Is there a way to get a bit's position in a datatype? For example, if int var1 = 64 how can I know that it is in position 7, or if var1 = 16 that it is in position 5, or any position in the 32 bit word (there will only be 1 bit set at a time)?

I would like to get this preferably without calling a squareroot function (hopefully using just bit operators). Computing this index needs to be as fast as possible as I will have to do this countless times on 384 bits at a time.

Thanks for your help,