xref: /llvm-project/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp (revision bdea88325f7208548c80fac84e1bbff920c6086f)
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/MCDisassembler/MCDisassembler.h"
17 #include "llvm/MC/MCFixedLenDisassembler.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/Support/Compiler.h"
23 #include "llvm/Support/ErrorHandling.h"
24 #include "llvm/Support/MathExtras.h"
25 #include "llvm/Support/TargetRegistry.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 &VStream,
141                               raw_ostream &CStream) const override;
142 
143 private:
144   DecodeStatus getARMInstruction(MCInst &Instr, uint64_t &Size,
145                                  ArrayRef<uint8_t> Bytes, uint64_t Address,
146                                  raw_ostream &VStream,
147                                  raw_ostream &CStream) const;
148 
149   DecodeStatus getThumbInstruction(MCInst &Instr, uint64_t &Size,
150                                    ArrayRef<uint8_t> Bytes, uint64_t Address,
151                                    raw_ostream &VStream,
152                                    raw_ostream &CStream) const;
153 
154   mutable ITStatus ITBlock;
155   mutable VPTStatus VPTBlock;
156 
157   DecodeStatus AddThumbPredicate(MCInst&) const;
158   void UpdateThumbVFPPredicate(DecodeStatus &, MCInst&) const;
159 };
160 
161 } // end anonymous namespace
162 
163 static bool Check(DecodeStatus &Out, DecodeStatus In) {
164   switch (In) {
165     case MCDisassembler::Success:
166       // Out stays the same.
167       return true;
168     case MCDisassembler::SoftFail:
169       Out = In;
170       return true;
171     case MCDisassembler::Fail:
172       Out = In;
173       return false;
174   }
175   llvm_unreachable("Invalid DecodeStatus!");
176 }
177 
178 // Forward declare these because the autogenerated code will reference them.
179 // Definitions are further down.
180 static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, unsigned RegNo,
181                                    uint64_t Address, const void *Decoder);
182 static DecodeStatus DecodeCLRMGPRRegisterClass(MCInst &Inst, unsigned RegNo,
183                                    uint64_t Address, const void *Decoder);
184 static DecodeStatus DecodetGPROddRegisterClass(MCInst &Inst, unsigned RegNo,
185                                    uint64_t Address, const void *Decoder);
186 static DecodeStatus DecodetGPREvenRegisterClass(MCInst &Inst, unsigned RegNo,
187                                    uint64_t Address, const void *Decoder);
188 static DecodeStatus DecodeGPRnopcRegisterClass(MCInst &Inst,
189                                                unsigned RegNo, uint64_t Address,
190                                                const void *Decoder);
191 static DecodeStatus DecodeGPRwithAPSRRegisterClass(MCInst &Inst,
192                                                unsigned RegNo, uint64_t Address,
193                                                const void *Decoder);
194 static DecodeStatus DecodeGPRwithZRRegisterClass(MCInst &Inst,
195                                                unsigned RegNo, uint64_t Address,
196                                                const void *Decoder);
197 static DecodeStatus DecodetGPRRegisterClass(MCInst &Inst, unsigned RegNo,
198                                    uint64_t Address, const void *Decoder);
199 static DecodeStatus DecodetcGPRRegisterClass(MCInst &Inst, unsigned RegNo,
200                                    uint64_t Address, const void *Decoder);
201 static DecodeStatus DecoderGPRRegisterClass(MCInst &Inst, unsigned RegNo,
202                                    uint64_t Address, const void *Decoder);
203 static DecodeStatus DecodeGPRPairRegisterClass(MCInst &Inst, unsigned RegNo,
204                                    uint64_t Address, const void *Decoder);
205 static DecodeStatus DecodeHPRRegisterClass(MCInst &Inst, unsigned RegNo,
206                                    uint64_t Address, const void *Decoder);
207 static DecodeStatus DecodeSPRRegisterClass(MCInst &Inst, unsigned RegNo,
208                                    uint64_t Address, const void *Decoder);
209 static DecodeStatus DecodeDPRRegisterClass(MCInst &Inst, unsigned RegNo,
210                                    uint64_t Address, const void *Decoder);
211 static DecodeStatus DecodeDPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
212                                    uint64_t Address, const void *Decoder);
213 static DecodeStatus DecodeSPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
214                                    uint64_t Address, const void *Decoder);
215 static DecodeStatus DecodeDPR_VFP2RegisterClass(MCInst &Inst,
216                                                 unsigned RegNo,
217                                                 uint64_t Address,
218                                                 const void *Decoder);
219 static DecodeStatus DecodeQPRRegisterClass(MCInst &Inst, unsigned RegNo,
220                                    uint64_t Address, const void *Decoder);
221 static DecodeStatus DecodeMQPRRegisterClass(MCInst &Inst, unsigned RegNo,
222                                    uint64_t Address, const void *Decoder);
223 static DecodeStatus DecodeDPairRegisterClass(MCInst &Inst, unsigned RegNo,
224                                    uint64_t Address, const void *Decoder);
225 static DecodeStatus DecodeDPairSpacedRegisterClass(MCInst &Inst,
226                                unsigned RegNo, uint64_t Address,
227                                const void *Decoder);
228 
229 static DecodeStatus DecodePredicateOperand(MCInst &Inst, unsigned Val,
230                                uint64_t Address, const void *Decoder);
231 static DecodeStatus DecodeCCOutOperand(MCInst &Inst, unsigned Val,
232                                uint64_t Address, const void *Decoder);
233 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Val,
234                                uint64_t Address, const void *Decoder);
235 static DecodeStatus DecodeSPRRegListOperand(MCInst &Inst, unsigned Val,
236                                uint64_t Address, const void *Decoder);
237 static DecodeStatus DecodeDPRRegListOperand(MCInst &Inst, unsigned Val,
238                                uint64_t Address, const void *Decoder);
239 
240 static DecodeStatus DecodeBitfieldMaskOperand(MCInst &Inst, unsigned Insn,
241                                uint64_t Address, const void *Decoder);
242 static DecodeStatus DecodeCopMemInstruction(MCInst &Inst, unsigned Insn,
243                                uint64_t Address, const void *Decoder);
244 static DecodeStatus DecodeAddrMode2IdxInstruction(MCInst &Inst,
245                                                   unsigned Insn,
246                                                   uint64_t Address,
247                                                   const void *Decoder);
248 static DecodeStatus DecodeSORegMemOperand(MCInst &Inst, unsigned Insn,
249                                uint64_t Address, const void *Decoder);
250 static DecodeStatus DecodeAddrMode3Instruction(MCInst &Inst,unsigned Insn,
251                                uint64_t Address, const void *Decoder);
252 static DecodeStatus DecodeSORegImmOperand(MCInst &Inst, unsigned Insn,
253                                uint64_t Address, const void *Decoder);
254 static DecodeStatus DecodeSORegRegOperand(MCInst &Inst, unsigned Insn,
255                                uint64_t Address, const void *Decoder);
256 
257 static DecodeStatus DecodeMemMultipleWritebackInstruction(MCInst & Inst,
258                                                   unsigned Insn,
259                                                   uint64_t Adddress,
260                                                   const void *Decoder);
261 static DecodeStatus DecodeT2MOVTWInstruction(MCInst &Inst, unsigned Insn,
262                                uint64_t Address, const void *Decoder);
263 static DecodeStatus DecodeArmMOVTWInstruction(MCInst &Inst, unsigned Insn,
264                                uint64_t Address, const void *Decoder);
265 static DecodeStatus DecodeSMLAInstruction(MCInst &Inst, unsigned Insn,
266                                uint64_t Address, const void *Decoder);
267 static DecodeStatus DecodeHINTInstruction(MCInst &Inst, unsigned Insn,
268                                uint64_t Address, const void *Decoder);
269 static DecodeStatus DecodeCPSInstruction(MCInst &Inst, unsigned Insn,
270                                uint64_t Address, const void *Decoder);
271 static DecodeStatus DecodeTSTInstruction(MCInst &Inst, unsigned Insn,
272                                uint64_t Address, const void *Decoder);
273 static DecodeStatus DecodeSETPANInstruction(MCInst &Inst, unsigned Insn,
274                                uint64_t Address, const void *Decoder);
275 static DecodeStatus DecodeT2CPSInstruction(MCInst &Inst, unsigned Insn,
276                                uint64_t Address, const void *Decoder);
277 static DecodeStatus DecodeAddrModeImm12Operand(MCInst &Inst, unsigned Val,
278                                uint64_t Address, const void *Decoder);
279 static DecodeStatus DecodeAddrMode5Operand(MCInst &Inst, unsigned Val,
280                                uint64_t Address, const void *Decoder);
281 static DecodeStatus DecodeAddrMode5FP16Operand(MCInst &Inst, unsigned Val,
282                                uint64_t Address, const void *Decoder);
283 static DecodeStatus DecodeAddrMode7Operand(MCInst &Inst, unsigned Val,
284                                uint64_t Address, const void *Decoder);
285 static DecodeStatus DecodeT2BInstruction(MCInst &Inst, unsigned Insn,
286                                uint64_t Address, const void *Decoder);
287 static DecodeStatus DecodeBranchImmInstruction(MCInst &Inst,unsigned Insn,
288                                uint64_t Address, const void *Decoder);
289 static DecodeStatus DecodeAddrMode6Operand(MCInst &Inst, unsigned Val,
290                                uint64_t Address, const void *Decoder);
291 static DecodeStatus DecodeVLDST1Instruction(MCInst &Inst, unsigned Val,
292                                uint64_t Address, const void *Decoder);
293 static DecodeStatus DecodeVLDST2Instruction(MCInst &Inst, unsigned Val,
294                                uint64_t Address, const void *Decoder);
295 static DecodeStatus DecodeVLDST3Instruction(MCInst &Inst, unsigned Val,
296                                uint64_t Address, const void *Decoder);
297 static DecodeStatus DecodeVLDST4Instruction(MCInst &Inst, unsigned Val,
298                                uint64_t Address, const void *Decoder);
299 static DecodeStatus DecodeVLDInstruction(MCInst &Inst, unsigned Val,
300                                uint64_t Address, const void *Decoder);
301 static DecodeStatus DecodeVSTInstruction(MCInst &Inst, unsigned Val,
302                                uint64_t Address, const void *Decoder);
303 static DecodeStatus DecodeVLD1DupInstruction(MCInst &Inst, unsigned Val,
304                                uint64_t Address, const void *Decoder);
305 static DecodeStatus DecodeVLD2DupInstruction(MCInst &Inst, unsigned Val,
306                                uint64_t Address, const void *Decoder);
307 static DecodeStatus DecodeVLD3DupInstruction(MCInst &Inst, unsigned Val,
308                                uint64_t Address, const void *Decoder);
309 static DecodeStatus DecodeVLD4DupInstruction(MCInst &Inst, unsigned Val,
310                                uint64_t Address, const void *Decoder);
311 static DecodeStatus DecodeNEONModImmInstruction(MCInst &Inst,unsigned Val,
312                                uint64_t Address, const void *Decoder);
313 static DecodeStatus DecodeMVEModImmInstruction(MCInst &Inst,unsigned Val,
314                                uint64_t Address, const void *Decoder);
315 static DecodeStatus DecodeMVEVADCInstruction(MCInst &Inst, unsigned Insn,
316                                uint64_t Address, const void *Decoder);
317 static DecodeStatus DecodeVSHLMaxInstruction(MCInst &Inst, unsigned Val,
318                                uint64_t Address, const void *Decoder);
319 static DecodeStatus DecodeShiftRight8Imm(MCInst &Inst, unsigned Val,
320                                uint64_t Address, const void *Decoder);
321 static DecodeStatus DecodeShiftRight16Imm(MCInst &Inst, unsigned Val,
322                                uint64_t Address, const void *Decoder);
323 static DecodeStatus DecodeShiftRight32Imm(MCInst &Inst, unsigned Val,
324                                uint64_t Address, const void *Decoder);
325 static DecodeStatus DecodeShiftRight64Imm(MCInst &Inst, unsigned Val,
326                                uint64_t Address, const void *Decoder);
327 static DecodeStatus DecodeTBLInstruction(MCInst &Inst, unsigned Insn,
328                                uint64_t Address, const void *Decoder);
329 static DecodeStatus DecodePostIdxReg(MCInst &Inst, unsigned Insn,
330                                uint64_t Address, const void *Decoder);
331 static DecodeStatus DecodeCoprocessor(MCInst &Inst, unsigned Insn,
332                                uint64_t Address, const void *Decoder);
333 static DecodeStatus DecodeMemBarrierOption(MCInst &Inst, unsigned Insn,
334                                uint64_t Address, const void *Decoder);
335 static DecodeStatus DecodeInstSyncBarrierOption(MCInst &Inst, unsigned Insn,
336                                uint64_t Address, const void *Decoder);
337 static DecodeStatus DecodeMSRMask(MCInst &Inst, unsigned Insn,
338                                uint64_t Address, const void *Decoder);
339 static DecodeStatus DecodeBankedReg(MCInst &Inst, unsigned Insn,
340                                uint64_t Address, const void *Decoder);
341 static DecodeStatus DecodeDoubleRegLoad(MCInst &Inst, unsigned Insn,
342                                uint64_t Address, const void *Decoder);
343 static DecodeStatus DecodeDoubleRegStore(MCInst &Inst, unsigned Insn,
344                                uint64_t Address, const void *Decoder);
345 static DecodeStatus DecodeLDRPreImm(MCInst &Inst, unsigned Insn,
346                                uint64_t Address, const void *Decoder);
347 static DecodeStatus DecodeLDRPreReg(MCInst &Inst, unsigned Insn,
348                                uint64_t Address, const void *Decoder);
349 static DecodeStatus DecodeSTRPreImm(MCInst &Inst, unsigned Insn,
350                                uint64_t Address, const void *Decoder);
351 static DecodeStatus DecodeSTRPreReg(MCInst &Inst, unsigned Insn,
352                                uint64_t Address, const void *Decoder);
353 static DecodeStatus DecodeVLD1LN(MCInst &Inst, unsigned Insn,
354                                uint64_t Address, const void *Decoder);
355 static DecodeStatus DecodeVLD2LN(MCInst &Inst, unsigned Insn,
356                                uint64_t Address, const void *Decoder);
357 static DecodeStatus DecodeVLD3LN(MCInst &Inst, unsigned Insn,
358                                uint64_t Address, const void *Decoder);
359 static DecodeStatus DecodeVLD4LN(MCInst &Inst, unsigned Insn,
360                                uint64_t Address, const void *Decoder);
