1 /* Alias analysis for trees.
2 Copyright (C) 2004-2015 Free Software Foundation, Inc.
3 Contributed by Diego Novillo <dnovillo@redhat.com>
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3, or (at your option)
12 GCC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
23 #include "coretypes.h"
29 #include "timevar.h" /* for TV_ALIAS_STMT_WALK */
32 #include "tree-pretty-print.h"
34 #include "fold-const.h"
36 #include "langhooks.h"
40 #include "ipa-reference.h"
42 /* Broad overview of how alias analysis on gimple works:
44 Statements clobbering or using memory are linked through the
45 virtual operand factored use-def chain. The virtual operand
46 is unique per function, its symbol is accessible via gimple_vop (cfun).
47 Virtual operands are used for efficiently walking memory statements
48 in the gimple IL and are useful for things like value-numbering as
49 a generation count for memory references.
51 SSA_NAME pointers may have associated points-to information
52 accessible via the SSA_NAME_PTR_INFO macro. Flow-insensitive
53 points-to information is (re-)computed by the TODO_rebuild_alias
54 pass manager todo. Points-to information is also used for more
55 precise tracking of call-clobbered and call-used variables and
56 related disambiguations.
58 This file contains functions for disambiguating memory references,
59 the so called alias-oracle and tools for walking of the gimple IL.
61 The main alias-oracle entry-points are
63 bool stmt_may_clobber_ref_p (gimple *, tree)
65 This function queries if a statement may invalidate (parts of)
66 the memory designated by the reference tree argument.
68 bool ref_maybe_used_by_stmt_p (gimple *, tree)
70 This function queries if a statement may need (parts of) the
71 memory designated by the reference tree argument.
73 There are variants of these functions that only handle the call
74 part of a statement, call_may_clobber_ref_p and ref_maybe_used_by_call_p.
75 Note that these do not disambiguate against a possible call lhs.
77 bool refs_may_alias_p (tree, tree)
79 This function tries to disambiguate two reference trees.
81 bool ptr_deref_may_alias_global_p (tree)
83 This function queries if dereferencing a pointer variable may
86 More low-level disambiguators are available and documented in
87 this file. Low-level disambiguators dealing with points-to
88 information are in tree-ssa-structalias.c. */
91 /* Query statistics for the different low-level disambiguators.
92 A high-level query may trigger multiple of them. */
95 unsigned HOST_WIDE_INT refs_may_alias_p_may_alias
;
96 unsigned HOST_WIDE_INT refs_may_alias_p_no_alias
;
97 unsigned HOST_WIDE_INT ref_maybe_used_by_call_p_may_alias
;
98 unsigned HOST_WIDE_INT ref_maybe_used_by_call_p_no_alias
;
99 unsigned HOST_WIDE_INT call_may_clobber_ref_p_may_alias
;
100 unsigned HOST_WIDE_INT call_may_clobber_ref_p_no_alias
;
104 dump_alias_stats (FILE *s
)
106 fprintf (s
, "\nAlias oracle query stats:\n");
107 fprintf (s
, " refs_may_alias_p: "
108 HOST_WIDE_INT_PRINT_DEC
" disambiguations, "
109 HOST_WIDE_INT_PRINT_DEC
" queries\n",
110 alias_stats
.refs_may_alias_p_no_alias
,
111 alias_stats
.refs_may_alias_p_no_alias
112 + alias_stats
.refs_may_alias_p_may_alias
);
113 fprintf (s
, " ref_maybe_used_by_call_p: "
114 HOST_WIDE_INT_PRINT_DEC
" disambiguations, "
115 HOST_WIDE_INT_PRINT_DEC
" queries\n",
116 alias_stats
.ref_maybe_used_by_call_p_no_alias
,
117 alias_stats
.refs_may_alias_p_no_alias
118 + alias_stats
.ref_maybe_used_by_call_p_may_alias
);
119 fprintf (s
, " call_may_clobber_ref_p: "
120 HOST_WIDE_INT_PRINT_DEC
" disambiguations, "
121 HOST_WIDE_INT_PRINT_DEC
" queries\n",
122 alias_stats
.call_may_clobber_ref_p_no_alias
,
123 alias_stats
.call_may_clobber_ref_p_no_alias
124 + alias_stats
.call_may_clobber_ref_p_may_alias
);
125 dump_alias_stats_in_alias_c (s
);
129 /* Return true, if dereferencing PTR may alias with a global variable. */
132 ptr_deref_may_alias_global_p (tree ptr
)
134 struct ptr_info_def
*pi
;
136 /* If we end up with a pointer constant here that may point
138 if (TREE_CODE (ptr
) != SSA_NAME
)
141 pi
= SSA_NAME_PTR_INFO (ptr
);
143 /* If we do not have points-to information for this variable,
148 /* ??? This does not use TBAA to prune globals ptr may not access. */
149 return pt_solution_includes_global (&pi
->pt
);
152 /* Return true if dereferencing PTR may alias DECL.
153 The caller is responsible for applying TBAA to see if PTR
154 may access DECL at all. */
157 ptr_deref_may_alias_decl_p (tree ptr
, tree decl
)
159 struct ptr_info_def
*pi
;
161 /* Conversions are irrelevant for points-to information and
162 data-dependence analysis can feed us those. */
165 /* Anything we do not explicilty handle aliases. */
166 if ((TREE_CODE (ptr
) != SSA_NAME
167 && TREE_CODE (ptr
) != ADDR_EXPR
168 && TREE_CODE (ptr
) != POINTER_PLUS_EXPR
)
169 || !POINTER_TYPE_P (TREE_TYPE (ptr
))
170 || (TREE_CODE (decl
) != VAR_DECL
171 && TREE_CODE (decl
) != PARM_DECL
172 && TREE_CODE (decl
) != RESULT_DECL
))
175 /* Disregard pointer offsetting. */
176 if (TREE_CODE (ptr
) == POINTER_PLUS_EXPR
)
180 ptr
= TREE_OPERAND (ptr
, 0);
182 while (TREE_CODE (ptr
) == POINTER_PLUS_EXPR
);
183 return ptr_deref_may_alias_decl_p (ptr
, decl
);
186 /* ADDR_EXPR pointers either just offset another pointer or directly
187 specify the pointed-to set. */
188 if (TREE_CODE (ptr
) == ADDR_EXPR
)
190 tree base
= get_base_address (TREE_OPERAND (ptr
, 0));
192 && (TREE_CODE (base
) == MEM_REF
193 || TREE_CODE (base
) == TARGET_MEM_REF
))
194 ptr
= TREE_OPERAND (base
, 0);
199 && CONSTANT_CLASS_P (base
))
205 /* Non-aliased variables can not be pointed to. */
206 if (!may_be_aliased (decl
))
209 /* If we do not have useful points-to information for this pointer
210 we cannot disambiguate anything else. */
211 pi
= SSA_NAME_PTR_INFO (ptr
);
215 return pt_solution_includes (&pi
->pt
, decl
);
218 /* Return true if dereferenced PTR1 and PTR2 may alias.
219 The caller is responsible for applying TBAA to see if accesses
220 through PTR1 and PTR2 may conflict at all. */
223 ptr_derefs_may_alias_p (tree ptr1
, tree ptr2
)
225 struct ptr_info_def
*pi1
, *pi2
;
227 /* Conversions are irrelevant for points-to information and
228 data-dependence analysis can feed us those. */
232 /* Disregard pointer offsetting. */
233 if (TREE_CODE (ptr1
) == POINTER_PLUS_EXPR
)
237 ptr1
= TREE_OPERAND (ptr1
, 0);
239 while (TREE_CODE (ptr1
) == POINTER_PLUS_EXPR
);
240 return ptr_derefs_may_alias_p (ptr1
, ptr2
);
242 if (TREE_CODE (ptr2
) == POINTER_PLUS_EXPR
)
246 ptr2
= TREE_OPERAND (ptr2
, 0);
248 while (TREE_CODE (ptr2
) == POINTER_PLUS_EXPR
);
249 return ptr_derefs_may_alias_p (ptr1
, ptr2
);
252 /* ADDR_EXPR pointers either just offset another pointer or directly
253 specify the pointed-to set. */
254 if (TREE_CODE (ptr1
) == ADDR_EXPR
)
256 tree base
= get_base_address (TREE_OPERAND (ptr1
, 0));
258 && (TREE_CODE (base
) == MEM_REF
259 || TREE_CODE (base
) == TARGET_MEM_REF
))
260 return ptr_derefs_may_alias_p (TREE_OPERAND (base
, 0), ptr2
);
263 return ptr_deref_may_alias_decl_p (ptr2
, base
);
267 if (TREE_CODE (ptr2
) == ADDR_EXPR
)
269 tree base
= get_base_address (TREE_OPERAND (ptr2
, 0));
271 && (TREE_CODE (base
) == MEM_REF
272 || TREE_CODE (base
) == TARGET_MEM_REF
))
273 return ptr_derefs_may_alias_p (ptr1
, TREE_OPERAND (base
, 0));
276 return ptr_deref_may_alias_decl_p (ptr1
, base
);
281 /* From here we require SSA name pointers. Anything else aliases. */
282 if (TREE_CODE (ptr1
) != SSA_NAME
283 || TREE_CODE (ptr2
) != SSA_NAME
284 || !POINTER_TYPE_P (TREE_TYPE (ptr1
))
285 || !POINTER_TYPE_P (TREE_TYPE (ptr2
)))
288 /* We may end up with two empty points-to solutions for two same pointers.
289 In this case we still want to say both pointers alias, so shortcut
294 /* If we do not have useful points-to information for either pointer
295 we cannot disambiguate anything else. */
296 pi1
= SSA_NAME_PTR_INFO (ptr1
);
297 pi2
= SSA_NAME_PTR_INFO (ptr2
);
301 /* ??? This does not use TBAA to prune decls from the intersection
302 that not both pointers may access. */
303 return pt_solutions_intersect (&pi1
->pt
, &pi2
->pt
);
306 /* Return true if dereferencing PTR may alias *REF.
