Method ConstructHistogram

src/io/dense_bin.hpp:71–103

  BinIterator* GetIterator(uint32_t min_bin, uint32_t max_bin, uint32_t default_bin) const override;

  void ConstructHistogram(const data_size_t* data_indices, data_size_t num_data,
                          const score_t* ordered_gradients, const score_t* ordered_hessians,
                          HistogramBinEntry* out) const override {
    const data_size_t rest = num_data & 0x3;
    data_size_t i = 0;
    for (; i < num_data - rest; i += 4) {
      const VAL_T bin0 = data_[data_indices[i]];
      const VAL_T bin1 = data_[data_indices[i + 1]];
      const VAL_T bin2 = data_[data_indices[i + 2]];
      const VAL_T bin3 = data_[data_indices[i + 3]];

      out[bin0].sum_gradients += ordered_gradients[i];
      out[bin1].sum_gradients += ordered_gradients[i + 1];
      out[bin2].sum_gradients += ordered_gradients[i + 2];
      out[bin3].sum_gradients += ordered_gradients[i + 3];

      out[bin0].sum_hessians += ordered_hessians[i];
      out[bin1].sum_hessians += ordered_hessians[i + 1];
      out[bin2].sum_hessians += ordered_hessians[i + 2];
      out[bin3].sum_hessians += ordered_hessians[i + 3];

      ++out[bin0].cnt;
      ++out[bin1].cnt;
      ++out[bin2].cnt;
      ++out[bin3].cnt;
    }
    for (; i < num_data; ++i) {
      const VAL_T bin = data_[data_indices[i]];
      out[bin].sum_gradients += ordered_gradients[i];
      out[bin].sum_hessians += ordered_hessians[i];
      ++out[bin].cnt;
    }
  }

  void ConstructHistogram(data_size_t num_data,
                          const score_t* ordered_gradients, const score_t* ordered_hessians,