Bochs/bochs/cpu/fpu/softfloat.cc

/*============================================================================
This C source file is part of the SoftFloat IEC/IEEE Floating-point Arithmetic
Package, Release 2b.

Written by John R. Hauser.  This work was made possible in part by the
International Computer Science Institute, located at Suite 600, 1947 Center
Street, Berkeley, California 94704.  Funding was partially provided by the
National Science Foundation under grant MIP-9311980.  The original version
of this code was written as part of a project to build a fixed-point vector
processor in collaboration with the University of California at Berkeley,
overseen by Profs. Nelson Morgan and John Wawrzynek.  More information
is available through the Web page `http://www.cs.berkeley.edu/~jhauser/
arithmetic/SoftFloat.html'.

THIS SOFTWARE IS DISTRIBUTED AS IS, FOR FREE.  Although reasonable effort has
been made to avoid it, THIS SOFTWARE MAY CONTAIN FAULTS THAT WILL AT TIMES
RESULT IN INCORRECT BEHAVIOR.  USE OF THIS SOFTWARE IS RESTRICTED TO PERSONS
AND ORGANIZATIONS WHO CAN AND WILL TAKE FULL RESPONSIBILITY FOR ALL LOSSES,
COSTS, OR OTHER PROBLEMS THEY INCUR DUE TO THE SOFTWARE, AND WHO FURTHERMORE
EFFECTIVELY INDEMNIFY JOHN HAUSER AND THE INTERNATIONAL COMPUTER SCIENCE
INSTITUTE (possibly via similar legal warning) AGAINST ALL LOSSES, COSTS, OR
OTHER PROBLEMS INCURRED BY THEIR CUSTOMERS AND CLIENTS DUE TO THE SOFTWARE.

Derivative works are acceptable, even for commercial purposes, so long as
(1) the source code for the derivative work includes prominent notice that
the work is derivative, and (2) the source code includes prominent notice with
these four paragraphs for those parts of this code that are retained.
=============================================================================*/

#define FLOAT128

/*============================================================================
 * Adapted for Bochs (x86 achitecture simulator) by
 *            Stanislav Shwartsman [sshwarts at sourceforge net]
 * ==========================================================================*/

#include "softfloat.h"
#include "softfloat-round-pack.h"

/*----------------------------------------------------------------------------
| Primitive arithmetic functions, including multi-word arithmetic, and
| division and square root approximations. (Can be specialized to target
| if desired).
*----------------------------------------------------------------------------*/
#define USE_estimateDiv128To64
#define USE_estimateSqrt32
#include "softfloat-macros.h"

/*----------------------------------------------------------------------------
| Functions and definitions to determine:  (1) whether tininess for underflow
| is detected before or after rounding by default, (2) what (if anything)
| happens when exceptions are raised, (3) how signaling NaNs are distinguished
| from quiet NaNs, (4) the default generated quiet NaNs, and (5) how NaNs
| are propagated from function inputs to output.  These details are target-
| specific.
*----------------------------------------------------------------------------*/
#include "softfloat-specialize.h"

/*----------------------------------------------------------------------------
| Returns the result of converting the 32-bit two's complement integer `a'
| to the single-precision floating-point format.  The conversion is performed
| according to the IEC/IEEE Standard for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float32 int32_to_float32(Bit32s a, float_status_t &status)
{
    if (a == 0) return 0;
    if (a == (Bit32s) 0x80000000) return packFloat32(1, 0x9E, 0);
    int zSign = (a < 0);
    return normalizeRoundAndPackFloat32(zSign, 0x9C, zSign ? -a : a, status);
}

/*----------------------------------------------------------------------------
| Returns the result of converting the 32-bit two's complement integer `a'
| to the double-precision floating-point format.  The conversion is performed
| according to the IEC/IEEE Standard for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float64 int32_to_float64(Bit32s a)
{
    if (a == 0) return 0;
    int zSign = (a < 0);
    Bit32u absA = zSign ? -a : a;
    int shiftCount = countLeadingZeros32(absA) + 21;
    Bit64u zSig = absA;
    return packFloat64(zSign, 0x432 - shiftCount, zSig<<shiftCount);
}

/*----------------------------------------------------------------------------
| Returns the result of converting the 64-bit two's complement integer `a'
| to the single-precision floating-point format.  The conversion is performed
| according to the IEC/IEEE Standard for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float32 int64_to_float32(Bit64s a, float_status_t &status)
{
    if (a == 0) return 0;
    int zSign = (a < 0);
    Bit64u absA = zSign ? -a : a;
    int shiftCount = countLeadingZeros64(absA) - 40;
    if (0 <= shiftCount) {
        return packFloat32(zSign, 0x95 - shiftCount, (Bit32u)(absA<<shiftCount));
    }
    else {
        shiftCount += 7;
        if (shiftCount < 0) {
            absA = shift64RightJamming(absA, -shiftCount);
        }
        else {
            absA <<= shiftCount;
        }
        return roundAndPackFloat32(zSign, 0x9C - shiftCount, (Bit32u) absA, status);
    }
}

/*----------------------------------------------------------------------------
| Returns the result of converting the 64-bit two's complement integer `a'
| to the double-precision floating-point format.  The conversion is performed
| according to the IEC/IEEE Standard for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float64 int64_to_float64(Bit64s a, float_status_t &status)
{
    if (a == 0) return 0;
    if (a == (Bit64s) BX_CONST64(0x8000000000000000)) {
        return packFloat64(1, 0x43E, 0);
    }
    int zSign = (a < 0);
    return normalizeRoundAndPackFloat64(zSign, 0x43C, zSign ? -a : a, status);
}

/*----------------------------------------------------------------------------
| Returns the result of converting the 32-bit unsigned integer `a' to the
| single-precision floating-point format.  The conversion is performed
| according to the IEC/IEEE Standard for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float32 uint32_to_float32(Bit32u a, float_status_t &status)
{
    if (a == 0) return 0;
    if (a & 0x80000000) return normalizeRoundAndPackFloat32(0, 0x9D, a >> 1, status);
    return normalizeRoundAndPackFloat32(0, 0x9C, a, status);
}

/*----------------------------------------------------------------------------
| Returns the result of converting the 32-bit unsigned integer `a' to the
| double-precision floating-point format.  The conversion is performed
| according to the IEC/IEEE Standard for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float64 uint32_to_float64(Bit32u a)
{
   if (a == 0) return 0;
   int shiftCount = countLeadingZeros32(a) + 21;
   Bit64u zSig = a;
   return packFloat64(0, 0x432 - shiftCount, zSig<<shiftCount);
}

/*----------------------------------------------------------------------------
| Returns the result of converting the 64-bit unsigned integer integer `a'
| to the single-precision floating-point format.  The conversion is performed
| according to the IEC/IEEE Standard for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float32 uint64_to_float32(Bit64u a, float_status_t &status)
{
    if (a == 0) return 0;
    int shiftCount = countLeadingZeros64(a) - 40;
    if (0 <= shiftCount) {
        return packFloat32(0, 0x95 - shiftCount, (Bit32u)(a<<shiftCount));
    }
    else {
        shiftCount += 7;
        if (shiftCount < 0) {
            a = shift64RightJamming(a, -shiftCount);
        }
        else {
            a <<= shiftCount;
        }
        return roundAndPackFloat32(0, 0x9C - shiftCount, (Bit32u) a, status);
    }
}

/*----------------------------------------------------------------------------
| Returns the result of converting the 64-bit unsigned integer integer `a'
| to the double-precision floating-point format.  The conversion is performed
| according to the IEC/IEEE Standard for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float64 uint64_to_float64(Bit64u a, float_status_t &status)
{
    if (a == 0) return 0;
    if (a & BX_CONST64(0x8000000000000000))
        return normalizeRoundAndPackFloat64(0, 0x43D, a >> 1, status);
    return normalizeRoundAndPackFloat64(0, 0x43C, a, status);
}

/*----------------------------------------------------------------------------
| Returns the result of converting the single-precision floating-point value
| `a' to the 32-bit two's complement 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 or the
| conversion overflows the integer indefinite value is returned.
*----------------------------------------------------------------------------*/

Bit32s float32_to_int32(float32 a, float_status_t &status)
{
    Bit32u aSig = extractFloat32Frac(a);
    Bit16s aExp = extractFloat32Exp(a);
    int aSign = extractFloat32Sign(a);
    if ((aExp == 0xFF) && aSig) aSign = 0;
    if (aExp) aSig |= 0x00800000;
    else {
        if (get_denormals_are_zeros(status)) aSig = 0;
    }
    int shiftCount = 0xAF - aExp;
    Bit64u aSig64 = Bit64u(aSig) << 32;
    if (0 < shiftCount) aSig64 = shift64RightJamming(aSig64, shiftCount);
    return roundAndPackInt32(aSign, aSig64, status);
}

/*----------------------------------------------------------------------------
| Returns the result of converting the single-precision floating-point value
| `a' to the 32-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 `a' is a NaN or the conversion overflows, the integer indefinite
| value is returned.
*----------------------------------------------------------------------------*/

Bit32s float32_to_int32_round_to_zero(float32 a, float_status_t &status)
{
    int aSign;
    Bit16s aExp;
    Bit32u aSig;
    Bit32s z;

    aSig = extractFloat32Frac(a);
    aExp = extractFloat32Exp(a);
    aSign = extractFloat32Sign(a);
    int shiftCount = aExp - 0x9E;
    if (0 <= shiftCount) {
        if (a != 0xCF000000) {
            float_raise(status, float_flag_invalid);
        }
        return (Bit32s)(int32_indefinite);
    }
    else if (aExp <= 0x7E) {
        if (get_denormals_are_zeros(status) && aExp == 0) aSig = 0;
        if (aExp | aSig) float_raise(status, float_flag_inexact);
        return 0;
    }
    aSig = (aSig | 0x800000)<<8;
    z = aSig>>(-shiftCount);
    if ((Bit32u) (aSig<<(shiftCount & 31))) {
        float_raise(status, float_flag_inexact);
    }
    if (aSign) z = -z;
    return z;
}

/*----------------------------------------------------------------------------
| Returns the result of converting the single-precision floating-point value
| `a' to the 32-bit unsigned 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 `a' is a NaN
| or conversion overflows, the largest positive integer is returned.
*----------------------------------------------------------------------------*/

Bit32u float32_to_uint32_round_to_zero(float32 a, float_status_t &status)
{
    int aSign;
    Bit16s aExp;
    Bit32u aSig;

    aSig = extractFloat32Frac(a);
    aExp = extractFloat32Exp(a);
    aSign = extractFloat32Sign(a);
    int shiftCount = aExp - 0x9E;

    if (aExp <= 0x7E) {
        if (get_denormals_are_zeros(status) && aExp == 0) aSig = 0;
        if (aExp | aSig) float_raise(status, float_flag_inexact);
        return 0;
    }
    else if (0 < shiftCount || aSign) {
        float_raise(status, float_flag_invalid);
        return uint32_indefinite;
    }

    aSig = (aSig | 0x800000)<<8;
    Bit32u z = aSig >> (-shiftCount);
    if (aSig << (shiftCount & 31)) {
        float_raise(status, float_flag_inexact);
    }
    return z;
}

/*----------------------------------------------------------------------------
| 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 - which means in particular that the conversion is rounded
| according to the current rounding mode. If `a' is a NaN or the
| conversion overflows, the integer indefinite value is returned.
*----------------------------------------------------------------------------*/

Bit64s float32_to_int64(float32 a, float_status_t &status)
{
    Bit64u aSig64, aSigExtra;

    Bit32u aSig = extractFloat32Frac(a);
    Bit16s aExp = extractFloat32Exp(a);
    int aSign = extractFloat32Sign(a);

    int shiftCount = 0xBE - aExp;
    if (shiftCount < 0) {
        float_raise(status, float_flag_invalid);
        return (Bit64s)(int64_indefinite);
    }
    if (aExp) aSig |= 0x00800000;
    else {
        if (get_denormals_are_zeros(status)) aSig = 0;
    }
    aSig64 = aSig;
    aSig64 <<= 40;
    shift64ExtraRightJamming(aSig64, 0, shiftCount, &aSig64, &aSigExtra);
    return roundAndPackInt64(aSign, aSig64, aSigExtra, status);
}

/*----------------------------------------------------------------------------
| 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 `a' is a NaN or the conversion overflows, the integer indefinite
| value is returned.
*----------------------------------------------------------------------------*/

Bit64s float32_to_int64_round_to_zero(float32 a, float_status_t &status)
{
    int aSign;
    Bit16s aExp;
    Bit32u aSig;
    Bit64u aSig64;
    Bit64s z;

    aSig = extractFloat32Frac(a);
    aExp = extractFloat32Exp(a);
    aSign = extractFloat32Sign(a);
    int shiftCount = aExp - 0xBE;
    if (0 <= shiftCount) {
        if (a != 0xDF000000) {
            float_raise(status, float_flag_invalid);
        }
        return (Bit64s)(int64_indefinite);
    }
    else if (aExp <= 0x7E) {
        if (get_denormals_are_zeros(status) && aExp == 0) aSig = 0;
        if (aExp | aSig) float_raise(status, float_flag_inexact);
        return 0;
    }
    aSig64 = aSig | 0x00800000;
    aSig64 <<= 40;
    z = aSig64>>(-shiftCount);
    if ((Bit64u) (aSig64<<(shiftCount & 63))) {
        float_raise(status, float_flag_inexact);
    }
    if (aSign) z = -z;
    return z;
}

/*----------------------------------------------------------------------------
| 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,
| except that the conversion is always rounded toward zero. If `a' is a NaN
| or the conversion overflows, the largest unsigned integer is returned.
*----------------------------------------------------------------------------*/

Bit64u float32_to_uint64_round_to_zero(float32 a, float_status_t &status)
{
    int aSign;
    Bit16s aExp;
    Bit32u aSig;
    Bit64u aSig64;

    aSig = extractFloat32Frac(a);
    aExp = extractFloat32Exp(a);
    aSign = extractFloat32Sign(a);
    int shiftCount = aExp - 0xBE;

    if (aExp <= 0x7E) {
        if (get_denormals_are_zeros(status) && aExp == 0) aSig = 0;
        if (aExp | aSig) float_raise(status, float_flag_inexact);
        return 0;
    }
    else if (0 < shiftCount || aSign) {
        float_raise(status, float_flag_invalid);
        return uint64_indefinite;
    }

    aSig64 = aSig | 0x00800000;
    aSig64 <<= 40;
    Bit64u z = aSig64>>(-shiftCount);
    if ((Bit64u) (aSig64<<(shiftCount & 63))) {
        float_raise(status, float_flag_inexact);
    }
    return z;
}

/*----------------------------------------------------------------------------
| 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 or the conversion
| overflows, the largest unsigned integer is returned.
*----------------------------------------------------------------------------*/

Bit64u float32_to_uint64(float32 a, float_status_t &status)
{
    int aSign;
    Bit16s aExp, shiftCount;
    Bit32u aSig;
    Bit64u aSig64, aSigExtra;

    aSig = extractFloat32Frac(a);
    aExp = extractFloat32Exp(a);
    aSign = extractFloat32Sign(a);

    if (get_denormals_are_zeros(status)) {
        if (aExp == 0) aSig = 0;
    }

    if ((aSign) && (aExp > 0x7E)) {
        float_raise(status, float_flag_invalid);
        return uint64_indefinite;
    }

    shiftCount = 0xBE - aExp;
    if (aExp) aSig |= 0x00800000;

    if (shiftCount < 0) {
        float_raise(status, float_flag_invalid);
        return uint64_indefinite;
    }

    aSig64 = aSig;
    aSig64 <<= 40;
    shift64ExtraRightJamming(aSig64, 0, shiftCount, &aSig64, &aSigExtra);
    return roundAndPackUint64(aSign, aSig64, aSigExtra, status);
}

/*----------------------------------------------------------------------------
| Returns the result of converting the single-precision floating-point value
| `a' to the 32-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 or the conversion
| overflows, the largest unsigned integer is returned. 
*----------------------------------------------------------------------------*/

Bit32u float32_to_uint32(float32 a, float_status_t &status)
{
    Bit64u val_64 = float32_to_uint64(a, status);

    if (val_64 > 0xffffffff) {
        status.float_exception_flags = float_flag_invalid; // throw away other flags
        return uint32_indefinite;
    }

    return (Bit32u) val_64;
}

/*----------------------------------------------------------------------------
| Returns the result of converting the single-precision floating-point value
| `a' to the double-precision floating-point format.  The conversion is
| performed according to the IEC/IEEE Standard for Binary Floating-Point
| Arithmetic.
*----------------------------------------------------------------------------*/

float64 float32_to_float64(float32 a, float_status_t &status)
{
    Bit32u aSig = extractFloat32Frac(a);
    Bit16s aExp = extractFloat32Exp(a);
    int  aSign = extractFloat32Sign(a);

    if (aExp == 0xFF) {
        if (aSig) return commonNaNToFloat64(float32ToCommonNaN(a, status));
        return packFloat64(aSign, 0x7FF, 0);
    }
    if (aExp == 0) {
        if (aSig == 0 || get_denormals_are_zeros(status))
            return packFloat64(aSign, 0, 0);

        float_raise(status, float_flag_denormal);
        normalizeFloat32Subnormal(aSig, &aExp, &aSig);
        --aExp;
    }
    return packFloat64(aSign, aExp + 0x380, ((Bit64u) aSig)<<29);
}

