cs.LGOct 15, 2026

TIPS: A Tiny Inference-time Policy for Scaling in Diffusion Language Models

Authors: Ya-Shi Zhang, Jian Tang, Pierre-André Noël, Oleksiy Ostapenko

Organizations: ServiceNow AI Research · Mila - Quebec AI Institute · HEC Montréal

Abstract

Masked diffusion language models expose an inference-time choice: which positions become visible after each denoising pass. Many existing decoding methods use hand-designed rules or require visibility to grow monotonically. We present a T\textbf{T}iny I\textbf{I}nference-time P\textbf{P}olicy for S\textbf{S}caling (TIPS\textbf{TIPS}), an approximately 600600K-parameter controller that learns both unmasking and remasking while keeping the underlying language model frozen. TIPS uses visibility-aware confidence features and a shallow transformer to select which tokens should be visible, while a fixed schedule controls the expected visible fraction. We train the controller through supervised warmup followed by reinforcement learning from terminal correctness rewards. On GSM8K and MATH-500 with LLaDA-8B-Instruct, the full-canvas and two-block TIPS variants achieve 58.46%58.46\% and 57.97%57.97\% micro-averaged accuracy at a budget of 3232 decoder evaluations, exceeding the strongest baseline in our main comparison by 12.112.1 and 11.611.6 percentage points, respectively. Both variants are trained at a budget of 3232 evaluations and remain competitive at higher budgets without retraining. These results demonstrate that learning when to reveal and reconsider tokens can improve the accuracy-compute trade-off without updating the decoder backbone.

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