Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1 | // Copyright 2015 the V8 project authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
| 5 | #ifndef V8_COMPILER_DEAD_CODE_ELIMINATION_H_ |
| 6 | #define V8_COMPILER_DEAD_CODE_ELIMINATION_H_ |
| 7 | |
| 8 | #include "src/compiler/graph-reducer.h" |
| 9 | |
| 10 | namespace v8 { |
| 11 | namespace internal { |
| 12 | namespace compiler { |
| 13 | |
| 14 | // Forward declarations. |
| 15 | class CommonOperatorBuilder; |
| 16 | |
| 17 | |
| 18 | // Propagates {Dead} control through the graph and thereby removes dead code. |
| 19 | // Note that this does not include trimming dead uses from the graph, and it |
| 20 | // also does not include detecting dead code by any other means than seeing a |
| 21 | // {Dead} control input; that is left to other reducers. |
| 22 | class DeadCodeElimination final : public AdvancedReducer { |
| 23 | public: |
| 24 | DeadCodeElimination(Editor* editor, Graph* graph, |
| 25 | CommonOperatorBuilder* common); |
| 26 | ~DeadCodeElimination() final {} |
| 27 | |
| 28 | Reduction Reduce(Node* node) final; |
| 29 | |
| 30 | private: |
| 31 | Reduction ReduceEnd(Node* node); |
| 32 | Reduction ReduceLoopOrMerge(Node* node); |
| 33 | Reduction ReduceNode(Node* node); |
| 34 | |
| 35 | void TrimMergeOrPhi(Node* node, int size); |
| 36 | |
| 37 | Graph* graph() const { return graph_; } |
| 38 | CommonOperatorBuilder* common() const { return common_; } |
| 39 | Node* dead() const { return dead_; } |
| 40 | |
| 41 | Graph* const graph_; |
| 42 | CommonOperatorBuilder* const common_; |
| 43 | Node* const dead_; |
| 44 | |
| 45 | DISALLOW_COPY_AND_ASSIGN(DeadCodeElimination); |
| 46 | }; |
| 47 | |
| 48 | } // namespace compiler |
| 49 | } // namespace internal |
| 50 | } // namespace v8 |
| 51 | |
| 52 | #endif // V8_COMPILER_DEAD_CODE_ELIMINATION_H_ |