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

This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic
Package, Release 3, by John R. Hauser.

Copyright 2011, 2012, 2013, 2014 The Regents of the University of California
(Regents).  All Rights Reserved.  Redistribution and use in source and binary
forms, with or without modification, are permitted provided that the following
conditions are met:

Redistributions of source code must retain the above copyright notice,
this list of conditions, and the following two paragraphs of disclaimer.
Redistributions in binary form must reproduce the above copyright notice,
this list of conditions, and the following two paragraphs of disclaimer in the
documentation and/or other materials provided with the distribution.  Neither
the name of the Regents nor the names of its contributors may be used to
endorse or promote products derived from this software without specific prior
written permission.

IN NO EVENT SHALL REGENTS BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT,
SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS, ARISING
OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF REGENTS HAS
BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

REGENTS SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT LIMITED
TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE.  THE SOFTWARE AND ACCOMPANYING DOCUMENTATION, IF ANY, PROVIDED
HEREUNDER IS PROVIDED "AS IS".  REGENTS HAS NO OBLIGATION TO PROVIDE
MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.

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

#include <stdbool.h>
#include <stdint.h>
#include "platform.h"
#include "internals.h"
#include "specialize.h"
#include "softfloat.h"

#ifdef SOFTFLOAT_FAST_INT64

float64_t
 softfloat_mulAddF64(
     uint_fast64_t uiA, uint_fast64_t uiB, uint_fast64_t uiC, uint_fast8_t op )
{
    bool signA;
    int_fast16_t expA;
    uint_fast64_t sigA;
    bool signB;
    int_fast16_t expB;
    uint_fast64_t sigB;
    bool signC;
    int_fast16_t expC;
    uint_fast64_t sigC;
    bool signZ;
    uint_fast64_t magBits, uiZ;
    struct exp16_sig64 normExpSig;
    int_fast16_t expZ;
    struct uint128 sig128Z;
    uint_fast64_t sigZ;
    int_fast16_t expDiff;
    struct uint128 sig128C;
    int_fast8_t shiftCount;
    union ui64_f64 uZ;

