LCOV - code coverage report
Current view: top level - lib/Analysis - AliasAnalysisEvaluator.cpp (source / functions) Hit Total Coverage
Test: llvm-toolchain.info Lines: 250 275 90.9 %
Date: 2018-09-23 13:06:45 Functions: 15 16 93.8 %
Legend: Lines: hit not hit

          Line data    Source code
       1             : //===- AliasAnalysisEvaluator.cpp - Alias Analysis Accuracy Evaluator -----===//
       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             : #include "llvm/Analysis/AliasAnalysisEvaluator.h"
      11             : #include "llvm/ADT/SetVector.h"
      12             : #include "llvm/Analysis/AliasAnalysis.h"
      13             : #include "llvm/IR/Constants.h"
      14             : #include "llvm/IR/DataLayout.h"
      15             : #include "llvm/IR/DerivedTypes.h"
      16             : #include "llvm/IR/Function.h"
      17             : #include "llvm/IR/InstIterator.h"
      18             : #include "llvm/IR/Instructions.h"
      19             : #include "llvm/IR/Module.h"
      20             : #include "llvm/Pass.h"
      21             : #include "llvm/Support/CommandLine.h"
      22             : #include "llvm/Support/Debug.h"
      23             : #include "llvm/Support/raw_ostream.h"
      24             : using namespace llvm;
      25             : 
      26             : static cl::opt<bool> PrintAll("print-all-alias-modref-info", cl::ReallyHidden);
      27             : 
      28             : static cl::opt<bool> PrintNoAlias("print-no-aliases", cl::ReallyHidden);
      29             : static cl::opt<bool> PrintMayAlias("print-may-aliases", cl::ReallyHidden);
      30             : static cl::opt<bool> PrintPartialAlias("print-partial-aliases", cl::ReallyHidden);
      31             : static cl::opt<bool> PrintMustAlias("print-must-aliases", cl::ReallyHidden);
      32             : 
      33             : static cl::opt<bool> PrintNoModRef("print-no-modref", cl::ReallyHidden);
      34             : static cl::opt<bool> PrintRef("print-ref", cl::ReallyHidden);
      35             : static cl::opt<bool> PrintMod("print-mod", cl::ReallyHidden);
      36             : static cl::opt<bool> PrintModRef("print-modref", cl::ReallyHidden);
      37             : static cl::opt<bool> PrintMust("print-must", cl::ReallyHidden);
      38             : static cl::opt<bool> PrintMustRef("print-mustref", cl::ReallyHidden);
      39             : static cl::opt<bool> PrintMustMod("print-mustmod", cl::ReallyHidden);
      40             : static cl::opt<bool> PrintMustModRef("print-mustmodref", cl::ReallyHidden);
      41             : 
      42             : static cl::opt<bool> EvalAAMD("evaluate-aa-metadata", cl::ReallyHidden);
      43             : 
      44        5205 : static void PrintResults(AliasResult AR, bool P, const Value *V1,
      45             :                          const Value *V2, const Module *M) {
      46        5205 :   if (PrintAll || P) {
      47             :     std::string o1, o2;
      48             :     {
      49        4890 :       raw_string_ostream os1(o1), os2(o2);
      50        4890 :       V1->printAsOperand(os1, true, M);
      51        4890 :       V2->printAsOperand(os2, true, M);
      52             :     }
      53             : 
      54        4890 :     if (o2 < o1)
      55             :       std::swap(o1, o2);
      56       14670 :     errs() << "  " << AR << ":\t" << o1 << ", " << o2 << "\n";
      57             :   }
      58        5205 : }
      59             : 
      60         958 : static inline void PrintModRefResults(const char *Msg, bool P, Instruction *I,
      61             :                                       Value *Ptr, Module *M) {
