xref: /freebsd/contrib/llvm-project/llvm/lib/Target/AArch64/Disassembler/AArch64Disassembler.cpp (revision f126890ac5386406dadf7c4cfa9566cbb56537c5)
1 //===- AArch64Disassembler.cpp - Disassembler for AArch64 -----------------===//
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 //
10 //===----------------------------------------------------------------------===//
11 
12 #include "AArch64Disassembler.h"
13 #include "AArch64ExternalSymbolizer.h"
14 #include "MCTargetDesc/AArch64AddressingModes.h"
15 #include "MCTargetDesc/AArch64MCTargetDesc.h"
16 #include "TargetInfo/AArch64TargetInfo.h"
17 #include "Utils/AArch64BaseInfo.h"
18 #include "llvm-c/Disassembler.h"
19 #include "llvm/MC/MCDecoderOps.h"
20 #include "llvm/MC/MCDisassembler/MCRelocationInfo.h"
21 #include "llvm/MC/MCInst.h"
22 #include "llvm/MC/MCInstrDesc.h"
23 #include "llvm/MC/MCRegisterInfo.h"
24 #include "llvm/MC/MCSubtargetInfo.h"
25 #include "llvm/MC/TargetRegistry.h"
26 #include "llvm/Support/Compiler.h"
27 #include "llvm/Support/Debug.h"
28 #include "llvm/Support/ErrorHandling.h"
29 #include <algorithm>
30 #include <memory>
31 
32 using namespace llvm;
33 
34 #define DEBUG_TYPE "aarch64-disassembler"
35 
36 // Pull DecodeStatus and its enum values into the global namespace.
37 using DecodeStatus = MCDisassembler::DecodeStatus;
38 
39 // Forward declare these because the autogenerated code will reference them.
40 // Definitions are further down.
41 static DecodeStatus DecodeFPR128RegisterClass(MCInst &Inst, unsigned RegNo,
42                                               uint64_t Address,
43                                               const MCDisassembler *Decoder);
44 static DecodeStatus DecodeFPR128_loRegisterClass(MCInst &Inst, unsigned RegNo,
45                                                  uint64_t Address,
46                                                  const MCDisassembler *Decoder);
47 static DecodeStatus DecodeFPR64RegisterClass(MCInst &Inst, unsigned RegNo,
48                                              uint64_t Address,
49                                              const MCDisassembler *Decoder);
50 static DecodeStatus DecodeFPR32RegisterClass(MCInst &Inst, unsigned RegNo,
51                                              uint64_t Address,
52                                              const MCDisassembler *Decoder);
53 static DecodeStatus DecodeFPR16RegisterClass(MCInst &Inst, unsigned RegNo,
54                                              uint64_t Address,
55                                              const MCDisassembler *Decoder);
56 static DecodeStatus DecodeFPR8RegisterClass(MCInst &Inst, unsigned RegNo,
57                                             uint64_t Address,
58                                             const MCDisassembler *Decoder);
59 static DecodeStatus
60 DecodeGPR64commonRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Address,
61                                const MCDisassembler *Decoder);
62 static DecodeStatus DecodeGPR64RegisterClass(MCInst &Inst, unsigned RegNo,
63                                              uint64_t Address,
64                                              const MCDisassembler *Decoder);
65 static DecodeStatus
66 DecodeGPR64x8ClassRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Address,
67                                 const MCDisassembler *Decoder);
68 static DecodeStatus DecodeGPR64spRegisterClass(MCInst &Inst, unsigned RegNo,
69                                                uint64_t Address,
70                                                const MCDisassembler *Decoder);
71 static DecodeStatus
72 DecodeMatrixIndexGPR32_8_11RegisterClass(MCInst &Inst, unsigned RegNo,
73                                          uint64_t Address, const void *Decoder);
74 static DecodeStatus
75 DecodeMatrixIndexGPR32_12_15RegisterClass(MCInst &Inst, unsigned RegNo,
76                                           uint64_t Address,
77                                           const MCDisassembler *Decoder);
78 static DecodeStatus DecodeGPR32RegisterClass(MCInst &Inst, unsigned RegNo,
79                                              uint64_t Address,
80                                              const MCDisassembler *Decoder);
81 static DecodeStatus DecodeGPR32spRegisterClass(MCInst &Inst, unsigned RegNo,
82                                                uint64_t Address,
83                                                const MCDisassembler *Decoder);
84 static DecodeStatus DecodeQQRegisterClass(MCInst &Inst, unsigned RegNo,
85                                           uint64_t Address,
86                                           const MCDisassembler *Decoder);
87 static DecodeStatus DecodeQQQRegisterClass(MCInst &Inst, unsigned RegNo,
88                                            uint64_t Address,
89                                            const MCDisassembler *Decoder);
90 static DecodeStatus DecodeQQQQRegisterClass(MCInst &Inst, unsigned RegNo,
91                                             uint64_t Address,
92                                             const MCDisassembler *Decoder);
93 static DecodeStatus DecodeDDRegisterClass(MCInst &Inst, unsigned RegNo,
94                                           uint64_t Address,
95                                           const MCDisassembler *Decoder);
96 static DecodeStatus DecodeDDDRegisterClass(MCInst &Inst, unsigned RegNo,
97                                            uint64_t Address,
98                                            const MCDisassembler *Decoder);
99 static DecodeStatus DecodeDDDDRegisterClass(MCInst &Inst, unsigned RegNo,
100                                             uint64_t Address,
101                                             const MCDisassembler *Decoder);
102 static DecodeStatus DecodeZPRRegisterClass(MCInst &Inst, unsigned RegNo,
103                                            uint64_t Address,
104                                            const MCDisassembler *Decoder);
105 static DecodeStatus DecodeZPR_4bRegisterClass(MCInst &Inst, unsigned RegNo,
106                                               uint64_t Address,
107                                               const MCDisassembler *Decoder);
108 static DecodeStatus DecodeZPR_3bRegisterClass(MCInst &Inst, unsigned RegNo,
109                                               uint64_t Address,
110                                               const MCDisassembler *Decoder);
111 static DecodeStatus DecodeZPR2RegisterClass(MCInst &Inst, unsigned RegNo,
112                                             uint64_t Address,
113                                             const MCDisassembler *Decoder);
114 static DecodeStatus DecodeZPR3RegisterClass(MCInst &Inst, unsigned RegNo,
115                                             uint64_t Address,
116                                             const MCDisassembler *Decoder);
117 static DecodeStatus DecodeZPR4RegisterClass(MCInst &Inst, unsigned RegNo,
118                                             uint64_t Address,
119                                             const MCDisassembler *Decoder);
120 static DecodeStatus DecodeZPR2Mul2RegisterClass(MCInst &Inst, unsigned RegNo,
121                                                 uint64_t Address,
122                                                 const void *Decoder);
123 static DecodeStatus DecodeZPR4Mul4RegisterClass(MCInst &Inst, unsigned RegNo,
124                                                 uint64_t Address,
125                                                 const void *Decoder);
126 static DecodeStatus DecodeZPR2StridedRegisterClass(MCInst &Inst, unsigned RegNo,
127                                                    uint64_t Address,
128                                                    const void *Decoder);
129 static DecodeStatus DecodeZPR4StridedRegisterClass(MCInst &Inst, unsigned RegNo,
130                                                    uint64_t Address,
131                                                    const void *Decoder);
132 template <unsigned NumBitsForTile>
133 static DecodeStatus DecodeMatrixTile(MCInst &Inst, unsigned RegNo,
134                                      uint64_t Address,
135                                      const MCDisassembler *Decoder);
136 static DecodeStatus
137 DecodeMatrixTileListRegisterClass(MCInst &Inst, unsigned RegMask,
138                                   uint64_t Address,
139                                   const MCDisassembler *Decoder);
140 static DecodeStatus DecodePPRRegisterClass(MCInst &Inst, unsigned RegNo,
141                                            uint64_t Address,
142                                            const MCDisassembler *Decoder);
143 static DecodeStatus DecodePPR_3bRegisterClass(MCInst &Inst, unsigned RegNo,
144                                               uint64_t Address,
145                                               const MCDisassembler *Decoder);
146 static DecodeStatus
147 DecodePPR_p8to15RegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Address,
148                               const MCDisassembler *Decoder);
149 static DecodeStatus DecodePPR2RegisterClass(MCInst &Inst, unsigned RegNo,
150                                             uint64_t Address,
151                                             const void *Decoder);
152 static DecodeStatus DecodePPR2Mul2RegisterClass(MCInst &Inst, unsigned RegNo,
153                                                 uint64_t Address,
154                                                 const void *Decoder);
155 
156 static DecodeStatus DecodeFixedPointScaleImm32(MCInst &Inst, unsigned Imm,
157                                                uint64_t Address,
158                                                const MCDisassembler *Decoder);
159 static DecodeStatus DecodeFixedPointScaleImm64(MCInst &Inst, unsigned Imm,
160                                                uint64_t Address,
161                                                const MCDisassembler *Decoder);
162 static DecodeStatus DecodePCRelLabel19(MCInst &Inst, unsigned Imm,
163                                        uint64_t Address,
164                                        const MCDisassembler *Decoder);
165 static DecodeStatus DecodeMemExtend(MCInst &Inst, unsigned Imm,
166                                     uint64_t Address,
167                                     const MCDisassembler *Decoder);
168 static DecodeStatus DecodeMRSSystemRegister(MCInst &Inst, unsigned Imm,
169                                             uint64_t Address,
170                                             const MCDisassembler *Decoder);
171 static DecodeStatus DecodeMSRSystemRegister(MCInst &Inst, unsigned Imm,
172                                             uint64_t Address,
173                                             const MCDisassembler *Decoder);
174 static DecodeStatus
175 DecodeThreeAddrSRegInstruction(MCInst &Inst, uint32_t insn, uint64_t Address,
176                                const MCDisassembler *Decoder);
177 static DecodeStatus DecodeMoveImmInstruction(MCInst &Inst, uint32_t insn,
178                                              uint64_t Address,
179                                              const MCDisassembler *Decoder);
180 static DecodeStatus
181 DecodeUnsignedLdStInstruction(MCInst &Inst, uint32_t insn, uint64_t Address,
182                               const MCDisassembler *Decoder);
183 static DecodeStatus DecodeSignedLdStInstruction(MCInst &Inst, uint32_t insn,
184                                                 uint64_t Address,
185                                                 const MCDisassembler *Decoder);
186 static DecodeStatus
187 DecodeExclusiveLdStInstruction(MCInst &Inst, uint32_t insn, uint64_t Address,
188                                const MCDisassembler *Decoder);
189 static DecodeStatus DecodePairLdStInstruction(MCInst &Inst, uint32_t insn,
190                                               uint64_t Address,
191                                               const MCDisassembler *Decoder);
