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Mail Archives: djgpp/2001/07/25/05:44:29

Message-ID: <5BF60CD649EDD411A04600B0D049F53AFFA93B@hydmail02.hyd.wilco-int.com>
From: Prashant Ramachandra <rprash AT wilco-int DOT com>
To: "'djgpp AT delorie DOT com'" <djgpp AT delorie DOT com>
Subject: RE: Cpu speed detection using DJGPP?
Date: Wed, 25 Jul 2001 15:03:30 +0530
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Reply-To: djgpp AT delorie DOT com

On Wednesday, July 25, 2001 1:17 PM, kallekula60 AT hotmail DOT com
[SMTP:kallekula60 AT hotmail DOT com] wrote:
> Thanks for all the replies! This is what I came up with and it
> seems
> too work fine on my K6-2 computers.

Blind interation loops might be optimized by some CPUs, so in effect it
won't execute those 10000 times. So, it's better that you do something like:

movl $1, %eax;
xorl %eax, %eax;
xorl %eax, %eax;
xorl %eax, %eax;
xorl %eax, %eax;
xorl %eax, %eax;
xorl %eax, %eax;
....// Around 500-1000 lines of this.

and run the loop a few times. That produces reliable results according to
some of the tests I've done on different CPUs.
--
Prashant TR <tr AT midpec DOT com>  Web: http://www.midpec.com/

"Those who do not understand Unix are condemned to reinvent it, poorly."
     -- Henry Spencer

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