Re: [PATCH 4/4] target/mips: Do not treat msa INSERT as NOP when wd is zero

[Philippe Mathieu-Daudé]

On 3/5/22 15:07, nihui wrote:
> From: Ni Hui <shuizhuyuanluo@126.com>
>
> Only for msa COPY_U/COPY_S with wd zero, we treat it as NOP.
>
> Move this special rule into COPY_U and COPY_S trans function.

Fixes: 97fe675519 ("target/mips: Convert MSA COPY_S and INSERT opcodes 
to decodetree")

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

> Signed-off-by: Ni Hui <shuizhuyuanluo@126.com>
> ---
>   target/mips/tcg/msa_translate.c | 15 ++++++++++-----
>   1 file changed, 10 insertions(+), 5 deletions(-)
>
> diff --git a/target/mips/tcg/msa_translate.c b/target/mips/tcg/msa_translate.c
> index 92ccc6f921..0b3dd0957c 100644
> --- a/target/mips/tcg/msa_translate.c
> +++ b/target/mips/tcg/msa_translate.c
> @@ -603,11 +603,6 @@ static bool trans_msa_elm_fn(DisasContext *ctx, 
> arg_msa_elm_df *a,
>           return true;
>       }
>   
> -    if (a->wd == 0) {
> -        /* Treat as NOP. */
> -        return true;
> -    }
> -
>       gen_msa_elm[a->df](cpu_env,
>                          tcg_constant_i32(a->wd),
>                          tcg_constant_i32(a->ws),
> @@ -624,6 +619,11 @@ static bool trans_msa_elm_fn(DisasContext *ctx, 
> arg_msa_elm_df *a,
>   
>   static bool trans_COPY_U(DisasContext *ctx, arg_msa_elm_df *a)
>   {
> +    if (a->wd == 0) {
> +        /* Treat as NOP. */
> +        return true;
> +    }
> +
>       static gen_helper_piii * const gen_msa_copy_u[4] = {
>           gen_helper_msa_copy_u_b, gen_helper_msa_copy_u_h,
>           NULL_IF_MIPS32(gen_helper_msa_copy_u_w), NULL
> @@ -634,6 +634,11 @@ static bool trans_COPY_U(DisasContext *ctx, arg_msa_elm_df 
> *a)
>   
>   static bool trans_COPY_S(DisasContext *ctx, arg_msa_elm_df *a)
>   {
> +    if (a->wd == 0) {
> +        /* Treat as NOP. */
> +        return true;
> +    }
> +
>       static gen_helper_piii * const gen_msa_copy_s[4] = {
>           gen_helper_msa_copy_s_b, gen_helper_msa_copy_s_h,
>           gen_helper_msa_copy_s_w, NULL_IF_MIPS32(gen_helper_msa_copy_s_d)