1 //===-- AArch64MCTargetDesc.cpp - AArch64 Target Descriptions ---*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file provides AArch64 specific target descriptions.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "AArch64MCTargetDesc.h"
14 #include "AArch64ELFStreamer.h"
15 #include "AArch64MCAsmInfo.h"
16 #include "AArch64WinCOFFStreamer.h"
17 #include "MCTargetDesc/AArch64AddressingModes.h"
18 #include "MCTargetDesc/AArch64InstPrinter.h"
19 #include "TargetInfo/AArch64TargetInfo.h"
20 #include "llvm/DebugInfo/CodeView/CodeView.h"
21 #include "llvm/MC/MCAsmBackend.h"
22 #include "llvm/MC/MCCodeEmitter.h"
23 #include "llvm/MC/MCInstrAnalysis.h"
24 #include "llvm/MC/MCInstrInfo.h"
25 #include "llvm/MC/MCObjectWriter.h"
26 #include "llvm/MC/MCRegisterInfo.h"
27 #include "llvm/MC/MCStreamer.h"
28 #include "llvm/MC/MCSubtargetInfo.h"
29 #include "llvm/MC/TargetRegistry.h"
30 #include "llvm/Support/Endian.h"
31 #include "llvm/Support/ErrorHandling.h"
32 
33 using namespace llvm;
34 
35 #define GET_INSTRINFO_MC_DESC
36 #define GET_INSTRINFO_MC_HELPERS
37 #define ENABLE_INSTR_PREDICATE_VERIFIER
38 #include "AArch64GenInstrInfo.inc"
39 
40 #define GET_SUBTARGETINFO_MC_DESC
41 #include "AArch64GenSubtargetInfo.inc"
42 
43 #define GET_REGINFO_MC_DESC
44 #include "AArch64GenRegisterInfo.inc"
45 
46 static MCInstrInfo *createAArch64MCInstrInfo() {
47   MCInstrInfo *X = new MCInstrInfo();
48   InitAArch64MCInstrInfo(X);
49   return X;
50 }
51 
52 static MCSubtargetInfo *
53 createAArch64MCSubtargetInfo(const Triple &TT, StringRef CPU, StringRef FS) {
54   if (CPU.empty()) {
55     CPU = "generic";
56     if (FS.empty())
57       FS = "+v8a";
58 
59     if (TT.isArm64e())
60       CPU = "apple-a12";
61   }
62 
63   return createAArch64MCSubtargetInfoImpl(TT, CPU, /*TuneCPU*/ CPU, FS);
64 }
65 
66 void AArch64_MC::initLLVMToCVRegMapping(MCRegisterInfo *MRI) {
67   // Mapping from CodeView to MC register id.
68   static const struct {
69     codeview::RegisterId CVReg;
70     MCPhysReg Reg;
71   } RegMap[] = {
72       {codeview::RegisterId::ARM64_W0, AArch64::W0},
73       {codeview::RegisterId::ARM64_W1, AArch64::W1},
74       {codeview::RegisterId::ARM64_W2, AArch64::W2},
75       {codeview::RegisterId::ARM64_W3, AArch64::W3},
76       {codeview::RegisterId::ARM64_W4, AArch64::W4},
77       {codeview::RegisterId::ARM64_W5, AArch64::W5},
78       {codeview::RegisterId::ARM64_W6, AArch64::W6},
79       {codeview::RegisterId::ARM64_W7, AArch64::W7},
80       {codeview::RegisterId::ARM64_W8, AArch64::W8},
81       {codeview::RegisterId::ARM64_W9, AArch64::W9},
82       {codeview::RegisterId::ARM64_W10, AArch64::W10},
83       {codeview::RegisterId::ARM64_W11, AArch64::W11},
84       {codeview::RegisterId::ARM64_W12, AArch64::W12},
85       {codeview::RegisterId::ARM64_W13, AArch64::W13},
86       {codeview::RegisterId::ARM64_W14, AArch64::W14},
87       {codeview::RegisterId::ARM64_W15, AArch64::W15},
88       {codeview::RegisterId::ARM64_W16, AArch64::W16},
89       {codeview::RegisterId::ARM64_W17, AArch64::W17},
90       {codeview::RegisterId::ARM64_W18, AArch64::W18},
91       {codeview::RegisterId::ARM64_W19, AArch64::W19},
92       {codeview::RegisterId::ARM64_W20, AArch64::W20},
93       {codeview::RegisterId::ARM64_W21, AArch64::W21},
94       {codeview::RegisterId::ARM64_W22, AArch64::W22},
95       {codeview::RegisterId::ARM64_W23, AArch64::W23},
