compiling_code.rst

Compiling SWIFT

Dependencies

To compile SWIFT, you will need the following libraries:

HDF5

Version 1.8.x or higher is required. Input and output files are stored as HDF5 and are compatible with the existing GADGET-2 specification. Please consider using a build of parallel-HDF5, as SWIFT can leverage this when writing and reading snapshots. We recommend using HDF5 > 1.10.x as this is vastly superior in parallel.

MPI

A recent implementation of MPI, such as Open MPI (v2.x or higher), is required, or any library that implements at least the MPI 3 standard.

Running SWIFT on OmniPath atchitechtures with Open MPI

When running SWIFT on an OmniPath system we suggest that Open MPI v3.1.3 or higher is used. A bug in the psm2 library causes communications to be lost. It is possible to run SWIFT with older versions (tested with v2.1.x) of Open MPI so long as psm is used instead of psm2, i.e. that you invoke mpirun with --mca btl vader,self -mca mtl psm.

Libtool

The build system depends on libtool.

FFTW

Version 3.3.x or higher is required for periodic gravity.

METIS

METIS is used for domain decomposition and load balancing.

libNUMA

libNUMA is used to pin threads (but see INSTALL.swift).

GSL

The GSL is required for cosmological integration.

Optional Dependencies

There are also the following _optional_ dependencies.

TCmalloc/Jemalloc

TCmalloc/Jemalloc are used for faster memory allocations when available.

DOXYGEN

You can build documentation for SWIFT with DOXYGEN.

Python

To run the examples, you will need python and some of the standard scientific libraries (numpy, matplotlib). Some examples use Python 2 scripts, but the more recent ones use Python 3 (this is specified in individual READMEs).

GRACKLE

GRACKLE cooling is implemented in SWIFT. If you wish to take advantage of it, you will need it installed.

Initial Setup

We use autotools for setup. To get a basic running version of the code (the binary is created in swiftsim/examples) on most platforms, run

./autogen.sh
./configure
make

MacOS Specific Oddities

To build on MacOS you will need to disable compiler warnings due to an incomplete implementation of pthread barriers. DOXYGEN also has some issues on MacOS, so it is best to leave it out. To configure:

./configure --disable-compiler-warnings --disable-doxygen-doc

Trouble Finding Libraries

If the configure script is having trouble finding your libraries for you, it may be that they are in nonstandard locations. You can link the specific library locations by using --with-<LIBRARY>=<PATH>. For example for the HDF5 library,

./configure --with-hdf5=/path/to/h5cc

More information about what needs to be provided to these flags is given in ./configure --help.