1 /* Alias analysis for trees.
2 Copyright (C) 2004-2017 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 can not be pointed to. */
206 if (!may_be_aliased (decl
))
209 /* If we do not have useful points-to information for this pointer
210 we cannot disambiguate anything else. */
211 pi
= SSA_NAME_PTR_INFO (ptr
);
215 return pt_solution_includes (&pi
->pt
, decl
);
218 /* Return true if dereferenced PTR1 and PTR2 may alias.
219 The caller is responsible for applying TBAA to see if accesses
220 through PTR1 and PTR2 may conflict at all. */
223 ptr_derefs_may_alias_p (tree ptr1
, tree ptr2
)
225 struct ptr_info_def
*pi1
, *pi2
;
227 /* Conversions are irrelevant for points-to information and
228 data-dependence analysis can feed us those. */
232 /* Disregard pointer offsetting. */
233 if (TREE_CODE (ptr1
) == POINTER_PLUS_EXPR
)
237 ptr1
= TREE_OPERAND (ptr1
, 0);
239 while (TREE_CODE (ptr1
) == POINTER_PLUS_EXPR
);
240 return ptr_derefs_may_alias_p (ptr1
, ptr2
);
242 if (TREE_CODE (ptr2
) == POINTER_PLUS_EXPR
)
246 ptr2
= TREE_OPERAND (ptr2
, 0);
248 while (TREE_CODE (ptr2
) == POINTER_PLUS_EXPR
);
249 return ptr_derefs_may_alias_p (ptr1
, ptr2
);
252 /* ADDR_EXPR pointers either just offset another pointer or directly
253 specify the pointed-to set. */
254 if (TREE_CODE (ptr1
) == ADDR_EXPR
)
256 tree base
= get_base_address (TREE_OPERAND (ptr1
, 0));
258 && (TREE_CODE (base
) == MEM_REF
259 || TREE_CODE (base
) == TARGET_MEM_REF
))
260 return ptr_derefs_may_alias_p (TREE_OPERAND (base
, 0), ptr2
);
263 return ptr_deref_may_alias_decl_p (ptr2
, base
);
267 if (TREE_CODE (ptr2
) == ADDR_EXPR
)
269 tree base
= get_base_address (TREE_OPERAND (ptr2
, 0));
271 && (TREE_CODE (base
) == MEM_REF
272 || TREE_CODE (base
) == TARGET_MEM_REF
))
273 return ptr_derefs_may_alias_p (ptr1
, TREE_OPERAND (base
, 0));
276 return ptr_deref_may_alias_decl_p (ptr1
, base
);
281 /* From here we require SSA name pointers. Anything else aliases. */
282 if (TREE_CODE (ptr1
) != SSA_NAME
283 || TREE_CODE (ptr2
) != SSA_NAME
284 || !POINTER_TYPE_P (TREE_TYPE (ptr1
))
285 || !POINTER_TYPE_P (TREE_TYPE (ptr2
)))
288 /* We may end up with two empty points-to solutions for two same pointers.
289 In this case we still want to say both pointers alias, so shortcut
294 /* If we do not have useful points-to information for either pointer
295 we cannot disambiguate anything else. */
296 pi1
= SSA_NAME_PTR_INFO (ptr1
);
297 pi2
= SSA_NAME_PTR_INFO (ptr2
);
301 /* ??? This does not use TBAA to prune decls from the intersection
302 that not both pointers may access. */
303 return pt_solutions_intersect (&pi1
->pt
, &pi2
->pt
);
306 /* Return true if dereferencing PTR may alias *REF.
307 The caller is responsible for applying TBAA to see if PTR
308 may access *REF at all. */
311 ptr_deref_may_alias_ref_p_1 (tree ptr
, ao_ref
*ref
)
313 tree base
= ao_ref_base (ref
);
315 if (TREE_CODE (base
) == MEM_REF
316 || TREE_CODE (base
) == TARGET_MEM_REF
)
317 return ptr_derefs_may_alias_p (ptr
, TREE_OPERAND (base
, 0));
318 else if (DECL_P (base
))
319 return ptr_deref_may_alias_decl_p (ptr
, base
);
324 /* Returns true if PTR1 and PTR2 compare unequal because of points-to. */
327 ptrs_compare_unequal (tree ptr1
, tree ptr2
)
329 /* First resolve the pointers down to a SSA name pointer base or
330 a VAR_DECL, PARM_DECL or RESULT_DECL. This explicitely does
331 not yet try to handle LABEL_DECLs, FUNCTION_DECLs, CONST_DECLs
332 or STRING_CSTs which needs points-to adjustments to track them
333 in the points-to sets. */
334 tree obj1
= NULL_TREE
;
335 tree obj2
= NULL_TREE
;
336 if (TREE_CODE (ptr1
) == ADDR_EXPR
)
338 tree tem
= get_base_address (TREE_OPERAND (ptr1
, 0));
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 HOST_WIDE_INT 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 && TREE_CODE (gimple_assign_rhs2 (stmt
)) == INTEGER_CST
)
694 ptr
= gimple_assign_rhs1 (stmt
);
695 extra_offset
= BITS_PER_UNIT
696 * int_cst_value (gimple_assign_rhs2 (stmt
));
700 if (TREE_CODE (ptr
) == ADDR_EXPR
)
702 ref
->base
= get_addr_base_and_unit_offset (TREE_OPERAND (ptr
, 0), &t
);
704 ref
->offset
= BITS_PER_UNIT
* t
;
709 ref
->base
= get_base_address (TREE_OPERAND (ptr
, 0));
714 ref
->base
= build2 (MEM_REF
, char_type_node
,
715 ptr
, null_pointer_node
);
718 ref
->offset
+= extra_offset
;
720 && tree_fits_shwi_p (size
)
721 && (size_hwi
= tree_to_shwi (size
)) <= 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 HOST_WIDE_INT offset1
, HOST_WIDE_INT max_size1
,
784 alias_set_type ref2_alias_set
,
785 alias_set_type base2_alias_set
,
786 HOST_WIDE_INT offset2
, HOST_WIDE_INT 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 HOST_WIDE_INT 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_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 HOST_WIDE_INT 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_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 HOST_WIDE_INT offset1
, HOST_WIDE_INT max_size1
,
1094 tree ref2
, tree base2
,
1095 HOST_WIDE_INT offset2
, HOST_WIDE_INT max_size2
)
1097 gcc_checking_assert (DECL_P (base1
) && DECL_P (base2
));
1099 int cmp
= compare_base_decls (base1
, base2
);
1101 /* If both references are based on different variables, they cannot alias. */
1105 /* If both references are based on the same variable, they cannot alias if
1106 the accesses do not overlap. */
1108 && !ranges_overlap_p (offset1
, max_size1
, offset2
, max_size2
))
1111 /* For components with variable position, the above test isn't sufficient,
1112 so we disambiguate component references manually. */
1114 && handled_component_p (ref1
) && handled_component_p (ref2
)
1115 && nonoverlapping_component_refs_of_decl_p (ref1
, ref2
))
1121 /* Return true if an indirect reference based on *PTR1 constrained
1122 to [OFFSET1, OFFSET1 + MAX_SIZE1) may alias a variable based on BASE2
1123 constrained to [OFFSET2, OFFSET2 + MAX_SIZE2). *PTR1 and BASE2 have
1124 the alias sets BASE1_ALIAS_SET and BASE2_ALIAS_SET which can be -1
1125 in which case they are computed on-demand. REF1 and REF2
1126 if non-NULL are the complete memory reference trees. */
1129 indirect_ref_may_alias_decl_p (tree ref1 ATTRIBUTE_UNUSED
, tree base1
,
1130 HOST_WIDE_INT offset1
,
1131 HOST_WIDE_INT max_size1 ATTRIBUTE_UNUSED
,
1132 alias_set_type ref1_alias_set
,
1133 alias_set_type base1_alias_set
,
1134 tree ref2 ATTRIBUTE_UNUSED
, tree base2
,
1135 HOST_WIDE_INT offset2
, HOST_WIDE_INT max_size2
,
1136 alias_set_type ref2_alias_set
,
1137 alias_set_type base2_alias_set
, bool tbaa_p
)
1140 tree ptrtype1
, dbase2
;
1141 HOST_WIDE_INT offset1p
= offset1
, offset2p
= offset2
;
1142 HOST_WIDE_INT doffset1
, doffset2
;
1144 gcc_checking_assert ((TREE_CODE (base1
) == MEM_REF
1145 || TREE_CODE (base1
) == TARGET_MEM_REF
)
1148 ptr1
= TREE_OPERAND (base1
, 0);
1150 /* The offset embedded in MEM_REFs can be negative. Bias them
1151 so that the resulting offset adjustment is positive. */
1152 offset_int moff
= mem_ref_offset (base1
);
1153 moff
<<= LOG2_BITS_PER_UNIT
;
1154 if (wi::neg_p (moff
))
1155 offset2p
+= (-moff
).to_short_addr ();
1157 offset1p
+= moff
.to_short_addr ();
1159 /* If only one reference is based on a variable, they cannot alias if
1160 the pointer access is beyond the extent of the variable access.
1161 (the pointer base cannot validly point to an offset less than zero
1163 ??? IVOPTs creates bases that do not honor this restriction,
1164 so do not apply this optimization for TARGET_MEM_REFs. */
1165 if (TREE_CODE (base1
) != TARGET_MEM_REF
1166 && !ranges_overlap_p (MAX (0, offset1p
), -1, offset2p
, max_size2
))
1168 /* They also cannot alias if the pointer may not point to the decl. */
1169 if (!ptr_deref_may_alias_decl_p (ptr1
, base2
))
1172 /* Disambiguations that rely on strict aliasing rules follow. */
1173 if (!flag_strict_aliasing
|| !tbaa_p
)
1176 ptrtype1
= TREE_TYPE (TREE_OPERAND (base1
, 1));
1178 /* If the alias set for a pointer access is zero all bets are off. */
1179 if (base1_alias_set
== 0)
1182 /* When we are trying to disambiguate an access with a pointer dereference
1183 as base versus one with a decl as base we can use both the size
1184 of the decl and its dynamic type for extra disambiguation.
