Language Extensions in Support of Compiler

Abstract. In this paper, we propose an approach to automatic com-piler parallelization based on language extensions that is applicable to a broader range of program structures and application domains than in past work. As a complement to ongoing work on high productivity lan-guages for explicit parallelism, the basic idea in this paper is to make se-quential languages more amenable to compiler parallelization by adding enforceable declarations and annotations. Specifically, we propose the addition of annotations and declarations related to multidimensional ar-rays, points, regions, array views, parameter intents, array and object privatization, pure methods, absence of exceptions, and gather/reduce computations. In many cases, these extensions are also motivated by best practices in software engineering, and can also contribute to per-formance improvements in sequential code. A detailed case study of the Java Grande Forum benchmark suite illustrates the obstacles to compiler parallelization in current object-oriented languages, and shows that the extensions proposed in this paper can be effective in enabling compiler parallelization. The results in this paper motivate future work on build-ing an automatically parallelizing compiler for the language extensions proposed in this paper.