1 /* Loop invariant motion.
2 Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2010
3 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it
8 under the terms of the GNU General Public License as published by the
9 Free Software Foundation; either version 3, or (at your option) any
12 GCC is distributed in the hope that it will be useful, but WITHOUT
13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
23 #include "coretypes.h"
27 #include "basic-block.h"
29 #include "tree-pretty-print.h"
30 #include "gimple-pretty-print.h"
31 #include "tree-flow.h"
32 #include "tree-dump.h"
37 #include "tree-pass.h"
40 #include "tree-affine.h"
41 #include "pointer-set.h"
42 #include "tree-ssa-propagate.h"
44 /* TODO: Support for predicated code motion. I.e.
55 Where COND and INV are invariants, but evaluating INV may trap or be
56 invalid from some other reason if !COND. This may be transformed to
66 /* A type for the list of statements that have to be moved in order to be able
67 to hoist an invariant computation. */
75 /* The auxiliary data kept for each statement. */
79 struct loop *max_loop; /* The outermost loop in that the statement
82 struct loop *tgt_loop; /* The loop out of that we want to move the
85 struct loop *always_executed_in;
86 /* The outermost loop for that we are sure
87 the statement is executed if the loop
90 unsigned cost; /* Cost of the computation performed by the
93 struct depend *depends; /* List of statements that must be also hoisted
94 out of the loop when this statement is
95 hoisted; i.e. those that define the operands
96 of the statement and are inside of the
100 /* Maps statements to their lim_aux_data. */
102 static struct pointer_map_t *lim_aux_data_map;
104 /* Description of a memory reference location. */
106 typedef struct mem_ref_loc
108 tree *ref; /* The reference itself. */
109 gimple stmt; /* The statement in that it occurs. */
112 DEF_VEC_P(mem_ref_loc_p);
113 DEF_VEC_ALLOC_P(mem_ref_loc_p, heap);
115 /* The list of memory reference locations in a loop. */
117 typedef struct mem_ref_locs
119 VEC (mem_ref_loc_p, heap) *locs;
122 DEF_VEC_P(mem_ref_locs_p);
123 DEF_VEC_ALLOC_P(mem_ref_locs_p, heap);
125 /* Description of a memory reference. */
127 typedef struct mem_ref
129 tree mem; /* The memory itself. */
130 unsigned id; /* ID assigned to the memory reference
131 (its index in memory_accesses.refs_list) */
132 hashval_t hash; /* Its hash value. */
133 bitmap stored; /* The set of loops in that this memory location
135 VEC (mem_ref_locs_p, heap) *accesses_in_loop;
136 /* The locations of the accesses. Vector
137 indexed by the loop number. */
139 /* The following sets are computed on demand. We keep both set and
140 its complement, so that we know whether the information was
141 already computed or not. */
142 bitmap indep_loop; /* The set of loops in that the memory
143 reference is independent, meaning:
144 If it is stored in the loop, this store
145 is independent on all other loads and
147 If it is only loaded, then it is independent
148 on all stores in the loop. */
149 bitmap dep_loop; /* The complement of INDEP_LOOP. */
151 bitmap indep_ref; /* The set of memory references on that
152 this reference is independent. */
153 bitmap dep_ref; /* The complement of INDEP_REF. */
156 DEF_VEC_P(mem_ref_p);
157 DEF_VEC_ALLOC_P(mem_ref_p, heap);
160 DEF_VEC_ALLOC_P(bitmap, heap);
163 DEF_VEC_ALLOC_P(htab_t, heap);
165 /* Description of memory accesses in loops. */
169 /* The hash table of memory references accessed in loops. */
172 /* The list of memory references. */
173 VEC (mem_ref_p, heap) *refs_list;
175 /* The set of memory references accessed in each loop. */
176 VEC (bitmap, heap) *refs_in_loop;
178 /* The set of memory references accessed in each loop, including
180 VEC (bitmap, heap) *all_refs_in_loop;
182 /* The set of memory references stored in each loop, including
184 VEC (bitmap, heap) *all_refs_stored_in_loop;
186 /* Cache for expanding memory addresses. */
187 struct pointer_map_t *ttae_cache;
190 static bool ref_indep_loop_p (struct loop *, mem_ref_p);
192 /* Minimum cost of an expensive expression. */
193 #define LIM_EXPENSIVE ((unsigned) PARAM_VALUE (PARAM_LIM_EXPENSIVE))
195 /* The outermost loop for which execution of the header guarantees that the
196 block will be executed. */
197 #define ALWAYS_EXECUTED_IN(BB) ((struct loop *) (BB)->aux)
198 #define SET_ALWAYS_EXECUTED_IN(BB, VAL) ((BB)->aux = (void *) (VAL))
200 /* Whether the reference was analyzable. */
201 #define MEM_ANALYZABLE(REF) ((REF)->mem != error_mark_node)
203 static struct lim_aux_data *
204 init_lim_data (gimple stmt)
206 void **p = pointer_map_insert (lim_aux_data_map, stmt);
208 *p = XCNEW (struct lim_aux_data);
209 return (struct lim_aux_data *) *p;
212 static struct lim_aux_data *
213 get_lim_data (gimple stmt)
215 void **p = pointer_map_contains (lim_aux_data_map, stmt);
219 return (struct lim_aux_data *) *p;
222 /* Releases the memory occupied by DATA. */
225 free_lim_aux_data (struct lim_aux_data *data)
227 struct depend *dep, *next;
229 for (dep = data->depends; dep; dep = next)
238 clear_lim_data (gimple stmt)
240 void **p = pointer_map_contains (lim_aux_data_map, stmt);
244 free_lim_aux_data ((struct lim_aux_data *) *p);
248 /* Calls CBCK for each index in memory reference ADDR_P. There are two
249 kinds situations handled; in each of these cases, the memory reference
250 and DATA are passed to the callback:
252 Access to an array: ARRAY_{RANGE_}REF (base, index). In this case we also
253 pass the pointer to the index to the callback.
255 Pointer dereference: INDIRECT_REF (addr). In this case we also pass the
256 pointer to addr to the callback.
258 If the callback returns false, the whole search stops and false is returned.
259 Otherwise the function returns true after traversing through the whole
260 reference *ADDR_P. */
263 for_each_index (tree *addr_p, bool (*cbck) (tree, tree *, void *), void *data)
267 for (; ; addr_p = nxt)
269 switch (TREE_CODE (*addr_p))
272 return cbck (*addr_p, addr_p, data);
275 nxt = &TREE_OPERAND (*addr_p, 0);
276 return cbck (*addr_p, nxt, data);
279 case VIEW_CONVERT_EXPR:
282 nxt = &TREE_OPERAND (*addr_p, 0);
286 /* If the component has varying offset, it behaves like index
288 idx = &TREE_OPERAND (*addr_p, 2);
290 && !cbck (*addr_p, idx, data))
293 nxt = &TREE_OPERAND (*addr_p, 0);
297 case ARRAY_RANGE_REF:
298 nxt = &TREE_OPERAND (*addr_p, 0);
299 if (!cbck (*addr_p, &TREE_OPERAND (*addr_p, 1), data))
316 gcc_assert (is_gimple_min_invariant (*addr_p));
320 idx = &TMR_BASE (*addr_p);
322 && !cbck (*addr_p, idx, data))
324 idx = &TMR_INDEX (*addr_p);
326 && !cbck (*addr_p, idx, data))
328 idx = &TMR_INDEX2 (*addr_p);
330 && !cbck (*addr_p, idx, data))
340 /* If it is possible to hoist the statement STMT unconditionally,
341 returns MOVE_POSSIBLE.
342 If it is possible to hoist the statement STMT, but we must avoid making
343 it executed if it would not be executed in the original program (e.g.
344 because it may trap), return MOVE_PRESERVE_EXECUTION.
