LLM-generated GPU kernels pass weak benchmarks and ship real bugs.

Using op-schema-aware seeded fuzzing against a high-precision fp64 CPU reference on 24 Triton kernels, 15 correct and 9 intentionally buggy, the method caught all 9 buggy variants and passed all 15 controls across five GPU classes (arXiv:2606.20128). Standard kernel benchmarks would have missed those bugs. If you're trusting a kernel-generation leaderboard, or your own model's CUDA output, the test suite under it is probably too weak to catch the failures that matter.