On Sat, Aug 10, 2024 at 09:18:24AM +0200, Jakub Jelinek wrote:
> On Fri, Aug 09, 2024 at 07:12:48PM +0200, Jakub Jelinek wrote:
> > > --- a/gcc/gimple.def
> > > +++ b/gcc/gimple.def
> > > @@ -398,6 +398,13 @@ DEFGSCODE(GIMPLE_OMP_TEAMS, "gimple_omp_teams",
> > > GSS_OMP_PARALLEL_LAYOUT)
> > > CLAUSES is an OMP_CLAUSE chain holding the associated clauses. */
> > > DEFGSCODE(GIMPLE_OMP_ORDERED, "gimple_omp_ordered",
> > > GSS_OMP_SINGLE_LAYOUT)
> > >
> > > +/* GIMPLE_OMP_METADIRECTIVE represents #pragma omp metadirective. */
> > > +DEFGSCODE(GIMPLE_OMP_METADIRECTIVE, "gimple_omp_metadirective",
> > > + GSS_OMP_METADIRECTIVE)
> > > +
> > > +DEFGSCODE(GIMPLE_OMP_METADIRECTIVE_VARIANT,
> > > + "gimple_omp_variant", GSS_OMP_METADIRECTIVE_VARIANT)
> > > +
>
> Oh, and I wonder if there shouldn't be a different representation of this in
> GIMPLE.
> GIMPLE_OMP_METADIRECTIVE in the patch seems to have both the TREE_LISTs for
> the variants and the labels.
> We already have a construct which can have a set of labels, GIMPLE_SWITCH,
> and tons of optimizations available for it.
> Can't GIMPLE_OMP_METADIRECTIVE be just the list of TREE_LISTs for the
> variants which sets some integer SSA_NAME with a GIMPLE_SWITCH next to it
> which picks what code will be used? And, to simplify the SSA scanners,
> perhaps have the device_num and condition operands hoisted to separate ops.
> So, ops[0] would be the output, artificial integer result used in
> GIMPLE_SWITCH, ops[1] say condition SSA_NAME (if dynamic condition isn't
> used, then boolean_true_node), ops[2] say device_num SSA_NAME (if unused
> some negative INTEGER_CST which can't otherwise happen)?
> Perhaps we'd want to avoid GIMPLE_SWITCH lowering if the controlling
> SSA_NAME has GIMPLE_OMP_METADIRECTIVE def_stmt (because we expect it to
> fold into a constant), but otherwise other GIMPLE_SWITCH optimizations might
> be ok.
>
> What do you think? Or am I missing something?
Please ignore the part about dynamic condition/device_num, each variant
obviously will have its own. But the rest stands.
Jakub
