if (divisor == 1)
+ return value;
- SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
+ /* See if VALUE is already a multiple of DIVISOR. If so, we don't
+ have to do anything. Only do this when we are not given a const,
+ because in that case, this check is more expensive than just
+ doing it. */
+ if (TREE_CODE (value) != INTEGER_CST)
+ {
+ div = build_int_cst (TREE_TYPE (value), divisor);
- divided by 8 to
+ if (multiple_of_p (TREE_TYPE (value), value, div))
+ return value;
+ }
- SAVE_EXPR (I) * SAVE_EXPR (J)
+ /* If divisor is a power of two, simplify this to bit manipulation. */
+ if (divisor == (divisor & -divisor))
+ {
+ tree t;
- (where the same SAVE_EXPR (J) is used in the original and the
- transformed version). */
+ t = build_int_cst (TREE_TYPE (value), -divisor);
+ value = size_binop (BIT_AND_EXPR, value, t);
+ }
+ else
+ {
+ if (!div)
+ div = build_int_cst (TREE_TYPE (value), divisor);
+ value = size_binop (FLOOR_DIV_EXPR, value, div);
+ value = size_binop (MULT_EXPR, value, div);
+ }
-static int
-multiple_of_p (type, top, bottom)
- tree type;
- tree top;
- tree bottom;
-{
- if (operand_equal_p (top, bottom, 0))
- return 1;
+ return value;
+}
- if (TREE_CODE (type) != INTEGER_TYPE)
- return 0;
+/* Returns the pointer to the base of the object addressed by EXP and
+ extracts the information about the offset of the access, storing it
+ to PBITPOS and POFFSET. */
- switch (TREE_CODE (top))
+static tree
+split_address_to_core_and_offset (tree exp,
+ HOST_WIDE_INT *pbitpos, tree *poffset)
+{
+ tree core;
+ enum machine_mode mode;
+ int unsignedp, volatilep;
+ HOST_WIDE_INT bitsize;
+
+ if (TREE_CODE (exp) == ADDR_EXPR)
{
- case MULT_EXPR:
- return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
- || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
+ core = get_inner_reference (TREE_OPERAND (exp, 0), &bitsize, pbitpos,
+ poffset, &mode, &unsignedp, &volatilep,
+ false);
+ core = fold_addr_expr (core);
+ }
+ else
+ {
+ core = exp;
+ *pbitpos = 0;
+ *poffset = NULL_TREE;
+ }
- case PLUS_EXPR:
- case MINUS_EXPR:
- return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
- && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
+ return core;
+}
- case LSHIFT_EXPR:
- if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
- {
- tree op1, t1;
+/* Returns true if addresses of E1 and E2 differ by a constant, false
+ otherwise. If they do, E1 - E2 is stored in *DIFF. */
- op1 = TREE_OPERAND (top, 1);
- /* const_binop may not detect overflow correctly,
- so check for it explicitly here. */
- if (TYPE_PRECISION (TREE_TYPE (size_one_node))
- > TREE_INT_CST_LOW (op1)
- && TREE_INT_CST_HIGH (op1) == 0
- && 0 != (t1 = convert (type,
- const_binop (LSHIFT_EXPR, size_one_node,
- op1, 0)))
- && ! TREE_OVERFLOW (t1))
- return multiple_of_p (type, t1, bottom);
- }
- return 0;
+bool
+ptr_difference_const (tree e1, tree e2, HOST_WIDE_INT *diff)
+{
+ tree core1, core2;
+ HOST_WIDE_INT bitpos1, bitpos2;
+ tree toffset1, toffset2, tdiff, type;
- case NOP_EXPR:
- /* Can't handle conversions from non-integral or wider integral type. */
- if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
- || (TYPE_PRECISION (type)
- < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
- return 0;
+ core1 = split_address_to_core_and_offset (e1, &bitpos1, &toffset1);
+ core2 = split_address_to_core_and_offset (e2, &bitpos2, &toffset2);
- /* .. fall through ... */
+ if (bitpos1 % BITS_PER_UNIT != 0
+ || bitpos2 % BITS_PER_UNIT != 0
+ || !operand_equal_p (core1, core2, 0))
+ return false;
- case SAVE_EXPR:
- return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
+ if (toffset1 && toffset2)
+ {
+ type = TREE_TYPE (toffset1);
+ if (type != TREE_TYPE (toffset2))
+ toffset2 = fold_convert (type, toffset2);
- case INTEGER_CST:
- if (TREE_CODE (bottom) != INTEGER_CST
- || (TREE_UNSIGNED (type)
- && (tree_int_cst_sgn (top) < 0
- || tree_int_cst_sgn (bottom) < 0)))
- return 0;
- return integer_zerop (const_binop (TRUNC_MOD_EXPR,
- top, bottom, 0));
+ tdiff = fold_build2 (MINUS_EXPR, type, toffset1, toffset2);
+ if (!cst_and_fits_in_hwi (tdiff))
+ return false;
- default:
- return 0;
+ *diff = int_cst_value (tdiff);
}
-}
-
-/* Return true if `t' is known to be non-negative. */
-
-int
-tree_expr_nonnegative_p (t)
- tree t;
-{
- switch (TREE_CODE (t))
+ else if (toffset1 || toffset2)
{
- case ABS_EXPR:
- case FFS_EXPR:
- return 1;
- case INTEGER_CST:
- return tree_int_cst_sgn (t) >= 0;
- case TRUNC_DIV_EXPR:
- case CEIL_DIV_EXPR:
- case FLOOR_DIV_EXPR:
- case ROUND_DIV_EXPR:
- return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
- && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
- case TRUNC_MOD_EXPR:
- case CEIL_MOD_EXPR:
- case FLOOR_MOD_EXPR:
- case ROUND_MOD_EXPR:
- return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
- case COND_EXPR:
- return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
- && tree_expr_nonnegative_p (TREE_OPERAND (t, 2));
- case COMPOUND_EXPR:
- return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
- case MIN_EXPR:
- return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
- && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
- case MAX_EXPR:
- return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
- || tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
- case MODIFY_EXPR:
- return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
- case BIND_EXPR:
- return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
- case SAVE_EXPR:
- return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
- case NON_LVALUE_EXPR:
- return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
- case RTL_EXPR:
- return rtl_expr_nonnegative_p (RTL_EXPR_RTL (t));
-
- default:
- if (truth_value_p (TREE_CODE (t)))
- /* Truth values evaluate to 0 or 1, which is nonnegative. */
- return 1;
- else
- /* We don't know sign of `t', so be conservative and return false. */
- return 0;
+ /* If only one of the offsets is non-constant, the difference cannot
+ be a constant. */
+ return false;
}
+ else
+ *diff = 0;
+
+ *diff += (bitpos1 - bitpos2) / BITS_PER_UNIT;
+ return true;
}
-/* Return true if `r' is known to be non-negative.
- Only handles constants at the moment. */
+/* Simplify the floating point expression EXP when the sign of the
+ result is not significant. Return NULL_TREE if no simplification
+ is possible. */
-int
-rtl_expr_nonnegative_p (r)
- rtx r;
+tree
+fold_strip_sign_ops (tree exp)
{
- switch (GET_CODE (r))
+ tree arg0, arg1;
+
+ switch (TREE_CODE (exp))
{
- case CONST_INT:
- return INTVAL (r) >= 0;
+ case ABS_EXPR:
+ case NEGATE_EXPR:
+ arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
+ return arg0 ? arg0 : TREE_OPERAND (exp, 0);
- case CONST_DOUBLE:
- if (GET_MODE (r) == VOIDmode)
- return CONST_DOUBLE_HIGH (r) >= 0;
- return 0;
+ case MULT_EXPR:
+ case RDIV_EXPR:
+ if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (exp))))
+ return NULL_TREE;
+ arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
+ arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
+ if (arg0 != NULL_TREE || arg1 != NULL_TREE)
+ return fold_build2 (TREE_CODE (exp), TREE_TYPE (exp),
+ arg0 ? arg0 : TREE_OPERAND (exp, 0),
+ arg1 ? arg1 : TREE_OPERAND (exp, 1));
+ break;
- case CONST_VECTOR:
+ case COMPOUND_EXPR:
+ arg0 = TREE_OPERAND (exp, 0);
+ arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
+ if (arg1)
+ return fold_build2 (COMPOUND_EXPR, TREE_TYPE (exp), arg0, arg1);
+ break;
+
+ case COND_EXPR:
+ arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
+ arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 2));
+ if (arg0 || arg1)
+ return fold_build3 (COND_EXPR, TREE_TYPE (exp), TREE_OPERAND (exp, 0),
+ arg0 ? arg0 : TREE_OPERAND (exp, 1),
+ arg1 ? arg1 : TREE_OPERAND (exp, 2));
+ break;
+
+ case CALL_EXPR:
{
- int units, i;
- rtx elt;
-
- units = CONST_VECTOR_NUNITS (r);
-
- for (i = 0; i < units; ++i)
- {
- elt = CONST_VECTOR_ELT (r, i);
- if (!rtl_expr_nonnegative_p (elt))
- return 0;
- }
+ const enum built_in_function fcode = builtin_mathfn_code (exp);
+ switch (fcode)
+ {
+ CASE_FLT_FN (BUILT_IN_COPYSIGN):
+ /* Strip copysign function call, return the 1st argument. */
+ arg0 = CALL_EXPR_ARG (exp, 0);
+ arg1 = CALL_EXPR_ARG (exp, 1);
+ return omit_one_operand (TREE_TYPE (exp), arg0, arg1);
- return 1;
+ default:
+ /* Strip sign ops from the argument of "odd" math functions. */
+ if (negate_mathfn_p (fcode))
+ {
+ arg0 = fold_strip_sign_ops (CALL_EXPR_ARG (exp, 0));
+ if (arg0)
+ return build_call_expr (get_callee_fndecl (exp), 1, arg0);
+ }
+ break;
+ }
}
-
- case SYMBOL_REF:
- case LABEL_REF:
- /* These are always nonnegative. */
- return 1;
+ break;
default:
- return 0;
+ break;
}
+ return NULL_TREE;
}
projects / msp430-gcc.git / blobdiff