Re: register_offset_hack() vs REGISTER_BYTE()

[Andrew Cagney <ac131313 at redhat dot com>]

> > Er, for a legacy architecture, register_offset_hack(i) (aka 
> > current_regcache->descr->register_offset) should be REGISTER_BYTE(i). 
> > See init_legacy_regcache_descr.
> >
> > Sounds like the MIPS is sneeking past:
> >
> >    /* If an old style architecture, fill in the remainder of the
> >       register cache descriptor using the register macros.  */
> >    if (!gdbarch_pseudo_register_read_p (gdbarch)
> >        && !gdbarch_pseudo_register_write_p (gdbarch)
> >        && !gdbarch_register_type_p (gdbarch))
> >      {
> >        descr->legacy_p = 1;
> >        init_legacy_regcache_descr (gdbarch, descr);
> >        return descr;
> >      }
>
>
> Hmm, yes.  I just added some pseudo registers...

Can probably change REGISTER_BYTE to a pre-initialized method with 
predicate (see DEPRECATED_PC_IN_CALL_DUMMY for an example), and then add 
a predicate test for it to the above mix.

Sentinel frame should probably also be switched to using 
register_offset_hack(), instead of REGISTER_BYTE(), so that it is more 
consistent with the frame code.

Sounds like it's time to s/ REGISTER_BYTE / DEPRECATED_REGISTER_BYTE /. 
 It isn't yet possible to eliminate that macro from the MIPS since it 
is that hardwired mystery that defines the MIPS remote protocol :-(

Andrew