Removing Cycles in Esterel Programs

Abstract. Synchronous programs may contain cyclic signal interdependencies. This prohibits a static scheduling, which limits the choice of available compilation techniques for such programs. This paper proposes an algorithm which, given a constructive synchronous program, performs a semantics-preserving source-level code transformation that removes cyclic signal dependencies, and also exposes opportunities for further optimization. The transformation exploits the monotonicity of constructive programs, and is illustrated in the context of Esterel; however, it should be applicable to other synchronous languages as well. Experimental results indicate the efficacy of this approach, resulting in reduced run times and/or smaller code sizes, and potentially reduced compilation times as well. Furthermore, experiments with generating hardware indicate that here as well the synthesis results can be improved. Keywords. Synchronous Languages, Compilation, Cyclic Circuits, Constructiveness, Esterel...

• Type: Conference
• Year: 2004
• Where: DAGSTUHL
• Authors: Jan Lukoschus, Reinhard von Hanxleden
• Keywords: Cyclic Signal, DAGSTUHL 2004, DAGSTUHL 2007, Synchronous Languages, Synchronous Program