1 /* Alias analysis for trees.
2 Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009
3 Free Software Foundation, Inc.
4 Contributed by Diego Novillo <dnovillo@redhat.com>
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
24 #include "coretypes.h"
29 #include "hard-reg-set.h"
30 #include "basic-block.h"
34 #include "langhooks.h"
37 #include "diagnostic.h"
38 #include "tree-dump.h"
40 #include "tree-flow.h"
41 #include "tree-inline.h"
42 #include "tree-pass.h"
45 #include "ipa-type-escape.h"
49 #include "pointer-set.h"
50 #include "alloc-pool.h"
51 #include "tree-ssa-alias.h"
53 /* Broad overview of how alias analysis on gimple works:
55 Statements clobbering or using memory are linked through the
56 virtual operand factored use-def chain. The virtual operand
57 is unique per function, its symbol is accessible via gimple_vop (cfun).
58 Virtual operands are used for efficiently walking memory statements
59 in the gimple IL and are useful for things like value-numbering as
60 a generation count for memory references.
62 SSA_NAME pointers may have associated points-to information
63 accessible via the SSA_NAME_PTR_INFO macro. Flow-insensitive
64 points-to information is (re-)computed by the TODO_rebuild_alias
65 pass manager todo. Points-to information is also used for more
66 precise tracking of call-clobbered and call-used variables and
67 related disambiguations.
69 This file contains functions for disambiguating memory references,
70 the so called alias-oracle and tools for walking of the gimple IL.
72 The main alias-oracle entry-points are
74 bool stmt_may_clobber_ref_p (gimple, tree)
76 This function queries if a statement may invalidate (parts of)
77 the memory designated by the reference tree argument.
79 bool ref_maybe_used_by_stmt_p (gimple, tree)
81 This function queries if a statement may need (parts of) the
82 memory designated by the reference tree argument.
84 There are variants of these functions that only handle the call
85 part of a statement, call_may_clobber_ref_p and ref_maybe_used_by_call_p.
86 Note that these do not disambiguate against a possible call lhs.
88 bool refs_may_alias_p (tree, tree)
90 This function tries to disambiguate two reference trees.
92 bool ptr_deref_may_alias_global_p (tree)
94 This function queries if dereferencing a pointer variable may
97 More low-level disambiguators are available and documented in
98 this file. Low-level disambiguators dealing with points-to
99 information are in tree-ssa-structalias.c. */
102 /* Query statistics for the different low-level disambiguators.
103 A high-level query may trigger multiple of them. */
106 unsigned HOST_WIDE_INT refs_may_alias_p_may_alias
;
107 unsigned HOST_WIDE_INT refs_may_alias_p_no_alias
;
108 unsigned HOST_WIDE_INT ref_maybe_used_by_call_p_may_alias
;
109 unsigned HOST_WIDE_INT ref_maybe_used_by_call_p_no_alias
;
110 unsigned HOST_WIDE_INT call_may_clobber_ref_p_may_alias
;
111 unsigned HOST_WIDE_INT call_may_clobber_ref_p_no_alias
;
115 dump_alias_stats (FILE *s
)
117 fprintf (s
, "\nAlias oracle query stats:\n");
118 fprintf (s
, " refs_may_alias_p: "
119 HOST_WIDE_INT_PRINT_DEC
" disambiguations, "
120 HOST_WIDE_INT_PRINT_DEC
" queries\n",
121 alias_stats
.refs_may_alias_p_no_alias
,
122 alias_stats
.refs_may_alias_p_no_alias
123 + alias_stats
.refs_may_alias_p_may_alias
);
124 fprintf (s
, " ref_maybe_used_by_call_p: "
125 HOST_WIDE_INT_PRINT_DEC
" disambiguations, "
126 HOST_WIDE_INT_PRINT_DEC
" queries\n",
127 alias_stats
.ref_maybe_used_by_call_p_no_alias
,
128 alias_stats
.refs_may_alias_p_no_alias
129 + alias_stats
.ref_maybe_used_by_call_p_may_alias
);
130 fprintf (s
, " call_may_clobber_ref_p: "
131 HOST_WIDE_INT_PRINT_DEC
" disambiguations, "
132 HOST_WIDE_INT_PRINT_DEC
" queries\n",
133 alias_stats
.call_may_clobber_ref_p_no_alias
,
134 alias_stats
.call_may_clobber_ref_p_no_alias
135 + alias_stats
.call_may_clobber_ref_p_may_alias
);
139 /* Return true, if dereferencing PTR may alias with a global variable. */
142 ptr_deref_may_alias_global_p (tree ptr
)
144 struct ptr_info_def
*pi
;
146 /* If we end up with a pointer constant here that may point
148 if (TREE_CODE (ptr
) != SSA_NAME
)
151 pi
= SSA_NAME_PTR_INFO (ptr
);
153 /* If we do not have points-to information for this variable,
158 /* ??? This does not use TBAA to prune globals ptr may not access. */
159 return pt_solution_includes_global (&pi
->pt
);
162 /* Return true if dereferencing PTR may alias DECL.
163 The caller is responsible for applying TBAA to see if PTR
164 may access DECL at all. */
167 ptr_deref_may_alias_decl_p (tree ptr
, tree decl
)
169 struct ptr_info_def
*pi
;
171 gcc_assert ((TREE_CODE (ptr
) == SSA_NAME
172 || TREE_CODE (ptr
) == ADDR_EXPR
173 || TREE_CODE (ptr
) == INTEGER_CST
)
174 && (TREE_CODE (decl
) == VAR_DECL
175 || TREE_CODE (decl
) == PARM_DECL
176 || TREE_CODE (decl
) == RESULT_DECL
));
178 /* Non-aliased variables can not be pointed to. */
179 if (!may_be_aliased (decl
))
182 /* ADDR_EXPR pointers either just offset another pointer or directly
183 specify the pointed-to set. */
184 if (TREE_CODE (ptr
) == ADDR_EXPR
)
186 tree base
= get_base_address (TREE_OPERAND (ptr
, 0));
188 && INDIRECT_REF_P (base
))
189 ptr
= TREE_OPERAND (base
, 0);
192 return operand_equal_p (base
, decl
, 0);
194 && CONSTANT_CLASS_P (base
))
200 /* We can end up with dereferencing constant pointers.