96       {codeview::RegisterId::ARM64_W24, AArch64::W24},
97       {codeview::RegisterId::ARM64_W25, AArch64::W25},
98       {codeview::RegisterId::ARM64_W26, AArch64::W26},
99       {codeview::RegisterId::ARM64_W27, AArch64::W27},
100       {codeview::RegisterId::ARM64_W28, AArch64::W28},
101       {codeview::RegisterId::ARM64_W29, AArch64::W29},
102       {codeview::RegisterId::ARM64_W30, AArch64::W30},
103       {codeview::RegisterId::ARM64_WZR, AArch64::WZR},
104       {codeview::RegisterId::ARM64_X0, AArch64::X0},
105       {codeview::RegisterId::ARM64_X1, AArch64::X1},
106       {codeview::RegisterId::ARM64_X2, AArch64::X2},
107       {codeview::RegisterId::ARM64_X3, AArch64::X3},
108       {codeview::RegisterId::ARM64_X4, AArch64::X4},
109       {codeview::RegisterId::ARM64_X5, AArch64::X5},
110       {codeview::RegisterId::ARM64_X6, AArch64::X6},
111       {codeview::RegisterId::ARM64_X7, AArch64::X7},
112       {codeview::RegisterId::ARM64_X8, AArch64::X8},
113       {codeview::RegisterId::ARM64_X9, AArch64::X9},
114       {codeview::RegisterId::ARM64_X10, AArch64::X10},
115       {codeview::RegisterId::ARM64_X11, AArch64::X11},
116       {codeview::RegisterId::ARM64_X12, AArch64::X12},
117       {codeview::RegisterId::ARM64_X13, AArch64::X13},
118       {codeview::RegisterId::ARM64_X14, AArch64::X14},
119       {codeview::RegisterId::ARM64_X15, AArch64::X15},
120       {codeview::RegisterId::ARM64_X16, AArch64::X16},
121       {codeview::RegisterId::ARM64_X17, AArch64::X17},
122       {codeview::RegisterId::ARM64_X18, AArch64::X18},
123       {codeview::RegisterId::ARM64_X19, AArch64::X19},
124       {codeview::RegisterId::ARM64_X20, AArch64::X20},
125       {codeview::RegisterId::ARM64_X21, AArch64::X21},
126       {codeview::RegisterId::ARM64_X22, AArch64::X22},
127       {codeview::RegisterId::ARM64_X23, AArch64::X23},
128       {codeview::RegisterId::ARM64_X24, AArch64::X24},
129       {codeview::RegisterId::ARM64_X25, AArch64::X25},
130       {codeview::RegisterId::ARM64_X26, AArch64::X26},
131       {codeview::RegisterId::ARM64_X27, AArch64::X27},
132       {codeview::RegisterId::ARM64_X28, AArch64::X28},
133       {codeview::RegisterId::ARM64_FP, AArch64::FP},
134       {codeview::RegisterId::ARM64_LR, AArch64::LR},
135       {codeview::RegisterId::ARM64_SP, AArch64::SP},
136       {codeview::RegisterId::ARM64_ZR, AArch64::XZR},
137       {codeview::RegisterId::ARM64_NZCV, AArch64::NZCV},
138       {codeview::RegisterId::ARM64_S0, AArch64::S0},
139       {codeview::RegisterId::ARM64_S1, AArch64::S1},
140       {codeview::RegisterId::ARM64_S2, AArch64::S2},
141       {codeview::RegisterId::ARM64_S3, AArch64::S3},
142       {codeview::RegisterId::ARM64_S4, AArch64::S4},
143       {codeview::RegisterId::ARM64_S5, AArch64::S5},
144       {codeview::RegisterId::ARM64_S6, AArch64::S6},
145       {codeview::RegisterId::ARM64_S7, AArch64::S7},
146       {codeview::RegisterId::ARM64_S8, AArch64::S8},
147       {codeview::RegisterId::ARM64_S9, AArch64::S9},
148       {codeview::RegisterId::ARM64_S10, AArch64::S10},
149       {codeview::RegisterId::ARM64_S11, AArch64::S11},
150       {codeview::RegisterId::ARM64_S12, AArch64::S12},
151       {codeview::RegisterId::ARM64_S13, AArch64::S13},
152       {codeview::RegisterId::ARM64_S14, AArch64::S14},
153       {codeview::RegisterId::ARM64_S15, AArch64::S15},
154       {codeview::RegisterId::ARM64_S16, AArch64::S16},
