xref: /freebsd-src/contrib/llvm-project/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp (revision a7dea1671b87c07d2d266f836bfa8b58efc7c134)
1 //===- AArch64AsmPrinter.cpp - AArch64 LLVM assembly writer ---------------===//
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 contains a printer that converts from our internal representation
10 // of machine-dependent LLVM code to the AArch64 assembly language.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "AArch64.h"
15 #include "AArch64MCInstLower.h"
16 #include "AArch64MachineFunctionInfo.h"
17 #include "AArch64RegisterInfo.h"
18 #include "AArch64Subtarget.h"
19 #include "AArch64TargetObjectFile.h"
20 #include "MCTargetDesc/AArch64AddressingModes.h"
21 #include "MCTargetDesc/AArch64InstPrinter.h"
22 #include "MCTargetDesc/AArch64MCExpr.h"
23 #include "MCTargetDesc/AArch64MCTargetDesc.h"
24 #include "MCTargetDesc/AArch64TargetStreamer.h"
25 #include "TargetInfo/AArch64TargetInfo.h"
26 #include "Utils/AArch64BaseInfo.h"
27 #include "llvm/ADT/SmallString.h"
28 #include "llvm/ADT/SmallVector.h"
29 #include "llvm/ADT/StringRef.h"
30 #include "llvm/ADT/Triple.h"
31 #include "llvm/ADT/Twine.h"
32 #include "llvm/BinaryFormat/COFF.h"
33 #include "llvm/BinaryFormat/ELF.h"
34 #include "llvm/CodeGen/AsmPrinter.h"
35 #include "llvm/CodeGen/MachineBasicBlock.h"
36 #include "llvm/CodeGen/MachineFunction.h"
37 #include "llvm/CodeGen/MachineInstr.h"
38 #include "llvm/CodeGen/MachineJumpTableInfo.h"
39 #include "llvm/CodeGen/MachineModuleInfoImpls.h"
40 #include "llvm/CodeGen/MachineOperand.h"
41 #include "llvm/CodeGen/StackMaps.h"
42 #include "llvm/CodeGen/TargetRegisterInfo.h"
43 #include "llvm/IR/DataLayout.h"
44 #include "llvm/IR/DebugInfoMetadata.h"
45 #include "llvm/MC/MCAsmInfo.h"
46 #include "llvm/MC/MCContext.h"
47 #include "llvm/MC/MCInst.h"
48 #include "llvm/MC/MCInstBuilder.h"
49 #include "llvm/MC/MCSectionELF.h"
50 #include "llvm/MC/MCStreamer.h"
51 #include "llvm/MC/MCSymbol.h"
52 #include "llvm/Support/Casting.h"
53 #include "llvm/Support/ErrorHandling.h"
54 #include "llvm/Support/TargetRegistry.h"
55 #include "llvm/Support/raw_ostream.h"
56 #include "llvm/Target/TargetMachine.h"
57 #include <algorithm>
58 #include <cassert>
59 #include <cstdint>
60 #include <map>
61 #include <memory>
62 
63 using namespace llvm;
64 
65 #define DEBUG_TYPE "asm-printer"
66 
67 namespace {
68 
69 class AArch64AsmPrinter : public AsmPrinter {
70   AArch64MCInstLower MCInstLowering;
71   StackMaps SM;
72   const AArch64Subtarget *STI;
73 
74 public:
75   AArch64AsmPrinter(TargetMachine &TM, std::unique_ptr<MCStreamer> Streamer)
76       : AsmPrinter(TM, std::move(Streamer)), MCInstLowering(OutContext, *this),
77         SM(*this) {}
78 
79   StringRef getPassName() const override { return "AArch64 Assembly Printer"; }
80 
81   /// Wrapper for MCInstLowering.lowerOperand() for the
82   /// tblgen'erated pseudo lowering.
83   bool lowerOperand(const MachineOperand &MO, MCOperand &MCOp) const {
84     return MCInstLowering.lowerOperand(MO, MCOp);
85   }
86 
87   void EmitJumpTableInfo() override;
88   void emitJumpTableEntry(const MachineJumpTableInfo *MJTI,
89                           const MachineBasicBlock *MBB, unsigned JTI);
90 
91   void LowerJumpTableDestSmall(MCStreamer &OutStreamer, const MachineInstr &MI);
92 
93   void LowerSTACKMAP(MCStreamer &OutStreamer, StackMaps &SM,
94                      const MachineInstr &MI);
95   void LowerPATCHPOINT(MCStreamer &OutStreamer, StackMaps &SM,
96                        const MachineInstr &MI);
97 
98   void LowerPATCHABLE_FUNCTION_ENTER(const MachineInstr &MI);
99   void LowerPATCHABLE_FUNCTION_EXIT(const MachineInstr &MI);
100   void LowerPATCHABLE_TAIL_CALL(const MachineInstr &MI);
101 
102   typedef std::tuple<unsigned, bool, uint32_t> HwasanMemaccessTuple;
103   std::map<HwasanMemaccessTuple, MCSymbol *> HwasanMemaccessSymbols;
104   void LowerHWASAN_CHECK_MEMACCESS(const MachineInstr &MI);
105   void EmitHwasanMemaccessSymbols(Module &M);
106 
107   void EmitSled(const MachineInstr &MI, SledKind Kind);
108 
109   /// tblgen'erated driver function for lowering simple MI->MC
110   /// pseudo instructions.
111   bool emitPseudoExpansionLowering(MCStreamer &OutStreamer,
112                                    const MachineInstr *MI);
113 
114   void EmitInstruction(const MachineInstr *MI) override;
115 
116   void getAnalysisUsage(AnalysisUsage &AU) const override {
117     AsmPrinter::getAnalysisUsage(AU);
118     AU.setPreservesAll();
119   }
120 
121   bool runOnMachineFunction(MachineFunction &MF) override {
122     AArch64FI = MF.getInfo<AArch64FunctionInfo>();
123     STI = static_cast<const AArch64Subtarget*>(&MF.getSubtarget());
124 
125     SetupMachineFunction(MF);
126 
127     if (STI->isTargetCOFF()) {
128       bool Internal = MF.getFunction().hasInternalLinkage();
129       COFF::SymbolStorageClass Scl = Internal ? COFF::IMAGE_SYM_CLASS_STATIC
130                                               : COFF::IMAGE_SYM_CLASS_EXTERNAL;
131       int Type =
132         COFF::IMAGE_SYM_DTYPE_FUNCTION << COFF::SCT_COMPLEX_TYPE_SHIFT;
133 
134       OutStreamer->BeginCOFFSymbolDef(CurrentFnSym);
135       OutStreamer->EmitCOFFSymbolStorageClass(Scl);
136       OutStreamer->EmitCOFFSymbolType(Type);
137       OutStreamer->EndCOFFSymbolDef();
138     }
139 
140     // Emit the rest of the function body.
141     EmitFunctionBody();
142 
143     // Emit the XRay table for this function.
144     emitXRayTable();
145 
146     // We didn't modify anything.
