A Worst Case Timing Analysis Technique for Optimized Programs

We propose a technique to analyze the worst case execution times (WCETs) of optimized programs. Our work is based on a hierarchical timing analysis technique called the extended timing schema (ETS). A major hurdle in applying the ETS to optimized programs is the lack of correspondences in the control structure between the optimized machine code to be analyzed and the original source program written in a high-level programming language. We suggest a compiler-assisted approach where a timing analyzer relies on an optimizing compiler for a consistent hierarchical representation and an accurate source-level correspondence that are essential for accurate WCET analysis for optimized programs. In order to validate the proposed approach, we implemented a proof-of-concept version of a timing analyzer for a 256-bit VLIW processor and compared the analysis results with the simulation results. The experimental results show that the proposed solution can accurately predict the WCETs of highly-optimized VLIW programs.