192 static DecodeStatus DecodeAuthLoadInstruction(MCInst &Inst, uint32_t insn,
193                                               uint64_t Address,
194                                               const MCDisassembler *Decoder);
195 static DecodeStatus DecodeAddSubERegInstruction(MCInst &Inst, uint32_t insn,
196                                                 uint64_t Address,
197                                                 const MCDisassembler *Decoder);
198 static DecodeStatus DecodeLogicalImmInstruction(MCInst &Inst, uint32_t insn,
199                                                 uint64_t Address,
200                                                 const MCDisassembler *Decoder);
201 static DecodeStatus DecodeModImmInstruction(MCInst &Inst, uint32_t insn,
202                                             uint64_t Address,
203                                             const MCDisassembler *Decoder);
204 static DecodeStatus DecodeModImmTiedInstruction(MCInst &Inst, uint32_t insn,
205                                                 uint64_t Address,
206                                                 const MCDisassembler *Decoder);
207 static DecodeStatus DecodeAdrInstruction(MCInst &Inst, uint32_t insn,
208                                          uint64_t Address,
209                                          const MCDisassembler *Decoder);
210 static DecodeStatus DecodeAddSubImmShift(MCInst &Inst, uint32_t insn,
211                                          uint64_t Address,
212                                          const MCDisassembler *Decoder);
213 static DecodeStatus DecodeUnconditionalBranch(MCInst &Inst, uint32_t insn,
214                                               uint64_t Address,
215                                               const MCDisassembler *Decoder);
216 static DecodeStatus
217 DecodeSystemPStateImm0_15Instruction(MCInst &Inst, uint32_t insn,
218                                      uint64_t Address,
219                                      const MCDisassembler *Decoder);
220 static DecodeStatus
221 DecodeSystemPStateImm0_1Instruction(MCInst &Inst, uint32_t insn,
222                                     uint64_t Address,
223                                     const MCDisassembler *Decoder);
224 static DecodeStatus DecodeTestAndBranch(MCInst &Inst, uint32_t insn,
225                                         uint64_t Address,
226                                         const MCDisassembler *Decoder);
227 
228 static DecodeStatus DecodeFMOVLaneInstruction(MCInst &Inst, unsigned Insn,
229                                               uint64_t Address,
230                                               const MCDisassembler *Decoder);
231 static DecodeStatus DecodeVecShiftR64Imm(MCInst &Inst, unsigned Imm,
232                                          uint64_t Addr,
233                                          const MCDisassembler *Decoder);
234 static DecodeStatus DecodeVecShiftR64ImmNarrow(MCInst &Inst, unsigned Imm,
235                                                uint64_t Addr,
236                                                const MCDisassembler *Decoder);
237 static DecodeStatus DecodeVecShiftR32Imm(MCInst &Inst, unsigned Imm,
238                                          uint64_t Addr,
239                                          const MCDisassembler *Decoder);
240 static DecodeStatus DecodeVecShiftR32ImmNarrow(MCInst &Inst, unsigned Imm,
241                                                uint64_t Addr,
242                                                const MCDisassembler *Decoder);
243 static DecodeStatus DecodeVecShiftR16Imm(MCInst &Inst, unsigned Imm,
244                                          uint64_t Addr,
245                                          const MCDisassembler *Decoder);
246 static DecodeStatus DecodeVecShiftR16ImmNarrow(MCInst &Inst, unsigned Imm,
247                                                uint64_t Addr,
248                                                const MCDisassembler *Decoder);
249 static DecodeStatus DecodeVecShiftR8Imm(MCInst &Inst, unsigned Imm,
250                                         uint64_t Addr,
251                                         const MCDisassembler *Decoder);
252 static DecodeStatus DecodeVecShiftL64Imm(MCInst &Inst, unsigned Imm,
253                                          uint64_t Addr,
254                                          const MCDisassembler *Decoder);
255 static DecodeStatus DecodeVecShiftL32Imm(MCInst &Inst, unsigned Imm,
256                                          uint64_t Addr,
257                                          const MCDisassembler *Decoder);
258 static DecodeStatus DecodeVecShiftL16Imm(MCInst &Inst, unsigned Imm,
259                                          uint64_t Addr,
260                                          const MCDisassembler *Decoder);
261 static DecodeStatus DecodeVecShiftL8Imm(MCInst &Inst, unsigned Imm,
262                                         uint64_t Addr,
263                                         const MCDisassembler *Decoder);
264 static DecodeStatus
265 DecodeWSeqPairsClassRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Addr,
266                                   const MCDisassembler *Decoder);
267 static DecodeStatus
268 DecodeXSeqPairsClassRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Addr,
269                                   const MCDisassembler *Decoder);
270 static DecodeStatus DecodeSyspXzrInstruction(MCInst &Inst, uint32_t insn,
271                                              uint64_t Addr,
272                                              const MCDisassembler *Decoder);
273 static DecodeStatus
274 DecodeSVELogicalImmInstruction(MCInst &Inst, uint32_t insn, uint64_t Address,
275                                const MCDisassembler *Decoder);
276 template <int Bits>
277 static DecodeStatus DecodeSImm(MCInst &Inst, uint64_t Imm, uint64_t Address,
278                                const MCDisassembler *Decoder);
279 template <int ElementWidth>
280 static DecodeStatus DecodeImm8OptLsl(MCInst &Inst, unsigned Imm, uint64_t Addr,
281                                      const MCDisassembler *Decoder);
282 static DecodeStatus DecodeSVEIncDecImm(MCInst &Inst, unsigned Imm,
283                                        uint64_t Addr,
284                                        const MCDisassembler *Decoder);
285 static DecodeStatus DecodeSVCROp(MCInst &Inst, unsigned Imm, uint64_t Address,
286                                  const MCDisassembler *Decoder);
287 static DecodeStatus DecodeCPYMemOpInstruction(MCInst &Inst, uint32_t insn,
288                                               uint64_t Addr,
289                                               const MCDisassembler *Decoder);
290 static DecodeStatus DecodeSETMemOpInstruction(MCInst &Inst, uint32_t insn,
291                                               uint64_t Addr,
292                                               const MCDisassembler *Decoder);
293 static DecodeStatus DecodePRFMRegInstruction(MCInst &Inst, uint32_t insn,
294                                              uint64_t Address,
295                                              const MCDisassembler *Decoder);
296 
297 #include "AArch64GenDisassemblerTables.inc"
298 #include "AArch64GenInstrInfo.inc"
299 
300 #define Success MCDisassembler::Success
301 #define Fail MCDisassembler::Fail
302 #define SoftFail MCDisassembler::SoftFail
303 
304 static MCDisassembler *createAArch64Disassembler(const Target &T,
305                                                const MCSubtargetInfo &STI,
306                                                MCContext &Ctx) {
307 
308   return new AArch64Disassembler(STI, Ctx, T.createMCInstrInfo());
309 }
310 
311 DecodeStatus AArch64Disassembler::getInstruction(MCInst &MI, uint64_t &Size,
312                                                  ArrayRef<uint8_t> Bytes,
313                                                  uint64_t Address,
314                                                  raw_ostream &CS) const {
315   CommentStream = &CS;
316 
317   Size = 0;
318   // We want to read exactly 4 bytes of data.
319   if (Bytes.size() < 4)
320     return Fail;
321   Size = 4;
322 
323   // Encoded as a small-endian 32-bit word in the stream.
324   uint32_t Insn =
325       (Bytes[3] << 24) | (Bytes[2] << 16) | (Bytes[1] << 8) | (Bytes[0] << 0);
326 
327   const uint8_t *Tables[] = {DecoderTable32, DecoderTableFallback32};
328 
329   for (const auto *Table : Tables) {
330     DecodeStatus Result =
331         decodeInstruction(Table, MI, Insn, Address, this, STI);
332 
333     const MCInstrDesc &Desc = MCII->get(MI.getOpcode());
334 
335     // For Scalable Matrix Extension (SME) instructions that have an implicit
336     // operand for the accumulator (ZA) or implicit immediate zero which isn't
337     // encoded, manually insert operand.
338     for (unsigned i = 0; i < Desc.getNumOperands(); i++) {
339       if (Desc.operands()[i].OperandType == MCOI::OPERAND_REGISTER) {
340         switch (Desc.operands()[i].RegClass) {
341         default:
342           break;
343         case AArch64::MPRRegClassID:
344           MI.insert(MI.begin() + i, MCOperand::createReg(AArch64::ZA));
345           break;
346         case AArch64::MPR8RegClassID:
347           MI.insert(MI.begin() + i, MCOperand::createReg(AArch64::ZAB0));
348           break;
349         case AArch64::ZTRRegClassID:
350           MI.insert(MI.begin() + i, MCOperand::createReg(AArch64::ZT0));
351           break;
352         }
353       } else if (Desc.operands()[i].OperandType ==
354                  AArch64::OPERAND_IMPLICIT_IMM_0) {
355         MI.insert(MI.begin() + i, MCOperand::createImm(0));
356       }
357     }
358 
359     if (MI.getOpcode() == AArch64::LDR_ZA ||
360         MI.getOpcode() == AArch64::STR_ZA) {
361       // Spill and fill instructions have a single immediate used for both
362       // the vector select offset and optional memory offset. Replicate
363       // the decoded immediate.
364       const MCOperand &Imm4Op = MI.getOperand(2);
365       assert(Imm4Op.isImm() && "Unexpected operand type!");
366       MI.addOperand(Imm4Op);
367     }
368 
369     if (Result != MCDisassembler::Fail)
370       return Result;
371   }
372 
373   return MCDisassembler::Fail;
374 }
375 
376 uint64_t AArch64Disassembler::suggestBytesToSkip(ArrayRef<uint8_t> Bytes,
377                                                  uint64_t Address) const {
378   // AArch64 instructions are always 4 bytes wide, so there's no point
379   // in skipping any smaller number of bytes if an instruction can't
380   // be decoded.
381   return 4;
382 }
383 
384 static MCSymbolizer *
385 createAArch64ExternalSymbolizer(const Triple &TT, LLVMOpInfoCallback GetOpInfo,
386                                 LLVMSymbolLookupCallback SymbolLookUp,
387                                 void *DisInfo, MCContext *Ctx,
388                                 std::unique_ptr<MCRelocationInfo> &&RelInfo) {
389   return new AArch64ExternalSymbolizer(*Ctx, std::move(RelInfo), GetOpInfo,
390                                        SymbolLookUp, DisInfo);
391 }
392 
393 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeAArch64Disassembler() {
394   TargetRegistry::RegisterMCDisassembler(getTheAArch64leTarget(),
395                                          createAArch64Disassembler);
396   TargetRegistry::RegisterMCDisassembler(getTheAArch64beTarget(),
397                                          createAArch64Disassembler);
398   TargetRegistry::RegisterMCSymbolizer(getTheAArch64leTarget(),
399                                        createAArch64ExternalSymbolizer);
400   TargetRegistry::RegisterMCSymbolizer(getTheAArch64beTarget(),
401                                        createAArch64ExternalSymbolizer);
402   TargetRegistry::RegisterMCDisassembler(getTheAArch64_32Target(),
403                                          createAArch64Disassembler);
404   TargetRegistry::RegisterMCSymbolizer(getTheAArch64_32Target(),
405                                        createAArch64ExternalSymbolizer);
