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* [Bug rtl-optimization/40906] New: Wrong code generated for push of long double
@ 2009-07-29 17:04 mikulas at artax dot karlin dot mff dot cuni dot cz
2009-07-29 17:07 ` [Bug rtl-optimization/40906] " mikulas at artax dot karlin dot mff dot cuni dot cz
` (5 more replies)
0 siblings, 6 replies; 7+ messages in thread
From: mikulas at artax dot karlin dot mff dot cuni dot cz @ 2009-07-29 17:04 UTC (permalink / raw)
To: gcc-bugs
Hi. Try this program:
#include <stdlib.h>
void f(long double a)
{
if (a != 1.0) abort();
}
int g(long double b)
{
f(b);
return 0;
}
int main(void)
{
g(1.0);
return 0;
}
Compile it with "-O2 -mpush-args -mno-accumulate-outgoing-args
-fomit-frame-pointer -fno-inline"
In gcc 4.3.2 it works, in gcc-4.4.1 it aborts. If you add -m128bit-long-double,
both gcc 4.3 and 4.4 fail. The reason is that push of long double in the
function "g" is badly generated --- it is pushing value that is already on the
stack and while it is pushing it, the stack pointer changes. Gcc tries to
compensate for it, but the code is buggy and it ends up pushing wrong words.
--
Summary: Wrong code generated for push of long double
Product: gcc
Version: 4.4.1
Status: UNCONFIRMED
Severity: major
Priority: P3
Component: rtl-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: mikulas at artax dot karlin dot mff dot cuni dot cz
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=40906
^ permalink raw reply [flat|nested] 7+ messages in thread* [Bug rtl-optimization/40906] Wrong code generated for push of long double 2009-07-29 17:04 [Bug rtl-optimization/40906] New: Wrong code generated for push of long double mikulas at artax dot karlin dot mff dot cuni dot cz @ 2009-07-29 17:07 ` mikulas at artax dot karlin dot mff dot cuni dot cz 2009-07-29 18:15 ` [Bug target/40906] " rguenth at gcc dot gnu dot org ` (4 subsequent siblings) 5 siblings, 0 replies; 7+ messages in thread From: mikulas at artax dot karlin dot mff dot cuni dot cz @ 2009-07-29 17:07 UTC (permalink / raw) To: gcc-bugs ------- Comment #1 from mikulas at artax dot karlin dot mff dot cuni dot cz 2009-07-29 17:07 ------- Created an attachment (id=18270) --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=18270&action=view) A patch for the bug A patch for the problem. 1. reverse the direction of "change_address" loop. That fixes 4.3->4.4 regression for 96-bit long double. 2. in case of 128-bit long double, the value "4" is subtracted from the stack pointer before the copying starts. We need to compensate for it by adding "4" to the source address if the source address in on the stack. Problem "2" should be backported to gcc-4.3 and earlier versions. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40906 ^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug target/40906] Wrong code generated for push of long double 2009-07-29 17:04 [Bug rtl-optimization/40906] New: Wrong code generated for push of long double mikulas at artax dot karlin dot mff dot cuni dot cz 2009-07-29 17:07 ` [Bug rtl-optimization/40906] " mikulas at artax dot karlin dot mff dot cuni dot cz @ 2009-07-29 18:15 ` rguenth at gcc dot gnu dot org 2009-08-05 14:42 ` uros at gcc dot gnu dot org ` (3 subsequent siblings) 5 siblings, 0 replies; 7+ messages in thread From: rguenth at gcc dot gnu dot org @ 2009-07-29 18:15 UTC (permalink / raw) To: gcc-bugs ------- Comment #2 from rguenth at gcc dot gnu dot org 2009-07-29 18:15 ------- patches should be sent to gcc-patches with a proper changelog entry and a note on how you tested the patch. -- rguenth at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- Keywords| |ABI, wrong-code http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40906 ^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug target/40906] Wrong code generated for push of long double 2009-07-29 17:04 [Bug rtl-optimization/40906] New: Wrong code generated for push of long double mikulas at artax dot karlin dot mff dot cuni dot cz 2009-07-29 17:07 ` [Bug rtl-optimization/40906] " mikulas at artax dot karlin dot mff dot cuni dot cz 2009-07-29 18:15 ` [Bug target/40906] " rguenth at gcc dot gnu dot org @ 2009-08-05 14:42 ` uros at gcc dot gnu dot org 2009-08-05 18:05 ` uros at gcc dot gnu dot org ` (2 subsequent siblings) 5 siblings, 0 replies; 7+ messages in thread From: uros at gcc dot gnu dot org @ 2009-08-05 14:42 UTC (permalink / raw) To: gcc-bugs ------- Comment #3 from uros at gcc dot gnu dot org 2009-08-05 14:42 ------- Subject: Bug 40906 Author: uros Date: Wed Aug 5 14:41:54 2009 New Revision: 150486 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=150486 Log: PR target/40906 * config/i386/i386.c (ix86_split_long_move): Fix push of multi-part source operand. testsuite/ChangeLog: PR target/40906 * gcc.target/i386/pr40906-1.c: New test. * gcc.target/i386/pr40906-2.c: Ditto. * gcc.target/i386/pr40906-3.c: Ditto. Added: trunk/gcc/testsuite/gcc.target/i386/pr40906-1.c trunk/gcc/testsuite/gcc.target/i386/pr40906-2.c trunk/gcc/testsuite/gcc.target/i386/pr40906-3.c Modified: trunk/gcc/ChangeLog trunk/gcc/config/i386/i386.c trunk/gcc/testsuite/ChangeLog -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40906 ^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug target/40906] Wrong code generated for push of long double 2009-07-29 17:04 [Bug rtl-optimization/40906] New: Wrong code generated for push of long double mikulas at artax dot karlin dot mff dot cuni dot cz ` (2 preceding siblings ...) 