Large Language Models for Energy-Efficient Code: Emerging Results and Future Directions
Huiyun Peng, Arjun Gupte, Nicholas John Eliopoulos, Chien Chou Ho, Rishi Mantri, Leo Deng, Wenxin Jiang, Yung-Hsiang Lu, Konstantin Läufer, George K. Thiruvathukal, James C. Davis
TL;DR
The paper investigates using large language models to optimize energy consumption in software by refactoring code while preserving semantics. It introduces an automated, energy-aware refactoring pipeline with Energy-Aware Prompting (EAP) and Energy Optimization Evaluation (EOE) and evaluates it using the Energy-Language benchmark, reporting energy reductions in several programs and highlighting improvements in memory traffic and vectorization. Key contributions include a practical prototype combining generator and evaluator LLMs and a discussion of challenges such as energy-variance and run-time errors, along with a concrete research agenda. The work demonstrates a promising direction for integrating energy considerations into software engineering practice and lays out steps for broader validation and refinement. Overall, it provides a foundation for energy-focused optimization using LLMs and emphasizes a need for multi-objective and hardware-aware approaches.
Abstract
Energy-efficient software helps improve mobile device experiences and reduce the carbon footprint of data centers. However, energy goals are often de-prioritized in order to meet other requirements. We take inspiration from recent work exploring the use of large language models (LLMs) for different software engineering activities. We propose a novel application of LLMs: as code optimizers for energy efficiency. We describe and evaluate a prototype, finding that over 6 small programs our system can improve energy efficiency in 3 of them, up to 2x better than compiler optimizations alone. From our experience, we identify some of the challenges of energy-efficient LLM code optimization and propose a research agenda.
