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* [Bug middle-end/45017] New: miscompile with bitfield and optimization
@ 2010-07-21 11:23 borntraeger at de dot ibm dot com
2010-07-21 16:21 ` [Bug middle-end/45017] " rguenth at gcc dot gnu dot org
` (13 more replies)
0 siblings, 14 replies; 15+ messages in thread
From: borntraeger at de dot ibm dot com @ 2010-07-21 11:23 UTC (permalink / raw)
To: gcc-bugs
The following testcase has a different result with 4.6 and -O1/2/3
gcc4.5: all optimizations:
r1: 15 r2: 2
gcc4.6: -O0
r1: 15 r2: 2
gcc4.6: -O1,-O2..
r1: 47 r2: 2
#include <stdio.h>
int tester(char *bytes)
{
union {
struct {
unsigned int r1:4;
unsigned int r2:4;
} fmt;
char value[1];
} ovl;
ovl.value[0] = bytes[0];
printf("r1: %d r2: %d\n", ovl.fmt.r1, ovl.fmt.r2);
return 0;
}
int main()
{
char buff = 0x2f;
return tester(&buff);
}
--
Summary: miscompile with bitfield and optimization
Product: gcc
Version: 4.6.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: borntraeger at de dot ibm dot com
GCC build triplet: i686-pc-linux-gnu and s390x-ibm-linux-gnu
GCC host triplet: i686-pc-linux-gnu and s390x-ibm-linux-gnu
GCC target triplet: i686-pc-linux-gnu and s390x-ibm-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45017
^ permalink raw reply [flat|nested] 15+ messages in thread
* [Bug middle-end/45017] miscompile with bitfield and optimization
2010-07-21 11:23 [Bug middle-end/45017] New: miscompile with bitfield and optimization borntraeger at de dot ibm dot com
@ 2010-07-21 16:21 ` rguenth at gcc dot gnu dot org
2010-07-22 12:15 ` rguenth at gcc dot gnu dot org
` (12 subsequent siblings)
13 siblings, 0 replies; 15+ messages in thread
From: rguenth at gcc dot gnu dot org @ 2010-07-21 16:21 UTC (permalink / raw)
To: gcc-bugs
------- Comment #1 from rguenth at gcc dot gnu dot org 2010-07-21 16:20 -------
Confirmed. This is caused by mem-ref & VN. Thus, mine.
--
rguenth at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
AssignedTo|unassigned at gcc dot gnu |rguenth at gcc dot gnu dot
|dot org |org
Status|UNCONFIRMED |ASSIGNED
Ever Confirmed|0 |1
Last reconfirmed|0000-00-00 00:00:00 |2010-07-21 16:20:44
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45017
^ permalink raw reply [flat|nested] 15+ messages in thread
* [Bug middle-end/45017] miscompile with bitfield and optimization
2010-07-21 11:23 [Bug middle-end/45017] New: miscompile with bitfield and optimization borntraeger at de dot ibm dot com
2010-07-21 16:21 ` [Bug middle-end/45017] " rguenth at gcc dot gnu dot org
2010-07-22 12:15 ` rguenth at gcc dot gnu dot org
@ 2010-07-22 12:15 ` rguenth at gcc dot gnu dot org
2010-07-22 12:41 ` borntraeger at de dot ibm dot com
` (10 subsequent siblings)
13 siblings, 0 replies; 15+ messages in thread
From: rguenth at gcc dot gnu dot org @ 2010-07-22 12:15 UTC (permalink / raw)
To: gcc-bugs
------- Comment #2 from rguenth at gcc dot gnu dot org 2010-07-22 12:14 -------
Subject: Bug 45017
Author: rguenth
Date: Thu Jul 22 12:14:27 2010
New Revision: 162411
URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=162411
Log:
2010-07-22 Richard Guenther <rguenther@suse.de>
PR tree-optimization/45017
* tree-ssa-sccvn.c (vn_reference_eq): Make sure we honor
TYPE_PRECISION of integral types in addition to size.
* gcc.c-torture/execute/pr45017.c: New testcase.
