1 //===- AArch64Disassembler.cpp - Disassembler for AArch64 -------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "AArch64Disassembler.h"
14 #include "AArch64ExternalSymbolizer.h"
15 #include "AArch64Subtarget.h"
16 #include "MCTargetDesc/AArch64AddressingModes.h"
17 #include "Utils/AArch64BaseInfo.h"
18 #include "llvm/MC/MCFixedLenDisassembler.h"
19 #include "llvm/MC/MCInst.h"
20 #include "llvm/Support/Debug.h"
21 #include "llvm/Support/ErrorHandling.h"
22 #include "llvm/Support/MemoryObject.h"
23 #include "llvm/Support/TargetRegistry.h"
24 
25 using namespace llvm;
26 
27 #define DEBUG_TYPE "aarch64-disassembler"
28 
29 // Pull DecodeStatus and its enum values into the global namespace.
30 typedef llvm::MCDisassembler::DecodeStatus DecodeStatus;
31 
32 // Forward declare these because the autogenerated code will reference them.
33 // Definitions are further down.
34 static DecodeStatus DecodeFPR128RegisterClass(llvm::MCInst &Inst,
35                                               unsigned RegNo, uint64_t Address,
36                                               const void *Decoder);
37 static DecodeStatus DecodeFPR128_loRegisterClass(llvm::MCInst &Inst,
38                                                  unsigned RegNo,
39                                                  uint64_t Address,
40                                                  const void *Decoder);
41 static DecodeStatus DecodeFPR64RegisterClass(llvm::MCInst &Inst, unsigned RegNo,
42                                              uint64_t Address,
43                                              const void *Decoder);
44 static DecodeStatus DecodeFPR32RegisterClass(llvm::MCInst &Inst, unsigned RegNo,
45                                              uint64_t Address,
46                                              const void *Decoder);
47 static DecodeStatus DecodeFPR16RegisterClass(llvm::MCInst &Inst, unsigned RegNo,
48                                              uint64_t Address,
49                                              const void *Decoder);
50 static DecodeStatus DecodeFPR8RegisterClass(llvm::MCInst &Inst, unsigned RegNo,
51                                             uint64_t Address,
52                                             const void *Decoder);
53 static DecodeStatus DecodeGPR64RegisterClass(llvm::MCInst &Inst, unsigned RegNo,
54                                              uint64_t Address,
55                                              const void *Decoder);
56 static DecodeStatus DecodeGPR64spRegisterClass(llvm::MCInst &Inst,
57                                                unsigned RegNo, uint64_t Address,
58                                                const void *Decoder);
59 static DecodeStatus DecodeGPR32RegisterClass(llvm::MCInst &Inst, unsigned RegNo,
60                                              uint64_t Address,
61                                              const void *Decoder);
62 static DecodeStatus DecodeGPR32spRegisterClass(llvm::MCInst &Inst,
63                                                unsigned RegNo, uint64_t Address,
64                                                const void *Decoder);
65 static DecodeStatus DecodeQQRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
66                                           uint64_t Address,
67                                           const void *Decoder);
68 static DecodeStatus DecodeQQQRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
69                                            uint64_t Address,
70                                            const void *Decoder);
71 static DecodeStatus DecodeQQQQRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
72                                             uint64_t Address,
73                                             const void *Decoder);
74 static DecodeStatus DecodeDDRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
75                                           uint64_t Address,
76                                           const void *Decoder);
77 static DecodeStatus DecodeDDDRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
78                                            uint64_t Address,
79                                            const void *Decoder);
80 static DecodeStatus DecodeDDDDRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
81                                             uint64_t Address,
82                                             const void *Decoder);
83 
84 static DecodeStatus DecodeFixedPointScaleImm32(llvm::MCInst &Inst, unsigned Imm,
85                                                uint64_t Address,
86                                                const void *Decoder);
87 static DecodeStatus DecodeFixedPointScaleImm64(llvm::MCInst &Inst, unsigned Imm,
88                                                uint64_t Address,
89                                                const void *Decoder);
90 static DecodeStatus DecodePCRelLabel19(llvm::MCInst &Inst, unsigned Imm,
91                                        uint64_t Address, const void *Decoder);
92 static DecodeStatus DecodeMemExtend(llvm::MCInst &Inst, unsigned Imm,
93                                     uint64_t Address, const void *Decoder);
94 static DecodeStatus DecodeMRSSystemRegister(llvm::MCInst &Inst, unsigned Imm,
95                                             uint64_t Address, const void *Decoder);
96 static DecodeStatus DecodeMSRSystemRegister(llvm::MCInst &Inst, unsigned Imm,
97                                             uint64_t Address, const void *Decoder);
98 static DecodeStatus DecodeThreeAddrSRegInstruction(llvm::MCInst &Inst,
99                                                    uint32_t insn,
100                                                    uint64_t Address,
101                                                    const void *Decoder);
102 static DecodeStatus DecodeMoveImmInstruction(llvm::MCInst &Inst, uint32_t insn,
103                                              uint64_t Address,
104                                              const void *Decoder);
105 static DecodeStatus DecodeUnsignedLdStInstruction(llvm::MCInst &Inst,
106                                                   uint32_t insn,
107                                                   uint64_t Address,
108                                                   const void *Decoder);
109 static DecodeStatus DecodeSignedLdStInstruction(llvm::MCInst &Inst,
110                                                 uint32_t insn, uint64_t Address,
111                                                 const void *Decoder);
112 static DecodeStatus DecodeExclusiveLdStInstruction(llvm::MCInst &Inst,
113                                                    uint32_t insn,
114                                                    uint64_t Address,
115                                                    const void *Decoder);
116 static DecodeStatus DecodePairLdStInstruction(llvm::MCInst &Inst, uint32_t insn,
117                                               uint64_t Address,
118                                               const void *Decoder);
119 static DecodeStatus DecodeAddSubERegInstruction(llvm::MCInst &Inst,
120                                                 uint32_t insn, uint64_t Address,
121                                                 const void *Decoder);
122 static DecodeStatus DecodeLogicalImmInstruction(llvm::MCInst &Inst,
123                                                 uint32_t insn, uint64_t Address,
124                                                 const void *Decoder);
125 static DecodeStatus DecodeModImmInstruction(llvm::MCInst &Inst, uint32_t insn,
126                                             uint64_t Address,
127                                             const void *Decoder);
128 static DecodeStatus DecodeModImmTiedInstruction(llvm::MCInst &Inst,
129                                                 uint32_t insn, uint64_t Address,
130                                                 const void *Decoder);
131 static DecodeStatus DecodeAdrInstruction(llvm::MCInst &Inst, uint32_t insn,
132                                          uint64_t Address, const void *Decoder);
133 static DecodeStatus DecodeBaseAddSubImm(llvm::MCInst &Inst, uint32_t insn,
134                                         uint64_t Address, const void *Decoder);
135 static DecodeStatus DecodeUnconditionalBranch(llvm::MCInst &Inst, uint32_t insn,
136                                               uint64_t Address,
137                                               const void *Decoder);
138 static DecodeStatus DecodeSystemPStateInstruction(llvm::MCInst &Inst,
139                                                   uint32_t insn,
140                                                   uint64_t Address,
141                                                   const void *Decoder);
142 static DecodeStatus DecodeTestAndBranch(llvm::MCInst &Inst, uint32_t insn,
143                                         uint64_t Address, const void *Decoder);
144 
145 static DecodeStatus DecodeFMOVLaneInstruction(llvm::MCInst &Inst, unsigned Insn,
146                                               uint64_t Address,
147                                               const void *Decoder);
148 static DecodeStatus DecodeVecShiftR64Imm(llvm::MCInst &Inst, unsigned Imm,
149                                          uint64_t Addr, const void *Decoder);
150 static DecodeStatus DecodeVecShiftR64ImmNarrow(llvm::MCInst &Inst, unsigned Imm,
151                                                uint64_t Addr,
152                                                const void *Decoder);
153 static DecodeStatus DecodeVecShiftR32Imm(llvm::MCInst &Inst, unsigned Imm,
154                                          uint64_t Addr, const void *Decoder);
155 static DecodeStatus DecodeVecShiftR32ImmNarrow(llvm::MCInst &Inst, unsigned Imm,
156                                                uint64_t Addr,
157                                                const void *Decoder);
158 static DecodeStatus DecodeVecShiftR16Imm(llvm::MCInst &Inst, unsigned Imm,
159                                          uint64_t Addr, const void *Decoder);
160 static DecodeStatus DecodeVecShiftR16ImmNarrow(llvm::MCInst &Inst, unsigned Imm,
161                                                uint64_t Addr,
162                                                const void *Decoder);
163 static DecodeStatus DecodeVecShiftR8Imm(llvm::MCInst &Inst, unsigned Imm,
164                                         uint64_t Addr, const void *Decoder);
165 static DecodeStatus DecodeVecShiftL64Imm(llvm::MCInst &Inst, unsigned Imm,
166                                          uint64_t Addr, const void *Decoder);
167 static DecodeStatus DecodeVecShiftL32Imm(llvm::MCInst &Inst, unsigned Imm,
168                                          uint64_t Addr, const void *Decoder);
169 static DecodeStatus DecodeVecShiftL16Imm(llvm::MCInst &Inst, unsigned Imm,
170                                          uint64_t Addr, const void *Decoder);
171 static DecodeStatus DecodeVecShiftL8Imm(llvm::MCInst &Inst, unsigned Imm,
172                                         uint64_t Addr, const void *Decoder);
173 
174 static bool Check(DecodeStatus &Out, DecodeStatus In) {
175   switch (In) {
176     case MCDisassembler::Success:
177       // Out stays the same.