201 Just bail out in this case. */
202 if (TREE_CODE (ptr
) == INTEGER_CST
)
205 /* If we do not have useful points-to information for this pointer
206 we cannot disambiguate anything else. */
207 pi
= SSA_NAME_PTR_INFO (ptr
);
211 return pt_solution_includes (&pi
->pt
, decl
);
214 /* Return true if dereferenced PTR1 and PTR2 may alias.
215 The caller is responsible for applying TBAA to see if accesses
216 through PTR1 and PTR2 may conflict at all. */
219 ptr_derefs_may_alias_p (tree ptr1
, tree ptr2
)
221 struct ptr_info_def
*pi1
, *pi2
;
223 gcc_assert ((TREE_CODE (ptr1
) == SSA_NAME
224 || TREE_CODE (ptr1
) == ADDR_EXPR
225 || TREE_CODE (ptr1
) == INTEGER_CST
)
226 && (TREE_CODE (ptr2
) == SSA_NAME
227 || TREE_CODE (ptr2
) == ADDR_EXPR
228 || TREE_CODE (ptr2
) == INTEGER_CST
));
230 /* ADDR_EXPR pointers either just offset another pointer or directly
231 specify the pointed-to set. */
232 if (TREE_CODE (ptr1
) == ADDR_EXPR
)
234 tree base
= get_base_address (TREE_OPERAND (ptr1
, 0));
236 && INDIRECT_REF_P (base
))
237 ptr1
= TREE_OPERAND (base
, 0);
240 return ptr_deref_may_alias_decl_p (ptr2
, base
);
244 if (TREE_CODE (ptr2
) == ADDR_EXPR
)
246 tree base
= get_base_address (TREE_OPERAND (ptr2
, 0));
248 && INDIRECT_REF_P (base
))
249 ptr2
= TREE_OPERAND (base
, 0);
252 return ptr_deref_may_alias_decl_p (ptr1
, base
);
257 /* We can end up with dereferencing constant pointers.
258 Just bail out in this case. */
259 if (TREE_CODE (ptr1
) == INTEGER_CST
260 || TREE_CODE (ptr2
) == INTEGER_CST
)
263 /* We may end up with two empty points-to solutions for two same pointers.
264 In this case we still want to say both pointers alias, so shortcut
269 /* If we do not have useful points-to information for either pointer
270 we cannot disambiguate anything else. */
271 pi1
= SSA_NAME_PTR_INFO (ptr1
);
272 pi2
= SSA_NAME_PTR_INFO (ptr2
);
276 /* If both pointers are restrict-qualified try to disambiguate
277 with restrict information. */
278 if (TYPE_RESTRICT (TREE_TYPE (ptr1
))
279 && TYPE_RESTRICT (TREE_TYPE (ptr2
))
280 && !pt_solutions_same_restrict_base (&pi1
->pt
, &pi2
->pt
))
283 /* ??? This does not use TBAA to prune decls from the intersection
284 that not both pointers may access. */
285 return pt_solutions_intersect (&pi1
->pt
, &pi2
->pt
);
288 /* Return true if dereferencing PTR may alias *REF.
289 The caller is responsible for applying TBAA to see if PTR
290 may access *REF at all. */
293 ptr_deref_may_alias_ref_p_1 (tree ptr
, ao_ref
*ref
)
295 tree base
= ao_ref_base (ref
);
297 if (INDIRECT_REF_P (base
))
298 return ptr_derefs_may_alias_p (ptr
, TREE_OPERAND (base
, 0));
299 else if (SSA_VAR_P (base
))
300 return ptr_deref_may_alias_decl_p (ptr
, base
);
306 /* Dump alias information on FILE. */
309 dump_alias_info (FILE *file
)
313 = lang_hooks
.decl_printable_name (current_function_decl
, 2);
314 referenced_var_iterator rvi
;
317 fprintf (file
, "\n\nAlias information for %s\n\n", funcname
);
319 fprintf (file
, "Aliased symbols\n\n");
321 FOR_EACH_REFERENCED_VAR (var
, rvi
)
323 if (may_be_aliased (var
))
324 dump_variable (file
, var
);
327 fprintf (file
, "\nCall clobber information\n");
329 fprintf (file
, "\nESCAPED");
330 dump_points_to_solution (file
, &cfun
->gimple_df
->escaped
);
331 fprintf (file
, "\nCALLUSED");
332 dump_points_to_solution (file
, &cfun
->gimple_df
->callused
);
334 fprintf (file
, "\n\nFlow-insensitive points-to information\n\n");
336 for (i
= 1; i
< num_ssa_names
; i
++)
338 tree ptr
= ssa_name (i
);
339 struct ptr_info_def
*pi
;
342 || SSA_NAME_IN_FREE_LIST (ptr
))
345 pi
= SSA_NAME_PTR_INFO (ptr
);
347 dump_points_to_info_for (file
, ptr
);
350 fprintf (file
, "\n");
354 /* Dump alias information on stderr. */
357 debug_alias_info (void)
359 dump_alias_info (stderr
);
363 /* Return the alias information associated with pointer T. It creates a
364 new instance if none existed. */
366 struct ptr_info_def
*
367 get_ptr_info (tree t
)
369 struct ptr_info_def
*pi
;
371 gcc_assert (POINTER_TYPE_P (TREE_TYPE (t
)));
373 pi
= SSA_NAME_PTR_INFO (t
);
376 pi
= GGC_CNEW (struct ptr_info_def
);
377 pt_solution_reset (&pi
->pt
);
378 SSA_NAME_PTR_INFO (t
) = pi
;
384 /* Dump the points-to set *PT into FILE. */
387 dump_points_to_solution (FILE *file
, struct pt_solution
*pt
)
390 fprintf (file
, ", points-to anything");
393 fprintf (file
, ", points-to non-local");
396 fprintf (file
, ", points-to escaped");
399 fprintf (file
, ", points-to NULL");
403 fprintf (file
, ", points-to vars: ");
404 dump_decl_set (file
, pt
->vars
);
405 if (pt
->vars_contains_global
)
406 fprintf (file
, " (includes global vars)");
410 /* Dump points-to information for SSA_NAME PTR into FILE. */
413 dump_points_to_info_for (FILE *file
, tree ptr
)
415 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (ptr
);
417 print_generic_expr (file
, ptr
, dump_flags
);
420 dump_points_to_solution (file
, &pi
->pt
);
422 fprintf (file
, ", points-to anything");
424 fprintf (file
, "\n");
428 /* Dump points-to information for VAR into stderr. */
431 debug_points_to_info_for (tree var
)
433 dump_points_to_info_for (stderr
, var
);
437 /* Initializes the alias-oracle reference representation *R from REF. */
440 ao_ref_init (ao_ref
*r
, tree ref
)
447 r
->ref_alias_set
= -1;
448 r
->base_alias_set
= -1;
451 /* Returns the base object of the memory reference *REF. */
454 ao_ref_base (ao_ref
*ref
)
458 ref
->base
= get_ref_base_and_extent (ref
->ref
, &ref
->offset
, &ref
->size
,
463 /* Returns the base object alias set of the memory reference *REF. */
465 static alias_set_type ATTRIBUTE_UNUSED
466 ao_ref_base_alias_set (ao_ref
