On Fri, 2018-08-17 at 16:00 +0200, Richard Biener wrote:
> On Wed, Aug 8, 2018 at 12:59 AM Segher Boessenkool
> <seg...@kernel.crashing.org> wrote:
> >
> > Hi!
> >
> > On Tue, Aug 07, 2018 at 02:24:58PM -0500, Will Schmidt wrote:
> > > This adds support for gimple folding of vec_mergeh and vec_mergel
> > > for float and double types. Support for the integral types is already
> > > in-tree.
> >
> > > + /* The permute_type will match the lhs for integral types. For double
> > > and
> > > + float types, the permute type needs to map to the V2 or V4 type that
> > > + matches size. */
> > > + tree permute_type;
> > > + if (INTEGRAL_TYPE_P (TREE_TYPE (lhs_type)))
> > > + permute_type = lhs_type;
> > > + else
> > > + if (TREE_TYPE (lhs_type) == TREE_TYPE (V2DF_type_node))
> > > + permute_type = V2DI_type_node;
> > > + else if (TREE_TYPE (lhs_type) == TREE_TYPE (V4SF_type_node))
> > > + permute_type = V4SI_type_node;
> > > + else
> > > + gcc_unreachable ();
> >
> > Please write this as
> >
> > if (INTEGRAL_TYPE_P (TREE_TYPE (lhs_type)))
> > permute_type = lhs_type;
> > else if (TREE_TYPE (lhs_type) == TREE_TYPE (V2DF_type_node))
> > permute_type = V2DI_type_node;
> > else if (TREE_TYPE (lhs_type) == TREE_TYPE (V4SF_type_node))
> > permute_type = V4SI_type_node;
> > else
> > gcc_unreachable ();
> >
> > or, if you want to emphasize integer vs. float:
> >
> > if (INTEGRAL_TYPE_P (TREE_TYPE (lhs_type)))
> > permute_type = lhs_type;
> > else
> > {
> > if (TREE_TYPE (lhs_type) == TREE_TYPE (V2DF_type_node))
>
> Are you sure lhs_type is never qualified?
For the V2DF and V4SF types, I am mostly sure, but since you bring it up
I will admit I am not positive. :-)
> That is, for a GIMPLE folder
> I'd have expected
>
> if (types_compatible_p (TREE_TYPE (lhs_type), TREE_TYPE (V2DF_type_node)))
> for GENERIC
>
> if (TYPE_MAIN_VARIANT (TREE_TYPE (lhs_type)) == TREE_TYPE (V2DF_type_node))
Either/both of those seem more robust than what I had come up with, I'll
plan to make an update here.
Any guidance on whether I should prefer "types_compatible_p" versus the
GENERIC "TYPE_MAIN_VARIANT" ? I see more references to the latter in
rs6000.c , but the former seems to make better sense to me just by its
name.
Thanks for the review,
-Will
> Richard.
>
> > permute_type = V2DI_type_node;
> > else if (TREE_TYPE (lhs_type) == TREE_TYPE (V4SF_type_node))
> > permute_type = V4SI_type_node;
> > else
> > gcc_unreachable ();
> > }
> >
> > Okay for trunk with that changed. Thanks!
> >
> >
> > Segher
>
