Date: Tue, 2 Feb 1999 18:50:54 -0500
Message-Id: <199902022350.SAA14525@envy.delorie.com>
From: DJ Delorie <dj AT delorie DOT com>
To: djgpp AT delorie DOT com
In-reply-to: <36B763FB.66C8@erols.com> (johnfine@erols.com)
Subject: Re: ASM - function: what should be pushed?
References: <Pine DOT SUN DOT 3 DOT 91 DOT 990201085530 DOT 27193D AT is> <36B64AA2 DOT DDD7B659 AT cartsys DOT com> <36B64EBA DOT 6D55 AT erols DOT com> <199902020148 DOT UAA06492 AT envy DOT delorie DOT com> <36B763FB DOT 66C8 AT erols DOT com>
Reply-To: djgpp AT delorie DOT com


> > ax,cx,dx,sp,st0-7,sw,cw - can be used without saving
> 
>   sp?  Well we all know esp is its own special case and
> its behavior in standard "C" calling conventions is
> clear.  I find it strange that you would class it with
> ax,cx,dx.

I suppose it should be in the bx,si,di,bp list, then.  Is anyone
writing this down?  ;-)

> > bx,si,di,bp - must be preserved

> > gs - used by libc, but need not be preserved if you change it
> 
>   "used by libc":  Used and preserved?  or Used and not preserved?

libc does not attempt to preserve gs when it uses it.  It's in the
ax,cx,dx category.