--- /dev/null
+/* SCC value numbering for trees
+ Copyright (C) 2006, 2007, 2008, 2009
+ Free Software Foundation, Inc.
+ Contributed by Daniel Berlin <dan@dberlin.org>
+
+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 "tree-pass.h"
+#include "flags.h"
+#include "bitmap.h"
+#include "langhooks.h"
+#include "cfgloop.h"
+#include "params.h"
+#include "tree-ssa-propagate.h"
+#include "tree-ssa-sccvn.h"
+
+/* This algorithm is based on the SCC algorithm presented by Keith
+ Cooper and L. Taylor Simpson in "SCC-Based Value numbering"
+ (http://citeseer.ist.psu.edu/41805.html). In
+ straight line code, it is equivalent to a regular hash based value
+ numbering that is performed in reverse postorder.
+
+ For code with cycles, there are two alternatives, both of which
+ require keeping the hashtables separate from the actual list of
+ value numbers for SSA names.
+
+ 1. Iterate value numbering in an RPO walk of the blocks, removing
+ all the entries from the hashtable after each iteration (but
+ keeping the SSA name->value number mapping between iterations).
+ Iterate until it does not change.
+
+ 2. Perform value numbering as part of an SCC walk on the SSA graph,
+ iterating only the cycles in the SSA graph until they do not change
+ (using a separate, optimistic hashtable for value numbering the SCC
+ operands).
+
+ The second is not just faster in practice (because most SSA graph
+ cycles do not involve all the variables in the graph), it also has
+ some nice properties.
+
+ One of these nice properties is that when we pop an SCC off the
+ stack, we are guaranteed to have processed all the operands coming from
+ *outside of that SCC*, so we do not need to do anything special to
+ ensure they have value numbers.
+
+ Another nice property is that the SCC walk is done as part of a DFS
+ of the SSA graph, which makes it easy to perform combining and
+ simplifying operations at the same time.
+
+ The code below is deliberately written in a way that makes it easy
+ to separate the SCC walk from the other work it does.
+
+ In order to propagate constants through the code, we track which
+ expressions contain constants, and use those while folding. In
+ theory, we could also track expressions whose value numbers are
+ replaced, in case we end up folding based on expression
+ identities.
+
+ In order to value number memory, we assign value numbers to vuses.
+ This enables us to note that, for example, stores to the same
+ address of the same value from the same starting memory states are
+ equivalent.
+ TODO:
+
+ 1. We can iterate only the changing portions of the SCC's, but
+ I have not seen an SCC big enough for this to be a win.
+ 2. If you differentiate between phi nodes for loops and phi nodes
+ for if-then-else, you can properly consider phi nodes in different
+ blocks for equivalence.
+ 3. We could value number vuses in more cases, particularly, whole
+ structure copies.
+*/
+
+/* The set of hashtables and alloc_pool's for their items. */
+
+typedef struct vn_tables_s
+{
+ htab_t nary;
+ htab_t phis;
+ htab_t references;
+ struct obstack nary_obstack;
+ alloc_pool phis_pool;
+ alloc_pool references_pool;
+} *vn_tables_t;
+
+static htab_t constant_to_value_id;
+static bitmap constant_value_ids;
+
+
+/* Valid hashtables storing information we have proven to be
+ correct. */
+
+static vn_tables_t valid_info;
+
+/* Optimistic hashtables storing information we are making assumptions about
+ during iterations. */
+
+static vn_tables_t optimistic_info;
+
+/* Pointer to the set of hashtables that is currently being used.
+ Should always point to either the optimistic_info, or the
+ valid_info. */
+
+static vn_tables_t current_info;
+
+
+/* Reverse post order index for each basic block. */
+
+static int *rpo_numbers;
+
+#define SSA_VAL(x) (VN_INFO ((x))->valnum)
+
+/* This represents the top of the VN lattice, which is the universal
+ value. */
+
+tree VN_TOP;
+
+/* Unique counter for our value ids. */
+
+static unsigned int next_value_id;
+
+/* Next DFS number and the stack for strongly connected component
+ detection. */
+
+static unsigned int next_dfs_num;
+static VEC (tree, heap) *sccstack;
+
+static bool may_insert;
+
+
+DEF_VEC_P(vn_ssa_aux_t);
+DEF_VEC_ALLOC_P(vn_ssa_aux_t, heap);
+
+/* Table of vn_ssa_aux_t's, one per ssa_name. The vn_ssa_aux_t objects
+ are allocated on an obstack for locality reasons, and to free them
+ without looping over the VEC. */
+
+static VEC (vn_ssa_aux_t, heap) *vn_ssa_aux_table;
+static struct obstack vn_ssa_aux_obstack;
+
+/* Return the value numbering information for a given SSA name. */
+
+vn_ssa_aux_t
+VN_INFO (tree name)
+{
+ vn_ssa_aux_t res = VEC_index (vn_ssa_aux_t, vn_ssa_aux_table,
+ SSA_NAME_VERSION (name));
+ gcc_assert (res);
+ return res;
+}
+
+/* Set the value numbering info for a given SSA name to a given
+ value. */
+
+static inline void
+VN_INFO_SET (tree name, vn_ssa_aux_t value)
+{
+ VEC_replace (vn_ssa_aux_t, vn_ssa_aux_table,
+ SSA_NAME_VERSION (name), value);
+}
+
+/* Initialize the value numbering info for a given SSA name.
+ This should be called just once for every SSA name. */
+
+vn_ssa_aux_t
+VN_INFO_GET (tree name)
+{
+ vn_ssa_aux_t newinfo;
+
+ newinfo = XOBNEW (&vn_ssa_aux_obstack, struct vn_ssa_aux);
+ memset (newinfo, 0, sizeof (struct vn_ssa_aux));
+ if (SSA_NAME_VERSION (name) >= VEC_length (vn_ssa_aux_t, vn_ssa_aux_table))
+ VEC_safe_grow (vn_ssa_aux_t, heap, vn_ssa_aux_table,
+ SSA_NAME_VERSION (name) + 1);
+ VEC_replace (vn_ssa_aux_t, vn_ssa_aux_table,
+ SSA_NAME_VERSION (name), newinfo);
+ return newinfo;
+}
+
+
+/* Get the representative expression for the SSA_NAME NAME. Returns
+ the representative SSA_NAME if there is no expression associated with it. */
+
+tree
+vn_get_expr_for (tree name)
+{
+ vn_ssa_aux_t vn = VN_INFO (name);
+ gimple def_stmt;
+ tree expr = NULL_TREE;
+
+ if (vn->valnum == VN_TOP)
+ return name;
+
+ /* If the value-number is a constant it is the representative
+ expression. */
+ if (TREE_CODE (vn->valnum) != SSA_NAME)
+ return vn->valnum;
+
+ /* Get to the information of the value of this SSA_NAME. */
+ vn = VN_INFO (vn->valnum);
+
+ /* If the value-number is a constant it is the representative
+ expression. */
+ if (TREE_CODE (vn->valnum) != SSA_NAME)
+ return vn->valnum;
+
+ /* Else if we have an expression, return it. */
+ if (vn->expr != NULL_TREE)
+ return vn->expr;
+
+ /* Otherwise use the defining statement to build the expression. */
+ def_stmt = SSA_NAME_DEF_STMT (vn->valnum);
+
+ /* If the value number is a default-definition or a PHI result
+ use it directly. */
+ if (gimple_nop_p (def_stmt)
+ || gimple_code (def_stmt) == GIMPLE_PHI)
+ return vn->valnum;
+
+ if (!is_gimple_assign (def_stmt))
+ return vn->valnum;
+
+ /* FIXME tuples. This is incomplete and likely will miss some
+ simplifications. */
+ switch (TREE_CODE_CLASS (gimple_assign_rhs_code (def_stmt)))
+ {
+ case tcc_reference:
+ if ((gimple_assign_rhs_code (def_stmt) == VIEW_CONVERT_EXPR
+ || gimple_assign_rhs_code (def_stmt) == REALPART_EXPR
+ || gimple_assign_rhs_code (def_stmt) == IMAGPART_EXPR)
+ && TREE_CODE (gimple_assign_rhs1 (def_stmt)) == SSA_NAME)
+ expr = fold_build1 (gimple_assign_rhs_code (def_stmt),
+ gimple_expr_type (def_stmt),
+ TREE_OPERAND (gimple_assign_rhs1 (def_stmt), 0));
+ break;
+
+ case tcc_unary:
+ expr = fold_build1 (gimple_assign_rhs_code (def_stmt),
+ gimple_expr_type (def_stmt),
+ gimple_assign_rhs1 (def_stmt));
+ break;
+
+ case tcc_binary:
+ expr = fold_build2 (gimple_assign_rhs_code (def_stmt),
+ gimple_expr_type (def_stmt),
+ gimple_assign_rhs1 (def_stmt),
+ gimple_assign_rhs2 (def_stmt));
+ break;
+
+ default:;
+ }
+ if (expr == NULL_TREE)
+ return vn->valnum;
+
+ /* Cache the expression. */
+ vn->expr = expr;
+
+ return expr;
+}
+
+
+/* Free a phi operation structure VP. */
+
+static void
+free_phi (void *vp)
+{
+ vn_phi_t phi = (vn_phi_t) vp;
+ VEC_free (tree, heap, phi->phiargs);
+}
+
+/* Free a reference operation structure VP. */
+
+static void
+free_reference (void *vp)
+{
+ vn_reference_t vr = (vn_reference_t) vp;
+ VEC_free (vn_reference_op_s, heap, vr->operands);
+}
+
+/* Hash table equality function for vn_constant_t. */
+
+static int
+vn_constant_eq (const void *p1, const void *p2)
+{
+ const struct vn_constant_s *vc1 = (const struct vn_constant_s *) p1;
+ const struct vn_constant_s *vc2 = (const struct vn_constant_s *) p2;
+
+ if (vc1->hashcode != vc2->hashcode)
+ return false;
+
+ return vn_constant_eq_with_type (vc1->constant, vc2->constant);
+}
+
+/* Hash table hash function for vn_constant_t. */
+
+static hashval_t
+vn_constant_hash (const void *p1)
+{
+ const struct vn_constant_s *vc1 = (const struct vn_constant_s *) p1;
+ return vc1->hashcode;
+}
+
+/* Lookup a value id for CONSTANT and return it. If it does not
+ exist returns 0. */
+
+unsigned int
+get_constant_value_id (tree constant)
+{
+ void **slot;
+ struct vn_constant_s vc;
+
+ vc.hashcode = vn_hash_constant_with_type (constant);
+ vc.constant = constant;
+ slot = htab_find_slot_with_hash (constant_to_value_id, &vc,
+ vc.hashcode, NO_INSERT);
+ if (slot)
+ return ((vn_constant_t)*slot)->value_id;
+ return 0;
+}
+
+/* Lookup a value id for CONSTANT, and if it does not exist, create a
+ new one and return it. If it does exist, return it. */
+
+unsigned int
+get_or_alloc_constant_value_id (tree constant)
+{
+ void **slot;
+ vn_constant_t vc = XNEW (struct vn_constant_s);
+
+ vc->hashcode = vn_hash_constant_with_type (constant);
+ vc->constant = constant;
+ slot = htab_find_slot_with_hash (constant_to_value_id, vc,
+ vc->hashcode, INSERT);
+ if (*slot)
+ {
+ free (vc);
+ return ((vn_constant_t)*slot)->value_id;
+ }
+ vc->value_id = get_next_value_id ();
+ *slot = vc;
+ bitmap_set_bit (constant_value_ids, vc->value_id);
+ return vc->value_id;
+}
+
+/* Return true if V is a value id for a constant. */
+
+bool
+value_id_constant_p (unsigned int v)
+{
+ return bitmap_bit_p (constant_value_ids, v);
+}
+
+/* Compare two reference operands P1 and P2 for equality. Return true if
+ they are equal, and false otherwise. */
+
+static int
+vn_reference_op_eq (const void *p1, const void *p2)
+{
+ const_vn_reference_op_t const vro1 = (const_vn_reference_op_t) p1;
+ const_vn_reference_op_t const vro2 = (const_vn_reference_op_t) p2;
+
+ return vro1->opcode == vro2->opcode
+ && types_compatible_p (vro1->type, vro2->type)
+ && expressions_equal_p (vro1->op0, vro2->op0)
+ && expressions_equal_p (vro1->op1, vro2->op1)
+ && expressions_equal_p (vro1->op2, vro2->op2);
+}
+
+/* Compute the hash for a reference operand VRO1. */
+
+static hashval_t
+vn_reference_op_compute_hash (const vn_reference_op_t vro1)
+{
+ hashval_t result = 0;
+ if (vro1->op0)
+ result += iterative_hash_expr (vro1->op0, vro1->opcode);
+ if (vro1->op1)
+ result += iterative_hash_expr (vro1->op1, vro1->opcode);
+ if (vro1->op2)
+ result += iterative_hash_expr (vro1->op2, vro1->opcode);
+ return result;
+}
+
+/* Return the hashcode for a given reference operation P1. */
+
+static hashval_t
+vn_reference_hash (const void *p1)
+{
+ const_vn_reference_t const vr1 = (const_vn_reference_t) p1;
+ return vr1->hashcode;
+}
+
+/* Compute a hash for the reference operation VR1 and return it. */
+
+hashval_t
+vn_reference_compute_hash (const vn_reference_t vr1)
+{
+ hashval_t result = 0;
+ tree v;
+ int i;
+ vn_reference_op_t vro;
+
+ for (i = 0; VEC_iterate (tree, vr1->vuses, i, v); i++)
+ result += iterative_hash_expr (v, 0);
+ for (i = 0; VEC_iterate (vn_reference_op_s, vr1->operands, i, vro); i++)
+ result += vn_reference_op_compute_hash (vro);
+
+ return result;
+}
+
+/* Return true if reference operations P1 and P2 are equivalent. This
+ means they have the same set of operands and vuses. */
+
+int
+vn_reference_eq (const void *p1, const void *p2)
+{
+ tree v;
+ int i;
+ vn_reference_op_t vro;
+
+ const_vn_reference_t const vr1 = (const_vn_reference_t) p1;
+ const_vn_reference_t const vr2 = (const_vn_reference_t) p2;
+ if (vr1->hashcode != vr2->hashcode)
+ return false;
+
+ if (vr1->vuses == vr2->vuses
+ && vr1->operands == vr2->operands)
+ return true;
+
+ /* Impossible for them to be equivalent if they have different
+ number of vuses. */
+ if (VEC_length (tree, vr1->vuses) != VEC_length (tree, vr2->vuses))
+ return false;
+
+ /* We require that address operands be canonicalized in a way that
+ two memory references will have the same operands if they are
+ equivalent. */
+ if (VEC_length (vn_reference_op_s, vr1->operands)
+ != VEC_length (vn_reference_op_s, vr2->operands))
+ return false;
+
+ /* The memory state is more often different than the address of the
+ store/load, so check it first. */
+ for (i = 0; VEC_iterate (tree, vr1->vuses, i, v); i++)
+ {
+ if (VEC_index (tree, vr2->vuses, i) != v)
+ return false;
+ }
+
+ for (i = 0; VEC_iterate (vn_reference_op_s, vr1->operands, i, vro); i++)
+ {
+ if (!vn_reference_op_eq (VEC_index (vn_reference_op_s, vr2->operands, i),
+ vro))
+ return false;
+ }
+ return true;
+}
+
+/* Place the vuses from STMT into *result. */
+
+static inline void
+vuses_to_vec (gimple stmt, VEC (tree, gc) **result)
+{
+ ssa_op_iter iter;
+ tree vuse;
+
+ if (!stmt)
+ return;
+
+ VEC_reserve_exact (tree, gc, *result,
+ num_ssa_operands (stmt, SSA_OP_VIRTUAL_USES));
+
+ FOR_EACH_SSA_TREE_OPERAND (vuse, stmt, iter, SSA_OP_VIRTUAL_USES)
+ VEC_quick_push (tree, *result, vuse);
+}
+
+
+/* Copy the VUSE names in STMT into a vector, and return
+ the vector. */
+
+static VEC (tree, gc) *
+copy_vuses_from_stmt (gimple stmt)
+{
+ VEC (tree, gc) *vuses = NULL;
+
+ vuses_to_vec (stmt, &vuses);
+
+ return vuses;
+}
+
+/* Place the vdefs from STMT into *result. */
+
+static inline void
+vdefs_to_vec (gimple stmt, VEC (tree, gc) **result)
+{
+ ssa_op_iter iter;
+ tree vdef;
+
+ if (!stmt)
+ return;
+
+ *result = VEC_alloc (tree, gc, num_ssa_operands (stmt, SSA_OP_VIRTUAL_DEFS));
+
+ FOR_EACH_SSA_TREE_OPERAND (vdef, stmt, iter, SSA_OP_VIRTUAL_DEFS)
+ VEC_quick_push (tree, *result, vdef);
+}
+
+/* Copy the names of vdef results in STMT into a vector, and return
+ the vector. */
+
+static VEC (tree, gc) *
+copy_vdefs_from_stmt (gimple stmt)
+{
+ VEC (tree, gc) *vdefs = NULL;
+
+ vdefs_to_vec (stmt, &vdefs);
+
+ return vdefs;
+}
+
+/* Place for shared_v{uses/defs}_from_stmt to shove vuses/vdefs. */
+static VEC (tree, gc) *shared_lookup_vops;
+
+/* Copy the virtual uses from STMT into SHARED_LOOKUP_VOPS.
