347 lines
12 KiB
C++
347 lines
12 KiB
C++
//===--- AliasAnalysisTest.cpp - Mixed TBAA unit tests --------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/Analysis/AliasAnalysis.h"
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#include "llvm/ADT/SetVector.h"
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#include "llvm/Analysis/AssumptionCache.h"
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#include "llvm/Analysis/BasicAliasAnalysis.h"
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#include "llvm/Analysis/TargetLibraryInfo.h"
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#include "llvm/AsmParser/Parser.h"
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#include "llvm/IR/Constants.h"
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#include "llvm/IR/InstIterator.h"
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#include "llvm/IR/Instructions.h"
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#include "llvm/IR/LLVMContext.h"
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#include "llvm/IR/LegacyPassManager.h"
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#include "llvm/IR/Module.h"
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#include "llvm/InitializePasses.h"
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#include "llvm/Support/SourceMgr.h"
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#include "gtest/gtest.h"
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using namespace llvm;
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// Set up some test passes.
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namespace llvm {
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void initializeAATestPassPass(PassRegistry&);
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void initializeTestCustomAAWrapperPassPass(PassRegistry&);
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}
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namespace {
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struct AATestPass : FunctionPass {
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static char ID;
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AATestPass() : FunctionPass(ID) {
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initializeAATestPassPass(*PassRegistry::getPassRegistry());
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}
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void getAnalysisUsage(AnalysisUsage &AU) const override {
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AU.addRequired<AAResultsWrapperPass>();
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AU.setPreservesAll();
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}
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bool runOnFunction(Function &F) override {
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AliasAnalysis &AA = getAnalysis<AAResultsWrapperPass>().getAAResults();
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SetVector<Value *> Pointers;
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for (Argument &A : F.args())
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if (A.getType()->isPointerTy())
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Pointers.insert(&A);
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for (Instruction &I : instructions(F))
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if (I.getType()->isPointerTy())
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Pointers.insert(&I);
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for (Value *P1 : Pointers)
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for (Value *P2 : Pointers)
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(void)AA.alias(P1, LocationSize::beforeOrAfterPointer(), P2,
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LocationSize::beforeOrAfterPointer());
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return false;
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}
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};
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}
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char AATestPass::ID = 0;
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INITIALIZE_PASS_BEGIN(AATestPass, "aa-test-pas", "Alias Analysis Test Pass",
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false, true)
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INITIALIZE_PASS_DEPENDENCY(AAResultsWrapperPass)
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INITIALIZE_PASS_END(AATestPass, "aa-test-pass", "Alias Analysis Test Pass",
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false, true)
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namespace {
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/// A test customizable AA result. It merely accepts a callback to run whenever
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/// it receives an alias query. Useful for testing that a particular AA result
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/// is reached.
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struct TestCustomAAResult : AAResultBase<TestCustomAAResult> {
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friend AAResultBase<TestCustomAAResult>;
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std::function<void()> CB;
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explicit TestCustomAAResult(std::function<void()> CB)
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: AAResultBase(), CB(std::move(CB)) {}
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TestCustomAAResult(TestCustomAAResult &&Arg)
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: AAResultBase(std::move(Arg)), CB(std::move(Arg.CB)) {}
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bool invalidate(Function &, const PreservedAnalyses &) { return false; }
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AliasResult alias(const MemoryLocation &LocA, const MemoryLocation &LocB,
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AAQueryInfo &AAQI) {
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CB();
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return MayAlias;
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}
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};
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}
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namespace {
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/// A wrapper pass for the legacy pass manager to use with the above custom AA
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/// result.
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class TestCustomAAWrapperPass : public ImmutablePass {
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std::function<void()> CB;
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std::unique_ptr<TestCustomAAResult> Result;
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public:
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static char ID;
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explicit TestCustomAAWrapperPass(
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std::function<void()> CB = std::function<void()>())
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: ImmutablePass(ID), CB(std::move(CB)) {
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initializeTestCustomAAWrapperPassPass(*PassRegistry::getPassRegistry());
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}
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void getAnalysisUsage(AnalysisUsage &AU) const override {
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AU.setPreservesAll();
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AU.addRequired<TargetLibraryInfoWrapperPass>();
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}
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bool doInitialization(Module &M) override {
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Result.reset(new TestCustomAAResult(std::move(CB)));
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return true;
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}
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bool doFinalization(Module &M) override {
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Result.reset();
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return true;
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}
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TestCustomAAResult &getResult() { return *Result; }
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const TestCustomAAResult &getResult() const { return *Result; }
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};
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}
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char TestCustomAAWrapperPass::ID = 0;
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INITIALIZE_PASS_BEGIN(TestCustomAAWrapperPass, "test-custom-aa",
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"Test Custom AA Wrapper Pass", false, true)
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INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
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INITIALIZE_PASS_END(TestCustomAAWrapperPass, "test-custom-aa",
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"Test Custom AA Wrapper Pass", false, true)
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namespace {
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class AliasAnalysisTest : public testing::Test {
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protected:
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LLVMContext C;
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Module M;
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TargetLibraryInfoImpl TLII;
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TargetLibraryInfo TLI;
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std::unique_ptr<AssumptionCache> AC;
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std::unique_ptr<BasicAAResult> BAR;
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std::unique_ptr<AAResults> AAR;
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AliasAnalysisTest() : M("AliasAnalysisTest", C), TLI(TLII) {}
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AAResults &getAAResults(Function &F) {
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// Reset the Function AA results first to clear out any references.
