GNU bug report logs - #12350
Composites identified as primes in factor.c (when HAVE_GMP)

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Message #62 received at 12350 <at> debbugs.gnu.org (full text, mbox):

From: Paul Eggert <eggert <at> cs.ucla.edu>
To: Jim Meyering <jim <at> meyering.net>
Cc: 12350 <at> debbugs.gnu.org, nisse <at> lysator.liu.se,
	Torbjorn Granlund <tg <at> gmplib.org>
Subject: Re: bug#12350: Composites identified as primes in factor.c (when
	HAVE_GMP)
Date: Thu, 06 Sep 2012 17:22:22 -0700

On 09/06/2012 02:33 PM, Jim Meyering wrote:
>> > * We have some hardwired W_TYPE_SIZE settings for the code interfacing
>> >   to longlong.h.  It is now 64 bits.  It will break on systems where
>> >   uintmax_t is not a 64-bit type.  Please see the beginning of
>> >   factor.c.
> I wonder how many types of systems would be affected.

It's only a matter of time.  GCC already supports 128-bit
integers on my everyday host (Fedora 17, x86-64, GCC 4.7.1).
Eventually uintmax_t will grow past 64 bits, if only for the
crypto guys.

If the code needs exactly-64-bit unsigned integers, shouldn't
it be using uint64_t?  That's the standard way of doing
that sort of thing.  Gnulib can supply the type on pre-C99
platforms.  Weird but standard-conforming platforms that
don't have uint64_t will be out of luck, but surely they're out
of luck anyway.

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