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* [Bug c/38518] New: Excessive compile time with -O3
@ 2008-12-13 18:18 dcb314 at hotmail dot com
2008-12-13 18:19 ` [Bug c/38518] " dcb314 at hotmail dot com
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: dcb314 at hotmail dot com @ 2008-12-13 18:18 UTC (permalink / raw)
To: gcc-bugs
I just tried to compile the package fceu-0.98.25-1.7
with the GNU C++ compiler version 4.4 snapshot 20081212.
The compiler appears to get into a long or possibly infinite loop.
I tried compiling with flag -O2 and that took 40 seconds or so.
With flag -O3, compilation did not finish in over seven minutes on
an otherwise idle machine.
Preprocessed source code attached. Flag -O3 required.
--
Summary: Excessive compile time with -O3
Product: gcc
Version: 4.4.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: dcb314 at hotmail dot com
GCC host triplet: suse-linux-x86_64
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38518
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c/38518] Excessive compile time with -O3
2008-12-13 18:18 [Bug c/38518] New: Excessive compile time with -O3 dcb314 at hotmail dot com
@ 2008-12-13 18:19 ` dcb314 at hotmail dot com
2008-12-13 19:52 ` hjl dot tools at gmail dot com
2008-12-14 9:55 ` dcb314 at hotmail dot com
2 siblings, 0 replies; 4+ messages in thread
From: dcb314 at hotmail dot com @ 2008-12-13 18:19 UTC (permalink / raw)
To: gcc-bugs
------- Comment #1 from dcb314 at hotmail dot com 2008-12-13 18:18 -------
Created an attachment (id=16904)
--> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=16904&action=view)
C source code
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38518
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c/38518] Excessive compile time with -O3
2008-12-13 18:18 [Bug c/38518] New: Excessive compile time with -O3 dcb314 at hotmail dot com
2008-12-13 18:19 ` [Bug c/38518] " dcb314 at hotmail dot com
@ 2008-12-13 19:52 ` hjl dot tools at gmail dot com
2008-12-14 9:55 ` dcb314 at hotmail dot com
2 siblings, 0 replies; 4+ messages in thread
From: hjl dot tools at gmail dot com @ 2008-12-13 19:52 UTC (permalink / raw)
To: gcc-bugs
------- Comment #2 from hjl dot tools at gmail dot com 2008-12-13 19:50 -------
On 2.66GHz Cor2 Quad running Fedora 9/x86-64, gcc 4.4 revision 142740 gave:
lake:pts/1[9]> time ./xgcc -B./ -O3 /tmp/bug48.c -S
./xgcc -B./ -O3 /tmp/bug48.c -S 94.39s user 0.98s system 99% cpu 1:35.51 total
lake:pts/1[10]> time ./xgcc -B./ -O2 /tmp/bug48.c -S
./xgcc -B./ -O2 /tmp/bug48.c -S 11.66s user 0.22s system 99% cpu 11.877 total
lake:pts/1[11]> time ./xgcc -B./ -O2 /tmp/bug48.c -S -ftree-vectorize
./xgcc -B./ -O2 /tmp/bug48.c -S -ftree-vectorize 61.16s user 0.73s system 99%
cpu 1:01.92 total
--
hjl dot tools at gmail dot com changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |hjl dot tools at gmail dot
| |com
Status|UNCONFIRMED |RESOLVED
Resolution| |WORKSFORME
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38518
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c/38518] Excessive compile time with -O3
2008-12-13 18:18 [Bug c/38518] New: Excessive compile time with -O3 dcb314 at hotmail dot com
2008-12-13 18:19 ` [Bug c/38518] " dcb314 at hotmail dot com
2008-12-13 19:52 ` hjl dot tools at gmail dot com
@ 2008-12-14 9:55 ` dcb314 at hotmail dot com
2 siblings, 0 replies; 4+ messages in thread
From: dcb314 at hotmail dot com @ 2008-12-14 9:55 UTC (permalink / raw)
To: gcc-bugs
------- Comment #3 from dcb314 at hotmail dot com 2008-12-14 09:52 -------
(In reply to comment #2)
> On 2.66GHz Cor2 Quad running Fedora 9/x86-64, gcc 4.4 revision 142740 gave:
Thanks for the extra information.
I am concerned that the -O3 takes nine times longer than the -O2.
I'd be interested in finding out where that extra time is
being spent. I've had a look at "man gcc" but nothing obvious
is found.
--
dcb314 at hotmail dot com changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|RESOLVED |UNCONFIRMED
Resolution|WORKSFORME |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38518
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2008-12-14 9:55 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2008-12-13 18:18 [Bug c/38518] New: Excessive compile time with -O3 dcb314 at hotmail dot com
2008-12-13 18:19 ` [Bug c/38518] " dcb314 at hotmail dot com
2008-12-13 19:52 ` hjl dot tools at gmail dot com
2008-12-14 9:55 ` dcb314 at hotmail dot com
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