147     return false;
148   }
149 
150 private:
151   void printOperand(const MachineInstr *MI, unsigned OpNum, raw_ostream &O);
152   bool printAsmMRegister(const MachineOperand &MO, char Mode, raw_ostream &O);
153   bool printAsmRegInClass(const MachineOperand &MO,
154                           const TargetRegisterClass *RC, unsigned AltName,
155                           raw_ostream &O);
156 
157   bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNum,
158                        const char *ExtraCode, raw_ostream &O) override;
159   bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNum,
160                              const char *ExtraCode, raw_ostream &O) override;
161 
162   void PrintDebugValueComment(const MachineInstr *MI, raw_ostream &OS);
163 
164   void EmitFunctionBodyEnd() override;
165 
166   MCSymbol *GetCPISymbol(unsigned CPID) const override;
167   void EmitEndOfAsmFile(Module &M) override;
168 
169   AArch64FunctionInfo *AArch64FI = nullptr;
170 
171   /// Emit the LOHs contained in AArch64FI.
172   void EmitLOHs();
173 
174   /// Emit instruction to set float register to zero.
175   void EmitFMov0(const MachineInstr &MI);
176 
177   using MInstToMCSymbol = std::map<const MachineInstr *, MCSymbol *>;
178 
179   MInstToMCSymbol LOHInstToLabel;
180 };
181 
182 } // end anonymous namespace
183 
184 void AArch64AsmPrinter::LowerPATCHABLE_FUNCTION_ENTER(const MachineInstr &MI)
185 {
186   EmitSled(MI, SledKind::FUNCTION_ENTER);
187 }
188 
189 void AArch64AsmPrinter::LowerPATCHABLE_FUNCTION_EXIT(const MachineInstr &MI)
190 {
191   EmitSled(MI, SledKind::FUNCTION_EXIT);
192 }
193 
194 void AArch64AsmPrinter::LowerPATCHABLE_TAIL_CALL(const MachineInstr &MI)
195 {
196   EmitSled(MI, SledKind::TAIL_CALL);
197 }
198 
199 void AArch64AsmPrinter::EmitSled(const MachineInstr &MI, SledKind Kind)
200 {
201   static const int8_t NoopsInSledCount = 7;
202   // We want to emit the following pattern:
203   //
204   // .Lxray_sled_N:
205   //   ALIGN
206   //   B #32
207   //   ; 7 NOP instructions (28 bytes)
208   // .tmpN
209   //
210   // We need the 28 bytes (7 instructions) because at runtime, we'd be patching
211   // over the full 32 bytes (8 instructions) with the following pattern:
212   //
213   //   STP X0, X30, [SP, #-16]! ; push X0 and the link register to the stack
214   //   LDR W0, #12 ; W0 := function ID
215   //   LDR X16,#12 ; X16 := addr of __xray_FunctionEntry or __xray_FunctionExit
216   //   BLR X16 ; call the tracing trampoline
217   //   ;DATA: 32 bits of function ID
218   //   ;DATA: lower 32 bits of the address of the trampoline
219   //   ;DATA: higher 32 bits of the address of the trampoline
220   //   LDP X0, X30, [SP], #16 ; pop X0 and the link register from the stack
221   //
222   OutStreamer->EmitCodeAlignment(4);
223   auto CurSled = OutContext.createTempSymbol("xray_sled_", true);
224   OutStreamer->EmitLabel(CurSled);
225   auto Target = OutContext.createTempSymbol();
226 
227   // Emit "B #32" instruction, which jumps over the next 28 bytes.
228   // The operand has to be the number of 4-byte instructions to jump over,
229   // including the current instruction.
230   EmitToStreamer(*OutStreamer, MCInstBuilder(AArch64::B).addImm(8));
231 
232   for (int8_t I = 0; I < NoopsInSledCount; I++)
233     EmitToStreamer(*OutStreamer, MCInstBuilder(AArch64::HINT).addImm(0));
234 
235   OutStreamer->EmitLabel(Target);
236   recordSled(CurSled, MI, Kind);
237 }
238 
239 void AArch64AsmPrinter::LowerHWASAN_CHECK_MEMACCESS(const MachineInstr &MI) {
240   Register Reg = MI.getOperand(0).getReg();
241   bool IsShort =
242       MI.getOpcode() == AArch64::HWASAN_CHECK_MEMACCESS_SHORTGRANULES;
243   uint32_t AccessInfo = MI.getOperand(1).getImm();
244   MCSymbol *&Sym =
245       HwasanMemaccessSymbols[HwasanMemaccessTuple(Reg, IsShort, AccessInfo)];
246   if (!Sym) {
247     // FIXME: Make this work on non-ELF.
248     if (!TM.getTargetTriple().isOSBinFormatELF())
249       report_fatal_error("llvm.hwasan.check.memaccess only supported on ELF");
250 
251     std::string SymName = "__hwasan_check_x" + utostr(Reg - AArch64::X0) + "_" +
252                           utostr(AccessInfo);
253     if (IsShort)
254       SymName += "_short";
255     Sym = OutContext.getOrCreateSymbol(SymName);
256   }
257 
258   EmitToStreamer(*OutStreamer,
259                  MCInstBuilder(AArch64::BL)
260                      .addExpr(MCSymbolRefExpr::create(Sym, OutContext)));
261 }
262 
263 void AArch64AsmPrinter::EmitHwasanMemaccessSymbols(Module &M) {
264   if (HwasanMemaccessSymbols.empty())
265     return;
266 
267   const Triple &TT = TM.getTargetTriple();
268   assert(TT.isOSBinFormatELF());
269   std::unique_ptr<MCSubtargetInfo> STI(
270       TM.getTarget().createMCSubtargetInfo(TT.str(), "", ""));
271 
272   MCSymbol *HwasanTagMismatchV1Sym =
273       OutContext.getOrCreateSymbol("__hwasan_tag_mismatch");
274   MCSymbol *HwasanTagMismatchV2Sym =
275       OutContext.getOrCreateSymbol("__hwasan_tag_mismatch_v2");
276 
277   const MCSymbolRefExpr *HwasanTagMismatchV1Ref =
278       MCSymbolRefExpr::create(HwasanTagMismatchV1Sym, OutContext);
279   const MCSymbolRefExpr *HwasanTagMismatchV2Ref =
280       MCSymbolRefExpr::create(HwasanTagMismatchV2Sym, OutContext);
281 
282   for (auto &P : HwasanMemaccessSymbols) {
283     unsigned Reg = std::get<0>(P.first);
284     bool IsShort = std::get<1>(P.first);
285     uint32_t AccessInfo = std::get<2>(P.first);
286     const MCSymbolRefExpr *HwasanTagMismatchRef =
287         IsShort ? HwasanTagMismatchV2Ref : HwasanTagMismatchV1Ref;
288     MCSymbol *Sym = P.second;
289 
290     OutStreamer->SwitchSection(OutContext.getELFSection(
291         ".text.hot", ELF::SHT_PROGBITS,
292         ELF::SHF_EXECINSTR | ELF::SHF_ALLOC | ELF::SHF_GROUP, 0,
293         Sym->getName()));
294 
295     OutStreamer->EmitSymbolAttribute(Sym, MCSA_ELF_TypeFunction);
296     OutStreamer->EmitSymbolAttribute(Sym, MCSA_Weak);
297     OutStreamer->EmitSymbolAttribute(Sym, MCSA_Hidden);
298     OutStreamer->EmitLabel(Sym);
299 
300     OutStreamer->EmitInstruction(MCInstBuilder(AArch64::UBFMXri)
301                                      .addReg(AArch64::X16)
302                                      .addReg(Reg)
303                                      .addImm(4)
304                                      .addImm(55),
305                                  *STI);
306     OutStreamer->EmitInstruction(MCInstBuilder(AArch64::LDRBBroX)
307                                      .addReg(AArch64::W16)
308                                      .addReg(AArch64::X9)
309                                      .addReg(AArch64::X16)
310                                      .addImm(0)
311                                      .addImm(0),
312                                  *STI);
313     OutStreamer->EmitInstruction(
314         MCInstBuilder(AArch64::SUBSXrs)
315             .addReg(AArch64::XZR)
