Line data    Source code

       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             : #include "src/globals.h"
      10             : 
      11             : namespace v8 {
      12             : namespace internal {
      13             : namespace compiler {
      14             : 
      15             : // Forward declarations.
      16             : class Graph;
      17             : 
      18             : // Trims dead nodes from the node graph.
      19     9576908 : class V8_EXPORT_PRIVATE 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     4787149 :   void TrimGraph(ForwardIterator begin, ForwardIterator end) {
      31    81760274 :     while (begin != end) {
      32    76973116 :       Node* const node = *begin++;
      33    76973116 :       if (!node->IsDead()) MarkAsLive(node);
      34             :     }
      35     4787158 :     TrimGraph();
      36     4788447 :   }
      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   835562295 :     if (!IsLive(node)) {
      43             :       is_live_.Set(node, true);
      44   318892675 :       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_