code: function (m, n) {
        m = [m[0] >>> 16, m[0] & 0xffff, m[1] >>> 16, m[1] & 0xffff]
        n = [n[0] >>> 16, n[0] & 0xffff, n[1] >>> 16, n[1] & 0xffff]
        var o = [0, 0, 0, 0]
        o[3] += m[3] + n[3]
        o[2] += o[3] >>> 16
        o[3] &= 0xffff
        o[2] += m[2] + n[2]
        o[1] += o[2] >>> 16
        o[2] &= 0xffff
        o[1] += m[1] + n[1]
        o[0] += o[1] >>> 16
        o[1] &= 0xffff
        o[0] += m[0] + n[0]
        o[0] &= 0xffff
        return [(o[0] << 16) | o[1], (o[2] << 16) | o[3]]
      }
docs: Given two 64bit ints (as an array of two 32bit ints) returns the two added together as a 64bit int (as an array of two 32bit ints).