1 /* Alias analysis for trees.
2 Copyright (C) 2004-2016 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);
197 return compare_base_decls (base
, decl
) != 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 true if PTR1 and PTR2 compare unequal because of points-to. */
327 ptrs_compare_unequal (tree ptr1
, tree ptr2
)
329 /* First resolve the pointers down to a SSA name pointer base or
330 a VAR_DECL, PARM_DECL or RESULT_DECL. This explicitely does
331 not yet try to handle LABEL_DECLs, FUNCTION_DECLs, CONST_DECLs
332 or STRING_CSTs which needs points-to adjustments to track them
333 in the points-to sets. */
334 tree obj1
= NULL_TREE
;
335 tree obj2
= NULL_TREE
;
336 if (TREE_CODE (ptr1
) == ADDR_EXPR
)
338 tree tem
= get_base_address (TREE_OPERAND (ptr1
, 0));
341 if (TREE_CODE (tem
) == VAR_DECL
342 || TREE_CODE (tem
) == PARM_DECL
343 || TREE_CODE (tem
) == RESULT_DECL
)
345 else if (TREE_CODE (tem
) == MEM_REF
)
346 ptr1
= TREE_OPERAND (tem
, 0);
348 if (TREE_CODE (ptr2
) == ADDR_EXPR
)
350 tree tem
= get_base_address (TREE_OPERAND (ptr2
, 0));
353 if (TREE_CODE (tem
) == VAR_DECL
354 || TREE_CODE (tem
) == PARM_DECL
355 || TREE_CODE (tem
) == RESULT_DECL
)
357 else if (TREE_CODE (tem
) == MEM_REF
)
358 ptr2
= TREE_OPERAND (tem
, 0);
362 /* Other code handles this correctly, no need to duplicate it here. */;
363 else if (obj1
&& TREE_CODE (ptr2
) == SSA_NAME
)
365 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (ptr2
);
368 return !pt_solution_includes (&pi
->pt
, obj1
);
370 else if (TREE_CODE (ptr1
) == SSA_NAME
&& obj2
)
372 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (ptr1
);
375 return !pt_solution_includes (&pi
->pt
, obj2
);
378 /* ??? We'd like to handle ptr1 != NULL and ptr1 != ptr2
379 but those require pt.null to be conservatively correct. */
384 /* Returns whether reference REF to BASE may refer to global memory. */
387 ref_may_alias_global_p_1 (tree base
)
390 return is_global_var (base
);
391 else if (TREE_CODE (base
) == MEM_REF
392 || TREE_CODE (base
) == TARGET_MEM_REF
)
393 return ptr_deref_may_alias_global_p (TREE_OPERAND (base
, 0));
398 ref_may_alias_global_p (ao_ref
*ref
)
400 tree base
= ao_ref_base (ref
);
401 return ref_may_alias_global_p_1 (base
);
405 ref_may_alias_global_p (tree ref
)
407 tree base
= get_base_address (ref
);
408 return ref_may_alias_global_p_1 (base
);
411 /* Return true whether STMT may clobber global memory. */
414 stmt_may_clobber_global_p (gimple
*stmt
)
418 if (!gimple_vdef (stmt
))
421 /* ??? We can ask the oracle whether an artificial pointer
422 dereference with a pointer with points-to information covering
423 all global memory (what about non-address taken memory?) maybe
424 clobbered by this call. As there is at the moment no convenient
425 way of doing that without generating garbage do some manual
427 ??? We could make a NULL ao_ref argument to the various
428 predicates special, meaning any global memory. */
430 switch (gimple_code (stmt
))
433 lhs
= gimple_assign_lhs (stmt
);
434 return (TREE_CODE (lhs
) != SSA_NAME
435 && ref_may_alias_global_p (lhs
));
444 /* Dump alias information on FILE. */
447 dump_alias_info (FILE *file
)
451 = lang_hooks
.decl_printable_name (current_function_decl
, 2);
454 fprintf (file
, "\n\nAlias information for %s\n\n", funcname
);
456 fprintf (file
, "Aliased symbols\n\n");
458 FOR_EACH_LOCAL_DECL (cfun
, i
, var
)
460 if (may_be_aliased (var
))
461 dump_variable (file
, var
);
464 fprintf (file
, "\nCall clobber information\n");
466 fprintf (file
, "\nESCAPED");
467 dump_points_to_solution (file
, &cfun
->gimple_df
->escaped
);
469 fprintf (file
, "\n\nFlow-insensitive points-to information\n\n");
471 for (i
= 1; i
< num_ssa_names
; i
++)
473 tree ptr
= ssa_name (i
);
474 struct ptr_info_def
*pi
;
477 || !POINTER_TYPE_P (TREE_TYPE (ptr
))
478 || SSA_NAME_IN_FREE_LIST (ptr
))
481 pi
= SSA_NAME_PTR_INFO (ptr
);
483 dump_points_to_info_for (file
, ptr
);
486 fprintf (file
, "\n");
490 /* Dump alias information on stderr. */
493 debug_alias_info (void)
495 dump_alias_info (stderr
);
499 /* Dump the points-to set *PT into FILE. */
502 dump_points_to_solution (FILE *file
, struct pt_solution
*pt
)
505 fprintf (file
, ", points-to anything");
508 fprintf (file
, ", points-to non-local");
511 fprintf (file
, ", points-to escaped");
514 fprintf (file
, ", points-to unit escaped");
517 fprintf (file
, ", points-to NULL");
521 fprintf (file
, ", points-to vars: ");
522 dump_decl_set (file
, pt
->vars
);
523 if (pt
->vars_contains_nonlocal
524 && pt
->vars_contains_escaped_heap
)
525 fprintf (file
, " (nonlocal, escaped heap)");
526 else if (pt
->vars_contains_nonlocal
527 && pt
->vars_contains_escaped
)
528 fprintf (file
, " (nonlocal, escaped)");
529 else if (pt
->vars_contains_nonlocal
)
530 fprintf (file
, " (nonlocal)");
531 else if (pt
->vars_contains_escaped_heap
)
532 fprintf (file
, " (escaped heap)");
533 else if (pt
->vars_contains_escaped
)
534 fprintf (file
, " (escaped)");
539 /* Unified dump function for pt_solution. */
542 debug (pt_solution
&ref
)
544 dump_points_to_solution (stderr
, &ref
);
548 debug (pt_solution
*ptr
)
553 fprintf (stderr
, "<nil>\n");
557 /* Dump points-to information for SSA_NAME PTR into FILE. */
560 dump_points_to_info_for (FILE *file
, tree ptr
)
562 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (ptr
);
564 print_generic_expr (file
, ptr
, dump_flags
);
567 dump_points_to_solution (file
, &pi
->pt
);
569 fprintf (file
, ", points-to anything");
571 fprintf (file
, "\n");
575 /* Dump points-to information for VAR into stderr. */
578 debug_points_to_info_for (tree var
)
580 dump_points_to_info_for (stderr
, var
);
584 /* Initializes the alias-oracle reference representation *R from REF. */
587 ao_ref_init (ao_ref
*r
, tree ref
)
594 r
->ref_alias_set
= -1;
595 r
->base_alias_set
= -1;
596 r
->volatile_p
= ref
? TREE_THIS_VOLATILE (ref
) : false;
599 /* Returns the base object of the memory reference *REF. */
602 ao_ref_base (ao_ref
*ref
)
608 ref
->base
= get_ref_base_and_extent (ref
->ref
, &ref
->offset
, &ref
->size
,
609 &ref
->max_size
, &reverse
);
613 /* Returns the base object alias set of the memory reference *REF. */
616 ao_ref_base_alias_set (ao_ref
*ref
)
619 if (ref
->base_alias_set
!= -1)
620 return ref
->base_alias_set
;
624 while (handled_component_p (base_ref
))
625 base_ref
= TREE_OPERAND (base_ref
, 0);
626 ref
->base_alias_set
= get_alias_set (base_ref
);
627 return ref
->base_alias_set
;
630 /* Returns the reference alias set of the memory reference *REF. */
633 ao_ref_alias_set (ao_ref
*ref
)
635 if (ref
->ref_alias_set
!= -1)
636 return ref
->ref_alias_set
;
637 ref
->ref_alias_set
= get_alias_set (ref
->ref
);
638 return ref
->ref_alias_set
;
641 /* Init an alias-oracle reference representation from a gimple pointer
642 PTR and a gimple size SIZE in bytes. If SIZE is NULL_TREE then the
643 size is assumed to be unknown. The access is assumed to be only
644 to or after of the pointer target, not before it. */
647 ao_ref_init_from_ptr_and_size (ao_ref
*ref
, tree ptr
, tree size
)
649 HOST_WIDE_INT t
, size_hwi
, extra_offset
= 0;
650 ref
->ref
= NULL_TREE
;
651 if (TREE_CODE (ptr
) == SSA_NAME
)
653 gimple
*stmt
= SSA_NAME_DEF_STMT (ptr
);
654 if (gimple_assign_single_p (stmt
)
655 && gimple_assign_rhs_code (stmt
) == ADDR_EXPR
)
656 ptr
= gimple_assign_rhs1 (stmt
);
657 else if (is_gimple_assign (stmt
)
658 && gimple_assign_rhs_code (stmt
) == POINTER_PLUS_EXPR
659 && TREE_CODE (gimple_assign_rhs2 (stmt
)) == INTEGER_CST
)
661 ptr
= gimple_assign_rhs1 (stmt
);
662 extra_offset
= BITS_PER_UNIT
663 * int_cst_value (gimple_assign_rhs2 (stmt
));
667 if (TREE_CODE (ptr
) == ADDR_EXPR
)
669 ref
->base
= get_addr_base_and_unit_offset (TREE_OPERAND (ptr
, 0), &t
);
671 ref
->offset
= BITS_PER_UNIT
* t
;
676 ref
->base
= get_base_address (TREE_OPERAND (ptr
, 0));
681 ref
->base
= build2 (MEM_REF
, char_type_node
,
682 ptr
, null_pointer_node
);
685 ref
->offset
+= extra_offset
;
687 && tree_fits_shwi_p (size
)
688 && (size_hwi
= tree_to_shwi (size
)) <= HOST_WIDE_INT_MAX
/ BITS_PER_UNIT
)
689 ref
->max_size
= ref
->size
= size_hwi
* BITS_PER_UNIT
;
691 ref
->max_size
= ref
->size
= -1;
692 ref
->ref_alias_set
= 0;
693 ref
->base_alias_set
= 0;
694 ref
->volatile_p
= false;
697 /* Return 1 if TYPE1 and TYPE2 are to be considered equivalent for the
698 purpose of TBAA. Return 0 if they are distinct and -1 if we cannot
702 same_type_for_tbaa (tree type1
, tree type2
)
704 type1
= TYPE_MAIN_VARIANT (type1
);
705 type2
= TYPE_MAIN_VARIANT (type2
);
707 /* If we would have to do structural comparison bail out. */
708 if (TYPE_STRUCTURAL_EQUALITY_P (type1
)
709 || TYPE_STRUCTURAL_EQUALITY_P (type2
))
712 /* Compare the canonical types. */
713 if (TYPE_CANONICAL (type1
) == TYPE_CANONICAL (type2
))
716 /* ??? Array types are not properly unified in all cases as we have
717 spurious changes in the index types for example. Removing this
718 causes all sorts of problems with the Fortran frontend. */
719 if (TREE_CODE (type1
) == ARRAY_TYPE
720 && TREE_CODE (type2
) == ARRAY_TYPE
)
723 /* ??? In Ada, an lvalue of an unconstrained type can be used to access an
724 object of one of its constrained subtypes, e.g. when a function with an
725 unconstrained parameter passed by reference is called on an object and
726 inlined. But, even in the case of a fixed size, type and subtypes are
727 not equivalent enough as to share the same TYPE_CANONICAL, since this
728 would mean that conversions between them are useless, whereas they are
729 not (e.g. type and subtypes can have different modes). So, in the end,
730 they are only guaranteed to have the same alias set. */
731 if (get_alias_set (type1
) == get_alias_set (type2
))
734 /* The types are known to be not equal. */
738 /* Determine if the two component references REF1 and REF2 which are
739 based on access types TYPE1 and TYPE2 and of which at least one is based
740 on an indirect reference may alias. REF2 is the only one that can
741 be a decl in which case REF2_IS_DECL is true.
