Am 27.04.2016 um 17:37 schrieb Rainer Orth: > Bernd Edlinger <bernd.edlin...@hotmail.de> writes: > >> On 26.04.2016 22:14, Joseph Myers wrote: >>> On Tue, 26 Apr 2016, Bernd Edlinger wrote: >>> >>>> Hi, >>>> >>>> as we all know, it's high time now to adjust the minimum supported >>>> gmp/mpfr/mpc versions for gcc-7. >>> >>> I think updating the minimum versions (when using previously built >>> libraries, not in-tree) is only appropriate when it allows some cleanup in >>> GCC, such as removing conditionals on whether a more recently added >>> function is available, adding functionality that depends on a newer >>> interface, or using newer interfaces instead of older ones that are now >>> deprecated. >>> >>> For example, you could justify a move to requiring MPFR 3.0.0 or later >>> with cleanups to use MPFR_RND* instead of the older GMP_RND*, and >>> similarly mpfr_rnd_t instead of the older mp_rnd_t and likewise mpfr_exp_t >>> and mpfr_prec_t in fortran/. You could justify a move to requiring MPC >>> 1.0.0 (or 1.0.2) by optimizing clog10 using mpc_log10. I don't know what >>> if any newer GMP interfaces would be beneficial in GCC. And as always in >>> such cases, it's a good idea to look at e.g. how widespread the newer >>> versions are in GNU/Linux distributions, which indicates how many people >>> might be affected by an increase in the version requirement. >>> >> >> Yes I see. >> >> I would justify it this way: gmp-6.0.0 is the first version that does >> not invoke undefined behavior in gmp.h, once we update to gmp-6.0.0 >> we could emit at least a warning in cstddef for this invalid code. >> >> Once we have gmp-6.0.0, the earliest mpfr version that compiles at all >> is mpfr-3.1.1 and the earliest mpc version that compiles at all is >> mpc-0.9. This would be the supported installed versions. >> >> In-tree gmp-6.0.0 does _not_ work for ARM. But gmp-6.1.0 does (with a >> little quirk). All supported mpfr and mpc versions are working in-tree >> too, even for the ARM target. >> >> When we have at least mpfr-3.1.1, it is straight forward to remove the >> pre-3.1.0 compatibility code from gcc/fortran/simplify.c for instance. >> >> So I would propose this updated patch for gcc-7. > > would this version combo (gmp 6.0.0, mpfr 3.1.1, mpc 0.9) also work on > the active release branches (gcc-5 and gcc-6, gcc-4.9 is on it's way > out)? Having to install two different sets of the libraries for trunk > and branch work would be extremely tedious. > > Rainer >
Yes, when they are pre-installed there should be no problem. Also newer versions than these seem to work. In-tree only the versions that download_prerequisite picks are tested and guaranteed to work.