316             .addReg(AArch64::X16)
317             .addReg(Reg)
318             .addImm(AArch64_AM::getShifterImm(AArch64_AM::LSR, 56)),
319         *STI);
320     MCSymbol *HandleMismatchOrPartialSym = OutContext.createTempSymbol();
321     OutStreamer->EmitInstruction(
322         MCInstBuilder(AArch64::Bcc)
323             .addImm(AArch64CC::NE)
324             .addExpr(MCSymbolRefExpr::create(HandleMismatchOrPartialSym,
325                                              OutContext)),
326         *STI);
327     MCSymbol *ReturnSym = OutContext.createTempSymbol();
328     OutStreamer->EmitLabel(ReturnSym);
329     OutStreamer->EmitInstruction(
330         MCInstBuilder(AArch64::RET).addReg(AArch64::LR), *STI);
331     OutStreamer->EmitLabel(HandleMismatchOrPartialSym);
332 
333     if (IsShort) {
334       OutStreamer->EmitInstruction(MCInstBuilder(AArch64::SUBSWri)
335                                        .addReg(AArch64::WZR)
336                                        .addReg(AArch64::W16)
337                                        .addImm(15)
338                                        .addImm(0),
339                                    *STI);
340       MCSymbol *HandleMismatchSym = OutContext.createTempSymbol();
341       OutStreamer->EmitInstruction(
342           MCInstBuilder(AArch64::Bcc)
343               .addImm(AArch64CC::HI)
344               .addExpr(MCSymbolRefExpr::create(HandleMismatchSym, OutContext)),
345           *STI);
346 
347       OutStreamer->EmitInstruction(
348           MCInstBuilder(AArch64::ANDXri)
349               .addReg(AArch64::X17)
350               .addReg(Reg)
351               .addImm(AArch64_AM::encodeLogicalImmediate(0xf, 64)),
352           *STI);
353       unsigned Size = 1 << (AccessInfo & 0xf);
354       if (Size != 1)
355         OutStreamer->EmitInstruction(MCInstBuilder(AArch64::ADDXri)
356                                          .addReg(AArch64::X17)
357                                          .addReg(AArch64::X17)
358                                          .addImm(Size - 1)
359                                          .addImm(0),
360                                      *STI);
361       OutStreamer->EmitInstruction(MCInstBuilder(AArch64::SUBSWrs)
362                                        .addReg(AArch64::WZR)
363                                        .addReg(AArch64::W16)
364                                        .addReg(AArch64::W17)
365                                        .addImm(0),
366                                    *STI);
367       OutStreamer->EmitInstruction(
368           MCInstBuilder(AArch64::Bcc)
369               .addImm(AArch64CC::LS)
370               .addExpr(MCSymbolRefExpr::create(HandleMismatchSym, OutContext)),
371           *STI);
372 
373       OutStreamer->EmitInstruction(
374           MCInstBuilder(AArch64::ORRXri)
375               .addReg(AArch64::X16)
376               .addReg(Reg)
377               .addImm(AArch64_AM::encodeLogicalImmediate(0xf, 64)),
378           *STI);
379       OutStreamer->EmitInstruction(MCInstBuilder(AArch64::LDRBBui)
380                                        .addReg(AArch64::W16)
381                                        .addReg(AArch64::X16)
382                                        .addImm(0),
383                                    *STI);
384       OutStreamer->EmitInstruction(
385           MCInstBuilder(AArch64::SUBSXrs)
386               .addReg(AArch64::XZR)
387               .addReg(AArch64::X16)
388               .addReg(Reg)
389               .addImm(AArch64_AM::getShifterImm(AArch64_AM::LSR, 56)),
390           *STI);
391       OutStreamer->EmitInstruction(
392           MCInstBuilder(AArch64::Bcc)
393               .addImm(AArch64CC::EQ)
394               .addExpr(MCSymbolRefExpr::create(ReturnSym, OutContext)),
395           *STI);
396 
397       OutStreamer->EmitLabel(HandleMismatchSym);
398     }
399 
400     OutStreamer->EmitInstruction(MCInstBuilder(AArch64::STPXpre)
401                                      .addReg(AArch64::SP)
402                                      .addReg(AArch64::X0)
403                                      .addReg(AArch64::X1)
404                                      .addReg(AArch64::SP)
405                                      .addImm(-32),
406                                  *STI);
407     OutStreamer->EmitInstruction(MCInstBuilder(AArch64::STPXi)
408                                      .addReg(AArch64::FP)
409                                      .addReg(AArch64::LR)
410                                      .addReg(AArch64::SP)
411                                      .addImm(29),
412                                  *STI);
413 
414     if (Reg != AArch64::X0)
415       OutStreamer->EmitInstruction(MCInstBuilder(AArch64::ORRXrs)
416                                        .addReg(AArch64::X0)
417                                        .addReg(AArch64::XZR)
418                                        .addReg(Reg)
419                                        .addImm(0),
420                                    *STI);
421     OutStreamer->EmitInstruction(MCInstBuilder(AArch64::MOVZXi)
422                                      .addReg(AArch64::X1)
423                                      .addImm(AccessInfo)
424                                      .addImm(0),
425                                  *STI);
426 
427     // Intentionally load the GOT entry and branch to it, rather than possibly
428     // late binding the function, which may clobber the registers before we have
429     // a chance to save them.
430     OutStreamer->EmitInstruction(
431         MCInstBuilder(AArch64::ADRP)
432             .addReg(AArch64::X16)
433             .addExpr(AArch64MCExpr::create(
434                 HwasanTagMismatchRef, AArch64MCExpr::VariantKind::VK_GOT_PAGE,
435                 OutContext)),
436         *STI);
437     OutStreamer->EmitInstruction(
438         MCInstBuilder(AArch64::LDRXui)
439             .addReg(AArch64::X16)
440             .addReg(AArch64::X16)
441             .addExpr(AArch64MCExpr::create(
442                 HwasanTagMismatchRef, AArch64MCExpr::VariantKind::VK_GOT_LO12,
443                 OutContext)),
444         *STI);
445     OutStreamer->EmitInstruction(
446         MCInstBuilder(AArch64::BR).addReg(AArch64::X16), *STI);
447   }
448 }
449 
450 void AArch64AsmPrinter::EmitEndOfAsmFile(Module &M) {
451   EmitHwasanMemaccessSymbols(M);
452 
453   const Triple &TT = TM.getTargetTriple();
454   if (TT.isOSBinFormatMachO()) {
455     // Funny Darwin hack: This flag tells the linker that no global symbols
456     // contain code that falls through to other global symbols (e.g. the obvious
457     // implementation of multiple entry points).  If this doesn't occur, the
458     // linker can safely perform dead code stripping.  Since LLVM never
459     // generates code that does this, it is always safe to set.
