/*	$NetBSD: softfloat.c,v 1.4 1999/05/06 13:56:28 kleink Exp $	*/

/*
===============================================================================

This C source file is part of the SoftFloat IEC/IEEE Floating-point
Arithmetic Package, Release 1a.

Written by John R. Hauser.  This work was made possible by the International
Computer Science Institute, located at Suite 600, 1947 Center Street,
Berkeley, California 94704.  Funding was provided in part 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/
softfloat.html'.

THIS PACKAGE IS DISTRIBUTED AS IS, FOR FREE.  Although reasonable effort has
been made to avoid it, THIS PACKAGE MAY CONTAIN FAULTS THAT WILL AT TIMES
RESULT IN INCORRECT BEHAVIOR.  USE OF THIS PACKAGE IS RESTRICTED TO PERSONS
AND ORGANIZATIONS WHO CAN AND WILL TAKE FULL RESPONSIBILITY FOR ANY AND ALL
LOSSES, COSTS, OR OTHER PROBLEMS ARISING FROM ITS USE.

Derivative works are acceptable, even for commercial purposes, so long as
(1) they include prominent notice that the work is derivative, and (2) they
include prominent notice akin to these three paragraphs for those parts of
this code that are retained.

===============================================================================
*/

#include "environment.h"
#include "softfloat.h"

/*
-------------------------------------------------------------------------------
Floating-point rounding mode and exception flags.
-------------------------------------------------------------------------------
*/
uint8 float_exception_flags = 0;
uint8 float_rounding_mode = float_round_nearest_even;

/*
-------------------------------------------------------------------------------
Functions and definitions to determine:  (1) what (if anything) happens when
exceptions are raised, (2) how signaling NaNs are distinguished from quiet
NaNs, (3) the default generated quiet NaNs, and (4) how NaNs are propagated
from function inputs to output.  These details are target-specific.
-------------------------------------------------------------------------------
*/
#include "softfloat-specialize.h"

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

/* Local prototypes */

INLINE bits32 extractFloat32Frac( float32 a );
INLINE int16 extractFloat32Exp( float32 a );
INLINE flag extractFloat32Sign( float32 a );
INLINE flag bothZeroFloat32( float32 a, float32 b );
INLINE float32 packFloat32( flag zSign, int16 zExp, bits32 zSig );
INLINE bits32 extractFloat64Frac1( float64 a );
INLINE bits32 extractFloat64Frac0( float64 a );
INLINE int16 extractFloat64Exp( float64 a );
INLINE flag extractFloat64Sign( float64 a );
INLINE flag bothZeroFloat64( float64 a, float64 b );
INLINE float64 packFloat64( flag zSign, int16 zExp, bits32 zSig0, bits32 zSig1 );

/*
-------------------------------------------------------------------------------
Returns the fraction bits of the single-precision floating-point value `a'.
-------------------------------------------------------------------------------
*/
INLINE bits32 extractFloat32Frac( float32 a )
{

    return a & 0x007FFFFF;

}

/*
-------------------------------------------------------------------------------
Returns the exponent bits of the single-precision floating-point value `a'.
-------------------------------------------------------------------------------
*/
INLINE int16 extractFloat32Exp( float32 a )
{

    return ( a>>23 ) & 0xFF;

}

/*
-------------------------------------------------------------------------------
Returns the sign bit of the single-precision floating-point value `a'.
-------------------------------------------------------------------------------
*/
INLINE flag extractFloat32Sign( float32 a )
{

    return a>>31;

}

/*
-------------------------------------------------------------------------------
Returns true if the single-precision floating-point values `a' and `b' are
both zero.  Otherwise, returns false.
-------------------------------------------------------------------------------
*/
INLINE flag bothZeroFloat32( float32 a, float32 b )
{

    return ( ( ( a | b )<<1 ) == 0 );

}

/*
-------------------------------------------------------------------------------
Normalizes the subnormal single-precision floating-point value represented
by the denormalized significand `aSig'.  The normalized exponent and
significand are stored at the locations pointed to by `zExpPtr' and
`zSigPtr', respectively.
-------------------------------------------------------------------------------
*/
static void
 normalizeFloat32Subnormal( bits32 aSig, int16 *zExpPtr, bits32 *zSigPtr )
{
    int8 shiftCount;

    shiftCount = countLeadingZeros( aSig ) - 8;
    *zSigPtr = aSig<<shiftCount;
    *zExpPtr = 1 - shiftCount;

}

/*
-------------------------------------------------------------------------------
Packs the sign `zSign', exponent `zExp', and significand `zSig' into a
single-precision floating-point value, returning the result.  After being
shifted into the proper positions, the three fields are simply added
together to form the result.  This means that any integer portion of `zSig'
will be added into the exponent.  Since a properly normalized significand
will have an integer portion equal to 1, the `zExp' input should be 1 less
than the desired result exponent whenever `zSig' is a complete, normalized
significand.
-------------------------------------------------------------------------------
*/
INLINE float32 packFloat32( flag zSign, int16 zExp, bits32 zSig )
{

    return ( zSign<<31 ) + ( zExp<<23 ) + zSig;

}

/*
-------------------------------------------------------------------------------
Takes an abstract floating-point value having sign `zSign', exponent `zExp',
and significand `zSig', and returns the proper single-precision floating-
point value corresponding to the abstract input.  Ordinarily, the abstract
value is simply rounded and packed into the single-precision format, with
the inexact exception raised if the abstract input cannot be represented
exactly.  If the abstract value is too large, however, the overflow and
inexact exceptions are raised and an infinity or maximal finite value is
returned.  If the abstract value is too small, the input value is rounded to
a subnormal number, and the underflow and inexact exceptions are raised if
the abstract input cannot be represented exactly as a subnormal single-
precision floating-point number.
    The input significand `zSig' has its binary point between bits 30
and 29, which is 7 bits to the left of the usual location.  This shifted
significand must be normalized or smaller.  If `zSig' is not normalized,
`zExp' must be 0; in that case, the result returned is a subnormal number,
and it must not require rounding.  In the usual case that `zSig' is
normalized, `zExp' must be 1 less than the ``true'' floating-point exponent.
The handling of underflow and overflow follows the IEC/IEEE Standard for
Binary Floating-point Arithmetic.
-------------------------------------------------------------------------------
*/
static float32 roundAndPackFloat32( flag zSign, int16 zExp, bits32 zSig )
{
    uint8 roundingMode;
    flag roundNearestEven;
    int8 roundIncrement, roundBits;
    flag isTiny;

    roundingMode = float_rounding_mode;
    roundNearestEven = roundingMode == float_round_nearest_even;
    roundIncrement = 0x40;
    if ( ! roundNearestEven ) {
        if ( roundingMode == float_round_to_zero ) {
            roundIncrement = 0;
        }
        else {
            roundIncrement = 0x7F;
            if ( zSign ) {
                if ( roundingMode == float_round_up ) roundIncrement = 0;
            }
            else {
                if ( roundingMode == float_round_down ) roundIncrement = 0;
            }
        }
    }
    roundBits = zSig & 0x7F;
    if ( 0xFE - 1 <= ( (bits16) zExp ) ) {
        if (    ( 0xFE - 1 < zExp )
             || (    ( zExp == 0xFE - 1 )
                  && ( ( (sbits32) ( zSig + roundIncrement ) ) < 0 ) )
           ) {
            float_raise( float_flag_overflow | float_flag_inexact );
            return packFloat32( zSign, 0xFF, 0 ) - ( roundIncrement == 0 );
        }
        if ( zExp < 0 ) {
            isTiny =
                   ( float_detect_tininess == float_tininess_before_rounding )
                || ( zExp < -1 )
                || ( zSig + roundIncrement < 0x80000000 );
            shiftDown32Jamming( zSig, - zExp, &zSig );
            zExp = 0;
            roundBits = zSig & 0x7F;
            if ( isTiny && roundBits ) float_raise( float_flag_underflow );
        }
    }
    if ( roundBits ) float_exception_flags |= float_flag_inexact;
    zSig = ( zSig + roundIncrement )>>7;
    zSig &= ~ ( ( ( roundBits ^ 0x40 ) == 0 ) & roundNearestEven );
    if ( zSig == 0 ) zExp = 0;
    return packFloat32( zSign, zExp, zSig );

}

/*
-------------------------------------------------------------------------------
Takes an abstract floating-point value having sign `zSign', exponent `zExp',
and significand `zSig', and returns the proper single-precision floating-
point value corresponding to the abstract input.  This routine is just like
`roundAndPackFloat32' except that `zSig' does not have to be normalized in
any way.  In all cases, `zExp' must be 1 less than the ``true'' floating-
point exponent.
-------------------------------------------------------------------------------
*/
static float32
 normalizeRoundAndPackFloat32( flag zSign, int16 zExp, bits32 zSig )
{
    int8 shiftCount;

    shiftCount = countLeadingZeros( zSig ) - 1;
    return roundAndPackFloat32( zSign, zExp - shiftCount, zSig<<shiftCount );

}

/*
-------------------------------------------------------------------------------
Returns the least-significant 32 fraction bits of the double-precision
floating-point value `a'.
-------------------------------------------------------------------------------
*/
INLINE bits32 extractFloat64Frac1( float64 a )
{

    return a.low;

}

/*
-------------------------------------------------------------------------------
Returns the most-significant 20 fraction bits of the double-precision
floating-point value `a'.
-------------------------------------------------------------------------------
*/
INLINE bits32 extractFloat64Frac0( float64 a )
{

    return a.high & 0x000FFFFF;

}

/*
-------------------------------------------------------------------------------
Returns the exponent bits of the double-precision floating-point value `a'.
-------------------------------------------------------------------------------
*/
INLINE int16 extractFloat64Exp( float64 a )
{

    return ( a.high>>20 ) & 0x7FF;

}

/*
-------------------------------------------------------------------------------
Returns the sign bit of the double-precision floating-point value `a'.
-------------------------------------------------------------------------------
*/
INLINE flag extractFloat64Sign( float64 a )
{

    return a.high>>31;

}

/*
-------------------------------------------------------------------------------
Returns true if the double-precision floating-point values `a' and `b' are
both zero.  Otherwise, returns false.
-------------------------------------------------------------------------------
*/
INLINE flag bothZeroFloat64( float64 a, float64 b )
{

    return ( ( ( a.high | b.high )<<1 ) | a.low | b.low ) == 0;

