1 /* Alias analysis for trees.
2 Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
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 "basic-block.h"
32 #include "langhooks.h"
35 #include "tree-pretty-print.h"
36 #include "tree-dump.h"
38 #include "tree-flow.h"
39 #include "tree-inline.h"
40 #include "tree-pass.h"
46 #include "pointer-set.h"
47 #include "alloc-pool.h"
48 #include "tree-ssa-alias.h"
50 /* Broad overview of how alias analysis on gimple works:
52 Statements clobbering or using memory are linked through the
53 virtual operand factored use-def chain. The virtual operand
54 is unique per function, its symbol is accessible via gimple_vop (cfun).
55 Virtual operands are used for efficiently walking memory statements
56 in the gimple IL and are useful for things like value-numbering as
57 a generation count for memory references.
59 SSA_NAME pointers may have associated points-to information
60 accessible via the SSA_NAME_PTR_INFO macro. Flow-insensitive
61 points-to information is (re-)computed by the TODO_rebuild_alias
62 pass manager todo. Points-to information is also used for more
63 precise tracking of call-clobbered and call-used variables and
64 related disambiguations.
66 This file contains functions for disambiguating memory references,
67 the so called alias-oracle and tools for walking of the gimple IL.
69 The main alias-oracle entry-points are
71 bool stmt_may_clobber_ref_p (gimple, tree)
73 This function queries if a statement may invalidate (parts of)
74 the memory designated by the reference tree argument.
76 bool ref_maybe_used_by_stmt_p (gimple, tree)
78 This function queries if a statement may need (parts of) the
79 memory designated by the reference tree argument.
81 There are variants of these functions that only handle the call
82 part of a statement, call_may_clobber_ref_p and ref_maybe_used_by_call_p.
83 Note that these do not disambiguate against a possible call lhs.
85 bool refs_may_alias_p (tree, tree)
87 This function tries to disambiguate two reference trees.
89 bool ptr_deref_may_alias_global_p (tree)
91 This function queries if dereferencing a pointer variable may
94 More low-level disambiguators are available and documented in
95 this file. Low-level disambiguators dealing with points-to
96 information are in tree-ssa-structalias.c. */
99 /* Query statistics for the different low-level disambiguators.
100 A high-level query may trigger multiple of them. */
103 unsigned HOST_WIDE_INT refs_may_alias_p_may_alias
;
104 unsigned HOST_WIDE_INT refs_may_alias_p_no_alias
;
105 unsigned HOST_WIDE_INT ref_maybe_used_by_call_p_may_alias
;
106 unsigned HOST_WIDE_INT ref_maybe_used_by_call_p_no_alias
;
107 unsigned HOST_WIDE_INT call_may_clobber_ref_p_may_alias
;
108 unsigned HOST_WIDE_INT call_may_clobber_ref_p_no_alias
;
112 dump_alias_stats (FILE *s
)
114 fprintf (s
, "\nAlias oracle query stats:\n");
115 fprintf (s
, " refs_may_alias_p: "
116 HOST_WIDE_INT_PRINT_DEC
" disambiguations, "
117 HOST_WIDE_INT_PRINT_DEC
" queries\n",
118 alias_stats
.refs_may_alias_p_no_alias
,
119 alias_stats
.refs_may_alias_p_no_alias
120 + alias_stats
.refs_may_alias_p_may_alias
);
121 fprintf (s
, " ref_maybe_used_by_call_p: "
122 HOST_WIDE_INT_PRINT_DEC
" disambiguations, "
123 HOST_WIDE_INT_PRINT_DEC
" queries\n",
124 alias_stats
.ref_maybe_used_by_call_p_no_alias
,
125 alias_stats
.refs_may_alias_p_no_alias
126 + alias_stats
.ref_maybe_used_by_call_p_may_alias
);
127 fprintf (s
, " call_may_clobber_ref_p: "
128 HOST_WIDE_INT_PRINT_DEC
" disambiguations, "
129 HOST_WIDE_INT_PRINT_DEC
" queries\n",
130 alias_stats
.call_may_clobber_ref_p_no_alias
,
131 alias_stats
.call_may_clobber_ref_p_no_alias
132 + alias_stats
.call_may_clobber_ref_p_may_alias
);
136 /* Return true, if dereferencing PTR may alias with a global variable. */
139 ptr_deref_may_alias_global_p (tree ptr
)
141 struct ptr_info_def
*pi
;
143 /* If we end up with a pointer constant here that may point
145 if (TREE_CODE (ptr
) != SSA_NAME
)
148 pi
= SSA_NAME_PTR_INFO (ptr
);
150 /* If we do not have points-to information for this variable,
155 /* ??? This does not use TBAA to prune globals ptr may not access. */
156 return pt_solution_includes_global (&pi
->pt
);
159 /* Return true if dereferencing PTR may alias DECL.
160 The caller is responsible for applying TBAA to see if PTR
161 may access DECL at all. */
164 ptr_deref_may_alias_decl_p (tree ptr
, tree decl
)
166 struct ptr_info_def
*pi
;
168 /* Conversions are irrelevant for points-to information and
169 data-dependence analysis can feed us those. */
172 /* Anything we do not explicilty handle aliases. */
173 if ((TREE_CODE (ptr
) != SSA_NAME
174 && TREE_CODE (ptr
) != ADDR_EXPR
175 && TREE_CODE (ptr
) != POINTER_PLUS_EXPR
)
176 || !POINTER_TYPE_P (TREE_TYPE (ptr
))
177 || (TREE_CODE (decl
) != VAR_DECL
178 && TREE_CODE (decl
) != PARM_DECL
179 && TREE_CODE (decl
) != RESULT_DECL
))
182 /* Disregard pointer offsetting. */
183 if (TREE_CODE (ptr
) == POINTER_PLUS_EXPR
)
187 ptr
= TREE_OPERAND (ptr
, 0);
189 while (TREE_CODE (ptr
) == POINTER_PLUS_EXPR
);
190 return ptr_deref_may_alias_decl_p (ptr
, decl
);
193 /* ADDR_EXPR pointers either just offset another pointer or directly
194 specify the pointed-to set. */
195 if (TREE_CODE (ptr
) == ADDR_EXPR
)
197 tree base
= get_base_address (TREE_OPERAND (ptr
, 0));
199 && (TREE_CODE (base
) == MEM_REF
200 || TREE_CODE (base
) == TARGET_MEM_REF
))
201 ptr
= TREE_OPERAND (base
, 0);
206 && CONSTANT_CLASS_P (base
))
212 /* Non-aliased variables can not be pointed to. */
213 if (!may_be_aliased (decl
))
216 /* If we do not have useful points-to information for this pointer
217 we cannot disambiguate anything else. */
218 pi
= SSA_NAME_PTR_INFO (ptr
);
222 /* If the decl can be used as a restrict tag and we have a restrict
223 pointer and that pointers points-to set doesn't contain this decl
224 then they can't alias. */
225 if (DECL_RESTRICTED_P (decl
)
226 && TYPE_RESTRICT (TREE_TYPE (ptr
))
227 && pi
->pt
.vars_contains_restrict
)
228 return bitmap_bit_p (pi
->pt
.vars
, DECL_PT_UID (decl
));
230 return pt_solution_includes (&pi
->pt
, decl
);
233 /* Return true if dereferenced PTR1 and PTR2 may alias.
234 The caller is responsible for applying TBAA to see if accesses
235 through PTR1 and PTR2 may conflict at all. */
238 ptr_derefs_may_alias_p (tree ptr1
, tree ptr2
)
240 struct ptr_info_def
*pi1
, *pi2
;
242 /* Conversions are irrelevant for points-to information and
243 data-dependence analysis can feed us those. */
247 /* Anything we do not explicilty handle aliases. */
248 if ((TREE_CODE (ptr1
) != SSA_NAME
249 && TREE_CODE (ptr1
) != ADDR_EXPR
250 && TREE_CODE (ptr1
) != POINTER_PLUS_EXPR
)
251 || (TREE_CODE (ptr2
) != SSA_NAME
252 && TREE_CODE (ptr2
) != ADDR_EXPR
253 && TREE_CODE (ptr2
) != POINTER_PLUS_EXPR
)
254 || !POINTER_TYPE_P (TREE_TYPE (ptr1
))
255 || !POINTER_TYPE_P (TREE_TYPE (ptr2
)))
258 /* Disregard pointer offsetting. */
259 if (TREE_CODE (ptr1
) == POINTER_PLUS_EXPR
)
263 ptr1
= TREE_OPERAND (ptr1
, 0);
265 while (TREE_CODE (ptr1
) == POINTER_PLUS_EXPR
);
266 return ptr_derefs_may_alias_p (ptr1
, ptr2
);
268 if (TREE_CODE (ptr2
) == POINTER_PLUS_EXPR
)
272 ptr2
= TREE_OPERAND (ptr2
, 0);
274 while (TREE_CODE (ptr2
) == POINTER_PLUS_EXPR
);
275 return ptr_derefs_may_alias_p (ptr1
, ptr2
);
278 /* ADDR_EXPR pointers either just offset another pointer or directly
279 specify the pointed-to set. */
280 if (TREE_CODE (ptr1
) == ADDR_EXPR
)
282 tree base
= get_base_address (TREE_OPERAND (ptr1
, 0));
284 && (TREE_CODE (base
) == MEM_REF
285 || TREE_CODE (base
) == TARGET_MEM_REF
))
286 ptr1
= TREE_OPERAND (base
, 0);
289 return ptr_deref_may_alias_decl_p (ptr2
, base
);
293 if (TREE_CODE (ptr2
) == ADDR_EXPR
)
295 tree base
= get_base_address (TREE_OPERAND (ptr2
, 0));
297 && (TREE_CODE (base
) == MEM_REF
298 || TREE_CODE (base
) == TARGET_MEM_REF
))
299 ptr2
= TREE_OPERAND (base
, 0);
302 return ptr_deref_may_alias_decl_p (ptr1
, base
);
307 /* We may end up with two empty points-to solutions for two same pointers.