2009-08-05 14:42 ` uros at gcc dot gnu dot org @ 2009-08-05 18:05 ` uros at gcc dot gnu dot org 2009-08-05 21:17 ` uros at gcc dot gnu dot org 2009-08-05 21:19 ` ubizjak at gmail dot com 5 siblings, 0 replies; 7+ messages in thread From: uros at gcc dot gnu dot org @ 2009-08-05 18:05 UTC (permalink / raw) To: gcc-bugs ------- Comment #4 from uros at gcc dot gnu dot org 2009-08-05 18:05 ------- Subject: Bug 40906 Author: uros Date: Wed Aug 5 18:04:42 2009 New Revision: 150497 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=150497 Log: PR target/40906 * config/i386/i386.c (ix86_split_long_move): Fix push of multi-part source operand. testsuite/ChangeLog: PR target/40906 * gcc.target/i386/pr40906-1.c: New test. * gcc.target/i386/pr40906-2.c: Ditto. * gcc.target/i386/pr40906-3.c: Ditto. Added: branches/gcc-4_4-branch/gcc/testsuite/gcc.target/i386/pr40906-1.c branches/gcc-4_4-branch/gcc/testsuite/gcc.target/i386/pr40906-2.c branches/gcc-4_4-branch/gcc/testsuite/gcc.target/i386/pr40906-3.c Modified: branches/gcc-4_4-branch/gcc/ChangeLog branches/gcc-4_4-branch/gcc/config/i386/i386.c branches/gcc-4_4-branch/gcc/testsuite/ChangeLog -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40906 ^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug target/40906] Wrong code generated for push of long double 2009-07-29 17:04 [Bug rtl-optimization/40906] New: Wrong code generated for push of long double mikulas at artax dot karlin dot mff dot cuni dot cz ` (3 preceding siblings ...) 2009-08-05 18:05 ` uros at gcc dot gnu dot org @ 2009-08-05 21:17 ` uros at gcc dot gnu dot org 2009-08-05 21:19 ` ubizjak at gmail dot com 5 siblings, 0 replies; 7+ messages in thread From: uros at gcc dot gnu dot org @ 2009-08-05 21:17 UTC (permalink / raw) To: gcc-bugs ------- Comment #5 from uros at gcc dot gnu dot org 2009-08-05 21:17 ------- Subject: Bug 40906 Author: uros Date: Wed Aug 5 21:16:52 2009 New Revision: 150501 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=150501 Log: PR target/40906 * config/i386/i386.c (ix86_split_long_move): Fix push of multi-part source operand. testsuite/ChangeLog: PR target/40906 * gcc.target/i386/pr40906-1.c: New test. * gcc.target/i386/pr40906-2.c: Ditto. * gcc.target/i386/pr40906-3.c: Ditto. Added: branches/gcc-4_3-branch/gcc/testsuite/gcc.target/i386/pr40906-1.c branches/gcc-4_3-branch/gcc/testsuite/gcc.target/i386/pr40906-2.c branches/gcc-4_3-branch/gcc/testsuite/gcc.target/i386/pr40906-3.c Modified: branches/gcc-4_3-branch/gcc/ChangeLog branches/gcc-4_3-branch/gcc/config/i386/i386.c branches/gcc-4_3-branch/gcc/testsuite/ChangeLog -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40906 ^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug target/40906] Wrong code generated for push of long double 2009-07-29 17:04 [Bug rtl-optimization/40906] New: Wrong code generated for push of long double mikulas at artax dot karlin dot mff dot cuni dot cz ` (4 preceding siblings ...) 2009-08-05 21:17 ` uros at gcc dot gnu dot org @ 2009-08-05 21:19 ` ubizjak at gmail dot com 5 siblings, 0 replies; 7+ messages in thread From: ubizjak at gmail dot com @ 2009-08-05 21:19 UTC (permalink / raw) To: gcc-bugs ------- Comment #6 from ubizjak at gmail dot com 2009-08-05 21:19 ------- Fixed. -- ubizjak at gmail dot com changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Known to fail| |4.4.1 4.3.4 Resolution| |FIXED Target Milestone|--- |4.3.5 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40906 ^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2009-08-05 21:19 UTC | newest] Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2009-07-29 17:04 [Bug rtl-optimization/40906] New: Wrong code generated for push of long double mikulas at artax dot karlin dot mff dot cuni dot cz 2009-07-29 17:07 ` [Bug rtl-optimization/40906] " mikulas at artax dot karlin dot mff dot cuni dot cz 2009-07-29 18:15 ` [Bug target/40906] " rguenth at gcc dot gnu dot org 2009-08-05 14:42 ` uros at gcc dot gnu dot org 2009-08-05 18:05 ` uros at gcc dot gnu dot org 2009-08-05 21:17 ` uros at gcc dot gnu dot org 2009-08-05 21:19 ` ubizjak at gmail dot com
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