Date: Sat, 15 Nov 1997 18:08:54 +0000 (   )
From: "Gurunandan R. Bhat" <grbhat AT unigoa DOT ernet DOT in>
To: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
Cc: Johan Levin <johan AT technologist DOT com>, djgpp AT delorie DOT com
Subject: Re: GAS segment override
In-Reply-To: <Pine.SUN.3.91.971116133521.358C-100000@is>
Message-Id: <Pine.LNX.3.91.971115180305.1292A-100000@aditya.unigoa.ernet.in>
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Precedence: bulk



On Sun, 16 Nov 1997, Eli Zaretskii wrote:

> > 	cs
> > 	movw	___djgpp_ds_alias, %ds
> 
> Please note that AFIK, using segment overrides with Gas is dangerous,
> as the DJGPP FAQ explains in section 17.2.

In the very *few* gas programs that I have written, I have checked the 
list file *each* time and found that a override on a single line always 
produced the .byte 0x??. 

I was under the (probably mistaken) impression that the segment override 
bug surfaces only if you include it as a part of the operand for example

movw 	%cs:_ds_alias, %ds	; is known to be problematic

> If the latest versions of Gas don't have this problem, please tell me
> and I will amend the FAQ.  But please make *very* sure that the
> problem was fixed, because it can produxe very nasty bugs.

Is there any way to be *very* sure without going throgh the Gas source. 
If there is, I would be happy to volunteer :)