Compilation to parallel programs from constraints

This paper describes the first results from research on the compilation of constraint systems into task level parallel programs in a procedural language. This is the only research of which we are aware which attempts to generate efficient parallel programs for numerical computation from constraint systems. Computations are expressed as constraint systems. A dependence graph is derived from the constraint system and a set of input variables. The dependence graph, which exploits the parallelism in the constraints, is mapped to the language CODE, which represents parallel computation structures as generalized dependence graphs. Finally, parallel C programs are generated. To extract parallel programs of appropriate granularity, the following features are included. (i) modularity, (ii) operations over structured types as primitives, (iii) sequential C functions. A prototype of the compiler has been implemented. The domain of matrix computations is targeted for applications. Initial results are very encouraging