xref: /llvm-project/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp (revision 372240dfe3d5a933d9585663e15c4b6173ff23c8)
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     InstructionEndianness = STI.getFeatureBits()[ARM::ModeBigEndianInstructions]
135                                 ? llvm::support::big
136                                 : llvm::support::little;
137   }
138 
139   ~ARMDisassembler() override = default;
140 
141   DecodeStatus getInstruction(MCInst &Instr, uint64_t &Size,
142                               ArrayRef<uint8_t> Bytes, uint64_t Address,
143                               raw_ostream &CStream) const override;
144 
145   uint64_t suggestBytesToSkip(ArrayRef<uint8_t> Bytes,
146                               uint64_t Address) const override;
147 
148 private:
149   DecodeStatus getARMInstruction(MCInst &Instr, uint64_t &Size,
150                                  ArrayRef<uint8_t> Bytes, uint64_t Address,
151                                  raw_ostream &CStream) const;
152 
153   DecodeStatus getThumbInstruction(MCInst &Instr, uint64_t &Size,
154                                    ArrayRef<uint8_t> Bytes, uint64_t Address,
155                                    raw_ostream &CStream) const;
156 
157   mutable ITStatus ITBlock;
158   mutable VPTStatus VPTBlock;
159 
160   DecodeStatus AddThumbPredicate(MCInst&) const;
161   void UpdateThumbVFPPredicate(DecodeStatus &, MCInst&) const;
162 
163   llvm::support::endianness InstructionEndianness;
164 };
165 
166 } // end anonymous namespace
167 
168 // Forward declare these because the autogenerated code will reference them.
169 // Definitions are further down.
170 static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, unsigned RegNo,
171                                            uint64_t Address,
172                                            const MCDisassembler *Decoder);
173 static DecodeStatus DecodeCLRMGPRRegisterClass(MCInst &Inst, unsigned RegNo,
174                                                uint64_t Address,
175                                                const MCDisassembler *Decoder);
176 static DecodeStatus DecodetGPROddRegisterClass(MCInst &Inst, unsigned RegNo,
177                                                uint64_t Address,
178                                                const MCDisassembler *Decoder);
179 static DecodeStatus DecodetGPREvenRegisterClass(MCInst &Inst, unsigned RegNo,
180                                                 uint64_t Address,
181                                                 const MCDisassembler *Decoder);
182 static DecodeStatus
183 DecodeGPRwithAPSR_NZCVnospRegisterClass(MCInst &Inst, unsigned RegNo,
184                                         uint64_t Address,
185                                         const MCDisassembler *Decoder);
186 static DecodeStatus DecodeGPRnopcRegisterClass(MCInst &Inst, unsigned RegNo,
187                                                uint64_t Address,
188                                                const MCDisassembler *Decoder);
189 static DecodeStatus DecodeGPRnospRegisterClass(MCInst &Inst, unsigned RegNo,
190                                                uint64_t Address,
191                                                const MCDisassembler *Decoder);
192 static DecodeStatus
193 DecodeGPRwithAPSRRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Address,
194                                const MCDisassembler *Decoder);
195 static DecodeStatus DecodeGPRwithZRRegisterClass(MCInst &Inst, unsigned RegNo,
196                                                  uint64_t Address,
197                                                  const MCDisassembler *Decoder);
198 static DecodeStatus
199 DecodeGPRwithZRnospRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Address,
200                                  const MCDisassembler *Decoder);
201 static DecodeStatus DecodetGPRRegisterClass(MCInst &Inst, unsigned RegNo,
202                                             uint64_t Address,
203                                             const MCDisassembler *Decoder);
204 static DecodeStatus DecodetcGPRRegisterClass(MCInst &Inst, unsigned RegNo,
205                                              uint64_t Address,
206                                              const MCDisassembler *Decoder);
207 static DecodeStatus DecoderGPRRegisterClass(MCInst &Inst, unsigned RegNo,
208                                             uint64_t Address,
209                                             const MCDisassembler *Decoder);
210 static DecodeStatus DecodeGPRPairRegisterClass(MCInst &Inst, unsigned RegNo,
211                                                uint64_t Address,
212                                                const MCDisassembler *Decoder);
213 static DecodeStatus
214 DecodeGPRPairnospRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Address,
215                                const MCDisassembler *Decoder);
216 static DecodeStatus DecodeGPRspRegisterClass(MCInst &Inst, unsigned RegNo,
217                                              uint64_t Address,
218                                              const MCDisassembler *Decoder);
219 static DecodeStatus DecodeHPRRegisterClass(MCInst &Inst, unsigned RegNo,
220                                            uint64_t Address,
221                                            const MCDisassembler *Decoder);
222 static DecodeStatus DecodeSPRRegisterClass(MCInst &Inst, unsigned RegNo,
223                                            uint64_t Address,
224                                            const MCDisassembler *Decoder);
225 static DecodeStatus DecodeDPRRegisterClass(MCInst &Inst, unsigned RegNo,
226                                            uint64_t Address,
227                                            const MCDisassembler *Decoder);
228 static DecodeStatus DecodeDPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
229                                              uint64_t Address,
230                                              const MCDisassembler *Decoder);
231 static DecodeStatus DecodeSPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
232                                              uint64_t Address,
233                                              const MCDisassembler *Decoder);
234 static DecodeStatus DecodeDPR_VFP2RegisterClass(MCInst &Inst, unsigned RegNo,
235                                                 uint64_t Address,
236                                                 const MCDisassembler *Decoder);
237 static DecodeStatus DecodeQPRRegisterClass(MCInst &Inst, unsigned RegNo,
238                                            uint64_t Address,
239                                            const MCDisassembler *Decoder);
240 static DecodeStatus DecodeMQPRRegisterClass(MCInst &Inst, unsigned RegNo,
241                                             uint64_t Address,
242                                             const MCDisassembler *Decoder);
243 static DecodeStatus DecodeMQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
244                                              uint64_t Address,
245                                              const MCDisassembler *Decoder);
246 static DecodeStatus DecodeMQQQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
247                                                uint64_t Address,
248                                                const MCDisassembler *Decoder);
249 static DecodeStatus DecodeDPairRegisterClass(MCInst &Inst, unsigned RegNo,
250                                              uint64_t Address,
251                                              const MCDisassembler *Decoder);
252 static DecodeStatus
253 DecodeDPairSpacedRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Address,
254                                const MCDisassembler *Decoder);
255 
256 static DecodeStatus DecodePredicateOperand(MCInst &Inst, unsigned Val,
257                                            uint64_t Address,
258                                            const MCDisassembler *Decoder);
259 static DecodeStatus DecodeCCOutOperand(MCInst &Inst, unsigned Val,
260                                        uint64_t Address,
261                                        const MCDisassembler *Decoder);
262 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Val,
263                                          uint64_t Address,
264                                          const MCDisassembler *Decoder);
265 static DecodeStatus DecodeSPRRegListOperand(MCInst &Inst, unsigned Val,
266                                             uint64_t Address,
267                                             const MCDisassembler *Decoder);
268 static DecodeStatus DecodeDPRRegListOperand(MCInst &Inst, unsigned Val,
269                                             uint64_t Address,
270                                             const MCDisassembler *Decoder);
271 
272 static DecodeStatus DecodeBitfieldMaskOperand(MCInst &Inst, unsigned Insn,
273                                               uint64_t Address,
274                                               const MCDisassembler *Decoder);
275 static DecodeStatus DecodeCopMemInstruction(MCInst &Inst, unsigned Insn,
276                                             uint64_t Address,
277                                             const MCDisassembler *Decoder);
278 static DecodeStatus
279 DecodeAddrMode2IdxInstruction(MCInst &Inst, unsigned Insn, uint64_t Address,
280                               const MCDisassembler *Decoder);
281 static DecodeStatus DecodeSORegMemOperand(MCInst &Inst, unsigned Insn,
282                                           uint64_t Address,
283                                           const MCDisassembler *Decoder);
284 static DecodeStatus DecodeAddrMode3Instruction(MCInst &Inst, unsigned Insn,
285                                                uint64_t Address,
286                                                const MCDisassembler *Decoder);
287 static DecodeStatus DecodeTSBInstruction(MCInst &Inst, unsigned Insn,
288                                          uint64_t Address,
289                                          const MCDisassembler *Decoder);
290 static DecodeStatus DecodeSORegImmOperand(MCInst &Inst, unsigned Insn,
291                                           uint64_t Address,
292                                           const MCDisassembler *Decoder);
293 static DecodeStatus DecodeSORegRegOperand(MCInst &Inst, unsigned Insn,
294                                           uint64_t Address,
295                                           const MCDisassembler *Decoder);
296 
297 static DecodeStatus
298 DecodeMemMultipleWritebackInstruction(MCInst &Inst, unsigned Insn,
299                                       uint64_t Adddress,
300                                       const MCDisassembler *Decoder);
301 static DecodeStatus DecodeT2MOVTWInstruction(MCInst &Inst, unsigned Insn,
302                                              uint64_t Address,
303                                              const MCDisassembler *Decoder);
304 static DecodeStatus DecodeArmMOVTWInstruction(MCInst &Inst, unsigned Insn,
305                                               uint64_t Address,
306                                               const MCDisassembler *Decoder);
307 static DecodeStatus DecodeSMLAInstruction(MCInst &Inst, unsigned Insn,
308                                           uint64_t Address,
309                                           const MCDisassembler *Decoder);
310 static DecodeStatus DecodeHINTInstruction(MCInst &Inst, unsigned Insn,
311                                           uint64_t Address,
312                                           const MCDisassembler *Decoder);
313 static DecodeStatus DecodeCPSInstruction(MCInst &Inst, unsigned Insn,
314                                          uint64_t Address,
315                                          const MCDisassembler *Decoder);
316 static DecodeStatus DecodeTSTInstruction(MCInst &Inst, unsigned Insn,
317                                          uint64_t Address,
318                                          const MCDisassembler *Decoder);
319 static DecodeStatus DecodeSETPANInstruction(MCInst &Inst, unsigned Insn,
320                                             uint64_t Address,
321                                             const MCDisassembler *Decoder);
322 static DecodeStatus DecodeT2CPSInstruction(MCInst &Inst, unsigned Insn,
323                                            uint64_t Address,
324                                            const MCDisassembler *Decoder);
325 static DecodeStatus DecodeT2HintSpaceInstruction(MCInst &Inst, unsigned Insn,
326                                                  uint64_t Address,
327                                                  const MCDisassembler *Decoder);
328 static DecodeStatus DecodeAddrModeImm12Operand(MCInst &Inst, unsigned Val,
329                                                uint64_t Address,
330                                                const MCDisassembler *Decoder);
331 static DecodeStatus DecodeAddrMode5Operand(MCInst &Inst, unsigned Val,
332                                            uint64_t Address,
333                                            const MCDisassembler *Decoder);
334 static DecodeStatus DecodeAddrMode5FP16Operand(MCInst &Inst, unsigned Val,
335                                                uint64_t Address,
336                                                const MCDisassembler *Decoder);
337 static DecodeStatus DecodeAddrMode7Operand(MCInst &Inst, unsigned Val,
338                                            uint64_t Address,
339                                            const MCDisassembler *Decoder);
340 static DecodeStatus DecodeT2BInstruction(MCInst &Inst, unsigned Insn,
341                                          uint64_t Address,
342                                          const MCDisassembler *Decoder);
343 static DecodeStatus DecodeBranchImmInstruction(MCInst &Inst, unsigned Insn,
344                                                uint64_t Address,
345                                                const MCDisassembler *Decoder);
346 static DecodeStatus DecodeAddrMode6Operand(MCInst &Inst, unsigned Val,
347                                            uint64_t Address,
348                                            const MCDisassembler *Decoder);
349 static DecodeStatus DecodeVLDST1Instruction(MCInst &Inst, unsigned Val,
350                                             uint64_t Address,
351                                             const MCDisassembler *Decoder);
352 static DecodeStatus DecodeVLDST2Instruction(MCInst &Inst, unsigned Val,
353                                             uint64_t Address,
354                                             const MCDisassembler *Decoder);
355 static DecodeStatus DecodeVLDST3Instruction(MCInst &Inst, unsigned Val,
356                                             uint64_t Address,
357                                             const MCDisassembler *Decoder);
358 static DecodeStatus DecodeVLDST4Instruction(MCInst &Inst, unsigned Val,
359                                             uint64_t Address,
360                                             const MCDisassembler *Decoder);
361 static DecodeStatus DecodeVLDInstruction(MCInst &Inst, unsigned Val,
362                                          uint64_t Address,
363                                          const MCDisassembler *Decoder);
364 static DecodeStatus DecodeVSTInstruction(MCInst &Inst, unsigned Val,
365                                          uint64_t Address,
366                                          const MCDisassembler *Decoder);
367 static DecodeStatus DecodeVLD1DupInstruction(MCInst &Inst, unsigned Val,
368                                              uint64_t Address,
369                                              const MCDisassembler *Decoder);
370 static DecodeStatus DecodeVLD2DupInstruction(MCInst &Inst, unsigned Val,
371                                              uint64_t Address,
372                                              const MCDisassembler *Decoder);
373 static DecodeStatus DecodeVLD3DupInstruction(MCInst &Inst, unsigned Val,
374                                              uint64_t Address,
375                                              const MCDisassembler *Decoder);
376 static DecodeStatus DecodeVLD4DupInstruction(MCInst &Inst, unsigned Val,
377                                              uint64_t Address,
378                                              const MCDisassembler *Decoder);
379 static DecodeStatus DecodeVMOVModImmInstruction(MCInst &Inst, unsigned Val,
380                                                 uint64_t Address,
381                                                 const MCDisassembler *Decoder);
382 static DecodeStatus DecodeMVEModImmInstruction(MCInst &Inst, unsigned Val,
383                                                uint64_t Address,
384                                                const MCDisassembler *Decoder);
385 static DecodeStatus DecodeMVEVADCInstruction(MCInst &Inst, unsigned Insn,
386                                              uint64_t Address,
387                                              const MCDisassembler *Decoder);
388 static DecodeStatus DecodeVSHLMaxInstruction(MCInst &Inst, unsigned Val,
389                                              uint64_t Address,
390                                              const MCDisassembler *Decoder);
391 static DecodeStatus DecodeShiftRight8Imm(MCInst &Inst, unsigned Val,
392                                          uint64_t Address,
393                                          const MCDisassembler *Decoder);
394 static DecodeStatus DecodeShiftRight16Imm(MCInst &Inst, unsigned Val,
395                                           uint64_t Address,
396                                           const MCDisassembler *Decoder);
397 static DecodeStatus DecodeShiftRight32Imm(MCInst &Inst, unsigned Val,
398                                           uint64_t Address,
399                                           const MCDisassembler *Decoder);
400 static DecodeStatus DecodeShiftRight64Imm(MCInst &Inst, unsigned Val,
401                                           uint64_t Address,
402                                           const MCDisassembler *Decoder);
403 static DecodeStatus DecodeTBLInstruction(MCInst &Inst, unsigned Insn,
404                                          uint64_t Address,
405                                          const MCDisassembler *Decoder);
406 static DecodeStatus DecodePostIdxReg(MCInst &Inst, unsigned Insn,
407                                      uint64_t Address,
408                                      const MCDisassembler *Decoder);
409 static DecodeStatus DecodeMveAddrModeRQ(MCInst &Inst, unsigned Insn,
410                                         uint64_t Address,
411                                         const MCDisassembler *Decoder);
412 template <int shift>
413 static DecodeStatus DecodeMveAddrModeQ(MCInst &Inst, unsigned Insn,
414                                        uint64_t Address,
415                                        const MCDisassembler *Decoder);
416 static DecodeStatus DecodeCoprocessor(MCInst &Inst, unsigned Insn,
417                                       uint64_t Address,
418                                       const MCDisassembler *Decoder);
419 static DecodeStatus DecodeMemBarrierOption(MCInst &Inst, unsigned Insn,
420                                            uint64_t Address,
421                                            const MCDisassembler *Decoder);
422 static DecodeStatus DecodeInstSyncBarrierOption(MCInst &Inst, unsigned Insn,
423                                                 uint64_t Address,
424                                                 const MCDisassembler *Decoder);
425 static DecodeStatus DecodeMSRMask(MCInst &Inst, unsigned Insn, uint64_t Address,
426                                   const MCDisassembler *Decoder);
427 static DecodeStatus DecodeBankedReg(MCInst &Inst, unsigned Insn,
428                                     uint64_t Address,
429                                     const MCDisassembler *Decoder);
430 static DecodeStatus DecodeDoubleRegLoad(MCInst &Inst, unsigned Insn,
431                                         uint64_t Address,
432                                         const MCDisassembler *Decoder);
433 static DecodeStatus DecodeDoubleRegStore(MCInst &Inst, unsigned Insn,
434                                          uint64_t Address,
435                                          const MCDisassembler *Decoder);
436 static DecodeStatus DecodeLDRPreImm(MCInst &Inst, unsigned Insn,
437                                     uint64_t Address,
438                                     const MCDisassembler *Decoder);
439 static DecodeStatus DecodeLDRPreReg(MCInst &Inst, unsigned Insn,
440                                     uint64_t Address,
441                                     const MCDisassembler *Decoder);
442 static DecodeStatus DecodeSTRPreImm(MCInst &Inst, unsigned Insn,
443                                     uint64_t Address,
444                                     const MCDisassembler *Decoder);
445 static DecodeStatus DecodeSTRPreReg(MCInst &Inst, unsigned Insn,
446                                     uint64_t Address,
447                                     const MCDisassembler *Decoder);
448 static DecodeStatus DecodeVLD1LN(MCInst &Inst, unsigned Insn, uint64_t Address,
449                                  const MCDisassembler *Decoder);
450 static DecodeStatus DecodeVLD2LN(MCInst &Inst, unsigned Insn, uint64_t Address,
451                                  const MCDisassembler *Decoder);
452 static DecodeStatus DecodeVLD3LN(MCInst &Inst, unsigned Insn, uint64_t Address,
453                                  const MCDisassembler *Decoder);
454 static DecodeStatus DecodeVLD4LN(MCInst &Inst, unsigned Insn, uint64_t Address,
455                                  const MCDisassembler *Decoder);
456 static DecodeStatus DecodeVST1LN(MCInst &Inst, unsigned Insn, uint64_t Address,
457                                  const MCDisassembler *Decoder);
458 static DecodeStatus DecodeVST2LN(MCInst &Inst, unsigned Insn, uint64_t Address,
459                                  const MCDisassembler *Decoder);
460 static DecodeStatus DecodeVST3LN(MCInst &Inst, unsigned Insn, uint64_t Address,
461                                  const MCDisassembler *Decoder);
462 static DecodeStatus DecodeVST4LN(MCInst &Inst, unsigned Insn, uint64_t Address,
463                                  const MCDisassembler *Decoder);
464 static DecodeStatus DecodeVMOVSRR(MCInst &Inst, unsigned Insn, uint64_t Address,
465                                   const MCDisassembler *Decoder);
466 static DecodeStatus DecodeVMOVRRS(MCInst &Inst, unsigned Insn, uint64_t Address,
467                                   const MCDisassembler *Decoder);
468 static DecodeStatus DecodeSwap(MCInst &Inst, unsigned Insn, uint64_t Address,
469                                const MCDisassembler *Decoder);
470 static DecodeStatus DecodeVCVTD(MCInst &Inst, unsigned Insn, uint64_t Address,
471                                 const MCDisassembler *Decoder);
472 static DecodeStatus DecodeVCVTQ(MCInst &Inst, unsigned Insn, uint64_t Address,
473                                 const MCDisassembler *Decoder);
474 static DecodeStatus DecodeVCVTImmOperand(MCInst &Inst, unsigned Insn,
475                                          uint64_t Address,
476                                          const MCDisassembler *Decoder);
477 static DecodeStatus
478 DecodeNEONComplexLane64Instruction(MCInst &Inst, unsigned Val, uint64_t Address,
479                                    const MCDisassembler *Decoder);
480 
481 static DecodeStatus DecodeThumbAddSpecialReg(MCInst &Inst, uint16_t Insn,
482                                              uint64_t Address,
483                                              const MCDisassembler *Decoder);
484 static DecodeStatus DecodeThumbBROperand(MCInst &Inst, unsigned Val,
485                                          uint64_t Address,
486                                          const MCDisassembler *Decoder);
487 static DecodeStatus DecodeT2BROperand(MCInst &Inst, unsigned Val,
488                                       uint64_t Address,
489                                       const MCDisassembler *Decoder);
490 static DecodeStatus DecodeThumbCmpBROperand(MCInst &Inst, unsigned Val,
491                                             uint64_t Address,
492                                             const MCDisassembler *Decoder);
493 static DecodeStatus DecodeThumbAddrModeRR(MCInst &Inst, unsigned Val,
494                                           uint64_t Address,
495                                           const MCDisassembler *Decoder);
496 static DecodeStatus DecodeThumbAddrModeIS(MCInst &Inst, unsigned Val,
497                                           uint64_t Address,
498                                           const MCDisassembler *Decoder);
499 static DecodeStatus DecodeThumbAddrModePC(MCInst &Inst, unsigned Val,
500                                           uint64_t Address,
501                                           const MCDisassembler *Decoder);
502 static DecodeStatus DecodeThumbAddrModeSP(MCInst &Inst, unsigned Val,
503                                           uint64_t Address,
504                                           const MCDisassembler *Decoder);
505 static DecodeStatus DecodeT2AddrModeSOReg(MCInst &Inst, unsigned Val,
506                                           uint64_t Address,
507                                           const MCDisassembler *Decoder);
508 static DecodeStatus DecodeT2LoadShift(MCInst &Inst, unsigned Val,
509                                       uint64_t Address,
510                                       const MCDisassembler *Decoder);
511 static DecodeStatus DecodeT2LoadImm8(MCInst &Inst, unsigned Insn,
512                                      uint64_t Address,
513                                      const MCDisassembler *Decoder);
514 static DecodeStatus DecodeT2LoadImm12(MCInst &Inst, unsigned Insn,
515                                       uint64_t Address,
516                                       const MCDisassembler *Decoder);
517 static DecodeStatus DecodeT2LoadT(MCInst &Inst, unsigned Insn, uint64_t Address,
518                                   const MCDisassembler *Decoder);
519 static DecodeStatus DecodeT2LoadLabel(MCInst &Inst, unsigned Insn,
520                                       uint64_t Address,
521                                       const MCDisassembler *Decoder);
522 static DecodeStatus DecodeT2Imm8S4(MCInst &Inst, unsigned Val, uint64_t Address,
523                                    const MCDisassembler *Decoder);
524 static DecodeStatus DecodeT2Imm7S4(MCInst &Inst, unsigned Val, uint64_t Address,
525                                    const MCDisassembler *Decoder);
526 static DecodeStatus DecodeT2AddrModeImm8s4(MCInst &Inst, unsigned Val,
527                                            uint64_t Address,
528                                            const MCDisassembler *Decoder);
529 static DecodeStatus DecodeT2AddrModeImm7s4(MCInst &Inst, unsigned Val,
530                                            uint64_t Address,
531                                            const MCDisassembler *Decoder);
532 static DecodeStatus DecodeT2AddrModeImm0_1020s4(MCInst &Inst, unsigned Val,
533                                                 uint64_t Address,
534                                                 const MCDisassembler *Decoder);
535 static DecodeStatus DecodeT2Imm8(MCInst &Inst, unsigned Val, uint64_t Address,
536                                  const MCDisassembler *Decoder);
537 template <int shift>
538 static DecodeStatus DecodeT2Imm7(MCInst &Inst, unsigned Val, uint64_t Address,
539                                  const MCDisassembler *Decoder);
540 static DecodeStatus DecodeT2AddrModeImm8(MCInst &Inst, unsigned Val,
541                                          uint64_t Address,
542                                          const MCDisassembler *Decoder);
543 template <int shift>
544 static DecodeStatus DecodeTAddrModeImm7(MCInst &Inst, unsigned Val,
545                                         uint64_t Address,
546                                         const MCDisassembler *Decoder);
547 template <int shift, int WriteBack>
548 static DecodeStatus DecodeT2AddrModeImm7(MCInst &Inst, unsigned Val,
549                                          uint64_t Address,
550                                          const MCDisassembler *Decoder);
551 static DecodeStatus DecodeThumbAddSPImm(MCInst &Inst, uint16_t Val,
552                                         uint64_t Address,
553                                         const MCDisassembler *Decoder);
554 static DecodeStatus DecodeThumbAddSPReg(MCInst &Inst, uint16_t Insn,
555                                         uint64_t Address,
556                                         const MCDisassembler *Decoder);
557 static DecodeStatus DecodeThumbCPS(MCInst &Inst, uint16_t Insn,
558                                    uint64_t Address,
559                                    const MCDisassembler *Decoder);
560 static DecodeStatus DecodeQADDInstruction(MCInst &Inst, unsigned Insn,
561                                           uint64_t Address,
562                                           const MCDisassembler *Decoder);
563 static DecodeStatus DecodeThumbBLXOffset(MCInst &Inst, unsigned Insn,
564                                          uint64_t Address,
565                                          const MCDisassembler *Decoder);
566 static DecodeStatus DecodeT2AddrModeImm12(MCInst &Inst, unsigned Val,
567                                           uint64_t Address,
568                                           const MCDisassembler *Decoder);
569 static DecodeStatus DecodeThumbTableBranch(MCInst &Inst, unsigned Val,
570                                            uint64_t Address,
571                                            const MCDisassembler *Decoder);
572 static DecodeStatus DecodeThumb2BCCInstruction(MCInst &Inst, unsigned Val,
573                                                uint64_t Address,
574                                                const MCDisassembler *Decoder);
575 static DecodeStatus DecodeT2SOImm(MCInst &Inst, unsigned Val, uint64_t Address,
576                                   const MCDisassembler *Decoder);
577 static DecodeStatus DecodeThumbBCCTargetOperand(MCInst &Inst, unsigned Val,
578                                                 uint64_t Address,
579                                                 const MCDisassembler *Decoder);
580 static DecodeStatus DecodeThumbBLTargetOperand(MCInst &Inst, unsigned Val,
581                                                uint64_t Address,
582                                                const MCDisassembler *Decoder);
583 static DecodeStatus DecodeIT(MCInst &Inst, unsigned Val, uint64_t Address,
584                              const MCDisassembler *Decoder);
585 static DecodeStatus DecodeT2LDRDPreInstruction(MCInst &Inst, unsigned Insn,
586                                                uint64_t Address,
587                                                const MCDisassembler *Decoder);
588 static DecodeStatus DecodeT2STRDPreInstruction(MCInst &Inst, unsigned Insn,
589                                                uint64_t Address,
590                                                const MCDisassembler *Decoder);
591 static DecodeStatus DecodeT2Adr(MCInst &Inst, unsigned Val, uint64_t Address,
592                                 const MCDisassembler *Decoder);
593 static DecodeStatus DecodeT2LdStPre(MCInst &Inst, unsigned Val,
594                                     uint64_t Address,
595                                     const MCDisassembler *Decoder);
596 static DecodeStatus DecodeT2ShifterImmOperand(MCInst &Inst, unsigned Val,
597                                               uint64_t Address,
598                                               const MCDisassembler *Decoder);
599 
600 static DecodeStatus DecodeLDR(MCInst &Inst, unsigned Val, uint64_t Address,
601                               const MCDisassembler *Decoder);
602 static DecodeStatus DecoderForMRRC2AndMCRR2(MCInst &Inst, unsigned Val,
603                                             uint64_t Address,
604                                             const MCDisassembler *Decoder);
605 static DecodeStatus DecodeForVMRSandVMSR(MCInst &Inst, unsigned Val,
606                                          uint64_t Address,
607                                          const MCDisassembler *Decoder);
608 
609 template <bool isSigned, bool isNeg, bool zeroPermitted, int size>
610 static DecodeStatus DecodeBFLabelOperand(MCInst &Inst, unsigned val,
611                                          uint64_t Address,
612                                          const MCDisassembler *Decoder);
613 static DecodeStatus DecodeBFAfterTargetOperand(MCInst &Inst, unsigned val,
614                                                uint64_t Address,
615                                                const MCDisassembler *Decoder);
616 static DecodeStatus DecodePredNoALOperand(MCInst &Inst, unsigned Val,
617                                           uint64_t Address,
618                                           const MCDisassembler *Decoder);
619 static DecodeStatus DecodeLOLoop(MCInst &Inst, unsigned Insn, uint64_t Address,
620                                  const MCDisassembler *Decoder);
621 static DecodeStatus DecodeLongShiftOperand(MCInst &Inst, unsigned Val,
622                                            uint64_t Address,
623                                            const MCDisassembler *Decoder);
624 static DecodeStatus DecodeVSCCLRM(MCInst &Inst, unsigned Insn, uint64_t Address,
625                                   const MCDisassembler *Decoder);
626 static DecodeStatus DecodeVPTMaskOperand(MCInst &Inst, unsigned Val,
627                                          uint64_t Address,
628                                          const MCDisassembler *Decoder);
629 static DecodeStatus DecodeVpredROperand(MCInst &Inst, unsigned Val,
630                                         uint64_t Address,
631                                         const MCDisassembler *Decoder);
632 static DecodeStatus DecodeVpredNOperand(MCInst &Inst, unsigned Val,
633                                         uint64_t Address,
634                                         const MCDisassembler *Decoder);
635 static DecodeStatus
636 DecodeRestrictedIPredicateOperand(MCInst &Inst, unsigned Val, uint64_t Address,
637                                   const MCDisassembler *Decoder);
638 static DecodeStatus
639 DecodeRestrictedSPredicateOperand(MCInst &Inst, unsigned Val, uint64_t Address,
640                                   const MCDisassembler *Decoder);
641 static DecodeStatus
642 DecodeRestrictedUPredicateOperand(MCInst &Inst, unsigned Val, uint64_t Address,
643                                   const MCDisassembler *Decoder);
644 static DecodeStatus
645 DecodeRestrictedFPPredicateOperand(MCInst &Inst, unsigned Val, uint64_t Address,
646                                    const MCDisassembler *Decoder);
647 template <bool Writeback>
648 static DecodeStatus DecodeVSTRVLDR_SYSREG(MCInst &Inst, unsigned Insn,
649                                           uint64_t Address,
650                                           const MCDisassembler *Decoder);
651 template <int shift>
652 static DecodeStatus DecodeMVE_MEM_1_pre(MCInst &Inst, unsigned Val,
653                                         uint64_t Address,
654                                         const MCDisassembler *Decoder);
655 template <int shift>
656 static DecodeStatus DecodeMVE_MEM_2_pre(MCInst &Inst, unsigned Val,
657                                         uint64_t Address,
658                                         const MCDisassembler *Decoder);
659 template <int shift>
660 static DecodeStatus DecodeMVE_MEM_3_pre(MCInst &Inst, unsigned Val,
661                                         uint64_t Address,
662                                         const MCDisassembler *Decoder);
663 template <unsigned MinLog, unsigned MaxLog>
664 static DecodeStatus DecodePowerTwoOperand(MCInst &Inst, unsigned Val,
665                                           uint64_t Address,
666                                           const MCDisassembler *Decoder);
667 template <unsigned start>
668 static DecodeStatus
669 DecodeMVEPairVectorIndexOperand(MCInst &Inst, unsigned Val, uint64_t Address,
670                                 const MCDisassembler *Decoder);
671 static DecodeStatus DecodeMVEVMOVQtoDReg(MCInst &Inst, unsigned Insn,
672                                          uint64_t Address,
673                                          const MCDisassembler *Decoder);
674 static DecodeStatus DecodeMVEVMOVDRegtoQ(MCInst &Inst, unsigned Insn,
675                                          uint64_t Address,
676                                          const MCDisassembler *Decoder);
677 static DecodeStatus DecodeMVEVCVTt1fp(MCInst &Inst, unsigned Insn,
678                                       uint64_t Address,
679                                       const MCDisassembler *Decoder);
680 typedef DecodeStatus OperandDecoder(MCInst &Inst, unsigned Val,
681                                     uint64_t Address,
682                                     const MCDisassembler *Decoder);
683 template <bool scalar, OperandDecoder predicate_decoder>
684 static DecodeStatus DecodeMVEVCMP(MCInst &Inst, unsigned Insn, uint64_t Address,
685                                   const MCDisassembler *Decoder);
686 static DecodeStatus DecodeMveVCTP(MCInst &Inst, unsigned Insn, uint64_t Address,
687                                   const MCDisassembler *Decoder);
688 static DecodeStatus DecodeMVEVPNOT(MCInst &Inst, unsigned Insn,
689                                    uint64_t Address,
690                                    const MCDisassembler *Decoder);
691 static DecodeStatus
692 DecodeMVEOverlappingLongShift(MCInst &Inst, unsigned Insn, uint64_t Address,
693                               const MCDisassembler *Decoder);
694 static DecodeStatus DecodeT2AddSubSPImm(MCInst &Inst, unsigned Insn,
695                                         uint64_t Address,
696                                         const MCDisassembler *Decoder);
697 
698 #include "ARMGenDisassemblerTables.inc"
699 
700 static MCDisassembler *createARMDisassembler(const Target &T,
701                                              const MCSubtargetInfo &STI,
702                                              MCContext &Ctx) {
703   return new ARMDisassembler(STI, Ctx);
704 }
705 
706 // Post-decoding checks
707 static DecodeStatus checkDecodedInstruction(MCInst &MI, uint64_t &Size,
708                                             uint64_t Address, raw_ostream &CS,
709                                             uint32_t Insn,
710                                             DecodeStatus Result) {
711   switch (MI.getOpcode()) {
712     case ARM::HVC: {
713       // HVC is undefined if condition = 0xf otherwise upredictable
714       // if condition != 0xe
715       uint32_t Cond = (Insn >> 28) & 0xF;
716       if (Cond == 0xF)
717         return MCDisassembler::Fail;
718       if (Cond != 0xE)
719         return MCDisassembler::SoftFail;
720       return Result;
721     }
722     case ARM::t2ADDri:
723     case ARM::t2ADDri12:
724     case ARM::t2ADDrr:
725     case ARM::t2ADDrs:
726     case ARM::t2SUBri:
727     case ARM::t2SUBri12:
728     case ARM::t2SUBrr:
729     case ARM::t2SUBrs:
730       if (MI.getOperand(0).getReg() == ARM::SP &&
731           MI.getOperand(1).getReg() != ARM::SP)
732         return MCDisassembler::SoftFail;
733       return Result;
734     default: return Result;
735   }
736 }
737 
738 uint64_t ARMDisassembler::suggestBytesToSkip(ArrayRef<uint8_t> Bytes,
739                                              uint64_t Address) const {
740   // In Arm state, instructions are always 4 bytes wide, so there's no
741   // point in skipping any smaller number of bytes if an instruction
742   // can't be decoded.
743   if (!STI.getFeatureBits()[ARM::ModeThumb])
744     return 4;
745 
746   // In a Thumb instruction stream, a halfword is a standalone 2-byte
747   // instruction if and only if its value is less than 0xE800.
748   // Otherwise, it's the first halfword of a 4-byte instruction.
749   //
750   // So, if we can see the upcoming halfword, we can judge on that
751   // basis, and maybe skip a whole 4-byte instruction that we don't
752   // know how to decode, without accidentally trying to interpret its
753   // second half as something else.
754   //
755   // If we don't have the instruction data available, we just have to
756   // recommend skipping the minimum sensible distance, which is 2
757   // bytes.