308 In this case we still want to say both pointers alias, so shortcut
313 /* If we do not have useful points-to information for either pointer
314 we cannot disambiguate anything else. */
315 pi1
= SSA_NAME_PTR_INFO (ptr1
);
316 pi2
= SSA_NAME_PTR_INFO (ptr2
);
320 /* If both pointers are restrict-qualified try to disambiguate
321 with restrict information. */
322 if (TYPE_RESTRICT (TREE_TYPE (ptr1
))
323 && TYPE_RESTRICT (TREE_TYPE (ptr2
))
324 && !pt_solutions_same_restrict_base (&pi1
->pt
, &pi2
->pt
))
327 /* ??? This does not use TBAA to prune decls from the intersection
328 that not both pointers may access. */
329 return pt_solutions_intersect (&pi1
->pt
, &pi2
->pt
);
332 /* Return true if dereferencing PTR may alias *REF.
333 The caller is responsible for applying TBAA to see if PTR
334 may access *REF at all. */
337 ptr_deref_may_alias_ref_p_1 (tree ptr
, ao_ref
*ref
)
339 tree base
= ao_ref_base (ref
);
341 if (TREE_CODE (base
) == MEM_REF
342 || TREE_CODE (base
) == TARGET_MEM_REF
)
343 return ptr_derefs_may_alias_p (ptr
, TREE_OPERAND (base
, 0));
344 else if (DECL_P (base
))
345 return ptr_deref_may_alias_decl_p (ptr
, base
);
351 /* Dump alias information on FILE. */
354 dump_alias_info (FILE *file
)
358 = lang_hooks
.decl_printable_name (current_function_decl
, 2);
359 referenced_var_iterator rvi
;
362 fprintf (file
, "\n\nAlias information for %s\n\n", funcname
);
364 fprintf (file
, "Aliased symbols\n\n");
366 FOR_EACH_REFERENCED_VAR (cfun
, var
, rvi
)
368 if (may_be_aliased (var
))
369 dump_variable (file
, var
);
372 fprintf (file
, "\nCall clobber information\n");
374 fprintf (file
, "\nESCAPED");
375 dump_points_to_solution (file
, &cfun
->gimple_df
->escaped
);
377 fprintf (file
, "\n\nFlow-insensitive points-to information\n\n");
379 for (i
= 1; i
< num_ssa_names
; i
++)
381 tree ptr
= ssa_name (i
);
382 struct ptr_info_def
*pi
;
385 || SSA_NAME_IN_FREE_LIST (ptr
))
388 pi
= SSA_NAME_PTR_INFO (ptr
);
390 dump_points_to_info_for (file
, ptr
);
393 fprintf (file
, "\n");
397 /* Dump alias information on stderr. */
400 debug_alias_info (void)
402 dump_alias_info (stderr
);
406 /* Dump the points-to set *PT into FILE. */
409 dump_points_to_solution (FILE *file
, struct pt_solution
*pt
)
412 fprintf (file
, ", points-to anything");
415 fprintf (file
, ", points-to non-local");
418 fprintf (file
, ", points-to escaped");
421 fprintf (file
, ", points-to unit escaped");
424 fprintf (file
, ", points-to NULL");
428 fprintf (file
, ", points-to vars: ");
429 dump_decl_set (file
, pt
->vars
);
430 if (pt
->vars_contains_global
)
431 fprintf (file
, " (includes global vars)");
432 if (pt
->vars_contains_restrict
)
433 fprintf (file
, " (includes restrict tags)");
437 /* Dump points-to information for SSA_NAME PTR into FILE. */
440 dump_points_to_info_for (FILE *file
, tree ptr
)
442 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (ptr
);
444 print_generic_expr (file
, ptr
, dump_flags
);
447 dump_points_to_solution (file
, &pi
->pt
);
449 fprintf (file
, ", points-to anything");
451 fprintf (file
, "\n");
455 /* Dump points-to information for VAR into stderr. */
458 debug_points_to_info_for (tree var
)
460 dump_points_to_info_for (stderr
, var
);
464 /* Initializes the alias-oracle reference representation *R from REF. */
467 ao_ref_init (ao_ref
*r
, tree ref
)
474 r
->ref_alias_set
= -1;
475 r
->base_alias_set
= -1;
478 /* Returns the base object of the memory reference *REF. */
481 ao_ref_base (ao_ref
*ref
)
485 ref
->base
= get_ref_base_and_extent (ref
->ref
, &ref
->offset
, &ref
->size
,
490 /* Returns the base object alias set of the memory reference *REF. */
492 static alias_set_type
493 ao_ref_base_alias_set (ao_ref
*ref
)
496 if (ref
->base_alias_set
!= -1)
497 return ref
->base_alias_set
;
501 while (handled_component_p (base_ref
))
502 base_ref
= TREE_OPERAND (base_ref
, 0);
503 ref
->base_alias_set
= get_alias_set (base_ref
);
504 return ref
->base_alias_set
;
507 /* Returns the reference alias set of the memory reference *REF. */
510 ao_ref_alias_set (ao_ref
*ref
)
512 if (ref
->ref_alias_set
!= -1)
513 return ref
->ref_alias_set
;
514 ref
->ref_alias_set
= get_alias_set (ref
->ref
);
515 return ref
->ref_alias_set
;
518 /* Init an alias-oracle reference representation from a gimple pointer
519 PTR and a gimple size SIZE in bytes. If SIZE is NULL_TREE the the
520 size is assumed to be unknown. The access is assumed to be only
521 to or after of the pointer target, not before it. */
524 ao_ref_init_from_ptr_and_size (ao_ref
*ref
, tree ptr
, tree size
)
526 HOST_WIDE_INT t1
, t2
;
527 ref
->ref
= NULL_TREE
;
528 if (TREE_CODE (ptr
) == ADDR_EXPR
)
529 ref
->base
= get_ref_base_and_extent (TREE_OPERAND (ptr
, 0),
530 &ref
->offset
, &t1
, &t2
);
533 ref
->base
= build2 (MEM_REF
, char_type_node
,
534 ptr
, null_pointer_node
);
538 && host_integerp (size
, 0)
539 && TREE_INT_CST_LOW (size
) * 8 / 8 == TREE_INT_CST_LOW (size
))
540 ref
->max_size
= ref
->size
= TREE_INT_CST_LOW (size
) * 8;
542 ref
->max_size
= ref
->size
= -1;
543 ref
->ref_alias_set
= 0;
544 ref
->base_alias_set
= 0;
547 /* Return 1 if TYPE1 and TYPE2 are to be considered equivalent for the
548 purpose of TBAA. Return 0 if they are distinct and -1 if we cannot
552 same_type_for_tbaa (tree type1
, tree type2
)
554 type1
= TYPE_MAIN_VARIANT (type1
);
555 type2
= TYPE_MAIN_VARIANT (type2
);
557 /* If we would have to do structural comparison bail out. */
558 if (TYPE_STRUCTURAL_EQUALITY_P (type1
)
559 || TYPE_STRUCTURAL_EQUALITY_P (type2
))
562 /* Compare the canonical types. */
563 if (TYPE_CANONICAL (type1
) == TYPE_CANONICAL (type2
))
566 /* ??? Array types are not properly unified in all cases as we have
567 spurious changes in the index types for example. Removing this
568 causes all sorts of problems with the Fortran frontend. */
569 if (TREE_CODE (type1
) == ARRAY_TYPE
570 && TREE_CODE (type2
) == ARRAY_TYPE
)
573 /* ??? In Ada, an lvalue of an unconstrained type can be used to access an
574 object of one of its constrained subtypes, e.g. when a function with an
575 unconstrained parameter passed by reference is called on an object and
576 inlined. But, even in the case of a fixed size, type and subtypes are
577 not equivalent enough as to share the same TYPE_CANONICAL, since this
578 would mean that conversions between them are useless, whereas they are
579 not (e.g. type and subtypes can have different modes). So, in the end,
580 they are only guaranteed to have the same alias set. */
581 if (get_alias_set (type1
) == get_alias_set (type2
))
584 /* The types are known to be not equal. */
588 /* Determine if the two component references REF1 and REF2 which are
589 based on access types TYPE1 and TYPE2 and of which at least one is based
590 on an indirect reference may alias. REF2 is the only one that can
591 be a decl in which case REF2_IS_DECL is true.
