Important

Loki is still under active development and has not yet seen a stable release. Interfaces can change at any time, objects may be renamed, or concepts may be re-thought. Make sure to sync your work to the current release frequently by rebasing feature branches and upstreaming more general applicable work in the form of pull requests.

Loki: Freely programmable source-to-source translation

[!IMPORTANT] This software is Incubating and subject to ECMWF’s guidelines on Software Maturity.

The Loki package is intended to explore the possible use of source-to-source translation for ECMWF’s Integrated Forecasting System (IFS) and associated Fortran software packages. It consists of a general code transformation API and a set of general transformations that may be applied to appropriate Fortran codes at build time via Python scripts or CMake macros.

Loki is based on compiler technology (visitor patterns and ASTs) and aims to provide an abstract, language-agnostic representation of a kernel, as well as a programmable (pythonic) interface that allows developers to experiment with different kernel implementations and optimizations. The aim is to allow changes to programming models and coding styles to be encoded and automated instead of hand-applying them, enabling advanced experimentation with large kernels as well as bulk processing of large numbers of source files to evaluate different kernel implementations and programming models.

Contact

Michael Lange (michael.lange@ecmwf.int), Ahmad Nawab (ahmad.nawab@ecmwf.int) Michael Staneker (michael.staneker@ecmwf.int)

License

Loki is distributed under the Apache License 2.0. In applying this licence, ECMWF does not waive the privileges and immunities granted to it by virtue of its status as an intergovernmental organisation nor does it submit to any jurisdiction.

Installation

See INSTALL.md.

Documentation

Loki has a comprehensive documentation that describes the API and how to use it to write custom transformations. There are also a number of Jupyter notebooks available in the example directory that help getting up to speed with the core functionality of the package.

Contributing

Contributions to Loki are welcome. Please read CONTRIBUTING.md before opening an issue or pull request. All participation in this project is governed by the Code of Conduct.