178       return true;
179     case MCDisassembler::SoftFail:
180       Out = In;
181       return true;
182     case MCDisassembler::Fail:
183       Out = In;
184       return false;
185   }
186   llvm_unreachable("Invalid DecodeStatus!");
187 }
188 
189 #include "AArch64GenDisassemblerTables.inc"
190 #include "AArch64GenInstrInfo.inc"
191 
192 #define Success llvm::MCDisassembler::Success
193 #define Fail llvm::MCDisassembler::Fail
194 #define SoftFail llvm::MCDisassembler::SoftFail
195 
196 static MCDisassembler *createAArch64Disassembler(const Target &T,
197                                                const MCSubtargetInfo &STI,
198                                                MCContext &Ctx) {
199   return new AArch64Disassembler(STI, Ctx);
200 }
201 
202 DecodeStatus AArch64Disassembler::getInstruction(MCInst &MI, uint64_t &Size,
203                                                const MemoryObject &Region,
204                                                uint64_t Address,
205                                                raw_ostream &os,
206                                                raw_ostream &cs) const {
207   CommentStream = &cs;
208 
209   uint8_t bytes[4];
210 
211   Size = 0;
212   // We want to read exactly 4 bytes of data.
213   if (Region.readBytes(Address, 4, (uint8_t *)bytes) == -1)
214     return Fail;
215   Size = 4;
216 
217   // Encoded as a small-endian 32-bit word in the stream.
218   uint32_t insn =
219       (bytes[3] << 24) | (bytes[2] << 16) | (bytes[1] << 8) | (bytes[0] << 0);
220 
221   // Calling the auto-generated decoder function.
222   return decodeInstruction(DecoderTable32, MI, insn, Address, this, STI);
223 }
224 
225 static MCSymbolizer *
226 createAArch64ExternalSymbolizer(StringRef TT, LLVMOpInfoCallback GetOpInfo,
227                               LLVMSymbolLookupCallback SymbolLookUp,
228                               void *DisInfo, MCContext *Ctx,
229                               MCRelocationInfo *RelInfo) {
230   return new llvm::AArch64ExternalSymbolizer(
231                                      *Ctx,
232                                      std::unique_ptr<MCRelocationInfo>(RelInfo),
233                                      GetOpInfo, SymbolLookUp, DisInfo);
234 }
235 
236 extern "C" void LLVMInitializeAArch64Disassembler() {
237   TargetRegistry::RegisterMCDisassembler(TheAArch64leTarget,
238                                          createAArch64Disassembler);
239   TargetRegistry::RegisterMCDisassembler(TheAArch64beTarget,
240                                          createAArch64Disassembler);
241   TargetRegistry::RegisterMCSymbolizer(TheAArch64leTarget,
242                                        createAArch64ExternalSymbolizer);
243   TargetRegistry::RegisterMCSymbolizer(TheAArch64beTarget,
244                                        createAArch64ExternalSymbolizer);
245 
246   TargetRegistry::RegisterMCDisassembler(TheARM64Target,
247                                          createAArch64Disassembler);
248   TargetRegistry::RegisterMCSymbolizer(TheARM64Target,
249                                        createAArch64ExternalSymbolizer);
250 }
251 
252 static const unsigned FPR128DecoderTable[] = {
253     AArch64::Q0,  AArch64::Q1,  AArch64::Q2,  AArch64::Q3,  AArch64::Q4,
254     AArch64::Q5,  AArch64::Q6,  AArch64::Q7,  AArch64::Q8,  AArch64::Q9,
255     AArch64::Q10, AArch64::Q11, AArch64::Q12, AArch64::Q13, AArch64::Q14,
256     AArch64::Q15, AArch64::Q16, AArch64::Q17, AArch64::Q18, AArch64::Q19,
257     AArch64::Q20, AArch64::Q21, AArch64::Q22, AArch64::Q23, AArch64::Q24,
258     AArch64::Q25, AArch64::Q26, AArch64::Q27, AArch64::Q28, AArch64::Q29,
259     AArch64::Q30, AArch64::Q31
260 };
261 
262 static DecodeStatus DecodeFPR128RegisterClass(MCInst &Inst, unsigned RegNo,
263                                               uint64_t Addr,
264                                               const void *Decoder) {
265   if (RegNo > 31)
266     return Fail;
267 
268   unsigned Register = FPR128DecoderTable[RegNo];
269   Inst.addOperand(MCOperand::CreateReg(Register));
270   return Success;
271 }
272 
273 static DecodeStatus DecodeFPR128_loRegisterClass(MCInst &Inst, unsigned RegNo,
274                                                  uint64_t Addr,
275                                                  const void *Decoder) {
276   if (RegNo > 15)
277     return Fail;
278   return DecodeFPR128RegisterClass(Inst, RegNo, Addr, Decoder);
279 }
280 
281 static const unsigned FPR64DecoderTable[] = {
282     AArch64::D0,  AArch64::D1,  AArch64::D2,  AArch64::D3,  AArch64::D4,
283     AArch64::D5,  AArch64::D6,  AArch64::D7,  AArch64::D8,  AArch64::D9,
284     AArch64::D10, AArch64::D11, AArch64::D12, AArch64::D13, AArch64::D14,
285     AArch64::D15, AArch64::D16, AArch64::D17, AArch64::D18, AArch64::D19,
286     AArch64::D20, AArch64::D21, AArch64::D22, AArch64::D23, AArch64::D24,
287     AArch64::D25, AArch64::D26, AArch64::D27, AArch64::D28, AArch64::D29,
288     AArch64::D30, AArch64::D31
289 };
290 
291 static DecodeStatus DecodeFPR64RegisterClass(MCInst &Inst, unsigned RegNo,
292                                              uint64_t Addr,
293                                              const void *Decoder) {
294   if (RegNo > 31)
295     return Fail;
296 
297   unsigned Register = FPR64DecoderTable[RegNo];
298   Inst.addOperand(MCOperand::CreateReg(Register));
299   return Success;
300 }
301 
302 static const unsigned FPR32DecoderTable[] = {
303     AArch64::S0,  AArch64::S1,  AArch64::S2,  AArch64::S3,  AArch64::S4,
304     AArch64::S5,  AArch64::S6,  AArch64::S7,  AArch64::S8,  AArch64::S9,
305     AArch64::S10, AArch64::S11, AArch64::S12, AArch64::S13, AArch64::S14,
306     AArch64::S15, AArch64::S16, AArch64::S17, AArch64::S18, AArch64::S19,
307     AArch64::S20, AArch64::S21, AArch64::S22, AArch64::S23, AArch64::S24,
308     AArch64::S25, AArch64::S26, AArch64::S27, AArch64::S28, AArch64::S29,
309     AArch64::S30, AArch64::S31
310 };
311 
312 static DecodeStatus DecodeFPR32RegisterClass(MCInst &Inst, unsigned RegNo,
313                                              uint64_t Addr,
314                                              const void *Decoder) {
315   if (RegNo > 31)
316     return Fail;
317 
318   unsigned Register = FPR32DecoderTable[RegNo];
319   Inst.addOperand(MCOperand::CreateReg(Register));
320   return Success;
321 }
322 
323 static const unsigned FPR16DecoderTable[] = {
324     AArch64::H0,  AArch64::H1,  AArch64::H2,  AArch64::H3,  AArch64::H4,
325     AArch64::H5,  AArch64::H6,  AArch64::H7,  AArch64::H8,  AArch64::H9,
326     AArch64::H10, AArch64::H11, AArch64::H12, AArch64::H13, AArch64::H14,
327     AArch64::H15, AArch64::H16, AArch64::H17, AArch64::H18, AArch64::H19,
328     AArch64::H20, AArch64::H21, AArch64::H22, AArch64::H23, AArch64::H24,
329     AArch64::H25, AArch64::H26, AArch64::H27, AArch64::H28, AArch64::H29,
330     AArch64::H30, AArch64::H31
331 };
332 
333 static DecodeStatus DecodeFPR16RegisterClass(MCInst &Inst, unsigned RegNo,
334                                              uint64_t Addr,
335                                              const void *Decoder) {
336   if (RegNo > 31)
337     return Fail;
338 
339   unsigned Register = FPR16DecoderTable[RegNo];
340   Inst.addOperand(MCOperand::CreateReg(Register));
