Message-Id: <36AA1508.95AFE993@cableol.co.uk>
Date: Sat, 23 Jan 1999 18:29:28 +0000
From: Allens <allen DOT asjp AT cableol DOT co DOT uk>
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To: djgpp AT delorie DOT com
Subject: Re: Pentium II optimizations
References: <36A785C1 DOT 24F8BFD AT club-internet DOT fr>
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Reply-To: djgpp AT delorie DOT com

Unless I have missed something *big* a PII is just a combination of a P PRO
(on-chip level 2 cache) and MMX, so the only optimisations you can do are the
mmx ones, and lots and lots of register variables to fill up that 512Kb level 2
cache (Which AFAIK O2+ does for you).  I'm not sure whether pgcc has any mmx
specific code, I have a feeling it doesn't.

			Peter Allen
Viper Arrakyd wrote:
> 
> Hi everybody
> 
> I would like to know what are the best compiler/switches to compile code
> for a pentium II ?
> 
> Compiled with GCC 2.8.1 my program runs at 25 fps.
> With PGCC and the same switches (-mpentium -O6) it drops at 15 !!!
> 
> Does GCC 2.8.1 produce more "Pentium II friendly" code ?
> Can Egcs help ?
> 
> I hope my english isn't too difficult to understand.
> 
> I use Allegro for my program. The library is compiled with the same
> compiler with pentium optimizations on.
> 
> Can anyone help ?