}

/*
-------------------------------------------------------------------------------
Normalizes the subnormal double-precision floating-point value represented
by the denormalized significand formed by the concatenation of `aSig0' and
`aSig1'.  The normalized exponent is stored at the location pointed to by
`zExpPtr'.  The most significant 21 bits of the normalized significand are
stored at the location pointed to by `zSig0Ptr', and the least significant
32 bits of the normalized significand are stored at the location pointed to
by `zSig1Ptr'.
-------------------------------------------------------------------------------
*/
static void
 normalizeFloat64Subnormal(
     bits32 aSig0,
     bits32 aSig1,
     int16 *zExpPtr,
     bits32 *zSig0Ptr,
     bits32 *zSig1Ptr
 )
{
    int8 shiftCount;

    if ( aSig0 == 0 ) {
        shiftCount = countLeadingZeros( aSig1 ) - 11;
        if ( shiftCount < 0 ) {
            *zSig0Ptr = aSig1>>( - shiftCount );
            *zSig1Ptr = aSig1<<( shiftCount & 31 );
        }
        else {
            *zSig0Ptr = aSig1<<shiftCount;
            *zSig1Ptr = 0;
        }
        *zExpPtr = - shiftCount - 31;
    }
    else {
        shiftCount = countLeadingZeros( aSig0 ) - 11;
        shortShiftUp64( aSig0, aSig1, shiftCount, zSig0Ptr, zSig1Ptr );
        *zExpPtr = 1 - shiftCount;
    }

}

/*
-------------------------------------------------------------------------------
Packs the sign `zSign', the exponent `zExp', and the significand formed by
the concatenation of `zSig0' and `zSig1' into a double-precision floating-
point value, returning the result.  After being shifted into the proper
positions, the three fields `zSign', `zExp', and `zSig0' are simply added
together to form the most significant 32 bits of the result.  This means
that any integer portion of `zSig0' will be added into the exponent.  Since
a properly normalized significand will have an integer portion equal to 1,
the `zExp' input should be 1 less than the desired result exponent whenever
`zSig0' and `zSig1' concatenated form a complete, normalized significand.
-------------------------------------------------------------------------------
*/
INLINE float64
 packFloat64( flag zSign, int16 zExp, bits32 zSig0, bits32 zSig1 )
{
    float64 z;

    z.low = zSig1;
    z.high = ( zSign<<31 ) + ( zExp<<20 ) + zSig0;
    return z;

}

/*
-------------------------------------------------------------------------------
Takes an abstract floating-point value having sign `zSign', exponent `zExp',
and extended significand formed by the concatenation of `zSig0', `zSig1',
and `zSig2', and returns the proper double-precision floating-point value
corresponding to the abstract input.  Ordinarily, the abstract value is
simply rounded and packed into the double-precision format, with the inexact
exception raised if the abstract input cannot be represented exactly.  If
the abstract value is too large, however, the overflow and inexact
exceptions are raised and an infinity or maximal finite value is returned.
If the abstract value is too small, the input value is rounded to a
subnormal number, and the underflow and inexact exceptions are raised if the
abstract input cannot be represented exactly as a subnormal double-precision
floating-point number.
    The input significand must be normalized or smaller.  If the input
significand is not normalized, `zExp' must be 0; in that case, the result
returned is a subnormal number, and it must not require rounding.  In the
usual case that the input significand is normalized, `zExp' must be 1 less
than the ``true'' floating-point exponent.  The handling of underflow and
overflow follows the IEC/IEEE Standard for Binary Floating-point Arithmetic.
-------------------------------------------------------------------------------
*/
static float64
 roundAndPackFloat64(
     flag zSign, int16 zExp, bits32 zSig0, bits32 zSig1, bits32 zSig2 )
{
    uint8 roundingMode;
    flag roundNearestEven, increment;
    flag isTiny;

    roundingMode = float_rounding_mode;
    roundNearestEven = roundingMode == float_round_nearest_even;
    increment = ( (sbits32) zSig2 ) < 0;
    if ( ! roundNearestEven ) {
        if ( roundingMode == float_round_to_zero ) {
            increment = 0;
        }
        else {
            if ( zSign ) {
                increment = ( roundingMode == float_round_down ) && zSig2;
            }
            else {
                increment = ( roundingMode == float_round_up ) && zSig2;
            }
        }
    }
    if ( 0x7FE - 1 <= ( (bits16) zExp ) ) {
        if (    ( 0x7FE - 1 < zExp )
             || (    ( zExp == 0x7FE - 1 )
                  && eq64( 0x001FFFFF, 0xFFFFFFFF, zSig0, zSig1 )
                  && increment
                )
           ) {
            float_raise( float_flag_overflow | float_flag_inexact );
            if (    ( roundingMode == float_round_to_zero )
                 || ( zSign && ( roundingMode == float_round_up ) )
                 || ( ! zSign && ( roundingMode == float_round_down ) )
               ) {
                return packFloat64( zSign, 0x7FE, 0x000FFFFF, 0xFFFFFFFF );
            }
            return packFloat64( zSign, 0x7FF, 0, 0 );
        }
        if ( zExp < 0 ) {
            isTiny =
                   ( float_detect_tininess == float_tininess_before_rounding )
                || ( zExp < -1 )
                || ! increment
                || lt64( zSig0, zSig1, 0x001FFFFF, 0xFFFFFFFF );
            shiftDown64ExtraJamming(
                zSig0, zSig1, zSig2, - zExp, &zSig0, &zSig1, &zSig2 );
            zExp = 0;
            if ( isTiny && zSig2 ) float_raise( float_flag_underflow );
            if ( roundNearestEven ) {
                increment = ( (sbits32) zSig2 ) < 0;
            }
            else {
                if ( zSign ) {
                    increment = ( roundingMode == float_round_down ) && zSig2;
                }
                else {
                    increment = ( roundingMode == float_round_up ) && zSig2;
                }
            }
        }
    }
    if ( zSig2 ) float_exception_flags |= float_flag_inexact;
    if ( increment ) {
        add64( zSig0, zSig1, 0, 1, &zSig0, &zSig1 );
        zSig1 &= ~ ( ( zSig2 + zSig2 == 0 ) & roundNearestEven );
    }
    if ( ( zSig0 | zSig1 ) == 0 ) zExp = 0;
    return packFloat64( zSign, zExp, zSig0, zSig1 );

}

/*
-------------------------------------------------------------------------------
Takes an abstract floating-point value having sign `zSign', exponent `zExp',
and significand formed by the concatenation of `zSig0' and `zSig1', and
returns the proper double-precision floating-point value corresponding to
the abstract input.  This routine is just like `roundAndPackFloat64' except
that the input significand has fewer bits and does not have to be normalized
in any way.  In all cases, `zExp' must be 1 less than the ``true'' floating-
point exponent.
-------------------------------------------------------------------------------
*/
static float64
 normalizeRoundAndPackFloat64(
     flag zSign, int16 zExp, bits32 zSig0, bits32 zSig1 )
{
    int8 shiftCount;
    bits32 zSig2;

    if ( zSig0 == 0 ) {
        zSig0 = zSig1;
        zSig1 = 0;
        zExp -= 32;
    }
    shiftCount = countLeadingZeros( zSig0 ) - 11;
    if ( 0 <= shiftCount ) {
        zSig2 = 0;
        shortShiftUp64( zSig0, zSig1, shiftCount, &zSig0, &zSig1 );
    }
    else {
        shiftDown64ExtraJamming(
            zSig0, zSig1, 0, - shiftCount, &zSig0, &zSig1, &zSig2 );
    }
    zExp -= shiftCount;
    return roundAndPackFloat64( zSign, zExp, zSig0, zSig1, zSig2 );

}

/*
-------------------------------------------------------------------------------
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( int32 a )
{
    flag zSign;

    if ( a == 0 ) return 0;
    if ( a == -0x80000000 ) return packFloat32( 1, 0x9E, 0 );
    zSign = ( a < 0 );
    return normalizeRoundAndPackFloat32( zSign, 0x9C, zSign ? - a : a );

}

/*
-------------------------------------------------------------------------------
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( int32 a )
{
    flag zSign;
    bits32 absA;
    int8 shiftCount;
    bits32 zSig0, zSig1;

    if ( a == 0 ) return packFloat64( 0, 0, 0, 0 );
    zSign = ( a < 0 );
    absA = zSign ? - a : a;
    shiftCount = countLeadingZeros( absA ) - 11;
    if ( 0 <= shiftCount ) {
        zSig0 = absA<<shiftCount;
        zSig1 = 0;
    }
    else {
        shiftDown64( absA, 0, - shiftCount, &zSig0, &zSig1 );
    }
    return packFloat64( zSign, 0x412 - shiftCount, zSig0, zSig1 );

}

#if 0 /* unused */
/*
-------------------------------------------------------------------------------
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, the largest
positive integer is returned.  If the conversion overflows, the largest
integer with the same sign as `a' is returned.
-------------------------------------------------------------------------------
*/
static int32 float32_to_int32( float32 a )
{
    flag aSign;
    int16 aExp, shiftCount;
    bits32 aSig;
    bits32 zExtra;
    int32 z;
    uint8 roundingMode;

    aSig = extractFloat32Frac( a );
    aExp = extractFloat32Exp( a );
    aSign = extractFloat32Sign( a );
    shiftCount = aExp - 0x96;
    if ( 0 <= shiftCount ) {
        if ( 0x9E <= aExp ) {
            if ( a == 0xCF000000 ) return -0x80000000;
            float_raise( float_flag_invalid );
            if ( ! aSign || ( ( aExp == 0xFF ) && aSig ) ) return 0x7FFFFFFF;
            return -0x80000000;
        }
        z = ( aSig | 0x800000 )<<shiftCount;
        if ( aSign ) z = - z;
    }
    else {
        if ( aExp < 0x7E ) {
            zExtra = aExp | aSig;
            z = 0;
        }
        else {
            aSig |= 0x800000;
            zExtra = aSig<<( shiftCount & 31 );
            z = aSig>>( - shiftCount );
        }
        if ( zExtra ) float_exception_flags |= float_flag_inexact;
        roundingMode = float_rounding_mode;
        if ( roundingMode == float_round_nearest_even ) {
            if ( ( (sbits32) zExtra ) < 0 ) {
                ++z;
                if ( ( zExtra + zExtra ) == 0 ) z &= ~1;
            }
            if ( aSign ) z = - z;
        }
        else {
            zExtra = zExtra != 0;
            if ( aSign ) {
                z += ( roundingMode == float_round_down ) & zExtra;
                z = - z;
            }
            else {
                z += ( roundingMode == float_round_up ) & zExtra;
            }
        }
    }
    return z;