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AAR.reset(new AAResults(TLI));
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// Build the various AA results and register them.
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AC.reset(new AssumptionCache(F));
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BAR.reset(new BasicAAResult(M.getDataLayout(), F, TLI, *AC));
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AAR->addAAResult(*BAR);
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return *AAR;
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}
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};
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TEST_F(AliasAnalysisTest, getModRefInfo) {
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// Setup function.
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FunctionType *FTy =
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FunctionType::get(Type::getVoidTy(C), std::vector<Type *>(), false);
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auto *F = Function::Create(FTy, Function::ExternalLinkage, "f", M);
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auto *BB = BasicBlock::Create(C, "entry", F);
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auto IntType = Type::getInt32Ty(C);
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auto PtrType = Type::getInt32PtrTy(C);
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auto *Value = ConstantInt::get(IntType, 42);
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auto *Addr = ConstantPointerNull::get(PtrType);
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auto Alignment = Align(IntType->getBitWidth() / 8);
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auto *Store1 = new StoreInst(Value, Addr, BB);
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auto *Load1 = new LoadInst(IntType, Addr, "load", BB);
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auto *Add1 = BinaryOperator::CreateAdd(Value, Value, "add", BB);
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auto *VAArg1 = new VAArgInst(Addr, PtrType, "vaarg", BB);
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auto *CmpXChg1 = new AtomicCmpXchgInst(
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Addr, ConstantInt::get(IntType, 0), ConstantInt::get(IntType, 1),
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Alignment, AtomicOrdering::Monotonic, AtomicOrdering::Monotonic,
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SyncScope::System, BB);
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auto *AtomicRMW = new AtomicRMWInst(
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AtomicRMWInst::Xchg, Addr, ConstantInt::get(IntType, 1), Alignment,
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AtomicOrdering::Monotonic, SyncScope::System, BB);
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ReturnInst::Create(C, nullptr, BB);
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auto &AA = getAAResults(*F);
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// Check basic results
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EXPECT_EQ(AA.getModRefInfo(Store1, MemoryLocation()), ModRefInfo::Mod);
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EXPECT_EQ(AA.getModRefInfo(Store1, None), ModRefInfo::Mod);
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EXPECT_EQ(AA.getModRefInfo(Load1, MemoryLocation()), ModRefInfo::Ref);
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EXPECT_EQ(AA.getModRefInfo(Load1, None), ModRefInfo::Ref);
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EXPECT_EQ(AA.getModRefInfo(Add1, MemoryLocation()), ModRefInfo::NoModRef);
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EXPECT_EQ(AA.getModRefInfo(Add1, None), ModRefInfo::NoModRef);
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EXPECT_EQ(AA.getModRefInfo(VAArg1, MemoryLocation()), ModRefInfo::ModRef);
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EXPECT_EQ(AA.getModRefInfo(VAArg1, None), ModRefInfo::ModRef);
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EXPECT_EQ(AA.getModRefInfo(CmpXChg1, MemoryLocation()), ModRefInfo::ModRef);
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EXPECT_EQ(AA.getModRefInfo(CmpXChg1, None), ModRefInfo::ModRef);
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EXPECT_EQ(AA.getModRefInfo(AtomicRMW, MemoryLocation()), ModRefInfo::ModRef);
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EXPECT_EQ(AA.getModRefInfo(AtomicRMW, None), ModRefInfo::ModRef);
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}
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static Instruction *getInstructionByName(Function &F, StringRef Name) {
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for (auto &I : instructions(F))
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if (I.getName() == Name)
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return &I;
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llvm_unreachable("Expected to find instruction!");
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}
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TEST_F(AliasAnalysisTest, BatchAAPhiCycles) {
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LLVMContext C;
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SMDiagnostic Err;
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std::unique_ptr<Module> M = parseAssemblyString(R"(
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define void @f(i8* noalias %a, i1 %c) {
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entry:
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br label %loop
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loop:
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%phi = phi i8* [ null, %entry ], [ %a2, %loop ]
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%offset1 = phi i64 [ 0, %entry ], [ %offset2, %loop]
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%offset2 = add i64 %offset1, 1
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%a1 = getelementptr i8, i8* %a, i64 %offset1
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%a2 = getelementptr i8, i8* %a, i64 %offset2
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%s1 = select i1 %c, i8* %a1, i8* %phi
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%s2 = select i1 %c, i8* %a2, i8* %a1
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br label %loop
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}
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)", Err, C);
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Function *F = M->getFunction("f");
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Instruction *Phi = getInstructionByName(*F, "phi");
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Instruction *A1 = getInstructionByName(*F, "a1");
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Instruction *A2 = getInstructionByName(*F, "a2");
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Instruction *S1 = getInstructionByName(*F, "s1");
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Instruction *S2 = getInstructionByName(*F, "s2");
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MemoryLocation PhiLoc(Phi, LocationSize::precise(1));
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MemoryLocation A1Loc(A1, LocationSize::precise(1));
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MemoryLocation A2Loc(A2, LocationSize::precise(1));
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MemoryLocation S1Loc(S1, LocationSize::precise(1));
