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Wrong Flags

Posted by: Anonymous Coward on April 25, 2006 10:25 PM
As pointed out above, you are using the wrong flags here. You shouldn't be using pentium4 for an AMD64 CPU. Below are a couple of links to the Gentoo forums about this exact topic. If you want sse3 you can explicitly set that flag.



This link tells how to identify what your CPU supports including the fact that sse3 is called pni.
<a href="http://forums.gentoo.org/viewtopic-t-452086-highlight-sse3.html" title="gentoo.org">http://forums.gentoo.org/viewtopic-t-452086-highl<nobr>i<wbr></nobr> ght-sse3.html</a gentoo.org>



This is another link you should read about -march=k8 on a x86_64 CPU.

Highlight: "No, the only flag enabled by -march=k8 is actually -m3dnow. The other flags -mmmx -msse -msse2 and -mfpmath=sse is on by default on x86_64 with or without -march. -msse3 is the only one you have to add explicitly."
<a href="http://forums.gentoo.org/viewtopic-t-415468-highlight-sse3.html" title="gentoo.org">http://forums.gentoo.org/viewtopic-t-415468-highl<nobr>i<wbr></nobr> ght-sse3.html</a gentoo.org>



It's a good attempt but I and many others would like to see you redo this test with the correct flags to see how it really performs.

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