On Thu, Oct 22, 2020 at 08:41:50AM +1030, Alan Modra wrote:
> On Wed, Oct 21, 2020 at 03:29:11PM -0500, Segher Boessenkool wrote:
> > Anyway:
> >
> > + || (outer_code == AND
> > + && rs6000_is_valid_2insn_and (x, mode)))
> > {
> > *total = COSTS_N_INSNS (1);
> > return true;
> >
> > It should return COSTS_N_INSNS (2) for that?
>
> No, it should not!
>
> /* (reg) is costed at zero by rtlanal.c:rtx_cost. That sets a
> baseline for rtx costs: If a constant is valid in an insn,
> it is free. */
Yeah, this keeps tripping me up.
The patch is okay for trunk (as I told you offline). Thanks!
The regressions are really from existing bad behaviour in expand :-(
Segher
