  We provide open, transparent implementation and assessment of Google Brain's
deep reinforcement learning approach to macro placement and its Circuit
Training (CT) implementation in GitHub. We implement in open source key
"blackbox" elements of CT, and clarify discrepancies between CT and Nature
paper. New testcases on open enablements are developed and released. We assess
CT alongside multiple alternative macro placers, with all evaluation flows and
related scripts public in GitHub. Our experiments also encompass academic
mixed-size placement benchmarks, as well as ablation and stability studies. We
comment on the impact of Nature and CT, as well as directions for future
research.