/*----------------------------------------------------------------------------
| Rounds the single-precision floating-point value `a' to an integer, and
| returns the result as a single-precision floating-point value.  The
| operation is performed according to the IEC/IEEE Standard for Binary
| Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float32 float32_round_to_int(float32 a, Bit8u scale, float_status_t &status)
{
    Bit32u lastBitMask, roundBitsMask;
    int roundingMode = get_float_rounding_mode(status);
    Bit16s aExp = extractFloat32Exp(a);
    scale &= 0xf;

    if ((aExp == 0xFF) && extractFloat32Frac(a)) {
        return propagateFloat32NaN(a, status);
    }

    aExp += scale; // scale the exponent

    if (0x96 <= aExp) {
        return a;
    }

    if (get_denormals_are_zeros(status)) {
        a = float32_denormal_to_zero(a);
    }

    if (aExp <= 0x7E) {
        if ((Bit32u) (a<<1) == 0) return a;
        float_raise(status, float_flag_inexact);
        int aSign = extractFloat32Sign(a);
        switch (roundingMode) {
         case float_round_nearest_even:
            if ((aExp == 0x7E) && extractFloat32Frac(a)) {
                return packFloat32(aSign, 0x7F - scale, 0);
            }
            break;
         case float_round_down:
            return aSign ? packFloat32(1, 0x7F - scale, 0) : float32_positive_zero;
         case float_round_up:
            return aSign ? float32_negative_zero : packFloat32(0, 0x7F - scale, 0);
        }
        return packFloat32(aSign, 0, 0);
    }

    lastBitMask = 1;
    lastBitMask <<= 0x96 - aExp;
    roundBitsMask = lastBitMask - 1;
    float32 z = a;
    if (roundingMode == float_round_nearest_even) {
        z += lastBitMask>>1;
        if ((z & roundBitsMask) == 0) z &= ~lastBitMask;
    }
    else if (roundingMode != float_round_to_zero) {
        if (extractFloat32Sign(z) ^ (roundingMode == float_round_up)) {
            z += roundBitsMask;
        }
    }
    z &= ~roundBitsMask;
    if (z != a) float_raise(status, float_flag_inexact);
    return z;
}

/*----------------------------------------------------------------------------
| Extracts the fractional portion of single-precision floating-point value `a',
| and returns the result  as a  single-precision  floating-point value. The
| fractional results are precise. The operation is performed according to the
| IEC/IEEE Standard for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float32 float32_frc(float32 a, float_status_t &status)
{
    int roundingMode = get_float_rounding_mode(status);

    Bit16s aExp = extractFloat32Exp(a);
    Bit32u aSig = extractFloat32Frac(a);
    int aSign = extractFloat32Sign(a);

    if (aExp == 0xFF) {
        if (aSig) return propagateFloat32NaN(a, status);
        float_raise(status, float_flag_invalid);
        return float32_default_nan;
    }

    if (aExp >= 0x96) {
        return packFloat32(roundingMode == float_round_down, 0, 0);
    }

    if (aExp < 0x7F) {
        if (aExp == 0) {
            if (aSig == 0 || get_denormals_are_zeros(status))
                return packFloat32(roundingMode == float_round_down, 0, 0);

            float_raise(status, float_flag_denormal);
            if (! float_exception_masked(status, float_flag_underflow))
                float_raise(status, float_flag_underflow);

            if(get_flush_underflow_to_zero(status)) {
                float_raise(status, float_flag_underflow | float_flag_inexact);
                return packFloat32(aSign, 0, 0);
            }
        }
        return a;
    }

    Bit32u lastBitMask = 1 << (0x96 - aExp);
    Bit32u roundBitsMask = lastBitMask - 1;

    aSig &= roundBitsMask;
    aSig <<= 7;
    aExp--;

    if (aSig == 0)
       return packFloat32(roundingMode == float_round_down, 0, 0);

    return normalizeRoundAndPackFloat32(aSign, aExp, aSig, status);
}

/*----------------------------------------------------------------------------
| Extracts the exponent portion of single-precision floating-point value 'a',
| and returns the result as a single-precision floating-point value
| representing unbiased integer exponent. The operation is performed according
| to the IEC/IEEE Standard for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float32 float32_getexp(float32 a, float_status_t &status)
{
    Bit16s aExp = extractFloat32Exp(a);
    Bit32u aSig = extractFloat32Frac(a);

    if (aExp == 0xFF) {
        if (aSig) return propagateFloat32NaN(a, status);
        return float32_positive_inf;
    }

    if (aExp == 0) {
        if (aSig == 0 || get_denormals_are_zeros(status))
            return float32_negative_inf;

        float_raise(status, float_flag_denormal);
        normalizeFloat32Subnormal(aSig, &aExp, &aSig);
    }

    return int32_to_float32(aExp - 0x7F, status);
}

/*----------------------------------------------------------------------------
| Extracts the mantissa of single-precision floating-point value 'a' and
| returns the result as a single-precision floating-point after applying
| the mantissa interval normalization and sign control. The operation is
| performed according to the IEC/IEEE Standard for Binary Floating-Point
| Arithmetic.
*----------------------------------------------------------------------------*/

float32 float32_getmant(float32 a, float_status_t &status, int sign_ctrl, int interv)
{
    Bit16s aExp = extractFloat32Exp(a);
    Bit32u aSig = extractFloat32Frac(a);
    int aSign = extractFloat32Sign(a);

    if (aExp == 0xFF) {
        if (aSig) return propagateFloat32NaN(a, status);
        if (aSign) {
            if (sign_ctrl & 0x2) {
                float_raise(status, float_flag_invalid);
                return float32_default_nan;
            }
        }
        return packFloat32(~sign_ctrl & aSign, 0x7F, 0);
    }

    if (aExp == 0 && (aSig == 0 || get_denormals_are_zeros(status))) {
        return packFloat32(~sign_ctrl & aSign, 0x7F, 0);
    }

    if (aSign) {
        if (sign_ctrl & 0x2) {
            float_raise(status, float_flag_invalid);
            return float32_default_nan;
        }
    }

    if (aExp == 0) {
        float_raise(status, float_flag_denormal);
        normalizeFloat32Subnormal(aSig, &aExp, &aSig);
//      aExp += 0x7E;
        aSig &= 0x7FFFFF;
    }

    switch(interv) {
    case 0x0: // interval [1,2)
        aExp = 0x7F;
        break;
    case 0x1: // interval [1/2,2)
        aExp -= 0x7F;
        aExp  = 0x7F - (aExp & 0x1);
        break;
    case 0x2: // interval [1/2,1)
        aExp = 0x7E;
        break;
    case 0x3: // interval [3/4,3/2)
        aExp = 0x7F - ((aSig >> 22) & 0x1);
        break;
    }

    return packFloat32(~sign_ctrl & aSign, aExp, aSig);
}

/*----------------------------------------------------------------------------
| Return the result of a floating point scale of the single-precision floating
| point value `a' by multiplying it by 2 power of the single-precision
| floating point value 'b' converted to integral value. If the result cannot
| be represented in single precision, then the proper overflow response (for
| positive scaling operand), or the proper underflow response (for negative
| scaling operand) is issued. The operation is performed according to the
| IEC/IEEE Standard for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float32 float32_scalef(float32 a, float32 b, float_status_t &status)
{
    Bit32u aSig = extractFloat32Frac(a);
    Bit16s aExp = extractFloat32Exp(a);
    int aSign = extractFloat32Sign(a);
    Bit32u bSig = extractFloat32Frac(b);
    Bit16s bExp = extractFloat32Exp(b);
    int bSign = extractFloat32Sign(b);

    if (get_denormals_are_zeros(status)) {
        if (aExp == 0) aSig = 0;
        if (bExp == 0) bSig = 0;
    }

    if (bExp == 0xFF) {
        if (bSig) return propagateFloat32NaN(a, b, status);
    }

    if (aExp == 0xFF) {
        if (aSig) {
            int aIsSignalingNaN = (aSig & 0x00400000) == 0;
            if (aIsSignalingNaN || bExp != 0xFF || bSig)
                return propagateFloat32NaN(a, b, status);

            return bSign ? 0 : float32_positive_inf;
        }

        if (bExp == 0xFF && bSign) {
            float_raise(status, float_flag_invalid);
            return float32_default_nan;
        }
        return a;
    }

    if (aExp == 0) {
        if (aSig == 0) {
            if (bExp == 0xFF && ! bSign) {
                float_raise(status, float_flag_invalid);
                return float32_default_nan;
            }
            return a;
        }
        float_raise(status, float_flag_denormal);
    }

    if ((bExp | bSig) == 0) return a;

    if (bExp == 0xFF) {
        if (bSign) return packFloat32(aSign, 0, 0);
        return packFloat32(aSign, 0xFF, 0);
    }

    if (bExp >= 0x8E) {
        // handle obvious overflow/underflow result
        return roundAndPackFloat32(aSign, bSign ? -0x7F : 0xFF, aSig, status);
    }

    int scale = 0;

    if (bExp <= 0x7E) {
        if (bExp == 0)
            float_raise(status, float_flag_denormal);
        scale = -bSign;
    }
    else {
        int shiftCount = bExp - 0x9E;
        bSig = (bSig | 0x800000)<<8;
        scale = bSig>>(-shiftCount);

        if (bSign) {
            if ((Bit32u) (bSig<<(shiftCount & 31))) scale++;
            scale = -scale;
        }

        if (scale >  0x200) scale =  0x200;
        if (scale < -0x200) scale = -0x200;
    }

    if (aExp != 0) {
        aSig |= 0x00800000;
    } else {
        aExp++;
    }

    aExp += scale - 1;
    aSig <<= 7;
    return normalizeRoundAndPackFloat32(aSign, aExp, aSig, status);
}

/*----------------------------------------------------------------------------
| Returns the result of adding the absolute values of the single-precision
| floating-point values `a' and `b'.  If `zSign' is 1, the sum is negated
| before being returned.  `zSign' is ignored if the result is a NaN.
| The addition is performed according to the IEC/IEEE Standard for Binary
| Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

static float32 addFloat32Sigs(float32 a, float32 b, int zSign, float_status_t &status)
{
    Bit16s aExp, bExp, zExp;
    Bit32u aSig, bSig, zSig;
    Bit16s expDiff;

    aSig = extractFloat32Frac(a);
    aExp = extractFloat32Exp(a);
    bSig = extractFloat32Frac(b);
    bExp = extractFloat32Exp(b);

    if (get_denormals_are_zeros(status)) {
        if (aExp == 0) aSig = 0;
        if (bExp == 0) bSig = 0;
    }

    expDiff = aExp - bExp;
    aSig <<= 6;
    bSig <<= 6;

    if (0 < expDiff) {
        if (aExp == 0xFF) {
            if (aSig) return propagateFloat32NaN(a, b, status);
            if (bSig && (bExp == 0)) float_raise(status, float_flag_denormal);
            return a;
        }
        if ((aExp == 0) && aSig)
            float_raise(status, float_flag_denormal);

        if (bExp == 0) {
            if (bSig) float_raise(status, float_flag_denormal);
            --expDiff;
        }
        else bSig |= 0x20000000;

        bSig = shift32RightJamming(bSig, expDiff);
        zExp = aExp;
    }
    else if (expDiff < 0) {
        if (bExp == 0xFF) {
            if (bSig) return propagateFloat32NaN(a, b, status);
            if (aSig && (aExp == 0)) float_raise(status, float_flag_denormal);
            return packFloat32(zSign, 0xFF, 0);
        }
        if ((bExp == 0) && bSig)
            float_raise(status, float_flag_denormal);

        if (aExp == 0) {
            if (aSig) float_raise(status, float_flag_denormal);
            ++expDiff;
        }
        else aSig |= 0x20000000;

        aSig = shift32RightJamming(aSig, -expDiff);
        zExp = bExp;
    }
    else {
        if (aExp == 0xFF) {
            if (aSig | bSig) return propagateFloat32NaN(a, b, status);
            return a;
        }
        if (aExp == 0) {
            zSig = (aSig + bSig) >> 6;
            if (aSig | bSig) {
                float_raise(status, float_flag_denormal);
                if (get_flush_underflow_to_zero(status) && (extractFloat32Frac(zSig) == zSig)) {
                    float_raise(status, float_flag_underflow | float_flag_inexact);
                    return packFloat32(zSign, 0, 0);
                }
                if (! float_exception_masked(status, float_flag_underflow)) {
                    if (extractFloat32Frac(zSig) == zSig)
                        float_raise(status, float_flag_underflow);
                }
            }
            return packFloat32(zSign, 0, zSig);
        }
        zSig = 0x40000000 + aSig + bSig;
        return roundAndPackFloat32(zSign, aExp, zSig, status);
    }
    aSig |= 0x20000000;
    zSig = (aSig + bSig)<<1;
    --zExp;
    if ((Bit32s) zSig < 0) {
        zSig = aSig + bSig;
        ++zExp;
    }
    return roundAndPackFloat32(zSign, zExp, zSig, status);
}

/*----------------------------------------------------------------------------
| Returns the result of subtracting the absolute values of the single-
| precision floating-point values `a' and `b'.  If `zSign' is 1, the
| difference is negated before being returned.  `zSign' is ignored if the
| result is a NaN.  The subtraction is performed according to the IEC/IEEE
| Standard for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

static float32 subFloat32Sigs(float32 a, float32 b, int zSign, float_status_t &status)
{
    Bit16s aExp, bExp, zExp;
    Bit32u aSig, bSig, zSig;
    Bit16s expDiff;

    aSig = extractFloat32Frac(a);
    aExp = extractFloat32Exp(a);
    bSig = extractFloat32Frac(b);
    bExp = extractFloat32Exp(b);

    if (get_denormals_are_zeros(status)) {
        if (aExp == 0) aSig = 0;
        if (bExp == 0) bSig = 0;
    }

    expDiff = aExp - bExp;
    aSig <<= 7;
    bSig <<= 7;
    if (0 < expDiff) goto aExpBigger;
    if (expDiff < 0) goto bExpBigger;
    if (aExp == 0xFF) {
        if (aSig | bSig) return propagateFloat32NaN(a, b, status);
        float_raise(status, float_flag_invalid);
        return float32_default_nan;
    }
    if (aExp == 0) {
        if (aSig | bSig) float_raise(status, float_flag_denormal);
        aExp = 1;
        bExp = 1;
    }
    if (bSig < aSig) goto aBigger;
    if (aSig < bSig) goto bBigger;
    return packFloat32(get_float_rounding_mode(status) == float_round_down, 0, 0);
 bExpBigger:
    if (bExp == 0xFF) {
        if (bSig) return propagateFloat32NaN(a, b, status);
        if (aSig && (aExp == 0)) float_raise(status, float_flag_denormal);
        return packFloat32(zSign ^ 1, 0xFF, 0);
    }
    if ((bExp == 0) && bSig)
        float_raise(status, float_flag_denormal);

    if (aExp == 0) {
        if (aSig) float_raise(status, float_flag_denormal);
        ++expDiff;
    }
    else aSig |= 0x40000000;

    aSig = shift32RightJamming(aSig, -expDiff);
    bSig |= 0x40000000;
 bBigger:
    zSig = bSig - aSig;
    zExp = bExp;
    zSign ^= 1;
    goto normalizeRoundAndPack;
 aExpBigger:
    if (aExp == 0xFF) {
        if (aSig) return propagateFloat32NaN(a, b, status);
        if (bSig && (bExp == 0)) float_raise(status, float_flag_denormal);
        return a;
    }
    if ((aExp == 0) && aSig)
        float_raise(status, float_flag_denormal);

    if (bExp == 0) {
        if (bSig) float_raise(status, float_flag_denormal);
        --expDiff;
    }
    else bSig |= 0x40000000;

    bSig = shift32RightJamming(bSig, expDiff);
    aSig |= 0x40000000;
 aBigger:
    zSig = aSig - bSig;
    zExp = aExp;
 normalizeRoundAndPack:
    --zExp;
    return normalizeRoundAndPackFloat32(zSign, zExp, zSig, status);
}

/*----------------------------------------------------------------------------
| Returns the result of adding the single-precision floating-point values `a'
| and `b'.  The operation is performed according to the IEC/IEEE Standard for
| Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float32 float32_add(float32 a, float32 b, float_status_t &status)
{
    int aSign = extractFloat32Sign(a);
    int bSign = extractFloat32Sign(b);

    if (aSign == bSign) {
        return addFloat32Sigs(a, b, aSign, status);
    }
    else {
        return subFloat32Sigs(a, b, aSign, status);
    }
}

/*----------------------------------------------------------------------------
| Returns the result of subtracting the single-precision floating-point values
| `a' and `b'.  The operation is performed according to the IEC/IEEE Standard
| for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float32 float32_sub(float32 a, float32 b, float_status_t &status)
{
    int aSign = extractFloat32Sign(a);
    int bSign = extractFloat32Sign(b);

    if (aSign == bSign) {
        return subFloat32Sigs(a, b, aSign, status);
    }
    else {
        return addFloat32Sigs(a, b, aSign, status);
    }
}

