Abstract. There are several algorithms for producing the canonical DFA from a given NFA. While the theoretical complexities of these algorithms are known, there has not been a systematic empirical comparison between them. In this work we propose a probabilistic framework for testing the performance of automatatheoretic algorithms. We conduct a direct experimental comparison between Hopcroft's and Brzozowski's algorithms. We show that while Hopcroft's algorithm has better overall performance, Brzozowski's algorithm performs better for "highdensity" NFA. We also consider the universality problem, which is traditionally solved explicitly via the subset construction. We propose an encoding that allows this problem to be solved symbolically via a model-checker. We compare the performance of this approach to that of the standard explicit algorithm, and show that the explicit approach performs significantly better.

Abstract-Monitoring temporal SystemC properties is crucial for the validation of functional and transaction-level models, yet the current SystemC standard provides no support for temporal specifications. In this work we describe a temporal monitoring framework for the SystemC specification language defined by Tabakov et al. at FMCAD'08. Our framework uses a very minimal modification of the SystemC kernel, exposing event notifications and simulation phases. The user code is instrumented to allow observation of the relevant parts of the model state. As proof of concept, we use the framework to specify and check properties of two SystemC models. We show that monitoring SystemC properties using this framework has reasonable overhead (0.01% -1%) and has decreasing marginal cost. Finally, we demonstrate that monitoring at different levels of abstraction requires very small changes to the specification and the generated monitors. Based on our empirical results we argue that the additional expressive powers and flexibility of the framework does not incur a serious performance hit.

We describe a general approach for defining new temporal specification languages, and adopting existing languages, for SystemC. We define the concept of "underlying trace" describing the execution of a SystemC model, and then define a set of important primitive assertions about the states in the trace. Our framework not only provides additional expressive power for making atomic assertions, but also provides very fine control over the temporal resolution of the language. Using the primitives defined here as clock expression allows sampling at different levels, from transaction-level to the level of individual statements. The advantage of our approach is that it defines important SystemC properties that have been overlooked previously, and also provides a uniform mechanism for specifying the sampling rate of temporal languages.

SystemC is a modeling language built as an extension of C++. Its growing popularity and the increasing complexity of designs have motivated research efforts aimed at the verification of SystemC models using assertionbased verification (ABV), where the designer asserts properties that capture the design intent in a formal language such as PSL or SVA. The model then can be verified against the properties using runtime or formal verification techniques. In this paper we focus on automated generation of runtime monitors from temporal properties. Our focus is on minimizing runtime overhead, rather than monitor size or monitor-generation time. We identify four issues in monitor generation: state minimization, alphabet representation, alphabet minimization, and monitor encoding. We conduct extensive experimentation and identify a combination of settings that offers the best performance in terms of runtime overhead.

SystemC is a modeling language built as an extension of C++. Its growing popularity and the increasing complexity of designs have motivated research efforts aimed at the verification of SystemC models using assertionbased verification (ABV), where the designer asserts properties that capture the design intent in a formal language such as PSL or SVA. The model then can be verified against the properties using runtime or formal verification techniques. In this paper we focus on automated generation of runtime monitors from temporal properties. Our focus is on minimizing runtime overhead, rather than monitor size or monitor-generation time. We identify four issues in monitor generation: state minimization, alphabet representation, alphabet minimization, and monitor encoding. We conduct extensive experimentation and identify a combination of settings that offers the best performance in terms of runtime overhead.