LLM4LLM: Bridging Kernel Benchmarks and Real Deployment via Closed-Loop Agentic Optimization

Hui Zeng, Pengfei Yang, Yanxin Chen, Fusong Ju, Xinran Wei


Abstract
Large language models have become increasingly capable agents for low-level code and kernel optimization, but isolated kernel benchmarks provide only a proxy for the deployment behavior that matters in language-model inference. We identify a benchmark-to-deployment gap: candidate kernels that appear correct and fast in standalone harnesses can exhibit different performance, safety, or phase behavior after integration into a real inference workload. We introduce LLM4LLM, a deployment-aware closed-loop optimization framework that starts from a target inference script, extracts phase-aware optimization tasks, searches with an experience-guided episodic agent, and accepts patches through in-model validation. Across ten language-model inference workloads on A100 and H100 GPUs, LLM4LLM improves end-to-end latency for every evaluated model, achieving 3.91x/6.98x geometric-mean speedups on A100/H100; as supporting kernel-level evidence, it also attains up to 2.745× GeoMean speedup on KernelBench Level 2.
Anthology ID:
2026.emnlp-main.859
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
19891–19902
Language:
URL:
https://aclanthology.org/2026.emnlp-main.859/
DOI:
Bibkey:
Cite (ACL):
Hui Zeng, Pengfei Yang, Yanxin Chen, Fusong Ju, and Xinran Wei. 2026. LLM4LLM: Bridging Kernel Benchmarks and Real Deployment via Closed-Loop Agentic Optimization. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 19891–19902, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
LLM4LLM: Bridging Kernel Benchmarks and Real Deployment via Closed-Loop Agentic Optimization (Zeng et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.859.pdf