----- Original Message ----- From: "Christoph Ludwig" <cludwig@cdc.informatik.tu-darmstadt.de>
Hi,
There is not much special about my library. Like the gmp, this library uses expression templates to avoid the creation of temporary values, which when the values become large provide an increase in performance.
I sometimes wonder whether a bigint library that implements move semantics could not provide an additional significant efficiency gain. (Since I can avoid temporaries most of the time, my applications don't profit from expression templates that much.) I never performed experiments, though, this is only a conjecture.
Do you have any plans in this direction?
What would implementing move semantics look like? Do you mean that an expression like x = y * z where y and z aren't used after this expression can be implemented as a swap(x, y); x *= z? I'm not sure how to implement it, but if a method exists which provides a significant efficiency gain and does not interfere with the interface too much, then I'm certainly interested in implementing it.
Once the interface matures, I want to make the library be able to use other arbitrary magnitude libraries to perform high-speed calculations.
Hm, I "inherited" some time ago the task to maintain a computer algebra library that can be built on top of several bigint libraries. Since these libraries are optimized for different use cases and this fact shows in their respective interfaces, it is hard to come up with a wrapper that does neither favour one particular library nor pulls all libraries down to their least common denominator.
My idea was to delegate the simple operations +, -, * etc. to the other libraries, like gmp. This makes the speed of the library higher in the case such a library is installed, but does not give me the burden of coding really efficient versions of those operators myself. The big integer library will remain a reasonably general-purpose integer library. I do not intend to make this library cover every area where large integers are needed, but I want to provide a reasonable library for average integer calculations. I intend to use this library for cryptographic algorithms, where I want decent performance, but also a simple intuitive interface. Therefore, I would like a 'normal' library where the backend is adapted to the frontend, and not the other way around. Best regards, Richard Peters