diff mbox

[02/22] softfloat: Add float to 16bit integer conversions.

Message ID 1388496958-3542-3-git-send-email-peter.maydell@linaro.org
State Accepted
Commit f581bf5474d2319ca37484eb63208017ac96ce0a
Headers show

Commit Message

Peter Maydell Dec. 31, 2013, 1:35 p.m. UTC 
From: Will Newton <will.newton@linaro.org>

ARMv8 requires support for converting 32 and 64bit floating point
values to signed and unsigned 16bit integers.

Signed-off-by: Will Newton <will.newton@linaro.org>
[PMM: updated not to incorrectly set Inexact for Invalid inputs]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 fpu/softfloat.c         | 80 +++++++++++++++++++++++++++++++++++++++++++++++++
 include/fpu/softfloat.h |  4 +++
 2 files changed, 84 insertions(+)

Comments

Peter Maydell Dec. 31, 2013, 2:22 p.m. UTC | #1 
On 31 December 2013 14:18, Richard Henderson <rth@twiddle.net> wrote:
> On 12/31/2013 05:35 AM, Peter Maydell wrote:
>> +    int64_t v;
>> +    int_fast16_t res;
>> +    int old_exc_flags = get_float_exception_flags(status);
>> +
>> +    v = float32_to_int64(a STATUS_VAR);
>
> Any good reason not to use int32 as the intermediate, for the benefit of 32-bit
> hosts?

You mean 'v'? Making v less than 64 bits will give wrong results
for input values which fit in a 64 bit int but not a 32 bit int, won't it?
Or do you mean we should call float32_to_int32() instead?
I think that ought to work...

thanks
-- PMM
diff mbox

Patch

diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 6a6b656..e078539 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -6491,6 +6491,46 @@  uint32 float32_to_uint32_round_to_zero( float32 a STATUS_PARAM )
     return res;
 }
 
+int_fast16_t float32_to_int16(float32 a STATUS_PARAM)
+{
+    int64_t v;
+    int_fast16_t res;
+    int old_exc_flags = get_float_exception_flags(status);
+
+    v = float32_to_int64(a STATUS_VAR);
+    if (v < -0x8000) {
+        res = -0x8000;
+    } else if (v > 0x7fff) {
+        res = 0x7fff;
+    } else {
+        return v;
+    }
+
+    set_float_exception_flags(old_exc_flags, status);
+    float_raise(float_flag_invalid STATUS_VAR);
+    return res;
+}
+
+uint_fast16_t float32_to_uint16(float32 a STATUS_PARAM)
+{
+    int64_t v;
+    uint_fast16_t res;
+    int old_exc_flags = get_float_exception_flags(status);
+
+    v = float32_to_int64(a STATUS_VAR);
+    if (v < 0) {
+        res = 0;
+    } else if (v > 0xffff) {
+        res = 0xffff;
+    } else {
+        return v;
+    }
+
+    set_float_exception_flags(old_exc_flags, status);
+    float_raise(float_flag_invalid STATUS_VAR);
+    return res;
+}
+
 uint_fast16_t float32_to_uint16_round_to_zero(float32 a STATUS_PARAM)
 {
     int64_t v;
@@ -6545,6 +6585,46 @@  uint32 float64_to_uint32_round_to_zero( float64 a STATUS_PARAM )
     return res;
 }
 
+int_fast16_t float64_to_int16(float64 a STATUS_PARAM)
+{
+    int64_t v;
+    int_fast16_t res;
+    int old_exc_flags = get_float_exception_flags(status);
+
+    v = float64_to_int64(a STATUS_VAR);
+    if (v < -0x8000) {
+        res = -0x8000;
+    } else if (v > 0x7fff) {
+        res = 0x7fff;
+    } else {
+        return v;
+    }
+
+    set_float_exception_flags(old_exc_flags, status);
+    float_raise(float_flag_invalid STATUS_VAR);
+    return res;
+}
+
+uint_fast16_t float64_to_uint16(float64 a STATUS_PARAM)
+{
+    int64_t v;
+    uint_fast16_t res;
+    int old_exc_flags = get_float_exception_flags(status);
+
+    v = float64_to_int64(a STATUS_VAR);
+    if (v < 0) {
+        res = 0;
+    } else if (v > 0xffff) {
+        res = 0xffff;
+    } else {
+        return v;
+    }
+
+    set_float_exception_flags(old_exc_flags, status);
+    float_raise(float_flag_invalid STATUS_VAR);
+    return res;
+}
+
 uint_fast16_t float64_to_uint16_round_to_zero(float64 a STATUS_PARAM)
 {
     int64_t v;
diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h
index 2365274..a9b8cd9 100644
--- a/include/fpu/softfloat.h
+++ b/include/fpu/softfloat.h
@@ -265,6 +265,8 @@  extern const float16 float16_default_nan;
 /*----------------------------------------------------------------------------
 | Software IEC/IEEE single-precision conversion routines.
 *----------------------------------------------------------------------------*/
+int_fast16_t float32_to_int16(float32 STATUS_PARAM);
+uint_fast16_t float32_to_uint16(float32 STATUS_PARAM);
 int_fast16_t float32_to_int16_round_to_zero(float32 STATUS_PARAM);
 uint_fast16_t float32_to_uint16_round_to_zero(float32 STATUS_PARAM);
 int32 float32_to_int32( float32 STATUS_PARAM );
@@ -371,6 +373,8 @@  extern const float32 float32_default_nan;
 /*----------------------------------------------------------------------------
 | Software IEC/IEEE double-precision conversion routines.
 *----------------------------------------------------------------------------*/
+int_fast16_t float64_to_int16(float64 STATUS_PARAM);
+uint_fast16_t float64_to_uint16(float64 STATUS_PARAM);
 int_fast16_t float64_to_int16_round_to_zero(float64 STATUS_PARAM);
 uint_fast16_t float64_to_uint16_round_to_zero(float64 STATUS_PARAM);
 int32 float64_to_int32( float64 STATUS_PARAM );