*ref
)
468 if (ref
->base_alias_set
!= -1)
469 return ref
->base_alias_set
;
470 ref
->base_alias_set
= get_alias_set (ao_ref_base (ref
));
471 return ref
->base_alias_set
;
474 /* Returns the reference alias set of the memory reference *REF. */
477 ao_ref_alias_set (ao_ref
*ref
)
479 if (ref
->ref_alias_set
!= -1)
480 return ref
->ref_alias_set
;
481 ref
->ref_alias_set
= get_alias_set (ref
->ref
);
482 return ref
->ref_alias_set
;
485 /* Init an alias-oracle reference representation from a gimple pointer
486 PTR and a gimple size SIZE in bytes. If SIZE is NULL_TREE the the
487 size is assumed to be unknown. The access is assumed to be only
488 to or after of the pointer target, not before it. */
491 ao_ref_init_from_ptr_and_size (ao_ref
*ref
, tree ptr
, tree size
)
493 HOST_WIDE_INT t1
, t2
;
494 ref
->ref
= NULL_TREE
;
495 if (TREE_CODE (ptr
) == ADDR_EXPR
)
496 ref
->base
= get_ref_base_and_extent (TREE_OPERAND (ptr
, 0),
497 &ref
->offset
, &t1
, &t2
);
500 ref
->base
= build1 (INDIRECT_REF
, char_type_node
, ptr
);
504 && host_integerp (size
, 0)
505 && TREE_INT_CST_LOW (size
) * 8 / 8 == TREE_INT_CST_LOW (size
))
506 ref
->max_size
= ref
->size
= TREE_INT_CST_LOW (size
) * 8;
508 ref
->max_size
= ref
->size
= -1;
509 ref
->ref_alias_set
= 0;
510 ref
->base_alias_set
= 0;
513 /* Return 1 if TYPE1 and TYPE2 are to be considered equivalent for the
514 purpose of TBAA. Return 0 if they are distinct and -1 if we cannot
518 same_type_for_tbaa (tree type1
, tree type2
)
520 type1
= TYPE_MAIN_VARIANT (type1
);
521 type2
= TYPE_MAIN_VARIANT (type2
);
523 /* If we would have to do structural comparison bail out. */
524 if (TYPE_STRUCTURAL_EQUALITY_P (type1
)
525 || TYPE_STRUCTURAL_EQUALITY_P (type2
))
528 /* Compare the canonical types. */
529 if (TYPE_CANONICAL (type1
) == TYPE_CANONICAL (type2
))
532 /* ??? Array types are not properly unified in all cases as we have
533 spurious changes in the index types for example. Removing this
534 causes all sorts of problems with the Fortran frontend. */
535 if (TREE_CODE (type1
) == ARRAY_TYPE
536 && TREE_CODE (type2
) == ARRAY_TYPE
)
539 /* The types are known to be not equal. */
543 /* Determine if the two component references REF1 and REF2 which are
544 based on access types TYPE1 and TYPE2 and of which at least one is based
545 on an indirect reference may alias. */
548 nonaliasing_component_refs_p (tree ref1
, tree type1
,
549 HOST_WIDE_INT offset1
, HOST_WIDE_INT max_size1
,
550 tree ref2
, tree type2
,
551 HOST_WIDE_INT offset2
, HOST_WIDE_INT max_size2
)
553 /* If one reference is a component references through pointers try to find a
554 common base and apply offset based disambiguation. This handles
556 struct A { int i; int j; } *q;
557 struct B { struct A a; int k; } *p;
558 disambiguating q->i and p->a.j. */
562 /* Now search for the type1 in the access path of ref2. This
563 would be a common base for doing offset based disambiguation on. */
565 while (handled_component_p (*refp
)
566 && same_type_for_tbaa (TREE_TYPE (*refp
), type1
) == 0)
567 refp
= &TREE_OPERAND (*refp
, 0);
568 same_p
= same_type_for_tbaa (TREE_TYPE (*refp
), type1
);
569 /* If we couldn't compare types we have to bail out. */
572 else if (same_p
== 1)
574 HOST_WIDE_INT offadj
, sztmp
, msztmp
;
575 get_ref_base_and_extent (*refp
, &offadj
, &sztmp
, &msztmp
);
577 return ranges_overlap_p (offset1
, max_size1
, offset2
, max_size2
);
579 /* If we didn't find a common base, try the other way around. */
581 while (handled_component_p (*refp
)
582 && same_type_for_tbaa (TREE_TYPE (*refp
), type2
) == 0)
583 refp
= &TREE_OPERAND (*refp
, 0);
584 same_p
= same_type_for_tbaa (TREE_TYPE (*refp
), type2
);
585 /* If we couldn't compare types we have to bail out. */
588 else if (same_p
== 1)
590 HOST_WIDE_INT offadj
, sztmp
, msztmp
;
591 get_ref_base_and_extent (*refp
, &offadj
, &sztmp
, &msztmp
);
593 return ranges_overlap_p (offset1
, max_size1
, offset2
, max_size2
);
595 /* If we have two type access paths B1.path1 and B2.path2 they may
596 only alias if either B1 is in B2.path2 or B2 is in B1.path1. */
600 /* Return true if two memory references based on the variables BASE1
601 and BASE2 constrained to [OFFSET1, OFFSET1 + MAX_SIZE1) and
602 [OFFSET2, OFFSET2 + MAX_SIZE2) may alias. */
605 decl_refs_may_alias_p (tree base1
,
606 HOST_WIDE_INT offset1
, HOST_WIDE_INT max_size1
,
608 HOST_WIDE_INT offset2
, HOST_WIDE_INT max_size2
)
610 gcc_assert (SSA_VAR_P (base1
) && SSA_VAR_P (base2
));
612 /* If both references are based on different variables, they cannot alias. */
613 if (!operand_equal_p (base1
, base2
, 0))
616 /* If both references are based on the same variable, they cannot alias if
617 the accesses do not overlap. */
618 return ranges_overlap_p (offset1
, max_size1
, offset2
, max_size2
);
621 /* Return true if an indirect reference based on *PTR1 constrained
622 to [OFFSET1, OFFSET1 + MAX_SIZE1) may alias a variable based on BASE2
623 constrained to [OFFSET2, OFFSET2 + MAX_SIZE2). *PTR1 and BASE2 have
624 the alias sets BASE1_ALIAS_SET and BASE2_ALIAS_SET which can be -1
625 in which case they are computed on-demand. REF1 and REF2
626 if non-NULL are the complete memory reference trees. */
629 indirect_ref_may_alias_decl_p (tree ref1
, tree ptr1
,
630 HOST_WIDE_INT offset1
, HOST_WIDE_INT max_size1
,
631 alias_set_type base1_alias_set
,
632 tree ref2
, tree base2
,
633 HOST_WIDE_INT offset2
, HOST_WIDE_INT max_size2
,
634 alias_set_type base2_alias_set
)
636 /* If only one reference is based on a variable, they cannot alias if
637 the pointer access is beyond the extent of the variable access.
