66 lines
2.2 KiB
C++
66 lines
2.2 KiB
C++
/* Copyright 2017 The TensorFlow Authors. All Rights Reserved.
|
|
|
|
Licensed under the Apache License, Version 2.0 (the "License");
|
|
you may not use this file except in compliance with the License.
|
|
You may obtain a copy of the License at
|
|
|
|
http://www.apache.org/licenses/LICENSE-2.0
|
|
|
|
Unless required by applicable law or agreed to in writing, software
|
|
distributed under the License is distributed on an "AS IS" BASIS,
|
|
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
See the License for the specific language governing permissions and
|
|
limitations under the License.
|
|
==============================================================================*/
|
|
|
|
#ifndef TENSORFLOW_COMPILER_JIT_SHAPE_INFERENCE_HELPERS_H_
|
|
#define TENSORFLOW_COMPILER_JIT_SHAPE_INFERENCE_HELPERS_H_
|
|
|
|
#include <vector>
|
|
|
|
#include "tensorflow/core/graph/graph.h"
|
|
|
|
namespace tensorflow {
|
|
|
|
// Helper class to temporarily remove, then replace, the back edges in a
|
|
// graph. Simple algorithms for shape inference don't work with cycles, and this
|
|
// class can be used to remove cycles before running inference and replace them
|
|
// after. Correct usage requires exactly one call to Remove(), followed by any
|
|
// number of calls to RemovedEdges() and at most one call to Replace(). The call
|
|
// to Replace() is optional if the graph will be discarded without being
|
|
// executed, e.g., if it is being used purely for a shape inference pass.
|
|
class BackEdgeHelper {
|
|
public:
|
|
struct BackEdge {
|
|
const Edge* edge;
|
|
Node* src;
|
|
int src_output;
|
|
Node* dst;
|
|
int dst_input;
|
|
};
|
|
|
|
BackEdgeHelper() = default;
|
|
// Disallows copy and assign.
|
|
BackEdgeHelper(const BackEdgeHelper& other) = delete;
|
|
BackEdgeHelper& operator=(const BackEdgeHelper& other) = delete;
|
|
|
|
// Temporarily removes all the back edges in graph.
|
|
Status Remove(Graph* graph);
|
|
|
|
// Gets the list of removed edges.
|
|
const std::vector<BackEdge>& RemovedEdges() const;
|
|
|
|
// Replaces the back edges removed by a prior call to Remove.
|
|
Status Replace();
|
|
|
|
private:
|
|
Graph* graph_ = nullptr; // not owned
|
|
std::vector<BackEdge> back_edges_;
|
|
// Set once Replace has been called.
|
|
bool replaced_ = false;
|
|
};
|
|
|
|
} // namespace tensorflow
|
|
|
|
#endif // TENSORFLOW_COMPILER_JIT_SHAPE_INFERENCE_HELPERS_H_
|