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
);
366 /* We may not use restrict to optimize pointer comparisons.
367 See PR71062. So we have to assume that restrict-pointed-to
368 may be in fact obj1. */
369 if (!pi
|| pi
->pt
.vars_contains_restrict
)
371 return !pt_solution_includes (&pi
->pt
, obj1
);
373 else if (TREE_CODE (ptr1
) == SSA_NAME
&& obj2
)
375 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (ptr1
);
376 if (!pi
|| pi
->pt
.vars_contains_restrict
)
378 return !pt_solution_includes (&pi
->pt
, obj2
);
381 /* ??? We'd like to handle ptr1 != NULL and ptr1 != ptr2
382 but those require pt.null to be conservatively correct. */
387 /* Returns whether reference REF to BASE may refer to global memory. */
390 ref_may_alias_global_p_1 (tree base
)
393 return is_global_var (base
);
394 else if (TREE_CODE (base
) == MEM_REF
395 || TREE_CODE (base
) == TARGET_MEM_REF
)
396 return ptr_deref_may_alias_global_p (TREE_OPERAND (base
, 0));
401 ref_may_alias_global_p (ao_ref
*ref
)
403 tree base
= ao_ref_base (ref
);
404 return ref_may_alias_global_p_1 (base
);
408 ref_may_alias_global_p (tree ref
)
410 tree base
= get_base_address (ref
);
411 return ref_may_alias_global_p_1 (base
);
414 /* Return true whether STMT may clobber global memory. */
417 stmt_may_clobber_global_p (gimple
*stmt
)
421 if (!gimple_vdef (stmt
))
424 /* ??? We can ask the oracle whether an artificial pointer
425 dereference with a pointer with points-to information covering
426 all global memory (what about non-address taken memory?) maybe
427 clobbered by this call. As there is at the moment no convenient
428 way of doing that without generating garbage do some manual
430 ??? We could make a NULL ao_ref argument to the various
431 predicates special, meaning any global memory. */
433 switch (gimple_code (stmt
))
436 lhs
= gimple_assign_lhs (stmt
);
437 return (TREE_CODE (lhs
) != SSA_NAME
438 && ref_may_alias_global_p (lhs
));
447 /* Dump alias information on FILE. */
450 dump_alias_info (FILE *file
)
454 = lang_hooks
.decl_printable_name (current_function_decl
, 2);
457 fprintf (file
, "\n\nAlias information for %s\n\n", funcname
);
459 fprintf (file
, "Aliased symbols\n\n");
461 FOR_EACH_LOCAL_DECL (cfun
, i
, var
)
463 if (may_be_aliased (var
))
464 dump_variable (file
, var
);
467 fprintf (file
, "\nCall clobber information\n");
469 fprintf (file
, "\nESCAPED");
470 dump_points_to_solution (file
, &cfun
->gimple_df
->escaped
);
472 fprintf (file
, "\n\nFlow-insensitive points-to information\n\n");
474 for (i
= 1; i
< num_ssa_names
; i
++)
476 tree ptr
= ssa_name (i
);
477 struct ptr_info_def
*pi
;
480 || !POINTER_TYPE_P (TREE_TYPE (ptr
))
481 || SSA_NAME_IN_FREE_LIST (ptr
))
484 pi
= SSA_NAME_PTR_INFO (ptr
);
486 dump_points_to_info_for (file
, ptr
);
489 fprintf (file
, "\n");
493 /* Dump alias information on stderr. */
496 debug_alias_info (void)
498 dump_alias_info (stderr
);
502 /* Dump the points-to set *PT into FILE. */
505 dump_points_to_solution (FILE *file
, struct pt_solution
*pt
)
508 fprintf (file
, ", points-to anything");
511 fprintf (file
, ", points-to non-local");
514 fprintf (file
, ", points-to escaped");
517 fprintf (file
, ", points-to unit escaped");
520 fprintf (file
, ", points-to NULL");
524 fprintf (file
, ", points-to vars: ");
525 dump_decl_set (file
, pt
->vars
);
526 if (pt
->vars_contains_nonlocal
527 || pt
->vars_contains_escaped
528 || pt
->vars_contains_escaped_heap
529 || pt
->vars_contains_restrict
)
531 const char *comma
= "";
532 fprintf (file
, " (");
533 if (pt
->vars_contains_nonlocal
)
535 fprintf (file
, "nonlocal");
538 if (pt
->vars_contains_escaped
)
540 fprintf (file
, "%sescaped", comma
);
543 if (pt
->vars_contains_escaped_heap
)
545 fprintf (file
, "%sescaped heap", comma
);
548 if (pt
->vars_contains_restrict
)
549 fprintf (file
, "%srestrict", comma
);
556 /* Unified dump function for pt_solution. */
559 debug (pt_solution
&ref
)
561 dump_points_to_solution (stderr
, &ref
);
565 debug (pt_solution
*ptr
)
570 fprintf (stderr
, "<nil>\n");
574 /* Dump points-to information for SSA_NAME PTR into FILE. */
577 dump_points_to_info_for (FILE *file
, tree ptr
)
579 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (ptr
);
581 print_generic_expr (file
, ptr
, dump_flags
);
584 dump_points_to_solution (file
, &pi
->pt
);
586 fprintf (file
, ", points-to anything");
588 fprintf (file
, "\n");
592 /* Dump points-to information for VAR into stderr. */
595 debug_points_to_info_for (tree var
)
597 dump_points_to_info_for (stderr
, var
);
601 /* Initializes the alias-oracle reference representation *R from REF. */
604 ao_ref_init (ao_ref
*r
, tree ref
)
611 r
->ref_alias_set
= -1;
612 r
->base_alias_set
= -1;
613 r
->volatile_p
= ref
? TREE_THIS_VOLATILE (ref
) : false;
616 /* Returns the base object of the memory reference *REF. */
619 ao_ref_base (ao_ref
*ref
)
625 ref
->base
= get_ref_base_and_extent (ref
->ref
, &ref
->offset
, &ref
->size
,
626 &ref
->max_size
, &reverse
);
630 /* Returns the base object alias set of the memory reference *REF. */
633 ao_ref_base_alias_set (ao_ref
*ref
)
636 if (ref
->base_alias_set
!= -1)
637 return ref
->base_alias_set
;
641 while (handled_component_p (base_ref
))
642 base_ref
= TREE_OPERAND (base_ref
, 0);
643 ref
->base_alias_set
= get_alias_set (base_ref
);
644 return ref
->base_alias_set
;
647 /* Returns the reference alias set of the memory reference *REF. */
650 ao_ref_alias_set (ao_ref
*ref
)
652 if (ref
->ref_alias_set
!= -1)
653 return ref
->ref_alias_set
;
654 ref
->ref_alias_set
= get_alias_set (ref
->ref
);
655 return ref
->ref_alias_set
;
658 /* Init an alias-oracle reference representation from a gimple pointer
659 PTR and a gimple size SIZE in bytes. If SIZE is NULL_TREE then the
660 size is assumed to be unknown. The access is assumed to be only
661 to or after of the pointer target, not before it. */
664 ao_ref_init_from_ptr_and_size (ao_ref
*ref
, tree ptr
, tree size
)
666 HOST_WIDE_INT t
, size_hwi
, extra_offset
= 0;
667 ref
->ref
= NULL_TREE
;
668 if (TREE_CODE (ptr
) == SSA_NAME
)
670 gimple
*stmt
= SSA_NAME_DEF_STMT (ptr
);
671 if (gimple_assign_single_p (stmt
)
672 && gimple_assign_rhs_code (stmt
) == ADDR_EXPR
)
673 ptr
= gimple_assign_rhs1 (stmt
);
674 else if (is_gimple_assign (stmt
)
675 && gimple_assign_rhs_code (stmt
) == POINTER_PLUS_EXPR
676 && TREE_CODE (gimple_assign_rhs2 (stmt
)) == INTEGER_CST
)
678 ptr
= gimple_assign_rhs1 (stmt
);
679 extra_offset
= BITS_PER_UNIT
680 * int_cst_value (gimple_assign_rhs2 (stmt
));
684 if (TREE_CODE (ptr
) == ADDR_EXPR
)
686 ref
->base
= get_addr_base_and_unit_offset (TREE_OPERAND (ptr
, 0), &t
);
688 ref
->offset
= BITS_PER_UNIT
* t
;
693 ref
->base
= get_base_address (TREE_OPERAND (ptr
, 0));
698 ref
->base
= build2 (MEM_REF
, char_type_node
,
699 ptr
, null_pointer_node
);
702 ref
->offset
+= extra_offset
;
704 && tree_fits_shwi_p (size
)
705 && (size_hwi
= tree_to_shwi (size
)) <= HOST_WIDE_INT_MAX
/ BITS_PER_UNIT
)
706 ref
->max_size
= ref
->size
= size_hwi
* BITS_PER_UNIT
;
708 ref
->max_size
= ref
->size
= -1;
709 ref
->ref_alias_set
= 0;
710 ref
->base_alias_set
= 0;
711 ref
->volatile_p
= false;
714 /* Return 1 if TYPE1 and TYPE2 are to be considered equivalent for the
715 purpose of TBAA. Return 0 if they are distinct and -1 if we cannot
719 same_type_for_tbaa (tree type1
, tree type2
)
721 type1
= TYPE_MAIN_VARIANT (type1
);
722 type2
= TYPE_MAIN_VARIANT (type2
);
724 /* If we would have to do structural comparison bail out. */
725 if (TYPE_STRUCTURAL_EQUALITY_P (type1
)
726 || TYPE_STRUCTURAL_EQUALITY_P (type2
))
729 /* Compare the canonical types. */
730 if (TYPE_CANONICAL (type1
) == TYPE_CANONICAL (type2
))
733 /* ??? Array types are not properly unified in all cases as we have
734 spurious changes in the index types for example. Removing this
735 causes all sorts of problems with the Fortran frontend. */
736 if (TREE_CODE (type1
) == ARRAY_TYPE
737 && TREE_CODE (type2
) == ARRAY_TYPE
)
740 /* ??? In Ada, an lvalue of an unconstrained type can be used to access an
741 object of one of its constrained subtypes, e.g. when a function with an
742 unconstrained parameter passed by reference is called on an object and
743 inlined. But, even in the case of a fixed size, type and subtypes are
744 not equivalent enough as to share the same TYPE_CANONICAL, since this
745 would mean that conversions between them are useless, whereas they are
746 not (e.g. type and subtypes can have different modes). So, in the end,
747 they are only guaranteed to have the same alias set. */
748 if (get_alias_set (type1
) == get_alias_set (type2
))
751 /* The types are known to be not equal. */
755 /* Determine if the two component references REF1 and REF2 which are
756 based on access types TYPE1 and TYPE2 and of which at least one is based
757 on an indirect reference may alias. REF2 is the only one that can
758 be a decl in which case REF2_IS_DECL is true.
