Newsgroups:	comp.os.msdos.djgpp
From:	Peter Berdeklis <peter AT atmosp DOT physics DOT utoronto DOT ca>
Subject:	Re: MMX
Message-ID:	<Pine.SGI.3.91.970307133506.1145A-100000@atmosp.physics.utoronto.ca>
Nntp-Posting-Host:	chinook.physics.utoronto.ca
Sender:	news AT info DOT physics DOT utoronto DOT ca (System Administrator)
Mime-Version:	1.0
Organization:	University of Toronto - Dept. of Physics
In-Reply-To:	<m0w1tfQ-000S1pC@natacha.inti.edu.ar>
Date:	Fri, 7 Mar 1997 18:38:25 GMT
References:	<m0w1tfQ-000S1pC AT natacha DOT inti DOT edu DOT ar>
Lines:	21
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

On Tue, 4 Mar 1997, Salvador Eduardo Tropea (SET) wrote:
> * If you want to use MMX at 100%, you must make one of 2 things:
> A) Make a very specialized optimizer, is really hard.
> B) Make an extention of the C language, but will be totally non-standard.
> 
[snip]
>   
>   If somebody makes that in the (B) fashion the best way is the use of 
> #pragmas but even with that is very hard because the compiler must see the 
> parallel operations and how to pack it in parallel MMX operations, plus the 
> fact that Intel is using FPU registers for that ... 

If these extensions to C are written they would likely be written in hand
coded/massaged inline asm.  In that case the compiler doesn't need to know
anything about packing and parallel op's, just which registers are 
invalid (eg. the whole FPU stack).

---------------
Peter Berdeklis
Dept. of Physics, Univ. of Toronto

- Raw text -