Commit Graph

4 Commits

Author SHA1 Message Date
31ebe4f2db Wire NVFP4 fused router kernel into e2e single-shot pipeline
- Add dense_router_dispatch_nvfp4_fused() in dense_router_decode.py:
  single-kernel NVFP4 blockscaled GEMM + fused router epilogue
- Router.load_nvfp4_fused_gate(): stores raw NVFP4 tensors for fused path
- Router._run_dense_impl() dispatch priority: fused > 2-kernel > BF16
- single_shot_inference.py: loads raw NVFP4 gate weights for fused kernel
  instead of building Nvfp4Linear (which was the 2-kernel path)
- Fix selection sort bug in nvfp4_fused_router_kernel.py: pass 0 was
  missing t_s/t_i/t_a temp save before swap, causing undefined vars
- Export dense_router_dispatch_nvfp4_fused from __init__.py
2026-06-01 09:47:48 +00:00
cf2b7ab7ec feat: NVFP4 gate projection for router (replaces BF16 cuBLAS)
The dense router now uses NVFP4 GEMM via Nvfp4Linear for the gate
projection when NVFP4 scales are available in the checkpoint. This
replaces the BF16 cuBLAS GEMM with Blackwell SM100 tensor-core
NVFP4 acceleration.

Changes:
- dsv4/layers/router.py: add gate_lin (Nvfp4Linear) alongside W_gate
  fallback. New load_nvfp4_gate() method.
- dsv4/kernels/router/dense_router_decode.py: add
  dense_router_dispatch_nvfp4() using Nvfp4Linear + activation_topk
- dsv4/kernels/router/__init__.py: export new function
- single_shot_inference.py: load NVFP4 gate weights when available,
  fall back to BF16 when not
2026-06-01 05:58:56 +00:00
abfe4485f7 Router: full kernel stack — hash, topk, activation+topk, dense decode/prefill
Step 1: Hash router (hash_router.cu)
- One thread per token, gather from [vocab_size, k] LUT
- Uniform 1/k weights, FP32 output
- 3 MB LUT fits in L2 for repeated decode calls

Step 2: topk_select.cu — general top-k primitive
- Per-thread register min-heap (k=6, compile-time unrolled)
- Shared memory merge: thread 0 merges 64 partial heaps
- Tie-breaking: lower index wins on equal scores
- Reusable by CSA indexer

Step 3: activation_topk.cu — fused sqrt(softplus) + bias + topk + renorm
- Single kernel: all 6 steps of the router math, no intermediate buffers
- Numerically stable softplus: max(x,0) + log1p(exp(-|x|))
- Per-thread heap with unbiased activation co-stored
- Shared memory merge → sort descending → renormalize → store

Step 4: dense_router_decode.py — CuTeDSL fused GEMM kernel (skeleton)
- BF16 GEMM with tcgen05.mma, FP32 accumulator
- Custom epilogue: activation + bias + top-k (structure defined, needs TMA/MMA boilerplate)
- Dispatch: N<=64 uses fused decode, N>64 uses prefill path

Step 5: dense_router_prefill.py — prefill path
- torch.nn.functional.linear for GEMM (DeepGEMM integration deferred)
- Calls activation_topk for fused post-GEMM processing

Step 6: Router class + ops/router.py + test_router.py
- Router: construction-time mode (dense/hash), weight loading, custom_op dispatch
- ops/router.py: torch.library.custom_op wrappers, integer-keyed registry
- test_router.py: spec oracle tests (DO NOT RUN — Carmine is testing Stage C)

Test strategy: each kernel tested against its mathematical spec in FP32.
No reference implementation, no two debug streams. The oracle IS the math.
2026-05-21 21:54:05 +00:00
3fb3c925af Restructure: cutedsl/ -> dsv4/ with proper layering
- Split bridge.py -> ops/quantize.py, ops/layouts.py, ops/gemm_runner.py
- Renamed classes: CuTeDSLNvfp4Linear -> Nvfp4Linear, etc.
- Moved kernel code to dsv4/kernels/ (gemm, attention, compressor, decode, cuda)
- Moved PyTorch bridges to dsv4/ops/
- Moved nn.Module layers to dsv4layers/
- Moved reference implementations to dsv4/reference/
- Moved vendored CUTLASS code to vendored/
- Archived ~190 debug tests to tests/archive/
- Kept ~15 canonical tests in tests/unit/
- Updated all import paths
- Added stubs for future components (model/, cache/, loader/)
- Updated pyproject.toml: dsv4-inference package name
2026-05-21 17:30:44 +00:00