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