345 Otherwise return MOVE_IMPOSSIBLE. */
348 movement_possibility (gimple stmt)
351 enum move_pos ret = MOVE_POSSIBLE;
353 if (flag_unswitch_loops
354 && gimple_code (stmt) == GIMPLE_COND)
356 /* If we perform unswitching, force the operands of the invariant
357 condition to be moved out of the loop. */
358 return MOVE_POSSIBLE;
361 if (gimple_code (stmt) == GIMPLE_PHI
362 && gimple_phi_num_args (stmt) <= 2
363 && is_gimple_reg (gimple_phi_result (stmt))
364 && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (gimple_phi_result (stmt)))
365 return MOVE_POSSIBLE;
367 if (gimple_get_lhs (stmt) == NULL_TREE)
368 return MOVE_IMPOSSIBLE;
370 if (gimple_vdef (stmt))
371 return MOVE_IMPOSSIBLE;
373 if (stmt_ends_bb_p (stmt)
374 || gimple_has_volatile_ops (stmt)
375 || gimple_has_side_effects (stmt)
376 || stmt_could_throw_p (stmt))
377 return MOVE_IMPOSSIBLE;
379 if (is_gimple_call (stmt))
381 /* While pure or const call is guaranteed to have no side effects, we
382 cannot move it arbitrarily. Consider code like
384 char *s = something ();
394 Here the strlen call cannot be moved out of the loop, even though
395 s is invariant. In addition to possibly creating a call with
396 invalid arguments, moving out a function call that is not executed
397 may cause performance regressions in case the call is costly and
398 not executed at all. */
399 ret = MOVE_PRESERVE_EXECUTION;
400 lhs = gimple_call_lhs (stmt);
402 else if (is_gimple_assign (stmt))
403 lhs = gimple_assign_lhs (stmt);
405 return MOVE_IMPOSSIBLE;
407 if (TREE_CODE (lhs) == SSA_NAME
408 && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs))
409 return MOVE_IMPOSSIBLE;
411 if (TREE_CODE (lhs) != SSA_NAME
412 || gimple_could_trap_p (stmt))
413 return MOVE_PRESERVE_EXECUTION;
415 /* Non local loads in a transaction cannot be hoisted out. Well,
416 unless the load happens on every path out of the loop, but we
417 don't take this into account yet. */
419 && gimple_in_transaction (stmt)
420 && gimple_assign_single_p (stmt))
422 tree rhs = gimple_assign_rhs1 (stmt);
423 if (DECL_P (rhs) && is_global_var (rhs))
427 fprintf (dump_file, "Cannot hoist conditional load of ");
428 print_generic_expr (dump_file, rhs, TDF_SLIM);
429 fprintf (dump_file, " because it is in a transaction.\n");
431 return MOVE_IMPOSSIBLE;
438 /* Suppose that operand DEF is used inside the LOOP. Returns the outermost
439 loop to that we could move the expression using DEF if it did not have
440 other operands, i.e. the outermost loop enclosing LOOP in that the value
441 of DEF is invariant. */
444 outermost_invariant_loop (tree def, struct loop *loop)
448 struct loop *max_loop;
449 struct lim_aux_data *lim_data;
452 return superloop_at_depth (loop, 1);
454 if (TREE_CODE (def) != SSA_NAME)
456 gcc_assert (is_gimple_min_invariant (def));
457 return superloop_at_depth (loop, 1);
460 def_stmt = SSA_NAME_DEF_STMT (def);
461 def_bb = gimple_bb (def_stmt);
463 return superloop_at_depth (loop, 1);
465 max_loop = find_common_loop (loop, def_bb->loop_father);
467 lim_data = get_lim_data (def_stmt);
468 if (lim_data != NULL && lim_data->max_loop != NULL)
469 max_loop = find_common_loop (max_loop,
470 loop_outer (lim_data->max_loop));
471 if (max_loop == loop)
473 max_loop = superloop_at_depth (loop, loop_depth (max_loop) + 1);
478 /* DATA is a structure containing information associated with a statement
479 inside LOOP. DEF is one of the operands of this statement.
481 Find the outermost loop enclosing LOOP in that value of DEF is invariant
482 and record this in DATA->max_loop field. If DEF itself is defined inside
483 this loop as well (i.e. we need to hoist it out of the loop if we want
484 to hoist the statement represented by DATA), record the statement in that
485 DEF is defined to the DATA->depends list. Additionally if ADD_COST is true,
486 add the cost of the computation of DEF to the DATA->cost.
488 If DEF is not invariant in LOOP, return false. Otherwise return TRUE. */
491 add_dependency (tree def, struct lim_aux_data *data, struct loop *loop,
494 gimple def_stmt = SSA_NAME_DEF_STMT (def);
495 basic_block def_bb = gimple_bb (def_stmt);
496 struct loop *max_loop;
498 struct lim_aux_data *def_data;
503 max_loop = outermost_invariant_loop (def, loop);
507 if (flow_loop_nested_p (data->max_loop, max_loop))
508 data->max_loop = max_loop;
510 def_data = get_lim_data (def_stmt);
515 /* Only add the cost if the statement defining DEF is inside LOOP,
516 i.e. if it is likely that by moving the invariants dependent
517 on it, we will be able to avoid creating a new register for
518 it (since it will be only used in these dependent invariants). */
519 && def_bb->loop_father == loop)
520 data->cost += def_data->cost;
522 dep = XNEW (struct depend);
523 dep->stmt = def_stmt;
524 dep->next = data->depends;
530 /* Returns an estimate for a cost of statement STMT. The values here
531 are just ad-hoc constants, similar to costs for inlining. */
534 stmt_cost (gimple stmt)
536 /* Always try to create possibilities for unswitching. */
537 if (gimple_code (stmt) == GIMPLE_COND
538 || gimple_code (stmt) == GIMPLE_PHI)
539 return LIM_EXPENSIVE;
541 /* We should be hoisting calls if possible. */
542 if (is_gimple_call (stmt))
546 /* Unless the call is a builtin_constant_p; this always folds to a
547 constant, so moving it is useless. */
548 fndecl = gimple_call_fndecl (stmt);
550 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
551 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
554 return LIM_EXPENSIVE;
557 /* Hoisting memory references out should almost surely be a win. */
558 if (gimple_references_memory_p (stmt))
559 return LIM_EXPENSIVE;
561 if (gimple_code (stmt) != GIMPLE_ASSIGN)
564 switch (gimple_assign_rhs_code (stmt))
567 case WIDEN_MULT_EXPR:
568 case WIDEN_MULT_PLUS_EXPR:
569 case WIDEN_MULT_MINUS_EXPR:
582 /* Division and multiplication are usually expensive. */
583 return LIM_EXPENSIVE;
587 case WIDEN_LSHIFT_EXPR:
590 /* Shifts and rotates are usually expensive. */
591 return LIM_EXPENSIVE;
594 /* Make vector construction cost proportional to the number
596 return CONSTRUCTOR_NELTS (gimple_assign_rhs1 (stmt));
600 /* Whether or not something is wrapped inside a PAREN_EXPR
601 should not change move cost. Nor should an intermediate
602 unpropagated SSA name copy. */
610 /* Finds the outermost loop between OUTER and LOOP in that the memory reference
611 REF is independent. If REF is not independent in LOOP, NULL is returned
615 outermost_indep_loop (struct loop *outer, struct loop *loop, mem_ref_p ref)
619 if (bitmap_bit_p (ref->stored, loop->num))
624 aloop = superloop_at_depth (loop, loop_depth (aloop) + 1))
625 if (!bitmap_bit_p (ref->stored, aloop->num)
626 && ref_indep_loop_p (aloop, ref))
629 if (ref_indep_loop_p (loop, ref))
635 /* If there is a simple load or store to a memory reference in STMT, returns
636 the location of the memory reference, and sets IS_STORE according to whether
637 it is a store or load. Otherwise, returns NULL. */
640 simple_mem_ref_in_stmt (gimple stmt, bool *is_store)
645 /* Recognize MEM = (SSA_NAME | invariant) and SSA_NAME = MEM patterns. */
646 if (gimple_code (stmt) != GIMPLE_ASSIGN)
649 code = gimple_assign_rhs_code (stmt);
651 lhs = gimple_assign_lhs_ptr (stmt);
653 if (TREE_CODE (*lhs) == SSA_NAME)
655 if (get_gimple_rhs_class (code) != GIMPLE_SINGLE_RHS
656 || !is_gimple_addressable (gimple_assign_rhs1 (stmt)))
660 return gimple_assign_rhs1_ptr (stmt);
662 else if (code == SSA_NAME
663 || (get_gimple_rhs_class (code) == GIMPLE_SINGLE_RHS
664 && is_gimple_min_invariant (gimple_assign_rhs1 (stmt))))
673 /* Returns the memory reference contained in STMT. */
676 mem_ref_in_stmt (gimple stmt)
679 tree *mem = simple_mem_ref_in_stmt (stmt, &store);
687 hash = iterative_hash_expr (*mem, 0);
688 ref = (mem_ref_p) htab_find_with_hash (memory_accesses.refs, *mem, hash);
690 gcc_assert (ref != NULL);
694 /* From a controlling predicate in DOM determine the arguments from
695 the PHI node PHI that are chosen if the predicate evaluates to
696 true and false and store them to *TRUE_ARG_P and *FALSE_ARG_P if
697 they are non-NULL. Returns true if the arguments can be determined,
698 else return false. */
701 extract_true_false_args_from_phi (basic_block dom, gimple phi,
702 tree *true_arg_p, tree *false_arg_p)
704 basic_block bb = gimple_bb (phi);
705 edge true_edge, false_edge, tem;
706 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
708 /* We have to verify that one edge into the PHI node is dominated
709 by the true edge of the predicate block and the other edge
710 dominated by the false edge. This ensures that the PHI argument
711 we are going to take is completely determined by the path we
712 take from the predicate block.
713 We can only use BB dominance checks below if the destination of
714 the true/false edges are dominated by their edge, thus only
715 have a single predecessor. */
716 extract_true_false_edges_from_block (dom, &true_edge, &false_edge);
717 tem = EDGE_PRED (bb, 0);
719 || (single_pred_p (true_edge->dest)
720 && (tem->src == true_edge->dest
721 || dominated_by_p (CDI_DOMINATORS,
722 tem->src, true_edge->dest))))
723 arg0 = PHI_ARG_DEF (phi, tem->dest_idx);
724 else if (tem == false_edge
725 || (single_pred_p (false_edge->dest)
726 && (tem->src == false_edge->dest
727 || dominated_by_p (CDI_DOMINATORS,
728 tem->src, false_edge->dest))))
729 arg1 = PHI_ARG_DEF (phi, tem->dest_idx);
732 tem = EDGE_PRED (bb, 1);
734 || (single_pred_p (true_edge->dest)
735 && (tem->src == true_edge->dest
736 || dominated_by_p (CDI_DOMINATORS,
737 tem->src, true_edge->dest))))
738 arg0 = PHI_ARG_DEF (phi, tem->dest_idx);
739 else if (tem == false_edge
740 || (single_pred_p (false_edge->dest)
741 && (tem->src == false_edge->dest
742 || dominated_by_p (CDI_DOMINATORS,
743 tem->src, false_edge->dest))))
744 arg1 = PHI_ARG_DEF (phi, tem->dest_idx);
758 /* Determine the outermost loop to that it is possible to hoist a statement
759 STMT and store it to LIM_DATA (STMT)->max_loop. To do this we determine
760 the outermost loop in that the value computed by STMT is invariant.
