llvm-project/llvm/unittests/CodeGen/GlobalISel/PatternMatchTest.cpp

//===- PatternMatchTest.cpp -----------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#include "llvm/CodeGen/GlobalISel/ConstantFoldingMIRBuilder.h"
#include "llvm/CodeGen/GlobalISel/MIPatternMatch.h"
#include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h"
#include "llvm/CodeGen/GlobalISel/Utils.h"
#include "llvm/CodeGen/MIRParser/MIRParser.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/TargetFrameLowering.h"
#include "llvm/CodeGen/TargetInstrInfo.h"
#include "llvm/CodeGen/TargetLowering.h"
#include "llvm/CodeGen/TargetSubtargetInfo.h"
#include "llvm/Support/SourceMgr.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/TargetSelect.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
#include "gtest/gtest.h"

using namespace llvm;
using namespace MIPatternMatch;

namespace {

void initLLVM() {
  InitializeAllTargets();
  InitializeAllTargetMCs();
  InitializeAllAsmPrinters();
  InitializeAllAsmParsers();

  PassRegistry *Registry = PassRegistry::getPassRegistry();
  initializeCore(*Registry);
  initializeCodeGen(*Registry);
}

/// Create a TargetMachine. As we lack a dedicated always available target for
/// unittests, we go for "AArch64".
std::unique_ptr<LLVMTargetMachine> createTargetMachine() {
  Triple TargetTriple("aarch64--");
  std::string Error;
  const Target *T = TargetRegistry::lookupTarget("", TargetTriple, Error);
  if (!T)
    return nullptr;

  TargetOptions Options;
  return std::unique_ptr<LLVMTargetMachine>(static_cast<LLVMTargetMachine*>(
      T->createTargetMachine("AArch64", "", "", Options, None, None,
                             CodeGenOpt::Aggressive)));
}

std::unique_ptr<Module> parseMIR(LLVMContext &Context,
                                 std::unique_ptr<MIRParser> &MIR,
                                 const TargetMachine &TM, StringRef MIRCode,
                                 const char *FuncName, MachineModuleInfo &MMI) {
  SMDiagnostic Diagnostic;
  std::unique_ptr<MemoryBuffer> MBuffer = MemoryBuffer::getMemBuffer(MIRCode);
  MIR = createMIRParser(std::move(MBuffer), Context);
  if (!MIR)
    return nullptr;

  std::unique_ptr<Module> M = MIR->parseIRModule();
  if (!M)
    return nullptr;

  M->setDataLayout(TM.createDataLayout());

  if (MIR->parseMachineFunctions(*M, MMI))
    return nullptr;

  return M;
}

std::pair<std::unique_ptr<Module>, std::unique_ptr<MachineModuleInfo>>
createDummyModule(LLVMContext &Context, const LLVMTargetMachine &TM,
                  StringRef MIRFunc) {
  SmallString<512> S;
  StringRef MIRString = (Twine(R"MIR(
---
...
name: func
registers:
  - { id: 0, class: _ }
  - { id: 1, class: _ }
  - { id: 2, class: _ }
  - { id: 3, class: _ }
body: |
  bb.1:
    %0(s64) = COPY $x0
    %1(s64) = COPY $x1
    %2(s64) = COPY $x2
)MIR") + Twine(MIRFunc) + Twine("...\n"))
                            .toNullTerminatedStringRef(S);
  std::unique_ptr<MIRParser> MIR;
  auto MMI = std::make_unique<MachineModuleInfo>(&TM);
  std::unique_ptr<Module> M =
      parseMIR(Context, MIR, TM, MIRString, "func", *MMI);
  return make_pair(std::move(M), std::move(MMI));
}

static MachineFunction *getMFFromMMI(const Module *M,
                                     const MachineModuleInfo *MMI) {
  Function *F = M->getFunction("func");
  auto *MF = MMI->getMachineFunction(*F);
  return MF;
}

static void collectCopies(SmallVectorImpl<Register> &Copies,
                          MachineFunction *MF) {
  for (auto &MBB : *MF)
    for (MachineInstr &MI : MBB) {
      if (MI.getOpcode() == TargetOpcode::COPY)
        Copies.push_back(MI.getOperand(0).getReg());
    }
}