460     OutStreamer->EmitAssemblerFlag(MCAF_SubsectionsViaSymbols);
461     emitStackMaps(SM);
462   }
463 }
464 
465 void AArch64AsmPrinter::EmitLOHs() {
466   SmallVector<MCSymbol *, 3> MCArgs;
467 
468   for (const auto &D : AArch64FI->getLOHContainer()) {
469     for (const MachineInstr *MI : D.getArgs()) {
470       MInstToMCSymbol::iterator LabelIt = LOHInstToLabel.find(MI);
471       assert(LabelIt != LOHInstToLabel.end() &&
472              "Label hasn't been inserted for LOH related instruction");
473       MCArgs.push_back(LabelIt->second);
474     }
475     OutStreamer->EmitLOHDirective(D.getKind(), MCArgs);
476     MCArgs.clear();
477   }
478 }
479 
480 void AArch64AsmPrinter::EmitFunctionBodyEnd() {
481   if (!AArch64FI->getLOHRelated().empty())
482     EmitLOHs();
483 }
484 
485 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
486 MCSymbol *AArch64AsmPrinter::GetCPISymbol(unsigned CPID) const {
487   // Darwin uses a linker-private symbol name for constant-pools (to
488   // avoid addends on the relocation?), ELF has no such concept and
489   // uses a normal private symbol.
490   if (!getDataLayout().getLinkerPrivateGlobalPrefix().empty())
491     return OutContext.getOrCreateSymbol(
492         Twine(getDataLayout().getLinkerPrivateGlobalPrefix()) + "CPI" +
493         Twine(getFunctionNumber()) + "_" + Twine(CPID));
494 
495   return AsmPrinter::GetCPISymbol(CPID);
496 }
497 
498 void AArch64AsmPrinter::printOperand(const MachineInstr *MI, unsigned OpNum,
499                                      raw_ostream &O) {
500   const MachineOperand &MO = MI->getOperand(OpNum);
501   switch (MO.getType()) {
502   default:
503     llvm_unreachable("<unknown operand type>");
504   case MachineOperand::MO_Register: {
505     Register Reg = MO.getReg();
506     assert(Register::isPhysicalRegister(Reg));
507     assert(!MO.getSubReg() && "Subregs should be eliminated!");
508     O << AArch64InstPrinter::getRegisterName(Reg);
509     break;
510   }
511   case MachineOperand::MO_Immediate: {
512     O << MO.getImm();
513     break;
514   }
515   case MachineOperand::MO_GlobalAddress: {
516     PrintSymbolOperand(MO, O);
517     break;
518   }
519   case MachineOperand::MO_BlockAddress: {
520     MCSymbol *Sym = GetBlockAddressSymbol(MO.getBlockAddress());
521     Sym->print(O, MAI);
522     break;
523   }
524   }
525 }
526 
527 bool AArch64AsmPrinter::printAsmMRegister(const MachineOperand &MO, char Mode,
528                                           raw_ostream &O) {
529   Register Reg = MO.getReg();
530   switch (Mode) {
531   default:
532     return true; // Unknown mode.
533   case 'w':
534     Reg = getWRegFromXReg(Reg);
535     break;
536   case 'x':
537     Reg = getXRegFromWReg(Reg);
538     break;
539   }
540 
541   O << AArch64InstPrinter::getRegisterName(Reg);
542   return false;
543 }
544 
545 // Prints the register in MO using class RC using the offset in the
546 // new register class. This should not be used for cross class
547 // printing.
548 bool AArch64AsmPrinter::printAsmRegInClass(const MachineOperand &MO,
549                                            const TargetRegisterClass *RC,
550                                            unsigned AltName, raw_ostream &O) {
551   assert(MO.isReg() && "Should only get here with a register!");
552   const TargetRegisterInfo *RI = STI->getRegisterInfo();
553   Register Reg = MO.getReg();
554   unsigned RegToPrint = RC->getRegister(RI->getEncodingValue(Reg));
555   assert(RI->regsOverlap(RegToPrint, Reg));
556   O << AArch64InstPrinter::getRegisterName(RegToPrint, AltName);
557   return false;
558 }
559 
560 bool AArch64AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNum,
561                                         const char *ExtraCode, raw_ostream &O) {
562   const MachineOperand &MO = MI->getOperand(OpNum);
563 
564   // First try the generic code, which knows about modifiers like 'c' and 'n'.
565   if (!AsmPrinter::PrintAsmOperand(MI, OpNum, ExtraCode, O))
566     return false;
567 
568   // Does this asm operand have a single letter operand modifier?
569   if (ExtraCode && ExtraCode[0]) {
570     if (ExtraCode[1] != 0)
571       return true; // Unknown modifier.
572 
573     switch (ExtraCode[0]) {
574     default:
575       return true; // Unknown modifier.
576     case 'w':      // Print W register
577     case 'x':      // Print X register
578       if (MO.isReg())
579         return printAsmMRegister(MO, ExtraCode[0], O);
580       if (MO.isImm() && MO.getImm() == 0) {
581         unsigned Reg = ExtraCode[0] == 'w' ? AArch64::WZR : AArch64::XZR;
582         O << AArch64InstPrinter::getRegisterName(Reg);
583         return false;
584       }
585       printOperand(MI, OpNum, O);
586       return false;
587     case 'b': // Print B register.
588     case 'h': // Print H register.
589     case 's': // Print S register.
590     case 'd': // Print D register.
591     case 'q': // Print Q register.
592     case 'z': // Print Z register.
593       if (MO.isReg()) {
594         const TargetRegisterClass *RC;
595         switch (ExtraCode[0]) {
596         case 'b':
597           RC = &AArch64::FPR8RegClass;
598           break;
599         case 'h':
600           RC = &AArch64::FPR16RegClass;
601           break;
602         case 's':
603           RC = &AArch64::FPR32RegClass;
604           break;
605         case 'd':
606           RC = &AArch64::FPR64RegClass;
607           break;
608         case 'q':
609           RC = &AArch64::FPR128RegClass;
610           break;
611         case 'z':
612           RC = &AArch64::ZPRRegClass;
613           break;
614         default:
615           return true;
616         }
617         return printAsmRegInClass(MO, RC, AArch64::NoRegAltName, O);
618       }
619       printOperand(MI, OpNum, O);
620       return false;
621     }
622   }
623 
624   // According to ARM, we should emit x and v registers unless we have a
625   // modifier.
626   if (MO.isReg()) {
627     Register Reg = MO.getReg();
628 
629     // If this is a w or x register, print an x register.
