Method ReduceScaleBy

cpp/src/arrow/util/basic_decimal.cc:121–141

}

BasicDecimal32 BasicDecimal32::ReduceScaleBy(int32_t reduce_by, bool round) const {
  DCHECK_GE(reduce_by, 0);
  DCHECK_LE(reduce_by, kMaxScale);

  if (reduce_by == 0) {
    return *this;
  }

  BasicDecimal32 divisor(DecimalTraits<BasicDecimal32>::powers_of_ten()[reduce_by]);
  BasicDecimal32 result;
  BasicDecimal32 remainder;
  auto s = Divide(divisor, &result, &remainder);
  DCHECK_EQ(s, DecimalStatus::kSuccess);
  if (round) {
    auto divisor_half = DecimalTraits<BasicDecimal32>::half_powers_of_ten()[reduce_by];
    if (remainder.Abs() >= divisor_half) {
      result += Sign();
    }
  }
  return result;
}

const BasicDecimal32& BasicDecimal32::GetScaleMultiplier(int32_t scale) {
  DCHECK_GE(scale, 0);