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

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"

float128_t
 softfloat_mulAddF128(
     uint_fast64_t uiA64,
     uint_fast64_t uiA0,
     uint_fast64_t uiB64,
     uint_fast64_t uiB0,
     uint_fast64_t uiC64,
     uint_fast64_t uiC0,
     uint_fast8_t op
 )
{
    bool signA;
    int_fast32_t expA;
    struct uint128 sigA;
    bool signB;
    int_fast32_t expB;
    struct uint128 sigB;
    bool signC;
    int_fast32_t expC;
    struct uint128 sigC;
    bool signZ;
    uint_fast64_t magBits;
    struct uint128 uiZ;
    struct exp32_sig128 normExpSig;
    int_fast32_t expZ;
    uint64_t sig256Z[4];
    struct uint128 sigZ;
    int_fast32_t shiftCount, expDiff;
    struct uint128 x128;
    uint64_t sig256C[4];
    static uint64_t zero256[4] = INIT_UINTM4( 0, 0, 0, 0 );
    uint_fast64_t sigZExtra, sig256Z0;
    union ui128_f128 uZ;

    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
    signA = signF128UI64( uiA64 );
    expA  = expF128UI64( uiA64 );
    sigA.v64 = fracF128UI64( uiA64 );
    sigA.v0  = uiA0;
    signB = signF128UI64( uiB64 );
    expB  = expF128UI64( uiB64 );
    sigB.v64 = fracF128UI64( uiB64 );
    sigB.v0  = uiB0;
    signC = signF128UI64( uiC64 ) ^ (op == softfloat_mulAdd_subC);
    expC  = expF128UI64( uiC64 );
    sigC.v64 = fracF128UI64( uiC64 );
    sigC.v0  = uiC0;
    signZ = signA ^ signB ^ (op == softfloat_mulAdd_subProd);
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
    if ( expA == 0x7FFF ) {
        if (
            (sigA.v64 | sigA.v0) || ((expB == 0x7FFF) && (sigB.v64 | sigB.v0))
        ) {
            goto propagateNaN_ABC;
        }
        magBits = expB | sigB.v64 | sigB.v0;
        goto infProdArg;
    }
    if ( expB == 0x7FFF ) {
        if ( sigB.v64 | sigB.v0 ) goto propagateNaN_ABC;
        magBits = expA | sigA.v64 | sigA.v0;
        goto infProdArg;
    }
    if ( expC == 0x7FFF ) {
        if ( sigC.v64 | sigC.v0 ) {
            uiZ.v64 = 0;
            uiZ.v0  = 0;
            goto propagateNaN_ZC;
        }
        uiZ.v64 = uiC64;
        uiZ.v0  = uiC0;
        goto uiZ;
    }
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
    if ( ! expA ) {
        if ( ! (sigA.v64 | sigA.v0) ) goto zeroProd;
        normExpSig = softfloat_normSubnormalF128Sig( sigA.v64, sigA.v0 );
        expA = normExpSig.exp;
        sigA = normExpSig.sig;
    }
    if ( ! expB ) {
        if ( ! (sigB.v64 | sigB.v0) ) goto zeroProd;
        normExpSig = softfloat_normSubnormalF128Sig( sigB.v64, sigB.v0 );
        expB = normExpSig.exp;
        sigB = normExpSig.sig;
    }
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
    expZ = expA + expB - 0x3FFE;
    sigA.v64 |= UINT64_C( 0x0001000000000000 );
    sigB.v64 |= UINT64_C( 0x0001000000000000 );
    sigA = softfloat_shortShiftLeft128( sigA.v64, sigA.v0, 8 );
    sigB = softfloat_shortShiftLeft128( sigB.v64, sigB.v0, 15 );
    softfloat_mul128To256M( sigA.v64, sigA.v0, sigB.v64, sigB.v0, sig256Z );
    sigZ.v64 = sig256Z[indexWord( 4, 3 )];
    sigZ.v0  = sig256Z[indexWord( 4, 2 )];
    shiftCount = 0;
    if ( ! (sigZ.v64 & UINT64_C( 0x0100000000000000 )) ) {
        --expZ;
        shiftCount = -1;
    }
    if ( ! expC ) {
        if ( ! (sigC.v64 | sigC.v0) ) {
            shiftCount += 8;
            goto sigZ;
        }
        normExpSig = softfloat_normSubnormalF128Sig( sigC.v64, sigC.v0 );
        expC = normExpSig.exp;
        sigC = normExpSig.sig;
    }
    sigC.v64 |= UINT64_C( 0x0001000000000000 );
    sigC = softfloat_shortShiftLeft128( sigC.v64, sigC.v0, 8 );