742 REF1_ALIAS_SET, BASE1_ALIAS_SET, REF2_ALIAS_SET and BASE2_ALIAS_SET
743 are the respective alias sets. */
746 aliasing_component_refs_p (tree ref1
,
747 alias_set_type ref1_alias_set
,
748 alias_set_type base1_alias_set
,
749 HOST_WIDE_INT offset1
, HOST_WIDE_INT max_size1
,
751 alias_set_type ref2_alias_set
,
752 alias_set_type base2_alias_set
,
753 HOST_WIDE_INT offset2
, HOST_WIDE_INT max_size2
,
756 /* If one reference is a component references through pointers try to find a
757 common base and apply offset based disambiguation. This handles
759 struct A { int i; int j; } *q;
760 struct B { struct A a; int k; } *p;
761 disambiguating q->i and p->a.j. */
767 /* Choose bases and base types to search for. */
769 while (handled_component_p (base1
))
770 base1
= TREE_OPERAND (base1
, 0);
771 type1
= TREE_TYPE (base1
);
773 while (handled_component_p (base2
))
774 base2
= TREE_OPERAND (base2
, 0);
775 type2
= TREE_TYPE (base2
);
777 /* Now search for the type1 in the access path of ref2. This
778 would be a common base for doing offset based disambiguation on. */
780 while (handled_component_p (*refp
)
781 && same_type_for_tbaa (TREE_TYPE (*refp
), type1
) == 0)
782 refp
= &TREE_OPERAND (*refp
, 0);
783 same_p
= same_type_for_tbaa (TREE_TYPE (*refp
), type1
);
784 /* If we couldn't compare types we have to bail out. */
787 else if (same_p
== 1)
789 HOST_WIDE_INT offadj
, sztmp
, msztmp
;
791 get_ref_base_and_extent (*refp
, &offadj
, &sztmp
, &msztmp
, &reverse
);
793 get_ref_base_and_extent (base1
, &offadj
, &sztmp
, &msztmp
, &reverse
);
795 return ranges_overlap_p (offset1
, max_size1
, offset2
, max_size2
);
797 /* If we didn't find a common base, try the other way around. */
799 while (handled_component_p (*refp
)
800 && same_type_for_tbaa (TREE_TYPE (*refp
), type2
) == 0)
801 refp
= &TREE_OPERAND (*refp
, 0);
802 same_p
= same_type_for_tbaa (TREE_TYPE (*refp
), type2
);
803 /* If we couldn't compare types we have to bail out. */
806 else if (same_p
== 1)
808 HOST_WIDE_INT offadj
, sztmp
, msztmp
;
810 get_ref_base_and_extent (*refp
, &offadj
, &sztmp
, &msztmp
, &reverse
);
812 get_ref_base_and_extent (base2
, &offadj
, &sztmp
, &msztmp
, &reverse
);
814 return ranges_overlap_p (offset1
, max_size1
, offset2
, max_size2
);
817 /* If we have two type access paths B1.path1 and B2.path2 they may
818 only alias if either B1 is in B2.path2 or B2 is in B1.path1.
819 But we can still have a path that goes B1.path1...B2.path2 with
820 a part that we do not see. So we can only disambiguate now
821 if there is no B2 in the tail of path1 and no B1 on the
823 if (base1_alias_set
== ref2_alias_set
824 || alias_set_subset_of (base1_alias_set
, ref2_alias_set
))
826 /* If this is ptr vs. decl then we know there is no ptr ... decl path. */
828 return (base2_alias_set
== ref1_alias_set
829 || alias_set_subset_of (base2_alias_set
, ref1_alias_set
));
833 /* Return true if we can determine that component references REF1 and REF2,
834 that are within a common DECL, cannot overlap. */
837 nonoverlapping_component_refs_of_decl_p (tree ref1
, tree ref2
)
839 auto_vec
<tree
, 16> component_refs1
;
840 auto_vec
<tree
, 16> component_refs2
;
842 /* Create the stack of handled components for REF1. */
843 while (handled_component_p (ref1
))
845 component_refs1
.safe_push (ref1
);
846 ref1
= TREE_OPERAND (ref1
, 0);
848 if (TREE_CODE (ref1
) == MEM_REF
)
850 if (!integer_zerop (TREE_OPERAND (ref1
, 1)))
852 ref1
= TREE_OPERAND (TREE_OPERAND (ref1
, 0), 0);
855 /* Create the stack of handled components for REF2. */
856 while (handled_component_p (ref2
))
858 component_refs2
.safe_push (ref2
);
859 ref2
= TREE_OPERAND (ref2
, 0);
861 if (TREE_CODE (ref2
) == MEM_REF
)
863 if (!integer_zerop (TREE_OPERAND (ref2
, 1)))
865 ref2
= TREE_OPERAND (TREE_OPERAND (ref2
, 0), 0);
868 /* Bases must be either same or uncomparable. */
869 gcc_checking_assert (ref1
== ref2
870 || (DECL_P (ref1
) && DECL_P (ref2
)
871 && compare_base_decls (ref1
, ref2
) != 0));
873 /* Pop the stacks in parallel and examine the COMPONENT_REFs of the same
874 rank. This is sufficient because we start from the same DECL and you
875 cannot reference several fields at a time with COMPONENT_REFs (unlike
876 with ARRAY_RANGE_REFs for arrays) so you always need the same number
877 of them to access a sub-component, unless you're in a union, in which
878 case the return value will precisely be false. */
883 if (component_refs1
.is_empty ())
885 ref1
= component_refs1
.pop ();
887 while (!RECORD_OR_UNION_TYPE_P (TREE_TYPE (TREE_OPERAND (ref1
, 0))));
891 if (component_refs2
.is_empty ())
893 ref2
= component_refs2
.pop ();
895 while (!RECORD_OR_UNION_TYPE_P (TREE_TYPE (TREE_OPERAND (ref2
, 0))));
897 /* Beware of BIT_FIELD_REF. */
898 if (TREE_CODE (ref1
) != COMPONENT_REF
899 || TREE_CODE (ref2
) != COMPONENT_REF
)
902 tree field1
= TREE_OPERAND (ref1
, 1);
903 tree field2
= TREE_OPERAND (ref2
, 1);
905 /* ??? We cannot simply use the type of operand #0 of the refs here
906 as the Fortran compiler smuggles type punning into COMPONENT_REFs
907 for common blocks instead of using unions like everyone else. */
908 tree type1
= DECL_CONTEXT (field1
);
909 tree type2
= DECL_CONTEXT (field2
);
911 /* We cannot disambiguate fields in a union or qualified union. */
912 if (type1
!= type2
|| TREE_CODE (type1
) != RECORD_TYPE
)
915 /* Different fields of the same record type cannot overlap.
916 ??? Bitfields can overlap at RTL level so punt on them. */
917 if (field1
!= field2
)
919 component_refs1
.release ();
920 component_refs2
.release ();
921 return !(DECL_BIT_FIELD (field1
) && DECL_BIT_FIELD (field2
));
926 component_refs1
.release ();
927 component_refs2
.release ();
931 /* qsort compare function to sort FIELD_DECLs after their
932 DECL_FIELD_CONTEXT TYPE_UID. */
935 ncr_compar (const void *field1_
, const void *field2_
)
937 const_tree field1
= *(const_tree
*) const_cast <void *>(field1_
);
938 const_tree field2
= *(const_tree
*) const_cast <void *>(field2_
);
939 unsigned int uid1
= TYPE_UID (DECL_FIELD_CONTEXT (field1
));
940 unsigned int uid2
= TYPE_UID (DECL_FIELD_CONTEXT (field2
));
943 else if (uid1
> uid2
)
948 /* Return true if we can determine that the fields referenced cannot
949 overlap for any pair of objects. */
952 nonoverlapping_component_refs_p (const_tree x
, const_tree y
)
954 if (!flag_strict_aliasing
956 || TREE_CODE (x
) != COMPONENT_REF
957 || TREE_CODE (y
) != COMPONENT_REF
)
960 auto_vec
<const_tree
, 16> fieldsx
;
961 while (TREE_CODE (x
) == COMPONENT_REF
)
963 tree field
= TREE_OPERAND (x
, 1);
964 tree type
= DECL_FIELD_CONTEXT (field
);
965 if (TREE_CODE (type
) == RECORD_TYPE
)
966 fieldsx
.safe_push (field
);
967 x
= TREE_OPERAND (x
, 0);
969 if (fieldsx
.length () == 0)
971 auto_vec
<const_tree
, 16> fieldsy
;
972 while (TREE_CODE (y
) == COMPONENT_REF
)
974 tree field
= TREE_OPERAND (y
, 1);
975 tree type
= DECL_FIELD_CONTEXT (field
);
976 if (TREE_CODE (type
) == RECORD_TYPE
)
977 fieldsy
.safe_push (TREE_OPERAND (y
, 1));
978 y
= TREE_OPERAND (y
, 0);
980 if (fieldsy
.length () == 0)
983 /* Most common case first. */
984 if (fieldsx
.length () == 1
985 && fieldsy
.length () == 1)
986 return ((DECL_FIELD_CONTEXT (fieldsx
[0])
987 == DECL_FIELD_CONTEXT (fieldsy
[0]))
988 && fieldsx
[0] != fieldsy
[0]
989 && !(DECL_BIT_FIELD (fieldsx
[0]) && DECL_BIT_FIELD (fieldsy
[0])));
991 if (fieldsx
.length () == 2)
993 if (ncr_compar (&fieldsx
[0], &fieldsx
[1]) == 1)
994 std::swap (fieldsx
[0], fieldsx
[1]);
997 fieldsx
.qsort (ncr_compar
);
999 if (fieldsy
.length () == 2)
1001 if (ncr_compar (&fieldsy
[0], &fieldsy
[1]) == 1)
1002 std::swap (fieldsy
[0], fieldsy
[1]);
1005 fieldsy
.qsort (ncr_compar
);
1007 unsigned i
= 0, j
= 0;
1010 const_tree fieldx
= fieldsx
[i
];
1011 const_tree fieldy
= fieldsy
[j
];
1012 tree typex
= DECL_FIELD_CONTEXT (fieldx
);
1013 tree typey
= DECL_FIELD_CONTEXT (fieldy
);
1016 /* We're left with accessing different fields of a structure,
1017 no possible overlap, unless they are both bitfields. */
1018 if (fieldx
!= fieldy
)
1019 return !(DECL_BIT_FIELD (fieldx
) && DECL_BIT_FIELD (fieldy
));
1021 if (TYPE_UID (typex
) < TYPE_UID (typey
))
1024 if (i
== fieldsx
.length ())
1030 if (j
== fieldsy
.length ())
1040 /* Return true if two memory references based on the variables BASE1
1041 and BASE2 constrained to [OFFSET1, OFFSET1 + MAX_SIZE1) and
1042 [OFFSET2, OFFSET2 + MAX_SIZE2) may alias. REF1 and REF2
1043 if non-NULL are the complete memory reference trees. */
1046 decl_refs_may_alias_p (tree ref1
, tree base1
,
1047 HOST_WIDE_INT offset1
, HOST_WIDE_INT max_size1
,
1048 tree ref2
, tree base2
,
1049 HOST_WIDE_INT offset2
, HOST_WIDE_INT max_size2
)
1051 gcc_checking_assert (DECL_P (base1
) && DECL_P (base2
));
1053 /* If both references are based on different variables, they cannot alias. */
1054 if (compare_base_decls (base1
, base2
) == 0)
1057 /* If both references are based on the same variable, they cannot alias if
1058 the accesses do not overlap. */
1059 if (!ranges_overlap_p (offset1
, max_size1
, offset2
, max_size2
))
1062 /* For components with variable position, the above test isn't sufficient,
1063 so we disambiguate component references manually. */
1065 && handled_component_p (ref1
) && handled_component_p (ref2
)
1066 && nonoverlapping_component_refs_of_decl_p (ref1
, ref2
))
1072 /* Return true if an indirect reference based on *PTR1 constrained
1073 to [OFFSET1, OFFSET1 + MAX_SIZE1) may alias a variable based on BASE2
1074 constrained to [OFFSET2, OFFSET2 + MAX_SIZE2). *PTR1 and BASE2 have
1075 the alias sets BASE1_ALIAS_SET and BASE2_ALIAS_SET which can be -1
1076 in which case they are computed on-demand. REF1 and REF2
1077 if non-NULL are the complete memory reference trees. */
1080 indirect_ref_may_alias_decl_p (tree ref1 ATTRIBUTE_UNUSED
, tree base1
,
1081 HOST_WIDE_INT offset1
,
1082 HOST_WIDE_INT max_size1 ATTRIBUTE_UNUSED
,
1083 alias_set_type ref1_alias_set
,
1084 alias_set_type base1_alias_set
,
1085 tree ref2 ATTRIBUTE_UNUSED
, tree base2
,
1086 HOST_WIDE_INT offset2
, HOST_WIDE_INT max_size2
,
1087 alias_set_type ref2_alias_set
,
1088 alias_set_type base2_alias_set
, bool tbaa_p
)
1091 tree ptrtype1
, dbase2
;
1092 HOST_WIDE_INT offset1p
= offset1
, offset2p
= offset2
;
1093 HOST_WIDE_INT doffset1
, doffset2
;
1095 gcc_checking_assert ((TREE_CODE (base1
) == MEM_REF
1096 || TREE_CODE (base1
) == TARGET_MEM_REF
)
1099 ptr1
= TREE_OPERAND (base1
, 0);
1101 /* The offset embedded in MEM_REFs can be negative. Bias them
1102 so that the resulting offset adjustment is positive. */
1103 offset_int moff
= mem_ref_offset (base1
);
1104 moff
= wi::lshift (moff
, LOG2_BITS_PER_UNIT
);
1105 if (wi::neg_p (moff
))
1106 offset2p
+= (-moff
).to_short_addr ();
1108 offset1p
+= moff
.to_short_addr ();
1110 /* If only one reference is based on a variable, they cannot alias if
1111 the pointer access is beyond the extent of the variable access.
