* [Bug tree-optimization/55005] [4.8 Regression] gcc.c-torture/execute/loop-3.c FAILs with -fPIC
2012-10-21 5:25 [Bug tree-optimization/55005] New: [4.8 Regression] gcc.c-torture/execute/loop-3.c FAILs with -fPIC zsojka at seznam dot cz
@ 2012-10-21 12:15 ` zsojka at seznam dot cz
2012-10-21 16:10 ` mpolacek at gcc dot gnu.org
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From: zsojka at seznam dot cz @ 2012-10-21 12:15 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55005
--- Comment #1 from Zdenek Sojka <zsojka at seznam dot cz> 2012-10-21 12:14:59 UTC ---
This isn't the only testcase that started failing recently.
One interesting flag combination:
$ gcc -O2 -fno-tree-ccp -fno-tree-copy-prop -fno-tree-dce testcase.c && ./a.out
Segmentation fault
In this case, the body of main() isn't generated at all, so the code runs away
immediatelly after jumping to main().
main:
.LFB2:
.cfi_startproc
.cfi_endproc
.LFE2:
.size main, .-main
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2012-10-21 5:25 [Bug tree-optimization/55005] New: [4.8 Regression] gcc.c-torture/execute/loop-3.c FAILs with -fPIC zsojka at seznam dot cz
2012-10-21 12:15 ` [Bug tree-optimization/55005] " zsojka at seznam dot cz
@ 2012-10-21 16:10 ` mpolacek at gcc dot gnu.org
2012-10-21 16:15 ` zsojka at seznam dot cz
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From: mpolacek at gcc dot gnu.org @ 2012-10-21 16:10 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55005
Marek Polacek <mpolacek at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2012-10-21
CC| |mpolacek at gcc dot gnu.org
Ever Confirmed|0 |1
--- Comment #2 from Marek Polacek <mpolacek at gcc dot gnu.org> 2012-10-21 16:10:30 UTC ---
Started with http://gcc.gnu.org/viewcvs?view=revision&revision=192538
^ permalink raw reply [flat|nested] 9+ messages in thread* [Bug tree-optimization/55005] [4.8 Regression] gcc.c-torture/execute/loop-3.c FAILs with -fPIC
2012-10-21 5:25 [Bug tree-optimization/55005] New: [4.8 Regression] gcc.c-torture/execute/loop-3.c FAILs with -fPIC zsojka at seznam dot cz
2012-10-21 12:15 ` [Bug tree-optimization/55005] " zsojka at seznam dot cz
2012-10-21 16:10 ` mpolacek at gcc dot gnu.org
@ 2012-10-21 16:15 ` zsojka at seznam dot cz
2012-10-22 9:05 ` rguenth at gcc dot gnu.org
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From: zsojka at seznam dot cz @ 2012-10-21 16:15 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55005
--- Comment #3 from Zdenek Sojka <zsojka at seznam dot cz> 2012-10-21 16:14:53 UTC ---
(In reply to comment #2)
> Started with http://gcc.gnu.org/viewcvs?view=revision&revision=192538
Thanks for bisecting. The testcase from comment #1 was failing even before that
(though instead of segfaulting, the code ended in an endless loop), so it might
be a bit different problem.
^ permalink raw reply [flat|nested] 9+ messages in thread* [Bug tree-optimization/55005] [4.8 Regression] gcc.c-torture/execute/loop-3.c FAILs with -fPIC
2012-10-21 5:25 [Bug tree-optimization/55005] New: [4.8 Regression] gcc.c-torture/execute/loop-3.c FAILs with -fPIC zsojka at seznam dot cz
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2012-10-21 16:15 ` zsojka at seznam dot cz
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From: rguenth at gcc dot gnu.org @ 2012-10-22 9:05 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55005
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|--- |4.8.0
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2012-10-21 5:25 [Bug tree-optimization/55005] New: [4.8 Regression] gcc.c-torture/execute/loop-3.c FAILs with -fPIC zsojka at seznam dot cz
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2012-10-22 9:05 ` rguenth at gcc dot gnu.org
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From: mpolacek at gcc dot gnu.org @ 2012-10-22 12:54 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55005
--- Comment #4 from Marek Polacek <mpolacek at gcc dot gnu.org> 2012-10-22 12:53:47 UTC ---
$ gcc -O2 -funroll-loops -fPIC testcase.c && ./a.out
$ gcc -O2 -fpeel-loops -fPIC testcase.c && ./a.out
seem to be fine with current trunk. The others are failing though.