      62         958 :   if (PrintAll || P) {
      63         890 :     errs() << "  " << Msg << ":  Ptr: ";
      64         890 :     Ptr->printAsOperand(errs(), true, M);
      65         890 :     errs() << "\t<->" << *I << '\n';
      66             :   }
      67         958 : }
      68             : 
      69         274 : static inline void PrintModRefResults(const char *Msg, bool P, CallSite CSA,
      70             :                                       CallSite CSB, Module *M) {
      71         274 :   if (PrintAll || P) {
      72         272 :     errs() << "  " << Msg << ": " << *CSA.getInstruction() << " <-> "
      73         272 :            << *CSB.getInstruction() << '\n';
      74             :   }
      75         274 : }
      76             : 
      77         730 : static inline void PrintLoadStoreResults(AliasResult AR, bool P,
      78             :                                          const Value *V1, const Value *V2,
      79             :                                          const Module *M) {
      80         730 :   if (PrintAll || P) {
      81        1286 :     errs() << "  " << AR << ": " << *V1 << " <-> " << *V2 << '\n';
      82             :   }
      83         730 : }
      84             : 
      85             : static inline bool isInterestingPointer(Value *V) {
      86           1 :   return V->getType()->isPointerTy()
      87        3869 :       && !isa<ConstantPointerNull>(V);
      88             : }
      89             : 
      90          99 : PreservedAnalyses AAEvaluator::run(Function &F, FunctionAnalysisManager &AM) {
      91          99 :   runInternal(F, AM.getResult<AAManager>(F));
      92          99 :   return PreservedAnalyses::all();
      93             : }
      94             : 
      95         375 : void AAEvaluator::runInternal(Function &F, AAResults &AA) {
      96         375 :   const DataLayout &DL = F.getParent()->getDataLayout();
      97             : 
      98         375 :   ++FunctionCount;
      99             : 
     100         375 :   SetVector<Value *> Pointers;
     101             :   SmallSetVector<CallSite, 16> CallSites;
     102         375 :   SetVector<Value *> Loads;
     103         375 :   SetVector<Value *> Stores;
     104             : 
     105         973 :   for (auto &I : F.args())
     106        1196 :     if (I.getType()->isPointerTy())    // Add all pointer arguments.
     107         448 :       Pointers.insert(&I);
     108             : 
     109        2598 :   for (inst_iterator I = inst_begin(F), E = inst_end(F); I != E; ++I) {
     110        5196 :     if (I->getType()->isPointerTy()) // Add all pointer instructions.
     111        1155 :       Pointers.insert(&*I);
     112        3032 :     if (EvalAAMD && isa<LoadInst>(&*I))
     113          90 :       Loads.insert(&*I);
     114        3032 :     if (EvalAAMD && isa<StoreInst>(&*I))
     115         126 :       Stores.insert(&*I);
     116             :     Instruction &Inst = *I;
     117        2598 :     if (auto CS = CallSite(&Inst)) {
     118         226 :       Value *Callee = CS.getCalledValue();
     119             :       // Skip actual functions for direct function calls.
     120         226 :       if (!isa<Function>(Callee) && isInterestingPointer(Callee))
     121           1 :         Pointers.insert(Callee);
     122             :       // Consider formals.
     123         544 :       for (Use &DataOp : CS.data_ops())
     124         318 :         if (isInterestingPointer(DataOp))
     125         218 :           Pointers.insert(DataOp);
     126         226 :       CallSites.insert(CS);
     127             :     } else {
     128             :       // Consider all operands.