758   if (Bytes.size() < 2)
759     return 2;
760 
761   uint16_t Insn16 = llvm::support::endian::read<uint16_t>(
762       Bytes.data(), InstructionEndianness);
763   return Insn16 < 0xE800 ? 2 : 4;
764 }
765 
766 DecodeStatus ARMDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
767                                              ArrayRef<uint8_t> Bytes,
768                                              uint64_t Address,
769                                              raw_ostream &CS) const {
770   if (STI.getFeatureBits()[ARM::ModeThumb])
771     return getThumbInstruction(MI, Size, Bytes, Address, CS);
772   return getARMInstruction(MI, Size, Bytes, Address, CS);
773 }
774 
775 DecodeStatus ARMDisassembler::getARMInstruction(MCInst &MI, uint64_t &Size,
776                                                 ArrayRef<uint8_t> Bytes,
777                                                 uint64_t Address,
778                                                 raw_ostream &CS) const {
779   CommentStream = &CS;
780 
781   assert(!STI.getFeatureBits()[ARM::ModeThumb] &&
782          "Asked to disassemble an ARM instruction but Subtarget is in Thumb "
783          "mode!");
784 
785   // We want to read exactly 4 bytes of data.
786   if (Bytes.size() < 4) {
787     Size = 0;
788     return MCDisassembler::Fail;
789   }
790 
791   // Encoded as a 32-bit word in the stream.
792   uint32_t Insn = llvm::support::endian::read<uint32_t>(Bytes.data(),
793                                                         InstructionEndianness);
794 
795   // Calling the auto-generated decoder function.
796   DecodeStatus Result =
797       decodeInstruction(DecoderTableARM32, MI, Insn, Address, this, STI);
798   if (Result != MCDisassembler::Fail) {
799     Size = 4;
800     return checkDecodedInstruction(MI, Size, Address, CS, Insn, Result);
801   }
802 
803   struct DecodeTable {
804     const uint8_t *P;
805     bool DecodePred;
806   };
807 
808   const DecodeTable Tables[] = {
809       {DecoderTableVFP32, false},      {DecoderTableVFPV832, false},
810       {DecoderTableNEONData32, true},  {DecoderTableNEONLoadStore32, true},
811       {DecoderTableNEONDup32, true},   {DecoderTablev8NEON32, false},
812       {DecoderTablev8Crypto32, false},
813   };
814 
815   for (auto Table : Tables) {
816     Result = decodeInstruction(Table.P, MI, Insn, Address, this, STI);
817     if (Result != MCDisassembler::Fail) {
818       Size = 4;
819       // Add a fake predicate operand, because we share these instruction
820       // definitions with Thumb2 where these instructions are predicable.
821       if (Table.DecodePred && !DecodePredicateOperand(MI, 0xE, Address, this))
822         return MCDisassembler::Fail;
823       return Result;
824     }
825   }
826 
827   Result =
828       decodeInstruction(DecoderTableCoProc32, MI, Insn, Address, this, STI);
829   if (Result != MCDisassembler::Fail) {
830     Size = 4;
831     return checkDecodedInstruction(MI, Size, Address, CS, Insn, Result);
832   }
833 
834   Size = 4;
835   return MCDisassembler::Fail;
836 }
837 
838 namespace llvm {
839 
840 extern const MCInstrDesc ARMInsts[];
841 
842 } // end namespace llvm
843 
844 /// tryAddingSymbolicOperand - trys to add a symbolic operand in place of the
845 /// immediate Value in the MCInst.  The immediate Value has had any PC
846 /// adjustment made by the caller.  If the instruction is a branch instruction
847 /// then isBranch is true, else false.  If the getOpInfo() function was set as
848 /// part of the setupForSymbolicDisassembly() call then that function is called
849 /// to get any symbolic information at the Address for this instruction.  If
850 /// that returns non-zero then the symbolic information it returns is used to
851 /// create an MCExpr and that is added as an operand to the MCInst.  If
852 /// getOpInfo() returns zero and isBranch is true then a symbol look up for
853 /// Value is done and if a symbol is found an MCExpr is created with that, else
854 /// an MCExpr with Value is created.  This function returns true if it adds an
855 /// operand to the MCInst and false otherwise.
856 static bool tryAddingSymbolicOperand(uint64_t Address, int32_t Value,
857                                      bool isBranch, uint64_t InstSize,
858                                      MCInst &MI,
859                                      const MCDisassembler *Decoder) {
860   // FIXME: Does it make sense for value to be negative?
861   return Decoder->tryAddingSymbolicOperand(MI, (uint32_t)Value, Address,
862                                            isBranch, /*Offset=*/0, /*OpSize=*/0,
863                                            InstSize);
864 }
865 
866 /// tryAddingPcLoadReferenceComment - trys to add a comment as to what is being
867 /// referenced by a load instruction with the base register that is the Pc.
868 /// These can often be values in a literal pool near the Address of the
869 /// instruction.  The Address of the instruction and its immediate Value are
870 /// used as a possible literal pool entry.  The SymbolLookUp call back will
871 /// return the name of a symbol referenced by the literal pool's entry if
872 /// the referenced address is that of a symbol.  Or it will return a pointer to
873 /// a literal 'C' string if the referenced address of the literal pool's entry
874 /// is an address into a section with 'C' string literals.
875 static void tryAddingPcLoadReferenceComment(uint64_t Address, int Value,
876                                             const MCDisassembler *Decoder) {
877   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
878   Dis->tryAddingPcLoadReferenceComment(Value, Address);
879 }
880 
881 // Thumb1 instructions don't have explicit S bits.  Rather, they
882 // implicitly set CPSR.  Since it's not represented in the encoding, the
883 // auto-generated decoder won't inject the CPSR operand.  We need to fix
884 // that as a post-pass.
885 static void AddThumb1SBit(MCInst &MI, bool InITBlock) {
886   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
887   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
888   MCInst::iterator I = MI.begin();
889   for (unsigned i = 0; i < NumOps; ++i, ++I) {
890     if (I == MI.end()) break;
891     if (OpInfo[i].isOptionalDef() && OpInfo[i].RegClass == ARM::CCRRegClassID) {
892       if (i > 0 && OpInfo[i-1].isPredicate()) continue;
893       MI.insert(I, MCOperand::createReg(InITBlock ? 0 : ARM::CPSR));
894       return;
895     }
896   }
897 
898   MI.insert(I, MCOperand::createReg(InITBlock ? 0 : ARM::CPSR));
899 }
900 
901 static bool isVectorPredicable(unsigned Opcode) {
902   const MCOperandInfo *OpInfo = ARMInsts[Opcode].OpInfo;
903   unsigned short NumOps = ARMInsts[Opcode].NumOperands;
904   for (unsigned i = 0; i < NumOps; ++i) {
905     if (ARM::isVpred(OpInfo[i].OperandType))
906       return true;
907   }
908   return false;
909 }
910 
911 // Most Thumb instructions don't have explicit predicates in the
912 // encoding, but rather get their predicates from IT context.  We need
913 // to fix up the predicate operands using this context information as a
914 // post-pass.
915 MCDisassembler::DecodeStatus
916 ARMDisassembler::AddThumbPredicate(MCInst &MI) const {
917   MCDisassembler::DecodeStatus S = Success;
918 
919   const FeatureBitset &FeatureBits = getSubtargetInfo().getFeatureBits();
920 
921   // A few instructions actually have predicates encoded in them.  Don't
922   // try to overwrite it if we're seeing one of those.
923   switch (MI.getOpcode()) {
924     case ARM::tBcc:
925     case ARM::t2Bcc:
926     case ARM::tCBZ:
927     case ARM::tCBNZ:
928     case ARM::tCPS:
929     case ARM::t2CPS3p:
930     case ARM::t2CPS2p:
931     case ARM::t2CPS1p:
932     case ARM::t2CSEL:
933     case ARM::t2CSINC:
934     case ARM::t2CSINV:
935     case ARM::t2CSNEG:
936     case ARM::tMOVSr:
937     case ARM::tSETEND:
938       // Some instructions (mostly conditional branches) are not
939       // allowed in IT blocks.
940       if (ITBlock.instrInITBlock())
941         S = SoftFail;
942       else
943         return Success;
944       break;
945     case ARM::t2HINT:
946       if (MI.getOperand(0).getImm() == 0x10 && (FeatureBits[ARM::FeatureRAS]) != 0)
947         S = SoftFail;
948       break;
949     case ARM::tB:
950     case ARM::t2B:
951     case ARM::t2TBB:
952     case ARM::t2TBH:
953       // Some instructions (mostly unconditional branches) can
954       // only appears at the end of, or outside of, an IT.
955       if (ITBlock.instrInITBlock() && !ITBlock.instrLastInITBlock())
956         S = SoftFail;
957       break;
958     default:
959       break;
960   }
961 
962   // Warn on non-VPT predicable instruction in a VPT block and a VPT
963   // predicable instruction in an IT block
964   if ((!isVectorPredicable(MI.getOpcode()) && VPTBlock.instrInVPTBlock()) ||
965        (isVectorPredicable(MI.getOpcode()) && ITBlock.instrInITBlock()))
966     S = SoftFail;
967 
968   // If we're in an IT/VPT block, base the predicate on that.  Otherwise,
969   // assume a predicate of AL.
970   unsigned CC = ARMCC::AL;
971   unsigned VCC = ARMVCC::None;
972   if (ITBlock.instrInITBlock()) {
973     CC = ITBlock.getITCC();
974     ITBlock.advanceITState();
975   } else if (VPTBlock.instrInVPTBlock()) {
976     VCC = VPTBlock.getVPTPred();
977     VPTBlock.advanceVPTState();
978   }
979 
980   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
981   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
982 
983   MCInst::iterator CCI = MI.begin();
984   for (unsigned i = 0; i < NumOps; ++i, ++CCI) {
985     if (OpInfo[i].isPredicate() || CCI == MI.end()) break;
986   }
987 
988   if (ARMInsts[MI.getOpcode()].isPredicable()) {
989     CCI = MI.insert(CCI, MCOperand::createImm(CC));
990     ++CCI;
991     if (CC == ARMCC::AL)
992       MI.insert(CCI, MCOperand::createReg(0));
993     else
994       MI.insert(CCI, MCOperand::createReg(ARM::CPSR));
995   } else if (CC != ARMCC::AL) {
996     Check(S, SoftFail);
997   }
998 
999   MCInst::iterator VCCI = MI.begin();
1000   unsigned VCCPos;
1001   for (VCCPos = 0; VCCPos < NumOps; ++VCCPos, ++VCCI) {
1002     if (ARM::isVpred(OpInfo[VCCPos].OperandType) || VCCI == MI.end()) break;
1003   }
1004 
1005   if (isVectorPredicable(MI.getOpcode())) {
1006     VCCI = MI.insert(VCCI, MCOperand::createImm(VCC));
1007     ++VCCI;
1008     if (VCC == ARMVCC::None)
1009       VCCI = MI.insert(VCCI, MCOperand::createReg(0));
1010     else
1011       VCCI = MI.insert(VCCI, MCOperand::createReg(ARM::P0));
1012     ++VCCI;
1013     VCCI = MI.insert(VCCI, MCOperand::createReg(0));
1014     ++VCCI;
1015     if (OpInfo[VCCPos].OperandType == ARM::OPERAND_VPRED_R) {
1016       int TiedOp = ARMInsts[MI.getOpcode()].getOperandConstraint(
1017         VCCPos + 3, MCOI::TIED_TO);
1018       assert(TiedOp >= 0 &&
1019              "Inactive register in vpred_r is not tied to an output!");
1020       // Copy the operand to ensure it's not invalidated when MI grows.
1021       MI.insert(VCCI, MCOperand(MI.getOperand(TiedOp)));
1022     }
1023   } else if (VCC != ARMVCC::None) {
1024     Check(S, SoftFail);
1025   }
1026 
1027   return S;
1028 }
1029 
1030 // Thumb VFP instructions are a special case.  Because we share their
1031 // encodings between ARM and Thumb modes, and they are predicable in ARM
1032 // mode, the auto-generated decoder will give them an (incorrect)
1033 // predicate operand.  We need to rewrite these operands based on the IT
1034 // context as a post-pass.
1035 void ARMDisassembler::UpdateThumbVFPPredicate(
1036   DecodeStatus &S, MCInst &MI) const {
1037   unsigned CC;
1038   CC = ITBlock.getITCC();
1039   if (CC == 0xF)
1040     CC = ARMCC::AL;
1041   if (ITBlock.instrInITBlock())
1042     ITBlock.advanceITState();
1043   else if (VPTBlock.instrInVPTBlock()) {
1044     CC = VPTBlock.getVPTPred();
1045     VPTBlock.advanceVPTState();
1046   }
1047 
1048   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
1049   MCInst::iterator I = MI.begin();
1050   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
1051   for (unsigned i = 0; i < NumOps; ++i, ++I) {
1052     if (OpInfo[i].isPredicate() ) {
1053       if (CC != ARMCC::AL && !ARMInsts[MI.getOpcode()].isPredicable())
1054         Check(S, SoftFail);
1055       I->setImm(CC);
1056       ++I;
1057       if (CC == ARMCC::AL)
1058         I->setReg(0);
1059       else
1060         I->setReg(ARM::CPSR);
1061       return;
1062     }
1063   }
1064 }
1065 
1066 DecodeStatus ARMDisassembler::getThumbInstruction(MCInst &MI, uint64_t &Size,
1067                                                   ArrayRef<uint8_t> Bytes,
1068                                                   uint64_t Address,
1069                                                   raw_ostream &CS) const {
1070   CommentStream = &CS;
1071 
1072   assert(STI.getFeatureBits()[ARM::ModeThumb] &&
1073          "Asked to disassemble in Thumb mode but Subtarget is in ARM mode!");
1074 
1075   // We want to read exactly 2 bytes of data.
1076   if (Bytes.size() < 2) {
1077     Size = 0;
1078     return MCDisassembler::Fail;
1079   }
1080 
1081   uint16_t Insn16 = llvm::support::endian::read<uint16_t>(
1082       Bytes.data(), InstructionEndianness);
1083   DecodeStatus Result =
1084       decodeInstruction(DecoderTableThumb16, MI, Insn16, Address, this, STI);
1085   if (Result != MCDisassembler::Fail) {
1086     Size = 2;
1087     Check(Result, AddThumbPredicate(MI));
1088     return Result;
1089   }
1090 
1091   Result = decodeInstruction(DecoderTableThumbSBit16, MI, Insn16, Address, this,
1092                              STI);
1093   if (Result) {
1094     Size = 2;
1095     bool InITBlock = ITBlock.instrInITBlock();
1096     Check(Result, AddThumbPredicate(MI));
1097     AddThumb1SBit(MI, InITBlock);
1098     return Result;
1099   }
1100 
1101   Result =
1102       decodeInstruction(DecoderTableThumb216, MI, Insn16, Address, this, STI);
1103   if (Result != MCDisassembler::Fail) {
1104     Size = 2;
1105 
1106     // Nested IT blocks are UNPREDICTABLE.  Must be checked before we add
1107     // the Thumb predicate.
1108     if (MI.getOpcode() == ARM::t2IT && ITBlock.instrInITBlock())
1109       Result = MCDisassembler::SoftFail;
1110 
1111     Check(Result, AddThumbPredicate(MI));
1112 
1113     // If we find an IT instruction, we need to parse its condition
1114     // code and mask operands so that we can apply them correctly
1115     // to the subsequent instructions.
1116     if (MI.getOpcode() == ARM::t2IT) {
1117       unsigned Firstcond = MI.getOperand(0).getImm();
1118       unsigned Mask = MI.getOperand(1).getImm();
1119       ITBlock.setITState(Firstcond, Mask);
1120 
1121       // An IT instruction that would give a 'NV' predicate is unpredictable.
1122       if (Firstcond == ARMCC::AL && !isPowerOf2_32(Mask))
1123         CS << "unpredictable IT predicate sequence";
1124     }
1125 
1126     return Result;
1127   }
1128 
1129   // We want to read exactly 4 bytes of data.
1130   if (Bytes.size() < 4) {
1131     Size = 0;
1132     return MCDisassembler::Fail;
1133   }
1134 
1135   uint32_t Insn32 =
1136       (uint32_t(Insn16) << 16) | llvm::support::endian::read<uint16_t>(
1137                                      Bytes.data() + 2, InstructionEndianness);
1138 
1139   Result =
1140       decodeInstruction(DecoderTableMVE32, MI, Insn32, Address, this, STI);
1141   if (Result != MCDisassembler::Fail) {
1142     Size = 4;
1143 
1144     // Nested VPT blocks are UNPREDICTABLE. Must be checked before we add
1145     // the VPT predicate.
1146     if (isVPTOpcode(MI.getOpcode()) && VPTBlock.instrInVPTBlock())
1147       Result = MCDisassembler::SoftFail;
1148 
1149     Check(Result, AddThumbPredicate(MI));
1150 
1151     if (isVPTOpcode(MI.getOpcode())) {
1152       unsigned Mask = MI.getOperand(0).getImm();
1153       VPTBlock.setVPTState(Mask);
1154     }
1155 
1156     return Result;
1157   }
1158 
1159   Result =
1160       decodeInstruction(DecoderTableThumb32, MI, Insn32, Address, this, STI);
1161   if (Result != MCDisassembler::Fail) {
1162     Size = 4;
1163     bool InITBlock = ITBlock.instrInITBlock();
1164     Check(Result, AddThumbPredicate(MI));
1165     AddThumb1SBit(MI, InITBlock);
1166     return Result;
1167   }
1168 
1169   Result =
1170       decodeInstruction(DecoderTableThumb232, MI, Insn32, Address, this, STI);
1171   if (Result != MCDisassembler::Fail) {
1172     Size = 4;
1173     Check(Result, AddThumbPredicate(MI));
1174     return checkDecodedInstruction(MI, Size, Address, CS, Insn32, Result);
1175   }
1176 
1177   if (fieldFromInstruction(Insn32, 28, 4) == 0xE) {
1178     Result =
1179         decodeInstruction(DecoderTableVFP32, MI, Insn32, Address, this, STI);
1180     if (Result != MCDisassembler::Fail) {
1181       Size = 4;
1182       UpdateThumbVFPPredicate(Result, MI);
1183       return Result;
1184     }
1185   }
1186 
1187   Result =
1188       decodeInstruction(DecoderTableVFPV832, MI, Insn32, Address, this, STI);
1189   if (Result != MCDisassembler::Fail) {
1190     Size = 4;
1191     return Result;
1192   }
1193 
1194   if (fieldFromInstruction(Insn32, 28, 4) == 0xE) {
1195     Result = decodeInstruction(DecoderTableNEONDup32, MI, Insn32, Address, this,
1196                                STI);
1197     if (Result != MCDisassembler::Fail) {
1198       Size = 4;
1199       Check(Result, AddThumbPredicate(MI));
1200       return Result;
1201     }
1202   }
1203 
1204   if (fieldFromInstruction(Insn32, 24, 8) == 0xF9) {
1205     uint32_t NEONLdStInsn = Insn32;
1206     NEONLdStInsn &= 0xF0FFFFFF;
1207     NEONLdStInsn |= 0x04000000;
1208     Result = decodeInstruction(DecoderTableNEONLoadStore32, MI, NEONLdStInsn,
1209                                Address, this, STI);
1210     if (Result != MCDisassembler::Fail) {
1211       Size = 4;
1212       Check(Result, AddThumbPredicate(MI));
1213       return Result;
1214     }
1215   }
1216 
1217   if (fieldFromInstruction(Insn32, 24, 4) == 0xF) {
1218     uint32_t NEONDataInsn = Insn32;
1219     NEONDataInsn &= 0xF0FFFFFF; // Clear bits 27-24
1220     NEONDataInsn |= (NEONDataInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
1221     NEONDataInsn |= 0x12000000; // Set bits 28 and 25
1222     Result = decodeInstruction(DecoderTableNEONData32, MI, NEONDataInsn,
1223                                Address, this, STI);
1224     if (Result != MCDisassembler::Fail) {
1225       Size = 4;
1226       Check(Result, AddThumbPredicate(MI));
1227       return Result;
1228     }
1229 
1230     uint32_t NEONCryptoInsn = Insn32;
1231     NEONCryptoInsn &= 0xF0FFFFFF; // Clear bits 27-24
1232     NEONCryptoInsn |= (NEONCryptoInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
1233     NEONCryptoInsn |= 0x12000000; // Set bits 28 and 25
1234     Result = decodeInstruction(DecoderTablev8Crypto32, MI, NEONCryptoInsn,
1235                                Address, this, STI);
1236     if (Result != MCDisassembler::Fail) {
1237       Size = 4;
1238       return Result;
1239     }
1240 
1241     uint32_t NEONv8Insn = Insn32;
1242     NEONv8Insn &= 0xF3FFFFFF; // Clear bits 27-26
1243     Result = decodeInstruction(DecoderTablev8NEON32, MI, NEONv8Insn, Address,
1244                                this, STI);
1245     if (Result != MCDisassembler::Fail) {
1246       Size = 4;
1247       return Result;
1248     }
1249   }
1250 
1251   uint32_t Coproc = fieldFromInstruction(Insn32, 8, 4);
1252   const uint8_t *DecoderTable = ARM::isCDECoproc(Coproc, STI)
1253                                     ? DecoderTableThumb2CDE32
1254                                     : DecoderTableThumb2CoProc32;
1255   Result =
1256       decodeInstruction(DecoderTable, MI, Insn32, Address, this, STI);
1257   if (Result != MCDisassembler::Fail) {
1258     Size = 4;
1259     Check(Result, AddThumbPredicate(MI));
1260     return Result;
1261   }
1262 
1263   Size = 0;
1264   return MCDisassembler::Fail;
1265 }
1266 
1267 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeARMDisassembler() {
1268   TargetRegistry::RegisterMCDisassembler(getTheARMLETarget(),
1269                                          createARMDisassembler);
1270   TargetRegistry::RegisterMCDisassembler(getTheARMBETarget(),
1271                                          createARMDisassembler);
1272   TargetRegistry::RegisterMCDisassembler(getTheThumbLETarget(),
1273                                          createARMDisassembler);
1274   TargetRegistry::RegisterMCDisassembler(getTheThumbBETarget(),
1275                                          createARMDisassembler);
1276 }
1277 
1278 static const uint16_t GPRDecoderTable[] = {
1279   ARM::R0, ARM::R1, ARM::R2, ARM::R3,
1280   ARM::R4, ARM::R5, ARM::R6, ARM::R7,
1281   ARM::R8, ARM::R9, ARM::R10, ARM::R11,
1282   ARM::R12, ARM::SP, ARM::LR, ARM::PC
1283 };
1284 
1285 static const uint16_t CLRMGPRDecoderTable[] = {
1286   ARM::R0, ARM::R1, ARM::R2, ARM::R3,
1287   ARM::R4, ARM::R5, ARM::R6, ARM::R7,
1288   ARM::R8, ARM::R9, ARM::R10, ARM::R11,
1289   ARM::R12, 0, ARM::LR, ARM::APSR
1290 };
1291 
1292 static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1293                                            uint64_t Address,
1294                                            const MCDisassembler *Decoder) {
1295   if (RegNo > 15)
1296     return MCDisassembler::Fail;
1297 
1298   unsigned Register = GPRDecoderTable[RegNo];
1299   Inst.addOperand(MCOperand::createReg(Register));
1300   return MCDisassembler::Success;
1301 }
1302 
1303 static DecodeStatus DecodeCLRMGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1304                                                uint64_t Address,
1305                                                const MCDisassembler *Decoder) {
1306   if (RegNo > 15)
1307     return MCDisassembler::Fail;
1308 
1309   unsigned Register = CLRMGPRDecoderTable[RegNo];
1310   if (Register == 0)
1311     return MCDisassembler::Fail;
1312 
1313   Inst.addOperand(MCOperand::createReg(Register));
1314   return MCDisassembler::Success;
1315 }
1316 
1317 static DecodeStatus DecodeGPRnopcRegisterClass(MCInst &Inst, unsigned RegNo,
1318                                                uint64_t Address,
1319                                                const MCDisassembler *Decoder) {
1320   DecodeStatus S = MCDisassembler::Success;
1321 
1322   if (RegNo == 15)
1323     S = MCDisassembler::SoftFail;
1324 
1325   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1326 
1327   return S;
1328 }
1329 
1330 static DecodeStatus DecodeGPRnospRegisterClass(MCInst &Inst, unsigned RegNo,
1331                                                uint64_t Address,
1332                                                const MCDisassembler *Decoder) {
1333   DecodeStatus S = MCDisassembler::Success;
1334 
1335   if (RegNo == 13)
1336     S = MCDisassembler::SoftFail;
1337 
1338   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1339 
1340   return S;
1341 }
1342 
1343 static DecodeStatus
1344 DecodeGPRwithAPSRRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Address,
1345                                const MCDisassembler *Decoder) {
1346   DecodeStatus S = MCDisassembler::Success;
1347 
1348   if (RegNo == 15)
1349   {
1350     Inst.addOperand(MCOperand::createReg(ARM::APSR_NZCV));
1351     return MCDisassembler::Success;
1352   }
1353 
1354   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1355   return S;
1356 }
1357 
1358 static DecodeStatus
1359 DecodeGPRwithZRRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Address,
1360                              const MCDisassembler *Decoder) {
1361   DecodeStatus S = MCDisassembler::Success;
1362 
1363   if (RegNo == 15)
1364   {
1365     Inst.addOperand(MCOperand::createReg(ARM::ZR));
1366     return MCDisassembler::Success;
1367   }
1368 
1369   if (RegNo == 13)
1370     Check(S, MCDisassembler::SoftFail);
1371 
1372   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1373   return S;
1374 }
1375 
1376 static DecodeStatus
1377 DecodeGPRwithZRnospRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Address,
1378                                  const MCDisassembler *Decoder) {
1379   DecodeStatus S = MCDisassembler::Success;
1380   if (RegNo == 13)
1381     return MCDisassembler::Fail;
1382   Check(S, DecodeGPRwithZRRegisterClass(Inst, RegNo, Address, Decoder));
1383   return S;
1384 }
1385 
1386 static DecodeStatus DecodetGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1387                                             uint64_t Address,
1388                                             const MCDisassembler *Decoder) {
1389   if (RegNo > 7)
1390     return MCDisassembler::Fail;
1391   return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
1392 }
1393 
1394 static const uint16_t GPRPairDecoderTable[] = {
1395   ARM::R0_R1, ARM::R2_R3,   ARM::R4_R5,  ARM::R6_R7,
1396   ARM::R8_R9, ARM::R10_R11, ARM::R12_SP
1397 };
1398 
1399 static DecodeStatus DecodeGPRPairRegisterClass(MCInst &Inst, unsigned RegNo,
1400                                                uint64_t Address,
1401                                                const MCDisassembler *Decoder) {
1402   DecodeStatus S = MCDisassembler::Success;
1403 
1404   // According to the Arm ARM RegNo = 14 is undefined, but we return fail
1405   // rather than SoftFail as there is no GPRPair table entry for index 7.
1406   if (RegNo > 13)
1407     return MCDisassembler::Fail;
1408 
1409   if (RegNo & 1)
1410      S = MCDisassembler::SoftFail;
1411 
1412   unsigned RegisterPair = GPRPairDecoderTable[RegNo/2];
1413   Inst.addOperand(MCOperand::createReg(RegisterPair));
1414   return S;
1415 }
1416 
1417 static DecodeStatus
1418 DecodeGPRPairnospRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Address,
1419                                const MCDisassembler *Decoder) {
1420   if (RegNo > 13)
1421     return MCDisassembler::Fail;
1422 
1423   unsigned RegisterPair = GPRPairDecoderTable[RegNo/2];
1424   Inst.addOperand(MCOperand::createReg(RegisterPair));
1425 
1426   if ((RegNo & 1) || RegNo > 10)
1427      return MCDisassembler::SoftFail;
1428   return MCDisassembler::Success;
1429 }
1430 
1431 static DecodeStatus DecodeGPRspRegisterClass(MCInst &Inst, unsigned RegNo,
1432                                              uint64_t Address,
1433                                              const MCDisassembler *Decoder) {
1434   if (RegNo != 13)
1435     return MCDisassembler::Fail;
1436 
1437   unsigned Register = GPRDecoderTable[RegNo];
1438   Inst.addOperand(MCOperand::createReg(Register));
1439   return MCDisassembler::Success;
1440 }
1441 
1442 static DecodeStatus DecodetcGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1443                                              uint64_t Address,
1444                                              const MCDisassembler *Decoder) {
1445   unsigned Register = 0;
1446   switch (RegNo) {
1447     case 0:
1448       Register = ARM::R0;
1449       break;
1450     case 1:
1451       Register = ARM::R1;
1452       break;
1453     case 2:
1454       Register = ARM::R2;
1455       break;
1456     case 3:
1457       Register = ARM::R3;
1458       break;
1459     case 9:
1460       Register = ARM::R9;
1461       break;
1462     case 12:
1463       Register = ARM::R12;
1464       break;
1465     default:
1466       return MCDisassembler::Fail;
1467     }
1468 
1469   Inst.addOperand(MCOperand::createReg(Register));
1470   return MCDisassembler::Success;
1471 }
1472 
1473 static DecodeStatus DecoderGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1474                                             uint64_t Address,
1475                                             const MCDisassembler *Decoder) {
1476   DecodeStatus S = MCDisassembler::Success;
1477 
1478   const FeatureBitset &featureBits =
1479     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1480 
1481   if ((RegNo == 13 && !featureBits[ARM::HasV8Ops]) || RegNo == 15)
1482     S = MCDisassembler::SoftFail;
1483 
1484   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1485   return S;
1486 }
1487 
1488 static const uint16_t SPRDecoderTable[] = {
1489      ARM::S0,  ARM::S1,  ARM::S2,  ARM::S3,
1490      ARM::S4,  ARM::S5,  ARM::S6,  ARM::S7,
1491      ARM::S8,  ARM::S9, ARM::S10, ARM::S11,
1492     ARM::S12, ARM::S13, ARM::S14, ARM::S15,
1493     ARM::S16, ARM::S17, ARM::S18, ARM::S19,
1494     ARM::S20, ARM::S21, ARM::S22, ARM::S23,
1495     ARM::S24, ARM::S25, ARM::S26, ARM::S27,
1496     ARM::S28, ARM::S29, ARM::S30, ARM::S31
1497 };
1498 
1499 static DecodeStatus DecodeSPRRegisterClass(MCInst &Inst, unsigned RegNo,
1500                                            uint64_t Address,
1501                                            const MCDisassembler *Decoder) {
1502   if (RegNo > 31)
1503     return MCDisassembler::Fail;
1504 
1505   unsigned Register = SPRDecoderTable[RegNo];
1506   Inst.addOperand(MCOperand::createReg(Register));
1507   return MCDisassembler::Success;
1508 }
1509 
1510 static DecodeStatus DecodeHPRRegisterClass(MCInst &Inst, unsigned RegNo,
1511                                            uint64_t Address,
1512                                            const MCDisassembler *Decoder) {
1513   return DecodeSPRRegisterClass(Inst, RegNo, Address, Decoder);
1514 }
1515 
1516 static const uint16_t DPRDecoderTable[] = {
1517      ARM::D0,  ARM::D1,  ARM::D2,  ARM::D3,
1518      ARM::D4,  ARM::D5,  ARM::D6,  ARM::D7,
1519      ARM::D8,  ARM::D9, ARM::D10, ARM::D11,
1520     ARM::D12, ARM::D13, ARM::D14, ARM::D15,
1521     ARM::D16, ARM::D17, ARM::D18, ARM::D19,
1522     ARM::D20, ARM::D21, ARM::D22, ARM::D23,
1523     ARM::D24, ARM::D25, ARM::D26, ARM::D27,
1524     ARM::D28, ARM::D29, ARM::D30, ARM::D31
1525 };
1526 
1527 static DecodeStatus DecodeDPRRegisterClass(MCInst &Inst, unsigned RegNo,
1528                                            uint64_t Address,
1529                                            const MCDisassembler *Decoder) {
1530   const FeatureBitset &featureBits =
1531     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1532 
1533   bool hasD32 = featureBits[ARM::FeatureD32];
1534 
1535   if (RegNo > 31 || (!hasD32 && RegNo > 15))
1536     return MCDisassembler::Fail;
1537 
1538   unsigned Register = DPRDecoderTable[RegNo];
1539   Inst.addOperand(MCOperand::createReg(Register));
1540   return MCDisassembler::Success;
1541 }
1542 
1543 static DecodeStatus DecodeDPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
1544                                              uint64_t Address,
1545                                              const MCDisassembler *Decoder) {
1546   if (RegNo > 7)
1547     return MCDisassembler::Fail;
1548   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
1549 }
1550 
1551 static DecodeStatus DecodeSPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
1552                                              uint64_t Address,
1553                                              const MCDisassembler *Decoder) {
1554   if (RegNo > 15)
1555     return MCDisassembler::Fail;
1556   return DecodeSPRRegisterClass(Inst, RegNo, Address, Decoder);
1557 }
1558 
1559 static DecodeStatus DecodeDPR_VFP2RegisterClass(MCInst &Inst, unsigned RegNo,
1560                                                 uint64_t Address,
1561                                                 const MCDisassembler *Decoder) {
1562   if (RegNo > 15)
1563     return MCDisassembler::Fail;
1564   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
1565 }
1566 
1567 static const uint16_t QPRDecoderTable[] = {
1568      ARM::Q0,  ARM::Q1,  ARM::Q2,  ARM::Q3,
1569      ARM::Q4,  ARM::Q5,  ARM::Q6,  ARM::Q7,
1570      ARM::Q8,  ARM::Q9, ARM::Q10, ARM::Q11,
1571     ARM::Q12, ARM::Q13, ARM::Q14, ARM::Q15
1572 };
1573 
1574 static DecodeStatus DecodeQPRRegisterClass(MCInst &Inst, unsigned RegNo,
1575                                            uint64_t Address,
1576                                            const MCDisassembler *Decoder) {
1577   if (RegNo > 31 || (RegNo & 1) != 0)
1578     return MCDisassembler::Fail;
1579   RegNo >>= 1;
1580 
1581   unsigned Register = QPRDecoderTable[RegNo];
1582   Inst.addOperand(MCOperand::createReg(Register));
1583   return MCDisassembler::Success;
1584 }
1585 
1586 static const uint16_t DPairDecoderTable[] = {
1587   ARM::Q0,  ARM::D1_D2,   ARM::Q1,  ARM::D3_D4,   ARM::Q2,  ARM::D5_D6,
1588   ARM::Q3,  ARM::D7_D8,   ARM::Q4,  ARM::D9_D10,  ARM::Q5,  ARM::D11_D12,
1589   ARM::Q6,  ARM::D13_D14, ARM::Q7,  ARM::D15_D16, ARM::Q8,  ARM::D17_D18,
1590   ARM::Q9,  ARM::D19_D20, ARM::Q10, ARM::D21_D22, ARM::Q11, ARM::D23_D24,
1591   ARM::Q12, ARM::D25_D26, ARM::Q13, ARM::D27_D28, ARM::Q14, ARM::D29_D30,
1592   ARM::Q15
1593 };
1594 
1595 static DecodeStatus DecodeDPairRegisterClass(MCInst &Inst, unsigned RegNo,
1596                                              uint64_t Address,
1597                                              const MCDisassembler *Decoder) {
1598   if (RegNo > 30)
1599     return MCDisassembler::Fail;
1600 
1601   unsigned Register = DPairDecoderTable[RegNo];
1602   Inst.addOperand(MCOperand::createReg(Register));
1603   return MCDisassembler::Success;
1604 }
1605 
1606 static const uint16_t DPairSpacedDecoderTable[] = {
1607   ARM::D0_D2,   ARM::D1_D3,   ARM::D2_D4,   ARM::D3_D5,
1608   ARM::D4_D6,   ARM::D5_D7,   ARM::D6_D8,   ARM::D7_D9,
1609   ARM::D8_D10,  ARM::D9_D11,  ARM::D10_D12, ARM::D11_D13,
1610   ARM::D12_D14, ARM::D13_D15, ARM::D14_D16, ARM::D15_D17,
1611   ARM::D16_D18, ARM::D17_D19, ARM::D18_D20, ARM::D19_D21,
1612   ARM::D20_D22, ARM::D21_D23, ARM::D22_D24, ARM::D23_D25,
1613   ARM::D24_D26, ARM::D25_D27, ARM::D26_D28, ARM::D27_D29,
1614   ARM::D28_D30, ARM::D29_D31
1615 };
1616 
1617 static DecodeStatus
1618 DecodeDPairSpacedRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Address,
1619                                const MCDisassembler *Decoder) {
1620   if (RegNo > 29)
1621     return MCDisassembler::Fail;
1622 
1623   unsigned Register = DPairSpacedDecoderTable[RegNo];
1624   Inst.addOperand(MCOperand::createReg(Register));
1625   return MCDisassembler::Success;
1626 }
1627 
1628 static DecodeStatus DecodePredicateOperand(MCInst &Inst, unsigned Val,
1629                                            uint64_t Address,
1630                                            const MCDisassembler *Decoder) {
1631   DecodeStatus S = MCDisassembler::Success;
1632   if (Val == 0xF) return MCDisassembler::Fail;
1633   // AL predicate is not allowed on Thumb1 branches.
