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
);
819 poly_int64 offadj
, sztmp
, msztmp
;
821 get_ref_base_and_extent (*refp
, &offadj
, &sztmp
, &msztmp
, &reverse
);
823 get_ref_base_and_extent (base1
, &offadj
, &sztmp
, &msztmp
, &reverse
);
825 return ranges_maybe_overlap_p (offset1
, max_size1
, offset2
, max_size2
);
828 /* If we didn't find a common base, try the other way around. */
830 while (handled_component_p (*refp
)
831 && same_type_for_tbaa (TREE_TYPE (*refp
), type2
) == 0)
832 refp
= &TREE_OPERAND (*refp
, 0);
833 same_p2
= same_type_for_tbaa (TREE_TYPE (*refp
), type2
);
836 poly_int64 offadj
, sztmp
, msztmp
;
839 get_ref_base_and_extent (*refp
, &offadj
, &sztmp
, &msztmp
, &reverse
);
841 get_ref_base_and_extent (base2
, &offadj
, &sztmp
, &msztmp
, &reverse
);
843 return ranges_maybe_overlap_p (offset1
, max_size1
,
847 /* In the remaining test we assume that there is no overlapping type
848 at all. So if we are unsure, we need to give up. */
849 if (same_p
== -1 || same_p2
== -1)
852 /* If we have two type access paths B1.path1 and B2.path2 they may
853 only alias if either B1 is in B2.path2 or B2 is in B1.path1.
854 But we can still have a path that goes B1.path1...B2.path2 with
855 a part that we do not see. So we can only disambiguate now
856 if there is no B2 in the tail of path1 and no B1 on the
858 if (base1_alias_set
== ref2_alias_set
859 || alias_set_subset_of (base1_alias_set
, ref2_alias_set
))
861 /* If this is ptr vs. decl then we know there is no ptr ... decl path. */
863 return (base2_alias_set
== ref1_alias_set
864 || alias_set_subset_of (base2_alias_set
, ref1_alias_set
));
868 /* Return true if we can determine that component references REF1 and REF2,
869 that are within a common DECL, cannot overlap. */
872 nonoverlapping_component_refs_of_decl_p (tree ref1
, tree ref2
)
874 auto_vec
<tree
, 16> component_refs1
;
875 auto_vec
<tree
, 16> component_refs2
;
877 /* Create the stack of handled components for REF1. */
878 while (handled_component_p (ref1
))
880 component_refs1
.safe_push (ref1
);
881 ref1
= TREE_OPERAND (ref1
, 0);
883 if (TREE_CODE (ref1
) == MEM_REF
)
885 if (!integer_zerop (TREE_OPERAND (ref1
, 1)))
887 ref1
= TREE_OPERAND (TREE_OPERAND (ref1
, 0), 0);
890 /* Create the stack of handled components for REF2. */
891 while (handled_component_p (ref2
))
893 component_refs2
.safe_push (ref2
);
894 ref2
= TREE_OPERAND (ref2
, 0);
896 if (TREE_CODE (ref2
) == MEM_REF
)
898 if (!integer_zerop (TREE_OPERAND (ref2
, 1)))
900 ref2
= TREE_OPERAND (TREE_OPERAND (ref2
, 0), 0);
903 /* Bases must be either same or uncomparable. */
904 gcc_checking_assert (ref1
== ref2
905 || (DECL_P (ref1
) && DECL_P (ref2
)
906 && compare_base_decls (ref1
, ref2
) != 0));
908 /* Pop the stacks in parallel and examine the COMPONENT_REFs of the same
909 rank. This is sufficient because we start from the same DECL and you
910 cannot reference several fields at a time with COMPONENT_REFs (unlike
911 with ARRAY_RANGE_REFs for arrays) so you always need the same number
912 of them to access a sub-component, unless you're in a union, in which
913 case the return value will precisely be false. */
918 if (component_refs1
.is_empty ())
920 ref1
= component_refs1
.pop ();
922 while (!RECORD_OR_UNION_TYPE_P (TREE_TYPE (TREE_OPERAND (ref1
, 0))));
926 if (component_refs2
.is_empty ())
928 ref2
= component_refs2
.pop ();
930 while (!RECORD_OR_UNION_TYPE_P (TREE_TYPE (TREE_OPERAND (ref2
, 0))));
932 /* Beware of BIT_FIELD_REF. */
933 if (TREE_CODE (ref1
) != COMPONENT_REF
934 || TREE_CODE (ref2
) != COMPONENT_REF
)
937 tree field1
= TREE_OPERAND (ref1
, 1);
938 tree field2
= TREE_OPERAND (ref2
, 1);
940 /* ??? We cannot simply use the type of operand #0 of the refs here
941 as the Fortran compiler smuggles type punning into COMPONENT_REFs
942 for common blocks instead of using unions like everyone else. */
943 tree type1
= DECL_CONTEXT (field1
);
944 tree type2
= DECL_CONTEXT (field2
);
946 /* We cannot disambiguate fields in a union or qualified union. */
947 if (type1
!= type2
|| TREE_CODE (type1
) != RECORD_TYPE
)
950 if (field1
!= field2
)
952 /* A field and its representative need to be considered the
954 if (DECL_BIT_FIELD_REPRESENTATIVE (field1
) == field2
955 || DECL_BIT_FIELD_REPRESENTATIVE (field2
) == field1
)
957 /* Different fields of the same record type cannot overlap.
958 ??? Bitfields can overlap at RTL level so punt on them. */
959 if (DECL_BIT_FIELD (field1
) && DECL_BIT_FIELD (field2
))
968 /* qsort compare function to sort FIELD_DECLs after their
969 DECL_FIELD_CONTEXT TYPE_UID. */
972 ncr_compar (const void *field1_
, const void *field2_
)
974 const_tree field1
= *(const_tree
*) const_cast <void *>(field1_
);
975 const_tree field2
= *(const_tree
*) const_cast <void *>(field2_
);
976 unsigned int uid1
= TYPE_UID (DECL_FIELD_CONTEXT (field1
));
977 unsigned int uid2
= TYPE_UID (DECL_FIELD_CONTEXT (field2
));
980 else if (uid1
> uid2
)
985 /* Return true if we can determine that the fields referenced cannot
986 overlap for any pair of objects. */
989 nonoverlapping_component_refs_p (const_tree x
, const_tree y
)
991 if (!flag_strict_aliasing
993 || TREE_CODE (x
) != COMPONENT_REF
994 || TREE_CODE (y
) != COMPONENT_REF
)
997 auto_vec
<const_tree
, 16> fieldsx
;
998 while (TREE_CODE (x
) == COMPONENT_REF
)
1000 tree field
= TREE_OPERAND (x
, 1);
1001 tree type
= DECL_FIELD_CONTEXT (field
);
1002 if (TREE_CODE (type
) == RECORD_TYPE
)
1003 fieldsx
.safe_push (field
);
1004 x
= TREE_OPERAND (x
, 0);
1006 if (fieldsx
.length () == 0)
1008 auto_vec
<const_tree
, 16> fieldsy
;
1009 while (TREE_CODE (y
) == COMPONENT_REF
)
1011 tree field
= TREE_OPERAND (y
, 1);
1012 tree type
= DECL_FIELD_CONTEXT (field
);
1013 if (TREE_CODE (type
) == RECORD_TYPE
)
1014 fieldsy
.safe_push (TREE_OPERAND (y
, 1));
1015 y
= TREE_OPERAND (y
, 0);
1017 if (fieldsy
.length () == 0)
1020 /* Most common case first. */
1021 if (fieldsx
.length () == 1
1022 && fieldsy
.length () == 1)
1023 return ((DECL_FIELD_CONTEXT (fieldsx
[0])
1024 == DECL_FIELD_CONTEXT (fieldsy
[0]))
1025 && fieldsx
[0] != fieldsy
[0]
1026 && !(DECL_BIT_FIELD (fieldsx
[0]) && DECL_BIT_FIELD (fieldsy
[0])));
1028 if (fieldsx
.length () == 2)
1030 if (ncr_compar (&fieldsx
[0], &fieldsx
[1]) == 1)
1031 std::swap (fieldsx
[0], fieldsx
[1]);
1034 fieldsx
.qsort (ncr_compar
);
1036 if (fieldsy
.length () == 2)
1038 if (ncr_compar (&fieldsy
[0], &fieldsy
[1]) == 1)
1039 std::swap (fieldsy
[0], fieldsy
[1]);
1042 fieldsy
.qsort (ncr_compar
);
1044 unsigned i
= 0, j
= 0;
1047 const_tree fieldx
= fieldsx
[i
];
1048 const_tree fieldy
= fieldsy
[j
];
1049 tree typex
= DECL_FIELD_CONTEXT (fieldx
);
1050 tree typey
= DECL_FIELD_CONTEXT (fieldy
);
1053 /* We're left with accessing different fields of a structure,
1054 no possible overlap. */
1055 if (fieldx
!= fieldy
)
1057 /* A field and its representative need to be considered the
1059 if (DECL_BIT_FIELD_REPRESENTATIVE (fieldx
) == fieldy
1060 || DECL_BIT_FIELD_REPRESENTATIVE (fieldy
) == fieldx
)
1062 /* Different fields of the same record type cannot overlap.