     129        5922 :       for (Instruction::op_iterator OI = Inst.op_begin(), OE = Inst.op_end();
     130        5922 :            OI != OE; ++OI)
     131        3550 :         if (isInterestingPointer(*OI))
     132        1456 :           Pointers.insert(*OI);
     133             :     }
     134             :   }
     135             : 
     136          73 :   if (PrintAll || PrintNoAlias || PrintMayAlias || PrintPartialAlias ||
     137         389 :       PrintMustAlias || PrintNoModRef || PrintMod || PrintRef || PrintModRef)
     138         361 :     errs() << "Function: " << F.getName() << ": " << Pointers.size()
     139         361 :            << " pointers, " << CallSites.size() << " call sites\n";
     140             : 
     141             :   // iterate over the worklist, and run the full (n^2)/2 disambiguations
     142             :   for (SetVector<Value *>::iterator I1 = Pointers.begin(), E = Pointers.end();
     143        2036 :        I1 != E; ++I1) {
     144             :     uint64_t I1Size = MemoryLocation::UnknownSize;
     145        1661 :     Type *I1ElTy = cast<PointerType>((*I1)->getType())->getElementType();
     146        1661 :     if (I1ElTy->isSized()) I1Size = DL.getTypeStoreSize(I1ElTy);
     147             : 
     148        6866 :     for (SetVector<Value *>::iterator I2 = Pointers.begin(); I2 != I1; ++I2) {
     149             :       uint64_t I2Size = MemoryLocation::UnknownSize;
     150        5205 :       Type *I2ElTy =cast<PointerType>((*I2)->getType())->getElementType();
     151        5205 :       if (I2ElTy->isSized()) I2Size = DL.getTypeStoreSize(I2ElTy);
     152             : 
     153        5205 :       AliasResult AR = AA.alias(*I1, I1Size, *I2, I2Size);
     154        5205 :       switch (AR) {
     155        1999 :       case NoAlias:
     156        3998 :         PrintResults(AR, PrintNoAlias, *I1, *I2, F.getParent());
     157        1999 :         ++NoAliasCount;
     158        1999 :         break;
     159        2831 :       case MayAlias:
     160        5662 :         PrintResults(AR, PrintMayAlias, *I1, *I2, F.getParent());
     161        2831 :         ++MayAliasCount;
     162        2831 :         break;
     163         138 :       case PartialAlias:
     164         276 :         PrintResults(AR, PrintPartialAlias, *I1, *I2, F.getParent());
     165         138 :         ++PartialAliasCount;
     166         138 :         break;
     167         237 :       case MustAlias:
     168         474 :         PrintResults(AR, PrintMustAlias, *I1, *I2, F.getParent());
     169         237 :         ++MustAliasCount;
     170         237 :         break;
     171             :       }
     172             :     }
     173             :   }
     174             : 
     175         375 :   if (EvalAAMD) {
     176             :     // iterate over all pairs of load, store
     177         126 :     for (Value *Load : Loads) {
     178         591 :       for (Value *Store : Stores) {
     179         501 :         AliasResult AR = AA.alias(MemoryLocation::get(cast<LoadInst>(Load)),
     180         501 :                                   MemoryLocation::get(cast<StoreInst>(Store)));
     181         501 :         switch (AR) {
     182         378 :         case NoAlias:
     183         756 :           PrintLoadStoreResults(AR, PrintNoAlias, Load, Store, F.getParent());
     184         378 :           ++NoAliasCount;
     185         378 :           break;
     186          40 :         case MayAlias:
     187          80 :           PrintLoadStoreResults(AR, PrintMayAlias, Load, Store, F.getParent());
     188          40 :           ++MayAliasCount;
     189          40 :           break;
     190           0 :         case PartialAlias:
     191           0 :           PrintLoadStoreResults(AR, PrintPartialAlias, Load, Store, F.getParent());
     192           0 :           ++PartialAliasCount;
     193           0 :           break;
     194          83 :         case MustAlias:
     195         166 :           PrintLoadStoreResults(AR, PrintMustAlias, Load, Store, F.getParent());
     196          83 :           ++MustAliasCount;
     197          83 :           break;
     198             :         }
     199             :       }
     200             :     }
     201             : 
     202             :     // iterate over all pairs of store, store
     203             :     for (SetVector<Value *>::iterator I1 = Stores.begin(), E = Stores.end();
     204         162 :          I1 != E; ++I1) {
