xref: /llvm-project/llvm/unittests/Transforms/Utils/ValueMapperTest.cpp (revision 11f60fd65a79350de1e9f295ea2c997bdc534ea9)
1 //===- ValueMapper.cpp - Unit tests for ValueMapper -----------------------===//
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/IR/Constants.h"
11 #include "llvm/IR/Function.h"
12 #include "llvm/IR/GlobalVariable.h"
13 #include "llvm/IR/LLVMContext.h"
14 #include "llvm/IR/Metadata.h"
15 #include "llvm/Transforms/Utils/ValueMapper.h"
16 #include "gtest/gtest.h"
17 
18 using namespace llvm;
19 
20 namespace {
21 
22 TEST(ValueMapperTest, MapMetadata) {
23   LLVMContext Context;
24   auto *U = MDTuple::get(Context, None);
25 
26   // The node should be unchanged.
27   ValueToValueMapTy VM;
28   EXPECT_EQ(U, MapMetadata(U, VM, RF_None));
29 }
30 
31 TEST(ValueMapperTest, MapMetadataCycle) {
32   LLVMContext Context;
33   MDNode *U0;
34   MDNode *U1;
35   {
36     Metadata *Ops[] = {nullptr};
37     auto T = MDTuple::getTemporary(Context, Ops);
38     Ops[0] = T.get();
39     U0 = MDTuple::get(Context, Ops);
40     T->replaceOperandWith(0, U0);
41     U1 = MDNode::replaceWithUniqued(std::move(T));
42     U0->resolveCycles();
43   }
44 
45   EXPECT_TRUE(U0->isResolved());
46   EXPECT_TRUE(U0->isUniqued());
47   EXPECT_TRUE(U1->isResolved());
48   EXPECT_TRUE(U1->isUniqued());
49   EXPECT_EQ(U1, U0->getOperand(0));
50   EXPECT_EQ(U0, U1->getOperand(0));
51 
52   // Cycles shouldn't be duplicated.
53   {
54     ValueToValueMapTy VM;
55     EXPECT_EQ(U0, MapMetadata(U0, VM, RF_None));
56     EXPECT_EQ(U1, MapMetadata(U1, VM, RF_None));
57   }
58 
59   // Check the other order.
60   {
61     ValueToValueMapTy VM;
62     EXPECT_EQ(U1, MapMetadata(U1, VM, RF_None));
63     EXPECT_EQ(U0, MapMetadata(U0, VM, RF_None));
64   }
65 }
66 
67 TEST(ValueMapperTest, MapMetadataDuplicatedCycle) {
68   LLVMContext Context;
69   auto *PtrTy = Type::getInt8Ty(Context)->getPointerTo();
70   std::unique_ptr<GlobalVariable> G0 = llvm::make_unique<GlobalVariable>(
71       PtrTy, false, GlobalValue::ExternalLinkage, nullptr, "G0");
72   std::unique_ptr<GlobalVariable> G1 = llvm::make_unique<GlobalVariable>(
73       PtrTy, false, GlobalValue::ExternalLinkage, nullptr, "G1");
74 
75   // Create a cycle that references G0.
76   MDNode *N0; // !0 = !{!1}
77   MDNode *N1; // !1 = !{!0, i8* @G0}
78   {
79     auto T0 = MDTuple::getTemporary(Context, nullptr);
80     Metadata *Ops1[] = {T0.get(), ConstantAsMetadata::get(G0.get())};
81     N1 = MDTuple::get(Context, Ops1);
82     T0->replaceOperandWith(0, N1);
83     N0 = MDNode::replaceWithUniqued(std::move(T0));
84   }
85 
86   // Resolve N0 and N1.
87   ASSERT_FALSE(N0->isResolved());
88   ASSERT_FALSE(N1->isResolved());
89   N0->resolveCycles();
90   ASSERT_TRUE(N0->isResolved());
91   ASSERT_TRUE(N1->isResolved());
92 
93   // Seed the value map to map G0 to G1 and map the nodes.  The output should
94   // have new nodes that reference G1 (instead of G0).
