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Deriving the Worst-Case Execution Time Input Values




The paper is an extended version of the conference paper.

Research group:

Publication Type:

Conference/Workshop Paper


21st Euromicro Conference of Real-Time Systems, (ECRTS09)


A Worst-Case Execution Time (WCET) analysis derives upper bounds for execution times of programs. Such bounds are crucial when designing and verifying real-time systems. A major problem with today's WCET analysis approaches is that there is no feedback on the particular values of the input variables that cause the program's WCET. However, this is important information for the real-time system developer.We present a novel approach to overcome this problem. In particular, we present a method, based on a combination of input-sensitive static WCET analysis and systematic search over the value space of the input variables, to derive the input value combination that causes the WCET. We also present several different approaches to speed up the search. Our evaluations show that the WCET input values can be relatively quickly derived for many type of programs, even for program with large input value spaces. We also show that the WCET estimates derived using the WCET input values often are much tighter than the WCET estimates derived when all possible input value combinations are taken into account.


author = {Andreas Ermedahl and Johan Fredriksson and Jan Gustafsson and Peter Altenbernd},
title = {Deriving the Worst-Case Execution Time Input Values},
note = {The paper is an extended version of the conference paper.},
pages = {45--54},
month = {July},
year = {2009},
booktitle = {21st Euromicro Conference of Real-Time Systems, (ECRTS09)},
url = {}