We propose a parallel specialized language that ensures portable and cost-predictable implementations on parallel computers. The language is basically a first-order, recursion-less, strict functional language equipped with a collection of higher-order functions or skeletons. These skeletons apply on (nested) vectors and can be grouped in four classes: computation, reorganization, communication, and mask skeletons. The compilation process is described as a series of transformations and analyses leading to spmd-like functional programs which can be directly translated into real parallel code. The language restrictions enforce a programming discipline whose benefit is to allow a static, symbolic, and accurate cost analysis. The parallel cost takes into account both load balancing and communications, and can be statically evaluated even when the actual size of vectors or the number of processors are unknown. It is used to automatically select the best data distribution among a set of standard distributions. Interestingly, this work can be seen as a cross fertilization between techniques developed within the Fortran parallelization, skeleton, and functional programming communities.

This paper considers parallel program development based on functional mutually recursive specifications. The development yields a communication structure linking an arbitrary fixed number of processors and an SPMD program executable on the structure. There are two steps in the development process: first, a parallel functional implementation is obtained through formal transformations in the Bird-Meertens formalism; it is then systematically transformed into an imperative target program with message passing. The approach is illustrated with a divide-and-conquer algorithm for numerical twodimensional sparse grid integration. The optimization of the target program and the results of experimental performance measurements on a 64-transputer network under OS Parix are presented. 1 Introduction We take the following approach to parallelization: we try to identify certain standard patterns of high-level functional specifications and to associate equivalent parallel programs to them...

We present a skeleton-based language which leads to portable and cost-predictable implementations on MIMD computers. The compilation process is described as a series of program transformations. We focus in this paper on the step concerning the distribution choice. The problem of automatic mapping of input vectors onto processors is addressed using symbolic cost evaluation. Source language restrictions are crucial since they permit to use powerful techniques on polytope volume computations to evaluate costs precisely. The approach can be seen as a cross-fertilization between techniques developed within the FORTRAN parallelization and skeleton communities.