[LoongArch 4/6] Add basic tablegen infra for LoongArch

[SixWeining]

Summary

This patch introduces basic tablegen infra such as
LoongArch{InstrFormats,InstrInfo,RegisterInfo,CallingConv,}.td.

For now, only add instruction definitions for LoongArch basic integer
operations.
Our initial target is a working MC layer rather than codegen,
so appropriate SelectionDAG patterns will come later.

Depends on D115860

[SixWeining]

rename the patches number from n to 5

[rengolin]

Adding owners of recent new targets to help onboarding this new target.

[rengolin]

I can't see anything wrong with this patch. It seems to have all the bits to start a target in the right places.

I'm assuming you have passed clang-format on all C++ files and headers.

As with the other patches, I'll leave this be until more people have had a look at it.

[SixWeining]

rename getTheLA{32,64}Target to getTheLoongArch{32,64}Target

[SixWeining]

In D115861#3206435, @rengolin wrote:

I can't see anything wrong with this patch. It seems to have all the bits to start a target in the right places.

I'm assuming you have passed clang-format on all C++ files and headers.

As with the other patches, I'll leave this be until more people have had a look at it.

Thanks @rengolin. Yes, we have passed clang-format on all C++ files and headers.

[xen0n]

llvm/lib/Target/LoongArch/LoongArchInstrFormats.td

44

As discussed in D115862, people should reach consensus on instruction format naming before continuing with coding.

llvm/lib/Target/LoongArch/LoongArchRegisterInfo.td

47

According to the LoongArch ELF psABI doc, we're pushing this code after the v0/v1 aliases are deprecated, so I think the aliases could simply be removed?

63

Is the "r21" alias needed, given it's identical to its canonical name?

103

Same here for fv0/fv1.

llvm/lib/Target/LoongArch/LoongArchSubtarget.cpp

32

Nit: why not something like generic-la64 to keep symmetry?

llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchAsmBackend.cpp

39

Typo: "determine"

45

Cannot figure this out even as Chinglish... Maybe you meant something like "Check for byte count not multiple of instruction word size"?

[MaskRay]

llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchAsmBackend.cpp

45

And avoid unneeded parens: if (Count % 4 != 0)

llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchMCAsmInfo.cpp

25

It's unnecessary to align =. Just remove alignment and // clang-format

[SixWeining]

Reply comments inline. I will update this revision soon.

llvm/lib/Target/LoongArch/LoongArchInstrFormats.td

44

Right. But this patch is parent of D115862 but not child.

Do other people have any comments for the instruction format naming? @rengolin @MaskRay

llvm/lib/Target/LoongArch/LoongArchRegisterInfo.td

47

Yes, v0/v1 are deprecated. I will remove them. Thanks.

63

Right. This alias is unnecessary and I will remove it although other targets have similar usage, like the CSKY:

78   def R26 : CSKYReg<26, "r26", ["r26"]>, DwarfRegNum<[26]>;
79   def R27 : CSKYReg<27, "r27", ["r27"]>, DwarfRegNum<[27]>;

103

OK. I will remove them.

llvm/lib/Target/LoongArch/LoongArchSubtarget.cpp

32

la464 is the name of a real CPU core designed by Loongson while generic-la32 is a dummy CPU name.

Currently we only defined the la464 ProcessorModel in LoongArch.td:

94 def : ProcessorModel<"la464", NoSchedModel, [Feature64Bit]>;

Maybe we shoulde define another 2 ProcessMode: generic-la64 and generic-la32? And change

CPU = Is64Bit ? "la464" : "generic-la32";

to

CPU = Is64Bit ? "generic-la64" : "generic-la32";

llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchAsmBackend.cpp

39

Yes. Thanks.

45

Thanks. I will change that.

45

OK. Thanks.

llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchMCAsmInfo.cpp

25

OK. I will change that. Thanks.

[SixWeining]

address comments from @xen0n and @MaskRay

In addition, add "s9" as the alias of register "r22".

[SixWeining]

add missing change to testcase

[xen0n]

llvm/lib/Target/LoongArch/LoongArchRegisterInfo.td

63

Hmm, I wonder if [""] or [] is correct; perhaps this "duplication" is necessary for proper functioning after all, I'm not quite sure. Maybe others more familiar with tblgen could clarify this.

[SixWeining]

llvm/lib/Target/LoongArch/LoongArchRegisterInfo.td

63

If we use [] , tblgen is not happy.
If we use [""], tblgen is happy but llvm-mc will crash. We must add this change:

let FallbackRegAltNameIndex = NoRegAltName in
def RegAliasName : RegAltNameIndex;

[rengolin]

llvm/lib/Target/LoongArch/LoongArchInstrFormats.td

44

I don't actually have a strong opinion on this...

My personal view is that this is at such a low level that (almost) only people that work on the target will have to deal with, so what constitutes "easy to read and understand" depends on the target's own context.

For example abbreviations of target-specific terms may not make much sense to other people but they're very clear to that target engineers.

Having said that, I do appreciate @xen0n's point of having a consistent format. This is more than just "what feels right" and is more about "how easy it is for outside people understand the code (by reading an external doc, for ex.)" as well as "what scales better and is more maintainable".

The argument that this is a new target and we ought to do better is also a good one. But at the same time, if there are different back-ends to other tools and only this one is different, that'd add maintenance cost to the target's community.

And while I agree that setting a good precedent is worthwhile, there could be resistance from other compilers/emulators to refactor their code without clear benefits, so the difference may end up permanent.

[SixWeining]

llvm/lib/Target/LoongArch/LoongArchInstrFormats.td

44

Thanks @rengolin @xen0n.

I think we'd better form a conclusion as soon as possible so that we can move on.

In the past days we tried to get more inputs from other people but no one leave their comments here. However, we discussed with other LoongArch compilers/emulators owners offline internally and just as @rengolin said they have no strong willing to modify the code by following the proposal from @xen0n especially in the case that GNU binutils has been upstreamed.

So we prefer to insist on current implementation in this patch. How do you think about?

[rengolin]

llvm/lib/Target/LoongArch/LoongArchInstrFormats.td

44

Indeed, even if the LoongArch engineers were willing, I doubt the GNU maintainers will welcome formatting changes to gcc, binutils based on opinions from the LLVM community.

To be honest, I wouldn't change this now even if the GNU community was willing to change because I know how long it takes to change things in the GNU community when there isn't a strong consensus. (TBH, the same is true here).

So, even though I don't have a strong preference, I do have a strong opinion: let's not change this now, please.

[xen0n]

llvm/lib/Target/LoongArch/LoongArchInstrFormats.td

44

Fine; it's true we (or rather I) have to first get the suggested scheme implemented in GNU first anyway, because it's even more important to maintain consistency across the different toolchains.

What I'd like to confirm is that the community still allows for the possibility for the current scheme to change, if the GNU side were to be updated. IMO setting this inconsistent mess into stone forever really is a shame, and it's entirely Loongson's fault to not discuss all of this upfront in a transparent way, eventually leading to this, but we don't have time machines and have to live on even though the whole conflict is avoidable. I'll continue to push for better and more consistent LoongArch documentation, implementation and teaching across the projects.

[rengolin]

llvm/lib/Target/LoongArch/LoongArchInstrFormats.td

44

You'll find that the LLVM community is much more amenable to refactoring than the GNU counterparts, so if you manage to convince them, we'll probably just follow suit.

I have tried coordinating language extensions, code generation and runtime behaviour with the GNU folks before (at a GNU cauldron and after that), but my efforts were met with disdain and nothing ever happened from there, so don't hold your breath.

[rengolin]

AFAICS, all issues have been fixed and the last contentious was about changing naming on the GNU side, which is completely out of scope in this series.

I'm approving this because it looks good to me, but if anyone has any further comments, the 6th patch is not approved yet, so we have time.

[xen0n]

Aside from my pet peeves against instruction format naming (and I agree to first merging as-is), only one minor comment and we're good to go!

llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchBaseInfo.h

36

Sorry for noticing this late, but don't we have simm21 for BEQZ/BNEZ and simm26 for B/BL?

[SixWeining]

In D115861#3304245, @xen0n wrote:

Aside from my pet peeves against instruction format naming (and I agree to first merging as-is), only one minor comment and we're good to go!

Thanks for your agreement. I have replied the comment inline.

llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchBaseInfo.h

36

Thanks. This patch is just to add basic tablegen infra, so not all kinds of operand type are added here. Branch and function call would be implemented in future and related operand types would be added then.

[xen0n]

llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchBaseInfo.h

36

Hmm, looking at surrounding code and usages of the other defines here, it seems all "lsl2" operands are not represented here, but correctly referenced in the td files; is that inconsistency intentional? Because branch instructions are clearly present in the tables.

[xen0n]

llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchBaseInfo.h

36

(silly English mistake in previous comment: "none of the lsl2 operands are represented here")

[SixWeining]

llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchBaseInfo.h

36

The OperandType here is to be used to implement instruction verification in future. Let me remove them and add them back when necessary. Thanks.

[SixWeining]

Address @xen0n's comments by removing currently unused OperandType.

[xen0n]

Seems good enough! I'll trust the other reviewers and maintainers here and just accept this.

(Thanks for fixing that nit, btw!)

llvm/lib/Target/LoongArch/CMakeLists.txt

 add_llvm_component_group(LoongArch)
 
+set(LLVM_TARGET_DEFINITIONS LoongArch.td)
+
+tablegen(LLVM LoongArchGenAsmMatcher.inc -gen-asm-matcher)
+tablegen(LLVM LoongArchGenAsmWriter.inc -gen-asm-writer)
+tablegen(LLVM LoongArchGenRegisterInfo.inc -gen-register-info)
+tablegen(LLVM LoongArchGenInstrInfo.inc -gen-instr-info)
+tablegen(LLVM LoongArchGenDAGISel.inc -gen-dag-isel)
+tablegen(LLVM LoongArchGenMCPseudoLowering.inc -gen-pseudo-lowering)
+tablegen(LLVM LoongArchGenMCCodeEmitter.inc -gen-emitter)
+tablegen(LLVM LoongArchGenSubtargetInfo.inc -gen-subtarget)
+
+add_public_tablegen_target(LoongArchCommonTableGen)
+
 add_llvm_target(LoongArchCodeGen
+  LoongArchAsmPrinter.cpp
+  LoongArchFrameLowering.cpp
+  LoongArchInstrInfo.cpp
+  LoongArchISelDAGToDAG.cpp
+  LoongArchISelLowering.cpp
+  LoongArchMCInstLower.cpp
+  LoongArchRegisterInfo.cpp
+  LoongArchSubtarget.cpp
   LoongArchTargetMachine.cpp
 
   LINK_COMPONENTS
   Analysis
   AsmPrinter
   CodeGen
   Core
   MC

llvm/lib/Target/LoongArch/LoongArch.h

+//===-- LoongArch.h - Top-level interface for LoongArch ---------*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains the entry points for global functions defined in the LLVM
+// LoongArch back-end.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_TARGET_LOONGARCH_LOONGARCH_H
+#define LLVM_LIB_TARGET_LOONGARCH_LOONGARCH_H
+
+#include "llvm/Target/TargetMachine.h"
+
+namespace llvm {
+class LoongArchTargetMachine;
+class AsmPrinter;
+class FunctionPass;
+class MCInst;
+class MCOperand;
+class MachineInstr;
+class MachineOperand;
+
+bool lowerLoongArchMachineInstrToMCInst(const MachineInstr *MI, MCInst &OutMI,
+                                        AsmPrinter &AP);
+bool lowerLoongArchMachineOperandToMCOperand(const MachineOperand &MO,
+                                             MCOperand &MCOp,
+                                             const AsmPrinter &AP);
+
+FunctionPass *createLoongArchISelDag(LoongArchTargetMachine &TM);
+} // namespace llvm
+
+#endif // LLVM_LIB_TARGET_LOONGARCH_LOONGARCH_H

llvm/lib/Target/LoongArch/LoongArch.td

+//===-- LoongArch.td - Describe the LoongArch Target -------*- 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
+//
+//===----------------------------------------------------------------------===//
+
+include "llvm/Target/Target.td"
+
+//===----------------------------------------------------------------------===//
+// LoongArch subtarget features and instruction predicates.
+//===----------------------------------------------------------------------===//
+
+// LoongArch is divided into two versions, the 32-bit version (LA32) and the
+// 64-bit version (LA64).
+def Feature64Bit
+    : SubtargetFeature<"64bit", "HasLA64", "true",
+                       "LA64 Basic Integer and Privilege Instruction Set">;
+def IsLA64
+    : Predicate<"Subtarget->is64Bit()">,
+      AssemblerPredicate<(all_of Feature64Bit),
+                         "LA64 Basic Integer and Privilege Instruction Set">;
+def IsLA32
+    : Predicate<"!Subtarget->is64Bit()">,
+      AssemblerPredicate<(all_of(not Feature64Bit)),
+                         "LA32 Basic Integer and Privilege Instruction Set">;
+
+defvar LA32 = DefaultMode;
+def LA64 : HwMode<"+64bit">;
+
+// Single Precision floating point
+def FeatureBasicF : SubtargetFeature<"f", "HasBasicF", "true",
+                                     "'F' (Single-Precision Floating-Point)">;
+def HasBasicF : Predicate<"Subtarget->hasBasicF()">,
+                AssemblerPredicate<(all_of FeatureBasicF),
+                                   "'F' (Single-Precision Floating-Point)">;
+
+// Double Precision floating point
+def FeatureBasicD : SubtargetFeature<"d", "HasBasicD", "true",
+                                     "'D' (Double-Precision Floating-Point)",
+                                     [FeatureBasicF]>;
+def HasBasicD : Predicate<"Subtarget->hasBasicD()">,
+                AssemblerPredicate<(all_of FeatureBasicD),
+                                   "'D' (Double-Precision Floating-Point)">;
+
+// Loongson SIMD eXtension (LSX)
+def FeatureExtLSX
+    : SubtargetFeature<"lsx", "HasExtLSX", "true",
+                       "'LSX' (Loongson SIMD Extension)", [FeatureBasicD]>;
+def HasExtLSX : Predicate<"Subtarget->hasExtLSX()">,
+                AssemblerPredicate<(all_of FeatureExtLSX),
+                                   "'LSX' (Loongson SIMD Extension)">;
+
+// Loongson Advanced SIMD eXtension (LASX)
+def FeatureExtLASX
+    : SubtargetFeature<"lasx", "HasExtLASX", "true",
+                       "'LASX' (Loongson Advanced SIMD Extension)",
+                       [FeatureExtLSX]>;
+def HasExtLASX
+    : Predicate<"Subtarget->hasExtLASX()">,
+      AssemblerPredicate<(all_of FeatureExtLASX),
+                         "'LASX' (Loongson Advanced SIMD Extension)">;
+
+// Loongson VirtualiZation (LVZ)
+def FeatureExtLVZ
+    : SubtargetFeature<"lvz", "HasExtLVZ", "true",
+                       "'LVZ' (Loongson Virtualization Extension)">;
+def HasExtLVZ : Predicate<"Subtarget->hasExtLVZ()">,
+                AssemblerPredicate<(all_of FeatureExtLVZ),
+                                   "'LVZ' (Loongson Virtualization Extension)">;
+
+// Loongson Binary Translation (LBT)
+def FeatureExtLBT
+    : SubtargetFeature<"lbt", "HasExtLBT", "true",
+                       "'LBT' (Loongson Binary Translation Extension)">;
+def HasExtLBT
+    : Predicate<"Subtarget->hasExtLBT()">,
+      AssemblerPredicate<(all_of FeatureExtLBT),
+                         "'LBT' (Loongson Binary Translation Extension)">;
+
+//===----------------------------------------------------------------------===//
+// Registers, instruction descriptions ...
+//===----------------------------------------------------------------------===//
+
+include "LoongArchRegisterInfo.td"
+include "LoongArchCallingConv.td"
+include "LoongArchInstrInfo.td"
+
+//===----------------------------------------------------------------------===//
+// LoongArch processors supported.
+//===----------------------------------------------------------------------===//
+
+def : ProcessorModel<"generic-la32", NoSchedModel, []>;
+def : ProcessorModel<"generic-la64", NoSchedModel, [Feature64Bit]>;
+
+def : ProcessorModel<"la464", NoSchedModel, [Feature64Bit,
+                                             FeatureExtLASX,
+                                             FeatureExtLVZ,
+                                             FeatureExtLBT]>;
+
+//===----------------------------------------------------------------------===//
+// Define the LoongArch target.
+//===----------------------------------------------------------------------===//
+
+def LoongArchInstrInfo : InstrInfo {
+  // guess mayLoad, mayStore, and hasSideEffects
+  // This option is a temporary migration help. It will go away.
+  let guessInstructionProperties = 1;
+}
+
+def LoongArchAsmParser : AsmParser {
+  let ShouldEmitMatchRegisterAltName = 1;
+  let AllowDuplicateRegisterNames = 1;
+}
+
+def LoongArchAsmParserVariant : AsmParserVariant {
+  int Variant = 0;
+  // Recognize hard coded registers.
+  string RegisterPrefix = "$";
+}
+
+def LoongArchAsmWriter : AsmWriter {
+  int PassSubtarget = 1;
+}
+
+def LoongArch : Target {
+  let InstructionSet = LoongArchInstrInfo;
+  let AssemblyParsers = [LoongArchAsmParser];
+  let AssemblyParserVariants = [LoongArchAsmParserVariant];
+  let AssemblyWriters = [LoongArchAsmWriter];
+  let AllowRegisterRenaming = 1;
+}

