RegionPass.h revision 341825 
1//===- RegionPass.h - RegionPass class --------------------------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file defines the RegionPass class. All region based analysis,
11// optimization and transformation passes are derived from RegionPass.
12// This class is implemented following the some ideas of the LoopPass.h class.
13//
14//===----------------------------------------------------------------------===//
15
16#ifndef LLVM_ANALYSIS_REGIONPASS_H
17#define LLVM_ANALYSIS_REGIONPASS_H
18
19#include "llvm/Analysis/RegionInfo.h"
20#include "llvm/IR/Function.h"
21#include "llvm/IR/LegacyPassManagers.h"
22#include "llvm/Pass.h"
23#include <deque>
24
25namespace llvm {
26
27class RGPassManager;
28class Function;
29
30//===----------------------------------------------------------------------===//
31/// A pass that runs on each Region in a function.
32///
33/// RegionPass is managed by RGPassManager.
34class RegionPass : public Pass {
35public:
36  explicit RegionPass(char &pid) : Pass(PT_Region, pid) {}
37
38  //===--------------------------------------------------------------------===//
39  /// @name To be implemented by every RegionPass
40  ///
41  //@{
42  /// Run the pass on a specific Region
43  ///
44  /// Accessing regions not contained in the current region is not allowed.
45  ///
46  /// @param R The region this pass is run on.
47  /// @param RGM The RegionPassManager that manages this Pass.
48  ///
49  /// @return True if the pass modifies this Region.
50  virtual bool runOnRegion(Region *R, RGPassManager &RGM) = 0;
51
52  /// Get a pass to print the LLVM IR in the region.
53  ///
54  /// @param O      The output stream to print the Region.
55  /// @param Banner The banner to separate different printed passes.
56  ///
57  /// @return The pass to print the LLVM IR in the region.
58  Pass *createPrinterPass(raw_ostream &O,
59                          const std::string &Banner) const override;
60
61  using llvm::Pass::doInitialization;
62  using llvm::Pass::doFinalization;
63
64  virtual bool doInitialization(Region *R, RGPassManager &RGM) { return false; }
65  virtual bool doFinalization() { return false; }
66  //@}
67
68  //===--------------------------------------------------------------------===//
69  /// @name PassManager API
70  ///
71  //@{
72  void preparePassManager(PMStack &PMS) override;
73
74  void assignPassManager(PMStack &PMS,
75                         PassManagerType PMT = PMT_RegionPassManager) override;
76
77  PassManagerType getPotentialPassManagerType() const override {
78    return PMT_RegionPassManager;
79  }
80  //@}
81
82protected:
83  /// Optional passes call this function to check whether the pass should be
84  /// skipped. This is the case when optimization bisect is over the limit.
85  bool skipRegion(Region &R) const;
86};
87
88/// The pass manager to schedule RegionPasses.
89class RGPassManager : public FunctionPass, public PMDataManager {
90  std::deque<Region*> RQ;
91  bool skipThisRegion;
92  bool redoThisRegion;
93  RegionInfo *RI;
94  Region *CurrentRegion;
95
96public:
97  static char ID;
98  explicit RGPassManager();
99
100  /// Execute all of the passes scheduled for execution.
101  ///
102  /// @return True if any of the passes modifies the function.
103  bool runOnFunction(Function &F) override;
104
105  /// Pass Manager itself does not invalidate any analysis info.
106  /// RGPassManager needs RegionInfo.
107  void getAnalysisUsage(AnalysisUsage &Info) const override;
108
109  StringRef getPassName() const override { return "Region Pass Manager"; }
110
111  PMDataManager *getAsPMDataManager() override { return this; }
112  Pass *getAsPass() override { return this; }
113
114  /// Print passes managed by this manager.
115  void dumpPassStructure(unsigned Offset) override;
116
117  /// Get passes contained by this manager.
118  Pass *getContainedPass(unsigned N) {
119    assert(N < PassVector.size() && "Pass number out of range!");
120    Pass *FP = static_cast<Pass *>(PassVector[N]);
121    return FP;
122  }
123
124  PassManagerType getPassManagerType() const override {
125    return PMT_RegionPassManager;
126  }
127};
128
129} // End llvm namespace
130
131#endif
132