436 lines
		
	
	
		
			16 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			436 lines
		
	
	
		
			16 KiB
		
	
	
	
		
			C++
		
	
	
	
| //===- AliasAnalysisEvaluator.cpp - Alias Analysis Accuracy Evaluator -----===//
 | |
| //
 | |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 | |
| // See https://llvm.org/LICENSE.txt for license information.
 | |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 | |
| //
 | |
| //===----------------------------------------------------------------------===//
 | |
| 
 | |
| #include "llvm/Analysis/AliasAnalysisEvaluator.h"
 | |
| #include "llvm/ADT/SetVector.h"
 | |
| #include "llvm/Analysis/AliasAnalysis.h"
 | |
| #include "llvm/IR/Constants.h"
 | |
| #include "llvm/IR/DataLayout.h"
 | |
| #include "llvm/IR/DerivedTypes.h"
 | |
| #include "llvm/IR/Function.h"
 | |
| #include "llvm/IR/InstIterator.h"
 | |
| #include "llvm/IR/Instructions.h"
 | |
| #include "llvm/IR/Module.h"
 | |
| #include "llvm/InitializePasses.h"
 | |
| #include "llvm/Pass.h"
 | |
| #include "llvm/Support/CommandLine.h"
 | |
| #include "llvm/Support/Debug.h"
 | |
| #include "llvm/Support/raw_ostream.h"
 | |
| using namespace llvm;
 | |
| 
 | |
| static cl::opt<bool> PrintAll("print-all-alias-modref-info", cl::ReallyHidden);
 | |
| 
 | |
| static cl::opt<bool> PrintNoAlias("print-no-aliases", cl::ReallyHidden);
 | |
| static cl::opt<bool> PrintMayAlias("print-may-aliases", cl::ReallyHidden);
 | |
| static cl::opt<bool> PrintPartialAlias("print-partial-aliases", cl::ReallyHidden);
 | |
| static cl::opt<bool> PrintMustAlias("print-must-aliases", cl::ReallyHidden);
 | |
| 
 | |
| static cl::opt<bool> PrintNoModRef("print-no-modref", cl::ReallyHidden);
 | |
| static cl::opt<bool> PrintRef("print-ref", cl::ReallyHidden);
 | |
| static cl::opt<bool> PrintMod("print-mod", cl::ReallyHidden);
 | |
| static cl::opt<bool> PrintModRef("print-modref", cl::ReallyHidden);
 | |
| static cl::opt<bool> PrintMust("print-must", cl::ReallyHidden);
 | |
| static cl::opt<bool> PrintMustRef("print-mustref", cl::ReallyHidden);
 | |
| static cl::opt<bool> PrintMustMod("print-mustmod", cl::ReallyHidden);
 | |
| static cl::opt<bool> PrintMustModRef("print-mustmodref", cl::ReallyHidden);
 | |
| 
 | |
| static cl::opt<bool> EvalAAMD("evaluate-aa-metadata", cl::ReallyHidden);
 | |
| 
 | |
| static void PrintResults(AliasResult AR, bool P, const Value *V1,
 | |
|                          const Value *V2, const Module *M) {
 | |
|   if (PrintAll || P) {
 | |
|     std::string o1, o2;
 | |
|     {
 | |
|       raw_string_ostream os1(o1), os2(o2);
 | |
|       V1->printAsOperand(os1, true, M);
 | |
|       V2->printAsOperand(os2, true, M);
 | |
|     }
 | |
| 
 | |
|     if (o2 < o1)
 | |
|       std::swap(o1, o2);
 | |
|     errs() << "  " << AR << ":\t" << o1 << ", " << o2 << "\n";
 | |