759 REF1_ALIAS_SET, BASE1_ALIAS_SET, REF2_ALIAS_SET and BASE2_ALIAS_SET
760 are the respective alias sets. */
763 aliasing_component_refs_p (tree ref1
,
764 alias_set_type ref1_alias_set
,
765 alias_set_type base1_alias_set
,
766 HOST_WIDE_INT offset1
, HOST_WIDE_INT max_size1
,
768 alias_set_type ref2_alias_set
,
769 alias_set_type base2_alias_set
,
770 HOST_WIDE_INT offset2
, HOST_WIDE_INT max_size2
,
773 /* If one reference is a component references through pointers try to find a
774 common base and apply offset based disambiguation. This handles
776 struct A { int i; int j; } *q;
777 struct B { struct A a; int k; } *p;
778 disambiguating q->i and p->a.j. */
784 /* Choose bases and base types to search for. */
786 while (handled_component_p (base1
))
787 base1
= TREE_OPERAND (base1
, 0);
788 type1
= TREE_TYPE (base1
);
790 while (handled_component_p (base2
))
791 base2
= TREE_OPERAND (base2
, 0);
792 type2
= TREE_TYPE (base2
);
794 /* Now search for the type1 in the access path of ref2. This
795 would be a common base for doing offset based disambiguation on. */
797 while (handled_component_p (*refp
)
798 && same_type_for_tbaa (TREE_TYPE (*refp
), type1
) == 0)
799 refp
= &TREE_OPERAND (*refp
, 0);
800 same_p
= same_type_for_tbaa (TREE_TYPE (*refp
), type1
);
801 /* If we couldn't compare types we have to bail out. */
804 else if (same_p
== 1)
806 HOST_WIDE_INT offadj
, sztmp
, msztmp
;
808 get_ref_base_and_extent (*refp
, &offadj
, &sztmp
, &msztmp
, &reverse
);
810 get_ref_base_and_extent (base1
, &offadj
, &sztmp
, &msztmp
, &reverse
);
812 return ranges_overlap_p (offset1
, max_size1
, offset2
, max_size2
);
814 /* If we didn't find a common base, try the other way around. */
816 while (handled_component_p (*refp
)
817 && same_type_for_tbaa (TREE_TYPE (*refp
), type2
) == 0)
818 refp
= &TREE_OPERAND (*refp
, 0);
819 same_p
= same_type_for_tbaa (TREE_TYPE (*refp
), type2
);
820 /* If we couldn't compare types we have to bail out. */
823 else if (same_p
== 1)
825 HOST_WIDE_INT offadj
, sztmp
, msztmp
;
827 get_ref_base_and_extent (*refp
, &offadj
, &sztmp
, &msztmp
, &reverse
);
829 get_ref_base_and_extent (base2
, &offadj
, &sztmp
, &msztmp
, &reverse
);
831 return ranges_overlap_p (offset1
, max_size1
, offset2
, max_size2
);
834 /* If we have two type access paths B1.path1 and B2.path2 they may
835 only alias if either B1 is in B2.path2 or B2 is in B1.path1.
836 But we can still have a path that goes B1.path1...B2.path2 with
837 a part that we do not see. So we can only disambiguate now
838 if there is no B2 in the tail of path1 and no B1 on the
840 if (base1_alias_set
== ref2_alias_set
841 || alias_set_subset_of (base1_alias_set
, ref2_alias_set
))
843 /* If this is ptr vs. decl then we know there is no ptr ... decl path. */
845 return (base2_alias_set
== ref1_alias_set
846 || alias_set_subset_of (base2_alias_set
, ref1_alias_set
));
850 /* Return true if we can determine that component references REF1 and REF2,
851 that are within a common DECL, cannot overlap. */
854 nonoverlapping_component_refs_of_decl_p (tree ref1
, tree ref2
)
856 auto_vec
<tree
, 16> component_refs1
;
857 auto_vec
<tree
, 16> component_refs2
;
859 /* Create the stack of handled components for REF1. */
860 while (handled_component_p (ref1
))
862 component_refs1
.safe_push (ref1
);
863 ref1
= TREE_OPERAND (ref1
, 0);
865 if (TREE_CODE (ref1
) == MEM_REF
)
867 if (!integer_zerop (TREE_OPERAND (ref1
, 1)))
869 ref1
= TREE_OPERAND (TREE_OPERAND (ref1
, 0), 0);
872 /* Create the stack of handled components for REF2. */
873 while (handled_component_p (ref2
))
875 component_refs2
.safe_push (ref2
);
876 ref2
= TREE_OPERAND (ref2
, 0);
878 if (TREE_CODE (ref2
) == MEM_REF
)
880 if (!integer_zerop (TREE_OPERAND (ref2
, 1)))
882 ref2
= TREE_OPERAND (TREE_OPERAND (ref2
, 0), 0);
885 /* Bases must be either same or uncomparable. */
886 gcc_checking_assert (ref1
== ref2
887 || (DECL_P (ref1
) && DECL_P (ref2
)
888 && compare_base_decls (ref1
, ref2
) != 0));
890 /* Pop the stacks in parallel and examine the COMPONENT_REFs of the same
891 rank. This is sufficient because we start from the same DECL and you
892 cannot reference several fields at a time with COMPONENT_REFs (unlike
893 with ARRAY_RANGE_REFs for arrays) so you always need the same number
894 of them to access a sub-component, unless you're in a union, in which
895 case the return value will precisely be false. */
900 if (component_refs1
.is_empty ())
902 ref1
= component_refs1
.pop ();
904 while (!RECORD_OR_UNION_TYPE_P (TREE_TYPE (TREE_OPERAND (ref1
, 0))));
908 if (component_refs2
.is_empty ())
910 ref2
= component_refs2
.pop ();
912 while (!RECORD_OR_UNION_TYPE_P (TREE_TYPE (TREE_OPERAND (ref2
, 0))));
914 /* Beware of BIT_FIELD_REF. */
915 if (TREE_CODE (ref1
) != COMPONENT_REF
916 || TREE_CODE (ref2
) != COMPONENT_REF
)
919 tree field1
= TREE_OPERAND (ref1
, 1);
920 tree field2
= TREE_OPERAND (ref2
, 1);
922 /* ??? We cannot simply use the type of operand #0 of the refs here
923 as the Fortran compiler smuggles type punning into COMPONENT_REFs
924 for common blocks instead of using unions like everyone else. */
925 tree type1
= DECL_CONTEXT (field1
);
926 tree type2
= DECL_CONTEXT (field2
);
928 /* We cannot disambiguate fields in a union or qualified union. */
929 if (type1
!= type2
|| TREE_CODE (type1
) != RECORD_TYPE
)
932 if (field1
!= field2
)
934 component_refs1
.release ();
935 component_refs2
.release ();
936 /* A field and its representative need to be considered the
938 if (DECL_BIT_FIELD_REPRESENTATIVE (field1
) == field2
939 || DECL_BIT_FIELD_REPRESENTATIVE (field2
) == field1
)
941 /* Different fields of the same record type cannot overlap.
942 ??? Bitfields can overlap at RTL level so punt on them. */
943 if (DECL_BIT_FIELD (field1
) && DECL_BIT_FIELD (field2
))
950 component_refs1
.release ();
951 component_refs2
.release ();
955 /* qsort compare function to sort FIELD_DECLs after their
956 DECL_FIELD_CONTEXT TYPE_UID. */
959 ncr_compar (const void *field1_
, const void *field2_
)
961 const_tree field1
= *(const_tree
*) const_cast <void *>(field1_
);
962 const_tree field2
= *(const_tree
*) const_cast <void *>(field2_
);
963 unsigned int uid1
= TYPE_UID (DECL_FIELD_CONTEXT (field1
));
964 unsigned int uid2
= TYPE_UID (DECL_FIELD_CONTEXT (field2
));
967 else if (uid1
> uid2
)
972 /* Return true if we can determine that the fields referenced cannot
973 overlap for any pair of objects. */
976 nonoverlapping_component_refs_p (const_tree x
, const_tree y
)
978 if (!flag_strict_aliasing
980 || TREE_CODE (x
) != COMPONENT_REF
981 || TREE_CODE (y
) != COMPONENT_REF
)
984 auto_vec
<const_tree
, 16> fieldsx
;
985 while (TREE_CODE (x
) == COMPONENT_REF
)
987 tree field
= TREE_OPERAND (x
, 1);
988 tree type
= DECL_FIELD_CONTEXT (field
);
989 if (TREE_CODE (type
) == RECORD_TYPE
)
990 fieldsx
.safe_push (field
);
991 x
= TREE_OPERAND (x
, 0);
993 if (fieldsx
.length () == 0)
995 auto_vec
<const_tree
, 16> fieldsy
;
996 while (TREE_CODE (y
) == COMPONENT_REF
)
998 tree field
= TREE_OPERAND (y
, 1);
999 tree type
= DECL_FIELD_CONTEXT (field
);
1000 if (TREE_CODE (type
) == RECORD_TYPE
)
1001 fieldsy
.safe_push (TREE_OPERAND (y
, 1));
1002 y
= TREE_OPERAND (y
, 0);
1004 if (fieldsy
.length () == 0)
1007 /* Most common case first. */
1008 if (fieldsx
.length () == 1
1009 && fieldsy
.length () == 1)
1010 return ((DECL_FIELD_CONTEXT (fieldsx
[0])
1011 == DECL_FIELD_CONTEXT (fieldsy
[0]))
1012 && fieldsx
[0] != fieldsy
[0]
1013 && !(DECL_BIT_FIELD (fieldsx
[0]) && DECL_BIT_FIELD (fieldsy
[0])));
1015 if (fieldsx
.length () == 2)
1017 if (ncr_compar (&fieldsx
[0], &fieldsx
[1]) == 1)
1018 std::swap (fieldsx
[0], fieldsx
[1]);
1021 fieldsx
.qsort (ncr_compar
);
1023 if (fieldsy
.length () == 2)
1025 if (ncr_compar (&fieldsy
[0], &fieldsy
[1]) == 1)
1026 std::swap (fieldsy
[0], fieldsy
[1]);
1029 fieldsy
.qsort (ncr_compar
);
1031 unsigned i
= 0, j
= 0;
1034 const_tree fieldx
= fieldsx
[i
];
1035 const_tree fieldy
= fieldsy
[j
];
1036 tree typex
= DECL_FIELD_CONTEXT (fieldx
);
1037 tree typey
= DECL_FIELD_CONTEXT (fieldy
);
1040 /* We're left with accessing different fields of a structure,
1041 no possible overlap. */
1042 if (fieldx
!= fieldy
)
1044 /* A field and its representative need to be considered the
1046 if (DECL_BIT_FIELD_REPRESENTATIVE (fieldx
) == fieldy
1047 || DECL_BIT_FIELD_REPRESENTATIVE (fieldy
) == fieldx
)
1049 /* Different fields of the same record type cannot overlap.