361 static DecodeStatus DecodeVST1LN(MCInst &Inst, unsigned Insn,
362                                uint64_t Address, const void *Decoder);
363 static DecodeStatus DecodeVST2LN(MCInst &Inst, unsigned Insn,
364                                uint64_t Address, const void *Decoder);
365 static DecodeStatus DecodeVST3LN(MCInst &Inst, unsigned Insn,
366                                uint64_t Address, const void *Decoder);
367 static DecodeStatus DecodeVST4LN(MCInst &Inst, unsigned Insn,
368                                uint64_t Address, const void *Decoder);
369 static DecodeStatus DecodeVMOVSRR(MCInst &Inst, unsigned Insn,
370                                uint64_t Address, const void *Decoder);
371 static DecodeStatus DecodeVMOVRRS(MCInst &Inst, unsigned Insn,
372                                uint64_t Address, const void *Decoder);
373 static DecodeStatus DecodeSwap(MCInst &Inst, unsigned Insn,
374                                uint64_t Address, const void *Decoder);
375 static DecodeStatus DecodeVCVTD(MCInst &Inst, unsigned Insn,
376                                 uint64_t Address, const void *Decoder);
377 static DecodeStatus DecodeVCVTQ(MCInst &Inst, unsigned Insn,
378                                 uint64_t Address, const void *Decoder);
379 static DecodeStatus DecodeVCVTImmOperand(MCInst &Inst, unsigned Insn,
380                                          uint64_t Address, const void *Decoder);
381 static DecodeStatus DecodeNEONComplexLane64Instruction(MCInst &Inst,
382                                                        unsigned Val,
383                                                        uint64_t Address,
384                                                        const void *Decoder);
385 
386 static DecodeStatus DecodeThumbAddSpecialReg(MCInst &Inst, uint16_t Insn,
387                                uint64_t Address, const void *Decoder);
388 static DecodeStatus DecodeThumbBROperand(MCInst &Inst, unsigned Val,
389                                uint64_t Address, const void *Decoder);
390 static DecodeStatus DecodeT2BROperand(MCInst &Inst, unsigned Val,
391                                uint64_t Address, const void *Decoder);
392 static DecodeStatus DecodeThumbCmpBROperand(MCInst &Inst, unsigned Val,
393                                uint64_t Address, const void *Decoder);
394 static DecodeStatus DecodeThumbAddrModeRR(MCInst &Inst, unsigned Val,
395                                uint64_t Address, const void *Decoder);
396 static DecodeStatus DecodeThumbAddrModeIS(MCInst &Inst, unsigned Val,
397                                uint64_t Address, const void *Decoder);
398 static DecodeStatus DecodeThumbAddrModePC(MCInst &Inst, unsigned Val,
399                                uint64_t Address, const void *Decoder);
400 static DecodeStatus DecodeThumbAddrModeSP(MCInst &Inst, unsigned Val,
401                                uint64_t Address, const void *Decoder);
402 static DecodeStatus DecodeT2AddrModeSOReg(MCInst &Inst, unsigned Val,
403                                uint64_t Address, const void *Decoder);
404 static DecodeStatus DecodeT2LoadShift(MCInst &Inst, unsigned Val,
405                                uint64_t Address, const void *Decoder);
406 static DecodeStatus DecodeT2LoadImm8(MCInst &Inst, unsigned Insn,
407                                uint64_t Address, const void* Decoder);
408 static DecodeStatus DecodeT2LoadImm12(MCInst &Inst, unsigned Insn,
409                                uint64_t Address, const void* Decoder);
410 static DecodeStatus DecodeT2LoadT(MCInst &Inst, unsigned Insn,
411                                uint64_t Address, const void* Decoder);
412 static DecodeStatus DecodeT2LoadLabel(MCInst &Inst, unsigned Insn,
413                                uint64_t Address, const void* Decoder);
414 static DecodeStatus DecodeT2Imm8S4(MCInst &Inst, unsigned Val,
415                                uint64_t Address, const void *Decoder);
416 static DecodeStatus DecodeT2Imm7S4(MCInst &Inst, unsigned Val,
417                                uint64_t Address, const void *Decoder);
418 static DecodeStatus DecodeT2AddrModeImm8s4(MCInst &Inst, unsigned Val,
419                                uint64_t Address, const void *Decoder);
420 static DecodeStatus DecodeT2AddrModeImm7s4(MCInst &Inst, unsigned Val,
421                                            uint64_t Address,
422                                            const void *Decoder);
423 static DecodeStatus DecodeT2AddrModeImm0_1020s4(MCInst &Inst,unsigned Val,
424                                uint64_t Address, const void *Decoder);
425 static DecodeStatus DecodeT2Imm8(MCInst &Inst, unsigned Val,
426                                uint64_t Address, const void *Decoder);
427 static DecodeStatus DecodeT2AddrModeImm8(MCInst &Inst, unsigned Val,
428                                uint64_t Address, const void *Decoder);
429 static DecodeStatus DecodeThumbAddSPImm(MCInst &Inst, uint16_t Val,
430                                uint64_t Address, const void *Decoder);
431 static DecodeStatus DecodeThumbAddSPReg(MCInst &Inst, uint16_t Insn,
432                                 uint64_t Address, const void *Decoder);
433 static DecodeStatus DecodeThumbCPS(MCInst &Inst, uint16_t Insn,
434                                 uint64_t Address, const void *Decoder);
435 static DecodeStatus DecodeQADDInstruction(MCInst &Inst, unsigned Insn,
436                                 uint64_t Address, const void *Decoder);
437 static DecodeStatus DecodeThumbBLXOffset(MCInst &Inst, unsigned Insn,
438                                 uint64_t Address, const void *Decoder);
439 static DecodeStatus DecodeT2AddrModeImm12(MCInst &Inst, unsigned Val,
440                                 uint64_t Address, const void *Decoder);
441 static DecodeStatus DecodeThumbTableBranch(MCInst &Inst, unsigned Val,
442                                 uint64_t Address, const void *Decoder);
443 static DecodeStatus DecodeThumb2BCCInstruction(MCInst &Inst, unsigned Val,
444                                 uint64_t Address, const void *Decoder);
445 static DecodeStatus DecodeT2SOImm(MCInst &Inst, unsigned Val,
446                                 uint64_t Address, const void *Decoder);
447 static DecodeStatus DecodeThumbBCCTargetOperand(MCInst &Inst,unsigned Val,
448                                 uint64_t Address, const void *Decoder);
449 static DecodeStatus DecodeThumbBLTargetOperand(MCInst &Inst, unsigned Val,
450                                 uint64_t Address, const void *Decoder);
451 static DecodeStatus DecodeIT(MCInst &Inst, unsigned Val,
452                                 uint64_t Address, const void *Decoder);
453 static DecodeStatus DecodeT2LDRDPreInstruction(MCInst &Inst,unsigned Insn,
454                                uint64_t Address, const void *Decoder);
455 static DecodeStatus DecodeT2STRDPreInstruction(MCInst &Inst,unsigned Insn,
456                                uint64_t Address, const void *Decoder);
457 static DecodeStatus DecodeT2Adr(MCInst &Inst, unsigned Val,
458                                 uint64_t Address, const void *Decoder);
459 static DecodeStatus DecodeT2LdStPre(MCInst &Inst, unsigned Val,
460                                 uint64_t Address, const void *Decoder);
461 static DecodeStatus DecodeT2ShifterImmOperand(MCInst &Inst, unsigned Val,
462                                 uint64_t Address, const void *Decoder);
463 
464 static DecodeStatus DecodeLDR(MCInst &Inst, unsigned Val,
465                                 uint64_t Address, const void *Decoder);
466 static DecodeStatus DecoderForMRRC2AndMCRR2(MCInst &Inst, unsigned Val,
467                                             uint64_t Address, const void *Decoder);
468 static DecodeStatus DecodeForVMRSandVMSR(MCInst &Inst, unsigned Val,
469                                          uint64_t Address, const void *Decoder);
470 
471 template <bool isSigned, bool isNeg, int size>
472 static DecodeStatus DecodeBFLabelOperand(MCInst &Inst, unsigned val,
473                                          uint64_t Address, const void *Decoder);
474 static DecodeStatus DecodeBFAfterTargetOperand(MCInst &Inst, unsigned val,
475                                                uint64_t Address,
476                                                const void *Decoder);
477 static DecodeStatus DecodePredNoALOperand(MCInst &Inst, unsigned Val,
478                                           uint64_t Address,
479                                           const void *Decoder);
480 static DecodeStatus DecodeLOLoop(MCInst &Inst, unsigned Insn, uint64_t Address,
481                                  const void *Decoder);
482 static DecodeStatus DecodeLongShiftOperand(MCInst &Inst, unsigned Val,
483                                            uint64_t Address,
484                                            const void *Decoder);
485 static DecodeStatus DecodeVSCCLRM(MCInst &Inst, unsigned Insn, uint64_t Address,
486                                   const void *Decoder);
487 static DecodeStatus DecodeVPTMaskOperand(MCInst &Inst, unsigned Val,
488                                          uint64_t Address, const void *Decoder);
489 static DecodeStatus DecodeVpredROperand(MCInst &Inst, unsigned Val,
490                                         uint64_t Address, const void *Decoder);
491 static DecodeStatus DecodeRestrictedIPredicateOperand(MCInst &Inst, unsigned Val,
492                                                      uint64_t Address,
493                                                      const void *Decoder);
494 static DecodeStatus DecodeRestrictedSPredicateOperand(MCInst &Inst, unsigned Val,
495                                                      uint64_t Address,
496                                                      const void *Decoder);
497 static DecodeStatus DecodeRestrictedUPredicateOperand(MCInst &Inst, unsigned Val,
498                                                      uint64_t Address,
499                                                      const void *Decoder);
500 static DecodeStatus DecodeRestrictedFPPredicateOperand(MCInst &Inst,
501                                                        unsigned Val,
502                                                        uint64_t Address,
503                                                        const void *Decoder);
504 template<bool Writeback>
505 static DecodeStatus DecodeVSTRVLDR_SYSREG(MCInst &Inst, unsigned Insn,
506                                           uint64_t Address,
507                                           const void *Decoder);
508 template<unsigned MinLog, unsigned MaxLog>
509 static DecodeStatus DecodePowerTwoOperand(MCInst &Inst, unsigned Val,
510                                           uint64_t Address,
511                                           const void *Decoder);
512 template <int shift>
513 static DecodeStatus DecodeExpandedImmOperand(MCInst &Inst, unsigned Val,
514                                              uint64_t Address,
515                                              const void *Decoder);
516 template<unsigned start>
517 static DecodeStatus DecodeMVEPairVectorIndexOperand(MCInst &Inst, unsigned Val,
518                                                     uint64_t Address,
519                                                     const void *Decoder);
520 static DecodeStatus DecodeMVEVMOVQtoDReg(MCInst &Inst, unsigned Insn,
521                                          uint64_t Address,
522                                          const void *Decoder);
523 static DecodeStatus DecodeMVEVMOVDRegtoQ(MCInst &Inst, unsigned Insn,
524                                          uint64_t Address,
525                                          const void *Decoder);
526 static DecodeStatus DecodeMVEVCVTt1fp(MCInst &Inst, unsigned Insn,
527                                       uint64_t Address, const void *Decoder);
528 typedef DecodeStatus OperandDecoder(MCInst &Inst, unsigned Val,
529                                     uint64_t Address, const void *Decoder);
530 template<bool scalar, OperandDecoder predicate_decoder>
531 static DecodeStatus DecodeMVEVCMP(MCInst &Inst, unsigned Insn,
532                                   uint64_t Address, const void *Decoder);
533 static DecodeStatus DecodeMveVCTP(MCInst &Inst, unsigned Insn,
534                                   uint64_t Address, const void *Decoder);
535 static DecodeStatus DecodeMVEOverlappingLongShift(MCInst &Inst, unsigned Insn,
536                                                   uint64_t Address,
537                                                   const void *Decoder);
538 #include "ARMGenDisassemblerTables.inc"
539 
540 static MCDisassembler *createARMDisassembler(const Target &T,
541                                              const MCSubtargetInfo &STI,
542                                              MCContext &Ctx) {
543   return new ARMDisassembler(STI, Ctx);
544 }
545 
546 // Post-decoding checks
547 static DecodeStatus checkDecodedInstruction(MCInst &MI, uint64_t &Size,
548                                             uint64_t Address, raw_ostream &OS,
549                                             raw_ostream &CS,
550                                             uint32_t Insn,
551                                             DecodeStatus Result) {
552   switch (MI.getOpcode()) {
553     case ARM::HVC: {
554       // HVC is undefined if condition = 0xf otherwise upredictable
555       // if condition != 0xe
556       uint32_t Cond = (Insn >> 28) & 0xF;
557       if (Cond == 0xF)
558         return MCDisassembler::Fail;
559       if (Cond != 0xE)
560         return MCDisassembler::SoftFail;
561       return Result;
562     }
563     case ARM::t2ADDri:
564     case ARM::t2ADDri12:
565     case ARM::t2ADDrr:
566     case ARM::t2ADDrs:
567     case ARM::t2SUBri:
568     case ARM::t2SUBri12:
569     case ARM::t2SUBrr:
570     case ARM::t2SUBrs:
571       if (MI.getOperand(0).getReg() == ARM::SP &&
572           MI.getOperand(1).getReg() != ARM::SP)
573         return MCDisassembler::SoftFail;
574       return Result;
575     default: return Result;
576   }
577 }
578 
579 DecodeStatus ARMDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
580                                              ArrayRef<uint8_t> Bytes,
581                                              uint64_t Address, raw_ostream &OS,
582                                              raw_ostream &CS) const {
583   if (STI.getFeatureBits()[ARM::ModeThumb])
584     return getThumbInstruction(MI, Size, Bytes, Address, OS, CS);
585   return getARMInstruction(MI, Size, Bytes, Address, OS, CS);
586 }
587 
588 DecodeStatus ARMDisassembler::getARMInstruction(MCInst &MI, uint64_t &Size,
589                                                 ArrayRef<uint8_t> Bytes,
590                                                 uint64_t Address,
591                                                 raw_ostream &OS,
592                                                 raw_ostream &CS) const {
593   CommentStream = &CS;
594 
595   assert(!STI.getFeatureBits()[ARM::ModeThumb] &&
596          "Asked to disassemble an ARM instruction but Subtarget is in Thumb "
597          "mode!");
598 
599   // We want to read exactly 4 bytes of data.