1063 ??? Bitfields can overlap at RTL level so punt on them. */
1064 if (DECL_BIT_FIELD (fieldx
) && DECL_BIT_FIELD (fieldy
))
1069 if (TYPE_UID (typex
) < TYPE_UID (typey
))
1072 if (i
== fieldsx
.length ())
1078 if (j
== fieldsy
.length ())
1088 /* Return true if two memory references based on the variables BASE1
1089 and BASE2 constrained to [OFFSET1, OFFSET1 + MAX_SIZE1) and
1090 [OFFSET2, OFFSET2 + MAX_SIZE2) may alias. REF1 and REF2
1091 if non-NULL are the complete memory reference trees. */
1094 decl_refs_may_alias_p (tree ref1
, tree base1
,
1095 poly_int64 offset1
, poly_int64 max_size1
,
1096 tree ref2
, tree base2
,
1097 poly_int64 offset2
, poly_int64 max_size2
)
1099 gcc_checking_assert (DECL_P (base1
) && DECL_P (base2
));
1101 /* If both references are based on different variables, they cannot alias. */
1102 if (compare_base_decls (base1
, base2
) == 0)
1105 /* If both references are based on the same variable, they cannot alias if
1106 the accesses do not overlap. */
1107 if (!ranges_maybe_overlap_p (offset1
, max_size1
, offset2
, max_size2
))
1110 /* For components with variable position, the above test isn't sufficient,
1111 so we disambiguate component references manually. */
1113 && handled_component_p (ref1
) && handled_component_p (ref2
)
1114 && nonoverlapping_component_refs_of_decl_p (ref1
, ref2
))
1120 /* Return true if an indirect reference based on *PTR1 constrained
1121 to [OFFSET1, OFFSET1 + MAX_SIZE1) may alias a variable based on BASE2
1122 constrained to [OFFSET2, OFFSET2 + MAX_SIZE2). *PTR1 and BASE2 have
1123 the alias sets BASE1_ALIAS_SET and BASE2_ALIAS_SET which can be -1
1124 in which case they are computed on-demand. REF1 and REF2
1125 if non-NULL are the complete memory reference trees. */
1128 indirect_ref_may_alias_decl_p (tree ref1 ATTRIBUTE_UNUSED
, tree base1
,
1129 poly_int64 offset1
, poly_int64 max_size1
,
1130 alias_set_type ref1_alias_set
,
1131 alias_set_type base1_alias_set
,
1132 tree ref2 ATTRIBUTE_UNUSED
, tree base2
,
1133 poly_int64 offset2
, poly_int64 max_size2
,
1134 alias_set_type ref2_alias_set
,
1135 alias_set_type base2_alias_set
, bool tbaa_p
)
1138 tree ptrtype1
, dbase2
;
1140 gcc_checking_assert ((TREE_CODE (base1
) == MEM_REF
1141 || TREE_CODE (base1
) == TARGET_MEM_REF
)
1144 ptr1
= TREE_OPERAND (base1
, 0);
1145 poly_offset_int moff
= mem_ref_offset (base1
) << LOG2_BITS_PER_UNIT
;
1147 /* If only one reference is based on a variable, they cannot alias if
1148 the pointer access is beyond the extent of the variable access.
1149 (the pointer base cannot validly point to an offset less than zero
1151 ??? IVOPTs creates bases that do not honor this restriction,
1152 so do not apply this optimization for TARGET_MEM_REFs. */
1153 if (TREE_CODE (base1
) != TARGET_MEM_REF
1154 && !ranges_maybe_overlap_p (offset1
+ moff
, -1, offset2
, max_size2
))
1156 /* They also cannot alias if the pointer may not point to the decl. */
1157 if (!ptr_deref_may_alias_decl_p (ptr1
, base2
))
1160 /* Disambiguations that rely on strict aliasing rules follow. */
1161 if (!flag_strict_aliasing
|| !tbaa_p
)
1164 ptrtype1
= TREE_TYPE (TREE_OPERAND (base1
, 1));
1166 /* If the alias set for a pointer access is zero all bets are off. */
1167 if (base1_alias_set
== 0)
1170 /* When we are trying to disambiguate an access with a pointer dereference
1171 as base versus one with a decl as base we can use both the size
1172 of the decl and its dynamic type for extra disambiguation.
1173 ??? We do not know anything about the dynamic type of the decl
1174 other than that its alias-set contains base2_alias_set as a subset
1175 which does not help us here. */
1176 /* As we know nothing useful about the dynamic type of the decl just
1177 use the usual conflict check rather than a subset test.
1178 ??? We could introduce -fvery-strict-aliasing when the language
1179 does not allow decls to have a dynamic type that differs from their
1180 static type. Then we can check
1181 !alias_set_subset_of (base1_alias_set, base2_alias_set) instead. */
1182 if (base1_alias_set
!= base2_alias_set
1183 && !alias_sets_conflict_p (base1_alias_set
, base2_alias_set
))
1185 /* If the size of the access relevant for TBAA through the pointer
1186 is bigger than the size of the decl we can't possibly access the
1187 decl via that pointer. */
1188 if (DECL_SIZE (base2
) && COMPLETE_TYPE_P (TREE_TYPE (ptrtype1
))
1189 && poly_int_tree_p (DECL_SIZE (base2
))
1190 && poly_int_tree_p (TYPE_SIZE (TREE_TYPE (ptrtype1
)))
1191 /* ??? This in turn may run afoul when a decl of type T which is
1192 a member of union type U is accessed through a pointer to
1193 type U and sizeof T is smaller than sizeof U. */
1194 && TREE_CODE (TREE_TYPE (ptrtype1
)) != UNION_TYPE
1195 && TREE_CODE (TREE_TYPE (ptrtype1
)) != QUAL_UNION_TYPE
1196 && known_lt (wi::to_poly_widest (DECL_SIZE (base2
)),
1197 wi::to_poly_widest (TYPE_SIZE (TREE_TYPE (ptrtype1
)))))
1203 /* If the decl is accessed via a MEM_REF, reconstruct the base
1204 we can use for TBAA and an appropriately adjusted offset. */
1206 while (handled_component_p (dbase2
))
1207 dbase2
= TREE_OPERAND (dbase2
, 0);
1208 poly_int64 doffset1
= offset1
;
1209 poly_offset_int doffset2
= offset2
;
1210 if (TREE_CODE (dbase2
) == MEM_REF
1211 || TREE_CODE (dbase2
) == TARGET_MEM_REF
)
1212 doffset2
-= mem_ref_offset (dbase2
) << LOG2_BITS_PER_UNIT
;
1214 /* If either reference is view-converted, give up now. */
1215 if (same_type_for_tbaa (TREE_TYPE (base1
), TREE_TYPE (ptrtype1
)) != 1
1216 || same_type_for_tbaa (TREE_TYPE (dbase2
), TREE_TYPE (base2
)) != 1)
1219 /* If both references are through the same type, they do not alias
1220 if the accesses do not overlap. This does extra disambiguation
1221 for mixed/pointer accesses but requires strict aliasing.
1222 For MEM_REFs we require that the component-ref offset we computed
1223 is relative to the start of the type which we ensure by
1224 comparing rvalue and access type and disregarding the constant
1226 if ((TREE_CODE (base1
) != TARGET_MEM_REF
1227 || (!TMR_INDEX (base1
) && !TMR_INDEX2 (base1
)))
1228 && same_type_for_tbaa (TREE_TYPE (base1
), TREE_TYPE (dbase2
)) == 1)
1229 return ranges_maybe_overlap_p (doffset1
, max_size1
, doffset2
, max_size2
);
1232 && nonoverlapping_component_refs_p (ref1
, ref2
))
1235 /* Do access-path based disambiguation. */
1237 && (handled_component_p (ref1
) || handled_component_p (ref2
)))
1238 return aliasing_component_refs_p (ref1
,
1239 ref1_alias_set
, base1_alias_set
,
1242 ref2_alias_set
, base2_alias_set
,
1243 offset2
, max_size2
, true);
1248 /* Return true if two indirect references based on *PTR1
1249 and *PTR2 constrained to [OFFSET1, OFFSET1 + MAX_SIZE1) and
1250 [OFFSET2, OFFSET2 + MAX_SIZE2) may alias. *PTR1 and *PTR2 have
1251 the alias sets BASE1_ALIAS_SET and BASE2_ALIAS_SET which can be -1
1252 in which case they are computed on-demand. REF1 and REF2
1253 if non-NULL are the complete memory reference trees. */
1256 indirect_refs_may_alias_p (tree ref1 ATTRIBUTE_UNUSED
, tree base1
,
1257 poly_int64 offset1
, poly_int64 max_size1
,
1258 alias_set_type ref1_alias_set
,
1259 alias_set_type base1_alias_set
,
1260 tree ref2 ATTRIBUTE_UNUSED
, tree base2
,
1261 poly_int64 offset2
, poly_int64 max_size2
,
1262 alias_set_type ref2_alias_set
,
1263 alias_set_type base2_alias_set
, bool tbaa_p
)
1267 tree ptrtype1
, ptrtype2
;
1269 gcc_checking_assert ((TREE_CODE (base1
) == MEM_REF
1270 || TREE_CODE (base1
) == TARGET_MEM_REF
)
1271 && (TREE_CODE (base2
