Date: Wed, 19 May 1999 15:12:04 +0200
To: pgcc AT delorie DOT com
Subject: Re: Benchmark PGCC vs EGCS on a K6-2
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In-Reply-To: <19990519105631.40676@atrey.karlin.mff.cuni.cz>; from Jan Hubicka on Wed, May 19, 1999 at 10:56:31AM +0200
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From: Marc Lehmann <pcg AT goof DOT com>
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On Wed, May 19, 1999 at 10:56:31AM +0200, Jan Hubicka wrote:
> causes performance loss. Author of original K6 stuff for egcs just blindly followed
> their recommendations so many of his changes were performance miss (especially changking
> xor reg,reg to mov reg,0)

I especially rmeember when I put much work into making it possible to
switch "push"-sequences into "sub; mov" for function calls, which was
highly recommended but actually a loss.

> K6 seems to have serious problems with decoding speed. I've made new haifa scheduler hooks for
> decoding that worked quite well (I have also version for Pentium and PPro available, PPro
> version is untested), 
> On K6 it brought quite large speedups (-10 - 500%, usually about 10%), but changes necesarry
> to i386.md are quite large so it would take lots of time to add them into gcc.

Well, pgcc is much more open to these kind of patches...!

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