/* THIS FILE HAS BEEN MODIFIED FOR USE WITH THE HERCULES PROJECT */
/*============================================================================

This C source fragment 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.

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

/*----------------------------------------------------------------------------
| Underflow tininess-detection mode, statically initialized to default value.
| (The declaration in `softfloat.h' must match the `int8' type here.)
*----------------------------------------------------------------------------*/
int8 float_detect_tininess = float_tininess_before_rounding;

/*----------------------------------------------------------------------------
| Sets the floating-point rounding mode.
*----------------------------------------------------------------------------*/

void float_set_rounding_mode( int8 mode )
{

    float_rounding_mode = mode;

}

/*----------------------------------------------------------------------------
| Gets the floating-point exception flags.
*----------------------------------------------------------------------------*/

int8 float_get_exception_flags()
{

    return float_exception_flags;

}

/*----------------------------------------------------------------------------
| Clears the floating-point exception flags.
*----------------------------------------------------------------------------*/

void float_clear_exception_flags()
{

    float_exception_flags = 0;

}

/*----------------------------------------------------------------------------
| Raises the exceptions specified by `flags'.  Floating-point traps can be
| defined here if desired.  It is currently not possible for such a trap to
| substitute a result value.  If traps are not implemented, this routine
| should be simply `float_exception_flags |= flags;'.
*----------------------------------------------------------------------------*/

void float_raise( int8 flags )
{

    float_exception_flags |= flags;

}

/*----------------------------------------------------------------------------
| Internal canonical NaN format.
*----------------------------------------------------------------------------*/
typedef struct {
    flag sign;
    bits64 high, low;
} commonNaNT;

/*----------------------------------------------------------------------------
| Returns 1 if the single-precision floating-point value `a' is infinity;
| otherwise returns 0.
*----------------------------------------------------------------------------*/

flag float32_is_inf( float32 a )
{

    return ( 0xFF000000 == (bits32) ( a<<1 ) );

}

/*----------------------------------------------------------------------------
| Returns 1 if the single-precision floating-point value `a' is a NaN;
| otherwise returns 0.
*----------------------------------------------------------------------------*/

flag float32_is_nan( float32 a )
{

    return ( 0xFF000000 < (bits32) ( a<<1 ) );

}

/*----------------------------------------------------------------------------
| Returns 1 if the single-precision floating-point value `a' is negative;
| otherwise returns 0.
*----------------------------------------------------------------------------*/

flag float32_is_neg( float32 a )
{

    return ( a>>31 );

}

/*----------------------------------------------------------------------------
| Returns 1 if the single-precision floating-point value `a' is a signaling
| NaN; otherwise returns 0.
*----------------------------------------------------------------------------*/

flag float32_is_signaling_nan( float32 a )
{

    return ( ( ( a>>22 ) & 0x1FF ) == 0x1FE ) && ( a & 0x003FFFFF );

}

/*----------------------------------------------------------------------------
| Returns 1 if the single-precision floating-point value `a' is subnormal;
| otherwise returns 0.
*----------------------------------------------------------------------------*/

flag float32_is_subnormal( float32 a )
{

    return ( ( ( a>>23 ) & 0xFF ) == 0 )
        && ( a & 0x007FFFFF );

}

/*----------------------------------------------------------------------------
| Returns 1 if the single-precision floating-point value `a' is zero;
| otherwise returns 0.
*----------------------------------------------------------------------------*/

flag float32_is_zero( float32 a )
{

    return ( ( a & 0x7FFFFFFF ) == 0);

}

/*----------------------------------------------------------------------------
| Returns the single-precision floating-point value `a' with positive sign.
*----------------------------------------------------------------------------*/

float32 float32_pos( float32 a )
{

    return ( a & 0x7FFFFFFF );

}

/*----------------------------------------------------------------------------
| Returns the single-precision floating-point value `a' with negative sign.
*----------------------------------------------------------------------------*/

float32 float32_neg( float32 a )
{

    return ( a | 0x80000000 );

}

/*----------------------------------------------------------------------------
| Returns the result of converting the single-precision floating-point
| signaling NaN `a' to a quiet NaN.
*----------------------------------------------------------------------------*/
float32 float32_snan_to_qnan( float32 a )
{

    return ( a | 0x00400000 );

}

/*----------------------------------------------------------------------------
| Builds a single-precision floating-point value.                   
*----------------------------------------------------------------------------*/

float32 float32_build( int sign, int exp, bits32 fract )
{

    return ( (bits32) ( sign ? 0x80000000 : 0 ) )
        | ( (bits32) ( exp & 0xFF ) << 23 )  
        | ( fract & 0x007FFFFF );

