auto spec = std::make_unique<OpQuantScaleSpec>();
  if (isa<SameScalesOpInterface>(op)) {
    spec->has_same_scale_requirement = true;
    spec->required_same_scale_func = [op](const bool sign,
                                          const int bit_width) {
      return cast<SameScalesOpInterface>(op)
          .RequiredSameOperandsAndResultsScale(sign, bit_width);
    };

                                    rewriter))) {
            return failure();
          }
        } else if (!llvm::isa<DQ>(input.getDefiningOp()) &&
                   !llvm::isa<SameScalesOpInterface, FixedOutputRangeInterface>(
                       input.getDefiningOp())) {
          // Continue if StatisticsOp is already converted to Q-DQ pair, or

    if (!pre_quantized_type) return failure();

    Operation* def = pre_quantized.getDefiningOp();
    if (!def) return failure();
    if (llvm::isa<FixedOutputRangeInterface, SameScalesOpInterface>(def) ||
        !def->hasTrait<OpTrait::quant::QuantizableResult>()) {
      return failure();
    }

    // This op should not clobber def, if more than one requant of this value.