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Diffstat (limited to 'contrib/llvm/lib/Analysis/AliasAnalysisEvaluator.cpp')
| -rw-r--r-- | contrib/llvm/lib/Analysis/AliasAnalysisEvaluator.cpp | 395 |
1 files changed, 395 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Analysis/AliasAnalysisEvaluator.cpp b/contrib/llvm/lib/Analysis/AliasAnalysisEvaluator.cpp new file mode 100644 index 0000000..12917b6 --- /dev/null +++ b/contrib/llvm/lib/Analysis/AliasAnalysisEvaluator.cpp @@ -0,0 +1,395 @@ +//===- AliasAnalysisEvaluator.cpp - Alias Analysis Accuracy Evaluator -----===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file implements a simple N^2 alias analysis accuracy evaluator. +// Basically, for each function in the program, it simply queries to see how the +// alias analysis implementation answers alias queries between each pair of +// pointers in the function. +// +// This is inspired and adapted from code by: Naveen Neelakantam, Francesco +// Spadini, and Wojciech Stryjewski. +// +//===----------------------------------------------------------------------===// + +#include "llvm/Analysis/Passes.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/Module.h" +#include "llvm/IR/InstIterator.h" +#include "llvm/IR/Instructions.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> PrintMod("print-mod", cl::ReallyHidden); +static cl::opt<bool> PrintRef("print-ref", cl::ReallyHidden); +static cl::opt<bool> PrintModRef("print-modref", cl::ReallyHidden); + +static cl::opt<bool> EvalAAMD("evaluate-aa-metadata", cl::ReallyHidden); + +namespace { + class AAEval : public FunctionPass { + unsigned NoAliasCount, MayAliasCount, PartialAliasCount, MustAliasCount; + unsigned NoModRefCount, ModCount, RefCount, ModRefCount; + + public: + static char ID; // Pass identification, replacement for typeid + AAEval() : FunctionPass(ID) { + initializeAAEvalPass(*PassRegistry::getPassRegistry()); + } + + void getAnalysisUsage(AnalysisUsage &AU) const override { + AU.addRequired<AAResultsWrapperPass>(); + AU.setPreservesAll(); + } + + bool doInitialization(Module &M) override { + NoAliasCount = MayAliasCount = PartialAliasCount = MustAliasCount = 0; + NoModRefCount = ModCount = RefCount = ModRefCount = 0; + + if (PrintAll) { + PrintNoAlias = PrintMayAlias = true; + PrintPartialAlias = PrintMustAlias = true; + PrintNoModRef = PrintMod = PrintRef = PrintModRef = true; + } + return false; + } + + bool runOnFunction(Function &F) override; + bool doFinalization(Module &M) override; + }; +} + +char AAEval::ID = 0; +INITIALIZE_PASS_BEGIN(AAEval, "aa-eval", + "Exhaustive Alias Analysis Precision Evaluator", false, true) +INITIALIZE_PASS_DEPENDENCY(AAResultsWrapperPass) +INITIALIZE_PASS_END(AAEval, "aa-eval", + "Exhaustive Alias Analysis Precision Evaluator", false, true) + +FunctionPass *llvm::createAAEvalPass() { return new AAEval(); } + +static void PrintResults(const char *Msg, bool P, const Value *V1, + const Value *V2, const Module *M) { + if (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() << " " << Msg << ":\t" + << o1 << ", " + << o2 << "\n"; + } +} + +static inline void +PrintModRefResults(const char *Msg, bool P, Instruction *I, Value *Ptr, + Module *M) { + if (P) { + errs() << " " << Msg << ": Ptr: "; + Ptr->printAsOperand(errs(), true, M); + errs() << "\t<->" << *I << '\n'; + } +} + +static inline void +PrintModRefResults(const char *Msg, bool P, CallSite CSA, CallSite CSB, + Module *M) { + if (P) { + errs() << " " << Msg << ": " << *CSA.getInstruction() + << " <-> " << *CSB.getInstruction() << '\n'; + } +} + +static inline void +PrintLoadStoreResults(const char *Msg, bool P, const Value *V1, + const Value *V2, const Module *M) { + if (P) { + errs() << " " << Msg << ": " << *V1 + << " <-> " << *V2 << '\n'; + } +} + +static inline bool isInterestingPointer(Value *V) { + return V->getType()->isPointerTy() + && !isa<ConstantPointerNull>(V); +} + +bool AAEval::runOnFunction(Function &F) { + const DataLayout &DL = F.getParent()->getDataLayout(); + AliasAnalysis &AA = getAnalysis<AAResultsWrapperPass>().getAAResults(); + + SetVector<Value *> Pointers; + SmallSetVector<CallSite, 16> CallSites; + 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 CS = CallSite(&Inst)) { + Value *Callee = CS.getCalledValue(); + // Skip actual functions for direct function calls. + if (!isa<Function>(Callee) && isInterestingPointer(Callee)) + Pointers.insert(Callee); + // Consider formals. + for (Use &DataOp : CS.data_ops()) + if (isInterestingPointer(DataOp)) + Pointers.insert(DataOp); + CallSites.insert(CS); + } 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 (PrintNoAlias || PrintMayAlias || PrintPartialAlias || PrintMustAlias || + PrintNoModRef || PrintMod || PrintRef || PrintModRef) + errs() << "Function: " << F.getName() << ": " << Pointers.size() + << " pointers, " << CallSites.