|   }
 | |
| }
 | |
| 
 | |
| static inline void PrintModRefResults(const char *Msg, bool P, Instruction *I,
 | |
|                                       Value *Ptr, Module *M) {
 | |
|   if (PrintAll || P) {
 | |
|     errs() << "  " << Msg << ":  Ptr: ";
 | |
|     Ptr->printAsOperand(errs(), true, M);
 | |
|     errs() << "\t<->" << *I << '\n';
 | |
|   }
 | |
| }
 | |
| 
 | |
| static inline void PrintModRefResults(const char *Msg, bool P, CallBase *CallA,
 | |
|                                       CallBase *CallB, Module *M) {
 | |
|   if (PrintAll || P) {
 | |
|     errs() << "  " << Msg << ": " << *CallA << " <-> " << *CallB << '\n';
 | |
|   }
 | |
| }
 | |
| 
 | |
| static inline void PrintLoadStoreResults(AliasResult AR, bool P,
 | |
|                                          const Value *V1, const Value *V2,
 | |
|                                          const Module *M) {
 | |
|   if (PrintAll || P) {
 | |
|     errs() << "  " << AR << ": " << *V1 << " <-> " << *V2 << '\n';
 | |
|   }
 | |
| }
 | |
| 
 | |
| static inline bool isInterestingPointer(Value *V) {
 | |
|   return V->getType()->isPointerTy()
 | |
|       && !isa<ConstantPointerNull>(V);
 | |
| }
 | |
| 
 | |
| PreservedAnalyses AAEvaluator::run(Function &F, FunctionAnalysisManager &AM) {
 | |
|   runInternal(F, AM.getResult<AAManager>(F));
 | |
|   return PreservedAnalyses::all();
 | |
| }
 | |
| 
 | |
| void AAEvaluator::runInternal(Function &F, AAResults &AA) {
 | |
|   const DataLayout &DL = F.getParent()->getDataLayout();
 | |
| 
 | |
|   ++FunctionCount;
 | |
| 
 | |
|   SetVector<Value *> Pointers;
 | |
|   SmallSetVector<CallBase *, 16> Calls;
 | |
|   SetVector<Value *> Loads;
 | |
|   SetVector<Value *> Stores;
 | |
| 
 | |
|   for (auto &I : F.args())
 | |
|     if (I.getType()->isPointerTy())    // Add all pointer arguments.
 | |
|       Pointers.insert(&I);
 | |
| 
 | |
|   for (inst_iterator I = inst_begin(F), E = inst_end(F); I != E; ++I) {
 | |
|     if (I->getType()->isPointerTy()) // Add all pointer instructions.
 | |
|       Pointers.insert(&*I);
 | |
|     if (EvalAAMD && isa<LoadInst>(&*I))
 | |
|       Loads.insert(&*I);
 | |
|     if (EvalAAMD && isa<StoreInst>(&*I))
 | |
|       Stores.insert(&*I);
 | |
|     Instruction &Inst = *I;
 | |
|     if (auto *Call = dyn_cast<CallBase>(&Inst)) {
 | |
|       Value *Callee = Call->getCalledOperand();
 | |
|       // Skip actual functions for direct function calls.
 | |
|       if (!isa<Function>(Callee) && isInterestingPointer(Callee))
 | |
|         Pointers.insert(Callee);
 | |
|       // Consider formals.
 | |
|       for (Use &DataOp : Call->data_ops())
 | |
|         if (isInterestingPointer(DataOp))
 | |
|           Pointers.insert(DataOp);
 | |
|       Calls.insert(Call);
 | |
|     } else {
 | |
|       // Consider all operands.
