[sycl] add partitioning and related tests (#10080)

Co-authored-by: Dmitry Razdoburdin <>

plugin/sycl/tree/expand_entry.h

@@ -0,0 +1,50 @@
+/*!
+ * Copyright 2017-2024 by Contributors
+ * \file expand_entry.h
+ */
+#ifndef PLUGIN_SYCL_TREE_EXPAND_ENTRY_H_
+#define PLUGIN_SYCL_TREE_EXPAND_ENTRY_H_
+
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wtautological-constant-compare"
+#include "../../src/tree/constraints.h"
+#pragma GCC diagnostic pop
+#include "../../src/tree/hist/expand_entry.h"
+
+namespace xgboost {
+namespace sycl {
+namespace tree {
+/* tree growing policies */
+struct ExpandEntry : public xgboost::tree::ExpandEntryImpl<ExpandEntry> {
+  static constexpr bst_node_t kRootNid  = 0;
+
+  xgboost::tree::SplitEntry split;
+
+  ExpandEntry(int nid, int depth) : ExpandEntryImpl{nid, depth} {}
+
+  inline bst_node_t GetSiblingId(const xgboost::RegTree* p_tree) const {
+    CHECK_EQ((*p_tree)[nid].IsRoot(), false);
+    const size_t parent_id = (*p_tree)[nid].Parent();
+    return GetSiblingId(p_tree, parent_id);
+  }
+
+  inline bst_node_t GetSiblingId(const xgboost::RegTree* p_tree, size_t parent_id) const {
+    return p_tree->IsLeftChild(nid) ? p_tree->RightChild(parent_id)
+                                    : p_tree->LeftChild(parent_id);
+  }
+
+  bool IsValidImpl(xgboost::tree::TrainParam const &param, int32_t num_leaves) const {
+    if (split.loss_chg <= kRtEps) 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;
+  }
+};
+
+}  // namespace tree
+}  // namespace sycl
+}  // namespace xgboost
+
+#endif  // PLUGIN_SYCL_TREE_EXPAND_ENTRY_H_