Re: current CVS gdb and SSE xmm registers don't work

[Mark Kettenis <kettenis@science.uva.nl>]

Andrew Cagney <ac131313@cygnus.com> writes:

> > Hi,
> > 
> > with current gdb+dejagnu (1day old) and also gdb from 20010622, displaying of 
> > the Pentium IIIs SSE registers in gdb doesn't work correct anymore, when I do 
> > for example print $xmm0 all 4 values displayed are -NaN (always, even 
> > directly after loading data into that register).
> > I'm using Linux 2.4.4 kernel with suse patches, compiled for PIII, gcc 2.95.3 
> > and glibc 2.2. Software I debugged was compiled with -g3 compilerflag.
> > 

> > This is what it looks like:
> > (gdb) print $xmm0
> > $12 = {f = {-nan(0x7fffff), -nan(0x7fffff), -nan(0x7fffff), -nan(0x7fffff)}}
> > 
> > I know that it worked with older snapshot from around april/may 2001, but 
> > I've deleted that one :(
> > -- Best Regards, Felix
> 
> 
> What happens if you use gdb/i387-tdep.c version 1.9 instead of 1.12? 
> Sounds like my ``tweek'' may still be breaking it :-/

I don't think your tweek has anything to do with it Andrew.  From the
information Felix provides, I conclude that somehow a
PTRACE_GETFPXREGS request is failing (see
i386-linux-nat.c:fetch_fpxregs()).  Therefore I would suspect this to
be a kernel bug, or misconfiguration.  Felix, can debug GDB itself
(using GDB :-)) and see why that particular ptrace call is failing?  I
cannot do this myself, since I don't have a PIII.

Mark