llvm/lib/Target/LoongArch/LoongArchAsmPrinter.h

+//===- LoongArchAsmPrinter.h - LoongArch LLVM Assembly Printer -*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// LoongArch Assembly printer class.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_TARGET_LOONGARCH_LOONGARCHASMPRINTER_H
+#define LLVM_LIB_TARGET_LOONGARCH_LOONGARCHASMPRINTER_H
+
+#include "LoongArchSubtarget.h"
+#include "llvm/CodeGen/AsmPrinter.h"
+#include "llvm/MC/MCStreamer.h"
+#include "llvm/Support/Compiler.h"
+
+namespace llvm {
+
+class LLVM_LIBRARY_VISIBILITY LoongArchAsmPrinter : public AsmPrinter {
+  const MCSubtargetInfo *STI;
+
+public:
+  explicit LoongArchAsmPrinter(TargetMachine &TM,
+                               std::unique_ptr<MCStreamer> Streamer)
+      : AsmPrinter(TM, std::move(Streamer)), STI(TM.getMCSubtargetInfo()) {}
+
+  StringRef getPassName() const override {
+    return "LoongArch Assembly Printer";
+  }
+
+  bool runOnMachineFunction(MachineFunction &MF) override;
+
+  void emitInstruction(const MachineInstr *MI) override;
+
+  // tblgen'erated function.
+  bool emitPseudoExpansionLowering(MCStreamer &OutStreamer,
+                                   const MachineInstr *MI);
+};
+
+} // end namespace llvm
+
+#endif // LLVM_LIB_TARGET_LOONGARCH_LOONGARCHASMPRINTER_H

llvm/lib/Target/LoongArch/LoongArchAsmPrinter.cpp

+//===- LoongArchAsmPrinter.cpp - LoongArch LLVM Assembly Printer -*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains a printer that converts from our internal representation
+// of machine-dependent LLVM code to GAS-format LoongArch assembly language.
+//
+//===----------------------------------------------------------------------===//
+
+#include "LoongArchAsmPrinter.h"
+#include "LoongArch.h"
+#include "LoongArchTargetMachine.h"
+#include "TargetInfo/LoongArchTargetInfo.h"
+#include "llvm/CodeGen/AsmPrinter.h"
+#include "llvm/MC/TargetRegistry.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "loongarch-asm-printer"
+
+// Simple pseudo-instructions have their lowering (with expansion to real
+// instructions) auto-generated.
+#include "LoongArchGenMCPseudoLowering.inc"
+
+void LoongArchAsmPrinter::emitInstruction(const MachineInstr *MI) {
+  // Do any auto-generated pseudo lowerings.
+  if (emitPseudoExpansionLowering(*OutStreamer, MI))
+    return;
+
+  MCInst TmpInst;
+  if (!lowerLoongArchMachineInstrToMCInst(MI, TmpInst, *this))
+    EmitToStreamer(*OutStreamer, TmpInst);
+}
+
+bool LoongArchAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
+  AsmPrinter::runOnMachineFunction(MF);
+  return true;
+}
+
+// Force static initialization.
+extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeLoongArchAsmPrinter() {
+  RegisterAsmPrinter<LoongArchAsmPrinter> X(getTheLoongArch32Target());
+  RegisterAsmPrinter<LoongArchAsmPrinter> Y(getTheLoongArch64Target());
+}

llvm/lib/Target/LoongArch/LoongArchCallingConv.td

+//=- LoongArchCallingConv.td - Calling Conventions LoongArch -*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This describes the calling conventions for the LoongArch architecture.
+//
+//===----------------------------------------------------------------------===//
+
+def CSR_ILP32S_LP64S
+    : CalleeSavedRegs<(add R1, (sequence "R%u", 22, 31))>;
+
+def CSR_ILP32F_LP64F
+    : CalleeSavedRegs<(add CSR_ILP32S_LP64S, (sequence "F%u", 24, 31))>;
+
+def CSR_ILP32D_LP64D
+    : CalleeSavedRegs<(add CSR_ILP32S_LP64S, (sequence "F%u_64", 24, 31))>;
+
+// Needed for implementation of LoongArchRegisterInfo::getNoPreservedMask()
+def CSR_NoRegs : CalleeSavedRegs<(add)>;

llvm/lib/Target/LoongArch/LoongArchFrameLowering.h

+//=- LoongArchFrameLowering.h - TargetFrameLowering for LoongArch -*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This class implements LoongArch-specific bits of TargetFrameLowering class.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_TARGET_LOONGARCH_LOONGARCHFRAMELOWERING_H
+#define LLVM_LIB_TARGET_LOONGARCH_LOONGARCHFRAMELOWERING_H
+
+#include "llvm/CodeGen/TargetFrameLowering.h"
+
+namespace llvm {
+class LoongArchSubtarget;
+
+class LoongArchFrameLowering : public TargetFrameLowering {
+  const LoongArchSubtarget &STI;
+
+public:
+  explicit LoongArchFrameLowering(const LoongArchSubtarget &STI)
+      : TargetFrameLowering(StackGrowsDown,
+                            /*StackAlignment=*/Align(16),
+                            /*LocalAreaOffset=*/0),
+        STI(STI) {}
+
+  void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
+  void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
+
+  bool hasFP(const MachineFunction &MF) const override;
+  bool hasBP(const MachineFunction &MF) const;
+};
+} // namespace llvm
+#endif // LLVM_LIB_TARGET_LOONGARCH_LOONGARCHFRAMELOWERING_H

llvm/lib/Target/LoongArch/LoongArchFrameLowering.cpp

+//===-- LoongArchFrameLowering.cpp - LoongArch Frame Information -*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains the LoongArch implementation of TargetFrameLowering class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "LoongArchFrameLowering.h"
+#include "LoongArchSubtarget.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/RegisterScavenging.h"
+#include "llvm/IR/DiagnosticInfo.h"
+#include "llvm/MC/MCDwarf.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "loongarch-frame-lowering"
+
+// Return true if the specified function should have a dedicated frame
+// pointer register.  This is true if frame pointer elimination is
+// disabled, if it needs dynamic stack realignment, if the function has
+// variable sized allocas, or if the frame address is taken.
+bool LoongArchFrameLowering::hasFP(const MachineFunction &MF) const {
+  const TargetRegisterInfo *RegInfo = MF.getSubtarget().getRegisterInfo();
+
+  const MachineFrameInfo &MFI = MF.getFrameInfo();
+  return MF.getTarget().Options.DisableFramePointerElim(MF) ||
+         RegInfo->hasStackRealignment(MF) || MFI.hasVarSizedObjects() ||
+         MFI.isFrameAddressTaken();
+}
+
+bool LoongArchFrameLowering::hasBP(const MachineFunction &MF) const {
+  const MachineFrameInfo &MFI = MF.getFrameInfo();
+  const TargetRegisterInfo *TRI = STI.getRegisterInfo();
+
+  return MFI.hasVarSizedObjects() && TRI->hasStackRealignment(MF);
+}
+
+void LoongArchFrameLowering::emitPrologue(MachineFunction &MF,
+                                          MachineBasicBlock &MBB) const {
+  // TODO: Implement this when we have function calls
+}
+
+void LoongArchFrameLowering::emitEpilogue(MachineFunction &MF,
+                                          MachineBasicBlock &MBB) const {
+  // TODO: Implement this when we have function calls
+}

llvm/lib/Target/LoongArch/LoongArchISelDAGToDAG.h

+//=- LoongArchISelDAGToDAG.h - A dag to dag inst selector for LoongArch ---===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines an instruction selector for the LoongArch target.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_TARGET_LOONGARCH_LOONGARCHISELDAGTODAG_H
+#define LLVM_LIB_TARGET_LOONGARCH_LOONGARCHISELDAGTODAG_H
+
+#include "LoongArch.h"
+#include "LoongArchTargetMachine.h"
+#include "llvm/CodeGen/SelectionDAGISel.h"
+
+// LoongArch-specific code to select LoongArch machine instructions for
+// SelectionDAG operations.
+namespace llvm {
+class LoongArchDAGToDAGISel : public SelectionDAGISel {
+  const LoongArchSubtarget *Subtarget = nullptr;
+
+public:
+  explicit LoongArchDAGToDAGISel(LoongArchTargetMachine &TM)
+      : SelectionDAGISel(TM) {}
+
+  StringRef getPassName() const override {
+    return "LoongArch DAG->DAG Pattern Instruction Selection";
+  }
+
+  bool runOnMachineFunction(MachineFunction &MF) override {
+    Subtarget = &MF.getSubtarget<LoongArchSubtarget>();
+    return SelectionDAGISel::runOnMachineFunction(MF);
+  }
+
+  void Select(SDNode *Node) override;
+
+// Include the pieces autogenerated from the target description.
+#include "LoongArchGenDAGISel.inc"
+};
+
+} // namespace llvm
+
+#endif // LLVM_LIB_TARGET_LOONGARCH_LOONGARCHISELDAGTODAG_H

llvm/lib/Target/LoongArch/LoongArchISelDAGToDAG.cpp

+//=- LoongArchISelDAGToDAG.cpp - A dag to dag inst selector for LoongArch -===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines an instruction selector for the LoongArch target.
+//
+//===----------------------------------------------------------------------===//
+
+#include "LoongArchISelDAGToDAG.h"
+#include "MCTargetDesc/LoongArchMCTargetDesc.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "loongarch-isel"
+
+void LoongArchDAGToDAGISel::Select(SDNode *Node) {
+  // If we have a custom node, we have already selected.
+  if (Node->isMachineOpcode()) {
+    LLVM_DEBUG(dbgs() << "== "; Node->dump(CurDAG); dbgs() << "\n");
+    Node->setNodeId(-1);
+    return;
+  }
+
+  // Instruction Selection not handled by the auto-generated tablegen selection
+  // should be handled here.
+  unsigned Opcode = Node->getOpcode();
+  SDLoc DL(Node);
+
+  switch (Opcode) {
+  default:
+    break;
+    // TODO: Add selection nodes needed later.
+  }
+
+  // Select the default instruction.
+  SelectCode(Node);
+}
+// This pass converts a legalized DAG into a LoongArch-specific DAG, ready
+// for instruction scheduling.
+FunctionPass *llvm::createLoongArchISelDag(LoongArchTargetMachine &TM) {
+  return new LoongArchDAGToDAGISel(TM);
+}

llvm/lib/Target/LoongArch/LoongArchISelLowering.h

+//=- LoongArchISelLowering.h - LoongArch DAG Lowering Interface -*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the interfaces that LoongArch uses to lower LLVM code into
+// a selection DAG.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_TARGET_LOONGARCH_LOONGARCHISELLOWERING_H
+#define LLVM_LIB_TARGET_LOONGARCH_LOONGARCHISELLOWERING_H
+
+#include "LoongArch.h"
+#include "llvm/CodeGen/CallingConvLower.h"
+#include "llvm/CodeGen/SelectionDAG.h"
+#include "llvm/CodeGen/TargetLowering.h"
+
+namespace llvm {
+class LoongArchSubtarget;
+struct LoongArchRegisterInfo;
+namespace LoongArchISD {
+enum NodeType : unsigned {
+  FIRST_NUMBER = ISD::BUILTIN_OP_END,
+
+  // TODO: add more LoongArchISDs
+
+};
+} // namespace LoongArchISD
+
+class LoongArchTargetLowering : public TargetLowering {
+  const LoongArchSubtarget &Subtarget;
+
+public:
+  explicit LoongArchTargetLowering(const TargetMachine &TM,
+                                   const LoongArchSubtarget &STI);
+
+  const LoongArchSubtarget &getSubtarget() const { return Subtarget; }
+};
+
+} // end namespace llvm
+
+#endif // LLVM_LIB_TARGET_LOONGARCH_LOONGARCHISELLOWERING_H

llvm/lib/Target/LoongArch/LoongArchISelLowering.cpp

+//=- LoongArchISelLowering.cpp - LoongArch DAG Lowering Implementation  ---===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the interfaces that LoongArch uses to lower LLVM code into
+// a selection DAG.
+//
+//===----------------------------------------------------------------------===//
+
+#include "LoongArchISelLowering.h"
+#include "LoongArch.h"
+#include "LoongArchMachineFunctionInfo.h"
+#include "LoongArchRegisterInfo.h"
+#include "LoongArchSubtarget.h"
+#include "LoongArchTargetMachine.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/Support/Debug.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "loongarch-isel-lowering"
+
+LoongArchTargetLowering::LoongArchTargetLowering(const TargetMachine &TM,
+                                                 const LoongArchSubtarget &STI)
+    : TargetLowering(TM), Subtarget(STI) {
+
+  MVT GRLenVT = Subtarget.getGRLenVT();
+  // Set up the register classes.
+  addRegisterClass(GRLenVT, &LoongArch::GPRRegClass);
+
+  // TODO: add necessary setOperationAction calls later.
+
+  // Compute derived properties from the register classes.
+  computeRegisterProperties(STI.getRegisterInfo());
+
+  setStackPointerRegisterToSaveRestore(LoongArch::R3);
+
+  // Function alignments.
+  const Align FunctionAlignment(4);
+  setMinFunctionAlignment(FunctionAlignment);
+}

