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* [Bug tree-optimization/51683] New: [4.7 Regression] __builtin_memcpy etc. with constant first argument optimized away by ccp
@ 2011-12-27 11:19 jakub at gcc dot gnu.org
2011-12-27 11:33 ` [Bug tree-optimization/51683] " jakub at gcc dot gnu.org
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: jakub at gcc dot gnu.org @ 2011-12-27 11:19 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51683
Bug #: 51683
Summary: [4.7 Regression] __builtin_memcpy etc. with constant
first argument optimized away by ccp
Classification: Unclassified
Product: gcc
Version: 4.7.0
Status: UNCONFIRMED
Keywords: wrong-code
Severity: normal
Priority: P3
Component: tree-optimization
AssignedTo: jakub@gcc.gnu.org
ReportedBy: jakub@gcc.gnu.org
static inline void *
bar (void *p, void *q, int r)
{
return __builtin_memcpy (p, q, r);
}
void *
foo (void *p)
{
return bar ((void *) 0x12345000, p, 256);
}
at -O2 starting with http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=175290
is optimized away. While the return value from memcpy is known to be constant
and we know that constant, we ignore the other side-effects of the call.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/51683] [4.7 Regression] __builtin_memcpy etc. with constant first argument optimized away by ccp
2011-12-27 11:19 [Bug tree-optimization/51683] New: [4.7 Regression] __builtin_memcpy etc. with constant first argument optimized away by ccp jakub at gcc dot gnu.org
@ 2011-12-27 11:33 ` jakub at gcc dot gnu.org
2011-12-27 11:37 ` jakub at gcc dot gnu.org
2011-12-31 23:57 ` jakub at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: jakub at gcc dot gnu.org @ 2011-12-27 11:33 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51683
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |ASSIGNED
Last reconfirmed| |2011-12-27
Target Milestone|--- |4.7.0
Ever Confirmed|0 |1
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/51683] [4.7 Regression] __builtin_memcpy etc. with constant first argument optimized away by ccp
2011-12-27 11:19 [Bug tree-optimization/51683] New: [4.7 Regression] __builtin_memcpy etc. with constant first argument optimized away by ccp jakub at gcc dot gnu.org
2011-12-27 11:33 ` [Bug tree-optimization/51683] " jakub at gcc dot gnu.org
@ 2011-12-27 11:37 ` jakub at gcc dot gnu.org
2011-12-31 23:57 ` jakub at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: jakub at gcc dot gnu.org @ 2011-12-27 11:37 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51683
--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-12-27 11:33:01 UTC ---
Created attachment 26188
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=26188
gcc47-pr51683.patch
Untested fix.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/51683] [4.7 Regression] __builtin_memcpy etc. with constant first argument optimized away by ccp
2011-12-27 11:19 [Bug tree-optimization/51683] New: [4.7 Regression] __builtin_memcpy etc. with constant first argument optimized away by ccp jakub at gcc dot gnu.org
2011-12-27 11:33 ` [Bug tree-optimization/51683] " jakub at gcc dot gnu.org
2011-12-27 11:37 ` jakub at gcc dot gnu.org
@ 2011-12-31 23:57 ` jakub at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: jakub at gcc dot gnu.org @ 2011-12-31 23:57 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51683
--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-12-31 23:54:00 UTC ---
Author: jakub
Date: Sat Dec 31 23:53:57 2011
New Revision: 182761
URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=182761
Log:
PR tree-optimization/51683
* tree-ssa-propagate.c (substitute_and_fold): Don't optimize away
calls with side-effects.
* tree-ssa-ccp.c (ccp_fold_stmt): Likewise.
* gcc.dg/pr51683.c: New test.
Added:
trunk/gcc/testsuite/gcc.dg/pr51683.c
Modified:
trunk/gcc/ChangeLog
trunk/gcc/testsuite/ChangeLog
trunk/gcc/tree-ssa-ccp.c
trunk/gcc/tree-ssa-propagate.c
^ permalink raw reply [flat|nested] 4+ messages in thread
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2011-12-27 11:19 [Bug tree-optimization/51683] New: [4.7 Regression] __builtin_memcpy etc. with constant first argument optimized away by ccp jakub at gcc dot gnu.org
2011-12-27 11:33 ` [Bug tree-optimization/51683] " jakub at gcc dot gnu.org
2011-12-27 11:37 ` jakub at gcc dot gnu.org
2011-12-31 23:57 ` jakub at gcc dot gnu.org
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