Message-ID: <3E4B442E.6B87CC24@yahoo.com>
Date: Thu, 13 Feb 2003 02:07:26 -0500
From: CBFalconer <cbfalconer AT yahoo DOT com>
Organization: Ched Research
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To: djgpp-workers AT delorie DOT com
Subject: Re: _rdtsc proposal
References: <10302130355 DOT AA21095 AT clio DOT rice DOT edu>
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Reply-To: djgpp-workers AT delorie DOT com

Charles Sandmann wrote:
> 
> Given the FAQ nature of rdtsc; given the potential to use this in libc;
> for your amusement and comments.  Patterned after farptr.h.  When
> used inline for timing generates the single assembly instruction with
> no additional overhead (cool for timing small C sections).  If OK,
> also will add makefile entry and docs.  Yes I know it can kill
> some CPUs - that will be in the docs with an example how to work
> around it. ... snip ...

What I worry about is that the instruction will slip into
something critical or other, and just lie there until someone with
a 486 (like me) tries to use it.  It should be hard to access it,
and the access should only be via a routine that can protect it. 
So timer resolution falls - tough.

-- 
Chuck F (cbfalconer AT yahoo DOT com) (cbfalconer AT worldnet DOT att DOT net)
   Available for consulting/temporary embedded and systems.
   <http://cbfalconer.home.att.net>  USE worldnet address!