xref: /freebsd-src/contrib/llvm-project/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp (revision fcaf7f8644a9988098ac6be2165bce3ea4786e91)
1 //===- ARMDisassembler.cpp - Disassembler for ARM/Thumb ISA ---------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "ARMBaseInstrInfo.h"
10 #include "MCTargetDesc/ARMAddressingModes.h"
11 #include "MCTargetDesc/ARMBaseInfo.h"
12 #include "MCTargetDesc/ARMMCTargetDesc.h"
13 #include "TargetInfo/ARMTargetInfo.h"
14 #include "Utils/ARMBaseInfo.h"
15 #include "llvm/MC/MCContext.h"
16 #include "llvm/MC/MCDecoderOps.h"
17 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
18 #include "llvm/MC/MCInst.h"
19 #include "llvm/MC/MCInstrDesc.h"
20 #include "llvm/MC/MCSubtargetInfo.h"
21 #include "llvm/MC/SubtargetFeature.h"
22 #include "llvm/MC/TargetRegistry.h"
23 #include "llvm/Support/Compiler.h"
24 #include "llvm/Support/ErrorHandling.h"
25 #include "llvm/Support/MathExtras.h"
26 #include "llvm/Support/raw_ostream.h"
27 #include <algorithm>
28 #include <cassert>
29 #include <cstdint>
30 #include <vector>
31 
32 using namespace llvm;
33 
34 #define DEBUG_TYPE "arm-disassembler"
35 
36 using DecodeStatus = MCDisassembler::DecodeStatus;
37 
38 namespace {
39 
40   // Handles the condition code status of instructions in IT blocks
41   class ITStatus
42   {
43     public:
44       // Returns the condition code for instruction in IT block
45       unsigned getITCC() {
46         unsigned CC = ARMCC::AL;
47         if (instrInITBlock())
48           CC = ITStates.back();
49         return CC;
50       }
51 
52       // Advances the IT block state to the next T or E
53       void advanceITState() {
54         ITStates.pop_back();
55       }
56 
57       // Returns true if the current instruction is in an IT block
58       bool instrInITBlock() {
59         return !ITStates.empty();
60       }
61 
62       // Returns true if current instruction is the last instruction in an IT block
63       bool instrLastInITBlock() {
64         return ITStates.size() == 1;
65       }
66 
67       // Called when decoding an IT instruction. Sets the IT state for
68       // the following instructions that for the IT block. Firstcond
69       // corresponds to the field in the IT instruction encoding; Mask
70       // is in the MCOperand format in which 1 means 'else' and 0 'then'.
71       void setITState(char Firstcond, char Mask) {
72         // (3 - the number of trailing zeros) is the number of then / else.
73         unsigned NumTZ = countTrailingZeros<uint8_t>(Mask);
74         unsigned char CCBits = static_cast<unsigned char>(Firstcond & 0xf);
75         assert(NumTZ <= 3 && "Invalid IT mask!");
76         // push condition codes onto the stack the correct order for the pops
77         for (unsigned Pos = NumTZ+1; Pos <= 3; ++Pos) {
78           unsigned Else = (Mask >> Pos) & 1;
79           ITStates.push_back(CCBits ^ Else);
80         }
81         ITStates.push_back(CCBits);
82       }
83 
84     private:
85       std::vector<unsigned char> ITStates;
86   };
87 
88   class VPTStatus
89   {
90     public:
91       unsigned getVPTPred() {
92         unsigned Pred = ARMVCC::None;
93         if (instrInVPTBlock())
94           Pred = VPTStates.back();
95         return Pred;
96       }
97 
98       void advanceVPTState() {
99         VPTStates.pop_back();
100       }
101 
102       bool instrInVPTBlock() {
103         return !VPTStates.empty();
104       }
105 
106       bool instrLastInVPTBlock() {
107         return VPTStates.size() == 1;
108       }
109 
110       void setVPTState(char Mask) {
111         // (3 - the number of trailing zeros) is the number of then / else.
112         unsigned NumTZ = countTrailingZeros<uint8_t>(Mask);
113         assert(NumTZ <= 3 && "Invalid VPT mask!");
114         // push predicates onto the stack the correct order for the pops
115         for (unsigned Pos = NumTZ+1; Pos <= 3; ++Pos) {
116           bool T = ((Mask >> Pos) & 1) == 0;
117           if (T)
118             VPTStates.push_back(ARMVCC::Then);
119           else
120             VPTStates.push_back(ARMVCC::Else);
121         }
122         VPTStates.push_back(ARMVCC::Then);
123       }
124 
125     private:
126       SmallVector<unsigned char, 4> VPTStates;
127   };
128 
129 /// ARM disassembler for all ARM platforms.
130 class ARMDisassembler : public MCDisassembler {
131 public:
132   ARMDisassembler(const MCSubtargetInfo &STI, MCContext &Ctx) :
133     MCDisassembler(STI, Ctx) {
134   }
135 
136   ~ARMDisassembler() override = default;
137 
138   DecodeStatus getInstruction(MCInst &Instr, uint64_t &Size,
139                               ArrayRef<uint8_t> Bytes, uint64_t Address,
140                               raw_ostream &CStream) const override;
141 
142 private:
143   DecodeStatus getARMInstruction(MCInst &Instr, uint64_t &Size,
144                                  ArrayRef<uint8_t> Bytes, uint64_t Address,
145                                  raw_ostream &CStream) const;
146 
147   DecodeStatus getThumbInstruction(MCInst &Instr, uint64_t &Size,
148                                    ArrayRef<uint8_t> Bytes, uint64_t Address,
149                                    raw_ostream &CStream) const;
150 
151   mutable ITStatus ITBlock;
152   mutable VPTStatus VPTBlock;
153 
154   DecodeStatus AddThumbPredicate(MCInst&) const;
155   void UpdateThumbVFPPredicate(DecodeStatus &, MCInst&) const;
156 };
157 
158 } // end anonymous namespace
159 
160 static bool Check(DecodeStatus &Out, DecodeStatus In) {
161   switch (In) {
162     case MCDisassembler::Success:
163       // Out stays the same.
164       return true;
165     case MCDisassembler::SoftFail:
166       Out = In;
167       return true;
168     case MCDisassembler::Fail:
169       Out = In;
170       return false;
171   }
172   llvm_unreachable("Invalid DecodeStatus!");
173 }
174 
175 // Forward declare these because the autogenerated code will reference them.
176 // Definitions are further down.
177 static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, unsigned RegNo,
178                                            uint64_t Address,
179                                            const MCDisassembler *Decoder);
180 static DecodeStatus DecodeCLRMGPRRegisterClass(MCInst &Inst, unsigned RegNo,
181                                                uint64_t Address,
182                                                const MCDisassembler *Decoder);
183 static DecodeStatus DecodetGPROddRegisterClass(MCInst &Inst, unsigned RegNo,
184                                                uint64_t Address,
185                                                const MCDisassembler *Decoder);
186 static DecodeStatus DecodetGPREvenRegisterClass(MCInst &Inst, unsigned RegNo,
187                                                 uint64_t Address,
188                                                 const MCDisassembler *Decoder);
189 static DecodeStatus
190 DecodeGPRwithAPSR_NZCVnospRegisterClass(MCInst &Inst, unsigned RegNo,
191                                         uint64_t Address,
192                                         const MCDisassembler *Decoder);
193 static DecodeStatus DecodeGPRnopcRegisterClass(MCInst &Inst, unsigned RegNo,
194                                                uint64_t Address,
195                                                const MCDisassembler *Decoder);
196 static DecodeStatus DecodeGPRnospRegisterClass(MCInst &Inst, unsigned RegNo,
197                                                uint64_t Address,
198                                                const MCDisassembler *Decoder);
199 static DecodeStatus
200 DecodeGPRwithAPSRRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Address,
201                                const MCDisassembler *Decoder);
202 static DecodeStatus DecodeGPRwithZRRegisterClass(MCInst &Inst, unsigned RegNo,
203                                                  uint64_t Address,
204                                                  const MCDisassembler *Decoder);
205 static DecodeStatus
206 DecodeGPRwithZRnospRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Address,
207                                  const MCDisassembler *Decoder);
208 static DecodeStatus DecodetGPRRegisterClass(MCInst &Inst, unsigned RegNo,
209                                             uint64_t Address,
210                                             const MCDisassembler *Decoder);
211 static DecodeStatus DecodetcGPRRegisterClass(MCInst &Inst, unsigned RegNo,
212                                              uint64_t Address,
213                                              const MCDisassembler *Decoder);
214 static DecodeStatus DecoderGPRRegisterClass(MCInst &Inst, unsigned RegNo,
215                                             uint64_t Address,
216                                             const MCDisassembler *Decoder);
217 static DecodeStatus DecodeGPRPairRegisterClass(MCInst &Inst, unsigned RegNo,
218                                                uint64_t Address,
219                                                const MCDisassembler *Decoder);
220 static DecodeStatus
221 DecodeGPRPairnospRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Address,
222                                const MCDisassembler *Decoder);
223 static DecodeStatus DecodeGPRspRegisterClass(MCInst &Inst, unsigned RegNo,
224                                              uint64_t Address,
225                                              const MCDisassembler *Decoder);
226 static DecodeStatus DecodeHPRRegisterClass(MCInst &Inst, unsigned RegNo,
227                                            uint64_t Address,
228                                            const MCDisassembler *Decoder);
229 static DecodeStatus DecodeSPRRegisterClass(MCInst &Inst, unsigned RegNo,
230                                            uint64_t Address,
231                                            const MCDisassembler *Decoder);
232 static DecodeStatus DecodeDPRRegisterClass(MCInst &Inst, unsigned RegNo,
233                                            uint64_t Address,
234                                            const MCDisassembler *Decoder);
235 static DecodeStatus DecodeDPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
236                                              uint64_t Address,
237                                              const MCDisassembler *Decoder);
238 static DecodeStatus DecodeSPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
239                                              uint64_t Address,
240                                              const MCDisassembler *Decoder);
241 static DecodeStatus DecodeDPR_VFP2RegisterClass(MCInst &Inst, unsigned RegNo,
242                                                 uint64_t Address,
243                                                 const MCDisassembler *Decoder);
244 static DecodeStatus DecodeQPRRegisterClass(MCInst &Inst, unsigned RegNo,
245                                            uint64_t Address,
246                                            const MCDisassembler *Decoder);
247 static DecodeStatus DecodeMQPRRegisterClass(MCInst &Inst, unsigned RegNo,
248                                             uint64_t Address,
249                                             const MCDisassembler *Decoder);
250 static DecodeStatus DecodeMQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
251                                              uint64_t Address,
252                                              const MCDisassembler *Decoder);
253 static DecodeStatus DecodeMQQQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
254                                                uint64_t Address,
255                                                const MCDisassembler *Decoder);
256 static DecodeStatus DecodeDPairRegisterClass(MCInst &Inst, unsigned RegNo,
257                                              uint64_t Address,
258                                              const MCDisassembler *Decoder);
259 static DecodeStatus
260 DecodeDPairSpacedRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Address,
261                                const MCDisassembler *Decoder);
262 
263 static DecodeStatus DecodePredicateOperand(MCInst &Inst, unsigned Val,
264                                            uint64_t Address,
265                                            const MCDisassembler *Decoder);
266 static DecodeStatus DecodeCCOutOperand(MCInst &Inst, unsigned Val,
267                                        uint64_t Address,
268                                        const MCDisassembler *Decoder);
269 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Val,
270                                          uint64_t Address,
271                                          const MCDisassembler *Decoder);
272 static DecodeStatus DecodeSPRRegListOperand(MCInst &Inst, unsigned Val,
273                                             uint64_t Address,
274                                             const MCDisassembler *Decoder);
275 static DecodeStatus DecodeDPRRegListOperand(MCInst &Inst, unsigned Val,
276                                             uint64_t Address,
277                                             const MCDisassembler *Decoder);
278 
279 static DecodeStatus DecodeBitfieldMaskOperand(MCInst &Inst, unsigned Insn,
280                                               uint64_t Address,
281                                               const MCDisassembler *Decoder);
282 static DecodeStatus DecodeCopMemInstruction(MCInst &Inst, unsigned Insn,
283                                             uint64_t Address,
284                                             const MCDisassembler *Decoder);
285 static DecodeStatus
286 DecodeAddrMode2IdxInstruction(MCInst &Inst, unsigned Insn, uint64_t Address,
287                               const MCDisassembler *Decoder);
288 static DecodeStatus DecodeSORegMemOperand(MCInst &Inst, unsigned Insn,
289                                           uint64_t Address,
290                                           const MCDisassembler *Decoder);
291 static DecodeStatus DecodeAddrMode3Instruction(MCInst &Inst, unsigned Insn,
292                                                uint64_t Address,
293                                                const MCDisassembler *Decoder);
294 static DecodeStatus DecodeTSBInstruction(MCInst &Inst, unsigned Insn,
295                                          uint64_t Address,
296                                          const MCDisassembler *Decoder);
297 static DecodeStatus DecodeSORegImmOperand(MCInst &Inst, unsigned Insn,
298                                           uint64_t Address,
299                                           const MCDisassembler *Decoder);
300 static DecodeStatus DecodeSORegRegOperand(MCInst &Inst, unsigned Insn,
301                                           uint64_t Address,
302                                           const MCDisassembler *Decoder);
303 
304 static DecodeStatus
305 DecodeMemMultipleWritebackInstruction(MCInst &Inst, unsigned Insn,
306                                       uint64_t Adddress,
307                                       const MCDisassembler *Decoder);
308 static DecodeStatus DecodeT2MOVTWInstruction(MCInst &Inst, unsigned Insn,
309                                              uint64_t Address,
310                                              const MCDisassembler *Decoder);
311 static DecodeStatus DecodeArmMOVTWInstruction(MCInst &Inst, unsigned Insn,
312                                               uint64_t Address,
313                                               const MCDisassembler *Decoder);
314 static DecodeStatus DecodeSMLAInstruction(MCInst &Inst, unsigned Insn,
315                                           uint64_t Address,
316                                           const MCDisassembler *Decoder);
317 static DecodeStatus DecodeHINTInstruction(MCInst &Inst, unsigned Insn,
318                                           uint64_t Address,
319                                           const MCDisassembler *Decoder);
320 static DecodeStatus DecodeCPSInstruction(MCInst &Inst, unsigned Insn,
321                                          uint64_t Address,
322                                          const MCDisassembler *Decoder);
323 static DecodeStatus DecodeTSTInstruction(MCInst &Inst, unsigned Insn,
324                                          uint64_t Address,
325                                          const MCDisassembler *Decoder);
326 static DecodeStatus DecodeSETPANInstruction(MCInst &Inst, unsigned Insn,
327                                             uint64_t Address,
328                                             const MCDisassembler *Decoder);
329 static DecodeStatus DecodeT2CPSInstruction(MCInst &Inst, unsigned Insn,
330                                            uint64_t Address,
331                                            const MCDisassembler *Decoder);
332 static DecodeStatus DecodeT2HintSpaceInstruction(MCInst &Inst, unsigned Insn,
333                                                  uint64_t Address,
334                                                  const MCDisassembler *Decoder);
335 static DecodeStatus DecodeAddrModeImm12Operand(MCInst &Inst, unsigned Val,
336                                                uint64_t Address,
337                                                const MCDisassembler *Decoder);
338 static DecodeStatus DecodeAddrMode5Operand(MCInst &Inst, unsigned Val,
339                                            uint64_t Address,
340                                            const MCDisassembler *Decoder);
341 static DecodeStatus DecodeAddrMode5FP16Operand(MCInst &Inst, unsigned Val,
342                                                uint64_t Address,
343                                                const MCDisassembler *Decoder);
344 static DecodeStatus DecodeAddrMode7Operand(MCInst &Inst, unsigned Val,
345                                            uint64_t Address,
346                                            const MCDisassembler *Decoder);
347 static DecodeStatus DecodeT2BInstruction(MCInst &Inst, unsigned Insn,
348                                          uint64_t Address,
349                                          const MCDisassembler *Decoder);
350 static DecodeStatus DecodeBranchImmInstruction(MCInst &Inst, unsigned Insn,
351                                                uint64_t Address,
352                                                const MCDisassembler *Decoder);
353 static DecodeStatus DecodeAddrMode6Operand(MCInst &Inst, unsigned Val,
354                                            uint64_t Address,
355                                            const MCDisassembler *Decoder);
356 static DecodeStatus DecodeVLDST1Instruction(MCInst &Inst, unsigned Val,
357                                             uint64_t Address,
358                                             const MCDisassembler *Decoder);
359 static DecodeStatus DecodeVLDST2Instruction(MCInst &Inst, unsigned Val,
360                                             uint64_t Address,
361                                             const MCDisassembler *Decoder);
362 static DecodeStatus DecodeVLDST3Instruction(MCInst &Inst, unsigned Val,
363                                             uint64_t Address,
364                                             const MCDisassembler *Decoder);
365 static DecodeStatus DecodeVLDST4Instruction(MCInst &Inst, unsigned Val,
366                                             uint64_t Address,
367                                             const MCDisassembler *Decoder);
368 static DecodeStatus DecodeVLDInstruction(MCInst &Inst, unsigned Val,
369                                          uint64_t Address,
370                                          const MCDisassembler *Decoder);
371 static DecodeStatus DecodeVSTInstruction(MCInst &Inst, unsigned Val,
372                                          uint64_t Address,
373                                          const MCDisassembler *Decoder);
374 static DecodeStatus DecodeVLD1DupInstruction(MCInst &Inst, unsigned Val,
375                                              uint64_t Address,
376                                              const MCDisassembler *Decoder);
377 static DecodeStatus DecodeVLD2DupInstruction(MCInst &Inst, unsigned Val,
378                                              uint64_t Address,
379                                              const MCDisassembler *Decoder);
380 static DecodeStatus DecodeVLD3DupInstruction(MCInst &Inst, unsigned Val,
381                                              uint64_t Address,
382                                              const MCDisassembler *Decoder);
383 static DecodeStatus DecodeVLD4DupInstruction(MCInst &Inst, unsigned Val,
384                                              uint64_t Address,
385                                              const MCDisassembler *Decoder);
386 static DecodeStatus DecodeVMOVModImmInstruction(MCInst &Inst, unsigned Val,
387                                                 uint64_t Address,
388                                                 const MCDisassembler *Decoder);
389 static DecodeStatus DecodeMVEModImmInstruction(MCInst &Inst, unsigned Val,
390                                                uint64_t Address,
391                                                const MCDisassembler *Decoder);
392 static DecodeStatus DecodeMVEVADCInstruction(MCInst &Inst, unsigned Insn,
393                                              uint64_t Address,
394                                              const MCDisassembler *Decoder);
395 static DecodeStatus DecodeVSHLMaxInstruction(MCInst &Inst, unsigned Val,
396                                              uint64_t Address,
397                                              const MCDisassembler *Decoder);
398 static DecodeStatus DecodeShiftRight8Imm(MCInst &Inst, unsigned Val,
399                                          uint64_t Address,
400                                          const MCDisassembler *Decoder);
401 static DecodeStatus DecodeShiftRight16Imm(MCInst &Inst, unsigned Val,
402                                           uint64_t Address,
403                                           const MCDisassembler *Decoder);
404 static DecodeStatus DecodeShiftRight32Imm(MCInst &Inst, unsigned Val,
405                                           uint64_t Address,
406                                           const MCDisassembler *Decoder);
407 static DecodeStatus DecodeShiftRight64Imm(MCInst &Inst, unsigned Val,
408                                           uint64_t Address,
409                                           const MCDisassembler *Decoder);
410 static DecodeStatus DecodeTBLInstruction(MCInst &Inst, unsigned Insn,
411                                          uint64_t Address,
412                                          const MCDisassembler *Decoder);
413 static DecodeStatus DecodePostIdxReg(MCInst &Inst, unsigned Insn,
414                                      uint64_t Address,
415                                      const MCDisassembler *Decoder);
416 static DecodeStatus DecodeMveAddrModeRQ(MCInst &Inst, unsigned Insn,
417                                         uint64_t Address,
418                                         const MCDisassembler *Decoder);
419 template <int shift>
420 static DecodeStatus DecodeMveAddrModeQ(MCInst &Inst, unsigned Insn,
421                                        uint64_t Address,
422                                        const MCDisassembler *Decoder);
423 static DecodeStatus DecodeCoprocessor(MCInst &Inst, unsigned Insn,
424                                       uint64_t Address,
425                                       const MCDisassembler *Decoder);
426 static DecodeStatus DecodeMemBarrierOption(MCInst &Inst, unsigned Insn,
427                                            uint64_t Address,
428                                            const MCDisassembler *Decoder);
429 static DecodeStatus DecodeInstSyncBarrierOption(MCInst &Inst, unsigned Insn,
430                                                 uint64_t Address,
431                                                 const MCDisassembler *Decoder);
432 static DecodeStatus DecodeMSRMask(MCInst &Inst, unsigned Insn, uint64_t Address,
433                                   const MCDisassembler *Decoder);
434 static DecodeStatus DecodeBankedReg(MCInst &Inst, unsigned Insn,
435                                     uint64_t Address,
436                                     const MCDisassembler *Decoder);
437 static DecodeStatus DecodeDoubleRegLoad(MCInst &Inst, unsigned Insn,
438                                         uint64_t Address,
439                                         const MCDisassembler *Decoder);
440 static DecodeStatus DecodeDoubleRegStore(MCInst &Inst, unsigned Insn,
441                                          uint64_t Address,
442                                          const MCDisassembler *Decoder);
443 static DecodeStatus DecodeLDRPreImm(MCInst &Inst, unsigned Insn,
444                                     uint64_t Address,
445                                     const MCDisassembler *Decoder);
446 static DecodeStatus DecodeLDRPreReg(MCInst &Inst, unsigned Insn,
447                                     uint64_t Address,
448                                     const MCDisassembler *Decoder);
449 static DecodeStatus DecodeSTRPreImm(MCInst &Inst, unsigned Insn,
450                                     uint64_t Address,
451                                     const MCDisassembler *Decoder);
452 static DecodeStatus DecodeSTRPreReg(MCInst &Inst, unsigned Insn,
453                                     uint64_t Address,
454                                     const MCDisassembler *Decoder);
455 static DecodeStatus DecodeVLD1LN(MCInst &Inst, unsigned Insn, uint64_t Address,
456                                  const MCDisassembler *Decoder);
457 static DecodeStatus DecodeVLD2LN(MCInst &Inst, unsigned Insn, uint64_t Address,
458                                  const MCDisassembler *Decoder);
459 static DecodeStatus DecodeVLD3LN(MCInst &Inst, unsigned Insn, uint64_t Address,
460                                  const MCDisassembler *Decoder);
461 static DecodeStatus DecodeVLD4LN(MCInst &Inst, unsigned Insn, uint64_t Address,
462                                  const MCDisassembler *Decoder);
463 static DecodeStatus DecodeVST1LN(MCInst &Inst, unsigned Insn, uint64_t Address,
464                                  const MCDisassembler *Decoder);
465 static DecodeStatus DecodeVST2LN(MCInst &Inst, unsigned Insn, uint64_t Address,
466                                  const MCDisassembler *Decoder);
467 static DecodeStatus DecodeVST3LN(MCInst &Inst, unsigned Insn, uint64_t Address,
468                                  const MCDisassembler *Decoder);
469 static DecodeStatus DecodeVST4LN(MCInst &Inst, unsigned Insn, uint64_t Address,
470                                  const MCDisassembler *Decoder);
471 static DecodeStatus DecodeVMOVSRR(MCInst &Inst, unsigned Insn, uint64_t Address,
472                                   const MCDisassembler *Decoder);
473 static DecodeStatus DecodeVMOVRRS(MCInst &Inst, unsigned Insn, uint64_t Address,
474                                   const MCDisassembler *Decoder);
475 static DecodeStatus DecodeSwap(MCInst &Inst, unsigned Insn, uint64_t Address,
476                                const MCDisassembler *Decoder);
477 static DecodeStatus DecodeVCVTD(MCInst &Inst, unsigned Insn, uint64_t Address,
478                                 const MCDisassembler *Decoder);
479 static DecodeStatus DecodeVCVTQ(MCInst &Inst, unsigned Insn, uint64_t Address,
480                                 const MCDisassembler *Decoder);
481 static DecodeStatus DecodeVCVTImmOperand(MCInst &Inst, unsigned Insn,
482                                          uint64_t Address,
483                                          const MCDisassembler *Decoder);
484 static DecodeStatus
485 DecodeNEONComplexLane64Instruction(MCInst &Inst, unsigned Val, uint64_t Address,
486                                    const MCDisassembler *Decoder);
487 
488 static DecodeStatus DecodeThumbAddSpecialReg(MCInst &Inst, uint16_t Insn,
489                                              uint64_t Address,
490                                              const MCDisassembler *Decoder);
491 static DecodeStatus DecodeThumbBROperand(MCInst &Inst, unsigned Val,
492                                          uint64_t Address,
493                                          const MCDisassembler *Decoder);
494 static DecodeStatus DecodeT2BROperand(MCInst &Inst, unsigned Val,
495                                       uint64_t Address,
496                                       const MCDisassembler *Decoder);
497 static DecodeStatus DecodeThumbCmpBROperand(MCInst &Inst, unsigned Val,
498                                             uint64_t Address,
499                                             const MCDisassembler *Decoder);
500 static DecodeStatus DecodeThumbAddrModeRR(MCInst &Inst, unsigned Val,
501                                           uint64_t Address,
502                                           const MCDisassembler *Decoder);
503 static DecodeStatus DecodeThumbAddrModeIS(MCInst &Inst, unsigned Val,
504                                           uint64_t Address,
505                                           const MCDisassembler *Decoder);
506 static DecodeStatus DecodeThumbAddrModePC(MCInst &Inst, unsigned Val,
507                                           uint64_t Address,
508                                           const MCDisassembler *Decoder);
509 static DecodeStatus DecodeThumbAddrModeSP(MCInst &Inst, unsigned Val,
510                                           uint64_t Address,
511                                           const MCDisassembler *Decoder);
512 static DecodeStatus DecodeT2AddrModeSOReg(MCInst &Inst, unsigned Val,
513                                           uint64_t Address,
514                                           const MCDisassembler *Decoder);
515 static DecodeStatus DecodeT2LoadShift(MCInst &Inst, unsigned Val,
516                                       uint64_t Address,
517                                       const MCDisassembler *Decoder);
518 static DecodeStatus DecodeT2LoadImm8(MCInst &Inst, unsigned Insn,
519                                      uint64_t Address,
520                                      const MCDisassembler *Decoder);
521 static DecodeStatus DecodeT2LoadImm12(MCInst &Inst, unsigned Insn,
522                                       uint64_t Address,
523                                       const MCDisassembler *Decoder);
524 static DecodeStatus DecodeT2LoadT(MCInst &Inst, unsigned Insn, uint64_t Address,
525                                   const MCDisassembler *Decoder);
526 static DecodeStatus DecodeT2LoadLabel(MCInst &Inst, unsigned Insn,
527                                       uint64_t Address,
528                                       const MCDisassembler *Decoder);
529 static DecodeStatus DecodeT2Imm8S4(MCInst &Inst, unsigned Val, uint64_t Address,
530                                    const MCDisassembler *Decoder);
531 static DecodeStatus DecodeT2Imm7S4(MCInst &Inst, unsigned Val, uint64_t Address,
532                                    const MCDisassembler *Decoder);
533 static DecodeStatus DecodeT2AddrModeImm8s4(MCInst &Inst, unsigned Val,
534                                            uint64_t Address,
535                                            const MCDisassembler *Decoder);
536 static DecodeStatus DecodeT2AddrModeImm7s4(MCInst &Inst, unsigned Val,
537                                            uint64_t Address,
538                                            const MCDisassembler *Decoder);
539 static DecodeStatus DecodeT2AddrModeImm0_1020s4(MCInst &Inst, unsigned Val,
540                                                 uint64_t Address,
541                                                 const MCDisassembler *Decoder);
542 static DecodeStatus DecodeT2Imm8(MCInst &Inst, unsigned Val, uint64_t Address,
543                                  const MCDisassembler *Decoder);
544 template <int shift>
545 static DecodeStatus DecodeT2Imm7(MCInst &Inst, unsigned Val, uint64_t Address,
546                                  const MCDisassembler *Decoder);
547 static DecodeStatus DecodeT2AddrModeImm8(MCInst &Inst, unsigned Val,
548                                          uint64_t Address,
549                                          const MCDisassembler *Decoder);
550 template <int shift>
551 static DecodeStatus DecodeTAddrModeImm7(MCInst &Inst, unsigned Val,
552                                         uint64_t Address,
553                                         const MCDisassembler *Decoder);
554 template <int shift, int WriteBack>
555 static DecodeStatus DecodeT2AddrModeImm7(MCInst &Inst, unsigned Val,
556                                          uint64_t Address,
557                                          const MCDisassembler *Decoder);
558 static DecodeStatus DecodeThumbAddSPImm(MCInst &Inst, uint16_t Val,
559                                         uint64_t Address,
560                                         const MCDisassembler *Decoder);
561 static DecodeStatus DecodeThumbAddSPReg(MCInst &Inst, uint16_t Insn,
562                                         uint64_t Address,
563                                         const MCDisassembler *Decoder);
564 static DecodeStatus DecodeThumbCPS(MCInst &Inst, uint16_t Insn,
565                                    uint64_t Address,
566                                    const MCDisassembler *Decoder);
567 static DecodeStatus DecodeQADDInstruction(MCInst &Inst, unsigned Insn,
568                                           uint64_t Address,
569                                           const MCDisassembler *Decoder);
570 static DecodeStatus DecodeThumbBLXOffset(MCInst &Inst, unsigned Insn,
571                                          uint64_t Address,
572                                          const MCDisassembler *Decoder);
573 static DecodeStatus DecodeT2AddrModeImm12(MCInst &Inst, unsigned Val,
574                                           uint64_t Address,
575                                           const MCDisassembler *Decoder);
576 static DecodeStatus DecodeThumbTableBranch(MCInst &Inst, unsigned Val,
577                                            uint64_t Address,
578                                            const MCDisassembler *Decoder);
579 static DecodeStatus DecodeThumb2BCCInstruction(MCInst &Inst, unsigned Val,
580                                                uint64_t Address,
581                                                const MCDisassembler *Decoder);
582 static DecodeStatus DecodeT2SOImm(MCInst &Inst, unsigned Val, uint64_t Address,
583                                   const MCDisassembler *Decoder);
584 static DecodeStatus DecodeThumbBCCTargetOperand(MCInst &Inst, unsigned Val,
585                                                 uint64_t Address,
586                                                 const MCDisassembler *Decoder);
587 static DecodeStatus DecodeThumbBLTargetOperand(MCInst &Inst, unsigned Val,
588                                                uint64_t Address,
589                                                const MCDisassembler *Decoder);
590 static DecodeStatus DecodeIT(MCInst &Inst, unsigned Val, uint64_t Address,
591                              const MCDisassembler *Decoder);
592 static DecodeStatus DecodeT2LDRDPreInstruction(MCInst &Inst, unsigned Insn,
593                                                uint64_t Address,
594                                                const MCDisassembler *Decoder);
595 static DecodeStatus DecodeT2STRDPreInstruction(MCInst &Inst, unsigned Insn,
596                                                uint64_t Address,
597                                                const MCDisassembler *Decoder);
598 static DecodeStatus DecodeT2Adr(MCInst &Inst, unsigned Val, uint64_t Address,
599                                 const MCDisassembler *Decoder);
600 static DecodeStatus DecodeT2LdStPre(MCInst &Inst, unsigned Val,
601                                     uint64_t Address,
602                                     const MCDisassembler *Decoder);
603 static DecodeStatus DecodeT2ShifterImmOperand(MCInst &Inst, unsigned Val,
604                                               uint64_t Address,
605                                               const MCDisassembler *Decoder);
606 
607 static DecodeStatus DecodeLDR(MCInst &Inst, unsigned Val, uint64_t Address,
608                               const MCDisassembler *Decoder);
609 static DecodeStatus DecoderForMRRC2AndMCRR2(MCInst &Inst, unsigned Val,
610                                             uint64_t Address,
611                                             const MCDisassembler *Decoder);
612 static DecodeStatus DecodeForVMRSandVMSR(MCInst &Inst, unsigned Val,
613                                          uint64_t Address,
614                                          const MCDisassembler *Decoder);
615 
616 template <bool isSigned, bool isNeg, bool zeroPermitted, int size>
617 static DecodeStatus DecodeBFLabelOperand(MCInst &Inst, unsigned val,
618                                          uint64_t Address,
619                                          const MCDisassembler *Decoder);
620 static DecodeStatus DecodeBFAfterTargetOperand(MCInst &Inst, unsigned val,
621                                                uint64_t Address,
622                                                const MCDisassembler *Decoder);
623 static DecodeStatus DecodePredNoALOperand(MCInst &Inst, unsigned Val,
624                                           uint64_t Address,
625                                           const MCDisassembler *Decoder);
626 static DecodeStatus DecodeLOLoop(MCInst &Inst, unsigned Insn, uint64_t Address,
627                                  const MCDisassembler *Decoder);
628 static DecodeStatus DecodeLongShiftOperand(MCInst &Inst, unsigned Val,
629                                            uint64_t Address,
630                                            const MCDisassembler *Decoder);
631 static DecodeStatus DecodeVSCCLRM(MCInst &Inst, unsigned Insn, uint64_t Address,
632                                   const MCDisassembler *Decoder);
633 static DecodeStatus DecodeVPTMaskOperand(MCInst &Inst, unsigned Val,
634                                          uint64_t Address,
635                                          const MCDisassembler *Decoder);
636 static DecodeStatus DecodeVpredROperand(MCInst &Inst, unsigned Val,
637                                         uint64_t Address,
638                                         const MCDisassembler *Decoder);
639 static DecodeStatus
640 DecodeRestrictedIPredicateOperand(MCInst &Inst, unsigned Val, uint64_t Address,
641                                   const MCDisassembler *Decoder);
642 static DecodeStatus
643 DecodeRestrictedSPredicateOperand(MCInst &Inst, unsigned Val, uint64_t Address,
644                                   const MCDisassembler *Decoder);
645 static DecodeStatus
646 DecodeRestrictedUPredicateOperand(MCInst &Inst, unsigned Val, uint64_t Address,
647                                   const MCDisassembler *Decoder);
648 static DecodeStatus
649 DecodeRestrictedFPPredicateOperand(MCInst &Inst, unsigned Val, uint64_t Address,
650                                    const MCDisassembler *Decoder);
651 template <bool Writeback>
652 static DecodeStatus DecodeVSTRVLDR_SYSREG(MCInst &Inst, unsigned Insn,
653                                           uint64_t Address,
654                                           const MCDisassembler *Decoder);
655 template <int shift>
656 static DecodeStatus DecodeMVE_MEM_1_pre(MCInst &Inst, unsigned Val,
657                                         uint64_t Address,
658                                         const MCDisassembler *Decoder);
659 template <int shift>
660 static DecodeStatus DecodeMVE_MEM_2_pre(MCInst &Inst, unsigned Val,
661                                         uint64_t Address,
662                                         const MCDisassembler *Decoder);
663 template <int shift>
664 static DecodeStatus DecodeMVE_MEM_3_pre(MCInst &Inst, unsigned Val,
665                                         uint64_t Address,
666                                         const MCDisassembler *Decoder);
667 template <unsigned MinLog, unsigned MaxLog>
668 static DecodeStatus DecodePowerTwoOperand(MCInst &Inst, unsigned Val,
669                                           uint64_t Address,
670                                           const MCDisassembler *Decoder);
671 template <unsigned start>
672 static DecodeStatus
673 DecodeMVEPairVectorIndexOperand(MCInst &Inst, unsigned Val, uint64_t Address,
674                                 const MCDisassembler *Decoder);
675 static DecodeStatus DecodeMVEVMOVQtoDReg(MCInst &Inst, unsigned Insn,
676                                          uint64_t Address,
677                                          const MCDisassembler *Decoder);
678 static DecodeStatus DecodeMVEVMOVDRegtoQ(MCInst &Inst, unsigned Insn,
679                                          uint64_t Address,
680                                          const MCDisassembler *Decoder);
681 static DecodeStatus DecodeMVEVCVTt1fp(MCInst &Inst, unsigned Insn,
682                                       uint64_t Address,
683                                       const MCDisassembler *Decoder);
684 typedef DecodeStatus OperandDecoder(MCInst &Inst, unsigned Val,
685                                     uint64_t Address,
686                                     const MCDisassembler *Decoder);
687 template <bool scalar, OperandDecoder predicate_decoder>
688 static DecodeStatus DecodeMVEVCMP(MCInst &Inst, unsigned Insn, uint64_t Address,
689                                   const MCDisassembler *Decoder);
690 static DecodeStatus DecodeMveVCTP(MCInst &Inst, unsigned Insn, uint64_t Address,
691                                   const MCDisassembler *Decoder);
692 static DecodeStatus DecodeMVEVPNOT(MCInst &Inst, unsigned Insn,
693                                    uint64_t Address,
694                                    const MCDisassembler *Decoder);
695 static DecodeStatus
696 DecodeMVEOverlappingLongShift(MCInst &Inst, unsigned Insn, uint64_t Address,
697                               const MCDisassembler *Decoder);
698 static DecodeStatus DecodeT2AddSubSPImm(MCInst &Inst, unsigned Insn,
699                                         uint64_t Address,
700                                         const MCDisassembler *Decoder);
701 
702 #include "ARMGenDisassemblerTables.inc"
703 
704 static MCDisassembler *createARMDisassembler(const Target &T,
705                                              const MCSubtargetInfo &STI,
706                                              MCContext &Ctx) {
707   return new ARMDisassembler(STI, Ctx);
708 }
709 
710 // Post-decoding checks
711 static DecodeStatus checkDecodedInstruction(MCInst &MI, uint64_t &Size,
712                                             uint64_t Address, raw_ostream &CS,
713                                             uint32_t Insn,
714                                             DecodeStatus Result) {
715   switch (MI.getOpcode()) {
716     case ARM::HVC: {
717       // HVC is undefined if condition = 0xf otherwise upredictable
718       // if condition != 0xe
719       uint32_t Cond = (Insn >> 28) & 0xF;
720       if (Cond == 0xF)
721         return MCDisassembler::Fail;
722       if (Cond != 0xE)
723         return MCDisassembler::SoftFail;
724       return Result;
725     }
726     case ARM::t2ADDri:
727     case ARM::t2ADDri12:
728     case ARM::t2ADDrr:
729     case ARM::t2ADDrs:
730     case ARM::t2SUBri:
731     case ARM::t2SUBri12:
732     case ARM::t2SUBrr:
733     case ARM::t2SUBrs:
734       if (MI.getOperand(0).getReg() == ARM::SP &&
735           MI.getOperand(1).getReg() != ARM::SP)
736         return MCDisassembler::SoftFail;
737       return Result;
738     default: return Result;
739   }
740 }
741 
742 DecodeStatus ARMDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
743                                              ArrayRef<uint8_t> Bytes,
744                                              uint64_t Address,
745                                              raw_ostream &CS) const {
746   if (STI.getFeatureBits()[ARM::ModeThumb])
747     return getThumbInstruction(MI, Size, Bytes, Address, CS);
748   return getARMInstruction(MI, Size, Bytes, Address, CS);
749 }
750 
751 DecodeStatus ARMDisassembler::getARMInstruction(MCInst &MI, uint64_t &Size,
752                                                 ArrayRef<uint8_t> Bytes,
753                                                 uint64_t Address,
754                                                 raw_ostream &CS) const {
755   CommentStream = &CS;
756 
757   assert(!STI.getFeatureBits()[ARM::ModeThumb] &&
758          "Asked to disassemble an ARM instruction but Subtarget is in Thumb "
759          "mode!");
760 
761   // We want to read exactly 4 bytes of data.
