[MIPS GlobalISel] Adding GlobalISel

Add GlobalISel infrastructure up to the point where we can select a ret
void.

Patch by Petar Avramovic.

Differential Revision: https://reviews.llvm.org/D43583

llvm-svn: 325888

llvm/lib/Target/Mips/CMakeLists.txt

@@ -23,21 +23,25 @@ add_llvm_target(MipsCodeGen
   Mips16RegisterInfo.cpp
   MipsAnalyzeImmediate.cpp
   MipsAsmPrinter.cpp
+  MipsCallLowering.cpp
   MipsCCState.cpp
   MipsConstantIslandPass.cpp
   MipsDelaySlotFiller.cpp
   MipsFastISel.cpp
   MipsHazardSchedule.cpp
   MipsInstrInfo.cpp
+  MipsInstructionSelector.cpp
   MipsISelDAGToDAG.cpp
   MipsISelLowering.cpp
   MipsFrameLowering.cpp
+  MipsLegalizerInfo.cpp
   MipsLongBranch.cpp
   MipsMCInstLower.cpp
   MipsMachineFunction.cpp
   MipsModuleISelDAGToDAG.cpp
   MipsOptimizePICCall.cpp
   MipsOs16.cpp
+  MipsRegisterBankInfo.cpp
   MipsRegisterInfo.cpp
   MipsSEFrameLowering.cpp
   MipsSEInstrInfo.cpp

llvm/lib/Target/Mips/LLVMBuild.txt

@@ -43,4 +43,5 @@ required_libraries =
  SelectionDAG
  Support
  Target
+ GlobalISel
 add_to_library_groups = Mips

llvm/lib/Target/Mips/Mips.h

@@ -22,6 +22,10 @@ namespace llvm {
   class MipsTargetMachine;
   class ModulePass;
   class FunctionPass;
+  class MipsRegisterBankInfo;
+  class MipsSubtarget;
+  class MipsTargetMachine;
+  class InstructionSelector;
 
   ModulePass *createMipsOs16Pass();
   ModulePass *createMips16HardFloatPass();
@@ -33,6 +37,10 @@ namespace llvm {
   FunctionPass *createMipsLongBranchPass();
   FunctionPass *createMipsConstantIslandPass();
   FunctionPass *createMicroMipsSizeReductionPass();
+
+  InstructionSelector *createMipsInstructionSelector(const MipsTargetMachine &,
+                                                     MipsSubtarget &,
+                                                     MipsRegisterBankInfo &);
 } // end namespace llvm;
 
 #endif

llvm/lib/Target/Mips/MipsCallLowering.cpp

@@ -0,0 +1,47 @@
+//===- MipsCallLowering.cpp -------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+/// \file
+/// This file implements the lowering of LLVM calls to machine code calls for
+/// GlobalISel.
+//
+//===----------------------------------------------------------------------===//
+
+#include "MipsCallLowering.h"
+#include "MipsISelLowering.h"
+#include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h"
+
+using namespace llvm;
+
+MipsCallLowering::MipsCallLowering(const MipsTargetLowering &TLI)
+    : CallLowering(&TLI) {}
+
+bool MipsCallLowering::lowerReturn(MachineIRBuilder &MIRBuilder,
+                                   const Value *Val, unsigned VReg) const {
+
+  MachineInstrBuilder Ret = MIRBuilder.buildInstrNoInsert(Mips::RetRA);
+
+  if (Val != nullptr) {
+    return false;
+  }
+  MIRBuilder.insertInstr(Ret);
+  return true;
+}
+
+bool MipsCallLowering::lowerFormalArguments(MachineIRBuilder &MIRBuilder,
+                                            const Function &F,
+                                            ArrayRef<unsigned> VRegs) const {
+
+  // Quick exit if there aren't any args.
+  if (F.arg_empty())
+    return true;
+
+  // Function had args, but we didn't lower them.
+  return false;
+}

