--- /dev/null
+/* SSA-PRE for trees.
+ Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
+ Free Software Foundation, Inc.
+ Contributed by Daniel Berlin <dan@dberlin.org> and Steven Bosscher
+ <stevenb@suse.de>
+
+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 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "ggc.h"
+#include "tree.h"
+#include "basic-block.h"
+#include "diagnostic.h"
+#include "tree-inline.h"
+#include "tree-flow.h"
+#include "gimple.h"
+#include "tree-dump.h"
+#include "timevar.h"
+#include "fibheap.h"
+#include "hashtab.h"
+#include "tree-iterator.h"
+#include "real.h"
+#include "alloc-pool.h"
+#include "obstack.h"
+#include "tree-pass.h"
+#include "flags.h"
+#include "bitmap.h"
+#include "langhooks.h"
+#include "cfgloop.h"
+#include "tree-ssa-sccvn.h"
+#include "params.h"
+#include "dbgcnt.h"
+
+/* TODO:
+
+ 1. Avail sets can be shared by making an avail_find_leader that
+ walks up the dominator tree and looks in those avail sets.
+ This might affect code optimality, it's unclear right now.
+ 2. Strength reduction can be performed by anticipating expressions
+ we can repair later on.
+ 3. We can do back-substitution or smarter value numbering to catch
+ commutative expressions split up over multiple statements.
+*/
+
+/* For ease of terminology, "expression node" in the below refers to
+ every expression node but GIMPLE_ASSIGN, because GIMPLE_ASSIGNs
+ represent the actual statement containing the expressions we care about,
+ and we cache the value number by putting it in the expression. */
+
+/* Basic algorithm
+
+ First we walk the statements to generate the AVAIL sets, the
+ EXP_GEN sets, and the tmp_gen sets. EXP_GEN sets represent the
+ generation of values/expressions by a given block. We use them
+ when computing the ANTIC sets. The AVAIL sets consist of
+ SSA_NAME's that represent values, so we know what values are
+ available in what blocks. AVAIL is a forward dataflow problem. In
+ SSA, values are never killed, so we don't need a kill set, or a
+ fixpoint iteration, in order to calculate the AVAIL sets. In
+ traditional parlance, AVAIL sets tell us the downsafety of the
+ expressions/values.
+
+ Next, we generate the ANTIC sets. These sets represent the
+ anticipatable expressions. ANTIC is a backwards dataflow
+ problem. An expression is anticipatable in a given block if it could
+ be generated in that block. This means that if we had to perform
+ an insertion in that block, of the value of that expression, we
+ could. Calculating the ANTIC sets requires phi translation of
+ expressions, because the flow goes backwards through phis. We must
+ iterate to a fixpoint of the ANTIC sets, because we have a kill
+ set. Even in SSA form, values are not live over the entire
+ function, only from their definition point onwards. So we have to
+ remove values from the ANTIC set once we go past the definition
+ point of the leaders that make them up.
+ compute_antic/compute_antic_aux performs this computation.
+
+ Third, we perform insertions to make partially redundant
+ expressions fully redundant.
+
+ An expression is partially redundant (excluding partial
+ anticipation) if:
+
+ 1. It is AVAIL in some, but not all, of the predecessors of a
+ given block.
+ 2. It is ANTIC in all the predecessors.
+
+ In order to make it fully redundant, we insert the expression into
+ the predecessors where it is not available, but is ANTIC.
+
+ For the partial anticipation case, we only perform insertion if it
+ is partially anticipated in some block, and fully available in all
+ of the predecessors.
+
+ insert/insert_aux/do_regular_insertion/do_partial_partial_insertion
+ performs these steps.
+
+ Fourth, we eliminate fully redundant expressions.
+ This is a simple statement walk that replaces redundant
+ calculations with the now available values. */
+
+/* Representations of value numbers:
+
+ Value numbers are represented by a representative SSA_NAME. We
+ will create fake SSA_NAME's in situations where we need a
+ representative but do not have one (because it is a complex
+ expression). In order to facilitate storing the value numbers in
+ bitmaps, and keep the number of wasted SSA_NAME's down, we also
+ associate a value_id with each value number, and create full blown
+ ssa_name's only where we actually need them (IE in operands of
+ existing expressions).
+
+ Theoretically you could replace all the value_id's with
+ SSA_NAME_VERSION, but this would allocate a large number of
+ SSA_NAME's (which are each > 30 bytes) just to get a 4 byte number.
+ It would also require an additional indirection at each point we
+ use the value id. */
+
+/* Representation of expressions on value numbers:
+
+ Expressions consisting of value numbers are represented the same
+ way as our VN internally represents them, with an additional
+ "pre_expr" wrapping around them in order to facilitate storing all
+ of the expressions in the same sets. */
+
+/* Representation of sets:
+
+ The dataflow sets do not need to be sorted in any particular order
+ for the majority of their lifetime, are simply represented as two
+ bitmaps, one that keeps track of values present in the set, and one
+ that keeps track of expressions present in the set.
+
+ When we need them in topological order, we produce it on demand by
+ transforming the bitmap into an array and sorting it into topo
+ order. */
+
+/* Type of expression, used to know which member of the PRE_EXPR union
+ is valid. */
+
+enum pre_expr_kind
+{
+ NAME,
+ NARY,
+ REFERENCE,
+ CONSTANT
+};
+
+typedef union pre_expr_union_d
+{
+ tree name;
+ tree constant;
+ vn_nary_op_t nary;
+ vn_reference_t reference;
+} pre_expr_union;
+
+typedef struct pre_expr_d
+{
+ enum pre_expr_kind kind;
+ unsigned int id;
+ pre_expr_union u;
+} *pre_expr;
+
+#define PRE_EXPR_NAME(e) (e)->u.name
+#define PRE_EXPR_NARY(e) (e)->u.nary
+#define PRE_EXPR_REFERENCE(e) (e)->u.reference
+#define PRE_EXPR_CONSTANT(e) (e)->u.constant
+
+static int
+pre_expr_eq (const void *p1, const void *p2)
+{
+ const struct pre_expr_d *e1 = (const struct pre_expr_d *) p1;
+ const struct pre_expr_d *e2 = (const struct pre_expr_d *) p2;
+
+ if (e1->kind != e2->kind)
+ return false;
+
+ switch (e1->kind)
+ {
+ case CONSTANT:
+ return vn_constant_eq_with_type (PRE_EXPR_CONSTANT (e1),
+ PRE_EXPR_CONSTANT (e2));
+ case NAME:
+ return PRE_EXPR_NAME (e1) == PRE_EXPR_NAME (e2);
+ case NARY:
+ return vn_nary_op_eq (PRE_EXPR_NARY (e1), PRE_EXPR_NARY (e2));
+ case REFERENCE:
+ return vn_reference_eq (PRE_EXPR_REFERENCE (e1),
+ PRE_EXPR_REFERENCE (e2));
+ default:
+ abort();
+ }
+}
+
+static hashval_t
+pre_expr_hash (const void *p1)
+{
+ const struct pre_expr_d *e = (const struct pre_expr_d *) p1;
+ switch (e->kind)
+ {
+ case CONSTANT:
+ return vn_hash_constant_with_type (PRE_EXPR_CONSTANT (e));
+ case NAME:
+ return iterative_hash_hashval_t (SSA_NAME_VERSION (PRE_EXPR_NAME (e)), 0);
+ case NARY:
+ return PRE_EXPR_NARY (e)->hashcode;
+ case REFERENCE:
+ return PRE_EXPR_REFERENCE (e)->hashcode;
+ default:
+ abort ();
+ }
+}
+
+
+/* Next global expression id number. */
+static unsigned int next_expression_id;
+
+/* Mapping from expression to id number we can use in bitmap sets. */
+DEF_VEC_P (pre_expr);
+DEF_VEC_ALLOC_P (pre_expr, heap);
+static VEC(pre_expr, heap) *expressions;
+static htab_t expression_to_id;
+
+/* Allocate an expression id for EXPR. */
+
+static inline unsigned int
+alloc_expression_id (pre_expr expr)
+{
+ void **slot;
+ /* Make sure we won't overflow. */
+ gcc_assert (next_expression_id + 1 > next_expression_id);
+ expr->id = next_expression_id++;
+ VEC_safe_push (pre_expr, heap, expressions, expr);
+ slot = htab_find_slot (expression_to_id, expr, INSERT);
+ gcc_assert (!*slot);
+ *slot = expr;
+ return next_expression_id - 1;
+}
+
+/* Return the expression id for tree EXPR. */
+
+static inline unsigned int
+get_expression_id (const pre_expr expr)
+{
+ return expr->id;
+}
+
+static inline unsigned int
+lookup_expression_id (const pre_expr expr)
+{
+ void **slot;
+
+ slot = htab_find_slot (expression_to_id, expr, NO_INSERT);
+ if (!slot)
+ return 0;
+ return ((pre_expr)*slot)->id;
+}
+
+/* Return the existing expression id for EXPR, or create one if one
+ does not exist yet. */
+
+static inline unsigned int
+get_or_alloc_expression_id (pre_expr expr)
+{
+ unsigned int id = lookup_expression_id (expr);
+ if (id == 0)
+ return alloc_expression_id (expr);
+ return expr->id = id;
+}
+
+/* Return the expression that has expression id ID */
+
+static inline pre_expr
+expression_for_id (unsigned int id)
+{
+ return VEC_index (pre_expr, expressions, id);
+}
+
+/* Free the expression id field in all of our expressions,
+ and then destroy the expressions array. */
+
+static void
+clear_expression_ids (void)
+{
+ VEC_free (pre_expr, heap, expressions);
+}
+
+static alloc_pool pre_expr_pool;
+
+/* Given an SSA_NAME NAME, get or create a pre_expr to represent it. */
+
+static pre_expr
+get_or_alloc_expr_for_name (tree name)
+{
+ pre_expr result = (pre_expr) pool_alloc (pre_expr_pool);
+ unsigned int result_id;
+
+ result->kind = NAME;
+ result->id = 0;
+ PRE_EXPR_NAME (result) = name;
+ result_id = lookup_expression_id (result);
+ if (result_id != 0)
+ {
+ pool_free (pre_expr_pool, result);
+ result = expression_for_id (result_id);
+ return result;
+ }
+ get_or_alloc_expression_id (result);
+ return result;
+}
+
+static bool in_fre = false;
+
+/* An unordered bitmap set. One bitmap tracks values, the other,
+ expressions. */
+typedef struct bitmap_set
+{
+ bitmap expressions;
+ bitmap values;
+} *bitmap_set_t;
+
+#define FOR_EACH_EXPR_ID_IN_SET(set, id, bi) \
+ EXECUTE_IF_SET_IN_BITMAP((set)->expressions, 0, (id), (bi))
+
+#define FOR_EACH_VALUE_ID_IN_SET(set, id, bi) \
+ EXECUTE_IF_SET_IN_BITMAP((set)->values, 0, (id), (bi))
+
+/* Mapping from value id to expressions with that value_id. */
+DEF_VEC_P (bitmap_set_t);
+DEF_VEC_ALLOC_P (bitmap_set_t, heap);
+static VEC(bitmap_set_t, heap) *value_expressions;
+
+/* Sets that we need to keep track of. */
+typedef struct bb_bitmap_sets
+{
+ /* The EXP_GEN set, which represents expressions/values generated in
+ a basic block. */
+ bitmap_set_t exp_gen;
+
+ /* The PHI_GEN set, which represents PHI results generated in a
+ basic block. */
+ bitmap_set_t phi_gen;
+
+ /* The TMP_GEN set, which represents results/temporaries generated
+ in a basic block. IE the LHS of an expression. */
+ bitmap_set_t tmp_gen;
+
+ /* The AVAIL_OUT set, which represents which values are available in
+ a given basic block. */
+ bitmap_set_t avail_out;
+
+ /* The ANTIC_IN set, which represents which values are anticipatable
+ in a given basic block. */
+ bitmap_set_t antic_in;
+
+ /* The PA_IN set, which represents which values are
+ partially anticipatable in a given basic block. */
+ bitmap_set_t pa_in;
+
+ /* The NEW_SETS set, which is used during insertion to augment the
+ AVAIL_OUT set of blocks with the new insertions performed during
+ the current iteration. */
+ bitmap_set_t new_sets;
+
+ /* True if we have visited this block during ANTIC calculation. */
+ unsigned int visited:1;
+
+ /* True we have deferred processing this block during ANTIC
+ calculation until its successor is processed. */
+ unsigned int deferred : 1;
+} *bb_value_sets_t;
+
+#define EXP_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->exp_gen
+#define PHI_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->phi_gen
+#define TMP_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->tmp_gen
+#define AVAIL_OUT(BB) ((bb_value_sets_t) ((BB)->aux))->avail_out
+#define ANTIC_IN(BB) ((bb_value_sets_t) ((BB)->aux))->antic_in
+#define PA_IN(BB) ((bb_value_sets_t) ((BB)->aux))->pa_in
+#define NEW_SETS(BB) ((bb_value_sets_t) ((BB)->aux))->new_sets
+#define BB_VISITED(BB) ((bb_value_sets_t) ((BB)->aux))->visited
+#define BB_DEFERRED(BB) ((bb_value_sets_t) ((BB)->aux))->deferred
+
+
+/* Basic block list in postorder. */
+static int *postorder;
+
+/* This structure is used to keep track of statistics on what
+ optimization PRE was able to perform. */
+static struct
+{
+ /* The number of RHS computations eliminated by PRE. */
+ int eliminations;
+
+ /* The number of new expressions/temporaries generated by PRE. */
+ int insertions;
+
+ /* The number of inserts found due to partial anticipation */
+ int pa_insert;
+
+ /* The number of new PHI nodes added by PRE. */
+ int phis;
+
+ /* The number of values found constant. */
+ int constified;
+
+} pre_stats;
+
+static bool do_partial_partial;
+static pre_expr bitmap_find_leader (bitmap_set_t, unsigned int, gimple);
+static void bitmap_value_insert_into_set (bitmap_set_t, pre_expr);
+static void bitmap_value_replace_in_set (bitmap_set_t, pre_expr);
+static void bitmap_set_copy (bitmap_set_t, bitmap_set_t);
+static bool bitmap_set_contains_value (bitmap_set_t, unsigned int);
+static void bitmap_insert_into_set (bitmap_set_t, pre_expr);
+static void bitmap_insert_into_set_1 (bitmap_set_t, pre_expr, bool);
+static bitmap_set_t bitmap_set_new (void);
+static tree create_expression_by_pieces (basic_block, pre_expr, gimple_seq *,
+ gimple, tree);
+static tree find_or_generate_expression (basic_block, pre_expr, gimple_seq *,
+ gimple);
+static unsigned int get_expr_value_id (pre_expr);
+
+/* We can add and remove elements and entries to and from sets
+ and hash tables, so we use alloc pools for them. */
+
+static alloc_pool bitmap_set_pool;
+static bitmap_obstack grand_bitmap_obstack;
+
+/* To avoid adding 300 temporary variables when we only need one, we
+ only create one temporary variable, on demand, and build ssa names
+ off that. We do have to change the variable if the types don't
+ match the current variable's type. */
+static tree pretemp;
+static tree storetemp;
+static tree prephitemp;
+
+/* Set of blocks with statements that have had its EH information
+ cleaned up. */
+static bitmap need_eh_cleanup;
+
+/* The phi_translate_table caches phi translations for a given
+ expression and predecessor. */
+
+static htab_t phi_translate_table;
+
+/* A three tuple {e, pred, v} used to cache phi translations in the
+ phi_translate_table. */
+
+typedef struct expr_pred_trans_d
+{
+ /* The expression. */
+ pre_expr e;
+
+ /* The predecessor block along which we translated the expression. */
+ basic_block pred;
+
+ /* The value that resulted from the translation. */
+ pre_expr v;
+
+ /* The hashcode for the expression, pred pair. This is cached for
+ speed reasons. */
+ hashval_t hashcode;
+} *expr_pred_trans_t;
+typedef const struct expr_pred_trans_d *const_expr_pred_trans_t;
+
+/* Return the hash value for a phi translation table entry. */
+
+static hashval_t
+expr_pred_trans_hash (const void *p)
+{
+ const_expr_pred_trans_t const ve = (const_expr_pred_trans_t) p;
+ return ve->hashcode;
+}
+
+/* Return true if two phi translation table entries are the same.
+ P1 and P2 should point to the expr_pred_trans_t's to be compared.*/
+
+static int
+expr_pred_trans_eq (const void *p1, const void *p2)
+{
+ const_expr_pred_trans_t const ve1 = (const_expr_pred_trans_t) p1;
+ const_expr_pred_trans_t const ve2 = (const_expr_pred_trans_t) p2;
+ basic_block b1 = ve1->pred;
+ basic_block b2 = ve2->pred;
+
+ /* If they are not translations for the same basic block, they can't
+ be equal. */
+ if (b1 != b2)
+ return false;
+ return pre_expr_eq (ve1->e, ve2->e);
+}
+
+/* Search in the phi translation table for the translation of
+ expression E in basic block PRED.
