KernelBench hard · RTX PRO 6000

KDA CUTLASS GPT-5.6 Sol

manually audited: clean

Genuine from-scratch six-kernel Triton chunk pipeline for KDA forward on B200 (SM100), written in a fast ~20-minute session. Same design family as the model's clean H100 cell tonight (chunked WY transform with the k*exp(+gc) / k*exp(-gc) split-exponential trick) but a distinct kernel decomposition, not a copy: 64-wide local gate cumsum; 16x16 diagonal-tile forward-substitution solve; a separate compose kernel that assembles the full 64x64 block-triangular inverse from the four 16x16 diagonal inverses via block back-substitution (tl.dot chains); w/u/kg projection; a sequential inter-chunk state scan that materializes per-chunk 128x128 states and v_new; and a fully parallel per-chunk output kernel. Three earlier-iteration kernels (naive token recurrence, monolithic 64x64 forward substitution, fused single-pass state+output) remain in the file as dead code, never launched by forward(). Fresh torch.empty workspace every call, no memoization, no data_ptr identity gate, no CUDA graphs — empirical recompute test not required. No fla imports or forbidden ops. peak_fraction 0.0064 is honest: absolute ms (0.129/0.200/0.262/0.142) is actually FASTER than the H100 sibling (0.144/0.282/0.393/0.145); the lower fraction is B200's much larger peak denominator, not weaker work. template_mutated=false.

20260721_182112_codex_gpt-5.6-sol_02_kda_cutlass