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* [Bug rtl-optimization/17078] New: Jump into if(0)-substatement fails
@ 2004-08-18 11:05 paul dot woegerer at nsc dot com
2004-08-18 12:00 ` [Bug rtl-optimization/17078] " reichelt at gcc dot gnu dot org
` (7 more replies)
0 siblings, 8 replies; 9+ messages in thread
From: paul dot woegerer at nsc dot com @ 2004-08-18 11:05 UTC (permalink / raw)
To: gcc-bugs
On GCC 3.4.1 the following goto example generates wrong code.
On GCC 3.3.3 the return vale of this example is 1 as it should
be according to ANSI C "... If the first substatement is reached
via a label, the second substatment is not executed ..."
(see 6.6.4.1).
It looks to me that cfg_cleanup or some reachability test is not
taking into account that the if(0)-basic-block is entered via the
label and behaves too optimistic in elimiating it.
int main(int argc, char **argv)
{
int i = 0;
goto useless;
if(0)
{
useless:
i = 1;
}
else
{
i = 2;
}
return i;
}
--
Summary: Jump into if(0)-substatement fails
Product: gcc
Version: 3.4.1
Status: UNCONFIRMED
Severity: critical
Priority: P2
Component: rtl-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: paul dot woegerer at nsc dot com
CC: gcc-bugs at gcc dot gnu dot org,tal dot agmon at nsc dot
com
GCC build triplet: i686-pc-linux-gnu
GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17078
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug rtl-optimization/17078] Jump into if(0)-substatement fails
2004-08-18 11:05 [Bug rtl-optimization/17078] New: Jump into if(0)-substatement fails paul dot woegerer at nsc dot com
@ 2004-08-18 12:00 ` reichelt at gcc dot gnu dot org
2004-08-19 7:27 ` [Bug rtl-optimization/17078] [3.4 regression] " paul dot woegerer at nsc dot com
` (6 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: reichelt at gcc dot gnu dot org @ 2004-08-18 12:00 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From reichelt at gcc dot gnu dot org 2004-08-18 12:00 -------
Confirmed.
Remarks:
* This only happens with -O0.
* The return value is not even 0 or 2, but 16.
--
What |Removed |Added
----------------------------------------------------------------------------
CC| |reichelt at gcc dot gnu dot
| |org
Status|UNCONFIRMED |NEW
Ever Confirmed| |1
Keywords| |monitored, wrong-code
Known to fail| |3.4.0 3.4.1
Known to work| |3.3.4 3.5.0
Last reconfirmed|0000-00-00 00:00:00 |2004-08-18 12:00:29
date| |
Target Milestone|--- |3.4.2
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17078
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug rtl-optimization/17078] [3.4 regression] Jump into if(0)-substatement fails
2004-08-18 11:05 [Bug rtl-optimization/17078] New: Jump into if(0)-substatement fails paul dot woegerer at nsc dot com
2004-08-18 12:00 ` [Bug rtl-optimization/17078] " reichelt at gcc dot gnu dot org
@ 2004-08-19 7:27 ` paul dot woegerer at nsc dot com
2004-08-19 7:54 ` paul dot woegerer at nsc dot com
` (5 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: paul dot woegerer at nsc dot com @ 2004-08-19 7:27 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From paul dot woegerer at nsc dot com 2004-08-19 07:26 -------
(In reply to comment #1)
> Confirmed.
>
> Remarks:
> * This only happens with -O0.
> * The return value is not even 0 or 2, but 16.
>
With -O0 i also get return value 16. But with
-O2, -O3 and -Os i get 164 as return value.
I used GCC 3.4.1 in the following configuration:
Reading specs from /usr/local/gcc-3.4.1-native/lib/gcc/i686-pc-linux-gnu/3.4.1/specs
Configured with: ../gcc-3.4.1/configure --enable-languages=c,c++
--prefix=/usr/local/gcc-3.4.1-native
Thread model: posix
gcc version 3.4.1
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17078
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug rtl-optimization/17078] [3.4 regression] Jump into if(0)-substatement fails
2004-08-18 11:05 [Bug rtl-optimization/17078] New: Jump into if(0)-substatement fails paul dot woegerer at nsc dot com
2004-08-18 12:00 ` [Bug rtl-optimization/17078] " reichelt at gcc dot gnu dot org
2004-08-19 7:27 ` [Bug rtl-optimization/17078] [3.4 regression] " paul dot woegerer at nsc dot com
@ 2004-08-19 7:54 ` paul dot woegerer at nsc dot com
2004-08-19 10:21 ` reichelt at gcc dot gnu dot org
` (4 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: paul dot woegerer at nsc dot com @ 2004-08-19 7:54 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From paul dot woegerer at nsc dot com 2004-08-19 07:54 -------
Subject: Re: [3.4 regression] Jump into if(
0) -substatement fails
Morning Tal,
So i was wrong yesterday when i said something is wrong with the header
files.