762   if (Bytes.size() < 4) {
763     Size = 0;
764     return MCDisassembler::Fail;
765   }
766 
767   // Encoded as a small-endian 32-bit word in the stream.
768   uint32_t Insn =
769       (Bytes[3] << 24) | (Bytes[2] << 16) | (Bytes[1] << 8) | (Bytes[0] << 0);
770 
771   // Calling the auto-generated decoder function.
772   DecodeStatus Result =
773       decodeInstruction(DecoderTableARM32, MI, Insn, Address, this, STI);
774   if (Result != MCDisassembler::Fail) {
775     Size = 4;
776     return checkDecodedInstruction(MI, Size, Address, CS, Insn, Result);
777   }
778 
779   struct DecodeTable {
780     const uint8_t *P;
781     bool DecodePred;
782   };
783 
784   const DecodeTable Tables[] = {
785       {DecoderTableVFP32, false},      {DecoderTableVFPV832, false},
786       {DecoderTableNEONData32, true},  {DecoderTableNEONLoadStore32, true},
787       {DecoderTableNEONDup32, true},   {DecoderTablev8NEON32, false},
788       {DecoderTablev8Crypto32, false},
789   };
790 
791   for (auto Table : Tables) {
792     Result = decodeInstruction(Table.P, MI, Insn, Address, this, STI);
793     if (Result != MCDisassembler::Fail) {
794       Size = 4;
795       // Add a fake predicate operand, because we share these instruction
796       // definitions with Thumb2 where these instructions are predicable.
797       if (Table.DecodePred && !DecodePredicateOperand(MI, 0xE, Address, this))
798         return MCDisassembler::Fail;
799       return Result;
800     }
801   }
802 
803   Result =
804       decodeInstruction(DecoderTableCoProc32, MI, Insn, Address, this, STI);
805   if (Result != MCDisassembler::Fail) {
806     Size = 4;
807     return checkDecodedInstruction(MI, Size, Address, CS, Insn, Result);
808   }
809 
810   Size = 4;
811   return MCDisassembler::Fail;
812 }
813 
814 namespace llvm {
815 
816 extern const MCInstrDesc ARMInsts[];
817 
818 } // end namespace llvm
819 
820 /// tryAddingSymbolicOperand - trys to add a symbolic operand in place of the
821 /// immediate Value in the MCInst.  The immediate Value has had any PC
822 /// adjustment made by the caller.  If the instruction is a branch instruction
823 /// then isBranch is true, else false.  If the getOpInfo() function was set as
824 /// part of the setupForSymbolicDisassembly() call then that function is called
825 /// to get any symbolic information at the Address for this instruction.  If
826 /// that returns non-zero then the symbolic information it returns is used to
827 /// create an MCExpr and that is added as an operand to the MCInst.  If
828 /// getOpInfo() returns zero and isBranch is true then a symbol look up for
829 /// Value is done and if a symbol is found an MCExpr is created with that, else
830 /// an MCExpr with Value is created.  This function returns true if it adds an
831 /// operand to the MCInst and false otherwise.
832 static bool tryAddingSymbolicOperand(uint64_t Address, int32_t Value,
833                                      bool isBranch, uint64_t InstSize,
834                                      MCInst &MI,
835                                      const MCDisassembler *Decoder) {
836   // FIXME: Does it make sense for value to be negative?
837   return Decoder->tryAddingSymbolicOperand(MI, (uint32_t)Value, Address,
838                                            isBranch, /*Offset=*/0, /*OpSize=*/0,
839                                            InstSize);
840 }
841 
842 /// tryAddingPcLoadReferenceComment - trys to add a comment as to what is being
843 /// referenced by a load instruction with the base register that is the Pc.
844 /// These can often be values in a literal pool near the Address of the
845 /// instruction.  The Address of the instruction and its immediate Value are
846 /// used as a possible literal pool entry.  The SymbolLookUp call back will
847 /// return the name of a symbol referenced by the literal pool's entry if
848 /// the referenced address is that of a symbol.  Or it will return a pointer to
849 /// a literal 'C' string if the referenced address of the literal pool's entry
850 /// is an address into a section with 'C' string literals.
851 static void tryAddingPcLoadReferenceComment(uint64_t Address, int Value,
852                                             const MCDisassembler *Decoder) {
853   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
854   Dis->tryAddingPcLoadReferenceComment(Value, Address);
855 }
856 
857 // Thumb1 instructions don't have explicit S bits.  Rather, they
858 // implicitly set CPSR.  Since it's not represented in the encoding, the
859 // auto-generated decoder won't inject the CPSR operand.  We need to fix
860 // that as a post-pass.
861 static void AddThumb1SBit(MCInst &MI, bool InITBlock) {
862   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
863   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
864   MCInst::iterator I = MI.begin();
865   for (unsigned i = 0; i < NumOps; ++i, ++I) {
866     if (I == MI.end()) break;
867     if (OpInfo[i].isOptionalDef() && OpInfo[i].RegClass == ARM::CCRRegClassID) {
868       if (i > 0 && OpInfo[i-1].isPredicate()) continue;
869       MI.insert(I, MCOperand::createReg(InITBlock ? 0 : ARM::CPSR));
870       return;
871     }
872   }
873 
874   MI.insert(I, MCOperand::createReg(InITBlock ? 0 : ARM::CPSR));
875 }
876 
877 static bool isVectorPredicable(unsigned Opcode) {
878   const MCOperandInfo *OpInfo = ARMInsts[Opcode].OpInfo;
879   unsigned short NumOps = ARMInsts[Opcode].NumOperands;
880   for (unsigned i = 0; i < NumOps; ++i) {
881     if (ARM::isVpred(OpInfo[i].OperandType))
882       return true;
883   }
884   return false;
885 }
886 
887 // Most Thumb instructions don't have explicit predicates in the
888 // encoding, but rather get their predicates from IT context.  We need
889 // to fix up the predicate operands using this context information as a
890 // post-pass.
891 MCDisassembler::DecodeStatus
892 ARMDisassembler::AddThumbPredicate(MCInst &MI) const {
893   MCDisassembler::DecodeStatus S = Success;
894 
895   const FeatureBitset &FeatureBits = getSubtargetInfo().getFeatureBits();
896 
897   // A few instructions actually have predicates encoded in them.  Don't
898   // try to overwrite it if we're seeing one of those.
899   switch (MI.getOpcode()) {
900     case ARM::tBcc:
901     case ARM::t2Bcc:
902     case ARM::tCBZ:
903     case ARM::tCBNZ:
904     case ARM::tCPS:
905     case ARM::t2CPS3p:
906     case ARM::t2CPS2p:
907     case ARM::t2CPS1p:
908     case ARM::t2CSEL:
909     case ARM::t2CSINC:
910     case ARM::t2CSINV:
911     case ARM::t2CSNEG:
912     case ARM::tMOVSr:
913     case ARM::tSETEND:
914       // Some instructions (mostly conditional branches) are not
915       // allowed in IT blocks.
916       if (ITBlock.instrInITBlock())
917         S = SoftFail;
918       else
919         return Success;
920       break;
921     case ARM::t2HINT:
922       if (MI.getOperand(0).getImm() == 0x10 && (FeatureBits[ARM::FeatureRAS]) != 0)
923         S = SoftFail;
924       break;
925     case ARM::tB:
926     case ARM::t2B:
927     case ARM::t2TBB:
928     case ARM::t2TBH:
929       // Some instructions (mostly unconditional branches) can
930       // only appears at the end of, or outside of, an IT.
931       if (ITBlock.instrInITBlock() && !ITBlock.instrLastInITBlock())
932         S = SoftFail;
933       break;
934     default:
935       break;
936   }
937 
938   // Warn on non-VPT predicable instruction in a VPT block and a VPT
939   // predicable instruction in an IT block
940   if ((!isVectorPredicable(MI.getOpcode()) && VPTBlock.instrInVPTBlock()) ||
941        (isVectorPredicable(MI.getOpcode()) && ITBlock.instrInITBlock()))
942     S = SoftFail;
943 
944   // If we're in an IT/VPT block, base the predicate on that.  Otherwise,
945   // assume a predicate of AL.
946   unsigned CC = ARMCC::AL;
947   unsigned VCC = ARMVCC::None;
948   if (ITBlock.instrInITBlock()) {
949     CC = ITBlock.getITCC();
950     ITBlock.advanceITState();
951   } else if (VPTBlock.instrInVPTBlock()) {
952     VCC = VPTBlock.getVPTPred();
953     VPTBlock.advanceVPTState();
954   }
955 
956   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
957   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
958 
959   MCInst::iterator CCI = MI.begin();
960   for (unsigned i = 0; i < NumOps; ++i, ++CCI) {
961     if (OpInfo[i].isPredicate() || CCI == MI.end()) break;
962   }
963 
964   if (ARMInsts[MI.getOpcode()].isPredicable()) {
965     CCI = MI.insert(CCI, MCOperand::createImm(CC));
966     ++CCI;
967     if (CC == ARMCC::AL)
968       MI.insert(CCI, MCOperand::createReg(0));
969     else
970       MI.insert(CCI, MCOperand::createReg(ARM::CPSR));
971   } else if (CC != ARMCC::AL) {
972     Check(S, SoftFail);
973   }
974 
975   MCInst::iterator VCCI = MI.begin();
976   unsigned VCCPos;
977   for (VCCPos = 0; VCCPos < NumOps; ++VCCPos, ++VCCI) {
978     if (ARM::isVpred(OpInfo[VCCPos].OperandType) || VCCI == MI.end()) break;
979   }
980 
981   if (isVectorPredicable(MI.getOpcode())) {
982     VCCI = MI.insert(VCCI, MCOperand::createImm(VCC));
983     ++VCCI;
984     if (VCC == ARMVCC::None)
985       VCCI = MI.insert(VCCI, MCOperand::createReg(0));
986     else
987       VCCI = MI.insert(VCCI, MCOperand::createReg(ARM::P0));
988     ++VCCI;
989     VCCI = MI.insert(VCCI, MCOperand::createReg(0));
990     ++VCCI;
991     if (OpInfo[VCCPos].OperandType == ARM::OPERAND_VPRED_R) {
992       int TiedOp = ARMInsts[MI.getOpcode()].getOperandConstraint(
993         VCCPos + 3, MCOI::TIED_TO);
994       assert(TiedOp >= 0 &&
995              "Inactive register in vpred_r is not tied to an output!");
996       // Copy the operand to ensure it's not invalidated when MI grows.
997       MI.insert(VCCI, MCOperand(MI.getOperand(TiedOp)));
998     }
999   } else if (VCC != ARMVCC::None) {
1000     Check(S, SoftFail);
1001   }
1002 
1003   return S;
1004 }
1005 
1006 // Thumb VFP instructions are a special case.  Because we share their
1007 // encodings between ARM and Thumb modes, and they are predicable in ARM
1008 // mode, the auto-generated decoder will give them an (incorrect)
1009 // predicate operand.  We need to rewrite these operands based on the IT
1010 // context as a post-pass.
1011 void ARMDisassembler::UpdateThumbVFPPredicate(
1012   DecodeStatus &S, MCInst &MI) const {
1013   unsigned CC;
1014   CC = ITBlock.getITCC();
1015   if (CC == 0xF)
1016     CC = ARMCC::AL;
1017   if (ITBlock.instrInITBlock())
1018     ITBlock.advanceITState();
1019   else if (VPTBlock.instrInVPTBlock()) {
1020     CC = VPTBlock.getVPTPred();
1021     VPTBlock.advanceVPTState();
1022   }
1023 
1024   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
1025   MCInst::iterator I = MI.begin();
1026   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
1027   for (unsigned i = 0; i < NumOps; ++i, ++I) {
1028     if (OpInfo[i].isPredicate() ) {
1029       if (CC != ARMCC::AL && !ARMInsts[MI.getOpcode()].isPredicable())
1030         Check(S, SoftFail);
1031       I->setImm(CC);
1032       ++I;
1033       if (CC == ARMCC::AL)
1034         I->setReg(0);
1035       else
1036         I->setReg(ARM::CPSR);
1037       return;
1038     }
1039   }
1040 }
1041 
1042 DecodeStatus ARMDisassembler::getThumbInstruction(MCInst &MI, uint64_t &Size,
1043                                                   ArrayRef<uint8_t> Bytes,
1044                                                   uint64_t Address,
1045                                                   raw_ostream &CS) const {
1046   CommentStream = &CS;
1047 
1048   assert(STI.getFeatureBits()[ARM::ModeThumb] &&
1049          "Asked to disassemble in Thumb mode but Subtarget is in ARM mode!");
1050 
1051   // We want to read exactly 2 bytes of data.
1052   if (Bytes.size() < 2) {
1053     Size = 0;
1054     return MCDisassembler::Fail;
1055   }
1056 
1057   uint16_t Insn16 = (Bytes[1] << 8) | Bytes[0];
1058   DecodeStatus Result =
1059       decodeInstruction(DecoderTableThumb16, MI, Insn16, Address, this, STI);
1060   if (Result != MCDisassembler::Fail) {
1061     Size = 2;
1062     Check(Result, AddThumbPredicate(MI));
1063     return Result;
1064   }
1065 
1066   Result = decodeInstruction(DecoderTableThumbSBit16, MI, Insn16, Address, this,
1067                              STI);
1068   if (Result) {
1069     Size = 2;
1070     bool InITBlock = ITBlock.instrInITBlock();
1071     Check(Result, AddThumbPredicate(MI));
1072     AddThumb1SBit(MI, InITBlock);
1073     return Result;
1074   }
1075 
1076   Result =
1077       decodeInstruction(DecoderTableThumb216, MI, Insn16, Address, this, STI);
1078   if (Result != MCDisassembler::Fail) {
1079     Size = 2;
1080 
1081     // Nested IT blocks are UNPREDICTABLE.  Must be checked before we add
1082     // the Thumb predicate.
1083     if (MI.getOpcode() == ARM::t2IT && ITBlock.instrInITBlock())
1084       Result = MCDisassembler::SoftFail;
1085 
1086     Check(Result, AddThumbPredicate(MI));
1087 
1088     // If we find an IT instruction, we need to parse its condition
1089     // code and mask operands so that we can apply them correctly
1090     // to the subsequent instructions.
1091     if (MI.getOpcode() == ARM::t2IT) {
1092       unsigned Firstcond = MI.getOperand(0).getImm();
1093       unsigned Mask = MI.getOperand(1).getImm();
1094       ITBlock.setITState(Firstcond, Mask);
1095 
1096       // An IT instruction that would give a 'NV' predicate is unpredictable.
1097       if (Firstcond == ARMCC::AL && !isPowerOf2_32(Mask))
1098         CS << "unpredictable IT predicate sequence";
1099     }
1100 
1101     return Result;
1102   }
1103 
1104   // We want to read exactly 4 bytes of data.
1105   if (Bytes.size() < 4) {
1106     Size = 0;
1107     return MCDisassembler::Fail;
1108   }
1109 
1110   uint32_t Insn32 =
1111       (Bytes[3] << 8) | (Bytes[2] << 0) | (Bytes[1] << 24) | (Bytes[0] << 16);
1112 
1113   Result =
1114       decodeInstruction(DecoderTableMVE32, MI, Insn32, Address, this, STI);
1115   if (Result != MCDisassembler::Fail) {
1116     Size = 4;
1117 
1118     // Nested VPT blocks are UNPREDICTABLE. Must be checked before we add
1119     // the VPT predicate.
1120     if (isVPTOpcode(MI.getOpcode()) && VPTBlock.instrInVPTBlock())
1121       Result = MCDisassembler::SoftFail;
1122 
1123     Check(Result, AddThumbPredicate(MI));
1124 
1125     if (isVPTOpcode(MI.getOpcode())) {
1126       unsigned Mask = MI.getOperand(0).getImm();
1127       VPTBlock.setVPTState(Mask);
1128     }
1129 
1130     return Result;
1131   }
1132 
1133   Result =
1134       decodeInstruction(DecoderTableThumb32, MI, Insn32, Address, this, STI);
1135   if (Result != MCDisassembler::Fail) {
1136     Size = 4;
1137     bool InITBlock = ITBlock.instrInITBlock();
1138     Check(Result, AddThumbPredicate(MI));
1139     AddThumb1SBit(MI, InITBlock);
1140     return Result;
1141   }
1142 
1143   Result =
1144       decodeInstruction(DecoderTableThumb232, MI, Insn32, Address, this, STI);
1145   if (Result != MCDisassembler::Fail) {
1146     Size = 4;
1147     Check(Result, AddThumbPredicate(MI));
1148     return checkDecodedInstruction(MI, Size, Address, CS, Insn32, Result);
1149   }
1150 
1151   if (fieldFromInstruction(Insn32, 28, 4) == 0xE) {
1152     Result =
1153         decodeInstruction(DecoderTableVFP32, MI, Insn32, Address, this, STI);
1154     if (Result != MCDisassembler::Fail) {
1155       Size = 4;
1156       UpdateThumbVFPPredicate(Result, MI);
1157       return Result;
1158     }
1159   }
1160 
1161   Result =
1162       decodeInstruction(DecoderTableVFPV832, MI, Insn32, Address, this, STI);
1163   if (Result != MCDisassembler::Fail) {
1164     Size = 4;
1165     return Result;
1166   }
1167 
1168   if (fieldFromInstruction(Insn32, 28, 4) == 0xE) {
1169     Result = decodeInstruction(DecoderTableNEONDup32, MI, Insn32, Address, this,
1170                                STI);
1171     if (Result != MCDisassembler::Fail) {
1172       Size = 4;
1173       Check(Result, AddThumbPredicate(MI));
1174       return Result;
1175     }
1176   }
1177 
1178   if (fieldFromInstruction(Insn32, 24, 8) == 0xF9) {
1179     uint32_t NEONLdStInsn = Insn32;
1180     NEONLdStInsn &= 0xF0FFFFFF;
1181     NEONLdStInsn |= 0x04000000;
1182     Result = decodeInstruction(DecoderTableNEONLoadStore32, MI, NEONLdStInsn,
1183                                Address, this, STI);
1184     if (Result != MCDisassembler::Fail) {
1185       Size = 4;
1186       Check(Result, AddThumbPredicate(MI));
1187       return Result;
1188     }
1189   }
1190 
1191   if (fieldFromInstruction(Insn32, 24, 4) == 0xF) {
1192     uint32_t NEONDataInsn = Insn32;
1193     NEONDataInsn &= 0xF0FFFFFF; // Clear bits 27-24
1194     NEONDataInsn |= (NEONDataInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
1195     NEONDataInsn |= 0x12000000; // Set bits 28 and 25
1196     Result = decodeInstruction(DecoderTableNEONData32, MI, NEONDataInsn,
1197                                Address, this, STI);
1198     if (Result != MCDisassembler::Fail) {
1199       Size = 4;
1200       Check(Result, AddThumbPredicate(MI));
1201       return Result;
1202     }
1203 
1204     uint32_t NEONCryptoInsn = Insn32;
1205     NEONCryptoInsn &= 0xF0FFFFFF; // Clear bits 27-24
1206     NEONCryptoInsn |= (NEONCryptoInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
1207     NEONCryptoInsn |= 0x12000000; // Set bits 28 and 25
1208     Result = decodeInstruction(DecoderTablev8Crypto32, MI, NEONCryptoInsn,
1209                                Address, this, STI);
1210     if (Result != MCDisassembler::Fail) {
1211       Size = 4;
1212       return Result;
1213     }
1214 
1215     uint32_t NEONv8Insn = Insn32;
1216     NEONv8Insn &= 0xF3FFFFFF; // Clear bits 27-26
1217     Result = decodeInstruction(DecoderTablev8NEON32, MI, NEONv8Insn, Address,
1218                                this, STI);
1219     if (Result != MCDisassembler::Fail) {
1220       Size = 4;
1221       return Result;
1222     }
1223   }
1224 
1225   uint32_t Coproc = fieldFromInstruction(Insn32, 8, 4);
1226   const uint8_t *DecoderTable = ARM::isCDECoproc(Coproc, STI)
1227                                     ? DecoderTableThumb2CDE32
1228                                     : DecoderTableThumb2CoProc32;
1229   Result =
1230       decodeInstruction(DecoderTable, MI, Insn32, Address, this, STI);
1231   if (Result != MCDisassembler::Fail) {
1232     Size = 4;
1233     Check(Result, AddThumbPredicate(MI));
1234     return Result;
1235   }
1236 
1237   Size = 0;
1238   return MCDisassembler::Fail;
1239 }
1240 
1241 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeARMDisassembler() {
1242   TargetRegistry::RegisterMCDisassembler(getTheARMLETarget(),
1243                                          createARMDisassembler);
1244   TargetRegistry::RegisterMCDisassembler(getTheARMBETarget(),
1245                                          createARMDisassembler);
1246   TargetRegistry::RegisterMCDisassembler(getTheThumbLETarget(),
1247                                          createARMDisassembler);
1248   TargetRegistry::RegisterMCDisassembler(getTheThumbBETarget(),
1249                                          createARMDisassembler);
1250 }
1251 
1252 static const uint16_t GPRDecoderTable[] = {
1253   ARM::R0, ARM::R1, ARM::R2, ARM::R3,
1254   ARM::R4, ARM::R5, ARM::R6, ARM::R7,
1255   ARM::R8, ARM::R9, ARM::R10, ARM::R11,
1256   ARM::R12, ARM::SP, ARM::LR, ARM::PC
1257 };
1258 
1259 static const uint16_t CLRMGPRDecoderTable[] = {
1260   ARM::R0, ARM::R1, ARM::R2, ARM::R3,
1261   ARM::R4, ARM::R5, ARM::R6, ARM::R7,
1262   ARM::R8, ARM::R9, ARM::R10, ARM::R11,
1263   ARM::R12, 0, ARM::LR, ARM::APSR
1264 };
1265 
1266 static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1267                                            uint64_t Address,
1268                                            const MCDisassembler *Decoder) {
1269   if (RegNo > 15)
1270     return MCDisassembler::Fail;
1271 
1272   unsigned Register = GPRDecoderTable[RegNo];
1273   Inst.addOperand(MCOperand::createReg(Register));
1274   return MCDisassembler::Success;
1275 }
1276 
1277 static DecodeStatus DecodeCLRMGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1278                                                uint64_t Address,
1279                                                const MCDisassembler *Decoder) {
1280   if (RegNo > 15)
1281     return MCDisassembler::Fail;
1282 
1283   unsigned Register = CLRMGPRDecoderTable[RegNo];
1284   if (Register == 0)
1285     return MCDisassembler::Fail;
1286 
1287   Inst.addOperand(MCOperand::createReg(Register));
1288   return MCDisassembler::Success;
1289 }
1290 
1291 static DecodeStatus DecodeGPRnopcRegisterClass(MCInst &Inst, unsigned RegNo,
1292                                                uint64_t Address,
1293                                                const MCDisassembler *Decoder) {
1294   DecodeStatus S = MCDisassembler::Success;
1295 
1296   if (RegNo == 15)
1297     S = MCDisassembler::SoftFail;
1298 
1299   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1300 
1301   return S;
1302 }
1303 
1304 static DecodeStatus DecodeGPRnospRegisterClass(MCInst &Inst, unsigned RegNo,
1305                                                uint64_t Address,
1306                                                const MCDisassembler *Decoder) {
1307   DecodeStatus S = MCDisassembler::Success;
1308 
1309   if (RegNo == 13)
1310     S = MCDisassembler::SoftFail;
1311 
1312   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1313 
1314   return S;
1315 }
1316 
1317 static DecodeStatus
1318 DecodeGPRwithAPSRRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Address,
1319                                const MCDisassembler *Decoder) {
1320   DecodeStatus S = MCDisassembler::Success;
1321 
1322   if (RegNo == 15)
1323   {
1324     Inst.addOperand(MCOperand::createReg(ARM::APSR_NZCV));
1325     return MCDisassembler::Success;
1326   }
1327 
1328   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1329   return S;
1330 }
1331 
1332 static DecodeStatus
1333 DecodeGPRwithZRRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Address,
1334                              const MCDisassembler *Decoder) {
1335   DecodeStatus S = MCDisassembler::Success;
1336 
1337   if (RegNo == 15)
1338   {
1339     Inst.addOperand(MCOperand::createReg(ARM::ZR));
1340     return MCDisassembler::Success;
1341   }
1342 
1343   if (RegNo == 13)
1344     Check(S, MCDisassembler::SoftFail);
1345 
1346   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1347   return S;
1348 }
1349 
1350 static DecodeStatus
1351 DecodeGPRwithZRnospRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Address,
1352                                  const MCDisassembler *Decoder) {
1353   DecodeStatus S = MCDisassembler::Success;
1354   if (RegNo == 13)
1355     return MCDisassembler::Fail;
1356   Check(S, DecodeGPRwithZRRegisterClass(Inst, RegNo, Address, Decoder));
1357   return S;
1358 }
1359 
1360 static DecodeStatus DecodetGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1361                                             uint64_t Address,
1362                                             const MCDisassembler *Decoder) {
1363   if (RegNo > 7)
1364     return MCDisassembler::Fail;
1365   return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
1366 }
1367 
1368 static const uint16_t GPRPairDecoderTable[] = {
1369   ARM::R0_R1, ARM::R2_R3,   ARM::R4_R5,  ARM::R6_R7,
1370   ARM::R8_R9, ARM::R10_R11, ARM::R12_SP
1371 };
1372 
1373 static DecodeStatus DecodeGPRPairRegisterClass(MCInst &Inst, unsigned RegNo,
1374                                                uint64_t Address,
1375                                                const MCDisassembler *Decoder) {
1376   DecodeStatus S = MCDisassembler::Success;
1377 
1378   // According to the Arm ARM RegNo = 14 is undefined, but we return fail
1379   // rather than SoftFail as there is no GPRPair table entry for index 7.
1380   if (RegNo > 13)
1381     return MCDisassembler::Fail;
1382 
1383   if (RegNo & 1)
1384      S = MCDisassembler::SoftFail;
1385 
1386   unsigned RegisterPair = GPRPairDecoderTable[RegNo/2];
1387   Inst.addOperand(MCOperand::createReg(RegisterPair));
1388   return S;
1389 }
1390 
1391 static DecodeStatus
1392 DecodeGPRPairnospRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Address,
1393                                const MCDisassembler *Decoder) {
1394   if (RegNo > 13)
1395     return MCDisassembler::Fail;
1396 
1397   unsigned RegisterPair = GPRPairDecoderTable[RegNo/2];
1398   Inst.addOperand(MCOperand::createReg(RegisterPair));
1399 
1400   if ((RegNo & 1) || RegNo > 10)
1401      return MCDisassembler::SoftFail;
1402   return MCDisassembler::Success;
1403 }
1404 
1405 static DecodeStatus DecodeGPRspRegisterClass(MCInst &Inst, unsigned RegNo,
1406                                              uint64_t Address,
1407                                              const MCDisassembler *Decoder) {
1408   if (RegNo != 13)
1409     return MCDisassembler::Fail;
1410 
1411   unsigned Register = GPRDecoderTable[RegNo];
1412   Inst.addOperand(MCOperand::createReg(Register));
1413   return MCDisassembler::Success;
1414 }
1415 
1416 static DecodeStatus DecodetcGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1417                                              uint64_t Address,
1418                                              const MCDisassembler *Decoder) {
1419   unsigned Register = 0;
1420   switch (RegNo) {
1421     case 0:
1422       Register = ARM::R0;
1423       break;
1424     case 1:
1425       Register = ARM::R1;
1426       break;
1427     case 2:
1428       Register = ARM::R2;
1429       break;
1430     case 3:
1431       Register = ARM::R3;
1432       break;
1433     case 9:
1434       Register = ARM::R9;
1435       break;
1436     case 12:
1437       Register = ARM::R12;
1438       break;
1439     default:
1440       return MCDisassembler::Fail;
1441     }
1442 
1443   Inst.addOperand(MCOperand::createReg(Register));
1444   return MCDisassembler::Success;
1445 }
1446 
1447 static DecodeStatus DecoderGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1448                                             uint64_t Address,
1449                                             const MCDisassembler *Decoder) {
1450   DecodeStatus S = MCDisassembler::Success;
1451 
1452   const FeatureBitset &featureBits =
1453     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1454 
1455   if ((RegNo == 13 && !featureBits[ARM::HasV8Ops]) || RegNo == 15)
1456     S = MCDisassembler::SoftFail;
1457 
1458   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1459   return S;
1460 }
1461 
1462 static const uint16_t SPRDecoderTable[] = {
1463      ARM::S0,  ARM::S1,  ARM::S2,  ARM::S3,
1464      ARM::S4,  ARM::S5,  ARM::S6,  ARM::S7,
1465      ARM::S8,  ARM::S9, ARM::S10, ARM::S11,
1466     ARM::S12, ARM::S13, ARM::S14, ARM::S15,
1467     ARM::S16, ARM::S17, ARM::S18, ARM::S19,
1468     ARM::S20, ARM::S21, ARM::S22, ARM::S23,
1469     ARM::S24, ARM::S25, ARM::S26, ARM::S27,
1470     ARM::S28, ARM::S29, ARM::S30, ARM::S31
1471 };
1472 
1473 static DecodeStatus DecodeSPRRegisterClass(MCInst &Inst, unsigned RegNo,
1474                                            uint64_t Address,
1475                                            const MCDisassembler *Decoder) {
1476   if (RegNo > 31)
1477     return MCDisassembler::Fail;
1478 
1479   unsigned Register = SPRDecoderTable[RegNo];
1480   Inst.addOperand(MCOperand::createReg(Register));
1481   return MCDisassembler::Success;
1482 }
1483 
1484 static DecodeStatus DecodeHPRRegisterClass(MCInst &Inst, unsigned RegNo,
1485                                            uint64_t Address,
1486                                            const MCDisassembler *Decoder) {
1487   return DecodeSPRRegisterClass(Inst, RegNo, Address, Decoder);
1488 }
1489 
1490 static const uint16_t DPRDecoderTable[] = {
1491      ARM::D0,  ARM::D1,  ARM::D2,  ARM::D3,
1492      ARM::D4,  ARM::D5,  ARM::D6,  ARM::D7,
1493      ARM::D8,  ARM::D9, ARM::D10, ARM::D11,
1494     ARM::D12, ARM::D13, ARM::D14, ARM::D15,
1495     ARM::D16, ARM::D17, ARM::D18, ARM::D19,
1496     ARM::D20, ARM::D21, ARM::D22, ARM::D23,
1497     ARM::D24, ARM::D25, ARM::D26, ARM::D27,
1498     ARM::D28, ARM::D29, ARM::D30, ARM::D31
1499 };
1500 
1501 static DecodeStatus DecodeDPRRegisterClass(MCInst &Inst, unsigned RegNo,
1502                                            uint64_t Address,
1503                                            const MCDisassembler *Decoder) {
1504   const FeatureBitset &featureBits =
1505     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1506 
1507   bool hasD32 = featureBits[ARM::FeatureD32];
1508 
1509   if (RegNo > 31 || (!hasD32 && RegNo > 15))
1510     return MCDisassembler::Fail;
1511 
1512   unsigned Register = DPRDecoderTable[RegNo];
1513   Inst.addOperand(MCOperand::createReg(Register));
1514   return MCDisassembler::Success;
1515 }
1516 
1517 static DecodeStatus DecodeDPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
1518                                              uint64_t Address,
1519                                              const MCDisassembler *Decoder) {
1520   if (RegNo > 7)
1521     return MCDisassembler::Fail;
1522   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
1523 }
1524 
1525 static DecodeStatus DecodeSPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
1526                                              uint64_t Address,
1527                                              const MCDisassembler *Decoder) {
1528   if (RegNo > 15)
1529     return MCDisassembler::Fail;
1530   return DecodeSPRRegisterClass(Inst, RegNo, Address, Decoder);
1531 }
1532 
1533 static DecodeStatus DecodeDPR_VFP2RegisterClass(MCInst &Inst, unsigned RegNo,
1534                                                 uint64_t Address,
1535                                                 const MCDisassembler *Decoder) {
1536   if (RegNo > 15)
1537     return MCDisassembler::Fail;
1538   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
1539 }
1540 
1541 static const uint16_t QPRDecoderTable[] = {
1542      ARM::Q0,  ARM::Q1,  ARM::Q2,  ARM::Q3,
1543      ARM::Q4,  ARM::Q5,  ARM::Q6,  ARM::Q7,
1544      ARM::Q8,  ARM::Q9, ARM::Q10, ARM::Q11,
1545     ARM::Q12, ARM::Q13, ARM::Q14, ARM::Q15
1546 };
1547 
1548 static DecodeStatus DecodeQPRRegisterClass(MCInst &Inst, unsigned RegNo,
1549                                            uint64_t Address,
1550                                            const MCDisassembler *Decoder) {
1551   if (RegNo > 31 || (RegNo & 1) != 0)
1552     return MCDisassembler::Fail;
1553   RegNo >>= 1;
1554 
1555   unsigned Register = QPRDecoderTable[RegNo];
1556   Inst.addOperand(MCOperand::createReg(Register));
1557   return MCDisassembler::Success;
1558 }
1559 
1560 static const uint16_t DPairDecoderTable[] = {
1561   ARM::Q0,  ARM::D1_D2,   ARM::Q1,  ARM::D3_D4,   ARM::Q2,  ARM::D5_D6,
1562   ARM::Q3,  ARM::D7_D8,   ARM::Q4,  ARM::D9_D10,  ARM::Q5,  ARM::D11_D12,
1563   ARM::Q6,  ARM::D13_D14, ARM::Q7,  ARM::D15_D16, ARM::Q8,  ARM::D17_D18,
1564   ARM::Q9,  ARM::D19_D20, ARM::Q10, ARM::D21_D22, ARM::Q11, ARM::D23_D24,
1565   ARM::Q12, ARM::D25_D26, ARM::Q13, ARM::D27_D28, ARM::Q14, ARM::D29_D30,
1566   ARM::Q15
1567 };
1568 
1569 static DecodeStatus DecodeDPairRegisterClass(MCInst &Inst, unsigned RegNo,
1570                                              uint64_t Address,
1571                                              const MCDisassembler *Decoder) {
1572   if (RegNo > 30)
1573     return MCDisassembler::Fail;
1574 
1575   unsigned Register = DPairDecoderTable[RegNo];
1576   Inst.addOperand(MCOperand::createReg(Register));
1577   return MCDisassembler::Success;
1578 }
1579 
1580 static const uint16_t DPairSpacedDecoderTable[] = {
1581   ARM::D0_D2,   ARM::D1_D3,   ARM::D2_D4,   ARM::D3_D5,
1582   ARM::D4_D6,   ARM::D5_D7,   ARM::D6_D8,   ARM::D7_D9,
1583   ARM::D8_D10,  ARM::D9_D11,  ARM::D10_D12, ARM::D11_D13,
1584   ARM::D12_D14, ARM::D13_D15, ARM::D14_D16, ARM::D15_D17,
1585   ARM::D16_D18, ARM::D17_D19, ARM::D18_D20, ARM::D19_D21,
1586   ARM::D20_D22, ARM::D21_D23, ARM::D22_D24, ARM::D23_D25,
1587   ARM::D24_D26, ARM::D25_D27, ARM::D26_D28, ARM::D27_D29,
1588   ARM::D28_D30, ARM::D29_D31
1589 };
1590 
1591 static DecodeStatus
1592 DecodeDPairSpacedRegisterClass(MCInst &Inst, unsigned RegNo, uint64_t Address,
1593                                const MCDisassembler *Decoder) {
1594   if (RegNo > 29)
1595     return MCDisassembler::Fail;
1596 
1597   unsigned Register = DPairSpacedDecoderTable[RegNo];
1598   Inst.addOperand(MCOperand::createReg(Register));
1599   return MCDisassembler::Success;
1600 }
1601 
1602 static DecodeStatus DecodePredicateOperand(MCInst &Inst, unsigned Val,
1603                                            uint64_t Address,
1604                                            const MCDisassembler *Decoder) {
1605   DecodeStatus S = MCDisassembler::Success;
1606   if (Val == 0xF) return MCDisassembler::Fail;
1607   // AL predicate is not allowed on Thumb1 branches.