761 If MUST_PRESERVE_EXEC is true, additionally choose such a loop that
762 we preserve the fact whether STMT is executed. It also fills other related
763 information to LIM_DATA (STMT).
765 The function returns false if STMT cannot be hoisted outside of the loop it
766 is defined in, and true otherwise. */
769 determine_max_movement (gimple stmt, bool must_preserve_exec)
771 basic_block bb = gimple_bb (stmt);
772 struct loop *loop = bb->loop_father;
774 struct lim_aux_data *lim_data = get_lim_data (stmt);
778 if (must_preserve_exec)
779 level = ALWAYS_EXECUTED_IN (bb);
781 level = superloop_at_depth (loop, 1);
782 lim_data->max_loop = level;
784 if (gimple_code (stmt) == GIMPLE_PHI)
787 unsigned min_cost = UINT_MAX;
788 unsigned total_cost = 0;
789 struct lim_aux_data *def_data;
791 /* We will end up promoting dependencies to be unconditionally
792 evaluated. For this reason the PHI cost (and thus the
793 cost we remove from the loop by doing the invariant motion)
794 is that of the cheapest PHI argument dependency chain. */
795 FOR_EACH_PHI_ARG (use_p, stmt, iter, SSA_OP_USE)
797 val = USE_FROM_PTR (use_p);
798 if (TREE_CODE (val) != SSA_NAME)
800 if (!add_dependency (val, lim_data, loop, false))
802 def_data = get_lim_data (SSA_NAME_DEF_STMT (val));
805 min_cost = MIN (min_cost, def_data->cost);
806 total_cost += def_data->cost;
810 lim_data->cost += min_cost;
812 if (gimple_phi_num_args (stmt) > 1)
814 basic_block dom = get_immediate_dominator (CDI_DOMINATORS, bb);
816 if (gsi_end_p (gsi_last_bb (dom)))
818 cond = gsi_stmt (gsi_last_bb (dom));
819 if (gimple_code (cond) != GIMPLE_COND)
821 /* Verify that this is an extended form of a diamond and
822 the PHI arguments are completely controlled by the
824 if (!extract_true_false_args_from_phi (dom, stmt, NULL, NULL))
827 /* Fold in dependencies and cost of the condition. */
828 FOR_EACH_SSA_TREE_OPERAND (val, cond, iter, SSA_OP_USE)
830 if (!add_dependency (val, lim_data, loop, false))
832 def_data = get_lim_data (SSA_NAME_DEF_STMT (val));
834 total_cost += def_data->cost;
837 /* We want to avoid unconditionally executing very expensive
838 operations. As costs for our dependencies cannot be
839 negative just claim we are not invariand for this case.
840 We also are not sure whether the control-flow inside the
842 if (total_cost - min_cost >= 2 * LIM_EXPENSIVE
844 && total_cost / min_cost <= 2))
847 /* Assume that the control-flow in the loop will vanish.
848 ??? We should verify this and not artificially increase
849 the cost if that is not the case. */
850 lim_data->cost += stmt_cost (stmt);
856 FOR_EACH_SSA_TREE_OPERAND (val, stmt, iter, SSA_OP_USE)
857 if (!add_dependency (val, lim_data, loop, true))
860 if (gimple_vuse (stmt))
862 mem_ref_p ref = mem_ref_in_stmt (stmt);
867 = outermost_indep_loop (lim_data->max_loop, loop, ref);
868 if (!lim_data->max_loop)
873 if ((val = gimple_vuse (stmt)) != NULL_TREE)
875 if (!add_dependency (val, lim_data, loop, false))
881 lim_data->cost += stmt_cost (stmt);
886 /* Suppose that some statement in ORIG_LOOP is hoisted to the loop LEVEL,
887 and that one of the operands of this statement is computed by STMT.
888 Ensure that STMT (together with all the statements that define its
889 operands) is hoisted at least out of the loop LEVEL. */
892 set_level (gimple stmt, struct loop *orig_loop, struct loop *level)
894 struct loop *stmt_loop = gimple_bb (stmt)->loop_father;
896 struct lim_aux_data *lim_data;
898 stmt_loop = find_common_loop (orig_loop, stmt_loop);
899 lim_data = get_lim_data (stmt);
900 if (lim_data != NULL && lim_data->tgt_loop != NULL)
901 stmt_loop = find_common_loop (stmt_loop,
902 loop_outer (lim_data->tgt_loop));
903 if (flow_loop_nested_p (stmt_loop, level))
906 gcc_assert (level == lim_data->max_loop
907 || flow_loop_nested_p (lim_data->max_loop, level));
909 lim_data->tgt_loop = level;
910 for (dep = lim_data->depends; dep; dep = dep->next)
911 set_level (dep->stmt, orig_loop, level);
914 /* Determines an outermost loop from that we want to hoist the statement STMT.
915 For now we chose the outermost possible loop. TODO -- use profiling
916 information to set it more sanely. */
919 set_profitable_level (gimple stmt)
921 set_level (stmt, gimple_bb (stmt)->loop_father, get_lim_data (stmt)->max_loop);
924 /* Returns true if STMT is a call that has side effects. */
927 nonpure_call_p (gimple stmt)
929 if (gimple_code (stmt) != GIMPLE_CALL)
932 return gimple_has_side_effects (stmt);
935 /* Rewrite a/b to a*(1/b). Return the invariant stmt to process. */
938 rewrite_reciprocal (gimple_stmt_iterator *bsi)
940 gimple stmt, stmt1, stmt2;
941 tree var, name, lhs, type;
943 gimple_stmt_iterator gsi;
945 stmt = gsi_stmt (*bsi);
946 lhs = gimple_assign_lhs (stmt);
947 type = TREE_TYPE (lhs);
949 var = create_tmp_var (type, "reciptmp");
950 add_referenced_var (var);
951 DECL_GIMPLE_REG_P (var) = 1;
953 real_one = build_one_cst (type);
955 stmt1 = gimple_build_assign_with_ops (RDIV_EXPR,
956 var, real_one, gimple_assign_rhs2 (stmt));
957 name = make_ssa_name (var, stmt1);
958 gimple_assign_set_lhs (stmt1, name);
960 stmt2 = gimple_build_assign_with_ops (MULT_EXPR, lhs, name,
961 gimple_assign_rhs1 (stmt));
963 /* Replace division stmt with reciprocal and multiply stmts.
964 The multiply stmt is not invariant, so update iterator
965 and avoid rescanning. */
967 gsi_insert_before (bsi, stmt1, GSI_NEW_STMT);
968 gsi_replace (&gsi, stmt2, true);
970 /* Continue processing with invariant reciprocal statement. */
974 /* Check if the pattern at *BSI is a bittest of the form
975 (A >> B) & 1 != 0 and in this case rewrite it to A & (1 << B) != 0. */
978 rewrite_bittest (gimple_stmt_iterator *bsi)
980 gimple stmt, use_stmt, stmt1, stmt2;
981 tree lhs, var, name, t, a, b;
984 stmt = gsi_stmt (*bsi);
985 lhs = gimple_assign_lhs (stmt);
987 /* Verify that the single use of lhs is a comparison against zero. */
988 if (TREE_CODE (lhs) != SSA_NAME
989 || !single_imm_use (lhs, &use, &use_stmt)
990 || gimple_code (use_stmt) != GIMPLE_COND)
992 if (gimple_cond_lhs (use_stmt) != lhs
993 || (gimple_cond_code (use_stmt) != NE_EXPR
994 && gimple_cond_code (use_stmt) != EQ_EXPR)
995 || !integer_zerop (gimple_cond_rhs (use_stmt)))
998 /* Get at the operands of the shift. The rhs is TMP1 & 1. */
999 stmt1 = SSA_NAME_DEF_STMT (gimple_assign_rhs1 (stmt));
1000 if (gimple_code (stmt1) != GIMPLE_ASSIGN)
1003 /* There is a conversion in between possibly inserted by fold. */
1004 if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (stmt1)))
1006 t = gimple_assign_rhs1 (stmt1);
1007 if (TREE_CODE (t) != SSA_NAME
1008 || !has_single_use (t))
1010 stmt1 = SSA_NAME_DEF_STMT (t);
1011 if (gimple_code (stmt1) != GIMPLE_ASSIGN)
1015 /* Verify that B is loop invariant but A is not. Verify that with
1016 all the stmt walking we are still in the same loop. */
1017 if (gimple_assign_rhs_code (stmt1) != RSHIFT_EXPR
1018 || loop_containing_stmt (stmt1) != loop_containing_stmt (stmt))
1021 a = gimple_assign_rhs1 (stmt1);
1022 b = gimple_assign_rhs2 (stmt1);
1024 if (outermost_invariant_loop (b, loop_containing_stmt (stmt1)) != NULL
1025 && outermost_invariant_loop (a, loop_containing_stmt (stmt1)) == NULL)
1027 gimple_stmt_iterator rsi;
1030 var = create_tmp_var (TREE_TYPE (a), "shifttmp");
1031 add_referenced_var (var);
1032 t = fold_build2 (LSHIFT_EXPR, TREE_TYPE (a),
1033 build_int_cst (TREE_TYPE (a), 1), b);
1034 stmt1 = gimple_build_assign (var, t);
1035 name = make_ssa_name (var, stmt1);
1036 gimple_assign_set_lhs (stmt1, name);
1039 t = fold_build2 (BIT_AND_EXPR, TREE_TYPE (a), a, name);
1040 stmt2 = gimple_build_assign (var, t);
1041 name = make_ssa_name (var, stmt2);
1042 gimple_assign_set_lhs (stmt2, name);
1044 /* Replace the SSA_NAME we compare against zero. Adjust
1045 the type of zero accordingly. */
1046 SET_USE (use, name);
1047 gimple_cond_set_rhs (use_stmt, build_int_cst_type (TREE_TYPE (name), 0));
1049 /* Don't use gsi_replace here, none of the new assignments sets
1050 the variable originally set in stmt. Move bsi to stmt1, and
1051 then remove the original stmt, so that we get a chance to
1052 retain debug info for it. */
1054 gsi_insert_before (bsi, stmt1, GSI_NEW_STMT);
1055 gsi_insert_before (&rsi, stmt2, GSI_SAME_STMT);
1056 gsi_remove (&rsi, true);
1065 /* Determine the outermost loops in that statements in basic block BB are
1066 invariant, and record them to the LIM_DATA associated with the statements.
