diff mbox series

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

Message ID 20200925152047.709901-6-richard.henderson@linaro.org
State New
Headers show
Series softfloat: Implement float128_muladd | expand

Commit Message

Richard Henderson Sept. 25, 2020, 3:20 p.m. UTC 
Because of FloatParts, there will only ever be one caller.
Inlining allows us to re-use abc_mask for the snan test.

Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 fpu/softfloat.c | 75 +++++++++++++++++++++++--------------------------
 1 file changed, 35 insertions(+), 40 deletions(-)

Comments

Alex Bennée Oct. 16, 2020, 4:20 p.m. UTC | #1 
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.
Richard Henderson Oct. 16, 2020, 4:36 p.m. UTC | #2 
On 10/16/20 9:20 AM, Alex Bennée wrote:
> 
> 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...


Well, that and passing around a completely different structure.
Which is the big stop.  Any suggestions for that?


r~
diff mbox series

Patch

diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 3e625c47cd..e038434a07 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -929,45 +929,6 @@  static FloatParts pick_nan(FloatParts a, FloatParts b, float_status *s)
     return a;
 }
 
-static FloatParts pick_nan_muladd(FloatParts a, FloatParts b, FloatParts c,
-                                  bool inf_zero, float_status *s)
-{
-    int which;
-
-    if (is_snan(a.cls) || is_snan(b.cls) || is_snan(c.cls)) {
-        s->float_exception_flags |= float_flag_invalid;
-    }
-
-    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.
-         */
-        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;
-}
-
 /*
  * 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)) {