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

["J. Johnston" <jjohnstn@redhat.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.