}

/*----------------------------------------------------------------------------
| Returns the exponent of single-precision floating-point value `a'.
*----------------------------------------------------------------------------*/

bits16 float32_exp( float32 a )
{

    return (( a>>23 ) & 0xFF );

}

/*----------------------------------------------------------------------------
| Returns the fraction of single-precision floating-point value `a'.
*----------------------------------------------------------------------------*/

bits32 float32_fract( float32 a )
{

    return ( a & 0x007FFFFF );

}

/*----------------------------------------------------------------------------
| Returns the result of converting the single-precision floating-point NaN
| `a' to the canonical NaN format.  If `a' is a signaling NaN, the invalid
| exception is raised.
*----------------------------------------------------------------------------*/

static commonNaNT float32ToCommonNaN( float32 a )
{
    commonNaNT z;

    if ( float32_is_signaling_nan( a ) ) float_raise( float_flag_invalid );
    z.sign = a>>31;
    z.low = 0;
    z.high = ( (bits64) a )<<41;
    return z;

}

/*----------------------------------------------------------------------------
| Returns the result of converting the canonical NaN `a' to the single-
| precision floating-point format.
*----------------------------------------------------------------------------*/

static float32 commonNaNToFloat32( commonNaNT a )
{

    return ( ( (bits32) a.sign )<<31 ) | 0x7FC00000 | ( a.high>>41 );

}

/*----------------------------------------------------------------------------
| Takes two single-precision floating-point values `a' and `b', one of which
| is a NaN, and returns the appropriate NaN result.  If either `a' or `b' is a
| signaling NaN, the invalid exception is raised.
*----------------------------------------------------------------------------*/

static float32 propagateFloat32NaN( float32 a, float32 b )
{
    flag aIsNaN, aIsSignalingNaN, bIsNaN, bIsSignalingNaN;

    aIsNaN = float32_is_nan( a );
    aIsSignalingNaN = float32_is_signaling_nan( a );
    bIsNaN = float32_is_nan( b );
    bIsSignalingNaN = float32_is_signaling_nan( b );
    a |= 0x00400000;
    b |= 0x00400000;
    if ( aIsSignalingNaN | bIsSignalingNaN ) float_raise( float_flag_invalid );
    if ( aIsNaN ) {
        return ( aIsSignalingNaN & bIsNaN ) ? b : a;
    }
    else {
        return b;
    }

}

/*----------------------------------------------------------------------------
| Returns 1 if the double-precision floating-point value `a' is infinity;
| otherwise returns 0.
*----------------------------------------------------------------------------*/

flag float64_is_inf( float64 a )
{

    return ( LIT64( 0xFFE0000000000000 ) == (bits64) ( a<<1 ) );

}

/*----------------------------------------------------------------------------
| Returns 1 if the double-precision floating-point value `a' is a NaN;
| otherwise returns 0.
*----------------------------------------------------------------------------*/

flag float64_is_nan( float64 a )
{

    return ( LIT64( 0xFFE0000000000000 ) < (bits64) ( a<<1 ) );

}

/*----------------------------------------------------------------------------
| Returns 1 if the double-precision floating-point value `a' is negative;
| otherwise returns 0.
*----------------------------------------------------------------------------*/

flag float64_is_neg( float64 a )
{

    return ( a>>63 );

}

/*----------------------------------------------------------------------------
| Returns 1 if the double-precision floating-point value `a' is a signaling
| NaN; otherwise returns 0.
*----------------------------------------------------------------------------*/

flag float64_is_signaling_nan( float64 a )
{

    return
           ( ( ( a>>51 ) & 0xFFF ) == 0xFFE )
        && ( a & LIT64( 0x0007FFFFFFFFFFFF ) );

}

/*----------------------------------------------------------------------------
| Returns 1 if the double-precision floating-point value `a' is subnormal;
| otherwise returns 0.
*----------------------------------------------------------------------------*/

flag float64_is_subnormal( float64 a )
{

    return ( ( ( a>>52 ) & 0x7FF ) == 0 )
        && ( a & LIT64( 0x000FFFFFFFFFFFFF ) );

}

/*----------------------------------------------------------------------------
| Returns 1 if the double-precision floating-point value `a' is zero;
| otherwise returns 0.
*----------------------------------------------------------------------------*/

flag float64_is_zero( float64 a )
{

    return ( ( a & LIT64( 0x7FFFFFFFFFFFFFFF ) ) == 0);

}

/*----------------------------------------------------------------------------
| Returns the double-precision floating-point value `a' with positive sign.
*----------------------------------------------------------------------------*/

float64 float64_pos( float64 a )
{

    return ( a & LIT64( 0x7FFFFFFFFFFFFFFF ) );

