1 //===- ARMDisassembler.cpp - Disassembler for ARM/Thumb ISA ---------------===//
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 #include "ARMBaseInstrInfo.h"
10 #include "MCTargetDesc/ARMAddressingModes.h"
11 #include "MCTargetDesc/ARMBaseInfo.h"
12 #include "MCTargetDesc/ARMMCTargetDesc.h"
13 #include "TargetInfo/ARMTargetInfo.h"
14 #include "Utils/ARMBaseInfo.h"
15 #include "llvm/MC/MCContext.h"
16 #include "llvm/MC/MCDecoderOps.h"
17 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
18 #include "llvm/MC/MCInst.h"
19 #include "llvm/MC/MCInstrDesc.h"
20 #include "llvm/MC/MCSubtargetInfo.h"
21 #include "llvm/MC/SubtargetFeature.h"
22 #include "llvm/MC/TargetRegistry.h"
23 #include "llvm/Support/Compiler.h"
24 #include "llvm/Support/ErrorHandling.h"
25 #include "llvm/Support/MathExtras.h"
26 #include "llvm/Support/raw_ostream.h"
27 #include <algorithm>
28 #include <cassert>
29 #include <cstdint>
30 #include <vector>
31 
32 using namespace llvm;
33 
34 #define DEBUG_TYPE "arm-disassembler"
35 
36 using DecodeStatus = MCDisassembler::DecodeStatus;
37 
38 namespace {
39 
40   // Handles the condition code status of instructions in IT blocks
41   class ITStatus
42   {
43     public:
44       // Returns the condition code for instruction in IT block
45       unsigned getITCC() {
46         unsigned CC = ARMCC::AL;
47         if (instrInITBlock())
48           CC = ITStates.back();
49         return CC;
50       }
51 
52       // Advances the IT block state to the next T or E
53       void advanceITState() {
54         ITStates.pop_back();
55       }
56 
57       // Returns true if the current instruction is in an IT block
58       bool instrInITBlock() {
59         return !ITStates.empty();
60       }
61 
62       // Returns true if current instruction is the last instruction in an IT block
63       bool instrLastInITBlock() {
64         return ITStates.size() == 1;
65       }
66 
67       // Called when decoding an IT instruction. Sets the IT state for
68       // the following instructions that for the IT block. Firstcond
69       // corresponds to the field in the IT instruction encoding; Mask
70       // is in the MCOperand format in which 1 means 'else' and 0 'then'.
71       void setITState(char Firstcond, char Mask) {
72         // (3 - the number of trailing zeros) is the number of then / else.
73         unsigned NumTZ = countTrailingZeros<uint8_t>(Mask);
74         unsigned char CCBits = static_cast<unsigned char>(Firstcond & 0xf);
75         assert(NumTZ <= 3 && "Invalid IT mask!");
76         // push condition codes onto the stack the correct order for the pops
77         for (unsigned Pos = NumTZ+1; Pos <= 3; ++Pos) {
78           unsigned Else = (Mask >> Pos) & 1;
79           ITStates.push_back(CCBits ^ Else);
80         }
81         ITStates.push_back(CCBits);
82       }
83 
84     private:
85       std::vector<unsigned char> ITStates;
86   };
87 
88   class VPTStatus
89   {
90     public:
91       unsigned getVPTPred() {
92         unsigned Pred = ARMVCC::None;
93         if (instrInVPTBlock())
94           Pred = VPTStates.back();
95         return Pred;
96       }
97 
98       void advanceVPTState() {
99         VPTStates.pop_back();
100       }
101 
102       bool instrInVPTBlock() {
103         return !VPTStates.empty();
104       }
105 
106       bool instrLastInVPTBlock() {
107         return VPTStates.size() == 1;
108       }
109 
110       void setVPTState(char Mask) {
111         // (3 - the number of trailing zeros) is the number of then / else.
112         unsigned NumTZ = countTrailingZeros<uint8_t>(Mask);
113         assert(NumTZ <= 3 && "Invalid VPT mask!");
114         // push predicates onto the stack the correct order for the pops
115         for (unsigned Pos = NumTZ+1; Pos <= 3; ++Pos) {
116           bool T = ((Mask >> Pos) & 1) == 0;
117           if (T)
118             VPTStates.push_back(ARMVCC::Then);
119           else
120             VPTStates.push_back(ARMVCC::Else);
121         }
122         VPTStates.push_back(ARMVCC::Then);
123       }
124 
125     private:
126       SmallVector<unsigned char, 4> VPTStates;
127   };
128 
129 /// ARM disassembler for all ARM platforms.
130 class ARMDisassembler : public MCDisassembler {
131 public:
132   ARMDisassembler(const MCSubtargetInfo &STI, MCContext &Ctx) :
133     MCDisassembler(STI, Ctx) {
134   }
135 
136   ~ARMDisassembler() override = default;
137 
138   DecodeStatus getInstruction(MCInst &Instr, uint64_t &Size,
139                               ArrayRef<uint8_t> Bytes, uint64_t Address,
140                               raw_ostream &CStream) const override;
141 
142   uint64_t suggestBytesToSkip(ArrayRef<uint8_t> Bytes,
143                               uint64_t Address) const override;
144 
145 private:
146   DecodeStatus getARMInstruction(MCInst &Instr, uint64_t &Size,
147                                  ArrayRef<uint8_t> Bytes, uint64_t Address,
148                                  raw_ostream &CStream) const;
149 
150   DecodeStatus getThumbInstruction(MCInst &Instr, uint64_t &Size,
151                                    ArrayRef<uint8_t> Bytes, uint64_t Address,
152                                    raw_ostream &CStream) const;
153 
154   mutable ITStatus ITBlock;
155   mutable VPTStatus VPTBlock;
156 
157   DecodeStatus AddThumbPredicate(MCInst&) const;
158   void UpdateThumbVFPPredicate(DecodeStatus &, MCInst&) const;
159 };
160 
161 } // end anonymous namespace
162 
163 static bool Check(DecodeStatus &Out, DecodeStatus In) {
164   switch (In) {
165     case MCDisassembler::Success:
166       // Out stays the same.
167       return true;
168     case MCDisassembler::SoftFail:
169       Out = In;
170       return true;
171     case MCDisassembler::Fail:
172       Out = In;
173       return false;
174   }
175   llvm_unreachable("Invalid DecodeStatus!");
176 }
177 
178 // Forward declare these because the autogenerated code will reference them.
179 // Definitions are further down.
180 static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, unsigned RegNo,
181                                            uint64_t Address,
182                                            const MCDisassembler *Decoder);
183 static DecodeStatus DecodeCLRMGPRRegisterClass(MCInst &Inst, unsigned RegNo,
184                                                uint64_t Address,
185                                                const MCDisassembler *Decoder);
186 static DecodeStatus DecodetGPROddRegisterClass(MCInst &Inst, unsigned RegNo,
187                                                uint64_t Address,
188                                                const MCDisassembler *Decoder);
189 static DecodeStatus DecodetGPREvenRegisterClass(MCInst &Inst, unsigned RegNo,
190                                                 uint64_t Address,
191                                                 const MCDisassembler *Decoder);
192 static DecodeStatus
193 DecodeGPRwithAPSR_NZCVnospRegisterClass(MCInst &Inst, unsigned RegNo,
194                                         uint64_t Address,
195                                         const MCDisassembler *Decoder);
196 static DecodeStatus DecodeGPRnopcRegisterClass(MCInst &Inst, unsigned RegNo,
197                                                uint64_t Address,
198                                                const MCDisassembler *Decoder);
199 static DecodeStatus DecodeGPRnospRegisterClass(MCInst &Inst, unsigned RegNo,
200                                                uint64_t Address,
201                                                const MCDisassembler *Decoder);
202 static DecodeStatus
203 DecodeGPRwithAPSRRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Address,
204                                const MCDisassembler *Decoder);
205 static DecodeStatus DecodeGPRwithZRRegisterClass(MCInst &Inst, unsigned RegNo,
206                                                  uint64_t Address,
207                                                  const MCDisassembler *Decoder);
208 static DecodeStatus
209 DecodeGPRwithZRnospRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Address,
210                                  const MCDisassembler *Decoder);
211 static DecodeStatus DecodetGPRRegisterClass(MCInst &Inst, unsigned RegNo,
212                                             uint64_t Address,
213                                             const MCDisassembler *Decoder);
214 static DecodeStatus DecodetcGPRRegisterClass(MCInst &Inst, unsigned RegNo,
215                                              uint64_t Address,
216                                              const MCDisassembler *Decoder);
217 static DecodeStatus DecoderGPRRegisterClass(MCInst &Inst, unsigned RegNo,
218                                             uint64_t Address,
219                                             const MCDisassembler *Decoder);
220 static DecodeStatus DecodeGPRPairRegisterClass(MCInst &Inst, unsigned RegNo,
221                                                uint64_t Address,
222                                                const MCDisassembler *Decoder);
223 static DecodeStatus
224 DecodeGPRPairnospRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Address,
225                                const MCDisassembler *Decoder);
226 static DecodeStatus DecodeGPRspRegisterClass(MCInst &Inst, unsigned RegNo,
227                                              uint64_t Address,
228                                              const MCDisassembler *Decoder);
229 static DecodeStatus DecodeHPRRegisterClass(MCInst &Inst, unsigned RegNo,
230                                            uint64_t Address,
231                                            const MCDisassembler *Decoder);
232 static DecodeStatus DecodeSPRRegisterClass(MCInst &Inst, unsigned RegNo,
233                                            uint64_t Address,
234                                            const MCDisassembler *Decoder);
235 static DecodeStatus DecodeDPRRegisterClass(MCInst &Inst, unsigned RegNo,
236                                            uint64_t Address,
237                                            const MCDisassembler *Decoder);
238 static DecodeStatus DecodeDPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
239                                              uint64_t Address,
240                                              const MCDisassembler *Decoder);
241 static DecodeStatus DecodeSPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
242                                              uint64_t Address,
243                                              const MCDisassembler *Decoder);
244 static DecodeStatus DecodeDPR_VFP2RegisterClass(MCInst &Inst, unsigned RegNo,
245                                                 uint64_t Address,
246                                                 const MCDisassembler *Decoder);
247 static DecodeStatus DecodeQPRRegisterClass(MCInst &Inst, unsigned RegNo,
248                                            uint64_t Address,
249                                            const MCDisassembler *Decoder);
250 static DecodeStatus DecodeMQPRRegisterClass(MCInst &Inst, unsigned RegNo,
251                                             uint64_t Address,
252                                             const MCDisassembler *Decoder);
253 static DecodeStatus DecodeMQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
254                                              uint64_t Address,
255                                              const MCDisassembler *Decoder);
256 static DecodeStatus DecodeMQQQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
257                                                uint64_t Address,
258                                                const MCDisassembler *Decoder);
259 static DecodeStatus DecodeDPairRegisterClass(MCInst &Inst, unsigned RegNo,
260                                              uint64_t Address,
261                                              const MCDisassembler *Decoder);
262 static DecodeStatus
263 DecodeDPairSpacedRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Address,
264                                const MCDisassembler *Decoder);
265 
266 static DecodeStatus DecodePredicateOperand(MCInst &Inst, unsigned Val,
267                                            uint64_t Address,
268                                            const MCDisassembler *Decoder);
269 static DecodeStatus DecodeCCOutOperand(MCInst &Inst, unsigned Val,
270                                        uint64_t Address,
271                                        const MCDisassembler *Decoder);
272 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Val,
273                                          uint64_t Address,
274                                          const MCDisassembler *Decoder);
275 static DecodeStatus DecodeSPRRegListOperand(MCInst &Inst, unsigned Val,
276                                             uint64_t Address,
277                                             const MCDisassembler *Decoder);
278 static DecodeStatus DecodeDPRRegListOperand(MCInst &Inst, unsigned Val,
279                                             uint64_t Address,
280                                             const MCDisassembler *Decoder);
281 
282 static DecodeStatus DecodeBitfieldMaskOperand(MCInst &Inst, unsigned Insn,
283                                               uint64_t Address,
284                                               const MCDisassembler *Decoder);
285 static DecodeStatus DecodeCopMemInstruction(MCInst &Inst, unsigned Insn,
286                                             uint64_t Address,
287                                             const MCDisassembler *Decoder);
288 static DecodeStatus
289 DecodeAddrMode2IdxInstruction(MCInst &Inst, unsigned Insn, uint64_t Address,
290                               const MCDisassembler *Decoder);
291 static DecodeStatus DecodeSORegMemOperand(MCInst &Inst, unsigned Insn,
292                                           uint64_t Address,
293                                           const MCDisassembler *Decoder);
294 static DecodeStatus DecodeAddrMode3Instruction(MCInst &Inst, unsigned Insn,
295                                                uint64_t Address,
296                                                const MCDisassembler *Decoder);
297 static DecodeStatus DecodeTSBInstruction(MCInst &Inst, unsigned Insn,
298                                          uint64_t Address,
299                                          const MCDisassembler *Decoder);
300 static DecodeStatus DecodeSORegImmOperand(MCInst &Inst, unsigned Insn,
301                                           uint64_t Address,
302                                           const MCDisassembler *Decoder);
303 static DecodeStatus DecodeSORegRegOperand(MCInst &Inst, unsigned Insn,
304                                           uint64_t Address,
305                                           const MCDisassembler *Decoder);
306 
307 static DecodeStatus
308 DecodeMemMultipleWritebackInstruction(MCInst &Inst, unsigned Insn,
309                                       uint64_t Adddress,
310                                       const MCDisassembler *Decoder);
311 static DecodeStatus DecodeT2MOVTWInstruction(MCInst &Inst, unsigned Insn,
312                                              uint64_t Address,
313                                              const MCDisassembler *Decoder);
314 static DecodeStatus DecodeArmMOVTWInstruction(MCInst &Inst, unsigned Insn,
315                                               uint64_t Address,
316                                               const MCDisassembler *Decoder);
317 static DecodeStatus DecodeSMLAInstruction(MCInst &Inst, unsigned Insn,
318                                           uint64_t Address,
319                                           const MCDisassembler *Decoder);
320 static DecodeStatus DecodeHINTInstruction(MCInst &Inst, unsigned Insn,
321                                           uint64_t Address,
322                                           const MCDisassembler *Decoder);
323 static DecodeStatus DecodeCPSInstruction(MCInst &Inst, unsigned Insn,
324                                          uint64_t Address,
325                                          const MCDisassembler *Decoder);
326 static DecodeStatus DecodeTSTInstruction(MCInst &Inst, unsigned Insn,
327                                          uint64_t Address,
328                                          const MCDisassembler *Decoder);
329 static DecodeStatus DecodeSETPANInstruction(MCInst &Inst, unsigned Insn,
330                                             uint64_t Address,
331                                             const MCDisassembler *Decoder);
332 static DecodeStatus DecodeT2CPSInstruction(MCInst &Inst, unsigned Insn,
333                                            uint64_t Address,
334                                            const MCDisassembler *Decoder);
335 static DecodeStatus DecodeT2HintSpaceInstruction(MCInst &Inst, unsigned Insn,
336                                                  uint64_t Address,
337                                                  const MCDisassembler *Decoder);
338 static DecodeStatus DecodeAddrModeImm12Operand(MCInst &Inst, unsigned Val,
339                                                uint64_t Address,
340                                                const MCDisassembler *Decoder);
341 static DecodeStatus DecodeAddrMode5Operand(MCInst &Inst, unsigned Val,
342                                            uint64_t Address,
343                                            const MCDisassembler *Decoder);
344 static DecodeStatus DecodeAddrMode5FP16Operand(MCInst &Inst, unsigned Val,
345                                                uint64_t Address,
346                                                const MCDisassembler *Decoder);
347 static DecodeStatus DecodeAddrMode7Operand(MCInst &Inst, unsigned Val,
348                                            uint64_t Address,
349                                            const MCDisassembler *Decoder);
350 static DecodeStatus DecodeT2BInstruction(MCInst &Inst, unsigned Insn,
351                                          uint64_t Address,
352                                          const MCDisassembler *Decoder);
353 static DecodeStatus DecodeBranchImmInstruction(MCInst &Inst, unsigned Insn,
354                                                uint64_t Address,
355                                                const MCDisassembler *Decoder);
356 static DecodeStatus DecodeAddrMode6Operand(MCInst &Inst, unsigned Val,
357                                            uint64_t Address,
358                                            const MCDisassembler *Decoder);
359 static DecodeStatus DecodeVLDST1Instruction(MCInst &Inst, unsigned Val,
360                                             uint64_t Address,
361                                             const MCDisassembler *Decoder);
362 static DecodeStatus DecodeVLDST2Instruction(MCInst &Inst, unsigned Val,
363                                             uint64_t Address,
364                                             const MCDisassembler *Decoder);
365 static DecodeStatus DecodeVLDST3Instruction(MCInst &Inst, unsigned Val,
366                                             uint64_t Address,
367                                             const MCDisassembler *Decoder);
368 static DecodeStatus DecodeVLDST4Instruction(MCInst &Inst, unsigned Val,
369                                             uint64_t Address,
370                                             const MCDisassembler *Decoder);
371 static DecodeStatus DecodeVLDInstruction(MCInst &Inst, unsigned Val,
372                                          uint64_t Address,
373                                          const MCDisassembler *Decoder);
374 static DecodeStatus DecodeVSTInstruction(MCInst &Inst, unsigned Val,
375                                          uint64_t Address,
376                                          const MCDisassembler *Decoder);
377 static DecodeStatus DecodeVLD1DupInstruction(MCInst &Inst, unsigned Val,
378                                              uint64_t Address,
379                                              const MCDisassembler *Decoder);
380 static DecodeStatus DecodeVLD2DupInstruction(MCInst &Inst, unsigned Val,
381                                              uint64_t Address,
382                                              const MCDisassembler *Decoder);
383 static DecodeStatus DecodeVLD3DupInstruction(MCInst &Inst, unsigned Val,
384                                              uint64_t Address,
385                                              const MCDisassembler *Decoder);
386 static DecodeStatus DecodeVLD4DupInstruction(MCInst &Inst, unsigned Val,
387                                              uint64_t Address,
388                                              const MCDisassembler *Decoder);
389 static DecodeStatus DecodeVMOVModImmInstruction(MCInst &Inst, unsigned Val,
390                                                 uint64_t Address,
391                                                 const MCDisassembler *Decoder);
392 static DecodeStatus DecodeMVEModImmInstruction(MCInst &Inst, unsigned Val,
393                                                uint64_t Address,
394                                                const MCDisassembler *Decoder);
395 static DecodeStatus DecodeMVEVADCInstruction(MCInst &Inst, unsigned Insn,
396                                              uint64_t Address,
397                                              const MCDisassembler *Decoder);
398 static DecodeStatus DecodeVSHLMaxInstruction(MCInst &Inst, unsigned Val,
399                                              uint64_t Address,
400                                              const MCDisassembler *Decoder);
401 static DecodeStatus DecodeShiftRight8Imm(MCInst &Inst, unsigned Val,
402                                          uint64_t Address,
403                                          const MCDisassembler *Decoder);
404 static DecodeStatus DecodeShiftRight16Imm(MCInst &Inst, unsigned Val,
405                                           uint64_t Address,
406                                           const MCDisassembler *Decoder);
407 static DecodeStatus DecodeShiftRight32Imm(MCInst &Inst, unsigned Val,
408                                           uint64_t Address,
409                                           const MCDisassembler *Decoder);
410 static DecodeStatus DecodeShiftRight64Imm(MCInst &Inst, unsigned Val,
411                                           uint64_t Address,
412                                           const MCDisassembler *Decoder);
413 static DecodeStatus DecodeTBLInstruction(MCInst &Inst, unsigned Insn,
414                                          uint64_t Address,
415                                          const MCDisassembler *Decoder);
416 static DecodeStatus DecodePostIdxReg(MCInst &Inst, unsigned Insn,
417                                      uint64_t Address,
418                                      const MCDisassembler *Decoder);
419 static DecodeStatus DecodeMveAddrModeRQ(MCInst &Inst, unsigned Insn,
420                                         uint64_t Address,
421                                         const MCDisassembler *Decoder);
422 template <int shift>
423 static DecodeStatus DecodeMveAddrModeQ(MCInst &Inst, unsigned Insn,
424                                        uint64_t Address,
425                                        const MCDisassembler *Decoder);
426 static DecodeStatus DecodeCoprocessor(MCInst &Inst, unsigned Insn,
427                                       uint64_t Address,
428                                       const MCDisassembler *Decoder);
429 static DecodeStatus DecodeMemBarrierOption(MCInst &Inst, unsigned Insn,
430                                            uint64_t Address,
431                                            const MCDisassembler *Decoder);
432 static DecodeStatus DecodeInstSyncBarrierOption(MCInst &Inst, unsigned Insn,
433                                                 uint64_t Address,
434                                                 const MCDisassembler *Decoder);
435 static DecodeStatus DecodeMSRMask(MCInst &Inst, unsigned Insn, uint64_t Address,
436                                   const MCDisassembler *Decoder);
437 static DecodeStatus DecodeBankedReg(MCInst &Inst, unsigned Insn,
438                                     uint64_t Address,
439                                     const MCDisassembler *Decoder);
440 static DecodeStatus DecodeDoubleRegLoad(MCInst &Inst, unsigned Insn,
441                                         uint64_t Address,
442                                         const MCDisassembler *Decoder);
443 static DecodeStatus DecodeDoubleRegStore(MCInst &Inst, unsigned Insn,
444                                          uint64_t Address,
445                                          const MCDisassembler *Decoder);
446 static DecodeStatus DecodeLDRPreImm(MCInst &Inst, unsigned Insn,
447                                     uint64_t Address,
448                                     const MCDisassembler *Decoder);
449 static DecodeStatus DecodeLDRPreReg(MCInst &Inst, unsigned Insn,
450                                     uint64_t Address,
451                                     const MCDisassembler *Decoder);
452 static DecodeStatus DecodeSTRPreImm(MCInst &Inst, unsigned Insn,
453                                     uint64_t Address,
454                                     const MCDisassembler *Decoder);
455 static DecodeStatus DecodeSTRPreReg(MCInst &Inst, unsigned Insn,
456                                     uint64_t Address,
457                                     const MCDisassembler *Decoder);
458 static DecodeStatus DecodeVLD1LN(MCInst &Inst, unsigned Insn, uint64_t Address,
459                                  const MCDisassembler *Decoder);
460 static DecodeStatus DecodeVLD2LN(MCInst &Inst, unsigned Insn, uint64_t Address,
461                                  const MCDisassembler *Decoder);
462 static DecodeStatus DecodeVLD3LN(MCInst &Inst, unsigned Insn, uint64_t Address,
463                                  const MCDisassembler *Decoder);
464 static DecodeStatus DecodeVLD4LN(MCInst &Inst, unsigned Insn, uint64_t Address,
465                                  const MCDisassembler *Decoder);
466 static DecodeStatus DecodeVST1LN(MCInst &Inst, unsigned Insn, uint64_t Address,
467                                  const MCDisassembler *Decoder);
468 static DecodeStatus DecodeVST2LN(MCInst &Inst, unsigned Insn, uint64_t Address,
469                                  const MCDisassembler *Decoder);
470 static DecodeStatus DecodeVST3LN(MCInst &Inst, unsigned Insn, uint64_t Address,
471                                  const MCDisassembler *Decoder);
472 static DecodeStatus DecodeVST4LN(MCInst &Inst, unsigned Insn, uint64_t Address,
473                                  const MCDisassembler *Decoder);
474 static DecodeStatus DecodeVMOVSRR(MCInst &Inst, unsigned Insn, uint64_t Address,
475                                   const MCDisassembler *Decoder);
476 static DecodeStatus DecodeVMOVRRS(MCInst &Inst, unsigned Insn, uint64_t Address,
477                                   const MCDisassembler *Decoder);
478 static DecodeStatus DecodeSwap(MCInst &Inst, unsigned Insn, uint64_t Address,
479                                const MCDisassembler *Decoder);
480 static DecodeStatus DecodeVCVTD(MCInst &Inst, unsigned Insn, uint64_t Address,
481                                 const MCDisassembler *Decoder);
482 static DecodeStatus DecodeVCVTQ(MCInst &Inst, unsigned Insn, uint64_t Address,
483                                 const MCDisassembler *Decoder);
484 static DecodeStatus DecodeVCVTImmOperand(MCInst &Inst, unsigned Insn,
485                                          uint64_t Address,
486                                          const MCDisassembler *Decoder);
487 static DecodeStatus
488 DecodeNEONComplexLane64Instruction(MCInst &Inst, unsigned Val, uint64_t Address,
489                                    const MCDisassembler *Decoder);
490 
491 static DecodeStatus DecodeThumbAddSpecialReg(MCInst &Inst, uint16_t Insn,
492                                              uint64_t Address,
493                                              const MCDisassembler *Decoder);
494 static DecodeStatus DecodeThumbBROperand(MCInst &Inst, unsigned Val,
495                                          uint64_t Address,
496                                          const MCDisassembler *Decoder);
497 static DecodeStatus DecodeT2BROperand(MCInst &Inst, unsigned Val,
498                                       uint64_t Address,
499                                       const MCDisassembler *Decoder);
500 static DecodeStatus DecodeThumbCmpBROperand(MCInst &Inst, unsigned Val,
501                                             uint64_t Address,
502                                             const MCDisassembler *Decoder);
503 static DecodeStatus DecodeThumbAddrModeRR(MCInst &Inst, unsigned Val,
504                                           uint64_t Address,
505                                           const MCDisassembler *Decoder);
506 static DecodeStatus DecodeThumbAddrModeIS(MCInst &Inst, unsigned Val,
507                                           uint64_t Address,
508                                           const MCDisassembler *Decoder);
509 static DecodeStatus DecodeThumbAddrModePC(MCInst &Inst, unsigned Val,
510                                           uint64_t Address,
511                                           const MCDisassembler *Decoder);
512 static DecodeStatus DecodeThumbAddrModeSP(MCInst &Inst, unsigned Val,
513                                           uint64_t Address,
514                                           const MCDisassembler *Decoder);
515 static DecodeStatus DecodeT2AddrModeSOReg(MCInst &Inst, unsigned Val,
516                                           uint64_t Address,
517                                           const MCDisassembler *Decoder);
518 static DecodeStatus DecodeT2LoadShift(MCInst &Inst, unsigned Val,
519                                       uint64_t Address,
520                                       const MCDisassembler *Decoder);
521 static DecodeStatus DecodeT2LoadImm8(MCInst &Inst, unsigned Insn,
522                                      uint64_t Address,
523                                      const MCDisassembler *Decoder);
524 static DecodeStatus DecodeT2LoadImm12(MCInst &Inst, unsigned Insn,
525                                       uint64_t Address,
526                                       const MCDisassembler *Decoder);
527 static DecodeStatus DecodeT2LoadT(MCInst &Inst, unsigned Insn, uint64_t Address,
528                                   const MCDisassembler *Decoder);
529 static DecodeStatus DecodeT2LoadLabel(MCInst &Inst, unsigned Insn,
530                                       uint64_t Address,
531                                       const MCDisassembler *Decoder);
532 static DecodeStatus DecodeT2Imm8S4(MCInst &Inst, unsigned Val, uint64_t Address,
533                                    const MCDisassembler *Decoder);
534 static DecodeStatus DecodeT2Imm7S4(MCInst &Inst, unsigned Val, uint64_t Address,
535                                    const MCDisassembler *Decoder);
536 static DecodeStatus DecodeT2AddrModeImm8s4(MCInst &Inst, unsigned Val,
537                                            uint64_t Address,
538                                            const MCDisassembler *Decoder);
539 static DecodeStatus DecodeT2AddrModeImm7s4(MCInst &Inst, unsigned Val,
540                                            uint64_t Address,
541                                            const MCDisassembler *Decoder);
542 static DecodeStatus DecodeT2AddrModeImm0_1020s4(MCInst &Inst, unsigned Val,
543                                                 uint64_t Address,
544                                                 const MCDisassembler *Decoder);
545 static DecodeStatus DecodeT2Imm8(MCInst &Inst, unsigned Val, uint64_t Address,
546                                  const MCDisassembler *Decoder);
547 template <int shift>
548 static DecodeStatus DecodeT2Imm7(MCInst &Inst, unsigned Val, uint64_t Address,
549                                  const MCDisassembler *Decoder);
550 static DecodeStatus DecodeT2AddrModeImm8(MCInst &Inst, unsigned Val,
551                                          uint64_t Address,
552                                          const MCDisassembler *Decoder);
553 template <int shift>
554 static DecodeStatus DecodeTAddrModeImm7(MCInst &Inst, unsigned Val,
555                                         uint64_t Address,
556                                         const MCDisassembler *Decoder);
557 template <int shift, int WriteBack>
558 static DecodeStatus DecodeT2AddrModeImm7(MCInst &Inst, unsigned Val,
559                                          uint64_t Address,
560                                          const MCDisassembler *Decoder);
561 static DecodeStatus DecodeThumbAddSPImm(MCInst &Inst, uint16_t Val,
562                                         uint64_t Address,
563                                         const MCDisassembler *Decoder);
564 static DecodeStatus DecodeThumbAddSPReg(MCInst &Inst, uint16_t Insn,
565                                         uint64_t Address,
566                                         const MCDisassembler *Decoder);
567 static DecodeStatus DecodeThumbCPS(MCInst &Inst, uint16_t Insn,
568                                    uint64_t Address,
569                                    const MCDisassembler *Decoder);
570 static DecodeStatus DecodeQADDInstruction(MCInst &Inst, unsigned Insn,
571                                           uint64_t Address,
572                                           const MCDisassembler *Decoder);
573 static DecodeStatus DecodeThumbBLXOffset(MCInst &Inst, unsigned Insn,
574                                          uint64_t Address,
575                                          const MCDisassembler *Decoder);
576 static DecodeStatus DecodeT2AddrModeImm12(MCInst &Inst, unsigned Val,
577                                           uint64_t Address,
578                                           const MCDisassembler *Decoder);
579 static DecodeStatus DecodeThumbTableBranch(MCInst &Inst, unsigned Val,
580                                            uint64_t Address,
581                                            const MCDisassembler *Decoder);
582 static DecodeStatus DecodeThumb2BCCInstruction(MCInst &Inst, unsigned Val,
583                                                uint64_t Address,
584                                                const MCDisassembler *Decoder);
585 static DecodeStatus DecodeT2SOImm(MCInst &Inst, unsigned Val, uint64_t Address,
586                                   const MCDisassembler *Decoder);
587 static DecodeStatus DecodeThumbBCCTargetOperand(MCInst &Inst, unsigned Val,
588                                                 uint64_t Address,
589                                                 const MCDisassembler *Decoder);
590 static DecodeStatus DecodeThumbBLTargetOperand(MCInst &Inst, unsigned Val,
591                                                uint64_t Address,
592                                                const MCDisassembler *Decoder);
593 static DecodeStatus DecodeIT(MCInst &Inst, unsigned Val, uint64_t Address,
594                              const MCDisassembler *Decoder);
595 static DecodeStatus DecodeT2LDRDPreInstruction(MCInst &Inst, unsigned Insn,
596                                                uint64_t Address,
597                                                const MCDisassembler *Decoder);
598 static DecodeStatus DecodeT2STRDPreInstruction(MCInst &Inst, unsigned Insn,
599                                                uint64_t Address,
600                                                const MCDisassembler *Decoder);
601 static DecodeStatus DecodeT2Adr(MCInst &Inst, unsigned Val, uint64_t Address,
602                                 const MCDisassembler *Decoder);
603 static DecodeStatus DecodeT2LdStPre(MCInst &Inst, unsigned Val,
604                                     uint64_t Address,
605                                     const MCDisassembler *Decoder);
606 static DecodeStatus DecodeT2ShifterImmOperand(MCInst &Inst, unsigned Val,
607                                               uint64_t Address,
608                                               const MCDisassembler *Decoder);
609 
610 static DecodeStatus DecodeLDR(MCInst &Inst, unsigned Val, uint64_t Address,
611                               const MCDisassembler *Decoder);
612 static DecodeStatus DecoderForMRRC2AndMCRR2(MCInst &Inst, unsigned Val,
613                                             uint64_t Address,
614                                             const MCDisassembler *Decoder);
615 static DecodeStatus DecodeForVMRSandVMSR(MCInst &Inst, unsigned Val,
616                                          uint64_t Address,
617                                          const MCDisassembler *Decoder);
618 
619 template <bool isSigned, bool isNeg, bool zeroPermitted, int size>
620 static DecodeStatus DecodeBFLabelOperand(MCInst &Inst, unsigned val,
621                                          uint64_t Address,
622                                          const MCDisassembler *Decoder);
623 static DecodeStatus DecodeBFAfterTargetOperand(MCInst &Inst, unsigned val,
624                                                uint64_t Address,
625                                                const MCDisassembler *Decoder);
626 static DecodeStatus DecodePredNoALOperand(MCInst &Inst, unsigned Val,
627                                           uint64_t Address,
628                                           const MCDisassembler *Decoder);
629 static DecodeStatus DecodeLOLoop(MCInst &Inst, unsigned Insn, uint64_t Address,
630                                  const MCDisassembler *Decoder);
631 static DecodeStatus DecodeLongShiftOperand(MCInst &Inst, unsigned Val,
632                                            uint64_t Address,
633                                            const MCDisassembler *Decoder);
634 static DecodeStatus DecodeVSCCLRM(MCInst &Inst, unsigned Insn, uint64_t Address,
635                                   const MCDisassembler *Decoder);
636 static DecodeStatus DecodeVPTMaskOperand(MCInst &Inst, unsigned Val,
637                                          uint64_t Address,
638                                          const MCDisassembler *Decoder);
639 static DecodeStatus DecodeVpredROperand(MCInst &Inst, unsigned Val,
640                                         uint64_t Address,
641                                         const MCDisassembler *Decoder);
642 static DecodeStatus
643 DecodeRestrictedIPredicateOperand(MCInst &Inst, unsigned Val, uint64_t Address,
644                                   const MCDisassembler *Decoder);
645 static DecodeStatus
646 DecodeRestrictedSPredicateOperand(MCInst &Inst, unsigned Val, uint64_t Address,
647                                   const MCDisassembler *Decoder);
648 static DecodeStatus
649 DecodeRestrictedUPredicateOperand(MCInst &Inst, unsigned Val, uint64_t Address,
650                                   const MCDisassembler *Decoder);
651 static DecodeStatus
652 DecodeRestrictedFPPredicateOperand(MCInst &Inst, unsigned Val, uint64_t Address,
653                                    const MCDisassembler *Decoder);
654 template <bool Writeback>
655 static DecodeStatus DecodeVSTRVLDR_SYSREG(MCInst &Inst, unsigned Insn,
656                                           uint64_t Address,
657                                           const MCDisassembler *Decoder);
658 template <int shift>
659 static DecodeStatus DecodeMVE_MEM_1_pre(MCInst &Inst, unsigned Val,
660                                         uint64_t Address,
661                                         const MCDisassembler *Decoder);
662 template <int shift>
663 static DecodeStatus DecodeMVE_MEM_2_pre(MCInst &Inst, unsigned Val,
664                                         uint64_t Address,
665                                         const MCDisassembler *Decoder);
666 template <int shift>
667 static DecodeStatus DecodeMVE_MEM_3_pre(MCInst &Inst, unsigned Val,
668                                         uint64_t Address,
669                                         const MCDisassembler *Decoder);
670 template <unsigned MinLog, unsigned MaxLog>
671 static DecodeStatus DecodePowerTwoOperand(MCInst &Inst, unsigned Val,
672                                           uint64_t Address,
673                                           const MCDisassembler *Decoder);
674 template <unsigned start>
675 static DecodeStatus
676 DecodeMVEPairVectorIndexOperand(MCInst &Inst, unsigned Val, uint64_t Address,
677                                 const MCDisassembler *Decoder);
678 static DecodeStatus DecodeMVEVMOVQtoDReg(MCInst &Inst, unsigned Insn,
679                                          uint64_t Address,
680                                          const MCDisassembler *Decoder);
681 static DecodeStatus DecodeMVEVMOVDRegtoQ(MCInst &Inst, unsigned Insn,
682                                          uint64_t Address,
683                                          const MCDisassembler *Decoder);
684 static DecodeStatus DecodeMVEVCVTt1fp(MCInst &Inst, unsigned Insn,
685                                       uint64_t Address,
686                                       const MCDisassembler *Decoder);
687 typedef DecodeStatus OperandDecoder(MCInst &Inst, unsigned Val,
688                                     uint64_t Address,
689                                     const MCDisassembler *Decoder);
690 template <bool scalar, OperandDecoder predicate_decoder>
691 static DecodeStatus DecodeMVEVCMP(MCInst &Inst, unsigned Insn, uint64_t Address,
692                                   const MCDisassembler *Decoder);
693 static DecodeStatus DecodeMveVCTP(MCInst &Inst, unsigned Insn, uint64_t Address,
694                                   const MCDisassembler *Decoder);
695 static DecodeStatus DecodeMVEVPNOT(MCInst &Inst, unsigned Insn,
696                                    uint64_t Address,
697                                    const MCDisassembler *Decoder);
698 static DecodeStatus
699 DecodeMVEOverlappingLongShift(MCInst &Inst, unsigned Insn, uint64_t Address,
700                               const MCDisassembler *Decoder);
701 static DecodeStatus DecodeT2AddSubSPImm(MCInst &Inst, unsigned Insn,
702                                         uint64_t Address,
703                                         const MCDisassembler *Decoder);
704 
705 #include "ARMGenDisassemblerTables.inc"
706 
707 static MCDisassembler *createARMDisassembler(const Target &T,
708                                              const MCSubtargetInfo &STI,
709                                              MCContext &Ctx) {
710   return new ARMDisassembler(STI, Ctx);
711 }
712 
713 // Post-decoding checks
714 static DecodeStatus checkDecodedInstruction(MCInst &MI, uint64_t &Size,
715                                             uint64_t Address, raw_ostream &CS,
716                                             uint32_t Insn,
717                                             DecodeStatus Result) {
718   switch (MI.getOpcode()) {
719     case ARM::HVC: {
720       // HVC is undefined if condition = 0xf otherwise upredictable
721       // if condition != 0xe
722       uint32_t Cond = (Insn >> 28) & 0xF;
723       if (Cond == 0xF)
724         return MCDisassembler::Fail;
725       if (Cond != 0xE)
726         return MCDisassembler::SoftFail;
727       return Result;
728     }
729     case ARM::t2ADDri:
730     case ARM::t2ADDri12:
731     case ARM::t2ADDrr:
732     case ARM::t2ADDrs:
733     case ARM::t2SUBri:
734     case ARM::t2SUBri12:
735     case ARM::t2SUBrr:
736     case ARM::t2SUBrs:
737       if (MI.getOperand(0).getReg() == ARM::SP &&
738           MI.getOperand(1).getReg() != ARM::SP)
739         return MCDisassembler::SoftFail;
740       return Result;
741     default: return Result;
742   }
743 }
744 
745 uint64_t ARMDisassembler::suggestBytesToSkip(ArrayRef<uint8_t> Bytes,
746                                              uint64_t Address) const {
747   // In Arm state, instructions are always 4 bytes wide, so there's no
748   // point in skipping any smaller number of bytes if an instruction
749   // can't be decoded.