     205         355 :       for (SetVector<Value *>::iterator I2 = Stores.begin(); I2 != I1; ++I2) {
     206         229 :         AliasResult AR = AA.alias(MemoryLocation::get(cast<StoreInst>(*I1)),
     207         229 :                                   MemoryLocation::get(cast<StoreInst>(*I2)));
     208         229 :         switch (AR) {
     209         212 :         case NoAlias:
     210         424 :           PrintLoadStoreResults(AR, PrintNoAlias, *I1, *I2, F.getParent());
     211         212 :           ++NoAliasCount;
     212         212 :           break;
     213          13 :         case MayAlias:
     214          26 :           PrintLoadStoreResults(AR, PrintMayAlias, *I1, *I2, F.getParent());
     215          13 :           ++MayAliasCount;
     216          13 :           break;
     217           0 :         case PartialAlias:
     218           0 :           PrintLoadStoreResults(AR, PrintPartialAlias, *I1, *I2, F.getParent());
     219           0 :           ++PartialAliasCount;
     220           0 :           break;
     221           4 :         case MustAlias:
     222           8 :           PrintLoadStoreResults(AR, PrintMustAlias, *I1, *I2, F.getParent());
     223           4 :           ++MustAliasCount;
     224           4 :           break;
     225             :         }
     226             :       }
     227             :     }
     228             :   }
     229             : 
     230             :   // Mod/ref alias analysis: compare all pairs of calls and values
     231         601 :   for (CallSite C : CallSites) {
     232             :     Instruction *I = C.getInstruction();
     233             : 
     234        1184 :     for (auto Pointer : Pointers) {
     235             :       uint64_t Size = MemoryLocation::UnknownSize;
     236         958 :       Type *ElTy = cast<PointerType>(Pointer->getType())->getElementType();
     237         958 :       if (ElTy->isSized()) Size = DL.getTypeStoreSize(ElTy);
     238             : 
     239         958 :       switch (AA.getModRefInfo(C, Pointer, Size)) {
     240          98 :       case ModRefInfo::NoModRef:
     241         196 :         PrintModRefResults("NoModRef", PrintNoModRef, I, Pointer,
     242             :                            F.getParent());
     243          98 :         ++NoModRefCount;
     244          98 :         break;
     245          31 :       case ModRefInfo::Mod:
     246          62 :         PrintModRefResults("Just Mod", PrintMod, I, Pointer, F.getParent());
     247          31 :         ++ModCount;
     248          31 :         break;
     249          41 :       case ModRefInfo::Ref:
     250          82 :         PrintModRefResults("Just Ref", PrintRef, I, Pointer, F.getParent());
     251          41 :         ++RefCount;
     252          41 :         break;
     253         777 :       case ModRefInfo::ModRef:
     254        1554 :         PrintModRefResults("Both ModRef", PrintModRef, I, Pointer,
     255             :                            F.getParent());
     256         777 :         ++ModRefCount;
     257         777 :         break;
     258           0 :       case ModRefInfo::Must:
     259           0 :         PrintModRefResults("Must", PrintMust, I, Pointer, F.getParent());
     260           0 :         ++MustCount;
     261           0 :         break;
     262           5 :       case ModRefInfo::MustMod:
     263          10 :         PrintModRefResults("Just Mod (MustAlias)", PrintMustMod, I, Pointer,
     264             :                            F.getParent());
     265           5 :         ++MustModCount;
     266           5 :         break;
     267           2 :       case ModRefInfo::MustRef:
     268           4 :         PrintModRefResults("Just Ref (MustAlias)", PrintMustRef, I, Pointer,
     269             :                            F.getParent());
     270           2 :         ++MustRefCount;
     271           2 :         break;
     272           4 :       case ModRefInfo::MustModRef:
     273           8 :         PrintModRefResults("Both ModRef (MustAlias)", PrintMustModRef, I,
     274             :                            Pointer, F.getParent());
     275           4 :         ++MustModRefCount;
     276           4 :         break;
     277             :       }
     278             :     }
     279             :   }
     280             : 
     281             :   // Mod/ref alias analysis: compare all pairs of calls
     282         601 :   for (auto C = CallSites.begin(), Ce = CallSites.end(); C != Ce; ++C) {
