Off topic 'C' question

I have a quick question. What is the quickest way to determine
the next highest power of two which is greater than a given
integer in 'C'. For example, given the number 7, I would like to
return 8. Given the number 13, I would like to return 16, etc. Is
there a gem to do this without shifting a bit value from 1 left
up to a maximum of 32 (or 64) iterations? 

Thanks for any info, 

Mike Mascari