+ Return the translated value, if found, NULL otherwise. */
+
+static inline pre_expr
+phi_trans_lookup (pre_expr e, basic_block pred)
+{
+ void **slot;
+ struct expr_pred_trans_d ept;
+
+ ept.e = e;
+ ept.pred = pred;
+ ept.hashcode = iterative_hash_hashval_t (pre_expr_hash (e), pred->index);
+ slot = htab_find_slot_with_hash (phi_translate_table, &ept, ept.hashcode,
+ NO_INSERT);
+ if (!slot)
+ return NULL;
+ else
+ return ((expr_pred_trans_t) *slot)->v;
+}
+
+
+/* Add the tuple mapping from {expression E, basic block PRED} to
+ value V, to the phi translation table. */
+
+static inline void
+phi_trans_add (pre_expr e, pre_expr v, basic_block pred)
+{
+ void **slot;
+ expr_pred_trans_t new_pair = XNEW (struct expr_pred_trans_d);
+ new_pair->e = e;
+ new_pair->pred = pred;
+ new_pair->v = v;
+ new_pair->hashcode = iterative_hash_hashval_t (pre_expr_hash (e),
+ pred->index);
+
+ slot = htab_find_slot_with_hash (phi_translate_table, new_pair,
+ new_pair->hashcode, INSERT);
+ if (*slot)
+ free (*slot);
+ *slot = (void *) new_pair;
+}
+
+
+/* Add expression E to the expression set of value id V. */
+
+void
+add_to_value (unsigned int v, pre_expr e)
+{
+ bitmap_set_t set;
+
+ gcc_assert (get_expr_value_id (e) == v);
+
+ if (v >= VEC_length (bitmap_set_t, value_expressions))
+ {
+ VEC_safe_grow_cleared (bitmap_set_t, heap, value_expressions,
+ v + 1);
+ }
+
+ set = VEC_index (bitmap_set_t, value_expressions, v);
+ if (!set)
+ {
+ set = bitmap_set_new ();
+ VEC_replace (bitmap_set_t, value_expressions, v, set);
+ }
+
+ bitmap_insert_into_set_1 (set, e, true);
+}
+
+/* Create a new bitmap set and return it. */
+
+static bitmap_set_t
+bitmap_set_new (void)
+{
+ bitmap_set_t ret = (bitmap_set_t) pool_alloc (bitmap_set_pool);
+ ret->expressions = BITMAP_ALLOC (&grand_bitmap_obstack);
+ ret->values = BITMAP_ALLOC (&grand_bitmap_obstack);
+ return ret;
+}
+
+/* Return the value id for a PRE expression EXPR. */
+
+static unsigned int
+get_expr_value_id (pre_expr expr)
+{
+ switch (expr->kind)
+ {
+ case CONSTANT:
+ {
+ unsigned int id;
+ id = get_constant_value_id (PRE_EXPR_CONSTANT (expr));
+ if (id == 0)
+ {
+ id = get_or_alloc_constant_value_id (PRE_EXPR_CONSTANT (expr));
+ add_to_value (id, expr);
+ }
+ return id;
+ }
+ case NAME:
+ return VN_INFO (PRE_EXPR_NAME (expr))->value_id;
+ case NARY:
+ return PRE_EXPR_NARY (expr)->value_id;
+ case REFERENCE:
+ return PRE_EXPR_REFERENCE (expr)->value_id;
+ default:
+ gcc_unreachable ();
+ }
+}
+
+/* Remove an expression EXPR from a bitmapped set. */
+
+static void
+bitmap_remove_from_set (bitmap_set_t set, pre_expr expr)
+{
+ unsigned int val = get_expr_value_id (expr);
+ if (!value_id_constant_p (val))
+ {
+ bitmap_clear_bit (set->values, val);
+ bitmap_clear_bit (set->expressions, get_expression_id (expr));
+ }
+}
+
+static void
+bitmap_insert_into_set_1 (bitmap_set_t set, pre_expr expr,
+ bool allow_constants)
+{
+ unsigned int val = get_expr_value_id (expr);
+ if (allow_constants || !value_id_constant_p (val))
+ {
+ /* We specifically expect this and only this function to be able to
+ insert constants into a set. */
+ bitmap_set_bit (set->values, val);
+ bitmap_set_bit (set->expressions, get_or_alloc_expression_id (expr));
+ }
+}
+
+/* Insert an expression EXPR into a bitmapped set. */
+
+static void
+bitmap_insert_into_set (bitmap_set_t set, pre_expr expr)
+{
+ bitmap_insert_into_set_1 (set, expr, false);
+}
+
+/* Copy a bitmapped set ORIG, into bitmapped set DEST. */
+
+static void
+bitmap_set_copy (bitmap_set_t dest, bitmap_set_t orig)
+{
+ bitmap_copy (dest->expressions, orig->expressions);
+ bitmap_copy (dest->values, orig->values);
+}
+
+
+/* Free memory used up by SET. */
+static void
+bitmap_set_free (bitmap_set_t set)
+{
+ BITMAP_FREE (set->expressions);
+ BITMAP_FREE (set->values);
+}
+
+
+/* Generate an topological-ordered array of bitmap set SET. */
+
+static VEC(pre_expr, heap) *
+sorted_array_from_bitmap_set (bitmap_set_t set)
+{
+ unsigned int i, j;
+ bitmap_iterator bi, bj;
+ VEC(pre_expr, heap) *result = NULL;
+
+ FOR_EACH_VALUE_ID_IN_SET (set, i, bi)
+ {
+ /* The number of expressions having a given value is usually
+ relatively small. Thus, rather than making a vector of all
+ the expressions and sorting it by value-id, we walk the values
+ and check in the reverse mapping that tells us what expressions
+ have a given value, to filter those in our set. As a result,
+ the expressions are inserted in value-id order, which means
+ topological order.
+
+ If this is somehow a significant lose for some cases, we can
+ choose which set to walk based on the set size. */
+ bitmap_set_t exprset = VEC_index (bitmap_set_t, value_expressions, i);
+ FOR_EACH_EXPR_ID_IN_SET (exprset, j, bj)
+ {
+ if (bitmap_bit_p (set->expressions, j))
+ VEC_safe_push (pre_expr, heap, result, expression_for_id (j));
+ }
+ }
+
+ return result;
+}
+
+/* Perform bitmapped set operation DEST &= ORIG. */
+
+static void
+bitmap_set_and (bitmap_set_t dest, bitmap_set_t orig)
+{
+ bitmap_iterator bi;
+ unsigned int i;
+
+ if (dest != orig)
+ {
+ bitmap temp = BITMAP_ALLOC (&grand_bitmap_obstack);
+
+ bitmap_and_into (dest->values, orig->values);
+ bitmap_copy (temp, dest->expressions);
+ EXECUTE_IF_SET_IN_BITMAP (temp, 0, i, bi)
+ {
+ pre_expr expr = expression_for_id (i);
+ unsigned int value_id = get_expr_value_id (expr);
+ if (!bitmap_bit_p (dest->values, value_id))
+ bitmap_clear_bit (dest->expressions, i);
+ }
+ BITMAP_FREE (temp);
+ }
+}
+
+/* Subtract all values and expressions contained in ORIG from DEST. */
+
+static bitmap_set_t
+bitmap_set_subtract (bitmap_set_t dest, bitmap_set_t orig)
+{
+ bitmap_set_t result = bitmap_set_new ();
+ bitmap_iterator bi;
+ unsigned int i;
+
+ bitmap_and_compl (result->expressions, dest->expressions,
+ orig->expressions);
+
+ FOR_EACH_EXPR_ID_IN_SET (result, i, bi)
+ {
+ pre_expr expr = expression_for_id (i);
+ unsigned int value_id = get_expr_value_id (expr);
+ bitmap_set_bit (result->values, value_id);
+ }
+
+ return result;
+}
+
+/* Subtract all the values in bitmap set B from bitmap set A. */
+
+static void
+bitmap_set_subtract_values (bitmap_set_t a, bitmap_set_t b)
+{
+ unsigned int i;
+ bitmap_iterator bi;
+ bitmap temp = BITMAP_ALLOC (&grand_bitmap_obstack);
+
+ bitmap_copy (temp, a->expressions);
+ EXECUTE_IF_SET_IN_BITMAP (temp, 0, i, bi)
+ {
+ pre_expr expr = expression_for_id (i);
+ if (bitmap_set_contains_value (b, get_expr_value_id (expr)))
+ bitmap_remove_from_set (a, expr);
+ }
+ BITMAP_FREE (temp);
+}
+
+
+/* Return true if bitmapped set SET contains the value VALUE_ID. */
+
+static bool
+bitmap_set_contains_value (bitmap_set_t set, unsigned int value_id)
+{
+ if (value_id_constant_p (value_id))
+ return true;
+
+ if (!set || bitmap_empty_p (set->expressions))
+ return false;
+
+ return bitmap_bit_p (set->values, value_id);
+}
+
+static inline bool
+bitmap_set_contains_expr (bitmap_set_t set, const pre_expr expr)
+{
+ return bitmap_bit_p (set->expressions, get_expression_id (expr));
+}
+
+/* Replace an instance of value LOOKFOR with expression EXPR in SET. */
+
+static void
+bitmap_set_replace_value (bitmap_set_t set, unsigned int lookfor,
+ const pre_expr expr)
+{
+ bitmap_set_t exprset;
+ unsigned int i;
+ bitmap_iterator bi;
+
+ if (value_id_constant_p (lookfor))
+ return;
+
+ if (!bitmap_set_contains_value (set, lookfor))
+ return;
+
+ /* The number of expressions having a given value is usually
+ significantly less than the total number of expressions in SET.
+ Thus, rather than check, for each expression in SET, whether it
+ has the value LOOKFOR, we walk the reverse mapping that tells us
+ what expressions have a given value, and see if any of those
+ expressions are in our set. For large testcases, this is about
+ 5-10x faster than walking the bitmap. If this is somehow a
+ significant lose for some cases, we can choose which set to walk
+ based on the set size. */
+ exprset = VEC_index (bitmap_set_t, value_expressions, lookfor);
+ FOR_EACH_EXPR_ID_IN_SET (exprset, i, bi)
+ {
+ if (bitmap_bit_p (set->expressions, i))
+ {
+ bitmap_clear_bit (set->expressions, i);
+ bitmap_set_bit (set->expressions, get_expression_id (expr));
+ return;
+ }
+ }
+}
+
+/* Return true if two bitmap sets are equal. */
+
+static bool
+bitmap_set_equal (bitmap_set_t a, bitmap_set_t b)
+{
+ return bitmap_equal_p (a->values, b->values);
+}
+
+/* Replace an instance of EXPR's VALUE with EXPR in SET if it exists,
+ and add it otherwise. */
+
+static void
+bitmap_value_replace_in_set (bitmap_set_t set, pre_expr expr)
+{
+ unsigned int val = get_expr_value_id (expr);
+
+ if (bitmap_set_contains_value (set, val))
+ bitmap_set_replace_value (set, val, expr);
+ else
+ bitmap_insert_into_set (set, expr);
+}
+
+/* Insert EXPR into SET if EXPR's value is not already present in
+ SET. */
+
+static void
+bitmap_value_insert_into_set (bitmap_set_t set, pre_expr expr)
+{
+ unsigned int val = get_expr_value_id (expr);
+
+ if (value_id_constant_p (val))
+ return;
+
+ if (!bitmap_set_contains_value (set, val))
+ bitmap_insert_into_set (set, expr);
+}
+
+/* Print out EXPR to outfile. */
+
+static void
+print_pre_expr (FILE *outfile, const pre_expr expr)
+{
+ switch (expr->kind)
+ {
+ case CONSTANT:
+ print_generic_expr (outfile, PRE_EXPR_CONSTANT (expr), 0);
+ break;
+ case NAME:
+ print_generic_expr (outfile, PRE_EXPR_NAME (expr), 0);
+ break;
+ case NARY:
+ {
+ unsigned int i;
+ vn_nary_op_t nary = PRE_EXPR_NARY (expr);
+ fprintf (outfile, "{%s,", tree_code_name [nary->opcode]);
+ for (i = 0; i < nary->length; i++)
+ {
+ print_generic_expr (outfile, nary->op[i], 0);
+ if (i != (unsigned) nary->length - 1)
+ fprintf (outfile, ",");
+ }
+ fprintf (outfile, "}");
+ }
+ break;
+
+ case REFERENCE:
+ {
+ vn_reference_op_t vro;
+ unsigned int i;
+ vn_reference_t ref = PRE_EXPR_REFERENCE (expr);
+ fprintf (outfile, "{");
+ for (i = 0;
+ VEC_iterate (vn_reference_op_s, ref->operands, i, vro);
+ i++)
+ {
+ if (vro->opcode != SSA_NAME
+ && TREE_CODE_CLASS (vro->opcode) != tcc_declaration)
+ fprintf (outfile, "%s ", tree_code_name [vro->opcode]);
+ if (vro->op0)
+ {
+ if (vro->op1)
+ fprintf (outfile, "<");
+ print_generic_expr (outfile, vro->op0, 0);
+ if (vro->op1)
+ {
+ fprintf (outfile, ",");
+ print_generic_expr (outfile, vro->op1, 0);
+ }
+ if (vro->op1)
+ fprintf (outfile, ">");
+ }
+ if (i != VEC_length (vn_reference_op_s, ref->operands) - 1)
+ fprintf (outfile, ",");
+ }
+ fprintf (outfile, "}");
+ }
+ break;
+ }
+}
+void debug_pre_expr (pre_expr);
+
+/* Like print_pre_expr but always prints to stderr. */
+void
+debug_pre_expr (pre_expr e)
+{
+ print_pre_expr (stderr, e);
+ fprintf (stderr, "\n");
+}
+
+/* Print out SET to OUTFILE. */
+
+static void
+print_bitmap_set (FILE *outfile, bitmap_set_t set,
+ const char *setname, int blockindex)
+{
+ fprintf (outfile, "%s[%d] := { ", setname, blockindex);
+ if (set)
+ {
+ bool first = true;
+ unsigned i;
+ bitmap_iterator bi;
+
+ FOR_EACH_EXPR_ID_IN_SET (set, i, bi)
+ {
+ const pre_expr expr = expression_for_id (i);
+
+ if (!first)
+ fprintf (outfile, ", ");
+ first = false;
+ print_pre_expr (outfile, expr);
+
+ fprintf (outfile, " (%04d)", get_expr_value_id (expr));
+ }
+ }
+ fprintf (outfile, " }\n");
+}
+
+void debug_bitmap_set (bitmap_set_t);
+
+void
+debug_bitmap_set (bitmap_set_t set)
+{
+ print_bitmap_set (stderr, set, "debug", 0);
+}
+
+/* Print out the expressions that have VAL to OUTFILE. */
+
+void
+print_value_expressions (FILE *outfile, unsigned int val)
+{
+ bitmap_set_t set = VEC_index (bitmap_set_t, value_expressions, val);
+ if (set)
+ {
+ char s[10];
+ sprintf (s, "%04d", val);
+ print_bitmap_set (outfile, set, s, 0);
+ }
+}
+
+
+void
+debug_value_expressions (unsigned int val)
+{
+ print_value_expressions (stderr, val);
+}
+
+/* Given a CONSTANT, allocate a new CONSTANT type PRE_EXPR to
+ represent it. */
+
+static pre_expr
+get_or_alloc_expr_for_constant (tree constant)
+{
+ unsigned int result_id;
+ unsigned int value_id;
+ pre_expr newexpr = (pre_expr) pool_alloc (pre_expr_pool);
+ newexpr->kind = CONSTANT;
+ PRE_EXPR_CONSTANT (newexpr) = constant;
+ result_id = lookup_expression_id (newexpr);
+ if (result_id != 0)
+ {
+ pool_free (pre_expr_pool, newexpr);
+ newexpr = expression_for_id (result_id);
+ return newexpr;
+ }
+ value_id = get_or_alloc_constant_value_id (constant);
+ get_or_alloc_expression_id (newexpr);
+ add_to_value (value_id, newexpr);
+ return newexpr;
+}
+
+/* Given a value id V, find the actual tree representing the constant
+ value if there is one, and return it. Return NULL if we can't find
+ a constant. */
+
+static tree
+get_constant_for_value_id (unsigned int v)
+{
+ if (value_id_constant_p (v))
+ {
+ unsigned int i;
+ bitmap_iterator bi;
+ bitmap_set_t exprset = VEC_index (bitmap_set_t, value_expressions, v);
+
+ FOR_EACH_EXPR_ID_IN_SET (exprset, i, bi)
+ {
+ pre_expr expr = expression_for_id (i);
+ if (expr->kind == CONSTANT)
+ return PRE_EXPR_CONSTANT (expr);
+ }
+ }
+ return NULL;
+}
+
+/* Get or allocate a pre_expr for a piece of GIMPLE, and return it.