592 REF1_ALIAS_SET, BASE1_ALIAS_SET, REF2_ALIAS_SET and BASE2_ALIAS_SET
593 are the respective alias sets. */
596 aliasing_component_refs_p (tree ref1
,
597 alias_set_type ref1_alias_set
,
598 alias_set_type base1_alias_set
,
599 HOST_WIDE_INT offset1
, HOST_WIDE_INT max_size1
,
601 alias_set_type ref2_alias_set
,
602 alias_set_type base2_alias_set
,
603 HOST_WIDE_INT offset2
, HOST_WIDE_INT max_size2
,
606 /* If one reference is a component references through pointers try to find a
607 common base and apply offset based disambiguation. This handles
609 struct A { int i; int j; } *q;
610 struct B { struct A a; int k; } *p;
611 disambiguating q->i and p->a.j. */
617 /* Choose bases and base types to search for. */
619 while (handled_component_p (base1
))
620 base1
= TREE_OPERAND (base1
, 0);
621 type1
= TREE_TYPE (base1
);
623 while (handled_component_p (base2
))
624 base2
= TREE_OPERAND (base2
, 0);
625 type2
= TREE_TYPE (base2
);
627 /* Now search for the type1 in the access path of ref2. This
628 would be a common base for doing offset based disambiguation on. */
630 while (handled_component_p (*refp
)
631 && same_type_for_tbaa (TREE_TYPE (*refp
), type1
) == 0)
632 refp
= &TREE_OPERAND (*refp
, 0);
633 same_p
= same_type_for_tbaa (TREE_TYPE (*refp
), type1
);
634 /* If we couldn't compare types we have to bail out. */
637 else if (same_p
== 1)
639 HOST_WIDE_INT offadj
, sztmp
, msztmp
;
640 get_ref_base_and_extent (*refp
, &offadj
, &sztmp
, &msztmp
);
642 get_ref_base_and_extent (base1
, &offadj
, &sztmp
, &msztmp
);
644 return ranges_overlap_p (offset1
, max_size1
, offset2
, max_size2
);
646 /* If we didn't find a common base, try the other way around. */
648 while (handled_component_p (*refp
)
649 && same_type_for_tbaa (TREE_TYPE (*refp
), type2
) == 0)
650 refp
= &TREE_OPERAND (*refp
, 0);
651 same_p
= same_type_for_tbaa (TREE_TYPE (*refp
), type2
);
652 /* If we couldn't compare types we have to bail out. */
655 else if (same_p
== 1)
657 HOST_WIDE_INT offadj
, sztmp
, msztmp
;
658 get_ref_base_and_extent (*refp
, &offadj
, &sztmp
, &msztmp
);
660 get_ref_base_and_extent (base2
, &offadj
, &sztmp
, &msztmp
);
662 return ranges_overlap_p (offset1
, max_size1
, offset2
, max_size2
);
665 /* If we have two type access paths B1.path1 and B2.path2 they may
666 only alias if either B1 is in B2.path2 or B2 is in B1.path1.
667 But we can still have a path that goes B1.path1...B2.path2 with
668 a part that we do not see. So we can only disambiguate now
669 if there is no B2 in the tail of path1 and no B1 on the
671 if (base1_alias_set
== ref2_alias_set
672 || alias_set_subset_of (base1_alias_set
, ref2_alias_set
))
674 /* If this is ptr vs. decl then we know there is no ptr ... decl path. */
676 return (base2_alias_set
== ref1_alias_set
677 || alias_set_subset_of (base2_alias_set
, ref1_alias_set
));
681 /* Return true if two memory references based on the variables BASE1
682 and BASE2 constrained to [OFFSET1, OFFSET1 + MAX_SIZE1) and
683 [OFFSET2, OFFSET2 + MAX_SIZE2) may alias. */
686 decl_refs_may_alias_p (tree base1
,
687 HOST_WIDE_INT offset1
, HOST_WIDE_INT max_size1
,
689 HOST_WIDE_INT offset2
, HOST_WIDE_INT max_size2
)
691 gcc_checking_assert (DECL_P (base1
) && DECL_P (base2
));
693 /* If both references are based on different variables, they cannot alias. */
697 /* If both references are based on the same variable, they cannot alias if
698 the accesses do not overlap. */
699 return ranges_overlap_p (offset1
, max_size1
, offset2
, max_size2
);
702 /* Return true if an indirect reference based on *PTR1 constrained
703 to [OFFSET1, OFFSET1 + MAX_SIZE1) may alias a variable based on BASE2
704 constrained to [OFFSET2, OFFSET2 + MAX_SIZE2). *PTR1 and BASE2 have
705 the alias sets BASE1_ALIAS_SET and BASE2_ALIAS_SET which can be -1
706 in which case they are computed on-demand. REF1 and REF2
707 if non-NULL are the complete memory reference trees. */
710 indirect_ref_may_alias_decl_p (tree ref1 ATTRIBUTE_UNUSED
, tree base1
,
711 HOST_WIDE_INT offset1
,
712 HOST_WIDE_INT max_size1 ATTRIBUTE_UNUSED
,
713 alias_set_type ref1_alias_set
,
714 alias_set_type base1_alias_set
,
715 tree ref2 ATTRIBUTE_UNUSED
, tree base2
,
716 HOST_WIDE_INT offset2
, HOST_WIDE_INT max_size2
,
717 alias_set_type ref2_alias_set
,
718 alias_set_type base2_alias_set
, bool tbaa_p
)
721 tree ptrtype1
, dbase2
;
722 HOST_WIDE_INT offset1p
= offset1
, offset2p
= offset2
;
723 HOST_WIDE_INT doffset1
, doffset2
;
726 gcc_checking_assert ((TREE_CODE (base1
) == MEM_REF
727 || TREE_CODE (base1
) == TARGET_MEM_REF
)
730 ptr1
= TREE_OPERAND (base1
, 0);
732 /* The offset embedded in MEM_REFs can be negative. Bias them
733 so that the resulting offset adjustment is positive. */
734 moff
= mem_ref_offset (base1
);
735 moff
= double_int_lshift (moff
,
737 ? 3 : exact_log2 (BITS_PER_UNIT
),
738 HOST_BITS_PER_DOUBLE_INT
, true);
739 if (double_int_negative_p (moff
))
740 offset2p
+= double_int_neg (moff
).low
;
742 offset1p
+= moff
.low
;
744 /* If only one reference is based on a variable, they cannot alias if
745 the pointer access is beyond the extent of the variable access.
746 (the pointer base cannot validly point to an offset less than zero
748 ??? IVOPTs creates bases that do not honor this restriction,
749 so do not apply this optimization for TARGET_MEM_REFs. */
750 if (TREE_CODE (base1
) != TARGET_MEM_REF
751 && !ranges_overlap_p (MAX (0, offset1p
), -1, offset2p
, max_size2
))
753 /* They also cannot alias if the pointer may not point to the decl. */
754 if (!ptr_deref_may_alias_decl_p (ptr1
, base2
))
757 /* Disambiguations that rely on strict aliasing rules follow. */
758 if (!flag_strict_aliasing
|| !tbaa_p
)
761 ptrtype1
= TREE_TYPE (TREE_OPERAND (base1
, 1));
763 /* If the alias set for a pointer access is zero all bets are off. */
764 if (base1_alias_set
== -1)
765 base1_alias_set
= get_deref_alias_set (ptrtype1
);
766 if (base1_alias_set
== 0)
768 if (base2_alias_set
== -1)
769 base2_alias_set
= get_alias_set (base2
);
771 /* When we are trying to disambiguate an access with a pointer dereference
772 as base versus one with a decl as base we can use both the size
773 of the decl and its dynamic type for extra disambiguation.
774 ??? We do not know anything about the dynamic type of the decl
775 other than that its alias-set contains base2_alias_set as a subset
776 which does not help us here. */
777 /* As we know nothing useful about the dynamic type of the decl just
778 use the usual conflict check rather than a subset test.
779 ??? We could introduce -fvery-strict-aliasing when the language
780 does not allow decls to have a dynamic type that differs from their
781 static type. Then we can check
782 !alias_set_subset_of (base1_alias_set, base2_alias_set) instead. */
783 if (base1_alias_set
!= base2_alias_set
784 && !alias_sets_conflict_p (base1_alias_set
, base2_alias_set
))
786 /* If the size of the access relevant for TBAA through the pointer
787 is bigger than the size of the decl we can't possibly access the
788 decl via that pointer. */
789 if (DECL_SIZE (base2
) && COMPLETE_TYPE_P (TREE_TYPE (ptrtype1
))
790 && TREE_CODE (DECL_SIZE (base2
)) == INTEGER_CST
791 && TREE_CODE (TYPE_SIZE (TREE_TYPE (ptrtype1
))) == INTEGER_CST
792 /* ??? This in turn may run afoul when a decl of type T which is
793 a member of union type U is accessed through a pointer to
794 type U and sizeof T is smaller than sizeof U. */
795 && TREE_CODE (TREE_TYPE (ptrtype1
)) != UNION_TYPE
796 && TREE_CODE (TREE_TYPE (ptrtype1
)) != QUAL_UNION_TYPE
797 && tree_int_cst_lt (DECL_SIZE (base2
), TYPE_SIZE (TREE_TYPE (ptrtype1
))))
803 /* If the decl is accessed via a MEM_REF, reconstruct the base
804 we can use for TBAA and an appropriately adjusted offset. */
806 while (handled_component_p (dbase2
))
807 dbase2
= TREE_OPERAND (dbase2
, 0);
810 if (TREE_CODE (dbase2
) == MEM_REF
811 || TREE_CODE (dbase2
) == TARGET_MEM_REF
)
813 double_int moff
= mem_ref_offset (dbase2
);
814 moff
= double_int_lshift (moff
,
816 ? 3 : exact_log2 (BITS_PER_UNIT
),
817 HOST_BITS_PER_DOUBLE_INT
, true);
818 if (double_int_negative_p (moff
))
819 doffset1
-= double_int_neg (moff
).low
;
821 doffset2
-= moff
.low
;
824 /* If either reference is view-converted, give up now. */
825 if (same_type_for_tbaa (TREE_TYPE (base1
), TREE_TYPE (ptrtype1
)) != 1
826 || same_type_for_tbaa (TREE_TYPE (dbase2
),
827 TREE_TYPE (reference_alias_ptr_type (dbase2
))) != 1)
830 /* If both references are through the same type, they do not alias
831 if the accesses do not overlap. This does extra disambiguation
832 for mixed/pointer accesses but requires strict aliasing.
