Curing schizophrenia by program rewriting in Esterel

Abstract

Synchronous languages such as Esterel can execute a series of statements in a single "instant" of time. If this series spans a loop iteration then it is possible that a computation local to the loop will have several distinct results during that "instant", which is referred to as schizophrenia. This makes the compilation of synchronous languages into more traditional computation models (such as C code or sequential logic) difficult. In a previous work (2004), we suggested to deal with schizophrenia through preprocessing in the Esterel language extended with a non-instantaneous jump statement. We now advocate for and experimented with such a program transformation, establishing the correctness, the completeness and the efficiency of our approach.