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From: "howarth.at.gcc at gmail dot com" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug libgomp/61333] New: potential target specific performance issue with libgomp Date: Tue, 27 May 2014 23:58:00 -0000 [thread overview] Message-ID: <bug-61333-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61333 Bug ID: 61333 Summary: potential target specific performance issue with libgomp Product: gcc Version: 4.9.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: libgomp Assignee: unassigned at gcc dot gnu.org Reporter: howarth.at.gcc at gmail dot com CC: jakub at gcc dot gnu.org While benchmarking the new openmp/clang-omp support against gcc/libgomp on x86_64-apple-darwin13, I noticed a potential performance issue in gcc/libgomp on darwin. Using the attached heated_plate_openmp.c and heated_plate_gcc.sh shell script, I am seeing reproducible timing on darwin that ratio to the timing for one thread as.. gcc 4.8.3 1:1.90:3.31 gcc 4.9.0 1:1.90:3.30 clang 2.4 1:1.99:3.71 compared to Fedora 15 linux gcc 4.6.3 1:1.99:3.92 This is where the timings for the one, two and four OMP processes are normalized to the timing for one OMP process. Unfortunately I don't have access to gcc 4.8.3 or 4.9.0 to test on linux. The timings are reproducible and suggest that darwin may have a performance issue for higher number of OMP threads.
next reply other threads:[~2014-05-27 23:58 UTC|newest] Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top 2014-05-27 23:58 howarth.at.gcc at gmail dot com [this message] 2014-05-27 23:58 ` [Bug libgomp/61333] " howarth.at.gcc at gmail dot com 2014-05-27 23:59 ` howarth.at.gcc at gmail dot com 2014-05-28 0:04 ` howarth.at.gcc at gmail dot com 2014-05-28 0:18 ` pinskia at gcc dot gnu.org 2014-05-28 0:35 ` howarth.at.gcc at gmail dot com 2014-05-28 0:52 ` howarth.at.gcc at gmail dot com 2014-05-28 0:57 ` pinskia at gcc dot gnu.org 2014-05-28 9:49 ` dominiq at lps dot ens.fr 2014-05-28 9:59 ` dominiq at lps dot ens.fr 2014-05-28 10:10 ` jakub at gcc dot gnu.org 2014-05-28 13:02 ` howarth.at.gcc at gmail dot com 2014-05-28 13:36 ` dominiq at lps dot ens.fr 2014-05-28 15:14 ` howarth.at.gcc at gmail dot com 2014-05-28 17:30 ` howarth.at.gcc at gmail dot com
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