- scripts/upcast_to_bf16.py: Converts mixed-precision V4 Pro to pure BF16
by upcasting all FP8 tensors (float8_e8m0fnu etc.) to bfloat16.
Needed because modelopt PTQ calibration crashes on Blackwell with FP8
kernels (DeepGEMM unsupported, Triton finegrained-fp8 has K mismatches).
- patches/patch_finegrained_fp8_blackwell.py: Patches transformers to
reject DeepGEMM on SM100+ (Blackwell), letting it fall back to Triton.
Note: the Triton fallback also fails during modelopt calibration on
quantized weights, so upcasting to BF16 is the working solution.
- Patch fixes iter_weights_for_calibration() for DeepseekV4Experts
(ModuleList quantizers vs singular)
- Run script uses official NVIDIA hf_ptq.py with FP8 source
- Documents flags to avoid (--low_memory_mode, wrong arg names)