341   return Success;
342 }
343 
344 static const unsigned FPR8DecoderTable[] = {
345     AArch64::B0,  AArch64::B1,  AArch64::B2,  AArch64::B3,  AArch64::B4,
346     AArch64::B5,  AArch64::B6,  AArch64::B7,  AArch64::B8,  AArch64::B9,
347     AArch64::B10, AArch64::B11, AArch64::B12, AArch64::B13, AArch64::B14,
348     AArch64::B15, AArch64::B16, AArch64::B17, AArch64::B18, AArch64::B19,
349     AArch64::B20, AArch64::B21, AArch64::B22, AArch64::B23, AArch64::B24,
350     AArch64::B25, AArch64::B26, AArch64::B27, AArch64::B28, AArch64::B29,
351     AArch64::B30, AArch64::B31
352 };
353 
354 static DecodeStatus DecodeFPR8RegisterClass(MCInst &Inst, unsigned RegNo,
355                                             uint64_t Addr,
356                                             const void *Decoder) {
357   if (RegNo > 31)
358     return Fail;
359 
360   unsigned Register = FPR8DecoderTable[RegNo];
361   Inst.addOperand(MCOperand::CreateReg(Register));
362   return Success;
363 }
364 
365 static const unsigned GPR64DecoderTable[] = {
366     AArch64::X0,  AArch64::X1,  AArch64::X2,  AArch64::X3,  AArch64::X4,
367     AArch64::X5,  AArch64::X6,  AArch64::X7,  AArch64::X8,  AArch64::X9,
368     AArch64::X10, AArch64::X11, AArch64::X12, AArch64::X13, AArch64::X14,
369     AArch64::X15, AArch64::X16, AArch64::X17, AArch64::X18, AArch64::X19,
370     AArch64::X20, AArch64::X21, AArch64::X22, AArch64::X23, AArch64::X24,
371     AArch64::X25, AArch64::X26, AArch64::X27, AArch64::X28, AArch64::FP,
372     AArch64::LR,  AArch64::XZR
373 };
374 
375 static DecodeStatus DecodeGPR64RegisterClass(MCInst &Inst, unsigned RegNo,
376                                              uint64_t Addr,
377                                              const void *Decoder) {
378   if (RegNo > 31)
379     return Fail;
380 
381   unsigned Register = GPR64DecoderTable[RegNo];
382   Inst.addOperand(MCOperand::CreateReg(Register));
383   return Success;
384 }
385 
386 static DecodeStatus DecodeGPR64spRegisterClass(MCInst &Inst, unsigned RegNo,
387                                                uint64_t Addr,
388                                                const void *Decoder) {
389   if (RegNo > 31)
390     return Fail;
391   unsigned Register = GPR64DecoderTable[RegNo];
392   if (Register == AArch64::XZR)
393     Register = AArch64::SP;
394   Inst.addOperand(MCOperand::CreateReg(Register));
395   return Success;
396 }
397 
398 static const unsigned GPR32DecoderTable[] = {
399     AArch64::W0,  AArch64::W1,  AArch64::W2,  AArch64::W3,  AArch64::W4,
400     AArch64::W5,  AArch64::W6,  AArch64::W7,  AArch64::W8,  AArch64::W9,
401     AArch64::W10, AArch64::W11, AArch64::W12, AArch64::W13, AArch64::W14,
402     AArch64::W15, AArch64::W16, AArch64::W17, AArch64::W18, AArch64::W19,
403     AArch64::W20, AArch64::W21, AArch64::W22, AArch64::W23, AArch64::W24,
404     AArch64::W25, AArch64::W26, AArch64::W27, AArch64::W28, AArch64::W29,
405     AArch64::W30, AArch64::WZR
406 };
407 
408 static DecodeStatus DecodeGPR32RegisterClass(MCInst &Inst, unsigned RegNo,
409                                              uint64_t Addr,
410                                              const void *Decoder) {
411   if (RegNo > 31)
412     return Fail;
413 
414   unsigned Register = GPR32DecoderTable[RegNo];
415   Inst.addOperand(MCOperand::CreateReg(Register));
416   return Success;
417 }
418 
419 static DecodeStatus DecodeGPR32spRegisterClass(MCInst &Inst, unsigned RegNo,
420                                                uint64_t Addr,
421                                                const void *Decoder) {
422   if (RegNo > 31)
423     return Fail;
424 
425   unsigned Register = GPR32DecoderTable[RegNo];
426   if (Register == AArch64::WZR)
427     Register = AArch64::WSP;
428   Inst.addOperand(MCOperand::CreateReg(Register));
429   return Success;
430 }
431 
432 static const unsigned VectorDecoderTable[] = {
433     AArch64::Q0,  AArch64::Q1,  AArch64::Q2,  AArch64::Q3,  AArch64::Q4,
434     AArch64::Q5,  AArch64::Q6,  AArch64::Q7,  AArch64::Q8,  AArch64::Q9,
435     AArch64::Q10, AArch64::Q11, AArch64::Q12, AArch64::Q13, AArch64::Q14,
436     AArch64::Q15, AArch64::Q16, AArch64::Q17, AArch64::Q18, AArch64::Q19,
437     AArch64::Q20, AArch64::Q21, AArch64::Q22, AArch64::Q23, AArch64::Q24,
438     AArch64::Q25, AArch64::Q26, AArch64::Q27, AArch64::Q28, AArch64::Q29,
439     AArch64::Q30, AArch64::Q31
440 };
441 
442 static DecodeStatus DecodeVectorRegisterClass(MCInst &Inst, unsigned RegNo,
443                                               uint64_t Addr,
444                                               const void *Decoder) {
445   if (RegNo > 31)
446     return Fail;
447 
448   unsigned Register = VectorDecoderTable[RegNo];
449   Inst.addOperand(MCOperand::CreateReg(Register));
450   return Success;
451 }
452 
453 static const unsigned QQDecoderTable[] = {
454   AArch64::Q0_Q1,   AArch64::Q1_Q2,   AArch64::Q2_Q3,   AArch64::Q3_Q4,
455   AArch64::Q4_Q5,   AArch64::Q5_Q6,   AArch64::Q6_Q7,   AArch64::Q7_Q8,
456   AArch64::Q8_Q9,   AArch64::Q9_Q10,  AArch64::Q10_Q11, AArch64::Q11_Q12,
457   AArch64::Q12_Q13, AArch64::Q13_Q14, AArch64::Q14_Q15, AArch64::Q15_Q16,
458   AArch64::Q16_Q17, AArch64::Q17_Q18, AArch64::Q18_Q19, AArch64::Q19_Q20,
459   AArch64::Q20_Q21, AArch64::Q21_Q22, AArch64::Q22_Q23, AArch64::Q23_Q24,
460   AArch64::Q24_Q25, AArch64::Q25_Q26, AArch64::Q26_Q27, AArch64::Q27_Q28,
461   AArch64::Q28_Q29, AArch64::Q29_Q30, AArch64::Q30_Q31, AArch64::Q31_Q0
462 };
463 
464 static DecodeStatus DecodeQQRegisterClass(MCInst &Inst, unsigned RegNo,
465                                           uint64_t Addr, const void *Decoder) {
466   if (RegNo > 31)
467     return Fail;
468   unsigned Register = QQDecoderTable[RegNo];
469   Inst.addOperand(MCOperand::CreateReg(Register));
470   return Success;
471 }
472 
473 static const unsigned QQQDecoderTable[] = {
474   AArch64::Q0_Q1_Q2,    AArch64::Q1_Q2_Q3,    AArch64::Q2_Q3_Q4,
475   AArch64::Q3_Q4_Q5,    AArch64::Q4_Q5_Q6,    AArch64::Q5_Q6_Q7,
476   AArch64::Q6_Q7_Q8,    AArch64::Q7_Q8_Q9,    AArch64::Q8_Q9_Q10,
477   AArch64::Q9_Q10_Q11,  AArch64::Q10_Q11_Q12, AArch64::Q11_Q12_Q13,
478   AArch64::Q12_Q13_Q14, AArch64::Q13_Q14_Q15, AArch64::Q14_Q15_Q16,
479   AArch64::Q15_Q16_Q17, AArch64::Q16_Q17_Q18, AArch64::Q17_Q18_Q19,
480   AArch64::Q18_Q19_Q20, AArch64::Q19_Q20_Q21, AArch64::Q20_Q21_Q22,
481   AArch64::Q21_Q22_Q23, AArch64::Q22_Q23_Q24, AArch64::Q23_Q24_Q25,
482   AArch64::Q24_Q25_Q26, AArch64::Q25_Q26_Q27, AArch64::Q26_Q27_Q28,
483   AArch64::Q27_Q28_Q29, AArch64::Q28_Q29_Q30, AArch64::Q29_Q30_Q31,
484   AArch64::Q30_Q31_Q0,  AArch64::Q31_Q0_Q1
485 };
486 
487 static DecodeStatus DecodeQQQRegisterClass(MCInst &Inst, unsigned RegNo,
488                                            uint64_t Addr, const void *Decoder) {
489   if (RegNo > 31)
490     return Fail;
491   unsigned Register = QQQDecoderTable[RegNo];
492   Inst.addOperand(MCOperand::CreateReg(Register));
493   return Success;
494 }
495 
496 static const unsigned QQQQDecoderTable[] = {
497   AArch64::Q0_Q1_Q2_Q3,     AArch64::Q1_Q2_Q3_Q4,     AArch64::Q2_Q3_Q4_Q5,
498   AArch64::Q3_Q4_Q5_Q6,     AArch64::Q4_Q5_Q6_Q7,     AArch64::Q5_Q6_Q7_Q8,
499   AArch64::Q6_Q7_Q8_Q9,     AArch64::Q7_Q8_Q9_Q10,    AArch64::Q8_Q9_Q10_Q11,
500   AArch64::Q9_Q10_Q11_Q12,  AArch64::Q10_Q11_Q12_Q13, AArch64::Q11_Q12_Q13_Q14,
501   AArch64::Q12_Q13_Q14_Q15, AArch64::Q13_Q14_Q15_Q16, AArch64::Q14_Q15_Q16_Q17,
502   AArch64::Q15_Q16_Q17_Q18, AArch64::Q16_Q17_Q18_Q19, AArch64::Q17_Q18_Q19_Q20,
503   AArch64::Q18_Q19_Q20_Q21, AArch64::Q19_Q20_Q21_Q22, AArch64::Q20_Q21_Q22_Q23,
504   AArch64::Q21_Q22_Q23_Q24, AArch64::Q22_Q23_Q24_Q25, AArch64::Q23_Q24_Q25_Q26,
505   AArch64::Q24_Q25_Q26_Q27, AArch64::Q25_Q26_Q27_Q28, AArch64::Q26_Q27_Q28_Q29,
506   AArch64::Q27_Q28_Q29_Q30, AArch64::Q28_Q29_Q30_Q31, AArch64::Q29_Q30_Q31_Q0,
507   AArch64::Q30_Q31_Q0_Q1,   AArch64::Q31_Q0_Q1_Q2
508 };
509 
510 static DecodeStatus DecodeQQQQRegisterClass(MCInst &Inst, unsigned RegNo,
511                                             uint64_t Addr,
512                                             const void *Decoder) {
513   if (RegNo > 31)
514     return Fail;
515   unsigned Register = QQQQDecoderTable[RegNo];
516   Inst.addOperand(MCOperand::CreateReg(Register));
517   return Success;
518 }
519 
520 static const unsigned DDDecoderTable[] = {
521   AArch64::D0_D1,   AArch64::D1_D2,   AArch64::D2_D3,   AArch64::D3_D4,
522   AArch64::D4_D5,   AArch64::D5_D6,   AArch64::D6_D7,   AArch64::D7_D8,
523   AArch64::D8_D9,   AArch64::D9_D10,  AArch64::D10_D11, AArch64::D11_D12,
524   AArch64::D12_D13, AArch64::D13_D14, AArch64::D14_D15, AArch64::D15_D16,
525   AArch64::D16_D17, AArch64::D17_D18, AArch64::D18_D19, AArch64::D19_D20,
526   AArch64::D20_D21, AArch64::D21_D22, AArch64::D22_D23, AArch64::D23_D24,
527   AArch64::D24_D25, AArch64::D25_D26, AArch64::D26_D27, AArch64::D27_D28,
528   AArch64::D28_D29, AArch64::D29_D30, AArch64::D30_D31, AArch64::D31_D0
529 };
530 
531 static DecodeStatus DecodeDDRegisterClass(MCInst &Inst, unsigned RegNo,
532                                           uint64_t Addr, const void *Decoder) {
533   if (RegNo > 31)
534     return Fail;
535   unsigned Register = DDDecoderTable[RegNo];
536   Inst.addOperand(MCOperand::CreateReg(Register));
537   return Success;
538 }
539 
540 static const unsigned DDDDecoderTable[] = {
541   AArch64::D0_D1_D2,    AArch64::D1_D2_D3,    AArch64::D2_D3_D4,
542   AArch64::D3_D4_D5,    AArch64::D4_D5_D6,    AArch64::D5_D6_D7,
543   AArch64::D6_D7_D8,    AArch64::D7_D8_D9,    AArch64::D8_D9_D10,
544   AArch64::D9_D10_D11,  AArch64::D10_D11_D12, AArch64::D11_D12_D13,
545   AArch64::D12_D13_D14, AArch64::D13_D14_D15, AArch64::D14_D15_D16,
546   AArch64::D15_D16_D17, AArch64::D16_D17_D18, AArch64::D17_D18_D19,
547   AArch64::D18_D19_D20, AArch64::D19_D20_D21, AArch64::D20_D21_D22,
548   AArch64::D21_D22_D23, AArch64::D22_D23_D24, AArch64::D23_D24_D25,
549   AArch64::D24_D25_D26, AArch64::D25_D26_D27, AArch64::D26_D27_D28,
550   AArch64::D27_D28_D29, AArch64::D28_D29_D30, AArch64::D29_D30_D31,
551   AArch64::D30_D31_D0,  AArch64::D31_D0_D1
552 };
553 
554 static DecodeStatus DecodeDDDRegisterClass(MCInst &Inst, unsigned RegNo,
555                                            uint64_t Addr, const void *Decoder) {
556   if (RegNo > 31)
557     return Fail;
558   unsigned Register = DDDDecoderTable[RegNo];
559   Inst.addOperand(MCOperand::CreateReg(Register));
560   return Success;
561 }
562 
563 static const unsigned DDDDDecoderTable[] = {
564   AArch64::D0_D1_D2_D3,     AArch64::D1_D2_D3_D4,     AArch64::D2_D3_D4_D5,
565   AArch64::D3_D4_D5_D6,     AArch64::D4_D5_D6_D7,     AArch64::D5_D6_D7_D8,
566   AArch64::D6_D7_D8_D9,     AArch64::D7_D8_D9_D10,    AArch64::D8_D9_D10_D11,
567   AArch64::D9_D10_D11_D12,  AArch64::D10_D11_D12_D13, AArch64::D11_D12_D13_D14,
568   AArch64::D12_D13_D14_D15, AArch64::D13_D14_D15_D16, AArch64::D14_D15_D16_D17,
569   AArch64::D15_D16_D17_D18, AArch64::D16_D17_D18_D19, AArch64::D17_D18_D19_D20,
570   AArch64::D18_D19_D20_D21, AArch64::D19_D20_D21_D22, AArch64::D20_D21_D22_D23,
571   AArch64::D21_D22_D23_D24, AArch64::D22_D23_D24_D25, AArch64::D23_D24_D25_D26,
572   AArch64::D24_D25_D26_D27, AArch64::D25_D26_D27_D28, AArch64::D26_D27_D28_D29,
573   AArch64::D27_D28_D29_D30, AArch64::D28_D29_D30_D31, AArch64::D29_D30_D31_D0,
574   AArch64::D30_D31_D0_D1,   AArch64::D31_D0_D1_D2
575 };
576 
577 static DecodeStatus DecodeDDDDRegisterClass(MCInst &Inst, unsigned RegNo,
578                                             uint64_t Addr,
579                                             const void *Decoder) {
580   if (RegNo > 31)
581     return Fail;
582   unsigned Register = DDDDDecoderTable[RegNo];
583   Inst.addOperand(MCOperand::CreateReg(Register));
584   return Success;
585 }
586 
587 static DecodeStatus DecodeFixedPointScaleImm32(llvm::MCInst &Inst, unsigned Imm,
588                                                uint64_t Addr,
589                                                const void *Decoder) {
590   // scale{5} is asserted as 1 in tblgen.
591   Imm |= 0x20;
592   Inst.addOperand(MCOperand::CreateImm(64 - Imm));
593   return Success;
594 }
595 
596 static DecodeStatus DecodeFixedPointScaleImm64(llvm::MCInst &Inst, unsigned Imm,
597                                                uint64_t Addr,
598                                                const void *Decoder) {
599   Inst.addOperand(MCOperand::CreateImm(64 - Imm));
600   return Success;
601 }
602 
603 static DecodeStatus DecodePCRelLabel19(llvm::MCInst &Inst, unsigned Imm,
604                                        uint64_t Addr, const void *Decoder) {
605   int64_t ImmVal = Imm;
606   const AArch64Disassembler *Dis =
607       static_cast<const AArch64Disassembler *>(Decoder);
608 
609   // Sign-extend 19-bit immediate.
610   if (ImmVal & (1 << (19 - 1)))
611     ImmVal |= ~((1LL << 19) - 1);
612 
613   if (!Dis->tryAddingSymbolicOperand(Inst, ImmVal *  4, Addr,
614                                      Inst.getOpcode() != AArch64::LDRXl, 0, 4))
615     Inst.addOperand(MCOperand::CreateImm(ImmVal));
616   return Success;
617 }
618 
619 static DecodeStatus DecodeMemExtend(llvm::MCInst &Inst, unsigned Imm,
620                                     uint64_t Address, const void *Decoder) {
621   Inst.addOperand(MCOperand::CreateImm((Imm  >> 1) & 1));
622   Inst.addOperand(MCOperand::CreateImm(Imm & 1));
623   return Success;
624 }
625 
626 static DecodeStatus DecodeMRSSystemRegister(llvm::MCInst &Inst, unsigned Imm,
627                                             uint64_t Address,
628                                             const void *Decoder) {
629   Inst.addOperand(MCOperand::CreateImm(Imm));
630 
631   // Every system register in the encoding space is valid with the syntax
632   // S<op0>_<op1>_<Cn>_<Cm>_<op2>, so decoding system registers always succeeds.
633   return Success;
634 }
635 
636 static DecodeStatus DecodeMSRSystemRegister(llvm::MCInst &Inst, unsigned Imm,
637                                             uint64_t Address,
638                                             const void *Decoder) {
639   Inst.addOperand(MCOperand::CreateImm(Imm));
640 
641   return Success;
642 }
643 
644 static DecodeStatus DecodeFMOVLaneInstruction(llvm::MCInst &Inst, unsigned Insn,
645                                               uint64_t Address,
646                                               const void *Decoder) {
647   // This decoder exists to add the dummy Lane operand to the MCInst, which must
648   // be 1 in assembly but has no other real manifestation.
