The subject disclosure is directed towards using fingerprints, comprising lists of simulation results corresponding to partial (random sampled) simulation results, to determine whether a full simulation may be avoided by reusing simulation results from a previous full simulation. Before running a full simulation, a current fingerprint is obtained via a partial simulation. If a previous fingerprint matches (is identical or similar to) the current fingerprint, the associated previous results are reused. Also described is indexing fingerprint data to facilitate efficient lookup-based fingerprint matching.