1067 Callback for walk_dominator_tree. */
1070 determine_invariantness_stmt (struct dom_walk_data *dw_data ATTRIBUTE_UNUSED,
1074 gimple_stmt_iterator bsi;
1076 bool maybe_never = ALWAYS_EXECUTED_IN (bb) == NULL;
1077 struct loop *outermost = ALWAYS_EXECUTED_IN (bb);
1078 struct lim_aux_data *lim_data;
1080 if (!loop_outer (bb->loop_father))
1083 if (dump_file && (dump_flags & TDF_DETAILS))
1084 fprintf (dump_file, "Basic block %d (loop %d -- depth %d):\n\n",
1085 bb->index, bb->loop_father->num, loop_depth (bb->loop_father));
1087 /* Look at PHI nodes, but only if there is at most two.
1088 ??? We could relax this further by post-processing the inserted
1089 code and transforming adjacent cond-exprs with the same predicate
1090 to control flow again. */
1091 bsi = gsi_start_phis (bb);
1092 if (!gsi_end_p (bsi)
1093 && ((gsi_next (&bsi), gsi_end_p (bsi))
1094 || (gsi_next (&bsi), gsi_end_p (bsi))))
1095 for (bsi = gsi_start_phis (bb); !gsi_end_p (bsi); gsi_next (&bsi))
1097 stmt = gsi_stmt (bsi);
1099 pos = movement_possibility (stmt);
1100 if (pos == MOVE_IMPOSSIBLE)
1103 lim_data = init_lim_data (stmt);
1104 lim_data->always_executed_in = outermost;
1106 if (!determine_max_movement (stmt, false))
1108 lim_data->max_loop = NULL;
1112 if (dump_file && (dump_flags & TDF_DETAILS))
1114 print_gimple_stmt (dump_file, stmt, 2, 0);
1115 fprintf (dump_file, " invariant up to level %d, cost %d.\n\n",
1116 loop_depth (lim_data->max_loop),
1120 if (lim_data->cost >= LIM_EXPENSIVE)
1121 set_profitable_level (stmt);
1124 for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi))
1126 stmt = gsi_stmt (bsi);
1128 pos = movement_possibility (stmt);
1129 if (pos == MOVE_IMPOSSIBLE)
1131 if (nonpure_call_p (stmt))
1136 /* Make sure to note always_executed_in for stores to make
1137 store-motion work. */
1138 else if (stmt_makes_single_store (stmt))
1140 struct lim_aux_data *lim_data = init_lim_data (stmt);
1141 lim_data->always_executed_in = outermost;
1146 if (is_gimple_assign (stmt)
1147 && (get_gimple_rhs_class (gimple_assign_rhs_code (stmt))
1148 == GIMPLE_BINARY_RHS))
1150 tree op0 = gimple_assign_rhs1 (stmt);
1151 tree op1 = gimple_assign_rhs2 (stmt);
1152 struct loop *ol1 = outermost_invariant_loop (op1,
1153 loop_containing_stmt (stmt));
1155 /* If divisor is invariant, convert a/b to a*(1/b), allowing reciprocal
1156 to be hoisted out of loop, saving expensive divide. */
1157 if (pos == MOVE_POSSIBLE
1158 && gimple_assign_rhs_code (stmt) == RDIV_EXPR
1159 && flag_unsafe_math_optimizations
1160 && !flag_trapping_math
1162 && outermost_invariant_loop (op0, ol1) == NULL)
1163 stmt = rewrite_reciprocal (&bsi);
1165 /* If the shift count is invariant, convert (A >> B) & 1 to
1166 A & (1 << B) allowing the bit mask to be hoisted out of the loop
1167 saving an expensive shift. */
1168 if (pos == MOVE_POSSIBLE
1169 && gimple_assign_rhs_code (stmt) == BIT_AND_EXPR
1170 && integer_onep (op1)
1171 && TREE_CODE (op0) == SSA_NAME
1172 && has_single_use (op0))
1173 stmt = rewrite_bittest (&bsi);
1176 lim_data = init_lim_data (stmt);
1177 lim_data->always_executed_in = outermost;
1179 if (maybe_never && pos == MOVE_PRESERVE_EXECUTION)
1182 if (!determine_max_movement (stmt, pos == MOVE_PRESERVE_EXECUTION))
1184 lim_data->max_loop = NULL;
1188 if (dump_file && (dump_flags & TDF_DETAILS))
1190 print_gimple_stmt (dump_file, stmt, 2, 0);
1191 fprintf (dump_file, " invariant up to level %d, cost %d.\n\n",
1192 loop_depth (lim_data->max_loop),
1196 if (lim_data->cost >= LIM_EXPENSIVE)
1197 set_profitable_level (stmt);
1201 /* For each statement determines the outermost loop in that it is invariant,
1202 statements on whose motion it depends and the cost of the computation.
1203 This information is stored to the LIM_DATA structure associated with
1207 determine_invariantness (void)
1209 struct dom_walk_data walk_data;
1211 memset (&walk_data, 0, sizeof (struct dom_walk_data));
1212 walk_data.dom_direction = CDI_DOMINATORS;
1213 walk_data.before_dom_children = determine_invariantness_stmt;
1215 init_walk_dominator_tree (&walk_data);
1216 walk_dominator_tree (&walk_data, ENTRY_BLOCK_PTR);
1217 fini_walk_dominator_tree (&walk_data);
1220 /* Hoist the statements in basic block BB out of the loops prescribed by
1221 data stored in LIM_DATA structures associated with each statement. Callback
1222 for walk_dominator_tree. */
1225 move_computations_stmt (struct dom_walk_data *dw_data,
1229 gimple_stmt_iterator bsi;
1232 struct lim_aux_data *lim_data;
1234 if (!loop_outer (bb->loop_father))
1237 for (bsi = gsi_start_phis (bb); !gsi_end_p (bsi); )
1240 stmt = gsi_stmt (bsi);
1242 lim_data = get_lim_data (stmt);
1243 if (lim_data == NULL)
1249 cost = lim_data->cost;
1250 level = lim_data->tgt_loop;
1251 clear_lim_data (stmt);
1259 if (dump_file && (dump_flags & TDF_DETAILS))
1261 fprintf (dump_file, "Moving PHI node\n");
1262 print_gimple_stmt (dump_file, stmt, 0, 0);
1263 fprintf (dump_file, "(cost %u) out of loop %d.\n\n",
1267 if (gimple_phi_num_args (stmt) == 1)
1269 tree arg = PHI_ARG_DEF (stmt, 0);
1270 new_stmt = gimple_build_assign_with_ops (TREE_CODE (arg),
1271 gimple_phi_result (stmt),
1273 SSA_NAME_DEF_STMT (gimple_phi_result (stmt)) = new_stmt;
1277 basic_block dom = get_immediate_dominator (CDI_DOMINATORS, bb);
1278 gimple cond = gsi_stmt (gsi_last_bb (dom));
1279 tree arg0 = NULL_TREE, arg1 = NULL_TREE, t;
1280 /* Get the PHI arguments corresponding to the true and false
1282 extract_true_false_args_from_phi (dom, stmt, &arg0, &arg1);
1283 gcc_assert (arg0 && arg1);
1284 t = build2 (gimple_cond_code (cond), boolean_type_node,
1285 gimple_cond_lhs (cond), gimple_cond_rhs (cond));
1286 new_stmt = gimple_build_assign_with_ops3 (COND_EXPR,
1287 gimple_phi_result (stmt),
1289 SSA_NAME_DEF_STMT (gimple_phi_result (stmt)) = new_stmt;
1290 *((unsigned int *)(dw_data->global_data)) |= TODO_cleanup_cfg;
1292 gsi_insert_on_edge (loop_preheader_edge (level), new_stmt);
1293 remove_phi_node (&bsi, false);
1296 for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); )
1298 stmt = gsi_stmt (bsi);
1300 lim_data = get_lim_data (stmt);
1301 if (lim_data == NULL)
1307 cost = lim_data->cost;
1308 level = lim_data->tgt_loop;
1309 clear_lim_data (stmt);
1317 /* We do not really want to move conditionals out of the loop; we just
1318 placed it here to force its operands to be moved if necessary. */
1319 if (gimple_code (stmt) == GIMPLE_COND)
1322 if (dump_file && (dump_flags & TDF_DETAILS))
1324 fprintf (dump_file, "Moving statement\n");
1325 print_gimple_stmt (dump_file, stmt, 0, 0);
1326 fprintf (dump_file, "(cost %u) out of loop %d.\n\n",