649   unsigned Rd = fieldFromInstruction(Insn, 0, 5);
650   unsigned Rn = fieldFromInstruction(Insn, 5, 5);
651   unsigned IsToVec = fieldFromInstruction(Insn, 16, 1);
652 
653   if (IsToVec) {
654     DecodeFPR128RegisterClass(Inst, Rd, Address, Decoder);
655     DecodeGPR64RegisterClass(Inst, Rn, Address, Decoder);
656   } else {
657     DecodeGPR64RegisterClass(Inst, Rd, Address, Decoder);
658     DecodeFPR128RegisterClass(Inst, Rn, Address, Decoder);
659   }
660 
661   // Add the lane
662   Inst.addOperand(MCOperand::CreateImm(1));
663 
664   return Success;
665 }
666 
667 static DecodeStatus DecodeVecShiftRImm(llvm::MCInst &Inst, unsigned Imm,
668                                        unsigned Add) {
669   Inst.addOperand(MCOperand::CreateImm(Add - Imm));
670   return Success;
671 }
672 
673 static DecodeStatus DecodeVecShiftLImm(llvm::MCInst &Inst, unsigned Imm,
674                                        unsigned Add) {
675   Inst.addOperand(MCOperand::CreateImm((Imm + Add) & (Add - 1)));
676   return Success;
677 }
678 
679 static DecodeStatus DecodeVecShiftR64Imm(llvm::MCInst &Inst, unsigned Imm,
680                                          uint64_t Addr, const void *Decoder) {
681   return DecodeVecShiftRImm(Inst, Imm, 64);
682 }
683 
684 static DecodeStatus DecodeVecShiftR64ImmNarrow(llvm::MCInst &Inst, unsigned Imm,
685                                                uint64_t Addr,
686                                                const void *Decoder) {
687   return DecodeVecShiftRImm(Inst, Imm | 0x20, 64);
688 }
689 
690 static DecodeStatus DecodeVecShiftR32Imm(llvm::MCInst &Inst, unsigned Imm,
691                                          uint64_t Addr, const void *Decoder) {
692   return DecodeVecShiftRImm(Inst, Imm, 32);
693 }
694 
695 static DecodeStatus DecodeVecShiftR32ImmNarrow(llvm::MCInst &Inst, unsigned Imm,
696                                                uint64_t Addr,
697                                                const void *Decoder) {
698   return DecodeVecShiftRImm(Inst, Imm | 0x10, 32);
699 }
700 
701 static DecodeStatus DecodeVecShiftR16Imm(llvm::MCInst &Inst, unsigned Imm,
702                                          uint64_t Addr, const void *Decoder) {
703   return DecodeVecShiftRImm(Inst, Imm, 16);
704 }
705 
706 static DecodeStatus DecodeVecShiftR16ImmNarrow(llvm::MCInst &Inst, unsigned Imm,
707                                                uint64_t Addr,
708                                                const void *Decoder) {
709   return DecodeVecShiftRImm(Inst, Imm | 0x8, 16);
710 }
711 
712 static DecodeStatus DecodeVecShiftR8Imm(llvm::MCInst &Inst, unsigned Imm,
713                                         uint64_t Addr, const void *Decoder) {
714   return DecodeVecShiftRImm(Inst, Imm, 8);
715 }
716 
717 static DecodeStatus DecodeVecShiftL64Imm(llvm::MCInst &Inst, unsigned Imm,
718                                          uint64_t Addr, const void *Decoder) {
719   return DecodeVecShiftLImm(Inst, Imm, 64);
720 }
721 
722 static DecodeStatus DecodeVecShiftL32Imm(llvm::MCInst &Inst, unsigned Imm,
723                                          uint64_t Addr, const void *Decoder) {
724   return DecodeVecShiftLImm(Inst, Imm, 32);
725 }
726 
727 static DecodeStatus DecodeVecShiftL16Imm(llvm::MCInst &Inst, unsigned Imm,
728                                          uint64_t Addr, const void *Decoder) {
729   return DecodeVecShiftLImm(Inst, Imm, 16);
730 }
731 
732 static DecodeStatus DecodeVecShiftL8Imm(llvm::MCInst &Inst, unsigned Imm,
733                                         uint64_t Addr, const void *Decoder) {
734   return DecodeVecShiftLImm(Inst, Imm, 8);
735 }
736 
737 static DecodeStatus DecodeThreeAddrSRegInstruction(llvm::MCInst &Inst,
738                                                    uint32_t insn, uint64_t Addr,
739                                                    const void *Decoder) {
740   unsigned Rd = fieldFromInstruction(insn, 0, 5);
741   unsigned Rn = fieldFromInstruction(insn, 5, 5);
742   unsigned Rm = fieldFromInstruction(insn, 16, 5);
743   unsigned shiftHi = fieldFromInstruction(insn, 22, 2);
744   unsigned shiftLo = fieldFromInstruction(insn, 10, 6);
745   unsigned shift = (shiftHi << 6) | shiftLo;
746   switch (Inst.getOpcode()) {
747   default:
748     return Fail;
749   case AArch64::ADDWrs:
750   case AArch64::ADDSWrs:
751   case AArch64::SUBWrs:
752   case AArch64::SUBSWrs:
753     // if shift == '11' then ReservedValue()
754     if (shiftHi == 0x3)
755       return Fail;
756     // Deliberate fallthrough
757   case AArch64::ANDWrs:
758   case AArch64::ANDSWrs:
759   case AArch64::BICWrs:
760   case AArch64::BICSWrs:
761   case AArch64::ORRWrs:
762   case AArch64::ORNWrs:
763   case AArch64::EORWrs:
764   case AArch64::EONWrs: {
765     // if sf == '0' and imm6<5> == '1' then ReservedValue()
766     if (shiftLo >> 5 == 1)
767       return Fail;
768     DecodeGPR32RegisterClass(Inst, Rd, Addr, Decoder);
769     DecodeGPR32RegisterClass(Inst, Rn, Addr, Decoder);
770     DecodeGPR32RegisterClass(Inst, Rm, Addr, Decoder);
771     break;
772   }
773   case AArch64::ADDXrs:
774   case AArch64::ADDSXrs:
775   case AArch64::SUBXrs:
776   case AArch64::SUBSXrs:
777     // if shift == '11' then ReservedValue()
778     if (shiftHi == 0x3)
779       return Fail;
780     // Deliberate fallthrough
781   case AArch64::ANDXrs:
782   case AArch64::ANDSXrs:
783   case AArch64::BICXrs:
784   case AArch64::BICSXrs:
785   case AArch64::ORRXrs:
786   case AArch64::ORNXrs:
787   case AArch64::EORXrs:
788   case AArch64::EONXrs:
789     DecodeGPR64RegisterClass(Inst, Rd, Addr, Decoder);
790     DecodeGPR64RegisterClass(Inst, Rn, Addr, Decoder);
791     DecodeGPR64RegisterClass(Inst, Rm, Addr, Decoder);
792     break;
793   }
794 
795   Inst.addOperand(MCOperand::CreateImm(shift));
796   return Success;
797 }
798 
799 static DecodeStatus DecodeMoveImmInstruction(llvm::MCInst &Inst, uint32_t insn,
800                                              uint64_t Addr,
801                                              const void *Decoder) {
802   unsigned Rd = fieldFromInstruction(insn, 0, 5);
803   unsigned imm = fieldFromInstruction(insn, 5, 16);
804   unsigned shift = fieldFromInstruction(insn, 21, 2);
805   shift <<= 4;
806   switch (Inst.getOpcode()) {
807   default:
808     return Fail;
809   case AArch64::MOVZWi:
810   case AArch64::MOVNWi:
811   case AArch64::MOVKWi:
812     if (shift & (1U << 5))
813       return Fail;
814     DecodeGPR32RegisterClass(Inst, Rd, Addr, Decoder);
815     break;
816   case AArch64::MOVZXi:
817   case AArch64::MOVNXi:
818   case AArch64::MOVKXi:
819     DecodeGPR64RegisterClass(Inst, Rd, Addr, Decoder);
820     break;
821   }
822 
823   if (Inst.getOpcode() == AArch64::MOVKWi ||
824       Inst.getOpcode() == AArch64::MOVKXi)
825     Inst.addOperand(Inst.getOperand(0));
826 
827   Inst.addOperand(MCOperand::CreateImm(imm));
828   Inst.addOperand(MCOperand::CreateImm(shift));
829   return Success;
830 }
831 
832 static DecodeStatus DecodeUnsignedLdStInstruction(llvm::MCInst &Inst,
833                                                   uint32_t insn, uint64_t Addr,
834                                                   const void *Decoder) {
835   unsigned Rt = fieldFromInstruction(insn, 0, 5);
836   unsigned Rn = fieldFromInstruction(insn, 5, 5);
837   unsigned offset = fieldFromInstruction(insn, 10, 12);
838   const AArch64Disassembler *Dis =
839       static_cast<const AArch64Disassembler *>(Decoder);
840 
841   switch (Inst.getOpcode()) {
842   default:
843     return Fail;
844   case AArch64::PRFMui:
845     // Rt is an immediate in prefetch.
846     Inst.addOperand(MCOperand::CreateImm(Rt));
847     break;
848   case AArch64::STRBBui:
849   case AArch64::LDRBBui:
850   case AArch64::LDRSBWui:
851   case AArch64::STRHHui:
852   case AArch64::LDRHHui:
853   case AArch64::LDRSHWui:
854   case AArch64::STRWui:
855   case AArch64::LDRWui:
856     DecodeGPR32RegisterClass(Inst, Rt, Addr, Decoder);
857     break;
858   case AArch64::LDRSBXui:
859   case AArch64::LDRSHXui:
860   case AArch64::LDRSWui:
861   case AArch64::STRXui:
862   case AArch64::LDRXui:
863     DecodeGPR64RegisterClass(Inst, Rt, Addr, Decoder);
864     break;
865   case AArch64::LDRQui:
866   case AArch64::STRQui:
867     DecodeFPR128RegisterClass(Inst, Rt, Addr, Decoder);
868     break;
869   case AArch64::LDRDui:
870   case AArch64::STRDui:
871     DecodeFPR64RegisterClass(Inst, Rt, Addr, Decoder);
872     break;
873   case AArch64::LDRSui:
874   case AArch64::STRSui:
875     DecodeFPR32RegisterClass(Inst, Rt, Addr, Decoder);
876     break;
877   case AArch64::LDRHui:
878   case AArch64::STRHui:
879     DecodeFPR16RegisterClass(Inst, Rt, Addr, Decoder);
880     break;
881   case AArch64::LDRBui:
882   case AArch64::STRBui:
883     DecodeFPR8RegisterClass(Inst, Rt, Addr, Decoder);
884     break;
885   }
886 
887   DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);
888   if (!Dis->tryAddingSymbolicOperand(Inst, offset, Addr, Fail, 0, 4))
889     Inst.addOperand(MCOperand::CreateImm(offset));
890   return Success;
891 }
892 
893 static DecodeStatus DecodeSignedLdStInstruction(llvm::MCInst &Inst,
894                                                 uint32_t insn, uint64_t Addr,
895                                                 const void *Decoder) {
896   unsigned Rt = fieldFromInstruction(insn, 0, 5);
897   unsigned Rn = fieldFromInstruction(insn, 5, 5);
898   int64_t offset = fieldFromInstruction(insn, 12, 9);
899 
900   // offset is a 9-bit signed immediate, so sign extend it to
901   // fill the unsigned.
902   if (offset & (1 << (9 - 1)))
903     offset |= ~((1LL << 9) - 1);
904 
905   // First operand is always the writeback to the address register, if needed.
906   switch (Inst.getOpcode()) {
907   default:
908     break;
909   case AArch64::LDRSBWpre:
910   case AArch64::LDRSHWpre:
911   case AArch64::STRBBpre:
912   case AArch64::LDRBBpre:
913   case AArch64::STRHHpre:
914   case AArch64::LDRHHpre:
915   case AArch64::STRWpre:
916   case AArch64::LDRWpre:
917   case AArch64::LDRSBWpost:
918   case AArch64::LDRSHWpost:
919   case AArch64::STRBBpost:
920   case AArch64::LDRBBpost:
921   case AArch64::STRHHpost:
922   case AArch64::LDRHHpost:
923   case AArch64::STRWpost:
924   case AArch64::LDRWpost:
925   case AArch64::LDRSBXpre:
926   case AArch64::LDRSHXpre:
927   case AArch64::STRXpre:
928   case AArch64::LDRSWpre:
929   case AArch64::LDRXpre:
930   case AArch64::LDRSBXpost:
931   case AArch64::LDRSHXpost:
932   case AArch64::STRXpost:
933   case AArch64::LDRSWpost:
934   case AArch64::LDRXpost:
935   case AArch64::LDRQpre:
936   case AArch64::STRQpre:
937   case AArch64::LDRQpost:
938   case AArch64::STRQpost:
939   case AArch64::LDRDpre:
940   case AArch64::STRDpre:
941   case AArch64::LDRDpost:
942   case AArch64::STRDpost:
943   case AArch64::LDRSpre:
944   case AArch64::STRSpre:
945   case AArch64::LDRSpost:
946   case AArch64::STRSpost:
947   case AArch64::LDRHpre:
948   case AArch64::STRHpre:
949   case AArch64::LDRHpost:
950   case AArch64::STRHpost:
951   case AArch64::LDRBpre:
952   case AArch64::STRBpre:
953   case AArch64::LDRBpost:
954   case AArch64::STRBpost:
955     DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);
956     break;
957   }
958 
959   switch (Inst.getOpcode()) {
960   default:
961     return Fail;
962   case AArch64::PRFUMi:
963     // Rt is an immediate in prefetch.
964     Inst.addOperand(MCOperand::CreateImm(Rt));
965     break;
966   case AArch64::STURBBi:
967   case AArch64::LDURBBi:
968   case AArch64::LDURSBWi:
969   case AArch64::STURHHi:
970   case AArch64::LDURHHi:
971   case AArch64::LDURSHWi:
972   case AArch64::STURWi:
973   case AArch64::LDURWi:
974   case AArch64::LDTRSBWi:
975   case AArch64::LDTRSHWi:
976   case AArch64::STTRWi:
977   case AArch64::LDTRWi:
978   case AArch64::STTRHi:
979   case AArch64::LDTRHi:
980   case AArch64::LDTRBi:
981   case AArch64::STTRBi:
982   case AArch64::LDRSBWpre:
983   case AArch64::LDRSHWpre:
984   case AArch64::STRBBpre:
985   case AArch64::LDRBBpre:
986   case AArch64::STRHHpre:
987   case AArch64::LDRHHpre:
988   case AArch64::STRWpre:
989   case AArch64::LDRWpre:
990   case AArch64::LDRSBWpost:
991   case AArch64::LDRSHWpost:
992   case AArch64::STRBBpost:
993   case AArch64::LDRBBpost:
994   case AArch64::STRHHpost:
995   case AArch64::LDRHHpost:
996   case AArch64::STRWpost:
997   case AArch64::LDRWpost:
998     DecodeGPR32RegisterClass(Inst, Rt, Addr, Decoder);
999     break;
1000   case AArch64::LDURSBXi:
1001   case AArch64::LDURSHXi:
1002   case AArch64::LDURSWi:
1003   case AArch64::STURXi:
1004   case AArch64::LDURXi:
1005   case AArch64::LDTRSBXi:
1006   case AArch64::LDTRSHXi:
1007   case AArch64::LDTRSWi:
1008   case AArch64::STTRXi:
1009   case AArch64::LDTRXi:
1010   case AArch64::LDRSBXpre:
1011   case AArch64::LDRSHXpre:
1012   case AArch64::STRXpre:
1013   case AArch64::LDRSWpre:
1014   case AArch64::LDRXpre:
1015   case AArch64::LDRSBXpost:
1016   case AArch64::LDRSHXpost:
1017   case AArch64::STRXpost:
1018   case AArch64::LDRSWpost:
1019   case AArch64::LDRXpost:
1020     DecodeGPR64RegisterClass(Inst, Rt, Addr, Decoder);
1021     break;
1022   case AArch64::LDURQi:
1023   case AArch64::STURQi:
1024   case AArch64::LDRQpre:
1025   case AArch64::STRQpre:
1026   case AArch64::LDRQpost:
1027   case AArch64::STRQpost:
1028     DecodeFPR128RegisterClass(Inst, Rt, Addr, Decoder);
1029     break;
1030   case AArch64::LDURDi:
1031   case AArch64::STURDi:
1032   case AArch64::LDRDpre:
1033   case AArch64::STRDpre:
1034   case AArch64::LDRDpost:
1035   case AArch64::STRDpost:
1036     DecodeFPR64RegisterClass(Inst, Rt, Addr, Decoder);
1037     break;
1038   case AArch64::LDURSi:
1039   case AArch64::STURSi:
1040   case AArch64::LDRSpre:
1041   case AArch64::STRSpre:
1042   case AArch64::LDRSpost:
1043   case AArch64::STRSpost:
1044     DecodeFPR32RegisterClass(Inst, Rt, Addr, Decoder);
1045     break;
1046   case AArch64::LDURHi:
1047   case AArch64::STURHi:
1048   case AArch64::LDRHpre:
1049   case AArch64::STRHpre:
1050   case AArch64::LDRHpost:
1051   case AArch64::STRHpost:
1052     DecodeFPR16RegisterClass(Inst, Rt, Addr, Decoder);
1053     break;
1054   case AArch64::LDURBi:
1055   case AArch64::STURBi:
1056   case AArch64::LDRBpre:
1057   case AArch64::STRBpre:
1058   case AArch64::LDRBpost:
1059   case AArch64::STRBpost:
1060     DecodeFPR8RegisterClass(Inst, Rt, Addr, Decoder);
1061     break;
1062   }
1063 
1064   DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);
1065   Inst.addOperand(MCOperand::CreateImm(offset));
1066 
1067   bool IsLoad = fieldFromInstruction(insn, 22, 1);
1068   bool IsIndexed = fieldFromInstruction(insn, 10, 2) != 0;
1069   bool IsFP = fieldFromInstruction(insn, 26, 1);
1070 
1071   // Cannot write back to a transfer register (but xzr != sp).
1072   if (IsLoad && IsIndexed && !IsFP && Rn != 31 && Rt == Rn)
1073     return SoftFail;
1074 
1075   return Success;
1076 }
1077 
1078 static DecodeStatus DecodeExclusiveLdStInstruction(llvm::MCInst &Inst,
1079                                                    uint32_t insn, uint64_t Addr,
1080                                                    const void *Decoder) {
1081   unsigned Rt = fieldFromInstruction(insn, 0, 5);
1082   unsigned Rn = fieldFromInstruction(insn, 5, 5);
1083   unsigned Rt2 = fieldFromInstruction(insn, 10, 5);
1084   unsigned Rs = fieldFromInstruction(insn, 16, 5);
1085 
1086   unsigned Opcode = Inst.getOpcode();
1087   switch (Opcode) {
1088   default:
1089     return Fail;
1090   case AArch64::STLXRW:
1091   case AArch64::STLXRB:
1092   case AArch64::STLXRH:
1093   case AArch64::STXRW:
1094   case AArch64::STXRB:
1095   case AArch64::STXRH:
1096     DecodeGPR32RegisterClass(Inst, Rs, Addr, Decoder);
1097   // FALLTHROUGH
1098   case AArch64::LDARW:
1099   case AArch64::LDARB:
1100   case AArch64::LDARH:
1101   case AArch64::LDAXRW:
1102   case AArch64::LDAXRB:
1103   case AArch64::LDAXRH:
1104   case AArch64::LDXRW:
1105   case AArch64::LDXRB:
1106   case AArch64::LDXRH:
1107   case AArch64::STLRW:
1108   case AArch64::STLRB:
1109   case AArch64::STLRH:
1110     DecodeGPR32RegisterClass(Inst, Rt, Addr, Decoder);
1111     break;
1112   case AArch64::STLXRX:
1113   case AArch64::STXRX:
1114     DecodeGPR32RegisterClass(Inst, Rs, Addr, Decoder);
1115   // FALLTHROUGH
1116   case AArch64::LDARX:
1117   case AArch64::LDAXRX:
1118   case AArch64::LDXRX:
1119   case AArch64::STLRX:
1120     DecodeGPR64RegisterClass(Inst, Rt, Addr, Decoder);
1121     break;
1122   case AArch64::STLXPW:
1123   case AArch64::STXPW:
1124     DecodeGPR32RegisterClass(Inst, Rs, Addr, Decoder);
1125   // FALLTHROUGH
1126   case AArch64::LDAXPW:
1127   case AArch64::LDXPW:
1128     DecodeGPR32RegisterClass(Inst, Rt, Addr, Decoder);
1129     DecodeGPR32RegisterClass(Inst, Rt2, Addr, Decoder);
1130     break;
1131   case AArch64::STLXPX:
1132   case AArch64::STXPX:
1133     DecodeGPR32RegisterClass(Inst, Rs, Addr, Decoder);
1134   // FALLTHROUGH
1135   case AArch64::LDAXPX:
1136   case AArch64::LDXPX:
1137     DecodeGPR64RegisterClass(Inst, Rt, Addr, Decoder);
1138     DecodeGPR64RegisterClass(Inst, Rt2, Addr, Decoder);
1139     break;
1140   }
1141 
1142   DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);
1143 
1144   // You shouldn't load to the same register twice in an instruction...
