pass.h revision 4e97c539408f47145526f0062c1c06df99146a73 
1/*
2 * Copyright (C) 2014 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_DEX_PASS_H_
18#define ART_COMPILER_DEX_PASS_H_
19
20#include <string>
21
22namespace art {
23
24// Forward declarations.
25class BasicBlock;
26class CompilationUnit;
27class Pass;
28
29/**
30 * @brief OptimizationFlag is an enumeration to perform certain tasks for a given pass.
31 * @details Each enum should be a power of 2 to be correctly used.
32 */
33enum OptimizationFlag {
34};
35
36enum DataFlowAnalysisMode {
37  kAllNodes = 0,                           /**< @brief All nodes. */
38  kPreOrderDFSTraversal,                   /**< @brief Depth-First-Search / Pre-Order. */
39  kRepeatingPreOrderDFSTraversal,          /**< @brief Depth-First-Search / Repeating Pre-Order. */
40  kReversePostOrderDFSTraversal,           /**< @brief Depth-First-Search / Reverse Post-Order. */
41  kRepeatingPostOrderDFSTraversal,         /**< @brief Depth-First-Search / Repeating Post-Order. */
42  kRepeatingReversePostOrderDFSTraversal,  /**< @brief Depth-First-Search / Repeating Reverse Post-Order. */
43  kPostOrderDOMTraversal,                  /**< @brief Dominator tree / Post-Order. */
44};
45
46/**
47 * @class Pass
48 * @brief Pass is the Pass structure for the optimizations.
49 * @details The following structure has the different optimization passes that we are going to do.
50 */
51class Pass {
52 public:
53  Pass(const char *name, DataFlowAnalysisMode type, bool freed, const unsigned int f, const char *dump): pass_name_(name), traversal_type_(type), flags_(f), dump_cfg_folder_(dump) {
54  }
55
56  Pass(const char *name, const char *dump): pass_name_(name), traversal_type_(kAllNodes), flags_(0), dump_cfg_folder_(dump) {
57  }
58
59  explicit Pass(const char *name):pass_name_(name), traversal_type_(kAllNodes), flags_(0), dump_cfg_folder_("") {
60  }
61
62  Pass(const char *name, DataFlowAnalysisMode type, const char *dump):pass_name_(name), traversal_type_(type), flags_(false), dump_cfg_folder_(dump) {
63  }
64
65  virtual ~Pass() {}
66
67  virtual const char* GetName() const {
68    return pass_name_;
69  }
70
71  virtual DataFlowAnalysisMode GetTraversal() const {
72    return traversal_type_;
73  }
74
75  virtual bool GetFlag(OptimizationFlag flag) const {
76    return (flags_ & flag);
77  }
78
79  const char* GetDumpCFGFolder() const {return dump_cfg_folder_;}
80
81  /**
82   * @brief Gate for the pass: determines whether to execute the pass or not considering a CompilationUnit
83   * @param c_unit the CompilationUnit.
84   * @return whether or not to execute the pass
85   */
86  virtual bool Gate(const CompilationUnit *c_unit) const {
87    // Unused parameter.
88    UNUSED(c_unit);
89
90    // Base class says yes.
91    return true;
92  }
93
94  /**
95   * @brief Start of the pass: called before the WalkBasicBlocks function
96   * @param c_unit the considered CompilationUnit.
97   */
98  virtual void Start(CompilationUnit *c_unit) const {
99    // Unused parameter.
100    UNUSED(c_unit);
101  }
102
103  /**
104   * @brief End of the pass: called after the WalkBasicBlocks function
105   * @param c_unit the considered CompilationUnit.
106   */
107  virtual void End(CompilationUnit *c_unit) const {
108    // Unused parameter.
109    UNUSED(c_unit);
110  }
111
112  /**
113   * @brief Actually walk the BasicBlocks following a particular traversal type.
114   * @param c_unit the CompilationUnit.
115   * @param bb the BasicBlock.
116   * @return whether or not there is a change when walking the BasicBlock
117   */
118  virtual bool WalkBasicBlocks(CompilationUnit *c_unit, BasicBlock *bb) const {
119    // Unused parameters.
120    UNUSED(c_unit);
121    UNUSED(bb);
122
123    // BasicBlock did not change.
124    return false;
125  }
126
127 protected:
128  /** @brief The pass name: used for searching for a pass when running a particular pass or debugging. */
129  const char* const pass_name_;
130
131  /** @brief Type of traversal: determines the order to execute the pass on the BasicBlocks. */
132  const DataFlowAnalysisMode traversal_type_;
133
134  /** @brief Flags for additional directives: used to determine if a particular clean-up is necessary post pass. */
135  const unsigned int flags_;
136
137  /** @brief CFG Dump Folder: what sub-folder to use for dumping the CFGs post pass. */
138  const char* const dump_cfg_folder_;
139
140 private:
141  // In order to make the all passes not copy-friendly.
142  DISALLOW_COPY_AND_ASSIGN(Pass);
143};
144}  // namespace art
145#endif  // ART_COMPILER_DEX_PASS_H_
146