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arxiv: 2605.18817 · v1 · pith:XH4SJKOInew · submitted 2026-05-12 · 💻 cs.LG

Multi-Token Residual Prediction

Pith reviewed 2026-05-20 22:40 UTC · model grok-4.3

classification 💻 cs.LG
keywords diffusion language modelsmulti-token denoisingresidual predictionspeculative decodinginference accelerationlogit distributionnon-autoregressive generation
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The pith

Diffusion language models can denoise multiple tokens per forward pass by predicting residuals between adjacent logit distributions from hidden states.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper introduces Multi-Token Residual Prediction to let diffusion language models decode more than one token per denoising step without a second full backbone pass. It rests on the observation that logit distributions change only modestly from one step to the next, so a small module can forecast that change directly from the current hidden states. This produces two operating modes: direct use of the predicted logits for a controllable speed-quality trade-off, and speculative verification against the backbone for acceleration that preserves exact output quality. A reader would care because current diffusion models are limited in parallelism by the need to run the full network repeatedly; removing that bottleneck would make them competitive with autoregressive generators on long outputs.

Core claim

MRP is a lightweight module attached to a diffusion language model backbone that predicts the residual between the logit distribution at the current denoising step and the distribution at the next step, using only the hidden states already computed by the backbone. Because adjacent logit distributions are similar, the residual is small and can be modeled accurately by a cheap head rather than by running the entire network again. The corrected logits then support either direct multi-token denoising or speculative proposals that are verified for exact equivalence to the original model.

What carries the argument

Multi-Token Residual Prediction (MRP) module, which forecasts the logit residual between successive denoising steps from the backbone hidden states.

If this is right

  • Direct decoding mode allows a continuous quality-speed curve by accepting more or fewer MRP proposals.
  • Speculative decoding mode guarantees output identical to the original model while still reducing the number of full backbone evaluations.
  • The method scales from 1.7B to 8B parameter models on both reasoning and code-generation tasks.
  • No change to the pre-trained backbone weights is required; only the small MRP head is trained.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • The same residual-prediction idea could be tested in other iterative refinement processes such as masked image generation where consecutive predictions are also highly correlated.
  • If the hidden states already encode most of the next-step information, further compression of the MRP head itself may be possible without retraining.
  • The approach suggests that diffusion models may not need full re-inference at every step, opening the door to hybrid schedules that mix full and residual steps dynamically.

Load-bearing premise

Logit distributions at adjacent denoising steps are similar enough that their difference can be predicted accurately from the current hidden states alone.

What would settle it

Run MRP on a held-out set of denoising trajectories and measure whether the predicted logits produce token sequences whose quality matches the original backbone within the paper's reported thresholds; if the quality gap exceeds those thresholds, the claimed speedups are not achievable without loss.

Figures

Figures reproduced from arXiv: 2605.18817 by Ang Li, Bowen Peng, Haoqi Zhang, Qian Wang, Rahul Chalamala, Yucheng Lu, Yufeng Xu, Zeshen Zhang, Zishuo Bao.

Figure 1
Figure 1. Figure 1: The figure above illustrates the training and inference pipeline of our multi-token residual prediction (MRP) method. [PITH_FULL_IMAGE:figures/full_fig_p002_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: Magnitudes of the per-step residual versus the full backbone state, measured on GSM8K and averaged per entry (RMS). The [PITH_FULL_IMAGE:figures/full_fig_p004_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: Effect of MRP depth on SDAR-1.7B. We sweep the number of MRP transformer layers [PITH_FULL_IMAGE:figures/full_fig_p009_3.png] view at source ↗
read the original abstract

