Some quantizers mark unquantized layers in a mixed-precision checkpoint
with an all-NUL comfy_quant placeholder tensor instead of omitting the
key. json.loads() misdetects the leading NUL bytes as UTF-32 and raises
UnicodeDecodeError; once that decode is patched around, the resulting
empty {} config still fails with "Unknown quantization format" because
the loader always requires an explicit format for any present marker.
Treat an all-NUL marker as if comfy_quant were absent so the layer loads
as a plain unquantized weight, matching the official MiniMax H3 nvfp4
AWQ text encoder.
Fixes#15400
linear_dtype in comfy_quant metadata can be used to set if the int4 op does
the matrix multiplication in int8 or int4, the default is int4 on GPUs that
support it with fallback to int8 for GPUs that don't.
* Implement mixed precision operations with a registry design and metadate for quant spec in checkpoint.
* Updated design using Tensor Subclasses
* Fix FP8 MM
* An actually functional POC
* Remove CK reference and ensure correct compute dtype
* Update unit tests
* ruff lint
* Implement mixed precision operations with a registry design and metadate for quant spec in checkpoint.
* Updated design using Tensor Subclasses
* Fix FP8 MM
* An actually functional POC
* Remove CK reference and ensure correct compute dtype
* Update unit tests
* ruff lint
* Fix missing keys
* Rename quant dtype parameter
* Rename quant dtype parameter
* Fix unittests for CPU build