Added:
trunk/gcc/testsuite/gcc.c-torture/execute/pr45017.c
Modified:
trunk/gcc/ChangeLog
trunk/gcc/testsuite/ChangeLog
trunk/gcc/tree-ssa-sccvn.c
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45017
^ permalink raw reply [flat|nested] 15+ messages in thread
* [Bug middle-end/45017] miscompile with bitfield and optimization
2010-07-21 11:23 [Bug middle-end/45017] New: miscompile with bitfield and optimization borntraeger at de dot ibm dot com
2010-07-21 16:21 ` [Bug middle-end/45017] " rguenth at gcc dot gnu dot org
@ 2010-07-22 12:15 ` rguenth at gcc dot gnu dot org
2010-07-22 12:15 ` rguenth at gcc dot gnu dot org
` (11 subsequent siblings)
13 siblings, 0 replies; 15+ messages in thread
From: rguenth at gcc dot gnu dot org @ 2010-07-22 12:15 UTC (permalink / raw)
To: gcc-bugs
------- Comment #3 from rguenth at gcc dot gnu dot org 2010-07-22 12:15 -------
Fixed.
--
rguenth at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|ASSIGNED |RESOLVED
Resolution| |FIXED
Target Milestone|--- |4.6.0
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45017
^ permalink raw reply [flat|nested] 15+ messages in thread
* [Bug middle-end/45017] miscompile with bitfield and optimization
2010-07-21 11:23 [Bug middle-end/45017] New: miscompile with bitfield and optimization borntraeger at de dot ibm dot com
` (2 preceding siblings ...)
2010-07-22 12:15 ` rguenth at gcc dot gnu dot org
@ 2010-07-22 12:41 ` borntraeger at de dot ibm dot com
2010-07-22 12:42 ` rguenther at suse dot de
` (9 subsequent siblings)
13 siblings, 0 replies; 15+ messages in thread
From: borntraeger at de dot ibm dot com @ 2010-07-22 12:41 UTC (permalink / raw)
To: gcc-bugs
------- Comment #4 from borntraeger at de dot ibm dot com 2010-07-22 12:41 -------
the testcase will fail on big endian machines.
since r2=f and r1=2 instead of r2=2 and r1=f.
Can you adopt the testcase to check the endianess?
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45017
^ permalink raw reply [flat|nested] 15+ messages in thread
* [Bug middle-end/45017] miscompile with bitfield and optimization
2010-07-21 11:23 [Bug middle-end/45017] New: miscompile with bitfield and optimization borntraeger at de dot ibm dot com
` (3 preceding siblings ...)
2010-07-22 12:41 ` borntraeger at de dot ibm dot com
@ 2010-07-22 12:42 ` rguenther at suse dot de
2010-07-22 12:59 ` schwab at linux-m68k dot org
` (8 subsequent siblings)
13 siblings, 0 replies; 15+ messages in thread
From: rguenther at suse dot de @ 2010-07-22 12:42 UTC (permalink / raw)
To: gcc-bugs
------- Comment #5 from rguenther at suse dot de 2010-07-22 12:42 -------
Subject: Re: miscompile with bitfield and
optimization
On Thu, 22 Jul 2010, borntraeger at de dot ibm dot com wrote:
> ------- Comment #4 from borntraeger at de dot ibm dot com 2010-07-22 12:41 -------
> the testcase will fail on big endian machines.
> since r2=f and r1=2 instead of r2=2 and r1=f.
> Can you adopt the testcase to check the endianess?
Huh? This is one byte, how does endianess come into play?
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45017
^ permalink raw reply [flat|nested] 15+ messages in thread
* [Bug middle-end/45017] miscompile with bitfield and optimization
2010-07-21 11:23 [Bug middle-end/45017] New: miscompile with bitfield and optimization borntraeger at de dot ibm dot com
` (4 preceding siblings ...)
2010-07-22 12:42 ` rguenther at suse dot de
@ 2010-07-22 12:59 ` schwab at linux-m68k dot org
2010-07-23 2:49 ` drow at gcc dot gnu dot org
` (7 subsequent siblings)
13 siblings, 0 replies; 15+ messages in thread
From: schwab at linux-m68k dot org @ 2010-07-22 12:59 UTC (permalink / raw)
To: gcc-bugs
------- Comment #6 from schwab at linux-m68k dot org 2010-07-22 12:59 -------
> Huh? This is one byte, how does endianess come into play?
By the use of bitfields.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45017
^ permalink raw reply [flat|nested] 15+ messages in thread
* [Bug middle-end/45017] miscompile with bitfield and optimization
2010-07-21 11:23 [Bug middle-end/45017] New: miscompile with bitfield and optimization borntraeger at de dot ibm dot com
` (5 preceding siblings ...)