155       {codeview::RegisterId::ARM64_S17, AArch64::S17},
156       {codeview::RegisterId::ARM64_S18, AArch64::S18},
157       {codeview::RegisterId::ARM64_S19, AArch64::S19},
158       {codeview::RegisterId::ARM64_S20, AArch64::S20},
159       {codeview::RegisterId::ARM64_S21, AArch64::S21},
160       {codeview::RegisterId::ARM64_S22, AArch64::S22},
161       {codeview::RegisterId::ARM64_S23, AArch64::S23},
162       {codeview::RegisterId::ARM64_S24, AArch64::S24},
163       {codeview::RegisterId::ARM64_S25, AArch64::S25},
164       {codeview::RegisterId::ARM64_S26, AArch64::S26},
165       {codeview::RegisterId::ARM64_S27, AArch64::S27},
166       {codeview::RegisterId::ARM64_S28, AArch64::S28},
167       {codeview::RegisterId::ARM64_S29, AArch64::S29},
168       {codeview::RegisterId::ARM64_S30, AArch64::S30},
169       {codeview::RegisterId::ARM64_S31, AArch64::S31},
170       {codeview::RegisterId::ARM64_D0, AArch64::D0},
171       {codeview::RegisterId::ARM64_D1, AArch64::D1},
172       {codeview::RegisterId::ARM64_D2, AArch64::D2},
173       {codeview::RegisterId::ARM64_D3, AArch64::D3},
174       {codeview::RegisterId::ARM64_D4, AArch64::D4},
175       {codeview::RegisterId::ARM64_D5, AArch64::D5},
176       {codeview::RegisterId::ARM64_D6, AArch64::D6},
177       {codeview::RegisterId::ARM64_D7, AArch64::D7},
178       {codeview::RegisterId::ARM64_D8, AArch64::D8},
179       {codeview::RegisterId::ARM64_D9, AArch64::D9},
180       {codeview::RegisterId::ARM64_D10, AArch64::D10},
181       {codeview::RegisterId::ARM64_D11, AArch64::D11},
182       {codeview::RegisterId::ARM64_D12, AArch64::D12},
183       {codeview::RegisterId::ARM64_D13, AArch64::D13},
184       {codeview::RegisterId::ARM64_D14, AArch64::D14},
185       {codeview::RegisterId::ARM64_D15, AArch64::D15},
186       {codeview::RegisterId::ARM64_D16, AArch64::D16},
187       {codeview::RegisterId::ARM64_D17, AArch64::D17},
188       {codeview::RegisterId::ARM64_D18, AArch64::D18},
189       {codeview::RegisterId::ARM64_D19, AArch64::D19},
190       {codeview::RegisterId::ARM64_D20, AArch64::D20},
191       {codeview::RegisterId::ARM64_D21, AArch64::D21},
192       {codeview::RegisterId::ARM64_D22, AArch64::D22},
193       {codeview::RegisterId::ARM64_D23, AArch64::D23},
194       {codeview::RegisterId::ARM64_D24, AArch64::D24},
195       {codeview::RegisterId::ARM64_D25, AArch64::D25},
196       {codeview::RegisterId::ARM64_D26, AArch64::D26},
197       {codeview::RegisterId::ARM64_D27, AArch64::D27},
198       {codeview::RegisterId::ARM64_D28, AArch64::D28},
199       {codeview::RegisterId::ARM64_D29, AArch64::D29},
200       {codeview::RegisterId::ARM64_D30, AArch64::D30},
201       {codeview::RegisterId::ARM64_D31, AArch64::D31},
202       {codeview::RegisterId::ARM64_Q0, AArch64::Q0},
203       {codeview::RegisterId::ARM64_Q1, AArch64::Q1},
204       {codeview::RegisterId::ARM64_Q2, AArch64::Q2},
205       {codeview::RegisterId::ARM64_Q3, AArch64::Q3},
206       {codeview::RegisterId::ARM64_Q4, AArch64::Q4},
207       {codeview::RegisterId::ARM64_Q5, AArch64::Q5},
208       {codeview::RegisterId::ARM64_Q6, AArch64::Q6},
209       {codeview::RegisterId::ARM64_Q7, AArch64::Q7},
210       {codeview::RegisterId::ARM64_Q8, AArch64::Q8},
211       {codeview::RegisterId::ARM64_Q9, AArch64::Q9},
212       {codeview::RegisterId::ARM64_Q10, AArch64::Q10},
213       {codeview::RegisterId::ARM64_Q11, AArch64::Q11},
