Re: [PATCH v3 09/13] target/riscv/insn_trans/trans_rvv.c.inc: use 'vlenb' in MAXSZ()

[Alistair Francis]

On Wed, Jan 17, 2024 at 7:02 AM Daniel Henrique Barboza
<dbarboza@ventanamicro.com> wrote:
>
> Calculate the maximum vector size possible, 'max_sz', which is the size
> in bytes 'vlenb' multiplied by the max value of LMUL (LMUL = 8, when
> s->lmul = 3).
>
> 'max_sz' is then shifted right by 'scale', expressed as '3 - s->lmul',
> which is clearer than doing 'scale = lmul - 3' and then using '-scale'
> in the shift right.
>
> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

Alistair

> ---
>  target/riscv/insn_trans/trans_rvv.c.inc | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/target/riscv/insn_trans/trans_rvv.c.inc 
> b/target/riscv/insn_trans/trans_rvv.c.inc
> index d743675262..b4663b6e1f 100644
> --- a/target/riscv/insn_trans/trans_rvv.c.inc
> +++ b/target/riscv/insn_trans/trans_rvv.c.inc
> @@ -1160,12 +1160,12 @@ GEN_LDST_WHOLE_TRANS(vs8r_v, 8, 1, true)
>  /*
>   * MAXSZ returns the maximum vector size can be operated in bytes,
>   * which is used in GVEC IR when vl_eq_vlmax flag is set to true
> - * to accerlate vector operation.
> + * to accelerate vector operation.
>   */
>  static inline uint32_t MAXSZ(DisasContext *s)
>  {
> -    int scale = s->lmul - 3;
> -    return s->cfg_ptr->vlen >> -scale;
> +    int max_sz = s->cfg_ptr->vlenb * 8;
> +    return max_sz >> (3 - s->lmul);
>  }
>
>  static bool opivv_check(DisasContext *s, arg_rmrr *a)
> --
> 2.43.0
>
>