95   ValueToValueMapTy VM;
96   VM[G0.get()] = G1.get();
97   MDNode *MappedN0 = MapMetadata(N0, VM);
98   MDNode *MappedN1 = MapMetadata(N1, VM);
99   EXPECT_NE(N0, MappedN0);
100   EXPECT_NE(N1, MappedN1);
101   EXPECT_EQ(ConstantAsMetadata::get(G1.get()), MappedN1->getOperand(1));
102 
103   // Check that the output nodes are resolved.
104   EXPECT_TRUE(MappedN0->isResolved());
105   EXPECT_TRUE(MappedN1->isResolved());
106 }
107 
108 TEST(ValueMapperTest, MapMetadataUnresolved) {
109   LLVMContext Context;
110   TempMDTuple T = MDTuple::getTemporary(Context, None);
111 
112   ValueToValueMapTy VM;
113   EXPECT_EQ(T.get(), MapMetadata(T.get(), VM, RF_NoModuleLevelChanges));
114 }
115 
116 TEST(ValueMapperTest, MapMetadataDistinct) {
117   LLVMContext Context;
118   auto *D = MDTuple::getDistinct(Context, None);
119 
120   {
121     // The node should be cloned.
122     ValueToValueMapTy VM;
123     EXPECT_NE(D, MapMetadata(D, VM, RF_None));
124   }
125   {
126     // The node should be moved.
127     ValueToValueMapTy VM;
128     EXPECT_EQ(D, MapMetadata(D, VM, RF_MoveDistinctMDs));
129   }
130 }
131 
132 TEST(ValueMapperTest, MapMetadataDistinctOperands) {
133   LLVMContext Context;
134   Metadata *Old = MDTuple::getDistinct(Context, None);
135   auto *D = MDTuple::getDistinct(Context, Old);
136   ASSERT_EQ(Old, D->getOperand(0));
137 
138   Metadata *New = MDTuple::getDistinct(Context, None);
139   ValueToValueMapTy VM;
140   VM.MD()[Old].reset(New);
141 
142   // Make sure operands are updated.
143   EXPECT_EQ(D, MapMetadata(D, VM, RF_MoveDistinctMDs));
144   EXPECT_EQ(New, D->getOperand(0));
145 }
146 
147 TEST(ValueMapperTest, MapMetadataSeeded) {
148   LLVMContext Context;
149   auto *D = MDTuple::getDistinct(Context, None);
150 
151   // The node should be moved.
152   ValueToValueMapTy VM;
153   EXPECT_EQ(None, VM.getMappedMD(D));
154 
155   VM.MD().insert(std::make_pair(D, TrackingMDRef(D)));
156   EXPECT_EQ(D, *VM.getMappedMD(D));
157   EXPECT_EQ(D, MapMetadata(D, VM, RF_None));
158 }
159 
160 TEST(ValueMapperTest, MapMetadataSeededWithNull) {
161   LLVMContext Context;
162   auto *D = MDTuple::getDistinct(Context, None);
163 
164   // The node should be moved.
165   ValueToValueMapTy VM;
166   EXPECT_EQ(None, VM.getMappedMD(D));
167 
168   VM.MD().insert(std::make_pair(D, TrackingMDRef()));
169   EXPECT_EQ(nullptr, *VM.getMappedMD(D));
170   EXPECT_EQ(nullptr, MapMetadata(D, VM, RF_None));
171 }
172 
173 TEST(ValueMapperTest, MapMetadataNullMapGlobalWithIgnoreMissingLocals) {
174   LLVMContext C;
175   FunctionType *FTy =
176       FunctionType::get(Type::getVoidTy(C), Type::getInt8Ty(C), false);
177   std::unique_ptr<Function> F(
178       Function::Create(FTy, GlobalValue::ExternalLinkage, "F"));
179 
180   ValueToValueMapTy VM;
181   RemapFlags Flags = RF_IgnoreMissingLocals | RF_NullMapMissingGlobalValues;
182   EXPECT_EQ(nullptr, MapValue(F.get(), VM, Flags));
183 }
184 
185 TEST(ValueMapperTest, MapMetadataMDString) {
186   LLVMContext C;
187   auto *S1 = MDString::get(C, "S1");
188   ValueToValueMapTy VM;
189 
190   // Make sure S1 maps to itself, but isn't memoized.