630     if (AArch64::GPR32allRegClass.contains(Reg) ||
631         AArch64::GPR64allRegClass.contains(Reg))
632       return printAsmMRegister(MO, 'x', O);
633 
634     unsigned AltName = AArch64::NoRegAltName;
635     const TargetRegisterClass *RegClass;
636     if (AArch64::ZPRRegClass.contains(Reg)) {
637       RegClass = &AArch64::ZPRRegClass;
638     } else if (AArch64::PPRRegClass.contains(Reg)) {
639       RegClass = &AArch64::PPRRegClass;
640     } else {
641       RegClass = &AArch64::FPR128RegClass;
642       AltName = AArch64::vreg;
643     }
644 
645     // If this is a b, h, s, d, or q register, print it as a v register.
646     return printAsmRegInClass(MO, RegClass, AltName, O);
647   }
648 
649   printOperand(MI, OpNum, O);
650   return false;
651 }
652 
653 bool AArch64AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,
654                                               unsigned OpNum,
655                                               const char *ExtraCode,
656                                               raw_ostream &O) {
657   if (ExtraCode && ExtraCode[0] && ExtraCode[0] != 'a')
658     return true; // Unknown modifier.
659 
660   const MachineOperand &MO = MI->getOperand(OpNum);
661   assert(MO.isReg() && "unexpected inline asm memory operand");
662   O << "[" << AArch64InstPrinter::getRegisterName(MO.getReg()) << "]";
663   return false;
664 }
665 
666 void AArch64AsmPrinter::PrintDebugValueComment(const MachineInstr *MI,
667                                                raw_ostream &OS) {
668   unsigned NOps = MI->getNumOperands();
669   assert(NOps == 4);
670   OS << '\t' << MAI->getCommentString() << "DEBUG_VALUE: ";
671   // cast away const; DIetc do not take const operands for some reason.
672   OS << cast<DILocalVariable>(MI->getOperand(NOps - 2).getMetadata())
673             ->getName();
674   OS << " <- ";
675   // Frame address.  Currently handles register +- offset only.
676   assert(MI->getOperand(0).isReg() && MI->getOperand(1).isImm());
677   OS << '[';
678   printOperand(MI, 0, OS);
679   OS << '+';
680   printOperand(MI, 1, OS);
681   OS << ']';
682   OS << "+";
683   printOperand(MI, NOps - 2, OS);
684 }
685 
686 void AArch64AsmPrinter::EmitJumpTableInfo() {
687   const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
688   if (!MJTI) return;
689 
690   const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
691   if (JT.empty()) return;
692 
693   const Function &F = MF->getFunction();
694   const TargetLoweringObjectFile &TLOF = getObjFileLowering();
695   bool JTInDiffSection =
696       !STI->isTargetCOFF() ||
697       !TLOF.shouldPutJumpTableInFunctionSection(
698           MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32,
699           F);
700   if (JTInDiffSection) {
701       // Drop it in the readonly section.
702       MCSection *ReadOnlySec = TLOF.getSectionForJumpTable(F, TM);
703       OutStreamer->SwitchSection(ReadOnlySec);
704   }
705 
706   auto AFI = MF->getInfo<AArch64FunctionInfo>();
707   for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
708     const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
709 
710     // If this jump table was deleted, ignore it.
711     if (JTBBs.empty()) continue;
712 
713     unsigned Size = AFI->getJumpTableEntrySize(JTI);
714     EmitAlignment(Align(Size));
715     OutStreamer->EmitLabel(GetJTISymbol(JTI));
716 
717     for (auto *JTBB : JTBBs)
718       emitJumpTableEntry(MJTI, JTBB, JTI);
719   }
720 }
721 
722 void AArch64AsmPrinter::emitJumpTableEntry(const MachineJumpTableInfo *MJTI,
723                                            const MachineBasicBlock *MBB,
724                                            unsigned JTI) {
725   const MCExpr *Value = MCSymbolRefExpr::create(MBB->getSymbol(), OutContext);
726   auto AFI = MF->getInfo<AArch64FunctionInfo>();
727   unsigned Size = AFI->getJumpTableEntrySize(JTI);
728 
729   if (Size == 4) {
730     // .word LBB - LJTI
731     const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
732     const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF, JTI, OutContext);
733     Value = MCBinaryExpr::createSub(Value, Base, OutContext);
734   } else {
735     // .byte (LBB - LBB) >> 2 (or .hword)
736     const MCSymbol *BaseSym = AFI->getJumpTableEntryPCRelSymbol(JTI);
737     const MCExpr *Base = MCSymbolRefExpr::create(BaseSym, OutContext);
738     Value = MCBinaryExpr::createSub(Value, Base, OutContext);
739     Value = MCBinaryExpr::createLShr(
740         Value, MCConstantExpr::create(2, OutContext), OutContext);
741   }
742 
743   OutStreamer->EmitValue(Value, Size);
744 }
745 
746 /// Small jump tables contain an unsigned byte or half, representing the offset
747 /// from the lowest-addressed possible destination to the desired basic
748 /// block. Since all instructions are 4-byte aligned, this is further compressed
749 /// by counting in instructions rather than bytes (i.e. divided by 4). So, to
750 /// materialize the correct destination we need:
751 ///
752 ///             adr xDest, .LBB0_0
753 ///             ldrb wScratch, [xTable, xEntry]   (with "lsl #1" for ldrh).
754 ///             add xDest, xDest, xScratch, lsl #2
755 void AArch64AsmPrinter::LowerJumpTableDestSmall(llvm::MCStreamer &OutStreamer,
756                                                 const llvm::MachineInstr &MI) {
757   Register DestReg = MI.getOperand(0).getReg();
758   Register ScratchReg = MI.getOperand(1).getReg();
759   Register ScratchRegW =
760       STI->getRegisterInfo()->getSubReg(ScratchReg, AArch64::sub_32);
761   Register TableReg = MI.getOperand(2).getReg();
762   Register EntryReg = MI.getOperand(3).getReg();
763   int JTIdx = MI.getOperand(4).getIndex();
764   bool IsByteEntry = MI.getOpcode() == AArch64::JumpTableDest8;
765 
766   // This has to be first because the compression pass based its reachability
767   // calculations on the start of the JumpTableDest instruction.
768   auto Label =
769       MF->getInfo<AArch64FunctionInfo>()->getJumpTableEntryPCRelSymbol(JTIdx);
770   EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::ADR)
771                                   .addReg(DestReg)
772                                   .addExpr(MCSymbolRefExpr::create(
773                                       Label, MF->getContext())));
774 
775   // Load the number of instruction-steps to offset from the label.
776   unsigned LdrOpcode = IsByteEntry ? AArch64::LDRBBroX : AArch64::LDRHHroX;
777   EmitToStreamer(OutStreamer, MCInstBuilder(LdrOpcode)
778                                   .addReg(ScratchRegW)
779                                   .addReg(TableReg)
780                                   .addReg(EntryReg)
781                                   .addImm(0)
782                                   .addImm(IsByteEntry ? 0 : 1));
783 
784   // Multiply the steps by 4 and add to the already materialized base label
785   // address.
