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* [Bug tree-optimization/52028] New: [4.7 Regression] wrong code with -O2 -ftree-loop-distribution
@ 2012-01-28 16:40 zsojka at seznam dot cz
2012-01-28 16:48 ` [Bug tree-optimization/52028] " dominiq at lps dot ens.fr
` (6 more replies)
0 siblings, 7 replies; 8+ messages in thread
From: zsojka at seznam dot cz @ 2012-01-28 16:40 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52028
Bug #: 52028
Summary: [4.7 Regression] wrong code with -O2
-ftree-loop-distribution
Classification: Unclassified
Product: gcc
Version: 4.7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
AssignedTo: unassigned@gcc.gnu.org
ReportedBy: zsojka@seznam.cz
Host: x86_64-pc-linux-gnu
Target: x86_64-pc-linux-gnu
Created attachment 26489
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=26489
reduced testcase
Compiler output:
$ gcc -O2 -ftree-loop-distribution testcase4.c
$ valgrind -q ./a.out
==32144== Conditional jump or move depends on uninitialised value(s)
==32144== at 0x4C2D333: bcmp (in
/usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==32144== by 0x4005F4: main (in /home/smatz/gcc-bug/1063/a.out)
==32144==
==32144== Conditional jump or move depends on uninitialised value(s)
==32144== at 0x4005F7: main (in /home/smatz/gcc-bug/1063/a.out)
==32144==
Aborted
Tested revisions:
r183666 - fail
r180540 - fail
r178498 - fail
4.6 r180325 - OK
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug tree-optimization/52028] [4.7 Regression] wrong code with -O2 -ftree-loop-distribution
2012-01-28 16:40 [Bug tree-optimization/52028] New: [4.7 Regression] wrong code with -O2 -ftree-loop-distribution zsojka at seznam dot cz
@ 2012-01-28 16:48 ` dominiq at lps dot ens.fr
2012-01-28 16:52 ` jakub at gcc dot gnu.org
` (5 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: dominiq at lps dot ens.fr @ 2012-01-28 16:48 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52028
Dominique d'Humieres <dominiq at lps dot ens.fr> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2012-01-28
Ever Confirmed|0 |1
--- Comment #1 from Dominique d'Humieres <dominiq at lps dot ens.fr> 2012-01-28 15:12:13 UTC ---
Reduced range:
revision 177649 - OK,
revision 178509 - fail.
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug tree-optimization/52028] [4.7 Regression] wrong code with -O2 -ftree-loop-distribution
2012-01-28 16:40 [Bug tree-optimization/52028] New: [4.7 Regression] wrong code with -O2 -ftree-loop-distribution zsojka at seznam dot cz
2012-01-28 16:48 ` [Bug tree-optimization/52028] " dominiq at lps dot ens.fr
@ 2012-01-28 16:52 ` jakub at gcc dot gnu.org
2012-01-30 10:51 ` rguenth at gcc dot gnu.org
` (4 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: jakub at gcc dot gnu.org @ 2012-01-28 16:52 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52028
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |jakub at gcc dot gnu.org
Target Milestone|--- |4.7.0
--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-01-28 16:39:47 UTC ---
Started with http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=178028
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug tree-optimization/52028] [4.7 Regression] wrong code with -O2 -ftree-loop-distribution
2012-01-28 16:40 [Bug tree-optimization/52028] New: [4.7 Regression] wrong code with -O2 -ftree-loop-distribution zsojka at seznam dot cz
2012-01-28 16:48 ` [Bug tree-optimization/52028] " dominiq at lps dot ens.fr
2012-01-28 16:52 ` jakub at gcc dot gnu.org
@ 2012-01-30 10:51 ` rguenth at gcc dot gnu.org
2012-01-30 14:13 ` rguenth at gcc dot gnu.org
` (3 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: rguenth at gcc dot gnu.org @ 2012-01-30 10:51 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52028
Richard Guenther <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |ASSIGNED
AssignedTo|unassigned at gcc dot |rguenth at gcc dot gnu.org
|gnu.org |
--- Comment #3 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-01-30 09:37:53 UTC ---
Mine then.
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug tree-optimization/52028] [4.7 Regression] wrong code with -O2 -ftree-loop-distribution
2012-01-28 16:40 [Bug tree-optimization/52028] New: [4.7 Regression] wrong code with -O2 -ftree-loop-distribution zsojka at seznam dot cz
` (2 preceding siblings ...)
2012-01-30 10:51 ` rguenth at gcc dot gnu.org
@ 2012-01-30 14:13 ` rguenth at gcc dot gnu.org
2012-01-30 14:28 ` rguenth at gcc dot gnu.org
` (2 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: rguenth at gcc dot gnu.org @ 2012-01-30 14:13 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52028
--- Comment #4 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-01-30 13:57:30 UTC ---
loop distribution splits the
for (;;)
{
...
if (K != k)
break;
K += 16;
}
loop into three portions, the first writing to K[0..13], the next
writing to K[14] and the last writing to K[15]. All of which is
reasonable at a first glance. But then the first loop is discarded
completely CDDCE2, so something is wrong.
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug tree-optimization/52028] [4.7 Regression] wrong code with -O2 -ftree-loop-distribution
2012-01-28 16:40 [Bug tree-optimization/52028] New: [4.7 Regression] wrong code with -O2 -ftree-loop-distribution zsojka at seznam dot cz
` (3 preceding siblings ...)
