Re: [boost] [mp_math] a multi precision signed integer library

From: Stephen Nuchia (snuchia_at_[hidden])
Date: 2008-03-31 14:59:48

In large-scale computation code, fine control of allocation is a must.
The ability to have the major data structures with their hand-tuned
allocation strategies freely intermix with "casual" variables and
constants in expressions, as parameters, etc is pretty important.

Bleeding-edge factorization algorithms for instance allocate large
numbers of, uhm, numbers all of which have roughly the same number of
bits.  Cache-and-paging efficient allocation for these numbers can make
the difference between success and failure.  But you'd like to be able
to call functions that were written without awareness of your custom
allocation strategy.

The concerns for both interoperability and efficiency are inescapable.
I believe the interface should allow for runtime polymorphism but be
constructed so that a decent optimizing compiler can "almost always"
infer the correct static call in code that is not intentionally using
runtime polymorphism.  That may take some template specializations but
it would be worth it.

Finally, how does this relate to gmp?  Are we trying to work around
licensing issues or is it an interface definition issue?  Where the user
has a tested and tuned gmp implementation, can the new library be
configured as a wrapper for it?