LoopPass.h revision d8ac1be6862c0611cc0b3a726ad4c3141e7a3d9e
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 23namespace llvm { 24 25class LPPassManager; 26class Function; 27class PMStack; 28 29class LoopPass : public Pass { 30public: 31 explicit LoopPass(intptr_t pid) : Pass(pid) {} 32 explicit LoopPass(void *pid) : Pass(pid) {} 33 34 // runOnLoop - This method should be implemented by the subclass to perform 35 // whatever action is necessary for the specified Loop. 36 virtual bool runOnLoop(Loop *L, LPPassManager &LPM) = 0; 37 38 // Initialization and finalization hooks. 39 virtual bool doInitialization(Loop *L, LPPassManager &LPM) { 40 return false; 41 } 42 43 // Finalization hook does not supply Loop because at this time 44 // loop nest is completely different. 45 virtual bool doFinalization() { return false; } 46 47 // Check if this pass is suitable for the current LPPassManager, if 48 // available. This pass P is not suitable for a LPPassManager if P 49 // is not preserving higher level analysis info used by other 50 // LPPassManager passes. In such case, pop LPPassManager from the 51 // stack. This will force assignPassManager() to create new 52 // LPPassManger as expected. 53 void preparePassManager(PMStack &PMS); 54 55 /// Assign pass manager to manager this pass 56 virtual void assignPassManager(PMStack &PMS, 57 PassManagerType PMT = PMT_LoopPassManager); 58 59 /// Return what kind of Pass Manager can manage this pass. 60 virtual PassManagerType getPotentialPassManagerType() const { 61 return PMT_LoopPassManager; 62 } 63 64 //===--------------------------------------------------------------------===// 65 /// SimpleAnalysis - Provides simple interface to update analysis info 66 /// maintained by various passes. Note, if required this interface can 67 /// be extracted into a separate abstract class but it would require 68 /// additional use of multiple inheritance in Pass class hierarchy, something 69 /// we are trying to avoid. 70 71 /// Each loop pass can override these simple analysis hooks to update 72 /// desired analysis information. 73 /// cloneBasicBlockAnalysis - Clone analysis info associated with basic block. 74 virtual void cloneBasicBlockAnalysis(BasicBlock *F, BasicBlock *T, Loop *L) {} 75 76 /// deletekAnalysisValue - Delete analysis info associated with value V. 77 virtual void deleteAnalysisValue(Value *V, Loop *L) {} 78}; 79 80class LPPassManager : public FunctionPass, public PMDataManager { 81public: 82 static char ID; 83 explicit LPPassManager(int Depth); 84 85 /// run - Execute all of the passes scheduled for execution. Keep track of 86 /// whether any of the passes modifies the module, and if so, return true. 87 bool runOnFunction(Function &F); 88 89 /// Pass Manager itself does not invalidate any analysis info. 90 // LPPassManager needs LoopInfo. 91 void getAnalysisUsage(AnalysisUsage &Info) const; 92 93 virtual const char *getPassName() const { 94 return "Loop Pass Manager"; 95 } 96 97 /// Print passes managed by this manager 98 void dumpPassStructure(unsigned Offset); 99 100 Pass *getContainedPass(unsigned N) { 101 assert(N < PassVector.size() && "Pass number out of range!"); 102 Pass *FP = static_cast<Pass *>(PassVector[N]); 103 return FP; 104 } 105 106 virtual PassManagerType getPassManagerType() const { 107 return PMT_LoopPassManager; 108 } 109 110public: 111 // Delete loop from the loop queue and loop nest (LoopInfo). 112 void deleteLoopFromQueue(Loop *L); 113 114 // Insert loop into the loop nest(LoopInfo) and loop queue(LQ). 115 void insertLoop(Loop *L, Loop *ParentLoop); 116 117 // Reoptimize this loop. LPPassManager will re-insert this loop into the 118 // queue. This allows LoopPass to change loop nest for the loop. This 119 // utility may send LPPassManager into infinite loops so use caution. 120 void redoLoop(Loop *L); 121 122 //===--------------------------------------------------------------------===// 123 /// SimpleAnalysis - Provides simple interface to update analysis info 124 /// maintained by various passes. Note, if required this interface can 125 /// be extracted into a separate abstract class but it would require 126 /// additional use of multiple inheritance in Pass class hierarchy, something 127 /// we are trying to avoid. 128 129 /// cloneBasicBlockSimpleAnalysis - Invoke cloneBasicBlockAnalysis hook for 130 /// all passes that implement simple analysis interface. 131 void cloneBasicBlockSimpleAnalysis(BasicBlock *From, BasicBlock *To, Loop *L); 132 133 /// deleteSimpleAnalysisValue - Invoke deleteAnalysisValue hook for all passes 134 /// that implement simple analysis interface. 135 void deleteSimpleAnalysisValue(Value *V, Loop *L); 136 137private: 138 std::deque<Loop *> LQ; 139 bool skipThisLoop; 140 bool redoThisLoop; 141 LoopInfo *LI; 142 Loop *CurrentLoop; 143}; 144 145} // End llvm namespace 146 147#endif 148