638 (the pointer base cannot validly point to an offset less than zero
640 They also cannot alias if the pointer may not point to the decl. */
642 && !ranges_overlap_p (offset1
, max_size1
, 0, offset2
+ max_size2
))
644 if (!ptr_deref_may_alias_decl_p (ptr1
, base2
))
647 /* Disambiguations that rely on strict aliasing rules follow. */
648 if (!flag_strict_aliasing
)
651 /* If the alias set for a pointer access is zero all bets are off. */
652 if (base1_alias_set
== -1)
653 base1_alias_set
= get_deref_alias_set (ptr1
);
654 if (base1_alias_set
== 0)
656 if (base2_alias_set
== -1)
657 base2_alias_set
= get_alias_set (base2
);
659 /* If both references are through the same type, they do not alias
660 if the accesses do not overlap. This does extra disambiguation
661 for mixed/pointer accesses but requires strict aliasing. */
662 if (same_type_for_tbaa (TREE_TYPE (TREE_TYPE (ptr1
)),
663 TREE_TYPE (base2
)) == 1)
664 return ranges_overlap_p (offset1
, max_size1
, offset2
, max_size2
);
666 /* The only way to access a variable is through a pointer dereference
667 of the same alias set or a subset of it. */
668 if (base1_alias_set
!= base2_alias_set
669 && !alias_set_subset_of (base1_alias_set
, base2_alias_set
))
672 /* Do access-path based disambiguation. */
674 && handled_component_p (ref1
)
675 && handled_component_p (ref2
))
676 return nonaliasing_component_refs_p (ref1
, TREE_TYPE (TREE_TYPE (ptr1
)),
678 ref2
, TREE_TYPE (base2
),
684 /* Return true if two indirect references based on *PTR1
685 and *PTR2 constrained to [OFFSET1, OFFSET1 + MAX_SIZE1) and
686 [OFFSET2, OFFSET2 + MAX_SIZE2) may alias. *PTR1 and *PTR2 have
687 the alias sets BASE1_ALIAS_SET and BASE2_ALIAS_SET which can be -1
688 in which case they are computed on-demand. REF1 and REF2
689 if non-NULL are the complete memory reference trees. */
692 indirect_refs_may_alias_p (tree ref1
, tree ptr1
,
693 HOST_WIDE_INT offset1
, HOST_WIDE_INT max_size1
,
694 alias_set_type base1_alias_set
,
695 tree ref2
, tree ptr2
,
696 HOST_WIDE_INT offset2
, HOST_WIDE_INT max_size2
,
697 alias_set_type base2_alias_set
)
699 /* If both bases are based on pointers they cannot alias if they may not
700 point to the same memory object or if they point to the same object
701 and the accesses do not overlap. */
702 if (operand_equal_p (ptr1
, ptr2
, 0))
703 return ranges_overlap_p (offset1
, max_size1
, offset2
, max_size2
);
704 if (!ptr_derefs_may_alias_p (ptr1
, ptr2
))
707 /* Disambiguations that rely on strict aliasing rules follow. */
708 if (!flag_strict_aliasing
)
711 /* If the alias set for a pointer access is zero all bets are off. */
712 if (base1_alias_set
== -1)
713 base1_alias_set
= get_deref_alias_set (ptr1
);
714 if (base1_alias_set
== 0)
716 if (base2_alias_set
== -1)
717 base2_alias_set
= get_deref_alias_set (ptr2
);
718 if (base2_alias_set
== 0)
721 /* If both references are through the same type, they do not alias
722 if the accesses do not overlap. This does extra disambiguation
723 for mixed/pointer accesses but requires strict aliasing. */
724 if (same_type_for_tbaa (TREE_TYPE (TREE_TYPE (ptr1
)),
725 TREE_TYPE (TREE_TYPE (ptr2
))) == 1)
726 return ranges_overlap_p (offset1
, max_size1
, offset2
, max_size2
);
728 /* Do type-based disambiguation. */
729 if (base1_alias_set
!= base2_alias_set
730 && !alias_sets_conflict_p (base1_alias_set
, base2_alias_set
))
733 /* Do access-path based disambiguation. */
735 && handled_component_p (ref1
)
736 && handled_component_p (ref2
))
737 return nonaliasing_component_refs_p (ref1
, TREE_TYPE (TREE_TYPE (ptr1
)),
739 ref2
, TREE_TYPE (TREE_TYPE (ptr2
)),
745 /* Return true, if the two memory references REF1 and REF2 may alias. */
748 refs_may_alias_p_1 (ao_ref
*ref1
, ao_ref
*ref2
, bool tbaa_p
)
751 HOST_WIDE_INT offset1
= 0, offset2
= 0;
752 HOST_WIDE_INT size1
= -1, size2
= -1;
753 HOST_WIDE_INT max_size1
= -1, max_size2
= -1;
754 bool var1_p
, var2_p
, ind1_p
, ind2_p
;
757 gcc_assert ((!ref1
->ref
758 || SSA_VAR_P (ref1
->ref
)
759 || handled_component_p (ref1
->ref
)
760 || INDIRECT_REF_P (ref1
->ref
)
761 || TREE_CODE (ref1
->ref
) == TARGET_MEM_REF
)
763 || SSA_VAR_P (ref2
->ref
)
764 || handled_component_p (ref2
->ref
)
765 || INDIRECT_REF_P (ref2
->ref
)
766 || TREE_CODE (ref2
->ref
) == TARGET_MEM_REF
));
768 /* Decompose the references into their base objects and the access. */
769 base1
= ao_ref_base (ref1
);
770 offset1
= ref1
->offset
;
772 max_size1
= ref1
->max_size
;
773 base2
= ao_ref_base (ref2
);
774 offset2
= ref2
->offset
;
776 max_size2