+ Currently only supports constants and SSA_NAMES. */
+static pre_expr
+get_or_alloc_expr_for (tree t)
+{
+ if (TREE_CODE (t) == SSA_NAME)
+ return get_or_alloc_expr_for_name (t);
+ else if (is_gimple_min_invariant (t))
+ return get_or_alloc_expr_for_constant (t);
+ else
+ {
+ /* More complex expressions can result from SCCVN expression
+ simplification that inserts values for them. As they all
+ do not have VOPs the get handled by the nary ops struct. */
+ vn_nary_op_t result;
+ unsigned int result_id;
+ vn_nary_op_lookup (t, &result);
+ if (result != NULL)
+ {
+ pre_expr e = (pre_expr) pool_alloc (pre_expr_pool);
+ e->kind = NARY;
+ PRE_EXPR_NARY (e) = result;
+ result_id = lookup_expression_id (e);
+ if (result_id != 0)
+ {
+ pool_free (pre_expr_pool, e);
+ e = expression_for_id (result_id);
+ return e;
+ }
+ alloc_expression_id (e);
+ return e;
+ }
+ }
+ return NULL;
+}
+
+/* Return the folded version of T if T, when folded, is a gimple
+ min_invariant. Otherwise, return T. */
+
+static pre_expr
+fully_constant_expression (pre_expr e)
+{
+ switch (e->kind)
+ {
+ case CONSTANT:
+ return e;
+ case NARY:
+ {
+ vn_nary_op_t nary = PRE_EXPR_NARY (e);
+ switch (TREE_CODE_CLASS (nary->opcode))
+ {
+ case tcc_expression:
+ if (nary->opcode == TRUTH_NOT_EXPR)
+ goto do_unary;
+ if (nary->opcode != TRUTH_AND_EXPR
+ && nary->opcode != TRUTH_OR_EXPR
+ && nary->opcode != TRUTH_XOR_EXPR)
+ return e;
+ /* Fallthrough. */
+ case tcc_binary:
+ case tcc_comparison:
+ {
+ /* We have to go from trees to pre exprs to value ids to
+ constants. */
+ tree naryop0 = nary->op[0];
+ tree naryop1 = nary->op[1];
+ tree result;
+ if (!is_gimple_min_invariant (naryop0))
+ {
+ pre_expr rep0 = get_or_alloc_expr_for (naryop0);
+ unsigned int vrep0 = get_expr_value_id (rep0);
+ tree const0 = get_constant_for_value_id (vrep0);
+ if (const0)
+ naryop0 = fold_convert (TREE_TYPE (naryop0), const0);
+ }
+ if (!is_gimple_min_invariant (naryop1))
+ {
+ pre_expr rep1 = get_or_alloc_expr_for (naryop1);
+ unsigned int vrep1 = get_expr_value_id (rep1);
+ tree const1 = get_constant_for_value_id (vrep1);
+ if (const1)
+ naryop1 = fold_convert (TREE_TYPE (naryop1), const1);
+ }
+ result = fold_binary (nary->opcode, nary->type,
+ naryop0, naryop1);
+ if (result && is_gimple_min_invariant (result))
+ return get_or_alloc_expr_for_constant (result);
+ /* We might have simplified the expression to a
+ SSA_NAME for example from x_1 * 1. But we cannot
+ insert a PHI for x_1 unconditionally as x_1 might
+ not be available readily. */
+ return e;
+ }
+ case tcc_reference:
+ if (nary->opcode != REALPART_EXPR
+ && nary->opcode != IMAGPART_EXPR
+ && nary->opcode != VIEW_CONVERT_EXPR)
+ return e;
+ /* Fallthrough. */
+ case tcc_unary:
+do_unary:
+ {
+ /* We have to go from trees to pre exprs to value ids to
+ constants. */
+ tree naryop0 = nary->op[0];
+ tree const0, result;
+ if (is_gimple_min_invariant (naryop0))
+ const0 = naryop0;
+ else
+ {
+ pre_expr rep0 = get_or_alloc_expr_for (naryop0);
+ unsigned int vrep0 = get_expr_value_id (rep0);
+ const0 = get_constant_for_value_id (vrep0);
+ }
+ result = NULL;
+ if (const0)
+ {
+ tree type1 = TREE_TYPE (nary->op[0]);
+ const0 = fold_convert (type1, const0);
+ result = fold_unary (nary->opcode, nary->type, const0);
+ }
+ if (result && is_gimple_min_invariant (result))
+ return get_or_alloc_expr_for_constant (result);
+ return e;
+ }
+ default:
+ return e;
+ }
+ }
+ case REFERENCE:
+ {
+ vn_reference_t ref = PRE_EXPR_REFERENCE (e);
+ VEC (vn_reference_op_s, heap) *operands = ref->operands;
+ vn_reference_op_t op;
+
+ /* Try to simplify the translated expression if it is
+ a call to a builtin function with at most two arguments. */
+ op = VEC_index (vn_reference_op_s, operands, 0);
+ if (op->opcode == CALL_EXPR
+ && TREE_CODE (op->op0) == ADDR_EXPR
+ && TREE_CODE (TREE_OPERAND (op->op0, 0)) == FUNCTION_DECL
+ && DECL_BUILT_IN (TREE_OPERAND (op->op0, 0))
+ && VEC_length (vn_reference_op_s, operands) >= 2
+ && VEC_length (vn_reference_op_s, operands) <= 3)
+ {
+ vn_reference_op_t arg0, arg1 = NULL;
+ bool anyconst = false;
+ arg0 = VEC_index (vn_reference_op_s, operands, 1);
+ if (VEC_length (vn_reference_op_s, operands) > 2)
+ arg1 = VEC_index (vn_reference_op_s, operands, 2);
+ if (TREE_CODE_CLASS (arg0->opcode) == tcc_constant
+ || (arg0->opcode == ADDR_EXPR
+ && is_gimple_min_invariant (arg0->op0)))
+ anyconst = true;
+ if (arg1
+ && (TREE_CODE_CLASS (arg1->opcode) == tcc_constant
+ || (arg1->opcode == ADDR_EXPR
+ && is_gimple_min_invariant (arg1->op0))))
+ anyconst = true;
+ if (anyconst)
+ {
+ tree folded = build_call_expr (TREE_OPERAND (op->op0, 0),
+ arg1 ? 2 : 1,
+ arg0->op0,
+ arg1 ? arg1->op0 : NULL);
+ if (folded
+ && TREE_CODE (folded) == NOP_EXPR)
+ folded = TREE_OPERAND (folded, 0);
+ if (folded
+ && is_gimple_min_invariant (folded))
+ return get_or_alloc_expr_for_constant (folded);
+ }
+ }
+ return e;
+ }
+ default:
+ return e;
+ }
+ return e;
+}
+
+/* Translate the vuses in the VUSES vector backwards through phi nodes
+ in PHIBLOCK, so that they have the value they would have in
+ BLOCK. */
+
+static VEC(tree, gc) *
+translate_vuses_through_block (VEC (tree, gc) *vuses,
+ basic_block phiblock,
+ basic_block block)
+{
+ tree oldvuse;
+ VEC(tree, gc) *result = NULL;
+ int i;
+
+ for (i = 0; VEC_iterate (tree, vuses, i, oldvuse); i++)
+ {
+ gimple phi = SSA_NAME_DEF_STMT (oldvuse);
+ if (gimple_code (phi) == GIMPLE_PHI
+ && gimple_bb (phi) == phiblock)
+ {
+ edge e = find_edge (block, gimple_bb (phi));
+ if (e)
+ {
+ tree def = PHI_ARG_DEF (phi, e->dest_idx);
+ if (def != oldvuse)
+ {
+ if (!result)
+ result = VEC_copy (tree, gc, vuses);
+ VEC_replace (tree, result, i, def);
+ }
+ }
+ }
+ }
+
+ /* We avoid creating a new copy of the vuses unless something
+ actually changed, so result can be NULL. */
+ if (result)
+ {
+ sort_vuses (result);
+ return result;
+ }
+ return vuses;
+
+}
+
+/* Like find_leader, but checks for the value existing in SET1 *or*
+ SET2. This is used to avoid making a set consisting of the union
+ of PA_IN and ANTIC_IN during insert. */
+
+static inline pre_expr
+find_leader_in_sets (unsigned int val, bitmap_set_t set1, bitmap_set_t set2)
+{
+ pre_expr result;
+
+ result = bitmap_find_leader (set1, val, NULL);
+ if (!result && set2)
+ result = bitmap_find_leader (set2, val, NULL);
+ return result;
+}
+
+/* Get the tree type for our PRE expression e. */
+
+static tree
+get_expr_type (const pre_expr e)
+{
+ switch (e->kind)
+ {
+ case NAME:
+ return TREE_TYPE (PRE_EXPR_NAME (e));
+ case CONSTANT:
+ return TREE_TYPE (PRE_EXPR_CONSTANT (e));
+ case REFERENCE:
+ {
+ vn_reference_op_t vro;
+
+ gcc_assert (PRE_EXPR_REFERENCE (e)->operands);
+ vro = VEC_index (vn_reference_op_s,
+ PRE_EXPR_REFERENCE (e)->operands,
+ 0);
+ /* We don't store type along with COMPONENT_REF because it is
+ always the same as FIELD_DECL's type. */
+ if (!vro->type)
+ {
+ gcc_assert (vro->opcode == COMPONENT_REF);
+ return TREE_TYPE (vro->op0);
+ }
+ return vro->type;
+ }
+
+ case NARY:
+ return PRE_EXPR_NARY (e)->type;
+ }
+ gcc_unreachable();
+}
+
+/* Get a representative SSA_NAME for a given expression.
+ Since all of our sub-expressions are treated as values, we require
+ them to be SSA_NAME's for simplicity.
+ Prior versions of GVNPRE used to use "value handles" here, so that
+ an expression would be VH.11 + VH.10 instead of d_3 + e_6. In
+ either case, the operands are really values (IE we do not expect
+ them to be usable without finding leaders). */
+
+static tree
+get_representative_for (const pre_expr e)
+{
+ tree exprtype;
+ tree name;
+ unsigned int value_id = get_expr_value_id (e);
+
+ switch (e->kind)
+ {
+ case NAME:
+ return PRE_EXPR_NAME (e);
+ case CONSTANT:
+ return PRE_EXPR_CONSTANT (e);
+ case NARY:
+ case REFERENCE:
+ {
+ /* Go through all of the expressions representing this value
+ and pick out an SSA_NAME. */
+ unsigned int i;
+ bitmap_iterator bi;
+ bitmap_set_t exprs = VEC_index (bitmap_set_t, value_expressions,
+ value_id);
+ FOR_EACH_EXPR_ID_IN_SET (exprs, i, bi)
+ {
+ pre_expr rep = expression_for_id (i);
+ if (rep->kind == NAME)
+ return PRE_EXPR_NAME (rep);
+ }
+ }
+ break;
+ }
+ /* If we reached here we couldn't find an SSA_NAME. This can
+ happen when we've discovered a value that has never appeared in
+ the program as set to an SSA_NAME, most likely as the result of
+ phi translation. */
+ if (dump_file)
+ {
+ fprintf (dump_file,
+ "Could not find SSA_NAME representative for expression:");
+ print_pre_expr (dump_file, e);
+ fprintf (dump_file, "\n");
+ }
+
+ exprtype = get_expr_type (e);
+
+ /* Build and insert the assignment of the end result to the temporary
+ that we will return. */
+ if (!pretemp || exprtype != TREE_TYPE (pretemp))
+ {
+ pretemp = create_tmp_var (exprtype, "pretmp");
+ get_var_ann (pretemp);
+ }
+
+ name = make_ssa_name (pretemp, gimple_build_nop ());
+ VN_INFO_GET (name)->value_id = value_id;
+ if (e->kind == CONSTANT)
+ VN_INFO (name)->valnum = PRE_EXPR_CONSTANT (e);
+ else
+ VN_INFO (name)->valnum = name;
+
+ add_to_value (value_id, get_or_alloc_expr_for_name (name));
+ if (dump_file)
+ {
+ fprintf (dump_file, "Created SSA_NAME representative ");
+ print_generic_expr (dump_file, name, 0);
+ fprintf (dump_file, " for expression:");
+ print_pre_expr (dump_file, e);
+ fprintf (dump_file, "\n");
+ }
+
+ return name;
+}
+
+
+
+
+/* Translate EXPR using phis in PHIBLOCK, so that it has the values of
+ the phis in PRED. Return NULL if we can't find a leader for each part
+ of the translated expression. */
+
+static pre_expr
+phi_translate (pre_expr expr, bitmap_set_t set1, bitmap_set_t set2,
+ basic_block pred, basic_block phiblock)
+{
+ pre_expr oldexpr = expr;
+ pre_expr phitrans;
+
+ if (!expr)
+ return NULL;
+
+ if (value_id_constant_p (get_expr_value_id (expr)))
+ return expr;
+
+ phitrans = phi_trans_lookup (expr, pred);
+ if (phitrans)
+ return phitrans;
+
+ switch (expr->kind)
+ {
+ /* Constants contain no values that need translation. */
+ case CONSTANT:
+ return expr;
+
+ case NARY:
+ {
+ unsigned int i;
+ bool changed = false;
+ vn_nary_op_t nary = PRE_EXPR_NARY (expr);
+ struct vn_nary_op_s newnary;
+ /* The NARY structure is only guaranteed to have been
+ allocated to the nary->length operands. */
+ memcpy (&newnary, nary, (sizeof (struct vn_nary_op_s)
+ - sizeof (tree) * (4 - nary->length)));
+
+ for (i = 0; i < newnary.length; i++)
+ {
+ if (TREE_CODE (newnary.op[i]) != SSA_NAME)
+ continue;
+ else
+ {
+ pre_expr leader, result;
+ unsigned int op_val_id = VN_INFO (newnary.op[i])->value_id;
+ leader = find_leader_in_sets (op_val_id, set1, set2);
+ result = phi_translate (leader, set1, set2, pred, phiblock);
+ if (result && result != leader)
+ {
+ tree name = get_representative_for (result);
+ if (!name)
+ return NULL;
+ newnary.op[i] = name;
+ }
+ else if (!result)
+ return NULL;
+
+ changed |= newnary.op[i] != nary->op[i];
+ }
+ }
+ if (changed)
+ {
+ pre_expr constant;
+
+ tree result = vn_nary_op_lookup_pieces (newnary.length,
+ newnary.opcode,
+ newnary.type,
+ newnary.op[0],
+ newnary.op[1],
+ newnary.op[2],
+ newnary.op[3],
+ &nary);
+ unsigned int new_val_id;
+
+ expr = (pre_expr) pool_alloc (pre_expr_pool);
+ expr->kind = NARY;
+ expr->id = 0;
+ if (result && is_gimple_min_invariant (result))
+ return get_or_alloc_expr_for_constant (result);
+
+
+ if (nary)
+ {
+ PRE_EXPR_NARY (expr) = nary;
+ constant = fully_constant_expression (expr);
+ if (constant != expr)
+ return constant;
+
+ new_val_id = nary->value_id;
+ get_or_alloc_expression_id (expr);
+ }
+ else
+ {
+ new_val_id = get_next_value_id ();
+ VEC_safe_grow_cleared (bitmap_set_t, heap,
+ value_expressions,
+ get_max_value_id() + 1);
+ nary = vn_nary_op_insert_pieces (newnary.length,
+ newnary.opcode,
+ newnary.type,
+ newnary.op[0],
+ newnary.op[1],
+ newnary.op[2],
+ newnary.op[3],
+ result, new_val_id);
+ PRE_EXPR_NARY (expr) = nary;
+ constant = fully_constant_expression (expr);
+ if (constant != expr)
+ return constant;
+ get_or_alloc_expression_id (expr);
+ }
+ add_to_value (new_val_id, expr);
+ }
+ phi_trans_add (oldexpr, expr, pred);
+ return expr;
+ }
+ break;
+
+ case REFERENCE:
+ {
+ vn_reference_t ref = PRE_EXPR_REFERENCE (expr);
+ VEC (vn_reference_op_s, heap) *operands = ref->operands;
+ VEC (tree, gc) *vuses = ref->vuses;
+ VEC (tree, gc) *newvuses = vuses;
+ VEC (vn_reference_op_s, heap) *newoperands = NULL;
+ bool changed = false;
+ unsigned int i;
+ vn_reference_op_t operand;
+ vn_reference_t newref;
+
+ for (i = 0; VEC_iterate (vn_reference_op_s, operands, i, operand); i++)
+ {
+ pre_expr opresult;
+ pre_expr leader;
+ tree oldop0 = operand->op0;
+ tree oldop1 = operand->op1;
+ tree oldop2 = operand->op2;
+ tree op0 = oldop0;
+ tree op1 = oldop1;
+ tree op2 = oldop2;
+ tree type = operand->type;
+ vn_reference_op_s newop = *operand;
+
+ if (op0 && TREE_CODE (op0) == SSA_NAME)
+ {
+ unsigned int op_val_id = VN_INFO (op0)->value_id;
+ leader = find_leader_in_sets (op_val_id, set1, set2);
+ opresult = phi_translate (leader, set1, set2, pred, phiblock);
+ if (opresult && opresult != leader)
+ {
+ tree name = get_representative_for (opresult);
+ if (!name)
+ break;
+ op0 = name;
+ }
+ else if (!opresult)
+ break;
+ }
+ changed |= op0 != oldop0;
+
+ if (op1 && TREE_CODE (op1) == SSA_NAME)
+ {
+ unsigned int op_val_id = VN_INFO (op1)->value_id;
+ leader = find_leader_in_sets (op_val_id, set1, set2);
+ opresult = phi_translate (leader, set1, set2, pred, phiblock);
+ if (opresult && opresult != leader)
+ {
+ tree name = get_representative_for (opresult);
+ if (!name)
+ break;
+ op1 = name;
+ }
+ else if (!opresult)
+ break;
+ }
+ changed |= op1 != oldop1;
+ if (op2 && TREE_CODE (op2) == SSA_NAME)
+ {
+ unsigned int op_val_id = VN_INFO (op2)->value_id;
+ leader = find_leader_in_sets (op_val_id, set1, set2);
+ opresult = phi_translate (leader, set1, set2, pred, phiblock);
+ if (opresult && opresult != leader)
+ {
+ tree name = get_representative_for (opresult);
+ if (!name)
+ break;
+ op2 = name;
+ }
+ else if (!opresult)
+ break;
+ }
+ changed |= op2 != oldop2;
+
+ if (!newoperands)
+ newoperands = VEC_copy (vn_reference_op_s, heap, operands);
+ /* We may have changed from an SSA_NAME to a constant */
+ if (newop.opcode == SSA_NAME && TREE_CODE (op0) != SSA_NAME)
+ newop.opcode = TREE_CODE (op0);
+ newop.type = type;
+ newop.op0 = op0;
+ newop.op1 = op1;
+ newop.op2 = op2;
+ VEC_replace (vn_reference_op_s, newoperands, i, &newop);
+ }
+ if (i != VEC_length (vn_reference_op_s, operands))
+ {
+ if (newoperands)
+ VEC_free (vn_reference_op_s, heap, newoperands);
+ return NULL;
+ }
+
+ newvuses = translate_vuses_through_block (vuses, phiblock, pred);
+ changed |= newvuses != vuses;
+
+ if (changed)
+ {
+ unsigned int new_val_id;
+ pre_expr constant;
+
+ tree result = vn_reference_lookup_pieces (newvuses,
+ newoperands,
+ &newref, true);
+ if (newref)
+ VEC_free (vn_reference_op_s, heap, newoperands);
+
+ if (result && is_gimple_min_invariant (result))
+ {
+ gcc_assert (!newoperands);
+ return get_or_alloc_expr_for_constant (result);
+ }
+
+ expr = (pre_expr) pool_alloc (pre_expr_pool);
+ expr->kind = REFERENCE;
+ expr->id = 0;
+
+ if (newref)
+ {
+ PRE_EXPR_REFERENCE (expr) = newref;
+ constant = fully_constant_expression (expr);
+ if (constant != expr)
+ return constant;
+
+ new_val_id = newref->value_id;
+ get_or_alloc_expression_id (expr);
+ }
+ else
+ {
+ new_val_id = get_next_value_id ();
+ VEC_safe_grow_cleared (bitmap_set_t, heap, value_expressions,
+ get_max_value_id() + 1);
+ newref = vn_reference_insert_pieces (newvuses,
+ newoperands,
+ result, new_val_id);
+ newoperands = NULL;
+ PRE_EXPR_REFERENCE (expr) = newref;
+ constant = fully_constant_expression (expr);
+ if (constant != expr)
+ return constant;
+ get_or_alloc_expression_id (expr);
+ }
+ add_to_value (new_val_id, expr);
+ }
+ VEC_free (vn_reference_op_s, heap, newoperands);
+ phi_trans_add (oldexpr, expr, pred);
+ return expr;
+ }
+ break;
+
+ case NAME:
+ {
+ gimple phi = NULL;
+ edge e;
+ gimple def_stmt;
+ tree name = PRE_EXPR_NAME (expr);
+
+ def_stmt = SSA_NAME_DEF_STMT (name);
+ if (gimple_code (def_stmt) == GIMPLE_PHI
+ && gimple_bb (def_stmt) == phiblock)
+ phi = def_stmt;
+ else
+ return expr;
+
+ e = find_edge (pred, gimple_bb (phi));
+ if (e)
+ {
+ tree def = PHI_ARG_DEF (phi, e->dest_idx);
+ pre_expr newexpr;
+
+ if (TREE_CODE (def) == SSA_NAME)
+ def = VN_INFO (def)->valnum;
+
+ /* Handle constant. */
+ if (is_gimple_min_invariant (def))
+ return get_or_alloc_expr_for_constant (def);
+
+ if (TREE_CODE (def) == SSA_NAME && ssa_undefined_value_p (def))
+ return NULL;
+
+ newexpr = get_or_alloc_expr_for_name (def);
+ return newexpr;
+ }
+ }
+ return expr;
+
+ default:
+ gcc_unreachable ();
+ }
+}
+
+/* For each expression in SET, translate the values through phi nodes
+ in PHIBLOCK using edge PHIBLOCK->PRED, and store the resulting
+ expressions in DEST. */
+
+static void
+phi_translate_set (bitmap_set_t dest, bitmap_set_t set, basic_block pred,
+ basic_block phiblock)
+{
+ VEC (pre_expr, heap) *exprs;
+ pre_expr expr;
+ int i;
+
+ if (gimple_seq_empty_p (phi_nodes (phiblock)))
+ {
+ bitmap_set_copy (dest, set);
+ return;
+ }
+
+ exprs = sorted_array_from_bitmap_set (set);
+ for (i = 0; VEC_iterate (pre_expr, exprs, i, expr); i++)
+ {
+ pre_expr translated;
+ translated = phi_translate (expr, set, NULL, pred, phiblock);
+
+ /* Don't add empty translations to the cache */
+ if (translated)
+ phi_trans_add (expr, translated, pred);
+
+ if (translated != NULL)
+ bitmap_value_insert_into_set (dest, translated);
+ }
+ VEC_free (pre_expr, heap, exprs);
+}
+
+/* Find the leader for a value (i.e., the name representing that
+ value) in a given set, and return it. If STMT is non-NULL it
+ makes sure the defining statement for the leader dominates it.
