On Sat, Oct 12, 2024 at 9:12 AM Feng Xue OS <[email protected]> wrote:
>
> To align vectorized def/use when lane-reducing op is present in loop
> reduction,
> we may need to insert extra trivial pass-through copies, which would cause
> mismatch between lane-reducing vector copy and loop mask index. This could be
> fixed by computing the right index around a new counter on effective lane-
> reducing vector copies.
OK, but can you add the reduced testcase from the PR in a way that it ICEs
before and not after the patch?
Thanks,
Richard.
> Thanks,
> Feng
> ---
> gcc/
> PR tree-optimization/116985
> * tree-vect-loop.cc (vect_transform_reduction): Compute loop mask
> index based on effective vector copies for reduction op.
> ---
> gcc/tree-vect-loop.cc | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc
> index ade72a5124f..025442aabc3 100644
> --- a/gcc/tree-vect-loop.cc
> +++ b/gcc/tree-vect-loop.cc
> @@ -8916,6 +8916,7 @@ vect_transform_reduction (loop_vec_info loop_vinfo,
>
> bool emulated_mixed_dot_prod = vect_is_emulated_mixed_dot_prod (stmt_info);
> unsigned num = vec_oprnds[reduc_index == 0 ? 1 : 0].length ();
> + unsigned mask_index = 0;
>
> for (unsigned i = 0; i < num; ++i)
> {
> @@ -8954,7 +8955,8 @@ vect_transform_reduction (loop_vec_info loop_vinfo,
> std::swap (vop[0], vop[1]);
> }
> tree mask = vect_get_loop_mask (loop_vinfo, gsi, masks,
> - vec_num * ncopies, vectype_in, i);
> + vec_num * ncopies, vectype_in,
> + mask_index++);
> gcall *call = gimple_build_call_internal (cond_fn, 4, mask,
> vop[0], vop[1], vop[0]);
> new_temp = make_ssa_name (vec_dest, call);
> @@ -8971,7 +8973,8 @@ vect_transform_reduction (loop_vec_info loop_vinfo,
> if (masked_loop_p && mask_by_cond_expr)
> {
> tree mask = vect_get_loop_mask (loop_vinfo, gsi, masks,
> - vec_num * ncopies, vectype_in,
> i);
> + vec_num * ncopies, vectype_in,
> + mask_index++);
> build_vect_cond_expr (code, vop, mask, gsi);
> }
>
> --
> 2.17.1
>
>
>