786   EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::ADDXrs)
787                                   .addReg(DestReg)
788                                   .addReg(DestReg)
789                                   .addReg(ScratchReg)
790                                   .addImm(2));
791 }
792 
793 void AArch64AsmPrinter::LowerSTACKMAP(MCStreamer &OutStreamer, StackMaps &SM,
794                                       const MachineInstr &MI) {
795   unsigned NumNOPBytes = StackMapOpers(&MI).getNumPatchBytes();
796 
797   SM.recordStackMap(MI);
798   assert(NumNOPBytes % 4 == 0 && "Invalid number of NOP bytes requested!");
799 
800   // Scan ahead to trim the shadow.
801   const MachineBasicBlock &MBB = *MI.getParent();
802   MachineBasicBlock::const_iterator MII(MI);
803   ++MII;
804   while (NumNOPBytes > 0) {
805     if (MII == MBB.end() || MII->isCall() ||
806         MII->getOpcode() == AArch64::DBG_VALUE ||
807         MII->getOpcode() == TargetOpcode::PATCHPOINT ||
808         MII->getOpcode() == TargetOpcode::STACKMAP)
809       break;
810     ++MII;
811     NumNOPBytes -= 4;
812   }
813 
814   // Emit nops.
815   for (unsigned i = 0; i < NumNOPBytes; i += 4)
816     EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::HINT).addImm(0));
817 }
818 
819 // Lower a patchpoint of the form:
820 // [<def>], <id>, <numBytes>, <target>, <numArgs>
821 void AArch64AsmPrinter::LowerPATCHPOINT(MCStreamer &OutStreamer, StackMaps &SM,
822                                         const MachineInstr &MI) {
823   SM.recordPatchPoint(MI);
824 
825   PatchPointOpers Opers(&MI);
826 
827   int64_t CallTarget = Opers.getCallTarget().getImm();
828   unsigned EncodedBytes = 0;
829   if (CallTarget) {
830     assert((CallTarget & 0xFFFFFFFFFFFF) == CallTarget &&
831            "High 16 bits of call target should be zero.");
832     Register ScratchReg = MI.getOperand(Opers.getNextScratchIdx()).getReg();
833     EncodedBytes = 16;
834     // Materialize the jump address:
835     EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::MOVZXi)
836                                     .addReg(ScratchReg)
837                                     .addImm((CallTarget >> 32) & 0xFFFF)
838                                     .addImm(32));
839     EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::MOVKXi)
840                                     .addReg(ScratchReg)
841                                     .addReg(ScratchReg)
842                                     .addImm((CallTarget >> 16) & 0xFFFF)
843                                     .addImm(16));
844     EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::MOVKXi)
845                                     .addReg(ScratchReg)
846                                     .addReg(ScratchReg)
847                                     .addImm(CallTarget & 0xFFFF)
848                                     .addImm(0));
849     EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::BLR).addReg(ScratchReg));
850   }
851   // Emit padding.
852   unsigned NumBytes = Opers.getNumPatchBytes();
853   assert(NumBytes >= EncodedBytes &&
854          "Patchpoint can't request size less than the length of a call.");
855   assert((NumBytes - EncodedBytes) % 4 == 0 &&
856          "Invalid number of NOP bytes requested!");
857   for (unsigned i = EncodedBytes; i < NumBytes; i += 4)
858     EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::HINT).addImm(0));
859 }
860 
861 void AArch64AsmPrinter::EmitFMov0(const MachineInstr &MI) {
862   Register DestReg = MI.getOperand(0).getReg();
863   if (STI->hasZeroCycleZeroingFP() && !STI->hasZeroCycleZeroingFPWorkaround()) {
864     // Convert H/S/D register to corresponding Q register
865     if (AArch64::H0 <= DestReg && DestReg <= AArch64::H31)
866       DestReg = AArch64::Q0 + (DestReg - AArch64::H0);
867     else if (AArch64::S0 <= DestReg && DestReg <= AArch64::S31)
868       DestReg = AArch64::Q0 + (DestReg - AArch64::S0);
869     else {
870       assert(AArch64::D0 <= DestReg && DestReg <= AArch64::D31);
871       DestReg = AArch64::Q0 + (DestReg - AArch64::D0);
872     }
873     MCInst MOVI;
874     MOVI.setOpcode(AArch64::MOVIv2d_ns);
875     MOVI.addOperand(MCOperand::createReg(DestReg));
876     MOVI.addOperand(MCOperand::createImm(0));
877     EmitToStreamer(*OutStreamer, MOVI);
878   } else {
879     MCInst FMov;
880     switch (MI.getOpcode()) {
881     default: llvm_unreachable("Unexpected opcode");
882     case AArch64::FMOVH0:
883       FMov.setOpcode(AArch64::FMOVWHr);
884       FMov.addOperand(MCOperand::createReg(DestReg));
885       FMov.addOperand(MCOperand::createReg(AArch64::WZR));
886       break;
887     case AArch64::FMOVS0:
888       FMov.setOpcode(AArch64::FMOVWSr);
889       FMov.addOperand(MCOperand::createReg(DestReg));
890       FMov.addOperand(MCOperand::createReg(AArch64::WZR));
891       break;
892     case AArch64::FMOVD0:
893       FMov.setOpcode(AArch64::FMOVXDr);
894       FMov.addOperand(MCOperand::createReg(DestReg));
895       FMov.addOperand(MCOperand::createReg(AArch64::XZR));
896       break;
897     }
898     EmitToStreamer(*OutStreamer, FMov);
899   }
900 }
901 
902 // Simple pseudo-instructions have their lowering (with expansion to real
903 // instructions) auto-generated.
904 #include "AArch64GenMCPseudoLowering.inc"
905 
906 void AArch64AsmPrinter::EmitInstruction(const MachineInstr *MI) {
907   // Do any auto-generated pseudo lowerings.
908   if (emitPseudoExpansionLowering(*OutStreamer, MI))
909     return;
910 
911   if (AArch64FI->getLOHRelated().count(MI)) {
912     // Generate a label for LOH related instruction
913     MCSymbol *LOHLabel = createTempSymbol("loh");
914     // Associate the instruction with the label
915     LOHInstToLabel[MI] = LOHLabel;
916     OutStreamer->EmitLabel(LOHLabel);
917   }
918 
919   AArch64TargetStreamer *TS =
920     static_cast<AArch64TargetStreamer *>(OutStreamer->getTargetStreamer());
921   // Do any manual lowerings.
922   switch (MI->getOpcode()) {
923   default:
924     break;
925     case AArch64::MOVMCSym: {
926       Register DestReg = MI->getOperand(0).getReg();
927       const MachineOperand &MO_Sym = MI->getOperand(1);
928       MachineOperand Hi_MOSym(MO_Sym), Lo_MOSym(MO_Sym);
929       MCOperand Hi_MCSym, Lo_MCSym;
930 
931       Hi_MOSym.setTargetFlags(AArch64II::MO_G1 | AArch64II::MO_S);
932       Lo_MOSym.setTargetFlags(AArch64II::MO_G0 | AArch64II::MO_NC);
933 
934       MCInstLowering.lowerOperand(Hi_MOSym, Hi_MCSym);
935       MCInstLowering.lowerOperand(Lo_MOSym, Lo_MCSym);
936 
937       MCInst MovZ;
938       MovZ.setOpcode(AArch64::MOVZXi);
939       MovZ.addOperand(MCOperand::createReg(DestReg));
940       MovZ.addOperand(Hi_MCSym);
941       MovZ.addOperand(MCOperand::createImm(16));
942       EmitToStreamer(*OutStreamer, MovZ);
943 
944       MCInst MovK;
945       MovK.setOpcode(AArch64::MOVKXi);
946       MovK.addOperand(MCOperand::createReg(DestReg));
947       MovK.addOperand(MCOperand::createReg(DestReg));
948       MovK.addOperand(Lo_MCSym);
949       MovK.addOperand(MCOperand::createImm(0));
950       EmitToStreamer(*OutStreamer, MovK);
951       return;
952   }
953   case AArch64::MOVIv2d_ns:
954     // If the target has <rdar://problem/16473581>, lower this
955     // instruction to movi.16b instead.