 | |
|       for (Instruction::op_iterator OI = Inst.op_begin(), OE = Inst.op_end();
 | |
|            OI != OE; ++OI)
 | |
|         if (isInterestingPointer(*OI))
 | |
|           Pointers.insert(*OI);
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   if (PrintAll || PrintNoAlias || PrintMayAlias || PrintPartialAlias ||
 | |
|       PrintMustAlias || PrintNoModRef || PrintMod || PrintRef || PrintModRef)
 | |
|     errs() << "Function: " << F.getName() << ": " << Pointers.size()
 | |
|            << " pointers, " << Calls.size() << " call sites\n";
 | |
| 
 | |
|   // iterate over the worklist, and run the full (n^2)/2 disambiguations
 | |
|   for (SetVector<Value *>::iterator I1 = Pointers.begin(), E = Pointers.end();
 | |
|        I1 != E; ++I1) {
 | |
|     auto I1Size = LocationSize::afterPointer();
 | |
|     Type *I1ElTy = cast<PointerType>((*I1)->getType())->getElementType();
 | |
|     if (I1ElTy->isSized())
 | |
|       I1Size = LocationSize::precise(DL.getTypeStoreSize(I1ElTy));
 | |
| 
 | |
|     for (SetVector<Value *>::iterator I2 = Pointers.begin(); I2 != I1; ++I2) {
 | |
|       auto I2Size = LocationSize::afterPointer();
 | |
|       Type *I2ElTy = cast<PointerType>((*I2)->getType())->getElementType();
 | |
|       if (I2ElTy->isSized())
 | |
|         I2Size = LocationSize::precise(DL.getTypeStoreSize(I2ElTy));
 | |
| 
 | |
|       AliasResult AR = AA.alias(*I1, I1Size, *I2, I2Size);
 | |
|       switch (AR) {
 | |
|       case NoAlias:
 | |
|         PrintResults(AR, PrintNoAlias, *I1, *I2, F.getParent());
 | |
|         ++NoAliasCount;
 | |
|         break;
 | |
|       case MayAlias:
 | |
|         PrintResults(AR, PrintMayAlias, *I1, *I2, F.getParent());
 | |
|         ++MayAliasCount;
 | |
|         break;
 | |
|       case PartialAlias:
 | |
|         PrintResults(AR, PrintPartialAlias, *I1, *I2, F.getParent());
 | |
|         ++PartialAliasCount;
 | |
|         break;
 | |
|       case MustAlias:
 | |
|         PrintResults(AR, PrintMustAlias, *I1, *I2, F.getParent());
 | |
|         ++MustAliasCount;
 | |
|         break;
 | |
|       }
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   if (EvalAAMD) {
 | |
|     // iterate over all pairs of load, store
 | |
|     for (Value *Load : Loads) {
 | |
|       for (Value *Store : Stores) {
 | |
|         AliasResult AR = AA.alias(MemoryLocation::get(cast<LoadInst>(Load)),
 | |
|                                   MemoryLocation::get(cast<StoreInst>(Store)));
 | |
|         switch (AR) {
 | |
|         case NoAlias:
 | |
|           PrintLoadStoreResults(AR, PrintNoAlias, Load, Store, F.getParent());
 | |
|           ++NoAliasCount;
 | |
|           break;
 | |
|         case MayAlias:
 | |
|           PrintLoadStoreResults(AR, PrintMayAlias, Load, Store, F.getParent());
 | |
|           ++MayAliasCount;
 | |
|           break;
 | |
|         case PartialAlias:
 | |
|           PrintLoadStoreResults(AR, PrintPartialAlias, Load, Store, F.getParent());
 | |
|           ++PartialAliasCount;
 | |
|           break;
 | |
|         case MustAlias:
 | |
|           PrintLoadStoreResults(AR, PrintMustAlias, Load, Store, F.getParent());
 | |
|           ++MustAliasCount;
 | |
|           break;
 | |
|         }
 | |
|       }
 | |
|     }
 | |
| 
 | |
|     // iterate over all pairs of store, store
 | |
|     for (SetVector<Value *>::iterator I1 = Stores.begin(), E = Stores.end();