Something is wrong with the compiler. Is this bug already reported to GNUs
bugzilla?
Paul
"paul dot woegerer at nsc dot com" <gcc-bugzilla@gcc.gnu.org>
08/19/2004 09:26 AM
Please respond to gcc-bugzilla
To: Paul.Woegerer@nsc.com
cc:
Subject: [Bug rtl-optimization/17078] [3.4 regression] Jump
into if(0) -substatement fails
------- Additional Comments From paul dot woegerer at nsc dot com
2004-08-19 07:26 -------
(In reply to comment #1)
> Confirmed.
>
> Remarks:
> * This only happens with -O0.
> * The return value is not even 0 or 2, but 16.
>
With -O0 i also get return value 16. But with
-O2, -O3 and -Os i get 164 as return value.
I used GCC 3.4.1 in the following configuration:
Reading specs from
/usr/local/gcc-3.4.1-native/lib/gcc/i686-pc-linux-gnu/3.4.1/specs
Configured with: ../gcc-3.4.1/configure --enable-languages=c,c++
--prefix=/usr/local/gcc-3.4.1-native
Thread model: posix
gcc version 3.4.1
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17078
------- You are receiving this mail because: -------
You reported the bug, or are watching the reporter.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17078
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug rtl-optimization/17078] [3.4 regression] Jump into if(0)-substatement fails
2004-08-18 11:05 [Bug rtl-optimization/17078] New: Jump into if(0)-substatement fails paul dot woegerer at nsc dot com
` (2 preceding siblings ...)
2004-08-19 7:54 ` paul dot woegerer at nsc dot com
@ 2004-08-19 10:21 ` reichelt at gcc dot gnu dot org
2004-08-22 23:50 ` mmitchel at gcc dot gnu dot org
` (3 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: reichelt at gcc dot gnu dot org @ 2004-08-19 10:21 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From reichelt at gcc dot gnu dot org 2004-08-19 10:21 -------
> With -O0 i also get return value 16. But with
> -O2, -O3 and -Os i get 164 as return value.
Hmm. With the C frontend I only get wrong numbers with -O0.
With the C++ frontend I get wrong numbers for all optimizations:
-O0 -O1 -O2 -O3 -Os. (I mostly get zeros, but that's not a
contradiction to the 164 mentioned above, since there's probably
some uninitialized memory involved).
Anyway, GCC is at fault here.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17078
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug rtl-optimization/17078] [3.4 regression] Jump into if(0)-substatement fails
2004-08-18 11:05 [Bug rtl-optimization/17078] New: Jump into if(0)-substatement fails paul dot woegerer at nsc dot com
` (3 preceding siblings ...)
2004-08-19 10:21 ` reichelt at gcc dot gnu dot org
@ 2004-08-22 23:50 ` mmitchel at gcc dot gnu dot org
2004-08-24 4:03 ` cvs-commit at gcc dot gnu dot org
` (2 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: mmitchel at gcc dot gnu dot org @ 2004-08-22 23:50 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From mmitchel at gcc dot gnu dot org 2004-08-22 23:50 -------
Roger, this looks to be a bug in expand_unreachable_stmt.
In particular, it looks like the return statement is never expanded because it
is considered unreachable due to the earlier goto. However, since the
then-clause of the if-statment falls off the bottom, the return-statement
becomes reachable again. Here, expand_unreachable_if_stmt should be returning
true, but instead returns false.
I've assigned this bug to you.
--
What |Removed |Added
----------------------------------------------------------------------------
CC| |roger at eyesopen dot com
AssignedTo|unassigned at gcc dot gnu |roger at eyesopen dot com
|dot org |
Status|NEW |ASSIGNED
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17078
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug rtl-optimization/17078] [3.4 regression] Jump into if(0)-substatement fails
2004-08-18 11:05 [Bug rtl-optimization/17078] New: Jump into if(0)-substatement fails paul dot woegerer at nsc dot com
` (4 preceding siblings ...)
