Abstract not found

In the design of real-time and embedded systems, it is important to establish a bound on the worst-case execution time (WCET) of programs to assure via schedulability analysis that deadlines are not missed. Static WCET analysis is performed by a timing analysis tool. This paper describes novel improvements to such a tool, allowing parametric timing analysis to be performed. Parametric timing analyzers receive an upper bound on the number of loop iterations in terms of an expression which is used to create a parametric formula. This parametric formula is later evaluated to determine the WCET based on input values only known at runtime. Effecting a transformation from a numeric to a parametric timing analyzer requires two innovations: 1) a summation solver capable of summation non-constant expressions and 2) a polynomial data structure which can replace integers as the basis for all calculations. Both additions permit other methods of analysis (e.g. caching, pipeline, constraint) to occur simultaneously. Combining these techniques allows our tool to statically bound the WCET for a larger class of benchmarks.

The worst case execution times, the WCET, are often essential to know for tasks that have to fulfill deadlines. Such tasks can often be found in real time systems. In order to calculate the WCET, flow constraints, like maximum iterations of loops, needs to be known. Entering all such flow constraints to a WCET tool require a lot of work for the user to be done. Therefore methods for achieving flow constraints automatically are important. However, most of today 's WCET tools require manual annotations of loops for real sized programs. One of the reasons is that the most powerful analysis methods are too costly in terms of computation power. This paper