Finding performance bugs with the TNO HPF benchmark suite

HPF has been designed to provide portable performance on distributed memory machines. An important aspect of portable performance is the behavior of the available HPF compilers. Ideally, a programmer may expect comparable performance between different HPF compilers, given the same program and the same machine. To test the performance portability between compilers, we have designed a special benchmark suite, called the TNO HPF benchmark suite. It consists of a set of HPF programs, that test various aspects of efficient parallel code generation. The benchmark suite consists of a number of template programs that are used to generate test programs with different array sizes, alignments, distributions, and iteration spaces. It ranges from very simple assignments to more complex assignments like triangular iteration spaces, convex iteration spaces, coupled subscripts, and indirection arrays. We have run the TNO HPF benchmark suite on three compilers: the PREPARE prototype compiler, the PGI-HPF compiler, and the GMD Adaptor HPF compiler. Results show performance differences that can be quite large (up to two orders of magnitude for the same test program). Closer inspection reveals that the origin of most differences in performance is due to differences in local enumeration and storage of distributed array elements.