Re: [PATCH v2 05/10] softfloat: Inline pick_nan_muladd into its caller

[Alex Bennée]

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

> Because of FloatParts, there will only ever be one caller.

Isn't that admitting defeat - after all the logic here will be the same
as the login in the up coming float128_muladd code and we only seem to
need additional information:

> Inlining allows us to re-use abc_mask for the snan test.

couldn't we just pass the masks in?

<snip>
> -    if (is_snan(a.cls)) {
> -        return parts_silence_nan(a, s);
> -    }
> -    return a;

here.

> -}
> -
>  /*
>   * Returns the result of adding or subtracting the values of the
>   * floating-point values `a' and `b'. The operation is performed
> @@ -1366,7 +1327,41 @@ static FloatParts muladd_floats(FloatParts a, 
> FloatParts b, FloatParts c,
>       * off to the target-specific pick-a-NaN routine.
>       */
>      if (unlikely(abc_mask & float_cmask_anynan)) {
> -        return pick_nan_muladd(a, b, c, inf_zero, s);
> +        int which;
> +
> +        if (unlikely(abc_mask & float_cmask_snan)) {
> +            float_raise(float_flag_invalid, s);
> +        }
> +
> +        which = pickNaNMulAdd(a.cls, b.cls, c.cls, inf_zero, s);
> +
> +        if (s->default_nan_mode) {
> +            /*
> +             * Note that this check is after pickNaNMulAdd so that function
> +             * has an opportunity to set the Invalid flag for inf_zero.
> +             */
> +            which = 3;
> +        }
> +
> +        switch (which) {
> +        case 0:
> +            break;
> +        case 1:
> +            a = b;
> +            break;
> +        case 2:
> +            a = c;
> +            break;
> +        case 3:
> +            return parts_default_nan(s);
> +        default:
> +            g_assert_not_reached();
> +        }
> +
> +        if (is_snan(a.cls)) {
> +            return parts_silence_nan(a, s);
> +        }
> +        return a;
>      }
>  
>      if (unlikely(inf_zero)) {

I'm not totally against it given it's fairly simple logic but it seems a
shame to loose the commonality of processing which makes the parts code
so much nicer.

-- 
Alex Bennée