xref: /llvm-project/llvm/unittests/CodeGen/MachineInstrTest.cpp (revision 90ecac01e9dcbcaf92781a6dcffa07a27191b661)
1 //===- MachineInstrTest.cpp -----------------------------------------------===//
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/CodeGen/MachineInstr.h"
11 #include "llvm/CodeGen/MachineInstrBuilder.h"
12 #include "llvm/CodeGen/MachineFunction.h"
13 #include "llvm/CodeGen/MachineModuleInfo.h"
14 #include "llvm/CodeGen/TargetFrameLowering.h"
15 #include "llvm/CodeGen/TargetInstrInfo.h"
16 #include "llvm/CodeGen/TargetLowering.h"
17 #include "llvm/CodeGen/TargetSubtargetInfo.h"
18 #include "llvm/Support/TargetRegistry.h"
19 #include "llvm/Support/TargetSelect.h"
20 #include "llvm/Target/TargetMachine.h"
21 #include "llvm/Target/TargetOptions.h"
22 #include "gtest/gtest.h"
23 
24 using namespace llvm;
25 
26 namespace {
27 // Add a few Bogus backend classes so we can create MachineInstrs without
28 // depending on a real target.
29 class BogusTargetLowering : public TargetLowering {
30 public:
31   BogusTargetLowering(TargetMachine &TM) : TargetLowering(TM) {}
32 };
33 
34 class BogusFrameLowering : public TargetFrameLowering {
35 public:
36   BogusFrameLowering()
37       : TargetFrameLowering(TargetFrameLowering::StackGrowsDown, 4, 4) {}
38 
39   void emitPrologue(MachineFunction &MF,
40                     MachineBasicBlock &MBB) const override {}
41   void emitEpilogue(MachineFunction &MF,
42                     MachineBasicBlock &MBB) const override {}
43   bool hasFP(const MachineFunction &MF) const override { return false; }
44 };
45 
46 class BogusSubtarget : public TargetSubtargetInfo {
47 public:
48   BogusSubtarget(TargetMachine &TM)
49       : TargetSubtargetInfo(Triple(""), "", "", {}, {}, nullptr, nullptr,
50                             nullptr, nullptr, nullptr, nullptr, nullptr),
51         FL(), TL(TM) {}
52   ~BogusSubtarget() override {}
53 
54   const TargetFrameLowering *getFrameLowering() const override { return &FL; }
55 
56   const TargetLowering *getTargetLowering() const override { return &TL; }
57 
58   const TargetInstrInfo *getInstrInfo() const override { return &TII; }
59 
60 private:
61   BogusFrameLowering FL;
62   BogusTargetLowering TL;
63   TargetInstrInfo TII;
64 };
65 
66 class BogusTargetMachine : public LLVMTargetMachine {
67 public:
68   BogusTargetMachine()
69       : LLVMTargetMachine(Target(), "", Triple(""), "", "", TargetOptions(),
70                           Reloc::Static, CodeModel::Small, CodeGenOpt::Default),
71         ST(*this) {}
72   ~BogusTargetMachine() override {}
73 
74   const TargetSubtargetInfo *getSubtargetImpl(const Function &) const override {
75     return &ST;
76   }
77 
78 private:
79   BogusSubtarget ST;
80 };
81 
82 std::unique_ptr<BogusTargetMachine> createTargetMachine() {
83   return llvm::make_unique<BogusTargetMachine>();
84 }
85 
86 std::unique_ptr<MachineFunction> createMachineFunction() {
87   LLVMContext Ctx;
88   Module M("Module", Ctx);
89   auto Type = FunctionType::get(Type::getVoidTy(Ctx), false);
90   auto F = Function::Create(Type, GlobalValue::ExternalLinkage, "Test", &M);
91 
92   auto TM = createTargetMachine();
93   unsigned FunctionNum = 42;
94   MachineModuleInfo MMI(TM.get());
95   const TargetSubtargetInfo &STI = *TM->getSubtargetImpl(*F);
96 
97   return llvm::make_unique<MachineFunction>(*F, *TM, STI, FunctionNum, MMI);
98 }
99 
100 // This test makes sure that MachineInstr::isIdenticalTo handles Defs correctly
101 // for various combinations of IgnoreDefs, and also that it is symmetrical.
