Compilers

On the cluster we offer several C/C++/Fortran compilers through our modules system.

Below is given a short introduction to these and a few tips on how best to utilise them.

GNU Compiler Collection

Intel Compiler Suite

Portland Group Compiler Suite

The best resource on using any of the PGI compilers is by reading their user guide, which can be found at http://www.pgroup.com/resources/docs.htm.

Advice and Tips

Compiler Flags

The PGI developers recommend that a few key flags be active for all compilations, specifically -fast -Mipa=fast,inline. The reasons for this and other details can be found on https://www.pgroup.com/support/compile.htm.

User Configurations

The PGI compiler suite has a default set of configurations that it uses when first loaded. These can be altered, or new configurations added. The main benefit of this is that certain compilation stages can be influenced in ways which are not covered by command line arguments.

These configurations can be set by creating and inserting the configuration settings into the appropriate RC file within your home directory. The name of such a file must be of the format .<compilerbin>rc, e.g. for pgcc the RC file is .pgccrc.

For example, PGI does not support the -pthread flag, and will error out if it encounters this flag. For some situations, using the -lpthread flag would be the solution - but other situations do not allow you to make this change. Instead, a filter can be set within the PGI configuration which checks for the -pthread flag and replaces it with the -lpthread flag. The configuration to achieve this is switch -pthread is replace(-lpthread) positional(linker);.