xref: /llvm-project/llvm/unittests/CodeGen/RegAllocScoreTest.cpp (revision 62c7f035b4392c1933550eead6ddab35122720bc)
1 //===- MachineInstrTest.cpp -----------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "../lib/CodeGen/RegAllocScore.h"
10 #include "llvm/CodeGen/MachineBasicBlock.h"
11 #include "llvm/CodeGen/MachineFunction.h"
12 #include "llvm/CodeGen/MachineInstr.h"
13 #include "llvm/CodeGen/MachineMemOperand.h"
14 #include "llvm/CodeGen/MachineModuleInfo.h"
15 #include "llvm/CodeGen/TargetFrameLowering.h"
16 #include "llvm/CodeGen/TargetInstrInfo.h"
17 #include "llvm/CodeGen/TargetLowering.h"
18 #include "llvm/CodeGen/TargetSubtargetInfo.h"
19 #include "llvm/IR/DebugInfoMetadata.h"
20 #include "llvm/IR/IRBuilder.h"
21 #include "llvm/IR/ModuleSlotTracker.h"
22 #include "llvm/MC/MCAsmInfo.h"
23 #include "llvm/MC/MCSymbol.h"
24 #include "llvm/MC/TargetRegistry.h"
25 #include "llvm/Support/TargetSelect.h"
26 #include "llvm/Target/TargetMachine.h"
27 #include "llvm/Target/TargetOptions.h"
28 #include "llvm/TargetParser/Triple.h"
29 #include "gtest/gtest.h"
30 
31 using namespace llvm;
32 extern cl::opt<double> CopyWeight;
33 extern cl::opt<double> LoadWeight;
34 extern cl::opt<double> StoreWeight;
35 extern cl::opt<double> CheapRematWeight;
36 extern cl::opt<double> ExpensiveRematWeight;
37 
38 namespace {
39 // Include helper functions to ease the manipulation of MachineFunctions.
40 #include "MFCommon.inc"
41 
42 // MachineFunction::CreateMachineInstr doesn't copy the MCInstrDesc, it
43 // takes its address. So we want a bunch of pre-allocated mock MCInstrDescs.
44 #define MOCK_INSTR(MACRO)                                                      \
45   MACRO(Copy, TargetOpcode::COPY, 0)                                           \
46   MACRO(Load, 0, 1ULL << MCID::MayLoad)                                        \
47   MACRO(Store, 0, 1ULL << MCID::MayStore)                                      \
48   MACRO(LoadStore, 0, (1ULL << MCID::MayLoad) | (1ULL << MCID::MayStore))      \
49   MACRO(CheapRemat, 0, 1ULL << MCID::CheapAsAMove)                             \
50   MACRO(ExpensiveRemat, 0, 0)                                                  \
51   MACRO(Dbg, TargetOpcode::DBG_LABEL,                                          \
52         (1ULL << MCID::MayLoad) | (1ULL << MCID::MayStore))                    \
53   MACRO(InlAsm, TargetOpcode::INLINEASM,                                       \
54         (1ULL << MCID::MayLoad) | (1ULL << MCID::MayStore))                    \
55   MACRO(Kill, TargetOpcode::KILL,                                              \
56         (1ULL << MCID::MayLoad) | (1ULL << MCID::MayStore))
57 
58 enum MockInstrId {
59 #define MOCK_INSTR_ID(ID, IGNORE, IGNORE2) ID,
60   MOCK_INSTR(MOCK_INSTR_ID)
61 #undef MOCK_INSTR_ID
62       TotalMockInstrs
63 };
64 
65 const std::array<MCInstrDesc, MockInstrId::TotalMockInstrs> MockInstrDescs{{
66 #define MOCK_SPEC(IGNORE, OPCODE, FLAGS)                                       \
67   {OPCODE, 0, 0, 0, 0, 0, 0, FLAGS, 0, nullptr, nullptr},
68     MOCK_INSTR(MOCK_SPEC)
69 #undef MOCK_SPEC
70 }};
71 
72 MachineInstr *createMockCopy(MachineFunction &MF) {
73   return MF.CreateMachineInstr(MockInstrDescs[MockInstrId::Copy], DebugLoc());
74 }
75 
76 MachineInstr *createMockLoad(MachineFunction &MF) {
77   return MF.CreateMachineInstr(MockInstrDescs[MockInstrId::Load], DebugLoc());
78 }
79 
80 MachineInstr *createMockStore(MachineFunction &MF) {
81   return MF.CreateMachineInstr(MockInstrDescs[MockInstrId::Store], DebugLoc());
82 }
83 
84 MachineInstr *createMockLoadStore(MachineFunction &MF) {
85   return MF.CreateMachineInstr(MockInstrDescs[MockInstrId::LoadStore],
86                                DebugLoc());
87 }
88 
89 MachineInstr *createMockCheapRemat(MachineFunction &MF) {
90   return MF.CreateMachineInstr(MockInstrDescs[MockInstrId::CheapRemat],
