reference_type_propagation.h revision 27bb86edf60e2f9ca2c1075c0c86b9e79374f1d0 
1/*
2 * Copyright (C) 2015 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef ART_COMPILER_OPTIMIZING_REFERENCE_TYPE_PROPAGATION_H_
18#define ART_COMPILER_OPTIMIZING_REFERENCE_TYPE_PROPAGATION_H_
19
20#include "base/arena_containers.h"
21#include "driver/dex_compilation_unit.h"
22#include "handle_scope-inl.h"
23#include "nodes.h"
24#include "optimization.h"
25#include "optimizing_compiler_stats.h"
26
27namespace art {
28
29/**
30 * Propagates reference types to instructions.
31 */
32class ReferenceTypePropagation : public HOptimization {
33 public:
34  ReferenceTypePropagation(HGraph* graph,
35                           Handle<mirror::DexCache> hint_dex_cache,
36                           StackHandleScopeCollection* handles,
37                           bool is_first_run,
38                           const char* name = kReferenceTypePropagationPassName);
39
40  // Visit a single instruction.
41  void Visit(HInstruction* instruction);
42
43  void Run() OVERRIDE;
44
45  static constexpr const char* kReferenceTypePropagationPassName = "reference_type_propagation";
46
47 private:
48  class HandleCache {
49   public:
50    explicit HandleCache(StackHandleScopeCollection* handles) : handles_(handles) { }
51
52    template <typename T>
53    MutableHandle<T> NewHandle(T* object) SHARED_REQUIRES(Locks::mutator_lock_) {
54      return handles_->NewHandle(object);
55    }
56
57    ReferenceTypeInfo::TypeHandle GetObjectClassHandle();
58    ReferenceTypeInfo::TypeHandle GetClassClassHandle();
59    ReferenceTypeInfo::TypeHandle GetStringClassHandle();
60    ReferenceTypeInfo::TypeHandle GetThrowableClassHandle();
61
62   private:
63    StackHandleScopeCollection* handles_;
64
65    ReferenceTypeInfo::TypeHandle object_class_handle_;
66    ReferenceTypeInfo::TypeHandle class_class_handle_;
67    ReferenceTypeInfo::TypeHandle string_class_handle_;
68    ReferenceTypeInfo::TypeHandle throwable_class_handle_;
69  };
70
71  class RTPVisitor;
72
73  void VisitPhi(HPhi* phi);
74  void VisitBasicBlock(HBasicBlock* block);
75  void UpdateBoundType(HBoundType* bound_type) SHARED_REQUIRES(Locks::mutator_lock_);
76  void UpdatePhi(HPhi* phi) SHARED_REQUIRES(Locks::mutator_lock_);
77  void BoundTypeForIfNotNull(HBasicBlock* block);
78  void BoundTypeForIfInstanceOf(HBasicBlock* block);
79  void ProcessWorklist();
80  void AddToWorklist(HInstruction* instr);
81  void AddDependentInstructionsToWorklist(HInstruction* instr);
82
83  bool UpdateNullability(HInstruction* instr);
84  bool UpdateReferenceTypeInfo(HInstruction* instr);
85
86  static void UpdateArrayGet(HArrayGet* instr, HandleCache* handle_cache)
87      SHARED_REQUIRES(Locks::mutator_lock_);
88
89  ReferenceTypeInfo MergeTypes(const ReferenceTypeInfo& a, const ReferenceTypeInfo& b)
90      SHARED_REQUIRES(Locks::mutator_lock_);
91
92  void ValidateTypes();
93
94  // Note: hint_dex_cache_ is usually, but not necessarily, the dex cache associated with
95  // graph_->GetDexFile(). Since we may look up also in other dex files, it's used only
96  // as a hint, to reduce the number of calls to the costly ClassLinker::FindDexCache().
97  Handle<mirror::DexCache> hint_dex_cache_;
98  HandleCache handle_cache_;
99
100  ArenaVector<HInstruction*> worklist_;
101
102  // Whether this reference type propagation is the first run we are doing.
103  const bool is_first_run_;
104
105  static constexpr size_t kDefaultWorklistSize = 8;
106
107  DISALLOW_COPY_AND_ASSIGN(ReferenceTypePropagation);
108};
109
110}  // namespace art
111
112#endif  // ART_COMPILER_OPTIMIZING_REFERENCE_TYPE_PROPAGATION_H_
113