1608   if (Inst.getOpcode() == ARM::tBcc && Val == 0xE)
1609     return MCDisassembler::Fail;
1610   if (Val != ARMCC::AL && !ARMInsts[Inst.getOpcode()].isPredicable())
1611     Check(S, MCDisassembler::SoftFail);
1612   Inst.addOperand(MCOperand::createImm(Val));
1613   if (Val == ARMCC::AL) {
1614     Inst.addOperand(MCOperand::createReg(0));
1615   } else
1616     Inst.addOperand(MCOperand::createReg(ARM::CPSR));
1617   return S;
1618 }
1619 
1620 static DecodeStatus DecodeCCOutOperand(MCInst &Inst, unsigned Val,
1621                                        uint64_t Address,
1622                                        const MCDisassembler *Decoder) {
1623   if (Val)
1624     Inst.addOperand(MCOperand::createReg(ARM::CPSR));
1625   else
1626     Inst.addOperand(MCOperand::createReg(0));
1627   return MCDisassembler::Success;
1628 }
1629 
1630 static DecodeStatus DecodeSORegImmOperand(MCInst &Inst, unsigned Val,
1631                                           uint64_t Address,
1632                                           const MCDisassembler *Decoder) {
1633   DecodeStatus S = MCDisassembler::Success;
1634 
1635   unsigned Rm = fieldFromInstruction(Val, 0, 4);
1636   unsigned type = fieldFromInstruction(Val, 5, 2);
1637   unsigned imm = fieldFromInstruction(Val, 7, 5);
1638 
1639   // Register-immediate
1640   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
1641     return MCDisassembler::Fail;
1642 
1643   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1644   switch (type) {
1645     case 0:
1646       Shift = ARM_AM::lsl;
1647       break;
1648     case 1:
1649       Shift = ARM_AM::lsr;
1650       break;
1651     case 2:
1652       Shift = ARM_AM::asr;
1653       break;
1654     case 3:
1655       Shift = ARM_AM::ror;
1656       break;
1657   }
1658 
1659   if (Shift == ARM_AM::ror && imm == 0)
1660     Shift = ARM_AM::rrx;
1661 
1662   unsigned Op = Shift | (imm << 3);
1663   Inst.addOperand(MCOperand::createImm(Op));
1664 
1665   return S;
1666 }
1667 
1668 static DecodeStatus DecodeSORegRegOperand(MCInst &Inst, unsigned Val,
1669                                           uint64_t Address,
1670                                           const MCDisassembler *Decoder) {
1671   DecodeStatus S = MCDisassembler::Success;
1672 
1673   unsigned Rm = fieldFromInstruction(Val, 0, 4);
1674   unsigned type = fieldFromInstruction(Val, 5, 2);
1675   unsigned Rs = fieldFromInstruction(Val, 8, 4);
1676 
1677   // Register-register
1678   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1679     return MCDisassembler::Fail;
1680   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rs, Address, Decoder)))
1681     return MCDisassembler::Fail;
1682 
1683   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1684   switch (type) {
1685     case 0:
1686       Shift = ARM_AM::lsl;
1687       break;
1688     case 1:
1689       Shift = ARM_AM::lsr;
1690       break;
1691     case 2:
1692       Shift = ARM_AM::asr;
1693       break;
1694     case 3:
1695       Shift = ARM_AM::ror;
1696       break;
1697   }
1698 
1699   Inst.addOperand(MCOperand::createImm(Shift));
1700 
1701   return S;
1702 }
1703 
1704 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Val,
1705                                          uint64_t Address,
1706                                          const MCDisassembler *Decoder) {
1707   DecodeStatus S = MCDisassembler::Success;
1708 
1709   bool NeedDisjointWriteback = false;
1710   unsigned WritebackReg = 0;
1711   bool CLRM = false;
1712   switch (Inst.getOpcode()) {
1713   default:
1714     break;
1715   case ARM::LDMIA_UPD:
1716   case ARM::LDMDB_UPD:
1717   case ARM::LDMIB_UPD:
1718   case ARM::LDMDA_UPD:
1719   case ARM::t2LDMIA_UPD:
1720   case ARM::t2LDMDB_UPD:
1721   case ARM::t2STMIA_UPD:
1722   case ARM::t2STMDB_UPD:
1723     NeedDisjointWriteback = true;
1724     WritebackReg = Inst.getOperand(0).getReg();
1725     break;
1726   case ARM::t2CLRM:
1727     CLRM = true;
1728     break;
1729   }
1730 
1731   // Empty register lists are not allowed.
1732   if (Val == 0) return MCDisassembler::Fail;
1733   for (unsigned i = 0; i < 16; ++i) {
1734     if (Val & (1 << i)) {
1735       if (CLRM) {
1736         if (!Check(S, DecodeCLRMGPRRegisterClass(Inst, i, Address, Decoder))) {
1737           return MCDisassembler::Fail;
1738         }
1739       } else {
1740         if (!Check(S, DecodeGPRRegisterClass(Inst, i, Address, Decoder)))
1741           return MCDisassembler::Fail;
1742         // Writeback not allowed if Rn is in the target list.
1743         if (NeedDisjointWriteback && WritebackReg == Inst.end()[-1].getReg())
1744           Check(S, MCDisassembler::SoftFail);
1745       }
1746     }
1747   }
1748 
1749   return S;
1750 }
1751 
1752 static DecodeStatus DecodeSPRRegListOperand(MCInst &Inst, unsigned Val,
1753                                             uint64_t Address,
1754                                             const MCDisassembler *Decoder) {
1755   DecodeStatus S = MCDisassembler::Success;
1756 
1757   unsigned Vd = fieldFromInstruction(Val, 8, 5);
1758   unsigned regs = fieldFromInstruction(Val, 0, 8);
1759 
1760   // In case of unpredictable encoding, tweak the operands.
1761   if (regs == 0 || (Vd + regs) > 32) {
1762     regs = Vd + regs > 32 ? 32 - Vd : regs;
1763     regs = std::max( 1u, regs);
1764     S = MCDisassembler::SoftFail;
1765   }
1766 
1767   if (!Check(S, DecodeSPRRegisterClass(Inst, Vd, Address, Decoder)))
1768     return MCDisassembler::Fail;
1769   for (unsigned i = 0; i < (regs - 1); ++i) {
1770     if (!Check(S, DecodeSPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1771       return MCDisassembler::Fail;
1772   }
1773 
1774   return S;
1775 }
1776 
1777 static DecodeStatus DecodeDPRRegListOperand(MCInst &Inst, unsigned Val,
1778                                             uint64_t Address,
1779                                             const MCDisassembler *Decoder) {
1780   DecodeStatus S = MCDisassembler::Success;
1781 
1782   unsigned Vd = fieldFromInstruction(Val, 8, 5);
1783   unsigned regs = fieldFromInstruction(Val, 1, 7);
1784 
1785   // In case of unpredictable encoding, tweak the operands.
1786   if (regs == 0 || regs > 16 || (Vd + regs) > 32) {
1787     regs = Vd + regs > 32 ? 32 - Vd : regs;
1788     regs = std::max( 1u, regs);
1789     regs = std::min(16u, regs);
1790     S = MCDisassembler::SoftFail;
1791   }
1792 
1793   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
1794       return MCDisassembler::Fail;
1795   for (unsigned i = 0; i < (regs - 1); ++i) {
1796     if (!Check(S, DecodeDPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1797       return MCDisassembler::Fail;
1798   }
1799 
1800   return S;
1801 }
1802 
1803 static DecodeStatus DecodeBitfieldMaskOperand(MCInst &Inst, unsigned Val,
1804                                               uint64_t Address,
1805                                               const MCDisassembler *Decoder) {
1806   // This operand encodes a mask of contiguous zeros between a specified MSB
1807   // and LSB.  To decode it, we create the mask of all bits MSB-and-lower,
1808   // the mask of all bits LSB-and-lower, and then xor them to create
1809   // the mask of that's all ones on [msb, lsb].  Finally we not it to
1810   // create the final mask.
1811   unsigned msb = fieldFromInstruction(Val, 5, 5);
1812   unsigned lsb = fieldFromInstruction(Val, 0, 5);
1813 
1814   DecodeStatus S = MCDisassembler::Success;
1815   if (lsb > msb) {
1816     Check(S, MCDisassembler::SoftFail);
1817     // The check above will cause the warning for the "potentially undefined
1818     // instruction encoding" but we can't build a bad MCOperand value here
1819     // with a lsb > msb or else printing the MCInst will cause a crash.
1820     lsb = msb;
1821   }
1822 
1823   uint32_t msb_mask = 0xFFFFFFFF;
1824   if (msb != 31) msb_mask = (1U << (msb+1)) - 1;
1825   uint32_t lsb_mask = (1U << lsb) - 1;
1826 
1827   Inst.addOperand(MCOperand::createImm(~(msb_mask ^ lsb_mask)));
1828   return S;
1829 }
1830 
1831 static DecodeStatus DecodeCopMemInstruction(MCInst &Inst, unsigned Insn,
1832                                             uint64_t Address,
1833                                             const MCDisassembler *Decoder) {
1834   DecodeStatus S = MCDisassembler::Success;
1835 
1836   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1837   unsigned CRd = fieldFromInstruction(Insn, 12, 4);
1838   unsigned coproc = fieldFromInstruction(Insn, 8, 4);
1839   unsigned imm = fieldFromInstruction(Insn, 0, 8);
1840   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1841   unsigned U = fieldFromInstruction(Insn, 23, 1);
1842   const FeatureBitset &featureBits =
1843     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1844 
1845   switch (Inst.getOpcode()) {
1846     case ARM::LDC_OFFSET:
1847     case ARM::LDC_PRE:
1848     case ARM::LDC_POST:
1849     case ARM::LDC_OPTION:
1850     case ARM::LDCL_OFFSET:
1851     case ARM::LDCL_PRE:
1852     case ARM::LDCL_POST:
1853     case ARM::LDCL_OPTION:
1854     case ARM::STC_OFFSET:
1855     case ARM::STC_PRE:
1856     case ARM::STC_POST:
1857     case ARM::STC_OPTION:
1858     case ARM::STCL_OFFSET:
1859     case ARM::STCL_PRE:
1860     case ARM::STCL_POST:
1861     case ARM::STCL_OPTION:
1862     case ARM::t2LDC_OFFSET:
1863     case ARM::t2LDC_PRE:
1864     case ARM::t2LDC_POST:
1865     case ARM::t2LDC_OPTION:
1866     case ARM::t2LDCL_OFFSET:
1867     case ARM::t2LDCL_PRE:
1868     case ARM::t2LDCL_POST:
1869     case ARM::t2LDCL_OPTION:
1870     case ARM::t2STC_OFFSET:
1871     case ARM::t2STC_PRE:
1872     case ARM::t2STC_POST:
1873     case ARM::t2STC_OPTION:
1874     case ARM::t2STCL_OFFSET:
1875     case ARM::t2STCL_PRE:
1876     case ARM::t2STCL_POST:
1877     case ARM::t2STCL_OPTION:
1878     case ARM::t2LDC2_OFFSET:
1879     case ARM::t2LDC2L_OFFSET:
1880     case ARM::t2LDC2_PRE:
1881     case ARM::t2LDC2L_PRE:
1882     case ARM::t2STC2_OFFSET:
1883     case ARM::t2STC2L_OFFSET:
1884     case ARM::t2STC2_PRE:
1885     case ARM::t2STC2L_PRE:
1886     case ARM::LDC2_OFFSET:
1887     case ARM::LDC2L_OFFSET:
1888     case ARM::LDC2_PRE:
1889     case ARM::LDC2L_PRE:
1890     case ARM::STC2_OFFSET:
1891     case ARM::STC2L_OFFSET:
1892     case ARM::STC2_PRE:
1893     case ARM::STC2L_PRE:
1894     case ARM::t2LDC2_OPTION:
1895     case ARM::t2STC2_OPTION:
1896     case ARM::t2LDC2_POST:
1897     case ARM::t2LDC2L_POST:
1898     case ARM::t2STC2_POST:
1899     case ARM::t2STC2L_POST:
1900     case ARM::LDC2_POST:
1901     case ARM::LDC2L_POST:
1902     case ARM::STC2_POST:
1903     case ARM::STC2L_POST:
1904       if (coproc == 0xA || coproc == 0xB ||
1905           (featureBits[ARM::HasV8_1MMainlineOps] &&
1906            (coproc == 0x8 || coproc == 0x9 || coproc == 0xA || coproc == 0xB ||
1907             coproc == 0xE || coproc == 0xF)))
1908         return MCDisassembler::Fail;
1909       break;
1910     default:
1911       break;
1912   }
1913 
1914   if (featureBits[ARM::HasV8Ops] && (coproc != 14))
1915     return MCDisassembler::Fail;
1916 
1917   Inst.addOperand(MCOperand::createImm(coproc));
1918   Inst.addOperand(MCOperand::createImm(CRd));
1919   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1920     return MCDisassembler::Fail;
1921 
1922   switch (Inst.getOpcode()) {
1923     case ARM::t2LDC2_OFFSET:
1924     case ARM::t2LDC2L_OFFSET:
1925     case ARM::t2LDC2_PRE:
1926     case ARM::t2LDC2L_PRE:
1927     case ARM::t2STC2_OFFSET:
1928     case ARM::t2STC2L_OFFSET:
1929     case ARM::t2STC2_PRE:
1930     case ARM::t2STC2L_PRE:
1931     case ARM::LDC2_OFFSET:
1932     case ARM::LDC2L_OFFSET:
1933     case ARM::LDC2_PRE:
1934     case ARM::LDC2L_PRE:
1935     case ARM::STC2_OFFSET:
1936     case ARM::STC2L_OFFSET:
1937     case ARM::STC2_PRE:
1938     case ARM::STC2L_PRE:
1939     case ARM::t2LDC_OFFSET:
1940     case ARM::t2LDCL_OFFSET:
1941     case ARM::t2LDC_PRE:
1942     case ARM::t2LDCL_PRE:
1943     case ARM::t2STC_OFFSET:
1944     case ARM::t2STCL_OFFSET:
1945     case ARM::t2STC_PRE:
1946     case ARM::t2STCL_PRE:
1947     case ARM::LDC_OFFSET:
1948     case ARM::LDCL_OFFSET:
1949     case ARM::LDC_PRE:
1950     case ARM::LDCL_PRE:
1951     case ARM::STC_OFFSET:
1952     case ARM::STCL_OFFSET:
1953     case ARM::STC_PRE:
1954     case ARM::STCL_PRE:
1955       imm = ARM_AM::getAM5Opc(U ? ARM_AM::add : ARM_AM::sub, imm);
1956       Inst.addOperand(MCOperand::createImm(imm));
1957       break;
1958     case ARM::t2LDC2_POST:
1959     case ARM::t2LDC2L_POST:
1960     case ARM::t2STC2_POST:
1961     case ARM::t2STC2L_POST:
1962     case ARM::LDC2_POST:
1963     case ARM::LDC2L_POST:
1964     case ARM::STC2_POST:
1965     case ARM::STC2L_POST:
1966     case ARM::t2LDC_POST:
1967     case ARM::t2LDCL_POST:
1968     case ARM::t2STC_POST:
1969     case ARM::t2STCL_POST:
1970     case ARM::LDC_POST:
1971     case ARM::LDCL_POST:
1972     case ARM::STC_POST:
1973     case ARM::STCL_POST:
1974       imm |= U << 8;
1975       LLVM_FALLTHROUGH;
1976     default:
1977       // The 'option' variant doesn't encode 'U' in the immediate since
1978       // the immediate is unsigned [0,255].
1979       Inst.addOperand(MCOperand::createImm(imm));
1980       break;
1981   }
1982 
1983   switch (Inst.getOpcode()) {
1984     case ARM::LDC_OFFSET:
1985     case ARM::LDC_PRE:
1986     case ARM::LDC_POST:
1987     case ARM::LDC_OPTION:
1988     case ARM::LDCL_OFFSET:
1989     case ARM::LDCL_PRE:
1990     case ARM::LDCL_POST:
1991     case ARM::LDCL_OPTION:
1992     case ARM::STC_OFFSET:
1993     case ARM::STC_PRE:
1994     case ARM::STC_POST:
1995     case ARM::STC_OPTION:
1996     case ARM::STCL_OFFSET:
1997     case ARM::STCL_PRE:
1998     case ARM::STCL_POST:
1999     case ARM::STCL_OPTION:
2000       if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2001         return MCDisassembler::Fail;
2002       break;
2003     default:
2004       break;
2005   }
2006 
2007   return S;
2008 }
2009 
2010 static DecodeStatus
2011 DecodeAddrMode2IdxInstruction(MCInst &Inst, unsigned Insn, uint64_t Address,
2012                               const MCDisassembler *Decoder) {
2013   DecodeStatus S = MCDisassembler::Success;
2014 
2015   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2016   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
2017   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2018   unsigned imm = fieldFromInstruction(Insn, 0, 12);
2019   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2020   unsigned reg = fieldFromInstruction(Insn, 25, 1);
2021   unsigned P = fieldFromInstruction(Insn, 24, 1);
2022   unsigned W = fieldFromInstruction(Insn, 21, 1);
2023 
2024   // On stores, the writeback operand precedes Rt.
2025   switch (Inst.getOpcode()) {
2026     case ARM::STR_POST_IMM:
2027     case ARM::STR_POST_REG:
2028     case ARM::STRB_POST_IMM:
2029     case ARM::STRB_POST_REG:
2030     case ARM::STRT_POST_REG:
2031     case ARM::STRT_POST_IMM:
2032     case ARM::STRBT_POST_REG:
2033     case ARM::STRBT_POST_IMM:
2034       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2035         return MCDisassembler::Fail;
2036       break;
2037     default:
2038       break;
2039   }
2040 
2041   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
2042     return MCDisassembler::Fail;
2043 
2044   // On loads, the writeback operand comes after Rt.
2045   switch (Inst.getOpcode()) {
2046     case ARM::LDR_POST_IMM:
2047     case ARM::LDR_POST_REG:
2048     case ARM::LDRB_POST_IMM:
2049     case ARM::LDRB_POST_REG:
2050     case ARM::LDRBT_POST_REG:
2051     case ARM::LDRBT_POST_IMM:
2052     case ARM::LDRT_POST_REG:
2053     case ARM::LDRT_POST_IMM:
2054       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2055         return MCDisassembler::Fail;
2056       break;
2057     default:
2058       break;
2059   }
2060 
2061   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2062     return MCDisassembler::Fail;
2063 
2064   ARM_AM::AddrOpc Op = ARM_AM::add;
2065   if (!fieldFromInstruction(Insn, 23, 1))
2066     Op = ARM_AM::sub;
2067 
2068   bool writeback = (P == 0) || (W == 1);
2069   unsigned idx_mode = 0;
2070   if (P && writeback)
2071     idx_mode = ARMII::IndexModePre;
2072   else if (!P && writeback)
2073     idx_mode = ARMII::IndexModePost;
2074 
2075   if (writeback && (Rn == 15 || Rn == Rt))
2076     S = MCDisassembler::SoftFail; // UNPREDICTABLE
2077 
2078   if (reg) {
2079     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
2080       return MCDisassembler::Fail;
2081     ARM_AM::ShiftOpc Opc = ARM_AM::lsl;
2082     switch( fieldFromInstruction(Insn, 5, 2)) {
2083       case 0:
2084         Opc = ARM_AM::lsl;
2085         break;
2086       case 1:
2087         Opc = ARM_AM::lsr;
2088         break;
2089       case 2:
2090         Opc = ARM_AM::asr;
2091         break;
2092       case 3:
2093         Opc = ARM_AM::ror;
2094         break;
2095       default:
2096         return MCDisassembler::Fail;
2097     }
2098     unsigned amt = fieldFromInstruction(Insn, 7, 5);
2099     if (Opc == ARM_AM::ror && amt == 0)
2100       Opc = ARM_AM::rrx;
2101     unsigned imm = ARM_AM::getAM2Opc(Op, amt, Opc, idx_mode);
2102 
2103     Inst.addOperand(MCOperand::createImm(imm));
2104   } else {
2105     Inst.addOperand(MCOperand::createReg(0));
2106     unsigned tmp = ARM_AM::getAM2Opc(Op, imm, ARM_AM::lsl, idx_mode);
2107     Inst.addOperand(MCOperand::createImm(tmp));
2108   }
2109 
2110   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2111     return MCDisassembler::Fail;
2112 
2113   return S;
2114 }
2115 
2116 static DecodeStatus DecodeSORegMemOperand(MCInst &Inst, unsigned Val,
2117                                           uint64_t Address,
2118                                           const MCDisassembler *Decoder) {
2119   DecodeStatus S = MCDisassembler::Success;
2120 
2121   unsigned Rn = fieldFromInstruction(Val, 13, 4);
2122   unsigned Rm = fieldFromInstruction(Val,  0, 4);
2123   unsigned type = fieldFromInstruction(Val, 5, 2);
2124   unsigned imm = fieldFromInstruction(Val, 7, 5);
2125   unsigned U = fieldFromInstruction(Val, 12, 1);
2126 
2127   ARM_AM::ShiftOpc ShOp = ARM_AM::lsl;
2128   switch (type) {
2129     case 0:
2130       ShOp = ARM_AM::lsl;
2131       break;
2132     case 1:
2133       ShOp = ARM_AM::lsr;
2134       break;
2135     case 2:
2136       ShOp = ARM_AM::asr;
2137       break;
2138     case 3:
2139       ShOp = ARM_AM::ror;
2140       break;
2141   }
2142 
2143   if (ShOp == ARM_AM::ror && imm == 0)
2144     ShOp = ARM_AM::rrx;
2145 
2146   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2147     return MCDisassembler::Fail;
2148   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2149     return MCDisassembler::Fail;
2150   unsigned shift;
2151   if (U)
2152     shift = ARM_AM::getAM2Opc(ARM_AM::add, imm, ShOp);
2153   else
2154     shift = ARM_AM::getAM2Opc(ARM_AM::sub, imm, ShOp);
2155   Inst.addOperand(MCOperand::createImm(shift));
2156 
2157   return S;
2158 }
2159 
2160 static DecodeStatus DecodeTSBInstruction(MCInst &Inst, unsigned Insn,
2161                                          uint64_t Address,
2162                                          const MCDisassembler *Decoder) {
2163   if (Inst.getOpcode() != ARM::TSB && Inst.getOpcode() != ARM::t2TSB)
2164     return MCDisassembler::Fail;
2165 
2166   // The "csync" operand is not encoded into the "tsb" instruction (as this is
2167   // the only available operand), but LLVM expects the instruction to have one
2168   // operand, so we need to add the csync when decoding.
2169   Inst.addOperand(MCOperand::createImm(ARM_TSB::CSYNC));
2170   return MCDisassembler::Success;
2171 }
2172 
2173 static DecodeStatus DecodeAddrMode3Instruction(MCInst &Inst, unsigned Insn,
2174                                                uint64_t Address,
2175                                                const MCDisassembler *Decoder) {
2176   DecodeStatus S = MCDisassembler::Success;
2177 
2178   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
2179   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2180   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2181   unsigned type = fieldFromInstruction(Insn, 22, 1);
2182   unsigned imm = fieldFromInstruction(Insn, 8, 4);
2183   unsigned U = ((~fieldFromInstruction(Insn, 23, 1)) & 1) << 8;
2184   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2185   unsigned W = fieldFromInstruction(Insn, 21, 1);
2186   unsigned P = fieldFromInstruction(Insn, 24, 1);
2187   unsigned Rt2 = Rt + 1;
2188 
2189   bool writeback = (W == 1) | (P == 0);
2190 
2191   // For {LD,ST}RD, Rt must be even, else undefined.
2192   switch (Inst.getOpcode()) {
2193     case ARM::STRD:
2194     case ARM::STRD_PRE:
2195     case ARM::STRD_POST:
2196     case ARM::LDRD:
2197     case ARM::LDRD_PRE:
2198     case ARM::LDRD_POST:
2199       if (Rt & 0x1) S = MCDisassembler::SoftFail;
2200       break;
2201     default:
2202       break;
2203   }
2204   switch (Inst.getOpcode()) {
2205     case ARM::STRD:
2206     case ARM::STRD_PRE:
2207     case ARM::STRD_POST:
2208       if (P == 0 && W == 1)
2209         S = MCDisassembler::SoftFail;
2210 
2211       if (writeback && (Rn == 15 || Rn == Rt || Rn == Rt2))
2212         S = MCDisassembler::SoftFail;
2213       if (type && Rm == 15)
2214         S = MCDisassembler::SoftFail;
2215       if (Rt2 == 15)
2216         S = MCDisassembler::SoftFail;
2217       if (!type && fieldFromInstruction(Insn, 8, 4))
2218         S = MCDisassembler::SoftFail;
2219       break;
2220     case ARM::STRH:
2221     case ARM::STRH_PRE:
2222     case ARM::STRH_POST:
2223       if (Rt == 15)
2224         S = MCDisassembler::SoftFail;
2225       if (writeback && (Rn == 15 || Rn == Rt))
2226         S = MCDisassembler::SoftFail;
2227       if (!type && Rm == 15)
2228         S = MCDisassembler::SoftFail;
2229       break;
2230     case ARM::LDRD:
2231     case ARM::LDRD_PRE:
2232     case ARM::LDRD_POST:
2233       if (type && Rn == 15) {
2234         if (Rt2 == 15)
2235           S = MCDisassembler::SoftFail;
2236         break;
2237       }
2238       if (P == 0 && W == 1)
2239         S = MCDisassembler::SoftFail;
2240       if (!type && (Rt2 == 15 || Rm == 15 || Rm == Rt || Rm == Rt2))
2241         S = MCDisassembler::SoftFail;
2242       if (!type && writeback && Rn == 15)
2243         S = MCDisassembler::SoftFail;
2244       if (writeback && (Rn == Rt || Rn == Rt2))
2245         S = MCDisassembler::SoftFail;
2246       break;
2247     case ARM::LDRH:
2248     case ARM::LDRH_PRE:
2249     case ARM::LDRH_POST:
2250       if (type && Rn == 15) {
2251         if (Rt == 15)
2252           S = MCDisassembler::SoftFail;
2253         break;
2254       }
2255       if (Rt == 15)
2256         S = MCDisassembler::SoftFail;
2257       if (!type && Rm == 15)
2258         S = MCDisassembler::SoftFail;
2259       if (!type && writeback && (Rn == 15 || Rn == Rt))
2260         S = MCDisassembler::SoftFail;
2261       break;
2262     case ARM::LDRSH:
2263     case ARM::LDRSH_PRE:
2264     case ARM::LDRSH_POST:
2265     case ARM::LDRSB:
2266     case ARM::LDRSB_PRE:
2267     case ARM::LDRSB_POST:
2268       if (type && Rn == 15) {
2269         if (Rt == 15)
2270           S = MCDisassembler::SoftFail;
2271         break;
2272       }
2273       if (type && (Rt == 15 || (writeback && Rn == Rt)))
2274         S = MCDisassembler::SoftFail;
2275       if (!type && (Rt == 15 || Rm == 15))
2276         S = MCDisassembler::SoftFail;
2277       if (!type && writeback && (Rn == 15 || Rn == Rt))
2278         S = MCDisassembler::SoftFail;
2279       break;
2280     default:
2281       break;
2282   }
2283 
2284   if (writeback) { // Writeback
2285     if (P)
2286       U |= ARMII::IndexModePre << 9;
2287     else
2288       U |= ARMII::IndexModePost << 9;
2289 
2290     // On stores, the writeback operand precedes Rt.
2291     switch (Inst.getOpcode()) {
2292     case ARM::STRD:
2293     case ARM::STRD_PRE:
2294     case ARM::STRD_POST:
2295     case ARM::STRH:
2296     case ARM::STRH_PRE:
2297     case ARM::STRH_POST:
2298       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2299         return MCDisassembler::Fail;
2300       break;
2301     default:
2302       break;
2303     }
2304   }
2305 
2306   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
2307     return MCDisassembler::Fail;
2308   switch (Inst.getOpcode()) {
2309     case ARM::STRD:
2310     case ARM::STRD_PRE:
2311     case ARM::STRD_POST:
2312     case ARM::LDRD:
2313     case ARM::LDRD_PRE:
2314     case ARM::LDRD_POST:
2315       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder)))
2316         return MCDisassembler::Fail;
2317       break;
2318     default:
2319       break;
2320   }
2321 
2322   if (writeback) {
2323     // On loads, the writeback operand comes after Rt.
