DreamLM

DreamReasoner-8B: Block-size curriculum learning enables long-CoT reasoning in diffusion language models

Researchers introduce DreamReasoner-8B, an open-source block diffusion language model trained with a block-size curriculum learning strategy that gradually transitions from fine-grained to coarse-grained block sizes during training. The work identifies a critical failure mode: training with large block sizes severely degrades reasoning, while small block sizes preserve it. The proposed curriculum bridges this gap, achieving math and code reasoning performance competitive with Qwen3-8B while retaining the parallel decoding efficiency of block diffusion models. The model and code are publicly released.