/*----------------------------------------------------------------------------
| Returns the result of multiplying the single-precision floating-point values
| `a' and `b'.  The operation is performed according to the IEC/IEEE Standard
| for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float32 float32_mul(float32 a, float32 b, float_status_t &status)
{
    int aSign, bSign, zSign;
    Bit16s aExp, bExp, zExp;
    Bit32u aSig, bSig;
    Bit64u zSig64;
    Bit32u zSig;

    aSig = extractFloat32Frac(a);
    aExp = extractFloat32Exp(a);
    aSign = extractFloat32Sign(a);
    bSig = extractFloat32Frac(b);
    bExp = extractFloat32Exp(b);
    bSign = extractFloat32Sign(b);
    zSign = aSign ^ bSign;

    if (get_denormals_are_zeros(status)) {
        if (aExp == 0) aSig = 0;
        if (bExp == 0) bSig = 0;
    }

    if (aExp == 0xFF) {
        if (aSig || ((bExp == 0xFF) && bSig))
            return propagateFloat32NaN(a, b, status);

        if ((bExp | bSig) == 0) {
            float_raise(status, float_flag_invalid);
            return float32_default_nan;
        }
        if (bSig && (bExp == 0)) float_raise(status, float_flag_denormal);
        return packFloat32(zSign, 0xFF, 0);
    }
    if (bExp == 0xFF) {
        if (bSig) return propagateFloat32NaN(a, b, status);
        if ((aExp | aSig) == 0) {
            float_raise(status, float_flag_invalid);
            return float32_default_nan;
        }
        if (aSig && (aExp == 0)) float_raise(status, float_flag_denormal);
        return packFloat32(zSign, 0xFF, 0);
    }
    if (aExp == 0) {
        if (aSig == 0) {
            if (bSig && (bExp == 0)) float_raise(status, float_flag_denormal);
            return packFloat32(zSign, 0, 0);
        }
        float_raise(status, float_flag_denormal);
        normalizeFloat32Subnormal(aSig, &aExp, &aSig);
    }
    if (bExp == 0) {
        if (bSig == 0) return packFloat32(zSign, 0, 0);
        float_raise(status, float_flag_denormal);
        normalizeFloat32Subnormal(bSig, &bExp, &bSig);
    }
    zExp = aExp + bExp - 0x7F;
    aSig = (aSig | 0x00800000)<<7;
    bSig = (bSig | 0x00800000)<<8;
    zSig64 = shift64RightJamming(((Bit64u) aSig) * bSig, 32);
    zSig = (Bit32u) zSig64;
    if (0 <= (Bit32s) (zSig<<1)) {
        zSig <<= 1;
        --zExp;
    }
    return roundAndPackFloat32(zSign, zExp, zSig, status);
}

/*----------------------------------------------------------------------------
| Returns the result of dividing the single-precision floating-point value `a'
| by the corresponding value `b'.  The operation is performed according to the
| IEC/IEEE Standard for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float32 float32_div(float32 a, float32 b, float_status_t &status)
{
    int aSign, bSign, zSign;
    Bit16s aExp, bExp, zExp;
    Bit32u aSig, bSig, zSig;

    aSig = extractFloat32Frac(a);
    aExp = extractFloat32Exp(a);
    aSign = extractFloat32Sign(a);
    bSig = extractFloat32Frac(b);
    bExp = extractFloat32Exp(b);
    bSign = extractFloat32Sign(b);
    zSign = aSign ^ bSign;

    if (get_denormals_are_zeros(status)) {
        if (aExp == 0) aSig = 0;
        if (bExp == 0) bSig = 0;
    }

    if (aExp == 0xFF) {
        if (aSig) return propagateFloat32NaN(a, b, status);
        if (bExp == 0xFF) {
            if (bSig) return propagateFloat32NaN(a, b, status);
            float_raise(status, float_flag_invalid);
            return float32_default_nan;
        }
        if (bSig && (bExp == 0)) float_raise(status, float_flag_denormal);
        return packFloat32(zSign, 0xFF, 0);
    }
    if (bExp == 0xFF) {
        if (bSig) return propagateFloat32NaN(a, b, status);
        if (aSig && (aExp == 0)) float_raise(status, float_flag_denormal);
        return packFloat32(zSign, 0, 0);
    }
    if (bExp == 0) {
        if (bSig == 0) {
            if ((aExp | aSig) == 0) {
                float_raise(status, float_flag_invalid);
                return float32_default_nan;
            }
            float_raise(status, float_flag_divbyzero);
            return packFloat32(zSign, 0xFF, 0);
        }
        float_raise(status, float_flag_denormal);
        normalizeFloat32Subnormal(bSig, &bExp, &bSig);
    }
    if (aExp == 0) {
        if (aSig == 0) return packFloat32(zSign, 0, 0);
        float_raise(status, float_flag_denormal);
        normalizeFloat32Subnormal(aSig, &aExp, &aSig);
    }
    zExp = aExp - bExp + 0x7D;
    aSig = (aSig | 0x00800000)<<7;
    bSig = (bSig | 0x00800000)<<8;
    if (bSig <= (aSig + aSig)) {
        aSig >>= 1;
        ++zExp;
    }
    zSig = (((Bit64u) aSig)<<32) / bSig;
    if ((zSig & 0x3F) == 0) {
        zSig |= ((Bit64u) bSig * zSig != ((Bit64u) aSig)<<32);
    }
    return roundAndPackFloat32(zSign, zExp, zSig, status);
}

/*----------------------------------------------------------------------------
| Returns the square root of the single-precision floating-point value `a'.
| The operation is performed according to the IEC/IEEE Standard for Binary
| Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float32 float32_sqrt(float32 a, float_status_t &status)
{
    int aSign;
    Bit16s aExp, zExp;
    Bit32u aSig, zSig;
    Bit64u rem, term;

    aSig = extractFloat32Frac(a);
    aExp = extractFloat32Exp(a);
    aSign = extractFloat32Sign(a);

    if (aExp == 0xFF) {
        if (aSig) return propagateFloat32NaN(a, status);
        if (! aSign) return a;
        float_raise(status, float_flag_invalid);
        return float32_default_nan;
    }

    if (get_denormals_are_zeros(status)) {
        if (aExp == 0) aSig = 0;
    }

    if (aSign) {
        if ((aExp | aSig) == 0) return packFloat32(aSign, 0, 0);
        float_raise(status, float_flag_invalid);
        return float32_default_nan;
    }
    if (aExp == 0) {
        if (aSig == 0) return 0;
        float_raise(status, float_flag_denormal);
        normalizeFloat32Subnormal(aSig, &aExp, &aSig);
    }
    zExp = ((aExp - 0x7F)>>1) + 0x7E;
    aSig = (aSig | 0x00800000)<<8;
    zSig = estimateSqrt32(aExp, aSig) + 2;
    if ((zSig & 0x7F) <= 5) {
        if (zSig < 2) {
            zSig = 0x7FFFFFFF;
            goto roundAndPack;
        }
        aSig >>= aExp & 1;
        term = ((Bit64u) zSig) * zSig;
        rem = (((Bit64u) aSig)<<32) - term;
        while ((Bit64s) rem < 0) {
            --zSig;
            rem += (((Bit64u) zSig)<<1) | 1;
        }
        zSig |= (rem != 0);
    }
    zSig = shift32RightJamming(zSig, 1);
 roundAndPack:
    return roundAndPackFloat32(0, zExp, zSig, status);
}

/*----------------------------------------------------------------------------
| Determine single-precision floating-point number class.
*----------------------------------------------------------------------------*/

float_class_t float32_class(float32 a)
{
   Bit16s aExp = extractFloat32Exp(a);
   Bit32u aSig = extractFloat32Frac(a);
   int  aSign = extractFloat32Sign(a);

   if(aExp == 0xFF) {
       if (aSig == 0)
           return (aSign) ? float_negative_inf : float_positive_inf;

       return (aSig & 0x00400000) ? float_QNaN : float_SNaN;
   }

   if(aExp == 0) {
       if (aSig == 0) return float_zero;
       return float_denormal;
   }

   return float_normalized;
}

/*----------------------------------------------------------------------------
| Compare  between  two  single  precision  floating  point  numbers. Returns
| 'float_relation_equal'  if the operands are equal, 'float_relation_less' if
| the    value    'a'   is   less   than   the   corresponding   value   `b',
| 'float_relation_greater' if the value 'a' is greater than the corresponding
| value `b', or 'float_relation_unordered' otherwise.
*----------------------------------------------------------------------------*/

int float32_compare(float32 a, float32 b, int quiet, float_status_t &status)
{
    if (get_denormals_are_zeros(status)) {
        a = float32_denormal_to_zero(a);
        b = float32_denormal_to_zero(b);
    }

    float_class_t aClass = float32_class(a);
    float_class_t bClass = float32_class(b);

    if (aClass == float_SNaN || bClass == float_SNaN) {
        float_raise(status, float_flag_invalid);
        return float_relation_unordered;
    }

    if (aClass == float_QNaN || bClass == float_QNaN) {
        if (! quiet) float_raise(status, float_flag_invalid);
        return float_relation_unordered;
    }

    if (aClass == float_denormal || bClass == float_denormal) {
        float_raise(status, float_flag_denormal);
    }

    if ((a == b) || ((Bit32u) ((a | b)<<1) == 0)) return float_relation_equal;

    int aSign = extractFloat32Sign(a);
    int bSign = extractFloat32Sign(b);
    if (aSign != bSign)
        return (aSign) ? float_relation_less : float_relation_greater;

    if (aSign ^ (a < b)) return float_relation_less;
    return float_relation_greater;
}

/*----------------------------------------------------------------------------
| Compare between two single precision floating point numbers and return the
| smaller of them.
*----------------------------------------------------------------------------*/

float32 float32_min(float32 a, float32 b, float_status_t &status)
{
  if (get_denormals_are_zeros(status)) {
    a = float32_denormal_to_zero(a);
    b = float32_denormal_to_zero(b);
  }

  return (float32_compare(a, b, status) == float_relation_less) ? a : b;
}

/*----------------------------------------------------------------------------
| Compare between two single precision floating point numbers and return the
| larger of them.
*----------------------------------------------------------------------------*/

float32 float32_max(float32 a, float32 b, float_status_t &status)
{
  if (get_denormals_are_zeros(status)) {
    a = float32_denormal_to_zero(a);
    b = float32_denormal_to_zero(b);
  }

  return (float32_compare(a, b, status) == float_relation_greater) ? a : b;
}

/*----------------------------------------------------------------------------
| Compare between two  single precision  floating point numbers and  return the
| smaller/larger of them. The operation  is performed according to the IEC/IEEE
| Standard for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float32 float32_minmax(float32 a, float32 b, int is_max, int is_abs, float_status_t &status)
{
    if (get_denormals_are_zeros(status)) {
        a = float32_denormal_to_zero(a);
        b = float32_denormal_to_zero(b);
    }

    if (float32_is_nan(a) || float32_is_nan(b)) {
        if (float32_is_signaling_nan(a)) {
            return propagateFloat32NaN(a, status);
        }
        if (float32_is_signaling_nan(b) ) {
            return propagateFloat32NaN(b, status);
        }
        if (! float32_is_nan(b)) {
            if (float32_is_denormal(b))
                float_raise(status, float_flag_denormal);
            return b;
        }
        if (! float32_is_nan(a)) {
            if (float32_is_denormal(a))
                float_raise(status, float_flag_denormal);
            return a;
        }
        return propagateFloat32NaN(a, b, status);
    }

    float32 tmp_a = a, tmp_b = b;
    if (is_abs) {
        tmp_a &= ~0x80000000; // clear the sign bit
        tmp_b &= ~0x80000000;
    }

    int aSign = extractFloat32Sign(tmp_a);
    int bSign = extractFloat32Sign(tmp_b);

    if (float32_is_denormal(a) || float32_is_denormal(b))
        float_raise(status, float_flag_denormal);

    if (aSign != bSign) {
        if (! is_max) {
            return aSign ? a : b;
        } else {
            return aSign ? b : a;
        }
    } else {
        if (! is_max) {
            return (aSign ^ (tmp_a < tmp_b)) ? a : b;
        } else {
            return (aSign ^ (tmp_a < tmp_b)) ? b : a;
        }
    }
}

/*----------------------------------------------------------------------------
| Returns the result of converting the double-precision floating-point value
| `a' to the 32-bit two's complement 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 or the
| conversion overflows, the integer indefinite value is returned.
*----------------------------------------------------------------------------*/

Bit32s float64_to_int32(float64 a, float_status_t &status)
{
    Bit64u aSig = extractFloat64Frac(a);
    Bit16s aExp = extractFloat64Exp(a);
    int aSign = extractFloat64Sign(a);
    if ((aExp == 0x7FF) && aSig) aSign = 0;
    if (aExp) aSig |= BX_CONST64(0x0010000000000000);
    else {
        if (get_denormals_are_zeros(status)) aSig = 0;
    }
    int shiftCount = 0x42C - aExp;
    if (0 < shiftCount) aSig = shift64RightJamming(aSig, shiftCount);
    return roundAndPackInt32(aSign, aSig, status);
}

/*----------------------------------------------------------------------------
| Returns the result of converting the double-precision floating-point value
| `a' to the 32-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 `a' is a NaN or the conversion overflows, the integer indefinite
| value  is returned.
*----------------------------------------------------------------------------*/

Bit32s float64_to_int32_round_to_zero(float64 a, float_status_t &status)
{
    int aSign;
    Bit16s aExp;
    Bit64u aSig, savedASig;
    Bit32s z;
    int shiftCount;

    aSig = extractFloat64Frac(a);
    aExp = extractFloat64Exp(a);
    aSign = extractFloat64Sign(a);
    if (0x41E < aExp) {
        float_raise(status, float_flag_invalid);
        return (Bit32s)(int32_indefinite);
    }
    else if (aExp < 0x3FF) {
        if (get_denormals_are_zeros(status) && aExp == 0) aSig = 0;
        if (aExp || aSig) float_raise(status, float_flag_inexact);
        return 0;
    }
    aSig |= BX_CONST64(0x0010000000000000);
    shiftCount = 0x433 - aExp;
    savedASig = aSig;
    aSig >>= shiftCount;
    z = (Bit32s) aSig;
    if (aSign) z = -z;
    if ((z < 0) ^ aSign) {
        float_raise(status, float_flag_invalid);
        return (Bit32s)(int32_indefinite);
    }
    if ((aSig<<shiftCount) != savedASig) {
        float_raise(status, float_flag_inexact);
    }
    return z;
}

/*----------------------------------------------------------------------------
| Returns the result of converting the double-precision floating-point value
| `a' to the 32-bit unsigned 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 `a' is a NaN
| or conversion overflows, the largest positive integer is returned.
*----------------------------------------------------------------------------*/

Bit32u float64_to_uint32_round_to_zero(float64 a, float_status_t &status)
{
    Bit64u aSig = extractFloat64Frac(a);
    Bit16s aExp = extractFloat64Exp(a);
    int aSign = extractFloat64Sign(a);

    if (aExp < 0x3FF) {
        if (get_denormals_are_zeros(status) && aExp == 0) aSig = 0;
        if (aExp || aSig) float_raise(status, float_flag_inexact);
        return 0;
    }

    if (0x41E < aExp || aSign) {
        float_raise(status, float_flag_invalid);
        return uint32_indefinite;
    }

    aSig |= BX_CONST64(0x0010000000000000);
    int shiftCount = 0x433 - aExp;
    Bit64u savedASig = aSig;
    aSig >>= shiftCount;
    if ((aSig<<shiftCount) != savedASig) {
        float_raise(status, float_flag_inexact);
    }
    return (Bit32u) aSig;
}

/*----------------------------------------------------------------------------
| Returns the result of converting the double-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 - which means in particular that the conversion is rounded
| according to the current rounding mode.  If `a' is a NaN, the largest
| positive integer is returned.  Otherwise, if the conversion overflows, the
| largest integer with the same sign as `a' is returned.
*----------------------------------------------------------------------------*/

Bit64s float64_to_int64(float64 a, float_status_t &status)
{
    int aSign;
    Bit16s aExp;
    Bit64u aSig, aSigExtra;

    aSig = extractFloat64Frac(a);
    aExp = extractFloat64Exp(a);
    aSign = extractFloat64Sign(a);
    if (aExp) aSig |= BX_CONST64(0x0010000000000000);
    else {
        if (get_denormals_are_zeros(status)) aSig = 0;
    }
    int shiftCount = 0x433 - aExp;
    if (shiftCount <= 0) {
        if (0x43E < aExp) {
            float_raise(status, float_flag_invalid);
            return (Bit64s)(int64_indefinite);
        }
        aSigExtra = 0;
        aSig <<= -shiftCount;
    }
    else {
        shift64ExtraRightJamming(aSig, 0, shiftCount, &aSig, &aSigExtra);
    }
    return roundAndPackInt64(aSign, aSig, aSigExtra, status);
}

/*----------------------------------------------------------------------------
| Returns the result of converting the double-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 `a' is a NaN or the conversion overflows, the integer indefinite
| value  is returned.
*----------------------------------------------------------------------------*/

Bit64s float64_to_int64_round_to_zero(float64 a, float_status_t &status)
{
    int aSign;
    Bit16s aExp;
    Bit64u aSig;
    Bit64s z;

    aSig = extractFloat64Frac(a);
    aExp = extractFloat64Exp(a);
    aSign = extractFloat64Sign(a);
    if (aExp) aSig |= BX_CONST64(0x0010000000000000);
    int shiftCount = aExp - 0x433;
    if (0 <= shiftCount) {
        if (0x43E <= aExp) {
            if (a != BX_CONST64(0xC3E0000000000000)) {
                float_raise(status, float_flag_invalid);
            }
            return (Bit64s)(int64_indefinite);
        }
        z = aSig<<shiftCount;
    }
    else {
        if (aExp < 0x3FE) {
            if (get_denormals_are_zeros(status) && aExp == 0) aSig = 0;
            if (aExp | aSig) float_raise(status, float_flag_inexact);
            return 0;
        }
        z = aSig>>(-shiftCount);
        if ((Bit64u) (aSig<<(shiftCount & 63))) {
             float_raise(status, float_flag_inexact);
        }
    }
    if (aSign) z = -z;
    return z;
}

