mul64To128
mul64To128( aSig, bSig, &zSig0, &zSig1 );
mul64To128( bSig, zSig, &term0, &term1 );
mul64To128( zSig, zSig, &term0, &term1 );
mul64To128( aSig, bSig, &zSig0, &zSig1 );
mul64To128( bSig, zSig0, &term0, &term1 );
mul64To128( bSig, zSig1, &term1, &term2 );
mul64To128( bSig, q, &term0, &term1 );
mul64To128( bSig, q<<( 64 - expDiff ), &term0, &term1 );
mul64To128( zSig0, zSig0, &term0, &term1 );
mul64To128( zSig0, zSig1, &term1, &term2 );
mul64To128( zSig1, zSig1, &term2, &term3 );
mul64To128(b, z, &term0, &term1);
mul64To128(bSig, zSig, &term0, &term1);
mul64To128(aSig, bSig, &zSig0, &zSig1);
void mul64To128(bits64 a, bits64 b, bits64 * z0Ptr, bits64 * z1Ptr);