Evaluation of compiler and runtime library approaches for supporting parallel regular applications

Important applications including those in computational chemistry, computational fluid dynamics, structural analysis and sparse matrix applications usually consist of a mixture of regular and irregular accesses. While current state-of-the-art run-time library support for such applications handles the irregular accesses reasonably well, the efficacy of the optimizations at run-time for the regular accesses is yet to be proven. This paper aims to find a better approach to handle the above applications in a unified compiler and run-time framework. Specifically, this paper considers only regular applications and evaluates the performance of two approaches, a run-rime approach using PILAR and a compile-time approach using a commercial HPF compiler. This study shows that using a particular representation of regular accesses, the performance of regular code using run-time libraries can come close to the performance of code generated by a compiler. It also determines the operations that usually contribute largely to the run-time overhead in case of regular accesses. Experimental results are reported for three regular applications on a 16-processor IBM SP-2