102 TEST(IsIdenticalToTest, DifferentDefs) {
103   auto MF = createMachineFunction();
104 
105   unsigned short NumOps = 2;
106   unsigned char NumDefs = 1;
107   MCOperandInfo OpInfo[] = {
108       {0, 0, MCOI::OPERAND_REGISTER, 0},
109       {0, 1 << MCOI::OptionalDef, MCOI::OPERAND_REGISTER, 0}};
110   MCInstrDesc MCID = {
111       0, NumOps,  NumDefs, 0,      0, 1ULL << MCID::HasOptionalDef,
112       0, nullptr, nullptr, OpInfo, 0, nullptr};
113 
114   // Create two MIs with different virtual reg defs and the same uses.
115   unsigned VirtualDef1 = -42; // The value doesn't matter, but the sign does.
116   unsigned VirtualDef2 = -43;
117   unsigned VirtualUse = -44;
118 
119   auto MI1 = MF->CreateMachineInstr(MCID, DebugLoc());
120   MI1->addOperand(*MF, MachineOperand::CreateReg(VirtualDef1, /*isDef*/ true));
121   MI1->addOperand(*MF, MachineOperand::CreateReg(VirtualUse, /*isDef*/ false));
122 
123   auto MI2 = MF->CreateMachineInstr(MCID, DebugLoc());
124   MI2->addOperand(*MF, MachineOperand::CreateReg(VirtualDef2, /*isDef*/ true));
125   MI2->addOperand(*MF, MachineOperand::CreateReg(VirtualUse, /*isDef*/ false));
126 
127   // Check that they are identical when we ignore virtual register defs, but not
128   // when we check defs.
129   ASSERT_FALSE(MI1->isIdenticalTo(*MI2, MachineInstr::CheckDefs));
130   ASSERT_FALSE(MI2->isIdenticalTo(*MI1, MachineInstr::CheckDefs));
131 
132   ASSERT_TRUE(MI1->isIdenticalTo(*MI2, MachineInstr::IgnoreVRegDefs));
133   ASSERT_TRUE(MI2->isIdenticalTo(*MI1, MachineInstr::IgnoreVRegDefs));
134 
135   // Create two MIs with different virtual reg defs, and a def or use of a
136   // sentinel register.
137   unsigned SentinelReg = 0;
138 
139   auto MI3 = MF->CreateMachineInstr(MCID, DebugLoc());
140   MI3->addOperand(*MF, MachineOperand::CreateReg(VirtualDef1, /*isDef*/ true));
141   MI3->addOperand(*MF, MachineOperand::CreateReg(SentinelReg, /*isDef*/ true));
142 
143   auto MI4 = MF->CreateMachineInstr(MCID, DebugLoc());
144   MI4->addOperand(*MF, MachineOperand::CreateReg(VirtualDef2, /*isDef*/ true));
145   MI4->addOperand(*MF, MachineOperand::CreateReg(SentinelReg, /*isDef*/ false));
146 
147   // Check that they are never identical.
148   ASSERT_FALSE(MI3->isIdenticalTo(*MI4, MachineInstr::CheckDefs));
149   ASSERT_FALSE(MI4->isIdenticalTo(*MI3, MachineInstr::CheckDefs));
150 
151   ASSERT_FALSE(MI3->isIdenticalTo(*MI4, MachineInstr::IgnoreVRegDefs));
152   ASSERT_FALSE(MI4->isIdenticalTo(*MI3, MachineInstr::IgnoreVRegDefs));
153 }
154 
155 // Check that MachineInstrExpressionTrait::isEqual is symmetric and in sync with
156 // MachineInstrExpressionTrait::getHashValue
157 void checkHashAndIsEqualMatch(MachineInstr *MI1, MachineInstr *MI2) {
158   bool IsEqual1 = MachineInstrExpressionTrait::isEqual(MI1, MI2);
159   bool IsEqual2 = MachineInstrExpressionTrait::isEqual(MI2, MI1);
160 
161   ASSERT_EQ(IsEqual1, IsEqual2);
162 
163   auto Hash1 = MachineInstrExpressionTrait::getHashValue(MI1);
164   auto Hash2 = MachineInstrExpressionTrait::getHashValue(MI2);
165 
166   ASSERT_EQ(IsEqual1, Hash1 == Hash2);
167 }
168 
169 // This test makes sure that MachineInstrExpressionTraits::isEqual is in sync
170 // with MachineInstrExpressionTraits::getHashValue.
