Micro-GMP

[paul zimmermann]

       Dear Marco,

> A attach a possible implementation of mini-gmp that should support limbs
> of "any" size. Can you test it with MPFR? Both correctness and speed...

it passes all MPFR tests, both with uint16 and uint8. It is also faster than
micro-gmp (I disabled GMP_CHECK_RANDOMIZE so that the tests are deterministic):

                micro-gmp           mini-gmp patched
           tdiv        tcos          tdiv       tcos
uint16     2.8s        7m25s         2.2s       4m45s
uint8      7.1s       21m40s         3.8s       7m26s

Great, thank you!
Paul

PS: it would be nice to indicate in mini-gmp.h the places to modify to enable
16-bit or 8-bit limbs.