307 The caller is responsible for applying TBAA to see if PTR
308 may access *REF at all. */
311 ptr_deref_may_alias_ref_p_1 (tree ptr
, ao_ref
*ref
)
313 tree base
= ao_ref_base (ref
);
315 if (TREE_CODE (base
) == MEM_REF
316 || TREE_CODE (base
) == TARGET_MEM_REF
)
317 return ptr_derefs_may_alias_p (ptr
, TREE_OPERAND (base
, 0));
318 else if (DECL_P (base
))
319 return ptr_deref_may_alias_decl_p (ptr
, base
);
324 /* Returns whether reference REF to BASE may refer to global memory. */
327 ref_may_alias_global_p_1 (tree base
)
330 return is_global_var (base
);
331 else if (TREE_CODE (base
) == MEM_REF
332 || TREE_CODE (base
) == TARGET_MEM_REF
)
333 return ptr_deref_may_alias_global_p (TREE_OPERAND (base
, 0));
338 ref_may_alias_global_p (ao_ref
*ref
)
340 tree base
= ao_ref_base (ref
);
341 return ref_may_alias_global_p_1 (base
);
345 ref_may_alias_global_p (tree ref
)
347 tree base
= get_base_address (ref
);
348 return ref_may_alias_global_p_1 (base
);
351 /* Return true whether STMT may clobber global memory. */
354 stmt_may_clobber_global_p (gimple
*stmt
)
358 if (!gimple_vdef (stmt
))
361 /* ??? We can ask the oracle whether an artificial pointer
362 dereference with a pointer with points-to information covering
363 all global memory (what about non-address taken memory?) maybe
364 clobbered by this call. As there is at the moment no convenient
365 way of doing that without generating garbage do some manual
367 ??? We could make a NULL ao_ref argument to the various
368 predicates special, meaning any global memory. */
370 switch (gimple_code (stmt
))
373 lhs
= gimple_assign_lhs (stmt
);
374 return (TREE_CODE (lhs
) != SSA_NAME
375 && ref_may_alias_global_p (lhs
));
384 /* Dump alias information on FILE. */
387 dump_alias_info (FILE *file
)
391 = lang_hooks
.decl_printable_name (current_function_decl
, 2);
394 fprintf (file
, "\n\nAlias information for %s\n\n", funcname
);
396 fprintf (file
, "Aliased symbols\n\n");
398 FOR_EACH_LOCAL_DECL (cfun
, i
, var
)
400 if (may_be_aliased (var
))
401 dump_variable (file
, var
);
404 fprintf (file
, "\nCall clobber information\n");
406 fprintf (file
, "\nESCAPED");
407 dump_points_to_solution (file
, &cfun
->gimple_df
->escaped
);
409 fprintf (file
, "\n\nFlow-insensitive points-to information\n\n");
411 for (i
= 1; i
< num_ssa_names
; i
++)
413 tree ptr
= ssa_name (i
);
414 struct ptr_info_def
*pi
;
417 || !POINTER_TYPE_P (TREE_TYPE (ptr
))
418 || SSA_NAME_IN_FREE_LIST (ptr
))
421 pi
= SSA_NAME_PTR_INFO (ptr
);
423 dump_points_to_info_for (file
, ptr
);
426 fprintf (file
, "\n");
430 /* Dump alias information on stderr. */
433 debug_alias_info (void)
435 dump_alias_info (stderr
);
439 /* Dump the points-to set *PT into FILE. */
442 dump_points_to_solution (FILE *file
, struct pt_solution
*pt
)
445 fprintf (file
, ", points-to anything");
448 fprintf (file
, ", points-to non-local");
451 fprintf (file
, ", points-to escaped");
454 fprintf (file
, ", points-to unit escaped");
457 fprintf (file
, ", points-to NULL");
461 fprintf (file
, ", points-to vars: ");
462 dump_decl_set (file
, pt
->vars
);
463 if (pt
->vars_contains_nonlocal
464 && pt
->vars_contains_escaped_heap
)
465 fprintf (file
, " (nonlocal, escaped heap)");
466 else if (pt
->vars_contains_nonlocal
467 && pt
->vars_contains_escaped
)
468 fprintf (file
, " (nonlocal, escaped)");
469 else if (pt
->vars_contains_nonlocal
)
470 fprintf (file
, " (nonlocal)");
471 else if (pt
->vars_contains_escaped_heap
)
472 fprintf (file
, " (escaped heap)");
473 else if (pt
->vars_contains_escaped
)
474 fprintf (file
, " (escaped)");
479 /* Unified dump function for pt_solution. */
482 debug (pt_solution
&ref
)
484 dump_points_to_solution (stderr
, &ref
);
488 debug (pt_solution
*ptr
)
493 fprintf (stderr
, "<nil>\n");
497 /* Dump points-to information for SSA_NAME PTR into FILE. */
500 dump_points_to_info_for (FILE *file
, tree ptr
)
502 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (ptr
);
504 print_generic_expr (file
, ptr
, dump_flags
);
507 dump_points_to_solution (file
, &pi
->pt
);
509 fprintf (file
, ", points-to anything");
511 fprintf (file
, "\n");
515 /* Dump points-to information for VAR into stderr. */
518 debug_points_to_info_for (tree var
)
520 dump_points_to_info_for (stderr
, var
);
524 /* Initializes the alias-oracle reference representation *R from REF. */
527 ao_ref_init (ao_ref
*r
, tree ref
)
534 r
->ref_alias_set
= -1;
535 r
->base_alias_set
= -1;
536 r
->volatile_p
= ref
? TREE_THIS_VOLATILE (ref
) : false;
539 /* Returns the base object of the memory reference *REF. */
542 ao_ref_base (ao_ref
*ref
)
548 ref
->base
= get_ref_base_and_extent (ref
->ref
, &ref
->offset
, &ref
->size
,
549 &ref
->max_size
, &reverse
);
553 /* Returns the base object alias set of the memory reference *REF. */
556 ao_ref_base_alias_set (ao_ref
*ref
)
559 if (ref
->base_alias_set
!= -1)
560 return ref
->base_alias_set
;
564 while (handled_component_p (base_ref
))
565 base_ref
= TREE_OPERAND (base_ref
, 0);
566 ref
->base_alias_set
= get_alias_set (base_ref
);
567 return ref
->base_alias_set
;
570 /* Returns the reference alias set of the memory reference *REF. */
573 ao_ref_alias_set (ao_ref
*ref
)
575 if (ref
->ref_alias_set
!= -1)
576 return ref
->ref_alias_set
;
577 ref
->ref_alias_set
= get_alias_set (ref
->ref
);
578 return ref
->ref_alias_set
;
581 /* Init an alias-oracle reference representation from a gimple pointer
582 PTR and a gimple size SIZE in bytes. If SIZE is NULL_TREE then the
583 size is assumed to be unknown. The access is assumed to be only
584 to or after of the pointer target, not before it. */
587 ao_ref_init_from_ptr_and_size (ao_ref
*ref
, tree ptr
, tree size
)
589 HOST_WIDE_INT t
, size_hwi
, extra_offset
= 0;
590 ref
->ref
= NULL_TREE
;
591 if (TREE_CODE (ptr
) == SSA_NAME
)
593 gimple
*stmt
= SSA_NAME_DEF_STMT (ptr
);
594 if (gimple_assign_single_p (stmt
)
595 && gimple_assign_rhs_code (stmt
) == ADDR_EXPR
)
596 ptr
= gimple_assign_rhs1 (stmt
);
597 else if (is_gimple_assign (stmt
)
598 && gimple_assign_rhs_code (stmt
) == POINTER_PLUS_EXPR
599 && TREE_CODE (gimple_assign_rhs2 (stmt
)) == INTEGER_CST
)
601 ptr
= gimple_assign_rhs1 (stmt
);
602 extra_offset
= BITS_PER_UNIT
603 * int_cst_value (gimple_assign_rhs2 (stmt
));
607 if (TREE_CODE (ptr
) == ADDR_EXPR
)
609 ref
->base
= get_addr_base_and_unit_offset (TREE_OPERAND (ptr
, 0), &t
);
611 ref
->offset
= BITS_PER_UNIT
* t
;
616 ref
->base
= get_base_address (TREE_OPERAND (ptr
, 0));
621 ref
->base
= build2 (MEM_REF
, char_type_node
,
622 ptr
, null_pointer_node
);
625 ref
->offset
+= extra_offset
;
627 && tree_fits_shwi_p (size
)
628 && (size_hwi
= tree_to_shwi (size
)) <= HOST_WIDE_INT_MAX
/ BITS_PER_UNIT
)
629 ref
->max_size
= ref
->size
= size_hwi
* BITS_PER_UNIT
;
631 ref
->max_size
= ref
->size
= -1;
632 ref
->ref_alias_set
= 0;
633 ref
->base_alias_set
= 0;
634 ref
->volatile_p
= false;
637 /* Return 1 if TYPE1 and TYPE2 are to be considered equivalent for the
638 purpose of TBAA. Return 0 if they are distinct and -1 if we cannot
642 same_type_for_tbaa (tree type1
, tree type2
)
644 type1
= TYPE_MAIN_VARIANT (type1
);
645 type2
= TYPE_MAIN_VARIANT (type2
);
647 /* If we would have to do structural comparison bail out. */
648 if (TYPE_STRUCTURAL_EQUALITY_P (type1
)
649 || TYPE_STRUCTURAL_EQUALITY_P (type2
))
652 /* Compare the canonical types. */
653 if (TYPE_CANONICAL (type1
) == TYPE_CANONICAL (type2
))
656 /* ??? Array types are not properly unified in all cases as we have
657 spurious changes in the index types for example. Removing this
658 causes all sorts of problems with the Fortran frontend. */
659 if (TREE_CODE (type1
) == ARRAY_TYPE
660 && TREE_CODE (type2
) == ARRAY_TYPE
)
663 /* ??? In Ada, an lvalue of an unconstrained type can be used to access an
664 object of one of its constrained subtypes, e.g. when a function with an
665 unconstrained parameter passed by reference is called on an object and
666 inlined. But, even in the case of a fixed size, type and subtypes are
667 not equivalent enough as to share the same TYPE_CANONICAL, since this
668 would mean that conversions between them are useless, whereas they are
669 not (e.g. type and subtypes can have different modes). So, in the end,
670 they are only guaranteed to have the same alias set. */
671 if (get_alias_set (type1
) == get_alias_set (type2
))
674 /* The types are known to be not equal. */
678 /* Determine if the two component references REF1 and REF2 which are
679 based on access types TYPE1 and TYPE2 and of which at least one is based
680 on an indirect reference may alias. REF2 is the only one that can
681 be a decl in which case REF2_IS_DECL is true.
682 REF1_ALIAS_SET, BASE1_ALIAS_SET, REF2_ALIAS_SET and BASE2_ALIAS_SET
683 are the respective alias sets. */
686 aliasing_component_refs_p (tree ref1
,
687 alias_set_type ref1_alias_set
,
688 alias_set_type base1_alias_set
,
689 HOST_WIDE_INT offset1
, HOST_WIDE_INT max_size1
,
691 alias_set_type ref2_alias_set
,
692 alias_set_type base2_alias_set
,
693 HOST_WIDE_INT offset2
, HOST_WIDE_INT max_size2
,
696 /* If one reference is a component references through pointers try to find a
697 common base and apply offset based disambiguation. This handles
699 struct A { int i; int j; } *q;
700 struct B { struct A a; int k; } *p;
701 disambiguating q->i and p->a.j. */
707 /* Choose bases and base types to search for. */
709 while (handled_component_p (base1
))
710 base1
= TREE_OPERAND (base1
, 0);
711 type1
= TREE_TYPE (base1
);
713 while (handled_component_p (base2
))
714 base2
= TREE_OPERAND (base2
, 0);
715 type2
= TREE_TYPE (base2
);
717 /* Now search for the type1 in the access path of ref2. This
718 would be a common base for doing offset based disambiguation on. */
720 while (handled_component_p (*refp
)
721 && same_type_for_tbaa (TREE_TYPE (*refp
), type1
) == 0)
722 refp
= &TREE_OPERAND (*refp
, 0);
723 same_p
= same_type_for_tbaa (TREE_TYPE (*refp
), type1
);
724 /* If we couldn't compare types we have to bail out. */
727 else if (same_p
== 1)
729 HOST_WIDE_INT offadj
, sztmp
, msztmp
;
731 get_ref_base_and_extent (*refp
, &offadj
, &sztmp
, &msztmp
, &reverse
);
733 get_ref_base_and_extent (base1
, &offadj
, &sztmp
, &msztmp
, &reverse
);
735 return ranges_overlap_p (offset1
, max_size1
, offset2
, max_size2
);
737 /* If we didn't find a common base, try the other way around. */
739 while (handled_component_p (*refp
)
740 && same_type_for_tbaa (TREE_TYPE (*refp
), type2
) == 0)
741 refp
= &TREE_OPERAND (*refp
, 0);
742 same_p
= same_type_for_tbaa (TREE_TYPE (*refp
), type2
);
743 /* If we couldn't compare types we have to bail out. */
746 else if (same_p
== 1)
748 HOST_WIDE_INT offadj
, sztmp
, msztmp
;
750 get_ref_base_and_extent (*refp
, &offadj
, &sztmp
, &msztmp
, &reverse
);
752 get_ref_base_and_extent (base2
, &offadj
, &sztmp
, &msztmp
, &reverse
);
754 return ranges_overlap_p (offset1
, max_size1
, offset2
, max_size2
);
757 /* If we have two type access paths B1.path1 and B2.path2 they may
758 only alias if either B1 is in B2.path2 or B2 is in B1.path1.
759 But we can still have a path that goes B1.path1...B2.path2 with
760 a part that we do not see. So we can only disambiguate now
761 if there is no B2 in the tail of path1 and no B1 on the
763 if (base1_alias_set
== ref2_alias_set
764 || alias_set_subset_of (base1_alias_set
, ref2_alias_set
))
766 /* If this is ptr vs. decl then we know there is no ptr ... decl path. */
768 return (base2_alias_set
== ref1_alias_set
769 || alias_set_subset_of (base2_alias_set
, ref1_alias_set
));
773 /* Return true if we can determine that component references REF1 and REF2,
774 that are within a common DECL, cannot overlap. */
777 nonoverlapping_component_refs_of_decl_p (tree ref1
, tree ref2
)
779 auto_vec
<tree
, 16> component_refs1
;
780 auto_vec
<tree
, 16> component_refs2
;
782 /* Create the stack of handled components for REF1. */
783 while (handled_component_p (ref1
))
785 component_refs1
.safe_push (ref1
);
786 ref1
= TREE_OPERAND (ref1
, 0);
788 if (TREE_CODE (ref1
) == MEM_REF
)
790 if (!integer_zerop (TREE_OPERAND (ref1
, 1)))
792 ref1
= TREE_OPERAND (TREE_OPERAND (ref1
, 0), 0);
795 /* Create the stack of handled components for REF2. */
796 while (handled_component_p (ref2
))
798 component_refs2
.safe_push (ref2
);
799 ref2
= TREE_OPERAND (ref2
, 0);
801 if (TREE_CODE (ref2
) == MEM_REF
)
803 if (!integer_zerop (TREE_OPERAND (ref2
, 1)))
805 ref2
= TREE_OPERAND (TREE_OPERAND (ref2
, 0), 0);
808 /* We must have the same base DECL. */
809 gcc_assert (ref1
== ref2
);
811 /* Pop the stacks in parallel and examine the COMPONENT_REFs of the same
812 rank. This is sufficient because we start from the same DECL and you
813 cannot reference several fields at a time with COMPONENT_REFs (unlike
814 with ARRAY_RANGE_REFs for arrays) so you always need the same number
815 of them to access a sub-component, unless you're in a union, in which
816 case the return value will precisely be false. */
821 if (component_refs1
.is_empty ())
823 ref1
= component_refs1
.pop ();
825 while (!RECORD_OR_UNION_TYPE_P (TREE_TYPE (TREE_OPERAND (ref1
, 0))));
829 if (component_refs2
.is_empty ())
831 ref2
= component_refs2
.pop ();
833 while (!RECORD_OR_UNION_TYPE_P (TREE_TYPE (TREE_OPERAND (ref2
, 0))));
835 /* Beware of BIT_FIELD_REF. */
836 if (TREE_CODE (ref1
) != COMPONENT_REF
837 || TREE_CODE (ref2
) != COMPONENT_REF
)
840 tree field1
= TREE_OPERAND (ref1
, 1);
841 tree field2
= TREE_OPERAND (ref2
, 1);
843 /* ??? We cannot simply use the type of operand #0 of the refs here
844 as the Fortran compiler smuggles type punning into COMPONENT_REFs
845 for common blocks instead of using unions like everyone else. */
846 tree type1
= DECL_CONTEXT (field1
);
847 tree type2
= DECL_CONTEXT (field2
);
849 /* We cannot disambiguate fields in a union or qualified union. */
850 if (type1
!= type2
|| TREE_CODE (type1
) != RECORD_TYPE
)
853 /* Different fields of the same record type cannot overlap.
