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In the standard framework for worst-case execution time (WCET) analysis of programs, the main data structure is a single instance of integer linear programming (ILP) that represents the whole program. The instance of this NP-hard problem must be solved to find an estimate for WCET, and it must be refined if the estimate is not tight. We propose a new(More)
We present an automatic method for computing tight upper bounds on the iteration number of special classes of program loops. These upper bounds are further used in the WCET analysis of programs. To do so, we refine program flows using SMT reasoning and rewrite multi-path loops into single-path ones. Single-path loops are further translated into a set of(More)
We describe the structure and the usage of a new software tool, called r-TuBound, for deriving symbolic loop iteration bounds in the worst-case execution time (WCET) analysis of programs. r-TuBound implements algorithms for pattern-based recurrence solving and program flow refinement, and it was successfully tested on a wide range of examples. The purpose(More)
The Worst-Case Execution Time (WCET) computed by a WCET analyzer is usually not tight, leaving a gap between the actual and the computed WCET of a program. In this article we present a novel on-demand WCET feasibility refinement technique, called <i>WCET Squeezing</i>, for minimizing this gap. WCET Squeezing provides conceptually new means for addressing(More)
In order to ensure safety of critical real-time systems it is crucial to verify their temporal properties. Such a property is the Worst-Case Execution Time (WCET), which is obtained by architecture-dependent timing analysis and architecture-independent flow fact analysis. In this article we present a WCET annotation language which is able to express such(More)
SmacC is a symbolic execution engine for C programs. It can be used for program verification, bounded model checking and generating SMT benchmarks. More recently we also successfully applied SmacC for high-level timing analysis of programs to infer exact loop bounds and safe over-approximations. SmacC uses the logic for bit-vectors with arrays to construct(More)
We have recently shown that symbolic execution together with the implicit path enumeration technique can successfully be applied in the Worst-Case Execution Time (WCET) analysis of programs. Symbolic execution offers a precise framework for program analysis and tracks complex program properties by analyzing single program paths in isolation. This path-wise(More)
This text gives an overview about my current research in timing analysis at the Vienna University of Technology. After a short introduction to the topic follows the description of an approach relying on CLP, the implicit path enumeration technique (IPET). This technique is also used in a tool developed at the institute of Computer Languages (TuBound).(More)
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