[Bug target/59401] [SH] GBR addressing mode optimization produces wrong code

[olegendo at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59401

--- Comment #11 from Oleg Endo <olegendo at gcc dot gnu.org> ---
Created attachment 33723
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=33723&action=edit
Make GBR call preserved by default

(In reply to Oleg Endo from comment #10)
> (In reply to Kazumoto Kojima from comment #9)
> > (In reply to Oleg Endo from comment #8)
> > > change the
> > > value for gbr in sh.h CALL_USED_REGISTERS from '1' to '0' and confirm that
> > > everything is still OK?
> > 
> > The comment and document about CALL_USED_REGISTERS say that it must be
> > a superset of FIXED_REGISTERS.  CALL_REALLY_USED_REGISTERS might be
> > a macro for that purpose.
> 
> Right.  In this case it's probably better to do it in
> sh_conditional_register_usage.  It would be nice if '-fcall-saved-gbr' and
> '-fcall-used-gbr' still remained functional afterwards ... I'll give it a
> try.

sh_conditional_register_usage is invoked after the -fcall-*-* options are
processed.  Defining the CALL_REALLY_USED_REGISTERS macro with the default
values works as expected, i.e. -fcall-used-gbr still works.

Kaz, could you please add the attached patch to your test run?