Re: [Patch] Bump minimum required MPFR version

[Janne Blomqvist <blomqvist dot janne at gmail dot com>]

On Sun, May 6, 2012 at 2:39 PM, Richard Guenther
<richard.guenther@gmail.com> wrote:
> On Sun, May 6, 2012 at 10:33 AM, Janne Blomqvist
> <blomqvist.janne@gmail.com> wrote:
>> Hi,
>>
>> in http://gcc.gnu.org/install/prerequisites.html we say that GCC
>> requires at least MPFR 2.4.2, but in the toplevel configure.ac we only
>> require 2.3.1, printing a warning that the result is likely to be
>> buggy if the version is lower than 2.4.2.
>>
>> The attached patch bumps the minimum version to 2.4.0. We started
>> requiring 2.3.1, which was released on 2008-01-29, on 2009-04-08, that
>> is, about 1 year and a few months after the release. MPFR 2.4.0 was
>> released on 2009-01-26, so by now it's 3 years old. And by the time we
>> release 4.8 it's most likely over 4 years old already.
>>
>> For some background, the fortran frontend recently started using
>> mpfr_fmod to fix some bugs in the constant folding of the MOD and
>> MODULO intrinsics, effectively requiring at least MPFR 2.4.0 in order
>> to build.
>>
>> Also, if this patch is accepted the middle-end could be modified to
>> constant fold BUILT_IN_FMOD{F,,L} relatively easily, something which
>> isn't done today.
>>
>> Ok for trunk?
>
> Please make the check match documentation, thus 2.4.2, not 2.4.0.

Something like the attached patch? FWIW, this removes the distinction
we have between "buggy, but builds" and "ok".

Ok for trunk?

2012-05-06 ÂJanne Blomqvist Â<jb@gcc.gnu.org>

   Â* configure.ac: Bump minimum MPFR version to 2.4.2.
   Â* configure: Regenerated.



-- 
Janne Blomqvist

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