750   if (!STI.getFeatureBits()[ARM::ModeThumb])
751     return 4;
752 
753   // In a Thumb instruction stream, a halfword is a standalone 2-byte
754   // instruction if and only if its value is less than 0xE800.
755   // Otherwise, it's the first halfword of a 4-byte instruction.
756   //
757   // So, if we can see the upcoming halfword, we can judge on that
758   // basis, and maybe skip a whole 4-byte instruction that we don't
759   // know how to decode, without accidentally trying to interpret its
760   // second half as something else.
761   //
762   // If we don't have the instruction data available, we just have to
763   // recommend skipping the minimum sensible distance, which is 2
764   // bytes.
765   if (Bytes.size() < 2)
766     return 2;
767 
768   uint16_t Insn16 = (Bytes[1] << 8) | Bytes[0];
769   return Insn16 < 0xE800 ? 2 : 4;
770 }
771 
772 DecodeStatus ARMDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
773                                              ArrayRef<uint8_t> Bytes,
774                                              uint64_t Address,
775                                              raw_ostream &CS) const {
776   if (STI.getFeatureBits()[ARM::ModeThumb])
777     return getThumbInstruction(MI, Size, Bytes, Address, CS);
778   return getARMInstruction(MI, Size, Bytes, Address, CS);
779 }
780 
781 DecodeStatus ARMDisassembler::getARMInstruction(MCInst &MI, uint64_t &Size,
782                                                 ArrayRef<uint8_t> Bytes,
783                                                 uint64_t Address,
784                                                 raw_ostream &CS) const {
785   CommentStream = &CS;
786 
787   assert(!STI.getFeatureBits()[ARM::ModeThumb] &&
788          "Asked to disassemble an ARM instruction but Subtarget is in Thumb "
789          "mode!");
790 
791   // We want to read exactly 4 bytes of data.
792   if (Bytes.size() < 4) {
793     Size = 0;
794     return MCDisassembler::Fail;
795   }
796 
797   // Encoded as a small-endian 32-bit word in the stream.
798   uint32_t Insn =
799       (Bytes[3] << 24) | (Bytes[2] << 16) | (Bytes[1] << 8) | (Bytes[0] << 0);
800 
801   // Calling the auto-generated decoder function.
802   DecodeStatus Result =
803       decodeInstruction(DecoderTableARM32, MI, Insn, Address, this, STI);
804   if (Result != MCDisassembler::Fail) {
805     Size = 4;
806     return checkDecodedInstruction(MI, Size, Address, CS, Insn, Result);
807   }
808 
809   struct DecodeTable {
810     const uint8_t *P;
811     bool DecodePred;
812   };
813 
814   const DecodeTable Tables[] = {
815       {DecoderTableVFP32, false},      {DecoderTableVFPV832, false},
816       {DecoderTableNEONData32, true},  {DecoderTableNEONLoadStore32, true},
817       {DecoderTableNEONDup32, true},   {DecoderTablev8NEON32, false},
818       {DecoderTablev8Crypto32, false},
819   };
820 
821   for (auto Table : Tables) {
822     Result = decodeInstruction(Table.P, MI, Insn, Address, this, STI);
823     if (Result != MCDisassembler::Fail) {
824       Size = 4;
825       // Add a fake predicate operand, because we share these instruction
826       // definitions with Thumb2 where these instructions are predicable.
827       if (Table.DecodePred && !DecodePredicateOperand(MI, 0xE, Address, this))
828         return MCDisassembler::Fail;
829       return Result;
830     }
831   }
832 
833   Result =
834       decodeInstruction(DecoderTableCoProc32, MI, Insn, Address, this, STI);
835   if (Result != MCDisassembler::Fail) {
836     Size = 4;
837     return checkDecodedInstruction(MI, Size, Address, CS, Insn, Result);
838   }
839 
840   Size = 4;
841   return MCDisassembler::Fail;
842 }
843 
844 namespace llvm {
845 
846 extern const MCInstrDesc ARMInsts[];
847 
848 } // end namespace llvm
849 
850 /// tryAddingSymbolicOperand - trys to add a symbolic operand in place of the
851 /// immediate Value in the MCInst.  The immediate Value has had any PC
852 /// adjustment made by the caller.  If the instruction is a branch instruction
853 /// then isBranch is true, else false.  If the getOpInfo() function was set as
854 /// part of the setupForSymbolicDisassembly() call then that function is called
855 /// to get any symbolic information at the Address for this instruction.  If
856 /// that returns non-zero then the symbolic information it returns is used to
857 /// create an MCExpr and that is added as an operand to the MCInst.  If
858 /// getOpInfo() returns zero and isBranch is true then a symbol look up for
859 /// Value is done and if a symbol is found an MCExpr is created with that, else
860 /// an MCExpr with Value is created.  This function returns true if it adds an
861 /// operand to the MCInst and false otherwise.
862 static bool tryAddingSymbolicOperand(uint64_t Address, int32_t Value,
863                                      bool isBranch, uint64_t InstSize,
864                                      MCInst &MI,
865                                      const MCDisassembler *Decoder) {
866   // FIXME: Does it make sense for value to be negative?
867   return Decoder->tryAddingSymbolicOperand(MI, (uint32_t)Value, Address,
868                                            isBranch, /*Offset=*/0, /*OpSize=*/0,
869                                            InstSize);
870 }
871 
872 /// tryAddingPcLoadReferenceComment - trys to add a comment as to what is being
873 /// referenced by a load instruction with the base register that is the Pc.
874 /// These can often be values in a literal pool near the Address of the
875 /// instruction.  The Address of the instruction and its immediate Value are
876 /// used as a possible literal pool entry.  The SymbolLookUp call back will
877 /// return the name of a symbol referenced by the literal pool's entry if
878 /// the referenced address is that of a symbol.  Or it will return a pointer to
879 /// a literal 'C' string if the referenced address of the literal pool's entry
880 /// is an address into a section with 'C' string literals.
881 static void tryAddingPcLoadReferenceComment(uint64_t Address, int Value,
882                                             const MCDisassembler *Decoder) {
883   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
884   Dis->tryAddingPcLoadReferenceComment(Value, Address);
885 }
886 
887 // Thumb1 instructions don't have explicit S bits.  Rather, they
888 // implicitly set CPSR.  Since it's not represented in the encoding, the
889 // auto-generated decoder won't inject the CPSR operand.  We need to fix
890 // that as a post-pass.
891 static void AddThumb1SBit(MCInst &MI, bool InITBlock) {
892   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
893   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
894   MCInst::iterator I = MI.begin();
895   for (unsigned i = 0; i < NumOps; ++i, ++I) {
896     if (I == MI.end()) break;
897     if (OpInfo[i].isOptionalDef() && OpInfo[i].RegClass == ARM::CCRRegClassID) {
898       if (i > 0 && OpInfo[i-1].isPredicate()) continue;
899       MI.insert(I, MCOperand::createReg(InITBlock ? 0 : ARM::CPSR));
900       return;
901     }
902   }
903 
904   MI.insert(I, MCOperand::createReg(InITBlock ? 0 : ARM::CPSR));
905 }
906 
907 static bool isVectorPredicable(unsigned Opcode) {
908   const MCOperandInfo *OpInfo = ARMInsts[Opcode].OpInfo;
909   unsigned short NumOps = ARMInsts[Opcode].NumOperands;
910   for (unsigned i = 0; i < NumOps; ++i) {
911     if (ARM::isVpred(OpInfo[i].OperandType))
912       return true;
913   }
914   return false;
915 }
916 
917 // Most Thumb instructions don't have explicit predicates in the
918 // encoding, but rather get their predicates from IT context.  We need
919 // to fix up the predicate operands using this context information as a
920 // post-pass.
921 MCDisassembler::DecodeStatus
922 ARMDisassembler::AddThumbPredicate(MCInst &MI) const {
923   MCDisassembler::DecodeStatus S = Success;
924 
925   const FeatureBitset &FeatureBits = getSubtargetInfo().getFeatureBits();
926 
927   // A few instructions actually have predicates encoded in them.  Don't
928   // try to overwrite it if we're seeing one of those.
929   switch (MI.getOpcode()) {
930     case ARM::tBcc:
931     case ARM::t2Bcc:
932     case ARM::tCBZ:
933     case ARM::tCBNZ:
934     case ARM::tCPS:
935     case ARM::t2CPS3p:
936     case ARM::t2CPS2p:
937     case ARM::t2CPS1p:
938     case ARM::t2CSEL:
939     case ARM::t2CSINC:
940     case ARM::t2CSINV:
941     case ARM::t2CSNEG:
942     case ARM::tMOVSr:
943     case ARM::tSETEND:
944       // Some instructions (mostly conditional branches) are not
945       // allowed in IT blocks.
946       if (ITBlock.instrInITBlock())
947         S = SoftFail;
948       else
949         return Success;
950       break;
951     case ARM::t2HINT:
952       if (MI.getOperand(0).getImm() == 0x10 && (FeatureBits[ARM::FeatureRAS]) != 0)
953         S = SoftFail;
954       break;
955     case ARM::tB:
956     case ARM::t2B:
957     case ARM::t2TBB:
958     case ARM::t2TBH:
959       // Some instructions (mostly unconditional branches) can
960       // only appears at the end of, or outside of, an IT.
961       if (ITBlock.instrInITBlock() && !ITBlock.instrLastInITBlock())
962         S = SoftFail;
963       break;
964     default:
965       break;
966   }
967 
968   // Warn on non-VPT predicable instruction in a VPT block and a VPT
969   // predicable instruction in an IT block
970   if ((!isVectorPredicable(MI.getOpcode()) && VPTBlock.instrInVPTBlock()) ||
971        (isVectorPredicable(MI.getOpcode()) && ITBlock.instrInITBlock()))
972     S = SoftFail;
973 
974   // If we're in an IT/VPT block, base the predicate on that.  Otherwise,
975   // assume a predicate of AL.
976   unsigned CC = ARMCC::AL;
977   unsigned VCC = ARMVCC::None;
978   if (ITBlock.instrInITBlock()) {
979     CC = ITBlock.getITCC();
980     ITBlock.advanceITState();
981   } else if (VPTBlock.instrInVPTBlock()) {
982     VCC = VPTBlock.getVPTPred();
983     VPTBlock.advanceVPTState();
984   }
985 
986   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
987   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
988 
989   MCInst::iterator CCI = MI.begin();
990   for (unsigned i = 0; i < NumOps; ++i, ++CCI) {
991     if (OpInfo[i].isPredicate() || CCI == MI.end()) break;
992   }
993 
994   if (ARMInsts[MI.getOpcode()].isPredicable()) {
995     CCI = MI.insert(CCI, MCOperand::createImm(CC));
996     ++CCI;
997     if (CC == ARMCC::AL)
998       MI.insert(CCI, MCOperand::createReg(0));
999     else
1000       MI.insert(CCI, MCOperand::createReg(ARM::CPSR));
1001   } else if (CC != ARMCC::AL) {
1002     Check(S, SoftFail);
1003   }
1004 
1005   MCInst::iterator VCCI = MI.begin();
1006   unsigned VCCPos;
1007   for (VCCPos = 0; VCCPos < NumOps; ++VCCPos, ++VCCI) {
1008     if (ARM::isVpred(OpInfo[VCCPos].OperandType) || VCCI == MI.end()) break;
1009   }
1010 
1011   if (isVectorPredicable(MI.getOpcode())) {
1012     VCCI = MI.insert(VCCI, MCOperand::createImm(VCC));
1013     ++VCCI;
1014     if (VCC == ARMVCC::None)
1015       VCCI = MI.insert(VCCI, MCOperand::createReg(0));
1016     else
1017       VCCI = MI.insert(VCCI, MCOperand::createReg(ARM::P0));
1018     ++VCCI;
1019     VCCI = MI.insert(VCCI, MCOperand::createReg(0));
1020     ++VCCI;
1021     if (OpInfo[VCCPos].OperandType == ARM::OPERAND_VPRED_R) {
1022       int TiedOp = ARMInsts[MI.getOpcode()].getOperandConstraint(
1023         VCCPos + 3, MCOI::TIED_TO);
1024       assert(TiedOp >= 0 &&
1025              "Inactive register in vpred_r is not tied to an output!");
1026       // Copy the operand to ensure it's not invalidated when MI grows.
1027       MI.insert(VCCI, MCOperand(MI.getOperand(TiedOp)));
1028     }
1029   } else if (VCC != ARMVCC::None) {
1030     Check(S, SoftFail);
1031   }
1032 
1033   return S;
1034 }
1035 
1036 // Thumb VFP instructions are a special case.  Because we share their
1037 // encodings between ARM and Thumb modes, and they are predicable in ARM
1038 // mode, the auto-generated decoder will give them an (incorrect)
1039 // predicate operand.  We need to rewrite these operands based on the IT
1040 // context as a post-pass.
1041 void ARMDisassembler::UpdateThumbVFPPredicate(
1042   DecodeStatus &S, MCInst &MI) const {
1043   unsigned CC;
1044   CC = ITBlock.getITCC();
1045   if (CC == 0xF)
1046     CC = ARMCC::AL;
1047   if (ITBlock.instrInITBlock())
1048     ITBlock.advanceITState();
1049   else if (VPTBlock.instrInVPTBlock()) {
1050     CC = VPTBlock.getVPTPred();
1051     VPTBlock.advanceVPTState();
1052   }
1053 
1054   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
1055   MCInst::iterator I = MI.begin();
1056   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
1057   for (unsigned i = 0; i < NumOps; ++i, ++I) {
1058     if (OpInfo[i].isPredicate() ) {
1059       if (CC != ARMCC::AL && !ARMInsts[MI.getOpcode()].isPredicable())
1060         Check(S, SoftFail);
1061       I->setImm(CC);
1062       ++I;
1063       if (CC == ARMCC::AL)
1064         I->setReg(0);
1065       else
1066         I->setReg(ARM::CPSR);
1067       return;
1068     }
1069   }
1070 }
1071 
1072 DecodeStatus ARMDisassembler::getThumbInstruction(MCInst &MI, uint64_t &Size,
1073                                                   ArrayRef<uint8_t> Bytes,
1074                                                   uint64_t Address,
1075                                                   raw_ostream &CS) const {
1076   CommentStream = &CS;
1077 
1078   assert(STI.getFeatureBits()[ARM::ModeThumb] &&
1079          "Asked to disassemble in Thumb mode but Subtarget is in ARM mode!");
1080 
1081   // We want to read exactly 2 bytes of data.
1082   if (Bytes.size() < 2) {
1083     Size = 0;
1084     return MCDisassembler::Fail;
1085   }
1086 
1087   uint16_t Insn16 = (Bytes[1] << 8) | Bytes[0];
1088   DecodeStatus Result =
1089       decodeInstruction(DecoderTableThumb16, MI, Insn16, Address, this, STI);
1090   if (Result != MCDisassembler::Fail) {
1091     Size = 2;
1092     Check(Result, AddThumbPredicate(MI));
1093     return Result;
1094   }
1095 
1096   Result = decodeInstruction(DecoderTableThumbSBit16, MI, Insn16, Address, this,
1097                              STI);
1098   if (Result) {
1099     Size = 2;
1100     bool InITBlock = ITBlock.instrInITBlock();
1101     Check(Result, AddThumbPredicate(MI));
1102     AddThumb1SBit(MI, InITBlock);
1103     return Result;
1104   }
1105 
1106   Result =
1107       decodeInstruction(DecoderTableThumb216, MI, Insn16, Address, this, STI);
1108   if (Result != MCDisassembler::Fail) {
1109     Size = 2;
1110 
1111     // Nested IT blocks are UNPREDICTABLE.  Must be checked before we add
1112     // the Thumb predicate.
1113     if (MI.getOpcode() == ARM::t2IT && ITBlock.instrInITBlock())
1114       Result = MCDisassembler::SoftFail;
1115 
1116     Check(Result, AddThumbPredicate(MI));
1117 
1118     // If we find an IT instruction, we need to parse its condition
1119     // code and mask operands so that we can apply them correctly
1120     // to the subsequent instructions.
1121     if (MI.getOpcode() == ARM::t2IT) {
1122       unsigned Firstcond = MI.getOperand(0).getImm();
1123       unsigned Mask = MI.getOperand(1).getImm();
1124       ITBlock.setITState(Firstcond, Mask);
1125 
1126       // An IT instruction that would give a 'NV' predicate is unpredictable.
1127       if (Firstcond == ARMCC::AL && !isPowerOf2_32(Mask))
1128         CS << "unpredictable IT predicate sequence";
1129     }
1130 
1131     return Result;
1132   }
1133 
1134   // We want to read exactly 4 bytes of data.
1135   if (Bytes.size() < 4) {
1136     Size = 0;
1137     return MCDisassembler::Fail;
1138   }
1139 
1140   uint32_t Insn32 =
1141       (Bytes[3] << 8) | (Bytes[2] << 0) | (Bytes[1] << 24) | (Bytes[0] << 16);
1142 
1143   Result =
1144       decodeInstruction(DecoderTableMVE32, MI, Insn32, Address, this, STI);
1145   if (Result != MCDisassembler::Fail) {
1146     Size = 4;
1147 
1148     // Nested VPT blocks are UNPREDICTABLE. Must be checked before we add
1149     // the VPT predicate.
1150     if (isVPTOpcode(MI.getOpcode()) && VPTBlock.instrInVPTBlock())
1151       Result = MCDisassembler::SoftFail;
1152 
1153     Check(Result, AddThumbPredicate(MI));
1154 
1155     if (isVPTOpcode(MI.getOpcode())) {
1156       unsigned Mask = MI.getOperand(0).getImm();
1157       VPTBlock.setVPTState(Mask);
1158     }
1159 
1160     return Result;
1161   }
1162 
1163   Result =
1164       decodeInstruction(DecoderTableThumb32, MI, Insn32, Address, this, STI);
1165   if (Result != MCDisassembler::Fail) {
1166     Size = 4;
1167     bool InITBlock = ITBlock.instrInITBlock();
1168     Check(Result, AddThumbPredicate(MI));
1169     AddThumb1SBit(MI, InITBlock);
1170     return Result;
1171   }
1172 
1173   Result =
1174       decodeInstruction(DecoderTableThumb232, MI, Insn32, Address, this, STI);
1175   if (Result != MCDisassembler::Fail) {
1176     Size = 4;
1177     Check(Result, AddThumbPredicate(MI));
1178     return checkDecodedInstruction(MI, Size, Address, CS, Insn32, Result);
1179   }
1180 
1181   if (fieldFromInstruction(Insn32, 28, 4) == 0xE) {
1182     Result =
1183         decodeInstruction(DecoderTableVFP32, MI, Insn32, Address, this, STI);
1184     if (Result != MCDisassembler::Fail) {
1185       Size = 4;
1186       UpdateThumbVFPPredicate(Result, MI);
1187       return Result;
1188     }
1189   }
1190 
1191   Result =
1192       decodeInstruction(DecoderTableVFPV832, MI, Insn32, Address, this, STI);
1193   if (Result != MCDisassembler::Fail) {
1194     Size = 4;
1195     return Result;
1196   }
1197 
1198   if (fieldFromInstruction(Insn32, 28, 4) == 0xE) {
1199     Result = decodeInstruction(DecoderTableNEONDup32, MI, Insn32, Address, this,
1200                                STI);
1201     if (Result != MCDisassembler::Fail) {
1202       Size = 4;
1203       Check(Result, AddThumbPredicate(MI));
1204       return Result;
1205     }
1206   }
1207 
1208   if (fieldFromInstruction(Insn32, 24, 8) == 0xF9) {
1209     uint32_t NEONLdStInsn = Insn32;
1210     NEONLdStInsn &= 0xF0FFFFFF;
1211     NEONLdStInsn |= 0x04000000;
1212     Result = decodeInstruction(DecoderTableNEONLoadStore32, MI, NEONLdStInsn,
1213                                Address, this, STI);
1214     if (Result != MCDisassembler::Fail) {
1215       Size = 4;
1216       Check(Result, AddThumbPredicate(MI));
1217       return Result;
1218     }
1219   }
1220 
1221   if (fieldFromInstruction(Insn32, 24, 4) == 0xF) {
1222     uint32_t NEONDataInsn = Insn32;
1223     NEONDataInsn &= 0xF0FFFFFF; // Clear bits 27-24
1224     NEONDataInsn |= (NEONDataInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
1225     NEONDataInsn |= 0x12000000; // Set bits 28 and 25
1226     Result = decodeInstruction(DecoderTableNEONData32, MI, NEONDataInsn,
1227                                Address, this, STI);
1228     if (Result != MCDisassembler::Fail) {
1229       Size = 4;
1230       Check(Result, AddThumbPredicate(MI));
1231       return Result;
1232     }
1233 
1234     uint32_t NEONCryptoInsn = Insn32;
1235     NEONCryptoInsn &= 0xF0FFFFFF; // Clear bits 27-24
1236     NEONCryptoInsn |= (NEONCryptoInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
1237     NEONCryptoInsn |= 0x12000000; // Set bits 28 and 25
1238     Result = decodeInstruction(DecoderTablev8Crypto32, MI, NEONCryptoInsn,
1239                                Address, this, STI);
1240     if (Result != MCDisassembler::Fail) {
1241       Size = 4;
1242       return Result;
1243     }
1244 
1245     uint32_t NEONv8Insn = Insn32;
1246     NEONv8Insn &= 0xF3FFFFFF; // Clear bits 27-26
1247     Result = decodeInstruction(DecoderTablev8NEON32, MI, NEONv8Insn, Address,
1248                                this, STI);
1249     if (Result != MCDisassembler::Fail) {
1250       Size = 4;
1251       return Result;
1252     }
1253   }
1254 
1255   uint32_t Coproc = fieldFromInstruction(Insn32, 8, 4);
1256   const uint8_t *DecoderTable = ARM::isCDECoproc(Coproc, STI)
1257                                     ? DecoderTableThumb2CDE32
1258                                     : DecoderTableThumb2CoProc32;
1259   Result =
1260       decodeInstruction(DecoderTable, MI, Insn32, Address, this, STI);
1261   if (Result != MCDisassembler::Fail) {
1262     Size = 4;
1263     Check(Result, AddThumbPredicate(MI));
1264     return Result;
1265   }
1266 
1267   Size = 0;
1268   return MCDisassembler::Fail;
1269 }
1270 
1271 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeARMDisassembler() {
1272   TargetRegistry::RegisterMCDisassembler(getTheARMLETarget(),
1273                                          createARMDisassembler);
1274   TargetRegistry::RegisterMCDisassembler(getTheARMBETarget(),
1275                                          createARMDisassembler);
1276   TargetRegistry::RegisterMCDisassembler(getTheThumbLETarget(),
1277                                          createARMDisassembler);
1278   TargetRegistry::RegisterMCDisassembler(getTheThumbBETarget(),
1279                                          createARMDisassembler);
1280 }
1281 
1282 static const uint16_t GPRDecoderTable[] = {
1283   ARM::R0, ARM::R1, ARM::R2, ARM::R3,
1284   ARM::R4, ARM::R5, ARM::R6, ARM::R7,
1285   ARM::R8, ARM::R9, ARM::R10, ARM::R11,
1286   ARM::R12, ARM::SP, ARM::LR, ARM::PC
1287 };
1288 
1289 static const uint16_t CLRMGPRDecoderTable[] = {
1290   ARM::R0, ARM::R1, ARM::R2, ARM::R3,
1291   ARM::R4, ARM::R5, ARM::R6, ARM::R7,
1292   ARM::R8, ARM::R9, ARM::R10, ARM::R11,
1293   ARM::R12, 0, ARM::LR, ARM::APSR
1294 };
1295 
1296 static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1297                                            uint64_t Address,
1298                                            const MCDisassembler *Decoder) {
1299   if (RegNo > 15)
1300     return MCDisassembler::Fail;
1301 
1302   unsigned Register = GPRDecoderTable[RegNo];
1303   Inst.addOperand(MCOperand::createReg(Register));
1304   return MCDisassembler::Success;
1305 }
1306 
1307 static DecodeStatus DecodeCLRMGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1308                                                uint64_t Address,
1309                                                const MCDisassembler *Decoder) {
1310   if (RegNo > 15)
1311     return MCDisassembler::Fail;
1312 
1313   unsigned Register = CLRMGPRDecoderTable[RegNo];
1314   if (Register == 0)
1315     return MCDisassembler::Fail;
1316 
1317   Inst.addOperand(MCOperand::createReg(Register));
1318   return MCDisassembler::Success;
1319 }
1320 
1321 static DecodeStatus DecodeGPRnopcRegisterClass(MCInst &Inst, unsigned RegNo,
1322                                                uint64_t Address,
1323                                                const MCDisassembler *Decoder) {
1324   DecodeStatus S = MCDisassembler::Success;
1325 
1326   if (RegNo == 15)
1327     S = MCDisassembler::SoftFail;
1328 
1329   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1330 
1331   return S;
1332 }
1333 
1334 static DecodeStatus DecodeGPRnospRegisterClass(MCInst &Inst, unsigned RegNo,
1335                                                uint64_t Address,
1336                                                const MCDisassembler *Decoder) {
1337   DecodeStatus S = MCDisassembler::Success;
1338 
1339   if (RegNo == 13)
1340     S = MCDisassembler::SoftFail;
1341 
1342   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1343 
1344   return S;
1345 }
1346 
1347 static DecodeStatus
1348 DecodeGPRwithAPSRRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Address,
1349                                const MCDisassembler *Decoder) {
1350   DecodeStatus S = MCDisassembler::Success;
1351 
1352   if (RegNo == 15)
1353   {
1354     Inst.addOperand(MCOperand::createReg(ARM::APSR_NZCV));
1355     return MCDisassembler::Success;
1356   }
1357 
1358   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1359   return S;
1360 }
1361 
1362 static DecodeStatus
1363 DecodeGPRwithZRRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Address,
1364                              const MCDisassembler *Decoder) {
1365   DecodeStatus S = MCDisassembler::Success;
1366 
1367   if (RegNo == 15)
1368   {
1369     Inst.addOperand(MCOperand::createReg(ARM::ZR));
1370     return MCDisassembler::Success;
1371   }
1372 
1373   if (RegNo == 13)
1374     Check(S, MCDisassembler::SoftFail);
1375 
1376   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1377   return S;
1378 }
1379 
1380 static DecodeStatus
1381 DecodeGPRwithZRnospRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Address,
1382                                  const MCDisassembler *Decoder) {
1383   DecodeStatus S = MCDisassembler::Success;
1384   if (RegNo == 13)
1385     return MCDisassembler::Fail;
1386   Check(S, DecodeGPRwithZRRegisterClass(Inst, RegNo, Address, Decoder));
1387   return S;
1388 }
1389 
1390 static DecodeStatus DecodetGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1391                                             uint64_t Address,
1392                                             const MCDisassembler *Decoder) {
1393   if (RegNo > 7)
1394     return MCDisassembler::Fail;
1395   return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
1396 }
1397 
1398 static const uint16_t GPRPairDecoderTable[] = {
1399   ARM::R0_R1, ARM::R2_R3,   ARM::R4_R5,  ARM::R6_R7,
1400   ARM::R8_R9, ARM::R10_R11, ARM::R12_SP
1401 };
1402 
1403 static DecodeStatus DecodeGPRPairRegisterClass(MCInst &Inst, unsigned RegNo,
1404                                                uint64_t Address,
1405                                                const MCDisassembler *Decoder) {
1406   DecodeStatus S = MCDisassembler::Success;
1407 
1408   // According to the Arm ARM RegNo = 14 is undefined, but we return fail
1409   // rather than SoftFail as there is no GPRPair table entry for index 7.