}

/*----------------------------------------------------------------------------
| Returns the double-precision floating-point value `a' with negative sign.
*----------------------------------------------------------------------------*/

float64 float64_neg( float64 a )
{

    return ( a | LIT64( 0x8000000000000000 ) );

}

/*----------------------------------------------------------------------------
| Returns the result of converting the double-precision floating-point
| signaling NaN `a' to a quiet NaN.
*----------------------------------------------------------------------------*/
float64 float64_snan_to_qnan( float64 a )
{

    return ( a | LIT64( 0x0008000000000000 ) );

}

/*----------------------------------------------------------------------------
| Builds a double-precision floating-point value.                   
*----------------------------------------------------------------------------*/

float64 float64_build( int sign, int exp, bits64 fract )
{

    return ( (bits64) ( sign ? LIT64( 0x8000000000000000 ) : 0 )
        | ( (bits64) ( exp & 0x7FF ) << 52 )  
        | ( fract & LIT64( 0x000FFFFFFFFFFFFF ) ) );

}

/*----------------------------------------------------------------------------
| Returns the exponent of double-precision floating-point value `a'.
*----------------------------------------------------------------------------*/

bits16 float64_exp( float64 a )
{

    return (( a>>52 ) & 0x7FF );

}

/*----------------------------------------------------------------------------
| Returns the fraction of double-precision floating-point value `a'.
*----------------------------------------------------------------------------*/

bits64 float64_fract( float64 a )
{

    return ( a & LIT64( 0x000FFFFFFFFFFFFF ) );

}

/*----------------------------------------------------------------------------
| Returns the result of converting the double-precision floating-point NaN
| `a' to the canonical NaN format.  If `a' is a signaling NaN, the invalid
| exception is raised.
*----------------------------------------------------------------------------*/

static commonNaNT float64ToCommonNaN( float64 a )
{
    commonNaNT z;

    if ( float64_is_signaling_nan( a ) ) float_raise( float_flag_invalid );
    z.sign = a>>63;
    z.low = 0;
    z.high = a<<12;
    return z;

}

/*----------------------------------------------------------------------------
| Returns the result of converting the canonical NaN `a' to the double-
| precision floating-point format.
*----------------------------------------------------------------------------*/

static float64 commonNaNToFloat64( commonNaNT a )
{

    return
          ( ( (bits64) a.sign )<<63 )
        | LIT64( 0x7FF8000000000000 )
        | ( a.high>>12 );

}

/*----------------------------------------------------------------------------
| Takes two double-precision floating-point values `a' and `b', one of which
| is a NaN, and returns the appropriate NaN result.  If either `a' or `b' is a
| signaling NaN, the invalid exception is raised.
*----------------------------------------------------------------------------*/

static float64 propagateFloat64NaN( float64 a, float64 b )
{
    flag aIsNaN, aIsSignalingNaN, bIsNaN, bIsSignalingNaN;

    aIsNaN = float64_is_nan( a );
    aIsSignalingNaN = float64_is_signaling_nan( a );
    bIsNaN = float64_is_nan( b );
    bIsSignalingNaN = float64_is_signaling_nan( b );
    a |= LIT64( 0x0008000000000000 );
    b |= LIT64( 0x0008000000000000 );
    if ( aIsSignalingNaN | bIsSignalingNaN ) float_raise( float_flag_invalid );
    if ( aIsNaN ) {
        return ( aIsSignalingNaN & bIsNaN ) ? b : a;
    }
    else {
        return b;
    }

}

#ifdef FLOATX80

/*----------------------------------------------------------------------------
| The pattern for a default generated extended double-precision NaN.  The
| `high' and `low' values hold the most- and least-significant bits,
| respectively.
*----------------------------------------------------------------------------*/
#define floatx80_default_nan_high 0xFFFF
#define floatx80_default_nan_low  LIT64( 0xFFFFFFFFFFFFFFFF )

/*----------------------------------------------------------------------------
| Returns 1 if the extended double-precision floating-point value `a' is a
| NaN; otherwise returns 0.
*----------------------------------------------------------------------------*/

flag floatx80_is_nan( floatx80 a )
{

    return ( ( a.high & 0x7FFF ) == 0x7FFF ) && (bits64) ( a.low<<1 );

}

/*----------------------------------------------------------------------------
| Returns 1 if the extended double-precision floating-point value `a' is a
| signaling NaN; otherwise returns 0.
*----------------------------------------------------------------------------*/

flag floatx80_is_signaling_nan( floatx80 a )
{
    bits64 aLow;

    aLow = a.low & ~ LIT64( 0x4000000000000000 );
    return
           ( ( a.high & 0x7FFF ) == 0x7FFF )
        && (bits64) ( aLow<<1 )
        && ( a.low == aLow );

