[LoongArch][GlobalISel] Adding initial GlobalISel infrastructure

Add an initial GlobalISel skeleton for LoongArch. It can
only run ir translator for `ret void`.

Author: zhaoqi5

llvm/lib/Target/LoongArch/CMakeLists.txt

@@ -6,15 +6,21 @@ tablegen(LLVM LoongArchGenAsmMatcher.inc -gen-asm-matcher)
 tablegen(LLVM LoongArchGenAsmWriter.inc -gen-asm-writer)
 tablegen(LLVM LoongArchGenDAGISel.inc -gen-dag-isel)
 tablegen(LLVM LoongArchGenDisassemblerTables.inc -gen-disassembler)
+tablegen(LLVM LoongArchGenGlobalISel.inc -gen-global-isel)
 tablegen(LLVM LoongArchGenInstrInfo.inc -gen-instr-info)
 tablegen(LLVM LoongArchGenMCPseudoLowering.inc -gen-pseudo-lowering)
 tablegen(LLVM LoongArchGenMCCodeEmitter.inc -gen-emitter)
+tablegen(LLVM LoongArchGenRegisterBank.inc -gen-register-bank)
 tablegen(LLVM LoongArchGenRegisterInfo.inc -gen-register-info)
 tablegen(LLVM LoongArchGenSubtargetInfo.inc -gen-subtarget)
 
 add_public_tablegen_target(LoongArchCommonTableGen)
 
 add_llvm_target(LoongArchCodeGen
+  GISel/LoongArchCallLowering.cpp
+  GISel/LoongArchInstructionSelector.cpp
+  GISel/LoongArchLegalizerInfo.cpp
+  GISel/LoongArchRegisterBankInfo.cpp
   LoongArchAsmPrinter.cpp
   LoongArchDeadRegisterDefinitions.cpp
   LoongArchExpandAtomicPseudoInsts.cpp
@@ -37,6 +43,7 @@ add_llvm_target(LoongArchCodeGen
   CodeGen
   CodeGenTypes
   Core
+  GlobalISel
   LoongArchDesc
   LoongArchInfo
   MC

llvm/lib/Target/LoongArch/GISel/LoongArchCallLowering.cpp

@@ -0,0 +1,49 @@
+//===-- LoongArchCallLowering.cpp - Call lowering ---------------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+/// \file
+/// This file implements the lowering of LLVM calls to machine code calls for
+/// GlobalISel.
+//
+//===----------------------------------------------------------------------===//
+
+#include "LoongArchCallLowering.h"
+#include "LoongArchISelLowering.h"
+#include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h"
+
+using namespace llvm;
+
+LoongArchCallLowering::LoongArchCallLowering(const LoongArchTargetLowering &TLI)
+    : CallLowering(&TLI) {}
+
+bool LoongArchCallLowering::lowerReturn(MachineIRBuilder &MIRBuilder,
+                                        const Value *Val,
+                                        ArrayRef<Register> VRegs,
+                                        FunctionLoweringInfo &FLI) const {
+  MachineInstrBuilder Ret = MIRBuilder.buildInstrNoInsert(LoongArch::PseudoRET);
+
+  if (Val != nullptr)
+    return false;
+
+  MIRBuilder.insertInstr(Ret);
+  return true;
+}
+
+bool LoongArchCallLowering::lowerFormalArguments(
+    MachineIRBuilder &MIRBuilder, const Function &F,
+    ArrayRef<ArrayRef<Register>> VRegs, FunctionLoweringInfo &FLI) const {
+  if (F.arg_empty())
+    return true;
+
+  return false;
+}
+
+bool LoongArchCallLowering::lowerCall(MachineIRBuilder &MIRBuilder,
+                                      CallLoweringInfo &Info) const {
+  return false;
+}

llvm/lib/Target/LoongArch/GISel/LoongArchCallLowering.h

@@ -0,0 +1,44 @@
+//===-- LoongArchCallLowering.h - Call lowering -----------------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+/// \file
+/// This file describes how to lower LLVM calls to machine code calls.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_TARGET_LOONGARCH_LOONGARCHCALLLOWERING_H
+#define LLVM_LIB_TARGET_LOONGARCH_LOONGARCHCALLLOWERING_H
+
+#include "llvm/CodeGen/CallingConvLower.h"
+#include "llvm/CodeGen/GlobalISel/CallLowering.h"
+
+namespace llvm {
+
+class LoongArchTargetLowering;
+class MachineIRBuilder;
+
+class LoongArchCallLowering : public CallLowering {
+
+public:
+  LoongArchCallLowering(const LoongArchTargetLowering &TLI);
+
+  bool lowerReturn(MachineIRBuilder &MIRBuiler, const Value *Val,
+                   ArrayRef<Register> VRegs,
+                   FunctionLoweringInfo &FLI) const override;
+
+  bool lowerFormalArguments(MachineIRBuilder &MIRBuilder, const Function &F,
+                            ArrayRef<ArrayRef<Register>> VRegs,
+                            FunctionLoweringInfo &FLI) const override;
+
+  bool lowerCall(MachineIRBuilder &MIRBuilder,
+                 CallLoweringInfo &Info) const override;
+};
+
+} // end namespace llvm
+
+#endif // LLVM_LIB_TARGET_LOONGARCH_LOONGARCHCALLLOWERING_H

