统计一个32位数的1的个数

unsigned int GetNumCount(unsigned int  i4Num)
{
  int i;
  unsigned int i4Cnt = 0;
  int tmp;
  for(i = 0 ;i<32; i++)
  {
     i4Cnt = i4Cnt +((i4Num & (1<<i))>>i);
  }
 
  return i4Cnt;
 
}