1 /* Alias analysis for trees.
2 Copyright (C) 2004-2019 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"
35 #include "langhooks.h"
39 #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
))
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 cannot 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));
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));
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);
361 /* Canonicalize ptr vs. object. */
362 if (TREE_CODE (ptr1
) == SSA_NAME
&& obj2
)
364 std::swap (ptr1
, ptr2
);
365 std::swap (obj1
, obj2
);
369 /* Other code handles this correctly, no need to duplicate it here. */;
370 else if (obj1
&& TREE_CODE (ptr2
) == SSA_NAME
)
372 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (ptr2
);
373 /* We may not use restrict to optimize pointer comparisons.
374 See PR71062. So we have to assume that restrict-pointed-to
375 may be in fact obj1. */
377 || pi
->pt
.vars_contains_restrict
378 || pi
->pt
.vars_contains_interposable
)
381 && (TREE_STATIC (obj1
) || DECL_EXTERNAL (obj1
)))
383 varpool_node
*node
= varpool_node::get (obj1
);
384 /* If obj1 may bind to NULL give up (see below). */
386 || ! node
->nonzero_address ()
387 || ! decl_binds_to_current_def_p (obj1
))
390 return !pt_solution_includes (&pi
->pt
, obj1
);
393 /* ??? We'd like to handle ptr1 != NULL and ptr1 != ptr2
394 but those require pt.null to be conservatively correct. */
399 /* Returns whether reference REF to BASE may refer to global memory. */
402 ref_may_alias_global_p_1 (tree base
)
405 return is_global_var (base
);
406 else if (TREE_CODE (base
) == MEM_REF
407 || TREE_CODE (base
) == TARGET_MEM_REF
)
408 return ptr_deref_may_alias_global_p (TREE_OPERAND (base
, 0));
413 ref_may_alias_global_p (ao_ref
*ref
)
415 tree base
= ao_ref_base (ref
);
416 return ref_may_alias_global_p_1 (base
);
420 ref_may_alias_global_p (tree ref
)
422 tree base
= get_base_address (ref
);
423 return ref_may_alias_global_p_1 (base
);
426 /* Return true whether STMT may clobber global memory. */
429 stmt_may_clobber_global_p (gimple
*stmt
)
433 if (!gimple_vdef (stmt
))
436 /* ??? We can ask the oracle whether an artificial pointer
437 dereference with a pointer with points-to information covering
438 all global memory (what about non-address taken memory?) maybe
439 clobbered by this call. As there is at the moment no convenient
440 way of doing that without generating garbage do some manual
442 ??? We could make a NULL ao_ref argument to the various
443 predicates special, meaning any global memory. */
445 switch (gimple_code (stmt
))
448 lhs
= gimple_assign_lhs (stmt
);
449 return (TREE_CODE (lhs
) != SSA_NAME
450 && ref_may_alias_global_p (lhs
));
459 /* Dump alias information on FILE. */
462 dump_alias_info (FILE *file
)
467 = lang_hooks
.decl_printable_name (current_function_decl
, 2);
470 fprintf (file
, "\n\nAlias information for %s\n\n", funcname
);
472 fprintf (file
, "Aliased symbols\n\n");
474 FOR_EACH_LOCAL_DECL (cfun
, i
, var
)
476 if (may_be_aliased (var
))
477 dump_variable (file
, var
);
480 fprintf (file
, "\nCall clobber information\n");
482 fprintf (file
, "\nESCAPED");
483 dump_points_to_solution (file
, &cfun
->gimple_df
->escaped
);
485 fprintf (file
, "\n\nFlow-insensitive points-to information\n\n");
487 FOR_EACH_SSA_NAME (i
, ptr
, cfun
)
489 struct ptr_info_def
*pi
;
491 if (!POINTER_TYPE_P (TREE_TYPE (ptr
))
492 || SSA_NAME_IN_FREE_LIST (ptr
))
495 pi
= SSA_NAME_PTR_INFO (ptr
);
497 dump_points_to_info_for (file
, ptr
);
500 fprintf (file
, "\n");
504 /* Dump alias information on stderr. */
507 debug_alias_info (void)
509 dump_alias_info (stderr
);
513 /* Dump the points-to set *PT into FILE. */
516 dump_points_to_solution (FILE *file
, struct pt_solution
*pt
)
519 fprintf (file
, ", points-to anything");
522 fprintf (file
, ", points-to non-local");
525 fprintf (file
, ", points-to escaped");
528 fprintf (file
, ", points-to unit escaped");
531 fprintf (file
, ", points-to NULL");
535 fprintf (file
, ", points-to vars: ");
536 dump_decl_set (file
, pt
->vars
);
537 if (pt
->vars_contains_nonlocal
538 || pt
->vars_contains_escaped
539 || pt
->vars_contains_escaped_heap
540 || pt
->vars_contains_restrict
)
542 const char *comma
= "";
543 fprintf (file
, " (");
544 if (pt
->vars_contains_nonlocal
)
546 fprintf (file
, "nonlocal");
549 if (pt
->vars_contains_escaped
)
551 fprintf (file
, "%sescaped", comma
);
554 if (pt
->vars_contains_escaped_heap
)
556 fprintf (file
, "%sescaped heap", comma
);
559 if (pt
->vars_contains_restrict
)
561 fprintf (file
, "%srestrict", comma
);
564 if (pt
->vars_contains_interposable
)
565 fprintf (file
, "%sinterposable", comma
);
572 /* Unified dump function for pt_solution. */
575 debug (pt_solution
&ref
)
577 dump_points_to_solution (stderr
, &ref
);
581 debug (pt_solution
*ptr
)
586 fprintf (stderr
, "<nil>\n");
590 /* Dump points-to information for SSA_NAME PTR into FILE. */
593 dump_points_to_info_for (FILE *file
, tree ptr
)
595 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (ptr
);
597 print_generic_expr (file
, ptr
, dump_flags
);
600 dump_points_to_solution (file
, &pi
->pt
);
602 fprintf (file
, ", points-to anything");
604 fprintf (file
, "\n");
608 /* Dump points-to information for VAR into stderr. */
611 debug_points_to_info_for (tree var
)
613 dump_points_to_info_for (stderr
, var
);
617 /* Initializes the alias-oracle reference representation *R from REF. */
620 ao_ref_init (ao_ref
*r
, tree ref
)
627 r
->ref_alias_set
= -1;
628 r
->base_alias_set
= -1;
629 r
->volatile_p
= ref
? TREE_THIS_VOLATILE (ref
) : false;
632 /* Returns the base object of the memory reference *REF. */
635 ao_ref_base (ao_ref
*ref
)
641 ref
->base
= get_ref_base_and_extent (ref
->ref
, &ref
->offset
, &ref
->size
,
642 &ref
->max_size
, &reverse
);
646 /* Returns the base object alias set of the memory reference *REF. */
649 ao_ref_base_alias_set (ao_ref
*ref
)
652 if (ref
->base_alias_set
!= -1)
653 return ref
->base_alias_set
;
657 while (handled_component_p (base_ref
))
658 base_ref
= TREE_OPERAND (base_ref
, 0);
659 ref
->base_alias_set
= get_alias_set (base_ref
);
660 return ref
->base_alias_set
;
663 /* Returns the reference alias set of the memory reference *REF. */
666 ao_ref_alias_set (ao_ref
*ref
)
668 if (ref
->ref_alias_set
!= -1)
669 return ref
->ref_alias_set
;
670 ref
->ref_alias_set
= get_alias_set (ref
->ref
);
671 return ref
->ref_alias_set
;
674 /* Init an alias-oracle reference representation from a gimple pointer
675 PTR and a gimple size SIZE in bytes. If SIZE is NULL_TREE then the
676 size is assumed to be unknown. The access is assumed to be only
677 to or after of the pointer target, not before it. */
680 ao_ref_init_from_ptr_and_size (ao_ref
*ref
, tree ptr
, tree size
)
682 poly_int64 t
, size_hwi
, extra_offset
= 0;
683 ref
->ref
= NULL_TREE
;
684 if (TREE_CODE (ptr
) == SSA_NAME
)
686 gimple
*stmt
= SSA_NAME_DEF_STMT (ptr
);
687 if (gimple_assign_single_p (stmt
)
688 && gimple_assign_rhs_code (stmt
) == ADDR_EXPR
)
689 ptr
= gimple_assign_rhs1 (stmt
);
690 else if (is_gimple_assign (stmt
)
691 && gimple_assign_rhs_code (stmt
) == POINTER_PLUS_EXPR
692 && ptrdiff_tree_p (gimple_assign_rhs2 (stmt
), &extra_offset
))
694 ptr
= gimple_assign_rhs1 (stmt
);
695 extra_offset
*= BITS_PER_UNIT
;
699 if (TREE_CODE (ptr
) == ADDR_EXPR
)
701 ref
->base
= get_addr_base_and_unit_offset (TREE_OPERAND (ptr
, 0), &t
);
703 ref
->offset
= BITS_PER_UNIT
* t
;
708 ref
->base
= get_base_address (TREE_OPERAND (ptr
, 0));
713 gcc_assert (POINTER_TYPE_P (TREE_TYPE (ptr
)));
714 ref
->base
= build2 (MEM_REF
, char_type_node
,
715 ptr
, null_pointer_node
);
718 ref
->offset
+= extra_offset
;
720 && poly_int_tree_p (size
, &size_hwi
)
721 && coeffs_in_range_p (size_hwi
, 0, HOST_WIDE_INT_MAX
/ BITS_PER_UNIT
))
722 ref
->max_size
= ref
->size
= size_hwi
* BITS_PER_UNIT
;
724 ref
->max_size
= ref
->size
= -1;
725 ref
->ref_alias_set
= 0;
726 ref
->base_alias_set
= 0;
727 ref
->volatile_p
= false;
730 /* Return 1 if TYPE1 and TYPE2 are to be considered equivalent for the
731 purpose of TBAA. Return 0 if they are distinct and -1 if we cannot
735 same_type_for_tbaa (tree type1
, tree type2
)
737 type1
= TYPE_MAIN_VARIANT (type1
);
738 type2
= TYPE_MAIN_VARIANT (type2
);
740 /* If we would have to do structural comparison bail out. */
741 if (TYPE_STRUCTURAL_EQUALITY_P (type1
)
742 || TYPE_STRUCTURAL_EQUALITY_P (type2
))
745 /* Compare the canonical types. */
746 if (TYPE_CANONICAL (type1
) == TYPE_CANONICAL (type2
))
749 /* ??? Array types are not properly unified in all cases as we have
750 spurious changes in the index types for example. Removing this
751 causes all sorts of problems with the Fortran frontend. */
752 if (TREE_CODE (type1
) == ARRAY_TYPE
753 && TREE_CODE (type2
) == ARRAY_TYPE
)
756 /* ??? In Ada, an lvalue of an unconstrained type can be used to access an
757 object of one of its constrained subtypes, e.g. when a function with an
758 unconstrained parameter passed by reference is called on an object and
759 inlined. But, even in the case of a fixed size, type and subtypes are
760 not equivalent enough as to share the same TYPE_CANONICAL, since this
761 would mean that conversions between them are useless, whereas they are
762 not (e.g. type and subtypes can have different modes). So, in the end,
763 they are only guaranteed to have the same alias set. */
764 if (get_alias_set (type1
) == get_alias_set (type2
))
767 /* The types are known to be not equal. */
771 /* Determine if the two component references REF1 and REF2 which are
772 based on access types TYPE1 and TYPE2 and of which at least one is based
773 on an indirect reference may alias. REF2 is the only one that can
774 be a decl in which case REF2_IS_DECL is true.
