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Define multi expand entry. (#8895)

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This commit is contained in:
Jiaming Yuan
2023-03-13 19:31:05 +08:00
committed by GitHub
parent bbee355b45
commit 5ba3509dd3
7 changed files with 125 additions and 60 deletions
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121
src/tree/hist/expand_entry.h
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@@ -1,29 +1,51 @@
/*!
* Copyright 2021 XGBoost contributors
/**
* Copyright 2021-2023 XGBoost contributors
*/
#ifndef XGBOOST_TREE_HIST_EXPAND_ENTRY_H_
#define XGBOOST_TREE_HIST_EXPAND_ENTRY_H_
#include <utility>
#include "../param.h"
#include <algorithm> // for all_of
#include <ostream> // for ostream
#include <utility> // for move
#include <vector> // for vector
namespace xgboost {
namespace tree {
#include "../param.h" // for SplitEntry, SplitEntryContainer, TrainParam
#include "xgboost/base.h" // for GradientPairPrecise, bst_node_t
struct CPUExpandEntry {
int nid;
int depth;
SplitEntry split;
CPUExpandEntry() = default;
XGBOOST_DEVICE
CPUExpandEntry(int nid, int depth, SplitEntry split)
: nid(nid), depth(depth), split(std::move(split)) {}
CPUExpandEntry(int nid, int depth, float loss_chg)
: nid(nid), depth(depth) {
split.loss_chg = loss_chg;
namespace xgboost::tree {
/**
* \brief Structure for storing tree split candidate.
*/
template <typename Impl>
struct ExpandEntryImpl {
bst_node_t nid;
bst_node_t depth;
[[nodiscard]] float GetLossChange() const {
return static_cast<Impl const*>(this)->split.loss_chg;
}
[[nodiscard]] bst_node_t GetNodeId() const { return nid; }
static bool ChildIsValid(TrainParam const& param, bst_node_t depth, bst_node_t num_leaves) {
if (param.max_depth > 0 && depth >= param.max_depth) return false;
if (param.max_leaves > 0 && num_leaves >= param.max_leaves) return false;
return true;
}
bool IsValid(const TrainParam& param, int num_leaves) const {
[[nodiscard]] bool IsValid(TrainParam const& param, bst_node_t num_leaves) const {
return static_cast<Impl const*>(this)->IsValidImpl(param, num_leaves);
}
};
struct CPUExpandEntry : public ExpandEntryImpl<CPUExpandEntry> {
SplitEntry split;
CPUExpandEntry() = default;
CPUExpandEntry(bst_node_t nidx, bst_node_t depth, SplitEntry split)
: ExpandEntryImpl{nidx, depth}, split(std::move(split)) {}
CPUExpandEntry(bst_node_t nidx, bst_node_t depth) : ExpandEntryImpl{nidx, depth} {}
[[nodiscard]] bool IsValidImpl(TrainParam const& param, bst_node_t num_leaves) const {
if (split.loss_chg <= kRtEps) return false;
if (split.left_sum.GetHess() == 0 || split.right_sum.GetHess() == 0) {
return false;
@@ -40,16 +62,7 @@ struct CPUExpandEntry {
return true;
}
float GetLossChange() const { return split.loss_chg; }
bst_node_t GetNodeId() const { return nid; }
static bool ChildIsValid(const TrainParam& param, int depth, int num_leaves) {
if (param.max_depth > 0 && depth >= param.max_depth) return false;
if (param.max_leaves > 0 && num_leaves >= param.max_leaves) return false;
return true;
}
friend std::ostream& operator<<(std::ostream& os, const CPUExpandEntry& e) {
friend std::ostream& operator<<(std::ostream& os, CPUExpandEntry const& e) {
os << "ExpandEntry:\n";
os << "nidx: " << e.nid << "\n";
os << "depth: " << e.depth << "\n";
@@ -58,6 +71,54 @@ struct CPUExpandEntry {
return os;
}
};
} // namespace tree
} // namespace xgboost
struct MultiExpandEntry : public ExpandEntryImpl<MultiExpandEntry> {
SplitEntryContainer<std::vector<GradientPairPrecise>> split;
MultiExpandEntry() = default;
MultiExpandEntry(bst_node_t nidx, bst_node_t depth) : ExpandEntryImpl{nidx, depth} {}
[[nodiscard]] bool IsValidImpl(TrainParam const& param, bst_node_t num_leaves) const {
if (split.loss_chg <= kRtEps) return false;
auto is_zero = [](auto const& sum) {
return std::all_of(sum.cbegin(), sum.cend(),
[&](auto const& g) { return g.GetHess() - .0 == .0; });
};
if (is_zero(split.left_sum) || is_zero(split.right_sum)) {
return false;
}
if (split.loss_chg < param.min_split_loss) {
return false;
}
if (param.max_depth > 0 && depth == param.max_depth) {
return false;
}
if (param.max_leaves > 0 && num_leaves == param.max_leaves) {
return false;
}
return true;
}
friend std::ostream& operator<<(std::ostream& os, MultiExpandEntry const& e) {
os << "ExpandEntry: \n";
os << "nidx: " << e.nid << "\n";
os << "depth: " << e.depth << "\n";
os << "loss: " << e.split.loss_chg << "\n";
os << "split cond:" << e.split.split_value << "\n";
os << "split ind:" << e.split.SplitIndex() << "\n";
os << "left_sum: [";
for (auto v : e.split.left_sum) {
os << v << ", ";
}
os << "]\n";
os << "right_sum: [";
for (auto v : e.split.right_sum) {
os << v << ", ";
}
os << "]\n";
return os;
}
};
} // namespace xgboost::tree
#endif // XGBOOST_TREE_HIST_EXPAND_ENTRY_H_