1112 (the pointer base cannot validly point to an offset less than zero
1114 ??? IVOPTs creates bases that do not honor this restriction,
1115 so do not apply this optimization for TARGET_MEM_REFs. */
1116 if (TREE_CODE (base1
) != TARGET_MEM_REF
1117 && !ranges_overlap_p (MAX (0, offset1p
), -1, offset2p
, max_size2
))
1119 /* They also cannot alias if the pointer may not point to the decl. */
1120 if (!ptr_deref_may_alias_decl_p (ptr1
, base2
))
1123 /* Disambiguations that rely on strict aliasing rules follow. */
1124 if (!flag_strict_aliasing
|| !tbaa_p
)
1127 ptrtype1
= TREE_TYPE (TREE_OPERAND (base1
, 1));
1129 /* If the alias set for a pointer access is zero all bets are off. */
1130 if (base1_alias_set
== 0)
1133 /* When we are trying to disambiguate an access with a pointer dereference
1134 as base versus one with a decl as base we can use both the size
1135 of the decl and its dynamic type for extra disambiguation.
1136 ??? We do not know anything about the dynamic type of the decl
1137 other than that its alias-set contains base2_alias_set as a subset
1138 which does not help us here. */
1139 /* As we know nothing useful about the dynamic type of the decl just
1140 use the usual conflict check rather than a subset test.
1141 ??? We could introduce -fvery-strict-aliasing when the language
1142 does not allow decls to have a dynamic type that differs from their
1143 static type. Then we can check
1144 !alias_set_subset_of (base1_alias_set, base2_alias_set) instead. */
1145 if (base1_alias_set
!= base2_alias_set
1146 && !alias_sets_conflict_p (base1_alias_set
, base2_alias_set
))
1148 /* If the size of the access relevant for TBAA through the pointer
1149 is bigger than the size of the decl we can't possibly access the
1150 decl via that pointer. */
1151 if (DECL_SIZE (base2
) && COMPLETE_TYPE_P (TREE_TYPE (ptrtype1
))
1152 && TREE_CODE (DECL_SIZE (base2
)) == INTEGER_CST
1153 && TREE_CODE (TYPE_SIZE (TREE_TYPE (ptrtype1
))) == INTEGER_CST
1154 /* ??? This in turn may run afoul when a decl of type T which is
1155 a member of union type U is accessed through a pointer to
1156 type U and sizeof T is smaller than sizeof U. */
1157 && TREE_CODE (TREE_TYPE (ptrtype1
)) != UNION_TYPE
1158 && TREE_CODE (TREE_TYPE (ptrtype1
)) != QUAL_UNION_TYPE
1159 && tree_int_cst_lt (DECL_SIZE (base2
), TYPE_SIZE (TREE_TYPE (ptrtype1
))))
1165 /* If the decl is accessed via a MEM_REF, reconstruct the base
1166 we can use for TBAA and an appropriately adjusted offset. */
1168 while (handled_component_p (dbase2
))
1169 dbase2
= TREE_OPERAND (dbase2
, 0);
1172 if (TREE_CODE (dbase2
) == MEM_REF
1173 || TREE_CODE (dbase2
) == TARGET_MEM_REF
)
1175 offset_int moff
= mem_ref_offset (dbase2
);
1176 moff
= wi::lshift (moff
, LOG2_BITS_PER_UNIT
);
1177 if (wi::neg_p (moff
))
1178 doffset1
-= (-moff
).to_short_addr ();
1180 doffset2
-= moff
.to_short_addr ();
1183 /* If either reference is view-converted, give up now. */
1184 if (same_type_for_tbaa (TREE_TYPE (base1
), TREE_TYPE (ptrtype1
)) != 1
1185 || same_type_for_tbaa (TREE_TYPE (dbase2
), TREE_TYPE (base2
)) != 1)
1188 /* If both references are through the same type, they do not alias
1189 if the accesses do not overlap. This does extra disambiguation
1190 for mixed/pointer accesses but requires strict aliasing.
1191 For MEM_REFs we require that the component-ref offset we computed
1192 is relative to the start of the type which we ensure by
1193 comparing rvalue and access type and disregarding the constant
1195 if ((TREE_CODE (base1
) != TARGET_MEM_REF
1196 || (!TMR_INDEX (base1
) && !TMR_INDEX2 (base1
)))
1197 && same_type_for_tbaa (TREE_TYPE (base1
), TREE_TYPE (dbase2
)) == 1)
1198 return ranges_overlap_p (doffset1
, max_size1
, doffset2
, max_size2
);
1201 && nonoverlapping_component_refs_p (ref1
, ref2
))
1204 /* Do access-path based disambiguation. */
1206 && (handled_component_p (ref1
) || handled_component_p (ref2
)))
1207 return aliasing_component_refs_p (ref1
,
1208 ref1_alias_set
, base1_alias_set
,
1211 ref2_alias_set
, base2_alias_set
,
1212 offset2
, max_size2
, true);
1217 /* Return true if two indirect references based on *PTR1
1218 and *PTR2 constrained to [OFFSET1, OFFSET1 + MAX_SIZE1) and
1219 [OFFSET2, OFFSET2 + MAX_SIZE2) may alias. *PTR1 and *PTR2 have
1220 the alias sets BASE1_ALIAS_SET and BASE2_ALIAS_SET which can be -1
1221 in which case they are computed on-demand. REF1 and REF2
1222 if non-NULL are the complete memory reference trees. */
1225 indirect_refs_may_alias_p (tree ref1 ATTRIBUTE_UNUSED
, tree base1
,
1226 HOST_WIDE_INT offset1
, HOST_WIDE_INT max_size1
,
1227 alias_set_type ref1_alias_set
,
1228 alias_set_type base1_alias_set
,
1229 tree ref2 ATTRIBUTE_UNUSED
, tree base2
,
1230 HOST_WIDE_INT offset2
, HOST_WIDE_INT max_size2
,
1231 alias_set_type ref2_alias_set
,
1232 alias_set_type base2_alias_set
, bool tbaa_p
)
1236 tree ptrtype1
, ptrtype2
;
1238 gcc_checking_assert ((TREE_CODE (base1
) == MEM_REF
1239 || TREE_CODE (base1
) == TARGET_MEM_REF
)
1240 && (TREE_CODE (base2
) == MEM_REF
1241 || TREE_CODE (base2
) == TARGET_MEM_REF
));
1243 ptr1
= TREE_OPERAND (base1
, 0);
1244 ptr2
= TREE_OPERAND (base2
, 0);
1246 /* If both bases are based on pointers they cannot alias if they may not
1247 point to the same memory object or if they point to the same object
1248 and the accesses do not overlap. */
1249 if ((!cfun
|| gimple_in_ssa_p (cfun
))
1250 && operand_equal_p (ptr1
, ptr2
, 0)
1251 && (((TREE_CODE (base1
) != TARGET_MEM_REF
1252 || (!TMR_INDEX (base1
) && !TMR_INDEX2 (base1
)))
1253 && (TREE_CODE (base2
) != TARGET_MEM_REF
1254 || (!TMR_INDEX (base2
) && !TMR_INDEX2 (base2
))))
1255 || (TREE_CODE (base1
) == TARGET_MEM_REF
1256 && TREE_CODE (base2
) == TARGET_MEM_REF
1257 && (TMR_STEP (base1
) == TMR_STEP (base2
)
1258 || (TMR_STEP (base1
) && TMR_STEP (base2
)
1259 && operand_equal_p (TMR_STEP (base1
),
1260 TMR_STEP (base2
), 0)))
1261 && (TMR_INDEX (base1
) == TMR_INDEX (base2
)
1262 || (TMR_INDEX (base1
) && TMR_INDEX (base2
)
1263 && operand_equal_p (TMR_INDEX (base1
),
1264 TMR_INDEX (base2
), 0)))
1265 && (TMR_INDEX2 (base1
) == TMR_INDEX2 (base2
)
1266 || (TMR_INDEX2 (base1
) && TMR_INDEX2 (base2
)
1267 && operand_equal_p (TMR_INDEX2 (base1
),
1268 TMR_INDEX2 (base2
), 0))))))
1271 /* The offset embedded in MEM_REFs can be negative. Bias them
1272 so that the resulting offset adjustment is positive. */
1273 moff
= mem_ref_offset (base1
);
1274 moff
= wi::lshift (moff
, LOG2_BITS_PER_UNIT
);
1275 if (wi::neg_p (moff
))
1276 offset2
+= (-moff
).to_short_addr ();
1278 offset1
+= moff
.to_shwi ();
1279 moff
= mem_ref_offset (base2
);
1280 moff
= wi::lshift (moff
, LOG2_BITS_PER_UNIT
);
1281 if (wi::neg_p (moff
))
1282 offset1
+= (-moff
).to_short_addr ();
1284 offset2
+= moff
.to_short_addr ();
1285 return ranges_overlap_p (offset1
, max_size1
, offset2
, max_size2
);
1287 if (!ptr_derefs_may_alias_p (ptr1
, ptr2
))
1290 /* Disambiguations that rely on strict aliasing rules follow. */
1291 if (!flag_strict_aliasing
|| !tbaa_p
)
1294 ptrtype1
= TREE_TYPE (TREE_OPERAND (base1
, 1));
1295 ptrtype2
= TREE_TYPE (TREE_OPERAND (base2
, 1));
1297 /* If the alias set for a pointer access is zero all bets are off. */
1298 if (base1_alias_set
== 0
1299 || base2_alias_set
== 0)
1302 /* If both references are through the same type, they do not alias
1303 if the accesses do not overlap. This does extra disambiguation
1304 for mixed/pointer accesses but requires strict aliasing. */
1305 if ((TREE_CODE (base1
) != TARGET_MEM_REF
1306 || (!TMR_INDEX (base1
) && !TMR_INDEX2 (base1
)))
1307 && (TREE_CODE (base2
) != TARGET_MEM_REF
1308 || (!TMR_INDEX (base2
) && !TMR_INDEX2 (base2
)))
1309 && same_type_for_tbaa (TREE_TYPE (base1
), TREE_TYPE (ptrtype1
)) == 1
1310 && same_type_for_tbaa (TREE_TYPE (base2
), TREE_TYPE (ptrtype2
)) == 1
1311 && same_type_for_tbaa (TREE_TYPE (ptrtype1
),
1312 TREE_TYPE (ptrtype2
)) == 1)
1313 return ranges_overlap_p (offset1
, max_size1
, offset2
, max_size2
);
1315 /* Do type-based disambiguation. */
1316 if (base1_alias_set
!= base2_alias_set
1317 && !alias_sets_conflict_p (base1_alias_set
, base2_alias_set
))
1320 /* If either reference is view-converted, give up now. */