1185 ??? We do not know anything about the dynamic type of the decl
1186 other than that its alias-set contains base2_alias_set as a subset
1187 which does not help us here. */
1188 /* As we know nothing useful about the dynamic type of the decl just
1189 use the usual conflict check rather than a subset test.
1190 ??? We could introduce -fvery-strict-aliasing when the language
1191 does not allow decls to have a dynamic type that differs from their
1192 static type. Then we can check
1193 !alias_set_subset_of (base1_alias_set, base2_alias_set) instead. */
1194 if (base1_alias_set
!= base2_alias_set
1195 && !alias_sets_conflict_p (base1_alias_set
, base2_alias_set
))
1197 /* If the size of the access relevant for TBAA through the pointer
1198 is bigger than the size of the decl we can't possibly access the
1199 decl via that pointer. */
1200 if (DECL_SIZE (base2
) && COMPLETE_TYPE_P (TREE_TYPE (ptrtype1
))
1201 && TREE_CODE (DECL_SIZE (base2
)) == INTEGER_CST
1202 && TREE_CODE (TYPE_SIZE (TREE_TYPE (ptrtype1
))) == INTEGER_CST
1203 /* ??? This in turn may run afoul when a decl of type T which is
1204 a member of union type U is accessed through a pointer to
1205 type U and sizeof T is smaller than sizeof U. */
1206 && TREE_CODE (TREE_TYPE (ptrtype1
)) != UNION_TYPE
1207 && TREE_CODE (TREE_TYPE (ptrtype1
)) != QUAL_UNION_TYPE
1208 && tree_int_cst_lt (DECL_SIZE (base2
), TYPE_SIZE (TREE_TYPE (ptrtype1
))))
1214 /* If the decl is accessed via a MEM_REF, reconstruct the base
1215 we can use for TBAA and an appropriately adjusted offset. */
1217 while (handled_component_p (dbase2
))
1218 dbase2
= TREE_OPERAND (dbase2
, 0);
1221 if (TREE_CODE (dbase2
) == MEM_REF
1222 || TREE_CODE (dbase2
) == TARGET_MEM_REF
)
1224 offset_int moff
= mem_ref_offset (dbase2
);
1225 moff
<<= LOG2_BITS_PER_UNIT
;
1226 if (wi::neg_p (moff
))
1227 doffset1
-= (-moff
).to_short_addr ();
1229 doffset2
-= moff
.to_short_addr ();
1232 /* If either reference is view-converted, give up now. */
1233 if (same_type_for_tbaa (TREE_TYPE (base1
), TREE_TYPE (ptrtype1
)) != 1
1234 || same_type_for_tbaa (TREE_TYPE (dbase2
), TREE_TYPE (base2
)) != 1)
1237 /* If both references are through the same type, they do not alias
1238 if the accesses do not overlap. This does extra disambiguation
1239 for mixed/pointer accesses but requires strict aliasing.
1240 For MEM_REFs we require that the component-ref offset we computed
1241 is relative to the start of the type which we ensure by
1242 comparing rvalue and access type and disregarding the constant
1244 if ((TREE_CODE (base1
) != TARGET_MEM_REF
1245 || (!TMR_INDEX (base1
) && !TMR_INDEX2 (base1
)))
1246 && same_type_for_tbaa (TREE_TYPE (base1
), TREE_TYPE (dbase2
)) == 1)
1247 return ranges_overlap_p (doffset1
, max_size1
, doffset2
, max_size2
);
1250 && nonoverlapping_component_refs_p (ref1
, ref2
))
1253 /* Do access-path based disambiguation. */
1255 && (handled_component_p (ref1
) || handled_component_p (ref2
)))
1256 return aliasing_component_refs_p (ref1
,
1257 ref1_alias_set
, base1_alias_set
,
1260 ref2_alias_set
, base2_alias_set
,
1261 offset2
, max_size2
, true);
1266 /* Return true if two indirect references based on *PTR1
1267 and *PTR2 constrained to [OFFSET1, OFFSET1 + MAX_SIZE1) and
1268 [OFFSET2, OFFSET2 + MAX_SIZE2) may alias. *PTR1 and *PTR2 have
1269 the alias sets BASE1_ALIAS_SET and BASE2_ALIAS_SET which can be -1
1270 in which case they are computed on-demand. REF1 and REF2
1271 if non-NULL are the complete memory reference trees. */
1274 indirect_refs_may_alias_p (tree ref1 ATTRIBUTE_UNUSED
, tree base1
,
1275 HOST_WIDE_INT offset1
, HOST_WIDE_INT max_size1
,
1276 alias_set_type ref1_alias_set
,
1277 alias_set_type base1_alias_set
,
1278 tree ref2 ATTRIBUTE_UNUSED
, tree base2
,
1279 HOST_WIDE_INT offset2
, HOST_WIDE_INT max_size2
,
1280 alias_set_type ref2_alias_set
,
1281 alias_set_type base2_alias_set
, bool tbaa_p
)
1285 tree ptrtype1
, ptrtype2
;
1287 gcc_checking_assert ((TREE_CODE (base1
) == MEM_REF
1288 || TREE_CODE (base1
) == TARGET_MEM_REF
)
1289 && (TREE_CODE (base2
) == MEM_REF
1290 || TREE_CODE (base2
) == TARGET_MEM_REF
));
1292 ptr1
= TREE_OPERAND (base1
, 0);
1293 ptr2
= TREE_OPERAND (base2
, 0);
1295 /* If both bases are based on pointers they cannot alias if they may not
1296 point to the same memory object or if they point to the same object
1297 and the accesses do not overlap. */
1298 if ((!cfun
|| gimple_in_ssa_p (cfun
))
1299 && operand_equal_p (ptr1
, ptr2
, 0)
1300 && (((TREE_CODE (base1
) != TARGET_MEM_REF
1301 || (!TMR_INDEX (base1
) && !TMR_INDEX2 (base1
)))
1302 && (TREE_CODE (base2
) != TARGET_MEM_REF
1303 || (!TMR_INDEX (base2
) && !TMR_INDEX2 (base2
))))
1304 || (TREE_CODE (base1
) == TARGET_MEM_REF
1305 && TREE_CODE (base2
) == TARGET_MEM_REF
1306 && (TMR_STEP (base1
) == TMR_STEP (base2
)
1307 || (TMR_STEP (base1
) && TMR_STEP (base2
)
1308 && operand_equal_p (TMR_STEP (base1
),
1309 TMR_STEP (base2
), 0)))
1310 && (TMR_INDEX (base1
) == TMR_INDEX (base2
)
1311 || (TMR_INDEX (base1
) && TMR_INDEX (base2
)
1312 && operand_equal_p (TMR_INDEX (base1
),
1313 TMR_INDEX (base2
), 0)))
1314 && (TMR_INDEX2 (base1
) == TMR_INDEX2 (base2
)
1315 || (TMR_INDEX2 (base1
) && TMR_INDEX2 (base2
)
1316 && operand_equal_p (TMR_INDEX2 (base1
),
1317 TMR_INDEX2 (base2
), 0))))))
1320 /* The offset embedded in MEM_REFs can be negative. Bias them
1321 so that the resulting offset adjustment is positive. */
1322 moff
= mem_ref_offset (base1
);
1323 moff
<<= LOG2_BITS_PER_UNIT
;
1324 if (wi::neg_p (moff
))
1325 offset2
+= (-moff
).to_short_addr ();
1327 offset1
+= moff
.to_shwi ();
1328 moff
= mem_ref_offset (base2
);
1329 moff
<<= LOG2_BITS_PER_UNIT
;
1330 if (wi::neg_p (moff
))
1331 offset1
+= (-moff
).to_short_addr ();
1333 offset2
+= moff
.to_short_addr ();
1334 return ranges_overlap_p (offset1
, max_size1
, offset2
, max_size2
);
1336 if (!ptr_derefs_may_alias_p (ptr1
, ptr2
))
1339 /* Disambiguations that rely on strict aliasing rules follow. */
1340 if (!flag_strict_aliasing
|| !tbaa_p
)
1343 ptrtype1
= TREE_TYPE (TREE_OPERAND (base1
, 1));
1344 ptrtype2
= TREE_TYPE (TREE_OPERAND (base2
, 1));
1346 /* If the alias set for a pointer access is zero all bets are off. */
1347 if (base1_alias_set
== 0
1348 || base2_alias_set
== 0)
1351 /* If both references are through the same type, they do not alias
1352 if the accesses do not overlap. This does extra disambiguation
1353 for mixed/pointer accesses but requires strict aliasing. */
1354 if ((TREE_CODE (base1
) != TARGET_MEM_REF
1355 || (!TMR_INDEX (base1
) && !TMR_INDEX2 (base1
)))
1356 && (TREE_CODE (base2
) != TARGET_MEM_REF
1357 || (!TMR_INDEX (base2
) && !TMR_INDEX2 (base2
)))
1358 && same_type_for_tbaa (TREE_TYPE (base1
