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

Rename to parts$N_float_to_sint.  Reimplement
float128_to_int{32,64}{_round_to_zero} with FloatParts128.

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

1 files changed, 64 insertions, 0 deletions

diff --git a/fpu/softfloat-parts.c.inc b/fpu/softfloat-parts.c.inc
index b2c4624d8c..a897a5a743 100644
--- a/fpu/softfloat-parts.c.inc
+++ b/fpu/softfloat-parts.c.inc
@@ -751,3 +751,67 @@ static void partsN(round_to_int)(FloatPartsN *a, FloatRoundMode rmode,
         g_assert_not_reached();
     }
 }
+
+/*
+ * Returns the result of converting the floating-point value `a' to
+ * the two's complement 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 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)
+{
+    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 ? min : 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->exp <= DECOMPOSED_BINARY_POINT) {
+            r = p->frac_hi >> (DECOMPOSED_BINARY_POINT - p->exp);
+        } else {
+            r = UINT64_MAX;
+        }
+        if (p->sign) {
+            if (r <= -(uint64_t)min) {
+                r = -r;
+            } else {
+                flags = float_flag_invalid;
+                r = min;
+            }
+        } else if (r > max) {
+            flags = float_flag_invalid;
+            r = max;
+        }
+        break;
+
+    default:
+        g_assert_not_reached();
+    }
+
+    float_raise(flags, s);
+    return r;
+}