Influence of procedure cloning on WCET prediction

For the worst-case execution time (WCET) analysis, especially loops are an inherent source of unpredictability and loss of precision. This is caused by the difficulty to obtain safe and tight information on the number of iterations executed by a loop in the worst case. In particular, datadependent loops whose iteration counts depend on function parameters are extremely difficult to analyze precisely. Procedure cloning helps by making such data-dependent loops explicit within the source code, thus making them accessible for high-precision WCET analyses. This paper presents the effect of procedure cloning applied at the source-code level on worst-case execution time. The optimization generates specialized versions of functions being called with constant values as arguments. In standard literature, it is used to enable further optimizations like constant propagation within functions and to reduce calling overhead. We show that procedure cloning for WCET minimization leads to significant ...

• Type: Conference
• Year: 2007
• Where: CODES
• Authors: Paul Lokuciejewski, Heiko Falk, Martin Schwarzer, Peter Marwedel, Henrik Theiling
• Keywords: CODES 2007, Procedure Cloning, Software Engineering, WCET Minimization, Worst-case Execution Time