forked from Karylab-cklius/vllm
Tests whether uninitialized padding rows in NVFP4 swizzled block scales (from scaled_fp4_quant's torch.empty) can contaminate real rows' GEMM output via flashinfer mm_fp4. Key scenarios: - Poison padding scale rows with NaN - Poison padding scale rows with max finite values (overflow) - Poison padding activation rows - Simulate CUDA graph replay with persistent scale tensor These target the suspected root cause of NaN in NVFP4 models with CUDA graphs, where capture sizes (1,2,4,8,...) are not multiples of 128, leaving uninitialized padding in the swizzled scale layout. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com> Signed-off-by: Tyler Michael Smith <tlrmchlsmth@gmail.com>