UnMaskFork scales test-time compute for MDLMs
UnMaskFork is a new test-time scaling framework that formulates the unmasking trajectory of Masked Diffusion Language Models (MDLMs) as a search tree. By utilizing Monte Carlo Tree Search with deterministic partial unmasking actions, the framework achieves efficient state space exploration and outperforms scaling baselines on coding and math reasoning benchmarks.
Applying search to diffusion-based generation has traditionally been held back by stochastic path generation, but UnMaskFork's deterministic branching elegantly adapts MCTS to this architecture.
- –**Deterministic Action Branching** eliminates the random noise transitions of typical diffusion generation, allowing structured search algorithms to systematically evaluate alternative generation paths.
- –**State Caching Efficiency** is greatly enhanced since deterministic transitions enable caching of early unmasking states across different search branches.
- –**Competitive Reasoning Performance** on coding and math tasks suggests that diffusion-based models, when scaled at test time, can offer viable alternatives to standard autoregressive reasoning models.
DISCOVERED
1d ago
2026-07-21
PUBLISHED
1d ago
2026-07-21
RELEVANCE
AUTHOR
hardmaru