public static void reduce(int[] xx, int[] z) { long cc = Nat160.mul33Add(PInv33, xx, 5, xx, 0, z, 0); int c = Nat160.mul33DWordAdd(PInv33, cc, z, 0); // assert c == 0 || c == 1; if (c != 0 || (z[4] == P4 && Nat160.gte(z, P))) { Nat.add33To(5, PInv33, z); } }