titleDomino: Decoupling Causal Modeling from Autoregressive Drafting in Speculative Decoding
authorsJianuo Huang, Yaojie Zhang, Qituan Zhang, Hao Lin, Hanlin Xu, Linfeng Zhang
date2026-05-28
venuearXiv (preprint, not peer reviewed)
idarXiv:2605.29707
affiliationShanghai Jiao Tong University
upvotes62 (Hugging Face Daily Papers, 2026-11-01)
linksabs pdf hf code
abstractSpeculative decoding accelerates LLM inference by drafting multiple tokens and verifying them in parallel with the target model. However, its practical speedup is constrained by the trade-off between draft quality and drafting cost: autoregressive drafters model causal dependencies among draft tokens but incur sequential overhead, while parallel drafters reduce drafting cost but weaken intra-block dependency modeling. In this paper, we propose Domino, a speculative decoding framework that decouples causal dependency modeling from expensive autoregressive draft execution. Domino first uses a parallel draft backbone to produce preliminary draft distributions for the entire block, and then applies a lightweight Domino head to refine them with prefix-dependent causal information. To stabilize teacher-forced causal encoding, we further introduce a base-anchored training curriculum that first strengthens the parallel backbone and then gradually shifts optimization toward the causally corrected final distribution. Experiments on Qwen3 models show that Domino achieves up to \(5.49\times\) end-to-end speedup under the Transformers backend and up to \(5.8\times\) throughput speedup under SGLang serving.

cite

@misc{huang2026domino,
  title={Domino: Decoupling Causal Modeling from Autoregressive Drafting in Speculative Decoding},
  author={Jianuo Huang and Yaojie Zhang and Qituan Zhang and Hao Lin and Hanlin Xu and Linfeng Zhang},
  year={2026},
  eprint={2605.29707},
  archivePrefix={arXiv},
  url={https://arxiv.org/abs/2605.29707}
}