^ permalink raw reply [flat|nested] 9+ messages in thread* [Bug tree-optimization/55005] [4.8 Regression] gcc.c-torture/execute/loop-3.c FAILs with -fPIC
2012-10-21 5:25 [Bug tree-optimization/55005] New: [4.8 Regression] gcc.c-torture/execute/loop-3.c FAILs with -fPIC zsojka at seznam dot cz
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2012-10-22 12:54 ` mpolacek at gcc dot gnu.org
@ 2012-10-22 13:09 ` mpolacek at gcc dot gnu.org
2012-10-23 14:32 ` hubicka at gcc dot gnu.org
2012-10-23 15:06 ` jakub at gcc dot gnu.org
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From: mpolacek at gcc dot gnu.org @ 2012-10-22 13:09 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55005
--- Comment #5 from Marek Polacek <mpolacek at gcc dot gnu.org> 2012-10-22 13:08:40 UTC ---
In .jump there's
;; Function main (main, funcdef_no=2, decl_uid=1727, cgraph_uid=2) (executed
once)
Deleted 22 trivially dead insns
3 basic blocks, 1 edges.
(note 5 0 4 2 [bb 2] NOTE_INSN_BASIC_BLOCK)
(note 4 5 0 2 NOTE_INSN_FUNCTION_BEG)
Doesn't look right.
^ permalink raw reply [flat|nested] 9+ messages in thread* [Bug tree-optimization/55005] [4.8 Regression] gcc.c-torture/execute/loop-3.c FAILs with -fPIC
2012-10-21 5:25 [Bug tree-optimization/55005] New: [4.8 Regression] gcc.c-torture/execute/loop-3.c FAILs with -fPIC zsojka at seznam dot cz
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2012-10-22 13:09 ` mpolacek at gcc dot gnu.org
@ 2012-10-23 14:32 ` hubicka at gcc dot gnu.org
2012-10-23 15:06 ` jakub at gcc dot gnu.org
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From: hubicka at gcc dot gnu.org @ 2012-10-23 14:32 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55005
--- Comment #6 from Jan Hubicka <hubicka at gcc dot gnu.org> 2012-10-23 14:32:02 UTC ---
This is similar case as do-1.f90. We have:
Statement _6 = m_5 * 2147483647;
is executed at most 2 (bounded by 2) + 1 times in loop 1.
coming from:
while (i--)
{
g (i * 2147483647);
}
This overflows for i==4 and leads to undefined effect.
So I think the testcase is invalid.
Honza
^ permalink raw reply [flat|nested] 9+ messages in thread* [Bug tree-optimization/55005] [4.8 Regression] gcc.c-torture/execute/loop-3.c FAILs with -fPIC
2012-10-21 5:25 [Bug tree-optimization/55005] New: [4.8 Regression] gcc.c-torture/execute/loop-3.c FAILs with -fPIC zsojka at seznam dot cz
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2012-10-23 14:32 ` hubicka at gcc dot gnu.org
@ 2012-10-23 15:06 ` jakub at gcc dot gnu.org
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From: jakub at gcc dot gnu.org @ 2012-10-23 15:06 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55005
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
CC| |jakub at gcc dot gnu.org
Resolution| |INVALID
--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-10-23 15:05:46 UTC ---
Yeah, the undefined behavior is reached on the testcase unconditionally, so it
is definitely invalid.
^ permalink raw reply [flat|nested] 9+ messages in thread