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Re: changing "configure" to default to "gcc -g -O2 -fwrapv ..."
- From: "Seongbae Park" <seongbae dot park at gmail dot com>
- To: "Daniel Berlin" <dberlin at dberlin dot org>
- Cc: "Richard Guenther" <richard dot guenther at gmail dot com>, "Paul Eggert" <eggert at cs dot ucla dot edu>, autoconf-patches at gnu dot org, bug-gnulib at gnu dot org, gcc at gcc dot gnu dot org
- Date: Sun, 31 Dec 2006 17:54:01 -0800
- Subject: Re: changing "configure" to default to "gcc -g -O2 -fwrapv ..."
- References: <200612300047.kBU0lFwk014817@localhost.localdomain> <10612302258.AA24598@vlsi1.ultra.nyu.edu> <87lkkosz1n.fsf@penguin.cs.ucla.edu> <45970416.80407@adacore.com> <8764bssikm.fsf@penguin.cs.ucla.edu> <571f6b510612310047r3b7ef9acl4a0ab082e88e17a3@mail.gmail.com> <87bqlkmm3r.fsf@penguin.cs.ucla.edu> <4aca3dc20612310641n78e8898euf1c003444e2303eb@mail.gmail.com> <84fc9c000612310645h67066c70vf9eb11af74b639a7@mail.gmail.com> <4aca3dc20612311613r2992db50o851c7d73603b42ef@mail.gmail.com>
On 12/31/06, Daniel Berlin <dberlin@dberlin.org> wrote:
...
> I added -fwrapv to the Dec30 run of SPEC at
> http://www.suse.de/~gcctest/SPEC/CFP/sb-vangelis-head-64/recent.html
> and
> http://www.suse.de/~gcctest/SPEC/CINT/sb-vangelis-head-64/recent.html
Note the distinct drop in performance across almost all the benchmarks
on Dec 30, including popular programs like bzip2 and gzip.
Also, this is only on x86 -
other targets that benefit more from software pipelinine/modulo scheduling
may suffer even more than x86, especially on the FP side.
--
#pragma ident "Seongbae Park, compiler, http://seongbae.blogspot.com";