+ Return NULL if no leader is found. */
+
+static pre_expr
+bitmap_find_leader (bitmap_set_t set, unsigned int val, gimple stmt)
+{
+ if (value_id_constant_p (val))
+ {
+ unsigned int i;
+ bitmap_iterator bi;
+ bitmap_set_t exprset = VEC_index (bitmap_set_t, value_expressions, val);
+
+ FOR_EACH_EXPR_ID_IN_SET (exprset, i, bi)
+ {
+ pre_expr expr = expression_for_id (i);
+ if (expr->kind == CONSTANT)
+ return expr;
+ }
+ }
+ if (bitmap_set_contains_value (set, val))
+ {
+ /* Rather than walk the entire bitmap of expressions, and see
+ whether any of them has the value we are looking for, we look
+ at the reverse mapping, which tells us the set of expressions
+ that have a given value (IE value->expressions with that
+ value) and see if any of those expressions are in our set.
+ The number of expressions per value is usually significantly
+ less than the number of expressions in the set. In fact, for
+ large testcases, doing it this way is roughly 5-10x faster
+ than walking the bitmap.
+ If this is somehow a significant lose for some cases, we can
+ choose which set to walk based on which set is smaller. */
+ unsigned int i;
+ bitmap_iterator bi;
+ bitmap_set_t exprset = VEC_index (bitmap_set_t, value_expressions, val);
+
+ EXECUTE_IF_AND_IN_BITMAP (exprset->expressions,
+ set->expressions, 0, i, bi)
+ {
+ pre_expr val = expression_for_id (i);
+ /* At the point where stmt is not null, there should always
+ be an SSA_NAME first in the list of expressions. */
+ if (stmt)
+ {
+ gimple def_stmt = SSA_NAME_DEF_STMT (PRE_EXPR_NAME (val));
+ if (gimple_code (def_stmt) != GIMPLE_PHI
+ && gimple_bb (def_stmt) == gimple_bb (stmt)
+ && gimple_uid (def_stmt) >= gimple_uid (stmt))
+ continue;
+ }
+ return val;
+ }
+ }
+ return NULL;
+}
+
+/* Determine if EXPR, a memory expression, is ANTIC_IN at the top of
+ BLOCK by seeing if it is not killed in the block. Note that we are
+ only determining whether there is a store that kills it. Because
+ of the order in which clean iterates over values, we are guaranteed
+ that altered operands will have caused us to be eliminated from the
+ ANTIC_IN set already. */
+
+static bool
+value_dies_in_block_x (pre_expr expr, basic_block block)
+{
+ int i;
+ tree vuse;
+ VEC (tree, gc) *vuses = PRE_EXPR_REFERENCE (expr)->vuses;
+
+ /* Conservatively, a value dies if it's vuses are defined in this
+ block, unless they come from phi nodes (which are merge operations,
+ rather than stores. */
+ for (i = 0; VEC_iterate (tree, vuses, i, vuse); i++)
+ {
+ gimple def = SSA_NAME_DEF_STMT (vuse);
+
+ if (gimple_bb (def) != block)
+ continue;
+ if (gimple_code (def) == GIMPLE_PHI)
+ continue;
+ return true;
+ }
+ return false;
+}
+
+
+#define union_contains_value(SET1, SET2, VAL) \
+ (bitmap_set_contains_value ((SET1), (VAL)) \
+ || ((SET2) && bitmap_set_contains_value ((SET2), (VAL))))
+
+/* Determine if vn_reference_op_t VRO is legal in SET1 U SET2.
+ */
+static bool
+vro_valid_in_sets (bitmap_set_t set1, bitmap_set_t set2,
+ vn_reference_op_t vro)
+{
+ if (vro->op0 && TREE_CODE (vro->op0) == SSA_NAME)
+ {
+ struct pre_expr_d temp;
+ temp.kind = NAME;
+ temp.id = 0;
+ PRE_EXPR_NAME (&temp) = vro->op0;
+ temp.id = lookup_expression_id (&temp);
+ if (temp.id == 0)
+ return false;
+ if (!union_contains_value (set1, set2,
+ get_expr_value_id (&temp)))
+ return false;
+ }
+ if (vro->op1 && TREE_CODE (vro->op1) == SSA_NAME)
+ {
+ struct pre_expr_d temp;
+ temp.kind = NAME;
+ temp.id = 0;
+ PRE_EXPR_NAME (&temp) = vro->op1;
+ temp.id = lookup_expression_id (&temp);
+ if (temp.id == 0)
+ return false;
+ if (!union_contains_value (set1, set2,
+ get_expr_value_id (&temp)))
+ return false;
+ }
+
+ if (vro->op2 && TREE_CODE (vro->op2) == SSA_NAME)
+ {
+ struct pre_expr_d temp;
+ temp.kind = NAME;
+ temp.id = 0;
+ PRE_EXPR_NAME (&temp) = vro->op2;
+ temp.id = lookup_expression_id (&temp);
+ if (temp.id == 0)
+ return false;
+ if (!union_contains_value (set1, set2,
+ get_expr_value_id (&temp)))
+ return false;
+ }
+
+ return true;
+}
+
+/* Determine if the expression EXPR is valid in SET1 U SET2.
+ ONLY SET2 CAN BE NULL.
+ This means that we have a leader for each part of the expression
+ (if it consists of values), or the expression is an SSA_NAME.
+ For loads/calls, we also see if the vuses are killed in this block.
+*/
+
+static bool
+valid_in_sets (bitmap_set_t set1, bitmap_set_t set2, pre_expr expr,
+ basic_block block)
+{
+ switch (expr->kind)
+ {
+ case NAME:
+ return bitmap_set_contains_expr (AVAIL_OUT (block), expr);
+ case NARY:
+ {
+ unsigned int i;
+ vn_nary_op_t nary = PRE_EXPR_NARY (expr);
+ for (i = 0; i < nary->length; i++)
+ {
+ if (TREE_CODE (nary->op[i]) == SSA_NAME)
+ {
+ struct pre_expr_d temp;
+ temp.kind = NAME;
+ temp.id = 0;
+ PRE_EXPR_NAME (&temp) = nary->op[i];
+ temp.id = lookup_expression_id (&temp);
+ if (temp.id == 0)
+ return false;
+ if (!union_contains_value (set1, set2,
+ get_expr_value_id (&temp)))
+ return false;
+ }
+ }
+ return true;
+ }
+ break;
+ case REFERENCE:
+ {
+ vn_reference_t ref = PRE_EXPR_REFERENCE (expr);
+ vn_reference_op_t vro;
+ unsigned int i;
+
+ for (i = 0; VEC_iterate (vn_reference_op_s, ref->operands, i, vro); i++)
+ {
+ if (!vro_valid_in_sets (set1, set2, vro))
+ return false;
+ }
+ return !value_dies_in_block_x (expr, block);
+ }
+ default:
+ gcc_unreachable ();
+ }
+}
+
+/* Clean the set of expressions that are no longer valid in SET1 or
+ SET2. This means expressions that are made up of values we have no
+ leaders for in SET1 or SET2. This version is used for partial
+ anticipation, which means it is not valid in either ANTIC_IN or
+ PA_IN. */
+
+static void
+dependent_clean (bitmap_set_t set1, bitmap_set_t set2, basic_block block)
+{
+ VEC (pre_expr, heap) *exprs = sorted_array_from_bitmap_set (set1);
+ pre_expr expr;
+ int i;
+
+ for (i = 0; VEC_iterate (pre_expr, exprs, i, expr); i++)
+ {
+ if (!valid_in_sets (set1, set2, expr, block))
+ bitmap_remove_from_set (set1, expr);
+ }
+ VEC_free (pre_expr, heap, exprs);
+}
+
+/* Clean the set of expressions that are no longer valid in SET. This
+ means expressions that are made up of values we have no leaders for
+ in SET. */
+
+static void
+clean (bitmap_set_t set, basic_block block)
+{
+ VEC (pre_expr, heap) *exprs = sorted_array_from_bitmap_set (set);
+ pre_expr expr;
+ int i;
+
+ for (i = 0; VEC_iterate (pre_expr, exprs, i, expr); i++)
+ {
+ if (!valid_in_sets (set, NULL, expr, block))
+ bitmap_remove_from_set (set, expr);
+ }
+ VEC_free (pre_expr, heap, exprs);
+}
+
+static sbitmap has_abnormal_preds;
+
+/* List of blocks that may have changed during ANTIC computation and
+ thus need to be iterated over. */
+
+static sbitmap changed_blocks;
+
+/* Decide whether to defer a block for a later iteration, or PHI
+ translate SOURCE to DEST using phis in PHIBLOCK. Return false if we
+ should defer the block, and true if we processed it. */
+
+static bool
+defer_or_phi_translate_block (bitmap_set_t dest, bitmap_set_t source,
+ basic_block block, basic_block phiblock)
+{
+ if (!BB_VISITED (phiblock))
+ {
+ SET_BIT (changed_blocks, block->index);
+ BB_VISITED (block) = 0;
+ BB_DEFERRED (block) = 1;
+ return false;
+ }
+ else
+ phi_translate_set (dest, source, block, phiblock);
+ return true;
+}
+
+/* Compute the ANTIC set for BLOCK.
+
+ If succs(BLOCK) > 1 then
+ ANTIC_OUT[BLOCK] = intersection of ANTIC_IN[b] for all succ(BLOCK)
+ else if succs(BLOCK) == 1 then
+ ANTIC_OUT[BLOCK] = phi_translate (ANTIC_IN[succ(BLOCK)])
+
+ ANTIC_IN[BLOCK] = clean(ANTIC_OUT[BLOCK] U EXP_GEN[BLOCK] - TMP_GEN[BLOCK])
+*/
+
+static bool
+compute_antic_aux (basic_block block, bool block_has_abnormal_pred_edge)
+{
+ bool changed = false;
+ bitmap_set_t S, old, ANTIC_OUT;
+ bitmap_iterator bi;
+ unsigned int bii;
+ edge e;
+ edge_iterator ei;
+
+ old = ANTIC_OUT = S = NULL;
+ BB_VISITED (block) = 1;
+
+ /* If any edges from predecessors are abnormal, antic_in is empty,
+ so do nothing. */
+ if (block_has_abnormal_pred_edge)
+ goto maybe_dump_sets;
+
+ old = ANTIC_IN (block);
+ ANTIC_OUT = bitmap_set_new ();
+
+ /* If the block has no successors, ANTIC_OUT is empty. */
+ if (EDGE_COUNT (block->succs) == 0)
+ ;
+ /* If we have one successor, we could have some phi nodes to
+ translate through. */
+ else if (single_succ_p (block))
+ {
+ basic_block succ_bb = single_succ (block);
+
+ /* We trade iterations of the dataflow equations for having to
+ phi translate the maximal set, which is incredibly slow
+ (since the maximal set often has 300+ members, even when you
+ have a small number of blocks).
+ Basically, we defer the computation of ANTIC for this block
+ until we have processed it's successor, which will inevitably
+ have a *much* smaller set of values to phi translate once
+ clean has been run on it.
+ The cost of doing this is that we technically perform more
+ iterations, however, they are lower cost iterations.
+
+ Timings for PRE on tramp3d-v4:
+ without maximal set fix: 11 seconds
+ with maximal set fix/without deferring: 26 seconds
+ with maximal set fix/with deferring: 11 seconds
+ */
+
+ if (!defer_or_phi_translate_block (ANTIC_OUT, ANTIC_IN (succ_bb),
+ block, succ_bb))
+ {
+ changed = true;
+ goto maybe_dump_sets;
+ }
+ }
+ /* If we have multiple successors, we take the intersection of all of
+ them. Note that in the case of loop exit phi nodes, we may have
+ phis to translate through. */
+ else
+ {
+ VEC(basic_block, heap) * worklist;
+ size_t i;
+ basic_block bprime, first = NULL;
+
+ worklist = VEC_alloc (basic_block, heap, EDGE_COUNT (block->succs));
+ FOR_EACH_EDGE (e, ei, block->succs)
+ {
+ if (!first
+ && BB_VISITED (e->dest))
+ first = e->dest;
+ else if (BB_VISITED (e->dest))
+ VEC_quick_push (basic_block, worklist, e->dest);
+ }
+
+ /* Of multiple successors we have to have visited one already. */
+ if (!first)
+ {
+ SET_BIT (changed_blocks, block->index);
+ BB_VISITED (block) = 0;
+ BB_DEFERRED (block) = 1;
+ changed = true;
+ VEC_free (basic_block, heap, worklist);
+ goto maybe_dump_sets;
+ }
+
+ if (!gimple_seq_empty_p (phi_nodes (first)))
+ phi_translate_set (ANTIC_OUT, ANTIC_IN (first), block, first);
+ else
+ bitmap_set_copy (ANTIC_OUT, ANTIC_IN (first));
+
+ for (i = 0; VEC_iterate (basic_block, worklist, i, bprime); i++)
+ {
+ if (!gimple_seq_empty_p (phi_nodes (bprime)))
+ {
+ bitmap_set_t tmp = bitmap_set_new ();
+ phi_translate_set (tmp, ANTIC_IN (bprime), block, bprime);
+ bitmap_set_and (ANTIC_OUT, tmp);
+ bitmap_set_free (tmp);
+ }
+ else
+ bitmap_set_and (ANTIC_OUT, ANTIC_IN (bprime));
+ }
+ VEC_free (basic_block, heap, worklist);
+ }
+
+ /* Generate ANTIC_OUT - TMP_GEN. */
+ S = bitmap_set_subtract (ANTIC_OUT, TMP_GEN (block));
+
+ /* Start ANTIC_IN with EXP_GEN - TMP_GEN. */
+ ANTIC_IN (block) = bitmap_set_subtract (EXP_GEN (block),
+ TMP_GEN (block));
+
+ /* Then union in the ANTIC_OUT - TMP_GEN values,
+ to get ANTIC_OUT U EXP_GEN - TMP_GEN */
+ FOR_EACH_EXPR_ID_IN_SET (S, bii, bi)
+ bitmap_value_insert_into_set (ANTIC_IN (block),
+ expression_for_id (bii));
+
+ clean (ANTIC_IN (block), block);
+
+ /* !old->expressions can happen when we deferred a block. */
+ if (!old->expressions || !bitmap_set_equal (old, ANTIC_IN (block)))
+ {
+ changed = true;
+ SET_BIT (changed_blocks, block->index);
+ FOR_EACH_EDGE (e, ei, block->preds)
+ SET_BIT (changed_blocks, e->src->index);
+ }
+ else
+ RESET_BIT (changed_blocks, block->index);
+
+ maybe_dump_sets:
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ if (!BB_DEFERRED (block) || BB_VISITED (block))
+ {
+ if (ANTIC_OUT)
+ print_bitmap_set (dump_file, ANTIC_OUT, "ANTIC_OUT", block->index);
+
+ print_bitmap_set (dump_file, ANTIC_IN (block), "ANTIC_IN",
+ block->index);
+
+ if (S)
+ print_bitmap_set (dump_file, S, "S", block->index);
+ }
+ else
+ {
+ fprintf (dump_file,
+ "Block %d was deferred for a future iteration.\n",
+ block->index);
+ }
+ }
+ if (old)
+ bitmap_set_free (old);
+ if (S)
+ bitmap_set_free (S);
+ if (ANTIC_OUT)
+ bitmap_set_free (ANTIC_OUT);
+ return changed;
+}
+
+/* Compute PARTIAL_ANTIC for BLOCK.
