Celling SHIM: Compiling Deterministic Concurrency to a Heterogeneous Multicore

Parallel architectures are the way of the future, but are notoriously difficult to program. In addition to the low-level constructs they often present (e.g., locks, DMA, and non-sequential memory models), most parallel programming environments admit data races: the environment may make nondeterministic scheduling choices that can change the function of the program. We believe the solution is model-based design, where the programmer is presented with a constrained higher-level language that prevents certain unwanted behavior. In this paper, we describe a compiler for the SHIM scheduling-independent concurrent language that generates code for the Cell Broadband heterogeneous multicore processor. The complexity of the code our compiler generates relative to the source illustrates how difficult it is to manually write code for the Cell. We demonstrate the efficacy of our compiler on two examples. While the SHIM language is (by design) not ideal for every algorithm, it works well for certain applications and simplifies the parallel programming process, especially on the Cell architecture