1410   if (RegNo > 13)
1411     return MCDisassembler::Fail;
1412 
1413   if (RegNo & 1)
1414      S = MCDisassembler::SoftFail;
1415 
1416   unsigned RegisterPair = GPRPairDecoderTable[RegNo/2];
1417   Inst.addOperand(MCOperand::createReg(RegisterPair));
1418   return S;
1419 }
1420 
1421 static DecodeStatus
1422 DecodeGPRPairnospRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Address,
1423                                const MCDisassembler *Decoder) {
1424   if (RegNo > 13)
1425     return MCDisassembler::Fail;
1426 
1427   unsigned RegisterPair = GPRPairDecoderTable[RegNo/2];
1428   Inst.addOperand(MCOperand::createReg(RegisterPair));
1429 
1430   if ((RegNo & 1) || RegNo > 10)
1431      return MCDisassembler::SoftFail;
1432   return MCDisassembler::Success;
1433 }
1434 
1435 static DecodeStatus DecodeGPRspRegisterClass(MCInst &Inst, unsigned RegNo,
1436                                              uint64_t Address,
1437                                              const MCDisassembler *Decoder) {
1438   if (RegNo != 13)
1439     return MCDisassembler::Fail;
1440 
1441   unsigned Register = GPRDecoderTable[RegNo];
1442   Inst.addOperand(MCOperand::createReg(Register));
1443   return MCDisassembler::Success;
1444 }
1445 
1446 static DecodeStatus DecodetcGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1447                                              uint64_t Address,
1448                                              const MCDisassembler *Decoder) {
1449   unsigned Register = 0;
1450   switch (RegNo) {
1451     case 0:
1452       Register = ARM::R0;
1453       break;
1454     case 1:
1455       Register = ARM::R1;
1456       break;
1457     case 2:
1458       Register = ARM::R2;
1459       break;
1460     case 3:
1461       Register = ARM::R3;
1462       break;
1463     case 9:
1464       Register = ARM::R9;
1465       break;
1466     case 12:
1467       Register = ARM::R12;
1468       break;
1469     default:
1470       return MCDisassembler::Fail;
1471     }
1472 
1473   Inst.addOperand(MCOperand::createReg(Register));
1474   return MCDisassembler::Success;
1475 }
1476 
1477 static DecodeStatus DecoderGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1478                                             uint64_t Address,
1479                                             const MCDisassembler *Decoder) {
1480   DecodeStatus S = MCDisassembler::Success;
1481 
1482   const FeatureBitset &featureBits =
1483     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1484 
1485   if ((RegNo == 13 && !featureBits[ARM::HasV8Ops]) || RegNo == 15)
1486     S = MCDisassembler::SoftFail;
1487 
1488   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1489   return S;
1490 }
1491 
1492 static const uint16_t SPRDecoderTable[] = {
1493      ARM::S0,  ARM::S1,  ARM::S2,  ARM::S3,
1494      ARM::S4,  ARM::S5,  ARM::S6,  ARM::S7,
1495      ARM::S8,  ARM::S9, ARM::S10, ARM::S11,
1496     ARM::S12, ARM::S13, ARM::S14, ARM::S15,
1497     ARM::S16, ARM::S17, ARM::S18, ARM::S19,
1498     ARM::S20, ARM::S21, ARM::S22, ARM::S23,
1499     ARM::S24, ARM::S25, ARM::S26, ARM::S27,
1500     ARM::S28, ARM::S29, ARM::S30, ARM::S31
1501 };
1502 
1503 static DecodeStatus DecodeSPRRegisterClass(MCInst &Inst, unsigned RegNo,
1504                                            uint64_t Address,
1505                                            const MCDisassembler *Decoder) {
1506   if (RegNo > 31)
1507     return MCDisassembler::Fail;
1508 
1509   unsigned Register = SPRDecoderTable[RegNo];
1510   Inst.addOperand(MCOperand::createReg(Register));
1511   return MCDisassembler::Success;
1512 }
1513 
1514 static DecodeStatus DecodeHPRRegisterClass(MCInst &Inst, unsigned RegNo,
1515                                            uint64_t Address,
1516                                            const MCDisassembler *Decoder) {
1517   return DecodeSPRRegisterClass(Inst, RegNo, Address, Decoder);
1518 }
1519 
1520 static const uint16_t DPRDecoderTable[] = {
1521      ARM::D0,  ARM::D1,  ARM::D2,  ARM::D3,
1522      ARM::D4,  ARM::D5,  ARM::D6,  ARM::D7,
1523      ARM::D8,  ARM::D9, ARM::D10, ARM::D11,
1524     ARM::D12, ARM::D13, ARM::D14, ARM::D15,
1525     ARM::D16, ARM::D17, ARM::D18, ARM::D19,
1526     ARM::D20, ARM::D21, ARM::D22, ARM::D23,
1527     ARM::D24, ARM::D25, ARM::D26, ARM::D27,
1528     ARM::D28, ARM::D29, ARM::D30, ARM::D31
1529 };
1530 
1531 static DecodeStatus DecodeDPRRegisterClass(MCInst &Inst, unsigned RegNo,
1532                                            uint64_t Address,
1533                                            const MCDisassembler *Decoder) {
1534   const FeatureBitset &featureBits =
1535     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1536 
1537   bool hasD32 = featureBits[ARM::FeatureD32];
1538 
1539   if (RegNo > 31 || (!hasD32 && RegNo > 15))
1540     return MCDisassembler::Fail;
1541 
1542   unsigned Register = DPRDecoderTable[RegNo];
1543   Inst.addOperand(MCOperand::createReg(Register));
1544   return MCDisassembler::Success;
1545 }
1546 
1547 static DecodeStatus DecodeDPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
1548                                              uint64_t Address,
1549                                              const MCDisassembler *Decoder) {
1550   if (RegNo > 7)
1551     return MCDisassembler::Fail;
1552   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
1553 }
1554 
1555 static DecodeStatus DecodeSPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
1556                                              uint64_t Address,
1557                                              const MCDisassembler *Decoder) {
1558   if (RegNo > 15)
1559     return MCDisassembler::Fail;
1560   return DecodeSPRRegisterClass(Inst, RegNo, Address, Decoder);
1561 }
1562 
1563 static DecodeStatus DecodeDPR_VFP2RegisterClass(MCInst &Inst, unsigned RegNo,
1564                                                 uint64_t Address,
1565                                                 const MCDisassembler *Decoder) {
1566   if (RegNo > 15)
1567     return MCDisassembler::Fail;
1568   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
1569 }
1570 
1571 static const uint16_t QPRDecoderTable[] = {
1572      ARM::Q0,  ARM::Q1,  ARM::Q2,  ARM::Q3,
1573      ARM::Q4,  ARM::Q5,  ARM::Q6,  ARM::Q7,
1574      ARM::Q8,  ARM::Q9, ARM::Q10, ARM::Q11,
1575     ARM::Q12, ARM::Q13, ARM::Q14, ARM::Q15
1576 };
1577 
1578 static DecodeStatus DecodeQPRRegisterClass(MCInst &Inst, unsigned RegNo,
1579                                            uint64_t Address,
1580                                            const MCDisassembler *Decoder) {
1581   if (RegNo > 31 || (RegNo & 1) != 0)
1582     return MCDisassembler::Fail;
1583   RegNo >>= 1;
1584 
1585   unsigned Register = QPRDecoderTable[RegNo];
1586   Inst.addOperand(MCOperand::createReg(Register));
1587   return MCDisassembler::Success;
1588 }
1589 
1590 static const uint16_t DPairDecoderTable[] = {
1591   ARM::Q0,  ARM::D1_D2,   ARM::Q1,  ARM::D3_D4,   ARM::Q2,  ARM::D5_D6,
1592   ARM::Q3,  ARM::D7_D8,   ARM::Q4,  ARM::D9_D10,  ARM::Q5,  ARM::D11_D12,
1593   ARM::Q6,  ARM::D13_D14, ARM::Q7,  ARM::D15_D16, ARM::Q8,  ARM::D17_D18,
1594   ARM::Q9,  ARM::D19_D20, ARM::Q10, ARM::D21_D22, ARM::Q11, ARM::D23_D24,
1595   ARM::Q12, ARM::D25_D26, ARM::Q13, ARM::D27_D28, ARM::Q14, ARM::D29_D30,
1596   ARM::Q15
1597 };
1598 
1599 static DecodeStatus DecodeDPairRegisterClass(MCInst &Inst, unsigned RegNo,
1600                                              uint64_t Address,
1601                                              const MCDisassembler *Decoder) {
1602   if (RegNo > 30)
1603     return MCDisassembler::Fail;
1604 
1605   unsigned Register = DPairDecoderTable[RegNo];
1606   Inst.addOperand(MCOperand::createReg(Register));
1607   return MCDisassembler::Success;
1608 }
1609 
1610 static const uint16_t DPairSpacedDecoderTable[] = {
1611   ARM::D0_D2,   ARM::D1_D3,   ARM::D2_D4,   ARM::D3_D5,
1612   ARM::D4_D6,   ARM::D5_D7,   ARM::D6_D8,   ARM::D7_D9,
1613   ARM::D8_D10,  ARM::D9_D11,  ARM::D10_D12, ARM::D11_D13,
1614   ARM::D12_D14, ARM::D13_D15, ARM::D14_D16, ARM::D15_D17,
1615   ARM::D16_D18, ARM::D17_D19, ARM::D18_D20, ARM::D19_D21,
1616   ARM::D20_D22, ARM::D21_D23, ARM::D22_D24, ARM::D23_D25,
1617   ARM::D24_D26, ARM::D25_D27, ARM::D26_D28, ARM::D27_D29,
1618   ARM::D28_D30, ARM::D29_D31
1619 };
1620 
1621 static DecodeStatus
1622 DecodeDPairSpacedRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Address,
1623                                const MCDisassembler *Decoder) {
1624   if (RegNo > 29)
1625     return MCDisassembler::Fail;
1626 
1627   unsigned Register = DPairSpacedDecoderTable[RegNo];
1628   Inst.addOperand(MCOperand::createReg(Register));
1629   return MCDisassembler::Success;
1630 }
1631 
1632 static DecodeStatus DecodePredicateOperand(MCInst &Inst, unsigned Val,
1633                                            uint64_t Address,
1634                                            const MCDisassembler *Decoder) {
1635   DecodeStatus S = MCDisassembler::Success;
1636   if (Val == 0xF) return MCDisassembler::Fail;
1637   // AL predicate is not allowed on Thumb1 branches.
1638   if (Inst.getOpcode() == ARM::tBcc && Val == 0xE)
1639     return MCDisassembler::Fail;
1640   if (Val != ARMCC::AL && !ARMInsts[Inst.getOpcode()].isPredicable())
1641     Check(S, MCDisassembler::SoftFail);
1642   Inst.addOperand(MCOperand::createImm(Val));
1643   if (Val == ARMCC::AL) {
1644     Inst.addOperand(MCOperand::createReg(0));
1645   } else
1646     Inst.addOperand(MCOperand::createReg(ARM::CPSR));
1647   return S;
1648 }
1649 
1650 static DecodeStatus DecodeCCOutOperand(MCInst &Inst, unsigned Val,
1651                                        uint64_t Address,
1652                                        const MCDisassembler *Decoder) {
1653   if (Val)
1654     Inst.addOperand(MCOperand::createReg(ARM::CPSR));
1655   else
1656     Inst.addOperand(MCOperand::createReg(0));
1657   return MCDisassembler::Success;
1658 }
1659 
1660 static DecodeStatus DecodeSORegImmOperand(MCInst &Inst, unsigned Val,
1661                                           uint64_t Address,
1662                                           const MCDisassembler *Decoder) {
1663   DecodeStatus S = MCDisassembler::Success;
1664 
1665   unsigned Rm = fieldFromInstruction(Val, 0, 4);
1666   unsigned type = fieldFromInstruction(Val, 5, 2);
1667   unsigned imm = fieldFromInstruction(Val, 7, 5);
1668 
1669   // Register-immediate
1670   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
1671     return MCDisassembler::Fail;
1672 
1673   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1674   switch (type) {
1675     case 0:
1676       Shift = ARM_AM::lsl;
1677       break;
1678     case 1:
1679       Shift = ARM_AM::lsr;
1680       break;
1681     case 2:
1682       Shift = ARM_AM::asr;
1683       break;
1684     case 3:
1685       Shift = ARM_AM::ror;
1686       break;
1687   }
1688 
1689   if (Shift == ARM_AM::ror && imm == 0)
1690     Shift = ARM_AM::rrx;
1691 
1692   unsigned Op = Shift | (imm << 3);
1693   Inst.addOperand(MCOperand::createImm(Op));
1694 
1695   return S;
1696 }
1697 
1698 static DecodeStatus DecodeSORegRegOperand(MCInst &Inst, unsigned Val,
1699                                           uint64_t Address,
1700                                           const MCDisassembler *Decoder) {
1701   DecodeStatus S = MCDisassembler::Success;
1702 
1703   unsigned Rm = fieldFromInstruction(Val, 0, 4);
1704   unsigned type = fieldFromInstruction(Val, 5, 2);
1705   unsigned Rs = fieldFromInstruction(Val, 8, 4);
1706 
1707   // Register-register
1708   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1709     return MCDisassembler::Fail;
1710   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rs, Address, Decoder)))
1711     return MCDisassembler::Fail;
1712 
1713   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1714   switch (type) {
1715     case 0:
1716       Shift = ARM_AM::lsl;
1717       break;
1718     case 1:
1719       Shift = ARM_AM::lsr;
1720       break;
1721     case 2:
1722       Shift = ARM_AM::asr;
1723       break;
1724     case 3:
1725       Shift = ARM_AM::ror;
1726       break;
1727   }
1728 
1729   Inst.addOperand(MCOperand::createImm(Shift));
1730 
1731   return S;
1732 }
1733 
1734 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Val,
1735                                          uint64_t Address,
1736                                          const MCDisassembler *Decoder) {
1737   DecodeStatus S = MCDisassembler::Success;
1738 
1739   bool NeedDisjointWriteback = false;
1740   unsigned WritebackReg = 0;
1741   bool CLRM = false;
1742   switch (Inst.getOpcode()) {
1743   default:
1744     break;
1745   case ARM::LDMIA_UPD:
1746   case ARM::LDMDB_UPD:
1747   case ARM::LDMIB_UPD:
1748   case ARM::LDMDA_UPD:
1749   case ARM::t2LDMIA_UPD:
1750   case ARM::t2LDMDB_UPD:
1751   case ARM::t2STMIA_UPD:
1752   case ARM::t2STMDB_UPD:
1753     NeedDisjointWriteback = true;
1754     WritebackReg = Inst.getOperand(0).getReg();
1755     break;
1756   case ARM::t2CLRM:
1757     CLRM = true;
1758     break;
1759   }
1760 
1761   // Empty register lists are not allowed.
1762   if (Val == 0) return MCDisassembler::Fail;
1763   for (unsigned i = 0; i < 16; ++i) {
1764     if (Val & (1 << i)) {
1765       if (CLRM) {
1766         if (!Check(S, DecodeCLRMGPRRegisterClass(Inst, i, Address, Decoder))) {
1767           return MCDisassembler::Fail;
1768         }
1769       } else {
1770         if (!Check(S, DecodeGPRRegisterClass(Inst, i, Address, Decoder)))
1771           return MCDisassembler::Fail;
1772         // Writeback not allowed if Rn is in the target list.
1773         if (NeedDisjointWriteback && WritebackReg == Inst.end()[-1].getReg())
1774           Check(S, MCDisassembler::SoftFail);
1775       }
1776     }
1777   }
1778 
1779   return S;
1780 }
1781 
1782 static DecodeStatus DecodeSPRRegListOperand(MCInst &Inst, unsigned Val,
1783                                             uint64_t Address,
1784                                             const MCDisassembler *Decoder) {
1785   DecodeStatus S = MCDisassembler::Success;
1786 
1787   unsigned Vd = fieldFromInstruction(Val, 8, 5);
1788   unsigned regs = fieldFromInstruction(Val, 0, 8);
1789 
1790   // In case of unpredictable encoding, tweak the operands.
1791   if (regs == 0 || (Vd + regs) > 32) {
1792     regs = Vd + regs > 32 ? 32 - Vd : regs;
1793     regs = std::max( 1u, regs);
1794     S = MCDisassembler::SoftFail;
1795   }
1796 
1797   if (!Check(S, DecodeSPRRegisterClass(Inst, Vd, Address, Decoder)))
1798     return MCDisassembler::Fail;
1799   for (unsigned i = 0; i < (regs - 1); ++i) {
1800     if (!Check(S, DecodeSPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1801       return MCDisassembler::Fail;
1802   }
1803 
1804   return S;
1805 }
1806 
1807 static DecodeStatus DecodeDPRRegListOperand(MCInst &Inst, unsigned Val,
1808                                             uint64_t Address,
1809                                             const MCDisassembler *Decoder) {
1810   DecodeStatus S = MCDisassembler::Success;
1811 
1812   unsigned Vd = fieldFromInstruction(Val, 8, 5);
1813   unsigned regs = fieldFromInstruction(Val, 1, 7);
1814 
1815   // In case of unpredictable encoding, tweak the operands.
1816   if (regs == 0 || regs > 16 || (Vd + regs) > 32) {
1817     regs = Vd + regs > 32 ? 32 - Vd : regs;
1818     regs = std::max( 1u, regs);
1819     regs = std::min(16u, regs);
1820     S = MCDisassembler::SoftFail;
1821   }
1822 
1823   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
1824       return MCDisassembler::Fail;
1825   for (unsigned i = 0; i < (regs - 1); ++i) {
1826     if (!Check(S, DecodeDPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1827       return MCDisassembler::Fail;
1828   }
1829 
1830   return S;
1831 }
1832 
1833 static DecodeStatus DecodeBitfieldMaskOperand(MCInst &Inst, unsigned Val,
1834                                               uint64_t Address,
1835                                               const MCDisassembler *Decoder) {
1836   // This operand encodes a mask of contiguous zeros between a specified MSB
1837   // and LSB.  To decode it, we create the mask of all bits MSB-and-lower,
1838   // the mask of all bits LSB-and-lower, and then xor them to create
1839   // the mask of that's all ones on [msb, lsb].  Finally we not it to
1840   // create the final mask.
1841   unsigned msb = fieldFromInstruction(Val, 5, 5);
1842   unsigned lsb = fieldFromInstruction(Val, 0, 5);
1843 
1844   DecodeStatus S = MCDisassembler::Success;
1845   if (lsb > msb) {
1846     Check(S, MCDisassembler::SoftFail);
1847     // The check above will cause the warning for the "potentially undefined
1848     // instruction encoding" but we can't build a bad MCOperand value here
1849     // with a lsb > msb or else printing the MCInst will cause a crash.
1850     lsb = msb;
1851   }
1852 
1853   uint32_t msb_mask = 0xFFFFFFFF;
1854   if (msb != 31) msb_mask = (1U << (msb+1)) - 1;
1855   uint32_t lsb_mask = (1U << lsb) - 1;
1856 
1857   Inst.addOperand(MCOperand::createImm(~(msb_mask ^ lsb_mask)));
1858   return S;
1859 }
1860 
1861 static DecodeStatus DecodeCopMemInstruction(MCInst &Inst, unsigned Insn,
1862                                             uint64_t Address,
1863                                             const MCDisassembler *Decoder) {
1864   DecodeStatus S = MCDisassembler::Success;
1865 
1866   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1867   unsigned CRd = fieldFromInstruction(Insn, 12, 4);
1868   unsigned coproc = fieldFromInstruction(Insn, 8, 4);
1869   unsigned imm = fieldFromInstruction(Insn, 0, 8);
1870   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1871   unsigned U = fieldFromInstruction(Insn, 23, 1);
1872   const FeatureBitset &featureBits =
1873     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1874 
1875   switch (Inst.getOpcode()) {
1876     case ARM::LDC_OFFSET:
1877     case ARM::LDC_PRE:
1878     case ARM::LDC_POST:
1879     case ARM::LDC_OPTION:
1880     case ARM::LDCL_OFFSET:
1881     case ARM::LDCL_PRE:
1882     case ARM::LDCL_POST:
1883     case ARM::LDCL_OPTION:
1884     case ARM::STC_OFFSET:
1885     case ARM::STC_PRE:
1886     case ARM::STC_POST:
1887     case ARM::STC_OPTION:
1888     case ARM::STCL_OFFSET:
1889     case ARM::STCL_PRE:
1890     case ARM::STCL_POST:
1891     case ARM::STCL_OPTION:
1892     case ARM::t2LDC_OFFSET:
1893     case ARM::t2LDC_PRE:
1894     case ARM::t2LDC_POST:
1895     case ARM::t2LDC_OPTION:
1896     case ARM::t2LDCL_OFFSET:
1897     case ARM::t2LDCL_PRE:
1898     case ARM::t2LDCL_POST:
1899     case ARM::t2LDCL_OPTION:
1900     case ARM::t2STC_OFFSET:
1901     case ARM::t2STC_PRE:
1902     case ARM::t2STC_POST:
1903     case ARM::t2STC_OPTION:
1904     case ARM::t2STCL_OFFSET:
1905     case ARM::t2STCL_PRE:
1906     case ARM::t2STCL_POST:
1907     case ARM::t2STCL_OPTION:
1908     case ARM::t2LDC2_OFFSET:
1909     case ARM::t2LDC2L_OFFSET:
1910     case ARM::t2LDC2_PRE:
1911     case ARM::t2LDC2L_PRE:
1912     case ARM::t2STC2_OFFSET:
1913     case ARM::t2STC2L_OFFSET:
1914     case ARM::t2STC2_PRE:
1915     case ARM::t2STC2L_PRE:
1916     case ARM::LDC2_OFFSET:
1917     case ARM::LDC2L_OFFSET:
1918     case ARM::LDC2_PRE:
1919     case ARM::LDC2L_PRE:
1920     case ARM::STC2_OFFSET:
1921     case ARM::STC2L_OFFSET:
1922     case ARM::STC2_PRE:
1923     case ARM::STC2L_PRE:
1924     case ARM::t2LDC2_OPTION:
1925     case ARM::t2STC2_OPTION:
1926     case ARM::t2LDC2_POST:
1927     case ARM::t2LDC2L_POST:
1928     case ARM::t2STC2_POST:
1929     case ARM::t2STC2L_POST:
1930     case ARM::LDC2_POST:
1931     case ARM::LDC2L_POST:
1932     case ARM::STC2_POST:
1933     case ARM::STC2L_POST:
1934       if (coproc == 0xA || coproc == 0xB ||
1935           (featureBits[ARM::HasV8_1MMainlineOps] &&
1936            (coproc == 0x8 || coproc == 0x9 || coproc == 0xA || coproc == 0xB ||
1937             coproc == 0xE || coproc == 0xF)))
1938         return MCDisassembler::Fail;
1939       break;
1940     default:
1941       break;
1942   }
1943 
1944   if (featureBits[ARM::HasV8Ops] && (coproc != 14))
1945     return MCDisassembler::Fail;
1946 
1947   Inst.addOperand(MCOperand::createImm(coproc));
1948   Inst.addOperand(MCOperand::createImm(CRd));
1949   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1950     return MCDisassembler::Fail;
1951 
1952   switch (Inst.getOpcode()) {
1953     case ARM::t2LDC2_OFFSET:
1954     case ARM::t2LDC2L_OFFSET:
1955     case ARM::t2LDC2_PRE:
1956     case ARM::t2LDC2L_PRE:
1957     case ARM::t2STC2_OFFSET:
1958     case ARM::t2STC2L_OFFSET:
1959     case ARM::t2STC2_PRE:
1960     case ARM::t2STC2L_PRE:
1961     case ARM::LDC2_OFFSET:
1962     case ARM::LDC2L_OFFSET:
1963     case ARM::LDC2_PRE:
1964     case ARM::LDC2L_PRE:
1965     case ARM::STC2_OFFSET:
1966     case ARM::STC2L_OFFSET:
1967     case ARM::STC2_PRE:
1968     case ARM::STC2L_PRE:
1969     case ARM::t2LDC_OFFSET:
1970     case ARM::t2LDCL_OFFSET:
1971     case ARM::t2LDC_PRE:
1972     case ARM::t2LDCL_PRE:
1973     case ARM::t2STC_OFFSET:
1974     case ARM::t2STCL_OFFSET:
1975     case ARM::t2STC_PRE:
1976     case ARM::t2STCL_PRE:
1977     case ARM::LDC_OFFSET:
1978     case ARM::LDCL_OFFSET:
1979     case ARM::LDC_PRE:
1980     case ARM::LDCL_PRE:
1981     case ARM::STC_OFFSET:
1982     case ARM::STCL_OFFSET:
1983     case ARM::STC_PRE:
1984     case ARM::STCL_PRE:
1985       imm = ARM_AM::getAM5Opc(U ? ARM_AM::add : ARM_AM::sub, imm);
1986       Inst.addOperand(MCOperand::createImm(imm));
1987       break;
1988     case ARM::t2LDC2_POST:
1989     case ARM::t2LDC2L_POST:
1990     case ARM::t2STC2_POST:
1991     case ARM::t2STC2L_POST:
1992     case ARM::LDC2_POST:
1993     case ARM::LDC2L_POST:
1994     case ARM::STC2_POST:
1995     case ARM::STC2L_POST:
1996     case ARM::t2LDC_POST:
1997     case ARM::t2LDCL_POST:
1998     case ARM::t2STC_POST:
1999     case ARM::t2STCL_POST:
2000     case ARM::LDC_POST:
2001     case ARM::LDCL_POST:
2002     case ARM::STC_POST:
2003     case ARM::STCL_POST:
2004       imm |= U << 8;
2005       LLVM_FALLTHROUGH;
2006     default:
2007       // The 'option' variant doesn't encode 'U' in the immediate since
2008       // the immediate is unsigned [0,255].
2009       Inst.addOperand(MCOperand::createImm(imm));
2010       break;
2011   }
2012 
2013   switch (Inst.getOpcode()) {
2014     case ARM::LDC_OFFSET:
2015     case ARM::LDC_PRE:
2016     case ARM::LDC_POST:
2017     case ARM::LDC_OPTION:
2018     case ARM::LDCL_OFFSET:
2019     case ARM::LDCL_PRE:
2020     case ARM::LDCL_POST:
2021     case ARM::LDCL_OPTION:
2022     case ARM::STC_OFFSET:
2023     case ARM::STC_PRE:
2024     case ARM::STC_POST:
2025     case ARM::STC_OPTION:
2026     case ARM::STCL_OFFSET:
2027     case ARM::STCL_PRE:
2028     case ARM::STCL_POST:
2029     case ARM::STCL_OPTION:
2030       if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2031         return MCDisassembler::Fail;
2032       break;
2033     default:
2034       break;
2035   }
2036 
2037   return S;
2038 }
2039 
2040 static DecodeStatus
2041 DecodeAddrMode2IdxInstruction(MCInst &Inst, unsigned Insn, uint64_t Address,
2042                               const MCDisassembler *Decoder) {
2043   DecodeStatus S = MCDisassembler::Success;
2044 
2045   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2046   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
2047   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2048   unsigned imm = fieldFromInstruction(Insn, 0, 12);
2049   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2050   unsigned reg = fieldFromInstruction(Insn, 25, 1);
2051   unsigned P = fieldFromInstruction(Insn, 24, 1);
2052   unsigned W = fieldFromInstruction(Insn, 21, 1);
2053 
2054   // On stores, the writeback operand precedes Rt.
2055   switch (Inst.getOpcode()) {
2056     case ARM::STR_POST_IMM:
2057     case ARM::STR_POST_REG:
2058     case ARM::STRB_POST_IMM:
2059     case ARM::STRB_POST_REG:
2060     case ARM::STRT_POST_REG:
2061     case ARM::STRT_POST_IMM:
2062     case ARM::STRBT_POST_REG:
2063     case ARM::STRBT_POST_IMM:
2064       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2065         return MCDisassembler::Fail;
2066       break;
2067     default:
2068       break;
2069   }
2070 
2071   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
2072     return MCDisassembler::Fail;
2073 
2074   // On loads, the writeback operand comes after Rt.
2075   switch (Inst.getOpcode()) {
2076     case ARM::LDR_POST_IMM:
2077     case ARM::LDR_POST_REG:
2078     case ARM::LDRB_POST_IMM:
2079     case ARM::LDRB_POST_REG:
2080     case ARM::LDRBT_POST_REG:
2081     case ARM::LDRBT_POST_IMM:
2082     case ARM::LDRT_POST_REG:
2083     case ARM::LDRT_POST_IMM:
2084       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2085         return MCDisassembler::Fail;
2086       break;
2087     default:
2088       break;
2089   }
2090 
2091   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2092     return MCDisassembler::Fail;
2093 
2094   ARM_AM::AddrOpc Op = ARM_AM::add;
2095   if (!fieldFromInstruction(Insn, 23, 1))
2096     Op = ARM_AM::sub;
2097 
2098   bool writeback = (P == 0) || (W == 1);
2099   unsigned idx_mode = 0;
2100   if (P && writeback)
2101     idx_mode = ARMII::IndexModePre;
2102   else if (!P && writeback)
2103     idx_mode = ARMII::IndexModePost;
2104 
2105   if (writeback && (Rn == 15 || Rn == Rt))
2106     S = MCDisassembler::SoftFail; // UNPREDICTABLE
2107 
2108   if (reg) {
2109     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
2110       return MCDisassembler::Fail;
2111     ARM_AM::ShiftOpc Opc = ARM_AM::lsl;
2112     switch( fieldFromInstruction(Insn, 5, 2)) {
2113       case 0:
2114         Opc = ARM_AM::lsl;
2115         break;
2116       case 1:
2117         Opc = ARM_AM::lsr;
2118         break;
2119       case 2:
2120         Opc = ARM_AM::asr;
2121         break;
2122       case 3:
2123         Opc = ARM_AM::ror;
2124         break;
2125       default:
2126         return MCDisassembler::Fail;
2127     }
2128     unsigned amt = fieldFromInstruction(Insn, 7, 5);
2129     if (Opc == ARM_AM::ror && amt == 0)
2130       Opc = ARM_AM::rrx;
2131     unsigned imm = ARM_AM::getAM2Opc(Op, amt, Opc, idx_mode);
2132 
2133     Inst.addOperand(MCOperand::createImm(imm));
2134   } else {
2135     Inst.addOperand(MCOperand::createReg(0));
2136     unsigned tmp = ARM_AM::getAM2Opc(Op, imm, ARM_AM::lsl, idx_mode);
2137     Inst.addOperand(MCOperand::createImm(tmp));
2138   }
2139 
2140   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2141     return MCDisassembler::Fail;
2142 
2143   return S;
2144 }
2145 
2146 static DecodeStatus DecodeSORegMemOperand(MCInst &Inst, unsigned Val,
2147                                           uint64_t Address,
2148                                           const MCDisassembler *Decoder) {
2149   DecodeStatus S = MCDisassembler::Success;
2150 
2151   unsigned Rn = fieldFromInstruction(Val, 13, 4);
2152   unsigned Rm = fieldFromInstruction(Val,  0, 4);
2153   unsigned type = fieldFromInstruction(Val, 5, 2);
2154   unsigned imm = fieldFromInstruction(Val, 7, 5);
2155   unsigned U = fieldFromInstruction(Val, 12, 1);
2156 
2157   ARM_AM::ShiftOpc ShOp = ARM_AM::lsl;
2158   switch (type) {
2159     case 0:
2160       ShOp = ARM_AM::lsl;
2161       break;
2162     case 1:
2163       ShOp = ARM_AM::lsr;
2164       break;
2165     case 2:
2166       ShOp = ARM_AM::asr;
2167       break;
2168     case 3:
2169       ShOp = ARM_AM::ror;
2170       break;
2171   }
2172 
2173   if (ShOp == ARM_AM::ror && imm == 0)
2174     ShOp = ARM_AM::rrx;
2175 
2176   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2177     return MCDisassembler::Fail;
2178   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2179     return MCDisassembler::Fail;
2180   unsigned shift;
2181   if (U)
2182     shift = ARM_AM::getAM2Opc(ARM_AM::add, imm, ShOp);
2183   else
2184     shift = ARM_AM::getAM2Opc(ARM_AM::sub, imm, ShOp);
2185   Inst.addOperand(MCOperand::createImm(shift));
2186 
2187   return S;
2188 }
2189 
2190 static DecodeStatus DecodeTSBInstruction(MCInst &Inst, unsigned Insn,
2191                                          uint64_t Address,
2192                                          const MCDisassembler *Decoder) {
2193   if (Inst.getOpcode() != ARM::TSB && Inst.getOpcode() != ARM::t2TSB)
2194     return MCDisassembler::Fail;
2195 
2196   // The "csync" operand is not encoded into the "tsb" instruction (as this is
2197   // the only available operand), but LLVM expects the instruction to have one
2198   // operand, so we need to add the csync when decoding.
2199   Inst.addOperand(MCOperand::createImm(ARM_TSB::CSYNC));
2200   return MCDisassembler::Success;
2201 }
2202 
2203 static DecodeStatus DecodeAddrMode3Instruction(MCInst &Inst, unsigned Insn,
2204                                                uint64_t Address,
2205                                                const MCDisassembler *Decoder) {
2206   DecodeStatus S = MCDisassembler::Success;
2207 
2208   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
2209   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2210   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2211   unsigned type = fieldFromInstruction(Insn, 22, 1);
2212   unsigned imm = fieldFromInstruction(Insn, 8, 4);
2213   unsigned U = ((~fieldFromInstruction(Insn, 23, 1)) & 1) << 8;
2214   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2215   unsigned W = fieldFromInstruction(Insn, 21, 1);
2216   unsigned P = fieldFromInstruction(Insn, 24, 1);
2217   unsigned Rt2 = Rt + 1;
2218 
2219   bool writeback = (W == 1) | (P == 0);
2220 
2221   // For {LD,ST}RD, Rt must be even, else undefined.
2222   switch (Inst.getOpcode()) {
2223     case ARM::STRD:
2224     case ARM::STRD_PRE:
2225     case ARM::STRD_POST:
2226     case ARM::LDRD:
2227     case ARM::LDRD_PRE:
2228     case ARM::LDRD_POST:
2229       if (Rt & 0x1) S = MCDisassembler::SoftFail;
2230       break;
2231     default:
2232       break;
2233   }
2234   switch (Inst.getOpcode()) {
2235     case ARM::STRD:
2236     case ARM::STRD_PRE:
2237     case ARM::STRD_POST:
2238       if (P == 0 && W == 1)
2239         S = MCDisassembler::SoftFail;
2240 
2241       if (writeback && (Rn == 15 || Rn == Rt || Rn == Rt2))
2242         S = MCDisassembler::SoftFail;
2243       if (type && Rm == 15)
2244         S = MCDisassembler::SoftFail;
2245       if (Rt2 == 15)
2246         S = MCDisassembler::SoftFail;
2247       if (!type && fieldFromInstruction(Insn, 8, 4))
2248         S = MCDisassembler::SoftFail;
2249       break;
2250     case ARM::STRH:
2251     case ARM::STRH_PRE:
2252     case ARM::STRH_POST:
2253       if (Rt == 15)
2254         S = MCDisassembler::SoftFail;
2255       if (writeback && (Rn == 15 || Rn == Rt))
2256         S = MCDisassembler::SoftFail;
2257       if (!type && Rm == 15)
2258         S = MCDisassembler::SoftFail;
2259       break;
2260     case ARM::LDRD:
2261     case ARM::LDRD_PRE:
2262     case ARM::LDRD_POST:
2263       if (type && Rn == 15) {
2264         if (Rt2 == 15)
2265           S = MCDisassembler::SoftFail;
2266         break;
2267       }
2268       if (P == 0 && W == 1)
2269         S = MCDisassembler::SoftFail;
2270       if (!type && (Rt2 == 15 || Rm == 15 || Rm == Rt || Rm == Rt2))
2271         S = MCDisassembler::SoftFail;
2272       if (!type && writeback && Rn == 15)
2273         S = MCDisassembler::SoftFail;
2274       if (writeback && (Rn == Rt || Rn == Rt2))
2275         S = MCDisassembler::SoftFail;
2276       break;
2277     case ARM::LDRH:
2278     case ARM::LDRH_PRE:
2279     case ARM::LDRH_POST:
2280       if (type && Rn == 15) {
2281         if (Rt == 15)
2282           S = MCDisassembler::SoftFail;
2283         break;
2284       }
2285       if (Rt == 15)
2286         S = MCDisassembler::SoftFail;
2287       if (!type && Rm == 15)
2288         S = MCDisassembler::SoftFail;
2289       if (!type && writeback && (Rn == 15 || Rn == Rt))
2290         S = MCDisassembler::SoftFail;
2291       break;
2292     case ARM::LDRSH:
2293     case ARM::LDRSH_PRE:
2294     case ARM::LDRSH_POST:
2295     case ARM::LDRSB:
2296     case ARM::LDRSB_PRE:
2297     case ARM::LDRSB_POST:
2298       if (type && Rn == 15) {
2299         if (Rt == 15)
2300           S = MCDisassembler::SoftFail;
2301         break;
2302       }
2303       if (type && (Rt == 15 || (writeback && Rn == Rt)))
2304         S = MCDisassembler::SoftFail;
2305       if (!type && (Rt == 15 || Rm == 15))
2306         S = MCDisassembler::SoftFail;
2307       if (!type && writeback && (Rn == 15 || Rn == Rt))
2308         S = MCDisassembler::SoftFail;
2309       break;
2310     default:
2311       break;
2312   }
2313 
2314   if (writeback) { // Writeback
2315     if (P)
2316       U |= ARMII::IndexModePre << 9;
2317     else
2318       U |= ARMII::IndexModePost << 9;
2319 
2320     // On stores, the writeback operand precedes Rt.
2321     switch (Inst.getOpcode()) {
2322     case ARM::STRD:
2323     case ARM::STRD_PRE:
2324     case ARM::STRD_POST:
2325     case ARM::STRH:
2326     case ARM::STRH_PRE:
2327     case ARM::STRH_POST:
2328       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2329         return MCDisassembler::Fail;
2330       break;
2331     default:
2332       break;
2333     }
2334   }
2335 
2336   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
2337     return MCDisassembler::Fail;
2338   switch (Inst.getOpcode()) {
2339     case ARM::STRD:
2340     case ARM::STRD_PRE:
2341     case ARM::STRD_POST:
2342     case ARM::LDRD:
2343     case ARM::LDRD_PRE:
2344     case ARM::LDRD_POST:
2345       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder)))
2346         return MCDisassembler::Fail;
2347       break;
2348     default:
2349       break;
2350   }
2351 
2352   if (writeback) {
2353     // On loads, the writeback operand comes after Rt.
2354     switch (Inst.getOpcode()) {
2355     case ARM::LDRD:
2356     case ARM::LDRD_PRE:
2357     case ARM::LDRD_POST:
2358     case ARM::LDRH:
2359     case ARM::LDRH_PRE:
2360     case ARM::LDRH_POST:
2361     case ARM::LDRSH:
2362     case ARM::LDRSH_PRE:
2363     case ARM::LDRSH_POST:
2364     case ARM::LDRSB:
2365     case ARM::LDRSB_PRE:
2366     case ARM::LDRSB_POST:
2367     case ARM::LDRHTr:
2368     case ARM::LDRSBTr:
2369       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2370         return MCDisassembler::Fail;
2371       break;
2372     default:
2373       break;
2374     }
2375   }
2376 
2377   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2378     return MCDisassembler::Fail;
2379 
2380   if (type) {
2381     Inst.addOperand(MCOperand::createReg(0));
2382     Inst.addOperand(MCOperand::createImm(U | (imm << 4) | Rm));
2383   } else {
2384     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2385     return MCDisassembler::Fail;
2386     Inst.addOperand(MCOperand::createImm(U));
2387   }
2388 
2389   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2390     return MCDisassembler::Fail;
2391 
2392   return S;
2393 }
2394 
2395 static DecodeStatus DecodeRFEInstruction(MCInst &Inst, unsigned Insn,
2396                                          uint64_t Address,
2397                                          const MCDisassembler *Decoder) {
2398   DecodeStatus S = MCDisassembler::Success;
2399 
2400   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2401   unsigned mode = fieldFromInstruction(Insn, 23, 2);
2402 
2403   switch (mode) {
2404     case 0:
2405       mode = ARM_AM::da;
2406       break;
2407     case 1:
2408       mode = ARM_AM::ia;
2409       break;
2410     case 2:
2411       mode = ARM_AM::db;
2412       break;
2413     case 3:
2414       mode = ARM_AM::ib;
2415       break;
2416   }
2417 
2418   Inst.addOperand(MCOperand::createImm(mode));
2419   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2420     return MCDisassembler::Fail;
2421 
2422   return S;
2423 }
2424 
2425 static DecodeStatus DecodeQADDInstruction(MCInst &Inst, unsigned Insn,
2426                                           uint64_t Address,
2427                                           const MCDisassembler *Decoder) {
2428   DecodeStatus S = MCDisassembler::Success;
2429 
2430   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2431   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2432   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2433   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2434 
2435   if (pred == 0xF)
2436     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
2437 
2438   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2439     return MCDisassembler::Fail;
2440   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
2441     return MCDisassembler::Fail;
2442   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
2443     return MCDisassembler::Fail;
2444   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2445     return MCDisassembler::Fail;
2446   return S;
2447 }
2448 
2449 static DecodeStatus
2450 DecodeMemMultipleWritebackInstruction(MCInst &Inst, unsigned Insn,
2451                                       uint64_t Address,
2452                                       const MCDisassembler *Decoder) {
2453   DecodeStatus S = MCDisassembler::Success;
2454 
2455   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2456   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2457   unsigned reglist = fieldFromInstruction(Insn, 0, 16);
2458 
2459   if (pred == 0xF) {
2460     // Ambiguous with RFE and SRS
2461     switch (Inst.getOpcode()) {
2462       case ARM::LDMDA:
2463         Inst.setOpcode(ARM::RFEDA);
2464         break;
2465       case ARM::LDMDA_UPD:
2466         Inst.setOpcode(ARM::RFEDA_UPD);
2467         break;
2468       case ARM::LDMDB:
2469         Inst.setOpcode(ARM::RFEDB);
2470         break;
2471       case ARM::LDMDB_UPD:
2472         Inst.setOpcode(ARM::RFEDB_UPD);
2473         break;
2474       case ARM::LDMIA:
2475         Inst.setOpcode(ARM::RFEIA);
2476         break;
2477       case ARM::LDMIA_UPD:
2478         Inst.setOpcode(ARM::RFEIA_UPD);
2479         break;
2480       case ARM::LDMIB:
2481         Inst.setOpcode(ARM::RFEIB);
2482         break;
2483       case ARM::LDMIB_UPD:
2484         Inst.setOpcode(ARM::RFEIB_UPD);
2485         break;
2486       case ARM::STMDA:
2487         Inst.setOpcode(ARM::SRSDA);
2488         break;
2489       case ARM::STMDA_UPD:
2490         Inst.setOpcode(ARM::SRSDA_UPD);
2491         break;
2492       case ARM::STMDB:
2493         Inst.setOpcode(ARM::SRSDB);
2494         break;
2495       case ARM::STMDB_UPD:
2496         Inst.setOpcode(ARM::SRSDB_UPD);
2497         break;
2498       case ARM::STMIA:
2499         Inst.setOpcode(ARM::SRSIA);
2500         break;
2501       case ARM::STMIA_UPD:
2502         Inst.setOpcode(ARM::SRSIA_UPD);
2503         break;
2504       case ARM::STMIB:
2505         Inst.setOpcode(ARM::SRSIB);
2506         break;
2507       case ARM::STMIB_UPD:
2508         Inst.setOpcode(ARM::SRSIB_UPD);
2509         break;
2510       default:
2511         return MCDisassembler::Fail;
2512     }
2513 
2514     // For stores (which become SRS's, the only operand is the mode.
2515     if (fieldFromInstruction(Insn, 20, 1) == 0) {
2516       // Check SRS encoding constraints
2517       if (!(fieldFromInstruction(Insn, 22, 1) == 1 &&
2518             fieldFromInstruction(Insn, 20, 1) == 0))
2519         return MCDisassembler::Fail;
2520 
2521       Inst.addOperand(
2522           MCOperand::createImm(fieldFromInstruction(Insn, 0, 4)));
2523       return S;
2524     }
2525 
2526     return DecodeRFEInstruction(Inst, Insn, Address, Decoder);
2527   }
2528 
2529   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2530     return MCDisassembler::Fail;
2531   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2532     return MCDisassembler::Fail; // Tied
2533   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2534     return MCDisassembler::Fail;
2535   if (!Check(S, DecodeRegListOperand(Inst, reglist, Address, Decoder)))
2536     return MCDisassembler::Fail;
2537 
2538   return S;
2539 }
2540 
2541 // Check for UNPREDICTABLE predicated ESB instruction
2542 static DecodeStatus DecodeHINTInstruction(MCInst &Inst, unsigned Insn,
2543                                           uint64_t Address,
2544                                           const MCDisassembler *Decoder) {
2545   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2546   unsigned imm8 = fieldFromInstruction(Insn, 0, 8);
2547   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
2548   const FeatureBitset &FeatureBits = Dis->getSubtargetInfo().getFeatureBits();
2549 
2550   DecodeStatus S = MCDisassembler::Success;
2551 
2552   Inst.addOperand(MCOperand::createImm(imm8));
2553 
2554   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2555     return MCDisassembler::Fail;
2556 
2557   // ESB is unpredictable if pred != AL. Without the RAS extension, it is a NOP,
2558   // so all predicates should be allowed.
2559   if (imm8 == 0x10 && pred != 0xe && ((FeatureBits[ARM::FeatureRAS]) != 0))
2560     S = MCDisassembler::SoftFail;
2561 
2562   return S;
2563 }
2564 
2565 static DecodeStatus DecodeCPSInstruction(MCInst &Inst, unsigned Insn,
2566                                          uint64_t Address,
2567                                          const MCDisassembler *Decoder) {
2568   unsigned imod = fieldFromInstruction(Insn, 18, 2);
2569   unsigned M = fieldFromInstruction(Insn, 17, 1);
2570   unsigned iflags = fieldFromInstruction(Insn, 6, 3);
2571   unsigned mode = fieldFromInstruction(Insn, 0, 5);
2572 
2573   DecodeStatus S = MCDisassembler::Success;
2574 
2575   // This decoder is called from multiple location that do not check
2576   // the full encoding is valid before they do.
2577   if (fieldFromInstruction(Insn, 5, 1) != 0 ||
2578       fieldFromInstruction(Insn, 16, 1) != 0 ||
2579       fieldFromInstruction(Insn, 20, 8) != 0x10)
2580     return MCDisassembler::Fail;
2581 
2582   // imod == '01' --> UNPREDICTABLE
2583   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
2584   // return failure here.  The '01' imod value is unprintable, so there's
2585   // nothing useful we could do even if we returned UNPREDICTABLE.
2586 
2587   if (imod == 1) return MCDisassembler::Fail;
2588 
2589   if (imod && M) {
2590     Inst.setOpcode(ARM::CPS3p);
2591     Inst.addOperand(MCOperand::createImm(imod));
2592     Inst.addOperand(MCOperand::createImm(iflags));
2593     Inst.addOperand(MCOperand::createImm(mode));
2594   } else if (imod && !M) {
2595     Inst.setOpcode(ARM::CPS2p);
2596     Inst.addOperand(MCOperand::createImm(imod));
2597     Inst.addOperand(MCOperand::createImm(iflags));
2598     if (mode) S = MCDisassembler::SoftFail;
2599   } else if (!imod && M) {
2600     Inst.setOpcode(ARM::CPS1p);
2601     Inst.addOperand(MCOperand::createImm(mode));
2602     if (iflags) S = MCDisassembler::SoftFail;
2603   } else {
2604     // imod == '00' && M == '0' --> UNPREDICTABLE
2605     Inst.setOpcode(ARM::CPS1p);
2606     Inst.addOperand(MCOperand::createImm(mode));
2607     S = MCDisassembler::SoftFail;
2608   }
2609 
2610   return S;
2611 }
2612 
2613 static DecodeStatus DecodeT2CPSInstruction(MCInst &Inst, unsigned Insn,
2614                                            uint64_t Address,
2615                                            const MCDisassembler *Decoder) {
2616   unsigned imod = fieldFromInstruction(Insn, 9, 2);
2617   unsigned M = fieldFromInstruction(Insn, 8, 1);
2618   unsigned iflags = fieldFromInstruction(Insn, 5, 3);
2619   unsigned mode = fieldFromInstruction(Insn, 0, 5);
2620 
2621   DecodeStatus S = MCDisassembler::Success;
2622 
2623   // imod == '01' --> UNPREDICTABLE
2624   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
2625   // return failure here.  The '01' imod value is unprintable, so there's
2626   // nothing useful we could do even if we returned UNPREDICTABLE.
2627 
2628   if (imod == 1) return MCDisassembler::Fail;
2629 
2630   if (imod && M) {
2631     Inst.setOpcode(ARM::t2CPS3p);
2632     Inst.addOperand(MCOperand::createImm(imod));
2633     Inst.addOperand(MCOperand::createImm(iflags));
2634     Inst.addOperand(MCOperand::createImm(mode));
2635   } else if (imod && !M) {
2636     Inst.setOpcode(ARM::t2CPS2p);
2637     Inst.addOperand(MCOperand::createImm(imod));
2638     Inst.addOperand(MCOperand::createImm(iflags));
2639     if (mode) S = MCDisassembler::SoftFail;
2640   } else if (!imod && M) {
2641     Inst.setOpcode(ARM::t2CPS1p);
2642     Inst.addOperand(MCOperand::createImm(mode));
2643     if (iflags) S = MCDisassembler::SoftFail;
2644   } else {
2645     // imod == '00' && M == '0' --> this is a HINT instruction
2646     int imm = fieldFromInstruction(Insn, 0, 8);
2647     // HINT are defined only for immediate in [0..4]
2648     if(imm > 4) return MCDisassembler::Fail;
2649     Inst.setOpcode(ARM::t2HINT);
2650     Inst.addOperand(MCOperand::createImm(imm));
2651   }
2652 
2653   return S;
2654 }
2655 
2656 static DecodeStatus
2657 DecodeT2HintSpaceInstruction(MCInst &Inst, unsigned Insn, uint64_t Address,
2658                              const MCDisassembler *Decoder) {
2659   unsigned imm = fieldFromInstruction(Insn, 0, 8);
2660 
2661   unsigned Opcode = ARM::t2HINT;
2662 
2663   if (imm == 0x0D) {
2664     Opcode = ARM::t2PACBTI;
2665   } else if (imm == 0x1D) {
2666     Opcode = ARM::t2PAC;
2667   } else if (imm == 0x2D) {
2668     Opcode = ARM::t2AUT;
2669   } else if (imm == 0x0F) {
2670     Opcode = ARM::t2BTI;
2671   }
2672 
2673   Inst.setOpcode(Opcode);
2674   if (Opcode == ARM::t2HINT) {
2675     Inst.addOperand(MCOperand::createImm(imm));
2676   }
2677 
2678   return MCDisassembler::Success;
2679 }
2680 
2681 static DecodeStatus DecodeT2MOVTWInstruction(MCInst &Inst, unsigned Insn,
2682                                              uint64_t Address,
2683                                              const MCDisassembler *Decoder) {
2684   DecodeStatus S = MCDisassembler::Success;
2685 
2686   unsigned Rd = fieldFromInstruction(Insn, 8, 4);
2687   unsigned imm = 0;
2688 
2689   imm |= (fieldFromInstruction(Insn, 0, 8) << 0);
2690   imm |= (fieldFromInstruction(Insn, 12, 3) << 8);
2691   imm |= (fieldFromInstruction(Insn, 16, 4) << 12);
2692   imm |= (fieldFromInstruction(Insn, 26, 1) << 11);
2693 
2694   if (Inst.getOpcode() == ARM::t2MOVTi16)
2695     if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
2696       return MCDisassembler::Fail;
2697   if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
2698     return MCDisassembler::Fail;
2699 
2700   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
2701     Inst.addOperand(MCOperand::createImm(imm));
2702 
2703   return S;
2704 }
2705 
2706 static DecodeStatus DecodeArmMOVTWInstruction(MCInst &Inst, unsigned Insn,
2707                                               uint64_t Address,
2708                                               const MCDisassembler *Decoder) {
2709   DecodeStatus S = MCDisassembler::Success;
2710 
2711   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2712   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2713   unsigned imm = 0;
2714 
2715   imm |= (fieldFromInstruction(Insn, 0, 12) << 0);
2716   imm |= (fieldFromInstruction(Insn, 16, 4) << 12);
2717 
2718   if (Inst.getOpcode() == ARM::MOVTi16)
2719     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2720       return MCDisassembler::Fail;
2721 
2722   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2723     return MCDisassembler::Fail;
2724 
2725   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
2726     Inst.addOperand(MCOperand::createImm(imm));
2727 
2728   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2729     return MCDisassembler::Fail;
2730 
2731   return S;
2732 }
2733 
2734 static DecodeStatus DecodeSMLAInstruction(MCInst &Inst, unsigned Insn,
2735                                           uint64_t Address,
2736                                           const MCDisassembler *Decoder) {
2737   DecodeStatus S = MCDisassembler::Success;
2738 
2739   unsigned Rd = fieldFromInstruction(Insn, 16, 4);
2740   unsigned Rn = fieldFromInstruction(Insn, 0, 4);
2741   unsigned Rm = fieldFromInstruction(Insn, 8, 4);
2742   unsigned Ra = fieldFromInstruction(Insn, 12, 4);
2743   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2744 
2745   if (pred == 0xF)
2746     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
2747 
2748   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2749     return MCDisassembler::Fail;
2750   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
2751     return MCDisassembler::Fail;
2752   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
2753     return MCDisassembler::Fail;
2754   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Ra, Address, Decoder)))
2755     return MCDisassembler::Fail;
2756 
2757   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2758     return MCDisassembler::Fail;
2759 
2760   return S;
2761 }
2762 
2763 static DecodeStatus DecodeTSTInstruction(MCInst &Inst, unsigned Insn,
2764                                          uint64_t Address,
2765                                          const MCDisassembler *Decoder) {
2766   DecodeStatus S = MCDisassembler::Success;
2767 
2768   unsigned Pred = fieldFromInstruction(Insn, 28, 4);
2769   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2770   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2771 
2772   if (Pred == 0xF)
2773     return DecodeSETPANInstruction(Inst, Insn, Address, Decoder);
2774 
2775   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2776     return MCDisassembler::Fail;
2777   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2778     return MCDisassembler::Fail;
2779   if (!Check(S, DecodePredicateOperand(Inst, Pred, Address, Decoder)))
2780     return MCDisassembler::Fail;
2781 
2782   return S;
2783 }
2784 
2785 static DecodeStatus DecodeSETPANInstruction(MCInst &Inst, unsigned Insn,
2786                                             uint64_t Address,
2787                                             const MCDisassembler *Decoder) {
2788   DecodeStatus S = MCDisassembler::Success;
2789 
2790   unsigned Imm = fieldFromInstruction(Insn, 9, 1);
2791 
2792   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
2793   const FeatureBitset &FeatureBits = Dis->getSubtargetInfo().getFeatureBits();
2794 
2795   if (!FeatureBits[ARM::HasV8_1aOps] ||
2796       !FeatureBits[ARM::HasV8Ops])
2797     return MCDisassembler::Fail;
2798 
2799   // Decoder can be called from DecodeTST, which does not check the full
2800   // encoding is valid.
2801   if (fieldFromInstruction(Insn, 20,12) != 0xf11 ||
2802       fieldFromInstruction(Insn, 4,4) != 0)
2803     return MCDisassembler::Fail;
2804   if (fieldFromInstruction(Insn, 10,10) != 0 ||
2805       fieldFromInstruction(Insn, 0,4) != 0)
2806     S = MCDisassembler::SoftFail;
2807 
2808   Inst.setOpcode(ARM::SETPAN);
2809   Inst.addOperand(MCOperand::createImm(Imm));
2810 
2811   return S;
2812 }
2813 
2814 static DecodeStatus DecodeAddrModeImm12Operand(MCInst &Inst, unsigned Val,
2815                                                uint64_t Address,
2816                                                const MCDisassembler *Decoder) {
2817   DecodeStatus S = MCDisassembler::Success;
2818 
2819   unsigned add = fieldFromInstruction(Val, 12, 1);
2820   unsigned imm = fieldFromInstruction(Val, 0, 12);
2821   unsigned Rn = fieldFromInstruction(Val, 13, 4);
2822 
2823   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2824     return MCDisassembler::Fail;
2825 
2826   if (!add) imm *= -1;
2827   if (imm == 0 && !add) imm = INT32_MIN;
2828   Inst.addOperand(MCOperand::createImm(imm));
2829   if (Rn == 15)
2830     tryAddingPcLoadReferenceComment(Address, Address + imm + 8, Decoder);
2831 
2832   return S;
2833 }
2834 
2835 static DecodeStatus DecodeAddrMode5Operand(MCInst &Inst, unsigned Val,
2836                                            uint64_t Address,
2837                                            const MCDisassembler *Decoder) {
2838   DecodeStatus S = MCDisassembler::Success;
2839 
2840   unsigned Rn = fieldFromInstruction(Val, 9, 4);
2841   // U == 1 to add imm, 0 to subtract it.
2842   unsigned U = fieldFromInstruction(Val, 8, 1);
2843   unsigned imm = fieldFromInstruction(Val, 0, 8);
2844 
2845   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2846     return MCDisassembler::Fail;
2847 
2848   if (U)
2849     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5Opc(ARM_AM::add, imm)));
2850   else
2851     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5Opc(ARM_AM::sub, imm)));
2852 
2853   return S;
2854 }
2855 
2856 static DecodeStatus DecodeAddrMode5FP16Operand(MCInst &Inst, unsigned Val,
2857                                                uint64_t Address,
2858                                                const MCDisassembler *Decoder) {
2859   DecodeStatus S = MCDisassembler::Success;
2860 
2861   unsigned Rn = fieldFromInstruction(Val, 9, 4);
2862   // U == 1 to add imm, 0 to subtract it.
2863   unsigned U = fieldFromInstruction(Val, 8, 1);
2864   unsigned imm = fieldFromInstruction(Val, 0, 8);
2865 
2866   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2867     return MCDisassembler::Fail;
2868 
2869   if (U)
2870     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5FP16Opc(ARM_AM::add, imm)));
2871   else
2872     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5FP16Opc(ARM_AM::sub, imm)));
2873 
2874   return S;
2875 }
2876 
2877 static DecodeStatus DecodeAddrMode7Operand(MCInst &Inst, unsigned Val,
2878                                            uint64_t Address,
2879                                            const MCDisassembler *Decoder) {
2880   return DecodeGPRRegisterClass(Inst, Val, Address, Decoder);
2881 }
2882 
2883 static DecodeStatus DecodeT2BInstruction(MCInst &Inst, unsigned Insn,
2884                                          uint64_t Address,
2885                                          const MCDisassembler *Decoder) {
2886   DecodeStatus Status = MCDisassembler::Success;
2887 
2888   // Note the J1 and J2 values are from the encoded instruction.  So here
2889   // change them to I1 and I2 values via as documented:
2890   // I1 = NOT(J1 EOR S);
2891   // I2 = NOT(J2 EOR S);
2892   // and build the imm32 with one trailing zero as documented:
2893   // imm32 = SignExtend(S:I1:I2:imm10:imm11:'0', 32);
2894   unsigned S = fieldFromInstruction(Insn, 26, 1);
2895   unsigned J1 = fieldFromInstruction(Insn, 13, 1);
2896   unsigned J2 = fieldFromInstruction(Insn, 11, 1);
2897   unsigned I1 = !(J1 ^ S);
2898   unsigned I2 = !(J2 ^ S);
2899   unsigned imm10 = fieldFromInstruction(Insn, 16, 10);
2900   unsigned imm11 = fieldFromInstruction(Insn, 0, 11);
2901   unsigned tmp = (S << 23) | (I1 << 22) | (I2 << 21) | (imm10 << 11) | imm11;
2902   int imm32 = SignExtend32<25>(tmp << 1);
2903   if (!tryAddingSymbolicOperand(Address, Address + imm32 + 4,
2904                                 true, 4, Inst, Decoder))
2905     Inst.addOperand(MCOperand::createImm(imm32));
2906 
2907   return Status;
2908 }
2909 
2910 static DecodeStatus DecodeBranchImmInstruction(MCInst &Inst, unsigned Insn,
2911                                                uint64_t Address,
2912                                                const MCDisassembler *Decoder) {
2913   DecodeStatus S = MCDisassembler::Success;
2914 
2915   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2916   unsigned imm = fieldFromInstruction(Insn, 0, 24) << 2;
2917 
2918   if (pred == 0xF) {
2919     Inst.setOpcode(ARM::BLXi);
2920     imm |= fieldFromInstruction(Insn, 24, 1) << 1;
2921     if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<26>(imm) + 8,
2922                                   true, 4, Inst, Decoder))
2923     Inst.addOperand(MCOperand::createImm(SignExtend32<26>(imm)));
2924     return S;
2925   }
2926 
2927   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<26>(imm) + 8,
2928                                 true, 4, Inst, Decoder))
2929     Inst.addOperand(MCOperand::createImm(SignExtend32<26>(imm)));
2930 
2931   // We already have BL_pred for BL w/ predicate, no need to add addition
2932   // predicate opreands for BL
2933   if (Inst.getOpcode() != ARM::BL)
2934     if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2935       return MCDisassembler::Fail;
2936 
2937   return S;
2938 }
2939 
2940 static DecodeStatus DecodeAddrMode6Operand(MCInst &Inst, unsigned Val,
2941                                            uint64_t Address,
2942                                            const MCDisassembler *Decoder) {
2943   DecodeStatus S = MCDisassembler::Success;
2944 
2945   unsigned Rm = fieldFromInstruction(Val, 0, 4);
2946   unsigned align = fieldFromInstruction(Val, 4, 2);
2947 
2948   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2949     return MCDisassembler::Fail;
2950   if (!align)
2951     Inst.addOperand(MCOperand::createImm(0));
2952   else
2953     Inst.addOperand(MCOperand::createImm(4 << align));
2954 
2955   return S;
2956 }
2957 
2958 static DecodeStatus DecodeVLDInstruction(MCInst &Inst, unsigned Insn,
2959                                          uint64_t Address,
2960                                          const MCDisassembler *Decoder) {
2961   DecodeStatus S = MCDisassembler::Success;
2962 
2963   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2964   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
2965   unsigned wb = fieldFromInstruction(Insn, 16, 4);
2966   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2967   Rn |= fieldFromInstruction(Insn, 4, 2) << 4;
2968   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2969 
2970   // First output register
2971   switch (Inst.getOpcode()) {
2972   case ARM::VLD1q16: case ARM::VLD1q32: case ARM::VLD1q64: case ARM::VLD1q8:
2973   case ARM::VLD1q16wb_fixed: case ARM::VLD1q16wb_register:
2974   case ARM::VLD1q32wb_fixed: case ARM::VLD1q32wb_register:
2975   case ARM::VLD1q64wb_fixed: case ARM::VLD1q64wb_register:
2976   case ARM::VLD1q8wb_fixed: case ARM::VLD1q8wb_register:
2977   case ARM::VLD2d16: case ARM::VLD2d32: case ARM::VLD2d8:
2978   case ARM::VLD2d16wb_fixed: case ARM::VLD2d16wb_register:
2979   case ARM::VLD2d32wb_fixed: case ARM::VLD2d32wb_register:
2980   case ARM::VLD2d8wb_fixed: case ARM::VLD2d8wb_register:
2981     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
2982       return MCDisassembler::Fail;
2983     break;
2984   case ARM::VLD2b16:
2985   case ARM::VLD2b32:
2986   case ARM::VLD2b8:
2987   case ARM::VLD2b16wb_fixed:
2988   case ARM::VLD2b16wb_register:
2989   case ARM::VLD2b32wb_fixed:
2990   case ARM::VLD2b32wb_register:
2991   case ARM::VLD2b8wb_fixed:
2992   case ARM::VLD2b8wb_register:
2993     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
2994       return MCDisassembler::Fail;
2995     break;
2996   default:
2997     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2998       return MCDisassembler::Fail;
2999   }
3000 
3001   // Second output register
3002   switch (Inst.getOpcode()) {
3003     case ARM::VLD3d8:
3004     case ARM::VLD3d16:
3005     case ARM::VLD3d32:
3006     case ARM::VLD3d8_UPD:
3007     case ARM::VLD3d16_UPD:
3008     case ARM::VLD3d32_UPD:
3009     case ARM::VLD4d8:
3010     case ARM::VLD4d16:
3011     case ARM::VLD4d32:
3012     case ARM::VLD4d8_UPD:
3013     case ARM::VLD4d16_UPD:
3014     case ARM::VLD4d32_UPD:
3015       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
3016         return MCDisassembler::Fail;
3017       break;
3018     case ARM::VLD3q8:
3019     case ARM::VLD3q16:
3020     case ARM::VLD3q32:
3021     case ARM::VLD3q8_UPD:
3022     case ARM::VLD3q16_UPD:
3023     case ARM::VLD3q32_UPD:
3024     case ARM::VLD4q8:
3025     case ARM::VLD4q16:
3026     case ARM::VLD4q32:
3027     case ARM::VLD4q8_UPD:
3028     case ARM::VLD4q16_UPD:
3029     case ARM::VLD4q32_UPD:
3030       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
3031         return MCDisassembler::Fail;
3032       break;
3033     default:
3034       break;
3035   }
3036 
3037   // Third output register
3038   switch(Inst.getOpcode()) {
3039     case ARM::VLD3d8:
3040     case ARM::VLD3d16:
3041     case ARM::VLD3d32:
3042     case ARM::VLD3d8_UPD:
3043     case ARM::VLD3d16_UPD:
3044     case ARM::VLD3d32_UPD:
3045     case ARM::VLD4d8:
3046     case ARM::VLD4d16:
3047     case ARM::VLD4d32:
3048     case ARM::VLD4d8_UPD:
3049     case ARM::VLD4d16_UPD:
3050     case ARM::VLD4d32_UPD:
3051       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
3052         return MCDisassembler::Fail;
3053       break;
3054     case ARM::VLD3q8:
3055     case ARM::VLD3q16:
3056     case ARM::VLD3q32:
3057     case ARM::VLD3q8_UPD:
3058     case ARM::VLD3q16_UPD:
3059     case ARM::VLD3q32_UPD:
3060     case ARM::VLD4q8:
3061     case ARM::VLD4q16:
3062     case ARM::VLD4q32:
3063     case ARM::VLD4q8_UPD:
3064     case ARM::VLD4q16_UPD:
3065     case ARM::VLD4q32_UPD:
3066       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
3067         return MCDisassembler::Fail;
3068       break;
3069     default:
3070       break;
3071   }
3072 
3073   // Fourth output register
3074   switch (Inst.getOpcode()) {
3075     case ARM::VLD4d8:
3076     case ARM::VLD4d16:
3077     case ARM::VLD4d32:
3078     case ARM::VLD4d8_UPD:
3079     case ARM::VLD4d16_UPD:
3080     case ARM::VLD4d32_UPD:
3081       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
3082         return MCDisassembler::Fail;
3083       break;
3084     case ARM::VLD4q8:
3085     case ARM::VLD4q16:
3086     case ARM::VLD4q32:
3087     case ARM::VLD4q8_UPD:
3088     case ARM::VLD4q16_UPD:
3089     case ARM::VLD4q32_UPD:
3090       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
3091         return MCDisassembler::Fail;
3092       break;
3093     default:
3094       break;
3095   }
3096 
3097   // Writeback operand
3098   switch (Inst.getOpcode()) {
3099     case ARM::VLD1d8wb_fixed:
3100     case ARM::VLD1d16wb_fixed:
3101     case ARM::VLD1d32wb_fixed:
3102     case ARM::VLD1d64wb_fixed:
3103     case ARM::VLD1d8wb_register:
3104     case ARM::VLD1d16wb_register:
3105     case ARM::VLD1d32wb_register:
3106     case ARM::VLD1d64wb_register:
3107     case ARM::VLD1q8wb_fixed:
3108     case ARM::VLD1q16wb_fixed:
3109     case ARM::VLD1q32wb_fixed:
3110     case ARM::VLD1q64wb_fixed:
3111     case ARM::VLD1q8wb_register:
3112     case ARM::VLD1q16wb_register:
3113     case ARM::VLD1q32wb_register:
3114     case ARM::VLD1q64wb_register:
3115     case ARM::VLD1d8Twb_fixed:
3116     case ARM::VLD1d8Twb_register:
3117     case ARM::VLD1d16Twb_fixed:
3118     case ARM::VLD1d16Twb_register:
3119     case ARM::VLD1d32Twb_fixed:
3120     case ARM::VLD1d32Twb_register:
3121     case ARM::VLD1d64Twb_fixed:
3122     case ARM::VLD1d64Twb_register:
3123     case ARM::VLD1d8Qwb_fixed:
3124     case ARM::VLD1d8Qwb_register:
3125     case ARM::VLD1d16Qwb_fixed:
3126     case ARM::VLD1d16Qwb_register:
3127     case ARM::VLD1d32Qwb_fixed:
3128     case ARM::VLD1d32Qwb_register:
3129     case ARM::VLD1d64Qwb_fixed:
3130     case ARM::VLD1d64Qwb_register:
3131     case ARM::VLD2d8wb_fixed:
3132     case ARM::VLD2d16wb_fixed:
3133     case ARM::VLD2d32wb_fixed:
3134     case ARM::VLD2q8wb_fixed:
3135     case ARM::VLD2q16wb_fixed:
3136     case ARM::VLD2q32wb_fixed:
3137     case ARM::VLD2d8wb_register:
3138     case ARM::VLD2d16wb_register:
3139     case ARM::VLD2d32wb_register:
3140     case ARM::VLD2q8wb_register:
3141     case ARM::VLD2q16wb_register:
3142     case ARM::VLD2q32wb_register:
3143     case ARM::VLD2b8wb_fixed:
3144     case ARM::VLD2b16wb_fixed:
3145     case ARM::VLD2b32wb_fixed:
3146     case ARM::VLD2b8wb_register:
3147     case ARM::VLD2b16wb_register:
3148     case ARM::VLD2b32wb_register:
3149       Inst.addOperand(MCOperand::createImm(0));
3150       break;
3151     case ARM::VLD3d8_UPD:
3152     case ARM::VLD3d16_UPD:
3153     case ARM::VLD3d32_UPD:
3154     case ARM::VLD3q8_UPD:
3155     case ARM::VLD3q16_UPD:
3156     case ARM::VLD3q32_UPD:
3157     case ARM::VLD4d8_UPD:
3158     case ARM::VLD4d16_UPD:
3159     case ARM::VLD4d32_UPD:
3160     case ARM::VLD4q8_UPD:
3161     case ARM::VLD4q16_UPD:
3162     case ARM::VLD4q32_UPD:
3163       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
3164         return MCDisassembler::Fail;
3165       break;
3166     default:
3167       break;
3168   }
3169 
3170   // AddrMode6 Base (register+alignment)
3171   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
3172     return MCDisassembler::Fail;
3173 
3174   // AddrMode6 Offset (register)
3175   switch (Inst.getOpcode()) {
3176   default:
3177     // The below have been updated to have explicit am6offset split
3178     // between fixed and register offset. For those instructions not
3179     // yet updated, we need to add an additional reg0 operand for the
3180     // fixed variant.
3181     //
3182     // The fixed offset encodes as Rm == 0xd, so we check for that.
3183     if (Rm == 0xd) {
3184       Inst.addOperand(MCOperand::createReg(0));
3185       break;
3186     }
3187     // Fall through to handle the register offset variant.
3188     LLVM_FALLTHROUGH;
3189   case ARM::VLD1d8wb_fixed:
3190   case ARM::VLD1d16wb_fixed:
3191   case ARM::VLD1d32wb_fixed:
3192   case ARM::VLD1d64wb_fixed:
3193   case ARM::VLD1d8Twb_fixed:
3194   case ARM::VLD1d16Twb_fixed:
3195   case ARM::VLD1d32Twb_fixed:
3196   case ARM::VLD1d64Twb_fixed:
3197   case ARM::VLD1d8Qwb_fixed:
3198   case ARM::VLD1d16Qwb_fixed:
3199   case ARM::VLD1d32Qwb_fixed:
3200   case ARM::VLD1d64Qwb_fixed:
3201   case ARM::VLD1d8wb_register:
3202   case ARM::VLD1d16wb_register:
3203   case ARM::VLD1d32wb_register:
3204   case ARM::VLD1d64wb_register:
3205   case ARM::VLD1q8wb_fixed:
3206   case ARM::VLD1q16wb_fixed:
3207   case ARM::VLD1q32wb_fixed:
3208   case ARM::VLD1q64wb_fixed:
3209   case ARM::VLD1q8wb_register:
3210   case ARM::VLD1q16wb_register:
3211   case ARM::VLD1q32wb_register:
3212   case ARM::VLD1q64wb_register:
3213     // The fixed offset post-increment encodes Rm == 0xd. The no-writeback
3214     // variant encodes Rm == 0xf. Anything else is a register offset post-
3215     // increment and we need to add the register operand to the instruction.
3216     if (Rm != 0xD && Rm != 0xF &&
3217         !Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3218       return MCDisassembler::Fail;
3219     break;
3220   case ARM::VLD2d8wb_fixed:
3221   case ARM::VLD2d16wb_fixed:
3222   case ARM::VLD2d32wb_fixed:
3223   case ARM::VLD2b8wb_fixed:
3224   case ARM::VLD2b16wb_fixed:
3225   case ARM::VLD2b32wb_fixed:
3226   case ARM::VLD2q8wb_fixed:
3227   case ARM::VLD2q16wb_fixed:
3228   case ARM::VLD2q32wb_fixed:
3229     break;
3230   }
3231 
3232   return S;
3233 }
3234 
3235 static DecodeStatus DecodeVLDST1Instruction(MCInst &Inst, unsigned Insn,
3236                                             uint64_t Address,
3237                                             const MCDisassembler *Decoder) {
3238   unsigned type = fieldFromInstruction(Insn, 8, 4);
3239   unsigned align = fieldFromInstruction(Insn, 4, 2);
3240   if (type == 6 && (align & 2)) return MCDisassembler::Fail;
3241   if (type == 7 && (align & 2)) return MCDisassembler::Fail;
3242   if (type == 10 && align == 3) return MCDisassembler::Fail;
3243 
3244   unsigned load = fieldFromInstruction(Insn, 21, 1);
3245   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
3246               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
3247 }
3248 
3249 static DecodeStatus DecodeVLDST2Instruction(MCInst &Inst, unsigned Insn,
3250                                             uint64_t Address,
3251                                             const MCDisassembler *Decoder) {
3252   unsigned size = fieldFromInstruction(Insn, 6, 2);
3253   if (size == 3) return MCDisassembler::Fail;
3254 
3255   unsigned type = fieldFromInstruction(Insn, 8, 4);
3256   unsigned align = fieldFromInstruction(Insn, 4, 2);
3257   if (type == 8 && align == 3) return MCDisassembler::Fail;
3258   if (type == 9 && align == 3) return MCDisassembler::Fail;
3259 
3260   unsigned load = fieldFromInstruction(Insn, 21, 1);
3261   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
3262               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
3263 }
3264 
3265 static DecodeStatus DecodeVLDST3Instruction(MCInst &Inst, unsigned Insn,
3266                                             uint64_t Address,
3267                                             const MCDisassembler *Decoder) {
3268   unsigned size = fieldFromInstruction(Insn, 6, 2);
3269   if (size == 3) return MCDisassembler::Fail;
3270 
3271   unsigned align = fieldFromInstruction(Insn, 4, 2);
3272   if (align & 2) return MCDisassembler::Fail;
3273 
3274   unsigned load = fieldFromInstruction(Insn, 21, 1);
3275   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
3276               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
3277 }
3278 
3279 static DecodeStatus DecodeVLDST4Instruction(MCInst &Inst, unsigned Insn,
3280                                             uint64_t Address,
3281                                             const MCDisassembler *Decoder) {
3282   unsigned size = fieldFromInstruction(Insn, 6, 2);
3283   if (size == 3) return MCDisassembler::Fail;
3284 
3285   unsigned load = fieldFromInstruction(Insn, 21, 1);
3286   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
3287               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
3288 }
3289 
3290 static DecodeStatus DecodeVSTInstruction(MCInst &Inst, unsigned Insn,
3291                                          uint64_t Address,
3292                                          const MCDisassembler *Decoder) {
3293   DecodeStatus S = MCDisassembler::Success;
3294 
3295   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3296   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3297   unsigned wb = fieldFromInstruction(Insn, 16, 4);
3298   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3299   Rn |= fieldFromInstruction(Insn, 4, 2) << 4;
3300   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3301 
3302   // Writeback Operand
3303   switch (Inst.getOpcode()) {
3304     case ARM::VST1d8wb_fixed:
3305     case ARM::VST1d16wb_fixed:
3306     case ARM::VST1d32wb_fixed:
3307     case ARM::VST1d64wb_fixed:
3308     case ARM::VST1d8wb_register:
3309     case ARM::VST1d16wb_register:
3310     case ARM::VST1d32wb_register:
3311     case ARM::VST1d64wb_register:
3312     case ARM::VST1q8wb_fixed:
3313     case ARM::VST1q16wb_fixed:
3314     case ARM::VST1q32wb_fixed:
3315     case ARM::VST1q64wb_fixed:
3316     case ARM::VST1q8wb_register:
3317     case ARM::VST1q16wb_register:
3318     case ARM::VST1q32wb_register:
3319     case ARM::VST1q64wb_register:
3320     case ARM::VST1d8Twb_fixed:
3321     case ARM::VST1d16Twb_fixed:
3322     case ARM::VST1d32Twb_fixed:
3323     case ARM::VST1d64Twb_fixed:
3324     case ARM::VST1d8Twb_register:
3325     case ARM::VST1d16Twb_register:
3326     case ARM::VST1d32Twb_register:
3327     case ARM::VST1d64Twb_register:
3328     case ARM::VST1d8Qwb_fixed:
3329     case ARM::VST1d16Qwb_fixed:
3330     case ARM::VST1d32Qwb_fixed:
3331     case ARM::VST1d64Qwb_fixed:
3332     case ARM::VST1d8Qwb_register:
3333     case ARM::VST1d16Qwb_register:
3334     case ARM::VST1d32Qwb_register:
3335     case ARM::VST1d64Qwb_register:
3336     case ARM::VST2d8wb_fixed:
3337     case ARM::VST2d16wb_fixed:
3338     case ARM::VST2d32wb_fixed:
3339     case ARM::VST2d8wb_register:
3340     case ARM::VST2d16wb_register:
3341     case ARM::VST2d32wb_register:
3342     case ARM::VST2q8wb_fixed:
3343     case ARM::VST2q16wb_fixed:
3344     case ARM::VST2q32wb_fixed:
3345     case ARM::VST2q8wb_register:
3346     case ARM::VST2q16wb_register:
3347     case ARM::VST2q32wb_register:
3348     case ARM::VST2b8wb_fixed:
3349     case ARM::VST2b16wb_fixed:
3350     case ARM::VST2b32wb_fixed:
3351     case ARM::VST2b8wb_register:
3352     case ARM::VST2b16wb_register:
3353     case ARM::VST2b32wb_register:
3354       if (Rm == 0xF)
3355         return MCDisassembler::Fail;
3356       Inst.addOperand(MCOperand::createImm(0));
3357       break;
3358     case ARM::VST3d8_UPD:
3359     case ARM::VST3d16_UPD:
3360     case ARM::VST3d32_UPD:
3361     case ARM::VST3q8_UPD:
3362     case ARM::VST3q16_UPD:
3363     case ARM::VST3q32_UPD:
3364     case ARM::VST4d8_UPD:
3365     case ARM::VST4d16_UPD:
3366     case ARM::VST4d32_UPD:
3367     case ARM::VST4q8_UPD:
3368     case ARM::VST4q16_UPD:
3369     case ARM::VST4q32_UPD:
3370       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
3371         return MCDisassembler::Fail;
3372       break;
3373     default:
3374       break;
3375   }
3376 
3377   // AddrMode6 Base (register+alignment)
3378   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
3379     return MCDisassembler::Fail;
3380 
3381   // AddrMode6 Offset (register)
3382   switch (Inst.getOpcode()) {
3383     default:
3384       if (Rm == 0xD)
3385         Inst.addOperand(MCOperand::createReg(0));
3386       else if (Rm != 0xF) {
3387         if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3388           return MCDisassembler::Fail;
3389       }
3390       break;
3391     case ARM::VST1d8wb_fixed:
3392     case ARM::VST1d16wb_fixed:
3393     case ARM::VST1d32wb_fixed:
3394     case ARM::VST1d64wb_fixed:
3395     case ARM::VST1q8wb_fixed:
3396     case ARM::VST1q16wb_fixed:
3397     case ARM::VST1q32wb_fixed:
3398     case ARM::VST1q64wb_fixed:
3399     case ARM::VST1d8Twb_fixed:
3400     case ARM::VST1d16Twb_fixed:
3401     case ARM::VST1d32Twb_fixed:
3402     case ARM::VST1d64Twb_fixed:
3403     case ARM::VST1d8Qwb_fixed:
3404     case ARM::VST1d16Qwb_fixed:
3405     case ARM::VST1d32Qwb_fixed:
3406     case ARM::VST1d64Qwb_fixed:
3407     case ARM::VST2d8wb_fixed:
3408     case ARM::VST2d16wb_fixed:
3409     case ARM::VST2d32wb_fixed:
3410     case ARM::VST2q8wb_fixed:
3411     case ARM::VST2q16wb_fixed:
3412     case ARM::VST2q32wb_fixed:
3413     case ARM::VST2b8wb_fixed:
3414     case ARM::VST2b16wb_fixed:
3415     case ARM::VST2b32wb_fixed:
3416       break;
3417   }
3418 
3419   // First input register
3420   switch (Inst.getOpcode()) {
3421   case ARM::VST1q16:
3422   case ARM::VST1q32:
3423   case ARM::VST1q64:
3424   case ARM::VST1q8:
3425   case ARM::VST1q16wb_fixed:
3426   case ARM::VST1q16wb_register:
3427   case ARM::VST1q32wb_fixed:
3428   case ARM::VST1q32wb_register:
3429   case ARM::VST1q64wb_fixed:
3430   case ARM::VST1q64wb_register:
3431   case ARM::VST1q8wb_fixed:
3432   case ARM::VST1q8wb_register:
3433   case ARM::VST2d16:
3434   case ARM::VST2d32:
3435   case ARM::VST2d8:
3436   case ARM::VST2d16wb_fixed:
3437   case ARM::VST2d16wb_register:
3438   case ARM::VST2d32wb_fixed:
3439   case ARM::VST2d32wb_register:
3440   case ARM::VST2d8wb_fixed:
3441   case ARM::VST2d8wb_register:
3442     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3443       return MCDisassembler::Fail;
3444     break;
3445   case ARM::VST2b16:
3446   case ARM::VST2b32:
3447   case ARM::VST2b8:
3448   case ARM::VST2b16wb_fixed:
3449   case ARM::VST2b16wb_register:
3450   case ARM::VST2b32wb_fixed:
3451   case ARM::VST2b32wb_register:
3452   case ARM::VST2b8wb_fixed:
3453   case ARM::VST2b8wb_register:
3454     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
3455       return MCDisassembler::Fail;
3456     break;
3457   default:
3458     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3459       return MCDisassembler::Fail;
3460   }
3461 
3462   // Second input register
3463   switch (Inst.getOpcode()) {
3464     case ARM::VST3d8:
3465     case ARM::VST3d16:
3466     case ARM::VST3d32:
3467     case ARM::VST3d8_UPD:
3468     case ARM::VST3d16_UPD:
3469     case ARM::VST3d32_UPD:
3470     case ARM::VST4d8:
3471     case ARM::VST4d16:
3472     case ARM::VST4d32:
3473     case ARM::VST4d8_UPD:
3474     case ARM::VST4d16_UPD:
3475     case ARM::VST4d32_UPD:
3476       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
3477         return MCDisassembler::Fail;
3478       break;
3479     case ARM::VST3q8:
3480     case ARM::VST3q16:
3481     case ARM::VST3q32:
3482     case ARM::VST3q8_UPD:
3483     case ARM::VST3q16_UPD:
3484     case ARM::VST3q32_UPD:
3485     case ARM::VST4q8:
3486     case ARM::VST4q16:
3487     case ARM::VST4q32:
3488     case ARM::VST4q8_UPD:
3489     case ARM::VST4q16_UPD:
3490     case ARM::VST4q32_UPD:
3491       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
3492         return MCDisassembler::Fail;
3493       break;
3494     default:
3495       break;
3496   }
3497 
3498   // Third input register
3499   switch (Inst.getOpcode()) {
3500     case ARM::VST3d8:
3501     case ARM::VST3d16:
3502     case ARM::VST3d32:
3503     case ARM::VST3d8_UPD:
3504     case ARM::VST3d16_UPD:
3505     case ARM::VST3d32_UPD:
3506     case ARM::VST4d8:
3507     case ARM::VST4d16:
3508     case ARM::VST4d32:
3509     case ARM::VST4d8_UPD:
3510     case ARM::VST4d16_UPD:
3511     case ARM::VST4d32_UPD:
3512       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
3513         return MCDisassembler::Fail;
3514       break;
3515     case ARM::VST3q8:
3516     case ARM::VST3q16:
3517     case ARM::VST3q32:
3518     case ARM::VST3q8_UPD:
3519     case ARM::VST3q16_UPD:
3520     case ARM::VST3q32_UPD:
3521     case ARM::VST4q8:
3522     case ARM::VST4q16:
3523     case ARM::VST4q32:
3524     case ARM::VST4q8_UPD:
3525     case ARM::VST4q16_UPD:
3526     case ARM::VST4q32_UPD:
3527       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
3528         return MCDisassembler::Fail;
3529       break;
3530     default:
3531       break;
3532   }
3533 
3534   // Fourth input register
3535   switch (Inst.getOpcode()) {
3536     case ARM::VST4d8:
3537     case ARM::VST4d16:
3538     case ARM::VST4d32:
3539     case ARM::VST4d8_UPD:
3540     case ARM::VST4d16_UPD:
3541     case ARM::VST4d32_UPD:
3542       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
3543         return MCDisassembler::Fail;
3544       break;
3545     case ARM::VST4q8:
3546     case ARM::VST4q16:
3547     case ARM::VST4q32:
3548     case ARM::VST4q8_UPD:
3549     case ARM::VST4q16_UPD:
3550     case ARM::VST4q32_UPD:
3551       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
3552         return MCDisassembler::Fail;
3553       break;
3554     default:
3555       break;
3556   }
3557 
3558   return S;
3559 }
3560 
3561 static DecodeStatus DecodeVLD1DupInstruction(MCInst &Inst, unsigned Insn,
3562                                              uint64_t Address,
3563                                              const MCDisassembler *Decoder) {
3564   DecodeStatus S = MCDisassembler::Success;
3565 
3566   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3567   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3568   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3569   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3570   unsigned align = fieldFromInstruction(Insn, 4, 1);
3571   unsigned size = fieldFromInstruction(Insn, 6, 2);
3572 
3573   if (size == 0 && align == 1)
3574     return MCDisassembler::Fail;
3575   align *= (1 << size);
3576 
3577   switch (Inst.getOpcode()) {
3578   case ARM::VLD1DUPq16: case ARM::VLD1DUPq32: case ARM::VLD1DUPq8:
3579   case ARM::VLD1DUPq16wb_fixed: case ARM::VLD1DUPq16wb_register:
3580   case ARM::VLD1DUPq32wb_fixed: case ARM::VLD1DUPq32wb_register:
3581   case ARM::VLD1DUPq8wb_fixed: case ARM::VLD1DUPq8wb_register:
3582     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3583       return MCDisassembler::Fail;
3584     break;
3585   default:
3586     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3587       return MCDisassembler::Fail;
3588     break;
3589   }
3590   if (Rm != 0xF) {
3591     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3592       return MCDisassembler::Fail;
3593   }
3594 
3595   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3596     return MCDisassembler::Fail;
3597   Inst.addOperand(MCOperand::createImm(align));
3598 
3599   // The fixed offset post-increment encodes Rm == 0xd. The no-writeback
3600   // variant encodes Rm == 0xf. Anything else is a register offset post-
3601   // increment and we need to add the register operand to the instruction.
3602   if (Rm != 0xD && Rm != 0xF &&
3603       !Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3604     return MCDisassembler::Fail;
3605 
3606   return S;
3607 }
3608 
3609 static DecodeStatus DecodeVLD2DupInstruction(MCInst &Inst, unsigned Insn,
3610                                              uint64_t Address,
3611                                              const MCDisassembler *Decoder) {
3612   DecodeStatus S = MCDisassembler::Success;
3613 
3614   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3615   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3616   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3617   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3618   unsigned align = fieldFromInstruction(Insn, 4, 1);
3619   unsigned size = 1 << fieldFromInstruction(Insn, 6, 2);
3620   align *= 2*size;
3621 
3622   switch (Inst.getOpcode()) {
3623   case ARM::VLD2DUPd16: case ARM::VLD2DUPd32: case ARM::VLD2DUPd8:
3624   case ARM::VLD2DUPd16wb_fixed: case ARM::VLD2DUPd16wb_register:
3625   case ARM::VLD2DUPd32wb_fixed: case ARM::VLD2DUPd32wb_register:
3626   case ARM::VLD2DUPd8wb_fixed: case ARM::VLD2DUPd8wb_register:
3627     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3628       return MCDisassembler::Fail;
3629     break;
3630   case ARM::VLD2DUPd16x2: case ARM::VLD2DUPd32x2: case ARM::VLD2DUPd8x2:
3631   case ARM::VLD2DUPd16x2wb_fixed: case ARM::VLD2DUPd16x2wb_register:
3632   case ARM::VLD2DUPd32x2wb_fixed: case ARM::VLD2DUPd32x2wb_register:
3633   case ARM::VLD2DUPd8x2wb_fixed: case ARM::VLD2DUPd8x2wb_register:
3634     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
3635       return MCDisassembler::Fail;
3636     break;
3637   default:
3638     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3639       return MCDisassembler::Fail;
3640     break;
3641   }
3642 
3643   if (Rm != 0xF)
3644     Inst.addOperand(MCOperand::createImm(0));
3645 
3646   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3647     return MCDisassembler::Fail;
3648   Inst.addOperand(MCOperand::createImm(align));
3649 
3650   if (Rm != 0xD && Rm != 0xF) {
3651     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3652       return MCDisassembler::Fail;
3653   }
3654 
3655   return S;
3656 }
3657 
3658 static DecodeStatus DecodeVLD3DupInstruction(MCInst &Inst, unsigned Insn,
3659                                              uint64_t Address,
3660                                              const MCDisassembler *Decoder) {
3661   DecodeStatus S = MCDisassembler::Success;
3662 
3663   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3664   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3665   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3666   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3667   unsigned inc = fieldFromInstruction(Insn, 5, 1) + 1;
3668 
3669   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3670     return MCDisassembler::Fail;
3671   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
3672     return MCDisassembler::Fail;
3673   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
3674     return MCDisassembler::Fail;
3675   if (Rm != 0xF) {
3676     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3677       return MCDisassembler::Fail;
3678   }
3679 
3680   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3681     return MCDisassembler::Fail;
3682   Inst.addOperand(MCOperand::createImm(0));
3683 
3684   if (Rm == 0xD)
3685     Inst.addOperand(MCOperand::createReg(0));
3686   else if (Rm != 0xF) {
3687     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3688       return MCDisassembler::Fail;
3689   }
3690 
3691   return S;
3692 }
3693 
3694 static DecodeStatus DecodeVLD4DupInstruction(MCInst &Inst, unsigned Insn,
3695                                              uint64_t Address,
3696                                              const MCDisassembler *Decoder) {
3697   DecodeStatus S = MCDisassembler::Success;
3698 
3699   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3700   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3701   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3702   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3703   unsigned size = fieldFromInstruction(Insn, 6, 2);
3704   unsigned inc = fieldFromInstruction(Insn, 5, 1) + 1;
3705   unsigned align = fieldFromInstruction(Insn, 4, 1);
3706 
3707   if (size == 0x3) {
3708     if (align == 0)
3709       return MCDisassembler::Fail;
3710     align = 16;
3711   } else {
3712     if (size == 2) {
3713       align *= 8;
3714     } else {
3715       size = 1 << size;
3716       align *= 4*size;
3717     }
3718   }
3719 
3720   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3721     return MCDisassembler::Fail;
3722   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
3723     return MCDisassembler::Fail;
3724   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
3725     return MCDisassembler::Fail;
3726   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3*inc)%32, Address, Decoder)))
3727     return MCDisassembler::Fail;
3728   if (Rm != 0xF) {
3729     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3730       return MCDisassembler::Fail;
3731   }
3732 
3733   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3734     return MCDisassembler::Fail;
3735   Inst.addOperand(MCOperand::createImm(align));
3736 
3737   if (Rm == 0xD)
3738     Inst.addOperand(MCOperand::createReg(0));
3739   else if (Rm != 0xF) {
3740     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3741       return MCDisassembler::Fail;
3742   }
3743 
3744   return S;
3745 }
3746 
3747 static DecodeStatus DecodeVMOVModImmInstruction(MCInst &Inst, unsigned Insn,
3748                                                 uint64_t Address,
3749                                                 const MCDisassembler *Decoder) {
3750   DecodeStatus S = MCDisassembler::Success;
3751 
3752   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3753   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3754   unsigned imm = fieldFromInstruction(Insn, 0, 4);
3755   imm |= fieldFromInstruction(Insn, 16, 3) << 4;
3756   imm |= fieldFromInstruction(Insn, 24, 1) << 7;
3757   imm |= fieldFromInstruction(Insn, 8, 4) << 8;
3758   imm |= fieldFromInstruction(Insn, 5, 1) << 12;
3759   unsigned Q = fieldFromInstruction(Insn, 6, 1);
3760 
3761   if (Q) {
3762     if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3763     return MCDisassembler::Fail;
3764   } else {
3765     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3766     return MCDisassembler::Fail;
3767   }
3768 
3769   Inst.addOperand(MCOperand::createImm(imm));
3770 
3771   switch (Inst.getOpcode()) {
3772     case ARM::VORRiv4i16:
3773     case ARM::VORRiv2i32:
3774     case ARM::VBICiv4i16:
3775     case ARM::VBICiv2i32:
3776       if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3777         return MCDisassembler::Fail;
3778       break;
3779     case ARM::VORRiv8i16:
3780     case ARM::VORRiv4i32:
3781     case ARM::VBICiv8i16:
3782     case ARM::VBICiv4i32:
3783       if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3784         return MCDisassembler::Fail;
3785       break;
3786     default:
3787       break;
3788   }
3789 
3790   return S;
3791 }
3792 
3793 static DecodeStatus DecodeMVEModImmInstruction(MCInst &Inst, unsigned Insn,
3794                                                uint64_t Address,
3795                                                const MCDisassembler *Decoder) {
3796   DecodeStatus S = MCDisassembler::Success;
3797 
3798   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
3799                  fieldFromInstruction(Insn, 13, 3));
3800   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
3801   unsigned imm = fieldFromInstruction(Insn, 0, 4);
3802   imm |= fieldFromInstruction(Insn, 16, 3) << 4;
3803   imm |= fieldFromInstruction(Insn, 28, 1) << 7;
3804   imm |= cmode                             << 8;
3805   imm |= fieldFromInstruction(Insn, 5, 1)  << 12;
3806 
3807   if (cmode == 0xF && Inst.getOpcode() == ARM::MVE_VMVNimmi32)
3808     return MCDisassembler::Fail;
3809 
3810   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
3811     return MCDisassembler::Fail;
3812 
3813   Inst.addOperand(MCOperand::createImm(imm));
3814 
3815   Inst.addOperand(MCOperand::createImm(ARMVCC::None));
3816   Inst.addOperand(MCOperand::createReg(0));
3817   Inst.addOperand(MCOperand::createImm(0));
3818 
3819   return S;
3820 }
3821 
3822 static DecodeStatus DecodeMVEVADCInstruction(MCInst &Inst, unsigned Insn,
3823                                              uint64_t Address,
3824                                              const MCDisassembler *Decoder) {
3825   DecodeStatus S = MCDisassembler::Success;
3826 
3827   unsigned Qd = fieldFromInstruction(Insn, 13, 3);
3828   Qd |= fieldFromInstruction(Insn, 22, 1) << 3;
3829   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
3830     return MCDisassembler::Fail;
3831   Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
3832 
3833   unsigned Qn = fieldFromInstruction(Insn, 17, 3);
3834   Qn |= fieldFromInstruction(Insn, 7, 1) << 3;
3835   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qn, Address, Decoder)))
3836     return MCDisassembler::Fail;
3837   unsigned Qm = fieldFromInstruction(Insn, 1, 3);
3838   Qm |= fieldFromInstruction(Insn, 5, 1) << 3;
3839   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
3840     return MCDisassembler::Fail;
3841   if (!fieldFromInstruction(Insn, 12, 1)) // I bit clear => need input FPSCR
3842     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
3843   Inst.addOperand(MCOperand::createImm(Qd));
3844 
3845   return S;
3846 }
3847 
3848 static DecodeStatus DecodeVSHLMaxInstruction(MCInst &Inst, unsigned Insn,
3849                                              uint64_t Address,
3850                                              const MCDisassembler *Decoder) {
3851   DecodeStatus S = MCDisassembler::Success;
3852 
3853   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3854   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3855   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3856   Rm |= fieldFromInstruction(Insn, 5, 1) << 4;
3857   unsigned size = fieldFromInstruction(Insn, 18, 2);
3858 
3859   if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3860     return MCDisassembler::Fail;
3861   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
3862     return MCDisassembler::Fail;
3863   Inst.addOperand(MCOperand::createImm(8 << size));
3864 
3865   return S;
3866 }
3867 
3868 static DecodeStatus DecodeShiftRight8Imm(MCInst &Inst, unsigned Val,
3869                                          uint64_t Address,
3870                                          const MCDisassembler *Decoder) {
3871   Inst.addOperand(MCOperand::createImm(8 - Val));
3872   return MCDisassembler::Success;
3873 }
3874 
3875 static DecodeStatus DecodeShiftRight16Imm(MCInst &Inst, unsigned Val,
3876                                           uint64_t Address,
3877                                           const MCDisassembler *Decoder) {
3878   Inst.addOperand(MCOperand::createImm(16 - Val));
3879   return MCDisassembler::Success;
3880 }
3881 
3882 static DecodeStatus DecodeShiftRight32Imm(MCInst &Inst, unsigned Val,
3883                                           uint64_t Address,
3884                                           const MCDisassembler *Decoder) {
3885   Inst.addOperand(MCOperand::createImm(32 - Val));
3886   return MCDisassembler::Success;
3887 }
3888 
3889 static DecodeStatus DecodeShiftRight64Imm(MCInst &Inst, unsigned Val,
3890                                           uint64_t Address,
3891                                           const MCDisassembler *Decoder) {
3892   Inst.addOperand(MCOperand::createImm(64 - Val));
3893   return MCDisassembler::Success;
3894 }
3895 
3896 static DecodeStatus DecodeTBLInstruction(MCInst &Inst, unsigned Insn,
3897                                          uint64_t Address,
3898                                          const MCDisassembler *Decoder) {
3899   DecodeStatus S = MCDisassembler::Success;
3900 
3901   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3902   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3903   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3904   Rn |= fieldFromInstruction(Insn, 7, 1) << 4;
3905   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3906   Rm |= fieldFromInstruction(Insn, 5, 1) << 4;
3907   unsigned op = fieldFromInstruction(Insn, 6, 1);
3908 
3909   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3910     return MCDisassembler::Fail;
3911   if (op) {
3912     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3913     return MCDisassembler::Fail; // Writeback
3914   }
3915 
3916   switch (Inst.getOpcode()) {
3917   case ARM::VTBL2:
3918   case ARM::VTBX2:
3919     if (!Check(S, DecodeDPairRegisterClass(Inst, Rn, Address, Decoder)))
3920       return MCDisassembler::Fail;
3921     break;
3922   default:
3923     if (!Check(S, DecodeDPRRegisterClass(Inst, Rn, Address, Decoder)))
3924       return MCDisassembler::Fail;
3925   }
3926 
3927   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
3928     return MCDisassembler::Fail;
3929 
3930   return S;
3931 }
3932 
3933 static DecodeStatus DecodeThumbAddSpecialReg(MCInst &Inst, uint16_t Insn,
3934                                              uint64_t Address,
3935                                              const MCDisassembler *Decoder) {
3936   DecodeStatus S = MCDisassembler::Success;
3937 
3938   unsigned dst = fieldFromInstruction(Insn, 8, 3);
3939   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3940 
3941   if (!Check(S, DecodetGPRRegisterClass(Inst, dst, Address, Decoder)))
3942     return MCDisassembler::Fail;
3943 
3944   switch(Inst.getOpcode()) {
3945     default:
3946       return MCDisassembler::Fail;
3947     case ARM::tADR:
3948       break; // tADR does not explicitly represent the PC as an operand.
3949     case ARM::tADDrSPi:
3950       Inst.addOperand(MCOperand::createReg(ARM::SP));
3951       break;
3952   }
3953 
3954   Inst.addOperand(MCOperand::createImm(imm));
3955   return S;
3956 }
3957 
3958 static DecodeStatus DecodeThumbBROperand(MCInst &Inst, unsigned Val,
3959                                          uint64_t Address,
3960                                          const MCDisassembler *Decoder) {
3961   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<12>(Val<<1) + 4,
3962                                 true, 2, Inst, Decoder))
3963     Inst.addOperand(MCOperand::createImm(SignExtend32<12>(Val << 1)));
3964   return MCDisassembler::Success;
3965 }
3966 
3967 static DecodeStatus DecodeT2BROperand(MCInst &Inst, unsigned Val,
3968                                       uint64_t Address,
3969                                       const MCDisassembler *Decoder) {
3970   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<21>(Val) + 4,
3971                                 true, 4, Inst, Decoder))
3972     Inst.addOperand(MCOperand::createImm(SignExtend32<21>(Val)));
3973   return MCDisassembler::Success;
3974 }
3975 
3976 static DecodeStatus DecodeThumbCmpBROperand(MCInst &Inst, unsigned Val,
3977                                             uint64_t Address,
3978                                             const MCDisassembler *Decoder) {
3979   if (!tryAddingSymbolicOperand(Address, Address + (Val<<1) + 4,
3980                                 true, 2, Inst, Decoder))
3981     Inst.addOperand(MCOperand::createImm(Val << 1));
3982   return MCDisassembler::Success;
3983 }
3984 
3985 static DecodeStatus DecodeThumbAddrModeRR(MCInst &Inst, unsigned Val,
3986                                           uint64_t Address,
3987                                           const MCDisassembler *Decoder) {
3988   DecodeStatus S = MCDisassembler::Success;
3989 
3990   unsigned Rn = fieldFromInstruction(Val, 0, 3);
3991   unsigned Rm = fieldFromInstruction(Val, 3, 3);
3992 
3993   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
3994     return MCDisassembler::Fail;
3995   if (!Check(S, DecodetGPRRegisterClass(Inst, Rm, Address, Decoder)))
3996     return MCDisassembler::Fail;
3997 
3998   return S;
3999 }
4000 
4001 static DecodeStatus DecodeThumbAddrModeIS(MCInst &Inst, unsigned Val,
4002                                           uint64_t Address,
4003                                           const MCDisassembler *Decoder) {
4004   DecodeStatus S = MCDisassembler::Success;
4005 
4006   unsigned Rn = fieldFromInstruction(Val, 0, 3);
4007   unsigned imm = fieldFromInstruction(Val, 3, 5);
4008 
4009   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
4010     return MCDisassembler::Fail;
4011   Inst.addOperand(MCOperand::createImm(imm));
4012 
4013   return S;
4014 }
4015 
4016 static DecodeStatus DecodeThumbAddrModePC(MCInst &Inst, unsigned Val,
4017                                           uint64_t Address,
4018                                           const MCDisassembler *Decoder) {
4019   unsigned imm = Val << 2;
4020 
4021   Inst.addOperand(MCOperand::createImm(imm));
4022   tryAddingPcLoadReferenceComment(Address, (Address & ~2u) + imm + 4, Decoder);
4023 
4024   return MCDisassembler::Success;
4025 }
4026 
4027 static DecodeStatus DecodeThumbAddrModeSP(MCInst &Inst, unsigned Val,
4028                                           uint64_t Address,
4029                                           const MCDisassembler *Decoder) {
4030   Inst.addOperand(MCOperand::createReg(ARM::SP));
4031   Inst.addOperand(MCOperand::createImm(Val));
4032 
4033   return MCDisassembler::Success;
4034 }
4035 
4036 static DecodeStatus DecodeT2AddrModeSOReg(MCInst &Inst, unsigned Val,
4037                                           uint64_t Address,
4038                                           const MCDisassembler *Decoder) {
4039   DecodeStatus S = MCDisassembler::Success;
4040 
4041   unsigned Rn = fieldFromInstruction(Val, 6, 4);
4042   unsigned Rm = fieldFromInstruction(Val, 2, 4);
4043   unsigned imm = fieldFromInstruction(Val, 0, 2);
4044 
4045   // Thumb stores cannot use PC as dest register.
4046   switch (Inst.getOpcode()) {
4047   case ARM::t2STRHs:
4048   case ARM::t2STRBs:
4049   case ARM::t2STRs:
4050     if (Rn == 15)
4051       return MCDisassembler::Fail;
4052     break;
4053   default:
4054     break;
4055   }
4056 
4057   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4058     return MCDisassembler::Fail;
4059   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
4060     return MCDisassembler::Fail;
4061   Inst.addOperand(MCOperand::createImm(imm));
4062 
4063   return S;
4064 }
4065 
4066 static DecodeStatus DecodeT2LoadShift(MCInst &Inst, unsigned Insn,
4067                                       uint64_t Address,
4068                                       const MCDisassembler *Decoder) {
4069   DecodeStatus S = MCDisassembler::Success;
4070 
4071   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4072   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4073 
4074   const FeatureBitset &featureBits =
4075     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4076 
4077   bool hasMP = featureBits[ARM::FeatureMP];
4078   bool hasV7Ops = featureBits[ARM::HasV7Ops];
4079 
4080   if (Rn == 15) {
4081     switch (Inst.getOpcode()) {
4082     case ARM::t2LDRBs:
4083       Inst.setOpcode(ARM::t2LDRBpci);
4084       break;
4085     case ARM::t2LDRHs:
4086       Inst.setOpcode(ARM::t2LDRHpci);
4087       break;
4088     case ARM::t2LDRSHs:
4089       Inst.setOpcode(ARM::t2LDRSHpci);
4090       break;
4091     case ARM::t2LDRSBs:
4092       Inst.setOpcode(ARM::t2LDRSBpci);
4093       break;
4094     case ARM::t2LDRs:
4095       Inst.setOpcode(ARM::t2LDRpci);
4096       break;
4097     case ARM::t2PLDs:
4098       Inst.setOpcode(ARM::t2PLDpci);
4099       break;
4100     case ARM::t2PLIs:
4101       Inst.setOpcode(ARM::t2PLIpci);
4102       break;
4103     default:
4104       return MCDisassembler::Fail;
4105     }
4106 
4107     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
4108   }
4109 
4110   if (Rt == 15) {
4111     switch (Inst.getOpcode()) {
4112     case ARM::t2LDRSHs:
4113       return MCDisassembler::Fail;
4114     case ARM::t2LDRHs:
4115       Inst.setOpcode(ARM::t2PLDWs);
4116       break;
4117     case ARM::t2LDRSBs:
4118       Inst.setOpcode(ARM::t2PLIs);
4119       break;
4120     default:
4121       break;
4122     }
4123   }
4124 
4125   switch (Inst.getOpcode()) {
4126     case ARM::t2PLDs:
4127       break;
4128     case ARM::t2PLIs:
4129       if (!hasV7Ops)
4130         return MCDisassembler::Fail;
4131       break;
4132     case ARM::t2PLDWs:
4133       if (!hasV7Ops || !hasMP)
4134         return MCDisassembler::Fail;
4135       break;
4136     default:
4137       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4138         return MCDisassembler::Fail;
4139   }
4140 
4141   unsigned addrmode = fieldFromInstruction(Insn, 4, 2);
4142   addrmode |= fieldFromInstruction(Insn, 0, 4) << 2;
4143   addrmode |= fieldFromInstruction(Insn, 16, 4) << 6;
4144   if (!Check(S, DecodeT2AddrModeSOReg(Inst, addrmode, Address, Decoder)))
4145     return MCDisassembler::Fail;
4146 
4147   return S;
4148 }
4149 
4150 static DecodeStatus DecodeT2LoadImm8(MCInst &Inst, unsigned Insn,
4151                                      uint64_t Address,
4152                                      const MCDisassembler *Decoder) {
4153   DecodeStatus S = MCDisassembler::Success;
4154 
4155   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4156   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4157   unsigned U = fieldFromInstruction(Insn, 9, 1);
4158   unsigned imm = fieldFromInstruction(Insn, 0, 8);
4159   imm |= (U << 8);
4160   imm |= (Rn << 9);
4161   unsigned add = fieldFromInstruction(Insn, 9, 1);
4162 
4163   const FeatureBitset &featureBits =
4164     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4165 
4166   bool hasMP = featureBits[ARM::FeatureMP];
4167   bool hasV7Ops = featureBits[ARM::HasV7Ops];
4168 
4169   if (Rn == 15) {
4170     switch (Inst.getOpcode()) {
4171     case ARM::t2LDRi8:
4172       Inst.setOpcode(ARM::t2LDRpci);
4173       break;
4174     case ARM::t2LDRBi8:
4175       Inst.setOpcode(ARM::t2LDRBpci);
4176       break;
4177     case ARM::t2LDRSBi8:
4178       Inst.setOpcode(ARM::t2LDRSBpci);
4179       break;
4180     case ARM::t2LDRHi8:
4181       Inst.setOpcode(ARM::t2LDRHpci);
4182       break;
4183     case ARM::t2LDRSHi8:
4184       Inst.setOpcode(ARM::t2LDRSHpci);
4185       break;
4186     case ARM::t2PLDi8:
4187       Inst.setOpcode(ARM::t2PLDpci);
4188       break;
4189     case ARM::t2PLIi8:
4190       Inst.setOpcode(ARM::t2PLIpci);
4191       break;
4192     default:
4193       return MCDisassembler::Fail;
4194     }
4195     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
4196   }
4197 
4198   if (Rt == 15) {
4199     switch (Inst.getOpcode()) {
4200     case ARM::t2LDRSHi8:
4201       return MCDisassembler::Fail;
4202     case ARM::t2LDRHi8:
4203       if (!add)
4204         Inst.setOpcode(ARM::t2PLDWi8);
4205       break;
4206     case ARM::t2LDRSBi8:
4207       Inst.setOpcode(ARM::t2PLIi8);
4208       break;
4209     default:
4210       break;
4211     }
4212   }
4213 
4214   switch (Inst.getOpcode()) {
4215   case ARM::t2PLDi8:
4216     break;
4217   case ARM::t2PLIi8:
4218     if (!hasV7Ops)
4219       return MCDisassembler::Fail;
4220     break;
4221   case ARM::t2PLDWi8:
4222       if (!hasV7Ops || !hasMP)
4223         return MCDisassembler::Fail;
4224       break;
4225   default:
4226     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4227       return MCDisassembler::Fail;
4228   }
4229 
4230   if (!Check(S, DecodeT2AddrModeImm8(Inst, imm, Address, Decoder)))
4231     return MCDisassembler::Fail;
4232   return S;
4233 }
4234 
4235 static DecodeStatus DecodeT2LoadImm12(MCInst &Inst, unsigned Insn,
4236                                       uint64_t Address,
4237                                       const MCDisassembler *Decoder) {
4238   DecodeStatus S = MCDisassembler::Success;
4239 
4240   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4241   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4242   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4243   imm |= (Rn << 13);
4244 
4245   const FeatureBitset &featureBits =
4246     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4247 
4248   bool hasMP = featureBits[ARM::FeatureMP];
4249   bool hasV7Ops = featureBits[ARM::HasV7Ops];
4250 
4251   if (Rn == 15) {
4252     switch (Inst.getOpcode()) {
4253     case ARM::t2LDRi12:
4254       Inst.setOpcode(ARM::t2LDRpci);
4255       break;
4256     case ARM::t2LDRHi12:
4257       Inst.setOpcode(ARM::t2LDRHpci);
4258       break;
4259     case ARM::t2LDRSHi12:
4260       Inst.setOpcode(ARM::t2LDRSHpci);
4261       break;
4262     case ARM::t2LDRBi12:
4263       Inst.setOpcode(ARM::t2LDRBpci);
4264       break;
4265     case ARM::t2LDRSBi12:
4266       Inst.setOpcode(ARM::t2LDRSBpci);
4267       break;
4268     case ARM::t2PLDi12:
4269       Inst.setOpcode(ARM::t2PLDpci);
4270       break;
4271     case ARM::t2PLIi12:
4272       Inst.setOpcode(ARM::t2PLIpci);
4273       break;
4274     default:
4275       return MCDisassembler::Fail;
4276     }
4277     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
4278   }
4279 
4280   if (Rt == 15) {
4281     switch (Inst.getOpcode()) {
4282     case ARM::t2LDRSHi12:
4283       return MCDisassembler::Fail;
4284     case ARM::t2LDRHi12:
4285       Inst.setOpcode(ARM::t2PLDWi12);
4286       break;
4287     case ARM::t2LDRSBi12:
4288       Inst.setOpcode(ARM::t2PLIi12);
4289       break;
4290     default:
4291       break;
4292     }
4293   }
4294 
4295   switch (Inst.getOpcode()) {
4296   case ARM::t2PLDi12:
4297     break;
4298   case ARM::t2PLIi12:
4299     if (!hasV7Ops)
4300       return MCDisassembler::Fail;
4301     break;
4302   case ARM::t2PLDWi12:
4303       if (!hasV7Ops || !hasMP)
4304         return MCDisassembler::Fail;
4305       break;
4306   default:
4307     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4308       return MCDisassembler::Fail;
4309   }
4310 
4311   if (!Check(S, DecodeT2AddrModeImm12(Inst, imm, Address, Decoder)))
4312     return MCDisassembler::Fail;
4313   return S;
4314 }
4315 
4316 static DecodeStatus DecodeT2LoadT(MCInst &Inst, unsigned Insn, uint64_t Address,
4317                                   const MCDisassembler *Decoder) {
4318   DecodeStatus S = MCDisassembler::Success;
4319 
4320   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4321   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4322   unsigned imm = fieldFromInstruction(Insn, 0, 8);
4323   imm |= (Rn << 9);
4324 
4325   if (Rn == 15) {
4326     switch (Inst.getOpcode()) {
4327     case ARM::t2LDRT:
4328       Inst.setOpcode(ARM::t2LDRpci);
4329       break;
4330     case ARM::t2LDRBT:
4331       Inst.setOpcode(ARM::t2LDRBpci);
4332       break;
4333     case ARM::t2LDRHT:
4334       Inst.setOpcode(ARM::t2LDRHpci);
4335       break;
4336     case ARM::t2LDRSBT:
4337       Inst.setOpcode(ARM::t2LDRSBpci);
4338       break;
4339     case ARM::t2LDRSHT:
4340       Inst.setOpcode(ARM::t2LDRSHpci);
4341       break;
4342     default:
4343       return MCDisassembler::Fail;
4344     }
4345     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
4346   }
4347 
4348   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
4349     return MCDisassembler::Fail;
4350   if (!Check(S, DecodeT2AddrModeImm8(Inst, imm, Address, Decoder)))
4351     return MCDisassembler::Fail;
4352   return S;
4353 }
4354 
4355 static DecodeStatus DecodeT2LoadLabel(MCInst &Inst, unsigned Insn,
4356                                       uint64_t Address,
4357                                       const MCDisassembler *Decoder) {
4358   DecodeStatus S = MCDisassembler::Success;
4359 
4360   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4361   unsigned U = fieldFromInstruction(Insn, 23, 1);
4362   int imm = fieldFromInstruction(Insn, 0, 12);
4363 
4364   const FeatureBitset &featureBits =
4365     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4366 
4367   bool hasV7Ops = featureBits[ARM::HasV7Ops];
4368 
4369   if (Rt == 15) {
4370     switch (Inst.getOpcode()) {
4371       case ARM::t2LDRBpci:
4372       case ARM::t2LDRHpci:
4373         Inst.setOpcode(ARM::t2PLDpci);
4374         break;
4375       case ARM::t2LDRSBpci:
4376         Inst.setOpcode(ARM::t2PLIpci);
4377         break;
4378       case ARM::t2LDRSHpci:
4379         return MCDisassembler::Fail;
4380       default:
4381         break;
4382     }
4383   }
4384 
4385   switch(Inst.getOpcode()) {
4386   case ARM::t2PLDpci:
4387     break;
4388   case ARM::t2PLIpci:
4389     if (!hasV7Ops)
4390       return MCDisassembler::Fail;
4391     break;
4392   default:
4393     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4394       return MCDisassembler::Fail;
4395   }
4396 
4397   if (!U) {
4398     // Special case for #-0.
4399     if (imm == 0)
4400       imm = INT32_MIN;
4401     else
4402       imm = -imm;
4403   }
4404   Inst.addOperand(MCOperand::createImm(imm));
4405 
4406   return S;
4407 }
4408 
4409 static DecodeStatus DecodeT2Imm8S4(MCInst &Inst, unsigned Val, uint64_t Address,
4410                                    const MCDisassembler *Decoder) {
4411   if (Val == 0)
4412     Inst.addOperand(MCOperand::createImm(INT32_MIN));
4413   else {
4414     int imm = Val & 0xFF;
4415 
4416     if (!(Val & 0x100)) imm *= -1;
4417     Inst.addOperand(MCOperand::createImm(imm * 4));
4418   }
4419 
4420   return MCDisassembler::Success;
4421 }
4422 
4423 static DecodeStatus DecodeT2Imm7S4(MCInst &Inst, unsigned Val, uint64_t Address,
4424                                    const MCDisassembler *Decoder) {
4425   if (Val == 0)
4426     Inst.addOperand(MCOperand::createImm(INT32_MIN));
4427   else {
4428     int imm = Val & 0x7F;
4429 
4430     if (!(Val & 0x80))
4431       imm *= -1;
4432     Inst.addOperand(MCOperand::createImm(imm * 4));
4433   }
4434 
4435   return MCDisassembler::Success;
4436 }
4437 
4438 static DecodeStatus DecodeT2AddrModeImm8s4(MCInst &Inst, unsigned Val,
4439                                            uint64_t Address,
4440                                            const MCDisassembler *Decoder) {
4441   DecodeStatus S = MCDisassembler::Success;
4442 
4443   unsigned Rn = fieldFromInstruction(Val, 9, 4);
4444   unsigned imm = fieldFromInstruction(Val, 0, 9);
4445 
4446   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4447     return MCDisassembler::Fail;
4448   if (!Check(S, DecodeT2Imm8S4(Inst, imm, Address, Decoder)))
4449     return MCDisassembler::Fail;
4450 
4451   return S;
4452 }
4453 
4454 static DecodeStatus DecodeT2AddrModeImm7s4(MCInst &Inst, unsigned Val,
4455                                            uint64_t Address,
4456                                            const MCDisassembler *Decoder) {
4457   DecodeStatus S = MCDisassembler::Success;
4458 
4459   unsigned Rn = fieldFromInstruction(Val, 8, 4);
4460   unsigned imm = fieldFromInstruction(Val, 0, 8);
4461 
4462   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4463     return MCDisassembler::Fail;
4464   if (!Check(S, DecodeT2Imm7S4(Inst, imm, Address, Decoder)))
4465     return MCDisassembler::Fail;
4466 
4467   return S;
4468 }
4469 
4470 static DecodeStatus DecodeT2AddrModeImm0_1020s4(MCInst &Inst, unsigned Val,
4471                                                 uint64_t Address,
4472                                                 const MCDisassembler *Decoder) {
4473   DecodeStatus S = MCDisassembler::Success;
4474 
4475   unsigned Rn = fieldFromInstruction(Val, 8, 4);
4476   unsigned imm = fieldFromInstruction(Val, 0, 8);
4477 
4478   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4479     return MCDisassembler::Fail;
4480 
4481   Inst.addOperand(MCOperand::createImm(imm));
4482 
4483   return S;
4484 }
4485 
4486 static DecodeStatus DecodeT2Imm8(MCInst &Inst, unsigned Val, uint64_t Address,
4487                                  const MCDisassembler *Decoder) {
4488   int imm = Val & 0xFF;
4489   if (Val == 0)
4490     imm = INT32_MIN;
4491   else if (!(Val & 0x100))
4492     imm *= -1;
4493   Inst.addOperand(MCOperand::createImm(imm));
4494 
4495   return MCDisassembler::Success;
4496 }
4497 
4498 template <int shift>
4499 static DecodeStatus DecodeT2Imm7(MCInst &Inst, unsigned Val, uint64_t Address,
4500                                  const MCDisassembler *Decoder) {
4501   int imm = Val & 0x7F;
4502   if (Val == 0)
4503     imm = INT32_MIN;
4504   else if (!(Val & 0x80))
4505     imm *= -1;
4506   if (imm != INT32_MIN)
4507     imm *= (1U << shift);
4508   Inst.addOperand(MCOperand::createImm(imm));
4509 
4510   return MCDisassembler::Success;
4511 }
4512 
4513 static DecodeStatus DecodeT2AddrModeImm8(MCInst &Inst, unsigned Val,
4514                                          uint64_t Address,
4515                                          const MCDisassembler *Decoder) {
4516   DecodeStatus S = MCDisassembler::Success;
4517 
4518   unsigned Rn = fieldFromInstruction(Val, 9, 4);
4519   unsigned imm = fieldFromInstruction(Val, 0, 9);
4520 
4521   // Thumb stores cannot use PC as dest register.
4522   switch (Inst.getOpcode()) {
4523   case ARM::t2STRT:
4524   case ARM::t2STRBT:
4525   case ARM::t2STRHT:
4526   case ARM::t2STRi8:
4527   case ARM::t2STRHi8:
4528   case ARM::t2STRBi8:
4529     if (Rn == 15)
4530       return MCDisassembler::Fail;
4531     break;
4532   default:
4533     break;
4534   }
4535 
4536   // Some instructions always use an additive offset.
4537   switch (Inst.getOpcode()) {
4538     case ARM::t2LDRT:
4539     case ARM::t2LDRBT:
4540     case ARM::t2LDRHT:
4541     case ARM::t2LDRSBT:
4542     case ARM::t2LDRSHT:
4543     case ARM::t2STRT:
4544     case ARM::t2STRBT:
4545     case ARM::t2STRHT:
4546       imm |= 0x100;
4547       break;
4548     default:
4549       break;
4550   }
4551 
4552   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4553     return MCDisassembler::Fail;
4554   if (!Check(S, DecodeT2Imm8(Inst, imm, Address, Decoder)))
4555     return MCDisassembler::Fail;
4556 
4557   return S;
4558 }
4559 
4560 template <int shift>
4561 static DecodeStatus DecodeTAddrModeImm7(MCInst &Inst, unsigned Val,
4562                                         uint64_t Address,
4563                                         const MCDisassembler *Decoder) {
4564   DecodeStatus S = MCDisassembler::Success;
4565 
4566   unsigned Rn = fieldFromInstruction(Val, 8, 3);
4567   unsigned imm = fieldFromInstruction(Val, 0, 8);
4568 
4569   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
4570     return MCDisassembler::Fail;
4571   if (!Check(S, DecodeT2Imm7<shift>(Inst, imm, Address, Decoder)))
4572     return MCDisassembler::Fail;
4573 
4574   return S;
4575 }
4576 
4577 template <int shift, int WriteBack>
4578 static DecodeStatus DecodeT2AddrModeImm7(MCInst &Inst, unsigned Val,
4579                                          uint64_t Address,
4580                                          const MCDisassembler *Decoder) {
4581   DecodeStatus S = MCDisassembler::Success;
4582 
4583   unsigned Rn = fieldFromInstruction(Val, 8, 4);
4584   unsigned imm = fieldFromInstruction(Val, 0, 8);
4585   if (WriteBack) {
4586     if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
4587       return MCDisassembler::Fail;
4588   } else if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4589     return MCDisassembler::Fail;
4590   if (!Check(S, DecodeT2Imm7<shift>(Inst, imm, Address, Decoder)))
4591     return MCDisassembler::Fail;
4592 
4593   return S;
4594 }
4595 
4596 static DecodeStatus DecodeT2LdStPre(MCInst &Inst, unsigned Insn,
4597                                     uint64_t Address,
4598                                     const MCDisassembler *Decoder) {
4599   DecodeStatus S = MCDisassembler::Success;
4600 
4601   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4602   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4603   unsigned addr = fieldFromInstruction(Insn, 0, 8);
4604   addr |= fieldFromInstruction(Insn, 9, 1) << 8;
4605   addr |= Rn << 9;
4606   unsigned load = fieldFromInstruction(Insn, 20, 1);
4607 
4608   if (Rn == 15) {
4609     switch (Inst.getOpcode()) {
4610     case ARM::t2LDR_PRE:
4611     case ARM::t2LDR_POST:
4612       Inst.setOpcode(ARM::t2LDRpci);
4613       break;
4614     case ARM::t2LDRB_PRE:
4615     case ARM::t2LDRB_POST:
4616       Inst.setOpcode(ARM::t2LDRBpci);
4617       break;
4618     case ARM::t2LDRH_PRE:
4619     case ARM::t2LDRH_POST:
4620       Inst.setOpcode(ARM::t2LDRHpci);
4621       break;
4622     case ARM::t2LDRSB_PRE:
4623     case ARM::t2LDRSB_POST:
4624       if (Rt == 15)
4625         Inst.setOpcode(ARM::t2PLIpci);
4626       else
4627         Inst.setOpcode(ARM::t2LDRSBpci);
4628       break;
4629     case ARM::t2LDRSH_PRE:
4630     case ARM::t2LDRSH_POST:
4631       Inst.setOpcode(ARM::t2LDRSHpci);
4632       break;
4633     default:
4634       return MCDisassembler::Fail;
4635     }
4636     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
4637   }
4638 
4639   if (!load) {
4640     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4641       return MCDisassembler::Fail;
4642   }
4643 
4644   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4645     return MCDisassembler::Fail;
4646 
4647   if (load) {
4648     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4649       return MCDisassembler::Fail;
4650   }
4651 
4652   if (!Check(S, DecodeT2AddrModeImm8(Inst, addr, Address, Decoder)))
4653     return MCDisassembler::Fail;
4654 
4655   return S;
4656 }
4657 
4658 static DecodeStatus DecodeT2AddrModeImm12(MCInst &Inst, unsigned Val,
4659                                           uint64_t Address,
4660                                           const MCDisassembler *Decoder) {
4661   DecodeStatus S = MCDisassembler::Success;
4662 
4663   unsigned Rn = fieldFromInstruction(Val, 13, 4);
4664   unsigned imm = fieldFromInstruction(Val, 0, 12);
4665 
4666   // Thumb stores cannot use PC as dest register.
4667   switch (Inst.getOpcode()) {
4668   case ARM::t2STRi12:
4669   case ARM::t2STRBi12:
4670   case ARM::t2STRHi12:
4671     if (Rn == 15)
4672       return MCDisassembler::Fail;
4673     break;
4674   default:
4675     break;
4676   }
4677 
4678   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4679     return MCDisassembler::Fail;
4680   Inst.addOperand(MCOperand::createImm(imm));
4681 
4682   return S;
4683 }
4684 
4685 static DecodeStatus DecodeThumbAddSPImm(MCInst &Inst, uint16_t Insn,
4686                                         uint64_t Address,
4687                                         const MCDisassembler *Decoder) {
4688   unsigned imm = fieldFromInstruction(Insn, 0, 7);
4689 
4690   Inst.addOperand(MCOperand::createReg(ARM::SP));
4691   Inst.addOperand(MCOperand::createReg(ARM::SP));
4692   Inst.addOperand(MCOperand::createImm(imm));
4693 
4694   return MCDisassembler::Success;
4695 }
4696 
4697 static DecodeStatus DecodeThumbAddSPReg(MCInst &Inst, uint16_t Insn,
4698                                         uint64_t Address,
4699                                         const MCDisassembler *Decoder) {
4700   DecodeStatus S = MCDisassembler::Success;
4701 
4702   if (Inst.getOpcode() == ARM::tADDrSP) {
4703     unsigned Rdm = fieldFromInstruction(Insn, 0, 3);
4704     Rdm |= fieldFromInstruction(Insn, 7, 1) << 3;
4705 
4706     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
4707     return MCDisassembler::Fail;
4708     Inst.addOperand(MCOperand::createReg(ARM::SP));
4709     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
4710     return MCDisassembler::Fail;
4711   } else if (Inst.getOpcode() == ARM::tADDspr) {
4712     unsigned Rm = fieldFromInstruction(Insn, 3, 4);
4713 
4714     Inst.addOperand(MCOperand::createReg(ARM::SP));
4715     Inst.addOperand(MCOperand::createReg(ARM::SP));
4716     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4717     return MCDisassembler::Fail;
4718   }
4719 
4720   return S;
4721 }
4722 
4723 static DecodeStatus DecodeThumbCPS(MCInst &Inst, uint16_t Insn,
4724                                    uint64_t Address,
4725                                    const MCDisassembler *Decoder) {
4726   unsigned imod = fieldFromInstruction(Insn, 4, 1) | 0x2;
4727   unsigned flags = fieldFromInstruction(Insn, 0, 3);
4728 
4729   Inst.addOperand(MCOperand::createImm(imod));
4730   Inst.addOperand(MCOperand::createImm(flags));
4731 
4732   return MCDisassembler::Success;
4733 }
4734 
4735 static DecodeStatus DecodePostIdxReg(MCInst &Inst, unsigned Insn,
4736                                      uint64_t Address,
4737                                      const MCDisassembler *Decoder) {
4738   DecodeStatus S = MCDisassembler::Success;
4739   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4740   unsigned add = fieldFromInstruction(Insn, 4, 1);
4741 
4742   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
4743     return MCDisassembler::Fail;
4744   Inst.addOperand(MCOperand::createImm(add));
4745 
4746   return S;
4747 }
4748 
4749 static DecodeStatus DecodeMveAddrModeRQ(MCInst &Inst, unsigned Insn,
4750                                         uint64_t Address,
4751                                         const MCDisassembler *Decoder) {
4752   DecodeStatus S = MCDisassembler::Success;
4753   unsigned Rn = fieldFromInstruction(Insn, 3, 4);
4754   unsigned Qm = fieldFromInstruction(Insn, 0, 3);
4755 
4756   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4757     return MCDisassembler::Fail;
4758   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
4759     return MCDisassembler::Fail;
4760 
4761   return S;
4762 }
4763 
4764 template <int shift>
4765 static DecodeStatus DecodeMveAddrModeQ(MCInst &Inst, unsigned Insn,
4766                                        uint64_t Address,
4767                                        const MCDisassembler *Decoder) {
4768   DecodeStatus S = MCDisassembler::Success;
4769   unsigned Qm = fieldFromInstruction(Insn, 8, 3);
4770   int imm = fieldFromInstruction(Insn, 0, 7);
4771 
4772   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
4773     return MCDisassembler::Fail;
4774 
4775   if(!fieldFromInstruction(Insn, 7, 1)) {
4776     if (imm == 0)
4777       imm = INT32_MIN;                 // indicate -0
4778     else
4779       imm *= -1;
4780   }
4781   if (imm != INT32_MIN)
4782     imm *= (1U << shift);
4783   Inst.addOperand(MCOperand::createImm(imm));
4784 
4785   return S;
4786 }
4787 
4788 static DecodeStatus DecodeThumbBLXOffset(MCInst &Inst, unsigned Val,
4789                                          uint64_t Address,
4790                                          const MCDisassembler *Decoder) {
4791   // Val is passed in as S:J1:J2:imm10H:imm10L:'0'
4792   // Note only one trailing zero not two.  Also the J1 and J2 values are from
4793   // the encoded instruction.  So here change to I1 and I2 values via:
4794   // I1 = NOT(J1 EOR S);
4795   // I2 = NOT(J2 EOR S);
4796   // and build the imm32 with two trailing zeros as documented:
4797   // imm32 = SignExtend(S:I1:I2:imm10H:imm10L:'00', 32);
4798   unsigned S = (Val >> 23) & 1;
4799   unsigned J1 = (Val >> 22) & 1;
4800   unsigned J2 = (Val >> 21) & 1;
4801   unsigned I1 = !(J1 ^ S);
4802   unsigned I2 = !(J2 ^ S);
4803   unsigned tmp = (Val & ~0x600000) | (I1 << 22) | (I2 << 21);
4804   int imm32 = SignExtend32<25>(tmp << 1);
4805 
4806   if (!tryAddingSymbolicOperand(Address,
4807                                 (Address & ~2u) + imm32 + 4,
4808                                 true, 4, Inst, Decoder))
4809     Inst.addOperand(MCOperand::createImm(imm32));
4810   return MCDisassembler::Success;
4811 }
4812 
4813 static DecodeStatus DecodeCoprocessor(MCInst &Inst, unsigned Val,
4814                                       uint64_t Address,
4815                                       const MCDisassembler *Decoder) {
4816   if (Val == 0xA || Val == 0xB)
4817     return MCDisassembler::Fail;
4818 
4819   const FeatureBitset &featureBits =
4820     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4821 
4822   if (!isValidCoprocessorNumber(Val, featureBits))
4823     return MCDisassembler::Fail;
4824 
4825   Inst.addOperand(MCOperand::createImm(Val));
4826   return MCDisassembler::Success;
4827 }
4828 
4829 static DecodeStatus DecodeThumbTableBranch(MCInst &Inst, unsigned Insn,
4830                                            uint64_t Address,
4831                                            const MCDisassembler *Decoder) {
4832   const FeatureBitset &FeatureBits =
4833     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4834   DecodeStatus S = MCDisassembler::Success;
4835 
4836   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4837   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4838 
4839   if (Rn == 13 && !FeatureBits[ARM::HasV8Ops]) S = MCDisassembler::SoftFail;
4840   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4841     return MCDisassembler::Fail;
4842   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
4843     return MCDisassembler::Fail;
4844   return S;
4845 }
4846 
4847 static DecodeStatus DecodeThumb2BCCInstruction(MCInst &Inst, unsigned Insn,
4848                                                uint64_t Address,
4849                                                const MCDisassembler *Decoder) {
4850   DecodeStatus S = MCDisassembler::Success;
4851 
4852   unsigned pred = fieldFromInstruction(Insn, 22, 4);
4853   if (pred == 0xE || pred == 0xF) {
4854     unsigned opc = fieldFromInstruction(Insn, 4, 28);
4855     switch (opc) {
4856       default:
4857         return MCDisassembler::Fail;
4858       case 0xf3bf8f4:
4859         Inst.setOpcode(ARM::t2DSB);
4860         break;
4861       case 0xf3bf8f5:
4862         Inst.setOpcode(ARM::t2DMB);
4863         break;
4864       case 0xf3bf8f6:
4865         Inst.setOpcode(ARM::t2ISB);
4866         break;
4867     }
4868 
4869     unsigned imm = fieldFromInstruction(Insn, 0, 4);
4870     return DecodeMemBarrierOption(Inst, imm, Address, Decoder);
4871   }
4872 
4873   unsigned brtarget = fieldFromInstruction(Insn, 0, 11) << 1;
4874   brtarget |= fieldFromInstruction(Insn, 11, 1) << 19;
4875   brtarget |= fieldFromInstruction(Insn, 13, 1) << 18;
4876   brtarget |= fieldFromInstruction(Insn, 16, 6) << 12;
4877   brtarget |= fieldFromInstruction(Insn, 26, 1) << 20;
4878 
4879   if (!Check(S, DecodeT2BROperand(Inst, brtarget, Address, Decoder)))
4880     return MCDisassembler::Fail;
4881   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4882     return MCDisassembler::Fail;
4883 
4884   return S;
4885 }
4886 
4887 // Decode a shifted immediate operand.  These basically consist
4888 // of an 8-bit value, and a 4-bit directive that specifies either
4889 // a splat operation or a rotation.
4890 static DecodeStatus DecodeT2SOImm(MCInst &Inst, unsigned Val, uint64_t Address,
4891                                   const MCDisassembler *Decoder) {
4892   unsigned ctrl = fieldFromInstruction(Val, 10, 2);
4893   if (ctrl == 0) {
4894     unsigned byte = fieldFromInstruction(Val, 8, 2);
4895     unsigned imm = fieldFromInstruction(Val, 0, 8);
4896     switch (byte) {
4897       case 0:
4898         Inst.addOperand(MCOperand::createImm(imm));
4899         break;
4900       case 1:
4901         Inst.addOperand(MCOperand::createImm((imm << 16) | imm));
4902         break;
4903       case 2:
4904         Inst.addOperand(MCOperand::createImm((imm << 24) | (imm << 8)));
4905         break;
4906       case 3:
4907         Inst.addOperand(MCOperand::createImm((imm << 24) | (imm << 16) |
4908                                              (imm << 8)  |  imm));
4909         break;
4910     }
4911   } else {
4912     unsigned unrot = fieldFromInstruction(Val, 0, 7) | 0x80;
4913     unsigned rot = fieldFromInstruction(Val, 7, 5);
4914     unsigned imm = (unrot >> rot) | (unrot << ((32-rot)&31));
4915     Inst.addOperand(MCOperand::createImm(imm));
4916   }
4917 
4918   return MCDisassembler::Success;
4919 }
4920 
4921 static DecodeStatus DecodeThumbBCCTargetOperand(MCInst &Inst, unsigned Val,
4922                                                 uint64_t Address,
4923                                                 const MCDisassembler *Decoder) {
4924   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<9>(Val<<1) + 4,
4925                                 true, 2, Inst, Decoder))
4926     Inst.addOperand(MCOperand::createImm(SignExtend32<9>(Val << 1)));
4927   return MCDisassembler::Success;
4928 }
4929 
4930 static DecodeStatus DecodeThumbBLTargetOperand(MCInst &Inst, unsigned Val,
4931                                                uint64_t Address,
4932                                                const MCDisassembler *Decoder) {
4933   // Val is passed in as S:J1:J2:imm10:imm11
4934   // Note no trailing zero after imm11.  Also the J1 and J2 values are from
4935   // the encoded instruction.  So here change to I1 and I2 values via:
4936   // I1 = NOT(J1 EOR S);
4937   // I2 = NOT(J2 EOR S);
4938   // and build the imm32 with one trailing zero as documented:
4939   // imm32 = SignExtend(S:I1:I2:imm10:imm11:'0', 32);
4940   unsigned S = (Val >> 23) & 1;
4941   unsigned J1 = (Val >> 22) & 1;
4942   unsigned J2 = (Val >> 21) & 1;
4943   unsigned I1 = !(J1 ^ S);
4944   unsigned I2 = !(J2 ^ S);
4945   unsigned tmp = (Val & ~0x600000) | (I1 << 22) | (I2 << 21);
4946   int imm32 = SignExtend32<25>(tmp << 1);
4947 
4948   if (!tryAddingSymbolicOperand(Address, Address + imm32 + 4,
4949                                 true, 4, Inst, Decoder))
4950     Inst.addOperand(MCOperand::createImm(imm32));
4951   return MCDisassembler::Success;
4952 }
4953 
4954 static DecodeStatus DecodeMemBarrierOption(MCInst &Inst, unsigned Val,
4955                                            uint64_t Address,
4956                                            const MCDisassembler *Decoder) {
4957   if (Val & ~0xf)
4958     return MCDisassembler::Fail;
4959 
4960   Inst.addOperand(MCOperand::createImm(Val));
4961   return MCDisassembler::Success;
4962 }
4963 
4964 static DecodeStatus DecodeInstSyncBarrierOption(MCInst &Inst, unsigned Val,
4965                                                 uint64_t Address,
4966                                                 const MCDisassembler *Decoder) {
4967   if (Val & ~0xf)
4968     return MCDisassembler::Fail;
4969 
4970   Inst.addOperand(MCOperand::createImm(Val));
4971   return MCDisassembler::Success;
4972 }
4973 
4974 static DecodeStatus DecodeMSRMask(MCInst &Inst, unsigned Val, uint64_t Address,
4975                                   const MCDisassembler *Decoder) {
4976   DecodeStatus S = MCDisassembler::Success;
4977   const FeatureBitset &FeatureBits =
4978     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4979 
4980   if (FeatureBits[ARM::FeatureMClass]) {
4981     unsigned ValLow = Val & 0xff;
4982 
4983     // Validate the SYSm value first.
4984     switch (ValLow) {
4985     case  0: // apsr
4986     case  1: // iapsr
4987     case  2: // eapsr
4988     case  3: // xpsr
4989     case  5: // ipsr
4990     case  6: // epsr
4991     case  7: // iepsr
4992     case  8: // msp
4993     case  9: // psp
4994     case 16: // primask
4995     case 20: // control
4996       break;
4997     case 17: // basepri
4998     case 18: // basepri_max
4999     case 19: // faultmask
5000       if (!(FeatureBits[ARM::HasV7Ops]))
5001         // Values basepri, basepri_max and faultmask are only valid for v7m.
5002         return MCDisassembler::Fail;
5003       break;
5004     case 0x8a: // msplim_ns
5005     case 0x8b: // psplim_ns
5006     case 0x91: // basepri_ns
5007     case 0x93: // faultmask_ns
5008       if (!(FeatureBits[ARM::HasV8MMainlineOps]))
5009         return MCDisassembler::Fail;
5010       LLVM_FALLTHROUGH;
5011     case 10:   // msplim
5012     case 11:   // psplim
5013     case 0x88: // msp_ns
5014     case 0x89: // psp_ns
5015     case 0x90: // primask_ns
5016     case 0x94: // control_ns
5017     case 0x98: // sp_ns
5018       if (!(FeatureBits[ARM::Feature8MSecExt]))
5019         return MCDisassembler::Fail;
5020       break;
5021     case 0x20: // pac_key_p_0
5022     case 0x21: // pac_key_p_1
5023     case 0x22: // pac_key_p_2
5024     case 0x23: // pac_key_p_3
5025     case 0x24: // pac_key_u_0
5026     case 0x25: // pac_key_u_1
5027     case 0x26: // pac_key_u_2
5028     case 0x27: // pac_key_u_3
5029     case 0xa0: // pac_key_p_0_ns
5030     case 0xa1: // pac_key_p_1_ns
5031     case 0xa2: // pac_key_p_2_ns
5032     case 0xa3: // pac_key_p_3_ns
5033     case 0xa4: // pac_key_u_0_ns
5034     case 0xa5: // pac_key_u_1_ns
5035     case 0xa6: // pac_key_u_2_ns
5036     case 0xa7: // pac_key_u_3_ns
5037       if (!(FeatureBits[ARM::FeaturePACBTI]))
5038         return MCDisassembler::Fail;
5039       break;
5040     default:
5041       // Architecturally defined as unpredictable
5042       S = MCDisassembler::SoftFail;
5043       break;
5044     }
5045 
5046     if (Inst.getOpcode() == ARM::t2MSR_M) {
5047       unsigned Mask = fieldFromInstruction(Val, 10, 2);
5048       if (!(FeatureBits[ARM::HasV7Ops])) {
5049         // The ARMv6-M MSR bits {11-10} can be only 0b10, other values are
5050         // unpredictable.
5051         if (Mask != 2)
5052           S = MCDisassembler::SoftFail;
5053       }
5054       else {
5055         // The ARMv7-M architecture stores an additional 2-bit mask value in
5056         // MSR bits {11-10}. The mask is used only with apsr, iapsr, eapsr and
5057         // xpsr, it has to be 0b10 in other cases. Bit mask{1} indicates if
5058         // the NZCVQ bits should be moved by the instruction. Bit mask{0}
5059         // indicates the move for the GE{3:0} bits, the mask{0} bit can be set
5060         // only if the processor includes the DSP extension.