Diffusion Language Models (DLMs) generate text by iteratively denoising masked token sequences, offering a tradeoff between parallelism and quality compared to autoregressive models. In current practice, the number of tokens decoded per step is controlled by a confidence threshold, and quality degrades monotonically as more tokens are denoised per step. We introduce Multi-token Residual Prediction (MRP), a lightweight module that enables dependency-aware multi-token denoising within a single backbone forward pass. MRP exploits a key property of the denoising process: the logit distributions at adjacent denoising steps are remarkably similar. Rather than running the backbone a second time to obtain the next-step logits, MRP predicts the residual between steps from the backbone's hidden states, effectively denoising more tokens per backbone forward at a fraction of the cost. We deploy MRP in two inference modes: direct decoding, which uses the corrected logits without verification for a tunable quality--speed tradeoff; and speculative decoding, which verifies MRP's proposals against the backbone for lossless acceleration. Experiments on SDAR models at the 1.7B, 4B, and 8B scales across reasoning and code generation benchmarks demonstrate up to $1.42\times$ lossless speedup in SGLang.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 2 minor

Summary. The paper introduces Multi-Token Residual Prediction (MRP), a lightweight auxiliary module for diffusion language models (DLMs). MRP predicts the residual between logit distributions at adjacent denoising steps directly from the backbone hidden states, enabling dependency-aware multi-token denoising in a single forward pass. The approach is deployed in direct-decoding mode (tunable quality-speed tradeoff) and speculative-decoding mode (lossless acceleration via verification). Experiments on SDAR models at 1.7B, 4B, and 8B scales report up to 1.42× lossless speedup on reasoning and code-generation benchmarks.

Significance. If the core empirical observation holds and residual prediction remains sufficiently accurate when multiple tokens are updated per step, MRP offers a practical, low-overhead route to higher parallelism in DLM inference without sacrificing the lossless property in the speculative path. The method is notable for its simplicity—an independent lightweight predictor rather than architectural changes to the backbone—and for explicitly separating the quality-speed tradeoff from the acceleration claim.

major comments (2)
  1. [Experiments] Experiments section: the abstract and results claim up to 1.42× lossless speedup across three model scales, yet no information is provided on the number of evaluation runs, standard deviations, exact baseline implementations (including confidence-threshold schedules), or hardware/software stack. This absence makes it impossible to assess whether the reported factor is robust or sensitive to implementation details.
  2. [Method] Method and speculative-decoding description: the central claim that MRP sustains high acceptance rates relies on the logit distributions remaining 'remarkably similar' even when multiple tokens are denoised per step. When the sequence fed to the next backbone call differs in several positions, the true residual can enlarge; the manuscript should include either an ablation measuring prediction error and acceptance rate as a function of tokens-per-step or a theoretical bound showing why error remains controlled.
minor comments (2)
  1. [Method] Notation: the distinction between the MRP module output and the final corrected logits should be made explicit with consistent symbols throughout the equations.
  2. [Method] Figure clarity: the diagram illustrating the single-pass residual prediction versus the two-pass baseline would benefit from explicit arrows showing which tensors are reused versus recomputed.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the constructive feedback. We address the major comments point by point below and indicate the revisions we will make to the manuscript.

read point-by-point responses
  1. Referee: [Experiments] Experiments section: the abstract and results claim up to 1.42× lossless speedup across three model scales, yet no information is provided on the number of evaluation runs, standard deviations, exact baseline implementations (including confidence-threshold schedules), or hardware/software stack. This absence makes it impossible to assess whether the reported factor is robust or sensitive to implementation details.

    Authors: We agree that the current manuscript lacks sufficient details for full reproducibility and robustness assessment. In the revised version, we will expand the Experiments section to report the number of evaluation runs (conducted with 3 independent random seeds), include standard deviations alongside the speedup figures, provide exact specifications of the baseline implementations including the confidence-threshold schedules, and detail the hardware (NVIDIA H100 GPUs) and software stack (SGLang version and dependencies). These additions will allow readers to better evaluate the stability of the reported speedups. revision: yes

  2. Referee: [Method] Method and speculative-decoding description: the central claim that MRP sustains high acceptance rates relies on the logit distributions remaining 'remarkably similar' even when multiple tokens are denoised per step. When the sequence fed to the next backbone call differs in several positions, the true residual can enlarge; the manuscript should include either an ablation measuring prediction error and acceptance rate as a function of tokens-per-step or a theoretical bound showing why error remains controlled.