1050 ??? Bitfields can overlap at RTL level so punt on them. */
1051 if (DECL_BIT_FIELD (fieldx
) && DECL_BIT_FIELD (fieldy
))
1056 if (TYPE_UID (typex
) < TYPE_UID (typey
))
1059 if (i
== fieldsx
.length ())
1065 if (j
== fieldsy
.length ())
1075 /* Return true if two memory references based on the variables BASE1
1076 and BASE2 constrained to [OFFSET1, OFFSET1 + MAX_SIZE1) and
1077 [OFFSET2, OFFSET2 + MAX_SIZE2) may alias. REF1 and REF2
1078 if non-NULL are the complete memory reference trees. */
1081 decl_refs_may_alias_p (tree ref1
, tree base1
,
1082 HOST_WIDE_INT offset1
, HOST_WIDE_INT max_size1
,
1083 tree ref2
, tree base2
,
1084 HOST_WIDE_INT offset2
, HOST_WIDE_INT max_size2
)
1086 gcc_checking_assert (DECL_P (base1
) && DECL_P (base2
));
1088 /* If both references are based on different variables, they cannot alias. */
1089 if (compare_base_decls (base1
, base2
) == 0)
1092 /* If both references are based on the same variable, they cannot alias if
1093 the accesses do not overlap. */
1094 if (!ranges_overlap_p (offset1
, max_size1
, offset2
, max_size2
))
1097 /* For components with variable position, the above test isn't sufficient,
1098 so we disambiguate component references manually. */
1100 && handled_component_p (ref1
) && handled_component_p (ref2
)
1101 && nonoverlapping_component_refs_of_decl_p (ref1
, ref2
))
1107 /* Return true if an indirect reference based on *PTR1 constrained
1108 to [OFFSET1, OFFSET1 + MAX_SIZE1) may alias a variable based on BASE2
1109 constrained to [OFFSET2, OFFSET2 + MAX_SIZE2). *PTR1 and BASE2 have
1110 the alias sets BASE1_ALIAS_SET and BASE2_ALIAS_SET which can be -1
1111 in which case they are computed on-demand. REF1 and REF2
1112 if non-NULL are the complete memory reference trees. */
1115 indirect_ref_may_alias_decl_p (tree ref1 ATTRIBUTE_UNUSED
, tree base1
,
1116 HOST_WIDE_INT offset1
,
1117 HOST_WIDE_INT max_size1 ATTRIBUTE_UNUSED
,
1118 alias_set_type ref1_alias_set
,
1119 alias_set_type base1_alias_set
,
1120 tree ref2 ATTRIBUTE_UNUSED
, tree base2
,
1121 HOST_WIDE_INT offset2
, HOST_WIDE_INT max_size2
,
1122 alias_set_type ref2_alias_set
,
1123 alias_set_type base2_alias_set
, bool tbaa_p
)
1126 tree ptrtype1
, dbase2
;
1127 HOST_WIDE_INT offset1p
= offset1
, offset2p
= offset2
;
1128 HOST_WIDE_INT doffset1
, doffset2
;
1130 gcc_checking_assert ((TREE_CODE (base1
) == MEM_REF
1131 || TREE_CODE (base1
) == TARGET_MEM_REF
)
1134 ptr1
= TREE_OPERAND (base1
, 0);
1136 /* The offset embedded in MEM_REFs can be negative. Bias them
1137 so that the resulting offset adjustment is positive. */
1138 offset_int moff
= mem_ref_offset (base1
);
1139 moff
<<= LOG2_BITS_PER_UNIT
;
1140 if (wi::neg_p (moff
))
1141 offset2p
+= (-moff
).to_short_addr ();
1143 offset1p
+= moff
.to_short_addr ();
1145 /* If only one reference is based on a variable, they cannot alias if
1146 the pointer access is beyond the extent of the variable access.
1147 (the pointer base cannot validly point to an offset less than zero
1149 ??? IVOPTs creates bases that do not honor this restriction,
1150 so do not apply this optimization for TARGET_MEM_REFs. */
1151 if (TREE_CODE (base1
) != TARGET_MEM_REF
1152 && !ranges_overlap_p (MAX (0, offset1p
), -1, offset2p
, max_size2
))
1154 /* They also cannot alias if the pointer may not point to the decl. */
1155 if (!ptr_deref_may_alias_decl_p (ptr1
, base2
))
1158 /* Disambiguations that rely on strict aliasing rules follow. */
1159 if (!flag_strict_aliasing
|| !tbaa_p
)
1162 ptrtype1
= TREE_TYPE (TREE_OPERAND (base1
, 1));
1164 /* If the alias set for a pointer access is zero all bets are off. */
1165 if (base1_alias_set
== 0)
1168 /* When we are trying to disambiguate an access with a pointer dereference
1169 as base versus one with a decl as base we can use both the size
1170 of the decl and its dynamic type for extra disambiguation.
1171 ??? We do not know anything about the dynamic type of the decl
1172 other than that its alias-set contains base2_alias_set as a subset
1173 which does not help us here. */
1174 /* As we know nothing useful about the dynamic type of the decl just
1175 use the usual conflict check rather than a subset test.
1176 ??? We could introduce -fvery-strict-aliasing when the language
1177 does not allow decls to have a dynamic type that differs from their
1178 static type. Then we can check
1179 !alias_set_subset_of (base1_alias_set, base2_alias_set) instead. */
1180 if (base1_alias_set
!= base2_alias_set
1181 && !alias_sets_conflict_p (base1_alias_set
, base2_alias_set
))
1183 /* If the size of the access relevant for TBAA through the pointer
1184 is bigger than the size of the decl we can't possibly access the
1185 decl via that pointer. */
1186 if (DECL_SIZE (base2
) && COMPLETE_TYPE_P (TREE_TYPE (ptrtype1
))
1187 && TREE_CODE (DECL_SIZE (base2
)) == INTEGER_CST
1188 && TREE_CODE (TYPE_SIZE (TREE_TYPE (ptrtype1
))) == INTEGER_CST
1189 /* ??? This in turn may run afoul when a decl of type T which is
1190 a member of union type U is accessed through a pointer to
1191 type U and sizeof T is smaller than sizeof U. */
1192 && TREE_CODE (TREE_TYPE (ptrtype1
)) != UNION_TYPE
1193 && TREE_CODE (TREE_TYPE (ptrtype1
)) != QUAL_UNION_TYPE
1194 && tree_int_cst_lt (DECL_SIZE (base2
), TYPE_SIZE (TREE_TYPE (ptrtype1
))))
1200 /* If the decl is accessed via a MEM_REF, reconstruct the base
1201 we can use for TBAA and an appropriately adjusted offset. */
1203 while (handled_component_p (dbase2
))
1204 dbase2
= TREE_OPERAND (dbase2
, 0);
1207 if (TREE_CODE (dbase2
) == MEM_REF
1208 || TREE_CODE (dbase2
) == TARGET_MEM_REF
)
1210 offset_int moff
= mem_ref_offset (dbase2
);
1211 moff
<<= LOG2_BITS_PER_UNIT
;
1212 if (wi::neg_p (moff
))
1213 doffset1
-= (-moff
).to_short_addr ();
1215 doffset2
-= moff
.to_short_addr ();
1218 /* If either reference is view-converted, give up now. */
1219 if (same_type_for_tbaa (TREE_TYPE (base1
), TREE_TYPE (ptrtype1
)) != 1
1220 || same_type_for_tbaa (TREE_TYPE (dbase2
), TREE_TYPE (base2
)) != 1)
1223 /* If both references are through the same type, they do not alias
1224 if the accesses do not overlap. This does extra disambiguation
1225 for mixed/pointer accesses but requires strict aliasing.
1226 For MEM_REFs we require that the component-ref offset we computed
1227 is relative to the start of the type which we ensure by
1228 comparing rvalue and access type and disregarding the constant
1230 if ((TREE_CODE (base1
) != TARGET_MEM_REF
1231 || (!TMR_INDEX (base1
) && !TMR_INDEX2 (base1
)))
1232 && same_type_for_tbaa (TREE_TYPE (base1
), TREE_TYPE (dbase2
)) == 1)
1233 return ranges_overlap_p (doffset1
, max_size1
, doffset2
, max_size2
);
1236 && nonoverlapping_component_refs_p (ref1
, ref2
))
1239 /* Do access-path based disambiguation. */
1241 && (handled_component_p (ref1
) || handled_component_p (ref2
)))
1242 return aliasing_component_refs_p (ref1
,
1243 ref1_alias_set
, base1_alias_set
,
1246 ref2_alias_set
, base2_alias_set
,
1247 offset2
, max_size2
, true);
1252 /* Return true if two indirect references based on *PTR1
1253 and *PTR2 constrained to [OFFSET1, OFFSET1 + MAX_SIZE1) and
1254 [OFFSET2, OFFSET2 + MAX_SIZE2) may alias. *PTR1 and *PTR2 have
1255 the alias sets BASE1_ALIAS_SET and BASE2_ALIAS_SET which can be -1
1256 in which case they are computed on-demand. REF1 and REF2
1257 if non-NULL are the complete memory reference trees. */
1260 indirect_refs_may_alias_p (tree ref1 ATTRIBUTE_UNUSED
, tree base1
,
1261 HOST_WIDE_INT offset1
, HOST_WIDE_INT max_size1
,
1262 alias_set_type ref1_alias_set
,
1263 alias_set_type base1_alias_set
,
1264 tree ref2 ATTRIBUTE_UNUSED
, tree base2
,
1265 HOST_WIDE_INT offset2
, HOST_WIDE_INT max_size2
,
1266 alias_set_type ref2_alias_set
,
1267 alias_set_type base2_alias_set
, bool tbaa_p
)
1271 tree ptrtype1
, ptrtype2
;
1273 gcc_checking_assert ((TREE_CODE (base1
) == MEM_REF
1274 || TREE_CODE (base1
) == TARGET_MEM_REF
)
1275 && (TREE_CODE (base2
) == MEM_REF
1276 || TREE_CODE (base2
) == TARGET_MEM_REF
));
1278 ptr1
= TREE_OPERAND (base1
, 0);
1279 ptr2
= TREE_OPERAND (base2
, 0);
1281 /* If both bases are based on pointers they cannot alias if they may not
1282 point to the same memory object or if they point to the same object
1283 and the accesses do not overlap. */
1284 if ((!cfun
|| gimple_in_ssa_p (cfun
))
1285 && operand_equal_p (ptr1
, ptr2
, 0)
1286 && (((TREE_CODE (base1
) != TARGET_MEM_REF
1287 || (!TMR_INDEX (base1
) && !TMR_INDEX2 (base1
)))
1288 && (TREE_CODE (base2
) != TARGET_MEM_REF
1289 || (!TMR_INDEX (base2
) && !TMR_INDEX2 (base2
))))
1290 || (TREE_CODE (base1
) == TARGET_MEM_REF
1291 && TREE_CODE (base2
) == TARGET_MEM_REF
1292 && (TMR_STEP (base1
) == TMR_STEP (base2
)
1293 || (TMR_STEP (base1
) && TMR_STEP (base2
)
1294 && operand_equal_p (TMR_STEP (base1
),
1295 TMR_STEP (base2
), 0)))
1296 && (TMR_INDEX (base1
) == TMR_INDEX (base2
)
1297 || (TMR_INDEX (base1
) && TMR_INDEX (base2
)
1298 && operand_equal_p (TMR_INDEX (base1
),
1299 TMR_INDEX (base2
), 0)))
1300 && (TMR_INDEX2 (base1
) == TMR_INDEX2 (base2
)
1301 || (TMR_INDEX2 (base1
) && TMR_INDEX2 (base2
)
1302 && operand_equal_p (TMR_INDEX2 (base1
),
1303 TMR_INDEX2 (base2
), 0))))))