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
    expDiff = expZ - expC;
    if ( expDiff < 0 ) {
        expZ = expC;
        if ( (signZ == signC) || (expDiff < -1) ) {
            shiftCount -= expDiff;
            if ( shiftCount ) {
                sigZ =
                    softfloat_shiftRightJam128(
                        sigZ.v64, sigZ.v0, shiftCount );
            }
        } else {
            if ( ! shiftCount ) {
                x128 =
                    softfloat_shortShiftRight128(
                        sig256Z[indexWord( 4, 1 )], sig256Z[indexWord( 4, 0 )],
                        1
                    );
                sig256Z[indexWord( 4, 1 )] = (sigZ.v0<<63) | x128.v64;
                sig256Z[indexWord( 4, 0 )] = x128.v0;
                sigZ = softfloat_shortShiftRight128( sigZ.v64, sigZ.v0, 1 );
                sig256Z[indexWord( 4, 3 )] = sigZ.v64;
                sig256Z[indexWord( 4, 2 )] = sigZ.v0;
            }
        }
    } else {
        if ( shiftCount ) softfloat_add256M( sig256Z, sig256Z, sig256Z );
        if ( ! expDiff ) {
            sigZ.v64 = sig256Z[indexWord( 4, 3 )];
            sigZ.v0  = sig256Z[indexWord( 4, 2 )];
        } else {
            sig256C[indexWord( 4, 3 )] = sigC.v64;
            sig256C[indexWord( 4, 2 )] = sigC.v0;
            sig256C[indexWord( 4, 1 )] = 0;
            sig256C[indexWord( 4, 0 )] = 0;
            softfloat_shiftRightJam256M( sig256C, expDiff, sig256C );
        }
    }
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
    shiftCount = 8;
    if ( signZ == signC ) {
        /*--------------------------------------------------------------------
        *--------------------------------------------------------------------*/
        if ( expDiff <= 0 ) {
            sigZ = softfloat_add128( sigC.v64, sigC.v0, sigZ.v64, sigZ.v0 );
        } else {
            softfloat_add256M( sig256Z, sig256C, sig256Z );
            sigZ.v64 = sig256Z[indexWord( 4, 3 )];
            sigZ.v0  = sig256Z[indexWord( 4, 2 )];
        }
        if ( sigZ.v64 & UINT64_C( 0x0200000000000000 ) ) {
            ++expZ;
            shiftCount = 9;
        }
    } else {
        /*--------------------------------------------------------------------
        *--------------------------------------------------------------------*/
        if ( expDiff < 0 ) {
            signZ = signC;
            if ( expDiff < -1 ) {
                sigZ =
                    softfloat_sub128( sigC.v64, sigC.v0, sigZ.v64, sigZ.v0 );
                sigZExtra =
                    sig256Z[indexWord( 4, 1 )] | sig256Z[indexWord( 4, 0 )];
                if ( sigZExtra ) {
                    sigZ = softfloat_sub128( sigZ.v64, sigZ.v0, 0, 1 );
                }
                if ( ! (sigZ.v64 & UINT64_C( 0x0100000000000000 )) ) {
                    --expZ;
                    shiftCount = 7;
                }
                goto shiftRightRoundPack;
            } else {
                sig256C[indexWord( 4, 3 )] = sigC.v64;
                sig256C[indexWord( 4, 2 )] = sigC.v0;
                sig256C[indexWord( 4, 1 )] = 0;
                sig256C[indexWord( 4, 0 )] = 0;
                softfloat_sub256M( sig256C, sig256Z, sig256Z );
            }
        } else if ( ! expDiff ) {
            sigZ = softfloat_sub128( sigZ.v64, sigZ.v0, sigC.v64, sigC.v0 );
            if (
                ! (sigZ.v64 | sigZ.v0) && ! sig256Z[indexWord( 4, 1 )]
                    && ! sig256Z[indexWord( 4, 0 )]
            ) {
                goto completeCancellation;
            }