+
+ If succs(BLOCK) > 1 then
+ PA_OUT[BLOCK] = value wise union of PA_IN[b] + all ANTIC_IN not
+ in ANTIC_OUT for all succ(BLOCK)
+ else if succs(BLOCK) == 1 then
+ PA_OUT[BLOCK] = phi_translate (PA_IN[succ(BLOCK)])
+
+ PA_IN[BLOCK] = dependent_clean(PA_OUT[BLOCK] - TMP_GEN[BLOCK]
+ - ANTIC_IN[BLOCK])
+
+*/
+static bool
+compute_partial_antic_aux (basic_block block,
+ bool block_has_abnormal_pred_edge)
+{
+ bool changed = false;
+ bitmap_set_t old_PA_IN;
+ bitmap_set_t PA_OUT;
+ edge e;
+ edge_iterator ei;
+ unsigned long max_pa = PARAM_VALUE (PARAM_MAX_PARTIAL_ANTIC_LENGTH);
+
+ old_PA_IN = PA_OUT = NULL;
+
+ /* If any edges from predecessors are abnormal, antic_in is empty,
+ so do nothing. */
+ if (block_has_abnormal_pred_edge)
+ goto maybe_dump_sets;
+
+ /* If there are too many partially anticipatable values in the
+ block, phi_translate_set can take an exponential time: stop
+ before the translation starts. */
+ if (max_pa
+ && single_succ_p (block)
+ && bitmap_count_bits (PA_IN (single_succ (block))->values) > max_pa)
+ goto maybe_dump_sets;
+
+ old_PA_IN = PA_IN (block);
+ PA_OUT = bitmap_set_new ();
+
+ /* If the block has no successors, ANTIC_OUT is empty. */
+ if (EDGE_COUNT (block->succs) == 0)
+ ;
+ /* If we have one successor, we could have some phi nodes to
+ translate through. Note that we can't phi translate across DFS
+ back edges in partial antic, because it uses a union operation on
+ the successors. For recurrences like IV's, we will end up
+ generating a new value in the set on each go around (i + 3 (VH.1)
+ VH.1 + 1 (VH.2), VH.2 + 1 (VH.3), etc), forever. */
+ else if (single_succ_p (block))
+ {
+ basic_block succ = single_succ (block);
+ if (!(single_succ_edge (block)->flags & EDGE_DFS_BACK))
+ phi_translate_set (PA_OUT, PA_IN (succ), block, succ);
+ }
+ /* If we have multiple successors, we take the union of all of
+ them. */
+ else
+ {
+ VEC(basic_block, heap) * worklist;
+ size_t i;
+ basic_block bprime;
+
+ worklist = VEC_alloc (basic_block, heap, EDGE_COUNT (block->succs));
+ FOR_EACH_EDGE (e, ei, block->succs)
+ {
+ if (e->flags & EDGE_DFS_BACK)
+ continue;
+ VEC_quick_push (basic_block, worklist, e->dest);
+ }
+ if (VEC_length (basic_block, worklist) > 0)
+ {
+ for (i = 0; VEC_iterate (basic_block, worklist, i, bprime); i++)
+ {
+ unsigned int i;
+ bitmap_iterator bi;
+
+ FOR_EACH_EXPR_ID_IN_SET (ANTIC_IN (bprime), i, bi)
+ bitmap_value_insert_into_set (PA_OUT,
+ expression_for_id (i));
+ if (!gimple_seq_empty_p (phi_nodes (bprime)))
+ {
+ bitmap_set_t pa_in = bitmap_set_new ();
+ phi_translate_set (pa_in, PA_IN (bprime), block, bprime);
+ FOR_EACH_EXPR_ID_IN_SET (pa_in, i, bi)
+ bitmap_value_insert_into_set (PA_OUT,
+ expression_for_id (i));
+ bitmap_set_free (pa_in);
+ }
+ else
+ FOR_EACH_EXPR_ID_IN_SET (PA_IN (bprime), i, bi)
+ bitmap_value_insert_into_set (PA_OUT,
+ expression_for_id (i));
+ }
+ }
+ VEC_free (basic_block, heap, worklist);
+ }
+
+ /* PA_IN starts with PA_OUT - TMP_GEN.
+ Then we subtract things from ANTIC_IN. */
+ PA_IN (block) = bitmap_set_subtract (PA_OUT, TMP_GEN (block));
+
+ /* For partial antic, we want to put back in the phi results, since
+ we will properly avoid making them partially antic over backedges. */
+ bitmap_ior_into (PA_IN (block)->values, PHI_GEN (block)->values);
+ bitmap_ior_into (PA_IN (block)->expressions, PHI_GEN (block)->expressions);
+
+ /* PA_IN[block] = PA_IN[block] - ANTIC_IN[block] */
+ bitmap_set_subtract_values (PA_IN (block), ANTIC_IN (block));
+
+ dependent_clean (PA_IN (block), ANTIC_IN (block), block);
+
+ if (!bitmap_set_equal (old_PA_IN, PA_IN (block)))
+ {
+ changed = true;
+ SET_BIT (changed_blocks, block->index);
+ FOR_EACH_EDGE (e, ei, block->preds)
+ SET_BIT (changed_blocks, e->src->index);
+ }
+ else
+ RESET_BIT (changed_blocks, block->index);
+
+ maybe_dump_sets:
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ if (PA_OUT)
+ print_bitmap_set (dump_file, PA_OUT, "PA_OUT", block->index);
+
+ print_bitmap_set (dump_file, PA_IN (block), "PA_IN", block->index);
+ }
+ if (old_PA_IN)
+ bitmap_set_free (old_PA_IN);
+ if (PA_OUT)
+ bitmap_set_free (PA_OUT);
+ return changed;
+}
+
+/* Compute ANTIC and partial ANTIC sets. */
+
+static void
+compute_antic (void)
+{
+ bool changed = true;
+ int num_iterations = 0;
+ basic_block block;
+ int i;
+
+ /* If any predecessor edges are abnormal, we punt, so antic_in is empty.
+ We pre-build the map of blocks with incoming abnormal edges here. */
+ has_abnormal_preds = sbitmap_alloc (last_basic_block);
+ sbitmap_zero (has_abnormal_preds);
+
+ FOR_EACH_BB (block)
+ {
+ edge_iterator ei;
+ edge e;
+
+ FOR_EACH_EDGE (e, ei, block->preds)
+ {
+ e->flags &= ~EDGE_DFS_BACK;
+ if (e->flags & EDGE_ABNORMAL)
+ {
+ SET_BIT (has_abnormal_preds, block->index);
+ break;
+ }
+ }
+
+ BB_VISITED (block) = 0;
+ BB_DEFERRED (block) = 0;
+ /* While we are here, give empty ANTIC_IN sets to each block. */
+ ANTIC_IN (block) = bitmap_set_new ();
+ PA_IN (block) = bitmap_set_new ();
+ }
+
+ /* At the exit block we anticipate nothing. */
+ ANTIC_IN (EXIT_BLOCK_PTR) = bitmap_set_new ();
+ BB_VISITED (EXIT_BLOCK_PTR) = 1;
+ PA_IN (EXIT_BLOCK_PTR) = bitmap_set_new ();
+
+ changed_blocks = sbitmap_alloc (last_basic_block + 1);
+ sbitmap_ones (changed_blocks);
+ while (changed)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Starting iteration %d\n", num_iterations);
+ num_iterations++;
+ changed = false;
+ for (i = 0; i < n_basic_blocks - NUM_FIXED_BLOCKS; i++)
+ {
+ if (TEST_BIT (changed_blocks, postorder[i]))
+ {
+ basic_block block = BASIC_BLOCK (postorder[i]);
+ changed |= compute_antic_aux (block,
+ TEST_BIT (has_abnormal_preds,
+ block->index));
+ }
+ }
+#ifdef ENABLE_CHECKING
+ /* Theoretically possible, but *highly* unlikely. */
+ gcc_assert (num_iterations < 500);
+#endif
+ }
+
+ statistics_histogram_event (cfun, "compute_antic iterations",
+ num_iterations);
+
+ if (do_partial_partial)
+ {
+ sbitmap_ones (changed_blocks);
+ mark_dfs_back_edges ();
+ num_iterations = 0;
+ changed = true;
+ while (changed)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Starting iteration %d\n", num_iterations);
+ num_iterations++;
+ changed = false;
+ for (i = 0; i < n_basic_blocks - NUM_FIXED_BLOCKS; i++)
+ {
+ if (TEST_BIT (changed_blocks, postorder[i]))
+ {
+ basic_block block = BASIC_BLOCK (postorder[i]);
+ changed
+ |= compute_partial_antic_aux (block,
+ TEST_BIT (has_abnormal_preds,
+ block->index));
+ }
+ }
+#ifdef ENABLE_CHECKING
+ /* Theoretically possible, but *highly* unlikely. */
+ gcc_assert (num_iterations < 500);
+#endif
+ }
+ statistics_histogram_event (cfun, "compute_partial_antic iterations",
+ num_iterations);
+ }
+ sbitmap_free (has_abnormal_preds);
+ sbitmap_free (changed_blocks);
+}
+
+/* Return true if we can value number the call in STMT. This is true
+ if we have a pure or constant call. */
+
+static bool
+can_value_number_call (gimple stmt)
+{
+ if (gimple_call_flags (stmt) & (ECF_PURE | ECF_CONST))
+ return true;
+ return false;
+}
+
+/* Return true if OP is an exception handler related operation, such as
+ FILTER_EXPR or EXC_PTR_EXPR. */
+
+static bool
+is_exception_related (gimple stmt)
+{
+ return (is_gimple_assign (stmt)
+ && (gimple_assign_rhs_code (stmt) == FILTER_EXPR
+ || gimple_assign_rhs_code (stmt) == EXC_PTR_EXPR));
+}
+
+/* Return true if OP is a tree which we can perform PRE on
+ on. This may not match the operations we can value number, but in
+ a perfect world would. */
+
+static bool
+can_PRE_operation (tree op)
+{
+ return UNARY_CLASS_P (op)
+ || BINARY_CLASS_P (op)
+ || COMPARISON_CLASS_P (op)
+ || TREE_CODE (op) == INDIRECT_REF
+ || TREE_CODE (op) == COMPONENT_REF
+ || TREE_CODE (op) == VIEW_CONVERT_EXPR
+ || TREE_CODE (op) == CALL_EXPR
+ || TREE_CODE (op) == ARRAY_REF;
+}
+
+
+/* Inserted expressions are placed onto this worklist, which is used
+ for performing quick dead code elimination of insertions we made
+ that didn't turn out to be necessary. */
+static VEC(gimple,heap) *inserted_exprs;
+
+/* Pool allocated fake store expressions are placed onto this
+ worklist, which, after performing dead code elimination, is walked
+ to see which expressions need to be put into GC'able memory */
+static VEC(gimple, heap) *need_creation;
+
+/* The actual worker for create_component_ref_by_pieces. */
+
+static tree
+create_component_ref_by_pieces_1 (basic_block block, vn_reference_t ref,
+ unsigned int *operand, gimple_seq *stmts,
+ gimple domstmt)
+{
+ vn_reference_op_t currop = VEC_index (vn_reference_op_s, ref->operands,
+ *operand);
+ tree genop;
+ ++*operand;
+ switch (currop->opcode)
+ {
+ case CALL_EXPR:
+ {
+ tree folded, sc = currop->op1;
+ unsigned int nargs = 0;
+ tree *args = XNEWVEC (tree, VEC_length (vn_reference_op_s,
+ ref->operands) - 1);
+ while (*operand < VEC_length (vn_reference_op_s, ref->operands))
+ {
+ args[nargs] = create_component_ref_by_pieces_1 (block, ref,
+ operand, stmts,
+ domstmt);
+ nargs++;
+ }
+ folded = build_call_array (currop->type,
+ TREE_CODE (currop->op0) == FUNCTION_DECL
+ ? build_fold_addr_expr (currop->op0)
+ : currop->op0,
+ nargs, args);
+ free (args);
+ if (sc)
+ {
+ pre_expr scexpr = get_or_alloc_expr_for (sc);
+ sc = find_or_generate_expression (block, scexpr, stmts, domstmt);
+ if (!sc)
+ return NULL_TREE;
+ CALL_EXPR_STATIC_CHAIN (folded) = sc;
+ }
+ return folded;
+ }
+ break;
+ case ADDR_EXPR:
+ if (currop->op0)
+ {
+ gcc_assert (is_gimple_min_invariant (currop->op0));
+ return currop->op0;
+ }
+ /* Fallthrough. */
+ case REALPART_EXPR:
+ case IMAGPART_EXPR:
+ case VIEW_CONVERT_EXPR:
+ {
+ tree folded;
+ tree genop0 = create_component_ref_by_pieces_1 (block, ref,
+ operand,
+ stmts, domstmt);
+ if (!genop0)
+ return NULL_TREE;
+ folded = fold_build1 (currop->opcode, currop->type,
+ genop0);
+ return folded;
+ }
+ break;
+ case ALIGN_INDIRECT_REF:
+ case MISALIGNED_INDIRECT_REF:
+ case INDIRECT_REF:
+ {
+ tree folded;
+ tree genop1 = create_component_ref_by_pieces_1 (block, ref,
+ operand,
+ stmts, domstmt);
+ if (!genop1)
+ return NULL_TREE;
+ genop1 = fold_convert (build_pointer_type (currop->type),
+ genop1);
+
+ if (currop->opcode == MISALIGNED_INDIRECT_REF)
+ folded = fold_build2 (currop->opcode, currop->type,
+ genop1, currop->op1);
+ else
+ folded = fold_build1 (currop->opcode, currop->type,
+ genop1);
+ return folded;
+ }
+ break;
+ case BIT_FIELD_REF:
+ {
+ tree folded;
+ tree genop0 = create_component_ref_by_pieces_1 (block, ref, operand,
+ stmts, domstmt);
+ pre_expr op1expr = get_or_alloc_expr_for (currop->op0);
+ pre_expr op2expr = get_or_alloc_expr_for (currop->op1);
+ tree genop1;
+ tree genop2;
+
+ if (!genop0)
+ return NULL_TREE;
+ genop1 = find_or_generate_expression (block, op1expr, stmts, domstmt);
+ if (!genop1)
+ return NULL_TREE;
+ genop2 = find_or_generate_expression (block, op2expr, stmts, domstmt);
+ if (!genop2)
+ return NULL_TREE;
+ folded = fold_build3 (BIT_FIELD_REF, currop->type, genop0, genop1,
+ genop2);
+ return folded;
+ }
+
+ /* For array ref vn_reference_op's, operand 1 of the array ref
+ is op0 of the reference op and operand 3 of the array ref is
+ op1. */
+ case ARRAY_RANGE_REF:
+ case ARRAY_REF:
+ {
+ tree genop0;
+ tree genop1 = currop->op0;
+ pre_expr op1expr;
+ tree genop2 = currop->op1;
+ pre_expr op2expr;
+ tree genop3;
+ genop0 = create_component_ref_by_pieces_1 (block, ref, operand,
+ stmts, domstmt);
+ if (!genop0)
+ return NULL_TREE;
+ op1expr = get_or_alloc_expr_for (genop1);
+ genop1 = find_or_generate_expression (block, op1expr, stmts, domstmt);
+ if (!genop1)
+ return NULL_TREE;
+ if (genop2)
+ {
+ op2expr = get_or_alloc_expr_for (genop2);
+ genop2 = find_or_generate_expression (block, op2expr, stmts,
+ domstmt);
+ if (!genop2)
+ return NULL_TREE;
+ }
+
+ genop3 = currop->op2;
+ return build4 (currop->opcode, currop->type, genop0, genop1,
+ genop2, genop3);
+ }
+ case COMPONENT_REF:
+ {
+ tree op0;
+ tree op1;
+ tree genop2 = currop->op1;
+ pre_expr op2expr;
+ op0 = create_component_ref_by_pieces_1 (block, ref, operand,
+ stmts, domstmt);
+ if (!op0)
+ return NULL_TREE;
+ /* op1 should be a FIELD_DECL, which are represented by
+ themselves. */
+ op1 = currop->op0;
+ if (genop2)
+ {
+ op2expr = get_or_alloc_expr_for (genop2);
+ genop2 = find_or_generate_expression (block, op2expr, stmts,
+ domstmt);
+ if (!genop2)
+ return NULL_TREE;
+ }
+
+ return fold_build3 (COMPONENT_REF, TREE_TYPE (op1), op0, op1,
+ genop2);
+ }
+ break;
+ case SSA_NAME:
+ {
+ pre_expr op0expr = get_or_alloc_expr_for (currop->op0);
+ genop = find_or_generate_expression (block, op0expr, stmts, domstmt);
+ return genop;
+ }
+ case STRING_CST:
+ case INTEGER_CST:
+ case COMPLEX_CST:
+ case VECTOR_CST:
+ case REAL_CST:
+ case CONSTRUCTOR:
+ case VAR_DECL:
+ case PARM_DECL:
+ case CONST_DECL:
+ case RESULT_DECL:
+ case FUNCTION_DECL:
+ return currop->op0;
+
+ default:
+ gcc_unreachable ();
+ }
+}
+
+/* For COMPONENT_REF's and ARRAY_REF's, we can't have any intermediates for the
+ COMPONENT_REF or INDIRECT_REF or ARRAY_REF portion, because we'd end up with
+ trying to rename aggregates into ssa form directly, which is a no no.
+
+ Thus, this routine doesn't create temporaries, it just builds a
+ single access expression for the array, calling
+ find_or_generate_expression to build the innermost pieces.
+
+ This function is a subroutine of create_expression_by_pieces, and
+ should not be called on it's own unless you really know what you
+ are doing. */
+
+static tree
+create_component_ref_by_pieces (basic_block block, vn_reference_t ref,
+ gimple_seq *stmts, gimple domstmt)
+{
+ unsigned int op = 0;
+ return create_component_ref_by_pieces_1 (block, ref, &op, stmts, domstmt);
+}
+
+/* Find a leader for an expression, or generate one using
+ create_expression_by_pieces if it's ANTIC but
+ complex.
+ BLOCK is the basic_block we are looking for leaders in.
+ EXPR is the expression to find a leader or generate for.
+ STMTS is the statement list to put the inserted expressions on.
+ Returns the SSA_NAME of the LHS of the generated expression or the
+ leader.