4
src/tree/updater_approx.cc
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@@ -226,8 +226,8 @@ class GloablApproxBuilder {
for (auto const &candidate : valid_candidates) {
int left_child_nidx = tree[candidate.nid].LeftChild();
int right_child_nidx = tree[candidate.nid].RightChild();
CPUExpandEntry l_best{left_child_nidx, tree.GetDepth(left_child_nidx), {}};
CPUExpandEntry r_best{right_child_nidx, tree.GetDepth(right_child_nidx), {}};
CPUExpandEntry l_best{left_child_nidx, tree.GetDepth(left_child_nidx)};
CPUExpandEntry r_best{right_child_nidx, tree.GetDepth(right_child_nidx)};
best_splits.push_back(l_best);
best_splits.push_back(r_best);
}

6
src/tree/updater_quantile_hist.cc
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@@ -57,7 +57,7 @@ bool QuantileHistMaker::UpdatePredictionCache(const DMatrix *data,
CPUExpandEntry QuantileHistMaker::Builder::InitRoot(
DMatrix *p_fmat, RegTree *p_tree, const std::vector<GradientPair> &gpair_h) {
CPUExpandEntry node(RegTree::kRoot, p_tree->GetDepth(0), 0.0f);
CPUExpandEntry node(RegTree::kRoot, p_tree->GetDepth(0));
size_t page_id = 0;
auto space = ConstructHistSpace(partitioner_, {node});
@@ -197,8 +197,8 @@ void QuantileHistMaker::Builder::ExpandTree(DMatrix *p_fmat, RegTree *p_tree,
for (auto const &candidate : valid_candidates) {
int left_child_nidx = tree[candidate.nid].LeftChild();
int right_child_nidx = tree[candidate.nid].RightChild();
CPUExpandEntry l_best{left_child_nidx, depth, 0.0};
CPUExpandEntry r_best{right_child_nidx, depth, 0.0};
CPUExpandEntry l_best{left_child_nidx, depth};
CPUExpandEntry r_best{right_child_nidx, depth};
best_splits.push_back(l_best);
best_splits.push_back(r_best);
}