+ This function will overwrite the current SHARED_LOOKUP_VOPS
+ variable. */
+
+VEC (tree, gc) *
+shared_vuses_from_stmt (gimple stmt)
+{
+ VEC_truncate (tree, shared_lookup_vops, 0);
+ vuses_to_vec (stmt, &shared_lookup_vops);
+
+ return shared_lookup_vops;
+}
+
+/* Copy the operations present in load/store REF into RESULT, a vector of
+ vn_reference_op_s's. */
+
+void
+copy_reference_ops_from_ref (tree ref, VEC(vn_reference_op_s, heap) **result)
+{
+ if (TREE_CODE (ref) == TARGET_MEM_REF)
+ {
+ vn_reference_op_s temp;
+
+ memset (&temp, 0, sizeof (temp));
+ /* We do not care for spurious type qualifications. */
+ temp.type = TYPE_MAIN_VARIANT (TREE_TYPE (ref));
+ temp.opcode = TREE_CODE (ref);
+ temp.op0 = TMR_SYMBOL (ref) ? TMR_SYMBOL (ref) : TMR_BASE (ref);
+ temp.op1 = TMR_INDEX (ref);
+ VEC_safe_push (vn_reference_op_s, heap, *result, &temp);
+
+ memset (&temp, 0, sizeof (temp));
+ temp.type = NULL_TREE;
+ temp.opcode = TREE_CODE (ref);
+ temp.op0 = TMR_STEP (ref);
+ temp.op1 = TMR_OFFSET (ref);
+ VEC_safe_push (vn_reference_op_s, heap, *result, &temp);
+ return;
+ }
+
+ /* For non-calls, store the information that makes up the address. */
+
+ while (ref)
+ {
+ vn_reference_op_s temp;
+
+ memset (&temp, 0, sizeof (temp));
+ /* We do not care for spurious type qualifications. */
+ temp.type = TYPE_MAIN_VARIANT (TREE_TYPE (ref));
+ temp.opcode = TREE_CODE (ref);
+
+ switch (temp.opcode)
+ {
+ case ALIGN_INDIRECT_REF:
+ case INDIRECT_REF:
+ /* The only operand is the address, which gets its own
+ vn_reference_op_s structure. */
+ break;
+ case MISALIGNED_INDIRECT_REF:
+ temp.op0 = TREE_OPERAND (ref, 1);
+ break;
+ case BIT_FIELD_REF:
+ /* Record bits and position. */
+ temp.op0 = TREE_OPERAND (ref, 1);
+ temp.op1 = TREE_OPERAND (ref, 2);
+ break;
+ case COMPONENT_REF:
+ /* The field decl is enough to unambiguously specify the field,
+ a matching type is not necessary and a mismatching type
+ is always a spurious difference. */
+ temp.type = NULL_TREE;
+ /* If this is a reference to a union member, record the union
+ member size as operand. Do so only if we are doing
+ expression insertion (during FRE), as PRE currently gets
+ confused with this. */
+ if (may_insert
+ && TREE_OPERAND (ref, 2) == NULL_TREE
+ && TREE_CODE (DECL_CONTEXT (TREE_OPERAND (ref, 1))) == UNION_TYPE
+ && integer_zerop (DECL_FIELD_OFFSET (TREE_OPERAND (ref, 1)))
+ && integer_zerop (DECL_FIELD_BIT_OFFSET (TREE_OPERAND (ref, 1))))
+ temp.op0 = TYPE_SIZE (TREE_TYPE (TREE_OPERAND (ref, 1)));
+ else
+ {
+ /* Record field as operand. */
+ temp.op0 = TREE_OPERAND (ref, 1);
+ temp.op1 = TREE_OPERAND (ref, 2);
+ }
+ break;
+ case ARRAY_RANGE_REF:
+ case ARRAY_REF:
+ /* Record index as operand. */
+ temp.op0 = TREE_OPERAND (ref, 1);
+ temp.op1 = TREE_OPERAND (ref, 2);
+ temp.op2 = TREE_OPERAND (ref, 3);
+ break;
+ 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 SSA_NAME:
+ temp.op0 = ref;
+ break;
+ case ADDR_EXPR:
+ if (is_gimple_min_invariant (ref))
+ {
+ temp.op0 = ref;
+ break;
+ }
+ /* Fallthrough. */
+ /* These are only interesting for their operands, their
+ existence, and their type. They will never be the last
+ ref in the chain of references (IE they require an
+ operand), so we don't have to put anything
+ for op* as it will be handled by the iteration */
+ case IMAGPART_EXPR:
+ case REALPART_EXPR:
+ case VIEW_CONVERT_EXPR:
+ break;
+ default:
+ gcc_unreachable ();
+ }
+ VEC_safe_push (vn_reference_op_s, heap, *result, &temp);
+
+ if (REFERENCE_CLASS_P (ref)
+ || (TREE_CODE (ref) == ADDR_EXPR
+ && !is_gimple_min_invariant (ref)))
+ ref = TREE_OPERAND (ref, 0);
+ else
+ ref = NULL_TREE;
+ }
+}
+
+/* Re-create a reference tree from the reference ops OPS.
+ Returns NULL_TREE if the ops were not handled.
+ This routine needs to be kept in sync with copy_reference_ops_from_ref. */
+
+static tree
+get_ref_from_reference_ops (VEC(vn_reference_op_s, heap) *ops)
+{
+ vn_reference_op_t op;
+ unsigned i;
+ tree ref, *op0_p = &ref;
+
+ for (i = 0; VEC_iterate (vn_reference_op_s, ops, i, op); ++i)
+ {
+ switch (op->opcode)
+ {
+ case CALL_EXPR:
+ return NULL_TREE;
+
+ case ALIGN_INDIRECT_REF:
+ case INDIRECT_REF:
+ *op0_p = build1 (op->opcode, op->type, NULL_TREE);
+ op0_p = &TREE_OPERAND (*op0_p, 0);
+ break;
+
+ case MISALIGNED_INDIRECT_REF:
+ *op0_p = build2 (MISALIGNED_INDIRECT_REF, op->type,
+ NULL_TREE, op->op0);
+ op0_p = &TREE_OPERAND (*op0_p, 0);
+ break;
+
+ case BIT_FIELD_REF:
+ *op0_p = build3 (BIT_FIELD_REF, op->type, NULL_TREE,
+ op->op0, op->op1);
+ op0_p = &TREE_OPERAND (*op0_p, 0);
+ break;
+
+ case COMPONENT_REF:
+ *op0_p = build3 (COMPONENT_REF, TREE_TYPE (op->op0), NULL_TREE,
+ op->op0, op->op1);
+ op0_p = &TREE_OPERAND (*op0_p, 0);
+ break;
+
+ case ARRAY_RANGE_REF:
+ case ARRAY_REF:
+ *op0_p = build4 (op->opcode, op->type, NULL_TREE,
+ op->op0, op->op1, op->op2);
+ op0_p = &TREE_OPERAND (*op0_p, 0);
+ break;
+
+ 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 SSA_NAME:
+ *op0_p = op->op0;
+ break;
+
+ case ADDR_EXPR:
+ if (op->op0 != NULL_TREE)
+ {
+ gcc_assert (is_gimple_min_invariant (op->op0));
+ *op0_p = op->op0;
+ break;
+ }
+ /* Fallthrough. */
+ case IMAGPART_EXPR:
+ case REALPART_EXPR:
+ case VIEW_CONVERT_EXPR:
+ *op0_p = build1 (op->opcode, op->type, NULL_TREE);
+ op0_p = &TREE_OPERAND (*op0_p, 0);
+ break;
+
+ default:
+ return NULL_TREE;
+ }
+ }
+
+ return ref;
+}
+
+/* Copy the operations present in load/store/call REF into RESULT, a vector of
+ vn_reference_op_s's. */
+
+void
+copy_reference_ops_from_call (gimple call,
+ VEC(vn_reference_op_s, heap) **result)
+{
+ vn_reference_op_s temp;
+ unsigned i;
+
+ /* Copy the type, opcode, function being called and static chain. */
+ memset (&temp, 0, sizeof (temp));
+ temp.type = gimple_call_return_type (call);
+ temp.opcode = CALL_EXPR;
+ temp.op0 = gimple_call_fn (call);
+ temp.op1 = gimple_call_chain (call);
+ VEC_safe_push (vn_reference_op_s, heap, *result, &temp);
+
+ /* Copy the call arguments. As they can be references as well,
+ just chain them together. */
+ for (i = 0; i < gimple_call_num_args (call); ++i)
+ {
+ tree callarg = gimple_call_arg (call, i);
+ copy_reference_ops_from_ref (callarg, result);
+ }
+}
+
+/* Create a vector of vn_reference_op_s structures from REF, a
+ REFERENCE_CLASS_P tree. The vector is not shared. */
+
+static VEC(vn_reference_op_s, heap) *
+create_reference_ops_from_ref (tree ref)
+{
+ VEC (vn_reference_op_s, heap) *result = NULL;
+
+ copy_reference_ops_from_ref (ref, &result);
+ return result;
+}
+
+/* Create a vector of vn_reference_op_s structures from CALL, a
+ call statement. The vector is not shared. */
+
+static VEC(vn_reference_op_s, heap) *
+create_reference_ops_from_call (gimple call)
+{
+ VEC (vn_reference_op_s, heap) *result = NULL;
+
+ copy_reference_ops_from_call (call, &result);
+ return result;
+}
+
+static VEC(vn_reference_op_s, heap) *shared_lookup_references;
+
+/* Create a vector of vn_reference_op_s structures from REF, a
+ REFERENCE_CLASS_P tree. The vector is shared among all callers of
+ this function. */
+
+static VEC(vn_reference_op_s, heap) *
+shared_reference_ops_from_ref (tree ref)
+{
+ if (!ref)
+ return NULL;
+ VEC_truncate (vn_reference_op_s, shared_lookup_references, 0);
+ copy_reference_ops_from_ref (ref, &shared_lookup_references);
+ return shared_lookup_references;
+}
+
+/* Create a vector of vn_reference_op_s structures from CALL, a
+ call statement. The vector is shared among all callers of
+ this function. */
+
+static VEC(vn_reference_op_s, heap) *
+shared_reference_ops_from_call (gimple call)
+{
+ if (!call)
+ return NULL;
+ VEC_truncate (vn_reference_op_s, shared_lookup_references, 0);
+ copy_reference_ops_from_call (call, &shared_lookup_references);
+ return shared_lookup_references;
+}
+
+
+/* Transform any SSA_NAME's in a vector of vn_reference_op_s
+ structures into their value numbers. This is done in-place, and
+ the vector passed in is returned. */
+
+static VEC (vn_reference_op_s, heap) *
+valueize_refs (VEC (vn_reference_op_s, heap) *orig)
+{
+ vn_reference_op_t vro;
+ int i;
+
+ for (i = 0; VEC_iterate (vn_reference_op_s, orig, i, vro); i++)
+ {
+ if (vro->opcode == SSA_NAME
+ || (vro->op0 && TREE_CODE (vro->op0) == SSA_NAME))
+ {
+ vro->op0 = SSA_VAL (vro->op0);
+ /* If it transforms from an SSA_NAME to a constant, update
+ the opcode. */
+ if (TREE_CODE (vro->op0) != SSA_NAME && vro->opcode == SSA_NAME)
+ vro->opcode = TREE_CODE (vro->op0);
+ }
+ /* TODO: Do we want to valueize op2 and op1 of
+ ARRAY_REF/COMPONENT_REF for Ada */
+
+ }
+
+ return orig;
+}
+
+/* Transform any SSA_NAME's in ORIG, a vector of vuse trees, into
+ their value numbers. This is done in-place, and the vector passed
+ in is returned. */
+
+static VEC (tree, gc) *
+valueize_vuses (VEC (tree, gc) *orig)
+{
+ bool made_replacement = false;
+ tree vuse;
+ int i;
+
+ for (i = 0; VEC_iterate (tree, orig, i, vuse); i++)
+ {
+ if (vuse != SSA_VAL (vuse))
+ {
+ made_replacement = true;
+ VEC_replace (tree, orig, i, SSA_VAL (vuse));
+ }
+ }
+
+ if (made_replacement && VEC_length (tree, orig) > 1)
+ sort_vuses (orig);
+
+ return orig;
+}
+
+/* Return the single reference statement defining all virtual uses
+ in VUSES or NULL_TREE, if there are multiple defining statements.
