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Re: Big differences on SpecFP results for gcc and icc
- From: Robert Dewar <dewar at adacore dot com>
- To: Uros Bizjak <uros at kss-loka dot si>
- Cc: gcc at gcc dot gnu dot org, Scott Robert Ladd <scott dot ladd at coyotegulch dot com>
- Date: Sun, 12 Jun 2005 05:46:39 -0400
- Subject: Re: Big differences on SpecFP results for gcc and icc
- References: <42ABFE7C.5040804@kss-loka.si>
Uros Bizjak wrote:
I know that these graphs don't show the results of most aggresive
optimization options for gcc, but that is also the case with icc (only
-O2). However, it looks that gcc and icc are not even in the same class
regarding FP performance. Perhaps there is some critical optimizations,
that are not present in gcc?
Or perhaps icc has spent much more effort in optimizing the spec
tests specifically.
I think I'm not the only person, that finds these results rather
"dissapointing". As Scott is currently writing a paper on gcc's FP
performance, perhaps someone has an explanation, why gcc's results are
so low on Pentium4 for these tests?
I suggest doing more general benchmarks than just the spec tests,
which are rather notorious targets for targetted optimization.
Uros.