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Re: Optimization: Conclusions from Evolutionary Analysis
- From: Martin Reinecke <martin at MPA-Garching dot MPG dot DE>
- To: gcc at gcc dot gnu dot org
- Cc: hubicka at ucw dot cz, coyote at coyotegulch dot com
- Date: Wed, 19 Nov 2003 11:44:49 +0100
- Subject: Re: Optimization: Conclusions from Evolutionary Analysis
- Organization: Max-Planck-Institut fuer Astrophysik
Jan Hubicka wrote:
> Scott Robert Ladd wrote:
Being stuck with a Pentium 4 (Northwood), I haven't been able to see how
the SSE options affect code on the Opteron. -msse is implied by
-march=pentium4; I've checked this, both in the GCC source code and by
comparing compiles with and without -msse.
Interesting, it looks like we do something terribly wrong for P4.
P4 tunning needs work :( Perhaps I can look into it during stage3.
I can confirm these problems; I'm developing floting-point-intensive
applications on a Pentium 4 and was not able to get any noticeable
performance increases from -march=pentium4 -mfpmath=ss2 (or sse,387 etc.).
Cheers,
Martin