956     if (STI->hasZeroCycleZeroingFPWorkaround() &&
957         MI->getOperand(1).getImm() == 0) {
958       MCInst TmpInst;
959       TmpInst.setOpcode(AArch64::MOVIv16b_ns);
960       TmpInst.addOperand(MCOperand::createReg(MI->getOperand(0).getReg()));
961       TmpInst.addOperand(MCOperand::createImm(MI->getOperand(1).getImm()));
962       EmitToStreamer(*OutStreamer, TmpInst);
963       return;
964     }
965     break;
966 
967   case AArch64::DBG_VALUE: {
968     if (isVerbose() && OutStreamer->hasRawTextSupport()) {
969       SmallString<128> TmpStr;
970       raw_svector_ostream OS(TmpStr);
971       PrintDebugValueComment(MI, OS);
972       OutStreamer->EmitRawText(StringRef(OS.str()));
973     }
974     return;
975 
976   case AArch64::EMITBKEY: {
977       ExceptionHandling ExceptionHandlingType = MAI->getExceptionHandlingType();
978       if (ExceptionHandlingType != ExceptionHandling::DwarfCFI &&
979           ExceptionHandlingType != ExceptionHandling::ARM)
980         return;
981 
982       if (needsCFIMoves() == CFI_M_None)
983         return;
984 
985       OutStreamer->EmitCFIBKeyFrame();
986       return;
987     }
988   }
989 
990   // Tail calls use pseudo instructions so they have the proper code-gen
991   // attributes (isCall, isReturn, etc.). We lower them to the real
992   // instruction here.
993   case AArch64::TCRETURNri:
994   case AArch64::TCRETURNriBTI:
995   case AArch64::TCRETURNriALL: {
996     MCInst TmpInst;
997     TmpInst.setOpcode(AArch64::BR);
998     TmpInst.addOperand(MCOperand::createReg(MI->getOperand(0).getReg()));
999     EmitToStreamer(*OutStreamer, TmpInst);
1000     return;
1001   }
1002   case AArch64::TCRETURNdi: {
1003     MCOperand Dest;
1004     MCInstLowering.lowerOperand(MI->getOperand(0), Dest);
1005     MCInst TmpInst;
1006     TmpInst.setOpcode(AArch64::B);
1007     TmpInst.addOperand(Dest);
1008     EmitToStreamer(*OutStreamer, TmpInst);
1009     return;
1010   }
1011   case AArch64::TLSDESC_CALLSEQ: {
1012     /// lower this to:
1013     ///    adrp  x0, :tlsdesc:var
1014     ///    ldr   x1, [x0, #:tlsdesc_lo12:var]
1015     ///    add   x0, x0, #:tlsdesc_lo12:var
1016     ///    .tlsdesccall var
1017     ///    blr   x1
1018     ///    (TPIDR_EL0 offset now in x0)
1019     const MachineOperand &MO_Sym = MI->getOperand(0);
1020     MachineOperand MO_TLSDESC_LO12(MO_Sym), MO_TLSDESC(MO_Sym);
1021     MCOperand Sym, SymTLSDescLo12, SymTLSDesc;
1022     MO_TLSDESC_LO12.setTargetFlags(AArch64II::MO_TLS | AArch64II::MO_PAGEOFF);
1023     MO_TLSDESC.setTargetFlags(AArch64II::MO_TLS | AArch64II::MO_PAGE);
1024     MCInstLowering.lowerOperand(MO_Sym, Sym);
1025     MCInstLowering.lowerOperand(MO_TLSDESC_LO12, SymTLSDescLo12);
1026     MCInstLowering.lowerOperand(MO_TLSDESC, SymTLSDesc);
1027 
1028     MCInst Adrp;
1029     Adrp.setOpcode(AArch64::ADRP);
1030     Adrp.addOperand(MCOperand::createReg(AArch64::X0));
1031     Adrp.addOperand(SymTLSDesc);
1032     EmitToStreamer(*OutStreamer, Adrp);
1033 
1034     MCInst Ldr;
1035     Ldr.setOpcode(AArch64::LDRXui);
1036     Ldr.addOperand(MCOperand::createReg(AArch64::X1));
1037     Ldr.addOperand(MCOperand::createReg(AArch64::X0));
1038     Ldr.addOperand(SymTLSDescLo12);
1039     Ldr.addOperand(MCOperand::createImm(0));
1040     EmitToStreamer(*OutStreamer, Ldr);
1041 
1042     MCInst Add;
1043     Add.setOpcode(AArch64::ADDXri);
1044     Add.addOperand(MCOperand::createReg(AArch64::X0));
1045     Add.addOperand(MCOperand::createReg(AArch64::X0));
1046     Add.addOperand(SymTLSDescLo12);
1047     Add.addOperand(MCOperand::createImm(AArch64_AM::getShiftValue(0)));
1048     EmitToStreamer(*OutStreamer, Add);
1049 
1050     // Emit a relocation-annotation. This expands to no code, but requests
1051     // the following instruction gets an R_AARCH64_TLSDESC_CALL.
