Function ExtendGraph

tensorflow/core/graph/graph_constructor.cc:1829–1870

} // namespace

void ExtendGraph(Graph* dest, std::unordered_set<const Node*> excluded,
    int32 duplicate_num) {
  // Copy the nodes "Node in src" -> "Node in *dest"
  map_node_list duplicated_nodes;
  map_node margin_nodes;
  for (Node* n : dest->op_nodes()) {
    if (excluded.find(n) != excluded.end()) {
      continue;
    }
    if (n->IsVariable() || n->IsConstant() || n->IsPlaceholder()) {
      margin_nodes.emplace(n, n);
    } else {
      duplicated_nodes.emplace(n, DuplicateNode(n, dest, duplicate_num));
    }
  }

  // Copy the edges
  auto edges = DuplicateEdges(dest, duplicated_nodes, margin_nodes);
  for (auto it : edges) {
    dest->AddEdge(it.src, it.src_output, it.dst, it.dst_input);
  }

  // Add aggregate nodes for Apply***
  for (Node* n : dest->op_nodes()) {
    if (n->IsApplyAdagradOps() || n->IsApplyFtrlOps()) {
      AggregateForApply(dest, n, duplicated_nodes, 3);
    }
    // concat ------------------------------->
    // concat(indices) --> unique(indices) --> unsorted_segment_sum
    if (n->IsSparseApplyAdagradOps() || n->IsSparseApplyFtrlOps()) {
      AggregateForSparseApply(dest, n, duplicated_nodes, 3, 4);
    }

    if (n->IsApplyAdamOps()) {
      AggregateForApply(dest, n, duplicated_nodes, 9);
    }

    if (n->IsApplySparseAdamOps()) {
      AggregateForSparseApply(dest, n, duplicated_nodes, 9, 10);
    }
  }
}

}  // namespace tensorflow