Message-Id: <m0xWLTY-000S2BC@inti.gov.ar>
Comments: Authenticated sender is <salvador AT natacha DOT inti DOT gov DOT ar>
From: "Salvador Eduardo Tropea (SET)" <salvador AT inti DOT edu DOT ar>
Organization: INTI
To: ovek AT arcticnet DOT no (Ove Kaaven), djgpp AT delorie DOT com
Date: Fri, 14 Nov 1997 16:24:25 +0000
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Subject: Re: GAS segment override
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ovek AT arcticnet DOT no (Ove Kaaven) wrote:
> Eli Zaretskii <eliz AT is DOT elta DOT co DOT il> wrote:
> 
> >On Tue, 11 Nov 1997, Johan Levin wrote:
> >
> >> Allegro does it this way:
> >> 	.byte 0x2e
> >> 	movw	___djgpp_ds_alias, %ax
> >> 
> >> But I'd like a neater wayt than to use '.byte'.
> >> '.byte' looks like a temporary solution.
> >
> >It's not temporary, it *is* the solution.  See section 17.2 of the DJGPP 
> >FAQ list (v2/faq210b.zip), it explicitely tells you to do it the Allegro 
> >way (unless you want to get in trouble).
> 
> I doubt. The trouble is with
> 
> mov cs:mem
> 
> not with
> 
> cs        <-- separate and valid instruction
> mov mem
> 
> as far as I know, and using .byte is an unnecessary complication for a
> workaround that is already built-in (the separate "cs" instruction).
> Is this wrong?

In old versions of AS segment override was very buggy and produced too 
much troubles to people like Morten. I don't know if the separated version is 
good enough. The code in headers still using the .byte thing because was made 
for the old  AS. The worst problem was the random faults when using the segment 
override. So if you want to use it, do it, and if after a deep use you 
determine that the bug is finally killed make know it. By now I think that 
people wanting to avoid problems (they can appear when compiling the code with 
djgpp v2.0+BNU 2.7) must use the byte workaround.

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