775 REF1_ALIAS_SET, BASE1_ALIAS_SET, REF2_ALIAS_SET and BASE2_ALIAS_SET
776 are the respective alias sets. */
779 aliasing_component_refs_p (tree ref1
,
780 alias_set_type ref1_alias_set
,
781 alias_set_type base1_alias_set
,
782 poly_int64 offset1
, poly_int64 max_size1
,
784 alias_set_type ref2_alias_set
,
785 alias_set_type base2_alias_set
,
786 poly_int64 offset2
, poly_int64 max_size2
,
789 /* If one reference is a component references through pointers try to find a
790 common base and apply offset based disambiguation. This handles
792 struct A { int i; int j; } *q;
793 struct B { struct A a; int k; } *p;
794 disambiguating q->i and p->a.j. */
800 /* Choose bases and base types to search for. */
802 while (handled_component_p (base1
))
803 base1
= TREE_OPERAND (base1
, 0);
804 type1
= TREE_TYPE (base1
);
806 while (handled_component_p (base2
))
807 base2
= TREE_OPERAND (base2
, 0);
808 type2
= TREE_TYPE (base2
);
810 /* Now search for the type1 in the access path of ref2. This
811 would be a common base for doing offset based disambiguation on. */
813 while (handled_component_p (*refp
)
814 && same_type_for_tbaa (TREE_TYPE (*refp
), type1
) == 0)
815 refp
= &TREE_OPERAND (*refp
, 0);
816 same_p
= same_type_for_tbaa (TREE_TYPE (*refp
), type1
);
817 /* If we couldn't compare types we have to bail out. */
820 else if (same_p
== 1)
822 poly_int64 offadj
, sztmp
, msztmp
;
824 get_ref_base_and_extent (*refp
, &offadj
, &sztmp
, &msztmp
, &reverse
);
826 get_ref_base_and_extent (base1
, &offadj
, &sztmp
, &msztmp
, &reverse
);
828 return ranges_maybe_overlap_p (offset1
, max_size1
, offset2
, max_size2
);
830 /* If we didn't find a common base, try the other way around. */
832 while (handled_component_p (*refp
)
833 && same_type_for_tbaa (TREE_TYPE (*refp
), type2
) == 0)
834 refp
= &TREE_OPERAND (*refp
, 0);
835 same_p
= same_type_for_tbaa (TREE_TYPE (*refp
), type2
);
836 /* If we couldn't compare types we have to bail out. */
839 else if (same_p
== 1)
841 poly_int64 offadj
, sztmp
, msztmp
;
843 get_ref_base_and_extent (*refp
, &offadj
, &sztmp
, &msztmp
, &reverse
);
845 get_ref_base_and_extent (base2
, &offadj
, &sztmp
, &msztmp
, &reverse
);
847 return ranges_maybe_overlap_p (offset1
, max_size1
, offset2
, max_size2
);
850 /* If we have two type access paths B1.path1 and B2.path2 they may
851 only alias if either B1 is in B2.path2 or B2 is in B1.path1.
852 But we can still have a path that goes B1.path1...B2.path2 with
853 a part that we do not see. So we can only disambiguate now
854 if there is no B2 in the tail of path1 and no B1 on the
856 if (base1_alias_set
== ref2_alias_set
857 || alias_set_subset_of (base1_alias_set
, ref2_alias_set
))
859 /* If this is ptr vs. decl then we know there is no ptr ... decl path. */
861 return (base2_alias_set
== ref1_alias_set
862 || alias_set_subset_of (base2_alias_set
, ref1_alias_set
));
866 /* Return true if we can determine that component references REF1 and REF2,
867 that are within a common DECL, cannot overlap. */
870 nonoverlapping_component_refs_of_decl_p (tree ref1
, tree ref2
)
872 auto_vec
<tree
, 16> component_refs1
;
873 auto_vec
<tree
, 16> component_refs2
;
875 /* Create the stack of handled components for REF1. */
876 while (handled_component_p (ref1
))
878 component_refs1
.safe_push (ref1
);
879 ref1
= TREE_OPERAND (ref1
, 0);
881 if (TREE_CODE (ref1
) == MEM_REF
)
883 if (!integer_zerop (TREE_OPERAND (ref1
, 1)))
885 ref1
= TREE_OPERAND (TREE_OPERAND (ref1
, 0), 0);
888 /* Create the stack of handled components for REF2. */
889 while (handled_component_p (ref2
))
891 component_refs2
.safe_push (ref2
);
892 ref2
= TREE_OPERAND (ref2
, 0);
894 if (TREE_CODE (ref2
) == MEM_REF
)
896 if (!integer_zerop (TREE_OPERAND (ref2
, 1)))
898 ref2
= TREE_OPERAND (TREE_OPERAND (ref2
, 0), 0);
901 /* Bases must be either same or uncomparable. */
902 gcc_checking_assert (ref1
== ref2
903 || (DECL_P (ref1
) && DECL_P (ref2
)
904 && compare_base_decls (ref1
, ref2
) != 0));
906 /* Pop the stacks in parallel and examine the COMPONENT_REFs of the same
907 rank. This is sufficient because we start from the same DECL and you
908 cannot reference several fields at a time with COMPONENT_REFs (unlike
909 with ARRAY_RANGE_REFs for arrays) so you always need the same number
910 of them to access a sub-component, unless you're in a union, in which
911 case the return value will precisely be false. */
916 if (component_refs1
.is_empty ())
918 ref1
= component_refs1
.pop ();
920 while (!RECORD_OR_UNION_TYPE_P (TREE_TYPE (TREE_OPERAND (ref1
, 0))));
924 if (component_refs2
.is_empty ())
926 ref2
= component_refs2
.pop ();
928 while (!RECORD_OR_UNION_TYPE_P (TREE_TYPE (TREE_OPERAND (ref2
, 0))));
930 /* Beware of BIT_FIELD_REF. */
931 if (TREE_CODE (ref1
) != COMPONENT_REF
932 || TREE_CODE (ref2
) != COMPONENT_REF
)
935 tree field1
= TREE_OPERAND (ref1
, 1);
936 tree field2
= TREE_OPERAND (ref2
, 1);
938 /* ??? We cannot simply use the type of operand #0 of the refs here
939 as the Fortran compiler smuggles type punning into COMPONENT_REFs
940 for common blocks instead of using unions like everyone else. */
941 tree type1
= DECL_CONTEXT (field1
);
942 tree type2
= DECL_CONTEXT (field2
);
944 /* We cannot disambiguate fields in a union or qualified union. */
945 if (type1
!= type2
|| TREE_CODE (type1
) != RECORD_TYPE
)
948 if (field1
!= field2
)
950 /* A field and its representative need to be considered the
952 if (DECL_BIT_FIELD_REPRESENTATIVE (field1
) == field2
953 || DECL_BIT_FIELD_REPRESENTATIVE (field2
) == field1
)
955 /* Different fields of the same record type cannot overlap.
956 ??? Bitfields can overlap at RTL level so punt on them. */
957 if (DECL_BIT_FIELD (field1
) && DECL_BIT_FIELD (field2
))
966 /* qsort compare function to sort FIELD_DECLs after their
967 DECL_FIELD_CONTEXT TYPE_UID. */
970 ncr_compar (const void *field1_
, const void *field2_
)
972 const_tree field1
= *(const_tree
*) const_cast <void *>(field1_
);
973 const_tree field2
= *(const_tree
*) const_cast <void *>(field2_
);
974 unsigned int uid1
= TYPE_UID (DECL_FIELD_CONTEXT (field1
));
975 unsigned int uid2
= TYPE_UID (DECL_FIELD_CONTEXT (field2
));
978 else if (uid1
> uid2
)
983 /* Return true if we can determine that the fields referenced cannot
984 overlap for any pair of objects. */
987 nonoverlapping_component_refs_p (const_tree x
, const_tree y
)
989 if (!flag_strict_aliasing
991 || TREE_CODE (x
) != COMPONENT_REF
992 || TREE_CODE (y
) != COMPONENT_REF
)
995 auto_vec
<const_tree
, 16> fieldsx
;
996 while (TREE_CODE (x
) == COMPONENT_REF
)
998 tree field
= TREE_OPERAND (x
, 1);
999 tree type
= DECL_FIELD_CONTEXT (field
);
1000 if (TREE_CODE (type
) == RECORD_TYPE
)
1001 fieldsx
.safe_push (field
);
1002 x
= TREE_OPERAND (x
, 0);
1004 if (fieldsx
.length () == 0)
1006 auto_vec
<const_tree
, 16> fieldsy
;
1007 while (TREE_CODE (y
) == COMPONENT_REF
)
1009 tree field
= TREE_OPERAND (y
, 1);
1010 tree type
= DECL_FIELD_CONTEXT (field
);
1011 if (TREE_CODE (type
) == RECORD_TYPE
)
1012 fieldsy
.safe_push (TREE_OPERAND (y
, 1));
1013 y
= TREE_OPERAND (y
, 0);
1015 if (fieldsy
.length () == 0)
1018 /* Most common case first. */
1019 if (fieldsx
.length () == 1
1020 && fieldsy
.length () == 1)
1021 return ((DECL_FIELD_CONTEXT (fieldsx
[0])
1022 == DECL_FIELD_CONTEXT (fieldsy
[0]))
1023 && fieldsx
[0] != fieldsy
[0]
1024 && !(DECL_BIT_FIELD (fieldsx
[0]) && DECL_BIT_FIELD (fieldsy
[0])));
1026 if (fieldsx
.length () == 2)
1028 if (ncr_compar (&fieldsx
[0], &fieldsx
[1]) == 1)
1029 std::swap (fieldsx
[0], fieldsx
[1]);
1032 fieldsx
.qsort (ncr_compar
);
1034 if (fieldsy
.length () == 2)
1036 if (ncr_compar (&fieldsy
[0], &fieldsy
[1]) == 1)
1037 std::swap (fieldsy
[0], fieldsy
[1]);
1040 fieldsy
.qsort (ncr_compar
);
1042 unsigned i
= 0, j
= 0;
1045 const_tree fieldx
= fieldsx
[i
];
1046 const_tree fieldy
= fieldsy
[j
];
1047 tree typex
= DECL_FIELD_CONTEXT (fieldx
);
1048 tree typey
= DECL_FIELD_CONTEXT (fieldy
);
1051 /* We're left with accessing different fields of a structure,
1052 no possible overlap. */
1053 if (fieldx
!= fieldy
)
1055 /* A field and its representative need to be considered the
1057 if (DECL_BIT_FIELD_REPRESENTATIVE (fieldx
) == fieldy
1058 || DECL_BIT_FIELD_REPRESENTATIVE (fieldy
) == fieldx
)
1060 /* Different fields of the same record type cannot overlap.
