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Diffstat (limited to 'contrib/llvm/lib/Analysis/AliasAnalysisEvaluator.cpp')
-rw-r--r-- | contrib/llvm/lib/Analysis/AliasAnalysisEvaluator.cpp | 372 |
1 files changed, 372 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Analysis/AliasAnalysisEvaluator.cpp b/contrib/llvm/lib/Analysis/AliasAnalysisEvaluator.cpp new file mode 100644 index 000000000000..a571463dfe12 --- /dev/null +++ b/contrib/llvm/lib/Analysis/AliasAnalysisEvaluator.cpp @@ -0,0 +1,372 @@ +//===- 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/Assembly/Writer.h" +#include "llvm/IR/Constants.h" +#include "llvm/IR/DerivedTypes.h" +#include "llvm/IR/Function.h" +#include "llvm/IR/Instructions.h" +#include "llvm/Pass.h" +#include "llvm/Support/CommandLine.h" +#include "llvm/Support/Debug.h" +#include "llvm/Support/InstIterator.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> EvalTBAA("evaluate-tbaa", cl::ReallyHidden); + +namespace { + class AAEval : public FunctionPass { + unsigned NoAlias, MayAlias, PartialAlias, MustAlias; + unsigned NoModRef, Mod, Ref, ModRef; + + public: + static char ID; // Pass identification, replacement for typeid + AAEval() : FunctionPass(ID) { + initializeAAEvalPass(*PassRegistry::getPassRegistry()); + } + + virtual void getAnalysisUsage(AnalysisUsage &AU) const { + AU.addRequired<AliasAnalysis>(); + AU.setPreservesAll(); + } + + bool doInitialization(Module &M) { + NoAlias = MayAlias = PartialAlias = MustAlias = 0; + NoModRef = Mod = Ref = ModRef = 0; + + if (PrintAll) { + PrintNoAlias = PrintMayAlias = true; + PrintPartialAlias = PrintMustAlias = true; + PrintNoModRef = PrintMod = PrintRef = PrintModRef = true; + } + return false; + } + + bool runOnFunction(Function &F); + bool doFinalization(Module &M); + }; +} + +char AAEval::ID = 0; +INITIALIZE_PASS_BEGIN(AAEval, "aa-eval", + "Exhaustive Alias Analysis Precision Evaluator", false, true) +INITIALIZE_AG_DEPENDENCY(AliasAnalysis) +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); + WriteAsOperand(os1, V1, true, M); + WriteAsOperand(os2, V2, 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: "; + WriteAsOperand(errs(), Ptr, 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) { + AliasAnalysis &AA = getAnalysis<AliasAnalysis>(); + + SetVector<Value *> Pointers; + SetVector<CallSite> CallSites; + SetVector<Value *> Loads; + SetVector<Value *> Stores; + + for (Function::arg_iterator I = F.arg_begin(), E = F.arg_end(); I != E; ++I) + 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 (EvalTBAA && isa<LoadInst>(&*I)) + Loads.insert(&*I); + if (EvalTBAA && isa<StoreInst>(&*I)) + Stores.insert(&*I); + Instruction &Inst = *I; + if (CallSite CS = cast<Value>(&Inst)) { + Value *Callee = CS.getCalledValue(); + // Skip actual functions for direct function calls. + if (!isa<Function>(Callee) && isInterestingPointer(Callee)) + Pointers.insert(Callee); + // Consider formals. + for (CallSite::arg_iterator AI = CS.arg_begin(), AE = CS.arg_end(); + AI != AE; ++AI) + if (isInterestingPointer(*AI)) + Pointers.insert(*AI); + 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 = AliasAnalysis::UnknownSize; + Type *I1ElTy = cast<PointerType>((*I1)->getType())->getElementType(); + if (I1ElTy->isSized()) I1Size = AA.getTypeStoreSize(I1ElTy); + + for (SetVector<Value *>::iterator I2 = Pointers.begin(); I2 != I1; ++I2) { + uint64_t I2Size = AliasAnalysis::UnknownSize; + Type *I2ElTy =cast<PointerType>((*I2)->getType())->getElementType(); + if (I2ElTy->isSized()) I2Size = AA.getTypeStoreSize(I2ElTy); + + switch (AA.alias(*I1, I1Size, *I2, I2Size)) { + case AliasAnalysis::NoAlias: + PrintResults("NoAlias", PrintNoAlias, *I1, *I2, F.getParent()); + ++NoAlias; break; + case AliasAnalysis::MayAlias: + PrintResults("MayAlias", PrintMayAlias, *I1, *I2, F.getParent()); + ++MayAlias; break; + case AliasAnalysis::PartialAlias: + PrintResults("PartialAlias", PrintPartialAlias, *I1, *I2, + F.getParent()); + ++PartialAlias; break; + case AliasAnalysis::MustAlias: + PrintResults("MustAlias", PrintMustAlias, *I1, *I2, F.getParent()); + ++MustAlias; break; + } + } + } + + if (EvalTBAA) { + // 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(AA.getLocation(cast<LoadInst>(*I1)), + AA.getLocation(cast<StoreInst>(*I2)))) { + case AliasAnalysis::NoAlias: + PrintLoadStoreResults("NoAlias", PrintNoAlias, *I1, *I2, + F.getParent()); + ++NoAlias; break; + case AliasAnalysis::MayAlias: + PrintLoadStoreResults("MayAlias", PrintMayAlias, *I1, *I2, + F.getParent()); + ++MayAlias; break; + case AliasAnalysis::PartialAlias: + PrintLoadStoreResults("PartialAlias", PrintPartialAlias, *I1, *I2, + F.getParent()); + ++PartialAlias; break; + case AliasAnalysis::MustAlias: + PrintLoadStoreResults("MustAlias", PrintMustAlias, *I1, *I2, + F.getParent()); + ++MustAlias; 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(AA.getLocation(cast<StoreInst>(*I1)), + AA.getLocation(cast<StoreInst>(*I2)))) { + case AliasAnalysis::NoAlias: + PrintLoadStoreResults("NoAlias", PrintNoAlias, *I1, *I2, + F.getParent()); + ++NoAlias; break; + case AliasAnalysis::MayAlias: + PrintLoadStoreResults("MayAlias", PrintMayAlias, *I1, *I2, + F.getParent()); + ++MayAlias; break; + case AliasAnalysis::PartialAlias: + PrintLoadStoreResults("PartialAlias", PrintPartialAlias, *I1, *I2, + F.getParent()); + ++PartialAlias; break; + case AliasAnalysis::MustAlias: + PrintLoadStoreResults("MustAlias", PrintMustAlias, *I1, *I2, + F.getParent()); + ++MustAlias; break; + } + } + } + } + + // Mod/ref alias analysis: compare all pairs of calls and values + for (SetVector<CallSite>::iterator 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 = AliasAnalysis::UnknownSize; + Type *ElTy = cast<PointerType>((*V)->getType())->getElementType(); + if (ElTy->isSized()) Size = AA.getTypeStoreSize(ElTy); + + switch (AA.getModRefInfo(*C, *V, Size)) { + case AliasAnalysis::NoModRef: + PrintModRefResults("NoModRef", PrintNoModRef, I, *V, F.getParent()); + ++NoModRef; break; + case AliasAnalysis::Mod: + PrintModRefResults("Just Mod", PrintMod, I, *V, F.getParent()); + ++Mod; break; + case AliasAnalysis::Ref: + PrintModRefResults("Just Ref", PrintRef, I, *V, F.getParent()); + ++Ref; break; + case AliasAnalysis::ModRef: + PrintModRefResults("Both ModRef", PrintModRef, I, *V, F.getParent()); + ++ModRef; break; + } + } + } + + // Mod/ref alias analysis: compare all pairs of calls + for (SetVector<CallSite>::iterator C = CallSites.begin(), + Ce = CallSites.end(); C != Ce; ++C) { + for (SetVector<CallSite>::iterator D = CallSites.begin(); D != Ce; ++D) { + if (D == C) + continue; + switch (AA.getModRefInfo(*C, *D)) { + case AliasAnalysis::NoModRef: + PrintModRefResults("NoModRef", PrintNoModRef, *C, *D, F.getParent()); + ++NoModRef; break; + case AliasAnalysis::Mod: + PrintModRefResults("Just Mod", PrintMod, *C, *D, F.getParent()); + ++Mod; break; + case AliasAnalysis::Ref: + PrintModRefResults("Just Ref", PrintRef, *C, *D, F.getParent()); + ++Ref; break; + case AliasAnalysis::ModRef: + PrintModRefResults("Both ModRef", PrintModRef, *C, *D, F.getParent()); + ++ModRef; 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 = NoAlias + MayAlias + PartialAlias + MustAlias; + 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() << " " << NoAlias << " no alias responses "; + PrintPercent(NoAlias, AliasSum); + errs() << " " << MayAlias << " may alias responses "; + PrintPercent(MayAlias, AliasSum); + errs() << " " << PartialAlias << " partial alias responses "; + PrintPercent(PartialAlias, AliasSum); + errs() << " " << MustAlias << " must alias responses "; + PrintPercent(MustAlias, AliasSum); + errs() << " Alias Analysis Evaluator Pointer Alias Summary: " + << NoAlias*100/AliasSum << "%/" << MayAlias*100/AliasSum << "%/" + << PartialAlias*100/AliasSum << "%/" + << MustAlias*100/AliasSum << "%\n"; + } + + // Display the summary for mod/ref analysis + unsigned ModRefSum = NoModRef + Mod + Ref + ModRef; + if (ModRefSum == 0) { + errs() << " Alias Analysis Mod/Ref Evaluator Summary: no mod/ref!\n"; + } else { + errs() << " " << ModRefSum << " Total ModRef Queries Performed\n"; + errs() << " " << NoModRef << " no mod/ref responses "; + PrintPercent(NoModRef, ModRefSum); + errs() << " " << Mod << " mod responses "; + PrintPercent(Mod, ModRefSum); + errs() << " " << Ref << " ref responses "; + PrintPercent(Ref, ModRefSum); + errs() << " " << ModRef << " mod & ref responses "; + PrintPercent(ModRef, ModRefSum); + errs() << " Alias Analysis Evaluator Mod/Ref Summary: " + << NoModRef*100/ModRefSum << "%/" << Mod*100/ModRefSum << "%/" + << Ref*100/ModRefSum << "%/" << ModRef*100/ModRefSum << "%\n"; + } + + return false; +} |