1052     MCInst TLSDescCall;
1053     TLSDescCall.setOpcode(AArch64::TLSDESCCALL);
1054     TLSDescCall.addOperand(Sym);
1055     EmitToStreamer(*OutStreamer, TLSDescCall);
1056 
1057     MCInst Blr;
1058     Blr.setOpcode(AArch64::BLR);
1059     Blr.addOperand(MCOperand::createReg(AArch64::X1));
1060     EmitToStreamer(*OutStreamer, Blr);
1061 
1062     return;
1063   }
1064 
1065   case AArch64::JumpTableDest32: {
1066     // We want:
1067     //     ldrsw xScratch, [xTable, xEntry, lsl #2]
1068     //     add xDest, xTable, xScratch
1069     unsigned DestReg = MI->getOperand(0).getReg(),
1070              ScratchReg = MI->getOperand(1).getReg(),
1071              TableReg = MI->getOperand(2).getReg(),
1072              EntryReg = MI->getOperand(3).getReg();
1073     EmitToStreamer(*OutStreamer, MCInstBuilder(AArch64::LDRSWroX)
1074                                      .addReg(ScratchReg)
1075                                      .addReg(TableReg)
1076                                      .addReg(EntryReg)
1077                                      .addImm(0)
1078                                      .addImm(1));
1079     EmitToStreamer(*OutStreamer, MCInstBuilder(AArch64::ADDXrs)
1080                                      .addReg(DestReg)
1081                                      .addReg(TableReg)
1082                                      .addReg(ScratchReg)
1083                                      .addImm(0));
1084     return;
1085   }
1086   case AArch64::JumpTableDest16:
1087   case AArch64::JumpTableDest8:
1088     LowerJumpTableDestSmall(*OutStreamer, *MI);
1089     return;
1090 
1091   case AArch64::FMOVH0:
1092   case AArch64::FMOVS0:
1093   case AArch64::FMOVD0:
1094     EmitFMov0(*MI);
1095     return;
1096 
1097   case TargetOpcode::STACKMAP:
1098     return LowerSTACKMAP(*OutStreamer, SM, *MI);
1099 
1100   case TargetOpcode::PATCHPOINT:
1101     return LowerPATCHPOINT(*OutStreamer, SM, *MI);
1102 
1103   case TargetOpcode::PATCHABLE_FUNCTION_ENTER:
1104     LowerPATCHABLE_FUNCTION_ENTER(*MI);
1105     return;
1106 
1107   case TargetOpcode::PATCHABLE_FUNCTION_EXIT:
1108     LowerPATCHABLE_FUNCTION_EXIT(*MI);
1109     return;
1110 
1111   case TargetOpcode::PATCHABLE_TAIL_CALL:
1112     LowerPATCHABLE_TAIL_CALL(*MI);
1113     return;
1114 
1115   case AArch64::HWASAN_CHECK_MEMACCESS:
1116   case AArch64::HWASAN_CHECK_MEMACCESS_SHORTGRANULES:
1117     LowerHWASAN_CHECK_MEMACCESS(*MI);
1118     return;
1119 
1120   case AArch64::SEH_StackAlloc:
1121     TS->EmitARM64WinCFIAllocStack(MI->getOperand(0).getImm());
1122     return;
1123 
1124   case AArch64::SEH_SaveFPLR:
1125     TS->EmitARM64WinCFISaveFPLR(MI->getOperand(0).getImm());
1126     return;
1127 
1128   case AArch64::SEH_SaveFPLR_X:
1129     assert(MI->getOperand(0).getImm() < 0 &&
1130            "Pre increment SEH opcode must have a negative offset");
1131     TS->EmitARM64WinCFISaveFPLRX(-MI->getOperand(0).getImm());
1132     return;
1133 
1134   case AArch64::SEH_SaveReg:
1135     TS->EmitARM64WinCFISaveReg(MI->getOperand(0).getImm(),
1136                                MI->getOperand(1).getImm());
1137     return;
1138 
1139   case AArch64::SEH_SaveReg_X:
1140     assert(MI->getOperand(1).getImm() < 0 &&
1141            "Pre increment SEH opcode must have a negative offset");
1142     TS->EmitARM64WinCFISaveRegX(MI->getOperand(0).getImm(),
1143 		                -MI->getOperand(1).getImm());
1144     return;
1145 
1146   case AArch64::SEH_SaveRegP:
1147     assert((MI->getOperand(1).getImm() - MI->getOperand(0).getImm() == 1) &&
1148             "Non-consecutive registers not allowed for save_regp");
1149     TS->EmitARM64WinCFISaveRegP(MI->getOperand(0).getImm(),
1150                                 MI->getOperand(2).getImm());
1151     return;
1152 
1153   case AArch64::SEH_SaveRegP_X:
1154     assert((MI->getOperand(1).getImm() - MI->getOperand(0).getImm() == 1) &&
1155             "Non-consecutive registers not allowed for save_regp_x");
1156     assert(MI->getOperand(2).getImm() < 0 &&
1157            "Pre increment SEH opcode must have a negative offset");
1158     TS->EmitARM64WinCFISaveRegPX(MI->getOperand(0).getImm(),
1159                                  -MI->getOperand(2).getImm());
1160     return;
1161 
1162   case AArch64::SEH_SaveFReg:
1163     TS->EmitARM64WinCFISaveFReg(MI->getOperand(0).getImm(),
1164                                 MI->getOperand(1).getImm());
1165     return;
1166 
1167   case AArch64::SEH_SaveFReg_X:
1168     assert(MI->getOperand(1).getImm() < 0 &&
1169            "Pre increment SEH opcode must have a negative offset");
1170     TS->EmitARM64WinCFISaveFRegX(MI->getOperand(0).getImm(),
1171                                  -MI->getOperand(1).getImm());
1172     return;
1173 
1174   case AArch64::SEH_SaveFRegP:
1175     assert((MI->getOperand(1).getImm() - MI->getOperand(0).getImm() == 1) &&
1176             "Non-consecutive registers not allowed for save_regp");
1177     TS->EmitARM64WinCFISaveFRegP(MI->getOperand(0).getImm(),
1178                                  MI->getOperand(2).getImm());
1179     return;
1180 
1181   case AArch64::SEH_SaveFRegP_X:
1182     assert((MI->getOperand(1).getImm() - MI->getOperand(0).getImm() == 1) &&
1183             "Non-consecutive registers not allowed for save_regp_x");
1184     assert(MI->getOperand(2).getImm() < 0 &&
1185            "Pre increment SEH opcode must have a negative offset");
1186     TS->EmitARM64WinCFISaveFRegPX(MI->getOperand(0).getImm(),
1187                                   -MI->getOperand(2).getImm());
1188     return;
1189 
1190   case AArch64::SEH_SetFP:
1191     TS->EmitARM64WinCFISetFP();
1192     return;
1193 
1194   case AArch64::SEH_AddFP:
1195     TS->EmitARM64WinCFIAddFP(MI->getOperand(0).getImm());
1196     return;
1197 
1198   case AArch64::SEH_Nop:
1199     TS->EmitARM64WinCFINop();
1200     return;
1201 
1202   case AArch64::SEH_PrologEnd:
1203     TS->EmitARM64WinCFIPrologEnd();
1204     return;
1205 
1206   case AArch64::SEH_EpilogStart:
1207     TS->EmitARM64WinCFIEpilogStart();
1208     return;
1209 
1210   case AArch64::SEH_EpilogEnd:
1211     TS->EmitARM64WinCFIEpilogEnd();
1212     return;
1213   }
1214 
1215   // Finally, do the automated lowerings for everything else.
1216   MCInst TmpInst;
1217   MCInstLowering.Lower(MI, TmpInst);
1218   EmitToStreamer(*OutStreamer, TmpInst);
1219 }
1220 
1221 // Force static initialization.
1222 extern "C" void LLVMInitializeAArch64AsmPrinter() {
1223   RegisterAsmPrinter<AArch64AsmPrinter> X(getTheAArch64leTarget());
1224   RegisterAsmPrinter<AArch64AsmPrinter> Y(getTheAArch64beTarget());
1225   RegisterAsmPrinter<AArch64AsmPrinter> Z(getTheARM64Target());
1226   RegisterAsmPrinter<AArch64AsmPrinter> W(getTheARM64_32Target());
1227   RegisterAsmPrinter<AArch64AsmPrinter> V(getTheAArch64_32Target());
1228 }
1229