191   EXPECT_EQ(S1, MapMetadata(S1, VM));
192   EXPECT_EQ(None, VM.getMappedMD(S1));
193 
194   // We still expect VM.MD() to be respected.
195   auto *S2 = MDString::get(C, "S2");
196   VM.MD()[S1].reset(S2);
197   EXPECT_EQ(S2, MapMetadata(S1, VM));
198 }
199 
200 TEST(ValueMapperTest, MapMetadataGetMappedMD) {
201   LLVMContext C;
202   auto *N0 = MDTuple::get(C, None);
203   auto *N1 = MDTuple::get(C, N0);
204 
205   // Make sure hasMD and getMappedMD work correctly.
206   ValueToValueMapTy VM;
207   EXPECT_FALSE(VM.hasMD());
208   EXPECT_EQ(N0, MapMetadata(N0, VM));
209   EXPECT_EQ(N1, MapMetadata(N1, VM));
210   EXPECT_TRUE(VM.hasMD());
211   ASSERT_NE(None, VM.getMappedMD(N0));
212   ASSERT_NE(None, VM.getMappedMD(N1));
213   EXPECT_EQ(N0, *VM.getMappedMD(N0));
214   EXPECT_EQ(N1, *VM.getMappedMD(N1));
215 }
216 
217 TEST(ValueMapperTest, MapMetadataNoModuleLevelChanges) {
218   LLVMContext C;
219   auto *N0 = MDTuple::get(C, None);
220   auto *N1 = MDTuple::get(C, N0);
221 
222   // Nothing should be memoized when RF_NoModuleLevelChanges.
223   ValueToValueMapTy VM;
224   EXPECT_FALSE(VM.hasMD());
225   EXPECT_EQ(N0, MapMetadata(N0, VM, RF_NoModuleLevelChanges));
226   EXPECT_EQ(N1, MapMetadata(N1, VM, RF_NoModuleLevelChanges));
227   EXPECT_FALSE(VM.hasMD());
228   EXPECT_EQ(None, VM.getMappedMD(N0));
229   EXPECT_EQ(None, VM.getMappedMD(N1));
230 }
231 
232 TEST(ValueMapperTest, MapMetadataConstantAsMetadata) {
233   LLVMContext C;
234   FunctionType *FTy =
235       FunctionType::get(Type::getVoidTy(C), Type::getInt8Ty(C), false);
236   std::unique_ptr<Function> F(
237       Function::Create(FTy, GlobalValue::ExternalLinkage, "F"));
238 
239   auto *CAM = ConstantAsMetadata::get(F.get());
240   {
241     ValueToValueMapTy VM;
242     EXPECT_EQ(CAM, MapMetadata(CAM, VM));
243     EXPECT_TRUE(VM.MD().count(CAM));
244     VM.MD().erase(CAM);
245     EXPECT_EQ(CAM, MapMetadata(CAM, VM, RF_IgnoreMissingLocals));
246     EXPECT_TRUE(VM.MD().count(CAM));
247 
248     auto *N = MDTuple::get(C, None);
249     VM.MD()[CAM].reset(N);
250     EXPECT_EQ(N, MapMetadata(CAM, VM));
251     EXPECT_EQ(N, MapMetadata(CAM, VM, RF_IgnoreMissingLocals));
252   }
253 
254   std::unique_ptr<Function> F2(
255       Function::Create(FTy, GlobalValue::ExternalLinkage, "F2"));
256   ValueToValueMapTy VM;
257   VM[F.get()] = F2.get();
258   auto *F2MD = MapMetadata(CAM, VM);
259   EXPECT_TRUE(VM.MD().count(CAM));
260   EXPECT_TRUE(F2MD);
261   EXPECT_EQ(F2.get(), cast<ConstantAsMetadata>(F2MD)->getValue());
262 }
263 
264 #ifdef GTEST_HAS_DEATH_TEST
265 #ifndef NDEBUG
266 TEST(ValueMapperTest, MapMetadataLocalAsMetadata) {
267   LLVMContext C;
268   FunctionType *FTy =
269       FunctionType::get(Type::getVoidTy(C), Type::getInt8Ty(C), false);
270   std::unique_ptr<Function> F(
271       Function::Create(FTy, GlobalValue::ExternalLinkage, "F"));
272   Argument &A = *F->arg_begin();
273 
274   // MapMetadata doesn't support LocalAsMetadata.  The only valid container for
275   // LocalAsMetadata is a MetadataAsValue instance, so use it directly.