 | |
|          I1 != E; ++I1) {
 | |
|       for (SetVector<Value *>::iterator I2 = Stores.begin(); I2 != I1; ++I2) {
 | |
|         AliasResult AR = AA.alias(MemoryLocation::get(cast<StoreInst>(*I1)),
 | |
|                                   MemoryLocation::get(cast<StoreInst>(*I2)));
 | |
|         switch (AR) {
 | |
|         case NoAlias:
 | |
|           PrintLoadStoreResults(AR, PrintNoAlias, *I1, *I2, F.getParent());
 | |
|           ++NoAliasCount;
 | |
|           break;
 | |
|         case MayAlias:
 | |
|           PrintLoadStoreResults(AR, PrintMayAlias, *I1, *I2, F.getParent());
 | |
|           ++MayAliasCount;
 | |
|           break;
 | |
|         case PartialAlias:
 | |
|           PrintLoadStoreResults(AR, PrintPartialAlias, *I1, *I2, F.getParent());
 | |
|           ++PartialAliasCount;
 | |
|           break;
 | |
|         case MustAlias:
 | |
|           PrintLoadStoreResults(AR, PrintMustAlias, *I1, *I2, F.getParent());
 | |
|           ++MustAliasCount;
 | |
|           break;
 | |
|         }
 | |
|       }
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   // Mod/ref alias analysis: compare all pairs of calls and values
 | |
|   for (CallBase *Call : Calls) {
 | |
|     for (auto Pointer : Pointers) {
 | |
|       auto Size = LocationSize::afterPointer();
 | |
|       Type *ElTy = cast<PointerType>(Pointer->getType())->getElementType();
 | |
|       if (ElTy->isSized())
 | |
|         Size = LocationSize::precise(DL.getTypeStoreSize(ElTy));
 | |
| 
 | |
|       switch (AA.getModRefInfo(Call, Pointer, Size)) {
 | |
|       case ModRefInfo::NoModRef:
 | |
|         PrintModRefResults("NoModRef", PrintNoModRef, Call, Pointer,
 | |
|                            F.getParent());
 | |
|         ++NoModRefCount;
 | |
|         break;
 | |
|       case ModRefInfo::Mod:
 | |
|         PrintModRefResults("Just Mod", PrintMod, Call, Pointer, F.getParent());
 | |
|         ++ModCount;
 | |
|         break;
 | |
|       case ModRefInfo::Ref:
 | |
|         PrintModRefResults("Just Ref", PrintRef, Call, Pointer, F.getParent());
 | |
|         ++RefCount;
 | |
|         break;
 | |
|       case ModRefInfo::ModRef:
 | |
|         PrintModRefResults("Both ModRef", PrintModRef, Call, Pointer,
 | |
|                            F.getParent());
 | |
|         ++ModRefCount;
 | |
|         break;
 | |
|       case ModRefInfo::Must:
 | |
|         PrintModRefResults("Must", PrintMust, Call, Pointer, F.getParent());
 | |
|         ++MustCount;
 | |
|         break;
 | |
|       case ModRefInfo::MustMod:
 | |
|         PrintModRefResults("Just Mod (MustAlias)", PrintMustMod, Call, Pointer,
 | |
|                            F.getParent());
 | |
|         ++MustModCount;
 | |
|         break;
 | |
|       case ModRefInfo::MustRef:
 | |
|         PrintModRefResults("Just Ref (MustAlias)", PrintMustRef, Call, Pointer,
 | |
|                            F.getParent());
 | |
|         ++MustRefCount;
 | |
|         break;
 | |
|       case ModRefInfo::MustModRef:
 | |
|         PrintModRefResults("Both ModRef (MustAlias)", PrintMustModRef, Call,
 | |
|                            Pointer, F.getParent());
 | |
|         ++MustModRefCount;
 | |
|         break;
 | |
|       }
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   // Mod/ref alias analysis: compare all pairs of calls
 | |
|   for (CallBase *CallA : Calls) {
