- delete the warp-per-row kernel and the (6912,1536) M=2/4/8 dispatch table; under rotated cold weights the warp path is 2-6% slower than CTA reuse at M=2/4, and the table had been tuned against L2-resident timing
- a single CTA-reuse kernel now serves all M in [1, 8]; block size is 256 threads for M in [1, 7] and 128 for M=8, where the shorter shared-memory reduction tree wins
- document in docs/developer/swiglu_benchmark.md that the earlier operator numbers were L2-resident: the fused kernel sits at the dual-stream cold-read floor (702 vs 699 GB/s at (6912,1536); 369 vs 370 GB/s at (11008,4096)) and wide matrices cap at ~370-400 GB/s even for pure reads, so the reported M=8 -23% regression does not survive the cold regime
- update docs/developer/cuda_kernels.md accordingly
Benchmark: L20 (sm_89), PyTorch 2.11.0+cu128, rotated weight copies >= 240 MB to defeat the 96 MB L2; end-to-end through the built module at (6912,1536) reaches 738-752 GB/s for M in [1, 4] and 702 GB/s at M=8, about +8% at M=2/4 and +6% at M=8 over the removed warp path
- delete the warp-tiled kernel and both per-shape (N,K) selector tables; block size is 256 threads everywhere except M=8 with N*K <= 12 MiB, which keeps a 128-thread CTA
- HBM-streaming measurements (weight copies rotated through L2, the real decode regime) show the variants within ~3% on L20 because the kernel is bandwidth-bound; the retired tables were tuned against an L2-resident loop and sometimes picked the slowest variant ((2048,8192) M=8: coop128 6% slower than coop256)
- a shape no longer switches kernels (and accumulation order) with M, removing one shape-dependent nondeterminism source
- remove the stale split-K launcher comment
- move bf16_gemv.cu and bf16_swiglu.cu from csrc/kernels/gemv/ to csrc/kernels/ beside rotary_emb.cu; the family keeps no shared headers
- rename test_bf16_gemv_matches_half_cta_edge_bands to test_bf16_gemv_matches_m8_edge_bands and update docs/developer/cuda_kernels.md
Benchmark: L20 (sm_89), PyTorch 2.11.0+cu128, interleaved CUDA-event timing with rotated weight copies exceeding the 96MB L2; variant spread <=3% across 14 shapes x M in {1,2,4,8}, and the retained rule wins 5-9% at M=8 small weights ((512,3584), (1536,1536), (6912,1536))
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