    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
    signA = signF64UI( uiA );
    expA  = expF64UI( uiA );
    sigA  = fracF64UI( uiA );
    signB = signF64UI( uiB );
    expB  = expF64UI( uiB );
    sigB  = fracF64UI( uiB );
    signC = signF64UI( uiC ) ^ (op == softfloat_mulAdd_subC);
    expC  = expF64UI( uiC );
    sigC  = fracF64UI( uiC );
    signZ = signA ^ signB ^ (op == softfloat_mulAdd_subProd);
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
    if ( expA == 0x7FF ) {
        if ( sigA || ((expB == 0x7FF) && sigB) ) goto propagateNaN_ABC;
        magBits = expB | sigB;
        goto infProdArg;
    }
    if ( expB == 0x7FF ) {
        if ( sigB ) goto propagateNaN_ABC;
        magBits = expA | sigA;
        goto infProdArg;
    }
    if ( expC == 0x7FF ) {
        if ( sigC ) {
            uiZ = 0;
            goto propagateNaN_ZC;
        }
        uiZ = uiC;
        goto uiZ;
    }
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
    if ( ! expA ) {
        if ( ! sigA ) goto zeroProd;
        normExpSig = softfloat_normSubnormalF64Sig( sigA );
        expA = normExpSig.exp;
        sigA = normExpSig.sig;
    }
    if ( ! expB ) {
        if ( ! sigB ) goto zeroProd;
        normExpSig = softfloat_normSubnormalF64Sig( sigB );
        expB = normExpSig.exp;
        sigB = normExpSig.sig;
    }
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
    expZ = expA + expB - 0x3FE;
    sigA = (sigA | UINT64_C( 0x0010000000000000 ))<<10;
    sigB = (sigB | UINT64_C( 0x0010000000000000 ))<<10;
    sig128Z = softfloat_mul64To128( sigA, sigB );
    if ( sig128Z.v64 < UINT64_C( 0x2000000000000000 ) ) {
        --expZ;
        sig128Z =
            softfloat_add128(
                sig128Z.v64, sig128Z.v0, sig128Z.v64, sig128Z.v0 );
    }
    if ( ! expC ) {
        if ( ! sigC ) {
            --expZ;
            sigZ = sig128Z.v64<<1 | (sig128Z.v0 != 0);
            goto roundPack;
        }
        normExpSig = softfloat_normSubnormalF64Sig( sigC );
        expC = normExpSig.exp;
        sigC = normExpSig.sig;
    }
    sigC = (sigC | UINT64_C( 0x0010000000000000 ))<<9;
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
    expDiff = expZ - expC;
    if ( expDiff < 0 ) {
        expZ = expC;
        if ( (signZ == signC) || (expDiff < -1) ) {
            sig128Z.v64 = softfloat_shiftRightJam64( sig128Z.v64, -expDiff );
        } else {
            sig128Z =
                softfloat_shortShiftRightJam128( sig128Z.v64, sig128Z.v0, 1 );
        }
    } else if ( expDiff ) {
        sig128C = softfloat_shiftRightJam128( sigC, 0, expDiff );
    }
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
    if ( signZ == signC ) {
        /*--------------------------------------------------------------------
        *--------------------------------------------------------------------*/
        if ( expDiff <= 0 ) {
            sigZ = (sigC + sig128Z.v64) | (sig128Z.v0 != 0);
        } else {
            sig128Z =
                softfloat_add128(
                    sig128Z.v64, sig128Z.v0, sig128C.v64, sig128C.v0 );
            sigZ = sig128Z.v64 | (sig128Z.v0 != 0);
        }
        if ( sigZ < UINT64_C( 0x4000000000000000 ) ) {
            --expZ;
            sigZ <<= 1;
        }
    } else {
        /*--------------------------------------------------------------------
        *--------------------------------------------------------------------*/
        if ( expDiff < 0 ) {
            signZ = signC;
            sig128Z = softfloat_sub128( sigC, 0, sig128Z.v64, sig128Z.v0 );
        } else if ( ! expDiff ) {
            sig128Z.v64 = sig128Z.v64 - sigC;
            if ( ! (sig128Z.v64 | sig128Z.v0) ) goto completeCancellation;
            if ( sig128Z.v64 & UINT64_C( 0x8000000000000000 ) ) {
                signZ ^= 1;
                sig128Z = softfloat_sub128( 0, 0, sig128Z.v64, sig128Z.v0 );
            }
        } else {
            sig128Z =
                softfloat_sub128(
                    sig128Z.v64, sig128Z.v0, sig128C.v64, sig128C.v0 );
        }
        /*--------------------------------------------------------------------
        *--------------------------------------------------------------------*/
        if ( ! sig128Z.v64 ) {
            expZ -= 64;
            sig128Z.v64 = sig128Z.v0;
            sig128Z.v0 = 0;
        }
        shiftCount = softfloat_countLeadingZeros64( sig128Z.v64 ) - 1;
        expZ -= shiftCount;
        if ( shiftCount < 0 ) {
            sigZ = softfloat_shortShiftRightJam64( sig128Z.v64, -shiftCount );
        } else {
            sig128Z =
                softfloat_shortShiftLeft128(
                    sig128Z.v64, sig128Z.v0, shiftCount );
            sigZ = sig128Z.v64;
        }
        sigZ |= (sig128Z.v0 != 0);
    }
 roundPack:
    return softfloat_roundPackToF64( signZ, expZ, sigZ );
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
 propagateNaN_ABC:
    uiZ = softfloat_propagateNaNF64UI( uiA, uiB );
    goto propagateNaN_ZC;
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
 infProdArg:
    if ( magBits ) {
        uiZ = packToF64UI( signZ, 0x7FF, 0 );
        if ( expC != 0x7FF ) goto uiZ;
        if ( sigC ) goto propagateNaN_ZC;
        if ( signZ == signC ) goto uiZ;
    }
 invalid:
    softfloat_raiseFlags( softfloat_flag_invalid );
    uiZ = defaultNaNF64UI;
 propagateNaN_ZC:
    uiZ = softfloat_propagateNaNF64UI( uiZ, uiC );
    goto uiZ;
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
 zeroProd:
    uiZ = uiC;
    if ( ! (expC | sigC) && (signZ != signC) ) {
 completeCancellation:
        uiZ =
            packToF64UI( softfloat_roundingMode == softfloat_round_min, 0, 0 );
    }
 uiZ:
    uZ.ui = uiZ;
    return uZ.f;

