A Framework to Quantify the Overestimations of Static WCET Analysis

Hugues Cassé (1, 2) , Haluk Ozaktas (1) , Christine Rochange (1)

1 IRIT-TRACES - Groupe de Recherche en Architecture et Compilation pour les systèmes embarqués
2 UT3 - Université Toulouse III - Paul Sabatier

To reduce complexity while computing an upper bound on the worst-case execution time, static WCET analysis performs over-approximations. This feeds the general feeling that static WCET estimations can be far above the real WCET. This feeling is strengthened when these estimations are compared to measured execution times: generally, it is very unlikely to capture the worstcase from observations, then the difference between the highest watermark and the proven WCET upper bound might be considerable. In this paper, we introduce a framework to quantify the possible overestimation on WCET upper bounds obtained by static analysis. The objective is to derive a lower bound on the WCET to complement the upper bound.

Mots clés: Overestimation; Uncertainty; Static WCET analysis; Cache analysis

Domaines: Réseaux et télécommunications [cs.NI]; Système d'exploitation [cs.OS]; Architectures Matérielles [cs.AR]; Systèmes embarqués

Hugues Cassé, Haluk Ozaktas, Christine Rochange. A Framework to Quantify the Overestimations of Static WCET Analysis. 15th International Workshop on Worst-Case Execution Time Analysis (WCET 2015), Jul 2015, Lund, Sweden. pp. 1-10. ⟨hal-01371787⟩