1061 ??? Bitfields can overlap at RTL level so punt on them. */
1062 if (DECL_BIT_FIELD (fieldx
) && DECL_BIT_FIELD (fieldy
))
1067 if (TYPE_UID (typex
) < TYPE_UID (typey
))
1070 if (i
== fieldsx
.length ())
1076 if (j
== fieldsy
.length ())
1086 /* Return true if two memory references based on the variables BASE1
1087 and BASE2 constrained to [OFFSET1, OFFSET1 + MAX_SIZE1) and
1088 [OFFSET2, OFFSET2 + MAX_SIZE2) may alias. REF1 and REF2
1089 if non-NULL are the complete memory reference trees. */
1092 decl_refs_may_alias_p (tree ref1
, tree base1
,
1093 poly_int64 offset1
, poly_int64 max_size1
,
1094 tree ref2
, tree base2
,
1095 poly_int64 offset2
, poly_int64 max_size2
)
1097 gcc_checking_assert (DECL_P (base1
) && DECL_P (base2
));
1099 /* If both references are based on different variables, they cannot alias. */
1100 if (compare_base_decls (base1
, base2
) == 0)
1103 /* If both references are based on the same variable, they cannot alias if
1104 the accesses do not overlap. */
1105 if (!ranges_maybe_overlap_p (offset1
, max_size1
, offset2
, max_size2
))
1108 /* For components with variable position, the above test isn't sufficient,
1109 so we disambiguate component references manually. */
1111 && handled_component_p (ref1
) && handled_component_p (ref2
)
1112 && nonoverlapping_component_refs_of_decl_p (ref1
, ref2
))
1118 /* Return true if an indirect reference based on *PTR1 constrained
1119 to [OFFSET1, OFFSET1 + MAX_SIZE1) may alias a variable based on BASE2
1120 constrained to [OFFSET2, OFFSET2 + MAX_SIZE2). *PTR1 and BASE2 have
1121 the alias sets BASE1_ALIAS_SET and BASE2_ALIAS_SET which can be -1
1122 in which case they are computed on-demand. REF1 and REF2
1123 if non-NULL are the complete memory reference trees. */
1126 indirect_ref_may_alias_decl_p (tree ref1 ATTRIBUTE_UNUSED
, tree base1
,
1127 poly_int64 offset1
, poly_int64 max_size1
,
1128 alias_set_type ref1_alias_set
,
1129 alias_set_type base1_alias_set
,
1130 tree ref2 ATTRIBUTE_UNUSED
, tree base2
,
1131 poly_int64 offset2
, poly_int64 max_size2
,
1132 alias_set_type ref2_alias_set
,
1133 alias_set_type base2_alias_set
, bool tbaa_p
)
1136 tree ptrtype1
, dbase2
;
1138 gcc_checking_assert ((TREE_CODE (base1
) == MEM_REF
1139 || TREE_CODE (base1
) == TARGET_MEM_REF
)
1142 ptr1
= TREE_OPERAND (base1
, 0);
1143 poly_offset_int moff
= mem_ref_offset (base1
) << LOG2_BITS_PER_UNIT
;
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_maybe_overlap_p (offset1
+ moff
, -1, offset2
, 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 && poly_int_tree_p (DECL_SIZE (base2
))
1188 && poly_int_tree_p (TYPE_SIZE (TREE_TYPE (ptrtype1
)))
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 && known_lt (wi::to_poly_widest (DECL_SIZE (base2
)),
1195 wi::to_poly_widest (TYPE_SIZE (TREE_TYPE (ptrtype1
)))))
1201 /* If the decl is accessed via a MEM_REF, reconstruct the base
1202 we can use for TBAA and an appropriately adjusted offset. */
1204 while (handled_component_p (dbase2
))
1205 dbase2
= TREE_OPERAND (dbase2
, 0);
1206 poly_int64 doffset1
= offset1
;
1207 poly_offset_int doffset2
= offset2
;
1208 if (TREE_CODE (dbase2
) == MEM_REF
1209 || TREE_CODE (dbase2
) == TARGET_MEM_REF
)
1210 doffset2
-= mem_ref_offset (dbase2
) << LOG2_BITS_PER_UNIT
;
1212 /* If either reference is view-converted, give up now. */
1213 if (same_type_for_tbaa (TREE_TYPE (base1
), TREE_TYPE (ptrtype1
)) != 1
1214 || same_type_for_tbaa (TREE_TYPE (dbase2
), TREE_TYPE (base2
)) != 1)
1217 /* If both references are through the same type, they do not alias
1218 if the accesses do not overlap. This does extra disambiguation
1219 for mixed/pointer accesses but requires strict aliasing.
1220 For MEM_REFs we require that the component-ref offset we computed
1221 is relative to the start of the type which we ensure by
1222 comparing rvalue and access type and disregarding the constant
1224 if ((TREE_CODE (base1
) != TARGET_MEM_REF
1225 || (!TMR_INDEX (base1
) && !TMR_INDEX2 (base1
)))
1226 && same_type_for_tbaa (TREE_TYPE (base1
), TREE_TYPE (dbase2
)) == 1)
1227 return ranges_maybe_overlap_p (doffset1
, max_size1
, doffset2
, max_size2
);
1230 && nonoverlapping_component_refs_p (ref1
, ref2
))
1233 /* Do access-path based disambiguation. */
1235 && (handled_component_p (ref1
) || handled_component_p (ref2
)))
1236 return aliasing_component_refs_p (ref1
,
1237 ref1_alias_set
, base1_alias_set
,
1240 ref2_alias_set
, base2_alias_set
,
1241 offset2
, max_size2
, true);
1246 /* Return true if two indirect references based on *PTR1
1247 and *PTR2 constrained to [OFFSET1, OFFSET1 + MAX_SIZE1) and
1248 [OFFSET2, OFFSET2 + MAX_SIZE2) may alias. *PTR1 and *PTR2 have
1249 the alias sets BASE1_ALIAS_SET and BASE2_ALIAS_SET which can be -1
1250 in which case they are computed on-demand. REF1 and REF2
1251 if non-NULL are the complete memory reference trees. */
1254 indirect_refs_may_alias_p (tree ref1 ATTRIBUTE_UNUSED
, tree base1
,
1255 poly_int64 offset1
, poly_int64 max_size1
,
1256 alias_set_type ref1_alias_set
,
1257 alias_set_type base1_alias_set
,
1258 tree ref2 ATTRIBUTE_UNUSED
, tree base2
,
1259 poly_int64 offset2
, poly_int64 max_size2
,
1260 alias_set_type ref2_alias_set
,
1261 alias_set_type base2_alias_set
, bool tbaa_p
)
1265 tree ptrtype1
, ptrtype2
;
1267 gcc_checking_assert ((TREE_CODE (base1
) == MEM_REF
1268 || TREE_CODE (base1
) == TARGET_MEM_REF
)
1269 && (TREE_CODE (base2
) == MEM_REF
1270 || TREE_CODE (base2
) == TARGET_MEM_REF
));
1272 ptr1
= TREE_OPERAND (base1
, 0);
1273 ptr2
= TREE_OPERAND (base2
, 0);
1275 /* If both bases are based on pointers they cannot alias if they may not
1276 point to the same memory object or if they point to the same object
1277 and the accesses do not overlap. */
1278 if ((!cfun
|| gimple_in_ssa_p (cfun
))
1279 && operand_equal_p (ptr1
, ptr2
, 0)
1280 && (((TREE_CODE (base1
) != TARGET_MEM_REF
1281 || (!TMR_INDEX (base1
) && !TMR_INDEX2 (base1
)))
1282 && (TREE_CODE (base2
) != TARGET_MEM_REF
1283 || (!TMR_INDEX (base2
) && !TMR_INDEX2 (base2
))))
1284 || (TREE_CODE (base1
) == TARGET_MEM_REF
1285 && TREE_CODE (base2
) == TARGET_MEM_REF
1286 && (TMR_STEP (base1
) == TMR_STEP (base2
)
1287 || (TMR_STEP (base1
) && TMR_STEP (base2
)
1288 && operand_equal_p (TMR_STEP (base1
),
1289 TMR_STEP (base2
), 0)))
1290 && (TMR_INDEX (base1
) == TMR_INDEX (base2
)
1291 || (TMR_INDEX (base1
) && TMR_INDEX (base2
)
1292 && operand_equal_p (TMR_INDEX (base1
),
1293 TMR_INDEX (base2
), 0)))
1294 && (TMR_INDEX2 (base1
) == TMR_INDEX2 (base2
)
1295 || (TMR_INDEX2 (base1
) && TMR_INDEX2 (base2
)
1296 && operand_equal_p (TMR_INDEX2 (base1
),
1297 TMR_INDEX2 (base2
), 0))))))
1299 poly_offset_int moff1
= mem_ref_offset (base1
) << LOG2_BITS_PER_UNIT
;
1300 poly_offset_int moff2
= mem_ref_offset (base2
) << LOG2_BITS_PER_UNIT
;
1301 return ranges_maybe_overlap_p (offset1
+ moff1
, max_size1
,
1302 offset2
+ moff2
, max_size2
);
1304 if (!ptr_derefs_may_alias_p (ptr1
, ptr2
))
1307 /* Disambiguations that rely on strict aliasing rules follow. */
1308 if (!flag_strict_aliasing
|| !tbaa_p
)
1311 ptrtype1
= TREE_TYPE (TREE_OPERAND (base1
, 1));
1312 ptrtype2
= TREE_TYPE (TREE_OPERAND (base2
, 1));
1314 /* If the alias set for a pointer access is zero all bets are off. */
1315 if (base1_alias_set
== 0
1316 || base2_alias_set
== 0)
1319 /* If both references are through the same type, they do not alias
1320 if the accesses do not overlap. This does extra disambiguation
1321 for mixed/pointer accesses but requires strict aliasing. */
1322 if ((TREE_CODE (base1
) != TARGET_MEM_REF
1323 || (!TMR_INDEX (base1
) && !TMR_INDEX2 (base1
)))
1324 && (TREE_CODE (base2
) != TARGET_MEM_REF
1325 || (!TMR_INDEX (base2
) && !TMR_INDEX2 (base2
)))
1326 && same_type_for_tbaa (TREE_TYPE (base1
), TREE_TYPE (ptrtype1
)) == 1
1327 && same_type_for_tbaa (TREE_TYPE (base2
), TREE_TYPE (ptrtype2
)) == 1
1328 && same_type_for_tbaa (TREE_TYPE (ptrtype1
),
1329 TREE_TYPE (ptrtype2
)) == 1
1330 /* But avoid treating arrays as "objects", instead assume they
1331 can overlap by an exact multiple of their element size. */
1332 && TREE_CODE (TREE_TYPE (ptrtype1
)) != ARRAY_TYPE
)
1333 return ranges_maybe_overlap_p (offset1
, max_size1
, offset2
, max_size2
);
1335 /* Do type-based disambiguation. */
1336 if (base1_alias_set
!= base2_alias_set
1337 && !alias_sets_conflict_p (base1_alias_set
, base2_alias_set
))
1340 /* If either reference is view-converted, give up now. */
