From: Jakub Jelinek <jakub@redhat.com>
To: Vladimir Makarov <vmakarov@redhat.com>
Cc: "gcc.gcc.gnu.org" <gcc@gcc.gnu.org>
Subject: Re: Comparison of GCC-4.6.1 and LLVM-2.9 on x86/x86-64 targets
Date: Thu, 08 Sep 2011 08:47:00 -0000 [thread overview]
Message-ID: <20110908084738.GN27949@sunsite.ms.mff.cuni.cz> (raw)
In-Reply-To: <4E678A9B.3040303@redhat.com>
On Wed, Sep 07, 2011 at 11:15:39AM -0400, Vladimir Makarov wrote:
> This year I used -Ofast -flto -fwhole-program instead of
> -O3 for GCC and -O3 -ffast-math for LLVM for comparison of peak
> performance. I could improve GCC performance even more by using
> other GCC possibilities (like support of AVX insns, Graphite optimizations
> and even some experimental stuff like LIPO) but I wanted to give LLVM
> some chances too. Probably an experienced user in LLVM could improve
> LLVM performance too. So I think it is a fair comparison.
-march=native in addition would be nice to see, that can make significant
difference, especially on AVX capable CPUs. I guess LLVM equivalent would
be -march=corei7 -mtune=corei7 and, if it works, -mavx too (though, the only
time I've tried LLVM 2.9 it crashed on almost anything with -mavx).
Jakub
next prev parent reply other threads:[~2011-09-08 8:47 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-07 15:16 Vladimir Makarov
2011-09-07 15:29 ` Duncan Sands
2011-09-07 16:59 ` Vladimir Makarov
2011-09-07 15:55 ` Xinliang David Li
2011-09-07 16:24 ` Vladimir Makarov
2011-09-08 8:23 ` Richard Guenther
2011-09-08 9:22 ` Duncan Sands
2011-09-09 14:02 ` Vladimir Makarov
2011-09-07 17:01 ` Duncan Sands
2011-09-08 8:47 ` Jakub Jelinek [this message]
2011-09-09 14:26 ` Vladimir Makarov
2011-09-09 14:36 ` Jakub Jelinek
2011-09-09 23:30 ` Lawrence Crowl
2011-09-10 13:22 ` Gabriel Dos Reis
2011-09-12 16:40 ` Vladimir Makarov
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