1// Copyright 2013 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_HYDROGEN_ESCAPE_ANALYSIS_H_
6#define V8_HYDROGEN_ESCAPE_ANALYSIS_H_
7
8#include "src/allocation.h"
9#include "src/hydrogen.h"
10
11namespace v8 {
12namespace internal {
13
14
15class HEscapeAnalysisPhase : public HPhase {
16 public:
17  explicit HEscapeAnalysisPhase(HGraph* graph)
18      : HPhase("H_Escape analysis", graph),
19        captured_(0, zone()),
20        number_of_objects_(0),
21        number_of_values_(0),
22        cumulative_values_(0),
23        block_states_(graph->blocks()->length(), zone()) { }
24
25  void Run();
26
27 private:
28  void CollectCapturedValues();
29  bool HasNoEscapingUses(HValue* value, int size);
30  void PerformScalarReplacement();
31  void AnalyzeDataFlow(HInstruction* instr);
32
33  HCapturedObject* NewState(HInstruction* prev);
34  HCapturedObject* NewStateForAllocation(HInstruction* prev);
35  HCapturedObject* NewStateForLoopHeader(HInstruction* prev, HCapturedObject*);
36  HCapturedObject* NewStateCopy(HInstruction* prev, HCapturedObject* state);
37
38  HPhi* NewPhiAndInsert(HBasicBlock* block, HValue* incoming_value, int index);
39
40  HValue* NewMapCheckAndInsert(HCapturedObject* state, HCheckMaps* mapcheck);
41
42  HValue* NewLoadReplacement(HLoadNamedField* load, HValue* load_value);
43
44  HCapturedObject* StateAt(HBasicBlock* block) {
45    return block_states_.at(block->block_id());
46  }
47
48  void SetStateAt(HBasicBlock* block, HCapturedObject* state) {
49    block_states_.Set(block->block_id(), state);
50  }
51
52  // List of allocations captured during collection phase.
53  ZoneList<HInstruction*> captured_;
54
55  // Number of captured objects on which scalar replacement was done.
56  int number_of_objects_;
57
58  // Number of scalar values tracked during scalar replacement phase.
59  int number_of_values_;
60  int cumulative_values_;
61
62  // Map of block IDs to the data-flow state at block entry during the
63  // scalar replacement phase.
64  ZoneList<HCapturedObject*> block_states_;
65};
66
67
68} }  // namespace v8::internal
69
70#endif  // V8_HYDROGEN_ESCAPE_ANALYSIS_H_
71