PSyTran: tools for automating OpenACC GPU porting efforts using PSyclone

Introduction

Before introducing PSyTran, we should introduce PSyclone. PSyclone is a domain-specific compiler and code transformation tool for earth system codes written in Fortran. In code transformation mode (which is of main interest here), PSyclone can be used to read in Fortran source code, along with a user-defined transformation script (written in Python), which describes modifications to be made to the source code. With these two ingredients, PSyclone converts the source code to its internal intermediate representation, applies the transformations, and then writes out the modified code.

One key example of a transformation to be applied to the input code is to insert OpenACC directives and clauses. Compiled under NVHPC, the OpenACC syntax tells the compiler how to parallelise the code on Nvidia GPUs. This is the transformation of primary interest as far as PSyTran goes.

PSyTran is a Python package which provides various helper functions for PSyclone, particularly with regards to writing transformation scripts for OpenACC GPU porting. Amongst other things, PSyTran provides functionality for:

• simplifying tree traversal in PSyclone's intermediate representation,
• analysing the structure of loops and loop nests,
• applying OpenACC kernels and loop directives,
• applying OpenACC clauses to loop directives,
• querying Node types.

General user instructions

Instructions for installing PSyTran and building and viewing its documentation may be found on the Wiki page.

Developer notes

Contributions are very welcome! However, please read PSyTran's Coding Practices before commencing development work.

When you make your first contribution, make sure to add yourself to the contributors list.