= ref2
->max_size
;
778 /* We can end up with registers or constants as bases for example from
779 *D.1663_44 = VIEW_CONVERT_EXPR<struct DB_LSN>(__tmp$B0F64_59);
780 which is seen as a struct copy. */
781 if (TREE_CODE (base1
) == SSA_NAME
782 || TREE_CODE (base2
) == SSA_NAME
783 || is_gimple_min_invariant (base1
)
784 || is_gimple_min_invariant (base2
))
787 /* Defer to simple offset based disambiguation if we have
788 references based on two decls. Do this before defering to
789 TBAA to handle must-alias cases in conformance with the
790 GCC extension of allowing type-punning through unions. */
791 var1_p
= SSA_VAR_P (base1
);
792 var2_p
= SSA_VAR_P (base2
);
793 if (var1_p
&& var2_p
)
794 return decl_refs_may_alias_p (base1
, offset1
, max_size1
,
795 base2
, offset2
, max_size2
);
797 /* First defer to TBAA if possible. */
799 && flag_strict_aliasing
800 && !alias_sets_conflict_p (ao_ref_alias_set (ref1
),
801 ao_ref_alias_set (ref2
)))
804 /* If one reference is a TARGET_MEM_REF weird things are allowed. Still
805 TBAA disambiguation based on the access type is possible, so bail
806 out only after that check. */
807 if ((ref1
->ref
&& TREE_CODE (ref1
->ref
) == TARGET_MEM_REF
)
808 || (ref2
->ref
&& TREE_CODE (ref2
->ref
) == TARGET_MEM_REF
))
811 /* Dispatch to the pointer-vs-decl or pointer-vs-pointer disambiguators. */
812 ind1_p
= INDIRECT_REF_P (base1
);
813 ind2_p
= INDIRECT_REF_P (base2
);
814 set
= tbaa_p
? -1 : 0;
815 if (var1_p
&& ind2_p
)
816 return indirect_ref_may_alias_decl_p (ref2
->ref
, TREE_OPERAND (base2
, 0),
817 offset2
, max_size2
, set
,
819 offset1
, max_size1
, set
);
820 else if (ind1_p
&& var2_p
)
821 return indirect_ref_may_alias_decl_p (ref1
->ref
, TREE_OPERAND (base1
, 0),
822 offset1
, max_size1
, set
,
824 offset2
, max_size2
, set
);
825 else if (ind1_p
&& ind2_p
)
826 return indirect_refs_may_alias_p (ref1
->ref
, TREE_OPERAND (base1
, 0),
827 offset1
, max_size1
, set
,
828 ref2
->ref
, TREE_OPERAND (base2
, 0),
829 offset2
, max_size2
, set
);
835 refs_may_alias_p (tree ref1
, tree ref2
)
839 ao_ref_init (&r1
, ref1
);
840 ao_ref_init (&r2
, ref2
);
841 res
= refs_may_alias_p_1 (&r1
, &r2
, true);
843 ++alias_stats
.refs_may_alias_p_may_alias
;
845 ++alias_stats
.refs_may_alias_p_no_alias
;
849 /* Returns true if there is a anti-dependence for the STORE that
850 executes after the LOAD. */
853 refs_anti_dependent_p (tree load
, tree store
)
856 ao_ref_init (&r1
, load
);
857 ao_ref_init (&r2
, store
);
858 return refs_may_alias_p_1 (&r1
, &r2
, false);
861 /* Returns true if there is a output dependence for the stores
862 STORE1 and STORE2. */
865 refs_output_dependent_p (tree store1
, tree store2
)
868 ao_ref_init (&r1
, store1
);
869 ao_ref_init (&r2
, store2
);
870 return refs_may_alias_p_1 (&r1
, &r2
, false);
873 /* If the call CALL may use the memory reference REF return true,
874 otherwise return false. */
877 ref_maybe_used_by_call_p_1 (gimple call
, ao_ref
*ref
)
881 int flags
= gimple_call_flags (call
);
883 /* Const functions without a static chain do not implicitly use memory. */
884 if (!gimple_call_chain (call
)
885 && (flags
& (ECF_CONST
|ECF_NOVOPS
)))
888 base
= ao_ref_base (ref
);
892 /* If the reference is based on a decl that is not aliased the call
893 cannot possibly use it. */
895 && !may_be_aliased (base
)
896 /* But local statics can be used through recursion. */
897 && !is_global_var (base
))
900 callee
= gimple_call_fndecl (call
);
902 /* Handle those builtin functions explicitly that do not act as
903 escape points. See tree-ssa-structalias.c:find_func_aliases
904 for the list of builtins we might need to handle here. */
905 if (callee
!= NULL_TREE
906 && DECL_BUILT_IN_CLASS (callee
) == BUILT_IN_NORMAL
)
907 switch (DECL_FUNCTION_CODE (callee
))
909 /* All the following functions clobber memory pointed to by
910 their first argument. */
911 case BUILT_IN_STRCPY
:
912 case BUILT_IN_STRNCPY
:
914 case BUILT_IN_MEMCPY
:
915 case BUILT_IN_MEMMOVE
:
916 case BUILT_IN_MEMPCPY
:
917 case BUILT_IN_STPCPY
:
918 case BUILT_IN_STPNCPY
:
919 case BUILT_IN_STRCAT
:
920 case BUILT_IN_STRNCAT
:
923 tree size
= NULL_TREE
;
924 if (gimple_call_num_args (call
) == 3)
925 size
= gimple_call_arg (call
, 2);
926 ao_ref_init_from_ptr_and_size (&dref
,
927 gimple_call_arg (call
, 1),
929 return refs_may_alias_p_1 (&dref
, ref
, false);
931 /* The following builtins do not read from memory. */
933 case BUILT_IN_MEMSET
:
935 case BUILT_IN_FREXPF
:
936 case BUILT_IN_FREXPL
:
937 case BUILT_IN_GAMMA_R
:
938 case BUILT_IN_GAMMAF_R
:
939 case BUILT_IN_GAMMAL_R
:
940 case BUILT_IN_LGAMMA_R
:
941 case BUILT_IN_LGAMMAF_R
:
942 case BUILT_IN_LGAMMAL_R
:
946 case BUILT_IN_REMQUO
:
947 case BUILT_IN_REMQUOF
:
948 case BUILT_IN_REMQUOL
:
949 case BUILT_IN_SINCOS
:
950 case BUILT_IN_SINCOSF
:
951 case BUILT_IN_SINCOSL
:
955 /* Fallthru to general call handling. */;
958 /* Check if base is a global static variable that is not read
960 if (TREE_CODE (base
) == VAR_DECL
961 && TREE_STATIC (base
)
962 && !TREE_PUBLIC (base
))
966 if (callee
!= NULL_TREE
968 = ipa_reference_get_not_read_global (cgraph_node (callee
)))
969 && bitmap_bit_p (not_read
, DECL_UID (base
)))
973 /* If the base variable is call-used or call-clobbered then
975 if (flags
& (ECF_PURE
|ECF_CONST
|ECF_LOOPING_CONST_OR_PURE
|ECF_NOVOPS
))
979 if (is_call_used (base
))
982 else if (INDIRECT_REF_P (base
)
983 && TREE_CODE (TREE_OPERAND (base
, 0)) == SSA_NAME
)
985 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (TREE_OPERAND (base
, 0));
989 if (pt_solution_includes_global (&pi
->pt
)
990 || pt_solutions_intersect (&cfun
->gimple_df
->callused
, &pi
->pt
)
991 || pt_solutions_intersect (&cfun
->gimple_df
->escaped
, &pi
->pt
))
1001 if (is_call_clobbered (base
))
1004 else if (INDIRECT_REF_P (base
)
1005 && TREE_CODE (TREE_OPERAND (base
, 0)) == SSA_NAME
)
1007 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (TREE_OPERAND (base
, 0));
1011 if (pt_solution_includes_global (&pi
->pt
)
1012 || pt_solutions_intersect (&cfun
->gimple_df
->escaped
, &pi
->pt
))
1019 /* Inspect call arguments for passed-by-value aliases. */
1021 for (i
= 0; i
< gimple_call_num_args (call
); ++i
)
1023 tree op
= gimple_call_arg (call
, i
);
1025 if (TREE_CODE (op
) == EXC_PTR_EXPR
1026 || TREE_CODE (op
) == FILTER_EXPR
)
1029 if (TREE_CODE (op
) == WITH_SIZE_EXPR
)
1030 op
= TREE_OPERAND (op
, 0);
1032 if (TREE_CODE (op
) != SSA_NAME
1033 && !is_gimple_min_invariant (op
))
1036 ao_ref_init (&r
, op
);
1037 if (refs_may_alias_p_1 (&r
, ref
, true))
1046 ref_maybe_used_by_call_p (gimple call
, tree ref
)
1050 ao_ref_init (&r
, ref
);
1051 res
= ref_maybe_used_by_call_p_1 (call
, &r
);
1053 ++alias_stats
.ref_maybe_used_by_call_p_may_alias
;
1055 ++alias_stats
.ref_maybe_used_by_call_p_no_alias
;
1060 /* If the statement STMT may use the memory reference REF return
1061 true, otherwise return false. */
1064 ref_maybe_used_by_stmt_p (gimple stmt
, tree ref
)
1066 if (is_gimple_assign (stmt
))
1070 /* All memory assign statements are single. */
1071 if (!gimple_assign_single_p (stmt
))
1074 rhs
= gimple_assign_rhs1 (stmt
);
1075 if (is_gimple_reg (rhs
)
1076 || is_gimple_min_invariant (rhs
)
1077 || gimple_assign_rhs_code (stmt
) == CONSTRUCTOR
)
1080 return refs_may_alias_p (rhs
, ref
);
1082 else if (is_gimple_call (stmt
))
1083 return ref_maybe_used_by_call_p (stmt
, ref
);
1088 /* If the call in statement CALL may clobber the memory reference REF
1089 return true, otherwise return false. */
1092 call_may_clobber_ref_p_1 (gimple call
, ao_ref
*ref
)
1097 /* If the call is pure or const it cannot clobber anything. */
1098 if (gimple_call_flags (call
)
1099 & (ECF_PURE
|ECF_CONST
|ECF_LOOPING_CONST_OR_PURE
|ECF_NOVOPS
))
1102 base
= ao_ref_base (ref
);
1106 if (TREE_CODE (base
) == SSA_NAME
1107 || CONSTANT_CLASS_P (base
))
1110 /* If the reference is based on a decl that is not aliased the call
1111 cannot possibly clobber it. */
1113 && !may_be_aliased (base
)
1114 /* But local non-readonly statics can be modified through recursion
1115 or the call may implement a threading barrier which we must
1116 treat as may-def. */
1117 && (TREE_READONLY (base
)
1118 || !is_global_var (base
)))
1121 callee
= gimple_call_fndecl (call
);
1123 /* Handle those builtin functions explicitly that do not act as
1124 escape points. See tree-ssa-structalias.c:find_func_aliases
1125 for the list of builtins we might need to handle here. */
1126 if (callee
!= NULL_TREE
1127 && DECL_BUILT_IN_CLASS (callee
) == BUILT_IN_NORMAL
)
1128 switch (DECL_FUNCTION_CODE (callee
))
1130 /* All the following functions clobber memory pointed to by
1131 their first argument. */
1132 case BUILT_IN_STRCPY
:
1133 case BUILT_IN_STRNCPY
:
1134 case BUILT_IN_BCOPY
:
1135 case BUILT_IN_MEMCPY
:
1136 case BUILT_IN_MEMMOVE
:
1137 case BUILT_IN_MEMPCPY
:
1138 case BUILT_IN_STPCPY
:
1139 case BUILT_IN_STPNCPY
:
1140 case BUILT_IN_STRCAT
:
1141 case BUILT_IN_STRNCAT
:
1142 case BUILT_IN_MEMSET
:
1145 tree size
= NULL_TREE
;
1146 if (gimple_call_num_args (call
) == 3)
1147 size
