Subject: Re: bug#12350: Composites identified as primes in factor.c (when HAVE_GMP)

From: [email-masked] (Niels Möller)
Date: Fri, 07 Sep 2012 12:35:32 +0200

Pádraig Brady <[email-masked]> writes:

> On 09/07/2012 09:43 AM, Niels Möller wrote:

>> If this is an important feature, maybe one should consider bundling
>> mini-gmp

> Bundling libraries is bad if one needed to update it.

mini-gmp is not an ordinary library. It's a single portable C source
file (currently around 4000 lines) implementing a subset of the GMP API,
and with performance only a few times slower than the real thing, for
"small bignums". It's *intended* for bundling with applications, either
for unconditional use, or for use as a fallback if the real gmp library
is not available. It's never (I hope!) going to be installed in
/usr/lib. To me, coreutil's factor seem to be close match for what it's
intended for.

That said, mini-gmp is pretty new (I wrote most of it around last
Christmas) and I'm not aware of any application or library using it yet.
I think the guile hackers are considering using it (for the benefit of
applications which use guile as an extension language, but don't need
high performance bignums).

So if you decide to use it in coreutils, you'll be pioneers.

It *is* used in the GMP build process, for precomputing various internal
tables.

Regards,
/Niels

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