llvm/lib/Target/Mips/MipsCallLowering.h

@@ -0,0 +1,40 @@
+//===- MipsCallLowering.h ---------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+/// \file
+/// This file describes how to lower LLVM calls to machine code calls.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_TARGET_MIPS_MIPSCALLLOWERING_H
+#define LLVM_LIB_TARGET_MIPS_MIPSCALLLOWERING_H
+
+#include "llvm/CodeGen/CallingConvLower.h"
+#include "llvm/CodeGen/GlobalISel/CallLowering.h"
+#include "llvm/CodeGen/ValueTypes.h"
+
+namespace llvm {
+
+class MipsTargetLowering;
+
+class MipsCallLowering : public CallLowering {
+
+public:
+  MipsCallLowering(const MipsTargetLowering &TLI);
+
+  bool lowerReturn(MachineIRBuilder &MIRBuiler, const Value *Val,
+                   unsigned VReg) const override;
+
+  bool lowerFormalArguments(MachineIRBuilder &MIRBuilder, const Function &F,
+                            ArrayRef<unsigned> VRegs) const override;
+};
+
+} // end namespace llvm
+
+#endif // LLVM_LIB_TARGET_MIPS_MIPSCALLLOWERING_H

llvm/lib/Target/Mips/MipsInstructionSelector.cpp

@@ -0,0 +1,66 @@
+//===- MipsInstructionSelector.cpp ------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+/// \file
+/// This file implements the targeting of the InstructionSelector class for
+/// Mips.
+/// \todo This should be generated by TableGen.
+//===----------------------------------------------------------------------===//
+
+#include "MipsRegisterBankInfo.h"
+#include "MipsSubtarget.h"
+#include "MipsTargetMachine.h"
+#include "llvm/Support/Debug.h"
+
+using namespace llvm;
+
+namespace {
+
+class MipsInstructionSelector : public InstructionSelector {
+public:
+  MipsInstructionSelector(const MipsTargetMachine &TM, const MipsSubtarget &STI,
+                          const MipsRegisterBankInfo &RBI);
+
+  bool select(MachineInstr &I, CodeGenCoverage &CoverageInfo) const override;
+
+private:
+  const MipsTargetMachine &TM;
+  const MipsSubtarget &STI;
+  const MipsInstrInfo &TII;
+  const MipsRegisterInfo &TRI;
+  const MipsRegisterBankInfo &RBI;
+};
+
+} // end anonymous namespace
+
+MipsInstructionSelector::MipsInstructionSelector(
+    const MipsTargetMachine &TM, const MipsSubtarget &STI,
+    const MipsRegisterBankInfo &RBI)
+    : InstructionSelector(), TM(TM), STI(STI), TII(*STI.getInstrInfo()),
+      TRI(*STI.getRegisterInfo()), RBI(RBI) {}
+
+bool MipsInstructionSelector::select(MachineInstr &I,
+                                     CodeGenCoverage &CoverageInfo) const {
+
+  if (!isPreISelGenericOpcode(I.getOpcode())) {
+    // Not global isel generic opcode.
+    // TODO: select copy
+    return true;
+  }
+
+  // We didn't select anything.
+  return false;
+}
+
+namespace llvm {
+InstructionSelector *createMipsInstructionSelector(const MipsTargetMachine &TM,
+                                                   MipsSubtarget &Subtarget,
+                                                   MipsRegisterBankInfo &RBI) {
+  return new MipsInstructionSelector(TM, Subtarget, RBI);
+}
+} // end namespace llvm

llvm/lib/Target/Mips/MipsLegalizerInfo.cpp

@@ -0,0 +1,24 @@
+//===- MipsLegalizerInfo.cpp ------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+/// \file
+/// This file implements the targeting of the Machinelegalizer class for Mips.
+/// \todo This should be generated by TableGen.
+//===----------------------------------------------------------------------===//
+
+#include "MipsLegalizerInfo.h"
+#include "llvm/CodeGen/TargetOpcodes.h"
+#include "llvm/CodeGen/ValueTypes.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/Type.h"
+
+using namespace llvm;
+
+MipsLegalizerInfo::MipsLegalizerInfo(const MipsSubtarget &ST) {
+  computeTables();
+}

llvm/lib/Target/Mips/MipsLegalizerInfo.h

@@ -0,0 +1,29 @@
+//===- MipsLegalizerInfo ----------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+/// \file
+/// This file declares the targeting of the Machinelegalizer class for Mips.
+/// \todo This should be generated by TableGen.
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_TARGET_MIPS_MIPSMACHINELEGALIZER_H
+#define LLVM_LIB_TARGET_MIPS_MIPSMACHINELEGALIZER_H
+
+#include "llvm/CodeGen/GlobalISel/LegalizerInfo.h"
+
+namespace llvm {
+
+class MipsSubtarget;
+
+/// This class provides legalization strategies.
+class MipsLegalizerInfo : public LegalizerInfo {
+public:
+  MipsLegalizerInfo(const MipsSubtarget &ST);
+};
+} // end namespace llvm
+#endif