2324     switch (Inst.getOpcode()) {
2325     case ARM::LDRD:
2326     case ARM::LDRD_PRE:
2327     case ARM::LDRD_POST:
2328     case ARM::LDRH:
2329     case ARM::LDRH_PRE:
2330     case ARM::LDRH_POST:
2331     case ARM::LDRSH:
2332     case ARM::LDRSH_PRE:
2333     case ARM::LDRSH_POST:
2334     case ARM::LDRSB:
2335     case ARM::LDRSB_PRE:
2336     case ARM::LDRSB_POST:
2337     case ARM::LDRHTr:
2338     case ARM::LDRSBTr:
2339       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2340         return MCDisassembler::Fail;
2341       break;
2342     default:
2343       break;
2344     }
2345   }
2346 
2347   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2348     return MCDisassembler::Fail;
2349 
2350   if (type) {
2351     Inst.addOperand(MCOperand::createReg(0));
2352     Inst.addOperand(MCOperand::createImm(U | (imm << 4) | Rm));
2353   } else {
2354     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2355     return MCDisassembler::Fail;
2356     Inst.addOperand(MCOperand::createImm(U));
2357   }
2358 
2359   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2360     return MCDisassembler::Fail;
2361 
2362   return S;
2363 }
2364 
2365 static DecodeStatus DecodeRFEInstruction(MCInst &Inst, unsigned Insn,
2366                                          uint64_t Address,
2367                                          const MCDisassembler *Decoder) {
2368   DecodeStatus S = MCDisassembler::Success;
2369 
2370   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2371   unsigned mode = fieldFromInstruction(Insn, 23, 2);
2372 
2373   switch (mode) {
2374     case 0:
2375       mode = ARM_AM::da;
2376       break;
2377     case 1:
2378       mode = ARM_AM::ia;
2379       break;
2380     case 2:
2381       mode = ARM_AM::db;
2382       break;
2383     case 3:
2384       mode = ARM_AM::ib;
2385       break;
2386   }
2387 
2388   Inst.addOperand(MCOperand::createImm(mode));
2389   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2390     return MCDisassembler::Fail;
2391 
2392   return S;
2393 }
2394 
2395 static DecodeStatus DecodeQADDInstruction(MCInst &Inst, unsigned Insn,
2396                                           uint64_t Address,
2397                                           const MCDisassembler *Decoder) {
2398   DecodeStatus S = MCDisassembler::Success;
2399 
2400   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2401   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2402   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2403   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2404 
2405   if (pred == 0xF)
2406     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
2407 
2408   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2409     return MCDisassembler::Fail;
2410   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
2411     return MCDisassembler::Fail;
2412   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
2413     return MCDisassembler::Fail;
2414   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2415     return MCDisassembler::Fail;
2416   return S;
2417 }
2418 
2419 static DecodeStatus
2420 DecodeMemMultipleWritebackInstruction(MCInst &Inst, unsigned Insn,
2421                                       uint64_t Address,
2422                                       const MCDisassembler *Decoder) {
2423   DecodeStatus S = MCDisassembler::Success;
2424 
2425   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2426   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2427   unsigned reglist = fieldFromInstruction(Insn, 0, 16);
2428 
2429   if (pred == 0xF) {
2430     // Ambiguous with RFE and SRS
2431     switch (Inst.getOpcode()) {
2432       case ARM::LDMDA:
2433         Inst.setOpcode(ARM::RFEDA);
2434         break;
2435       case ARM::LDMDA_UPD:
2436         Inst.setOpcode(ARM::RFEDA_UPD);
2437         break;
2438       case ARM::LDMDB:
2439         Inst.setOpcode(ARM::RFEDB);
2440         break;
2441       case ARM::LDMDB_UPD:
2442         Inst.setOpcode(ARM::RFEDB_UPD);
2443         break;
2444       case ARM::LDMIA:
2445         Inst.setOpcode(ARM::RFEIA);
2446         break;
2447       case ARM::LDMIA_UPD:
2448         Inst.setOpcode(ARM::RFEIA_UPD);
2449         break;
2450       case ARM::LDMIB:
2451         Inst.setOpcode(ARM::RFEIB);
2452         break;
2453       case ARM::LDMIB_UPD:
2454         Inst.setOpcode(ARM::RFEIB_UPD);
2455         break;
2456       case ARM::STMDA:
2457         Inst.setOpcode(ARM::SRSDA);
2458         break;
2459       case ARM::STMDA_UPD:
2460         Inst.setOpcode(ARM::SRSDA_UPD);
2461         break;
2462       case ARM::STMDB:
2463         Inst.setOpcode(ARM::SRSDB);
2464         break;
2465       case ARM::STMDB_UPD:
2466         Inst.setOpcode(ARM::SRSDB_UPD);
2467         break;
2468       case ARM::STMIA:
2469         Inst.setOpcode(ARM::SRSIA);
2470         break;
2471       case ARM::STMIA_UPD:
2472         Inst.setOpcode(ARM::SRSIA_UPD);
2473         break;
2474       case ARM::STMIB:
2475         Inst.setOpcode(ARM::SRSIB);
2476         break;
2477       case ARM::STMIB_UPD:
2478         Inst.setOpcode(ARM::SRSIB_UPD);
2479         break;
2480       default:
2481         return MCDisassembler::Fail;
2482     }
2483 
2484     // For stores (which become SRS's, the only operand is the mode.
2485     if (fieldFromInstruction(Insn, 20, 1) == 0) {
2486       // Check SRS encoding constraints
2487       if (!(fieldFromInstruction(Insn, 22, 1) == 1 &&
2488             fieldFromInstruction(Insn, 20, 1) == 0))
2489         return MCDisassembler::Fail;
2490 
2491       Inst.addOperand(
2492           MCOperand::createImm(fieldFromInstruction(Insn, 0, 4)));
2493       return S;
2494     }
2495 
2496     return DecodeRFEInstruction(Inst, Insn, Address, Decoder);
2497   }
2498 
2499   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2500     return MCDisassembler::Fail;
2501   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2502     return MCDisassembler::Fail; // Tied
2503   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2504     return MCDisassembler::Fail;
2505   if (!Check(S, DecodeRegListOperand(Inst, reglist, Address, Decoder)))
2506     return MCDisassembler::Fail;
2507 
2508   return S;
2509 }
2510 
2511 // Check for UNPREDICTABLE predicated ESB instruction
2512 static DecodeStatus DecodeHINTInstruction(MCInst &Inst, unsigned Insn,
2513                                           uint64_t Address,
2514                                           const MCDisassembler *Decoder) {
2515   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2516   unsigned imm8 = fieldFromInstruction(Insn, 0, 8);
2517   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
2518   const FeatureBitset &FeatureBits = Dis->getSubtargetInfo().getFeatureBits();
2519 
2520   DecodeStatus S = MCDisassembler::Success;
2521 
2522   Inst.addOperand(MCOperand::createImm(imm8));
2523 
2524   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2525     return MCDisassembler::Fail;
2526 
2527   // ESB is unpredictable if pred != AL. Without the RAS extension, it is a NOP,
2528   // so all predicates should be allowed.
2529   if (imm8 == 0x10 && pred != 0xe && ((FeatureBits[ARM::FeatureRAS]) != 0))
2530     S = MCDisassembler::SoftFail;
2531 
2532   return S;
2533 }
2534 
2535 static DecodeStatus DecodeCPSInstruction(MCInst &Inst, unsigned Insn,
2536                                          uint64_t Address,
2537                                          const MCDisassembler *Decoder) {
2538   unsigned imod = fieldFromInstruction(Insn, 18, 2);
2539   unsigned M = fieldFromInstruction(Insn, 17, 1);
2540   unsigned iflags = fieldFromInstruction(Insn, 6, 3);
2541   unsigned mode = fieldFromInstruction(Insn, 0, 5);
2542 
2543   DecodeStatus S = MCDisassembler::Success;
2544 
2545   // This decoder is called from multiple location that do not check
2546   // the full encoding is valid before they do.
2547   if (fieldFromInstruction(Insn, 5, 1) != 0 ||
2548       fieldFromInstruction(Insn, 16, 1) != 0 ||
2549       fieldFromInstruction(Insn, 20, 8) != 0x10)
2550     return MCDisassembler::Fail;
2551 
2552   // imod == '01' --> UNPREDICTABLE
2553   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
2554   // return failure here.  The '01' imod value is unprintable, so there's
2555   // nothing useful we could do even if we returned UNPREDICTABLE.
2556 
2557   if (imod == 1) return MCDisassembler::Fail;
2558 
2559   if (imod && M) {
2560     Inst.setOpcode(ARM::CPS3p);
2561     Inst.addOperand(MCOperand::createImm(imod));
2562     Inst.addOperand(MCOperand::createImm(iflags));
2563     Inst.addOperand(MCOperand::createImm(mode));
2564   } else if (imod && !M) {
2565     Inst.setOpcode(ARM::CPS2p);
2566     Inst.addOperand(MCOperand::createImm(imod));
2567     Inst.addOperand(MCOperand::createImm(iflags));
2568     if (mode) S = MCDisassembler::SoftFail;
2569   } else if (!imod && M) {
2570     Inst.setOpcode(ARM::CPS1p);
2571     Inst.addOperand(MCOperand::createImm(mode));
2572     if (iflags) S = MCDisassembler::SoftFail;
2573   } else {
2574     // imod == '00' && M == '0' --> UNPREDICTABLE
2575     Inst.setOpcode(ARM::CPS1p);
2576     Inst.addOperand(MCOperand::createImm(mode));
2577     S = MCDisassembler::SoftFail;
2578   }
2579 
2580   return S;
2581 }
2582 
2583 static DecodeStatus DecodeT2CPSInstruction(MCInst &Inst, unsigned Insn,
2584                                            uint64_t Address,
2585                                            const MCDisassembler *Decoder) {
2586   unsigned imod = fieldFromInstruction(Insn, 9, 2);
2587   unsigned M = fieldFromInstruction(Insn, 8, 1);
2588   unsigned iflags = fieldFromInstruction(Insn, 5, 3);
2589   unsigned mode = fieldFromInstruction(Insn, 0, 5);
2590 
2591   DecodeStatus S = MCDisassembler::Success;
2592 
2593   // imod == '01' --> UNPREDICTABLE
2594   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
2595   // return failure here.  The '01' imod value is unprintable, so there's
2596   // nothing useful we could do even if we returned UNPREDICTABLE.
2597 
2598   if (imod == 1) return MCDisassembler::Fail;
2599 
2600   if (imod && M) {
2601     Inst.setOpcode(ARM::t2CPS3p);
2602     Inst.addOperand(MCOperand::createImm(imod));
2603     Inst.addOperand(MCOperand::createImm(iflags));
2604     Inst.addOperand(MCOperand::createImm(mode));
2605   } else if (imod && !M) {
2606     Inst.setOpcode(ARM::t2CPS2p);
2607     Inst.addOperand(MCOperand::createImm(imod));
2608     Inst.addOperand(MCOperand::createImm(iflags));
2609     if (mode) S = MCDisassembler::SoftFail;
2610   } else if (!imod && M) {
2611     Inst.setOpcode(ARM::t2CPS1p);
2612     Inst.addOperand(MCOperand::createImm(mode));
2613     if (iflags) S = MCDisassembler::SoftFail;
2614   } else {
2615     // imod == '00' && M == '0' --> this is a HINT instruction
2616     int imm = fieldFromInstruction(Insn, 0, 8);
2617     // HINT are defined only for immediate in [0..4]
2618     if(imm > 4) return MCDisassembler::Fail;
2619     Inst.setOpcode(ARM::t2HINT);
2620     Inst.addOperand(MCOperand::createImm(imm));
2621   }
2622 
2623   return S;
2624 }
2625 
2626 static DecodeStatus
2627 DecodeT2HintSpaceInstruction(MCInst &Inst, unsigned Insn, uint64_t Address,
2628                              const MCDisassembler *Decoder) {
2629   unsigned imm = fieldFromInstruction(Insn, 0, 8);
2630 
2631   unsigned Opcode = ARM::t2HINT;
2632 
2633   if (imm == 0x0D) {
2634     Opcode = ARM::t2PACBTI;
2635   } else if (imm == 0x1D) {
2636     Opcode = ARM::t2PAC;
2637   } else if (imm == 0x2D) {
2638     Opcode = ARM::t2AUT;
2639   } else if (imm == 0x0F) {
2640     Opcode = ARM::t2BTI;
2641   }
2642 
2643   Inst.setOpcode(Opcode);
2644   if (Opcode == ARM::t2HINT) {
2645     Inst.addOperand(MCOperand::createImm(imm));
2646   }
2647 
2648   return MCDisassembler::Success;
2649 }
2650 
2651 static DecodeStatus DecodeT2MOVTWInstruction(MCInst &Inst, unsigned Insn,
2652                                              uint64_t Address,
2653                                              const MCDisassembler *Decoder) {
2654   DecodeStatus S = MCDisassembler::Success;
2655 
2656   unsigned Rd = fieldFromInstruction(Insn, 8, 4);
2657   unsigned imm = 0;
2658 
2659   imm |= (fieldFromInstruction(Insn, 0, 8) << 0);
2660   imm |= (fieldFromInstruction(Insn, 12, 3) << 8);
2661   imm |= (fieldFromInstruction(Insn, 16, 4) << 12);
2662   imm |= (fieldFromInstruction(Insn, 26, 1) << 11);
2663 
2664   if (Inst.getOpcode() == ARM::t2MOVTi16)
2665     if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
2666       return MCDisassembler::Fail;
2667   if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
2668     return MCDisassembler::Fail;
2669 
2670   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
2671     Inst.addOperand(MCOperand::createImm(imm));
2672 
2673   return S;
2674 }
2675 
2676 static DecodeStatus DecodeArmMOVTWInstruction(MCInst &Inst, unsigned Insn,
2677                                               uint64_t Address,
2678                                               const MCDisassembler *Decoder) {
2679   DecodeStatus S = MCDisassembler::Success;
2680 
2681   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2682   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2683   unsigned imm = 0;
2684 
2685   imm |= (fieldFromInstruction(Insn, 0, 12) << 0);
2686   imm |= (fieldFromInstruction(Insn, 16, 4) << 12);
2687 
2688   if (Inst.getOpcode() == ARM::MOVTi16)
2689     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2690       return MCDisassembler::Fail;
2691 
2692   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2693     return MCDisassembler::Fail;
2694 
2695   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
2696     Inst.addOperand(MCOperand::createImm(imm));
2697 
2698   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2699     return MCDisassembler::Fail;
2700 
2701   return S;
2702 }
2703 
2704 static DecodeStatus DecodeSMLAInstruction(MCInst &Inst, unsigned Insn,
2705                                           uint64_t Address,
2706                                           const MCDisassembler *Decoder) {
2707   DecodeStatus S = MCDisassembler::Success;
2708 
2709   unsigned Rd = fieldFromInstruction(Insn, 16, 4);
2710   unsigned Rn = fieldFromInstruction(Insn, 0, 4);
2711   unsigned Rm = fieldFromInstruction(Insn, 8, 4);
2712   unsigned Ra = fieldFromInstruction(Insn, 12, 4);
2713   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2714 
2715   if (pred == 0xF)
2716     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
2717 
2718   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2719     return MCDisassembler::Fail;
2720   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
2721     return MCDisassembler::Fail;
2722   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
2723     return MCDisassembler::Fail;
2724   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Ra, Address, Decoder)))
2725     return MCDisassembler::Fail;
2726 
2727   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2728     return MCDisassembler::Fail;
2729 
2730   return S;
2731 }
2732 
2733 static DecodeStatus DecodeTSTInstruction(MCInst &Inst, unsigned Insn,
2734                                          uint64_t Address,
2735                                          const MCDisassembler *Decoder) {
2736   DecodeStatus S = MCDisassembler::Success;
2737 
2738   unsigned Pred = fieldFromInstruction(Insn, 28, 4);
2739   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2740   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2741 
2742   if (Pred == 0xF)
2743     return DecodeSETPANInstruction(Inst, Insn, Address, Decoder);
2744 
2745   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2746     return MCDisassembler::Fail;
2747   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2748     return MCDisassembler::Fail;
2749   if (!Check(S, DecodePredicateOperand(Inst, Pred, Address, Decoder)))
2750     return MCDisassembler::Fail;
2751 
2752   return S;
2753 }
2754 
2755 static DecodeStatus DecodeSETPANInstruction(MCInst &Inst, unsigned Insn,
2756                                             uint64_t Address,
2757                                             const MCDisassembler *Decoder) {
2758   DecodeStatus S = MCDisassembler::Success;
2759 
2760   unsigned Imm = fieldFromInstruction(Insn, 9, 1);
2761 
2762   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
2763   const FeatureBitset &FeatureBits = Dis->getSubtargetInfo().getFeatureBits();
2764 
2765   if (!FeatureBits[ARM::HasV8_1aOps] ||
2766       !FeatureBits[ARM::HasV8Ops])
2767     return MCDisassembler::Fail;
2768 
2769   // Decoder can be called from DecodeTST, which does not check the full
2770   // encoding is valid.
2771   if (fieldFromInstruction(Insn, 20,12) != 0xf11 ||
2772       fieldFromInstruction(Insn, 4,4) != 0)
2773     return MCDisassembler::Fail;
2774   if (fieldFromInstruction(Insn, 10,10) != 0 ||
2775       fieldFromInstruction(Insn, 0,4) != 0)
2776     S = MCDisassembler::SoftFail;
2777 
2778   Inst.setOpcode(ARM::SETPAN);
2779   Inst.addOperand(MCOperand::createImm(Imm));
2780 
2781   return S;
2782 }
2783 
2784 static DecodeStatus DecodeAddrModeImm12Operand(MCInst &Inst, unsigned Val,
2785                                                uint64_t Address,
2786                                                const MCDisassembler *Decoder) {
2787   DecodeStatus S = MCDisassembler::Success;
2788 
2789   unsigned add = fieldFromInstruction(Val, 12, 1);
2790   unsigned imm = fieldFromInstruction(Val, 0, 12);
2791   unsigned Rn = fieldFromInstruction(Val, 13, 4);
2792 
2793   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2794     return MCDisassembler::Fail;
2795 
2796   if (!add) imm *= -1;
2797   if (imm == 0 && !add) imm = INT32_MIN;
2798   Inst.addOperand(MCOperand::createImm(imm));
2799   if (Rn == 15)
2800     tryAddingPcLoadReferenceComment(Address, Address + imm + 8, Decoder);
2801 
2802   return S;
2803 }
2804 
2805 static DecodeStatus DecodeAddrMode5Operand(MCInst &Inst, unsigned Val,
2806                                            uint64_t Address,
2807                                            const MCDisassembler *Decoder) {
2808   DecodeStatus S = MCDisassembler::Success;
2809 
2810   unsigned Rn = fieldFromInstruction(Val, 9, 4);
2811   // U == 1 to add imm, 0 to subtract it.
2812   unsigned U = fieldFromInstruction(Val, 8, 1);
2813   unsigned imm = fieldFromInstruction(Val, 0, 8);
2814 
2815   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2816     return MCDisassembler::Fail;
2817 
2818   if (U)
2819     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5Opc(ARM_AM::add, imm)));
2820   else
2821     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5Opc(ARM_AM::sub, imm)));
2822 
2823   return S;
2824 }
2825 
2826 static DecodeStatus DecodeAddrMode5FP16Operand(MCInst &Inst, unsigned Val,
2827                                                uint64_t Address,
2828                                                const MCDisassembler *Decoder) {
2829   DecodeStatus S = MCDisassembler::Success;
2830 
2831   unsigned Rn = fieldFromInstruction(Val, 9, 4);
2832   // U == 1 to add imm, 0 to subtract it.
2833   unsigned U = fieldFromInstruction(Val, 8, 1);
2834   unsigned imm = fieldFromInstruction(Val, 0, 8);
2835 
2836   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2837     return MCDisassembler::Fail;
2838 
2839   if (U)
2840     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5FP16Opc(ARM_AM::add, imm)));
2841   else
2842     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5FP16Opc(ARM_AM::sub, imm)));
2843 
2844   return S;
2845 }
2846 
2847 static DecodeStatus DecodeAddrMode7Operand(MCInst &Inst, unsigned Val,
2848                                            uint64_t Address,
2849                                            const MCDisassembler *Decoder) {
2850   return DecodeGPRRegisterClass(Inst, Val, Address, Decoder);
2851 }
2852 
2853 static DecodeStatus DecodeT2BInstruction(MCInst &Inst, unsigned Insn,
2854                                          uint64_t Address,
2855                                          const MCDisassembler *Decoder) {
2856   DecodeStatus Status = MCDisassembler::Success;
2857 
2858   // Note the J1 and J2 values are from the encoded instruction.  So here
2859   // change them to I1 and I2 values via as documented:
2860   // I1 = NOT(J1 EOR S);
2861   // I2 = NOT(J2 EOR S);
2862   // and build the imm32 with one trailing zero as documented:
2863   // imm32 = SignExtend(S:I1:I2:imm10:imm11:'0', 32);
2864   unsigned S = fieldFromInstruction(Insn, 26, 1);
2865   unsigned J1 = fieldFromInstruction(Insn, 13, 1);
2866   unsigned J2 = fieldFromInstruction(Insn, 11, 1);
2867   unsigned I1 = !(J1 ^ S);
2868   unsigned I2 = !(J2 ^ S);
2869   unsigned imm10 = fieldFromInstruction(Insn, 16, 10);
2870   unsigned imm11 = fieldFromInstruction(Insn, 0, 11);
2871   unsigned tmp = (S << 23) | (I1 << 22) | (I2 << 21) | (imm10 << 11) | imm11;
2872   int imm32 = SignExtend32<25>(tmp << 1);
2873   if (!tryAddingSymbolicOperand(Address, Address + imm32 + 4,
2874                                 true, 4, Inst, Decoder))
2875     Inst.addOperand(MCOperand::createImm(imm32));
2876 
2877   return Status;
2878 }
2879 
2880 static DecodeStatus DecodeBranchImmInstruction(MCInst &Inst, unsigned Insn,
2881                                                uint64_t Address,
2882                                                const MCDisassembler *Decoder) {
2883   DecodeStatus S = MCDisassembler::Success;
2884 
2885   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2886   unsigned imm = fieldFromInstruction(Insn, 0, 24) << 2;
2887 
2888   if (pred == 0xF) {
2889     Inst.setOpcode(ARM::BLXi);
2890     imm |= fieldFromInstruction(Insn, 24, 1) << 1;
2891     if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<26>(imm) + 8,
2892                                   true, 4, Inst, Decoder))
2893     Inst.addOperand(MCOperand::createImm(SignExtend32<26>(imm)));
2894     return S;
2895   }
2896 
2897   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<26>(imm) + 8,
2898                                 true, 4, Inst, Decoder))
2899     Inst.addOperand(MCOperand::createImm(SignExtend32<26>(imm)));
2900 
2901   // We already have BL_pred for BL w/ predicate, no need to add addition
2902   // predicate opreands for BL
2903   if (Inst.getOpcode() != ARM::BL)
2904     if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2905       return MCDisassembler::Fail;
2906 
2907   return S;
2908 }
2909 
2910 static DecodeStatus DecodeAddrMode6Operand(MCInst &Inst, unsigned Val,
2911                                            uint64_t Address,
2912                                            const MCDisassembler *Decoder) {
2913   DecodeStatus S = MCDisassembler::Success;
2914 
2915   unsigned Rm = fieldFromInstruction(Val, 0, 4);
2916   unsigned align = fieldFromInstruction(Val, 4, 2);
2917 
2918   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2919     return MCDisassembler::Fail;
2920   if (!align)
2921     Inst.addOperand(MCOperand::createImm(0));
2922   else
2923     Inst.addOperand(MCOperand::createImm(4 << align));
2924 
2925   return S;
2926 }
2927 
2928 static DecodeStatus DecodeVLDInstruction(MCInst &Inst, unsigned Insn,
2929                                          uint64_t Address,
2930                                          const MCDisassembler *Decoder) {
2931   DecodeStatus S = MCDisassembler::Success;
2932 
2933   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2934   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
2935   unsigned wb = fieldFromInstruction(Insn, 16, 4);
2936   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2937   Rn |= fieldFromInstruction(Insn, 4, 2) << 4;
2938   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2939 
2940   // First output register
2941   switch (Inst.getOpcode()) {
2942   case ARM::VLD1q16: case ARM::VLD1q32: case ARM::VLD1q64: case ARM::VLD1q8:
2943   case ARM::VLD1q16wb_fixed: case ARM::VLD1q16wb_register:
2944   case ARM::VLD1q32wb_fixed: case ARM::VLD1q32wb_register:
2945   case ARM::VLD1q64wb_fixed: case ARM::VLD1q64wb_register:
2946   case ARM::VLD1q8wb_fixed: case ARM::VLD1q8wb_register:
2947   case ARM::VLD2d16: case ARM::VLD2d32: case ARM::VLD2d8:
2948   case ARM::VLD2d16wb_fixed: case ARM::VLD2d16wb_register:
2949   case ARM::VLD2d32wb_fixed: case ARM::VLD2d32wb_register:
2950   case ARM::VLD2d8wb_fixed: case ARM::VLD2d8wb_register:
2951     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
2952       return MCDisassembler::Fail;
2953     break;
2954   case ARM::VLD2b16:
2955   case ARM::VLD2b32:
2956   case ARM::VLD2b8:
2957   case ARM::VLD2b16wb_fixed:
2958   case ARM::VLD2b16wb_register:
2959   case ARM::VLD2b32wb_fixed:
2960   case ARM::VLD2b32wb_register:
2961   case ARM::VLD2b8wb_fixed:
2962   case ARM::VLD2b8wb_register:
2963     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
2964       return MCDisassembler::Fail;
2965     break;
2966   default:
2967     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2968       return MCDisassembler::Fail;
2969   }
2970 
2971   // Second output register
2972   switch (Inst.getOpcode()) {
2973     case ARM::VLD3d8:
2974     case ARM::VLD3d16:
2975     case ARM::VLD3d32:
2976     case ARM::VLD3d8_UPD:
2977     case ARM::VLD3d16_UPD:
2978     case ARM::VLD3d32_UPD:
2979     case ARM::VLD4d8:
2980     case ARM::VLD4d16:
2981     case ARM::VLD4d32:
2982     case ARM::VLD4d8_UPD:
2983     case ARM::VLD4d16_UPD:
2984     case ARM::VLD4d32_UPD:
2985       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
2986         return MCDisassembler::Fail;
2987       break;
2988     case ARM::VLD3q8:
2989     case ARM::VLD3q16:
2990     case ARM::VLD3q32:
2991     case ARM::VLD3q8_UPD:
2992     case ARM::VLD3q16_UPD:
2993     case ARM::VLD3q32_UPD:
2994     case ARM::VLD4q8:
2995     case ARM::VLD4q16:
2996     case ARM::VLD4q32:
2997     case ARM::VLD4q8_UPD:
2998     case ARM::VLD4q16_UPD:
2999     case ARM::VLD4q32_UPD:
3000       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
3001         return MCDisassembler::Fail;
3002       break;
3003     default:
3004       break;
3005   }
3006 
3007   // Third output register
3008   switch(Inst.getOpcode()) {
3009     case ARM::VLD3d8:
3010     case ARM::VLD3d16:
3011     case ARM::VLD3d32:
3012     case ARM::VLD3d8_UPD:
3013     case ARM::VLD3d16_UPD:
3014     case ARM::VLD3d32_UPD:
3015     case ARM::VLD4d8:
3016     case ARM::VLD4d16:
3017     case ARM::VLD4d32:
3018     case ARM::VLD4d8_UPD:
3019     case ARM::VLD4d16_UPD:
3020     case ARM::VLD4d32_UPD:
3021       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
3022         return MCDisassembler::Fail;
3023       break;
3024     case ARM::VLD3q8:
3025     case ARM::VLD3q16:
3026     case ARM::VLD3q32:
3027     case ARM::VLD3q8_UPD:
3028     case ARM::VLD3q16_UPD:
3029     case ARM::VLD3q32_UPD:
3030     case ARM::VLD4q8:
3031     case ARM::VLD4q16:
3032     case ARM::VLD4q32:
3033     case ARM::VLD4q8_UPD:
3034     case ARM::VLD4q16_UPD:
3035     case ARM::VLD4q32_UPD:
3036       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
3037         return MCDisassembler::Fail;
3038       break;
3039     default:
3040       break;
3041   }
3042 
3043   // Fourth output register
3044   switch (Inst.getOpcode()) {
3045     case ARM::VLD4d8:
3046     case ARM::VLD4d16:
3047     case ARM::VLD4d32:
3048     case ARM::VLD4d8_UPD:
3049     case ARM::VLD4d16_UPD:
3050     case ARM::VLD4d32_UPD:
3051       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
3052         return MCDisassembler::Fail;
3053       break;
3054     case ARM::VLD4q8:
3055     case ARM::VLD4q16:
3056     case ARM::VLD4q32:
3057     case ARM::VLD4q8_UPD:
3058     case ARM::VLD4q16_UPD:
3059     case ARM::VLD4q32_UPD:
3060       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
3061         return MCDisassembler::Fail;
3062       break;
3063     default:
3064       break;
3065   }
3066 
3067   // Writeback operand
3068   switch (Inst.getOpcode()) {
3069     case ARM::VLD1d8wb_fixed:
3070     case ARM::VLD1d16wb_fixed:
3071     case ARM::VLD1d32wb_fixed:
3072     case ARM::VLD1d64wb_fixed:
3073     case ARM::VLD1d8wb_register:
3074     case ARM::VLD1d16wb_register:
3075     case ARM::VLD1d32wb_register:
3076     case ARM::VLD1d64wb_register:
3077     case ARM::VLD1q8wb_fixed:
3078     case ARM::VLD1q16wb_fixed:
3079     case ARM::VLD1q32wb_fixed:
3080     case ARM::VLD1q64wb_fixed:
3081     case ARM::VLD1q8wb_register:
3082     case ARM::VLD1q16wb_register:
3083     case ARM::VLD1q32wb_register:
3084     case ARM::VLD1q64wb_register:
3085     case ARM::VLD1d8Twb_fixed:
3086     case ARM::VLD1d8Twb_register:
3087     case ARM::VLD1d16Twb_fixed:
3088     case ARM::VLD1d16Twb_register:
3089     case ARM::VLD1d32Twb_fixed:
3090     case ARM::VLD1d32Twb_register:
3091     case ARM::VLD1d64Twb_fixed:
3092     case ARM::VLD1d64Twb_register:
3093     case ARM::VLD1d8Qwb_fixed:
3094     case ARM::VLD1d8Qwb_register:
3095     case ARM::VLD1d16Qwb_fixed:
3096     case ARM::VLD1d16Qwb_register:
3097     case ARM::VLD1d32Qwb_fixed:
3098     case ARM::VLD1d32Qwb_register:
3099     case ARM::VLD1d64Qwb_fixed:
3100     case ARM::VLD1d64Qwb_register:
3101     case ARM::VLD2d8wb_fixed:
3102     case ARM::VLD2d16wb_fixed:
3103     case ARM::VLD2d32wb_fixed:
3104     case ARM::VLD2q8wb_fixed:
3105     case ARM::VLD2q16wb_fixed:
3106     case ARM::VLD2q32wb_fixed:
3107     case ARM::VLD2d8wb_register:
3108     case ARM::VLD2d16wb_register:
3109     case ARM::VLD2d32wb_register:
3110     case ARM::VLD2q8wb_register:
3111     case ARM::VLD2q16wb_register:
3112     case ARM::VLD2q32wb_register:
3113     case ARM::VLD2b8wb_fixed:
3114     case ARM::VLD2b16wb_fixed:
3115     case ARM::VLD2b32wb_fixed:
3116     case ARM::VLD2b8wb_register:
3117     case ARM::VLD2b16wb_register:
3118     case ARM::VLD2b32wb_register:
3119       Inst.addOperand(MCOperand::createImm(0));
3120       break;
3121     case ARM::VLD3d8_UPD:
3122     case ARM::VLD3d16_UPD:
3123     case ARM::VLD3d32_UPD:
3124     case ARM::VLD3q8_UPD:
3125     case ARM::VLD3q16_UPD:
3126     case ARM::VLD3q32_UPD:
3127     case ARM::VLD4d8_UPD:
3128     case ARM::VLD4d16_UPD:
3129     case ARM::VLD4d32_UPD:
3130     case ARM::VLD4q8_UPD:
3131     case ARM::VLD4q16_UPD:
3132     case ARM::VLD4q32_UPD:
3133       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
3134         return MCDisassembler::Fail;
3135       break;
3136     default:
3137       break;
3138   }
3139 
3140   // AddrMode6 Base (register+alignment)
3141   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
3142     return MCDisassembler::Fail;
3143 
3144   // AddrMode6 Offset (register)
3145   switch (Inst.getOpcode()) {
3146   default:
3147     // The below have been updated to have explicit am6offset split
3148     // between fixed and register offset. For those instructions not
3149     // yet updated, we need to add an additional reg0 operand for the
3150     // fixed variant.
3151     //
3152     // The fixed offset encodes as Rm == 0xd, so we check for that.
3153     if (Rm == 0xd) {
3154       Inst.addOperand(MCOperand::createReg(0));
3155       break;
3156     }
3157     // Fall through to handle the register offset variant.
3158     LLVM_FALLTHROUGH;
3159   case ARM::VLD1d8wb_fixed:
3160   case ARM::VLD1d16wb_fixed:
3161   case ARM::VLD1d32wb_fixed:
3162   case ARM::VLD1d64wb_fixed:
3163   case ARM::VLD1d8Twb_fixed:
3164   case ARM::VLD1d16Twb_fixed:
3165   case ARM::VLD1d32Twb_fixed:
3166   case ARM::VLD1d64Twb_fixed:
3167   case ARM::VLD1d8Qwb_fixed:
3168   case ARM::VLD1d16Qwb_fixed:
3169   case ARM::VLD1d32Qwb_fixed:
3170   case ARM::VLD1d64Qwb_fixed:
3171   case ARM::VLD1d8wb_register:
3172   case ARM::VLD1d16wb_register:
3173   case ARM::VLD1d32wb_register:
3174   case ARM::VLD1d64wb_register:
3175   case ARM::VLD1q8wb_fixed:
3176   case ARM::VLD1q16wb_fixed:
3177   case ARM::VLD1q32wb_fixed:
3178   case ARM::VLD1q64wb_fixed:
3179   case ARM::VLD1q8wb_register:
3180   case ARM::VLD1q16wb_register:
3181   case ARM::VLD1q32wb_register:
3182   case ARM::VLD1q64wb_register:
3183     // The fixed offset post-increment encodes Rm == 0xd. The no-writeback
3184     // variant encodes Rm == 0xf. Anything else is a register offset post-
3185     // increment and we need to add the register operand to the instruction.
