The W-SEPT Project: Towards Semantic-Aware WCET Estimation.

Critical embedded systems are generally composed of repetitive tasks that must meet hard timing constraints, such as termination deadlines. Providing an upper bound of the worst-case execution time (WCET) of such tasks at design time is necessary to guarantee the correctness of the system. In static WCET analysis, a main source of over-approximation comes from the complexity of the modern hardware platforms: their timing behavior tends to become more unpredictable because of features like caches, pipeline, branch prediction, etc. Another source of over-approximation comes from the software itself: WCET analysis may consider potential worst-cases executions that are actually infeasible, because of the semantics of the program or because they correspond to unrealistic inputs. The W-SEPT project, for WCET, Semantics, Precision and Traceability, has been carried out to study and exploit the influence of program semantics on the WCET estimation. This paper presents the results of this project : a semantic-aware WCET estimation workflow for high-level designed systems.