 | |
|     for (CallBase *CallB : Calls) {
 | |
|       if (CallA == CallB)
 | |
|         continue;
 | |
|       switch (AA.getModRefInfo(CallA, CallB)) {
 | |
|       case ModRefInfo::NoModRef:
 | |
|         PrintModRefResults("NoModRef", PrintNoModRef, CallA, CallB,
 | |
|                            F.getParent());
 | |
|         ++NoModRefCount;
 | |
|         break;
 | |
|       case ModRefInfo::Mod:
 | |
|         PrintModRefResults("Just Mod", PrintMod, CallA, CallB, F.getParent());
 | |
|         ++ModCount;
 | |
|         break;
 | |
|       case ModRefInfo::Ref:
 | |
|         PrintModRefResults("Just Ref", PrintRef, CallA, CallB, F.getParent());
 | |
|         ++RefCount;
 | |
|         break;
 | |
|       case ModRefInfo::ModRef:
 | |
|         PrintModRefResults("Both ModRef", PrintModRef, CallA, CallB,
 | |
|                            F.getParent());
 | |
|         ++ModRefCount;
 | |
|         break;
 | |
|       case ModRefInfo::Must:
 | |
|         PrintModRefResults("Must", PrintMust, CallA, CallB, F.getParent());
 | |
|         ++MustCount;
 | |
|         break;
 | |
|       case ModRefInfo::MustMod:
 | |
|         PrintModRefResults("Just Mod (MustAlias)", PrintMustMod, CallA, CallB,
 | |
|                            F.getParent());
 | |
|         ++MustModCount;
 | |
|         break;
 | |
|       case ModRefInfo::MustRef:
 | |
|         PrintModRefResults("Just Ref (MustAlias)", PrintMustRef, CallA, CallB,
 | |
|                            F.getParent());
 | |
|         ++MustRefCount;
 | |
|         break;
 | |
|       case ModRefInfo::MustModRef:
 | |
|         PrintModRefResults("Both ModRef (MustAlias)", PrintMustModRef, CallA,
 | |
|                            CallB, F.getParent());
 | |
|         ++MustModRefCount;
 | |
|         break;
 | |
|       }
 | |
|     }
 | |
|   }
 | |
| }
 | |
| 
 | |
| static void PrintPercent(int64_t Num, int64_t Sum) {
 | |
|   errs() << "(" << Num * 100LL / Sum << "." << ((Num * 1000LL / Sum) % 10)
 | |
|          << "%)\n";
 | |
| }
 | |
| 
 | |
| AAEvaluator::~AAEvaluator() {
 | |
|   if (FunctionCount == 0)
 | |
|     return;
 | |
| 
 | |
|   int64_t AliasSum =
 | |
|       NoAliasCount + MayAliasCount + PartialAliasCount + MustAliasCount;
 | |
|   errs() << "===== Alias Analysis Evaluator Report =====\n";
 | |
|   if (AliasSum == 0) {
 | |
|     errs() << "  Alias Analysis Evaluator Summary: No pointers!\n";
 | |
|   } else {
 | |
|     errs() << "  " << AliasSum << " Total Alias Queries Performed\n";
 | |
|     errs() << "  " << NoAliasCount << " no alias responses ";
 | |
|     PrintPercent(NoAliasCount, AliasSum);
 | |
|     errs() << "  " << MayAliasCount << " may alias responses ";
 | |
|     PrintPercent(MayAliasCount, AliasSum);
 | |
|     errs() << "  " << PartialAliasCount << " partial alias responses ";
 | |
|     PrintPercent(PartialAliasCount, AliasSum);
 | |
|     errs() << "  " << MustAliasCount << " must alias responses ";
 | |
|     PrintPercent(MustAliasCount, AliasSum);
 | |
|     errs() << "  Alias Analysis Evaluator Pointer Alias Summary: "
 | |
|            << NoAliasCount * 100 / AliasSum << "%/"
 | |
|            << MayAliasCount * 100 / AliasSum << "%/"
 | |
|            << PartialAliasCount * 100 / AliasSum << "%/"
 | |
|            << MustAliasCount * 100 / AliasSum << "%\n";
 | |
|   }
 | |
| 
 | |
|   // Display the summary for mod/ref analysis
