GMP 4.4 remaining tasks

bodrato at bodrato at
Tue Dec 8 12:45:24 CET 2009

>>    We should realise of course that mpn_bc_mulmod_bnm1 will be called
>>    just once and that mpn_bc_mulmod_bnp1 will be called once for small n
>>    and zero times for large n.
> I don't agree with the "zero times" part. mulmod_bnp1 is called
> multiple times, for various sizes. E.g., with a basecase threshold
> around 20 (for bnm1),

Yes, bnm1 is called once for any recursion level. And basecase is called
for all the sizes where FFT can not be used.

> One might also consider writing wrapping Karatsuba multiplication, maybe
> one can save one addition there. But I would expect a modest saving, at

I did some test with a Karatsuba_mod_bnp1. IIRC one saves half an addition
(wrt toom22 that already saves the other half :-) and I was not able to
measure any saving...



More information about the gmp-devel mailing list