}
#endif /* unused */

/*
-------------------------------------------------------------------------------
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, the largest positive integer is returned.  If the conversion
overflows, the largest integer with the same sign as `a' is returned.
-------------------------------------------------------------------------------
*/
int32 float32_to_int32_round_to_zero( float32 a )
{
    flag aSign;
    int16 aExp, shiftCount;
    bits32 aSig;
    int32 z;

    aSig = extractFloat32Frac( a );
    aExp = extractFloat32Exp( a );
    aSign = extractFloat32Sign( a );
    shiftCount = aExp - 0x9E;
    if ( 0 <= shiftCount ) {
        if ( a == 0xCF000000 ) return -0x80000000;
        float_raise( float_flag_invalid );
        if ( ! aSign || ( ( aExp == 0xFF ) && aSig ) ) return 0x7FFFFFFF;
        return -0x80000000;
    }
    else if ( aExp <= 0x7E ) {
        if ( aExp | aSig ) float_exception_flags |= float_flag_inexact;
        return 0;
    }
    aSig = ( aSig | 0x800000 )<<8;
    z = aSig>>( - shiftCount );
    if ( aSig<<( shiftCount & 31 ) ) {
        float_exception_flags |= float_flag_inexact;
    }
    if ( aSign ) z = - z;
    return z;

}

/*
-------------------------------------------------------------------------------
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 )
{
    flag aSign;
    int16 aExp;
    bits32 aSig;
    bits32 zSig0, zSig1;

    aSig = extractFloat32Frac( a );
    aExp = extractFloat32Exp( a );
    aSign = extractFloat32Sign( a );
    if ( aExp == 0xFF ) {
        if ( aSig ) return float32ToFloat64NaN( a );
        return packFloat64( aSign, 0x7FF, 0, 0 );
    }
    if ( aExp == 0 ) {
        if ( aSig == 0 ) return packFloat64( aSign, 0, 0, 0 );
        normalizeFloat32Subnormal( aSig, &aExp, &aSig );
        --aExp;
    }
    shiftDown64( aSig, 0, 3, &zSig0, &zSig1 );
    return packFloat64( aSign, aExp - 0x7F + 0x3FF, zSig0, zSig1 );

}

#if 0 /* unused */
/*
-------------------------------------------------------------------------------
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, the largest
positive integer is returned.  If the conversion overflows, the largest
integer with the same sign as `a' is returned.
-------------------------------------------------------------------------------
*/

static int32 float64_to_int32( float64 a )
{
    flag aSign;
    int16 aExp, shiftCount;
    bits32 aSig0, aSig1;
    bits32 absZ, zExtra;
    int32 z;
    uint8 roundingMode;

    aSig1 = extractFloat64Frac1( a );
    aSig0 = extractFloat64Frac0( a );
    aExp = extractFloat64Exp( a );
    aSign = extractFloat64Sign( a );
    shiftCount = aExp - 0x413;
    if ( 0 <= shiftCount ) {
        if ( 11 < shiftCount ) {
            if ( ( aExp == 0x7FF ) && ( aSig0 | aSig1 ) ) aSign = 0;
            absZ = 0xC0000000;
        }
        else {
            shortShiftUp64(
                 aSig0 | 0x100000, aSig1, shiftCount, &absZ, &zExtra );
            if ( 0xC0000000 < absZ ) absZ = 0xC0000000;
        }
    }
    else {
        aSig1 = aSig1 != 0;
        if ( aExp < 0x3FE ) {
            zExtra = aExp | aSig0 | aSig1;
            absZ = 0;
        }
        else {
            aSig0 |= 0x100000;
            zExtra = ( aSig0<<( shiftCount & 31 ) ) | aSig1;
            absZ = aSig0>>( - shiftCount );
        }
    }
    roundingMode = float_rounding_mode;
    if ( roundingMode == float_round_nearest_even ) {
        if ( ( (sbits32) zExtra ) < 0 ) {
            ++absZ;
            if ( ( zExtra + zExtra ) == 0 ) absZ &= ~1;
        }
        z = aSign ? - absZ : absZ;
    }
    else {
        zExtra = zExtra != 0;
        if ( aSign ) {
            z = - ( absZ + ( ( roundingMode == float_round_down ) & zExtra ) );
        }
        else {
            z = absZ + ( ( roundingMode == float_round_up ) & zExtra );
        }
    }
    if ( ( aSign ^ ( z < 0 ) ) && z ) {
        float_raise( float_flag_invalid );
        return aSign ? -0x80000000 : 0x7FFFFFFF;
    }
    if ( zExtra ) float_exception_flags |= float_flag_inexact;
    return z;

}
#endif /* unused */

/*
-------------------------------------------------------------------------------
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, the largest positive integer is returned.  If the conversion
overflows, the largest integer with the same sign as `a' is returned.
-------------------------------------------------------------------------------
*/
int32 float64_to_int32_round_to_zero( float64 a )
{
    flag aSign;
    int16 aExp, shiftCount;
    bits32 aSig0, aSig1;
    bits32 absZ, zExtra;
    int32 z;
/*    uint8 roundingMode;*/

    aSig1 = extractFloat64Frac1( a );
    aSig0 = extractFloat64Frac0( a );
    aExp = extractFloat64Exp( a );
    aSign = extractFloat64Sign( a );
    shiftCount = aExp - 0x413;
    if ( 0 <= shiftCount ) {
        if ( 11 < shiftCount ) {
            if ( ( aExp == 0x7FF ) && ( aSig0 | aSig1 ) ) aSign = 0;
            absZ = 0xC0000000;
        }
        else {
            shortShiftUp64(
                aSig0 | 0x100000, aSig1, shiftCount, &absZ, &zExtra );
        }
    }
    else {
        if ( aExp < 0x3FE ) {
            zExtra = aExp | aSig0 | aSig1;
            absZ = 0;
        }
        else {
            aSig0 |= 0x100000;
            zExtra = ( aSig0<<( shiftCount & 31 ) ) | aSig1;
            absZ = aSig0>>( - shiftCount );
        }
    }
    z = aSign ? - absZ : absZ;
    if ( ( aSign ^ ( z < 0 ) ) && z ) {
        float_raise( float_flag_invalid );
        return aSign ? -0x80000000 : 0x7FFFFFFF;
    }
    if ( zExtra ) float_exception_flags |= float_flag_inexact;
    return z;

}

/*
-------------------------------------------------------------------------------
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.  The underflow exception is raised only if the result is a
subnormal.
-------------------------------------------------------------------------------
*/
float32 float64_to_float32( float64 a )
{
    flag aSign;
    int16 aExp;
    bits32 aSig0, aSig1, zSig;
    bits32 allZero;

    aSig1 = extractFloat64Frac1( a );
    aSig0 = extractFloat64Frac0( a );
    aExp = extractFloat64Exp( a );
    aSign = extractFloat64Sign( a );
    if ( aExp == 0x7FF ) {
        if ( aSig0 | aSig1 ) return float64ToFloat32NaN( a );
        return packFloat32( aSign, 0xFF, 0 );
    }
    shiftDown64Jamming( aSig0, aSig1, 22, &allZero, &zSig );
    if ( aExp ) zSig |= 0x40000000;
    return roundAndPackFloat32( aSign, aExp - 0x3FF + 0x7E, zSig );

}

#if 0 /* unused */
/*
-------------------------------------------------------------------------------
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.
-------------------------------------------------------------------------------
*/
static float32 float32_round_to_int( float32 a )
{
    flag aSign;
    int16 aExp;
    uint32 lastBitMask, roundBitsMask;
    uint8 roundingMode;
    float32 z;

    aExp = extractFloat32Exp( a );
    if ( 0x96 <= aExp ) {
        if ( ( aExp == 0xFF ) && extractFloat32Frac( a ) ) {
            return propagateFloat32NaN( a, a );
        }
        return a;
    }
    if ( aExp <= 0x7E ) {
        if ( a<<1 == 0 ) return a;
        float_exception_flags |= float_flag_inexact;
        aSign = extractFloat32Sign( a );
        switch ( float_rounding_mode ) {
            case float_round_nearest_even:
                if ( ( aExp == 0x7E ) && extractFloat32Frac( a ) ) {
                    return packFloat32( aSign, 0x7F, 0 );
                }
                break;
            case float_round_down:
                return
                    aSign ? packFloat32( 1, 0x7F, 0 ) : packFloat32( 0, 0, 0 );
            case float_round_up:
                return
                    aSign ? packFloat32( 1, 0, 0 ) : packFloat32( 0, 0x7F, 0 );
        }
        return packFloat32( aSign, 0, 0 );
    }
    lastBitMask = 1<<( 0x96 - aExp );
    roundBitsMask = lastBitMask - 1;
    z = a;
    roundingMode = float_rounding_mode;
    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_exception_flags |= float_flag_inexact;
    return z;

}
#endif /* unused */

/*
-------------------------------------------------------------------------------
Returns the result of adding the absolute values of the single-precision
floating-point values `a' and `b'.  If `zSign' is true, 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, flag zSign )
{
    int16 aExp, bExp, zExp;
    bits32 aSig, bSig, zSig;
    int16 expDiff;

    aSig = extractFloat32Frac( a );
    aExp = extractFloat32Exp( a );
    bSig = extractFloat32Frac( b );
    bExp = extractFloat32Exp( b );
    expDiff = aExp - bExp;
    aSig <<= 6;
    bSig <<= 6;
    if ( 0 < expDiff ) {
        if ( aExp == 0xFF ) {
            if ( aSig ) return propagateFloat32NaN( a, b );
            return a;
        }
        if ( bExp == 0 ) {
            --expDiff;
        }
        else {
            bSig |= 0x20000000;
        }
        shiftDown32Jamming( bSig, expDiff, &bSig );
        zExp = aExp;
    }
    else if ( expDiff < 0 ) {
        if ( bExp == 0xFF ) {
            if ( bSig ) return propagateFloat32NaN( a, b );
            return packFloat32( zSign, 0xFF, 0 );
        }
        if ( aExp == 0 ) {
            ++expDiff;
        }
        else {
            aSig |= 0x20000000;
        }
        shiftDown32Jamming( aSig, - expDiff, &aSig );
        zExp = bExp;
    }
    else {
        if ( aExp == 0xFF ) {
            if ( aSig | bSig ) return propagateFloat32NaN( a, b );
            return a;
        }
        if ( aExp == 0 ) return packFloat32( zSign, 0, ( aSig + bSig )>>6 );
        zSig = 0x40000000 + aSig + bSig;
        zExp = aExp;
        goto roundAndPack;
    }
    aSig |= 0x20000000;
    zSig = ( aSig + bSig )<<1;
    --zExp;
    if ( ( (sbits32) zSig ) < 0 ) {
        zSig = aSig + bSig;
        ++zExp;
    }
  roundAndPack:
    return roundAndPackFloat32( zSign, zExp, zSig );

