On Thu, 10 Jul 2025, Jan Hubicka wrote:
> > The x86 add_stmt_hook relies on the passed vectype to determine
> > the mode and whether it is FP for a scalar operation. This is
> > unreliable now for stmts involving patterns and in the future when
> > there is no vector type passed for scalar operations.
> >
> > To be least disruptive I've kept using the vector type if it is passed.
> >
> > Bootstrapped and tested on x86_64-unknown-linux-gnu.
> >
> > OK?
> >
> > Thanks
> > Richard.
> >
> > * config/i386/i386.cc (ix86_vector_costs::add_stmt_cost): Use
> > the LHS of a scalar stmt to determine mode and whether it is FP.
> > ---
> > gcc/config/i386/i386.cc | 6 ++++++
> > 1 file changed, 6 insertions(+)
> >
> > diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
> > index ad7360ec71a..26eefadea64 100644
> > --- a/gcc/config/i386/i386.cc
> > +++ b/gcc/config/i386/i386.cc
> > @@ -25798,6 +25798,12 @@ ix86_vector_costs::add_stmt_cost (int count,
> > vect_cost_for_stmt kind,
> > if (scalar_p)
> > mode = TYPE_MODE (TREE_TYPE (vectype));
> > }
> > + else if (scalar_p && stmt_info)
> > + if (tree lhs = gimple_get_lhs (stmt_info->stmt))
> > + {
> > + fp = FLOAT_TYPE_P (TREE_TYPE (lhs));
> > + mode = TYPE_MODE (TREE_TYPE (lhs));
> > + }
> Makes sense to me, but perhaps it would be good idea to add a comment,
> since it looks odd at first glance?
Like
/* When we are costing a scalar stmt use the scalar stmt to get at the
type of the operation. */
?
Richard.
> Honza
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH,
Frankenstrasse 146, 90461 Nuernberg, Germany;
GF: Ivo Totev, Andrew McDonald, Werner Knoblich; (HRB 36809, AG Nuernberg)
