Beyond Lemma Sharing -- Novel Parallelization Strategies for Property Directed Reachability
Property Directed Reachability (PDR) is a commonly used technique for automated hardware model checking, yet efficiently parallelizing it remains a significant challenge. Existing approaches, such as lemma sharing, often suffer from limited scalability as processor counts increase. In this work, we present two novel sharing-based parallelization strategies, preemptive propagation and ARPOS, and compare their performance with classical lemma sharing. To this end, we develop an asynchronous MPI-based message passing framework for the state-of-the-art rIC3 hardware model checker. Experimental results on the 2025 Hardware Model Checking competition benchmark demonstrate that our preemptive propagation strategy yields a significant performance boost over classical lemma sharing.