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authorTom Musta <tommusta@gmail.com>2013-12-20 11:15:50 +0000
committerPeter Maydell <peter.maydell@linaro.org>2013-12-31 01:08:57 +0000
commitb9302ffe78f95a052a485be7aa7f4eabbb5aed68 (patch)
treea2d0c4ac8defeac7fd4de5137ab2281771f4c9e1
parente2b63f6486eefb286a2424b212778665916549e9 (diff)
downloadqemu-arm-b9302ffe78f95a052a485be7aa7f4eabbb5aed68.tar.gz
softfloat: Add float32_to_uint64()
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. V2: Reduced patch to just this single routine per feedback from Peter Maydell. V4: Now passing sign to roundAndPackUint64() Signed-off-by: Tom Musta <tommusta@gmail.com> Message-id: 1387397961-4894-3-git-send-email-tommusta@gmail.com PMM notes: * signed NaNs again * not convinced about handling of negative-but-round-to-zero inputs
-rw-r--r--fpu/softfloat.c45
-rw-r--r--include/fpu/softfloat.h1
2 files changed, 46 insertions, 0 deletions
diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 1af6ca56e5..af371649cd 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -1558,6 +1558,51 @@ 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, zero is
+| returned.
+*----------------------------------------------------------------------------*/
+
+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) {
+ if (aExp) {
+ float_raise(float_flag_invalid STATUS_VAR);
+ } else if (aSig) { /* negative denormalized */
+ float_raise(float_flag_inexact STATUS_VAR);
+ }
+ return 0;
+ }
+ shiftCount = 0xBE - aExp;
+ if (aExp) {
+ aSig |= 0x00800000;
+ }
+ if (shiftCount < 0) {
+ float_raise(float_flag_invalid STATUS_VAR);
+ return (int64_t)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
| performed according to the IEC/IEEE Standard for Binary Floating-Point
| Arithmetic, except that the conversion is always rounded toward zero. If
diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h
index 3790b10b3c..c49e836424 100644
--- a/include/fpu/softfloat.h
+++ b/include/fpu/softfloat.h
@@ -291,6 +291,7 @@ 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 );