1321 if (same_type_for_tbaa (TREE_TYPE (base1
), TREE_TYPE (ptrtype1
)) != 1
1322 || same_type_for_tbaa (TREE_TYPE (base2
), TREE_TYPE (ptrtype2
)) != 1)
1326 && nonoverlapping_component_refs_p (ref1
, ref2
))
1329 /* Do access-path based disambiguation. */
1331 && (handled_component_p (ref1
) || handled_component_p (ref2
)))
1332 return aliasing_component_refs_p (ref1
,
1333 ref1_alias_set
, base1_alias_set
,
1336 ref2_alias_set
, base2_alias_set
,
1337 offset2
, max_size2
, false);
1342 /* Return true, if the two memory references REF1 and REF2 may alias. */
1345 refs_may_alias_p_1 (ao_ref
*ref1
, ao_ref
*ref2
, bool tbaa_p
)
1348 HOST_WIDE_INT offset1
= 0, offset2
= 0;
1349 HOST_WIDE_INT max_size1
= -1, max_size2
= -1;
1350 bool var1_p
, var2_p
, ind1_p
, ind2_p
;
1352 gcc_checking_assert ((!ref1
->ref
1353 || TREE_CODE (ref1
->ref
) == SSA_NAME
1354 || DECL_P (ref1
->ref
)
1355 || TREE_CODE (ref1
->ref
) == STRING_CST
1356 || handled_component_p (ref1
->ref
)
1357 || TREE_CODE (ref1
->ref
) == MEM_REF
1358 || TREE_CODE (ref1
->ref
) == TARGET_MEM_REF
)
1360 || TREE_CODE (ref2
->ref
) == SSA_NAME
1361 || DECL_P (ref2
->ref
)
1362 || TREE_CODE (ref2
->ref
) == STRING_CST
1363 || handled_component_p (ref2
->ref
)
1364 || TREE_CODE (ref2
->ref
) == MEM_REF
1365 || TREE_CODE (ref2
->ref
) == TARGET_MEM_REF
));
1367 /* Decompose the references into their base objects and the access. */
1368 base1
= ao_ref_base (ref1
);
1369 offset1
= ref1
->offset
;
1370 max_size1
= ref1
->max_size
;
1371 base2
= ao_ref_base (ref2
);
1372 offset2
= ref2
->offset
;
1373 max_size2
= ref2
->max_size
;
1375 /* We can end up with registers or constants as bases for example from
1376 *D.1663_44 = VIEW_CONVERT_EXPR<struct DB_LSN>(__tmp$B0F64_59);
1377 which is seen as a struct copy. */
1378 if (TREE_CODE (base1
) == SSA_NAME
1379 || TREE_CODE (base1
) == CONST_DECL
1380 || TREE_CODE (base1
) == CONSTRUCTOR
1381 || TREE_CODE (base1
) == ADDR_EXPR
1382 || CONSTANT_CLASS_P (base1
)
1383 || TREE_CODE (base2
) == SSA_NAME
1384 || TREE_CODE (base2
) == CONST_DECL
1385 || TREE_CODE (base2
) == CONSTRUCTOR
1386 || TREE_CODE (base2
) == ADDR_EXPR
1387 || CONSTANT_CLASS_P (base2
))
1390 /* We can end up referring to code via function and label decls.
1391 As we likely do not properly track code aliases conservatively
1393 if (TREE_CODE (base1
) == FUNCTION_DECL
1394 || TREE_CODE (base1
) == LABEL_DECL
1395 || TREE_CODE (base2
) == FUNCTION_DECL
1396 || TREE_CODE (base2
) == LABEL_DECL
)
1399 /* Two volatile accesses always conflict. */
1400 if (ref1
->volatile_p
1401 && ref2
->volatile_p
)
1404 /* Defer to simple offset based disambiguation if we have
1405 references based on two decls. Do this before defering to
1406 TBAA to handle must-alias cases in conformance with the
1407 GCC extension of allowing type-punning through unions. */
1408 var1_p
= DECL_P (base1
);
1409 var2_p
= DECL_P (base2
);
1410 if (var1_p
&& var2_p
)
1411 return decl_refs_may_alias_p (ref1
->ref
, base1
, offset1
, max_size1
,
1412 ref2
->ref
, base2
, offset2
, max_size2
);
1414 /* Handle restrict based accesses.
1415 ??? ao_ref_base strips inner MEM_REF [&decl], recover from that
1417 tree rbase1
= base1
;
1418 tree rbase2
= base2
;
1423 while (handled_component_p (rbase1
))
1424 rbase1
= TREE_OPERAND (rbase1
, 0);
1430 while (handled_component_p (rbase2
))
1431 rbase2
= TREE_OPERAND (rbase2
, 0);
1433 if (rbase1
&& rbase2
1434 && (TREE_CODE (base1
) == MEM_REF
|| TREE_CODE (base1
) == TARGET_MEM_REF
)
1435 && (TREE_CODE (base2
) == MEM_REF
|| TREE_CODE (base2
) == TARGET_MEM_REF
)
1436 /* If the accesses are in the same restrict clique... */
1437 && MR_DEPENDENCE_CLIQUE (base1
) == MR_DEPENDENCE_CLIQUE (base2
)
1438 /* But based on different pointers they do not alias. */
1439 && MR_DEPENDENCE_BASE (base1
) != MR_DEPENDENCE_BASE (base2
))
1442 ind1_p
= (TREE_CODE (base1
) == MEM_REF
1443 || TREE_CODE (base1
) == TARGET_MEM_REF
);
1444 ind2_p
= (TREE_CODE (base2
) == MEM_REF
1445 || TREE_CODE (base2
) == TARGET_MEM_REF
);
1447 /* Canonicalize the pointer-vs-decl case. */
1448 if (ind1_p
&& var2_p
)
1450 std::swap (offset1
, offset2
);
1451 std::swap (max_size1
, max_size2
);
1452 std::swap (base1
, base2
);
1453 std::swap (ref1
, ref2
);
1460 /* First defer to TBAA if possible. */
1462 && flag_strict_aliasing
1463 && !alias_sets_conflict_p (ao_ref_alias_set (ref1
),
1464 ao_ref_alias_set (ref2
)))
1467 /* Dispatch to the pointer-vs-decl or pointer-vs-pointer disambiguators. */
1468 if (var1_p
&& ind2_p
)
1469 return indirect_ref_may_alias_decl_p (ref2
->ref
, base2
,
1471 ao_ref_alias_set (ref2
),
1472 ao_ref_base_alias_set (ref2
),
1475 ao_ref_alias_set (ref1
),
1476 ao_ref_base_alias_set (ref1
),
1478 else if (ind1_p
&& ind2_p
)
1479 return indirect_refs_may_alias_p (ref1
->ref
, base1
,
1481 ao_ref_alias_set (ref1
),
1482 ao_ref_base_alias_set (ref1
),
1485 ao_ref_alias_set (ref2
),
1486 ao_ref_base_alias_set (ref2
),
1493 refs_may_alias_p (tree ref1
, ao_ref
*ref2
)
1496 ao_ref_init (&r1
, ref1
);
1497 return refs_may_alias_p_1 (&r1
, ref2
, true);
1501 refs_may_alias_p (tree ref1
, tree ref2
)
1505 ao_ref_init (&r1
, ref1
);
1506 ao_ref_init (&r2
, ref2
);
1507 res
= refs_may_alias_p_1 (&r1
, &r2
, true);
1509 ++alias_stats
.refs_may_alias_p_may_alias
;
1511 ++alias_stats
.refs_may_alias_p_no_alias
;
1515 /* Returns true if there is a anti-dependence for the STORE that
1516 executes after the LOAD. */
1519 refs_anti_dependent_p (tree load
, tree store
)
1522 ao_ref_init (&r1
, load
);
1523 ao_ref_init (&r2
, store
);
1524 return refs_may_alias_p_1 (&r1
, &r2
, false);
1527 /* Returns true if there is a output dependence for the stores
1528 STORE1 and STORE2. */
1531 refs_output_dependent_p (tree store1
, tree store2
)
1534 ao_ref_init (&r1
, store1
);
1535 ao_ref_init (&r2
, store2
);
1536 return refs_may_alias_p_1 (&r1
, &r2
, false);
1539 /* If the call CALL may use the memory reference REF return true,
1540 otherwise return false. */
1543 ref_maybe_used_by_call_p_1 (gcall
*call
, ao_ref
*ref
)
1547 int flags
= gimple_call_flags (call
);
1549 /* Const functions without a static chain do not implicitly use memory. */
1550 if (!gimple_call_chain (call
)
1551 && (flags
& (ECF_CONST
|ECF_NOVOPS
)))
1554 base
= ao_ref_base (ref
);
1558 /* A call that is not without side-effects might involve volatile
1559 accesses and thus conflicts with all other volatile accesses. */
1560 if (ref
->volatile_p
)
1563 /* If the reference is based on a decl that is not aliased the call
1564 cannot possibly use it. */
1566 && !may_be_aliased (base
)
1567 /* But local statics can be used through recursion. */
1568 && !is_global_var (base
))
1571 callee
= gimple_call_fndecl (call
);
1573 /* Handle those builtin functions explicitly that do not act as
1574 escape points. See tree-ssa-structalias.c:find_func_aliases
1575 for the list of builtins we might need to handle here. */
1576 if (callee
!= NULL_TREE
1577 && gimple_call_builtin_p (call
, BUILT_IN_NORMAL
))
1578 switch (DECL_FUNCTION_CODE (callee
))
1580 /* All the following functions read memory pointed to by
1581 their second argument. strcat/strncat additionally
1582 reads memory pointed to by the first argument. */
1583 case BUILT_IN_STRCAT
:
1584 case BUILT_IN_STRNCAT
:
1587 ao_ref_init_from_ptr_and_size (&dref
,
1588 gimple_call_arg (call
, 0),
1590 if (refs_may_alias_p_1 (&dref
, ref
, false))
1594 case BUILT_IN_STRCPY
:
1595 case BUILT_IN_STRNCPY
:
1596 case BUILT_IN_MEMCPY
:
1597 case BUILT_IN_MEMMOVE
:
1598 case BUILT_IN_MEMPCPY
:
1599 case BUILT_IN_STPCPY
:
1600 case BUILT_IN_STPNCPY
:
1601 case BUILT_IN_TM_MEMCPY
:
1602 case BUILT_IN_TM_MEMMOVE
:
1605 tree size
= NULL_TREE
;
1606 if (gimple_call_num_args (call
) == 3)
1607 size
= gimple_call_arg (call
, 2);
1608 ao_ref_init_from_ptr_and_size (&dref
,
1609 gimple_call_arg (call
, 1),
1611 return refs_may_alias_p_1 (&dref
, ref
, false);
1613 case BUILT_IN_STRCAT_CHK
:
1614 case BUILT_IN_STRNCAT_CHK
:
1617 ao_ref_init_from_ptr_and_size (&dref
,
1618 gimple_call_arg (call
, 0),
1620 if (refs_may_alias_p_1 (&dref
, ref
, false))
1624 case BUILT_IN_STRCPY_CHK
:
1625 case BUILT_IN_STRNCPY_CHK
:
1626 case BUILT_IN_MEMCPY_CHK
:
1627 case BUILT_IN_MEMMOVE_CHK
:
1628 case BUILT_IN_MEMPCPY_CHK