1306 /* The offset embedded in MEM_REFs can be negative. Bias them
1307 so that the resulting offset adjustment is positive. */
1308 moff
= mem_ref_offset (base1
);
1309 moff
<<= LOG2_BITS_PER_UNIT
;
1310 if (wi::neg_p (moff
))
1311 offset2
+= (-moff
).to_short_addr ();
1313 offset1
+= moff
.to_shwi ();
1314 moff
= mem_ref_offset (base2
);
1315 moff
<<= LOG2_BITS_PER_UNIT
;
1316 if (wi::neg_p (moff
))
1317 offset1
+= (-moff
).to_short_addr ();
1319 offset2
+= moff
.to_short_addr ();
1320 return ranges_overlap_p (offset1
, max_size1
, offset2
, max_size2
);
1322 if (!ptr_derefs_may_alias_p (ptr1
, ptr2
))
1325 /* Disambiguations that rely on strict aliasing rules follow. */
1326 if (!flag_strict_aliasing
|| !tbaa_p
)
1329 ptrtype1
= TREE_TYPE (TREE_OPERAND (base1
, 1));
1330 ptrtype2
= TREE_TYPE (TREE_OPERAND (base2
, 1));
1332 /* If the alias set for a pointer access is zero all bets are off. */
1333 if (base1_alias_set
== 0
1334 || base2_alias_set
== 0)
1337 /* If both references are through the same type, they do not alias
1338 if the accesses do not overlap. This does extra disambiguation
1339 for mixed/pointer accesses but requires strict aliasing. */
1340 if ((TREE_CODE (base1
) != TARGET_MEM_REF
1341 || (!TMR_INDEX (base1
) && !TMR_INDEX2 (base1
)))
1342 && (TREE_CODE (base2
) != TARGET_MEM_REF
1343 || (!TMR_INDEX (base2
) && !TMR_INDEX2 (base2
)))
1344 && same_type_for_tbaa (TREE_TYPE (base1
), TREE_TYPE (ptrtype1
)) == 1
1345 && same_type_for_tbaa (TREE_TYPE (base2
), TREE_TYPE (ptrtype2
)) == 1
1346 && same_type_for_tbaa (TREE_TYPE (ptrtype1
),
1347 TREE_TYPE (ptrtype2
)) == 1)
1348 return ranges_overlap_p (offset1
, max_size1
, offset2
, max_size2
);
1350 /* Do type-based disambiguation. */
1351 if (base1_alias_set
!= base2_alias_set
1352 && !alias_sets_conflict_p (base1_alias_set
, base2_alias_set
))
1355 /* If either reference is view-converted, give up now. */
1356 if (same_type_for_tbaa (TREE_TYPE (base1
), TREE_TYPE (ptrtype1
)) != 1
1357 || same_type_for_tbaa (TREE_TYPE (base2
), TREE_TYPE (ptrtype2
)) != 1)
1361 && nonoverlapping_component_refs_p (ref1
, ref2
))
1364 /* Do access-path based disambiguation. */
1366 && (handled_component_p (ref1
) || handled_component_p (ref2
)))
1367 return aliasing_component_refs_p (ref1
,
1368 ref1_alias_set
, base1_alias_set
,
1371 ref2_alias_set
, base2_alias_set
,
1372 offset2
, max_size2
, false);
1377 /* Return true, if the two memory references REF1 and REF2 may alias. */
1380 refs_may_alias_p_1 (ao_ref
*ref1
, ao_ref
*ref2
, bool tbaa_p
)
1383 HOST_WIDE_INT offset1
= 0, offset2
= 0;
1384 HOST_WIDE_INT max_size1
= -1, max_size2
= -1;
1385 bool var1_p
, var2_p
, ind1_p
, ind2_p
;
1387 gcc_checking_assert ((!ref1
->ref
1388 || TREE_CODE (ref1
->ref
) == SSA_NAME
1389 || DECL_P (ref1
->ref
)
1390 || TREE_CODE (ref1
->ref
) == STRING_CST
1391 || handled_component_p (ref1
->ref
)
1392 || TREE_CODE (ref1
->ref
) == MEM_REF
1393 || TREE_CODE (ref1
->ref
) == TARGET_MEM_REF
)
1395 || TREE_CODE (ref2
->ref
) == SSA_NAME
1396 || DECL_P (ref2
->ref
)
1397 || TREE_CODE (ref2
->ref
) == STRING_CST
1398 || handled_component_p (ref2
->ref
)
1399 || TREE_CODE (ref2
->ref
) == MEM_REF
1400 || TREE_CODE (ref2
->ref
) == TARGET_MEM_REF
));
1402 /* Decompose the references into their base objects and the access. */
1403 base1
= ao_ref_base (ref1
);
1404 offset1
= ref1
->offset
;
1405 max_size1
= ref1
->max_size
;
1406 base2
= ao_ref_base (ref2
);
1407 offset2
= ref2
->offset
;
1408 max_size2
= ref2
->max_size
;
1410 /* We can end up with registers or constants as bases for example from
1411 *D.1663_44 = VIEW_CONVERT_EXPR<struct DB_LSN>(__tmp$B0F64_59);
1412 which is seen as a struct copy. */
1413 if (TREE_CODE (base1
) == SSA_NAME
1414 || TREE_CODE (base1
) == CONST_DECL
1415 || TREE_CODE (base1
) == CONSTRUCTOR
1416 || TREE_CODE (base1
) == ADDR_EXPR
1417 || CONSTANT_CLASS_P (base1
)
1418 || TREE_CODE (base2
) == SSA_NAME
1419 || TREE_CODE (base2
) == CONST_DECL
1420 || TREE_CODE (base2
) == CONSTRUCTOR
1421 || TREE_CODE (base2
) == ADDR_EXPR
1422 || CONSTANT_CLASS_P (base2
))
1425 /* We can end up referring to code via function and label decls.
1426 As we likely do not properly track code aliases conservatively
1428 if (TREE_CODE (base1
) == FUNCTION_DECL
1429 || TREE_CODE (base1
) == LABEL_DECL
1430 || TREE_CODE (base2
) == FUNCTION_DECL
1431 || TREE_CODE (base2
) == LABEL_DECL
)
1434 /* Two volatile accesses always conflict. */
1435 if (ref1
->volatile_p
1436 && ref2
->volatile_p
)
1439 /* Defer to simple offset based disambiguation if we have
1440 references based on two decls. Do this before defering to
1441 TBAA to handle must-alias cases in conformance with the
1442 GCC extension of allowing type-punning through unions. */
1443 var1_p
= DECL_P (base1
);
1444 var2_p
= DECL_P (base2
);
1445 if (var1_p
&& var2_p
)
1446 return decl_refs_may_alias_p (ref1
->ref
, base1
, offset1
, max_size1
,
1447 ref2
->ref
, base2
, offset2
, max_size2
);
1449 /* Handle restrict based accesses.
1450 ??? ao_ref_base strips inner MEM_REF [&decl], recover from that
1452 tree rbase1
= base1
;
1453 tree rbase2
= base2
;
1458 while (handled_component_p (rbase1
))
1459 rbase1
= TREE_OPERAND (rbase1
, 0);
1465 while (handled_component_p (rbase2
))
1466 rbase2
= TREE_OPERAND (rbase2
, 0);
1468 if (rbase1
&& rbase2
1469 && (TREE_CODE (base1
) == MEM_REF
|| TREE_CODE (base1
) == TARGET_MEM_REF
)
1470 && (TREE_CODE (base2
) == MEM_REF
|| TREE_CODE (base2
) == TARGET_MEM_REF
)
1471 /* If the accesses are in the same restrict clique... */
1472 && MR_DEPENDENCE_CLIQUE (base1
) == MR_DEPENDENCE_CLIQUE (base2
)
1473 /* But based on different pointers they do not alias. */
1474 && MR_DEPENDENCE_BASE (base1
) != MR_DEPENDENCE_BASE (base2
))
1477 ind1_p
= (TREE_CODE (base1
) == MEM_REF
1478 || TREE_CODE (base1
) == TARGET_MEM_REF
);
1479 ind2_p
= (TREE_CODE (base2
) == MEM_REF
1480 || TREE_CODE (base2
) == TARGET_MEM_REF
);
1482 /* Canonicalize the pointer-vs-decl case. */
1483 if (ind1_p
&& var2_p
)
1485 std::swap (offset1
, offset2
);
1486 std::swap (max_size1
, max_size2
);
1487 std::swap (base1
, base2
);
1488 std::swap (ref1
, ref2
);
1495 /* First defer to TBAA if possible. */
1497 && flag_strict_aliasing
1498 && !alias_sets_conflict_p (ao_ref_alias_set (ref1
),
1499 ao_ref_alias_set (ref2
)))
1502 /* Dispatch to the pointer-vs-decl or pointer-vs-pointer disambiguators. */
1503 if (var1_p
&& ind2_p
)
1504 return indirect_ref_may_alias_decl_p (ref2
->ref
, base2
,
1506 ao_ref_alias_set (ref2
),
1507 ao_ref_base_alias_set (ref2
),
1510 ao_ref_alias_set (ref1
),
1511 ao_ref_base_alias_set (ref1
),
1513 else if (ind1_p
&& ind2_p
)
1514 return indirect_refs_may_alias_p (ref1
->ref
, base1
,
1516 ao_ref_alias_set (ref1
),
1517 ao_ref_base_alias_set (ref1
),
1520 ao_ref_alias_set (ref2
),
1521 ao_ref_base_alias_set (ref2
),
1528 refs_may_alias_p (tree ref1
, ao_ref
*ref2
)
1531 ao_ref_init (&r1
, ref1
);
1532 return refs_may_alias_p_1 (&r1
, ref2
, true);
1536 refs_may_alias_p (tree ref1
, tree ref2
)
1540 ao_ref_init (&r1
, ref1
);
1541 ao_ref_init (&r2
, ref2
);
1542 res
= refs_may_alias_p_1 (&r1
, &r2
, true);
1544 ++alias_stats
.refs_may_alias_p_may_alias
;
1546 ++alias_stats
.refs_may_alias_p_no_alias
;
1550 /* Returns true if there is a anti-dependence for the STORE that
1551 executes after the LOAD. */
1554 refs_anti_dependent_p (tree load
, tree store
)
1557 ao_ref_init (&r1
, load
);
1558 ao_ref_init (&r2
, store
);
1559 return refs_may_alias_p_1 (&r1
, &r2
, false);
1562 /* Returns true if there is a output dependence for the stores
1563 STORE1 and STORE2. */
1566 refs_output_dependent_p (tree store1
, tree store2
)
1569 ao_ref_init (&r1
, store1
);
1570 ao_ref_init (&r2
, store2
);
1571 return refs_may_alias_p_1 (&r1
, &r2
, false);
1574 /* If the call CALL may use the memory reference REF return true,
1575 otherwise return false. */
1578 ref_maybe_used_by_call_p_1 (gcall
*call
, ao_ref
*ref
)
1582 int flags
= gimple_call_flags (call
);
1584 /* Const functions without a static chain do not implicitly use memory. */
1585 if (!gimple_call_chain (call
)
1586 && (flags
& (ECF_CONST
|ECF_NOVOPS
)))
1589 base
= ao_ref_base (ref
);
1593 /* A call that is not without side-effects might involve volatile
1594 accesses and thus conflicts with all other volatile accesses. */
1595 if (ref
->volatile_p
)
1598 /* If the reference is based on a decl that is not aliased the call
1599 cannot possibly use it. */
1601 && !may_be_aliased (base
)
1602 /* But local statics can be used through recursion. */
1603 && !is_global_var (base
))
1606 callee
= gimple_call_fndecl (call
);
1608 /* Handle those builtin functions explicitly that do not act as
1609 escape points. See tree-ssa-structalias.c:find_func_aliases
1610 for the list of builtins we might need to handle here. */
1611 if (callee
!= NULL_TREE
1612 && gimple_call_builtin_p (call
, BUILT_IN_NORMAL
))
1613 switch (DECL_FUNCTION_CODE (callee
))
1615 /* All the following functions read memory pointed to by
1616 their second argument. strcat/strncat additionally
1617 reads memory pointed to by the first argument. */
1618 case BUILT_IN_STRCAT
:
1619 case BUILT_IN_STRNCAT
:
1622 ao_ref_init_from_ptr_and_size (&dref
