DART: Low-Latency Parallel Drafting with Continuity-Aware Tree Pruning for Speculative Decoding

Fuliang Liu, Xue Li, Ketai Zhao, Yinxi Gao, Ziyan Zhou, Zhonghui Zhang, Wanchun Dou, Sheng Zhong, Zhibin Wang, Chen Tian


Abstract
Speculative decoding is an effective and lossless approach for accelerating LLM inference. However, existing widely adopted model-based draft designs, such as EAGLE3, improve accuracy at the cost of multi-step autoregressive inference, resulting in high drafting latency and ultimately rendering the drafting stage itself a performance bottleneck. We propose DART, a low-latency parallel drafting framework for speculative decoding. DART predicts logits for multiple future masked positions in parallel within a single forward pass based on hidden states of the target model, thereby eliminating autoregressive rollouts in the draft model while preserving a lightweight design. Based on these parallel logit predictions, we further introduce an efficient tree pruning algorithm that constructs high-quality draft token trees with N-gram-enforced semantic continuity. DART substantially reduces draft-stage overhead while preserving high draft accuracy, leading to significantly improved end-to-end decoding speed. Experimental results demonstrate that DART achieves a 2.03×–3.44× wall-clock time speedup across multiple datasets, surpassing EAGLE3 by 30% on average and offering a practical speculative decoding framework.
Anthology ID:
2026.emnlp-main.492
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
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Pages:
11316–11331
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URL:
https://aclanthology.org/2026.emnlp-main.492/
DOI:
Bibkey:
Cite (ACL):
Fuliang Liu, Xue Li, Ketai Zhao, Yinxi Gao, Ziyan Zhou, Zhonghui Zhang, Wanchun Dou, Sheng Zhong, Zhibin Wang, and Chen Tian. 2026. DART: Low-Latency Parallel Drafting with Continuity-Aware Tree Pruning for Speculative Decoding. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 11316–11331, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
DART: Low-Latency Parallel Drafting with Continuity-Aware Tree Pruning for Speculative Decoding (Liu et al., EMNLP 2026)
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https://aclanthology.org/2026.emnlp-main.492.pdf