833 For MEM_REFs we require that the component-ref offset we computed
834 is relative to the start of the type which we ensure by
835 comparing rvalue and access type and disregarding the constant
837 if ((TREE_CODE (base1
) != TARGET_MEM_REF
838 || (!TMR_INDEX (base1
) && !TMR_INDEX2 (base1
)))
839 && same_type_for_tbaa (TREE_TYPE (base1
), TREE_TYPE (dbase2
)) == 1)
840 return ranges_overlap_p (doffset1
, max_size1
, doffset2
, max_size2
);
842 /* Do access-path based disambiguation. */
844 && (handled_component_p (ref1
) || handled_component_p (ref2
)))
845 return aliasing_component_refs_p (ref1
,
846 ref1_alias_set
, base1_alias_set
,
849 ref2_alias_set
, base2_alias_set
,
850 offset2
, max_size2
, true);
855 /* Return true if two indirect references based on *PTR1
856 and *PTR2 constrained to [OFFSET1, OFFSET1 + MAX_SIZE1) and
857 [OFFSET2, OFFSET2 + MAX_SIZE2) may alias. *PTR1 and *PTR2 have
858 the alias sets BASE1_ALIAS_SET and BASE2_ALIAS_SET which can be -1
859 in which case they are computed on-demand. REF1 and REF2
860 if non-NULL are the complete memory reference trees. */
863 indirect_refs_may_alias_p (tree ref1 ATTRIBUTE_UNUSED
, tree base1
,
864 HOST_WIDE_INT offset1
, HOST_WIDE_INT max_size1
,
865 alias_set_type ref1_alias_set
,
866 alias_set_type base1_alias_set
,
867 tree ref2 ATTRIBUTE_UNUSED
, tree base2
,
868 HOST_WIDE_INT offset2
, HOST_WIDE_INT max_size2
,
869 alias_set_type ref2_alias_set
,
870 alias_set_type base2_alias_set
, bool tbaa_p
)
874 tree ptrtype1
, ptrtype2
;
876 gcc_checking_assert ((TREE_CODE (base1
) == MEM_REF
877 || TREE_CODE (base1
) == TARGET_MEM_REF
)
878 && (TREE_CODE (base2
) == MEM_REF
879 || TREE_CODE (base2
) == TARGET_MEM_REF
));
881 ptr1
= TREE_OPERAND (base1
, 0);
882 ptr2
= TREE_OPERAND (base2
, 0);
884 /* If both bases are based on pointers they cannot alias if they may not
885 point to the same memory object or if they point to the same object
886 and the accesses do not overlap. */
887 if ((!cfun
|| gimple_in_ssa_p (cfun
))
888 && operand_equal_p (ptr1
, ptr2
, 0)
889 && (((TREE_CODE (base1
) != TARGET_MEM_REF
890 || (!TMR_INDEX (base1
) && !TMR_INDEX2 (base1
)))
891 && (TREE_CODE (base2
) != TARGET_MEM_REF
892 || (!TMR_INDEX (base2
) && !TMR_INDEX2 (base2
))))
893 || (TREE_CODE (base1
) == TARGET_MEM_REF
894 && TREE_CODE (base2
) == TARGET_MEM_REF
895 && (TMR_STEP (base1
) == TMR_STEP (base2
)
896 || (TMR_STEP (base1
) && TMR_STEP (base2
)
897 && operand_equal_p (TMR_STEP (base1
),
898 TMR_STEP (base2
), 0)))
899 && (TMR_INDEX (base1
) == TMR_INDEX (base2
)
900 || (TMR_INDEX (base1
) && TMR_INDEX (base2
)
901 && operand_equal_p (TMR_INDEX (base1
),
902 TMR_INDEX (base2
), 0)))
903 && (TMR_INDEX2 (base1
) == TMR_INDEX2 (base2
)
904 || (TMR_INDEX2 (base1
) && TMR_INDEX2 (base2
)
905 && operand_equal_p (TMR_INDEX2 (base1
),
906 TMR_INDEX2 (base2
), 0))))))
909 /* The offset embedded in MEM_REFs can be negative. Bias them
910 so that the resulting offset adjustment is positive. */
911 moff
= mem_ref_offset (base1
);
912 moff
= double_int_lshift (moff
,
914 ? 3 : exact_log2 (BITS_PER_UNIT
),
915 HOST_BITS_PER_DOUBLE_INT
, true);
916 if (double_int_negative_p (moff
))
917 offset2
+= double_int_neg (moff
).low
;
920 moff
= mem_ref_offset (base2
);
921 moff
= double_int_lshift (moff
,
923 ? 3 : exact_log2 (BITS_PER_UNIT
),
924 HOST_BITS_PER_DOUBLE_INT
, true);
925 if (double_int_negative_p (moff
))
926 offset1
+= double_int_neg (moff
).low
;
929 return ranges_overlap_p (offset1
, max_size1
, offset2
, max_size2
);
931 if (!ptr_derefs_may_alias_p (ptr1
, ptr2
))
934 /* Disambiguations that rely on strict aliasing rules follow. */
935 if (!flag_strict_aliasing
|| !tbaa_p
)
938 ptrtype1
= TREE_TYPE (TREE_OPERAND (base1
, 1));
939 ptrtype2
= TREE_TYPE (TREE_OPERAND (base2
, 1));
941 /* If the alias set for a pointer access is zero all bets are off. */
942 if (base1_alias_set
== -1)
943 base1_alias_set
= get_deref_alias_set (ptrtype1
);
944 if (base1_alias_set
== 0)
946 if (base2_alias_set
== -1)
947 base2_alias_set
= get_deref_alias_set (ptrtype2
);
948 if (base2_alias_set
== 0)
951 /* If both references are through the same type, they do not alias
952 if the accesses do not overlap. This does extra disambiguation
953 for mixed/pointer accesses but requires strict aliasing. */
954 if ((TREE_CODE (base1
) != TARGET_MEM_REF
955 || (!TMR_INDEX (base1
) && !TMR_INDEX2 (base1
)))
956 && (TREE_CODE (base2
) != TARGET_MEM_REF
957 || (!TMR_INDEX (base2
) && !TMR_INDEX2 (base2
)))
958 && same_type_for_tbaa (TREE_TYPE (base1
), TREE_TYPE (ptrtype1
)) == 1
959 && same_type_for_tbaa (TREE_TYPE (base2
), TREE_TYPE (ptrtype2
)) == 1
960 && same_type_for_tbaa (TREE_TYPE (ptrtype1
),
961 TREE_TYPE (ptrtype2
)) == 1)
962 return ranges_overlap_p (offset1
, max_size1
, offset2
, max_size2
);
964 /* Do type-based disambiguation. */
965 if (base1_alias_set
!= base2_alias_set
966 && !alias_sets_conflict_p (base1_alias_set
, base2_alias_set
))
969 /* Do access-path based disambiguation. */
971 && (handled_component_p (ref1
) || handled_component_p (ref2
))
972 && same_type_for_tbaa (TREE_TYPE (base1
), TREE_TYPE (ptrtype1
)) == 1
973 && same_type_for_tbaa (TREE_TYPE (base2
), TREE_TYPE (ptrtype2
)) == 1)
974 return aliasing_component_refs_p (ref1
,
975 ref1_alias_set
, base1_alias_set
,
978 ref2_alias_set
, base2_alias_set
,
979 offset2
, max_size2
, false);
984 /* Return true, if the two memory references REF1 and REF2 may alias. */
987 refs_may_alias_p_1 (ao_ref
*ref1
, ao_ref
*ref2
, bool tbaa_p
)
990 HOST_WIDE_INT offset1
= 0, offset2
= 0;
991 HOST_WIDE_INT max_size1
= -1, max_size2
= -1;
992 bool var1_p
, var2_p
, ind1_p
, ind2_p
;
994 gcc_checking_assert ((!ref1
->ref
995 || TREE_CODE (ref1
->ref
) == SSA_NAME
996 || DECL_P (ref1
->ref
)
997 || TREE_CODE (ref1
->ref
) == STRING_CST
998 || handled_component_p (ref1
->ref
)
999 || TREE_CODE (ref1
->ref
) == MEM_REF
1000 || TREE_CODE (ref1
->ref
) == TARGET_MEM_REF
)
1002 || TREE_CODE (ref2
->ref
) == SSA_NAME
1003 || DECL_P (ref2
->ref
)
1004 || TREE_CODE (ref2
->ref
) == STRING_CST
1005 || handled_component_p (ref2
->ref
)
1006 || TREE_CODE (ref2
->ref
) == MEM_REF
1007 || TREE_CODE (ref2
->ref
) == TARGET_MEM_REF
));
1009 /* Decompose the references into their base objects and the access. */
1010 base1
= ao_ref_base (ref1
);
1011 offset1
= ref1
->offset
;
1012 max_size1
= ref1
->max_size
;
1013 base2
= ao_ref_base (ref2
);
1014 offset2
= ref2
->offset
;
1015 max_size2
= ref2
->max_size
;
1017 /* We can end up with registers or constants as bases for example from
1018 *D.1663_44 = VIEW_CONVERT_EXPR<struct DB_LSN>(__tmp$B0F64_59);
1019 which is seen as a struct copy. */
1020 if (TREE_CODE (base1
) == SSA_NAME
1021 || TREE_CODE (base1
) == CONST_DECL
1022 || TREE_CODE (base1
) == CONSTRUCTOR
1023 || TREE_CODE (base1
) == ADDR_EXPR
1024 || CONSTANT_CLASS_P (base1
)
1025 || TREE_CODE (base2
) == SSA_NAME
1026 || TREE_CODE (base2
) == CONST_DECL
1027 || TREE_CODE (base2
) == CONSTRUCTOR
1028 || TREE_CODE (base2
) == ADDR_EXPR
1029 || CONSTANT_CLASS_P (base2
))
1032 /* We can end up refering to code via function and label decls.
