__int64 _andn_u64 (unsigned __int64 a, unsigned __int64 b)

dst[63:0] := ((NOT a[63:0]) AND b[63:0])

long long calc_andn_u64 (long long src1,
			 long long src2,
			 long long dummy)
{
  return (~src1 + dummy) & (src2);
}