[RFC PATCH 1/6] softfloat: add uint128_to_float* conversion methods

[matheus . ferst]

From: Matheus Ferst <matheus.ferst@eldorado.org.br>

Based on parts_uint_to_float, implements parts_uint_to_float2 that
receives a 128-bit integer through a pair of uint64_t values.

Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
---
 fpu/softfloat-parts.c.inc | 19 +++++++++++++++++++
 fpu/softfloat.c           | 30 ++++++++++++++++++++++++++++++
 include/fpu/softfloat.h   |  4 ++++
 3 files changed, 53 insertions(+)

diff --git a/fpu/softfloat-parts.c.inc b/fpu/softfloat-parts.c.inc
index db3e1f393d..0bbecf835f 100644
--- a/fpu/softfloat-parts.c.inc
+++ b/fpu/softfloat-parts.c.inc
@@ -1219,6 +1219,25 @@ static void partsN(uint_to_float)(FloatPartsN *p, 
uint64_t a,
     }
 }
 
+static void partsN(uint_to_float2)(FloatPartsN *p, uint64_t hi, uint64_t lo,
+                                   int scale, float_status *status)
+{
+
+    if (hi == 0) {
+        parts_uint_to_float(p, lo, scale, status);
+    } else {
+        int shift = clz64(hi);
+        memset(p, 0, sizeof(*p));
+        scale = MIN(MAX(scale, -0x10000), 0x10000);
+        p->cls = float_class_normal;
+        p->exp = 127 - shift + scale;
+        p->frac_hi = shl_double(hi, lo, shift);
+        if (N > 64) {
+            p->frac_lo = shl_double(lo, 0, shift);
+        }
+    }
+}
+
 /*
  * Float min/max.
  */
diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 7f524d4377..980ddfe5a1 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -866,6 +866,14 @@ static void parts128_uint_to_float(FloatParts128 *p, 
uint64_t a,
 #define parts_uint_to_float(P, I, Z, S) \
     PARTS_GENERIC_64_128(uint_to_float, P)(P, I, Z, S)
 
+static void parts64_uint_to_float2(FloatParts64 *p, uint64_t hi, uint64_t lo,
+                                   int scale, float_status *s);
+static void parts128_uint_to_float2(FloatParts128 *p, uint64_t hi, uint64_t lo,
+                                    int scale, float_status *s);
+
+#define parts_uint_to_float2(P, H, L, Z, S) \
+    PARTS_GENERIC_64_128(uint_to_float2, P)(P, H, L, Z, S)
+
 static FloatParts64 *parts64_minmax(FloatParts64 *a, FloatParts64 *b,
                                     float_status *s, int flags);
 static FloatParts128 *parts128_minmax(FloatParts128 *a, FloatParts128 *b,
@@ -3888,6 +3896,15 @@ float32 uint16_to_float32(uint16_t a, float_status 
*status)
     return uint64_to_float32_scalbn(a, 0, status);
 }
 
+float64 uint128_to_float64_scalbn(uint64_t hi, uint64_t lo, int scale,
+                                  float_status *status)
+{
+    FloatParts64 p;
+
+    parts_uint_to_float2(&p, hi, lo, scale, status);
+    return float64_round_pack_canonical(&p, status);
+}
+
 float64 uint64_to_float64_scalbn(uint64_t a, int scale, float_status *status)
 {
     FloatParts64 p;
@@ -3913,6 +3930,11 @@ float64 uint16_to_float64_scalbn(uint16_t a, int scale, 
float_status *status)
     return uint64_to_float64_scalbn(a, scale, status);
 }
 
+float64 uint128_to_float64(uint64_t hi, uint64_t lo, float_status *status)
+{
+    return uint128_to_float64_scalbn(hi, lo, 0, status);
+}
+
 float64 uint64_to_float64(uint64_t a, float_status *status)
 {
     return uint64_to_float64_scalbn(a, 0, status);
@@ -3969,6 +3991,14 @@ float128 uint64_to_float128(uint64_t a, float_status 
*status)
     return float128_round_pack_canonical(&p, status);
 }
 
+float128 uint128_to_float128(uint64_t hi, uint64_t lo, float_status *status)
+{
+    FloatParts128 p;
+
+    parts128_uint_to_float2(&p, hi, lo, 0, status);
+    return float128_round_pack_canonical(&p, status);
+}
+
 /*
  * Minimum and maximum
  */
diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h
index d34b2c44d2..2ef4fec3d0 100644
--- a/include/fpu/softfloat.h
+++ b/include/fpu/softfloat.h
@@ -169,6 +169,8 @@ float64 int64_to_float64_scalbn(int64_t, int, float_status 
*status);
 float64 uint16_to_float64_scalbn(uint16_t, int, float_status *status);
 float64 uint32_to_float64_scalbn(uint32_t, int, float_status *status);
 float64 uint64_to_float64_scalbn(uint64_t, int, float_status *status);
+float64 uint128_to_float64_scalbn(uint64_t, uint64_t, int,
+                                  float_status *status);
 
 float64 int16_to_float64(int16_t, float_status *status);
 float64 int32_to_float64(int32_t, float_status *status);
@@ -176,6 +178,7 @@ float64 int64_to_float64(int64_t, float_status *status);
 float64 uint16_to_float64(uint16_t, float_status *status);
 float64 uint32_to_float64(uint32_t, float_status *status);
 float64 uint64_to_float64(uint64_t, float_status *status);
+float64 uint128_to_float64(uint64_t, uint64_t, float_status *status);
 
 floatx80 int32_to_floatx80(int32_t, float_status *status);
 floatx80 int64_to_floatx80(int64_t, float_status *status);
@@ -183,6 +186,7 @@ floatx80 int64_to_floatx80(int64_t, float_status *status);
 float128 int32_to_float128(int32_t, float_status *status);
 float128 int64_to_float128(int64_t, float_status *status);
 float128 uint64_to_float128(uint64_t, float_status *status);
+float128 uint128_to_float128(uint64_t, uint64_t, float_status *status);
 
 /*----------------------------------------------------------------------------
 | Software half-precision conversion routines.
-- 
2.25.1