From owner-freebsd-hackers  Thu Jan 15 09:13:53 1998
Return-Path: <owner-freebsd-hackers@FreeBSD.ORG>
Received: (from majordom@localhost)
          by hub.freebsd.org (8.8.8/8.8.8) id JAA11623
          for hackers-outgoing; Thu, 15 Jan 1998 09:13:53 -0800 (PST)
          (envelope-from owner-freebsd-hackers@FreeBSD.ORG)
Received: from rah.star-gate.com ([209.133.7.178])
          by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id JAA11600
          for <freebsd-hackers@freebsd.org>; Thu, 15 Jan 1998 09:13:42 -0800 (PST)
          (envelope-from hasty@rah.star-gate.com)
Received: from rah.star-gate.com (localhost.star-gate.com [127.0.0.1])
          by rah.star-gate.com (8.8.8/8.8.8) with ESMTP id JAA01877;
          Thu, 15 Jan 1998 09:13:38 -0800 (PST)
          (envelope-from hasty@rah.star-gate.com)
Message-Id: <199801151713.JAA01877@rah.star-gate.com>
X-Mailer: exmh version 2.0gamma 1/27/96
To: Archie Cobbs <archie@whistle.com>
cc: freebsd-hackers@FreeBSD.ORG
Subject: Re: what does MMX mean? 
In-reply-to: Your message of "Wed, 14 Jan 1998 15:55:09 PST."
             <199801142355.PAA05051@bubba.whistle.com> 
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Date: Thu, 15 Jan 1998 09:13:38 -0800
From: Amancio Hasty <hasty@rah.star-gate.com>
Sender: owner-freebsd-hackers@FreeBSD.ORG
Precedence: bulk

> 
> What, exactly, does MMX mean?
> 
> Does it mean the processor has NEW instructions for DSP type operations?
> Does it speed up EXISTING instructions? Integer or floating point (or both)?
> 
> Thanks,
> -Archie
> 

Not sure what it means --- my guess is MultiMedia eXtensions.
It does not speed up integer operations nor floating points in the case
of the latter it actually slows it down. with MMX instructions you can
do things like do a byte-wise add to a long word. The MMX instructions is
more like DSP operations and it was probably designed to speed up codecs
such H.263 and MPEG.

	Cheers,
	Amancio