), TREE_TYPE (ptrtype1
)) == 1
1359 && same_type_for_tbaa (TREE_TYPE (base2
), TREE_TYPE (ptrtype2
)) == 1
1360 && same_type_for_tbaa (TREE_TYPE (ptrtype1
),
1361 TREE_TYPE (ptrtype2
)) == 1
1362 /* But avoid treating arrays as "objects", instead assume they
1363 can overlap by an exact multiple of their element size. */
1364 && TREE_CODE (TREE_TYPE (ptrtype1
)) != ARRAY_TYPE
)
1365 return ranges_overlap_p (offset1
, max_size1
, offset2
, max_size2
);
1367 /* Do type-based disambiguation. */
1368 if (base1_alias_set
!= base2_alias_set
1369 && !alias_sets_conflict_p (base1_alias_set
, base2_alias_set
))
1372 /* If either reference is view-converted, give up now. */
1373 if (same_type_for_tbaa (TREE_TYPE (base1
), TREE_TYPE (ptrtype1
)) != 1
1374 || same_type_for_tbaa (TREE_TYPE (base2
), TREE_TYPE (ptrtype2
)) != 1)
1378 && nonoverlapping_component_refs_p (ref1
, ref2
))
1381 /* Do access-path based disambiguation. */
1383 && (handled_component_p (ref1
) || handled_component_p (ref2
)))
1384 return aliasing_component_refs_p (ref1
,
1385 ref1_alias_set
, base1_alias_set
,
1388 ref2_alias_set
, base2_alias_set
,
1389 offset2
, max_size2
, false);
1394 /* Return true, if the two memory references REF1 and REF2 may alias. */
1397 refs_may_alias_p_1 (ao_ref
*ref1
, ao_ref
*ref2
, bool tbaa_p
)
1400 HOST_WIDE_INT offset1
= 0, offset2
= 0;
1401 HOST_WIDE_INT max_size1
= -1, max_size2
= -1;
1402 bool var1_p
, var2_p
, ind1_p
, ind2_p
;
1404 gcc_checking_assert ((!ref1
->ref
1405 || TREE_CODE (ref1
->ref
) == SSA_NAME
1406 || DECL_P (ref1
->ref
)
1407 || TREE_CODE (ref1
->ref
) == STRING_CST
1408 || handled_component_p (ref1
->ref
)
1409 || TREE_CODE (ref1
->ref
) == MEM_REF
1410 || TREE_CODE (ref1
->ref
) == TARGET_MEM_REF
)
1412 || TREE_CODE (ref2
->ref
) == SSA_NAME
1413 || DECL_P (ref2
->ref
)
1414 || TREE_CODE (ref2
->ref
) == STRING_CST
1415 || handled_component_p (ref2
->ref
)
1416 || TREE_CODE (ref2
->ref
) == MEM_REF
1417 || TREE_CODE (ref2
->ref
) == TARGET_MEM_REF
));
1419 /* Decompose the references into their base objects and the access. */
1420 base1
= ao_ref_base (ref1
);
1421 offset1
= ref1
->offset
;
1422 max_size1
= ref1
->max_size
;
1423 base2
= ao_ref_base (ref2
);
1424 offset2
= ref2
->offset
;
1425 max_size2
= ref2
->max_size
;
1427 /* We can end up with registers or constants as bases for example from
1428 *D.1663_44 = VIEW_CONVERT_EXPR<struct DB_LSN>(__tmp$B0F64_59);
1429 which is seen as a struct copy. */
1430 if (TREE_CODE (base1
) == SSA_NAME
1431 || TREE_CODE (base1
) == CONST_DECL
1432 || TREE_CODE (base1
) == CONSTRUCTOR
1433 || TREE_CODE (base1
) == ADDR_EXPR
1434 || CONSTANT_CLASS_P (base1
)
1435 || TREE_CODE (base2
) == SSA_NAME
1436 || TREE_CODE (base2
) == CONST_DECL
1437 || TREE_CODE (base2
) == CONSTRUCTOR
1438 || TREE_CODE (base2
) == ADDR_EXPR
1439 || CONSTANT_CLASS_P (base2
))
1442 /* We can end up referring to code via function and label decls.
1443 As we likely do not properly track code aliases conservatively
1445 if (TREE_CODE (base1
) == FUNCTION_DECL
1446 || TREE_CODE (base1
) == LABEL_DECL
1447 || TREE_CODE (base2
) == FUNCTION_DECL
1448 || TREE_CODE (base2
) == LABEL_DECL
)
1451 /* Two volatile accesses always conflict. */
1452 if (ref1
->volatile_p
1453 && ref2
->volatile_p
)
1456 /* Defer to simple offset based disambiguation if we have
1457 references based on two decls. Do this before defering to
1458 TBAA to handle must-alias cases in conformance with the
1459 GCC extension of allowing type-punning through unions. */
1460 var1_p
= DECL_P (base1
);
1461 var2_p
= DECL_P (base2
);
1462 if (var1_p
&& var2_p
)
1463 return decl_refs_may_alias_p (ref1
->ref
, base1
, offset1
, max_size1
,
1464 ref2
->ref
, base2
, offset2
, max_size2
);
1466 /* Handle restrict based accesses.
1467 ??? ao_ref_base strips inner MEM_REF [&decl], recover from that
1469 tree rbase1
= base1
;
1470 tree rbase2
= base2
;
1475 while (handled_component_p (rbase1
))
1476 rbase1
= TREE_OPERAND (rbase1
, 0);
1482 while (handled_component_p (rbase2
))
1483 rbase2
= TREE_OPERAND (rbase2
, 0);
1485 if (rbase1
&& rbase2
1486 && (TREE_CODE (base1
) == MEM_REF
|| TREE_CODE (base1
) == TARGET_MEM_REF
)
1487 && (TREE_CODE (base2
) == MEM_REF
|| TREE_CODE (base2
) == TARGET_MEM_REF
)
1488 /* If the accesses are in the same restrict clique... */
1489 && MR_DEPENDENCE_CLIQUE (base1
) == MR_DEPENDENCE_CLIQUE (base2
)
1490 /* But based on different pointers they do not alias. */
1491 && MR_DEPENDENCE_BASE (base1
) != MR_DEPENDENCE_BASE (base2
))
1494 ind1_p
= (TREE_CODE (base1
) == MEM_REF
1495 || TREE_CODE (base1
) == TARGET_MEM_REF
);
1496 ind2_p
= (TREE_CODE (base2
) == MEM_REF
1497 || TREE_CODE (base2
) == TARGET_MEM_REF
);
1499 /* Canonicalize the pointer-vs-decl case. */
1500 if (ind1_p
&& var2_p
)
1502 std::swap (offset1
, offset2
);
1503 std::swap (max_size1
, max_size2
);
1504 std::swap (base1
, base2
);
1505 std::swap (ref1
, ref2
);
1512 /* First defer to TBAA if possible. */
1514 && flag_strict_aliasing
1515 && !alias_sets_conflict_p (ao_ref_alias_set (ref1
),
1516 ao_ref_alias_set (ref2
)))
1519 /* Dispatch to the pointer-vs-decl or pointer-vs-pointer disambiguators. */
1520 if (var1_p
&& ind2_p
)
1521 return indirect_ref_may_alias_decl_p (ref2
->ref
, base2
,
1523 ao_ref_alias_set (ref2
),
1524 ao_ref_base_alias_set (ref2
),
1527 ao_ref_alias_set (ref1
),
1528 ao_ref_base_alias_set (ref1
),
1530 else if (ind1_p
&& ind2_p
)
1531 return indirect_refs_may_alias_p (ref1
->ref
, base1
,
1533 ao_ref_alias_set (ref1
),
1534 ao_ref_base_alias_set (ref1
),
1537 ao_ref_alias_set (ref2
),
1538 ao_ref_base_alias_set (ref2
),
1545 refs_may_alias_p (tree ref1
, ao_ref
*ref2
)
1548 ao_ref_init (&r1
, ref1
);
1549 return refs_may_alias_p_1 (&r1
, ref2
, true);
1553 refs_may_alias_p (tree ref1
, tree ref2
)
1557 ao_ref_init (&r1
, ref1
);
1558 ao_ref_init (&r2
, ref2
);
1559 res
= refs_may_alias_p_1 (&r1
, &r2
, true);
1561 ++alias_stats
.refs_may_alias_p_may_alias
;
1563 ++alias_stats
.refs_may_alias_p_no_alias
;
1567 /* Returns true if there is a anti-dependence for the STORE that
1568 executes after the LOAD. */
1571 refs_anti_dependent_p (tree load
, tree store
)
1574 ao_ref_init (&r1
, load
);
1575 ao_ref_init (&r2
, store
);
1576 return refs_may_alias_p_1 (&r1
, &r2
, false);
1579 /* Returns true if there is a output dependence for the stores
1580 STORE1 and STORE2. */
1583 refs_output_dependent_p (tree store1
, tree store2
)
1586 ao_ref_init (&r1
, store1
);
1587 ao_ref_init (&r2
, store2
);
1588 return refs_may_alias_p_1 (&r1
, &r2
, false);
1591 /* If the call CALL may use the memory reference REF return true,
1592 otherwise return false. */
1595 ref_maybe_used_by_call_p_1 (gcall
*call
, ao_ref