/*----------------------------------------------------------------------------
| Returns the result of converting the double-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,
| except that the conversion is always rounded toward zero. If `a' is a NaN
| or the conversion overflows, the largest unsigned integer is returned.
*----------------------------------------------------------------------------*/

Bit64u float64_to_uint64_round_to_zero(float64 a, float_status_t &status)
{
    int aSign;
    Bit16s aExp;
    Bit64u aSig, z;

    aSig = extractFloat64Frac(a);
    aExp = extractFloat64Exp(a);
    aSign = extractFloat64Sign(a);

    if (aExp < 0x3FE) {
        if (get_denormals_are_zeros(status) && aExp == 0) aSig = 0;
        if (aExp | aSig) float_raise(status, float_flag_inexact);
        return 0;
    }

    if (0x43E <= aExp || aSign) {
        float_raise(status, float_flag_invalid);
        return uint64_indefinite;
    }

    if (aExp) aSig |= BX_CONST64(0x0010000000000000);
    int shiftCount = aExp - 0x433;

    if (0 <= shiftCount) {
        z = aSig<<shiftCount;
    }
    else {
        z = aSig>>(-shiftCount);
        if ((Bit64u) (aSig<<(shiftCount & 63))) {
             float_raise(status, float_flag_inexact);
        }
    }
    return z;
}

/*----------------------------------------------------------------------------
| Returns the result of converting the double-precision floating-point value
| `a' to the 32-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 or the conversion
| overflows, the largest unsigned integer is returned.
*----------------------------------------------------------------------------*/

Bit32u float64_to_uint32(float64 a, float_status_t &status)
{
    Bit64u val_64 = float64_to_uint64(a, status);

    if (val_64 > 0xffffffff) {
        status.float_exception_flags = float_flag_invalid; // throw away other flags
        return uint32_indefinite;
    }

    return (Bit32u) val_64;
}

/*----------------------------------------------------------------------------
| Returns the result of converting the double-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 or the conversion
| overflows, the largest unsigned integer is returned.
*----------------------------------------------------------------------------*/
 
Bit64u float64_to_uint64(float64 a, float_status_t &status)
{
    int aSign;
    Bit16s aExp, shiftCount;
    Bit64u aSig, aSigExtra;
 
    aSig = extractFloat64Frac(a);
    aExp = extractFloat64Exp(a);
    aSign = extractFloat64Sign(a);

    if (get_denormals_are_zeros(status)) {
        if (aExp == 0) aSig = 0;
    }

    if (aSign && (aExp > 0x3FE)) {
        float_raise(status, float_flag_invalid);
        return uint64_indefinite;
    }

    if (aExp) {
        aSig |= BX_CONST64(0x0010000000000000);
    }
    shiftCount = 0x433 - aExp;
    if (shiftCount <= 0) {
        if (0x43E < aExp) {
            float_raise(status, float_flag_invalid);
            return uint64_indefinite;
        }
        aSigExtra = 0;
        aSig <<= -shiftCount;
    } else {
        shift64ExtraRightJamming(aSig, 0, shiftCount, &aSig, &aSigExtra);
    }

    return roundAndPackUint64(aSign, aSig, aSigExtra, status);
}

/*----------------------------------------------------------------------------
| Returns the result of converting the double-precision floating-point value
| `a' to the single-precision floating-point format.  The conversion is
| performed according to the IEC/IEEE Standard for Binary Floating-Point
| Arithmetic.
*----------------------------------------------------------------------------*/

float32 float64_to_float32(float64 a, float_status_t &status)
{
    int aSign;
    Bit16s aExp;
    Bit64u aSig;
    Bit32u zSig;

    aSig = extractFloat64Frac(a);
    aExp = extractFloat64Exp(a);
    aSign = extractFloat64Sign(a);
    if (aExp == 0x7FF) {
        if (aSig) return commonNaNToFloat32(float64ToCommonNaN(a, status));
        return packFloat32(aSign, 0xFF, 0);
    }
    if (aExp == 0) {
        if (aSig == 0 || get_denormals_are_zeros(status))
            return packFloat32(aSign, 0, 0);
        float_raise(status, float_flag_denormal);
    }
    aSig = shift64RightJamming(aSig, 22);
    zSig = (Bit32u) aSig;
    if (aExp || zSig) {
        zSig |= 0x40000000;
        aExp -= 0x381;
    }
    return roundAndPackFloat32(aSign, aExp, zSig, status);
}

/*----------------------------------------------------------------------------
| Rounds the double-precision floating-point value `a' to an integer, and
| returns the result as a double-precision floating-point value.  The
| operation is performed according to the IEC/IEEE Standard for Binary
| Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float64 float64_round_to_int(float64 a, Bit8u scale, float_status_t &status)
{
    Bit64u lastBitMask, roundBitsMask;
    int roundingMode = get_float_rounding_mode(status);
    Bit16s aExp = extractFloat64Exp(a);
    scale &= 0xf;

    if ((aExp == 0x7FF) && extractFloat64Frac(a)) {
        return propagateFloat64NaN(a, status);
    }

    aExp += scale; // scale the exponent

    if (0x433 <= aExp) {
        return a;
    }

    if (get_denormals_are_zeros(status)) {
        a = float64_denormal_to_zero(a);
    }

    if (aExp < 0x3FF) {
        if ((Bit64u) (a<<1) == 0) return a;
        float_raise(status, float_flag_inexact);
        int aSign = extractFloat64Sign(a);
        switch (roundingMode) {
         case float_round_nearest_even:
            if ((aExp == 0x3FE) && extractFloat64Frac(a)) {
              return packFloat64(aSign, 0x3FF - scale, 0);
            }
            break;
         case float_round_down:
            return aSign ? packFloat64(1, 0x3FF - scale, 0) : float64_positive_zero;
         case float_round_up:
            return aSign ? float64_negative_zero : packFloat64(0, 0x3FF - scale, 0);
        }
        return packFloat64(aSign, 0, 0);
    }

    lastBitMask = 1;
    lastBitMask <<= 0x433 - aExp;
    roundBitsMask = lastBitMask - 1;
    float64 z = a;
    if (roundingMode == float_round_nearest_even) {
        z += lastBitMask>>1;
        if ((z & roundBitsMask) == 0) z &= ~lastBitMask;
    }
    else if (roundingMode != float_round_to_zero) {
        if (extractFloat64Sign(z) ^ (roundingMode == float_round_up)) {
            z += roundBitsMask;
        }
    }
    z &= ~roundBitsMask;
    if (z != a) float_raise(status, float_flag_inexact);
    return z;
}

/*----------------------------------------------------------------------------
| Extracts the fractional portion of double-precision floating-point value `a',
| and returns the result  as a  double-precision  floating-point value. The
| fractional results are precise. The operation is performed according to the
| IEC/IEEE Standard for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float64 float64_frc(float64 a, float_status_t &status)
{
    int roundingMode = get_float_rounding_mode(status);

    Bit64u aSig = extractFloat64Frac(a);
    Bit16s aExp = extractFloat64Exp(a);
    int aSign = extractFloat64Sign(a);

    if (aExp == 0x7FF) {
        if (aSig) return propagateFloat64NaN(a, status);
        float_raise(status, float_flag_invalid);
        return float64_default_nan;
    }

    if (aExp >= 0x433) {
        return packFloat64(roundingMode == float_round_down, 0, 0);
    }

    if (aExp < 0x3FF) {
        if (aExp == 0) {
            if (aSig == 0 || get_denormals_are_zeros(status))
                return packFloat64(roundingMode == float_round_down, 0, 0);

            float_raise(status, float_flag_denormal);
            if (! float_exception_masked(status, float_flag_underflow))
                float_raise(status, float_flag_underflow);

            if(get_flush_underflow_to_zero(status)) {
                float_raise(status, float_flag_underflow | float_flag_inexact);
                return packFloat64(aSign, 0, 0);
            }
        }
        return a;
    }

    Bit64u lastBitMask = BX_CONST64(1) << (0x433 - aExp);
    Bit64u roundBitsMask = lastBitMask - 1;

    aSig &= roundBitsMask;
    aSig <<= 10;
    aExp--;

    if (aSig == 0)
       return packFloat64(roundingMode == float_round_down, 0, 0);

    return normalizeRoundAndPackFloat64(aSign, aExp, aSig, status);
}

/*----------------------------------------------------------------------------
| Extracts the exponent portion of double-precision floating-point value 'a',
| and returns the result as a double-precision floating-point value
| representing unbiased integer exponent. The operation is performed according
| to the IEC/IEEE Standard for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float64 float64_getexp(float64 a, float_status_t &status)
{
    Bit16s aExp = extractFloat64Exp(a);
    Bit64u aSig = extractFloat64Frac(a);

    if (aExp == 0x7FF) {
        if (aSig) return propagateFloat64NaN(a, status);
        return float64_positive_inf;
    }

    if (aExp == 0) {
        if (aSig == 0 || get_denormals_are_zeros(status))
            return float64_negative_inf;

        float_raise(status, float_flag_denormal);
        normalizeFloat64Subnormal(aSig, &aExp, &aSig);
    }

    return int32_to_float64(aExp - 0x3FF);
}

/*----------------------------------------------------------------------------
| Extracts the mantissa of double-precision floating-point value 'a' and
| returns the result as a double-precision floating-point after applying
| the mantissa interval normalization and sign control. The operation is
| performed according to the IEC/IEEE Standard for Binary Floating-Point
| Arithmetic.
*----------------------------------------------------------------------------*/

float64 float64_getmant(float64 a, float_status_t &status, int sign_ctrl, int interv)
{
    Bit16s aExp = extractFloat64Exp(a);
    Bit64u aSig = extractFloat64Frac(a);
    int aSign = extractFloat64Sign(a);

    if (aExp == 0x7FF) {
        if (aSig) return propagateFloat64NaN(a, status);
        if (aSign) {
            if (sign_ctrl & 0x2) {
                float_raise(status, float_flag_invalid);
                return float64_default_nan;
            }
        }
        return packFloat64(~sign_ctrl & aSign, 0x3FF, 0);
    }

    if (aExp == 0 && (aSig == 0 || get_denormals_are_zeros(status))) {
        return packFloat64(~sign_ctrl & aSign, 0x3FF, 0);
    }

    if (aSign) {
        if (sign_ctrl & 0x2) {
            float_raise(status, float_flag_invalid);
            return float64_default_nan;
        }
    }

    if (aExp == 0) {
        float_raise(status, float_flag_denormal);
        normalizeFloat64Subnormal(aSig, &aExp, &aSig);
//      aExp += 0x3FE;
        aSig &= BX_CONST64(0xFFFFFFFFFFFFFFFF);
    }

    switch(interv) {
    case 0x0: // interval [1,2)
        aExp = 0x3FF;
        break;
    case 0x1: // interval [1/2,2)
        aExp -= 0x3FF;
        aExp  = 0x3FF - (aExp & 0x1);
        break;
    case 0x2: // interval [1/2,1)
        aExp = 0x3FE;
        break;
    case 0x3: // interval [3/4,3/2)
        aExp = 0x3FF - ((aSig >> 51) & 0x1);
        break;
    }

    return packFloat64(~sign_ctrl & aSign, aExp, aSig);
}

/*----------------------------------------------------------------------------
| Return the result of a floating point scale of the double-precision floating
| point value `a' by multiplying it by 2 power of the double-precision
| floating point value 'b' converted to integral value. If the result cannot
| be represented in double precision, then the proper overflow response (for
| positive scaling operand), or the proper underflow response (for negative
| scaling operand) is issued. The operation is performed according to the
| IEC/IEEE Standard for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float64 float64_scalef(float64 a, float64 b, float_status_t &status)
{
    Bit64u aSig = extractFloat64Frac(a);
    Bit16s aExp = extractFloat64Exp(a);
    int aSign = extractFloat64Sign(a);
    Bit64u bSig = extractFloat64Frac(b);
    Bit16s bExp = extractFloat64Exp(b);
    int bSign = extractFloat64Sign(b);

    if (get_denormals_are_zeros(status)) {
        if (aExp == 0) aSig = 0;
        if (bExp == 0) bSig = 0;
    }

    if (bExp == 0x7FF) {
        if (bSig) return propagateFloat64NaN(a, b, status);
    }

    if (aExp == 0x7FF) {
        if (aSig) {
            int aIsSignalingNaN = (aSig & BX_CONST64(0x0008000000000000)) == 0;
            if (aIsSignalingNaN || bExp != 0x7FF || bSig)
                return propagateFloat64NaN(a, b, status);

            return bSign ? 0 : float64_positive_inf;
        }

        if (bExp == 0x7FF && bSign) {
            float_raise(status, float_flag_invalid);
            return float64_default_nan;
        }
        return a;
    }

    if (aExp == 0) {
        if (aSig == 0) {
            if (bExp == 0x7FF && ! bSign) {
                float_raise(status, float_flag_invalid);
                return float64_default_nan;
            }
            return a;
        }
        float_raise(status, float_flag_denormal);
    }

    if ((bExp | bSig) == 0) return a;

    if (bExp == 0x7FF) {
        if (bSign) return packFloat64(aSign, 0, 0);
        return packFloat64(aSign, 0x7FF, 0);
    }

    if (0x40F <= bExp) {
        // handle obvious overflow/underflow result
        return roundAndPackFloat64(aSign, bSign ? -0x3FF : 0x7FF, aSig, status);
    }

    int scale = 0;

    if (bExp < 0x3FF) {
        if (bExp == 0)
            float_raise(status, float_flag_denormal);
        scale = -bSign;
    }
    else {
        bSig |= BX_CONST64(0x0010000000000000);
        int shiftCount = 0x433 - bExp;
        Bit64u savedBSig = bSig;
        bSig >>= shiftCount;
        scale = (Bit32s) bSig;
        if (bSign) {
            if ((bSig<<shiftCount) != savedBSig) scale++;
            scale = -scale;
        }

        if (scale >  0x1000) scale =  0x1000;
        if (scale < -0x1000) scale = -0x1000;
    }

    if (aExp != 0) {
        aSig |= BX_CONST64(0x0010000000000000);
    } else {
        aExp++;
    }

    aExp += scale - 1;
    aSig <<= 10;
    return normalizeRoundAndPackFloat64(aSign, aExp, aSig, status);
}

/*----------------------------------------------------------------------------
| Returns the result of adding the absolute values of the double-precision
| floating-point values `a' and `b'.  If `zSign' is 1, the sum is negated
| before being returned.  `zSign' is ignored if the result is a NaN.
| The addition is performed according to the IEC/IEEE Standard for Binary
| Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

static float64 addFloat64Sigs(float64 a, float64 b, int zSign, float_status_t &status)
{
    Bit16s aExp, bExp, zExp;
    Bit64u aSig, bSig, zSig;
    Bit16s expDiff;

    aSig = extractFloat64Frac(a);
    aExp = extractFloat64Exp(a);
    bSig = extractFloat64Frac(b);
    bExp = extractFloat64Exp(b);

    if (get_denormals_are_zeros(status)) {
        if (aExp == 0) aSig = 0;
        if (bExp == 0) bSig = 0;
    }

    expDiff = aExp - bExp;
    aSig <<= 9;
    bSig <<= 9;
    if (0 < expDiff) {
        if (aExp == 0x7FF) {
            if (aSig) return propagateFloat64NaN(a, b, status);
            if (bSig && (bExp == 0)) float_raise(status, float_flag_denormal);
            return a;
        }
        if ((aExp == 0) && aSig)
            float_raise(status, float_flag_denormal);

        if (bExp == 0) {
            if (bSig) float_raise(status, float_flag_denormal);
            --expDiff;
        }
        else bSig |= BX_CONST64(0x2000000000000000);

        bSig = shift64RightJamming(bSig, expDiff);
        zExp = aExp;
    }
    else if (expDiff < 0) {
        if (bExp == 0x7FF) {
            if (bSig) return propagateFloat64NaN(a, b, status);
            if (aSig && (aExp == 0)) float_raise(status, float_flag_denormal);
            return packFloat64(zSign, 0x7FF, 0);
        }
        if ((bExp == 0) && bSig)
            float_raise(status, float_flag_denormal);

        if (aExp == 0) {
            if (aSig) float_raise(status, float_flag_denormal);
            ++expDiff;
        }
        else aSig |= BX_CONST64(0x2000000000000000);

        aSig = shift64RightJamming(aSig, -expDiff);
        zExp = bExp;
    }
    else {
        if (aExp == 0x7FF) {
            if (aSig | bSig) return propagateFloat64NaN(a, b, status);
            return a;
        }
        if (aExp == 0) {
            zSig = (aSig + bSig) >> 9;
            if (aSig | bSig) {
                float_raise(status, float_flag_denormal);
                if (get_flush_underflow_to_zero(status) && (extractFloat64Frac(zSig) == zSig)) {
                    float_raise(status, float_flag_underflow | float_flag_inexact);
                    return packFloat64(zSign, 0, 0);
                }
                if (! float_exception_masked(status, float_flag_underflow)) {
                    if (extractFloat64Frac(zSig) == zSig)
                        float_raise(status, float_flag_underflow);
                }
            }
            return packFloat64(zSign, 0, zSig);
        }
        zSig = BX_CONST64(0x4000000000000000) + aSig + bSig;
        return roundAndPackFloat64(zSign, aExp, zSig, status);
    }
    aSig |= BX_CONST64(0x2000000000000000);
    zSig = (aSig + bSig)<<1;
    --zExp;
    if ((Bit64s) zSig < 0) {
        zSig = aSig + bSig;
        ++zExp;
    }
    return roundAndPackFloat64(zSign, zExp, zSig, status);
}

