Bug 37462 - [4..4 Regression] Revision 140030 caused >10% 176.gcc regression
Summary: [4..4 Regression] Revision 140030 caused >10% 176.gcc regression
Status: RESOLVED INVALID
Alias: None
Product: gcc
Classification: Unclassified
Component: target (show other bugs)
Version: 4.4.0
: P3 normal
Target Milestone: ---
Assignee: Not yet assigned to anyone
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2008-09-10 14:36 UTC by H.J. Lu
Modified: 2008-09-10 16:48 UTC (History)
5 users (show)

See Also:
Host:
Target: x86_64-unknown-linux-gnu
Build:
Known to work:
Known to fail:
Last reconfirmed:

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Description H.J. Lu 2008-09-10 14:36:04 UTC 
Revision 140030 caused >10% 176.gcc performance regression
in SPEC CPU 2000 on Intel Core 2 running Linux/x86-64 with
-O2 -ffast-math.
Comment 1 H.J. Lu 2008-09-10 14:59:56 UTC 
Honza suggested that

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This mostl likely mean that your glibc has slow memset implementation.
I saw similar drop on SPEC2000 GCC and Debian machines used by
compilation farm.  I was told that FSF glibc was finally updated with
new GCC so hopefully this problem is solved now.

Our (Opteron based) SPEC2006 tester seems fine
http://gcc.opensuse.org/SPEC/CINT/sb-balakirew-head-64-2006/403_gcc_big.png
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I will verify it on Fedora 9.
Comment 2 H.J. Lu 2008-09-10 16:48:27 UTC 
I verified that on Fedora 9 there is no regression between
revision 140029 and 140030 on Intel Core 2.
Comment 3 H.J. Lu 2008-09-10 16:48:52 UTC 
Works on Fedora 9.