On Fri, Nov 4, 2022 at 8:14 PM Jakub Jelinek <jakub@redhat.com> wrote:
>
> On Mon, Oct 17, 2022 at 08:21:01AM +0200, Aldy Hernandez wrote:
> > +// Set VALUE to its next real value, or INF if the operation overflows.
> > +
> > +inline void
> > +frange_nextafter (enum machine_mode mode,
> > +               REAL_VALUE_TYPE &value,
> > +               const REAL_VALUE_TYPE &inf)
> > +{
> > +  const real_format *fmt = REAL_MODE_FORMAT (mode);
> > +  REAL_VALUE_TYPE tmp;
> > +  bool overflow = real_nextafter (&tmp, fmt, &value, &inf);
> > +  if (overflow)
> > +    value = inf;
> > +  else
> > +    value = tmp;
>
> Please change the above 5 lines to just
>   real_nextafter (&tmp, fmt, &value, &inf);
>   value = tmp;

Done.

As suggested upthread, I have also adjusted update_nan_sign() to drop
the NAN sign to VARYING if both operands are NAN.  As an optimization
I keep the sign if both operands are NAN and have the same sign.

How's this?

Tested on x86-64 Linux.  LAPACK testing as well.

Aldy