1033 As we likely do not properly track code aliases conservatively
1035 if (TREE_CODE (base1
) == FUNCTION_DECL
1036 || TREE_CODE (base1
) == LABEL_DECL
1037 || TREE_CODE (base2
) == FUNCTION_DECL
1038 || TREE_CODE (base2
) == LABEL_DECL
)
1041 /* Defer to simple offset based disambiguation if we have
1042 references based on two decls. Do this before defering to
1043 TBAA to handle must-alias cases in conformance with the
1044 GCC extension of allowing type-punning through unions. */
1045 var1_p
= DECL_P (base1
);
1046 var2_p
= DECL_P (base2
);
1047 if (var1_p
&& var2_p
)
1048 return decl_refs_may_alias_p (base1
, offset1
, max_size1
,
1049 base2
, offset2
, max_size2
);
1051 ind1_p
= (TREE_CODE (base1
) == MEM_REF
1052 || TREE_CODE (base1
) == TARGET_MEM_REF
);
1053 ind2_p
= (TREE_CODE (base2
) == MEM_REF
1054 || TREE_CODE (base2
) == TARGET_MEM_REF
);
1056 /* Canonicalize the pointer-vs-decl case. */
1057 if (ind1_p
&& var2_p
)
1062 tmp1
= offset1
; offset1
= offset2
; offset2
= tmp1
;
1063 tmp1
= max_size1
; max_size1
= max_size2
; max_size2
= tmp1
;
1064 tmp2
= base1
; base1
= base2
; base2
= tmp2
;
1065 tmp3
= ref1
; ref1
= ref2
; ref2
= tmp3
;
1072 /* First defer to TBAA if possible. */
1074 && flag_strict_aliasing
1075 && !alias_sets_conflict_p (ao_ref_alias_set (ref1
),
1076 ao_ref_alias_set (ref2
)))
1079 /* Dispatch to the pointer-vs-decl or pointer-vs-pointer disambiguators. */
1080 if (var1_p
&& ind2_p
)
1081 return indirect_ref_may_alias_decl_p (ref2
->ref
, base2
,
1083 ao_ref_alias_set (ref2
), -1,
1086 ao_ref_alias_set (ref1
),
1087 ao_ref_base_alias_set (ref1
),
1089 else if (ind1_p
&& ind2_p
)
1090 return indirect_refs_may_alias_p (ref1
->ref
, base1
,
1092 ao_ref_alias_set (ref1
), -1,
1095 ao_ref_alias_set (ref2
), -1,
1098 /* We really do not want to end up here, but returning true is safe. */
1099 #ifdef ENABLE_CHECKING
1107 refs_may_alias_p (tree ref1
, tree ref2
)
1111 ao_ref_init (&r1
, ref1
);
1112 ao_ref_init (&r2
, ref2
);
1113 res
= refs_may_alias_p_1 (&r1
, &r2
, true);
1115 ++alias_stats
.refs_may_alias_p_may_alias
;
1117 ++alias_stats
.refs_may_alias_p_no_alias
;
1121 /* Returns true if there is a anti-dependence for the STORE that
1122 executes after the LOAD. */
1125 refs_anti_dependent_p (tree load
, tree store
)
1128 ao_ref_init (&r1
, load
);
1129 ao_ref_init (&r2
, store
);
1130 return refs_may_alias_p_1 (&r1
, &r2
, false);
1133 /* Returns true if there is a output dependence for the stores
1134 STORE1 and STORE2. */
1137 refs_output_dependent_p (tree store1
, tree store2
)
1140 ao_ref_init (&r1
, store1
);
1141 ao_ref_init (&r2
, store2
);
1142 return refs_may_alias_p_1 (&r1
, &r2
, false);
1145 /* If the call CALL may use the memory reference REF return true,
1146 otherwise return false. */
1149 ref_maybe_used_by_call_p_1 (gimple call
, ao_ref
*ref
)
1153 int flags
= gimple_call_flags (call
);
1155 /* Const functions without a static chain do not implicitly use memory. */
1156 if (!gimple_call_chain (call
)
1157 && (flags
& (ECF_CONST
|ECF_NOVOPS
)))
1160 base
= ao_ref_base (ref
);
1164 /* If the reference is based on a decl that is not aliased the call
1165 cannot possibly use it. */
1167 && !may_be_aliased (base
)
1168 /* But local statics can be used through recursion. */
1169 && !is_global_var (base
))
1172 callee
= gimple_call_fndecl (call
);
1174 /* Handle those builtin functions explicitly that do not act as
1175 escape points. See tree-ssa-structalias.c:find_func_aliases
1176 for the list of builtins we might need to handle here. */
1177 if (callee
!= NULL_TREE
1178 && DECL_BUILT_IN_CLASS (callee
) == BUILT_IN_NORMAL
)
1179 switch (DECL_FUNCTION_CODE (callee
))
1181 /* All the following functions read memory pointed to by
1182 their second argument. strcat/strncat additionally
1183 reads memory pointed to by the first argument. */
1184 case BUILT_IN_STRCAT
:
1185 case BUILT_IN_STRNCAT
:
1188 ao_ref_init_from_ptr_and_size (&dref
,
1189 gimple_call_arg (call
, 0),
1191 if (refs_may_alias_p_1 (&dref
, ref
, false))
1195 case BUILT_IN_STRCPY
:
1196 case BUILT_IN_STRNCPY
:
1197 case BUILT_IN_MEMCPY
:
1198 case BUILT_IN_MEMMOVE
:
1199 case BUILT_IN_MEMPCPY
:
1200 case BUILT_IN_STPCPY
:
1201 case BUILT_IN_STPNCPY
:
1204 tree size
= NULL_TREE
;
1205 if (gimple_call_num_args (call
) == 3)
1206 size
= gimple_call_arg (call
, 2);
1207 ao_ref_init_from_ptr_and_size (&dref
,
1208 gimple_call_arg (call
, 1),
1210 return refs_may_alias_p_1 (&dref
, ref
, false);
1212 case BUILT_IN_STRCAT_CHK
:
1213 case BUILT_IN_STRNCAT_CHK
:
1216 ao_ref_init_from_ptr_and_size (&dref
,
1217 gimple_call_arg (call
, 0),
1219 if (refs_may_alias_p_1 (&dref
, ref
, false))
1223 case BUILT_IN_STRCPY_CHK
:
1224 case BUILT_IN_STRNCPY_CHK
:
1225 case BUILT_IN_MEMCPY_CHK
:
1226 case BUILT_IN_MEMMOVE_CHK
:
1227 case BUILT_IN_MEMPCPY_CHK
:
1228 case BUILT_IN_STPCPY_CHK
:
1231 tree size
= NULL_TREE
;
1232 if (gimple_call_num_args (call
) == 4)
1233 size
= gimple_call_arg (call
, 2);
1234 ao_ref_init_from_ptr_and_size (&dref
,
1235 gimple_call_arg (call
, 1),
1237 return refs_may_alias_p_1 (&dref
, ref
, false);
1239 case BUILT_IN_BCOPY
:
1242 tree size
= gimple_call_arg (call
, 2);
1243 ao_ref_init_from_ptr_and_size (&dref
,
1244 gimple_call_arg (call
, 0),
1246 return refs_may_alias_p_1 (&dref
, ref
, false);
1248 /* These read memory pointed to by the first argument. */
1249 case BUILT_IN_STRDUP
:
1250 case BUILT_IN_STRNDUP
:
1253 tree size
= NULL_TREE
;
1254 if (gimple_call_num_args (call
) == 2)
1255 size
= gimple_call_arg (call
, 1);
1256 ao_ref_init_from_ptr_and_size (&dref
,
1257 gimple_call_arg (call
, 0),
1259 return refs_may_alias_p_1 (&dref
, ref
, false);
1261 /* The following builtins do not read from memory. */
1263 case BUILT_IN_MALLOC
:
1264 case BUILT_IN_CALLOC
:
1265 case BUILT_IN_ALLOCA
:
1266 case BUILT_IN_STACK_SAVE
:
1267 case BUILT_IN_STACK_RESTORE
:
1268 case BUILT_IN_MEMSET
:
1269 case BUILT_IN_MEMSET_CHK
:
1270 case BUILT_IN_FREXP
:
1271 case BUILT_IN_FREXPF
:
1272 case BUILT_IN_FREXPL
:
1273 case BUILT_IN_GAMMA_R
:
1274 case BUILT_IN_GAMMAF_R
:
1275 case BUILT_IN_GAMMAL_R
:
1276 case BUILT_IN_LGAMMA_R
:
1277 case BUILT_IN_LGAMMAF_R
:
1278 case BUILT_IN_LGAMMAL_R
:
1280 case BUILT_IN_MODFF
:
1281 case BUILT_IN_MODFL
:
1282 case BUILT_IN_REMQUO
:
1283 case BUILT_IN_REMQUOF
:
1284 case BUILT_IN_REMQUOL
