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re PR tree-optimization/79547 (duplicate strlen calls with same argument not folded) 

2017-04-21  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/79547
	* tree-ssa-structalias.c (find_func_aliases_for_builtin_call):
	Handle strlen, strcmp, strncmp, strcasecmp, strncasecmp, memcmp,
	bcmp, strspn, strcspn, __builtin_object_size and __builtin_constant_p
	without any constraints.

	* gcc.dg/tree-ssa/strlen-2.c: New testcase.

From-SVN: r247062
This commit is contained in:
Richard Biener 2017-04-21 12:47:02 +00:00 committed by Richard Biener
parent bb1bc604a8
commit 2fd30fbe0d
4 changed files with 62 additions and 0 deletions
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8
gcc/ChangeLog
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@ -1,3 +1,11 @@
2017-04-21 Richard Biener <rguenther@suse.de>
PR tree-optimization/79547
* tree-ssa-structalias.c (find_func_aliases_for_builtin_call):
Handle strlen, strcmp, strncmp, strcasecmp, strncasecmp, memcmp,
bcmp, strspn, strcspn, __builtin_object_size and __builtin_constant_p
without any constraints.
2017-04-21 Richard Biener <rguenther@suse.de>
PR tree-optimization/78847

5
gcc/testsuite/ChangeLog
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@ -1,3 +1,8 @@
2017-04-21 Richard Biener <rguenther@suse.de>
PR tree-optimization/79547
* gcc.dg/tree-ssa/strlen-2.c: New testcase.
2017-04-21 Richard Biener <rguenther@suse.de>
PR tree-optimization/78847

15
gcc/testsuite/gcc.dg/tree-ssa/strlen-2.c Normal file
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@ -0,0 +1,15 @@
/* { dg-do compile } */
/* { dg-options "-O2 -fdump-tree-strlen" } */
void f (unsigned);
void f3 (void)
{
char s[] = "1234";
f (__builtin_strlen (s));
f (__builtin_strlen (s));
f (__builtin_strlen (s));
}
/* { dg-final { scan-tree-dump-times "strlen" 0 "strlen" } } */

34
gcc/tree-ssa-structalias.c
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@ -4474,6 +4474,40 @@ find_func_aliases_for_builtin_call (struct function *fn, gcall *t)
process_all_all_constraints (lhsc, rhsc);
}
return true;
/* Pure functions that return something not based on any object and
that use the memory pointed to by their arguments (but not
transitively). */
case BUILT_IN_STRCMP:
case BUILT_IN_STRNCMP:
case BUILT_IN_STRCASECMP:
case BUILT_IN_STRNCASECMP:
case BUILT_IN_MEMCMP:
case BUILT_IN_BCMP:
case BUILT_IN_STRSPN:
case BUILT_IN_STRCSPN:
{
varinfo_t uses = get_call_use_vi (t);
make_any_offset_constraints (uses);
make_constraint_to (uses->id, gimple_call_arg (t, 0));
make_constraint_to (uses->id, gimple_call_arg (t, 1));
/* No constraints are necessary for the return value. */
return true;
}
case BUILT_IN_STRLEN:
{
varinfo_t uses = get_call_use_vi (t);
make_any_offset_constraints (uses);
make_constraint_to (uses->id, gimple_call_arg (t, 0));
/* No constraints are necessary for the return value. */
return true;
}
case BUILT_IN_OBJECT_SIZE:
case BUILT_IN_CONSTANT_P:
{
/* No constraints are necessary for the return value or the
arguments. */
return true;
}
/* Trampolines are special - they set up passing the static
frame. */
case BUILT_IN_INIT_TRAMPOLINE: