Evaluation of Automatic Flow Analysis for WCET Calculation on Industrial Real-Time System Code

A static worst-case execution time (WCET) analysis derives upper bounds for the execution times of programs. Such analysis requires information about the possible program flows. The current practice is to provide this information manually, which can be laborious and error-prone. An alternative is to derive this information through an automated flows analysis.In this article, we present a case study where an automatic flows analysis method was tested on industrial real-time system code. The same code was the subject of an earlier WCET case study, where it was analysed using manual annotations for the flows information. The purpose of the current study was to see to which extent the same flows information could be found automatically. The results show that for the most part this is indeed possible, and we could derive comparable WCET estimates using the automatically generated flow information. In addition, valuable insights were gained on what is needed to make flow analysis methods work on real production code.