1341 if (same_type_for_tbaa (TREE_TYPE (base1
), TREE_TYPE (ptrtype1
)) != 1
1342 || same_type_for_tbaa (TREE_TYPE (base2
), TREE_TYPE (ptrtype2
)) != 1)
1346 && nonoverlapping_component_refs_p (ref1
, ref2
))
1349 /* Do access-path based disambiguation. */
1351 && (handled_component_p (ref1
) || handled_component_p (ref2
)))
1352 return aliasing_component_refs_p (ref1
,
1353 ref1_alias_set
, base1_alias_set
,
1356 ref2_alias_set
, base2_alias_set
,
1357 offset2
, max_size2
, false);
1362 /* Return true, if the two memory references REF1 and REF2 may alias. */
1365 refs_may_alias_p_1 (ao_ref
*ref1
, ao_ref
*ref2
, bool tbaa_p
)
1368 poly_int64 offset1
= 0, offset2
= 0;
1369 poly_int64 max_size1
= -1, max_size2
= -1;
1370 bool var1_p
, var2_p
, ind1_p
, ind2_p
;
1372 gcc_checking_assert ((!ref1
->ref
1373 || TREE_CODE (ref1
->ref
) == SSA_NAME
1374 || DECL_P (ref1
->ref
)
1375 || TREE_CODE (ref1
->ref
) == STRING_CST
1376 || handled_component_p (ref1
->ref
)
1377 || TREE_CODE (ref1
->ref
) == MEM_REF
1378 || TREE_CODE (ref1
->ref
) == TARGET_MEM_REF
)
1380 || TREE_CODE (ref2
->ref
) == SSA_NAME
1381 || DECL_P (ref2
->ref
)
1382 || TREE_CODE (ref2
->ref
) == STRING_CST
1383 || handled_component_p (ref2
->ref
)
1384 || TREE_CODE (ref2
->ref
) == MEM_REF
1385 || TREE_CODE (ref2
->ref
) == TARGET_MEM_REF
));
1387 /* Decompose the references into their base objects and the access. */
1388 base1
= ao_ref_base (ref1
);
1389 offset1
= ref1
->offset
;
1390 max_size1
= ref1
->max_size
;
1391 base2
= ao_ref_base (ref2
);
1392 offset2
= ref2
->offset
;
1393 max_size2
= ref2
->max_size
;
1395 /* We can end up with registers or constants as bases for example from
1396 *D.1663_44 = VIEW_CONVERT_EXPR<struct DB_LSN>(__tmp$B0F64_59);
1397 which is seen as a struct copy. */
1398 if (TREE_CODE (base1
) == SSA_NAME
1399 || TREE_CODE (base1
) == CONST_DECL
1400 || TREE_CODE (base1
) == CONSTRUCTOR
1401 || TREE_CODE (base1
) == ADDR_EXPR
1402 || CONSTANT_CLASS_P (base1
)
1403 || TREE_CODE (base2
) == SSA_NAME
1404 || TREE_CODE (base2
) == CONST_DECL
1405 || TREE_CODE (base2
) == CONSTRUCTOR
1406 || TREE_CODE (base2
) == ADDR_EXPR
1407 || CONSTANT_CLASS_P (base2
))
1410 /* We can end up referring to code via function and label decls.
1411 As we likely do not properly track code aliases conservatively
1413 if (TREE_CODE (base1
) == FUNCTION_DECL
1414 || TREE_CODE (base1
) == LABEL_DECL
1415 || TREE_CODE (base2
) == FUNCTION_DECL
1416 || TREE_CODE (base2
) == LABEL_DECL
)
1419 /* Two volatile accesses always conflict. */
1420 if (ref1
->volatile_p
1421 && ref2
->volatile_p
)
1424 /* Defer to simple offset based disambiguation if we have
1425 references based on two decls. Do this before defering to
1426 TBAA to handle must-alias cases in conformance with the
1427 GCC extension of allowing type-punning through unions. */
1428 var1_p
= DECL_P (base1
);
1429 var2_p
= DECL_P (base2
);
1430 if (var1_p
&& var2_p
)
1431 return decl_refs_may_alias_p (ref1
->ref
, base1
, offset1
, max_size1
,
1432 ref2
->ref
, base2
, offset2
, max_size2
);
1434 /* Handle restrict based accesses.
1435 ??? ao_ref_base strips inner MEM_REF [&decl], recover from that
1437 tree rbase1
= base1
;
1438 tree rbase2
= base2
;
1443 while (handled_component_p (rbase1
))
1444 rbase1
= TREE_OPERAND (rbase1
, 0);
1450 while (handled_component_p (rbase2
))
1451 rbase2
= TREE_OPERAND (rbase2
, 0);
1453 if (rbase1
&& rbase2
1454 && (TREE_CODE (base1
) == MEM_REF
|| TREE_CODE (base1
) == TARGET_MEM_REF
)
1455 && (TREE_CODE (base2
) == MEM_REF
|| TREE_CODE (base2
) == TARGET_MEM_REF
)
1456 /* If the accesses are in the same restrict clique... */
1457 && MR_DEPENDENCE_CLIQUE (base1
) == MR_DEPENDENCE_CLIQUE (base2
)
1458 /* But based on different pointers they do not alias. */
1459 && MR_DEPENDENCE_BASE (base1
) != MR_DEPENDENCE_BASE (base2
))
1462 ind1_p
= (TREE_CODE (base1
) == MEM_REF
1463 || TREE_CODE (base1
) == TARGET_MEM_REF
);
1464 ind2_p
= (TREE_CODE (base2
) == MEM_REF
1465 || TREE_CODE (base2
) == TARGET_MEM_REF
);
1467 /* Canonicalize the pointer-vs-decl case. */
1468 if (ind1_p
&& var2_p
)
1470 std::swap (offset1
, offset2
);
1471 std::swap (max_size1
, max_size2
);
1472 std::swap (base1
, base2
);
1473 std::swap (ref1
, ref2
);
1480 /* First defer to TBAA if possible. */
1482 && flag_strict_aliasing
1483 && !alias_sets_conflict_p (ao_ref_alias_set (ref1
),
1484 ao_ref_alias_set (ref2
)))
1487 /* If the reference is based on a pointer that points to memory
1488 that may not be written to then the other reference cannot possibly
1490 if ((TREE_CODE (TREE_OPERAND (base2
, 0)) == SSA_NAME
1491 && SSA_NAME_POINTS_TO_READONLY_MEMORY (TREE_OPERAND (base2
, 0)))
1493 && TREE_CODE (TREE_OPERAND (base1
, 0)) == SSA_NAME
1494 && SSA_NAME_POINTS_TO_READONLY_MEMORY (TREE_OPERAND (base1
, 0))))
1497 /* Dispatch to the pointer-vs-decl or pointer-vs-pointer disambiguators. */
1498 if (var1_p
&& ind2_p
)
1499 return indirect_ref_may_alias_decl_p (ref2
->ref
, base2
,
1501 ao_ref_alias_set (ref2
),
1502 ao_ref_base_alias_set (ref2
),
1505 ao_ref_alias_set (ref1
),
1506 ao_ref_base_alias_set (ref1
),
1508 else if (ind1_p
&& ind2_p
)
1509 return indirect_refs_may_alias_p (ref1
->ref
, base1
,
1511 ao_ref_alias_set (ref1
),
1512 ao_ref_base_alias_set (ref1
),
1515 ao_ref_alias_set (ref2
),
1516 ao_ref_base_alias_set (ref2
),
1523 refs_may_alias_p (tree ref1
, ao_ref
*ref2
, bool tbaa_p
)
1526 ao_ref_init (&r1
, ref1
);
1527 return refs_may_alias_p_1 (&r1
, ref2
, tbaa_p
);
1531 refs_may_alias_p (tree ref1
, tree ref2
, bool tbaa_p
)
1535 ao_ref_init (&r1
, ref1
);
1536 ao_ref_init (&r2
, ref2
);
1537 res
= refs_may_alias_p_1 (&r1
, &r2
, tbaa_p
);
1539 ++alias_stats
.refs_may_alias_p_may_alias
;
1541 ++alias_stats
.refs_may_alias_p_no_alias
;
1545 /* Returns true if there is a anti-dependence for the STORE that
1546 executes after the LOAD. */
1549 refs_anti_dependent_p (tree load
, tree store
)
1552 ao_ref_init (&r1
, load
);
1553 ao_ref_init (&r2
, store
);
1554 return refs_may_alias_p_1 (&r1
, &r2
, false);
1557 /* Returns true if there is a output dependence for the stores
1558 STORE1 and STORE2. */
1561 refs_output_dependent_p (tree store1
, tree store2
)
1564 ao_ref_init (&r1
, store1
);
1565 ao_ref_init (&r2
, store2
);
1566 return refs_may_alias_p_1 (&r1
, &r2
, false);
1569 /* If the call CALL may use the memory reference REF return true,
1570 otherwise return false. */
1573 ref_maybe_used_by_call_p_1 (gcall
*call
, ao_ref
*ref
, bool tbaa_p
)
1577 int flags
= gimple_call_flags (call
);
1579 /* Const functions without a static chain do not implicitly use memory. */
1580 if (!gimple_call_chain (call
)
1581 && (flags
& (ECF_CONST
|ECF_NOVOPS
)))
1584 base
= ao_ref_base (ref
);
1588 /* A call that is not without side-effects might involve volatile
1589 accesses and thus conflicts with all other volatile accesses. */
1590 if (ref
->volatile_p
)
1593 /* If the reference is based on a decl that is not aliased the call
1594 cannot possibly use it. */
1596 && !may_be_aliased (base
)
1597 /* But local statics can be used through recursion. */
1598 && !is_global_var (base
))
1601 callee
= gimple_call_fndecl (call
);
1603 /* Handle those builtin functions explicitly that do not act as
1604 escape points. See tree-ssa-structalias.c:find_func_aliases
1605 for the list of builtins we might need to handle here. */
1606 if (callee
!= NULL_TREE
1607 && gimple_call_builtin_p (call
, BUILT_IN_NORMAL
))
1608 switch (DECL_FUNCTION_CODE (callee
))
1610 /* All the following functions read memory pointed to by
1611 their second argument. strcat/strncat additionally
1612 reads memory pointed to by the first argument. */
1613 case BUILT_IN_STRCAT
:
1614 case BUILT_IN_STRNCAT
:
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
:
1625 case BUILT_IN_STRNCPY
:
1626 case BUILT_IN_MEMCPY
:
1627 case BUILT_IN_MEMMOVE
:
1628 case BUILT_IN_MEMPCPY
:
1629 case BUILT_IN_STPCPY
:
1630 case BUILT_IN_STPNCPY
:
1631 case BUILT_IN_TM_MEMCPY
:
1632 case BUILT_IN_TM_MEMMOVE
:
1635 tree size
= NULL_TREE
;
1636 if (gimple_call_num_args (call
) == 3)
1637 size
= gimple_call_arg (call
, 2);
1638 ao_ref_init_from_ptr_and_size (&dref
,
1639 gimple_call_arg (call
, 1),
1641 return refs_may_alias_p_1 (&dref
, ref
, false);
1643 case BUILT_IN_STRCAT_CHK
:
1644 case BUILT_IN_STRNCAT_CHK
:
1647 ao_ref_init_from_ptr_and_size (&dref
,
1648 gimple_call_arg (call
, 0),
1650 if (refs_may_alias_p_1 (&dref
