Subject: Re: RFC: [2.6 patch] better i386 CPU selection
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Adrian Bunk <bunk@fs.tum.de>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
In-Reply-To: <20030911062816.GX27368@fs.tum.de>
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Date: Thu, 11 Sep 2003 15:25:10 +0100
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On Iau, 2003-09-11 at 07:28, Adrian Bunk wrote:
> - Does the Cyrix III support 686 instructions?

Original Cyrix III supports the IA32 P6 definition
VIA C3 supports the IA32 P6 definition
The later ones also support cmov (the gcc i686 definition)

They run 486 scheduling better it seems because its a single issue
machine. Turn off the padding tho.

> - Do -march=winchip{2,-c6} and -march=c3{,-2} add anything not in
>   -march=i686 (except optimizations of otherwise compatible code)?

Its i586 ish (but runs best with 486 code kept compact as with the C3).
It lacks some bits of Pentium (lot of profiling, appendix H type stuff)
but is 586 + optional extras in other areas.

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