1634   if (Inst.getOpcode() == ARM::tBcc && Val == 0xE)
1635     return MCDisassembler::Fail;
1636   if (Val != ARMCC::AL && !ARMInsts[Inst.getOpcode()].isPredicable())
1637     Check(S, MCDisassembler::SoftFail);
1638   Inst.addOperand(MCOperand::createImm(Val));
1639   if (Val == ARMCC::AL) {
1640     Inst.addOperand(MCOperand::createReg(0));
1641   } else
1642     Inst.addOperand(MCOperand::createReg(ARM::CPSR));
1643   return S;
1644 }
1645 
1646 static DecodeStatus DecodeCCOutOperand(MCInst &Inst, unsigned Val,
1647                                        uint64_t Address,
1648                                        const MCDisassembler *Decoder) {
1649   if (Val)
1650     Inst.addOperand(MCOperand::createReg(ARM::CPSR));
1651   else
1652     Inst.addOperand(MCOperand::createReg(0));
1653   return MCDisassembler::Success;
1654 }
1655 
1656 static DecodeStatus DecodeSORegImmOperand(MCInst &Inst, unsigned Val,
1657                                           uint64_t Address,
1658                                           const MCDisassembler *Decoder) {
1659   DecodeStatus S = MCDisassembler::Success;
1660 
1661   unsigned Rm = fieldFromInstruction(Val, 0, 4);
1662   unsigned type = fieldFromInstruction(Val, 5, 2);
1663   unsigned imm = fieldFromInstruction(Val, 7, 5);
1664 
1665   // Register-immediate
1666   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
1667     return MCDisassembler::Fail;
1668 
1669   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1670   switch (type) {
1671     case 0:
1672       Shift = ARM_AM::lsl;
1673       break;
1674     case 1:
1675       Shift = ARM_AM::lsr;
1676       break;
1677     case 2:
1678       Shift = ARM_AM::asr;
1679       break;
1680     case 3:
1681       Shift = ARM_AM::ror;
1682       break;
1683   }
1684 
1685   if (Shift == ARM_AM::ror && imm == 0)
1686     Shift = ARM_AM::rrx;
1687 
1688   unsigned Op = Shift | (imm << 3);
1689   Inst.addOperand(MCOperand::createImm(Op));
1690 
1691   return S;
1692 }
1693 
1694 static DecodeStatus DecodeSORegRegOperand(MCInst &Inst, unsigned Val,
1695                                           uint64_t Address,
1696                                           const MCDisassembler *Decoder) {
1697   DecodeStatus S = MCDisassembler::Success;
1698 
1699   unsigned Rm = fieldFromInstruction(Val, 0, 4);
1700   unsigned type = fieldFromInstruction(Val, 5, 2);
1701   unsigned Rs = fieldFromInstruction(Val, 8, 4);
1702 
1703   // Register-register
1704   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1705     return MCDisassembler::Fail;
1706   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rs, Address, Decoder)))
1707     return MCDisassembler::Fail;
1708 
1709   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1710   switch (type) {
1711     case 0:
1712       Shift = ARM_AM::lsl;
1713       break;
1714     case 1:
1715       Shift = ARM_AM::lsr;
1716       break;
1717     case 2:
1718       Shift = ARM_AM::asr;
1719       break;
1720     case 3:
1721       Shift = ARM_AM::ror;
1722       break;
1723   }
1724 
1725   Inst.addOperand(MCOperand::createImm(Shift));
1726 
1727   return S;
1728 }
1729 
1730 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Val,
1731                                          uint64_t Address,
1732                                          const MCDisassembler *Decoder) {
1733   DecodeStatus S = MCDisassembler::Success;
1734 
1735   bool NeedDisjointWriteback = false;
1736   unsigned WritebackReg = 0;
1737   bool CLRM = false;
1738   switch (Inst.getOpcode()) {
1739   default:
1740     break;
1741   case ARM::LDMIA_UPD:
1742   case ARM::LDMDB_UPD:
1743   case ARM::LDMIB_UPD:
1744   case ARM::LDMDA_UPD:
1745   case ARM::t2LDMIA_UPD:
1746   case ARM::t2LDMDB_UPD:
1747   case ARM::t2STMIA_UPD:
1748   case ARM::t2STMDB_UPD:
1749     NeedDisjointWriteback = true;
1750     WritebackReg = Inst.getOperand(0).getReg();
1751     break;
1752   case ARM::t2CLRM:
1753     CLRM = true;
1754     break;
1755   }
1756 
1757   // Empty register lists are not allowed.
1758   if (Val == 0) return MCDisassembler::Fail;
1759   for (unsigned i = 0; i < 16; ++i) {
1760     if (Val & (1 << i)) {
1761       if (CLRM) {
1762         if (!Check(S, DecodeCLRMGPRRegisterClass(Inst, i, Address, Decoder))) {
1763           return MCDisassembler::Fail;
1764         }
1765       } else {
1766         if (!Check(S, DecodeGPRRegisterClass(Inst, i, Address, Decoder)))
1767           return MCDisassembler::Fail;
1768         // Writeback not allowed if Rn is in the target list.
1769         if (NeedDisjointWriteback && WritebackReg == Inst.end()[-1].getReg())
1770           Check(S, MCDisassembler::SoftFail);
1771       }
1772     }
1773   }
1774 
1775   return S;
1776 }
1777 
1778 static DecodeStatus DecodeSPRRegListOperand(MCInst &Inst, unsigned Val,
1779                                             uint64_t Address,
1780                                             const MCDisassembler *Decoder) {
1781   DecodeStatus S = MCDisassembler::Success;
1782 
1783   unsigned Vd = fieldFromInstruction(Val, 8, 5);
1784   unsigned regs = fieldFromInstruction(Val, 0, 8);
1785 
1786   // In case of unpredictable encoding, tweak the operands.
1787   if (regs == 0 || (Vd + regs) > 32) {
1788     regs = Vd + regs > 32 ? 32 - Vd : regs;
1789     regs = std::max( 1u, regs);
1790     S = MCDisassembler::SoftFail;
1791   }
1792 
1793   if (!Check(S, DecodeSPRRegisterClass(Inst, Vd, Address, Decoder)))
1794     return MCDisassembler::Fail;
1795   for (unsigned i = 0; i < (regs - 1); ++i) {
1796     if (!Check(S, DecodeSPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1797       return MCDisassembler::Fail;
1798   }
1799 
1800   return S;
1801 }
1802 
1803 static DecodeStatus DecodeDPRRegListOperand(MCInst &Inst, unsigned Val,
1804                                             uint64_t Address,
1805                                             const MCDisassembler *Decoder) {
1806   DecodeStatus S = MCDisassembler::Success;
1807 
1808   unsigned Vd = fieldFromInstruction(Val, 8, 5);
1809   unsigned regs = fieldFromInstruction(Val, 1, 7);
1810 
1811   // In case of unpredictable encoding, tweak the operands.
1812   if (regs == 0 || regs > 16 || (Vd + regs) > 32) {
1813     regs = Vd + regs > 32 ? 32 - Vd : regs;
1814     regs = std::max( 1u, regs);
1815     regs = std::min(16u, regs);
1816     S = MCDisassembler::SoftFail;
1817   }
1818 
1819   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
1820       return MCDisassembler::Fail;
1821   for (unsigned i = 0; i < (regs - 1); ++i) {
1822     if (!Check(S, DecodeDPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1823       return MCDisassembler::Fail;
1824   }
1825 
1826   return S;
1827 }
1828 
1829 static DecodeStatus DecodeBitfieldMaskOperand(MCInst &Inst, unsigned Val,
1830                                               uint64_t Address,
1831                                               const MCDisassembler *Decoder) {
1832   // This operand encodes a mask of contiguous zeros between a specified MSB
1833   // and LSB.  To decode it, we create the mask of all bits MSB-and-lower,
1834   // the mask of all bits LSB-and-lower, and then xor them to create
1835   // the mask of that's all ones on [msb, lsb].  Finally we not it to
1836   // create the final mask.
1837   unsigned msb = fieldFromInstruction(Val, 5, 5);
1838   unsigned lsb = fieldFromInstruction(Val, 0, 5);
1839 
1840   DecodeStatus S = MCDisassembler::Success;
1841   if (lsb > msb) {
1842     Check(S, MCDisassembler::SoftFail);
1843     // The check above will cause the warning for the "potentially undefined
1844     // instruction encoding" but we can't build a bad MCOperand value here
1845     // with a lsb > msb or else printing the MCInst will cause a crash.
1846     lsb = msb;
1847   }
1848 
1849   uint32_t msb_mask = 0xFFFFFFFF;
1850   if (msb != 31) msb_mask = (1U << (msb+1)) - 1;
1851   uint32_t lsb_mask = (1U << lsb) - 1;
1852 
1853   Inst.addOperand(MCOperand::createImm(~(msb_mask ^ lsb_mask)));
1854   return S;
1855 }
1856 
1857 static DecodeStatus DecodeCopMemInstruction(MCInst &Inst, unsigned Insn,
1858                                             uint64_t Address,
1859                                             const MCDisassembler *Decoder) {
1860   DecodeStatus S = MCDisassembler::Success;
1861 
1862   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1863   unsigned CRd = fieldFromInstruction(Insn, 12, 4);
1864   unsigned coproc = fieldFromInstruction(Insn, 8, 4);
1865   unsigned imm = fieldFromInstruction(Insn, 0, 8);
1866   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1867   unsigned U = fieldFromInstruction(Insn, 23, 1);
1868   const FeatureBitset &featureBits =
1869     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1870 
1871   switch (Inst.getOpcode()) {
1872     case ARM::LDC_OFFSET:
1873     case ARM::LDC_PRE:
1874     case ARM::LDC_POST:
1875     case ARM::LDC_OPTION:
1876     case ARM::LDCL_OFFSET:
1877     case ARM::LDCL_PRE:
1878     case ARM::LDCL_POST:
1879     case ARM::LDCL_OPTION:
1880     case ARM::STC_OFFSET:
1881     case ARM::STC_PRE:
1882     case ARM::STC_POST:
1883     case ARM::STC_OPTION:
1884     case ARM::STCL_OFFSET:
1885     case ARM::STCL_PRE:
1886     case ARM::STCL_POST:
1887     case ARM::STCL_OPTION:
1888     case ARM::t2LDC_OFFSET:
1889     case ARM::t2LDC_PRE:
1890     case ARM::t2LDC_POST:
1891     case ARM::t2LDC_OPTION:
1892     case ARM::t2LDCL_OFFSET:
1893     case ARM::t2LDCL_PRE:
1894     case ARM::t2LDCL_POST:
1895     case ARM::t2LDCL_OPTION:
1896     case ARM::t2STC_OFFSET:
1897     case ARM::t2STC_PRE:
1898     case ARM::t2STC_POST:
1899     case ARM::t2STC_OPTION:
1900     case ARM::t2STCL_OFFSET:
1901     case ARM::t2STCL_PRE:
1902     case ARM::t2STCL_POST:
1903     case ARM::t2STCL_OPTION:
1904     case ARM::t2LDC2_OFFSET:
1905     case ARM::t2LDC2L_OFFSET:
1906     case ARM::t2LDC2_PRE:
1907     case ARM::t2LDC2L_PRE:
1908     case ARM::t2STC2_OFFSET:
1909     case ARM::t2STC2L_OFFSET:
1910     case ARM::t2STC2_PRE:
1911     case ARM::t2STC2L_PRE:
1912     case ARM::LDC2_OFFSET:
1913     case ARM::LDC2L_OFFSET:
1914     case ARM::LDC2_PRE:
1915     case ARM::LDC2L_PRE:
1916     case ARM::STC2_OFFSET:
1917     case ARM::STC2L_OFFSET:
1918     case ARM::STC2_PRE:
1919     case ARM::STC2L_PRE:
1920     case ARM::t2LDC2_OPTION:
1921     case ARM::t2STC2_OPTION:
1922     case ARM::t2LDC2_POST:
1923     case ARM::t2LDC2L_POST:
1924     case ARM::t2STC2_POST:
1925     case ARM::t2STC2L_POST:
1926     case ARM::LDC2_POST:
1927     case ARM::LDC2L_POST:
1928     case ARM::STC2_POST:
1929     case ARM::STC2L_POST:
1930       if (coproc == 0xA || coproc == 0xB ||
1931           (featureBits[ARM::HasV8_1MMainlineOps] &&
1932            (coproc == 0x8 || coproc == 0x9 || coproc == 0xA || coproc == 0xB ||
1933             coproc == 0xE || coproc == 0xF)))
1934         return MCDisassembler::Fail;
1935       break;
1936     default:
1937       break;
1938   }
1939 
1940   if (featureBits[ARM::HasV8Ops] && (coproc != 14))
1941     return MCDisassembler::Fail;
1942 
1943   Inst.addOperand(MCOperand::createImm(coproc));
1944   Inst.addOperand(MCOperand::createImm(CRd));
1945   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1946     return MCDisassembler::Fail;
1947 
1948   switch (Inst.getOpcode()) {
1949     case ARM::t2LDC2_OFFSET:
1950     case ARM::t2LDC2L_OFFSET:
1951     case ARM::t2LDC2_PRE:
1952     case ARM::t2LDC2L_PRE:
1953     case ARM::t2STC2_OFFSET:
1954     case ARM::t2STC2L_OFFSET:
1955     case ARM::t2STC2_PRE:
1956     case ARM::t2STC2L_PRE:
1957     case ARM::LDC2_OFFSET:
1958     case ARM::LDC2L_OFFSET:
1959     case ARM::LDC2_PRE:
1960     case ARM::LDC2L_PRE:
1961     case ARM::STC2_OFFSET:
1962     case ARM::STC2L_OFFSET:
1963     case ARM::STC2_PRE:
1964     case ARM::STC2L_PRE:
1965     case ARM::t2LDC_OFFSET:
1966     case ARM::t2LDCL_OFFSET:
1967     case ARM::t2LDC_PRE:
1968     case ARM::t2LDCL_PRE:
1969     case ARM::t2STC_OFFSET:
1970     case ARM::t2STCL_OFFSET:
1971     case ARM::t2STC_PRE:
1972     case ARM::t2STCL_PRE:
1973     case ARM::LDC_OFFSET:
1974     case ARM::LDCL_OFFSET:
1975     case ARM::LDC_PRE:
1976     case ARM::LDCL_PRE:
1977     case ARM::STC_OFFSET:
1978     case ARM::STCL_OFFSET:
1979     case ARM::STC_PRE:
1980     case ARM::STCL_PRE:
1981       imm = ARM_AM::getAM5Opc(U ? ARM_AM::add : ARM_AM::sub, imm);
1982       Inst.addOperand(MCOperand::createImm(imm));
1983       break;
1984     case ARM::t2LDC2_POST:
1985     case ARM::t2LDC2L_POST:
1986     case ARM::t2STC2_POST:
1987     case ARM::t2STC2L_POST:
1988     case ARM::LDC2_POST:
1989     case ARM::LDC2L_POST:
1990     case ARM::STC2_POST:
1991     case ARM::STC2L_POST:
1992     case ARM::t2LDC_POST:
1993     case ARM::t2LDCL_POST:
1994     case ARM::t2STC_POST:
1995     case ARM::t2STCL_POST:
1996     case ARM::LDC_POST:
1997     case ARM::LDCL_POST:
1998     case ARM::STC_POST:
1999     case ARM::STCL_POST:
2000       imm |= U << 8;
2001       [[fallthrough]];
2002     default:
2003       // The 'option' variant doesn't encode 'U' in the immediate since
2004       // the immediate is unsigned [0,255].
2005       Inst.addOperand(MCOperand::createImm(imm));
2006       break;
2007   }
2008 
2009   switch (Inst.getOpcode()) {
2010     case ARM::LDC_OFFSET:
2011     case ARM::LDC_PRE:
2012     case ARM::LDC_POST:
2013     case ARM::LDC_OPTION:
2014     case ARM::LDCL_OFFSET:
2015     case ARM::LDCL_PRE:
2016     case ARM::LDCL_POST:
2017     case ARM::LDCL_OPTION:
2018     case ARM::STC_OFFSET:
2019     case ARM::STC_PRE:
2020     case ARM::STC_POST:
2021     case ARM::STC_OPTION:
2022     case ARM::STCL_OFFSET:
2023     case ARM::STCL_PRE:
2024     case ARM::STCL_POST:
2025     case ARM::STCL_OPTION:
2026       if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2027         return MCDisassembler::Fail;
2028       break;
2029     default:
2030       break;
2031   }
2032 
2033   return S;
2034 }
2035 
2036 static DecodeStatus
2037 DecodeAddrMode2IdxInstruction(MCInst &Inst, unsigned Insn, uint64_t Address,
2038                               const MCDisassembler *Decoder) {
2039   DecodeStatus S = MCDisassembler::Success;
2040 
2041   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2042   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
2043   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2044   unsigned imm = fieldFromInstruction(Insn, 0, 12);
2045   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2046   unsigned reg = fieldFromInstruction(Insn, 25, 1);
2047   unsigned P = fieldFromInstruction(Insn, 24, 1);
2048   unsigned W = fieldFromInstruction(Insn, 21, 1);
2049 
2050   // On stores, the writeback operand precedes Rt.
2051   switch (Inst.getOpcode()) {
2052     case ARM::STR_POST_IMM:
2053     case ARM::STR_POST_REG:
2054     case ARM::STRB_POST_IMM:
2055     case ARM::STRB_POST_REG:
2056     case ARM::STRT_POST_REG:
2057     case ARM::STRT_POST_IMM:
2058     case ARM::STRBT_POST_REG:
2059     case ARM::STRBT_POST_IMM:
2060       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2061         return MCDisassembler::Fail;
2062       break;
2063     default:
2064       break;
2065   }
2066 
2067   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
2068     return MCDisassembler::Fail;
2069 
2070   // On loads, the writeback operand comes after Rt.
2071   switch (Inst.getOpcode()) {
2072     case ARM::LDR_POST_IMM:
2073     case ARM::LDR_POST_REG:
2074     case ARM::LDRB_POST_IMM:
2075     case ARM::LDRB_POST_REG:
2076     case ARM::LDRBT_POST_REG:
2077     case ARM::LDRBT_POST_IMM:
2078     case ARM::LDRT_POST_REG:
2079     case ARM::LDRT_POST_IMM:
2080       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2081         return MCDisassembler::Fail;
2082       break;
2083     default:
2084       break;
2085   }
2086 
2087   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2088     return MCDisassembler::Fail;
2089 
2090   ARM_AM::AddrOpc Op = ARM_AM::add;
2091   if (!fieldFromInstruction(Insn, 23, 1))
2092     Op = ARM_AM::sub;
2093 
2094   bool writeback = (P == 0) || (W == 1);
2095   unsigned idx_mode = 0;
2096   if (P && writeback)
2097     idx_mode = ARMII::IndexModePre;
2098   else if (!P && writeback)
2099     idx_mode = ARMII::IndexModePost;
2100 
2101   if (writeback && (Rn == 15 || Rn == Rt))
2102     S = MCDisassembler::SoftFail; // UNPREDICTABLE
2103 
2104   if (reg) {
2105     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
2106       return MCDisassembler::Fail;
2107     ARM_AM::ShiftOpc Opc = ARM_AM::lsl;
2108     switch( fieldFromInstruction(Insn, 5, 2)) {
2109       case 0:
2110         Opc = ARM_AM::lsl;
2111         break;
2112       case 1:
2113         Opc = ARM_AM::lsr;
2114         break;
2115       case 2:
2116         Opc = ARM_AM::asr;
2117         break;
2118       case 3:
2119         Opc = ARM_AM::ror;
2120         break;
2121       default:
2122         return MCDisassembler::Fail;
2123     }
2124     unsigned amt = fieldFromInstruction(Insn, 7, 5);
2125     if (Opc == ARM_AM::ror && amt == 0)
2126       Opc = ARM_AM::rrx;
2127     unsigned imm = ARM_AM::getAM2Opc(Op, amt, Opc, idx_mode);
2128 
2129     Inst.addOperand(MCOperand::createImm(imm));
2130   } else {
2131     Inst.addOperand(MCOperand::createReg(0));
2132     unsigned tmp = ARM_AM::getAM2Opc(Op, imm, ARM_AM::lsl, idx_mode);
2133     Inst.addOperand(MCOperand::createImm(tmp));
2134   }
2135 
2136   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2137     return MCDisassembler::Fail;
2138 
2139   return S;
2140 }
2141 
2142 static DecodeStatus DecodeSORegMemOperand(MCInst &Inst, unsigned Val,
2143                                           uint64_t Address,
2144                                           const MCDisassembler *Decoder) {
2145   DecodeStatus S = MCDisassembler::Success;
2146 
2147   unsigned Rn = fieldFromInstruction(Val, 13, 4);
2148   unsigned Rm = fieldFromInstruction(Val,  0, 4);
2149   unsigned type = fieldFromInstruction(Val, 5, 2);
2150   unsigned imm = fieldFromInstruction(Val, 7, 5);
2151   unsigned U = fieldFromInstruction(Val, 12, 1);
2152 
2153   ARM_AM::ShiftOpc ShOp = ARM_AM::lsl;
2154   switch (type) {
2155     case 0:
2156       ShOp = ARM_AM::lsl;
2157       break;
2158     case 1:
2159       ShOp = ARM_AM::lsr;
2160       break;
2161     case 2:
2162       ShOp = ARM_AM::asr;
2163       break;
2164     case 3:
2165       ShOp = ARM_AM::ror;
2166       break;
2167   }
2168 
2169   if (ShOp == ARM_AM::ror && imm == 0)
2170     ShOp = ARM_AM::rrx;
2171 
2172   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2173     return MCDisassembler::Fail;
2174   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2175     return MCDisassembler::Fail;
2176   unsigned shift;
2177   if (U)
2178     shift = ARM_AM::getAM2Opc(ARM_AM::add, imm, ShOp);
2179   else
2180     shift = ARM_AM::getAM2Opc(ARM_AM::sub, imm, ShOp);
2181   Inst.addOperand(MCOperand::createImm(shift));
2182 
2183   return S;
2184 }
2185 
2186 static DecodeStatus DecodeTSBInstruction(MCInst &Inst, unsigned Insn,
2187                                          uint64_t Address,
2188                                          const MCDisassembler *Decoder) {
2189   if (Inst.getOpcode() != ARM::TSB && Inst.getOpcode() != ARM::t2TSB)
2190     return MCDisassembler::Fail;
2191 
2192   // The "csync" operand is not encoded into the "tsb" instruction (as this is
2193   // the only available operand), but LLVM expects the instruction to have one
2194   // operand, so we need to add the csync when decoding.
2195   Inst.addOperand(MCOperand::createImm(ARM_TSB::CSYNC));
2196   return MCDisassembler::Success;
2197 }
2198 
2199 static DecodeStatus DecodeAddrMode3Instruction(MCInst &Inst, unsigned Insn,
2200                                                uint64_t Address,
2201                                                const MCDisassembler *Decoder) {
2202   DecodeStatus S = MCDisassembler::Success;
2203 
2204   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
2205   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2206   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2207   unsigned type = fieldFromInstruction(Insn, 22, 1);
2208   unsigned imm = fieldFromInstruction(Insn, 8, 4);
2209   unsigned U = ((~fieldFromInstruction(Insn, 23, 1)) & 1) << 8;
2210   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2211   unsigned W = fieldFromInstruction(Insn, 21, 1);
2212   unsigned P = fieldFromInstruction(Insn, 24, 1);
2213   unsigned Rt2 = Rt + 1;
2214 
2215   bool writeback = (W == 1) | (P == 0);
2216 
2217   // For {LD,ST}RD, Rt must be even, else undefined.
2218   switch (Inst.getOpcode()) {
2219     case ARM::STRD:
2220     case ARM::STRD_PRE:
2221     case ARM::STRD_POST:
2222     case ARM::LDRD:
2223     case ARM::LDRD_PRE:
2224     case ARM::LDRD_POST:
2225       if (Rt & 0x1) S = MCDisassembler::SoftFail;
2226       break;
2227     default:
2228       break;
2229   }
2230   switch (Inst.getOpcode()) {
2231     case ARM::STRD:
2232     case ARM::STRD_PRE:
2233     case ARM::STRD_POST:
2234       if (P == 0 && W == 1)
2235         S = MCDisassembler::SoftFail;
2236 
2237       if (writeback && (Rn == 15 || Rn == Rt || Rn == Rt2))
2238         S = MCDisassembler::SoftFail;
2239       if (type && Rm == 15)
2240         S = MCDisassembler::SoftFail;
2241       if (Rt2 == 15)
2242         S = MCDisassembler::SoftFail;
2243       if (!type && fieldFromInstruction(Insn, 8, 4))
2244         S = MCDisassembler::SoftFail;
2245       break;
2246     case ARM::STRH:
2247     case ARM::STRH_PRE:
2248     case ARM::STRH_POST:
2249       if (Rt == 15)
2250         S = MCDisassembler::SoftFail;
2251       if (writeback && (Rn == 15 || Rn == Rt))
2252         S = MCDisassembler::SoftFail;
2253       if (!type && Rm == 15)
2254         S = MCDisassembler::SoftFail;
2255       break;
2256     case ARM::LDRD:
2257     case ARM::LDRD_PRE:
2258     case ARM::LDRD_POST:
2259       if (type && Rn == 15) {
2260         if (Rt2 == 15)
2261           S = MCDisassembler::SoftFail;
2262         break;
2263       }
2264       if (P == 0 && W == 1)
2265         S = MCDisassembler::SoftFail;
2266       if (!type && (Rt2 == 15 || Rm == 15 || Rm == Rt || Rm == Rt2))
2267         S = MCDisassembler::SoftFail;
2268       if (!type && writeback && Rn == 15)
2269         S = MCDisassembler::SoftFail;
2270       if (writeback && (Rn == Rt || Rn == Rt2))
2271         S = MCDisassembler::SoftFail;
2272       break;
2273     case ARM::LDRH:
2274     case ARM::LDRH_PRE:
2275     case ARM::LDRH_POST:
2276       if (type && Rn == 15) {
2277         if (Rt == 15)
2278           S = MCDisassembler::SoftFail;
2279         break;
2280       }
2281       if (Rt == 15)
2282         S = MCDisassembler::SoftFail;
2283       if (!type && Rm == 15)
2284         S = MCDisassembler::SoftFail;
2285       if (!type && writeback && (Rn == 15 || Rn == Rt))
2286         S = MCDisassembler::SoftFail;
2287       break;
2288     case ARM::LDRSH:
2289     case ARM::LDRSH_PRE:
2290     case ARM::LDRSH_POST:
2291     case ARM::LDRSB:
2292     case ARM::LDRSB_PRE:
2293     case ARM::LDRSB_POST:
2294       if (type && Rn == 15) {
2295         if (Rt == 15)
2296           S = MCDisassembler::SoftFail;
2297         break;
2298       }
2299       if (type && (Rt == 15 || (writeback && Rn == Rt)))
2300         S = MCDisassembler::SoftFail;
2301       if (!type && (Rt == 15 || Rm == 15))
2302         S = MCDisassembler::SoftFail;
2303       if (!type && writeback && (Rn == 15 || Rn == Rt))
2304         S = MCDisassembler::SoftFail;
2305       break;
2306     default:
2307       break;
2308   }
2309 
2310   if (writeback) { // Writeback
2311     if (P)
2312       U |= ARMII::IndexModePre << 9;
2313     else
2314       U |= ARMII::IndexModePost << 9;
2315 
2316     // On stores, the writeback operand precedes Rt.
2317     switch (Inst.getOpcode()) {
2318     case ARM::STRD:
2319     case ARM::STRD_PRE:
2320     case ARM::STRD_POST:
2321     case ARM::STRH:
2322     case ARM::STRH_PRE:
2323     case ARM::STRH_POST:
2324       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2325         return MCDisassembler::Fail;
2326       break;
2327     default:
2328       break;
2329     }
2330   }
2331 
2332   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
2333     return MCDisassembler::Fail;
2334   switch (Inst.getOpcode()) {
2335     case ARM::STRD:
2336     case ARM::STRD_PRE:
2337     case ARM::STRD_POST:
2338     case ARM::LDRD:
2339     case ARM::LDRD_PRE:
2340     case ARM::LDRD_POST:
2341       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder)))
2342         return MCDisassembler::Fail;
2343       break;
2344     default:
2345       break;
2346   }
2347 
2348   if (writeback) {
2349     // On loads, the writeback operand comes after Rt.
2350     switch (Inst.getOpcode()) {
2351     case ARM::LDRD:
2352     case ARM::LDRD_PRE:
2353     case ARM::LDRD_POST:
2354     case ARM::LDRH:
2355     case ARM::LDRH_PRE:
2356     case ARM::LDRH_POST:
2357     case ARM::LDRSH:
2358     case ARM::LDRSH_PRE:
2359     case ARM::LDRSH_POST:
2360     case ARM::LDRSB:
2361     case ARM::LDRSB_PRE:
2362     case ARM::LDRSB_POST:
2363     case ARM::LDRHTr:
2364     case ARM::LDRSBTr:
2365       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2366         return MCDisassembler::Fail;
2367       break;
2368     default:
2369       break;
2370     }
2371   }
2372 
2373   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2374     return MCDisassembler::Fail;
2375 
2376   if (type) {
2377     Inst.addOperand(MCOperand::createReg(0));
2378     Inst.addOperand(MCOperand::createImm(U | (imm << 4) | Rm));
2379   } else {
2380     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2381     return MCDisassembler::Fail;
2382     Inst.addOperand(MCOperand::createImm(U));
2383   }
2384 
2385   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2386     return MCDisassembler::Fail;
2387 
2388   return S;
2389 }
2390 
2391 static DecodeStatus DecodeRFEInstruction(MCInst &Inst, unsigned Insn,
2392                                          uint64_t Address,
2393                                          const MCDisassembler *Decoder) {
2394   DecodeStatus S = MCDisassembler::Success;
2395 
2396   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2397   unsigned mode = fieldFromInstruction(Insn, 23, 2);
2398 
2399   switch (mode) {
2400     case 0:
2401       mode = ARM_AM::da;
2402       break;
2403     case 1:
2404       mode = ARM_AM::ia;
2405       break;
2406     case 2:
2407       mode = ARM_AM::db;
2408       break;
2409     case 3:
2410       mode = ARM_AM::ib;
2411       break;
2412   }
2413 
2414   Inst.addOperand(MCOperand::createImm(mode));
2415   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2416     return MCDisassembler::Fail;
2417 
2418   return S;
2419 }
2420 
2421 static DecodeStatus DecodeQADDInstruction(MCInst &Inst, unsigned Insn,
2422                                           uint64_t Address,
2423                                           const MCDisassembler *Decoder) {
2424   DecodeStatus S = MCDisassembler::Success;
2425 
2426   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2427   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2428   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2429   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2430 
2431   if (pred == 0xF)
2432     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
2433 
2434   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2435     return MCDisassembler::Fail;
2436   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
2437     return MCDisassembler::Fail;
2438   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
2439     return MCDisassembler::Fail;
2440   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2441     return MCDisassembler::Fail;
2442   return S;
2443 }
2444 
2445 static DecodeStatus
2446 DecodeMemMultipleWritebackInstruction(MCInst &Inst, unsigned Insn,
2447                                       uint64_t Address,
2448                                       const MCDisassembler *Decoder) {
2449   DecodeStatus S = MCDisassembler::Success;
2450 
2451   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2452   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2453   unsigned reglist = fieldFromInstruction(Insn, 0, 16);
2454 
2455   if (pred == 0xF) {
2456     // Ambiguous with RFE and SRS
2457     switch (Inst.getOpcode()) {
2458       case ARM::LDMDA:
2459         Inst.setOpcode(ARM::RFEDA);
2460         break;
2461       case ARM::LDMDA_UPD:
2462         Inst.setOpcode(ARM::RFEDA_UPD);
2463         break;
2464       case ARM::LDMDB:
2465         Inst.setOpcode(ARM::RFEDB);
2466         break;
2467       case ARM::LDMDB_UPD:
2468         Inst.setOpcode(ARM::RFEDB_UPD);
2469         break;
2470       case ARM::LDMIA:
2471         Inst.setOpcode(ARM::RFEIA);
2472         break;
2473       case ARM::LDMIA_UPD:
2474         Inst.setOpcode(ARM::RFEIA_UPD);
2475         break;
2476       case ARM::LDMIB:
2477         Inst.setOpcode(ARM::RFEIB);
2478         break;
2479       case ARM::LDMIB_UPD:
2480         Inst.setOpcode(ARM::RFEIB_UPD);
2481         break;
2482       case ARM::STMDA:
2483         Inst.setOpcode(ARM::SRSDA);
2484         break;
2485       case ARM::STMDA_UPD:
2486         Inst.setOpcode(ARM::SRSDA_UPD);
2487         break;
2488       case ARM::STMDB:
2489         Inst.setOpcode(ARM::SRSDB);
2490         break;
2491       case ARM::STMDB_UPD:
2492         Inst.setOpcode(ARM::SRSDB_UPD);
2493         break;
2494       case ARM::STMIA:
2495         Inst.setOpcode(ARM::SRSIA);
2496         break;
2497       case ARM::STMIA_UPD:
2498         Inst.setOpcode(ARM::SRSIA_UPD);
2499         break;
2500       case ARM::STMIB:
2501         Inst.setOpcode(ARM::SRSIB);
2502         break;
2503       case ARM::STMIB_UPD:
2504         Inst.setOpcode(ARM::SRSIB_UPD);
2505         break;
2506       default:
2507         return MCDisassembler::Fail;
2508     }
2509 
2510     // For stores (which become SRS's, the only operand is the mode.