    Authors: We acknowledge the value of this request for stronger validation of the multi-token regime. In the revised manuscript we will add an ablation study that reports MRP prediction error (measured via KL divergence to the true residual) and speculative-decoding acceptance rates as a function of tokens updated per step (sweeping from 1 to 8 tokens). This empirical analysis will directly address whether error growth remains controlled. Deriving a general theoretical bound is difficult without strong assumptions on the diffusion trajectory, so we opt for the requested ablation instead. revision: yes

Circularity Check

0 steps flagged

No significant circularity; derivation is self-contained

full rationale

The paper introduces MRP as an independent lightweight module trained to predict residuals between adjacent-step logit distributions from backbone hidden states, exploiting an empirically observed similarity in the denoising process rather than any self-referential equation or fitted parameter renamed as a prediction. No load-bearing step reduces by the paper's own equations or self-citation to its inputs; the central claim rests on training a separate predictor and verifying it against external benchmarks, making the derivation self-contained.

Axiom & Free-Parameter Ledger

1 free parameters · 1 axioms · 1 invented entities

The central claim depends on the stated similarity of adjacent-step logit distributions and on the effectiveness of a newly introduced lightweight residual predictor whose parameters are not characterized in the abstract.

free parameters (1)
  • MRP module parameters
    The lightweight residual predictor is a trainable module whose weights are fitted to data; the abstract does not specify how many or how they are trained.
axioms (1)
  • domain assumption Logit distributions at adjacent denoising steps are remarkably similar.
    This property is invoked as the key enabler that allows residual prediction to replace a second backbone forward pass.
invented entities (1)
  • MRP residual predictor module no independent evidence
    purpose: To predict the change in logits between denoising steps from hidden states
    A new lightweight network introduced by the paper; no independent evidence outside the reported experiments is provided.

pith-pipeline@v0.9.0 · 5757 in / 1215 out tokens · 38645 ms · 2026-05-20T22:40:44.562923+00:00 · methodology

discussion (0)

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Reference graph

Works this paper leans on

37 extracted references · 37 canonical work pages · 7 internal anchors

  1. [1]

    Spiffy: Multiplying diffusion llm accel- eration via lossless speculative decoding.arXiv preprint arXiv:2509.18085,

    Sudhanshu Agrawal, Risheek Garrepalli, Raghavv Goel, Mingu Lee, Christopher Lott, and Fatih Porikli. “Spiffy: Multiplying Diffusion LLM Acceleration via Lossless Speculative Decoding”. In:arXiv preprint arXiv:2509.18085 (2025)

  2. [2]

    Block Diffusion: Interpolating Between Autoregressive and Diffusion Language Models

    Marianne Arriola, Aaron Gokaslan, Justin T. Chiu, Zhihan Yang, Zhixuan Qi, Jiaqi Han, Subham Sekhar Sahoo, and Volodymyr Kuleshov. “Block Diffusion: Interpolating Between Autoregressive and Diffusion Language Models”. In: ICLR. 2025

  3. [3]

    Structured Denoising Diffusion Models in Discrete State-Spaces

    Jacob Austin, Daniel D. Johnson, Jonathan Ho, Daniel Tarlow, and Rianne van den Berg. “Structured Denoising Diffusion Models in Discrete State-Spaces”. In:NeurIPS. 2021

  4. [4]

    Program Synthesis with Large Language Models

    Jacob Austin, Augustus Odena, Maxwell Nye, Maarten Bosma, Henryk Michalewski, David Dohan, Ellen Jiang, Carrie Cai, Michael Terry, Quoc Le, and Charles Sutton. “Program Synthesis with Large Language Models”. In:arXiv preprint arXiv:2108.07732(2021)

  5. [5]

    https : //huggingface.co/datasets/BAAI/Infinity-Instruct

    BAAI.Infinity Instruct: Scaling Instruction Selection and Synthesis to Enhance Language Models. https : //huggingface.co/datasets/BAAI/Infinity-Instruct. 2024