/*----------------------------------------------------------------------------
| Returns the result of subtracting the absolute values of the double-
| precision floating-point values `a' and `b'.  If `zSign' is 1, the
| difference is negated before being returned.  `zSign' is ignored if the
| result is a NaN.  The subtraction is performed according to the IEC/IEEE
| Standard for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

static float64 subFloat64Sigs(float64 a, float64 b, int zSign, float_status_t &status)
{
    Bit16s aExp, bExp, zExp;
    Bit64u aSig, bSig, zSig;
    Bit16s expDiff;

    aSig = extractFloat64Frac(a);
    aExp = extractFloat64Exp(a);
    bSig = extractFloat64Frac(b);
    bExp = extractFloat64Exp(b);

    if (get_denormals_are_zeros(status)) {
        if (aExp == 0) aSig = 0;
        if (bExp == 0) bSig = 0;
    }

    expDiff = aExp - bExp;
    aSig <<= 10;
    bSig <<= 10;
    if (0 < expDiff) goto aExpBigger;
    if (expDiff < 0) goto bExpBigger;
    if (aExp == 0x7FF) {
        if (aSig | bSig) return propagateFloat64NaN(a, b, status);
        float_raise(status, float_flag_invalid);
        return float64_default_nan;
    }
    if (aExp == 0) {
        if (aSig | bSig) float_raise(status, float_flag_denormal);
        aExp = 1;
        bExp = 1;
    }
    if (bSig < aSig) goto aBigger;
    if (aSig < bSig) goto bBigger;
    return packFloat64(get_float_rounding_mode(status) == float_round_down, 0, 0);
 bExpBigger:
    if (bExp == 0x7FF) {
        if (bSig) return propagateFloat64NaN(a, b, status);
        if (aSig && (aExp == 0)) float_raise(status, float_flag_denormal);
        return packFloat64(zSign ^ 1, 0x7FF, 0);
    }
    if ((bExp == 0) && bSig)
        float_raise(status, float_flag_denormal);

    if (aExp == 0) {
        if (aSig) float_raise(status, float_flag_denormal);
        ++expDiff;
    }
    else aSig |= BX_CONST64(0x4000000000000000);

    aSig = shift64RightJamming(aSig, -expDiff);
    bSig |= BX_CONST64(0x4000000000000000);
 bBigger:
    zSig = bSig - aSig;
    zExp = bExp;
    zSign ^= 1;
    goto normalizeRoundAndPack;
 aExpBigger:
    if (aExp == 0x7FF) {
        if (aSig) return propagateFloat64NaN(a, b, status);
        if (bSig && (bExp == 0)) float_raise(status, float_flag_denormal);
        return a;
    }
    if ((aExp == 0) && aSig)
        float_raise(status, float_flag_denormal);

    if (bExp == 0) {
        if (bSig) float_raise(status, float_flag_denormal);
        --expDiff;
    }
    else bSig |= BX_CONST64(0x4000000000000000);

    bSig = shift64RightJamming(bSig, expDiff);
    aSig |= BX_CONST64(0x4000000000000000);
 aBigger:
    zSig = aSig - bSig;
    zExp = aExp;
 normalizeRoundAndPack:
    --zExp;
    return normalizeRoundAndPackFloat64(zSign, zExp, zSig, status);
}

/*----------------------------------------------------------------------------
| Returns the result of adding the double-precision floating-point values `a'
| and `b'.  The operation is performed according to the IEC/IEEE Standard for
| Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float64 float64_add(float64 a, float64 b, float_status_t &status)
{
    int aSign = extractFloat64Sign(a);
    int bSign = extractFloat64Sign(b);

    if (aSign == bSign) {
        return addFloat64Sigs(a, b, aSign, status);
    }
    else {
        return subFloat64Sigs(a, b, aSign, status);
    }
}

/*----------------------------------------------------------------------------
| Returns the result of subtracting the double-precision floating-point values
| `a' and `b'.  The operation is performed according to the IEC/IEEE Standard
| for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float64 float64_sub(float64 a, float64 b, float_status_t &status)
{
    int aSign = extractFloat64Sign(a);
    int bSign = extractFloat64Sign(b);

    if (aSign == bSign) {
        return subFloat64Sigs(a, b, aSign, status);
    }
    else {
        return addFloat64Sigs(a, b, aSign, status);
    }
}

/*----------------------------------------------------------------------------
| Returns the result of multiplying the double-precision floating-point values
| `a' and `b'.  The operation is performed according to the IEC/IEEE Standard
| for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float64 float64_mul(float64 a, float64 b, float_status_t &status)
{
    int aSign, bSign, zSign;
    Bit16s aExp, bExp, zExp;
    Bit64u aSig, bSig, zSig0, zSig1;

    aSig = extractFloat64Frac(a);
    aExp = extractFloat64Exp(a);
    aSign = extractFloat64Sign(a);
    bSig = extractFloat64Frac(b);
    bExp = extractFloat64Exp(b);
    bSign = extractFloat64Sign(b);
    zSign = aSign ^ bSign;

    if (get_denormals_are_zeros(status)) {
        if (aExp == 0) aSig = 0;
        if (bExp == 0) bSig = 0;
    }

    if (aExp == 0x7FF) {
        if (aSig || ((bExp == 0x7FF) && bSig)) {
            return propagateFloat64NaN(a, b, status);
        }
        if ((bExp | bSig) == 0) {
            float_raise(status, float_flag_invalid);
            return float64_default_nan;
        }
        if (bSig && (bExp == 0)) float_raise(status, float_flag_denormal);
        return packFloat64(zSign, 0x7FF, 0);
    }
    if (bExp == 0x7FF) {
        if (bSig) return propagateFloat64NaN(a, b, status);
        if ((aExp | aSig) == 0) {
            float_raise(status, float_flag_invalid);
            return float64_default_nan;
        }
        if (aSig && (aExp == 0)) float_raise(status, float_flag_denormal);
        return packFloat64(zSign, 0x7FF, 0);
    }
    if (aExp == 0) {
        if (aSig == 0) {
            if (bSig && (bExp == 0)) float_raise(status, float_flag_denormal);
            return packFloat64(zSign, 0, 0);
        }
        float_raise(status, float_flag_denormal);
        normalizeFloat64Subnormal(aSig, &aExp, &aSig);
    }
    if (bExp == 0) {
        if (bSig == 0) return packFloat64(zSign, 0, 0);
        float_raise(status, float_flag_denormal);
        normalizeFloat64Subnormal(bSig, &bExp, &bSig);
    }
    zExp = aExp + bExp - 0x3FF;
    aSig = (aSig | BX_CONST64(0x0010000000000000))<<10;
    bSig = (bSig | BX_CONST64(0x0010000000000000))<<11;
    mul64To128(aSig, bSig, &zSig0, &zSig1);
    zSig0 |= (zSig1 != 0);
    if (0 <= (Bit64s) (zSig0<<1)) {
        zSig0 <<= 1;
        --zExp;
    }
    return roundAndPackFloat64(zSign, zExp, zSig0, status);
}

/*----------------------------------------------------------------------------
| Returns the result of dividing the double-precision floating-point value `a'
| by the corresponding value `b'.  The operation is performed according to
| the IEC/IEEE Standard for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float64 float64_div(float64 a, float64 b, float_status_t &status)
{
    int aSign, bSign, zSign;
    Bit16s aExp, bExp, zExp;
    Bit64u aSig, bSig, zSig;
    Bit64u rem0, rem1;
    Bit64u term0, term1;

    aSig = extractFloat64Frac(a);
    aExp = extractFloat64Exp(a);
    aSign = extractFloat64Sign(a);
    bSig = extractFloat64Frac(b);
    bExp = extractFloat64Exp(b);
    bSign = extractFloat64Sign(b);
    zSign = aSign ^ bSign;

    if (get_denormals_are_zeros(status)) {
        if (aExp == 0) aSig = 0;
        if (bExp == 0) bSig = 0;
    }

    if (aExp == 0x7FF) {
        if (aSig) return propagateFloat64NaN(a, b, status);
        if (bExp == 0x7FF) {
            if (bSig) return propagateFloat64NaN(a, b, status);
            float_raise(status, float_flag_invalid);
            return float64_default_nan;
        }
        if (bSig && (bExp == 0)) float_raise(status, float_flag_denormal);
        return packFloat64(zSign, 0x7FF, 0);
    }
    if (bExp == 0x7FF) {
        if (bSig) return propagateFloat64NaN(a, b, status);
        if (aSig && (aExp == 0)) float_raise(status, float_flag_denormal);
        return packFloat64(zSign, 0, 0);
    }
    if (bExp == 0) {
        if (bSig == 0) {
            if ((aExp | aSig) == 0) {
                float_raise(status, float_flag_invalid);
                return float64_default_nan;
            }
            float_raise(status, float_flag_divbyzero);
            return packFloat64(zSign, 0x7FF, 0);
        }
        float_raise(status, float_flag_denormal);
        normalizeFloat64Subnormal(bSig, &bExp, &bSig);
    }
    if (aExp == 0) {
        if (aSig == 0) return packFloat64(zSign, 0, 0);
        float_raise(status, float_flag_denormal);
        normalizeFloat64Subnormal(aSig, &aExp, &aSig);
    }
    zExp = aExp - bExp + 0x3FD;
    aSig = (aSig | BX_CONST64(0x0010000000000000))<<10;
    bSig = (bSig | BX_CONST64(0x0010000000000000))<<11;
    if (bSig <= (aSig + aSig)) {
        aSig >>= 1;
        ++zExp;
    }
    zSig = estimateDiv128To64(aSig, 0, bSig);
    if ((zSig & 0x1FF) <= 2) {
        mul64To128(bSig, zSig, &term0, &term1);
        sub128(aSig, 0, term0, term1, &rem0, &rem1);
        while ((Bit64s) rem0 < 0) {
            --zSig;
            add128(rem0, rem1, 0, bSig, &rem0, &rem1);
        }
        zSig |= (rem1 != 0);
    }
    return roundAndPackFloat64(zSign, zExp, zSig, status);
}

/*----------------------------------------------------------------------------
| Returns the square root of the double-precision floating-point value `a'.
| The operation is performed according to the IEC/IEEE Standard for Binary
| Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float64 float64_sqrt(float64 a, float_status_t &status)
{
    int aSign;
    Bit16s aExp, zExp;
    Bit64u aSig, zSig, doubleZSig;
    Bit64u rem0, rem1, term0, term1;

    aSig = extractFloat64Frac(a);
    aExp = extractFloat64Exp(a);
    aSign = extractFloat64Sign(a);

    if (aExp == 0x7FF) {
        if (aSig) return propagateFloat64NaN(a, status);
        if (! aSign) return a;
        float_raise(status, float_flag_invalid);
        return float64_default_nan;
    }

    if (get_denormals_are_zeros(status)) {
        if (aExp == 0) aSig = 0;
    }

    if (aSign) {
        if ((aExp | aSig) == 0) return packFloat64(aSign, 0, 0);
        float_raise(status, float_flag_invalid);
        return float64_default_nan;
    }
    if (aExp == 0) {
        if (aSig == 0) return 0;
        float_raise(status, float_flag_denormal);
        normalizeFloat64Subnormal(aSig, &aExp, &aSig);
    }
    zExp = ((aExp - 0x3FF)>>1) + 0x3FE;
    aSig |= BX_CONST64(0x0010000000000000);
    zSig = estimateSqrt32(aExp, (Bit32u)(aSig>>21));
    aSig <<= 9 - (aExp & 1);
    zSig = estimateDiv128To64(aSig, 0, zSig<<32) + (zSig<<30);
    if ((zSig & 0x1FF) <= 5) {
        doubleZSig = zSig<<1;
        mul64To128(zSig, zSig, &term0, &term1);
        sub128(aSig, 0, term0, term1, &rem0, &rem1);
        while ((Bit64s) rem0 < 0) {
            --zSig;
            doubleZSig -= 2;
            add128(rem0, rem1, zSig>>63, doubleZSig | 1, &rem0, &rem1);
        }
        zSig |= ((rem0 | rem1) != 0);
    }
    return roundAndPackFloat64(0, zExp, zSig, status);
}

/*----------------------------------------------------------------------------
| Determine double-precision floating-point number class
*----------------------------------------------------------------------------*/

float_class_t float64_class(float64 a)
{
   Bit16s aExp = extractFloat64Exp(a);
   Bit64u aSig = extractFloat64Frac(a);
   int  aSign = extractFloat64Sign(a);

   if(aExp == 0x7FF) {
       if (aSig == 0)
           return (aSign) ? float_negative_inf : float_positive_inf;

       return (aSig & BX_CONST64(0x0008000000000000)) ? float_QNaN : float_SNaN;
   }

   if(aExp == 0) {
       if (aSig == 0)
           return float_zero;
       return float_denormal;
   }

   return float_normalized;
}

/*----------------------------------------------------------------------------
| Compare  between  two  double  precision  floating  point  numbers. Returns
| 'float_relation_equal'  if the operands are equal, 'float_relation_less' if
| the    value    'a'   is   less   than   the   corresponding   value   `b',
| 'float_relation_greater' if the value 'a' is greater than the corresponding
| value `b', or 'float_relation_unordered' otherwise.
*----------------------------------------------------------------------------*/

int float64_compare(float64 a, float64 b, int quiet, float_status_t &status)
{
    if (get_denormals_are_zeros(status)) {
        a = float64_denormal_to_zero(a);
        b = float64_denormal_to_zero(b);
    }

    float_class_t aClass = float64_class(a);
    float_class_t bClass = float64_class(b);

    if (aClass == float_SNaN || bClass == float_SNaN) {
        float_raise(status, float_flag_invalid);
        return float_relation_unordered;
    }

    if (aClass == float_QNaN || bClass == float_QNaN) {
        if (! quiet) float_raise(status, float_flag_invalid);
        return float_relation_unordered;
    }

    if (aClass == float_denormal || bClass == float_denormal) {
        float_raise(status, float_flag_denormal);
    }

    if ((a == b) || ((Bit64u) ((a | b)<<1) == 0)) return float_relation_equal;

    int aSign = extractFloat64Sign(a);
    int bSign = extractFloat64Sign(b);
    if (aSign != bSign)
        return (aSign) ? float_relation_less : float_relation_greater;

    if (aSign ^ (a < b)) return float_relation_less;
    return float_relation_greater;
}

/*----------------------------------------------------------------------------
| Compare between two double precision floating point numbers and return the
| smaller of them.
*----------------------------------------------------------------------------*/

float64 float64_min(float64 a, float64 b, float_status_t &status)
{
  if (get_denormals_are_zeros(status)) {
    a = float64_denormal_to_zero(a);
    b = float64_denormal_to_zero(b);
  }

  return (float64_compare(a, b, status) == float_relation_less) ? a : b;
}

/*----------------------------------------------------------------------------
| Compare between two double precision floating point numbers and return the
| larger of them.
*----------------------------------------------------------------------------*/

float64 float64_max(float64 a, float64 b, float_status_t &status)
{
  if (get_denormals_are_zeros(status)) {
    a = float64_denormal_to_zero(a);
    b = float64_denormal_to_zero(b);
  }

  return (float64_compare(a, b, status) == float_relation_greater) ? a : b;
}

/*----------------------------------------------------------------------------
| Compare between two  double precision  floating point numbers and  return the
| smaller/larger of them. The operation  is performed according to the IEC/IEEE
| Standard for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float64 float64_minmax(float64 a, float64 b, int is_max, int is_abs, float_status_t &status)
{
    if (get_denormals_are_zeros(status)) {
        a = float64_denormal_to_zero(a);
        b = float64_denormal_to_zero(b);
    }

    if (float64_is_nan(a) || float64_is_nan(b)) {
        if (float64_is_signaling_nan(a)) {
            return propagateFloat64NaN(a, status);
        }
        if (float64_is_signaling_nan(b)) {
            return propagateFloat64NaN(b, status);
        }
        if (! float64_is_nan(b)) {
            if (float64_is_denormal(b))
                float_raise(status, float_flag_denormal);
            return b;
        }
        if (! float64_is_nan(a)) {
            if (float64_is_denormal(a))
                float_raise(status, float_flag_denormal);
            return a;
        }
        return propagateFloat64NaN(a, b, status);
    }

    float64 tmp_a = a, tmp_b = b;
    if (is_abs) {
        tmp_a &= ~BX_CONST64(0x8000000000000000); // clear the sign bit
        tmp_b &= ~BX_CONST64(0x8000000000000000);
    }

    int aSign = extractFloat64Sign(tmp_a);
    int bSign = extractFloat64Sign(tmp_b);

    if (float64_is_denormal(a) || float64_is_denormal(b))
        float_raise(status, float_flag_denormal);

    if (aSign != bSign) {
        if (! is_max) {
            return aSign ? a : b;
        } else {
            return aSign ? b : a;
        }
    } else {
        if (! is_max) {
            return (aSign ^ (tmp_a < tmp_b)) ? a : b;
        } else {
            return (aSign ^ (tmp_a < tmp_b)) ? b : a;
        }
    }
}