+ Take into account only definitions that alias REF if following
+ back-edges. */
+
+static gimple
+get_def_ref_stmt_vuses (tree ref, VEC (tree, gc) *vuses)
+{
+ gimple def_stmt;
+ tree vuse;
+ unsigned int i;
+
+ gcc_assert (VEC_length (tree, vuses) >= 1);
+
+ def_stmt = SSA_NAME_DEF_STMT (VEC_index (tree, vuses, 0));
+ if (gimple_code (def_stmt) == GIMPLE_PHI)
+ {
+ /* We can only handle lookups over PHI nodes for a single
+ virtual operand. */
+ if (VEC_length (tree, vuses) == 1)
+ {
+ def_stmt = get_single_def_stmt_from_phi (ref, def_stmt);
+ goto cont;
+ }
+ else
+ return NULL;
+ }
+
+ /* Verify each VUSE reaches the same defining stmt. */
+ for (i = 1; VEC_iterate (tree, vuses, i, vuse); ++i)
+ {
+ gimple tmp = SSA_NAME_DEF_STMT (vuse);
+ if (tmp != def_stmt)
+ return NULL;
+ }
+
+ /* Now see if the definition aliases ref, and loop until it does. */
+cont:
+ while (def_stmt
+ && is_gimple_assign (def_stmt)
+ && !refs_may_alias_p (ref, gimple_get_lhs (def_stmt)))
+ def_stmt = get_single_def_stmt_with_phi (ref, def_stmt);
+
+ return def_stmt;
+}
+
+/* Lookup a SCCVN reference operation VR in the current hash table.
+ Returns the resulting value number if it exists in the hash table,
+ NULL_TREE otherwise. VNRESULT will be filled in with the actual
+ vn_reference_t stored in the hashtable if something is found. */
+
+static tree
+vn_reference_lookup_1 (vn_reference_t vr, vn_reference_t *vnresult)
+{
+ void **slot;
+ hashval_t hash;
+
+ hash = vr->hashcode;
+ slot = htab_find_slot_with_hash (current_info->references, vr,
+ hash, NO_INSERT);
+ if (!slot && current_info == optimistic_info)
+ slot = htab_find_slot_with_hash (valid_info->references, vr,
+ hash, NO_INSERT);
+ if (slot)
+ {
+ if (vnresult)
+ *vnresult = (vn_reference_t)*slot;
+ return ((vn_reference_t)*slot)->result;
+ }
+
+ return NULL_TREE;
+}
+
+
+/* Lookup a reference operation by it's parts, in the current hash table.
+ Returns the resulting value number if it exists in the hash table,
+ NULL_TREE otherwise. VNRESULT will be filled in with the actual
+ vn_reference_t stored in the hashtable if something is found. */
+
+tree
+vn_reference_lookup_pieces (VEC (tree, gc) *vuses,
+ VEC (vn_reference_op_s, heap) *operands,
+ vn_reference_t *vnresult, bool maywalk)
+{
+ struct vn_reference_s vr1;
+ tree result;
+ if (vnresult)
+ *vnresult = NULL;
+
+ vr1.vuses = valueize_vuses (vuses);
+ vr1.operands = valueize_refs (operands);
+ vr1.hashcode = vn_reference_compute_hash (&vr1);
+ result = vn_reference_lookup_1 (&vr1, vnresult);
+
+ /* If there is a single defining statement for all virtual uses, we can
+ use that, following virtual use-def chains. */
+ if (!result
+ && maywalk
+ && vr1.vuses
+ && VEC_length (tree, vr1.vuses) >= 1)
+ {
+ tree ref = get_ref_from_reference_ops (operands);
+ gimple def_stmt;
+ if (ref
+ && (def_stmt = get_def_ref_stmt_vuses (ref, vr1.vuses))
+ && is_gimple_assign (def_stmt))
+ {
+ /* We are now at an aliasing definition for the vuses we want to
+ look up. Re-do the lookup with the vdefs for this stmt. */
+ vdefs_to_vec (def_stmt, &vuses);
+ vr1.vuses = valueize_vuses (vuses);
+ vr1.hashcode = vn_reference_compute_hash (&vr1);
+ result = vn_reference_lookup_1 (&vr1, vnresult);
+ }
+ }
+
+ return result;
+}
+
+/* Lookup OP in the current hash table, and return the resulting value
+ number if it exists in the hash table. Return NULL_TREE if it does
+ not exist in the hash table or if the result field of the structure
+ was NULL.. VNRESULT will be filled in with the vn_reference_t
+ stored in the hashtable if one exists. */
+
+tree
+vn_reference_lookup (tree op, VEC (tree, gc) *vuses, bool maywalk,
+ vn_reference_t *vnresult)
+{
+ struct vn_reference_s vr1;
+ tree result;
+ gimple def_stmt;
+ if (vnresult)
+ *vnresult = NULL;
+
+ vr1.vuses = valueize_vuses (vuses);
+ vr1.operands = valueize_refs (shared_reference_ops_from_ref (op));
+ vr1.hashcode = vn_reference_compute_hash (&vr1);
+ result = vn_reference_lookup_1 (&vr1, vnresult);
+
+ /* If there is a single defining statement for all virtual uses, we can
+ use that, following virtual use-def chains. */
+ if (!result
+ && maywalk
+ && vr1.vuses
+ && VEC_length (tree, vr1.vuses) >= 1
+ && (def_stmt = get_def_ref_stmt_vuses (op, vr1.vuses))
+ && is_gimple_assign (def_stmt))
+ {
+ /* We are now at an aliasing definition for the vuses we want to
+ look up. Re-do the lookup with the vdefs for this stmt. */
+ vdefs_to_vec (def_stmt, &vuses);
+ vr1.vuses = valueize_vuses (vuses);
+ vr1.hashcode = vn_reference_compute_hash (&vr1);
+ result = vn_reference_lookup_1 (&vr1, vnresult);
+ }
+
+ return result;
+}
+
+
+/* Insert OP into the current hash table with a value number of
+ RESULT, and return the resulting reference structure we created. */
+
+vn_reference_t
+vn_reference_insert (tree op, tree result, VEC (tree, gc) *vuses)
+{
+ void **slot;
+ vn_reference_t vr1;
+
+ vr1 = (vn_reference_t) pool_alloc (current_info->references_pool);
+ if (TREE_CODE (result) == SSA_NAME)
+ vr1->value_id = VN_INFO (result)->value_id;
+ else
+ vr1->value_id = get_or_alloc_constant_value_id (result);
+ vr1->vuses = valueize_vuses (vuses);
+ vr1->operands = valueize_refs (create_reference_ops_from_ref (op));
+ vr1->hashcode = vn_reference_compute_hash (vr1);
+ vr1->result = TREE_CODE (result) == SSA_NAME ? SSA_VAL (result) : result;
+
+ slot = htab_find_slot_with_hash (current_info->references, vr1, vr1->hashcode,
+ INSERT);
+
+ /* Because we lookup stores using vuses, and value number failures
+ using the vdefs (see visit_reference_op_store for how and why),
+ it's possible that on failure we may try to insert an already
+ inserted store. This is not wrong, there is no ssa name for a
+ store that we could use as a differentiator anyway. Thus, unlike
+ the other lookup functions, you cannot gcc_assert (!*slot)
+ here. */
+
+ /* But free the old slot in case of a collision. */
+ if (*slot)
+ free_reference (*slot);
+
+ *slot = vr1;
+ return vr1;
+}
+
+/* Insert a reference by it's pieces into the current hash table with
+ a value number of RESULT. Return the resulting reference
+ structure we created. */
+
+vn_reference_t
+vn_reference_insert_pieces (VEC (tree, gc) *vuses,
+ VEC (vn_reference_op_s, heap) *operands,
+ tree result, unsigned int value_id)
+
+{
+ void **slot;
+ vn_reference_t vr1;
+
+ vr1 = (vn_reference_t) pool_alloc (current_info->references_pool);
+ vr1->value_id = value_id;
+ vr1->vuses = valueize_vuses (vuses);
+ vr1->operands = valueize_refs (operands);
+ vr1->hashcode = vn_reference_compute_hash (vr1);
+ if (result && TREE_CODE (result) == SSA_NAME)
+ result = SSA_VAL (result);
+ vr1->result = result;
+
+ slot = htab_find_slot_with_hash (current_info->references, vr1, vr1->hashcode,
+ INSERT);
+
+ /* At this point we should have all the things inserted that we have
+ seen before, and we should never try inserting something that
+ already exists. */
+ gcc_assert (!*slot);
+ if (*slot)
+ free_reference (*slot);
+
+ *slot = vr1;
+ return vr1;
+}
+
+/* Compute and return the hash value for nary operation VBO1. */
+
+inline hashval_t
+vn_nary_op_compute_hash (const vn_nary_op_t vno1)
+{
+ hashval_t hash = 0;
+ unsigned i;
+
+ for (i = 0; i < vno1->length; ++i)
+ if (TREE_CODE (vno1->op[i]) == SSA_NAME)
+ vno1->op[i] = SSA_VAL (vno1->op[i]);
+
+ if (vno1->length == 2
+ && commutative_tree_code (vno1->opcode)
+ && tree_swap_operands_p (vno1->op[0], vno1->op[1], false))
+ {
+ tree temp = vno1->op[0];
+ vno1->op[0] = vno1->op[1];
+ vno1->op[1] = temp;
+ }
+
+ for (i = 0; i < vno1->length; ++i)
+ hash += iterative_hash_expr (vno1->op[i], vno1->opcode);
+
+ return hash;
+}
+
+/* Return the computed hashcode for nary operation P1. */
+
+static hashval_t
+vn_nary_op_hash (const void *p1)
+{
+ const_vn_nary_op_t const vno1 = (const_vn_nary_op_t) p1;
+ return vno1->hashcode;
+}
+
+/* Compare nary operations P1 and P2 and return true if they are
+ equivalent. */
+
+int
+vn_nary_op_eq (const void *p1, const void *p2)
+{
+ const_vn_nary_op_t const vno1 = (const_vn_nary_op_t) p1;
+ const_vn_nary_op_t const vno2 = (const_vn_nary_op_t) p2;
+ unsigned i;
+
+ if (vno1->hashcode != vno2->hashcode)
+ return false;
+
+ if (vno1->opcode != vno2->opcode
+ || !types_compatible_p (vno1->type, vno2->type))
+ return false;
+
+ for (i = 0; i < vno1->length; ++i)
+ if (!expressions_equal_p (vno1->op[i], vno2->op[i]))
+ return false;
+
+ return true;
+}
+
+/* Lookup a n-ary operation by its pieces and return the resulting value
+ number if it exists in the hash table. Return NULL_TREE if it does
+ not exist in the hash table or if the result field of the operation
+ is NULL. VNRESULT will contain the vn_nary_op_t from the hashtable
+ if it exists. */
+
+tree
+vn_nary_op_lookup_pieces (unsigned int length, enum tree_code code,
+ tree type, tree op0, tree op1, tree op2,
+ tree op3, vn_nary_op_t *vnresult)
+{
+ void **slot;
+ struct vn_nary_op_s vno1;
+ if (vnresult)
+ *vnresult = NULL;
+ vno1.opcode = code;
+ vno1.length = length;
+ vno1.type = type;
+ vno1.op[0] = op0;
+ vno1.op[1] = op1;
+ vno1.op[2] = op2;
+ vno1.op[3] = op3;
+ vno1.hashcode = vn_nary_op_compute_hash (&vno1);
+ slot = htab_find_slot_with_hash (current_info->nary, &vno1, vno1.hashcode,
+ NO_INSERT);
+ if (!slot && current_info == optimistic_info)
+ slot = htab_find_slot_with_hash (valid_info->nary, &vno1, vno1.hashcode,
+ NO_INSERT);
+ if (!slot)
+ return NULL_TREE;
+ if (vnresult)
+ *vnresult = (vn_nary_op_t)*slot;
+ return ((vn_nary_op_t)*slot)->result;
+}
+
+/* Lookup OP in the current hash table, and return the resulting value
+ number if it exists in the hash table. Return NULL_TREE if it does
+ not exist in the hash table or if the result field of the operation
+ is NULL. VNRESULT will contain the vn_nary_op_t from the hashtable
+ if it exists. */
+
+tree
+vn_nary_op_lookup (tree op, vn_nary_op_t *vnresult)
+{
+ void **slot;
+ struct vn_nary_op_s vno1;
+ unsigned i;
+
+ if (vnresult)
+ *vnresult = NULL;