406 
407   TargetRegistry::RegisterMCDisassembler(getTheARM64Target(),
408                                          createAArch64Disassembler);
409   TargetRegistry::RegisterMCSymbolizer(getTheARM64Target(),
410                                        createAArch64ExternalSymbolizer);
411   TargetRegistry::RegisterMCDisassembler(getTheARM64_32Target(),
412                                          createAArch64Disassembler);
413   TargetRegistry::RegisterMCSymbolizer(getTheARM64_32Target(),
414                                        createAArch64ExternalSymbolizer);
415 }
416 
417 static DecodeStatus DecodeFPR128RegisterClass(MCInst &Inst, unsigned RegNo,
418                                               uint64_t Addr,
419                                               const MCDisassembler *Decoder) {
420   if (RegNo > 31)
421     return Fail;
422 
423   unsigned Register =
424       AArch64MCRegisterClasses[AArch64::FPR128RegClassID].getRegister(RegNo);
425   Inst.addOperand(MCOperand::createReg(Register));
426   return Success;
427 }
428 
429 static DecodeStatus
430 DecodeFPR128_loRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Addr,
431                              const MCDisassembler *Decoder) {
432   if (RegNo > 15)
433     return Fail;
434   return DecodeFPR128RegisterClass(Inst, RegNo, Addr, Decoder);
435 }
436 
437 static DecodeStatus DecodeFPR64RegisterClass(MCInst &Inst, unsigned RegNo,
438                                              uint64_t Addr,
439                                              const MCDisassembler *Decoder) {
440   if (RegNo > 31)
441     return Fail;
442 
443   unsigned Register =
444       AArch64MCRegisterClasses[AArch64::FPR64RegClassID].getRegister(RegNo);
445   Inst.addOperand(MCOperand::createReg(Register));
446   return Success;
447 }
448 
449 static DecodeStatus DecodeFPR32RegisterClass(MCInst &Inst, unsigned RegNo,
450                                              uint64_t Addr,
451                                              const MCDisassembler *Decoder) {
452   if (RegNo > 31)
453     return Fail;
454 
455   unsigned Register =
456       AArch64MCRegisterClasses[AArch64::FPR32RegClassID].getRegister(RegNo);
457   Inst.addOperand(MCOperand::createReg(Register));
458   return Success;
459 }
460 
461 static DecodeStatus DecodeFPR16RegisterClass(MCInst &Inst, unsigned RegNo,
462                                              uint64_t Addr,
463                                              const MCDisassembler *Decoder) {
464   if (RegNo > 31)
465     return Fail;
466 
467   unsigned Register =
468       AArch64MCRegisterClasses[AArch64::FPR16RegClassID].getRegister(RegNo);
469   Inst.addOperand(MCOperand::createReg(Register));
470   return Success;
471 }
472 
473 static DecodeStatus DecodeFPR8RegisterClass(MCInst &Inst, unsigned RegNo,
474                                             uint64_t Addr,
475                                             const MCDisassembler *Decoder) {
476   if (RegNo > 31)
477     return Fail;
478 
479   unsigned Register =
480       AArch64MCRegisterClasses[AArch64::FPR8RegClassID].getRegister(RegNo);
481   Inst.addOperand(MCOperand::createReg(Register));
482   return Success;
483 }
484 
485 static DecodeStatus
486 DecodeGPR64commonRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Addr,
487                                const MCDisassembler *Decoder) {
488   if (RegNo > 30)
489     return Fail;
490 
491   unsigned Register =
492       AArch64MCRegisterClasses[AArch64::GPR64commonRegClassID].getRegister(
493           RegNo);
494   Inst.addOperand(MCOperand::createReg(Register));
495   return Success;
496 }
497 
498 static DecodeStatus DecodeGPR64RegisterClass(MCInst &Inst, unsigned RegNo,
499                                              uint64_t Addr,
500                                              const MCDisassembler *Decoder) {
501   if (RegNo > 31)
502     return Fail;
503 
504   unsigned Register =
505       AArch64MCRegisterClasses[AArch64::GPR64RegClassID].getRegister(RegNo);
506   Inst.addOperand(MCOperand::createReg(Register));
507   return Success;
508 }
509 
510 static DecodeStatus
511 DecodeGPR64x8ClassRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Address,
512                                 const MCDisassembler *Decoder) {
513   if (RegNo > 22)
514     return Fail;
515   if (RegNo & 1)
516     return Fail;
517 
518   unsigned Register =
519       AArch64MCRegisterClasses[AArch64::GPR64x8ClassRegClassID].getRegister(
520           RegNo >> 1);
521   Inst.addOperand(MCOperand::createReg(Register));
522   return Success;
523 }
524 
525 static DecodeStatus DecodeGPR64spRegisterClass(MCInst &Inst, unsigned RegNo,
526                                                uint64_t Addr,
527                                                const MCDisassembler *Decoder) {
528   if (RegNo > 31)
529     return Fail;
530   unsigned Register =
531       AArch64MCRegisterClasses[AArch64::GPR64spRegClassID].getRegister(RegNo);
532   Inst.addOperand(MCOperand::createReg(Register));
533   return Success;
534 }
535 
536 static DecodeStatus
537 DecodeMatrixIndexGPR32_8_11RegisterClass(MCInst &Inst, unsigned RegNo,
538                                          uint64_t Addr, const void *Decoder) {
539   if (RegNo > 3)
540     return Fail;
541 
542   unsigned Register =
543       AArch64MCRegisterClasses[AArch64::MatrixIndexGPR32_8_11RegClassID]
544           .getRegister(RegNo);
545   Inst.addOperand(MCOperand::createReg(Register));
546   return Success;
547 }
548 
549 static DecodeStatus
550 DecodeMatrixIndexGPR32_12_15RegisterClass(MCInst &Inst, unsigned RegNo,
551                                           uint64_t Addr,
552                                           const MCDisassembler *Decoder) {
553   if (RegNo > 3)
554     return Fail;
555 
556   unsigned Register =
557       AArch64MCRegisterClasses[AArch64::MatrixIndexGPR32_12_15RegClassID]
558           .getRegister(RegNo);
559   Inst.addOperand(MCOperand::createReg(Register));
560   return Success;
561 }
562 
563 static DecodeStatus DecodeGPR32RegisterClass(MCInst &Inst, unsigned RegNo,
564                                              uint64_t Addr,
565                                              const MCDisassembler *Decoder) {
566   if (RegNo > 31)
567     return Fail;
568 
569   unsigned Register =
570       AArch64MCRegisterClasses[AArch64::GPR32RegClassID].getRegister(RegNo);
571   Inst.addOperand(MCOperand::createReg(Register));
572   return Success;
573 }
574 
575 static DecodeStatus DecodeGPR32spRegisterClass(MCInst &Inst, unsigned RegNo,
576                                                uint64_t Addr,
577                                                const MCDisassembler *Decoder) {
578   if (RegNo > 31)
579     return Fail;
580 
581   unsigned Register =
582       AArch64MCRegisterClasses[AArch64::GPR32spRegClassID].getRegister(RegNo);
583   Inst.addOperand(MCOperand::createReg(Register));
584   return Success;
585 }
586 
587 static DecodeStatus DecodeZPRRegisterClass(MCInst &Inst, unsigned RegNo,
588                                            uint64_t Address,
589                                            const MCDisassembler *Decoder) {
590   if (RegNo > 31)
591     return Fail;
592 
593   unsigned Register =
594       AArch64MCRegisterClasses[AArch64::ZPRRegClassID].getRegister(RegNo);
595   Inst.addOperand(MCOperand::createReg(Register));
596   return Success;
597 }
598 
599 static DecodeStatus DecodeZPR_4bRegisterClass(MCInst &Inst, unsigned RegNo,
600                                               uint64_t Address,
601                                               const MCDisassembler *Decoder) {
602   if (RegNo > 15)
603     return Fail;
604   return DecodeZPRRegisterClass(Inst, RegNo, Address, Decoder);
605 }
606 
607 static DecodeStatus DecodeZPR_3bRegisterClass(MCInst &Inst, unsigned RegNo,
608                                               uint64_t Address,
609                                               const MCDisassembler *Decoder) {
610   if (RegNo > 7)
611     return Fail;
612   return DecodeZPRRegisterClass(Inst, RegNo, Address, Decoder);
613 }
614 
615 static DecodeStatus DecodeZPR2RegisterClass(MCInst &Inst, unsigned RegNo,
616                                             uint64_t Address,
617                                             const MCDisassembler *Decoder) {
618   if (RegNo > 31)
619     return Fail;
620   unsigned Register =
621       AArch64MCRegisterClasses[AArch64::ZPR2RegClassID].getRegister(RegNo);
622   Inst.addOperand(MCOperand::createReg(Register));
623   return Success;
624 }
625 
626 static DecodeStatus DecodeZPR3RegisterClass(MCInst &Inst, unsigned RegNo,
627                                             uint64_t Address,
628                                             const MCDisassembler *Decoder) {
629   if (RegNo > 31)
630     return Fail;
631   unsigned Register =
632       AArch64MCRegisterClasses[AArch64::ZPR3RegClassID].getRegister(RegNo);
633   Inst.addOperand(MCOperand::createReg(Register));
634   return Success;
635 }
636 
637 static DecodeStatus DecodeZPR4RegisterClass(MCInst &Inst, unsigned RegNo,
638                                             uint64_t Address,
639                                             const MCDisassembler *Decoder) {
640   if (RegNo > 31)
641     return Fail;
642   unsigned Register =
643       AArch64MCRegisterClasses[AArch64::ZPR4RegClassID].getRegister(RegNo);
644   Inst.addOperand(MCOperand::createReg(Register));
645   return Success;
646 }
647 
648 static DecodeStatus DecodeZPR2Mul2RegisterClass(MCInst &Inst, unsigned RegNo,
649                                                 uint64_t Address,
650                                                 const void *Decoder) {
651   if (RegNo * 2 > 30)
652     return Fail;
653   unsigned Register =
654       AArch64MCRegisterClasses[AArch64::ZPR2RegClassID].getRegister(RegNo * 2);
655   Inst.addOperand(MCOperand::createReg(Register));
656   return Success;
657 }
658 
659 static DecodeStatus DecodeZPR4Mul4RegisterClass(MCInst &Inst, unsigned RegNo,
660                                                 uint64_t Address,
661                                                 const void *Decoder) {
662   if (RegNo * 4 > 28)
663     return Fail;
664   unsigned Register =
665       AArch64MCRegisterClasses[AArch64::ZPR4RegClassID].getRegister(RegNo * 4);
666   Inst.addOperand(MCOperand::createReg(Register));
667   return Success;
668 }
669 
670 static DecodeStatus DecodeZPR2StridedRegisterClass(MCInst &Inst, unsigned RegNo,
671                                                    uint64_t Address,
672                                                    const void *Decoder) {
673   if (RegNo > 15)
674     return Fail;
675   unsigned Register =
676       AArch64MCRegisterClasses[AArch64::ZPR2StridedRegClassID].getRegister(
677           RegNo);
678   Inst.addOperand(MCOperand::createReg(Register));
679   return Success;
680 }
681 
682 static DecodeStatus DecodeZPR4StridedRegisterClass(MCInst &Inst, unsigned RegNo,
683                                                    uint64_t Address,
684                                                    const void *Decoder) {
685   if (RegNo > 7)
686     return Fail;
687   unsigned Register =
688       AArch64MCRegisterClasses[AArch64::ZPR4StridedRegClassID].getRegister(
689           RegNo);
690   Inst.addOperand(MCOperand::createReg(Register));
691   return Success;
692 }
693 
694 static DecodeStatus
695 DecodeMatrixTileListRegisterClass(MCInst &Inst, unsigned RegMask,
696                                   uint64_t Address,
697                                   const MCDisassembler *Decoder) {
698   if (RegMask > 0xFF)
699     return Fail;
700   Inst.addOperand(MCOperand::createImm(RegMask));
701   return Success;
702 }
703 
704 static const MCPhysReg MatrixZATileDecoderTable[5][16] = {
705     {AArch64::ZAB0},
706     {AArch64::ZAH0, AArch64::ZAH1},
707     {AArch64::ZAS0, AArch64::ZAS1, AArch64::ZAS2, AArch64::ZAS3},
708     {AArch64::ZAD0, AArch64::ZAD1, AArch64::ZAD2, AArch64::ZAD3, AArch64::ZAD4,
