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softfloat: Add float32_to_uint64()

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This patch adds the float32_to_uint64() routine, which converts a
32-bit floating point number to an unsigned 64 bit number.

This contribution can be licensed under either the softfloat-2a or -2b
license.

Signed-off-by: Tom Musta <tommusta@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
[PMM: removed harmless but silly int64_t casts]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
This commit is contained in:
Tom Musta 2014-01-07 17:17:50 +00:00 committed by Peter Maydell
parent 3c85c37f25
commit 2f18bbf984
2 changed files with 47 additions and 0 deletions
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46
fpu/softfloat.c
View File

@ -1557,6 +1557,52 @@ int64 float32_to_int64( float32 a STATUS_PARAM )
}
/*----------------------------------------------------------------------------
| Returns the result of converting the single-precision floating-point value
| `a' to the 64-bit 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.
*----------------------------------------------------------------------------*/
uint64 float32_to_uint64(float32 a STATUS_PARAM)
{
flag aSign;
int_fast16_t aExp, shiftCount;
uint32_t aSig;
uint64_t aSig64, aSigExtra;
a = float32_squash_input_denormal(a STATUS_VAR);
aSig = extractFloat32Frac(a);
aExp = extractFloat32Exp(a);
aSign = extractFloat32Sign(a);
if ((aSign) && (aExp > 126)) {
float_raise(float_flag_invalid STATUS_VAR);
if (float32_is_any_nan(a)) {
return LIT64(0xFFFFFFFFFFFFFFFF);
} else {
return 0;
}
}
shiftCount = 0xBE - aExp;
if (aExp) {
aSig |= 0x00800000;
}
if (shiftCount < 0) {
float_raise(float_flag_invalid STATUS_VAR);
return LIT64(0xFFFFFFFFFFFFFFFF);
}
aSig64 = aSig;
aSig64 <<= 40;
shift64ExtraRightJamming(aSig64, 0, shiftCount, &aSig64, &aSigExtra);
return roundAndPackUint64(aSign, aSig64, aSigExtra STATUS_VAR);
}
/*----------------------------------------------------------------------------
| Returns the result of converting the single-precision floating-point value
| `a' to the 64-bit two's complement integer format. The conversion is

1
include/fpu/softfloat.h
View File

@ -295,6 +295,7 @@ int32 float32_to_int32_round_to_zero( float32 STATUS_PARAM );
uint32 float32_to_uint32( float32 STATUS_PARAM );
uint32 float32_to_uint32_round_to_zero( float32 STATUS_PARAM );
int64 float32_to_int64( float32 STATUS_PARAM );
uint64 float32_to_uint64(float32 STATUS_PARAM);
int64 float32_to_int64_round_to_zero( float32 STATUS_PARAM );
float64 float32_to_float64( float32 STATUS_PARAM );
floatx80 float32_to_floatx80( float32 STATUS_PARAM );