GAPS: A compiler framework for genetic algorithm (GA) optimised parallelisation

Abstract

The compilation of FORTRAN programs for SPMD execution on parallel architectures often requires the application of program restructuring transformations such as loop interchange, loop distribution, loop fusion, loop skewing and statement reordering. Determining the optimal transformation sequence that minimises execution time for a given program is an NP-complete problem. The hypothesis of the research described here is that GA techniques can be used to determine the sequence of restructuring transformations which are better, or, as good as, those produced by more conventional compiler search techniques. The Genetic Algorithm Parallelisation System (GAPS) compiler framework is presented. GAPS uses GA optimisation to determine the restructuring transformation applied to each statement and its associated iteration space. The hypothesis of GAPS is tested with an evaluation of the performance of SPMD code produced by GAPS on an SGI Origin 2000. Preliminary results indicate that this hypothesis is correct.