namespace mlir {

class MLIRContext;

namespace TF {

SmallVector<int64_t, 4> ReversePermutation(ArrayRef<int64_t> permutation);

SmallVector<int64_t, 4> GetDataFormatPermutation(StringRef from, StringRef to);

// Shuffle elements in the `attr` according to the permutation. Optional
// `inner_size` allows to shuffle array attributes created from rank 2 tensors
// on outer dimension only.

  SmallVector<int64_t, 4> reverse(permutation.size());
  for (size_t i = 0; i < permutation.size(); ++i) {
    reverse[permutation[i]] = i;
  }
  return reverse;
}

SmallVector<int64_t, 4> GetDataFormatPermutation(StringRef from, StringRef to) {
  if (from == "NHWC" && to == "NCHW") {
    return {0, 3, 1, 2};
  } else if (from == "NCHW" && to == "NHWC") {
    return {0, 2, 3, 1};
  } else {
    return {};
  }
}

    // Transpose arguments into the target data format.
    Permutation args_permutation =
        GetDataFormatPermutation(data_format, target_data_format);

    // Transpose results back to the original data format.
    Permutation res_permutation =
        GetDataFormatPermutation(target_data_format, data_format);

    if (args_permutation.empty() || res_permutation.empty()) return;

}

LogicalResult Conv2DOp::verify() { return Verify(*this); }
LogicalResult Conv3DOp::verify() { return Verify(*this); }

LogicalResult Conv2DOp::UpdateDataFormat(StringRef data_format) {
  auto perm = GetDataFormatPermutation(this->getDataFormat(), data_format);
  if (perm.empty()) return failure();

  // Update data_format attribute and result types.
  if (failed(::mlir::TF::UpdateDataFormat(data_format, this))) return failure();