1330 mark_virtual_ops_for_renaming (stmt);
1331 gsi_insert_on_edge (loop_preheader_edge (level), stmt);
1332 gsi_remove (&bsi, false);
1336 /* Hoist the statements out of the loops prescribed by data stored in
1337 LIM_DATA structures associated with each statement.*/
1340 move_computations (void)
1342 struct dom_walk_data walk_data;
1343 unsigned int todo = 0;
1345 memset (&walk_data, 0, sizeof (struct dom_walk_data));
1346 walk_data.global_data = &todo;
1347 walk_data.dom_direction = CDI_DOMINATORS;
1348 walk_data.before_dom_children = move_computations_stmt;
1350 init_walk_dominator_tree (&walk_data);
1351 walk_dominator_tree (&walk_data, ENTRY_BLOCK_PTR);
1352 fini_walk_dominator_tree (&walk_data);
1354 gsi_commit_edge_inserts ();
1355 if (need_ssa_update_p (cfun))
1356 rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa);
1361 /* Checks whether the statement defining variable *INDEX can be hoisted
1362 out of the loop passed in DATA. Callback for for_each_index. */
1365 may_move_till (tree ref, tree *index, void *data)
1367 struct loop *loop = (struct loop *) data, *max_loop;
1369 /* If REF is an array reference, check also that the step and the lower
1370 bound is invariant in LOOP. */
1371 if (TREE_CODE (ref) == ARRAY_REF)
1373 tree step = TREE_OPERAND (ref, 3);
1374 tree lbound = TREE_OPERAND (ref, 2);
1376 max_loop = outermost_invariant_loop (step, loop);
1380 max_loop = outermost_invariant_loop (lbound, loop);
1385 max_loop = outermost_invariant_loop (*index, loop);
1392 /* If OP is SSA NAME, force the statement that defines it to be
1393 moved out of the LOOP. ORIG_LOOP is the loop in that EXPR is used. */
1396 force_move_till_op (tree op, struct loop *orig_loop, struct loop *loop)
1401 || is_gimple_min_invariant (op))
1404 gcc_assert (TREE_CODE (op) == SSA_NAME);
1406 stmt = SSA_NAME_DEF_STMT (op);
1407 if (gimple_nop_p (stmt))
1410 set_level (stmt, orig_loop, loop);
1413 /* Forces statement defining invariants in REF (and *INDEX) to be moved out of
1414 the LOOP. The reference REF is used in the loop ORIG_LOOP. Callback for
1420 struct loop *orig_loop;
1424 force_move_till (tree ref, tree *index, void *data)
1426 struct fmt_data *fmt_data = (struct fmt_data *) data;
1428 if (TREE_CODE (ref) == ARRAY_REF)
1430 tree step = TREE_OPERAND (ref, 3);
1431 tree lbound = TREE_OPERAND (ref, 2);
1433 force_move_till_op (step, fmt_data->orig_loop, fmt_data->loop);
1434 force_move_till_op (lbound, fmt_data->orig_loop, fmt_data->loop);
1437 force_move_till_op (*index, fmt_data->orig_loop, fmt_data->loop);
1442 /* A hash function for struct mem_ref object OBJ. */
1445 memref_hash (const void *obj)
1447 const struct mem_ref *const mem = (const struct mem_ref *) obj;
1452 /* An equality function for struct mem_ref object OBJ1 with
1453 memory reference OBJ2. */
1456 memref_eq (const void *obj1, const void *obj2)
1458 const struct mem_ref *const mem1 = (const struct mem_ref *) obj1;
1460 return operand_equal_p (mem1->mem, (const_tree) obj2, 0);
1463 /* Releases list of memory reference locations ACCS. */
1466 free_mem_ref_locs (mem_ref_locs_p accs)
1474 FOR_EACH_VEC_ELT (mem_ref_loc_p, accs->locs, i, loc)
1476 VEC_free (mem_ref_loc_p, heap, accs->locs);
1480 /* A function to free the mem_ref object OBJ. */
1483 memref_free (struct mem_ref *mem)
1486 mem_ref_locs_p accs;
1488 BITMAP_FREE (mem->stored);
1489 BITMAP_FREE (mem->indep_loop);
1490 BITMAP_FREE (mem->dep_loop);
1491 BITMAP_FREE (mem->indep_ref);
1492 BITMAP_FREE (mem->dep_ref);
1494 FOR_EACH_VEC_ELT (mem_ref_locs_p, mem->accesses_in_loop, i, accs)
1495 free_mem_ref_locs (accs);
1496 VEC_free (mem_ref_locs_p, heap, mem->accesses_in_loop);
1501 /* Allocates and returns a memory reference description for MEM whose hash
1502 value is HASH and id is ID. */
1505 mem_ref_alloc (tree mem, unsigned hash, unsigned id)
1507 mem_ref_p ref = XNEW (struct mem_ref);
1511 ref->stored = BITMAP_ALLOC (NULL);
1512 ref->indep_loop = BITMAP_ALLOC (NULL);
1513 ref->dep_loop = BITMAP_ALLOC (NULL);
1514 ref->indep_ref = BITMAP_ALLOC (NULL);
1515 ref->dep_ref = BITMAP_ALLOC (NULL);
1516 ref->accesses_in_loop = NULL;
1521 /* Allocates and returns the new list of locations. */
1523 static mem_ref_locs_p
1524 mem_ref_locs_alloc (void)
1526 mem_ref_locs_p accs = XNEW (struct mem_ref_locs);
1531 /* Records memory reference location *LOC in LOOP to the memory reference
1532 description REF. The reference occurs in statement STMT. */
1535 record_mem_ref_loc (mem_ref_p ref, struct loop *loop, gimple stmt, tree *loc)
1537 mem_ref_loc_p aref = XNEW (struct mem_ref_loc);
1538 mem_ref_locs_p accs;
1539 bitmap ril = VEC_index (bitmap, memory_accesses.refs_in_loop, loop->num);
1541 if (VEC_length (mem_ref_locs_p, ref->accesses_in_loop)
1542 <= (unsigned) loop->num)
1543 VEC_safe_grow_cleared (mem_ref_locs_p, heap, ref->accesses_in_loop,
1545 accs = VEC_index (mem_ref_locs_p, ref->accesses_in_loop, loop->num);
1548 accs = mem_ref_locs_alloc ();
1549 VEC_replace (mem_ref_locs_p, ref->accesses_in_loop, loop->num, accs);
1555 VEC_safe_push (mem_ref_loc_p, heap, accs->locs, aref);
1556 bitmap_set_bit (ril, ref->id);
1559 /* Marks reference REF as stored in LOOP. */
1562 mark_ref_stored (mem_ref_p ref, struct loop *loop)
1565 loop != current_loops->tree_root
1566 && !bitmap_bit_p (ref->stored, loop->num);
1567 loop = loop_outer (loop))
1568 bitmap_set_bit (ref->stored, loop->num);
1571 /* Gathers memory references in statement STMT in LOOP, storing the
1572 information about them in the memory_accesses structure. Marks
1573 the vops accessed through unrecognized statements there as
1577 gather_mem_refs_stmt (struct loop *loop, gimple stmt)
1586 if (!gimple_vuse (stmt))
1589 mem = simple_mem_ref_in_stmt (stmt, &is_stored);
1592 id = VEC_length (mem_ref_p, memory_accesses.refs_list);
1593 ref = mem_ref_alloc (error_mark_node, 0, id);
1594 VEC_safe_push (mem_ref_p, heap, memory_accesses.refs_list, ref);
1595 if (dump_file && (dump_flags & TDF_DETAILS))
1597 fprintf (dump_file, "Unanalyzed memory reference %u: ", id);
1598 print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
1600 if (gimple_vdef (stmt))
1601 mark_ref_stored (ref, loop);
1602 record_mem_ref_loc (ref, loop, stmt, mem);
1606 hash = iterative_hash_expr (*mem, 0);
1607 slot = htab_find_slot_with_hash (memory_accesses.refs, *mem, hash, INSERT);
1611 ref = (mem_ref_p) *slot;
1616 id = VEC_length (mem_ref_p, memory_accesses.refs_list);
1617 ref = mem_ref_alloc (*mem, hash, id);
1618 VEC_safe_push (mem_ref_p, heap, memory_accesses.refs_list, ref);
1621 if (dump_file && (dump_flags & TDF_DETAILS))
1623 fprintf (dump_file, "Memory reference %u: ", id);