854 ??? Bitfields can overlap at RTL level so punt on them. */
855 if (field1
!= field2
)
857 component_refs1
.release ();
858 component_refs2
.release ();
859 return !(DECL_BIT_FIELD (field1
) && DECL_BIT_FIELD (field2
));
864 component_refs1
.release ();
865 component_refs2
.release ();
869 /* qsort compare function to sort FIELD_DECLs after their
870 DECL_FIELD_CONTEXT TYPE_UID. */
873 ncr_compar (const void *field1_
, const void *field2_
)
875 const_tree field1
= *(const_tree
*) const_cast <void *>(field1_
);
876 const_tree field2
= *(const_tree
*) const_cast <void *>(field2_
);
877 unsigned int uid1
= TYPE_UID (DECL_FIELD_CONTEXT (field1
));
878 unsigned int uid2
= TYPE_UID (DECL_FIELD_CONTEXT (field2
));
881 else if (uid1
> uid2
)
886 /* Return true if we can determine that the fields referenced cannot
887 overlap for any pair of objects. */
890 nonoverlapping_component_refs_p (const_tree x
, const_tree y
)
892 if (!flag_strict_aliasing
894 || TREE_CODE (x
) != COMPONENT_REF
895 || TREE_CODE (y
) != COMPONENT_REF
)
898 auto_vec
<const_tree
, 16> fieldsx
;
899 while (TREE_CODE (x
) == COMPONENT_REF
)
901 tree field
= TREE_OPERAND (x
, 1);
902 tree type
= DECL_FIELD_CONTEXT (field
);
903 if (TREE_CODE (type
) == RECORD_TYPE
)
904 fieldsx
.safe_push (field
);
905 x
= TREE_OPERAND (x
, 0);
907 if (fieldsx
.length () == 0)
909 auto_vec
<const_tree
, 16> fieldsy
;
910 while (TREE_CODE (y
) == COMPONENT_REF
)
912 tree field
= TREE_OPERAND (y
, 1);
913 tree type
= DECL_FIELD_CONTEXT (field
);
914 if (TREE_CODE (type
) == RECORD_TYPE
)
915 fieldsy
.safe_push (TREE_OPERAND (y
, 1));
916 y
= TREE_OPERAND (y
, 0);
918 if (fieldsy
.length () == 0)
921 /* Most common case first. */
922 if (fieldsx
.length () == 1
923 && fieldsy
.length () == 1)
924 return ((DECL_FIELD_CONTEXT (fieldsx
[0])
925 == DECL_FIELD_CONTEXT (fieldsy
[0]))
926 && fieldsx
[0] != fieldsy
[0]
927 && !(DECL_BIT_FIELD (fieldsx
[0]) && DECL_BIT_FIELD (fieldsy
[0])));
929 if (fieldsx
.length () == 2)
931 if (ncr_compar (&fieldsx
[0], &fieldsx
[1]) == 1)
932 std::swap (fieldsx
[0], fieldsx
[1]);
935 fieldsx
.qsort (ncr_compar
);
937 if (fieldsy
.length () == 2)
939 if (ncr_compar (&fieldsy
[0], &fieldsy
[1]) == 1)
940 std::swap (fieldsy
[0], fieldsy
[1]);
943 fieldsy
.qsort (ncr_compar
);
945 unsigned i
= 0, j
= 0;
948 const_tree fieldx
= fieldsx
[i
];
949 const_tree fieldy
= fieldsy
[j
];
950 tree typex
= DECL_FIELD_CONTEXT (fieldx
);
951 tree typey
= DECL_FIELD_CONTEXT (fieldy
);
954 /* We're left with accessing different fields of a structure,
955 no possible overlap, unless they are both bitfields. */
956 if (fieldx
!= fieldy
)
957 return !(DECL_BIT_FIELD (fieldx
) && DECL_BIT_FIELD (fieldy
));
959 if (TYPE_UID (typex
) < TYPE_UID (typey
))
962 if (i
== fieldsx
.length ())
968 if (j
== fieldsy
.length ())
978 /* Return true if two memory references based on the variables BASE1
979 and BASE2 constrained to [OFFSET1, OFFSET1 + MAX_SIZE1) and
980 [OFFSET2, OFFSET2 + MAX_SIZE2) may alias. REF1 and REF2
981 if non-NULL are the complete memory reference trees. */
984 decl_refs_may_alias_p (tree ref1
, tree base1
,
985 HOST_WIDE_INT offset1
, HOST_WIDE_INT max_size1
,
986 tree ref2
, tree base2
,
987 HOST_WIDE_INT offset2
, HOST_WIDE_INT max_size2
)
989 gcc_checking_assert (DECL_P (base1
) && DECL_P (base2
));
991 /* If both references are based on different variables, they cannot alias. */
995 /* If both references are based on the same variable, they cannot alias if
996 the accesses do not overlap. */
997 if (!ranges_overlap_p (offset1
, max_size1
, offset2
, max_size2
))
1000 /* For components with variable position, the above test isn't sufficient,
1001 so we disambiguate component references manually. */
1003 && handled_component_p (ref1
) && handled_component_p (ref2
)
1004 && nonoverlapping_component_refs_of_decl_p (ref1
, ref2
))
1010 /* Return true if an indirect reference based on *PTR1 constrained
1011 to [OFFSET1, OFFSET1 + MAX_SIZE1) may alias a variable based on BASE2
1012 constrained to [OFFSET2, OFFSET2 + MAX_SIZE2). *PTR1 and BASE2 have
1013 the alias sets BASE1_ALIAS_SET and BASE2_ALIAS_SET which can be -1
1014 in which case they are computed on-demand. REF1 and REF2
1015 if non-NULL are the complete memory reference trees. */
1018 indirect_ref_may_alias_decl_p (tree ref1 ATTRIBUTE_UNUSED
, tree base1
,
1019 HOST_WIDE_INT offset1
,
1020 HOST_WIDE_INT max_size1 ATTRIBUTE_UNUSED
,
1021 alias_set_type ref1_alias_set
,
1022 alias_set_type base1_alias_set
,
1023 tree ref2 ATTRIBUTE_UNUSED
, tree base2
,
1024 HOST_WIDE_INT offset2
, HOST_WIDE_INT max_size2
,
1025 alias_set_type ref2_alias_set
,
1026 alias_set_type base2_alias_set
, bool tbaa_p
)
1029 tree ptrtype1
, dbase2
;
1030 HOST_WIDE_INT offset1p
= offset1
, offset2p
= offset2
;
1031 HOST_WIDE_INT doffset1
, doffset2
;
1033 gcc_checking_assert ((TREE_CODE (base1
) == MEM_REF
1034 || TREE_CODE (base1
) == TARGET_MEM_REF
)
1037 ptr1
= TREE_OPERAND (base1
, 0);
1039 /* The offset embedded in MEM_REFs can be negative. Bias them
1040 so that the resulting offset adjustment is positive. */
1041 offset_int moff
= mem_ref_offset (base1
);
1042 moff
= wi::lshift (moff
, LOG2_BITS_PER_UNIT
);
1043 if (wi::neg_p (moff
))
1044 offset2p
+= (-moff
).to_short_addr ();
1046 offset1p
+= moff
.to_short_addr ();
1048 /* If only one reference is based on a variable, they cannot alias if
1049 the pointer access is beyond the extent of the variable access.
1050 (the pointer base cannot validly point to an offset less than zero
1052 ??? IVOPTs creates bases that do not honor this restriction,
1053 so do not apply this optimization for TARGET_MEM_REFs. */
1054 if (TREE_CODE (base1
) != TARGET_MEM_REF
1055 && !ranges_overlap_p (MAX (0, offset1p
), -1, offset2p
, max_size2
))
1057 /* They also cannot alias if the pointer may not point to the decl. */
1058 if (!ptr_deref_may_alias_decl_p (ptr1
, base2
))
1061 /* Disambiguations that rely on strict aliasing rules follow. */
1062 if (!flag_strict_aliasing
|| !tbaa_p
)
1065 ptrtype1
= TREE_TYPE (TREE_OPERAND (base1
, 1));
1067 /* If the alias set for a pointer access is zero all bets are off. */
1068 if (base1_alias_set
== -1)
1069 base1_alias_set
= get_deref_alias_set (ptrtype1
);
1070 if (base1_alias_set
== 0)
1072 if (base2_alias_set
== -1)
1073 base2_alias_set
= get_alias_set (base2
);
1075 /* When we are trying to disambiguate an access with a pointer dereference
1076 as base versus one with a decl as base we can use both the size
1077 of the decl and its dynamic type for extra disambiguation.
1078 ??? We do not know anything about the dynamic type of the decl
1079 other than that its alias-set contains base2_alias_set as a subset
1080 which does not help us here. */
1081 /* As we know nothing useful about the dynamic type of the decl just
1082 use the usual conflict check rather than a subset test.
1083 ??? We could introduce -fvery-strict-aliasing when the language
1084 does not allow decls to have a dynamic type that differs from their
1085 static type. Then we can check
1086 !alias_set_subset_of (base1_alias_set, base2_alias_set) instead. */
1087 if (base1_alias_set
!= base2_alias_set
1088 && !alias_sets_conflict_p (base1_alias_set
, base2_alias_set
))
1090 /* If the size of the access relevant for TBAA through the pointer
1091 is bigger than the size of the decl we can't possibly access the
1092 decl via that pointer. */
1093 if (DECL_SIZE (base2
) && COMPLETE_TYPE_P (TREE_TYPE (ptrtype1
))
1094 && TREE_CODE (DECL_SIZE (base2
)) == INTEGER_CST
1095 && TREE_CODE (TYPE_SIZE (TREE_TYPE (ptrtype1
))) == INTEGER_CST
1096 /* ??? This in turn may run afoul when a decl of type T which is
1097 a member of union type U is accessed through a pointer to
1098 type U and sizeof T is smaller than sizeof U. */
1099 && TREE_CODE (TREE_TYPE (ptrtype1
)) != UNION_TYPE
1100 && TREE_CODE (TREE_TYPE (ptrtype1
)) != QUAL_UNION_TYPE
1101 && tree_int_cst_lt (DECL_SIZE (base2
), TYPE_SIZE (TREE_TYPE (ptrtype1
))))
1107 /* If the decl is accessed via a MEM_REF, reconstruct the base
1108 we can use for TBAA and an appropriately adjusted offset. */
1110 while (handled_component_p (dbase2
))
1111 dbase2
= TREE_OPERAND (dbase2
, 0);
1114 if (TREE_CODE (dbase2
) == MEM_REF
1115 || TREE_CODE (dbase2
) == TARGET_MEM_REF
)
1117 offset_int moff
= mem_ref_offset (dbase2
);
1118 moff
= wi::lshift (moff
, LOG2_BITS_PER_UNIT
);
1119 if (wi::neg_p (moff
))
1120 doffset1
-= (-moff
).to_short_addr ();
1122 doffset2
-= moff
.to_short_addr ();
1125 /* If either reference is view-converted, give up now. */
1126 if (same_type_for_tbaa (TREE_TYPE (base1
), TREE_TYPE (ptrtype1
)) != 1
1127 || same_type_for_tbaa (TREE_TYPE (dbase2
), TREE_TYPE (base2
)) != 1)
1130 /* If both references are through the same type, they do not alias
1131 if the accesses do not overlap. This does extra disambiguation
1132 for mixed/pointer accesses but requires strict aliasing.