 | |
|   int64_t ModRefSum = NoModRefCount + RefCount + ModCount + ModRefCount +
 | |
|                       MustCount + MustRefCount + MustModCount + MustModRefCount;
 | |
|   if (ModRefSum == 0) {
 | |
|     errs() << "  Alias Analysis Mod/Ref Evaluator Summary: no "
 | |
|               "mod/ref!\n";
 | |
|   } else {
 | |
|     errs() << "  " << ModRefSum << " Total ModRef Queries Performed\n";
 | |
|     errs() << "  " << NoModRefCount << " no mod/ref responses ";
 | |
|     PrintPercent(NoModRefCount, ModRefSum);
 | |
|     errs() << "  " << ModCount << " mod responses ";
 | |
|     PrintPercent(ModCount, ModRefSum);
 | |
|     errs() << "  " << RefCount << " ref responses ";
 | |
|     PrintPercent(RefCount, ModRefSum);
 | |
|     errs() << "  " << ModRefCount << " mod & ref responses ";
 | |
|     PrintPercent(ModRefCount, ModRefSum);
 | |
|     errs() << "  " << MustCount << " must responses ";
 | |
|     PrintPercent(MustCount, ModRefSum);
 | |
|     errs() << "  " << MustModCount << " must mod responses ";
 | |
|     PrintPercent(MustModCount, ModRefSum);
 | |
|     errs() << "  " << MustRefCount << " must ref responses ";
 | |
|     PrintPercent(MustRefCount, ModRefSum);
 | |
|     errs() << "  " << MustModRefCount << " must mod & ref responses ";
 | |
|     PrintPercent(MustModRefCount, ModRefSum);
 | |
|     errs() << "  Alias Analysis Evaluator Mod/Ref Summary: "
 | |
|            << NoModRefCount * 100 / ModRefSum << "%/"
 | |
|            << ModCount * 100 / ModRefSum << "%/" << RefCount * 100 / ModRefSum
 | |
|            << "%/" << ModRefCount * 100 / ModRefSum << "%/"
 | |
|            << MustCount * 100 / ModRefSum << "%/"
 | |
|            << MustRefCount * 100 / ModRefSum << "%/"
 | |
|            << MustModCount * 100 / ModRefSum << "%/"
 | |
|            << MustModRefCount * 100 / ModRefSum << "%\n";
 | |
|   }
 | |
| }
 | |
| 
 | |
| namespace llvm {
 | |
| class AAEvalLegacyPass : public FunctionPass {
 | |
|   std::unique_ptr<AAEvaluator> P;
 | |
| 
 | |
| public:
 | |
|   static char ID; // Pass identification, replacement for typeid
 | |
|   AAEvalLegacyPass() : FunctionPass(ID) {
 | |
|     initializeAAEvalLegacyPassPass(*PassRegistry::getPassRegistry());
 | |
|   }
 | |
| 
 | |
|   void getAnalysisUsage(AnalysisUsage &AU) const override {
 | |
|     AU.addRequired<AAResultsWrapperPass>();
 | |
|     AU.setPreservesAll();
 | |
|   }
 | |
| 
 | |
|   bool doInitialization(Module &M) override {
 | |
|     P.reset(new AAEvaluator());
 | |
|     return false;
 | |
|   }
 | |
| 
 | |
|   bool runOnFunction(Function &F) override {
 | |
|     P->runInternal(F, getAnalysis<AAResultsWrapperPass>().getAAResults());
 | |
|     return false;
 | |
|   }
 | |
|   bool doFinalization(Module &M) override {
 | |
|     P.reset();
 | |
|     return false;
 | |
|   }
 | |
| };
 | |
| }
 | |
| 
 | |
| char AAEvalLegacyPass::ID = 0;
 | |
| INITIALIZE_PASS_BEGIN(AAEvalLegacyPass, "aa-eval",
 | |
|                       "Exhaustive Alias Analysis Precision Evaluator", false,
 | |
|                       true)
 | |
| INITIALIZE_PASS_DEPENDENCY(AAResultsWrapperPass)
 | |
| INITIALIZE_PASS_END(AAEvalLegacyPass, "aa-eval",
 | |
|                     "Exhaustive Alias Analysis Precision Evaluator", false,
 | |
|                     true)
 | |
| 
 | |
| FunctionPass *llvm::createAAEvalPass() { return new AAEvalLegacyPass(); }
 |