On Wed, Oct 21, 2020 at 04:43:29PM +0100, Richard Sandiford wrote:
> Hongtao Liu <crazy...@gmail.com> writes:
> > + poly_uint64 nunits
> > + = GET_MODE_NUNITS (GET_MODE (SUBREG_REG (trueop0)));
> > + rtx par = trueop1;
> > + for (int i = 0; i != l1; i++)
> > + {
> > + rtx idx = XVECEXP (trueop1, 0, i);
> > + if (!CONST_INT_P (idx)
> > + || maybe_ge (UINTVAL (idx) + subreg_offset, nunits))
> > + return 0;
> > + }
>
> I think the previous version was better. We shouldn't assume that
> further simplification rules will fail just because the conditions
> for this rule haven't been met.
Yes. My suggestion was to factor this big piece of code to a separate
function, and do an early return from *that*.
The patch is okay for trunk without that, with the clumsy booleans.
Thanks Hongtao!
Segher
