FastDiSS: Few-step Match Many-step Diffusion Language Model on Sequence-to-Sequence Generation

Dat Nguyen Cong, Tung Kieu, Hoang Thanh-Tung


Abstract
Self-conditioning has been central to the success of continuous diffusion language models, as it allows models to correct previous errors. Yet its ability degrades precisely in the regime where diffusion is most attractive for deployment: few-step sampling for fast inference. In this study, we show that when models only have a few denoising steps, inaccurate self-conditioning induces a substantial approximation gap; this mistake compounds across denoising steps and ultimately dominate the sample quality. To address this, we propose a novel training framework that handles these errors during learning by perturbing the self-conditioning signal to match inference noise, improving robustness to prior estimation errors. In addition, we introduce a token-level noise-awareness mechanism that prevents training from saturation, hence improving optimization. Extensive experiments across conditional generation benchmarks demonstrate that our framework surpasses standard continuous diffusion models while providing up to 400x faster inference speed, and remains competitive against other one-step diffusion frameworks.
Anthology ID:
2026.findings-acl.870
Volume:
Findings of the Association for Computational Linguistics: ACL 2026
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
Findings
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Publisher:
Association for Computational Linguistics
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Pages:
17572–17592
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URL:
https://preview.aclanthology.org/ingest-acl-workshops/2026.findings-acl.870/
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Cite (ACL):
Dat Nguyen Cong, Tung Kieu, and Hoang Thanh-Tung. 2026. FastDiSS: Few-step Match Many-step Diffusion Language Model on Sequence-to-Sequence Generation. In Findings of the Association for Computational Linguistics: ACL 2026, pages 17572–17592, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
FastDiSS: Few-step Match Many-step Diffusion Language Model on Sequence-to-Sequence Generation (Cong et al., Findings 2026)
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