For the complete documentation index, see llms.txt. Markdown versions of all pages are available by appending .md to any URL (e.g. /get-started.md).

Mojo function

get_scaling_kind

def get_scaling_kind[a_type: DType, scales_dtype: DType, SF_VECTOR_SIZE: Int, b_type: DType]() -> UMMAKind

Selects the UMMA kind for a same-format block-scaled matmul.

block_scaled_umma_kind plus the scale-factor vector-size check. Rejects the mixed W4A8 pair: only the grouped 1D-1D kernel implements the padded FP4 TMA copy that mixed operands need, and it infers its kind directly.

Parameters:

• ​a_type (DType): A operand element type (uint8 for MXFP4/NVFP4, float8_e4m3fn for MXFP8).
• ​scales_dtype (DType): Scale-factor element type.
• ​SF_VECTOR_SIZE (Int): Number of elements each scale factor covers.
• ​b_type (DType): B operand element type; must equal a_type.

Returns:

UMMAKind: The UMMAKind matching the provided type combination.