From: Loic Dachary <loic@dachary.org>
To: Laurent Guerby <laurent@guerby.net>, Kevin Greenan <kmgreen2@gmail.com>
Cc: Ceph Development <ceph-devel@vger.kernel.org>
Subject: GCC -msse2 portability question
Date: Sun, 23 Mar 2014 20:50:38 +0100 [thread overview]
Message-ID: <532F3B0E.2050204@dachary.org> (raw)
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Hi Laurent,
In the context of optimizing erasure code functions implemented by Kevin Greenan (cc'ed) and James Plank at https://bitbucket.org/jimplank/gf-complete/ we ran accross a question you may have the answer to: can gcc -msse2 (or -msse* for that matter ) have a negative impact on the portability of the compiled binary code ?
In other words, if a code is compiled without -msse* and runs fine on all intel processors it targets, could it be that adding -msse* to the compilation of the same source code generate a binary that would fail on some processors ? This is assuming no sse specific functions were used in the source code.
In gf-complete, all sse specific instructions are carefully protected to not be run on a CPU that does not support them. The runtime detection is done by checking CPU id bits ( see https://bitbucket.org/jimplank/gf-complete/pull-request/7/probe-intel-sse-features-at-runtime/diff#Lsrc/gf_intel.cT28 )
The corresponding thread is at:
https://bitbucket.org/jimplank/gf-complete/pull-request/4/defer-the-decision-to-use-a-given-sse/diff#comment-1479296
Cheers
--
Loïc Dachary, Artisan Logiciel Libre
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next reply other threads:[~2014-03-23 19:50 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-23 19:50 Loic Dachary [this message]
2014-03-23 22:34 ` GCC -msse2 portability question Laurent GUERBY
2014-03-24 21:27 ` Loic Dachary
2014-03-25 9:43 ` Laurent GUERBY
2014-03-25 9:56 ` Loic Dachary
2014-03-25 11:22 ` Laurent GUERBY
2014-03-25 14:44 ` Milosz Tanski
2014-03-25 18:45 ` Loic Dachary
2014-03-24 1:40 ` Sage Weil
2014-03-25 19:08 ` Loic Dachary
[not found] ` <CA+AFVBhpOZEPehsd4qHCBr4aRzv60ZW8LzRwKsduUrZmLV1wxQ@mail.gmail.com>
2014-03-25 19:21 ` Loic Dachary
2014-03-25 19:46 ` Milosz Tanski
[not found] ` <CA+AFVBgOEz8_fv9H-8_kOuVSJNL3KQ+36b5kscfjnRMs09DZ6Q@mail.gmail.com>
[not found] ` <53327E59.7060408@dachary.org>
[not found] ` <CANP1eJG9xoCPkFs19KXG1RPUqc-D3aO_0SBOM=4WWFRN2JtX=g@mail.gmail.com>
2014-03-26 18:24 ` Loic Dachary
[not found] ` <CANP1eJErc4qnRhtOCs=Cnh6VNtihLVcZxB1PSCQjpH0sFDBuWA@mail.gmail.com>
2014-03-26 22:13 ` Loic Dachary
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