Add support for pattern matching MachineInsts.

https://reviews.llvm.org/D42439

Add Instcombine like matchers for MachineInstructions. There are only
globalISel matchers for now.

llvm-svn: 323400
diff --git a/llvm/unittests/CodeGen/GlobalISel/PatternMatchTest.cpp b/llvm/unittests/CodeGen/GlobalISel/PatternMatchTest.cpp
new file mode 100644
index 0000000..5b55738
--- /dev/null
+++ b/llvm/unittests/CodeGen/GlobalISel/PatternMatchTest.cpp
@@ -0,0 +1,329 @@
+//===- PatternMatchTest.cpp -----------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#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<TargetMachine> createTargetMachine() {
+  Triple TargetTriple("aarch64--");
+  std::string Error;
+  const Target *T = TargetRegistry::lookupTarget("", TargetTriple, Error);
+  if (!T)
+    return nullptr;
+
+  TargetOptions Options;
+  return std::unique_ptr<TargetMachine>(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 TargetMachine &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 = 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<unsigned> &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<TargetMachine> TM = createTargetMachine();
+  if (!TM)
+    return;
+  auto ModuleMMIPair = createDummyModule(Context, *TM, "");
+  MachineFunction *MF =
+      getMFFromMMI(ModuleMMIPair.first.get(), ModuleMMIPair.second.get());
+  SmallVector<unsigned, 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);
+  uint64_t Cst;
+  bool match = mi_match(MIBCst->getOperand(0).getReg(), MRI, m_ICst(Cst));
+  ASSERT_TRUE(match);
+  ASSERT_EQ(Cst, (uint64_t)42);
+}
+
+TEST(PatternMatchInstr, MatchBinaryOp) {
+  LLVMContext Context;
+  std::unique_ptr<TargetMachine> TM = createTargetMachine();
+  if (!TM)
+    return;
+  auto ModuleMMIPair = createDummyModule(Context, *TM, "");
+  MachineFunction *MF =
+      getMFFromMMI(ModuleMMIPair.first.get(), ModuleMMIPair.second.get());
+  SmallVector<unsigned, 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()));
+  ASSERT_TRUE(match);
+  unsigned Src0, Src1, Src2;
+  match = mi_match(MIBAdd->getOperand(0).getReg(), MRI,
+                   m_GAdd(m_Reg(Src0), m_Reg(Src1)));
+  ASSERT_TRUE(match);
+  ASSERT_EQ(Src0, Copies[0]);
+  ASSERT_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)));
+  ASSERT_TRUE(match);
+  ASSERT_EQ(Src0, MIBAdd->getOperand(0).getReg());
+  ASSERT_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)));
+  ASSERT_TRUE(match);
+  ASSERT_EQ(Src0, Copies[0]);
+  ASSERT_EQ(Src1, Copies[1]);
+  ASSERT_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.
+  uint64_t Cst;
+  match = mi_match(MIBMul2->getOperand(0).getReg(), MRI,
+                   m_GMul(m_ICst(Cst), m_Reg(Src0)));
+  ASSERT_TRUE(match);
+  ASSERT_EQ(Cst, (uint64_t)42);
+  ASSERT_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)));
+  ASSERT_FALSE(match);
+}
+
+TEST(PatternMatchInstr, MatchExtendsTrunc) {
+  LLVMContext Context;
+  std::unique_ptr<TargetMachine> TM = createTargetMachine();
+  if (!TM)
+    return;
+  auto ModuleMMIPair = createDummyModule(Context, *TM, "");
+  MachineFunction *MF =
+      getMFFromMMI(ModuleMMIPair.first.get(), ModuleMMIPair.second.get());
+  SmallVector<unsigned, 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);
+  unsigned Src0;
+  bool match =
+      mi_match(MIBTrunc->getOperand(0).getReg(), MRI, m_GTrunc(m_Reg(Src0)));
+  ASSERT_TRUE(match);
+  ASSERT_EQ(Src0, Copies[0]);
+  match =
+      mi_match(MIBAExt->getOperand(0).getReg(), MRI, m_GAnyExt(m_Reg(Src0)));
+  ASSERT_TRUE(match);
+  ASSERT_EQ(Src0, MIBTrunc->getOperand(0).getReg());
+
+  match = mi_match(MIBSExt->getOperand(0).getReg(), MRI, m_GSExt(m_Reg(Src0)));
+  ASSERT_TRUE(match);
+  ASSERT_EQ(Src0, MIBTrunc->getOperand(0).getReg());
+
+  match = mi_match(MIBZExt->getOperand(0).getReg(), MRI, m_GZExt(m_Reg(Src0)));
+  ASSERT_TRUE(match);
+  ASSERT_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))));
+  ASSERT_TRUE(match);
+  ASSERT_EQ(Src0, Copies[0]);
+
+  match = mi_match(MIBSExt->getOperand(0).getReg(), MRI,
+                   m_GSExt(m_GTrunc(m_Reg(Src0))));
+  ASSERT_TRUE(match);
+  ASSERT_EQ(Src0, Copies[0]);
+
+  match = mi_match(MIBZExt->getOperand(0).getReg(), MRI,
+                   m_GZExt(m_GTrunc(m_Reg(Src0))));
+  ASSERT_TRUE(match);
+  ASSERT_EQ(Src0, Copies[0]);
+}
+
+TEST(PatternMatchInstr, MatchSpecificType) {
+  LLVMContext Context;
+  std::unique_ptr<TargetMachine> TM = createTargetMachine();
+  if (!TM)
+    return;
+  auto ModuleMMIPair = createDummyModule(Context, *TM, "");
+  MachineFunction *MF =
+      getMFFromMMI(ModuleMMIPair.first.get(), ModuleMMIPair.second.get());
+  SmallVector<unsigned, 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]);
+
+  // Try to match a 64bit add.
+  ASSERT_FALSE(mi_match(MIBAdd->getOperand(0).getReg(), MRI,
+                        m_GAdd(m_SpecificType(s32), m_Reg())));
+  ASSERT_TRUE(mi_match(MIBAdd->getOperand(0).getReg(), MRI,
+                       m_GAdd(m_SpecificType(s64), m_Reg())));
+}
+
+TEST(PatternMatchInstr, MatchCombinators) {
+  LLVMContext Context;
+  std::unique_ptr<TargetMachine> TM = createTargetMachine();
+  if (!TM)
+    return;
+  auto ModuleMMIPair = createDummyModule(Context, *TM, "");
+  MachineFunction *MF =
+      getMFFromMMI(ModuleMMIPair.first.get(), ModuleMMIPair.second.get());
+  SmallVector<unsigned, 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]);
+  unsigned 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))));
+  ASSERT_TRUE(match);
+  ASSERT_EQ(Src0, Copies[0]);
+  ASSERT_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))));
+  ASSERT_FALSE(match);
+  match =
+      mi_match(MIBAdd->getOperand(0).getReg(), MRI,
+               m_any_of(m_SpecificType(s32), m_GAdd(m_Reg(Src0), m_Reg(Src1))));
+  ASSERT_TRUE(match);
+  ASSERT_EQ(Src0, Copies[0]);
+  ASSERT_EQ(Src1, Copies[1]);
+}
+} // namespace
+
+int main(int argc, char **argv) {
+  ::testing::InitGoogleTest(&argc, argv);
+  initLLVM();
+  return RUN_ALL_TESTS();
+}