276   auto *LAM = LocalAsMetadata::get(&A);
277   ValueToValueMapTy VM;
278   EXPECT_DEATH(MapMetadata(LAM, VM), "Unexpected local metadata");
279   EXPECT_DEATH(MapMetadata(LAM, VM, RF_IgnoreMissingLocals),
280                "Unexpected local metadata");
281 }
282 #endif
283 #endif
284 
285 TEST(ValueMapperTest, MapValueLocalAsMetadata) {
286   LLVMContext C;
287   FunctionType *FTy =
288       FunctionType::get(Type::getVoidTy(C), Type::getInt8Ty(C), false);
289   std::unique_ptr<Function> F(
290       Function::Create(FTy, GlobalValue::ExternalLinkage, "F"));
291   Argument &A = *F->arg_begin();
292 
293   auto *LAM = LocalAsMetadata::get(&A);
294   auto *MAV = MetadataAsValue::get(C, LAM);
295 
296   // The principled answer to a LocalAsMetadata of an unmapped SSA value would
297   // be to return nullptr (regardless of RF_IgnoreMissingLocals).
298   //
299   // However, algorithms that use RemapInstruction assume that each instruction
300   // only references SSA values from previous instructions.  Arguments of
301   // such as "metadata i32 %x" don't currently successfully maintain that
302   // property.  To keep RemapInstruction from crashing we need a non-null
303   // return here, but we also shouldn't reference the unmapped local.  Use
304   // "metadata !{}".
305   auto *N0 = MDTuple::get(C, None);
306   auto *N0AV = MetadataAsValue::get(C, N0);
307   ValueToValueMapTy VM;
308   EXPECT_EQ(N0AV, MapValue(MAV, VM));
309   EXPECT_EQ(nullptr, MapValue(MAV, VM, RF_IgnoreMissingLocals));
310   EXPECT_FALSE(VM.count(MAV));
311   EXPECT_FALSE(VM.count(&A));
312   EXPECT_EQ(None, VM.getMappedMD(LAM));
313 
314   VM[MAV] = MAV;
315   EXPECT_EQ(MAV, MapValue(MAV, VM));
316   EXPECT_EQ(MAV, MapValue(MAV, VM, RF_IgnoreMissingLocals));
317   EXPECT_TRUE(VM.count(MAV));
318   EXPECT_FALSE(VM.count(&A));
319 
320   VM[MAV] = &A;
321   EXPECT_EQ(&A, MapValue(MAV, VM));
322   EXPECT_EQ(&A, MapValue(MAV, VM, RF_IgnoreMissingLocals));
323   EXPECT_TRUE(VM.count(MAV));
324   EXPECT_FALSE(VM.count(&A));
325 }
326 
327 TEST(ValueMapperTest, MapValueLocalAsMetadataToConstant) {
328   LLVMContext Context;
329   auto *Int8 = Type::getInt8Ty(Context);
330   FunctionType *FTy = FunctionType::get(Type::getVoidTy(Context), Int8, false);
331   std::unique_ptr<Function> F(
332       Function::Create(FTy, GlobalValue::ExternalLinkage, "F"));
333 
334   // Map a local value to a constant.
335   Argument &A = *F->arg_begin();
336   Constant &C = *ConstantInt::get(Int8, 42);
337   ValueToValueMapTy VM;
338   VM[&A] = &C;
339 
340   // Look up the metadata-as-value wrapper.  Don't crash.
341   auto *MDA = MetadataAsValue::get(Context, ValueAsMetadata::get(&A));
342   auto *MDC = MetadataAsValue::get(Context, ValueAsMetadata::get(&C));
343   EXPECT_TRUE(isa<LocalAsMetadata>(MDA->getMetadata()));
344   EXPECT_TRUE(isa<ConstantAsMetadata>(MDC->getMetadata()));
345   EXPECT_EQ(&C, MapValue(&A, VM));
346   EXPECT_EQ(MDC, MapValue(MDA, VM));
347 }
348 
349 } // end namespace
350