91                                DebugLoc());
92 }
93 
94 MachineInstr *createMockExpensiveRemat(MachineFunction &MF) {
95   return MF.CreateMachineInstr(MockInstrDescs[MockInstrId::ExpensiveRemat],
96                                DebugLoc());
97 }
98 
99 MachineInstr *createMockDebug(MachineFunction &MF) {
100   return MF.CreateMachineInstr(MockInstrDescs[MockInstrId::Dbg], DebugLoc());
101 }
102 
103 MachineInstr *createMockKill(MachineFunction &MF) {
104   return MF.CreateMachineInstr(MockInstrDescs[MockInstrId::Kill], DebugLoc());
105 }
106 
107 MachineInstr *createMockInlineAsm(MachineFunction &MF) {
108   return MF.CreateMachineInstr(MockInstrDescs[MockInstrId::InlAsm], DebugLoc());
109 }
110 
111 TEST(RegAllocScoreTest, SkipDebugKillInlineAsm) {
112   LLVMContext Ctx;
113   Module Mod("Module", Ctx);
114   auto MF = createMachineFunction(Ctx, Mod);
115 
116   auto *MBB = MF->CreateMachineBasicBlock();
117   MF->insert(MF->end(), MBB);
118   auto MBBFreqMock = [&](const MachineBasicBlock &_MBB) -> double {
119     assert(&_MBB == MBB);
120     return 0.5;
121   };
122   auto Next = MBB->end();
123   Next = MBB->insertAfter(Next, createMockInlineAsm(*MF));
124   Next = MBB->insertAfter(Next, createMockDebug(*MF));
125   Next = MBB->insertAfter(Next, createMockKill(*MF));
126   const auto Score = llvm::calculateRegAllocScore(
127       *MF, MBBFreqMock, [](const MachineInstr &) { return false; });
128   ASSERT_EQ(MF->size(), 1U);
129   ASSERT_EQ(Score, RegAllocScore());
130 }
131 
132 TEST(RegAllocScoreTest, Counts) {
133   LLVMContext Ctx;
134   Module Mod("Module", Ctx);
135   auto MF = createMachineFunction(Ctx, Mod);
136 
137   auto *MBB1 = MF->CreateMachineBasicBlock();
138   auto *MBB2 = MF->CreateMachineBasicBlock();
139   MF->insert(MF->end(), MBB1);
140   MF->insert(MF->end(), MBB2);
141   const double Freq1 = 0.5;
142   const double Freq2 = 10.0;
143   auto MBBFreqMock = [&](const MachineBasicBlock &MBB) -> double {
144     if (&MBB == MBB1)
145       return Freq1;
146     if (&MBB == MBB2)
147       return Freq2;
148     llvm_unreachable("We only created 2 basic blocks");
149   };
150   auto Next = MBB1->end();
151   Next = MBB1->insertAfter(Next, createMockCopy(*MF));
152   Next = MBB1->insertAfter(Next, createMockLoad(*MF));
153   Next = MBB1->insertAfter(Next, createMockLoad(*MF));
154   Next = MBB1->insertAfter(Next, createMockStore(*MF));
155   auto *CheapRemat = createMockCheapRemat(*MF);
156   MBB1->insertAfter(Next, CheapRemat);
157   Next = MBB2->end();
158   Next = MBB2->insertAfter(Next, createMockLoad(*MF));
159   Next = MBB2->insertAfter(Next, createMockStore(*MF));
160   Next = MBB2->insertAfter(Next, createMockLoadStore(*MF));
161   auto *ExpensiveRemat = createMockExpensiveRemat(*MF);
162   MBB2->insertAfter(Next, ExpensiveRemat);
163   auto IsRemat = [&](const MachineInstr &MI) {
164     return &MI == CheapRemat || &MI == ExpensiveRemat;
165   };
166   ASSERT_EQ(MF->size(), 2U);
167   const auto TotalScore =
168       llvm::calculateRegAllocScore(*MF, MBBFreqMock, IsRemat);
169   ASSERT_EQ(Freq1, TotalScore.copyCounts());
170   ASSERT_EQ(2.0 * Freq1 + Freq2, TotalScore.loadCounts());
171   ASSERT_EQ(Freq1 + Freq2, TotalScore.storeCounts());
172   ASSERT_EQ(Freq2, TotalScore.loadStoreCounts());
173   ASSERT_EQ(Freq1, TotalScore.cheapRematCounts());
174   ASSERT_EQ(Freq2, TotalScore.expensiveRematCounts());
175   ASSERT_EQ(TotalScore.getScore(),
176             TotalScore.copyCounts() * CopyWeight +
177                 TotalScore.loadCounts() * LoadWeight +
178                 TotalScore.storeCounts() * StoreWeight +
179                 TotalScore.loadStoreCounts() * (LoadWeight + StoreWeight) +
180                 TotalScore.cheapRematCounts() * CheapRematWeight +
181                 TotalScore.expensiveRematCounts() * ExpensiveRematWeight
182 
183   );
184 }
185 } // end namespace
186