RFR: 8291600: [vectorapi] vector cast op check is not always needed for vector mask cast [v4]

[Xiaohong Gong]

On Mon, 29 Aug 2022 06:43:38 GMT, Jie Fu <jiefu at openjdk.org> wrote:

> Thanks for the update.
> 
> May I ask can we do it like this?
> 
> ```
> diff --git a/src/hotspot/share/opto/vectorIntrinsics.cpp b/src/hotspot/share/opto/vectorIntrinsics.cpp
> index 66bacf0..c4e807a 100644
> --- a/src/hotspot/share/opto/vectorIntrinsics.cpp
> +++ b/src/hotspot/share/opto/vectorIntrinsics.cpp
> @@ -2494,8 +2494,9 @@ bool LibraryCallKit::inline_vector_convert() {
>        new_elem_bt_from = elem_bt_from == T_FLOAT ? T_INT : T_LONG;
>      }
>      int cast_vopc = VectorCastNode::opcode(new_elem_bt_from, !is_ucast);
> +    bool no_vec_cast_check = is_mask && (type2aelembytes(elem_bt_from) == type2aelembytes(elem_bt_to));
>      // Make sure that cast is implemented to particular type/size combination.
> -    if (!arch_supports_vector(cast_vopc, num_elem_to, elem_bt_to, VecMaskNotUsed)) {
> +    if (!no_vec_cast_check && !arch_supports_vector(cast_vopc, num_elem_to, elem_bt_to, VecMaskNotUsed)) {
>        if (C->print_intrinsics()) {
>          tty->print_cr("  ** not supported: arity=1 op=cast#%d/3 vlen2=%d etype2=%s ismask=%d",
>                        cast_vopc,
> ```

Thanks for the advice! The new commit has fixed this issue. Could you please check whether it is ok for you? Thanks!

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PR: https://git.openjdk.org/jdk/pull/9737