1 //===- RegionPass.h - RegionPass class --------------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
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.
14 //===----------------------------------------------------------------------===//
16 #ifndef LLVM_ANALYSIS_REGIONPASS_H
17 #define LLVM_ANALYSIS_REGIONPASS_H
19 #include "llvm/Analysis/RegionInfo.h"
20 #include "llvm/IR/Function.h"
21 #include "llvm/IR/LegacyPassManagers.h"
22 #include "llvm/Pass.h"
30 //===----------------------------------------------------------------------===//
31 /// @brief A pass that runs on each Region in a function.
33 /// RegionPass is managed by RGPassManager.
34 class RegionPass : public Pass {
36 explicit RegionPass(char &pid) : Pass(PT_Region, pid) {}
38 //===--------------------------------------------------------------------===//
39 /// @name To be implemented by every RegionPass
42 /// @brief Run the pass on a specific Region
44 /// Accessing regions not contained in the current region is not allowed.
46 /// @param R The region this pass is run on.
47 /// @param RGM The RegionPassManager that manages this Pass.
49 /// @return True if the pass modifies this Region.
50 virtual bool runOnRegion(Region *R, RGPassManager &RGM) = 0;
52 /// @brief Get a pass to print the LLVM IR in the region.
54 /// @param O The output stream to print the Region.
55 /// @param Banner The banner to separate different printed passes.
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;
61 using llvm::Pass::doInitialization;
62 using llvm::Pass::doFinalization;
64 virtual bool doInitialization(Region *R, RGPassManager &RGM) { return false; }
65 virtual bool doFinalization() { return false; }
68 //===--------------------------------------------------------------------===//
69 /// @name PassManager API
72 void preparePassManager(PMStack &PMS) override;
74 void assignPassManager(PMStack &PMS,
75 PassManagerType PMT = PMT_RegionPassManager) override;
77 PassManagerType getPotentialPassManagerType() const override {
78 return PMT_RegionPassManager;
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;
88 /// @brief The pass manager to schedule RegionPasses.
89 class RGPassManager : public FunctionPass, public PMDataManager {
90 std::deque<Region*> RQ;
94 Region *CurrentRegion;
98 explicit RGPassManager();
100 /// @brief Execute all of the passes scheduled for execution.
102 /// @return True if any of the passes modifies the function.
103 bool runOnFunction(Function &F) override;
105 /// Pass Manager itself does not invalidate any analysis info.
106 /// RGPassManager needs RegionInfo.
107 void getAnalysisUsage(AnalysisUsage &Info) const override;
109 StringRef getPassName() const override { return "Region Pass Manager"; }
111 PMDataManager *getAsPMDataManager() override { return this; }
112 Pass *getAsPass() override { return this; }
114 /// @brief Print passes managed by this manager.
115 void dumpPassStructure(unsigned Offset) override;
117 /// @brief 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]);
124 PassManagerType getPassManagerType() const override {
125 return PMT_RegionPassManager;
129 } // End llvm namespace