Tomáš Vojnar

Milan Ceska, Jiri Matyas, Vojtech Mrazek et al.

We present a novel approach for designing complex approximate arithmetic circuits that trade correctness for power consumption and play important role in many energy-aware applications. Our approach integrates in a unique way formal methods providing formal guarantees on the approximation error into an evolutionary circuit optimisation algorithm. The key idea is to employ a novel adaptive search strategy that drives the evolution towards promptly verifiable approximate circuits. As demonstrated in an extensive experimental evaluation including several structurally different arithmetic circuits and target precisions, the search strategy provides superior scalability and versatility with respect to various approximation scenarios. Our approach significantly improves capabilities of the existing methods and paves a way towards an automated design process of provably-correct circuit approximations.

Michal Kotoun, Petr Peringer, Veronika Šoková et al.

This paper describes shortly the basic principles of the PredatorHP (Predator Hunting Party) shape analyzer and presents its recent improvements. One of the most visible changes is the way PredatorHP handles interval-sized memory regions, which is particularly useful for dealing with arrays whose size is not fixed in advance. Further, the paper characterizes PredatorHP's participation in SV-COMP 2019, pointing out its strengths and weakness and the way they were influenced by the latest changes in the tool.

Viktor Malik, Martin Hruska, Peter Schrammel et al.

2LS is a framework for analysis of sequential C programs that can verify and refute program assertions and termination. The 2LS framework is built upon the CPROVER infrastructure and implements template-based synthesis techniques, e.g. to find invariants and ranking functions, and incremental loop unwinding techniques to find counterexamples and k-induction proofs. The main improvements in this year's version are the ability of 2LS to analyse programs requiring combined reasoning about shape and content of dynamic data structures, and an instrumentation for memory safety properties.