GNU MPFR version 4.2.1 (released on 22 August 2023)

The fondue savoyarde release, patch level 1.

MPFR 4.2.1 requires GMP 5.0 or higher.

Note: the bug-fix release MPFR 4.2.2 is available. Please upgrade!

Download

The MPFR 4.2.1 source can be downloaded in the following archive formats:

• mpfr-4.2.1.tar.xz (tar/xz, 1.5 MB, signature),
• mpfr-4.2.1.tar.bz2 (tar/bzip2, 1.7 MB, signature),
• mpfr-4.2.1.tar.gz (tar/gzip, 2.2 MB, signature),
• mpfr-4.2.1.zip (zip, 2.6 MB, signature).

Each tarball is signed by Vincent Lefèvre. This can be verified using the DSA key ID 5831D11A0D4DB02A; this key can be retrieved with:

gpg --recv-keys 5831D11A0D4DB02A

or by downloading it from https://www.vinc17.net/pgp.html. The key fingerprint is:

A534 BE3F 83E2 41D9 1828  0AEB 5831 D11A 0D4D B02A

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.

Documentation

• The reference manual: [html] [dvi] [ps] [pdf]
• The MPFR FAQ (common to all MPFR versions).

Bugs

The bugs listed below have been fixed (latest update: 2025-03-07). 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:

• Apply the cumulative patch on the 4.2.1 release or a partially patched version with the commands

  patch -N -p1 < path_to_patches_file
  touch aclocal.m4
  touch Makefile.in
  touch configure

  from the source directory, in this order. The -N option allows the patch command to ignore patches already applied. Because make's rebuild decisions are based on timestamps, and in particular because the acinclude.m4 file is patched, the timestamps of aclocal.m4, Makefile.in and configure need to be updated with the above commands to avoid the need of the autotools. Alternatively, the --disable-maintainer-mode configure option could be used later. Under Microsoft Windows, in addition to the above patch options, you may need the --binary option (this depends whether the end-of-lines have been converted when you downloaded the patch file). Also note that the --dry-run option does not work if the cumulative patch has some file listed several times.
• Or apply the individual patches below (but see above concerning the timestamps).
• Or checkout the 4.2 branch from the Git repository. In this case, as said on the MPFR Git page, you should read the README.dev file for details on how to build MPFR. Also note that the branch may contain additional minor fixes.

With the first two ways, the PATCHES file is modified, so that one can know what patches have been applied, using the 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. The configure script fails with Clang and the GNU C Library (glibc) 2.41 due to code related to binary128 support (a.k.a. float128). Other platforms and build tools may be affected. The cause is the following. If the configure script detects that _Float128 is not supported by the compiler, but that __float128 is supported, then _Float128 is defined as __float128 (with a macro). However, the C library may introduce some support on its side (this is what glibc 2.41 does), conflicting with the MPFR code. Since _Float128 is a reserved identifier, a different solution is needed. What has been chosen is to use a mpfr_float128 macro defined as _Float128 by default, and the prototypes now use mpfr_float128 instead of _Float128; thanks to the default definition, this changes neither the ABI nor the API. See the updated MPFR manual for additional details and instructions for the end user. This is fixed by the float128 patch.
   Corresponding changesets in the 4.2 branch: 510f0971d, 023f69526

See the BUGS file. The Reporting Bugs section of the MPFR manual gives details on how to report new bugs.

Other bugs fixed in the 4.2 branch:

• The formatted output functions behave incorrectly with %c on the value 0. Such a use is uncommon, but this bug may have security implications.
  Corresponding changesets in the 4.2 branch: 6061dcfbb, 154c11b26.
  The new tests may fail on some platforms (such as Microsoft Windows), but the cause is probably not the (patched) MPFR code; this will be investigated.

Changes from version 4.2.0 to version 4.2.1

• Bug fixes (see the fixed bugs on the MPFR 4.2.0 page and/or the ChangeLog file).
• Improved MPFR manual.
• Configure tests: replaced the test of the link with GMP, in order to avoid the use of a function without a prototype (Autoconf issue), as this is obsolescent in ISO C. The new test should be more robust.

Platforms Known to Support MPFR

MPFR 4.2.1 has been successfully compiled and checked on the following platforms:

• aarch64-apple-darwin21.6.0 (clang 14.0.0);
• aarch64-unknown-linux-gnu (gcc 8.5.0 and 12.2.0, clang 16.0.6 on Termux/Android, tcc mob branch);
• armv7l-unknown-linux-gnueabihf (gcc 13.2.0);
• i686-w64-mingw32 (Wine, gcc 12-win32);
• ia64-unknown-linux-gnu (gcc 13.2.1);
• mips-unknown-linux-gnu (o32 and n32 ABI, gcc 8.3.0);
• mips64-unknown-openbsd7.3 (OpenBSD 7.3, clang 13.0.0);
• powerpc-ibm-aix7.3.1.0 (IBM POWER8, gcc 10.3.0);
• powerpc64-unknown-linux-gnu (IBM POWER7, gcc 4.8.5);
• powerpc64le-unknown-linux-gnu (IBM POWER8, gcc 4.8.5; IBM POWER9, gcc 4.8.5 and 8.3.1, IBM XL C/C++ 16.1.1.3);
• riscv64-unknown-freebsd14.0 (clang 16.0.6);
• sparc-sun-solaris2.8 (gcc 4.5.1);
• sparc-sun-solaris2.9 (gcc 4.6.4);
• sparc-sun-solaris2.10 (gcc 5.5.0);
• sparc64-unknown-linux-gnu (gcc 12.3.1);
• x86_64-pc-linux-gnu (gcc 4.8.5, 4.9.4, 5.5.0, 6.5.0, 8.4.0, 9.5.0, 10.5.0 and 13.2.0, g++ 4.9 and 13.2.0, clang 3.6.2, 3.7.1, 6.0.1, 7.0.1, 8.0.1, 9.0.1, 10.0.1, 11.1.0, 12.0.1, 13.0.1, 14.0.6, 15.0.7 and 16.0.6, Intel oneAPI icx 2021.3.0, and tcc 0.9.27).

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