[RFC v2 70/76] softfloat: add fp16 and uint8/int8 interconvert functions

[frank . chang]

From: Frank Chang <frank.chang@sifive.com>

Signed-off-by: Frank Chang <frank.chang@sifive.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
---
 fpu/softfloat.c         | 34 ++++++++++++++++++++++++++++++++++
 include/fpu/softfloat.h |  8 ++++++++
 2 files changed, 42 insertions(+)

diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index e1661f22a5..89634267db 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -2142,6 +2142,13 @@ static int64_t round_to_int_and_pack(FloatParts in, 
FloatRoundMode rmode,
     }
 }
 
+int8_t float16_to_int8_scalbn(float16 a, FloatRoundMode rmode, int scale,
+                              float_status *s)
+{
+    return round_to_int_and_pack(float16_unpack_canonical(a, s),
+                                 rmode, scale, INT8_MIN, INT8_MAX, s);
+}
+
 int16_t float16_to_int16_scalbn(float16 a, FloatRoundMode rmode, int scale,
                                 float_status *s)
 {
@@ -2205,6 +2212,11 @@ int64_t float64_to_int64_scalbn(float64 a, 
FloatRoundMode rmode, int scale,
                                  rmode, scale, INT64_MIN, INT64_MAX, s);
 }
 
+int8_t float16_to_int8(float16 a, float_status *s)
+{
+    return float16_to_int8_scalbn(a, s->float_rounding_mode, 0, s);
+}
+
 int16_t float16_to_int16(float16 a, float_status *s)
 {
     return float16_to_int16_scalbn(a, s->float_rounding_mode, 0, s);
@@ -2355,6 +2367,13 @@ static uint64_t round_to_uint_and_pack(FloatParts in, 
FloatRoundMode rmode,
     }
 }
 
+uint8_t float16_to_uint8_scalbn(float16 a, FloatRoundMode rmode, int scale,
+                                float_status *s)
+{
+    return round_to_uint_and_pack(float16_unpack_canonical(a, s),
+                                  rmode, scale, UINT8_MAX, s);
+}
+
 uint16_t float16_to_uint16_scalbn(float16 a, FloatRoundMode rmode, int scale,
                                   float_status *s)
 {
@@ -2418,6 +2437,11 @@ uint64_t float64_to_uint64_scalbn(float64 a, 
FloatRoundMode rmode, int scale,
                                   rmode, scale, UINT64_MAX, s);
 }
 
+uint8_t float16_to_uint8(float16 a, float_status *s)
+{
+    return float16_to_uint8_scalbn(a, s->float_rounding_mode, 0, s);
+}
+
 uint16_t float16_to_uint16(float16 a, float_status *s)
 {
     return float16_to_uint16_scalbn(a, s->float_rounding_mode, 0, s);
@@ -2572,6 +2596,11 @@ float16 int16_to_float16(int16_t a, float_status *status)
     return int64_to_float16_scalbn(a, 0, status);
 }
 
+float16 int8_to_float16(int8_t a, float_status *status)
+{
+    return int64_to_float16_scalbn(a, 0, status);
+}
+
 float32 int64_to_float32_scalbn(int64_t a, int scale, float_status *status)
 {
     FloatParts pa = int_to_float(a, scale, status);
@@ -2697,6 +2726,11 @@ float16 uint16_to_float16(uint16_t a, float_status 
*status)
     return uint64_to_float16_scalbn(a, 0, status);
 }
 
+float16 uint8_to_float16(uint8_t a, float_status *status)
+{
+    return uint64_to_float16_scalbn(a, 0, status);
+}
+
 float32 uint64_to_float32_scalbn(uint64_t a, int scale, float_status *status)
 {
     FloatParts pa = uint_to_float(a, scale, status);
diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h
index 078cad8ad9..5700d2024b 100644
--- a/include/fpu/softfloat.h
+++ b/include/fpu/softfloat.h
@@ -136,9 +136,11 @@ float16 uint16_to_float16_scalbn(uint16_t a, int, 
float_status *status);
 float16 uint32_to_float16_scalbn(uint32_t a, int, float_status *status);
 float16 uint64_to_float16_scalbn(uint64_t a, int, float_status *status);
 
+float16 int8_to_float16(int8_t a, float_status *status);
 float16 int16_to_float16(int16_t a, float_status *status);
 float16 int32_to_float16(int32_t a, float_status *status);
 float16 int64_to_float16(int64_t a, float_status *status);
+float16 uint8_to_float16(uint8_t a, float_status *status);
 float16 uint16_to_float16(uint16_t a, float_status *status);
 float16 uint32_to_float16(uint32_t a, float_status *status);
 float16 uint64_to_float16(uint64_t a, float_status *status);
@@ -187,10 +189,13 @@ float32 float16_to_float32(float16, bool ieee, 
float_status *status);
 float16 float64_to_float16(float64 a, bool ieee, float_status *status);
 float64 float16_to_float64(float16 a, bool ieee, float_status *status);
 
+int8_t  float16_to_int8_scalbn(float16, FloatRoundMode, int,
+                               float_status *status);
 int16_t float16_to_int16_scalbn(float16, FloatRoundMode, int, float_status *);
 int32_t float16_to_int32_scalbn(float16, FloatRoundMode, int, float_status *);
 int64_t float16_to_int64_scalbn(float16, FloatRoundMode, int, float_status *);
 
+int8_t  float16_to_int8(float16, float_status *status);
 int16_t float16_to_int16(float16, float_status *status);
 int32_t float16_to_int32(float16, float_status *status);
 int64_t float16_to_int64(float16, float_status *status);
@@ -199,6 +204,8 @@ int16_t float16_to_int16_round_to_zero(float16, 
float_status *status);
 int32_t float16_to_int32_round_to_zero(float16, float_status *status);
 int64_t float16_to_int64_round_to_zero(float16, float_status *status);
 
+uint8_t float16_to_uint8_scalbn(float16 a, FloatRoundMode,
+                                int, float_status *status);
 uint16_t float16_to_uint16_scalbn(float16 a, FloatRoundMode,
                                   int, float_status *status);
 uint32_t float16_to_uint32_scalbn(float16 a, FloatRoundMode,
@@ -206,6 +213,7 @@ uint32_t float16_to_uint32_scalbn(float16 a, FloatRoundMode,
 uint64_t float16_to_uint64_scalbn(float16 a, FloatRoundMode,
                                   int, float_status *status);
 
+uint8_t  float16_to_uint8(float16 a, float_status *status);
 uint16_t float16_to_uint16(float16 a, float_status *status);
 uint32_t float16_to_uint32(float16 a, float_status *status);
 uint64_t float16_to_uint64(float16 a, float_status *status);
-- 
2.17.1