1145   if ((Opcode == AArch64::LDAXPW || Opcode == AArch64::LDXPW ||
1146        Opcode == AArch64::LDAXPX || Opcode == AArch64::LDXPX) &&
1147       Rt == Rt2)
1148     return SoftFail;
1149 
1150   return Success;
1151 }
1152 
1153 static DecodeStatus DecodePairLdStInstruction(llvm::MCInst &Inst, uint32_t insn,
1154                                               uint64_t Addr,
1155                                               const void *Decoder) {
1156   unsigned Rt = fieldFromInstruction(insn, 0, 5);
1157   unsigned Rn = fieldFromInstruction(insn, 5, 5);
1158   unsigned Rt2 = fieldFromInstruction(insn, 10, 5);
1159   int64_t offset = fieldFromInstruction(insn, 15, 7);
1160   bool IsLoad = fieldFromInstruction(insn, 22, 1);
1161 
1162   // offset is a 7-bit signed immediate, so sign extend it to
1163   // fill the unsigned.
1164   if (offset & (1 << (7 - 1)))
1165     offset |= ~((1LL << 7) - 1);
1166 
1167   unsigned Opcode = Inst.getOpcode();
1168   bool NeedsDisjointWritebackTransfer = false;
1169 
1170   // First operand is always writeback of base register.
1171   switch (Opcode) {
1172   default:
1173     break;
1174   case AArch64::LDPXpost:
1175   case AArch64::STPXpost:
1176   case AArch64::LDPSWpost:
1177   case AArch64::LDPXpre:
1178   case AArch64::STPXpre:
1179   case AArch64::LDPSWpre:
1180   case AArch64::LDPWpost:
1181   case AArch64::STPWpost:
1182   case AArch64::LDPWpre:
1183   case AArch64::STPWpre:
1184   case AArch64::LDPQpost:
1185   case AArch64::STPQpost:
1186   case AArch64::LDPQpre:
1187   case AArch64::STPQpre:
1188   case AArch64::LDPDpost:
1189   case AArch64::STPDpost:
1190   case AArch64::LDPDpre:
1191   case AArch64::STPDpre:
1192   case AArch64::LDPSpost:
1193   case AArch64::STPSpost:
1194   case AArch64::LDPSpre:
1195   case AArch64::STPSpre:
1196     DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);
1197     break;
1198   }
1199 
1200   switch (Opcode) {
1201   default:
1202     return Fail;
1203   case AArch64::LDPXpost:
1204   case AArch64::STPXpost:
1205   case AArch64::LDPSWpost:
1206   case AArch64::LDPXpre:
1207   case AArch64::STPXpre:
1208   case AArch64::LDPSWpre:
1209     NeedsDisjointWritebackTransfer = true;
1210     // Fallthrough
1211   case AArch64::LDNPXi:
1212   case AArch64::STNPXi:
1213   case AArch64::LDPXi:
1214   case AArch64::STPXi:
1215   case AArch64::LDPSWi:
1216     DecodeGPR64RegisterClass(Inst, Rt, Addr, Decoder);
1217     DecodeGPR64RegisterClass(Inst, Rt2, Addr, Decoder);
1218     break;
1219   case AArch64::LDPWpost:
1220   case AArch64::STPWpost:
1221   case AArch64::LDPWpre:
1222   case AArch64::STPWpre:
1223     NeedsDisjointWritebackTransfer = true;
1224     // Fallthrough
1225   case AArch64::LDNPWi:
1226   case AArch64::STNPWi:
1227   case AArch64::LDPWi:
1228   case AArch64::STPWi:
1229     DecodeGPR32RegisterClass(Inst, Rt, Addr, Decoder);
1230     DecodeGPR32RegisterClass(Inst, Rt2, Addr, Decoder);
1231     break;
1232   case AArch64::LDNPQi:
1233   case AArch64::STNPQi:
1234   case AArch64::LDPQpost:
1235   case AArch64::STPQpost:
1236   case AArch64::LDPQi:
1237   case AArch64::STPQi:
1238   case AArch64::LDPQpre:
1239   case AArch64::STPQpre:
1240     DecodeFPR128RegisterClass(Inst, Rt, Addr, Decoder);
1241     DecodeFPR128RegisterClass(Inst, Rt2, Addr, Decoder);
1242     break;
1243   case AArch64::LDNPDi:
1244   case AArch64::STNPDi:
1245   case AArch64::LDPDpost:
1246   case AArch64::STPDpost:
1247   case AArch64::LDPDi:
1248   case AArch64::STPDi:
1249   case AArch64::LDPDpre:
1250   case AArch64::STPDpre:
1251     DecodeFPR64RegisterClass(Inst, Rt, Addr, Decoder);
1252     DecodeFPR64RegisterClass(Inst, Rt2, Addr, Decoder);
1253     break;
1254   case AArch64::LDNPSi:
1255   case AArch64::STNPSi:
1256   case AArch64::LDPSpost:
1257   case AArch64::STPSpost:
1258   case AArch64::LDPSi:
1259   case AArch64::STPSi:
1260   case AArch64::LDPSpre:
1261   case AArch64::STPSpre:
1262     DecodeFPR32RegisterClass(Inst, Rt, Addr, Decoder);
1263     DecodeFPR32RegisterClass(Inst, Rt2, Addr, Decoder);
1264     break;
1265   }
1266 
1267   DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);
1268   Inst.addOperand(MCOperand::CreateImm(offset));
1269 
1270   // You shouldn't load to the same register twice in an instruction...
1271   if (IsLoad && Rt == Rt2)
1272     return SoftFail;
1273 
1274   // ... or do any operation that writes-back to a transfer register. But note
1275   // that "stp xzr, xzr, [sp], #4" is fine because xzr and sp are different.
1276   if (NeedsDisjointWritebackTransfer && Rn != 31 && (Rt == Rn || Rt2 == Rn))
1277     return SoftFail;
1278 
1279   return Success;
1280 }
1281 
1282 static DecodeStatus DecodeAddSubERegInstruction(llvm::MCInst &Inst,
1283                                                 uint32_t insn, uint64_t Addr,
1284                                                 const void *Decoder) {
1285   unsigned Rd = fieldFromInstruction(insn, 0, 5);
1286   unsigned Rn = fieldFromInstruction(insn, 5, 5);
1287   unsigned Rm = fieldFromInstruction(insn, 16, 5);
1288   unsigned extend = fieldFromInstruction(insn, 10, 6);
1289 
1290   unsigned shift = extend & 0x7;
1291   if (shift > 4)
1292     return Fail;
1293 
1294   switch (Inst.getOpcode()) {
1295   default:
1296     return Fail;
1297   case AArch64::ADDWrx:
1298   case AArch64::SUBWrx:
1299     DecodeGPR32spRegisterClass(Inst, Rd, Addr, Decoder);
1300     DecodeGPR32spRegisterClass(Inst, Rn, Addr, Decoder);
1301     DecodeGPR32RegisterClass(Inst, Rm, Addr, Decoder);
1302     break;
1303   case AArch64::ADDSWrx:
1304   case AArch64::SUBSWrx:
1305     DecodeGPR32RegisterClass(Inst, Rd, Addr, Decoder);
1306     DecodeGPR32spRegisterClass(Inst, Rn, Addr, Decoder);
1307     DecodeGPR32RegisterClass(Inst, Rm, Addr, Decoder);
1308     break;
1309   case AArch64::ADDXrx:
1310   case AArch64::SUBXrx:
1311     DecodeGPR64spRegisterClass(Inst, Rd, Addr, Decoder);
1312     DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);
1313     DecodeGPR32RegisterClass(Inst, Rm, Addr, Decoder);
1314     break;
1315   case AArch64::ADDSXrx:
1316   case AArch64::SUBSXrx:
1317     DecodeGPR64RegisterClass(Inst, Rd, Addr, Decoder);
1318     DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);
1319     DecodeGPR32RegisterClass(Inst, Rm, Addr, Decoder);
1320     break;
1321   case AArch64::ADDXrx64:
1322   case AArch64::SUBXrx64:
1323     DecodeGPR64spRegisterClass(Inst, Rd, Addr, Decoder);
1324     DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);
1325     DecodeGPR64RegisterClass(Inst, Rm, Addr, Decoder);
1326     break;
1327   case AArch64::SUBSXrx64:
1328   case AArch64::ADDSXrx64:
1329     DecodeGPR64RegisterClass(Inst, Rd, Addr, Decoder);
1330     DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);
1331     DecodeGPR64RegisterClass(Inst, Rm, Addr, Decoder);
1332     break;
1333   }
1334 
1335   Inst.addOperand(MCOperand::CreateImm(extend));
1336   return Success;
1337 }
1338 
1339 static DecodeStatus DecodeLogicalImmInstruction(llvm::MCInst &Inst,
1340                                                 uint32_t insn, uint64_t Addr,
1341                                                 const void *Decoder) {
1342   unsigned Rd = fieldFromInstruction(insn, 0, 5);
1343   unsigned Rn = fieldFromInstruction(insn, 5, 5);
1344   unsigned Datasize = fieldFromInstruction(insn, 31, 1);
1345   unsigned imm;
1346 
1347   if (Datasize) {
1348     if (Inst.getOpcode() == AArch64::ANDSXri)
1349       DecodeGPR64RegisterClass(Inst, Rd, Addr, Decoder);
1350     else