}

/*----------------------------------------------------------------------------
| Returns the result of converting the extended double-precision floating-
| point NaN `a' to the canonical NaN format.  If `a' is a signaling NaN, the
| invalid exception is raised.
*----------------------------------------------------------------------------*/

static commonNaNT floatx80ToCommonNaN( floatx80 a )
{
    commonNaNT z;

    if ( floatx80_is_signaling_nan( a ) ) float_raise( float_flag_invalid );
    z.sign = a.high>>15;
    z.low = 0;
    z.high = a.low<<1;
    return z;

}

/*----------------------------------------------------------------------------
| Returns the result of converting the canonical NaN `a' to the extended
| double-precision floating-point format.
*----------------------------------------------------------------------------*/

static floatx80 commonNaNToFloatx80( commonNaNT a )
{
    floatx80 z;

    z.low = LIT64( 0xC000000000000000 ) | ( a.high>>1 );
    z.high = ( ( (bits16) a.sign )<<15 ) | 0x7FFF;
    return z;

}

/*----------------------------------------------------------------------------
| Takes two extended double-precision floating-point values `a' and `b', one
| of which is a NaN, and returns the appropriate NaN result.  If either `a' or
| `b' is a signaling NaN, the invalid exception is raised.
*----------------------------------------------------------------------------*/

static floatx80 propagateFloatx80NaN( floatx80 a, floatx80 b )
{
    flag aIsNaN, aIsSignalingNaN, bIsNaN, bIsSignalingNaN;

    aIsNaN = floatx80_is_nan( a );
    aIsSignalingNaN = floatx80_is_signaling_nan( a );
    bIsNaN = floatx80_is_nan( b );
    bIsSignalingNaN = floatx80_is_signaling_nan( b );
    a.low |= LIT64( 0xC000000000000000 );
    b.low |= LIT64( 0xC000000000000000 );
    if ( aIsSignalingNaN | bIsSignalingNaN ) float_raise( float_flag_invalid );
    if ( aIsNaN ) {
        return ( aIsSignalingNaN & bIsNaN ) ? b : a;
    }
    else {
        return b;
    }

}

#endif

#ifdef FLOAT128

/*----------------------------------------------------------------------------
| Returns 1 if the quadruple-precision floating-point value `a' is infinity;
| otherwise returns 0.
*----------------------------------------------------------------------------*/

flag float128_is_inf( float128 a )
{

    return ( a.low == 0
        && ( (bits64) ( a.high<<1 ) == LIT64( 0xFFFE000000000000 ) ) );

}

/*----------------------------------------------------------------------------
| Returns 1 if the quadruple-precision floating-point value `a' is a NaN;
| otherwise returns 0.
*----------------------------------------------------------------------------*/

flag float128_is_nan( float128 a )
{

    return
           ( LIT64( 0xFFFE000000000000 ) <= (bits64) ( a.high<<1 ) )
        && ( a.low || ( a.high & LIT64( 0x0000FFFFFFFFFFFF ) ) );

}

/*----------------------------------------------------------------------------
| Returns 1 if the quadruple-precision floating-point value `a' is negative;
| otherwise returns 0.
*----------------------------------------------------------------------------*/

flag float128_is_neg( float128 a )
{

    return ( a.high>>63 );

}

/*----------------------------------------------------------------------------
| Returns 1 if the quadruple-precision floating-point value `a' is a
| signaling NaN; otherwise returns 0.
*----------------------------------------------------------------------------*/

flag float128_is_signaling_nan( float128 a )
{

    return
           ( ( ( a.high>>47 ) & 0xFFFF ) == 0xFFFE )
        && ( a.low || ( a.high & LIT64( 0x00007FFFFFFFFFFF ) ) );

}

/*----------------------------------------------------------------------------
| Returns 1 if the quadruple-precision floating-point value `a' is subnormal;
| otherwise returns 0.
*----------------------------------------------------------------------------*/

flag float128_is_subnormal( float128 a )
{

    return ( ( ( a.high>>48 ) & 0x7FFF ) == 0 )
        && ( a.low || ( a.high & LIT64( 0x0000FFFFFFFFFFFF ) ) );

}

/*----------------------------------------------------------------------------
| Returns 1 if the quadruple-precision floating-point value `a' is zero;
| otherwise returns 0.
*----------------------------------------------------------------------------*/

flag float128_is_zero( float128 a )
{

    return ( a.low == 0 && ( a.high & LIT64( 0x7FFFFFFFFFFFFFFF ) ) == 0 );

