On Sun, May 6, 2012 at 7:24 PM, Janne Blomqvist <blomqvist.ja...@gmail.com> wrote: > On Sun, May 6, 2012 at 2:39 PM, Richard Guenther > <richard.guent...@gmail.com> wrote: >> On Sun, May 6, 2012 at 10:33 AM, Janne Blomqvist >> <blomqvist.ja...@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?
The change that bumped the documented requirement was logged with +2010-01-31 Kaveh R. Ghazi <gh...@caip.rutgers.edu> + + * doc/install.texi: Update recommended GMP/MPFR/MPC versions. which suggests a recommended version. So I'd revert my earlier comment and if 2.4.0 builds ok then we should check for that version instead. Thus, the earlier patch is ok. Thanks, Richard. > 2012-05-06 Janne Blomqvist <j...@gcc.gnu.org> > > * configure.ac: Bump minimum MPFR version to 2.4.2. > * configure: Regenerated. > > > > -- > Janne Blomqvist