1351       DecodeGPR64spRegisterClass(Inst, Rd, Addr, Decoder);
1352     DecodeGPR64RegisterClass(Inst, Rn, Addr, Decoder);
1353     imm = fieldFromInstruction(insn, 10, 13);
1354     if (!AArch64_AM::isValidDecodeLogicalImmediate(imm, 64))
1355       return Fail;
1356   } else {
1357     if (Inst.getOpcode() == AArch64::ANDSWri)
1358       DecodeGPR32RegisterClass(Inst, Rd, Addr, Decoder);
1359     else
1360       DecodeGPR32spRegisterClass(Inst, Rd, Addr, Decoder);
1361     DecodeGPR32RegisterClass(Inst, Rn, Addr, Decoder);
1362     imm = fieldFromInstruction(insn, 10, 12);
1363     if (!AArch64_AM::isValidDecodeLogicalImmediate(imm, 32))
1364       return Fail;
1365   }
1366   Inst.addOperand(MCOperand::CreateImm(imm));
1367   return Success;
1368 }
1369 
1370 static DecodeStatus DecodeModImmInstruction(llvm::MCInst &Inst, uint32_t insn,
1371                                             uint64_t Addr,
1372                                             const void *Decoder) {
1373   unsigned Rd = fieldFromInstruction(insn, 0, 5);
1374   unsigned cmode = fieldFromInstruction(insn, 12, 4);
1375   unsigned imm = fieldFromInstruction(insn, 16, 3) << 5;
1376   imm |= fieldFromInstruction(insn, 5, 5);
1377 
1378   if (Inst.getOpcode() == AArch64::MOVID)
1379     DecodeFPR64RegisterClass(Inst, Rd, Addr, Decoder);
1380   else
1381     DecodeVectorRegisterClass(Inst, Rd, Addr, Decoder);
1382 
1383   Inst.addOperand(MCOperand::CreateImm(imm));
1384 
1385   switch (Inst.getOpcode()) {
1386   default:
1387     break;
1388   case AArch64::MOVIv4i16:
1389   case AArch64::MOVIv8i16:
1390   case AArch64::MVNIv4i16:
1391   case AArch64::MVNIv8i16:
1392   case AArch64::MOVIv2i32:
1393   case AArch64::MOVIv4i32:
1394   case AArch64::MVNIv2i32:
1395   case AArch64::MVNIv4i32:
1396     Inst.addOperand(MCOperand::CreateImm((cmode & 6) << 2));
1397     break;
1398   case AArch64::MOVIv2s_msl:
1399   case AArch64::MOVIv4s_msl:
1400   case AArch64::MVNIv2s_msl:
1401   case AArch64::MVNIv4s_msl:
1402     Inst.addOperand(MCOperand::CreateImm(cmode & 1 ? 0x110 : 0x108));
1403     break;
1404   }
1405 
1406   return Success;
1407 }
1408 
1409 static DecodeStatus DecodeModImmTiedInstruction(llvm::MCInst &Inst,
1410                                                 uint32_t insn, uint64_t Addr,
1411                                                 const void *Decoder) {
1412   unsigned Rd = fieldFromInstruction(insn, 0, 5);
1413   unsigned cmode = fieldFromInstruction(insn, 12, 4);
1414   unsigned imm = fieldFromInstruction(insn, 16, 3) << 5;
1415   imm |= fieldFromInstruction(insn, 5, 5);
1416 
1417   // Tied operands added twice.
1418   DecodeVectorRegisterClass(Inst, Rd, Addr, Decoder);
1419   DecodeVectorRegisterClass(Inst, Rd, Addr, Decoder);
1420 
1421   Inst.addOperand(MCOperand::CreateImm(imm));
1422   Inst.addOperand(MCOperand::CreateImm((cmode & 6) << 2));
1423 
1424   return Success;
1425 }
1426 
1427 static DecodeStatus DecodeAdrInstruction(llvm::MCInst &Inst, uint32_t insn,
1428                                          uint64_t Addr, const void *Decoder) {
1429   unsigned Rd = fieldFromInstruction(insn, 0, 5);
1430   int64_t imm = fieldFromInstruction(insn, 5, 19) << 2;
1431   imm |= fieldFromInstruction(insn, 29, 2);
1432   const AArch64Disassembler *Dis =
1433       static_cast<const AArch64Disassembler *>(Decoder);
1434 
1435   // Sign-extend the 21-bit immediate.
1436   if (imm & (1 << (21 - 1)))
1437     imm |= ~((1LL << 21) - 1);
1438 
1439   DecodeGPR64RegisterClass(Inst, Rd, Addr, Decoder);
1440   if (!Dis->tryAddingSymbolicOperand(Inst, imm, Addr, Fail, 0, 4))
1441     Inst.addOperand(MCOperand::CreateImm(imm));
1442 
1443   return Success;
1444 }
1445 
1446 static DecodeStatus DecodeBaseAddSubImm(llvm::MCInst &Inst, uint32_t insn,
1447                                         uint64_t Addr, const void *Decoder) {
1448   unsigned Rd = fieldFromInstruction(insn, 0, 5);
1449   unsigned Rn = fieldFromInstruction(insn, 5, 5);
1450   unsigned Imm = fieldFromInstruction(insn, 10, 14);
1451   unsigned S = fieldFromInstruction(insn, 29, 1);
1452   unsigned Datasize = fieldFromInstruction(insn, 31, 1);
1453 
1454   unsigned ShifterVal = (Imm >> 12) & 3;
1455   unsigned ImmVal = Imm & 0xFFF;
1456   const AArch64Disassembler *Dis =
1457       static_cast<const AArch64Disassembler *>(Decoder);
1458 
1459   if (ShifterVal != 0 && ShifterVal != 1)
1460     return Fail;
1461 
1462   if (Datasize) {
1463     if (Rd == 31 && !S)
1464       DecodeGPR64spRegisterClass(Inst, Rd, Addr, Decoder);
1465     else
1466       DecodeGPR64RegisterClass(Inst, Rd, Addr, Decoder);
1467     DecodeGPR64spRegisterClass(Inst, Rn, Addr, Decoder);
1468   } else {
1469     if (Rd == 31 && !S)
1470       DecodeGPR32spRegisterClass(Inst, Rd, Addr, Decoder);
1471     else
1472       DecodeGPR32RegisterClass(Inst, Rd, Addr, Decoder);
1473     DecodeGPR32spRegisterClass(Inst, Rn, Addr, Decoder);
1474   }
1475 
1476   if (!Dis->tryAddingSymbolicOperand(Inst, Imm, Addr, Fail, 0, 4))
1477     Inst.addOperand(MCOperand::CreateImm(ImmVal));
1478   Inst.addOperand(MCOperand::CreateImm(12 * ShifterVal));
1479   return Success;
1480 }
1481 
1482 static DecodeStatus DecodeUnconditionalBranch(llvm::MCInst &Inst, uint32_t insn,
1483                                               uint64_t Addr,
1484                                               const void *Decoder) {
1485   int64_t imm = fieldFromInstruction(insn, 0, 26);
1486   const AArch64Disassembler *Dis =
1487       static_cast<const AArch64Disassembler *>(Decoder);
1488 
1489   // Sign-extend the 26-bit immediate.
1490   if (imm & (1 << (26 - 1)))
1491     imm |= ~((1LL << 26) - 1);
1492 
1493   if (!Dis->tryAddingSymbolicOperand(Inst, imm * 4, Addr, true, 0, 4))
1494     Inst.addOperand(MCOperand::CreateImm(imm));
1495 
1496   return Success;
1497 }
1498 
1499 static DecodeStatus DecodeSystemPStateInstruction(llvm::MCInst &Inst,
1500                                                   uint32_t insn, uint64_t Addr,
1501                                                   const void *Decoder) {
1502   uint64_t op1 = fieldFromInstruction(insn, 16, 3);
1503   uint64_t op2 = fieldFromInstruction(insn, 5, 3);
1504   uint64_t crm = fieldFromInstruction(insn, 8, 4);
1505 
1506   uint64_t pstate_field = (op1 << 3) | op2;
1507 
1508   Inst.addOperand(MCOperand::CreateImm(pstate_field));
1509   Inst.addOperand(MCOperand::CreateImm(crm));
1510 
1511   bool ValidNamed;
1512   (void)AArch64PState::PStateMapper().toString(pstate_field, ValidNamed);
1513 
1514   return ValidNamed ? Success : Fail;
1515 }
1516 
1517 static DecodeStatus DecodeTestAndBranch(llvm::MCInst &Inst, uint32_t insn,
1518                                         uint64_t Addr, const void *Decoder) {
1519   uint64_t Rt = fieldFromInstruction(insn, 0, 5);
1520   uint64_t bit = fieldFromInstruction(insn, 31, 1) << 5;
1521   bit |= fieldFromInstruction(insn, 19, 5);
1522   int64_t dst = fieldFromInstruction(insn, 5, 14);
1523   const AArch64Disassembler *Dis =
1524       static_cast<const AArch64Disassembler *>(Decoder);
1525 
1526   // Sign-extend 14-bit immediate.
1527   if (dst & (1 << (14 - 1)))
1528     dst |= ~((1LL << 14) - 1);
1529 
1530   if (fieldFromInstruction(insn, 31, 1) == 0)
1531     DecodeGPR32RegisterClass(Inst, Rt, Addr, Decoder);
1532   else
1533     DecodeGPR64RegisterClass(Inst, Rt, Addr, Decoder);
1534   Inst.addOperand(MCOperand::CreateImm(bit));
1535   if (!Dis->tryAddingSymbolicOperand(Inst, dst * 4, Addr, true, 0, 4))
1536     Inst.addOperand(MCOperand::CreateImm(dst));
1537 
1538   return Success;
1539 }
1540