Dr. RTL: Autonomous Agentic RTL Optimization through Tool-Grounded Self-Improvement

TL;DR

Dr. RTL is an agentic framework that enables realistic, continual self-improvement in RTL optimization, significantly enhancing performance and area metrics on real-world designs using a multi-agent, skill-based approach.

Contribution

It introduces a realistic evaluation environment and a reusable skill library for RTL optimization, advancing beyond existing methods' limitations.

Findings

Achieves 21% WNS and 17% TNS improvements on average.

Reduces area by 6% compared to commercial tools.

Uses a multi-agent framework for critical-path analysis and RTL rewriting.

Abstract

Recent advances in large language models (LLMs) have sparked growing interest in automatic RTL optimization for better performance, power, and area (PPA). However, existing methods are still far from realistic RTL optimization. Their evaluation settings are often unrealistic: they are tested on manually degraded, small-scale RTL designs and rely on weak open-source tools. Their optimization methods are also limited, relying on coarse design-level feedback and simple pre-defined rewriting rules. To address these limitations, we present Dr. RTL, an agentic framework for RTL timing optimization in a realistic evaluation environment, with continual self-improvement through reusable optimization skills. We establish a realistic evaluation setting with more challenging RTL designs and an industrial EDA workflow. Within this setting, Dr. RTL performs closed-loop optimization through a multi-agent framework for critical-path analysis, parallel RTL rewriting, and tool-based evaluation. We further introduce group-relative skill learning, which compares parallel RTL rewrites and distills the optimization experience into an interpretable skill library. Currently, this library contains 47 pattern--strategy entries for cross-design reuse to improve PPA and accelerate convergence, and it can continue evolving over time. Evaluated on 20 real-world RTL designs, Dr. RTL achieves average WNS/TNS improvements of 21%/17% with a 6% area reduction over the industry-leading commercial synthesis tool.