  6. [6]

    Learning to Parallel: Accelerating Diffusion Large Language Models via Learnable Parallel Decoding

    Wenrui Bao, Zhiben Chen, Dan Xu, and Yuzhang Shang. “Learning to Parallel: Accelerating Diffusion Large Language Models via Learnable Parallel Decoding”. In:ICLR. 2026

  7. [7]

    Language models are few-shot learners

    Tom Brown, Benjamin Mann, Nick Ryder, Melanie Subbiah, Jared D Kaplan, Prafulla Dhariwal, Arvind Neelakantan, Pranav Shyam, Girish Sastry, Amanda Askell, et al. “Language models are few-shot learners”. In:Advances in neural information processing systems33 (2020), pp. 1877–1901

  8. [8]

    GenQA: Generating Millions of Instructions from a Handful of Prompts

    Jiuhai Chen, Rifaa Qadri, Yuxin Wen, Neel Jain, John Kirchenbauer, Tianyi Zhou, and Tom Goldstein. “GenQA: Generating Millions of Instructions from a Handful of Prompts”. In:arXiv preprint arXiv:2406.10323(2024)

  9. [9]

    Evaluating Large Language Models Trained on Code

    Mark Chen, Jerry Tworek, Heewoo Jun, Qiming Yuan, Henrique Pondé de Oliveira Pinto, Jared Kaplan, Harri Edwards, Yuri Burda, Nicholas Joseph, Greg Brockman, et al. “Evaluating Large Language Models Trained on Code”. In:arXiv preprint arXiv:2107.03374(2021)

  10. [10]

    Sdar: A syn- ergistic diffusion-autoregression paradigm for scalable sequence generation.arXiv preprint arXiv:2510.06303,

    Shuang Cheng, Yihan Bian, Dawei Liu, Linfeng Zhang, Qian Yao, Zhongbo Tian, Wenhai Wang, Qipeng Guo, Kai Chen, Biqing Qi, and Bowen Zhou. “SDAR: A Synergistic Diffusion-AutoRegression Paradigm for Scalable Sequence Generation”. In:arXiv preprint arXiv:2510.06303(2025)

  11. [11]

    Speculative Diffusion Decoding: Accelerating Language Generation through Diffusion

    Jacob K. Christopher, Brian R. Bartoldson, Tal Ben-Nun, Michael Cardei, Bhavya Kailkhura, and Ferdinando Fioretto. “Speculative Diffusion Decoding: Accelerating Language Generation through Diffusion”. In:NAACL. 2025

  12. [12]

    Training Verifiers to Solve Math Word Problems

    Karl Cobbe, Vineet Kosaraju, Mohammad Bavarian, Mark Chen, Heewoo Jun, Lukasz Kaiser, Matthias Plappert, Jerry Tworek, Jacob Hilton, Reiichiro Nakano, Christopher Hesse, and John Schulman. “Training Verifiers to Solve Math Word Problems”. In:arXiv preprint arXiv:2110.14168(2021)

  13. [13]

    Self speculative decoding for diffusion large language models

    Yifeng Gao, Ziang Ji, Yuxuan Wang, Biqing Qi, Hanlin Xu, and Linfeng Zhang. “Self Speculative Decoding for Diffusion Large Language Models”. In:arXiv preprint arXiv:2510.04147(2025)

  14. [14]

    Deep residual learning for image recognition

    Kaiming He, Xiangyu Zhang, Shaoqing Ren, and Jian Sun. “Deep residual learning for image recognition”. In: Proceedings of the IEEE conference on computer vision and pattern recognition. 2016, pp. 770–778. 10

  15. [15]

    Measuring Mathematical Problem Solving with the MATH Dataset

    Dan Hendrycks, Collin Burns, Saurav Kadavath, Akul Arora, Steven Basart, Eric Tang, Dawn Song, and Jacob Steinhardt. “Measuring Mathematical Problem Solving with the MATH Dataset”. In:NeurIPS Datasets and Benchmarks. 2021

  16. [16]

