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* [Bug tree-optimization/58520] New: GCC fails to vectorize loop
@ 2013-09-24 15:03 burnus at gcc dot gnu.org
2013-09-24 15:04 ` [Bug tree-optimization/58520] " burnus at gcc dot gnu.org
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: burnus at gcc dot gnu.org @ 2013-09-24 15:03 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58520
Bug ID: 58520
Summary: GCC fails to vectorize loop
Product: gcc
Version: 4.9.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: burnus at gcc dot gnu.org
Created attachment 30886
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=30886&action=edit
C test case
On Intel(R) Xeon(R) CPU E5-2630, the following code doesn't vectorize with GCC
4.9 - but it does with ICC:
for (yi = 0; yi < ycount - 1; ++yi)
yheight[yi] = ybins[yi+1] - ybins[yi];
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/58520] GCC fails to vectorize loop
2013-09-24 15:03 [Bug tree-optimization/58520] New: GCC fails to vectorize loop burnus at gcc dot gnu.org
@ 2013-09-24 15:04 ` burnus at gcc dot gnu.org
2013-09-24 15:09 ` burnus at gcc dot gnu.org
2013-09-24 15:18 ` paolo.carlini at oracle dot com
2 siblings, 0 replies; 4+ messages in thread
From: burnus at gcc dot gnu.org @ 2013-09-24 15:04 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58520
--- Comment #1 from Tobias Burnus <burnus at gcc dot gnu.org> ---
Created attachment 30887
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=30887&action=edit
Assembler generated by ICC
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/58520] GCC fails to vectorize loop
2013-09-24 15:03 [Bug tree-optimization/58520] New: GCC fails to vectorize loop burnus at gcc dot gnu.org
2013-09-24 15:04 ` [Bug tree-optimization/58520] " burnus at gcc dot gnu.org
@ 2013-09-24 15:09 ` burnus at gcc dot gnu.org
2013-09-24 15:18 ` paolo.carlini at oracle dot com
2 siblings, 0 replies; 4+ messages in thread
From: burnus at gcc dot gnu.org @ 2013-09-24 15:09 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58520
Tobias Burnus <burnus at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution|--- |INVALID
--- Comment #2 from Tobias Burnus <burnus at gcc dot gnu.org> ---
INVALID.
Pilot error - I had -fsanitize=address in use. Still, I have another example,
which still fails.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/58520] GCC fails to vectorize loop
2013-09-24 15:03 [Bug tree-optimization/58520] New: GCC fails to vectorize loop burnus at gcc dot gnu.org
2013-09-24 15:04 ` [Bug tree-optimization/58520] " burnus at gcc dot gnu.org
2013-09-24 15:09 ` burnus at gcc dot gnu.org
@ 2013-09-24 15:18 ` paolo.carlini at oracle dot com
2 siblings, 0 replies; 4+ messages in thread
From: paolo.carlini at oracle dot com @ 2013-09-24 15:18 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58520
--- Comment #3 from Paolo Carlini <paolo.carlini at oracle dot com> ---
By the way, I think that saying which specific command line options you are
using is *much* more important than providing CPU brand and model, because the
optimizers do not magically divine what you hardware exactly supports (like,
eg, availability of vector instructions, etc) just assume by default a very
outdated Pentium-class CPU. Sorry, I pointed out something obvious, but
somebody may find it useful to know.
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2013-09-24 15:18 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2013-09-24 15:03 [Bug tree-optimization/58520] New: GCC fails to vectorize loop burnus at gcc dot gnu.org
2013-09-24 15:04 ` [Bug tree-optimization/58520] " burnus at gcc dot gnu.org
2013-09-24 15:09 ` burnus at gcc dot gnu.org
2013-09-24 15:18 ` paolo.carlini at oracle dot com
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