#ifdef FLOATX80

/*----------------------------------------------------------------------------
| Returns the result of converting the 32-bit two's complement integer `a'
| to the extended double-precision floating-point format.  The conversion
| is performed according to the IEC/IEEE Standard for Binary Floating-Point
| Arithmetic.
*----------------------------------------------------------------------------*/

floatx80 int32_to_floatx80(Bit32s a)
{
    if (a == 0) return packFloatx80(0, 0, 0);
    int   zSign = (a < 0);
    Bit32u absA = zSign ? -a : a;
    int    shiftCount = countLeadingZeros32(absA) + 32;
    Bit64u zSig = absA;
    return packFloatx80(zSign, 0x403E - shiftCount, zSig<<shiftCount);
}

/*----------------------------------------------------------------------------
| Returns the result of converting the 64-bit two's complement integer `a'
| to the extended double-precision floating-point format.  The conversion
| is performed according to the IEC/IEEE Standard for Binary Floating-Point
| Arithmetic.
*----------------------------------------------------------------------------*/

floatx80 int64_to_floatx80(Bit64s a)
{
    if (a == 0) return packFloatx80(0, 0, 0);
    int   zSign = (a < 0);
    Bit64u absA = zSign ? -a : a;
    int    shiftCount = countLeadingZeros64(absA);
    return packFloatx80(zSign, 0x403E - shiftCount, absA<<shiftCount);
}

/*----------------------------------------------------------------------------
| Returns the result of converting the single-precision floating-point value
| `a' to the extended double-precision floating-point format.  The conversion
| is performed according to the IEC/IEEE Standard for Binary Floating-Point
| Arithmetic.
*----------------------------------------------------------------------------*/

floatx80 float32_to_floatx80(float32 a, float_status_t &status)
{
    Bit32u aSig = extractFloat32Frac(a);
    Bit16s aExp = extractFloat32Exp(a);
    int aSign = extractFloat32Sign(a);
    if (aExp == 0xFF) {
        if (aSig) return commonNaNToFloatx80(float32ToCommonNaN(a, status));
        return packFloatx80(aSign, 0x7FFF, BX_CONST64(0x8000000000000000));
    }
    if (aExp == 0) {
        if (aSig == 0) return packFloatx80(aSign, 0, 0);
        float_raise(status, float_flag_denormal);
        normalizeFloat32Subnormal(aSig, &aExp, &aSig);
    }
    aSig |= 0x00800000;
    return packFloatx80(aSign, aExp + 0x3F80, ((Bit64u) aSig)<<40);
}

/*----------------------------------------------------------------------------
| Returns the result of converting the double-precision floating-point value
| `a' to the extended double-precision floating-point format.  The conversion
| is performed according to the IEC/IEEE Standard for Binary Floating-Point
| Arithmetic.
*----------------------------------------------------------------------------*/

floatx80 float64_to_floatx80(float64 a, float_status_t &status)
{
    Bit64u aSig = extractFloat64Frac(a);
    Bit16s aExp = extractFloat64Exp(a);
    int aSign = extractFloat64Sign(a);

    if (aExp == 0x7FF) {
        if (aSig) return commonNaNToFloatx80(float64ToCommonNaN(a, status));
        return packFloatx80(aSign, 0x7FFF, BX_CONST64(0x8000000000000000));
    }
    if (aExp == 0) {
        if (aSig == 0) return packFloatx80(aSign, 0, 0);
        float_raise(status, float_flag_denormal);
        normalizeFloat64Subnormal(aSig, &aExp, &aSig);
    }
    return
        packFloatx80(
            aSign, aExp + 0x3C00, (aSig | BX_CONST64(0x0010000000000000))<<11);
}

/*----------------------------------------------------------------------------
| Returns the result of converting the extended double-precision floating-
| point value `a' to the 32-bit two's complement 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 or the
| conversion overflows, the integer indefinite value is returned.
*----------------------------------------------------------------------------*/

Bit32s floatx80_to_int32(floatx80 a, float_status_t &status)
{
    Bit64u aSig = extractFloatx80Frac(a);
    Bit32s aExp = extractFloatx80Exp(a);
    int aSign = extractFloatx80Sign(a);

    // handle unsupported extended double-precision floating encodings
    if (floatx80_is_unsupported(a))
    {
        float_raise(status, float_flag_invalid);
        return int32_indefinite;
    }

    if ((aExp == 0x7FFF) && (Bit64u) (aSig<<1)) aSign = 0;
    int shiftCount = 0x4037 - aExp;
    if (shiftCount <= 0) shiftCount = 1;
    aSig = shift64RightJamming(aSig, shiftCount);
    return roundAndPackInt32(aSign, aSig, status);
}

/*----------------------------------------------------------------------------
| Returns the result of converting the extended double-precision floating-
| point value `a' to the 32-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 `a' is a NaN or the conversion overflows, the integer
| indefinite value is returned.
*----------------------------------------------------------------------------*/

Bit32s floatx80_to_int32_round_to_zero(floatx80 a, float_status_t &status)
{
    Bit32s aExp;
    Bit64u aSig, savedASig;
    Bit32s z;
    int shiftCount;

    // handle unsupported extended double-precision floating encodings
    if (floatx80_is_unsupported(a))
    {
        float_raise(status, float_flag_invalid);
        return int32_indefinite;
    }

    aSig = extractFloatx80Frac(a);
    aExp = extractFloatx80Exp(a);
    int aSign = extractFloatx80Sign(a);

    if (aExp > 0x401E) {
        float_raise(status, float_flag_invalid);
        return (Bit32s)(int32_indefinite);
    }
    if (aExp < 0x3FFF) {
        if (aExp || aSig) float_raise(status, float_flag_inexact);
        return 0;
    }
    shiftCount = 0x403E - aExp;
    savedASig = aSig;
    aSig >>= shiftCount;
    z = (Bit32s) aSig;
    if (aSign) z = -z;
    if ((z < 0) ^ aSign) {
        float_raise(status, float_flag_invalid);
        return (Bit32s)(int32_indefinite);
    }
    if ((aSig<<shiftCount) != savedASig)
    {
        float_raise(status, float_flag_inexact);
    }
    return z;
}

/*----------------------------------------------------------------------------
| Returns the result of converting the extended double-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 - which means in particular that the conversion
| is rounded according to the current rounding mode. If `a' is a NaN or the
| conversion overflows, the integer indefinite value is returned.
*----------------------------------------------------------------------------*/

Bit64s floatx80_to_int64(floatx80 a, float_status_t &status)
{
    Bit32s aExp;
    Bit64u aSig, aSigExtra;

    // handle unsupported extended double-precision floating encodings
    if (floatx80_is_unsupported(a))
    {
        float_raise(status, float_flag_invalid);
        return int64_indefinite;
    }

    aSig = extractFloatx80Frac(a);
    aExp = extractFloatx80Exp(a);
    int aSign = extractFloatx80Sign(a);

    int shiftCount = 0x403E - aExp;
    if (shiftCount <= 0)
    {
        if (shiftCount)
        {
            float_raise(status, float_flag_invalid);
            return (Bit64s)(int64_indefinite);
        }
        aSigExtra = 0;
    }
    else {
        shift64ExtraRightJamming(aSig, 0, shiftCount, &aSig, &aSigExtra);
    }

    return roundAndPackInt64(aSign, aSig, aSigExtra, status);
}

/*----------------------------------------------------------------------------
| Returns the result of converting the extended double-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 `a' is a NaN or the conversion overflows, the integer
| indefinite value is returned.
*----------------------------------------------------------------------------*/

Bit64s floatx80_to_int64_round_to_zero(floatx80 a, float_status_t &status)
{
    int aSign;
    Bit32s aExp;
    Bit64u aSig;
    Bit64s z;

    // handle unsupported extended double-precision floating encodings
    if (floatx80_is_unsupported(a))
    {
        float_raise(status, float_flag_invalid);
        return int64_indefinite;
    }

    aSig = extractFloatx80Frac(a);
    aExp = extractFloatx80Exp(a);
    aSign = extractFloatx80Sign(a);
    int shiftCount = aExp - 0x403E;
    if (0 <= shiftCount) {
        aSig &= BX_CONST64(0x7FFFFFFFFFFFFFFF);
        if ((a.exp != 0xC03E) || aSig) {
            float_raise(status, float_flag_invalid);
        }
        return (Bit64s)(int64_indefinite);
    }
    else if (aExp < 0x3FFF) {
        if (aExp | aSig) float_raise(status, float_flag_inexact);
        return 0;
    }
    z = aSig>>(-shiftCount);
    if ((Bit64u) (aSig<<(shiftCount & 63))) {
        float_raise(status, float_flag_inexact);
    }
    if (aSign) z = -z;
    return z;
}

/*----------------------------------------------------------------------------
| Returns the result of converting the extended double-precision floating-
| point value `a' to the single-precision floating-point format.  The
| conversion is performed according to the IEC/IEEE Standard for Binary
| Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float32 floatx80_to_float32(floatx80 a, float_status_t &status)
{
    Bit64u aSig = extractFloatx80Frac(a);
    Bit32s aExp = extractFloatx80Exp(a);
    int aSign = extractFloatx80Sign(a);

    // handle unsupported extended double-precision floating encodings
    if (floatx80_is_unsupported(a))
    {
        float_raise(status, float_flag_invalid);
        return float32_default_nan;
    }

    if (aExp == 0x7FFF) {
        if ((Bit64u) (aSig<<1))
            return commonNaNToFloat32(floatx80ToCommonNaN(a, status));

        return packFloat32(aSign, 0xFF, 0);
    }
    aSig = shift64RightJamming(aSig, 33);
    if (aExp || aSig) aExp -= 0x3F81;
    return roundAndPackFloat32(aSign, aExp, (Bit32u) aSig, status);
}

/*----------------------------------------------------------------------------
| Returns the result of converting the extended double-precision floating-
| point value `a' to the double-precision floating-point format.  The
| conversion is performed according to the IEC/IEEE Standard for Binary
| Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float64 floatx80_to_float64(floatx80 a, float_status_t &status)
{
    Bit32s aExp;
    Bit64u aSig, zSig;

    // handle unsupported extended double-precision floating encodings
    if (floatx80_is_unsupported(a))
    {
        float_raise(status, float_flag_invalid);
        return float64_default_nan;
    }

    aSig = extractFloatx80Frac(a);
    aExp = extractFloatx80Exp(a);
    int aSign = extractFloatx80Sign(a);

    if (aExp == 0x7FFF) {
        if ((Bit64u) (aSig<<1)) {
            return commonNaNToFloat64(floatx80ToCommonNaN(a, status));
        }
        return packFloat64(aSign, 0x7FF, 0);
    }
    zSig = shift64RightJamming(aSig, 1);
    if (aExp || aSig) aExp -= 0x3C01;
    return roundAndPackFloat64(aSign, aExp, zSig, status);
}

/*----------------------------------------------------------------------------
| Rounds the extended double-precision floating-point value `a' to an integer,
| and returns the result as an extended double-precision floating-point
| value.  The operation is performed according to the IEC/IEEE Standard for
| Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

floatx80 floatx80_round_to_int(floatx80 a, float_status_t &status)
{
    int aSign;
    Bit64u lastBitMask, roundBitsMask;
    int roundingMode = get_float_rounding_mode(status);
    floatx80 z;

    // handle unsupported extended double-precision floating encodings
    if (floatx80_is_unsupported(a))
    {
        float_raise(status, float_flag_invalid);
        return floatx80_default_nan;
    }

    Bit32s aExp = extractFloatx80Exp(a);
    Bit64u aSig = extractFloatx80Frac(a);
    if (0x403E <= aExp) {
        if ((aExp == 0x7FFF) && (Bit64u) (aSig<<1)) {
            return propagateFloatx80NaN(a, status);
        }
        return a;
    }
    if (aExp < 0x3FFF) {
        if (aExp == 0) {
            if ((aSig<<1) == 0) return a;
            float_raise(status, float_flag_denormal);
        }
        float_raise(status, float_flag_inexact);
        aSign = extractFloatx80Sign(a);
        switch (roundingMode) {
         case float_round_nearest_even:
            if ((aExp == 0x3FFE) && (Bit64u) (aSig<<1)) {
                set_float_rounding_up(status);
                return packFloatx80(aSign, 0x3FFF, BX_CONST64(0x8000000000000000));
            }
            break;
         case float_round_down:
            if (aSign) {
                set_float_rounding_up(status);
                return packFloatx80(1, 0x3FFF, BX_CONST64(0x8000000000000000));
            }
            else {
                return packFloatx80(0, 0, 0);
            }
         case float_round_up:
            if (aSign) {
                return packFloatx80(1, 0, 0);
            }
            else {
                set_float_rounding_up(status);
                return packFloatx80(0, 0x3FFF, BX_CONST64(0x8000000000000000));
            }
        }
        return packFloatx80(aSign, 0, 0);
    }
    lastBitMask = 1;
    lastBitMask <<= 0x403E - aExp;
    roundBitsMask = lastBitMask - 1;
    z = a;
    if (roundingMode == float_round_nearest_even) {
        z.fraction += lastBitMask>>1;
        if ((z.fraction & roundBitsMask) == 0) z.fraction &= ~lastBitMask;
    }
    else if (roundingMode != float_round_to_zero) {
        if (extractFloatx80Sign(z) ^ (roundingMode == float_round_up))
            z.fraction += roundBitsMask;
    }
    z.fraction &= ~roundBitsMask;
    if (z.fraction == 0) {
        z.exp++;
        z.fraction = BX_CONST64(0x8000000000000000);
    }
    if (z.fraction != a.fraction) {
        float_raise(status, float_flag_inexact);
        if (z.fraction > a.fraction || z.exp > a.exp)
            set_float_rounding_up(status);
    }
    return z;
}

/*----------------------------------------------------------------------------
| Returns the result of adding the absolute values of the extended double-
| precision floating-point values `a' and `b'.  If `zSign' is 1, the sum is
| negated before being returned.  `zSign' is ignored if the result is a NaN.
| The addition is performed according to the IEC/IEEE Standard for Binary
| Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

static floatx80 addFloatx80Sigs(floatx80 a, floatx80 b, int zSign, float_status_t &status)
{
    Bit32s aExp, bExp, zExp;
    Bit64u aSig, bSig, zSig0, zSig1;

    // handle unsupported extended double-precision floating encodings
    if (floatx80_is_unsupported(a) || floatx80_is_unsupported(b))
    {
        float_raise(status, float_flag_invalid);
        return floatx80_default_nan;
    }

    aSig = extractFloatx80Frac(a);
    aExp = extractFloatx80Exp(a);
    bSig = extractFloatx80Frac(b);
    bExp = extractFloatx80Exp(b);

    if (aExp == 0x7FFF) {
        if ((Bit64u) (aSig<<1) || ((bExp == 0x7FFF) && (Bit64u) (bSig<<1)))
            return propagateFloatx80NaN(a, b, status);
        if (bSig && (bExp == 0)) float_raise(status, float_flag_denormal);
        return a;
    }
    if (bExp == 0x7FFF) {
        if ((Bit64u) (bSig<<1)) return propagateFloatx80NaN(a, b, status);
        if (aSig && (aExp == 0)) float_raise(status, float_flag_denormal);
        return packFloatx80(zSign, 0x7FFF, BX_CONST64(0x8000000000000000));
    }
    if (aExp == 0) {
        if (aSig == 0) {
            if ((bExp == 0) && bSig) {
                float_raise(status, float_flag_denormal);
                normalizeFloatx80Subnormal(bSig, &bExp, &bSig);
            }
            return roundAndPackFloatx80(get_float_rounding_precision(status),
                    zSign, bExp, bSig, 0, status);
        }
        float_raise(status, float_flag_denormal);
        normalizeFloatx80Subnormal(aSig, &aExp, &aSig);
    }
    if (bExp == 0) {
        if (bSig == 0)
            return roundAndPackFloatx80(get_float_rounding_precision(status),
                    zSign, aExp, aSig, 0, status);

        float_raise(status, float_flag_denormal);
        normalizeFloatx80Subnormal(bSig, &bExp, &bSig);
    }
    Bit32s expDiff = aExp - bExp;
    zExp = aExp;
    if (0 < expDiff) {
        shift64ExtraRightJamming(bSig, 0,  expDiff, &bSig, &zSig1);
    }
    else if (expDiff < 0) {
        shift64ExtraRightJamming(aSig, 0, -expDiff, &aSig, &zSig1);
        zExp = bExp;
    }
    else {
        zSig0 = aSig + bSig;
        zSig1 = 0;
        goto shiftRight1;
    }
    zSig0 = aSig + bSig;
    if ((Bit64s) zSig0 < 0) goto roundAndPack;
 shiftRight1:
    shift64ExtraRightJamming(zSig0, zSig1, 1, &zSig0, &zSig1);
    zSig0 |= BX_CONST64(0x8000000000000000);
    zExp++;
 roundAndPack:
    return
        roundAndPackFloatx80(get_float_rounding_precision(status),
            zSign, zExp, zSig0, zSig1, status);
}

/*----------------------------------------------------------------------------
| Returns the result of subtracting the absolute values of the extended
| double-precision floating-point values `a' and `b'.  If `zSign' is 1, the
| difference is negated before being returned.  `zSign' is ignored if the
| result is a NaN.  The subtraction is performed according to the IEC/IEEE
| Standard for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

static floatx80 subFloatx80Sigs(floatx80 a, floatx80 b, int zSign, float_status_t &status)
{
    Bit32s aExp, bExp, zExp;
    Bit64u aSig, bSig, zSig0, zSig1;