, ref
, false))
1654 case BUILT_IN_STRCPY_CHK
:
1655 case BUILT_IN_STRNCPY_CHK
:
1656 case BUILT_IN_MEMCPY_CHK
:
1657 case BUILT_IN_MEMMOVE_CHK
:
1658 case BUILT_IN_MEMPCPY_CHK
:
1659 case BUILT_IN_STPCPY_CHK
:
1660 case BUILT_IN_STPNCPY_CHK
:
1663 tree size
= NULL_TREE
;
1664 if (gimple_call_num_args (call
) == 4)
1665 size
= gimple_call_arg (call
, 2);
1666 ao_ref_init_from_ptr_and_size (&dref
,
1667 gimple_call_arg (call
, 1),
1669 return refs_may_alias_p_1 (&dref
, ref
, false);
1671 case BUILT_IN_BCOPY
:
1674 tree size
= gimple_call_arg (call
, 2);
1675 ao_ref_init_from_ptr_and_size (&dref
,
1676 gimple_call_arg (call
, 0),
1678 return refs_may_alias_p_1 (&dref
, ref
, false);
1681 /* The following functions read memory pointed to by their
1683 CASE_BUILT_IN_TM_LOAD (1):
1684 CASE_BUILT_IN_TM_LOAD (2):
1685 CASE_BUILT_IN_TM_LOAD (4):
1686 CASE_BUILT_IN_TM_LOAD (8):
1687 CASE_BUILT_IN_TM_LOAD (FLOAT
):
1688 CASE_BUILT_IN_TM_LOAD (DOUBLE
):
1689 CASE_BUILT_IN_TM_LOAD (LDOUBLE
):
1690 CASE_BUILT_IN_TM_LOAD (M64
):
1691 CASE_BUILT_IN_TM_LOAD (M128
):
1692 CASE_BUILT_IN_TM_LOAD (M256
):
1693 case BUILT_IN_TM_LOG
:
1694 case BUILT_IN_TM_LOG_1
:
1695 case BUILT_IN_TM_LOG_2
:
1696 case BUILT_IN_TM_LOG_4
:
1697 case BUILT_IN_TM_LOG_8
:
1698 case BUILT_IN_TM_LOG_FLOAT
:
1699 case BUILT_IN_TM_LOG_DOUBLE
:
1700 case BUILT_IN_TM_LOG_LDOUBLE
:
1701 case BUILT_IN_TM_LOG_M64
:
1702 case BUILT_IN_TM_LOG_M128
:
1703 case BUILT_IN_TM_LOG_M256
:
1704 return ptr_deref_may_alias_ref_p_1 (gimple_call_arg (call
, 0), ref
);
1706 /* These read memory pointed to by the first argument. */
1707 case BUILT_IN_STRDUP
:
1708 case BUILT_IN_STRNDUP
:
1709 case BUILT_IN_REALLOC
:
1712 tree size
= NULL_TREE
;
1713 if (gimple_call_num_args (call
) == 2)
1714 size
= gimple_call_arg (call
, 1);
1715 ao_ref_init_from_ptr_and_size (&dref
,
1716 gimple_call_arg (call
, 0),
1718 return refs_may_alias_p_1 (&dref
, ref
, false);
1720 /* These read memory pointed to by the first argument. */
1721 case BUILT_IN_INDEX
:
1722 case BUILT_IN_STRCHR
:
1723 case BUILT_IN_STRRCHR
:
1726 ao_ref_init_from_ptr_and_size (&dref
,
1727 gimple_call_arg (call
, 0),
1729 return refs_may_alias_p_1 (&dref
, ref
, false);
1731 /* These read memory pointed to by the first argument with size
1732 in the third argument. */
1733 case BUILT_IN_MEMCHR
:
1736 ao_ref_init_from_ptr_and_size (&dref
,
1737 gimple_call_arg (call
, 0),
1738 gimple_call_arg (call
, 2));
1739 return refs_may_alias_p_1 (&dref
, ref
, false);
1741 /* These read memory pointed to by the first and second arguments. */
1742 case BUILT_IN_STRSTR
:
1743 case BUILT_IN_STRPBRK
:
1746 ao_ref_init_from_ptr_and_size (&dref
,
1747 gimple_call_arg (call
, 0),
1749 if (refs_may_alias_p_1 (&dref
, ref
, false))
1751 ao_ref_init_from_ptr_and_size (&dref
,
1752 gimple_call_arg (call
, 1),
1754 return refs_may_alias_p_1 (&dref
, ref
, false);
1757 /* The following builtins do not read from memory. */
1759 case BUILT_IN_MALLOC
:
1760 case BUILT_IN_POSIX_MEMALIGN
:
1761 case BUILT_IN_ALIGNED_ALLOC
:
1762 case BUILT_IN_CALLOC
:
1763 CASE_BUILT_IN_ALLOCA
:
1764 case BUILT_IN_STACK_SAVE
:
1765 case BUILT_IN_STACK_RESTORE
:
1766 case BUILT_IN_MEMSET
:
1767 case BUILT_IN_TM_MEMSET
:
1768 case BUILT_IN_MEMSET_CHK
:
1769 case BUILT_IN_FREXP
:
1770 case BUILT_IN_FREXPF
:
1771 case BUILT_IN_FREXPL
:
1772 case BUILT_IN_GAMMA_R
:
1773 case BUILT_IN_GAMMAF_R
:
1774 case BUILT_IN_GAMMAL_R
:
1775 case BUILT_IN_LGAMMA_R
:
1776 case BUILT_IN_LGAMMAF_R
:
1777 case BUILT_IN_LGAMMAL_R
:
1779 case BUILT_IN_MODFF
:
1780 case BUILT_IN_MODFL
:
1781 case BUILT_IN_REMQUO
:
1782 case BUILT_IN_REMQUOF
:
1783 case BUILT_IN_REMQUOL
:
1784 case BUILT_IN_SINCOS
:
1785 case BUILT_IN_SINCOSF
:
1786 case BUILT_IN_SINCOSL
:
1787 case BUILT_IN_ASSUME_ALIGNED
:
1788 case BUILT_IN_VA_END
:
1790 /* __sync_* builtins and some OpenMP builtins act as threading
1792 #undef DEF_SYNC_BUILTIN
1793 #define DEF_SYNC_BUILTIN(ENUM, NAME, TYPE, ATTRS) case ENUM:
1794 #include "sync-builtins.def"
1795 #undef DEF_SYNC_BUILTIN
1796 case BUILT_IN_GOMP_ATOMIC_START
:
1797 case BUILT_IN_GOMP_ATOMIC_END
:
1798 case BUILT_IN_GOMP_BARRIER
:
1799 case BUILT_IN_GOMP_BARRIER_CANCEL
:
1800 case BUILT_IN_GOMP_TASKWAIT
:
1801 case BUILT_IN_GOMP_TASKGROUP_END
:
1802 case BUILT_IN_GOMP_CRITICAL_START
:
1803 case BUILT_IN_GOMP_CRITICAL_END
:
1804 case BUILT_IN_GOMP_CRITICAL_NAME_START
:
1805 case BUILT_IN_GOMP_CRITICAL_NAME_END
:
1806 case BUILT_IN_GOMP_LOOP_END
:
1807 case BUILT_IN_GOMP_LOOP_END_CANCEL
:
1808 case BUILT_IN_GOMP_ORDERED_START
:
1809 case BUILT_IN_GOMP_ORDERED_END
:
1810 case BUILT_IN_GOMP_SECTIONS_END
:
1811 case BUILT_IN_GOMP_SECTIONS_END_CANCEL
:
1812 case BUILT_IN_GOMP_SINGLE_COPY_START
:
1813 case BUILT_IN_GOMP_SINGLE_COPY_END
:
1817 /* Fallthru to general call handling. */;
1820 /* Check if base is a global static variable that is not read
1822 if (callee
!= NULL_TREE
&& VAR_P (base
) && TREE_STATIC (base
))
1824 struct cgraph_node
*node
= cgraph_node::get (callee
);
1827 /* FIXME: Callee can be an OMP builtin that does not have a call graph
1828 node yet. We should enforce that there are nodes for all decls in the
1829 IL and remove this check instead. */
1831 && (not_read
= ipa_reference_get_not_read_global (node
))
1832 && bitmap_bit_p (not_read
, ipa_reference_var_uid (base
)))
1836 /* Check if the base variable is call-used. */
1839 if (pt_solution_includes (gimple_call_use_set (call
), base
))
1842 else if ((TREE_CODE (base
) == MEM_REF
1843 || TREE_CODE (base
) == TARGET_MEM_REF
)
1844 && TREE_CODE (TREE_OPERAND (base
, 0)) == SSA_NAME
)
1846 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (TREE_OPERAND (base
, 0));
1850 if (pt_solutions_intersect (gimple_call_use_set (call
), &pi
->pt
))
1856 /* Inspect call arguments for passed-by-value aliases. */
1858 for (i
= 0; i
< gimple_call_num_args (call
); ++i
)
1860 tree op
= gimple_call_arg (call
, i
);
1861 int flags
= gimple_call_arg_flags (call
, i
);
1863 if (flags
& EAF_UNUSED
)
1866 if (TREE_CODE (op
) == WITH_SIZE_EXPR
)
1867 op
= TREE_OPERAND (op
, 0);
1869 if (TREE_CODE (op
) != SSA_NAME
1870 && !is_gimple_min_invariant (op
))
1873 ao_ref_init (&r
, op
);
1874 if (refs_may_alias_p_1 (&r
, ref
, tbaa_p
))
1883 ref_maybe_used_by_call_p (gcall
*call
, ao_ref
*ref
, bool tbaa_p
)
1886 res
= ref_maybe_used_by_call_p_1 (call
, ref
, tbaa_p
);
1888 ++alias_stats
.ref_maybe_used_by_call_p_may_alias
;
1890 ++alias_stats
.ref_maybe_used_by_call_p_no_alias
;
1895 /* If the statement STMT may use the memory reference REF return
1896 true, otherwise return false. */
1899 ref_maybe_used_by_stmt_p (gimple
*stmt
, ao_ref
*ref
, bool tbaa_p
)
1901 if (is_gimple_assign (stmt
))
1905 /* All memory assign statements are single. */
1906 if (!gimple_assign_single_p (stmt
))
1909 rhs
= gimple_assign_rhs1 (stmt
);
1910 if (is_gimple_reg (rhs
)
1911 || is_gimple_min_invariant (rhs
)
1912 || gimple_assign_rhs_code (stmt
) == CONSTRUCTOR
)
1915 return refs_may_alias_p (rhs
, ref
, tbaa_p
);
1917 else if (is_gimple_call (stmt
))
1918 return ref_maybe_used_by_call_p (as_a
<gcall
*> (stmt
), ref
, tbaa_p
);
1919 else if (greturn
*return_stmt
= dyn_cast
<greturn
*> (stmt
))
1921 tree retval
= gimple_return_retval (return_stmt
);
1923 && TREE_CODE (retval
) != SSA_NAME
1924 && !is_gimple_min_invariant (retval
)
1925 && refs_may_alias_p (retval
, ref
, tbaa_p
))
1927 /* If ref escapes the function then the return acts as a use. */
1928 tree base
= ao_ref_base (ref
);
1931 else if (DECL_P (base
))
1932 return is_global_var (base
);
1933 else if (TREE_CODE (base
) == MEM_REF
1934 || TREE_CODE (base
) == TARGET_MEM_REF
)
1935 return ptr_deref_may_alias_global_p (TREE_OPERAND (base
, 0));
1943 ref_maybe_used_by_stmt_p (gimple
*stmt
, tree ref
, bool tbaa_p
)
1946 ao_ref_init (&r
, ref
);
1947 return ref_maybe_used_by_stmt_p (stmt
, &r
, tbaa_p
);
1950 /* If the call in statement CALL may clobber the memory reference REF
1951 return true, otherwise return false. */
1954 call_may_clobber_ref_p_1 (gcall
*call
, ao_ref
*ref
)
1959 /* If the call is pure or const it cannot clobber anything. */
1960 if (gimple_call_flags (call
)
1961 & (ECF_PURE
|ECF_CONST
|ECF_LOOPING_CONST_OR_PURE
|ECF_NOVOPS
))
1963 if (gimple_call_internal_p (call
))
1964 switch (gimple_call_internal_fn (call
))
1966 /* Treat these internal calls like ECF_PURE for aliasing,
1967 they don't write to any memory the program should care about.