}

/*
-------------------------------------------------------------------------------
Returns the result of subtracting the absolute values of the single-
precision floating-point values `a' and `b'.  If `zSign' is true, 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, flag zSign )
{
    int16 aExp, bExp, zExp;
    bits32 aSig, bSig, zSig;
    int16 expDiff;

    aSig = extractFloat32Frac( a );
    aExp = extractFloat32Exp( a );
    bSig = extractFloat32Frac( b );
    bExp = extractFloat32Exp( b );
    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 );
        float_raise( float_flag_invalid );
        return float32_default_nan;
    }
    if ( aExp == 0 ) {
        aExp = 1;
        bExp = 1;
    }
    if ( bSig < aSig ) goto aBigger;
    if ( aSig < bSig ) goto bBigger;
    return packFloat32( float_rounding_mode == float_round_down, 0, 0 );
  bExpBigger:
    if ( bExp == 0xFF ) {
        if ( bSig ) return propagateFloat32NaN( a, b );
        return packFloat32( zSign ^ 1, 0xFF, 0 );
    }
    if ( aExp == 0 ) {
        ++expDiff;
    }
    else {
        aSig |= 0x40000000;
    }
    shiftDown32Jamming( aSig, - expDiff, &aSig );
    bSig |= 0x40000000;
  bBigger:
    zSig = bSig - aSig;
    zExp = bExp;
    zSign ^= 1;
    goto normalizeRoundAndPack;
  aExpBigger:
    if ( aExp == 0xFF ) {
        if ( aSig ) return propagateFloat32NaN( a, b );
        return a;
    }
    if ( bExp == 0 ) {
        --expDiff;
    }
    else {
        bSig |= 0x40000000;
    }
    shiftDown32Jamming( bSig, expDiff, &bSig );
    aSig |= 0x40000000;
  aBigger:
    zSig = aSig - bSig;
    zExp = aExp;
  normalizeRoundAndPack:
    --zExp;
    return normalizeRoundAndPackFloat32( zSign, zExp, zSig );

}

/*
-------------------------------------------------------------------------------
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 )
{
    flag aSign, bSign;

    aSign = extractFloat32Sign( a );
    bSign = extractFloat32Sign( b );
    if ( aSign == bSign ) {
        return addFloat32Sigs( a, b, aSign );
    }
    else {
        return subFloat32Sigs( a, b, aSign );
    }

}

/*
-------------------------------------------------------------------------------
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 )
{
    flag aSign, bSign;

    aSign = extractFloat32Sign( a );
    bSign = extractFloat32Sign( b );
    if ( aSign == bSign ) {
        return subFloat32Sigs( a, b, aSign );
    }
    else {
        return addFloat32Sigs( a, b, aSign );
    }

}

/*
-------------------------------------------------------------------------------
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.  The underflow exception is raised
only if the result is a subnormal.
-------------------------------------------------------------------------------
*/
float32 float32_mul( float32 a, float32 b )
{
    flag aSign, bSign, zSign;
    int16 aExp, bExp, zExp;
    bits32 aSig, bSig, zSig0, zSig1;

    aSig = extractFloat32Frac( a );
    aExp = extractFloat32Exp( a );
    aSign = extractFloat32Sign( a );
    bSig = extractFloat32Frac( b );
    bExp = extractFloat32Exp( b );
    bSign = extractFloat32Sign( b );
    zSign = aSign ^ bSign;
    if ( aExp == 0xFF ) {
        if ( aSig || ( ( bExp == 0xFF ) && bSig ) ) {
            return propagateFloat32NaN( a, b );
        }
        if ( ( bExp | bSig ) == 0 ) {
            float_raise( float_flag_invalid );
            return float32_default_nan;
        }
        return packFloat32( zSign, 0xFF, 0 );
    }
    if ( bExp == 0xFF ) {
        if ( bSig ) return propagateFloat32NaN( a, b );
        if ( ( aExp | aSig ) == 0 ) {
            float_raise( float_flag_invalid );
            return float32_default_nan;
        }
        return packFloat32( zSign, 0xFF, 0 );
    }
    if ( aExp == 0 ) {
        if ( aSig == 0 ) return packFloat32( zSign, 0, 0 );
        normalizeFloat32Subnormal( aSig, &aExp, &aSig );
    }
    if ( bExp == 0 ) {
        if ( bSig == 0 ) return packFloat32( zSign, 0, 0 );
        normalizeFloat32Subnormal( bSig, &bExp, &bSig );
    }
    zExp = aExp + bExp - 0x7F;
    aSig = ( aSig | 0x800000 )<<7;
    bSig = ( bSig | 0x800000 )<<8;
    mul32To64( aSig, bSig, &zSig0, &zSig1 );
    zSig0 |= ( 0 < zSig1 );
    if ( 0 <= ( (sbits32) ( zSig0<<1 ) ) ) {
        zSig0 += zSig0;
        --zExp;
    }
    return roundAndPackFloat32( zSign, zExp, zSig0 );

}

/*
-------------------------------------------------------------------------------
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.  The underflow
exception is raised only if the result is a subnormal.
-------------------------------------------------------------------------------
*/
float32 float32_div( float32 a, float32 b )
{
    flag aSign, bSign, zSign;
    int16 aExp, bExp, zExp;
    bits32 aSig, bSig, zSig;
    bits32 rem0, rem1;
    bits32 term0, term1;

    aSig = extractFloat32Frac( a );
    aExp = extractFloat32Exp( a );
    aSign = extractFloat32Sign( a );
    bSig = extractFloat32Frac( b );
    bExp = extractFloat32Exp( b );
    bSign = extractFloat32Sign( b );
    zSign = aSign ^ bSign;
    if ( aExp == 0xFF ) {
        if ( aSig ) return propagateFloat32NaN( a, b );
        if ( bExp == 0xFF ) {
            if ( bSig ) return propagateFloat32NaN( a, b );
            float_raise( float_flag_invalid );
            return float32_default_nan;
        }
        return packFloat32( zSign, 0xFF, 0 );
    }
    if ( bExp == 0xFF ) {
        if ( bSig ) return propagateFloat32NaN( a, b );
        return packFloat32( zSign, 0, 0 );
    }
    if ( bExp == 0 ) {
        if ( bSig == 0 ) {
            if ( ( aExp | aSig ) == 0 ) {
                float_raise( float_flag_invalid );
                return float32_default_nan;
            }
            float_raise( float_flag_divbyzero );
            return packFloat32( zSign, 0xFF, 0 );
        }
        normalizeFloat32Subnormal( bSig, &bExp, &bSig );
    }
    if ( aExp == 0 ) {
        if ( aSig == 0 ) return packFloat32( zSign, 0, 0 );
        normalizeFloat32Subnormal( aSig, &aExp, &aSig );
    }
    zExp = aExp - bExp + 0x7D;
    aSig = ( aSig | 0x800000 )<<7;
    bSig = ( bSig | 0x800000 )<<8;
    if ( bSig <= ( aSig + aSig ) ) {
        aSig = aSig>>1;
        ++zExp;
    }
    zSig = estimateDiv64To32( aSig, 0, bSig );
    if ( ( zSig & 0x3F ) <= 2 ) {
        mul32To64( bSig, zSig, &term0, &term1 );
        sub64( aSig, 0, term0, term1, &rem0, &rem1 );
        while ( ( (sbits32) rem0 ) < 0 ) {
            --zSig;
            add64( rem0, rem1, 0, bSig, &rem0, &rem1 );
        }
        zSig |= ( 0 < rem1 );
    }
    return roundAndPackFloat32( zSign, zExp, zSig );

}

#if 0 /* unused */
/*
-------------------------------------------------------------------------------
Returns the remainder of the single-precision floating-point value `a'
with respect to the corresponding value `b'.  The operation is performed
according to the IEC/IEEE Standard for Binary Floating-point Arithmetic.
-------------------------------------------------------------------------------
*/
static float32 float32_rem( float32 a, float32 b )
{
    flag aSign, bSign, zSign;
    int16 aExp, bExp, expDiff;
    bits32 aSig, bSig;
    bits32 q, term0, term1, allZero, alternateASig;
    sbits32 sigMean;

    aSig = extractFloat32Frac( a );
    aExp = extractFloat32Exp( a );
    aSign = extractFloat32Sign( a );
    bSig = extractFloat32Frac( b );
    bExp = extractFloat32Exp( b );
    bSign = extractFloat32Sign( b );
    if ( aExp == 0xFF ) {
        if ( aSig || ( ( bExp == 0xFF ) && bSig ) ) {
            return propagateFloat32NaN( a, b );
        }
        float_raise( float_flag_invalid );
        return float32_default_nan;
    }
    if ( bExp == 0xFF ) {
        if ( bSig ) return propagateFloat32NaN( a, b );
        return a;
    }
    if ( bExp == 0 ) {
        if ( bSig == 0 ) {
            float_raise( float_flag_invalid );
            return float32_default_nan;
        }
        normalizeFloat32Subnormal( bSig, &bExp, &bSig );
    }
    if ( aExp == 0 ) {
        if ( aSig == 0 ) return a;
        normalizeFloat32Subnormal( aSig, &aExp, &aSig );
    }
    expDiff = aExp - bExp;
    aSig = ( aSig | 0x800000 )<<8;
    bSig = ( bSig | 0x800000 )<<8;
    if ( expDiff < 0 ) {
        if ( expDiff < -1 ) return a;
        aSig >>= 1;
    }
    q = bSig <= aSig;
    if ( q ) aSig -= bSig;
    expDiff -= 32;
    while ( 0 < expDiff ) {
        q = estimateDiv64To32( aSig, 0, bSig );
        q = ( 2 < q ) ? q - 2 : 0;
        mul32To64( bSig, q, &term0, &term1 );
        shortShiftUp64( term0, term1, 30, &term1, &allZero );
        aSig = ( aSig<<30 ) - term1;
        expDiff -= 30;
    }
    expDiff += 32;
    if ( 0 < expDiff ) {
        q = estimateDiv64To32( aSig, 0, bSig );
        q = ( 2 < q ) ? q - 2 : 0;
        q >>= 32 - expDiff;
        bSig >>= 2;
        mul32To64( bSig, q, &term0, &term1 );
        aSig = ( ( aSig>>1 )<<( expDiff - 1 ) ) - term1;
    }
    else {
        aSig >>= 2;
        bSig >>= 2;
    }
    do {
        alternateASig = aSig;
        ++q;
        aSig -= bSig;
    } while ( 0 <= ( (sbits32) aSig ) );
    sigMean = aSig + alternateASig;
    if ( ( sigMean < 0 ) || ( ( sigMean == 0 ) && ( q & 1 ) ) ) {
        aSig = alternateASig;
    }
    zSign = ( (sbits32) aSig ) < 0;
    if ( zSign ) aSig = - aSig;
    return normalizeRoundAndPackFloat32( aSign ^ zSign, bExp, aSig );

