arXiv Machine Learning

DUEL: Exact Likelihood Reshapes Masked Diffusion Scaling Laws and Beyond

arXiv AI
Jul 28

UNIFUSION: Adapting Autoregressive Language Models into Discrete Diffusion under a Unified Reverse-Rate Objective

arXiv:2607. 24507v1 Announce Type: cross Abstract: Existing methods mainly adapt pretrained autoregressive (AR) language models to masked diffusion, whereas we directly adapt them to uniform-noise diffusion, where every token remains editable during sampling.

By Xiaoyi Jiang, Jingyuan Li, Yixuan Jiang, Wei Liu, Yi Zhu, Zuoqiang Shi, Pipi Hu
arXiv Machine Learning
Oct 8

CoDR: Training-Free Confidence-Drift Remasking for Diffusion Language Models

CoDR (Confidence Drift Remasking) is a training‑free, sampler‑agnostic refinement pass for masked diffusion language models that detects and corrects early token commitments that become unsupported as context grows denser. It estimates confidence drift for all committed positions using only a few forward passes and remasks only the tokens whose confidence has dropped, thereby improving accuracy across multiple backbones, tasks, and samplers with modest computational overhead.

By Yue Wu, Qinghe Zhang, Yu Zhang, Jian Huang
arXiv Machine Learning
Sep 25

Enabling Approximate Joint Sampling in Diffusion LMs

The paper introduces a lightweight single‑layer sampler that allows masked diffusion language models to approximate joint sampling of multiple tokens in a single full‑model forward pass. By training the sampler to mimic exact joint sampling from a frozen diffusion model, the authors enable parallel unmasking of tokens while maintaining a close match to the true joint distribution. Experiments on Dream‑7B and Llada‑7B models show that unmasking four tokens per denoising step yields a MAUVE score of 0.87, a substantial improvement over the marginal baseline of 0.31.

By Parikshit Bansal, Sujay Sanghavi
arXiv Machine Learning
Sep 11

Continuous Diffusion Scales Competitively with Discrete Diffusion for Language

The paper revisits the continuous diffusion language model Plaid and introduces RePlaid, aligning its architecture with modern discrete diffusion models. RePlaid achieves a compute gap of only 20× compared to autoregressive models, surpasses Duo with fewer parameters, and outperforms MDLM in over‑trained settings. On OpenWebText, RePlaid sets a new state‑of‑the‑art continuous diffusion perplexity of 22.1 and demonstrates superior generation quality, while theoretical analysis links likelihood‑based training to linear cross‑entropy over time and structured embedding geometries.

By Zhihan Yang, Wei Guo, Shuibai Zhang, Subham Sekhar Sahoo, Yongxin Chen, Arash Vahdat, Morteza Mardani, John Thickstun
arXiv Machine Learning
Oct 23

Random Remasking Scales Masked Diffusion Inference

The paper introduces Random Remask-Denoise (R$^2$D) inference, a test‑time, finetuning‑free method for masked diffusion models that randomly re‑introduces masks and denoises to form a Markov chain on clean sequences. It also proposes Trajectory Correction Training (TCT), which trains the denoiser by exposing it to its own errors during generation. Experiments show that R$^2$D with TCT achieves near‑log‑linear scaling, achieving over 97% accuracy on hard Sudoku puzzles, over 99% on 3‑SAT, and surpasses iterative correction baselines on language tasks such as HumanEval+.

By Zhaoyi Zhou, Frank Wu, Andrea Zanette
arXiv Machine Learning
Sep 4

Unlocking Lossless Speedups in LLMs via Discrete Diffusion

arXiv:2609. 04010v1 Announce Type: new Abstract: Large Language Models (LLMs) owe much of their success to next-token prediction (NTP), but their autoregressive (AR) structure requires slow, sequential token generation.

By Subham Sekhar Sahoo, Lingjie Chen, Khiem Pham, Jonathan Geuter, Chaitanya Dwivedi, Varad Pimpalkhute, Yash Akhauri, Alexander Moreno, Mikhail Yurochkin, Zhenting Wang, Mostafa Elhoushi, Nolan Dey, Shane Bergsma, Joel Hestness, John Thickstun, Eric Xing, Zhengzhong Liu
arXiv Machine Learning
Oct 16

Query-Efficient Rejection Sampling for Parallel Masked Diffusion

The paper introduces the Single-Increment Rejection Sampler (SIRS) to improve query efficiency in parallel masked diffusion models (MDMs). SIRS estimates the log acceptance probability using only one randomly sampled increment, then applies a Bernoulli factory to decide accept/reject outcomes. By Rao‑Blackwellizing each increment and bounding the KL‑divergence, SIRS reduces bias while maintaining parallel decoding performance.

By Shiyuan Zhang, Xuheng Li, Qiwei Di, Quanquan Gu