3186     if (Rm != 0xD && Rm != 0xF &&
3187         !Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3188       return MCDisassembler::Fail;
3189     break;
3190   case ARM::VLD2d8wb_fixed:
3191   case ARM::VLD2d16wb_fixed:
3192   case ARM::VLD2d32wb_fixed:
3193   case ARM::VLD2b8wb_fixed:
3194   case ARM::VLD2b16wb_fixed:
3195   case ARM::VLD2b32wb_fixed:
3196   case ARM::VLD2q8wb_fixed:
3197   case ARM::VLD2q16wb_fixed:
3198   case ARM::VLD2q32wb_fixed:
3199     break;
3200   }
3201 
3202   return S;
3203 }
3204 
3205 static DecodeStatus DecodeVLDST1Instruction(MCInst &Inst, unsigned Insn,
3206                                             uint64_t Address,
3207                                             const MCDisassembler *Decoder) {
3208   unsigned type = fieldFromInstruction(Insn, 8, 4);
3209   unsigned align = fieldFromInstruction(Insn, 4, 2);
3210   if (type == 6 && (align & 2)) return MCDisassembler::Fail;
3211   if (type == 7 && (align & 2)) return MCDisassembler::Fail;
3212   if (type == 10 && align == 3) return MCDisassembler::Fail;
3213 
3214   unsigned load = fieldFromInstruction(Insn, 21, 1);
3215   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
3216               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
3217 }
3218 
3219 static DecodeStatus DecodeVLDST2Instruction(MCInst &Inst, unsigned Insn,
3220                                             uint64_t Address,
3221                                             const MCDisassembler *Decoder) {
3222   unsigned size = fieldFromInstruction(Insn, 6, 2);
3223   if (size == 3) return MCDisassembler::Fail;
3224 
3225   unsigned type = fieldFromInstruction(Insn, 8, 4);
3226   unsigned align = fieldFromInstruction(Insn, 4, 2);
3227   if (type == 8 && align == 3) return MCDisassembler::Fail;
3228   if (type == 9 && align == 3) return MCDisassembler::Fail;
3229 
3230   unsigned load = fieldFromInstruction(Insn, 21, 1);
3231   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
3232               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
3233 }
3234 
3235 static DecodeStatus DecodeVLDST3Instruction(MCInst &Inst, unsigned Insn,
3236                                             uint64_t Address,
3237                                             const MCDisassembler *Decoder) {
3238   unsigned size = fieldFromInstruction(Insn, 6, 2);
3239   if (size == 3) return MCDisassembler::Fail;
3240 
3241   unsigned align = fieldFromInstruction(Insn, 4, 2);
3242   if (align & 2) return MCDisassembler::Fail;
3243 
3244   unsigned load = fieldFromInstruction(Insn, 21, 1);
3245   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
3246               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
3247 }
3248 
3249 static DecodeStatus DecodeVLDST4Instruction(MCInst &Inst, unsigned Insn,
3250                                             uint64_t Address,
3251                                             const MCDisassembler *Decoder) {
3252   unsigned size = fieldFromInstruction(Insn, 6, 2);
3253   if (size == 3) return MCDisassembler::Fail;
3254 
3255   unsigned load = fieldFromInstruction(Insn, 21, 1);
3256   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
3257               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
3258 }
3259 
3260 static DecodeStatus DecodeVSTInstruction(MCInst &Inst, unsigned Insn,
3261                                          uint64_t Address,
3262                                          const MCDisassembler *Decoder) {
3263   DecodeStatus S = MCDisassembler::Success;
3264 
3265   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3266   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3267   unsigned wb = fieldFromInstruction(Insn, 16, 4);
3268   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3269   Rn |= fieldFromInstruction(Insn, 4, 2) << 4;
3270   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3271 
3272   // Writeback Operand
3273   switch (Inst.getOpcode()) {
3274     case ARM::VST1d8wb_fixed:
3275     case ARM::VST1d16wb_fixed:
3276     case ARM::VST1d32wb_fixed:
3277     case ARM::VST1d64wb_fixed:
3278     case ARM::VST1d8wb_register:
3279     case ARM::VST1d16wb_register:
3280     case ARM::VST1d32wb_register:
3281     case ARM::VST1d64wb_register:
3282     case ARM::VST1q8wb_fixed:
3283     case ARM::VST1q16wb_fixed:
3284     case ARM::VST1q32wb_fixed:
3285     case ARM::VST1q64wb_fixed:
3286     case ARM::VST1q8wb_register:
3287     case ARM::VST1q16wb_register:
3288     case ARM::VST1q32wb_register:
3289     case ARM::VST1q64wb_register:
3290     case ARM::VST1d8Twb_fixed:
3291     case ARM::VST1d16Twb_fixed:
3292     case ARM::VST1d32Twb_fixed:
3293     case ARM::VST1d64Twb_fixed:
3294     case ARM::VST1d8Twb_register:
3295     case ARM::VST1d16Twb_register:
3296     case ARM::VST1d32Twb_register:
3297     case ARM::VST1d64Twb_register:
3298     case ARM::VST1d8Qwb_fixed:
3299     case ARM::VST1d16Qwb_fixed:
3300     case ARM::VST1d32Qwb_fixed:
3301     case ARM::VST1d64Qwb_fixed:
3302     case ARM::VST1d8Qwb_register:
3303     case ARM::VST1d16Qwb_register:
3304     case ARM::VST1d32Qwb_register:
3305     case ARM::VST1d64Qwb_register:
3306     case ARM::VST2d8wb_fixed:
3307     case ARM::VST2d16wb_fixed:
3308     case ARM::VST2d32wb_fixed:
3309     case ARM::VST2d8wb_register:
3310     case ARM::VST2d16wb_register:
3311     case ARM::VST2d32wb_register:
3312     case ARM::VST2q8wb_fixed:
3313     case ARM::VST2q16wb_fixed:
3314     case ARM::VST2q32wb_fixed:
3315     case ARM::VST2q8wb_register:
3316     case ARM::VST2q16wb_register:
3317     case ARM::VST2q32wb_register:
3318     case ARM::VST2b8wb_fixed:
3319     case ARM::VST2b16wb_fixed:
3320     case ARM::VST2b32wb_fixed:
3321     case ARM::VST2b8wb_register:
3322     case ARM::VST2b16wb_register:
3323     case ARM::VST2b32wb_register:
3324       if (Rm == 0xF)
3325         return MCDisassembler::Fail;
3326       Inst.addOperand(MCOperand::createImm(0));
3327       break;
3328     case ARM::VST3d8_UPD:
3329     case ARM::VST3d16_UPD:
3330     case ARM::VST3d32_UPD:
3331     case ARM::VST3q8_UPD:
3332     case ARM::VST3q16_UPD:
3333     case ARM::VST3q32_UPD:
3334     case ARM::VST4d8_UPD:
3335     case ARM::VST4d16_UPD:
3336     case ARM::VST4d32_UPD:
3337     case ARM::VST4q8_UPD:
3338     case ARM::VST4q16_UPD:
3339     case ARM::VST4q32_UPD:
3340       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
3341         return MCDisassembler::Fail;
3342       break;
3343     default:
3344       break;
3345   }
3346 
3347   // AddrMode6 Base (register+alignment)
3348   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
3349     return MCDisassembler::Fail;
3350 
3351   // AddrMode6 Offset (register)
3352   switch (Inst.getOpcode()) {
3353     default:
3354       if (Rm == 0xD)
3355         Inst.addOperand(MCOperand::createReg(0));
3356       else if (Rm != 0xF) {
3357         if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3358           return MCDisassembler::Fail;
3359       }
3360       break;
3361     case ARM::VST1d8wb_fixed:
3362     case ARM::VST1d16wb_fixed:
3363     case ARM::VST1d32wb_fixed:
3364     case ARM::VST1d64wb_fixed:
3365     case ARM::VST1q8wb_fixed:
3366     case ARM::VST1q16wb_fixed:
3367     case ARM::VST1q32wb_fixed:
3368     case ARM::VST1q64wb_fixed:
3369     case ARM::VST1d8Twb_fixed:
3370     case ARM::VST1d16Twb_fixed:
3371     case ARM::VST1d32Twb_fixed:
3372     case ARM::VST1d64Twb_fixed:
3373     case ARM::VST1d8Qwb_fixed:
3374     case ARM::VST1d16Qwb_fixed:
3375     case ARM::VST1d32Qwb_fixed:
3376     case ARM::VST1d64Qwb_fixed:
3377     case ARM::VST2d8wb_fixed:
3378     case ARM::VST2d16wb_fixed:
3379     case ARM::VST2d32wb_fixed:
3380     case ARM::VST2q8wb_fixed:
3381     case ARM::VST2q16wb_fixed:
3382     case ARM::VST2q32wb_fixed:
3383     case ARM::VST2b8wb_fixed:
3384     case ARM::VST2b16wb_fixed:
3385     case ARM::VST2b32wb_fixed:
3386       break;
3387   }
3388 
3389   // First input register
3390   switch (Inst.getOpcode()) {
3391   case ARM::VST1q16:
3392   case ARM::VST1q32:
3393   case ARM::VST1q64:
3394   case ARM::VST1q8:
3395   case ARM::VST1q16wb_fixed:
3396   case ARM::VST1q16wb_register:
3397   case ARM::VST1q32wb_fixed:
3398   case ARM::VST1q32wb_register:
3399   case ARM::VST1q64wb_fixed:
3400   case ARM::VST1q64wb_register:
3401   case ARM::VST1q8wb_fixed:
3402   case ARM::VST1q8wb_register:
3403   case ARM::VST2d16:
3404   case ARM::VST2d32:
3405   case ARM::VST2d8:
3406   case ARM::VST2d16wb_fixed:
3407   case ARM::VST2d16wb_register:
3408   case ARM::VST2d32wb_fixed:
3409   case ARM::VST2d32wb_register:
3410   case ARM::VST2d8wb_fixed:
3411   case ARM::VST2d8wb_register:
3412     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3413       return MCDisassembler::Fail;
3414     break;
3415   case ARM::VST2b16:
3416   case ARM::VST2b32:
3417   case ARM::VST2b8:
3418   case ARM::VST2b16wb_fixed:
3419   case ARM::VST2b16wb_register:
3420   case ARM::VST2b32wb_fixed:
3421   case ARM::VST2b32wb_register:
3422   case ARM::VST2b8wb_fixed:
3423   case ARM::VST2b8wb_register:
3424     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
3425       return MCDisassembler::Fail;
3426     break;
3427   default:
3428     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3429       return MCDisassembler::Fail;
3430   }
3431 
3432   // Second input register
3433   switch (Inst.getOpcode()) {
3434     case ARM::VST3d8:
3435     case ARM::VST3d16:
3436     case ARM::VST3d32:
3437     case ARM::VST3d8_UPD:
3438     case ARM::VST3d16_UPD:
3439     case ARM::VST3d32_UPD:
3440     case ARM::VST4d8:
3441     case ARM::VST4d16:
3442     case ARM::VST4d32:
3443     case ARM::VST4d8_UPD:
3444     case ARM::VST4d16_UPD:
3445     case ARM::VST4d32_UPD:
3446       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
3447         return MCDisassembler::Fail;
3448       break;
3449     case ARM::VST3q8:
3450     case ARM::VST3q16:
3451     case ARM::VST3q32:
3452     case ARM::VST3q8_UPD:
3453     case ARM::VST3q16_UPD:
3454     case ARM::VST3q32_UPD:
3455     case ARM::VST4q8:
3456     case ARM::VST4q16:
3457     case ARM::VST4q32:
3458     case ARM::VST4q8_UPD:
3459     case ARM::VST4q16_UPD:
3460     case ARM::VST4q32_UPD:
3461       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
3462         return MCDisassembler::Fail;
3463       break;
3464     default:
3465       break;
3466   }
3467 
3468   // Third input register
3469   switch (Inst.getOpcode()) {
3470     case ARM::VST3d8:
3471     case ARM::VST3d16:
3472     case ARM::VST3d32:
3473     case ARM::VST3d8_UPD:
3474     case ARM::VST3d16_UPD:
3475     case ARM::VST3d32_UPD:
3476     case ARM::VST4d8:
3477     case ARM::VST4d16:
3478     case ARM::VST4d32:
3479     case ARM::VST4d8_UPD:
3480     case ARM::VST4d16_UPD:
3481     case ARM::VST4d32_UPD:
3482       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
3483         return MCDisassembler::Fail;
3484       break;
3485     case ARM::VST3q8:
3486     case ARM::VST3q16:
3487     case ARM::VST3q32:
3488     case ARM::VST3q8_UPD:
3489     case ARM::VST3q16_UPD:
3490     case ARM::VST3q32_UPD:
3491     case ARM::VST4q8:
3492     case ARM::VST4q16:
3493     case ARM::VST4q32:
3494     case ARM::VST4q8_UPD:
3495     case ARM::VST4q16_UPD:
3496     case ARM::VST4q32_UPD:
3497       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
3498         return MCDisassembler::Fail;
3499       break;
3500     default:
3501       break;
3502   }
3503 
3504   // Fourth input register
3505   switch (Inst.getOpcode()) {
3506     case ARM::VST4d8:
3507     case ARM::VST4d16:
3508     case ARM::VST4d32:
3509     case ARM::VST4d8_UPD:
3510     case ARM::VST4d16_UPD:
3511     case ARM::VST4d32_UPD:
3512       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
3513         return MCDisassembler::Fail;
3514       break;
3515     case ARM::VST4q8:
3516     case ARM::VST4q16:
3517     case ARM::VST4q32:
3518     case ARM::VST4q8_UPD:
3519     case ARM::VST4q16_UPD:
3520     case ARM::VST4q32_UPD:
3521       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
3522         return MCDisassembler::Fail;
3523       break;
3524     default:
3525       break;
3526   }
3527 
3528   return S;
3529 }
3530 
3531 static DecodeStatus DecodeVLD1DupInstruction(MCInst &Inst, unsigned Insn,
3532                                              uint64_t Address,
3533                                              const MCDisassembler *Decoder) {
3534   DecodeStatus S = MCDisassembler::Success;
3535 
3536   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3537   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3538   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3539   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3540   unsigned align = fieldFromInstruction(Insn, 4, 1);
3541   unsigned size = fieldFromInstruction(Insn, 6, 2);
3542 
3543   if (size == 0 && align == 1)
3544     return MCDisassembler::Fail;
3545   align *= (1 << size);
3546 
3547   switch (Inst.getOpcode()) {
3548   case ARM::VLD1DUPq16: case ARM::VLD1DUPq32: case ARM::VLD1DUPq8:
3549   case ARM::VLD1DUPq16wb_fixed: case ARM::VLD1DUPq16wb_register:
3550   case ARM::VLD1DUPq32wb_fixed: case ARM::VLD1DUPq32wb_register:
3551   case ARM::VLD1DUPq8wb_fixed: case ARM::VLD1DUPq8wb_register:
3552     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3553       return MCDisassembler::Fail;
3554     break;
3555   default:
3556     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3557       return MCDisassembler::Fail;
3558     break;
3559   }
3560   if (Rm != 0xF) {
3561     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3562       return MCDisassembler::Fail;
3563   }
3564 
3565   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3566     return MCDisassembler::Fail;
3567   Inst.addOperand(MCOperand::createImm(align));
3568 
3569   // The fixed offset post-increment encodes Rm == 0xd. The no-writeback
3570   // variant encodes Rm == 0xf. Anything else is a register offset post-
3571   // increment and we need to add the register operand to the instruction.
3572   if (Rm != 0xD && Rm != 0xF &&
3573       !Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3574     return MCDisassembler::Fail;
3575 
3576   return S;
3577 }
3578 
3579 static DecodeStatus DecodeVLD2DupInstruction(MCInst &Inst, unsigned Insn,
3580                                              uint64_t Address,
3581                                              const MCDisassembler *Decoder) {
3582   DecodeStatus S = MCDisassembler::Success;
3583 
3584   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3585   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3586   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3587   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3588   unsigned align = fieldFromInstruction(Insn, 4, 1);
3589   unsigned size = 1 << fieldFromInstruction(Insn, 6, 2);
3590   align *= 2*size;
3591 
3592   switch (Inst.getOpcode()) {
3593   case ARM::VLD2DUPd16: case ARM::VLD2DUPd32: case ARM::VLD2DUPd8:
3594   case ARM::VLD2DUPd16wb_fixed: case ARM::VLD2DUPd16wb_register:
3595   case ARM::VLD2DUPd32wb_fixed: case ARM::VLD2DUPd32wb_register:
3596   case ARM::VLD2DUPd8wb_fixed: case ARM::VLD2DUPd8wb_register:
3597     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3598       return MCDisassembler::Fail;
3599     break;
3600   case ARM::VLD2DUPd16x2: case ARM::VLD2DUPd32x2: case ARM::VLD2DUPd8x2:
3601   case ARM::VLD2DUPd16x2wb_fixed: case ARM::VLD2DUPd16x2wb_register:
3602   case ARM::VLD2DUPd32x2wb_fixed: case ARM::VLD2DUPd32x2wb_register:
3603   case ARM::VLD2DUPd8x2wb_fixed: case ARM::VLD2DUPd8x2wb_register:
3604     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
3605       return MCDisassembler::Fail;
3606     break;
3607   default:
3608     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3609       return MCDisassembler::Fail;
3610     break;
3611   }
3612 
3613   if (Rm != 0xF)
3614     Inst.addOperand(MCOperand::createImm(0));
3615 
3616   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3617     return MCDisassembler::Fail;
3618   Inst.addOperand(MCOperand::createImm(align));
3619 
3620   if (Rm != 0xD && Rm != 0xF) {
3621     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3622       return MCDisassembler::Fail;
3623   }
3624 
3625   return S;
3626 }
3627 
3628 static DecodeStatus DecodeVLD3DupInstruction(MCInst &Inst, unsigned Insn,
3629                                              uint64_t Address,
3630                                              const MCDisassembler *Decoder) {
3631   DecodeStatus S = MCDisassembler::Success;
3632 
3633   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3634   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3635   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3636   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3637   unsigned inc = fieldFromInstruction(Insn, 5, 1) + 1;
3638 
3639   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3640     return MCDisassembler::Fail;
3641   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
3642     return MCDisassembler::Fail;
3643   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
3644     return MCDisassembler::Fail;
3645   if (Rm != 0xF) {
3646     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3647       return MCDisassembler::Fail;
3648   }
3649 
3650   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3651     return MCDisassembler::Fail;
3652   Inst.addOperand(MCOperand::createImm(0));
3653 
3654   if (Rm == 0xD)
3655     Inst.addOperand(MCOperand::createReg(0));
3656   else if (Rm != 0xF) {
3657     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3658       return MCDisassembler::Fail;
3659   }
3660 
3661   return S;
3662 }
3663 
3664 static DecodeStatus DecodeVLD4DupInstruction(MCInst &Inst, unsigned Insn,
3665                                              uint64_t Address,
3666                                              const MCDisassembler *Decoder) {
3667   DecodeStatus S = MCDisassembler::Success;
3668 
3669   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3670   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3671   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3672   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3673   unsigned size = fieldFromInstruction(Insn, 6, 2);
3674   unsigned inc = fieldFromInstruction(Insn, 5, 1) + 1;
3675   unsigned align = fieldFromInstruction(Insn, 4, 1);
3676 
3677   if (size == 0x3) {
3678     if (align == 0)
3679       return MCDisassembler::Fail;
3680     align = 16;
3681   } else {
3682     if (size == 2) {
3683       align *= 8;
3684     } else {
3685       size = 1 << size;
3686       align *= 4*size;
3687     }
3688   }
3689 
3690   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3691     return MCDisassembler::Fail;
3692   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
3693     return MCDisassembler::Fail;
3694   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
3695     return MCDisassembler::Fail;
3696   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3*inc)%32, Address, Decoder)))
3697     return MCDisassembler::Fail;
3698   if (Rm != 0xF) {
3699     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3700       return MCDisassembler::Fail;
3701   }
3702 
3703   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3704     return MCDisassembler::Fail;
3705   Inst.addOperand(MCOperand::createImm(align));
3706 
3707   if (Rm == 0xD)
3708     Inst.addOperand(MCOperand::createReg(0));
3709   else if (Rm != 0xF) {
3710     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3711       return MCDisassembler::Fail;
3712   }
3713 
3714   return S;
3715 }
3716 
3717 static DecodeStatus DecodeVMOVModImmInstruction(MCInst &Inst, unsigned Insn,
3718                                                 uint64_t Address,
3719                                                 const MCDisassembler *Decoder) {
3720   DecodeStatus S = MCDisassembler::Success;
3721 
3722   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3723   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3724   unsigned imm = fieldFromInstruction(Insn, 0, 4);
3725   imm |= fieldFromInstruction(Insn, 16, 3) << 4;
3726   imm |= fieldFromInstruction(Insn, 24, 1) << 7;
3727   imm |= fieldFromInstruction(Insn, 8, 4) << 8;
3728   imm |= fieldFromInstruction(Insn, 5, 1) << 12;
3729   unsigned Q = fieldFromInstruction(Insn, 6, 1);
3730 
3731   if (Q) {
3732     if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3733     return MCDisassembler::Fail;
3734   } else {
3735     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3736     return MCDisassembler::Fail;
3737   }
3738 
3739   Inst.addOperand(MCOperand::createImm(imm));
3740 
3741   switch (Inst.getOpcode()) {
3742     case ARM::VORRiv4i16:
3743     case ARM::VORRiv2i32:
3744     case ARM::VBICiv4i16:
3745     case ARM::VBICiv2i32:
3746       if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3747         return MCDisassembler::Fail;
3748       break;
3749     case ARM::VORRiv8i16:
3750     case ARM::VORRiv4i32:
3751     case ARM::VBICiv8i16:
3752     case ARM::VBICiv4i32:
3753       if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3754         return MCDisassembler::Fail;
3755       break;
3756     default:
3757       break;
3758   }
3759 
3760   return S;
3761 }
3762 
3763 static DecodeStatus DecodeMVEModImmInstruction(MCInst &Inst, unsigned Insn,
3764                                                uint64_t Address,
3765                                                const MCDisassembler *Decoder) {
3766   DecodeStatus S = MCDisassembler::Success;
3767 
3768   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
3769                  fieldFromInstruction(Insn, 13, 3));
3770   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
3771   unsigned imm = fieldFromInstruction(Insn, 0, 4);
3772   imm |= fieldFromInstruction(Insn, 16, 3) << 4;
3773   imm |= fieldFromInstruction(Insn, 28, 1) << 7;
3774   imm |= cmode                             << 8;
3775   imm |= fieldFromInstruction(Insn, 5, 1)  << 12;
3776 
3777   if (cmode == 0xF && Inst.getOpcode() == ARM::MVE_VMVNimmi32)
3778     return MCDisassembler::Fail;
3779 
3780   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
3781     return MCDisassembler::Fail;
3782 
3783   Inst.addOperand(MCOperand::createImm(imm));
3784 
3785   Inst.addOperand(MCOperand::createImm(ARMVCC::None));
3786   Inst.addOperand(MCOperand::createReg(0));
3787   Inst.addOperand(MCOperand::createImm(0));
3788 
3789   return S;
3790 }
3791 
3792 static DecodeStatus DecodeMVEVADCInstruction(MCInst &Inst, unsigned Insn,
3793                                              uint64_t Address,
3794                                              const MCDisassembler *Decoder) {
3795   DecodeStatus S = MCDisassembler::Success;
3796 
3797   unsigned Qd = fieldFromInstruction(Insn, 13, 3);
3798   Qd |= fieldFromInstruction(Insn, 22, 1) << 3;
3799   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
3800     return MCDisassembler::Fail;
3801   Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
3802 
3803   unsigned Qn = fieldFromInstruction(Insn, 17, 3);
3804   Qn |= fieldFromInstruction(Insn, 7, 1) << 3;
3805   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qn, Address, Decoder)))
3806     return MCDisassembler::Fail;
3807   unsigned Qm = fieldFromInstruction(Insn, 1, 3);
3808   Qm |= fieldFromInstruction(Insn, 5, 1) << 3;
3809   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
3810     return MCDisassembler::Fail;
3811   if (!fieldFromInstruction(Insn, 12, 1)) // I bit clear => need input FPSCR
3812     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
3813   Inst.addOperand(MCOperand::createImm(Qd));
3814 
3815   return S;
3816 }
3817 
3818 static DecodeStatus DecodeVSHLMaxInstruction(MCInst &Inst, unsigned Insn,
3819                                              uint64_t Address,
3820                                              const MCDisassembler *Decoder) {
3821   DecodeStatus S = MCDisassembler::Success;
3822 
3823   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3824   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3825   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3826   Rm |= fieldFromInstruction(Insn, 5, 1) << 4;
3827   unsigned size = fieldFromInstruction(Insn, 18, 2);
3828 
3829   if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3830     return MCDisassembler::Fail;
3831   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
3832     return MCDisassembler::Fail;
3833   Inst.addOperand(MCOperand::createImm(8 << size));
3834 
3835   return S;
3836 }
3837 
3838 static DecodeStatus DecodeShiftRight8Imm(MCInst &Inst, unsigned Val,
3839                                          uint64_t Address,
3840                                          const MCDisassembler *Decoder) {
3841   Inst.addOperand(MCOperand::createImm(8 - Val));
3842   return MCDisassembler::Success;
3843 }
3844 
3845 static DecodeStatus DecodeShiftRight16Imm(MCInst &Inst, unsigned Val,
3846                                           uint64_t Address,
3847                                           const MCDisassembler *Decoder) {
3848   Inst.addOperand(MCOperand::createImm(16 - Val));
3849   return MCDisassembler::Success;
3850 }
3851 
3852 static DecodeStatus DecodeShiftRight32Imm(MCInst &Inst, unsigned Val,
3853                                           uint64_t Address,
3854                                           const MCDisassembler *Decoder) {
3855   Inst.addOperand(MCOperand::createImm(32 - Val));
3856   return MCDisassembler::Success;
3857 }
3858 
3859 static DecodeStatus DecodeShiftRight64Imm(MCInst &Inst, unsigned Val,
3860                                           uint64_t Address,
3861                                           const MCDisassembler *Decoder) {
3862   Inst.addOperand(MCOperand::createImm(64 - Val));
3863   return MCDisassembler::Success;
3864 }
3865 
3866 static DecodeStatus DecodeTBLInstruction(MCInst &Inst, unsigned Insn,
3867                                          uint64_t Address,
3868                                          const MCDisassembler *Decoder) {
3869   DecodeStatus S = MCDisassembler::Success;
3870 
3871   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3872   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3873   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3874   Rn |= fieldFromInstruction(Insn, 7, 1) << 4;
3875   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3876   Rm |= fieldFromInstruction(Insn, 5, 1) << 4;
3877   unsigned op = fieldFromInstruction(Insn, 6, 1);
3878 
3879   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3880     return MCDisassembler::Fail;
3881   if (op) {
3882     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3883     return MCDisassembler::Fail; // Writeback
3884   }
3885 
3886   switch (Inst.getOpcode()) {
3887   case ARM::VTBL2:
3888   case ARM::VTBX2:
3889     if (!Check(S, DecodeDPairRegisterClass(Inst, Rn, Address, Decoder)))
3890       return MCDisassembler::Fail;
3891     break;
3892   default:
3893     if (!Check(S, DecodeDPRRegisterClass(Inst, Rn, Address, Decoder)))
3894       return MCDisassembler::Fail;
3895   }
3896 
3897   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
3898     return MCDisassembler::Fail;
3899 
3900   return S;
3901 }
3902 
3903 static DecodeStatus DecodeThumbAddSpecialReg(MCInst &Inst, uint16_t Insn,
3904                                              uint64_t Address,
3905                                              const MCDisassembler *Decoder) {
3906   DecodeStatus S = MCDisassembler::Success;
3907 
3908   unsigned dst = fieldFromInstruction(Insn, 8, 3);
3909   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3910 
3911   if (!Check(S, DecodetGPRRegisterClass(Inst, dst, Address, Decoder)))
3912     return MCDisassembler::Fail;
3913 
3914   switch(Inst.getOpcode()) {
3915     default:
3916       return MCDisassembler::Fail;
3917     case ARM::tADR:
3918       break; // tADR does not explicitly represent the PC as an operand.
3919     case ARM::tADDrSPi:
3920       Inst.addOperand(MCOperand::createReg(ARM::SP));
3921       break;
3922   }
3923 
3924   Inst.addOperand(MCOperand::createImm(imm));
3925   return S;
3926 }
3927 
3928 static DecodeStatus DecodeThumbBROperand(MCInst &Inst, unsigned Val,
3929                                          uint64_t Address,
3930                                          const MCDisassembler *Decoder) {
3931   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<12>(Val<<1) + 4,
3932                                 true, 2, Inst, Decoder))
3933     Inst.addOperand(MCOperand::createImm(SignExtend32<12>(Val << 1)));
3934   return MCDisassembler::Success;
3935 }
3936 
3937 static DecodeStatus DecodeT2BROperand(MCInst &Inst, unsigned Val,
3938                                       uint64_t Address,
3939                                       const MCDisassembler *Decoder) {
3940   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<21>(Val) + 4,
3941                                 true, 4, Inst, Decoder))
3942     Inst.addOperand(MCOperand::createImm(SignExtend32<21>(Val)));
3943   return MCDisassembler::Success;
3944 }
3945 
3946 static DecodeStatus DecodeThumbCmpBROperand(MCInst &Inst, unsigned Val,
3947                                             uint64_t Address,
3948                                             const MCDisassembler *Decoder) {
3949   if (!tryAddingSymbolicOperand(Address, Address + (Val<<1) + 4,
3950                                 true, 2, Inst, Decoder))
3951     Inst.addOperand(MCOperand::createImm(Val << 1));
3952   return MCDisassembler::Success;
3953 }
3954 
3955 static DecodeStatus DecodeThumbAddrModeRR(MCInst &Inst, unsigned Val,
3956                                           uint64_t Address,
3957                                           const MCDisassembler *Decoder) {
3958   DecodeStatus S = MCDisassembler::Success;
3959 
3960   unsigned Rn = fieldFromInstruction(Val, 0, 3);
3961   unsigned Rm = fieldFromInstruction(Val, 3, 3);
3962 
3963   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
3964     return MCDisassembler::Fail;
3965   if (!Check(S, DecodetGPRRegisterClass(Inst, Rm, Address, Decoder)))
3966     return MCDisassembler::Fail;
3967 
3968   return S;
3969 }
3970 
3971 static DecodeStatus DecodeThumbAddrModeIS(MCInst &Inst, unsigned Val,
3972                                           uint64_t Address,
3973                                           const MCDisassembler *Decoder) {
3974   DecodeStatus S = MCDisassembler::Success;
3975 
3976   unsigned Rn = fieldFromInstruction(Val, 0, 3);
3977   unsigned imm = fieldFromInstruction(Val, 3, 5);
3978 
3979   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
3980     return MCDisassembler::Fail;
3981   Inst.addOperand(MCOperand::createImm(imm));
3982 
3983   return S;
3984 }
3985 
3986 static DecodeStatus DecodeThumbAddrModePC(MCInst &Inst, unsigned Val,
3987                                           uint64_t Address,
3988                                           const MCDisassembler *Decoder) {
3989   unsigned imm = Val << 2;
3990 
3991   Inst.addOperand(MCOperand::createImm(imm));
3992   tryAddingPcLoadReferenceComment(Address, (Address & ~2u) + imm + 4, Decoder);
3993 
3994   return MCDisassembler::Success;
3995 }
3996 
3997 static DecodeStatus DecodeThumbAddrModeSP(MCInst &Inst, unsigned Val,
3998                                           uint64_t Address,
3999                                           const MCDisassembler *Decoder) {
4000   Inst.addOperand(MCOperand::createReg(ARM::SP));
4001   Inst.addOperand(MCOperand::createImm(Val));
4002 
4003   return MCDisassembler::Success;
4004 }
4005 
4006 static DecodeStatus DecodeT2AddrModeSOReg(MCInst &Inst, unsigned Val,
4007                                           uint64_t Address,
4008                                           const MCDisassembler *Decoder) {
4009   DecodeStatus S = MCDisassembler::Success;
4010 
4011   unsigned Rn = fieldFromInstruction(Val, 6, 4);
4012   unsigned Rm = fieldFromInstruction(Val, 2, 4);
4013   unsigned imm = fieldFromInstruction(Val, 0, 2);
4014 
4015   // Thumb stores cannot use PC as dest register.
4016   switch (Inst.getOpcode()) {
4017   case ARM::t2STRHs:
4018   case ARM::t2STRBs:
4019   case ARM::t2STRs:
4020     if (Rn == 15)
4021       return MCDisassembler::Fail;
4022     break;
4023   default:
4024     break;
4025   }
4026 
4027   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4028     return MCDisassembler::Fail;
4029   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
4030     return MCDisassembler::Fail;
4031   Inst.addOperand(MCOperand::createImm(imm));
4032 
4033   return S;
4034 }
4035 
4036 static DecodeStatus DecodeT2LoadShift(MCInst &Inst, unsigned Insn,
4037                                       uint64_t Address,
4038                                       const MCDisassembler *Decoder) {
4039   DecodeStatus S = MCDisassembler::Success;
4040 
4041   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4042   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4043 
4044   const FeatureBitset &featureBits =
4045     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4046 
4047   bool hasMP = featureBits[ARM::FeatureMP];
4048   bool hasV7Ops = featureBits[ARM::HasV7Ops];
4049 
4050   if (Rn == 15) {
4051     switch (Inst.getOpcode()) {
4052     case ARM::t2LDRBs:
4053       Inst.setOpcode(ARM::t2LDRBpci);
4054       break;
4055     case ARM::t2LDRHs:
4056       Inst.setOpcode(ARM::t2LDRHpci);
4057       break;
4058     case ARM::t2LDRSHs:
4059       Inst.setOpcode(ARM::t2LDRSHpci);
4060       break;
4061     case ARM::t2LDRSBs:
4062       Inst.setOpcode(ARM::t2LDRSBpci);
4063       break;
4064     case ARM::t2LDRs:
4065       Inst.setOpcode(ARM::t2LDRpci);
4066       break;
4067     case ARM::t2PLDs:
4068       Inst.setOpcode(ARM::t2PLDpci);
4069       break;
4070     case ARM::t2PLIs:
4071       Inst.setOpcode(ARM::t2PLIpci);
4072       break;
4073     default:
4074       return MCDisassembler::Fail;
4075     }
4076 
4077     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
4078   }
4079 
4080   if (Rt == 15) {
4081     switch (Inst.getOpcode()) {
4082     case ARM::t2LDRSHs:
4083       return MCDisassembler::Fail;
4084     case ARM::t2LDRHs:
4085       Inst.setOpcode(ARM::t2PLDWs);
4086       break;
4087     case ARM::t2LDRSBs:
4088       Inst.setOpcode(ARM::t2PLIs);
4089       break;
4090     default:
4091       break;
4092     }
4093   }
4094 
4095   switch (Inst.getOpcode()) {
4096     case ARM::t2PLDs:
4097       break;
4098     case ARM::t2PLIs:
4099       if (!hasV7Ops)
4100         return MCDisassembler::Fail;
4101       break;
4102     case ARM::t2PLDWs:
4103       if (!hasV7Ops || !hasMP)
4104         return MCDisassembler::Fail;
4105       break;
4106     default:
4107       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4108         return MCDisassembler::Fail;
4109   }
4110 
4111   unsigned addrmode = fieldFromInstruction(Insn, 4, 2);
4112   addrmode |= fieldFromInstruction(Insn, 0, 4) << 2;
4113   addrmode |= fieldFromInstruction(Insn, 16, 4) << 6;
4114   if (!Check(S, DecodeT2AddrModeSOReg(Inst, addrmode, Address, Decoder)))
4115     return MCDisassembler::Fail;
4116 
4117   return S;
4118 }
4119 
4120 static DecodeStatus DecodeT2LoadImm8(MCInst &Inst, unsigned Insn,
4121                                      uint64_t Address,
4122                                      const MCDisassembler *Decoder) {
4123   DecodeStatus S = MCDisassembler::Success;
4124 
4125   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4126   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4127   unsigned U = fieldFromInstruction(Insn, 9, 1);
4128   unsigned imm = fieldFromInstruction(Insn, 0, 8);
4129   imm |= (U << 8);
4130   imm |= (Rn << 9);
4131   unsigned add = fieldFromInstruction(Insn, 9, 1);
4132 
4133   const FeatureBitset &featureBits =
4134     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4135 
4136   bool hasMP = featureBits[ARM::FeatureMP];
4137   bool hasV7Ops = featureBits[ARM::HasV7Ops];
4138 
4139   if (Rn == 15) {
4140     switch (Inst.getOpcode()) {
4141     case ARM::t2LDRi8:
4142       Inst.setOpcode(ARM::t2LDRpci);
4143       break;
4144     case ARM::t2LDRBi8:
4145       Inst.setOpcode(ARM::t2LDRBpci);
4146       break;
4147     case ARM::t2LDRSBi8:
4148       Inst.setOpcode(ARM::t2LDRSBpci);
4149       break;
4150     case ARM::t2LDRHi8:
4151       Inst.setOpcode(ARM::t2LDRHpci);
4152       break;
4153     case ARM::t2LDRSHi8:
4154       Inst.setOpcode(ARM::t2LDRSHpci);
4155       break;
4156     case ARM::t2PLDi8:
4157       Inst.setOpcode(ARM::t2PLDpci);
4158       break;
4159     case ARM::t2PLIi8:
4160       Inst.setOpcode(ARM::t2PLIpci);
4161       break;
4162     default:
4163       return MCDisassembler::Fail;
4164     }
4165     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
4166   }
4167 
4168   if (Rt == 15) {
4169     switch (Inst.getOpcode()) {
4170     case ARM::t2LDRSHi8:
4171       return MCDisassembler::Fail;
4172     case ARM::t2LDRHi8:
4173       if (!add)
4174         Inst.setOpcode(ARM::t2PLDWi8);
4175       break;
4176     case ARM::t2LDRSBi8:
4177       Inst.setOpcode(ARM::t2PLIi8);
4178       break;
4179     default:
4180       break;
4181     }
4182   }
4183 
4184   switch (Inst.getOpcode()) {
4185   case ARM::t2PLDi8:
4186     break;
4187   case ARM::t2PLIi8:
4188     if (!hasV7Ops)
4189       return MCDisassembler::Fail;
4190     break;
4191   case ARM::t2PLDWi8:
4192       if (!hasV7Ops || !hasMP)
4193         return MCDisassembler::Fail;
4194       break;
4195   default:
4196     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4197       return MCDisassembler::Fail;
4198   }
4199 
4200   if (!Check(S, DecodeT2AddrModeImm8(Inst, imm, Address, Decoder)))
4201     return MCDisassembler::Fail;
4202   return S;
4203 }
4204 
4205 static DecodeStatus DecodeT2LoadImm12(MCInst &Inst, unsigned Insn,
4206                                       uint64_t Address,
4207                                       const MCDisassembler *Decoder) {
4208   DecodeStatus S = MCDisassembler::Success;
4209 
4210   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4211   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4212   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4213   imm |= (Rn << 13);
4214 
4215   const FeatureBitset &featureBits =
4216     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4217 
4218   bool hasMP = featureBits[ARM::FeatureMP];
4219   bool hasV7Ops = featureBits[ARM::HasV7Ops];
4220 
4221   if (Rn == 15) {
4222     switch (Inst.getOpcode()) {
4223     case ARM::t2LDRi12:
4224       Inst.setOpcode(ARM::t2LDRpci);
4225       break;
4226     case ARM::t2LDRHi12:
4227       Inst.setOpcode(ARM::t2LDRHpci);
4228       break;
4229     case ARM::t2LDRSHi12:
4230       Inst.setOpcode(ARM::t2LDRSHpci);
4231       break;
4232     case ARM::t2LDRBi12:
4233       Inst.setOpcode(ARM::t2LDRBpci);
4234       break;
4235     case ARM::t2LDRSBi12:
4236       Inst.setOpcode(ARM::t2LDRSBpci);
4237       break;
4238     case ARM::t2PLDi12:
4239       Inst.setOpcode(ARM::t2PLDpci);
4240       break;
4241     case ARM::t2PLIi12:
4242       Inst.setOpcode(ARM::t2PLIpci);
4243       break;
4244     default:
4245       return MCDisassembler::Fail;
4246     }
4247     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
4248   }
4249 
4250   if (Rt == 15) {
4251     switch (Inst.getOpcode()) {
4252     case ARM::t2LDRSHi12:
4253       return MCDisassembler::Fail;
4254     case ARM::t2LDRHi12:
4255       Inst.setOpcode(ARM::t2PLDWi12);
4256       break;
4257     case ARM::t2LDRSBi12:
4258       Inst.setOpcode(ARM::t2PLIi12);
4259       break;
4260     default:
4261       break;
4262     }
4263   }
4264 
4265   switch (Inst.getOpcode()) {
4266   case ARM::t2PLDi12:
4267     break;
4268   case ARM::t2PLIi12:
4269     if (!hasV7Ops)
4270       return MCDisassembler::Fail;
4271     break;
4272   case ARM::t2PLDWi12:
4273       if (!hasV7Ops || !hasMP)
4274         return MCDisassembler::Fail;
4275       break;
4276   default:
4277     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4278       return MCDisassembler::Fail;
4279   }
4280 
4281   if (!Check(S, DecodeT2AddrModeImm12(Inst, imm, Address, Decoder)))
4282     return MCDisassembler::Fail;
4283   return S;
4284 }
4285 
4286 static DecodeStatus DecodeT2LoadT(MCInst &Inst, unsigned Insn, uint64_t Address,
4287                                   const MCDisassembler *Decoder) {
4288   DecodeStatus S = MCDisassembler::Success;
4289 
4290   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4291   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4292   unsigned imm = fieldFromInstruction(Insn, 0, 8);
4293   imm |= (Rn << 9);
4294 
4295   if (Rn == 15) {
4296     switch (Inst.getOpcode()) {
4297     case ARM::t2LDRT:
4298       Inst.setOpcode(ARM::t2LDRpci);
4299       break;
4300     case ARM::t2LDRBT:
4301       Inst.setOpcode(ARM::t2LDRBpci);
4302       break;
4303     case ARM::t2LDRHT:
4304       Inst.setOpcode(ARM::t2LDRHpci);
4305       break;
4306     case ARM::t2LDRSBT:
4307       Inst.setOpcode(ARM::t2LDRSBpci);
4308       break;
4309     case ARM::t2LDRSHT:
4310       Inst.setOpcode(ARM::t2LDRSHpci);
4311       break;
4312     default:
4313       return MCDisassembler::Fail;
4314     }
4315     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
4316   }
4317 
4318   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
4319     return MCDisassembler::Fail;
4320   if (!Check(S, DecodeT2AddrModeImm8(Inst, imm, Address, Decoder)))
4321     return MCDisassembler::Fail;
4322   return S;
4323 }
4324 
4325 static DecodeStatus DecodeT2LoadLabel(MCInst &Inst, unsigned Insn,
4326                                       uint64_t Address,
4327                                       const MCDisassembler *Decoder) {
4328   DecodeStatus S = MCDisassembler::Success;
4329 
4330   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4331   unsigned U = fieldFromInstruction(Insn, 23, 1);
4332   int imm = fieldFromInstruction(Insn, 0, 12);
4333 
4334   const FeatureBitset &featureBits =
4335     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4336 
4337   bool hasV7Ops = featureBits[ARM::HasV7Ops];
4338 
4339   if (Rt == 15) {
4340     switch (Inst.getOpcode()) {
4341       case ARM::t2LDRBpci:
4342       case ARM::t2LDRHpci:
4343         Inst.setOpcode(ARM::t2PLDpci);
4344         break;
4345       case ARM::t2LDRSBpci:
4346         Inst.setOpcode(ARM::t2PLIpci);
4347         break;
4348       case ARM::t2LDRSHpci:
4349         return MCDisassembler::Fail;
4350       default:
4351         break;
4352     }
4353   }
4354 
4355   switch(Inst.getOpcode()) {
4356   case ARM::t2PLDpci:
4357     break;
4358   case ARM::t2PLIpci:
4359     if (!hasV7Ops)
4360       return MCDisassembler::Fail;
4361     break;
4362   default:
4363     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4364       return MCDisassembler::Fail;
4365   }
4366 
4367   if (!U) {
4368     // Special case for #-0.
