Context-sensitive Parametric WCET Analysis

Clément Ballabriga (1) , Julien Forget (1) , Giuseppe Lipari (1)

1 CRIStAL - Centre de Recherche en Informatique, Signal et Automatique de Lille - UMR 9189

In this paper, we propose a WCET analysis that focuses on two aspects. First, it supports context-sensitive hardware and software timing effects, meaning that it is sensitive to the execution history of the program and thus can account for effects like cache persistence, triangular loop, etc. Second, it supports the introduction of parameters in both the software model (e.g. parametric loop bounds) and the hardware model (e.g. number of cache misses). WCET computation by static analysis is traditionally handled by the Implicit Path Enumeration Technique (IPET), using an Integer Linear Program (ILP) that is difficult to resolve parametrically. We suggest an alternative tree-based approach. We define a context-sensitive CFG format to express these effects, and we provide an efficient method to process it, giving a parametric WCET formula. Experimental results show that this new method is significantly faster and more accurate than existing parametric approaches. 1998 ACM Subject Classification C.3 Real-time and embedded systems

Mots clés: WCET analysis; WCET estimation

Domaines: Systèmes embarqués; Système d'exploitation [cs.OS]

Clément Ballabriga, Julien Forget, Giuseppe Lipari. Context-sensitive Parametric WCET Analysis. 15th International Workshop on Worst-Case Execution Time Analysis, Dec 2015, Lund Sweden. ⟨10.4230/OASIcs.WCET.2015.55⟩. ⟨hal-01239158⟩