1 | /** |
2 | * Copyright (c) Glow Contributors. See CONTRIBUTORS file. |
3 | * |
4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
5 | * you may not use this file except in compliance with the License. |
6 | * You may obtain a copy of the License at |
7 | * |
8 | * http://www.apache.org/licenses/LICENSE-2.0 |
9 | * |
10 | * Unless required by applicable law or agreed to in writing, software |
11 | * distributed under the License is distributed on an "AS IS" BASIS, |
12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
13 | * See the License for the specific language governing permissions and |
14 | * limitations under the License. |
15 | */ |
16 | #ifndef GLOW_GRAPH_GRAD_H |
17 | #define GLOW_GRAPH_GRAD_H |
18 | |
19 | #include "glow/Graph/Node.h" |
20 | |
21 | #include <unordered_map> |
22 | |
23 | namespace glow { |
24 | |
25 | class Function; |
26 | |
27 | /// A Helper class that manages the mapping between gradients and activations, |
28 | /// and helps to accumulate gradients into placeholders. |
29 | class GraphGradMapper { |
30 | /// The graph that we mutate. |
31 | Function *F_; |
32 | /// Maps activation values to their gradient values. |
33 | std::unordered_map<NodeValue, NodeValue> map_; |
34 | |
35 | public: |
36 | GraphGradMapper(Function *F) : F_(F) {} |
37 | |
38 | /// \register the node \p grad as the grad of \p activation. If the node is |
39 | /// already registered then create an 'add' node that accumulates the gradient |
40 | /// into the grad buffer. |
41 | void addGradient(NodeValue activation, NodeValue grad); |
42 | |
43 | /// \returns the node that \p activation is mapped to. |
44 | NodeValue getGradient(NodeValue activation); |
45 | |
46 | /// \returns True if the node \p activation is mapped. |
47 | bool hasGradient(NodeValue activation); |
48 | }; |
49 | |
50 | } // namespace glow |
51 | |
52 | #endif // GLOW_GRAPH_GRAD_H |
53 | |