709      AArch64::ZAD5, AArch64::ZAD6, AArch64::ZAD7},
710     {AArch64::ZAQ0, AArch64::ZAQ1, AArch64::ZAQ2, AArch64::ZAQ3, AArch64::ZAQ4,
711      AArch64::ZAQ5, AArch64::ZAQ6, AArch64::ZAQ7, AArch64::ZAQ8, AArch64::ZAQ9,
712      AArch64::ZAQ10, AArch64::ZAQ11, AArch64::ZAQ12, AArch64::ZAQ13,
713      AArch64::ZAQ14, AArch64::ZAQ15}};
714 
715 template <unsigned NumBitsForTile>
716 static DecodeStatus DecodeMatrixTile(MCInst &Inst, unsigned RegNo,
717                                      uint64_t Address,
718                                      const MCDisassembler *Decoder) {
719   unsigned LastReg = (1 << NumBitsForTile) - 1;
720   if (RegNo > LastReg)
721     return Fail;
722   Inst.addOperand(
723       MCOperand::createReg(MatrixZATileDecoderTable[NumBitsForTile][RegNo]));
724   return Success;
725 }
726 
727 static DecodeStatus DecodePPRRegisterClass(MCInst &Inst, unsigned RegNo,
728                                            uint64_t Addr,
729                                            const MCDisassembler *Decoder) {
730   if (RegNo > 15)
731     return Fail;
732 
733   unsigned Register =
734       AArch64MCRegisterClasses[AArch64::PPRRegClassID].getRegister(RegNo);
735   Inst.addOperand(MCOperand::createReg(Register));
736   return Success;
737 }
738 
739 static DecodeStatus DecodePPR_3bRegisterClass(MCInst &Inst, unsigned RegNo,
740                                               uint64_t Addr,
741                                               const MCDisassembler *Decoder) {
742   if (RegNo > 7)
743     return Fail;
744 
745   // Just reuse the PPR decode table
746   return DecodePPRRegisterClass(Inst, RegNo, Addr, Decoder);
747 }
748 
749 static DecodeStatus
750 DecodePPR_p8to15RegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Addr,
751                               const MCDisassembler *Decoder) {
752   if (RegNo > 7)
753     return Fail;
754 
755   // Just reuse the PPR decode table
756   return DecodePPRRegisterClass(Inst, RegNo + 8, Addr, Decoder);
757 }
758 
759 static DecodeStatus DecodePPR2RegisterClass(MCInst &Inst, unsigned RegNo,
760                                             uint64_t Address,
761                                             const void *Decoder) {
762   if (RegNo > 15)
763     return Fail;
764 
765   unsigned Register =
766       AArch64MCRegisterClasses[AArch64::PPR2RegClassID].getRegister(RegNo);
767   Inst.addOperand(MCOperand::createReg(Register));
768   return Success;
769 }
770 
771 static DecodeStatus DecodePPR2Mul2RegisterClass(MCInst &Inst, unsigned RegNo,
772                                                 uint64_t Address,
773                                                 const void *Decoder) {
774   if ((RegNo * 2) > 14)
775     return Fail;
776   unsigned Register =
777       AArch64MCRegisterClasses[AArch64::PPR2RegClassID].getRegister(RegNo * 2);
778   Inst.addOperand(MCOperand::createReg(Register));
779   return Success;
780 }
781 
782 static DecodeStatus DecodeQQRegisterClass(MCInst &Inst, unsigned RegNo,
783                                           uint64_t Addr,
784                                           const MCDisassembler *Decoder) {
785   if (RegNo > 31)
786     return Fail;
787   unsigned Register =
788       AArch64MCRegisterClasses[AArch64::QQRegClassID].getRegister(RegNo);
789   Inst.addOperand(MCOperand::createReg(Register));
790   return Success;
791 }
792 
793 static DecodeStatus DecodeQQQRegisterClass(MCInst &Inst, unsigned RegNo,
794                                            uint64_t Addr,
795                                            const MCDisassembler *Decoder) {
796   if (RegNo > 31)
797     return Fail;
798   unsigned Register =
799       AArch64MCRegisterClasses[AArch64::QQQRegClassID].getRegister(RegNo);
800   Inst.addOperand(MCOperand::createReg(Register));
801   return Success;
802 }
803 
804 static DecodeStatus DecodeQQQQRegisterClass(MCInst &Inst, unsigned RegNo,
805                                             uint64_t Addr,
806                                             const MCDisassembler *Decoder) {
807   if (RegNo > 31)
808     return Fail;
809   unsigned Register =
810       AArch64MCRegisterClasses[AArch64::QQQQRegClassID].getRegister(RegNo);
811   Inst.addOperand(MCOperand::createReg(Register));
812   return Success;
813 }
814 
815 static DecodeStatus DecodeDDRegisterClass(MCInst &Inst, unsigned RegNo,
816                                           uint64_t Addr,
817                                           const MCDisassembler *Decoder) {
818   if (RegNo > 31)
819     return Fail;
820   unsigned Register =
821       AArch64MCRegisterClasses[AArch64::DDRegClassID].getRegister(RegNo);
822   Inst.addOperand(MCOperand::createReg(Register));
823   return Success;
824 }
825 
826 static DecodeStatus DecodeDDDRegisterClass(MCInst &Inst, unsigned RegNo,
827                                            uint64_t Addr,
828                                            const MCDisassembler *Decoder) {
829   if (RegNo > 31)
830     return Fail;
831   unsigned Register =
832       AArch64MCRegisterClasses[AArch64::DDDRegClassID].getRegister(RegNo);
833   Inst.addOperand(MCOperand::createReg(Register));
834   return Success;
835 }
836 
837 static DecodeStatus DecodeDDDDRegisterClass(MCInst &Inst, unsigned RegNo,
838                                             uint64_t Addr,
839                                             const MCDisassembler *Decoder) {
840   if (RegNo > 31)
841     return Fail;
842   unsigned Register =
843       AArch64MCRegisterClasses[AArch64::DDDDRegClassID].getRegister(RegNo);
844   Inst.addOperand(MCOperand::createReg(Register));
845   return Success;
846 }
847 
848 static DecodeStatus DecodeFixedPointScaleImm32(MCInst &Inst, unsigned Imm,
849                                                uint64_t Addr,
850                                                const MCDisassembler *Decoder) {
851   // scale{5} is asserted as 1 in tblgen.
852   Imm |= 0x20;
853   Inst.addOperand(MCOperand::createImm(64 - Imm));
854   return Success;
855 }
856 
857 static DecodeStatus DecodeFixedPointScaleImm64(MCInst &Inst, unsigned Imm,
858                                                uint64_t Addr,
859                                                const MCDisassembler *Decoder) {
860   Inst.addOperand(MCOperand::createImm(64 - Imm));
861   return Success;
862 }
863 
864 static DecodeStatus DecodePCRelLabel19(MCInst &Inst, unsigned Imm,
865                                        uint64_t Addr,
866                                        const MCDisassembler *Decoder) {
867   int64_t ImmVal = Imm;
868 
869   // Sign-extend 19-bit immediate.
870   if (ImmVal & (1 << (19 - 1)))
871     ImmVal |= ~((1LL << 19) - 1);
872 
873   if (!Decoder->tryAddingSymbolicOperand(
874           Inst, ImmVal * 4, Addr, Inst.getOpcode() != AArch64::LDRXl, 0, 0, 4))
875     Inst.addOperand(MCOperand::createImm(ImmVal));
876   return Success;
877 }
878 
879 static DecodeStatus DecodeMemExtend(MCInst &Inst, unsigned Imm,
880                                     uint64_t Address,
881                                     const MCDisassembler *Decoder) {
882   Inst.addOperand(MCOperand::createImm((Imm  >> 1) & 1));
883   Inst.addOperand(MCOperand::createImm(Imm & 1));
884   return Success;
885 }
886 
887 static DecodeStatus DecodeMRSSystemRegister(MCInst &Inst, unsigned Imm,
888                                             uint64_t Address,
889                                             const MCDisassembler *Decoder) {
890   Inst.addOperand(MCOperand::createImm(Imm));
891 
892   // Every system register in the encoding space is valid with the syntax
893   // S<op0>_<op1>_<Cn>_<Cm>_<op2>, so decoding system registers always succeeds.
894   return Success;
895 }
896 
897 static DecodeStatus DecodeMSRSystemRegister(MCInst &Inst, unsigned Imm,
898                                             uint64_t Address,
899                                             const MCDisassembler *Decoder) {
900   Inst.addOperand(MCOperand::createImm(Imm));
901 
902   return Success;
903 }
904 
905 static DecodeStatus DecodeFMOVLaneInstruction(MCInst &Inst, unsigned Insn,
906                                               uint64_t Address,
907                                               const MCDisassembler *Decoder) {
908   // This decoder exists to add the dummy Lane operand to the MCInst, which must
909   // be 1 in assembly but has no other real manifestation.
910   unsigned Rd = fieldFromInstruction(Insn, 0, 5);
911   unsigned Rn = fieldFromInstruction(Insn, 5, 5);
912   unsigned IsToVec = fieldFromInstruction(Insn, 16, 1);
913 
914   if (IsToVec) {
915     DecodeFPR128RegisterClass(Inst, Rd, Address, Decoder);
916     DecodeGPR64RegisterClass(Inst, Rn, Address, Decoder);
917   } else {
918     DecodeGPR64RegisterClass(Inst, Rd, Address, Decoder);
919     DecodeFPR128RegisterClass(Inst, Rn, Address, Decoder);
920   }
921 
922   // Add the lane
923   Inst.addOperand(MCOperand::createImm(1));
924 
925   return Success;
926 }
927 
928 static DecodeStatus DecodeVecShiftRImm(MCInst &Inst, unsigned Imm,
929                                        unsigned Add) {
930   Inst.addOperand(MCOperand::createImm(Add - Imm));
931   return Success;
932 }
933 
934 static DecodeStatus DecodeVecShiftLImm(MCInst &Inst, unsigned Imm,
935                                        unsigned Add) {
936   Inst.addOperand(MCOperand::createImm((Imm + Add) & (Add - 1)));
937   return Success;
938 }
939 
940 static DecodeStatus DecodeVecShiftR64Imm(MCInst &Inst, unsigned Imm,
941                                          uint64_t Addr,
942                                          const MCDisassembler *Decoder) {
943   return DecodeVecShiftRImm(Inst, Imm, 64);
944 }
945 
946 static DecodeStatus DecodeVecShiftR64ImmNarrow(MCInst &Inst, unsigned Imm,
947                                                uint64_t Addr,
948                                                const MCDisassembler *Decoder) {
949   return DecodeVecShiftRImm(Inst, Imm | 0x20, 64);
950 }
951 
952 static DecodeStatus DecodeVecShiftR32Imm(MCInst &Inst, unsigned Imm,
953                                          uint64_t Addr,
954                                          const MCDisassembler *Decoder) {
955   return DecodeVecShiftRImm(Inst, Imm, 32);
956 }
957 
958 static DecodeStatus DecodeVecShiftR32ImmNarrow(MCInst &Inst, unsigned Imm,
959                                                uint64_t Addr,
960                                                const MCDisassembler *Decoder) {
961   return DecodeVecShiftRImm(Inst, Imm | 0x10, 32);
962 }
963 
964 static DecodeStatus DecodeVecShiftR16Imm(MCInst &Inst, unsigned Imm,
965                                          uint64_t Addr,
966                                          const MCDisassembler *Decoder) {
967   return DecodeVecShiftRImm(Inst, Imm, 16);
968 }
969 
970 static DecodeStatus DecodeVecShiftR16ImmNarrow(MCInst &Inst, unsigned Imm,
971                                                uint64_t Addr,
972                                                const MCDisassembler *Decoder) {
973   return DecodeVecShiftRImm(Inst, Imm | 0x8, 16);
974 }
975 
976 static DecodeStatus DecodeVecShiftR8Imm(MCInst &Inst, unsigned Imm,
977                                         uint64_t Addr,
978                                         const MCDisassembler *Decoder) {
979   return DecodeVecShiftRImm(Inst, Imm, 8);
980 }
981 
982 static DecodeStatus DecodeVecShiftL64Imm(MCInst &Inst, unsigned Imm,
983                                          uint64_t Addr,
984                                          const MCDisassembler *Decoder) {
985   return DecodeVecShiftLImm(Inst, Imm, 64);
986 }
987 
988 static DecodeStatus DecodeVecShiftL32Imm(MCInst &Inst, unsigned Imm,
989                                          uint64_t Addr,
990                                          const MCDisassembler *Decoder) {
991   return DecodeVecShiftLImm(Inst, Imm, 32);
992 }
993 
994 static DecodeStatus DecodeVecShiftL16Imm(MCInst &Inst, unsigned Imm,
995                                          uint64_t Addr,
