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* [Bug pending/23378] New: code quality regression for complicated loop
@ 2005-08-13 18:03 martin at mpa-garching dot mpg dot de
2005-08-13 18:05 ` [Bug pending/23378] " martin at mpa-garching dot mpg dot de
` (4 more replies)
0 siblings, 5 replies; 10+ messages in thread
From: martin at mpa-garching dot mpg dot de @ 2005-08-13 18:03 UTC (permalink / raw)
To: gcc-bugs
A code quality regression was introduced into CVS between the timestamps
"-D 20050729 22:00:00 UT" and "-D 20050729 23:00:00 UT". It appears that
it iss caused by Jan Hubicka's patch from
http://gcc.gnu.org/ml/gcc-patches/2005-07/msg02021.html
If the attached testcase is compiled with the newer compiler, the runtime
of the generated executable is more than 50 per cent higher:
old compiler:
~/tmp/tmp2>g++ -O3 -march=pentium4 -mfpmath=sse testcase.cc
~/tmp/tmp2>time ./a.out
14.250u 0.020s 0:14.27 100.0% 0+0k 0+0io 205pf+0w
new compiler:
~/tmp/tmp2>g++ -O3 -march=pentium4 -mfpmath=sse testcase.cc
~/tmp/tmp2>time ./a.out
22.430u 0.030s 0:22.46 100.0% 0+0k 0+0io 205pf+0w
Both compilers have the same "g++ -v" output:
~/tmp/tmp2>g++ -v
Using built-in specs.
Target: i686-pc-linux-gnu
Configured with: /scratch/gcc/configure --quiet
--prefix=/afs/mpa/data/martin/ugcc --enable-languages=c++
--enable-mapped-location --disable-checking
Thread model: posix
gcc version 4.1.0 20050729 (experimental)
The hot spot of the code is the strange "loop" in lines 134-139
of alm_map_tools_orig.cc.
--
Summary: code quality regression for complicated loop
Product: gcc
Version: 4.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: pending
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: martin at mpa-garching dot mpg dot de
CC: gcc-bugs at gcc dot gnu dot org,martin at mpa-garching
dot mpg dot de
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=23378
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug pending/23378] code quality regression for complicated loop
2005-08-13 18:03 [Bug pending/23378] New: code quality regression for complicated loop martin at mpa-garching dot mpg dot de
@ 2005-08-13 18:05 ` martin at mpa-garching dot mpg dot de
2005-08-13 18:06 ` [Bug target/23378] [4.1 Regression] " pinskia at gcc dot gnu dot org
` (3 subsequent siblings)
4 siblings, 0 replies; 10+ messages in thread
From: martin at mpa-garching dot mpg dot de @ 2005-08-13 18:05 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From martin at mpa-garching dot mpg dot de 2005-08-13 18:05 -------
Created an attachment (id=9494)
--> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=9494&action=view)
A testcase for the problem
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23378
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug target/23378] [4.1 Regression] code quality regression for complicated loop
2005-08-13 18:03 [Bug pending/23378] New: code quality regression for complicated loop martin at mpa-garching dot mpg dot de
2005-08-13 18:05 ` [Bug pending/23378] " martin at mpa-garching dot mpg dot de
@ 2005-08-13 18:06 ` pinskia at gcc dot gnu dot org
2005-08-14 13:57 ` steven at gcc dot gnu dot org
` (2 subsequent siblings)
4 siblings, 0 replies; 10+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2005-08-13 18:06 UTC (permalink / raw)
To: gcc-bugs
--
What |Removed |Added
----------------------------------------------------------------------------
CC| |hubicka at gcc dot gnu dot
| |org
Component|pending |target
Summary|code quality regression for |[4.1 Regression] code
|complicated loop |quality regression for
| |complicated loop
Target Milestone|--- |4.1.0
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23378
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug target/23378] [4.1 Regression] code quality regression for complicated loop
2005-08-13 18:03 [Bug pending/23378] New: code quality regression for complicated loop martin at mpa-garching dot mpg dot de
2005-08-13 18:05 ` [Bug pending/23378] " martin at mpa-garching dot mpg dot de
2005-08-13 18:06 ` [Bug target/23378] [4.1 Regression] " pinskia at gcc dot gnu dot org
@ 2005-08-14 13:57 ` steven at gcc dot gnu dot org
2005-08-14 14:07 ` pinskia at gcc dot gnu dot org
2005-08-16 8:38 ` martin at mpa-garching dot mpg dot de
4 siblings, 0 replies; 10+ messages in thread
From: steven at gcc dot gnu dot org @ 2005-08-14 13:57 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From steven at gcc dot gnu dot org 2005-08-14 13:57 -------
Ouch. This badly needs reducing...
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23378
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug target/23378] [4.1 Regression] code quality regression for complicated loop
2005-08-13 18:03 [Bug pending/23378] New: code quality regression for complicated loop martin at mpa-garching dot mpg dot de
` (2 preceding siblings ...)
2005-08-14 13:57 ` steven at gcc dot gnu dot org
@ 2005-08-14 14:07 ` pinskia at gcc dot gnu dot org
2005-08-16 8:38 ` martin at mpa-garching dot mpg dot de
4 siblings, 0 replies; 10+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2005-08-14 14:07 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From pinskia at gcc dot gnu dot org 2005-08-14 14:06 -------
I think this is related to PR 23302 and PR 23303 since those look like they were caused by the same
patch.
