Is there any way to write “mod 31” without modulus/division operators?

Question

Getting the modulus of a number can be easily done without the modulus operator or divisions, if your operand is a power of 2. In that case, the following formula holds:

Answer 1

int mod31(int a){
    while(a >= 31) {
        a -= 31;
    }
    return a;
};

It works if a > 0, but I doubt it will be faster than % operator.