    Wide-In, Narrow-Out: Revokable Decoding for Efficient and Effective DLLMs

    Feng Hong, Geng Yu, Yushi Ye, Haicheng Huang, Huangjie Zheng, Ya Zhang, Yanfeng Wang, and Jiangchao Yao. “Wide-In, Narrow-Out: Revokable Decoding for Efficient and Effective DLLMs”. In:arXiv preprint arXiv:2507.18578 (2025)

  17. [17]

    Residual Context Diffusion Language Models

    Yuezhou Hu, Harman Singh, Monishwaran Maheswaran, Haocheng Xi, Coleman Hooper, Jintao Zhang, Aditya Tomar, Michael W Mahoney, Sewon Min, Mehrdad Farajtabar, et al. “Residual Context Diffusion Language Models”. In:arXiv preprint arXiv:2601.22954(2026)

  18. [18]

    Accelerating Diffusion LLMs via Adaptive Parallel Decoding

    Daniel Israel, Guy Van den Broeck, and Aditya Grover. “Accelerating Diffusion LLMs via Adaptive Parallel Decoding”. In:NeurIPS. 2025

  19. [19]

    Diffuspec: Unlocking diffusion language models for speculative decoding.arXiv preprint arXiv:2510.02358, 2025

    Guanghao Li, Zhihui Fu, Min Fang, Qibin Zhao, Ming Tang, Chun Yuan, and Jun Wang. “DiffuSpec: Unlocking Diffusion Language Models for Speculative Decoding”. In:arXiv preprint arXiv:2510.02358(2025)

  20. [20]

    Diffusion Language Models Know the Answer Before Decoding

    Pengxiang Li, Yefan Zhou, Dilxat Muhtar, Lu Yin, Shilin Yan, Li Shen, Soroush Vosoughi, and Shiwei Liu. “Diffusion Language Models Know the Answer Before Decoding”. In:NeurIPS. 2025

  21. [21]

    EAGLE: Speculative Sampling Requires Rethinking Feature Uncertainty

    Yuhui Li, Fangyun Wei, Chao Zhang, and Hongyang Zhang. “Eagle: Speculative sampling requires rethinking feature uncertainty”. In:arXiv preprint arXiv:2401.15077(2024)

  22. [22]

    Let’s Verify Step by Step

    Hunter Lightman, Vineet Kosaraju, Yura Burda, Harri Edwards, Bowen Baker, Teddy Lee, Jan Leike, John Schulman, Ilya Sutskever, and Karl Cobbe. “Let’s Verify Step by Step”. In:ICLR. 2024

  23. [23]

    DeepSeek-V3 Technical Report

    Aixin Liu, Bei Feng, Bing Xue, Bingxuan Wang, Bochao Wu, Chengda Lu, Chenggang Zhao, Chengqi Deng, Chenyu Zhang, Chong Ruan, et al. “Deepseek-v3 technical report”. In:arXiv preprint arXiv:2412.19437(2024)

  24. [24]

    Discrete Diffusion Modeling by Estimating the Ratios of the Data Distribution

    Aaron Lou, Chenlin Meng, and Stefano Ermon. “Discrete Diffusion Modeling by Estimating the Ratios of the Data Distribution”. In:ICML. 2024

  25. [25]

    Fast-Decoding Diffusion Language Models via Progress-Aware Confidence Schedules

    Amr Mohamed, Yang Zhang, Michalis Vazirgiannis, and Guokan Shang. “Fast-Decoding Diffusion Language Models via Progress-Aware Confidence Schedules”. In:arXiv preprint arXiv:2512.02892(2025)

  26. [26]

    Softmax is1 /2-Lipschitz: A tight bound across all ℓ𝑝 norms

    Pravin Nair. “Softmax is1 /2-Lipschitz: A tight bound across all ℓ𝑝 norms”. In:arXiv preprint arXiv:2510.23012(2025)

  27. [27]