+ vno1.opcode = TREE_CODE (op);
+ vno1.length = TREE_CODE_LENGTH (TREE_CODE (op));
+ vno1.type = TREE_TYPE (op);
+ for (i = 0; i < vno1.length; ++i)
+ vno1.op[i] = TREE_OPERAND (op, i);
+ vno1.hashcode = vn_nary_op_compute_hash (&vno1);
+ slot = htab_find_slot_with_hash (current_info->nary, &vno1, vno1.hashcode,
+ NO_INSERT);
+ if (!slot && current_info == optimistic_info)
+ slot = htab_find_slot_with_hash (valid_info->nary, &vno1, vno1.hashcode,
+ NO_INSERT);
+ if (!slot)
+ return NULL_TREE;
+ if (vnresult)
+ *vnresult = (vn_nary_op_t)*slot;
+ return ((vn_nary_op_t)*slot)->result;
+}
+
+/* Lookup the rhs of STMT in the current hash table, and return the resulting
+ value number if it exists in the hash table. Return NULL_TREE if
+ it does not exist in the hash table. VNRESULT will contain the
+ vn_nary_op_t from the hashtable if it exists. */
+
+tree
+vn_nary_op_lookup_stmt (gimple stmt, vn_nary_op_t *vnresult)
+{
+ void **slot;
+ struct vn_nary_op_s vno1;
+ unsigned i;
+
+ if (vnresult)
+ *vnresult = NULL;
+ vno1.opcode = gimple_assign_rhs_code (stmt);
+ vno1.length = gimple_num_ops (stmt) - 1;
+ vno1.type = gimple_expr_type (stmt);
+ for (i = 0; i < vno1.length; ++i)
+ vno1.op[i] = gimple_op (stmt, i + 1);
+ if (vno1.opcode == REALPART_EXPR
+ || vno1.opcode == IMAGPART_EXPR
+ || vno1.opcode == VIEW_CONVERT_EXPR)
+ vno1.op[0] = TREE_OPERAND (vno1.op[0], 0);
+ vno1.hashcode = vn_nary_op_compute_hash (&vno1);
+ slot = htab_find_slot_with_hash (current_info->nary, &vno1, vno1.hashcode,
+ NO_INSERT);
+ if (!slot && current_info == optimistic_info)
+ slot = htab_find_slot_with_hash (valid_info->nary, &vno1, vno1.hashcode,
+ NO_INSERT);
+ if (!slot)
+ return NULL_TREE;
+ if (vnresult)
+ *vnresult = (vn_nary_op_t)*slot;
+ return ((vn_nary_op_t)*slot)->result;
+}
+
+/* Insert a n-ary operation into the current hash table using it's
+ pieces. Return the vn_nary_op_t structure we created and put in
+ the hashtable. */
+
+vn_nary_op_t
+vn_nary_op_insert_pieces (unsigned int length, enum tree_code code,
+ tree type, tree op0,
+ tree op1, tree op2, tree op3,
+ tree result,
+ unsigned int value_id)
+{
+ void **slot;
+ vn_nary_op_t vno1;
+
+ vno1 = (vn_nary_op_t) obstack_alloc (¤t_info->nary_obstack,
+ (sizeof (struct vn_nary_op_s)
+ - sizeof (tree) * (4 - length)));
+ vno1->value_id = value_id;
+ vno1->opcode = code;
+ vno1->length = length;
+ vno1->type = type;
+ if (length >= 1)
+ vno1->op[0] = op0;
+ if (length >= 2)
+ vno1->op[1] = op1;
+ if (length >= 3)
+ vno1->op[2] = op2;
+ if (length >= 4)
+ vno1->op[3] = op3;
+ vno1->result = result;
+ vno1->hashcode = vn_nary_op_compute_hash (vno1);
+ slot = htab_find_slot_with_hash (current_info->nary, vno1, vno1->hashcode,
+ INSERT);
+ gcc_assert (!*slot);
+
+ *slot = vno1;
+ return vno1;
+
+}
+
+/* Insert OP into the current hash table with a value number of
+ RESULT. Return the vn_nary_op_t structure we created and put in
+ the hashtable. */
+
+vn_nary_op_t
+vn_nary_op_insert (tree op, tree result)
+{
+ unsigned length = TREE_CODE_LENGTH (TREE_CODE (op));
+ void **slot;
+ vn_nary_op_t vno1;
+ unsigned i;
+
+ vno1 = (vn_nary_op_t) obstack_alloc (¤t_info->nary_obstack,
+ (sizeof (struct vn_nary_op_s)
+ - sizeof (tree) * (4 - length)));
+ vno1->value_id = VN_INFO (result)->value_id;
+ vno1->opcode = TREE_CODE (op);
+ vno1->length = length;
+ vno1->type = TREE_TYPE (op);
+ for (i = 0; i < vno1->length; ++i)
+ vno1->op[i] = TREE_OPERAND (op, i);
+ vno1->result = result;
+ vno1->hashcode = vn_nary_op_compute_hash (vno1);
+ slot = htab_find_slot_with_hash (current_info->nary, vno1, vno1->hashcode,
+ INSERT);
+ gcc_assert (!*slot);
+
+ *slot = vno1;
+ return vno1;
+}
+
+/* Insert the rhs of STMT into the current hash table with a value number of
+ RESULT. */
+
+vn_nary_op_t
+vn_nary_op_insert_stmt (gimple stmt, tree result)
+{
+ unsigned length = gimple_num_ops (stmt) - 1;
+ void **slot;
+ vn_nary_op_t vno1;
+ unsigned i;
+
+ vno1 = (vn_nary_op_t) obstack_alloc (¤t_info->nary_obstack,
+ (sizeof (struct vn_nary_op_s)
+ - sizeof (tree) * (4 - length)));
+ vno1->value_id = VN_INFO (result)->value_id;
+ vno1->opcode = gimple_assign_rhs_code (stmt);
+ vno1->length = length;
+ vno1->type = gimple_expr_type (stmt);
+ for (i = 0; i < vno1->length; ++i)
+ vno1->op[i] = gimple_op (stmt, i + 1);
+ if (vno1->opcode == REALPART_EXPR
+ || vno1->opcode == IMAGPART_EXPR
+ || vno1->opcode == VIEW_CONVERT_EXPR)
+ vno1->op[0] = TREE_OPERAND (vno1->op[0], 0);
+ vno1->result = result;
+ vno1->hashcode = vn_nary_op_compute_hash (vno1);
+ slot = htab_find_slot_with_hash (current_info->nary, vno1, vno1->hashcode,
+ INSERT);
+ gcc_assert (!*slot);
+
+ *slot = vno1;
+ return vno1;
+}
+
+/* Compute a hashcode for PHI operation VP1 and return it. */
+
+static inline hashval_t
+vn_phi_compute_hash (vn_phi_t vp1)
+{
+ hashval_t result = 0;
+ int i;
+ tree phi1op;
+ tree type;
+
+ result = vp1->block->index;
+
+ /* If all PHI arguments are constants we need to distinguish
+ the PHI node via its type. */
+ type = TREE_TYPE (VEC_index (tree, vp1->phiargs, 0));
+ result += (INTEGRAL_TYPE_P (type)
+ + (INTEGRAL_TYPE_P (type)
+ ? TYPE_PRECISION (type) + TYPE_UNSIGNED (type) : 0));
+
+ for (i = 0; VEC_iterate (tree, vp1->phiargs, i, phi1op); i++)
+ {
+ if (phi1op == VN_TOP)
+ continue;
+ result += iterative_hash_expr (phi1op, result);
+ }
+
+ return result;
+}
+
+/* Return the computed hashcode for phi operation P1. */
+
+static hashval_t
+vn_phi_hash (const void *p1)
+{
+ const_vn_phi_t const vp1 = (const_vn_phi_t) p1;
+ return vp1->hashcode;
+}
+
+/* Compare two phi entries for equality, ignoring VN_TOP arguments. */
+
+static int
+vn_phi_eq (const void *p1, const void *p2)
+{
+ const_vn_phi_t const vp1 = (const_vn_phi_t) p1;
+ const_vn_phi_t const vp2 = (const_vn_phi_t) p2;
+
+ if (vp1->hashcode != vp2->hashcode)
+ return false;
+
+ if (vp1->block == vp2->block)
+ {
+ int i;
+ tree phi1op;
+
+ /* If the PHI nodes do not have compatible types
+ they are not the same. */
+ if (!types_compatible_p (TREE_TYPE (VEC_index (tree, vp1->phiargs, 0)),
+ TREE_TYPE (VEC_index (tree, vp2->phiargs, 0))))
+ return false;
+
+ /* Any phi in the same block will have it's arguments in the
+ same edge order, because of how we store phi nodes. */
+ for (i = 0; VEC_iterate (tree, vp1->phiargs, i, phi1op); i++)
+ {
+ tree phi2op = VEC_index (tree, vp2->phiargs, i);
+ if (phi1op == VN_TOP || phi2op == VN_TOP)
+ continue;
+ if (!expressions_equal_p (phi1op, phi2op))
+ return false;
+ }
+ return true;
+ }
+ return false;
+}
+
+static VEC(tree, heap) *shared_lookup_phiargs;
+
+/* Lookup PHI in the current hash table, and return the resulting
+ value number if it exists in the hash table. Return NULL_TREE if
+ it does not exist in the hash table. */
+
+static tree
+vn_phi_lookup (gimple phi)
+{
+ void **slot;
+ struct vn_phi_s vp1;
+ unsigned i;
+
+ VEC_truncate (tree, shared_lookup_phiargs, 0);
+
+ /* Canonicalize the SSA_NAME's to their value number. */
+ for (i = 0; i < gimple_phi_num_args (phi); i++)
+ {
+ tree def = PHI_ARG_DEF (phi, i);
+ def = TREE_CODE (def) == SSA_NAME ? SSA_VAL (def) : def;
+ VEC_safe_push (tree, heap, shared_lookup_phiargs, def);
+ }
+ vp1.phiargs = shared_lookup_phiargs;
+ vp1.block = gimple_bb (phi);
+ vp1.hashcode = vn_phi_compute_hash (&vp1);
+ slot = htab_find_slot_with_hash (current_info->phis, &vp1, vp1.hashcode,
+ NO_INSERT);
+ if (!slot && current_info == optimistic_info)
+ slot = htab_find_slot_with_hash (valid_info->phis, &vp1, vp1.hashcode,
+ NO_INSERT);
+ if (!slot)
+ return NULL_TREE;
+ return ((vn_phi_t)*slot)->result;
+}
+
+/* Insert PHI into the current hash table with a value number of
+ RESULT. */
+
+static vn_phi_t
+vn_phi_insert (gimple phi, tree result)
+{
+ void **slot;
+ vn_phi_t vp1 = (vn_phi_t) pool_alloc (current_info->phis_pool);
+ unsigned i;
+ VEC (tree, heap) *args = NULL;
+
+ /* Canonicalize the SSA_NAME's to their value number. */
+ for (i = 0; i < gimple_phi_num_args (phi); i++)
+ {
+ tree def = PHI_ARG_DEF (phi, i);
+ def = TREE_CODE (def) == SSA_NAME ? SSA_VAL (def) : def;
+ VEC_safe_push (tree, heap, args, def);
+ }
+ vp1->value_id = VN_INFO (result)->value_id;
+ vp1->phiargs = args;
+ vp1->block = gimple_bb (phi);
+ vp1->result = result;
+ vp1->hashcode = vn_phi_compute_hash (vp1);
+
+ slot = htab_find_slot_with_hash (current_info->phis, vp1, vp1->hashcode,
+ INSERT);
+
+ /* Because we iterate over phi operations more than once, it's
+ possible the slot might already exist here, hence no assert.*/
+ *slot = vp1;
+ return vp1;
+}
+
+
+/* Print set of components in strongly connected component SCC to OUT. */
+
+static void
+print_scc (FILE *out, VEC (tree, heap) *scc)
+{
+ tree var;
+ unsigned int i;
+
+ fprintf (out, "SCC consists of: ");
+ for (i = 0; VEC_iterate (tree, scc, i, var); i++)
+ {
+ print_generic_expr (out, var, 0);
+ fprintf (out, " ");
+ }
+ fprintf (out, "\n");
+}
+
+/* Set the value number of FROM to TO, return true if it has changed
+ as a result. */
+
+static inline bool
+set_ssa_val_to (tree from, tree to)
+{
+ tree currval;
+
+ if (from != to
+ && TREE_CODE (to) == SSA_NAME
+ && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (to))
+ to = from;
+
+ /* The only thing we allow as value numbers are VN_TOP, ssa_names
+ and invariants. So assert that here. */
+ gcc_assert (to != NULL_TREE
+ && (to == VN_TOP
+ || TREE_CODE (to) == SSA_NAME
+ || is_gimple_min_invariant (to)));
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Setting value number of ");
+ print_generic_expr (dump_file, from, 0);
+ fprintf (dump_file, " to ");
+ print_generic_expr (dump_file, to, 0);
+ }
+
+ currval = SSA_VAL (from);
+
+ if (currval != to && !operand_equal_p (currval, to, OEP_PURE_SAME))
+ {
+ SSA_VAL (from) = to;
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, " (changed)\n");
+ return true;
+ }
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "\n");
+ return false;
+}
+
+/* Set all definitions in STMT to value number to themselves.