5061         if (Mask == 0 || (Mask != 2 && ValLow > 3) ||
5062             (!(FeatureBits[ARM::FeatureDSP]) && (Mask & 1)))
5063           S = MCDisassembler::SoftFail;
5064       }
5065     }
5066   } else {
5067     // A/R class
5068     if (Val == 0)
5069       return MCDisassembler::Fail;
5070   }
5071   Inst.addOperand(MCOperand::createImm(Val));
5072   return S;
5073 }
5074 
5075 static DecodeStatus DecodeBankedReg(MCInst &Inst, unsigned Val,
5076                                     uint64_t Address,
5077                                     const MCDisassembler *Decoder) {
5078   unsigned R = fieldFromInstruction(Val, 5, 1);
5079   unsigned SysM = fieldFromInstruction(Val, 0, 5);
5080 
5081   // The table of encodings for these banked registers comes from B9.2.3 of the
5082   // ARM ARM. There are patterns, but nothing regular enough to make this logic
5083   // neater. So by fiat, these values are UNPREDICTABLE:
5084   if (!ARMBankedReg::lookupBankedRegByEncoding((R << 5) | SysM))
5085     return MCDisassembler::Fail;
5086 
5087   Inst.addOperand(MCOperand::createImm(Val));
5088   return MCDisassembler::Success;
5089 }
5090 
5091 static DecodeStatus DecodeDoubleRegLoad(MCInst &Inst, unsigned Insn,
5092                                         uint64_t Address,
5093                                         const MCDisassembler *Decoder) {
5094   DecodeStatus S = MCDisassembler::Success;
5095 
5096   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5097   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5098   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5099 
5100   if (Rn == 0xF)
5101     S = MCDisassembler::SoftFail;
5102 
5103   if (!Check(S, DecodeGPRPairRegisterClass(Inst, Rt, Address, Decoder)))
5104     return MCDisassembler::Fail;
5105   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5106     return MCDisassembler::Fail;
5107   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5108     return MCDisassembler::Fail;
5109 
5110   return S;
5111 }
5112 
5113 static DecodeStatus DecodeDoubleRegStore(MCInst &Inst, unsigned Insn,
5114                                          uint64_t Address,
5115                                          const MCDisassembler *Decoder) {
5116   DecodeStatus S = MCDisassembler::Success;
5117 
5118   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5119   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
5120   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5121   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5122 
5123   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
5124     return MCDisassembler::Fail;
5125 
5126   if (Rn == 0xF || Rd == Rn || Rd == Rt || Rd == Rt+1)
5127     S = MCDisassembler::SoftFail;
5128 
5129   if (!Check(S, DecodeGPRPairRegisterClass(Inst, Rt, Address, Decoder)))
5130     return MCDisassembler::Fail;
5131   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5132     return MCDisassembler::Fail;
5133   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5134     return MCDisassembler::Fail;
5135 
5136   return S;
5137 }
5138 
5139 static DecodeStatus DecodeLDRPreImm(MCInst &Inst, unsigned Insn,
5140                                     uint64_t Address,
5141                                     const MCDisassembler *Decoder) {
5142   DecodeStatus S = MCDisassembler::Success;
5143 
5144   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5145   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5146   unsigned imm = fieldFromInstruction(Insn, 0, 12);
5147   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
5148   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
5149   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5150 
5151   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
5152 
5153   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
5154     return MCDisassembler::Fail;
5155   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5156     return MCDisassembler::Fail;
5157   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
5158     return MCDisassembler::Fail;
5159   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5160     return MCDisassembler::Fail;
5161 
5162   return S;
5163 }
5164 
5165 static DecodeStatus DecodeLDRPreReg(MCInst &Inst, unsigned Insn,
5166                                     uint64_t Address,
5167                                     const MCDisassembler *Decoder) {
5168   DecodeStatus S = MCDisassembler::Success;
5169 
5170   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5171   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5172   unsigned imm = fieldFromInstruction(Insn, 0, 12);
5173   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
5174   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
5175   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5176   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5177 
5178   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
5179   if (Rm == 0xF) S = MCDisassembler::SoftFail;
5180 
5181   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
5182     return MCDisassembler::Fail;
5183   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5184     return MCDisassembler::Fail;
5185   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
5186     return MCDisassembler::Fail;
5187   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5188     return MCDisassembler::Fail;
5189 
5190   return S;
5191 }
5192 
5193 static DecodeStatus DecodeSTRPreImm(MCInst &Inst, unsigned Insn,
5194                                     uint64_t Address,
5195                                     const MCDisassembler *Decoder) {
5196   DecodeStatus S = MCDisassembler::Success;
5197 
5198   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5199   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5200   unsigned imm = fieldFromInstruction(Insn, 0, 12);
5201   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
5202   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
5203   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5204 
5205   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
5206 
5207   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5208     return MCDisassembler::Fail;
5209   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
5210     return MCDisassembler::Fail;
5211   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
5212     return MCDisassembler::Fail;
5213   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5214     return MCDisassembler::Fail;
5215 
5216   return S;
5217 }
5218 
5219 static DecodeStatus DecodeSTRPreReg(MCInst &Inst, unsigned Insn,
5220                                     uint64_t Address,
5221                                     const MCDisassembler *Decoder) {
5222   DecodeStatus S = MCDisassembler::Success;
5223 
5224   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5225   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5226   unsigned imm = fieldFromInstruction(Insn, 0, 12);
5227   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
5228   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
5229   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5230 
5231   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
5232 
5233   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5234     return MCDisassembler::Fail;
5235   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
5236     return MCDisassembler::Fail;
5237   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
5238     return MCDisassembler::Fail;
5239   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5240     return MCDisassembler::Fail;
5241 
5242   return S;
5243 }
5244 
5245 static DecodeStatus DecodeVLD1LN(MCInst &Inst, unsigned Insn, uint64_t Address,
5246                                  const MCDisassembler *Decoder) {
5247   DecodeStatus S = MCDisassembler::Success;
5248 
5249   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5250   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5251   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5252   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5253   unsigned size = fieldFromInstruction(Insn, 10, 2);
5254 
5255   unsigned align = 0;
5256   unsigned index = 0;
5257   switch (size) {
5258     default:
5259       return MCDisassembler::Fail;
5260     case 0:
5261       if (fieldFromInstruction(Insn, 4, 1))
5262         return MCDisassembler::Fail; // UNDEFINED
5263       index = fieldFromInstruction(Insn, 5, 3);
5264       break;
5265     case 1:
5266       if (fieldFromInstruction(Insn, 5, 1))
5267         return MCDisassembler::Fail; // UNDEFINED
5268       index = fieldFromInstruction(Insn, 6, 2);
5269       if (fieldFromInstruction(Insn, 4, 1))
5270         align = 2;
5271       break;
5272     case 2:
5273       if (fieldFromInstruction(Insn, 6, 1))
5274         return MCDisassembler::Fail; // UNDEFINED
5275       index = fieldFromInstruction(Insn, 7, 1);
5276 
5277       switch (fieldFromInstruction(Insn, 4, 2)) {
5278         case 0 :
5279           align = 0; break;
5280         case 3:
5281           align = 4; break;
5282         default:
5283           return MCDisassembler::Fail;
5284       }
5285       break;
5286   }
5287 
5288   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5289     return MCDisassembler::Fail;
5290   if (Rm != 0xF) { // Writeback
5291     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5292       return MCDisassembler::Fail;
5293   }
5294   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5295     return MCDisassembler::Fail;
5296   Inst.addOperand(MCOperand::createImm(align));
5297   if (Rm != 0xF) {
5298     if (Rm != 0xD) {
5299       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5300         return MCDisassembler::Fail;
5301     } else
5302       Inst.addOperand(MCOperand::createReg(0));
5303   }
5304 
5305   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5306     return MCDisassembler::Fail;
5307   Inst.addOperand(MCOperand::createImm(index));
5308 
5309   return S;
5310 }
5311 
5312 static DecodeStatus DecodeVST1LN(MCInst &Inst, unsigned Insn, uint64_t Address,
5313                                  const MCDisassembler *Decoder) {
5314   DecodeStatus S = MCDisassembler::Success;
5315 
5316   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5317   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5318   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5319   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5320   unsigned size = fieldFromInstruction(Insn, 10, 2);
5321 
5322   unsigned align = 0;
5323   unsigned index = 0;
5324   switch (size) {
5325     default:
5326       return MCDisassembler::Fail;
5327     case 0:
5328       if (fieldFromInstruction(Insn, 4, 1))
5329         return MCDisassembler::Fail; // UNDEFINED
5330       index = fieldFromInstruction(Insn, 5, 3);
5331       break;
5332     case 1:
5333       if (fieldFromInstruction(Insn, 5, 1))
5334         return MCDisassembler::Fail; // UNDEFINED
5335       index = fieldFromInstruction(Insn, 6, 2);
5336       if (fieldFromInstruction(Insn, 4, 1))
5337         align = 2;
5338       break;
5339     case 2:
5340       if (fieldFromInstruction(Insn, 6, 1))
5341         return MCDisassembler::Fail; // UNDEFINED
5342       index = fieldFromInstruction(Insn, 7, 1);
5343 
5344       switch (fieldFromInstruction(Insn, 4, 2)) {
5345         case 0:
5346           align = 0; break;
5347         case 3:
5348           align = 4; break;
5349         default:
5350           return MCDisassembler::Fail;
5351       }
5352       break;
5353   }
5354 
5355   if (Rm != 0xF) { // Writeback
5356     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5357     return MCDisassembler::Fail;
5358   }
5359   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5360     return MCDisassembler::Fail;
5361   Inst.addOperand(MCOperand::createImm(align));
5362   if (Rm != 0xF) {
5363     if (Rm != 0xD) {
5364       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5365     return MCDisassembler::Fail;
5366     } else
5367       Inst.addOperand(MCOperand::createReg(0));
5368   }
5369 
5370   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5371     return MCDisassembler::Fail;
5372   Inst.addOperand(MCOperand::createImm(index));
5373 
5374   return S;
5375 }
5376 
5377 static DecodeStatus DecodeVLD2LN(MCInst &Inst, unsigned Insn, uint64_t Address,
5378                                  const MCDisassembler *Decoder) {
5379   DecodeStatus S = MCDisassembler::Success;
5380 
5381   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5382   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5383   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5384   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5385   unsigned size = fieldFromInstruction(Insn, 10, 2);
5386 
5387   unsigned align = 0;
5388   unsigned index = 0;
5389   unsigned inc = 1;
5390   switch (size) {
5391     default:
5392       return MCDisassembler::Fail;
5393     case 0:
5394       index = fieldFromInstruction(Insn, 5, 3);
5395       if (fieldFromInstruction(Insn, 4, 1))
5396         align = 2;
5397       break;
5398     case 1:
5399       index = fieldFromInstruction(Insn, 6, 2);
5400       if (fieldFromInstruction(Insn, 4, 1))
5401         align = 4;
5402       if (fieldFromInstruction(Insn, 5, 1))
5403         inc = 2;
5404       break;
5405     case 2:
5406       if (fieldFromInstruction(Insn, 5, 1))
5407         return MCDisassembler::Fail; // UNDEFINED
5408       index = fieldFromInstruction(Insn, 7, 1);
5409       if (fieldFromInstruction(Insn, 4, 1) != 0)
5410         align = 8;
5411       if (fieldFromInstruction(Insn, 6, 1))
5412         inc = 2;
5413       break;
5414   }
5415 
5416   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5417     return MCDisassembler::Fail;
5418   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5419     return MCDisassembler::Fail;
5420   if (Rm != 0xF) { // Writeback
5421     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5422       return MCDisassembler::Fail;
5423   }
5424   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5425     return MCDisassembler::Fail;
5426   Inst.addOperand(MCOperand::createImm(align));
5427   if (Rm != 0xF) {
5428     if (Rm != 0xD) {
5429       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5430         return MCDisassembler::Fail;
5431     } else
5432       Inst.addOperand(MCOperand::createReg(0));
5433   }
5434 
5435   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5436     return MCDisassembler::Fail;
5437   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5438     return MCDisassembler::Fail;
5439   Inst.addOperand(MCOperand::createImm(index));
5440 
5441   return S;
5442 }
5443 
5444 static DecodeStatus DecodeVST2LN(MCInst &Inst, unsigned Insn, uint64_t Address,
5445                                  const MCDisassembler *Decoder) {
5446   DecodeStatus S = MCDisassembler::Success;
5447 
5448   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5449   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5450   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5451   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5452   unsigned size = fieldFromInstruction(Insn, 10, 2);
5453 
5454   unsigned align = 0;
5455   unsigned index = 0;
5456   unsigned inc = 1;
5457   switch (size) {
5458     default:
5459       return MCDisassembler::Fail;
5460     case 0:
5461       index = fieldFromInstruction(Insn, 5, 3);
5462       if (fieldFromInstruction(Insn, 4, 1))
5463         align = 2;
5464       break;
5465     case 1:
5466       index = fieldFromInstruction(Insn, 6, 2);
5467       if (fieldFromInstruction(Insn, 4, 1))
5468         align = 4;
5469       if (fieldFromInstruction(Insn, 5, 1))
5470         inc = 2;
5471       break;
5472     case 2:
5473       if (fieldFromInstruction(Insn, 5, 1))
5474         return MCDisassembler::Fail; // UNDEFINED
5475       index = fieldFromInstruction(Insn, 7, 1);
5476       if (fieldFromInstruction(Insn, 4, 1) != 0)
5477         align = 8;
5478       if (fieldFromInstruction(Insn, 6, 1))
5479         inc = 2;
5480       break;
5481   }
5482 
5483   if (Rm != 0xF) { // Writeback
5484     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5485       return MCDisassembler::Fail;
5486   }
5487   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5488     return MCDisassembler::Fail;
5489   Inst.addOperand(MCOperand::createImm(align));
5490   if (Rm != 0xF) {
5491     if (Rm != 0xD) {
5492       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5493         return MCDisassembler::Fail;
5494     } else
5495       Inst.addOperand(MCOperand::createReg(0));
5496   }
5497 
5498   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5499     return MCDisassembler::Fail;
5500   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5501     return MCDisassembler::Fail;
5502   Inst.addOperand(MCOperand::createImm(index));
5503 
5504   return S;
5505 }
5506 
5507 static DecodeStatus DecodeVLD3LN(MCInst &Inst, unsigned Insn, uint64_t Address,
5508                                  const MCDisassembler *Decoder) {
5509   DecodeStatus S = MCDisassembler::Success;
5510 
5511   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5512   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5513   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5514   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5515   unsigned size = fieldFromInstruction(Insn, 10, 2);
5516 
5517   unsigned align = 0;
5518   unsigned index = 0;
5519   unsigned inc = 1;
5520   switch (size) {
5521     default:
5522       return MCDisassembler::Fail;
5523     case 0:
5524       if (fieldFromInstruction(Insn, 4, 1))
5525         return MCDisassembler::Fail; // UNDEFINED
5526       index = fieldFromInstruction(Insn, 5, 3);
5527       break;
5528     case 1:
5529       if (fieldFromInstruction(Insn, 4, 1))
5530         return MCDisassembler::Fail; // UNDEFINED
5531       index = fieldFromInstruction(Insn, 6, 2);
5532       if (fieldFromInstruction(Insn, 5, 1))
5533         inc = 2;
5534       break;
5535     case 2:
5536       if (fieldFromInstruction(Insn, 4, 2))
5537         return MCDisassembler::Fail; // UNDEFINED
5538       index = fieldFromInstruction(Insn, 7, 1);
5539       if (fieldFromInstruction(Insn, 6, 1))
5540         inc = 2;
5541       break;
5542   }
5543 
5544   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5545     return MCDisassembler::Fail;
5546   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5547     return MCDisassembler::Fail;
5548   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5549     return MCDisassembler::Fail;
5550 
5551   if (Rm != 0xF) { // Writeback
5552     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5553     return MCDisassembler::Fail;
5554   }
5555   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5556     return MCDisassembler::Fail;
5557   Inst.addOperand(MCOperand::createImm(align));
5558   if (Rm != 0xF) {
5559     if (Rm != 0xD) {
5560       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5561     return MCDisassembler::Fail;
5562     } else
5563       Inst.addOperand(MCOperand::createReg(0));
5564   }
5565 
5566   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5567     return MCDisassembler::Fail;
5568   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5569     return MCDisassembler::Fail;
5570   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5571     return MCDisassembler::Fail;
5572   Inst.addOperand(MCOperand::createImm(index));
5573 
5574   return S;
5575 }
5576 
5577 static DecodeStatus DecodeVST3LN(MCInst &Inst, unsigned Insn, uint64_t Address,
5578                                  const MCDisassembler *Decoder) {
5579   DecodeStatus S = MCDisassembler::Success;
5580 
5581   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5582   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5583   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5584   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5585   unsigned size = fieldFromInstruction(Insn, 10, 2);
5586 
5587   unsigned align = 0;
5588   unsigned index = 0;
5589   unsigned inc = 1;
5590   switch (size) {
5591     default:
5592       return MCDisassembler::Fail;
5593     case 0:
5594       if (fieldFromInstruction(Insn, 4, 1))
5595         return MCDisassembler::Fail; // UNDEFINED
5596       index = fieldFromInstruction(Insn, 5, 3);
5597       break;
5598     case 1:
5599       if (fieldFromInstruction(Insn, 4, 1))
5600         return MCDisassembler::Fail; // UNDEFINED
5601       index = fieldFromInstruction(Insn, 6, 2);
5602       if (fieldFromInstruction(Insn, 5, 1))
5603         inc = 2;
5604       break;
5605     case 2:
5606       if (fieldFromInstruction(Insn, 4, 2))
5607         return MCDisassembler::Fail; // UNDEFINED
5608       index = fieldFromInstruction(Insn, 7, 1);
5609       if (fieldFromInstruction(Insn, 6, 1))
5610         inc = 2;
5611       break;
5612   }
5613 
5614   if (Rm != 0xF) { // Writeback
5615     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5616     return MCDisassembler::Fail;
5617   }
5618   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5619     return MCDisassembler::Fail;
5620   Inst.addOperand(MCOperand::createImm(align));
5621   if (Rm != 0xF) {
5622     if (Rm != 0xD) {
5623       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5624     return MCDisassembler::Fail;
5625     } else
5626       Inst.addOperand(MCOperand::createReg(0));
5627   }
5628 
5629   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5630     return MCDisassembler::Fail;
5631   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5632     return MCDisassembler::Fail;
5633   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5634     return MCDisassembler::Fail;
5635   Inst.addOperand(MCOperand::createImm(index));
5636 
5637   return S;
5638 }
5639 
5640 static DecodeStatus DecodeVLD4LN(MCInst &Inst, unsigned Insn, uint64_t Address,
5641                                  const MCDisassembler *Decoder) {
5642   DecodeStatus S = MCDisassembler::Success;
5643 
5644   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5645   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5646   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5647   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5648   unsigned size = fieldFromInstruction(Insn, 10, 2);
5649 
5650   unsigned align = 0;
5651   unsigned index = 0;
5652   unsigned inc = 1;
5653   switch (size) {
5654     default:
5655       return MCDisassembler::Fail;
5656     case 0:
5657       if (fieldFromInstruction(Insn, 4, 1))
5658         align = 4;
5659       index = fieldFromInstruction(Insn, 5, 3);
5660       break;
5661     case 1:
5662       if (fieldFromInstruction(Insn, 4, 1))
5663         align = 8;
5664       index = fieldFromInstruction(Insn, 6, 2);
5665       if (fieldFromInstruction(Insn, 5, 1))
5666         inc = 2;
5667       break;
5668     case 2:
5669       switch (fieldFromInstruction(Insn, 4, 2)) {
5670         case 0:
5671           align = 0; break;
5672         case 3:
5673           return MCDisassembler::Fail;
5674         default:
5675           align = 4 << fieldFromInstruction(Insn, 4, 2); break;
5676       }
5677 
5678       index = fieldFromInstruction(Insn, 7, 1);
5679       if (fieldFromInstruction(Insn, 6, 1))
5680         inc = 2;
5681       break;
5682   }
5683 
5684   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5685     return MCDisassembler::Fail;
5686   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5687     return MCDisassembler::Fail;
5688   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5689     return MCDisassembler::Fail;
5690   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5691     return MCDisassembler::Fail;
5692 
5693   if (Rm != 0xF) { // Writeback
5694     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5695       return MCDisassembler::Fail;
5696   }
5697   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5698     return MCDisassembler::Fail;
5699   Inst.addOperand(MCOperand::createImm(align));
5700   if (Rm != 0xF) {
5701     if (Rm != 0xD) {
5702       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5703         return MCDisassembler::Fail;
5704     } else
5705       Inst.addOperand(MCOperand::createReg(0));
5706   }
5707 
5708   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5709     return MCDisassembler::Fail;
5710   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5711     return MCDisassembler::Fail;
5712   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5713     return MCDisassembler::Fail;
5714   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5715     return MCDisassembler::Fail;
5716   Inst.addOperand(MCOperand::createImm(index));
5717 
5718   return S;
5719 }
5720 
5721 static DecodeStatus DecodeVST4LN(MCInst &Inst, unsigned Insn, uint64_t Address,
5722                                  const MCDisassembler *Decoder) {
5723   DecodeStatus S = MCDisassembler::Success;
5724 
5725   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5726   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5727   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5728   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5729   unsigned size = fieldFromInstruction(Insn, 10, 2);
5730 
5731   unsigned align = 0;
5732   unsigned index = 0;
5733   unsigned inc = 1;
5734   switch (size) {
5735     default:
5736       return MCDisassembler::Fail;
5737     case 0:
5738       if (fieldFromInstruction(Insn, 4, 1))
5739         align = 4;
5740       index = fieldFromInstruction(Insn, 5, 3);
5741       break;
5742     case 1:
5743       if (fieldFromInstruction(Insn, 4, 1))
5744         align = 8;
5745       index = fieldFromInstruction(Insn, 6, 2);
5746       if (fieldFromInstruction(Insn, 5, 1))
5747         inc = 2;
5748       break;
5749     case 2:
5750       switch (fieldFromInstruction(Insn, 4, 2)) {
5751         case 0:
5752           align = 0; break;
5753         case 3:
5754           return MCDisassembler::Fail;
5755         default:
5756           align = 4 << fieldFromInstruction(Insn, 4, 2); break;
5757       }
5758 
5759       index = fieldFromInstruction(Insn, 7, 1);
5760       if (fieldFromInstruction(Insn, 6, 1))
5761         inc = 2;
5762       break;
5763   }
5764 
5765   if (Rm != 0xF) { // Writeback
5766     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5767     return MCDisassembler::Fail;
5768   }
5769   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5770     return MCDisassembler::Fail;
5771   Inst.addOperand(MCOperand::createImm(align));
5772   if (Rm != 0xF) {
5773     if (Rm != 0xD) {
5774       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5775     return MCDisassembler::Fail;
5776     } else
5777       Inst.addOperand(MCOperand::createReg(0));
5778   }
5779 
5780   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5781     return MCDisassembler::Fail;
5782   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5783     return MCDisassembler::Fail;
5784   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5785     return MCDisassembler::Fail;
5786   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5787     return MCDisassembler::Fail;
5788   Inst.addOperand(MCOperand::createImm(index));
5789 
5790   return S;
5791 }
5792 
5793 static DecodeStatus DecodeVMOVSRR(MCInst &Inst, unsigned Insn, uint64_t Address,
5794                                   const MCDisassembler *Decoder) {
5795   DecodeStatus S = MCDisassembler::Success;
5796   unsigned Rt  = fieldFromInstruction(Insn, 12, 4);
5797   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
5798   unsigned Rm  = fieldFromInstruction(Insn,  5, 1);
5799   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5800   Rm |= fieldFromInstruction(Insn, 0, 4) << 1;
5801 
5802   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
5803     S = MCDisassembler::SoftFail;
5804 
5805   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
5806     return MCDisassembler::Fail;
5807   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
5808     return MCDisassembler::Fail;
5809   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
5810     return MCDisassembler::Fail;
5811   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
5812     return MCDisassembler::Fail;
5813   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5814     return MCDisassembler::Fail;
5815 
5816   return S;
5817 }
5818 
5819 static DecodeStatus DecodeVMOVRRS(MCInst &Inst, unsigned Insn, uint64_t Address,
5820                                   const MCDisassembler *Decoder) {
5821   DecodeStatus S = MCDisassembler::Success;
5822   unsigned Rt  = fieldFromInstruction(Insn, 12, 4);
5823   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
5824   unsigned Rm  = fieldFromInstruction(Insn,  5, 1);
5825   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5826   Rm |= fieldFromInstruction(Insn, 0, 4) << 1;
5827 
5828   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
5829     S = MCDisassembler::SoftFail;
5830 
5831   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
5832     return MCDisassembler::Fail;
5833   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
5834     return MCDisassembler::Fail;
5835   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
5836     return MCDisassembler::Fail;
5837   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
5838     return MCDisassembler::Fail;
5839   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5840     return MCDisassembler::Fail;
5841 
5842   return S;
5843 }
5844 
5845 static DecodeStatus DecodeIT(MCInst &Inst, unsigned Insn, uint64_t Address,
5846                              const MCDisassembler *Decoder) {
5847   DecodeStatus S = MCDisassembler::Success;
5848   unsigned pred = fieldFromInstruction(Insn, 4, 4);
5849   unsigned mask = fieldFromInstruction(Insn, 0, 4);
5850 
5851   if (pred == 0xF) {
5852     pred = 0xE;
5853     S = MCDisassembler::SoftFail;
5854   }
5855 
5856   if (mask == 0x0)
5857     return MCDisassembler::Fail;
5858 
5859   // IT masks are encoded as a sequence of replacement low-order bits
5860   // for the condition code. So if the low bit of the starting
5861   // condition code is 1, then we have to flip all the bits above the
5862   // terminating bit (which is the lowest 1 bit).
5863   if (pred & 1) {
5864     unsigned LowBit = mask & -mask;
5865     unsigned BitsAboveLowBit = 0xF & (-LowBit << 1);
5866     mask ^= BitsAboveLowBit;
5867   }
5868 
5869   Inst.addOperand(MCOperand::createImm(pred));
5870   Inst.addOperand(MCOperand::createImm(mask));
5871   return S;
5872 }
5873 
5874 static DecodeStatus DecodeT2LDRDPreInstruction(MCInst &Inst, unsigned Insn,
5875                                                uint64_t Address,
5876                                                const MCDisassembler *Decoder) {
5877   DecodeStatus S = MCDisassembler::Success;
5878 
5879   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5880   unsigned Rt2 = fieldFromInstruction(Insn, 8, 4);
5881   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5882   unsigned addr = fieldFromInstruction(Insn, 0, 8);
5883   unsigned W = fieldFromInstruction(Insn, 21, 1);
5884   unsigned U = fieldFromInstruction(Insn, 23, 1);
5885   unsigned P = fieldFromInstruction(Insn, 24, 1);
5886   bool writeback = (W == 1) | (P == 0);
5887 
5888   addr |= (U << 8) | (Rn << 9);
5889 
5890   if (writeback && (Rn == Rt || Rn == Rt2))
5891     Check(S, MCDisassembler::SoftFail);
5892   if (Rt == Rt2)
5893     Check(S, MCDisassembler::SoftFail);
5894 
5895   // Rt
5896   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
5897     return MCDisassembler::Fail;
5898   // Rt2
5899   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
5900     return MCDisassembler::Fail;
5901   // Writeback operand
5902   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
5903     return MCDisassembler::Fail;
5904   // addr
5905   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
5906     return MCDisassembler::Fail;
5907 
5908   return S;
5909 }
5910 
5911 static DecodeStatus DecodeT2STRDPreInstruction(MCInst &Inst, unsigned Insn,
5912                                                uint64_t Address,
5913                                                const MCDisassembler *Decoder) {
5914   DecodeStatus S = MCDisassembler::Success;
5915 
5916   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5917   unsigned Rt2 = fieldFromInstruction(Insn, 8, 4);
5918   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5919   unsigned addr = fieldFromInstruction(Insn, 0, 8);
5920   unsigned W = fieldFromInstruction(Insn, 21, 1);
5921   unsigned U = fieldFromInstruction(Insn, 23, 1);
5922   unsigned P = fieldFromInstruction(Insn, 24, 1);
5923   bool writeback = (W == 1) | (P == 0);
5924 
5925   addr |= (U << 8) | (Rn << 9);
5926 
5927   if (writeback && (Rn == Rt || Rn == Rt2))
5928     Check(S, MCDisassembler::SoftFail);
5929 
5930   // Writeback operand
5931   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
5932     return MCDisassembler::Fail;
5933   // Rt
5934   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
5935     return MCDisassembler::Fail;
5936   // Rt2
5937   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
5938     return MCDisassembler::Fail;
5939   // addr
5940   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
5941     return MCDisassembler::Fail;
5942 
5943   return S;
5944 }
5945 
5946 static DecodeStatus DecodeT2Adr(MCInst &Inst, uint32_t Insn, uint64_t Address,
5947                                 const MCDisassembler *Decoder) {
5948   unsigned sign1 = fieldFromInstruction(Insn, 21, 1);
5949   unsigned sign2 = fieldFromInstruction(Insn, 23, 1);
5950   if (sign1 != sign2) return MCDisassembler::Fail;
5951   const unsigned Rd = fieldFromInstruction(Insn, 8, 4);
5952   assert(Inst.getNumOperands() == 0 && "We should receive an empty Inst");
5953   DecodeStatus S = DecoderGPRRegisterClass(Inst, Rd, Address, Decoder);
5954 
5955   unsigned Val = fieldFromInstruction(Insn, 0, 8);
5956   Val |= fieldFromInstruction(Insn, 12, 3) << 8;
5957   Val |= fieldFromInstruction(Insn, 26, 1) << 11;
5958   // If sign, then it is decreasing the address.
5959   if (sign1) {
5960     // Following ARMv7 Architecture Manual, when the offset
5961     // is zero, it is decoded as a subw, not as a adr.w
5962     if (!Val) {
5963       Inst.setOpcode(ARM::t2SUBri12);
5964       Inst.addOperand(MCOperand::createReg(ARM::PC));
5965     } else
5966       Val = -Val;
5967   }
5968   Inst.addOperand(MCOperand::createImm(Val));
5969   return S;
5970 }
5971 
5972 static DecodeStatus DecodeT2ShifterImmOperand(MCInst &Inst, uint32_t Val,
5973                                               uint64_t Address,
5974                                               const MCDisassembler *Decoder) {
5975   DecodeStatus S = MCDisassembler::Success;
5976 
5977   // Shift of "asr #32" is not allowed in Thumb2 mode.
5978   if (Val == 0x20) S = MCDisassembler::Fail;
5979   Inst.addOperand(MCOperand::createImm(Val));
5980   return S;
5981 }
5982 
5983 static DecodeStatus DecodeSwap(MCInst &Inst, unsigned Insn, uint64_t Address,
5984                                const MCDisassembler *Decoder) {
5985   unsigned Rt   = fieldFromInstruction(Insn, 12, 4);
5986   unsigned Rt2  = fieldFromInstruction(Insn, 0,  4);
5987   unsigned Rn   = fieldFromInstruction(Insn, 16, 4);
5988   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5989 
5990   if (pred == 0xF)
5991     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
5992 
5993   DecodeStatus S = MCDisassembler::Success;
5994 
5995   if (Rt == Rn || Rn == Rt2)
5996     S = MCDisassembler::SoftFail;
5997 
5998   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5999     return MCDisassembler::Fail;
6000   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
6001     return MCDisassembler::Fail;
6002   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
6003     return MCDisassembler::Fail;
6004   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
6005     return MCDisassembler::Fail;
6006 
6007   return S;
6008 }
6009 
6010 static DecodeStatus DecodeVCVTD(MCInst &Inst, unsigned Insn, uint64_t Address,
6011                                 const MCDisassembler *Decoder) {
6012   const FeatureBitset &featureBits =
6013       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
6014   bool hasFullFP16 = featureBits[ARM::FeatureFullFP16];
6015 
6016   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
6017   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
6018   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
6019   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
6020   unsigned imm = fieldFromInstruction(Insn, 16, 6);
6021   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
6022   unsigned op = fieldFromInstruction(Insn, 5, 1);
6023 
6024   DecodeStatus S = MCDisassembler::Success;
6025 
6026   // If the top 3 bits of imm are clear, this is a VMOV (immediate)
6027   if (!(imm & 0x38)) {
6028     if (cmode == 0xF) {
6029       if (op == 1) return MCDisassembler::Fail;
6030       Inst.setOpcode(ARM::VMOVv2f32);
6031     }
6032     if (hasFullFP16) {
6033       if (cmode == 0xE) {
6034         if (op == 1) {
6035           Inst.setOpcode(ARM::VMOVv1i64);
6036         } else {
6037           Inst.setOpcode(ARM::VMOVv8i8);
6038         }
6039       }
6040       if (cmode == 0xD) {
6041         if (op == 1) {
6042           Inst.setOpcode(ARM::VMVNv2i32);
6043         } else {
6044           Inst.setOpcode(ARM::VMOVv2i32);
6045         }
6046       }
6047       if (cmode == 0xC) {
6048         if (op == 1) {
6049           Inst.setOpcode(ARM::VMVNv2i32);
6050         } else {
6051           Inst.setOpcode(ARM::VMOVv2i32);
6052         }
6053       }
6054     }
6055     return DecodeVMOVModImmInstruction(Inst, Insn, Address, Decoder);
6056   }
6057 
6058   if (!(imm & 0x20)) return MCDisassembler::Fail;
6059 
6060   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
6061     return MCDisassembler::Fail;
6062   if (!Check(S, DecodeDPRRegisterClass(Inst, Vm, Address, Decoder)))
6063     return MCDisassembler::Fail;
6064   Inst.addOperand(MCOperand::createImm(64 - imm));
6065 
6066   return S;
6067 }
6068 
6069 static DecodeStatus DecodeVCVTQ(MCInst &Inst, unsigned Insn, uint64_t Address,
6070                                 const MCDisassembler *Decoder) {
6071   const FeatureBitset &featureBits =
6072       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
6073   bool hasFullFP16 = featureBits[ARM::FeatureFullFP16];
6074 
6075   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
6076   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
6077   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
6078   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
6079   unsigned imm = fieldFromInstruction(Insn, 16, 6);
6080   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
6081   unsigned op = fieldFromInstruction(Insn, 5, 1);
6082 
6083   DecodeStatus S = MCDisassembler::Success;
6084 
6085   // If the top 3 bits of imm are clear, this is a VMOV (immediate)
6086   if (!(imm & 0x38)) {
6087     if (cmode == 0xF) {
6088       if (op == 1) return MCDisassembler::Fail;
6089       Inst.setOpcode(ARM::VMOVv4f32);
6090     }
6091     if (hasFullFP16) {
6092       if (cmode == 0xE) {
6093         if (op == 1) {
6094           Inst.setOpcode(ARM::VMOVv2i64);
6095         } else {
6096           Inst.setOpcode(ARM::VMOVv16i8);
6097         }
6098       }
6099       if (cmode == 0xD) {
6100         if (op == 1) {
6101           Inst.setOpcode(ARM::VMVNv4i32);
6102         } else {
6103           Inst.setOpcode(ARM::VMOVv4i32);
6104         }
6105       }
6106       if (cmode == 0xC) {
6107         if (op == 1) {
6108           Inst.setOpcode(ARM::VMVNv4i32);
6109         } else {
6110           Inst.setOpcode(ARM::VMOVv4i32);
6111         }
6112       }
6113     }
6114     return DecodeVMOVModImmInstruction(Inst, Insn, Address, Decoder);
6115   }
6116 
6117   if (!(imm & 0x20)) return MCDisassembler::Fail;
6118 
6119   if (!Check(S, DecodeQPRRegisterClass(Inst, Vd, Address, Decoder)))
6120     return MCDisassembler::Fail;
6121   if (!Check(S, DecodeQPRRegisterClass(Inst, Vm, Address, Decoder)))
6122     return MCDisassembler::Fail;
6123   Inst.addOperand(MCOperand::createImm(64 - imm));
6124 
6125   return S;
6126 }
6127 
6128 static DecodeStatus
6129 DecodeNEONComplexLane64Instruction(MCInst &Inst, unsigned Insn,
6130                                    uint64_t Address,
6131                                    const MCDisassembler *Decoder) {
6132   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
6133   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
6134   unsigned Vn = (fieldFromInstruction(Insn, 16, 4) << 0);
6135   Vn |= (fieldFromInstruction(Insn, 7, 1) << 4);
6136   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
6137   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
6138   unsigned q = (fieldFromInstruction(Insn, 6, 1) << 0);
6139   unsigned rotate = (fieldFromInstruction(Insn, 20, 2) << 0);
6140 
6141   DecodeStatus S = MCDisassembler::Success;
6142 
6143   auto DestRegDecoder = q ? DecodeQPRRegisterClass : DecodeDPRRegisterClass;
6144 
6145   if (!Check(S, DestRegDecoder(Inst, Vd, Address, Decoder)))
6146     return MCDisassembler::Fail;
6147   if (!Check(S, DestRegDecoder(Inst, Vd, Address, Decoder)))
6148     return MCDisassembler::Fail;
6149   if (!Check(S, DestRegDecoder(Inst, Vn, Address, Decoder)))
6150     return MCDisassembler::Fail;
6151   if (!Check(S, DecodeDPRRegisterClass(Inst, Vm, Address, Decoder)))
6152     return MCDisassembler::Fail;
6153   // The lane index does not have any bits in the encoding, because it can only
6154   // be 0.
6155   Inst.addOperand(MCOperand::createImm(0));
6156   Inst.addOperand(MCOperand::createImm(rotate));
6157 
6158   return S;
6159 }
6160 
6161 static DecodeStatus DecodeLDR(MCInst &Inst, unsigned Val, uint64_t Address,
6162                               const MCDisassembler *Decoder) {
6163   DecodeStatus S = MCDisassembler::Success;
6164 
6165   unsigned Rn = fieldFromInstruction(Val, 16, 4);
6166   unsigned Rt = fieldFromInstruction(Val, 12, 4);
6167   unsigned Rm = fieldFromInstruction(Val, 0, 4);
6168   Rm |= (fieldFromInstruction(Val, 23, 1) << 4);
6169   unsigned Cond = fieldFromInstruction(Val, 28, 4);
6170 
6171   if (fieldFromInstruction(Val, 8, 4) != 0 || Rn == Rt)
6172     S = MCDisassembler::SoftFail;
6173 
6174   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
6175     return MCDisassembler::Fail;
6176   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
6177     return MCDisassembler::Fail;
6178   if (!Check(S, DecodeAddrMode7Operand(Inst, Rn, Address, Decoder)))
6179     return MCDisassembler::Fail;
6180   if (!Check(S, DecodePostIdxReg(Inst, Rm, Address, Decoder)))
6181     return MCDisassembler::Fail;
6182   if (!Check(S, DecodePredicateOperand(Inst, Cond, Address, Decoder)))
6183     return MCDisassembler::Fail;
6184 
6185   return S;
6186 }
6187 
6188 static DecodeStatus DecoderForMRRC2AndMCRR2(MCInst &Inst, unsigned Val,
6189                                             uint64_t Address,
6190                                             const MCDisassembler *Decoder) {
6191   DecodeStatus S = MCDisassembler::Success;
6192 
6193   unsigned CRm = fieldFromInstruction(Val, 0, 4);
6194   unsigned opc1 = fieldFromInstruction(Val, 4, 4);
6195   unsigned cop = fieldFromInstruction(Val, 8, 4);
6196   unsigned Rt = fieldFromInstruction(Val, 12, 4);
6197   unsigned Rt2 = fieldFromInstruction(Val, 16, 4);
6198 
6199   if ((cop & ~0x1) == 0xa)
6200     return MCDisassembler::Fail;
6201 
6202   if (Rt == Rt2)
6203     S = MCDisassembler::SoftFail;
6204 
6205   // We have to check if the instruction is MRRC2
6206   // or MCRR2 when constructing the operands for
6207   // Inst. Reason is because MRRC2 stores to two
6208   // registers so it's tablegen desc has has two
6209   // outputs whereas MCRR doesn't store to any
6210   // registers so all of it's operands are listed
6211   // as inputs, therefore the operand order for
6212   // MRRC2 needs to be [Rt, Rt2, cop, opc1, CRm]
6213   // and MCRR2 operand order is [cop, opc1, Rt, Rt2, CRm]
6214 
6215   if (Inst.getOpcode() == ARM::MRRC2) {
6216     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
6217       return MCDisassembler::Fail;
6218     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
6219       return MCDisassembler::Fail;
6220   }
6221   Inst.addOperand(MCOperand::createImm(cop));
6222   Inst.addOperand(MCOperand::createImm(opc1));
6223   if (Inst.getOpcode() == ARM::MCRR2) {
6224     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
6225       return MCDisassembler::Fail;
6226     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
6227       return MCDisassembler::Fail;
6228   }
6229   Inst.addOperand(MCOperand::createImm(CRm));
6230 
6231   return S;
6232 }
6233 
6234 static DecodeStatus DecodeForVMRSandVMSR(MCInst &Inst, unsigned Val,
6235                                          uint64_t Address,
6236                                          const MCDisassembler *Decoder) {
6237   const FeatureBitset &featureBits =
6238       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
6239   DecodeStatus S = MCDisassembler::Success;
6240 
6241   // Add explicit operand for the destination sysreg, for cases where
6242   // we have to model it for code generation purposes.
