// Remove all empty values.
  SmallVector<Value, 4> non_empty_values;
  for (Value value : this->getValues()) {
    const auto shaped_type = value.getType().cast<ShapedType>();
    if (shaped_type.hasStaticShape() && shaped_type.getNumElements() == 0) {
      continue;
    }
    non_empty_values.push_back(value);
  }

  // All are not empty, do nothing.
  if (non_empty_values.size() == getNumOperands()) return nullptr;