}

#else

float64_t
 softfloat_mulAddF64(
     uint_fast64_t uiA, uint_fast64_t uiB, uint_fast64_t uiC, uint_fast8_t op )
{
    bool signA;
    int_fast16_t expA;
    uint64_t sigA;
    bool signB;
    int_fast16_t expB;
    uint64_t sigB;
    bool signC;
    int_fast16_t expC;
    uint64_t sigC;
    bool signZ;
    uint64_t magBits, uiZ;
    struct exp16_sig64 normExpSig;
    int_fast16_t expZ;
    uint32_t sig128Z[4];
    uint64_t sigZ;
    int_fast16_t shiftCount, expDiff;
    uint32_t sig128C[4];
    union ui64_f64 uZ;

    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
    signA = signF64UI( uiA );
    expA  = expF64UI( uiA );
    sigA  = fracF64UI( uiA );
    signB = signF64UI( uiB );
    expB  = expF64UI( uiB );
    sigB  = fracF64UI( uiB );
    signC = signF64UI( uiC ) ^ (op == softfloat_mulAdd_subC);
    expC  = expF64UI( uiC );
    sigC  = fracF64UI( uiC );
    signZ = signA ^ signB ^ (op == softfloat_mulAdd_subProd);
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
    if ( expA == 0x7FF ) {
        if ( sigA || ((expB == 0x7FF) && sigB) ) goto propagateNaN_ABC;
        magBits = expB | sigB;
        goto infProdArg;
    }
    if ( expB == 0x7FF ) {
        if ( sigB ) goto propagateNaN_ABC;
        magBits = expA | sigA;
        goto infProdArg;
    }
    if ( expC == 0x7FF ) {
        if ( sigC ) {
            uiZ = 0;
            goto propagateNaN_ZC;
        }
        uiZ = uiC;
        goto uiZ;
    }
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
    if ( ! expA ) {
        if ( ! sigA ) goto zeroProd;
        normExpSig = softfloat_normSubnormalF64Sig( sigA );
        expA = normExpSig.exp;
        sigA = normExpSig.sig;
    }
    if ( ! expB ) {
        if ( ! sigB ) goto zeroProd;
        normExpSig = softfloat_normSubnormalF64Sig( sigB );
        expB = normExpSig.exp;
        sigB = normExpSig.sig;
    }
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
    expZ = expA + expB - 0x3FE;
    sigA = (sigA | UINT64_C( 0x0010000000000000 ))<<10;
    sigB = (sigB | UINT64_C( 0x0010000000000000 ))<<11;
    softfloat_mul64To128M( sigA, sigB, sig128Z );
    sigZ =
        (uint64_t) sig128Z[indexWord( 4, 3 )]<<32 | sig128Z[indexWord( 4, 2 )];
    shiftCount = 0;
    if ( ! (sigZ & UINT64_C( 0x4000000000000000 )) ) {
        --expZ;
        shiftCount = -1;
    }
    if ( ! expC ) {
        if ( ! sigC ) {
            if ( shiftCount ) sigZ <<= 1;
            goto sigZ;
        }
        normExpSig = softfloat_normSubnormalF64Sig( sigC );
        expC = normExpSig.exp;
        sigC = normExpSig.sig;
    }
    sigC = (sigC | UINT64_C( 0x0010000000000000 ))<<10;
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
    expDiff = expZ - expC;
    if ( expDiff < 0 ) {
        expZ = expC;
        if ( (signZ == signC) || (expDiff < -1) ) {
            shiftCount -= expDiff;
            if ( shiftCount) {
                sigZ = softfloat_shiftRightJam64( sigZ, shiftCount );
            }
        } else {
            if ( ! shiftCount ) {
                softfloat_shortShiftRight128M( sig128Z, 1, sig128Z );
            }
        }
    } else {
        if ( shiftCount ) softfloat_add128M( sig128Z, sig128Z, sig128Z );
        if ( ! expDiff ) {
            sigZ =
                (uint64_t) sig128Z[indexWord( 4, 3 )]<<32
                    | sig128Z[indexWord( 4, 2 )];
        } else {
            sig128C[indexWord( 4, 3 )] = sigC>>32;
            sig128C[indexWord( 4, 2 )] = sigC;
            sig128C[indexWord( 4, 1 )] = 0;
            sig128C[indexWord( 4, 0 )] = 0;
            softfloat_shiftRightJam128M( sig128C, expDiff, sig128C );
        }
    }
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
    if ( signZ == signC ) {
        /*--------------------------------------------------------------------
        *--------------------------------------------------------------------*/
        if ( expDiff <= 0 ) {
            sigZ += sigC;
        } else {
            softfloat_add128M( sig128Z, sig128C, sig128Z );
            sigZ =
