A Fast Learning-Driven Signoff Power Optimization Framework.

Modern high-performance System-on-Chip (SoC) design flows highly depend on signoff tools to perform timing-constrained power optimization through Engineering Change Orders (ECOs), which involve gate-sizing and $V_{th}$ -assignment of standard cells. However, ECOs are highly time-consuming, and the power improvement is unknown in advance. Ever since the industrial benchmarks released by the ISPD-2012 gate-sizing contest, active research has been conducted extensively. Nonetheless, previous works were mostly based on heuristics or analytical methods whose timing models were oversimplified and lacked formal validations from commercial signoff tools. In this paper, we propose ECO-GNN, a transferable graph-learning-based framework, which harnesses graph neural networks (GNNs) to perform commercial-quality signoff power optimization through discrete $V_{th}$ -assignment. Our framework generates tool-accurate optimization results instantly on unseen netlists that are not utilized in the training process. Furthermore, we implement a GNN-based explanation method to interpret the optimization results achieved by our framework. Experimental results on 14 industrial designs, including a RISC-V-based multi-core system and the renowned ISPD-2012 benchmarks, demonstrate that our framework achieves up to 14X runtime improvement with similar signoff power optimization quality compared with Synopsys PrimeTime.