arXiv AI
Jun 2

SimSD: Simple Speculative Decoding in Diffusion Language Models

arXiv:2606. 02544v1 Announce Type: cross Abstract: Diffusion large language models (dLLMs) have recently emerged as a promising alternative to autoregressive (AR) LLMs, offering faster inference through parallel or blockwise decoding.

By Junxia Cui, Haotian Ye, Runchu Tian, Hongcan Guo, Jinya Jiang, Haoru Li, Chaojie Ren, Yiming Huang, Kaijie Zhu, Zhongkai Yu, Kun Zhou, Jingbo Shang
arXiv Computation and Language
Aug 31

Trajectory-Level Speculative Decoding for Diffusion Language Models

The paper introduces a trajectory-level speculative decoding framework for diffusion-based language models (dLLMs), addressing the limitation of existing strategies that revert to single-token generation when confidence is low. By constructing draft denoising trajectories through confidence-stratified tree exploration and verifying them with blockwise parallel evaluation and bidirectional attention masking, the method also incorporates inter-block speculation to exploit the models’ bidirectional structure. Experiments show a 30–40% reduction in denoising iterations, a token-per-step increase from 2.6 to 4.3, and a 7–14× speedup over vanilla dLLMs while maintaining accuracy within 1% on reasoning and code benchmarks.

By Tianxiang Pan, Baitao Gong, Mo Guang, Hongwei Yong, Tianpeng Jiang, Yaqian Li, Zheng Cao, Kaiwen Long
arXiv Machine Learning
4d ago

On-Policy Residual Learning for Diffusion Language Models

On-Policy Residual Learning for Diffusion Language Models (ORL) introduces a framework that learns residual context directly from model-generated trajectories, using an entropy-contraction objective to sharpen predictions. The approach co-designs algorithmic and system components—such as asynchronous residual capture, block-diffusion attention, and packed compute-balanced training—to enable practical scaling. Experiments on a 4B DLM converted from Qwen3-4B show up to 6.2× faster tokens per forward and 6.9× higher end-to-end throughput, while also improving speed-quality trade-offs over autoregressive models and transferring effectively to other DLMs like LLaDA-2.1-mini and DiffusionGemma.

By Yifan Yu, Yuqing Jian, Jisen Li, Yuezhou Hu, Tianyi Zhang, Xiaoxia Wu, Rui-Jie Zhu, Junxiong Wang, Zhongzhu Zhou, Fan Lai, James Zou, Chenfeng Xu