HPF+: High Performance Fortran for advanced scientific and engineering applications

Abstract

High Performance Fortran (HPF) offers an attractive high-level interface for programming scalable parallel architectures by extending Fortran with directives for specifying data distributions and for indicating parallel execution. The current version of HPF is very well suited for regular codes but lacks important features required for an efficient parallelization of applications based on irregular grids or unstructured meshes. In this paper, we present an optimized version of high performance Fortran, called HPF+, that addresses these requirements. HPF+ provides data distribution features applicable in the context of irregular, dynamically changing data structures and access patterns. Additional mechanisms are introduced to influence the mapping of computations to processors and to reduce the runtime preprocessing and communication overheads of irregular loops. Without sacrificing required functionality, HPF+ adopts a data distribution model based on a one-level mapping of data to processors, reducing the complexity of the language, while alleviating the compiler’s task of producing an efficient parallel program.