}
#endif /* unused */

#if 0 /* unused */
/*
-------------------------------------------------------------------------------
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.
-------------------------------------------------------------------------------
*/
static float32 float32_sqrt( float32 a )
{
    flag aSign;
    int16 aExp, zExp;
    bits32 aSig, zSig;
    bits32 rem0, rem1;
    bits32 term0, term1;

    aSig = extractFloat32Frac( a );
    aExp = extractFloat32Exp( a );
    aSign = extractFloat32Sign( a );
    if ( aExp == 0xFF ) {
        if ( aSig ) return propagateFloat32NaN( a, 0 );
        if ( aSign == 0 ) return a;
        float_raise( float_flag_invalid );
        return float32_default_nan;
    }
    if ( aSign ) {
        if ( ( aExp | aSig ) == 0 ) return a;
        float_raise( float_flag_invalid );
        return float32_default_nan;
    }
    if ( aExp == 0 ) {
        if ( aSig == 0 ) return 0;
        normalizeFloat32Subnormal( aSig, &aExp, &aSig );
    }
    zExp = ( ( aExp - 0x7F )>>1 ) + 0x7F - 1;
    aSig = ( aSig | 0x800000 )<<8;
    zSig = estimateSqrt32( aExp, aSig );
    zSig = ( 0xFFFFFFFD < zSig ) ? 0xFFFFFFFF : zSig + 2;
    if ( ( zSig & 0x7F ) <= 5 ) {
        aSig = aSig>>( aExp & 1 );
        mul32To64( zSig, zSig, &term0, &term1 );
        sub64( aSig, 0, term0, term1, &rem0, &rem1 );
        while ( ( (sbits32) rem0 ) < 0 ) {
            --zSig;
            shortShiftUp64( 0, zSig, 1, &term0, &term1 );
            term1 |= 1;
            add64( rem0, rem1, term0, term1, &rem0, &rem1 );
        }
        zSig |= ( 0 < ( rem0 | rem1 ) );
    }
    shiftDown32Jamming( zSig, 1, &zSig );
    return roundAndPackFloat32( 0, zExp, zSig );

}
#endif /* unused */

/*
-------------------------------------------------------------------------------
Returns true if the single-precision floating-point value `a' is equal
to the corresponding value `b', and false otherwise.  The comparison is
performed according to the IEC/IEEE Standard for Binary Floating-point
Arithmetic.
-------------------------------------------------------------------------------
*/
flag float32_eq( float32 a, float32 b )
{

    if (    ( ( extractFloat32Exp( a ) == 0xFF ) && extractFloat32Frac( a ) )
         || ( ( extractFloat32Exp( b ) == 0xFF ) && extractFloat32Frac( b ) )
       ) {
        if ( float32_is_signaling_nan( a ) || float32_is_signaling_nan( b ) ) {
            float_raise( float_flag_invalid );
        }
        return 0;
    }
    return ( a == b ) || bothZeroFloat32( a, b );

}

/*
-------------------------------------------------------------------------------
Returns true if the single-precision floating-point value `a' is less
than or equal to the corresponding value `b', and false otherwise.  The
comparison is performed according to the IEC/IEEE Standard for Binary
Floating-point Arithmetic.
-------------------------------------------------------------------------------
*/
flag float32_le( float32 a, float32 b )
{
    flag aSign, bSign;

    if (    ( ( extractFloat32Exp( a ) == 0xFF ) && extractFloat32Frac( a ) )
         || ( ( extractFloat32Exp( b ) == 0xFF ) && extractFloat32Frac( b ) )
       ) {
        float_raise( float_flag_invalid );
        return 0;
    }
    aSign = extractFloat32Sign( a );
    bSign = extractFloat32Sign( b );
    if ( aSign != bSign ) return aSign || bothZeroFloat32( a, b );
    return ( a == b ) || ( aSign ^ ( a < b ) );

}

/*
-------------------------------------------------------------------------------
Returns true if the single-precision floating-point value `a' is less
than the corresponding value `b', and false otherwise.  The comparison is
performed according to the IEC/IEEE Standard for Binary Floating-point
Arithmetic.
-------------------------------------------------------------------------------
*/
flag float32_lt( float32 a, float32 b )
{
    flag aSign, bSign;

    if (    ( ( extractFloat32Exp( a ) == 0xFF ) && extractFloat32Frac( a ) )
         || ( ( extractFloat32Exp( b ) == 0xFF ) && extractFloat32Frac( b ) )
       ) {
        float_raise( float_flag_invalid );
        return 0;
    }
    aSign = extractFloat32Sign( a );
    bSign = extractFloat32Sign( b );
    if ( aSign != bSign ) return aSign && ! bothZeroFloat32( a, b );
    return ( a != b ) && ( aSign ^ ( a < b ) );

}

#if 0 /* unused */
/*
-------------------------------------------------------------------------------
Returns true if the single-precision floating-point value `a' is equal to
the corresponding value `b', and false otherwise.  The invalid exception is
raised if either operand is a NaN.  The comparison is performed according to
the IEC/IEEE Standard for Binary Floating-point Arithmetic.
-------------------------------------------------------------------------------
*/

static flag float32_eq_signaling( float32 a, float32 b )
{

    if (    ( ( extractFloat32Exp( a ) == 0xFF ) && extractFloat32Frac( a ) )
         || ( ( extractFloat32Exp( b ) == 0xFF ) && extractFloat32Frac( b ) )
       ) {
        float_raise( float_flag_invalid );
        return 0;
    }
    return ( a == b ) || bothZeroFloat32( a, b );

}
#endif /* unused */

#if 0 /* unused */
/*
-------------------------------------------------------------------------------
Returns true if the single-precision floating-point value `a' is less than
or equal to the corresponding value `b', and false otherwise.  Quiet NaNs
do not cause an exception.  The comparison is performed according to the
IEC/IEEE Standard for Binary Floating-point Arithmetic.
-------------------------------------------------------------------------------
*/
static flag float32_le_quiet( float32 a, float32 b )
{
    flag aSign, bSign;
/*    int16 aExp, bExp;*/

    if (    ( ( extractFloat32Exp( a ) == 0xFF ) && extractFloat32Frac( a ) )
         || ( ( extractFloat32Exp( b ) == 0xFF ) && extractFloat32Frac( b ) )
       ) {
        if ( float32_is_signaling_nan( a ) || float32_is_signaling_nan( b ) ) {
            float_raise( float_flag_invalid );
        }
        return 0;
    }
    aSign = extractFloat32Sign( a );
    bSign = extractFloat32Sign( b );
    if ( aSign != bSign ) return aSign || bothZeroFloat32( a, b );
    return ( a == b ) || ( aSign ^ ( a < b ) );

}
#endif /* unused */

#if 0 /* unused */
/*
-------------------------------------------------------------------------------
Returns true if the single-precision floating-point value `a' is less than
the corresponding value `b', and false otherwise.  Quiet NaNs do not cause
an exception.  The comparison is performed according to the IEC/IEEE
Standard for Binary Floating-point Arithmetic.
-------------------------------------------------------------------------------
*/
static flag float32_lt_quiet( float32 a, float32 b )
{
    flag aSign, bSign;

    if (    ( ( extractFloat32Exp( a ) == 0xFF ) && extractFloat32Frac( a ) )
         || ( ( extractFloat32Exp( b ) == 0xFF ) && extractFloat32Frac( b ) )
       ) {
        if ( float32_is_signaling_nan( a ) || float32_is_signaling_nan( b ) ) {
            float_raise( float_flag_invalid );
        }
        return 0;
    }
    aSign = extractFloat32Sign( a );
    bSign = extractFloat32Sign( b );
    if ( aSign != bSign ) return aSign && ! bothZeroFloat32( a, b );
    return ( a != b ) && ( aSign ^ ( a < b ) );

}
#endif /* unused */

#if 0 /* unused */
/*
-------------------------------------------------------------------------------
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.
-------------------------------------------------------------------------------
*/
static float64 float64_round_to_int( float64 a )
{
    flag aSign;
    int16 aExp;
    uint32 lastBitMask, roundBitsMask;
    uint8 roundingMode;
    float64 z;

    aExp = extractFloat64Exp( a );
    if ( 0x413 <= aExp ) {
        if ( 0x433 <= aExp ) {
            if (    ( aExp == 0x7FF )
                 && ( extractFloat64Frac0( a ) | extractFloat64Frac1( a ) ) ) {
                return propagateFloat64NaN( a, a );
            }
            return a;
        }
        lastBitMask = ( 1<<( 0x432 - aExp ) )<<1;
        roundBitsMask = lastBitMask - 1;
        z = a;
        roundingMode = float_rounding_mode;
        if ( roundingMode == float_round_nearest_even ) {
            if ( lastBitMask ) {
                add64( z.high, z.low, 0, lastBitMask>>1, &z.high, &z.low );
                if ( ( z.low & roundBitsMask ) == 0 ) z.low &= ~ lastBitMask;
            }
            else {
                if ( ( (sbits32) z.low ) < 0 ) {
                    ++z.high;
                    if ( ( z.low<<1 ) == 0 ) z.high &= ~1;
                }
            }
        }
        else if ( roundingMode != float_round_to_zero ) {
            if (   extractFloat64Sign( z )
                 ^ ( roundingMode == float_round_up ) ) {
                add64( z.high, z.low, 0, roundBitsMask, &z.high, &z.low );
            }
        }
        z.low &= ~ roundBitsMask;
    }
    else {
        if ( aExp <= 0x3FE ) {
            if ( ( ( a.high<<1 ) | a.low ) == 0 ) return a;
            float_exception_flags |= float_flag_inexact;
            aSign = extractFloat64Sign( a );
            switch ( float_rounding_mode ) {
                case float_round_nearest_even:
                    if (    ( aExp == 0x3FE )
                         && (   extractFloat64Frac0( a )
                              | extractFloat64Frac1( a ) )
                       ) {
                        return packFloat64( aSign, 0x3FF, 0, 0 );
                    }
                    break;
                case float_round_down:
                    return
                          aSign ? packFloat64( 1, 0x3FF, 0, 0 )
                        : packFloat64( 0, 0, 0, 0 );
                case float_round_up:
                    return
                          aSign ? packFloat64( 1, 0, 0, 0 )
                        : packFloat64( 0, 0x3FF, 0, 0 );
            }
            return packFloat64( aSign, 0, 0, 0 );
        }
        lastBitMask = 1<<( 0x413 - aExp );
        roundBitsMask = lastBitMask - 1;
        z.low = 0;
        z.high = a.high;
        roundingMode = float_rounding_mode;
        if ( roundingMode == float_round_nearest_even ) {
            z.high += lastBitMask>>1;
            if ( ( ( z.high & roundBitsMask ) | a.low ) == 0 ) {
                z.high &= ~ lastBitMask;
            }
        }
        else if ( roundingMode != float_round_to_zero ) {
            if (   extractFloat64Sign( z )
                 ^ ( roundingMode == float_round_up ) ) {
                z.high |= ( a.low != 0 );
                z.high += roundBitsMask;
            }
        }
        z.high &= ~ roundBitsMask;
    }
    if ( ( z.low != a.low ) || ( z.high != a.high ) ) {
        float_exception_flags |= float_flag_inexact;
    }
    return z;

