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Date: Tue, 27 Nov 2007 15:51:00 -0000
From: "J.C. Pizarro" <jcpiza@gmail.com>
To: "Howard Chu" <hyc@highlandsun.com>, gcc@gcc.gnu.org
Subject: Re: [Fwd: performance with gcc -O0/-O2]
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For your Opteron, try with this option

-O3 -fomit-frame-pointer -march=k8 -funroll-loops -finline-functions
-fpeel-loops \
-mno-sse3 -msse2 -msse -mno-mmx -mno-3dnow

The Opteron hardware said that it's better to use SSE2 than SSE3.
The MMX and 3DNow!+ instructions are shorter and older than SSE2/SSE
instructions.

Sincerely, J.C.Pizarro