4369     if (imm == 0)
4370       imm = INT32_MIN;
4371     else
4372       imm = -imm;
4373   }
4374   Inst.addOperand(MCOperand::createImm(imm));
4375 
4376   return S;
4377 }
4378 
4379 static DecodeStatus DecodeT2Imm8S4(MCInst &Inst, unsigned Val, uint64_t Address,
4380                                    const MCDisassembler *Decoder) {
4381   if (Val == 0)
4382     Inst.addOperand(MCOperand::createImm(INT32_MIN));
4383   else {
4384     int imm = Val & 0xFF;
4385 
4386     if (!(Val & 0x100)) imm *= -1;
4387     Inst.addOperand(MCOperand::createImm(imm * 4));
4388   }
4389 
4390   return MCDisassembler::Success;
4391 }
4392 
4393 static DecodeStatus DecodeT2Imm7S4(MCInst &Inst, unsigned Val, uint64_t Address,
4394                                    const MCDisassembler *Decoder) {
4395   if (Val == 0)
4396     Inst.addOperand(MCOperand::createImm(INT32_MIN));
4397   else {
4398     int imm = Val & 0x7F;
4399 
4400     if (!(Val & 0x80))
4401       imm *= -1;
4402     Inst.addOperand(MCOperand::createImm(imm * 4));
4403   }
4404 
4405   return MCDisassembler::Success;
4406 }
4407 
4408 static DecodeStatus DecodeT2AddrModeImm8s4(MCInst &Inst, unsigned Val,
4409                                            uint64_t Address,
4410                                            const MCDisassembler *Decoder) {
4411   DecodeStatus S = MCDisassembler::Success;
4412 
4413   unsigned Rn = fieldFromInstruction(Val, 9, 4);
4414   unsigned imm = fieldFromInstruction(Val, 0, 9);
4415 
4416   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4417     return MCDisassembler::Fail;
4418   if (!Check(S, DecodeT2Imm8S4(Inst, imm, Address, Decoder)))
4419     return MCDisassembler::Fail;
4420 
4421   return S;
4422 }
4423 
4424 static DecodeStatus DecodeT2AddrModeImm7s4(MCInst &Inst, unsigned Val,
4425                                            uint64_t Address,
4426                                            const MCDisassembler *Decoder) {
4427   DecodeStatus S = MCDisassembler::Success;
4428 
4429   unsigned Rn = fieldFromInstruction(Val, 8, 4);
4430   unsigned imm = fieldFromInstruction(Val, 0, 8);
4431 
4432   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4433     return MCDisassembler::Fail;
4434   if (!Check(S, DecodeT2Imm7S4(Inst, imm, Address, Decoder)))
4435     return MCDisassembler::Fail;
4436 
4437   return S;
4438 }
4439 
4440 static DecodeStatus DecodeT2AddrModeImm0_1020s4(MCInst &Inst, unsigned Val,
4441                                                 uint64_t Address,
4442                                                 const MCDisassembler *Decoder) {
4443   DecodeStatus S = MCDisassembler::Success;
4444 
4445   unsigned Rn = fieldFromInstruction(Val, 8, 4);
4446   unsigned imm = fieldFromInstruction(Val, 0, 8);
4447 
4448   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4449     return MCDisassembler::Fail;
4450 
4451   Inst.addOperand(MCOperand::createImm(imm));
4452 
4453   return S;
4454 }
4455 
4456 static DecodeStatus DecodeT2Imm8(MCInst &Inst, unsigned Val, uint64_t Address,
4457                                  const MCDisassembler *Decoder) {
4458   int imm = Val & 0xFF;
4459   if (Val == 0)
4460     imm = INT32_MIN;
4461   else if (!(Val & 0x100))
4462     imm *= -1;
4463   Inst.addOperand(MCOperand::createImm(imm));
4464 
4465   return MCDisassembler::Success;
4466 }
4467 
4468 template <int shift>
4469 static DecodeStatus DecodeT2Imm7(MCInst &Inst, unsigned Val, uint64_t Address,
4470                                  const MCDisassembler *Decoder) {
4471   int imm = Val & 0x7F;
4472   if (Val == 0)
4473     imm = INT32_MIN;
4474   else if (!(Val & 0x80))
4475     imm *= -1;
4476   if (imm != INT32_MIN)
4477     imm *= (1U << shift);
4478   Inst.addOperand(MCOperand::createImm(imm));
4479 
4480   return MCDisassembler::Success;
4481 }
4482 
4483 static DecodeStatus DecodeT2AddrModeImm8(MCInst &Inst, unsigned Val,
4484                                          uint64_t Address,
4485                                          const MCDisassembler *Decoder) {
4486   DecodeStatus S = MCDisassembler::Success;
4487 
4488   unsigned Rn = fieldFromInstruction(Val, 9, 4);
4489   unsigned imm = fieldFromInstruction(Val, 0, 9);
4490 
4491   // Thumb stores cannot use PC as dest register.
4492   switch (Inst.getOpcode()) {
4493   case ARM::t2STRT:
4494   case ARM::t2STRBT:
4495   case ARM::t2STRHT:
4496   case ARM::t2STRi8:
4497   case ARM::t2STRHi8:
4498   case ARM::t2STRBi8:
4499     if (Rn == 15)
4500       return MCDisassembler::Fail;
4501     break;
4502   default:
4503     break;
4504   }
4505 
4506   // Some instructions always use an additive offset.
4507   switch (Inst.getOpcode()) {
4508     case ARM::t2LDRT:
4509     case ARM::t2LDRBT:
4510     case ARM::t2LDRHT:
4511     case ARM::t2LDRSBT:
4512     case ARM::t2LDRSHT:
4513     case ARM::t2STRT:
4514     case ARM::t2STRBT:
4515     case ARM::t2STRHT:
4516       imm |= 0x100;
4517       break;
4518     default:
4519       break;
4520   }
4521 
4522   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4523     return MCDisassembler::Fail;
4524   if (!Check(S, DecodeT2Imm8(Inst, imm, Address, Decoder)))
4525     return MCDisassembler::Fail;
4526 
4527   return S;
4528 }
4529 
4530 template <int shift>
4531 static DecodeStatus DecodeTAddrModeImm7(MCInst &Inst, unsigned Val,
4532                                         uint64_t Address,
4533                                         const MCDisassembler *Decoder) {
4534   DecodeStatus S = MCDisassembler::Success;
4535 
4536   unsigned Rn = fieldFromInstruction(Val, 8, 3);
4537   unsigned imm = fieldFromInstruction(Val, 0, 8);
4538 
4539   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
4540     return MCDisassembler::Fail;
4541   if (!Check(S, DecodeT2Imm7<shift>(Inst, imm, Address, Decoder)))
4542     return MCDisassembler::Fail;
4543 
4544   return S;
4545 }
4546 
4547 template <int shift, int WriteBack>
4548 static DecodeStatus DecodeT2AddrModeImm7(MCInst &Inst, unsigned Val,
4549                                          uint64_t Address,
4550                                          const MCDisassembler *Decoder) {
4551   DecodeStatus S = MCDisassembler::Success;
4552 
4553   unsigned Rn = fieldFromInstruction(Val, 8, 4);
4554   unsigned imm = fieldFromInstruction(Val, 0, 8);
4555   if (WriteBack) {
4556     if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
4557       return MCDisassembler::Fail;
4558   } else if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4559     return MCDisassembler::Fail;
4560   if (!Check(S, DecodeT2Imm7<shift>(Inst, imm, Address, Decoder)))
4561     return MCDisassembler::Fail;
4562 
4563   return S;
4564 }
4565 
4566 static DecodeStatus DecodeT2LdStPre(MCInst &Inst, unsigned Insn,
4567                                     uint64_t Address,
4568                                     const MCDisassembler *Decoder) {
4569   DecodeStatus S = MCDisassembler::Success;
4570 
4571   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4572   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4573   unsigned addr = fieldFromInstruction(Insn, 0, 8);
4574   addr |= fieldFromInstruction(Insn, 9, 1) << 8;
4575   addr |= Rn << 9;
4576   unsigned load = fieldFromInstruction(Insn, 20, 1);
4577 
4578   if (Rn == 15) {
4579     switch (Inst.getOpcode()) {
4580     case ARM::t2LDR_PRE:
4581     case ARM::t2LDR_POST:
4582       Inst.setOpcode(ARM::t2LDRpci);
4583       break;
4584     case ARM::t2LDRB_PRE:
4585     case ARM::t2LDRB_POST:
4586       Inst.setOpcode(ARM::t2LDRBpci);
4587       break;
4588     case ARM::t2LDRH_PRE:
4589     case ARM::t2LDRH_POST:
4590       Inst.setOpcode(ARM::t2LDRHpci);
4591       break;
4592     case ARM::t2LDRSB_PRE:
4593     case ARM::t2LDRSB_POST:
4594       if (Rt == 15)
4595         Inst.setOpcode(ARM::t2PLIpci);
4596       else
4597         Inst.setOpcode(ARM::t2LDRSBpci);
4598       break;
4599     case ARM::t2LDRSH_PRE:
4600     case ARM::t2LDRSH_POST:
4601       Inst.setOpcode(ARM::t2LDRSHpci);
4602       break;
4603     default:
4604       return MCDisassembler::Fail;
4605     }
4606     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
4607   }
4608 
4609   if (!load) {
4610     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4611       return MCDisassembler::Fail;
4612   }
4613 
4614   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4615     return MCDisassembler::Fail;
4616 
4617   if (load) {
4618     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4619       return MCDisassembler::Fail;
4620   }
4621 
4622   if (!Check(S, DecodeT2AddrModeImm8(Inst, addr, Address, Decoder)))
4623     return MCDisassembler::Fail;
4624 
4625   return S;
4626 }
4627 
4628 static DecodeStatus DecodeT2AddrModeImm12(MCInst &Inst, unsigned Val,
4629                                           uint64_t Address,
4630                                           const MCDisassembler *Decoder) {
4631   DecodeStatus S = MCDisassembler::Success;
4632 
4633   unsigned Rn = fieldFromInstruction(Val, 13, 4);
4634   unsigned imm = fieldFromInstruction(Val, 0, 12);
4635 
4636   // Thumb stores cannot use PC as dest register.
4637   switch (Inst.getOpcode()) {
4638   case ARM::t2STRi12:
4639   case ARM::t2STRBi12:
4640   case ARM::t2STRHi12:
4641     if (Rn == 15)
4642       return MCDisassembler::Fail;
4643     break;
4644   default:
4645     break;
4646   }
4647 
4648   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4649     return MCDisassembler::Fail;
4650   Inst.addOperand(MCOperand::createImm(imm));
4651 
4652   return S;
4653 }
4654 
4655 static DecodeStatus DecodeThumbAddSPImm(MCInst &Inst, uint16_t Insn,
4656                                         uint64_t Address,
4657                                         const MCDisassembler *Decoder) {
4658   unsigned imm = fieldFromInstruction(Insn, 0, 7);
4659 
4660   Inst.addOperand(MCOperand::createReg(ARM::SP));
4661   Inst.addOperand(MCOperand::createReg(ARM::SP));
4662   Inst.addOperand(MCOperand::createImm(imm));
4663 
4664   return MCDisassembler::Success;
4665 }
4666 
4667 static DecodeStatus DecodeThumbAddSPReg(MCInst &Inst, uint16_t Insn,
4668                                         uint64_t Address,
4669                                         const MCDisassembler *Decoder) {
4670   DecodeStatus S = MCDisassembler::Success;
4671 
4672   if (Inst.getOpcode() == ARM::tADDrSP) {
4673     unsigned Rdm = fieldFromInstruction(Insn, 0, 3);
4674     Rdm |= fieldFromInstruction(Insn, 7, 1) << 3;
4675 
4676     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
4677     return MCDisassembler::Fail;
4678     Inst.addOperand(MCOperand::createReg(ARM::SP));
4679     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
4680     return MCDisassembler::Fail;
4681   } else if (Inst.getOpcode() == ARM::tADDspr) {
4682     unsigned Rm = fieldFromInstruction(Insn, 3, 4);
4683 
4684     Inst.addOperand(MCOperand::createReg(ARM::SP));
4685     Inst.addOperand(MCOperand::createReg(ARM::SP));
4686     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4687     return MCDisassembler::Fail;
4688   }
4689 
4690   return S;
4691 }
4692 
4693 static DecodeStatus DecodeThumbCPS(MCInst &Inst, uint16_t Insn,
4694                                    uint64_t Address,
4695                                    const MCDisassembler *Decoder) {
4696   unsigned imod = fieldFromInstruction(Insn, 4, 1) | 0x2;
4697   unsigned flags = fieldFromInstruction(Insn, 0, 3);
4698 
4699   Inst.addOperand(MCOperand::createImm(imod));
4700   Inst.addOperand(MCOperand::createImm(flags));
4701 
4702   return MCDisassembler::Success;
4703 }
4704 
4705 static DecodeStatus DecodePostIdxReg(MCInst &Inst, unsigned Insn,
4706                                      uint64_t Address,
4707                                      const MCDisassembler *Decoder) {
4708   DecodeStatus S = MCDisassembler::Success;
4709   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4710   unsigned add = fieldFromInstruction(Insn, 4, 1);
4711 
4712   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
4713     return MCDisassembler::Fail;
4714   Inst.addOperand(MCOperand::createImm(add));
4715 
4716   return S;
4717 }
4718 
4719 static DecodeStatus DecodeMveAddrModeRQ(MCInst &Inst, unsigned Insn,
4720                                         uint64_t Address,
4721                                         const MCDisassembler *Decoder) {
4722   DecodeStatus S = MCDisassembler::Success;
4723   unsigned Rn = fieldFromInstruction(Insn, 3, 4);
4724   unsigned Qm = fieldFromInstruction(Insn, 0, 3);
4725 
4726   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4727     return MCDisassembler::Fail;
4728   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
4729     return MCDisassembler::Fail;
4730 
4731   return S;
4732 }
4733 
4734 template <int shift>
4735 static DecodeStatus DecodeMveAddrModeQ(MCInst &Inst, unsigned Insn,
4736                                        uint64_t Address,
4737                                        const MCDisassembler *Decoder) {
4738   DecodeStatus S = MCDisassembler::Success;
4739   unsigned Qm = fieldFromInstruction(Insn, 8, 3);
4740   int imm = fieldFromInstruction(Insn, 0, 7);
4741 
4742   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
4743     return MCDisassembler::Fail;
4744 
4745   if(!fieldFromInstruction(Insn, 7, 1)) {
4746     if (imm == 0)
4747       imm = INT32_MIN;                 // indicate -0
4748     else
4749       imm *= -1;
4750   }
4751   if (imm != INT32_MIN)
4752     imm *= (1U << shift);
4753   Inst.addOperand(MCOperand::createImm(imm));
4754 
4755   return S;
4756 }
4757 
4758 static DecodeStatus DecodeThumbBLXOffset(MCInst &Inst, unsigned Val,
4759                                          uint64_t Address,
4760                                          const MCDisassembler *Decoder) {
4761   // Val is passed in as S:J1:J2:imm10H:imm10L:'0'
4762   // Note only one trailing zero not two.  Also the J1 and J2 values are from
4763   // the encoded instruction.  So here change to I1 and I2 values via:
4764   // I1 = NOT(J1 EOR S);
4765   // I2 = NOT(J2 EOR S);
4766   // and build the imm32 with two trailing zeros as documented:
4767   // imm32 = SignExtend(S:I1:I2:imm10H:imm10L:'00', 32);
4768   unsigned S = (Val >> 23) & 1;
4769   unsigned J1 = (Val >> 22) & 1;
4770   unsigned J2 = (Val >> 21) & 1;
4771   unsigned I1 = !(J1 ^ S);
4772   unsigned I2 = !(J2 ^ S);
4773   unsigned tmp = (Val & ~0x600000) | (I1 << 22) | (I2 << 21);
4774   int imm32 = SignExtend32<25>(tmp << 1);
4775 
4776   if (!tryAddingSymbolicOperand(Address,
4777                                 (Address & ~2u) + imm32 + 4,
4778                                 true, 4, Inst, Decoder))
4779     Inst.addOperand(MCOperand::createImm(imm32));
4780   return MCDisassembler::Success;
4781 }
4782 
4783 static DecodeStatus DecodeCoprocessor(MCInst &Inst, unsigned Val,
4784                                       uint64_t Address,
4785                                       const MCDisassembler *Decoder) {
4786   if (Val == 0xA || Val == 0xB)
4787     return MCDisassembler::Fail;
4788 
4789   const FeatureBitset &featureBits =
4790     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4791 
4792   if (!isValidCoprocessorNumber(Val, featureBits))
4793     return MCDisassembler::Fail;
4794 
4795   Inst.addOperand(MCOperand::createImm(Val));
4796   return MCDisassembler::Success;
4797 }
4798 
4799 static DecodeStatus DecodeThumbTableBranch(MCInst &Inst, unsigned Insn,
4800                                            uint64_t Address,
4801                                            const MCDisassembler *Decoder) {
4802   const FeatureBitset &FeatureBits =
4803     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4804   DecodeStatus S = MCDisassembler::Success;
4805 
4806   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4807   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4808 
4809   if (Rn == 13 && !FeatureBits[ARM::HasV8Ops]) S = MCDisassembler::SoftFail;
4810   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4811     return MCDisassembler::Fail;
4812   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
4813     return MCDisassembler::Fail;
4814   return S;
4815 }
4816 
4817 static DecodeStatus DecodeThumb2BCCInstruction(MCInst &Inst, unsigned Insn,
4818                                                uint64_t Address,
4819                                                const MCDisassembler *Decoder) {
4820   DecodeStatus S = MCDisassembler::Success;
4821 
4822   unsigned pred = fieldFromInstruction(Insn, 22, 4);
4823   if (pred == 0xE || pred == 0xF) {
4824     unsigned opc = fieldFromInstruction(Insn, 4, 28);
4825     switch (opc) {
4826       default:
4827         return MCDisassembler::Fail;
4828       case 0xf3bf8f4:
4829         Inst.setOpcode(ARM::t2DSB);
4830         break;
4831       case 0xf3bf8f5:
4832         Inst.setOpcode(ARM::t2DMB);
4833         break;
4834       case 0xf3bf8f6:
4835         Inst.setOpcode(ARM::t2ISB);
4836         break;
4837     }
4838 
4839     unsigned imm = fieldFromInstruction(Insn, 0, 4);
4840     return DecodeMemBarrierOption(Inst, imm, Address, Decoder);
4841   }
4842 
4843   unsigned brtarget = fieldFromInstruction(Insn, 0, 11) << 1;
4844   brtarget |= fieldFromInstruction(Insn, 11, 1) << 19;
4845   brtarget |= fieldFromInstruction(Insn, 13, 1) << 18;
4846   brtarget |= fieldFromInstruction(Insn, 16, 6) << 12;
4847   brtarget |= fieldFromInstruction(Insn, 26, 1) << 20;
4848 
4849   if (!Check(S, DecodeT2BROperand(Inst, brtarget, Address, Decoder)))
4850     return MCDisassembler::Fail;
4851   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4852     return MCDisassembler::Fail;
4853 
4854   return S;
4855 }
4856 
4857 // Decode a shifted immediate operand.  These basically consist
4858 // of an 8-bit value, and a 4-bit directive that specifies either
4859 // a splat operation or a rotation.
4860 static DecodeStatus DecodeT2SOImm(MCInst &Inst, unsigned Val, uint64_t Address,
4861                                   const MCDisassembler *Decoder) {
4862   unsigned ctrl = fieldFromInstruction(Val, 10, 2);
4863   if (ctrl == 0) {
4864     unsigned byte = fieldFromInstruction(Val, 8, 2);
4865     unsigned imm = fieldFromInstruction(Val, 0, 8);
4866     switch (byte) {
4867       case 0:
4868         Inst.addOperand(MCOperand::createImm(imm));
4869         break;
4870       case 1:
4871         Inst.addOperand(MCOperand::createImm((imm << 16) | imm));
4872         break;
4873       case 2:
4874         Inst.addOperand(MCOperand::createImm((imm << 24) | (imm << 8)));
4875         break;
4876       case 3:
4877         Inst.addOperand(MCOperand::createImm((imm << 24) | (imm << 16) |
4878                                              (imm << 8)  |  imm));
4879         break;
4880     }
4881   } else {
4882     unsigned unrot = fieldFromInstruction(Val, 0, 7) | 0x80;
4883     unsigned rot = fieldFromInstruction(Val, 7, 5);
4884     unsigned imm = (unrot >> rot) | (unrot << ((32-rot)&31));
4885     Inst.addOperand(MCOperand::createImm(imm));
4886   }
4887 
4888   return MCDisassembler::Success;
4889 }
4890 
4891 static DecodeStatus DecodeThumbBCCTargetOperand(MCInst &Inst, unsigned Val,
4892                                                 uint64_t Address,
4893                                                 const MCDisassembler *Decoder) {
4894   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<9>(Val<<1) + 4,
4895                                 true, 2, Inst, Decoder))
4896     Inst.addOperand(MCOperand::createImm(SignExtend32<9>(Val << 1)));
4897   return MCDisassembler::Success;
4898 }
4899 
4900 static DecodeStatus DecodeThumbBLTargetOperand(MCInst &Inst, unsigned Val,
4901                                                uint64_t Address,
4902                                                const MCDisassembler *Decoder) {
4903   // Val is passed in as S:J1:J2:imm10:imm11
4904   // Note no trailing zero after imm11.  Also the J1 and J2 values are from
4905   // the encoded instruction.  So here change to I1 and I2 values via:
4906   // I1 = NOT(J1 EOR S);
4907   // I2 = NOT(J2 EOR S);
4908   // and build the imm32 with one trailing zero as documented:
4909   // imm32 = SignExtend(S:I1:I2:imm10:imm11:'0', 32);
4910   unsigned S = (Val >> 23) & 1;
4911   unsigned J1 = (Val >> 22) & 1;
4912   unsigned J2 = (Val >> 21) & 1;
4913   unsigned I1 = !(J1 ^ S);
4914   unsigned I2 = !(J2 ^ S);
4915   unsigned tmp = (Val & ~0x600000) | (I1 << 22) | (I2 << 21);
4916   int imm32 = SignExtend32<25>(tmp << 1);
4917 
4918   if (!tryAddingSymbolicOperand(Address, Address + imm32 + 4,
4919                                 true, 4, Inst, Decoder))
4920     Inst.addOperand(MCOperand::createImm(imm32));
4921   return MCDisassembler::Success;
4922 }
4923 
4924 static DecodeStatus DecodeMemBarrierOption(MCInst &Inst, unsigned Val,
4925                                            uint64_t Address,
4926                                            const MCDisassembler *Decoder) {
4927   if (Val & ~0xf)
4928     return MCDisassembler::Fail;
4929 
4930   Inst.addOperand(MCOperand::createImm(Val));
4931   return MCDisassembler::Success;
4932 }
4933 
4934 static DecodeStatus DecodeInstSyncBarrierOption(MCInst &Inst, unsigned Val,
4935                                                 uint64_t Address,
4936                                                 const MCDisassembler *Decoder) {
4937   if (Val & ~0xf)
4938     return MCDisassembler::Fail;
4939 
4940   Inst.addOperand(MCOperand::createImm(Val));
4941   return MCDisassembler::Success;
4942 }
4943 
4944 static DecodeStatus DecodeMSRMask(MCInst &Inst, unsigned Val, uint64_t Address,
4945                                   const MCDisassembler *Decoder) {
4946   DecodeStatus S = MCDisassembler::Success;
4947   const FeatureBitset &FeatureBits =
4948     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4949 
4950   if (FeatureBits[ARM::FeatureMClass]) {
4951     unsigned ValLow = Val & 0xff;
4952 
4953     // Validate the SYSm value first.
4954     switch (ValLow) {
4955     case  0: // apsr
4956     case  1: // iapsr
4957     case  2: // eapsr
4958     case  3: // xpsr
4959     case  5: // ipsr
4960     case  6: // epsr
4961     case  7: // iepsr
4962     case  8: // msp
4963     case  9: // psp
4964     case 16: // primask
4965     case 20: // control
4966       break;
4967     case 17: // basepri
4968     case 18: // basepri_max
4969     case 19: // faultmask
4970       if (!(FeatureBits[ARM::HasV7Ops]))
4971         // Values basepri, basepri_max and faultmask are only valid for v7m.
4972         return MCDisassembler::Fail;
4973       break;
4974     case 0x8a: // msplim_ns
4975     case 0x8b: // psplim_ns
4976     case 0x91: // basepri_ns
4977     case 0x93: // faultmask_ns
4978       if (!(FeatureBits[ARM::HasV8MMainlineOps]))
4979         return MCDisassembler::Fail;
4980       LLVM_FALLTHROUGH;
4981     case 10:   // msplim
4982     case 11:   // psplim
4983     case 0x88: // msp_ns
4984     case 0x89: // psp_ns
4985     case 0x90: // primask_ns
4986     case 0x94: // control_ns
4987     case 0x98: // sp_ns
4988       if (!(FeatureBits[ARM::Feature8MSecExt]))
4989         return MCDisassembler::Fail;
4990       break;
4991     case 0x20: // pac_key_p_0
4992     case 0x21: // pac_key_p_1
4993     case 0x22: // pac_key_p_2
4994     case 0x23: // pac_key_p_3
4995     case 0x24: // pac_key_u_0
4996     case 0x25: // pac_key_u_1
4997     case 0x26: // pac_key_u_2
4998     case 0x27: // pac_key_u_3
4999     case 0xa0: // pac_key_p_0_ns
5000     case 0xa1: // pac_key_p_1_ns
5001     case 0xa2: // pac_key_p_2_ns
5002     case 0xa3: // pac_key_p_3_ns
5003     case 0xa4: // pac_key_u_0_ns
5004     case 0xa5: // pac_key_u_1_ns
5005     case 0xa6: // pac_key_u_2_ns
5006     case 0xa7: // pac_key_u_3_ns
5007       if (!(FeatureBits[ARM::FeaturePACBTI]))
5008         return MCDisassembler::Fail;
5009       break;
5010     default:
5011       // Architecturally defined as unpredictable
5012       S = MCDisassembler::SoftFail;
5013       break;
5014     }
5015 
5016     if (Inst.getOpcode() == ARM::t2MSR_M) {
5017       unsigned Mask = fieldFromInstruction(Val, 10, 2);
5018       if (!(FeatureBits[ARM::HasV7Ops])) {
5019         // The ARMv6-M MSR bits {11-10} can be only 0b10, other values are
5020         // unpredictable.
5021         if (Mask != 2)
5022           S = MCDisassembler::SoftFail;
5023       }
5024       else {
5025         // The ARMv7-M architecture stores an additional 2-bit mask value in
5026         // MSR bits {11-10}. The mask is used only with apsr, iapsr, eapsr and
5027         // xpsr, it has to be 0b10 in other cases. Bit mask{1} indicates if
5028         // the NZCVQ bits should be moved by the instruction. Bit mask{0}
5029         // indicates the move for the GE{3:0} bits, the mask{0} bit can be set
5030         // only if the processor includes the DSP extension.