llvm/lib/Target/LoongArch/LoongArchInstrFormats.td

+//===- LoongArchInstrFormats.td - LoongArch Instr. Formats -*- 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
+//
+//===----------------------------------------------------------------------===//
+
+//===----------------------------------------------------------------------===//
+//  Describe LoongArch instructions format
+//
+//  opcode       - operation code.
+//  {r/f}d       - destination operand.
+//  {r/f}{j/k/a} - source operand.
+//  immN         - immediate data.
+//
+//===----------------------------------------------------------------------===//
+
+class LAInst<dag outs, dag ins, string asmstr, list<dag> pattern = []>
+    : Instruction {
+  field bits<32> Inst;
+  // SoftFail is a field the disassembler can use to provide a way for
+  // instructions to not match without killing the whole decode process. It is
+  // mainly used for ARM, but Tablegen expects this field to exist or it fails
+  // to build the decode table.
+  field bits<32> SoftFail = 0;
+
+  let Namespace = "LoongArch";
+  let Size = 4;
+  let OutOperandList = outs;
+  let InOperandList = ins;
+  let AsmString = asmstr;
+  let Pattern = pattern;
+}
+
+// Pseudo instructions
+class Pseudo<dag outs, dag ins, string asmstr> : LAInst<outs, ins, asmstr> {
+  let isPseudo = 1;
+}
+
+// 2R-type
+// <opcode | rj | rd>
+class Fmt2R<bits<22> op, dag outs, dag ins, string asmstr,
+            list<dag> pattern = []> : LAInst<outs, ins, asmstr, pattern> {
+  bits<5> rj;
+  bits<5> rd;
+
+  let Inst{31-10} = op;
+  let Inst{9-5} = rj;
+  let Inst{4-0} = rd;
+}
+
+// 3R-type
+// <opcode | rk | rj | rd>
+// <opcode | fk | fj | fd>
+class Fmt3R<bits<17> op, dag outs, dag ins, string asmstr,
+            list<dag> pattern = []> : LAInst<outs, ins, asmstr, pattern> {
+  bits<5> rk;
+  bits<5> rj;
+  bits<5> rd;
+
+  let Inst{31-15} = op;
+  let Inst{14-10} = rk;
+  let Inst{9-5} = rj;
+  let Inst{4-0} = rd;
+}
+
+class Fmt3FR<bits<17> op, dag outs, dag ins, string asmstr,
+             list<dag> pattern = []> : LAInst<outs, ins, asmstr, pattern> {
+  bits<5> fk;
+  bits<5> fj;
+  bits<5> fd;
+
+  let Inst{31-15} = op;
+  let Inst{14-10} = fk;
+  let Inst{9-5} = fj;
+  let Inst{4-0} = fd;
+}
+
+// 4R-type
+// <opcode | ra | rk | rj | rd>
+class Fmt4R<bits<12> op, dag outs, dag ins, string asmstr,
+            list<dag> pattern = []> : LAInst<outs, ins, asmstr, pattern> {
+  bits<5> ra;
+  bits<5> rk;
+  bits<5> rj;
+  bits<5> rd;
+
+  let Inst{31-20} = op;
+  let Inst{19-15} = ra;
+  let Inst{14-10} = rk;
+  let Inst{9-5} = rj;
+  let Inst{4-0} = rd;
+}
+
+// 3RI2-type
+// <opcode | I2 | rk | rj | rd>
+class Fmt3RI2<bits<15> op, dag outs, dag ins, string asmstr,
+              list<dag> pattern = []> : LAInst<outs, ins, asmstr, pattern> {
+  bits<2> imm2;
+  bits<5> rk;
+  bits<5> rj;
+  bits<5> rd;
+
+  let Inst{31-17} = op;
+  let Inst{16-15} = imm2;
+  let Inst{14-10} = rk;
+  let Inst{9-5} = rj;
+  let Inst{4-0} = rd;
+}
+
+// 3RI3-type
+// <opcode | I3 | rk | rj | rd>
+class Fmt3RI3<bits<14> op, dag outs, dag ins, string asmstr,
+              list<dag> pattern = []> : LAInst<outs, ins, asmstr, pattern> {
+  bits<3> imm3;
+  bits<5> rk;
+  bits<5> rj;
+  bits<5> rd;
+
+  let Inst{31-18} = op;
+  let Inst{17-15} = imm3;
+  let Inst{14-10} = rk;
+  let Inst{9-5} = rj;
+  let Inst{4-0} = rd;
+}
+
+// 2RI5-type
+// <opcode | I5 | rj | rd>
+class Fmt2RI5<bits<17> op, dag outs, dag ins, string asmstr,
+              list<dag> pattern = []> : LAInst<outs, ins, asmstr, pattern> {
+  bits<5> imm5;
+  bits<5> rj;
+  bits<5> rd;
+
+  let Inst{31-15} = op;
+  let Inst{14-10} = imm5;
+  let Inst{9-5} = rj;
+  let Inst{4-0} = rd;
+}
+
+// 2RI6-type
+// <opcode | I6 | rj | rd>
+class Fmt2RI6<bits<16> op, dag outs, dag ins, string asmstr,
+              list<dag> pattern = []> : LAInst<outs, ins, asmstr, pattern> {
+  bits<6> imm6;
+  bits<5> rj;
+  bits<5> rd;
+
+  let Inst{31-16} = op;
+  let Inst{15-10} = imm6;
+  let Inst{9-5} = rj;
+  let Inst{4-0} = rd;
+}
+
+// 2RI8-type
+// <opcode | I8 | rj | rd>
+class Fmt2RI8<bits<14> op, dag outs, dag ins, string asmstr,
+              list<dag> pattern = []> : LAInst<outs, ins, asmstr, pattern> {
+  bits<8> imm8;
+  bits<5> rj;
+  bits<5> rd;
+
+  let Inst{31-18} = op;
+  let Inst{17-10} = imm8;
+  let Inst{9-5} = rj;
+  let Inst{4-0} = rd;
+}
+
+// 2RI12-type
+// <opcode | I12 | rj | rd>
+class Fmt2RI12<bits<10> op, dag outs, dag ins, string asmstr,
+               list<dag> pattern = []> : LAInst<outs, ins, asmstr, pattern> {
+  bits<12> imm12;
+  bits<5> rj;
+  bits<5> rd;
+
+  let Inst{31-22} = op;
+  let Inst{21-10} = imm12;
+  let Inst{9-5} = rj;
+  let Inst{4-0} = rd;
+}
+
+// 2RI14-type
+// <opcode | I14 | rj | rd>
+class Fmt2RI14<bits<8> op, dag outs, dag ins, string asmstr,
+               list<dag> pattern = []> : LAInst<outs, ins, asmstr, pattern> {
+  bits<14> imm14;
+  bits<5> rj;
+  bits<5> rd;
+
+  let Inst{31-24} = op;
+  let Inst{23-10} = imm14;
+  let Inst{9-5} = rj;
+  let Inst{4-0} = rd;
+}
+
+// 2RI16-type
+// <opcode | I16 | rj | rd>
+class Fmt2RI16<bits<6> op, dag outs, dag ins, string asmstr,
+               list<dag> pattern = []> : LAInst<outs, ins, asmstr, pattern> {
+  bits<16> imm16;
+  bits<5> rj;
+  bits<5> rd;
+
+  let Inst{31-26} = op;
+  let Inst{25-10} = imm16;
+  let Inst{9-5} = rj;
+  let Inst{4-0} = rd;
+}
+
+// 1RI20-type
+// <opcode | I20 | rd>
+class Fmt1RI20<bits<7> op, dag outs, dag ins, string asmstr,
+               list<dag> pattern = []> : LAInst<outs, ins, asmstr, pattern> {
+  bits<20> imm20;
+  bits<5> rd;
+
+  let Inst{31-25} = op;
+  let Inst{24-5} = imm20;
+  let Inst{4-0} = rd;
+}
+
+// 1RI21-type
+// <opcode | I21[15:0] | rj | I21[20:16]>
+class Fmt1RI21<bits<6> op, dag outs, dag ins, string asmstr,
+               list<dag> pattern = []> : LAInst<outs, ins, asmstr, pattern> {
+  bits<21> imm21;
+  bits<5> rj;
+
+  let Inst{31-26} = op;
+  let Inst{25-10} = imm21{15-0};
+  let Inst{9-5} = rj;
+  let Inst{4-0} = imm21{20-16};
+}
+
+// I15-type
+// <opcode | I15>
+class FmtI15<bits<17> op, dag outs, dag ins, string asmstr,
+             list<dag> pattern = []> : LAInst<outs, ins, asmstr, pattern> {
+  bits<15> imm15;
+
+  let Inst{31-15} = op;
+  let Inst{14-0} = imm15;
+}
+
+// I26-type
+// <opcode | I26[15:0] | I26[25:16]>
+class FmtI26<bits<6> op, dag outs, dag ins, string asmstr,
+             list<dag> pattern = []> : LAInst<outs, ins, asmstr, pattern> {
+  bits<26> imm26;
+
+  let Inst{31-26} = op;
+  let Inst{25-10} = imm26{15-0};
+  let Inst{9-0} = imm26{25-16};
+}
+
+// FmtBSTR_W
+// <opcode[11:1] | msb | opcode[0] | lsb | rj | rd>
+class FmtBSTR_W<bits<12> op, dag outs, dag ins, string asmstr,
+                list<dag> pattern = []> : LAInst<outs, ins, asmstr, pattern> {
+  bits<5> msb;
+  bits<5> lsb;
+  bits<5> rj;
+  bits<5> rd;
+
+  let Inst{31-21} = op{11-1};
+  let Inst{20-16} = msb;
+  let Inst{15} = op{0};
+  let Inst{14-10} = lsb;
+  let Inst{9-5} = rj;
+  let Inst{4-0} = rd;
+}
+
+// FmtBSTR_D
+// <opcode | msb | lsb | rj | rd>
+class FmtBSTR_D<bits<10> op, dag outs, dag ins, string asmstr,
+                list<dag> pattern = []> : LAInst<outs, ins, asmstr, pattern> {
+  bits<6> msb;
+  bits<6> lsb;
+  bits<5> rj;
+  bits<5> rd;
+
+  let Inst{31-22} = op;
+  let Inst{21-16} = msb;
+  let Inst{15-10} = lsb;
+  let Inst{9-5} = rj;
+  let Inst{4-0} = rd;
+}
+
+// FmtASRT
+// <opcode | rk | rj | 0x0>
+class FmtASRT<bits<17> op, dag outs, dag ins, string asmstr,
+              list<dag> pattern = []> : LAInst<outs, ins, asmstr, pattern> {
+  bits<5> rk;
+  bits<5> rj;
+
+  let Inst{31-15} = op;
+  let Inst{14-10} = rk;
+  let Inst{9-5} = rj;
+  let Inst{4-0} = 0x0;
+}
+
+// FmtPRELD
+// < 0b0010101011 | I12 | rj | I5>
+class FmtPRELD<dag outs, dag ins, string asmstr,
+               list<dag> pattern = []> : LAInst<outs, ins, asmstr, pattern> {
+  bits<12> imm12;
+  bits<5> rj;
+  bits<5> imm5;
+
+  let Inst{31-22} = 0b0010101011;
+  let Inst{21-10} = imm12;
+  let Inst{9-5} = rj;
+  let Inst{4-0} = imm5;
+}
+
+// FmtPRELDX
+// < 0b00111000001011000 | rk | rj | I5>
+class FmtPRELDX<dag outs, dag ins, string asmstr,
+                list<dag> pattern = []> : LAInst<outs, ins, asmstr, pattern> {
+  bits<5> rk;
+  bits<5> rj;
+  bits<5> imm5;
+
+  let Inst{31-15} = 0b00111000001011000;
+  let Inst{14-10} = rk;
+  let Inst{9-5} = rj;
+  let Inst{4-0} = imm5;
+}

llvm/lib/Target/LoongArch/LoongArchInstrInfo.h

+//=- LoongArchInstrInfo.h - LoongArch Instruction Information ---*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains the LoongArch implementation of the TargetInstrInfo class.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_TARGET_LOONGARCH_LOONGARCHINSTRINFO_H
+#define LLVM_LIB_TARGET_LOONGARCH_LOONGARCHINSTRINFO_H
+
+#include "llvm/CodeGen/TargetInstrInfo.h"
+
+#define GET_INSTRINFO_HEADER
+#include "LoongArchGenInstrInfo.inc"
+
+namespace llvm {
+
+class LoongArchSubtarget;
+
+class LoongArchInstrInfo : public LoongArchGenInstrInfo {
+  const LoongArchSubtarget &STI;
+
+public:
+  explicit LoongArchInstrInfo(LoongArchSubtarget &STI);
+};
+
+} // end namespace llvm
+#endif // LLVM_LIB_TARGET_LOONGARCH_LOONGARCHINSTRINFO_H

llvm/lib/Target/LoongArch/LoongArchInstrInfo.cpp

+//=- LoongArchInstrInfo.cpp - LoongArch Instruction Information -*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains the LoongArch implementation of the TargetInstrInfo class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "LoongArchInstrInfo.h"
+
+using namespace llvm;
+
+#define GET_INSTRINFO_CTOR_DTOR
+#include "LoongArchGenInstrInfo.inc"
+
+LoongArchInstrInfo::LoongArchInstrInfo(LoongArchSubtarget &STI)
+    // FIXME: add CFSetup and CFDestroy Inst when we implement function call.
+    : LoongArchGenInstrInfo(),
+
+      STI(STI) {}