TEST(PatternMatchInstr, MatchIntConstant) {
  LLVMContext Context;
  std::unique_ptr<LLVMTargetMachine> TM = createTargetMachine();
  if (!TM)
    return;
  auto ModuleMMIPair = createDummyModule(Context, *TM, "");
  MachineFunction *MF =
      getMFFromMMI(ModuleMMIPair.first.get(), ModuleMMIPair.second.get());
  SmallVector<Register, 4> Copies;
  collectCopies(Copies, MF);
  MachineBasicBlock *EntryMBB = &*MF->begin();
  MachineIRBuilder B(*MF);
  MachineRegisterInfo &MRI = MF->getRegInfo();
  B.setInsertPt(*EntryMBB, EntryMBB->end());
  auto MIBCst = B.buildConstant(LLT::scalar(64), 42);
  int64_t Cst;
  bool match = mi_match(MIBCst->getOperand(0).getReg(), MRI, m_ICst(Cst));
  EXPECT_TRUE(match);
  EXPECT_EQ(Cst, 42);
}

TEST(PatternMatchInstr, MatchBinaryOp) {
  LLVMContext Context;
  std::unique_ptr<LLVMTargetMachine> TM = createTargetMachine();
  if (!TM)
    return;
  auto ModuleMMIPair = createDummyModule(Context, *TM, "");
  MachineFunction *MF =
      getMFFromMMI(ModuleMMIPair.first.get(), ModuleMMIPair.second.get());
  SmallVector<Register, 4> Copies;
  collectCopies(Copies, MF);
  MachineBasicBlock *EntryMBB = &*MF->begin();
  MachineIRBuilder B(*MF);
  MachineRegisterInfo &MRI = MF->getRegInfo();
  B.setInsertPt(*EntryMBB, EntryMBB->end());
  LLT s64 = LLT::scalar(64);
  auto MIBAdd = B.buildAdd(s64, Copies[0], Copies[1]);
  // Test case for no bind.
  bool match =
      mi_match(MIBAdd->getOperand(0).getReg(), MRI, m_GAdd(m_Reg(), m_Reg()));
  EXPECT_TRUE(match);
  Register Src0, Src1, Src2;
  match = mi_match(MIBAdd->getOperand(0).getReg(), MRI,
                   m_GAdd(m_Reg(Src0), m_Reg(Src1)));
  EXPECT_TRUE(match);
  EXPECT_EQ(Src0, Copies[0]);
  EXPECT_EQ(Src1, Copies[1]);

  // Build MUL(ADD %0, %1), %2
  auto MIBMul = B.buildMul(s64, MIBAdd, Copies[2]);

  // Try to match MUL.
  match = mi_match(MIBMul->getOperand(0).getReg(), MRI,
                   m_GMul(m_Reg(Src0), m_Reg(Src1)));
  EXPECT_TRUE(match);
  EXPECT_EQ(Src0, MIBAdd->getOperand(0).getReg());
  EXPECT_EQ(Src1, Copies[2]);

  // Try to match MUL(ADD)
  match = mi_match(MIBMul->getOperand(0).getReg(), MRI,
                   m_GMul(m_GAdd(m_Reg(Src0), m_Reg(Src1)), m_Reg(Src2)));
  EXPECT_TRUE(match);
  EXPECT_EQ(Src0, Copies[0]);
  EXPECT_EQ(Src1, Copies[1]);
  EXPECT_EQ(Src2, Copies[2]);

  // Test Commutativity.
  auto MIBMul2 = B.buildMul(s64, Copies[0], B.buildConstant(s64, 42));
  // Try to match MUL(Cst, Reg) on src of MUL(Reg, Cst) to validate
  // commutativity.
  int64_t Cst;
  match = mi_match(MIBMul2->getOperand(0).getReg(), MRI,
                   m_GMul(m_ICst(Cst), m_Reg(Src0)));
  EXPECT_TRUE(match);
  EXPECT_EQ(Cst, 42);
  EXPECT_EQ(Src0, Copies[0]);