600   if (Bytes.size() < 4) {
601     Size = 0;
602     return MCDisassembler::Fail;
603   }
604 
605   // Encoded as a small-endian 32-bit word in the stream.
606   uint32_t Insn =
607       (Bytes[3] << 24) | (Bytes[2] << 16) | (Bytes[1] << 8) | (Bytes[0] << 0);
608 
609   // Calling the auto-generated decoder function.
610   DecodeStatus Result =
611       decodeInstruction(DecoderTableARM32, MI, Insn, Address, this, STI);
612   if (Result != MCDisassembler::Fail) {
613     Size = 4;
614     return checkDecodedInstruction(MI, Size, Address, OS, CS, Insn, Result);
615   }
616 
617   struct DecodeTable {
618     const uint8_t *P;
619     bool DecodePred;
620   };
621 
622   const DecodeTable Tables[] = {
623       {DecoderTableVFP32, false},      {DecoderTableVFPV832, false},
624       {DecoderTableNEONData32, true},  {DecoderTableNEONLoadStore32, true},
625       {DecoderTableNEONDup32, true},   {DecoderTablev8NEON32, false},
626       {DecoderTablev8Crypto32, false},
627   };
628 
629   for (auto Table : Tables) {
630     Result = decodeInstruction(Table.P, MI, Insn, Address, this, STI);
631     if (Result != MCDisassembler::Fail) {
632       Size = 4;
633       // Add a fake predicate operand, because we share these instruction
634       // definitions with Thumb2 where these instructions are predicable.
635       if (Table.DecodePred && !DecodePredicateOperand(MI, 0xE, Address, this))
636         return MCDisassembler::Fail;
637       return Result;
638     }
639   }
640 
641   Result =
642       decodeInstruction(DecoderTableCoProc32, MI, Insn, Address, this, STI);
643   if (Result != MCDisassembler::Fail) {
644     Size = 4;
645     return checkDecodedInstruction(MI, Size, Address, OS, CS, Insn, Result);
646   }
647 
648   Size = 4;
649   return MCDisassembler::Fail;
650 }
651 
652 namespace llvm {
653 
654 extern const MCInstrDesc ARMInsts[];
655 
656 } // end namespace llvm
657 
658 /// tryAddingSymbolicOperand - trys to add a symbolic operand in place of the
659 /// immediate Value in the MCInst.  The immediate Value has had any PC
660 /// adjustment made by the caller.  If the instruction is a branch instruction
661 /// then isBranch is true, else false.  If the getOpInfo() function was set as
662 /// part of the setupForSymbolicDisassembly() call then that function is called
663 /// to get any symbolic information at the Address for this instruction.  If
664 /// that returns non-zero then the symbolic information it returns is used to
665 /// create an MCExpr and that is added as an operand to the MCInst.  If
666 /// getOpInfo() returns zero and isBranch is true then a symbol look up for
667 /// Value is done and if a symbol is found an MCExpr is created with that, else
668 /// an MCExpr with Value is created.  This function returns true if it adds an
669 /// operand to the MCInst and false otherwise.
670 static bool tryAddingSymbolicOperand(uint64_t Address, int32_t Value,
671                                      bool isBranch, uint64_t InstSize,
672                                      MCInst &MI, const void *Decoder) {
673   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
674   // FIXME: Does it make sense for value to be negative?
675   return Dis->tryAddingSymbolicOperand(MI, (uint32_t)Value, Address, isBranch,
676                                        /* Offset */ 0, InstSize);
677 }
678 
679 /// tryAddingPcLoadReferenceComment - trys to add a comment as to what is being
680 /// referenced by a load instruction with the base register that is the Pc.
681 /// These can often be values in a literal pool near the Address of the
682 /// instruction.  The Address of the instruction and its immediate Value are
683 /// used as a possible literal pool entry.  The SymbolLookUp call back will
684 /// return the name of a symbol referenced by the literal pool's entry if
685 /// the referenced address is that of a symbol.  Or it will return a pointer to
686 /// a literal 'C' string if the referenced address of the literal pool's entry
687 /// is an address into a section with 'C' string literals.
688 static void tryAddingPcLoadReferenceComment(uint64_t Address, int Value,
689                                             const void *Decoder) {
690   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
691   Dis->tryAddingPcLoadReferenceComment(Value, Address);
692 }
693 
694 // Thumb1 instructions don't have explicit S bits.  Rather, they
695 // implicitly set CPSR.  Since it's not represented in the encoding, the
696 // auto-generated decoder won't inject the CPSR operand.  We need to fix
697 // that as a post-pass.
698 static void AddThumb1SBit(MCInst &MI, bool InITBlock) {
699   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
700   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
701   MCInst::iterator I = MI.begin();
702   for (unsigned i = 0; i < NumOps; ++i, ++I) {
703     if (I == MI.end()) break;
704     if (OpInfo[i].isOptionalDef() && OpInfo[i].RegClass == ARM::CCRRegClassID) {
705       if (i > 0 && OpInfo[i-1].isPredicate()) continue;
706       MI.insert(I, MCOperand::createReg(InITBlock ? 0 : ARM::CPSR));
707       return;
708     }
709   }
710 
711   MI.insert(I, MCOperand::createReg(InITBlock ? 0 : ARM::CPSR));
712 }
713 
714 static bool isVectorPredicable(unsigned Opcode) {
715   const MCOperandInfo *OpInfo = ARMInsts[Opcode].OpInfo;
716   unsigned short NumOps = ARMInsts[Opcode].NumOperands;
717   for (unsigned i = 0; i < NumOps; ++i) {
718     if (ARM::isVpred(OpInfo[i].OperandType))
719       return true;
720   }
721   return false;
722 }
723 
724 // Most Thumb instructions don't have explicit predicates in the
725 // encoding, but rather get their predicates from IT context.  We need
726 // to fix up the predicate operands using this context information as a
727 // post-pass.
728 MCDisassembler::DecodeStatus
729 ARMDisassembler::AddThumbPredicate(MCInst &MI) const {
730   MCDisassembler::DecodeStatus S = Success;
731 
732   const FeatureBitset &FeatureBits = getSubtargetInfo().getFeatureBits();
733 
734   // A few instructions actually have predicates encoded in them.  Don't
735   // try to overwrite it if we're seeing one of those.
736   switch (MI.getOpcode()) {
737     case ARM::tBcc:
738     case ARM::t2Bcc:
739     case ARM::tCBZ:
740     case ARM::tCBNZ:
741     case ARM::tCPS:
742     case ARM::t2CPS3p:
743     case ARM::t2CPS2p:
744     case ARM::t2CPS1p:
745     case ARM::t2CSEL:
746     case ARM::t2CSINC:
747     case ARM::t2CSINV:
748     case ARM::t2CSNEG:
749     case ARM::tMOVSr:
750     case ARM::tSETEND:
751       // Some instructions (mostly conditional branches) are not
752       // allowed in IT blocks.
753       if (ITBlock.instrInITBlock())
754         S = SoftFail;
755       else
756         return Success;
757       break;
758     case ARM::t2HINT:
759       if (MI.getOperand(0).getImm() == 0x10 && (FeatureBits[ARM::FeatureRAS]) != 0)
760         S = SoftFail;
761       break;
762     case ARM::tB:
763     case ARM::t2B:
764     case ARM::t2TBB:
765     case ARM::t2TBH:
766       // Some instructions (mostly unconditional branches) can
767       // only appears at the end of, or outside of, an IT.
768       if (ITBlock.instrInITBlock() && !ITBlock.instrLastInITBlock())
769         S = SoftFail;
770       break;
771     default:
772       break;
773   }
774 
775   // Warn on non-VPT predicable instruction in a VPT block and a VPT
776   // predicable instruction in an IT block
777   if ((!isVectorPredicable(MI.getOpcode()) && VPTBlock.instrInVPTBlock()) ||
778        (isVectorPredicable(MI.getOpcode()) && ITBlock.instrInITBlock()))
779     S = SoftFail;
780 
781   // If we're in an IT/VPT block, base the predicate on that.  Otherwise,
782   // assume a predicate of AL.