2004-08-22 23:50 ` mmitchel at gcc dot gnu dot org
@ 2004-08-24 4:03 ` cvs-commit at gcc dot gnu dot org
2004-08-24 4:09 ` pinskia at gcc dot gnu dot org
2004-08-24 4:23 ` cvs-commit at gcc dot gnu dot org
7 siblings, 0 replies; 9+ messages in thread
From: cvs-commit at gcc dot gnu dot org @ 2004-08-24 4:03 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From cvs-commit at gcc dot gnu dot org 2004-08-24 04:02 -------
Subject: Bug 17078
CVSROOT: /cvs/gcc
Module name: gcc
Branch: gcc-3_4-branch
Changes by: sayle@gcc.gnu.org 2004-08-24 04:02:46
Modified files:
gcc : ChangeLog c-semantics.c
gcc/testsuite : ChangeLog
Added files:
gcc/testsuite/gcc.c-torture/execute: pr17078-1.c
Log message:
PR rtl-optimization/17078
* c-semantics.c (expand_unreachable_if_stmt): If the end of the
specified statement list is reachable, always return a non-NULL
pointer. If necessary, return error_mark_node.
* gcc.c-torture/execute/pr17078-1.c: New test case.
Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=2.2326.2.589&r2=2.2326.2.590
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/c-semantics.c.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=1.74.4.2&r2=1.74.4.3
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=1.3389.2.256&r2=1.3389.2.257
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.c-torture/execute/pr17078-1.c.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=NONE&r2=1.1.2.1
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17078
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug rtl-optimization/17078] [3.4 regression] Jump into if(0)-substatement fails
2004-08-18 11:05 [Bug rtl-optimization/17078] New: Jump into if(0)-substatement fails paul dot woegerer at nsc dot com
` (5 preceding siblings ...)
2004-08-24 4:03 ` cvs-commit at gcc dot gnu dot org
@ 2004-08-24 4:09 ` pinskia at gcc dot gnu dot org
2004-08-24 4:23 ` cvs-commit at gcc dot gnu dot org
7 siblings, 0 replies; 9+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-08-24 4:09 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From pinskia at gcc dot gnu dot org 2004-08-24 04:09 -------
Fixed.
--
What |Removed |Added
----------------------------------------------------------------------------
Status|ASSIGNED |RESOLVED
Resolution| |FIXED
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17078
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug rtl-optimization/17078] [3.4 regression] Jump into if(0)-substatement fails
2004-08-18 11:05 [Bug rtl-optimization/17078] New: Jump into if(0)-substatement fails paul dot woegerer at nsc dot com
` (6 preceding siblings ...)
2004-08-24 4:09 ` pinskia at gcc dot gnu dot org
@ 2004-08-24 4:23 ` cvs-commit at gcc dot gnu dot org
7 siblings, 0 replies; 9+ messages in thread
From: cvs-commit at gcc dot gnu dot org @ 2004-08-24 4:23 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From cvs-commit at gcc dot gnu dot org 2004-08-24 04:23 -------
Subject: Bug 17078
CVSROOT: /cvs/gcc
Module name: gcc
Changes by: sayle@gcc.gnu.org 2004-08-24 04:23:31
Modified files:
gcc/testsuite : ChangeLog
Added files:
gcc/testsuite/gcc.c-torture/execute: pr17078-1.c
Log message:
PR rtl-optimization/17078
* gcc.c-torture/execute/pr17078-1.c: New test case.
Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&r1=1.4177&r2=1.4178
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.c-torture/execute/pr17078-1.c.diff?cvsroot=gcc&r1=1.1&r2=1.2
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17078
^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2004-08-24 4:23 UTC | newest]
Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
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2004-08-18 11:05 [Bug rtl-optimization/17078] New: Jump into if(0)-substatement fails paul dot woegerer at nsc dot com
2004-08-18 12:00 ` [Bug rtl-optimization/17078] " reichelt at gcc dot gnu dot org
2004-08-19 7:27 ` [Bug rtl-optimization/17078] [3.4 regression] " paul dot woegerer at nsc dot com
2004-08-19 7:54 ` paul dot woegerer at nsc dot com
2004-08-19 10:21 ` reichelt at gcc dot gnu dot org
2004-08-22 23:50 ` mmitchel at gcc dot gnu dot org
2004-08-24 4:03 ` cvs-commit at gcc dot gnu dot org
2004-08-24 4:09 ` pinskia at gcc dot gnu dot org
2004-08-24 4:23 ` cvs-commit at gcc dot gnu dot org
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