1133 For MEM_REFs we require that the component-ref offset we computed
1134 is relative to the start of the type which we ensure by
1135 comparing rvalue and access type and disregarding the constant
1137 if ((TREE_CODE (base1
) != TARGET_MEM_REF
1138 || (!TMR_INDEX (base1
) && !TMR_INDEX2 (base1
)))
1139 && same_type_for_tbaa (TREE_TYPE (base1
), TREE_TYPE (dbase2
)) == 1)
1140 return ranges_overlap_p (doffset1
, max_size1
, doffset2
, max_size2
);
1143 && nonoverlapping_component_refs_p (ref1
, ref2
))
1146 /* Do access-path based disambiguation. */
1148 && (handled_component_p (ref1
) || handled_component_p (ref2
)))
1149 return aliasing_component_refs_p (ref1
,
1150 ref1_alias_set
, base1_alias_set
,
1153 ref2_alias_set
, base2_alias_set
,
1154 offset2
, max_size2
, true);
1159 /* Return true if two indirect references based on *PTR1
1160 and *PTR2 constrained to [OFFSET1, OFFSET1 + MAX_SIZE1) and
1161 [OFFSET2, OFFSET2 + MAX_SIZE2) may alias. *PTR1 and *PTR2 have
1162 the alias sets BASE1_ALIAS_SET and BASE2_ALIAS_SET which can be -1
1163 in which case they are computed on-demand. REF1 and REF2
1164 if non-NULL are the complete memory reference trees. */
1167 indirect_refs_may_alias_p (tree ref1 ATTRIBUTE_UNUSED
, tree base1
,
1168 HOST_WIDE_INT offset1
, HOST_WIDE_INT max_size1
,
1169 alias_set_type ref1_alias_set
,
1170 alias_set_type base1_alias_set
,
1171 tree ref2 ATTRIBUTE_UNUSED
, tree base2
,
1172 HOST_WIDE_INT offset2
, HOST_WIDE_INT max_size2
,
1173 alias_set_type ref2_alias_set
,
1174 alias_set_type base2_alias_set
, bool tbaa_p
)
1178 tree ptrtype1
, ptrtype2
;
1180 gcc_checking_assert ((TREE_CODE (base1
) == MEM_REF
1181 || TREE_CODE (base1
) == TARGET_MEM_REF
)
1182 && (TREE_CODE (base2
) == MEM_REF
1183 || TREE_CODE (base2
) == TARGET_MEM_REF
));
1185 ptr1
= TREE_OPERAND (base1
, 0);
1186 ptr2
= TREE_OPERAND (base2
, 0);
1188 /* If both bases are based on pointers they cannot alias if they may not
1189 point to the same memory object or if they point to the same object
1190 and the accesses do not overlap. */
1191 if ((!cfun
|| gimple_in_ssa_p (cfun
))
1192 && operand_equal_p (ptr1
, ptr2
, 0)
1193 && (((TREE_CODE (base1
) != TARGET_MEM_REF
1194 || (!TMR_INDEX (base1
) && !TMR_INDEX2 (base1
)))
1195 && (TREE_CODE (base2
) != TARGET_MEM_REF
1196 || (!TMR_INDEX (base2
) && !TMR_INDEX2 (base2
))))
1197 || (TREE_CODE (base1
) == TARGET_MEM_REF
1198 && TREE_CODE (base2
) == TARGET_MEM_REF
1199 && (TMR_STEP (base1
) == TMR_STEP (base2
)
1200 || (TMR_STEP (base1
) && TMR_STEP (base2
)
1201 && operand_equal_p (TMR_STEP (base1
),
1202 TMR_STEP (base2
), 0)))
1203 && (TMR_INDEX (base1
) == TMR_INDEX (base2
)
1204 || (TMR_INDEX (base1
) && TMR_INDEX (base2
)
1205 && operand_equal_p (TMR_INDEX (base1
),
1206 TMR_INDEX (base2
), 0)))
1207 && (TMR_INDEX2 (base1
) == TMR_INDEX2 (base2
)
1208 || (TMR_INDEX2 (base1
) && TMR_INDEX2 (base2
)
1209 && operand_equal_p (TMR_INDEX2 (base1
),
1210 TMR_INDEX2 (base2
), 0))))))
1213 /* The offset embedded in MEM_REFs can be negative. Bias them
1214 so that the resulting offset adjustment is positive. */
1215 moff
= mem_ref_offset (base1
);
1216 moff
= wi::lshift (moff
, LOG2_BITS_PER_UNIT
);
1217 if (wi::neg_p (moff
))
1218 offset2
+= (-moff
).to_short_addr ();
1220 offset1
+= moff
.to_shwi ();
1221 moff
= mem_ref_offset (base2
);
1222 moff
= wi::lshift (moff
, LOG2_BITS_PER_UNIT
);
1223 if (wi::neg_p (moff
))
1224 offset1
+= (-moff
).to_short_addr ();
1226 offset2
+= moff
.to_short_addr ();
1227 return ranges_overlap_p (offset1
, max_size1
, offset2
, max_size2
);
1229 if (!ptr_derefs_may_alias_p (ptr1
, ptr2
))
1232 /* Disambiguations that rely on strict aliasing rules follow. */
1233 if (!flag_strict_aliasing
|| !tbaa_p
)
1236 ptrtype1
= TREE_TYPE (TREE_OPERAND (base1
, 1));
1237 ptrtype2
= TREE_TYPE (TREE_OPERAND (base2
, 1));
1239 /* If the alias set for a pointer access is zero all bets are off. */
1240 if (base1_alias_set
== -1)
1241 base1_alias_set
= get_deref_alias_set (ptrtype1
);
1242 if (base1_alias_set
== 0)
1244 if (base2_alias_set
== -1)
1245 base2_alias_set
= get_deref_alias_set (ptrtype2
);
1246 if (base2_alias_set
== 0)
1249 /* If both references are through the same type, they do not alias
1250 if the accesses do not overlap. This does extra disambiguation
1251 for mixed/pointer accesses but requires strict aliasing. */
1252 if ((TREE_CODE (base1
) != TARGET_MEM_REF
1253 || (!TMR_INDEX (base1
) && !TMR_INDEX2 (base1
)))
1254 && (TREE_CODE (base2
) != TARGET_MEM_REF
1255 || (!TMR_INDEX (base2
) && !TMR_INDEX2 (base2
)))
1256 && same_type_for_tbaa (TREE_TYPE (base1
), TREE_TYPE (ptrtype1
)) == 1
1257 && same_type_for_tbaa (TREE_TYPE (base2
), TREE_TYPE (ptrtype2
)) == 1
1258 && same_type_for_tbaa (TREE_TYPE (ptrtype1
),
1259 TREE_TYPE (ptrtype2
)) == 1)
1260 return ranges_overlap_p (offset1
, max_size1
, offset2
, max_size2
);
1262 /* Do type-based disambiguation. */
1263 if (base1_alias_set
!= base2_alias_set
1264 && !alias_sets_conflict_p (base1_alias_set
, base2_alias_set
))
1267 /* If either reference is view-converted, give up now. */
1268 if (same_type_for_tbaa (TREE_TYPE (base1
), TREE_TYPE (ptrtype1
)) != 1
1269 || same_type_for_tbaa (TREE_TYPE (base2
), TREE_TYPE (ptrtype2
)) != 1)
1273 && nonoverlapping_component_refs_p (ref1
, ref2
))
1276 /* Do access-path based disambiguation. */
1278 && (handled_component_p (ref1
) || handled_component_p (ref2
)))
1279 return aliasing_component_refs_p (ref1
,
1280 ref1_alias_set
, base1_alias_set
,
1283 ref2_alias_set
, base2_alias_set
,
1284 offset2
, max_size2
, false);
1289 /* Return true, if the two memory references REF1 and REF2 may alias. */
1292 refs_may_alias_p_1 (ao_ref
*ref1
, ao_ref
*ref2
, bool tbaa_p
)
1295 HOST_WIDE_INT offset1
= 0, offset2
= 0;
1296 HOST_WIDE_INT max_size1
= -1, max_size2
= -1;
1297 bool var1_p
, var2_p
, ind1_p
, ind2_p
;
1299 gcc_checking_assert ((!ref1
->ref
1300 || TREE_CODE (ref1
->ref
) == SSA_NAME
1301 || DECL_P (ref1
->ref
)
1302 || TREE_CODE (ref1
->ref
) == STRING_CST
1303 || handled_component_p (ref1
->ref
)
1304 || TREE_CODE (ref1
->ref
) == MEM_REF
1305 || TREE_CODE (ref1
->ref
) == TARGET_MEM_REF
)
1307 || TREE_CODE (ref2
->ref
) == SSA_NAME
1308 || DECL_P (ref2
->ref
)
1309 || TREE_CODE (ref2
->ref
) == STRING_CST
1310 || handled_component_p (ref2
->ref
)
1311 || TREE_CODE (ref2
->ref
) == MEM_REF
1312 || TREE_CODE (ref2
->ref
) == TARGET_MEM_REF
));
1314 /* Decompose the references into their base objects and the access. */
1315 base1
= ao_ref_base (ref1
);
1316 offset1
= ref1
->offset
;
1317 max_size1
= ref1
->max_size
;
1318 base2
= ao_ref_base (ref2
);
1319 offset2
= ref2
->offset
;
1320 max_size2
= ref2
->max_size
;
1322 /* We can end up with registers or constants as bases for example from
1323 *D.1663_44 = VIEW_CONVERT_EXPR<struct DB_LSN>(__tmp$B0F64_59);
1324 which is seen as a struct copy. */
1325 if (TREE_CODE (base1
) == SSA_NAME
1326 || TREE_CODE (base1
) == CONST_DECL
1327 || TREE_CODE (base1
) == CONSTRUCTOR
1328 || TREE_CODE (base1
) == ADDR_EXPR
1329 || CONSTANT_CLASS_P (base1
)
1330 || TREE_CODE (base2
) == SSA_NAME
1331 || TREE_CODE (base2
) == CONST_DECL
1332 || TREE_CODE (base2
) == CONSTRUCTOR
1333 || TREE_CODE (base2
) == ADDR_EXPR
1334 || CONSTANT_CLASS_P (base2
))
1337 /* We can end up referring to code via function and label decls.
1338 As we likely do not properly track code aliases conservatively
1340 if (TREE_CODE (base1
) == FUNCTION_DECL
1341 || TREE_CODE (base1
) == LABEL_DECL
1342 || TREE_CODE (base2
) == FUNCTION_DECL
1343 || TREE_CODE (base2
) == LABEL_DECL
)
1346 /* Two volatile accesses always conflict. */
1347 if (ref1
->volatile_p
1348 && ref2
->volatile_p
)
1351 /* Defer to simple offset based disambiguation if we have
1352 references based on two decls. Do this before defering to
1353 TBAA to handle must-alias cases in conformance with the
1354 GCC extension of allowing type-punning through unions. */
1355 var1_p
= DECL_P (base1
);
1356 var2_p
= DECL_P (base2
);
1357 if (var1_p
&& var2_p
)
1358 return decl_refs_may_alias_p (ref1
->ref
, base1
, offset1
, max_size1
,
1359 ref2
->ref
, base2
, offset2
, max_size2
);
1361 /* Handle restrict based accesses.
