Revolutionizing Mixed Precision Quantization: Towards Training-free Automatic Proxy Discovery via Large Language Models
Haidong Kang, Jun Du, Lihong Lin
TL;DR
This paper tackles the bottleneck of designing effective proxies for mixed-precision quantization (MPQ) by introducing TAP, an LLM-driven, training-free proxy discovery framework. TAP uses a three-component system (proxy candidate generator, fitness evaluator, and a Direct Policy Optimization loop) to automatically evolve high-quality MPQ proxies without human expertise or training. Across CNNs and Transformers, TAP achieves state-of-the-art accuracy with microsecond-scale search times and strong generalization to PTQ and larger architectures. The work demonstrates the viability of leveraging large language models for hardware-aware design tasks, offering a scalable path for MPQ across diverse models and datasets.
Abstract
Mixed-Precision Quantization (MPQ) liberates the Deep Neural Networks (DNNs) from the Out-Of-Memory (OOM) bottleneck, which garnered increasing research attention. However, conventional methods either searched from costly differentiable optimization, which is neither efficient nor flexible, or learned a quantized DNN from the proxy (i.e., HAWQ) manually designed by human experts, which is labor-intensive and requires huge expert knowledge. Can we design a proxy without involving any human experts and training? In this paper, we provide an affirmative answer by proposing a novel Large Language Models (LLMs)-driven Training-free Automatic Proxy (dubbed TAP) discovery framework, which reforms the design paradigm of MPQ by utilizing LLMs to find superior TAP tailored for MPQ, automatically. In addition, to bridge the gap between black-box LLMs and the tough MPQ task, we ingeniously propose simple Direct Policy Optimization (DPO) based reinforcement learning to enhance LLMs' reasoning by optimizing prompts, which can construct a positive feedback loop between the LLM and the MPQ task, enabling LLMs to generate better TAP in the next evolution. Extensive experiments on mainstream benchmarks demonstrate that TAP achieves state-of-the-art performance. Finally, we truly believe that our TAP will significantly contribute to the MPQ community by providing a new perspective on LLM-driven design algorithms.