--
What |Removed |Added
----------------------------------------------------------------------------
BugsThisDependsOn| |23302, 23303
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23378
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug target/23378] [4.1 Regression] code quality regression for complicated loop
2005-08-13 18:03 [Bug pending/23378] New: code quality regression for complicated loop martin at mpa-garching dot mpg dot de
` (3 preceding siblings ...)
2005-08-14 14:07 ` pinskia at gcc dot gnu dot org
@ 2005-08-16 8:38 ` martin at mpa-garching dot mpg dot de
4 siblings, 0 replies; 10+ messages in thread
From: martin at mpa-garching dot mpg dot de @ 2005-08-16 8:38 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From martin at mpa-garching dot mpg dot de 2005-08-16 08:33 -------
(In reply to comment #2)
> Ouch. This badly needs reducing...
Absolutely. But since Andrew pointed out that it is probably related to PR 23302
and PR 23303 (which have nice testcases), I suggest I wait until these are fixed.
If, after that, the performance regression persists, I'll try to reduce the
testcase. Is that OK?
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23378
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug target/23378] [4.1 Regression] code quality regression for complicated loop
[not found] <bug-23378-2736@http.gcc.gnu.org/bugzilla/>
` (2 preceding siblings ...)
2005-10-31 18:24 ` hubicka at gcc dot gnu dot org
@ 2005-11-01 10:23 ` martin at mpa-garching dot mpg dot de
3 siblings, 0 replies; 10+ messages in thread
From: martin at mpa-garching dot mpg dot de @ 2005-11-01 10:23 UTC (permalink / raw)
To: gcc-bugs
------- Comment #7 from martin at mpa-garching dot mpg dot de 2005-11-01 10:22 -------
The regression is unfortunately still there :(
Reducing the testcase is really hard, and I have some indications
that the problem vanishes if there is less work to do in the critical loop.
If you have any suggestion how to proceed, they would be greatly appreciated
...
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23378
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug target/23378] [4.1 Regression] code quality regression for complicated loop
[not found] <bug-23378-2736@http.gcc.gnu.org/bugzilla/>
2005-10-16 22:42 ` pinskia at gcc dot gnu dot org
2005-10-31 5:01 ` mmitchel at gcc dot gnu dot org
@ 2005-10-31 18:24 ` hubicka at gcc dot gnu dot org
2005-11-01 10:23 ` martin at mpa-garching dot mpg dot de
3 siblings, 0 replies; 10+ messages in thread
From: hubicka at gcc dot gnu dot org @ 2005-10-31 18:24 UTC (permalink / raw)
To: gcc-bugs
------- Comment #6 from hubicka at gcc dot gnu dot org 2005-10-31 18:24 -------
I don't have P4 to test handy. Can you re-test whether fixing 23302 (23303 is
invalid) make any difference?
I doubt these two make actual runtime changes - the sequence would translate to
same uops for P4 and should execute in about the same time.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23378
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug target/23378] [4.1 Regression] code quality regression for complicated loop
[not found] <bug-23378-2736@http.gcc.gnu.org/bugzilla/>
2005-10-16 22:42 ` pinskia at gcc dot gnu dot org
@ 2005-10-31 5:01 ` mmitchel at gcc dot gnu dot org
2005-10-31 18:24 ` hubicka at gcc dot gnu dot org
2005-11-01 10:23 ` martin at mpa-garching dot mpg dot de
3 siblings, 0 replies; 10+ messages in thread
From: mmitchel at gcc dot gnu dot org @ 2005-10-31 5:01 UTC (permalink / raw)
To: gcc-bugs
------- Comment #5 from mmitchel at gcc dot gnu dot org 2005-10-31 05:01 -------
Leaving as P2.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23378
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug target/23378] [4.1 Regression] code quality regression for complicated loop
[not found] <bug-23378-2736@http.gcc.gnu.org/bugzilla/>
@ 2005-10-16 22:42 ` pinskia at gcc dot gnu dot org
2005-10-31 5:01 ` mmitchel at gcc dot gnu dot org
` (2 subsequent siblings)
3 siblings, 0 replies; 10+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2005-10-16 22:42 UTC (permalink / raw)
To: gcc-bugs
--
pinskia at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Severity|normal |minor
GCC build triplet|i686-pc-linux-gnu |
GCC host triplet|i686-pc-linux-gnu |
GCC target triplet|i686-pc-linux-gnu |i?86-*-*
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23378
^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2005-11-01 10:23 UTC | newest]
Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2005-08-13 18:03 [Bug pending/23378] New: code quality regression for complicated loop martin at mpa-garching dot mpg dot de
2005-08-13 18:05 ` [Bug pending/23378] " martin at mpa-garching dot mpg dot de
2005-08-13 18:06 ` [Bug target/23378] [4.1 Regression] " pinskia at gcc dot gnu dot org
2005-08-14 13:57 ` steven at gcc dot gnu dot org
2005-08-14 14:07 ` pinskia at gcc dot gnu dot org
2005-08-16 8:38 ` martin at mpa-garching dot mpg dot de
[not found] <bug-23378-2736@http.gcc.gnu.org/bugzilla/>
2005-10-16 22:42 ` pinskia at gcc dot gnu dot org
2005-10-31 5:01 ` mmitchel at gcc dot gnu dot org
2005-10-31 18:24 ` hubicka at gcc dot gnu dot org
2005-11-01 10:23 ` martin at mpa-garching dot mpg dot de
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