2511     if (fieldFromInstruction(Insn, 20, 1) == 0) {
2512       // Check SRS encoding constraints
2513       if (!(fieldFromInstruction(Insn, 22, 1) == 1 &&
2514             fieldFromInstruction(Insn, 20, 1) == 0))
2515         return MCDisassembler::Fail;
2516 
2517       Inst.addOperand(
2518           MCOperand::createImm(fieldFromInstruction(Insn, 0, 4)));
2519       return S;
2520     }
2521 
2522     return DecodeRFEInstruction(Inst, Insn, Address, Decoder);
2523   }
2524 
2525   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2526     return MCDisassembler::Fail;
2527   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2528     return MCDisassembler::Fail; // Tied
2529   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2530     return MCDisassembler::Fail;
2531   if (!Check(S, DecodeRegListOperand(Inst, reglist, Address, Decoder)))
2532     return MCDisassembler::Fail;
2533 
2534   return S;
2535 }
2536 
2537 // Check for UNPREDICTABLE predicated ESB instruction
2538 static DecodeStatus DecodeHINTInstruction(MCInst &Inst, unsigned Insn,
2539                                           uint64_t Address,
2540                                           const MCDisassembler *Decoder) {
2541   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2542   unsigned imm8 = fieldFromInstruction(Insn, 0, 8);
2543   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
2544   const FeatureBitset &FeatureBits = Dis->getSubtargetInfo().getFeatureBits();
2545 
2546   DecodeStatus S = MCDisassembler::Success;
2547 
2548   Inst.addOperand(MCOperand::createImm(imm8));
2549 
2550   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2551     return MCDisassembler::Fail;
2552 
2553   // ESB is unpredictable if pred != AL. Without the RAS extension, it is a NOP,
2554   // so all predicates should be allowed.
2555   if (imm8 == 0x10 && pred != 0xe && ((FeatureBits[ARM::FeatureRAS]) != 0))
2556     S = MCDisassembler::SoftFail;
2557 
2558   return S;
2559 }
2560 
2561 static DecodeStatus DecodeCPSInstruction(MCInst &Inst, unsigned Insn,
2562                                          uint64_t Address,
2563                                          const MCDisassembler *Decoder) {
2564   unsigned imod = fieldFromInstruction(Insn, 18, 2);
2565   unsigned M = fieldFromInstruction(Insn, 17, 1);
2566   unsigned iflags = fieldFromInstruction(Insn, 6, 3);
2567   unsigned mode = fieldFromInstruction(Insn, 0, 5);
2568 
2569   DecodeStatus S = MCDisassembler::Success;
2570 
2571   // This decoder is called from multiple location that do not check
2572   // the full encoding is valid before they do.
2573   if (fieldFromInstruction(Insn, 5, 1) != 0 ||
2574       fieldFromInstruction(Insn, 16, 1) != 0 ||
2575       fieldFromInstruction(Insn, 20, 8) != 0x10)
2576     return MCDisassembler::Fail;
2577 
2578   // imod == '01' --> UNPREDICTABLE
2579   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
2580   // return failure here.  The '01' imod value is unprintable, so there's
2581   // nothing useful we could do even if we returned UNPREDICTABLE.
2582 
2583   if (imod == 1) return MCDisassembler::Fail;
2584 
2585   if (imod && M) {
2586     Inst.setOpcode(ARM::CPS3p);
2587     Inst.addOperand(MCOperand::createImm(imod));
2588     Inst.addOperand(MCOperand::createImm(iflags));
2589     Inst.addOperand(MCOperand::createImm(mode));
2590   } else if (imod && !M) {
2591     Inst.setOpcode(ARM::CPS2p);
2592     Inst.addOperand(MCOperand::createImm(imod));
2593     Inst.addOperand(MCOperand::createImm(iflags));
2594     if (mode) S = MCDisassembler::SoftFail;
2595   } else if (!imod && M) {
2596     Inst.setOpcode(ARM::CPS1p);
2597     Inst.addOperand(MCOperand::createImm(mode));
2598     if (iflags) S = MCDisassembler::SoftFail;
2599   } else {
2600     // imod == '00' && M == '0' --> UNPREDICTABLE
2601     Inst.setOpcode(ARM::CPS1p);
2602     Inst.addOperand(MCOperand::createImm(mode));
2603     S = MCDisassembler::SoftFail;
2604   }
2605 
2606   return S;
2607 }
2608 
2609 static DecodeStatus DecodeT2CPSInstruction(MCInst &Inst, unsigned Insn,
2610                                            uint64_t Address,
2611                                            const MCDisassembler *Decoder) {
2612   unsigned imod = fieldFromInstruction(Insn, 9, 2);
2613   unsigned M = fieldFromInstruction(Insn, 8, 1);
2614   unsigned iflags = fieldFromInstruction(Insn, 5, 3);
2615   unsigned mode = fieldFromInstruction(Insn, 0, 5);
2616 
2617   DecodeStatus S = MCDisassembler::Success;
2618 
2619   // imod == '01' --> UNPREDICTABLE
2620   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
2621   // return failure here.  The '01' imod value is unprintable, so there's
2622   // nothing useful we could do even if we returned UNPREDICTABLE.
2623 
2624   if (imod == 1) return MCDisassembler::Fail;
2625 
2626   if (imod && M) {
2627     Inst.setOpcode(ARM::t2CPS3p);
2628     Inst.addOperand(MCOperand::createImm(imod));
2629     Inst.addOperand(MCOperand::createImm(iflags));
2630     Inst.addOperand(MCOperand::createImm(mode));
2631   } else if (imod && !M) {
2632     Inst.setOpcode(ARM::t2CPS2p);
2633     Inst.addOperand(MCOperand::createImm(imod));
2634     Inst.addOperand(MCOperand::createImm(iflags));
2635     if (mode) S = MCDisassembler::SoftFail;
2636   } else if (!imod && M) {
2637     Inst.setOpcode(ARM::t2CPS1p);
2638     Inst.addOperand(MCOperand::createImm(mode));
2639     if (iflags) S = MCDisassembler::SoftFail;
2640   } else {
2641     // imod == '00' && M == '0' --> this is a HINT instruction
2642     int imm = fieldFromInstruction(Insn, 0, 8);
2643     // HINT are defined only for immediate in [0..4]
2644     if(imm > 4) return MCDisassembler::Fail;
2645     Inst.setOpcode(ARM::t2HINT);
2646     Inst.addOperand(MCOperand::createImm(imm));
2647   }
2648 
2649   return S;
2650 }
2651 
2652 static DecodeStatus
2653 DecodeT2HintSpaceInstruction(MCInst &Inst, unsigned Insn, uint64_t Address,
2654                              const MCDisassembler *Decoder) {
2655   unsigned imm = fieldFromInstruction(Insn, 0, 8);
2656 
2657   unsigned Opcode = ARM::t2HINT;
2658 
2659   if (imm == 0x0D) {
2660     Opcode = ARM::t2PACBTI;
2661   } else if (imm == 0x1D) {
2662     Opcode = ARM::t2PAC;
2663   } else if (imm == 0x2D) {
2664     Opcode = ARM::t2AUT;
2665   } else if (imm == 0x0F) {
2666     Opcode = ARM::t2BTI;
2667   }
2668 
2669   Inst.setOpcode(Opcode);
2670   if (Opcode == ARM::t2HINT) {
2671     Inst.addOperand(MCOperand::createImm(imm));
2672   }
2673 
2674   return MCDisassembler::Success;
2675 }
2676 
2677 static DecodeStatus DecodeT2MOVTWInstruction(MCInst &Inst, unsigned Insn,
2678                                              uint64_t Address,
2679                                              const MCDisassembler *Decoder) {
2680   DecodeStatus S = MCDisassembler::Success;
2681 
2682   unsigned Rd = fieldFromInstruction(Insn, 8, 4);
2683   unsigned imm = 0;
2684 
2685   imm |= (fieldFromInstruction(Insn, 0, 8) << 0);
2686   imm |= (fieldFromInstruction(Insn, 12, 3) << 8);
2687   imm |= (fieldFromInstruction(Insn, 16, 4) << 12);
2688   imm |= (fieldFromInstruction(Insn, 26, 1) << 11);
2689 
2690   if (Inst.getOpcode() == ARM::t2MOVTi16)
2691     if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
2692       return MCDisassembler::Fail;
2693   if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
2694     return MCDisassembler::Fail;
2695 
2696   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
2697     Inst.addOperand(MCOperand::createImm(imm));
2698 
2699   return S;
2700 }
2701 
2702 static DecodeStatus DecodeArmMOVTWInstruction(MCInst &Inst, unsigned Insn,
2703                                               uint64_t Address,
2704                                               const MCDisassembler *Decoder) {
2705   DecodeStatus S = MCDisassembler::Success;
2706 
2707   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2708   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2709   unsigned imm = 0;
2710 
2711   imm |= (fieldFromInstruction(Insn, 0, 12) << 0);
2712   imm |= (fieldFromInstruction(Insn, 16, 4) << 12);
2713 
2714   if (Inst.getOpcode() == ARM::MOVTi16)
2715     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2716       return MCDisassembler::Fail;
2717 
2718   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2719     return MCDisassembler::Fail;
2720 
2721   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
2722     Inst.addOperand(MCOperand::createImm(imm));
2723 
2724   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2725     return MCDisassembler::Fail;
2726 
2727   return S;
2728 }
2729 
2730 static DecodeStatus DecodeSMLAInstruction(MCInst &Inst, unsigned Insn,
2731                                           uint64_t Address,
2732                                           const MCDisassembler *Decoder) {
2733   DecodeStatus S = MCDisassembler::Success;
2734 
2735   unsigned Rd = fieldFromInstruction(Insn, 16, 4);
2736   unsigned Rn = fieldFromInstruction(Insn, 0, 4);
2737   unsigned Rm = fieldFromInstruction(Insn, 8, 4);
2738   unsigned Ra = fieldFromInstruction(Insn, 12, 4);
2739   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2740 
2741   if (pred == 0xF)
2742     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
2743 
2744   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2745     return MCDisassembler::Fail;
2746   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
2747     return MCDisassembler::Fail;
2748   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
2749     return MCDisassembler::Fail;
2750   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Ra, Address, Decoder)))
2751     return MCDisassembler::Fail;
2752 
2753   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2754     return MCDisassembler::Fail;
2755 
2756   return S;
2757 }
2758 
2759 static DecodeStatus DecodeTSTInstruction(MCInst &Inst, unsigned Insn,
2760                                          uint64_t Address,
2761                                          const MCDisassembler *Decoder) {
2762   DecodeStatus S = MCDisassembler::Success;
2763 
2764   unsigned Pred = fieldFromInstruction(Insn, 28, 4);
2765   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2766   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2767 
2768   if (Pred == 0xF)
2769     return DecodeSETPANInstruction(Inst, Insn, Address, Decoder);
2770 
2771   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2772     return MCDisassembler::Fail;
2773   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2774     return MCDisassembler::Fail;
2775   if (!Check(S, DecodePredicateOperand(Inst, Pred, Address, Decoder)))
2776     return MCDisassembler::Fail;
2777 
2778   return S;
2779 }
2780 
2781 static DecodeStatus DecodeSETPANInstruction(MCInst &Inst, unsigned Insn,
2782                                             uint64_t Address,
2783                                             const MCDisassembler *Decoder) {
2784   DecodeStatus S = MCDisassembler::Success;
2785 
2786   unsigned Imm = fieldFromInstruction(Insn, 9, 1);
2787 
2788   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
2789   const FeatureBitset &FeatureBits = Dis->getSubtargetInfo().getFeatureBits();
2790 
2791   if (!FeatureBits[ARM::HasV8_1aOps] ||
2792       !FeatureBits[ARM::HasV8Ops])
2793     return MCDisassembler::Fail;
2794 
2795   // Decoder can be called from DecodeTST, which does not check the full
2796   // encoding is valid.
2797   if (fieldFromInstruction(Insn, 20,12) != 0xf11 ||
2798       fieldFromInstruction(Insn, 4,4) != 0)
2799     return MCDisassembler::Fail;
2800   if (fieldFromInstruction(Insn, 10,10) != 0 ||
2801       fieldFromInstruction(Insn, 0,4) != 0)
2802     S = MCDisassembler::SoftFail;
2803 
2804   Inst.setOpcode(ARM::SETPAN);
2805   Inst.addOperand(MCOperand::createImm(Imm));
2806 
2807   return S;
2808 }
2809 
2810 static DecodeStatus DecodeAddrModeImm12Operand(MCInst &Inst, unsigned Val,
2811                                                uint64_t Address,
2812                                                const MCDisassembler *Decoder) {
2813   DecodeStatus S = MCDisassembler::Success;
2814 
2815   unsigned add = fieldFromInstruction(Val, 12, 1);
2816   unsigned imm = fieldFromInstruction(Val, 0, 12);
2817   unsigned Rn = fieldFromInstruction(Val, 13, 4);
2818 
2819   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2820     return MCDisassembler::Fail;
2821 
2822   if (!add) imm *= -1;
2823   if (imm == 0 && !add) imm = INT32_MIN;
2824   Inst.addOperand(MCOperand::createImm(imm));
2825   if (Rn == 15)
2826     tryAddingPcLoadReferenceComment(Address, Address + imm + 8, Decoder);
2827 
2828   return S;
2829 }
2830 
2831 static DecodeStatus DecodeAddrMode5Operand(MCInst &Inst, unsigned Val,
2832                                            uint64_t Address,
2833                                            const MCDisassembler *Decoder) {
2834   DecodeStatus S = MCDisassembler::Success;
2835 
2836   unsigned Rn = fieldFromInstruction(Val, 9, 4);
2837   // U == 1 to add imm, 0 to subtract it.
2838   unsigned U = fieldFromInstruction(Val, 8, 1);
2839   unsigned imm = fieldFromInstruction(Val, 0, 8);
2840 
2841   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2842     return MCDisassembler::Fail;
2843 
2844   if (U)
2845     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5Opc(ARM_AM::add, imm)));
2846   else
2847     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5Opc(ARM_AM::sub, imm)));
2848 
2849   return S;
2850 }
2851 
2852 static DecodeStatus DecodeAddrMode5FP16Operand(MCInst &Inst, unsigned Val,
2853                                                uint64_t Address,
2854                                                const MCDisassembler *Decoder) {
2855   DecodeStatus S = MCDisassembler::Success;
2856 
2857   unsigned Rn = fieldFromInstruction(Val, 9, 4);
2858   // U == 1 to add imm, 0 to subtract it.
2859   unsigned U = fieldFromInstruction(Val, 8, 1);
2860   unsigned imm = fieldFromInstruction(Val, 0, 8);
2861 
2862   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2863     return MCDisassembler::Fail;
2864 
2865   if (U)
2866     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5FP16Opc(ARM_AM::add, imm)));
2867   else
2868     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5FP16Opc(ARM_AM::sub, imm)));
2869 
2870   return S;
2871 }
2872 
2873 static DecodeStatus DecodeAddrMode7Operand(MCInst &Inst, unsigned Val,
2874                                            uint64_t Address,
2875                                            const MCDisassembler *Decoder) {
2876   return DecodeGPRRegisterClass(Inst, Val, Address, Decoder);
2877 }
2878 
2879 static DecodeStatus DecodeT2BInstruction(MCInst &Inst, unsigned Insn,
2880                                          uint64_t Address,
2881                                          const MCDisassembler *Decoder) {
2882   DecodeStatus Status = MCDisassembler::Success;
2883 
2884   // Note the J1 and J2 values are from the encoded instruction.  So here
2885   // change them to I1 and I2 values via as documented:
2886   // I1 = NOT(J1 EOR S);
2887   // I2 = NOT(J2 EOR S);
2888   // and build the imm32 with one trailing zero as documented:
2889   // imm32 = SignExtend(S:I1:I2:imm10:imm11:'0', 32);
2890   unsigned S = fieldFromInstruction(Insn, 26, 1);
2891   unsigned J1 = fieldFromInstruction(Insn, 13, 1);
2892   unsigned J2 = fieldFromInstruction(Insn, 11, 1);
2893   unsigned I1 = !(J1 ^ S);
2894   unsigned I2 = !(J2 ^ S);
2895   unsigned imm10 = fieldFromInstruction(Insn, 16, 10);
2896   unsigned imm11 = fieldFromInstruction(Insn, 0, 11);
2897   unsigned tmp = (S << 23) | (I1 << 22) | (I2 << 21) | (imm10 << 11) | imm11;
2898   int imm32 = SignExtend32<25>(tmp << 1);
2899   if (!tryAddingSymbolicOperand(Address, Address + imm32 + 4,
2900                                 true, 4, Inst, Decoder))
2901     Inst.addOperand(MCOperand::createImm(imm32));
2902 
2903   return Status;
2904 }
2905 
2906 static DecodeStatus DecodeBranchImmInstruction(MCInst &Inst, unsigned Insn,
2907                                                uint64_t Address,
2908                                                const MCDisassembler *Decoder) {
2909   DecodeStatus S = MCDisassembler::Success;
2910 
2911   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2912   unsigned imm = fieldFromInstruction(Insn, 0, 24) << 2;
2913 
2914   if (pred == 0xF) {
2915     Inst.setOpcode(ARM::BLXi);
2916     imm |= fieldFromInstruction(Insn, 24, 1) << 1;
2917     if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<26>(imm) + 8,
2918                                   true, 4, Inst, Decoder))
2919     Inst.addOperand(MCOperand::createImm(SignExtend32<26>(imm)));
2920     return S;
2921   }
2922 
2923   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<26>(imm) + 8,
2924                                 true, 4, Inst, Decoder))
2925     Inst.addOperand(MCOperand::createImm(SignExtend32<26>(imm)));
2926 
2927   // We already have BL_pred for BL w/ predicate, no need to add addition
2928   // predicate opreands for BL
2929   if (Inst.getOpcode() != ARM::BL)
2930     if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2931       return MCDisassembler::Fail;
2932 
2933   return S;
2934 }
2935 
2936 static DecodeStatus DecodeAddrMode6Operand(MCInst &Inst, unsigned Val,
2937                                            uint64_t Address,
2938                                            const MCDisassembler *Decoder) {
2939   DecodeStatus S = MCDisassembler::Success;
2940 
2941   unsigned Rm = fieldFromInstruction(Val, 0, 4);
2942   unsigned align = fieldFromInstruction(Val, 4, 2);
2943 
2944   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2945     return MCDisassembler::Fail;
2946   if (!align)
2947     Inst.addOperand(MCOperand::createImm(0));
2948   else
2949     Inst.addOperand(MCOperand::createImm(4 << align));
2950 
2951   return S;
2952 }
2953 
2954 static DecodeStatus DecodeVLDInstruction(MCInst &Inst, unsigned Insn,
2955                                          uint64_t Address,
2956                                          const MCDisassembler *Decoder) {
2957   DecodeStatus S = MCDisassembler::Success;
2958 
2959   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2960   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
2961   unsigned wb = fieldFromInstruction(Insn, 16, 4);
2962   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2963   Rn |= fieldFromInstruction(Insn, 4, 2) << 4;
2964   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2965 
2966   // First output register
2967   switch (Inst.getOpcode()) {
2968   case ARM::VLD1q16: case ARM::VLD1q32: case ARM::VLD1q64: case ARM::VLD1q8:
2969   case ARM::VLD1q16wb_fixed: case ARM::VLD1q16wb_register:
2970   case ARM::VLD1q32wb_fixed: case ARM::VLD1q32wb_register:
2971   case ARM::VLD1q64wb_fixed: case ARM::VLD1q64wb_register:
2972   case ARM::VLD1q8wb_fixed: case ARM::VLD1q8wb_register:
2973   case ARM::VLD2d16: case ARM::VLD2d32: case ARM::VLD2d8:
2974   case ARM::VLD2d16wb_fixed: case ARM::VLD2d16wb_register:
2975   case ARM::VLD2d32wb_fixed: case ARM::VLD2d32wb_register:
2976   case ARM::VLD2d8wb_fixed: case ARM::VLD2d8wb_register:
2977     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
2978       return MCDisassembler::Fail;
2979     break;
2980   case ARM::VLD2b16:
2981   case ARM::VLD2b32:
2982   case ARM::VLD2b8:
2983   case ARM::VLD2b16wb_fixed:
2984   case ARM::VLD2b16wb_register:
2985   case ARM::VLD2b32wb_fixed:
2986   case ARM::VLD2b32wb_register:
2987   case ARM::VLD2b8wb_fixed:
2988   case ARM::VLD2b8wb_register:
2989     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
2990       return MCDisassembler::Fail;
2991     break;
2992   default:
2993     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2994       return MCDisassembler::Fail;
2995   }
2996 
2997   // Second output register
2998   switch (Inst.getOpcode()) {
2999     case ARM::VLD3d8:
3000     case ARM::VLD3d16:
3001     case ARM::VLD3d32:
3002     case ARM::VLD3d8_UPD:
3003     case ARM::VLD3d16_UPD:
3004     case ARM::VLD3d32_UPD:
3005     case ARM::VLD4d8:
3006     case ARM::VLD4d16:
3007     case ARM::VLD4d32:
3008     case ARM::VLD4d8_UPD:
3009     case ARM::VLD4d16_UPD:
3010     case ARM::VLD4d32_UPD:
3011       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
3012         return MCDisassembler::Fail;
3013       break;
3014     case ARM::VLD3q8:
3015     case ARM::VLD3q16:
3016     case ARM::VLD3q32:
3017     case ARM::VLD3q8_UPD:
3018     case ARM::VLD3q16_UPD:
3019     case ARM::VLD3q32_UPD:
3020     case ARM::VLD4q8:
3021     case ARM::VLD4q16:
3022     case ARM::VLD4q32:
3023     case ARM::VLD4q8_UPD:
3024     case ARM::VLD4q16_UPD:
3025     case ARM::VLD4q32_UPD:
3026       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
3027         return MCDisassembler::Fail;
3028       break;
3029     default:
3030       break;
3031   }
3032 
3033   // Third output register
3034   switch(Inst.getOpcode()) {
3035     case ARM::VLD3d8:
3036     case ARM::VLD3d16:
3037     case ARM::VLD3d32:
3038     case ARM::VLD3d8_UPD:
3039     case ARM::VLD3d16_UPD:
3040     case ARM::VLD3d32_UPD:
3041     case ARM::VLD4d8:
3042     case ARM::VLD4d16:
3043     case ARM::VLD4d32:
3044     case ARM::VLD4d8_UPD:
3045     case ARM::VLD4d16_UPD:
3046     case ARM::VLD4d32_UPD:
3047       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
3048         return MCDisassembler::Fail;
3049       break;
3050     case ARM::VLD3q8:
3051     case ARM::VLD3q16:
3052     case ARM::VLD3q32:
3053     case ARM::VLD3q8_UPD:
3054     case ARM::VLD3q16_UPD:
3055     case ARM::VLD3q32_UPD:
3056     case ARM::VLD4q8:
3057     case ARM::VLD4q16:
3058     case ARM::VLD4q32:
3059     case ARM::VLD4q8_UPD:
3060     case ARM::VLD4q16_UPD:
3061     case ARM::VLD4q32_UPD:
3062       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
3063         return MCDisassembler::Fail;
3064       break;
3065     default:
3066       break;
3067   }
3068 
3069   // Fourth output register
3070   switch (Inst.getOpcode()) {
3071     case ARM::VLD4d8:
3072     case ARM::VLD4d16:
3073     case ARM::VLD4d32:
3074     case ARM::VLD4d8_UPD:
3075     case ARM::VLD4d16_UPD:
3076     case ARM::VLD4d32_UPD:
3077       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
3078         return MCDisassembler::Fail;
3079       break;
3080     case ARM::VLD4q8:
3081     case ARM::VLD4q16:
3082     case ARM::VLD4q32:
3083     case ARM::VLD4q8_UPD:
3084     case ARM::VLD4q16_UPD:
3085     case ARM::VLD4q32_UPD:
3086       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
3087         return MCDisassembler::Fail;
3088       break;
3089     default:
3090       break;
3091   }
3092 
3093   // Writeback operand
3094   switch (Inst.getOpcode()) {
3095     case ARM::VLD1d8wb_fixed:
3096     case ARM::VLD1d16wb_fixed:
3097     case ARM::VLD1d32wb_fixed:
3098     case ARM::VLD1d64wb_fixed:
3099     case ARM::VLD1d8wb_register:
3100     case ARM::VLD1d16wb_register:
3101     case ARM::VLD1d32wb_register:
3102     case ARM::VLD1d64wb_register:
3103     case ARM::VLD1q8wb_fixed:
3104     case ARM::VLD1q16wb_fixed:
3105     case ARM::VLD1q32wb_fixed:
3106     case ARM::VLD1q64wb_fixed:
3107     case ARM::VLD1q8wb_register:
3108     case ARM::VLD1q16wb_register:
3109     case ARM::VLD1q32wb_register:
3110     case ARM::VLD1q64wb_register:
3111     case ARM::VLD1d8Twb_fixed:
3112     case ARM::VLD1d8Twb_register:
3113     case ARM::VLD1d16Twb_fixed:
3114     case ARM::VLD1d16Twb_register:
3115     case ARM::VLD1d32Twb_fixed:
3116     case ARM::VLD1d32Twb_register:
3117     case ARM::VLD1d64Twb_fixed:
3118     case ARM::VLD1d64Twb_register:
3119     case ARM::VLD1d8Qwb_fixed:
3120     case ARM::VLD1d8Qwb_register:
3121     case ARM::VLD1d16Qwb_fixed:
3122     case ARM::VLD1d16Qwb_register:
3123     case ARM::VLD1d32Qwb_fixed:
3124     case ARM::VLD1d32Qwb_register:
3125     case ARM::VLD1d64Qwb_fixed:
3126     case ARM::VLD1d64Qwb_register:
3127     case ARM::VLD2d8wb_fixed:
3128     case ARM::VLD2d16wb_fixed:
3129     case ARM::VLD2d32wb_fixed:
3130     case ARM::VLD2q8wb_fixed:
3131     case ARM::VLD2q16wb_fixed:
3132     case ARM::VLD2q32wb_fixed:
3133     case ARM::VLD2d8wb_register:
3134     case ARM::VLD2d16wb_register:
3135     case ARM::VLD2d32wb_register:
3136     case ARM::VLD2q8wb_register:
3137     case ARM::VLD2q16wb_register:
3138     case ARM::VLD2q32wb_register:
3139     case ARM::VLD2b8wb_fixed:
3140     case ARM::VLD2b16wb_fixed:
3141     case ARM::VLD2b32wb_fixed:
3142     case ARM::VLD2b8wb_register:
3143     case ARM::VLD2b16wb_register:
3144     case ARM::VLD2b32wb_register:
3145       Inst.addOperand(MCOperand::createImm(0));
3146       break;
3147     case ARM::VLD3d8_UPD:
3148     case ARM::VLD3d16_UPD:
3149     case ARM::VLD3d32_UPD:
3150     case ARM::VLD3q8_UPD:
3151     case ARM::VLD3q16_UPD:
3152     case ARM::VLD3q32_UPD:
3153     case ARM::VLD4d8_UPD:
3154     case ARM::VLD4d16_UPD:
3155     case ARM::VLD4d32_UPD:
3156     case ARM::VLD4q8_UPD:
3157     case ARM::VLD4q16_UPD:
3158     case ARM::VLD4q32_UPD:
3159       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
3160         return MCDisassembler::Fail;
3161       break;
3162     default:
3163       break;
3164   }
3165 
3166   // AddrMode6 Base (register+alignment)
3167   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
3168     return MCDisassembler::Fail;
3169 
3170   // AddrMode6 Offset (register)
3171   switch (Inst.getOpcode()) {
3172   default:
3173     // The below have been updated to have explicit am6offset split
3174     // between fixed and register offset. For those instructions not
3175     // yet updated, we need to add an additional reg0 operand for the
3176     // fixed variant.
3177     //
3178     // The fixed offset encodes as Rm == 0xd, so we check for that.
3179     if (Rm == 0xd) {
3180       Inst.addOperand(MCOperand::createReg(0));
3181       break;
3182     }
3183     // Fall through to handle the register offset variant.
3184     [[fallthrough]];
3185   case ARM::VLD1d8wb_fixed:
3186   case ARM::VLD1d16wb_fixed:
3187   case ARM::VLD1d32wb_fixed:
3188   case ARM::VLD1d64wb_fixed:
3189   case ARM::VLD1d8Twb_fixed:
3190   case ARM::VLD1d16Twb_fixed:
3191   case ARM::VLD1d32Twb_fixed:
3192   case ARM::VLD1d64Twb_fixed:
3193   case ARM::VLD1d8Qwb_fixed:
3194   case ARM::VLD1d16Qwb_fixed:
3195   case ARM::VLD1d32Qwb_fixed:
3196   case ARM::VLD1d64Qwb_fixed:
3197   case ARM::VLD1d8wb_register:
3198   case ARM::VLD1d16wb_register:
3199   case ARM::VLD1d32wb_register:
3200   case ARM::VLD1d64wb_register:
3201   case ARM::VLD1q8wb_fixed:
3202   case ARM::VLD1q16wb_fixed:
3203   case ARM::VLD1q32wb_fixed:
3204   case ARM::VLD1q64wb_fixed:
3205   case ARM::VLD1q8wb_register:
3206   case ARM::VLD1q16wb_register:
3207   case ARM::VLD1q32wb_register:
3208   case ARM::VLD1q64wb_register:
3209     // The fixed offset post-increment encodes Rm == 0xd. The no-writeback
3210     // variant encodes Rm == 0xf. Anything else is a register offset post-
3211     // increment and we need to add the register operand to the instruction.
