1 //===--- AliasAnalysisTest.cpp - Mixed TBAA unit tests --------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9
10 #include "llvm/Analysis/AliasAnalysis.h"
11 #include "llvm/ADT/SetVector.h"
12 #include "llvm/Analysis/AssumptionCache.h"
13 #include "llvm/Analysis/BasicAliasAnalysis.h"
14 #include "llvm/Analysis/TargetLibraryInfo.h"
15 #include "llvm/AsmParser/Parser.h"
16 #include "llvm/IR/Constants.h"
17 #include "llvm/IR/InstIterator.h"
18 #include "llvm/IR/Instructions.h"
19 #include "llvm/IR/LLVMContext.h"
20 #include "llvm/IR/LegacyPassManager.h"
21 #include "llvm/IR/Module.h"
22 #include "llvm/Support/SourceMgr.h"
23 #include "gtest/gtest.h"
24
25 using namespace llvm;
26
27 // Set up some test passes.
28 namespace llvm {
29 void initializeAATestPassPass(PassRegistry&);
30 void initializeTestCustomAAWrapperPassPass(PassRegistry&);
31 }
32
33 namespace {
34 struct AATestPass : FunctionPass {
35 static char ID;
AATestPass__anon5d1719120111::AATestPass36 AATestPass() : FunctionPass(ID) {
37 initializeAATestPassPass(*PassRegistry::getPassRegistry());
38 }
39
getAnalysisUsage__anon5d1719120111::AATestPass40 void getAnalysisUsage(AnalysisUsage &AU) const override {
41 AU.addRequired<AAResultsWrapperPass>();
42 AU.setPreservesAll();
43 }
44
runOnFunction__anon5d1719120111::AATestPass45 bool runOnFunction(Function &F) override {
46 AliasAnalysis &AA = getAnalysis<AAResultsWrapperPass>().getAAResults();
47
48 SetVector<Value *> Pointers;
49 for (Argument &A : F.args())
50 if (A.getType()->isPointerTy())
51 Pointers.insert(&A);
52 for (Instruction &I : instructions(F))
53 if (I.getType()->isPointerTy())
54 Pointers.insert(&I);
55
56 for (Value *P1 : Pointers)
57 for (Value *P2 : Pointers)
58 (void)AA.alias(P1, MemoryLocation::UnknownSize, P2,
59 MemoryLocation::UnknownSize);
60
61 return false;
62 }
63 };
64 }
65
66 char AATestPass::ID = 0;
67 INITIALIZE_PASS_BEGIN(AATestPass, "aa-test-pas", "Alias Analysis Test Pass",
68 false, true)
69 INITIALIZE_PASS_DEPENDENCY(AAResultsWrapperPass)
70 INITIALIZE_PASS_END(AATestPass, "aa-test-pass", "Alias Analysis Test Pass",
71 false, true)
72
73 namespace {
74 /// A test customizable AA result. It merely accepts a callback to run whenever
75 /// it receives an alias query. Useful for testing that a particular AA result
76 /// is reached.
77 struct TestCustomAAResult : AAResultBase<TestCustomAAResult> {
78 friend AAResultBase<TestCustomAAResult>;
79
80 std::function<void()> CB;
81
TestCustomAAResult__anon5d1719120211::TestCustomAAResult82 explicit TestCustomAAResult(std::function<void()> CB)
83 : AAResultBase(), CB(std::move(CB)) {}
TestCustomAAResult__anon5d1719120211::TestCustomAAResult84 TestCustomAAResult(TestCustomAAResult &&Arg)
85 : AAResultBase(std::move(Arg)), CB(std::move(Arg.CB)) {}
86
invalidate__anon5d1719120211::TestCustomAAResult87 bool invalidate(Function &, const PreservedAnalyses &) { return false; }
88
alias__anon5d1719120211::TestCustomAAResult89 AliasResult alias(const MemoryLocation &LocA, const MemoryLocation &LocB) {
90 CB();
91 return MayAlias;
92 }
93 };
94 }
95
96 namespace {
97 /// A wrapper pass for the legacy pass manager to use with the above custom AA
98 /// result.
