1 //===- AliasAnalysisCounter.cpp - Alias Analysis Query Counter ------------===// 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 implements a pass which can be used to count how many alias queries 11 // are being made and how the alias analysis implementation being used responds. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #include "llvm/Analysis/Passes.h" 16 #include "llvm/Analysis/AliasAnalysis.h" 17 #include "llvm/Assembly/Writer.h" 18 #include "llvm/Pass.h" 19 #include "llvm/Support/CommandLine.h" 20 #include "llvm/Support/Debug.h" 21 #include "llvm/Support/ErrorHandling.h" 22 #include "llvm/Support/raw_ostream.h" 23 using namespace llvm; 24 25 static cl::opt<bool> 26 PrintAll("count-aa-print-all-queries", cl::ReallyHidden, cl::init(true)); 27 static cl::opt<bool> 28 PrintAllFailures("count-aa-print-all-failed-queries", cl::ReallyHidden); 29 30 namespace { 31 class AliasAnalysisCounter : public ModulePass, public AliasAnalysis { 32 unsigned No, May, Partial, Must; 33 unsigned NoMR, JustRef, JustMod, MR; 34 Module *M; 35 public: 36 static char ID; // Class identification, replacement for typeinfo 37 AliasAnalysisCounter() : ModulePass(ID) { 38 initializeAliasAnalysisCounterPass(*PassRegistry::getPassRegistry()); 39 No = May = Partial = Must = 0; 40 NoMR = JustRef = JustMod = MR = 0; 41 } 42 43 void printLine(const char *Desc, unsigned Val, unsigned Sum) { 44 errs() << " " << Val << " " << Desc << " responses (" 45 << Val*100/Sum << "%)\n"; 46 } 47 ~AliasAnalysisCounter() { 48 unsigned AASum = No+May+Partial+Must; 49 unsigned MRSum = NoMR+JustRef+JustMod+MR; 50 if (AASum + MRSum) { // Print a report if any counted queries occurred... 51 errs() << "\n===== Alias Analysis Counter Report =====\n" 52 << " Analysis counted:\n" 53 << " " << AASum << " Total Alias Queries Performed\n"; 54 if (AASum) { 55 printLine("no alias", No, AASum); 56 printLine("may alias", May, AASum); 57 printLine("partial alias", Partial, AASum); 58 printLine("must alias", Must, AASum); 59 errs() << " Alias Analysis Counter Summary: " << No*100/AASum << "%/" 60 << May*100/AASum << "%/" 61 << Partial*100/AASum << "%/" 62 << Must*100/AASum<<"%\n\n"; 63 } 64 65 errs() << " " << MRSum << " Total Mod/Ref Queries Performed\n"; 66 if (MRSum) { 67 printLine("no mod/ref", NoMR, MRSum); 68 printLine("ref", JustRef, MRSum); 69 printLine("mod", JustMod, MRSum); 70 printLine("mod/ref", MR, MRSum); 71 errs() << " Mod/Ref Analysis Counter Summary: " <<NoMR*100/MRSum 72 << "%/" << JustRef*100/MRSum << "%/" << JustMod*100/MRSum 73 << "%/" << MR*100/MRSum <<"%\n\n"; 74 } 75 } 76 } 77 78 bool runOnModule(Module &M) { 79 this->M = &M; 80 InitializeAliasAnalysis(this); 81 return false; 82 } 83 84 virtual void getAnalysisUsage(AnalysisUsage &AU) const { 85 AliasAnalysis::getAnalysisUsage(AU); 86 AU.addRequired<AliasAnalysis>(); 87 AU.setPreservesAll(); 88 } 89 90 /// getAdjustedAnalysisPointer - This method is used when a pass implements 91 /// an analysis interface through multiple inheritance. If needed, it 92 /// should override this to adjust the this pointer as needed for the 93 /// specified pass info. 94 virtual void *getAdjustedAnalysisPointer(AnalysisID PI) { 95 if (PI == &AliasAnalysis::ID) 96 return (AliasAnalysis*)this; 97 return this; 98 } 99 100 // FIXME: We could count these too... 101 bool pointsToConstantMemory(const Location &Loc, bool OrLocal) { 102 return getAnalysis<AliasAnalysis>().pointsToConstantMemory(Loc, OrLocal); 103 } 104 105 // Forwarding functions: just delegate to a real AA implementation, counting 106 // the number of responses... 107 AliasResult alias(const Location &LocA, const Location &LocB); 108 109 ModRefResult getModRefInfo(ImmutableCallSite CS, 110 const Location &Loc); 111 ModRefResult getModRefInfo(ImmutableCallSite CS1, 112 ImmutableCallSite CS2) { 113 return AliasAnalysis::getModRefInfo(CS1,CS2); 114 } 115 }; 116 } 117 118 char AliasAnalysisCounter::ID = 0; 119 INITIALIZE_AG_PASS(AliasAnalysisCounter, AliasAnalysis, "count-aa", 120 "Count Alias Analysis Query Responses", false, true, false) 121 122 ModulePass *llvm::createAliasAnalysisCounterPass() { 123 return new AliasAnalysisCounter(); 124 } 125 126 AliasAnalysis::AliasResult 127 AliasAnalysisCounter::alias(const Location &LocA, const Location &LocB) { 128 AliasResult R = getAnalysis<AliasAnalysis>().alias(LocA, LocB); 129 130 const char *AliasString = 0; 131 switch (R) { 132 case NoAlias: No++; AliasString = "No alias"; break; 133 case MayAlias: May++; AliasString = "May alias"; break; 134 case PartialAlias: Partial++; AliasString = "Partial alias"; break; 135 case MustAlias: Must++; AliasString = "Must alias"; break; 136 } 137 138 if (PrintAll || (PrintAllFailures && R == MayAlias)) { 139 errs() << AliasString << ":\t"; 140 errs() << "[" << LocA.Size << "B] "; 141 WriteAsOperand(errs(), LocA.Ptr, true, M); 142 errs() << ", "; 143 errs() << "[" << LocB.Size << "B] "; 144 WriteAsOperand(errs(), LocB.Ptr, true, M); 145 errs() << "\n"; 146 } 147 148 return R; 149 } 150 151 AliasAnalysis::ModRefResult 152 AliasAnalysisCounter::getModRefInfo(ImmutableCallSite CS, 153 const Location &Loc) { 154 ModRefResult R = getAnalysis<AliasAnalysis>().getModRefInfo(CS, Loc); 155 156 const char *MRString = 0; 157 switch (R) { 158 case NoModRef: NoMR++; MRString = "NoModRef"; break; 159 case Ref: JustRef++; MRString = "JustRef"; break; 160 case Mod: JustMod++; MRString = "JustMod"; break; 161 case ModRef: MR++; MRString = "ModRef"; break; 162 } 163 164 if (PrintAll || (PrintAllFailures && R == ModRef)) { 165 errs() << MRString << ": Ptr: "; 166 errs() << "[" << Loc.Size << "B] "; 167 WriteAsOperand(errs(), Loc.Ptr, true, M); 168 errs() << "\t<->" << *CS.getInstruction() << '\n'; 169 } 170 return R; 171 } 172
