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from typeguard import typechecked
import numpy as np
try:
    import torch
    torch_available = True
except ImportError:
    torch_available = False
from cuda import cuda
try:
    import cupy as cp
    cupy_available = True
except ImportError:
    cupy_available = False
import cutlass


# @typechecked
class TensorRef:
    """
    Python Wrapper for cutlass.TensorRef
    """
    def __init__(self, tensor, dtype, layout) -> None:
        if isinstance(tensor, np.ndarray):
            ptr = cuda.CUdeviceptr(tensor.__array_interface__['data'][0])
        elif torch_available and isinstance(tensor, torch.Tensor):
            ptr = cuda.CUdeviceptr(tensor.data_ptr())
        elif cupy_available and isinstance(tensor, cp.ndarray):
            ptr = cuda.CUdeviceptr(int(tensor.data.ptr))
        elif isinstance(tensor, cuda.CUdeviceptr):
            ptr = tensor
        elif isinstance(tensor, int):
            ptr = cuda.CUdeviceptr(tensor)
        else:
            raise NotImplementedError(tensor)
        
        # the dtype(0) is used to overload between different data types 
        # with the same layout
        self.tensor_ref = cutlass.get_tensor_ref(int(ptr), dtype(0), layout)