  // Make sure commutative doesn't work with something like SUB.
  auto MIBSub = B.buildSub(s64, Copies[0], B.buildConstant(s64, 42));
  match = mi_match(MIBSub->getOperand(0).getReg(), MRI,
                   m_GSub(m_ICst(Cst), m_Reg(Src0)));
  EXPECT_FALSE(match);

  auto MIBFMul = B.buildInstr(TargetOpcode::G_FMUL, {s64},
                              {Copies[0], B.buildConstant(s64, 42)});
  // Match and test commutativity for FMUL.
  match = mi_match(MIBFMul->getOperand(0).getReg(), MRI,
                   m_GFMul(m_ICst(Cst), m_Reg(Src0)));
  EXPECT_TRUE(match);
  EXPECT_EQ(Cst, 42);
  EXPECT_EQ(Src0, Copies[0]);

  // FSUB
  auto MIBFSub = B.buildInstr(TargetOpcode::G_FSUB, {s64},
                              {Copies[0], B.buildConstant(s64, 42)});
  match = mi_match(MIBFSub->getOperand(0).getReg(), MRI,
                   m_GFSub(m_Reg(Src0), m_Reg()));
  EXPECT_TRUE(match);
  EXPECT_EQ(Src0, Copies[0]);

  // Build AND %0, %1
  auto MIBAnd = B.buildAnd(s64, Copies[0], Copies[1]);
  // Try to match AND.
  match = mi_match(MIBAnd->getOperand(0).getReg(), MRI,
                   m_GAnd(m_Reg(Src0), m_Reg(Src1)));
  EXPECT_TRUE(match);
  EXPECT_EQ(Src0, Copies[0]);
  EXPECT_EQ(Src1, Copies[1]);

  // Build OR %0, %1
  auto MIBOr = B.buildOr(s64, Copies[0], Copies[1]);
  // Try to match OR.
  match = mi_match(MIBOr->getOperand(0).getReg(), MRI,
                   m_GOr(m_Reg(Src0), m_Reg(Src1)));
  EXPECT_TRUE(match);
  EXPECT_EQ(Src0, Copies[0]);
  EXPECT_EQ(Src1, Copies[1]);

  // Try to use the FoldableInstructionsBuilder to build binary ops.
  ConstantFoldingMIRBuilder CFB(B.getState());
  LLT s32 = LLT::scalar(32);
  auto MIBCAdd =
      CFB.buildAdd(s32, CFB.buildConstant(s32, 0), CFB.buildConstant(s32, 1));
  // This should be a constant now.
  match = mi_match(MIBCAdd->getOperand(0).getReg(), MRI, m_ICst(Cst));
  EXPECT_TRUE(match);
  EXPECT_EQ(Cst, 1);
  auto MIBCAdd1 =
      CFB.buildInstr(TargetOpcode::G_ADD, {s32},
                     {CFB.buildConstant(s32, 0), CFB.buildConstant(s32, 1)});
  // This should be a constant now.
  match = mi_match(MIBCAdd1->getOperand(0).getReg(), MRI, m_ICst(Cst));
  EXPECT_TRUE(match);
  EXPECT_EQ(Cst, 1);

  // Try one of the other constructors of MachineIRBuilder to make sure it's
  // compatible.
  ConstantFoldingMIRBuilder CFB1(*MF);
  CFB1.setInsertPt(*EntryMBB, EntryMBB->end());
  auto MIBCSub =
      CFB1.buildInstr(TargetOpcode::G_SUB, {s32},
                      {CFB1.buildConstant(s32, 1), CFB1.buildConstant(s32, 1)});
  // This should be a constant now.
  match = mi_match(MIBCSub->getOperand(0).getReg(), MRI, m_ICst(Cst));
  EXPECT_TRUE(match);
  EXPECT_EQ(Cst, 0);

  auto MIBCSext1 =
      CFB1.buildInstr(TargetOpcode::G_SEXT_INREG, {s32},
                      {CFB1.buildConstant(s32, 0x01), uint64_t(8)});
  // This should be a constant now.
  match = mi_match(MIBCSext1->getOperand(0).getReg(), MRI, m_ICst(Cst));
  EXPECT_TRUE(match);
  EXPECT_EQ(1, Cst);

  auto MIBCSext2 =
      CFB1.buildInstr(TargetOpcode::G_SEXT_INREG, {s32},
                      {CFB1.buildConstant(s32, 0x80), uint64_t(8)});
  // This should be a constant now.
  match = mi_match(MIBCSext2->getOperand(0).getReg(), MRI, m_ICst(Cst));
  EXPECT_TRUE(match);
  EXPECT_EQ(-0x80, Cst);
}

