1 | /* |
2 | * Licensed to the Apache Software Foundation (ASF) under one |
3 | * or more contributor license agreements. See the NOTICE file |
4 | * distributed with this work for additional information |
5 | * regarding copyright ownership. The ASF licenses this file |
6 | * to you under the Apache License, Version 2.0 (the |
7 | * "License"); you may not use this file except in compliance |
8 | * with the License. You may obtain a copy of the License at |
9 | * |
10 | * http://www.apache.org/licenses/LICENSE-2.0 |
11 | * |
12 | * Unless required by applicable law or agreed to in writing, |
13 | * software distributed under the License is distributed on an |
14 | * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
15 | * KIND, either express or implied. See the License for the |
16 | * specific language governing permissions and limitations |
17 | * under the License. |
18 | */ |
19 | |
20 | /*! |
21 | * \file src/relay/analysis/dependency_graph.h |
22 | * \brief create a dependency graph. |
23 | */ |
24 | #ifndef TVM_RELAY_ANALYSIS_DEPENDENCY_GRAPH_H_ |
25 | #define TVM_RELAY_ANALYSIS_DEPENDENCY_GRAPH_H_ |
26 | |
27 | #include <tvm/relay/expr.h> |
28 | |
29 | #include <unordered_map> |
30 | #include <vector> |
31 | |
32 | #include "../../support/arena.h" |
33 | #include "../transforms/let_list.h" |
34 | |
35 | namespace tvm { |
36 | namespace relay { |
37 | |
38 | using support::LinkedList; |
39 | using support::LinkNode; |
40 | |
41 | /* DependencyGraph track input and output of an Expr. |
42 | * Additionally, dummy scope is created to model scope. |
43 | * It allow us to traverse the graph in reverse order. |
44 | */ |
45 | class DependencyGraph { |
46 | public: |
47 | /*! \brief A node in the graph. */ |
48 | struct Node { |
49 | // Determine scope boundaries. Used for calculating scopes, not for |
50 | // constructing dependency graph. |
51 | bool new_scope = false; |
52 | // incoming edges |
53 | LinkedList<Node*> children; |
54 | // outgoing edges |
55 | LinkedList<Node*> parents; |
56 | }; |
57 | |
58 | /*! \brief Maps a Relay Expr to its node in the dependency graph. */ |
59 | std::unordered_map<Expr, Node*, ObjectPtrHash, ObjectPtrEqual> expr_node; |
60 | |
61 | /*! \brief The dependency graph in post DFS order. */ |
62 | std::vector<Node*> post_dfs_order; |
63 | |
64 | /*! |
65 | * \brief Create a dependency graph. |
66 | * \param arena The arena used for data allocation. |
67 | * \param body The body of the expression to create a graph. |
68 | */ |
69 | static DependencyGraph Create(support::Arena* arena, const Expr& body); |
70 | |
71 | private: |
72 | class Creator; |
73 | }; |
74 | |
75 | } // namespace relay |
76 | } // namespace tvm |
77 | #endif // TVM_RELAY_ANALYSIS_DEPENDENCY_GRAPH_H_ |
78 | |