996                                          const MCDisassembler *Decoder) {
997   return DecodeVecShiftLImm(Inst, Imm, 16);
998 }
999 
1000 static DecodeStatus DecodeVecShiftL8Imm(MCInst &Inst, unsigned Imm,
1001                                         uint64_t Addr,
1002                                         const MCDisassembler *Decoder) {
1003   return DecodeVecShiftLImm(Inst, Imm, 8);
1004 }
1005 
1006 static DecodeStatus
1007 DecodeThreeAddrSRegInstruction(MCInst &Inst, uint32_t insn, uint64_t Addr,
1008                                const MCDisassembler *Decoder) {
1009   unsigned Rd = fieldFromInstruction(insn, 0, 5);
1010   unsigned Rn = fieldFromInstruction(insn, 5, 5);
1011   unsigned Rm = fieldFromInstruction(insn, 16, 5);
1012   unsigned shiftHi = fieldFromInstruction(insn, 22, 2);
1013   unsigned shiftLo = fieldFromInstruction(insn, 10, 6);
1014   unsigned shift = (shiftHi << 6) | shiftLo;
1015   switch (Inst.getOpcode()) {
1016   default:
1017     return Fail;
1018   case AArch64::ADDWrs:
1019   case AArch64::ADDSWrs:
1020   case AArch64::SUBWrs:
1021   case AArch64::SUBSWrs:
1022     // if shift == '11' then ReservedValue()
1023     if (shiftHi == 0x3)
1024       return Fail;
1025     [[fallthrough]];
1026   case AArch64::ANDWrs:
1027   case AArch64::ANDSWrs:
1028   case AArch64::BICWrs:
1029   case AArch64::BICSWrs:
1030   case AArch64::ORRWrs:
1031   case AArch64::ORNWrs:
1032   case AArch64::EORWrs:
1033   case AArch64::EONWrs: {
1034     // if sf == '0' and imm6<5> == '1' then ReservedValue()
1035     if (shiftLo >> 5 == 1)
1036       return Fail;
1037     DecodeGPR32RegisterClass(Inst, Rd, Addr, Decoder);
1038     DecodeGPR32RegisterClass(Inst, Rn, Addr, Decoder);
1039     DecodeGPR32RegisterClass(Inst, Rm, Addr, Decoder);
1040     break;
1041   }
1042   case AArch64::ADDXrs:
1043   case AArch64::ADDSXrs:
1044   case AArch64::SUBXrs:
1045   case AArch64::SUBSXrs:
1046     // if shift == '11' then ReservedValue()
1047     if (shiftHi == 0x3)
1048       return Fail;
1049     [[fallthrough]];
1050   case AArch64::ANDXrs:
1051   case AArch64::ANDSXrs:
1052   case AArch64::BICXrs:
1053   case AArch64::BICSXrs:
1054   case AArch64::ORRXrs:
1055   case AArch64::ORNXrs:
1056   case AArch64::EORXrs:
1057   case AArch64::EONXrs:
1058     DecodeGPR64RegisterClass(Inst, Rd, Addr, Decoder);
1059     DecodeGPR64RegisterClass(Inst, Rn, Addr, Decoder);
1060     DecodeGPR64RegisterClass(Inst, Rm, Addr, Decoder);
1061     break;
1062   }
1063 
1064   Inst.addOperand(MCOperand::createImm(shift));
1065   return Success;
1066 }
1067 
1068 static DecodeStatus DecodeMoveImmInstruction(MCInst &Inst, uint32_t insn,
1069                                              uint64_t Addr,
1070                                              const MCDisassembler *Decoder) {
1071   unsigned Rd = fieldFromInstruction(insn, 0, 5);
1072   unsigned imm = fieldFromInstruction(insn, 5, 16);
1073   unsigned shift = fieldFromInstruction(insn, 21, 2);
1074   shift <<= 4;
1075   switch (Inst.getOpcode()) {
1076   default:
1077     return Fail;
1078   case AArch64::MOVZWi:
1079   case AArch64::MOVNWi:
1080   case AArch64::MOVKWi:
1081     if (shift & (1U << 5))
1082       return Fail;
1083     DecodeGPR32RegisterClass(Inst, Rd, Addr, Decoder);
1084     break;
1085   case AArch64::MOVZXi:
1086   case AArch64::MOVNXi:
1087   case AArch64::MOVKXi:
1088     DecodeGPR64RegisterClass(Inst, Rd, Addr, Decoder);
1089     break;
1090   }
1091 
1092   if (Inst.getOpcode() == AArch64::MOVKWi ||
1093       Inst.getOpcode() == AArch64::MOVKXi)
1094     Inst.addOperand(Inst.getOperand(0));
1095 
1096   Inst.addOperand(MCOperand::createImm(imm));
1097   Inst.addOperand(MCOperand::createImm(shift));
1098   return Success;
1099 }
1100 
1101 static DecodeStatus
1102 DecodeUnsignedLdStInstruction(MCInst &Inst, uint32_t insn, uint64_t Addr,
1103                               const MCDisassembler *Decoder) {
1104   unsigned Rt = fieldFromInstruction(insn, 0, 5);
1105   unsigned Rn = fieldFromInstruction(insn, 5, 5);
1106   unsigned offset = fieldFromInstruction(insn, 10, 12);
1107 
1108   switch (Inst.getOpcode()) {
1109   default:
1110     return Fail;
1111   case AArch64::PRFMui:
1112     // Rt is an immediate in prefetch.
1113     Inst.addOperand(MCOperand::createImm(Rt));
1114     break;
1115   case AArch64::STRBBui:
1116   case AArch64::LDRBBui:
1117   case AArch64::LDRSBWui:
1118   case AArch64::STRHHui:
1119   case AArch64::LDRHHui:
1120   case AArch64::LDRSHWui:
1121   case AArch64::STRWui:
1122   case AArch64::LDRWui:
1123     DecodeGPR32RegisterClass(Inst, Rt, Addr, Decoder);
1124     break;
1125   case AArch64::LDRSBXui:
1126   case AArch64::LDRSHXui:
1127   case AArch64::LDRSWui:
1128   case AArch64::STRXui:
1129   case AArch64::LDRXui:
1130     DecodeGPR64RegisterClass(Inst, Rt, Addr, Decoder);
1131     break;
1132   case AArch64::LDRQui:
1133   case AArch64::STRQui:
1134     DecodeFPR128RegisterClass(Inst, Rt, Addr, Decoder);
1135     break;
1136   case AArch64::LDRDui:
1137   case AArch64::STRDui:
1138     DecodeFPR64RegisterClass(Inst, Rt, Addr, Decoder);
1139     break;
1140   case AArch64::LDRSui:
1141   case AArch64::STRSui:
1142     DecodeFPR32RegisterClass(Inst, Rt, Addr, Decoder);
1143     break;
1144   case AArch64::LDRHui:
1145   case AArch64::STRHui:
1146     DecodeFPR16RegisterClass(Inst, Rt, Addr, Decoder);
1147     break;
1148   case AArch64::LDRBui:
1149   case AArch64::STRBui:
1150     DecodeFPR8RegisterClass(Inst, Rt, Addr, Decoder);
1151     break;
1152   }
1153 
1154   DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);
1155   if (!Decoder->tryAddingSymbolicOperand(Inst, offset, Addr, Fail, 0, 0, 4))
1156     Inst.addOperand(MCOperand::createImm(offset));
1157   return Success;
1158 }
1159 
1160 static DecodeStatus DecodeSignedLdStInstruction(MCInst &Inst, uint32_t insn,
1161                                                 uint64_t Addr,
1162                                                 const MCDisassembler *Decoder) {
1163   unsigned Rt = fieldFromInstruction(insn, 0, 5);
1164   unsigned Rn = fieldFromInstruction(insn, 5, 5);
1165   int64_t offset = fieldFromInstruction(insn, 12, 9);
1166 
1167   // offset is a 9-bit signed immediate, so sign extend it to
1168   // fill the unsigned.
1169   if (offset & (1 << (9 - 1)))
1170     offset |= ~((1LL << 9) - 1);
1171 
1172   // First operand is always the writeback to the address register, if needed.
1173   switch (Inst.getOpcode()) {
1174   default:
1175     break;
1176   case AArch64::LDRSBWpre:
1177   case AArch64::LDRSHWpre:
1178   case AArch64::STRBBpre:
1179   case AArch64::LDRBBpre:
1180   case AArch64::STRHHpre:
1181   case AArch64::LDRHHpre:
1182   case AArch64::STRWpre:
1183   case AArch64::LDRWpre:
1184   case AArch64::LDRSBWpost:
1185   case AArch64::LDRSHWpost:
1186   case AArch64::STRBBpost:
1187   case AArch64::LDRBBpost:
1188   case AArch64::STRHHpost:
1189   case AArch64::LDRHHpost:
1190   case AArch64::STRWpost:
1191   case AArch64::LDRWpost:
1192   case AArch64::LDRSBXpre:
1193   case AArch64::LDRSHXpre:
1194   case AArch64::STRXpre:
1195   case AArch64::LDRSWpre:
1196   case AArch64::LDRXpre:
1197   case AArch64::LDRSBXpost:
1198   case AArch64::LDRSHXpost:
1199   case AArch64::STRXpost:
1200   case AArch64::LDRSWpost:
1201   case AArch64::LDRXpost:
1202   case AArch64::LDRQpre:
1203   case AArch64::STRQpre:
1204   case AArch64::LDRQpost:
1205   case AArch64::STRQpost:
1206   case AArch64::LDRDpre:
1207   case AArch64::STRDpre:
1208   case AArch64::LDRDpost:
1209   case AArch64::STRDpost:
1210   case AArch64::LDRSpre:
1211   case AArch64::STRSpre:
1212   case AArch64::LDRSpost:
1213   case AArch64::STRSpost:
1214   case AArch64::LDRHpre:
1215   case AArch64::STRHpre:
1216   case AArch64::LDRHpost:
1217   case AArch64::STRHpost:
1218   case AArch64::LDRBpre:
1219   case AArch64::STRBpre:
1220   case AArch64::LDRBpost:
1221   case AArch64::STRBpost:
1222     DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);
1223     break;
1224   }
1225 
1226   switch (Inst.getOpcode()) {
1227   default:
1228     return Fail;
1229   case AArch64::PRFUMi:
1230     // Rt is an immediate in prefetch.
1231     Inst.addOperand(MCOperand::createImm(Rt));
1232     break;
1233   case AArch64::STURBBi:
1234   case AArch64::LDURBBi:
1235   case AArch64::LDURSBWi:
1236   case AArch64::STURHHi:
1237   case AArch64::LDURHHi:
1238   case AArch64::LDURSHWi:
1239   case AArch64::STURWi:
1240   case AArch64::LDURWi:
1241   case AArch64::LDTRSBWi:
1242   case AArch64::LDTRSHWi:
1243   case AArch64::STTRWi:
1244   case AArch64::LDTRWi:
1245   case AArch64::STTRHi:
1246   case AArch64::LDTRHi:
1247   case AArch64::LDTRBi:
1248   case AArch64::STTRBi:
1249   case AArch64::LDRSBWpre:
1250   case AArch64::LDRSHWpre:
1251   case AArch64::STRBBpre:
1252   case AArch64::LDRBBpre:
1253   case AArch64::STRHHpre:
1254   case AArch64::LDRHHpre:
1255   case AArch64::STRWpre:
1256   case AArch64::LDRWpre:
1257   case AArch64::LDRSBWpost:
1258   case AArch64::LDRSHWpost:
1259   case AArch64::STRBBpost:
1260   case AArch64::LDRBBpost:
1261   case AArch64::STRHHpost:
1262   case AArch64::LDRHHpost:
1263   case AArch64::STRWpost:
1264   case AArch64::LDRWpost:
1265   case AArch64::STLURBi:
1266   case AArch64::STLURHi:
1267   case AArch64::STLURWi:
1268   case AArch64::LDAPURBi:
1269   case AArch64::LDAPURSBWi:
1270   case AArch64::LDAPURHi:
1271   case AArch64::LDAPURSHWi:
1272   case AArch64::LDAPURi:
1273     DecodeGPR32RegisterClass(Inst, Rt, Addr, Decoder);
1274     break;
1275   case AArch64::LDURSBXi:
1276   case AArch64::LDURSHXi:
1277   case AArch64::LDURSWi:
1278   case AArch64::STURXi:
1279   case AArch64::LDURXi:
1280   case AArch64::LDTRSBXi:
1281   case AArch64::LDTRSHXi:
1282   case AArch64::LDTRSWi:
1283   case AArch64::STTRXi:
1284   case AArch64::LDTRXi:
1285   case AArch64::LDRSBXpre:
1286   case AArch64::LDRSHXpre:
1287   case AArch64::STRXpre:
1288   case AArch64::LDRSWpre:
1289   case AArch64::LDRXpre:
1290   case AArch64::LDRSBXpost:
1291   case AArch64::LDRSHXpost:
1292   case AArch64::STRXpost:
1293   case AArch64::LDRSWpost:
1294   case AArch64::LDRXpost:
1295   case AArch64::LDAPURSWi:
1296   case AArch64::LDAPURSHXi:
1297   case AArch64::LDAPURSBXi:
1298   case AArch64::STLURXi:
1299   case AArch64::LDAPURXi:
1300     DecodeGPR64RegisterClass(Inst, Rt, Addr, Decoder);
1301     break;
1302   case AArch64::LDURQi:
1303   case AArch64::STURQi:
1304   case AArch64::LDRQpre:
1305   case AArch64::STRQpre:
1306   case AArch64::LDRQpost:
1307   case AArch64::STRQpost:
1308     DecodeFPR128RegisterClass(Inst, Rt, Addr, Decoder);
1309     break;
1310   case AArch64::LDURDi:
1311   case AArch64::STURDi:
1312   case AArch64::LDRDpre:
1313   case AArch64::STRDpre:
1314   case AArch64::LDRDpost:
1315   case AArch64::STRDpost:
1316     DecodeFPR64RegisterClass(Inst, Rt, Addr, Decoder);
1317     break;
1318   case AArch64::LDURSi:
1319   case AArch64::STURSi:
1320   case AArch64::LDRSpre:
1321   case AArch64::STRSpre:
1322   case AArch64::LDRSpost:
1323   case AArch64::STRSpost:
1324     DecodeFPR32RegisterClass(Inst, Rt, Addr, Decoder);
1325     break;
1326   case AArch64::LDURHi:
1327   case AArch64::STURHi:
1328   case AArch64::LDRHpre:
1329   case AArch64::STRHpre:
1330   case AArch64::LDRHpost:
1331   case AArch64::STRHpost:
1332     DecodeFPR16RegisterClass(Inst, Rt, Addr, Decoder);
1333     break;
1334   case AArch64::LDURBi:
1335   case AArch64::STURBi:
1336   case AArch64::LDRBpre:
1337   case AArch64::STRBpre:
1338   case AArch64::LDRBpost:
1339   case AArch64::STRBpost:
1340     DecodeFPR8RegisterClass(Inst, Rt, Addr, Decoder);
1341     break;
1342   }
1343 
1344   DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);
1345   Inst.addOperand(MCOperand::createImm(offset));
1346 
1347   bool IsLoad = fieldFromInstruction(insn, 22, 1);
1348   bool IsIndexed = fieldFromInstruction(insn, 10, 2) != 0;
1349   bool IsFP = fieldFromInstruction(insn, 26, 1);
1350 
1351   // Cannot write back to a transfer register (but xzr != sp).
