On Fri, Jul 08, 2016 at 12:43:35AM -0500, Segher Boessenkool wrote:
> On Thu, Jul 07, 2016 at 03:42:55PM -0500, Pat Haugen wrote:
> > The following patch corrects the constraint so that we only generate
> > 'stxsiwx' on Power8 or later hardware. Ok for trunk after successful
> > bootstrap/regtest?
>
> I don't really understand this. Before, it required UPPER_REGS_DF (which
> seems correct), and now it requires UPPER_REGS_SF, which seems wrong.
After some discussion... Okay, so it is a bit sub-optimal, but it does
work. Okay for trunk, with a comment on why it is "wu" ("because "wu"
requires power8").
Thanks,
Segher
> > --- config/rs6000/rs6000.md (revision 238117)
> > +++ config/rs6000/rs6000.md (working copy)
> > @@ -5748,7 +5748,7 @@ (define_expand "lround<mode>di2"
> > ; An UNSPEC is used so we don't have to support SImode in FP registers.
> > (define_insn "stfiwx"
> > [(set (match_operand:SI 0 "memory_operand" "=Z,Z")
> > - (unspec:SI [(match_operand:DI 1 "gpc_reg_operand" "d,wv")]
> > + (unspec:SI [(match_operand:DI 1 "gpc_reg_operand" "d,wu")]
> > UNSPEC_STFIWX))]
> > "TARGET_PPC_GFXOPT"
> > "@