) == MEM_REF
1272 || TREE_CODE (base2
) == TARGET_MEM_REF
));
1274 ptr1
= TREE_OPERAND (base1
, 0);
1275 ptr2
= TREE_OPERAND (base2
, 0);
1277 /* If both bases are based on pointers they cannot alias if they may not
1278 point to the same memory object or if they point to the same object
1279 and the accesses do not overlap. */
1280 if ((!cfun
|| gimple_in_ssa_p (cfun
))
1281 && operand_equal_p (ptr1
, ptr2
, 0)
1282 && (((TREE_CODE (base1
) != TARGET_MEM_REF
1283 || (!TMR_INDEX (base1
) && !TMR_INDEX2 (base1
)))
1284 && (TREE_CODE (base2
) != TARGET_MEM_REF
1285 || (!TMR_INDEX (base2
) && !TMR_INDEX2 (base2
))))
1286 || (TREE_CODE (base1
) == TARGET_MEM_REF
1287 && TREE_CODE (base2
) == TARGET_MEM_REF
1288 && (TMR_STEP (base1
) == TMR_STEP (base2
)
1289 || (TMR_STEP (base1
) && TMR_STEP (base2
)
1290 && operand_equal_p (TMR_STEP (base1
),
1291 TMR_STEP (base2
), 0)))
1292 && (TMR_INDEX (base1
) == TMR_INDEX (base2
)
1293 || (TMR_INDEX (base1
) && TMR_INDEX (base2
)
1294 && operand_equal_p (TMR_INDEX (base1
),
1295 TMR_INDEX (base2
), 0)))
1296 && (TMR_INDEX2 (base1
) == TMR_INDEX2 (base2
)
1297 || (TMR_INDEX2 (base1
) && TMR_INDEX2 (base2
)
1298 && operand_equal_p (TMR_INDEX2 (base1
),
1299 TMR_INDEX2 (base2
), 0))))))
1301 poly_offset_int moff1
= mem_ref_offset (base1
) << LOG2_BITS_PER_UNIT
;
1302 poly_offset_int moff2
= mem_ref_offset (base2
) << LOG2_BITS_PER_UNIT
;
1303 return ranges_maybe_overlap_p (offset1
+ moff1
, max_size1
,
1304 offset2
+ moff2
, max_size2
);
1306 if (!ptr_derefs_may_alias_p (ptr1
, ptr2
))
1309 /* Disambiguations that rely on strict aliasing rules follow. */
1310 if (!flag_strict_aliasing
|| !tbaa_p
)
1313 ptrtype1
= TREE_TYPE (TREE_OPERAND (base1
, 1));
1314 ptrtype2
= TREE_TYPE (TREE_OPERAND (base2
, 1));
1316 /* If the alias set for a pointer access is zero all bets are off. */
1317 if (base1_alias_set
== 0
1318 || base2_alias_set
== 0)
1321 /* If both references are through the same type, they do not alias
1322 if the accesses do not overlap. This does extra disambiguation
1323 for mixed/pointer accesses but requires strict aliasing. */
1324 if ((TREE_CODE (base1
) != TARGET_MEM_REF
1325 || (!TMR_INDEX (base1
) && !TMR_INDEX2 (base1
)))
1326 && (TREE_CODE (base2
) != TARGET_MEM_REF
1327 || (!TMR_INDEX (base2
) && !TMR_INDEX2 (base2
)))
1328 && same_type_for_tbaa (TREE_TYPE (base1
), TREE_TYPE (ptrtype1
)) == 1
1329 && same_type_for_tbaa (TREE_TYPE (base2
), TREE_TYPE (ptrtype2
)) == 1
1330 && same_type_for_tbaa (TREE_TYPE (ptrtype1
),
1331 TREE_TYPE (ptrtype2
)) == 1
1332 /* But avoid treating arrays as "objects", instead assume they
1333 can overlap by an exact multiple of their element size. */
1334 && TREE_CODE (TREE_TYPE (ptrtype1
)) != ARRAY_TYPE
)
1335 return ranges_maybe_overlap_p (offset1
, max_size1
, offset2
, max_size2
);
1337 /* Do type-based disambiguation. */
1338 if (base1_alias_set
!= base2_alias_set
1339 && !alias_sets_conflict_p (base1_alias_set
, base2_alias_set
))
1342 /* If either reference is view-converted, give up now. */
1343 if (same_type_for_tbaa (TREE_TYPE (base1
), TREE_TYPE (ptrtype1
)) != 1
1344 || same_type_for_tbaa (TREE_TYPE (base2
), TREE_TYPE (ptrtype2
)) != 1)
1348 && nonoverlapping_component_refs_p (ref1
, ref2
))
1351 /* Do access-path based disambiguation. */
1353 && (handled_component_p (ref1
) || handled_component_p (ref2
)))
1354 return aliasing_component_refs_p (ref1
,
1355 ref1_alias_set
, base1_alias_set
,
1358 ref2_alias_set
, base2_alias_set
,
1359 offset2
, max_size2
, false);
1364 /* Return true, if the two memory references REF1 and REF2 may alias. */
1367 refs_may_alias_p_1 (ao_ref
*ref1
, ao_ref
*ref2
, bool tbaa_p
)
1370 poly_int64 offset1
= 0, offset2
= 0;
1371 poly_int64 max_size1
= -1, max_size2
= -1;
1372 bool var1_p
, var2_p
, ind1_p
, ind2_p
;
1374 gcc_checking_assert ((!ref1
->ref
1375 || TREE_CODE (ref1
->ref
) == SSA_NAME
1376 || DECL_P (ref1
->ref
)
1377 || TREE_CODE (ref1
->ref
) == STRING_CST
1378 || handled_component_p (ref1
->ref
)
1379 || TREE_CODE (ref1
->ref
) == MEM_REF
1380 || TREE_CODE (ref1
->ref
) == TARGET_MEM_REF
)
1382 || TREE_CODE (ref2
->ref
) == SSA_NAME
1383 || DECL_P (ref2
->ref
)
1384 || TREE_CODE (ref2
->ref
) == STRING_CST
1385 || handled_component_p (ref2
->ref
)
1386 || TREE_CODE (ref2
->ref
) == MEM_REF
1387 || TREE_CODE (ref2
->ref
) == TARGET_MEM_REF
));
1389 /* Decompose the references into their base objects and the access. */
1390 base1
= ao_ref_base (ref1
);
1391 offset1
= ref1
->offset
;
1392 max_size1
= ref1
->max_size
;
1393 base2
= ao_ref_base (ref2
);
1394 offset2
= ref2
->offset
;
1395 max_size2
= ref2
->max_size
;
1397 /* We can end up with registers or constants as bases for example from
1398 *D.1663_44 = VIEW_CONVERT_EXPR<struct DB_LSN>(__tmp$B0F64_59);
1399 which is seen as a struct copy. */
1400 if (TREE_CODE (base1
) == SSA_NAME
1401 || TREE_CODE (base1
) == CONST_DECL
1402 || TREE_CODE (base1
) == CONSTRUCTOR
1403 || TREE_CODE (base1
) == ADDR_EXPR
1404 || CONSTANT_CLASS_P (base1
)
1405 || TREE_CODE (base2
) == SSA_NAME
1406 || TREE_CODE (base2
) == CONST_DECL
1407 || TREE_CODE (base2
) == CONSTRUCTOR
1408 || TREE_CODE (base2
) == ADDR_EXPR
1409 || CONSTANT_CLASS_P (base2
))
1412 /* We can end up referring to code via function and label decls.
1413 As we likely do not properly track code aliases conservatively
1415 if (TREE_CODE (base1
) == FUNCTION_DECL
1416 || TREE_CODE (base1
) == LABEL_DECL
1417 || TREE_CODE (base2
) == FUNCTION_DECL
1418 || TREE_CODE (base2
) == LABEL_DECL
)
1421 /* Two volatile accesses always conflict. */
1422 if (ref1
->volatile_p
1423 && ref2
->volatile_p
)
1426 /* Defer to simple offset based disambiguation if we have
1427 references based on two decls. Do this before defering to
1428 TBAA to handle must-alias cases in conformance with the
1429 GCC extension of allowing type-punning through unions. */
1430 var1_p
= DECL_P (base1
);
1431 var2_p
= DECL_P (base2
);
1432 if (var1_p
&& var2_p
)
1433 return decl_refs_may_alias_p (ref1
->ref
, base1
, offset1
, max_size1
,
1434 ref2
->ref
, base2
, offset2
, max_size2
);
1436 /* Handle restrict based accesses.
1437 ??? ao_ref_base strips inner MEM_REF [&decl], recover from that
1439 tree rbase1
= base1
;
1440 tree rbase2
= base2
;
1445 while (handled_component_p (rbase1
))
1446 rbase1
= TREE_OPERAND (rbase1
, 0);
1452 while (handled_component_p (rbase2
))
1453 rbase2
= TREE_OPERAND (rbase2
, 0);
1455 if (rbase1
&& rbase2
1456 && (TREE_CODE (base1
) == MEM_REF
|| TREE_CODE (base1
) == TARGET_MEM_REF
)
1457 && (TREE_CODE (base2
) == MEM_REF
|| TREE_CODE (base2
) == TARGET_MEM_REF
)
1458 /* If the accesses are in the same restrict clique... */
1459 && MR_DEPENDENCE_CLIQUE (base1
) == MR_DEPENDENCE_CLIQUE (base2
)
1460 /* But based on different pointers they do not alias. */
1461 && MR_DEPENDENCE_BASE (base1
) != MR_DEPENDENCE_BASE (base2
))
1464 ind1_p
= (TREE_CODE (base1
) == MEM_REF
1465 || TREE_CODE (base1
) == TARGET_MEM_REF
);
1466 ind2_p
= (TREE_CODE (base2
) == MEM_REF
1467 || TREE_CODE (base2
) == TARGET_MEM_REF
);
1469 /* Canonicalize the pointer-vs-decl case. */
1470 if (ind1_p
&& var2_p
)
1472 std::swap (offset1
, offset2
);
1473 std::swap (max_size1
, max_size2
);
1474 std::swap (base1
, base2
);
1475 std::swap (ref1
, ref2
);
1482 /* First defer to TBAA if possible. */
1484 && flag_strict_aliasing
1485 && !alias_sets_conflict_p (ao_ref_alias_set (ref1
),
1486 ao_ref_alias_set (ref2
)))
1489 /* If the reference is based on a pointer that points to memory