TEST(PatternMatchInstr, MatchFPUnaryOp) {
  LLVMContext Context;
  std::unique_ptr<LLVMTargetMachine> TM = createTargetMachine();
  if (!TM)
    return;
  auto ModuleMMIPair = createDummyModule(Context, *TM, "");
  MachineFunction *MF =
      getMFFromMMI(ModuleMMIPair.first.get(), ModuleMMIPair.second.get());
  SmallVector<Register, 4> Copies;
  collectCopies(Copies, MF);
  MachineBasicBlock *EntryMBB = &*MF->begin();
  MachineIRBuilder B(*MF);
  MachineRegisterInfo &MRI = MF->getRegInfo();
  B.setInsertPt(*EntryMBB, EntryMBB->end());

  // Truncate s64 to s32.
  LLT s32 = LLT::scalar(32);
  auto Copy0s32 = B.buildFPTrunc(s32, Copies[0]);

  // Match G_FABS.
  auto MIBFabs = B.buildInstr(TargetOpcode::G_FABS, {s32}, {Copy0s32});
  bool match = mi_match(MIBFabs->getOperand(0).getReg(), MRI, m_GFabs(m_Reg()));
  EXPECT_TRUE(match);

  Register Src;
  auto MIBFNeg = B.buildInstr(TargetOpcode::G_FNEG, {s32}, {Copy0s32});
  match = mi_match(MIBFNeg->getOperand(0).getReg(), MRI, m_GFNeg(m_Reg(Src)));
  EXPECT_TRUE(match);
  EXPECT_EQ(Src, Copy0s32->getOperand(0).getReg());

  match = mi_match(MIBFabs->getOperand(0).getReg(), MRI, m_GFabs(m_Reg(Src)));
  EXPECT_TRUE(match);
  EXPECT_EQ(Src, Copy0s32->getOperand(0).getReg());

  // Build and match FConstant.
  auto MIBFCst = B.buildFConstant(s32, .5);
  const ConstantFP *TmpFP{};
  match = mi_match(MIBFCst->getOperand(0).getReg(), MRI, m_GFCst(TmpFP));
  EXPECT_TRUE(match);
  EXPECT_TRUE(TmpFP);
  APFloat APF((float).5);
  auto *CFP = ConstantFP::get(Context, APF);
  EXPECT_EQ(CFP, TmpFP);

  // Build double float.
  LLT s64 = LLT::scalar(64);
  auto MIBFCst64 = B.buildFConstant(s64, .5);
  const ConstantFP *TmpFP64{};
  match = mi_match(MIBFCst64->getOperand(0).getReg(), MRI, m_GFCst(TmpFP64));
  EXPECT_TRUE(match);
  EXPECT_TRUE(TmpFP64);
  APFloat APF64(.5);
  auto CFP64 = ConstantFP::get(Context, APF64);
  EXPECT_EQ(CFP64, TmpFP64);
  EXPECT_NE(TmpFP64, TmpFP);

  // Build half float.
  LLT s16 = LLT::scalar(16);
  auto MIBFCst16 = B.buildFConstant(s16, .5);
  const ConstantFP *TmpFP16{};
  match = mi_match(MIBFCst16->getOperand(0).getReg(), MRI, m_GFCst(TmpFP16));
  EXPECT_TRUE(match);
  EXPECT_TRUE(TmpFP16);
  bool Ignored;
  APFloat APF16(.5);
  APF16.convert(APFloat::IEEEhalf(), APFloat::rmNearestTiesToEven, &Ignored);
  auto CFP16 = ConstantFP::get(Context, APF16);
  EXPECT_EQ(TmpFP16, CFP16);
  EXPECT_NE(TmpFP16, TmpFP);
}

TEST(PatternMatchInstr, MatchExtendsTrunc) {
  LLVMContext Context;
  std::unique_ptr<LLVMTargetMachine> TM = createTargetMachine();
  if (!TM)
    return;
  auto ModuleMMIPair = createDummyModule(Context, *TM, "");
  MachineFunction *MF =
      getMFFromMMI(ModuleMMIPair.first.get(), ModuleMMIPair.second.get());
  SmallVector<Register, 4> Copies;
  collectCopies(Copies, MF);
  MachineBasicBlock *EntryMBB = &*MF->begin();
  MachineIRBuilder B(*MF);
  MachineRegisterInfo &MRI = MF->getRegInfo();
  B.setInsertPt(*EntryMBB, EntryMBB->end());
  LLT s64 = LLT::scalar(64);
  LLT s32 = LLT::scalar(32);