                (uint64_t) sig128Z[indexWord( 4, 3 )]<<32
                    | sig128Z[indexWord( 4, 2 )];
        }
        if ( sigZ & UINT64_C( 0x8000000000000000 ) ) {
            ++expZ;
            sigZ = softfloat_shortShiftRightJam64( sigZ, 1 );
        }
    } else {
        /*--------------------------------------------------------------------
        *--------------------------------------------------------------------*/
        if ( expDiff < 0 ) {
            signZ = signC;
            if ( expDiff < -1 ) {
                sigZ = sigC - sigZ;
                if (
                    sig128Z[indexWord( 4, 1 )] || sig128Z[indexWord( 4, 0 )]
                ) {
                    sigZ = (sigZ - 1) | 1;
                }
                if ( ! (sigZ & UINT64_C( 0x4000000000000000 )) ) {
                    --expZ;
                    sigZ <<= 1;
                }
                goto roundPack;
            } else {
                sig128C[indexWord( 4, 3 )] = sigC>>32;
                sig128C[indexWord( 4, 2 )] = sigC;
                sig128C[indexWord( 4, 1 )] = 0;
                sig128C[indexWord( 4, 0 )] = 0;
                softfloat_sub128M( sig128C, sig128Z, sig128Z );
            }
        } else if ( ! expDiff ) {
            sigZ -= sigC;
            if (
                ! sigZ && ! sig128Z[indexWord( 4, 1 )]
                    && ! sig128Z[indexWord( 4, 0 )]
            ) {
                goto completeCancellation;
            }
            sig128Z[indexWord( 4, 3 )] = sigZ>>32;
            sig128Z[indexWord( 4, 2 )] = sigZ;
            if ( sigZ & UINT64_C( 0x8000000000000000 ) ) {
                signZ ^= 1;
                softfloat_negX128M( sig128Z );
            }
        } else {
            softfloat_sub128M( sig128Z, sig128C, sig128Z );
            if ( 1 < expDiff ) {
                sigZ =
                    (uint64_t) sig128Z[indexWord( 4, 3 )]<<32
                        | sig128Z[indexWord( 4, 2 )];
                if ( ! (sigZ & UINT64_C( 0x4000000000000000 )) ) {
                    --expZ;
                    sigZ <<= 1;
                }
                goto sigZ;
            }
        }
        /*--------------------------------------------------------------------
        *--------------------------------------------------------------------*/
        shiftCount = 0;
        sigZ =
            (uint64_t) sig128Z[indexWord( 4, 3 )]<<32
                | sig128Z[indexWord( 4, 2 )];
        if ( ! sigZ ) {
            shiftCount = 64;
            sigZ =
                (uint64_t) sig128Z[indexWord( 4, 1 )]<<32
                    | sig128Z[indexWord( 4, 0 )];
        }
        shiftCount += softfloat_countLeadingZeros64( sigZ ) - 1;
        if ( shiftCount ) {
            expZ -= shiftCount;
            softfloat_shiftLeft128M( sig128Z, shiftCount, sig128Z );
            sigZ =
                (uint64_t) sig128Z[indexWord( 4, 3 )]<<32
                    | sig128Z[indexWord( 4, 2 )];
        }
    }
 sigZ:
    if ( sig128Z[indexWord( 4, 1 )] || sig128Z[indexWord( 4, 0 )] ) sigZ |= 1;
 roundPack:
    return softfloat_roundPackToF64( signZ, expZ - 1, sigZ );
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
 propagateNaN_ABC:
    uiZ = softfloat_propagateNaNF64UI( uiA, uiB );
    goto propagateNaN_ZC;
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
 infProdArg:
    if ( magBits ) {
        uiZ = packToF64UI( signZ, 0x7FF, 0 );
        if ( expC != 0x7FF ) goto uiZ;
        if ( sigC ) goto propagateNaN_ZC;
        if ( signZ == signC ) goto uiZ;
    }
 invalid:
    softfloat_raiseFlags( softfloat_flag_invalid );
    uiZ = defaultNaNF64UI;
 propagateNaN_ZC:
    uiZ = softfloat_propagateNaNF64UI( uiZ, uiC );
    goto uiZ;
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
 zeroProd:
    uiZ = uiC;
    if ( ! (expC | sigC) && (signZ != signC) ) {
 completeCancellation:
        uiZ =
            packToF64UI( softfloat_roundingMode == softfloat_round_min, 0, 0 );
    }
 uiZ:
    uZ.ui = uiZ;
    return uZ.f;

}

#endif