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import numpy as np
import pytest

import tvm
import tvm.testing
from tvm import te

# These tests exercise the PyTorch DLPack interop path; skip the whole module
# when torch is unavailable.
pytest.importorskip("torch")


def test_from_dlpack_shape_one():
    # A test case for the issue https://github.com/pytorch/pytorch/issues/99803
    import torch
    from torch.utils.dlpack import to_dlpack

    tgt = tvm.target.Target(target="llvm", host="llvm")

    rows = 1
    a = tvm.runtime.from_dlpack(to_dlpack(torch.randn(rows, 16)))

    A = te.placeholder((rows, 16), name="A")
    B = te.placeholder((rows, 16), name="B")
    C = te.compute(A.shape, lambda i, j: A[i, j] + B[i, j], name="C")

    fadd = tvm.compile(te.create_prim_func([A, B, C]), target=tgt)

    dev = tvm.device(tgt.kind.name, 0)

    b = tvm.runtime.tensor(np.random.uniform(size=(rows, 16)).astype(B.dtype), dev)
    c = tvm.runtime.tensor(np.zeros((rows, 16), dtype=C.dtype), dev)
    fadd(a, b, c)

    tvm.testing.assert_allclose(c.numpy(), a.numpy() + b.numpy())


def test_from_dlpack_strided():
    import torch
    from torch.utils.dlpack import to_dlpack

    rows = 1
    inp = torch.randn(rows, 16)
    a = tvm.runtime.from_dlpack(to_dlpack(inp))
    view = a._create_view((2, 8))

    np.testing.assert_equal(inp.numpy().reshape(2, 8), view.numpy())


if __name__ == "__main__":
    tvm.testing.main()