OpenMP Support

If installing pygram11 from conda-forge, OpenMP is available. If using PyPI or a source release, the setup.py script tests to see of OpenMP is available during installation.

Three platforms have been manually tested for OpenMP support (to not worry about this, just use conda-forge):

  • Arch Linux: system python (3.7.2) and GCC (8.2).
  • Debian Buster: system python3 (3.7.2) with GCC 8.3 and libgomp1 installed.
  • macOS 10.14: Homebrew python3 (3.7.2) with libomp installed from Homebrew (Apple LLVM version 10.0.0). Also (not conda-forge) Anaconda python3 (3.6.8 and 3.7.2) and python2 (2.7.15) distributions with libomp installed from Homebrew (you’ll likely need to remove the extra libiomp5.dylib from the Anaconda environment lib folder or conda install nomkl, see here).

To check if OpenMP was detected and used while compiling the extension module pygram11._core, try the following:

>>> import pygram11
>>> pygram11.OPENMP
True

Needless to say, if you see False OpenMP acceleration isn’t available.

The histogramming functions use a named argument for requesting OpenMP usage. If pygram11.OPENMP is False then the argument is ignored by the C++ code.