Re: [PATCH] vect: Use statement vectype for conditional mask.

[Richard Biener <richard.guenther@gmail.com>]

On Fri, Nov 17, 2023 at 9:45 AM Robin Dapp <rdapp.gcc@gmail.com> wrote:
>
> > But note you can explicitly specify a vector type as well, there's an
> > overload for it, so we can fix the "invariant" case with the following
> > (OK if you can test this on relevant targets)
> >
> > diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc
> > index 3f59139cb01..936a3de9534 100644
> > --- a/gcc/tree-vect-loop.cc
> > +++ b/gcc/tree-vect-loop.cc
> > @@ -8450,12 +8450,14 @@ vect_transform_reduction (loop_vec_info loop_vinfo,
> >       value. */
> >    bool cond_fn_p = code.is_internal_fn ()
> >      && conditional_internal_fn_code (internal_fn (code)) != ERROR_MARK;
> > +  int cond_index = -1;
> >    if (cond_fn_p)
> >      {
> >        gcc_assert (code == IFN_COND_ADD || code == IFN_COND_SUB
> >                   || code == IFN_COND_MUL || code == IFN_COND_AND
> >                   || code == IFN_COND_IOR || code == IFN_COND_XOR);
> >        gcc_assert (op.num_ops == 4 && (op.ops[1] == op.ops[3]));
> > +      cond_index = 0;
> >      }
> >
> >    bool masked_loop_p = LOOP_VINFO_FULLY_MASKED_P (loop_vinfo);
> > @@ -8486,12 +8488,13 @@ vect_transform_reduction (loop_vec_info loop_vinfo,
> >    vect_get_vec_defs (loop_vinfo, stmt_info, slp_node, ncopies,
> >                      single_defuse_cycle && reduc_index == 0
> >                      ? NULL_TREE : op.ops[0], &vec_oprnds0,
> > +                    cond_index == 0 ? truth_type_for (vectype_in) : NULL_TREE,
> >                      single_defuse_cycle && reduc_index == 1
> > -                    ? NULL_TREE : op.ops[1], &vec_oprnds1,
> > +                    ? NULL_TREE : op.ops[1], &vec_oprnds1, NULL_TREE,
> >                      op.num_ops == 4
> >                      || (op.num_ops == 3
> >                          && !(single_defuse_cycle && reduc_index == 2))
> > -                    ? op.ops[2] : NULL_TREE, &vec_oprnds2);
> > +                    ? op.ops[2] : NULL_TREE, &vec_oprnds2, NULL_TREE);
>
> Ah, yes that's what I meant.  I had something along those lines:
>
> +  if (!cond_fn_p)
> +    {
> +      vect_get_vec_defs (loop_vinfo, stmt_info, slp_node, ncopies,
> +                        single_defuse_cycle && reduc_index == 0
> +                        ? NULL_TREE : op.ops[0], &vec_oprnds0,
> +                        single_defuse_cycle && reduc_index == 1
> +                        ? NULL_TREE : op.ops[1], &vec_oprnds1,
> +                        op.num_ops == 3
> +                        && !(single_defuse_cycle && reduc_index == 2)
> +                        ? op.ops[2] : NULL_TREE, &vec_oprnds2);
> +    }
> +  else
> +    {
> +      /* For a conditional operation, pass the truth type as vectype for the
> +        mask.  */
> +      gcc_assert (single_defuse_cycle && reduc_index == 1);
> +      vect_get_vec_defs (loop_vinfo, stmt_info, slp_node, ncopies,
> +                        op.ops[0], &vec_oprnds0,
> +                        truth_type_for (vectype_in),
> +                        NULL_TREE, &vec_oprnds1, NULL_TREE,
> +                        op.ops[2], &vec_oprnds2, NULL_TREE);
> +    }
>
> Even though this has a bit of duplication now I prefer it slightly
> because of the.  I'd hope, once fully tested (it's already running
> but I'm having connection problems so don't know about the results
> yet), this could go in independently of the pattern fix?

Yes, your version is also OK.

Thanks,
Richard.

>
> Regards
>  Robin
>