Tree-Based WCET Analysis on Instrumentation Point Graphs

This paper presents a framework for combining low-level measurement data through high-level static analysis techniques on instrumented programs in order to generate WCET estimates, for which we introduce the instrumentation point graph (IPG). We present the notion of iteration edges, which are the most important property of the IPG from a timing analysis perspective since they allow more path-based information to be integrated into tree-based calculations on loops. The main focus of this paper, however, is an algorithm that performs a hierarchical decomposition of an IPG into an Itree to permit tree-based WCET calculations. The Itree representation supports a novel high-level structure, the meta-loop, which enables iteration edges to be merged in the calculation stage. The timing schema required for the Itree is also presented. Finally, we outline some conclusions and future areas of interest.