5031         if (Mask == 0 || (Mask != 2 && ValLow > 3) ||
5032             (!(FeatureBits[ARM::FeatureDSP]) && (Mask & 1)))
5033           S = MCDisassembler::SoftFail;
5034       }
5035     }
5036   } else {
5037     // A/R class
5038     if (Val == 0)
5039       return MCDisassembler::Fail;
5040   }
5041   Inst.addOperand(MCOperand::createImm(Val));
5042   return S;
5043 }
5044 
5045 static DecodeStatus DecodeBankedReg(MCInst &Inst, unsigned Val,
5046                                     uint64_t Address,
5047                                     const MCDisassembler *Decoder) {
5048   unsigned R = fieldFromInstruction(Val, 5, 1);
5049   unsigned SysM = fieldFromInstruction(Val, 0, 5);
5050 
5051   // The table of encodings for these banked registers comes from B9.2.3 of the
5052   // ARM ARM. There are patterns, but nothing regular enough to make this logic
5053   // neater. So by fiat, these values are UNPREDICTABLE:
5054   if (!ARMBankedReg::lookupBankedRegByEncoding((R << 5) | SysM))
5055     return MCDisassembler::Fail;
5056 
5057   Inst.addOperand(MCOperand::createImm(Val));
5058   return MCDisassembler::Success;
5059 }
5060 
5061 static DecodeStatus DecodeDoubleRegLoad(MCInst &Inst, unsigned Insn,
5062                                         uint64_t Address,
5063                                         const MCDisassembler *Decoder) {
5064   DecodeStatus S = MCDisassembler::Success;
5065 
5066   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5067   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5068   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5069 
5070   if (Rn == 0xF)
5071     S = MCDisassembler::SoftFail;
5072 
5073   if (!Check(S, DecodeGPRPairRegisterClass(Inst, Rt, Address, Decoder)))
5074     return MCDisassembler::Fail;
5075   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5076     return MCDisassembler::Fail;
5077   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5078     return MCDisassembler::Fail;
5079 
5080   return S;
5081 }
5082 
5083 static DecodeStatus DecodeDoubleRegStore(MCInst &Inst, unsigned Insn,
5084                                          uint64_t Address,
5085                                          const MCDisassembler *Decoder) {
5086   DecodeStatus S = MCDisassembler::Success;
5087 
5088   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5089   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
5090   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5091   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5092 
5093   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
5094     return MCDisassembler::Fail;
5095 
5096   if (Rn == 0xF || Rd == Rn || Rd == Rt || Rd == Rt+1)
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 DecodeLDRPreImm(MCInst &Inst, unsigned Insn,
5110                                     uint64_t Address,
5111                                     const MCDisassembler *Decoder) {
5112   DecodeStatus S = MCDisassembler::Success;
5113 
5114   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5115   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5116   unsigned imm = fieldFromInstruction(Insn, 0, 12);
5117   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
5118   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
5119   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5120 
5121   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
5122 
5123   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
5124     return MCDisassembler::Fail;
5125   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5126     return MCDisassembler::Fail;
5127   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, 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 DecodeLDRPreReg(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   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5147 
5148   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
5149   if (Rm == 0xF) S = MCDisassembler::SoftFail;
5150 
5151   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
5152     return MCDisassembler::Fail;
5153   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5154     return MCDisassembler::Fail;
5155   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
5156     return MCDisassembler::Fail;
5157   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5158     return MCDisassembler::Fail;
5159 
5160   return S;
5161 }
5162 
5163 static DecodeStatus DecodeSTRPreImm(MCInst &Inst, unsigned Insn,
5164                                     uint64_t Address,
5165                                     const MCDisassembler *Decoder) {
5166   DecodeStatus S = MCDisassembler::Success;
5167 
5168   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5169   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5170   unsigned imm = fieldFromInstruction(Insn, 0, 12);
5171   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
5172   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
5173   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5174 
5175   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
5176 
5177   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5178     return MCDisassembler::Fail;
5179   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
5180     return MCDisassembler::Fail;
5181   if (!Check(S, DecodeAddrModeImm12Operand(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 DecodeSTRPreReg(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, DecodeSORegMemOperand(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 DecodeVLD1LN(MCInst &Inst, unsigned Insn, uint64_t Address,
5216                                  const MCDisassembler *Decoder) {
5217   DecodeStatus S = MCDisassembler::Success;
5218 
5219   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5220   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5221   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5222   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5223   unsigned size = fieldFromInstruction(Insn, 10, 2);
5224 
5225   unsigned align = 0;
5226   unsigned index = 0;
5227   switch (size) {
5228     default:
5229       return MCDisassembler::Fail;
5230     case 0:
5231       if (fieldFromInstruction(Insn, 4, 1))
5232         return MCDisassembler::Fail; // UNDEFINED
5233       index = fieldFromInstruction(Insn, 5, 3);
5234       break;
5235     case 1:
5236       if (fieldFromInstruction(Insn, 5, 1))
5237         return MCDisassembler::Fail; // UNDEFINED
5238       index = fieldFromInstruction(Insn, 6, 2);
5239       if (fieldFromInstruction(Insn, 4, 1))
5240         align = 2;
5241       break;
5242     case 2:
5243       if (fieldFromInstruction(Insn, 6, 1))
5244         return MCDisassembler::Fail; // UNDEFINED
5245       index = fieldFromInstruction(Insn, 7, 1);
5246 
5247       switch (fieldFromInstruction(Insn, 4, 2)) {
5248         case 0 :
5249           align = 0; break;
5250         case 3:
5251           align = 4; break;
5252         default:
5253           return MCDisassembler::Fail;
5254       }
5255       break;
5256   }
5257 
5258   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5259     return MCDisassembler::Fail;
5260   if (Rm != 0xF) { // Writeback
5261     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5262       return MCDisassembler::Fail;
5263   }
5264   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5265     return MCDisassembler::Fail;
5266   Inst.addOperand(MCOperand::createImm(align));
5267   if (Rm != 0xF) {
5268     if (Rm != 0xD) {
5269       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5270         return MCDisassembler::Fail;
5271     } else
5272       Inst.addOperand(MCOperand::createReg(0));
5273   }
5274 
5275   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5276     return MCDisassembler::Fail;
5277   Inst.addOperand(MCOperand::createImm(index));
5278 
5279   return S;
5280 }
5281 
5282 static DecodeStatus DecodeVST1LN(MCInst &Inst, unsigned Insn, uint64_t Address,
5283                                  const MCDisassembler *Decoder) {
5284   DecodeStatus S = MCDisassembler::Success;
5285 
5286   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5287   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5288   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5289   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5290   unsigned size = fieldFromInstruction(Insn, 10, 2);
5291 
5292   unsigned align = 0;
5293   unsigned index = 0;
5294   switch (size) {
5295     default:
5296       return MCDisassembler::Fail;
5297     case 0:
5298       if (fieldFromInstruction(Insn, 4, 1))
5299         return MCDisassembler::Fail; // UNDEFINED
5300       index = fieldFromInstruction(Insn, 5, 3);
5301       break;
5302     case 1:
5303       if (fieldFromInstruction(Insn, 5, 1))
5304         return MCDisassembler::Fail; // UNDEFINED
5305       index = fieldFromInstruction(Insn, 6, 2);
5306       if (fieldFromInstruction(Insn, 4, 1))
5307         align = 2;
5308       break;
5309     case 2:
5310       if (fieldFromInstruction(Insn, 6, 1))
5311         return MCDisassembler::Fail; // UNDEFINED
5312       index = fieldFromInstruction(Insn, 7, 1);
5313 
5314       switch (fieldFromInstruction(Insn, 4, 2)) {
5315         case 0:
5316           align = 0; break;
5317         case 3:
5318           align = 4; break;
5319         default:
5320           return MCDisassembler::Fail;
5321       }
5322       break;
5323   }
5324 
5325   if (Rm != 0xF) { // Writeback
5326     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5327     return MCDisassembler::Fail;
5328   }
5329   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5330     return MCDisassembler::Fail;
5331   Inst.addOperand(MCOperand::createImm(align));
5332   if (Rm != 0xF) {
5333     if (Rm != 0xD) {
5334       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5335     return MCDisassembler::Fail;
5336     } else
5337       Inst.addOperand(MCOperand::createReg(0));
5338   }
5339 
5340   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5341     return MCDisassembler::Fail;
5342   Inst.addOperand(MCOperand::createImm(index));
5343 
5344   return S;
5345 }
5346 
5347 static DecodeStatus DecodeVLD2LN(MCInst &Inst, unsigned Insn, uint64_t Address,
5348                                  const MCDisassembler *Decoder) {
5349   DecodeStatus S = MCDisassembler::Success;
5350 
5351   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5352   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5353   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5354   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5355   unsigned size = fieldFromInstruction(Insn, 10, 2);
5356 
5357   unsigned align = 0;
5358   unsigned index = 0;
5359   unsigned inc = 1;
5360   switch (size) {
5361     default:
5362       return MCDisassembler::Fail;
5363     case 0:
5364       index = fieldFromInstruction(Insn, 5, 3);
5365       if (fieldFromInstruction(Insn, 4, 1))
5366         align = 2;
5367       break;
5368     case 1:
5369       index = fieldFromInstruction(Insn, 6, 2);
5370       if (fieldFromInstruction(Insn, 4, 1))
5371         align = 4;
5372       if (fieldFromInstruction(Insn, 5, 1))
5373         inc = 2;
5374       break;
5375     case 2:
5376       if (fieldFromInstruction(Insn, 5, 1))
5377         return MCDisassembler::Fail; // UNDEFINED
5378       index = fieldFromInstruction(Insn, 7, 1);
5379       if (fieldFromInstruction(Insn, 4, 1) != 0)
5380         align = 8;
5381       if (fieldFromInstruction(Insn, 6, 1))
5382         inc = 2;
5383       break;
5384   }
5385 
5386   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5387     return MCDisassembler::Fail;
5388   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5389     return MCDisassembler::Fail;
5390   if (Rm != 0xF) { // Writeback
5391     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5392       return MCDisassembler::Fail;
5393   }
5394   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5395     return MCDisassembler::Fail;
5396   Inst.addOperand(MCOperand::createImm(align));
5397   if (Rm != 0xF) {
5398     if (Rm != 0xD) {
5399       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5400         return MCDisassembler::Fail;
5401     } else
5402       Inst.addOperand(MCOperand::createReg(0));
5403   }
5404 
5405   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5406     return MCDisassembler::Fail;
5407   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5408     return MCDisassembler::Fail;
5409   Inst.addOperand(MCOperand::createImm(index));
5410 
5411   return S;
5412 }
5413 
5414 static DecodeStatus DecodeVST2LN(MCInst &Inst, unsigned Insn, uint64_t Address,
5415                                  const MCDisassembler *Decoder) {
5416   DecodeStatus S = MCDisassembler::Success;
5417 
5418   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5419   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5420   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5421   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5422   unsigned size = fieldFromInstruction(Insn, 10, 2);
5423 
5424   unsigned align = 0;
5425   unsigned index = 0;
5426   unsigned inc = 1;
5427   switch (size) {
5428     default:
5429       return MCDisassembler::Fail;
5430     case 0:
5431       index = fieldFromInstruction(Insn, 5, 3);
5432       if (fieldFromInstruction(Insn, 4, 1))
5433         align = 2;
5434       break;
5435     case 1:
5436       index = fieldFromInstruction(Insn, 6, 2);
5437       if (fieldFromInstruction(Insn, 4, 1))
5438         align = 4;
5439       if (fieldFromInstruction(Insn, 5, 1))
5440         inc = 2;
5441       break;
5442     case 2:
5443       if (fieldFromInstruction(Insn, 5, 1))
5444         return MCDisassembler::Fail; // UNDEFINED
5445       index = fieldFromInstruction(Insn, 7, 1);
5446       if (fieldFromInstruction(Insn, 4, 1) != 0)
5447         align = 8;
5448       if (fieldFromInstruction(Insn, 6, 1))
5449         inc = 2;
5450       break;
5451   }
5452 
5453   if (Rm != 0xF) { // Writeback
5454     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5455       return MCDisassembler::Fail;
5456   }
5457   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5458     return MCDisassembler::Fail;
5459   Inst.addOperand(MCOperand::createImm(align));
5460   if (Rm != 0xF) {
5461     if (Rm != 0xD) {
5462       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5463         return MCDisassembler::Fail;
5464     } else
5465       Inst.addOperand(MCOperand::createReg(0));
5466   }
5467 
5468   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5469     return MCDisassembler::Fail;
5470   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5471     return MCDisassembler::Fail;
5472   Inst.addOperand(MCOperand::createImm(index));
5473 
5474   return S;
5475 }
5476 
5477 static DecodeStatus DecodeVLD3LN(MCInst &Inst, unsigned Insn, uint64_t Address,
5478                                  const MCDisassembler *Decoder) {
5479   DecodeStatus S = MCDisassembler::Success;
5480 
5481   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5482   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5483   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5484   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5485   unsigned size = fieldFromInstruction(Insn, 10, 2);
5486 
5487   unsigned align = 0;
5488   unsigned index = 0;
5489   unsigned inc = 1;
5490   switch (size) {
5491     default:
5492       return MCDisassembler::Fail;
5493     case 0:
5494       if (fieldFromInstruction(Insn, 4, 1))
5495         return MCDisassembler::Fail; // UNDEFINED
5496       index = fieldFromInstruction(Insn, 5, 3);
5497       break;
5498     case 1:
5499       if (fieldFromInstruction(Insn, 4, 1))
5500         return MCDisassembler::Fail; // UNDEFINED
5501       index = fieldFromInstruction(Insn, 6, 2);
5502       if (fieldFromInstruction(Insn, 5, 1))
5503         inc = 2;
5504       break;
5505     case 2:
5506       if (fieldFromInstruction(Insn, 4, 2))
5507         return MCDisassembler::Fail; // UNDEFINED
5508       index = fieldFromInstruction(Insn, 7, 1);
5509       if (fieldFromInstruction(Insn, 6, 1))
5510         inc = 2;
5511       break;
5512   }
5513 
5514   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5515     return MCDisassembler::Fail;
5516   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5517     return MCDisassembler::Fail;
5518   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5519     return MCDisassembler::Fail;
5520 
5521   if (Rm != 0xF) { // Writeback
5522     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5523     return MCDisassembler::Fail;
5524   }
5525   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5526     return MCDisassembler::Fail;
5527   Inst.addOperand(MCOperand::createImm(align));
5528   if (Rm != 0xF) {
5529     if (Rm != 0xD) {
5530       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5531     return MCDisassembler::Fail;
5532     } else
5533       Inst.addOperand(MCOperand::createReg(0));
5534   }
5535 
5536   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5537     return MCDisassembler::Fail;
5538   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5539     return MCDisassembler::Fail;
5540   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5541     return MCDisassembler::Fail;
5542   Inst.addOperand(MCOperand::createImm(index));
5543 
5544   return S;
5545 }
5546 
5547 static DecodeStatus DecodeVST3LN(MCInst &Inst, unsigned Insn, uint64_t Address,
5548                                  const MCDisassembler *Decoder) {
5549   DecodeStatus S = MCDisassembler::Success;
5550 
5551   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5552   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5553   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5554   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5555   unsigned size = fieldFromInstruction(Insn, 10, 2);
5556 
5557   unsigned align = 0;
5558   unsigned index = 0;
5559   unsigned inc = 1;
5560   switch (size) {
5561     default:
5562       return MCDisassembler::Fail;
5563     case 0:
5564       if (fieldFromInstruction(Insn, 4, 1))
5565         return MCDisassembler::Fail; // UNDEFINED
5566       index = fieldFromInstruction(Insn, 5, 3);
5567       break;
5568     case 1:
5569       if (fieldFromInstruction(Insn, 4, 1))
5570         return MCDisassembler::Fail; // UNDEFINED
5571       index = fieldFromInstruction(Insn, 6, 2);
5572       if (fieldFromInstruction(Insn, 5, 1))
5573         inc = 2;
5574       break;
5575     case 2:
5576       if (fieldFromInstruction(Insn, 4, 2))
5577         return MCDisassembler::Fail; // UNDEFINED
5578       index = fieldFromInstruction(Insn, 7, 1);
5579       if (fieldFromInstruction(Insn, 6, 1))
5580         inc = 2;
5581       break;
5582   }
5583 
5584   if (Rm != 0xF) { // Writeback
5585     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5586     return MCDisassembler::Fail;
5587   }
5588   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5589     return MCDisassembler::Fail;
5590   Inst.addOperand(MCOperand::createImm(align));
5591   if (Rm != 0xF) {
5592     if (Rm != 0xD) {
5593       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5594     return MCDisassembler::Fail;
5595     } else
5596       Inst.addOperand(MCOperand::createReg(0));
5597   }
5598 
5599   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5600     return MCDisassembler::Fail;
5601   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5602     return MCDisassembler::Fail;
5603   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5604     return MCDisassembler::Fail;
5605   Inst.addOperand(MCOperand::createImm(index));
5606 
5607   return S;
5608 }
5609 
5610 static DecodeStatus DecodeVLD4LN(MCInst &Inst, unsigned Insn, uint64_t Address,
5611                                  const MCDisassembler *Decoder) {
5612   DecodeStatus S = MCDisassembler::Success;
5613 
5614   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5615   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5616   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5617   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5618   unsigned size = fieldFromInstruction(Insn, 10, 2);
5619 
5620   unsigned align = 0;
5621   unsigned index = 0;
5622   unsigned inc = 1;
5623   switch (size) {
5624     default:
5625       return MCDisassembler::Fail;
5626     case 0:
5627       if (fieldFromInstruction(Insn, 4, 1))
5628         align = 4;
5629       index = fieldFromInstruction(Insn, 5, 3);
5630       break;
5631     case 1:
5632       if (fieldFromInstruction(Insn, 4, 1))
5633         align = 8;
5634       index = fieldFromInstruction(Insn, 6, 2);
5635       if (fieldFromInstruction(Insn, 5, 1))
5636         inc = 2;
5637       break;
5638     case 2:
5639       switch (fieldFromInstruction(Insn, 4, 2)) {
5640         case 0:
5641           align = 0; break;
5642         case 3:
5643           return MCDisassembler::Fail;
5644         default:
5645           align = 4 << fieldFromInstruction(Insn, 4, 2); break;
5646       }
5647 
5648       index = fieldFromInstruction(Insn, 7, 1);
5649       if (fieldFromInstruction(Insn, 6, 1))
5650         inc = 2;
5651       break;
5652   }
5653 
5654   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5655     return MCDisassembler::Fail;
5656   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5657     return MCDisassembler::Fail;
5658   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5659     return MCDisassembler::Fail;
5660   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5661     return MCDisassembler::Fail;
5662 
5663   if (Rm != 0xF) { // Writeback
5664     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5665       return MCDisassembler::Fail;
5666   }
5667   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5668     return MCDisassembler::Fail;
5669   Inst.addOperand(MCOperand::createImm(align));
5670   if (Rm != 0xF) {
5671     if (Rm != 0xD) {
5672       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5673         return MCDisassembler::Fail;
5674     } else
5675       Inst.addOperand(MCOperand::createReg(0));
5676   }
5677 
5678   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5679     return MCDisassembler::Fail;
5680   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5681     return MCDisassembler::Fail;
5682   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5683     return MCDisassembler::Fail;
5684   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5685     return MCDisassembler::Fail;
5686   Inst.addOperand(MCOperand::createImm(index));
5687 
5688   return S;
5689 }
5690 
5691 static DecodeStatus DecodeVST4LN(MCInst &Inst, unsigned Insn, uint64_t Address,
5692                                  const MCDisassembler *Decoder) {
5693   DecodeStatus S = MCDisassembler::Success;
5694 
5695   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5696   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5697   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5698   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5699   unsigned size = fieldFromInstruction(Insn, 10, 2);
5700 
5701   unsigned align = 0;
5702   unsigned index = 0;
5703   unsigned inc = 1;
5704   switch (size) {
5705     default:
5706       return MCDisassembler::Fail;
5707     case 0:
5708       if (fieldFromInstruction(Insn, 4, 1))
5709         align = 4;
5710       index = fieldFromInstruction(Insn, 5, 3);
5711       break;
5712     case 1:
5713       if (fieldFromInstruction(Insn, 4, 1))
5714         align = 8;
5715       index = fieldFromInstruction(Insn, 6, 2);
5716       if (fieldFromInstruction(Insn, 5, 1))
5717         inc = 2;
5718       break;
5719     case 2:
5720       switch (fieldFromInstruction(Insn, 4, 2)) {
5721         case 0:
5722           align = 0; break;
5723         case 3:
5724           return MCDisassembler::Fail;
5725         default:
5726           align = 4 << fieldFromInstruction(Insn, 4, 2); break;
5727       }
5728 
5729       index = fieldFromInstruction(Insn, 7, 1);
5730       if (fieldFromInstruction(Insn, 6, 1))
5731         inc = 2;
5732       break;
5733   }
5734 
5735   if (Rm != 0xF) { // Writeback
5736     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5737     return MCDisassembler::Fail;
5738   }
5739   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5740     return MCDisassembler::Fail;
5741   Inst.addOperand(MCOperand::createImm(align));
5742   if (Rm != 0xF) {
5743     if (Rm != 0xD) {
5744       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5745     return MCDisassembler::Fail;
5746     } else
5747       Inst.addOperand(MCOperand::createReg(0));
5748   }
5749 
5750   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5751     return MCDisassembler::Fail;
5752   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5753     return MCDisassembler::Fail;
5754   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5755     return MCDisassembler::Fail;
5756   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5757     return MCDisassembler::Fail;
5758   Inst.addOperand(MCOperand::createImm(index));
5759 
5760   return S;
5761 }
5762 
5763 static DecodeStatus DecodeVMOVSRR(MCInst &Inst, unsigned Insn, uint64_t Address,
5764                                   const MCDisassembler *Decoder) {
5765   DecodeStatus S = MCDisassembler::Success;
5766   unsigned Rt  = fieldFromInstruction(Insn, 12, 4);
5767   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
5768   unsigned Rm  = fieldFromInstruction(Insn,  5, 1);
5769   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5770   Rm |= fieldFromInstruction(Insn, 0, 4) << 1;
5771 
5772   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
5773     S = MCDisassembler::SoftFail;
5774 
5775   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
5776     return MCDisassembler::Fail;
5777   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
5778     return MCDisassembler::Fail;
5779   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
5780     return MCDisassembler::Fail;
5781   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
5782     return MCDisassembler::Fail;
5783   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5784     return MCDisassembler::Fail;
5785 
5786   return S;
5787 }
5788 
5789 static DecodeStatus DecodeVMOVRRS(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, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
5802     return MCDisassembler::Fail;
5803   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
5804     return MCDisassembler::Fail;
5805   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
5806     return MCDisassembler::Fail;
5807   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
5808     return MCDisassembler::Fail;
5809   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5810     return MCDisassembler::Fail;
5811 
5812   return S;
5813 }
5814 
5815 static DecodeStatus DecodeIT(MCInst &Inst, unsigned Insn, uint64_t Address,
5816                              const MCDisassembler *Decoder) {
5817   DecodeStatus S = MCDisassembler::Success;
5818   unsigned pred = fieldFromInstruction(Insn, 4, 4);
5819   unsigned mask = fieldFromInstruction(Insn, 0, 4);
5820 
5821   if (pred == 0xF) {
5822     pred = 0xE;
5823     S = MCDisassembler::SoftFail;
5824   }
5825 
5826   if (mask == 0x0)
5827     return MCDisassembler::Fail;
5828 
5829   // IT masks are encoded as a sequence of replacement low-order bits
5830   // for the condition code. So if the low bit of the starting
5831   // condition code is 1, then we have to flip all the bits above the
5832   // terminating bit (which is the lowest 1 bit).
5833   if (pred & 1) {
5834     unsigned LowBit = mask & -mask;
5835     unsigned BitsAboveLowBit = 0xF & (-LowBit << 1);
5836     mask ^= BitsAboveLowBit;
5837   }
5838 
5839   Inst.addOperand(MCOperand::createImm(pred));
5840   Inst.addOperand(MCOperand::createImm(mask));
5841   return S;
5842 }
5843 
5844 static DecodeStatus DecodeT2LDRDPreInstruction(MCInst &Inst, unsigned Insn,
5845                                                uint64_t Address,
5846                                                const MCDisassembler *Decoder) {
5847   DecodeStatus S = MCDisassembler::Success;
5848 
5849   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5850   unsigned Rt2 = fieldFromInstruction(Insn, 8, 4);
5851   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5852   unsigned addr = fieldFromInstruction(Insn, 0, 8);
5853   unsigned W = fieldFromInstruction(Insn, 21, 1);
5854   unsigned U = fieldFromInstruction(Insn, 23, 1);
5855   unsigned P = fieldFromInstruction(Insn, 24, 1);
5856   bool writeback = (W == 1) | (P == 0);
5857 
5858   addr |= (U << 8) | (Rn << 9);
5859 
5860   if (writeback && (Rn == Rt || Rn == Rt2))
5861     Check(S, MCDisassembler::SoftFail);
5862   if (Rt == Rt2)
5863     Check(S, MCDisassembler::SoftFail);
5864 
5865   // Rt
5866   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
5867     return MCDisassembler::Fail;
5868   // Rt2
5869   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
5870     return MCDisassembler::Fail;
5871   // Writeback operand
5872   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
5873     return MCDisassembler::Fail;
5874   // addr
5875   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
5876     return MCDisassembler::Fail;
5877 
5878   return S;
5879 }
5880 
5881 static DecodeStatus DecodeT2STRDPreInstruction(MCInst &Inst, unsigned Insn,
5882                                                uint64_t Address,
5883                                                const MCDisassembler *Decoder) {
5884   DecodeStatus S = MCDisassembler::Success;
5885 
5886   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5887   unsigned Rt2 = fieldFromInstruction(Insn, 8, 4);
5888   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5889   unsigned addr = fieldFromInstruction(Insn, 0, 8);
5890   unsigned W = fieldFromInstruction(Insn, 21, 1);
5891   unsigned U = fieldFromInstruction(Insn, 23, 1);
5892   unsigned P = fieldFromInstruction(Insn, 24, 1);
5893   bool writeback = (W == 1) | (P == 0);
5894 
5895   addr |= (U << 8) | (Rn << 9);
5896 
5897   if (writeback && (Rn == Rt || Rn == Rt2))
5898     Check(S, MCDisassembler::SoftFail);
5899 
5900   // Writeback operand
5901   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
5902     return MCDisassembler::Fail;
5903   // Rt
5904   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
5905     return MCDisassembler::Fail;
5906   // Rt2
5907   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
5908     return MCDisassembler::Fail;
5909   // addr
5910   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
5911     return MCDisassembler::Fail;
5912 
5913   return S;
5914 }
5915 
5916 static DecodeStatus DecodeT2Adr(MCInst &Inst, uint32_t Insn, uint64_t Address,
5917                                 const MCDisassembler *Decoder) {
5918   unsigned sign1 = fieldFromInstruction(Insn, 21, 1);
5919   unsigned sign2 = fieldFromInstruction(Insn, 23, 1);
5920   if (sign1 != sign2) return MCDisassembler::Fail;
5921   const unsigned Rd = fieldFromInstruction(Insn, 8, 4);
5922   assert(Inst.getNumOperands() == 0 && "We should receive an empty Inst");
5923   DecodeStatus S = DecoderGPRRegisterClass(Inst, Rd, Address, Decoder);
5924 
5925   unsigned Val = fieldFromInstruction(Insn, 0, 8);
5926   Val |= fieldFromInstruction(Insn, 12, 3) << 8;
5927   Val |= fieldFromInstruction(Insn, 26, 1) << 11;
5928   // If sign, then it is decreasing the address.
5929   if (sign1) {
5930     // Following ARMv7 Architecture Manual, when the offset
5931     // is zero, it is decoded as a subw, not as a adr.w
5932     if (!Val) {
5933       Inst.setOpcode(ARM::t2SUBri12);
5934       Inst.addOperand(MCOperand::createReg(ARM::PC));
5935     } else
5936       Val = -Val;
5937   }
5938   Inst.addOperand(MCOperand::createImm(Val));
5939   return S;
5940 }
5941 
5942 static DecodeStatus DecodeT2ShifterImmOperand(MCInst &Inst, uint32_t Val,
5943                                               uint64_t Address,
5944                                               const MCDisassembler *Decoder) {
5945   DecodeStatus S = MCDisassembler::Success;
5946 
5947   // Shift of "asr #32" is not allowed in Thumb2 mode.
5948   if (Val == 0x20) S = MCDisassembler::Fail;
5949   Inst.addOperand(MCOperand::createImm(Val));
5950   return S;
5951 }
5952 
5953 static DecodeStatus DecodeSwap(MCInst &Inst, unsigned Insn, uint64_t Address,
5954                                const MCDisassembler *Decoder) {
5955   unsigned Rt   = fieldFromInstruction(Insn, 12, 4);
5956   unsigned Rt2  = fieldFromInstruction(Insn, 0,  4);
5957   unsigned Rn   = fieldFromInstruction(Insn, 16, 4);
5958   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5959 
5960   if (pred == 0xF)
5961     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
5962 
5963   DecodeStatus S = MCDisassembler::Success;
5964 
5965   if (Rt == Rn || Rn == Rt2)
5966     S = MCDisassembler::SoftFail;
5967 
5968   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5969     return MCDisassembler::Fail;
5970   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5971     return MCDisassembler::Fail;
5972   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
5973     return MCDisassembler::Fail;
5974   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5975     return MCDisassembler::Fail;
5976 
5977   return S;
5978 }
5979 
5980 static DecodeStatus DecodeVCVTD(MCInst &Inst, unsigned Insn, uint64_t Address,
5981                                 const MCDisassembler *Decoder) {
5982   const FeatureBitset &featureBits =
5983       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5984   bool hasFullFP16 = featureBits[ARM::FeatureFullFP16];
5985 
5986   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5987   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5988   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5989   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5990   unsigned imm = fieldFromInstruction(Insn, 16, 6);
5991   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
5992   unsigned op = fieldFromInstruction(Insn, 5, 1);
5993 
5994   DecodeStatus S = MCDisassembler::Success;
5995 
5996   // If the top 3 bits of imm are clear, this is a VMOV (immediate)
5997   if (!(imm & 0x38)) {
5998     if (cmode == 0xF) {
5999       if (op == 1) return MCDisassembler::Fail;
6000       Inst.setOpcode(ARM::VMOVv2f32);
6001     }
6002     if (hasFullFP16) {
6003       if (cmode == 0xE) {
6004         if (op == 1) {
6005           Inst.setOpcode(ARM::VMOVv1i64);
6006         } else {
6007           Inst.setOpcode(ARM::VMOVv8i8);
6008         }
6009       }
6010       if (cmode == 0xD) {
6011         if (op == 1) {
6012           Inst.setOpcode(ARM::VMVNv2i32);
6013         } else {
6014           Inst.setOpcode(ARM::VMOVv2i32);
6015         }
6016       }
6017       if (cmode == 0xC) {
6018         if (op == 1) {
6019           Inst.setOpcode(ARM::VMVNv2i32);
6020         } else {
6021           Inst.setOpcode(ARM::VMOVv2i32);
6022         }
6023       }
6024     }
6025     return DecodeVMOVModImmInstruction(Inst, Insn, Address, Decoder);
6026   }
6027 
6028   if (!(imm & 0x20)) return MCDisassembler::Fail;
6029 
6030   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
6031     return MCDisassembler::Fail;
6032   if (!Check(S, DecodeDPRRegisterClass(Inst, Vm, Address, Decoder)))
6033     return MCDisassembler::Fail;
6034   Inst.addOperand(MCOperand::createImm(64 - imm));
6035 
6036   return S;
6037 }
6038 
6039 static DecodeStatus DecodeVCVTQ(MCInst &Inst, unsigned Insn, uint64_t Address,
6040                                 const MCDisassembler *Decoder) {
6041   const FeatureBitset &featureBits =
6042       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
6043   bool hasFullFP16 = featureBits[ARM::FeatureFullFP16];
6044 
6045   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
6046   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
6047   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
6048   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
6049   unsigned imm = fieldFromInstruction(Insn, 16, 6);
6050   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
6051   unsigned op = fieldFromInstruction(Insn, 5, 1);
6052 
6053   DecodeStatus S = MCDisassembler::Success;
6054 
6055   // If the top 3 bits of imm are clear, this is a VMOV (immediate)
6056   if (!(imm & 0x38)) {
6057     if (cmode == 0xF) {
6058       if (op == 1) return MCDisassembler::Fail;
6059       Inst.setOpcode(ARM::VMOVv4f32);
6060     }
6061     if (hasFullFP16) {
6062       if (cmode == 0xE) {
6063         if (op == 1) {
6064           Inst.setOpcode(ARM::VMOVv2i64);
6065         } else {
6066           Inst.setOpcode(ARM::VMOVv16i8);
6067         }
6068       }
6069       if (cmode == 0xD) {
6070         if (op == 1) {
6071           Inst.setOpcode(ARM::VMVNv4i32);
6072         } else {
6073           Inst.setOpcode(ARM::VMOVv4i32);
6074         }
6075       }
6076       if (cmode == 0xC) {
6077         if (op == 1) {
6078           Inst.setOpcode(ARM::VMVNv4i32);
6079         } else {
6080           Inst.setOpcode(ARM::VMOVv4i32);
6081         }
6082       }
6083     }
6084     return DecodeVMOVModImmInstruction(Inst, Insn, Address, Decoder);
6085   }
6086 
6087   if (!(imm & 0x20)) return MCDisassembler::Fail;
6088 
6089   if (!Check(S, DecodeQPRRegisterClass(Inst, Vd, Address, Decoder)))
6090     return MCDisassembler::Fail;
6091   if (!Check(S, DecodeQPRRegisterClass(Inst, Vm, Address, Decoder)))
6092     return MCDisassembler::Fail;
6093   Inst.addOperand(MCOperand::createImm(64 - imm));
6094 
6095   return S;
6096 }
6097 
6098 static DecodeStatus
6099 DecodeNEONComplexLane64Instruction(MCInst &Inst, unsigned Insn,
6100                                    uint64_t Address,
6101                                    const MCDisassembler *Decoder) {
6102   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
6103   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
6104   unsigned Vn = (fieldFromInstruction(Insn, 16, 4) << 0);
6105   Vn |= (fieldFromInstruction(Insn, 7, 1) << 4);
6106   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
6107   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
6108   unsigned q = (fieldFromInstruction(Insn, 6, 1) << 0);
6109   unsigned rotate = (fieldFromInstruction(Insn, 20, 2) << 0);
6110 
6111   DecodeStatus S = MCDisassembler::Success;
6112 
6113   auto DestRegDecoder = q ? DecodeQPRRegisterClass : DecodeDPRRegisterClass;
6114 
6115   if (!Check(S, DestRegDecoder(Inst, Vd, Address, Decoder)))
6116     return MCDisassembler::Fail;
6117   if (!Check(S, DestRegDecoder(Inst, Vd, Address, Decoder)))
6118     return MCDisassembler::Fail;
6119   if (!Check(S, DestRegDecoder(Inst, Vn, Address, Decoder)))
6120     return MCDisassembler::Fail;
6121   if (!Check(S, DecodeDPRRegisterClass(Inst, Vm, Address, Decoder)))
6122     return MCDisassembler::Fail;
6123   // The lane index does not have any bits in the encoding, because it can only
6124   // be 0.
6125   Inst.addOperand(MCOperand::createImm(0));
6126   Inst.addOperand(MCOperand::createImm(rotate));
6127 
6128   return S;
6129 }
6130 
6131 static DecodeStatus DecodeLDR(MCInst &Inst, unsigned Val, uint64_t Address,
6132                               const MCDisassembler *Decoder) {
6133   DecodeStatus S = MCDisassembler::Success;
6134 
6135   unsigned Rn = fieldFromInstruction(Val, 16, 4);
6136   unsigned Rt = fieldFromInstruction(Val, 12, 4);
6137   unsigned Rm = fieldFromInstruction(Val, 0, 4);
6138   Rm |= (fieldFromInstruction(Val, 23, 1) << 4);
6139   unsigned Cond = fieldFromInstruction(Val, 28, 4);
6140 
6141   if (fieldFromInstruction(Val, 8, 4) != 0 || Rn == Rt)
6142     S = MCDisassembler::SoftFail;
6143 
6144   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
6145     return MCDisassembler::Fail;
6146   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
6147     return MCDisassembler::Fail;
6148   if (!Check(S, DecodeAddrMode7Operand(Inst, Rn, Address, Decoder)))
6149     return MCDisassembler::Fail;
6150   if (!Check(S, DecodePostIdxReg(Inst, Rm, Address, Decoder)))
6151     return MCDisassembler::Fail;
6152   if (!Check(S, DecodePredicateOperand(Inst, Cond, Address, Decoder)))
6153     return MCDisassembler::Fail;
6154 
6155   return S;
6156 }
6157 
6158 static DecodeStatus DecoderForMRRC2AndMCRR2(MCInst &Inst, unsigned Val,
6159                                             uint64_t Address,
6160                                             const MCDisassembler *Decoder) {
6161   DecodeStatus S = MCDisassembler::Success;
6162 
6163   unsigned CRm = fieldFromInstruction(Val, 0, 4);
6164   unsigned opc1 = fieldFromInstruction(Val, 4, 4);
6165   unsigned cop = fieldFromInstruction(Val, 8, 4);
6166   unsigned Rt = fieldFromInstruction(Val, 12, 4);
6167   unsigned Rt2 = fieldFromInstruction(Val, 16, 4);
6168 
6169   if ((cop & ~0x1) == 0xa)
6170     return MCDisassembler::Fail;
6171 
6172   if (Rt == Rt2)
6173     S = MCDisassembler::SoftFail;
6174 
6175   // We have to check if the instruction is MRRC2
6176   // or MCRR2 when constructing the operands for
6177   // Inst. Reason is because MRRC2 stores to two
6178   // registers so it's tablegen desc has has two
6179   // outputs whereas MCRR doesn't store to any
6180   // registers so all of it's operands are listed
6181   // as inputs, therefore the operand order for
6182   // MRRC2 needs to be [Rt, Rt2, cop, opc1, CRm]
6183   // and MCRR2 operand order is [cop, opc1, Rt, Rt2, CRm]
6184 
6185   if (Inst.getOpcode() == ARM::MRRC2) {
6186     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
6187       return MCDisassembler::Fail;
6188     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
6189       return MCDisassembler::Fail;
6190   }
6191   Inst.addOperand(MCOperand::createImm(cop));
6192   Inst.addOperand(MCOperand::createImm(opc1));
6193   if (Inst.getOpcode() == ARM::MCRR2) {
6194     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
6195       return MCDisassembler::Fail;
6196     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
6197       return MCDisassembler::Fail;
6198   }
6199   Inst.addOperand(MCOperand::createImm(CRm));
6200 
6201   return S;
6202 }
6203 
6204 static DecodeStatus DecodeForVMRSandVMSR(MCInst &Inst, unsigned Val,
6205                                          uint64_t Address,
6206                                          const MCDisassembler *Decoder) {
6207   const FeatureBitset &featureBits =
6208       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
6209   DecodeStatus S = MCDisassembler::Success;
6210 
6211   // Add explicit operand for the destination sysreg, for cases where
6212   // we have to model it for code generation purposes.
