With --use-replayssm and speculative decoding, Qwen4Exp's Gated DeltaNet layers verify the
draft window from a read-only checkpoint and keep a per-token replay record
[correction(V), normalized key(K), gate(1)] in fp32. After sampling, one commit replays the
accepted tokens and writes the recurrent state once (plus the block-boundary state in align
mode), instead of snapshotting the state after every draft position. The PLE dilated short
conv follows the same protocol (accepted-suffix compaction). num_speculative_blocks = 0,
so no per-draft Mamba blocks are reserved.
- GDN verify/commit kernels: model_executor/layers/mamba/gdn/recoverssm_gdn.py
- metadata/backends: v1/attention/backends/gdn_recoverssm.py, ple_recoverssm.py
- the verify reads strided q/k/v views of the conv output and writes in place
- builders declare AttentionCGSupport.NEVER: FULL_AND_PIECEWISE falls back to PIECEWISE;
the fallback now also counts breakable CUDA graphs (empty splitting_ops, with or
without torch.compile) as piecewise
attention instead of dropping to NONE
- the generic Mamba metadata builder skips the Mamba2 ReplaySSM ring-buffer workspaces
when --use-replayssm selects RecoverSSM (the PLE short conv uses that builder)
- tests: GDN verify/commit vs the native kernels (fp32 and bf16 state, align boundaries,
mixed and ragged batches, extreme gates), PLE vs token-by-token decode, config selection
Signed-off-by: Jürgen Schmied <juergenschmied70@gmail.com>
Co-authored-by: Claude <noreply@anthropic.com>