1490 that may not be written to then the other reference cannot possibly
1492 if ((TREE_CODE (TREE_OPERAND (base2
, 0)) == SSA_NAME
1493 && SSA_NAME_POINTS_TO_READONLY_MEMORY (TREE_OPERAND (base2
, 0)))
1495 && TREE_CODE (TREE_OPERAND (base1
, 0)) == SSA_NAME
1496 && SSA_NAME_POINTS_TO_READONLY_MEMORY (TREE_OPERAND (base1
, 0))))
1499 /* Dispatch to the pointer-vs-decl or pointer-vs-pointer disambiguators. */
1500 if (var1_p
&& ind2_p
)
1501 return indirect_ref_may_alias_decl_p (ref2
->ref
, base2
,
1503 ao_ref_alias_set (ref2
),
1504 ao_ref_base_alias_set (ref2
),
1507 ao_ref_alias_set (ref1
),
1508 ao_ref_base_alias_set (ref1
),
1510 else if (ind1_p
&& ind2_p
)
1511 return indirect_refs_may_alias_p (ref1
->ref
, base1
,
1513 ao_ref_alias_set (ref1
),
1514 ao_ref_base_alias_set (ref1
),
1517 ao_ref_alias_set (ref2
),
1518 ao_ref_base_alias_set (ref2
),
1525 refs_may_alias_p (tree ref1
, ao_ref
*ref2
, bool tbaa_p
)
1528 ao_ref_init (&r1
, ref1
);
1529 return refs_may_alias_p_1 (&r1
, ref2
, tbaa_p
);
1533 refs_may_alias_p (tree ref1
, tree ref2
, bool tbaa_p
)
1537 ao_ref_init (&r1
, ref1
);
1538 ao_ref_init (&r2
, ref2
);
1539 res
= refs_may_alias_p_1 (&r1
, &r2
, tbaa_p
);
1541 ++alias_stats
.refs_may_alias_p_may_alias
;
1543 ++alias_stats
.refs_may_alias_p_no_alias
;
1547 /* Returns true if there is a anti-dependence for the STORE that
1548 executes after the LOAD. */
1551 refs_anti_dependent_p (tree load
, tree store
)
1554 ao_ref_init (&r1
, load
);
1555 ao_ref_init (&r2
, store
);
1556 return refs_may_alias_p_1 (&r1
, &r2
, false);
1559 /* Returns true if there is a output dependence for the stores
1560 STORE1 and STORE2. */
1563 refs_output_dependent_p (tree store1
, tree store2
)
1566 ao_ref_init (&r1
, store1
);
1567 ao_ref_init (&r2
, store2
);
1568 return refs_may_alias_p_1 (&r1
, &r2
, false);
1571 /* If the call CALL may use the memory reference REF return true,
1572 otherwise return false. */
1575 ref_maybe_used_by_call_p_1 (gcall
*call
, ao_ref
*ref
, bool tbaa_p
)
1579 int flags
= gimple_call_flags (call
);
1581 /* Const functions without a static chain do not implicitly use memory. */
1582 if (!gimple_call_chain (call
)
1583 && (flags
& (ECF_CONST
|ECF_NOVOPS
)))
1586 base
= ao_ref_base (ref
);
1590 /* A call that is not without side-effects might involve volatile
1591 accesses and thus conflicts with all other volatile accesses. */
1592 if (ref
->volatile_p
)
1595 /* If the reference is based on a decl that is not aliased the call
1596 cannot possibly use it. */
1598 && !may_be_aliased (base
)
1599 /* But local statics can be used through recursion. */
1600 && !is_global_var (base
))
1603 callee
= gimple_call_fndecl (call
);
1605 /* Handle those builtin functions explicitly that do not act as
1606 escape points. See tree-ssa-structalias.c:find_func_aliases
1607 for the list of builtins we might need to handle here. */
1608 if (callee
!= NULL_TREE
1609 && gimple_call_builtin_p (call
, BUILT_IN_NORMAL
))
1610 switch (DECL_FUNCTION_CODE (callee
))
1612 /* All the following functions read memory pointed to by
1613 their second argument. strcat/strncat additionally
1614 reads memory pointed to by the first argument. */
1615 case BUILT_IN_STRCAT
:
1616 case BUILT_IN_STRNCAT
:
1619 ao_ref_init_from_ptr_and_size (&dref
,
1620 gimple_call_arg (call
, 0),
1622 if (refs_may_alias_p_1 (&dref
, ref
, false))
1626 case BUILT_IN_STRCPY
:
1627 case BUILT_IN_STRNCPY
:
1628 case BUILT_IN_MEMCPY
:
1629 case BUILT_IN_MEMMOVE
:
1630 case BUILT_IN_MEMPCPY
:
1631 case BUILT_IN_STPCPY
:
1632 case BUILT_IN_STPNCPY
:
1633 case BUILT_IN_TM_MEMCPY
:
1634 case BUILT_IN_TM_MEMMOVE
:
1637 tree size
= NULL_TREE
;
1638 if (gimple_call_num_args (call
) == 3)
1639 size
= gimple_call_arg (call
, 2);
1640 ao_ref_init_from_ptr_and_size (&dref
,
1641 gimple_call_arg (call
, 1),
1643 return refs_may_alias_p_1 (&dref
, ref
, false);
1645 case BUILT_IN_STRCAT_CHK
:
1646 case BUILT_IN_STRNCAT_CHK
:
1649 ao_ref_init_from_ptr_and_size (&dref
,
1650 gimple_call_arg (call
, 0),
1652 if (refs_may_alias_p_1 (&dref
, ref
, false))
1656 case BUILT_IN_STRCPY_CHK
:
1657 case BUILT_IN_STRNCPY_CHK
:
1658 case BUILT_IN_MEMCPY_CHK
:
1659 case BUILT_IN_MEMMOVE_CHK
:
1660 case BUILT_IN_MEMPCPY_CHK
:
1661 case BUILT_IN_STPCPY_CHK
:
1662 case BUILT_IN_STPNCPY_CHK
:
1665 tree size
= NULL_TREE
;
1666 if (gimple_call_num_args (call
) == 4)
1667 size
= gimple_call_arg (call
, 2);
1668 ao_ref_init_from_ptr_and_size (&dref
,
1669 gimple_call_arg (call
, 1),
1671 return refs_may_alias_p_1 (&dref
, ref
, false);
1673 case BUILT_IN_BCOPY
:
1676 tree size
= gimple_call_arg (call
, 2);
1677 ao_ref_init_from_ptr_and_size (&dref
,
1678 gimple_call_arg (call
, 0),
1680 return refs_may_alias_p_1 (&dref
, ref
, false);
1683 /* The following functions read memory pointed to by their
1685 CASE_BUILT_IN_TM_LOAD (1):
1686 CASE_BUILT_IN_TM_LOAD (2):
1687 CASE_BUILT_IN_TM_LOAD (4):
1688 CASE_BUILT_IN_TM_LOAD (8):
1689 CASE_BUILT_IN_TM_LOAD (FLOAT
):
1690 CASE_BUILT_IN_TM_LOAD (DOUBLE
):
1691 CASE_BUILT_IN_TM_LOAD (LDOUBLE
):
1692 CASE_BUILT_IN_TM_LOAD (M64
):
1693 CASE_BUILT_IN_TM_LOAD (M128
):
1694 CASE_BUILT_IN_TM_LOAD (M256
):
1695 case BUILT_IN_TM_LOG
:
1696 case BUILT_IN_TM_LOG_1
:
1697 case BUILT_IN_TM_LOG_2
:
1698 case BUILT_IN_TM_LOG_4
:
1699 case BUILT_IN_TM_LOG_8
:
1700 case BUILT_IN_TM_LOG_FLOAT
:
1701 case BUILT_IN_TM_LOG_DOUBLE
:
1702 case BUILT_IN_TM_LOG_LDOUBLE
:
1703 case BUILT_IN_TM_LOG_M64
:
1704 case BUILT_IN_TM_LOG_M128
:
1705 case BUILT_IN_TM_LOG_M256
:
1706 return ptr_deref_may_alias_ref_p_1 (gimple_call_arg (call
, 0), ref
);
1708 /* These read memory pointed to by the first argument. */
1709 case BUILT_IN_STRDUP
:
1710 case BUILT_IN_STRNDUP
:
1711 case BUILT_IN_REALLOC
:
1714 tree size
= NULL_TREE
;
1715 if (gimple_call_num_args (call
) == 2)
1716 size
= gimple_call_arg (call
, 1);
1717 ao_ref_init_from_ptr_and_size (&dref
,
1718 gimple_call_arg (call
, 0),
1720 return refs_may_alias_p_1 (&dref
, ref
, false);
1722 /* These read memory pointed to by the first argument. */
1723 case BUILT_IN_INDEX
:
1724 case BUILT_IN_STRCHR
:
1725 case BUILT_IN_STRRCHR
:
1728 ao_ref_init_from_ptr_and_size (&dref
,
1729 gimple_call_arg (call
, 0),
1731 return refs_may_alias_p_1 (&dref
, ref
, false);
1733 /* These read memory pointed to by the first argument with size
1734 in the third argument. */
1735 case BUILT_IN_MEMCHR
:
1738 ao_ref_init_from_ptr_and_size (&dref
,
1739 gimple_call_arg (call
, 0),
1740 gimple_call_arg (call
, 2));
1741 return refs_may_alias_p_1 (&dref
, ref
, false);
1743 /* These read memory pointed to by the first and second arguments. */
1744 case BUILT_IN_STRSTR
:
1745 case BUILT_IN_STRPBRK
:
1748 ao_ref_init_from_ptr_and_size (&dref
,
1749 gimple_call_arg (call
, 0),
1751 if (refs_may_alias_p_1 (&dref
, ref
, false))
1753 ao_ref_init_from_ptr_and_size (&dref
,
1754 gimple_call_arg (call
, 1),
1756 return refs_may_alias_p_1 (&dref
, ref
, false);
1759 /* The following builtins do not read from memory. */
1761 case BUILT_IN_MALLOC
:
1762 case BUILT_IN_POSIX_MEMALIGN
:
1763 case BUILT_IN_ALIGNED_ALLOC
:
1764 case BUILT_IN_CALLOC
:
1765 CASE_BUILT_IN_ALLOCA
:
1766 case BUILT_IN_STACK_SAVE
:
1767 case BUILT_IN_STACK_RESTORE
:
1768 case BUILT_IN_MEMSET
:
1769 case BUILT_IN_TM_MEMSET
:
1770 case BUILT_IN_MEMSET_CHK
:
1771 case BUILT_IN_FREXP
:
1772 case BUILT_IN_FREXPF
:
1773 case BUILT_IN_FREXPL
:
1774 case BUILT_IN_GAMMA_R
:
1775 case BUILT_IN_GAMMAF_R
:
1776 case BUILT_IN_GAMMAL_R
:
1777 case BUILT_IN_LGAMMA_R
:
1778 case BUILT_IN_LGAMMAF_R