:
1629 case BUILT_IN_STPCPY_CHK
:
1630 case BUILT_IN_STPNCPY_CHK
:
1633 tree size
= NULL_TREE
;
1634 if (gimple_call_num_args (call
) == 4)
1635 size
= gimple_call_arg (call
, 2);
1636 ao_ref_init_from_ptr_and_size (&dref
,
1637 gimple_call_arg (call
, 1),
1639 return refs_may_alias_p_1 (&dref
, ref
, false);
1641 case BUILT_IN_BCOPY
:
1644 tree size
= gimple_call_arg (call
, 2);
1645 ao_ref_init_from_ptr_and_size (&dref
,
1646 gimple_call_arg (call
, 0),
1648 return refs_may_alias_p_1 (&dref
, ref
, false);
1651 /* The following functions read memory pointed to by their
1653 CASE_BUILT_IN_TM_LOAD (1):
1654 CASE_BUILT_IN_TM_LOAD (2):
1655 CASE_BUILT_IN_TM_LOAD (4):
1656 CASE_BUILT_IN_TM_LOAD (8):
1657 CASE_BUILT_IN_TM_LOAD (FLOAT
):
1658 CASE_BUILT_IN_TM_LOAD (DOUBLE
):
1659 CASE_BUILT_IN_TM_LOAD (LDOUBLE
):
1660 CASE_BUILT_IN_TM_LOAD (M64
):
1661 CASE_BUILT_IN_TM_LOAD (M128
):
1662 CASE_BUILT_IN_TM_LOAD (M256
):
1663 case BUILT_IN_TM_LOG
:
1664 case BUILT_IN_TM_LOG_1
:
1665 case BUILT_IN_TM_LOG_2
:
1666 case BUILT_IN_TM_LOG_4
:
1667 case BUILT_IN_TM_LOG_8
:
1668 case BUILT_IN_TM_LOG_FLOAT
:
1669 case BUILT_IN_TM_LOG_DOUBLE
:
1670 case BUILT_IN_TM_LOG_LDOUBLE
:
1671 case BUILT_IN_TM_LOG_M64
:
1672 case BUILT_IN_TM_LOG_M128
:
1673 case BUILT_IN_TM_LOG_M256
:
1674 return ptr_deref_may_alias_ref_p_1 (gimple_call_arg (call
, 0), ref
);
1676 /* These read memory pointed to by the first argument. */
1677 case BUILT_IN_STRDUP
:
1678 case BUILT_IN_STRNDUP
:
1679 case BUILT_IN_REALLOC
:
1682 tree size
= NULL_TREE
;
1683 if (gimple_call_num_args (call
) == 2)
1684 size
= gimple_call_arg (call
, 1);
1685 ao_ref_init_from_ptr_and_size (&dref
,
1686 gimple_call_arg (call
, 0),
1688 return refs_may_alias_p_1 (&dref
, ref
, false);
1690 /* These read memory pointed to by the first argument. */
1691 case BUILT_IN_INDEX
:
1692 case BUILT_IN_STRCHR
:
1693 case BUILT_IN_STRRCHR
:
1696 ao_ref_init_from_ptr_and_size (&dref
,
1697 gimple_call_arg (call
, 0),
1699 return refs_may_alias_p_1 (&dref
, ref
, false);
1701 /* These read memory pointed to by the first argument with size
1702 in the third argument. */
1703 case BUILT_IN_MEMCHR
:
1706 ao_ref_init_from_ptr_and_size (&dref
,
1707 gimple_call_arg (call
, 0),
1708 gimple_call_arg (call
, 2));
1709 return refs_may_alias_p_1 (&dref
, ref
, false);
1711 /* These read memory pointed to by the first and second arguments. */
1712 case BUILT_IN_STRSTR
:
1713 case BUILT_IN_STRPBRK
:
1716 ao_ref_init_from_ptr_and_size (&dref
,
1717 gimple_call_arg (call
, 0),
1719 if (refs_may_alias_p_1 (&dref
, ref
, false))
1721 ao_ref_init_from_ptr_and_size (&dref
,
1722 gimple_call_arg (call
, 1),
1724 return refs_may_alias_p_1 (&dref
, ref
, false);
1727 /* The following builtins do not read from memory. */
1729 case BUILT_IN_MALLOC
:
1730 case BUILT_IN_POSIX_MEMALIGN
:
1731 case BUILT_IN_ALIGNED_ALLOC
:
1732 case BUILT_IN_CALLOC
:
1733 case BUILT_IN_ALLOCA
:
1734 case BUILT_IN_ALLOCA_WITH_ALIGN
:
1735 case BUILT_IN_STACK_SAVE
:
1736 case BUILT_IN_STACK_RESTORE
:
1737 case BUILT_IN_MEMSET
:
1738 case BUILT_IN_TM_MEMSET
:
1739 case BUILT_IN_MEMSET_CHK
:
1740 case BUILT_IN_FREXP
:
1741 case BUILT_IN_FREXPF
:
1742 case BUILT_IN_FREXPL
:
1743 case BUILT_IN_GAMMA_R
:
1744 case BUILT_IN_GAMMAF_R
:
1745 case BUILT_IN_GAMMAL_R
:
1746 case BUILT_IN_LGAMMA_R
:
1747 case BUILT_IN_LGAMMAF_R
:
1748 case BUILT_IN_LGAMMAL_R
:
1750 case BUILT_IN_MODFF
:
1751 case BUILT_IN_MODFL
:
1752 case BUILT_IN_REMQUO
:
1753 case BUILT_IN_REMQUOF
:
1754 case BUILT_IN_REMQUOL
:
1755 case BUILT_IN_SINCOS
:
1756 case BUILT_IN_SINCOSF
:
1757 case BUILT_IN_SINCOSL
:
1758 case BUILT_IN_ASSUME_ALIGNED
:
1759 case BUILT_IN_VA_END
:
1761 /* __sync_* builtins and some OpenMP builtins act as threading
1763 #undef DEF_SYNC_BUILTIN
1764 #define DEF_SYNC_BUILTIN(ENUM, NAME, TYPE, ATTRS) case ENUM:
1765 #include "sync-builtins.def"
1766 #undef DEF_SYNC_BUILTIN
1767 case BUILT_IN_GOMP_ATOMIC_START
:
1768 case BUILT_IN_GOMP_ATOMIC_END
:
1769 case BUILT_IN_GOMP_BARRIER
:
1770 case BUILT_IN_GOMP_BARRIER_CANCEL
:
1771 case BUILT_IN_GOMP_TASKWAIT
:
1772 case BUILT_IN_GOMP_TASKGROUP_END
:
1773 case BUILT_IN_GOMP_CRITICAL_START
:
1774 case BUILT_IN_GOMP_CRITICAL_END
:
1775 case BUILT_IN_GOMP_CRITICAL_NAME_START
:
1776 case BUILT_IN_GOMP_CRITICAL_NAME_END
:
1777 case BUILT_IN_GOMP_LOOP_END
:
1778 case BUILT_IN_GOMP_LOOP_END_CANCEL
:
1779 case BUILT_IN_GOMP_ORDERED_START
:
1780 case BUILT_IN_GOMP_ORDERED_END
:
1781 case BUILT_IN_GOMP_SECTIONS_END
:
1782 case BUILT_IN_GOMP_SECTIONS_END_CANCEL
:
1783 case BUILT_IN_GOMP_SINGLE_COPY_START
:
1784 case BUILT_IN_GOMP_SINGLE_COPY_END
:
1788 /* Fallthru to general call handling. */;
1791 /* Check if base is a global static variable that is not read
1793 if (callee
!= NULL_TREE
1794 && TREE_CODE (base
) == VAR_DECL
1795 && TREE_STATIC (base
))
1797 struct cgraph_node
*node
= cgraph_node::get (callee
);
1800 /* FIXME: Callee can be an OMP builtin that does not have a call graph
1801 node yet. We should enforce that there are nodes for all decls in the
1802 IL and remove this check instead. */
1804 && (not_read
= ipa_reference_get_not_read_global (node
))
1805 && bitmap_bit_p (not_read
, ipa_reference_var_uid (base
)))
1809 /* Check if the base variable is call-used. */
1812 if (pt_solution_includes (gimple_call_use_set (call
), base
))
1815 else if ((TREE_CODE (base
) == MEM_REF
1816 || TREE_CODE (base
) == TARGET_MEM_REF
)
1817 && TREE_CODE (TREE_OPERAND (base
, 0)) == SSA_NAME
)
1819 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (TREE_OPERAND (base
, 0));
1823 if (pt_solutions_intersect (gimple_call_use_set (call
), &pi
->pt
))
1829 /* Inspect call arguments for passed-by-value aliases. */
1831 for (i
= 0; i
< gimple_call_num_args (call
); ++i
)
1833 tree op
= gimple_call_arg (call
, i
);
1834 int flags
= gimple_call_arg_flags (call
, i
);
1836 if (flags
& EAF_UNUSED
)
1839 if (TREE_CODE (op
) == WITH_SIZE_EXPR
)
1840 op
= TREE_OPERAND (op
, 0);
1842 if (TREE_CODE (op
) != SSA_NAME
1843 && !is_gimple_min_invariant (op
))
1846 ao_ref_init (&r
, op
);
1847 if (refs_may_alias_p_1 (&r
, ref
, true))
1856 ref_maybe_used_by_call_p (gcall
*call
, ao_ref
*ref
)
1859 res
= ref_maybe_used_by_call_p_1 (call
, ref
);
1861 ++alias_stats
.ref_maybe_used_by_call_p_may_alias
;
1863 ++alias_stats
.ref_maybe_used_by_call_p_no_alias
;
1868 /* If the statement STMT may use the memory reference REF return
1869 true, otherwise return false. */
1872 ref_maybe_used_by_stmt_p (gimple
*stmt
, ao_ref
*ref
)
1874 if (is_gimple_assign (stmt
))
1878 /* All memory assign statements are single. */
1879 if (!gimple_assign_single_p (stmt
))
1882 rhs
= gimple_assign_rhs1 (stmt
);
1883 if (is_gimple_reg (rhs
)
1884 || is_gimple_min_invariant (rhs
)
1885 || gimple_assign_rhs_code (stmt
) == CONSTRUCTOR
)
1888 return refs_may_alias_p (rhs
, ref
);
1890 else if (is_gimple_call (stmt
))
1891 return ref_maybe_used_by_call_p (as_a
<gcall
*> (stmt
), ref
);
1892 else if (greturn
*return_stmt
= dyn_cast
<greturn
*> (stmt
))
1894 tree retval
= gimple_return_retval (return_stmt
);
1896 && TREE_CODE (retval
) != SSA_NAME
1897 && !is_gimple_min_invariant (retval
)
1898 && refs_may_alias_p (retval
, ref
))
1900 /* If ref escapes the function then the return acts as a use. */
1901 tree base
= ao_ref_base (ref
);
1904 else if (DECL_P (base
))
1905 return is_global_var (base
);
1906 else if (TREE_CODE (base
) == MEM_REF
1907 || TREE_CODE (base
) == TARGET_MEM_REF
)
1908 return ptr_deref_may_alias_global_p (TREE_OPERAND (base
, 0));
1916 ref_maybe_used_by_stmt_p (gimple
*stmt
, tree ref
)
1919 ao_ref_init (&r
, ref
);
1920 return ref_maybe_used_by_stmt_p (stmt
, &r
);
1923 /* If the call in statement CALL may clobber the memory reference REF
1924 return true, otherwise return false. */
1927 call_may_clobber_ref_p_1 (gcall
*call
, ao_ref
*ref
)
1932 /* If the call is pure or const it cannot clobber anything. */
1933 if (gimple_call_flags (call
)
1934 & (ECF_PURE
|ECF_CONST
|ECF_LOOPING_CONST_OR_PURE
|ECF_NOVOPS
))
1936 if (gimple_call_internal_p (call
))
1937 switch (gimple_call_internal_fn (call
))
1939 /* Treat these internal calls like ECF_PURE for aliasing,
1940 they don't write to any memory the program should care about.
