ILP-Based Interprocedural Path Analysis

Program analysis usually works on control flow graphs (CFGs) and on a call graph (CG). The standard CGs contain one node for each function, but for precise analyses, it may be desirable to distinguish function invocations by their execution history. This distinction is useful, e.g., to improve the precision of worst-case execution time (WCET) analysis for real-time systems. Our WCET analysis supports these advanced techniques for interprocedural analysis. The first part of the WCET analysis, i.e, the prediction of microarchitecture behaviour, uses Abstract Interpretation, for which tools already support the methods for function distinction by execution history. The second part of WCET prediction is the worst-case path analysis, which can be performed using the well-established technique of Implicit Path Enumeration using Integer Linear Programming. So far, support for arbitrary interprocedural analysis techniques in one framework was not discussed in literature. This paper closes this gap.