From 2f18bbf9844ad110e0e69ad22708f37cab1557f6 Mon Sep 17 00:00:00 2001 From: Tom Musta Date: Tue, 7 Jan 2014 17:17:50 +0000 Subject: 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. Signed-off-by: Tom Musta Reviewed-by: Peter Maydell [PMM: removed harmless but silly int64_t casts] Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson --- fpu/softfloat.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) (limited to 'fpu') diff --git a/fpu/softfloat.c b/fpu/softfloat.c index d2e909593f..c2c1a5650b 100644 --- a/fpu/softfloat.c +++ b/fpu/softfloat.c @@ -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 -- cgit v1.2.1