1941 They have important other side-effects, and read memory,
1942 so can't be ECF_NOVOPS. */
1943 case IFN_UBSAN_NULL
:
1944 case IFN_UBSAN_BOUNDS
:
1945 case IFN_UBSAN_VPTR
:
1946 case IFN_UBSAN_OBJECT_SIZE
:
1947 case IFN_ASAN_CHECK
:
1953 base
= ao_ref_base (ref
);
1957 if (TREE_CODE (base
) == SSA_NAME
1958 || CONSTANT_CLASS_P (base
))
1961 /* A call that is not without side-effects might involve volatile
1962 accesses and thus conflicts with all other volatile accesses. */
1963 if (ref
->volatile_p
)
1966 /* If the reference is based on a decl that is not aliased the call
1967 cannot possibly clobber it. */
1969 && !may_be_aliased (base
)
1970 /* But local non-readonly statics can be modified through recursion
1971 or the call may implement a threading barrier which we must
1972 treat as may-def. */
1973 && (TREE_READONLY (base
)
1974 || !is_global_var (base
)))
1977 callee
= gimple_call_fndecl (call
);
1979 /* Handle those builtin functions explicitly that do not act as
1980 escape points. See tree-ssa-structalias.c:find_func_aliases
1981 for the list of builtins we might need to handle here. */
1982 if (callee
!= NULL_TREE
1983 && gimple_call_builtin_p (call
, BUILT_IN_NORMAL
))
1984 switch (DECL_FUNCTION_CODE (callee
))
1986 /* All the following functions clobber memory pointed to by
1987 their first argument. */
1988 case BUILT_IN_STRCPY
:
1989 case BUILT_IN_STRNCPY
:
1990 case BUILT_IN_MEMCPY
:
1991 case BUILT_IN_MEMMOVE
:
1992 case BUILT_IN_MEMPCPY
:
1993 case BUILT_IN_STPCPY
:
1994 case BUILT_IN_STPNCPY
:
1995 case BUILT_IN_STRCAT
:
1996 case BUILT_IN_STRNCAT
:
1997 case BUILT_IN_MEMSET
:
1998 case BUILT_IN_TM_MEMSET
:
1999 CASE_BUILT_IN_TM_STORE (1):
2000 CASE_BUILT_IN_TM_STORE (2):
2001 CASE_BUILT_IN_TM_STORE (4):
2002 CASE_BUILT_IN_TM_STORE (8):
2003 CASE_BUILT_IN_TM_STORE (FLOAT
):
2004 CASE_BUILT_IN_TM_STORE (DOUBLE
):
2005 CASE_BUILT_IN_TM_STORE (LDOUBLE
):
2006 CASE_BUILT_IN_TM_STORE (M64
):
2007 CASE_BUILT_IN_TM_STORE (M128
):
2008 CASE_BUILT_IN_TM_STORE (M256
):
2009 case BUILT_IN_TM_MEMCPY
:
2010 case BUILT_IN_TM_MEMMOVE
:
2013 tree size
= NULL_TREE
;
2014 /* Don't pass in size for strncat, as the maximum size
2015 is strlen (dest) + n + 1 instead of n, resp.
2016 n + 1 at dest + strlen (dest), but strlen (dest) isn't
2018 if (gimple_call_num_args (call
) == 3
2019 && DECL_FUNCTION_CODE (callee
) != BUILT_IN_STRNCAT
)
2020 size
= gimple_call_arg (call
, 2);
2021 ao_ref_init_from_ptr_and_size (&dref
,
2022 gimple_call_arg (call
, 0),
2024 return refs_may_alias_p_1 (&dref
, ref
, false);
2026 case BUILT_IN_STRCPY_CHK
:
2027 case BUILT_IN_STRNCPY_CHK
:
2028 case BUILT_IN_MEMCPY_CHK
:
2029 case BUILT_IN_MEMMOVE_CHK
:
2030 case BUILT_IN_MEMPCPY_CHK
:
2031 case BUILT_IN_STPCPY_CHK
:
2032 case BUILT_IN_STPNCPY_CHK
:
2033 case BUILT_IN_STRCAT_CHK
:
2034 case BUILT_IN_STRNCAT_CHK
:
2035 case BUILT_IN_MEMSET_CHK
:
2038 tree size
= NULL_TREE
;
2039 /* Don't pass in size for __strncat_chk, as the maximum size
2040 is strlen (dest) + n + 1 instead of n, resp.
2041 n + 1 at dest + strlen (dest), but strlen (dest) isn't
2043 if (gimple_call_num_args (call
) == 4
2044 && DECL_FUNCTION_CODE (callee
) != BUILT_IN_STRNCAT_CHK
)
2045 size
= gimple_call_arg (call
, 2);
2046 ao_ref_init_from_ptr_and_size (&dref
,
2047 gimple_call_arg (call
, 0),
2049 return refs_may_alias_p_1 (&dref
, ref
, false);
2051 case BUILT_IN_BCOPY
:
2054 tree size
= gimple_call_arg (call
, 2);
2055 ao_ref_init_from_ptr_and_size (&dref
,
2056 gimple_call_arg (call
, 1),
2058 return refs_may_alias_p_1 (&dref
, ref
, false);
2060 /* Allocating memory does not have any side-effects apart from
2061 being the definition point for the pointer. */
2062 case BUILT_IN_MALLOC
:
2063 case BUILT_IN_ALIGNED_ALLOC
:
2064 case BUILT_IN_CALLOC
:
2065 case BUILT_IN_STRDUP
:
2066 case BUILT_IN_STRNDUP
:
2067 /* Unix98 specifies that errno is set on allocation failure. */
2069 && targetm
.ref_may_alias_errno (ref
))
2072 case BUILT_IN_STACK_SAVE
:
2073 case BUILT_IN_ALLOCA
:
2074 case BUILT_IN_ALLOCA_WITH_ALIGN
:
2075 case BUILT_IN_ASSUME_ALIGNED
:
2077 /* But posix_memalign stores a pointer into the memory pointed to
2078 by its first argument. */
2079 case BUILT_IN_POSIX_MEMALIGN
:
2081 tree ptrptr
= gimple_call_arg (call
, 0);
2083 ao_ref_init_from_ptr_and_size (&dref
, ptrptr
,
2084 TYPE_SIZE_UNIT (ptr_type_node
));
2085 return (refs_may_alias_p_1 (&dref
, ref
, false)
2087 && targetm
.ref_may_alias_errno (ref
)));
2089 /* Freeing memory kills the pointed-to memory. More importantly
2090 the call has to serve as a barrier for moving loads and stores
2093 case BUILT_IN_VA_END
:
2095 tree ptr
= gimple_call_arg (call
, 0);
2096 return ptr_deref_may_alias_ref_p_1 (ptr
, ref
);
2098 /* Realloc serves both as allocation point and deallocation point. */
2099 case BUILT_IN_REALLOC
:
2101 tree ptr
= gimple_call_arg (call
, 0);
2102 /* Unix98 specifies that errno is set on allocation failure. */
2103 return ((flag_errno_math
2104 && targetm
.ref_may_alias_errno (ref
))
2105 || ptr_deref_may_alias_ref_p_1 (ptr
, ref
));
2107 case BUILT_IN_GAMMA_R
:
2108 case BUILT_IN_GAMMAF_R
:
2109 case BUILT_IN_GAMMAL_R
:
2110 case BUILT_IN_LGAMMA_R
:
2111 case BUILT_IN_LGAMMAF_R
:
2112 case BUILT_IN_LGAMMAL_R
:
2114 tree out
= gimple_call_arg (call
, 1);
2115 if (ptr_deref_may_alias_ref_p_1 (out
, ref
))
2117 if (flag_errno_math
)
2121 case BUILT_IN_FREXP
:
2122 case BUILT_IN_FREXPF
:
2123 case BUILT_IN_FREXPL
:
2125 case BUILT_IN_MODFF
:
2126 case BUILT_IN_MODFL
:
2128 tree out
= gimple_call_arg (call
, 1);
2129 return ptr_deref_may_alias_ref_p_1 (out
, ref
);
2131 case BUILT_IN_REMQUO
:
2132 case BUILT_IN_REMQUOF
:
2133 case BUILT_IN_REMQUOL
:
2135 tree out
= gimple_call_arg (call
, 2);
2136 if (ptr_deref_may_alias_ref_p_1 (out
, ref
))
2138 if (flag_errno_math
)
2142 case BUILT_IN_SINCOS
:
2143 case BUILT_IN_SINCOSF
:
2144 case BUILT_IN_SINCOSL
:
2146 tree sin
= gimple_call_arg (call
, 1);
2147 tree cos
= gimple_call_arg (call
, 2);
2148 return (ptr_deref_may_alias_ref_p_1 (sin
, ref
)
2149 || ptr_deref_may_alias_ref_p_1 (cos
, ref
));
2151 /* __sync_* builtins and some OpenMP builtins act as threading
2153 #undef DEF_SYNC_BUILTIN
2154 #define DEF_SYNC_BUILTIN(ENUM, NAME, TYPE, ATTRS) case ENUM:
2155 #include "sync-builtins.def"
2156 #undef DEF_SYNC_BUILTIN
2157 case BUILT_IN_GOMP_ATOMIC_START
:
2158 case BUILT_IN_GOMP_ATOMIC_END
:
2159 case BUILT_IN_GOMP_BARRIER
:
2160 case BUILT_IN_GOMP_BARRIER_CANCEL
:
2161 case BUILT_IN_GOMP_TASKWAIT
:
2162 case BUILT_IN_GOMP_TASKGROUP_END
:
2163 case BUILT_IN_GOMP_CRITICAL_START
:
2164 case BUILT_IN_GOMP_CRITICAL_END
:
2165 case BUILT_IN_GOMP_CRITICAL_NAME_START
:
2166 case BUILT_IN_GOMP_CRITICAL_NAME_END
:
2167 case BUILT_IN_GOMP_LOOP_END
:
2168 case BUILT_IN_GOMP_LOOP_END_CANCEL
:
2169 case BUILT_IN_GOMP_ORDERED_START
:
2170 case BUILT_IN_GOMP_ORDERED_END
:
2171 case BUILT_IN_GOMP_SECTIONS_END
:
2172 case BUILT_IN_GOMP_SECTIONS_END_CANCEL
:
2173 case BUILT_IN_GOMP_SINGLE_COPY_START
:
2174 case BUILT_IN_GOMP_SINGLE_COPY_END
:
2177 /* Fallthru to general call handling. */;
2180 /* Check if base is a global static variable that is not written
2182 if (callee
!= NULL_TREE
2183 && TREE_CODE (base
) == VAR_DECL
2184 && TREE_STATIC (base
))
2186 struct cgraph_node
*node
= cgraph_node::get (callee
);
2190 && (not_written
= ipa_reference_get_not_written_global (node
))
2191 && bitmap_bit_p (not_written
, ipa_reference_var_uid (base
)))
2195 /* Check if the base variable is call-clobbered. */
2197 return pt_solution_includes (gimple_call_clobber_set (call
), base
);
2198 else if ((TREE_CODE (base
) == MEM_REF
2199 || TREE_CODE (base
) == TARGET_MEM_REF
)
2200 && TREE_CODE (TREE_OPERAND (base
, 0)) == SSA_NAME
)
2202 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (TREE_OPERAND (base
, 0));
2206 return pt_solutions_intersect (gimple_call_clobber_set (call
), &pi
->pt
);
2212 /* If the call in statement CALL may clobber the memory reference REF
2213 return true, otherwise return false. */
2216 call_may_clobber_ref_p (gcall