*ref
)
1599 int flags
= gimple_call_flags (call
);
1601 /* Const functions without a static chain do not implicitly use memory. */
1602 if (!gimple_call_chain (call
)
1603 && (flags
& (ECF_CONST
|ECF_NOVOPS
)))
1606 base
= ao_ref_base (ref
);
1610 /* A call that is not without side-effects might involve volatile
1611 accesses and thus conflicts with all other volatile accesses. */
1612 if (ref
->volatile_p
)
1615 /* If the reference is based on a decl that is not aliased the call
1616 cannot possibly use it. */
1618 && !may_be_aliased (base
)
1619 /* But local statics can be used through recursion. */
1620 && !is_global_var (base
))
1623 callee
= gimple_call_fndecl (call
);
1625 /* Handle those builtin functions explicitly that do not act as
1626 escape points. See tree-ssa-structalias.c:find_func_aliases
1627 for the list of builtins we might need to handle here. */
1628 if (callee
!= NULL_TREE
1629 && gimple_call_builtin_p (call
, BUILT_IN_NORMAL
))
1630 switch (DECL_FUNCTION_CODE (callee
))
1632 /* All the following functions read memory pointed to by
1633 their second argument. strcat/strncat additionally
1634 reads memory pointed to by the first argument. */
1635 case BUILT_IN_STRCAT
:
1636 case BUILT_IN_STRNCAT
:
1639 ao_ref_init_from_ptr_and_size (&dref
,
1640 gimple_call_arg (call
, 0),
1642 if (refs_may_alias_p_1 (&dref
, ref
, false))
1646 case BUILT_IN_STRCPY
:
1647 case BUILT_IN_STRNCPY
:
1648 case BUILT_IN_MEMCPY
:
1649 case BUILT_IN_MEMMOVE
:
1650 case BUILT_IN_MEMPCPY
:
1651 case BUILT_IN_STPCPY
:
1652 case BUILT_IN_STPNCPY
:
1653 case BUILT_IN_TM_MEMCPY
:
1654 case BUILT_IN_TM_MEMMOVE
:
1657 tree size
= NULL_TREE
;
1658 if (gimple_call_num_args (call
) == 3)
1659 size
= gimple_call_arg (call
, 2);
1660 ao_ref_init_from_ptr_and_size (&dref
,
1661 gimple_call_arg (call
, 1),
1663 return refs_may_alias_p_1 (&dref
, ref
, false);
1665 case BUILT_IN_STRCAT_CHK
:
1666 case BUILT_IN_STRNCAT_CHK
:
1669 ao_ref_init_from_ptr_and_size (&dref
,
1670 gimple_call_arg (call
, 0),
1672 if (refs_may_alias_p_1 (&dref
, ref
, false))
1676 case BUILT_IN_STRCPY_CHK
:
1677 case BUILT_IN_STRNCPY_CHK
:
1678 case BUILT_IN_MEMCPY_CHK
:
1679 case BUILT_IN_MEMMOVE_CHK
:
1680 case BUILT_IN_MEMPCPY_CHK
:
1681 case BUILT_IN_STPCPY_CHK
:
1682 case BUILT_IN_STPNCPY_CHK
:
1685 tree size
= NULL_TREE
;
1686 if (gimple_call_num_args (call
) == 4)
1687 size
= gimple_call_arg (call
, 2);
1688 ao_ref_init_from_ptr_and_size (&dref
,
1689 gimple_call_arg (call
, 1),
1691 return refs_may_alias_p_1 (&dref
, ref
, false);
1693 case BUILT_IN_BCOPY
:
1696 tree size
= gimple_call_arg (call
, 2);
1697 ao_ref_init_from_ptr_and_size (&dref
,
1698 gimple_call_arg (call
, 0),
1700 return refs_may_alias_p_1 (&dref
, ref
, false);
1703 /* The following functions read memory pointed to by their
1705 CASE_BUILT_IN_TM_LOAD (1):
1706 CASE_BUILT_IN_TM_LOAD (2):
1707 CASE_BUILT_IN_TM_LOAD (4):
1708 CASE_BUILT_IN_TM_LOAD (8):
1709 CASE_BUILT_IN_TM_LOAD (FLOAT
):
1710 CASE_BUILT_IN_TM_LOAD (DOUBLE
):
1711 CASE_BUILT_IN_TM_LOAD (LDOUBLE
):
1712 CASE_BUILT_IN_TM_LOAD (M64
):
1713 CASE_BUILT_IN_TM_LOAD (M128
):
1714 CASE_BUILT_IN_TM_LOAD (M256
):
1715 case BUILT_IN_TM_LOG
:
1716 case BUILT_IN_TM_LOG_1
:
1717 case BUILT_IN_TM_LOG_2
:
1718 case BUILT_IN_TM_LOG_4
:
1719 case BUILT_IN_TM_LOG_8
:
1720 case BUILT_IN_TM_LOG_FLOAT
:
1721 case BUILT_IN_TM_LOG_DOUBLE
:
1722 case BUILT_IN_TM_LOG_LDOUBLE
:
1723 case BUILT_IN_TM_LOG_M64
:
1724 case BUILT_IN_TM_LOG_M128
:
1725 case BUILT_IN_TM_LOG_M256
:
1726 return ptr_deref_may_alias_ref_p_1 (gimple_call_arg (call
, 0), ref
);
1728 /* These read memory pointed to by the first argument. */
1729 case BUILT_IN_STRDUP
:
1730 case BUILT_IN_STRNDUP
:
1731 case BUILT_IN_REALLOC
:
1734 tree size
= NULL_TREE
;
1735 if (gimple_call_num_args (call
) == 2)
1736 size
= gimple_call_arg (call
, 1);
1737 ao_ref_init_from_ptr_and_size (&dref
,
1738 gimple_call_arg (call
, 0),
1740 return refs_may_alias_p_1 (&dref
, ref
, false);
1742 /* These read memory pointed to by the first argument. */
1743 case BUILT_IN_INDEX
:
1744 case BUILT_IN_STRCHR
:
1745 case BUILT_IN_STRRCHR
:
1748 ao_ref_init_from_ptr_and_size (&dref
,
1749 gimple_call_arg (call
, 0),
1751 return refs_may_alias_p_1 (&dref
, ref
, false);
1753 /* These read memory pointed to by the first argument with size
1754 in the third argument. */
1755 case BUILT_IN_MEMCHR
:
1758 ao_ref_init_from_ptr_and_size (&dref
,
1759 gimple_call_arg (call
, 0),
1760 gimple_call_arg (call
, 2));
1761 return refs_may_alias_p_1 (&dref
, ref
, false);
1763 /* These read memory pointed to by the first and second arguments. */
1764 case BUILT_IN_STRSTR
:
1765 case BUILT_IN_STRPBRK
:
1768 ao_ref_init_from_ptr_and_size (&dref
,
1769 gimple_call_arg (call
, 0),
1771 if (refs_may_alias_p_1 (&dref
, ref
, false))
1773 ao_ref_init_from_ptr_and_size (&dref
,
1774 gimple_call_arg (call
, 1),
1776 return refs_may_alias_p_1 (&dref
, ref
, false);
1779 /* The following builtins do not read from memory. */
1781 case BUILT_IN_MALLOC
:
1782 case BUILT_IN_POSIX_MEMALIGN
:
1783 case BUILT_IN_ALIGNED_ALLOC
:
1784 case BUILT_IN_CALLOC
:
1785 case BUILT_IN_ALLOCA
:
1786 case BUILT_IN_ALLOCA_WITH_ALIGN
:
1787 case BUILT_IN_STACK_SAVE
:
1788 case BUILT_IN_STACK_RESTORE
:
1789 case BUILT_IN_MEMSET
:
1790 case BUILT_IN_TM_MEMSET
:
1791 case BUILT_IN_MEMSET_CHK
:
1792 case BUILT_IN_FREXP
:
1793 case BUILT_IN_FREXPF
:
1794 case BUILT_IN_FREXPL
:
1795 case BUILT_IN_GAMMA_R
:
1796 case BUILT_IN_GAMMAF_R
:
1797 case BUILT_IN_GAMMAL_R
:
1798 case BUILT_IN_LGAMMA_R
:
1799 case BUILT_IN_LGAMMAF_R
:
1800 case BUILT_IN_LGAMMAL_R
:
1802 case BUILT_IN_MODFF
:
1803 case BUILT_IN_MODFL
:
1804 case BUILT_IN_REMQUO
:
1805 case BUILT_IN_REMQUOF
:
1806 case BUILT_IN_REMQUOL
:
1807 case BUILT_IN_SINCOS
:
1808 case BUILT_IN_SINCOSF
:
1809 case BUILT_IN_SINCOSL
:
1810 case BUILT_IN_ASSUME_ALIGNED
:
1811 case BUILT_IN_VA_END
:
1813 /* __sync_* builtins and some OpenMP builtins act as threading
1815 #undef DEF_SYNC_BUILTIN
1816 #define DEF_SYNC_BUILTIN(ENUM, NAME, TYPE, ATTRS) case ENUM:
1817 #include "sync-builtins.def"
1818 #undef DEF_SYNC_BUILTIN
1819 case BUILT_IN_GOMP_ATOMIC_START
:
1820 case BUILT_IN_GOMP_ATOMIC_END
:
1821 case BUILT_IN_GOMP_BARRIER
:
1822 case BUILT_IN_GOMP_BARRIER_CANCEL
:
1823 case BUILT_IN_GOMP_TASKWAIT
:
1824 case BUILT_IN_GOMP_TASKGROUP_END
:
1825 case BUILT_IN_GOMP_CRITICAL_START
:
1826 case BUILT_IN_GOMP_CRITICAL_END
:
1827 case BUILT_IN_GOMP_CRITICAL_NAME_START
:
1828 case BUILT_IN_GOMP_CRITICAL_NAME_END
:
1829 case BUILT_IN_GOMP_LOOP_END
:
1830 case BUILT_IN_GOMP_LOOP_END_CANCEL
:
1831 case BUILT_IN_GOMP_ORDERED_START
:
1832 case BUILT_IN_GOMP_ORDERED_END
:
1833 case BUILT_IN_GOMP_SECTIONS_END
:
1834 case BUILT_IN_GOMP_SECTIONS_END_CANCEL
:
1835 case BUILT_IN_GOMP_SINGLE_COPY_START
:
1836 case BUILT_IN_GOMP_SINGLE_COPY_END
:
1840 /* Fallthru to general call handling. */;
1843 /* Check if base is a global static variable that is not read
1845 if (callee
!= NULL_TREE
&& VAR_P (base
) && TREE_STATIC (base
))
1847 struct cgraph_node
*node
= cgraph_node::get (callee
);
1850 /* FIXME: Callee can be an OMP builtin that does not have a call graph
1851 node yet. We should enforce that there are nodes for all decls in the
1852 IL and remove this check instead. */
1854 && (not_read
= ipa_reference_get_not_read_global (node
))
1855 && bitmap_bit_p (not_read
, ipa_reference_var_uid (base
)))
1859 /* Check if the base variable is call-used. */
1862 if (pt_solution_includes (gimple_call_use_set (call
), base
))
1865 else if ((TREE_CODE (base
) == MEM_REF
1866 || TREE_CODE (base
) == TARGET_MEM_REF
)
1867 && TREE_CODE (TREE_OPERAND (base
, 0)) == SSA_NAME
)
1869 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (TREE_OPERAND (base
, 0));
1873 if (pt_solutions_intersect (gimple_call_use_set (call
), &pi
->pt
))
1879 /* Inspect call arguments for passed-by-value aliases. */
1881 for (i
= 0; i
< gimple_call_num_args (call
); ++i
)
1883 tree op
= gimple_call_arg (call
, i
);
1884 int flags
= gimple_call_arg_flags (call
, i
);
1886 if (flags
& EAF_UNUSED
)
1889 if (TREE_CODE (op
) == WITH_SIZE_EXPR
)
1890 op
= TREE_OPERAND (op
, 0);
1892 if (TREE_CODE (op
) != SSA_NAME
1893 && !is_gimple_min_invariant (op
))
1896 ao_ref_init (&r
, op
);
1897 if (refs_may_alias_p_1 (&r
, ref
, true))
1906 ref_maybe_used_by_call_p (gcall
*call
, ao_ref
*ref
)
1909 res
= ref_maybe_used_by_call_p_1 (call
, ref
);
1911 ++alias_stats
.ref_maybe_used_by_call_p_may_alias
;
1913 ++alias_stats
.ref_maybe_used_by_call_p_no_alias
;
1918 /* If the statement STMT may use the memory reference REF return
1919 true, otherwise return false. */
1922 ref_maybe_used_by_stmt_p (gimple
*stmt
, ao_ref
*ref
)
1924 if (is_gimple_assign (stmt
))
1928 /* All memory assign statements are single. */
1929 if (!gimple_assign_single_p (stmt
))
1932 rhs
= gimple_assign_rhs1 (stmt
);
1933 if (is_gimple_reg (rhs
)
1934 || is_gimple_min_invariant (rhs
)
1935 || gimple_assign_rhs_code (stmt
) == CONSTRUCTOR
)
1938 return refs_may_alias_p (rhs
, ref
);
1940 else if (is_gimple_call (stmt
))
1941 return ref_maybe_used_by_call_p (as_a
<gcall
*> (stmt
), ref
);
1942 else if (greturn
*return_stmt
= dyn_cast
<greturn
*> (stmt
))
1944 tree retval
= gimple_return_retval (return_stmt
);
1946 && TREE_CODE (retval
) != SSA_NAME
1947 && !is_gimple_min_invariant (retval
)
1948 && refs_may_alias_p (retval
, ref
))
1950 /* If ref escapes the function then the return acts as a use. */
1951 tree base
= ao_ref_base (ref
);
1954 else if (DECL_P (base
))
1955 return is_global_var (base
);
1956 else if (TREE_CODE (base
) == MEM_REF
1957 || TREE_CODE (base
) == TARGET_MEM_REF
)
1958 return ptr_deref_may_alias_global_p (TREE_OPERAND (base
, 0));
1966 ref_maybe_used_by_stmt_p (gimple
*stmt
, tree ref
)
1969 ao_ref_init (&r
, ref
);
1970 return ref_maybe_used_by_stmt_p (stmt
, &r
);
1973 /* If the call in statement CALL may clobber the memory reference REF
1974 return true, otherwise return false. */
1977 call_may_clobber_ref_p_1 (gcall
*call
, ao_ref
*ref
)
1982 /* If the call is pure or const it cannot clobber anything. */
1983 if (gimple_call_flags (call
)
1984 & (ECF_PURE
|ECF_CONST
|ECF_LOOPING_CONST_OR_PURE
|ECF_NOVOPS
))
1986 if (gimple_call_internal_p (call
))
1987 switch (gimple_call_internal_fn (call
))
1989 /* Treat these internal calls like ECF_PURE for aliasing,
1990 they don't write to any memory the program should care about.
1991 They have important other side-effects, and read memory,
1992 so can't be ECF_NOVOPS. */
1993 case IFN_UBSAN_NULL
:
1994 case IFN_UBSAN_BOUNDS
:
1995 case IFN_UBSAN_VPTR
:
1996 case IFN_UBSAN_OBJECT_SIZE
:
1997 case IFN_ASAN_CHECK
:
2003 base
= ao_ref_base (ref
);
2007 if (TREE_CODE (base
) == SSA_NAME
2008 || CONSTANT_CLASS_P (base
))
2011 /* A call that is not without side-effects might involve volatile
2012 accesses and thus conflicts with all other volatile accesses. */
2013 if (ref
->volatile_p
)
2016 /* If the reference is based on a decl that is not aliased the call
2017 cannot possibly clobber it. */
2019 && !may_be_aliased (base
)
2020 /* But local non-readonly statics can be modified through recursion
2021 or the call may implement a threading barrier which we must
2022 treat as may-def. */
2023 && (TREE_READONLY (base
)
2024 || !is_global_var (base
)))
2027 callee
= gimple_call_fndecl (call
);
2029 /* Handle those builtin functions explicitly that do not act as
2030 escape points. See tree-ssa-structalias.c:find_func_aliases
2031 for the list of builtins we might need to handle here. */
2032 if (callee
!= NULL_TREE
2033 && gimple_call_builtin_p (call
, BUILT_IN_NORMAL
))
2034 switch (DECL_FUNCTION_CODE (callee
))
2036 /* All the following functions clobber memory pointed to by
2037 their first argument. */
2038 case BUILT_IN_STRCPY
:
2039 case BUILT_IN_STRNCPY
:
2040 case BUILT_IN_MEMCPY
:
2041 case BUILT_IN_MEMMOVE
:
2042 case BUILT_IN_MEMPCPY
:
2043 case BUILT_IN_STPCPY
:
2044 case BUILT_IN_STPNCPY
:
2045 case BUILT_IN_STRCAT
:
2046 case BUILT_IN_STRNCAT
:
2047 case BUILT_IN_MEMSET
:
2048 case BUILT_IN_TM_MEMSET
:
2049 CASE_BUILT_IN_TM_STORE (1):
2050 CASE_BUILT_IN_TM_STORE (2):
2051 CASE_BUILT_IN_TM_STORE (4):
2052 CASE_BUILT_IN_TM_STORE (8):
2053 CASE_BUILT_IN_TM_STORE (FLOAT
):
2054 CASE_BUILT_IN_TM_STORE (DOUBLE
):
2055 CASE_BUILT_IN_TM_STORE (LDOUBLE
):
2056 CASE_BUILT_IN_TM_STORE (M64
):
2057 CASE_BUILT_IN_TM_STORE (M128
):
2058 CASE_BUILT_IN_TM_STORE (M256
):
2059 case BUILT_IN_TM_MEMCPY
:
2060 case BUILT_IN_TM_MEMMOVE
:
2063 tree size
= NULL_TREE
;
2064 /* Don't pass in size for strncat, as the maximum size
2065 is strlen (dest) + n + 1 instead of n, resp.
2066 n + 1 at dest + strlen (dest), but strlen (dest) isn't
2068 if (gimple_call_num_args (call
) == 3
2069 && DECL_FUNCTION_CODE (callee
) != BUILT_IN_STRNCAT
)
2070 size
= gimple_call_arg (call
, 2);
2071 ao_ref_init_from_ptr_and_size (&dref
,
2072 gimple_call_arg (call
, 0),
2074 return refs_may_alias_p_1 (&dref
, ref
, false);
2076 case BUILT_IN_STRCPY_CHK
:
2077 case BUILT_IN_STRNCPY_CHK
:
2078 case BUILT_IN_MEMCPY_CHK
:
2079 case BUILT_IN_MEMMOVE_CHK
:
2080 case BUILT_IN_MEMPCPY_CHK
:
2081 case BUILT_IN_STPCPY_CHK
:
2082 case BUILT_IN_STPNCPY_CHK
:
2083 case BUILT_IN_STRCAT_CHK
:
2084 case BUILT_IN_STRNCAT_CHK
:
2085 case BUILT_IN_MEMSET_CHK
:
2088 tree size
= NULL_TREE
;
2089 /* Don't pass in size for __strncat_chk, as the maximum size
2090 is strlen (dest) + n + 1 instead of n, resp.
