Steve,
I don't know if there is an actual statement to the effect that
the upper bound on a loop would be a register-sized number (32
or 64 bits) but at 6Mhz it seemed impossible that one could
run a loop of any consequence for greater than 2^32 or 2^64
iterations. If you wanted to do that you'd have to do the
looping using some other construct. In general it is safe to
assume that the upper bound of the register size cannot be
exceeded. There is a practical performance difference to
be gained by using (declare (fixnum as the compiler can,
in the best case, assign a register to the loop variable.
t