1624 print_generic_expr (dump_file, ref->mem, TDF_SLIM);
1625 fprintf (dump_file, "\n");
1630 mark_ref_stored (ref, loop);
1632 record_mem_ref_loc (ref, loop, stmt, mem);
1636 /* Gathers memory references in loops. */
1639 gather_mem_refs_in_loops (void)
1641 gimple_stmt_iterator bsi;
1645 bitmap lrefs, alrefs, alrefso;
1649 loop = bb->loop_father;
1650 if (loop == current_loops->tree_root)
1653 for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi))
1654 gather_mem_refs_stmt (loop, gsi_stmt (bsi));
1657 /* Propagate the information about accessed memory references up
1658 the loop hierarchy. */
1659 FOR_EACH_LOOP (li, loop, LI_FROM_INNERMOST)
1661 lrefs = VEC_index (bitmap, memory_accesses.refs_in_loop, loop->num);
1662 alrefs = VEC_index (bitmap, memory_accesses.all_refs_in_loop, loop->num);
1663 bitmap_ior_into (alrefs, lrefs);
1665 if (loop_outer (loop) == current_loops->tree_root)
1668 alrefso = VEC_index (bitmap, memory_accesses.all_refs_in_loop,
1669 loop_outer (loop)->num);
1670 bitmap_ior_into (alrefso, alrefs);
1674 /* Create a mapping from virtual operands to references that touch them
1678 create_vop_ref_mapping_loop (struct loop *loop)
1680 bitmap refs = VEC_index (bitmap, memory_accesses.refs_in_loop, loop->num);
1686 EXECUTE_IF_SET_IN_BITMAP (refs, 0, i, bi)
1688 ref = VEC_index (mem_ref_p, memory_accesses.refs_list, i);
1689 for (sloop = loop; sloop != current_loops->tree_root;
1690 sloop = loop_outer (sloop))
1691 if (bitmap_bit_p (ref->stored, loop->num))
1694 = VEC_index (bitmap, memory_accesses.all_refs_stored_in_loop,
1696 bitmap_set_bit (refs_stored, ref->id);
1701 /* For each non-clobbered virtual operand and each loop, record the memory
1702 references in this loop that touch the operand. */
1705 create_vop_ref_mapping (void)
1710 FOR_EACH_LOOP (li, loop, 0)
1712 create_vop_ref_mapping_loop (loop);
1716 /* Gathers information about memory accesses in the loops. */
1719 analyze_memory_references (void)
1724 memory_accesses.refs = htab_create (100, memref_hash, memref_eq, NULL);
1725 memory_accesses.refs_list = NULL;
1726 memory_accesses.refs_in_loop = VEC_alloc (bitmap, heap,
1727 number_of_loops ());
1728 memory_accesses.all_refs_in_loop = VEC_alloc (bitmap, heap,
1729 number_of_loops ());
1730 memory_accesses.all_refs_stored_in_loop = VEC_alloc (bitmap, heap,
1731 number_of_loops ());
1733 for (i = 0; i < number_of_loops (); i++)
1735 empty = BITMAP_ALLOC (NULL);
1736 VEC_quick_push (bitmap, memory_accesses.refs_in_loop, empty);
1737 empty = BITMAP_ALLOC (NULL);
1738 VEC_quick_push (bitmap, memory_accesses.all_refs_in_loop, empty);
1739 empty = BITMAP_ALLOC (NULL);
1740 VEC_quick_push (bitmap, memory_accesses.all_refs_stored_in_loop, empty);
1743 memory_accesses.ttae_cache = NULL;
1745 gather_mem_refs_in_loops ();
1746 create_vop_ref_mapping ();
1749 /* Returns true if MEM1 and MEM2 may alias. TTAE_CACHE is used as a cache in
1750 tree_to_aff_combination_expand. */
1753 mem_refs_may_alias_p (tree mem1, tree mem2, struct pointer_map_t **ttae_cache)
1755 /* Perform BASE + OFFSET analysis -- if MEM1 and MEM2 are based on the same
1756 object and their offset differ in such a way that the locations cannot
1757 overlap, then they cannot alias. */
1758 double_int size1, size2;
1759 aff_tree off1, off2;
1761 /* Perform basic offset and type-based disambiguation. */
1762 if (!refs_may_alias_p (mem1, mem2))
1765 /* The expansion of addresses may be a bit expensive, thus we only do
1766 the check at -O2 and higher optimization levels. */
1770 get_inner_reference_aff (mem1, &off1, &size1);
1771 get_inner_reference_aff (mem2, &off2, &size2);
1772 aff_combination_expand (&off1, ttae_cache);
1773 aff_combination_expand (&off2, ttae_cache);
1774 aff_combination_scale (&off1, double_int_minus_one);
1775 aff_combination_add (&off2, &off1);
1777 if (aff_comb_cannot_overlap_p (&off2, size1, size2))
1783 /* Rewrites location LOC by TMP_VAR. */
1786 rewrite_mem_ref_loc (mem_ref_loc_p loc, tree tmp_var)
1788 mark_virtual_ops_for_renaming (loc->stmt);
1789 *loc->ref = tmp_var;
1790 update_stmt (loc->stmt);
1793 /* Adds all locations of REF in LOOP and its subloops to LOCS. */
1796 get_all_locs_in_loop (struct loop *loop, mem_ref_p ref,
1797 VEC (mem_ref_loc_p, heap) **locs)
1799 mem_ref_locs_p accs;
1802 bitmap refs = VEC_index (bitmap, memory_accesses.all_refs_in_loop,
1804 struct loop *subloop;
1806 if (!bitmap_bit_p (refs, ref->id))
1809 if (VEC_length (mem_ref_locs_p, ref->accesses_in_loop)
1810 > (unsigned) loop->num)
1812 accs = VEC_index (mem_ref_locs_p, ref->accesses_in_loop, loop->num);
1815 FOR_EACH_VEC_ELT (mem_ref_loc_p, accs->locs, i, loc)
1816 VEC_safe_push (mem_ref_loc_p, heap, *locs, loc);
1820 for (subloop = loop->inner; subloop != NULL; subloop = subloop->next)
1821 get_all_locs_in_loop (subloop, ref, locs);
1824 /* Rewrites all references to REF in LOOP by variable TMP_VAR. */
1827 rewrite_mem_refs (struct loop *loop, mem_ref_p ref, tree tmp_var)
1831 VEC (mem_ref_loc_p, heap) *locs = NULL;
1833 get_all_locs_in_loop (loop, ref, &locs);
1834 FOR_EACH_VEC_ELT (mem_ref_loc_p, locs, i, loc)
1835 rewrite_mem_ref_loc (loc, tmp_var);
1836 VEC_free (mem_ref_loc_p, heap, locs);
1839 /* The name and the length of the currently generated variable
1841 #define MAX_LSM_NAME_LENGTH 40
1842 static char lsm_tmp_name[MAX_LSM_NAME_LENGTH + 1];
1843 static int lsm_tmp_name_length;
1845 /* Adds S to lsm_tmp_name. */
1848 lsm_tmp_name_add (const char *s)
1850 int l = strlen (s) + lsm_tmp_name_length;
1851 if (l > MAX_LSM_NAME_LENGTH)
1854 strcpy (lsm_tmp_name + lsm_tmp_name_length, s);
1855 lsm_tmp_name_length = l;
1858 /* Stores the name for temporary variable that replaces REF to
1862 gen_lsm_tmp_name (tree ref)
1866 switch (TREE_CODE (ref))
1869 case TARGET_MEM_REF:
1870 gen_lsm_tmp_name (TREE_OPERAND (ref, 0));
1871 lsm_tmp_name_add ("_");
1875 gen_lsm_tmp_name (TREE_OPERAND (ref, 0));
1879 case VIEW_CONVERT_EXPR:
1880 case ARRAY_RANGE_REF:
1881 gen_lsm_tmp_name (TREE_OPERAND (ref, 0));
1885 gen_lsm_tmp_name (TREE_OPERAND (ref, 0));
1886 lsm_tmp_name_add ("_RE");
1890 gen_lsm_tmp_name (TREE_OPERAND (ref, 0));
1891 lsm_tmp_name_add ("_IM");
1895 gen_lsm_tmp_name (TREE_OPERAND (ref, 0));
1896 lsm_tmp_name_add ("_");
1897 name = get_name (TREE_OPERAND (ref, 1));
1900 lsm_tmp_name_add (name);
1904 gen_lsm_tmp_name (TREE_OPERAND (ref, 0));
1905 lsm_tmp_name_add ("_I");
1909 ref = SSA_NAME_VAR (ref);
1914 name = get_name (ref);
1917 lsm_tmp_name_add (name);
1921 lsm_tmp_name_add ("S");
1925 lsm_tmp_name_add ("R");
1937 /* Determines name for temporary variable that replaces REF.
