2004 Articles

Generating Fast Code from Concurrent Program Dependence Graphs

Zeng, Jia; Soviani, Cristian; Edwards, Stephen A.

While concurrency in embedded systems is most often supplied by real-time operating systems, this approach can be unpredictable and difficult to debug. Synchronous concurrency, in which a system marches in lockstep to a global clock, is conceptually easier and potentially more efficient because it can be statically scheduled beforehand. We present an algorithm for generating efficient sequential code from such synchronous concurrent specifications. Starting from a concurrent program dependence graph generated from the synchronous, concurrent language Esterel, we generate efficient, statically scheduled sequential code while adding a minimal amount of runtime scheduling overhead. Experimentally, we obtain speedups as high as six times over existing techniques. While we applied our technique to Esterel, it should be applicable to other synchronous, concurrent languages.