    // handle unsupported extended double-precision floating encodings
    if (floatx80_is_unsupported(a) || floatx80_is_unsupported(b))
    {
        float_raise(status, float_flag_invalid);
        return floatx80_default_nan;
    }

    aSig = extractFloatx80Frac(a);
    aExp = extractFloatx80Exp(a);
    bSig = extractFloatx80Frac(b);
    bExp = extractFloatx80Exp(b);

    if (aExp == 0x7FFF) {
        if ((Bit64u) (aSig<<1)) return propagateFloatx80NaN(a, b, status);
        if (bExp == 0x7FFF) {
            if ((Bit64u) (bSig<<1)) return propagateFloatx80NaN(a, b, status);
            float_raise(status, float_flag_invalid);
            return floatx80_default_nan;
        }
        if (bSig && (bExp == 0)) float_raise(status, float_flag_denormal);
        return a;
    }
    if (bExp == 0x7FFF) {
        if ((Bit64u) (bSig<<1)) return propagateFloatx80NaN(a, b, status);
        if (aSig && (aExp == 0)) float_raise(status, float_flag_denormal);
        return packFloatx80(zSign ^ 1, 0x7FFF, BX_CONST64(0x8000000000000000));
    }
    if (aExp == 0) {
        if (aSig == 0) {
            if (bExp == 0) {
                if (bSig) {
                    float_raise(status, float_flag_denormal);
                    normalizeFloatx80Subnormal(bSig, &bExp, &bSig);
                    return roundAndPackFloatx80(get_float_rounding_precision(status),
                        zSign ^ 1, bExp, bSig, 0, status);
                }
                return packFloatx80(get_float_rounding_mode(status) == float_round_down, 0, 0);
            }
            return roundAndPackFloatx80(get_float_rounding_precision(status),
                    zSign ^ 1, bExp, bSig, 0, status);
        }
        float_raise(status, float_flag_denormal);
        normalizeFloatx80Subnormal(aSig, &aExp, &aSig);
    }
    if (bExp == 0) {
        if (bSig == 0)
            return roundAndPackFloatx80(get_float_rounding_precision(status),
                    zSign, aExp, aSig, 0, status);

        float_raise(status, float_flag_denormal);
        normalizeFloatx80Subnormal(bSig, &bExp, &bSig);
    }
    Bit32s expDiff = aExp - bExp;
    if (0 < expDiff) {
        shift128RightJamming(bSig, 0, expDiff, &bSig, &zSig1);
        goto aBigger;
    }
    if (expDiff < 0) {
        shift128RightJamming(aSig, 0, -expDiff, &aSig, &zSig1);
        goto bBigger;
    }
    zSig1 = 0;
    if (bSig < aSig) goto aBigger;
    if (aSig < bSig) goto bBigger;
    return packFloatx80(get_float_rounding_mode(status) == float_round_down, 0, 0);
 bBigger:
    sub128(bSig, 0, aSig, zSig1, &zSig0, &zSig1);
    zExp = bExp;
    zSign ^= 1;
    goto normalizeRoundAndPack;
 aBigger:
    sub128(aSig, 0, bSig, zSig1, &zSig0, &zSig1);
    zExp = aExp;
 normalizeRoundAndPack:
    return
        normalizeRoundAndPackFloatx80(get_float_rounding_precision(status),
            zSign, zExp, zSig0, zSig1, status);
}

/*----------------------------------------------------------------------------
| Returns the result of adding the extended double-precision floating-point
| values `a' and `b'.  The operation is performed according to the IEC/IEEE
| Standard for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

floatx80 floatx80_add(floatx80 a, floatx80 b, float_status_t &status)
{
    int aSign = extractFloatx80Sign(a);
    int bSign = extractFloatx80Sign(b);

    if (aSign == bSign)
        return addFloatx80Sigs(a, b, aSign, status);
    else
        return subFloatx80Sigs(a, b, aSign, status);
}

/*----------------------------------------------------------------------------
| Returns the result of subtracting the extended double-precision floating-
| point values `a' and `b'.  The operation is performed according to the
| IEC/IEEE Standard for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

floatx80 floatx80_sub(floatx80 a, floatx80 b, float_status_t &status)
{
    int aSign = extractFloatx80Sign(a);
    int bSign = extractFloatx80Sign(b);

    if (aSign == bSign)
        return subFloatx80Sigs(a, b, aSign, status);
    else
        return addFloatx80Sigs(a, b, aSign, status);
}

/*----------------------------------------------------------------------------
| Returns the result of multiplying the extended double-precision floating-
| point values `a' and `b'.  The operation is performed according to the
| IEC/IEEE Standard for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

floatx80 floatx80_mul(floatx80 a, floatx80 b, float_status_t &status)
{
    int aSign, bSign, zSign;
    Bit32s aExp, bExp, zExp;
    Bit64u aSig, bSig, zSig0, zSig1;

    // handle unsupported extended double-precision floating encodings
    if (floatx80_is_unsupported(a) || floatx80_is_unsupported(b))
    {
 invalid:
        float_raise(status, float_flag_invalid);
        return floatx80_default_nan;
    }

    aSig = extractFloatx80Frac(a);
    aExp = extractFloatx80Exp(a);
    aSign = extractFloatx80Sign(a);
    bSig = extractFloatx80Frac(b);
    bExp = extractFloatx80Exp(b);
    bSign = extractFloatx80Sign(b);
    zSign = aSign ^ bSign;

    if (aExp == 0x7FFF) {
        if ((Bit64u) (aSig<<1) || ((bExp == 0x7FFF) && (Bit64u) (bSig<<1))) {
            return propagateFloatx80NaN(a, b, status);
        }
        if (bExp == 0) {
            if (bSig == 0) goto invalid;
            float_raise(status, float_flag_denormal);
        }
        return packFloatx80(zSign, 0x7FFF, BX_CONST64(0x8000000000000000));
    }
    if (bExp == 0x7FFF) {
        if ((Bit64u) (bSig<<1)) return propagateFloatx80NaN(a, b, status);
        if (aExp == 0) {
            if (aSig == 0) goto invalid;
            float_raise(status, float_flag_denormal);
        }
        return packFloatx80(zSign, 0x7FFF, BX_CONST64(0x8000000000000000));
    }
    if (aExp == 0) {
        if (aSig == 0) {
            if (bSig && (bExp == 0)) float_raise(status, float_flag_denormal);
            return packFloatx80(zSign, 0, 0);
        }
        float_raise(status, float_flag_denormal);
        normalizeFloatx80Subnormal(aSig, &aExp, &aSig);
    }
    if (bExp == 0) {
        if (bSig == 0) return packFloatx80(zSign, 0, 0);
        float_raise(status, float_flag_denormal);
        normalizeFloatx80Subnormal(bSig, &bExp, &bSig);
    }
    zExp = aExp + bExp - 0x3FFE;
    mul64To128(aSig, bSig, &zSig0, &zSig1);
    if (0 < (Bit64s) zSig0) {
        shortShift128Left(zSig0, zSig1, 1, &zSig0, &zSig1);
        --zExp;
    }
    return
        roundAndPackFloatx80(get_float_rounding_precision(status),
             zSign, zExp, zSig0, zSig1, status);
}

/*----------------------------------------------------------------------------
| Returns the result of dividing the extended double-precision floating-point
| value `a' by the corresponding value `b'.  The operation is performed
| according to the IEC/IEEE Standard for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

floatx80 floatx80_div(floatx80 a, floatx80 b, float_status_t &status)
{
    int aSign, bSign, zSign;
    Bit32s aExp, bExp, zExp;
    Bit64u aSig, bSig, zSig0, zSig1;
    Bit64u rem0, rem1, rem2, term0, term1, term2;

    // handle unsupported extended double-precision floating encodings
    if (floatx80_is_unsupported(a) || floatx80_is_unsupported(b))
    {
        float_raise(status, float_flag_invalid);
        return floatx80_default_nan;
    }

    aSig = extractFloatx80Frac(a);
    aExp = extractFloatx80Exp(a);
    aSign = extractFloatx80Sign(a);
    bSig = extractFloatx80Frac(b);
    bExp = extractFloatx80Exp(b);
    bSign = extractFloatx80Sign(b);

    zSign = aSign ^ bSign;
    if (aExp == 0x7FFF) {
        if ((Bit64u) (aSig<<1)) return propagateFloatx80NaN(a, b, status);
        if (bExp == 0x7FFF) {
            if ((Bit64u) (bSig<<1)) return propagateFloatx80NaN(a, b, status);
            float_raise(status, float_flag_invalid);
            return floatx80_default_nan;
        }
        if (bSig && (bExp == 0)) float_raise(status, float_flag_denormal);
        return packFloatx80(zSign, 0x7FFF, BX_CONST64(0x8000000000000000));
    }
    if (bExp == 0x7FFF) {
        if ((Bit64u) (bSig<<1)) return propagateFloatx80NaN(a, b, status);
        if (aSig && (aExp == 0)) float_raise(status, float_flag_denormal);
        return packFloatx80(zSign, 0, 0);
    }
    if (bExp == 0) {
        if (bSig == 0) {
            if ((aExp | aSig) == 0) {
                float_raise(status, float_flag_invalid);
                return floatx80_default_nan;
            }
            float_raise(status, float_flag_divbyzero);
            return packFloatx80(zSign, 0x7FFF, BX_CONST64(0x8000000000000000));
        }
        float_raise(status, float_flag_denormal);
        normalizeFloatx80Subnormal(bSig, &bExp, &bSig);
    }
    if (aExp == 0) {
        if (aSig == 0) return packFloatx80(zSign, 0, 0);
        float_raise(status, float_flag_denormal);
        normalizeFloatx80Subnormal(aSig, &aExp, &aSig);
    }
    zExp = aExp - bExp + 0x3FFE;
    rem1 = 0;
    if (bSig <= aSig) {
        shift128Right(aSig, 0, 1, &aSig, &rem1);
        ++zExp;
    }
    zSig0 = estimateDiv128To64(aSig, rem1, bSig);
    mul64To128(bSig, zSig0, &term0, &term1);
    sub128(aSig, rem1, term0, term1, &rem0, &rem1);
    while ((Bit64s) rem0 < 0) {
        --zSig0;
        add128(rem0, rem1, 0, bSig, &rem0, &rem1);
    }
    zSig1 = estimateDiv128To64(rem1, 0, bSig);
    if ((Bit64u) (zSig1<<1) <= 8) {
        mul64To128(bSig, zSig1, &term1, &term2);
        sub128(rem1, 0, term1, term2, &rem1, &rem2);
        while ((Bit64s) rem1 < 0) {
            --zSig1;
            add128(rem1, rem2, 0, bSig, &rem1, &rem2);
        }
        zSig1 |= ((rem1 | rem2) != 0);
    }
    return
        roundAndPackFloatx80(get_float_rounding_precision(status),
            zSign, zExp, zSig0, zSig1, status);
}

/*----------------------------------------------------------------------------
| Returns the square root of the extended double-precision floating-point
| value `a'.  The operation is performed according to the IEC/IEEE Standard
| for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

floatx80 floatx80_sqrt(floatx80 a, float_status_t &status)
{
    int aSign;
    Bit32s aExp, zExp;
    Bit64u aSig0, aSig1, zSig0, zSig1, doubleZSig0;
    Bit64u rem0, rem1, rem2, rem3, term0, term1, term2, term3;

    // handle unsupported extended double-precision floating encodings
    if (floatx80_is_unsupported(a))
    {
        float_raise(status, float_flag_invalid);
        return floatx80_default_nan;
    }

    aSig0 = extractFloatx80Frac(a);
    aExp = extractFloatx80Exp(a);
    aSign = extractFloatx80Sign(a);
    if (aExp == 0x7FFF) {
        if ((Bit64u) (aSig0<<1)) return propagateFloatx80NaN(a, status);
        if (! aSign) return a;
        float_raise(status, float_flag_invalid);
        return floatx80_default_nan;
    }
    if (aSign) {
        if ((aExp | aSig0) == 0) return a;
        float_raise(status, float_flag_invalid);
        return floatx80_default_nan;
    }
    if (aExp == 0) {
        if (aSig0 == 0) return packFloatx80(0, 0, 0);
        float_raise(status, float_flag_denormal);
        normalizeFloatx80Subnormal(aSig0, &aExp, &aSig0);
    }
    zExp = ((aExp - 0x3FFF)>>1) + 0x3FFF;
    zSig0 = estimateSqrt32(aExp, aSig0>>32);
    shift128Right(aSig0, 0, 2 + (aExp & 1), &aSig0, &aSig1);
    zSig0 = estimateDiv128To64(aSig0, aSig1, zSig0<<32) + (zSig0<<30);
    doubleZSig0 = zSig0<<1;
    mul64To128(zSig0, zSig0, &term0, &term1);
    sub128(aSig0, aSig1, term0, term1, &rem0, &rem1);
    while ((Bit64s) rem0 < 0) {
        --zSig0;
        doubleZSig0 -= 2;
        add128(rem0, rem1, zSig0>>63, doubleZSig0 | 1, &rem0, &rem1);
    }
    zSig1 = estimateDiv128To64(rem1, 0, doubleZSig0);
    if ((zSig1 & BX_CONST64(0x3FFFFFFFFFFFFFFF)) <= 5) {
        if (zSig1 == 0) zSig1 = 1;
        mul64To128(doubleZSig0, zSig1, &term1, &term2);
        sub128(rem1, 0, term1, term2, &rem1, &rem2);
        mul64To128(zSig1, zSig1, &term2, &term3);
        sub192(rem1, rem2, 0, 0, term2, term3, &rem1, &rem2, &rem3);
        while ((Bit64s) rem1 < 0) {
            --zSig1;
            shortShift128Left(0, zSig1, 1, &term2, &term3);
            term3 |= 1;
            term2 |= doubleZSig0;
            add192(rem1, rem2, rem3, 0, term2, term3, &rem1, &rem2, &rem3);
        }
        zSig1 |= ((rem1 | rem2 | rem3) != 0);
    }
    shortShift128Left(0, zSig1, 1, &zSig0, &zSig1);
    zSig0 |= doubleZSig0;
    return
        roundAndPackFloatx80(get_float_rounding_precision(status),
            0, zExp, zSig0, zSig1, status);
}

#endif

#ifdef FLOAT128

/*----------------------------------------------------------------------------
| Returns the result of converting the extended double-precision floating-
| point value `a' to the quadruple-precision floating-point format. The
| conversion is performed according to the IEC/IEEE Standard for Binary
| Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float128 floatx80_to_float128(floatx80 a, float_status_t &status)
{
    Bit64u zSig0, zSig1;

    Bit64u aSig = extractFloatx80Frac(a);
    Bit32s aExp = extractFloatx80Exp(a);
    int   aSign = extractFloatx80Sign(a);

    if ((aExp == 0x7FFF) && (Bit64u) (aSig<<1))
        return commonNaNToFloat128(floatx80ToCommonNaN(a, status));

    shift128Right(aSig<<1, 0, 16, &zSig0, &zSig1);
    return packFloat128(aSign, aExp, zSig0, zSig1);
}

/*----------------------------------------------------------------------------
| Returns the result of converting the quadruple-precision floating-point
| value `a' to the extended double-precision floating-point format.  The
| conversion is performed according to the IEC/IEEE Standard for Binary
| Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

floatx80 float128_to_floatx80(float128 a, float_status_t &status)
{
    Bit32s aExp;
    Bit64u aSig0, aSig1;

    aSig1 = extractFloat128Frac1(a);
    aSig0 = extractFloat128Frac0(a);
    aExp = extractFloat128Exp(a);
    int aSign = extractFloat128Sign(a);

    if (aExp == 0x7FFF) {
        if (aSig0 | aSig1)
            return commonNaNToFloatx80(float128ToCommonNaN(a, status));

        return packFloatx80(aSign, 0x7FFF, BX_CONST64(0x8000000000000000));
    }

    if (aExp == 0) {
        if ((aSig0 | aSig1) == 0) return packFloatx80(aSign, 0, 0);
        float_raise(status, float_flag_denormal);
        normalizeFloat128Subnormal(aSig0, aSig1, &aExp, &aSig0, &aSig1);
    }
    else aSig0 |= BX_CONST64(0x0001000000000000);

    shortShift128Left(aSig0, aSig1, 15, &aSig0, &aSig1);
    return roundAndPackFloatx80(80, aSign, aExp, aSig0, aSig1, status);
}

/*----------------------------------------------------------------------------
| Returns the result of multiplying the extended double-precision floating-
| point value `a' and quadruple-precision floating point value `b'. The
| operation is performed according to the IEC/IEEE Standard for Binary
| Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

floatx80 floatx80_mul(floatx80 a, float128 b, float_status_t &status)
{
    Bit32s aExp, bExp, zExp;
    Bit64u aSig, bSig0, bSig1, zSig0, zSig1, zSig2;
    int aSign, bSign, zSign;

