pa.md bugfix

[Jeffrey A Law]

  In message < 200101231750.MAA26766@hiauly1.hia.nrc.ca >you write:
  > >   > > + ;; We use the PIC register to ensure it's restored after a
  > >   > > + ;; call in PIC mode.  This can be non-optimal for non-PIC
  > >   > > + ;; code but the real world cost should be unmeasurable.
  > >   > >   (define_insn "return_internal"
  > >   > 
  > >   > Suggest two insns: pic_return_internal and return_internal.  We only
  > >   > need the extra use in pic_return_internal.
  > > Already considered it.  It's not worth the time/effort.
  > > 
  > > FWIW, there *is* a minor bug in the patch.  It breaks PA64 because of the
  > > mode on the use of the PIC register.  I'll fix that in a minute.
  > 
  > Are you still interested in this patch:
  > < http://gcc.gnu.org/ml/gcc-patches/2001-01/msg01482.html >?  The
  > EPILOGUE_USES part is no longer necessary although I have found that
  > it doesn't hurt to to define the uses in both places.
Yes, but without the EPILOGUE_USES part.

We'd really like to avoid EPILOGUE_USES as a design goal -- it's basically
encoding use information outside of RTL, which is in general going to be the
wrong thing to do.

jeff