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MemoryLocation S2Loc(S2, LocationSize::precise(1));
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auto &AA = getAAResults(*F);
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EXPECT_EQ(NoAlias, AA.alias(A1Loc, A2Loc));
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EXPECT_EQ(MayAlias, AA.alias(PhiLoc, A1Loc));
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EXPECT_EQ(MayAlias, AA.alias(S1Loc, S2Loc));
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BatchAAResults BatchAA(AA);
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EXPECT_EQ(NoAlias, BatchAA.alias(A1Loc, A2Loc));
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EXPECT_EQ(MayAlias, BatchAA.alias(PhiLoc, A1Loc));
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EXPECT_EQ(MayAlias, BatchAA.alias(S1Loc, S2Loc));
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BatchAAResults BatchAA2(AA);
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EXPECT_EQ(NoAlias, BatchAA2.alias(A1Loc, A2Loc));
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EXPECT_EQ(MayAlias, BatchAA2.alias(S1Loc, S2Loc));
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EXPECT_EQ(MayAlias, BatchAA2.alias(PhiLoc, A1Loc));
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}
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TEST_F(AliasAnalysisTest, BatchAAPhiAssumption) {
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LLVMContext C;
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SMDiagnostic Err;
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std::unique_ptr<Module> M = parseAssemblyString(R"(
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define void @f(i8* %a.base, i8* %b.base, i1 %c) {
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entry:
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br label %loop
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loop:
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%a = phi i8* [ %a.next, %loop ], [ %a.base, %entry ]
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%b = phi i8* [ %b.next, %loop ], [ %b.base, %entry ]
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%a.next = getelementptr i8, i8* %a, i64 1
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%b.next = getelementptr i8, i8* %b, i64 1
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br label %loop
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}
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)", Err, C);
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Function *F = M->getFunction("f");
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Instruction *A = getInstructionByName(*F, "a");
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Instruction *B = getInstructionByName(*F, "b");
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Instruction *ANext = getInstructionByName(*F, "a.next");
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Instruction *BNext = getInstructionByName(*F, "b.next");
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MemoryLocation ALoc(A, LocationSize::precise(1));
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MemoryLocation BLoc(B, LocationSize::precise(1));
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MemoryLocation ANextLoc(ANext, LocationSize::precise(1));
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MemoryLocation BNextLoc(BNext, LocationSize::precise(1));
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auto &AA = getAAResults(*F);
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EXPECT_EQ(MayAlias, AA.alias(ALoc, BLoc));
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EXPECT_EQ(MayAlias, AA.alias(ANextLoc, BNextLoc));
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BatchAAResults BatchAA(AA);
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EXPECT_EQ(MayAlias, BatchAA.alias(ALoc, BLoc));
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EXPECT_EQ(MayAlias, BatchAA.alias(ANextLoc, BNextLoc));
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}
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class AAPassInfraTest : public testing::Test {
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protected:
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LLVMContext C;
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SMDiagnostic Err;
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std::unique_ptr<Module> M;
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public:
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AAPassInfraTest()
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: M(parseAssemblyString("define i32 @f(i32* %x, i32* %y) {\n"
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"entry:\n"
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" %lx = load i32, i32* %x\n"
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" %ly = load i32, i32* %y\n"
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" %sum = add i32 %lx, %ly\n"
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" ret i32 %sum\n"
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"}\n",
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Err, C)) {
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assert(M && "Failed to build the module!");
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}
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};
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TEST_F(AAPassInfraTest, injectExternalAA) {
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legacy::PassManager PM;
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// Register our custom AA's wrapper pass manually.
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bool IsCustomAAQueried = false;
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PM.add(new TestCustomAAWrapperPass([&] { IsCustomAAQueried = true; }));
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// Now add the external AA wrapper with a lambda which queries for the
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// wrapper around our custom AA and adds it to the results.
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PM.add(createExternalAAWrapperPass([](Pass &P, Function &, AAResults &AAR) {
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if (auto *WrapperPass = P.getAnalysisIfAvailable<TestCustomAAWrapperPass>())
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AAR.addAAResult(WrapperPass->getResult());
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}));
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// And run a pass that will make some alias queries. This will automatically
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// trigger the rest of the alias analysis stack to be run. It is analagous to
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// building a full pass pipeline with any of the existing pass manager
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// builders.
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PM.add(new AATestPass());
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PM.run(*M);
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// Finally, ensure that our custom AA was indeed queried.
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EXPECT_TRUE(IsCustomAAQueried);
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}
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} // end anonymous namspace
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