Re: time impact of the delta signature

On 23/02/2019 09:24, Denis Corbin wrote:
> Of course an approximate value of root mathematical functions is
> sufficient to answer the need. And as infinint type is just an integer
> type that has no limit (except the available memory resources) and that
> the shift left and right operations are already implemented, thus little
> remains to do to add the approximate square, cube, ... root functions! :)

By the way, it also occurred to me that infinint exp2 can easily be
optimised by a compile-time lookup table for the first N values (maybe
32 or 64) -- backed up by a generalised implementation for larger values
(maybe based on knowing the internal structure of infinint instead of
needing an actual shift loop).

In reality it may be easiest using the rs_long_sqrt algorithm pointed
out by andycapo for filesizes which do fit in a simple type and keeping
the log/exp algorithm for cases where the multiplications in the
rs_long_sqrt algorithm would require expensive infinint arithmetic.