Program Optimization and Parallelization Using Idioms

Abstract

Programs in languages such as Fortran, Pascal, and C were designed and written for a sequential machine model. During the last decade, several methods to vectorize such programs and recover other forms of parallelism that apply to more advanced machine architectures have been developed 1994. We propose and demonstrate a more powerful translation technique for making such programs run efficiently on parallel machines which support facilities such as parallel prefix operations as well as parallel and vector capabilities. This technique, which is global in nature and involves a modification of the traditional definition of the program dependence graph (PDG), is based on the extraction of parallelizable program structures (“idioms”) from the given (sequential) program. The benefits of our technique extend beyond the above-mentioned architectures and can be viewed as a general program optimization method, applicable in many other situations. We show a few examples in which our method indeed outperforms existing analysis techniques. © 1994, ACM. All rights reserved.