+ Return true if a value number changed. */
+
+static bool
+defs_to_varying (gimple stmt)
+{
+ bool changed = false;
+ ssa_op_iter iter;
+ def_operand_p defp;
+
+ FOR_EACH_SSA_DEF_OPERAND (defp, stmt, iter, SSA_OP_ALL_DEFS)
+ {
+ tree def = DEF_FROM_PTR (defp);
+
+ VN_INFO (def)->use_processed = true;
+ changed |= set_ssa_val_to (def, def);
+ }
+ return changed;
+}
+
+static bool expr_has_constants (tree expr);
+static tree valueize_expr (tree expr);
+
+/* Visit a copy between LHS and RHS, return true if the value number
+ changed. */
+
+static bool
+visit_copy (tree lhs, tree rhs)
+{
+ /* Follow chains of copies to their destination. */
+ while (TREE_CODE (rhs) == SSA_NAME
+ && SSA_VAL (rhs) != rhs)
+ rhs = SSA_VAL (rhs);
+
+ /* The copy may have a more interesting constant filled expression
+ (we don't, since we know our RHS is just an SSA name). */
+ if (TREE_CODE (rhs) == SSA_NAME)
+ {
+ VN_INFO (lhs)->has_constants = VN_INFO (rhs)->has_constants;
+ VN_INFO (lhs)->expr = VN_INFO (rhs)->expr;
+ }
+
+ return set_ssa_val_to (lhs, rhs);
+}
+
+/* Visit a unary operator RHS, value number it, and return true if the
+ value number of LHS has changed as a result. */
+
+static bool
+visit_unary_op (tree lhs, gimple stmt)
+{
+ bool changed = false;
+ tree result = vn_nary_op_lookup_stmt (stmt, NULL);
+
+ if (result)
+ {
+ changed = set_ssa_val_to (lhs, result);
+ }
+ else
+ {
+ changed = set_ssa_val_to (lhs, lhs);
+ vn_nary_op_insert_stmt (stmt, lhs);
+ }
+
+ return changed;
+}
+
+/* Visit a binary operator RHS, value number it, and return true if the
+ value number of LHS has changed as a result. */
+
+static bool
+visit_binary_op (tree lhs, gimple stmt)
+{
+ bool changed = false;
+ tree result = vn_nary_op_lookup_stmt (stmt, NULL);
+
+ if (result)
+ {
+ changed = set_ssa_val_to (lhs, result);
+ }
+ else
+ {
+ changed = set_ssa_val_to (lhs, lhs);
+ vn_nary_op_insert_stmt (stmt, lhs);
+ }
+
+ return changed;
+}
+
+/* Visit a call STMT storing into LHS. Return true if the value number
+ of the LHS has changed as a result. */
+
+static bool
+visit_reference_op_call (tree lhs, gimple stmt)
+{
+ bool changed = false;
+ struct vn_reference_s vr1;
+ tree result;
+
+ vr1.vuses = valueize_vuses (shared_vuses_from_stmt (stmt));
+ vr1.operands = valueize_refs (shared_reference_ops_from_call (stmt));
+ vr1.hashcode = vn_reference_compute_hash (&vr1);
+ result = vn_reference_lookup_1 (&vr1, NULL);
+ if (result)
+ {
+ changed = set_ssa_val_to (lhs, result);
+ if (TREE_CODE (result) == SSA_NAME
+ && VN_INFO (result)->has_constants)
+ VN_INFO (lhs)->has_constants = true;
+ }
+ else
+ {
+ void **slot;
+ vn_reference_t vr2;
+ changed = set_ssa_val_to (lhs, lhs);
+ vr2 = (vn_reference_t) pool_alloc (current_info->references_pool);
+ vr2->vuses = valueize_vuses (copy_vuses_from_stmt (stmt));
+ vr2->operands = valueize_refs (create_reference_ops_from_call (stmt));
+ vr2->hashcode = vr1.hashcode;
+ vr2->result = lhs;
+ slot = htab_find_slot_with_hash (current_info->references,
+ vr2, vr2->hashcode, INSERT);
+ if (*slot)
+ free_reference (*slot);
+ *slot = vr2;
+ }
+
+ return changed;
+}
+
+/* Visit a load from a reference operator RHS, part of STMT, value number it,
+ and return true if the value number of the LHS has changed as a result. */
+
+static bool
+visit_reference_op_load (tree lhs, tree op, gimple stmt)
+{
+ bool changed = false;
+ tree result = vn_reference_lookup (op, shared_vuses_from_stmt (stmt), true,
+ NULL);
+
+ /* We handle type-punning through unions by value-numbering based
+ on offset and size of the access. Be prepared to handle a
+ type-mismatch here via creating a VIEW_CONVERT_EXPR. */
+ if (result
+ && !useless_type_conversion_p (TREE_TYPE (result), TREE_TYPE (op)))
+ {
+ /* We will be setting the value number of lhs to the value number
+ of VIEW_CONVERT_EXPR <TREE_TYPE (result)> (result).
+ So first simplify and lookup this expression to see if it
+ is already available. */
+ tree val = fold_build1 (VIEW_CONVERT_EXPR, TREE_TYPE (op), result);
+ if ((CONVERT_EXPR_P (val)
+ || TREE_CODE (val) == VIEW_CONVERT_EXPR)
+ && TREE_CODE (TREE_OPERAND (val, 0)) == SSA_NAME)
+ {
+ tree tem = valueize_expr (vn_get_expr_for (TREE_OPERAND (val, 0)));
+ if ((CONVERT_EXPR_P (tem)
+ || TREE_CODE (tem) == VIEW_CONVERT_EXPR)
+ && (tem = fold_unary_ignore_overflow (TREE_CODE (val),
+ TREE_TYPE (val), tem)))
+ val = tem;
+ }
+ result = val;
+ if (!is_gimple_min_invariant (val)
+ && TREE_CODE (val) != SSA_NAME)
+ result = vn_nary_op_lookup (val, NULL);
+ /* If the expression is not yet available, value-number lhs to
+ a new SSA_NAME we create. */
+ if (!result && may_insert)
+ {
+ result = make_ssa_name (SSA_NAME_VAR (lhs), NULL);
+ /* Initialize value-number information properly. */
+ VN_INFO_GET (result)->valnum = result;
+ VN_INFO (result)->value_id = get_next_value_id ();
+ VN_INFO (result)->expr = val;
+ VN_INFO (result)->has_constants = expr_has_constants (val);
+ VN_INFO (result)->needs_insertion = true;
+ /* As all "inserted" statements are singleton SCCs, insert
+ to the valid table. This is strictly needed to
+ avoid re-generating new value SSA_NAMEs for the same
+ expression during SCC iteration over and over (the
+ optimistic table gets cleared after each iteration).
+ We do not need to insert into the optimistic table, as
+ lookups there will fall back to the valid table. */
+ if (current_info == optimistic_info)
+ {
+ current_info = valid_info;
+ vn_nary_op_insert (val, result);
+ current_info = optimistic_info;
+ }
+ else
+ vn_nary_op_insert (val, result);
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Inserting name ");
+ print_generic_expr (dump_file, result, 0);
+ fprintf (dump_file, " for expression ");
+ print_generic_expr (dump_file, val, 0);
+ fprintf (dump_file, "\n");
+ }
+ }
+ }
+
+ if (result)
+ {
+ changed = set_ssa_val_to (lhs, result);
+ if (TREE_CODE (result) == SSA_NAME
+ && VN_INFO (result)->has_constants)
+ {
+ VN_INFO (lhs)->expr = VN_INFO (result)->expr;
+ VN_INFO (lhs)->has_constants = true;
+ }
+ }
+ else
+ {
+ changed = set_ssa_val_to (lhs, lhs);
+ vn_reference_insert (op, lhs, copy_vuses_from_stmt (stmt));
+ }
+
+ return changed;
+}
+
+
+/* Visit a store to a reference operator LHS, part of STMT, value number it,
+ and return true if the value number of the LHS has changed as a result. */
+
+static bool
+visit_reference_op_store (tree lhs, tree op, gimple stmt)
+{
+ bool changed = false;
+ tree result;
+ bool resultsame = false;
+
+ /* First we want to lookup using the *vuses* from the store and see
+ if there the last store to this location with the same address
+ had the same value.
+
+ The vuses represent the memory state before the store. If the
+ memory state, address, and value of the store is the same as the
+ last store to this location, then this store will produce the
+ same memory state as that store.
+
+ In this case the vdef versions for this store are value numbered to those
+ vuse versions, since they represent the same memory state after
+ this store.
