Trasgo: a nested-parallel programming system

Abstract

Programming models of pure nested-parallelism are appealing due to their ease of programming and good analysis and debugging properties. Although their simple synchronization structure is appropriate to represent abstract parallel algorithms, it does not take into account many implementation issues. In this work we present Trasgo, a programming system based on high-level, nested-parallel specifications. We show how it allows to easily express complex combinations of data and task parallelism with a common scheme, hiding the layout and scheduling details. The approach allows the development of a modular compiler where automatic transformation techniques may exploit lower level and more complex synchronization structures, unlocking the limitations of pure nested-parallel programming. This article presents an overview of the features of Trasgo, and its architecture. We present some performance results using well-known parallel algorithms, and a roadmap of improvements and new features to be added to Trasgo.