xref: /llvm-project/llvm/unittests/tools/llvm-exegesis/X86/SnippetRepetitorTest.cpp (revision 2b31a673de51061d0407b79127054a5083659efc)
1 //===-- SnippetRepetitorTest.cpp --------------------------------*- C++ -*-===//
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 "../Common/AssemblerUtils.h"
10 #include "LlvmState.h"
11 #include "MCInstrDescView.h"
12 #include "RegisterAliasing.h"
13 #include "TestBase.h"
14 #include "X86InstrInfo.h"
15 #include "llvm/CodeGen/MachineBasicBlock.h"
16 
17 namespace llvm {
18 namespace exegesis {
19 
20 void InitializeX86ExegesisTarget();
21 
22 namespace {
23 
24 using testing::ElementsAre;
25 using testing::Eq;
26 using testing::Field;
27 using testing::Property;
28 using testing::UnorderedElementsAre;
29 
30 class X86SnippetRepetitorTest : public X86TestBase {
31 protected:
32   void SetUp() override {
33     TM = State.createTargetMachine();
34     Context = std::make_unique<LLVMContext>();
35     Mod = std::make_unique<Module>("X86SnippetRepetitorTest", *Context);
36     Mod->setDataLayout(TM->createDataLayout());
37     MMI = std::make_unique<MachineModuleInfo>(TM.get());
38     MF = &createVoidVoidPtrMachineFunction("TestFn", Mod.get(), MMI.get());
39   }
40 
41   void TestCommon(Benchmark::RepetitionModeE RepetitionMode,
42                   unsigned SnippetInstructions = 1) {
43     const auto Repetitor = SnippetRepetitor::Create(RepetitionMode, State);
44     const std::vector<MCInst> Instructions(SnippetInstructions,
45                                            MCInstBuilder(X86::NOOP));
46     FunctionFiller Sink(*MF, {X86::EAX});
47     const auto Fill =
48         Repetitor->Repeat(Instructions, kMinInstructions, kLoopBodySize, false);
49     Fill(Sink);
50   }
51 
52   static constexpr const unsigned kMinInstructions = 3;
53   static constexpr const unsigned kLoopBodySize = 5;
54 
55   std::unique_ptr<LLVMTargetMachine> TM;
56   std::unique_ptr<LLVMContext> Context;
57   std::unique_ptr<Module> Mod;
58   std::unique_ptr<MachineModuleInfo> MMI;
59   MachineFunction *MF = nullptr;
60 };
61 
62 static auto HasOpcode = [](unsigned Opcode) {
63   return Property(&MachineInstr::getOpcode, Eq(Opcode));
64 };
65 
66 static auto LiveReg = [](unsigned Reg) {
67   return Field(&MachineBasicBlock::RegisterMaskPair::PhysReg, Eq(Reg));
68 };
69 
70 TEST_F(X86SnippetRepetitorTest, Duplicate) {
71   TestCommon(Benchmark::Duplicate);
72   // Duplicating creates a single basic block that repeats the instructions.
73   ASSERT_EQ(MF->getNumBlockIDs(), 1u);
74   EXPECT_THAT(MF->getBlockNumbered(0)->instrs(),
75               ElementsAre(HasOpcode(X86::NOOP), HasOpcode(X86::NOOP),
76                           HasOpcode(X86::NOOP), HasOpcode(X86::RET64)));
77 }
78 
79 TEST_F(X86SnippetRepetitorTest, DuplicateSnippetInstructionCount) {
80   TestCommon(Benchmark::Duplicate, 2);
81   // Duplicating a snippet of two instructions with the minimum number of
82   // instructions set to three duplicates the snippet twice for a total of
83   // four instructions.
84   ASSERT_EQ(MF->getNumBlockIDs(), 1u);
85   EXPECT_THAT(MF->getBlockNumbered(0)->instrs(),
86               ElementsAre(HasOpcode(X86::NOOP), HasOpcode(X86::NOOP),
87                           HasOpcode(X86::NOOP), HasOpcode(X86::NOOP),
88                           HasOpcode(X86::RET64)));
89 }
90 
91 TEST_F(X86SnippetRepetitorTest, Loop) {
92   TestCommon(Benchmark::Loop);
93   // Duplicating creates an entry block, a loop body and a ret block.
94   ASSERT_EQ(MF->getNumBlockIDs(), 3u);
95   const auto &LoopBlock = *MF->getBlockNumbered(1);
96   EXPECT_THAT(LoopBlock.instrs(),
97               ElementsAre(HasOpcode(X86::NOOP), HasOpcode(X86::NOOP),
98                           HasOpcode(X86::NOOP), HasOpcode(X86::NOOP),
99                           HasOpcode(X86::NOOP), HasOpcode(X86::ADD64ri8),
100                           HasOpcode(X86::JCC_1)));
101   EXPECT_THAT(LoopBlock.liveins(),
102               UnorderedElementsAre(
103                   LiveReg(X86::EAX),
104                   LiveReg(State.getExegesisTarget().getLoopCounterRegister(
105                       State.getTargetMachine().getTargetTriple()))));
106   EXPECT_THAT(MF->getBlockNumbered(2)->instrs(),
107               ElementsAre(HasOpcode(X86::RET64)));
108 }
109 
110 } // namespace
111 } // namespace exegesis
112 } // namespace llvm
113