2.65

/*
 * odd-ones.c
 */
#include <stdio.h>
#include <assert.h>

int odd_ones(unsigned x) {
  x ^= x >> 16;
  x ^= x >> 8;
  x ^= x >> 4;
  x ^= x >> 2;
  x ^= x >> 1;
  x &= 0x1;
  return x;
}

int main(int argc, char* argv[]) {
  assert(odd_ones(0x10101011));
  assert(!odd_ones(0x01010101));
  return 0;
}