= gimple_call_arg (call
, 2);
1148 ao_ref_init_from_ptr_and_size (&dref
,
1149 gimple_call_arg (call
, 0),
1151 return refs_may_alias_p_1 (&dref
, ref
, false);
1153 /* Freeing memory kills the pointed-to memory. More importantly
1154 the call has to serve as a barrier for moving loads and stores
1158 tree ptr
= gimple_call_arg (call
, 0);
1159 return ptr_deref_may_alias_ref_p_1 (ptr
, ref
);
1161 case BUILT_IN_GAMMA_R
:
1162 case BUILT_IN_GAMMAF_R
:
1163 case BUILT_IN_GAMMAL_R
:
1164 case BUILT_IN_LGAMMA_R
:
1165 case BUILT_IN_LGAMMAF_R
:
1166 case BUILT_IN_LGAMMAL_R
:
1168 tree out
= gimple_call_arg (call
, 1);
1169 if (ptr_deref_may_alias_ref_p_1 (out
, ref
))
1171 if (flag_errno_math
)
1175 case BUILT_IN_FREXP
:
1176 case BUILT_IN_FREXPF
:
1177 case BUILT_IN_FREXPL
:
1179 case BUILT_IN_MODFF
:
1180 case BUILT_IN_MODFL
:
1182 tree out
= gimple_call_arg (call
, 1);
1183 return ptr_deref_may_alias_ref_p_1 (out
, ref
);
1185 case BUILT_IN_REMQUO
:
1186 case BUILT_IN_REMQUOF
:
1187 case BUILT_IN_REMQUOL
:
1189 tree out
= gimple_call_arg (call
, 2);
1190 if (ptr_deref_may_alias_ref_p_1 (out
, ref
))
1192 if (flag_errno_math
)
1196 case BUILT_IN_SINCOS
:
1197 case BUILT_IN_SINCOSF
:
1198 case BUILT_IN_SINCOSL
:
1200 tree sin
= gimple_call_arg (call
, 1);
1201 tree cos
= gimple_call_arg (call
, 2);
1202 return (ptr_deref_may_alias_ref_p_1 (sin
, ref
)
1203 || ptr_deref_may_alias_ref_p_1 (cos
, ref
));
1206 /* Fallthru to general call handling. */;
1209 /* Check if base is a global static variable that is not written
1211 if (callee
!= NULL_TREE
1212 && TREE_CODE (base
) == VAR_DECL
1213 && TREE_STATIC (base
)
1214 && !TREE_PUBLIC (base
))
1219 = ipa_reference_get_not_written_global (cgraph_node (callee
)))
1220 && bitmap_bit_p (not_written
, DECL_UID (base
)))
1225 return is_call_clobbered (base
);
1226 else if (INDIRECT_REF_P (base
)
1227 && TREE_CODE (TREE_OPERAND (base
, 0)) == SSA_NAME
)
1229 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (TREE_OPERAND (base
, 0));
1233 return (pt_solution_includes_global (&pi
->pt
)
1234 || pt_solutions_intersect (&cfun
->gimple_df
->escaped
, &pi
->pt
));
1240 static bool ATTRIBUTE_UNUSED
1241 call_may_clobber_ref_p (gimple call
, tree ref
)
1245 ao_ref_init (&r
, ref
);
1246 res
= call_may_clobber_ref_p_1 (call
, &r
);
1248 ++alias_stats
.call_may_clobber_ref_p_may_alias
;
1250 ++alias_stats
.call_may_clobber_ref_p_no_alias
;
1255 /* If the statement STMT may clobber the memory reference REF return true,
1256 otherwise return false. */
1259 stmt_may_clobber_ref_p_1 (gimple stmt
, ao_ref
*ref
)
1261 if (is_gimple_call (stmt
))
1263 tree lhs
= gimple_call_lhs (stmt
);
1265 && !is_gimple_reg (lhs
))
1268 ao_ref_init (&r
, lhs
);
1269 if (refs_may_alias_p_1 (ref
, &r
, true))
1273 return call_may_clobber_ref_p_1 (stmt
, ref
);
1275 else if (is_gimple_assign (stmt
))
1278 ao_ref_init (&r
, gimple_assign_lhs (stmt
));
1279 return refs_may_alias_p_1 (ref
, &r
, true);
1281 else if (gimple_code (stmt
) == GIMPLE_ASM
)
1288 stmt_may_clobber_ref_p (gimple stmt
, tree ref
)
1291 ao_ref_init (&r
, ref
);
1292 return stmt_may_clobber_ref_p_1 (stmt
, &r
);
1296 static tree
get_continuation_for_phi (gimple
, ao_ref
*, bitmap
*);
1298 /* Walk the virtual use-def chain of VUSE until hitting the virtual operand
1299 TARGET or a statement clobbering the memory reference REF in which
1300 case false is returned. The walk starts with VUSE, one argument of PHI. */
1303 maybe_skip_until (gimple phi
, tree target
, ao_ref
*ref
,
1304 tree vuse
, bitmap
*visited
)
1307 *visited
= BITMAP_ALLOC (NULL
);
1309 bitmap_set_bit (*visited
, SSA_NAME_VERSION (PHI_RESULT (phi
)));
1311 /* Walk until we hit the target. */
1312 while (vuse
!= target
)
1314 gimple def_stmt
= SSA_NAME_DEF_STMT (vuse
);
1315 /* Recurse for PHI nodes. */
1316 if (gimple_code (def_stmt
) == GIMPLE_PHI
)
1318 /* An already visited PHI node ends the walk successfully. */
1319 if (bitmap_bit_p (*visited
, SSA_NAME_VERSION (PHI_RESULT (def_stmt
))))
1321 vuse
= get_continuation_for_phi (def_stmt
, ref
, visited
);
1326 /* A clobbering statement or the end of the IL ends it failing. */
1327 else if (gimple_nop_p (def_stmt
)
1328 || stmt_may_clobber_ref_p_1 (def_stmt
, ref
))
1330 vuse
= gimple_vuse (def_stmt
);
1335 /* Starting from a PHI node for the virtual operand of the memory reference
1336 REF find a continuation virtual operand that allows to continue walking
1337 statements dominating PHI skipping only statements that cannot possibly
1338 clobber REF. Returns NULL_TREE if no suitable virtual operand can
