Hi all,
As a learning exercise, I am experimenting in chess/alpha-beta search/bitboards. In this domain lot of bitwise operations are required. My goal is to keep learning scheme and Gambit, therefore I will be happy to stay with what I have right now if the only option is to switch to C et similia.

I am asking here for an advice in improving runtime speed crunching bitwise operations on u64 integers since I have no experience using scheme and Gambit.
Looking at the documentation I see that fixnum is providing some help but I apparently u64 integers are not "compatible" with fixnum operations

> (fixnum? 18446744073709551615)
#f

Can you share suggestions for my next exercise?
Thank you in advance

Paolo