    Large Language Diffusion Models

    Shen Nie, Fengqi Zhu, Zebin You, Xiaolu Zhang, Jingyang Ou, Jun Hu, Jun Zhou, Yankai Lin, Ji-Rong Wen, and Chongxuan Li. “Large Language Diffusion Models”. In:NeurIPS. 2025

  28. [28]

    Simple and Effective Masked Diffusion Language Models

    Subham Sekhar Sahoo, Marianne Arriola, Yair Schiff, Aaron Gokaslan, Edgar Marroquin, Justin T. Chiu, Alexander Rush, and Volodymyr Kuleshov. “Simple and Effective Masked Diffusion Language Models”. In:NeurIPS. 2024

  29. [29]

    Fast and Fluent Diffusion Language Models via Convolutional Decoding and Rejective Fine-tuning

    Yeongbin Seo, Dongha Lee, Jaehyung Kim, and Jinyoung Yeo. “Fast and Fluent Diffusion Language Models via Convolutional Decoding and Rejective Fine-tuning”. In:NeurIPS. 2025

  30. [30]

    https://huggingface

    Teknium.OpenHermes 2.5: An Open Dataset of Synthetic Data for Generalist LLM Assistants. https://huggingface. co/datasets/teknium/OpenHermes-2.5. 2024

  31. [31]

    The Mamba in the Llama: Distilling and Accelerating Hybrid Models

    Junxiong Wang, Daniele Paliotta, Avner May, Alexander M. Rush, and Tri Dao. “The Mamba in the Llama: Distilling and Accelerating Hybrid Models”. In:NeurIPS. 2024

  32. [32]

    Diffusion LLMs Can Do Faster-Than-AR Inference via Discrete Diffusion Forcing

    Xu Wang, Chenkai Xu, Yijie Jin, Jiachun Jin, Hao Zhang, and Zhijie Deng. “Diffusion LLMs Can Do Faster-Than-AR Inference via Discrete Diffusion Forcing”. In:ICLR. 2026

  33. [33]

    Fast- dllm v2: Efficient block-diffusion llm.arXiv preprint arXiv:2509.26328,

    Chengyue Wu, Hao Zhang, Shuchen Xue, Shizhe Diao, Yonggan Fu, Zhijian Liu, Pavlo Molchanov, Ping Luo, Song Han, and Enze Xie. “Fast-dllm v2: Efficient block-diffusion llm”. In:arXiv preprint arXiv:2509.26328(2025)

  34. [34]

    Fast-dLLM: Training-free Acceleration of Diffusion LLM by Enabling KV Cache and Parallel Decoding

    Chengyue Wu, Hao Zhang, Shuchen Xue, Zhijian Liu, Shizhe Diao, Ligeng Zhu, Ping Luo, Song Han, and Enze Xie. “Fast-dLLM: Training-free Acceleration of Diffusion LLM by Enabling KV Cache and Parallel Decoding”. In:ICLR. 2026

  35. [35]

    Qwen3 Technical Report

    An Yang, Anfeng Li, Baosong Yang, Beichen Zhang, Binyuan Hui, Bo Zheng, Bowen Yu, Chang Gao, Chengen Huang, Chenxu Lv, et al. “Qwen3 technical report”. In:arXiv preprint arXiv:2505.09388(2025)

  36. [36]

    Dream 7B: Diffusion Large Language Models

    Jiacheng Ye, Zhihui Xie, Lin Zheng, Jiahui Gao, Zirui Wu, Xin Jiang, Zhenguo Li, and Lingpeng Kong. “Dream 7B: Diffusion Large Language Models”. In:arXiv preprint arXiv:2508.15487(2025)

  37. [37]

    Sglang: Efficient execution of structured language model programs

    Lianmin Zheng, Liangsheng Yin, Zhiqiang Xie, Chuyue Sun, Jeff Huang, Cody H Yu, Shiyi Cao, Christos Kozyrakis, Ion Stoica, Joseph E Gonzalez, et al. “Sglang: Efficient execution of structured language model programs”. In:Advances in neural information processing systems37 (2024), pp. 62557–62583. 11 A Related Work A.1 Diffusion Language Models Discrete-se...