  auto MIBTrunc = B.buildTrunc(s32, Copies[0]);
  auto MIBAExt = B.buildAnyExt(s64, MIBTrunc);
  auto MIBZExt = B.buildZExt(s64, MIBTrunc);
  auto MIBSExt = B.buildSExt(s64, MIBTrunc);
  Register Src0;
  bool match =
      mi_match(MIBTrunc->getOperand(0).getReg(), MRI, m_GTrunc(m_Reg(Src0)));
  EXPECT_TRUE(match);
  EXPECT_EQ(Src0, Copies[0]);
  match =
      mi_match(MIBAExt->getOperand(0).getReg(), MRI, m_GAnyExt(m_Reg(Src0)));
  EXPECT_TRUE(match);
  EXPECT_EQ(Src0, MIBTrunc->getOperand(0).getReg());

  match = mi_match(MIBSExt->getOperand(0).getReg(), MRI, m_GSExt(m_Reg(Src0)));
  EXPECT_TRUE(match);
  EXPECT_EQ(Src0, MIBTrunc->getOperand(0).getReg());

  match = mi_match(MIBZExt->getOperand(0).getReg(), MRI, m_GZExt(m_Reg(Src0)));
  EXPECT_TRUE(match);
  EXPECT_EQ(Src0, MIBTrunc->getOperand(0).getReg());

  // Match ext(trunc src)
  match = mi_match(MIBAExt->getOperand(0).getReg(), MRI,
                   m_GAnyExt(m_GTrunc(m_Reg(Src0))));
  EXPECT_TRUE(match);
  EXPECT_EQ(Src0, Copies[0]);

  match = mi_match(MIBSExt->getOperand(0).getReg(), MRI,
                   m_GSExt(m_GTrunc(m_Reg(Src0))));
  EXPECT_TRUE(match);
  EXPECT_EQ(Src0, Copies[0]);

  match = mi_match(MIBZExt->getOperand(0).getReg(), MRI,
                   m_GZExt(m_GTrunc(m_Reg(Src0))));
  EXPECT_TRUE(match);
  EXPECT_EQ(Src0, Copies[0]);
}

TEST(PatternMatchInstr, MatchSpecificType) {
  LLVMContext Context;
  std::unique_ptr<LLVMTargetMachine> TM = createTargetMachine();
  if (!TM)
    return;
  auto ModuleMMIPair = createDummyModule(Context, *TM, "");
  MachineFunction *MF =
      getMFFromMMI(ModuleMMIPair.first.get(), ModuleMMIPair.second.get());
  SmallVector<Register, 4> Copies;
  collectCopies(Copies, MF);
  MachineBasicBlock *EntryMBB = &*MF->begin();
  MachineIRBuilder B(*MF);
  MachineRegisterInfo &MRI = MF->getRegInfo();
  B.setInsertPt(*EntryMBB, EntryMBB->end());

  // Try to match a 64bit add.
  LLT s64 = LLT::scalar(64);
  LLT s32 = LLT::scalar(32);
  auto MIBAdd = B.buildAdd(s64, Copies[0], Copies[1]);
  EXPECT_FALSE(mi_match(MIBAdd->getOperand(0).getReg(), MRI,
                        m_GAdd(m_SpecificType(s32), m_Reg())));
  EXPECT_TRUE(mi_match(MIBAdd->getOperand(0).getReg(), MRI,
                       m_GAdd(m_SpecificType(s64), m_Reg())));

  // Try to match the destination type of a bitcast.
  LLT v2s32 = LLT::vector(2, 32);
  auto MIBCast = B.buildCast(v2s32, Copies[0]);
  EXPECT_TRUE(
      mi_match(MIBCast->getOperand(0).getReg(), MRI, m_GBitcast(m_Reg())));
  EXPECT_TRUE(
      mi_match(MIBCast->getOperand(0).getReg(), MRI, m_SpecificType(v2s32)));
  EXPECT_TRUE(
      mi_match(MIBCast->getOperand(1).getReg(), MRI, m_SpecificType(s64)));