}

/*----------------------------------------------------------------------------
| Returns the quadruple-precision floating-point value `a' with positive sign.
*----------------------------------------------------------------------------*/

float128 float128_pos( float128 a )
{
    float128 result;

    result.high = ( a.high & LIT64( 0x7FFFFFFFFFFFFFFF ) );
    result.low = a.low;
    return result;

}

/*----------------------------------------------------------------------------
| Returns the quadruple-precision floating-point value `a' with negative sign.
*----------------------------------------------------------------------------*/

float128 float128_neg( float128 a )
{
    float128 result;                                      

    result.high = ( a.high | LIT64( 0x8000000000000000 ) );
    result.low = a.low;
    return result;

}

/*----------------------------------------------------------------------------
| Returns the result of converting the quadruple-precision floating-point
| signaling NaN `a' to a quiet NaN.
*----------------------------------------------------------------------------*/
float128 float128_snan_to_qnan( float128 a )
{
    float128 result;                                      

    result.high = ( a.high | LIT64( 0x0000800000000000 ) );
    result.low = a.low;
    return result;

}

/*----------------------------------------------------------------------------
| Builds a quadruple-precision floating-point value.
*----------------------------------------------------------------------------*/

float128 float128_build( int sign, int exp, bits64 fract_high, bits64 fract_low )
{
    float128 result;                                      

    result.high = ( (bits64) ( sign ? LIT64( 0x8000000000000000 ) : 0 )
        | ( (bits64) ( exp & 0x7FFF ) << 48 )  
        | ( fract_high & LIT64( 0x0000FFFFFFFFFFFF ) ) );
    result.low = fract_low;
    return result;

}

/*----------------------------------------------------------------------------
| Returns the exponent of quadruple-precision floating-point value `a'.
*----------------------------------------------------------------------------*/

bits16 float128_exp( float128 a )
{

    return (( a.high>>48 ) & 0x7FFF );

}

/*----------------------------------------------------------------------------
| Returns the high-order 48 bits of the fraction of quadruple-precision
| floating-point value `a'.
*----------------------------------------------------------------------------*/

bits64 float128_fract_high( float128 a )
{

    return ( a.high & LIT64( 0x0000FFFFFFFFFFFF ) );

}

/*----------------------------------------------------------------------------
| Returns the low-order 64 bits of the fraction of quadruple-precision
| floating-point value `a'.
*----------------------------------------------------------------------------*/

bits64 float128_fract_low( float128 a )
{

    return ( a.low );

}

/*----------------------------------------------------------------------------
| Returns the result of converting the quadruple-precision floating-point NaN
| `a' to the canonical NaN format.  If `a' is a signaling NaN, the invalid
| exception is raised.
*----------------------------------------------------------------------------*/

static commonNaNT float128ToCommonNaN( float128 a )
{
    commonNaNT z;

    if ( float128_is_signaling_nan( a ) ) float_raise( float_flag_invalid );
    z.sign = a.high>>63;
    shortShift128Left( a.high, a.low, 16, &z.high, &z.low );
    return z;

}

/*----------------------------------------------------------------------------
| Returns the result of converting the canonical NaN `a' to the quadruple-
| precision floating-point format.
*----------------------------------------------------------------------------*/

static float128 commonNaNToFloat128( commonNaNT a )
{
    float128 z;

    shift128Right( a.high, a.low, 16, &z.high, &z.low );
    z.high |= ( ( (bits64) a.sign )<<63 ) | LIT64( 0x7FFF800000000000 );
    return z;

}

/*----------------------------------------------------------------------------
| Takes two quadruple-precision floating-point values `a' and `b', one of
| which is a NaN, and returns the appropriate NaN result.  If either `a' or
| `b' is a signaling NaN, the invalid exception is raised.
*----------------------------------------------------------------------------*/

static float128 propagateFloat128NaN( float128 a, float128 b )
{
    flag aIsNaN, aIsSignalingNaN, bIsNaN, bIsSignalingNaN;

    aIsNaN = float128_is_nan( a );
    aIsSignalingNaN = float128_is_signaling_nan( a );
    bIsNaN = float128_is_nan( b );
    bIsSignalingNaN = float128_is_signaling_nan( b );
    a.high |= LIT64( 0x0000800000000000 );
    b.high |= LIT64( 0x0000800000000000 );
    if ( aIsSignalingNaN | bIsSignalingNaN ) float_raise( float_flag_invalid );
    if ( aIsNaN ) {
        return ( aIsSignalingNaN & bIsNaN ) ? b : a;
    }
    else {
        return b;
    }

}

#endif