Re: How do I examine the FPU/MMX registers?

[Mark Kettenis <kettenis at wins dot uva dot nl>]

   Date: Mon, 25 Oct 1999 06:53:18 -0700 (PDT)
   From: Ryan Gustafson <ryan_gustafson@yahoo.com>

   While debugging my MMX code in gdb, I've tried using 'info registers'
   and 'info all-registers'.  No luck.  I've tried using 'info float',
   but I get this:

      (gdb) info float
      No floating point info available for this processor.

There is no FPU support in gdb 4.18 on Linux.

   Any thoughts here?  Is there a version of gdb I can download which
   will "work" for me?  I noticed the recent conversations on this
   (H. J. Lu, et al), is there a specially patched gdb for Linux/x86
   I should get?

We're working on it :-).  The current CVS snapshot (see
http://sourceware.cygnus.com) contains some code that displays the FPU
registers for `info all-registers'.  However this is very much work in
progress and not very stable.  HJ releases his own special Linux GDB
which is based on GDB 4.17 that has FPU support.  Although I'm
hesitating to recomend its usage, it probably works for you.  I don't
know where you can find it though.  Look for version numbers like
4.17.0.x.  Keep in mind that there will be some details (such as the
names of the FP registers and the layout of the `info float' command)
that will be different in the next official GDB release.

Mark