because our bit-size is a power of to, 2^11, the CPU can optimize the operation as bit shifts along 64 or 32 bit wide segments of the number anyway, it is a false economy using a table of bitshifts, you can do it this way destructively, just like in my algorithm

the big number integer math library does not do anything complex for this operation, it's shift and overflow/underflow, because it's a power of 2