GMP 4.4 remaining tasks
bodrato at mail.dm.unipi.it
bodrato at mail.dm.unipi.it
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...
Regards,
Marco
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http://bodrato.it/software/
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