Re: [Qemu-devel] [PATCH 4/9] target/arm: Clear SVE high bits for FMOV

["Alex Bennée" <alex.bennee@linaro.org>]

Richard Henderson <richard.henderson@linaro.org> writes:

> Use write_fp_dreg and clear_vec_high to zero the bits
> that need zeroing for these cases.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  target/arm/translate-a64.c | 17 +++++------------
>  1 file changed, 5 insertions(+), 12 deletions(-)
>
> diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
> index b27892d971..f2241d8174 100644
> --- a/target/arm/translate-a64.c
> +++ b/target/arm/translate-a64.c
> @@ -5356,31 +5356,24 @@ static void handle_fmov(DisasContext *s, int rd, int rn, int type, bool itof)
>
>      if (itof) {
>          TCGv_i64 tcg_rn = cpu_reg(s, rn);
> +        TCGv_i64 tmp;
>
>          switch (type) {
>          case 0:
> -        {
>              /* 32 bit */
> -            TCGv_i64 tmp = tcg_temp_new_i64();
> +            tmp = tcg_temp_new_i64();
>              tcg_gen_ext32u_i64(tmp, tcg_rn);
> -            tcg_gen_st_i64(tmp, cpu_env, fp_reg_offset(s, rd, MO_64));
> -            tcg_gen_movi_i64(tmp, 0);
> -            tcg_gen_st_i64(tmp, cpu_env, fp_reg_hi_offset(s, rd));
> +            write_fp_dreg(s, rd, tmp);
>              tcg_temp_free_i64(tmp);
>              break;
> -        }
>          case 1:
> -        {
>              /* 64 bit */
> -            TCGv_i64 tmp = tcg_const_i64(0);
> -            tcg_gen_st_i64(tcg_rn, cpu_env, fp_reg_offset(s, rd, MO_64));
> -            tcg_gen_st_i64(tmp, cpu_env, fp_reg_hi_offset(s, rd));
> -            tcg_temp_free_i64(tmp);
> +            write_fp_dreg(s, rd, tcg_rn);
>              break;
> -        }
>          case 2:
>              /* 64 bit to top half. */
>              tcg_gen_st_i64(tcg_rn, cpu_env, fp_reg_hi_offset(s, rd));
> +            clear_vec_high(s, true, rd);

I was going to suggest maybe a write_fp_dreg_hi() helper here but there
are only a couple of cases so:

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

>              break;
>          }
>      } else {


--
Alex Bennée