AutoVecCoder: Teaching LLMs to Generate Explicitly Vectorized Code

ShangZhan Li, Xinyu Yin, Xuanyu Jin, Ye He, Yuxin Zhou, Yuxuan Li, Xu Han, Wanxiang Che, Qi Shi, Ting Liu, Maosong Sun


Abstract
Vectorization via Single Instruction, Multiple Data (SIMD) architectures is a cornerstone of high-performance computing. To fully exploit hardware potential, developers often resort to explicit vectorization using intrinsics, as compiler-based auto-vectorization frequently yields suboptimal results due to conservative static analysis. While Large Language Models (LLMs) have demonstrated remarkable proficiency in general code generation, they struggle with explicit vectorization due to the scarcity of high-quality corpora and the strict semantic constraints of low-level hardware instructions. In this paper, we propose AutoVecCoder, a novel framework designed to empower LLMs with the capability of automated explicit vectorization. AutoVecCoder integrates two core components: VecPrompt, an automated data synthesis pipeline to inject domain-specific intrinsic knowledge; and VecRL, a reinforcement learning framework that aligns code generation with execution efficiency. AutoVecCoder-8B trained by this framework achieves state-of-the-art performance on the SSE and AVX subsets of SimdBench and, in some cases, generates implementations surpassing standard optimizations, effectively overcoming the inherent bottlenecks of traditional automated vectorization.
Anthology ID:
2026.findings-acl.1598
Volume:
Findings of the Association for Computational Linguistics: ACL 2026
Month:
July
Year:
2026
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San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
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Findings
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Publisher:
Association for Computational Linguistics
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Pages:
31942–31959
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https://preview.aclanthology.org/ingest-acl/2026.findings-acl.1598/
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Cite (ACL):
ShangZhan Li, Xinyu Yin, Xuanyu Jin, Ye He, Yuxin Zhou, Yuxuan Li, Xu Han, Wanxiang Che, Qi Shi, Ting Liu, and Maosong Sun. 2026. AutoVecCoder: Teaching LLMs to Generate Explicitly Vectorized Code. In Findings of the Association for Computational Linguistics: ACL 2026, pages 31942–31959, San Diego, California, United States. Association for Computational Linguistics.
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AutoVecCoder: Teaching LLMs to Generate Explicitly Vectorized Code (Li et al., Findings 2026)
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https://preview.aclanthology.org/ingest-acl/2026.findings-acl.1598.pdf
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