[Numpy-discussion] re: gcc 3.0 vs. 2.95.2
europax at home.com
Sun Sep 16 10:33:01 EDT 2001
Peter Soendergaard wrote:
> I just browsed over the archives for Numpy-discussion and saw this, and
> decided to sign up.
> I work on the ATLAS-project http://math-atlas.sourceforge.net/ and we have
> had similar problems with gcc3.0 Gcc 3.0 has a completely new backend
> which produces much slower floating point code on i386 machines. It is
> most visible on the Athlon, but it also also shows on on P4 and PIII
> machines. We havn't yet figured out if there are some optimizations that
> can make this go away, but if you need performance stick with the old 2.95
> release for now.
> By the way, if you would like to use Atlas in NumPy (I don't know if you
> do it already) I might be of some help. There is c-interfaces to the BLAS
> bundled with ATLAS, supporting both row-major and column-major storage.
> FROM: Rob
> DATE: 09/04/2001 18:02:05
> SUBJECT: [Numpy-discussion] Python and Numpy compiled on Athlon
> optimized gcc3.01
> Just for kicks last night I installed gcc3.01 which claims to have Athlon
> optimization, ie. -march=athlon. I recompiled Python and Numpy, and then
> ran a big simulation. The new compiler ran 200 seconds slower than the
> old gcc2.95 with plain -march=pentium. I need to go to the gcc website
> and see just what optimization they are claiming. Maybe I should have
> also used -02. Rob.
> The Numeric Python EM Project
> Numpy-discussion mailing list
> Numpy-discussion at lists.sourceforge.net
Hi Peter, great to know that I'm not alone. Maybe I can build an EM
simulator using all integer math :). I think I mentioned this on the
list before, but Win2k on my laptop (1Ghz) runs Numpy and Python faster
than my 1.2Ghz Athlon DDR machine using FreeBSD :( Also, for
reference, I have a 3DNow optimized MP3encoding program Gogo that
encodes mp3's 10x faster on the athlon than Lame does on my FreeBSD
system on the laptop. Go figure!
The Numeric Python EM Project
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