llama.cpp

99820049 - ggml-cuda : add d_state=64 fast path to SSM_SCAN kernel (#31818)

ggml-cuda : add d_state=64 fast path to SSM_SCAN kernel (#31818) Zamba2 and similar architectures use a state size of 64 in their recurrent-scan step, which fell outside the GPU kernel's existing fast paths (96, 128, 256). Every scan step was falling back to CPU, bottlenecking generation to 6-7 tok/s against the 50-70 tok/s band other architectures achieve on the same hardware. Add a 4th template instantiation for d_state=64, following the existing pattern; no change to the underlying math. Verified against the existing CPU-reference correctness harness with 3 new test cases built from Zamba2's real hyperparameters (28/28 passing). Measured ~35% throughput improvement (11 -> 15.1 tok/s) on Zamba2-7B- Instruct. Full parity with other architectures not yet reached - a separate, unrelated fraction of scan calls (~28%) still falls back to CPU for a cause not yet diagnosed. Assisted-by: Claude Sonnet 5 Co-authored-by: Sargentmajord <331229907+sargentmajord@users.noreply.github.com>