1938 The name is accumulated into the lsm_tmp_name variable.
1939 N is added to the name of the temporary. */
1942 get_lsm_tmp_name (tree ref, unsigned n)
1946 lsm_tmp_name_length = 0;
1947 gen_lsm_tmp_name (ref);
1948 lsm_tmp_name_add ("_lsm");
1953 lsm_tmp_name_add (ns);
1955 return lsm_tmp_name;
1958 struct prev_flag_edges {
1959 /* Edge to insert new flag comparison code. */
1960 edge append_cond_position;
1962 /* Edge for fall through from previous flag comparison. */
1963 edge last_cond_fallthru;
1966 /* Helper function for execute_sm. Emit code to store TMP_VAR into
1969 The store is only done if MEM has changed. We do this so no
1970 changes to MEM occur on code paths that did not originally store
1973 The common case for execute_sm will transform:
1993 This function will generate:
2012 execute_sm_if_changed (edge ex, tree mem, tree tmp_var, tree flag)
2014 basic_block new_bb, then_bb, old_dest;
2015 bool loop_has_only_one_exit;
2016 edge then_old_edge, orig_ex = ex;
2017 gimple_stmt_iterator gsi;
2019 struct prev_flag_edges *prev_edges = (struct prev_flag_edges *) ex->aux;
2021 /* ?? Insert store after previous store if applicable. See note
2024 ex = prev_edges->append_cond_position;
2026 loop_has_only_one_exit = single_pred_p (ex->dest);
2028 if (loop_has_only_one_exit)
2029 ex = split_block_after_labels (ex->dest);
2031 old_dest = ex->dest;
2032 new_bb = split_edge (ex);
2033 then_bb = create_empty_bb (new_bb);
2034 if (current_loops && new_bb->loop_father)
2035 add_bb_to_loop (then_bb, new_bb->loop_father);
2037 gsi = gsi_start_bb (new_bb);
2038 stmt = gimple_build_cond (NE_EXPR, flag, boolean_false_node,
2039 NULL_TREE, NULL_TREE);
2040 gsi_insert_after (&gsi, stmt, GSI_CONTINUE_LINKING);
2042 gsi = gsi_start_bb (then_bb);
2043 /* Insert actual store. */
2044 stmt = gimple_build_assign (unshare_expr (mem), tmp_var);
2045 gsi_insert_after (&gsi, stmt, GSI_CONTINUE_LINKING);
2047 make_edge (new_bb, then_bb, EDGE_TRUE_VALUE);
2048 make_edge (new_bb, old_dest, EDGE_FALSE_VALUE);
2049 then_old_edge = make_edge (then_bb, old_dest, EDGE_FALLTHRU);
2051 set_immediate_dominator (CDI_DOMINATORS, then_bb, new_bb);
2055 basic_block prevbb = prev_edges->last_cond_fallthru->src;
2056 redirect_edge_succ (prev_edges->last_cond_fallthru, new_bb);
2057 set_immediate_dominator (CDI_DOMINATORS, new_bb, prevbb);
2058 set_immediate_dominator (CDI_DOMINATORS, old_dest,
2059 recompute_dominator (CDI_DOMINATORS, old_dest));
2062 /* ?? Because stores may alias, they must happen in the exact
2063 sequence they originally happened. Save the position right after
2064 the (_lsm) store we just created so we can continue appending after
2065 it and maintain the original order. */
2067 struct prev_flag_edges *p;
2070 orig_ex->aux = NULL;
2071 alloc_aux_for_edge (orig_ex, sizeof (struct prev_flag_edges));
2072 p = (struct prev_flag_edges *) orig_ex->aux;
2073 p->append_cond_position = then_old_edge;
2074 p->last_cond_fallthru = find_edge (new_bb, old_dest);
2075 orig_ex->aux = (void *) p;
2078 if (!loop_has_only_one_exit)
2079 for (gsi = gsi_start_phis (old_dest); !gsi_end_p (gsi); gsi_next (&gsi))
2081 gimple phi = gsi_stmt (gsi);
2084 for (i = 0; i < gimple_phi_num_args (phi); i++)
2085 if (gimple_phi_arg_edge (phi, i)->src == new_bb)
2087 tree arg = gimple_phi_arg_def (phi, i);
2088 add_phi_arg (phi, arg, then_old_edge, UNKNOWN_LOCATION);
2092 /* Remove the original fall through edge. This was the
2093 single_succ_edge (new_bb). */
2094 EDGE_SUCC (new_bb, 0)->flags &= ~EDGE_FALLTHRU;
2097 /* Helper function for execute_sm. On every location where REF is
2098 set, set an appropriate flag indicating the store. */
2101 execute_sm_if_changed_flag_set (struct loop *loop, mem_ref_p ref)
2106 VEC (mem_ref_loc_p, heap) *locs = NULL;
2107 char *str = get_lsm_tmp_name (ref->mem, ~0);
2109 lsm_tmp_name_add ("_flag");
2110 flag = make_rename_temp (boolean_type_node, str);
2111 get_all_locs_in_loop (loop, ref, &locs);
2112 FOR_EACH_VEC_ELT (mem_ref_loc_p, locs, i, loc)
2114 gimple_stmt_iterator gsi;
2117 gsi = gsi_for_stmt (loc->stmt);
2118 stmt = gimple_build_assign (flag, boolean_true_node);
2119 gsi_insert_after (&gsi, stmt, GSI_CONTINUE_LINKING);
2121 VEC_free (mem_ref_loc_p, heap, locs);
2125 /* Executes store motion of memory reference REF from LOOP.
2126 Exits from the LOOP are stored in EXITS. The initialization of the
2127 temporary variable is put to the preheader of the loop, and assignments
2128 to the reference from the temporary variable are emitted to exits. */
2131 execute_sm (struct loop *loop, VEC (edge, heap) *exits, mem_ref_p ref)
2133 tree tmp_var, store_flag;
2136 struct fmt_data fmt_data;
2137 edge ex, latch_edge;
2138 struct lim_aux_data *lim_data;
2139 bool multi_threaded_model_p = false;
2141 if (dump_file && (dump_flags & TDF_DETAILS))
2143 fprintf (dump_file, "Executing store motion of ");
2144 print_generic_expr (dump_file, ref->mem, 0);
2145 fprintf (dump_file, " from loop %d\n", loop->num);
2148 tmp_var = make_rename_temp (TREE_TYPE (ref->mem),
2149 get_lsm_tmp_name (ref->mem, ~0));
2151 fmt_data.loop = loop;
2152 fmt_data.orig_loop = loop;
2153 for_each_index (&ref->mem, force_move_till, &fmt_data);
2155 if (block_in_transaction (loop_preheader_edge (loop)->src)
2156 || !PARAM_VALUE (PARAM_ALLOW_STORE_DATA_RACES))
2157 multi_threaded_model_p = true;
2159 if (multi_threaded_model_p)
2160 store_flag = execute_sm_if_changed_flag_set (loop, ref);
2162 rewrite_mem_refs (loop, ref, tmp_var);
2164 /* Emit the load code into the latch, so that we are sure it will
2165 be processed after all dependencies. */
2166 latch_edge = loop_latch_edge (loop);
2168 /* FIXME/TODO: For the multi-threaded variant, we could avoid this
2169 load altogether, since the store is predicated by a flag. We
2170 could, do the load only if it was originally in the loop. */
2171 load = gimple_build_assign (tmp_var, unshare_expr (ref->mem));
2172 lim_data = init_lim_data (load);
2173 lim_data->max_loop = loop;
2174 lim_data->tgt_loop = loop;
2175 gsi_insert_on_edge (latch_edge, load);
2177 if (multi_threaded_model_p)
2179 load = gimple_build_assign (store_flag, boolean_false_node);
2180 lim_data = init_lim_data (load);
2181 lim_data->max_loop = loop;
2182 lim_data->tgt_loop = loop;
2183 gsi_insert_on_edge (latch_edge, load);
2186 /* Sink the store to every exit from the loop. */
2187 FOR_EACH_VEC_ELT (edge, exits, i, ex)
2188 if (!multi_threaded_model_p)
2191 store = gimple_build_assign (unshare_expr (ref->mem), tmp_var);
2192 gsi_insert_on_edge (ex, store);
2195 execute_sm_if_changed (ex, ref->mem, tmp_var, store_flag);
2198 /* Hoists memory references MEM_REFS out of LOOP. EXITS is the list of exit
2199 edges of the LOOP. */
2202 hoist_memory_references (struct loop *loop, bitmap mem_refs,
2203 VEC (edge, heap) *exits)
2209 EXECUTE_IF_SET_IN_BITMAP (mem_refs, 0, i, bi)
2211 ref = VEC_index (mem_ref_p, memory_accesses.refs_list, i);
2212 execute_sm (loop, exits, ref);
2216 /* Returns true if REF is always accessed in LOOP. If STORED_P is true
2217 make sure REF is always stored to in LOOP. */
2220 ref_always_accessed_p (struct loop *loop, mem_ref_p ref, bool stored_p)
2222 VEC (mem_ref_loc_p, heap) *locs = NULL;
2226 struct loop *must_exec;
2229 base = get_base_address (ref->mem);
2230 if (INDIRECT_REF_P (base)
2231 || TREE_CODE (base) == MEM_REF)
2232 base = TREE_OPERAND (base, 0);
2234 get_all_locs_in_loop (loop, ref, &locs);
2235 FOR_EACH_VEC_ELT (mem_ref_loc_p, locs, i, loc)
2237 if (!get_lim_data (loc->stmt))
2240 /* If we require an always executed store make sure the statement
2241 stores to the reference. */
2245 if (!gimple_get_lhs (loc->stmt))
2247 lhs = get_base_address (gimple_get_lhs (loc->stmt));
2250 if (INDIRECT_REF_P (lhs)
2251 || TREE_CODE (lhs) == MEM_REF)
2252 lhs = TREE_OPERAND (lhs, 0);
2257 must_exec = get_lim_data (loc->stmt)->always_executed_in;
2261 if (must_exec == loop
2262 || flow_loop_nested_p (must_exec, loop))
2268 VEC_free (mem_ref_loc_p, heap, locs);
2273 /* Returns true if REF1 and REF2 are independent. */
2276 refs_independent_p (mem_ref_p ref1, mem_ref_p ref2)
2279 || bitmap_bit_p (ref1->indep_ref, ref2->id))
2281 if (bitmap_bit_p (ref1->dep_ref, ref2->id))
2283 if (!MEM_ANALYZABLE (ref1)
2284 || !MEM_ANALYZABLE (ref2))
2287 if (dump_file && (dump_flags & TDF_DETAILS))
2288 fprintf (dump_file, "Querying dependency of refs %u and %u: ",
2289 ref1->id, ref2->id);
2291 if (mem_refs_may_alias_p (ref1->mem, ref2->mem,
2292 &memory_accesses.ttae_cache))
2294 bitmap_set_bit (ref1->dep_ref, ref2->id);
2295 bitmap_set_bit (ref2->dep_ref, ref1->id);
2296 if (dump_file && (dump_flags & TDF_DETAILS))
2297 fprintf (dump_file, "dependent.\n");
2302 bitmap_set_bit (ref1->indep_ref, ref2->id);
2303 bitmap_set_bit (ref2->indep_ref, ref1->id);
2304 if (dump_file && (dump_flags & TDF_DETAILS))
2305 fprintf (dump_file, "independent.\n");
2310 /* Records the information whether REF is independent in LOOP (according
2314 record_indep_loop (struct loop *loop, mem_ref_p ref, bool indep)
2317 bitmap_set_bit (ref->indep_loop, loop->num);
2319 bitmap_set_bit (ref->dep_loop, loop->num);
2322 /* Returns true if REF is independent on all other memory references in
2326 ref_indep_loop_p_1 (struct loop *loop, mem_ref_p ref)
2328 bitmap refs_to_check;
2331 bool ret = true, stored = bitmap_bit_p (ref->stored, loop->num);
2335 refs_to_check = VEC_index (bitmap,
2336 memory_accesses.all_refs_in_loop, loop->num);
2338 refs_to_check = VEC_index (bitmap,
2339 memory_accesses.all_refs_stored_in_loop,
2342 EXECUTE_IF_SET_IN_BITMAP (refs_to_check, 0, i, bi)
2344 aref = VEC_index (mem_ref_p, memory_accesses.refs_list, i);
2345 if (!MEM_ANALYZABLE (aref)
2346 || !refs_independent_p (ref, aref))
2349 record_indep_loop (loop, aref, false);
2357 /* Returns true if REF is independent on all other memory references in
2358 LOOP. Wrapper over ref_indep_loop_p_1, caching its results. */
2361 ref_indep_loop_p (struct loop *loop, mem_ref_p ref)
2365 if (bitmap_bit_p (ref->indep_loop, loop->num))
2367 if (bitmap_bit_p (ref->dep_loop, loop->num))
2370 ret = ref_indep_loop_p_1 (loop, ref);
2372 if (dump_file && (dump_flags & TDF_DETAILS))
2373 fprintf (dump_file, "Querying dependencies of ref %u in loop %d: %s\n",
2374 ref->id, loop->num, ret ? "independent" : "dependent");
2376 record_indep_loop (loop, ref, ret);
2381 /* Returns true if we can perform store motion of REF from LOOP. */
2384 can_sm_ref_p (struct loop *loop, mem_ref_p ref)
2388 /* Can't hoist unanalyzable refs. */
2389 if (!MEM_ANALYZABLE (ref))
2392 /* Unless the reference is stored in the loop, there is nothing to do. */
2393 if (!bitmap_bit_p (ref->stored, loop->num))
2396 /* It should be movable. */
2397 if (!is_gimple_reg_type (TREE_TYPE (ref->mem))
2398 || TREE_THIS_VOLATILE (ref->mem)
2399 || !for_each_index (&ref->mem, may_move_till, loop))
2402 /* If it can throw fail, we do not properly update EH info. */
2403 if (tree_could_throw_p (ref->mem))
2406 /* If it can trap, it must be always executed in LOOP.