783   unsigned CC = ARMCC::AL;
784   unsigned VCC = ARMVCC::None;
785   if (ITBlock.instrInITBlock()) {
786     CC = ITBlock.getITCC();
787     ITBlock.advanceITState();
788   } else if (VPTBlock.instrInVPTBlock()) {
789     VCC = VPTBlock.getVPTPred();
790     VPTBlock.advanceVPTState();
791   }
792 
793   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
794   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
795 
796   MCInst::iterator CCI = MI.begin();
797   for (unsigned i = 0; i < NumOps; ++i, ++CCI) {
798     if (OpInfo[i].isPredicate() || CCI == MI.end()) break;
799   }
800 
801   if (ARMInsts[MI.getOpcode()].isPredicable()) {
802     CCI = MI.insert(CCI, MCOperand::createImm(CC));
803     ++CCI;
804     if (CC == ARMCC::AL)
805       MI.insert(CCI, MCOperand::createReg(0));
806     else
807       MI.insert(CCI, MCOperand::createReg(ARM::CPSR));
808   } else if (CC != ARMCC::AL) {
809     Check(S, SoftFail);
810   }
811 
812   MCInst::iterator VCCI = MI.begin();
813   unsigned VCCPos;
814   for (VCCPos = 0; VCCPos < NumOps; ++VCCPos, ++VCCI) {
815     if (ARM::isVpred(OpInfo[VCCPos].OperandType) || VCCI == MI.end()) break;
816   }
817 
818   if (isVectorPredicable(MI.getOpcode())) {
819     VCCI = MI.insert(VCCI, MCOperand::createImm(VCC));
820     ++VCCI;
821     if (VCC == ARMVCC::None)
822       MI.insert(VCCI, MCOperand::createReg(0));
823     else
824       MI.insert(VCCI, MCOperand::createReg(ARM::P0));
825     if (OpInfo[VCCPos].OperandType == ARM::OPERAND_VPRED_R) {
826       int TiedOp = ARMInsts[MI.getOpcode()].getOperandConstraint(
827         VCCPos + 2, MCOI::TIED_TO);
828       assert(TiedOp >= 0 &&
829              "Inactive register in vpred_r is not tied to an output!");
830       MI.insert(VCCI, MI.getOperand(TiedOp));
831     }
832   } else if (VCC != ARMVCC::None) {
833     Check(S, SoftFail);
834   }
835 
836   return S;
837 }
838 
839 // Thumb VFP instructions are a special case.  Because we share their
840 // encodings between ARM and Thumb modes, and they are predicable in ARM
841 // mode, the auto-generated decoder will give them an (incorrect)
842 // predicate operand.  We need to rewrite these operands based on the IT
843 // context as a post-pass.
844 void ARMDisassembler::UpdateThumbVFPPredicate(
845   DecodeStatus &S, MCInst &MI) const {
846   unsigned CC;
847   CC = ITBlock.getITCC();
848   if (CC == 0xF)
849     CC = ARMCC::AL;
850   if (ITBlock.instrInITBlock())
851     ITBlock.advanceITState();
852   else if (VPTBlock.instrInVPTBlock()) {
853     CC = VPTBlock.getVPTPred();
854     VPTBlock.advanceVPTState();
855   }
856 
857   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
858   MCInst::iterator I = MI.begin();
859   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
860   for (unsigned i = 0; i < NumOps; ++i, ++I) {
861     if (OpInfo[i].isPredicate() ) {
862       if (CC != ARMCC::AL && !ARMInsts[MI.getOpcode()].isPredicable())
863         Check(S, SoftFail);
864       I->setImm(CC);
865       ++I;
866       if (CC == ARMCC::AL)
867         I->setReg(0);
868       else
869         I->setReg(ARM::CPSR);
870       return;
871     }
872   }
873 }
874 
875 DecodeStatus ARMDisassembler::getThumbInstruction(MCInst &MI, uint64_t &Size,
876                                                   ArrayRef<uint8_t> Bytes,
877                                                   uint64_t Address,
878                                                   raw_ostream &OS,
879                                                   raw_ostream &CS) const {
880   CommentStream = &CS;
881 
882   assert(STI.getFeatureBits()[ARM::ModeThumb] &&
883          "Asked to disassemble in Thumb mode but Subtarget is in ARM mode!");
884 
885   // We want to read exactly 2 bytes of data.
886   if (Bytes.size() < 2) {
887     Size = 0;
888     return MCDisassembler::Fail;
889   }
890 
891   uint16_t Insn16 = (Bytes[1] << 8) | Bytes[0];
892   DecodeStatus Result =
893       decodeInstruction(DecoderTableThumb16, MI, Insn16, Address, this, STI);
894   if (Result != MCDisassembler::Fail) {
895     Size = 2;
896     Check(Result, AddThumbPredicate(MI));
897     return Result;
898   }
899 
900   Result = decodeInstruction(DecoderTableThumbSBit16, MI, Insn16, Address, this,
901                              STI);
902   if (Result) {
903     Size = 2;
904     bool InITBlock = ITBlock.instrInITBlock();
905     Check(Result, AddThumbPredicate(MI));
906     AddThumb1SBit(MI, InITBlock);
907     return Result;
908   }
909 
910   Result =
911       decodeInstruction(DecoderTableThumb216, MI, Insn16, Address, this, STI);
912   if (Result != MCDisassembler::Fail) {
913     Size = 2;
914 
915     // Nested IT blocks are UNPREDICTABLE.  Must be checked before we add
916     // the Thumb predicate.
917     if (MI.getOpcode() == ARM::t2IT && ITBlock.instrInITBlock())
918       Result = MCDisassembler::SoftFail;
919 
920     Check(Result, AddThumbPredicate(MI));
921 
922     // If we find an IT instruction, we need to parse its condition
923     // code and mask operands so that we can apply them correctly
924     // to the subsequent instructions.
925     if (MI.getOpcode() == ARM::t2IT) {
926       unsigned Firstcond = MI.getOperand(0).getImm();
927       unsigned Mask = MI.getOperand(1).getImm();
928       ITBlock.setITState(Firstcond, Mask);
929 
930       // An IT instruction that would give a 'NV' predicate is unpredictable.
931       if (Firstcond == ARMCC::AL && !isPowerOf2_32(Mask))
932         CS << "unpredictable IT predicate sequence";
933     }
934 
935     return Result;
936   }
937 
938   // We want to read exactly 4 bytes of data.
939   if (Bytes.size() < 4) {
940     Size = 0;
941     return MCDisassembler::Fail;
942   }
943 
944   uint32_t Insn32 =
945       (Bytes[3] << 8) | (Bytes[2] << 0) | (Bytes[1] << 24) | (Bytes[0] << 16);
946 
947   Result =
948       decodeInstruction(DecoderTableMVE32, MI, Insn32, Address, this, STI);
949   if (Result != MCDisassembler::Fail) {
950     Size = 4;
951 
952     // Nested VPT blocks are UNPREDICTABLE. Must be checked before we add
953     // the VPT predicate.
954     if (isVPTOpcode(MI.getOpcode()) && VPTBlock.instrInVPTBlock())
955       Result = MCDisassembler::SoftFail;
956 
957     Check(Result, AddThumbPredicate(MI));
958 
959     if (isVPTOpcode(MI.getOpcode())) {
960       unsigned Mask = MI.getOperand(0).getImm();
961       VPTBlock.setVPTState(Mask);
962     }
963 
964     return Result;
965   }
966 
967   Result =
968       decodeInstruction(DecoderTableThumb32, MI, Insn32, Address, this, STI);
969   if (Result != MCDisassembler::Fail) {
970     Size = 4;
971     bool InITBlock = ITBlock.instrInITBlock();
972     Check(Result, AddThumbPredicate(MI));
973     AddThumb1SBit(MI, InITBlock);
974     return Result;
975   }
976 
977   Result =
978       decodeInstruction(DecoderTableThumb232, MI, Insn32, Address, this, STI);
979   if (Result != MCDisassembler::Fail) {
980     Size = 4;
981     Check(Result, AddThumbPredicate(MI));
982     return checkDecodedInstruction(MI, Size, Address, OS, CS, Insn32, Result);
983   }
984 
985   if (fieldFromInstruction(Insn32, 28, 4) == 0xE) {
986     Result =
987         decodeInstruction(DecoderTableVFP32, MI, Insn32, Address, this, STI);
988     if (Result != MCDisassembler::Fail) {
989       Size = 4;
990       UpdateThumbVFPPredicate(Result, MI);
991       return Result;
992     }
993   }
994 
995   Result =
996       decodeInstruction(DecoderTableVFPV832, MI, Insn32, Address, this, STI);
997   if (Result != MCDisassembler::Fail) {
998     Size = 4;
999     return Result;
1000   }
1001 
1002   if (fieldFromInstruction(Insn32, 28, 4) == 0xE) {
1003     Result = decodeInstruction(DecoderTableNEONDup32, MI, Insn32, Address, this,
1004                                STI);
1005     if (Result != MCDisassembler::Fail) {
1006       Size = 4;
1007       Check(Result, AddThumbPredicate(MI));
1008       return Result;
1009     }
1010   }
1011 
1012   if (fieldFromInstruction(Insn32, 24, 8) == 0xF9) {
1013     uint32_t NEONLdStInsn = Insn32;
1014     NEONLdStInsn &= 0xF0FFFFFF;
1015     NEONLdStInsn |= 0x04000000;
1016     Result = decodeInstruction(DecoderTableNEONLoadStore32, MI, NEONLdStInsn,
1017                                Address, this, STI);
1018     if (Result != MCDisassembler::Fail) {
1019       Size = 4;
1020       Check(Result, AddThumbPredicate(MI));
1021       return Result;
1022     }
1023   }
1024 
1025   if (fieldFromInstruction(Insn32, 24, 4) == 0xF) {
1026     uint32_t NEONDataInsn = Insn32;
1027     NEONDataInsn &= 0xF0FFFFFF; // Clear bits 27-24
1028     NEONDataInsn |= (NEONDataInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
1029     NEONDataInsn |= 0x12000000; // Set bits 28 and 25
1030     Result = decodeInstruction(DecoderTableNEONData32, MI, NEONDataInsn,
1031                                Address, this, STI);
1032     if (Result != MCDisassembler::Fail) {
1033       Size = 4;
1034       Check(Result, AddThumbPredicate(MI));
1035       return Result;
1036     }
1037 
1038     uint32_t NEONCryptoInsn = Insn32;
1039     NEONCryptoInsn &= 0xF0FFFFFF; // Clear bits 27-24
1040     NEONCryptoInsn |= (NEONCryptoInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
1041     NEONCryptoInsn |= 0x12000000; // Set bits 28 and 25
1042     Result = decodeInstruction(DecoderTablev8Crypto32, MI, NEONCryptoInsn,
1043                                Address, this, STI);
1044     if (Result != MCDisassembler::Fail) {
1045       Size = 4;
1046       return Result;
1047     }
1048 
1049     uint32_t NEONv8Insn = Insn32;
1050     NEONv8Insn &= 0xF3FFFFFF; // Clear bits 27-26
1051     Result = decodeInstruction(DecoderTablev8NEON32, MI, NEONv8Insn, Address,
1052                                this, STI);
1053     if (Result != MCDisassembler::Fail) {
1054       Size = 4;
1055       return Result;
1056     }
1057   }
1058 
1059   Result =
1060       decodeInstruction(DecoderTableThumb2CoProc32, MI, Insn32, Address, this, STI);
1061   if (Result != MCDisassembler::Fail) {
1062     Size = 4;
1063     Check(Result, AddThumbPredicate(MI));
1064     return Result;
1065   }
1066 
1067   Size = 0;
1068   return MCDisassembler::Fail;
1069 }
1070 
1071 extern "C" void LLVMInitializeARMDisassembler() {
1072   TargetRegistry::RegisterMCDisassembler(getTheARMLETarget(),
1073                                          createARMDisassembler);
1074   TargetRegistry::RegisterMCDisassembler(getTheARMBETarget(),
1075                                          createARMDisassembler);
1076   TargetRegistry::RegisterMCDisassembler(getTheThumbLETarget(),
1077                                          createARMDisassembler);
1078   TargetRegistry::RegisterMCDisassembler(getTheThumbBETarget(),
1079                                          createARMDisassembler);
1080 }
1081 
1082 static const uint16_t GPRDecoderTable[] = {
1083   ARM::R0, ARM::R1, ARM::R2, ARM::R3,
