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Mojo function

cast_fp32_to_fp4e2m1

def cast_fp32_to_fp4e2m1[width: SIMDLength, //](x: SIMD[DType.float32, width]) -> UInt32

Converts eight float32 values to a packed FP4 E2M1 word using SM100 PTX instructions.

Issues four cvt.rn.satfinite.e2m1x2.f32 PTX instructions to convert pairs of float32 values to 4-bit FP4 E2M1, packing the results into a single UInt32.

Constraints:

Requires NVIDIA GPU with SM100 or newer (B200 and above).

Parameters:

width (SIMDLength): Must be 8; each call converts exactly eight float32 values.

Args:

x (SIMD[DType.float32, width]): Eight float32 input values to convert.

Returns:

UInt32: A UInt32 with the eight FP4 E2M1 nibbles packed in byte order.