From:	"John M. Aldrich" <fighteer AT cs DOT com>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: segment overrides
Date:	Wed, 15 Apr 1998 18:45:26 -0400
Organization:	Two pounds of chaos and a pinch of salt.
Lines:	23
Message-ID:	<35353886.6924@cs.com>
References:	<28A3AF71AD2 AT fharga DOT sun DOT ac DOT za>
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To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

lou smith wrote:
> 
> i dont quite understand how segment overrides work..
> does one have call ".byte 0x64" before EVERY SINGLE memory access..
> Does that mean a instruction like  "rep
>                                                 stosl"
> is impossible - because each of those stores should have been
> preceded by a "byte 0x64" bytecode -- requiring an explicit  ecx-type
> loop ???

Of course you don't need that before every memory access; only those
which transfer data to conventional memory using the _farpokeX/_farpeekX
convention.  And you only need the segment override once per looping
construct, as long as you don't call any library code that alters the
value of %fs.

-- 
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|      John M. Aldrich       |"Men rarely (if ever) manage to dream |
|       aka Fighteer I       |up a god superior to themselves. Most |
|   mailto:fighteer AT cs DOT com   |gods have the manners and morals of a |
| http://www.cs.com/fighteer |spoiled child."    - Lazarus Long     |
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