llvm/lib/Target/LoongArch/GISel/LoongArchInstructionSelector.cpp

@@ -0,0 +1,102 @@
+//===-- LoongArchInstructionSelector.cpp -------------------------*- C++ -*-==//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+/// \file
+/// This file implements the targeting of the InstructionSelector class for
+/// LoongArch.
+/// \todo This should be generated by TableGen.
+//===----------------------------------------------------------------------===//
+
+#include "LoongArchRegisterBankInfo.h"
+#include "LoongArchSubtarget.h"
+#include "LoongArchTargetMachine.h"
+#include "llvm/CodeGen/GlobalISel/GIMatchTableExecutorImpl.h"
+#include "llvm/CodeGen/GlobalISel/InstructionSelector.h"
+#include "llvm/IR/IntrinsicsLoongArch.h"
+#include "llvm/Support/Debug.h"
+
+#define DEBUG_TYPE "loongarch-isel"
+
+using namespace llvm;
+
+#define GET_GLOBALISEL_PREDICATE_BITSET
+#include "LoongArchGenGlobalISel.inc"
+#undef GET_GLOBALISEL_PREDICATE_BITSET
+
+namespace {
+
+class LoongArchInstructionSelector : public InstructionSelector {
+public:
+  LoongArchInstructionSelector(const LoongArchTargetMachine &TM,
+                               const LoongArchSubtarget &STI,
+                               const LoongArchRegisterBankInfo &RBI);
+
+  bool select(MachineInstr &MI) override;
+
+  static const char *getName() { return DEBUG_TYPE; }
+
+private:
+  // tblgen-erated 'select' implementation, used as the initial selector for
+  // the patterns that don't require complex C++.
+  bool selectImpl(MachineInstr &I, CodeGenCoverage &CoverageInfo) const;
+
+  const LoongArchSubtarget &STI;
+  const LoongArchInstrInfo &TII;
+  const LoongArchRegisterInfo &TRI;
+  const LoongArchRegisterBankInfo &RBI;
+  const LoongArchTargetMachine &TM;
+
+#define GET_GLOBALISEL_PREDICATES_DECL
+#include "LoongArchGenGlobalISel.inc"
+#undef GET_GLOBALISEL_PREDICATES_DECL
+
+#define GET_GLOBALISEL_TEMPORARIES_DECL
+#include "LoongArchGenGlobalISel.inc"
+#undef GET_GLOBALISEL_TEMPORARIES_DECL
+};
+
+} // end anonymous namespace
+
+#define GET_GLOBALISEL_IMPL
+#include "LoongArchGenGlobalISel.inc"
+#undef GET_GLOBALISEL_IMPL
+
+LoongArchInstructionSelector::LoongArchInstructionSelector(
+    const LoongArchTargetMachine &TM, const LoongArchSubtarget &STI,
+    const LoongArchRegisterBankInfo &RBI)
+    : STI(STI), TII(*STI.getInstrInfo()), TRI(*STI.getRegisterInfo()), RBI(RBI),
+      TM(TM),
+
+#define GET_GLOBALISEL_PREDICATES_INIT
+#include "LoongArchGenGlobalISel.inc"
+#undef GET_GLOBALISEL_PREDICATES_INIT
+#define GET_GLOBALISEL_TEMPORARIES_INIT
+#include "LoongArchGenGlobalISel.inc"
+#undef GET_GLOBALISEL_TEMPORARIES_INIT
+{
+}
+
+bool LoongArchInstructionSelector::select(MachineInstr &MI) {
+  if (!isPreISelGenericOpcode(MI.getOpcode())) {
+    // Certain non-generic instructions also need some special handling.
+    return true;
+  }
+
+  if (selectImpl(MI, *CoverageInfo))
+    return true;
+
+  return false;
+}
+
+namespace llvm {
+InstructionSelector *
+createLoongArchInstructionSelector(const LoongArchTargetMachine &TM,
+                                   const LoongArchSubtarget &Subtarget,
+                                   const LoongArchRegisterBankInfo &RBI) {
+  return new LoongArchInstructionSelector(TM, Subtarget, RBI);
+}
+} // end namespace llvm

llvm/lib/Target/LoongArch/GISel/LoongArchLegalizerInfo.cpp

@@ -0,0 +1,24 @@
+//===-- LoongArchLegalizerInfo.cpp ------------------------------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+/// \file
+/// This file implements the targeting of the Machinelegalizer class for
+/// LoongArch.
+/// \todo This should be generated by TableGen.
+//===----------------------------------------------------------------------===//
+
+#include "LoongArchLegalizerInfo.h"
+#include "llvm/CodeGen/TargetOpcodes.h"
+#include "llvm/CodeGen/ValueTypes.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/Type.h"
+
+using namespace llvm;
+
+LoongArchLegalizerInfo::LoongArchLegalizerInfo(const LoongArchSubtarget &ST) {
+  getLegacyLegalizerInfo().computeTables();
+}