171 TEST(MachineInstrExpressionTraitTest, IsEqualAgreesWithGetHashValue) {
172   auto MF = createMachineFunction();
173 
174   unsigned short NumOps = 2;
175   unsigned char NumDefs = 1;
176   MCOperandInfo OpInfo[] = {
177       {0, 0, MCOI::OPERAND_REGISTER, 0},
178       {0, 1 << MCOI::OptionalDef, MCOI::OPERAND_REGISTER, 0}};
179   MCInstrDesc MCID = {
180       0, NumOps,  NumDefs, 0,      0, 1ULL << MCID::HasOptionalDef,
181       0, nullptr, nullptr, OpInfo, 0, nullptr};
182 
183   // Define a series of instructions with different kinds of operands and make
184   // sure that the hash function is consistent with isEqual for various
185   // combinations of them.
186   unsigned VirtualDef1 = -42;
187   unsigned VirtualDef2 = -43;
188   unsigned VirtualReg = -44;
189   unsigned SentinelReg = 0;
190   unsigned PhysicalReg = 45;
191 
192   auto VD1VU = MF->CreateMachineInstr(MCID, DebugLoc());
193   VD1VU->addOperand(*MF,
194                     MachineOperand::CreateReg(VirtualDef1, /*isDef*/ true));
195   VD1VU->addOperand(*MF,
196                     MachineOperand::CreateReg(VirtualReg, /*isDef*/ false));
197 
198   auto VD2VU = MF->CreateMachineInstr(MCID, DebugLoc());
199   VD2VU->addOperand(*MF,
200                     MachineOperand::CreateReg(VirtualDef2, /*isDef*/ true));
201   VD2VU->addOperand(*MF,
202                     MachineOperand::CreateReg(VirtualReg, /*isDef*/ false));
203 
204   auto VD1SU = MF->CreateMachineInstr(MCID, DebugLoc());
205   VD1SU->addOperand(*MF,
206                     MachineOperand::CreateReg(VirtualDef1, /*isDef*/ true));
207   VD1SU->addOperand(*MF,
208                     MachineOperand::CreateReg(SentinelReg, /*isDef*/ false));
209 
210   auto VD1SD = MF->CreateMachineInstr(MCID, DebugLoc());
211   VD1SD->addOperand(*MF,
212                     MachineOperand::CreateReg(VirtualDef1, /*isDef*/ true));
213   VD1SD->addOperand(*MF,
214                     MachineOperand::CreateReg(SentinelReg, /*isDef*/ true));
215 
216   auto VD2PU = MF->CreateMachineInstr(MCID, DebugLoc());
217   VD2PU->addOperand(*MF,
218                     MachineOperand::CreateReg(VirtualDef2, /*isDef*/ true));
219   VD2PU->addOperand(*MF,
220                     MachineOperand::CreateReg(PhysicalReg, /*isDef*/ false));
221 
222   auto VD2PD = MF->CreateMachineInstr(MCID, DebugLoc());
223   VD2PD->addOperand(*MF,
224                     MachineOperand::CreateReg(VirtualDef2, /*isDef*/ true));
225   VD2PD->addOperand(*MF,
226                     MachineOperand::CreateReg(PhysicalReg, /*isDef*/ true));
227 
228   checkHashAndIsEqualMatch(VD1VU, VD2VU);
229   checkHashAndIsEqualMatch(VD1VU, VD1SU);
230   checkHashAndIsEqualMatch(VD1VU, VD1SD);
231   checkHashAndIsEqualMatch(VD1VU, VD2PU);
232   checkHashAndIsEqualMatch(VD1VU, VD2PD);
233 
234   checkHashAndIsEqualMatch(VD2VU, VD1SU);
235   checkHashAndIsEqualMatch(VD2VU, VD1SD);
236   checkHashAndIsEqualMatch(VD2VU, VD2PU);
237   checkHashAndIsEqualMatch(VD2VU, VD2PD);
238 
239   checkHashAndIsEqualMatch(VD1SU, VD1SD);
240   checkHashAndIsEqualMatch(VD1SU, VD2PU);
241   checkHashAndIsEqualMatch(VD1SU, VD2PD);
242 
243   checkHashAndIsEqualMatch(VD1SD, VD2PU);
244   checkHashAndIsEqualMatch(VD1SD, VD2PD);
245 
246   checkHashAndIsEqualMatch(VD2PU, VD2PD);
247 }
248 
249 TEST(MachineBasicBlockTest, PhiRange) {
250   auto MF = createMachineFunction();
251 
252   // Create the main block.
