Reevaluating Google's Reinforcement Learning for IC Macro Placement

A 2021 paper in Nature by Mirhoseini et al.30 about the use of reinforcement learning (RL) in the physical design of silicon chips raised eyebrows, drew critical media coverage, and stirred up controversy due to poorly documented claims. The paper, authored by Google researchers, withheld critical methodological steps, and most inputs needed to reproduce its results. Our meta-analysis shows how two separate evaluations filled in the gaps and demonstrated that Google RL lags behind human chip designers, a well-known algorithm (simulated annealing), and generally available commercial software, while also being slower. Crosschecked data indicates that the integrity of the Nature paper is substantially undermined, owing to errors in conduct, analysis, and reporting. Before publishing, Google rebuffed internal allegations of fraud which still stand.