1352   if (IsLoad && IsIndexed && !IsFP && Rn != 31 && Rt == Rn)
1353     return SoftFail;
1354 
1355   return Success;
1356 }
1357 
1358 static DecodeStatus
1359 DecodeExclusiveLdStInstruction(MCInst &Inst, uint32_t insn, uint64_t Addr,
1360                                const MCDisassembler *Decoder) {
1361   unsigned Rt = fieldFromInstruction(insn, 0, 5);
1362   unsigned Rn = fieldFromInstruction(insn, 5, 5);
1363   unsigned Rt2 = fieldFromInstruction(insn, 10, 5);
1364   unsigned Rs = fieldFromInstruction(insn, 16, 5);
1365 
1366   unsigned Opcode = Inst.getOpcode();
1367   switch (Opcode) {
1368   default:
1369     return Fail;
1370   case AArch64::STLXRW:
1371   case AArch64::STLXRB:
1372   case AArch64::STLXRH:
1373   case AArch64::STXRW:
1374   case AArch64::STXRB:
1375   case AArch64::STXRH:
1376     DecodeGPR32RegisterClass(Inst, Rs, Addr, Decoder);
1377     [[fallthrough]];
1378   case AArch64::LDARW:
1379   case AArch64::LDARB:
1380   case AArch64::LDARH:
1381   case AArch64::LDAXRW:
1382   case AArch64::LDAXRB:
1383   case AArch64::LDAXRH:
1384   case AArch64::LDXRW:
1385   case AArch64::LDXRB:
1386   case AArch64::LDXRH:
1387   case AArch64::STLRW:
1388   case AArch64::STLRB:
1389   case AArch64::STLRH:
1390   case AArch64::STLLRW:
1391   case AArch64::STLLRB:
1392   case AArch64::STLLRH:
1393   case AArch64::LDLARW:
1394   case AArch64::LDLARB:
1395   case AArch64::LDLARH:
1396     DecodeGPR32RegisterClass(Inst, Rt, Addr, Decoder);
1397     break;
1398   case AArch64::STLXRX:
1399   case AArch64::STXRX:
1400     DecodeGPR32RegisterClass(Inst, Rs, Addr, Decoder);
1401     [[fallthrough]];
1402   case AArch64::LDARX:
1403   case AArch64::LDAXRX:
1404   case AArch64::LDXRX:
1405   case AArch64::STLRX:
1406   case AArch64::LDLARX:
1407   case AArch64::STLLRX:
1408     DecodeGPR64RegisterClass(Inst, Rt, Addr, Decoder);
1409     break;
1410   case AArch64::STLXPW:
1411   case AArch64::STXPW:
1412     DecodeGPR32RegisterClass(Inst, Rs, Addr, Decoder);
1413     [[fallthrough]];
1414   case AArch64::LDAXPW:
1415   case AArch64::LDXPW:
1416     DecodeGPR32RegisterClass(Inst, Rt, Addr, Decoder);
1417     DecodeGPR32RegisterClass(Inst, Rt2, Addr, Decoder);
1418     break;
1419   case AArch64::STLXPX:
1420   case AArch64::STXPX:
1421     DecodeGPR32RegisterClass(Inst, Rs, Addr, Decoder);
1422     [[fallthrough]];
1423   case AArch64::LDAXPX:
1424   case AArch64::LDXPX:
1425     DecodeGPR64RegisterClass(Inst, Rt, Addr, Decoder);
1426     DecodeGPR64RegisterClass(Inst, Rt2, Addr, Decoder);
1427     break;
1428   }
1429 
1430   DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);
1431 
1432   // You shouldn't load to the same register twice in an instruction...
1433   if ((Opcode == AArch64::LDAXPW || Opcode == AArch64::LDXPW ||
1434        Opcode == AArch64::LDAXPX || Opcode == AArch64::LDXPX) &&
1435       Rt == Rt2)
1436     return SoftFail;
1437 
1438   return Success;
1439 }
1440 
1441 static DecodeStatus DecodePairLdStInstruction(MCInst &Inst, uint32_t insn,
1442                                               uint64_t Addr,
1443                                               const MCDisassembler *Decoder) {
1444   unsigned Rt = fieldFromInstruction(insn, 0, 5);
1445   unsigned Rn = fieldFromInstruction(insn, 5, 5);
1446   unsigned Rt2 = fieldFromInstruction(insn, 10, 5);
1447   int64_t offset = fieldFromInstruction(insn, 15, 7);
1448   bool IsLoad = fieldFromInstruction(insn, 22, 1);
1449 
1450   // offset is a 7-bit signed immediate, so sign extend it to
1451   // fill the unsigned.
1452   if (offset & (1 << (7 - 1)))
1453     offset |= ~((1LL << 7) - 1);
1454 
1455   unsigned Opcode = Inst.getOpcode();
1456   bool NeedsDisjointWritebackTransfer = false;
1457 
1458   // First operand is always writeback of base register.
1459   switch (Opcode) {
1460   default:
1461     break;
1462   case AArch64::LDPXpost:
1463   case AArch64::STPXpost:
1464   case AArch64::LDPSWpost:
1465   case AArch64::LDPXpre:
1466   case AArch64::STPXpre:
1467   case AArch64::LDPSWpre:
1468   case AArch64::LDPWpost:
1469   case AArch64::STPWpost:
1470   case AArch64::LDPWpre:
1471   case AArch64::STPWpre:
1472   case AArch64::LDPQpost:
1473   case AArch64::STPQpost:
1474   case AArch64::LDPQpre:
1475   case AArch64::STPQpre:
1476   case AArch64::LDPDpost:
1477   case AArch64::STPDpost:
1478   case AArch64::LDPDpre:
1479   case AArch64::STPDpre:
1480   case AArch64::LDPSpost:
1481   case AArch64::STPSpost:
1482   case AArch64::LDPSpre:
1483   case AArch64::STPSpre:
1484   case AArch64::STGPpre:
1485   case AArch64::STGPpost:
1486     DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);
1487     break;
1488   }
1489 
1490   switch (Opcode) {
1491   default:
1492     return Fail;
1493   case AArch64::LDPXpost:
1494   case AArch64::STPXpost:
1495   case AArch64::LDPSWpost:
1496   case AArch64::LDPXpre:
1497   case AArch64::STPXpre:
1498   case AArch64::LDPSWpre:
1499   case AArch64::STGPpre:
1500   case AArch64::STGPpost:
1501     NeedsDisjointWritebackTransfer = true;
1502     [[fallthrough]];
1503   case AArch64::LDNPXi:
1504   case AArch64::STNPXi:
1505   case AArch64::LDPXi:
1506   case AArch64::STPXi:
1507   case AArch64::LDPSWi:
1508   case AArch64::STGPi:
1509     DecodeGPR64RegisterClass(Inst, Rt, Addr, Decoder);
1510     DecodeGPR64RegisterClass(Inst, Rt2, Addr, Decoder);
1511     break;
1512   case AArch64::LDPWpost:
1513   case AArch64::STPWpost:
1514   case AArch64::LDPWpre:
1515   case AArch64::STPWpre:
1516     NeedsDisjointWritebackTransfer = true;
1517     [[fallthrough]];
1518   case AArch64::LDNPWi:
1519   case AArch64::STNPWi:
1520   case AArch64::LDPWi:
1521   case AArch64::STPWi:
1522     DecodeGPR32RegisterClass(Inst, Rt, Addr, Decoder);
1523     DecodeGPR32RegisterClass(Inst, Rt2, Addr, Decoder);
1524     break;
1525   case AArch64::LDNPQi:
1526   case AArch64::STNPQi:
1527   case AArch64::LDPQpost:
1528   case AArch64::STPQpost:
1529   case AArch64::LDPQi:
1530   case AArch64::STPQi:
1531   case AArch64::LDPQpre:
1532   case AArch64::STPQpre:
1533     DecodeFPR128RegisterClass(Inst, Rt, Addr, Decoder);
1534     DecodeFPR128RegisterClass(Inst, Rt2, Addr, Decoder);
1535     break;
1536   case AArch64::LDNPDi:
1537   case AArch64::STNPDi:
1538   case AArch64::LDPDpost:
1539   case AArch64::STPDpost:
1540   case AArch64::LDPDi:
1541   case AArch64::STPDi:
1542   case AArch64::LDPDpre:
1543   case AArch64::STPDpre:
1544     DecodeFPR64RegisterClass(Inst, Rt, Addr, Decoder);
1545     DecodeFPR64RegisterClass(Inst, Rt2, Addr, Decoder);
1546     break;
1547   case AArch64::LDNPSi:
1548   case AArch64::STNPSi:
1549   case AArch64::LDPSpost:
1550   case AArch64::STPSpost:
1551   case AArch64::LDPSi:
1552   case AArch64::STPSi:
1553   case AArch64::LDPSpre:
1554   case AArch64::STPSpre:
1555     DecodeFPR32RegisterClass(Inst, Rt, Addr, Decoder);
1556     DecodeFPR32RegisterClass(Inst, Rt2, Addr, Decoder);
1557     break;
1558   }
1559 
1560   DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);
1561   Inst.addOperand(MCOperand::createImm(offset));
1562 
1563   // You shouldn't load to the same register twice in an instruction...
1564   if (IsLoad && Rt == Rt2)
1565     return SoftFail;
1566 
1567   // ... or do any operation that writes-back to a transfer register. But note
1568   // that "stp xzr, xzr, [sp], #4" is fine because xzr and sp are different.
