[PATCH] softfpu: Generalize pick_nan_muladd to opaque structures

[Richard Henderson]

This will allow us to share code between FloatParts and FloatParts128.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
Cc: Alex Bennee <alex.bennee@linaro.org>

What do you think of this instead of inlining pick_nan_muladd
into the two muladd implementations?


r~

---
 fpu/softfloat.c | 40 ++++++++++++++++++++++++----------------
 1 file changed, 24 insertions(+), 16 deletions(-)

diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 3e625c47cd..60fdddd163 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -929,16 +929,23 @@ 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)
+/*
+ * Given pointers to A, B, C, and the respective classes, return the
+ * pointer to the structure that is the NaN result, or NULL to signal
+ * that the result is the default NaN.
+ */
+static inline void *
+pick_nan_muladd(FloatClass a_cls, FloatClass b_cls, FloatClass c_cls,
+                void *a, void *b, void *c,
+                bool inf_zero, int abc_mask, float_status *s)
 {
     int which;
 
-    if (is_snan(a.cls) || is_snan(b.cls) || is_snan(c.cls)) {
+    if (unlikely(abc_mask & float_cmask_snan)) {
         s->float_exception_flags |= float_flag_invalid;
     }
 
-    which = pickNaNMulAdd(a.cls, b.cls, c.cls, inf_zero, 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
@@ -949,23 +956,16 @@ static FloatParts pick_nan_muladd(FloatParts a, 
FloatParts b, FloatParts c,
 
     switch (which) {
     case 0:
-        break;
+        return a;
     case 1:
-        a = b;
-        break;
+        return b;
     case 2:
-        a = c;
-        break;
+        return c;
     case 3:
-        return parts_default_nan(s);
+        return NULL;
     default:
         g_assert_not_reached();
     }
-
-    if (is_snan(a.cls)) {
-        return parts_silence_nan(a, s);
-    }
-    return a;
 }
 
 /*
@@ -1366,7 +1366,15 @@ 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);
+        FloatParts *r = pick_nan_muladd(a.cls, b.cls, c.cls, &a, &b, &c,
+                                        inf_zero, abc_mask, s);
+        if (r == NULL) {
+            return parts_default_nan(s);
+        }
+        if (is_snan(r->cls)) {
+            return parts_silence_nan(*r, s);
+        }
+        return *r;
     }
 
     if (unlikely(inf_zero)) {
-- 
2.25.1