+ DOMSTMT if non-NULL is a statement that should be dominated by
+ all uses in the generated expression. If DOMSTMT is non-NULL this
+ routine can fail and return NULL_TREE. Otherwise it will assert
+ on failure. */
+
+static tree
+find_or_generate_expression (basic_block block, pre_expr expr,
+ gimple_seq *stmts, gimple domstmt)
+{
+ pre_expr leader = bitmap_find_leader (AVAIL_OUT (block),
+ get_expr_value_id (expr), domstmt);
+ tree genop = NULL;
+ if (leader)
+ {
+ if (leader->kind == NAME)
+ genop = PRE_EXPR_NAME (leader);
+ else if (leader->kind == CONSTANT)
+ genop = PRE_EXPR_CONSTANT (leader);
+ }
+
+ /* If it's still NULL, it must be a complex expression, so generate
+ it recursively. Not so for FRE though. */
+ if (genop == NULL
+ && !in_fre)
+ {
+ bitmap_set_t exprset;
+ unsigned int lookfor = get_expr_value_id (expr);
+ bool handled = false;
+ bitmap_iterator bi;
+ unsigned int i;
+
+ exprset = VEC_index (bitmap_set_t, value_expressions, lookfor);
+ FOR_EACH_EXPR_ID_IN_SET (exprset, i, bi)
+ {
+ pre_expr temp = expression_for_id (i);
+ if (temp->kind != NAME)
+ {
+ handled = true;
+ genop = create_expression_by_pieces (block, temp, stmts,
+ domstmt,
+ get_expr_type (expr));
+ break;
+ }
+ }
+ if (!handled && domstmt)
+ return NULL_TREE;
+
+ gcc_assert (handled);
+ }
+ return genop;
+}
+
+#define NECESSARY GF_PLF_1
+
+/* Create an expression in pieces, so that we can handle very complex
+ expressions that may be ANTIC, but not necessary GIMPLE.
+ BLOCK is the basic block the expression will be inserted into,
+ EXPR is the expression to insert (in value form)
+ STMTS is a statement list to append the necessary insertions into.
+
+ This function will die if we hit some value that shouldn't be
+ ANTIC but is (IE there is no leader for it, or its components).
+ This function may also generate expressions that are themselves
+ partially or fully redundant. Those that are will be either made
+ fully redundant during the next iteration of insert (for partially
+ redundant ones), or eliminated by eliminate (for fully redundant
+ ones).
+
+ If DOMSTMT is non-NULL then we make sure that all uses in the
+ expressions dominate that statement. In this case the function
+ can return NULL_TREE to signal failure. */
+
+static tree
+create_expression_by_pieces (basic_block block, pre_expr expr,
+ gimple_seq *stmts, gimple domstmt, tree type)
+{
+ tree temp, name;
+ tree folded, newexpr;
+ gimple_seq forced_stmts;
+ unsigned int value_id;
+ gimple_stmt_iterator gsi;
+ tree exprtype = type ? type : get_expr_type (expr);
+ pre_expr nameexpr;
+ gimple newstmt;
+
+ switch (expr->kind)
+ {
+ /* We may hit the NAME/CONSTANT case if we have to convert types
+ that value numbering saw through. */
+ case NAME:
+ folded = PRE_EXPR_NAME (expr);
+ break;
+ case CONSTANT:
+ folded = PRE_EXPR_CONSTANT (expr);
+ break;
+ case REFERENCE:
+ {
+ vn_reference_t ref = PRE_EXPR_REFERENCE (expr);
+ folded = create_component_ref_by_pieces (block, ref, stmts, domstmt);
+ }
+ break;
+ case NARY:
+ {
+ vn_nary_op_t nary = PRE_EXPR_NARY (expr);
+ switch (nary->length)
+ {
+ case 2:
+ {
+ pre_expr op1 = get_or_alloc_expr_for (nary->op[0]);
+ pre_expr op2 = get_or_alloc_expr_for (nary->op[1]);
+ tree genop1 = find_or_generate_expression (block, op1,
+ stmts, domstmt);
+ tree genop2 = find_or_generate_expression (block, op2,
+ stmts, domstmt);
+ if (!genop1 || !genop2)
+ return NULL_TREE;
+ genop1 = fold_convert (TREE_TYPE (nary->op[0]),
+ genop1);
+ /* Ensure op2 is a sizetype for POINTER_PLUS_EXPR. It
+ may be a constant with the wrong type. */
+ if (nary->opcode == POINTER_PLUS_EXPR)
+ genop2 = fold_convert (sizetype, genop2);
+ else
+ genop2 = fold_convert (TREE_TYPE (nary->op[1]), genop2);
+
+ folded = fold_build2 (nary->opcode, nary->type,
+ genop1, genop2);
+ }
+ break;
+ case 1:
+ {
+ pre_expr op1 = get_or_alloc_expr_for (nary->op[0]);
+ tree genop1 = find_or_generate_expression (block, op1,
+ stmts, domstmt);
+ if (!genop1)
+ return NULL_TREE;
+ genop1 = fold_convert (TREE_TYPE (nary->op[0]), genop1);
+
+ folded = fold_build1 (nary->opcode, nary->type,
+ genop1);
+ }
+ break;
+ default:
+ return NULL_TREE;
+ }
+ }
+ break;
+ default:
+ return NULL_TREE;
+ }
+ folded = fold_convert (exprtype, folded);
+ /* Force the generated expression to be a sequence of GIMPLE
+ statements.
+ We have to call unshare_expr because force_gimple_operand may
+ modify the tree we pass to it. */
+ newexpr = force_gimple_operand (unshare_expr (folded), &forced_stmts,
+ false, NULL);
+
+ /* If we have any intermediate expressions to the value sets, add them
+ to the value sets and chain them in the instruction stream. */
+ if (forced_stmts)
+ {
+ gsi = gsi_start (forced_stmts);
+ for (; !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ gimple stmt = gsi_stmt (gsi);
+ tree forcedname = gimple_get_lhs (stmt);
+ pre_expr nameexpr;
+
+ VEC_safe_push (gimple, heap, inserted_exprs, stmt);
+ if (TREE_CODE (forcedname) == SSA_NAME)
+ {
+ VN_INFO_GET (forcedname)->valnum = forcedname;
+ VN_INFO (forcedname)->value_id = get_next_value_id ();
+ nameexpr = get_or_alloc_expr_for_name (forcedname);
+ add_to_value (VN_INFO (forcedname)->value_id, nameexpr);
+ if (!in_fre)
+ bitmap_value_replace_in_set (NEW_SETS (block), nameexpr);
+ bitmap_value_replace_in_set (AVAIL_OUT (block), nameexpr);
+ }
+ mark_symbols_for_renaming (stmt);
+ }
+ gimple_seq_add_seq (stmts, forced_stmts);
+ }
+
+ /* Build and insert the assignment of the end result to the temporary
+ that we will return. */
+ if (!pretemp || exprtype != TREE_TYPE (pretemp))
+ {
+ pretemp = create_tmp_var (exprtype, "pretmp");
+ get_var_ann (pretemp);
+ }
+
+ temp = pretemp;
+ add_referenced_var (temp);
+
+ if (TREE_CODE (exprtype) == COMPLEX_TYPE
+ || TREE_CODE (exprtype) == VECTOR_TYPE)
+ DECL_GIMPLE_REG_P (temp) = 1;
+
+ newstmt = gimple_build_assign (temp, newexpr);
+ name = make_ssa_name (temp, newstmt);
+ gimple_assign_set_lhs (newstmt, name);
+ gimple_set_plf (newstmt, NECESSARY, false);
+
+ gimple_seq_add_stmt (stmts, newstmt);
+ VEC_safe_push (gimple, heap, inserted_exprs, newstmt);
+
+ /* All the symbols in NEWEXPR should be put into SSA form. */
+ mark_symbols_for_renaming (newstmt);
+
+ /* Add a value number to the temporary.
+ The value may already exist in either NEW_SETS, or AVAIL_OUT, because
+ we are creating the expression by pieces, and this particular piece of
+ the expression may have been represented. There is no harm in replacing
+ here. */
+ VN_INFO_GET (name)->valnum = name;
+ value_id = get_expr_value_id (expr);
+ VN_INFO (name)->value_id = value_id;
+ nameexpr = get_or_alloc_expr_for_name (name);
+ add_to_value (value_id, nameexpr);
+ if (!in_fre)
+ bitmap_value_replace_in_set (NEW_SETS (block), nameexpr);
+ bitmap_value_replace_in_set (AVAIL_OUT (block), nameexpr);
+
+ pre_stats.insertions++;
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Inserted ");
+ print_gimple_stmt (dump_file, newstmt, 0, 0);
+ fprintf (dump_file, " in predecessor %d\n", block->index);
+ }
+
+ return name;
+}
+
+
+/* Insert the to-be-made-available values of expression EXPRNUM for each
+ predecessor, stored in AVAIL, into the predecessors of BLOCK, and
+ merge the result with a phi node, given the same value number as
+ NODE. Return true if we have inserted new stuff. */
+
+static bool
+insert_into_preds_of_block (basic_block block, unsigned int exprnum,
+ pre_expr *avail)
+{
+ pre_expr expr = expression_for_id (exprnum);
+ pre_expr newphi;
+ unsigned int val = get_expr_value_id (expr);
+ edge pred;
+ bool insertions = false;
+ bool nophi = false;
+ basic_block bprime;
+ pre_expr eprime;
+ edge_iterator ei;
+ tree type = get_expr_type (expr);
+ tree temp;
+ gimple phi;
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Found partial redundancy for expression ");
+ print_pre_expr (dump_file, expr);
+ fprintf (dump_file, " (%04d)\n", val);
+ }
+
+ /* Make sure we aren't creating an induction variable. */
+ if (block->loop_depth > 0 && EDGE_COUNT (block->preds) == 2
+ && expr->kind != REFERENCE)
+ {
+ bool firstinsideloop = false;
+ bool secondinsideloop = false;
+ firstinsideloop = flow_bb_inside_loop_p (block->loop_father,
+ EDGE_PRED (block, 0)->src);
+ secondinsideloop = flow_bb_inside_loop_p (block->loop_father,
+ EDGE_PRED (block, 1)->src);
+ /* Induction variables only have one edge inside the loop. */
+ if (firstinsideloop ^ secondinsideloop)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Skipping insertion of phi for partial redundancy: Looks like an induction variable\n");
+ nophi = true;
+ }
+ }
+
+ /* Make sure we are not inserting trapping expressions. */
+ FOR_EACH_EDGE (pred, ei, block->preds)
+ {
+ bprime = pred->src;
+ eprime = avail[bprime->index];
+ if (eprime->kind == NARY
+ && vn_nary_may_trap (PRE_EXPR_NARY (eprime)))
+ return false;
+ }
+
+ /* Make the necessary insertions. */
+ FOR_EACH_EDGE (pred, ei, block->preds)
+ {
+ gimple_seq stmts = NULL;
+ tree builtexpr;
+ bprime = pred->src;
+ eprime = avail[bprime->index];
+
+ if (eprime->kind != NAME && eprime->kind != CONSTANT)
+ {
+ builtexpr = create_expression_by_pieces (bprime,
+ eprime,
+ &stmts, NULL,
+ type);
+ gcc_assert (!(pred->flags & EDGE_ABNORMAL));
+ gsi_insert_seq_on_edge (pred, stmts);
+ avail[bprime->index] = get_or_alloc_expr_for_name (builtexpr);
+ insertions = true;
+ }
+ else if (eprime->kind == CONSTANT)
+ {
+ /* Constants may not have the right type, fold_convert
+ should give us back a constant with the right type.
+ */
+ tree constant = PRE_EXPR_CONSTANT (eprime);
+ if (!useless_type_conversion_p (type, TREE_TYPE (constant)))
+ {
+ tree builtexpr = fold_convert (type, constant);
+ if (!is_gimple_min_invariant (builtexpr))
+ {
+ tree forcedexpr = force_gimple_operand (builtexpr,
+ &stmts, true,
+ NULL);
+ if (!is_gimple_min_invariant (forcedexpr))
+ {
+ if (forcedexpr != builtexpr)
+ {
+ VN_INFO_GET (forcedexpr)->valnum = PRE_EXPR_CONSTANT (eprime);
+ VN_INFO (forcedexpr)->value_id = get_expr_value_id (eprime);
+ }
+ if (stmts)
+ {
+ gimple_stmt_iterator gsi;
+ gsi = gsi_start (stmts);
+ for (; !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ gimple stmt = gsi_stmt (gsi);
+ VEC_safe_push (gimple, heap, inserted_exprs, stmt);
+ gimple_set_plf (stmt, NECESSARY, false);
+ }
+ gsi_insert_seq_on_edge (pred, stmts);
+ }
+ avail[bprime->index] = get_or_alloc_expr_for_name (forcedexpr);
+ }
+ }
+ }
+ }
+ else if (eprime->kind == NAME)
+ {
+ /* We may have to do a conversion because our value
+ numbering can look through types in certain cases, but
+ our IL requires all operands of a phi node have the same
+ type. */
+ tree name = PRE_EXPR_NAME (eprime);
+ if (!useless_type_conversion_p (type, TREE_TYPE (name)))
+ {
+ tree builtexpr;
+ tree forcedexpr;
+ builtexpr = fold_convert (type, name);
+ forcedexpr = force_gimple_operand (builtexpr,
+ &stmts, true,
+ NULL);
+
+ if (forcedexpr != name)
+ {
+ VN_INFO_GET (forcedexpr)->valnum = VN_INFO (name)->valnum;
+ VN_INFO (forcedexpr)->value_id = VN_INFO (name)->value_id;
+ }
+
+ if (stmts)
+ {
+ gimple_stmt_iterator gsi;
+ gsi = gsi_start (stmts);
+ for (; !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ gimple stmt = gsi_stmt (gsi);
+ VEC_safe_push (gimple, heap, inserted_exprs, stmt);
+ gimple_set_plf (stmt, NECESSARY, false);
+ }
+ gsi_insert_seq_on_edge (pred, stmts);
+ }
+ avail[bprime->index] = get_or_alloc_expr_for_name (forcedexpr);
+ }
+ }
+ }
+ /* If we didn't want a phi node, and we made insertions, we still have
+ inserted new stuff, and thus return true. If we didn't want a phi node,
+ and didn't make insertions, we haven't added anything new, so return
+ false. */
+ if (nophi && insertions)
+ return true;
+ else if (nophi && !insertions)
+ return false;
+
+ /* Now build a phi for the new variable. */
+ if (!prephitemp || TREE_TYPE (prephitemp) != type)
+ {
+ prephitemp = create_tmp_var (type, "prephitmp");
+ get_var_ann (prephitemp);
+ }
+
+ temp = prephitemp;
+ add_referenced_var (temp);
+
+ if (TREE_CODE (type) == COMPLEX_TYPE
+ || TREE_CODE (type) == VECTOR_TYPE)
+ DECL_GIMPLE_REG_P (temp) = 1;
+ phi = create_phi_node (temp, block);
+
+ gimple_set_plf (phi, NECESSARY, false);
+ VN_INFO_GET (gimple_phi_result (phi))->valnum = gimple_phi_result (phi);
+ VN_INFO (gimple_phi_result (phi))->value_id = val;
+ VEC_safe_push (gimple, heap, inserted_exprs, phi);
+ FOR_EACH_EDGE (pred, ei, block->preds)
+ {
+ pre_expr ae = avail[pred->src->index];
+ gcc_assert (get_expr_type (ae) == type
+ || useless_type_conversion_p (type, get_expr_type (ae)));
+ if (ae->kind == CONSTANT)
+ add_phi_arg (phi, PRE_EXPR_CONSTANT (ae), pred);
+ else
+ add_phi_arg (phi, PRE_EXPR_NAME (avail[pred->src->index]), pred);
+ }
+
+ newphi = get_or_alloc_expr_for_name (gimple_phi_result (phi));
+ add_to_value (val, newphi);
+
+ /* The value should *not* exist in PHI_GEN, or else we wouldn't be doing
+ this insertion, since we test for the existence of this value in PHI_GEN
+ before proceeding with the partial redundancy checks in insert_aux.
+
+ The value may exist in AVAIL_OUT, in particular, it could be represented
+ by the expression we are trying to eliminate, in which case we want the
+ replacement to occur. If it's not existing in AVAIL_OUT, we want it
+ inserted there.
+
+ Similarly, to the PHI_GEN case, the value should not exist in NEW_SETS of
+ this block, because if it did, it would have existed in our dominator's
+ AVAIL_OUT, and would have been skipped due to the full redundancy check.
+ */
+
+ bitmap_insert_into_set (PHI_GEN (block), newphi);
+ bitmap_value_replace_in_set (AVAIL_OUT (block),
+ newphi);
+ bitmap_insert_into_set (NEW_SETS (block),
+ newphi);
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Created phi ");
+ print_gimple_stmt (dump_file, phi, 0, 0);
+ fprintf (dump_file, " in block %d\n", block->index);
+ }
+ pre_stats.phis++;
+ return true;
+}
+
+
+
+/* Perform insertion of partially redundant values.
+ For BLOCK, do the following:
+ 1. Propagate the NEW_SETS of the dominator into the current block.
+ If the block has multiple predecessors,
+ 2a. Iterate over the ANTIC expressions for the block to see if
+ any of them are partially redundant.
+ 2b. If so, insert them into the necessary predecessors to make
+ the expression fully redundant.
+ 2c. Insert a new PHI merging the values of the predecessors.
+ 2d. Insert the new PHI, and the new expressions, into the
+ NEW_SETS set.
+ 3. Recursively call ourselves on the dominator children of BLOCK.
+
+ Steps 1, 2a, and 3 are done by insert_aux. 2b, 2c and 2d are done by
+ do_regular_insertion and do_partial_insertion.