1084   ARM::R4, ARM::R5, ARM::R6, ARM::R7,
1085   ARM::R8, ARM::R9, ARM::R10, ARM::R11,
1086   ARM::R12, ARM::SP, ARM::LR, ARM::PC
1087 };
1088 
1089 static const uint16_t CLRMGPRDecoderTable[] = {
1090   ARM::R0, ARM::R1, ARM::R2, ARM::R3,
1091   ARM::R4, ARM::R5, ARM::R6, ARM::R7,
1092   ARM::R8, ARM::R9, ARM::R10, ARM::R11,
1093   ARM::R12, 0, ARM::LR, ARM::APSR
1094 };
1095 
1096 static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1097                                    uint64_t Address, const void *Decoder) {
1098   if (RegNo > 15)
1099     return MCDisassembler::Fail;
1100 
1101   unsigned Register = GPRDecoderTable[RegNo];
1102   Inst.addOperand(MCOperand::createReg(Register));
1103   return MCDisassembler::Success;
1104 }
1105 
1106 static DecodeStatus DecodeCLRMGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1107                                                uint64_t Address,
1108                                                const void *Decoder) {
1109   if (RegNo > 15)
1110     return MCDisassembler::Fail;
1111 
1112   unsigned Register = CLRMGPRDecoderTable[RegNo];
1113   if (Register == 0)
1114     return MCDisassembler::Fail;
1115 
1116   Inst.addOperand(MCOperand::createReg(Register));
1117   return MCDisassembler::Success;
1118 }
1119 
1120 static DecodeStatus
1121 DecodeGPRnopcRegisterClass(MCInst &Inst, unsigned RegNo,
1122                            uint64_t Address, const void *Decoder) {
1123   DecodeStatus S = MCDisassembler::Success;
1124 
1125   if (RegNo == 15)
1126     S = MCDisassembler::SoftFail;
1127 
1128   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1129 
1130   return S;
1131 }
1132 
1133 static DecodeStatus
1134 DecodeGPRwithAPSRRegisterClass(MCInst &Inst, unsigned RegNo,
1135                                uint64_t Address, const void *Decoder) {
1136   DecodeStatus S = MCDisassembler::Success;
1137 
1138   if (RegNo == 15)
1139   {
1140     Inst.addOperand(MCOperand::createReg(ARM::APSR_NZCV));
1141     return MCDisassembler::Success;
1142   }
1143 
1144   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1145   return S;
1146 }
1147 
1148 static DecodeStatus
1149 DecodeGPRwithZRRegisterClass(MCInst &Inst, unsigned RegNo,
1150                              uint64_t Address, const void *Decoder) {
1151   DecodeStatus S = MCDisassembler::Success;
1152 
1153   if (RegNo == 15)
1154   {
1155     Inst.addOperand(MCOperand::createReg(ARM::ZR));
1156     return MCDisassembler::Success;
1157   }
1158 
1159   if (RegNo == 13)
1160     S = MCDisassembler::SoftFail;
1161 
1162   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1163   return S;
1164 }
1165 
1166 static DecodeStatus DecodetGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1167                                    uint64_t Address, const void *Decoder) {
1168   if (RegNo > 7)
1169     return MCDisassembler::Fail;
1170   return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
1171 }
1172 
1173 static const uint16_t GPRPairDecoderTable[] = {
1174   ARM::R0_R1, ARM::R2_R3,   ARM::R4_R5,  ARM::R6_R7,
1175   ARM::R8_R9, ARM::R10_R11, ARM::R12_SP
1176 };
1177 
1178 static DecodeStatus DecodeGPRPairRegisterClass(MCInst &Inst, unsigned RegNo,
1179                                    uint64_t Address, const void *Decoder) {
1180   DecodeStatus S = MCDisassembler::Success;
1181 
1182   if (RegNo > 13)
1183     return MCDisassembler::Fail;
1184 
1185   if ((RegNo & 1) || RegNo == 0xe)
1186      S = MCDisassembler::SoftFail;
1187 
1188   unsigned RegisterPair = GPRPairDecoderTable[RegNo/2];
1189   Inst.addOperand(MCOperand::createReg(RegisterPair));
1190   return S;
1191 }
1192 
1193 static DecodeStatus DecodetcGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1194                                    uint64_t Address, const void *Decoder) {
1195   unsigned Register = 0;
1196   switch (RegNo) {
1197     case 0:
1198       Register = ARM::R0;
1199       break;
1200     case 1:
1201       Register = ARM::R1;
1202       break;
1203     case 2:
1204       Register = ARM::R2;
1205       break;
1206     case 3:
1207       Register = ARM::R3;
1208       break;
1209     case 9:
1210       Register = ARM::R9;
1211       break;
1212     case 12:
1213       Register = ARM::R12;
1214       break;
1215     default:
1216       return MCDisassembler::Fail;
1217     }
1218 
1219   Inst.addOperand(MCOperand::createReg(Register));
1220   return MCDisassembler::Success;
1221 }
1222 
1223 static DecodeStatus DecoderGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1224                                    uint64_t Address, const void *Decoder) {
1225   DecodeStatus S = MCDisassembler::Success;
1226 
1227   const FeatureBitset &featureBits =
1228     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1229 
1230   if ((RegNo == 13 && !featureBits[ARM::HasV8Ops]) || RegNo == 15)
1231     S = MCDisassembler::SoftFail;
1232 
1233   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1234   return S;
1235 }
1236 
1237 static const uint16_t SPRDecoderTable[] = {
1238      ARM::S0,  ARM::S1,  ARM::S2,  ARM::S3,
1239      ARM::S4,  ARM::S5,  ARM::S6,  ARM::S7,
1240      ARM::S8,  ARM::S9, ARM::S10, ARM::S11,
1241     ARM::S12, ARM::S13, ARM::S14, ARM::S15,
1242     ARM::S16, ARM::S17, ARM::S18, ARM::S19,
1243     ARM::S20, ARM::S21, ARM::S22, ARM::S23,
1244     ARM::S24, ARM::S25, ARM::S26, ARM::S27,
1245     ARM::S28, ARM::S29, ARM::S30, ARM::S31
1246 };
1247 
1248 static DecodeStatus DecodeSPRRegisterClass(MCInst &Inst, unsigned RegNo,
1249                                    uint64_t Address, const void *Decoder) {
1250   if (RegNo > 31)
1251     return MCDisassembler::Fail;
1252 
1253   unsigned Register = SPRDecoderTable[RegNo];
1254   Inst.addOperand(MCOperand::createReg(Register));
1255   return MCDisassembler::Success;
1256 }
1257 
1258 static DecodeStatus DecodeHPRRegisterClass(MCInst &Inst, unsigned RegNo,
1259                                    uint64_t Address, const void *Decoder) {
1260   return DecodeSPRRegisterClass(Inst, RegNo, Address, Decoder);
1261 }
1262 
1263 static const uint16_t DPRDecoderTable[] = {
1264      ARM::D0,  ARM::D1,  ARM::D2,  ARM::D3,
1265      ARM::D4,  ARM::D5,  ARM::D6,  ARM::D7,
1266      ARM::D8,  ARM::D9, ARM::D10, ARM::D11,
1267     ARM::D12, ARM::D13, ARM::D14, ARM::D15,
1268     ARM::D16, ARM::D17, ARM::D18, ARM::D19,
1269     ARM::D20, ARM::D21, ARM::D22, ARM::D23,
1270     ARM::D24, ARM::D25, ARM::D26, ARM::D27,
1271     ARM::D28, ARM::D29, ARM::D30, ARM::D31
1272 };
1273 
1274 static DecodeStatus DecodeDPRRegisterClass(MCInst &Inst, unsigned RegNo,
1275                                    uint64_t Address, const void *Decoder) {
1276   const FeatureBitset &featureBits =
1277     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1278 
1279   bool hasD32 = featureBits[ARM::FeatureD32];
1280 
1281   if (RegNo > 31 || (!hasD32 && RegNo > 15))
1282     return MCDisassembler::Fail;
1283 
1284   unsigned Register = DPRDecoderTable[RegNo];
1285   Inst.addOperand(MCOperand::createReg(Register));
1286   return MCDisassembler::Success;
1287 }
1288 
1289 static DecodeStatus DecodeDPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
1290                                    uint64_t Address, const void *Decoder) {
1291   if (RegNo > 7)
1292     return MCDisassembler::Fail;
1293   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
1294 }
1295 
1296 static DecodeStatus DecodeSPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
1297                                    uint64_t Address, const void *Decoder) {
1298   if (RegNo > 15)
1299     return MCDisassembler::Fail;
1300   return DecodeSPRRegisterClass(Inst, RegNo, Address, Decoder);
1301 }
1302 
1303 static DecodeStatus
1304 DecodeDPR_VFP2RegisterClass(MCInst &Inst, unsigned RegNo,
1305                             uint64_t Address, const void *Decoder) {
1306   if (RegNo > 15)
1307     return MCDisassembler::Fail;
1308   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
1309 }
1310 
1311 static const uint16_t QPRDecoderTable[] = {
1312      ARM::Q0,  ARM::Q1,  ARM::Q2,  ARM::Q3,
1313      ARM::Q4,  ARM::Q5,  ARM::Q6,  ARM::Q7,
1314      ARM::Q8,  ARM::Q9, ARM::Q10, ARM::Q11,
1315     ARM::Q12, ARM::Q13, ARM::Q14, ARM::Q15
1316 };
1317 
1318 static DecodeStatus DecodeQPRRegisterClass(MCInst &Inst, unsigned RegNo,
1319                                    uint64_t Address, const void *Decoder) {
1320   if (RegNo > 31 || (RegNo & 1) != 0)
1321     return MCDisassembler::Fail;
1322   RegNo >>= 1;
1323 
1324   unsigned Register = QPRDecoderTable[RegNo];
1325   Inst.addOperand(MCOperand::createReg(Register));
1326   return MCDisassembler::Success;
1327 }
1328 
1329 static const uint16_t DPairDecoderTable[] = {
1330   ARM::Q0,  ARM::D1_D2,   ARM::Q1,  ARM::D3_D4,   ARM::Q2,  ARM::D5_D6,
1331   ARM::Q3,  ARM::D7_D8,   ARM::Q4,  ARM::D9_D10,  ARM::Q5,  ARM::D11_D12,
1332   ARM::Q6,  ARM::D13_D14, ARM::Q7,  ARM::D15_D16, ARM::Q8,  ARM::D17_D18,
1333   ARM::Q9,  ARM::D19_D20, ARM::Q10, ARM::D21_D22, ARM::Q11, ARM::D23_D24,
1334   ARM::Q12, ARM::D25_D26, ARM::Q13, ARM::D27_D28, ARM::Q14, ARM::D29_D30,
1335   ARM::Q15
1336 };
1337 
1338 static DecodeStatus DecodeDPairRegisterClass(MCInst &Inst, unsigned RegNo,
1339                                    uint64_t Address, const void *Decoder) {
1340   if (RegNo > 30)
1341     return MCDisassembler::Fail;
1342 
1343   unsigned Register = DPairDecoderTable[RegNo];
1344   Inst.addOperand(MCOperand::createReg(Register));
1345   return MCDisassembler::Success;
1346 }
1347 
1348 static const uint16_t DPairSpacedDecoderTable[] = {
1349   ARM::D0_D2,   ARM::D1_D3,   ARM::D2_D4,   ARM::D3_D5,
1350   ARM::D4_D6,   ARM::D5_D7,   ARM::D6_D8,   ARM::D7_D9,
1351   ARM::D8_D10,  ARM::D9_D11,  ARM::D10_D12, ARM::D11_D13,
1352   ARM::D12_D14, ARM::D13_D15, ARM::D14_D16, ARM::D15_D17,
1353   ARM::D16_D18, ARM::D17_D19, ARM::D18_D20, ARM::D19_D21,
1354   ARM::D20_D22, ARM::D21_D23, ARM::D22_D24, ARM::D23_D25,
1355   ARM::D24_D26, ARM::D25_D27, ARM::D26_D28, ARM::D27_D29,
1356   ARM::D28_D30, ARM::D29_D31
1357 };
1358 
1359 static DecodeStatus DecodeDPairSpacedRegisterClass(MCInst &Inst,
1360                                                    unsigned RegNo,
1361                                                    uint64_t Address,
1362                                                    const void *Decoder) {
1363   if (RegNo > 29)
1364     return MCDisassembler::Fail;
1365 
1366   unsigned Register = DPairSpacedDecoderTable[RegNo];
1367   Inst.addOperand(MCOperand::createReg(Register));
1368   return MCDisassembler::Success;
1369 }
1370 
1371 static DecodeStatus DecodePredicateOperand(MCInst &Inst, unsigned Val,
1372                                uint64_t Address, const void *Decoder) {
1373   DecodeStatus S = MCDisassembler::Success;
1374   if (Val == 0xF) return MCDisassembler::Fail;
1375   // AL predicate is not allowed on Thumb1 branches.