,
1623 gimple_call_arg (call
, 0),
1625 if (refs_may_alias_p_1 (&dref
, ref
, false))
1629 case BUILT_IN_STRCPY
:
1630 case BUILT_IN_STRNCPY
:
1631 case BUILT_IN_MEMCPY
:
1632 case BUILT_IN_MEMMOVE
:
1633 case BUILT_IN_MEMPCPY
:
1634 case BUILT_IN_STPCPY
:
1635 case BUILT_IN_STPNCPY
:
1636 case BUILT_IN_TM_MEMCPY
:
1637 case BUILT_IN_TM_MEMMOVE
:
1640 tree size
= NULL_TREE
;
1641 if (gimple_call_num_args (call
) == 3)
1642 size
= gimple_call_arg (call
, 2);
1643 ao_ref_init_from_ptr_and_size (&dref
,
1644 gimple_call_arg (call
, 1),
1646 return refs_may_alias_p_1 (&dref
, ref
, false);
1648 case BUILT_IN_STRCAT_CHK
:
1649 case BUILT_IN_STRNCAT_CHK
:
1652 ao_ref_init_from_ptr_and_size (&dref
,
1653 gimple_call_arg (call
, 0),
1655 if (refs_may_alias_p_1 (&dref
, ref
, false))
1659 case BUILT_IN_STRCPY_CHK
:
1660 case BUILT_IN_STRNCPY_CHK
:
1661 case BUILT_IN_MEMCPY_CHK
:
1662 case BUILT_IN_MEMMOVE_CHK
:
1663 case BUILT_IN_MEMPCPY_CHK
:
1664 case BUILT_IN_STPCPY_CHK
:
1665 case BUILT_IN_STPNCPY_CHK
:
1668 tree size
= NULL_TREE
;
1669 if (gimple_call_num_args (call
) == 4)
1670 size
= gimple_call_arg (call
, 2);
1671 ao_ref_init_from_ptr_and_size (&dref
,
1672 gimple_call_arg (call
, 1),
1674 return refs_may_alias_p_1 (&dref
, ref
, false);
1676 case BUILT_IN_BCOPY
:
1679 tree size
= gimple_call_arg (call
, 2);
1680 ao_ref_init_from_ptr_and_size (&dref
,
1681 gimple_call_arg (call
, 0),
1683 return refs_may_alias_p_1 (&dref
, ref
, false);
1686 /* The following functions read memory pointed to by their
1688 CASE_BUILT_IN_TM_LOAD (1):
1689 CASE_BUILT_IN_TM_LOAD (2):
1690 CASE_BUILT_IN_TM_LOAD (4):
1691 CASE_BUILT_IN_TM_LOAD (8):
1692 CASE_BUILT_IN_TM_LOAD (FLOAT
):
1693 CASE_BUILT_IN_TM_LOAD (DOUBLE
):
1694 CASE_BUILT_IN_TM_LOAD (LDOUBLE
):
1695 CASE_BUILT_IN_TM_LOAD (M64
):
1696 CASE_BUILT_IN_TM_LOAD (M128
):
1697 CASE_BUILT_IN_TM_LOAD (M256
):
1698 case BUILT_IN_TM_LOG
:
1699 case BUILT_IN_TM_LOG_1
:
1700 case BUILT_IN_TM_LOG_2
:
1701 case BUILT_IN_TM_LOG_4
:
1702 case BUILT_IN_TM_LOG_8
:
1703 case BUILT_IN_TM_LOG_FLOAT
:
1704 case BUILT_IN_TM_LOG_DOUBLE
:
1705 case BUILT_IN_TM_LOG_LDOUBLE
:
1706 case BUILT_IN_TM_LOG_M64
:
1707 case BUILT_IN_TM_LOG_M128
:
1708 case BUILT_IN_TM_LOG_M256
:
1709 return ptr_deref_may_alias_ref_p_1 (gimple_call_arg (call
, 0), ref
);
1711 /* These read memory pointed to by the first argument. */
1712 case BUILT_IN_STRDUP
:
1713 case BUILT_IN_STRNDUP
:
1714 case BUILT_IN_REALLOC
:
1717 tree size
= NULL_TREE
;
1718 if (gimple_call_num_args (call
) == 2)
1719 size
= gimple_call_arg (call
, 1);
1720 ao_ref_init_from_ptr_and_size (&dref
,
1721 gimple_call_arg (call
, 0),
1723 return refs_may_alias_p_1 (&dref
, ref
, false);
1725 /* These read memory pointed to by the first argument. */
1726 case BUILT_IN_INDEX
:
1727 case BUILT_IN_STRCHR
:
1728 case BUILT_IN_STRRCHR
:
1731 ao_ref_init_from_ptr_and_size (&dref
,
1732 gimple_call_arg (call
, 0),
1734 return refs_may_alias_p_1 (&dref
, ref
, false);
1736 /* These read memory pointed to by the first argument with size
1737 in the third argument. */
1738 case BUILT_IN_MEMCHR
:
1741 ao_ref_init_from_ptr_and_size (&dref
,
1742 gimple_call_arg (call
, 0),
1743 gimple_call_arg (call
, 2));
1744 return refs_may_alias_p_1 (&dref
, ref
, false);
1746 /* These read memory pointed to by the first and second arguments. */
1747 case BUILT_IN_STRSTR
:
1748 case BUILT_IN_STRPBRK
:
1751 ao_ref_init_from_ptr_and_size (&dref
,
1752 gimple_call_arg (call
, 0),
1754 if (refs_may_alias_p_1 (&dref
, ref
, false))
1756 ao_ref_init_from_ptr_and_size (&dref
,
1757 gimple_call_arg (call
, 1),
1759 return refs_may_alias_p_1 (&dref
, ref
, false);
1762 /* The following builtins do not read from memory. */
1764 case BUILT_IN_MALLOC
:
1765 case BUILT_IN_POSIX_MEMALIGN
:
1766 case BUILT_IN_ALIGNED_ALLOC
:
1767 case BUILT_IN_CALLOC
:
1768 case BUILT_IN_ALLOCA
:
1769 case BUILT_IN_ALLOCA_WITH_ALIGN
:
1770 case BUILT_IN_STACK_SAVE
:
1771 case BUILT_IN_STACK_RESTORE
:
1772 case BUILT_IN_MEMSET
:
1773 case BUILT_IN_TM_MEMSET
:
1774 case BUILT_IN_MEMSET_CHK
:
1775 case BUILT_IN_FREXP
:
1776 case BUILT_IN_FREXPF
:
1777 case BUILT_IN_FREXPL
:
1778 case BUILT_IN_GAMMA_R
:
1779 case BUILT_IN_GAMMAF_R
:
1780 case BUILT_IN_GAMMAL_R
:
1781 case BUILT_IN_LGAMMA_R
:
1782 case BUILT_IN_LGAMMAF_R
:
1783 case BUILT_IN_LGAMMAL_R
:
1785 case BUILT_IN_MODFF
:
1786 case BUILT_IN_MODFL
:
1787 case BUILT_IN_REMQUO
:
1788 case BUILT_IN_REMQUOF
:
1789 case BUILT_IN_REMQUOL
:
1790 case BUILT_IN_SINCOS
:
1791 case BUILT_IN_SINCOSF
:
1792 case BUILT_IN_SINCOSL
:
1793 case BUILT_IN_ASSUME_ALIGNED
:
1794 case BUILT_IN_VA_END
:
1796 /* __sync_* builtins and some OpenMP builtins act as threading
1798 #undef DEF_SYNC_BUILTIN
1799 #define DEF_SYNC_BUILTIN(ENUM, NAME, TYPE, ATTRS) case ENUM:
1800 #include "sync-builtins.def"
1801 #undef DEF_SYNC_BUILTIN
1802 case BUILT_IN_GOMP_ATOMIC_START
:
1803 case BUILT_IN_GOMP_ATOMIC_END
:
1804 case BUILT_IN_GOMP_BARRIER
:
1805 case BUILT_IN_GOMP_BARRIER_CANCEL
:
1806 case BUILT_IN_GOMP_TASKWAIT
:
1807 case BUILT_IN_GOMP_TASKGROUP_END
:
1808 case BUILT_IN_GOMP_CRITICAL_START
:
1809 case BUILT_IN_GOMP_CRITICAL_END
:
1810 case BUILT_IN_GOMP_CRITICAL_NAME_START
:
1811 case BUILT_IN_GOMP_CRITICAL_NAME_END
:
1812 case BUILT_IN_GOMP_LOOP_END
:
1813 case BUILT_IN_GOMP_LOOP_END_CANCEL
:
1814 case BUILT_IN_GOMP_ORDERED_START
:
1815 case BUILT_IN_GOMP_ORDERED_END
:
1816 case BUILT_IN_GOMP_SECTIONS_END
:
1817 case BUILT_IN_GOMP_SECTIONS_END_CANCEL
:
1818 case BUILT_IN_GOMP_SINGLE_COPY_START
:
1819 case BUILT_IN_GOMP_SINGLE_COPY_END
:
1823 /* Fallthru to general call handling. */;
1826 /* Check if base is a global static variable that is not read
1828 if (callee
!= NULL_TREE
1829 && TREE_CODE (base
) == VAR_DECL
1830 && TREE_STATIC (base
))
1832 struct cgraph_node
*node
= cgraph_node::get (callee
);
1835 /* FIXME: Callee can be an OMP builtin that does not have a call graph
1836 node yet. We should enforce that there are nodes for all decls in the
1837 IL and remove this check instead. */
1839 && (not_read
= ipa_reference_get_not_read_global (node
))
1840 && bitmap_bit_p (not_read
, ipa_reference_var_uid (base
)))
1844 /* Check if the base variable is call-used. */
1847 if (pt_solution_includes (gimple_call_use_set (call
), base
))
1850 else if ((TREE_CODE (base
) == MEM_REF
1851 || TREE_CODE (base
) == TARGET_MEM_REF
)
1852 && TREE_CODE (TREE_OPERAND (base
, 0)) == SSA_NAME
)
1854 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (TREE_OPERAND (base
, 0));
1858 if (pt_solutions_intersect (gimple_call_use_set (call
), &pi
->pt
))
1864 /* Inspect call arguments for passed-by-value aliases. */
1866 for (i
= 0; i
< gimple_call_num_args (call
); ++i
)
1868 tree op
= gimple_call_arg (call
, i
);
1869 int flags
= gimple_call_arg_flags (call
, i
);
1871 if (flags
& EAF_UNUSED
)
1874 if (TREE_CODE (op
) == WITH_SIZE_EXPR
)
1875 op
= TREE_OPERAND (op
, 0);
1877 if (TREE_CODE (op
) != SSA_NAME
1878 && !is_gimple_min_invariant (op
))
1881 ao_ref_init (&r
, op
);
1882 if (refs_may_alias_p_1 (&r
, ref
, true))
1891 ref_maybe_used_by_call_p (gcall
*call
, ao_ref
*ref
)
1894 res
= ref_maybe_used_by_call_p_1 (call
, ref
);
1896 ++alias_stats
.ref_maybe_used_by_call_p_may_alias
;
1898 ++alias_stats
.ref_maybe_used_by_call_p_no_alias
;
1903 /* If the statement STMT may use the memory reference REF return
1904 true, otherwise return false. */
1907 ref_maybe_used_by_stmt_p (gimple
*stmt
, ao_ref
*ref
)
1909 if (is_gimple_assign (stmt
))
1913 /* All memory assign statements are single. */
1914 if (!gimple_assign_single_p (stmt
))
1917 rhs
= gimple_assign_rhs1 (stmt
);
1918 if (is_gimple_reg (rhs
)
1919 || is_gimple_min_invariant (rhs
)
1920 || gimple_assign_rhs_code (stmt
) == CONSTRUCTOR
)
1923 return refs_may_alias_p (rhs
, ref
);
1925 else if (is_gimple_call (stmt
))
1926 return ref_maybe_used_by_call_p (as_a
<gcall
*> (stmt
), ref
);
1927 else if (greturn
*return_stmt
= dyn_cast
<greturn
*> (stmt
))
1929 tree retval
= gimple_return_retval (return_stmt
);
1931 && TREE_CODE (retval
) != SSA_NAME
1932 && !is_gimple_min_invariant (retval
)
1933 && refs_may_alias_p (retval
, ref
))
1935 /* If ref escapes the function then the return acts as a use. */
1936 tree base
= ao_ref_base (ref
);
1939 else if (DECL_P (base
))
1940 return is_global_var (base
);
1941 else if (TREE_CODE (base
) == MEM_REF
1942 || TREE_CODE (base
) == TARGET_MEM_REF
)
1943 return ptr_deref_may_alias_global_p (TREE_OPERAND (base
, 0));
1951 ref_maybe_used_by_stmt_p (gimple
*stmt
, tree ref
)
1954 ao_ref_init (&r
, ref
);
1955 return ref_maybe_used_by_stmt_p (stmt
, &r
);
1958 /* If the call in statement CALL may clobber the memory reference REF
1959 return true, otherwise return false. */
1962 call_may_clobber_ref_p_1 (gcall
*call
, ao_ref
*ref
)
1967 /* If the call is pure or const it cannot clobber anything. */
1968 if (gimple_call_flags (call
)
1969 & (ECF_PURE
|ECF_CONST
|ECF_LOOPING_CONST_OR_PURE
|ECF_NOVOPS
))
1971 if (gimple_call_internal_p (call
))
1972 switch (gimple_call_internal_fn (call
))
1974 /* Treat these internal calls like ECF_PURE for aliasing,
1975 they don't write to any memory the program should care about.