:
1285 case BUILT_IN_SINCOS
:
1286 case BUILT_IN_SINCOSF
:
1287 case BUILT_IN_SINCOSL
:
1288 case BUILT_IN_ASSUME_ALIGNED
:
1289 case BUILT_IN_VA_END
:
1291 /* __sync_* builtins and some OpenMP builtins act as threading
1293 #undef DEF_SYNC_BUILTIN
1294 #define DEF_SYNC_BUILTIN(ENUM, NAME, TYPE, ATTRS) case ENUM:
1295 #include "sync-builtins.def"
1296 #undef DEF_SYNC_BUILTIN
1297 case BUILT_IN_GOMP_ATOMIC_START
:
1298 case BUILT_IN_GOMP_ATOMIC_END
:
1299 case BUILT_IN_GOMP_BARRIER
:
1300 case BUILT_IN_GOMP_TASKWAIT
:
1301 case BUILT_IN_GOMP_CRITICAL_START
:
1302 case BUILT_IN_GOMP_CRITICAL_END
:
1303 case BUILT_IN_GOMP_CRITICAL_NAME_START
:
1304 case BUILT_IN_GOMP_CRITICAL_NAME_END
:
1305 case BUILT_IN_GOMP_LOOP_END
:
1306 case BUILT_IN_GOMP_ORDERED_START
:
1307 case BUILT_IN_GOMP_ORDERED_END
:
1308 case BUILT_IN_GOMP_PARALLEL_END
:
1309 case BUILT_IN_GOMP_SECTIONS_END
:
1310 case BUILT_IN_GOMP_SINGLE_COPY_START
:
1311 case BUILT_IN_GOMP_SINGLE_COPY_END
:
1315 /* Fallthru to general call handling. */;
1318 /* Check if base is a global static variable that is not read
1320 if (callee
!= NULL_TREE
1321 && TREE_CODE (base
) == VAR_DECL
1322 && TREE_STATIC (base
))
1324 struct cgraph_node
*node
= cgraph_get_node (callee
);
1327 /* FIXME: Callee can be an OMP builtin that does not have a call graph
1328 node yet. We should enforce that there are nodes for all decls in the
1329 IL and remove this check instead. */
1331 && (not_read
= ipa_reference_get_not_read_global (node
))
1332 && bitmap_bit_p (not_read
, DECL_UID (base
)))
1336 /* Check if the base variable is call-used. */
1339 if (pt_solution_includes (gimple_call_use_set (call
), base
))
1342 else if ((TREE_CODE (base
) == MEM_REF
1343 || TREE_CODE (base
) == TARGET_MEM_REF
)
1344 && TREE_CODE (TREE_OPERAND (base
, 0)) == SSA_NAME
)
1346 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (TREE_OPERAND (base
, 0));
1350 if (pt_solutions_intersect (gimple_call_use_set (call
), &pi
->pt
))
1356 /* Inspect call arguments for passed-by-value aliases. */
1358 for (i
= 0; i
< gimple_call_num_args (call
); ++i
)
1360 tree op
= gimple_call_arg (call
, i
);
1361 int flags
= gimple_call_arg_flags (call
, i
);
1363 if (flags
& EAF_UNUSED
)
1366 if (TREE_CODE (op
) == WITH_SIZE_EXPR
)
1367 op
= TREE_OPERAND (op
, 0);
1369 if (TREE_CODE (op
) != SSA_NAME
1370 && !is_gimple_min_invariant (op
))
1373 ao_ref_init (&r
, op
);
1374 if (refs_may_alias_p_1 (&r
, ref
, true))
1383 ref_maybe_used_by_call_p (gimple call
, tree ref
)
1387 ao_ref_init (&r
, ref
);
1388 res
= ref_maybe_used_by_call_p_1 (call
, &r
);
1390 ++alias_stats
.ref_maybe_used_by_call_p_may_alias
;
1392 ++alias_stats
.ref_maybe_used_by_call_p_no_alias
;
1397 /* If the statement STMT may use the memory reference REF return
1398 true, otherwise return false. */
1401 ref_maybe_used_by_stmt_p (gimple stmt
, tree ref
)
1403 if (is_gimple_assign (stmt
))
1407 /* All memory assign statements are single. */
1408 if (!gimple_assign_single_p (stmt
))
1411 rhs
= gimple_assign_rhs1 (stmt
);
1412 if (is_gimple_reg (rhs
)
1413 || is_gimple_min_invariant (rhs
)
1414 || gimple_assign_rhs_code (stmt
) == CONSTRUCTOR
)
1417 return refs_may_alias_p (rhs
, ref
);
1419 else if (is_gimple_call (stmt
))
1420 return ref_maybe_used_by_call_p (stmt
, ref
);
1421 else if (gimple_code (stmt
) == GIMPLE_RETURN
)
1423 tree retval
= gimple_return_retval (stmt
);
1426 && TREE_CODE (retval
) != SSA_NAME
1427 && !is_gimple_min_invariant (retval
)
1428 && refs_may_alias_p (retval
, ref
))
1430 /* If ref escapes the function then the return acts as a use. */
1431 base
= get_base_address (ref
);
1434 else if (DECL_P (base
))
1435 return is_global_var (base
);
1436 else if (TREE_CODE (base
) == MEM_REF
1437 || TREE_CODE (base
) == TARGET_MEM_REF
)
1438 return ptr_deref_may_alias_global_p (TREE_OPERAND (base
, 0));
1445 /* If the call in statement CALL may clobber the memory reference REF
1446 return true, otherwise return false. */
1449 call_may_clobber_ref_p_1 (gimple call
, ao_ref
*ref
)
1454 /* If the call is pure or const it cannot clobber anything. */
1455 if (gimple_call_flags (call
)
1456 & (ECF_PURE
|ECF_CONST
|ECF_LOOPING_CONST_OR_PURE
|ECF_NOVOPS
))
1459 base
= ao_ref_base (ref
);
1463 if (TREE_CODE (base
) == SSA_NAME
1464 || CONSTANT_CLASS_P (base
))
1467 /* If the reference is based on a decl that is not aliased the call
1468 cannot possibly clobber it. */
1470 && !may_be_aliased (base
)
1471 /* But local non-readonly statics can be modified through recursion
1472 or the call may implement a threading barrier which we must
1473 treat as may-def. */
1474 && (TREE_READONLY (base
)
1475 || !is_global_var (base
)))
1478 callee
= gimple_call_fndecl (call
);
1480 /* Handle those builtin functions explicitly that do not act as
1481 escape points. See tree-ssa-structalias.c:find_func_aliases
1482 for the list of builtins we might need to handle here. */
1483 if (callee
!= NULL_TREE
1484 && DECL_BUILT_IN_CLASS (callee
) == BUILT_IN_NORMAL
)
1485 switch (DECL_FUNCTION_CODE (callee
))
1487 /* All the following functions clobber memory pointed to by
1488 their first argument. */
1489 case BUILT_IN_STRCPY
:
1490 case BUILT_IN_STRNCPY
:
1491 case BUILT_IN_MEMCPY
:
1492 case BUILT_IN_MEMMOVE
:
1493 case BUILT_IN_MEMPCPY
:
1494 case BUILT_IN_STPCPY
:
1495 case BUILT_IN_STPNCPY
:
1496 case BUILT_IN_STRCAT
:
1497 case BUILT_IN_STRNCAT
:
1498 case BUILT_IN_MEMSET
:
1501 tree size
= NULL_TREE
;
1502 /* Don't pass in size for strncat, as the maximum size
1503 is strlen (dest) + n + 1 instead of n, resp.
1504 n + 1 at dest + strlen (dest), but strlen (dest) isn't
1506 if (gimple_call_num_args (call
) == 3
1507 && DECL_FUNCTION_CODE (callee
) != BUILT_IN_STRNCAT
)
1508 size
= gimple_call_arg (call
, 2);
1509 ao_ref_init_from_ptr_and_size (&dref
,
1510 gimple_call_arg (call
, 0),
1512 return refs_may_alias_p_1 (&dref
, ref
, false);
1514 case BUILT_IN_STRCPY_CHK
:
1515 case BUILT_IN_STRNCPY_CHK
:
1516 case BUILT_IN_MEMCPY_CHK
:
1517 case BUILT_IN_MEMMOVE_CHK
:
1518 case BUILT_IN_MEMPCPY_CHK
:
1519 case BUILT_IN_STPCPY_CHK
:
1520 case BUILT_IN_STRCAT_CHK
:
1521 case BUILT_IN_STRNCAT_CHK
:
1522 case BUILT_IN_MEMSET_CHK
:
1525 tree size
= NULL_TREE
;
1526 /* Don't pass in size for __strncat_chk, as the maximum size
1527 is strlen (dest) + n + 1 instead of n, resp.