llvm/lib/Target/LoongArch/GISel/LoongArchLegalizerInfo.h

@@ -0,0 +1,29 @@
+//===-- LoongArchLegalizerInfo.h --------------------------------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+/// \file
+/// This file declares the targeting of the Machinelegalizer class for
+/// LoongArch.
+/// \todo This should be generated by TableGen.
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_TARGET_LOONGARCH_LOONGARCHMACHINELEGALIZER_H
+#define LLVM_LIB_TARGET_LOONGARCH_LOONGARCHMACHINELEGALIZER_H
+
+#include "llvm/CodeGen/GlobalISel/LegalizerInfo.h"
+
+namespace llvm {
+
+class LoongArchSubtarget;
+
+class LoongArchLegalizerInfo : public LegalizerInfo {
+public:
+  LoongArchLegalizerInfo(const LoongArchSubtarget &ST);
+};
+} // end namespace llvm
+
+#endif // LLVM_LIB_TARGET_LOONGARCH_LOONGARCHMACHINELEGALIZER_H

llvm/lib/Target/LoongArch/GISel/LoongArchRegisterBankInfo.cpp

@@ -0,0 +1,27 @@
+//===-- LoongArchRegisterBankInfo.cpp ---------------------------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+/// \file
+/// This file implements the targeting of the RegisterBankInfo class for
+/// LoongArch.
+/// \todo This should be generated by TableGen.
+//===----------------------------------------------------------------------===//
+
+#include "LoongArchRegisterBankInfo.h"
+#include "MCTargetDesc/LoongArchMCTargetDesc.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/RegisterBank.h"
+#include "llvm/CodeGen/RegisterBankInfo.h"
+#include "llvm/CodeGen/TargetRegisterInfo.h"
+
+#define GET_TARGET_REGBANK_IMPL
+#include "LoongArchGenRegisterBank.inc"
+
+using namespace llvm;
+
+LoongArchRegisterBankInfo::LoongArchRegisterBankInfo(unsigned HwMode)
+    : LoongArchGenRegisterBankInfo(HwMode) {}

llvm/lib/Target/LoongArch/GISel/LoongArchRegisterBankInfo.h

@@ -0,0 +1,39 @@
+//===-- LoongArchRegisterBankInfo.h -----------------------------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+/// \file
+/// This file declares the targeting of the RegisterBankInfo class for
+/// LoongArch.
+/// \todo This should be generated by TableGen.
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_TARGET_LOONGARCH_LOONGARCHREGISTERBANKINFO_H
+#define LLVM_LIB_TARGET_LOONGARCH_LOONGARCHREGISTERBANKINFO_H
+
+#include "llvm/CodeGen/RegisterBankInfo.h"
+
+#define GET_REGBANK_DECLARATIONS
+#include "LoongArchGenRegisterBank.inc"
+
+namespace llvm {
+
+class TargetRegisterInfo;
+
+class LoongArchGenRegisterBankInfo : public RegisterBankInfo {
+protected:
+#define GET_TARGET_REGBANK_CLASS
+#include "LoongArchGenRegisterBank.inc"
+};
+
+/// This class provides the information for the target register banks.
+class LoongArchRegisterBankInfo final : public LoongArchGenRegisterBankInfo {
+public:
+  LoongArchRegisterBankInfo(unsigned HwMode);
+};
+} // end namespace llvm
+
+#endif // LLVM_LIB_TARGET_LOONGARCH_LOONGARCHREGISTERBANKINFO_H

llvm/lib/Target/LoongArch/GISel/LoongArchRegisterBanks.td

@@ -0,0 +1,16 @@
+//=- LoongArchRegisterBank.td - Describe the LoongArch Banks -*- tablegen -*-=//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+//
+//===----------------------------------------------------------------------===//
+
+/// General Purpose Registers: R.
+def GPRBRegBank : RegisterBank<"GPRB", [GPR]>;
+
+/// Floating Point Registers: F.
+def FPRBRegBank : RegisterBank<"FPRB", [FPR64]>;

llvm/lib/Target/LoongArch/LoongArch.h

@@ -20,6 +20,9 @@
 namespace llvm {
 class AsmPrinter;
 class FunctionPass;
+class InstructionSelector;
+class LoongArchRegisterBankInfo;
+class LoongArchSubtarget;
 class LoongArchTargetMachine;
 class MCInst;
 class MCOperand;
@@ -47,6 +50,11 @@ void initializeLoongArchMergeBaseOffsetOptPass(PassRegistry &);
 void initializeLoongArchOptWInstrsPass(PassRegistry &);
 void initializeLoongArchPreRAExpandPseudoPass(PassRegistry &);
 void initializeLoongArchExpandPseudoPass(PassRegistry &);
+
+InstructionSelector *
+createLoongArchInstructionSelector(const LoongArchTargetMachine &,
+                                   const LoongArchSubtarget &,
+                                   const LoongArchRegisterBankInfo &);
 } // end namespace llvm
 
 #endif // LLVM_LIB_TARGET_LOONGARCH_LOONGARCH_H