Runtime Performance of Parallel Array Assignment: An Empirical Study

Generating code for the array assignment statement of High Performance Fortran (HPF) in the presence of block-cyclic distributions of data arrays is considered difficult, and several algorithms have been published to solve this problem. We present a comprehensive study of the run-time performance of the code these algorithms generate. We classify these algorithms into several families, identify several issues of interest in the generated code, and present experimental performance data for the various algorithms. We demonstrate that the code generated for block-cyclic distributions runs almost as efficiently as that generated for block or cyclic distributions.