99 class TestCustomAAWrapperPass : public ImmutablePass {
100 std::function<void()> CB;
101 std::unique_ptr<TestCustomAAResult> Result;
102
103 public:
104 static char ID;
105
TestCustomAAWrapperPass(std::function<void ()> CB=std::function<void ()> ())106 explicit TestCustomAAWrapperPass(
107 std::function<void()> CB = std::function<void()>())
108 : ImmutablePass(ID), CB(std::move(CB)) {
109 initializeTestCustomAAWrapperPassPass(*PassRegistry::getPassRegistry());
110 }
111
getAnalysisUsage(AnalysisUsage & AU) const112 void getAnalysisUsage(AnalysisUsage &AU) const override {
113 AU.setPreservesAll();
114 AU.addRequired<TargetLibraryInfoWrapperPass>();
115 }
116
doInitialization(Module & M)117 bool doInitialization(Module &M) override {
118 Result.reset(new TestCustomAAResult(std::move(CB)));
119 return true;
120 }
121
doFinalization(Module & M)122 bool doFinalization(Module &M) override {
123 Result.reset();
124 return true;
125 }
126
getResult()127 TestCustomAAResult &getResult() { return *Result; }
getResult() const128 const TestCustomAAResult &getResult() const { return *Result; }
129 };
130 }
131
132 char TestCustomAAWrapperPass::ID = 0;
133 INITIALIZE_PASS_BEGIN(TestCustomAAWrapperPass, "test-custom-aa",
134 "Test Custom AA Wrapper Pass", false, true)
135 INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
136 INITIALIZE_PASS_END(TestCustomAAWrapperPass, "test-custom-aa",
137 "Test Custom AA Wrapper Pass", false, true)
138
139 namespace {
140
141 class AliasAnalysisTest : public testing::Test {
142 protected:
143 LLVMContext C;
144 Module M;
145 TargetLibraryInfoImpl TLII;
146 TargetLibraryInfo TLI;
147 std::unique_ptr<AssumptionCache> AC;
148 std::unique_ptr<BasicAAResult> BAR;
149 std::unique_ptr<AAResults> AAR;
150
AliasAnalysisTest()151 AliasAnalysisTest() : M("AliasAnalysisTest", C), TLI(TLII) {}
152
getAAResults(Function & F)153 AAResults &getAAResults(Function &F) {
154 // Reset the Function AA results first to clear out any references.
155 AAR.reset(new AAResults(TLI));
156
157 // Build the various AA results and register them.
158 AC.reset(new AssumptionCache(F));
159 BAR.reset(new BasicAAResult(M.getDataLayout(), F, TLI, *AC));
160 AAR->addAAResult(*BAR);
161
162 return *AAR;
163 }
164 };
165
TEST_F(AliasAnalysisTest,getModRefInfo)166 TEST_F(AliasAnalysisTest, getModRefInfo) {
167 // Setup function.
