From: Charles Sandmann <sandmann AT new-orleans DOT NeoSoft DOT com>
Subject: Re: stack segment
To: dj AT stealth DOT ctron DOT com (DJ Delorie)
Date: Mon, 21 Nov 1994 09:25:39 -0600 (CST)
Cc: baca AT crl DOT ucsd DOT edu, djgpp AT sun DOT soe DOT clarkson DOT edu

> You can safely set SS := DS, but you lose the stack overflow
> protection.  The two selectors map to the same linear starting
> address.  In fact, this "enhancement" does break -fomit-frame-pointer
> mode in gcc, which assumes that you can use SS to point to non-stack
> things, so it may go away and then SS==DS always.

Two other comments:

Due to my design flaw, Coproessor errors under DPMI will not be flagged
if you set SS==DS (its a long story)

Using -fomit-frame-pointer under DPMI will probably cause the machine
to hang if it tries to generate a call frame traceback (the EBP
chain will be garbage).