1362 ??? ao_ref_base strips inner MEM_REF [&decl], recover from that
1364 tree rbase1
= base1
;
1365 tree rbase2
= base2
;
1370 while (handled_component_p (rbase1
))
1371 rbase1
= TREE_OPERAND (rbase1
, 0);
1377 while (handled_component_p (rbase2
))
1378 rbase2
= TREE_OPERAND (rbase2
, 0);
1380 if (rbase1
&& rbase2
1381 && (TREE_CODE (base1
) == MEM_REF
|| TREE_CODE (base1
) == TARGET_MEM_REF
)
1382 && (TREE_CODE (base2
) == MEM_REF
|| TREE_CODE (base2
) == TARGET_MEM_REF
)
1383 /* If the accesses are in the same restrict clique... */
1384 && MR_DEPENDENCE_CLIQUE (base1
) == MR_DEPENDENCE_CLIQUE (base2
)
1385 /* But based on different pointers they do not alias. */
1386 && MR_DEPENDENCE_BASE (base1
) != MR_DEPENDENCE_BASE (base2
))
1389 ind1_p
= (TREE_CODE (base1
) == MEM_REF
1390 || TREE_CODE (base1
) == TARGET_MEM_REF
);
1391 ind2_p
= (TREE_CODE (base2
) == MEM_REF
1392 || TREE_CODE (base2
) == TARGET_MEM_REF
);
1394 /* Canonicalize the pointer-vs-decl case. */
1395 if (ind1_p
&& var2_p
)
1397 std::swap (offset1
, offset2
);
1398 std::swap (max_size1
, max_size2
);
1399 std::swap (base1
, base2
);
1400 std::swap (ref1
, ref2
);
1407 /* First defer to TBAA if possible. */
1409 && flag_strict_aliasing
1410 && !alias_sets_conflict_p (ao_ref_alias_set (ref1
),
1411 ao_ref_alias_set (ref2
)))
1414 /* Dispatch to the pointer-vs-decl or pointer-vs-pointer disambiguators. */
1415 if (var1_p
&& ind2_p
)
1416 return indirect_ref_may_alias_decl_p (ref2
->ref
, base2
,
1418 ao_ref_alias_set (ref2
), -1,
1421 ao_ref_alias_set (ref1
),
1422 ao_ref_base_alias_set (ref1
),
1424 else if (ind1_p
&& ind2_p
)
1425 return indirect_refs_may_alias_p (ref1
->ref
, base1
,
1427 ao_ref_alias_set (ref1
), -1,
1430 ao_ref_alias_set (ref2
), -1,
1437 refs_may_alias_p (tree ref1
, ao_ref
*ref2
)
1440 ao_ref_init (&r1
, ref1
);
1441 return refs_may_alias_p_1 (&r1
, ref2
, true);
1445 refs_may_alias_p (tree ref1
, tree ref2
)
1449 ao_ref_init (&r1
, ref1
);
1450 ao_ref_init (&r2
, ref2
);
1451 res
= refs_may_alias_p_1 (&r1
, &r2
, true);
1453 ++alias_stats
.refs_may_alias_p_may_alias
;
1455 ++alias_stats
.refs_may_alias_p_no_alias
;
1459 /* Returns true if there is a anti-dependence for the STORE that
1460 executes after the LOAD. */
1463 refs_anti_dependent_p (tree load
, tree store
)
1466 ao_ref_init (&r1
, load
);
1467 ao_ref_init (&r2
, store
);
1468 return refs_may_alias_p_1 (&r1
, &r2
, false);
1471 /* Returns true if there is a output dependence for the stores
1472 STORE1 and STORE2. */
1475 refs_output_dependent_p (tree store1
, tree store2
)
1478 ao_ref_init (&r1
, store1
);
1479 ao_ref_init (&r2
, store2
);
1480 return refs_may_alias_p_1 (&r1
, &r2
, false);
1483 /* If the call CALL may use the memory reference REF return true,
1484 otherwise return false. */
1487 ref_maybe_used_by_call_p_1 (gcall
*call
, ao_ref
*ref
)
1491 int flags
= gimple_call_flags (call
);
1493 /* Const functions without a static chain do not implicitly use memory. */
1494 if (!gimple_call_chain (call
)
1495 && (flags
& (ECF_CONST
|ECF_NOVOPS
)))
1498 base
= ao_ref_base (ref
);
1502 /* A call that is not without side-effects might involve volatile
1503 accesses and thus conflicts with all other volatile accesses. */
1504 if (ref
->volatile_p
)
1507 /* If the reference is based on a decl that is not aliased the call
1508 cannot possibly use it. */
1510 && !may_be_aliased (base
)
1511 /* But local statics can be used through recursion. */
1512 && !is_global_var (base
))
1515 callee
= gimple_call_fndecl (call
);
1517 /* Handle those builtin functions explicitly that do not act as
1518 escape points. See tree-ssa-structalias.c:find_func_aliases
1519 for the list of builtins we might need to handle here. */
1520 if (callee
!= NULL_TREE
1521 && gimple_call_builtin_p (call
, BUILT_IN_NORMAL
))
1522 switch (DECL_FUNCTION_CODE (callee
))
1524 /* All the following functions read memory pointed to by
1525 their second argument. strcat/strncat additionally
1526 reads memory pointed to by the first argument. */
1527 case BUILT_IN_STRCAT
:
1528 case BUILT_IN_STRNCAT
:
1531 ao_ref_init_from_ptr_and_size (&dref
,
1532 gimple_call_arg (call
, 0),
1534 if (refs_may_alias_p_1 (&dref
, ref
, false))
1538 case BUILT_IN_STRCPY
:
1539 case BUILT_IN_STRNCPY
:
1540 case BUILT_IN_MEMCPY
:
1541 case BUILT_IN_MEMMOVE
:
1542 case BUILT_IN_MEMPCPY
:
1543 case BUILT_IN_STPCPY
:
1544 case BUILT_IN_STPNCPY
:
1545 case BUILT_IN_TM_MEMCPY
:
1546 case BUILT_IN_TM_MEMMOVE
:
1549 tree size
= NULL_TREE
;
1550 if (gimple_call_num_args (call
) == 3)
1551 size
= gimple_call_arg (call
, 2);
1552 ao_ref_init_from_ptr_and_size (&dref
,
1553 gimple_call_arg (call
, 1),
1555 return refs_may_alias_p_1 (&dref
, ref
, false);
1557 case BUILT_IN_STRCAT_CHK
:
1558 case BUILT_IN_STRNCAT_CHK
:
1561 ao_ref_init_from_ptr_and_size (&dref
,
1562 gimple_call_arg (call
, 0),
1564 if (refs_may_alias_p_1 (&dref
, ref
, false))
1568 case BUILT_IN_STRCPY_CHK
:
1569 case BUILT_IN_STRNCPY_CHK
:
1570 case BUILT_IN_MEMCPY_CHK
:
1571 case BUILT_IN_MEMMOVE_CHK
:
1572 case BUILT_IN_MEMPCPY_CHK
:
1573 case BUILT_IN_STPCPY_CHK
:
1574 case BUILT_IN_STPNCPY_CHK
:
1577 tree size
= NULL_TREE
;
1578 if (gimple_call_num_args (call
) == 4)
1579 size
= gimple_call_arg (call
, 2);
1580 ao_ref_init_from_ptr_and_size (&dref
,
1581 gimple_call_arg (call
, 1),
1583 return refs_may_alias_p_1 (&dref
, ref
, false);
1585 case BUILT_IN_BCOPY
:
1588 tree size
= gimple_call_arg (call
, 2);
1589 ao_ref_init_from_ptr_and_size (&dref
,
1590 gimple_call_arg (call
, 0),
1592 return refs_may_alias_p_1 (&dref
, ref
, false);
1595 /* The following functions read memory pointed to by their
1597 CASE_BUILT_IN_TM_LOAD (1):
1598 CASE_BUILT_IN_TM_LOAD (2):
1599 CASE_BUILT_IN_TM_LOAD (4):
1600 CASE_BUILT_IN_TM_LOAD (8):
1601 CASE_BUILT_IN_TM_LOAD (FLOAT
):
1602 CASE_BUILT_IN_TM_LOAD (DOUBLE
):
1603 CASE_BUILT_IN_TM_LOAD (LDOUBLE
):
1604 CASE_BUILT_IN_TM_LOAD (M64
):
1605 CASE_BUILT_IN_TM_LOAD (M128
):
1606 CASE_BUILT_IN_TM_LOAD (M256
):
1607 case BUILT_IN_TM_LOG
:
1608 case BUILT_IN_TM_LOG_1
:
1609 case BUILT_IN_TM_LOG_2
:
1610 case BUILT_IN_TM_LOG_4
:
1611 case BUILT_IN_TM_LOG_8
:
1612 case BUILT_IN_TM_LOG_FLOAT
:
1613 case BUILT_IN_TM_LOG_DOUBLE
:
1614 case BUILT_IN_TM_LOG_LDOUBLE
:
1615 case BUILT_IN_TM_LOG_M64
:
1616 case BUILT_IN_TM_LOG_M128
:
1617 case BUILT_IN_TM_LOG_M256
:
1618 return ptr_deref_may_alias_ref_p_1 (gimple_call_arg (call
, 0), ref
);
1620 /* These read memory pointed to by the first argument. */
1621 case BUILT_IN_STRDUP
:
1622 case BUILT_IN_STRNDUP
:
1623 case BUILT_IN_REALLOC
:
1626 tree size
= NULL_TREE
;
1627 if (gimple_call_num_args (call
) == 2)
1628 size
= gimple_call_arg (call
, 1);
1629 ao_ref_init_from_ptr_and_size (&dref
,
1630 gimple_call_arg (call
, 0),
1632 return refs_may_alias_p_1 (&dref
, ref
, false);
1634 /* These read memory pointed to by the first argument. */
1635 case BUILT_IN_INDEX
:
1636 case BUILT_IN_STRCHR
:
1637 case BUILT_IN_STRRCHR
:
1640 ao_ref_init_from_ptr_and_size (&dref
,
1641 gimple_call_arg (call
, 0),
1643 return refs_may_alias_p_1 (&dref
, ref
, false);
1645 /* These read memory pointed to by the first argument with size
1646 in the third argument. */
1647 case BUILT_IN_MEMCHR
:
1650 ao_ref_init_from_ptr_and_size (&dref
,
1651 gimple_call_arg (call
, 0),
1652 gimple_call_arg (call
, 2));
1653 return refs_may_alias_p_1 (&dref
, ref
, false);
1655 /* These read memory pointed to by the first and second arguments. */
1656 case BUILT_IN_STRSTR
:
1657 case BUILT_IN_STRPBRK
:
1660 ao_ref_init_from_ptr_and_size (&dref
,
1661 gimple_call_arg (call
, 0),
1663 if (refs_may_alias_p_1 (&dref
, ref
, false))
1665 ao_ref_init_from_ptr_and_size (&dref
,
1666 gimple_call_arg (call
, 1),
1668 return refs_may_alias_p_1 (&dref
, ref
, false);
1671 /* The following builtins do not read from memory. */
1673 case BUILT_IN_MALLOC
:
1674 case BUILT_IN_POSIX_MEMALIGN
:
1675 case BUILT_IN_ALIGNED_ALLOC
:
1676 case BUILT_IN_CALLOC
:
1677 case BUILT_IN_ALLOCA
:
1678 case BUILT_IN_ALLOCA_WITH_ALIGN
:
1679 case BUILT_IN_STACK_SAVE
:
1680 case BUILT_IN_STACK_RESTORE
:
1681 case BUILT_IN_MEMSET
:
1682 case BUILT_IN_TM_MEMSET
:
1683 case BUILT_IN_MEMSET_CHK
:
1684 case BUILT_IN_FREXP
:
1685 case BUILT_IN_FREXPF
:
1686 case BUILT_IN_FREXPL
:
1687 case BUILT_IN_GAMMA_R
:
1688 case BUILT_IN_GAMMAF_R
:
1689 case BUILT_IN_GAMMAL_R
:
1690 case BUILT_IN_LGAMMA_R
:
1691 case BUILT_IN_LGAMMAF_R
:
1692 case BUILT_IN_LGAMMAL_R
:
1694 case BUILT_IN_MODFF
:
1695 case BUILT_IN_MODFL
:
1696 case BUILT_IN_REMQUO
:
1697 case BUILT_IN_REMQUOF
:
1698 case BUILT_IN_REMQUOL
:
1699 case BUILT_IN_SINCOS
:
1700 case BUILT_IN_SINCOSF
:
1701 case BUILT_IN_SINCOSL
:
1702 case BUILT_IN_ASSUME_ALIGNED
:
1703 case BUILT_IN_VA_END
:
1705 /* __sync_* builtins and some OpenMP builtins act as threading
1707 #undef DEF_SYNC_BUILTIN
1708 #define DEF_SYNC_BUILTIN(ENUM, NAME, TYPE, ATTRS) case ENUM:
1709 #include "sync-builtins.def"
1710 #undef DEF_SYNC_BUILTIN
1711 case BUILT_IN_GOMP_ATOMIC_START
:
1712 case BUILT_IN_GOMP_ATOMIC_END
:
1713 case BUILT_IN_GOMP_BARRIER
:
1714 case BUILT_IN_GOMP_BARRIER_CANCEL
:
1715 case BUILT_IN_GOMP_TASKWAIT
:
1716 case BUILT_IN_GOMP_TASKGROUP_END
:
1717 case BUILT_IN_GOMP_CRITICAL_START
:
1718 case BUILT_IN_GOMP_CRITICAL_END
:
1719 case BUILT_IN_GOMP_CRITICAL_NAME_START
:
1720 case BUILT_IN_GOMP_CRITICAL_NAME_END
:
1721 case BUILT_IN_GOMP_LOOP_END
:
1722 case BUILT_IN_GOMP_LOOP_END_CANCEL
:
1723 case BUILT_IN_GOMP_ORDERED_START
:
1724 case BUILT_IN_GOMP_ORDERED_END
:
1725 case BUILT_IN_GOMP_SECTIONS_END
:
1726 case BUILT_IN_GOMP_SECTIONS_END_CANCEL
:
1727 case BUILT_IN_GOMP_SINGLE_COPY_START
:
1728 case BUILT_IN_GOMP_SINGLE_COPY_END
:
1732 /* Fallthru to general call handling. */;
1735 /* Check if base is a global static variable that is not read
1737 if (callee
!= NULL_TREE
1738 && TREE_CODE (base
) == VAR_DECL
1739 && TREE_STATIC (base
))
1741 struct cgraph_node
*node
= cgraph_node::get (callee
);
1743 /* FIXME: Callee can be an OMP builtin that does not have a call graph
1744 node yet. We should enforce that there are nodes for all decls in the
1745 IL and remove this check instead. */
1748 enum availability avail
;
1751 node
= node
->ultimate_alias_target (&avail
);
1752 if (avail
>= AVAIL_AVAILABLE
1753 && (not_read
= ipa_reference_get_not_read_global (node
))
1754 && bitmap_bit_p (not_read
, ipa_reference_var_uid (base
)))
1759 /* Check if the base variable is call-used. */
1762 if (pt_solution_includes (gimple_call_use_set (call
), base
))
1765 else if ((TREE_CODE (base
) == MEM_REF
1766 || TREE_CODE (base
) == TARGET_MEM_REF
)
1767 && TREE_CODE (TREE_OPERAND (base
, 0)) == SSA_NAME
)
1769 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (TREE_OPERAND (base
, 0));
1773 if (pt_solutions_intersect (gimple_call_use_set (call
), &pi
->pt
))
1779 /* Inspect call arguments for passed-by-value aliases. */
1781 for (i
= 0; i
< gimple_call_num_args (call
); ++i
)
1783 tree op
= gimple_call_arg (call
, i
);
1784 int flags
= gimple_call_arg_flags (call
, i
);
1786 if (flags
& EAF_UNUSED
)
1789 if (TREE_CODE (op
) == WITH_SIZE_EXPR
)
1790 op
= TREE_OPERAND (op
, 0);
1792 if (TREE_CODE (op
) != SSA_NAME
1793 && !is_gimple_min_invariant (op
))
1796 ao_ref_init (&r
, op
);
1797 if (refs_may_alias_p_1 (&r
, ref
, true))
1806 ref_maybe_used_by_call_p (gcall
*call
, ao_ref
*ref
)
1809 res
= ref_maybe_used_by_call_p_1 (call
, ref
);
1811 ++alias_stats
.ref_maybe_used_by_call_p_may_alias
;
1813 ++alias_stats
.ref_maybe_used_by_call_p_no_alias
;
1818 /* If the statement STMT may use the memory reference REF return
1819 true, otherwise return false. */
1822 ref_maybe_used_by_stmt_p (gimple
*stmt
, ao_ref
*ref
)
1824 if (is_gimple_assign (stmt
))
1828 /* All memory assign statements are single. */
1829 if (!gimple_assign_single_p (stmt
))
1832 rhs
= gimple_assign_rhs1 (stmt
);
1833 if (is_gimple_reg (rhs
)
1834 || is_gimple_min_invariant (rhs
)
1835 || gimple_assign_rhs_code (stmt
) == CONSTRUCTOR
)
1838 return refs_may_alias_p (rhs
, ref
);
1840 else if (is_gimple_call (stmt
))
1841 return ref_maybe_used_by_call_p (as_a
<gcall
*> (stmt
), ref
);
1842 else if (greturn
*return_stmt
= dyn_cast
<greturn
*> (stmt
))
1844 tree retval
= gimple_return_retval (return_stmt
);
1846 && TREE_CODE (retval
) != SSA_NAME
1847 && !is_gimple_min_invariant (retval
)
1848 && refs_may_alias_p (retval
, ref
))
1850 /* If ref escapes the function then the return acts as a use. */
1851 tree base
= ao_ref_base (ref
);
1854 else if (DECL_P (base
))
1855 return is_global_var (base
);
1856 else if (TREE_CODE (base
) == MEM_REF
1857 || TREE_CODE (base
) == TARGET_MEM_REF
)
1858 return ptr_deref_may_alias_global_p (TREE_OPERAND (base
, 0));
1866 ref_maybe_used_by_stmt_p (gimple
*stmt
, tree ref
)
1869 ao_ref_init (&r
, ref
);
1870 return ref_maybe_used_by_stmt_p (stmt
, &r
);
1873 /* If the call in statement CALL may clobber the memory reference REF
1874 return true, otherwise return false. */
1877 call_may_clobber_ref_p_1 (gcall
*call
, ao_ref
*ref
)
1882 /* If the call is pure or const it cannot clobber anything. */
1883 if (gimple_call_flags (call
)
1884 & (ECF_PURE
|ECF_CONST
|ECF_LOOPING_CONST_OR_PURE
|ECF_NOVOPS
))
1886 if (gimple_call_internal_p (call
))
1887 switch (gimple_call_internal_fn (call
))
1889 /* Treat these internal calls like ECF_PURE for aliasing,
1890 they don't write to any memory the program should care about.
1891 They have important other side-effects, and read memory,
1892 so can't be ECF_NOVOPS. */
1893 case IFN_UBSAN_NULL
:
1894 case IFN_UBSAN_BOUNDS
:
1895 case IFN_UBSAN_VPTR
:
1896 case IFN_UBSAN_OBJECT_SIZE
:
1897 case IFN_ASAN_CHECK
:
1903 base
= ao_ref_base (ref
);
1907 if (TREE_CODE (base
) == SSA_NAME
1908 || CONSTANT_CLASS_P (base
))
1911 /* A call that is not without side-effects might involve volatile
1912 accesses and thus conflicts with all other volatile accesses. */
1913 if (ref
->volatile_p
)
1916 /* If the reference is based on a decl that is not aliased the call
1917 cannot possibly clobber it. */
1919 && !may_be_aliased (base
)
1920 /* But local non-readonly statics can be modified through recursion
1921 or the call may implement a threading barrier which we must
1922 treat as may-def. */
1923 && (TREE_READONLY (base
)
1924 || !is_global_var (base
)))
1927 callee
= gimple_call_fndecl (call
);
1929 /* Handle those builtin functions explicitly that do not act as
1930 escape points. See tree-ssa-structalias.c:find_func_aliases
1931 for the list of builtins we might need to handle here. */
1932 if (callee
!= NULL_TREE
1933 && gimple_call_builtin_p (call
, BUILT_IN_NORMAL
))
1934 switch (DECL_FUNCTION_CODE (callee
))
1936 /* All the following functions clobber memory pointed to by
1937 their first argument. */
1938 case BUILT_IN_STRCPY
:
1939 case BUILT_IN_STRNCPY
:
1940 case BUILT_IN_MEMCPY
:
1941 case BUILT_IN_MEMMOVE
:
1942 case BUILT_IN_MEMPCPY
:
1943 case BUILT_IN_STPCPY
:
1944 case BUILT_IN_STPNCPY
:
1945 case BUILT_IN_STRCAT
:
1946 case BUILT_IN_STRNCAT
:
1947 case BUILT_IN_MEMSET
:
1948 case BUILT_IN_TM_MEMSET
:
1949 CASE_BUILT_IN_TM_STORE (1):
1950 CASE_BUILT_IN_TM_STORE (2):
1951 CASE_BUILT_IN_TM_STORE (4):
1952 CASE_BUILT_IN_TM_STORE (8):
1953 CASE_BUILT_IN_TM_STORE (FLOAT
):
1954 CASE_BUILT_IN_TM_STORE (DOUBLE
):
1955 CASE_BUILT_IN_TM_STORE (LDOUBLE
):
1956 CASE_BUILT_IN_TM_STORE (M64
):
1957 CASE_BUILT_IN_TM_STORE (M128
):
1958 CASE_BUILT_IN_TM_STORE (M256
):
1959 case BUILT_IN_TM_MEMCPY
:
1960 case BUILT_IN_TM_MEMMOVE
:
1963 tree size
= NULL_TREE
;
1964 /* Don't pass in size for strncat, as the maximum size
1965 is strlen (dest) + n + 1 instead of n, resp.
1966 n + 1 at dest + strlen (dest), but strlen (dest) isn't
1968 if (gimple_call_num_args (call
) == 3
1969 && DECL_FUNCTION_CODE (callee
) != BUILT_IN_STRNCAT
)
1970 size
= gimple_call_arg (call
, 2);
1971 ao_ref_init_from_ptr_and_size (&dref
,
1972 gimple_call_arg (call
, 0),
1974 return refs_may_alias_p_1 (&dref
, ref
, false);
1976 case BUILT_IN_STRCPY_CHK
:
1977 case BUILT_IN_STRNCPY_CHK
:
1978 case BUILT_IN_MEMCPY_CHK
:
1979 case BUILT_IN_MEMMOVE_CHK
:
1980 case BUILT_IN_MEMPCPY_CHK
:
1981 case BUILT_IN_STPCPY_CHK
:
1982 case BUILT_IN_STPNCPY_CHK
:
1983 case BUILT_IN_STRCAT_CHK
:
1984 case BUILT_IN_STRNCAT_CHK
:
1985 case BUILT_IN_MEMSET_CHK
:
1988 tree size
= NULL_TREE
;
1989 /* Don't pass in size for __strncat_chk, as the maximum size
1990 is strlen (dest) + n + 1 instead of n, resp.
