Align tokenizer fitting and loss reduction with the effective training dataset, and fail early when FAST supervision cannot be produced safely.
Co-authored-by: Cursor <cursoragent@cursor.com>
_fast_ce/_shifted_ce were renamed to _fast_lin_ce/_shifted_lin_ce and changed
from logits-based to Liger fused-linear-CE (hidden @ lm_head_weightᵀ). Update
the tests via thin adapters that pass an identity lm_head_weight (so the
computed logits equal the provided ones), run on CUDA (Liger is GPU-only) and
skip otherwise, and loosen the allclose tolerance to absorb GPU-vs-CPU float
noise on the tiny losses.
Co-authored-by: Cursor <cursoragent@cursor.com>
Select only supervised text and FAST action-code positions before cross-entropy to avoid full-vocabulary loss tensors over padded sequences.
Co-authored-by: Cursor <cursoragent@cursor.com>
Mask the FAST auxiliary loss to discrete action-code tokens so wrapper formatting tokens do not affect action co-training.
Co-authored-by: Cursor <cursoragent@cursor.com>
pepijn