GNU MPFR version 3.1.4 (released on 6 March 2016)

[download] [documentation] [bugs] [changes] [platforms] [timings of 3.1.2]

The canard à l'orange release, patch level 4.

MPFR 3.1.4 requires GMP 4.1.0 or higher (GMP 4.2.3 or higher is recommended).

Warning! Due to the fact that Thread Local Storage (TLS) support is now detected automatically, the MPFR build can be incorrect on some platforms (compiler or system bug). Indeed, the TLS implementation of some compilers/platforms is buggy, and MPFR cannot detect every problem at configure time. Please run make check to see if your build is affected. If you get failures, you should try the --disable-thread-safe configure option to disable TLS and see if this solves these failures. But you should not use an MPFR library with TLS disabled in a multithreaded program (unless you know what you are doing).


The MPFR 3.1.4 source can be downloaded in the following archive formats:

Each tarball is signed by Vincent Lefèvre. This can be verified using the DSA key ID 98C3739D; this key can be retrieved with:

gpg --recv-keys 98C3739D

or by downloading it from The key fingerprint is:

07F3 DBBE CC1A 3960 5078  094D 980C 1976 98C3 739D

The signatures can be verified with:

gpg --verify file.asc

You should check that the key fingerprint matches.

MPFR is also available via third-party packages and ports.



The bugs listed below have been fixed (latest update: 2016-05-22). The patches are distributed under the same license as this version of MPFR, that is, the GNU Lesser General Public License (GNU Lesser GPL), version 3 or later.

The following instructions are for Linux and may be similar for other operating systems. You can apply the patches in several ways:

With the first two ways, the PATCHES file is modified, so that one can know what patches have been applied, using the new mpfr_get_patches function. Moreover a suffix is added to the version string, but note that for practical reasons, not all the files where the version appears are patched; thus one can also track applied patches with the MPFR_VERSION_STRING macro (header) and the mpfr_get_version function (library). However, if some patches are not applied or if patches are applied in a different order, then the patch command will fail to update some chunks, so that the suffix is not always reliable for patches.

Note: These patches are in unified diff format and some vendors' patch commands cannot deal with them; in this case, please use GNU patch (it may already be installed on your system, e.g. as /usr/local/bin/patch or gpatch).

Fixed bugs, with patches:

  1. Compilation can fail under Microsoft Windows if the __unix__ macro is defined. This problem occurs in particular with the 32-bit Cygwin. This is due to consistency checks added for MPFR 3.1.4 (useful mainly for the developers). This is fixed by the unix-check patch, which just removes these checks (this is OK for the 3.1 branch, which should now be stable enough, and in the trunk, the status of some macros are output by tversion to replace these checks).
    Corresponding changeset in the 3.1 branch: 10264.
  2. Functions mpfr_add_ui and mpfr_sub_ui do not set all the expected flags; in practice, this concerns only the NaN flag. This bug is fixed by the add-sub-ui-flags patch, which also provides test cases.
    Corresponding changeset in the 3.1 branch: 10304.

See the tracker and the BUGS file.

Changes from version 3.1.3 to version 3.1.4

Platforms Known to Support MPFR

MPFR 3.1.4 has been successfully compiled and checked on the following platforms:

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