1342 get_continuation_for_phi (gimple phi
, ao_ref
*ref
, bitmap
*visited
)
1344 unsigned nargs
= gimple_phi_num_args (phi
);
1346 /* Through a single-argument PHI we can simply look through. */
1348 return PHI_ARG_DEF (phi
, 0);
1350 /* For two arguments try to skip non-aliasing code until we hit
1351 the phi argument definition that dominates the other one. */
1354 tree arg0
= PHI_ARG_DEF (phi
, 0);
1355 tree arg1
= PHI_ARG_DEF (phi
, 1);
1356 gimple def0
= SSA_NAME_DEF_STMT (arg0
);
1357 gimple def1
= SSA_NAME_DEF_STMT (arg1
);
1361 else if (gimple_nop_p (def0
)
1362 || (!gimple_nop_p (def1
)
1363 && dominated_by_p (CDI_DOMINATORS
,
1364 gimple_bb (def1
), gimple_bb (def0
))))
1366 if (maybe_skip_until (phi
, arg0
, ref
, arg1
, visited
))
1369 else if (gimple_nop_p (def1
)
1370 || dominated_by_p (CDI_DOMINATORS
,
1371 gimple_bb (def0
), gimple_bb (def1
)))
1373 if (maybe_skip_until (phi
, arg1
, ref
, arg0
, visited
))
1381 /* Based on the memory reference REF and its virtual use VUSE call
1382 WALKER for each virtual use that is equivalent to VUSE, including VUSE
1383 itself. That is, for each virtual use for which its defining statement
1384 does not clobber REF.
1386 WALKER is called with REF, the current virtual use and DATA. If
1387 WALKER returns non-NULL the walk stops and its result is returned.
1388 At the end of a non-successful walk NULL is returned.
1390 TRANSLATE if non-NULL is called with a pointer to REF, the virtual
1391 use which definition is a statement that may clobber REF and DATA.
1392 If TRANSLATE returns (void *)-1 the walk stops and NULL is returned.
1393 If TRANSLATE returns non-NULL the walk stops and its result is returned.
1394 If TRANSLATE returns NULL the walk continues and TRANSLATE is supposed
1395 to adjust REF and *DATA to make that valid.
1397 TODO: Cache the vector of equivalent vuses per ref, vuse pair. */
1400 walk_non_aliased_vuses (ao_ref
*ref
, tree vuse
,
1401 void *(*walker
)(ao_ref
*, tree
, void *),
1402 void *(*translate
)(ao_ref
*, tree
, void *), void *data
)
1404 bitmap visited
= NULL
;
1407 timevar_push (TV_ALIAS_STMT_WALK
);
1413 /* ??? Do we want to account this to TV_ALIAS_STMT_WALK? */
1414 res
= (*walker
) (ref
, vuse
, data
);
1418 def_stmt
= SSA_NAME_DEF_STMT (vuse
);
1419 if (gimple_nop_p (def_stmt
))
1421 else if (gimple_code (def_stmt
) == GIMPLE_PHI
)
1422 vuse
= get_continuation_for_phi (def_stmt
, ref
, &visited
);
1425 if (stmt_may_clobber_ref_p_1 (def_stmt
, ref
))
1429 res
= (*translate
) (ref
, vuse
, data
);
1430 /* Failed lookup and translation. */
1431 if (res
== (void *)-1)
1436 /* Lookup succeeded. */
1437 else if (res
!= NULL
)
1439 /* Translation succeeded, continue walking. */
1441 vuse
= gimple_vuse (def_stmt
);
1447 BITMAP_FREE (visited
);
1449 timevar_pop (TV_ALIAS_STMT_WALK
);
1455 /* Based on the memory reference REF call WALKER for each vdef which
1456 defining statement may clobber REF, starting with VDEF. If REF
1457 is NULL_TREE, each defining statement is visited.
1459 WALKER is called with REF, the current vdef and DATA. If WALKER
1460 returns true the walk is stopped, otherwise it continues.
1462 At PHI nodes walk_aliased_vdefs forks into one walk for reach
1463 PHI argument (but only one walk continues on merge points), the
1464 return value is true if any of the walks was successful.
1466 The function returns the number of statements walked. */
1469 walk_aliased_vdefs_1 (ao_ref
*ref
, tree vdef
,
1470 bool (*walker
)(ao_ref
*, tree
, void *), void *data
,
1471 bitmap
*visited
, unsigned int cnt
)
1475 gimple def_stmt
= SSA_NAME_DEF_STMT (vdef
);
1478 && !bitmap_set_bit (*visited
, SSA_NAME_VERSION (vdef
)))
1481 if (gimple_nop_p (def_stmt
))
1483 else if (gimple_code (def_stmt
) == GIMPLE_PHI
)
1487 *visited
= BITMAP_ALLOC (NULL
);
1488 for (i
= 0; i
< gimple_phi_num_args (def_stmt
); ++i
)
1489 cnt
+= walk_aliased_vdefs_1 (ref
, gimple_phi_arg_def (def_stmt
, i
),
1490 walker
, data
, visited
, 0);
1494 /* ??? Do we want to account this to TV_ALIAS_STMT_WALK? */
1497 || stmt_may_clobber_ref_p_1 (def_stmt
, ref
))
1498 && (*walker
) (ref
, vdef
, data
))
1501 vdef
= gimple_vuse (def_stmt
);
1507 walk_aliased_vdefs (ao_ref
*ref
, tree vdef
,
1508 bool (*walker
)(ao_ref
*, tree
, void *), void *data
,
1511 bitmap local_visited
= NULL
;
1514 timevar_push (TV_ALIAS_STMT_WALK
);
1516 ret
= walk_aliased_vdefs_1 (ref
, vdef
, walker
, data
,
1517 visited
? visited
: &local_visited
, 0);
1519 BITMAP_FREE (local_visited
);
1521 timevar_pop (TV_ALIAS_STMT_WALK
);