If you're into bit hacks... Though K&R is on the shelf within reach and I knew it had a good algorithm for counting set bits (ones), I also remembered reading

If you're into bit hacks... Though K&R is on the shelf within reach and I knew it had a good algorithm for counting set bits (ones), I also remembered reading about a more efficient method a while back. The following page covers a number of set bit counting hacks: http://graphics.stanford.edu/~seander/bithacks.html http://graphics.stanford.edu/~seander/bithacks.html