  // Build a PTRToInt and INTTOPTR and match and test them.
  LLT PtrTy = LLT::pointer(0, 64);
  auto MIBIntToPtr = B.buildCast(PtrTy, Copies[0]);
  auto MIBPtrToInt = B.buildCast(s64, MIBIntToPtr);
  Register Src0;

  // match the ptrtoint(inttoptr reg)
  bool match = mi_match(MIBPtrToInt->getOperand(0).getReg(), MRI,
                        m_GPtrToInt(m_GIntToPtr(m_Reg(Src0))));
  EXPECT_TRUE(match);
  EXPECT_EQ(Src0, Copies[0]);
}

TEST(PatternMatchInstr, MatchCombinators) {
  LLVMContext Context;
  std::unique_ptr<LLVMTargetMachine> TM = createTargetMachine();
  if (!TM)
    return;
  auto ModuleMMIPair = createDummyModule(Context, *TM, "");
  MachineFunction *MF =
      getMFFromMMI(ModuleMMIPair.first.get(), ModuleMMIPair.second.get());
  SmallVector<Register, 4> Copies;
  collectCopies(Copies, MF);
  MachineBasicBlock *EntryMBB = &*MF->begin();
  MachineIRBuilder B(*MF);
  MachineRegisterInfo &MRI = MF->getRegInfo();
  B.setInsertPt(*EntryMBB, EntryMBB->end());
  LLT s64 = LLT::scalar(64);
  LLT s32 = LLT::scalar(32);
  auto MIBAdd = B.buildAdd(s64, Copies[0], Copies[1]);
  Register Src0, Src1;
  bool match =
      mi_match(MIBAdd->getOperand(0).getReg(), MRI,
               m_all_of(m_SpecificType(s64), m_GAdd(m_Reg(Src0), m_Reg(Src1))));
  EXPECT_TRUE(match);
  EXPECT_EQ(Src0, Copies[0]);
  EXPECT_EQ(Src1, Copies[1]);
  // Check for s32 (which should fail).
  match =
      mi_match(MIBAdd->getOperand(0).getReg(), MRI,
               m_all_of(m_SpecificType(s32), m_GAdd(m_Reg(Src0), m_Reg(Src1))));
  EXPECT_FALSE(match);
  match =
      mi_match(MIBAdd->getOperand(0).getReg(), MRI,
               m_any_of(m_SpecificType(s32), m_GAdd(m_Reg(Src0), m_Reg(Src1))));
  EXPECT_TRUE(match);
  EXPECT_EQ(Src0, Copies[0]);
  EXPECT_EQ(Src1, Copies[1]);

  // Match a case where none of the predicates hold true.
  match = mi_match(
      MIBAdd->getOperand(0).getReg(), MRI,
      m_any_of(m_SpecificType(LLT::scalar(16)), m_GSub(m_Reg(), m_Reg())));
  EXPECT_FALSE(match);
}

TEST(PatternMatchInstr, MatchMiscellaneous) {
  LLVMContext Context;
  std::unique_ptr<LLVMTargetMachine> TM = createTargetMachine();
  if (!TM)
    return;
  auto ModuleMMIPair = createDummyModule(Context, *TM, "");
  MachineFunction *MF =
      getMFFromMMI(ModuleMMIPair.first.get(), ModuleMMIPair.second.get());
  SmallVector<Register, 4> Copies;
  collectCopies(Copies, MF);
  MachineBasicBlock *EntryMBB = &*MF->begin();
  MachineIRBuilder B(*MF);
  MachineRegisterInfo &MRI = MF->getRegInfo();
  B.setInsertPt(*EntryMBB, EntryMBB->end());
  LLT s64 = LLT::scalar(64);
  auto MIBAdd = B.buildAdd(s64, Copies[0], Copies[1]);
  // Make multiple uses of this add.
  B.buildCast(LLT::pointer(0, 32), MIBAdd);
  B.buildCast(LLT::pointer(1, 32), MIBAdd);
  bool match = mi_match(MIBAdd.getReg(0), MRI, m_GAdd(m_Reg(), m_Reg()));
  EXPECT_TRUE(match);
  match = mi_match(MIBAdd.getReg(0), MRI, m_OneUse(m_GAdd(m_Reg(), m_Reg())));
  EXPECT_FALSE(match);
}
} // namespace

int main(int argc, char **argv) {
  ::testing::InitGoogleTest(&argc, argv);
  initLLVM();
  return RUN_ALL_TESTS();
}