llvm/lib/Target/LoongArch/LoongArchInstrInfo.td

+//== LoongArchInstrInfo.td - Target Description for LoongArch -*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file describes the LoongArch instructions in TableGen format.
+//
+//===----------------------------------------------------------------------===//
+
+//===----------------------------------------------------------------------===//
+// LoongArch specific DAG Nodes.
+//===----------------------------------------------------------------------===//
+
+// TODO: Add LoongArch specific DAG Nodes
+
+//===----------------------------------------------------------------------===//
+// Operand and SDNode transformation definitions.
+//===----------------------------------------------------------------------===//
+class ImmAsmOperand<string prefix, int width, string suffix> : AsmOperandClass {
+  let Name = prefix # "Imm" # width # suffix;
+  let DiagnosticType = !strconcat("Invalid", Name);
+}
+
+class SImmAsmOperand<int width, string suffix = "">
+    : ImmAsmOperand<"S", width, suffix> {
+}
+
+class UImmAsmOperand<int width, string suffix = "">
+    : ImmAsmOperand<"U", width, suffix> {
+}
+
+def uimm2 : Operand<GRLenVT>,
+            ImmLeaf<GRLenVT, [{return isUInt<2>(Imm);}]> {
+  let OperandType = "OPERAND_UIMM2";
+  let OperandNamespace = "LoongArchOP";
+}
+
+def uimm2_plus1 : Operand<GRLenVT>,
+                  ImmLeaf<GRLenVT, [{return isUInt<2>(Imm - 1);}]> {
+  let OperandType = "OPERAND_UIMM2_plus1";
+  let OperandNamespace = "LoongArchOP";
+}
+
+def uimm3 : Operand<GRLenVT>, ImmLeaf<GRLenVT, [{return isUInt<3>(Imm);}]> {
+  let OperandType = "OPERAND_UIMM3";
+  let OperandNamespace = "LoongArchOP";
+}
+
+def uimm5 : Operand<GRLenVT>, ImmLeaf<GRLenVT, [{return isUInt<5>(Imm);}]> {
+  let OperandType = "OPERAND_UIMM5";
+  let OperandNamespace = "LoongArchOP";
+}
+
+def uimm6 : Operand<GRLenVT>, ImmLeaf<GRLenVT, [{return isUInt<6>(Imm);}]> {
+  let OperandType = "OPERAND_UIMM6";
+  let OperandNamespace = "LoongArchOP";
+}
+
+def uimm12 : Operand<GRLenVT>, ImmLeaf<GRLenVT, [{return isUInt<12>(Imm);}]> {
+  let OperandType = "OPERAND_UIMM12";
+  let OperandNamespace = "LoongArchOP";
+}
+
+def uimm15 : Operand<GRLenVT>, ImmLeaf<GRLenVT, [{return isUInt<15>(Imm);}]>;
+
+def simm12 : Operand<GRLenVT>, ImmLeaf<GRLenVT, [{return isInt<12>(Imm);}]> {
+  let OperandType = "OPERAND_SIMM12";
+  let OperandNamespace = "LoongArchOP";
+}
+
+def simm14 : Operand<GRLenVT>, ImmLeaf<GRLenVT, [{return isInt<14>(Imm);}]>;
+
+def simm14_lsl2 : Operand<GRLenVT>;
+
+def simm16 : Operand<GRLenVT>, ImmLeaf<GRLenVT, [{return isInt<16>(Imm);}]> {
+  let OperandType = "OPERAND_SIMM16";
+  let OperandNamespace = "LoongArchOP";
+}
+
+def simm16_lsl2 : Operand<GRLenVT>;
+
+def simm20 : Operand<GRLenVT>, ImmLeaf<GRLenVT, [{return isInt<20>(Imm);}]> {
+  let OperandType = "OPERAND_SIMM20";
+  let OperandNamespace = "LoongArchOP";
+}
+
+def simm21_lsl2 : Operand<GRLenVT>;
+
+def simm26_lsl2 : Operand<GRLenVT>;
+
+//===----------------------------------------------------------------------===//
+// Instruction Formats
+//===----------------------------------------------------------------------===//
+
+include "LoongArchInstrFormats.td"
+
+//===----------------------------------------------------------------------===//
+// Instruction Class Templates
+//===----------------------------------------------------------------------===//
+class ALU_3R<bits<17> op, string opstr>
+    : Fmt3R<op, (outs GPR:$rd), (ins GPR:$rj, GPR:$rk),
+            !strconcat(opstr, "\t$rd, $rj, $rk")>;
+class ALU_2R<bits<22> op, string opstr>
+    : Fmt2R<op, (outs GPR:$rd), (ins GPR:$rj),
+            !strconcat(opstr, "\t$rd, $rj")>;
+
+class ALU_3RI2<bits<15> op, string opstr, Operand ImmOpnd>
+    : Fmt3RI2<op, (outs GPR:$rd), (ins GPR:$rj, GPR:$rk, ImmOpnd:$imm2),
+              !strconcat(opstr, "\t$rd, $rj, $rk, $imm2")>;
+class ALU_3RI3<bits<14> op, string opstr, Operand ImmOpnd>
+    : Fmt3RI3<op, (outs GPR:$rd), (ins GPR:$rj, GPR:$rk, ImmOpnd:$imm3),
+              !strconcat(opstr, "\t$rd, $rj, $rk, $imm3")>;
+class ALU_2RI5<bits<17> op, string opstr, Operand ImmOpnd>
+    : Fmt2RI5<op, (outs GPR:$rd), (ins GPR:$rj, ImmOpnd:$imm5),
+              !strconcat(opstr, "\t$rd, $rj, $imm5")>;
+class ALU_2RI6<bits<16> op, string opstr, Operand ImmOpnd>
+    : Fmt2RI6<op, (outs GPR:$rd), (ins GPR:$rj, ImmOpnd:$imm6),
+              !strconcat(opstr, "\t$rd, $rj, $imm6")>;
+class ALU_2RI12<bits<10> op, string opstr, Operand ImmOpnd>
+    : Fmt2RI12<op, (outs GPR:$rd), (ins GPR:$rj, ImmOpnd:$imm12),
+               !strconcat(opstr, "\t$rd, $rj, $imm12")>;
+class ALU_2RI16<bits<6> op, string opstr, Operand ImmOpnd>
+    : Fmt2RI16<op, (outs GPR:$rd), (ins GPR:$rj, ImmOpnd:$imm16),
+               !strconcat(opstr, "\t$rd, $rj, $imm16")>;
+class ALU_1RI20<bits<7> op, string opstr, Operand ImmOpnd>
+    : Fmt1RI20<op, (outs GPR:$rd), (ins ImmOpnd:$imm20),
+               !strconcat(opstr, "\t$rd, $imm20")>;
+
+class ALU_BSTRW<bits<12> op, string opstr, Operand ImmOpnd>
+    : FmtBSTR_W<op, (outs GPR:$rd), (ins GPR:$rj, ImmOpnd:$msb, ImmOpnd:$lsb),
+                !strconcat(opstr, "\t$rd, $rj, $msb, $lsb")>;
+class ALU_BSTRD<bits<10> op, string opstr, Operand ImmOpnd>
+    : FmtBSTR_D<op, (outs GPR:$rd), (ins GPR:$rj, ImmOpnd:$msb, ImmOpnd:$lsb),
+                !strconcat(opstr, "\t$rd, $rj, $msb, $lsb")>;
+
+class MISC_I15<bits<17> op, string opstr>
+    : FmtI15<op, (outs), (ins uimm15:$imm15), !strconcat(opstr, "\t$imm15")>;
+
+class RDTIME_2R<bits<22> op, string opstr>
+    : Fmt2R<op, (outs GPR:$rd, GPR:$rj), (ins),
+                 !strconcat(opstr, "\t$rd, $rj")>;
+
+class BrCC_2RI16<bits<6> op, string opstr>
+    : Fmt2RI16<op, (outs), (ins GPR:$rj, GPR:$rd, simm16_lsl2:$imm16),
+               !strconcat(opstr, "\t$rj, $rd, $imm16")> {
+  let isBranch = 1;
+  let isTerminator = 1;
+}
+class BrCCZ_1RI21<bits<6> op, string opstr>
+    : Fmt1RI21<op, (outs), (ins GPR:$rj, simm21_lsl2:$imm21),
+               !strconcat(opstr, "\t$rj, $imm21")> {
+  let isBranch = 1;
+  let isTerminator = 1;
+}
+class Br_I26<bits<6> op, string opstr>
+    : FmtI26<op, (outs), (ins simm26_lsl2:$imm26),
+             !strconcat(opstr, "\t$imm26")> {
+  let isBranch = 1;
+  let isTerminator = 1;
+}
+
+let mayLoad = 1 in {
+class LOAD_3R<bits<17> op, string opstr>
+    : Fmt3R<op, (outs GPR:$rd), (ins GPR:$rj, GPR:$rk),
+            !strconcat(opstr, "\t$rd, $rj, $rk")>;
+class LOAD_2RI12<bits<10> op, string opstr>
+    : Fmt2RI12<op, (outs GPR:$rd), (ins GPR:$rj, simm12:$imm12),
+               !strconcat(opstr, "\t$rd, $rj, $imm12")>;
+class LOAD_2RI14<bits<8> op, string opstr>
+    : Fmt2RI14<op, (outs GPR:$rd), (ins GPR:$rj, simm14_lsl2:$imm14),
+               !strconcat(opstr, "\t$rd, $rj, $imm14")>;
+} // mayLoad = 1
+
+let mayStore = 1 in {
+class STORE_3R<bits<17> op, string opstr>
+    : Fmt3R<op, (outs), (ins GPR:$rd, GPR:$rj, GPR:$rk),
+            !strconcat(opstr, "\t$rd, $rj, $rk")>;
+class STORE_2RI12<bits<10> op, string opstr>
+    : Fmt2RI12<op, (outs), (ins GPR:$rd, GPR:$rj, simm12:$imm12),
+               !strconcat(opstr, "\t$rd, $rj, $imm12")>;
+class STORE_2RI14<bits<8> op, string opstr>
+    : Fmt2RI14<op, (outs), (ins GPR:$rd, GPR:$rj, simm14_lsl2:$imm14),
+               !strconcat(opstr, "\t$rd, $rj, $imm14")>;
+} // mayStore = 1
+
+let mayLoad = 1, mayStore = 1 in
+class AM_3R<bits<17> op, string opstr>
+    : Fmt3R<op, (outs GPR:$rd), (ins GPR:$rj, GPR:$rk),
+            !strconcat(opstr, "\t$rd, $rj, $rk")>;
+
+let mayLoad = 1 in
+class LLBase<bits<8> op, string opstr>
+    : Fmt2RI14<op, (outs GPR:$rd), (ins GPR:$rj, simm14:$imm14),
+               !strconcat(opstr, "\t$rd, $rj, $imm14")>;
+
+let mayStore = 1, Constraints = "$rd = $dst" in
+class SCBase<bits<8> op, string opstr>
+    : Fmt2RI14<op, (outs GPR:$dst), (ins GPR:$rd, GPR:$rj, simm14:$imm14),
+               !strconcat(opstr, "\t$rd, $rj, $imm14")>;
+
+//===----------------------------------------------------------------------===//
+// Instructions
+//===----------------------------------------------------------------------===//
+
+// Arithmetic Operation Instructions
+def ADD_W : ALU_3R<0b00000000000100000, "add.w">;
+def SUB_W : ALU_3R<0b00000000000100010, "sub.w">;
+def ADDI_W : ALU_2RI12<0b0000001010, "addi.w", simm12>;
+def ALSL_W : ALU_3RI2<0b000000000000010, "alsl.w", uimm2_plus1>;
+def LU12I_W : ALU_1RI20<0b0001010, "lu12i.w", simm20>;
+def SLT  : ALU_3R<0b00000000000100100, "slt">;
+def SLTU : ALU_3R<0b00000000000100101, "sltu">;
+def SLTI  : ALU_2RI12<0b0000001000, "slti", simm12>;
+def SLTUI : ALU_2RI12<0b0000001001, "sltui", simm12>;
+def PCADDI    : ALU_1RI20<0b0001100, "pcaddi", simm20>;
+def PCADDU12I : ALU_1RI20<0b0001110, "pcaddu12i", simm20>;
+def PCALAU12I : ALU_1RI20<0b0001101, "pcalau12i", simm20>;
+def AND  : ALU_3R<0b00000000000101001, "and">;
+def OR   : ALU_3R<0b00000000000101010, "or">;
+def NOR  : ALU_3R<0b00000000000101000, "nor">;
+def XOR  : ALU_3R<0b00000000000101011, "xor">;
+def ANDN : ALU_3R<0b00000000000101101, "andn">;
+def ORN  : ALU_3R<0b00000000000101100, "orn">;
+def ANDI : ALU_2RI12<0b0000001101, "andi", uimm12>;
+def ORI  : ALU_2RI12<0b0000001110, "ori", uimm12>;
+def XORI : ALU_2RI12<0b0000001111, "xori", uimm12>;
+def MUL_W   : ALU_3R<0b00000000000111000, "mul.w">;
+def MULH_W  : ALU_3R<0b00000000000111001, "mulh.w">;
+def MULH_WU : ALU_3R<0b00000000000111010, "mulh.wu">;
+def DIV_W   : ALU_3R<0b00000000001000000, "div.w">;
+def MOD_W   : ALU_3R<0b00000000001000001, "mod.w">;
+def DIV_WU  : ALU_3R<0b00000000001000010, "div.wu">;
+def MOD_WU  : ALU_3R<0b00000000001000011, "mod.wu">;
+
+// Bit-shift Instructions
+def SLL_W  : ALU_3R<0b00000000000101110, "sll.w">;
+def SRL_W  : ALU_3R<0b00000000000101111, "srl.w">;
+def SRA_W  : ALU_3R<0b00000000000110000, "sra.w">;
+def ROTR_W : ALU_3R<0b00000000000110110, "rotr.w">;
+
+def SLLI_W  : ALU_2RI5<0b00000000010000001, "slli.w", uimm5>;
+def SRLI_W  : ALU_2RI5<0b00000000010001001, "srli.w", uimm5>;
+def SRAI_W  : ALU_2RI5<0b00000000010010001, "srai.w", uimm5>;
+def ROTRI_W : ALU_2RI5<0b00000000010011001, "rotri.w", uimm5>;
+
+// Bit-manipulation Instructions
+def EXT_W_B : ALU_2R<0b0000000000000000010111, "ext.w.b">;
+def EXT_W_H : ALU_2R<0b0000000000000000010110, "ext.w.h">;
+def CLO_W   : ALU_2R<0b0000000000000000000100, "clo.w">;
+def CLZ_W   : ALU_2R<0b0000000000000000000101, "clz.w">;
+def CTO_W   : ALU_2R<0b0000000000000000000110, "cto.w">;
+def CTZ_W   : ALU_2R<0b0000000000000000000111, "ctz.w">;
+def BYTEPICK_W : ALU_3RI2<0b000000000000100, "bytepick.w", uimm2>;
+def REVB_2H   : ALU_2R<0b0000000000000000001100, "revb.2h">;
+def BITREV_4B : ALU_2R<0b0000000000000000010010, "bitrev.4b">;
+def BITREV_W  : ALU_2R<0b0000000000000000010100, "bitrev.w">;
+def BSTRINS_W  : ALU_BSTRW<0b000000000110, "bstrins.w", uimm5>;
+def BSTRPICK_W : ALU_BSTRW<0b000000000111, "bstrpick.w", uimm5>;
+def MASKEQZ : ALU_3R<0b00000000000100110, "maskeqz">;
+def MASKNEZ : ALU_3R<0b00000000000100111, "masknez">;
+
+// Branch Instructions
+def BEQ  : BrCC_2RI16<0b010110, "beq">;
+def BNE  : BrCC_2RI16<0b010111, "bne">;
+def BLT  : BrCC_2RI16<0b011000, "blt">;
+def BGE  : BrCC_2RI16<0b011001, "bge">;
+def BLTU : BrCC_2RI16<0b011010, "bltu">;
+def BGEU : BrCC_2RI16<0b011011, "bgeu">;
+def BEQZ : BrCCZ_1RI21<0b010000, "beqz">;
+def BNEZ : BrCCZ_1RI21<0b010001, "bnez">;
+def B : Br_I26<0b010100, "b">;
+
+let isCall = 1 in
+def BL : FmtI26<0b010101, (outs), (ins simm26_lsl2:$imm26), "bl\t$imm26">;
+def JIRL : Fmt2RI16<0b010011, (outs GPR:$rd),
+                    (ins GPR:$rj, simm16_lsl2:$imm16),
+                    "jirl\t$rd, $rj, $imm16">;
+
+// Common Memory Access Instructions
+def LD_B  : LOAD_2RI12<0b0010100000, "ld.b">;
+def LD_H  : LOAD_2RI12<0b0010100001, "ld.h">;
+def LD_W  : LOAD_2RI12<0b0010100010, "ld.w">;
+def LD_BU : LOAD_2RI12<0b0010101000, "ld.bu">;
+def LD_HU : LOAD_2RI12<0b0010101001, "ld.hu">;
+def ST_B : STORE_2RI12<0b0010100100, "st.b">;
+def ST_H : STORE_2RI12<0b0010100101, "st.h">;
+def ST_W : STORE_2RI12<0b0010100110, "st.w">;
+def PRELD : FmtPRELD<(outs), (ins uimm5:$imm5, GPR:$rj, simm12:$imm12),
+                     "preld\t$imm5, $rj, $imm12">;
+
+// Atomic Memory Access Instructions
+def LL_W : LLBase<0b00100000, "ll.w">;
+def SC_W : SCBase<0b00100001, "sc.w">;
+
+// Barrier Instructions
+def DBAR : MISC_I15<0b00111000011100100, "dbar">;
+def IBAR : MISC_I15<0b00111000011100101, "ibar">;
+
+// Other Miscellaneous Instructions
+def SYSCALL : MISC_I15<0b00000000001010110, "syscall">;
+def BREAK   : MISC_I15<0b00000000001010100, "break">;
+def RDTIMEL_W : RDTIME_2R<0b0000000000000000011000, "rdtimel.w">;
+def RDTIMEH_W : RDTIME_2R<0b0000000000000000011001, "rdtimeh.w">;
+def CPUCFG : ALU_2R<0b0000000000000000011011, "cpucfg">;
+
+/// LA64 instructions
+let Predicates = [IsLA64] in {
+
+// Arithmetic Operation Instructions for 64-bits
+def ADD_D : ALU_3R<0b00000000000100001, "add.d">;
+def SUB_D : ALU_3R<0b00000000000100011, "sub.d">;
+def ADDI_D : ALU_2RI12<0b0000001011, "addi.d", simm12>;
+def ADDU16I_D : ALU_2RI16<0b000100, "addu16i.d", simm16>;
+def ALSL_WU : ALU_3RI2<0b000000000000011, "alsl.wu", uimm2_plus1>;
+def ALSL_D  : ALU_3RI2<0b000000000010110, "alsl.d", uimm2_plus1>;
+def LU32I_D : ALU_1RI20<0b0001011, "lu32i.d", simm20>;
+def LU52I_D : ALU_2RI12<0b0000001100, "lu52i.d", simm12>;
+def PCADDU18I : ALU_1RI20<0b0001111, "pcaddu18i", simm20>;
+def MUL_D     : ALU_3R<0b00000000000111011, "mul.d">;
+def MULH_D    : ALU_3R<0b00000000000111100, "mulh.d">;
+def MULH_DU   : ALU_3R<0b00000000000111101, "mulh.du">;
+def MULW_D_W  : ALU_3R<0b00000000000111110, "mulw.d.w">;
+def MULW_D_WU : ALU_3R<0b00000000000111111, "mulw.d.wu">;
+def DIV_D     : ALU_3R<0b00000000001000100, "div.d">;
+def MOD_D     : ALU_3R<0b00000000001000101, "mod.d">;
+def DIV_DU    : ALU_3R<0b00000000001000110, "div.du">;
+def MOD_DU    : ALU_3R<0b00000000001000111, "mod.du">;
+
+// Bit-shift Instructions for 64-bits
+def SLL_D  : ALU_3R<0b00000000000110001, "sll.d">;
+def SRL_D  : ALU_3R<0b00000000000110010, "srl.d">;
+def SRA_D  : ALU_3R<0b00000000000110011, "sra.d">;
+def ROTR_D : ALU_3R<0b00000000000110111, "rotr.d">;
+def SLLI_D  : ALU_2RI6<0b0000000001000001, "slli.d", uimm6>;
+def SRLI_D  : ALU_2RI6<0b0000000001000101, "srli.d", uimm6>;
+def SRAI_D  : ALU_2RI6<0b0000000001001001, "srai.d", uimm6>;
+def ROTRI_D : ALU_2RI6<0b0000000001001101, "rotri.d", uimm6>;
+
+// Bit-manipulation Instructions for 64-bits
+def CLO_D : ALU_2R<0b0000000000000000001000, "clo.d">;
+def CLZ_D : ALU_2R<0b0000000000000000001001, "clz.d">;
+def CTO_D : ALU_2R<0b0000000000000000001010, "cto.d">;
+def CTZ_D : ALU_2R<0b0000000000000000001011, "ctz.d">;
+def BYTEPICK_D : ALU_3RI3<0b00000000000011, "bytepick.d", uimm3>;
+def REVB_4H   : ALU_2R<0b0000000000000000001101, "revb.4h">;
+def REVB_2W   : ALU_2R<0b0000000000000000001110, "revb.2w">;
+def REVB_D    : ALU_2R<0b0000000000000000001111, "revb.d">;
+def REVH_2W   : ALU_2R<0b0000000000000000010000, "revh.2w">;
+def REVH_D    : ALU_2R<0b0000000000000000010001, "revh.d">;
+def BITREV_8B : ALU_2R<0b0000000000000000010011, "bitrev.8b">;
+def BITREV_D  : ALU_2R<0b0000000000000000010101, "bitrev.d">;
+def BSTRINS_D  : ALU_BSTRD<0b0000000010, "bstrins.d", uimm6>;
+def BSTRPICK_D : ALU_BSTRD<0b0000000011, "bstrpick.d", uimm6>;
+
+// Common Memory Access Instructions for 64-bits
+def LD_WU : LOAD_2RI12<0b0010101010, "ld.wu">;
+def ST_D : STORE_2RI12<0b0010100111, "st.d">;
+def LDX_B  : LOAD_3R<0b00111000000000000, "ldx.b">;
+def LDX_H  : LOAD_3R<0b00111000000001000, "ldx.h">;
+def LDX_W  : LOAD_3R<0b00111000000010000, "ldx.w">;
+def LDX_D  : LOAD_3R<0b00111000000011000, "ldx.d">;
+def LDX_BU : LOAD_3R<0b00111000001000000, "ldx.bu">;
+def LDX_HU : LOAD_3R<0b00111000001001000, "ldx.hu">;
+def LDX_WU : LOAD_3R<0b00111000001010000, "ldx.wu">;
+def STX_B : STORE_3R<0b00111000000100000, "stx.b">;
+def STX_H : STORE_3R<0b00111000000101000, "stx.h">;
+def STX_W : STORE_3R<0b00111000000110000, "stx.w">;
+def STX_D : STORE_3R<0b00111000000111000, "stx.d">;
+def LDPTR_W : LOAD_2RI14<0b00100100, "ldptr.w">;
+def LDPTR_D : LOAD_2RI14<0b00100110, "ldptr.d">;
+def STPTR_W : STORE_2RI14<0b00100101, "stptr.w">;
+def STPTR_D : STORE_2RI14<0b00100111, "stptr.d">;
+def PRELDX : FmtPRELDX<(outs), (ins uimm5:$imm5, GPR:$rj, GPR:$rk),
+                       "preldx\t$imm5, $rj, $rk">;
+
+// Bound Check Memory Access Instructions
+def LDGT_B : LOAD_3R<0b00111000011110000, "ldgt.b">;
+def LDGT_H : LOAD_3R<0b00111000011110001, "ldgt.h">;
+def LDGT_W : LOAD_3R<0b00111000011110010, "ldgt.w">;
+def LDGT_D : LOAD_3R<0b00111000011110011, "ldgt.d">;
+def LDLE_B : LOAD_3R<0b00111000011110100, "ldle.b">;
+def LDLE_H : LOAD_3R<0b00111000011110101, "ldle.h">;
+def LDLE_W : LOAD_3R<0b00111000011110110, "ldle.w">;
+def LDLE_D : LOAD_3R<0b00111000011110111, "ldle.d">;
+def STGT_B : STORE_3R<0b00111000011111000, "stgt.b">;
+def STGT_H : STORE_3R<0b00111000011111001, "stgt.h">;
+def STGT_W : STORE_3R<0b00111000011111010, "stgt.w">;
+def STGT_D : STORE_3R<0b00111000011111011, "stgt.d">;
+def STLE_B : STORE_3R<0b00111000011111100, "stle.b">;
+def STLE_H : STORE_3R<0b00111000011111101, "stle.h">;
+def STLE_W : STORE_3R<0b00111000011111110, "stle.w">;
+def STLE_D : STORE_3R<0b00111000011111111, "stle.d">;
+
+// Atomic Memory Access Instructions for 64-bits
+def AMSWAP_W    : AM_3R<0b00111000011000000, "amswap.w">;
+def AMSWAP_D    : AM_3R<0b00111000011000001, "amswap.d">;
+def AMADD_W     : AM_3R<0b00111000011000010, "amadd.w">;
+def AMADD_D     : AM_3R<0b00111000011000011, "amadd.d">;
+def AMAND_W     : AM_3R<0b00111000011000100, "amand.w">;
+def AMAND_D     : AM_3R<0b00111000011000101, "amand.d">;
+def AMOR_W      : AM_3R<0b00111000011000110, "amor.w">;
+def AMOR_D      : AM_3R<0b00111000011000111, "amor.d">;
+def AMXOR_W     : AM_3R<0b00111000011001000, "amxor.w">;
+def AMXOR_D     : AM_3R<0b00111000011001001, "amxor.d">;
+def AMMAX_W     : AM_3R<0b00111000011001010, "ammax.w">;
+def AMMAX_D     : AM_3R<0b00111000011001011, "ammax.d">;
+def AMMIN_W     : AM_3R<0b00111000011001100, "ammin.w">;
+def AMMIN_D     : AM_3R<0b00111000011001101, "ammin.d">;
+def AMMAX_WU    : AM_3R<0b00111000011001110, "ammax.wu">;
+def AMMAX_DU    : AM_3R<0b00111000011001111, "ammax.du">;
+def AMMIN_WU    : AM_3R<0b00111000011010000, "ammin.wu">;
+def AMMIN_DU    : AM_3R<0b00111000011010001, "ammin.du">;
+def AMSWAP_DB_W : AM_3R<0b00111000011010010, "amswap_db.w">;
+def AMSWAP_DB_D : AM_3R<0b00111000011010011, "amswap_db.d">;
+def AMADD_DB_W  : AM_3R<0b00111000011010100, "amadd_db.w">;
+def AMADD_DB_D  : AM_3R<0b00111000011010101, "amadd_db.d">;
+def AMAND_DB_W  : AM_3R<0b00111000011010110, "amand_db.w">;
+def AMAND_DB_D  : AM_3R<0b00111000011010111, "amand_db.d">;
+def AMOR_DB_W   : AM_3R<0b00111000011011000, "amor_db.w">;
+def AMOR_DB_D   : AM_3R<0b00111000011011001, "amor_db.d">;
+def AMXOR_DB_W  : AM_3R<0b00111000011011010, "amxor_db.w">;
+def AMXOR_DB_D  : AM_3R<0b00111000011011011, "amxor_db.d">;
+def AMMAX_DB_W  : AM_3R<0b00111000011011100, "ammax_db.w">;
+def AMMAX_DB_D  : AM_3R<0b00111000011011101, "ammax_db.d">;
+def AMMIN_DB_W  : AM_3R<0b00111000011011110, "ammin_db.w">;
+def AMMIN_DB_D  : AM_3R<0b00111000011011111, "ammin_db.d">;
+def AMMAX_DB_WU : AM_3R<0b00111000011100000, "ammax_db.wu">;
+def AMMAX_DB_DU : AM_3R<0b00111000011100001, "ammax_db.du">;
+def AMMIN_DB_WU : AM_3R<0b00111000011100010, "ammin_db.wu">;
+def AMMIN_DB_DU : AM_3R<0b00111000011100011, "ammin_db.du">;
+def LL_D : LLBase<0b00100010, "ll.d">;
+def SC_D : SCBase<0b00100011, "sc.d">;
+
+// CRC Check Instructions
+def CRC_W_B_W  : ALU_3R<0b00000000001001000, "crc.w.b.w">;
+def CRC_W_H_W  : ALU_3R<0b00000000001001001, "crc.w.h.w">;
+def CRC_W_W_W  : ALU_3R<0b00000000001001010, "crc.w.w.w">;
+def CRC_W_D_W  : ALU_3R<0b00000000001001011, "crc.w.d.w">;
+def CRCC_W_B_W : ALU_3R<0b00000000001001100, "crcc.w.b.w">;
+def CRCC_W_H_W : ALU_3R<0b00000000001001101, "crcc.w.h.w">;
+def CRCC_W_W_W : ALU_3R<0b00000000001001110, "crcc.w.w.w">;
+def CRCC_W_D_W : ALU_3R<0b00000000001001111, "crcc.w.d.w">;
+
+// Other Miscellaneous Instructions for 64-bits
+def ASRTLE_D : FmtASRT<0b00000000000000010, (outs), (ins GPR:$rj, GPR:$rk),
+                       "asrtle.d\t$rj, $rk">;
+def ASRTGT_D : FmtASRT<0b00000000000000011, (outs), (ins GPR:$rj, GPR:$rk),
+                       "asrtgt.d\t$rj, $rk">;
+def RDTIME_D : RDTIME_2R<0b0000000000000000011010, "rdtime.d">;
+} // Predicates = [IsLA64]
+
+//===----------------------------------------------------------------------===//
+// Pseudo-instructions and codegen patterns
+//
+// Naming convention: For 'generic' pattern classes, we use the naming
+// convention PatTy1Ty2.
+//===----------------------------------------------------------------------===//
+
+/// Generic pattern classes
+
+class PatGprGpr<SDPatternOperator OpNode, LAInst Inst>
+    : Pat<(OpNode GPR:$rj, GPR:$rk), (Inst GPR:$rj, GPR:$rk)>;
+class PatGprGpr_32<SDPatternOperator OpNode, LAInst Inst>
+    : Pat<(sext_inreg (OpNode GPR:$rj, GPR:$rk), i32), (Inst GPR:$rj, GPR:$rk)>;
+
+class PatGprImm<SDPatternOperator OpNode, LAInst Inst, Operand ImmOpnd>
+    : Pat<(OpNode GPR:$rj, ImmOpnd:$imm),
+          (Inst GPR:$rj, ImmOpnd:$imm)>;
+class PatGprImm_32<SDPatternOperator OpNode, LAInst Inst, Operand ImmOpnd>
+    : Pat<(sext_inreg (OpNode GPR:$rj, ImmOpnd:$imm), i32),
+          (Inst GPR:$rj, ImmOpnd:$imm)>;
+
+def : PatGprGpr<and, AND>;
+def : PatGprGpr<or, OR>;
+def : PatGprGpr<xor, XOR>;
+
+/// LA32 patterns
+let Predicates = [IsLA32] in {
+def : PatGprGpr<add, ADD_W>;
+def : PatGprImm<add, ADDI_W, simm12>;
+} // Predicates = [IsLA32]
+
+/// LA64 patterns
+let Predicates = [IsLA64] in {
+def : Pat<(sext_inreg GPR:$rj, i32), (ADDI_W GPR:$rj, 0)>;
+
+def : PatGprGpr<add, ADD_D>;
+def : PatGprGpr_32<add, ADD_W>;
+
+def : PatGprImm<add, ADDI_D, simm12>;
+def : PatGprImm_32<add, ADDI_W, simm12>;
+} // Predicates = [IsLA64]
+
+//===----------------------------------------------------------------------===//
+// Assembler Pseudo Instructions
+//===----------------------------------------------------------------------===//
+def : InstAlias<"nop", (ANDI R0, R0, 0)>;
+def : InstAlias<"move $dst, $src", (OR GPR:$dst, GPR:$src, R0)>;