1968 They have important other side-effects, and read memory,
1969 so can't be ECF_NOVOPS. */
1970 case IFN_UBSAN_NULL
:
1971 case IFN_UBSAN_BOUNDS
:
1972 case IFN_UBSAN_VPTR
:
1973 case IFN_UBSAN_OBJECT_SIZE
:
1975 case IFN_ASAN_CHECK
:
1981 base
= ao_ref_base (ref
);
1985 if (TREE_CODE (base
) == SSA_NAME
1986 || CONSTANT_CLASS_P (base
))
1989 /* A call that is not without side-effects might involve volatile
1990 accesses and thus conflicts with all other volatile accesses. */
1991 if (ref
->volatile_p
)
1994 /* If the reference is based on a decl that is not aliased the call
1995 cannot possibly clobber it. */
1997 && !may_be_aliased (base
)
1998 /* But local non-readonly statics can be modified through recursion
1999 or the call may implement a threading barrier which we must
2000 treat as may-def. */
2001 && (TREE_READONLY (base
)
2002 || !is_global_var (base
)))
2005 /* If the reference is based on a pointer that points to memory
2006 that may not be written to then the call cannot possibly clobber it. */
2007 if ((TREE_CODE (base
) == MEM_REF
2008 || TREE_CODE (base
) == TARGET_MEM_REF
)
2009 && TREE_CODE (TREE_OPERAND (base
, 0)) == SSA_NAME
2010 && SSA_NAME_POINTS_TO_READONLY_MEMORY (TREE_OPERAND (base
, 0)))
2013 callee
= gimple_call_fndecl (call
);
2015 /* Handle those builtin functions explicitly that do not act as
2016 escape points. See tree-ssa-structalias.c:find_func_aliases
2017 for the list of builtins we might need to handle here. */
2018 if (callee
!= NULL_TREE
2019 && gimple_call_builtin_p (call
, BUILT_IN_NORMAL
))
2020 switch (DECL_FUNCTION_CODE (callee
))
2022 /* All the following functions clobber memory pointed to by
2023 their first argument. */
2024 case BUILT_IN_STRCPY
:
2025 case BUILT_IN_STRNCPY
:
2026 case BUILT_IN_MEMCPY
:
2027 case BUILT_IN_MEMMOVE
:
2028 case BUILT_IN_MEMPCPY
:
2029 case BUILT_IN_STPCPY
:
2030 case BUILT_IN_STPNCPY
:
2031 case BUILT_IN_STRCAT
:
2032 case BUILT_IN_STRNCAT
:
2033 case BUILT_IN_MEMSET
:
2034 case BUILT_IN_TM_MEMSET
:
2035 CASE_BUILT_IN_TM_STORE (1):
2036 CASE_BUILT_IN_TM_STORE (2):
2037 CASE_BUILT_IN_TM_STORE (4):
2038 CASE_BUILT_IN_TM_STORE (8):
2039 CASE_BUILT_IN_TM_STORE (FLOAT
):
2040 CASE_BUILT_IN_TM_STORE (DOUBLE
):
2041 CASE_BUILT_IN_TM_STORE (LDOUBLE
):
2042 CASE_BUILT_IN_TM_STORE (M64
):
2043 CASE_BUILT_IN_TM_STORE (M128
):
2044 CASE_BUILT_IN_TM_STORE (M256
):
2045 case BUILT_IN_TM_MEMCPY
:
2046 case BUILT_IN_TM_MEMMOVE
:
2049 tree size
= NULL_TREE
;
2050 /* Don't pass in size for strncat, as the maximum size
2051 is strlen (dest) + n + 1 instead of n, resp.
2052 n + 1 at dest + strlen (dest), but strlen (dest) isn't
2054 if (gimple_call_num_args (call
) == 3
2055 && DECL_FUNCTION_CODE (callee
) != BUILT_IN_STRNCAT
)
2056 size
= gimple_call_arg (call
, 2);
2057 ao_ref_init_from_ptr_and_size (&dref
,
2058 gimple_call_arg (call
, 0),
2060 return refs_may_alias_p_1 (&dref
, ref
, false);
2062 case BUILT_IN_STRCPY_CHK
:
2063 case BUILT_IN_STRNCPY_CHK
:
2064 case BUILT_IN_MEMCPY_CHK
:
2065 case BUILT_IN_MEMMOVE_CHK
:
2066 case BUILT_IN_MEMPCPY_CHK
:
2067 case BUILT_IN_STPCPY_CHK
:
2068 case BUILT_IN_STPNCPY_CHK
:
2069 case BUILT_IN_STRCAT_CHK
:
2070 case BUILT_IN_STRNCAT_CHK
:
2071 case BUILT_IN_MEMSET_CHK
:
2074 tree size
= NULL_TREE
;
2075 /* Don't pass in size for __strncat_chk, as the maximum size
2076 is strlen (dest) + n + 1 instead of n, resp.
2077 n + 1 at dest + strlen (dest), but strlen (dest) isn't
2079 if (gimple_call_num_args (call
) == 4
2080 && DECL_FUNCTION_CODE (callee
) != BUILT_IN_STRNCAT_CHK
)
2081 size
= gimple_call_arg (call
, 2);
2082 ao_ref_init_from_ptr_and_size (&dref
,
2083 gimple_call_arg (call
, 0),
2085 return refs_may_alias_p_1 (&dref
, ref
, false);
2087 case BUILT_IN_BCOPY
:
2090 tree size
= gimple_call_arg (call
, 2);
2091 ao_ref_init_from_ptr_and_size (&dref
,
2092 gimple_call_arg (call
, 1),
2094 return refs_may_alias_p_1 (&dref
, ref
, false);
2096 /* Allocating memory does not have any side-effects apart from
2097 being the definition point for the pointer. */
2098 case BUILT_IN_MALLOC
:
2099 case BUILT_IN_ALIGNED_ALLOC
:
2100 case BUILT_IN_CALLOC
:
2101 case BUILT_IN_STRDUP
:
2102 case BUILT_IN_STRNDUP
:
2103 /* Unix98 specifies that errno is set on allocation failure. */
2105 && targetm
.ref_may_alias_errno (ref
))
2108 case BUILT_IN_STACK_SAVE
:
2109 CASE_BUILT_IN_ALLOCA
:
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
&& VAR_P (base
) && TREE_STATIC (base
))
2219 struct cgraph_node
*node
= cgraph_node::get (callee
);
2223 && (not_written
= ipa_reference_get_not_written_global (node
))
2224 && bitmap_bit_p (not_written
, ipa_reference_var_uid (base
)))
2228 /* Check if the base variable is call-clobbered. */
2230 return pt_solution_includes (gimple_call_clobber_set (call
), base
);
2231 else if ((TREE_CODE (base
) == MEM_REF
2232 || TREE_CODE (base
) == TARGET_MEM_REF
)
2233 && TREE_CODE (TREE_OPERAND (base
, 0)) == SSA_NAME
)
2235 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (TREE_OPERAND (base
, 0));
2239 return pt_solutions_intersect (gimple_call_clobber_set (call
), &pi
->pt
);
2245 /* If the call in statement CALL may clobber the memory reference REF
2246 return true, otherwise return false. */
2249 call_may_clobber_ref_p (gcall
*call
, tree ref
)
2253 ao_ref_init (&r
, ref
);
2254 res
= call_may_clobber_ref_p_1 (call
, &r
);
2256 ++alias_stats
.call_may_clobber_ref_p_may_alias
;
2258 ++alias_stats
.call_may_clobber_ref_p_no_alias
;
2263 /* If the statement STMT may clobber the memory reference REF return true,
2264 otherwise return false. */
2267 stmt_may_clobber_ref_p_1 (gimple
*stmt
, ao_ref
*ref
, bool tbaa_p
)
2269 if (is_gimple_call (stmt
))
2271 tree lhs
= gimple_call_lhs (stmt
);
2273 && TREE_CODE (lhs
) != SSA_NAME
)
2276 ao_ref_init (&r
, lhs
);
2277 if (refs_may_alias_p_1 (ref
, &r
, tbaa_p
))
2281 return call_may_clobber_ref_p_1 (as_a
<gcall
*> (stmt
), ref
);
2283 else if (gimple_assign_single_p (stmt
))
2285 tree lhs
= gimple_assign_lhs (stmt
);
2286 if (TREE_CODE (lhs
) != SSA_NAME
)
2289 ao_ref_init (&r
, lhs
);
2290 return refs_may_alias_p_1 (ref
, &r
, tbaa_p
);
2293 else if (gimple_code (stmt
) == GIMPLE_ASM
)
2300 stmt_may_clobber_ref_p (gimple
*stmt
, tree ref
, bool tbaa_p
)
2303 ao_ref_init (&r
, ref
);
2304 return stmt_may_clobber_ref_p_1 (stmt
, &r
, tbaa_p
);
2307 /* Return true if store1 and store2 described by corresponding tuples
2308 <BASE, OFFSET, SIZE, MAX_SIZE> have the same size and store to the same
2312 same_addr_size_stores_p (tree base1
, poly_int64 offset1
, poly_int64 size1
,
2313 poly_int64 max_size1
,
2314 tree base2
, poly_int64 offset2
, poly_int64 size2
,
2315 poly_int64 max_size2
)
2317 /* Offsets need to be 0. */
2318 if (maybe_ne (offset1
, 0)
2319 || maybe_ne (offset2
, 0))
2322 bool base1_obj_p
= SSA_VAR_P (base1
);
2323 bool base2_obj_p