1976 They have important other side-effects, and read memory,
1977 so can't be ECF_NOVOPS. */
1978 case IFN_UBSAN_NULL
:
1979 case IFN_UBSAN_BOUNDS
:
1980 case IFN_UBSAN_VPTR
:
1981 case IFN_UBSAN_OBJECT_SIZE
:
1982 case IFN_ASAN_CHECK
:
1988 base
= ao_ref_base (ref
);
1992 if (TREE_CODE (base
) == SSA_NAME
1993 || CONSTANT_CLASS_P (base
))
1996 /* A call that is not without side-effects might involve volatile
1997 accesses and thus conflicts with all other volatile accesses. */
1998 if (ref
->volatile_p
)
2001 /* If the reference is based on a decl that is not aliased the call
2002 cannot possibly clobber it. */
2004 && !may_be_aliased (base
)
2005 /* But local non-readonly statics can be modified through recursion
2006 or the call may implement a threading barrier which we must
2007 treat as may-def. */
2008 && (TREE_READONLY (base
)
2009 || !is_global_var (base
)))
2012 callee
= gimple_call_fndecl (call
);
2014 /* Handle those builtin functions explicitly that do not act as
2015 escape points. See tree-ssa-structalias.c:find_func_aliases
2016 for the list of builtins we might need to handle here. */
2017 if (callee
!= NULL_TREE
2018 && gimple_call_builtin_p (call
, BUILT_IN_NORMAL
))
2019 switch (DECL_FUNCTION_CODE (callee
))
2021 /* All the following functions clobber memory pointed to by
2022 their first argument. */
2023 case BUILT_IN_STRCPY
:
2024 case BUILT_IN_STRNCPY
:
2025 case BUILT_IN_MEMCPY
:
2026 case BUILT_IN_MEMMOVE
:
2027 case BUILT_IN_MEMPCPY
:
2028 case BUILT_IN_STPCPY
:
2029 case BUILT_IN_STPNCPY
:
2030 case BUILT_IN_STRCAT
:
2031 case BUILT_IN_STRNCAT
:
2032 case BUILT_IN_MEMSET
:
2033 case BUILT_IN_TM_MEMSET
:
2034 CASE_BUILT_IN_TM_STORE (1):
2035 CASE_BUILT_IN_TM_STORE (2):
2036 CASE_BUILT_IN_TM_STORE (4):
2037 CASE_BUILT_IN_TM_STORE (8):
2038 CASE_BUILT_IN_TM_STORE (FLOAT
):
2039 CASE_BUILT_IN_TM_STORE (DOUBLE
):
2040 CASE_BUILT_IN_TM_STORE (LDOUBLE
):
2041 CASE_BUILT_IN_TM_STORE (M64
):
2042 CASE_BUILT_IN_TM_STORE (M128
):
2043 CASE_BUILT_IN_TM_STORE (M256
):
2044 case BUILT_IN_TM_MEMCPY
:
2045 case BUILT_IN_TM_MEMMOVE
:
2048 tree size
= NULL_TREE
;
2049 /* Don't pass in size for strncat, as the maximum size
2050 is strlen (dest) + n + 1 instead of n, resp.
2051 n + 1 at dest + strlen (dest), but strlen (dest) isn't
2053 if (gimple_call_num_args (call
) == 3
2054 && DECL_FUNCTION_CODE (callee
) != BUILT_IN_STRNCAT
)
2055 size
= gimple_call_arg (call
, 2);
2056 ao_ref_init_from_ptr_and_size (&dref
,
2057 gimple_call_arg (call
, 0),
2059 return refs_may_alias_p_1 (&dref
, ref
, false);
2061 case BUILT_IN_STRCPY_CHK
:
2062 case BUILT_IN_STRNCPY_CHK
:
2063 case BUILT_IN_MEMCPY_CHK
:
2064 case BUILT_IN_MEMMOVE_CHK
:
2065 case BUILT_IN_MEMPCPY_CHK
:
2066 case BUILT_IN_STPCPY_CHK
:
2067 case BUILT_IN_STPNCPY_CHK
:
2068 case BUILT_IN_STRCAT_CHK
:
2069 case BUILT_IN_STRNCAT_CHK
:
2070 case BUILT_IN_MEMSET_CHK
:
2073 tree size
= NULL_TREE
;
2074 /* Don't pass in size for __strncat_chk, as the maximum size
2075 is strlen (dest) + n + 1 instead of n, resp.
2076 n + 1 at dest + strlen (dest), but strlen (dest) isn't
2078 if (gimple_call_num_args (call
) == 4
2079 && DECL_FUNCTION_CODE (callee
) != BUILT_IN_STRNCAT_CHK
)
2080 size
= gimple_call_arg (call
, 2);
2081 ao_ref_init_from_ptr_and_size (&dref
,
2082 gimple_call_arg (call
, 0),
2084 return refs_may_alias_p_1 (&dref
, ref
, false);
2086 case BUILT_IN_BCOPY
:
2089 tree size
= gimple_call_arg (call
, 2);
2090 ao_ref_init_from_ptr_and_size (&dref
,
2091 gimple_call_arg (call
, 1),
2093 return refs_may_alias_p_1 (&dref
, ref
, false);
2095 /* Allocating memory does not have any side-effects apart from
2096 being the definition point for the pointer. */
2097 case BUILT_IN_MALLOC
:
2098 case BUILT_IN_ALIGNED_ALLOC
:
2099 case BUILT_IN_CALLOC
:
2100 case BUILT_IN_STRDUP
:
2101 case BUILT_IN_STRNDUP
:
2102 /* Unix98 specifies that errno is set on allocation failure. */
2104 && targetm
.ref_may_alias_errno (ref
))
2107 case BUILT_IN_STACK_SAVE
:
2108 case BUILT_IN_ALLOCA
:
2109 case BUILT_IN_ALLOCA_WITH_ALIGN
:
2110 case BUILT_IN_ASSUME_ALIGNED
:
2112 /* But posix_memalign stores a pointer into the memory pointed to
2113 by its first argument. */
2114 case BUILT_IN_POSIX_MEMALIGN
:
2116 tree ptrptr
= gimple_call_arg (call
, 0);
2118 ao_ref_init_from_ptr_and_size (&dref
, ptrptr
,
2119 TYPE_SIZE_UNIT (ptr_type_node
));
2120 return (refs_may_alias_p_1 (&dref
, ref
, false)
2122 && targetm
.ref_may_alias_errno (ref
)));
2124 /* Freeing memory kills the pointed-to memory. More importantly
2125 the call has to serve as a barrier for moving loads and stores
2128 case BUILT_IN_VA_END
:
2130 tree ptr
= gimple_call_arg (call
, 0);
2131 return ptr_deref_may_alias_ref_p_1 (ptr
, ref
);
2133 /* Realloc serves both as allocation point and deallocation point. */
2134 case BUILT_IN_REALLOC
:
2136 tree ptr
= gimple_call_arg (call
, 0);
2137 /* Unix98 specifies that errno is set on allocation failure. */
2138 return ((flag_errno_math
2139 && targetm
.ref_may_alias_errno (ref
))
2140 || ptr_deref_may_alias_ref_p_1 (ptr
, ref
));
2142 case BUILT_IN_GAMMA_R
:
2143 case BUILT_IN_GAMMAF_R
:
2144 case BUILT_IN_GAMMAL_R
:
2145 case BUILT_IN_LGAMMA_R
:
2146 case BUILT_IN_LGAMMAF_R
:
2147 case BUILT_IN_LGAMMAL_R
:
2149 tree out
= gimple_call_arg (call
, 1);
2150 if (ptr_deref_may_alias_ref_p_1 (out
, ref
))
2152 if (flag_errno_math
)
2156 case BUILT_IN_FREXP
:
2157 case BUILT_IN_FREXPF
:
2158 case BUILT_IN_FREXPL
:
2160 case BUILT_IN_MODFF
:
2161 case BUILT_IN_MODFL
:
2163 tree out
= gimple_call_arg (call
, 1);
2164 return ptr_deref_may_alias_ref_p_1 (out
, ref
);
2166 case BUILT_IN_REMQUO
:
2167 case BUILT_IN_REMQUOF
:
2168 case BUILT_IN_REMQUOL
:
2170 tree out
= gimple_call_arg (call
, 2);
2171 if (ptr_deref_may_alias_ref_p_1 (out
, ref
))
2173 if (flag_errno_math
)
2177 case BUILT_IN_SINCOS
:
2178 case BUILT_IN_SINCOSF
:
2179 case BUILT_IN_SINCOSL
:
2181 tree sin
= gimple_call_arg (call
, 1);
2182 tree cos
= gimple_call_arg (call
, 2);
2183 return (ptr_deref_may_alias_ref_p_1 (sin
, ref
)
2184 || ptr_deref_may_alias_ref_p_1 (cos
, ref
));
2186 /* __sync_* builtins and some OpenMP builtins act as threading
2188 #undef DEF_SYNC_BUILTIN
2189 #define DEF_SYNC_BUILTIN(ENUM, NAME, TYPE, ATTRS) case ENUM:
2190 #include "sync-builtins.def"
2191 #undef DEF_SYNC_BUILTIN
2192 case BUILT_IN_GOMP_ATOMIC_START
:
2193 case BUILT_IN_GOMP_ATOMIC_END
:
2194 case BUILT_IN_GOMP_BARRIER
:
2195 case BUILT_IN_GOMP_BARRIER_CANCEL
:
2196 case BUILT_IN_GOMP_TASKWAIT
:
2197 case BUILT_IN_GOMP_TASKGROUP_END
:
2198 case BUILT_IN_GOMP_CRITICAL_START
:
2199 case BUILT_IN_GOMP_CRITICAL_END
:
2200 case BUILT_IN_GOMP_CRITICAL_NAME_START
:
2201 case BUILT_IN_GOMP_CRITICAL_NAME_END
:
2202 case BUILT_IN_GOMP_LOOP_END
:
2203 case BUILT_IN_GOMP_LOOP_END_CANCEL
:
2204 case BUILT_IN_GOMP_ORDERED_START
:
2205 case BUILT_IN_GOMP_ORDERED_END
:
2206 case BUILT_IN_GOMP_SECTIONS_END
:
2207 case BUILT_IN_GOMP_SECTIONS_END_CANCEL
:
2208 case BUILT_IN_GOMP_SINGLE_COPY_START
:
2209 case BUILT_IN_GOMP_SINGLE_COPY_END
:
2212 /* Fallthru to general call handling. */;
2215 /* Check if base is a global static variable that is not written
2217 if (callee
!= NULL_TREE
2218 && TREE_CODE (base
) == VAR_DECL
2219 && TREE_STATIC (base
))
2221 struct cgraph_node
*node
= cgraph_node::get (callee
);
2225 && (not_written
= ipa_reference_get_not_written_global (node
))
2226 && bitmap_bit_p (not_written
, ipa_reference_var_uid (base
)))
2230 /* Check if the base variable is call-clobbered. */
2232 return pt_solution_includes (gimple_call_clobber_set (call
), base
);
2233 else if ((TREE_CODE (base
) == MEM_REF
2234 || TREE_CODE (base
) == TARGET_MEM_REF
)
2235 && TREE_CODE (TREE_OPERAND (base
, 0)) == SSA_NAME
)
2237 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (TREE_OPERAND (base
, 0));
2241 return pt_solutions_intersect (gimple_call_clobber_set (call
), &pi
->pt
);
2247 /* If the call in statement CALL may clobber the memory reference REF
2248 return true, otherwise return false. */