2091 n + 1 at dest + strlen (dest), but strlen (dest) isn't
2093 if (gimple_call_num_args (call
) == 4
2094 && DECL_FUNCTION_CODE (callee
) != BUILT_IN_STRNCAT_CHK
)
2095 size
= gimple_call_arg (call
, 2);
2096 ao_ref_init_from_ptr_and_size (&dref
,
2097 gimple_call_arg (call
, 0),
2099 return refs_may_alias_p_1 (&dref
, ref
, false);
2101 case BUILT_IN_BCOPY
:
2104 tree size
= gimple_call_arg (call
, 2);
2105 ao_ref_init_from_ptr_and_size (&dref
,
2106 gimple_call_arg (call
, 1),
2108 return refs_may_alias_p_1 (&dref
, ref
, false);
2110 /* Allocating memory does not have any side-effects apart from
2111 being the definition point for the pointer. */
2112 case BUILT_IN_MALLOC
:
2113 case BUILT_IN_ALIGNED_ALLOC
:
2114 case BUILT_IN_CALLOC
:
2115 case BUILT_IN_STRDUP
:
2116 case BUILT_IN_STRNDUP
:
2117 /* Unix98 specifies that errno is set on allocation failure. */
2119 && targetm
.ref_may_alias_errno (ref
))
2122 case BUILT_IN_STACK_SAVE
:
2123 case BUILT_IN_ALLOCA
:
2124 case BUILT_IN_ALLOCA_WITH_ALIGN
:
2125 case BUILT_IN_ASSUME_ALIGNED
:
2127 /* But posix_memalign stores a pointer into the memory pointed to
2128 by its first argument. */
2129 case BUILT_IN_POSIX_MEMALIGN
:
2131 tree ptrptr
= gimple_call_arg (call
, 0);
2133 ao_ref_init_from_ptr_and_size (&dref
, ptrptr
,
2134 TYPE_SIZE_UNIT (ptr_type_node
));
2135 return (refs_may_alias_p_1 (&dref
, ref
, false)
2137 && targetm
.ref_may_alias_errno (ref
)));
2139 /* Freeing memory kills the pointed-to memory. More importantly
2140 the call has to serve as a barrier for moving loads and stores
2143 case BUILT_IN_VA_END
:
2145 tree ptr
= gimple_call_arg (call
, 0);
2146 return ptr_deref_may_alias_ref_p_1 (ptr
, ref
);
2148 /* Realloc serves both as allocation point and deallocation point. */
2149 case BUILT_IN_REALLOC
:
2151 tree ptr
= gimple_call_arg (call
, 0);
2152 /* Unix98 specifies that errno is set on allocation failure. */
2153 return ((flag_errno_math
2154 && targetm
.ref_may_alias_errno (ref
))
2155 || ptr_deref_may_alias_ref_p_1 (ptr
, ref
));
2157 case BUILT_IN_GAMMA_R
:
2158 case BUILT_IN_GAMMAF_R
:
2159 case BUILT_IN_GAMMAL_R
:
2160 case BUILT_IN_LGAMMA_R
:
2161 case BUILT_IN_LGAMMAF_R
:
2162 case BUILT_IN_LGAMMAL_R
:
2164 tree out
= gimple_call_arg (call
, 1);
2165 if (ptr_deref_may_alias_ref_p_1 (out
, ref
))
2167 if (flag_errno_math
)
2171 case BUILT_IN_FREXP
:
2172 case BUILT_IN_FREXPF
:
2173 case BUILT_IN_FREXPL
:
2175 case BUILT_IN_MODFF
:
2176 case BUILT_IN_MODFL
:
2178 tree out
= gimple_call_arg (call
, 1);
2179 return ptr_deref_may_alias_ref_p_1 (out
, ref
);
2181 case BUILT_IN_REMQUO
:
2182 case BUILT_IN_REMQUOF
:
2183 case BUILT_IN_REMQUOL
:
2185 tree out
= gimple_call_arg (call
, 2);
2186 if (ptr_deref_may_alias_ref_p_1 (out
, ref
))
2188 if (flag_errno_math
)
2192 case BUILT_IN_SINCOS
:
2193 case BUILT_IN_SINCOSF
:
2194 case BUILT_IN_SINCOSL
:
2196 tree sin
= gimple_call_arg (call
, 1);
2197 tree cos
= gimple_call_arg (call
, 2);
2198 return (ptr_deref_may_alias_ref_p_1 (sin
, ref
)
2199 || ptr_deref_may_alias_ref_p_1 (cos
, ref
));
2201 /* __sync_* builtins and some OpenMP builtins act as threading
2203 #undef DEF_SYNC_BUILTIN
2204 #define DEF_SYNC_BUILTIN(ENUM, NAME, TYPE, ATTRS) case ENUM:
2205 #include "sync-builtins.def"
2206 #undef DEF_SYNC_BUILTIN
2207 case BUILT_IN_GOMP_ATOMIC_START
:
2208 case BUILT_IN_GOMP_ATOMIC_END
:
2209 case BUILT_IN_GOMP_BARRIER
:
2210 case BUILT_IN_GOMP_BARRIER_CANCEL
:
2211 case BUILT_IN_GOMP_TASKWAIT
:
2212 case BUILT_IN_GOMP_TASKGROUP_END
:
2213 case BUILT_IN_GOMP_CRITICAL_START
:
2214 case BUILT_IN_GOMP_CRITICAL_END
:
2215 case BUILT_IN_GOMP_CRITICAL_NAME_START
:
2216 case BUILT_IN_GOMP_CRITICAL_NAME_END
:
2217 case BUILT_IN_GOMP_LOOP_END
:
2218 case BUILT_IN_GOMP_LOOP_END_CANCEL
:
2219 case BUILT_IN_GOMP_ORDERED_START
:
2220 case BUILT_IN_GOMP_ORDERED_END
:
2221 case BUILT_IN_GOMP_SECTIONS_END
:
2222 case BUILT_IN_GOMP_SECTIONS_END_CANCEL
:
2223 case BUILT_IN_GOMP_SINGLE_COPY_START
:
2224 case BUILT_IN_GOMP_SINGLE_COPY_END
:
2227 /* Fallthru to general call handling. */;
2230 /* Check if base is a global static variable that is not written
2232 if (callee
!= NULL_TREE
&& VAR_P (base
) && TREE_STATIC (base
))
2234 struct cgraph_node
*node
= cgraph_node::get (callee
);
2238 && (not_written
= ipa_reference_get_not_written_global (node
))
2239 && bitmap_bit_p (not_written
, ipa_reference_var_uid (base
)))
2243 /* Check if the base variable is call-clobbered. */
2245 return pt_solution_includes (gimple_call_clobber_set (call
), base
);
2246 else if ((TREE_CODE (base
) == MEM_REF
2247 || TREE_CODE (base
) == TARGET_MEM_REF
)
2248 && TREE_CODE (TREE_OPERAND (base
, 0)) == SSA_NAME
)
2250 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (TREE_OPERAND (base
, 0));
2254 return pt_solutions_intersect (gimple_call_clobber_set (call
), &pi
->pt
);
2260 /* If the call in statement CALL may clobber the memory reference REF
2261 return true, otherwise return false. */
2264 call_may_clobber_ref_p (gcall
*call
, tree ref
)
2268 ao_ref_init (&r
, ref
);
2269 res
= call_may_clobber_ref_p_1 (call
, &r
);
2271 ++alias_stats
.call_may_clobber_ref_p_may_alias
;
2273 ++alias_stats
.call_may_clobber_ref_p_no_alias
;
2278 /* If the statement STMT may clobber the memory reference REF return true,
2279 otherwise return false. */
2282 stmt_may_clobber_ref_p_1 (gimple
*stmt
, ao_ref
*ref
)
2284 if (is_gimple_call (stmt
))
2286 tree lhs
= gimple_call_lhs (stmt
);
2288 && TREE_CODE (lhs
) != SSA_NAME
)
2291 ao_ref_init (&r
, lhs
);
2292 if (refs_may_alias_p_1 (ref
, &r
, true))
2296 return call_may_clobber_ref_p_1 (as_a
<gcall
*> (stmt
), ref
);
2298 else if (gimple_assign_single_p (stmt
))
2300 tree lhs
= gimple_assign_lhs (stmt
);
2301 if (TREE_CODE (lhs
) != SSA_NAME
)
2304 ao_ref_init (&r
, lhs
);
2305 return refs_may_alias_p_1 (ref
, &r
, true);
2308 else if (gimple_code (stmt
) == GIMPLE_ASM
)
2315 stmt_may_clobber_ref_p (gimple
*stmt
, tree ref
)
2318 ao_ref_init (&r
, ref
);
2319 return stmt_may_clobber_ref_p_1 (stmt
, &r
);
2322 /* Return true if store1 and store2 described by corresponding tuples
2323 <BASE, OFFSET, SIZE, MAX_SIZE> have the same size and store to the same
2327 same_addr_size_stores_p (tree base1
, HOST_WIDE_INT offset1
, HOST_WIDE_INT size1
,
2328 HOST_WIDE_INT max_size1
,
2329 tree base2
, HOST_WIDE_INT offset2
, HOST_WIDE_INT size2
,
2330 HOST_WIDE_INT max_size2
)
2332 /* Offsets need to be 0. */
2337 bool base1_obj_p
= SSA_VAR_P (base1
);
2338 bool base2_obj_p
= SSA_VAR_P (base2
);
2340 /* We need one object. */
2341 if (base1_obj_p
== base2_obj_p
)
2343 tree obj
= base1_obj_p
? base1
: base2
;
2345 /* And we need one MEM_REF. */
2346 bool base1_memref_p
= TREE_CODE (base1
) == MEM_REF
;
2347 bool base2_memref_p
= TREE_CODE (base2
) == MEM_REF
;
2348 if (base1_memref_p
== base2_memref_p
)
2350 tree memref
= base1_memref_p
? base1
: base2
;
2352 /* Sizes need to be valid. */
2353 if (max_size1
== -1 || max_size2
== -1
2354 || size1
== -1 || size2
== -1)
2357 /* Max_size needs to match size. */
2358 if (max_size1
!= size1
2359 || max_size2
!= size2
)
2362 /* Sizes need to match. */
2367 /* Check that memref is a store to pointer with singleton points-to info. */
2368 if (!integer_zerop (TREE_OPERAND (memref
, 1)))
2370 tree ptr
= TREE_OPERAND (memref
, 0);
2371 if (TREE_CODE (ptr
) != SSA_NAME
)
2373 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (ptr
);
2374 unsigned int pt_uid
;
2376 || !pt_solution_singleton_or_null_p (&pi
->pt
, &pt_uid
))
2379 /* Be conservative with non-call exceptions when the address might