= SSA_VAR_P (base2
);
2325 /* We need one object. */
2326 if (base1_obj_p
== base2_obj_p
)
2328 tree obj
= base1_obj_p
? base1
: base2
;
2330 /* And we need one MEM_REF. */
2331 bool base1_memref_p
= TREE_CODE (base1
) == MEM_REF
;
2332 bool base2_memref_p
= TREE_CODE (base2
) == MEM_REF
;
2333 if (base1_memref_p
== base2_memref_p
)
2335 tree memref
= base1_memref_p
? base1
: base2
;
2337 /* Sizes need to be valid. */
2338 if (!known_size_p (max_size1
)
2339 || !known_size_p (max_size2
)
2340 || !known_size_p (size1
)
2341 || !known_size_p (size2
))
2344 /* Max_size needs to match size. */
2345 if (maybe_ne (max_size1
, size1
)
2346 || maybe_ne (max_size2
, size2
))
2349 /* Sizes need to match. */
2350 if (maybe_ne (size1
, size2
))
2354 /* Check that memref is a store to pointer with singleton points-to info. */
2355 if (!integer_zerop (TREE_OPERAND (memref
, 1)))
2357 tree ptr
= TREE_OPERAND (memref
, 0);
2358 if (TREE_CODE (ptr
) != SSA_NAME
)
2360 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (ptr
);
2361 unsigned int pt_uid
;
2363 || !pt_solution_singleton_or_null_p (&pi
->pt
, &pt_uid
))
2366 /* Be conservative with non-call exceptions when the address might
2368 if (cfun
->can_throw_non_call_exceptions
&& pi
->pt
.null
)
2371 /* Check that ptr points relative to obj. */
2372 unsigned int obj_uid
= DECL_PT_UID (obj
);
2373 if (obj_uid
!= pt_uid
)
2376 /* Check that the object size is the same as the store size. That ensures us
2377 that ptr points to the start of obj. */
2378 return (DECL_SIZE (obj
)
2379 && poly_int_tree_p (DECL_SIZE (obj
))
2380 && known_eq (wi::to_poly_offset (DECL_SIZE (obj
)), size1
));
2383 /* If STMT kills the memory reference REF return true, otherwise
2387 stmt_kills_ref_p (gimple
*stmt
, ao_ref
*ref
)
2389 if (!ao_ref_base (ref
))
2392 if (gimple_has_lhs (stmt
)
2393 && TREE_CODE (gimple_get_lhs (stmt
)) != SSA_NAME
2394 /* The assignment is not necessarily carried out if it can throw
2395 and we can catch it in the current function where we could inspect
2397 ??? We only need to care about the RHS throwing. For aggregate
2398 assignments or similar calls and non-call exceptions the LHS
2399 might throw as well. */
2400 && !stmt_can_throw_internal (cfun
, stmt
))
2402 tree lhs
= gimple_get_lhs (stmt
);
2403 /* If LHS is literally a base of the access we are done. */
2406 tree base
= ref
->ref
;
2407 tree innermost_dropped_array_ref
= NULL_TREE
;
2408 if (handled_component_p (base
))
2410 tree saved_lhs0
= NULL_TREE
;
2411 if (handled_component_p (lhs
))
2413 saved_lhs0
= TREE_OPERAND (lhs
, 0);
2414 TREE_OPERAND (lhs
, 0) = integer_zero_node
;
2418 /* Just compare the outermost handled component, if
2419 they are equal we have found a possible common
2421 tree saved_base0
= TREE_OPERAND (base
, 0);
2422 TREE_OPERAND (base
, 0) = integer_zero_node
;
2423 bool res
= operand_equal_p (lhs
, base
, 0);
2424 TREE_OPERAND (base
, 0) = saved_base0
;
2427 /* Remember if we drop an array-ref that we need to
2428 double-check not being at struct end. */
2429 if (TREE_CODE (base
) == ARRAY_REF
2430 || TREE_CODE (base
) == ARRAY_RANGE_REF
)
2431 innermost_dropped_array_ref
= base
;
2432 /* Otherwise drop handled components of the access. */
2435 while (handled_component_p (base
));
2437 TREE_OPERAND (lhs
, 0) = saved_lhs0
;
2439 /* Finally check if the lhs has the same address and size as the
2440 base candidate of the access. Watch out if we have dropped
2441 an array-ref that was at struct end, this means ref->ref may
2442 be outside of the TYPE_SIZE of its base. */
2443 if ((! innermost_dropped_array_ref
2444 || ! array_at_struct_end_p (innermost_dropped_array_ref
))
2446 || (((TYPE_SIZE (TREE_TYPE (lhs
))
2447 == TYPE_SIZE (TREE_TYPE (base
)))
2448 || (TYPE_SIZE (TREE_TYPE (lhs
))
2449 && TYPE_SIZE (TREE_TYPE (base
))
2450 && operand_equal_p (TYPE_SIZE (TREE_TYPE (lhs
)),
2451 TYPE_SIZE (TREE_TYPE (base
)),
2453 && operand_equal_p (lhs
, base
,
2455 | OEP_MATCH_SIDE_EFFECTS
))))
2459 /* Now look for non-literal equal bases with the restriction of
2460 handling constant offset and size. */
2461 /* For a must-alias check we need to be able to constrain
2462 the access properly. */
2463 if (!ref
->max_size_known_p ())
2465 poly_int64 size
, offset
, max_size
, ref_offset
= ref
->offset
;
2467 tree base
= get_ref_base_and_extent (lhs
, &offset
, &size
, &max_size
,
2469 /* We can get MEM[symbol: sZ, index: D.8862_1] here,
2470 so base == ref->base does not always hold. */
2471 if (base
!= ref
->base
)
2473 /* Try using points-to info. */
2474 if (same_addr_size_stores_p (base
, offset
, size
, max_size
, ref
->base
,
2475 ref
->offset
, ref
->size
, ref
->max_size
))
2478 /* If both base and ref->base are MEM_REFs, only compare the
2479 first operand, and if the second operand isn't equal constant,
2480 try to add the offsets into offset and ref_offset. */
2481 if (TREE_CODE (base
) == MEM_REF
&& TREE_CODE (ref
->base
) == MEM_REF
2482 && TREE_OPERAND (base
, 0) == TREE_OPERAND (ref
->base
, 0))
2484 if (!tree_int_cst_equal (TREE_OPERAND (base
, 1),
2485 TREE_OPERAND (ref
->base
, 1)))
2487 poly_offset_int off1
= mem_ref_offset (base
);
2488 off1
<<= LOG2_BITS_PER_UNIT
;
2490 poly_offset_int off2
= mem_ref_offset (ref
->base
);
2491 off2
<<= LOG2_BITS_PER_UNIT
;
2493 if (!off1
.to_shwi (&offset
) || !off2
.to_shwi (&ref_offset
))
2500 /* For a must-alias check we need to be able to constrain
2501 the access properly. */
2502 if (known_eq (size
, max_size
)
2503 && known_subrange_p (ref_offset
, ref
->max_size
, offset
, size
))
2507 if (is_gimple_call (stmt
))
2509 tree callee
= gimple_call_fndecl (stmt
);
2510 if (callee
!= NULL_TREE
2511 && gimple_call_builtin_p (stmt
, BUILT_IN_NORMAL
))
2512 switch (DECL_FUNCTION_CODE (callee
))
2516 tree ptr
= gimple_call_arg (stmt
, 0);
2517 tree base
= ao_ref_base (ref
);
2518 if (base
&& TREE_CODE (base
) == MEM_REF
2519 && TREE_OPERAND (base
, 0) == ptr
)
2524 case BUILT_IN_MEMCPY
:
2525 case BUILT_IN_MEMPCPY
:
2526 case BUILT_IN_MEMMOVE
:
2527 case BUILT_IN_MEMSET
:
2528 case BUILT_IN_MEMCPY_CHK
:
2529 case BUILT_IN_MEMPCPY_CHK
:
2530 case BUILT_IN_MEMMOVE_CHK
:
2531 case BUILT_IN_MEMSET_CHK
:
2532 case BUILT_IN_STRNCPY
:
2533 case BUILT_IN_STPNCPY
:
2535 /* For a must-alias check we need to be able to constrain
2536 the access properly. */
2537 if (!ref
->max_size_known_p ())
2539 tree dest
= gimple_call_arg (stmt
, 0);
2540 tree len
= gimple_call_arg (stmt
, 2);
2541 if (!poly_int_tree_p (len
))
2543 tree rbase
= ref
->base
;
2544 poly_offset_int roffset
= ref
->offset
;
2546 ao_ref_init_from_ptr_and_size (&dref
, dest
, len
);
2547 tree base
= ao_ref_base (&dref
);
2548 poly_offset_int offset
= dref
.offset
;
2549 if (!base
|| !known_size_p (dref
.size
))
2551 if (TREE_CODE (base
) == MEM_REF
)
2553 if (TREE_CODE (rbase
) != MEM_REF
)
2555 // Compare pointers.
