2.78

/*
 * divide-power2.c
 */
#include <stdio.h>
#include <assert.h>
#include <limits.h>

/*
 * Divide by power of 2, -> x/2^k
 * Assume 0 <= k < w-1
 */
int divide_power2(int x, int k) {
  int is_neg = x & INT_MIN;
  (is_neg && (x = x + (1 << k) - 1));
  return x >> k;
}

int main(int argc, char* argv[]) {
  int x = 0x80000007;
  assert(divide_power2(x, 1) == x / 2);
  assert(divide_power2(x, 2) == x / 4);
  return 0;
}