6243   switch (Inst.getOpcode()) {
6244   case ARM::VMSR_FPSCR_NZCVQC:
6245     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
6246     break;
6247   case ARM::VMSR_P0:
6248     Inst.addOperand(MCOperand::createReg(ARM::VPR));
6249     break;
6250   }
6251 
6252   if (Inst.getOpcode() != ARM::FMSTAT) {
6253     unsigned Rt = fieldFromInstruction(Val, 12, 4);
6254 
6255     if (featureBits[ARM::ModeThumb] && !featureBits[ARM::HasV8Ops]) {
6256       if (Rt == 13 || Rt == 15)
6257         S = MCDisassembler::SoftFail;
6258       Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder));
6259     } else
6260       Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder));
6261   }
6262 
6263   // Add explicit operand for the source sysreg, similarly to above.
6264   switch (Inst.getOpcode()) {
6265   case ARM::VMRS_FPSCR_NZCVQC:
6266     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
6267     break;
6268   case ARM::VMRS_P0:
6269     Inst.addOperand(MCOperand::createReg(ARM::VPR));
6270     break;
6271   }
6272 
6273   if (featureBits[ARM::ModeThumb]) {
6274     Inst.addOperand(MCOperand::createImm(ARMCC::AL));
6275     Inst.addOperand(MCOperand::createReg(0));
6276   } else {
6277     unsigned pred = fieldFromInstruction(Val, 28, 4);
6278     if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
6279       return MCDisassembler::Fail;
6280   }
6281 
6282   return S;
6283 }
6284 
6285 template <bool isSigned, bool isNeg, bool zeroPermitted, int size>
6286 static DecodeStatus DecodeBFLabelOperand(MCInst &Inst, unsigned Val,
6287                                          uint64_t Address,
6288                                          const MCDisassembler *Decoder) {
6289   DecodeStatus S = MCDisassembler::Success;
6290   if (Val == 0 && !zeroPermitted)
6291     S = MCDisassembler::Fail;
6292 
6293   uint64_t DecVal;
6294   if (isSigned)
6295     DecVal = SignExtend32<size + 1>(Val << 1);
6296   else
6297     DecVal = (Val << 1);
6298 
6299   if (!tryAddingSymbolicOperand(Address, Address + DecVal + 4, true, 4, Inst,
6300                                 Decoder))
6301     Inst.addOperand(MCOperand::createImm(isNeg ? -DecVal : DecVal));
6302   return S;
6303 }
6304 
6305 static DecodeStatus DecodeBFAfterTargetOperand(MCInst &Inst, unsigned Val,
6306                                                uint64_t Address,
6307                                                const MCDisassembler *Decoder) {
6308 
6309   uint64_t LocImm = Inst.getOperand(0).getImm();
6310   Val = LocImm + (2 << Val);
6311   if (!tryAddingSymbolicOperand(Address, Address + Val + 4, true, 4, Inst,
6312                                 Decoder))
6313     Inst.addOperand(MCOperand::createImm(Val));
6314   return MCDisassembler::Success;
6315 }
6316 
6317 static DecodeStatus DecodePredNoALOperand(MCInst &Inst, unsigned Val,
6318                                           uint64_t Address,
6319                                           const MCDisassembler *Decoder) {
6320   if (Val >= ARMCC::AL)  // also exclude the non-condition NV
6321     return MCDisassembler::Fail;
6322   Inst.addOperand(MCOperand::createImm(Val));
6323   return MCDisassembler::Success;
6324 }
6325 
6326 static DecodeStatus DecodeLOLoop(MCInst &Inst, unsigned Insn, uint64_t Address,
6327                                  const MCDisassembler *Decoder) {
6328   DecodeStatus S = MCDisassembler::Success;
6329 
6330   if (Inst.getOpcode() == ARM::MVE_LCTP)
6331     return S;
6332 
6333   unsigned Imm = fieldFromInstruction(Insn, 11, 1) |
6334                  fieldFromInstruction(Insn, 1, 10) << 1;
6335   switch (Inst.getOpcode()) {
6336   case ARM::t2LEUpdate:
6337   case ARM::MVE_LETP:
6338     Inst.addOperand(MCOperand::createReg(ARM::LR));
6339     Inst.addOperand(MCOperand::createReg(ARM::LR));
6340     LLVM_FALLTHROUGH;
6341   case ARM::t2LE:
6342     if (!Check(S, DecodeBFLabelOperand<false, true, true, 11>(
6343                    Inst, Imm, Address, Decoder)))
6344       return MCDisassembler::Fail;
6345     break;
6346   case ARM::t2WLS:
6347   case ARM::MVE_WLSTP_8:
6348   case ARM::MVE_WLSTP_16:
6349   case ARM::MVE_WLSTP_32:
6350   case ARM::MVE_WLSTP_64:
6351     Inst.addOperand(MCOperand::createReg(ARM::LR));
6352     if (!Check(S,
6353                DecoderGPRRegisterClass(Inst, fieldFromInstruction(Insn, 16, 4),
6354                                        Address, Decoder)) ||
6355         !Check(S, DecodeBFLabelOperand<false, false, true, 11>(
6356                    Inst, Imm, Address, Decoder)))
6357       return MCDisassembler::Fail;
6358     break;
6359   case ARM::t2DLS:
6360   case ARM::MVE_DLSTP_8:
6361   case ARM::MVE_DLSTP_16:
6362   case ARM::MVE_DLSTP_32:
6363   case ARM::MVE_DLSTP_64:
6364     unsigned Rn = fieldFromInstruction(Insn, 16, 4);
6365     if (Rn == 0xF) {
6366       // Enforce all the rest of the instruction bits in LCTP, which
6367       // won't have been reliably checked based on LCTP's own tablegen
6368       // record, because we came to this decode by a roundabout route.
6369       uint32_t CanonicalLCTP = 0xF00FE001, SBZMask = 0x00300FFE;
6370       if ((Insn & ~SBZMask) != CanonicalLCTP)
6371         return MCDisassembler::Fail;   // a mandatory bit is wrong: hard fail
6372       if (Insn != CanonicalLCTP)
6373         Check(S, MCDisassembler::SoftFail); // an SBZ bit is wrong: soft fail
6374 
6375       Inst.setOpcode(ARM::MVE_LCTP);
6376     } else {
6377       Inst.addOperand(MCOperand::createReg(ARM::LR));
6378       if (!Check(S, DecoderGPRRegisterClass(Inst,
6379                                             fieldFromInstruction(Insn, 16, 4),
6380                                             Address, Decoder)))
6381         return MCDisassembler::Fail;
6382     }
6383     break;
6384   }
6385   return S;
6386 }
6387 
6388 static DecodeStatus DecodeLongShiftOperand(MCInst &Inst, unsigned Val,
6389                                            uint64_t Address,
6390                                            const MCDisassembler *Decoder) {
6391   DecodeStatus S = MCDisassembler::Success;
6392 
6393   if (Val == 0)
6394     Val = 32;
6395 
6396   Inst.addOperand(MCOperand::createImm(Val));
6397 
6398   return S;
6399 }
6400 
6401 static DecodeStatus DecodetGPROddRegisterClass(MCInst &Inst, unsigned RegNo,
6402                                                uint64_t Address,
6403                                                const MCDisassembler *Decoder) {
6404   if ((RegNo) + 1 > 11)
6405     return MCDisassembler::Fail;
6406 
6407   unsigned Register = GPRDecoderTable[(RegNo) + 1];
6408   Inst.addOperand(MCOperand::createReg(Register));
6409   return MCDisassembler::Success;
6410 }
6411 
6412 static DecodeStatus DecodetGPREvenRegisterClass(MCInst &Inst, unsigned RegNo,
6413                                                 uint64_t Address,
6414                                                 const MCDisassembler *Decoder) {
6415   if ((RegNo) > 14)
6416     return MCDisassembler::Fail;
6417 
6418   unsigned Register = GPRDecoderTable[(RegNo)];
6419   Inst.addOperand(MCOperand::createReg(Register));
6420   return MCDisassembler::Success;
6421 }
6422 
6423 static DecodeStatus
6424 DecodeGPRwithAPSR_NZCVnospRegisterClass(MCInst &Inst, unsigned RegNo,
6425                                         uint64_t Address,
6426                                         const MCDisassembler *Decoder) {
6427   if (RegNo == 15) {
6428     Inst.addOperand(MCOperand::createReg(ARM::APSR_NZCV));
6429     return MCDisassembler::Success;
6430   }
6431 
6432   unsigned Register = GPRDecoderTable[RegNo];
6433   Inst.addOperand(MCOperand::createReg(Register));
6434 
6435   if (RegNo == 13)
6436     return MCDisassembler::SoftFail;
6437 
6438   return MCDisassembler::Success;
6439 }
6440 
6441 static DecodeStatus DecodeVSCCLRM(MCInst &Inst, unsigned Insn, uint64_t Address,
6442                                   const MCDisassembler *Decoder) {
6443   DecodeStatus S = MCDisassembler::Success;
6444 
6445   Inst.addOperand(MCOperand::createImm(ARMCC::AL));
6446   Inst.addOperand(MCOperand::createReg(0));
6447   if (Inst.getOpcode() == ARM::VSCCLRMD) {
6448     unsigned reglist = (fieldFromInstruction(Insn, 1, 7) << 1) |
6449                        (fieldFromInstruction(Insn, 12, 4) << 8) |
6450                        (fieldFromInstruction(Insn, 22, 1) << 12);
6451     if (!Check(S, DecodeDPRRegListOperand(Inst, reglist, Address, Decoder))) {
6452       return MCDisassembler::Fail;
6453     }
6454   } else {
6455     unsigned reglist = fieldFromInstruction(Insn, 0, 8) |
6456                        (fieldFromInstruction(Insn, 22, 1) << 8) |
6457                        (fieldFromInstruction(Insn, 12, 4) << 9);
6458     if (!Check(S, DecodeSPRRegListOperand(Inst, reglist, Address, Decoder))) {
6459       return MCDisassembler::Fail;
6460     }
6461   }
6462   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6463 
6464   return S;
6465 }
6466 
6467 static DecodeStatus DecodeMQPRRegisterClass(MCInst &Inst, unsigned RegNo,
6468                                             uint64_t Address,
6469                                             const MCDisassembler *Decoder) {
6470   if (RegNo > 7)
6471     return MCDisassembler::Fail;
6472 
6473   unsigned Register = QPRDecoderTable[RegNo];
6474   Inst.addOperand(MCOperand::createReg(Register));
6475   return MCDisassembler::Success;
6476 }
6477 
6478 static const uint16_t QQPRDecoderTable[] = {
6479      ARM::Q0_Q1,  ARM::Q1_Q2,  ARM::Q2_Q3,  ARM::Q3_Q4,
6480      ARM::Q4_Q5,  ARM::Q5_Q6,  ARM::Q6_Q7
6481 };
6482 
6483 static DecodeStatus DecodeMQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
6484                                              uint64_t Address,
6485                                              const MCDisassembler *Decoder) {
6486   if (RegNo > 6)
6487     return MCDisassembler::Fail;
6488 
6489   unsigned Register = QQPRDecoderTable[RegNo];
6490   Inst.addOperand(MCOperand::createReg(Register));
6491   return MCDisassembler::Success;
6492 }
6493 
6494 static const uint16_t QQQQPRDecoderTable[] = {
6495      ARM::Q0_Q1_Q2_Q3,  ARM::Q1_Q2_Q3_Q4,  ARM::Q2_Q3_Q4_Q5,
6496      ARM::Q3_Q4_Q5_Q6,  ARM::Q4_Q5_Q6_Q7
6497 };
6498 
6499 static DecodeStatus DecodeMQQQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
6500                                                uint64_t Address,
6501                                                const MCDisassembler *Decoder) {
6502   if (RegNo > 4)
6503     return MCDisassembler::Fail;
6504 
6505   unsigned Register = QQQQPRDecoderTable[RegNo];
6506   Inst.addOperand(MCOperand::createReg(Register));
6507   return MCDisassembler::Success;
6508 }
6509 
6510 static DecodeStatus DecodeVPTMaskOperand(MCInst &Inst, unsigned Val,
6511                                          uint64_t Address,
6512                                          const MCDisassembler *Decoder) {
6513   DecodeStatus S = MCDisassembler::Success;
6514 
6515   // Parse VPT mask and encode it in the MCInst as an immediate with the same
6516   // format as the it_mask.  That is, from the second 'e|t' encode 'e' as 1 and
6517   // 't' as 0 and finish with a 1.
6518   unsigned Imm = 0;
6519   // We always start with a 't'.
6520   unsigned CurBit = 0;
6521   for (int i = 3; i >= 0; --i) {
6522     // If the bit we are looking at is not the same as last one, invert the
6523     // CurBit, if it is the same leave it as is.
6524     CurBit ^= (Val >> i) & 1U;
6525 
6526     // Encode the CurBit at the right place in the immediate.
6527     Imm |= (CurBit << i);
6528 
6529     // If we are done, finish the encoding with a 1.
6530     if ((Val & ~(~0U << i)) == 0) {
6531       Imm |= 1U << i;
6532       break;
6533     }
6534   }
6535 
6536   Inst.addOperand(MCOperand::createImm(Imm));
6537 
6538   return S;
6539 }
6540 
6541 static DecodeStatus DecodeVpredROperand(MCInst &Inst, unsigned RegNo,
6542                                         uint64_t Address,
6543                                         const MCDisassembler *Decoder) {
6544   // The vpred_r operand type includes an MQPR register field derived
6545   // from the encoding. But we don't actually want to add an operand
6546   // to the MCInst at this stage, because AddThumbPredicate will do it
6547   // later, and will infer the register number from the TIED_TO
6548   // constraint. So this is a deliberately empty decoder method that
6549   // will inhibit the auto-generated disassembly code from adding an
6550   // operand at all.
6551   return MCDisassembler::Success;
6552 }
6553 
6554 static DecodeStatus
6555 DecodeRestrictedIPredicateOperand(MCInst &Inst, unsigned Val, uint64_t Address,
6556                                   const MCDisassembler *Decoder) {
6557   Inst.addOperand(MCOperand::createImm((Val & 0x1) == 0 ? ARMCC::EQ : ARMCC::NE));
6558   return MCDisassembler::Success;
6559 }
6560 
6561 static DecodeStatus
6562 DecodeRestrictedSPredicateOperand(MCInst &Inst, unsigned Val, uint64_t Address,
6563                                   const MCDisassembler *Decoder) {
6564   unsigned Code;
6565   switch (Val & 0x3) {
6566   case 0:
6567     Code = ARMCC::GE;
6568     break;
6569   case 1:
6570     Code = ARMCC::LT;
6571     break;
6572   case 2:
6573     Code = ARMCC::GT;
6574     break;
6575   case 3:
6576     Code = ARMCC::LE;
6577     break;
6578   }
6579   Inst.addOperand(MCOperand::createImm(Code));
6580   return MCDisassembler::Success;
6581 }
6582 
6583 static DecodeStatus
6584 DecodeRestrictedUPredicateOperand(MCInst &Inst, unsigned Val, uint64_t Address,
6585                                   const MCDisassembler *Decoder) {
6586   Inst.addOperand(MCOperand::createImm((Val & 0x1) == 0 ? ARMCC::HS : ARMCC::HI));
6587   return MCDisassembler::Success;
6588 }
6589 
6590 static DecodeStatus
6591 DecodeRestrictedFPPredicateOperand(MCInst &Inst, unsigned Val, uint64_t Address,
6592                                    const MCDisassembler *Decoder) {
6593   unsigned Code;
6594   switch (Val) {
6595   default:
6596     return MCDisassembler::Fail;
6597   case 0:
6598     Code = ARMCC::EQ;
6599     break;
6600   case 1:
6601     Code = ARMCC::NE;
6602     break;
6603   case 4:
6604     Code = ARMCC::GE;
6605     break;
6606   case 5:
6607     Code = ARMCC::LT;
6608     break;
6609   case 6:
6610     Code = ARMCC::GT;
6611     break;
6612   case 7:
6613     Code = ARMCC::LE;
6614     break;
6615   }
6616 
6617   Inst.addOperand(MCOperand::createImm(Code));
6618   return MCDisassembler::Success;
6619 }
6620 
6621 static DecodeStatus DecodeVCVTImmOperand(MCInst &Inst, unsigned Val,
6622                                          uint64_t Address,
6623                                          const MCDisassembler *Decoder) {
6624   DecodeStatus S = MCDisassembler::Success;
6625 
6626   unsigned DecodedVal = 64 - Val;
6627 
6628   switch (Inst.getOpcode()) {
6629   case ARM::MVE_VCVTf16s16_fix:
6630   case ARM::MVE_VCVTs16f16_fix:
6631   case ARM::MVE_VCVTf16u16_fix:
6632   case ARM::MVE_VCVTu16f16_fix:
6633     if (DecodedVal > 16)
6634       return MCDisassembler::Fail;
6635     break;
6636   case ARM::MVE_VCVTf32s32_fix:
6637   case ARM::MVE_VCVTs32f32_fix:
6638   case ARM::MVE_VCVTf32u32_fix:
6639   case ARM::MVE_VCVTu32f32_fix:
6640     if (DecodedVal > 32)
6641       return MCDisassembler::Fail;
6642     break;
6643   }
6644 
6645   Inst.addOperand(MCOperand::createImm(64 - Val));
6646 
6647   return S;
6648 }
6649 
6650 static unsigned FixedRegForVSTRVLDR_SYSREG(unsigned Opcode) {
6651   switch (Opcode) {
6652   case ARM::VSTR_P0_off:
6653   case ARM::VSTR_P0_pre:
6654   case ARM::VSTR_P0_post:
6655   case ARM::VLDR_P0_off:
6656   case ARM::VLDR_P0_pre:
6657   case ARM::VLDR_P0_post:
6658     return ARM::P0;
6659   default:
6660     return 0;
6661   }
6662 }
6663 
6664 template <bool Writeback>
6665 static DecodeStatus DecodeVSTRVLDR_SYSREG(MCInst &Inst, unsigned Val,
6666                                           uint64_t Address,
6667                                           const MCDisassembler *Decoder) {
6668   switch (Inst.getOpcode()) {
6669   case ARM::VSTR_FPSCR_pre:
6670   case ARM::VSTR_FPSCR_NZCVQC_pre:
6671   case ARM::VLDR_FPSCR_pre:
6672   case ARM::VLDR_FPSCR_NZCVQC_pre:
6673   case ARM::VSTR_FPSCR_off:
6674   case ARM::VSTR_FPSCR_NZCVQC_off:
6675   case ARM::VLDR_FPSCR_off:
6676   case ARM::VLDR_FPSCR_NZCVQC_off:
6677   case ARM::VSTR_FPSCR_post:
6678   case ARM::VSTR_FPSCR_NZCVQC_post:
6679   case ARM::VLDR_FPSCR_post:
6680   case ARM::VLDR_FPSCR_NZCVQC_post:
6681     const FeatureBitset &featureBits =
6682         ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
6683 
6684     if (!featureBits[ARM::HasMVEIntegerOps] && !featureBits[ARM::FeatureVFP2])
6685       return MCDisassembler::Fail;
6686   }
6687 
6688   DecodeStatus S = MCDisassembler::Success;
6689   if (unsigned Sysreg = FixedRegForVSTRVLDR_SYSREG(Inst.getOpcode()))
6690     Inst.addOperand(MCOperand::createReg(Sysreg));
6691   unsigned Rn = fieldFromInstruction(Val, 16, 4);
6692   unsigned addr = fieldFromInstruction(Val, 0, 7) |
6693                   (fieldFromInstruction(Val, 23, 1) << 7) | (Rn << 8);
6694 
6695   if (Writeback) {
6696     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
6697       return MCDisassembler::Fail;
6698   }
6699   if (!Check(S, DecodeT2AddrModeImm7s4(Inst, addr, Address, Decoder)))
6700     return MCDisassembler::Fail;
6701 
6702   Inst.addOperand(MCOperand::createImm(ARMCC::AL));
6703   Inst.addOperand(MCOperand::createReg(0));
6704 
6705   return S;
6706 }
6707 
6708 static inline DecodeStatus
6709 DecodeMVE_MEM_pre(MCInst &Inst, unsigned Val, uint64_t Address,
6710                   const MCDisassembler *Decoder, unsigned Rn,
6711                   OperandDecoder RnDecoder, OperandDecoder AddrDecoder) {
6712   DecodeStatus S = MCDisassembler::Success;
6713 
6714   unsigned Qd = fieldFromInstruction(Val, 13, 3);
6715   unsigned addr = fieldFromInstruction(Val, 0, 7) |
6716                   (fieldFromInstruction(Val, 23, 1) << 7) | (Rn << 8);
6717 
6718   if (!Check(S, RnDecoder(Inst, Rn, Address, Decoder)))
6719     return MCDisassembler::Fail;
6720   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6721     return MCDisassembler::Fail;
6722   if (!Check(S, AddrDecoder(Inst, addr, Address, Decoder)))
6723     return MCDisassembler::Fail;
6724 
6725   return S;
6726 }
6727 
6728 template <int shift>
6729 static DecodeStatus DecodeMVE_MEM_1_pre(MCInst &Inst, unsigned Val,
6730                                         uint64_t Address,
6731                                         const MCDisassembler *Decoder) {
6732   return DecodeMVE_MEM_pre(Inst, Val, Address, Decoder,
6733                            fieldFromInstruction(Val, 16, 3),
6734                            DecodetGPRRegisterClass,
6735                            DecodeTAddrModeImm7<shift>);
6736 }
6737 
6738 template <int shift>
6739 static DecodeStatus DecodeMVE_MEM_2_pre(MCInst &Inst, unsigned Val,
6740                                         uint64_t Address,
6741                                         const MCDisassembler *Decoder) {
6742   return DecodeMVE_MEM_pre(Inst, Val, Address, Decoder,
6743                            fieldFromInstruction(Val, 16, 4),
6744                            DecoderGPRRegisterClass,
6745                            DecodeT2AddrModeImm7<shift,1>);
6746 }
6747 
6748 template <int shift>
6749 static DecodeStatus DecodeMVE_MEM_3_pre(MCInst &Inst, unsigned Val,
6750                                         uint64_t Address,
6751                                         const MCDisassembler *Decoder) {
6752   return DecodeMVE_MEM_pre(Inst, Val, Address, Decoder,
6753                            fieldFromInstruction(Val, 17, 3),
6754                            DecodeMQPRRegisterClass,
6755                            DecodeMveAddrModeQ<shift>);
6756 }
6757 
6758 template <unsigned MinLog, unsigned MaxLog>
6759 static DecodeStatus DecodePowerTwoOperand(MCInst &Inst, unsigned Val,
6760                                           uint64_t Address,
6761                                           const MCDisassembler *Decoder) {
6762   DecodeStatus S = MCDisassembler::Success;
6763 
6764   if (Val < MinLog || Val > MaxLog)
6765     return MCDisassembler::Fail;
6766 
6767   Inst.addOperand(MCOperand::createImm(1LL << Val));
6768   return S;
6769 }
6770 
6771 template <unsigned start>
6772 static DecodeStatus
6773 DecodeMVEPairVectorIndexOperand(MCInst &Inst, unsigned Val, uint64_t Address,
6774                                 const MCDisassembler *Decoder) {
6775   DecodeStatus S = MCDisassembler::Success;
6776 
6777   Inst.addOperand(MCOperand::createImm(start + Val));
6778 
6779   return S;
6780 }
6781 
6782 static DecodeStatus DecodeMVEVMOVQtoDReg(MCInst &Inst, unsigned Insn,
6783                                          uint64_t Address,
6784                                          const MCDisassembler *Decoder) {
6785   DecodeStatus S = MCDisassembler::Success;
6786   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
6787   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
6788   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
6789                  fieldFromInstruction(Insn, 13, 3));
6790   unsigned index = fieldFromInstruction(Insn, 4, 1);
6791 
6792   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
6793     return MCDisassembler::Fail;
6794   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2, Address, Decoder)))
6795     return MCDisassembler::Fail;
6796   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6797     return MCDisassembler::Fail;
6798   if (!Check(S, DecodeMVEPairVectorIndexOperand<2>(Inst, index, Address, Decoder)))
6799     return MCDisassembler::Fail;
6800   if (!Check(S, DecodeMVEPairVectorIndexOperand<0>(Inst, index, Address, Decoder)))
6801     return MCDisassembler::Fail;
6802 
6803   return S;
6804 }
6805 
6806 static DecodeStatus DecodeMVEVMOVDRegtoQ(MCInst &Inst, unsigned Insn,
6807                                          uint64_t Address,
6808                                          const MCDisassembler *Decoder) {
6809   DecodeStatus S = MCDisassembler::Success;
6810   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
6811   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
6812   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
6813                  fieldFromInstruction(Insn, 13, 3));
6814   unsigned index = fieldFromInstruction(Insn, 4, 1);
6815 
6816   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6817     return MCDisassembler::Fail;
6818   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6819     return MCDisassembler::Fail;
6820   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
6821     return MCDisassembler::Fail;
6822   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2, Address, Decoder)))
6823     return MCDisassembler::Fail;
6824   if (!Check(S, DecodeMVEPairVectorIndexOperand<2>(Inst, index, Address, Decoder)))
6825     return MCDisassembler::Fail;
6826   if (!Check(S, DecodeMVEPairVectorIndexOperand<0>(Inst, index, Address, Decoder)))
6827     return MCDisassembler::Fail;
6828 
6829   return S;
6830 }
6831 
6832 static DecodeStatus
6833 DecodeMVEOverlappingLongShift(MCInst &Inst, unsigned Insn, uint64_t Address,
6834                               const MCDisassembler *Decoder) {
6835   DecodeStatus S = MCDisassembler::Success;
6836 
6837   unsigned RdaLo = fieldFromInstruction(Insn, 17, 3) << 1;
6838   unsigned RdaHi = fieldFromInstruction(Insn, 9, 3) << 1;
6839   unsigned Rm = fieldFromInstruction(Insn, 12, 4);
6840 
6841   if (RdaHi == 14) {
6842     // This value of RdaHi (really indicating pc, because RdaHi has to
6843     // be an odd-numbered register, so the low bit will be set by the
6844     // decode function below) indicates that we must decode as SQRSHR
6845     // or UQRSHL, which both have a single Rda register field with all
6846     // four bits.
6847     unsigned Rda = fieldFromInstruction(Insn, 16, 4);
6848 
6849     switch (Inst.getOpcode()) {
6850       case ARM::MVE_ASRLr:
6851       case ARM::MVE_SQRSHRL:
6852         Inst.setOpcode(ARM::MVE_SQRSHR);
6853         break;
6854       case ARM::MVE_LSLLr:
6855       case ARM::MVE_UQRSHLL:
6856         Inst.setOpcode(ARM::MVE_UQRSHL);
6857         break;
6858       default:
6859         llvm_unreachable("Unexpected starting opcode!");
6860     }
6861 
6862     // Rda as output parameter
6863     if (!Check(S, DecoderGPRRegisterClass(Inst, Rda, Address, Decoder)))
6864       return MCDisassembler::Fail;
6865 
6866     // Rda again as input parameter
6867     if (!Check(S, DecoderGPRRegisterClass(Inst, Rda, Address, Decoder)))
6868       return MCDisassembler::Fail;
6869 
6870     // Rm, the amount to shift by
6871     if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
6872       return MCDisassembler::Fail;
6873 
6874     if (fieldFromInstruction (Insn, 6, 3) != 4)
6875       return MCDisassembler::SoftFail;
6876 
6877     if (Rda == Rm)
6878       return MCDisassembler::SoftFail;
6879 
6880     return S;
6881   }
6882 
6883   // Otherwise, we decode as whichever opcode our caller has already
6884   // put into Inst. Those all look the same:
6885 
6886   // RdaLo,RdaHi as output parameters
6887   if (!Check(S, DecodetGPREvenRegisterClass(Inst, RdaLo, Address, Decoder)))
6888     return MCDisassembler::Fail;
6889   if (!Check(S, DecodetGPROddRegisterClass(Inst, RdaHi, Address, Decoder)))
6890     return MCDisassembler::Fail;
6891 
6892   // RdaLo,RdaHi again as input parameters
6893   if (!Check(S, DecodetGPREvenRegisterClass(Inst, RdaLo, Address, Decoder)))
6894     return MCDisassembler::Fail;
6895   if (!Check(S, DecodetGPROddRegisterClass(Inst, RdaHi, Address, Decoder)))
6896     return MCDisassembler::Fail;
6897 
6898   // Rm, the amount to shift by
6899   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
6900     return MCDisassembler::Fail;
6901 
6902   if (Inst.getOpcode() == ARM::MVE_SQRSHRL ||
6903       Inst.getOpcode() == ARM::MVE_UQRSHLL) {
6904     unsigned Saturate = fieldFromInstruction(Insn, 7, 1);
6905     // Saturate, the bit position for saturation
6906     Inst.addOperand(MCOperand::createImm(Saturate));
6907   }
6908 
6909   return S;
6910 }
6911 
6912 static DecodeStatus DecodeMVEVCVTt1fp(MCInst &Inst, unsigned Insn,
6913                                       uint64_t Address,
6914                                       const MCDisassembler *Decoder) {
6915   DecodeStatus S = MCDisassembler::Success;
6916   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
6917                  fieldFromInstruction(Insn, 13, 3));
6918   unsigned Qm = ((fieldFromInstruction(Insn, 5, 1) << 3) |
6919                  fieldFromInstruction(Insn, 1, 3));
6920   unsigned imm6 = fieldFromInstruction(Insn, 16, 6);
6921 
6922   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6923     return MCDisassembler::Fail;
6924   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
6925     return MCDisassembler::Fail;
6926   if (!Check(S, DecodeVCVTImmOperand(Inst, imm6, Address, Decoder)))
6927     return MCDisassembler::Fail;
6928 
6929   return S;
6930 }
6931 
6932 template <bool scalar, OperandDecoder predicate_decoder>
6933 static DecodeStatus DecodeMVEVCMP(MCInst &Inst, unsigned Insn, uint64_t Address,
6934                                   const MCDisassembler *Decoder) {
6935   DecodeStatus S = MCDisassembler::Success;
6936   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6937   unsigned Qn = fieldFromInstruction(Insn, 17, 3);
6938   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qn, Address, Decoder)))
6939     return MCDisassembler::Fail;
6940 
6941   unsigned fc;
6942 
6943   if (scalar) {
6944     fc = fieldFromInstruction(Insn, 12, 1) << 2 |
6945          fieldFromInstruction(Insn, 7, 1) |
6946          fieldFromInstruction(Insn, 5, 1) << 1;
6947     unsigned Rm = fieldFromInstruction(Insn, 0, 4);
6948     if (!Check(S, DecodeGPRwithZRRegisterClass(Inst, Rm, Address, Decoder)))
6949       return MCDisassembler::Fail;
6950   } else {
6951     fc = fieldFromInstruction(Insn, 12, 1) << 2 |
6952          fieldFromInstruction(Insn, 7, 1) |
6953          fieldFromInstruction(Insn, 0, 1) << 1;
6954     unsigned Qm = fieldFromInstruction(Insn, 5, 1) << 4 |
6955                   fieldFromInstruction(Insn, 1, 3);
6956     if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
6957       return MCDisassembler::Fail;
6958   }
6959 
6960   if (!Check(S, predicate_decoder(Inst, fc, Address, Decoder)))
6961     return MCDisassembler::Fail;
6962 
6963   Inst.addOperand(MCOperand::createImm(ARMVCC::None));
6964   Inst.addOperand(MCOperand::createReg(0));
6965   Inst.addOperand(MCOperand::createImm(0));
6966 
6967   return S;
6968 }
6969 
6970 static DecodeStatus DecodeMveVCTP(MCInst &Inst, unsigned Insn, uint64_t Address,
6971                                   const MCDisassembler *Decoder) {
6972   DecodeStatus S = MCDisassembler::Success;
6973   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6974   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
6975   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
6976     return MCDisassembler::Fail;
6977   return S;
6978 }
6979 
6980 static DecodeStatus DecodeMVEVPNOT(MCInst &Inst, unsigned Insn,
6981                                    uint64_t Address,
6982                                    const MCDisassembler *Decoder) {
6983   DecodeStatus S = MCDisassembler::Success;
6984   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6985   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6986   return S;
6987 }
6988 
6989 static DecodeStatus DecodeT2AddSubSPImm(MCInst &Inst, unsigned Insn,
6990                                         uint64_t Address,
6991                                         const MCDisassembler *Decoder) {
6992   const unsigned Rd = fieldFromInstruction(Insn, 8, 4);
6993   const unsigned Rn = fieldFromInstruction(Insn, 16, 4);
6994   const unsigned Imm12 = fieldFromInstruction(Insn, 26, 1) << 11 |
6995                          fieldFromInstruction(Insn, 12, 3) << 8 |
6996                          fieldFromInstruction(Insn, 0, 8);
6997   const unsigned TypeT3 = fieldFromInstruction(Insn, 25, 1);
6998   unsigned sign1 = fieldFromInstruction(Insn, 21, 1);
6999   unsigned sign2 = fieldFromInstruction(Insn, 23, 1);
7000   unsigned S = fieldFromInstruction(Insn, 20, 1);
7001   if (sign1 != sign2)
7002     return MCDisassembler::Fail;
7003 
7004   // T3 does a zext of imm12, where T2 does a ThumbExpandImm (T2SOImm)
7005   DecodeStatus DS = MCDisassembler::Success;
7006   if ((!Check(DS,
7007               DecodeGPRspRegisterClass(Inst, Rd, Address, Decoder))) || // dst
7008       (!Check(DS, DecodeGPRspRegisterClass(Inst, Rn, Address, Decoder))))
7009     return MCDisassembler::Fail;
7010   if (TypeT3) {
7011     Inst.setOpcode(sign1 ? ARM::t2SUBspImm12 : ARM::t2ADDspImm12);
7012     Inst.addOperand(MCOperand::createImm(Imm12)); // zext imm12
7013   } else {
7014     Inst.setOpcode(sign1 ? ARM::t2SUBspImm : ARM::t2ADDspImm);
7015     if (!Check(DS, DecodeT2SOImm(Inst, Imm12, Address, Decoder))) // imm12
7016       return MCDisassembler::Fail;
7017     if (!Check(DS, DecodeCCOutOperand(Inst, S, Address, Decoder))) // cc_out
7018       return MCDisassembler::Fail;
7019   }
7020 
7021   return DS;
7022 }
7023