214       {codeview::RegisterId::ARM64_Q12, AArch64::Q12},
215       {codeview::RegisterId::ARM64_Q13, AArch64::Q13},
216       {codeview::RegisterId::ARM64_Q14, AArch64::Q14},
217       {codeview::RegisterId::ARM64_Q15, AArch64::Q15},
218       {codeview::RegisterId::ARM64_Q16, AArch64::Q16},
219       {codeview::RegisterId::ARM64_Q17, AArch64::Q17},
220       {codeview::RegisterId::ARM64_Q18, AArch64::Q18},
221       {codeview::RegisterId::ARM64_Q19, AArch64::Q19},
222       {codeview::RegisterId::ARM64_Q20, AArch64::Q20},
223       {codeview::RegisterId::ARM64_Q21, AArch64::Q21},
224       {codeview::RegisterId::ARM64_Q22, AArch64::Q22},
225       {codeview::RegisterId::ARM64_Q23, AArch64::Q23},
226       {codeview::RegisterId::ARM64_Q24, AArch64::Q24},
227       {codeview::RegisterId::ARM64_Q25, AArch64::Q25},
228       {codeview::RegisterId::ARM64_Q26, AArch64::Q26},
229       {codeview::RegisterId::ARM64_Q27, AArch64::Q27},
230       {codeview::RegisterId::ARM64_Q28, AArch64::Q28},
231       {codeview::RegisterId::ARM64_Q29, AArch64::Q29},
232       {codeview::RegisterId::ARM64_Q30, AArch64::Q30},
233       {codeview::RegisterId::ARM64_Q31, AArch64::Q31},
234 
235   };
236   for (const auto &I : RegMap)
237     MRI->mapLLVMRegToCVReg(I.Reg, static_cast<int>(I.CVReg));
238 }
239 
240 bool AArch64_MC::isQForm(const MCInst &MI, const MCInstrInfo *MCII) {
241   const auto &FPR128 = AArch64MCRegisterClasses[AArch64::FPR128RegClassID];
242   return llvm::any_of(MI, [&](const MCOperand &Op) {
243     return Op.isReg() && FPR128.contains(Op.getReg());
244   });
245 }
246 
247 bool AArch64_MC::isFpOrNEON(const MCInst &MI, const MCInstrInfo *MCII) {
248   const auto &FPR128 = AArch64MCRegisterClasses[AArch64::FPR128RegClassID];
249   const auto &FPR64 = AArch64MCRegisterClasses[AArch64::FPR64RegClassID];
250   const auto &FPR32 = AArch64MCRegisterClasses[AArch64::FPR32RegClassID];
251   const auto &FPR16 = AArch64MCRegisterClasses[AArch64::FPR16RegClassID];
252   const auto &FPR8 = AArch64MCRegisterClasses[AArch64::FPR8RegClassID];
253 
254   auto IsFPR = [&](const MCOperand &Op) {
255     if (!Op.isReg())
256       return false;
257     auto Reg = Op.getReg();
258     return FPR128.contains(Reg) || FPR64.contains(Reg) || FPR32.contains(Reg) ||
259            FPR16.contains(Reg) || FPR8.contains(Reg);
260   };
261 
262   return llvm::any_of(MI, IsFPR);
263 }
264 
265 static MCRegisterInfo *createAArch64MCRegisterInfo(const Triple &Triple) {
266   MCRegisterInfo *X = new MCRegisterInfo();
267   InitAArch64MCRegisterInfo(X, AArch64::LR);
268   AArch64_MC::initLLVMToCVRegMapping(X);
269   return X;
270 }
271 
272 static MCAsmInfo *createAArch64MCAsmInfo(const MCRegisterInfo &MRI,
273                                          const Triple &TheTriple,
274                                          const MCTargetOptions &Options) {
275   MCAsmInfo *MAI;
276   if (TheTriple.isOSBinFormatMachO())
277     MAI = new AArch64MCAsmInfoDarwin(TheTriple.getArch() == Triple::aarch64_32);
278   else if (TheTriple.isWindowsMSVCEnvironment())
279     MAI = new AArch64MCAsmInfoMicrosoftCOFF();
280   else if (TheTriple.isOSBinFormatCOFF())
281     MAI = new AArch64MCAsmInfoGNUCOFF();
282   else {
283     assert(TheTriple.isOSBinFormatELF() && "Invalid target");
284     MAI = new AArch64MCAsmInfoELF(TheTriple);
285   }
286 
287   // Initial state of the frame pointer is SP.