2381 if (flag_non_call_exceptions
&& pi
->pt
.null
)
2384 /* Check that ptr points relative to obj. */
2385 unsigned int obj_uid
= DECL_PT_UID (obj
);
2386 if (obj_uid
!= pt_uid
)
2389 /* Check that the object size is the same as the store size. That ensures us
2390 that ptr points to the start of obj. */
2391 if (!tree_fits_shwi_p (DECL_SIZE (obj
)))
2393 HOST_WIDE_INT obj_size
= tree_to_shwi (DECL_SIZE (obj
));
2394 return obj_size
== size1
;
2397 /* If STMT kills the memory reference REF return true, otherwise
2401 stmt_kills_ref_p (gimple
*stmt
, ao_ref
*ref
)
2403 if (!ao_ref_base (ref
))
2406 if (gimple_has_lhs (stmt
)
2407 && TREE_CODE (gimple_get_lhs (stmt
)) != SSA_NAME
2408 /* The assignment is not necessarily carried out if it can throw
2409 and we can catch it in the current function where we could inspect
2411 ??? We only need to care about the RHS throwing. For aggregate
2412 assignments or similar calls and non-call exceptions the LHS
2413 might throw as well. */
2414 && !stmt_can_throw_internal (stmt
))
2416 tree lhs
= gimple_get_lhs (stmt
);
2417 /* If LHS is literally a base of the access we are done. */
2420 tree base
= ref
->ref
;
2421 if (handled_component_p (base
))
2423 tree saved_lhs0
= NULL_TREE
;
2424 if (handled_component_p (lhs
))
2426 saved_lhs0
= TREE_OPERAND (lhs
, 0);
2427 TREE_OPERAND (lhs
, 0) = integer_zero_node
;
2431 /* Just compare the outermost handled component, if
2432 they are equal we have found a possible common
2434 tree saved_base0
= TREE_OPERAND (base
, 0);
2435 TREE_OPERAND (base
, 0) = integer_zero_node
;
2436 bool res
= operand_equal_p (lhs
, base
, 0);
2437 TREE_OPERAND (base
, 0) = saved_base0
;
2440 /* Otherwise drop handled components of the access. */
2443 while (handled_component_p (base
));
2445 TREE_OPERAND (lhs
, 0) = saved_lhs0
;
2447 /* Finally check if the lhs has the same address and size as the
2448 base candidate of the access. */
2450 || (((TYPE_SIZE (TREE_TYPE (lhs
))
2451 == TYPE_SIZE (TREE_TYPE (base
)))
2452 || (TYPE_SIZE (TREE_TYPE (lhs
))
2453 && TYPE_SIZE (TREE_TYPE (base
))
2454 && operand_equal_p (TYPE_SIZE (TREE_TYPE (lhs
)),
2455 TYPE_SIZE (TREE_TYPE (base
)), 0)))
2456 && operand_equal_p (lhs
, base
, OEP_ADDRESS_OF
)))
2460 /* Now look for non-literal equal bases with the restriction of
2461 handling constant offset and size. */
2462 /* For a must-alias check we need to be able to constrain
2463 the access properly. */
2464 if (ref
->max_size
== -1)
2466 HOST_WIDE_INT size
, offset
, max_size
, ref_offset
= ref
->offset
;
2469 = get_ref_base_and_extent (lhs
, &offset
, &size
, &max_size
, &reverse
);
2470 /* We can get MEM[symbol: sZ, index: D.8862_1] here,
2471 so base == ref->base does not always hold. */
2472 if (base
!= ref
->base
)
2474 /* Try using points-to info. */
2475 if (same_addr_size_stores_p (base
, offset
, size
, max_size
, ref
->base
,
2476 ref
->offset
, ref
->size
, ref
->max_size
))
2479 /* If both base and ref->base are MEM_REFs, only compare the
2480 first operand, and if the second operand isn't equal constant,
2481 try to add the offsets into offset and ref_offset. */
2482 if (TREE_CODE (base
) == MEM_REF
&& TREE_CODE (ref
->base
) == MEM_REF
2483 && TREE_OPERAND (base
, 0) == TREE_OPERAND (ref
->base
, 0))
2485 if (!tree_int_cst_equal (TREE_OPERAND (base
, 1),
2486 TREE_OPERAND (ref
->base
, 1)))
2488 offset_int off1
= mem_ref_offset (base
);
2489 off1
<<= LOG2_BITS_PER_UNIT
;
2491 offset_int off2
= mem_ref_offset (ref
->base
);
2492 off2
<<= LOG2_BITS_PER_UNIT
;
2494 if (wi::fits_shwi_p (off1
) && wi::fits_shwi_p (off2
))
2496 offset
= off1
.to_shwi ();
2497 ref_offset
= off2
.to_shwi ();
2506 /* For a must-alias check we need to be able to constrain
2507 the access properly. */
2508 if (size
!= -1 && size
== max_size
)
2510 if (offset
<= ref_offset
2511 && offset
+ size
>= ref_offset
+ ref
->max_size
)
2516 if (is_gimple_call (stmt
))
2518 tree callee
= gimple_call_fndecl (stmt
);
2519 if (callee
!= NULL_TREE
2520 && gimple_call_builtin_p (stmt
, BUILT_IN_NORMAL
))
2521 switch (DECL_FUNCTION_CODE (callee
))
2525 tree ptr
= gimple_call_arg (stmt
, 0);
2526 tree base
= ao_ref_base (ref
);
2527 if (base
&& TREE_CODE (base
) == MEM_REF
2528 && TREE_OPERAND (base
, 0) == ptr
)
2533 case BUILT_IN_MEMCPY
:
2534 case BUILT_IN_MEMPCPY
:
2535 case BUILT_IN_MEMMOVE
:
2536 case BUILT_IN_MEMSET
:
2537 case BUILT_IN_MEMCPY_CHK
:
2538 case BUILT_IN_MEMPCPY_CHK
:
2539 case BUILT_IN_MEMMOVE_CHK
:
2540 case BUILT_IN_MEMSET_CHK
:
2541 case BUILT_IN_STRNCPY
:
2542 case BUILT_IN_STPNCPY
:
2544 /* For a must-alias check we need to be able to constrain
2545 the access properly. */
2546 if (ref
->max_size
== -1)
2548 tree dest
= gimple_call_arg (stmt
, 0);
2549 tree len
= gimple_call_arg (stmt
, 2);
2550 if (!tree_fits_shwi_p (len
))
2552 tree rbase
= ref
->base
;
2553 offset_int roffset
= ref
->offset
;
2555 ao_ref_init_from_ptr_and_size (&dref
, dest
, len
);
2556 tree base
= ao_ref_base (&dref
);
2557 offset_int offset
= dref
.offset
;
2558 if (!base
|| dref
.size
== -1)
2560 if (TREE_CODE (base
) == MEM_REF
)
2562 if (TREE_CODE (rbase
) != MEM_REF
)
2564 // Compare pointers.
2565 offset
+= mem_ref_offset (base
) << LOG2_BITS_PER_UNIT
;
2566 roffset
+= mem_ref_offset (rbase
) << LOG2_BITS_PER_UNIT
;
2567 base
= TREE_OPERAND (base
, 0);
2568 rbase
= TREE_OPERAND (rbase
, 0);
2571 && offset
<= roffset
2572 && (roffset
+ ref
->max_size
2573 <= offset
+ (wi::to_offset (len
) << LOG2_BITS_PER_UNIT
)))
2578 case BUILT_IN_VA_END
:
2580 tree ptr
= gimple_call_arg (stmt
, 0);
2581 if (TREE_CODE (ptr
) == ADDR_EXPR
)
2583 tree base
= ao_ref_base (ref
);
2584 if (TREE_OPERAND (ptr
, 0) == base
)
2597 stmt_kills_ref_p (gimple
*stmt
, tree ref
)
2600 ao_ref_init (&r
, ref
);
2601 return stmt_kills_ref_p (stmt
, &r
);
2605 /* Walk the virtual use-def chain of VUSE until hitting the virtual operand
2606 TARGET or a statement clobbering the memory reference REF in which
2607 case false is returned. The walk starts with VUSE, one argument of PHI. */
2610 maybe_skip_until (gimple
*phi
, tree target
, ao_ref
*ref
,
2611 tree vuse
, unsigned int *cnt
, bitmap
*visited
,
2612 bool abort_on_visited
,
2613 void *(*translate
)(ao_ref
*, tree
, void *, bool *),
2616 basic_block bb
= gimple_bb (phi
);
2619 *visited
= BITMAP_ALLOC (NULL
);
2621 bitmap_set_bit (*visited
, SSA_NAME_VERSION (PHI_RESULT (phi
)));
2623 /* Walk until we hit the target. */
2624 while (vuse
!= target
)
2626 gimple
*def_stmt
= SSA_NAME_DEF_STMT (vuse
);
2627 /* Recurse for PHI nodes. */
2628 if (gimple_code (def_stmt
) == GIMPLE_PHI
)
2630 /* An already visited PHI node ends the walk successfully. */
2631 if (bitmap_bit_p (*visited
, SSA_NAME_VERSION (PHI_RESULT (def_stmt
))))
2632 return !abort_on_visited
;
2633 vuse
= get_continuation_for_phi (def_stmt
, ref
, cnt
,
2634 visited
, abort_on_visited
,
2640 else if (gimple_nop_p (def_stmt
))
2644 /* A clobbering statement or the end of the IL ends it failing. */
2646 if (stmt_may_clobber_ref_p_1 (def_stmt
, ref
))
2648 bool disambiguate_only
= true;
2650 && (*translate
) (ref
, vuse
, data
, &disambiguate_only
) == NULL
)
2656 /* If we reach a new basic-block see if we already skipped it
2657 in a previous walk that ended successfully. */
2658 if (gimple_bb (def_stmt
) != bb
)
2660 if (!bitmap_set_bit (*visited
, SSA_NAME_VERSION (vuse
)))
2661 return !abort_on_visited
;
2662 bb
= gimple_bb (def_stmt
);
2664 vuse
= gimple_vuse (def_stmt
);
2669 /* For two PHI arguments ARG0 and ARG1 try to skip non-aliasing code
2670 until we hit the phi argument definition that dominates the other one.