}
#endif /* unused */

/*
-------------------------------------------------------------------------------
Returns the result of adding the absolute values of the double-precision
floating-point values `a' and `b'.  If `zSign' is true, 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, flag zSign )
{
    int16 aExp, bExp, zExp;
    bits32 aSig0, aSig1, bSig0, bSig1, zSig0, zSig1, zSig2;
    int16 expDiff;

    aSig1 = extractFloat64Frac1( a );
    aSig0 = extractFloat64Frac0( a );
    aExp = extractFloat64Exp( a );
    bSig1 = extractFloat64Frac1( b );
    bSig0 = extractFloat64Frac0( b );
    bExp = extractFloat64Exp( b );
    expDiff = aExp - bExp;
    if ( 0 < expDiff ) {
        if ( aExp == 0x7FF ) {
            if ( aSig0 | aSig1 ) return propagateFloat64NaN( a, b );
            return a;
        }
        if ( bExp == 0 ) {
            --expDiff;
        }
        else {
            bSig0 |= 0x100000;
        }
        shiftDown64ExtraJamming(
            bSig0, bSig1, 0, expDiff, &bSig0, &bSig1, &zSig2 );
        zExp = aExp;
    }
    else if ( expDiff < 0 ) {
        if ( bExp == 0x7FF ) {
            if ( bSig0 | bSig1 ) return propagateFloat64NaN( a, b );
            return packFloat64( zSign, 0x7FF, 0, 0 );
        }
        if ( aExp == 0 ) {
            ++expDiff;
        }
        else {
            aSig0 |= 0x100000;
        }
        shiftDown64ExtraJamming(
            aSig0, aSig1, 0, - expDiff, &aSig0, &aSig1, &zSig2 );
        zExp = bExp;
    }
    else {
        if ( aExp == 0x7FF ) {
            if ( aSig0 | aSig1 | bSig0 | bSig1 ) {
                return propagateFloat64NaN( a, b );
            }
            return a;
        }
        add64( aSig0, aSig1, bSig0, bSig1, &zSig0, &zSig1 );
        if ( aExp == 0 ) return packFloat64( zSign, 0, zSig0, zSig1 );
        zSig2 = 0;
        zSig0 |= 0x200000;
        zExp = aExp;
        goto shiftDown1;
    }
    aSig0 |= 0x100000;
    add64( aSig0, aSig1, bSig0, bSig1, &zSig0, &zSig1 );
    --zExp;
    if ( zSig0 < 0x200000 ) goto roundAndPack;
    ++zExp;
  shiftDown1:
    shiftDown64ExtraJamming( zSig0, zSig1, zSig2, 1, &zSig0, &zSig1, &zSig2 );
  roundAndPack:
    return roundAndPackFloat64( zSign, zExp, zSig0, zSig1, zSig2 );

}

/*
-------------------------------------------------------------------------------
Returns the result of subtracting the absolute values of the double-
precision floating-point values `a' and `b'.  If `zSign' is true, 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, flag zSign )
{
    int16 aExp, bExp, zExp;
    bits32 aSig0, aSig1, bSig0, bSig1, zSig0, zSig1;
    int16 expDiff;
    float64 z;

    aSig1 = extractFloat64Frac1( a );
    aSig0 = extractFloat64Frac0( a );
    aExp = extractFloat64Exp( a );
    bSig1 = extractFloat64Frac1( b );
    bSig0 = extractFloat64Frac0( b );
    bExp = extractFloat64Exp( b );
    expDiff = aExp - bExp;
    shortShiftUp64( aSig0, aSig1, 10, &aSig0, &aSig1 );
    shortShiftUp64( bSig0, bSig1, 10, &bSig0, &bSig1 );
    if ( 0 < expDiff ) goto aExpBigger;
    if ( expDiff < 0 ) goto bExpBigger;
    if ( aExp == 0x7FF ) {
        if ( aSig0 | aSig1 | bSig0 | bSig1 ) {
            return propagateFloat64NaN( a, b );
        }
        float_raise( float_flag_invalid );
        z.low = float64_default_nan_low;
        z.high = float64_default_nan_high;
        return z;
    }
    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 packFloat64( float_rounding_mode == float_round_down, 0, 0, 0 );
  bExpBigger:
    if ( bExp == 0x7FF ) {
        if ( bSig0 | bSig1 ) return propagateFloat64NaN( a, b );
        return packFloat64( zSign ^ 1, 0x7FF, 0, 0 );
    }
    if ( aExp == 0 ) {
        ++expDiff;
    }
    else {
        aSig0 |= 0x40000000;
    }
    shiftDown64Jamming( aSig0, aSig1, - expDiff, &aSig0, &aSig1 );
    bSig0 |= 0x40000000;
  bBigger:
    sub64( bSig0, bSig1, aSig0, aSig1, &zSig0, &zSig1 );
    zExp = bExp;
    zSign ^= 1;
    goto normalizeRoundAndPack;
  aExpBigger:
    if ( aExp == 0x7FF ) {
        if ( aSig0 | aSig1 ) return propagateFloat64NaN( a, b );
        return a;
    }
    if ( bExp == 0 ) {
        --expDiff;
    }
    else {
        bSig0 |= 0x40000000;
    }
    shiftDown64Jamming( bSig0, bSig1, expDiff, &bSig0, &bSig1 );
    aSig0 |= 0x40000000;
  aBigger:
    sub64( aSig0, aSig1, bSig0, bSig1, &zSig0, &zSig1 );
    zExp = aExp;
  normalizeRoundAndPack:
    --zExp;
    return normalizeRoundAndPackFloat64( zSign, zExp - 10, zSig0, zSig1 );

}

/*
-------------------------------------------------------------------------------
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 )
{
    flag aSign, bSign;

    aSign = extractFloat64Sign( a );
    bSign = extractFloat64Sign( b );
    if ( aSign == bSign ) {
        return addFloat64Sigs( a, b, aSign );
    }
    else {
        return subFloat64Sigs( a, b, aSign );
    }

}

/*
-------------------------------------------------------------------------------
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 )
{
    flag aSign, bSign;

    aSign = extractFloat64Sign( a );
    bSign = extractFloat64Sign( b );
    if ( aSign == bSign ) {
        return subFloat64Sigs( a, b, aSign );
    }
    else {
        return addFloat64Sigs( a, b, aSign );
    }

}

/*
-------------------------------------------------------------------------------
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.  The underflow exception is raised
only if the result is a subnormal.
-------------------------------------------------------------------------------
*/
float64 float64_mul( float64 a, float64 b )
{
    flag aSign, bSign, zSign;
    int16 aExp, bExp, zExp;
    bits32 aSig0, aSig1, bSig0, bSig1, zSig0, zSig1, zSig2, zSig3;
    float64 z;

    aSig1 = extractFloat64Frac1( a );
    aSig0 = extractFloat64Frac0( a );
    aExp = extractFloat64Exp( a );
    aSign = extractFloat64Sign( a );
    bSig1 = extractFloat64Frac1( b );
    bSig0 = extractFloat64Frac0( b );
    bExp = extractFloat64Exp( b );
    bSign = extractFloat64Sign( b );
    zSign = aSign ^ bSign;
    if ( aExp == 0x7FF ) {
        if (    ( aSig0 | aSig1 )
             || ( ( bExp == 0x7FF ) && ( bSig0 | bSig1 ) ) ) {
            return propagateFloat64NaN( a, b );
        }
        if ( ( bExp | bSig0 | bSig1 ) == 0 ) goto invalid;
        return packFloat64( zSign, 0x7FF, 0, 0 );
    }
    if ( bExp == 0x7FF ) {
        if ( bSig0 | bSig1 ) return propagateFloat64NaN( a, b );
        if ( ( aExp | aSig0 | aSig1 ) == 0 ) {
  invalid:
            float_raise( float_flag_invalid );
            z.low = float64_default_nan_low;
            z.high = float64_default_nan_high;
            return z;
        }
        return packFloat64( zSign, 0x7FF, 0, 0 );
    }
    if ( aExp == 0 ) {
        if ( ( aSig0 | aSig1 ) == 0 ) return packFloat64( zSign, 0, 0, 0 );
        normalizeFloat64Subnormal( aSig0, aSig1, &aExp, &aSig0, &aSig1 );
    }
    if ( bExp == 0 ) {
        if ( ( bSig0 | bSig1 ) == 0 ) return packFloat64( zSign, 0, 0, 0 );
        normalizeFloat64Subnormal( bSig0, bSig1, &bExp, &bSig0, &bSig1 );
    }
    zExp = aExp + bExp - 0x3FF - 1;
    aSig0 |= 0x100000;
    shortShiftUp64( bSig0, bSig1, 12, &bSig0, &bSig1 );
    mul64To128( aSig0, aSig1, bSig0, bSig1, &zSig0, &zSig1, &zSig2, &zSig3 );
    add64( zSig0, zSig1, aSig0, aSig1, &zSig0, &zSig1 );
    zSig2 |= ( 0 < zSig3 );
    if ( 0x200000 <= zSig0 ) {
        shiftDown64ExtraJamming(
            zSig0, zSig1, zSig2, 1, &zSig0, &zSig1, &zSig2 );
        ++zExp;
    }
    return roundAndPackFloat64( zSign, zExp, zSig0, zSig1, zSig2 );