llvm/lib/Target/Mips/MipsRegisterBankInfo.cpp

@@ -0,0 +1,26 @@
+//===- MipsRegisterBankInfo.cpp ---------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+/// \file
+/// This file implements the targeting of the RegisterBankInfo class for Mips.
+/// \todo This should be generated by TableGen.
+//===----------------------------------------------------------------------===//
+
+#include "MipsRegisterBankInfo.h"
+#include "llvm/CodeGen/GlobalISel/RegisterBank.h"
+#include "llvm/CodeGen/GlobalISel/RegisterBankInfo.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/TargetRegisterInfo.h"
+
+using namespace llvm;
+
+MipsGenRegisterBankInfo::MipsGenRegisterBankInfo()
+    : RegisterBankInfo(nullptr, 0) {}
+
+MipsRegisterBankInfo::MipsRegisterBankInfo(const TargetRegisterInfo &TRI)
+    : MipsGenRegisterBankInfo() {}

llvm/lib/Target/Mips/MipsRegisterBankInfo.h

@@ -0,0 +1,35 @@
+//===- MipsRegisterBankInfo.h -----------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+/// \file
+/// This file declares the targeting of the RegisterBankInfo class for Mips.
+/// \todo This should be generated by TableGen.
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_TARGET_MIPS_MIPSREGISTERBANKINFO_H
+#define LLVM_LIB_TARGET_MIPS_MIPSREGISTERBANKINFO_H
+
+#include "llvm/CodeGen/GlobalISel/RegisterBankInfo.h"
+
+namespace llvm {
+
+class TargetRegisterInfo;
+
+class MipsGenRegisterBankInfo : public RegisterBankInfo {
+// TODO: This should be auto-generated by TableGen.
+public:
+  MipsGenRegisterBankInfo();
+};
+
+/// This class provides the information for the target register banks.
+class MipsRegisterBankInfo final : public MipsGenRegisterBankInfo {
+public:
+  MipsRegisterBankInfo(const TargetRegisterInfo &TRI);
+};
+} // end namespace llvm
+#endif

llvm/lib/Target/Mips/MipsSubtarget.cpp

@@ -16,6 +16,9 @@
 #include "MipsMachineFunction.h"
 #include "MipsRegisterInfo.h"
 #include "MipsTargetMachine.h"
+#include "MipsCallLowering.h"
+#include "MipsLegalizerInfo.h"
+#include "MipsRegisterBankInfo.h"
 #include "llvm/IR/Attributes.h"
 #include "llvm/IR/Function.h"
 #include "llvm/Support/CommandLine.h"
@@ -177,6 +180,14 @@ MipsSubtarget::MipsSubtarget(const Triple &TT, StringRef CPU, StringRef FS,
       MSAWarningPrinted = true;
     }
   }
+
+  CallLoweringInfo.reset(new MipsCallLowering(*getTargetLowering()));
+  Legalizer.reset(new MipsLegalizerInfo(*this));
+
+  auto *RBI = new MipsRegisterBankInfo(*getRegisterInfo());
+  RegBankInfo.reset(RBI);
+  InstSelector.reset(createMipsInstructionSelector(
+      *static_cast<const MipsTargetMachine *>(&TM), *this, *RBI));
 }
 
 bool MipsSubtarget::isPositionIndependent() const {
@@ -234,3 +245,19 @@ bool MipsSubtarget::isABI_N64() const { return getABI().IsN64(); }
 bool MipsSubtarget::isABI_N32() const { return getABI().IsN32(); }
 bool MipsSubtarget::isABI_O32() const { return getABI().IsO32(); }
 const MipsABIInfo &MipsSubtarget::getABI() const { return TM.getABI(); }
+
+const CallLowering *MipsSubtarget::getCallLowering() const {
+  return CallLoweringInfo.get();
+}
+
+const LegalizerInfo *MipsSubtarget::getLegalizerInfo() const {
+  return Legalizer.get();
+}
+
+const RegisterBankInfo *MipsSubtarget::getRegBankInfo() const {
+  return RegBankInfo.get();
+}
+
+const InstructionSelector *MipsSubtarget::getInstructionSelector() const {
+  return InstSelector.get();
+}

