30 Jan
2009
30 Jan
'09
5:41 p.m.
Marc,
(Not directly related) At some point I was wondering whether the special representation of 0 (size==0) should be extended to represent instead small numbers that can fit in an integer at most as long as _mp_d. Hard to tell.
an alternate trick is to store in the mpz_t *pointer* a value of the form p=2k+1, where k is a small integer. Since pointers are usually even, you can easily distinguish between small integers and GMP integers, and you obtain the value k = p >> 1. It is also more memory-efficient since you don't allocate the mpz_t structure. A famous computer algebra system is using that trick together with GMP.
It might make sense to have another layer on top of mpz with that trick.
Paul Zimmermann