288   unsigned Reg = MRI.getDwarfRegNum(AArch64::SP, true);
289   MCCFIInstruction Inst = MCCFIInstruction::cfiDefCfa(nullptr, Reg, 0);
290   MAI->addInitialFrameState(Inst);
291 
292   return MAI;
293 }
294 
295 static MCInstPrinter *createAArch64MCInstPrinter(const Triple &T,
296                                                  unsigned SyntaxVariant,
297                                                  const MCAsmInfo &MAI,
298                                                  const MCInstrInfo &MII,
299                                                  const MCRegisterInfo &MRI) {
300   if (SyntaxVariant == 0)
301     return new AArch64InstPrinter(MAI, MII, MRI);
302   if (SyntaxVariant == 1)
303     return new AArch64AppleInstPrinter(MAI, MII, MRI);
304 
305   return nullptr;
306 }
307 
308 static MCStreamer *createELFStreamer(const Triple &T, MCContext &Ctx,
309                                      std::unique_ptr<MCAsmBackend> &&TAB,
310                                      std::unique_ptr<MCObjectWriter> &&OW,
311                                      std::unique_ptr<MCCodeEmitter> &&Emitter,
312                                      bool RelaxAll) {
313   return createAArch64ELFStreamer(Ctx, std::move(TAB), std::move(OW),
314                                   std::move(Emitter), RelaxAll);
315 }
316 
317 static MCStreamer *createMachOStreamer(MCContext &Ctx,
318                                        std::unique_ptr<MCAsmBackend> &&TAB,
319                                        std::unique_ptr<MCObjectWriter> &&OW,
320                                        std::unique_ptr<MCCodeEmitter> &&Emitter,
321                                        bool RelaxAll,
322                                        bool DWARFMustBeAtTheEnd) {
323   return createMachOStreamer(Ctx, std::move(TAB), std::move(OW),
324                              std::move(Emitter), RelaxAll, DWARFMustBeAtTheEnd,
325                              /*LabelSections*/ true);
326 }
327 
328 static MCStreamer *
329 createWinCOFFStreamer(MCContext &Ctx, std::unique_ptr<MCAsmBackend> &&TAB,
330                       std::unique_ptr<MCObjectWriter> &&OW,
331                       std::unique_ptr<MCCodeEmitter> &&Emitter, bool RelaxAll,
332                       bool IncrementalLinkerCompatible) {
333   return createAArch64WinCOFFStreamer(Ctx, std::move(TAB), std::move(OW),
334                                       std::move(Emitter), RelaxAll,
335                                       IncrementalLinkerCompatible);
336 }
337 
338 namespace {
339 
340 class AArch64MCInstrAnalysis : public MCInstrAnalysis {
341 public:
342   AArch64MCInstrAnalysis(const MCInstrInfo *Info) : MCInstrAnalysis(Info) {}
343 
344   bool evaluateBranch(const MCInst &Inst, uint64_t Addr, uint64_t Size,
345                       uint64_t &Target) const override {
346     // Search for a PC-relative argument.
347     // This will handle instructions like bcc (where the first argument is the
348     // condition code) and cbz (where it is a register).
349     const auto &Desc = Info->get(Inst.getOpcode());
350     for (unsigned i = 0, e = Inst.getNumOperands(); i != e; i++) {
351       if (Desc.OpInfo[i].OperandType == MCOI::OPERAND_PCREL) {
352         int64_t Imm = Inst.getOperand(i).getImm() * 4;
353         Target = Addr + Imm;
354         return true;
355       }
356     }
357     return false;
358   }
359 
360   std::vector<std::pair<uint64_t, uint64_t>>
361   findPltEntries(uint64_t PltSectionVA, ArrayRef<uint8_t> PltContents,
362                  uint64_t GotPltSectionVA,
363                  const Triple &TargetTriple) const override {
364     // Do a lightweight parsing of PLT entries.