}

/*
-------------------------------------------------------------------------------
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.  The underflow
exception is raised only if the result is a subnormal.
-------------------------------------------------------------------------------
*/
float64 float64_div( float64 a, float64 b )
{
    flag aSign, bSign, zSign;
    int16 aExp, bExp, zExp;
    bits32 aSig0, aSig1, bSig0, bSig1, zSig0, zSig1, zSig2;
    bits32 rem0, rem1, rem2, rem3;
    bits32 term0, term1, term2, term3;
    float64 z;

    aSig1 = extractFloat64Frac1( a );
    aSig0 = extractFloat64Frac0( a );
    aExp = extractFloat64Exp( a );
    aSign = extractFloat64Sign( a );
    bSig1 = extractFloat64Frac1( b );
    bSig0 = extractFloat64Frac0( b );
    bExp = extractFloat64Exp( b );
    bSign = extractFloat64Sign( b );
    zSign = aSign ^ bSign;
    if ( aExp == 0x7FF ) {
        if ( aSig0 | aSig1 ) return propagateFloat64NaN( a, b );
        if ( bExp == 0x7FF ) {
            if ( bSig0 | bSig1 ) return propagateFloat64NaN( a, b );
            goto invalid;
        }
        return packFloat64( zSign, 0x7FF, 0, 0 );
    }
    if ( bExp == 0x7FF ) {
        if ( bSig0 | bSig1 ) return propagateFloat64NaN( a, b );
        return packFloat64( zSign, 0, 0, 0 );
    }
    if ( bExp == 0 ) {
        if ( ( bSig0 | bSig1 ) == 0 ) {
            if ( ( aExp | aSig0 | aSig1 ) == 0 ) {
  invalid:
                float_raise( float_flag_invalid );
                z.low = float64_default_nan_low;
                z.high = float64_default_nan_high;
                return z;
            }
            float_raise( float_flag_divbyzero );
            return packFloat64( zSign, 0x7FF, 0, 0 );
        }
        normalizeFloat64Subnormal( bSig0, bSig1, &bExp, &bSig0, &bSig1 );
    }
    if ( aExp == 0 ) {
        if ( ( aSig0 | aSig1 ) == 0 ) return packFloat64( zSign, 0, 0, 0 );
        normalizeFloat64Subnormal( aSig0, aSig1, &aExp, &aSig0, &aSig1 );
    }
    zExp = aExp - bExp + 0x3FE - 1;
    shortShiftUp64( aSig0 | 0x100000, aSig1, 11, &aSig0, &aSig1 );
    shortShiftUp64( bSig0 | 0x100000, bSig1, 11, &bSig0, &bSig1 );
    if ( le64( bSig0, bSig1, aSig0, aSig1 ) ) {
        shiftDown64( aSig0, aSig1, 1, &aSig0, &aSig1 );
        ++zExp;
    }
    zSig0 = estimateDiv64To32( aSig0, aSig1, bSig0 );
    mul64By32To96( bSig0, bSig1, zSig0, &term0, &term1, &term2 );
    sub96( aSig0, aSig1, 0, term0, term1, term2, &rem0, &rem1, &rem2 );
    while ( ( (sbits32) rem0 ) < 0 ) {
        --zSig0;
        add96( rem0, rem1, rem2, 0, bSig0, bSig1, &rem0, &rem1, &rem2 );
    }
    zSig1 = estimateDiv64To32( rem1, rem2, bSig0 );
    if ( ( zSig1 & 0x3FF ) <= 4 ) {
        mul64By32To96( bSig0, bSig1, zSig1, &term1, &term2, &term3 );
        sub96( rem1, rem2, 0, term1, term2, term3, &rem1, &rem2, &rem3 );
        while ( ( (sbits32) rem1 ) < 0 ) {
            --zSig1;
            add96( rem1, rem2, rem3, 0, bSig0, bSig1, &rem1, &rem2, &rem3 );
        }
        zSig1 |= ( 0 < ( rem1 | rem2 | rem3 ) );
    }
    shiftDown64ExtraJamming( zSig0, zSig1, 0, 11, &zSig0, &zSig1, &zSig2 );
    return roundAndPackFloat64( zSign, zExp, zSig0, zSig1, zSig2 );

}

#if 0 /* unused */
/*
-------------------------------------------------------------------------------
Returns the remainder of the double-precision floating-point value `a'
with respect to the corresponding value `b'.  The operation is performed
according to the IEC/IEEE Standard for Binary Floating-point Arithmetic.
-------------------------------------------------------------------------------
*/
static float64 float64_rem( float64 a, float64 b )
{
    flag aSign, bSign, zSign;
    int16 aExp, bExp, expDiff;
    bits32 aSig0, aSig1, bSig0, bSig1;
    bits32 q, term0, term1, term2, allZero, alternateASig0, alternateASig1;
    bits32 sigMean1;
    sbits32 sigMean0;
    float64 z;

    aSig1 = extractFloat64Frac1( a );
    aSig0 = extractFloat64Frac0( a );
    aExp = extractFloat64Exp( a );
    aSign = extractFloat64Sign( a );
    bSig1 = extractFloat64Frac1( b );
    bSig0 = extractFloat64Frac0( b );
    bExp = extractFloat64Exp( b );
    bSign = extractFloat64Sign( b );
    if ( aExp == 0x7FF ) {
        if (    ( aSig0 | aSig1 )
             || ( ( bExp == 0x7FF ) && ( bSig0 | bSig1 ) ) ) {
            return propagateFloat64NaN( a, b );
        }
        goto invalid;
    }
    if ( bExp == 0x7FF ) {
        if ( bSig0 | bSig1 ) return propagateFloat64NaN( a, b );
        return a;
    }
    if ( bExp == 0 ) {
        if ( ( bSig0 | bSig1 ) == 0 ) {
  invalid:
            float_raise( float_flag_invalid );
            z.low = float64_default_nan_low;
            z.high = float64_default_nan_high;
            return z;
        }
        normalizeFloat64Subnormal( bSig0, bSig1, &bExp, &bSig0, &bSig1 );
    }
    if ( aExp == 0 ) {
        if ( ( aSig0 | aSig1 ) == 0 ) return a;
        normalizeFloat64Subnormal( aSig0, aSig1, &aExp, &aSig0, &aSig1 );
    }
    expDiff = aExp - bExp;
    if ( expDiff < -1 ) return a;
    shortShiftUp64(
        aSig0 | 0x100000, aSig1, 11 - ( expDiff < 0 ), &aSig0, &aSig1 );
    shortShiftUp64( bSig0 | 0x100000, bSig1, 11, &bSig0, &bSig1 );
    q = le64( bSig0, bSig1, aSig0, aSig1 );
    if ( q ) sub64( aSig0, aSig1, bSig0, bSig1, &aSig0, &aSig1 );
    expDiff -= 32;
    while ( 0 < expDiff ) {
        q = estimateDiv64To32( aSig0, aSig1, bSig0 );
        q = ( 4 < q ) ? q - 4 : 0;
        mul64By32To96( bSig0, bSig1, q, &term0, &term1, &term2 );
        shortShiftUp96( term0, term1, term2, 29, &term1, &term2, &allZero );
        shortShiftUp64( aSig0, aSig1, 29, &aSig0, &allZero );
        sub64( aSig0, 0, term1, term2, &aSig0, &aSig1 );
        expDiff -= 29;
    }
    if ( -32 < expDiff ) {
        q = estimateDiv64To32( aSig0, aSig1, bSig0 );
        q = ( 4 < q ) ? q - 4 : 0;
        q >>= - expDiff;
        shiftDown64( bSig0, bSig1, 8, &bSig0, &bSig1 );
        expDiff += 24;
        if ( expDiff < 0 ) {
            shiftDown64( aSig0, aSig1, - expDiff, &aSig0, &aSig1 );
        }
        else {
            shortShiftUp64( aSig0, aSig1, expDiff, &aSig0, &aSig1 );
        }
        mul64By32To96( bSig0, bSig1, q, &term0, &term1, &term2 );
        sub64( aSig0, aSig1, term1, term2, &aSig0, &aSig1 );
    }
    else {
        shiftDown64( aSig0, aSig1, 8, &aSig0, &aSig1 );
        shiftDown64( bSig0, bSig1, 8, &bSig0, &bSig1 );
    }
    do {
        alternateASig0 = aSig0;
        alternateASig1 = aSig1;
        ++q;
        sub64( aSig0, aSig1, bSig0, bSig1, &aSig0, &aSig1 );
    } while ( 0 <= ( (sbits32) aSig0 ) );
    add64(
        aSig0, aSig1, alternateASig0, alternateASig1, &sigMean0, &sigMean1 );
    if (    ( sigMean0 < 0 )
         || ( ( ( sigMean0 | sigMean1 ) == 0 ) && ( q & 1 ) ) ) {
        aSig0 = alternateASig0;
        aSig1 = alternateASig1;
    }
    zSign = ( (sbits32) aSig0 ) < 0;
    if ( zSign ) sub64( 0, 0, aSig0, aSig1, &aSig0, &aSig1 );
    return
        normalizeRoundAndPackFloat64( aSign ^ zSign, bExp - 4, aSig0, aSig1 );

}
#endif /* unused */

#if 0 /* unused */
/*
-------------------------------------------------------------------------------
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.
-------------------------------------------------------------------------------
*/
static float64 float64_sqrt( float64 a )
{
    flag aSign;
    int16 aExp, zExp;
    bits32 aSig0, aSig1, zSig0, zSig1, zSig2;
    bits32 rem0, rem1, rem2, rem3;
    bits32 term0, term1, term2, term3;
    bits32 shiftedRem0, shiftedRem1;
    float64 z;

    aSig1 = extractFloat64Frac1( a );
    aSig0 = extractFloat64Frac0( a );
    aExp = extractFloat64Exp( a );
    aSign = extractFloat64Sign( a );
    if ( aExp == 0x7FF ) {
        if ( aSig0 | aSig1 ) return propagateFloat64NaN( a, a );
        if ( aSign == 0 ) return a;
        goto invalid;
    }
    if ( aSign ) {
        if ( ( aExp | aSig0 | aSig1 ) == 0 ) return a;
  invalid:
        float_raise( float_flag_invalid );
        z.low = float64_default_nan_low;
        z.high = float64_default_nan_high;
        return z;
    }
    if ( aExp == 0 ) {
        if ( ( aSig0 | aSig1 ) == 0 ) return packFloat64( 0, 0, 0, 0 );
        normalizeFloat64Subnormal( aSig0, aSig1, &aExp, &aSig0, &aSig1 );
    }
    zExp = ( ( aExp - 0x3FF )>>1 ) + 0x3FF - 1;
    shortShiftUp64( aSig0 | 0x100000, aSig1, 11, &aSig0, &aSig1 );
    zSig0 = estimateSqrt32( aExp, aSig0 );
    zSig0 = ( 0xFFFFFFFD < zSig0 ) ? 0xFFFFFFFF : zSig0 + 2;
    if ( aExp & 1 ) shiftDown64( aSig0, aSig1, 1, &aSig0, &aSig1 );
    mul32To64( zSig0, zSig0, &term0, &term1 );
    sub64( aSig0, aSig1, term0, term1, &rem0, &rem1 );
    while ( ( (sbits32) rem0 ) < 0 ) {
        --zSig0;
        shortShiftUp64( 0, zSig0, 1, &term0, &term1 );
        term1 |= 1;
        add64( rem0, rem1, term0, term1, &rem0, &rem1 );
    }
    shortShiftUp64( rem0, rem1, 31, &shiftedRem0, &shiftedRem1 );
    zSig1 = estimateDiv64To32( shiftedRem0, shiftedRem1, zSig0 );
    if ( ( zSig1 & 0x3FF ) <= 5 ) {
        if ( zSig1 == 0 ) zSig1 = 1;
        mul32To64( zSig0, zSig1, &term1, &term2 );
        shortShiftUp64( term1, term2, 1, &term1, &term2 );
        sub64( rem1, 0, term1, term2, &rem1, &rem2 );
        mul32To64( zSig1, zSig1, &term2, &term3 );
        sub96( rem1, rem2, 0, 0, term2, term3, &rem1, &rem2, &rem3 );
        while ( ( (sbits32) rem1 ) < 0 ) {
            --zSig1;
            shortShiftUp96( 0, zSig0, zSig1, 1, &term1, &term2, &term3 );
            term3 |= 1;
            add96( rem1, rem2, rem3, term1, term2, term3,
                   &rem1, &rem2, &rem3 );
        }
        zSig1 |= ( 0 < ( rem1 | rem2 | rem3 ) );
    }
    shiftDown64ExtraJamming( zSig0, zSig1, 0, 11, &zSig0, &zSig1, &zSig2 );
    return roundAndPackFloat64( 0, zExp, zSig0, zSig1, zSig2 );