1569   if (NeedsDisjointWritebackTransfer && Rn != 31 && (Rt == Rn || Rt2 == Rn))
1570     return SoftFail;
1571 
1572   return Success;
1573 }
1574 
1575 static DecodeStatus DecodeAuthLoadInstruction(MCInst &Inst, uint32_t insn,
1576                                               uint64_t Addr,
1577                                               const MCDisassembler *Decoder) {
1578   unsigned Rt = fieldFromInstruction(insn, 0, 5);
1579   unsigned Rn = fieldFromInstruction(insn, 5, 5);
1580   uint64_t offset = fieldFromInstruction(insn, 22, 1) << 9 |
1581                     fieldFromInstruction(insn, 12, 9);
1582   unsigned writeback = fieldFromInstruction(insn, 11, 1);
1583 
1584   switch (Inst.getOpcode()) {
1585   default:
1586     return Fail;
1587   case AArch64::LDRAAwriteback:
1588   case AArch64::LDRABwriteback:
1589     DecodeGPR64spRegisterClass(Inst, Rn /* writeback register */, Addr,
1590                                Decoder);
1591     break;
1592   case AArch64::LDRAAindexed:
1593   case AArch64::LDRABindexed:
1594     break;
1595   }
1596 
1597   DecodeGPR64RegisterClass(Inst, Rt, Addr, Decoder);
1598   DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);
1599   DecodeSImm<10>(Inst, offset, Addr, Decoder);
1600 
1601   if (writeback && Rt == Rn && Rn != 31) {
1602     return SoftFail;
1603   }
1604 
1605   return Success;
1606 }
1607 
1608 static DecodeStatus DecodeAddSubERegInstruction(MCInst &Inst, uint32_t insn,
1609                                                 uint64_t Addr,
1610                                                 const MCDisassembler *Decoder) {
1611   unsigned Rd = fieldFromInstruction(insn, 0, 5);
1612   unsigned Rn = fieldFromInstruction(insn, 5, 5);
1613   unsigned Rm = fieldFromInstruction(insn, 16, 5);
1614   unsigned extend = fieldFromInstruction(insn, 10, 6);
1615 
1616   unsigned shift = extend & 0x7;
1617   if (shift > 4)
1618     return Fail;
1619 
1620   switch (Inst.getOpcode()) {
1621   default:
1622     return Fail;
1623   case AArch64::ADDWrx:
1624   case AArch64::SUBWrx:
1625     DecodeGPR32spRegisterClass(Inst, Rd, Addr, Decoder);
1626     DecodeGPR32spRegisterClass(Inst, Rn, Addr, Decoder);
1627     DecodeGPR32RegisterClass(Inst, Rm, Addr, Decoder);
1628     break;
1629   case AArch64::ADDSWrx:
1630   case AArch64::SUBSWrx:
1631     DecodeGPR32RegisterClass(Inst, Rd, Addr, Decoder);
1632     DecodeGPR32spRegisterClass(Inst, Rn, Addr, Decoder);
1633     DecodeGPR32RegisterClass(Inst, Rm, Addr, Decoder);
1634     break;
1635   case AArch64::ADDXrx:
1636   case AArch64::SUBXrx:
1637     DecodeGPR64spRegisterClass(Inst, Rd, Addr, Decoder);
1638     DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);
1639     DecodeGPR32RegisterClass(Inst, Rm, Addr, Decoder);
1640     break;
1641   case AArch64::ADDSXrx:
1642   case AArch64::SUBSXrx:
1643     DecodeGPR64RegisterClass(Inst, Rd, Addr, Decoder);
1644     DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);
1645     DecodeGPR32RegisterClass(Inst, Rm, Addr, Decoder);
1646     break;
1647   case AArch64::ADDXrx64:
1648   case AArch64::SUBXrx64:
1649     DecodeGPR64spRegisterClass(Inst, Rd, Addr, Decoder);
1650     DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);
1651     DecodeGPR64RegisterClass(Inst, Rm, Addr, Decoder);
1652     break;
1653   case AArch64::SUBSXrx64:
1654   case AArch64::ADDSXrx64:
1655     DecodeGPR64RegisterClass(Inst, Rd, Addr, Decoder);
1656     DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);
1657     DecodeGPR64RegisterClass(Inst, Rm, Addr, Decoder);
1658     break;
1659   }
1660 
1661   Inst.addOperand(MCOperand::createImm(extend));
1662   return Success;
1663 }
1664 
1665 static DecodeStatus DecodeLogicalImmInstruction(MCInst &Inst, uint32_t insn,
1666                                                 uint64_t Addr,
1667                                                 const MCDisassembler *Decoder) {
1668   unsigned Rd = fieldFromInstruction(insn, 0, 5);
1669   unsigned Rn = fieldFromInstruction(insn, 5, 5);
1670   unsigned Datasize = fieldFromInstruction(insn, 31, 1);
1671   unsigned imm;
1672 
1673   if (Datasize) {
1674     if (Inst.getOpcode() == AArch64::ANDSXri)
1675       DecodeGPR64RegisterClass(Inst, Rd, Addr, Decoder);
1676     else
1677       DecodeGPR64spRegisterClass(Inst, Rd, Addr, Decoder);
1678     DecodeGPR64RegisterClass(Inst, Rn, Addr, Decoder);
1679     imm = fieldFromInstruction(insn, 10, 13);
1680     if (!AArch64_AM::isValidDecodeLogicalImmediate(imm, 64))
1681       return Fail;
1682   } else {
1683     if (Inst.getOpcode() == AArch64::ANDSWri)
1684       DecodeGPR32RegisterClass(Inst, Rd, Addr, Decoder);
1685     else
1686       DecodeGPR32spRegisterClass(Inst, Rd, Addr, Decoder);
1687     DecodeGPR32RegisterClass(Inst, Rn, Addr, Decoder);
1688     imm = fieldFromInstruction(insn, 10, 12);
1689     if (!AArch64_AM::isValidDecodeLogicalImmediate(imm, 32))
1690       return Fail;
1691   }
1692   Inst.addOperand(MCOperand::createImm(imm));
1693   return Success;
1694 }
1695 
1696 static DecodeStatus DecodeModImmInstruction(MCInst &Inst, uint32_t insn,
1697                                             uint64_t Addr,
1698                                             const MCDisassembler *Decoder) {
1699   unsigned Rd = fieldFromInstruction(insn, 0, 5);
1700   unsigned cmode = fieldFromInstruction(insn, 12, 4);
1701   unsigned imm = fieldFromInstruction(insn, 16, 3) << 5;
1702   imm |= fieldFromInstruction(insn, 5, 5);
1703 
1704   if (Inst.getOpcode() == AArch64::MOVID)
1705     DecodeFPR64RegisterClass(Inst, Rd, Addr, Decoder);
1706   else
1707     DecodeFPR128RegisterClass(Inst, Rd, Addr, Decoder);
1708 
1709   Inst.addOperand(MCOperand::createImm(imm));
1710 
1711   switch (Inst.getOpcode()) {
1712   default:
1713     break;
1714   case AArch64::MOVIv4i16:
1715   case AArch64::MOVIv8i16:
1716   case AArch64::MVNIv4i16:
1717   case AArch64::MVNIv8i16:
1718   case AArch64::MOVIv2i32:
1719   case AArch64::MOVIv4i32:
1720   case AArch64::MVNIv2i32:
1721   case AArch64::MVNIv4i32:
1722     Inst.addOperand(MCOperand::createImm((cmode & 6) << 2));
1723     break;
1724   case AArch64::MOVIv2s_msl:
1725   case AArch64::MOVIv4s_msl:
1726   case AArch64::MVNIv2s_msl:
1727   case AArch64::MVNIv4s_msl:
1728     Inst.addOperand(MCOperand::createImm((cmode & 1) ? 0x110 : 0x108));
1729     break;
1730   }
1731 
1732   return Success;
1733 }
1734 
1735 static DecodeStatus DecodeModImmTiedInstruction(MCInst &Inst, uint32_t insn,
1736                                                 uint64_t Addr,
1737                                                 const MCDisassembler *Decoder) {
1738   unsigned Rd = fieldFromInstruction(insn, 0, 5);
1739   unsigned cmode = fieldFromInstruction(insn, 12, 4);
1740   unsigned imm = fieldFromInstruction(insn, 16, 3) << 5;
1741   imm |= fieldFromInstruction(insn, 5, 5);
1742 
1743   // Tied operands added twice.
1744   DecodeFPR128RegisterClass(Inst, Rd, Addr, Decoder);
1745   DecodeFPR128RegisterClass(Inst, Rd, Addr, Decoder);
1746 
1747   Inst.addOperand(MCOperand::createImm(imm));
1748   Inst.addOperand(MCOperand::createImm((cmode & 6) << 2));
1749 
1750   return Success;
1751 }
1752 
1753 static DecodeStatus DecodeAdrInstruction(MCInst &Inst, uint32_t insn,
1754                                          uint64_t Addr,
1755                                          const MCDisassembler *Decoder) {
1756   unsigned Rd = fieldFromInstruction(insn, 0, 5);
1757   int64_t imm = fieldFromInstruction(insn, 5, 19) << 2;
1758   imm |= fieldFromInstruction(insn, 29, 2);
1759 
1760   // Sign-extend the 21-bit immediate.
1761   if (imm & (1 << (21 - 1)))
1762     imm |= ~((1LL << 21) - 1);
1763 
1764   DecodeGPR64RegisterClass(Inst, Rd, Addr, Decoder);
1765   if (!Decoder->tryAddingSymbolicOperand(Inst, imm, Addr, Fail, 0, 0, 4))
1766     Inst.addOperand(MCOperand::createImm(imm));
1767 
1768   return Success;
1769 }
1770 
1771 static DecodeStatus DecodeAddSubImmShift(MCInst &Inst, uint32_t insn,
1772                                          uint64_t Addr,
1773                                          const MCDisassembler *Decoder) {
1774   unsigned Rd = fieldFromInstruction(insn, 0, 5);
1775   unsigned Rn = fieldFromInstruction(insn, 5, 5);
1776   unsigned Imm = fieldFromInstruction(insn, 10, 14);
1777   unsigned S = fieldFromInstruction(insn, 29, 1);
1778   unsigned Datasize = fieldFromInstruction(insn, 31, 1);
1779 
1780   unsigned ShifterVal = (Imm >> 12) & 3;
1781   unsigned ImmVal = Imm & 0xFFF;
1782 
1783   if (ShifterVal != 0 && ShifterVal != 1)
1784     return Fail;
1785 
1786   if (Datasize) {
1787     if (Rd == 31 && !S)
1788       DecodeGPR64spRegisterClass(Inst, Rd, Addr, Decoder);
1789     else
1790       DecodeGPR64RegisterClass(Inst, Rd, Addr, Decoder);
1791     DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);
1792   } else {
1793     if (Rd == 31 && !S)
1794       DecodeGPR32spRegisterClass(Inst, Rd, Addr, Decoder);
1795     else
1796       DecodeGPR32RegisterClass(Inst, Rd, Addr, Decoder);
1797     DecodeGPR32spRegisterClass(Inst, Rn, Addr, Decoder);
1798   }
1799 
1800   if (!Decoder->tryAddingSymbolicOperand(Inst, Imm, Addr, Fail, 0, 0, 4))
1801     Inst.addOperand(MCOperand::createImm(ImmVal));
1802   Inst.addOperand(MCOperand::createImm(12 * ShifterVal));
1803   return Success;
1804 }
1805 
1806 static DecodeStatus DecodeUnconditionalBranch(MCInst &Inst, uint32_t insn,
1807                                               uint64_t Addr,
1808                                               const MCDisassembler *Decoder) {
1809   int64_t imm = fieldFromInstruction(insn, 0, 26);
1810 
1811   // Sign-extend the 26-bit immediate.
