return;
    }
  }

  // Dimension equals to -1 means per-channel quantization is not supported for
  // the op. Therefore check whether the return value is positive integer as
  // well.
  static const LazyRE2 per_channel_support_regex = {
      "int GetQuantizationDimIndex\\(\\) \\{ return (\\d*); \\}"};

  for (const auto *def : defs) {
    Operator op(def);