1528 n + 1 at dest + strlen (dest), but strlen (dest) isn't
1530 if (gimple_call_num_args (call
) == 4
1531 && DECL_FUNCTION_CODE (callee
) != BUILT_IN_STRNCAT_CHK
)
1532 size
= gimple_call_arg (call
, 2);
1533 ao_ref_init_from_ptr_and_size (&dref
,
1534 gimple_call_arg (call
, 0),
1536 return refs_may_alias_p_1 (&dref
, ref
, false);
1538 case BUILT_IN_BCOPY
:
1541 tree size
= gimple_call_arg (call
, 2);
1542 ao_ref_init_from_ptr_and_size (&dref
,
1543 gimple_call_arg (call
, 1),
1545 return refs_may_alias_p_1 (&dref
, ref
, false);
1547 /* Allocating memory does not have any side-effects apart from
1548 being the definition point for the pointer. */
1549 case BUILT_IN_MALLOC
:
1550 case BUILT_IN_CALLOC
:
1551 case BUILT_IN_STRDUP
:
1552 case BUILT_IN_STRNDUP
:
1553 /* Unix98 specifies that errno is set on allocation failure. */
1555 && targetm
.ref_may_alias_errno (ref
))
1558 case BUILT_IN_STACK_SAVE
:
1559 case BUILT_IN_ALLOCA
:
1560 case BUILT_IN_ASSUME_ALIGNED
:
1562 /* Freeing memory kills the pointed-to memory. More importantly
1563 the call has to serve as a barrier for moving loads and stores
1566 case BUILT_IN_VA_END
:
1568 tree ptr
= gimple_call_arg (call
, 0);
1569 return ptr_deref_may_alias_ref_p_1 (ptr
, ref
);
1571 case BUILT_IN_GAMMA_R
:
1572 case BUILT_IN_GAMMAF_R
:
1573 case BUILT_IN_GAMMAL_R
:
1574 case BUILT_IN_LGAMMA_R
:
1575 case BUILT_IN_LGAMMAF_R
:
1576 case BUILT_IN_LGAMMAL_R
:
1578 tree out
= gimple_call_arg (call
, 1);
1579 if (ptr_deref_may_alias_ref_p_1 (out
, ref
))
1581 if (flag_errno_math
)
1585 case BUILT_IN_FREXP
:
1586 case BUILT_IN_FREXPF
:
1587 case BUILT_IN_FREXPL
:
1589 case BUILT_IN_MODFF
:
1590 case BUILT_IN_MODFL
:
1592 tree out
= gimple_call_arg (call
, 1);
1593 return ptr_deref_may_alias_ref_p_1 (out
, ref
);
1595 case BUILT_IN_REMQUO
:
1596 case BUILT_IN_REMQUOF
:
1597 case BUILT_IN_REMQUOL
:
1599 tree out
= gimple_call_arg (call
, 2);
1600 if (ptr_deref_may_alias_ref_p_1 (out
, ref
))
1602 if (flag_errno_math
)
1606 case BUILT_IN_SINCOS
:
1607 case BUILT_IN_SINCOSF
:
1608 case BUILT_IN_SINCOSL
:
1610 tree sin
= gimple_call_arg (call
, 1);
1611 tree cos
= gimple_call_arg (call
, 2);
1612 return (ptr_deref_may_alias_ref_p_1 (sin
, ref
)
1613 || ptr_deref_may_alias_ref_p_1 (cos
, ref
));
1615 /* __sync_* builtins and some OpenMP builtins act as threading
1617 #undef DEF_SYNC_BUILTIN
1618 #define DEF_SYNC_BUILTIN(ENUM, NAME, TYPE, ATTRS) case ENUM:
1619 #include "sync-builtins.def"
1620 #undef DEF_SYNC_BUILTIN
1621 case BUILT_IN_GOMP_ATOMIC_START
:
1622 case BUILT_IN_GOMP_ATOMIC_END
:
1623 case BUILT_IN_GOMP_BARRIER
:
1624 case BUILT_IN_GOMP_TASKWAIT
:
1625 case BUILT_IN_GOMP_CRITICAL_START
:
1626 case BUILT_IN_GOMP_CRITICAL_END
:
1627 case BUILT_IN_GOMP_CRITICAL_NAME_START
:
1628 case BUILT_IN_GOMP_CRITICAL_NAME_END
:
1629 case BUILT_IN_GOMP_LOOP_END
:
1630 case BUILT_IN_GOMP_ORDERED_START
:
1631 case BUILT_IN_GOMP_ORDERED_END
:
1632 case BUILT_IN_GOMP_PARALLEL_END
:
1633 case BUILT_IN_GOMP_SECTIONS_END
:
1634 case BUILT_IN_GOMP_SINGLE_COPY_START
:
1635 case BUILT_IN_GOMP_SINGLE_COPY_END
:
1638 /* Fallthru to general call handling. */;
1641 /* Check if base is a global static variable that is not written
1643 if (callee
!= NULL_TREE
1644 && TREE_CODE (base
) == VAR_DECL
1645 && TREE_STATIC (base
))
1647 struct cgraph_node
*node
= cgraph_get_node (callee
);
1651 && (not_written
= ipa_reference_get_not_written_global (node
))
1652 && bitmap_bit_p (not_written
, DECL_UID (base
)))
1656 /* Check if the base variable is call-clobbered. */
1658 return pt_solution_includes (gimple_call_clobber_set (call
), base
);
1659 else if ((TREE_CODE (base
) == MEM_REF
1660 || TREE_CODE (base
) == TARGET_MEM_REF
)
1661 && TREE_CODE (TREE_OPERAND (base
, 0)) == SSA_NAME
)
1663 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (TREE_OPERAND (base
, 0));
1667 return pt_solutions_intersect (gimple_call_clobber_set (call
), &pi
->pt
);
1673 /* If the call in statement CALL may clobber the memory reference REF
1674 return true, otherwise return false. */
1677 call_may_clobber_ref_p (gimple call
, tree ref
)
1681 ao_ref_init (&r
, ref
);
1682 res
= call_may_clobber_ref_p_1 (call
, &r
);
1684 ++alias_stats
.call_may_clobber_ref_p_may_alias
;
1686 ++alias_stats
.call_may_clobber_ref_p_no_alias
;
1691 /* If the statement STMT may clobber the memory reference REF return true,
1692 otherwise return false. */
1695 stmt_may_clobber_ref_p_1 (gimple stmt
, ao_ref
*ref
)
1697 if (is_gimple_call (stmt
))
1699 tree lhs
= gimple_call_lhs (stmt
);
1701 && TREE_CODE (lhs
) != SSA_NAME
)
1704 ao_ref_init (&r
, lhs
);
1705 if (refs_may_alias_p_1 (ref
, &r
, true))
1709 return call_may_clobber_ref_p_1 (stmt
, ref
);
1711 else if (gimple_assign_single_p (stmt
))
1713 tree lhs
= gimple_assign_lhs (stmt
);
1714 if (TREE_CODE (lhs
) != SSA_NAME
)
1717 ao_ref_init (&r
, lhs
);
1718 return refs_may_alias_p_1 (ref
, &r
, true);
1721 else if (gimple_code (stmt
) == GIMPLE_ASM
)
1728 stmt_may_clobber_ref_p (gimple stmt
, tree ref
)
1731 ao_ref_init (&r
, ref
);
1732 return stmt_may_clobber_ref_p_1 (stmt
, &r
);
1735 /* If STMT kills the memory reference REF return true, otherwise
1739 stmt_kills_ref_p_1 (gimple stmt
, ao_ref
*ref
)
1741 /* For a must-alias check we need to be able to constrain
1742 the access properly. */
1744 if (ref
->max_size
== -1)
1747 if (gimple_has_lhs (stmt
)
1748 && TREE_CODE (gimple_get_lhs (stmt
)) != SSA_NAME
1749 /* The assignment is not necessarily carried out if it can throw
1750 and we can catch it in the current function where we could inspect
1752 ??? We only need to care about the RHS throwing. For aggregate
1753 assignments or similar calls and non-call exceptions the LHS
1754 might throw as well. */
1755 && !stmt_can_throw_internal (stmt
))
1757 tree base
, lhs
= gimple_get_lhs (stmt
);
1758 HOST_WIDE_INT size
, offset
, max_size
;
1759 base
= get_ref_base_and_extent (lhs
, &offset
, &size
, &max_size
);
1760 /* We can get MEM[symbol: sZ, index: D.8862_1] here,
1761 so base == ref->base does not always hold. */
1762 if (base
== ref
->base
)
1764 /* For a must-alias check we need to be able to constrain
1765 the access properly. */
1766 if (size
!= -1 && size
== max_size
)
1768 if (offset
<= ref
->offset
1769 && offset
+ size
>= ref
->offset
+ ref
->max_size
)
1775 if (is_gimple_call (stmt
))
1777 tree callee
= gimple_call_fndecl (stmt
);
1778 if (callee
!= NULL_TREE
1779 && DECL_BUILT_IN_CLASS (callee
) == BUILT_IN_NORMAL
)
1780 switch (DECL_FUNCTION_CODE (callee
))
1782 case BUILT_IN_MEMCPY
:
1783 case BUILT_IN_MEMPCPY
:
1784 case BUILT_IN_MEMMOVE
:
1785 case BUILT_IN_MEMSET
:
1786 case BUILT_IN_MEMCPY_CHK
:
1787 case BUILT_IN_MEMPCPY_CHK
:
1788 case BUILT_IN_MEMMOVE_CHK
:
1789 case BUILT_IN_MEMSET_CHK
:
1791 tree dest
= gimple_call_arg (stmt
, 0);
1792 tree len
= gimple_call_arg (stmt
, 2);
1793 tree base
= NULL_TREE
;
1794 HOST_WIDE_INT offset
= 0;
1795 if (!host_integerp (len
, 0))
1797 if (TREE_CODE (dest
) == ADDR_EXPR
)
1798 base
= get_addr_base_and_unit_offset (TREE_OPERAND (dest
, 0),
1800 else if (TREE_CODE (dest
) == SSA_NAME
)
1803 && base
== ao_ref_base (ref
))
1805 HOST_WIDE_INT size
= TREE_INT_CST_LOW (len
);
1806 if (offset
<= ref
->offset
/ BITS_PER_UNIT
1808 >= ((ref
->offset
+ ref
->max_size
+ BITS_PER_UNIT
- 1)
1815 case BUILT_IN_VA_END
:
1817 tree ptr
= gimple_call_arg (stmt
, 0);
1818 if (TREE_CODE (ptr
) == ADDR_EXPR
)
1820 tree base
= ao_ref_base (ref
);
1821 if (TREE_OPERAND (ptr
, 0) == base
)
1834 stmt_kills_ref_p (gimple stmt
, tree ref
)
1837 ao_ref_init (&r
, ref
);
1838 return stmt_kills_ref_p_1 (stmt
, &r
);
1842 /* Walk the virtual use-def chain of VUSE until hitting the virtual operand
1843 TARGET or a statement clobbering the memory reference REF in which
1844 case false is returned. The walk starts with VUSE, one argument of PHI. */
1847 maybe_skip_until (gimple phi
, tree target
, ao_ref
*ref
,
1848 tree vuse
, bitmap
*visited
)
1851 *visited
= BITMAP_ALLOC (NULL
);
1853 bitmap_set_bit (*visited
, SSA_NAME_VERSION (PHI_RESULT (phi
)));
1855 /* Walk until we hit the target. */
1856 while (vuse
!= target
)
1858 gimple def_stmt
= SSA_NAME_DEF_STMT (vuse
);
1859 /* Recurse for PHI nodes. */
1860 if (gimple_code (def_stmt
) == GIMPLE_PHI
)
1862 /* An already visited PHI node ends the walk successfully. */
1863 if (bitmap_bit_p (*visited
, SSA_NAME_VERSION (PHI_RESULT (def_stmt
))))
1865 vuse
= get_continuation_for_phi (def_stmt
, ref
, visited
);
1870 /* A clobbering statement or the end of the IL ends it failing. */
1871 else if (gimple_nop_p (def_stmt
)
1872 || stmt_may_clobber_ref_p_1 (def_stmt
, ref
))
1874 vuse
= gimple_vuse (def_stmt
);
1879 /* Starting from a PHI node for the virtual operand of the memory reference
1880 REF find a continuation virtual operand that allows to continue walking
1881 statements dominating PHI skipping only statements that cannot possibly
1882 clobber REF. Returns NULL_TREE if no suitable virtual operand can
1886 get_continuation_for_phi (gimple phi
, ao_ref
*ref
, bitmap
*visited
)
1888 unsigned nargs
= gimple_phi_num_args (phi
);
1890 /* Through a single-argument PHI we can simply look through. */
1892 return PHI_ARG_DEF (phi
, 0);
1894 /* For two arguments try to skip non-aliasing code until we hit
1895 the phi argument definition that dominates the other one. */
1898 tree arg0
= PHI_ARG_DEF (phi
, 0);
1899 tree arg1
= PHI_ARG_DEF (phi
, 1);
1900 gimple def0
= SSA_NAME_DEF_STMT (arg0
);
1901 gimple def1
= SSA_NAME_DEF_STMT (arg1
);
1906 else if (gimple_nop_p (def0
)
1907 || (!gimple_nop_p (def1
)
1908 && dominated_by_p (CDI_DOMINATORS
,
1909 gimple_bb (def1
), gimple_bb (def0
))))
1911 if (maybe_skip_until (phi
, arg0
, ref
, arg1
, visited
))
1914 else if (gimple_nop_p (def1
)
1915 || dominated_by_p (CDI_DOMINATORS
,
1916 gimple_bb (def0
), gimple_bb (def1
)))
1918 if (maybe_skip_until (phi
, arg1
, ref
, arg0
, visited
))
1921 /* Special case of a diamond:
1923 goto (cond) ? L1 : L2
1924 L1: store1 = ... #MEM_2 = vuse(MEM_1)
1926 L2: store2 = ... #MEM_3 = vuse(MEM_1)
1927 L3: MEM_4 = PHI<MEM_2, MEM_3>
1928 We were called with the PHI at L3, MEM_2 and MEM_3 don't
1929 dominate each other, but still we can easily skip this PHI node
1930 if we recognize that the vuse MEM operand is the same for both,
1931 and that we can skip both statements (they don't clobber us).
1932 This is still linear. Don't use maybe_skip_until, that might
1933 potentially be slow. */
1934 else if ((common_vuse
= gimple_vuse (def0
))
1935 && common_vuse
== gimple_vuse (def1
))
1937 if (!stmt_may_clobber_ref_p_1 (def0
, ref
)
1938 && !stmt_may_clobber_ref_p_1 (def1
, ref
))
1946 /* Based on the memory reference REF and its virtual use VUSE call
1947 WALKER for each virtual use that is equivalent to VUSE, including VUSE
1948 itself. That is, for each virtual use for which its defining statement
1949 does not clobber REF.
1951 WALKER is called with REF, the current virtual use and DATA. If
1952 WALKER returns non-NULL the walk stops and its result is returned.
1953 At the end of a non-successful walk NULL is returned.
1955 TRANSLATE if non-NULL is called with a pointer to REF, the virtual
1956 use which definition is a statement that may clobber REF and DATA.
1957 If TRANSLATE returns (void *)-1 the walk stops and NULL is returned.
1958 If TRANSLATE returns non-NULL the walk stops and its result is returned.
1959 If TRANSLATE returns NULL the walk continues and TRANSLATE is supposed
1960 to adjust REF and *DATA to make that valid.
1962 TODO: Cache the vector of equivalent vuses per ref, vuse pair. */
1965 walk_non_aliased_vuses (ao_ref
*ref
, tree vuse
,
1966 void *(*walker
)(ao_ref
*, tree
, void *),
1967 void *(*translate
)(ao_ref
*, tree
, void *), void *data
)
1969 bitmap visited
= NULL
;
1972 timevar_push (TV_ALIAS_STMT_WALK
);
1978 /* ??? Do we want to account this to TV_ALIAS_STMT_WALK? */
1979 res
= (*walker
) (ref
, vuse
, data
);
1983 def_stmt
= SSA_NAME_DEF_STMT (vuse
);
1984 if (gimple_nop_p (def_stmt
))
1986 else if (gimple_code (def_stmt
) == GIMPLE_PHI
)
1987 vuse
= get_continuation_for_phi (def_stmt
, ref
, &visited
);
1990 if (stmt_may_clobber_ref_p_1 (def_stmt
, ref
))
1994 res
= (*translate
) (ref
, vuse
, data
);
1995 /* Failed lookup and translation. */
1996 if (res
== (void *)-1)
2001 /* Lookup succeeded. */
2002 else if (res
!= NULL
)
2004 /* Translation succeeded, continue walking. */
2006 vuse
= gimple_vuse (def_stmt
);
2012 BITMAP_FREE (visited
);
2014 timevar_pop (TV_ALIAS_STMT_WALK
);
2020 /* Based on the memory reference REF call WALKER for each vdef which
2021 defining statement may clobber REF, starting with VDEF. If REF
2022 is NULL_TREE, each defining statement is visited.
2024 WALKER is called with REF, the current vdef and DATA. If WALKER
2025 returns true the walk is stopped, otherwise it continues.
2027 At PHI nodes walk_aliased_vdefs forks into one walk for reach
2028 PHI argument (but only one walk continues on merge points), the
2029 return value is true if any of the walks was successful.
2031 The function returns the number of statements walked. */
2034 walk_aliased_vdefs_1 (ao_ref
*ref
, tree vdef
,
2035 bool (*walker
)(ao_ref
*, tree
, void *), void *data
,
2036 bitmap
*visited
, unsigned int cnt
)
2040 gimple def_stmt
= SSA_NAME_DEF_STMT (vdef
);
2043 && !bitmap_set_bit (*visited
, SSA_NAME_VERSION (vdef
)))
2046 if (gimple_nop_p (def_stmt
))
2048 else if (gimple_code (def_stmt
) == GIMPLE_PHI
)
2052 *visited
= BITMAP_ALLOC (NULL
);
2053 for (i
= 0; i
< gimple_phi_num_args (def_stmt
); ++i
)
2054 cnt
+= walk_aliased_vdefs_1 (ref
, gimple_phi_arg_def (def_stmt
, i
),
2055 walker
, data
, visited
, 0);
2059 /* ??? Do we want to account this to TV_ALIAS_STMT_WALK? */
2062 || stmt_may_clobber_ref_p_1 (def_stmt
, ref
))
2063 && (*walker
) (ref
, vdef
, data
))
2066 vdef
= gimple_vuse (def_stmt
);
2072 walk_aliased_vdefs (ao_ref
*ref
, tree vdef
,
2073 bool (*walker
)(ao_ref
*, tree
, void *), void *data
,
2076 bitmap local_visited
= NULL
;
2079 timevar_push (TV_ALIAS_STMT_WALK
);
2081 ret
= walk_aliased_vdefs_1 (ref
, vdef
, walker
, data
,
2082 visited
? visited
: &local_visited
, 0);
2084 BITMAP_FREE (local_visited
);
2086 timevar_pop (TV_ALIAS_STMT_WALK
);