1376   if (Inst.getOpcode() == ARM::tBcc && Val == 0xE)
1377     return MCDisassembler::Fail;
1378   if (Val != ARMCC::AL && !ARMInsts[Inst.getOpcode()].isPredicable())
1379     Check(S, MCDisassembler::SoftFail);
1380   Inst.addOperand(MCOperand::createImm(Val));
1381   if (Val == ARMCC::AL) {
1382     Inst.addOperand(MCOperand::createReg(0));
1383   } else
1384     Inst.addOperand(MCOperand::createReg(ARM::CPSR));
1385   return S;
1386 }
1387 
1388 static DecodeStatus DecodeCCOutOperand(MCInst &Inst, unsigned Val,
1389                                uint64_t Address, const void *Decoder) {
1390   if (Val)
1391     Inst.addOperand(MCOperand::createReg(ARM::CPSR));
1392   else
1393     Inst.addOperand(MCOperand::createReg(0));
1394   return MCDisassembler::Success;
1395 }
1396 
1397 static DecodeStatus DecodeSORegImmOperand(MCInst &Inst, unsigned Val,
1398                                uint64_t Address, const void *Decoder) {
1399   DecodeStatus S = MCDisassembler::Success;
1400 
1401   unsigned Rm = fieldFromInstruction(Val, 0, 4);
1402   unsigned type = fieldFromInstruction(Val, 5, 2);
1403   unsigned imm = fieldFromInstruction(Val, 7, 5);
1404 
1405   // Register-immediate
1406   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
1407     return MCDisassembler::Fail;
1408 
1409   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1410   switch (type) {
1411     case 0:
1412       Shift = ARM_AM::lsl;
1413       break;
1414     case 1:
1415       Shift = ARM_AM::lsr;
1416       break;
1417     case 2:
1418       Shift = ARM_AM::asr;
1419       break;
1420     case 3:
1421       Shift = ARM_AM::ror;
1422       break;
1423   }
1424 
1425   if (Shift == ARM_AM::ror && imm == 0)
1426     Shift = ARM_AM::rrx;
1427 
1428   unsigned Op = Shift | (imm << 3);
1429   Inst.addOperand(MCOperand::createImm(Op));
1430 
1431   return S;
1432 }
1433 
1434 static DecodeStatus DecodeSORegRegOperand(MCInst &Inst, unsigned Val,
1435                                uint64_t Address, const void *Decoder) {
1436   DecodeStatus S = MCDisassembler::Success;
1437 
1438   unsigned Rm = fieldFromInstruction(Val, 0, 4);
1439   unsigned type = fieldFromInstruction(Val, 5, 2);
1440   unsigned Rs = fieldFromInstruction(Val, 8, 4);
1441 
1442   // Register-register
1443   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1444     return MCDisassembler::Fail;
1445   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rs, Address, Decoder)))
1446     return MCDisassembler::Fail;
1447 
1448   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1449   switch (type) {
1450     case 0:
1451       Shift = ARM_AM::lsl;
1452       break;
1453     case 1:
1454       Shift = ARM_AM::lsr;
1455       break;
1456     case 2:
1457       Shift = ARM_AM::asr;
1458       break;
1459     case 3:
1460       Shift = ARM_AM::ror;
1461       break;
1462   }
1463 
1464   Inst.addOperand(MCOperand::createImm(Shift));
1465 
1466   return S;
1467 }
1468 
1469 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Val,
1470                                  uint64_t Address, const void *Decoder) {
1471   DecodeStatus S = MCDisassembler::Success;
1472 
1473   bool NeedDisjointWriteback = false;
1474   unsigned WritebackReg = 0;
1475   bool CLRM = false;
1476   switch (Inst.getOpcode()) {
1477   default:
1478     break;
1479   case ARM::LDMIA_UPD:
1480   case ARM::LDMDB_UPD:
1481   case ARM::LDMIB_UPD:
1482   case ARM::LDMDA_UPD:
1483   case ARM::t2LDMIA_UPD:
1484   case ARM::t2LDMDB_UPD:
1485   case ARM::t2STMIA_UPD:
1486   case ARM::t2STMDB_UPD:
1487     NeedDisjointWriteback = true;
1488     WritebackReg = Inst.getOperand(0).getReg();
1489     break;
1490   case ARM::t2CLRM:
1491     CLRM = true;
1492     break;
1493   }
1494 
1495   // Empty register lists are not allowed.
1496   if (Val == 0) return MCDisassembler::Fail;
1497   for (unsigned i = 0; i < 16; ++i) {
1498     if (Val & (1 << i)) {
1499       if (CLRM) {
1500         if (!Check(S, DecodeCLRMGPRRegisterClass(Inst, i, Address, Decoder))) {
1501           return MCDisassembler::Fail;
1502         }
1503       } else {
1504         if (!Check(S, DecodeGPRRegisterClass(Inst, i, Address, Decoder)))
1505           return MCDisassembler::Fail;
1506         // Writeback not allowed if Rn is in the target list.
1507         if (NeedDisjointWriteback && WritebackReg == Inst.end()[-1].getReg())
1508           Check(S, MCDisassembler::SoftFail);
1509       }
1510     }
1511   }
1512 
1513   return S;
1514 }
1515 
1516 static DecodeStatus DecodeSPRRegListOperand(MCInst &Inst, unsigned Val,
1517                                  uint64_t Address, const void *Decoder) {
1518   DecodeStatus S = MCDisassembler::Success;
1519 
1520   unsigned Vd = fieldFromInstruction(Val, 8, 5);
1521   unsigned regs = fieldFromInstruction(Val, 0, 8);
1522 
1523   // In case of unpredictable encoding, tweak the operands.
1524   if (regs == 0 || (Vd + regs) > 32) {
1525     regs = Vd + regs > 32 ? 32 - Vd : regs;
1526     regs = std::max( 1u, regs);
1527     S = MCDisassembler::SoftFail;
1528   }
1529 
1530   if (!Check(S, DecodeSPRRegisterClass(Inst, Vd, Address, Decoder)))
1531     return MCDisassembler::Fail;
1532   for (unsigned i = 0; i < (regs - 1); ++i) {
1533     if (!Check(S, DecodeSPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1534       return MCDisassembler::Fail;
1535   }
1536 
1537   return S;
1538 }
1539 
1540 static DecodeStatus DecodeDPRRegListOperand(MCInst &Inst, unsigned Val,
1541                                  uint64_t Address, const void *Decoder) {
1542   DecodeStatus S = MCDisassembler::Success;
1543 
1544   unsigned Vd = fieldFromInstruction(Val, 8, 5);
1545   unsigned regs = fieldFromInstruction(Val, 1, 7);
1546 
1547   // In case of unpredictable encoding, tweak the operands.
1548   if (regs == 0 || regs > 16 || (Vd + regs) > 32) {
1549     regs = Vd + regs > 32 ? 32 - Vd : regs;
1550     regs = std::max( 1u, regs);
1551     regs = std::min(16u, regs);
1552     S = MCDisassembler::SoftFail;
1553   }
1554 
1555   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
1556       return MCDisassembler::Fail;
1557   for (unsigned i = 0; i < (regs - 1); ++i) {
1558     if (!Check(S, DecodeDPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1559       return MCDisassembler::Fail;
1560   }
1561 
1562   return S;
1563 }
1564 
1565 static DecodeStatus DecodeBitfieldMaskOperand(MCInst &Inst, unsigned Val,
1566                                       uint64_t Address, const void *Decoder) {
1567   // This operand encodes a mask of contiguous zeros between a specified MSB
1568   // and LSB.  To decode it, we create the mask of all bits MSB-and-lower,
1569   // the mask of all bits LSB-and-lower, and then xor them to create
1570   // the mask of that's all ones on [msb, lsb].  Finally we not it to
1571   // create the final mask.
1572   unsigned msb = fieldFromInstruction(Val, 5, 5);
1573   unsigned lsb = fieldFromInstruction(Val, 0, 5);
1574 
1575   DecodeStatus S = MCDisassembler::Success;
1576   if (lsb > msb) {
1577     Check(S, MCDisassembler::SoftFail);
1578     // The check above will cause the warning for the "potentially undefined
1579     // instruction encoding" but we can't build a bad MCOperand value here
1580     // with a lsb > msb or else printing the MCInst will cause a crash.
1581     lsb = msb;
1582   }
1583 
1584   uint32_t msb_mask = 0xFFFFFFFF;
1585   if (msb != 31) msb_mask = (1U << (msb+1)) - 1;
1586   uint32_t lsb_mask = (1U << lsb) - 1;
1587 
1588   Inst.addOperand(MCOperand::createImm(~(msb_mask ^ lsb_mask)));
1589   return S;
1590 }
1591 
1592 static DecodeStatus DecodeCopMemInstruction(MCInst &Inst, unsigned Insn,
1593                                   uint64_t Address, const void *Decoder) {
1594   DecodeStatus S = MCDisassembler::Success;
1595 
1596   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1597   unsigned CRd = fieldFromInstruction(Insn, 12, 4);
1598   unsigned coproc = fieldFromInstruction(Insn, 8, 4);
1599   unsigned imm = fieldFromInstruction(Insn, 0, 8);
1600   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1601   unsigned U = fieldFromInstruction(Insn, 23, 1);
1602   const FeatureBitset &featureBits =
1603     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1604 
1605   switch (Inst.getOpcode()) {
1606     case ARM::LDC_OFFSET:
1607     case ARM::LDC_PRE:
1608     case ARM::LDC_POST:
1609     case ARM::LDC_OPTION:
1610     case ARM::LDCL_OFFSET:
1611     case ARM::LDCL_PRE:
1612     case ARM::LDCL_POST:
1613     case ARM::LDCL_OPTION:
1614     case ARM::STC_OFFSET:
1615     case ARM::STC_PRE:
1616     case ARM::STC_POST:
1617     case ARM::STC_OPTION:
1618     case ARM::STCL_OFFSET:
1619     case ARM::STCL_PRE:
1620     case ARM::STCL_POST:
1621     case ARM::STCL_OPTION:
1622     case ARM::t2LDC_OFFSET:
1623     case ARM::t2LDC_PRE:
1624     case ARM::t2LDC_POST:
1625     case ARM::t2LDC_OPTION:
1626     case ARM::t2LDCL_OFFSET:
1627     case ARM::t2LDCL_PRE:
1628     case ARM::t2LDCL_POST:
1629     case ARM::t2LDCL_OPTION:
1630     case ARM::t2STC_OFFSET:
1631     case ARM::t2STC_PRE:
1632     case ARM::t2STC_POST:
1633     case ARM::t2STC_OPTION:
1634     case ARM::t2STCL_OFFSET:
1635     case ARM::t2STCL_PRE:
1636     case ARM::t2STCL_POST:
1637     case ARM::t2STCL_OPTION:
1638     case ARM::t2LDC2_OFFSET:
1639     case ARM::t2LDC2L_OFFSET:
1640     case ARM::t2LDC2_PRE:
1641     case ARM::t2LDC2L_PRE:
1642     case ARM::t2STC2_OFFSET:
1643     case ARM::t2STC2L_OFFSET:
1644     case ARM::t2STC2_PRE:
1645     case ARM::t2STC2L_PRE:
1646     case ARM::LDC2_OFFSET:
1647     case ARM::LDC2L_OFFSET:
1648     case ARM::LDC2_PRE:
1649     case ARM::LDC2L_PRE:
1650     case ARM::STC2_OFFSET:
1651     case ARM::STC2L_OFFSET:
1652     case ARM::STC2_PRE:
1653     case ARM::STC2L_PRE:
1654     case ARM::t2LDC2_OPTION:
1655     case ARM::t2STC2_OPTION:
1656     case ARM::t2LDC2_POST:
1657     case ARM::t2LDC2L_POST:
1658     case ARM::t2STC2_POST:
1659     case ARM::t2STC2L_POST:
1660     case ARM::LDC2_POST:
1661     case ARM::LDC2L_POST:
1662     case ARM::STC2_POST:
1663     case ARM::STC2L_POST:
1664       if (coproc == 0xA || coproc == 0xB ||
1665           (featureBits[ARM::HasV8_1MMainlineOps] &&
1666            (coproc == 0x8 || coproc == 0x9 || coproc == 0xA || coproc == 0xB ||
1667             coproc == 0xE || coproc == 0xF)))
1668         return MCDisassembler::Fail;
1669       break;
1670     default:
1671       break;
1672   }
1673 
1674   if (featureBits[ARM::HasV8Ops] && (coproc != 14))
1675     return MCDisassembler::Fail;
1676 
1677   Inst.addOperand(MCOperand::createImm(coproc));
1678   Inst.addOperand(MCOperand::createImm(CRd));
1679   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1680     return MCDisassembler::Fail;
1681 
1682   switch (Inst.getOpcode()) {
1683     case ARM::t2LDC2_OFFSET:
1684     case ARM::t2LDC2L_OFFSET:
1685     case ARM::t2LDC2_PRE:
1686     case ARM::t2LDC2L_PRE:
1687     case ARM::t2STC2_OFFSET:
1688     case ARM::t2STC2L_OFFSET:
1689     case ARM::t2STC2_PRE:
1690     case ARM::t2STC2L_PRE:
1691     case ARM::LDC2_OFFSET:
1692     case ARM::LDC2L_OFFSET:
1693     case ARM::LDC2_PRE:
1694     case ARM::LDC2L_PRE:
1695     case ARM::STC2_OFFSET:
1696     case ARM::STC2L_OFFSET:
1697     case ARM::STC2_PRE:
1698     case ARM::STC2L_PRE:
1699     case ARM::t2LDC_OFFSET:
1700     case ARM::t2LDCL_OFFSET:
1701     case ARM::t2LDC_PRE:
1702     case ARM::t2LDCL_PRE:
1703     case ARM::t2STC_OFFSET:
1704     case ARM::t2STCL_OFFSET:
1705     case ARM::t2STC_PRE:
1706     case ARM::t2STCL_PRE:
1707     case ARM::LDC_OFFSET:
1708     case ARM::LDCL_OFFSET:
1709     case ARM::LDC_PRE:
1710     case ARM::LDCL_PRE:
1711     case ARM::STC_OFFSET:
1712     case ARM::STCL_OFFSET:
1713     case ARM::STC_PRE:
1714     case ARM::STCL_PRE:
1715       imm = ARM_AM::getAM5Opc(U ? ARM_AM::add : ARM_AM::sub, imm);
1716       Inst.addOperand(MCOperand::createImm(imm));
1717       break;
1718     case ARM::t2LDC2_POST:
1719     case ARM::t2LDC2L_POST:
1720     case ARM::t2STC2_POST:
1721     case ARM::t2STC2L_POST:
1722     case ARM::LDC2_POST:
1723     case ARM::LDC2L_POST:
1724     case ARM::STC2_POST:
1725     case ARM::STC2L_POST:
1726     case ARM::t2LDC_POST:
1727     case ARM::t2LDCL_POST:
1728     case ARM::t2STC_POST:
1729     case ARM::t2STCL_POST:
1730     case ARM::LDC_POST:
1731     case ARM::LDCL_POST:
1732     case ARM::STC_POST:
1733     case ARM::STCL_POST:
1734       imm |= U << 8;
1735       LLVM_FALLTHROUGH;
1736     default:
1737       // The 'option' variant doesn't encode 'U' in the immediate since
1738       // the immediate is unsigned [0,255].
