int Count (unsigned int w) { w = (0x55555555 & w) + (0x55555555 & (w>> 1)); w = (0x33333333 & w) + (0x33333333 & (w>> 2)); w = (0x0f0f0f0f & w) + (0x0f0f0f0f & (w>> 4)); w = (0x00ff00ff & w) + (0x00ff00ff & (w>> 8)); w = (0x0000ffff & w) + (0x0000ffff & (w>>16)); return w; }