Re: [PATCH 09/13] target/riscv/cpu.h: use 'vlenb' in vext_get_vlmax()

[Richard Henderson]

On 1/13/24 08:38, Daniel Henrique Barboza wrote:
> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> ---
>   target/riscv/cpu.h | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> index 11df226a00..628ef67d5f 100644
> --- a/target/riscv/cpu.h
> +++ b/target/riscv/cpu.h
> @@ -692,7 +692,8 @@ static inline uint32_t vext_get_vlmax(RISCVCPU *cpu, 
> target_ulong vtype)
>   {
>       uint8_t sew = FIELD_EX64(vtype, VTYPE, VSEW);
>       int8_t lmul = sextract32(FIELD_EX64(vtype, VTYPE, VLMUL), 0, 3);
> -    return cpu->cfg.vlen >> (sew + 3 - lmul);
> +    /* vlen = vlenb << 3 */
> +    return (cpu->cfg.vlenb << 3) >> (sew + 3 - lmul);
>   }

Better to simplify the arithmetic:

-    return cpu->cfg.vlen >> (sew + 3 - lmul);
+    return cpu->cfg.vlenb >> (sew - lmul);


r~