3212     if (Rm != 0xD && Rm != 0xF &&
3213         !Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3214       return MCDisassembler::Fail;
3215     break;
3216   case ARM::VLD2d8wb_fixed:
3217   case ARM::VLD2d16wb_fixed:
3218   case ARM::VLD2d32wb_fixed:
3219   case ARM::VLD2b8wb_fixed:
3220   case ARM::VLD2b16wb_fixed:
3221   case ARM::VLD2b32wb_fixed:
3222   case ARM::VLD2q8wb_fixed:
3223   case ARM::VLD2q16wb_fixed:
3224   case ARM::VLD2q32wb_fixed:
3225     break;
3226   }
3227 
3228   return S;
3229 }
3230 
3231 static DecodeStatus DecodeVLDST1Instruction(MCInst &Inst, unsigned Insn,
3232                                             uint64_t Address,
3233                                             const MCDisassembler *Decoder) {
3234   unsigned type = fieldFromInstruction(Insn, 8, 4);
3235   unsigned align = fieldFromInstruction(Insn, 4, 2);
3236   if (type == 6 && (align & 2)) return MCDisassembler::Fail;
3237   if (type == 7 && (align & 2)) return MCDisassembler::Fail;
3238   if (type == 10 && align == 3) return MCDisassembler::Fail;
3239 
3240   unsigned load = fieldFromInstruction(Insn, 21, 1);
3241   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
3242               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
3243 }
3244 
3245 static DecodeStatus DecodeVLDST2Instruction(MCInst &Inst, unsigned Insn,
3246                                             uint64_t Address,
3247                                             const MCDisassembler *Decoder) {
3248   unsigned size = fieldFromInstruction(Insn, 6, 2);
3249   if (size == 3) return MCDisassembler::Fail;
3250 
3251   unsigned type = fieldFromInstruction(Insn, 8, 4);
3252   unsigned align = fieldFromInstruction(Insn, 4, 2);
3253   if (type == 8 && align == 3) return MCDisassembler::Fail;
3254   if (type == 9 && align == 3) return MCDisassembler::Fail;
3255 
3256   unsigned load = fieldFromInstruction(Insn, 21, 1);
3257   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
3258               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
3259 }
3260 
3261 static DecodeStatus DecodeVLDST3Instruction(MCInst &Inst, unsigned Insn,
3262                                             uint64_t Address,
3263                                             const MCDisassembler *Decoder) {
3264   unsigned size = fieldFromInstruction(Insn, 6, 2);
3265   if (size == 3) return MCDisassembler::Fail;
3266 
3267   unsigned align = fieldFromInstruction(Insn, 4, 2);
3268   if (align & 2) return MCDisassembler::Fail;
3269 
3270   unsigned load = fieldFromInstruction(Insn, 21, 1);
3271   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
3272               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
3273 }
3274 
3275 static DecodeStatus DecodeVLDST4Instruction(MCInst &Inst, unsigned Insn,
3276                                             uint64_t Address,
3277                                             const MCDisassembler *Decoder) {
3278   unsigned size = fieldFromInstruction(Insn, 6, 2);
3279   if (size == 3) return MCDisassembler::Fail;
3280 
3281   unsigned load = fieldFromInstruction(Insn, 21, 1);
3282   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
3283               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
3284 }
3285 
3286 static DecodeStatus DecodeVSTInstruction(MCInst &Inst, unsigned Insn,
3287                                          uint64_t Address,
3288                                          const MCDisassembler *Decoder) {
3289   DecodeStatus S = MCDisassembler::Success;
3290 
3291   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3292   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3293   unsigned wb = fieldFromInstruction(Insn, 16, 4);
3294   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3295   Rn |= fieldFromInstruction(Insn, 4, 2) << 4;
3296   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3297 
3298   // Writeback Operand
3299   switch (Inst.getOpcode()) {
3300     case ARM::VST1d8wb_fixed:
3301     case ARM::VST1d16wb_fixed:
3302     case ARM::VST1d32wb_fixed:
3303     case ARM::VST1d64wb_fixed:
3304     case ARM::VST1d8wb_register:
3305     case ARM::VST1d16wb_register:
3306     case ARM::VST1d32wb_register:
3307     case ARM::VST1d64wb_register:
3308     case ARM::VST1q8wb_fixed:
3309     case ARM::VST1q16wb_fixed:
3310     case ARM::VST1q32wb_fixed:
3311     case ARM::VST1q64wb_fixed:
3312     case ARM::VST1q8wb_register:
3313     case ARM::VST1q16wb_register:
3314     case ARM::VST1q32wb_register:
3315     case ARM::VST1q64wb_register:
3316     case ARM::VST1d8Twb_fixed:
3317     case ARM::VST1d16Twb_fixed:
3318     case ARM::VST1d32Twb_fixed:
3319     case ARM::VST1d64Twb_fixed:
3320     case ARM::VST1d8Twb_register:
3321     case ARM::VST1d16Twb_register:
3322     case ARM::VST1d32Twb_register:
3323     case ARM::VST1d64Twb_register:
3324     case ARM::VST1d8Qwb_fixed:
3325     case ARM::VST1d16Qwb_fixed:
3326     case ARM::VST1d32Qwb_fixed:
3327     case ARM::VST1d64Qwb_fixed:
3328     case ARM::VST1d8Qwb_register:
3329     case ARM::VST1d16Qwb_register:
3330     case ARM::VST1d32Qwb_register:
3331     case ARM::VST1d64Qwb_register:
3332     case ARM::VST2d8wb_fixed:
3333     case ARM::VST2d16wb_fixed:
3334     case ARM::VST2d32wb_fixed:
3335     case ARM::VST2d8wb_register:
3336     case ARM::VST2d16wb_register:
3337     case ARM::VST2d32wb_register:
3338     case ARM::VST2q8wb_fixed:
3339     case ARM::VST2q16wb_fixed:
3340     case ARM::VST2q32wb_fixed:
3341     case ARM::VST2q8wb_register:
3342     case ARM::VST2q16wb_register:
3343     case ARM::VST2q32wb_register:
3344     case ARM::VST2b8wb_fixed:
3345     case ARM::VST2b16wb_fixed:
3346     case ARM::VST2b32wb_fixed:
3347     case ARM::VST2b8wb_register:
3348     case ARM::VST2b16wb_register:
3349     case ARM::VST2b32wb_register:
3350       if (Rm == 0xF)
3351         return MCDisassembler::Fail;
3352       Inst.addOperand(MCOperand::createImm(0));
3353       break;
3354     case ARM::VST3d8_UPD:
3355     case ARM::VST3d16_UPD:
3356     case ARM::VST3d32_UPD:
3357     case ARM::VST3q8_UPD:
3358     case ARM::VST3q16_UPD:
3359     case ARM::VST3q32_UPD:
3360     case ARM::VST4d8_UPD:
3361     case ARM::VST4d16_UPD:
3362     case ARM::VST4d32_UPD:
3363     case ARM::VST4q8_UPD:
3364     case ARM::VST4q16_UPD:
3365     case ARM::VST4q32_UPD:
3366       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
3367         return MCDisassembler::Fail;
3368       break;
3369     default:
3370       break;
3371   }
3372 
3373   // AddrMode6 Base (register+alignment)
3374   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
3375     return MCDisassembler::Fail;
3376 
3377   // AddrMode6 Offset (register)
3378   switch (Inst.getOpcode()) {
3379     default:
3380       if (Rm == 0xD)
3381         Inst.addOperand(MCOperand::createReg(0));
3382       else if (Rm != 0xF) {
3383         if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3384           return MCDisassembler::Fail;
3385       }
3386       break;
3387     case ARM::VST1d8wb_fixed:
3388     case ARM::VST1d16wb_fixed:
3389     case ARM::VST1d32wb_fixed:
3390     case ARM::VST1d64wb_fixed:
3391     case ARM::VST1q8wb_fixed:
3392     case ARM::VST1q16wb_fixed:
3393     case ARM::VST1q32wb_fixed:
3394     case ARM::VST1q64wb_fixed:
3395     case ARM::VST1d8Twb_fixed:
3396     case ARM::VST1d16Twb_fixed:
3397     case ARM::VST1d32Twb_fixed:
3398     case ARM::VST1d64Twb_fixed:
3399     case ARM::VST1d8Qwb_fixed:
3400     case ARM::VST1d16Qwb_fixed:
3401     case ARM::VST1d32Qwb_fixed:
3402     case ARM::VST1d64Qwb_fixed:
3403     case ARM::VST2d8wb_fixed:
3404     case ARM::VST2d16wb_fixed:
3405     case ARM::VST2d32wb_fixed:
3406     case ARM::VST2q8wb_fixed:
3407     case ARM::VST2q16wb_fixed:
3408     case ARM::VST2q32wb_fixed:
3409     case ARM::VST2b8wb_fixed:
3410     case ARM::VST2b16wb_fixed:
3411     case ARM::VST2b32wb_fixed:
3412       break;
3413   }
3414 
3415   // First input register
3416   switch (Inst.getOpcode()) {
3417   case ARM::VST1q16:
3418   case ARM::VST1q32:
3419   case ARM::VST1q64:
3420   case ARM::VST1q8:
3421   case ARM::VST1q16wb_fixed:
3422   case ARM::VST1q16wb_register:
3423   case ARM::VST1q32wb_fixed:
3424   case ARM::VST1q32wb_register:
3425   case ARM::VST1q64wb_fixed:
3426   case ARM::VST1q64wb_register:
3427   case ARM::VST1q8wb_fixed:
3428   case ARM::VST1q8wb_register:
3429   case ARM::VST2d16:
3430   case ARM::VST2d32:
3431   case ARM::VST2d8:
3432   case ARM::VST2d16wb_fixed:
3433   case ARM::VST2d16wb_register:
3434   case ARM::VST2d32wb_fixed:
3435   case ARM::VST2d32wb_register:
3436   case ARM::VST2d8wb_fixed:
3437   case ARM::VST2d8wb_register:
3438     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3439       return MCDisassembler::Fail;
3440     break;
3441   case ARM::VST2b16:
3442   case ARM::VST2b32:
3443   case ARM::VST2b8:
3444   case ARM::VST2b16wb_fixed:
3445   case ARM::VST2b16wb_register:
3446   case ARM::VST2b32wb_fixed:
3447   case ARM::VST2b32wb_register:
3448   case ARM::VST2b8wb_fixed:
3449   case ARM::VST2b8wb_register:
3450     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
3451       return MCDisassembler::Fail;
3452     break;
3453   default:
3454     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3455       return MCDisassembler::Fail;
3456   }
3457 
3458   // Second input register
3459   switch (Inst.getOpcode()) {
3460     case ARM::VST3d8:
3461     case ARM::VST3d16:
3462     case ARM::VST3d32:
3463     case ARM::VST3d8_UPD:
3464     case ARM::VST3d16_UPD:
3465     case ARM::VST3d32_UPD:
3466     case ARM::VST4d8:
3467     case ARM::VST4d16:
3468     case ARM::VST4d32:
3469     case ARM::VST4d8_UPD:
3470     case ARM::VST4d16_UPD:
3471     case ARM::VST4d32_UPD:
3472       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
3473         return MCDisassembler::Fail;
3474       break;
3475     case ARM::VST3q8:
3476     case ARM::VST3q16:
3477     case ARM::VST3q32:
3478     case ARM::VST3q8_UPD:
3479     case ARM::VST3q16_UPD:
3480     case ARM::VST3q32_UPD:
3481     case ARM::VST4q8:
3482     case ARM::VST4q16:
3483     case ARM::VST4q32:
3484     case ARM::VST4q8_UPD:
3485     case ARM::VST4q16_UPD:
3486     case ARM::VST4q32_UPD:
3487       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
3488         return MCDisassembler::Fail;
3489       break;
3490     default:
3491       break;
3492   }
3493 
3494   // Third input register
3495   switch (Inst.getOpcode()) {
3496     case ARM::VST3d8:
3497     case ARM::VST3d16:
3498     case ARM::VST3d32:
3499     case ARM::VST3d8_UPD:
3500     case ARM::VST3d16_UPD:
3501     case ARM::VST3d32_UPD:
3502     case ARM::VST4d8:
3503     case ARM::VST4d16:
3504     case ARM::VST4d32:
3505     case ARM::VST4d8_UPD:
3506     case ARM::VST4d16_UPD:
3507     case ARM::VST4d32_UPD:
3508       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
3509         return MCDisassembler::Fail;
3510       break;
3511     case ARM::VST3q8:
3512     case ARM::VST3q16:
3513     case ARM::VST3q32:
3514     case ARM::VST3q8_UPD:
3515     case ARM::VST3q16_UPD:
3516     case ARM::VST3q32_UPD:
3517     case ARM::VST4q8:
3518     case ARM::VST4q16:
3519     case ARM::VST4q32:
3520     case ARM::VST4q8_UPD:
3521     case ARM::VST4q16_UPD:
3522     case ARM::VST4q32_UPD:
3523       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
3524         return MCDisassembler::Fail;
3525       break;
3526     default:
3527       break;
3528   }
3529 
3530   // Fourth input register
3531   switch (Inst.getOpcode()) {
3532     case ARM::VST4d8:
3533     case ARM::VST4d16:
3534     case ARM::VST4d32:
3535     case ARM::VST4d8_UPD:
3536     case ARM::VST4d16_UPD:
3537     case ARM::VST4d32_UPD:
3538       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
3539         return MCDisassembler::Fail;
3540       break;
3541     case ARM::VST4q8:
3542     case ARM::VST4q16:
3543     case ARM::VST4q32:
3544     case ARM::VST4q8_UPD:
3545     case ARM::VST4q16_UPD:
3546     case ARM::VST4q32_UPD:
3547       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
3548         return MCDisassembler::Fail;
3549       break;
3550     default:
3551       break;
3552   }
3553 
3554   return S;
3555 }
3556 
3557 static DecodeStatus DecodeVLD1DupInstruction(MCInst &Inst, unsigned Insn,
3558                                              uint64_t Address,
3559                                              const MCDisassembler *Decoder) {
3560   DecodeStatus S = MCDisassembler::Success;
3561 
3562   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3563   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3564   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3565   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3566   unsigned align = fieldFromInstruction(Insn, 4, 1);
3567   unsigned size = fieldFromInstruction(Insn, 6, 2);
3568 
3569   if (size == 0 && align == 1)
3570     return MCDisassembler::Fail;
3571   align *= (1 << size);
3572 
3573   switch (Inst.getOpcode()) {
3574   case ARM::VLD1DUPq16: case ARM::VLD1DUPq32: case ARM::VLD1DUPq8:
3575   case ARM::VLD1DUPq16wb_fixed: case ARM::VLD1DUPq16wb_register:
3576   case ARM::VLD1DUPq32wb_fixed: case ARM::VLD1DUPq32wb_register:
3577   case ARM::VLD1DUPq8wb_fixed: case ARM::VLD1DUPq8wb_register:
3578     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3579       return MCDisassembler::Fail;
3580     break;
3581   default:
3582     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3583       return MCDisassembler::Fail;
3584     break;
3585   }
3586   if (Rm != 0xF) {
3587     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3588       return MCDisassembler::Fail;
3589   }
3590 
3591   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3592     return MCDisassembler::Fail;
3593   Inst.addOperand(MCOperand::createImm(align));
3594 
3595   // The fixed offset post-increment encodes Rm == 0xd. The no-writeback
3596   // variant encodes Rm == 0xf. Anything else is a register offset post-
3597   // increment and we need to add the register operand to the instruction.
3598   if (Rm != 0xD && Rm != 0xF &&
3599       !Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3600     return MCDisassembler::Fail;
3601 
3602   return S;
3603 }
3604 
3605 static DecodeStatus DecodeVLD2DupInstruction(MCInst &Inst, unsigned Insn,
3606                                              uint64_t Address,
3607                                              const MCDisassembler *Decoder) {
3608   DecodeStatus S = MCDisassembler::Success;
3609 
3610   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3611   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3612   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3613   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3614   unsigned align = fieldFromInstruction(Insn, 4, 1);
3615   unsigned size = 1 << fieldFromInstruction(Insn, 6, 2);
3616   align *= 2*size;
3617 
3618   switch (Inst.getOpcode()) {
3619   case ARM::VLD2DUPd16: case ARM::VLD2DUPd32: case ARM::VLD2DUPd8:
3620   case ARM::VLD2DUPd16wb_fixed: case ARM::VLD2DUPd16wb_register:
3621   case ARM::VLD2DUPd32wb_fixed: case ARM::VLD2DUPd32wb_register:
3622   case ARM::VLD2DUPd8wb_fixed: case ARM::VLD2DUPd8wb_register:
3623     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3624       return MCDisassembler::Fail;
3625     break;
3626   case ARM::VLD2DUPd16x2: case ARM::VLD2DUPd32x2: case ARM::VLD2DUPd8x2:
3627   case ARM::VLD2DUPd16x2wb_fixed: case ARM::VLD2DUPd16x2wb_register:
3628   case ARM::VLD2DUPd32x2wb_fixed: case ARM::VLD2DUPd32x2wb_register:
3629   case ARM::VLD2DUPd8x2wb_fixed: case ARM::VLD2DUPd8x2wb_register:
3630     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
3631       return MCDisassembler::Fail;
3632     break;
3633   default:
3634     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3635       return MCDisassembler::Fail;
3636     break;
3637   }
3638 
3639   if (Rm != 0xF)
3640     Inst.addOperand(MCOperand::createImm(0));
3641 
3642   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3643     return MCDisassembler::Fail;
3644   Inst.addOperand(MCOperand::createImm(align));
3645 
3646   if (Rm != 0xD && Rm != 0xF) {
3647     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3648       return MCDisassembler::Fail;
3649   }
3650 
3651   return S;
3652 }
3653 
3654 static DecodeStatus DecodeVLD3DupInstruction(MCInst &Inst, unsigned Insn,
3655                                              uint64_t Address,
3656                                              const MCDisassembler *Decoder) {
3657   DecodeStatus S = MCDisassembler::Success;
3658 
3659   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3660   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3661   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3662   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3663   unsigned inc = fieldFromInstruction(Insn, 5, 1) + 1;
3664 
3665   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3666     return MCDisassembler::Fail;
3667   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
3668     return MCDisassembler::Fail;
3669   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
3670     return MCDisassembler::Fail;
3671   if (Rm != 0xF) {
3672     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3673       return MCDisassembler::Fail;
3674   }
3675 
3676   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3677     return MCDisassembler::Fail;
3678   Inst.addOperand(MCOperand::createImm(0));
3679 
3680   if (Rm == 0xD)
3681     Inst.addOperand(MCOperand::createReg(0));
3682   else if (Rm != 0xF) {
3683     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3684       return MCDisassembler::Fail;
3685   }
3686 
3687   return S;
3688 }
3689 
3690 static DecodeStatus DecodeVLD4DupInstruction(MCInst &Inst, unsigned Insn,
3691                                              uint64_t Address,
3692                                              const MCDisassembler *Decoder) {
3693   DecodeStatus S = MCDisassembler::Success;
3694 
3695   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3696   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3697   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3698   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3699   unsigned size = fieldFromInstruction(Insn, 6, 2);
3700   unsigned inc = fieldFromInstruction(Insn, 5, 1) + 1;
3701   unsigned align = fieldFromInstruction(Insn, 4, 1);
3702 
3703   if (size == 0x3) {
3704     if (align == 0)
3705       return MCDisassembler::Fail;
3706     align = 16;
3707   } else {
3708     if (size == 2) {
3709       align *= 8;
3710     } else {
3711       size = 1 << size;
3712       align *= 4*size;
3713     }
3714   }
3715 
3716   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3717     return MCDisassembler::Fail;
3718   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
3719     return MCDisassembler::Fail;
3720   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
3721     return MCDisassembler::Fail;
3722   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3*inc)%32, Address, Decoder)))
3723     return MCDisassembler::Fail;
3724   if (Rm != 0xF) {
3725     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3726       return MCDisassembler::Fail;
3727   }
3728 
3729   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3730     return MCDisassembler::Fail;
3731   Inst.addOperand(MCOperand::createImm(align));
3732 
3733   if (Rm == 0xD)
3734     Inst.addOperand(MCOperand::createReg(0));
3735   else if (Rm != 0xF) {
3736     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3737       return MCDisassembler::Fail;
3738   }
3739 
3740   return S;
3741 }
3742 
3743 static DecodeStatus DecodeVMOVModImmInstruction(MCInst &Inst, unsigned Insn,
3744                                                 uint64_t Address,
3745                                                 const MCDisassembler *Decoder) {
3746   DecodeStatus S = MCDisassembler::Success;
3747 
3748   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3749   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3750   unsigned imm = fieldFromInstruction(Insn, 0, 4);
3751   imm |= fieldFromInstruction(Insn, 16, 3) << 4;
3752   imm |= fieldFromInstruction(Insn, 24, 1) << 7;
3753   imm |= fieldFromInstruction(Insn, 8, 4) << 8;
3754   imm |= fieldFromInstruction(Insn, 5, 1) << 12;
3755   unsigned Q = fieldFromInstruction(Insn, 6, 1);
3756 
3757   if (Q) {
3758     if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3759     return MCDisassembler::Fail;
3760   } else {
3761     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3762     return MCDisassembler::Fail;
3763   }
3764 
3765   Inst.addOperand(MCOperand::createImm(imm));
3766 
3767   switch (Inst.getOpcode()) {
3768     case ARM::VORRiv4i16:
3769     case ARM::VORRiv2i32:
3770     case ARM::VBICiv4i16:
3771     case ARM::VBICiv2i32:
3772       if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3773         return MCDisassembler::Fail;
3774       break;
3775     case ARM::VORRiv8i16:
3776     case ARM::VORRiv4i32:
3777     case ARM::VBICiv8i16:
3778     case ARM::VBICiv4i32:
3779       if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3780         return MCDisassembler::Fail;
3781       break;
3782     default:
3783       break;
3784   }
3785 
3786   return S;
3787 }
3788 
3789 static DecodeStatus DecodeMVEModImmInstruction(MCInst &Inst, unsigned Insn,
3790                                                uint64_t Address,
3791                                                const MCDisassembler *Decoder) {
3792   DecodeStatus S = MCDisassembler::Success;
3793 
3794   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
3795                  fieldFromInstruction(Insn, 13, 3));
3796   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
3797   unsigned imm = fieldFromInstruction(Insn, 0, 4);
3798   imm |= fieldFromInstruction(Insn, 16, 3) << 4;
3799   imm |= fieldFromInstruction(Insn, 28, 1) << 7;
3800   imm |= cmode                             << 8;
3801   imm |= fieldFromInstruction(Insn, 5, 1)  << 12;
3802 
3803   if (cmode == 0xF && Inst.getOpcode() == ARM::MVE_VMVNimmi32)
3804     return MCDisassembler::Fail;
3805 
3806   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
3807     return MCDisassembler::Fail;
3808 
3809   Inst.addOperand(MCOperand::createImm(imm));
3810 
3811   Inst.addOperand(MCOperand::createImm(ARMVCC::None));
3812   Inst.addOperand(MCOperand::createReg(0));
3813   Inst.addOperand(MCOperand::createImm(0));
3814 
3815   return S;
3816 }
3817 
3818 static DecodeStatus DecodeMVEVADCInstruction(MCInst &Inst, unsigned Insn,
3819                                              uint64_t Address,
3820                                              const MCDisassembler *Decoder) {
3821   DecodeStatus S = MCDisassembler::Success;
3822 
3823   unsigned Qd = fieldFromInstruction(Insn, 13, 3);
3824   Qd |= fieldFromInstruction(Insn, 22, 1) << 3;
3825   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
3826     return MCDisassembler::Fail;
3827   Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
3828 
3829   unsigned Qn = fieldFromInstruction(Insn, 17, 3);
3830   Qn |= fieldFromInstruction(Insn, 7, 1) << 3;
3831   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qn, Address, Decoder)))
3832     return MCDisassembler::Fail;
3833   unsigned Qm = fieldFromInstruction(Insn, 1, 3);
3834   Qm |= fieldFromInstruction(Insn, 5, 1) << 3;
3835   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
3836     return MCDisassembler::Fail;
3837   if (!fieldFromInstruction(Insn, 12, 1)) // I bit clear => need input FPSCR
3838     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
3839   Inst.addOperand(MCOperand::createImm(Qd));
3840 
3841   return S;
3842 }
3843 
3844 static DecodeStatus DecodeVSHLMaxInstruction(MCInst &Inst, unsigned Insn,
3845                                              uint64_t Address,
3846                                              const MCDisassembler *Decoder) {
3847   DecodeStatus S = MCDisassembler::Success;
3848 
3849   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3850   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3851   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3852   Rm |= fieldFromInstruction(Insn, 5, 1) << 4;
3853   unsigned size = fieldFromInstruction(Insn, 18, 2);
3854 
3855   if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3856     return MCDisassembler::Fail;
3857   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
3858     return MCDisassembler::Fail;
3859   Inst.addOperand(MCOperand::createImm(8 << size));
3860 
3861   return S;
3862 }
3863 
3864 static DecodeStatus DecodeShiftRight8Imm(MCInst &Inst, unsigned Val,
3865                                          uint64_t Address,
3866                                          const MCDisassembler *Decoder) {
3867   Inst.addOperand(MCOperand::createImm(8 - Val));
3868   return MCDisassembler::Success;
3869 }
3870 
3871 static DecodeStatus DecodeShiftRight16Imm(MCInst &Inst, unsigned Val,
3872                                           uint64_t Address,
3873                                           const MCDisassembler *Decoder) {
3874   Inst.addOperand(MCOperand::createImm(16 - Val));
3875   return MCDisassembler::Success;
3876 }
3877 
3878 static DecodeStatus DecodeShiftRight32Imm(MCInst &Inst, unsigned Val,
3879                                           uint64_t Address,
3880                                           const MCDisassembler *Decoder) {
3881   Inst.addOperand(MCOperand::createImm(32 - Val));
3882   return MCDisassembler::Success;
3883 }
3884 
3885 static DecodeStatus DecodeShiftRight64Imm(MCInst &Inst, unsigned Val,
3886                                           uint64_t Address,
3887                                           const MCDisassembler *Decoder) {
3888   Inst.addOperand(MCOperand::createImm(64 - Val));
3889   return MCDisassembler::Success;
3890 }
3891 
3892 static DecodeStatus DecodeTBLInstruction(MCInst &Inst, unsigned Insn,
3893                                          uint64_t Address,
3894                                          const MCDisassembler *Decoder) {
3895   DecodeStatus S = MCDisassembler::Success;
3896 
3897   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3898   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3899   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3900   Rn |= fieldFromInstruction(Insn, 7, 1) << 4;
3901   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3902   Rm |= fieldFromInstruction(Insn, 5, 1) << 4;
3903   unsigned op = fieldFromInstruction(Insn, 6, 1);
3904 
3905   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3906     return MCDisassembler::Fail;
3907   if (op) {
3908     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3909     return MCDisassembler::Fail; // Writeback
3910   }
3911 
3912   switch (Inst.getOpcode()) {
3913   case ARM::VTBL2:
3914   case ARM::VTBX2:
3915     if (!Check(S, DecodeDPairRegisterClass(Inst, Rn, Address, Decoder)))
3916       return MCDisassembler::Fail;
3917     break;
3918   default:
3919     if (!Check(S, DecodeDPRRegisterClass(Inst, Rn, Address, Decoder)))
3920       return MCDisassembler::Fail;
3921   }
3922 
3923   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
3924     return MCDisassembler::Fail;
3925 
3926   return S;
3927 }
3928 
3929 static DecodeStatus DecodeThumbAddSpecialReg(MCInst &Inst, uint16_t Insn,
3930                                              uint64_t Address,
3931                                              const MCDisassembler *Decoder) {
3932   DecodeStatus S = MCDisassembler::Success;
3933 
3934   unsigned dst = fieldFromInstruction(Insn, 8, 3);
3935   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3936 
3937   if (!Check(S, DecodetGPRRegisterClass(Inst, dst, Address, Decoder)))
3938     return MCDisassembler::Fail;
3939 
3940   switch(Inst.getOpcode()) {
3941     default:
3942       return MCDisassembler::Fail;
3943     case ARM::tADR:
3944       break; // tADR does not explicitly represent the PC as an operand.
3945     case ARM::tADDrSPi:
3946       Inst.addOperand(MCOperand::createReg(ARM::SP));
3947       break;
3948   }
3949 
3950   Inst.addOperand(MCOperand::createImm(imm));
3951   return S;
3952 }
3953 
3954 static DecodeStatus DecodeThumbBROperand(MCInst &Inst, unsigned Val,
3955                                          uint64_t Address,
3956                                          const MCDisassembler *Decoder) {
3957   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<12>(Val<<1) + 4,
3958                                 true, 2, Inst, Decoder))
3959     Inst.addOperand(MCOperand::createImm(SignExtend32<12>(Val << 1)));
3960   return MCDisassembler::Success;
3961 }
3962 
3963 static DecodeStatus DecodeT2BROperand(MCInst &Inst, unsigned Val,
3964                                       uint64_t Address,
3965                                       const MCDisassembler *Decoder) {
3966   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<21>(Val) + 4,
3967                                 true, 4, Inst, Decoder))
3968     Inst.addOperand(MCOperand::createImm(SignExtend32<21>(Val)));
3969   return MCDisassembler::Success;
3970 }
3971 
3972 static DecodeStatus DecodeThumbCmpBROperand(MCInst &Inst, unsigned Val,
3973                                             uint64_t Address,
3974                                             const MCDisassembler *Decoder) {
3975   if (!tryAddingSymbolicOperand(Address, Address + (Val<<1) + 4,
3976                                 true, 2, Inst, Decoder))
3977     Inst.addOperand(MCOperand::createImm(Val << 1));
3978   return MCDisassembler::Success;
3979 }
3980 
3981 static DecodeStatus DecodeThumbAddrModeRR(MCInst &Inst, unsigned Val,
3982                                           uint64_t Address,
3983                                           const MCDisassembler *Decoder) {
3984   DecodeStatus S = MCDisassembler::Success;
3985 
3986   unsigned Rn = fieldFromInstruction(Val, 0, 3);
3987   unsigned Rm = fieldFromInstruction(Val, 3, 3);
3988 
3989   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
3990     return MCDisassembler::Fail;
3991   if (!Check(S, DecodetGPRRegisterClass(Inst, Rm, Address, Decoder)))
3992     return MCDisassembler::Fail;
3993 
3994   return S;
3995 }
3996 
3997 static DecodeStatus DecodeThumbAddrModeIS(MCInst &Inst, unsigned Val,
3998                                           uint64_t Address,
3999                                           const MCDisassembler *Decoder) {
4000   DecodeStatus S = MCDisassembler::Success;
4001 
4002   unsigned Rn = fieldFromInstruction(Val, 0, 3);
4003   unsigned imm = fieldFromInstruction(Val, 3, 5);
4004 
4005   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
4006     return MCDisassembler::Fail;
4007   Inst.addOperand(MCOperand::createImm(imm));
4008 
4009   return S;
4010 }
4011 
4012 static DecodeStatus DecodeThumbAddrModePC(MCInst &Inst, unsigned Val,
4013                                           uint64_t Address,
4014                                           const MCDisassembler *Decoder) {
4015   unsigned imm = Val << 2;
4016 
4017   Inst.addOperand(MCOperand::createImm(imm));
4018   tryAddingPcLoadReferenceComment(Address, (Address & ~2u) + imm + 4, Decoder);
4019 
4020   return MCDisassembler::Success;
4021 }
4022 
4023 static DecodeStatus DecodeThumbAddrModeSP(MCInst &Inst, unsigned Val,
4024                                           uint64_t Address,
4025                                           const MCDisassembler *Decoder) {
4026   Inst.addOperand(MCOperand::createReg(ARM::SP));
4027   Inst.addOperand(MCOperand::createImm(Val));
4028 
4029   return MCDisassembler::Success;
4030 }
4031 
4032 static DecodeStatus DecodeT2AddrModeSOReg(MCInst &Inst, unsigned Val,
4033                                           uint64_t Address,
4034                                           const MCDisassembler *Decoder) {
4035   DecodeStatus S = MCDisassembler::Success;
4036 
4037   unsigned Rn = fieldFromInstruction(Val, 6, 4);
4038   unsigned Rm = fieldFromInstruction(Val, 2, 4);
4039   unsigned imm = fieldFromInstruction(Val, 0, 2);
4040 
4041   // Thumb stores cannot use PC as dest register.
4042   switch (Inst.getOpcode()) {
4043   case ARM::t2STRHs:
4044   case ARM::t2STRBs:
4045   case ARM::t2STRs:
4046     if (Rn == 15)
4047       return MCDisassembler::Fail;
4048     break;
4049   default:
4050     break;
4051   }
4052 
4053   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4054     return MCDisassembler::Fail;
4055   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
4056     return MCDisassembler::Fail;
4057   Inst.addOperand(MCOperand::createImm(imm));
4058 
4059   return S;
4060 }
4061 
4062 static DecodeStatus DecodeT2LoadShift(MCInst &Inst, unsigned Insn,
4063                                       uint64_t Address,
4064                                       const MCDisassembler *Decoder) {
4065   DecodeStatus S = MCDisassembler::Success;
4066 
4067   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4068   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4069 
4070   const FeatureBitset &featureBits =
4071     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4072 
4073   bool hasMP = featureBits[ARM::FeatureMP];
4074   bool hasV7Ops = featureBits[ARM::HasV7Ops];
4075 
4076   if (Rn == 15) {
4077     switch (Inst.getOpcode()) {
4078     case ARM::t2LDRBs:
4079       Inst.setOpcode(ARM::t2LDRBpci);
4080       break;
4081     case ARM::t2LDRHs:
4082       Inst.setOpcode(ARM::t2LDRHpci);
4083       break;
4084     case ARM::t2LDRSHs:
4085       Inst.setOpcode(ARM::t2LDRSHpci);
4086       break;
4087     case ARM::t2LDRSBs:
4088       Inst.setOpcode(ARM::t2LDRSBpci);
4089       break;
4090     case ARM::t2LDRs:
4091       Inst.setOpcode(ARM::t2LDRpci);
4092       break;
4093     case ARM::t2PLDs:
4094       Inst.setOpcode(ARM::t2PLDpci);
4095       break;
4096     case ARM::t2PLIs:
4097       Inst.setOpcode(ARM::t2PLIpci);
4098       break;
4099     default:
4100       return MCDisassembler::Fail;
4101     }
4102 
4103     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
4104   }
4105 
4106   if (Rt == 15) {
4107     switch (Inst.getOpcode()) {
4108     case ARM::t2LDRSHs:
4109       return MCDisassembler::Fail;
4110     case ARM::t2LDRHs:
4111       Inst.setOpcode(ARM::t2PLDWs);
4112       break;
4113     case ARM::t2LDRSBs:
4114       Inst.setOpcode(ARM::t2PLIs);
4115       break;
4116     default:
4117       break;
4118     }
4119   }
4120 
4121   switch (Inst.getOpcode()) {
4122     case ARM::t2PLDs:
4123       break;
4124     case ARM::t2PLIs:
4125       if (!hasV7Ops)
4126         return MCDisassembler::Fail;
4127       break;
4128     case ARM::t2PLDWs:
4129       if (!hasV7Ops || !hasMP)
4130         return MCDisassembler::Fail;
4131       break;
4132     default:
4133       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4134         return MCDisassembler::Fail;
4135   }
4136 
4137   unsigned addrmode = fieldFromInstruction(Insn, 4, 2);
4138   addrmode |= fieldFromInstruction(Insn, 0, 4) << 2;
4139   addrmode |= fieldFromInstruction(Insn, 16, 4) << 6;
4140   if (!Check(S, DecodeT2AddrModeSOReg(Inst, addrmode, Address, Decoder)))
4141     return MCDisassembler::Fail;
4142 
4143   return S;
4144 }
4145 
4146 static DecodeStatus DecodeT2LoadImm8(MCInst &Inst, unsigned Insn,
4147                                      uint64_t Address,
4148                                      const MCDisassembler *Decoder) {
4149   DecodeStatus S = MCDisassembler::Success;
4150 
4151   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4152   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4153   unsigned U = fieldFromInstruction(Insn, 9, 1);
4154   unsigned imm = fieldFromInstruction(Insn, 0, 8);
4155   imm |= (U << 8);
4156   imm |= (Rn << 9);
4157   unsigned add = fieldFromInstruction(Insn, 9, 1);
4158 
4159   const FeatureBitset &featureBits =
4160     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4161 
4162   bool hasMP = featureBits[ARM::FeatureMP];
4163   bool hasV7Ops = featureBits[ARM::HasV7Ops];
4164 
4165   if (Rn == 15) {
4166     switch (Inst.getOpcode()) {
4167     case ARM::t2LDRi8:
4168       Inst.setOpcode(ARM::t2LDRpci);
4169       break;
4170     case ARM::t2LDRBi8:
4171       Inst.setOpcode(ARM::t2LDRBpci);
4172       break;
4173     case ARM::t2LDRSBi8:
4174       Inst.setOpcode(ARM::t2LDRSBpci);
4175       break;
4176     case ARM::t2LDRHi8:
4177       Inst.setOpcode(ARM::t2LDRHpci);
4178       break;
4179     case ARM::t2LDRSHi8:
4180       Inst.setOpcode(ARM::t2LDRSHpci);
4181       break;
4182     case ARM::t2PLDi8:
4183       Inst.setOpcode(ARM::t2PLDpci);
4184       break;
4185     case ARM::t2PLIi8:
4186       Inst.setOpcode(ARM::t2PLIpci);
4187       break;
4188     default:
4189       return MCDisassembler::Fail;
4190     }
4191     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
4192   }
4193 
4194   if (Rt == 15) {
4195     switch (Inst.getOpcode()) {
4196     case ARM::t2LDRSHi8:
4197       return MCDisassembler::Fail;
4198     case ARM::t2LDRHi8:
4199       if (!add)
4200         Inst.setOpcode(ARM::t2PLDWi8);
4201       break;
4202     case ARM::t2LDRSBi8:
4203       Inst.setOpcode(ARM::t2PLIi8);
4204       break;
4205     default:
4206       break;
4207     }
4208   }
4209 
4210   switch (Inst.getOpcode()) {
4211   case ARM::t2PLDi8:
4212     break;
4213   case ARM::t2PLIi8:
4214     if (!hasV7Ops)
4215       return MCDisassembler::Fail;
4216     break;
4217   case ARM::t2PLDWi8:
4218       if (!hasV7Ops || !hasMP)
4219         return MCDisassembler::Fail;
4220       break;
4221   default:
4222     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4223       return MCDisassembler::Fail;
4224   }
4225 
4226   if (!Check(S, DecodeT2AddrModeImm8(Inst, imm, Address, Decoder)))
4227     return MCDisassembler::Fail;
4228   return S;
4229 }
4230 
4231 static DecodeStatus DecodeT2LoadImm12(MCInst &Inst, unsigned Insn,
4232                                       uint64_t Address,
4233                                       const MCDisassembler *Decoder) {
4234   DecodeStatus S = MCDisassembler::Success;
4235 
4236   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4237   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4238   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4239   imm |= (Rn << 13);
4240 
4241   const FeatureBitset &featureBits =
4242     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4243 
4244   bool hasMP = featureBits[ARM::FeatureMP];
4245   bool hasV7Ops = featureBits[ARM::HasV7Ops];
4246 
4247   if (Rn == 15) {
4248     switch (Inst.getOpcode()) {
4249     case ARM::t2LDRi12:
4250       Inst.setOpcode(ARM::t2LDRpci);
4251       break;
4252     case ARM::t2LDRHi12:
4253       Inst.setOpcode(ARM::t2LDRHpci);
4254       break;
4255     case ARM::t2LDRSHi12:
4256       Inst.setOpcode(ARM::t2LDRSHpci);
4257       break;
4258     case ARM::t2LDRBi12:
4259       Inst.setOpcode(ARM::t2LDRBpci);
4260       break;
4261     case ARM::t2LDRSBi12:
4262       Inst.setOpcode(ARM::t2LDRSBpci);
4263       break;
4264     case ARM::t2PLDi12:
4265       Inst.setOpcode(ARM::t2PLDpci);
4266       break;
4267     case ARM::t2PLIi12:
4268       Inst.setOpcode(ARM::t2PLIpci);
4269       break;
4270     default:
4271       return MCDisassembler::Fail;
4272     }
4273     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
4274   }
4275 
4276   if (Rt == 15) {
4277     switch (Inst.getOpcode()) {
4278     case ARM::t2LDRSHi12:
4279       return MCDisassembler::Fail;
4280     case ARM::t2LDRHi12:
4281       Inst.setOpcode(ARM::t2PLDWi12);
4282       break;
4283     case ARM::t2LDRSBi12:
4284       Inst.setOpcode(ARM::t2PLIi12);
4285       break;
4286     default:
4287       break;
4288     }
4289   }
4290 
4291   switch (Inst.getOpcode()) {
4292   case ARM::t2PLDi12:
4293     break;
4294   case ARM::t2PLIi12:
4295     if (!hasV7Ops)
4296       return MCDisassembler::Fail;
4297     break;
4298   case ARM::t2PLDWi12:
4299       if (!hasV7Ops || !hasMP)
4300         return MCDisassembler::Fail;
4301       break;
4302   default:
4303     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4304       return MCDisassembler::Fail;
4305   }
4306 
4307   if (!Check(S, DecodeT2AddrModeImm12(Inst, imm, Address, Decoder)))
4308     return MCDisassembler::Fail;
4309   return S;
4310 }
4311 
4312 static DecodeStatus DecodeT2LoadT(MCInst &Inst, unsigned Insn, uint64_t Address,
4313                                   const MCDisassembler *Decoder) {
4314   DecodeStatus S = MCDisassembler::Success;
4315 
4316   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4317   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4318   unsigned imm = fieldFromInstruction(Insn, 0, 8);
4319   imm |= (Rn << 9);
4320 
4321   if (Rn == 15) {
4322     switch (Inst.getOpcode()) {
4323     case ARM::t2LDRT:
4324       Inst.setOpcode(ARM::t2LDRpci);
4325       break;
4326     case ARM::t2LDRBT:
4327       Inst.setOpcode(ARM::t2LDRBpci);
4328       break;
4329     case ARM::t2LDRHT:
4330       Inst.setOpcode(ARM::t2LDRHpci);
4331       break;
4332     case ARM::t2LDRSBT:
4333       Inst.setOpcode(ARM::t2LDRSBpci);
4334       break;
4335     case ARM::t2LDRSHT:
4336       Inst.setOpcode(ARM::t2LDRSHpci);
4337       break;
4338     default:
4339       return MCDisassembler::Fail;
4340     }
4341     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
4342   }
4343 
4344   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
4345     return MCDisassembler::Fail;
4346   if (!Check(S, DecodeT2AddrModeImm8(Inst, imm, Address, Decoder)))
4347     return MCDisassembler::Fail;
4348   return S;
4349 }
4350 
4351 static DecodeStatus DecodeT2LoadLabel(MCInst &Inst, unsigned Insn,
4352                                       uint64_t Address,
4353                                       const MCDisassembler *Decoder) {
4354   DecodeStatus S = MCDisassembler::Success;
4355 
4356   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4357   unsigned U = fieldFromInstruction(Insn, 23, 1);
4358   int imm = fieldFromInstruction(Insn, 0, 12);
4359 
4360   const FeatureBitset &featureBits =
4361     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4362 
4363   bool hasV7Ops = featureBits[ARM::HasV7Ops];
4364 
4365   if (Rt == 15) {
4366     switch (Inst.getOpcode()) {
4367       case ARM::t2LDRBpci:
4368       case ARM::t2LDRHpci:
4369         Inst.setOpcode(ARM::t2PLDpci);
4370         break;
4371       case ARM::t2LDRSBpci:
4372         Inst.setOpcode(ARM::t2PLIpci);
4373         break;
4374       case ARM::t2LDRSHpci:
4375         return MCDisassembler::Fail;
4376       default:
4377         break;
4378     }
4379   }
4380 
4381   switch(Inst.getOpcode()) {
4382   case ARM::t2PLDpci:
4383     break;
4384   case ARM::t2PLIpci:
4385     if (!hasV7Ops)
4386       return MCDisassembler::Fail;
4387     break;
4388   default:
4389     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4390       return MCDisassembler::Fail;
4391   }
4392 
4393   if (!U) {
4394     // Special case for #-0.
