PIChecker: A POR and Interpolation based Verifier for Concurrent Programs (Competition Contribution).

Abstract is a tool for verifying reachability properties of concurrent C programs. It moderates the trace-space explosion problem, aggravated by thread alternation, through utilizing the PC-DPOR and C-Intp techniques. The PC-DPOR technique constructs a constrained dependency graph to refine dependencies between transitions. With this basis, the inherent imprecision of the dependence over-approximation can be overcome. Thereby, many redundant equivalent traces are prevented from being explored. On the other hand, the C-Intp technique performs conditional interpolation to confine the reachable regions of states, so that infeasible conditional branches which occur more frequently in concurrent verification tasks could be pruned automatically. We have implemented the above techniques on top of the open-source program analysis framework .