2010-07-22 12:59 ` schwab at linux-m68k dot org
@ 2010-07-23 2:49 ` drow at gcc dot gnu dot org
2010-07-23 13:17 ` danglin at gcc dot gnu dot org
` (6 subsequent siblings)
13 siblings, 0 replies; 15+ messages in thread
From: drow at gcc dot gnu dot org @ 2010-07-23 2:49 UTC (permalink / raw)
To: gcc-bugs
------- Comment #7 from drow at gcc dot gnu dot org 2010-07-23 02:49 -------
FYI, confirmed to fail for ColdFire.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45017
^ permalink raw reply [flat|nested] 15+ messages in thread
* [Bug middle-end/45017] miscompile with bitfield and optimization
2010-07-21 11:23 [Bug middle-end/45017] New: miscompile with bitfield and optimization borntraeger at de dot ibm dot com
` (6 preceding siblings ...)
2010-07-23 2:49 ` drow at gcc dot gnu dot org
@ 2010-07-23 13:17 ` danglin at gcc dot gnu dot org
2010-07-25 15:44 ` ebotcazou at gcc dot gnu dot org
` (5 subsequent siblings)
13 siblings, 0 replies; 15+ messages in thread
From: danglin at gcc dot gnu dot org @ 2010-07-23 13:17 UTC (permalink / raw)
To: gcc-bugs
------- Comment #8 from danglin at gcc dot gnu dot org 2010-07-23 13:17 -------
Test fails on hppa64-hp-hpux11.11.
--
danglin at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |danglin at gcc dot gnu dot
| |org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45017
^ permalink raw reply [flat|nested] 15+ messages in thread
* [Bug middle-end/45017] miscompile with bitfield and optimization
2010-07-21 11:23 [Bug middle-end/45017] New: miscompile with bitfield and optimization borntraeger at de dot ibm dot com
` (7 preceding siblings ...)
2010-07-23 13:17 ` danglin at gcc dot gnu dot org
@ 2010-07-25 15:44 ` ebotcazou at gcc dot gnu dot org
2010-07-25 16:46 ` mikpe at it dot uu dot se
` (4 subsequent siblings)
13 siblings, 0 replies; 15+ messages in thread
From: ebotcazou at gcc dot gnu dot org @ 2010-07-25 15:44 UTC (permalink / raw)
To: gcc-bugs
------- Comment #9 from ebotcazou at gcc dot gnu dot org 2010-07-25 15:44 -------
On the SPARC as well.
--
ebotcazou at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |ebotcazou at gcc dot gnu dot
| |org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45017
^ permalink raw reply [flat|nested] 15+ messages in thread
* [Bug middle-end/45017] miscompile with bitfield and optimization
2010-07-21 11:23 [Bug middle-end/45017] New: miscompile with bitfield and optimization borntraeger at de dot ibm dot com
` (8 preceding siblings ...)
2010-07-25 15:44 ` ebotcazou at gcc dot gnu dot org
@ 2010-07-25 16:46 ` mikpe at it dot uu dot se
2010-07-25 16:54 ` borntraeger at de dot ibm dot com
` (3 subsequent siblings)
13 siblings, 0 replies; 15+ messages in thread
From: mikpe at it dot uu dot se @ 2010-07-25 16:46 UTC (permalink / raw)
To: gcc-bugs
------- Comment #10 from mikpe at it dot uu dot se 2010-07-25 16:45 -------
This test fails on powerpc64-linux and sparc64-linux.
--
mikpe at it dot uu dot se changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |mikpe at it dot uu dot se
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45017
^ permalink raw reply [flat|nested] 15+ messages in thread
* [Bug middle-end/45017] miscompile with bitfield and optimization
2010-07-21 11:23 [Bug middle-end/45017] New: miscompile with bitfield and optimization borntraeger at de dot ibm dot com
` (9 preceding siblings ...)
2010-07-25 16:46 ` mikpe at it dot uu dot se
@ 2010-07-25 16:54 ` borntraeger at de dot ibm dot com
2010-07-25 17:13 ` dave at hiauly1 dot hia dot nrc dot ca
` (2 subsequent siblings)
13 siblings, 0 replies; 15+ messages in thread
From: borntraeger at de dot ibm dot com @ 2010-07-25 16:54 UTC (permalink / raw)
To: gcc-bugs
------- Comment #11 from borntraeger at de dot ibm dot com 2010-07-25 16:54 -------
Something like the following should do the trick.
Is endian.h available on all supported platforms?