4395     if (imm == 0)
4396       imm = INT32_MIN;
4397     else
4398       imm = -imm;
4399   }
4400   Inst.addOperand(MCOperand::createImm(imm));
4401 
4402   return S;
4403 }
4404 
4405 static DecodeStatus DecodeT2Imm8S4(MCInst &Inst, unsigned Val, uint64_t Address,
4406                                    const MCDisassembler *Decoder) {
4407   if (Val == 0)
4408     Inst.addOperand(MCOperand::createImm(INT32_MIN));
4409   else {
4410     int imm = Val & 0xFF;
4411 
4412     if (!(Val & 0x100)) imm *= -1;
4413     Inst.addOperand(MCOperand::createImm(imm * 4));
4414   }
4415 
4416   return MCDisassembler::Success;
4417 }
4418 
4419 static DecodeStatus DecodeT2Imm7S4(MCInst &Inst, unsigned Val, uint64_t Address,
4420                                    const MCDisassembler *Decoder) {
4421   if (Val == 0)
4422     Inst.addOperand(MCOperand::createImm(INT32_MIN));
4423   else {
4424     int imm = Val & 0x7F;
4425 
4426     if (!(Val & 0x80))
4427       imm *= -1;
4428     Inst.addOperand(MCOperand::createImm(imm * 4));
4429   }
4430 
4431   return MCDisassembler::Success;
4432 }
4433 
4434 static DecodeStatus DecodeT2AddrModeImm8s4(MCInst &Inst, unsigned Val,
4435                                            uint64_t Address,
4436                                            const MCDisassembler *Decoder) {
4437   DecodeStatus S = MCDisassembler::Success;
4438 
4439   unsigned Rn = fieldFromInstruction(Val, 9, 4);
4440   unsigned imm = fieldFromInstruction(Val, 0, 9);
4441 
4442   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4443     return MCDisassembler::Fail;
4444   if (!Check(S, DecodeT2Imm8S4(Inst, imm, Address, Decoder)))
4445     return MCDisassembler::Fail;
4446 
4447   return S;
4448 }
4449 
4450 static DecodeStatus DecodeT2AddrModeImm7s4(MCInst &Inst, unsigned Val,
4451                                            uint64_t Address,
4452                                            const MCDisassembler *Decoder) {
4453   DecodeStatus S = MCDisassembler::Success;
4454 
4455   unsigned Rn = fieldFromInstruction(Val, 8, 4);
4456   unsigned imm = fieldFromInstruction(Val, 0, 8);
4457 
4458   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4459     return MCDisassembler::Fail;
4460   if (!Check(S, DecodeT2Imm7S4(Inst, imm, Address, Decoder)))
4461     return MCDisassembler::Fail;
4462 
4463   return S;
4464 }
4465 
4466 static DecodeStatus DecodeT2AddrModeImm0_1020s4(MCInst &Inst, unsigned Val,
4467                                                 uint64_t Address,
4468                                                 const MCDisassembler *Decoder) {
4469   DecodeStatus S = MCDisassembler::Success;
4470 
4471   unsigned Rn = fieldFromInstruction(Val, 8, 4);
4472   unsigned imm = fieldFromInstruction(Val, 0, 8);
4473 
4474   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4475     return MCDisassembler::Fail;
4476 
4477   Inst.addOperand(MCOperand::createImm(imm));
4478 
4479   return S;
4480 }
4481 
4482 static DecodeStatus DecodeT2Imm8(MCInst &Inst, unsigned Val, uint64_t Address,
4483                                  const MCDisassembler *Decoder) {
4484   int imm = Val & 0xFF;
4485   if (Val == 0)
4486     imm = INT32_MIN;
4487   else if (!(Val & 0x100))
4488     imm *= -1;
4489   Inst.addOperand(MCOperand::createImm(imm));
4490 
4491   return MCDisassembler::Success;
4492 }
4493 
4494 template <int shift>
4495 static DecodeStatus DecodeT2Imm7(MCInst &Inst, unsigned Val, uint64_t Address,
4496                                  const MCDisassembler *Decoder) {
4497   int imm = Val & 0x7F;
4498   if (Val == 0)
4499     imm = INT32_MIN;
4500   else if (!(Val & 0x80))
4501     imm *= -1;
4502   if (imm != INT32_MIN)
4503     imm *= (1U << shift);
4504   Inst.addOperand(MCOperand::createImm(imm));
4505 
4506   return MCDisassembler::Success;
4507 }
4508 
4509 static DecodeStatus DecodeT2AddrModeImm8(MCInst &Inst, unsigned Val,
4510                                          uint64_t Address,
4511                                          const MCDisassembler *Decoder) {
4512   DecodeStatus S = MCDisassembler::Success;
4513 
4514   unsigned Rn = fieldFromInstruction(Val, 9, 4);
4515   unsigned imm = fieldFromInstruction(Val, 0, 9);
4516 
4517   // Thumb stores cannot use PC as dest register.
4518   switch (Inst.getOpcode()) {
4519   case ARM::t2STRT:
4520   case ARM::t2STRBT:
4521   case ARM::t2STRHT:
4522   case ARM::t2STRi8:
4523   case ARM::t2STRHi8:
4524   case ARM::t2STRBi8:
4525     if (Rn == 15)
4526       return MCDisassembler::Fail;
4527     break;
4528   default:
4529     break;
4530   }
4531 
4532   // Some instructions always use an additive offset.
4533   switch (Inst.getOpcode()) {
4534     case ARM::t2LDRT:
4535     case ARM::t2LDRBT:
4536     case ARM::t2LDRHT:
4537     case ARM::t2LDRSBT:
4538     case ARM::t2LDRSHT:
4539     case ARM::t2STRT:
4540     case ARM::t2STRBT:
4541     case ARM::t2STRHT:
4542       imm |= 0x100;
4543       break;
4544     default:
4545       break;
4546   }
4547 
4548   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4549     return MCDisassembler::Fail;
4550   if (!Check(S, DecodeT2Imm8(Inst, imm, Address, Decoder)))
4551     return MCDisassembler::Fail;
4552 
4553   return S;
4554 }
4555 
4556 template <int shift>
4557 static DecodeStatus DecodeTAddrModeImm7(MCInst &Inst, unsigned Val,
4558                                         uint64_t Address,
4559                                         const MCDisassembler *Decoder) {
4560   DecodeStatus S = MCDisassembler::Success;
4561 
4562   unsigned Rn = fieldFromInstruction(Val, 8, 3);
4563   unsigned imm = fieldFromInstruction(Val, 0, 8);
4564 
4565   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
4566     return MCDisassembler::Fail;
4567   if (!Check(S, DecodeT2Imm7<shift>(Inst, imm, Address, Decoder)))
4568     return MCDisassembler::Fail;
4569 
4570   return S;
4571 }
4572 
4573 template <int shift, int WriteBack>
4574 static DecodeStatus DecodeT2AddrModeImm7(MCInst &Inst, unsigned Val,
4575                                          uint64_t Address,
4576                                          const MCDisassembler *Decoder) {
4577   DecodeStatus S = MCDisassembler::Success;
4578 
4579   unsigned Rn = fieldFromInstruction(Val, 8, 4);
4580   unsigned imm = fieldFromInstruction(Val, 0, 8);
4581   if (WriteBack) {
4582     if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
4583       return MCDisassembler::Fail;
4584   } else if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4585     return MCDisassembler::Fail;
4586   if (!Check(S, DecodeT2Imm7<shift>(Inst, imm, Address, Decoder)))
4587     return MCDisassembler::Fail;
4588 
4589   return S;
4590 }
4591 
4592 static DecodeStatus DecodeT2LdStPre(MCInst &Inst, unsigned Insn,
4593                                     uint64_t Address,
4594                                     const MCDisassembler *Decoder) {
4595   DecodeStatus S = MCDisassembler::Success;
4596 
4597   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4598   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4599   unsigned addr = fieldFromInstruction(Insn, 0, 8);
4600   addr |= fieldFromInstruction(Insn, 9, 1) << 8;
4601   addr |= Rn << 9;
4602   unsigned load = fieldFromInstruction(Insn, 20, 1);
4603 
4604   if (Rn == 15) {
4605     switch (Inst.getOpcode()) {
4606     case ARM::t2LDR_PRE:
4607     case ARM::t2LDR_POST:
4608       Inst.setOpcode(ARM::t2LDRpci);
4609       break;
4610     case ARM::t2LDRB_PRE:
4611     case ARM::t2LDRB_POST:
4612       Inst.setOpcode(ARM::t2LDRBpci);
4613       break;
4614     case ARM::t2LDRH_PRE:
4615     case ARM::t2LDRH_POST:
4616       Inst.setOpcode(ARM::t2LDRHpci);
4617       break;
4618     case ARM::t2LDRSB_PRE:
4619     case ARM::t2LDRSB_POST:
4620       if (Rt == 15)
4621         Inst.setOpcode(ARM::t2PLIpci);
4622       else
4623         Inst.setOpcode(ARM::t2LDRSBpci);
4624       break;
4625     case ARM::t2LDRSH_PRE:
4626     case ARM::t2LDRSH_POST:
4627       Inst.setOpcode(ARM::t2LDRSHpci);
4628       break;
4629     default:
4630       return MCDisassembler::Fail;
4631     }
4632     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
4633   }
4634 
4635   if (!load) {
4636     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4637       return MCDisassembler::Fail;
4638   }
4639 
4640   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4641     return MCDisassembler::Fail;
4642 
4643   if (load) {
4644     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4645       return MCDisassembler::Fail;
4646   }
4647 
4648   if (!Check(S, DecodeT2AddrModeImm8(Inst, addr, Address, Decoder)))
4649     return MCDisassembler::Fail;
4650 
4651   return S;
4652 }
4653 
4654 static DecodeStatus DecodeT2AddrModeImm12(MCInst &Inst, unsigned Val,
4655                                           uint64_t Address,
4656                                           const MCDisassembler *Decoder) {
4657   DecodeStatus S = MCDisassembler::Success;
4658 
4659   unsigned Rn = fieldFromInstruction(Val, 13, 4);
4660   unsigned imm = fieldFromInstruction(Val, 0, 12);
4661 
4662   // Thumb stores cannot use PC as dest register.
4663   switch (Inst.getOpcode()) {
4664   case ARM::t2STRi12:
4665   case ARM::t2STRBi12:
4666   case ARM::t2STRHi12:
4667     if (Rn == 15)
4668       return MCDisassembler::Fail;
4669     break;
4670   default:
4671     break;
4672   }
4673 
4674   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4675     return MCDisassembler::Fail;
4676   Inst.addOperand(MCOperand::createImm(imm));
4677 
4678   return S;
4679 }
4680 
4681 static DecodeStatus DecodeThumbAddSPImm(MCInst &Inst, uint16_t Insn,
4682                                         uint64_t Address,
4683                                         const MCDisassembler *Decoder) {
4684   unsigned imm = fieldFromInstruction(Insn, 0, 7);
4685 
4686   Inst.addOperand(MCOperand::createReg(ARM::SP));
4687   Inst.addOperand(MCOperand::createReg(ARM::SP));
4688   Inst.addOperand(MCOperand::createImm(imm));
4689 
4690   return MCDisassembler::Success;
4691 }
4692 
4693 static DecodeStatus DecodeThumbAddSPReg(MCInst &Inst, uint16_t Insn,
4694                                         uint64_t Address,
4695                                         const MCDisassembler *Decoder) {
4696   DecodeStatus S = MCDisassembler::Success;
4697 
4698   if (Inst.getOpcode() == ARM::tADDrSP) {
4699     unsigned Rdm = fieldFromInstruction(Insn, 0, 3);
4700     Rdm |= fieldFromInstruction(Insn, 7, 1) << 3;
4701 
4702     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
4703     return MCDisassembler::Fail;
4704     Inst.addOperand(MCOperand::createReg(ARM::SP));
4705     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
4706     return MCDisassembler::Fail;
4707   } else if (Inst.getOpcode() == ARM::tADDspr) {
4708     unsigned Rm = fieldFromInstruction(Insn, 3, 4);
4709 
4710     Inst.addOperand(MCOperand::createReg(ARM::SP));
4711     Inst.addOperand(MCOperand::createReg(ARM::SP));
4712     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4713     return MCDisassembler::Fail;
4714   }
4715 
4716   return S;
4717 }
4718 
4719 static DecodeStatus DecodeThumbCPS(MCInst &Inst, uint16_t Insn,
4720                                    uint64_t Address,
4721                                    const MCDisassembler *Decoder) {
4722   unsigned imod = fieldFromInstruction(Insn, 4, 1) | 0x2;
4723   unsigned flags = fieldFromInstruction(Insn, 0, 3);
4724 
4725   Inst.addOperand(MCOperand::createImm(imod));
4726   Inst.addOperand(MCOperand::createImm(flags));
4727 
4728   return MCDisassembler::Success;
4729 }
4730 
4731 static DecodeStatus DecodePostIdxReg(MCInst &Inst, unsigned Insn,
4732                                      uint64_t Address,
4733                                      const MCDisassembler *Decoder) {
4734   DecodeStatus S = MCDisassembler::Success;
4735   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4736   unsigned add = fieldFromInstruction(Insn, 4, 1);
4737 
4738   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
4739     return MCDisassembler::Fail;
4740   Inst.addOperand(MCOperand::createImm(add));
4741 
4742   return S;
4743 }
4744 
4745 static DecodeStatus DecodeMveAddrModeRQ(MCInst &Inst, unsigned Insn,
4746                                         uint64_t Address,
4747                                         const MCDisassembler *Decoder) {
4748   DecodeStatus S = MCDisassembler::Success;
4749   unsigned Rn = fieldFromInstruction(Insn, 3, 4);
4750   unsigned Qm = fieldFromInstruction(Insn, 0, 3);
4751 
4752   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4753     return MCDisassembler::Fail;
4754   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
4755     return MCDisassembler::Fail;
4756 
4757   return S;
4758 }
4759 
4760 template <int shift>
4761 static DecodeStatus DecodeMveAddrModeQ(MCInst &Inst, unsigned Insn,
4762                                        uint64_t Address,
4763                                        const MCDisassembler *Decoder) {
4764   DecodeStatus S = MCDisassembler::Success;
4765   unsigned Qm = fieldFromInstruction(Insn, 8, 3);
4766   int imm = fieldFromInstruction(Insn, 0, 7);
4767 
4768   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
4769     return MCDisassembler::Fail;
4770 
4771   if(!fieldFromInstruction(Insn, 7, 1)) {
4772     if (imm == 0)
4773       imm = INT32_MIN;                 // indicate -0
4774     else
4775       imm *= -1;
4776   }
4777   if (imm != INT32_MIN)
4778     imm *= (1U << shift);
4779   Inst.addOperand(MCOperand::createImm(imm));
4780 
4781   return S;
4782 }
4783 
4784 static DecodeStatus DecodeThumbBLXOffset(MCInst &Inst, unsigned Val,
4785                                          uint64_t Address,
4786                                          const MCDisassembler *Decoder) {
4787   // Val is passed in as S:J1:J2:imm10H:imm10L:'0'
4788   // Note only one trailing zero not two.  Also the J1 and J2 values are from
4789   // the encoded instruction.  So here change to I1 and I2 values via:
4790   // I1 = NOT(J1 EOR S);
4791   // I2 = NOT(J2 EOR S);
4792   // and build the imm32 with two trailing zeros as documented:
4793   // imm32 = SignExtend(S:I1:I2:imm10H:imm10L:'00', 32);
4794   unsigned S = (Val >> 23) & 1;
4795   unsigned J1 = (Val >> 22) & 1;
4796   unsigned J2 = (Val >> 21) & 1;
4797   unsigned I1 = !(J1 ^ S);
4798   unsigned I2 = !(J2 ^ S);
4799   unsigned tmp = (Val & ~0x600000) | (I1 << 22) | (I2 << 21);
4800   int imm32 = SignExtend32<25>(tmp << 1);
4801 
4802   if (!tryAddingSymbolicOperand(Address,
4803                                 (Address & ~2u) + imm32 + 4,
4804                                 true, 4, Inst, Decoder))
4805     Inst.addOperand(MCOperand::createImm(imm32));
4806   return MCDisassembler::Success;
4807 }
4808 
4809 static DecodeStatus DecodeCoprocessor(MCInst &Inst, unsigned Val,
4810                                       uint64_t Address,
4811                                       const MCDisassembler *Decoder) {
4812   if (Val == 0xA || Val == 0xB)
4813     return MCDisassembler::Fail;
4814 
4815   const FeatureBitset &featureBits =
4816     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4817 
4818   if (!isValidCoprocessorNumber(Val, featureBits))
4819     return MCDisassembler::Fail;
4820 
4821   Inst.addOperand(MCOperand::createImm(Val));
4822   return MCDisassembler::Success;
4823 }
4824 
4825 static DecodeStatus DecodeThumbTableBranch(MCInst &Inst, unsigned Insn,
4826                                            uint64_t Address,
4827                                            const MCDisassembler *Decoder) {
4828   const FeatureBitset &FeatureBits =
4829     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4830   DecodeStatus S = MCDisassembler::Success;
4831 
4832   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4833   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4834 
4835   if (Rn == 13 && !FeatureBits[ARM::HasV8Ops]) S = MCDisassembler::SoftFail;
4836   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4837     return MCDisassembler::Fail;
4838   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
4839     return MCDisassembler::Fail;
4840   return S;
4841 }
4842 
4843 static DecodeStatus DecodeThumb2BCCInstruction(MCInst &Inst, unsigned Insn,
4844                                                uint64_t Address,
4845                                                const MCDisassembler *Decoder) {
4846   DecodeStatus S = MCDisassembler::Success;
4847 
4848   unsigned pred = fieldFromInstruction(Insn, 22, 4);
4849   if (pred == 0xE || pred == 0xF) {
4850     unsigned opc = fieldFromInstruction(Insn, 4, 28);
4851     switch (opc) {
4852       default:
4853         return MCDisassembler::Fail;
4854       case 0xf3bf8f4:
4855         Inst.setOpcode(ARM::t2DSB);
4856         break;
4857       case 0xf3bf8f5:
4858         Inst.setOpcode(ARM::t2DMB);
4859         break;
4860       case 0xf3bf8f6:
4861         Inst.setOpcode(ARM::t2ISB);
4862         break;
4863     }
4864 
4865     unsigned imm = fieldFromInstruction(Insn, 0, 4);
4866     return DecodeMemBarrierOption(Inst, imm, Address, Decoder);
4867   }
4868 
4869   unsigned brtarget = fieldFromInstruction(Insn, 0, 11) << 1;
4870   brtarget |= fieldFromInstruction(Insn, 11, 1) << 19;
4871   brtarget |= fieldFromInstruction(Insn, 13, 1) << 18;
4872   brtarget |= fieldFromInstruction(Insn, 16, 6) << 12;
4873   brtarget |= fieldFromInstruction(Insn, 26, 1) << 20;
4874 
4875   if (!Check(S, DecodeT2BROperand(Inst, brtarget, Address, Decoder)))
4876     return MCDisassembler::Fail;
4877   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4878     return MCDisassembler::Fail;
4879 
4880   return S;
4881 }
4882 
4883 // Decode a shifted immediate operand.  These basically consist
4884 // of an 8-bit value, and a 4-bit directive that specifies either
4885 // a splat operation or a rotation.
4886 static DecodeStatus DecodeT2SOImm(MCInst &Inst, unsigned Val, uint64_t Address,
4887                                   const MCDisassembler *Decoder) {
4888   unsigned ctrl = fieldFromInstruction(Val, 10, 2);
4889   if (ctrl == 0) {
4890     unsigned byte = fieldFromInstruction(Val, 8, 2);
4891     unsigned imm = fieldFromInstruction(Val, 0, 8);
4892     switch (byte) {
4893       case 0:
4894         Inst.addOperand(MCOperand::createImm(imm));
4895         break;
4896       case 1:
4897         Inst.addOperand(MCOperand::createImm((imm << 16) | imm));
4898         break;
4899       case 2:
4900         Inst.addOperand(MCOperand::createImm((imm << 24) | (imm << 8)));
4901         break;
4902       case 3:
4903         Inst.addOperand(MCOperand::createImm((imm << 24) | (imm << 16) |
4904                                              (imm << 8)  |  imm));
4905         break;
4906     }
4907   } else {
4908     unsigned unrot = fieldFromInstruction(Val, 0, 7) | 0x80;
4909     unsigned rot = fieldFromInstruction(Val, 7, 5);
4910     unsigned imm = (unrot >> rot) | (unrot << ((32-rot)&31));
4911     Inst.addOperand(MCOperand::createImm(imm));
4912   }
4913 
4914   return MCDisassembler::Success;
4915 }
4916 
4917 static DecodeStatus DecodeThumbBCCTargetOperand(MCInst &Inst, unsigned Val,
4918                                                 uint64_t Address,
4919                                                 const MCDisassembler *Decoder) {
4920   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<9>(Val<<1) + 4,
4921                                 true, 2, Inst, Decoder))
4922     Inst.addOperand(MCOperand::createImm(SignExtend32<9>(Val << 1)));
4923   return MCDisassembler::Success;
4924 }
4925 
4926 static DecodeStatus DecodeThumbBLTargetOperand(MCInst &Inst, unsigned Val,
4927                                                uint64_t Address,
4928                                                const MCDisassembler *Decoder) {
4929   // Val is passed in as S:J1:J2:imm10:imm11
4930   // Note no trailing zero after imm11.  Also the J1 and J2 values are from
4931   // the encoded instruction.  So here change to I1 and I2 values via:
4932   // I1 = NOT(J1 EOR S);
4933   // I2 = NOT(J2 EOR S);
4934   // and build the imm32 with one trailing zero as documented:
4935   // imm32 = SignExtend(S:I1:I2:imm10:imm11:'0', 32);
4936   unsigned S = (Val >> 23) & 1;
4937   unsigned J1 = (Val >> 22) & 1;
4938   unsigned J2 = (Val >> 21) & 1;
4939   unsigned I1 = !(J1 ^ S);
4940   unsigned I2 = !(J2 ^ S);
4941   unsigned tmp = (Val & ~0x600000) | (I1 << 22) | (I2 << 21);
4942   int imm32 = SignExtend32<25>(tmp << 1);
4943 
4944   if (!tryAddingSymbolicOperand(Address, Address + imm32 + 4,
4945                                 true, 4, Inst, Decoder))
4946     Inst.addOperand(MCOperand::createImm(imm32));
4947   return MCDisassembler::Success;
4948 }
4949 
4950 static DecodeStatus DecodeMemBarrierOption(MCInst &Inst, unsigned Val,
4951                                            uint64_t Address,
4952                                            const MCDisassembler *Decoder) {
4953   if (Val & ~0xf)
4954     return MCDisassembler::Fail;
4955 
4956   Inst.addOperand(MCOperand::createImm(Val));
4957   return MCDisassembler::Success;
4958 }
4959 
4960 static DecodeStatus DecodeInstSyncBarrierOption(MCInst &Inst, unsigned Val,
4961                                                 uint64_t Address,
4962                                                 const MCDisassembler *Decoder) {
4963   if (Val & ~0xf)
4964     return MCDisassembler::Fail;
4965 
4966   Inst.addOperand(MCOperand::createImm(Val));
4967   return MCDisassembler::Success;
4968 }
4969 
4970 static DecodeStatus DecodeMSRMask(MCInst &Inst, unsigned Val, uint64_t Address,
4971                                   const MCDisassembler *Decoder) {
4972   DecodeStatus S = MCDisassembler::Success;
4973   const FeatureBitset &FeatureBits =
4974     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4975 
4976   if (FeatureBits[ARM::FeatureMClass]) {
4977     unsigned ValLow = Val & 0xff;
4978 
4979     // Validate the SYSm value first.
4980     switch (ValLow) {
4981     case  0: // apsr
4982     case  1: // iapsr
4983     case  2: // eapsr
4984     case  3: // xpsr
4985     case  5: // ipsr
4986     case  6: // epsr
4987     case  7: // iepsr
4988     case  8: // msp
4989     case  9: // psp
4990     case 16: // primask
4991     case 20: // control
4992       break;
4993     case 17: // basepri
4994     case 18: // basepri_max
4995     case 19: // faultmask
4996       if (!(FeatureBits[ARM::HasV7Ops]))
4997         // Values basepri, basepri_max and faultmask are only valid for v7m.
4998         return MCDisassembler::Fail;
4999       break;
5000     case 0x8a: // msplim_ns
5001     case 0x8b: // psplim_ns
5002     case 0x91: // basepri_ns
5003     case 0x93: // faultmask_ns
5004       if (!(FeatureBits[ARM::HasV8MMainlineOps]))
5005         return MCDisassembler::Fail;
5006       [[fallthrough]];
5007     case 10:   // msplim
5008     case 11:   // psplim
5009     case 0x88: // msp_ns
5010     case 0x89: // psp_ns
5011     case 0x90: // primask_ns
5012     case 0x94: // control_ns
5013     case 0x98: // sp_ns
5014       if (!(FeatureBits[ARM::Feature8MSecExt]))
5015         return MCDisassembler::Fail;
5016       break;
5017     case 0x20: // pac_key_p_0
5018     case 0x21: // pac_key_p_1
5019     case 0x22: // pac_key_p_2
5020     case 0x23: // pac_key_p_3
5021     case 0x24: // pac_key_u_0
5022     case 0x25: // pac_key_u_1
5023     case 0x26: // pac_key_u_2
5024     case 0x27: // pac_key_u_3
5025     case 0xa0: // pac_key_p_0_ns
5026     case 0xa1: // pac_key_p_1_ns
5027     case 0xa2: // pac_key_p_2_ns
5028     case 0xa3: // pac_key_p_3_ns
5029     case 0xa4: // pac_key_u_0_ns
5030     case 0xa5: // pac_key_u_1_ns
5031     case 0xa6: // pac_key_u_2_ns
5032     case 0xa7: // pac_key_u_3_ns
5033       if (!(FeatureBits[ARM::FeaturePACBTI]))
5034         return MCDisassembler::Fail;
5035       break;
5036     default:
5037       // Architecturally defined as unpredictable
5038       S = MCDisassembler::SoftFail;
5039       break;
5040     }
5041 
5042     if (Inst.getOpcode() == ARM::t2MSR_M) {
5043       unsigned Mask = fieldFromInstruction(Val, 10, 2);
5044       if (!(FeatureBits[ARM::HasV7Ops])) {
5045         // The ARMv6-M MSR bits {11-10} can be only 0b10, other values are
5046         // unpredictable.
5047         if (Mask != 2)
5048           S = MCDisassembler::SoftFail;
5049       }
5050       else {
5051         // The ARMv7-M architecture stores an additional 2-bit mask value in
5052         // MSR bits {11-10}. The mask is used only with apsr, iapsr, eapsr and
5053         // xpsr, it has to be 0b10 in other cases. Bit mask{1} indicates if
5054         // the NZCVQ bits should be moved by the instruction. Bit mask{0}
5055         // indicates the move for the GE{3:0} bits, the mask{0} bit can be set
5056         // only if the processor includes the DSP extension.
