On Mon, 17 Nov 2025, Tamar Christina wrote:
> This change allows a target to only implement the explicit vec_cbranch optabs.
> To do this the vectorizer is updated to check for the new optabs directly.
>
> Targets that have a different type for BOOLEAN_VECTOR_TYPE_P for instance
> can use only the new optabs.
>
> Bootstrapped Regtested on aarch64-none-linux-gnu,
> arm-none-linux-gnueabihf, x86_64-pc-linux-gnu
> -m32, -m64 and no issues.
>
> Ok for master?
This LGTM.
Richard.
> Thanks,
> Tamar
>
> gcc/ChangeLog:
>
> PR target/118974
> * tree-vect-stmts.cc (supports_vector_compare_and_branch): New.
> (vectorizable_early_exit): Use it.
>
> ---
> diff --git a/gcc/tree-vect-stmts.cc b/gcc/tree-vect-stmts.cc
> index
> 25ec87022f2ad5726dcc71aa1630b655e2ecfe0b..eb8f636eeb2976c1b44cc6cb06c2cda8b97662c0
> 100644
> --- a/gcc/tree-vect-stmts.cc
> +++ b/gcc/tree-vect-stmts.cc
> @@ -12644,6 +12644,39 @@ vectorizable_comparison (vec_info *vinfo,
> return true;
> }
>
> +/* Check to see if the target supports any of the compare and branch optabs
> for
> + vectors with MODE as these would be required when expanding. */
> +static bool
> +supports_vector_compare_and_branch (loop_vec_info loop_vinfo, machine_mode
> mode)
> +{
> + bool masked_loop_p = LOOP_VINFO_FULLY_MASKED_P (loop_vinfo);
> + bool len_loop_p = LOOP_VINFO_FULLY_WITH_LENGTH_P (loop_vinfo);
> +
> + /* The vectorizer only produces vec_cbranch_any_optab directly. So only
> + check for support for that or vec_cbranch_any_optab when masked.
> + We can't produce vcond_cbranch_any directly from the vectorizer as we
> + want to keep gimple_cond as the GIMPLE representation. But we'll fold
> + it in expand. For that reason we require a backend to support the
> + unconditional vector cbranch optab if they support the conditional one,
> + which is just an optimization on the unconditional one. */
> + if (masked_loop_p
> + && direct_optab_handler (cond_vec_cbranch_any_optab, mode)
> + != CODE_FOR_nothing)
> + return true;
> + else if (len_loop_p
> + && direct_optab_handler (cond_len_vec_cbranch_any_optab, mode)
> + != CODE_FOR_nothing)
> + return true;
> + else if (!masked_loop_p && !len_loop_p
> + && direct_optab_handler (vec_cbranch_any_optab, mode)
> + != CODE_FOR_nothing)
> + return true;
> +
> + /* The target can implement cbranch to distinguish between boolean vector
> + types and data types if they don't have a different mode for both. */
> + return direct_optab_handler (cbranch_optab, mode) != CODE_FOR_nothing;
> +}
> +
> /* Check to see if the current early break given in STMT_INFO is valid for
> vectorization. */
>
> @@ -12718,8 +12751,8 @@ vectorizable_early_exit (loop_vec_info loop_vinfo,
> stmt_vec_info stmt_info,
> tree tmp_type = build_vector_type (itype, TYPE_VECTOR_SUBPARTS
> (vectype));
> narrow_type = truth_type_for (tmp_type);
>
> - if (direct_optab_handler (cbranch_optab, TYPE_MODE (narrow_type))
> - == CODE_FOR_nothing)
> + if (!supports_vector_compare_and_branch (loop_vinfo,
> + TYPE_MODE (narrow_type)))
> {
> if (dump_enabled_p ())
> dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
> @@ -12734,7 +12767,7 @@ vectorizable_early_exit (loop_vec_info loop_vinfo,
> stmt_vec_info stmt_info,
> if (cost_vec)
> {
> if (!addhn_supported_p
> - && direct_optab_handler (cbranch_optab, mode) == CODE_FOR_nothing)
> + && !supports_vector_compare_and_branch (loop_vinfo, mode))
> {
> if (dump_enabled_p ())
> dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
>
>
>
--
Richard Biener <[email protected]>
SUSE Software Solutions Germany GmbH,
Frankenstrasse 146, 90461 Nuernberg, Germany;
GF: Jochen Jaser, Andrew McDonald, Werner Knoblich; (HRB 36809, AG Nuernberg)
