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* [Bug rtl-optimization/64041] New: wrong code at -O2 and -O3 on x86_64-linux-gnu
@ 2014-11-24 7:15 su at cs dot ucdavis.edu
2014-11-24 8:17 ` [Bug rtl-optimization/64041] [4.9/5 Regression] " jakub at gcc dot gnu.org
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: su at cs dot ucdavis.edu @ 2014-11-24 7:15 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64041
Bug ID: 64041
Summary: wrong code at -O2 and -O3 on x86_64-linux-gnu
Product: gcc
Version: 5.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: rtl-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: su at cs dot ucdavis.edu
The current gcc trunk and 4.9.x miscompile the following code on x86_64-linux
at -O2 and -O3 in both 32-bit and 64-bit modes.
This is a regression from 4.8.x.
$ gcc-trunk -v
Using built-in specs.
COLLECT_GCC=gcc-trunk
COLLECT_LTO_WRAPPER=/usr/local/gcc-trunk/libexec/gcc/x86_64-unknown-linux-gnu/5.0.0/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: ../gcc-trunk/configure --prefix=/usr/local/gcc-trunk
--enable-languages=c,c++ --disable-werror --enable-multilib
Thread model: posix
gcc version 5.0.0 20141122 (experimental) [trunk revision 217971] (GCC)
$ gcc-trunk -Os small.c; a.out
0
$ gcc-4.8 -O2 small.c; a.out
0
$
$ gcc-trunk -O2 small.c; a.out
$ gcc-4.9 -O2 small.c; a.out
$
----------------------------------
int printf (const char *, ...);
int a, b = 1, d;
union U1
{
unsigned int f0;
int f1;
};
union U2
{
int f2;
int f3;
} c;
int
fn1 (int p)
{
int t = p && a || p && a && p;
return t ? t : a;
}
unsigned
fn2 (union U1 p1, union U2 p2)
{
if (p1.f1 <= 0)
{
for (; p2.f2;)
c.f2 = 0;
p2.f2 = fn1 (d);
}
return p2.f3;
}
int
main ()
{
if (b)
{
union U1 f = { 0xFFFFFFFFU };
fn2 (f, c);
}
printf ("%d\n", 0);
return 0;
}
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug rtl-optimization/64041] [4.9/5 Regression] wrong code at -O2 and -O3 on x86_64-linux-gnu
2014-11-24 7:15 [Bug rtl-optimization/64041] New: wrong code at -O2 and -O3 on x86_64-linux-gnu su at cs dot ucdavis.edu
@ 2014-11-24 8:17 ` jakub at gcc dot gnu.org
2014-11-24 10:59 ` rguenth at gcc dot gnu.org
2014-11-25 17:37 ` jamborm at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: jakub at gcc dot gnu.org @ 2014-11-24 8:17 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64041
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2014-11-24
CC| |hubicka at gcc dot gnu.org,
| |jakub at gcc dot gnu.org
Target Milestone|--- |4.9.3
Summary|wrong code at -O2 and -O3 |[4.9/5 Regression] wrong
|on x86_64-linux-gnu |code at -O2 and -O3 on
| |x86_64-linux-gnu
Ever confirmed|0 |1
--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Started with r208831.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug rtl-optimization/64041] [4.9/5 Regression] wrong code at -O2 and -O3 on x86_64-linux-gnu
2014-11-24 7:15 [Bug rtl-optimization/64041] New: wrong code at -O2 and -O3 on x86_64-linux-gnu su at cs dot ucdavis.edu
2014-11-24 8:17 ` [Bug rtl-optimization/64041] [4.9/5 Regression] " jakub at gcc dot gnu.org
@ 2014-11-24 10:59 ` rguenth at gcc dot gnu.org
2014-11-25 17:37 ` jamborm at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: rguenth at gcc dot gnu.org @ 2014-11-24 10:59 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64041
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |wrong-code
Priority|P3 |P1
CC| |jamborm at gcc dot gnu.org
--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
It looks similar to the signed/unsigned IPA CP issue.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug rtl-optimization/64041] [4.9/5 Regression] wrong code at -O2 and -O3 on x86_64-linux-gnu
2014-11-24 7:15 [Bug rtl-optimization/64041] New: wrong code at -O2 and -O3 on x86_64-linux-gnu su at cs dot ucdavis.edu
2014-11-24 8:17 ` [Bug rtl-optimization/64041] [4.9/5 Regression] " jakub at gcc dot gnu.org
2014-11-24 10:59 ` rguenth at gcc dot gnu.org
@ 2014-11-25 17:37 ` jamborm at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: jamborm at gcc dot gnu.org @ 2014-11-25 17:37 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64041
Martin Jambor <jamborm at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
Resolution|--- |DUPLICATE
--- Comment #3 from Martin Jambor <jamborm at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #2)
> It looks similar to the signed/unsigned IPA CP issue.
Indeed, I have added this testcase to the patch.
*** This bug has been marked as a duplicate of bug 63551 ***
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2014-11-25 17:37 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2014-11-24 7:15 [Bug rtl-optimization/64041] New: wrong code at -O2 and -O3 on x86_64-linux-gnu su at cs dot ucdavis.edu
2014-11-24 8:17 ` [Bug rtl-optimization/64041] [4.9/5 Regression] " jakub at gcc dot gnu.org
2014-11-24 10:59 ` rguenth at gcc dot gnu.org
2014-11-25 17:37 ` jamborm at gcc dot gnu.org
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