1991 n + 1 at dest + strlen (dest), but strlen (dest) isn't
1993 if (gimple_call_num_args (call
) == 4
1994 && DECL_FUNCTION_CODE (callee
) != BUILT_IN_STRNCAT_CHK
)
1995 size
= gimple_call_arg (call
, 2);
1996 ao_ref_init_from_ptr_and_size (&dref
,
1997 gimple_call_arg (call
, 0),
1999 return refs_may_alias_p_1 (&dref
, ref
, false);
2001 case BUILT_IN_BCOPY
:
2004 tree size
= gimple_call_arg (call
, 2);
2005 ao_ref_init_from_ptr_and_size (&dref
,
2006 gimple_call_arg (call
, 1),
2008 return refs_may_alias_p_1 (&dref
, ref
, false);
2010 /* Allocating memory does not have any side-effects apart from
2011 being the definition point for the pointer. */
2012 case BUILT_IN_MALLOC
:
2013 case BUILT_IN_ALIGNED_ALLOC
:
2014 case BUILT_IN_CALLOC
:
2015 case BUILT_IN_STRDUP
:
2016 case BUILT_IN_STRNDUP
:
2017 /* Unix98 specifies that errno is set on allocation failure. */
2019 && targetm
.ref_may_alias_errno (ref
))
2022 case BUILT_IN_STACK_SAVE
:
2023 case BUILT_IN_ALLOCA
:
2024 case BUILT_IN_ALLOCA_WITH_ALIGN
:
2025 case BUILT_IN_ASSUME_ALIGNED
:
2027 /* But posix_memalign stores a pointer into the memory pointed to
2028 by its first argument. */
2029 case BUILT_IN_POSIX_MEMALIGN
:
2031 tree ptrptr
= gimple_call_arg (call
, 0);
2033 ao_ref_init_from_ptr_and_size (&dref
, ptrptr
,
2034 TYPE_SIZE_UNIT (ptr_type_node
));
2035 return (refs_may_alias_p_1 (&dref
, ref
, false)
2037 && targetm
.ref_may_alias_errno (ref
)));
2039 /* Freeing memory kills the pointed-to memory. More importantly
2040 the call has to serve as a barrier for moving loads and stores
2043 case BUILT_IN_VA_END
:
2045 tree ptr
= gimple_call_arg (call
, 0);
2046 return ptr_deref_may_alias_ref_p_1 (ptr
, ref
);
2048 /* Realloc serves both as allocation point and deallocation point. */
2049 case BUILT_IN_REALLOC
:
2051 tree ptr
= gimple_call_arg (call
, 0);
2052 /* Unix98 specifies that errno is set on allocation failure. */
2053 return ((flag_errno_math
2054 && targetm
.ref_may_alias_errno (ref
))
2055 || ptr_deref_may_alias_ref_p_1 (ptr
, ref
));
2057 case BUILT_IN_GAMMA_R
:
2058 case BUILT_IN_GAMMAF_R
:
2059 case BUILT_IN_GAMMAL_R
:
2060 case BUILT_IN_LGAMMA_R
:
2061 case BUILT_IN_LGAMMAF_R
:
2062 case BUILT_IN_LGAMMAL_R
:
2064 tree out
= gimple_call_arg (call
, 1);
2065 if (ptr_deref_may_alias_ref_p_1 (out
, ref
))
2067 if (flag_errno_math
)
2071 case BUILT_IN_FREXP
:
2072 case BUILT_IN_FREXPF
:
2073 case BUILT_IN_FREXPL
:
2075 case BUILT_IN_MODFF
:
2076 case BUILT_IN_MODFL
:
2078 tree out
= gimple_call_arg (call
, 1);
2079 return ptr_deref_may_alias_ref_p_1 (out
, ref
);
2081 case BUILT_IN_REMQUO
:
2082 case BUILT_IN_REMQUOF
:
2083 case BUILT_IN_REMQUOL
:
2085 tree out
= gimple_call_arg (call
, 2);
2086 if (ptr_deref_may_alias_ref_p_1 (out
, ref
))
2088 if (flag_errno_math
)
2092 case BUILT_IN_SINCOS
:
2093 case BUILT_IN_SINCOSF
:
2094 case BUILT_IN_SINCOSL
:
2096 tree sin
= gimple_call_arg (call
, 1);
2097 tree cos
= gimple_call_arg (call
, 2);
2098 return (ptr_deref_may_alias_ref_p_1 (sin
, ref
)
2099 || ptr_deref_may_alias_ref_p_1 (cos
, ref
));
2101 /* __sync_* builtins and some OpenMP builtins act as threading
2103 #undef DEF_SYNC_BUILTIN
2104 #define DEF_SYNC_BUILTIN(ENUM, NAME, TYPE, ATTRS) case ENUM:
2105 #include "sync-builtins.def"
2106 #undef DEF_SYNC_BUILTIN
2107 case BUILT_IN_GOMP_ATOMIC_START
:
2108 case BUILT_IN_GOMP_ATOMIC_END
:
2109 case BUILT_IN_GOMP_BARRIER
:
2110 case BUILT_IN_GOMP_BARRIER_CANCEL
:
2111 case BUILT_IN_GOMP_TASKWAIT
:
2112 case BUILT_IN_GOMP_TASKGROUP_END
:
2113 case BUILT_IN_GOMP_CRITICAL_START
:
2114 case BUILT_IN_GOMP_CRITICAL_END
:
2115 case BUILT_IN_GOMP_CRITICAL_NAME_START
:
2116 case BUILT_IN_GOMP_CRITICAL_NAME_END
:
2117 case BUILT_IN_GOMP_LOOP_END
:
2118 case BUILT_IN_GOMP_LOOP_END_CANCEL
:
2119 case BUILT_IN_GOMP_ORDERED_START
:
2120 case BUILT_IN_GOMP_ORDERED_END
:
2121 case BUILT_IN_GOMP_SECTIONS_END
:
2122 case BUILT_IN_GOMP_SECTIONS_END_CANCEL
:
2123 case BUILT_IN_GOMP_SINGLE_COPY_START
:
2124 case BUILT_IN_GOMP_SINGLE_COPY_END
:
2127 /* Fallthru to general call handling. */;
2130 /* Check if base is a global static variable that is not written
2132 if (callee
!= NULL_TREE
2133 && TREE_CODE (base
) == VAR_DECL
2134 && TREE_STATIC (base
))
2136 struct cgraph_node
*node
= cgraph_node::get (callee
);
2141 enum availability avail
;
2143 node
= node
->ultimate_alias_target (&avail
);
2144 if (avail
>= AVAIL_AVAILABLE
2145 && (not_written
= ipa_reference_get_not_written_global (node
))
2146 && bitmap_bit_p (not_written
, ipa_reference_var_uid (base
)))
2151 /* Check if the base variable is call-clobbered. */
2153 return pt_solution_includes (gimple_call_clobber_set (call
), base
);
2154 else if ((TREE_CODE (base
) == MEM_REF
2155 || TREE_CODE (base
) == TARGET_MEM_REF
)
2156 && TREE_CODE (TREE_OPERAND (base
, 0)) == SSA_NAME
)
2158 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (TREE_OPERAND (base
, 0));
2162 return pt_solutions_intersect (gimple_call_clobber_set (call
), &pi
->pt
);
2168 /* If the call in statement CALL may clobber the memory reference REF
2169 return true, otherwise return false. */
2172 call_may_clobber_ref_p (gcall
*call
, tree ref
)
2176 ao_ref_init (&r
, ref
);
2177 res
= call_may_clobber_ref_p_1 (call
, &r
);
2179 ++alias_stats
.call_may_clobber_ref_p_may_alias
;
2181 ++alias_stats
.call_may_clobber_ref_p_no_alias
;
2186 /* If the statement STMT may clobber the memory reference REF return true,
2187 otherwise return false. */
2190 stmt_may_clobber_ref_p_1 (gimple
*stmt
, ao_ref
*ref
)
2192 if (is_gimple_call (stmt
))
2194 tree lhs
= gimple_call_lhs (stmt
);
2196 && TREE_CODE (lhs
) != SSA_NAME
)
2199 ao_ref_init (&r
, lhs
);
2200 if (refs_may_alias_p_1 (ref
, &r
, true))
2204 return call_may_clobber_ref_p_1 (as_a
<gcall
*> (stmt
), ref
);
2206 else if (gimple_assign_single_p (stmt
))
2208 tree lhs
= gimple_assign_lhs (stmt
);
2209 if (TREE_CODE (lhs
) != SSA_NAME
)
2212 ao_ref_init (&r
, lhs
);
2213 return refs_may_alias_p_1 (ref
, &r
, true);
2216 else if (gimple_code (stmt
) == GIMPLE_ASM
)
2223 stmt_may_clobber_ref_p (gimple
*stmt
, tree ref
)
2226 ao_ref_init (&r
, ref
);
2227 return stmt_may_clobber_ref_p_1 (stmt
, &r
);
2230 /* If STMT kills the memory reference REF return true, otherwise
2234 stmt_kills_ref_p (gimple
*stmt
, ao_ref
*ref
)
2236 if (!ao_ref_base (ref
))
2239 if (gimple_has_lhs (stmt
)
2240 && TREE_CODE (gimple_get_lhs (stmt
)) != SSA_NAME
2241 /* The assignment is not necessarily carried out if it can throw
2242 and we can catch it in the current function where we could inspect
2244 ??? We only need to care about the RHS throwing. For aggregate
2245 assignments or similar calls and non-call exceptions the LHS
2246 might throw as well. */
2247 && !stmt_can_throw_internal (stmt
))
2249 tree lhs
= gimple_get_lhs (stmt
);
2250 /* If LHS is literally a base of the access we are done. */
2253 tree base
= ref
->ref
;
2254 if (handled_component_p (base
))
2256 tree saved_lhs0
= NULL_TREE
;
2257 if (handled_component_p (lhs
))
2259 saved_lhs0
= TREE_OPERAND (lhs
, 0);
2260 TREE_OPERAND (lhs
, 0) = integer_zero_node
;
2264 /* Just compare the outermost handled component, if
2265 they are equal we have found a possible common
2267 tree saved_base0
= TREE_OPERAND (base
, 0);
2268 TREE_OPERAND (base
, 0) = integer_zero_node
;
2269 bool res
= operand_equal_p (lhs
, base
, 0);
2270 TREE_OPERAND (base
, 0) = saved_base0
;
2273 /* Otherwise drop handled components of the access. */
2276 while (handled_component_p (base
));
2278 TREE_OPERAND (lhs
, 0) = saved_lhs0
;
2280 /* Finally check if the lhs has the same address and size as the
2281 base candidate of the access. */
2283 || (((TYPE_SIZE (TREE_TYPE (lhs
))
2284 == TYPE_SIZE (TREE_TYPE (base
)))
2285 || (TYPE_SIZE (TREE_TYPE (lhs
))
2286 && TYPE_SIZE (TREE_TYPE (base
))
2287 && operand_equal_p (TYPE_SIZE (TREE_TYPE (lhs
)),
2288 TYPE_SIZE (TREE_TYPE (base
)), 0)))
2289 && operand_equal_p (lhs
, base
, OEP_ADDRESS_OF
)))
2293 /* Now look for non-literal equal bases with the restriction of
2294 handling constant offset and size. */
2295 /* For a must-alias check we need to be able to constrain
2296 the access properly. */
2297 if (ref
->max_size
== -1)
2299 HOST_WIDE_INT size
, offset
, max_size
, ref_offset
= ref
->offset
;
2302 = get_ref_base_and_extent (lhs
, &offset
, &size
, &max_size
, &reverse
);
2303 /* We can get MEM[symbol: sZ, index: D.8862_1] here,
2304 so base == ref->base does not always hold. */
2305 if (base
!= ref
->base
)
2307 /* If both base and ref->base are MEM_REFs, only compare the
2308 first operand, and if the second operand isn't equal constant,
2309 try to add the offsets into offset and ref_offset. */
2310 if (TREE_CODE (base
) == MEM_REF
&& TREE_CODE (ref
->base
) == MEM_REF
2311 && TREE_OPERAND (base
, 0) == TREE_OPERAND (ref
->base
, 0))
2313 if (!tree_int_cst_equal (TREE_OPERAND (base
, 1),
2314 TREE_OPERAND (ref
->base
, 1)))
2316 offset_int off1
= mem_ref_offset (base
);
2317 off1
= wi::lshift (off1
, LOG2_BITS_PER_UNIT
);
2319 offset_int off2
= mem_ref_offset (ref
->base
);
2320 off2
= wi::lshift (off2
, LOG2_BITS_PER_UNIT
);
2322 if (wi::fits_shwi_p (off1
) && wi::fits_shwi_p (off2
))
2324 offset
= off1
.to_shwi ();
2325 ref_offset
= off2
.to_shwi ();
2334 /* For a must-alias check we need to be able to constrain
2335 the access properly. */
2336 if (size
!= -1 && size
== max_size
)
2338 if (offset
<= ref_offset
2339 && offset
+ size
>= ref_offset
+ ref
->max_size
)
2344 if (is_gimple_call (stmt
))
2346 tree callee
= gimple_call_fndecl (stmt
);
2347 if (callee
!= NULL_TREE
2348 && gimple_call_builtin_p (stmt
, BUILT_IN_NORMAL
))
2349 switch (DECL_FUNCTION_CODE (callee
))
2353 tree ptr
= gimple_call_arg (stmt
, 0);
2354 tree base
= ao_ref_base (ref
);
2355 if (base
&& TREE_CODE (base
) == MEM_REF
2356 && TREE_OPERAND (base
, 0) == ptr
)
2361 case BUILT_IN_MEMCPY
:
2362 case BUILT_IN_MEMPCPY
:
2363 case BUILT_IN_MEMMOVE
:
2364 case BUILT_IN_MEMSET
:
2365 case BUILT_IN_MEMCPY_CHK
:
2366 case BUILT_IN_MEMPCPY_CHK
:
2367 case BUILT_IN_MEMMOVE_CHK
:
2368 case BUILT_IN_MEMSET_CHK
:
2370 /* For a must-alias check we need to be able to constrain
2371 the access properly. */
2372 if (ref
->max_size
== -1)
2374 tree dest
= gimple_call_arg (stmt
, 0);
2375 tree len
= gimple_call_arg (stmt
, 2);
2376 if (!tree_fits_shwi_p (len
))
2378 tree rbase
= ref
->base
;
2379 offset_int roffset
= ref
->offset
;
2381 ao_ref_init_from_ptr_and_size (&dref
, dest
, len
);
2382 tree base
= ao_ref_base (&dref
);
2383 offset_int offset
= dref
.offset
;
2384 if (!base
|| dref
.size
== -1)
2386 if (TREE_CODE (base
) == MEM_REF
)
2388 if (TREE_CODE (rbase
) != MEM_REF
)
2390 // Compare pointers.
