1 //===- LoopPass.h - LoopPass class ----------------------------------------===// 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 LoopPass class. All loop optimization 11 // and transformation passes are derived from LoopPass. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #ifndef LLVM_ANALYSIS_LOOPPASS_H 16 #define LLVM_ANALYSIS_LOOPPASS_H 17 18 #include "llvm/Analysis/LoopInfo.h" 19 #include "llvm/Pass.h" 20 #include "llvm/PassManagers.h" 21 #include <deque> 22 23 namespace llvm { 24 25 class LPPassManager; 26 class Function; 27 class PMStack; 28 29 class LoopPass : public Pass { 30 public: 31 explicit LoopPass(char &pid) : Pass(PT_Loop, pid) {} 32 33 /// getPrinterPass - Get a pass to print the function corresponding 34 /// to a Loop. 35 Pass *createPrinterPass(raw_ostream &O, const std::string &Banner) const; 36 37 // runOnLoop - This method should be implemented by the subclass to perform 38 // whatever action is necessary for the specified Loop. 39 virtual bool runOnLoop(Loop *L, LPPassManager &LPM) = 0; 40 41 using llvm::Pass::doInitialization; 42 using llvm::Pass::doFinalization; 43 44 // Initialization and finalization hooks. 45 virtual bool doInitialization(Loop *L, LPPassManager &LPM) { 46 return false; 47 } 48 49 // Finalization hook does not supply Loop because at this time 50 // loop nest is completely different. 51 virtual bool doFinalization() { return false; } 52 53 // Check if this pass is suitable for the current LPPassManager, if 54 // available. This pass P is not suitable for a LPPassManager if P 55 // is not preserving higher level analysis info used by other 56 // LPPassManager passes. In such case, pop LPPassManager from the 57 // stack. This will force assignPassManager() to create new 58 // LPPassManger as expected. 59 void preparePassManager(PMStack &PMS); 60 61 /// Assign pass manager to manage this pass 62 virtual void assignPassManager(PMStack &PMS, 63 PassManagerType PMT); 64 65 /// Return what kind of Pass Manager can manage this pass. 66 virtual PassManagerType getPotentialPassManagerType() const { 67 return PMT_LoopPassManager; 68 } 69 70 //===--------------------------------------------------------------------===// 71 /// SimpleAnalysis - Provides simple interface to update analysis info 72 /// maintained by various passes. Note, if required this interface can 73 /// be extracted into a separate abstract class but it would require 74 /// additional use of multiple inheritance in Pass class hierarchy, something 75 /// we are trying to avoid. 76 77 /// Each loop pass can override these simple analysis hooks to update 78 /// desired analysis information. 79 /// cloneBasicBlockAnalysis - Clone analysis info associated with basic block. 80 virtual void cloneBasicBlockAnalysis(BasicBlock *F, BasicBlock *T, Loop *L) {} 81 82 /// deleteAnalysisValue - Delete analysis info associated with value V. 83 virtual void deleteAnalysisValue(Value *V, Loop *L) {} 84 }; 85 86 class LPPassManager : public FunctionPass, public PMDataManager { 87 public: 88 static char ID; 89 explicit LPPassManager(); 90 91 /// run - Execute all of the passes scheduled for execution. Keep track of 92 /// whether any of the passes modifies the module, and if so, return true. 93 bool runOnFunction(Function &F); 94 95 /// Pass Manager itself does not invalidate any analysis info. 96 // LPPassManager needs LoopInfo. 97 void getAnalysisUsage(AnalysisUsage &Info) const; 98 99 virtual const char *getPassName() const { 100 return "Loop Pass Manager"; 101 } 102 103 virtual PMDataManager *getAsPMDataManager() { return this; } 104 virtual Pass *getAsPass() { return this; } 105 106 /// Print passes managed by this manager 107 void dumpPassStructure(unsigned Offset); 108 109 LoopPass *getContainedPass(unsigned N) { 110 assert(N < PassVector.size() && "Pass number out of range!"); 111 LoopPass *LP = static_cast<LoopPass *>(PassVector[N]); 112 return LP; 113 } 114 115 virtual PassManagerType getPassManagerType() const { 116 return PMT_LoopPassManager; 117 } 118 119 public: 120 // Delete loop from the loop queue and loop nest (LoopInfo). 121 void deleteLoopFromQueue(Loop *L); 122 123 // Insert loop into the loop queue and add it as a child of the 124 // given parent. 125 void insertLoop(Loop *L, Loop *ParentLoop); 126 127 // Insert a loop into the loop queue. 128 void insertLoopIntoQueue(Loop *L); 129 130 // Reoptimize this loop. LPPassManager will re-insert this loop into the 131 // queue. This allows LoopPass to change loop nest for the loop. This 132 // utility may send LPPassManager into infinite loops so use caution. 133 void redoLoop(Loop *L); 134 135 //===--------------------------------------------------------------------===// 136 /// SimpleAnalysis - Provides simple interface to update analysis info 137 /// maintained by various passes. Note, if required this interface can 138 /// be extracted into a separate abstract class but it would require 139 /// additional use of multiple inheritance in Pass class hierarchy, something 140 /// we are trying to avoid. 141 142 /// cloneBasicBlockSimpleAnalysis - Invoke cloneBasicBlockAnalysis hook for 143 /// all passes that implement simple analysis interface. 144 void cloneBasicBlockSimpleAnalysis(BasicBlock *From, BasicBlock *To, Loop *L); 145 146 /// deleteSimpleAnalysisValue - Invoke deleteAnalysisValue hook for all passes 147 /// that implement simple analysis interface. 148 void deleteSimpleAnalysisValue(Value *V, Loop *L); 149 150 private: 151 std::deque<Loop *> LQ; 152 bool skipThisLoop; 153 bool redoThisLoop; 154 LoopInfo *LI; 155 Loop *CurrentLoop; 156 }; 157 158 } // End llvm namespace 159 160 #endif 161