+
+ Otherwise, the vdefs for the store are used when inserting into
+ the table, since the store generates a new memory state. */
+
+ result = vn_reference_lookup (lhs, shared_vuses_from_stmt (stmt), false,
+ NULL);
+
+ if (result)
+ {
+ if (TREE_CODE (result) == SSA_NAME)
+ result = SSA_VAL (result);
+ if (TREE_CODE (op) == SSA_NAME)
+ op = SSA_VAL (op);
+ resultsame = expressions_equal_p (result, op);
+ }
+
+ if (!result || !resultsame)
+ {
+ VEC(tree, gc) *vdefs = copy_vdefs_from_stmt (stmt);
+ int i;
+ tree vdef;
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "No store match\n");
+ fprintf (dump_file, "Value numbering store ");
+ print_generic_expr (dump_file, lhs, 0);
+ fprintf (dump_file, " to ");
+ print_generic_expr (dump_file, op, 0);
+ fprintf (dump_file, "\n");
+ }
+ /* Have to set value numbers before insert, since insert is
+ going to valueize the references in-place. */
+ for (i = 0; VEC_iterate (tree, vdefs, i, vdef); i++)
+ {
+ VN_INFO (vdef)->use_processed = true;
+ changed |= set_ssa_val_to (vdef, vdef);
+ }
+
+ /* Do not insert structure copies into the tables. */
+ if (is_gimple_min_invariant (op)
+ || is_gimple_reg (op))
+ vn_reference_insert (lhs, op, vdefs);
+ }
+ else
+ {
+ /* We had a match, so value number the vdefs to have the value
+ number of the vuses they came from. */
+ ssa_op_iter op_iter;
+ def_operand_p var;
+ vuse_vec_p vv;
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Store matched earlier value,"
+ "value numbering store vdefs to matching vuses.\n");
+
+ FOR_EACH_SSA_VDEF_OPERAND (var, vv, stmt, op_iter)
+ {
+ tree def = DEF_FROM_PTR (var);
+ tree use;
+
+ /* Uh, if the vuse is a multiuse, we can't really do much
+ here, sadly, since we don't know which value number of
+ which vuse to use. */
+ if (VUSE_VECT_NUM_ELEM (*vv) != 1)
+ use = def;
+ else
+ use = VUSE_ELEMENT_VAR (*vv, 0);
+
+ VN_INFO (def)->use_processed = true;
+ changed |= set_ssa_val_to (def, SSA_VAL (use));
+ }
+ }
+
+ return changed;
+}
+
+/* Visit and value number PHI, return true if the value number
+ changed. */
+
+static bool
+visit_phi (gimple phi)
+{
+ bool changed = false;
+ tree result;
+ tree sameval = VN_TOP;
+ bool allsame = true;
+ unsigned i;
+
+ /* TODO: We could check for this in init_sccvn, and replace this
+ with a gcc_assert. */
+ if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (PHI_RESULT (phi)))
+ return set_ssa_val_to (PHI_RESULT (phi), PHI_RESULT (phi));
+
+ /* See if all non-TOP arguments have the same value. TOP is
+ equivalent to everything, so we can ignore it. */
+ for (i = 0; i < gimple_phi_num_args (phi); i++)
+ {
+ tree def = PHI_ARG_DEF (phi, i);
+
+ if (TREE_CODE (def) == SSA_NAME)
+ def = SSA_VAL (def);
+ if (def == VN_TOP)
+ continue;
+ if (sameval == VN_TOP)
+ {
+ sameval = def;
+ }
+ else
+ {
+ if (!expressions_equal_p (def, sameval))
+ {
+ allsame = false;
+ break;
+ }
+ }
+ }
+
+ /* If all value numbered to the same value, the phi node has that
+ value. */
+ if (allsame)
+ {
+ if (is_gimple_min_invariant (sameval))
+ {
+ VN_INFO (PHI_RESULT (phi))->has_constants = true;
+ VN_INFO (PHI_RESULT (phi))->expr = sameval;
+ }
+ else
+ {
+ VN_INFO (PHI_RESULT (phi))->has_constants = false;
+ VN_INFO (PHI_RESULT (phi))->expr = sameval;
+ }
+
+ if (TREE_CODE (sameval) == SSA_NAME)
+ return visit_copy (PHI_RESULT (phi), sameval);
+
+ return set_ssa_val_to (PHI_RESULT (phi), sameval);
+ }
+
+ /* Otherwise, see if it is equivalent to a phi node in this block. */
+ result = vn_phi_lookup (phi);
+ if (result)
+ {
+ if (TREE_CODE (result) == SSA_NAME)
+ changed = visit_copy (PHI_RESULT (phi), result);
+ else
+ changed = set_ssa_val_to (PHI_RESULT (phi), result);
+ }
+ else
+ {
+ vn_phi_insert (phi, PHI_RESULT (phi));
+ VN_INFO (PHI_RESULT (phi))->has_constants = false;
+ VN_INFO (PHI_RESULT (phi))->expr = PHI_RESULT (phi);
+ changed = set_ssa_val_to (PHI_RESULT (phi), PHI_RESULT (phi));
+ }
+
+ return changed;
+}
+
+/* Return true if EXPR contains constants. */
+
+static bool
+expr_has_constants (tree expr)
+{
+ switch (TREE_CODE_CLASS (TREE_CODE (expr)))
+ {
+ case tcc_unary:
+ return is_gimple_min_invariant (TREE_OPERAND (expr, 0));
+
+ case tcc_binary:
+ return is_gimple_min_invariant (TREE_OPERAND (expr, 0))
+ || is_gimple_min_invariant (TREE_OPERAND (expr, 1));
+ /* Constants inside reference ops are rarely interesting, but
+ it can take a lot of looking to find them. */
+ case tcc_reference:
+ case tcc_declaration:
+ return false;
+ default:
+ return is_gimple_min_invariant (expr);
+ }
+ return false;
+}
+
+/* Return true if STMT contains constants. */
+
+static bool
+stmt_has_constants (gimple stmt)
+{
+ if (gimple_code (stmt) != GIMPLE_ASSIGN)
+ return false;
+
+ switch (get_gimple_rhs_class (gimple_assign_rhs_code (stmt)))
+ {
+ case GIMPLE_UNARY_RHS:
+ return is_gimple_min_invariant (gimple_assign_rhs1 (stmt));
+
+ case GIMPLE_BINARY_RHS:
+ return (is_gimple_min_invariant (gimple_assign_rhs1 (stmt))
+ || is_gimple_min_invariant (gimple_assign_rhs2 (stmt)));
+ case GIMPLE_SINGLE_RHS:
+ /* Constants inside reference ops are rarely interesting, but
+ it can take a lot of looking to find them. */
+ return is_gimple_min_invariant (gimple_assign_rhs1 (stmt));
+ default:
+ gcc_unreachable ();
+ }
+ return false;
+}
+
+/* Replace SSA_NAMES in expr with their value numbers, and return the
+ result.
+ This is performed in place. */
+
+static tree
+valueize_expr (tree expr)
+{
+ switch (TREE_CODE_CLASS (TREE_CODE (expr)))
+ {
+ case tcc_unary:
+ if (TREE_CODE (TREE_OPERAND (expr, 0)) == SSA_NAME
+ && SSA_VAL (TREE_OPERAND (expr, 0)) != VN_TOP)
+ TREE_OPERAND (expr, 0) = SSA_VAL (TREE_OPERAND (expr, 0));
+ break;
+ case tcc_binary:
+ if (TREE_CODE (TREE_OPERAND (expr, 0)) == SSA_NAME
+ && SSA_VAL (TREE_OPERAND (expr, 0)) != VN_TOP)
+ TREE_OPERAND (expr, 0) = SSA_VAL (TREE_OPERAND (expr, 0));
+ if (TREE_CODE (TREE_OPERAND (expr, 1)) == SSA_NAME
+ && SSA_VAL (TREE_OPERAND (expr, 1)) != VN_TOP)
+ TREE_OPERAND (expr, 1) = SSA_VAL (TREE_OPERAND (expr, 1));
+ break;
+ default:
+ break;
+ }
+ return expr;
+}
+
+/* Simplify the binary expression RHS, and return the result if
+ simplified. */
+
+static tree
+simplify_binary_expression (gimple stmt)
+{
+ tree result = NULL_TREE;
+ tree op0 = gimple_assign_rhs1 (stmt);
+ tree op1 = gimple_assign_rhs2 (stmt);
+
+ /* This will not catch every single case we could combine, but will
+ catch those with constants. The goal here is to simultaneously
+ combine constants between expressions, but avoid infinite
+ expansion of expressions during simplification. */
+ if (TREE_CODE (op0) == SSA_NAME)
+ {
+ if (VN_INFO (op0)->has_constants
+ || TREE_CODE_CLASS (gimple_assign_rhs_code (stmt)) == tcc_comparison)
+ op0 = valueize_expr (vn_get_expr_for (op0));
+ else if (SSA_VAL (op0) != VN_TOP && SSA_VAL (op0) != op0)
+ op0 = SSA_VAL (op0);
+ }
+
+ if (TREE_CODE (op1) == SSA_NAME)
+ {
+ if (VN_INFO (op1)->has_constants)
+ op1 = valueize_expr (vn_get_expr_for (op1));
+ else if (SSA_VAL (op1) != VN_TOP && SSA_VAL (op1) != op1)
+ op1 = SSA_VAL (op1);
+ }
+
+ /* Avoid folding if nothing changed. */
+ if (op0 == gimple_assign_rhs1 (stmt)
+ && op1 == gimple_assign_rhs2 (stmt))
+ return NULL_TREE;
+
+ fold_defer_overflow_warnings ();
+
+ result = fold_binary (gimple_assign_rhs_code (stmt),
+ gimple_expr_type (stmt), op0, op1);
+ if (result)
+ STRIP_USELESS_TYPE_CONVERSION (result);
+
+ fold_undefer_overflow_warnings (result && valid_gimple_rhs_p (result),
+ stmt, 0);
+
+ /* Make sure result is not a complex expression consisting
+ of operators of operators (IE (a + b) + (a + c))
+ Otherwise, we will end up with unbounded expressions if
+ fold does anything at all. */
+ if (result && valid_gimple_rhs_p (result))
+ return result;
+
+ return NULL_TREE;
+}
+
+/* Simplify the unary expression RHS, and return the result if
+ simplified. */
+
+static tree
+simplify_unary_expression (gimple stmt)
+{
+ tree result = NULL_TREE;
+ tree orig_op0, op0 = gimple_assign_rhs1 (stmt);
+
+ /* We handle some tcc_reference codes here that are all
+ GIMPLE_ASSIGN_SINGLE codes. */
+ if (gimple_assign_rhs_code (stmt) == REALPART_EXPR
+ || gimple_assign_rhs_code (stmt) == IMAGPART_EXPR
+ || gimple_assign_rhs_code (stmt) == VIEW_CONVERT_EXPR)
+ op0 = TREE_OPERAND (op0, 0);
+
+ if (TREE_CODE (op0) != SSA_NAME)
+ return NULL_TREE;
+
+ orig_op0 = op0;
+ if (VN_INFO (op0)->has_constants)
+ op0 = valueize_expr (vn_get_expr_for (op0));
+ else if (gimple_assign_cast_p (stmt)
+ || gimple_assign_rhs_code (stmt) == REALPART_EXPR
+ || gimple_assign_rhs_code (stmt) == IMAGPART_EXPR
+ || gimple_assign_rhs_code (stmt) == VIEW_CONVERT_EXPR)
+ {
+ /* We want to do tree-combining on conversion-like expressions.
+ Make sure we feed only SSA_NAMEs or constants to fold though. */
+ tree tem = valueize_expr (vn_get_expr_for (op0));
+ if (UNARY_CLASS_P (tem)
+ || BINARY_CLASS_P (tem)
+ || TREE_CODE (tem) == VIEW_CONVERT_EXPR
+ || TREE_CODE (tem) == SSA_NAME
+ || is_gimple_min_invariant (tem))
+ op0 = tem;
+ }
+
+ /* Avoid folding if nothing changed, but remember the expression. */
+ if (op0 == orig_op0)
+ return NULL_TREE;
+
+ result = fold_unary_ignore_overflow (gimple_assign_rhs_code (stmt),
+ gimple_expr_type (stmt), op0);
+ if (result)
+ {
+ STRIP_USELESS_TYPE_CONVERSION (result);
+ if (valid_gimple_rhs_p (result))
+ return result;
+ }
+
+ return NULL_TREE;
+}
+
+/* Try to simplify RHS using equivalences and constant folding. */
+
+static tree
+try_to_simplify (gimple stmt)
+{
+ tree tem;
+
+ /* For stores we can end up simplifying a SSA_NAME rhs. Just return
+ in this case, there is no point in doing extra work. */
+ if (gimple_assign_copy_p (stmt)
+ && TREE_CODE (gimple_assign_rhs1 (stmt)) == SSA_NAME)
+ return NULL_TREE;
+
+ switch (TREE_CODE_CLASS (gimple_assign_rhs_code (stmt)))
+ {
+ case tcc_declaration:
+ tem = get_symbol_constant_value (gimple_assign_rhs1 (stmt));
+ if (tem)
+ return tem;
+ break;
+
+ case tcc_reference:
+ /* Do not do full-blown reference lookup here, but simplify
+ reads from constant aggregates. */
+ tem = fold_const_aggregate_ref (gimple_assign_rhs1 (stmt));
+ if (tem)
+ return tem;
+
+ /* Fallthrough for some codes that can operate on registers. */
+ if (!(TREE_CODE (gimple_assign_rhs1 (stmt)) == REALPART_EXPR
+ || TREE_CODE (gimple_assign_rhs1 (stmt)) == IMAGPART_EXPR
+ || TREE_CODE (gimple_assign_rhs1 (stmt)) == VIEW_CONVERT_EXPR))
+ break;
+ /* We could do a little more with unary ops, if they expand
+ into binary ops, but it's debatable whether it is worth it. */
+ case tcc_unary:
+ return simplify_unary_expression (stmt);
+ break;
+ case tcc_comparison:
+ case tcc_binary:
+ return simplify_binary_expression (stmt);
+ break;
+ default:
+ break;
+ }
+
+ return NULL_TREE;
+}
+
+/* Visit and value number USE, return true if the value number
+ changed. */
+
+static bool
+visit_use (tree use)
+{
+ bool changed = false;
+ gimple stmt = SSA_NAME_DEF_STMT (use);
+
+ VN_INFO (use)->use_processed = true;
+
+ gcc_assert (!SSA_NAME_IN_FREE_LIST (use));
+ if (dump_file && (dump_flags & TDF_DETAILS)
+ && !SSA_NAME_IS_DEFAULT_DEF (use))
+ {
+ fprintf (dump_file, "Value numbering ");
+ print_generic_expr (dump_file, use, 0);
+ fprintf (dump_file, " stmt = ");
+ print_gimple_stmt (dump_file, stmt, 0, 0);
+ }
+
+ /* Handle uninitialized uses. */
+ if (SSA_NAME_IS_DEFAULT_DEF (use))
+ changed = set_ssa_val_to (use, use);
+ else
+ {
+ if (gimple_code (stmt) == GIMPLE_PHI)
+ changed = visit_phi (stmt);
+ else if (!gimple_has_lhs (stmt)
+ || gimple_has_volatile_ops (stmt)
+ || stmt_could_throw_p (stmt))
+ changed = defs_to_varying (stmt);
+ else if (is_gimple_assign (stmt))
+ {
+ tree lhs = gimple_assign_lhs (stmt);
+ tree simplified;
+
+ /* Shortcut for copies. Simplifying copies is pointless,
+ since we copy the expression and value they represent. */
+ if (gimple_assign_copy_p (stmt)
+ && TREE_CODE (gimple_assign_rhs1 (stmt)) == SSA_NAME
+ && TREE_CODE (lhs) == SSA_NAME)
+ {
+ changed = visit_copy (lhs, gimple_assign_rhs1 (stmt));
+ goto done;
+ }
+ simplified = try_to_simplify (stmt);
+ if (simplified)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "RHS ");
+ print_gimple_expr (dump_file, stmt, 0, 0);
+ fprintf (dump_file, " simplified to ");
+ print_generic_expr (dump_file, simplified, 0);
+ if (TREE_CODE (lhs) == SSA_NAME)
+ fprintf (dump_file, " has constants %d\n",
+ expr_has_constants (simplified));
+ else
+ fprintf (dump_file, "\n");
+ }
+ }
+ /* Setting value numbers to constants will occasionally
+ screw up phi congruence because constants are not
+ uniquely associated with a single ssa name that can be
+ looked up. */
+ if (simplified
+ && is_gimple_min_invariant (simplified)
+ && TREE_CODE (lhs) == SSA_NAME)
+ {
+ VN_INFO (lhs)->expr = simplified;
+ VN_INFO (lhs)->has_constants = true;
+ changed = set_ssa_val_to (lhs, simplified);
+ goto done;
+ }
+ else if (simplified
+ && TREE_CODE (simplified) == SSA_NAME
+ && TREE_CODE (lhs) == SSA_NAME)
+ {
+ changed = visit_copy (lhs, simplified);
+ goto done;
+ }
+ else if (simplified)
+ {
+ if (TREE_CODE (lhs) == SSA_NAME)
+ {
+ VN_INFO (lhs)->has_constants = expr_has_constants (simplified);
+ /* We have to unshare the expression or else
+ valuizing may change the IL stream. */
+ VN_INFO (lhs)->expr = unshare_expr (simplified);
+ }
+ }
+ else if (stmt_has_constants (stmt)
+ && TREE_CODE (lhs) == SSA_NAME)
+ VN_INFO (lhs)->has_constants = true;
+ else if (TREE_CODE (lhs) == SSA_NAME)
+ {
+ /* We reset expr and constantness here because we may
+ have been value numbering optimistically, and
+ iterating. They may become non-constant in this case,
+ even if they were optimistically constant. */
+
+ VN_INFO (lhs)->has_constants = false;
+ VN_INFO (lhs)->expr = NULL_TREE;
+ }
+
+ if ((TREE_CODE (lhs) == SSA_NAME
+ /* We can substitute SSA_NAMEs that are live over
+ abnormal edges with their constant value. */
+ && !(gimple_assign_copy_p (stmt)
+ && is_gimple_min_invariant (gimple_assign_rhs1 (stmt)))
+ && !(simplified
+ && is_gimple_min_invariant (simplified))
+ && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs))
+ /* Stores or copies from SSA_NAMEs that are live over
+ abnormal edges are a problem. */
+ || (gimple_assign_single_p (stmt)
+ && TREE_CODE (gimple_assign_rhs1 (stmt)) == SSA_NAME
+ && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (gimple_assign_rhs1 (stmt))))
+ changed = defs_to_varying (stmt);
+ else if (REFERENCE_CLASS_P (lhs) || DECL_P (lhs))
+ {
+ changed = visit_reference_op_store (lhs, gimple_assign_rhs1 (stmt), stmt);
+ }
+ else if (TREE_CODE (lhs) == SSA_NAME)
+ {
+ if ((gimple_assign_copy_p (stmt)
+ && is_gimple_min_invariant (gimple_assign_rhs1 (stmt)))
+ || (simplified
+ && is_gimple_min_invariant (simplified)))
+ {
+ VN_INFO (lhs)->has_constants = true;
+ if (simplified)
+ changed = set_ssa_val_to (lhs, simplified);
+ else
+ changed = set_ssa_val_to (lhs, gimple_assign_rhs1 (stmt));
+ }
+ else
+ {
+ switch (get_gimple_rhs_class (gimple_assign_rhs_code (stmt)))
+ {
+ case GIMPLE_UNARY_RHS:
+ changed = visit_unary_op (lhs, stmt);
+ break;
+ case GIMPLE_BINARY_RHS:
+ changed = visit_binary_op (lhs, stmt);
+ break;
+ case GIMPLE_SINGLE_RHS:
+ switch (TREE_CODE_CLASS (gimple_assign_rhs_code (stmt)))
+ {
+ case tcc_reference:
+ /* VOP-less references can go through unary case. */
+ if ((gimple_assign_rhs_code (stmt) == REALPART_EXPR
+ || gimple_assign_rhs_code (stmt) == IMAGPART_EXPR
+ || gimple_assign_rhs_code (stmt) == VIEW_CONVERT_EXPR )
+ && TREE_CODE (TREE_OPERAND (gimple_assign_rhs1 (stmt), 0)) == SSA_NAME)
+ {
+ changed = visit_unary_op (lhs, stmt);
+ break;
+ }
+ /* Fallthrough. */
+ case tcc_declaration:
+ changed = visit_reference_op_load
+ (lhs, gimple_assign_rhs1 (stmt), stmt);
+ break;
+ case tcc_expression:
+ if (gimple_assign_rhs_code (stmt) == ADDR_EXPR)
+ {
+ changed = visit_unary_op (lhs, stmt);
+ break;
+ }
+ /* Fallthrough. */
+ default:
+ changed = defs_to_varying (stmt);
+ }
+ break;
+ default:
+ changed = defs_to_varying (stmt);
+ break;
+ }
+ }
+ }
+ else
+ changed = defs_to_varying (stmt);
+ }
+ else if (is_gimple_call (stmt))
+ {
+ tree lhs = gimple_call_lhs (stmt);
+
+ /* ??? We could try to simplify calls. */
+
+ if (stmt_has_constants (stmt)
+ && TREE_CODE (lhs) == SSA_NAME)
+ VN_INFO (lhs)->has_constants = true;
+ else if (TREE_CODE (lhs) == SSA_NAME)
+ {
+ /* We reset expr and constantness here because we may
+ have been value numbering optimistically, and
+ iterating. They may become non-constant in this case,
+ even if they were optimistically constant. */
+ VN_INFO (lhs)->has_constants = false;
+ VN_INFO (lhs)->expr = NULL_TREE;
+ }
+
+ if (TREE_CODE (lhs) == SSA_NAME
+ && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs))
+ changed = defs_to_varying (stmt);
+ /* ??? We should handle stores from calls. */
+ else if (TREE_CODE (lhs) == SSA_NAME)
+ {
+ if (gimple_call_flags (stmt) & (ECF_PURE | ECF_CONST))
+ changed = visit_reference_op_call (lhs, stmt);
+ else
+ changed = defs_to_varying (stmt);
+ }
+ else
+ changed = defs_to_varying (stmt);
+ }
+ }
+ done:
+ return changed;
+}
+
+/* Compare two operands by reverse postorder index */
+
+static int
+compare_ops (const void *pa, const void *pb)
+{
+ const tree opa = *((const tree *)pa);
+ const tree opb = *((const tree *)pb);
+ gimple opstmta = SSA_NAME_DEF_STMT (opa);
+ gimple opstmtb = SSA_NAME_DEF_STMT (opb);
+ basic_block bba;
+ basic_block bbb;
+
+ if (gimple_nop_p (opstmta) && gimple_nop_p (opstmtb))
+ return 0;
+ else if (gimple_nop_p (opstmta))
+ return -1;
+ else if (gimple_nop_p (opstmtb))
+ return 1;
+
+ bba = gimple_bb (opstmta);
+ bbb = gimple_bb (opstmtb);
+
+ if (!bba && !bbb)
+ return 0;
+ else if (!bba)
+ return -1;
+ else if (!bbb)
+ return 1;
+
+ if (bba == bbb)
+ {
+ if (gimple_code (opstmta) == GIMPLE_PHI
+ && gimple_code (opstmtb) == GIMPLE_PHI)
+ return 0;
+ else if (gimple_code (opstmta) == GIMPLE_PHI)
+ return -1;
+ else if (gimple_code (opstmtb) == GIMPLE_PHI)
+ return 1;
+ return gimple_uid (opstmta) - gimple_uid (opstmtb);
+ }
+ return rpo_numbers[bba->index] - rpo_numbers[bbb->index];
+}
+
+/* Sort an array containing members of a strongly connected component
+ SCC so that the members are ordered by RPO number.
+ This means that when the sort is complete, iterating through the
+ array will give you the members in RPO order. */
+
+static void
+sort_scc (VEC (tree, heap) *scc)
+{
+ qsort (VEC_address (tree, scc),
+ VEC_length (tree, scc),
+ sizeof (tree),
+ compare_ops);
+}
+
+/* Process a strongly connected component in the SSA graph. */
+
+static void
+process_scc (VEC (tree, heap) *scc)
+{
+ /* If the SCC has a single member, just visit it. */
+
+ if (VEC_length (tree, scc) == 1)
+ {
+ tree use = VEC_index (tree, scc, 0);
+ if (!VN_INFO (use)->use_processed)
+ visit_use (use);
+ }
+ else
+ {
+ tree var;
+ unsigned int i;
+ unsigned int iterations = 0;
+ bool changed = true;
+
+ /* Iterate over the SCC with the optimistic table until it stops
+ changing. */
+ current_info = optimistic_info;
+ while (changed)
+ {
+ changed = false;
+ iterations++;
+ /* As we are value-numbering optimistically we have to
+ clear the expression tables and the simplified expressions
+ in each iteration until we converge. */
+ htab_empty (optimistic_info->nary);
+ htab_empty (optimistic_info->phis);
+ htab_empty (optimistic_info->references);
+ obstack_free (&optimistic_info->nary_obstack, NULL);
+ gcc_obstack_init (&optimistic_info->nary_obstack);
+ empty_alloc_pool (optimistic_info->phis_pool);
+ empty_alloc_pool (optimistic_info->references_pool);
+ for (i = 0; VEC_iterate (tree, scc, i, var); i++)
+ VN_INFO (var)->expr = NULL_TREE;
+ for (i = 0; VEC_iterate (tree, scc, i, var); i++)
+ changed |= visit_use (var);
+ }
+
+ statistics_histogram_event (cfun, "SCC iterations", iterations);
+
+ /* Finally, visit the SCC once using the valid table. */
+ current_info = valid_info;
+ for (i = 0; VEC_iterate (tree, scc, i, var); i++)
+ visit_use (var);
+ }
+}
+
+DEF_VEC_O(ssa_op_iter);
+DEF_VEC_ALLOC_O(ssa_op_iter,heap);
+
+/* Pop the components of the found SCC for NAME off the SCC stack
+ and process them. Returns true if all went well, false if
+ we run into resource limits. */
+
+static bool
+extract_and_process_scc_for_name (tree name)
+{
+ VEC (tree, heap) *scc = NULL;
+ tree x;
+
+ /* Found an SCC, pop the components off the SCC stack and
+ process them. */
+ do
+ {
+ x = VEC_pop (tree, sccstack);
+
+ VN_INFO (x)->on_sccstack = false;
+ VEC_safe_push (tree, heap, scc, x);
+ } while (x != name);
+
+ /* Bail out of SCCVN in case a SCC turns out to be incredibly large. */
+ if (VEC_length (tree, scc)
+ > (unsigned)PARAM_VALUE (PARAM_SCCVN_MAX_SCC_SIZE))
+ {
+ if (dump_file)
+ fprintf (dump_file, "WARNING: Giving up with SCCVN due to "
+ "SCC size %u exceeding %u\n", VEC_length (tree, scc),
+ (unsigned)PARAM_VALUE (PARAM_SCCVN_MAX_SCC_SIZE));
+ return false;
+ }
+
+ if (VEC_length (tree, scc) > 1)
+ sort_scc (scc);
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ print_scc (dump_file, scc);
+
+ process_scc (scc);
+
+ VEC_free (tree, heap, scc);
+
+ return true;
+}
+
+/* Depth first search on NAME to discover and process SCC's in the SSA
+ graph.
+ Execution of this algorithm relies on the fact that the SCC's are
+ popped off the stack in topological order.
