//Method 1
int count = __builtin_popcount(number);
//Method 2
int count = 0;
while (number) {
count += number & 1;
n >>= 1;
}
//Method 1
int count = 0;
while (n)
{
count++;
n >>= 1;
}
//Method 2
int count = (int)log2(number)+1;