            sig256Z[indexWord( 4, 3 )] = sigZ.v64;
            sig256Z[indexWord( 4, 2 )] = sigZ.v0;
            if ( sigZ.v64 & UINT64_C( 0x8000000000000000 ) ) {
                signZ ^= 1;
                softfloat_sub256M( zero256, sig256Z, sig256Z );
            }
        } else {
            softfloat_sub256M( sig256Z, sig256C, sig256Z );
            if ( 1 < expDiff ) {
                sigZ.v64 = sig256Z[indexWord( 4, 3 )];
                sigZ.v0  = sig256Z[indexWord( 4, 2 )];
                if ( ! (sigZ.v64 & UINT64_C( 0x0100000000000000 )) ) {
                    --expZ;
                    shiftCount = 7;
                }
                goto sigZ;
            }
        }
        /*--------------------------------------------------------------------
        *--------------------------------------------------------------------*/
        sigZ.v64  = sig256Z[indexWord( 4, 3 )];
        sigZ.v0   = sig256Z[indexWord( 4, 2 )];
        sigZExtra = sig256Z[indexWord( 4, 1 )];
        sig256Z0  = sig256Z[indexWord( 4, 0 )];
        if ( sigZ.v64 ) {
            if ( sig256Z0 ) sigZExtra |= 1;
        } else {
            expZ -= 64;
            sigZ.v64  = sigZ.v0;
            sigZ.v0   = sigZExtra;
            sigZExtra = sig256Z0;
            if ( ! sigZ.v64 ) {
                expZ -= 64;
                sigZ.v64  = sigZ.v0;
                sigZ.v0   = sigZExtra;
                sigZExtra = 0;
                if ( ! sigZ.v64 ) {
                    expZ -= 64;
                    sigZ.v64 = sigZ.v0;
                    sigZ.v0  = 0;
                }
            }
        }
        shiftCount = softfloat_countLeadingZeros64( sigZ.v64 );
        expZ += 7 - shiftCount;
        shiftCount = 15 - shiftCount;
        if ( 0 < shiftCount ) goto shiftRightRoundPack;
        if ( shiftCount ) {
            shiftCount = -shiftCount;
            sigZ =
                softfloat_shortShiftLeft128( sigZ.v64, sigZ.v0, shiftCount );
            x128 = softfloat_shortShiftLeft128( 0, sigZExtra, shiftCount );
            sigZ.v0 |= x128.v64;
            sigZExtra = x128.v0;
        }
        goto roundPack;
    }
 sigZ:
    sigZExtra = sig256Z[indexWord( 4, 1 )] | sig256Z[indexWord( 4, 0 )];
 shiftRightRoundPack:
    sigZExtra = (uint64_t) (sigZ.v0<<(64 - shiftCount)) | (sigZExtra != 0);
    sigZ = softfloat_shortShiftRight128( sigZ.v64, sigZ.v0, shiftCount );
 roundPack:
    return
        softfloat_roundPackToF128(
            signZ, expZ - 1, sigZ.v64, sigZ.v0, sigZExtra );
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
 propagateNaN_ABC:
    uiZ = softfloat_propagateNaNF128UI( uiA64, uiA0, uiB64, uiB0 );
    goto propagateNaN_ZC;
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
 infProdArg:
    if ( magBits ) {
        uiZ.v64 = packToF128UI64( signZ, 0x7FFF, 0 );
        uiZ.v0 = 0;
        if ( expC != 0x7FFF ) goto uiZ;
        if ( sigC.v64 | sigC.v0 ) goto propagateNaN_ZC;
        if ( signZ == signC ) goto uiZ;
    }
 invalid:
    softfloat_raiseFlags( softfloat_flag_invalid );
    uiZ.v64 = defaultNaNF128UI64;
    uiZ.v0  = defaultNaNF128UI0;
 propagateNaN_ZC:
    uiZ = softfloat_propagateNaNF128UI( uiZ.v64, uiZ.v0, uiC64, uiC0 );
    goto uiZ;
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
 zeroProd:
    uiZ.v64 = uiC64;
    uiZ.v0  = uiC0;
    if ( ! (expC | sigC.v64 | sigC.v0) && (signZ != signC) ) {
 completeCancellation:
        uiZ.v64 =
            packToF128UI64(
                softfloat_roundingMode == softfloat_round_min, 0, 0 );
        uiZ.v0 = 0;
    }
 uiZ:
    uZ.ui = uiZ;
    return uZ.f;

}