5057         if (Mask == 0 || (Mask != 2 && ValLow > 3) ||
5058             (!(FeatureBits[ARM::FeatureDSP]) && (Mask & 1)))
5059           S = MCDisassembler::SoftFail;
5060       }
5061     }
5062   } else {
5063     // A/R class
5064     if (Val == 0)
5065       return MCDisassembler::Fail;
5066   }
5067   Inst.addOperand(MCOperand::createImm(Val));
5068   return S;
5069 }
5070 
5071 static DecodeStatus DecodeBankedReg(MCInst &Inst, unsigned Val,
5072                                     uint64_t Address,
5073                                     const MCDisassembler *Decoder) {
5074   unsigned R = fieldFromInstruction(Val, 5, 1);
5075   unsigned SysM = fieldFromInstruction(Val, 0, 5);
5076 
5077   // The table of encodings for these banked registers comes from B9.2.3 of the
5078   // ARM ARM. There are patterns, but nothing regular enough to make this logic
5079   // neater. So by fiat, these values are UNPREDICTABLE:
5080   if (!ARMBankedReg::lookupBankedRegByEncoding((R << 5) | SysM))
5081     return MCDisassembler::Fail;
5082 
5083   Inst.addOperand(MCOperand::createImm(Val));
5084   return MCDisassembler::Success;
5085 }
5086 
5087 static DecodeStatus DecodeDoubleRegLoad(MCInst &Inst, unsigned Insn,
5088                                         uint64_t Address,
5089                                         const MCDisassembler *Decoder) {
5090   DecodeStatus S = MCDisassembler::Success;
5091 
5092   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5093   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5094   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5095 
5096   if (Rn == 0xF)
5097     S = MCDisassembler::SoftFail;
5098 
5099   if (!Check(S, DecodeGPRPairRegisterClass(Inst, Rt, Address, Decoder)))
5100     return MCDisassembler::Fail;
5101   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5102     return MCDisassembler::Fail;
5103   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5104     return MCDisassembler::Fail;
5105 
5106   return S;
5107 }
5108 
5109 static DecodeStatus DecodeDoubleRegStore(MCInst &Inst, unsigned Insn,
5110                                          uint64_t Address,
5111                                          const MCDisassembler *Decoder) {
5112   DecodeStatus S = MCDisassembler::Success;
5113 
5114   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5115   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
5116   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5117   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5118 
5119   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
5120     return MCDisassembler::Fail;
5121 
5122   if (Rn == 0xF || Rd == Rn || Rd == Rt || Rd == Rt+1)
5123     S = MCDisassembler::SoftFail;
5124 
5125   if (!Check(S, DecodeGPRPairRegisterClass(Inst, Rt, Address, Decoder)))
5126     return MCDisassembler::Fail;
5127   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5128     return MCDisassembler::Fail;
5129   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5130     return MCDisassembler::Fail;
5131 
5132   return S;
5133 }
5134 
5135 static DecodeStatus DecodeLDRPreImm(MCInst &Inst, unsigned Insn,
5136                                     uint64_t Address,
5137                                     const MCDisassembler *Decoder) {
5138   DecodeStatus S = MCDisassembler::Success;
5139 
5140   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5141   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5142   unsigned imm = fieldFromInstruction(Insn, 0, 12);
5143   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
5144   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
5145   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5146 
5147   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
5148 
5149   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
5150     return MCDisassembler::Fail;
5151   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5152     return MCDisassembler::Fail;
5153   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
5154     return MCDisassembler::Fail;
5155   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5156     return MCDisassembler::Fail;
5157 
5158   return S;
5159 }
5160 
5161 static DecodeStatus DecodeLDRPreReg(MCInst &Inst, unsigned Insn,
5162                                     uint64_t Address,
5163                                     const MCDisassembler *Decoder) {
5164   DecodeStatus S = MCDisassembler::Success;
5165 
5166   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5167   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5168   unsigned imm = fieldFromInstruction(Insn, 0, 12);
5169   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
5170   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
5171   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5172   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5173 
5174   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
5175   if (Rm == 0xF) S = MCDisassembler::SoftFail;
5176 
5177   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
5178     return MCDisassembler::Fail;
5179   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5180     return MCDisassembler::Fail;
5181   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
5182     return MCDisassembler::Fail;
5183   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5184     return MCDisassembler::Fail;
5185 
5186   return S;
5187 }
5188 
5189 static DecodeStatus DecodeSTRPreImm(MCInst &Inst, unsigned Insn,
5190                                     uint64_t Address,
5191                                     const MCDisassembler *Decoder) {
5192   DecodeStatus S = MCDisassembler::Success;
5193 
5194   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5195   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5196   unsigned imm = fieldFromInstruction(Insn, 0, 12);
5197   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
5198   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
5199   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5200 
5201   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
5202 
5203   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5204     return MCDisassembler::Fail;
5205   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
5206     return MCDisassembler::Fail;
5207   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
5208     return MCDisassembler::Fail;
5209   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5210     return MCDisassembler::Fail;
5211 
5212   return S;
5213 }
5214 
5215 static DecodeStatus DecodeSTRPreReg(MCInst &Inst, unsigned Insn,
5216                                     uint64_t Address,
5217                                     const MCDisassembler *Decoder) {
5218   DecodeStatus S = MCDisassembler::Success;
5219 
5220   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5221   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5222   unsigned imm = fieldFromInstruction(Insn, 0, 12);
5223   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
5224   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
5225   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5226 
5227   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
5228 
5229   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5230     return MCDisassembler::Fail;
5231   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
5232     return MCDisassembler::Fail;
5233   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
5234     return MCDisassembler::Fail;
5235   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5236     return MCDisassembler::Fail;
5237 
5238   return S;
5239 }
5240 
5241 static DecodeStatus DecodeVLD1LN(MCInst &Inst, unsigned Insn, uint64_t Address,
5242                                  const MCDisassembler *Decoder) {
5243   DecodeStatus S = MCDisassembler::Success;
5244 
5245   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5246   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5247   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5248   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5249   unsigned size = fieldFromInstruction(Insn, 10, 2);
5250 
5251   unsigned align = 0;
5252   unsigned index = 0;
5253   switch (size) {
5254     default:
5255       return MCDisassembler::Fail;
5256     case 0:
5257       if (fieldFromInstruction(Insn, 4, 1))
5258         return MCDisassembler::Fail; // UNDEFINED
5259       index = fieldFromInstruction(Insn, 5, 3);
5260       break;
5261     case 1:
5262       if (fieldFromInstruction(Insn, 5, 1))
5263         return MCDisassembler::Fail; // UNDEFINED
5264       index = fieldFromInstruction(Insn, 6, 2);
5265       if (fieldFromInstruction(Insn, 4, 1))
5266         align = 2;
5267       break;
5268     case 2:
5269       if (fieldFromInstruction(Insn, 6, 1))
5270         return MCDisassembler::Fail; // UNDEFINED
5271       index = fieldFromInstruction(Insn, 7, 1);
5272 
5273       switch (fieldFromInstruction(Insn, 4, 2)) {
5274         case 0 :
5275           align = 0; break;
5276         case 3:
5277           align = 4; break;
5278         default:
5279           return MCDisassembler::Fail;
5280       }
5281       break;
5282   }
5283 
5284   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5285     return MCDisassembler::Fail;
5286   if (Rm != 0xF) { // Writeback
5287     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5288       return MCDisassembler::Fail;
5289   }
5290   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5291     return MCDisassembler::Fail;
5292   Inst.addOperand(MCOperand::createImm(align));
5293   if (Rm != 0xF) {
5294     if (Rm != 0xD) {
5295       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5296         return MCDisassembler::Fail;
5297     } else
5298       Inst.addOperand(MCOperand::createReg(0));
5299   }
5300 
5301   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5302     return MCDisassembler::Fail;
5303   Inst.addOperand(MCOperand::createImm(index));
5304 
5305   return S;
5306 }
5307 
5308 static DecodeStatus DecodeVST1LN(MCInst &Inst, unsigned Insn, uint64_t Address,
5309                                  const MCDisassembler *Decoder) {
5310   DecodeStatus S = MCDisassembler::Success;
5311 
5312   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5313   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5314   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5315   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5316   unsigned size = fieldFromInstruction(Insn, 10, 2);
5317 
5318   unsigned align = 0;
5319   unsigned index = 0;
5320   switch (size) {
5321     default:
5322       return MCDisassembler::Fail;
5323     case 0:
5324       if (fieldFromInstruction(Insn, 4, 1))
5325         return MCDisassembler::Fail; // UNDEFINED
5326       index = fieldFromInstruction(Insn, 5, 3);
5327       break;
5328     case 1:
5329       if (fieldFromInstruction(Insn, 5, 1))
5330         return MCDisassembler::Fail; // UNDEFINED
5331       index = fieldFromInstruction(Insn, 6, 2);
5332       if (fieldFromInstruction(Insn, 4, 1))
5333         align = 2;
5334       break;
5335     case 2:
5336       if (fieldFromInstruction(Insn, 6, 1))
5337         return MCDisassembler::Fail; // UNDEFINED
5338       index = fieldFromInstruction(Insn, 7, 1);
5339 
5340       switch (fieldFromInstruction(Insn, 4, 2)) {
5341         case 0:
5342           align = 0; break;
5343         case 3:
5344           align = 4; break;
5345         default:
5346           return MCDisassembler::Fail;
5347       }
5348       break;
5349   }
5350 
5351   if (Rm != 0xF) { // Writeback
5352     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5353     return MCDisassembler::Fail;
5354   }
5355   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5356     return MCDisassembler::Fail;
5357   Inst.addOperand(MCOperand::createImm(align));
5358   if (Rm != 0xF) {
5359     if (Rm != 0xD) {
5360       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5361     return MCDisassembler::Fail;
5362     } else
5363       Inst.addOperand(MCOperand::createReg(0));
5364   }
5365 
5366   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5367     return MCDisassembler::Fail;
5368   Inst.addOperand(MCOperand::createImm(index));
5369 
5370   return S;
5371 }
5372 
5373 static DecodeStatus DecodeVLD2LN(MCInst &Inst, unsigned Insn, uint64_t Address,
5374                                  const MCDisassembler *Decoder) {
5375   DecodeStatus S = MCDisassembler::Success;
5376 
5377   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5378   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5379   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5380   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5381   unsigned size = fieldFromInstruction(Insn, 10, 2);
5382 
5383   unsigned align = 0;
5384   unsigned index = 0;
5385   unsigned inc = 1;
5386   switch (size) {
5387     default:
5388       return MCDisassembler::Fail;
5389     case 0:
5390       index = fieldFromInstruction(Insn, 5, 3);
5391       if (fieldFromInstruction(Insn, 4, 1))
5392         align = 2;
5393       break;
5394     case 1:
5395       index = fieldFromInstruction(Insn, 6, 2);
5396       if (fieldFromInstruction(Insn, 4, 1))
5397         align = 4;
5398       if (fieldFromInstruction(Insn, 5, 1))
5399         inc = 2;
5400       break;
5401     case 2:
5402       if (fieldFromInstruction(Insn, 5, 1))
5403         return MCDisassembler::Fail; // UNDEFINED
5404       index = fieldFromInstruction(Insn, 7, 1);
5405       if (fieldFromInstruction(Insn, 4, 1) != 0)
5406         align = 8;
5407       if (fieldFromInstruction(Insn, 6, 1))
5408         inc = 2;
5409       break;
5410   }
5411 
5412   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5413     return MCDisassembler::Fail;
5414   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5415     return MCDisassembler::Fail;
5416   if (Rm != 0xF) { // Writeback
5417     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5418       return MCDisassembler::Fail;
5419   }
5420   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5421     return MCDisassembler::Fail;
5422   Inst.addOperand(MCOperand::createImm(align));
5423   if (Rm != 0xF) {
5424     if (Rm != 0xD) {
5425       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5426         return MCDisassembler::Fail;
5427     } else
5428       Inst.addOperand(MCOperand::createReg(0));
5429   }
5430 
5431   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5432     return MCDisassembler::Fail;
5433   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5434     return MCDisassembler::Fail;
5435   Inst.addOperand(MCOperand::createImm(index));
5436 
5437   return S;
5438 }
5439 
5440 static DecodeStatus DecodeVST2LN(MCInst &Inst, unsigned Insn, uint64_t Address,
5441                                  const MCDisassembler *Decoder) {
5442   DecodeStatus S = MCDisassembler::Success;
5443 
5444   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5445   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5446   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5447   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5448   unsigned size = fieldFromInstruction(Insn, 10, 2);
5449 
5450   unsigned align = 0;
5451   unsigned index = 0;
5452   unsigned inc = 1;
5453   switch (size) {
5454     default:
5455       return MCDisassembler::Fail;
5456     case 0:
5457       index = fieldFromInstruction(Insn, 5, 3);
5458       if (fieldFromInstruction(Insn, 4, 1))
5459         align = 2;
5460       break;
5461     case 1:
5462       index = fieldFromInstruction(Insn, 6, 2);
5463       if (fieldFromInstruction(Insn, 4, 1))
5464         align = 4;
5465       if (fieldFromInstruction(Insn, 5, 1))
5466         inc = 2;
5467       break;
5468     case 2:
5469       if (fieldFromInstruction(Insn, 5, 1))
5470         return MCDisassembler::Fail; // UNDEFINED
5471       index = fieldFromInstruction(Insn, 7, 1);
5472       if (fieldFromInstruction(Insn, 4, 1) != 0)
5473         align = 8;
5474       if (fieldFromInstruction(Insn, 6, 1))
5475         inc = 2;
5476       break;
5477   }
5478 
5479   if (Rm != 0xF) { // Writeback
5480     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5481       return MCDisassembler::Fail;
5482   }
5483   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5484     return MCDisassembler::Fail;
5485   Inst.addOperand(MCOperand::createImm(align));
5486   if (Rm != 0xF) {
5487     if (Rm != 0xD) {
5488       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5489         return MCDisassembler::Fail;
5490     } else
5491       Inst.addOperand(MCOperand::createReg(0));
5492   }
5493 
5494   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5495     return MCDisassembler::Fail;
5496   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5497     return MCDisassembler::Fail;
5498   Inst.addOperand(MCOperand::createImm(index));
5499 
5500   return S;
5501 }
5502 
5503 static DecodeStatus DecodeVLD3LN(MCInst &Inst, unsigned Insn, uint64_t Address,
5504                                  const MCDisassembler *Decoder) {
5505   DecodeStatus S = MCDisassembler::Success;
5506 
5507   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5508   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5509   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5510   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5511   unsigned size = fieldFromInstruction(Insn, 10, 2);
5512 
5513   unsigned align = 0;
5514   unsigned index = 0;
5515   unsigned inc = 1;
5516   switch (size) {
5517     default:
5518       return MCDisassembler::Fail;
5519     case 0:
5520       if (fieldFromInstruction(Insn, 4, 1))
5521         return MCDisassembler::Fail; // UNDEFINED
5522       index = fieldFromInstruction(Insn, 5, 3);
5523       break;
5524     case 1:
5525       if (fieldFromInstruction(Insn, 4, 1))
5526         return MCDisassembler::Fail; // UNDEFINED
5527       index = fieldFromInstruction(Insn, 6, 2);
5528       if (fieldFromInstruction(Insn, 5, 1))
5529         inc = 2;
5530       break;
5531     case 2:
5532       if (fieldFromInstruction(Insn, 4, 2))
5533         return MCDisassembler::Fail; // UNDEFINED
5534       index = fieldFromInstruction(Insn, 7, 1);
5535       if (fieldFromInstruction(Insn, 6, 1))
5536         inc = 2;
5537       break;
5538   }
5539 
5540   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5541     return MCDisassembler::Fail;
5542   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5543     return MCDisassembler::Fail;
5544   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5545     return MCDisassembler::Fail;
5546 
5547   if (Rm != 0xF) { // Writeback
5548     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5549     return MCDisassembler::Fail;
5550   }
5551   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5552     return MCDisassembler::Fail;
5553   Inst.addOperand(MCOperand::createImm(align));
5554   if (Rm != 0xF) {
5555     if (Rm != 0xD) {
5556       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5557     return MCDisassembler::Fail;
5558     } else
5559       Inst.addOperand(MCOperand::createReg(0));
5560   }
5561 
5562   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5563     return MCDisassembler::Fail;
5564   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5565     return MCDisassembler::Fail;
5566   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5567     return MCDisassembler::Fail;
5568   Inst.addOperand(MCOperand::createImm(index));
5569 
5570   return S;
5571 }
5572 
5573 static DecodeStatus DecodeVST3LN(MCInst &Inst, unsigned Insn, uint64_t Address,
5574                                  const MCDisassembler *Decoder) {
5575   DecodeStatus S = MCDisassembler::Success;
5576 
5577   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5578   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5579   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5580   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5581   unsigned size = fieldFromInstruction(Insn, 10, 2);
5582 
5583   unsigned align = 0;
5584   unsigned index = 0;
5585   unsigned inc = 1;
5586   switch (size) {
5587     default:
5588       return MCDisassembler::Fail;
5589     case 0:
5590       if (fieldFromInstruction(Insn, 4, 1))
5591         return MCDisassembler::Fail; // UNDEFINED
5592       index = fieldFromInstruction(Insn, 5, 3);
5593       break;
5594     case 1:
5595       if (fieldFromInstruction(Insn, 4, 1))
5596         return MCDisassembler::Fail; // UNDEFINED
5597       index = fieldFromInstruction(Insn, 6, 2);
5598       if (fieldFromInstruction(Insn, 5, 1))
5599         inc = 2;
5600       break;
5601     case 2:
5602       if (fieldFromInstruction(Insn, 4, 2))
5603         return MCDisassembler::Fail; // UNDEFINED
5604       index = fieldFromInstruction(Insn, 7, 1);
5605       if (fieldFromInstruction(Insn, 6, 1))
5606         inc = 2;
5607       break;
5608   }
5609 
5610   if (Rm != 0xF) { // Writeback
5611     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5612     return MCDisassembler::Fail;
5613   }
5614   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5615     return MCDisassembler::Fail;
5616   Inst.addOperand(MCOperand::createImm(align));
5617   if (Rm != 0xF) {
5618     if (Rm != 0xD) {
5619       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5620     return MCDisassembler::Fail;
5621     } else
5622       Inst.addOperand(MCOperand::createReg(0));
5623   }
5624 
5625   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5626     return MCDisassembler::Fail;
5627   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5628     return MCDisassembler::Fail;
5629   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5630     return MCDisassembler::Fail;
5631   Inst.addOperand(MCOperand::createImm(index));
5632 
5633   return S;
5634 }
5635 
5636 static DecodeStatus DecodeVLD4LN(MCInst &Inst, unsigned Insn, uint64_t Address,
5637                                  const MCDisassembler *Decoder) {
5638   DecodeStatus S = MCDisassembler::Success;
5639 
5640   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5641   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5642   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5643   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5644   unsigned size = fieldFromInstruction(Insn, 10, 2);
5645 
5646   unsigned align = 0;
5647   unsigned index = 0;
5648   unsigned inc = 1;
5649   switch (size) {
5650     default:
5651       return MCDisassembler::Fail;
5652     case 0:
5653       if (fieldFromInstruction(Insn, 4, 1))
5654         align = 4;
5655       index = fieldFromInstruction(Insn, 5, 3);
5656       break;
5657     case 1:
5658       if (fieldFromInstruction(Insn, 4, 1))
5659         align = 8;
5660       index = fieldFromInstruction(Insn, 6, 2);
5661       if (fieldFromInstruction(Insn, 5, 1))
5662         inc = 2;
5663       break;
5664     case 2:
5665       switch (fieldFromInstruction(Insn, 4, 2)) {
5666         case 0:
5667           align = 0; break;
5668         case 3:
5669           return MCDisassembler::Fail;
5670         default:
5671           align = 4 << fieldFromInstruction(Insn, 4, 2); break;
5672       }
5673 
5674       index = fieldFromInstruction(Insn, 7, 1);
5675       if (fieldFromInstruction(Insn, 6, 1))
5676         inc = 2;
5677       break;
5678   }
5679 
5680   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5681     return MCDisassembler::Fail;
5682   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5683     return MCDisassembler::Fail;
5684   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5685     return MCDisassembler::Fail;
5686   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5687     return MCDisassembler::Fail;
5688 
5689   if (Rm != 0xF) { // Writeback
5690     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5691       return MCDisassembler::Fail;
5692   }
5693   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5694     return MCDisassembler::Fail;
5695   Inst.addOperand(MCOperand::createImm(align));
5696   if (Rm != 0xF) {
5697     if (Rm != 0xD) {
5698       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5699         return MCDisassembler::Fail;
5700     } else
5701       Inst.addOperand(MCOperand::createReg(0));
5702   }
5703 
5704   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5705     return MCDisassembler::Fail;
5706   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5707     return MCDisassembler::Fail;
5708   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5709     return MCDisassembler::Fail;
5710   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5711     return MCDisassembler::Fail;
5712   Inst.addOperand(MCOperand::createImm(index));
5713 
5714   return S;
5715 }
5716 
5717 static DecodeStatus DecodeVST4LN(MCInst &Inst, unsigned Insn, uint64_t Address,
5718                                  const MCDisassembler *Decoder) {
5719   DecodeStatus S = MCDisassembler::Success;
5720 
5721   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5722   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5723   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5724   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5725   unsigned size = fieldFromInstruction(Insn, 10, 2);
5726 
5727   unsigned align = 0;
5728   unsigned index = 0;
5729   unsigned inc = 1;
5730   switch (size) {
5731     default:
5732       return MCDisassembler::Fail;
5733     case 0:
5734       if (fieldFromInstruction(Insn, 4, 1))
5735         align = 4;
5736       index = fieldFromInstruction(Insn, 5, 3);
5737       break;
5738     case 1:
5739       if (fieldFromInstruction(Insn, 4, 1))
5740         align = 8;
5741       index = fieldFromInstruction(Insn, 6, 2);
5742       if (fieldFromInstruction(Insn, 5, 1))
5743         inc = 2;
5744       break;
5745     case 2:
5746       switch (fieldFromInstruction(Insn, 4, 2)) {
5747         case 0:
5748           align = 0; break;
5749         case 3:
5750           return MCDisassembler::Fail;
5751         default:
5752           align = 4 << fieldFromInstruction(Insn, 4, 2); break;
5753       }
5754 
5755       index = fieldFromInstruction(Insn, 7, 1);
5756       if (fieldFromInstruction(Insn, 6, 1))
5757         inc = 2;
5758       break;
5759   }
5760 
5761   if (Rm != 0xF) { // Writeback
5762     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5763     return MCDisassembler::Fail;
5764   }
5765   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5766     return MCDisassembler::Fail;
5767   Inst.addOperand(MCOperand::createImm(align));
5768   if (Rm != 0xF) {
5769     if (Rm != 0xD) {
5770       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5771     return MCDisassembler::Fail;
5772     } else
5773       Inst.addOperand(MCOperand::createReg(0));
5774   }
5775 
5776   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5777     return MCDisassembler::Fail;
5778   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5779     return MCDisassembler::Fail;
5780   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5781     return MCDisassembler::Fail;
5782   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5783     return MCDisassembler::Fail;
5784   Inst.addOperand(MCOperand::createImm(index));
5785 
5786   return S;
5787 }
5788 
5789 static DecodeStatus DecodeVMOVSRR(MCInst &Inst, unsigned Insn, uint64_t Address,
5790                                   const MCDisassembler *Decoder) {
5791   DecodeStatus S = MCDisassembler::Success;
5792   unsigned Rt  = fieldFromInstruction(Insn, 12, 4);
5793   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
5794   unsigned Rm  = fieldFromInstruction(Insn,  5, 1);
5795   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5796   Rm |= fieldFromInstruction(Insn, 0, 4) << 1;
5797 
5798   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
5799     S = MCDisassembler::SoftFail;
5800 
5801   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
5802     return MCDisassembler::Fail;
5803   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
5804     return MCDisassembler::Fail;
5805   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
5806     return MCDisassembler::Fail;
5807   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
5808     return MCDisassembler::Fail;
5809   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5810     return MCDisassembler::Fail;
5811 
5812   return S;
5813 }
5814 
5815 static DecodeStatus DecodeVMOVRRS(MCInst &Inst, unsigned Insn, uint64_t Address,
5816                                   const MCDisassembler *Decoder) {
5817   DecodeStatus S = MCDisassembler::Success;
5818   unsigned Rt  = fieldFromInstruction(Insn, 12, 4);
5819   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
5820   unsigned Rm  = fieldFromInstruction(Insn,  5, 1);
5821   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5822   Rm |= fieldFromInstruction(Insn, 0, 4) << 1;
5823 
5824   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
5825     S = MCDisassembler::SoftFail;
5826 
5827   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
5828     return MCDisassembler::Fail;
5829   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
5830     return MCDisassembler::Fail;
5831   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
5832     return MCDisassembler::Fail;
5833   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
5834     return MCDisassembler::Fail;
5835   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5836     return MCDisassembler::Fail;
5837 
5838   return S;
5839 }
5840 
5841 static DecodeStatus DecodeIT(MCInst &Inst, unsigned Insn, uint64_t Address,
5842                              const MCDisassembler *Decoder) {
5843   DecodeStatus S = MCDisassembler::Success;
5844   unsigned pred = fieldFromInstruction(Insn, 4, 4);
5845   unsigned mask = fieldFromInstruction(Insn, 0, 4);
5846 
5847   if (pred == 0xF) {
5848     pred = 0xE;
5849     S = MCDisassembler::SoftFail;
5850   }
5851 
5852   if (mask == 0x0)
5853     return MCDisassembler::Fail;
5854 
5855   // IT masks are encoded as a sequence of replacement low-order bits
5856   // for the condition code. So if the low bit of the starting
5857   // condition code is 1, then we have to flip all the bits above the
5858   // terminating bit (which is the lowest 1 bit).
5859   if (pred & 1) {
5860     unsigned LowBit = mask & -mask;
5861     unsigned BitsAboveLowBit = 0xF & (-LowBit << 1);
5862     mask ^= BitsAboveLowBit;
5863   }
5864 
5865   Inst.addOperand(MCOperand::createImm(pred));
5866   Inst.addOperand(MCOperand::createImm(mask));
5867   return S;
5868 }
5869 
5870 static DecodeStatus DecodeT2LDRDPreInstruction(MCInst &Inst, unsigned Insn,
5871                                                uint64_t Address,
5872                                                const MCDisassembler *Decoder) {
5873   DecodeStatus S = MCDisassembler::Success;
5874 
5875   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5876   unsigned Rt2 = fieldFromInstruction(Insn, 8, 4);
5877   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5878   unsigned addr = fieldFromInstruction(Insn, 0, 8);
5879   unsigned W = fieldFromInstruction(Insn, 21, 1);
5880   unsigned U = fieldFromInstruction(Insn, 23, 1);
5881   unsigned P = fieldFromInstruction(Insn, 24, 1);
5882   bool writeback = (W == 1) | (P == 0);
5883 
5884   addr |= (U << 8) | (Rn << 9);
5885 
5886   if (writeback && (Rn == Rt || Rn == Rt2))
5887     Check(S, MCDisassembler::SoftFail);
5888   if (Rt == Rt2)
5889     Check(S, MCDisassembler::SoftFail);
5890 
5891   // Rt
5892   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
5893     return MCDisassembler::Fail;
5894   // Rt2
5895   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
5896     return MCDisassembler::Fail;
5897   // Writeback operand
5898   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
5899     return MCDisassembler::Fail;
5900   // addr
5901   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
5902     return MCDisassembler::Fail;
5903 
5904   return S;
5905 }
5906 
5907 static DecodeStatus DecodeT2STRDPreInstruction(MCInst &Inst, unsigned Insn,
5908                                                uint64_t Address,
5909                                                const MCDisassembler *Decoder) {
5910   DecodeStatus S = MCDisassembler::Success;
5911 
5912   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5913   unsigned Rt2 = fieldFromInstruction(Insn, 8, 4);
5914   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5915   unsigned addr = fieldFromInstruction(Insn, 0, 8);
5916   unsigned W = fieldFromInstruction(Insn, 21, 1);
5917   unsigned U = fieldFromInstruction(Insn, 23, 1);
5918   unsigned P = fieldFromInstruction(Insn, 24, 1);
5919   bool writeback = (W == 1) | (P == 0);
5920 
5921   addr |= (U << 8) | (Rn << 9);
5922 
5923   if (writeback && (Rn == Rt || Rn == Rt2))
5924     Check(S, MCDisassembler::SoftFail);
5925 
5926   // Writeback operand
5927   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
5928     return MCDisassembler::Fail;
5929   // Rt
5930   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
5931     return MCDisassembler::Fail;
5932   // Rt2
5933   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
5934     return MCDisassembler::Fail;
5935   // addr
5936   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
5937     return MCDisassembler::Fail;
5938 
5939   return S;
5940 }
5941 
5942 static DecodeStatus DecodeT2Adr(MCInst &Inst, uint32_t Insn, uint64_t Address,
5943                                 const MCDisassembler *Decoder) {
5944   unsigned sign1 = fieldFromInstruction(Insn, 21, 1);
5945   unsigned sign2 = fieldFromInstruction(Insn, 23, 1);
5946   if (sign1 != sign2) return MCDisassembler::Fail;
5947   const unsigned Rd = fieldFromInstruction(Insn, 8, 4);
5948   assert(Inst.getNumOperands() == 0 && "We should receive an empty Inst");
5949   DecodeStatus S = DecoderGPRRegisterClass(Inst, Rd, Address, Decoder);
5950 
5951   unsigned Val = fieldFromInstruction(Insn, 0, 8);
5952   Val |= fieldFromInstruction(Insn, 12, 3) << 8;
5953   Val |= fieldFromInstruction(Insn, 26, 1) << 11;
5954   // If sign, then it is decreasing the address.
5955   if (sign1) {
5956     // Following ARMv7 Architecture Manual, when the offset
5957     // is zero, it is decoded as a subw, not as a adr.w
5958     if (!Val) {
5959       Inst.setOpcode(ARM::t2SUBri12);
5960       Inst.addOperand(MCOperand::createReg(ARM::PC));
5961     } else
5962       Val = -Val;
5963   }
5964   Inst.addOperand(MCOperand::createImm(Val));
5965   return S;
5966 }
5967 
5968 static DecodeStatus DecodeT2ShifterImmOperand(MCInst &Inst, uint32_t Val,
5969                                               uint64_t Address,
5970                                               const MCDisassembler *Decoder) {
5971   DecodeStatus S = MCDisassembler::Success;
5972 
5973   // Shift of "asr #32" is not allowed in Thumb2 mode.
5974   if (Val == 0x20) S = MCDisassembler::Fail;
5975   Inst.addOperand(MCOperand::createImm(Val));
5976   return S;
5977 }
5978 
5979 static DecodeStatus DecodeSwap(MCInst &Inst, unsigned Insn, uint64_t Address,
5980                                const MCDisassembler *Decoder) {
5981   unsigned Rt   = fieldFromInstruction(Insn, 12, 4);
5982   unsigned Rt2  = fieldFromInstruction(Insn, 0,  4);
5983   unsigned Rn   = fieldFromInstruction(Insn, 16, 4);
5984   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5985 
5986   if (pred == 0xF)
5987     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
5988 
5989   DecodeStatus S = MCDisassembler::Success;
5990 
5991   if (Rt == Rn || Rn == Rt2)
5992     S = MCDisassembler::SoftFail;
5993 
5994   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5995     return MCDisassembler::Fail;
5996   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5997     return MCDisassembler::Fail;
5998   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
5999     return MCDisassembler::Fail;
6000   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
6001     return MCDisassembler::Fail;
6002 
6003   return S;
6004 }
6005 
6006 static DecodeStatus DecodeVCVTD(MCInst &Inst, unsigned Insn, uint64_t Address,
6007                                 const MCDisassembler *Decoder) {
6008   const FeatureBitset &featureBits =
6009       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
6010   bool hasFullFP16 = featureBits[ARM::FeatureFullFP16];
6011 
6012   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
6013   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
6014   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
6015   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
6016   unsigned imm = fieldFromInstruction(Insn, 16, 6);
6017   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
6018   unsigned op = fieldFromInstruction(Insn, 5, 1);
6019 
6020   DecodeStatus S = MCDisassembler::Success;
6021 
6022   // If the top 3 bits of imm are clear, this is a VMOV (immediate)
6023   if (!(imm & 0x38)) {
6024     if (cmode == 0xF) {
6025       if (op == 1) return MCDisassembler::Fail;
6026       Inst.setOpcode(ARM::VMOVv2f32);
6027     }
6028     if (hasFullFP16) {
6029       if (cmode == 0xE) {
6030         if (op == 1) {
6031           Inst.setOpcode(ARM::VMOVv1i64);
6032         } else {
6033           Inst.setOpcode(ARM::VMOVv8i8);
6034         }
6035       }
6036       if (cmode == 0xD) {
6037         if (op == 1) {
6038           Inst.setOpcode(ARM::VMVNv2i32);
6039         } else {
6040           Inst.setOpcode(ARM::VMOVv2i32);
6041         }
6042       }
6043       if (cmode == 0xC) {
6044         if (op == 1) {
6045           Inst.setOpcode(ARM::VMVNv2i32);
6046         } else {
6047           Inst.setOpcode(ARM::VMOVv2i32);
6048         }
6049       }
6050     }
6051     return DecodeVMOVModImmInstruction(Inst, Insn, Address, Decoder);
6052   }
6053 
6054   if (!(imm & 0x20)) return MCDisassembler::Fail;
6055 
6056   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
6057     return MCDisassembler::Fail;
6058   if (!Check(S, DecodeDPRRegisterClass(Inst, Vm, Address, Decoder)))
6059     return MCDisassembler::Fail;
6060   Inst.addOperand(MCOperand::createImm(64 - imm));
6061 
6062   return S;
6063 }
6064 
6065 static DecodeStatus DecodeVCVTQ(MCInst &Inst, unsigned Insn, uint64_t Address,
6066                                 const MCDisassembler *Decoder) {
6067   const FeatureBitset &featureBits =
6068       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
6069   bool hasFullFP16 = featureBits[ARM::FeatureFullFP16];
6070 
6071   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
6072   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
6073   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
6074   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
6075   unsigned imm = fieldFromInstruction(Insn, 16, 6);
6076   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
6077   unsigned op = fieldFromInstruction(Insn, 5, 1);
6078 
6079   DecodeStatus S = MCDisassembler::Success;
6080 
6081   // If the top 3 bits of imm are clear, this is a VMOV (immediate)
6082   if (!(imm & 0x38)) {
6083     if (cmode == 0xF) {
6084       if (op == 1) return MCDisassembler::Fail;
6085       Inst.setOpcode(ARM::VMOVv4f32);
6086     }
6087     if (hasFullFP16) {
6088       if (cmode == 0xE) {
6089         if (op == 1) {
6090           Inst.setOpcode(ARM::VMOVv2i64);
6091         } else {
6092           Inst.setOpcode(ARM::VMOVv16i8);
6093         }
6094       }
6095       if (cmode == 0xD) {
6096         if (op == 1) {
6097           Inst.setOpcode(ARM::VMVNv4i32);
6098         } else {
6099           Inst.setOpcode(ARM::VMOVv4i32);
6100         }
6101       }
6102       if (cmode == 0xC) {
6103         if (op == 1) {
6104           Inst.setOpcode(ARM::VMVNv4i32);
6105         } else {
6106           Inst.setOpcode(ARM::VMOVv4i32);
6107         }
6108       }
6109     }
6110     return DecodeVMOVModImmInstruction(Inst, Insn, Address, Decoder);
6111   }
6112 
6113   if (!(imm & 0x20)) return MCDisassembler::Fail;
6114 
6115   if (!Check(S, DecodeQPRRegisterClass(Inst, Vd, Address, Decoder)))
6116     return MCDisassembler::Fail;
6117   if (!Check(S, DecodeQPRRegisterClass(Inst, Vm, Address, Decoder)))
6118     return MCDisassembler::Fail;
6119   Inst.addOperand(MCOperand::createImm(64 - imm));
6120 
6121   return S;
6122 }
6123 
6124 static DecodeStatus
6125 DecodeNEONComplexLane64Instruction(MCInst &Inst, unsigned Insn,
6126                                    uint64_t Address,
6127                                    const MCDisassembler *Decoder) {
6128   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
6129   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
6130   unsigned Vn = (fieldFromInstruction(Insn, 16, 4) << 0);
6131   Vn |= (fieldFromInstruction(Insn, 7, 1) << 4);
6132   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
6133   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
6134   unsigned q = (fieldFromInstruction(Insn, 6, 1) << 0);
6135   unsigned rotate = (fieldFromInstruction(Insn, 20, 2) << 0);
6136 
6137   DecodeStatus S = MCDisassembler::Success;
6138 
6139   auto DestRegDecoder = q ? DecodeQPRRegisterClass : DecodeDPRRegisterClass;
6140 
6141   if (!Check(S, DestRegDecoder(Inst, Vd, Address, Decoder)))
6142     return MCDisassembler::Fail;
6143   if (!Check(S, DestRegDecoder(Inst, Vd, Address, Decoder)))
6144     return MCDisassembler::Fail;
6145   if (!Check(S, DestRegDecoder(Inst, Vn, Address, Decoder)))
6146     return MCDisassembler::Fail;
6147   if (!Check(S, DecodeDPRRegisterClass(Inst, Vm, Address, Decoder)))
6148     return MCDisassembler::Fail;
6149   // The lane index does not have any bits in the encoding, because it can only
6150   // be 0.
6151   Inst.addOperand(MCOperand::createImm(0));
6152   Inst.addOperand(MCOperand::createImm(rotate));
6153 
6154   return S;
6155 }
6156 
6157 static DecodeStatus DecodeLDR(MCInst &Inst, unsigned Val, uint64_t Address,
6158                               const MCDisassembler *Decoder) {
6159   DecodeStatus S = MCDisassembler::Success;
6160 
6161   unsigned Rn = fieldFromInstruction(Val, 16, 4);
6162   unsigned Rt = fieldFromInstruction(Val, 12, 4);
6163   unsigned Rm = fieldFromInstruction(Val, 0, 4);
6164   Rm |= (fieldFromInstruction(Val, 23, 1) << 4);
6165   unsigned Cond = fieldFromInstruction(Val, 28, 4);
6166 
6167   if (fieldFromInstruction(Val, 8, 4) != 0 || Rn == Rt)
6168     S = MCDisassembler::SoftFail;
6169 
6170   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
6171     return MCDisassembler::Fail;
6172   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
6173     return MCDisassembler::Fail;
6174   if (!Check(S, DecodeAddrMode7Operand(Inst, Rn, Address, Decoder)))
6175     return MCDisassembler::Fail;
6176   if (!Check(S, DecodePostIdxReg(Inst, Rm, Address, Decoder)))
6177     return MCDisassembler::Fail;
6178   if (!Check(S, DecodePredicateOperand(Inst, Cond, Address, Decoder)))
6179     return MCDisassembler::Fail;
6180 
6181   return S;
6182 }
6183 
6184 static DecodeStatus DecoderForMRRC2AndMCRR2(MCInst &Inst, unsigned Val,
6185                                             uint64_t Address,
6186                                             const MCDisassembler *Decoder) {
6187   DecodeStatus S = MCDisassembler::Success;
6188 
6189   unsigned CRm = fieldFromInstruction(Val, 0, 4);
6190   unsigned opc1 = fieldFromInstruction(Val, 4, 4);
6191   unsigned cop = fieldFromInstruction(Val, 8, 4);
6192   unsigned Rt = fieldFromInstruction(Val, 12, 4);
6193   unsigned Rt2 = fieldFromInstruction(Val, 16, 4);
6194 
6195   if ((cop & ~0x1) == 0xa)
6196     return MCDisassembler::Fail;
6197 
6198   if (Rt == Rt2)
6199     S = MCDisassembler::SoftFail;
6200 
6201   // We have to check if the instruction is MRRC2
6202   // or MCRR2 when constructing the operands for
6203   // Inst. Reason is because MRRC2 stores to two
6204   // registers so it's tablegen desc has has two
6205   // outputs whereas MCRR doesn't store to any
6206   // registers so all of it's operands are listed
6207   // as inputs, therefore the operand order for
6208   // MRRC2 needs to be [Rt, Rt2, cop, opc1, CRm]
6209   // and MCRR2 operand order is [cop, opc1, Rt, Rt2, CRm]
6210 
6211   if (Inst.getOpcode() == ARM::MRRC2) {
6212     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
6213       return MCDisassembler::Fail;
6214     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
6215       return MCDisassembler::Fail;
6216   }
6217   Inst.addOperand(MCOperand::createImm(cop));
6218   Inst.addOperand(MCOperand::createImm(opc1));
6219   if (Inst.getOpcode() == ARM::MCRR2) {
6220     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
6221       return MCDisassembler::Fail;
6222     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
6223       return MCDisassembler::Fail;
6224   }
6225   Inst.addOperand(MCOperand::createImm(CRm));
6226 
6227   return S;
6228 }
6229 
6230 static DecodeStatus DecodeForVMRSandVMSR(MCInst &Inst, unsigned Val,
6231                                          uint64_t Address,
6232                                          const MCDisassembler *Decoder) {
6233   const FeatureBitset &featureBits =
6234       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
6235   DecodeStatus S = MCDisassembler::Success;
6236 
6237   // Add explicit operand for the destination sysreg, for cases where
6238   // we have to model it for code generation purposes.