+
+*/
+
+static bool
+do_regular_insertion (basic_block block, basic_block dom)
+{
+ bool new_stuff = false;
+ VEC (pre_expr, heap) *exprs = sorted_array_from_bitmap_set (ANTIC_IN (block));
+ pre_expr expr;
+ int i;
+
+ for (i = 0; VEC_iterate (pre_expr, exprs, i, expr); i++)
+ {
+ if (expr->kind != NAME)
+ {
+ pre_expr *avail;
+ unsigned int val;
+ bool by_some = false;
+ bool cant_insert = false;
+ bool all_same = true;
+ pre_expr first_s = NULL;
+ edge pred;
+ basic_block bprime;
+ pre_expr eprime = NULL;
+ edge_iterator ei;
+ pre_expr edoubleprime = NULL;
+
+ val = get_expr_value_id (expr);
+ if (bitmap_set_contains_value (PHI_GEN (block), val))
+ continue;
+ if (bitmap_set_contains_value (AVAIL_OUT (dom), val))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Found fully redundant value\n");
+ continue;
+ }
+
+ avail = XCNEWVEC (pre_expr, last_basic_block);
+ FOR_EACH_EDGE (pred, ei, block->preds)
+ {
+ unsigned int vprime;
+
+ /* We should never run insertion for the exit block
+ and so not come across fake pred edges. */
+ gcc_assert (!(pred->flags & EDGE_FAKE));
+ bprime = pred->src;
+ eprime = phi_translate (expr, ANTIC_IN (block), NULL,
+ bprime, block);
+
+ /* eprime will generally only be NULL if the
+ value of the expression, translated
+ through the PHI for this predecessor, is
+ undefined. If that is the case, we can't
+ make the expression fully redundant,
+ because its value is undefined along a
+ predecessor path. We can thus break out
+ early because it doesn't matter what the
+ rest of the results are. */
+ if (eprime == NULL)
+ {
+ cant_insert = true;
+ break;
+ }
+
+ eprime = fully_constant_expression (eprime);
+ vprime = get_expr_value_id (eprime);
+ edoubleprime = bitmap_find_leader (AVAIL_OUT (bprime),
+ vprime, NULL);
+ if (edoubleprime == NULL)
+ {
+ avail[bprime->index] = eprime;
+ all_same = false;
+ }
+ else
+ {
+ avail[bprime->index] = edoubleprime;
+ by_some = true;
+ if (first_s == NULL)
+ first_s = edoubleprime;
+ else if (!pre_expr_eq (first_s, edoubleprime))
+ all_same = false;
+ }
+ }
+ /* If we can insert it, it's not the same value
+ already existing along every predecessor, and
+ it's defined by some predecessor, it is
+ partially redundant. */
+ if (!cant_insert && !all_same && by_some && dbg_cnt (treepre_insert))
+ {
+ if (insert_into_preds_of_block (block, get_expression_id (expr),
+ avail))
+ new_stuff = true;
+ }
+ /* If all edges produce the same value and that value is
+ an invariant, then the PHI has the same value on all
+ edges. Note this. */
+ else if (!cant_insert && all_same && eprime
+ && (edoubleprime->kind == CONSTANT
+ || edoubleprime->kind == NAME)
+ && !value_id_constant_p (val))
+ {
+ unsigned int j;
+ bitmap_iterator bi;
+ bitmap_set_t exprset = VEC_index (bitmap_set_t,
+ value_expressions, val);
+
+ unsigned int new_val = get_expr_value_id (edoubleprime);
+ FOR_EACH_EXPR_ID_IN_SET (exprset, j, bi)
+ {
+ pre_expr expr = expression_for_id (j);
+
+ if (expr->kind == NAME)
+ {
+ vn_ssa_aux_t info = VN_INFO (PRE_EXPR_NAME (expr));
+ /* Just reset the value id and valnum so it is
+ the same as the constant we have discovered. */
+ if (edoubleprime->kind == CONSTANT)
+ {
+ info->valnum = PRE_EXPR_CONSTANT (edoubleprime);
+ pre_stats.constified++;
+ }
+ else
+ info->valnum = VN_INFO (PRE_EXPR_NAME (edoubleprime))->valnum;
+ info->value_id = new_val;
+ }
+ }
+ }
+ free (avail);
+ }
+ }
+
+ VEC_free (pre_expr, heap, exprs);
+ return new_stuff;
+}
+
+
+/* Perform insertion for partially anticipatable expressions. There
+ is only one case we will perform insertion for these. This case is
+ if the expression is partially anticipatable, and fully available.
+ In this case, we know that putting it earlier will enable us to
+ remove the later computation. */
+
+
+static bool
+do_partial_partial_insertion (basic_block block, basic_block dom)
+{
+ bool new_stuff = false;
+ VEC (pre_expr, heap) *exprs = sorted_array_from_bitmap_set (PA_IN (block));
+ pre_expr expr;
+ int i;
+
+ for (i = 0; VEC_iterate (pre_expr, exprs, i, expr); i++)
+ {
+ if (expr->kind != NAME)
+ {
+ pre_expr *avail;
+ unsigned int val;
+ bool by_all = true;
+ bool cant_insert = false;
+ edge pred;
+ basic_block bprime;
+ pre_expr eprime = NULL;
+ edge_iterator ei;
+
+ val = get_expr_value_id (expr);
+ if (bitmap_set_contains_value (PHI_GEN (block), val))
+ continue;
+ if (bitmap_set_contains_value (AVAIL_OUT (dom), val))
+ continue;
+
+ avail = XCNEWVEC (pre_expr, last_basic_block);
+ FOR_EACH_EDGE (pred, ei, block->preds)
+ {
+ unsigned int vprime;
+ pre_expr edoubleprime;
+
+ /* We should never run insertion for the exit block
+ and so not come across fake pred edges. */
+ gcc_assert (!(pred->flags & EDGE_FAKE));
+ bprime = pred->src;
+ eprime = phi_translate (expr, ANTIC_IN (block),
+ PA_IN (block),
+ bprime, block);
+
+ /* eprime will generally only be NULL if the
+ value of the expression, translated
+ through the PHI for this predecessor, is
+ undefined. If that is the case, we can't
+ make the expression fully redundant,
+ because its value is undefined along a
+ predecessor path. We can thus break out
+ early because it doesn't matter what the
+ rest of the results are. */
+ if (eprime == NULL)
+ {
+ cant_insert = true;
+ break;
+ }
+
+ eprime = fully_constant_expression (eprime);
+ vprime = get_expr_value_id (eprime);
+ edoubleprime = bitmap_find_leader (AVAIL_OUT (bprime),
+ vprime, NULL);
+ if (edoubleprime == NULL)
+ {
+ by_all = false;
+ break;
+ }
+ else
+ avail[bprime->index] = edoubleprime;
+
+ }
+
+ /* If we can insert it, it's not the same value
+ already existing along every predecessor, and
+ it's defined by some predecessor, it is
+ partially redundant. */
+ if (!cant_insert && by_all && dbg_cnt (treepre_insert))
+ {
+ pre_stats.pa_insert++;
+ if (insert_into_preds_of_block (block, get_expression_id (expr),
+ avail))
+ new_stuff = true;
+ }
+ free (avail);
+ }
+ }
+
+ VEC_free (pre_expr, heap, exprs);
+ return new_stuff;
+}
+
+static bool
+insert_aux (basic_block block)
+{
+ basic_block son;
+ bool new_stuff = false;
+
+ if (block)
+ {
+ basic_block dom;
+ dom = get_immediate_dominator (CDI_DOMINATORS, block);
+ if (dom)
+ {
+ unsigned i;
+ bitmap_iterator bi;
+ bitmap_set_t newset = NEW_SETS (dom);
+ if (newset)
+ {
+ /* Note that we need to value_replace both NEW_SETS, and
+ AVAIL_OUT. For both the case of NEW_SETS, the value may be
+ represented by some non-simple expression here that we want
+ to replace it with. */
+ FOR_EACH_EXPR_ID_IN_SET (newset, i, bi)
+ {
+ pre_expr expr = expression_for_id (i);
+ bitmap_value_replace_in_set (NEW_SETS (block), expr);
+ bitmap_value_replace_in_set (AVAIL_OUT (block), expr);
+ }
+ }
+ if (!single_pred_p (block))
+ {
+ new_stuff |= do_regular_insertion (block, dom);
+ if (do_partial_partial)
+ new_stuff |= do_partial_partial_insertion (block, dom);
+ }
+ }
+ }
+ for (son = first_dom_son (CDI_DOMINATORS, block);
+ son;
+ son = next_dom_son (CDI_DOMINATORS, son))
+ {
+ new_stuff |= insert_aux (son);
+ }
+
+ return new_stuff;
+}
+
+/* Perform insertion of partially redundant values. */
+
+static void
+insert (void)
+{
+ bool new_stuff = true;
+ basic_block bb;
+ int num_iterations = 0;
+
+ FOR_ALL_BB (bb)
+ NEW_SETS (bb) = bitmap_set_new ();
+
+ while (new_stuff)
+ {
+ num_iterations++;
+ new_stuff = insert_aux (ENTRY_BLOCK_PTR);
+ }
+ statistics_histogram_event (cfun, "insert iterations", num_iterations);
+}
+
+
+/* Add OP to EXP_GEN (block), and possibly to the maximal set. */
+
+static void
+add_to_exp_gen (basic_block block, tree op)
+{
+ if (!in_fre)
+ {
+ pre_expr result;
+ if (TREE_CODE (op) == SSA_NAME && ssa_undefined_value_p (op))
+ return;
+ result = get_or_alloc_expr_for_name (op);
+ bitmap_value_insert_into_set (EXP_GEN (block), result);
+ }
+}
+
+/* Create value ids for PHI in BLOCK. */
+
+static void
+make_values_for_phi (gimple phi, basic_block block)
+{
+ tree result = gimple_phi_result (phi);
+
+ /* We have no need for virtual phis, as they don't represent
+ actual computations. */
+ if (is_gimple_reg (result))
+ {
+ pre_expr e = get_or_alloc_expr_for_name (result);
+ add_to_value (get_expr_value_id (e), e);
+ bitmap_insert_into_set (PHI_GEN (block), e);
+ bitmap_value_insert_into_set (AVAIL_OUT (block), e);
+ if (!in_fre)
+ {
+ unsigned i;
+ for (i = 0; i < gimple_phi_num_args (phi); ++i)
+ {
+ tree arg = gimple_phi_arg_def (phi, i);
+ if (TREE_CODE (arg) == SSA_NAME)
+ {
+ e = get_or_alloc_expr_for_name (arg);
+ add_to_value (get_expr_value_id (e), e);
+ }
+ }
+ }
+ }
+}
+
+/* Compute the AVAIL set for all basic blocks.
+
+ This function performs value numbering of the statements in each basic
+ block. The AVAIL sets are built from information we glean while doing
+ this value numbering, since the AVAIL sets contain only one entry per
+ value.
+
+ AVAIL_IN[BLOCK] = AVAIL_OUT[dom(BLOCK)].
+ AVAIL_OUT[BLOCK] = AVAIL_IN[BLOCK] U PHI_GEN[BLOCK] U TMP_GEN[BLOCK]. */
+
+static void
+compute_avail (void)
+{
+
+ basic_block block, son;
+ basic_block *worklist;
+ size_t sp = 0;
+ tree param;
+
+ /* For arguments with default definitions, we pretend they are
+ defined in the entry block. */
+ for (param = DECL_ARGUMENTS (current_function_decl);
+ param;
+ param = TREE_CHAIN (param))
+ {
+ if (gimple_default_def (cfun, param) != NULL)
+ {
+ tree def = gimple_default_def (cfun, param);
+ pre_expr e = get_or_alloc_expr_for_name (def);
+
+ add_to_value (get_expr_value_id (e), e);
+ if (!in_fre)
+ bitmap_insert_into_set (TMP_GEN (ENTRY_BLOCK_PTR), e);
+ bitmap_value_insert_into_set (AVAIL_OUT (ENTRY_BLOCK_PTR), e);
+ }
+ }
+
+ /* Likewise for the static chain decl. */
+ if (cfun->static_chain_decl)
+ {
+ param = cfun->static_chain_decl;
+ if (gimple_default_def (cfun, param) != NULL)
+ {
+ tree def = gimple_default_def (cfun, param);
+ pre_expr e = get_or_alloc_expr_for_name (def);
+
+ add_to_value (get_expr_value_id (e), e);
+ if (!in_fre)
+ bitmap_insert_into_set (TMP_GEN (ENTRY_BLOCK_PTR), e);
+ bitmap_value_insert_into_set (AVAIL_OUT (ENTRY_BLOCK_PTR), e);
+ }
+ }
+
+ /* Allocate the worklist. */
+ worklist = XNEWVEC (basic_block, n_basic_blocks);
+
+ /* Seed the algorithm by putting the dominator children of the entry
+ block on the worklist. */
+ for (son = first_dom_son (CDI_DOMINATORS, ENTRY_BLOCK_PTR);
+ son;
+ son = next_dom_son (CDI_DOMINATORS, son))
+ worklist[sp++] = son;
+
+ /* Loop until the worklist is empty. */
+ while (sp)
+ {
+ gimple_stmt_iterator gsi;
+ gimple stmt;
+ basic_block dom;
+ unsigned int stmt_uid = 1;
+
+ /* Pick a block from the worklist. */
+ block = worklist[--sp];
+
+ /* Initially, the set of available values in BLOCK is that of
+ its immediate dominator. */
+ dom = get_immediate_dominator (CDI_DOMINATORS, block);
+ if (dom)
+ bitmap_set_copy (AVAIL_OUT (block), AVAIL_OUT (dom));
+
+ /* Generate values for PHI nodes. */
+ for (gsi = gsi_start_phis (block); !gsi_end_p (gsi); gsi_next (&gsi))
+ make_values_for_phi (gsi_stmt (gsi), block);
+
+ /* Now compute value numbers and populate value sets with all
+ the expressions computed in BLOCK. */
+ for (gsi = gsi_start_bb (block); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ ssa_op_iter iter;
+ tree op;
+
+ stmt = gsi_stmt (gsi);
+ gimple_set_uid (stmt, stmt_uid++);
+
+ FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_DEF)
+ {
+ pre_expr e = get_or_alloc_expr_for_name (op);
+
+ add_to_value (get_expr_value_id (e), e);
+ if (!in_fre)
+ bitmap_insert_into_set (TMP_GEN (block), e);
+ bitmap_value_insert_into_set (AVAIL_OUT (block), e);
+ }
+
+ if (gimple_has_volatile_ops (stmt)
+ || stmt_could_throw_p (stmt))
+ continue;
+
+ switch (gimple_code (stmt))
+ {
+ case GIMPLE_RETURN:
+ FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_USE)
+ add_to_exp_gen (block, op);
+ continue;
+
+ case GIMPLE_CALL:
+ {
+ vn_reference_t ref;
+ unsigned int i;
+ vn_reference_op_t vro;
+ pre_expr result = NULL;
+ VEC(vn_reference_op_s, heap) *ops = NULL;
+
+ if (!can_value_number_call (stmt))
+ continue;
+
+ copy_reference_ops_from_call (stmt, &ops);
+ vn_reference_lookup_pieces (shared_vuses_from_stmt (stmt),
+ ops, &ref, false);
+ VEC_free (vn_reference_op_s, heap, ops);
+ if (!ref)
+ continue;
+
+ for (i = 0; VEC_iterate (vn_reference_op_s,
+ ref->operands, i,
+ vro); i++)
+ {
+ if (vro->op0 && TREE_CODE (vro->op0) == SSA_NAME)
+ add_to_exp_gen (block, vro->op0);
+ if (vro->op1 && TREE_CODE (vro->op1) == SSA_NAME)
+ add_to_exp_gen (block, vro->op1);
+ if (vro->op2 && TREE_CODE (vro->op2) == SSA_NAME)
+ add_to_exp_gen (block, vro->op2);
+ }
+ result = (pre_expr) pool_alloc (pre_expr_pool);
+ result->kind = REFERENCE;
+ result->id = 0;
+ PRE_EXPR_REFERENCE (result) = ref;
+
+ get_or_alloc_expression_id (result);
+ add_to_value (get_expr_value_id (result), result);
+ if (!in_fre)
+ bitmap_value_insert_into_set (EXP_GEN (block), result);
+ continue;
+ }
+
+ case GIMPLE_ASSIGN:
+ {
+ pre_expr result = NULL;
+ switch (TREE_CODE_CLASS (gimple_assign_rhs_code (stmt)))
+ {
+ case tcc_unary:
+ if (is_exception_related (stmt))
+ continue;
+ case tcc_binary:
+ case tcc_comparison:
+ {
+ vn_nary_op_t nary;
+ unsigned int i;
+
+ vn_nary_op_lookup_pieces (gimple_num_ops (stmt) - 1,
+ gimple_assign_rhs_code (stmt),
+ gimple_expr_type (stmt),
+ gimple_assign_rhs1 (stmt),
+ gimple_assign_rhs2 (stmt),
+ NULL_TREE, NULL_TREE, &nary);
+
+ if (!nary)
+ continue;
+
+ for (i = 0; i < nary->length; i++)
+ if (TREE_CODE (nary->op[i]) == SSA_NAME)
+ add_to_exp_gen (block, nary->op[i]);
+
+ result = (pre_expr) pool_alloc (pre_expr_pool);
+ result->kind = NARY;
+ result->id = 0;
+ PRE_EXPR_NARY (result) = nary;
+ break;
+ }
+
+ case tcc_declaration:
+ case tcc_reference:
+ {
+ vn_reference_t ref;
+ unsigned int i;
+ vn_reference_op_t vro;
+
+ vn_reference_lookup (gimple_assign_rhs1 (stmt),
+ shared_vuses_from_stmt (stmt),
+ false, &ref);
+ if (!ref)
+ continue;
+
+ for (i = 0; VEC_iterate (vn_reference_op_s,
+ ref->operands, i,
+ vro); i++)
+ {
+ if (vro->op0 && TREE_CODE (vro->op0) == SSA_NAME)
+ add_to_exp_gen (block, vro->op0);
+ if (vro->op1 && TREE_CODE (vro->op1) == SSA_NAME)
+ add_to_exp_gen (block, vro->op1);
+ if (vro->op2 && TREE_CODE (vro->op2) == SSA_NAME)
+ add_to_exp_gen (block, vro->op2);
+ }
+ result = (pre_expr) pool_alloc (pre_expr_pool);
+ result->kind = REFERENCE;
+ result->id = 0;
+ PRE_EXPR_REFERENCE (result) = ref;
+ break;
+ }
+
+ default:
+ /* For any other statement that we don't
+ recognize, simply add all referenced
+ SSA_NAMEs to EXP_GEN. */
+ FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_USE)
+ add_to_exp_gen (block, op);
+ continue;
+ }
+
+ get_or_alloc_expression_id (result);
+ add_to_value (get_expr_value_id (result), result);
+ if (!in_fre)