     283         726 :     for (auto D = CallSites.begin(); D != Ce; ++D) {
     284         500 :       if (D == C)
     285             :         continue;
     286         274 :       switch (AA.getModRefInfo(*C, *D)) {
     287          32 :       case ModRefInfo::NoModRef:
     288          64 :         PrintModRefResults("NoModRef", PrintNoModRef, *C, *D, F.getParent());
     289          32 :         ++NoModRefCount;
     290          32 :         break;
     291          35 :       case ModRefInfo::Mod:
     292          70 :         PrintModRefResults("Just Mod", PrintMod, *C, *D, F.getParent());
     293          35 :         ++ModCount;
     294          35 :         break;
     295          19 :       case ModRefInfo::Ref:
     296          38 :         PrintModRefResults("Just Ref", PrintRef, *C, *D, F.getParent());
     297          19 :         ++RefCount;
     298          19 :         break;
     299         184 :       case ModRefInfo::ModRef:
     300         368 :         PrintModRefResults("Both ModRef", PrintModRef, *C, *D, F.getParent());
     301         184 :         ++ModRefCount;
     302         184 :         break;
     303           0 :       case ModRefInfo::Must:
     304           0 :         PrintModRefResults("Must", PrintMust, *C, *D, F.getParent());
     305           0 :         ++MustCount;
     306           0 :         break;
     307           0 :       case ModRefInfo::MustMod:
     308           0 :         PrintModRefResults("Just Mod (MustAlias)", PrintMustMod, *C, *D,
     309             :                            F.getParent());
     310           0 :         ++MustModCount;
     311           0 :         break;
     312           0 :       case ModRefInfo::MustRef:
     313           0 :         PrintModRefResults("Just Ref (MustAlias)", PrintMustRef, *C, *D,
     314             :                            F.getParent());
     315           0 :         ++MustRefCount;
     316           0 :         break;
     317           4 :       case ModRefInfo::MustModRef:
     318           8 :         PrintModRefResults("Both ModRef (MustAlias)", PrintMustModRef, *C, *D,
     319             :                            F.getParent());
     320           4 :         ++MustModRefCount;
     321           4 :         break;
     322             :       }
     323             :     }
     324             :   }
     325         375 : }
     326             : 
     327        1244 : static void PrintPercent(int64_t Num, int64_t Sum) {
     328        1244 :   errs() << "(" << Num * 100LL / Sum << "." << ((Num * 1000LL / Sum) % 10)
     329        1244 :          << "%)\n";
     330        1244 : }
     331             : 
     332         153 : AAEvaluator::~AAEvaluator() {
     333         243 :   if (FunctionCount == 0)
     334          90 :     return;
     335             : 
     336         153 :   int64_t AliasSum =
     337         153 :       NoAliasCount + MayAliasCount + PartialAliasCount + MustAliasCount;
     338         153 :   errs() << "===== Alias Analysis Evaluator Report =====\n";
     339         153 :   if (AliasSum == 0) {
     340           2 :     errs() << "  Alias Analysis Evaluator Summary: No pointers!\n";
     341             :   } else {
     342         151 :     errs() << "  " << AliasSum << " Total Alias Queries Performed\n";
     343         151 :     errs() << "  " << NoAliasCount << " no alias responses ";
     344         151 :     PrintPercent(NoAliasCount, AliasSum);
     345         151 :     errs() << "  " << MayAliasCount << " may alias responses ";
     346         151 :     PrintPercent(MayAliasCount, AliasSum);
     347         151 :     errs() << "  " << PartialAliasCount << " partial alias responses ";
     348         151 :     PrintPercent(PartialAliasCount, AliasSum);
     349         151 :     errs() << "  " << MustAliasCount << " must alias responses ";
     350         151 :     PrintPercent(MustAliasCount, AliasSum);
     351         151 :     errs() << "  Alias Analysis Evaluator Pointer Alias Summary: "
     352         151 :            << NoAliasCount * 100 / AliasSum << "%/"
     353         151 :            << MayAliasCount * 100 / AliasSum << "%/"
     354         151 :            << PartialAliasCount * 100 / AliasSum << "%/"
     355         151 :            << MustAliasCount * 100 / AliasSum << "%\n";
     356             :   }
     357             : 
     358             :   // Display the summary for mod/ref analysis
     359         459 :   int64_t ModRefSum = NoModRefCount + RefCount + ModCount + ModRefCount +