253   auto BB = MF->CreateMachineBasicBlock();
254 
255   // Create some predecessors of it.
256   auto BB1 = MF->CreateMachineBasicBlock();
257   BB1->addSuccessor(BB);
258   auto BB2 = MF->CreateMachineBasicBlock();
259   BB2->addSuccessor(BB);
260 
261   // Make sure this doesn't crash if there are no phis.
262   for (auto &PN : BB->phis()) {
263     (void)PN;
264     ASSERT_TRUE(false) << "empty block should have no phis";
265   }
266 
267   // Make it a cycle.
268   BB->addSuccessor(BB);
269 
270   // Now insert some PHI nodes.
271   MCOperandInfo OpInfo[] = { { -1, 0, MCOI::OPERAND_UNKNOWN, 0} };
272   MCInstrDesc PHIMCID = {
273       TargetOpcode::PHI, 1, 1, 0, 0,
274       (1ULL << MCID::Pseudo) | (1ULL << MCID::Variadic), 0,
275       nullptr, nullptr, OpInfo, -1, nullptr};
276   auto P1 = BuildMI(*BB, BB->end(), DebugLoc(), PHIMCID, -101);
277   auto P2 = BuildMI(*BB, BB->end(), DebugLoc(), PHIMCID, -102);
278   auto P3 = BuildMI(*BB, BB->end(), DebugLoc(), PHIMCID, -103);
279 
280   // A non-PHI node.
281   MCInstrDesc ImpDefMCID = {
282       TargetOpcode::IMPLICIT_DEF, 1, 1, 0, 0,
283       (1ULL << MCID::Pseudo), 0,
284       nullptr, nullptr, OpInfo, -1, nullptr};
285   BuildMI(*BB, BB->end(), DebugLoc(), ImpDefMCID, -104);
286 
287   // Now wire up the incoming values that are interesting.
288   P1.addReg(-102).addMBB(BB);
289   P2.addReg(-101).addMBB(BB);
290   P3.addReg(-104).addMBB(BB);
291 
292   // Finally, let's iterate them, which is the thing we're trying to test.
293   // We'll use this to wire up the rest of the incoming values.
294   for (auto &PN : BB->phis()) {
295     EXPECT_TRUE(PN.isPHI());
296     PN.addOperand(*MF, MachineOperand::CreateReg(-100, /*isDef*/ false));
297     PN.addOperand(*MF, MachineOperand::CreateMBB(BB1));
298     PN.addOperand(*MF, MachineOperand::CreateReg(-100, /*isDef*/ false));
299     PN.addOperand(*MF, MachineOperand::CreateMBB(BB2));
300   }
301 
302   // Test that we can use const iterators and generally that the iterators
303   // behave like iterators.
304   MachineBasicBlock::const_iterator CI;
305   CI = BB->phis().begin();
306   EXPECT_NE(CI, BB->phis().end());
307 
308   // And iterate a const range.
309   for (const auto &PN : const_cast<const MachineBasicBlock *>(BB)->phis()) {
310     EXPECT_EQ(BB, PN.getOperand(2).getMBB());
311     EXPECT_EQ(BB1, PN.getOperand(4).getMBB());
312     EXPECT_EQ(BB2, PN.getOperand(6).getMBB());
313   }
314 }
315 } // end namespace
316