/3rd_party/llvm/lib/Analysis/AliasAnalysisEvaluator.cpp
https://code.google.com/p/softart/ · C++ · 372 lines · 307 code · 38 blank · 27 comment · 71 complexity · 4bb6c917e64d920a956c4e38fdfa3dd9 MD5 · raw file
- //===- 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;
- }