2556 offset
+= mem_ref_offset (base
) << LOG2_BITS_PER_UNIT
;
2557 roffset
+= mem_ref_offset (rbase
) << LOG2_BITS_PER_UNIT
;
2558 base
= TREE_OPERAND (base
, 0);
2559 rbase
= TREE_OPERAND (rbase
, 0);
2562 && known_subrange_p (roffset
, ref
->max_size
, offset
,
2563 wi::to_poly_offset (len
)
2564 << LOG2_BITS_PER_UNIT
))
2569 case BUILT_IN_VA_END
:
2571 tree ptr
= gimple_call_arg (stmt
, 0);
2572 if (TREE_CODE (ptr
) == ADDR_EXPR
)
2574 tree base
= ao_ref_base (ref
);
2575 if (TREE_OPERAND (ptr
, 0) == base
)
2588 stmt_kills_ref_p (gimple
*stmt
, tree ref
)
2591 ao_ref_init (&r
, ref
);
2592 return stmt_kills_ref_p (stmt
, &r
);
2596 /* Walk the virtual use-def chain of VUSE until hitting the virtual operand
2597 TARGET or a statement clobbering the memory reference REF in which
2598 case false is returned. The walk starts with VUSE, one argument of PHI. */
2601 maybe_skip_until (gimple
*phi
, tree target
, ao_ref
*ref
,
2602 tree vuse
, unsigned int *cnt
, bitmap
*visited
,
2603 bool abort_on_visited
,
2604 void *(*translate
)(ao_ref
*, tree
, void *, bool *),
2607 basic_block bb
= gimple_bb (phi
);
2610 *visited
= BITMAP_ALLOC (NULL
);
2612 bitmap_set_bit (*visited
, SSA_NAME_VERSION (PHI_RESULT (phi
)));
2614 /* Walk until we hit the target. */
2615 while (vuse
!= target
)
2617 gimple
*def_stmt
= SSA_NAME_DEF_STMT (vuse
);
2618 /* Recurse for PHI nodes. */
2619 if (gimple_code (def_stmt
) == GIMPLE_PHI
)
2621 /* An already visited PHI node ends the walk successfully. */
2622 if (bitmap_bit_p (*visited
, SSA_NAME_VERSION (PHI_RESULT (def_stmt
))))
2623 return !abort_on_visited
;
2624 vuse
= get_continuation_for_phi (def_stmt
, ref
, cnt
,
2625 visited
, abort_on_visited
,
2631 else if (gimple_nop_p (def_stmt
))
2635 /* A clobbering statement or the end of the IL ends it failing. */
2637 if (stmt_may_clobber_ref_p_1 (def_stmt
, ref
))
2639 bool disambiguate_only
= true;
2641 && (*translate
) (ref
, vuse
, data
, &disambiguate_only
) == NULL
)
2647 /* If we reach a new basic-block see if we already skipped it
2648 in a previous walk that ended successfully. */
2649 if (gimple_bb (def_stmt
) != bb
)
2651 if (!bitmap_set_bit (*visited
, SSA_NAME_VERSION (vuse
)))
2652 return !abort_on_visited
;
2653 bb
= gimple_bb (def_stmt
);
2655 vuse
= gimple_vuse (def_stmt
);
2661 /* Starting from a PHI node for the virtual operand of the memory reference
2662 REF find a continuation virtual operand that allows to continue walking
2663 statements dominating PHI skipping only statements that cannot possibly
2664 clobber REF. Increments *CNT for each alias disambiguation done.
2665 Returns NULL_TREE if no suitable virtual operand can be found. */
2668 get_continuation_for_phi (gimple
*phi
, ao_ref
*ref
,
2669 unsigned int *cnt
, bitmap
*visited
,
2670 bool abort_on_visited
,
2671 void *(*translate
)(ao_ref
*, tree
, void *, bool *),
2674 unsigned nargs
= gimple_phi_num_args (phi
);
2676 /* Through a single-argument PHI we can simply look through. */
2678 return PHI_ARG_DEF (phi
, 0);
2680 /* For two or more arguments try to pairwise skip non-aliasing code
2681 until we hit the phi argument definition that dominates the other one. */
2682 basic_block phi_bb
= gimple_bb (phi
);
2686 /* Find a candidate for the virtual operand which definition
2687 dominates those of all others. */
2688 /* First look if any of the args themselves satisfy this. */
2689 for (i
= 0; i
< nargs
; ++i
)
2691 arg0
= PHI_ARG_DEF (phi
, i
);
2692 if (SSA_NAME_IS_DEFAULT_DEF (arg0
))
2694 basic_block def_bb
= gimple_bb (SSA_NAME_DEF_STMT (arg0
));
2695 if (def_bb
!= phi_bb
2696 && dominated_by_p (CDI_DOMINATORS
, phi_bb
, def_bb
))
2700 /* If not, look if we can reach such candidate by walking defs
2701 of a PHI arg without crossing other PHIs. */
2703 for (i
= 0; i
< nargs
; ++i
)
2705 arg0
= PHI_ARG_DEF (phi
, i
);
2706 gimple
*def
= SSA_NAME_DEF_STMT (arg0
);
2707 /* Backedges can't work. */
2708 if (dominated_by_p (CDI_DOMINATORS
,
2709 gimple_bb (def
), phi_bb
))
2712 if (gimple_code (def
) == GIMPLE_PHI
)
2714 while (! dominated_by_p (CDI_DOMINATORS
,
2715 phi_bb
, gimple_bb (def
)))
2717 arg0
= gimple_vuse (def
);
2718 if (SSA_NAME_IS_DEFAULT_DEF (arg0
))
2720 def
= SSA_NAME_DEF_STMT (arg0
);
2721 if (gimple_code (def
) == GIMPLE_PHI
)
2723 /* Do not try to look through arbitrarily complicated
2724 CFGs. For those looking for the first VUSE starting
2725 from the end of the immediate dominator of phi_bb
2726 is likely faster. */
2737 /* Then check against the found candidate. */
2738 for (i
= 0; i
< nargs
; ++i
)
2740 arg1
= PHI_ARG_DEF (phi
, i
);
2743 else if (! maybe_skip_until (phi
, arg0
, ref
, arg1
, cnt
, visited
,
2745 /* Do not translate when walking over
2749 gimple_bb (SSA_NAME_DEF_STMT (arg1
)),
2751 ? NULL
: translate
, data
))
2758 /* Based on the memory reference REF and its virtual use VUSE call
2759 WALKER for each virtual use that is equivalent to VUSE, including VUSE
2760 itself. That is, for each virtual use for which its defining statement
2761 does not clobber REF.
2763 WALKER is called with REF, the current virtual use and DATA. If
2764 WALKER returns non-NULL the walk stops and its result is returned.
2765 At the end of a non-successful walk NULL is returned.
2767 TRANSLATE if non-NULL is called with a pointer to REF, the virtual
2768 use which definition is a statement that may clobber REF and DATA.
2769 If TRANSLATE returns (void *)-1 the walk stops and NULL is returned.
2770 If TRANSLATE returns non-NULL the walk stops and its result is returned.
2771 If TRANSLATE returns NULL the walk continues and TRANSLATE is supposed
2772 to adjust REF and *DATA to make that valid.
2774 VALUEIZE if non-NULL is called with the next VUSE that is considered
2775 and return value is substituted for that. This can be used to
2776 implement optimistic value-numbering for example. Note that the
2777 VUSE argument is assumed to be valueized already.
2779 TODO: Cache the vector of equivalent vuses per ref, vuse pair. */
2782 walk_non_aliased_vuses (ao_ref
*ref
, tree vuse
,
2783 void *(*walker
)(ao_ref
*, tree
, unsigned int, void *),
2784 void *(*translate
)(ao_ref
*, tree
, void *, bool *),
2785 tree (*valueize
)(tree
),
2788 bitmap visited
= NULL
;
2790 unsigned int cnt
= 0;
2791 bool translated
= false;
2793 timevar_push (TV_ALIAS_STMT_WALK
);
2799 /* ??? Do we want to account this to TV_ALIAS_STMT_WALK? */
2800 res
= (*walker
) (ref
, vuse
, cnt
, data
);
2802 if (res
== (void *)-1)
2807 /* Lookup succeeded. */
2808 else if (res
!= NULL
)
2813 vuse
= valueize (vuse
);
2820 def_stmt
= SSA_NAME_DEF_STMT (vuse
);
2821 if (gimple_nop_p (def_stmt
))
2823 else if (gimple_code (def_stmt
) == GIMPLE_PHI
)
2824 vuse
= get_continuation_for_phi (def_stmt
, ref
, &cnt
,
2825 &visited
, translated
, translate
, data
);
2829 if (stmt_may_clobber_ref_p_1 (def_stmt
, ref
))
2833 bool disambiguate_only
= false;
2834 res
= (*translate
) (ref
, vuse
, data
, &disambiguate_only
);
2835 /* Failed lookup and translation. */
2836 if (res
== (void *)-1)
2841 /* Lookup succeeded. */
2842 else if (res
!= NULL
)
2844 /* Translation succeeded, continue walking. */
2845 translated
= translated
|| !disambiguate_only
;
2847 vuse
= gimple_vuse (def_stmt
);
2853 BITMAP_FREE (visited
);
2855 timevar_pop (TV_ALIAS_STMT_WALK
);
2861 /* Based on the memory reference REF call WALKER for each vdef which
2862 defining statement may clobber REF, starting with VDEF. If REF
2863 is NULL_TREE, each defining statement is visited.
2865 WALKER is called with REF, the current vdef and DATA. If WALKER
2866 returns true the walk is stopped, otherwise it continues.
2868 If function entry is reached, FUNCTION_ENTRY_REACHED is set to true.
2869 The pointer may be NULL and then we do not track this information.
2871 At PHI nodes walk_aliased_vdefs forks into one walk for reach
2872 PHI argument (but only one walk continues on merge points), the
2873 return value is true if any of the walks was successful.
2875 The function returns the number of statements walked or -1 if
2876 LIMIT stmts were walked and the walk was aborted at this point.
2877 If LIMIT is zero the walk is not aborted. */
2880 walk_aliased_vdefs_1 (ao_ref
*ref
, tree vdef
,
2881 bool (*walker
)(ao_ref
*, tree
, void *), void *data
,
2882 bitmap
*visited
, unsigned int cnt
,
2883 bool *function_entry_reached
, unsigned limit
)
2887 gimple
*def_stmt
= SSA_NAME_DEF_STMT (vdef
);
2890 && !bitmap_set_bit (*visited
, SSA_NAME_VERSION (vdef
)))
2893 if (gimple_nop_p (def_stmt
))
2895 if (function_entry_reached
)
2896 *function_entry_reached
= true;
2899 else if (gimple_code (def_stmt
) == GIMPLE_PHI
)
2903 *visited
= BITMAP_ALLOC (NULL
);
2904 for (i
= 0; i
< gimple_phi_num_args (def_stmt
); ++i
)
2906 int res
= walk_aliased_vdefs_1 (ref
,
2907 gimple_phi_arg_def (def_stmt
, i
),
2908 walker
, data
, visited
, cnt
,
2909 function_entry_reached
, limit
);
2917 /* ??? Do we want to account this to TV_ALIAS_STMT_WALK? */
2922 || stmt_may_clobber_ref_p_1 (def_stmt
, ref
))
2923 && (*walker
) (ref
, vdef
, data
))
2926 vdef
= gimple_vuse (def_stmt
);
2932 walk_aliased_vdefs (ao_ref
*ref
, tree vdef
,
2933 bool (*walker
)(ao_ref
*, tree
, void *), void *data
,
2935 bool *function_entry_reached
, unsigned int limit
)
2937 bitmap local_visited
= NULL
;
2940 timevar_push (TV_ALIAS_STMT_WALK
);
2942 if (function_entry_reached
)
2943 *function_entry_reached
= false;
2945 ret
= walk_aliased_vdefs_1 (ref
, vdef
, walker
, data
,
2946 visited
? visited
: &local_visited
, 0,
2947 function_entry_reached
, limit
);
2949 BITMAP_FREE (local_visited
);
2951 timevar_pop (TV_ALIAS_STMT_WALK
);