     360         306 :                       MustCount + MustRefCount + MustModCount + MustModRefCount;
     361         153 :   if (ModRefSum == 0) {
     362          73 :     errs() << "  Alias Analysis Mod/Ref Evaluator Summary: no "
     363          73 :               "mod/ref!\n";
     364             :   } else {
     365          80 :     errs() << "  " << ModRefSum << " Total ModRef Queries Performed\n";
     366          80 :     errs() << "  " << NoModRefCount << " no mod/ref responses ";
     367          80 :     PrintPercent(NoModRefCount, ModRefSum);
     368          80 :     errs() << "  " << ModCount << " mod responses ";
     369          80 :     PrintPercent(ModCount, ModRefSum);
     370          80 :     errs() << "  " << RefCount << " ref responses ";
     371          80 :     PrintPercent(RefCount, ModRefSum);
     372          80 :     errs() << "  " << ModRefCount << " mod & ref responses ";
     373          80 :     PrintPercent(ModRefCount, ModRefSum);
     374          80 :     errs() << "  " << MustCount << " must responses ";
     375          80 :     PrintPercent(MustCount, ModRefSum);
     376          80 :     errs() << "  " << MustModCount << " must mod responses ";
     377          80 :     PrintPercent(MustModCount, ModRefSum);
     378          80 :     errs() << "  " << MustRefCount << " must ref responses ";
     379          80 :     PrintPercent(MustRefCount, ModRefSum);
     380          80 :     errs() << "  " << MustModRefCount << " must mod & ref responses ";
     381          80 :     PrintPercent(MustModRefCount, ModRefSum);
     382          80 :     errs() << "  Alias Analysis Evaluator Mod/Ref Summary: "
     383          80 :            << NoModRefCount * 100 / ModRefSum << "%/"
     384          80 :            << ModCount * 100 / ModRefSum << "%/" << RefCount * 100 / ModRefSum
     385          80 :            << "%/" << ModRefCount * 100 / ModRefSum << "%/"
     386          80 :            << MustCount * 100 / ModRefSum << "%/"
     387          80 :            << MustRefCount * 100 / ModRefSum << "%/"
     388          80 :            << MustModCount * 100 / ModRefSum << "%/"
     389          80 :            << MustModRefCount * 100 / ModRefSum << "%\n";
     390             :   }
     391         243 : }
     392             : 
     393             : namespace llvm {
     394             : class AAEvalLegacyPass : public FunctionPass {
     395             :   std::unique_ptr<AAEvaluator> P;
     396             : 
     397             : public:
     398             :   static char ID; // Pass identification, replacement for typeid
     399         216 :   AAEvalLegacyPass() : FunctionPass(ID) {
     400         108 :     initializeAAEvalLegacyPassPass(*PassRegistry::getPassRegistry());
     401         108 :   }
     402             : 
     403         108 :   void getAnalysisUsage(AnalysisUsage &AU) const override {
     404             :     AU.addRequired<AAResultsWrapperPass>();
     405             :     AU.setPreservesAll();
     406         108 :   }
     407             : 
     408         108 :   bool doInitialization(Module &M) override {
     409         108 :     P.reset(new AAEvaluator());
     410         108 :     return false;
     411             :   }
     412             : 
     413         276 :   bool runOnFunction(Function &F) override {
     414         276 :     P->runInternal(F, getAnalysis<AAResultsWrapperPass>().getAAResults());
     415         276 :     return false;
     416             :   }
     417         108 :   bool doFinalization(Module &M) override {
     418             :     P.reset();
     419         108 :     return false;
     420             :   }
     421             : };
     422             : }
     423             : 
     424             : char AAEvalLegacyPass::ID = 0;
     425       10671 : INITIALIZE_PASS_BEGIN(AAEvalLegacyPass, "aa-eval",
     426             :                       "Exhaustive Alias Analysis Precision Evaluator", false,
     427             :                       true)
     428       10671 : INITIALIZE_PASS_DEPENDENCY(AAResultsWrapperPass)
     429       21450 : INITIALIZE_PASS_END(AAEvalLegacyPass, "aa-eval",
     430             :                     "Exhaustive Alias Analysis Precision Evaluator", false,
     431             :                     true)
     432             : 
     433           0 : FunctionPass *llvm::createAAEvalPass() { return new AAEvalLegacyPass(); }

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