:
1779 case BUILT_IN_LGAMMAL_R
:
1781 case BUILT_IN_MODFF
:
1782 case BUILT_IN_MODFL
:
1783 case BUILT_IN_REMQUO
:
1784 case BUILT_IN_REMQUOF
:
1785 case BUILT_IN_REMQUOL
:
1786 case BUILT_IN_SINCOS
:
1787 case BUILT_IN_SINCOSF
:
1788 case BUILT_IN_SINCOSL
:
1789 case BUILT_IN_ASSUME_ALIGNED
:
1790 case BUILT_IN_VA_END
:
1792 /* __sync_* builtins and some OpenMP builtins act as threading
1794 #undef DEF_SYNC_BUILTIN
1795 #define DEF_SYNC_BUILTIN(ENUM, NAME, TYPE, ATTRS) case ENUM:
1796 #include "sync-builtins.def"
1797 #undef DEF_SYNC_BUILTIN
1798 case BUILT_IN_GOMP_ATOMIC_START
:
1799 case BUILT_IN_GOMP_ATOMIC_END
:
1800 case BUILT_IN_GOMP_BARRIER
:
1801 case BUILT_IN_GOMP_BARRIER_CANCEL
:
1802 case BUILT_IN_GOMP_TASKWAIT
:
1803 case BUILT_IN_GOMP_TASKGROUP_END
:
1804 case BUILT_IN_GOMP_CRITICAL_START
:
1805 case BUILT_IN_GOMP_CRITICAL_END
:
1806 case BUILT_IN_GOMP_CRITICAL_NAME_START
:
1807 case BUILT_IN_GOMP_CRITICAL_NAME_END
:
1808 case BUILT_IN_GOMP_LOOP_END
:
1809 case BUILT_IN_GOMP_LOOP_END_CANCEL
:
1810 case BUILT_IN_GOMP_ORDERED_START
:
1811 case BUILT_IN_GOMP_ORDERED_END
:
1812 case BUILT_IN_GOMP_SECTIONS_END
:
1813 case BUILT_IN_GOMP_SECTIONS_END_CANCEL
:
1814 case BUILT_IN_GOMP_SINGLE_COPY_START
:
1815 case BUILT_IN_GOMP_SINGLE_COPY_END
:
1819 /* Fallthru to general call handling. */;
1822 /* Check if base is a global static variable that is not read
1824 if (callee
!= NULL_TREE
&& VAR_P (base
) && TREE_STATIC (base
))
1826 struct cgraph_node
*node
= cgraph_node::get (callee
);
1829 /* FIXME: Callee can be an OMP builtin that does not have a call graph
1830 node yet. We should enforce that there are nodes for all decls in the
1831 IL and remove this check instead. */
1833 && (not_read
= ipa_reference_get_not_read_global (node
))
1834 && bitmap_bit_p (not_read
, ipa_reference_var_uid (base
)))
1838 /* Check if the base variable is call-used. */
1841 if (pt_solution_includes (gimple_call_use_set (call
), base
))
1844 else if ((TREE_CODE (base
) == MEM_REF
1845 || TREE_CODE (base
) == TARGET_MEM_REF
)
1846 && TREE_CODE (TREE_OPERAND (base
, 0)) == SSA_NAME
)
1848 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (TREE_OPERAND (base
, 0));
1852 if (pt_solutions_intersect (gimple_call_use_set (call
), &pi
->pt
))
1858 /* Inspect call arguments for passed-by-value aliases. */
1860 for (i
= 0; i
< gimple_call_num_args (call
); ++i
)
1862 tree op
= gimple_call_arg (call
, i
);
1863 int flags
= gimple_call_arg_flags (call
, i
);
1865 if (flags
& EAF_UNUSED
)
1868 if (TREE_CODE (op
) == WITH_SIZE_EXPR
)
1869 op
= TREE_OPERAND (op
, 0);
1871 if (TREE_CODE (op
) != SSA_NAME
1872 && !is_gimple_min_invariant (op
))
1875 ao_ref_init (&r
, op
);
1876 if (refs_may_alias_p_1 (&r
, ref
, tbaa_p
))
1885 ref_maybe_used_by_call_p (gcall
*call
, ao_ref
*ref
, bool tbaa_p
)
1888 res
= ref_maybe_used_by_call_p_1 (call
, ref
, tbaa_p
);
1890 ++alias_stats
.ref_maybe_used_by_call_p_may_alias
;
1892 ++alias_stats
.ref_maybe_used_by_call_p_no_alias
;
1897 /* If the statement STMT may use the memory reference REF return
1898 true, otherwise return false. */
1901 ref_maybe_used_by_stmt_p (gimple
*stmt
, ao_ref
*ref
, bool tbaa_p
)
1903 if (is_gimple_assign (stmt
))
1907 /* All memory assign statements are single. */
1908 if (!gimple_assign_single_p (stmt
))
1911 rhs
= gimple_assign_rhs1 (stmt
);
1912 if (is_gimple_reg (rhs
)
1913 || is_gimple_min_invariant (rhs
)
1914 || gimple_assign_rhs_code (stmt
) == CONSTRUCTOR
)
1917 return refs_may_alias_p (rhs
, ref
, tbaa_p
);
1919 else if (is_gimple_call (stmt
))
1920 return ref_maybe_used_by_call_p (as_a
<gcall
*> (stmt
), ref
, tbaa_p
);
1921 else if (greturn
*return_stmt
= dyn_cast
<greturn
*> (stmt
))
1923 tree retval
= gimple_return_retval (return_stmt
);
1925 && TREE_CODE (retval
) != SSA_NAME
1926 && !is_gimple_min_invariant (retval
)
1927 && refs_may_alias_p (retval
, ref
, tbaa_p
))
1929 /* If ref escapes the function then the return acts as a use. */
1930 tree base
= ao_ref_base (ref
);
1933 else if (DECL_P (base
))
1934 return is_global_var (base
);
1935 else if (TREE_CODE (base
) == MEM_REF
1936 || TREE_CODE (base
) == TARGET_MEM_REF
)
1937 return ptr_deref_may_alias_global_p (TREE_OPERAND (base
, 0));
1945 ref_maybe_used_by_stmt_p (gimple
*stmt
, tree ref
, bool tbaa_p
)
1948 ao_ref_init (&r
, ref
);
1949 return ref_maybe_used_by_stmt_p (stmt
, &r
, tbaa_p
);
1952 /* If the call in statement CALL may clobber the memory reference REF
1953 return true, otherwise return false. */
1956 call_may_clobber_ref_p_1 (gcall
*call
, ao_ref
*ref
)
1961 /* If the call is pure or const it cannot clobber anything. */
1962 if (gimple_call_flags (call
)
1963 & (ECF_PURE
|ECF_CONST
|ECF_LOOPING_CONST_OR_PURE
|ECF_NOVOPS
))
1965 if (gimple_call_internal_p (call
))
1966 switch (gimple_call_internal_fn (call
))
1968 /* Treat these internal calls like ECF_PURE for aliasing,
1969 they don't write to any memory the program should care about.
1970 They have important other side-effects, and read memory,
1971 so can't be ECF_NOVOPS. */
1972 case IFN_UBSAN_NULL
:
1973 case IFN_UBSAN_BOUNDS
:
1974 case IFN_UBSAN_VPTR
:
1975 case IFN_UBSAN_OBJECT_SIZE
:
1977 case IFN_ASAN_CHECK
:
1983 base
= ao_ref_base (ref
);
1987 if (TREE_CODE (base
) == SSA_NAME
1988 || CONSTANT_CLASS_P (base
))
1991 /* A call that is not without side-effects might involve volatile
1992 accesses and thus conflicts with all other volatile accesses. */
1993 if (ref
->volatile_p
)
1996 /* If the reference is based on a decl that is not aliased the call
1997 cannot possibly clobber it. */
1999 && !may_be_aliased (base
)
2000 /* But local non-readonly statics can be modified through recursion
2001 or the call may implement a threading barrier which we must
2002 treat as may-def. */
2003 && (TREE_READONLY (base
)
2004 || !is_global_var (base
)))
2007 /* If the reference is based on a pointer that points to memory
2008 that may not be written to then the call cannot possibly clobber it. */
2009 if ((TREE_CODE (base
) == MEM_REF
2010 || TREE_CODE (base
) == TARGET_MEM_REF
)
2011 && TREE_CODE (TREE_OPERAND (base
, 0)) == SSA_NAME
2012 && SSA_NAME_POINTS_TO_READONLY_MEMORY (TREE_OPERAND (base
, 0)))
2015 callee
= gimple_call_fndecl (call
);
2017 /* Handle those builtin functions explicitly that do not act as
2018 escape points. See tree-ssa-structalias.c:find_func_aliases
2019 for the list of builtins we might need to handle here. */
2020 if (callee
!= NULL_TREE
2021 && gimple_call_builtin_p (call
, BUILT_IN_NORMAL
))
2022 switch (DECL_FUNCTION_CODE (callee
))
2024 /* All the following functions clobber memory pointed to by
2025 their first argument. */
2026 case BUILT_IN_STRCPY
:
2027 case BUILT_IN_STRNCPY
:
2028 case BUILT_IN_MEMCPY
:
2029 case BUILT_IN_MEMMOVE
:
2030 case BUILT_IN_MEMPCPY
:
2031 case BUILT_IN_STPCPY
:
2032 case BUILT_IN_STPNCPY
:
2033 case BUILT_IN_STRCAT
:
2034 case BUILT_IN_STRNCAT
:
2035 case BUILT_IN_MEMSET
:
2036 case BUILT_IN_TM_MEMSET
:
2037 CASE_BUILT_IN_TM_STORE (1):
2038 CASE_BUILT_IN_TM_STORE (2):
2039 CASE_BUILT_IN_TM_STORE (4):
2040 CASE_BUILT_IN_TM_STORE (8):
2041 CASE_BUILT_IN_TM_STORE (FLOAT
):
2042 CASE_BUILT_IN_TM_STORE (DOUBLE
):
2043 CASE_BUILT_IN_TM_STORE (LDOUBLE
):
2044 CASE_BUILT_IN_TM_STORE (M64
):
2045 CASE_BUILT_IN_TM_STORE (M128
):
2046 CASE_BUILT_IN_TM_STORE (M256
):
2047 case BUILT_IN_TM_MEMCPY
:
2048 case BUILT_IN_TM_MEMMOVE
:
2051 tree size
= NULL_TREE
;
2052 /* Don't pass in size for strncat, as the maximum size
2053 is strlen (dest) + n + 1 instead of n, resp.