2671 Return that, or NULL_TREE if there is no such definition. */
2674 get_continuation_for_phi_1 (gimple
*phi
, tree arg0
, tree arg1
,
2675 ao_ref
*ref
, unsigned int *cnt
,
2676 bitmap
*visited
, bool abort_on_visited
,
2677 void *(*translate
)(ao_ref
*, tree
, void *, bool *),
2680 gimple
*def0
= SSA_NAME_DEF_STMT (arg0
);
2681 gimple
*def1
= SSA_NAME_DEF_STMT (arg1
);
2686 else if (gimple_nop_p (def0
)
2687 || (!gimple_nop_p (def1
)
2688 && dominated_by_p (CDI_DOMINATORS
,
2689 gimple_bb (def1
), gimple_bb (def0
))))
2691 if (maybe_skip_until (phi
, arg0
, ref
, arg1
, cnt
,
2692 visited
, abort_on_visited
, translate
, data
))
2695 else if (gimple_nop_p (def1
)
2696 || dominated_by_p (CDI_DOMINATORS
,
2697 gimple_bb (def0
), gimple_bb (def1
)))
2699 if (maybe_skip_until (phi
, arg1
, ref
, arg0
, cnt
,
2700 visited
, abort_on_visited
, translate
, data
))
2703 /* Special case of a diamond:
2705 goto (cond) ? L1 : L2
2706 L1: store1 = ... #MEM_2 = vuse(MEM_1)
2708 L2: store2 = ... #MEM_3 = vuse(MEM_1)
2709 L3: MEM_4 = PHI<MEM_2, MEM_3>
2710 We were called with the PHI at L3, MEM_2 and MEM_3 don't
2711 dominate each other, but still we can easily skip this PHI node
2712 if we recognize that the vuse MEM operand is the same for both,
2713 and that we can skip both statements (they don't clobber us).
2714 This is still linear. Don't use maybe_skip_until, that might
2715 potentially be slow. */
2716 else if ((common_vuse
= gimple_vuse (def0
))
2717 && common_vuse
== gimple_vuse (def1
))
2719 bool disambiguate_only
= true;
2721 if ((!stmt_may_clobber_ref_p_1 (def0
, ref
)
2723 && (*translate
) (ref
, arg0
, data
, &disambiguate_only
) == NULL
))
2724 && (!stmt_may_clobber_ref_p_1 (def1
, ref
)
2726 && (*translate
) (ref
, arg1
, data
, &disambiguate_only
) == NULL
)))
2734 /* Starting from a PHI node for the virtual operand of the memory reference
2735 REF find a continuation virtual operand that allows to continue walking
2736 statements dominating PHI skipping only statements that cannot possibly
2737 clobber REF. Increments *CNT for each alias disambiguation done.
2738 Returns NULL_TREE if no suitable virtual operand can be found. */
2741 get_continuation_for_phi (gimple
*phi
, ao_ref
*ref
,
2742 unsigned int *cnt
, bitmap
*visited
,
2743 bool abort_on_visited
,
2744 void *(*translate
)(ao_ref
*, tree
, void *, bool *),
2747 unsigned nargs
= gimple_phi_num_args (phi
);
2749 /* Through a single-argument PHI we can simply look through. */
2751 return PHI_ARG_DEF (phi
, 0);
2753 /* For two or more arguments try to pairwise skip non-aliasing code
2754 until we hit the phi argument definition that dominates the other one. */
2755 else if (nargs
>= 2)
2760 /* Find a candidate for the virtual operand which definition
2761 dominates those of all others. */
2762 arg0
= PHI_ARG_DEF (phi
, 0);
2763 if (!SSA_NAME_IS_DEFAULT_DEF (arg0
))
2764 for (i
= 1; i
< nargs
; ++i
)
2766 arg1
= PHI_ARG_DEF (phi
, i
);
2767 if (SSA_NAME_IS_DEFAULT_DEF (arg1
))
2772 if (dominated_by_p (CDI_DOMINATORS
,
2773 gimple_bb (SSA_NAME_DEF_STMT (arg0
)),
2774 gimple_bb (SSA_NAME_DEF_STMT (arg1
))))
2778 /* Then pairwise reduce against the found candidate. */
2779 for (i
= 0; i
< nargs
; ++i
)
2781 arg1
= PHI_ARG_DEF (phi
, i
);
2782 arg0
= get_continuation_for_phi_1 (phi
, arg0
, arg1
, ref
,
2783 cnt
, visited
, abort_on_visited
,
2795 /* Based on the memory reference REF and its virtual use VUSE call
2796 WALKER for each virtual use that is equivalent to VUSE, including VUSE
2797 itself. That is, for each virtual use for which its defining statement
2798 does not clobber REF.
2800 WALKER is called with REF, the current virtual use and DATA. If
2801 WALKER returns non-NULL the walk stops and its result is returned.
2802 At the end of a non-successful walk NULL is returned.
2804 TRANSLATE if non-NULL is called with a pointer to REF, the virtual
2805 use which definition is a statement that may clobber REF and DATA.
2806 If TRANSLATE returns (void *)-1 the walk stops and NULL is returned.
2807 If TRANSLATE returns non-NULL the walk stops and its result is returned.
2808 If TRANSLATE returns NULL the walk continues and TRANSLATE is supposed
2809 to adjust REF and *DATA to make that valid.
2811 VALUEIZE if non-NULL is called with the next VUSE that is considered
2812 and return value is substituted for that. This can be used to
2813 implement optimistic value-numbering for example. Note that the
2814 VUSE argument is assumed to be valueized already.
2816 TODO: Cache the vector of equivalent vuses per ref, vuse pair. */
2819 walk_non_aliased_vuses (ao_ref
*ref
, tree vuse
,
2820 void *(*walker
)(ao_ref
*, tree
, unsigned int, void *),
2821 void *(*translate
)(ao_ref
*, tree
, void *, bool *),
2822 tree (*valueize
)(tree
),
2825 bitmap visited
= NULL
;
2827 unsigned int cnt
= 0;
2828 bool translated
= false;
2830 timevar_push (TV_ALIAS_STMT_WALK
);
2836 /* ??? Do we want to account this to TV_ALIAS_STMT_WALK? */
2837 res
= (*walker
) (ref
, vuse
, cnt
, data
);
2839 if (res
== (void *)-1)
2844 /* Lookup succeeded. */
2845 else if (res
!= NULL
)
2849 vuse
= valueize (vuse
);
2850 def_stmt
= SSA_NAME_DEF_STMT (vuse
);
2851 if (gimple_nop_p (def_stmt
))
2853 else if (gimple_code (def_stmt
) == GIMPLE_PHI
)
2854 vuse
= get_continuation_for_phi (def_stmt
, ref
, &cnt
,
2855 &visited
, translated
, translate
, data
);
2859 if (stmt_may_clobber_ref_p_1 (def_stmt
, ref
))
2863 bool disambiguate_only
= false;
2864 res
= (*translate
) (ref
, vuse
, data
, &disambiguate_only
);
2865 /* Failed lookup and translation. */
2866 if (res
== (void *)-1)
2871 /* Lookup succeeded. */
2872 else if (res
!= NULL
)
2874 /* Translation succeeded, continue walking. */
2875 translated
= translated
|| !disambiguate_only
;
2877 vuse
= gimple_vuse (def_stmt
);
2883 BITMAP_FREE (visited
);
2885 timevar_pop (TV_ALIAS_STMT_WALK
);
2891 /* Based on the memory reference REF call WALKER for each vdef which
2892 defining statement may clobber REF, starting with VDEF. If REF
2893 is NULL_TREE, each defining statement is visited.
2895 WALKER is called with REF, the current vdef and DATA. If WALKER
2896 returns true the walk is stopped, otherwise it continues.
2898 If function entry is reached, FUNCTION_ENTRY_REACHED is set to true.
2899 The pointer may be NULL and then we do not track this information.
2901 At PHI nodes walk_aliased_vdefs forks into one walk for reach
2902 PHI argument (but only one walk continues on merge points), the
2903 return value is true if any of the walks was successful.
2905 The function returns the number of statements walked or -1 if
2906 LIMIT stmts were walked and the walk was aborted at this point.
2907 If LIMIT is zero the walk is not aborted. */
2910 walk_aliased_vdefs_1 (ao_ref
*ref
, tree vdef
,
2911 bool (*walker
)(ao_ref
*, tree
, void *), void *data
,
2912 bitmap
*visited
, unsigned int cnt
,
2913 bool *function_entry_reached
, unsigned limit
)
2917 gimple
*def_stmt
= SSA_NAME_DEF_STMT (vdef
);
2920 && !bitmap_set_bit (*visited
, SSA_NAME_VERSION (vdef
)))
2923 if (gimple_nop_p (def_stmt
))
2925 if (function_entry_reached
)
2926 *function_entry_reached
= true;
2929 else if (gimple_code (def_stmt
) == GIMPLE_PHI
)
2933 *visited
= BITMAP_ALLOC (NULL
);
2934 for (i
= 0; i
< gimple_phi_num_args (def_stmt
); ++i
)
2936 int res
= walk_aliased_vdefs_1 (ref
,
2937 gimple_phi_arg_def (def_stmt
, i
),
2938 walker
, data
, visited
, cnt
,
2939 function_entry_reached
, limit
);
2947 /* ??? Do we want to account this to TV_ALIAS_STMT_WALK? */
2952 || stmt_may_clobber_ref_p_1 (def_stmt
, ref
))
2953 && (*walker
) (ref
, vdef
, data
))
2956 vdef
= gimple_vuse (def_stmt
);
2962 walk_aliased_vdefs (ao_ref
*ref
, tree vdef
,
2963 bool (*walker
)(ao_ref
*, tree
, void *), void *data
,
2965 bool *function_entry_reached
, unsigned int limit
)
2967 bitmap local_visited
= NULL
;
2970 timevar_push (TV_ALIAS_STMT_WALK
);
2972 if (function_entry_reached
)
2973 *function_entry_reached
= false;
2975 ret
= walk_aliased_vdefs_1 (ref
, vdef
, walker
, data
,
2976 visited
? visited
: &local_visited
, 0,
2977 function_entry_reached
, limit
);
2979 BITMAP_FREE (local_visited
);
2981 timevar_pop (TV_ALIAS_STMT_WALK
);