2407 Readonly memory locations may trap when storing to them, but
2408 tree_could_trap_p is a predicate for rvalues, so check that
2410 base = get_base_address (ref->mem);
2411 if ((tree_could_trap_p (ref->mem)
2412 || (DECL_P (base) && TREE_READONLY (base)))
2413 && !ref_always_accessed_p (loop, ref, true))
2416 /* And it must be independent on all other memory references
2418 if (!ref_indep_loop_p (loop, ref))
2424 /* Marks the references in LOOP for that store motion should be performed
2425 in REFS_TO_SM. SM_EXECUTED is the set of references for that store
2426 motion was performed in one of the outer loops. */
2429 find_refs_for_sm (struct loop *loop, bitmap sm_executed, bitmap refs_to_sm)
2431 bitmap refs = VEC_index (bitmap, memory_accesses.all_refs_in_loop,
2437 EXECUTE_IF_AND_COMPL_IN_BITMAP (refs, sm_executed, 0, i, bi)
2439 ref = VEC_index (mem_ref_p, memory_accesses.refs_list, i);
2440 if (can_sm_ref_p (loop, ref))
2441 bitmap_set_bit (refs_to_sm, i);
2445 /* Checks whether LOOP (with exits stored in EXITS array) is suitable
2446 for a store motion optimization (i.e. whether we can insert statement
2450 loop_suitable_for_sm (struct loop *loop ATTRIBUTE_UNUSED,
2451 VEC (edge, heap) *exits)
2456 FOR_EACH_VEC_ELT (edge, exits, i, ex)
2457 if (ex->flags & (EDGE_ABNORMAL | EDGE_EH))
2463 /* Try to perform store motion for all memory references modified inside
2464 LOOP. SM_EXECUTED is the bitmap of the memory references for that
2465 store motion was executed in one of the outer loops. */
2468 store_motion_loop (struct loop *loop, bitmap sm_executed)
2470 VEC (edge, heap) *exits = get_loop_exit_edges (loop);
2471 struct loop *subloop;
2472 bitmap sm_in_loop = BITMAP_ALLOC (NULL);
2474 if (loop_suitable_for_sm (loop, exits))
2476 find_refs_for_sm (loop, sm_executed, sm_in_loop);
2477 hoist_memory_references (loop, sm_in_loop, exits);
2479 VEC_free (edge, heap, exits);
2481 bitmap_ior_into (sm_executed, sm_in_loop);
2482 for (subloop = loop->inner; subloop != NULL; subloop = subloop->next)
2483 store_motion_loop (subloop, sm_executed);
2484 bitmap_and_compl_into (sm_executed, sm_in_loop);
2485 BITMAP_FREE (sm_in_loop);
2488 /* Try to perform store motion for all memory references modified inside
2495 bitmap sm_executed = BITMAP_ALLOC (NULL);
2497 for (loop = current_loops->tree_root->inner; loop != NULL; loop = loop->next)
2498 store_motion_loop (loop, sm_executed);
2500 BITMAP_FREE (sm_executed);
2501 gsi_commit_edge_inserts ();
2504 /* Fills ALWAYS_EXECUTED_IN information for basic blocks of LOOP, i.e.
2505 for each such basic block bb records the outermost loop for that execution
2506 of its header implies execution of bb. CONTAINS_CALL is the bitmap of
2507 blocks that contain a nonpure call. */
2510 fill_always_executed_in (struct loop *loop, sbitmap contains_call)
2512 basic_block bb = NULL, *bbs, last = NULL;
2515 struct loop *inn_loop = loop;
2517 if (ALWAYS_EXECUTED_IN (loop->header) == NULL)
2519 bbs = get_loop_body_in_dom_order (loop);
2521 for (i = 0; i < loop->num_nodes; i++)
2526 if (dominated_by_p (CDI_DOMINATORS, loop->latch, bb))
2529 if (TEST_BIT (contains_call, bb->index))
2532 FOR_EACH_EDGE (e, ei, bb->succs)
2533 if (!flow_bb_inside_loop_p (loop, e->dest))
2538 /* A loop might be infinite (TODO use simple loop analysis
2539 to disprove this if possible). */
2540 if (bb->flags & BB_IRREDUCIBLE_LOOP)
2543 if (!flow_bb_inside_loop_p (inn_loop, bb))
2546 if (bb->loop_father->header == bb)
2548 if (!dominated_by_p (CDI_DOMINATORS, loop->latch, bb))
2551 /* In a loop that is always entered we may proceed anyway.
2552 But record that we entered it and stop once we leave it. */
2553 inn_loop = bb->loop_father;
2559 SET_ALWAYS_EXECUTED_IN (last, loop);
2560 if (last == loop->header)
2562 last = get_immediate_dominator (CDI_DOMINATORS, last);
2568 for (loop = loop->inner; loop; loop = loop->next)
2569 fill_always_executed_in (loop, contains_call);
2572 /* Compute the global information needed by the loop invariant motion pass. */
2575 tree_ssa_lim_initialize (void)
2577 sbitmap contains_call = sbitmap_alloc (last_basic_block);
2578 gimple_stmt_iterator bsi;
2582 sbitmap_zero (contains_call);
2585 for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi))
2587 if (nonpure_call_p (gsi_stmt (bsi)))
2591 if (!gsi_end_p (bsi))
2592 SET_BIT (contains_call, bb->index);
2595 for (loop = current_loops->tree_root->inner; loop; loop = loop->next)
2596 fill_always_executed_in (loop, contains_call);
2598 sbitmap_free (contains_call);
2600 lim_aux_data_map = pointer_map_create ();
2603 compute_transaction_bits ();
2605 alloc_aux_for_edges (0);
2608 /* Cleans up after the invariant motion pass. */
2611 tree_ssa_lim_finalize (void)
2618 free_aux_for_edges ();
2621 SET_ALWAYS_EXECUTED_IN (bb, NULL);
2623 pointer_map_destroy (lim_aux_data_map);
2625 htab_delete (memory_accesses.refs);
2627 FOR_EACH_VEC_ELT (mem_ref_p, memory_accesses.refs_list, i, ref)
2629 VEC_free (mem_ref_p, heap, memory_accesses.refs_list);
2631 FOR_EACH_VEC_ELT (bitmap, memory_accesses.refs_in_loop, i, b)
2633 VEC_free (bitmap, heap, memory_accesses.refs_in_loop);
2635 FOR_EACH_VEC_ELT (bitmap, memory_accesses.all_refs_in_loop, i, b)
2637 VEC_free (bitmap, heap, memory_accesses.all_refs_in_loop);
2639 FOR_EACH_VEC_ELT (bitmap, memory_accesses.all_refs_stored_in_loop, i, b)
2641 VEC_free (bitmap, heap, memory_accesses.all_refs_stored_in_loop);
2643 if (memory_accesses.ttae_cache)
2644 free_affine_expand_cache (&memory_accesses.ttae_cache);
2647 /* Moves invariants from loops. Only "expensive" invariants are moved out --
2648 i.e. those that are likely to be win regardless of the register pressure. */
2655 tree_ssa_lim_initialize ();
2657 /* Gathers information about memory accesses in the loops. */
2658 analyze_memory_references ();
2660 /* For each statement determine the outermost loop in that it is
2661 invariant and cost for computing the invariant. */
2662 determine_invariantness ();
2664 /* Execute store motion. Force the necessary invariants to be moved
2665 out of the loops as well. */
2668 /* Move the expressions that are expensive enough. */
2669 todo = move_computations ();
2671 tree_ssa_lim_finalize ();