*** gcc.c-torture/execute/pr45017.c.orig
--- gcc.c-torture/execute/pr45017.c
***************
*** 1,9 ****
--- 1,17 ----
+ #include <endian.h>
+
int tester(char *bytes)
{
union {
struct {
+ # if __BYTE_ORDER == __BIG_ENDIAN
+ unsigned int r2:4;
+ unsigned int r1:4;
+ # endif
+ # if __BYTE_ORDER == __LITTLE_ENDIAN
unsigned int r1:4;
unsigned int r2:4;
+ # endif
} fmt;
char value[1];
} ovl;
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45017
^ permalink raw reply [flat|nested] 15+ messages in thread
* [Bug middle-end/45017] miscompile with bitfield and optimization
2010-07-21 11:23 [Bug middle-end/45017] New: miscompile with bitfield and optimization borntraeger at de dot ibm dot com
` (10 preceding siblings ...)
2010-07-25 16:54 ` borntraeger at de dot ibm dot com
@ 2010-07-25 17:13 ` dave at hiauly1 dot hia dot nrc dot ca
2010-07-25 17:15 ` mikpe at it dot uu dot se
2010-07-26 10:13 ` borntraeger at de dot ibm dot com
13 siblings, 0 replies; 15+ messages in thread
From: dave at hiauly1 dot hia dot nrc dot ca @ 2010-07-25 17:13 UTC (permalink / raw)
To: gcc-bugs
------- Comment #12 from dave at hiauly1 dot hia dot nrc dot ca 2010-07-25 17:13 -------
Subject: Re: miscompile with bitfield and optimization
> Is endian.h available on all supported platforms?
It is not available on HP-UX.
Dave
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45017
^ permalink raw reply [flat|nested] 15+ messages in thread
* [Bug middle-end/45017] miscompile with bitfield and optimization
2010-07-21 11:23 [Bug middle-end/45017] New: miscompile with bitfield and optimization borntraeger at de dot ibm dot com
` (11 preceding siblings ...)
2010-07-25 17:13 ` dave at hiauly1 dot hia dot nrc dot ca
@ 2010-07-25 17:15 ` mikpe at it dot uu dot se
2010-07-26 10:13 ` borntraeger at de dot ibm dot com
13 siblings, 0 replies; 15+ messages in thread
From: mikpe at it dot uu dot se @ 2010-07-25 17:15 UTC (permalink / raw)
To: gcc-bugs
------- Comment #13 from mikpe at it dot uu dot se 2010-07-25 17:15 -------
<endian.h> is non-standard. For instance, Solaris 10 doesn't have it.
Does the test case really require explicit bit fields? Does it work (as in show
the miscompile before the fix) with shift & mask operations instead?
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45017
^ permalink raw reply [flat|nested] 15+ messages in thread
* [Bug middle-end/45017] miscompile with bitfield and optimization
2010-07-21 11:23 [Bug middle-end/45017] New: miscompile with bitfield and optimization borntraeger at de dot ibm dot com
` (12 preceding siblings ...)
2010-07-25 17:15 ` mikpe at it dot uu dot se
@ 2010-07-26 10:13 ` borntraeger at de dot ibm dot com
13 siblings, 0 replies; 15+ messages in thread
From: borntraeger at de dot ibm dot com @ 2010-07-26 10:13 UTC (permalink / raw)
To: gcc-bugs
------- Comment #14 from borntraeger at de dot ibm dot com 2010-07-26 10:13 -------
I have seen the original problem only with bitfields.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45017
^ permalink raw reply [flat|nested] 15+ messages in thread
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2010-07-21 11:23 [Bug middle-end/45017] New: miscompile with bitfield and optimization borntraeger at de dot ibm dot com
2010-07-21 16:21 ` [Bug middle-end/45017] " rguenth at gcc dot gnu dot org
2010-07-22 12:15 ` rguenth at gcc dot gnu dot org
2010-07-22 12:15 ` rguenth at gcc dot gnu dot org
2010-07-22 12:41 ` borntraeger at de dot ibm dot com
2010-07-22 12:42 ` rguenther at suse dot de
2010-07-22 12:59 ` schwab at linux-m68k dot org
2010-07-23 2:49 ` drow at gcc dot gnu dot org
2010-07-23 13:17 ` danglin at gcc dot gnu dot org
2010-07-25 15:44 ` ebotcazou at gcc dot gnu dot org
2010-07-25 16:46 ` mikpe at it dot uu dot se
2010-07-25 16:54 ` borntraeger at de dot ibm dot com
2010-07-25 17:13 ` dave at hiauly1 dot hia dot nrc dot ca
2010-07-25 17:15 ` mikpe at it dot uu dot se
2010-07-26 10:13 ` borntraeger at de dot ibm dot com
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