zn_poly: C library for polynomial arithmetic in Z/nZ[x]


zn_poly is a C library for polynomial arithmetic in Z/nZ[x], where n is any modulus that fits into an unsigned long.

Website: https://gitlab.com/sagemath/zn_poly

Note: Original website is at https://web.maths.unsw.edu.au/~davidharvey/code/zn_poly/ but is no longer maintained. Sage maintains an “official” continuation of the project at the above link.


GPL V2 or V3. Some of the code has been copied from other projects - see the file src/COPYING for details.

Upstream Contact



  • (some) Python (to create the Makefile)

  • GNU patch

  • NTL apparently only if we configured zn_poly differently (same for FLINT)

Special Update/Build Instructions

  • Make sure the patches still apply.

    Especially changes in makemakefile.py may also require changes to spkg-install (and perhaps also spkg-check).

  • There’s also a --use-flint option to configure; no idea what it does, and we currently don’t use it either.

  • TODO:

  • Use make install instead of manually “installing” (copying and symlinking) the [shared] libraries and header files. This requires further tweaking of makemakefile.py, since it currently only installs a static library and the headers.

  • If everything’s fine, i.e., no problems arise, some comments and especially some code I currently just commented out can certainly be removed. (-leif, 04/2012)

  • The version number “0.9.p11” is used as a doctest in the function package_versions in sage/misc/packages.py, so if this package gets upgraded, that doctest needs to be changed.


  • All patches from Sage have been merged into upstream. These include:

  • makemakefile.py.patch:

    Improves the Python script creating the Makeefile for better use at least within Sage; see patch for details. (Last modified at #12433, which added and changed a lot.)

  • profiler.c.patch, zn_poly.h.patch:

    Fix potential redefinition of ulong (in combination with other headers).

  • mpn_mulmid-tune.c.patch, mulmid-tune.c.patch, mul-tune.c.patch:

    Fix “jump into scope of identifier with variably modified type” errors. (See #8771).

  • mpn_mulmid-test.c.patch:

    Fix a potential problem when the value of ZNP_mpn_smp_kara_thresh is SIZE_MAX, this is usually irrealistic but can happen at least on linux on power7 with gcc-4.7.1 (see #14098).

  • fix_fudge_factor_in_nuss-test.c.patch:

    As the name says; fix provided by upstream (David Harvey); see #13947.



Version Information



Equivalent System Packages


$ sudo pacman -S  zn_poly


$ conda install zn_poly


$ sudo apt-get install  libzn-poly-dev


$ sudo yum install  zn_poly zn_poly-devel


$ sudo pkg install math/zn_poly


$ nix-env --install zn_poly


$ sudo zypper install zn_poly-devel


$ sudo xbps-install  zn_poly

See https://repology.org/project/zn-poly/versions, https://repology.org/project/libzn-poly/versions

If the system package is installed, ./configure will check whether it can be used.