2391 offset
+= wi::lshift (mem_ref_offset (base
),
2392 LOG2_BITS_PER_UNIT
);
2393 roffset
+= wi::lshift (mem_ref_offset (rbase
),
2394 LOG2_BITS_PER_UNIT
);
2395 base
= TREE_OPERAND (base
, 0);
2396 rbase
= TREE_OPERAND (rbase
, 0);
2399 && wi::les_p (offset
, roffset
)
2400 && wi::les_p (roffset
+ ref
->max_size
,
2401 offset
+ wi::lshift (wi::to_offset (len
),
2402 LOG2_BITS_PER_UNIT
)))
2407 case BUILT_IN_VA_END
:
2409 tree ptr
= gimple_call_arg (stmt
, 0);
2410 if (TREE_CODE (ptr
) == ADDR_EXPR
)
2412 tree base
= ao_ref_base (ref
);
2413 if (TREE_OPERAND (ptr
, 0) == base
)
2426 stmt_kills_ref_p (gimple
*stmt
, tree ref
)
2429 ao_ref_init (&r
, ref
);
2430 return stmt_kills_ref_p (stmt
, &r
);
2434 /* Walk the virtual use-def chain of VUSE until hitting the virtual operand
2435 TARGET or a statement clobbering the memory reference REF in which
2436 case false is returned. The walk starts with VUSE, one argument of PHI. */
2439 maybe_skip_until (gimple
*phi
, tree target
, ao_ref
*ref
,
2440 tree vuse
, unsigned int *cnt
, bitmap
*visited
,
2441 bool abort_on_visited
,
2442 void *(*translate
)(ao_ref
*, tree
, void *, bool *),
2445 basic_block bb
= gimple_bb (phi
);
2448 *visited
= BITMAP_ALLOC (NULL
);
2450 bitmap_set_bit (*visited
, SSA_NAME_VERSION (PHI_RESULT (phi
)));
2452 /* Walk until we hit the target. */
2453 while (vuse
!= target
)
2455 gimple
*def_stmt
= SSA_NAME_DEF_STMT (vuse
);
2456 /* Recurse for PHI nodes. */
2457 if (gimple_code (def_stmt
) == GIMPLE_PHI
)
2459 /* An already visited PHI node ends the walk successfully. */
2460 if (bitmap_bit_p (*visited
, SSA_NAME_VERSION (PHI_RESULT (def_stmt
))))
2461 return !abort_on_visited
;
2462 vuse
= get_continuation_for_phi (def_stmt
, ref
, cnt
,
2463 visited
, abort_on_visited
,
2469 else if (gimple_nop_p (def_stmt
))
2473 /* A clobbering statement or the end of the IL ends it failing. */
2475 if (stmt_may_clobber_ref_p_1 (def_stmt
, ref
))
2477 bool disambiguate_only
= true;
2479 && (*translate
) (ref
, vuse
, data
, &disambiguate_only
) == NULL
)
2485 /* If we reach a new basic-block see if we already skipped it
2486 in a previous walk that ended successfully. */
2487 if (gimple_bb (def_stmt
) != bb
)
2489 if (!bitmap_set_bit (*visited
, SSA_NAME_VERSION (vuse
)))
2490 return !abort_on_visited
;
2491 bb
= gimple_bb (def_stmt
);
2493 vuse
= gimple_vuse (def_stmt
);
2498 /* For two PHI arguments ARG0 and ARG1 try to skip non-aliasing code
2499 until we hit the phi argument definition that dominates the other one.
2500 Return that, or NULL_TREE if there is no such definition. */
2503 get_continuation_for_phi_1 (gimple
*phi
, tree arg0
, tree arg1
,
2504 ao_ref
*ref
, unsigned int *cnt
,
2505 bitmap
*visited
, bool abort_on_visited
,
2506 void *(*translate
)(ao_ref
*, tree
, void *, bool *),
2509 gimple
*def0
= SSA_NAME_DEF_STMT (arg0
);
2510 gimple
*def1
= SSA_NAME_DEF_STMT (arg1
);
2515 else if (gimple_nop_p (def0
)
2516 || (!gimple_nop_p (def1
)
2517 && dominated_by_p (CDI_DOMINATORS
,
2518 gimple_bb (def1
), gimple_bb (def0
))))
2520 if (maybe_skip_until (phi
, arg0
, ref
, arg1
, cnt
,
2521 visited
, abort_on_visited
, translate
, data
))
2524 else if (gimple_nop_p (def1
)
2525 || dominated_by_p (CDI_DOMINATORS
,
2526 gimple_bb (def0
), gimple_bb (def1
)))
2528 if (maybe_skip_until (phi
, arg1
, ref
, arg0
, cnt
,
2529 visited
, abort_on_visited
, translate
, data
))
2532 /* Special case of a diamond:
2534 goto (cond) ? L1 : L2
2535 L1: store1 = ... #MEM_2 = vuse(MEM_1)
2537 L2: store2 = ... #MEM_3 = vuse(MEM_1)
2538 L3: MEM_4 = PHI<MEM_2, MEM_3>
2539 We were called with the PHI at L3, MEM_2 and MEM_3 don't
2540 dominate each other, but still we can easily skip this PHI node
2541 if we recognize that the vuse MEM operand is the same for both,
2542 and that we can skip both statements (they don't clobber us).
2543 This is still linear. Don't use maybe_skip_until, that might
2544 potentially be slow. */
2545 else if ((common_vuse
= gimple_vuse (def0
))
2546 && common_vuse
== gimple_vuse (def1
))
2548 bool disambiguate_only
= true;
2550 if ((!stmt_may_clobber_ref_p_1 (def0
, ref
)
2552 && (*translate
) (ref
, arg0
, data
, &disambiguate_only
) == NULL
))
2553 && (!stmt_may_clobber_ref_p_1 (def1
, ref
)
2555 && (*translate
) (ref
, arg1
, data
, &disambiguate_only
) == NULL
)))
2563 /* Starting from a PHI node for the virtual operand of the memory reference
2564 REF find a continuation virtual operand that allows to continue walking
2565 statements dominating PHI skipping only statements that cannot possibly
2566 clobber REF. Increments *CNT for each alias disambiguation done.
2567 Returns NULL_TREE if no suitable virtual operand can be found. */
2570 get_continuation_for_phi (gimple
*phi
, ao_ref
*ref
,
2571 unsigned int *cnt
, bitmap
*visited
,
2572 bool abort_on_visited
,
2573 void *(*translate
)(ao_ref
*, tree
, void *, bool *),
2576 unsigned nargs
= gimple_phi_num_args (phi
);
2578 /* Through a single-argument PHI we can simply look through. */
2580 return PHI_ARG_DEF (phi
, 0);
2582 /* For two or more arguments try to pairwise skip non-aliasing code
2583 until we hit the phi argument definition that dominates the other one. */
2584 else if (nargs
>= 2)
2589 /* Find a candidate for the virtual operand which definition
2590 dominates those of all others. */
2591 arg0
= PHI_ARG_DEF (phi
, 0);
2592 if (!SSA_NAME_IS_DEFAULT_DEF (arg0
))
2593 for (i
= 1; i
< nargs
; ++i
)
2595 arg1
= PHI_ARG_DEF (phi
, i
);
2596 if (SSA_NAME_IS_DEFAULT_DEF (arg1
))
2601 if (dominated_by_p (CDI_DOMINATORS
,
2602 gimple_bb (SSA_NAME_DEF_STMT (arg0
)),
2603 gimple_bb (SSA_NAME_DEF_STMT (arg1
))))
2607 /* Then pairwise reduce against the found candidate. */
2608 for (i
= 0; i
< nargs
; ++i
)
2610 arg1
= PHI_ARG_DEF (phi
, i
);
2611 arg0
= get_continuation_for_phi_1 (phi
, arg0
, arg1
, ref
,
2612 cnt
, visited
, abort_on_visited
,
2624 /* Based on the memory reference REF and its virtual use VUSE call
2625 WALKER for each virtual use that is equivalent to VUSE, including VUSE
2626 itself. That is, for each virtual use for which its defining statement
2627 does not clobber REF.
2629 WALKER is called with REF, the current virtual use and DATA. If
2630 WALKER returns non-NULL the walk stops and its result is returned.
2631 At the end of a non-successful walk NULL is returned.
2633 TRANSLATE if non-NULL is called with a pointer to REF, the virtual
2634 use which definition is a statement that may clobber REF and DATA.
2635 If TRANSLATE returns (void *)-1 the walk stops and NULL is returned.
2636 If TRANSLATE returns non-NULL the walk stops and its result is returned.
2637 If TRANSLATE returns NULL the walk continues and TRANSLATE is supposed
2638 to adjust REF and *DATA to make that valid.
2640 VALUEIZE if non-NULL is called with the next VUSE that is considered
2641 and return value is substituted for that. This can be used to
2642 implement optimistic value-numbering for example. Note that the
2643 VUSE argument is assumed to be valueized already.
2645 TODO: Cache the vector of equivalent vuses per ref, vuse pair. */
2648 walk_non_aliased_vuses (ao_ref
*ref
, tree vuse
,
2649 void *(*walker
)(ao_ref
*, tree
, unsigned int, void *),
2650 void *(*translate
)(ao_ref
*, tree
, void *, bool *),
2651 tree (*valueize
)(tree
),
2654 bitmap visited
= NULL
;
2656 unsigned int cnt
= 0;
2657 bool translated
= false;
2659 timevar_push (TV_ALIAS_STMT_WALK
);
2665 /* ??? Do we want to account this to TV_ALIAS_STMT_WALK? */
2666 res
= (*walker
) (ref
, vuse
, cnt
, data
);
2668 if (res
== (void *)-1)
2673 /* Lookup succeeded. */
2674 else if (res
!= NULL
)
2678 vuse
= valueize (vuse
);
2679 def_stmt
= SSA_NAME_DEF_STMT (vuse
);
2680 if (gimple_nop_p (def_stmt
))
2682 else if (gimple_code (def_stmt
) == GIMPLE_PHI
)
2683 vuse
= get_continuation_for_phi (def_stmt
, ref
, &cnt
,
2684 &visited
, translated
, translate
, data
);
2688 if (stmt_may_clobber_ref_p_1 (def_stmt
, ref
))
2692 bool disambiguate_only
= false;
2693 res
= (*translate
) (ref
, vuse
, data
, &disambiguate_only
);
2694 /* Failed lookup and translation. */
2695 if (res
== (void *)-1)
2700 /* Lookup succeeded. */
2701 else if (res
!= NULL
)
2703 /* Translation succeeded, continue walking. */
2704 translated
= translated
|| !disambiguate_only
;
2706 vuse
= gimple_vuse (def_stmt
);
2712 BITMAP_FREE (visited
);
2714 timevar_pop (TV_ALIAS_STMT_WALK
);
2720 /* Based on the memory reference REF call WALKER for each vdef which
2721 defining statement may clobber REF, starting with VDEF. If REF
2722 is NULL_TREE, each defining statement is visited.
2724 WALKER is called with REF, the current vdef and DATA. If WALKER
2725 returns true the walk is stopped, otherwise it continues.
2727 If function entry is reached, FUNCTION_ENTRY_REACHED is set to true.
2728 The pointer may be NULL and then we do not track this information.
2730 At PHI nodes walk_aliased_vdefs forks into one walk for reach
2731 PHI argument (but only one walk continues on merge points), the
2732 return value is true if any of the walks was successful.
2734 The function returns the number of statements walked. */
2737 walk_aliased_vdefs_1 (ao_ref
*ref
, tree vdef
,
2738 bool (*walker
)(ao_ref
*, tree
, void *), void *data
,
2739 bitmap
*visited
, unsigned int cnt
,
2740 bool *function_entry_reached
)
2744 gimple
*def_stmt
= SSA_NAME_DEF_STMT (vdef
);
2747 && !bitmap_set_bit (*visited
, SSA_NAME_VERSION (vdef
)))
2750 if (gimple_nop_p (def_stmt
))
2752 if (function_entry_reached
)
2753 *function_entry_reached
= true;
2756 else if (gimple_code (def_stmt
) == GIMPLE_PHI
)
2760 *visited
= BITMAP_ALLOC (NULL
);
2761 for (i
= 0; i
< gimple_phi_num_args (def_stmt
); ++i
)
2762 cnt
+= walk_aliased_vdefs_1 (ref
, gimple_phi_arg_def (def_stmt
, i
),
2763 walker
, data
, visited
, 0,
2764 function_entry_reached
);
2768 /* ??? Do we want to account this to TV_ALIAS_STMT_WALK? */
2771 || stmt_may_clobber_ref_p_1 (def_stmt
, ref
))
2772 && (*walker
) (ref
, vdef
, data
))
2775 vdef
= gimple_vuse (def_stmt
);
2781 walk_aliased_vdefs (ao_ref
*ref
, tree vdef
,
2782 bool (*walker
)(ao_ref
*, tree
, void *), void *data
,
2784 bool *function_entry_reached
)
2786 bitmap local_visited
= NULL
;
2789 timevar_push (TV_ALIAS_STMT_WALK
);
2791 if (function_entry_reached
)
2792 *function_entry_reached
= false;
2794 ret
= walk_aliased_vdefs_1 (ref
, vdef
, walker
, data
,
2795 visited
? visited
: &local_visited
, 0,
2796 function_entry_reached
);
2798 BITMAP_FREE (local_visited
);
2800 timevar_pop (TV_ALIAS_STMT_WALK
);