2251 call_may_clobber_ref_p (gcall
*call
, tree ref
)
2255 ao_ref_init (&r
, ref
);
2256 res
= call_may_clobber_ref_p_1 (call
, &r
);
2258 ++alias_stats
.call_may_clobber_ref_p_may_alias
;
2260 ++alias_stats
.call_may_clobber_ref_p_no_alias
;
2265 /* If the statement STMT may clobber the memory reference REF return true,
2266 otherwise return false. */
2269 stmt_may_clobber_ref_p_1 (gimple
*stmt
, ao_ref
*ref
)
2271 if (is_gimple_call (stmt
))
2273 tree lhs
= gimple_call_lhs (stmt
);
2275 && TREE_CODE (lhs
) != SSA_NAME
)
2278 ao_ref_init (&r
, lhs
);
2279 if (refs_may_alias_p_1 (ref
, &r
, true))
2283 return call_may_clobber_ref_p_1 (as_a
<gcall
*> (stmt
), ref
);
2285 else if (gimple_assign_single_p (stmt
))
2287 tree lhs
= gimple_assign_lhs (stmt
);
2288 if (TREE_CODE (lhs
) != SSA_NAME
)
2291 ao_ref_init (&r
, lhs
);
2292 return refs_may_alias_p_1 (ref
, &r
, true);
2295 else if (gimple_code (stmt
) == GIMPLE_ASM
)
2302 stmt_may_clobber_ref_p (gimple
*stmt
, tree ref
)
2305 ao_ref_init (&r
, ref
);
2306 return stmt_may_clobber_ref_p_1 (stmt
, &r
);
2309 /* If STMT kills the memory reference REF return true, otherwise
2313 stmt_kills_ref_p (gimple
*stmt
, ao_ref
*ref
)
2315 if (!ao_ref_base (ref
))
2318 if (gimple_has_lhs (stmt
)
2319 && TREE_CODE (gimple_get_lhs (stmt
)) != SSA_NAME
2320 /* The assignment is not necessarily carried out if it can throw
2321 and we can catch it in the current function where we could inspect
2323 ??? We only need to care about the RHS throwing. For aggregate
2324 assignments or similar calls and non-call exceptions the LHS
2325 might throw as well. */
2326 && !stmt_can_throw_internal (stmt
))
2328 tree lhs
= gimple_get_lhs (stmt
);
2329 /* If LHS is literally a base of the access we are done. */
2332 tree base
= ref
->ref
;
2333 if (handled_component_p (base
))
2335 tree saved_lhs0
= NULL_TREE
;
2336 if (handled_component_p (lhs
))
2338 saved_lhs0
= TREE_OPERAND (lhs
, 0);
2339 TREE_OPERAND (lhs
, 0) = integer_zero_node
;
2343 /* Just compare the outermost handled component, if
2344 they are equal we have found a possible common
2346 tree saved_base0
= TREE_OPERAND (base
, 0);
2347 TREE_OPERAND (base
, 0) = integer_zero_node
;
2348 bool res
= operand_equal_p (lhs
, base
, 0);
2349 TREE_OPERAND (base
, 0) = saved_base0
;
2352 /* Otherwise drop handled components of the access. */
2355 while (handled_component_p (base
));
2357 TREE_OPERAND (lhs
, 0) = saved_lhs0
;
2359 /* Finally check if the lhs has the same address and size as the
2360 base candidate of the access. */
2362 || (((TYPE_SIZE (TREE_TYPE (lhs
))
2363 == TYPE_SIZE (TREE_TYPE (base
)))
2364 || (TYPE_SIZE (TREE_TYPE (lhs
))
2365 && TYPE_SIZE (TREE_TYPE (base
))
2366 && operand_equal_p (TYPE_SIZE (TREE_TYPE (lhs
)),
2367 TYPE_SIZE (TREE_TYPE (base
)), 0)))
2368 && operand_equal_p (lhs
, base
, OEP_ADDRESS_OF
)))
2372 /* Now look for non-literal equal bases with the restriction of
2373 handling constant offset and size. */
2374 /* For a must-alias check we need to be able to constrain
2375 the access properly. */
2376 if (ref
->max_size
== -1)
2378 HOST_WIDE_INT size
, offset
, max_size
, ref_offset
= ref
->offset
;
2381 = get_ref_base_and_extent (lhs
, &offset
, &size
, &max_size
, &reverse
);
2382 /* We can get MEM[symbol: sZ, index: D.8862_1] here,
2383 so base == ref->base does not always hold. */
2384 if (base
!= ref
->base
)
2386 /* If both base and ref->base are MEM_REFs, only compare the
2387 first operand, and if the second operand isn't equal constant,
2388 try to add the offsets into offset and ref_offset. */
2389 if (TREE_CODE (base
) == MEM_REF
&& TREE_CODE (ref
->base
) == MEM_REF
2390 && TREE_OPERAND (base
, 0) == TREE_OPERAND (ref
->base
, 0))
2392 if (!tree_int_cst_equal (TREE_OPERAND (base
, 1),
2393 TREE_OPERAND (ref
->base
, 1)))
2395 offset_int off1
= mem_ref_offset (base
);
2396 off1
<<= LOG2_BITS_PER_UNIT
;
2398 offset_int off2
= mem_ref_offset (ref
->base
);
2399 off2
<<= LOG2_BITS_PER_UNIT
;
2401 if (wi::fits_shwi_p (off1
) && wi::fits_shwi_p (off2
))
2403 offset
= off1
.to_shwi ();
2404 ref_offset
= off2
.to_shwi ();
2413 /* For a must-alias check we need to be able to constrain
2414 the access properly. */
2415 if (size
!= -1 && size
== max_size
)
2417 if (offset
<= ref_offset
2418 && offset
+ size
>= ref_offset
+ ref
->max_size
)
2423 if (is_gimple_call (stmt
))
2425 tree callee
= gimple_call_fndecl (stmt
);
2426 if (callee
!= NULL_TREE
2427 && gimple_call_builtin_p (stmt
, BUILT_IN_NORMAL
))
2428 switch (DECL_FUNCTION_CODE (callee
))
2432 tree ptr
= gimple_call_arg (stmt
, 0);
2433 tree base
= ao_ref_base (ref
);
2434 if (base
&& TREE_CODE (base
) == MEM_REF
2435 && TREE_OPERAND (base
, 0) == ptr
)
2440 case BUILT_IN_MEMCPY
:
2441 case BUILT_IN_MEMPCPY
:
2442 case BUILT_IN_MEMMOVE
:
2443 case BUILT_IN_MEMSET
:
2444 case BUILT_IN_MEMCPY_CHK
:
2445 case BUILT_IN_MEMPCPY_CHK
:
2446 case BUILT_IN_MEMMOVE_CHK
:
2447 case BUILT_IN_MEMSET_CHK
:
2449 /* For a must-alias check we need to be able to constrain
2450 the access properly. */
2451 if (ref
->max_size
== -1)
2453 tree dest
= gimple_call_arg (stmt
, 0);
2454 tree len
= gimple_call_arg (stmt
, 2);
2455 if (!tree_fits_shwi_p (len
))
2457 tree rbase
= ref
->base
;
2458 offset_int roffset
= ref
->offset
;
2460 ao_ref_init_from_ptr_and_size (&dref
, dest
, len
);
2461 tree base
= ao_ref_base (&dref
);
2462 offset_int offset
= dref
.offset
;
2463 if (!base
|| dref
.size
== -1)
2465 if (TREE_CODE (base
) == MEM_REF
)
2467 if (TREE_CODE (rbase
) != MEM_REF
)
2469 // Compare pointers.
2470 offset
+= mem_ref_offset (base
) << LOG2_BITS_PER_UNIT
;
2471 roffset
+= mem_ref_offset (rbase
) << LOG2_BITS_PER_UNIT
;
2472 base
= TREE_OPERAND (base
, 0);
2473 rbase
= TREE_OPERAND (rbase
, 0);
2476 && offset
<= roffset
2477 && (roffset
+ ref
->max_size
2478 <= offset
+ (wi::to_offset (len
) << LOG2_BITS_PER_UNIT
)))
2483 case BUILT_IN_VA_END
:
2485 tree ptr
= gimple_call_arg (stmt
, 0);
2486 if (TREE_CODE (ptr
) == ADDR_EXPR
)
2488 tree base
= ao_ref_base (ref
);
2489 if (TREE_OPERAND (ptr
, 0) == base
)
2502 stmt_kills_ref_p (gimple
*stmt
, tree ref
)
2505 ao_ref_init (&r
, ref
);
2506 return stmt_kills_ref_p (stmt
, &r
);
2510 /* Walk the virtual use-def chain of VUSE until hitting the virtual operand
2511 TARGET or a statement clobbering the memory reference REF in which
2512 case false is returned. The walk starts with VUSE, one argument of PHI. */
2515 maybe_skip_until (gimple
*phi
, tree target
, ao_ref
*ref
,
2516 tree vuse
, unsigned int *cnt
, bitmap
*visited
,
2517 bool abort_on_visited
,
2518 void *(*translate
)(ao_ref
*, tree
, void *, bool *),
2521 basic_block bb
= gimple_bb (phi
);
2524 *visited
= BITMAP_ALLOC (NULL
);
2526 bitmap_set_bit (*visited
, SSA_NAME_VERSION (PHI_RESULT (phi
)));
2528 /* Walk until we hit the target. */
2529 while (vuse
!= target
)
2531 gimple
*def_stmt
= SSA_NAME_DEF_STMT (vuse
);
2532 /* Recurse for PHI nodes. */
2533 if (gimple_code (def_stmt
) == GIMPLE_PHI
)
2535 /* An already visited PHI node ends the walk successfully. */
2536 if (bitmap_bit_p (*visited
, SSA_NAME_VERSION (PHI_RESULT (def_stmt
))))
2537 return !abort_on_visited
;
2538 vuse
= get_continuation_for_phi (def_stmt
, ref
, cnt
,
2539 visited
, abort_on_visited
,
2545 else if (gimple_nop_p (def_stmt
))
2549 /* A clobbering statement or the end of the IL ends it failing. */
2551 if (stmt_may_clobber_ref_p_1 (def_stmt
, ref
))
2553 bool disambiguate_only
= true;
2555 && (*translate
) (ref
, vuse
, data
, &disambiguate_only
) == NULL
)
2561 /* If we reach a new basic-block see if we already skipped it
2562 in a previous walk that ended successfully. */
2563 if (gimple_bb (def_stmt
) != bb
)
2565 if (!bitmap_set_bit (*visited
, SSA_NAME_VERSION (vuse
)))
2566 return !abort_on_visited
;
2567 bb
= gimple_bb (def_stmt
);
2569 vuse
= gimple_vuse (def_stmt
);
2574 /* For two PHI arguments ARG0 and ARG1 try to skip non-aliasing code
2575 until we hit the phi argument definition that dominates the other one.
