Tools-supported HPF and MPI parallelization of the NAS parallel benchmarks

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. The Annai tool environment supports programming, debugging and tuning of both HPF- and MPI-based applications. Considering code development time to be as important as final performance, we address how sequential 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. Respectable performance and scalability in most cases are obtained with this straightforward parallelization strategy on the NEC Cenju-3 distributed-memory parallel processor even without recourse to platform-specific optimizations or major program transformations.