Integer exponentiation without modulo?
fxcoudert at gmail.com
Sun Mar 18 12:17:35 CET 2007
> If b is larger than an unsigned long int (which is at least 32 bits
> in size (I believe 64 bits in a 64-bit system), hence it can store
> an integer as large as 4294967295), that means you're computing a
> number larger than b^4294967295, which even for the smallest choice
> of base b = 2 is already 4 Gbits in size -- assuming optimal
> storage. Are you really really sure you want to perform arithmetic
> with numbers this large? Maybe you should reevaluate whatever it is
> that you're doing.
I just wanted to write generic code without having to care about
limits and special-casing b = -1, b = 0 and b = 1. I ended up doing
just that, anyway.
Thanks for the answer,
More information about the gmp-discuss