6239   switch (Inst.getOpcode()) {
6240   case ARM::VMSR_FPSCR_NZCVQC:
6241     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
6242     break;
6243   case ARM::VMSR_P0:
6244     Inst.addOperand(MCOperand::createReg(ARM::VPR));
6245     break;
6246   }
6247 
6248   if (Inst.getOpcode() != ARM::FMSTAT) {
6249     unsigned Rt = fieldFromInstruction(Val, 12, 4);
6250 
6251     if (featureBits[ARM::ModeThumb] && !featureBits[ARM::HasV8Ops]) {
6252       if (Rt == 13 || Rt == 15)
6253         S = MCDisassembler::SoftFail;
6254       Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder));
6255     } else
6256       Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder));
6257   }
6258 
6259   // Add explicit operand for the source sysreg, similarly to above.
6260   switch (Inst.getOpcode()) {
6261   case ARM::VMRS_FPSCR_NZCVQC:
6262     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
6263     break;
6264   case ARM::VMRS_P0:
6265     Inst.addOperand(MCOperand::createReg(ARM::VPR));
6266     break;
6267   }
6268 
6269   if (featureBits[ARM::ModeThumb]) {
6270     Inst.addOperand(MCOperand::createImm(ARMCC::AL));
6271     Inst.addOperand(MCOperand::createReg(0));
6272   } else {
6273     unsigned pred = fieldFromInstruction(Val, 28, 4);
6274     if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
6275       return MCDisassembler::Fail;
6276   }
6277 
6278   return S;
6279 }
6280 
6281 template <bool isSigned, bool isNeg, bool zeroPermitted, int size>
6282 static DecodeStatus DecodeBFLabelOperand(MCInst &Inst, unsigned Val,
6283                                          uint64_t Address,
6284                                          const MCDisassembler *Decoder) {
6285   DecodeStatus S = MCDisassembler::Success;
6286   if (Val == 0 && !zeroPermitted)
6287     S = MCDisassembler::Fail;
6288 
6289   uint64_t DecVal;
6290   if (isSigned)
6291     DecVal = SignExtend32<size + 1>(Val << 1);
6292   else
6293     DecVal = (Val << 1);
6294 
6295   if (!tryAddingSymbolicOperand(Address, Address + DecVal + 4, true, 4, Inst,
6296                                 Decoder))
6297     Inst.addOperand(MCOperand::createImm(isNeg ? -DecVal : DecVal));
6298   return S;
6299 }
6300 
6301 static DecodeStatus DecodeBFAfterTargetOperand(MCInst &Inst, unsigned Val,
6302                                                uint64_t Address,
6303                                                const MCDisassembler *Decoder) {
6304 
6305   uint64_t LocImm = Inst.getOperand(0).getImm();
6306   Val = LocImm + (2 << Val);
6307   if (!tryAddingSymbolicOperand(Address, Address + Val + 4, true, 4, Inst,
6308                                 Decoder))
6309     Inst.addOperand(MCOperand::createImm(Val));
6310   return MCDisassembler::Success;
6311 }
6312 
6313 static DecodeStatus DecodePredNoALOperand(MCInst &Inst, unsigned Val,
6314                                           uint64_t Address,
6315                                           const MCDisassembler *Decoder) {
6316   if (Val >= ARMCC::AL)  // also exclude the non-condition NV
6317     return MCDisassembler::Fail;
6318   Inst.addOperand(MCOperand::createImm(Val));
6319   return MCDisassembler::Success;
6320 }
6321 
6322 static DecodeStatus DecodeLOLoop(MCInst &Inst, unsigned Insn, uint64_t Address,
6323                                  const MCDisassembler *Decoder) {
6324   DecodeStatus S = MCDisassembler::Success;
6325 
6326   if (Inst.getOpcode() == ARM::MVE_LCTP)
6327     return S;
6328 
6329   unsigned Imm = fieldFromInstruction(Insn, 11, 1) |
6330                  fieldFromInstruction(Insn, 1, 10) << 1;
6331   switch (Inst.getOpcode()) {
6332   case ARM::t2LEUpdate:
6333   case ARM::MVE_LETP:
6334     Inst.addOperand(MCOperand::createReg(ARM::LR));
6335     Inst.addOperand(MCOperand::createReg(ARM::LR));
6336     [[fallthrough]];
6337   case ARM::t2LE:
6338     if (!Check(S, DecodeBFLabelOperand<false, true, true, 11>(
6339                    Inst, Imm, Address, Decoder)))
6340       return MCDisassembler::Fail;
6341     break;
6342   case ARM::t2WLS:
6343   case ARM::MVE_WLSTP_8:
6344   case ARM::MVE_WLSTP_16:
6345   case ARM::MVE_WLSTP_32:
6346   case ARM::MVE_WLSTP_64:
6347     Inst.addOperand(MCOperand::createReg(ARM::LR));
6348     if (!Check(S,
6349                DecoderGPRRegisterClass(Inst, fieldFromInstruction(Insn, 16, 4),
6350                                        Address, Decoder)) ||
6351         !Check(S, DecodeBFLabelOperand<false, false, true, 11>(
6352                    Inst, Imm, Address, Decoder)))
6353       return MCDisassembler::Fail;
6354     break;
6355   case ARM::t2DLS:
6356   case ARM::MVE_DLSTP_8:
6357   case ARM::MVE_DLSTP_16:
6358   case ARM::MVE_DLSTP_32:
6359   case ARM::MVE_DLSTP_64:
6360     unsigned Rn = fieldFromInstruction(Insn, 16, 4);
6361     if (Rn == 0xF) {
6362       // Enforce all the rest of the instruction bits in LCTP, which
6363       // won't have been reliably checked based on LCTP's own tablegen
6364       // record, because we came to this decode by a roundabout route.
6365       uint32_t CanonicalLCTP = 0xF00FE001, SBZMask = 0x00300FFE;
6366       if ((Insn & ~SBZMask) != CanonicalLCTP)
6367         return MCDisassembler::Fail;   // a mandatory bit is wrong: hard fail
6368       if (Insn != CanonicalLCTP)
6369         Check(S, MCDisassembler::SoftFail); // an SBZ bit is wrong: soft fail
6370 
6371       Inst.setOpcode(ARM::MVE_LCTP);
6372     } else {
6373       Inst.addOperand(MCOperand::createReg(ARM::LR));
6374       if (!Check(S, DecoderGPRRegisterClass(Inst,
6375                                             fieldFromInstruction(Insn, 16, 4),
6376                                             Address, Decoder)))
6377         return MCDisassembler::Fail;
6378     }
6379     break;
6380   }
6381   return S;
6382 }
6383 
6384 static DecodeStatus DecodeLongShiftOperand(MCInst &Inst, unsigned Val,
6385                                            uint64_t Address,
6386                                            const MCDisassembler *Decoder) {
6387   DecodeStatus S = MCDisassembler::Success;
6388 
6389   if (Val == 0)
6390     Val = 32;
6391 
6392   Inst.addOperand(MCOperand::createImm(Val));
6393 
6394   return S;
6395 }
6396 
6397 static DecodeStatus DecodetGPROddRegisterClass(MCInst &Inst, unsigned RegNo,
6398                                                uint64_t Address,
6399                                                const MCDisassembler *Decoder) {
6400   if ((RegNo) + 1 > 11)
6401     return MCDisassembler::Fail;
6402 
6403   unsigned Register = GPRDecoderTable[(RegNo) + 1];
6404   Inst.addOperand(MCOperand::createReg(Register));
6405   return MCDisassembler::Success;
6406 }
6407 
6408 static DecodeStatus DecodetGPREvenRegisterClass(MCInst &Inst, unsigned RegNo,
6409                                                 uint64_t Address,
6410                                                 const MCDisassembler *Decoder) {
6411   if ((RegNo) > 14)
6412     return MCDisassembler::Fail;
6413 
6414   unsigned Register = GPRDecoderTable[(RegNo)];
6415   Inst.addOperand(MCOperand::createReg(Register));
6416   return MCDisassembler::Success;
6417 }
6418 
6419 static DecodeStatus
6420 DecodeGPRwithAPSR_NZCVnospRegisterClass(MCInst &Inst, unsigned RegNo,
6421                                         uint64_t Address,
6422                                         const MCDisassembler *Decoder) {
6423   if (RegNo == 15) {
6424     Inst.addOperand(MCOperand::createReg(ARM::APSR_NZCV));
6425     return MCDisassembler::Success;
6426   }
6427 
6428   unsigned Register = GPRDecoderTable[RegNo];
6429   Inst.addOperand(MCOperand::createReg(Register));
6430 
6431   if (RegNo == 13)
6432     return MCDisassembler::SoftFail;
6433 
6434   return MCDisassembler::Success;
6435 }
6436 
6437 static DecodeStatus DecodeVSCCLRM(MCInst &Inst, unsigned Insn, uint64_t Address,
6438                                   const MCDisassembler *Decoder) {
6439   DecodeStatus S = MCDisassembler::Success;
6440 
6441   Inst.addOperand(MCOperand::createImm(ARMCC::AL));
6442   Inst.addOperand(MCOperand::createReg(0));
6443   if (Inst.getOpcode() == ARM::VSCCLRMD) {
6444     unsigned reglist = (fieldFromInstruction(Insn, 1, 7) << 1) |
6445                        (fieldFromInstruction(Insn, 12, 4) << 8) |
6446                        (fieldFromInstruction(Insn, 22, 1) << 12);
6447     if (!Check(S, DecodeDPRRegListOperand(Inst, reglist, Address, Decoder))) {
6448       return MCDisassembler::Fail;
6449     }
6450   } else {
6451     unsigned reglist = fieldFromInstruction(Insn, 0, 8) |
6452                        (fieldFromInstruction(Insn, 22, 1) << 8) |
6453                        (fieldFromInstruction(Insn, 12, 4) << 9);
6454     if (!Check(S, DecodeSPRRegListOperand(Inst, reglist, Address, Decoder))) {
6455       return MCDisassembler::Fail;
6456     }
6457   }
6458   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6459 
6460   return S;
6461 }
6462 
6463 static DecodeStatus DecodeMQPRRegisterClass(MCInst &Inst, unsigned RegNo,
6464                                             uint64_t Address,
6465                                             const MCDisassembler *Decoder) {
6466   if (RegNo > 7)
6467     return MCDisassembler::Fail;
6468 
6469   unsigned Register = QPRDecoderTable[RegNo];
6470   Inst.addOperand(MCOperand::createReg(Register));
6471   return MCDisassembler::Success;
6472 }
6473 
6474 static const uint16_t QQPRDecoderTable[] = {
6475      ARM::Q0_Q1,  ARM::Q1_Q2,  ARM::Q2_Q3,  ARM::Q3_Q4,
6476      ARM::Q4_Q5,  ARM::Q5_Q6,  ARM::Q6_Q7
6477 };
6478 
6479 static DecodeStatus DecodeMQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
6480                                              uint64_t Address,
6481                                              const MCDisassembler *Decoder) {
6482   if (RegNo > 6)
6483     return MCDisassembler::Fail;
6484 
6485   unsigned Register = QQPRDecoderTable[RegNo];
6486   Inst.addOperand(MCOperand::createReg(Register));
6487   return MCDisassembler::Success;
6488 }
6489 
6490 static const uint16_t QQQQPRDecoderTable[] = {
6491      ARM::Q0_Q1_Q2_Q3,  ARM::Q1_Q2_Q3_Q4,  ARM::Q2_Q3_Q4_Q5,
6492      ARM::Q3_Q4_Q5_Q6,  ARM::Q4_Q5_Q6_Q7
6493 };
6494 
6495 static DecodeStatus DecodeMQQQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
6496                                                uint64_t Address,
6497                                                const MCDisassembler *Decoder) {
6498   if (RegNo > 4)
6499     return MCDisassembler::Fail;
6500 
6501   unsigned Register = QQQQPRDecoderTable[RegNo];
6502   Inst.addOperand(MCOperand::createReg(Register));
6503   return MCDisassembler::Success;
6504 }
6505 
6506 static DecodeStatus DecodeVPTMaskOperand(MCInst &Inst, unsigned Val,
6507                                          uint64_t Address,
6508                                          const MCDisassembler *Decoder) {
6509   DecodeStatus S = MCDisassembler::Success;
6510 
6511   // Parse VPT mask and encode it in the MCInst as an immediate with the same
6512   // format as the it_mask.  That is, from the second 'e|t' encode 'e' as 1 and
6513   // 't' as 0 and finish with a 1.
6514   unsigned Imm = 0;
6515   // We always start with a 't'.
6516   unsigned CurBit = 0;
6517   for (int i = 3; i >= 0; --i) {
6518     // If the bit we are looking at is not the same as last one, invert the
6519     // CurBit, if it is the same leave it as is.
6520     CurBit ^= (Val >> i) & 1U;
6521 
6522     // Encode the CurBit at the right place in the immediate.
6523     Imm |= (CurBit << i);
6524 
6525     // If we are done, finish the encoding with a 1.
6526     if ((Val & ~(~0U << i)) == 0) {
6527       Imm |= 1U << i;
6528       break;
6529     }
6530   }
6531 
6532   Inst.addOperand(MCOperand::createImm(Imm));
6533 
6534   return S;
6535 }
6536 
6537 static DecodeStatus DecodeVpredROperand(MCInst &Inst, unsigned RegNo,
6538                                         uint64_t Address,
6539                                         const MCDisassembler *Decoder) {
6540   // The vpred_r operand type includes an MQPR register field derived
6541   // from the encoding. But we don't actually want to add an operand
6542   // to the MCInst at this stage, because AddThumbPredicate will do it
6543   // later, and will infer the register number from the TIED_TO
6544   // constraint. So this is a deliberately empty decoder method that
6545   // will inhibit the auto-generated disassembly code from adding an
6546   // operand at all.
6547   return MCDisassembler::Success;
6548 }
6549 
6550 [[maybe_unused]] static DecodeStatus
6551 DecodeVpredNOperand(MCInst &Inst, unsigned RegNo, uint64_t Address,
6552                     const MCDisassembler *Decoder) {
6553   // Similar to above, we want to ensure that no operands are added for the
6554   // vpred operands. (This is marked "maybe_unused" for the moment; because
6555   // DecoderEmitter currently (wrongly) omits operands with no instruction bits,
6556   // the decoder doesn't actually call it yet. That will be addressed in a
6557   // future change.)
6558   return MCDisassembler::Success;
6559 }
6560 
6561 static DecodeStatus
6562 DecodeRestrictedIPredicateOperand(MCInst &Inst, unsigned Val, uint64_t Address,
6563                                   const MCDisassembler *Decoder) {
6564   Inst.addOperand(MCOperand::createImm((Val & 0x1) == 0 ? ARMCC::EQ : ARMCC::NE));
6565   return MCDisassembler::Success;
6566 }
6567 
6568 static DecodeStatus
6569 DecodeRestrictedSPredicateOperand(MCInst &Inst, unsigned Val, uint64_t Address,
6570                                   const MCDisassembler *Decoder) {
6571   unsigned Code;
6572   switch (Val & 0x3) {
6573   case 0:
6574     Code = ARMCC::GE;
6575     break;
6576   case 1:
6577     Code = ARMCC::LT;
6578     break;
6579   case 2:
6580     Code = ARMCC::GT;
6581     break;
6582   case 3:
6583     Code = ARMCC::LE;
6584     break;
6585   }
6586   Inst.addOperand(MCOperand::createImm(Code));
6587   return MCDisassembler::Success;
6588 }
6589 
6590 static DecodeStatus
6591 DecodeRestrictedUPredicateOperand(MCInst &Inst, unsigned Val, uint64_t Address,
6592                                   const MCDisassembler *Decoder) {
6593   Inst.addOperand(MCOperand::createImm((Val & 0x1) == 0 ? ARMCC::HS : ARMCC::HI));
6594   return MCDisassembler::Success;
6595 }
6596 
6597 static DecodeStatus
6598 DecodeRestrictedFPPredicateOperand(MCInst &Inst, unsigned Val, uint64_t Address,
6599                                    const MCDisassembler *Decoder) {
6600   unsigned Code;
6601   switch (Val) {
6602   default:
6603     return MCDisassembler::Fail;
6604   case 0:
6605     Code = ARMCC::EQ;
6606     break;
6607   case 1:
6608     Code = ARMCC::NE;
6609     break;
6610   case 4:
6611     Code = ARMCC::GE;
6612     break;
6613   case 5:
6614     Code = ARMCC::LT;
6615     break;
6616   case 6:
6617     Code = ARMCC::GT;
6618     break;
6619   case 7:
6620     Code = ARMCC::LE;
6621     break;
6622   }
6623 
6624   Inst.addOperand(MCOperand::createImm(Code));
6625   return MCDisassembler::Success;
6626 }
6627 
6628 static DecodeStatus DecodeVCVTImmOperand(MCInst &Inst, unsigned Val,
6629                                          uint64_t Address,
6630                                          const MCDisassembler *Decoder) {
6631   DecodeStatus S = MCDisassembler::Success;
6632 
6633   unsigned DecodedVal = 64 - Val;
6634 
6635   switch (Inst.getOpcode()) {
6636   case ARM::MVE_VCVTf16s16_fix:
6637   case ARM::MVE_VCVTs16f16_fix:
6638   case ARM::MVE_VCVTf16u16_fix:
6639   case ARM::MVE_VCVTu16f16_fix:
6640     if (DecodedVal > 16)
6641       return MCDisassembler::Fail;
6642     break;
6643   case ARM::MVE_VCVTf32s32_fix:
6644   case ARM::MVE_VCVTs32f32_fix:
6645   case ARM::MVE_VCVTf32u32_fix:
6646   case ARM::MVE_VCVTu32f32_fix:
6647     if (DecodedVal > 32)
6648       return MCDisassembler::Fail;
6649     break;
6650   }
6651 
6652   Inst.addOperand(MCOperand::createImm(64 - Val));
6653 
6654   return S;
6655 }
6656 
6657 static unsigned FixedRegForVSTRVLDR_SYSREG(unsigned Opcode) {
6658   switch (Opcode) {
6659   case ARM::VSTR_P0_off:
6660   case ARM::VSTR_P0_pre:
6661   case ARM::VSTR_P0_post:
6662   case ARM::VLDR_P0_off:
6663   case ARM::VLDR_P0_pre:
6664   case ARM::VLDR_P0_post:
6665     return ARM::P0;
6666   default:
6667     return 0;
6668   }
6669 }
6670 
6671 template <bool Writeback>
6672 static DecodeStatus DecodeVSTRVLDR_SYSREG(MCInst &Inst, unsigned Val,
6673                                           uint64_t Address,
6674                                           const MCDisassembler *Decoder) {
6675   switch (Inst.getOpcode()) {
6676   case ARM::VSTR_FPSCR_pre:
6677   case ARM::VSTR_FPSCR_NZCVQC_pre:
6678   case ARM::VLDR_FPSCR_pre:
6679   case ARM::VLDR_FPSCR_NZCVQC_pre:
6680   case ARM::VSTR_FPSCR_off:
6681   case ARM::VSTR_FPSCR_NZCVQC_off:
6682   case ARM::VLDR_FPSCR_off:
6683   case ARM::VLDR_FPSCR_NZCVQC_off:
6684   case ARM::VSTR_FPSCR_post:
6685   case ARM::VSTR_FPSCR_NZCVQC_post:
6686   case ARM::VLDR_FPSCR_post:
6687   case ARM::VLDR_FPSCR_NZCVQC_post:
6688     const FeatureBitset &featureBits =
6689         ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
6690 
6691     if (!featureBits[ARM::HasMVEIntegerOps] && !featureBits[ARM::FeatureVFP2])
6692       return MCDisassembler::Fail;
6693   }
6694 
6695   DecodeStatus S = MCDisassembler::Success;
6696   if (unsigned Sysreg = FixedRegForVSTRVLDR_SYSREG(Inst.getOpcode()))
6697     Inst.addOperand(MCOperand::createReg(Sysreg));
6698   unsigned Rn = fieldFromInstruction(Val, 16, 4);
6699   unsigned addr = fieldFromInstruction(Val, 0, 7) |
6700                   (fieldFromInstruction(Val, 23, 1) << 7) | (Rn << 8);
6701 
6702   if (Writeback) {
6703     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
6704       return MCDisassembler::Fail;
6705   }
6706   if (!Check(S, DecodeT2AddrModeImm7s4(Inst, addr, Address, Decoder)))
6707     return MCDisassembler::Fail;
6708 
6709   Inst.addOperand(MCOperand::createImm(ARMCC::AL));
6710   Inst.addOperand(MCOperand::createReg(0));
6711 
6712   return S;
6713 }
6714 
6715 static inline DecodeStatus
6716 DecodeMVE_MEM_pre(MCInst &Inst, unsigned Val, uint64_t Address,
6717                   const MCDisassembler *Decoder, unsigned Rn,
6718                   OperandDecoder RnDecoder, OperandDecoder AddrDecoder) {
6719   DecodeStatus S = MCDisassembler::Success;
6720 
6721   unsigned Qd = fieldFromInstruction(Val, 13, 3);
6722   unsigned addr = fieldFromInstruction(Val, 0, 7) |
6723                   (fieldFromInstruction(Val, 23, 1) << 7) | (Rn << 8);
6724 
6725   if (!Check(S, RnDecoder(Inst, Rn, Address, Decoder)))
6726     return MCDisassembler::Fail;
6727   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6728     return MCDisassembler::Fail;
6729   if (!Check(S, AddrDecoder(Inst, addr, Address, Decoder)))
6730     return MCDisassembler::Fail;
6731 
6732   return S;
6733 }
6734 
6735 template <int shift>
6736 static DecodeStatus DecodeMVE_MEM_1_pre(MCInst &Inst, unsigned Val,
6737                                         uint64_t Address,
6738                                         const MCDisassembler *Decoder) {
6739   return DecodeMVE_MEM_pre(Inst, Val, Address, Decoder,
6740                            fieldFromInstruction(Val, 16, 3),
6741                            DecodetGPRRegisterClass,
6742                            DecodeTAddrModeImm7<shift>);
6743 }
6744 
6745 template <int shift>
6746 static DecodeStatus DecodeMVE_MEM_2_pre(MCInst &Inst, unsigned Val,
6747                                         uint64_t Address,
6748                                         const MCDisassembler *Decoder) {
6749   return DecodeMVE_MEM_pre(Inst, Val, Address, Decoder,
6750                            fieldFromInstruction(Val, 16, 4),
6751                            DecoderGPRRegisterClass,
6752                            DecodeT2AddrModeImm7<shift,1>);
6753 }
6754 
6755 template <int shift>
6756 static DecodeStatus DecodeMVE_MEM_3_pre(MCInst &Inst, unsigned Val,
6757                                         uint64_t Address,
6758                                         const MCDisassembler *Decoder) {
6759   return DecodeMVE_MEM_pre(Inst, Val, Address, Decoder,
6760                            fieldFromInstruction(Val, 17, 3),
6761                            DecodeMQPRRegisterClass,
6762                            DecodeMveAddrModeQ<shift>);
6763 }
6764 
6765 template <unsigned MinLog, unsigned MaxLog>
6766 static DecodeStatus DecodePowerTwoOperand(MCInst &Inst, unsigned Val,
6767                                           uint64_t Address,
6768                                           const MCDisassembler *Decoder) {
6769   DecodeStatus S = MCDisassembler::Success;
6770 
6771   if (Val < MinLog || Val > MaxLog)
6772     return MCDisassembler::Fail;
6773 
6774   Inst.addOperand(MCOperand::createImm(1LL << Val));
6775   return S;
6776 }
6777 
6778 template <unsigned start>
6779 static DecodeStatus
6780 DecodeMVEPairVectorIndexOperand(MCInst &Inst, unsigned Val, uint64_t Address,
6781                                 const MCDisassembler *Decoder) {
6782   DecodeStatus S = MCDisassembler::Success;
6783 
6784   Inst.addOperand(MCOperand::createImm(start + Val));
6785 
6786   return S;
6787 }
6788 
6789 static DecodeStatus DecodeMVEVMOVQtoDReg(MCInst &Inst, unsigned Insn,
6790                                          uint64_t Address,
6791                                          const MCDisassembler *Decoder) {
6792   DecodeStatus S = MCDisassembler::Success;
6793   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
6794   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
6795   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
6796                  fieldFromInstruction(Insn, 13, 3));
6797   unsigned index = fieldFromInstruction(Insn, 4, 1);
6798 
6799   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
6800     return MCDisassembler::Fail;
6801   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2, Address, Decoder)))
6802     return MCDisassembler::Fail;
6803   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6804     return MCDisassembler::Fail;
6805   if (!Check(S, DecodeMVEPairVectorIndexOperand<2>(Inst, index, Address, Decoder)))
6806     return MCDisassembler::Fail;
6807   if (!Check(S, DecodeMVEPairVectorIndexOperand<0>(Inst, index, Address, Decoder)))
6808     return MCDisassembler::Fail;
6809 
6810   return S;
6811 }
6812 
6813 static DecodeStatus DecodeMVEVMOVDRegtoQ(MCInst &Inst, unsigned Insn,
6814                                          uint64_t Address,
6815                                          const MCDisassembler *Decoder) {
6816   DecodeStatus S = MCDisassembler::Success;
6817   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
6818   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
6819   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
6820                  fieldFromInstruction(Insn, 13, 3));
6821   unsigned index = fieldFromInstruction(Insn, 4, 1);
6822 
6823   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6824     return MCDisassembler::Fail;
6825   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6826     return MCDisassembler::Fail;
6827   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
6828     return MCDisassembler::Fail;
6829   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2, Address, Decoder)))
6830     return MCDisassembler::Fail;
6831   if (!Check(S, DecodeMVEPairVectorIndexOperand<2>(Inst, index, Address, Decoder)))
6832     return MCDisassembler::Fail;
6833   if (!Check(S, DecodeMVEPairVectorIndexOperand<0>(Inst, index, Address, Decoder)))
6834     return MCDisassembler::Fail;
6835 
6836   return S;
6837 }
6838 
6839 static DecodeStatus
6840 DecodeMVEOverlappingLongShift(MCInst &Inst, unsigned Insn, uint64_t Address,
6841                               const MCDisassembler *Decoder) {
6842   DecodeStatus S = MCDisassembler::Success;
6843 
6844   unsigned RdaLo = fieldFromInstruction(Insn, 17, 3) << 1;
6845   unsigned RdaHi = fieldFromInstruction(Insn, 9, 3) << 1;
6846   unsigned Rm = fieldFromInstruction(Insn, 12, 4);
6847 
6848   if (RdaHi == 14) {
6849     // This value of RdaHi (really indicating pc, because RdaHi has to
6850     // be an odd-numbered register, so the low bit will be set by the
6851     // decode function below) indicates that we must decode as SQRSHR
6852     // or UQRSHL, which both have a single Rda register field with all
6853     // four bits.
6854     unsigned Rda = fieldFromInstruction(Insn, 16, 4);
6855 
6856     switch (Inst.getOpcode()) {
6857       case ARM::MVE_ASRLr:
6858       case ARM::MVE_SQRSHRL:
6859         Inst.setOpcode(ARM::MVE_SQRSHR);
6860         break;
6861       case ARM::MVE_LSLLr:
6862       case ARM::MVE_UQRSHLL:
6863         Inst.setOpcode(ARM::MVE_UQRSHL);
6864         break;
6865       default:
6866         llvm_unreachable("Unexpected starting opcode!");
6867     }
6868 
6869     // Rda as output parameter
6870     if (!Check(S, DecoderGPRRegisterClass(Inst, Rda, Address, Decoder)))
6871       return MCDisassembler::Fail;
6872 
6873     // Rda again as input parameter
6874     if (!Check(S, DecoderGPRRegisterClass(Inst, Rda, Address, Decoder)))
6875       return MCDisassembler::Fail;
6876 
6877     // Rm, the amount to shift by
6878     if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
6879       return MCDisassembler::Fail;
6880 
6881     if (fieldFromInstruction (Insn, 6, 3) != 4)
6882       return MCDisassembler::SoftFail;
6883 
6884     if (Rda == Rm)
6885       return MCDisassembler::SoftFail;
6886 
6887     return S;
6888   }
6889 
6890   // Otherwise, we decode as whichever opcode our caller has already
6891   // put into Inst. Those all look the same:
6892 
6893   // RdaLo,RdaHi as output parameters
6894   if (!Check(S, DecodetGPREvenRegisterClass(Inst, RdaLo, Address, Decoder)))
6895     return MCDisassembler::Fail;
6896   if (!Check(S, DecodetGPROddRegisterClass(Inst, RdaHi, Address, Decoder)))
6897     return MCDisassembler::Fail;
6898 
6899   // RdaLo,RdaHi again as input parameters
6900   if (!Check(S, DecodetGPREvenRegisterClass(Inst, RdaLo, Address, Decoder)))
6901     return MCDisassembler::Fail;
6902   if (!Check(S, DecodetGPROddRegisterClass(Inst, RdaHi, Address, Decoder)))
6903     return MCDisassembler::Fail;
6904 
6905   // Rm, the amount to shift by
6906   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
6907     return MCDisassembler::Fail;
6908 
6909   if (Inst.getOpcode() == ARM::MVE_SQRSHRL ||
6910       Inst.getOpcode() == ARM::MVE_UQRSHLL) {
6911     unsigned Saturate = fieldFromInstruction(Insn, 7, 1);
6912     // Saturate, the bit position for saturation
6913     Inst.addOperand(MCOperand::createImm(Saturate));
6914   }
6915 
6916   return S;
6917 }
6918 
6919 static DecodeStatus DecodeMVEVCVTt1fp(MCInst &Inst, unsigned Insn,
6920                                       uint64_t Address,
6921                                       const MCDisassembler *Decoder) {
6922   DecodeStatus S = MCDisassembler::Success;
6923   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
6924                  fieldFromInstruction(Insn, 13, 3));
6925   unsigned Qm = ((fieldFromInstruction(Insn, 5, 1) << 3) |
6926                  fieldFromInstruction(Insn, 1, 3));
6927   unsigned imm6 = fieldFromInstruction(Insn, 16, 6);
6928 
6929   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6930     return MCDisassembler::Fail;
6931   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
6932     return MCDisassembler::Fail;
6933   if (!Check(S, DecodeVCVTImmOperand(Inst, imm6, Address, Decoder)))
6934     return MCDisassembler::Fail;
6935 
6936   return S;
6937 }
6938 
6939 template <bool scalar, OperandDecoder predicate_decoder>
6940 static DecodeStatus DecodeMVEVCMP(MCInst &Inst, unsigned Insn, uint64_t Address,
6941                                   const MCDisassembler *Decoder) {
6942   DecodeStatus S = MCDisassembler::Success;
6943   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6944   unsigned Qn = fieldFromInstruction(Insn, 17, 3);
6945   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qn, Address, Decoder)))
6946     return MCDisassembler::Fail;
6947 
6948   unsigned fc;
6949 
6950   if (scalar) {
6951     fc = fieldFromInstruction(Insn, 12, 1) << 2 |
6952          fieldFromInstruction(Insn, 7, 1) |
6953          fieldFromInstruction(Insn, 5, 1) << 1;
6954     unsigned Rm = fieldFromInstruction(Insn, 0, 4);
6955     if (!Check(S, DecodeGPRwithZRRegisterClass(Inst, Rm, Address, Decoder)))
6956       return MCDisassembler::Fail;
6957   } else {
6958     fc = fieldFromInstruction(Insn, 12, 1) << 2 |
6959          fieldFromInstruction(Insn, 7, 1) |
6960          fieldFromInstruction(Insn, 0, 1) << 1;
6961     unsigned Qm = fieldFromInstruction(Insn, 5, 1) << 4 |
6962                   fieldFromInstruction(Insn, 1, 3);
6963     if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
6964       return MCDisassembler::Fail;
6965   }
6966 
6967   if (!Check(S, predicate_decoder(Inst, fc, Address, Decoder)))
6968     return MCDisassembler::Fail;
6969 
6970   Inst.addOperand(MCOperand::createImm(ARMVCC::None));
6971   Inst.addOperand(MCOperand::createReg(0));
6972   Inst.addOperand(MCOperand::createImm(0));
6973 
6974   return S;
6975 }
6976 
6977 static DecodeStatus DecodeMveVCTP(MCInst &Inst, unsigned Insn, uint64_t Address,
6978                                   const MCDisassembler *Decoder) {
6979   DecodeStatus S = MCDisassembler::Success;
6980   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6981   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
6982   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
6983     return MCDisassembler::Fail;
6984   return S;
6985 }
6986 
6987 static DecodeStatus DecodeMVEVPNOT(MCInst &Inst, unsigned Insn,
6988                                    uint64_t Address,
6989                                    const MCDisassembler *Decoder) {
6990   DecodeStatus S = MCDisassembler::Success;
6991   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6992   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6993   return S;
6994 }
6995 
6996 static DecodeStatus DecodeT2AddSubSPImm(MCInst &Inst, unsigned Insn,
6997                                         uint64_t Address,
6998                                         const MCDisassembler *Decoder) {
6999   const unsigned Rd = fieldFromInstruction(Insn, 8, 4);
7000   const unsigned Rn = fieldFromInstruction(Insn, 16, 4);
7001   const unsigned Imm12 = fieldFromInstruction(Insn, 26, 1) << 11 |
7002                          fieldFromInstruction(Insn, 12, 3) << 8 |
7003                          fieldFromInstruction(Insn, 0, 8);
7004   const unsigned TypeT3 = fieldFromInstruction(Insn, 25, 1);
7005   unsigned sign1 = fieldFromInstruction(Insn, 21, 1);
7006   unsigned sign2 = fieldFromInstruction(Insn, 23, 1);
7007   unsigned S = fieldFromInstruction(Insn, 20, 1);
7008   if (sign1 != sign2)
7009     return MCDisassembler::Fail;
7010 
7011   // T3 does a zext of imm12, where T2 does a ThumbExpandImm (T2SOImm)
7012   DecodeStatus DS = MCDisassembler::Success;
7013   if ((!Check(DS,
7014               DecodeGPRspRegisterClass(Inst, Rd, Address, Decoder))) || // dst
7015       (!Check(DS, DecodeGPRspRegisterClass(Inst, Rn, Address, Decoder))))
7016     return MCDisassembler::Fail;
7017   if (TypeT3) {
7018     Inst.setOpcode(sign1 ? ARM::t2SUBspImm12 : ARM::t2ADDspImm12);
7019     Inst.addOperand(MCOperand::createImm(Imm12)); // zext imm12
7020   } else {
7021     Inst.setOpcode(sign1 ? ARM::t2SUBspImm : ARM::t2ADDspImm);
7022     if (!Check(DS, DecodeT2SOImm(Inst, Imm12, Address, Decoder))) // imm12
7023       return MCDisassembler::Fail;
7024     if (!Check(DS, DecodeCCOutOperand(Inst, S, Address, Decoder))) // cc_out
7025       return MCDisassembler::Fail;
7026   }
7027 
7028   return DS;
7029 }
7030