1812   if (imm & (1 << (26 - 1)))
1813     imm |= ~((1LL << 26) - 1);
1814 
1815   if (!Decoder->tryAddingSymbolicOperand(Inst, imm * 4, Addr, true, 0, 0, 4))
1816     Inst.addOperand(MCOperand::createImm(imm));
1817 
1818   return Success;
1819 }
1820 
1821 static bool isInvalidPState(uint64_t Op1, uint64_t Op2) {
1822   return Op1 == 0b000 && (Op2 == 0b000 || // CFINV
1823                           Op2 == 0b001 || // XAFlag
1824                           Op2 == 0b010);  // AXFlag
1825 }
1826 
1827 static DecodeStatus
1828 DecodeSystemPStateImm0_15Instruction(MCInst &Inst, uint32_t insn, uint64_t Addr,
1829                                      const MCDisassembler *Decoder) {
1830   uint64_t op1 = fieldFromInstruction(insn, 16, 3);
1831   uint64_t op2 = fieldFromInstruction(insn, 5, 3);
1832   uint64_t imm = fieldFromInstruction(insn, 8, 4);
1833   uint64_t pstate_field = (op1 << 3) | op2;
1834 
1835   if (isInvalidPState(op1, op2))
1836     return Fail;
1837 
1838   Inst.addOperand(MCOperand::createImm(pstate_field));
1839   Inst.addOperand(MCOperand::createImm(imm));
1840 
1841   auto PState = AArch64PState::lookupPStateImm0_15ByEncoding(pstate_field);
1842   if (PState &&
1843       PState->haveFeatures(Decoder->getSubtargetInfo().getFeatureBits()))
1844     return Success;
1845   return Fail;
1846 }
1847 
1848 static DecodeStatus
1849 DecodeSystemPStateImm0_1Instruction(MCInst &Inst, uint32_t insn, uint64_t Addr,
1850                                     const MCDisassembler *Decoder) {
1851   uint64_t op1 = fieldFromInstruction(insn, 16, 3);
1852   uint64_t op2 = fieldFromInstruction(insn, 5, 3);
1853   uint64_t crm_high = fieldFromInstruction(insn, 9, 3);
1854   uint64_t imm = fieldFromInstruction(insn, 8, 1);
1855   uint64_t pstate_field = (crm_high << 6) | (op1 << 3) | op2;
1856 
1857   if (isInvalidPState(op1, op2))
1858     return Fail;
1859 
1860   Inst.addOperand(MCOperand::createImm(pstate_field));
1861   Inst.addOperand(MCOperand::createImm(imm));
1862 
1863   auto PState = AArch64PState::lookupPStateImm0_1ByEncoding(pstate_field);
1864   if (PState &&
1865       PState->haveFeatures(Decoder->getSubtargetInfo().getFeatureBits()))
1866     return Success;
1867   return Fail;
1868 }
1869 
1870 static DecodeStatus DecodeTestAndBranch(MCInst &Inst, uint32_t insn,
1871                                         uint64_t Addr,
1872                                         const MCDisassembler *Decoder) {
1873   uint64_t Rt = fieldFromInstruction(insn, 0, 5);
1874   uint64_t bit = fieldFromInstruction(insn, 31, 1) << 5;
1875   bit |= fieldFromInstruction(insn, 19, 5);
1876   int64_t dst = fieldFromInstruction(insn, 5, 14);
1877 
1878   // Sign-extend 14-bit immediate.
1879   if (dst & (1 << (14 - 1)))
1880     dst |= ~((1LL << 14) - 1);
1881 
1882   if (fieldFromInstruction(insn, 31, 1) == 0)
1883     DecodeGPR32RegisterClass(Inst, Rt, Addr, Decoder);
1884   else
1885     DecodeGPR64RegisterClass(Inst, Rt, Addr, Decoder);
1886   Inst.addOperand(MCOperand::createImm(bit));
1887   if (!Decoder->tryAddingSymbolicOperand(Inst, dst * 4, Addr, true, 0, 0, 4))
1888     Inst.addOperand(MCOperand::createImm(dst));
1889 
1890   return Success;
1891 }
1892 
1893 static DecodeStatus
1894 DecodeGPRSeqPairsClassRegisterClass(MCInst &Inst, unsigned RegClassID,
1895                                     unsigned RegNo, uint64_t Addr,
1896                                     const MCDisassembler *Decoder) {
1897   // Register number must be even (see CASP instruction)
1898   if (RegNo & 0x1)
1899     return Fail;
1900 
1901   unsigned Reg = AArch64MCRegisterClasses[RegClassID].getRegister(RegNo / 2);
1902   Inst.addOperand(MCOperand::createReg(Reg));
1903   return Success;
1904 }
1905 
1906 static DecodeStatus
1907 DecodeWSeqPairsClassRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Addr,
1908                                   const MCDisassembler *Decoder) {
1909   return DecodeGPRSeqPairsClassRegisterClass(Inst,
1910                                              AArch64::WSeqPairsClassRegClassID,
1911                                              RegNo, Addr, Decoder);
1912 }
1913 
1914 static DecodeStatus
1915 DecodeXSeqPairsClassRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Addr,
1916                                   const MCDisassembler *Decoder) {
1917   return DecodeGPRSeqPairsClassRegisterClass(Inst,
1918                                              AArch64::XSeqPairsClassRegClassID,
1919                                              RegNo, Addr, Decoder);
1920 }
1921 
1922 static DecodeStatus DecodeSyspXzrInstruction(MCInst &Inst, uint32_t insn,
1923                                              uint64_t Addr,
1924                                              const MCDisassembler *Decoder) {
1925   unsigned op1 = fieldFromInstruction(insn, 16, 3);
1926   unsigned CRn = fieldFromInstruction(insn, 12, 4);
1927   unsigned CRm = fieldFromInstruction(insn, 8, 4);
1928   unsigned op2 = fieldFromInstruction(insn, 5, 3);
1929   unsigned Rt = fieldFromInstruction(insn, 0, 5);
1930   if (Rt != 0b11111)
1931     return Fail;
1932 
1933   Inst.addOperand(MCOperand::createImm(op1));
1934   Inst.addOperand(MCOperand::createImm(CRn));
1935   Inst.addOperand(MCOperand::createImm(CRm));
1936   Inst.addOperand(MCOperand::createImm(op2));
1937   DecodeGPR64RegisterClass(Inst, Rt, Addr, Decoder);
1938 
1939   return Success;
1940 }
1941 
1942 static DecodeStatus
1943 DecodeSVELogicalImmInstruction(MCInst &Inst, uint32_t insn, uint64_t Addr,
1944                                const MCDisassembler *Decoder) {
1945   unsigned Zdn = fieldFromInstruction(insn, 0, 5);
1946   unsigned imm = fieldFromInstruction(insn, 5, 13);
1947   if (!AArch64_AM::isValidDecodeLogicalImmediate(imm, 64))
1948     return Fail;
1949 
1950   // The same (tied) operand is added twice to the instruction.
1951   DecodeZPRRegisterClass(Inst, Zdn, Addr, Decoder);
1952   if (Inst.getOpcode() != AArch64::DUPM_ZI)
1953     DecodeZPRRegisterClass(Inst, Zdn, Addr, Decoder);
1954   Inst.addOperand(MCOperand::createImm(imm));
1955   return Success;
1956 }
1957 
1958 template <int Bits>
1959 static DecodeStatus DecodeSImm(MCInst &Inst, uint64_t Imm, uint64_t Address,
1960                                const MCDisassembler *Decoder) {
1961   if (Imm & ~((1LL << Bits) - 1))
1962       return Fail;
1963 
1964   // Imm is a signed immediate, so sign extend it.
1965   if (Imm & (1 << (Bits - 1)))
1966     Imm |= ~((1LL << Bits) - 1);
1967 
1968   Inst.addOperand(MCOperand::createImm(Imm));
1969   return Success;
1970 }
1971 
1972 // Decode 8-bit signed/unsigned immediate for a given element width.
1973 template <int ElementWidth>
1974 static DecodeStatus DecodeImm8OptLsl(MCInst &Inst, unsigned Imm, uint64_t Addr,
1975                                      const MCDisassembler *Decoder) {
1976   unsigned Val = (uint8_t)Imm;
1977   unsigned Shift = (Imm & 0x100) ? 8 : 0;
1978   if (ElementWidth == 8 && Shift)
1979     return Fail;
1980   Inst.addOperand(MCOperand::createImm(Val));
1981   Inst.addOperand(MCOperand::createImm(Shift));
1982   return Success;
1983 }
1984 
1985 // Decode uimm4 ranged from 1-16.
1986 static DecodeStatus DecodeSVEIncDecImm(MCInst &Inst, unsigned Imm,
1987                                        uint64_t Addr,
1988                                        const MCDisassembler *Decoder) {
1989   Inst.addOperand(MCOperand::createImm(Imm + 1));
1990   return Success;
1991 }
1992 
1993 static DecodeStatus DecodeSVCROp(MCInst &Inst, unsigned Imm, uint64_t Address,
1994                                  const MCDisassembler *Decoder) {
1995   if (AArch64SVCR::lookupSVCRByEncoding(Imm)) {
1996     Inst.addOperand(MCOperand::createImm(Imm));
1997     return Success;
1998   }
1999   return Fail;
2000 }
2001 
2002 static DecodeStatus DecodeCPYMemOpInstruction(MCInst &Inst, uint32_t insn,
2003                                               uint64_t Addr,
2004                                               const MCDisassembler *Decoder) {
2005   unsigned Rd = fieldFromInstruction(insn, 0, 5);
2006   unsigned Rs = fieldFromInstruction(insn, 16, 5);
2007   unsigned Rn = fieldFromInstruction(insn, 5, 5);
2008 
2009   // None of the registers may alias: if they do, then the instruction is not
2010   // merely unpredictable but actually entirely unallocated.
2011   if (Rd == Rs || Rs == Rn || Rd == Rn)
2012     return MCDisassembler::Fail;
2013 
2014   // All three register operands are written back, so they all appear
2015   // twice in the operand list, once as outputs and once as inputs.
2016   if (!DecodeGPR64commonRegisterClass(Inst, Rd, Addr, Decoder) ||
2017       !DecodeGPR64commonRegisterClass(Inst, Rs, Addr, Decoder) ||
2018       !DecodeGPR64RegisterClass(Inst, Rn, Addr, Decoder) ||
2019       !DecodeGPR64commonRegisterClass(Inst, Rd, Addr, Decoder) ||
2020       !DecodeGPR64commonRegisterClass(Inst, Rs, Addr, Decoder) ||
2021       !DecodeGPR64RegisterClass(Inst, Rn, Addr, Decoder))
2022     return MCDisassembler::Fail;
2023 
2024   return MCDisassembler::Success;
2025 }
2026 
2027 static DecodeStatus DecodeSETMemOpInstruction(MCInst &Inst, uint32_t insn,
2028                                               uint64_t Addr,
2029                                               const MCDisassembler *Decoder) {
2030   unsigned Rd = fieldFromInstruction(insn, 0, 5);
2031   unsigned Rm = fieldFromInstruction(insn, 16, 5);
2032   unsigned Rn = fieldFromInstruction(insn, 5, 5);
2033 
2034   // None of the registers may alias: if they do, then the instruction is not
2035   // merely unpredictable but actually entirely unallocated.
2036   if (Rd == Rm || Rm == Rn || Rd == Rn)
2037     return MCDisassembler::Fail;
2038 
2039   // Rd and Rn (not Rm) register operands are written back, so they appear
2040   // twice in the operand list, once as outputs and once as inputs.
2041   if (!DecodeGPR64commonRegisterClass(Inst, Rd, Addr, Decoder) ||
2042       !DecodeGPR64RegisterClass(Inst, Rn, Addr, Decoder) ||
2043       !DecodeGPR64commonRegisterClass(Inst, Rd, Addr, Decoder) ||
2044       !DecodeGPR64RegisterClass(Inst, Rn, Addr, Decoder) ||
2045       !DecodeGPR64RegisterClass(Inst, Rm, Addr, Decoder))
2046     return MCDisassembler::Fail;
2047 
2048   return MCDisassembler::Success;
2049 }
2050 
2051 static DecodeStatus DecodePRFMRegInstruction(MCInst &Inst, uint32_t insn,
2052                                              uint64_t Addr,
2053                                              const MCDisassembler *Decoder) {
2054   // PRFM with Rt = '11xxx' should be decoded as RPRFM.
2055   // Fail to decode and defer to fallback decoder table to decode RPRFM.
2056   unsigned Mask = 0x18;
2057   uint64_t Rt = fieldFromInstruction(insn, 0, 5);
2058   if ((Rt & Mask) == Mask)
2059     return Fail;
2060 
2061   uint64_t Rn = fieldFromInstruction(insn, 5, 5);
2062   uint64_t Shift = fieldFromInstruction(insn, 12, 1);
2063   uint64_t Extend = fieldFromInstruction(insn, 15, 1);
2064   uint64_t Rm = fieldFromInstruction(insn, 16, 5);
2065 
2066   Inst.addOperand(MCOperand::createImm(Rt));
2067   DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);
2068 
2069   switch (Inst.getOpcode()) {
2070   default:
2071     return Fail;
2072   case AArch64::PRFMroW:
2073     DecodeGPR32RegisterClass(Inst, Rm, Addr, Decoder);
2074     break;
2075   case AArch64::PRFMroX:
2076     DecodeGPR64RegisterClass(Inst, Rm, Addr, Decoder);
2077     break;
2078   }
2079 
2080   DecodeMemExtend(Inst, (Extend << 1) | Shift, Addr, Decoder);
2081 
2082   return Success;
2083 }
2084