    // handle unsupported extended double-precision floating encodings
    if (floatx80_is_unsupported(a))
    {
 invalid:
        float_raise(status, float_flag_invalid);
        return floatx80_default_nan;
    }

    aSig = extractFloatx80Frac(a);
    aExp = extractFloatx80Exp(a);
    aSign = extractFloatx80Sign(a);
    bSig0 = extractFloat128Frac0(b);
    bSig1 = extractFloat128Frac1(b);
    bExp = extractFloat128Exp(b);
    bSign = extractFloat128Sign(b);

    zSign = aSign ^ bSign;

    if (aExp == 0x7FFF) {
        if ((Bit64u) (aSig<<1)
             || ((bExp == 0x7FFF) && (bSig0 | bSig1)))
        {
            floatx80 r = commonNaNToFloatx80(float128ToCommonNaN(b, status));
            return propagateFloatx80NaN(a, r, status);
        }
        if (bExp == 0) {
            if ((bSig0 | bSig1) == 0) goto invalid;
            float_raise(status, float_flag_denormal);
        }
        return packFloatx80(zSign, 0x7FFF, BX_CONST64(0x8000000000000000));
    }
    if (bExp == 0x7FFF) {
        if (bSig0 | bSig1) {
            floatx80 r = commonNaNToFloatx80(float128ToCommonNaN(b, status));
            return propagateFloatx80NaN(a, r, status);
        }
        if (aExp == 0) {
            if (aSig == 0) goto invalid;
            float_raise(status, float_flag_denormal);
        }
        return packFloatx80(zSign, 0x7FFF, BX_CONST64(0x8000000000000000));
    }
    if (aExp == 0) {
        if (aSig == 0) {
            if ((bExp == 0) && (bSig0 | bSig1)) float_raise(status, float_flag_denormal);
            return packFloatx80(zSign, 0, 0);
        }
        float_raise(status, float_flag_denormal);
        normalizeFloatx80Subnormal(aSig, &aExp, &aSig);
    }
    if (bExp == 0) {
        if ((bSig0 | bSig1) == 0) return packFloatx80(zSign, 0, 0);
        float_raise(status, float_flag_denormal);
        normalizeFloat128Subnormal(bSig0, bSig1, &bExp, &bSig0, &bSig1);
    }
    else bSig0 |= BX_CONST64(0x0001000000000000);

    zExp = aExp + bExp - 0x3FFE;
    shortShift128Left(bSig0, bSig1, 15, &bSig0, &bSig1);
    mul128By64To192(bSig0, bSig1, aSig, &zSig0, &zSig1, &zSig2);
    if (0 < (Bit64s) zSig0) {
        shortShift128Left(zSig0, zSig1, 1, &zSig0, &zSig1);
        --zExp;
    }
    return
        roundAndPackFloatx80(get_float_rounding_precision(status),
             zSign, zExp, zSig0, zSig1, status);
}

/*----------------------------------------------------------------------------
| Returns the result of adding the absolute values of the quadruple-precision
| floating-point values `a' and `b'. If `zSign' is 1, the sum is negated
| before being returned. `zSign' is ignored if the result is a NaN.
| The addition is performed according to the IEC/IEEE Standard for Binary
| Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

static float128 addFloat128Sigs(float128 a, float128 b, int zSign, float_status_t &status)
{
    Bit32s aExp, bExp, zExp;
    Bit64u aSig0, aSig1, bSig0, bSig1, zSig0, zSig1, zSig2;
    Bit32s expDiff;

    aSig1 = extractFloat128Frac1(a);
    aSig0 = extractFloat128Frac0(a);
    aExp = extractFloat128Exp(a);
    bSig1 = extractFloat128Frac1(b);
    bSig0 = extractFloat128Frac0(b);
    bExp = extractFloat128Exp(b);
    expDiff = aExp - bExp;

    if (0 < expDiff) {
        if (aExp == 0x7FFF) {
            if (aSig0 | aSig1) return propagateFloat128NaN(a, b, status);
            return a;
        }
        if (bExp == 0) --expDiff;
        else bSig0 |= BX_CONST64(0x0001000000000000);
        shift128ExtraRightJamming(bSig0, bSig1, 0, expDiff, &bSig0, &bSig1, &zSig2);
        zExp = aExp;
    }
    else if (expDiff < 0) {
        if (bExp == 0x7FFF) {
            if (bSig0 | bSig1) return propagateFloat128NaN(a, b, status);
            return packFloat128(zSign, 0x7FFF, 0, 0);
        }
        if (aExp == 0) ++expDiff;
        else aSig0 |= BX_CONST64(0x0001000000000000);
        shift128ExtraRightJamming(aSig0, aSig1, 0, -expDiff, &aSig0, &aSig1, &zSig2);
        zExp = bExp;
    }
    else {
        if (aExp == 0x7FFF) {
            if (aSig0 | aSig1 | bSig0 | bSig1)
                return propagateFloat128NaN(a, b, status);

            return a;
        }
        add128(aSig0, aSig1, bSig0, bSig1, &zSig0, &zSig1);
        if (aExp == 0) return packFloat128(zSign, 0, zSig0, zSig1);
        zSig2 = 0;
        zSig0 |= BX_CONST64(0x0002000000000000);
        zExp = aExp;
        goto shiftRight1;
    }
    aSig0 |= BX_CONST64(0x0001000000000000);
    add128(aSig0, aSig1, bSig0, bSig1, &zSig0, &zSig1);
    --zExp;
    if (zSig0 < BX_CONST64(0x0002000000000000)) goto roundAndPack;
    ++zExp;
 shiftRight1:
    shift128ExtraRightJamming(zSig0, zSig1, zSig2, 1, &zSig0, &zSig1, &zSig2);
 roundAndPack:
    return roundAndPackFloat128(zSign, zExp, zSig0, zSig1, zSig2, status);
}

/*----------------------------------------------------------------------------
| Returns the result of subtracting the absolute values of the quadruple-
| precision floating-point values `a' and `b'.  If `zSign' is 1, the
| difference is negated before being returned.  `zSign' is ignored if the
| result is a NaN.  The subtraction is performed according to the IEC/IEEE
| Standard for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

static float128 subFloat128Sigs(float128 a, float128 b, int zSign, float_status_t &status)
{
    Bit32s aExp, bExp, zExp;
    Bit64u aSig0, aSig1, bSig0, bSig1, zSig0, zSig1;
    Bit32s expDiff;

    aSig1 = extractFloat128Frac1(a);
    aSig0 = extractFloat128Frac0(a);
    aExp = extractFloat128Exp(a);
    bSig1 = extractFloat128Frac1(b);
    bSig0 = extractFloat128Frac0(b);
    bExp = extractFloat128Exp(b);

    expDiff = aExp - bExp;
    shortShift128Left(aSig0, aSig1, 14, &aSig0, &aSig1);
    shortShift128Left(bSig0, bSig1, 14, &bSig0, &bSig1);
    if (0 < expDiff) goto aExpBigger;
    if (expDiff < 0) goto bExpBigger;
    if (aExp == 0x7FFF) {
        if (aSig0 | aSig1 | bSig0 | bSig1)
            return propagateFloat128NaN(a, b, status);

        float_raise(status, float_flag_invalid);
        return float128_default_nan;
    }
    if (aExp == 0) {
        aExp = 1;
        bExp = 1;
    }
    if (bSig0 < aSig0) goto aBigger;
    if (aSig0 < bSig0) goto bBigger;
    if (bSig1 < aSig1) goto aBigger;
    if (aSig1 < bSig1) goto bBigger;
    return packFloat128(0, 0);

 bExpBigger:
    if (bExp == 0x7FFF) {
        if (bSig0 | bSig1) return propagateFloat128NaN(a, b, status);
        return packFloat128(zSign ^ 1, 0x7FFF, 0, 0);
    }
    if (aExp == 0) ++expDiff;
    else {
        aSig0 |= BX_CONST64(0x4000000000000000);
    }
    shift128RightJamming(aSig0, aSig1, - expDiff, &aSig0, &aSig1);
    bSig0 |= BX_CONST64(0x4000000000000000);
 bBigger:
    sub128(bSig0, bSig1, aSig0, aSig1, &zSig0, &zSig1);
    zExp = bExp;
    zSign ^= 1;
    goto normalizeRoundAndPack;
 aExpBigger:
    if (aExp == 0x7FFF) {
        if (aSig0 | aSig1) return propagateFloat128NaN(a, b, status);
        return a;
    }
    if (bExp == 0) --expDiff;
    else {
        bSig0 |= BX_CONST64(0x4000000000000000);
    }
    shift128RightJamming(bSig0, bSig1, expDiff, &bSig0, &bSig1);
    aSig0 |= BX_CONST64(0x4000000000000000);
 aBigger:
    sub128(aSig0, aSig1, bSig0, bSig1, &zSig0, &zSig1);
    zExp = aExp;
 normalizeRoundAndPack:
    --zExp;
    return normalizeRoundAndPackFloat128(zSign, zExp - 14, zSig0, zSig1, status);
}

/*----------------------------------------------------------------------------
| Returns the result of adding the quadruple-precision floating-point values
| `a' and `b'.  The operation is performed according to the IEC/IEEE Standard
| for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float128 float128_add(float128 a, float128 b, float_status_t &status)
{
    int aSign = extractFloat128Sign(a);
    int bSign = extractFloat128Sign(b);

    if (aSign == bSign) {
        return addFloat128Sigs(a, b, aSign, status);
    }
    else {
        return subFloat128Sigs(a, b, aSign, status);
    }
}

/*----------------------------------------------------------------------------
| Returns the result of subtracting the quadruple-precision floating-point
| values `a' and `b'.  The operation is performed according to the IEC/IEEE
| Standard for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float128 float128_sub(float128 a, float128 b, float_status_t &status)
{
    int aSign = extractFloat128Sign(a);
    int bSign = extractFloat128Sign(b);

    if (aSign == bSign) {
        return subFloat128Sigs(a, b, aSign, status);
    }
    else {
        return addFloat128Sigs(a, b, aSign, status);
    }
}

/*----------------------------------------------------------------------------
| Returns the result of multiplying the quadruple-precision floating-point
| values `a' and `b'.  The operation is performed according to the IEC/IEEE
| Standard for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float128 float128_mul(float128 a, float128 b, float_status_t &status)
{
    int aSign, bSign, zSign;
    Bit32s aExp, bExp, zExp;
    Bit64u aSig0, aSig1, bSig0, bSig1, zSig0, zSig1, zSig2, zSig3;

    aSig1 = extractFloat128Frac1(a);
    aSig0 = extractFloat128Frac0(a);
    aExp = extractFloat128Exp(a);
    aSign = extractFloat128Sign(a);
    bSig1 = extractFloat128Frac1(b);
    bSig0 = extractFloat128Frac0(b);
    bExp = extractFloat128Exp(b);
    bSign = extractFloat128Sign(b);

    zSign = aSign ^ bSign;
    if (aExp == 0x7FFF) {
        if ((aSig0 | aSig1) || ((bExp == 0x7FFF) && (bSig0 | bSig1))) {
            return propagateFloat128NaN(a, b, status);
        }
        if ((bExp | bSig0 | bSig1) == 0) {
            float_raise(status, float_flag_invalid);
            return float128_default_nan;
        }
        return packFloat128(zSign, 0x7FFF, 0, 0);
    }
    if (bExp == 0x7FFF) {
        if (bSig0 | bSig1) return propagateFloat128NaN(a, b, status);
        if ((aExp | aSig0 | aSig1) == 0) {
            float_raise(status, float_flag_invalid);
            return float128_default_nan;
        }
        return packFloat128(zSign, 0x7FFF, 0, 0);
    }
    if (aExp == 0) {
        if ((aSig0 | aSig1) == 0) return packFloat128(zSign, 0, 0, 0);
        float_raise(status, float_flag_denormal);
        normalizeFloat128Subnormal(aSig0, aSig1, &aExp, &aSig0, &aSig1);
    }
    if (bExp == 0) {
        if ((bSig0 | bSig1) == 0) return packFloat128(zSign, 0, 0, 0);
        float_raise(status, float_flag_denormal);
        normalizeFloat128Subnormal(bSig0, bSig1, &bExp, &bSig0, &bSig1);
    }
    zExp = aExp + bExp - 0x4000;
    aSig0 |= BX_CONST64(0x0001000000000000);
    shortShift128Left(bSig0, bSig1, 16, &bSig0, &bSig1);
    mul128To256(aSig0, aSig1, bSig0, bSig1, &zSig0, &zSig1, &zSig2, &zSig3);
    add128(zSig0, zSig1, aSig0, aSig1, &zSig0, &zSig1);
    zSig2 |= (zSig3 != 0);
    if (BX_CONST64(0x0002000000000000) <= zSig0) {
        shift128ExtraRightJamming(zSig0, zSig1, zSig2, 1, &zSig0, &zSig1, &zSig2);
        ++zExp;
    }
    return roundAndPackFloat128(zSign, zExp, zSig0, zSig1, zSig2, status);
}

/*----------------------------------------------------------------------------
| Returns the result of dividing the quadruple-precision floating-point value
| `a' by the corresponding value `b'.  The operation is performed according to
| the IEC/IEEE Standard for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float128 float128_div(float128 a, float128 b, float_status_t &status)
{
    int aSign, bSign, zSign;
    Bit32s aExp, bExp, zExp;
    Bit64u aSig0, aSig1, bSig0, bSig1, zSig0, zSig1, zSig2;
    Bit64u rem0, rem1, rem2, rem3, term0, term1, term2, term3;

    aSig1 = extractFloat128Frac1(a);
    aSig0 = extractFloat128Frac0(a);
    aExp = extractFloat128Exp(a);
    aSign = extractFloat128Sign(a);
    bSig1 = extractFloat128Frac1(b);
    bSig0 = extractFloat128Frac0(b);
    bExp = extractFloat128Exp(b);
    bSign = extractFloat128Sign(b);

    zSign = aSign ^ bSign;
    if (aExp == 0x7FFF) {
        if (aSig0 | aSig1) return propagateFloat128NaN(a, b, status);
        if (bExp == 0x7FFF) {
            if (bSig0 | bSig1) return propagateFloat128NaN(a, b, status);
            float_raise(status, float_flag_invalid);
            return float128_default_nan;
        }
        return packFloat128(zSign, 0x7FFF, 0, 0);
    }
    if (bExp == 0x7FFF) {
        if (bSig0 | bSig1) return propagateFloat128NaN(a, b, status);
        return packFloat128(zSign, 0, 0, 0);
    }
    if (bExp == 0) {
        if ((bSig0 | bSig1) == 0) {
            if ((aExp | aSig0 | aSig1) == 0) {
                float_raise(status, float_flag_invalid);
                return float128_default_nan;
            }
            float_raise(status, float_flag_divbyzero);
            return packFloat128(zSign, 0x7FFF, 0, 0);
        }
        float_raise(status, float_flag_denormal);
        normalizeFloat128Subnormal(bSig0, bSig1, &bExp, &bSig0, &bSig1);
    }
    if (aExp == 0) {
        if ((aSig0 | aSig1) == 0) return packFloat128(zSign, 0, 0, 0);
        float_raise(status, float_flag_denormal);
        normalizeFloat128Subnormal(aSig0, aSig1, &aExp, &aSig0, &aSig1);
    }
    zExp = aExp - bExp + 0x3FFD;
    shortShift128Left(
        aSig0 | BX_CONST64(0x0001000000000000), aSig1, 15, &aSig0, &aSig1);
    shortShift128Left(
        bSig0 | BX_CONST64(0x0001000000000000), bSig1, 15, &bSig0, &bSig1);
    if (le128(bSig0, bSig1, aSig0, aSig1)) {
        shift128Right(aSig0, aSig1, 1, &aSig0, &aSig1);
        ++zExp;
    }
    zSig0 = estimateDiv128To64(aSig0, aSig1, bSig0);
    mul128By64To192(bSig0, bSig1, zSig0, &term0, &term1, &term2);
    sub192(aSig0, aSig1, 0, term0, term1, term2, &rem0, &rem1, &rem2);
    while ((Bit64s) rem0 < 0) {
        --zSig0;
        add192(rem0, rem1, rem2, 0, bSig0, bSig1, &rem0, &rem1, &rem2);
    }
    zSig1 = estimateDiv128To64(rem1, rem2, bSig0);
    if ((zSig1 & 0x3FFF) <= 4) {
        mul128By64To192(bSig0, bSig1, zSig1, &term1, &term2, &term3);
        sub192(rem1, rem2, 0, term1, term2, term3, &rem1, &rem2, &rem3);
        while ((Bit64s) rem1 < 0) {
            --zSig1;
            add192(rem1, rem2, rem3, 0, bSig0, bSig1, &rem1, &rem2, &rem3);
        }
        zSig1 |= ((rem1 | rem2 | rem3) != 0);
    }
    shift128ExtraRightJamming(zSig0, zSig1, 0, 15, &zSig0, &zSig1, &zSig2);
    return roundAndPackFloat128(zSign, zExp, zSig0, zSig1, zSig2, status);
}

/*----------------------------------------------------------------------------
| Returns the result of converting the 64-bit two's complement integer `a' to
| the quadruple-precision floating-point format.  The conversion is performed
| according to the IEC/IEEE Standard for Binary Floating-Point Arithmetic.
*----------------------------------------------------------------------------*/

float128 int64_to_float128(Bit64s a)
{
    Bit64u zSig0, zSig1;

    if (a == 0) return packFloat128(0, 0, 0, 0);
    int zSign = (a < 0);
    Bit64u absA = zSign ? - a : a;
    Bit8u shiftCount = countLeadingZeros64(absA) + 49;
    Bit32s zExp = 0x406E - shiftCount;
    if (64 <= shiftCount) {
        zSig1 = 0;
        zSig0 = absA;
        shiftCount -= 64;
    }
    else {
        zSig1 = absA;
        zSig0 = 0;
    }
    shortShift128Left(zSig0, zSig1, shiftCount, &zSig0, &zSig1);
    return packFloat128(zSign, zExp, zSig0, zSig1);
}

#endif