arXiv Machine Learning

Twig: Parallel and Memory-Efficient Tree Speculative Decoding for Hybrid-Attention LLMs

arXiv Machine Learning
Aug 4

Bole: Efficient Tree Speculation for Hybrid-Attention Language Models

arXiv:2608. 01651v1 Announce Type: cross Abstract: Hybrid-attention large language models combine full attention with recurrent linear attention to reduce long-context inference costs, yet their autoregressive decoding remains memory-bound.

By Li Wang, Yi Su, Xiabao Wu, Chiran You, Yongchao Liu, Zhan Qiu, Juelu Zhang, Jiajun Zheng, Fangxin Liu, Jie Zhang, Chen Tian, Chengying Huan
arXiv Machine Learning
Oct 28

Bastion: Budget-Aware Speculative Decoding with Tree-structured Block Diffusion Drafting

Bastion is a budget‑aware speculative decoding framework that uses tree‑structured block diffusion drafting to improve the efficiency of language model inference. It dynamically builds query‑dependent trees, balancing draft quality with hardware constraints, and incorporates an acceptance surrogate, an online latency estimator, and an adaptive best‑first expansion to maximize speed without sacrificing model distribution. The method achieves up to a 6.61× speedup over standard autoregressive decoding and outperforms state‑of‑the‑art block‑diffusion baselines by 39% across various benchmarks and GPU architectures.

By Soowon Oh, Nam Cao, Yujin Kim, Hojung Jung, Huzama Ahmad, Sangmin Bae, Se-Young Yun
arXiv Computation and Language
Aug 31

Speculative Probing: LLM Monitoring at Speculative-Decoding Cost

The paper introduces Speculative Probing, a method that repurposes the speculative‑decoding module of large language models for real‑time classification tasks. By appending a trained soft prompt to the target sequence, the approach leverages the already‑cached KV store during inference, adding negligible overhead while achieving higher accuracy than traditional hidden‑state probes. Experiments on four classification tasks across multiple models show that these lightweight probes outperform zero‑shot GPT‑5.4‑mini and rival or surpass specialized 8B safety classifiers without running a full LLM.

By Collin Zhang, Tingwei Zhang, Vitaly Shmatikov
arXiv AI
Jul 7

DSpark: Confidence-Scheduled Speculative Decoding with Semi-Autoregressive Generation

arXiv:2607. 05147v1 Announce Type: new Abstract: Speculative decoding accelerates Large Language Model (LLM) inference by decoupling draft generation from target verification.

By Xin Cheng, Xingkai Yu, Chenze Shao, Jiashi Li, Yunfan Xiong, Yi Qian, Jiaqi Zhu, Shirong Ma, Xiaokang Zhang, Jiasheng Ye, Qinyu Chen, Chengqi Deng, Jiping Yu, Damai Dai, Zhengyan Zhang, Yixuan Wei, Yixuan Tan, Wenkai Yang, Runxin Xu, Yu Wu, Zhean Xu, Xuanyu Wang, Muyang Chen, Rui Tian, Xiao Bi, Zhewen Hao, Shaoyuan Chen, Huanqi Cao, Wentao Zhang, Anyi Xu, Huishuai Zhang, Dongyan Zhao, Wenfeng Liang
arXiv Computation and Language
Sep 4

Margins, Not Windows: Training-Free Per-Step Lossy Speculative Decoding

The paper introduces AdaptiveSpec, a training‑free speculative decoding method that simultaneously adapts the per‑step verification rule and the draft‑tree shape using signals generated during decoding. It replaces the fixed token‑match rule with a margin‑based threshold and adjusts tree depth, width, and node count based on draft confidence and recent acceptance history, allowing the total draft count to vary. Experiments on SGLang show up to 56% throughput gains over EAGLE‑3 while maintaining 93% of lossless task accuracy on GSM8K, MATH‑500, and HumanEval across three models.

By Oszk\'ar Urb\'an, Young D. Kwon, Stylianos I. Venieris, Cecilia Mascolo
arXiv AI
1d ago

KVBuffer: IO-aware Serving for Linear Attention

KVBuffer is an IO‑aware serving mechanism designed to improve the efficiency of linear attention models. By buffering recent keys and values, it enables chunkwise decoding, parallel speculative decoding, and direct attention computation for short contexts, thereby reducing memory access and latency. Implemented in SGLang for Qwen3.5 and Nemotron‑3, KVBuffer achieves up to 1.47× faster batch decoding and a five‑fold increase in speculative decoding throughput when verifying four draft tokens.

By Longwei Zou, Lin Zhong