def _is_supported_dst_op_for_first_cat(
    dst_op: Operator,
) -> bool:
    """
    A helper function that returns True if the given dst_op is
    * a supported strided op; or
    * a view op that is only used by a supported stride op; or
    * a view op that is indirectly (via another single-dst view op) used
      by a supported strided op.
    Note that technically, this checking is not necessary, because we could
    let other passes process the likely fusion patterns related to
    concat + strided_op. However, it seems to be safer if we could add
    more tests similar to test_fuse_strided_cat_reshape_cat but with different
    strided ops such as gemm/layernorm/etc. To be conservative, we only
    enable the following patterns and will remove the restriction once we
    have more test coverage.
    """
    view_ops = ["reshape", "flatten", "dynamic_slice", "squeeze", "unsqueeze"]
    # FIXME: enable other ops with input_accessors
    supported_strided_ops = ["elementwise", "fused_elementwise"]

    def _supported_op_type(op_type):
        if op_type in supported_strided_ops:
            return True
        return op_type.startswith(("bmm_crr", "bmm_rrr"))

    dst_op_type = dst_op._attrs["op"]
    if _supported_op_type(dst_op_type):
        return True
    while dst_op_type in view_ops:
        dst_op_outputs = dst_op._attrs["outputs"]
        if len(dst_op_outputs) != 1:
            return False
        dst_op_output = dst_op_outputs[0]
        if dst_op_output._attrs["is_output"]:
            return False
        next_dst_ops = dst_op_output._attrs["dst_ops"]
        if len(next_dst_ops) != 1:
            return False
        dst_op = next_dst_ops[0]
        dst_op_type = dst_op._attrs["op"]
        if _supported_op_type(dst_op_type):
            return True
    return False
A helper function that returns True if the given dst_op is
* a supported strided op; or
* a view op that is only used by a supported stride op; or
* a view op that is indirectly (via another single-dst view op) used
by a supported strided op.
Note that technically, this checking is not necessary, because we could
let other passes process the likely fusion patterns related to
concat + strided_op. However, it seems to be safer if we could add
more tests similar to test_fuse_strided_cat_reshape_cat but with different
strided ops such as gemm/layernorm/etc. To be conservative, we only
enable the following patterns and will remove the restriction once we
have more test coverage.
python/aitemplate/compiler/transform/transform_memory_ops.py