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) { + uint64_t I1Size = MemoryLocation::UnknownSize; + Type *I1ElTy = cast<PointerType>((*I1)->getType())->getElementType(); + if (I1ElTy->isSized()) I1Size = DL.getTypeStoreSize(I1ElTy); + + for (SetVector<Value *>::iterator I2 = Pointers.begin(); I2 != I1; ++I2) { + uint64_t I2Size = MemoryLocation::UnknownSize; + Type *I2ElTy =cast<PointerType>((*I2)->getType())->getElementType(); + if (I2ElTy->isSized()) I2Size = DL.getTypeStoreSize(I2ElTy); + + switch (AA.alias(*I1, I1Size, *I2, I2Size)) { + case NoAlias: + PrintResults("NoAlias", PrintNoAlias, *I1, *I2, F.getParent()); + ++NoAliasCount; + break; + case MayAlias: + PrintResults("MayAlias", PrintMayAlias, *I1, *I2, F.getParent()); + ++MayAliasCount; + break; + case PartialAlias: + PrintResults("PartialAlias", PrintPartialAlias, *I1, *I2, + F.getParent()); + ++PartialAliasCount; + break; + case MustAlias: + PrintResults("MustAlias", PrintMustAlias, *I1, *I2, F.getParent()); + ++MustAliasCount; + break; + } + } + } + + if (EvalAAMD) { + // iterate over all pairs of load, store + for (SetVector<Value *>::iterator I1 = Loads.begin(), E = Loads.end(); + I1 != E; ++I1) { + for (SetVector<Value *>::iterator I2 = Stores.begin(), E2 = Stores.end(); + I2 != E2; ++I2) { + switch (AA.alias(MemoryLocation::get(cast<LoadInst>(*I1)), + MemoryLocation::get(cast<StoreInst>(*I2)))) { + case NoAlias: + PrintLoadStoreResults("NoAlias", PrintNoAlias, *I1, *I2, + F.getParent()); + ++NoAliasCount; + break; + case MayAlias: + PrintLoadStoreResults("MayAlias", PrintMayAlias, *I1, *I2, + F.getParent()); + ++MayAliasCount; + break; + case PartialAlias: + PrintLoadStoreResults("PartialAlias", PrintPartialAlias, *I1, *I2, + F.getParent()); + ++PartialAliasCount; + break; + case MustAlias: + PrintLoadStoreResults("MustAlias", PrintMustAlias, *I1, *I2, + 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) { + switch (AA.alias(MemoryLocation::get(cast<StoreInst>(*I1)), + MemoryLocation::get(cast<StoreInst>(*I2)))) { + case NoAlias: + PrintLoadStoreResults("NoAlias", PrintNoAlias, *I1, *I2, + F.getParent()); + ++NoAliasCount; + break; + case MayAlias: + PrintLoadStoreResults("MayAlias", PrintMayAlias, *I1, *I2, + F.getParent()); + ++MayAliasCount; + break; + case PartialAlias: + PrintLoadStoreResults("PartialAlias", PrintPartialAlias, *I1, *I2, + F.getParent()); + ++PartialAliasCount; + break; + case MustAlias: + PrintLoadStoreResults("MustAlias", PrintMustAlias, *I1, *I2, + F.getParent()); + ++MustAliasCount; + break; + } + } + } + } + + // Mod/ref alias analysis: compare all pairs of calls and values + for (auto C = CallSites.begin(), Ce = CallSites.end(); C != Ce; ++C) { + Instruction *I = C->getInstruction(); + + for (SetVector<Value *>::iterator V = Pointers.begin(), Ve = Pointers.end(); + V != Ve; ++V) { + uint64_t Size = MemoryLocation::UnknownSize; + Type *ElTy = cast<PointerType>((*V)->getType())->getElementType(); + if (ElTy->isSized()) Size = DL.getTypeStoreSize(ElTy); + + switch (AA.getModRefInfo(*C, *V, Size)) { + case MRI_NoModRef: + PrintModRefResults("NoModRef", PrintNoModRef, I, *V, F.getParent()); + ++NoModRefCount; + break; + case MRI_Mod: + PrintModRefResults("Just Mod", PrintMod, I, *V, F.getParent()); + ++ModCount; + break; + case MRI_Ref: + PrintModRefResults("Just Ref", PrintRef, I, *V, F.getParent()); + ++RefCount; + break; + case MRI_ModRef: + PrintModRefResults("Both ModRef", PrintModRef, I, *V, F.getParent()); + ++ModRefCount; + break; + } + } + } + + // Mod/ref alias analysis: compare all pairs of calls + for (auto C = CallSites.begin(), Ce = CallSites.end(); C != Ce; ++C) { + for (auto D = CallSites.begin(); D != Ce; ++D) { + if (D == C) + continue; + switch (AA.getModRefInfo(*C, *D)) { + case MRI_NoModRef: + PrintModRefResults("NoModRef", PrintNoModRef, *C, *D, F.getParent()); + ++NoModRefCount; + break; + case MRI_Mod: + PrintModRefResults("Just Mod", PrintMod, *C, *D, F.getParent()); + ++ModCount; + break; + case MRI_Ref: + PrintModRefResults("Just Ref", PrintRef, *C, *D, F.getParent()); + ++RefCount; + break; + case MRI_ModRef: + PrintModRefResults("Both ModRef", PrintModRef, *C, *D, F.getParent()); + ++ModRefCount; + break; + } + } + } + + return false; +} + +static void PrintPercent(unsigned Num, unsigned Sum) { + errs() << "(" << Num*100ULL/Sum << "." + << ((Num*1000ULL/Sum) % 10) << "%)\n"; +} + +bool AAEval::doFinalization(Module &M) { + unsigned 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 + unsigned ModRefSum = NoModRefCount + ModCount + RefCount + ModRefCount; + 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() << " Alias Analysis Evaluator Mod/Ref Summary: " + << NoModRefCount * 100 / ModRefSum << "%/" + << ModCount * 100 / ModRefSum << "%/" << RefCount * 100 / ModRefSum + << "%/" << ModRefCount * 100 / ModRefSum << "%\n"; + } + + return false; +} |