*call
, tree ref
)
2220 ao_ref_init (&r
, ref
);
2221 res
= call_may_clobber_ref_p_1 (call
, &r
);
2223 ++alias_stats
.call_may_clobber_ref_p_may_alias
;
2225 ++alias_stats
.call_may_clobber_ref_p_no_alias
;
2230 /* If the statement STMT may clobber the memory reference REF return true,
2231 otherwise return false. */
2234 stmt_may_clobber_ref_p_1 (gimple
*stmt
, ao_ref
*ref
)
2236 if (is_gimple_call (stmt
))
2238 tree lhs
= gimple_call_lhs (stmt
);
2240 && TREE_CODE (lhs
) != SSA_NAME
)
2243 ao_ref_init (&r
, lhs
);
2244 if (refs_may_alias_p_1 (ref
, &r
, true))
2248 return call_may_clobber_ref_p_1 (as_a
<gcall
*> (stmt
), ref
);
2250 else if (gimple_assign_single_p (stmt
))
2252 tree lhs
= gimple_assign_lhs (stmt
);
2253 if (TREE_CODE (lhs
) != SSA_NAME
)
2256 ao_ref_init (&r
, lhs
);
2257 return refs_may_alias_p_1 (ref
, &r
, true);
2260 else if (gimple_code (stmt
) == GIMPLE_ASM
)
2267 stmt_may_clobber_ref_p (gimple
*stmt
, tree ref
)
2270 ao_ref_init (&r
, ref
);
2271 return stmt_may_clobber_ref_p_1 (stmt
, &r
);
2274 /* If STMT kills the memory reference REF return true, otherwise
2278 stmt_kills_ref_p (gimple
*stmt
, ao_ref
*ref
)
2280 if (!ao_ref_base (ref
))
2283 if (gimple_has_lhs (stmt
)
2284 && TREE_CODE (gimple_get_lhs (stmt
)) != SSA_NAME
2285 /* The assignment is not necessarily carried out if it can throw
2286 and we can catch it in the current function where we could inspect
2288 ??? We only need to care about the RHS throwing. For aggregate
2289 assignments or similar calls and non-call exceptions the LHS
2290 might throw as well. */
2291 && !stmt_can_throw_internal (stmt
))
2293 tree lhs
= gimple_get_lhs (stmt
);
2294 /* If LHS is literally a base of the access we are done. */
2297 tree base
= ref
->ref
;
2298 if (handled_component_p (base
))
2300 tree saved_lhs0
= NULL_TREE
;
2301 if (handled_component_p (lhs
))
2303 saved_lhs0
= TREE_OPERAND (lhs
, 0);
2304 TREE_OPERAND (lhs
, 0) = integer_zero_node
;
2308 /* Just compare the outermost handled component, if
2309 they are equal we have found a possible common
2311 tree saved_base0
= TREE_OPERAND (base
, 0);
2312 TREE_OPERAND (base
, 0) = integer_zero_node
;
2313 bool res
= operand_equal_p (lhs
, base
, 0);
2314 TREE_OPERAND (base
, 0) = saved_base0
;
2317 /* Otherwise drop handled components of the access. */
2320 while (handled_component_p (base
));
2322 TREE_OPERAND (lhs
, 0) = saved_lhs0
;
2324 /* Finally check if the lhs has the same address and size as the
2325 base candidate of the access. */
2327 || (((TYPE_SIZE (TREE_TYPE (lhs
))
2328 == TYPE_SIZE (TREE_TYPE (base
)))
2329 || (TYPE_SIZE (TREE_TYPE (lhs
))
2330 && TYPE_SIZE (TREE_TYPE (base
))
2331 && operand_equal_p (TYPE_SIZE (TREE_TYPE (lhs
)),
2332 TYPE_SIZE (TREE_TYPE (base
)), 0)))
2333 && operand_equal_p (lhs
, base
, OEP_ADDRESS_OF
)))
2337 /* Now look for non-literal equal bases with the restriction of
2338 handling constant offset and size. */
2339 /* For a must-alias check we need to be able to constrain
2340 the access properly. */
2341 if (ref
->max_size
== -1)
2343 HOST_WIDE_INT size
, offset
, max_size
, ref_offset
= ref
->offset
;
2346 = get_ref_base_and_extent (lhs
, &offset
, &size
, &max_size
, &reverse
);
2347 /* We can get MEM[symbol: sZ, index: D.8862_1] here,
2348 so base == ref->base does not always hold. */
2349 if (base
!= ref
->base
)
2351 /* If both base and ref->base are MEM_REFs, only compare the
2352 first operand, and if the second operand isn't equal constant,
2353 try to add the offsets into offset and ref_offset. */
2354 if (TREE_CODE (base
) == MEM_REF
&& TREE_CODE (ref
->base
) == MEM_REF
2355 && TREE_OPERAND (base
, 0) == TREE_OPERAND (ref
->base
, 0))
2357 if (!tree_int_cst_equal (TREE_OPERAND (base
, 1),
2358 TREE_OPERAND (ref
->base
, 1)))
2360 offset_int off1
= mem_ref_offset (base
);
2361 off1
= wi::lshift (off1
, LOG2_BITS_PER_UNIT
);
2363 offset_int off2
= mem_ref_offset (ref
->base
);
2364 off2
= wi::lshift (off2
, LOG2_BITS_PER_UNIT
);
2366 if (wi::fits_shwi_p (off1
) && wi::fits_shwi_p (off2
))
2368 offset
= off1
.to_shwi ();
2369 ref_offset
= off2
.to_shwi ();
2378 /* For a must-alias check we need to be able to constrain
2379 the access properly. */
2380 if (size
!= -1 && size
== max_size
)
2382 if (offset
<= ref_offset
2383 && offset
+ size
>= ref_offset
+ ref
->max_size
)
2388 if (is_gimple_call (stmt
))
2390 tree callee
= gimple_call_fndecl (stmt
);
2391 if (callee
!= NULL_TREE
2392 && gimple_call_builtin_p (stmt
, BUILT_IN_NORMAL
))
2393 switch (DECL_FUNCTION_CODE (callee
))
2397 tree ptr
= gimple_call_arg (stmt
, 0);
2398 tree base
= ao_ref_base (ref
);
2399 if (base
&& TREE_CODE (base
) == MEM_REF
2400 && TREE_OPERAND (base
, 0) == ptr
)
2405 case BUILT_IN_MEMCPY
:
2406 case BUILT_IN_MEMPCPY
:
2407 case BUILT_IN_MEMMOVE
:
2408 case BUILT_IN_MEMSET
:
2409 case BUILT_IN_MEMCPY_CHK
:
2410 case BUILT_IN_MEMPCPY_CHK
:
2411 case BUILT_IN_MEMMOVE_CHK
:
2412 case BUILT_IN_MEMSET_CHK
:
2414 /* For a must-alias check we need to be able to constrain
2415 the access properly. */
2416 if (ref
->max_size
== -1)
2418 tree dest
= gimple_call_arg (stmt
, 0);
2419 tree len
= gimple_call_arg (stmt
, 2);
2420 if (!tree_fits_shwi_p (len
))
2422 tree rbase
= ref
->base
;
2423 offset_int roffset
= ref
->offset
;
2425 ao_ref_init_from_ptr_and_size (&dref
, dest
, len
);
2426 tree base
= ao_ref_base (&dref
);
2427 offset_int offset
= dref
.offset
;
2428 if (!base
|| dref
.size
== -1)
2430 if (TREE_CODE (base
) == MEM_REF
)
2432 if (TREE_CODE (rbase
) != MEM_REF
)
2434 // Compare pointers.
2435 offset
+= wi::lshift (mem_ref_offset (base
),
2436 LOG2_BITS_PER_UNIT
);
2437 roffset
+= wi::lshift (mem_ref_offset (rbase
),
2438 LOG2_BITS_PER_UNIT
);
2439 base
= TREE_OPERAND (base
, 0);
2440 rbase
= TREE_OPERAND (rbase
, 0);
2443 && offset
<= roffset
2444 && (roffset
+ ref
->max_size
2445 <= offset
+ wi::lshift (wi::to_offset (len
),
2446 LOG2_BITS_PER_UNIT
)))
2451 case BUILT_IN_VA_END
:
2453 tree ptr
= gimple_call_arg (stmt
, 0);
2454 if (TREE_CODE (ptr
) == ADDR_EXPR
)
2456 tree base
= ao_ref_base (ref
);
2457 if (TREE_OPERAND (ptr
, 0) == base
)
2470 stmt_kills_ref_p (gimple
*stmt
, tree ref
)
2473 ao_ref_init (&r
, ref
);
2474 return stmt_kills_ref_p (stmt
, &r
);
2478 /* Walk the virtual use-def chain of VUSE until hitting the virtual operand
2479 TARGET or a statement clobbering the memory reference REF in which
2480 case false is returned. The walk starts with VUSE, one argument of PHI. */
2483 maybe_skip_until (gimple
*phi
, tree target
, ao_ref
*ref
,
2484 tree vuse
, unsigned int *cnt
, bitmap
*visited
,
2485 bool abort_on_visited
,
2486 void *(*translate
)(ao_ref
*, tree
, void *, bool *),
2489 basic_block bb
= gimple_bb (phi
);
2492 *visited
= BITMAP_ALLOC (NULL
);
2494 bitmap_set_bit (*visited
, SSA_NAME_VERSION (PHI_RESULT (phi
)));
2496 /* Walk until we hit the target. */
2497 while (vuse
!= target
)
2499 gimple
*def_stmt
= SSA_NAME_DEF_STMT (vuse
);
2500 /* Recurse for PHI nodes. */
2501 if (gimple_code (def_stmt
) == GIMPLE_PHI
)
2503 /* An already visited PHI node ends the walk successfully. */
2504 if (bitmap_bit_p (*visited
, SSA_NAME_VERSION (PHI_RESULT (def_stmt
))))
2505 return !abort_on_visited
;
2506 vuse
= get_continuation_for_phi (def_stmt
, ref
, cnt
,
2507 visited
, abort_on_visited
,
2513 else if (gimple_nop_p (def_stmt
))
2517 /* A clobbering statement or the end of the IL ends it failing. */
2519 if (stmt_may_clobber_ref_p_1 (def_stmt
, ref
))
2521 bool disambiguate_only
= true;
2523 && (*translate
) (ref
, vuse
, data
, &disambiguate_only
) == NULL
)
2529 /* If we reach a new basic-block see if we already skipped it
2530 in a previous walk that ended successfully. */
2531 if (gimple_bb (def_stmt
) != bb
)
2533 if (!bitmap_set_bit (*visited
, SSA_NAME_VERSION (vuse
)))
2534 return !abort_on_visited
;
2535 bb
= gimple_bb (def_stmt
);
2537 vuse
= gimple_vuse (def_stmt
);
2542 /* For two PHI arguments ARG0 and ARG1 try to skip non-aliasing code
2543 until we hit the phi argument definition that dominates the other one.
