From: Oon Lin <sci-okl AT jcu DOT edu DOT au>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: [Q] Which is faster? ( Confused... )
Date: Sun, 19 Oct 1997 15:54:57 +1000
Organization: University of Queensland
Lines: 46
Message-ID: <Pine.OSF.3.93.971019154815.28709A-100000@sailfish.jcu.edu.au>
References: <628kkv$16c AT usenet DOT kreonet DOT re DOT kr> <34482426 DOT 74D1 AT drao DOT nrc DOT ca>
NNTP-Posting-Host: 137.219.16.28
Mime-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
In-Reply-To: <34482426.74D1@drao.nrc.ca>
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp
Precedence: bulk

On Fri, 17 Oct 1997, tom burgess wrote:

> good AT soback DOT kornet DOT nm DOT kr wrote:
> > 
> > I have a question in DJGPP inline assembly.
> > Among MOVW %AX, %BX, MOVL %EAX, %EBX
> > 
> > This is just about speed, not others.
> > 
> > Thanks in advance.
> 
> On 386 and 486, same speed. On Pentium, 16 bit operations (MOVW) are
> SLOWER. (1 cycle prefix byte penalty, plus additional penalties
> because instruction pairing is disabled)
> 
> 	regards, tom

Hi !

I was browsing through the news group when I came across the above reply..
I'm kinda confused (Hope you can give me some simple explanations...)

I had read somewhere in a computer architecture book that a word would
correspond to the size of the register in a CPU. Since the register size
on a Pentium is 32-bit , wouldn't MOVW be doing a 32-bit operation ?

Or maybe I had confused myself on the actual implementation (assembly) and
architecture ?

Thanks in advance.

Kean

/****************************************************************************/
  Lin Oon Kean
  email : Oon DOT Lin AT jcu DOT edu DOT au
     or : oonkean AT cyberdude DOT com
 
  Kean's Corner In The World Wide Web :
  http://lionfish.jcu.edu.au/~sci-okl
 
  "People are killing the babies , Crying 'Save the Whales Today !' "
                                                        - The Kry
/****************************************************************************/