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