2576 Return that, or NULL_TREE if there is no such definition. */
2579 get_continuation_for_phi_1 (gimple
*phi
, tree arg0
, tree arg1
,
2580 ao_ref
*ref
, unsigned int *cnt
,
2581 bitmap
*visited
, bool abort_on_visited
,
2582 void *(*translate
)(ao_ref
*, tree
, void *, bool *),
2585 gimple
*def0
= SSA_NAME_DEF_STMT (arg0
);
2586 gimple
*def1
= SSA_NAME_DEF_STMT (arg1
);
2591 else if (gimple_nop_p (def0
)
2592 || (!gimple_nop_p (def1
)
2593 && dominated_by_p (CDI_DOMINATORS
,
2594 gimple_bb (def1
), gimple_bb (def0
))))
2596 if (maybe_skip_until (phi
, arg0
, ref
, arg1
, cnt
,
2597 visited
, abort_on_visited
, translate
, data
))
2600 else if (gimple_nop_p (def1
)
2601 || dominated_by_p (CDI_DOMINATORS
,
2602 gimple_bb (def0
), gimple_bb (def1
)))
2604 if (maybe_skip_until (phi
, arg1
, ref
, arg0
, cnt
,
2605 visited
, abort_on_visited
, translate
, data
))
2608 /* Special case of a diamond:
2610 goto (cond) ? L1 : L2
2611 L1: store1 = ... #MEM_2 = vuse(MEM_1)
2613 L2: store2 = ... #MEM_3 = vuse(MEM_1)
2614 L3: MEM_4 = PHI<MEM_2, MEM_3>
2615 We were called with the PHI at L3, MEM_2 and MEM_3 don't
2616 dominate each other, but still we can easily skip this PHI node
2617 if we recognize that the vuse MEM operand is the same for both,
2618 and that we can skip both statements (they don't clobber us).
2619 This is still linear. Don't use maybe_skip_until, that might
2620 potentially be slow. */
2621 else if ((common_vuse
= gimple_vuse (def0
))
2622 && common_vuse
== gimple_vuse (def1
))
2624 bool disambiguate_only
= true;
2626 if ((!stmt_may_clobber_ref_p_1 (def0
, ref
)
2628 && (*translate
) (ref
, arg0
, data
, &disambiguate_only
) == NULL
))
2629 && (!stmt_may_clobber_ref_p_1 (def1
, ref
)
2631 && (*translate
) (ref
, arg1
, data
, &disambiguate_only
) == NULL
)))
2639 /* Starting from a PHI node for the virtual operand of the memory reference
2640 REF find a continuation virtual operand that allows to continue walking
2641 statements dominating PHI skipping only statements that cannot possibly
2642 clobber REF. Increments *CNT for each alias disambiguation done.
2643 Returns NULL_TREE if no suitable virtual operand can be found. */
2646 get_continuation_for_phi (gimple
*phi
, ao_ref
*ref
,
2647 unsigned int *cnt
, bitmap
*visited
,
2648 bool abort_on_visited
,
2649 void *(*translate
)(ao_ref
*, tree
, void *, bool *),
2652 unsigned nargs
= gimple_phi_num_args (phi
);
2654 /* Through a single-argument PHI we can simply look through. */
2656 return PHI_ARG_DEF (phi
, 0);
2658 /* For two or more arguments try to pairwise skip non-aliasing code
2659 until we hit the phi argument definition that dominates the other one. */
2660 else if (nargs
>= 2)
2665 /* Find a candidate for the virtual operand which definition
2666 dominates those of all others. */
2667 arg0
= PHI_ARG_DEF (phi
, 0);
2668 if (!SSA_NAME_IS_DEFAULT_DEF (arg0
))
2669 for (i
= 1; i
< nargs
; ++i
)
2671 arg1
= PHI_ARG_DEF (phi
, i
);
2672 if (SSA_NAME_IS_DEFAULT_DEF (arg1
))
2677 if (dominated_by_p (CDI_DOMINATORS
,
2678 gimple_bb (SSA_NAME_DEF_STMT (arg0
)),
2679 gimple_bb (SSA_NAME_DEF_STMT (arg1
))))
2683 /* Then pairwise reduce against the found candidate. */
2684 for (i
= 0; i
< nargs
; ++i
)
2686 arg1
= PHI_ARG_DEF (phi
, i
);
2687 arg0
= get_continuation_for_phi_1 (phi
, arg0
, arg1
, ref
,
2688 cnt
, visited
, abort_on_visited
,
2700 /* Based on the memory reference REF and its virtual use VUSE call
2701 WALKER for each virtual use that is equivalent to VUSE, including VUSE
2702 itself. That is, for each virtual use for which its defining statement
2703 does not clobber REF.
2705 WALKER is called with REF, the current virtual use and DATA. If
2706 WALKER returns non-NULL the walk stops and its result is returned.
2707 At the end of a non-successful walk NULL is returned.
2709 TRANSLATE if non-NULL is called with a pointer to REF, the virtual
2710 use which definition is a statement that may clobber REF and DATA.
2711 If TRANSLATE returns (void *)-1 the walk stops and NULL is returned.
2712 If TRANSLATE returns non-NULL the walk stops and its result is returned.
2713 If TRANSLATE returns NULL the walk continues and TRANSLATE is supposed
2714 to adjust REF and *DATA to make that valid.
2716 VALUEIZE if non-NULL is called with the next VUSE that is considered
2717 and return value is substituted for that. This can be used to
2718 implement optimistic value-numbering for example. Note that the
2719 VUSE argument is assumed to be valueized already.
2721 TODO: Cache the vector of equivalent vuses per ref, vuse pair. */
2724 walk_non_aliased_vuses (ao_ref
*ref
, tree vuse
,
2725 void *(*walker
)(ao_ref
*, tree
, unsigned int, void *),
2726 void *(*translate
)(ao_ref
*, tree
, void *, bool *),
2727 tree (*valueize
)(tree
),
2730 bitmap visited
= NULL
;
2732 unsigned int cnt
= 0;
2733 bool translated
= false;
2735 timevar_push (TV_ALIAS_STMT_WALK
);
2741 /* ??? Do we want to account this to TV_ALIAS_STMT_WALK? */
2742 res
= (*walker
) (ref
, vuse
, cnt
, data
);
2744 if (res
== (void *)-1)
2749 /* Lookup succeeded. */
2750 else if (res
!= NULL
)
2754 vuse
= valueize (vuse
);
2755 def_stmt
= SSA_NAME_DEF_STMT (vuse
);
2756 if (gimple_nop_p (def_stmt
))
2758 else if (gimple_code (def_stmt
) == GIMPLE_PHI
)
2759 vuse
= get_continuation_for_phi (def_stmt
, ref
, &cnt
,
2760 &visited
, translated
, translate
, data
);
2764 if (stmt_may_clobber_ref_p_1 (def_stmt
, ref
))
2768 bool disambiguate_only
= false;
2769 res
= (*translate
) (ref
, vuse
, data
, &disambiguate_only
);
2770 /* Failed lookup and translation. */
2771 if (res
== (void *)-1)
2776 /* Lookup succeeded. */
2777 else if (res
!= NULL
)
2779 /* Translation succeeded, continue walking. */
2780 translated
= translated
|| !disambiguate_only
;
2782 vuse
= gimple_vuse (def_stmt
);
2788 BITMAP_FREE (visited
);
2790 timevar_pop (TV_ALIAS_STMT_WALK
);
2796 /* Based on the memory reference REF call WALKER for each vdef which
2797 defining statement may clobber REF, starting with VDEF. If REF
2798 is NULL_TREE, each defining statement is visited.
2800 WALKER is called with REF, the current vdef and DATA. If WALKER
2801 returns true the walk is stopped, otherwise it continues.
2803 If function entry is reached, FUNCTION_ENTRY_REACHED is set to true.
2804 The pointer may be NULL and then we do not track this information.
2806 At PHI nodes walk_aliased_vdefs forks into one walk for reach
2807 PHI argument (but only one walk continues on merge points), the
2808 return value is true if any of the walks was successful.
2810 The function returns the number of statements walked. */
2813 walk_aliased_vdefs_1 (ao_ref
*ref
, tree vdef
,
2814 bool (*walker
)(ao_ref
*, tree
, void *), void *data
,
2815 bitmap
*visited
, unsigned int cnt
,
2816 bool *function_entry_reached
)
2820 gimple
*def_stmt
= SSA_NAME_DEF_STMT (vdef
);
2823 && !bitmap_set_bit (*visited
, SSA_NAME_VERSION (vdef
)))
2826 if (gimple_nop_p (def_stmt
))
2828 if (function_entry_reached
)
2829 *function_entry_reached
= true;
2832 else if (gimple_code (def_stmt
) == GIMPLE_PHI
)
2836 *visited
= BITMAP_ALLOC (NULL
);
2837 for (i
= 0; i
< gimple_phi_num_args (def_stmt
); ++i
)
2838 cnt
+= walk_aliased_vdefs_1 (ref
, gimple_phi_arg_def (def_stmt
, i
),
2839 walker
, data
, visited
, 0,
2840 function_entry_reached
);
2844 /* ??? Do we want to account this to TV_ALIAS_STMT_WALK? */
2847 || stmt_may_clobber_ref_p_1 (def_stmt
, ref
))
2848 && (*walker
) (ref
, vdef
, data
))
2851 vdef
= gimple_vuse (def_stmt
);
2857 walk_aliased_vdefs (ao_ref
*ref
, tree vdef
,
2858 bool (*walker
)(ao_ref
*, tree
, void *), void *data
,
2860 bool *function_entry_reached
)
2862 bitmap local_visited
= NULL
;
2865 timevar_push (TV_ALIAS_STMT_WALK
);
2867 if (function_entry_reached
)
2868 *function_entry_reached
= false;
2870 ret
= walk_aliased_vdefs_1 (ref
, vdef
, walker
, data
,
2871 visited
? visited
: &local_visited
, 0,
2872 function_entry_reached
);
2874 BITMAP_FREE (local_visited
);
2876 timevar_pop (TV_ALIAS_STMT_WALK
);