Re: [PATCH v12 3/7] [RISCV_PM] Support CSRs required for RISC-V PM extension except for the h-mode

[Richard Henderson]

On 9/28/21 3:00 PM, Alexey Baturo wrote:
> +    switch (env->priv) {
> +    case PRV_M:
> +        cur_bit_pos = M_PM_CURRENT;
> +        break;
> +    case PRV_S:
> +        cur_bit_pos = S_PM_CURRENT;
> +        break;
> +    case PRV_U:
> +        cur_bit_pos = U_PM_CURRENT;
> +        break;
> +    default:
> +        g_assert_not_reached();
> +    }
> +    pm_current = get_field(env->mmte, cur_bit_pos);

Nit: If you have a look at what the get_field macro does, you'll see that you always want 
to give it a constant, so the compiler can fold all of the arithmetic into a constant 
bitfield extract.  It is not a win to pull the field argument out into a variable like this.

For this reason I prefer the hw/registerfields.h interface -- it is more 
difficult to misuse.


r~