Re: PATCH: Extend gdb remote protocol for AVX

Daniel Jacobowitz
2008-09-18T19:39:42Z

On Thu, Sep 18, 2008 at 12:03:11PM -0700, H.J. Lu wrote:
> On Thu, Sep 18, 2008 at 11:34 AM, Daniel Jacobowitz
> <dan@codesourcery.com> wrote:
> > On Thu, Sep 18, 2008 at 10:27:28AM -0700, H.J. Lu wrote:
> >> b. If remote target supports AVX:
> >> i. Don't send xmlarch.
> >> ii. Replace 128bit xmm registers with 256bit ymm registers in
> >> the g/G packet.
> >> iii. Gdb will auto-detect SSE unit on remote target, based on the
> >> the g/G packet size.
> >
> > Just a general note: I would much prefer you use the XML mechanism for
> > this, either by an architecture name or a property or an explicit
> > register description, than add more guesses to the g/G packet checks;
> > they're a heuristic for existing remote targets.
> >
>
> I tried adding xmlarch to regformats files. But I don't want to add new
> xmlarch entry for AVX since I had to create a new arch entry in BFD for it. It
> isn't necessary for this purpose. If I use the existing xmlarch, like
> i386:x86-64, it will match regformats/reg-x86-64.dat. Using
> the g/G packet size allows me not to add a new arch entry in BFD.
> Is there a way to do it with XML without changing BFD?

Yes, either of the other two options I described. MIPS uses both of
them; search for PROPERTY_GP32 or tdesc_has_registers.

--
Daniel Jacobowitz
CodeSourcery