return success();
  }
  // Create the new while op.
  auto new_while_operands = llvm::to_vector<8>(while_op.getOperands());
  for (int64_t i = 0; i < while_op.getNumResults(); ++i) {
    auto it = buffer_to_size->find(while_op.getOperand(i));
    if (it == buffer_to_size->end()) continue;
    new_while_operands.push_back(it->getSecond().size);
  }
  auto new_while = builder.create<TF::WhileOp>(

  // Create the new while op.
  auto new_while_operands = llvm::to_vector<8>(while_op.getOperands());
  OpBuilder builder(while_op);
  assert(while_op.getNumOperands() == while_op.getNumResults());
  for (int64_t i = 0; i < while_op.getNumResults(); ++i) {
    auto it = data_var_to_size_var.find(while_op.getOperand(i));
    if (it == data_var_to_size_var.end()) continue;
    new_while_operands.push_back(it->getSecond());
  }

  SmallVector<Value, 4> new_while_operands;
  new_result_types.resize(num_extra_results);
  new_while_operands.resize(num_extra_results);

  for (auto& it : hoister.GetResources()) {
    if (!it.second.is_written) continue;
    int index = it.second.result_index - num_old_results;
    new_result_types[index] = it.second.data_type;
    new_while_operands[index] = it.second.hoisted_read;
  }

  llvm::SetVector<Value> new_while_operands;
  llvm::MapVector<Value, int> loop_var_map;
  for (auto operand : tmp_while_operands) {
    if (new_while_operands.insert(operand)) {
      // First time seeing this operand. Let's record the final resting place
      // in the new_while_operands vector.
      loop_var_map[operand] = new_while_operands.size() - 1;
    }
  }

    SmallVector<Value, 4> new_while_operands;
    SmallVector<Type, 4> new_result_types;
    new_while_operands.reserve(new_num_operands);
    new_result_types.reserve(new_num_operands);

    // Build new operands and result type.
    for (int op_idx : llvm::seq<int>(0, old_num_operands)) {
      if (removed_operand.test(op_idx)) continue;
      new_while_operands.push_back(while_op.getOperand(op_idx));