2012-01-30 14:13 ` rguenth at gcc dot gnu.org
@ 2012-01-30 14:28 ` rguenth at gcc dot gnu.org
2012-01-30 16:17 ` rguenth at gcc dot gnu.org
2012-01-30 16:39 ` rguenth at gcc dot gnu.org
6 siblings, 0 replies; 8+ messages in thread
From: rguenth at gcc dot gnu.org @ 2012-01-30 14:28 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52028
--- Comment #5 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-01-30 14:16:51 UTC ---
Virtual SSA form is corrupt (and we don't detect that - bah).
<bb 3>:
# .MEM_723 = PHI <.MEM_666(3), .MEM_661(D)(2)>
# ivtmp.297_722 = PHI <ivtmp.297_648(3), ivtmp.297_1354(2)>
D.2523_1353 = (void *) ivtmp.297_722;
# .MEM_666 = VDEF <.MEM_723>
MEM[base: D.2523_1353, offset: 0B] = 0;
ivtmp.297_648 = ivtmp.297_722 + 4;
if (ivtmp.297_648 != D.2525_653)
goto <bb 3>;
else
goto <bb 4>;
<bb 4>:
...
<bb 5>:
# K_1035 = PHI <&MEM[(void *)&k + 64B](5), &k(4)>
# .MEM_703 = PHI <.MEM_562(5), .MEM_666(4)>
...
# .MEM_562 = VDEF <.MEM_561>
MEM[(unsigned int *)K_1035 + 52B] = pretmp.262_1186;
D.1989_556 = D.1916_553 + 512;
D.1990_563 = D.1989_556 * 4;
D.1991_566 = &CAST_S_table + D.1990_563;
# VUSE <.MEM_562>
D.1992_567 = *D.1991_566;
if (&k != K_1035)
goto <bb 6>;
else
goto <bb 5>;
<bb 6>:
K_1352 = &k;
X$0_719 = 0;
<bb 7>:
# K_1147 = PHI <&k(6), &MEM[(void *)&k + 64B](7)>
# .MEM_1141 = PHI <.MEM_666(6), .MEM_1343(7)>
...
We have overlapping life-ranges for .MEM_666 and .MEM_562 (at least).
I have a patch.
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug tree-optimization/52028] [4.7 Regression] wrong code with -O2 -ftree-loop-distribution
2012-01-28 16:40 [Bug tree-optimization/52028] New: [4.7 Regression] wrong code with -O2 -ftree-loop-distribution zsojka at seznam dot cz
` (4 preceding siblings ...)
2012-01-30 14:28 ` rguenth at gcc dot gnu.org
@ 2012-01-30 16:17 ` rguenth at gcc dot gnu.org
2012-01-30 16:39 ` rguenth at gcc dot gnu.org
6 siblings, 0 replies; 8+ messages in thread
From: rguenth at gcc dot gnu.org @ 2012-01-30 16:17 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52028
Richard Guenther <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|ASSIGNED |RESOLVED
Resolution| |FIXED
--- Comment #7 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-01-30 15:52:02 UTC ---
Fixed.
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug tree-optimization/52028] [4.7 Regression] wrong code with -O2 -ftree-loop-distribution
2012-01-28 16:40 [Bug tree-optimization/52028] New: [4.7 Regression] wrong code with -O2 -ftree-loop-distribution zsojka at seznam dot cz
` (5 preceding siblings ...)
2012-01-30 16:17 ` rguenth at gcc dot gnu.org
@ 2012-01-30 16:39 ` rguenth at gcc dot gnu.org
6 siblings, 0 replies; 8+ messages in thread
From: rguenth at gcc dot gnu.org @ 2012-01-30 16:39 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52028
--- Comment #6 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-01-30 15:51:34 UTC ---
Author: rguenth
Date: Mon Jan 30 15:51:23 2012
New Revision: 183730
URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=183730
Log:
2012-01-30 Richard Guenther <rguenther@suse.de>
PR tree-optimization/52028
* tree-loop-distribution.c (ldist_gen): Properly update
virtual SSA form.
* gcc.dg/torture/pr52028.c: New testcase.
* gfortran.dg/ldist-pr45199.f: Adjust.
* gcc.dg/tree-ssa/ldist-16.c: Likewise.
* gcc.dg/tree-ssa/ldist-17.c: Likewise.
* gcc.dg/tree-ssa/ldist-pr45948.c: Likewise.
Added:
trunk/gcc/testsuite/gcc.dg/torture/pr52028.c
Modified:
trunk/gcc/ChangeLog
trunk/gcc/testsuite/ChangeLog
trunk/gcc/testsuite/gcc.dg/tree-ssa/ldist-16.c
trunk/gcc/testsuite/gcc.dg/tree-ssa/ldist-17.c
trunk/gcc/testsuite/gcc.dg/tree-ssa/ldist-pr45948.c
trunk/gcc/testsuite/gfortran.dg/ldist-pr45199.f
trunk/gcc/tree-loop-distribution.c
^ permalink raw reply [flat|nested] 8+ messages in thread
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2012-01-28 16:40 [Bug tree-optimization/52028] New: [4.7 Regression] wrong code with -O2 -ftree-loop-distribution zsojka at seznam dot cz
2012-01-28 16:48 ` [Bug tree-optimization/52028] " dominiq at lps dot ens.fr
2012-01-28 16:52 ` jakub at gcc dot gnu.org
2012-01-30 10:51 ` rguenth at gcc dot gnu.org
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