softfloat: Move round_to_uint_and_pack to softfloat-parts.c.inc

Rename to parts$N_float_to_uint.  Reimplement
float128_to_uint{32,64}{_round_to_zero} with FloatParts128.

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

fpu/softfloat-parts.c.inc

@@ -763,7 +763,7 @@ static void partsN(round_to_int)(FloatPartsN *a, FloatRoundMode rmode,
  * the largest positive integer is returned. Otherwise, if the
  * conversion overflows, the largest integer with the same sign as `a'
  * is returned.
-*/
+ */
 static int64_t partsN(float_to_sint)(FloatPartsN *p, FloatRoundMode rmode,
                                      int scale, int64_t min, int64_t max,
                                      float_status *s)
@@ -817,3 +817,69 @@ static int64_t partsN(float_to_sint)(FloatPartsN *p, FloatRoundMode rmode,
     float_raise(flags, s);
     return r;
 }
+
+/*
+ *  Returns the result of converting the floating-point value `a' to
+ *  the unsigned integer format. The conversion is performed according
+ *  to the IEC/IEEE Standard for Binary Floating-Point
+ *  Arithmetic---which means in particular that the conversion is
+ *  rounded according to the current rounding mode. If `a' is a NaN,
+ *  the largest unsigned integer is returned. Otherwise, if the
+ *  conversion overflows, the largest unsigned integer is returned. If
+ *  the 'a' is negative, the result is rounded and zero is returned;
+ *  values that do not round to zero will raise the inexact exception
+ *  flag.
+ */
+static uint64_t partsN(float_to_uint)(FloatPartsN *p, FloatRoundMode rmode,
+                                      int scale, uint64_t max, float_status *s)
+{
+    int flags = 0;
+    uint64_t r;
+
+    switch (p->cls) {
+    case float_class_snan:
+    case float_class_qnan:
+        flags = float_flag_invalid;
+        r = max;
+        break;
+
+    case float_class_inf:
+        flags = float_flag_invalid;
+        r = p->sign ? 0 : max;
+        break;
+
+    case float_class_zero:
+        return 0;
+
+    case float_class_normal:
+        /* TODO: N - 2 is frac_size for rounding; could use input fmt. */
+        if (parts_round_to_int_normal(p, rmode, scale, N - 2)) {
+            flags = float_flag_inexact;
+            if (p->cls == float_class_zero) {
+                r = 0;
+                break;
+            }
+        }
+
+        if (p->sign) {
+            flags = float_flag_invalid;
+            r = 0;
+        } else if (p->exp > DECOMPOSED_BINARY_POINT) {
+            flags = float_flag_invalid;
+            r = max;
+        } else {
+            r = p->frac_hi >> (DECOMPOSED_BINARY_POINT - p->exp);
+            if (r > max) {
+                flags = float_flag_invalid;
+                r = max;
+            }
+        }
+        break;
+
+    default:
+        g_assert_not_reached();
+    }
+
+    float_raise(flags, s);
+    return r;
+}