Fix rs6000 compatibility predicate

[Nick Clifton]

Hi Jim,

> So, is this patch rejected or accepted?  If it is rejected, what
> changes should I make before resubmitting it?

Sorry - I was hoping that an RS6000 maintainer would take a look at
this one.

>> The code for bfd/cpu-rs6000.c:rs6000_compatible looks wrong to me.
>> The logic there says that A, which we assert to be a bfd_arch_rs6000,
>> is only compatible with a B whose arch is bfd_arch_powerpc and whose
>> mach is bfd_mach_rs6k.  But that's an rs6000 mach, not a powerpc mach;
>> there should never be a bfd_arch_powerpc / bfd_mach_rs6k arch info.
>> Is that right?

Right.

>> The code as changed by the patch below would make more sense to me:
>> all powerpc machines are supersets of the base rs6000 machine, but
>> there the two lines diverged, so any later model of the rs6000 is
>> incompatible with any later powerpc model.
>> 
>> 2003-10-21  Jim Blandy  <jimb@redhat.com>
>> 
>> 	* cpu-rs6000.c (rs6000_compatible): Check the correct arch_info
>> 	object's mach field: all PowerPC machines are supersets of the
>> 	original rs6000, but not later rs6000 machines.

Approved and applied.

Cheers
        Nick