llvm/lib/Target/LoongArch/LoongArchMCInstLower.cpp

+//=- LoongArchMCInstLower.cpp - Convert LoongArch MachineInstr to an MCInst -=//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains code to lower LoongArch MachineInstrs to their
+// corresponding MCInst records.
+//
+//===----------------------------------------------------------------------===//
+
+#include "LoongArch.h"
+#include "LoongArchSubtarget.h"
+#include "llvm/CodeGen/AsmPrinter.h"
+#include "llvm/CodeGen/MachineBasicBlock.h"
+#include "llvm/CodeGen/MachineInstr.h"
+#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace llvm;
+
+bool llvm::lowerLoongArchMachineOperandToMCOperand(const MachineOperand &MO,
+                                                   MCOperand &MCOp,
+                                                   const AsmPrinter &AP) {
+  switch (MO.getType()) {
+  default:
+    report_fatal_error(
+        "lowerLoongArchMachineOperandToMCOperand: unknown operand type");
+  case MachineOperand::MO_Register:
+    // Ignore all implicit register operands.
+    if (MO.isImplicit())
+      return false;
+    MCOp = MCOperand::createReg(MO.getReg());
+    break;
+  case MachineOperand::MO_RegisterMask:
+    // Regmasks are like implicit defs.
+    return false;
+  case MachineOperand::MO_Immediate:
+    MCOp = MCOperand::createImm(MO.getImm());
+    break;
+  // TODO: lower special operands
+  case MachineOperand::MO_MachineBasicBlock:
+  case MachineOperand::MO_GlobalAddress:
+  case MachineOperand::MO_BlockAddress:
+  case MachineOperand::MO_ExternalSymbol:
+  case MachineOperand::MO_ConstantPoolIndex:
+  case MachineOperand::MO_JumpTableIndex:
+    break;
+  }
+  return true;
+}
+
+bool llvm::lowerLoongArchMachineInstrToMCInst(const MachineInstr *MI,
+                                              MCInst &OutMI, AsmPrinter &AP) {
+  OutMI.setOpcode(MI->getOpcode());
+
+  for (const MachineOperand &MO : MI->operands()) {
+    MCOperand MCOp;
+    if (lowerLoongArchMachineOperandToMCOperand(MO, MCOp, AP))
+      OutMI.addOperand(MCOp);
+  }
+  return false;
+}

llvm/lib/Target/LoongArch/LoongArchMachineFunctionInfo.h

+//=- LoongArchMachineFunctionInfo.h - LoongArch machine function info -----===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file declares LoongArch-specific per-machine-function information.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_TARGET_LOONGARCH_LOONGARCHMACHINEFUNCTIONINFO_H
+#define LLVM_LIB_TARGET_LOONGARCH_LOONGARCHMACHINEFUNCTIONINFO_H
+
+#include "LoongArchSubtarget.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineFunction.h"
+
+namespace llvm {
+
+/// LoongArchMachineFunctionInfo - This class is derived from
+/// MachineFunctionInfo and contains private LoongArch-specific information for
+/// each MachineFunction.
+class LoongArchMachineFunctionInfo : public MachineFunctionInfo {
+private:
+  /// FrameIndex for start of varargs area
+  int VarArgsFrameIndex = 0;
+  /// Size of the save area used for varargs
+  int VarArgsSaveSize = 0;
+
+  /// Size of stack frame to save callee saved registers
+  unsigned CalleeSavedStackSize = 0;
+
+public:
+  LoongArchMachineFunctionInfo(const MachineFunction &MF) {}
+
+  int getVarArgsFrameIndex() const { return VarArgsFrameIndex; }
+  void setVarArgsFrameIndex(int Index) { VarArgsFrameIndex = Index; }
+
+  unsigned getVarArgsSaveSize() const { return VarArgsSaveSize; }
+  void setVarArgsSaveSize(int Size) { VarArgsSaveSize = Size; }
+
+  unsigned getCalleeSavedStackSize() const { return CalleeSavedStackSize; }
+  void setCalleeSavedStackSize(unsigned Size) { CalleeSavedStackSize = Size; }
+};
+
+} // end namespace llvm
+
+#endif // LLVM_LIB_TARGET_LOONGARCH_LOONGARCHMACHINEFUNCTIONINFO_H

llvm/lib/Target/LoongArch/LoongArchRegisterInfo.h

+//= LoongArchRegisterInfo.h - LoongArch Register Information Impl -*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains the LoongArch implementation of the TargetRegisterInfo
+// class.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_TARGET_LOONGARCH_LOONGARCHREGISTERINFO_H
+#define LLVM_LIB_TARGET_LOONGARCH_LOONGARCHREGISTERINFO_H
+
+#include "llvm/CodeGen/TargetRegisterInfo.h"
+
+#define GET_REGINFO_HEADER
+#include "LoongArchGenRegisterInfo.inc"
+
+namespace llvm {
+
+struct LoongArchRegisterInfo : public LoongArchGenRegisterInfo {
+
+  LoongArchRegisterInfo(unsigned HwMode);
+
+  const MCPhysReg *getCalleeSavedRegs(const MachineFunction *MF) const override;
+  const uint32_t *getCallPreservedMask(const MachineFunction &MF,
+                                       CallingConv::ID) const override;
+  const uint32_t *getNoPreservedMask() const override;
+
+  BitVector getReservedRegs(const MachineFunction &MF) const override;
+  bool isConstantPhysReg(MCRegister PhysReg) const override;
+
+  const TargetRegisterClass *
+  getPointerRegClass(const MachineFunction &MF,
+                     unsigned Kind = 0) const override {
+    return &LoongArch::GPRRegClass;
+  }
+
+  void eliminateFrameIndex(MachineBasicBlock::iterator MI, int SPAdj,
+                           unsigned FIOperandNum,
+                           RegScavenger *RS = nullptr) const override;
+
+  Register getFrameRegister(const MachineFunction &MF) const override;
+};
+} // namespace llvm
+
+#endif // LLVM_LIB_TARGET_LOONGARCH_LOONGARCHREGISTERINFO_H

llvm/lib/Target/LoongArch/LoongArchRegisterInfo.cpp

+//===- LoongArchRegisterInfo.cpp - LoongArch Register Information -*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains the LoongArch implementation of the TargetRegisterInfo
+// class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "LoongArchRegisterInfo.h"
+#include "LoongArch.h"
+#include "LoongArchSubtarget.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/RegisterScavenging.h"
+#include "llvm/CodeGen/TargetFrameLowering.h"
+#include "llvm/CodeGen/TargetInstrInfo.h"
+#include "llvm/Support/ErrorHandling.h"
+
+using namespace llvm;
+
+#define GET_REGINFO_TARGET_DESC
+#include "LoongArchGenRegisterInfo.inc"
+
+LoongArchRegisterInfo::LoongArchRegisterInfo(unsigned HwMode)
+    : LoongArchGenRegisterInfo(LoongArch::R1, /*DwarfFlavour*/ 0,
+                               /*EHFlavor*/ 0,
+                               /*PC*/ 0, HwMode) {}
+
+const MCPhysReg *
+LoongArchRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
+  auto &Subtarget = MF->getSubtarget<LoongArchSubtarget>();
+
+  switch (Subtarget.getTargetABI()) {
+  default:
+    llvm_unreachable("Unrecognized ABI");
+  case LoongArchABI::ABI_ILP32S:
+  case LoongArchABI::ABI_LP64S:
+    return CSR_ILP32S_LP64S_SaveList;
+  case LoongArchABI::ABI_ILP32F:
+  case LoongArchABI::ABI_LP64F:
+    return CSR_ILP32F_LP64F_SaveList;
+  case LoongArchABI::ABI_ILP32D:
+  case LoongArchABI::ABI_LP64D:
+    return CSR_ILP32D_LP64D_SaveList;
+  }
+}
+
+const uint32_t *
+LoongArchRegisterInfo::getCallPreservedMask(const MachineFunction &MF,
+                                            CallingConv::ID CC) const {
+  auto &Subtarget = MF.getSubtarget<LoongArchSubtarget>();
+
+  switch (Subtarget.getTargetABI()) {
+  default:
+    llvm_unreachable("Unrecognized ABI");
+  case LoongArchABI::ABI_ILP32S:
+  case LoongArchABI::ABI_LP64S:
+    return CSR_ILP32S_LP64S_RegMask;
+  case LoongArchABI::ABI_ILP32F:
+  case LoongArchABI::ABI_LP64F:
+    return CSR_ILP32F_LP64F_RegMask;
+  case LoongArchABI::ABI_ILP32D:
+  case LoongArchABI::ABI_LP64D:
+    return CSR_ILP32D_LP64D_RegMask;
+  }
+}
+
+const uint32_t *LoongArchRegisterInfo::getNoPreservedMask() const {
+  return CSR_NoRegs_RegMask;
+}
+
+BitVector
+LoongArchRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
+  const LoongArchFrameLowering *TFI = getFrameLowering(MF);
+  BitVector Reserved(getNumRegs());
+
+  // Use markSuperRegs to ensure any register aliases are also reserved
+  markSuperRegs(Reserved, LoongArch::R0);  // zero
+  markSuperRegs(Reserved, LoongArch::R2);  // tp
+  markSuperRegs(Reserved, LoongArch::R3);  // sp
+  markSuperRegs(Reserved, LoongArch::R21); // non-allocatable
+  if (TFI->hasFP(MF))
+    markSuperRegs(Reserved, LoongArch::R22); // fp
+  // Reserve the base register if we need to realign the stack and allocate
+  // variable-sized objects at runtime.
+  if (TFI->hasBP(MF))
+    markSuperRegs(Reserved, LoongArchABI::getBPReg()); // bp
+
+  assert(checkAllSuperRegsMarked(Reserved));
+  return Reserved;
+}
+
+bool LoongArchRegisterInfo::isConstantPhysReg(MCRegister PhysReg) const {
+  return PhysReg == LoongArch::R0;
+}
+
+Register
+LoongArchRegisterInfo::getFrameRegister(const MachineFunction &MF) const {
+  const TargetFrameLowering *TFI = getFrameLowering(MF);
+  return TFI->hasFP(MF) ? LoongArch::R22 : LoongArch::R3;
+}
+
+void LoongArchRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
+                                                int SPAdj,
+                                                unsigned FIOperandNum,
+                                                RegScavenger *RS) const {
+  assert(SPAdj == 0 && "Unexpected non-zero SPAdj value");
+  // TODO: Implement this when we have function calls
+}

