Re: [PATCH v3 01/33] target/alpha: Use array for FPCR_DYN conversion

[Philippe Mathieu-Daudé]

On 9/24/19 11:00 PM, Alex Bennée wrote:
> From: Richard Henderson <address@hidden>
> 
> This is a bit more straight-forward than using a switch statement.
> No functional change.
> 
> Signed-off-by: Richard Henderson <address@hidden>
> Signed-off-by: Alex Bennée <address@hidden>
> Message-Id: <address@hidden>

Reviewed-by: Philippe Mathieu-Daudé <address@hidden>

> ---
>  target/alpha/helper.c | 24 ++++++++----------------
>  1 file changed, 8 insertions(+), 16 deletions(-)
> 
> diff --git a/target/alpha/helper.c b/target/alpha/helper.c
> index 19cda0a2db5..6c1703682e0 100644
> --- a/target/alpha/helper.c
> +++ b/target/alpha/helper.c
> @@ -36,6 +36,13 @@ uint64_t cpu_alpha_load_fpcr(CPUAlphaState *env)
>  
>  void cpu_alpha_store_fpcr(CPUAlphaState *env, uint64_t val)
>  {
> +    static const uint8_t rm_map[] = {
> +        [FPCR_DYN_NORMAL >> FPCR_DYN_SHIFT] = float_round_nearest_even,
> +        [FPCR_DYN_CHOPPED >> FPCR_DYN_SHIFT] = float_round_to_zero,
> +        [FPCR_DYN_MINUS >> FPCR_DYN_SHIFT] = float_round_down,
> +        [FPCR_DYN_PLUS >> FPCR_DYN_SHIFT] = float_round_up,
> +    };
> +
>      uint32_t fpcr = val >> 32;
>      uint32_t t = 0;
>  
> @@ -48,22 +55,7 @@ void cpu_alpha_store_fpcr(CPUAlphaState *env, uint64_t val)
>      env->fpcr = fpcr;
>      env->fpcr_exc_enable = ~t & FPCR_STATUS_MASK;
>  
> -    switch (fpcr & FPCR_DYN_MASK) {
> -    case FPCR_DYN_NORMAL:
> -    default:
> -        t = float_round_nearest_even;
> -        break;
> -    case FPCR_DYN_CHOPPED:
> -        t = float_round_to_zero;
> -        break;
> -    case FPCR_DYN_MINUS:
> -        t = float_round_down;
> -        break;
> -    case FPCR_DYN_PLUS:
> -        t = float_round_up;
> -        break;
> -    }
> -    env->fpcr_dyn_round = t;
> +    env->fpcr_dyn_round = rm_map[(fpcr & FPCR_DYN_MASK) >> FPCR_DYN_SHIFT];
>  
>      env->fpcr_flush_to_zero = (fpcr & FPCR_UNFD) && (fpcr & FPCR_UNDZ);
>      env->fp_status.flush_inputs_to_zero = (fpcr & FPCR_DNZ) != 0;
>