Tighten the computation of worst-case execution-time by detecting feasible paths

Abstract

The time to compute the Worst-Case Execution-Time (WCET) of a real-time program depends greatly on the technique used to generate paths. A method that is not able to distinguish between executable- and dead-paths could result in overestimation of the WCET. This paper addresses the issues of determining automatically the feasible paths. The algorithm targets the assembly code representation of a super-scalar processor program so that its hardware features can be accounted for during WCET estimation. The method attempts to identify constant values in a real-time program to reduce the amount of user provided information using the concept of partially-known variables.