llvm/lib/Target/LoongArch/LoongArchRegisterInfo.td

+//===-- LoongArchRegisterInfo.td - LoongArch Register defs -*- 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
+//
+//===----------------------------------------------------------------------===//
+
+//===----------------------------------------------------------------------===//
+//  Declarations that describe the LoongArch register files
+//===----------------------------------------------------------------------===//
+
+let Namespace = "LoongArch" in {
+class LoongArchReg<bits<16> Enc, string n, list<string> alt = []>
+    : Register<n> {
+  let HWEncoding = Enc;
+  let AltNames = alt;
+}
+
+class LoongArchReg32<bits<16> Enc, string n, list<string> alt = []>
+    : Register<n> {
+  let HWEncoding = Enc;
+  let AltNames = alt;
+}
+
+def sub_32 : SubRegIndex<32>;
+class LoongArchReg64<LoongArchReg32 subreg> : Register<""> {
+  let HWEncoding = subreg.HWEncoding;
+  let SubRegs = [subreg];
+  let SubRegIndices = [sub_32];
+  let AsmName = subreg.AsmName;
+  let AltNames = subreg.AltNames;
+}
+
+let FallbackRegAltNameIndex = NoRegAltName in
+def RegAliasName : RegAltNameIndex;
+} // Namespace = "LoongArch"
+
+// Integer registers
+
+let RegAltNameIndices = [RegAliasName] in {
+  def R0  : LoongArchReg<0,  "r0", ["zero"]>, DwarfRegNum<[0]>;
+  def R1  : LoongArchReg<1,  "r1", ["ra"]>, DwarfRegNum<[1]>;
+  def R2  : LoongArchReg<2,  "r2", ["tp"]>, DwarfRegNum<[2]>;
+  def R3  : LoongArchReg<3,  "r3", ["sp"]>, DwarfRegNum<[3]>;
+  def R4  : LoongArchReg<4,  "r4", ["a0"]>, DwarfRegNum<[4]>;
+  def R5  : LoongArchReg<5,  "r5", ["a1"]>, DwarfRegNum<[5]>;
+  def R6  : LoongArchReg<6,  "r6", ["a2"]>, DwarfRegNum<[6]>;
+  def R7  : LoongArchReg<7,  "r7", ["a3"]>, DwarfRegNum<[7]>;
+  def R8  : LoongArchReg<8,  "r8", ["a4"]>, DwarfRegNum<[8]>;
+  def R9  : LoongArchReg<9,  "r9", ["a5"]>, DwarfRegNum<[9]>;
+  def R10 : LoongArchReg<10, "r10", ["a6"]>, DwarfRegNum<[10]>;
+  def R11 : LoongArchReg<11, "r11", ["a7"]>, DwarfRegNum<[11]>;
+  def R12 : LoongArchReg<12, "r12", ["t0"]>, DwarfRegNum<[12]>;
+  def R13 : LoongArchReg<13, "r13", ["t1"]>, DwarfRegNum<[13]>;
+  def R14 : LoongArchReg<14, "r14", ["t2"]>, DwarfRegNum<[14]>;
+  def R15 : LoongArchReg<15, "r15", ["t3"]>, DwarfRegNum<[15]>;
+  def R16 : LoongArchReg<16, "r16", ["t4"]>, DwarfRegNum<[16]>;
+  def R17 : LoongArchReg<17, "r17", ["t5"]>, DwarfRegNum<[17]>;
+  def R18 : LoongArchReg<18, "r18", ["t6"]>, DwarfRegNum<[18]>;
+  def R19 : LoongArchReg<19, "r19", ["t7"]>, DwarfRegNum<[19]>;
+  def R20 : LoongArchReg<20, "r20", ["t8"]>, DwarfRegNum<[20]>;
+  def R21 : LoongArchReg<21, "r21", [""]>, DwarfRegNum<[21]>;
+  def R22 : LoongArchReg<22, "r22", ["fp", "s9"]>, DwarfRegNum<[22]>;
+  def R23 : LoongArchReg<23, "r23", ["s0"]>, DwarfRegNum<[23]>;
+  def R24 : LoongArchReg<24, "r24", ["s1"]>, DwarfRegNum<[24]>;
+  def R25 : LoongArchReg<25, "r25", ["s2"]>, DwarfRegNum<[25]>;
+  def R26 : LoongArchReg<26, "r26", ["s3"]>, DwarfRegNum<[26]>;
+  def R27 : LoongArchReg<27, "r27", ["s4"]>, DwarfRegNum<[27]>;
+  def R28 : LoongArchReg<28, "r28", ["s5"]>, DwarfRegNum<[28]>;
+  def R29 : LoongArchReg<29, "r29", ["s6"]>, DwarfRegNum<[29]>;
+  def R30 : LoongArchReg<30, "r30", ["s7"]>, DwarfRegNum<[30]>;
+  def R31 : LoongArchReg<31, "r31", ["s8"]>, DwarfRegNum<[31]>;
+} // RegAltNameIndices = [RegAliasName]
+
+def GRLenVT : ValueTypeByHwMode<[LA32, LA64],
+                                [i32,  i64]>;
+def GRLenRI : RegInfoByHwMode<
+      [LA32,              LA64],
+      [RegInfo<32,32,32>, RegInfo<64,64,64>]>;
+
+// The order of registers represents the preferred allocation sequence.
+// Registers are listed in the order caller-save, callee-save, specials.
+def GPR : RegisterClass<"LoongArch", [GRLenVT], 32, (add
+    // Argument registers (a0...a7)
+    (sequence "R%u", 4, 11),
+    // Temporary registers (t0...t8)
+    (sequence "R%u", 12, 20),
+    // Static register (s9/fp, s0...s8)
+    (sequence "R%u", 22, 31),
+    // Specials (r0, ra, tp, sp)
+    (sequence "R%u", 0, 3),
+    // Reserved (Non-allocatable)
+    R21
+  )> {
+  let RegInfos = GRLenRI;
+}
+
+// Floating point registers
+
+let RegAltNameIndices = [RegAliasName] in {
+  def F0  : LoongArchReg32<0, "f0", ["fa0"]>, DwarfRegNum<[32]>;
+  def F1  : LoongArchReg32<1, "f1", ["fa1"]>, DwarfRegNum<[33]>;
+  def F2  : LoongArchReg32<2, "f2", ["fa2"]>, DwarfRegNum<[34]>;
+  def F3  : LoongArchReg32<3, "f3", ["fa3"]>, DwarfRegNum<[35]>;
+  def F4  : LoongArchReg32<4, "f4", ["fa4"]>, DwarfRegNum<[36]>;
+  def F5  : LoongArchReg32<5, "f5", ["fa5"]>, DwarfRegNum<[37]>;
+  def F6  : LoongArchReg32<6, "f6", ["fa6"]>, DwarfRegNum<[38]>;
+  def F7  : LoongArchReg32<7, "f7", ["fa7"]>, DwarfRegNum<[39]>;
+  def F8  : LoongArchReg32<8, "f8", ["ft0"]>, DwarfRegNum<[40]>;
+  def F9  : LoongArchReg32<9, "f9", ["ft1"]>, DwarfRegNum<[41]>;
+  def F10 : LoongArchReg32<10,"f10", ["ft2"]>, DwarfRegNum<[42]>;
+  def F11 : LoongArchReg32<11,"f11", ["ft3"]>, DwarfRegNum<[43]>;
+  def F12 : LoongArchReg32<12,"f12", ["ft4"]>, DwarfRegNum<[44]>;
+  def F13 : LoongArchReg32<13,"f13", ["ft5"]>, DwarfRegNum<[45]>;
+  def F14 : LoongArchReg32<14,"f14", ["ft6"]>, DwarfRegNum<[46]>;
+  def F15 : LoongArchReg32<15,"f15", ["ft7"]>, DwarfRegNum<[47]>;
+  def F16 : LoongArchReg32<16,"f16", ["ft8"]>, DwarfRegNum<[48]>;
+  def F17 : LoongArchReg32<17,"f17", ["ft9"]>, DwarfRegNum<[49]>;
+  def F18 : LoongArchReg32<18,"f18", ["ft10"]>, DwarfRegNum<[50]>;
+  def F19 : LoongArchReg32<19,"f19", ["ft11"]>, DwarfRegNum<[51]>;
+  def F20 : LoongArchReg32<20,"f20", ["ft12"]>, DwarfRegNum<[52]>;
+  def F21 : LoongArchReg32<21,"f21", ["ft13"]>, DwarfRegNum<[53]>;
+  def F22 : LoongArchReg32<22,"f22", ["ft14"]>, DwarfRegNum<[54]>;
+  def F23 : LoongArchReg32<23,"f23", ["ft15"]>, DwarfRegNum<[55]>;
+  def F24 : LoongArchReg32<24,"f24", ["fs0"]>, DwarfRegNum<[56]>;
+  def F25 : LoongArchReg32<25,"f25", ["fs1"]>, DwarfRegNum<[57]>;
+  def F26 : LoongArchReg32<26,"f26", ["fs2"]>, DwarfRegNum<[58]>;
+  def F27 : LoongArchReg32<27,"f27", ["fs3"]>, DwarfRegNum<[59]>;
+  def F28 : LoongArchReg32<28,"f28", ["fs4"]>, DwarfRegNum<[60]>;
+  def F29 : LoongArchReg32<29,"f29", ["fs5"]>, DwarfRegNum<[61]>;
+  def F30 : LoongArchReg32<30,"f30", ["fs6"]>, DwarfRegNum<[62]>;
+  def F31 : LoongArchReg32<31,"f31", ["fs7"]>, DwarfRegNum<[63]>;
+
+  foreach I = 0-31 in {
+    def F#I#_64 : LoongArchReg64<!cast<LoongArchReg32>("F"#I)>,
+      DwarfRegNum<[!add(I, 32)]>;
+  }
+}
+
+// The order of registers represents the preferred allocation sequence.
+def FPR32 : RegisterClass<"LoongArch", [f32], 32, (sequence "F%u", 0, 31)>;
+def FPR64 : RegisterClass<"LoongArch", [f64], 64, (sequence "F%u_64", 0, 31)>;

llvm/lib/Target/LoongArch/LoongArchSubtarget.h

+//===- LoongArchSubtarget.h - Define Subtarget for the LoongArch -*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file declares the LoongArch specific subclass of TargetSubtargetInfo.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_TARGET_LOONGARCH_LOONGARCHSUBTARGET_H
+#define LLVM_LIB_TARGET_LOONGARCH_LOONGARCHSUBTARGET_H
+
+#include "LoongArchFrameLowering.h"
+#include "LoongArchISelLowering.h"
+#include "LoongArchInstrInfo.h"
+#include "LoongArchRegisterInfo.h"
+#include "MCTargetDesc/LoongArchBaseInfo.h"
+#include "llvm/CodeGen/SelectionDAGTargetInfo.h"
+#include "llvm/CodeGen/TargetSubtargetInfo.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/Target/TargetMachine.h"
+
+#define GET_SUBTARGETINFO_HEADER
+#include "LoongArchGenSubtargetInfo.inc"
+
+namespace llvm {
+class StringRef;
+
+class LoongArchSubtarget : public LoongArchGenSubtargetInfo {
+  virtual void anchor();
+  bool HasLA64 = false;
+  bool HasBasicF = false;
+  bool HasBasicD = false;
+  bool HasExtLSX = false;
+  bool HasExtLASX = false;
+  bool HasExtLVZ = false;
+  bool HasExtLBT = false;
+  unsigned GRLen = 32;
+  MVT GRLenVT = MVT::i32;
+  LoongArchABI::ABI TargetABI = LoongArchABI::ABI_Unknown;
+  LoongArchFrameLowering FrameLowering;
+  LoongArchInstrInfo InstrInfo;
+  LoongArchRegisterInfo RegInfo;
+  LoongArchTargetLowering TLInfo;
+
+  /// Initializes using the passed in CPU and feature strings so that we can
+  /// use initializer lists for subtarget initialization.
+  LoongArchSubtarget &initializeSubtargetDependencies(const Triple &TT,
+                                                      StringRef CPU,
+                                                      StringRef TuneCPU,
+                                                      StringRef FS,
+                                                      StringRef ABIName);
+
+public:
+  // Initializes the data members to match that of the specified triple.
+  LoongArchSubtarget(const Triple &TT, StringRef CPU, StringRef TuneCPU,
+                     StringRef FS, StringRef ABIName, const TargetMachine &TM);
+
+  // Parses features string setting specified subtarget options. The
+  // definition of this function is auto-generated by tblgen.
+  void ParseSubtargetFeatures(StringRef CPU, StringRef TuneCPU, StringRef FS);
+
+  const LoongArchFrameLowering *getFrameLowering() const override {
+    return &FrameLowering;
+  }
+  const LoongArchInstrInfo *getInstrInfo() const override { return &InstrInfo; }
+  const LoongArchRegisterInfo *getRegisterInfo() const override {
+    return &RegInfo;
+  }
+  const LoongArchTargetLowering *getTargetLowering() const override {
+    return &TLInfo;
+  }
+  bool is64Bit() const { return HasLA64; }
+  bool hasBasicF() const { return HasBasicF; }
+  bool hasBasicD() const { return HasBasicD; }
+  bool hasExtLSX() const { return HasExtLSX; }
+  bool hasExtLASX() const { return HasExtLASX; }
+  bool hasExtLVZ() const { return HasExtLVZ; }
+  bool hasExtLBT() const { return HasExtLBT; }
+  MVT getGRLenVT() const { return GRLenVT; }
+  unsigned getGRLen() const { return GRLen; }
+  LoongArchABI::ABI getTargetABI() const { return TargetABI; }
+};
+} // namespace llvm
+
+#endif // LLVM_LIB_TARGET_LOONGARCH_LOONGARCHSUBTARGET_H

llvm/lib/Target/LoongArch/LoongArchSubtarget.cpp

+//===-- LoongArchSubtarget.cpp - LoongArch Subtarget Information -*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the LoongArch specific subclass of TargetSubtargetInfo.
+//
+//===----------------------------------------------------------------------===//
+
+#include "LoongArchSubtarget.h"
+#include "LoongArchFrameLowering.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "loongarch-subtarget"
+
+#define GET_SUBTARGETINFO_TARGET_DESC
+#define GET_SUBTARGETINFO_CTOR
+#include "LoongArchGenSubtargetInfo.inc"
+
+void LoongArchSubtarget::anchor() {}
+
+LoongArchSubtarget &LoongArchSubtarget::initializeSubtargetDependencies(
+    const Triple &TT, StringRef CPU, StringRef TuneCPU, StringRef FS,
+    StringRef ABIName) {
+  bool Is64Bit = TT.isArch64Bit();
+  if (CPU.empty())
+    CPU = Is64Bit ? "generic-la64" : "generic-la32";
+
+  if (TuneCPU.empty())
+    TuneCPU = CPU;
+
+  ParseSubtargetFeatures(CPU, TuneCPU, FS);
+  if (Is64Bit) {
+    GRLenVT = MVT::i64;
+    GRLen = 64;
+  }
+
+  // TODO: ILP32{S,F} LP64{S,F}
+  TargetABI = Is64Bit ? LoongArchABI::ABI_LP64D : LoongArchABI::ABI_ILP32D;
+  return *this;
+}
+
+LoongArchSubtarget::LoongArchSubtarget(const Triple &TT, StringRef CPU,
+                                       StringRef TuneCPU, StringRef FS,
+                                       StringRef ABIName,
+                                       const TargetMachine &TM)
+    : LoongArchGenSubtargetInfo(TT, CPU, TuneCPU, FS),
+      FrameLowering(
+          initializeSubtargetDependencies(TT, CPU, TuneCPU, FS, ABIName)),
+      InstrInfo(*this), RegInfo(getHwMode()), TLInfo(TM, *this) {}

llvm/lib/Target/LoongArch/LoongArchTargetMachine.h

 //=- LoongArchTargetMachine.h - Define TargetMachine for LoongArch -*- 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
 //
 //===----------------------------------------------------------------------===//
 //
 // This file declares the LoongArch specific subclass of TargetMachine.
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_LIB_TARGET_LOONGARCH_LOONGARCHTARGETMACHINE_H
 #define LLVM_LIB_TARGET_LOONGARCH_LOONGARCHTARGETMACHINE_H
 