+ Returns true if successful, false if we stopped processing SCC's due
+ to resource constraints. */
+
+static bool
+DFS (tree name)
+{
+ VEC(ssa_op_iter, heap) *itervec = NULL;
+ VEC(tree, heap) *namevec = NULL;
+ use_operand_p usep = NULL;
+ gimple defstmt;
+ tree use;
+ ssa_op_iter iter;
+
+start_over:
+ /* SCC info */
+ VN_INFO (name)->dfsnum = next_dfs_num++;
+ VN_INFO (name)->visited = true;
+ VN_INFO (name)->low = VN_INFO (name)->dfsnum;
+
+ VEC_safe_push (tree, heap, sccstack, name);
+ VN_INFO (name)->on_sccstack = true;
+ defstmt = SSA_NAME_DEF_STMT (name);
+
+ /* Recursively DFS on our operands, looking for SCC's. */
+ if (!gimple_nop_p (defstmt))
+ {
+ /* Push a new iterator. */
+ if (gimple_code (defstmt) == GIMPLE_PHI)
+ usep = op_iter_init_phiuse (&iter, defstmt, SSA_OP_ALL_USES);
+ else
+ usep = op_iter_init_use (&iter, defstmt, SSA_OP_ALL_USES);
+ }
+ else
+ clear_and_done_ssa_iter (&iter);
+
+ while (1)
+ {
+ /* If we are done processing uses of a name, go up the stack
+ of iterators and process SCCs as we found them. */
+ if (op_iter_done (&iter))
+ {
+ /* See if we found an SCC. */
+ if (VN_INFO (name)->low == VN_INFO (name)->dfsnum)
+ if (!extract_and_process_scc_for_name (name))
+ {
+ VEC_free (tree, heap, namevec);
+ VEC_free (ssa_op_iter, heap, itervec);
+ return false;
+ }
+
+ /* Check if we are done. */
+ if (VEC_empty (tree, namevec))
+ {
+ VEC_free (tree, heap, namevec);
+ VEC_free (ssa_op_iter, heap, itervec);
+ return true;
+ }
+
+ /* Restore the last use walker and continue walking there. */
+ use = name;
+ name = VEC_pop (tree, namevec);
+ memcpy (&iter, VEC_last (ssa_op_iter, itervec),
+ sizeof (ssa_op_iter));
+ VEC_pop (ssa_op_iter, itervec);
+ goto continue_walking;
+ }
+
+ use = USE_FROM_PTR (usep);
+
+ /* Since we handle phi nodes, we will sometimes get
+ invariants in the use expression. */
+ if (TREE_CODE (use) == SSA_NAME)
+ {
+ if (! (VN_INFO (use)->visited))
+ {
+ /* Recurse by pushing the current use walking state on
+ the stack and starting over. */
+ VEC_safe_push(ssa_op_iter, heap, itervec, &iter);
+ VEC_safe_push(tree, heap, namevec, name);
+ name = use;
+ goto start_over;
+
+continue_walking:
+ VN_INFO (name)->low = MIN (VN_INFO (name)->low,
+ VN_INFO (use)->low);
+ }
+ if (VN_INFO (use)->dfsnum < VN_INFO (name)->dfsnum
+ && VN_INFO (use)->on_sccstack)
+ {
+ VN_INFO (name)->low = MIN (VN_INFO (use)->dfsnum,
+ VN_INFO (name)->low);
+ }
+ }
+
+ usep = op_iter_next_use (&iter);
+ }
+}
+
+/* Allocate a value number table. */
+
+static void
+allocate_vn_table (vn_tables_t table)
+{
+ table->phis = htab_create (23, vn_phi_hash, vn_phi_eq, free_phi);
+ table->nary = htab_create (23, vn_nary_op_hash, vn_nary_op_eq, NULL);
+ table->references = htab_create (23, vn_reference_hash, vn_reference_eq,
+ free_reference);
+
+ gcc_obstack_init (&table->nary_obstack);
+ table->phis_pool = create_alloc_pool ("VN phis",
+ sizeof (struct vn_phi_s),
+ 30);
+ table->references_pool = create_alloc_pool ("VN references",
+ sizeof (struct vn_reference_s),
+ 30);
+}
+
+/* Free a value number table. */
+
+static void
+free_vn_table (vn_tables_t table)
+{
+ htab_delete (table->phis);
+ htab_delete (table->nary);
+ htab_delete (table->references);
+ obstack_free (&table->nary_obstack, NULL);
+ free_alloc_pool (table->phis_pool);
+ free_alloc_pool (table->references_pool);
+}
+
+static void
+init_scc_vn (void)
+{
+ size_t i;
+ int j;
+ int *rpo_numbers_temp;
+
+ calculate_dominance_info (CDI_DOMINATORS);
+ sccstack = NULL;
+ constant_to_value_id = htab_create (23, vn_constant_hash, vn_constant_eq,
+ free);
+
+ constant_value_ids = BITMAP_ALLOC (NULL);
+
+ next_dfs_num = 1;
+ next_value_id = 1;
+
+ vn_ssa_aux_table = VEC_alloc (vn_ssa_aux_t, heap, num_ssa_names + 1);
+ /* VEC_alloc doesn't actually grow it to the right size, it just
+ preallocates the space to do so. */
+ VEC_safe_grow_cleared (vn_ssa_aux_t, heap, vn_ssa_aux_table, num_ssa_names + 1);
+ gcc_obstack_init (&vn_ssa_aux_obstack);
+
+ shared_lookup_phiargs = NULL;
+ shared_lookup_vops = NULL;
+ shared_lookup_references = NULL;
+ rpo_numbers = XCNEWVEC (int, last_basic_block + NUM_FIXED_BLOCKS);
+ rpo_numbers_temp = XCNEWVEC (int, last_basic_block + NUM_FIXED_BLOCKS);
+ pre_and_rev_post_order_compute (NULL, rpo_numbers_temp, false);
+
+ /* RPO numbers is an array of rpo ordering, rpo[i] = bb means that
+ the i'th block in RPO order is bb. We want to map bb's to RPO
+ numbers, so we need to rearrange this array. */
+ for (j = 0; j < n_basic_blocks - NUM_FIXED_BLOCKS; j++)
+ rpo_numbers[rpo_numbers_temp[j]] = j;
+
+ XDELETE (rpo_numbers_temp);
+
+ VN_TOP = create_tmp_var_raw (void_type_node, "vn_top");
+
+ /* Create the VN_INFO structures, and initialize value numbers to
+ TOP. */
+ for (i = 0; i < num_ssa_names; i++)
+ {
+ tree name = ssa_name (i);
+ if (name)
+ {
+ VN_INFO_GET (name)->valnum = VN_TOP;
+ VN_INFO (name)->expr = NULL_TREE;
+ VN_INFO (name)->value_id = 0;
+ }
+ }
+
+ renumber_gimple_stmt_uids ();
+
+ /* Create the valid and optimistic value numbering tables. */
+ valid_info = XCNEW (struct vn_tables_s);
+ allocate_vn_table (valid_info);
+ optimistic_info = XCNEW (struct vn_tables_s);
+ allocate_vn_table (optimistic_info);
+}
+
+void
+free_scc_vn (void)
+{
+ size_t i;
+
+ htab_delete (constant_to_value_id);
+ BITMAP_FREE (constant_value_ids);
+ VEC_free (tree, heap, shared_lookup_phiargs);
+ VEC_free (tree, gc, shared_lookup_vops);
+ VEC_free (vn_reference_op_s, heap, shared_lookup_references);
+ XDELETEVEC (rpo_numbers);
+
+ for (i = 0; i < num_ssa_names; i++)
+ {
+ tree name = ssa_name (i);
+ if (name
+ && VN_INFO (name)->needs_insertion)
+ release_ssa_name (name);
+ }
+ obstack_free (&vn_ssa_aux_obstack, NULL);
+ VEC_free (vn_ssa_aux_t, heap, vn_ssa_aux_table);
+
+ VEC_free (tree, heap, sccstack);
+ free_vn_table (valid_info);
+ XDELETE (valid_info);
+ free_vn_table (optimistic_info);
+ XDELETE (optimistic_info);
+}
+
+/* Set the value ids in the valid hash tables. */
+
+static void
+set_hashtable_value_ids (void)
+{
+ htab_iterator hi;
+ vn_nary_op_t vno;
+ vn_reference_t vr;
+ vn_phi_t vp;
+
+ /* Now set the value ids of the things we had put in the hash
+ table. */
+
+ FOR_EACH_HTAB_ELEMENT (valid_info->nary,
+ vno, vn_nary_op_t, hi)
+ {
+ if (vno->result)
+ {
+ if (TREE_CODE (vno->result) == SSA_NAME)
+ vno->value_id = VN_INFO (vno->result)->value_id;
+ else if (is_gimple_min_invariant (vno->result))
+ vno->value_id = get_or_alloc_constant_value_id (vno->result);
+ }
+ }
+
+ FOR_EACH_HTAB_ELEMENT (valid_info->phis,
+ vp, vn_phi_t, hi)
+ {
+ if (vp->result)
+ {
+ if (TREE_CODE (vp->result) == SSA_NAME)
+ vp->value_id = VN_INFO (vp->result)->value_id;
+ else if (is_gimple_min_invariant (vp->result))
+ vp->value_id = get_or_alloc_constant_value_id (vp->result);
+ }
+ }
+
+ FOR_EACH_HTAB_ELEMENT (valid_info->references,
+ vr, vn_reference_t, hi)
+ {
+ if (vr->result)
+ {
+ if (TREE_CODE (vr->result) == SSA_NAME)
+ vr->value_id = VN_INFO (vr->result)->value_id;
+ else if (is_gimple_min_invariant (vr->result))
+ vr->value_id = get_or_alloc_constant_value_id (vr->result);
+ }
+ }
+}
+
+/* Do SCCVN. Returns true if it finished, false if we bailed out
+ due to resource constraints. */
+
+bool
+run_scc_vn (bool may_insert_arg)
+{
+ size_t i;
+ tree param;
+ bool changed = true;
+
+ may_insert = may_insert_arg;
+
+ init_scc_vn ();
+ current_info = valid_info;
+
+ 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);
+ SSA_VAL (def) = def;
+ }
+ }
+
+ for (i = 1; i < num_ssa_names; ++i)
+ {
+ tree name = ssa_name (i);
+ if (name
+ && VN_INFO (name)->visited == false
+ && !has_zero_uses (name))
+ if (!DFS (name))
+ {
+ free_scc_vn ();
+ may_insert = false;
+ return false;
+ }
+ }
+
+ /* Initialize the value ids. */
+
+ for (i = 1; i < num_ssa_names; ++i)
+ {
+ tree name = ssa_name (i);
+ vn_ssa_aux_t info;
+ if (!name)
+ continue;
+ info = VN_INFO (name);
+ if (info->valnum == name)
+ info->value_id = get_next_value_id ();
+ else if (is_gimple_min_invariant (info->valnum))
+ info->value_id = get_or_alloc_constant_value_id (info->valnum);
+ }
+
+ /* Propagate until they stop changing. */
+ while (changed)
+ {
+ changed = false;
+ for (i = 1; i < num_ssa_names; ++i)
+ {
+ tree name = ssa_name (i);
+ vn_ssa_aux_t info;
+ if (!name)
+ continue;
+ info = VN_INFO (name);
+ if (TREE_CODE (info->valnum) == SSA_NAME
+ && info->valnum != name
+ && info->value_id != VN_INFO (info->valnum)->value_id)
+ {
+ changed = true;
+ info->value_id = VN_INFO (info->valnum)->value_id;
+ }
+ }
+ }
+
+ set_hashtable_value_ids ();
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Value numbers:\n");
+ for (i = 0; i < num_ssa_names; i++)
+ {
+ tree name = ssa_name (i);
+ if (name
+ && VN_INFO (name)->visited
+ && SSA_VAL (name) != name)
+ {
+ print_generic_expr (dump_file, name, 0);
+ fprintf (dump_file, " = ");
+ print_generic_expr (dump_file, SSA_VAL (name), 0);
+ fprintf (dump_file, "\n");
+ }
+ }
+ }
+
+ may_insert = false;
+ return true;
+}
+
+/* Return the maximum value id we have ever seen. */
+
+unsigned int
+get_max_value_id (void)
+{
+ return next_value_id;
+}
+
+/* Return the next unique value id. */
+
+unsigned int
+get_next_value_id (void)
+{
+ return next_value_id++;
+}
+
+
+/* Compare two expressions E1 and E2 and return true if they are equal. */
+
+bool
+expressions_equal_p (tree e1, tree e2)
+{
+ /* The obvious case. */
+ if (e1 == e2)
+ return true;
+
+ /* If only one of them is null, they cannot be equal. */
+ if (!e1 || !e2)
+ return false;
+
+ /* Recurse on elements of lists. */
+ if (TREE_CODE (e1) == TREE_LIST && TREE_CODE (e2) == TREE_LIST)
+ {
+ tree lop1 = e1;
+ tree lop2 = e2;
+ for (lop1 = e1, lop2 = e2;
+ lop1 || lop2;
+ lop1 = TREE_CHAIN (lop1), lop2 = TREE_CHAIN (lop2))
+ {
+ if (!lop1 || !lop2)
+ return false;
+ if (!expressions_equal_p (TREE_VALUE (lop1), TREE_VALUE (lop2)))
+ return false;
+ }
+ return true;
+ }
+
+ /* Now perform the actual comparison. */
+ if (TREE_CODE (e1) == TREE_CODE (e2)
+ && operand_equal_p (e1, e2, OEP_PURE_SAME))
+ return true;
+
+ return false;
+}
+
+/* Sort the VUSE array so that we can do equality comparisons
+ quicker on two vuse vecs. */
+
+void
+sort_vuses (VEC (tree,gc) *vuses)
+{
+ if (VEC_length (tree, vuses) > 1)
+ qsort (VEC_address (tree, vuses),
+ VEC_length (tree, vuses),
+ sizeof (tree),
+ operand_build_cmp);
+}
+
+/* Sort the VUSE array so that we can do equality comparisons
+ quicker on two vuse vecs. */
+
+void
+sort_vuses_heap (VEC (tree,heap) *vuses)
+{
+ if (VEC_length (tree, vuses) > 1)
+ qsort (VEC_address (tree, vuses),
+ VEC_length (tree, vuses),
+ sizeof (tree),
+ operand_build_cmp);
+}
+
+
+/* Return true if the nary operation NARY may trap. This is a copy
+ of stmt_could_throw_1_p adjusted to the SCCVN IL. */
+
+bool
+vn_nary_may_trap (vn_nary_op_t nary)
+{
+ tree type;
+ tree rhs2;
+ bool honor_nans = false;
+ bool honor_snans = false;
+ bool fp_operation = false;
+ bool honor_trapv = false;
+ bool handled, ret;
+ unsigned i;
+
+ if (TREE_CODE_CLASS (nary->opcode) == tcc_comparison
+ || TREE_CODE_CLASS (nary->opcode) == tcc_unary
+ || TREE_CODE_CLASS (nary->opcode) == tcc_binary)
+ {
+ type = nary->type;
+ fp_operation = FLOAT_TYPE_P (type);
+ if (fp_operation)
+ {
+ honor_nans = flag_trapping_math && !flag_finite_math_only;
+ honor_snans = flag_signaling_nans != 0;
+ }
+ else if (INTEGRAL_TYPE_P (type)
+ && TYPE_OVERFLOW_TRAPS (type))
+ honor_trapv = true;
+ }
+ rhs2 = nary->op[1];
+ ret = operation_could_trap_helper_p (nary->opcode, fp_operation,
+ honor_trapv,
+ honor_nans, honor_snans, rhs2,
+ &handled);
+ if (handled
+ && ret)
+ return true;
+
+ for (i = 0; i < nary->length; ++i)
+ if (tree_could_trap_p (nary->op[i]))
+ return true;
+
+ return false;
+}