llvm/lib/Target/Mips/MipsSubtarget.h

@@ -20,6 +20,10 @@
 #include "MipsInstrInfo.h"
 #include "llvm/CodeGen/SelectionDAGTargetInfo.h"
 #include "llvm/CodeGen/TargetSubtargetInfo.h"
+#include "llvm/CodeGen/GlobalISel/CallLowering.h"
+#include "llvm/CodeGen/GlobalISel/LegalizerInfo.h"
+#include "llvm/CodeGen/GlobalISel/RegisterBankInfo.h"
+#include "llvm/CodeGen/GlobalISel/InstructionSelector.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/MC/MCInstrItineraries.h"
 #include "llvm/Support/ErrorHandling.h"
@@ -349,6 +353,19 @@ public:
   const InstrItineraryData *getInstrItineraryData() const override {
     return &InstrItins;
   }
+
+protected:
+  // GlobalISel related APIs.
+  std::unique_ptr<CallLowering> CallLoweringInfo;
+  std::unique_ptr<LegalizerInfo> Legalizer;
+  std::unique_ptr<RegisterBankInfo> RegBankInfo;
+  std::unique_ptr<InstructionSelector> InstSelector;
+
+public:
+  const CallLowering *getCallLowering() const override;
+  const LegalizerInfo *getLegalizerInfo() const override;
+  const RegisterBankInfo *getRegBankInfo() const override;
+  const InstructionSelector *getInstructionSelector() const override;
 };
 } // End llvm namespace
 

llvm/lib/Target/Mips/MipsTargetMachine.cpp

@@ -23,6 +23,10 @@
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Analysis/TargetTransformInfo.h"
+#include "llvm/CodeGen/GlobalISel/IRTranslator.h"
+#include "llvm/CodeGen/GlobalISel/Legalizer.h"
+#include "llvm/CodeGen/GlobalISel/RegBankSelect.h"
+#include "llvm/CodeGen/GlobalISel/InstructionSelect.h"
 #include "llvm/CodeGen/BasicTTIImpl.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/Passes.h"
@@ -46,6 +50,9 @@ extern "C" void LLVMInitializeMipsTarget() {
   RegisterTargetMachine<MipselTargetMachine> Y(getTheMipselTarget());
   RegisterTargetMachine<MipsebTargetMachine> A(getTheMips64Target());
   RegisterTargetMachine<MipselTargetMachine> B(getTheMips64elTarget());
+
+  PassRegistry *PR = PassRegistry::getPassRegistry();
+  initializeGlobalISel(*PR);
 }
 
 static std::string computeDataLayout(const Triple &TT, StringRef CPU,
@@ -230,6 +237,10 @@ public:
   bool addInstSelector() override;
   void addPreEmitPass() override;
   void addPreRegAlloc() override;
+  bool addIRTranslator() override;
+  bool addLegalizeMachineIR() override;
+  bool addRegBankSelect() override;
+  bool addGlobalInstructionSelect() override;
 };
 
 } // end anonymous namespace
@@ -285,3 +296,23 @@ void MipsPassConfig::addPreEmitPass() {
   addPass(createMipsHazardSchedule());
   addPass(createMipsConstantIslandPass());
 }
+
+bool MipsPassConfig::addIRTranslator() {
+  addPass(new IRTranslator());
+  return false;
+}
+
+bool MipsPassConfig::addLegalizeMachineIR() {
+  addPass(new Legalizer());
+  return false;
+}
+
+bool MipsPassConfig::addRegBankSelect() {
+  addPass(new RegBankSelect());
+  return false;
+}
+
+bool MipsPassConfig::addGlobalInstructionSelect() {
+  addPass(new InstructionSelect());
+  return false;
+}

llvm/test/CodeGen/Mips/GlobalISel/irtranslator/ret.ll

@@ -0,0 +1,11 @@
+; NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+; RUN: llc -O0 -mtriple=mipsel-linux-gnu -global-isel -stop-after=irtranslator -verify-machineinstrs %s -o - | FileCheck %s -check-prefixes=MIPS32
+
+
+define void @void() {
+  ; MIPS32-LABEL: name: void
+  ; MIPS32: bb.1.entry:
+  ; MIPS32:   RetRA
+entry:
+  ret void
+}

llvm/test/CodeGen/Mips/GlobalISel/llvm-ir/ret.ll

@@ -0,0 +1,12 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc  -O0 -mtriple=mipsel-linux-gnu -global-isel  -verify-machineinstrs %s -o -| FileCheck %s -check-prefixes=MIPS32
+
+define void @void() {
+; MIPS32-LABEL: void:
+; MIPS32:       # %bb.0: # %entry
+; MIPS32-NEXT:    jr $ra
+; MIPS32-NEXT:    nop
+entry:
+  ret void
+}
+