HPF and MPI Implementation of the NAS Parallel Benchmarks Supported by Integrated Program Engineering Tools

High Performance Fortran (HPF) compilers and communication libraries with the standardized Message Passing Interface (MPI) are becoming widely available, easing the development of portable parallel applications on distributed-memory parallel processor systems. The recently developed Annai tool environment supports programming, debugging and tuning of both HPFand MPI-based applications. Considering code development and subsequent maintenance time to be as important as ultimate performance, we address how sequential Fortran-77 versions of the familiar NAS Parallel Benchmark kernels can be expediently parallelized with appropriate tool support. While automatic parallelization of scientific applications written in traditional sequential languages remains largely impractical, Annai provides users with high-level language extensions and integrated program engineering support tools. In this paper, Annai support is demonstrated primarily focusing on the MG (multigrid) kernel, with complementary examples selected from the other four kernels. Respectable performance and good scalability in most cases are obtained with this straightforward parallelization strategy, even without recourse to platformspecific optimizations or major program transformations.