1739       Inst.addOperand(MCOperand::createImm(imm));
1740       break;
1741   }
1742 
1743   switch (Inst.getOpcode()) {
1744     case ARM::LDC_OFFSET:
1745     case ARM::LDC_PRE:
1746     case ARM::LDC_POST:
1747     case ARM::LDC_OPTION:
1748     case ARM::LDCL_OFFSET:
1749     case ARM::LDCL_PRE:
1750     case ARM::LDCL_POST:
1751     case ARM::LDCL_OPTION:
1752     case ARM::STC_OFFSET:
1753     case ARM::STC_PRE:
1754     case ARM::STC_POST:
1755     case ARM::STC_OPTION:
1756     case ARM::STCL_OFFSET:
1757     case ARM::STCL_PRE:
1758     case ARM::STCL_POST:
1759     case ARM::STCL_OPTION:
1760       if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1761         return MCDisassembler::Fail;
1762       break;
1763     default:
1764       break;
1765   }
1766 
1767   return S;
1768 }
1769 
1770 static DecodeStatus
1771 DecodeAddrMode2IdxInstruction(MCInst &Inst, unsigned Insn,
1772                               uint64_t Address, const void *Decoder) {
1773   DecodeStatus S = MCDisassembler::Success;
1774 
1775   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1776   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
1777   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
1778   unsigned imm = fieldFromInstruction(Insn, 0, 12);
1779   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1780   unsigned reg = fieldFromInstruction(Insn, 25, 1);
1781   unsigned P = fieldFromInstruction(Insn, 24, 1);
1782   unsigned W = fieldFromInstruction(Insn, 21, 1);
1783 
1784   // On stores, the writeback operand precedes Rt.
1785   switch (Inst.getOpcode()) {
1786     case ARM::STR_POST_IMM:
1787     case ARM::STR_POST_REG:
1788     case ARM::STRB_POST_IMM:
1789     case ARM::STRB_POST_REG:
1790     case ARM::STRT_POST_REG:
1791     case ARM::STRT_POST_IMM:
1792     case ARM::STRBT_POST_REG:
1793     case ARM::STRBT_POST_IMM:
1794       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1795         return MCDisassembler::Fail;
1796       break;
1797     default:
1798       break;
1799   }
1800 
1801   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
1802     return MCDisassembler::Fail;
1803 
1804   // On loads, the writeback operand comes after Rt.
1805   switch (Inst.getOpcode()) {
1806     case ARM::LDR_POST_IMM:
1807     case ARM::LDR_POST_REG:
1808     case ARM::LDRB_POST_IMM:
1809     case ARM::LDRB_POST_REG:
1810     case ARM::LDRBT_POST_REG:
1811     case ARM::LDRBT_POST_IMM:
1812     case ARM::LDRT_POST_REG:
1813     case ARM::LDRT_POST_IMM:
1814       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1815         return MCDisassembler::Fail;
1816       break;
1817     default:
1818       break;
1819   }
1820 
1821   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1822     return MCDisassembler::Fail;
1823 
1824   ARM_AM::AddrOpc Op = ARM_AM::add;
1825   if (!fieldFromInstruction(Insn, 23, 1))
1826     Op = ARM_AM::sub;
1827 
1828   bool writeback = (P == 0) || (W == 1);
1829   unsigned idx_mode = 0;
1830   if (P && writeback)
1831     idx_mode = ARMII::IndexModePre;
1832   else if (!P && writeback)
1833     idx_mode = ARMII::IndexModePost;
1834 
1835   if (writeback && (Rn == 15 || Rn == Rt))
1836     S = MCDisassembler::SoftFail; // UNPREDICTABLE
1837 
1838   if (reg) {
1839     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1840       return MCDisassembler::Fail;
1841     ARM_AM::ShiftOpc Opc = ARM_AM::lsl;
1842     switch( fieldFromInstruction(Insn, 5, 2)) {
1843       case 0:
1844         Opc = ARM_AM::lsl;
1845         break;
1846       case 1:
1847         Opc = ARM_AM::lsr;
1848         break;
1849       case 2:
1850         Opc = ARM_AM::asr;
1851         break;
1852       case 3:
1853         Opc = ARM_AM::ror;
1854         break;
1855       default:
1856         return MCDisassembler::Fail;
1857     }
1858     unsigned amt = fieldFromInstruction(Insn, 7, 5);
1859     if (Opc == ARM_AM::ror && amt == 0)
1860       Opc = ARM_AM::rrx;
1861     unsigned imm = ARM_AM::getAM2Opc(Op, amt, Opc, idx_mode);
1862 
1863     Inst.addOperand(MCOperand::createImm(imm));
1864   } else {
1865     Inst.addOperand(MCOperand::createReg(0));
1866     unsigned tmp = ARM_AM::getAM2Opc(Op, imm, ARM_AM::lsl, idx_mode);
1867     Inst.addOperand(MCOperand::createImm(tmp));
1868   }
1869 
1870   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1871     return MCDisassembler::Fail;
1872 
1873   return S;
1874 }
1875 
1876 static DecodeStatus DecodeSORegMemOperand(MCInst &Inst, unsigned Val,
1877                                   uint64_t Address, const void *Decoder) {
1878   DecodeStatus S = MCDisassembler::Success;
1879 
1880   unsigned Rn = fieldFromInstruction(Val, 13, 4);
1881   unsigned Rm = fieldFromInstruction(Val,  0, 4);
1882   unsigned type = fieldFromInstruction(Val, 5, 2);
1883   unsigned imm = fieldFromInstruction(Val, 7, 5);
1884   unsigned U = fieldFromInstruction(Val, 12, 1);
1885 
1886   ARM_AM::ShiftOpc ShOp = ARM_AM::lsl;
1887   switch (type) {
1888     case 0:
1889       ShOp = ARM_AM::lsl;
1890       break;
1891     case 1:
1892       ShOp = ARM_AM::lsr;
1893       break;
1894     case 2:
1895       ShOp = ARM_AM::asr;
1896       break;
1897     case 3:
1898       ShOp = ARM_AM::ror;
1899       break;
1900   }
1901 
1902   if (ShOp == ARM_AM::ror && imm == 0)
1903     ShOp = ARM_AM::rrx;
1904 
1905   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1906     return MCDisassembler::Fail;
1907   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1908     return MCDisassembler::Fail;
1909   unsigned shift;
1910   if (U)
1911     shift = ARM_AM::getAM2Opc(ARM_AM::add, imm, ShOp);
1912   else
1913     shift = ARM_AM::getAM2Opc(ARM_AM::sub, imm, ShOp);
1914   Inst.addOperand(MCOperand::createImm(shift));
1915 
1916   return S;
1917 }
1918 
1919 static DecodeStatus
1920 DecodeAddrMode3Instruction(MCInst &Inst, unsigned Insn,
1921                            uint64_t Address, const void *Decoder) {
1922   DecodeStatus S = MCDisassembler::Success;
1923 
1924   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
1925   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1926   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
1927   unsigned type = fieldFromInstruction(Insn, 22, 1);
1928   unsigned imm = fieldFromInstruction(Insn, 8, 4);
1929   unsigned U = ((~fieldFromInstruction(Insn, 23, 1)) & 1) << 8;
1930   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1931   unsigned W = fieldFromInstruction(Insn, 21, 1);
1932   unsigned P = fieldFromInstruction(Insn, 24, 1);
1933   unsigned Rt2 = Rt + 1;
1934 
1935   bool writeback = (W == 1) | (P == 0);
1936 
1937   // For {LD,ST}RD, Rt must be even, else undefined.
1938   switch (Inst.getOpcode()) {
1939     case ARM::STRD:
1940     case ARM::STRD_PRE:
1941     case ARM::STRD_POST:
1942     case ARM::LDRD:
1943     case ARM::LDRD_PRE:
1944     case ARM::LDRD_POST:
1945       if (Rt & 0x1) S = MCDisassembler::SoftFail;
1946       break;
1947     default:
1948       break;
1949   }
1950   switch (Inst.getOpcode()) {
1951     case ARM::STRD:
1952     case ARM::STRD_PRE:
1953     case ARM::STRD_POST:
1954       if (P == 0 && W == 1)
1955         S = MCDisassembler::SoftFail;
1956 
1957       if (writeback && (Rn == 15 || Rn == Rt || Rn == Rt2))
1958         S = MCDisassembler::SoftFail;
1959       if (type && Rm == 15)
1960         S = MCDisassembler::SoftFail;
1961       if (Rt2 == 15)
1962         S = MCDisassembler::SoftFail;
1963       if (!type && fieldFromInstruction(Insn, 8, 4))
1964         S = MCDisassembler::SoftFail;
1965       break;
1966     case ARM::STRH:
1967     case ARM::STRH_PRE:
1968     case ARM::STRH_POST:
1969       if (Rt == 15)
1970         S = MCDisassembler::SoftFail;
1971       if (writeback && (Rn == 15 || Rn == Rt))
1972         S = MCDisassembler::SoftFail;
1973       if (!type && Rm == 15)
1974         S = MCDisassembler::SoftFail;
1975       break;
1976     case ARM::LDRD:
1977     case ARM::LDRD_PRE:
1978     case ARM::LDRD_POST:
1979       if (type && Rn == 15) {
1980         if (Rt2 == 15)
1981           S = MCDisassembler::SoftFail;
1982         break;
1983       }
1984       if (P == 0 && W == 1)
1985         S = MCDisassembler::SoftFail;
1986       if (!type && (Rt2 == 15 || Rm == 15 || Rm == Rt || Rm == Rt2))
1987         S = MCDisassembler::SoftFail;
1988       if (!type && writeback && Rn == 15)
1989         S = MCDisassembler::SoftFail;
1990       if (writeback && (Rn == Rt || Rn == Rt2))
1991         S = MCDisassembler::SoftFail;
1992       break;
1993     case ARM::LDRH:
1994     case ARM::LDRH_PRE:
1995     case ARM::LDRH_POST:
1996       if (type && Rn == 15) {
1997         if (Rt == 15)
1998           S = MCDisassembler::SoftFail;
1999         break;
2000       }
2001       if (Rt == 15)
2002         S = MCDisassembler::SoftFail;
2003       if (!type && Rm == 15)
2004         S = MCDisassembler::SoftFail;
2005       if (!type && writeback && (Rn == 15 || Rn == Rt))
2006         S = MCDisassembler::SoftFail;
2007       break;
2008     case ARM::LDRSH:
2009     case ARM::LDRSH_PRE:
2010     case ARM::LDRSH_POST:
2011     case ARM::LDRSB:
2012     case ARM::LDRSB_PRE:
2013     case ARM::LDRSB_POST:
2014       if (type && Rn == 15) {
2015         if (Rt == 15)
2016           S = MCDisassembler::SoftFail;
2017         break;
2018       }
2019       if (type && (Rt == 15 || (writeback && Rn == Rt)))
2020         S = MCDisassembler::SoftFail;
2021       if (!type && (Rt == 15 || Rm == 15))
2022         S = MCDisassembler::SoftFail;
2023       if (!type && writeback && (Rn == 15 || Rn == Rt))
2024         S = MCDisassembler::SoftFail;
2025       break;
2026     default:
2027       break;
2028   }
2029 
2030   if (writeback) { // Writeback
2031     if (P)
2032       U |= ARMII::IndexModePre << 9;
2033     else
2034       U |= ARMII::IndexModePost << 9;
2035 
2036     // On stores, the writeback operand precedes Rt.