2054 n + 1 at dest + strlen (dest), but strlen (dest) isn't
2056 if (gimple_call_num_args (call
) == 3
2057 && DECL_FUNCTION_CODE (callee
) != BUILT_IN_STRNCAT
)
2058 size
= gimple_call_arg (call
, 2);
2059 ao_ref_init_from_ptr_and_size (&dref
,
2060 gimple_call_arg (call
, 0),
2062 return refs_may_alias_p_1 (&dref
, ref
, false);
2064 case BUILT_IN_STRCPY_CHK
:
2065 case BUILT_IN_STRNCPY_CHK
:
2066 case BUILT_IN_MEMCPY_CHK
:
2067 case BUILT_IN_MEMMOVE_CHK
:
2068 case BUILT_IN_MEMPCPY_CHK
:
2069 case BUILT_IN_STPCPY_CHK
:
2070 case BUILT_IN_STPNCPY_CHK
:
2071 case BUILT_IN_STRCAT_CHK
:
2072 case BUILT_IN_STRNCAT_CHK
:
2073 case BUILT_IN_MEMSET_CHK
:
2076 tree size
= NULL_TREE
;
2077 /* Don't pass in size for __strncat_chk, as the maximum size
2078 is strlen (dest) + n + 1 instead of n, resp.
2079 n + 1 at dest + strlen (dest), but strlen (dest) isn't
2081 if (gimple_call_num_args (call
) == 4
2082 && DECL_FUNCTION_CODE (callee
) != BUILT_IN_STRNCAT_CHK
)
2083 size
= gimple_call_arg (call
, 2);
2084 ao_ref_init_from_ptr_and_size (&dref
,
2085 gimple_call_arg (call
, 0),
2087 return refs_may_alias_p_1 (&dref
, ref
, false);
2089 case BUILT_IN_BCOPY
:
2092 tree size
= gimple_call_arg (call
, 2);
2093 ao_ref_init_from_ptr_and_size (&dref
,
2094 gimple_call_arg (call
, 1),
2096 return refs_may_alias_p_1 (&dref
, ref
, false);
2098 /* Allocating memory does not have any side-effects apart from
2099 being the definition point for the pointer. */
2100 case BUILT_IN_MALLOC
:
2101 case BUILT_IN_ALIGNED_ALLOC
:
2102 case BUILT_IN_CALLOC
:
2103 case BUILT_IN_STRDUP
:
2104 case BUILT_IN_STRNDUP
:
2105 /* Unix98 specifies that errno is set on allocation failure. */
2107 && targetm
.ref_may_alias_errno (ref
))
2110 case BUILT_IN_STACK_SAVE
:
2111 CASE_BUILT_IN_ALLOCA
:
2112 case BUILT_IN_ASSUME_ALIGNED
:
2114 /* But posix_memalign stores a pointer into the memory pointed to
2115 by its first argument. */
2116 case BUILT_IN_POSIX_MEMALIGN
:
2118 tree ptrptr
= gimple_call_arg (call
, 0);
2120 ao_ref_init_from_ptr_and_size (&dref
, ptrptr
,
2121 TYPE_SIZE_UNIT (ptr_type_node
));
2122 return (refs_may_alias_p_1 (&dref
, ref
, false)
2124 && targetm
.ref_may_alias_errno (ref
)));
2126 /* Freeing memory kills the pointed-to memory. More importantly
2127 the call has to serve as a barrier for moving loads and stores
2130 case BUILT_IN_VA_END
:
2132 tree ptr
= gimple_call_arg (call
, 0);
2133 return ptr_deref_may_alias_ref_p_1 (ptr
, ref
);
2135 /* Realloc serves both as allocation point and deallocation point. */
2136 case BUILT_IN_REALLOC
:
2138 tree ptr
= gimple_call_arg (call
, 0);
2139 /* Unix98 specifies that errno is set on allocation failure. */
2140 return ((flag_errno_math
2141 && targetm
.ref_may_alias_errno (ref
))
2142 || ptr_deref_may_alias_ref_p_1 (ptr
, ref
));
2144 case BUILT_IN_GAMMA_R
:
2145 case BUILT_IN_GAMMAF_R
:
2146 case BUILT_IN_GAMMAL_R
:
2147 case BUILT_IN_LGAMMA_R
:
2148 case BUILT_IN_LGAMMAF_R
:
2149 case BUILT_IN_LGAMMAL_R
:
2151 tree out
= gimple_call_arg (call
, 1);
2152 if (ptr_deref_may_alias_ref_p_1 (out
, ref
))
2154 if (flag_errno_math
)
2158 case BUILT_IN_FREXP
:
2159 case BUILT_IN_FREXPF
:
2160 case BUILT_IN_FREXPL
:
2162 case BUILT_IN_MODFF
:
2163 case BUILT_IN_MODFL
:
2165 tree out
= gimple_call_arg (call
, 1);
2166 return ptr_deref_may_alias_ref_p_1 (out
, ref
);
2168 case BUILT_IN_REMQUO
:
2169 case BUILT_IN_REMQUOF
:
2170 case BUILT_IN_REMQUOL
:
2172 tree out
= gimple_call_arg (call
, 2);
2173 if (ptr_deref_may_alias_ref_p_1 (out
, ref
))
2175 if (flag_errno_math
)
2179 case BUILT_IN_SINCOS
:
2180 case BUILT_IN_SINCOSF
:
2181 case BUILT_IN_SINCOSL
:
2183 tree sin
= gimple_call_arg (call
, 1);
2184 tree cos
= gimple_call_arg (call
, 2);
2185 return (ptr_deref_may_alias_ref_p_1 (sin
, ref
)
2186 || ptr_deref_may_alias_ref_p_1 (cos
, ref
));
2188 /* __sync_* builtins and some OpenMP builtins act as threading
2190 #undef DEF_SYNC_BUILTIN
2191 #define DEF_SYNC_BUILTIN(ENUM, NAME, TYPE, ATTRS) case ENUM:
2192 #include "sync-builtins.def"
2193 #undef DEF_SYNC_BUILTIN
2194 case BUILT_IN_GOMP_ATOMIC_START
:
2195 case BUILT_IN_GOMP_ATOMIC_END
:
2196 case BUILT_IN_GOMP_BARRIER
:
2197 case BUILT_IN_GOMP_BARRIER_CANCEL
:
2198 case BUILT_IN_GOMP_TASKWAIT
:
2199 case BUILT_IN_GOMP_TASKGROUP_END
:
2200 case BUILT_IN_GOMP_CRITICAL_START
:
2201 case BUILT_IN_GOMP_CRITICAL_END
:
2202 case BUILT_IN_GOMP_CRITICAL_NAME_START
:
2203 case BUILT_IN_GOMP_CRITICAL_NAME_END
:
2204 case BUILT_IN_GOMP_LOOP_END
:
2205 case BUILT_IN_GOMP_LOOP_END_CANCEL
:
2206 case BUILT_IN_GOMP_ORDERED_START
:
2207 case BUILT_IN_GOMP_ORDERED_END
:
2208 case BUILT_IN_GOMP_SECTIONS_END
:
2209 case BUILT_IN_GOMP_SECTIONS_END_CANCEL
:
2210 case BUILT_IN_GOMP_SINGLE_COPY_START
:
2211 case BUILT_IN_GOMP_SINGLE_COPY_END
:
2214 /* Fallthru to general call handling. */;
2217 /* Check if base is a global static variable that is not written
2219 if (callee
!= NULL_TREE
&& VAR_P (base
) && 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
, bool tbaa_p
)
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
, tbaa_p
))
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
, tbaa_p
);
2295 else if (gimple_code (stmt
) == GIMPLE_ASM
)
2302 stmt_may_clobber_ref_p (gimple
*stmt
, tree ref
, bool tbaa_p
)
2305 ao_ref_init (&r
, ref
);
2306 return stmt_may_clobber_ref_p_1 (stmt
, &r
, tbaa_p
);
2309 /* Return true if store1 and store2 described by corresponding tuples
2310 <BASE, OFFSET, SIZE, MAX_SIZE> have the same size and store to the same
2314 same_addr_size_stores_p (tree base1
, poly_int64 offset1
, poly_int64 size1
,
2315 poly_int64 max_size1
,
2316 tree base2
, poly_int64 offset2
, poly_int64 size2
,
2317 poly_int64 max_size2
)
2319 /* Offsets need to be 0. */
2320 if (maybe_ne (offset1
, 0)
2321 || maybe_ne (offset2
, 0))
2324 bool base1_obj_p
= SSA_VAR_P (base1
);
2325 bool base2_obj_p
= SSA_VAR_P (base2
);
2327 /* We need one object. */
2328 if (base1_obj_p
== base2_obj_p
)
2330 tree obj
= base1_obj_p
? base1
: base2
;
2332 /* And we need one MEM_REF. */
2333 bool base1_memref_p
= TREE_CODE (base1
) == MEM_REF
;
2334 bool base2_memref_p
= TREE_CODE (base2
) == MEM_REF
;
2335 if (base1_memref_p
== base2_memref_p
)
2337 tree memref
= base1_memref_p
? base1
: base2
;
2339 /* Sizes need to be valid. */
2340 if (!known_size_p (max_size1
)
2341 || !known_size_p (max_size2
)
2342 || !known_size_p (size1
)
2343 || !known_size_p (size2
))
2346 /* Max_size needs to match size. */
2347 if (maybe_ne (max_size1
, size1
)
2348 || maybe_ne (max_size2
, size2
))
2351 /* Sizes need to match. */
2352 if (maybe_ne (size1
, size2
))
2356 /* Check that memref is a store to pointer with singleton points-to info. */
2357 if (!integer_zerop (TREE_OPERAND (memref
, 1)))
2359 tree ptr
= TREE_OPERAND (memref
, 0);
2360 if (TREE_CODE (ptr
) != SSA_NAME
)
2362 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (ptr
);
2363 unsigned int pt_uid
;
2365 || !pt_solution_singleton_or_null_p (&pi
->pt
, &pt_uid
))
2368 /* Be conservative with non-call exceptions when the address might
2370 if (cfun
->can_throw_non_call_exceptions
&& pi
->pt
.null
)
2373 /* Check that ptr points relative to obj. */
2374 unsigned int obj_uid
= DECL_PT_UID (obj
);
2375 if (obj_uid
!= pt_uid
)
2378 /* Check that the object size is the same as the store size. That ensures us
2379 that ptr points to the start of obj. */
2380 return (DECL_SIZE (obj
)
2381 && poly_int_tree_p (DECL_SIZE (obj
))
2382 && known_eq (wi::to_poly_offset (DECL_SIZE (obj
)), size1
));
2385 /* If STMT kills the memory reference REF return true, otherwise
2389 stmt_kills_ref_p (gimple
*stmt
, ao_ref
*ref
)
2391 if (!ao_ref_base (ref
))
2394 if (gimple_has_lhs (stmt
)
2395 && TREE_CODE (gimple_get_lhs (stmt
)) != SSA_NAME
2396 /* The assignment is not necessarily carried out if it can throw
2397 and we can catch it in the current function where we could inspect
