Recent changes to mpn_get_str/mpn_set_str

Marco Bodrato bodrato at
Fri Jan 27 00:32:49 UTC 2017


Il Ven, 27 Gennaio 2017 12:27 am, Torbjörn Granlund ha scritto:
> "Marco Bodrato" <bodrato at> writes:
>   We may also try the division-free algorithm explored by
> Bouvier-Zimmermann
>   in their paper:

> I found the old code implementing the basecase.  This code is very
> likely the basis for the conclusion in the GMP manual where we say this
> is not an improvement.  (See the quote in the paper, section 2.2.)

Yes, they properly reference the source of the idea :-)

> I'll see if I can brush up the code and make use of it for machines with
> pipelined multiply.

If it extracts digits limb by limb, then progressively shorten the buffer
used by the mul_1 phase, I believe it will reach the performances claimed
by the two authors.

Unfortunately I do not have access neither to your old code nor to the
code of the two authors... and I won't write a third implementation from
scratch... not immediately at least :-)



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