}
#endif /* unused */

/*
-------------------------------------------------------------------------------
Returns true if the double-precision floating-point value `a' is equal
to the corresponding value `b', and false otherwise.  The comparison is
performed according to the IEC/IEEE Standard for Binary Floating-point
Arithmetic.
-------------------------------------------------------------------------------
*/
flag float64_eq( float64 a, float64 b )
{

    if (    (    ( extractFloat64Exp( a ) == 0x7FF )
              && ( extractFloat64Frac0( a ) | extractFloat64Frac1( a ) ) )
         || (    ( extractFloat64Exp( b ) == 0x7FF )
              && ( extractFloat64Frac0( b ) | extractFloat64Frac1( b ) ) )
       ) {
        if ( float64_is_signaling_nan( a ) || float64_is_signaling_nan( b ) ) {
            float_raise( float_flag_invalid );
        }
        return 0;
    }
    return
           ( a.low == b.low )
        && ( ( a.high == b.high ) || bothZeroFloat64( a, b ) );

}

/*
-------------------------------------------------------------------------------
Returns true if the double-precision floating-point value `a' is less
than or equal to the corresponding value `b', and false otherwise.  The
comparison is performed according to the IEC/IEEE Standard for Binary
Floating-point Arithmetic.
-------------------------------------------------------------------------------
*/
flag float64_le( float64 a, float64 b )
{
    bits32 a0, a1, b0, b1;
    flag aSign, bSign;

    if (    (    ( extractFloat64Exp( a ) == 0x7FF )
              && ( extractFloat64Frac0( a ) | extractFloat64Frac1( a ) ) )
         || (    ( extractFloat64Exp( b ) == 0x7FF )
              && ( extractFloat64Frac0( b ) | extractFloat64Frac1( b ) ) )
       ) {
        float_raise( float_flag_invalid );
        return 0;
    }
    a1 = a.low;
    a0 = a.high;
    aSign = extractFloat64Sign( a );
    b1 = b.low;
    b0 = b.high;
    bSign = extractFloat64Sign( b );
    if ( aSign != bSign ) return aSign || bothZeroFloat64( a, b );
    return aSign ? le64( b0, b1, a0, a1 ) : le64( a0, a1, b0, b1 );

}

/*
-------------------------------------------------------------------------------
Returns true if the double-precision floating-point value `a' is less
than the corresponding value `b', and false otherwise.  The comparison is
performed according to the IEC/IEEE Standard for Binary Floating-point
Arithmetic.
-------------------------------------------------------------------------------
*/
flag float64_lt( float64 a, float64 b )
{
    bits32 a0, a1, b0, b1;
    flag aSign, bSign;

    if (    (    ( extractFloat64Exp( a ) == 0x7FF )
              && ( extractFloat64Frac0( a ) | extractFloat64Frac1( a ) ) )
         || (    ( extractFloat64Exp( b ) == 0x7FF )
              && ( extractFloat64Frac0( b ) | extractFloat64Frac1( b ) ) )
       ) {
        float_raise( float_flag_invalid );
        return 0;
    }
    a1 = a.low;
    a0 = a.high;
    aSign = extractFloat64Sign( a );
    b1 = b.low;
    b0 = b.high;
    bSign = extractFloat64Sign( b );
    if ( aSign != bSign ) return aSign && ! bothZeroFloat64( a, b );
    return aSign ? lt64( b0, b1, a0, a1 ) : lt64( a0, a1, b0, b1 );

}

#if 0 /* unused */
/*
-------------------------------------------------------------------------------
Returns true if the double-precision floating-point value `a' is equal to
the corresponding value `b', and false otherwise.  The invalid exception is
raised if either operand is a NaN.  The comparison is performed according to
the IEC/IEEE Standard for Binary Floating-point Arithmetic.
-------------------------------------------------------------------------------
*/
static flag float64_eq_signaling( float64 a, float64 b )
{

    if (    (    ( extractFloat64Exp( a ) == 0x7FF )
              && ( extractFloat64Frac0( a ) | extractFloat64Frac1( a ) ) )
         || (    ( extractFloat64Exp( b ) == 0x7FF )
              && ( extractFloat64Frac0( b ) | extractFloat64Frac1( b ) ) )
       ) {
        float_raise( float_flag_invalid );
        return 0;
    }
    return
           ( a.low == b.low )
        && ( ( a.high == b.high ) || bothZeroFloat64( a, b ) );

}
#endif /* unused */

#if 0 /* unused */
/*
-------------------------------------------------------------------------------
Returns true if the double-precision floating-point value `a' is less than
or equal to the corresponding value `b', and false otherwise.  Quiet NaNs
do not cause an exception.  The comparison is performed according to the
IEC/IEEE Standard for Binary Floating-point Arithmetic.
-------------------------------------------------------------------------------
*/
static flag float64_le_quiet( float64 a, float64 b )
{
    bits32 a0, a1, b0, b1;
    flag aSign, bSign;

    if (    (    ( extractFloat64Exp( a ) == 0x7FF )
              && ( extractFloat64Frac0( a ) | extractFloat64Frac1( a ) ) )
         || (    ( extractFloat64Exp( b ) == 0x7FF )
              && ( extractFloat64Frac0( b ) | extractFloat64Frac1( b ) ) )
       ) {
        if ( float64_is_signaling_nan( a ) || float64_is_signaling_nan( b ) ) {
            float_raise( float_flag_invalid );
        }
        return 0;
    }
    a1 = a.low;
    a0 = a.high;
    aSign = extractFloat64Sign( a );
    b1 = b.low;
    b0 = b.high;
    bSign = extractFloat64Sign( b );
    if ( aSign != bSign ) return aSign || bothZeroFloat64( a, b );
    return aSign ? le64( b0, b1, a0, a1 ) : le64( a0, a1, b0, b1 );

}
#endif /* unused */

#if 0 /* unused */
/*
-------------------------------------------------------------------------------
Returns true if the double-precision floating-point value `a' is less than
the corresponding value `b', and false otherwise.  Quiet NaNs do not cause
an exception.  The comparison is performed according to the IEC/IEEE
Standard for Binary Floating-point Arithmetic.
-------------------------------------------------------------------------------
*/
static flag float64_lt_quiet( float64 a, float64 b )
{
    bits32 a0, a1, b0, b1;
    flag aSign, bSign;

    if (    (    ( extractFloat64Exp( a ) == 0x7FF )
              && ( extractFloat64Frac0( a ) | extractFloat64Frac1( a ) ) )
         || (    ( extractFloat64Exp( b ) == 0x7FF )
              && ( extractFloat64Frac0( b ) | extractFloat64Frac1( b ) ) )
       ) {
        if ( float64_is_signaling_nan( a ) || float64_is_signaling_nan( b ) ) {
            float_raise( float_flag_invalid );
        }
        return 0;
    }
    a1 = a.low;
    a0 = a.high;
    aSign = extractFloat64Sign( a );
    b1 = b.low;
    b0 = b.high;
    bSign = extractFloat64Sign( b );
    if ( aSign != bSign ) return aSign && ! bothZeroFloat64( a, b );
    return aSign ? lt64( b0, b1, a0, a1 ) : lt64( a0, a1, b0, b1 );

}
#endif /* unused */


/*
 * These two routines are not part of the original softfloat distribution.
 *
 * They are based on the corresponding conversions to integer but return
 * unsigned numbers instead since these functions are required by GCC.
 *
 * Added by Mark Brinicombe <mark@netbsd.org>	27/09/97
 */


/*
-------------------------------------------------------------------------------
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, the largest positive integer is returned.  If the conversion
overflows, the largest integer positive is returned.
-------------------------------------------------------------------------------
*/
uint32 float64_to_uint32_round_to_zero( float64 a )
{
    flag aSign;
    int16 aExp, shiftCount;
    bits32 aSig0, aSig1;
    bits32 absZ, zExtra;
    uint32 z;
/*    uint8 roundingMode;*/

    aSig1 = extractFloat64Frac1( a );
    aSig0 = extractFloat64Frac0( a );
    aExp = extractFloat64Exp( a );
    aSign = extractFloat64Sign( a );

    if (aSign) {
        float_raise( float_flag_invalid );
    	return(0);
    }

    shiftCount = aExp - 0x413;
    if ( 0 <= shiftCount ) {
        if ( 11 < shiftCount ) {
            absZ = 0xFFFFFFFF;
        }
        else {
            shortShiftUp64(
                aSig0 | 0x100000, aSig1, shiftCount, &absZ, &zExtra );
        }
    }
    else {
        if ( aExp < 0x3FE ) {
            zExtra = aExp | aSig0 | aSig1;
            absZ = 0;
        }
        else {
            aSig0 |= 0x100000;
            zExtra = ( aSig0<<( shiftCount & 31 ) ) | aSig1;
            absZ = aSig0>>( - shiftCount );
        }
    }
    z = absZ;
    if ( zExtra ) float_exception_flags |= float_flag_inexact;
    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, the largest positive integer is returned.  If the conversion
overflows, the largest positive integer is returned.
-------------------------------------------------------------------------------
*/
uint32 float32_to_uint32_round_to_zero( float32 a )
{
    flag aSign;
    int16 aExp, shiftCount;
    bits32 aSig;
    uint32 z;

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

    if (aSign) {
        float_raise( float_flag_invalid );
    	return(0);
    }
    if ( 0 < shiftCount ) {
        float_raise( float_flag_invalid );
        return 0xFFFFFFFF;
    }
    else if ( aExp <= 0x7E ) {
        if ( aExp | aSig ) float_exception_flags |= float_flag_inexact;
        return 0;
    }
    aSig = ( aSig | 0x800000 )<<8;
    z = aSig>>( - shiftCount );
    if ( aSig<<( shiftCount & 31 ) ) {
        float_exception_flags |= float_flag_inexact;
    }
    return z;

}