168 FunctionType *FTy =
169 FunctionType::get(Type::getVoidTy(C), std::vector<Type *>(), false);
170 auto *F = cast<Function>(M.getOrInsertFunction("f", FTy));
171 auto *BB = BasicBlock::Create(C, "entry", F);
172 auto IntType = Type::getInt32Ty(C);
173 auto PtrType = Type::getInt32PtrTy(C);
174 auto *Value = ConstantInt::get(IntType, 42);
175 auto *Addr = ConstantPointerNull::get(PtrType);
176
177 auto *Store1 = new StoreInst(Value, Addr, BB);
178 auto *Load1 = new LoadInst(Addr, "load", BB);
179 auto *Add1 = BinaryOperator::CreateAdd(Value, Value, "add", BB);
180 auto *VAArg1 = new VAArgInst(Addr, PtrType, "vaarg", BB);
181 auto *CmpXChg1 = new AtomicCmpXchgInst(
182 Addr, ConstantInt::get(IntType, 0), ConstantInt::get(IntType, 1),
183 AtomicOrdering::Monotonic, AtomicOrdering::Monotonic,
184 SyncScope::System, BB);
185 auto *AtomicRMW =
186 new AtomicRMWInst(AtomicRMWInst::Xchg, Addr, ConstantInt::get(IntType, 1),
187 AtomicOrdering::Monotonic, SyncScope::System, BB);
188
189 ReturnInst::Create(C, nullptr, BB);
190
191 auto &AA = getAAResults(*F);
192
193 // Check basic results
194 EXPECT_EQ(AA.getModRefInfo(Store1, MemoryLocation()), ModRefInfo::Mod);
195 EXPECT_EQ(AA.getModRefInfo(Store1, None), ModRefInfo::Mod);
196 EXPECT_EQ(AA.getModRefInfo(Load1, MemoryLocation()), ModRefInfo::Ref);
197 EXPECT_EQ(AA.getModRefInfo(Load1, None), ModRefInfo::Ref);
198 EXPECT_EQ(AA.getModRefInfo(Add1, MemoryLocation()), ModRefInfo::NoModRef);
199 EXPECT_EQ(AA.getModRefInfo(Add1, None), ModRefInfo::NoModRef);
200 EXPECT_EQ(AA.getModRefInfo(VAArg1, MemoryLocation()), ModRefInfo::ModRef);
201 EXPECT_EQ(AA.getModRefInfo(VAArg1, None), ModRefInfo::ModRef);
202 EXPECT_EQ(AA.getModRefInfo(CmpXChg1, MemoryLocation()), ModRefInfo::ModRef);
203 EXPECT_EQ(AA.getModRefInfo(CmpXChg1, None), ModRefInfo::ModRef);
204 EXPECT_EQ(AA.getModRefInfo(AtomicRMW, MemoryLocation()), ModRefInfo::ModRef);
205 EXPECT_EQ(AA.getModRefInfo(AtomicRMW, None), ModRefInfo::ModRef);
206 }
207
208 class AAPassInfraTest : public testing::Test {
209 protected:
210 LLVMContext C;
211 SMDiagnostic Err;
212 std::unique_ptr<Module> M;
213
214 public:
AAPassInfraTest()215 AAPassInfraTest()
216 : M(parseAssemblyString("define i32 @f(i32* %x, i32* %y) {\n"
217 "entry:\n"
218 " %lx = load i32, i32* %x\n"
219 " %ly = load i32, i32* %y\n"
220 " %sum = add i32 %lx, %ly\n"
221 " ret i32 %sum\n"
222 "}\n",
223 Err, C)) {
224 assert(M && "Failed to build the module!");
225 }
226 };
227
TEST_F(AAPassInfraTest,injectExternalAA)228 TEST_F(AAPassInfraTest, injectExternalAA) {
229 legacy::PassManager PM;
230
231 // Register our custom AA's wrapper pass manually.
232 bool IsCustomAAQueried = false;
233 PM.add(new TestCustomAAWrapperPass([&] { IsCustomAAQueried = true; }));
234
235 // Now add the external AA wrapper with a lambda which queries for the
236 // wrapper around our custom AA and adds it to the results.
237 PM.add(createExternalAAWrapperPass([](Pass &P, Function &, AAResults &AAR) {
238 if (auto *WrapperPass = P.getAnalysisIfAvailable<TestCustomAAWrapperPass>())
239 AAR.addAAResult(WrapperPass->getResult());
240 }));
241
242 // And run a pass that will make some alias queries. This will automatically
243 // trigger the rest of the alias analysis stack to be run. It is analagous to
244 // building a full pass pipeline with any of the existing pass manager
245 // builders.
246 PM.add(new AATestPass());
247 PM.run(*M);
248
249 // Finally, ensure that our custom AA was indeed queried.
250 EXPECT_TRUE(IsCustomAAQueried);
251 }
252
253 } // end anonymous namspace
254