2399 ??? We only need to care about the RHS throwing. For aggregate
2400 assignments or similar calls and non-call exceptions the LHS
2401 might throw as well. */
2402 && !stmt_can_throw_internal (cfun
, stmt
))
2404 tree lhs
= gimple_get_lhs (stmt
);
2405 /* If LHS is literally a base of the access we are done. */
2408 tree base
= ref
->ref
;
2409 tree innermost_dropped_array_ref
= NULL_TREE
;
2410 if (handled_component_p (base
))
2412 tree saved_lhs0
= NULL_TREE
;
2413 if (handled_component_p (lhs
))
2415 saved_lhs0
= TREE_OPERAND (lhs
, 0);
2416 TREE_OPERAND (lhs
, 0) = integer_zero_node
;
2420 /* Just compare the outermost handled component, if
2421 they are equal we have found a possible common
2423 tree saved_base0
= TREE_OPERAND (base
, 0);
2424 TREE_OPERAND (base
, 0) = integer_zero_node
;
2425 bool res
= operand_equal_p (lhs
, base
, 0);
2426 TREE_OPERAND (base
, 0) = saved_base0
;
2429 /* Remember if we drop an array-ref that we need to
2430 double-check not being at struct end. */
2431 if (TREE_CODE (base
) == ARRAY_REF
2432 || TREE_CODE (base
) == ARRAY_RANGE_REF
)
2433 innermost_dropped_array_ref
= base
;
2434 /* Otherwise drop handled components of the access. */
2437 while (handled_component_p (base
));
2439 TREE_OPERAND (lhs
, 0) = saved_lhs0
;
2441 /* Finally check if the lhs has the same address and size as the
2442 base candidate of the access. Watch out if we have dropped
2443 an array-ref that was at struct end, this means ref->ref may
2444 be outside of the TYPE_SIZE of its base. */
2445 if ((! innermost_dropped_array_ref
2446 || ! array_at_struct_end_p (innermost_dropped_array_ref
))
2448 || (((TYPE_SIZE (TREE_TYPE (lhs
))
2449 == TYPE_SIZE (TREE_TYPE (base
)))
2450 || (TYPE_SIZE (TREE_TYPE (lhs
))
2451 && TYPE_SIZE (TREE_TYPE (base
))
2452 && operand_equal_p (TYPE_SIZE (TREE_TYPE (lhs
)),
2453 TYPE_SIZE (TREE_TYPE (base
)),
2455 && operand_equal_p (lhs
, base
,
2457 | OEP_MATCH_SIDE_EFFECTS
))))
2461 /* Now look for non-literal equal bases with the restriction of
2462 handling constant offset and size. */
2463 /* For a must-alias check we need to be able to constrain
2464 the access properly. */
2465 if (!ref
->max_size_known_p ())
2467 poly_int64 size
, offset
, max_size
, ref_offset
= ref
->offset
;
2469 tree base
= get_ref_base_and_extent (lhs
, &offset
, &size
, &max_size
,
2471 /* We can get MEM[symbol: sZ, index: D.8862_1] here,
2472 so base == ref->base does not always hold. */
2473 if (base
!= ref
->base
)
2475 /* Try using points-to info. */
2476 if (same_addr_size_stores_p (base
, offset
, size
, max_size
, ref
->base
,
2477 ref
->offset
, ref
->size
, ref
->max_size
))
2480 /* If both base and ref->base are MEM_REFs, only compare the
2481 first operand, and if the second operand isn't equal constant,
2482 try to add the offsets into offset and ref_offset. */
2483 if (TREE_CODE (base
) == MEM_REF
&& TREE_CODE (ref
->base
) == MEM_REF
2484 && TREE_OPERAND (base
, 0) == TREE_OPERAND (ref
->base
, 0))
2486 if (!tree_int_cst_equal (TREE_OPERAND (base
, 1),
2487 TREE_OPERAND (ref
->base
, 1)))
2489 poly_offset_int off1
= mem_ref_offset (base
);
2490 off1
<<= LOG2_BITS_PER_UNIT
;
2492 poly_offset_int off2
= mem_ref_offset (ref
->base
);
2493 off2
<<= LOG2_BITS_PER_UNIT
;
2495 if (!off1
.to_shwi (&offset
) || !off2
.to_shwi (&ref_offset
))
2502 /* For a must-alias check we need to be able to constrain
2503 the access properly. */
2504 if (known_eq (size
, max_size
)
2505 && known_subrange_p (ref_offset
, ref
->max_size
, offset
, size
))
2509 if (is_gimple_call (stmt
))
2511 tree callee
= gimple_call_fndecl (stmt
);
2512 if (callee
!= NULL_TREE
2513 && gimple_call_builtin_p (stmt
, BUILT_IN_NORMAL
))
2514 switch (DECL_FUNCTION_CODE (callee
))
2518 tree ptr
= gimple_call_arg (stmt
, 0);
2519 tree base
= ao_ref_base (ref
);
2520 if (base
&& TREE_CODE (base
) == MEM_REF
2521 && TREE_OPERAND (base
, 0) == ptr
)
2526 case BUILT_IN_MEMCPY
:
2527 case BUILT_IN_MEMPCPY
:
2528 case BUILT_IN_MEMMOVE
:
2529 case BUILT_IN_MEMSET
:
2530 case BUILT_IN_MEMCPY_CHK
:
2531 case BUILT_IN_MEMPCPY_CHK
:
2532 case BUILT_IN_MEMMOVE_CHK
:
2533 case BUILT_IN_MEMSET_CHK
:
2534 case BUILT_IN_STRNCPY
:
2535 case BUILT_IN_STPNCPY
:
2537 /* For a must-alias check we need to be able to constrain
2538 the access properly. */
2539 if (!ref
->max_size_known_p ())
2541 tree dest
= gimple_call_arg (stmt
, 0);
2542 tree len
= gimple_call_arg (stmt
, 2);
2543 if (!poly_int_tree_p (len
))
2545 tree rbase
= ref
->base
;
2546 poly_offset_int roffset
= ref
->offset
;
2548 ao_ref_init_from_ptr_and_size (&dref
, dest
, len
);
2549 tree base
= ao_ref_base (&dref
);
2550 poly_offset_int offset
= dref
.offset
;
2551 if (!base
|| !known_size_p (dref
.size
))
2553 if (TREE_CODE (base
) == MEM_REF
)
2555 if (TREE_CODE (rbase
) != MEM_REF
)
2557 // Compare pointers.
2558 offset
+= mem_ref_offset (base
) << LOG2_BITS_PER_UNIT
;
2559 roffset
+= mem_ref_offset (rbase
) << LOG2_BITS_PER_UNIT
;
2560 base
= TREE_OPERAND (base
, 0);
2561 rbase
= TREE_OPERAND (rbase
, 0);
2564 && known_subrange_p (roffset
, ref
->max_size
, offset
,
2565 wi::to_poly_offset (len
)
2566 << LOG2_BITS_PER_UNIT
))
2571 case BUILT_IN_VA_END
:
2573 tree ptr
= gimple_call_arg (stmt
, 0);
2574 if (TREE_CODE (ptr
) == ADDR_EXPR
)
2576 tree base
= ao_ref_base (ref
);
2577 if (TREE_OPERAND (ptr
, 0) == base
)
2590 stmt_kills_ref_p (gimple
*stmt
, tree ref
)
2593 ao_ref_init (&r
, ref
);
2594 return stmt_kills_ref_p (stmt
, &r
);
2598 /* Walk the virtual use-def chain of VUSE until hitting the virtual operand
2599 TARGET or a statement clobbering the memory reference REF in which
2600 case false is returned. The walk starts with VUSE, one argument of PHI. */
2603 maybe_skip_until (gimple
*phi
, tree
&target
, basic_block target_bb
,
2604 ao_ref
*ref
, tree vuse
, unsigned int &limit
, bitmap
*visited
,
2605 bool abort_on_visited
,
2606 void *(*translate
)(ao_ref
*, tree
, void *, bool *),
2609 basic_block bb
= gimple_bb (phi
);
2612 *visited
= BITMAP_ALLOC (NULL
);
2614 bitmap_set_bit (*visited
, SSA_NAME_VERSION (PHI_RESULT (phi
)));
2616 /* Walk until we hit the target. */
2617 while (vuse
!= target
)
2619 gimple
*def_stmt
= SSA_NAME_DEF_STMT (vuse
);
2620 /* If we are searching for the target VUSE by walking up to
2621 TARGET_BB dominating the original PHI we are finished once
2622 we reach a default def or a definition in a block dominating
2623 that block. Update TARGET and return. */
2625 && (gimple_nop_p (def_stmt
)
2626 || dominated_by_p (CDI_DOMINATORS
,
2627 target_bb
, gimple_bb (def_stmt
))))
2633 /* Recurse for PHI nodes. */
2634 if (gimple_code (def_stmt
) == GIMPLE_PHI
)
2636 /* An already visited PHI node ends the walk successfully. */
2637 if (bitmap_bit_p (*visited
, SSA_NAME_VERSION (PHI_RESULT (def_stmt
))))
2638 return !abort_on_visited
;
2639 vuse
= get_continuation_for_phi (def_stmt
, ref
, limit
,
2640 visited
, abort_on_visited
,
2646 else if (gimple_nop_p (def_stmt
))
2650 /* A clobbering statement or the end of the IL ends it failing. */
2651 if ((int)limit
<= 0)
2654 if (stmt_may_clobber_ref_p_1 (def_stmt
, ref
))
2656 bool disambiguate_only
= true;
2658 && (*translate
) (ref
, vuse
, data
, &disambiguate_only
) == NULL
)
2664 /* If we reach a new basic-block see if we already skipped it
2665 in a previous walk that ended successfully. */
2666 if (gimple_bb (def_stmt
) != bb
)
2668 if (!bitmap_set_bit (*visited
, SSA_NAME_VERSION (vuse
)))
2669 return !abort_on_visited
;
2670 bb
= gimple_bb (def_stmt
);
2672 vuse
= gimple_vuse (def_stmt
);
2678 /* Starting from a PHI node for the virtual operand of the memory reference
2679 REF find a continuation virtual operand that allows to continue walking
2680 statements dominating PHI skipping only statements that cannot possibly
2681 clobber REF. Decrements LIMIT for each alias disambiguation done
2682 and aborts the walk, returning NULL_TREE if it reaches zero.
