returns the maximum of two ints without a comparison operator

max.c

#define INT_MIN 1 << (sizeof(int)*8 - 1)

int max(int a, int b) {
    unsigned int ua = (unsigned int) a - INT_MIN;
    unsigned int ub = (unsigned int) b - INT_MIN;

    int k = ((ub-ua) >> (sizeof(int)*8 - 1)) & (0x1);

    return k*a + (1-k)*b;
}