Method Sum

cpp/src/arrow/acero/aggregate_benchmark.cc:251–292

  using ArrayType = typename CTypeTraits<T>::ArrayType;

  static void Sum(const ArrayType& array, SumState<T>* state) {
    SumState<T> local;

    const auto values = array.raw_values();
    const auto bitmap = array.null_bitmap_data();
    const auto length = array.length();
    const int64_t length_rounded = bit_util::RoundDown(length, 8);
    for (int64_t i = 0; i < length_rounded; i += 8) {
      const uint8_t valid_byte = bitmap[i / 8];

#  define SUM_SHIFT(ITEM) (values[i + ITEM] * ((valid_byte >> ITEM) & 1))

      if (valid_byte < 0xFF) {
        // Some nulls
        local.total += SUM_SHIFT(0);
        local.total += SUM_SHIFT(1);
        local.total += SUM_SHIFT(2);
        local.total += SUM_SHIFT(3);
        local.total += SUM_SHIFT(4);
        local.total += SUM_SHIFT(5);
        local.total += SUM_SHIFT(6);
        local.total += SUM_SHIFT(7);
        local.valid_count += std::popcount(valid_byte);
      } else {
        // No nulls
        local.total += values[i + 0] + values[i + 1] + values[i + 2] + values[i + 3] +
                       values[i + 4] + values[i + 5] + values[i + 6] + values[i + 7];
        local.valid_count += 8;
      }
    }

#  undef SUM_SHIFT

    for (int64_t i = length_rounded; i < length; ++i) {
      if (bit_util::GetBit(bitmap, i)) {
        local.total = values[i];
        ++local.valid_count;
      }
    }

    *state = local;
  }
};

template <typename Functor>