+ bitmap_value_insert_into_set (EXP_GEN (block), result);
+
+ continue;
+ }
+ default:
+ break;
+ }
+ }
+
+ /* Put the dominator children of BLOCK on the worklist of blocks
+ to compute available sets for. */
+ for (son = first_dom_son (CDI_DOMINATORS, block);
+ son;
+ son = next_dom_son (CDI_DOMINATORS, son))
+ worklist[sp++] = son;
+ }
+
+ free (worklist);
+}
+
+/* Insert the expression for SSA_VN that SCCVN thought would be simpler
+ than the available expressions for it. The insertion point is
+ right before the first use in STMT. Returns the SSA_NAME that should
+ be used for replacement. */
+
+static tree
+do_SCCVN_insertion (gimple stmt, tree ssa_vn)
+{
+ basic_block bb = gimple_bb (stmt);
+ gimple_stmt_iterator gsi;
+ gimple_seq stmts = NULL;
+ tree expr;
+ pre_expr e;
+
+ /* First create a value expression from the expression we want
+ to insert and associate it with the value handle for SSA_VN. */
+ e = get_or_alloc_expr_for (vn_get_expr_for (ssa_vn));
+ if (e == NULL)
+ return NULL_TREE;
+
+ /* Then use create_expression_by_pieces to generate a valid
+ expression to insert at this point of the IL stream. */
+ expr = create_expression_by_pieces (bb, e, &stmts, stmt, NULL);
+ if (expr == NULL_TREE)
+ return NULL_TREE;
+ gsi = gsi_for_stmt (stmt);
+ gsi_insert_seq_before (&gsi, stmts, GSI_SAME_STMT);
+
+ return expr;
+}
+
+/* Eliminate fully redundant computations. */
+
+static unsigned int
+eliminate (void)
+{
+ basic_block b;
+ unsigned int todo = 0;
+
+ FOR_EACH_BB (b)
+ {
+ gimple_stmt_iterator i;
+
+ for (i = gsi_start_bb (b); !gsi_end_p (i); gsi_next (&i))
+ {
+ gimple stmt = gsi_stmt (i);
+
+ /* Lookup the RHS of the expression, see if we have an
+ available computation for it. If so, replace the RHS with
+ the available computation. */
+ if (gimple_has_lhs (stmt)
+ && TREE_CODE (gimple_get_lhs (stmt)) == SSA_NAME
+ && !gimple_assign_ssa_name_copy_p (stmt)
+ && (!gimple_assign_single_p (stmt)
+ || !is_gimple_min_invariant (gimple_assign_rhs1 (stmt)))
+ && !gimple_has_volatile_ops (stmt)
+ && !has_zero_uses (gimple_get_lhs (stmt)))
+ {
+ tree lhs = gimple_get_lhs (stmt);
+ tree rhs = NULL_TREE;
+ tree sprime = NULL;
+ pre_expr lhsexpr = get_or_alloc_expr_for_name (lhs);
+ pre_expr sprimeexpr;
+
+ if (gimple_assign_single_p (stmt))
+ rhs = gimple_assign_rhs1 (stmt);
+
+ sprimeexpr = bitmap_find_leader (AVAIL_OUT (b),
+ get_expr_value_id (lhsexpr),
+ NULL);
+
+ if (sprimeexpr)
+ {
+ if (sprimeexpr->kind == CONSTANT)
+ sprime = PRE_EXPR_CONSTANT (sprimeexpr);
+ else if (sprimeexpr->kind == NAME)
+ sprime = PRE_EXPR_NAME (sprimeexpr);
+ else
+ gcc_unreachable ();
+ }
+
+ /* If there is no existing leader but SCCVN knows this
+ value is constant, use that constant. */
+ if (!sprime && is_gimple_min_invariant (VN_INFO (lhs)->valnum))
+ {
+ sprime = fold_convert (TREE_TYPE (lhs),
+ VN_INFO (lhs)->valnum);
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Replaced ");
+ print_gimple_expr (dump_file, stmt, 0, 0);
+ fprintf (dump_file, " with ");
+ print_generic_expr (dump_file, sprime, 0);
+ fprintf (dump_file, " in ");
+ print_gimple_stmt (dump_file, stmt, 0, 0);
+ }
+ pre_stats.eliminations++;
+ propagate_tree_value_into_stmt (&i, sprime);
+ stmt = gsi_stmt (i);
+ update_stmt (stmt);
+ continue;
+ }
+
+ /* If there is no existing usable leader but SCCVN thinks
+ it has an expression it wants to use as replacement,
+ insert that. */
+ if (!sprime || sprime == lhs)
+ {
+ tree val = VN_INFO (lhs)->valnum;
+ if (val != VN_TOP
+ && TREE_CODE (val) == SSA_NAME
+ && VN_INFO (val)->needs_insertion
+ && can_PRE_operation (vn_get_expr_for (val)))
+ sprime = do_SCCVN_insertion (stmt, val);
+ }
+ if (sprime
+ && sprime != lhs
+ && (rhs == NULL_TREE
+ || TREE_CODE (rhs) != SSA_NAME
+ || may_propagate_copy (rhs, sprime)))
+ {
+ gcc_assert (sprime != rhs);
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Replaced ");
+ print_gimple_expr (dump_file, stmt, 0, 0);
+ fprintf (dump_file, " with ");
+ print_generic_expr (dump_file, sprime, 0);
+ fprintf (dump_file, " in ");
+ print_gimple_stmt (dump_file, stmt, 0, 0);
+ }
+
+ if (TREE_CODE (sprime) == SSA_NAME)
+ gimple_set_plf (SSA_NAME_DEF_STMT (sprime),
+ NECESSARY, true);
+ /* We need to make sure the new and old types actually match,
+ which may require adding a simple cast, which fold_convert
+ will do for us. */
+ if ((!rhs || TREE_CODE (rhs) != SSA_NAME)
+ && !useless_type_conversion_p (gimple_expr_type (stmt),
+ TREE_TYPE (sprime)))
+ sprime = fold_convert (gimple_expr_type (stmt), sprime);
+
+ pre_stats.eliminations++;
+ propagate_tree_value_into_stmt (&i, sprime);
+ stmt = gsi_stmt (i);
+ update_stmt (stmt);
+
+ /* If we removed EH side effects from the statement, clean
+ its EH information. */
+ if (maybe_clean_or_replace_eh_stmt (stmt, stmt))
+ {
+ bitmap_set_bit (need_eh_cleanup,
+ gimple_bb (stmt)->index);
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, " Removed EH side effects.\n");
+ }
+ }
+ }
+ /* Visit COND_EXPRs and fold the comparison with the
+ available value-numbers. */
+ else if (gimple_code (stmt) == GIMPLE_COND)
+ {
+ tree op0 = gimple_cond_lhs (stmt);
+ tree op1 = gimple_cond_rhs (stmt);
+ tree result;
+
+ if (TREE_CODE (op0) == SSA_NAME)
+ op0 = VN_INFO (op0)->valnum;
+ if (TREE_CODE (op1) == SSA_NAME)
+ op1 = VN_INFO (op1)->valnum;
+ result = fold_binary (gimple_cond_code (stmt), boolean_type_node,
+ op0, op1);
+ if (result && TREE_CODE (result) == INTEGER_CST)
+ {
+ if (integer_zerop (result))
+ gimple_cond_make_false (stmt);
+ else
+ gimple_cond_make_true (stmt);
+ update_stmt (stmt);
+ todo = TODO_cleanup_cfg;
+ }
+ }
+ }
+ }
+
+ return todo;
+}
+
+/* Borrow a bit of tree-ssa-dce.c for the moment.
+ XXX: In 4.1, we should be able to just run a DCE pass after PRE, though
+ this may be a bit faster, and we may want critical edges kept split. */
+
+/* If OP's defining statement has not already been determined to be necessary,
+ mark that statement necessary. Return the stmt, if it is newly
+ necessary. */
+
+static inline gimple
+mark_operand_necessary (tree op)
+{
+ gimple stmt;
+
+ gcc_assert (op);
+
+ if (TREE_CODE (op) != SSA_NAME)
+ return NULL;
+
+ stmt = SSA_NAME_DEF_STMT (op);
+ gcc_assert (stmt);
+
+ if (gimple_plf (stmt, NECESSARY)
+ || gimple_nop_p (stmt))
+ return NULL;
+
+ gimple_set_plf (stmt, NECESSARY, true);
+ return stmt;
+}
+
+/* Because we don't follow exactly the standard PRE algorithm, and decide not
+ to insert PHI nodes sometimes, and because value numbering of casts isn't
+ perfect, we sometimes end up inserting dead code. This simple DCE-like
+ pass removes any insertions we made that weren't actually used. */
+
+static void
+remove_dead_inserted_code (void)
+{
+ VEC(gimple,heap) *worklist = NULL;
+ int i;
+ gimple t;
+
+ worklist = VEC_alloc (gimple, heap, VEC_length (gimple, inserted_exprs));
+ for (i = 0; VEC_iterate (gimple, inserted_exprs, i, t); i++)
+ {
+ if (gimple_plf (t, NECESSARY))
+ VEC_quick_push (gimple, worklist, t);
+ }
+ while (VEC_length (gimple, worklist) > 0)
+ {
+ t = VEC_pop (gimple, worklist);
+
+ /* PHI nodes are somewhat special in that each PHI alternative has
+ data and control dependencies. All the statements feeding the
+ PHI node's arguments are always necessary. */
+ if (gimple_code (t) == GIMPLE_PHI)
+ {
+ unsigned k;
+
+ VEC_reserve (gimple, heap, worklist, gimple_phi_num_args (t));
+ for (k = 0; k < gimple_phi_num_args (t); k++)
+ {
+ tree arg = PHI_ARG_DEF (t, k);
+ if (TREE_CODE (arg) == SSA_NAME)
+ {
+ gimple n = mark_operand_necessary (arg);
+ if (n)
+ VEC_quick_push (gimple, worklist, n);
+ }
+ }
+ }
+ else
+ {
+ /* Propagate through the operands. Examine all the USE, VUSE and
+ VDEF operands in this statement. Mark all the statements
+ which feed this statement's uses as necessary. */
+ ssa_op_iter iter;
+ tree use;
+
+ /* The operands of VDEF expressions are also needed as they
+ represent potential definitions that may reach this
+ statement (VDEF operands allow us to follow def-def
+ links). */
+
+ FOR_EACH_SSA_TREE_OPERAND (use, t, iter, SSA_OP_ALL_USES)
+ {
+ gimple n = mark_operand_necessary (use);
+ if (n)
+ VEC_safe_push (gimple, heap, worklist, n);
+ }
+ }
+ }
+
+ for (i = 0; VEC_iterate (gimple, inserted_exprs, i, t); i++)
+ {
+ if (!gimple_plf (t, NECESSARY))
+ {
+ gimple_stmt_iterator gsi;
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Removing unnecessary insertion:");
+ print_gimple_stmt (dump_file, t, 0, 0);
+ }
+
+ gsi = gsi_for_stmt (t);
+ if (gimple_code (t) == GIMPLE_PHI)
+ remove_phi_node (&gsi, true);
+ else
+ gsi_remove (&gsi, true);
+ release_defs (t);
+ }
+ }
+ VEC_free (gimple, heap, worklist);
+}
+
+/* Initialize data structures used by PRE. */
+
+static void
+init_pre (bool do_fre)
+{
+ basic_block bb;
+
+ next_expression_id = 1;
+ expressions = NULL;
+ VEC_safe_push (pre_expr, heap, expressions, NULL);
+ value_expressions = VEC_alloc (bitmap_set_t, heap, get_max_value_id () + 1);
+ VEC_safe_grow_cleared (bitmap_set_t, heap, value_expressions,
+ get_max_value_id() + 1);
+
+ in_fre = do_fre;
+
+ inserted_exprs = NULL;
+ need_creation = NULL;
+ pretemp = NULL_TREE;
+ storetemp = NULL_TREE;
+ prephitemp = NULL_TREE;
+
+ connect_infinite_loops_to_exit ();
+ memset (&pre_stats, 0, sizeof (pre_stats));
+
+
+ postorder = XNEWVEC (int, n_basic_blocks - NUM_FIXED_BLOCKS);
+ post_order_compute (postorder, false, false);
+
+ FOR_ALL_BB (bb)
+ bb->aux = XCNEWVEC (struct bb_bitmap_sets, 1);
+
+ calculate_dominance_info (CDI_POST_DOMINATORS);
+ calculate_dominance_info (CDI_DOMINATORS);
+
+ bitmap_obstack_initialize (&grand_bitmap_obstack);
+ phi_translate_table = htab_create (5110, expr_pred_trans_hash,
+ expr_pred_trans_eq, free);
+ expression_to_id = htab_create (num_ssa_names * 3,
+ pre_expr_hash,
+ pre_expr_eq, NULL);
+ bitmap_set_pool = create_alloc_pool ("Bitmap sets",
+ sizeof (struct bitmap_set), 30);
+ pre_expr_pool = create_alloc_pool ("pre_expr nodes",
+ sizeof (struct pre_expr_d), 30);
+ FOR_ALL_BB (bb)
+ {
+ EXP_GEN (bb) = bitmap_set_new ();
+ PHI_GEN (bb) = bitmap_set_new ();
+ TMP_GEN (bb) = bitmap_set_new ();
+ AVAIL_OUT (bb) = bitmap_set_new ();
+ }
+
+ need_eh_cleanup = BITMAP_ALLOC (NULL);
+}
+
+
+/* Deallocate data structures used by PRE. */
+
+static void
+fini_pre (bool do_fre)
+{
+ basic_block bb;
+
+ free (postorder);
+ VEC_free (bitmap_set_t, heap, value_expressions);
+ VEC_free (gimple, heap, inserted_exprs);
+ VEC_free (gimple, heap, need_creation);
+ bitmap_obstack_release (&grand_bitmap_obstack);
+ free_alloc_pool (bitmap_set_pool);
+ free_alloc_pool (pre_expr_pool);
+ htab_delete (phi_translate_table);
+ htab_delete (expression_to_id);
+
+ FOR_ALL_BB (bb)
+ {
+ free (bb->aux);
+ bb->aux = NULL;
+ }
+
+ free_dominance_info (CDI_POST_DOMINATORS);
+
+ if (!bitmap_empty_p (need_eh_cleanup))
+ {
+ gimple_purge_all_dead_eh_edges (need_eh_cleanup);
+ cleanup_tree_cfg ();
+ }
+
+ BITMAP_FREE (need_eh_cleanup);
+
+ if (!do_fre)
+ loop_optimizer_finalize ();
+}
+
+/* Main entry point to the SSA-PRE pass. DO_FRE is true if the caller
+ only wants to do full redundancy elimination. */
+
+static unsigned int
+execute_pre (bool do_fre ATTRIBUTE_UNUSED)
+{
+ unsigned int todo = 0;
+
+ do_partial_partial = optimize > 2;
+
+ /* This has to happen before SCCVN runs because
+ loop_optimizer_init may create new phis, etc. */
+ if (!do_fre)
+ loop_optimizer_init (LOOPS_NORMAL);
+
+ if (!run_scc_vn (do_fre))
+ {
+ if (!do_fre)
+ {
+ remove_dead_inserted_code ();
+ loop_optimizer_finalize ();
+ }
+
+ return 0;
+ }
+ init_pre (do_fre);
+
+
+ /* Collect and value number expressions computed in each basic block. */
+ compute_avail ();
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ basic_block bb;
+
+ FOR_ALL_BB (bb)
+ {
+ print_bitmap_set (dump_file, EXP_GEN (bb), "exp_gen", bb->index);
+ print_bitmap_set (dump_file, PHI_GEN (bb), "phi_gen", bb->index);
+ print_bitmap_set (dump_file, TMP_GEN (bb), "tmp_gen", bb->index);
+ print_bitmap_set (dump_file, AVAIL_OUT (bb), "avail_out", bb->index);
+ }
+ }
+
+ /* Insert can get quite slow on an incredibly large number of basic
+ blocks due to some quadratic behavior. Until this behavior is
+ fixed, don't run it when he have an incredibly large number of
+ bb's. If we aren't going to run insert, there is no point in
+ computing ANTIC, either, even though it's plenty fast. */
+ if (!do_fre && n_basic_blocks < 4000)
+ {
+ compute_antic ();
+ insert ();
+ }
+
+ /* Remove all the redundant expressions. */
+ todo |= eliminate ();
+
+ statistics_counter_event (cfun, "Insertions", pre_stats.insertions);
+ statistics_counter_event (cfun, "PA inserted", pre_stats.pa_insert);
+ statistics_counter_event (cfun, "New PHIs", pre_stats.phis);
+ statistics_counter_event (cfun, "Eliminated", pre_stats.eliminations);
+ statistics_counter_event (cfun, "Constified", pre_stats.constified);
+
+ /* Make sure to remove fake edges before committing our inserts.
+ This makes sure we don't end up with extra critical edges that
+ we would need to split. */
+ remove_fake_exit_edges ();
+ gsi_commit_edge_inserts ();
+
+ clear_expression_ids ();
+ free_scc_vn ();
+ if (!do_fre)
+ remove_dead_inserted_code ();
+
+ fini_pre (do_fre);
+
+ return todo;
+}
+
+/* Gate and execute functions for PRE. */
+
+static unsigned int
+do_pre (void)
+{
+ return TODO_rebuild_alias | execute_pre (false);
+}
+
+static bool
+gate_pre (void)
+{
+ /* PRE tends to generate bigger code. */
+ return flag_tree_pre != 0 && optimize_function_for_speed_p (cfun);
+}
+
+struct gimple_opt_pass pass_pre =
+{
+ {
+ GIMPLE_PASS,
+ "pre", /* name */
+ gate_pre, /* gate */
+ do_pre, /* execute */
+ NULL, /* sub */
+ NULL, /* next */
+ 0, /* static_pass_number */
+ TV_TREE_PRE, /* tv_id */
+ PROP_no_crit_edges | PROP_cfg
+ | PROP_ssa | PROP_alias, /* properties_required */
+ 0, /* properties_provided */
+ 0, /* properties_destroyed */
+ 0, /* todo_flags_start */
+ TODO_update_ssa_only_virtuals | TODO_dump_func | TODO_ggc_collect
+ | TODO_verify_ssa /* todo_flags_finish */
+ }
+};
+
+
+/* Gate and execute functions for FRE. */
+
+static unsigned int
+execute_fre (void)
+{
+ return execute_pre (true);
+}
+
+static bool
+gate_fre (void)
+{
+ return flag_tree_fre != 0;
+}
+
+struct gimple_opt_pass pass_fre =
+{
+ {
+ GIMPLE_PASS,
+ "fre", /* name */
+ gate_fre, /* gate */
+ execute_fre, /* execute */
+ NULL, /* sub */
+ NULL, /* next */
+ 0, /* static_pass_number */
+ TV_TREE_FRE, /* tv_id */
+ PROP_cfg | PROP_ssa | PROP_alias, /* properties_required */
+ 0, /* properties_provided */
+ 0, /* properties_destroyed */
+ 0, /* todo_flags_start */
+ TODO_dump_func | TODO_ggc_collect | TODO_verify_ssa /* todo_flags_finish */
+ }
+};
projects / msp430-gcc.git / blobdiff