2683 Returns NULL_TREE if no suitable virtual operand can be found. */
2686 get_continuation_for_phi (gimple
*phi
, ao_ref
*ref
,
2687 unsigned int &limit
, bitmap
*visited
,
2688 bool abort_on_visited
,
2689 void *(*translate
)(ao_ref
*, tree
, void *, bool *),
2692 unsigned nargs
= gimple_phi_num_args (phi
);
2694 /* Through a single-argument PHI we can simply look through. */
2696 return PHI_ARG_DEF (phi
, 0);
2698 /* For two or more arguments try to pairwise skip non-aliasing code
2699 until we hit the phi argument definition that dominates the other one. */
2700 basic_block phi_bb
= gimple_bb (phi
);
2704 /* Find a candidate for the virtual operand which definition
2705 dominates those of all others. */
2706 /* First look if any of the args themselves satisfy this. */
2707 for (i
= 0; i
< nargs
; ++i
)
2709 arg0
= PHI_ARG_DEF (phi
, i
);
2710 if (SSA_NAME_IS_DEFAULT_DEF (arg0
))
2712 basic_block def_bb
= gimple_bb (SSA_NAME_DEF_STMT (arg0
));
2713 if (def_bb
!= phi_bb
2714 && dominated_by_p (CDI_DOMINATORS
, phi_bb
, def_bb
))
2718 /* If not, look if we can reach such candidate by walking defs
2719 until we hit the immediate dominator. maybe_skip_until will
2721 basic_block dom
= get_immediate_dominator (CDI_DOMINATORS
, phi_bb
);
2723 /* Then check against the (to be) found candidate. */
2724 for (i
= 0; i
< nargs
; ++i
)
2726 arg1
= PHI_ARG_DEF (phi
, i
);
2729 else if (! maybe_skip_until (phi
, arg0
, dom
, ref
, arg1
, limit
, visited
,
2731 /* Do not translate when walking over
2735 gimple_bb (SSA_NAME_DEF_STMT (arg1
)),
2737 ? NULL
: translate
, data
))
2744 /* Based on the memory reference REF and its virtual use VUSE call
2745 WALKER for each virtual use that is equivalent to VUSE, including VUSE
2746 itself. That is, for each virtual use for which its defining statement
2747 does not clobber REF.
2749 WALKER is called with REF, the current virtual use and DATA. If
2750 WALKER returns non-NULL the walk stops and its result is returned.
2751 At the end of a non-successful walk NULL is returned.
2753 TRANSLATE if non-NULL is called with a pointer to REF, the virtual
2754 use which definition is a statement that may clobber REF and DATA.
2755 If TRANSLATE returns (void *)-1 the walk stops and NULL is returned.
2756 If TRANSLATE returns non-NULL the walk stops and its result is returned.
2757 If TRANSLATE returns NULL the walk continues and TRANSLATE is supposed
2758 to adjust REF and *DATA to make that valid.
2760 VALUEIZE if non-NULL is called with the next VUSE that is considered
2761 and return value is substituted for that. This can be used to
2762 implement optimistic value-numbering for example. Note that the
2763 VUSE argument is assumed to be valueized already.
2765 LIMIT specifies the number of alias queries we are allowed to do,
2766 the walk stops when it reaches zero and NULL is returned. LIMIT
2767 is decremented by the number of alias queries (plus adjustments
2768 done by the callbacks) upon return.
2770 TODO: Cache the vector of equivalent vuses per ref, vuse pair. */
2773 walk_non_aliased_vuses (ao_ref
*ref
, tree vuse
,
2774 void *(*walker
)(ao_ref
*, tree
, void *),
2775 void *(*translate
)(ao_ref
*, tree
, void *, bool *),
2776 tree (*valueize
)(tree
),
2777 unsigned &limit
, void *data
)
2779 bitmap visited
= NULL
;
2781 bool translated
= false;
2783 timevar_push (TV_ALIAS_STMT_WALK
);
2789 /* ??? Do we want to account this to TV_ALIAS_STMT_WALK? */
2790 res
= (*walker
) (ref
, vuse
, data
);
2792 if (res
== (void *)-1)
2797 /* Lookup succeeded. */
2798 else if (res
!= NULL
)
2803 vuse
= valueize (vuse
);
2810 def_stmt
= SSA_NAME_DEF_STMT (vuse
);
2811 if (gimple_nop_p (def_stmt
))
2813 else if (gimple_code (def_stmt
) == GIMPLE_PHI
)
2814 vuse
= get_continuation_for_phi (def_stmt
, ref
, limit
,
2815 &visited
, translated
, translate
, data
);
2818 if ((int)limit
<= 0)
2823 if (stmt_may_clobber_ref_p_1 (def_stmt
, ref
))
2827 bool disambiguate_only
= false;
2828 res
= (*translate
) (ref
, vuse
, data
, &disambiguate_only
);
2829 /* Failed lookup and translation. */
2830 if (res
== (void *)-1)
2835 /* Lookup succeeded. */
2836 else if (res
!= NULL
)
2838 /* Translation succeeded, continue walking. */
2839 translated
= translated
|| !disambiguate_only
;
2841 vuse
= gimple_vuse (def_stmt
);
2847 BITMAP_FREE (visited
);
2849 timevar_pop (TV_ALIAS_STMT_WALK
);
2855 /* Based on the memory reference REF call WALKER for each vdef which
2856 defining statement may clobber REF, starting with VDEF. If REF
2857 is NULL_TREE, each defining statement is visited.
2859 WALKER is called with REF, the current vdef and DATA. If WALKER
2860 returns true the walk is stopped, otherwise it continues.
2862 If function entry is reached, FUNCTION_ENTRY_REACHED is set to true.
2863 The pointer may be NULL and then we do not track this information.
2865 At PHI nodes walk_aliased_vdefs forks into one walk for reach
2866 PHI argument (but only one walk continues on merge points), the
2867 return value is true if any of the walks was successful.
2869 The function returns the number of statements walked or -1 if
2870 LIMIT stmts were walked and the walk was aborted at this point.
2871 If LIMIT is zero the walk is not aborted. */
2874 walk_aliased_vdefs_1 (ao_ref
*ref
, tree vdef
,
2875 bool (*walker
)(ao_ref
*, tree
, void *), void *data
,
2876 bitmap
*visited
, unsigned int cnt
,
2877 bool *function_entry_reached
, unsigned limit
)
2881 gimple
*def_stmt
= SSA_NAME_DEF_STMT (vdef
);
2884 && !bitmap_set_bit (*visited
, SSA_NAME_VERSION (vdef
)))
2887 if (gimple_nop_p (def_stmt
))
2889 if (function_entry_reached
)
2890 *function_entry_reached
= true;
2893 else if (gimple_code (def_stmt
) == GIMPLE_PHI
)
2897 *visited
= BITMAP_ALLOC (NULL
);
2898 for (i
= 0; i
< gimple_phi_num_args (def_stmt
); ++i
)
2900 int res
= walk_aliased_vdefs_1 (ref
,
2901 gimple_phi_arg_def (def_stmt
, i
),
2902 walker
, data
, visited
, cnt
,
2903 function_entry_reached
, limit
);
2911 /* ??? Do we want to account this to TV_ALIAS_STMT_WALK? */
2916 || stmt_may_clobber_ref_p_1 (def_stmt
, ref
))
2917 && (*walker
) (ref
, vdef
, data
))
2920 vdef
= gimple_vuse (def_stmt
);
2926 walk_aliased_vdefs (ao_ref
*ref
, tree vdef
,
2927 bool (*walker
)(ao_ref
*, tree
, void *), void *data
,
2929 bool *function_entry_reached
, unsigned int limit
)
2931 bitmap local_visited
= NULL
;
2934 timevar_push (TV_ALIAS_STMT_WALK
);
2936 if (function_entry_reached
)
2937 *function_entry_reached
= false;
2939 ret
= walk_aliased_vdefs_1 (ref
, vdef
, walker
, data
,
2940 visited
? visited
: &local_visited
, 0,
2941 function_entry_reached
, limit
);
2943 BITMAP_FREE (local_visited
);
2945 timevar_pop (TV_ALIAS_STMT_WALK
);