Re: [RFC] Fix for Go32-v2 native woes

[Eli Zaretskii <eliz at gnu dot org>]

> Date: Tue, 6 Apr 2010 20:41:01 +0200 (CEST)
> From: Mark Kettenis <mark.kettenis@xs4all.nl>
> CC: pierre.muller@ics-cnrs.unistra.fr, gdb-patches@sourceware.org
> 
> > Why do we always read i386-sse.xml or assume that SSE is supported?
> > We should not assume any CPU features by default if there are CPUs out
> > there which we support that don't have them.
> 
> Because that basically was the situation before.

I'm not sure I follow.  GDB 7 builds and works in the DJGPP port
without any trouble, even though SSE support was there before, wasn't
it?

> When SSE support was addid we didn't really have a way to detect
> whether a target supported SSE or not.

Well, then it should be part of the target configuration.

> Does Go32 really have no support for the SSE registers?

Yes, really.  The debug interface provided by DPMI (the interface for
running protected-mode programs on DOS, which is a real-mode OS) does
not support SSE.  And since no one is developing the DPMI spec or DPMI
ser5vices these days, SSE will never be supported by DJGPP.  In fact,
none of the special registers of the modern x86 CPUs (XMM etc.) will
ever be supported.

Therefore, the fact that SSE is not supported by DJGPP can be
established at compile time.