2544 Return that, or NULL_TREE if there is no such definition. */
2547 get_continuation_for_phi_1 (gimple
*phi
, tree arg0
, tree arg1
,
2548 ao_ref
*ref
, unsigned int *cnt
,
2549 bitmap
*visited
, bool abort_on_visited
,
2550 void *(*translate
)(ao_ref
*, tree
, void *, bool *),
2553 gimple
*def0
= SSA_NAME_DEF_STMT (arg0
);
2554 gimple
*def1
= SSA_NAME_DEF_STMT (arg1
);
2559 else if (gimple_nop_p (def0
)
2560 || (!gimple_nop_p (def1
)
2561 && dominated_by_p (CDI_DOMINATORS
,
2562 gimple_bb (def1
), gimple_bb (def0
))))
2564 if (maybe_skip_until (phi
, arg0
, ref
, arg1
, cnt
,
2565 visited
, abort_on_visited
, translate
, data
))
2568 else if (gimple_nop_p (def1
)
2569 || dominated_by_p (CDI_DOMINATORS
,
2570 gimple_bb (def0
), gimple_bb (def1
)))
2572 if (maybe_skip_until (phi
, arg1
, ref
, arg0
, cnt
,
2573 visited
, abort_on_visited
, translate
, data
))
2576 /* Special case of a diamond:
2578 goto (cond) ? L1 : L2
2579 L1: store1 = ... #MEM_2 = vuse(MEM_1)
2581 L2: store2 = ... #MEM_3 = vuse(MEM_1)
2582 L3: MEM_4 = PHI<MEM_2, MEM_3>
2583 We were called with the PHI at L3, MEM_2 and MEM_3 don't
2584 dominate each other, but still we can easily skip this PHI node
2585 if we recognize that the vuse MEM operand is the same for both,
2586 and that we can skip both statements (they don't clobber us).
2587 This is still linear. Don't use maybe_skip_until, that might
2588 potentially be slow. */
2589 else if ((common_vuse
= gimple_vuse (def0
))
2590 && common_vuse
== gimple_vuse (def1
))
2592 bool disambiguate_only
= true;
2594 if ((!stmt_may_clobber_ref_p_1 (def0
, ref
)
2596 && (*translate
) (ref
, arg0
, data
, &disambiguate_only
) == NULL
))
2597 && (!stmt_may_clobber_ref_p_1 (def1
, ref
)
2599 && (*translate
) (ref
, arg1
, data
, &disambiguate_only
) == NULL
)))
2607 /* Starting from a PHI node for the virtual operand of the memory reference
2608 REF find a continuation virtual operand that allows to continue walking
2609 statements dominating PHI skipping only statements that cannot possibly
2610 clobber REF. Increments *CNT for each alias disambiguation done.
2611 Returns NULL_TREE if no suitable virtual operand can be found. */
2614 get_continuation_for_phi (gimple
*phi
, ao_ref
*ref
,
2615 unsigned int *cnt
, bitmap
*visited
,
2616 bool abort_on_visited
,
2617 void *(*translate
)(ao_ref
*, tree
, void *, bool *),
2620 unsigned nargs
= gimple_phi_num_args (phi
);
2622 /* Through a single-argument PHI we can simply look through. */
2624 return PHI_ARG_DEF (phi
, 0);
2626 /* For two or more arguments try to pairwise skip non-aliasing code
2627 until we hit the phi argument definition that dominates the other one. */
2628 else if (nargs
>= 2)
2633 /* Find a candidate for the virtual operand which definition
2634 dominates those of all others. */
2635 arg0
= PHI_ARG_DEF (phi
, 0);
2636 if (!SSA_NAME_IS_DEFAULT_DEF (arg0
))
2637 for (i
= 1; i
< nargs
; ++i
)
2639 arg1
= PHI_ARG_DEF (phi
, i
);
2640 if (SSA_NAME_IS_DEFAULT_DEF (arg1
))
2645 if (dominated_by_p (CDI_DOMINATORS
,
2646 gimple_bb (SSA_NAME_DEF_STMT (arg0
)),
2647 gimple_bb (SSA_NAME_DEF_STMT (arg1
))))
2651 /* Then pairwise reduce against the found candidate. */
2652 for (i
= 0; i
< nargs
; ++i
)
2654 arg1
= PHI_ARG_DEF (phi
, i
);
2655 arg0
= get_continuation_for_phi_1 (phi
, arg0
, arg1
, ref
,
2656 cnt
, visited
, abort_on_visited
,
2668 /* Based on the memory reference REF and its virtual use VUSE call
2669 WALKER for each virtual use that is equivalent to VUSE, including VUSE
2670 itself. That is, for each virtual use for which its defining statement
2671 does not clobber REF.
2673 WALKER is called with REF, the current virtual use and DATA. If
2674 WALKER returns non-NULL the walk stops and its result is returned.
2675 At the end of a non-successful walk NULL is returned.
2677 TRANSLATE if non-NULL is called with a pointer to REF, the virtual
2678 use which definition is a statement that may clobber REF and DATA.
2679 If TRANSLATE returns (void *)-1 the walk stops and NULL is returned.
2680 If TRANSLATE returns non-NULL the walk stops and its result is returned.
2681 If TRANSLATE returns NULL the walk continues and TRANSLATE is supposed
2682 to adjust REF and *DATA to make that valid.
2684 VALUEIZE if non-NULL is called with the next VUSE that is considered
2685 and return value is substituted for that. This can be used to
2686 implement optimistic value-numbering for example. Note that the
2687 VUSE argument is assumed to be valueized already.
2689 TODO: Cache the vector of equivalent vuses per ref, vuse pair. */
2692 walk_non_aliased_vuses (ao_ref
*ref
, tree vuse
,
2693 void *(*walker
)(ao_ref
*, tree
, unsigned int, void *),
2694 void *(*translate
)(ao_ref
*, tree
, void *, bool *),
2695 tree (*valueize
)(tree
),
2698 bitmap visited
= NULL
;
2700 unsigned int cnt
= 0;
2701 bool translated
= false;
2703 timevar_push (TV_ALIAS_STMT_WALK
);
2709 /* ??? Do we want to account this to TV_ALIAS_STMT_WALK? */
2710 res
= (*walker
) (ref
, vuse
, cnt
, data
);
2712 if (res
== (void *)-1)
2717 /* Lookup succeeded. */
2718 else if (res
!= NULL
)
2722 vuse
= valueize (vuse
);
2723 def_stmt
= SSA_NAME_DEF_STMT (vuse
);
2724 if (gimple_nop_p (def_stmt
))
2726 else if (gimple_code (def_stmt
) == GIMPLE_PHI
)
2727 vuse
= get_continuation_for_phi (def_stmt
, ref
, &cnt
,
2728 &visited
, translated
, translate
, data
);
2732 if (stmt_may_clobber_ref_p_1 (def_stmt
, ref
))
2736 bool disambiguate_only
= false;
2737 res
= (*translate
) (ref
, vuse
, data
, &disambiguate_only
);
2738 /* Failed lookup and translation. */
2739 if (res
== (void *)-1)
2744 /* Lookup succeeded. */
2745 else if (res
!= NULL
)
2747 /* Translation succeeded, continue walking. */
2748 translated
= translated
|| !disambiguate_only
;
2750 vuse
= gimple_vuse (def_stmt
);
2756 BITMAP_FREE (visited
);
2758 timevar_pop (TV_ALIAS_STMT_WALK
);
2764 /* Based on the memory reference REF call WALKER for each vdef which
2765 defining statement may clobber REF, starting with VDEF. If REF
2766 is NULL_TREE, each defining statement is visited.
2768 WALKER is called with REF, the current vdef and DATA. If WALKER
2769 returns true the walk is stopped, otherwise it continues.
2771 If function entry is reached, FUNCTION_ENTRY_REACHED is set to true.
2772 The pointer may be NULL and then we do not track this information.
2774 At PHI nodes walk_aliased_vdefs forks into one walk for reach
2775 PHI argument (but only one walk continues on merge points), the
2776 return value is true if any of the walks was successful.
2778 The function returns the number of statements walked. */
2781 walk_aliased_vdefs_1 (ao_ref
*ref
, tree vdef
,
2782 bool (*walker
)(ao_ref
*, tree
, void *), void *data
,
2783 bitmap
*visited
, unsigned int cnt
,
2784 bool *function_entry_reached
)
2788 gimple
*def_stmt
= SSA_NAME_DEF_STMT (vdef
);
2791 && !bitmap_set_bit (*visited
, SSA_NAME_VERSION (vdef
)))
2794 if (gimple_nop_p (def_stmt
))
2796 if (function_entry_reached
)
2797 *function_entry_reached
= true;
2800 else if (gimple_code (def_stmt
) == GIMPLE_PHI
)
2804 *visited
= BITMAP_ALLOC (NULL
);
2805 for (i
= 0; i
< gimple_phi_num_args (def_stmt
); ++i
)
2806 cnt
+= walk_aliased_vdefs_1 (ref
, gimple_phi_arg_def (def_stmt
, i
),
2807 walker
, data
, visited
, 0,
2808 function_entry_reached
);
2812 /* ??? Do we want to account this to TV_ALIAS_STMT_WALK? */
2815 || stmt_may_clobber_ref_p_1 (def_stmt
, ref
))
2816 && (*walker
) (ref
, vdef
, data
))
2819 vdef
= gimple_vuse (def_stmt
);
2825 walk_aliased_vdefs (ao_ref
*ref
, tree vdef
,
2826 bool (*walker
)(ao_ref
*, tree
, void *), void *data
,
2828 bool *function_entry_reached
)
2830 bitmap local_visited
= NULL
;
2833 timevar_push (TV_ALIAS_STMT_WALK
);
2835 if (function_entry_reached
)
2836 *function_entry_reached
= false;
2838 ret
= walk_aliased_vdefs_1 (ref
, vdef
, walker
, data
,
2839 visited
? visited
: &local_visited
, 0,
2840 function_entry_reached
);
2842 BITMAP_FREE (local_visited
);
2844 timevar_pop (TV_ALIAS_STMT_WALK
);