The classical hashing way of hashing a number is keeping it as the reminder of the division with two distinct prime numbers i.e. hash(X) = (X mod prime1, X mod prime2), same thing with strings (considering them as polynomials). But modulo is a very heavy operation, and using a power of 2 (e.g. 2^64, using unsigned long long overflow) instead of a prime number fails when you hash a Thue-Morse sequence, so... Do you know any way of replacing the modulo with a smart bitwise operation or something else? I'd find it extremely useful :)