Re: RFA: modernization of ia64-tdep.c with new frame model for gdb-6.0branch

["J. Johnston" <jjohnstn at redhat dot com>]

Kevin Buettner wrote:
> On Aug 25,  2:12pm, J. Johnston wrote:
>
>
> > Kevin Buettner wrote:
>
>
> > > Okay, I see that you're turning r32-r127 and (not shown) p0-p64
> > > into pseudo registers.  Is there any reason to leave big "holes"
> > > in the register number space?  I.e, why not just get rid of all
> > > of the empty strings above?
> > >
> > > (Most of the time, the reason NOT to do this is because remote
> > > targets depend on the order.  The only remote target that I'm
> > > aware of is gdbserver, and I'm not particularly worried about
> > > breaking compatibility.)
> > >
> > > If I'm not mistaken, removing these holes will somewhat decrease
> > > the size of struct ia64_frame_cache:
> > >
> > >    +struct ia64_frame_cache
> > >    +{
> > >    ...
> > >    +  /* Saved registers.  */
> > >    +  CORE_ADDR saved_regs[NUM_IA64_RAW_REGS];
> > >    +
> > >    +};
> >
> > Actually, number of real raw registers went down to the last non-pseudo
> > register anyway.  My preference regarding renumbering registers would be
> > to sync this up with gdbserver later.
>
>
> Okay, so long as "later" isn't too much later.  It'd be a shame if someone
> suddenly wrote a stub which depended on the holes being there...
>
>
> > > Have you tested the nat bit related code in ia64_pseudo_register_read()
> > > and ia64_pseudo_register_write() ?  My recollection is that my original
> > > code didn't handle the unat bits correctly.  I was wondering if you
> > > had fixed this problem.  (I'm curious about the other NaT bits too.)
> >
> > Could you elaborate about what problems you think existed in the previous
> > code?
>
>
> I'll send you a thread which describes the problems.  After rereading
> that thread, it looks like the fix isn't as difficult as I had
> remembered.  In fact, it should be pretty easy.  (But it still needs
> to be tested.)
>
> With regard to your current patch, I'm okay with you checking it in
> after adding the ia64_frame_cache comments.
>
> Thanks for doing these cleanups.
>
> Kevin

Thanks Kevin.  Patch is checked in with comments added.

-- Jeff J.