GPU Accelerated Strong and Branching Bisimilarity Checking

Bisimilarity checking is an important operation to perform explicit-state model checking when the state space of a model under verification has already been generated. It can be applied in various ways: reduction of a state space w.r.t. a particular flavour of bisimilarity, or checking that two given state spaces are bisimilar. Bisimilarity checking is a computationally intensive task, and over the years, several algorithms have been presented, both sequential, i.e. single-threaded, and parallel, the latter either relying on shared memory or message-passing. In this work, we first present a novel way to check strong bisimilarity on general-purpose graphics processing units (GPUs), and show experimentally that an implementation of it for CUDA-enabled GPUs is competitive with other parallel techniques that run either on a GPU or use message-passing on a multi-core system. Building on this, we propose, to the best of our knowledge, the first many-core branching bisimilarity checking algorithm, an implementation of which shows speedups comparable to our strong bisimilarity checking approach.