6213   switch (Inst.getOpcode()) {
6214   case ARM::VMSR_FPSCR_NZCVQC:
6215     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
6216     break;
6217   case ARM::VMSR_P0:
6218     Inst.addOperand(MCOperand::createReg(ARM::VPR));
6219     break;
6220   }
6221 
6222   if (Inst.getOpcode() != ARM::FMSTAT) {
6223     unsigned Rt = fieldFromInstruction(Val, 12, 4);
6224 
6225     if (featureBits[ARM::ModeThumb] && !featureBits[ARM::HasV8Ops]) {
6226       if (Rt == 13 || Rt == 15)
6227         S = MCDisassembler::SoftFail;
6228       Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder));
6229     } else
6230       Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder));
6231   }
6232 
6233   // Add explicit operand for the source sysreg, similarly to above.
6234   switch (Inst.getOpcode()) {
6235   case ARM::VMRS_FPSCR_NZCVQC:
6236     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
6237     break;
6238   case ARM::VMRS_P0:
6239     Inst.addOperand(MCOperand::createReg(ARM::VPR));
6240     break;
6241   }
6242 
6243   if (featureBits[ARM::ModeThumb]) {
6244     Inst.addOperand(MCOperand::createImm(ARMCC::AL));
6245     Inst.addOperand(MCOperand::createReg(0));
6246   } else {
6247     unsigned pred = fieldFromInstruction(Val, 28, 4);
6248     if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
6249       return MCDisassembler::Fail;
6250   }
6251 
6252   return S;
6253 }
6254 
6255 template <bool isSigned, bool isNeg, bool zeroPermitted, int size>
6256 static DecodeStatus DecodeBFLabelOperand(MCInst &Inst, unsigned Val,
6257                                          uint64_t Address,
6258                                          const MCDisassembler *Decoder) {
6259   DecodeStatus S = MCDisassembler::Success;
6260   if (Val == 0 && !zeroPermitted)
6261     S = MCDisassembler::Fail;
6262 
6263   uint64_t DecVal;
6264   if (isSigned)
6265     DecVal = SignExtend32<size + 1>(Val << 1);
6266   else
6267     DecVal = (Val << 1);
6268 
6269   if (!tryAddingSymbolicOperand(Address, Address + DecVal + 4, true, 4, Inst,
6270                                 Decoder))
6271     Inst.addOperand(MCOperand::createImm(isNeg ? -DecVal : DecVal));
6272   return S;
6273 }
6274 
6275 static DecodeStatus DecodeBFAfterTargetOperand(MCInst &Inst, unsigned Val,
6276                                                uint64_t Address,
6277                                                const MCDisassembler *Decoder) {
6278 
6279   uint64_t LocImm = Inst.getOperand(0).getImm();
6280   Val = LocImm + (2 << Val);
6281   if (!tryAddingSymbolicOperand(Address, Address + Val + 4, true, 4, Inst,
6282                                 Decoder))
6283     Inst.addOperand(MCOperand::createImm(Val));
6284   return MCDisassembler::Success;
6285 }
6286 
6287 static DecodeStatus DecodePredNoALOperand(MCInst &Inst, unsigned Val,
6288                                           uint64_t Address,
6289                                           const MCDisassembler *Decoder) {
6290   if (Val >= ARMCC::AL)  // also exclude the non-condition NV
6291     return MCDisassembler::Fail;
6292   Inst.addOperand(MCOperand::createImm(Val));
6293   return MCDisassembler::Success;
6294 }
6295 
6296 static DecodeStatus DecodeLOLoop(MCInst &Inst, unsigned Insn, uint64_t Address,
6297                                  const MCDisassembler *Decoder) {
6298   DecodeStatus S = MCDisassembler::Success;
6299 
6300   if (Inst.getOpcode() == ARM::MVE_LCTP)
6301     return S;
6302 
6303   unsigned Imm = fieldFromInstruction(Insn, 11, 1) |
6304                  fieldFromInstruction(Insn, 1, 10) << 1;
6305   switch (Inst.getOpcode()) {
6306   case ARM::t2LEUpdate:
6307   case ARM::MVE_LETP:
6308     Inst.addOperand(MCOperand::createReg(ARM::LR));
6309     Inst.addOperand(MCOperand::createReg(ARM::LR));
6310     LLVM_FALLTHROUGH;
6311   case ARM::t2LE:
6312     if (!Check(S, DecodeBFLabelOperand<false, true, true, 11>(
6313                    Inst, Imm, Address, Decoder)))
6314       return MCDisassembler::Fail;
6315     break;
6316   case ARM::t2WLS:
6317   case ARM::MVE_WLSTP_8:
6318   case ARM::MVE_WLSTP_16:
6319   case ARM::MVE_WLSTP_32:
6320   case ARM::MVE_WLSTP_64:
6321     Inst.addOperand(MCOperand::createReg(ARM::LR));
6322     if (!Check(S,
6323                DecoderGPRRegisterClass(Inst, fieldFromInstruction(Insn, 16, 4),
6324                                        Address, Decoder)) ||
6325         !Check(S, DecodeBFLabelOperand<false, false, true, 11>(
6326                    Inst, Imm, Address, Decoder)))
6327       return MCDisassembler::Fail;
6328     break;
6329   case ARM::t2DLS:
6330   case ARM::MVE_DLSTP_8:
6331   case ARM::MVE_DLSTP_16:
6332   case ARM::MVE_DLSTP_32:
6333   case ARM::MVE_DLSTP_64:
6334     unsigned Rn = fieldFromInstruction(Insn, 16, 4);
6335     if (Rn == 0xF) {
6336       // Enforce all the rest of the instruction bits in LCTP, which
6337       // won't have been reliably checked based on LCTP's own tablegen
6338       // record, because we came to this decode by a roundabout route.
6339       uint32_t CanonicalLCTP = 0xF00FE001, SBZMask = 0x00300FFE;
6340       if ((Insn & ~SBZMask) != CanonicalLCTP)
6341         return MCDisassembler::Fail;   // a mandatory bit is wrong: hard fail
6342       if (Insn != CanonicalLCTP)
6343         Check(S, MCDisassembler::SoftFail); // an SBZ bit is wrong: soft fail
6344 
6345       Inst.setOpcode(ARM::MVE_LCTP);
6346     } else {
6347       Inst.addOperand(MCOperand::createReg(ARM::LR));
6348       if (!Check(S, DecoderGPRRegisterClass(Inst,
6349                                             fieldFromInstruction(Insn, 16, 4),
6350                                             Address, Decoder)))
6351         return MCDisassembler::Fail;
6352     }
6353     break;
6354   }
6355   return S;
6356 }
6357 
6358 static DecodeStatus DecodeLongShiftOperand(MCInst &Inst, unsigned Val,
6359                                            uint64_t Address,
6360                                            const MCDisassembler *Decoder) {
6361   DecodeStatus S = MCDisassembler::Success;
6362 
6363   if (Val == 0)
6364     Val = 32;
6365 
6366   Inst.addOperand(MCOperand::createImm(Val));
6367 
6368   return S;
6369 }
6370 
6371 static DecodeStatus DecodetGPROddRegisterClass(MCInst &Inst, unsigned RegNo,
6372                                                uint64_t Address,
6373                                                const MCDisassembler *Decoder) {
6374   if ((RegNo) + 1 > 11)
6375     return MCDisassembler::Fail;
6376 
6377   unsigned Register = GPRDecoderTable[(RegNo) + 1];
6378   Inst.addOperand(MCOperand::createReg(Register));
6379   return MCDisassembler::Success;
6380 }
6381 
6382 static DecodeStatus DecodetGPREvenRegisterClass(MCInst &Inst, unsigned RegNo,
6383                                                 uint64_t Address,
6384                                                 const MCDisassembler *Decoder) {
6385   if ((RegNo) > 14)
6386     return MCDisassembler::Fail;
6387 
6388   unsigned Register = GPRDecoderTable[(RegNo)];
6389   Inst.addOperand(MCOperand::createReg(Register));
6390   return MCDisassembler::Success;
6391 }
6392 
6393 static DecodeStatus
6394 DecodeGPRwithAPSR_NZCVnospRegisterClass(MCInst &Inst, unsigned RegNo,
6395                                         uint64_t Address,
6396                                         const MCDisassembler *Decoder) {
6397   if (RegNo == 15) {
6398     Inst.addOperand(MCOperand::createReg(ARM::APSR_NZCV));
6399     return MCDisassembler::Success;
6400   }
6401 
6402   unsigned Register = GPRDecoderTable[RegNo];
6403   Inst.addOperand(MCOperand::createReg(Register));
6404 
6405   if (RegNo == 13)
6406     return MCDisassembler::SoftFail;
6407 
6408   return MCDisassembler::Success;
6409 }
6410 
6411 static DecodeStatus DecodeVSCCLRM(MCInst &Inst, unsigned Insn, uint64_t Address,
6412                                   const MCDisassembler *Decoder) {
6413   DecodeStatus S = MCDisassembler::Success;
6414 
6415   Inst.addOperand(MCOperand::createImm(ARMCC::AL));
6416   Inst.addOperand(MCOperand::createReg(0));
6417   if (Inst.getOpcode() == ARM::VSCCLRMD) {
6418     unsigned reglist = (fieldFromInstruction(Insn, 1, 7) << 1) |
6419                        (fieldFromInstruction(Insn, 12, 4) << 8) |
6420                        (fieldFromInstruction(Insn, 22, 1) << 12);
6421     if (!Check(S, DecodeDPRRegListOperand(Inst, reglist, Address, Decoder))) {
6422       return MCDisassembler::Fail;
6423     }
6424   } else {
6425     unsigned reglist = fieldFromInstruction(Insn, 0, 8) |
6426                        (fieldFromInstruction(Insn, 22, 1) << 8) |
6427                        (fieldFromInstruction(Insn, 12, 4) << 9);
6428     if (!Check(S, DecodeSPRRegListOperand(Inst, reglist, Address, Decoder))) {
6429       return MCDisassembler::Fail;
6430     }
6431   }
6432   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6433 
6434   return S;
6435 }
6436 
6437 static DecodeStatus DecodeMQPRRegisterClass(MCInst &Inst, unsigned RegNo,
6438                                             uint64_t Address,
6439                                             const MCDisassembler *Decoder) {
6440   if (RegNo > 7)
6441     return MCDisassembler::Fail;
6442 
6443   unsigned Register = QPRDecoderTable[RegNo];
6444   Inst.addOperand(MCOperand::createReg(Register));
6445   return MCDisassembler::Success;
6446 }
6447 
6448 static const uint16_t QQPRDecoderTable[] = {
6449      ARM::Q0_Q1,  ARM::Q1_Q2,  ARM::Q2_Q3,  ARM::Q3_Q4,
6450      ARM::Q4_Q5,  ARM::Q5_Q6,  ARM::Q6_Q7
6451 };
6452 
6453 static DecodeStatus DecodeMQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
6454                                              uint64_t Address,
6455                                              const MCDisassembler *Decoder) {
6456   if (RegNo > 6)
6457     return MCDisassembler::Fail;
6458 
6459   unsigned Register = QQPRDecoderTable[RegNo];
6460   Inst.addOperand(MCOperand::createReg(Register));
6461   return MCDisassembler::Success;
6462 }
6463 
6464 static const uint16_t QQQQPRDecoderTable[] = {
6465      ARM::Q0_Q1_Q2_Q3,  ARM::Q1_Q2_Q3_Q4,  ARM::Q2_Q3_Q4_Q5,
6466      ARM::Q3_Q4_Q5_Q6,  ARM::Q4_Q5_Q6_Q7
6467 };
6468 
6469 static DecodeStatus DecodeMQQQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
6470                                                uint64_t Address,
6471                                                const MCDisassembler *Decoder) {
6472   if (RegNo > 4)
6473     return MCDisassembler::Fail;
6474 
6475   unsigned Register = QQQQPRDecoderTable[RegNo];
6476   Inst.addOperand(MCOperand::createReg(Register));
6477   return MCDisassembler::Success;
6478 }
6479 
6480 static DecodeStatus DecodeVPTMaskOperand(MCInst &Inst, unsigned Val,
6481                                          uint64_t Address,
6482                                          const MCDisassembler *Decoder) {
6483   DecodeStatus S = MCDisassembler::Success;
6484 
6485   // Parse VPT mask and encode it in the MCInst as an immediate with the same
6486   // format as the it_mask.  That is, from the second 'e|t' encode 'e' as 1 and
6487   // 't' as 0 and finish with a 1.
6488   unsigned Imm = 0;
6489   // We always start with a 't'.
6490   unsigned CurBit = 0;
6491   for (int i = 3; i >= 0; --i) {
6492     // If the bit we are looking at is not the same as last one, invert the
6493     // CurBit, if it is the same leave it as is.
6494     CurBit ^= (Val >> i) & 1U;
6495 
6496     // Encode the CurBit at the right place in the immediate.
6497     Imm |= (CurBit << i);
6498 
6499     // If we are done, finish the encoding with a 1.
6500     if ((Val & ~(~0U << i)) == 0) {
6501       Imm |= 1U << i;
6502       break;
6503     }
6504   }
6505 
6506   Inst.addOperand(MCOperand::createImm(Imm));
6507 
6508   return S;
6509 }
6510 
6511 static DecodeStatus DecodeVpredROperand(MCInst &Inst, unsigned RegNo,
6512                                         uint64_t Address,
6513                                         const MCDisassembler *Decoder) {
6514   // The vpred_r operand type includes an MQPR register field derived
6515   // from the encoding. But we don't actually want to add an operand
6516   // to the MCInst at this stage, because AddThumbPredicate will do it
6517   // later, and will infer the register number from the TIED_TO
6518   // constraint. So this is a deliberately empty decoder method that
6519   // will inhibit the auto-generated disassembly code from adding an
6520   // operand at all.
6521   return MCDisassembler::Success;
6522 }
6523 
6524 static DecodeStatus
6525 DecodeRestrictedIPredicateOperand(MCInst &Inst, unsigned Val, uint64_t Address,
6526                                   const MCDisassembler *Decoder) {
6527   Inst.addOperand(MCOperand::createImm((Val & 0x1) == 0 ? ARMCC::EQ : ARMCC::NE));
6528   return MCDisassembler::Success;
6529 }
6530 
6531 static DecodeStatus
6532 DecodeRestrictedSPredicateOperand(MCInst &Inst, unsigned Val, uint64_t Address,
6533                                   const MCDisassembler *Decoder) {
6534   unsigned Code;
6535   switch (Val & 0x3) {
6536   case 0:
6537     Code = ARMCC::GE;
6538     break;
6539   case 1:
6540     Code = ARMCC::LT;
6541     break;
6542   case 2:
6543     Code = ARMCC::GT;
6544     break;
6545   case 3:
6546     Code = ARMCC::LE;
6547     break;
6548   }
6549   Inst.addOperand(MCOperand::createImm(Code));
6550   return MCDisassembler::Success;
6551 }
6552 
6553 static DecodeStatus
6554 DecodeRestrictedUPredicateOperand(MCInst &Inst, unsigned Val, uint64_t Address,
6555                                   const MCDisassembler *Decoder) {
6556   Inst.addOperand(MCOperand::createImm((Val & 0x1) == 0 ? ARMCC::HS : ARMCC::HI));
6557   return MCDisassembler::Success;
6558 }
6559 
6560 static DecodeStatus
6561 DecodeRestrictedFPPredicateOperand(MCInst &Inst, unsigned Val, uint64_t Address,
6562                                    const MCDisassembler *Decoder) {
6563   unsigned Code;
6564   switch (Val) {
6565   default:
6566     return MCDisassembler::Fail;
6567   case 0:
6568     Code = ARMCC::EQ;
6569     break;
6570   case 1:
6571     Code = ARMCC::NE;
6572     break;
6573   case 4:
6574     Code = ARMCC::GE;
6575     break;
6576   case 5:
6577     Code = ARMCC::LT;
6578     break;
6579   case 6:
6580     Code = ARMCC::GT;
6581     break;
6582   case 7:
6583     Code = ARMCC::LE;
6584     break;
6585   }
6586 
6587   Inst.addOperand(MCOperand::createImm(Code));
6588   return MCDisassembler::Success;
6589 }
6590 
6591 static DecodeStatus DecodeVCVTImmOperand(MCInst &Inst, unsigned Val,
6592                                          uint64_t Address,
6593                                          const MCDisassembler *Decoder) {
6594   DecodeStatus S = MCDisassembler::Success;
6595 
6596   unsigned DecodedVal = 64 - Val;
6597 
6598   switch (Inst.getOpcode()) {
6599   case ARM::MVE_VCVTf16s16_fix:
6600   case ARM::MVE_VCVTs16f16_fix:
6601   case ARM::MVE_VCVTf16u16_fix:
6602   case ARM::MVE_VCVTu16f16_fix:
6603     if (DecodedVal > 16)
6604       return MCDisassembler::Fail;
6605     break;
6606   case ARM::MVE_VCVTf32s32_fix:
6607   case ARM::MVE_VCVTs32f32_fix:
6608   case ARM::MVE_VCVTf32u32_fix:
6609   case ARM::MVE_VCVTu32f32_fix:
6610     if (DecodedVal > 32)
6611       return MCDisassembler::Fail;
6612     break;
6613   }
6614 
6615   Inst.addOperand(MCOperand::createImm(64 - Val));
6616 
6617   return S;
6618 }
6619 
6620 static unsigned FixedRegForVSTRVLDR_SYSREG(unsigned Opcode) {
6621   switch (Opcode) {
6622   case ARM::VSTR_P0_off:
6623   case ARM::VSTR_P0_pre:
6624   case ARM::VSTR_P0_post:
6625   case ARM::VLDR_P0_off:
6626   case ARM::VLDR_P0_pre:
6627   case ARM::VLDR_P0_post:
6628     return ARM::P0;
6629   default:
6630     return 0;
6631   }
6632 }
6633 
6634 template <bool Writeback>
6635 static DecodeStatus DecodeVSTRVLDR_SYSREG(MCInst &Inst, unsigned Val,
6636                                           uint64_t Address,
6637                                           const MCDisassembler *Decoder) {
6638   switch (Inst.getOpcode()) {
6639   case ARM::VSTR_FPSCR_pre:
6640   case ARM::VSTR_FPSCR_NZCVQC_pre:
6641   case ARM::VLDR_FPSCR_pre:
6642   case ARM::VLDR_FPSCR_NZCVQC_pre:
6643   case ARM::VSTR_FPSCR_off:
6644   case ARM::VSTR_FPSCR_NZCVQC_off:
6645   case ARM::VLDR_FPSCR_off:
6646   case ARM::VLDR_FPSCR_NZCVQC_off:
6647   case ARM::VSTR_FPSCR_post:
6648   case ARM::VSTR_FPSCR_NZCVQC_post:
6649   case ARM::VLDR_FPSCR_post:
6650   case ARM::VLDR_FPSCR_NZCVQC_post:
6651     const FeatureBitset &featureBits =
6652         ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
6653 
6654     if (!featureBits[ARM::HasMVEIntegerOps] && !featureBits[ARM::FeatureVFP2])
6655       return MCDisassembler::Fail;
6656   }
6657 
6658   DecodeStatus S = MCDisassembler::Success;
6659   if (unsigned Sysreg = FixedRegForVSTRVLDR_SYSREG(Inst.getOpcode()))
6660     Inst.addOperand(MCOperand::createReg(Sysreg));
6661   unsigned Rn = fieldFromInstruction(Val, 16, 4);
6662   unsigned addr = fieldFromInstruction(Val, 0, 7) |
6663                   (fieldFromInstruction(Val, 23, 1) << 7) | (Rn << 8);
6664 
6665   if (Writeback) {
6666     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
6667       return MCDisassembler::Fail;
6668   }
6669   if (!Check(S, DecodeT2AddrModeImm7s4(Inst, addr, Address, Decoder)))
6670     return MCDisassembler::Fail;
6671 
6672   Inst.addOperand(MCOperand::createImm(ARMCC::AL));
6673   Inst.addOperand(MCOperand::createReg(0));
6674 
6675   return S;
6676 }
6677 
6678 static inline DecodeStatus
6679 DecodeMVE_MEM_pre(MCInst &Inst, unsigned Val, uint64_t Address,
6680                   const MCDisassembler *Decoder, unsigned Rn,
6681                   OperandDecoder RnDecoder, OperandDecoder AddrDecoder) {
6682   DecodeStatus S = MCDisassembler::Success;
6683 
6684   unsigned Qd = fieldFromInstruction(Val, 13, 3);
6685   unsigned addr = fieldFromInstruction(Val, 0, 7) |
6686                   (fieldFromInstruction(Val, 23, 1) << 7) | (Rn << 8);
6687 
6688   if (!Check(S, RnDecoder(Inst, Rn, Address, Decoder)))
6689     return MCDisassembler::Fail;
6690   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6691     return MCDisassembler::Fail;
6692   if (!Check(S, AddrDecoder(Inst, addr, Address, Decoder)))
6693     return MCDisassembler::Fail;
6694 
6695   return S;
6696 }
6697 
6698 template <int shift>
6699 static DecodeStatus DecodeMVE_MEM_1_pre(MCInst &Inst, unsigned Val,
6700                                         uint64_t Address,
6701                                         const MCDisassembler *Decoder) {
6702   return DecodeMVE_MEM_pre(Inst, Val, Address, Decoder,
6703                            fieldFromInstruction(Val, 16, 3),
6704                            DecodetGPRRegisterClass,
6705                            DecodeTAddrModeImm7<shift>);
6706 }
6707 
6708 template <int shift>
6709 static DecodeStatus DecodeMVE_MEM_2_pre(MCInst &Inst, unsigned Val,
6710                                         uint64_t Address,
6711                                         const MCDisassembler *Decoder) {
6712   return DecodeMVE_MEM_pre(Inst, Val, Address, Decoder,
6713                            fieldFromInstruction(Val, 16, 4),
6714                            DecoderGPRRegisterClass,
6715                            DecodeT2AddrModeImm7<shift,1>);
6716 }
6717 
6718 template <int shift>
6719 static DecodeStatus DecodeMVE_MEM_3_pre(MCInst &Inst, unsigned Val,
6720                                         uint64_t Address,
6721                                         const MCDisassembler *Decoder) {
6722   return DecodeMVE_MEM_pre(Inst, Val, Address, Decoder,
6723                            fieldFromInstruction(Val, 17, 3),
6724                            DecodeMQPRRegisterClass,
6725                            DecodeMveAddrModeQ<shift>);
6726 }
6727 
6728 template <unsigned MinLog, unsigned MaxLog>
6729 static DecodeStatus DecodePowerTwoOperand(MCInst &Inst, unsigned Val,
6730                                           uint64_t Address,
6731                                           const MCDisassembler *Decoder) {
6732   DecodeStatus S = MCDisassembler::Success;
6733 
6734   if (Val < MinLog || Val > MaxLog)
6735     return MCDisassembler::Fail;
6736 
6737   Inst.addOperand(MCOperand::createImm(1LL << Val));
6738   return S;
6739 }
6740 
6741 template <unsigned start>
6742 static DecodeStatus
6743 DecodeMVEPairVectorIndexOperand(MCInst &Inst, unsigned Val, uint64_t Address,
6744                                 const MCDisassembler *Decoder) {
6745   DecodeStatus S = MCDisassembler::Success;
6746 
6747   Inst.addOperand(MCOperand::createImm(start + Val));
6748 
6749   return S;
6750 }
6751 
6752 static DecodeStatus DecodeMVEVMOVQtoDReg(MCInst &Inst, unsigned Insn,
6753                                          uint64_t Address,
6754                                          const MCDisassembler *Decoder) {
6755   DecodeStatus S = MCDisassembler::Success;
6756   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
6757   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
6758   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
6759                  fieldFromInstruction(Insn, 13, 3));
6760   unsigned index = fieldFromInstruction(Insn, 4, 1);
6761 
6762   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
6763     return MCDisassembler::Fail;
6764   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2, Address, Decoder)))
6765     return MCDisassembler::Fail;
6766   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6767     return MCDisassembler::Fail;
6768   if (!Check(S, DecodeMVEPairVectorIndexOperand<2>(Inst, index, Address, Decoder)))
6769     return MCDisassembler::Fail;
6770   if (!Check(S, DecodeMVEPairVectorIndexOperand<0>(Inst, index, Address, Decoder)))
6771     return MCDisassembler::Fail;
6772 
6773   return S;
6774 }
6775 
6776 static DecodeStatus DecodeMVEVMOVDRegtoQ(MCInst &Inst, unsigned Insn,
6777                                          uint64_t Address,
6778                                          const MCDisassembler *Decoder) {
6779   DecodeStatus S = MCDisassembler::Success;
6780   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
6781   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
6782   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
6783                  fieldFromInstruction(Insn, 13, 3));
6784   unsigned index = fieldFromInstruction(Insn, 4, 1);
6785 
6786   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6787     return MCDisassembler::Fail;
6788   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6789     return MCDisassembler::Fail;
6790   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
6791     return MCDisassembler::Fail;
6792   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2, Address, Decoder)))
6793     return MCDisassembler::Fail;
6794   if (!Check(S, DecodeMVEPairVectorIndexOperand<2>(Inst, index, Address, Decoder)))
6795     return MCDisassembler::Fail;
6796   if (!Check(S, DecodeMVEPairVectorIndexOperand<0>(Inst, index, Address, Decoder)))
6797     return MCDisassembler::Fail;
6798 
6799   return S;
6800 }
6801 
6802 static DecodeStatus
6803 DecodeMVEOverlappingLongShift(MCInst &Inst, unsigned Insn, uint64_t Address,
6804                               const MCDisassembler *Decoder) {
6805   DecodeStatus S = MCDisassembler::Success;
6806 
6807   unsigned RdaLo = fieldFromInstruction(Insn, 17, 3) << 1;
6808   unsigned RdaHi = fieldFromInstruction(Insn, 9, 3) << 1;
6809   unsigned Rm = fieldFromInstruction(Insn, 12, 4);
6810 
6811   if (RdaHi == 14) {
6812     // This value of RdaHi (really indicating pc, because RdaHi has to
6813     // be an odd-numbered register, so the low bit will be set by the
6814     // decode function below) indicates that we must decode as SQRSHR
6815     // or UQRSHL, which both have a single Rda register field with all
6816     // four bits.
6817     unsigned Rda = fieldFromInstruction(Insn, 16, 4);
6818 
6819     switch (Inst.getOpcode()) {
6820       case ARM::MVE_ASRLr:
6821       case ARM::MVE_SQRSHRL:
6822         Inst.setOpcode(ARM::MVE_SQRSHR);
6823         break;
6824       case ARM::MVE_LSLLr:
6825       case ARM::MVE_UQRSHLL:
6826         Inst.setOpcode(ARM::MVE_UQRSHL);
6827         break;
6828       default:
6829         llvm_unreachable("Unexpected starting opcode!");
6830     }
6831 
6832     // Rda as output parameter
6833     if (!Check(S, DecoderGPRRegisterClass(Inst, Rda, Address, Decoder)))
6834       return MCDisassembler::Fail;
6835 
6836     // Rda again as input parameter
6837     if (!Check(S, DecoderGPRRegisterClass(Inst, Rda, Address, Decoder)))
6838       return MCDisassembler::Fail;
6839 
6840     // Rm, the amount to shift by
6841     if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
6842       return MCDisassembler::Fail;
6843 
6844     if (fieldFromInstruction (Insn, 6, 3) != 4)
6845       return MCDisassembler::SoftFail;
6846 
6847     if (Rda == Rm)
6848       return MCDisassembler::SoftFail;
6849 
6850     return S;
6851   }
6852 
6853   // Otherwise, we decode as whichever opcode our caller has already
6854   // put into Inst. Those all look the same:
6855 
6856   // RdaLo,RdaHi as output parameters
6857   if (!Check(S, DecodetGPREvenRegisterClass(Inst, RdaLo, Address, Decoder)))
6858     return MCDisassembler::Fail;
6859   if (!Check(S, DecodetGPROddRegisterClass(Inst, RdaHi, Address, Decoder)))
6860     return MCDisassembler::Fail;
6861 
6862   // RdaLo,RdaHi again as input parameters
6863   if (!Check(S, DecodetGPREvenRegisterClass(Inst, RdaLo, Address, Decoder)))
6864     return MCDisassembler::Fail;
6865   if (!Check(S, DecodetGPROddRegisterClass(Inst, RdaHi, Address, Decoder)))
6866     return MCDisassembler::Fail;
6867 
6868   // Rm, the amount to shift by
6869   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
6870     return MCDisassembler::Fail;
6871 
6872   if (Inst.getOpcode() == ARM::MVE_SQRSHRL ||
6873       Inst.getOpcode() == ARM::MVE_UQRSHLL) {
6874     unsigned Saturate = fieldFromInstruction(Insn, 7, 1);
6875     // Saturate, the bit position for saturation
6876     Inst.addOperand(MCOperand::createImm(Saturate));
6877   }
6878 
6879   return S;
6880 }
6881 
6882 static DecodeStatus DecodeMVEVCVTt1fp(MCInst &Inst, unsigned Insn,
6883                                       uint64_t Address,
6884                                       const MCDisassembler *Decoder) {
6885   DecodeStatus S = MCDisassembler::Success;
6886   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
6887                  fieldFromInstruction(Insn, 13, 3));
6888   unsigned Qm = ((fieldFromInstruction(Insn, 5, 1) << 3) |
6889                  fieldFromInstruction(Insn, 1, 3));
6890   unsigned imm6 = fieldFromInstruction(Insn, 16, 6);
6891 
6892   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6893     return MCDisassembler::Fail;
6894   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
6895     return MCDisassembler::Fail;
6896   if (!Check(S, DecodeVCVTImmOperand(Inst, imm6, Address, Decoder)))
6897     return MCDisassembler::Fail;
6898 
6899   return S;
6900 }
6901 
6902 template <bool scalar, OperandDecoder predicate_decoder>
6903 static DecodeStatus DecodeMVEVCMP(MCInst &Inst, unsigned Insn, uint64_t Address,
6904                                   const MCDisassembler *Decoder) {
6905   DecodeStatus S = MCDisassembler::Success;
6906   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6907   unsigned Qn = fieldFromInstruction(Insn, 17, 3);
6908   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qn, Address, Decoder)))
6909     return MCDisassembler::Fail;
6910 
6911   unsigned fc;
6912 
6913   if (scalar) {
6914     fc = fieldFromInstruction(Insn, 12, 1) << 2 |
6915          fieldFromInstruction(Insn, 7, 1) |
6916          fieldFromInstruction(Insn, 5, 1) << 1;
6917     unsigned Rm = fieldFromInstruction(Insn, 0, 4);
6918     if (!Check(S, DecodeGPRwithZRRegisterClass(Inst, Rm, Address, Decoder)))
6919       return MCDisassembler::Fail;
6920   } else {
6921     fc = fieldFromInstruction(Insn, 12, 1) << 2 |
6922          fieldFromInstruction(Insn, 7, 1) |
6923          fieldFromInstruction(Insn, 0, 1) << 1;
6924     unsigned Qm = fieldFromInstruction(Insn, 5, 1) << 4 |
6925                   fieldFromInstruction(Insn, 1, 3);
6926     if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
6927       return MCDisassembler::Fail;
6928   }
6929 
6930   if (!Check(S, predicate_decoder(Inst, fc, Address, Decoder)))
6931     return MCDisassembler::Fail;
6932 
6933   Inst.addOperand(MCOperand::createImm(ARMVCC::None));
6934   Inst.addOperand(MCOperand::createReg(0));
6935   Inst.addOperand(MCOperand::createImm(0));
6936 
6937   return S;
6938 }
6939 
6940 static DecodeStatus DecodeMveVCTP(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 Rn = fieldFromInstruction(Insn, 16, 4);
6945   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
6946     return MCDisassembler::Fail;
6947   return S;
6948 }
6949 
6950 static DecodeStatus DecodeMVEVPNOT(MCInst &Inst, unsigned Insn,
6951                                    uint64_t Address,
6952                                    const MCDisassembler *Decoder) {
6953   DecodeStatus S = MCDisassembler::Success;
6954   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6955   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6956   return S;
6957 }
6958 
6959 static DecodeStatus DecodeT2AddSubSPImm(MCInst &Inst, unsigned Insn,
6960                                         uint64_t Address,
6961                                         const MCDisassembler *Decoder) {
6962   const unsigned Rd = fieldFromInstruction(Insn, 8, 4);
6963   const unsigned Rn = fieldFromInstruction(Insn, 16, 4);
6964   const unsigned Imm12 = fieldFromInstruction(Insn, 26, 1) << 11 |
6965                          fieldFromInstruction(Insn, 12, 3) << 8 |
6966                          fieldFromInstruction(Insn, 0, 8);
6967   const unsigned TypeT3 = fieldFromInstruction(Insn, 25, 1);
6968   unsigned sign1 = fieldFromInstruction(Insn, 21, 1);
6969   unsigned sign2 = fieldFromInstruction(Insn, 23, 1);
6970   unsigned S = fieldFromInstruction(Insn, 20, 1);
6971   if (sign1 != sign2)
6972     return MCDisassembler::Fail;
6973 
6974   // T3 does a zext of imm12, where T2 does a ThumbExpandImm (T2SOImm)
6975   DecodeStatus DS = MCDisassembler::Success;
6976   if ((!Check(DS,
6977               DecodeGPRspRegisterClass(Inst, Rd, Address, Decoder))) || // dst
6978       (!Check(DS, DecodeGPRspRegisterClass(Inst, Rn, Address, Decoder))))
6979     return MCDisassembler::Fail;
6980   if (TypeT3) {
6981     Inst.setOpcode(sign1 ? ARM::t2SUBspImm12 : ARM::t2ADDspImm12);
6982     Inst.addOperand(MCOperand::createImm(Imm12)); // zext imm12
6983   } else {
6984     Inst.setOpcode(sign1 ? ARM::t2SUBspImm : ARM::t2ADDspImm);
6985     if (!Check(DS, DecodeT2SOImm(Inst, Imm12, Address, Decoder))) // imm12
6986       return MCDisassembler::Fail;
6987     if (!Check(DS, DecodeCCOutOperand(Inst, S, Address, Decoder))) // cc_out
6988       return MCDisassembler::Fail;
6989   }
6990 
6991   return DS;
6992 }
6993