+#include "LoongArchSubtarget.h"
 #include "llvm/Target/TargetMachine.h"
 
 namespace llvm {
 
 class LoongArchTargetMachine : public LLVMTargetMachine {
+  std::unique_ptr<TargetLoweringObjectFile> TLOF;
+  mutable StringMap<std::unique_ptr<LoongArchSubtarget>> SubtargetMap;
 
 public:
   LoongArchTargetMachine(const Target &T, const Triple &TT, StringRef CPU,
                          StringRef FS, const TargetOptions &Options,
                          Optional<Reloc::Model> RM,
                          Optional<CodeModel::Model> CM, CodeGenOpt::Level OL,
                          bool JIT);
   ~LoongArchTargetMachine() override;
+
+  const LoongArchSubtarget *getSubtargetImpl(const Function &F) const override;
+  const LoongArchSubtarget *getSubtargetImpl() const = delete;
+
+  // Pass Pipeline Configuration
+  TargetPassConfig *createPassConfig(PassManagerBase &PM) override;
+
+  TargetLoweringObjectFile *getObjFileLowering() const override {
+    return TLOF.get();
+  }
 };
 
 } // end namespace llvm
 
 #endif // LLVM_LIB_TARGET_LOONGARCH_LOONGARCHTARGETMACHINE_H

llvm/lib/Target/LoongArch/LoongArchTargetMachine.cpp

 //===-- LoongArchTargetMachine.cpp - Define TargetMachine for LoongArch ---===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 //
 // Implements the info about LoongArch target spec.
 //
 //===----------------------------------------------------------------------===//
 
 #include "LoongArchTargetMachine.h"
+#include "LoongArch.h"
+#include "MCTargetDesc/LoongArchBaseInfo.h"
 #include "TargetInfo/LoongArchTargetInfo.h"
+#include "llvm/CodeGen/Passes.h"
+#include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
+#include "llvm/CodeGen/TargetPassConfig.h"
 #include "llvm/MC/TargetRegistry.h"
 
 using namespace llvm;
 
 #define DEBUG_TYPE "loongarch"
 
 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeLoongArchTarget() {
   // Register the target.

 }
 
 LoongArchTargetMachine::LoongArchTargetMachine(
     const Target &T, const Triple &TT, StringRef CPU, StringRef FS,
     const TargetOptions &Options, Optional<Reloc::Model> RM,
     Optional<CodeModel::Model> CM, CodeGenOpt::Level OL, bool JIT)
     : LLVMTargetMachine(T, computeDataLayout(TT), TT, CPU, FS, Options,
                         getEffectiveRelocModel(TT, RM),
-                        getEffectiveCodeModel(CM, CodeModel::Small), OL) {
+                        getEffectiveCodeModel(CM, CodeModel::Small), OL),
+      TLOF(std::make_unique<TargetLoweringObjectFileELF>()) {
   initAsmInfo();
 }
 
 LoongArchTargetMachine::~LoongArchTargetMachine() = default;
+
+const LoongArchSubtarget *
+LoongArchTargetMachine::getSubtargetImpl(const Function &F) const {
+  Attribute CPUAttr = F.getFnAttribute("target-cpu");
+  Attribute TuneAttr = F.getFnAttribute("tune-cpu");
+  Attribute FSAttr = F.getFnAttribute("target-features");
+
+  std::string CPU =
+      CPUAttr.isValid() ? CPUAttr.getValueAsString().str() : TargetCPU;
+  std::string TuneCPU =
+      TuneAttr.isValid() ? TuneAttr.getValueAsString().str() : CPU;
+  std::string FS =
+      FSAttr.isValid() ? FSAttr.getValueAsString().str() : TargetFS;
+
+  std::string Key = CPU + TuneCPU + FS;
+  auto &I = SubtargetMap[Key];
+  if (!I) {
+    // This needs to be done before we create a new subtarget since any
+    // creation will depend on the TM and the code generation flags on the
+    // function that reside in TargetOptions.
+    resetTargetOptions(F);
+    auto ABIName = Options.MCOptions.getABIName();
+    if (const MDString *ModuleTargetABI = dyn_cast_or_null<MDString>(
+            F.getParent()->getModuleFlag("target-abi"))) {
+      auto TargetABI = LoongArchABI::getTargetABI(ABIName);
+      if (TargetABI != LoongArchABI::ABI_Unknown &&
+          ModuleTargetABI->getString() != ABIName) {
+        report_fatal_error("-target-abi option != target-abi module flag");
+      }
+      ABIName = ModuleTargetABI->getString();
+    }
+    I = std::make_unique<LoongArchSubtarget>(TargetTriple, CPU, TuneCPU, FS,
+                                             ABIName, *this);
+  }
+  return I.get();
+}
+
+namespace {
+class LoongArchPassConfig : public TargetPassConfig {
+public:
+  LoongArchPassConfig(LoongArchTargetMachine &TM, PassManagerBase &PM)
+      : TargetPassConfig(TM, PM) {}
+
+  LoongArchTargetMachine &getLoongArchTargetMachine() const {
+    return getTM<LoongArchTargetMachine>();
+  }
+
+  bool addInstSelector() override;
+};
+} // namespace
+
+TargetPassConfig *
+LoongArchTargetMachine::createPassConfig(PassManagerBase &PM) {
+  return new LoongArchPassConfig(*this, PM);
+}
+
+bool LoongArchPassConfig::addInstSelector() {
+  addPass(createLoongArchISelDag(getLoongArchTargetMachine()));
+
+  return false;
+}

llvm/lib/Target/LoongArch/MCTargetDesc/CMakeLists.txt

 add_llvm_component_library(LLVMLoongArchDesc
+  LoongArchAsmBackend.cpp
+  LoongArchBaseInfo.cpp
+  LoongArchELFObjectWriter.cpp
+  LoongArchInstPrinter.cpp
+  LoongArchMCAsmInfo.cpp
   LoongArchMCTargetDesc.cpp
+  LoongArchMCCodeEmitter.cpp
 
   LINK_COMPONENTS
   MC
   LoongArchInfo
   Support
 
   ADD_TO_COMPONENT
   LoongArch
   )

llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchAsmBackend.h

+//===-- LoongArchAsmBackend.h - LoongArch Assembler Backend ---*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the LoongArchAsmBackend class.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_TARGET_LOONGARCH_MCTARGETDESC_LOONGARCHASMBACKEND_H
+#define LLVM_LIB_TARGET_LOONGARCH_MCTARGETDESC_LOONGARCHASMBACKEND_H
+
+#include "MCTargetDesc/LoongArchBaseInfo.h"
+#include "MCTargetDesc/LoongArchMCTargetDesc.h"
+#include "llvm/MC/MCAsmBackend.h"
+#include "llvm/MC/MCFixupKindInfo.h"
+
+namespace llvm {
+
+class LoongArchAsmBackend : public MCAsmBackend {
+  const MCSubtargetInfo &STI;
+  uint8_t OSABI;
+  bool Is64Bit;
+
+public:
+  LoongArchAsmBackend(const MCSubtargetInfo &STI, uint8_t OSABI, bool Is64Bit)
+      : MCAsmBackend(support::little), STI(STI), OSABI(OSABI),
+        Is64Bit(Is64Bit) {}
+  ~LoongArchAsmBackend() override {}
+
+  void applyFixup(const MCAssembler &Asm, const MCFixup &Fixup,
+                  const MCValue &Target, MutableArrayRef<char> Data,
+                  uint64_t Value, bool IsResolved,
+                  const MCSubtargetInfo *STI) const override;
+
+  bool shouldForceRelocation(const MCAssembler &Asm, const MCFixup &Fixup,
+                             const MCValue &Target) override;
+
+  bool fixupNeedsRelaxation(const MCFixup &Fixup, uint64_t Value,
+                            const MCRelaxableFragment *DF,
+                            const MCAsmLayout &Layout) const override {
+    return false;
+  }
+
+  unsigned getNumFixupKinds() const override {
+    // FIXME: Implement this when we define fixup kind
+    return 0;
+  }
+
+  void relaxInstruction(MCInst &Inst,
+                        const MCSubtargetInfo &STI) const override {}
+
+  bool writeNopData(raw_ostream &OS, uint64_t Count,
+                    const MCSubtargetInfo *STI) const override;
+
+  std::unique_ptr<MCObjectTargetWriter>
+  createObjectTargetWriter() const override;
+};
+} // namespace llvm
+
+#endif // LLVM_LIB_TARGET_LOONGARCH_MCTARGETDESC_LOONGARCHASMBACKEND_H

llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchAsmBackend.cpp

+//===-- LoongArchAsmBackend.cpp - LoongArch Assembler Backend -*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the LoongArchAsmBackend class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "LoongArchAsmBackend.h"
+#include "llvm/MC/MCAsmLayout.h"
+#include "llvm/MC/MCAssembler.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCELFObjectWriter.h"
+#include "llvm/Support/Endian.h"
+#include "llvm/Support/EndianStream.h"
+
+#define DEBUG_TYPE "loongarch-asmbackend"
+
+using namespace llvm;
+
+void LoongArchAsmBackend::applyFixup(const MCAssembler &Asm,
+                                     const MCFixup &Fixup,
+                                     const MCValue &Target,
+                                     MutableArrayRef<char> Data, uint64_t Value,
+                                     bool IsResolved,
+                                     const MCSubtargetInfo *STI) const {
+  // TODO: Apply the Value for given Fixup into the provided data fragment.
+  return;
+}
+
+bool LoongArchAsmBackend::shouldForceRelocation(const MCAssembler &Asm,
+                                                const MCFixup &Fixup,
+                                                const MCValue &Target) {
+  // TODO: Determine which relocation require special processing at linking
+  // time.
+  return false;
+}
+
+bool LoongArchAsmBackend::writeNopData(raw_ostream &OS, uint64_t Count,
+                                       const MCSubtargetInfo *STI) const {
+  // Check for byte count not multiple of instruction word size
+  if (Count % 4 != 0)
+    return false;
+
+  // The nop on LoongArch is andi r0, r0, 0.
+  for (; Count >= 4; Count -= 4)
+    support::endian::write<uint32_t>(OS, 0x03400000, support::little);
+
+  return true;
+}
+
+std::unique_ptr<MCObjectTargetWriter>
+LoongArchAsmBackend::createObjectTargetWriter() const {
+  return createLoongArchELFObjectWriter(OSABI, Is64Bit);
+}
+
+MCAsmBackend *llvm::createLoongArchAsmBackend(const Target &T,
+                                              const MCSubtargetInfo &STI,
+                                              const MCRegisterInfo &MRI,
+                                              const MCTargetOptions &Options) {
+  const Triple &TT = STI.getTargetTriple();
+  uint8_t OSABI = MCELFObjectTargetWriter::getOSABI(TT.getOS());
+  return new LoongArchAsmBackend(STI, OSABI, TT.isArch64Bit());
+}

llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchBaseInfo.h

+//=- LoongArchBaseInfo.h - Top level definitions for LoongArch MC -*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains small standalone enum definitions and helper function
+// definitions for the LoongArch target useful for the compiler back-end and the
+// MC libraries.
+//
+//===----------------------------------------------------------------------===//
+#ifndef LLVM_LIB_TARGET_LOONGARCH_MCTARGETDESC_LOONGARCHBASEINFO_H
+#define LLVM_LIB_TARGET_LOONGARCH_MCTARGETDESC_LOONGARCHBASEINFO_H
+
+#include "MCTargetDesc/LoongArchMCTargetDesc.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/StringSwitch.h"
+#include "llvm/MC/MCInstrDesc.h"
+#include "llvm/MC/SubtargetFeature.h"
+
+namespace llvm {
+
+namespace LoongArchOP {
+enum OperandType : unsigned {
+  OPERAND_FIRST_LOONGARCH_IMM = MCOI::OPERAND_FIRST_TARGET,
+  OPERAND_UIMM2 = OPERAND_FIRST_LOONGARCH_IMM,
+  OPERAND_UIMM2_plus1,
+  OPERAND_UIMM3,
+  OPERAND_UIMM5,
+  OPERAND_UIMM6,
+  OPERAND_UIMM12,
+  OPERAND_SIMM12,
+  OPERAND_SIMM16,
+  OPERAND_SIMM20,
+  OPERAND_LAST_LOONGARCH_IMM = OPERAND_SIMM20,
+};
+} // namespace LoongArchOP
+
+namespace LoongArchABI {
+enum ABI {
+  ABI_ILP32S,
+  ABI_ILP32F,
+  ABI_ILP32D,
+  ABI_LP64S,
+  ABI_LP64F,
+  ABI_LP64D,
+  ABI_Unknown
+};
+
+ABI getTargetABI(StringRef ABIName);
+
+// Returns the register used to hold the stack pointer after realignment.
+MCRegister getBPReg();
+} // namespace LoongArchABI
+
+} // namespace llvm
+
+#endif // LLVM_LIB_TARGET_LOONGARCH_MCTARGETDESC_LOONGARCHBASEINFO_H

llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchBaseInfo.cpp

+//= LoongArchBaseInfo.cpp - Top level definitions for LoongArch MC -*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements helper functions for the LoongArch target useful for the
+// compiler back-end and the MC libraries.
+//
+//===----------------------------------------------------------------------===//
+
+#include "LoongArchBaseInfo.h"
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/Triple.h"
+#include "llvm/MC/MCSubtargetInfo.h"
+
+namespace llvm {
+
+namespace LoongArchABI {
+
+ABI getTargetABI(StringRef ABIName) {
+  auto TargetABI = StringSwitch<ABI>(ABIName)
+                       .Case("ilp32s", ABI_ILP32S)
+                       .Case("ilp32f", ABI_ILP32F)
+                       .Case("ilp32d", ABI_ILP32D)
+                       .Case("lp64s", ABI_LP64S)
+                       .Case("lp64f", ABI_LP64F)
+                       .Case("lp64d", ABI_LP64D)
+                       .Default(ABI_Unknown);
+  return TargetABI;
+}
+
+// FIXME: other register?
+MCRegister getBPReg() { return LoongArch::R31; }
+
+} // namespace LoongArchABI
+
+} // namespace llvm

llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchELFObjectWriter.cpp

+//===-- LoongArchELFObjectWriter.cpp - LoongArch ELF Writer ---*- 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "MCTargetDesc/LoongArchMCTargetDesc.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCELFObjectWriter.h"
+#include "llvm/MC/MCFixup.h"
+#include "llvm/MC/MCObjectWriter.h"
+#include "llvm/Support/ErrorHandling.h"
+
+using namespace llvm;
+
+namespace {
+class LoongArchELFObjectWriter : public MCELFObjectTargetWriter {
+public:
+  LoongArchELFObjectWriter(uint8_t OSABI, bool Is64Bit);
+
+  ~LoongArchELFObjectWriter() override;
+
+  // Return true if the given relocation must be with a symbol rather than
+  // section plus offset.
+  bool needsRelocateWithSymbol(const MCSymbol &Sym,
+                               unsigned Type) const override {
+    return true;
+  }
+
+protected:
+  unsigned getRelocType(MCContext &Ctx, const MCValue &Target,
+                        const MCFixup &Fixup, bool IsPCRel) const override;
+};
+} // namespace
+
+LoongArchELFObjectWriter::LoongArchELFObjectWriter(uint8_t OSABI, bool Is64Bit)
+    : MCELFObjectTargetWriter(Is64Bit, OSABI, ELF::EM_LOONGARCH,
+                              /*HasRelocationAddend*/ true) {}
+
+LoongArchELFObjectWriter::~LoongArchELFObjectWriter() {}
+
+unsigned LoongArchELFObjectWriter::getRelocType(MCContext &Ctx,
+                                                const MCValue &Target,
+                                                const MCFixup &Fixup,
+                                                bool IsPCRel) const {
+  const MCExpr *Expr = Fixup.getValue();
+  // Determine the type of the relocation
+  unsigned Kind = Fixup.getTargetKind();
+
+  if (Kind >= FirstLiteralRelocationKind)
+    return Kind - FirstLiteralRelocationKind;
+
+  switch (Kind) {
+  // TODO: Implement this when we defined fixup kind.
+  default:
+    return ELF::R_LARCH_NONE;
+  }
+}
+
+std::unique_ptr<MCObjectTargetWriter>
+llvm::createLoongArchELFObjectWriter(uint8_t OSABI, bool Is64Bit) {
+  return std::make_unique<LoongArchELFObjectWriter>(OSABI, Is64Bit);
+}

llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchInstPrinter.h

+//===-- LoongArchInstPrinter.h - Convert LoongArch MCInst to asm syntax ---===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This class prints a LoongArch MCInst to a .s file.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_TARGET_LOONGARCH_MCTARGETDESC_LOONGARCHINSTPRINTER_H
+#define LLVM_LIB_TARGET_LOONGARCH_MCTARGETDESC_LOONGARCHINSTPRINTER_H
+
+#include "MCTargetDesc/LoongArchMCTargetDesc.h"
+#include "llvm/MC/MCInstPrinter.h"
+
+namespace llvm {
+
+class LoongArchInstPrinter : public MCInstPrinter {
+public:
+  LoongArchInstPrinter(const MCAsmInfo &MAI, const MCInstrInfo &MII,
+                       const MCRegisterInfo &MRI)
+      : MCInstPrinter(MAI, MII, MRI) {}
+
+  void printInst(const MCInst *MI, uint64_t Address, StringRef Annot,
+                 const MCSubtargetInfo &STI, raw_ostream &O) override;
+  void printRegName(raw_ostream &O, unsigned RegNo) const override;
+
+  // Autogenerated by tblgen.
+  std::pair<const char *, uint64_t> getMnemonic(const MCInst *MI) override;
+  void printInstruction(const MCInst *MI, uint64_t Address,
+                        const MCSubtargetInfo &STI, raw_ostream &O);
+  bool printAliasInstr(const MCInst *MI, uint64_t Address,
+                       const MCSubtargetInfo &STI, raw_ostream &O);
+  void printCustomAliasOperand(const MCInst *MI, uint64_t Address,
+                               unsigned OpIdx, unsigned PrintMethodIdx,
+                               const MCSubtargetInfo &STI, raw_ostream &O);
+  static const char *getRegisterName(unsigned RegNo);
+  static const char *getRegisterName(unsigned RegNo, unsigned AltIdx);
+
+private:
+  void printOperand(const MCInst *MI, unsigned OpNo, const MCSubtargetInfo &STI,
+                    raw_ostream &O);
+};
+} // namespace llvm
+
+#endif // LLVM_LIB_TARGET_LOONGARCH_MCTARGETDESC_LOONGARCHINSTPRINTER_H

llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchInstPrinter.cpp

+//===- LoongArchInstPrinter.cpp - Convert LoongArch MCInst to asm syntax --===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This class prints an LoongArch MCInst to a .s file.
+//
+//===----------------------------------------------------------------------===//
+
+#include "LoongArchInstPrinter.h"
+#include "LoongArchBaseInfo.h"
+#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/MC/MCInst.h"
+#include "llvm/MC/MCRegisterInfo.h"
+#include "llvm/MC/MCSubtargetInfo.h"
+#include "llvm/MC/MCSymbol.h"
+using namespace llvm;
+
+#define DEBUG_TYPE "loongarch-asm-printer"
+
+// Include the auto-generated portion of the assembly writer.
+#define PRINT_ALIAS_INSTR
+#include "LoongArchGenAsmWriter.inc"
+
+void LoongArchInstPrinter::printInst(const MCInst *MI, uint64_t Address,
+                                     StringRef Annot,
+                                     const MCSubtargetInfo &STI,
+                                     raw_ostream &O) {
+  if (!printAliasInstr(MI, Address, STI, O))
+    printInstruction(MI, Address, STI, O);
+  printAnnotation(O, Annot);
+}
+
+void LoongArchInstPrinter::printRegName(raw_ostream &O, unsigned RegNo) const {
+  O << getRegisterName(RegNo);
+}
+
+void LoongArchInstPrinter::printOperand(const MCInst *MI, unsigned OpNo,
+                                        const MCSubtargetInfo &STI,
+                                        raw_ostream &O) {
+  const MCOperand &MO = MI->getOperand(OpNo);
+
+  if (MO.isReg()) {
+    printRegName(O, MO.getReg());
+    return;
+  }
+
+  if (MO.isImm()) {
+    O << MO.getImm();
+    return;
+  }
+
+  assert(MO.isExpr() && "Unknown operand kind in printOperand");
+  MO.getExpr()->print(O, &MAI);
+}
+
+const char *LoongArchInstPrinter::getRegisterName(unsigned RegNo) {
+  // Default print reg alias name
+  return getRegisterName(RegNo, LoongArch::RegAliasName);
+}

llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchMCAsmInfo.h

+//===-- LoongArchMCAsmInfo.h - LoongArch Asm Info --------------*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains the declaration of the LoongArchMCAsmInfo class.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_TARGET_LOONGARCH_MCTARGETDESC_LOONGARCHMCASMINFO_H
+#define LLVM_LIB_TARGET_LOONGARCH_MCTARGETDESC_LOONGARCHMCASMINFO_H
+
+#include "llvm/MC/MCAsmInfoELF.h"
+
+namespace llvm {
+class Triple;
+
+class LoongArchMCAsmInfo : public MCAsmInfoELF {
+  void anchor() override;
+
+public:
+  explicit LoongArchMCAsmInfo(const Triple &TargetTriple);
+};
+
+} // namespace llvm
+
+#endif // LLVM_LIB_TARGET_LOONGARCH_MCTARGETDESC_LOONGARCHMCASMINFO_H

llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchMCAsmInfo.cpp

+//===-- LoongArchMCAsmInfo.cpp - LoongArch Asm properties ------*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains the declarations of the LoongArchMCAsmInfo properties.
+//
+//===----------------------------------------------------------------------===//
+
+#include "LoongArchMCAsmInfo.h"
+#include "llvm/ADT/Triple.h"
+#include "llvm/BinaryFormat/Dwarf.h"
+#include "llvm/MC/MCStreamer.h"
+
+using namespace llvm;
+
+void LoongArchMCAsmInfo::anchor() {}
+
+LoongArchMCAsmInfo::LoongArchMCAsmInfo(const Triple &TT) {
+  CodePointerSize = CalleeSaveStackSlotSize = TT.isArch64Bit() ? 8 : 4;
+  AlignmentIsInBytes = false;
+  Data8bitsDirective = "\t.byte\t";
+  Data16bitsDirective = "\t.half\t";
+  Data32bitsDirective = "\t.word\t";
+  Data64bitsDirective = "\t.dword\t";
+  ZeroDirective = "\t.space\t";
+  CommentString = "#";
+  SupportsDebugInformation = true;
+  ExceptionsType = ExceptionHandling::DwarfCFI;
+}

llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchMCCodeEmitter.cpp

+//=- LoongArchMCCodeEmitter.cpp - Convert LoongArch code to machine code --===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the LoongArchMCCodeEmitter class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "MCTargetDesc/LoongArchBaseInfo.h"
+#include "MCTargetDesc/LoongArchMCTargetDesc.h"
+#include "llvm/MC/MCCodeEmitter.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCInstBuilder.h"
+#include "llvm/MC/MCInstrInfo.h"
+#include "llvm/Support/EndianStream.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "mccodeemitter"
+
+namespace {
+class LoongArchMCCodeEmitter : public MCCodeEmitter {
+  LoongArchMCCodeEmitter(const LoongArchMCCodeEmitter &) = delete;
+  void operator=(const LoongArchMCCodeEmitter &) = delete;
+  MCContext &Ctx;
+  MCInstrInfo const &MCII;
+
+public:
+  LoongArchMCCodeEmitter(MCContext &ctx, MCInstrInfo const &MCII)
+      : Ctx(ctx), MCII(MCII) {}
+
+  ~LoongArchMCCodeEmitter() override {}
+
+  void encodeInstruction(const MCInst &MI, raw_ostream &OS,
+                         SmallVectorImpl<MCFixup> &Fixups,
+                         const MCSubtargetInfo &STI) const override;
+
+  /// TableGen'erated function for getting the binary encoding for an
+  /// instruction.
+  uint64_t getBinaryCodeForInstr(const MCInst &MI,
+                                 SmallVectorImpl<MCFixup> &Fixups,
+                                 const MCSubtargetInfo &STI) const;
+
+  /// Return binary encoding of operand. If the machine operand requires
+  /// relocation, record the relocation and return zero.
+  unsigned getMachineOpValue(const MCInst &MI, const MCOperand &MO,
+                             SmallVectorImpl<MCFixup> &Fixups,
+                             const MCSubtargetInfo &STI) const;
+};
+} // end anonymous namespace
+
+unsigned
+LoongArchMCCodeEmitter::getMachineOpValue(const MCInst &MI, const MCOperand &MO,
+                                          SmallVectorImpl<MCFixup> &Fixups,
+                                          const MCSubtargetInfo &STI) const {
+
+  if (MO.isReg())
+    return Ctx.getRegisterInfo()->getEncodingValue(MO.getReg());
+
+  if (MO.isImm())
+    return static_cast<unsigned>(MO.getImm());
+
+  llvm_unreachable("Unhandled expression!");
+  return 0;
+}
+
+void LoongArchMCCodeEmitter::encodeInstruction(
+    const MCInst &MI, raw_ostream &OS, SmallVectorImpl<MCFixup> &Fixups,
+    const MCSubtargetInfo &STI) const {
+  const MCInstrDesc &Desc = MCII.get(MI.getOpcode());
+  // Get byte count of instruction.
+  unsigned Size = Desc.getSize();
+
+  switch (Size) {
+  default:
+    llvm_unreachable("Unhandled encodeInstruction length!");
+  case 4: {
+    uint32_t Bits = getBinaryCodeForInstr(MI, Fixups, STI);
+    support::endian::write(OS, Bits, support::little);
+    break;
+  }
+  }
+}
+
+MCCodeEmitter *llvm::createLoongArchMCCodeEmitter(const MCInstrInfo &MCII,
+                                                  const MCRegisterInfo &MRI,
+                                                  MCContext &Ctx) {
+  return new LoongArchMCCodeEmitter(Ctx, MCII);
+}
+
+#include "LoongArchGenMCCodeEmitter.inc"

llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchMCTargetDesc.h

+//===- LoongArchMCTargetDesc.h - LoongArch Target Descriptions --*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file provides LoongArch specific target descriptions.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_TARGET_LOONGARCH_MCTARGETDESC_LOONGARCHMCTARGETDESC_H
+#define LLVM_LIB_TARGET_LOONGARCH_MCTARGETDESC_LOONGARCHMCTARGETDESC_H
+
+#include "llvm/MC/MCTargetOptions.h"
+#include "llvm/Support/DataTypes.h"
+#include <memory>
+
+namespace llvm {
+class MCAsmBackend;
+class MCCodeEmitter;
+class MCContext;
+class MCInstrInfo;
+class MCObjectTargetWriter;
+class MCRegisterInfo;
+class MCSubtargetInfo;
+class Target;
+
+MCCodeEmitter *createLoongArchMCCodeEmitter(const MCInstrInfo &MCII,
+                                            const MCRegisterInfo &MRI,
+                                            MCContext &Ctx);
+
+MCAsmBackend *createLoongArchAsmBackend(const Target &T,
+                                        const MCSubtargetInfo &STI,
+                                        const MCRegisterInfo &MRI,
+                                        const MCTargetOptions &Options);
+
+std::unique_ptr<MCObjectTargetWriter>
+createLoongArchELFObjectWriter(uint8_t OSABI, bool Is64Bit);
+
+} // namespace llvm
+
+// Defines symbolic names for LoongArch registers.
+#define GET_REGINFO_ENUM
+#include "LoongArchGenRegisterInfo.inc"
+
+// Defines symbolic names for LoongArch instructions.
+#define GET_INSTRINFO_ENUM
+#include "LoongArchGenInstrInfo.inc"
+
+#define GET_SUBTARGETINFO_ENUM
+#include "LoongArchGenSubtargetInfo.inc"
+
+#endif // LLVM_LIB_TARGET_LOONGARCH_MCTARGETDESC_LOONGARCHMCTARGETDESC_H

llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchMCTargetDesc.cpp

 //===-- LoongArchMCTargetDesc.cpp - LoongArch Target Descriptions ---------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 //
 // This file provides LoongArch specific target descriptions.
 //
 //===----------------------------------------------------------------------===//
 
+#include "LoongArchMCTargetDesc.h"
+#include "LoongArchBaseInfo.h"
+#include "LoongArchInstPrinter.h"
+#include "LoongArchMCAsmInfo.h"
+#include "TargetInfo/LoongArchTargetInfo.h"
+#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/MC/MCDwarf.h"
+#include "llvm/MC/MCInstrInfo.h"
+#include "llvm/MC/MCSubtargetInfo.h"
+#include "llvm/MC/TargetRegistry.h"
 #include "llvm/Support/Compiler.h"
 
-// FIXME: This is just a placeholder to make current commit buildable. Body of
-// this function will be filled in later commits.
-extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeLoongArchTargetMC() {}
+#define GET_INSTRINFO_MC_DESC
+#include "LoongArchGenInstrInfo.inc"
+
+#define GET_REGINFO_MC_DESC
+#include "LoongArchGenRegisterInfo.inc"
+
+#define GET_SUBTARGETINFO_MC_DESC
+#include "LoongArchGenSubtargetInfo.inc"
+
+using namespace llvm;
+
+static MCRegisterInfo *createLoongArchMCRegisterInfo(const Triple &TT) {
+  MCRegisterInfo *X = new MCRegisterInfo();
+  InitLoongArchMCRegisterInfo(X, LoongArch::R1);
+  return X;
+}
+
+static MCInstrInfo *createLoongArchMCInstrInfo() {
+  MCInstrInfo *X = new MCInstrInfo();
+  InitLoongArchMCInstrInfo(X);
+  return X;
+}
+
+static MCSubtargetInfo *
+createLoongArchMCSubtargetInfo(const Triple &TT, StringRef CPU, StringRef FS) {
+  if (CPU.empty())
+    CPU = TT.isArch64Bit() ? "la464" : "generic-la32";
+  return createLoongArchMCSubtargetInfoImpl(TT, CPU, /*TuneCPU*/ CPU, FS);
+}
+
+static MCAsmInfo *createLoongArchMCAsmInfo(const MCRegisterInfo &MRI,
+                                           const Triple &TT,
+                                           const MCTargetOptions &Options) {
+  MCAsmInfo *MAI = new LoongArchMCAsmInfo(TT);
+
+  MCRegister SP = MRI.getDwarfRegNum(LoongArch::R2, true);
+  MCCFIInstruction Inst = MCCFIInstruction::cfiDefCfa(nullptr, SP, 0);
+  MAI->addInitialFrameState(Inst);
+
+  return MAI;
+}
+
+static MCInstPrinter *createLoongArchMCInstPrinter(const Triple &T,
+                                                   unsigned SyntaxVariant,
+                                                   const MCAsmInfo &MAI,
+                                                   const MCInstrInfo &MII,
+                                                   const MCRegisterInfo &MRI) {
+  return new LoongArchInstPrinter(MAI, MII, MRI);
+}
+
+extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeLoongArchTargetMC() {
+  for (Target *T : {&getTheLoongArch32Target(), &getTheLoongArch64Target()}) {
+    // Register the MC register info.
+    TargetRegistry::RegisterMCRegInfo(*T, createLoongArchMCRegisterInfo);
+
+    // Register the MC instruction info.
+    TargetRegistry::RegisterMCInstrInfo(*T, createLoongArchMCInstrInfo);
+
+    // Register the MC subtarget info.
+    TargetRegistry::RegisterMCSubtargetInfo(*T, createLoongArchMCSubtargetInfo);
+
+    // Register the MC asm info.
+    TargetRegistry::RegisterMCAsmInfo(*T, createLoongArchMCAsmInfo);
+
+    // Register the MC Code Emitter
+    TargetRegistry::RegisterMCCodeEmitter(*T, createLoongArchMCCodeEmitter);
+
+    // Register the asm backend.
+    TargetRegistry::RegisterMCAsmBackend(*T, createLoongArchAsmBackend);
+
+    // Register the MCInstPrinter.
+    TargetRegistry::RegisterMCInstPrinter(*T, createLoongArchMCInstPrinter);
+  }
+}

llvm/lib/Target/LoongArch/TargetInfo/LoongArchTargetInfo.cpp

 
 Target &llvm::getTheLoongArch64Target() {
   static Target TheLoongArch64Target;
   return TheLoongArch64Target;
 }
 
 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeLoongArchTargetInfo() {
   RegisterTarget<Triple::loongarch32, /*HasJIT=*/false> X(
-      getTheLoongArch32Target(), "loongarch32", "LoongArch (32-bit)",
+      getTheLoongArch32Target(), "loongarch32", "32-bit LoongArch",
       "LoongArch");
   RegisterTarget<Triple::loongarch64, /*HasJIT=*/false> Y(
-      getTheLoongArch64Target(), "loongarch64", "LoongArch (64-bit)",
+      getTheLoongArch64Target(), "loongarch64", "64-bit LoongArch",
       "LoongArch");
 }

llvm/test/CodeGen/LoongArch/target_support.ll

 ; RUN: llc --version | FileCheck %s
-; CHECK:    loongarch32 - LoongArch (32-bit)
-; CHECK:    loongarch64 - LoongArch (64-bit)
+; CHECK:    loongarch32 - 32-bit LoongArch
+; CHECK:    loongarch64 - 64-bit LoongArch