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_GRAPH_TRIMMER_H_ 6 #define V8_COMPILER_GRAPH_TRIMMER_H_ 7 8 #include "src/compiler/node-marker.h" 9 10 namespace v8 { 11 namespace internal { 12 namespace compiler { 13 14 // Forward declarations. 15 class Graph; 16 17 18 // Trims dead nodes from the node graph. 19 class GraphTrimmer final { 20 public: 21 GraphTrimmer(Zone* zone, Graph* graph); 22 ~GraphTrimmer(); 23 24 // Trim nodes in the {graph} that are not reachable from {graph->end()}. 25 void TrimGraph(); 26 27 // Trim nodes in the {graph} that are not reachable from either {graph->end()} 28 // or any of the roots in the sequence [{begin},{end}[. 29 template <typename ForwardIterator> 30 void TrimGraph(ForwardIterator begin, ForwardIterator end) { 31 while (begin != end) { 32 Node* const node = *begin++; 33 if (!node->IsDead()) MarkAsLive(node); 34 } 35 TrimGraph(); 36 } 37 38 private: 39 V8_INLINE bool IsLive(Node* const node) { return is_live_.Get(node); } 40 V8_INLINE void MarkAsLive(Node* const node) { 41 DCHECK(!node->IsDead()); 42 if (!IsLive(node)) { 43 is_live_.Set(node, true); 44 live_.push_back(node); 45 } 46 } 47 48 Graph* graph() const { return graph_; } 49 50 Graph* const graph_; 51 NodeMarker<bool> is_live_; 52 NodeVector live_; 53 54 DISALLOW_COPY_AND_ASSIGN(GraphTrimmer); 55 }; 56 57 } // namespace compiler 58 } // namespace internal 59 } // namespace v8 60 61 #endif // V8_COMPILER_GRAPH_TRIMMER_H_ 62