365     std::vector<std::pair<uint64_t, uint64_t>> Result;
366     for (uint64_t Byte = 0, End = PltContents.size(); Byte + 7 < End;
367          Byte += 4) {
368       uint32_t Insn = support::endian::read32le(PltContents.data() + Byte);
369       uint64_t Off = 0;
370       // Check for optional bti c that prefixes adrp in BTI enabled entries
371       if (Insn == 0xd503245f) {
372          Off = 4;
373          Insn = support::endian::read32le(PltContents.data() + Byte + Off);
374       }
375       // Check for adrp.
376       if ((Insn & 0x9f000000) != 0x90000000)
377         continue;
378       Off += 4;
379       uint64_t Imm = (((PltSectionVA + Byte) >> 12) << 12) +
380             (((Insn >> 29) & 3) << 12) + (((Insn >> 5) & 0x3ffff) << 14);
381       uint32_t Insn2 =
382           support::endian::read32le(PltContents.data() + Byte + Off);
383       // Check for: ldr Xt, [Xn, #pimm].
384       if (Insn2 >> 22 == 0x3e5) {
385         Imm += ((Insn2 >> 10) & 0xfff) << 3;
386         Result.push_back(std::make_pair(PltSectionVA + Byte, Imm));
387         Byte += 4;
388       }
389     }
390     return Result;
391   }
392 };
393 
394 } // end anonymous namespace
395 
396 static MCInstrAnalysis *createAArch64InstrAnalysis(const MCInstrInfo *Info) {
397   return new AArch64MCInstrAnalysis(Info);
398 }
399 
400 // Force static initialization.
401 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeAArch64TargetMC() {
402   for (Target *T : {&getTheAArch64leTarget(), &getTheAArch64beTarget(),
403                     &getTheAArch64_32Target(), &getTheARM64Target(),
404                     &getTheARM64_32Target()}) {
405     // Register the MC asm info.
406     RegisterMCAsmInfoFn X(*T, createAArch64MCAsmInfo);
407 
408     // Register the MC instruction info.
409     TargetRegistry::RegisterMCInstrInfo(*T, createAArch64MCInstrInfo);
410 
411     // Register the MC register info.
412     TargetRegistry::RegisterMCRegInfo(*T, createAArch64MCRegisterInfo);
413 
414     // Register the MC subtarget info.
415     TargetRegistry::RegisterMCSubtargetInfo(*T, createAArch64MCSubtargetInfo);
416 
417     // Register the MC instruction analyzer.
418     TargetRegistry::RegisterMCInstrAnalysis(*T, createAArch64InstrAnalysis);
419 
420     // Register the MC Code Emitter
421     TargetRegistry::RegisterMCCodeEmitter(*T, createAArch64MCCodeEmitter);
422 
423     // Register the obj streamers.
424     TargetRegistry::RegisterELFStreamer(*T, createELFStreamer);
425     TargetRegistry::RegisterMachOStreamer(*T, createMachOStreamer);
426     TargetRegistry::RegisterCOFFStreamer(*T, createWinCOFFStreamer);
427 
428     // Register the obj target streamer.
429     TargetRegistry::RegisterObjectTargetStreamer(
430         *T, createAArch64ObjectTargetStreamer);
431 
432     // Register the asm streamer.
433     TargetRegistry::RegisterAsmTargetStreamer(*T,
434                                               createAArch64AsmTargetStreamer);
435     // Register the MCInstPrinter.
436     TargetRegistry::RegisterMCInstPrinter(*T, createAArch64MCInstPrinter);
437   }
438 
439   // Register the asm backend.
440   for (Target *T : {&getTheAArch64leTarget(), &getTheAArch64_32Target(),
441                     &getTheARM64Target(), &getTheARM64_32Target()})
442     TargetRegistry::RegisterMCAsmBackend(*T, createAArch64leAsmBackend);
443   TargetRegistry::RegisterMCAsmBackend(getTheAArch64beTarget(),
444                                        createAArch64beAsmBackend);
445 }
446