2037     switch (Inst.getOpcode()) {
2038     case ARM::STRD:
2039     case ARM::STRD_PRE:
2040     case ARM::STRD_POST:
2041     case ARM::STRH:
2042     case ARM::STRH_PRE:
2043     case ARM::STRH_POST:
2044       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2045         return MCDisassembler::Fail;
2046       break;
2047     default:
2048       break;
2049     }
2050   }
2051 
2052   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
2053     return MCDisassembler::Fail;
2054   switch (Inst.getOpcode()) {
2055     case ARM::STRD:
2056     case ARM::STRD_PRE:
2057     case ARM::STRD_POST:
2058     case ARM::LDRD:
2059     case ARM::LDRD_PRE:
2060     case ARM::LDRD_POST:
2061       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder)))
2062         return MCDisassembler::Fail;
2063       break;
2064     default:
2065       break;
2066   }
2067 
2068   if (writeback) {
2069     // On loads, the writeback operand comes after Rt.
2070     switch (Inst.getOpcode()) {
2071     case ARM::LDRD:
2072     case ARM::LDRD_PRE:
2073     case ARM::LDRD_POST:
2074     case ARM::LDRH:
2075     case ARM::LDRH_PRE:
2076     case ARM::LDRH_POST:
2077     case ARM::LDRSH:
2078     case ARM::LDRSH_PRE:
2079     case ARM::LDRSH_POST:
2080     case ARM::LDRSB:
2081     case ARM::LDRSB_PRE:
2082     case ARM::LDRSB_POST:
2083     case ARM::LDRHTr:
2084     case ARM::LDRSBTr:
2085       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2086         return MCDisassembler::Fail;
2087       break;
2088     default:
2089       break;
2090     }
2091   }
2092 
2093   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2094     return MCDisassembler::Fail;
2095 
2096   if (type) {
2097     Inst.addOperand(MCOperand::createReg(0));
2098     Inst.addOperand(MCOperand::createImm(U | (imm << 4) | Rm));
2099   } else {
2100     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2101     return MCDisassembler::Fail;
2102     Inst.addOperand(MCOperand::createImm(U));
2103   }
2104 
2105   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2106     return MCDisassembler::Fail;
2107 
2108   return S;
2109 }
2110 
2111 static DecodeStatus DecodeRFEInstruction(MCInst &Inst, unsigned Insn,
2112                                  uint64_t Address, const void *Decoder) {
2113   DecodeStatus S = MCDisassembler::Success;
2114 
2115   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2116   unsigned mode = fieldFromInstruction(Insn, 23, 2);
2117 
2118   switch (mode) {
2119     case 0:
2120       mode = ARM_AM::da;
2121       break;
2122     case 1:
2123       mode = ARM_AM::ia;
2124       break;
2125     case 2:
2126       mode = ARM_AM::db;
2127       break;
2128     case 3:
2129       mode = ARM_AM::ib;
2130       break;
2131   }
2132 
2133   Inst.addOperand(MCOperand::createImm(mode));
2134   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2135     return MCDisassembler::Fail;
2136 
2137   return S;
2138 }
2139 
2140 static DecodeStatus DecodeQADDInstruction(MCInst &Inst, unsigned Insn,
2141                                uint64_t Address, const void *Decoder) {
2142   DecodeStatus S = MCDisassembler::Success;
2143 
2144   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2145   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2146   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2147   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2148 
2149   if (pred == 0xF)
2150     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
2151 
2152   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2153     return MCDisassembler::Fail;
2154   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
2155     return MCDisassembler::Fail;
2156   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
2157     return MCDisassembler::Fail;
2158   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2159     return MCDisassembler::Fail;
2160   return S;
2161 }
2162 
2163 static DecodeStatus DecodeMemMultipleWritebackInstruction(MCInst &Inst,
2164                                   unsigned Insn,
2165                                   uint64_t Address, const void *Decoder) {
2166   DecodeStatus S = MCDisassembler::Success;
2167 
2168   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2169   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2170   unsigned reglist = fieldFromInstruction(Insn, 0, 16);
2171 
2172   if (pred == 0xF) {
2173     // Ambiguous with RFE and SRS
2174     switch (Inst.getOpcode()) {
2175       case ARM::LDMDA:
2176         Inst.setOpcode(ARM::RFEDA);
2177         break;
2178       case ARM::LDMDA_UPD:
2179         Inst.setOpcode(ARM::RFEDA_UPD);
2180         break;
2181       case ARM::LDMDB:
2182         Inst.setOpcode(ARM::RFEDB);
2183         break;
2184       case ARM::LDMDB_UPD:
2185         Inst.setOpcode(ARM::RFEDB_UPD);
2186         break;
2187       case ARM::LDMIA:
2188         Inst.setOpcode(ARM::RFEIA);
2189         break;
2190       case ARM::LDMIA_UPD:
2191         Inst.setOpcode(ARM::RFEIA_UPD);
2192         break;
2193       case ARM::LDMIB:
2194         Inst.setOpcode(ARM::RFEIB);
2195         break;
2196       case ARM::LDMIB_UPD:
2197         Inst.setOpcode(ARM::RFEIB_UPD);
2198         break;
2199       case ARM::STMDA:
2200         Inst.setOpcode(ARM::SRSDA);
2201         break;
2202       case ARM::STMDA_UPD:
2203         Inst.setOpcode(ARM::SRSDA_UPD);
2204         break;
2205       case ARM::STMDB:
2206         Inst.setOpcode(ARM::SRSDB);
2207         break;
2208       case ARM::STMDB_UPD:
2209         Inst.setOpcode(ARM::SRSDB_UPD);
2210         break;
2211       case ARM::STMIA:
2212         Inst.setOpcode(ARM::SRSIA);
2213         break;
2214       case ARM::STMIA_UPD:
2215         Inst.setOpcode(ARM::SRSIA_UPD);
2216         break;
2217       case ARM::STMIB:
2218         Inst.setOpcode(ARM::SRSIB);
2219         break;
2220       case ARM::STMIB_UPD:
2221         Inst.setOpcode(ARM::SRSIB_UPD);
2222         break;
2223       default:
2224         return MCDisassembler::Fail;
2225     }
2226 
2227     // For stores (which become SRS's, the only operand is the mode.
2228     if (fieldFromInstruction(Insn, 20, 1) == 0) {
2229       // Check SRS encoding constraints
2230       if (!(fieldFromInstruction(Insn, 22, 1) == 1 &&
2231             fieldFromInstruction(Insn, 20, 1) == 0))
2232         return MCDisassembler::Fail;
2233 
2234       Inst.addOperand(
2235           MCOperand::createImm(fieldFromInstruction(Insn, 0, 4)));
2236       return S;
2237     }
2238 
2239     return DecodeRFEInstruction(Inst, Insn, Address, Decoder);
2240   }
2241 
2242   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2243     return MCDisassembler::Fail;
2244   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2245     return MCDisassembler::Fail; // Tied
2246   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2247     return MCDisassembler::Fail;
2248   if (!Check(S, DecodeRegListOperand(Inst, reglist, Address, Decoder)))
2249     return MCDisassembler::Fail;
2250 
2251   return S;
2252 }
2253 
2254 // Check for UNPREDICTABLE predicated ESB instruction
2255 static DecodeStatus DecodeHINTInstruction(MCInst &Inst, unsigned Insn,
2256                                  uint64_t Address, const void *Decoder) {
2257   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2258   unsigned imm8 = fieldFromInstruction(Insn, 0, 8);
2259   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
2260   const FeatureBitset &FeatureBits = Dis->getSubtargetInfo().getFeatureBits();
2261 
2262   DecodeStatus S = MCDisassembler::Success;
2263 
2264   Inst.addOperand(MCOperand::createImm(imm8));
2265 
2266   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2267     return MCDisassembler::Fail;
2268 
2269   // ESB is unpredictable if pred != AL. Without the RAS extension, it is a NOP,
2270   // so all predicates should be allowed.
2271   if (imm8 == 0x10 && pred != 0xe && ((FeatureBits[ARM::FeatureRAS]) != 0))
2272     S = MCDisassembler::SoftFail;
2273 
2274   return S;
2275 }
2276 
2277 static DecodeStatus DecodeCPSInstruction(MCInst &Inst, unsigned Insn,
2278                                  uint64_t Address, const void *Decoder) {
2279   unsigned imod = fieldFromInstruction(Insn, 18, 2);
2280   unsigned M = fieldFromInstruction(Insn, 17, 1);
2281   unsigned iflags = fieldFromInstruction(Insn, 6, 3);
2282   unsigned mode = fieldFromInstruction(Insn, 0, 5);
2283 
2284   DecodeStatus S = MCDisassembler::Success;
2285 
2286   // This decoder is called from multiple location that do not check
2287   // the full encoding is valid before they do.
2288   if (fieldFromInstruction(Insn, 5, 1) != 0 ||
2289       fieldFromInstruction(Insn, 16, 1) != 0 ||
2290       fieldFromInstruction(Insn, 20, 8) != 0x10)
2291     return MCDisassembler::Fail;
2292 
2293   // imod == '01' --> UNPREDICTABLE
2294   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
2295   // return failure here.  The '01' imod value is unprintable, so there's
2296   // nothing useful we could do even if we returned UNPREDICTABLE.
2297 
2298   if (imod == 1) return MCDisassembler::Fail;
2299 
2300   if (imod && M) {
2301     Inst.setOpcode(ARM::CPS3p);
2302     Inst.addOperand(MCOperand::createImm(imod));
2303     Inst.addOperand(MCOperand::createImm(iflags));
2304     Inst.addOperand(MCOperand::createImm(mode));
2305   } else if (imod && !M) {
2306     Inst.setOpcode(ARM::CPS2p);
2307     Inst.addOperand(MCOperand::createImm(imod));
2308     Inst.addOperand(MCOperand::createImm(iflags));
2309     if (mode) S = MCDisassembler::SoftFail;
2310   } else if (!imod && M) {
2311     Inst.setOpcode(ARM::CPS1p);
2312     Inst.addOperand(MCOperand::createImm(mode));
2313     if (iflags) S = MCDisassembler::SoftFail;
2314   } else {
2315     // imod == '00' && M == '0' --> UNPREDICTABLE
2316     Inst.setOpcode(ARM::CPS1p);
2317     Inst.addOperand(MCOperand::createImm(mode));
2318     S = MCDisassembler::SoftFail;
2319   }
2320 
2321   return S;
2322 }
2323 
2324 static DecodeStatus DecodeT2CPSInstruction(MCInst &Inst, unsigned Insn,
2325                                  uint64_t Address, const void *Decoder) {
2326   unsigned imod = fieldFromInstruction(Insn, 9, 2);
2327   unsigned M = fieldFromInstruction(Insn, 8, 1);
2328   unsigned iflags = fieldFromInstruction(Insn, 5, 3);
2329   unsigned mode = fieldFromInstruction(Insn, 0, 5);
2330 
2331   DecodeStatus S = MCDisassembler::Success;
2332 
2333   // imod == '01' --> UNPREDICTABLE
2334   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
2335   // return failure here.  The '01' imod value is unprintable, so there's
2336   // nothing useful we could do even if we returned UNPREDICTABLE.
2337 
2338   if (imod == 1) return MCDisassembler::Fail;
2339 
2340   if (imod && M) {
2341     Inst.setOpcode(ARM::t2CPS3p);
2342     Inst.addOperand(MCOperand::createImm(imod));
2343     Inst.addOperand(MCOperand::createImm(iflags));
2344     Inst.addOperand(MCOperand::createImm(mode));
2345   } else if (imod && !M) {
2346     Inst.setOpcode(ARM::t2CPS2p);
2347     Inst.addOperand(MCOperand::createImm(imod));
2348     Inst.addOperand(MCOperand::createImm(iflags));
2349     if (mode) S = MCDisassembler::SoftFail;
2350   } else if (!imod && M) {
2351     Inst.setOpcode(ARM::t2CPS1p);
2352     Inst.addOperand(MCOperand::createImm(mode));
2353     if (iflags) S = MCDisassembler::SoftFail;
2354   } else {
2355     // imod == '00' && M == '0' --> this is a HINT instruction
2356     int imm = fieldFromInstruction(Insn, 0, 8);
2357     // HINT are defined only for immediate in [0..4]
2358     if(imm > 4) return MCDisassembler::Fail;
2359     Inst.setOpcode(ARM::t2HINT);
2360     Inst.addOperand(MCOperand::createImm(imm));
2361   }
2362 
2363   return S;
2364 }
2365 
2366 static DecodeStatus DecodeT2MOVTWInstruction(MCInst &Inst, unsigned Insn,
2367                                  uint64_t Address, const void *Decoder) {
2368   DecodeStatus S = MCDisassembler::Success;
2369 
2370   unsigned Rd = fieldFromInstruction(Insn, 8, 4);
2371   unsigned imm = 0;
2372 
2373   imm |= (fieldFromInstruction(Insn, 0, 8) << 0);
2374   imm |= (fieldFromInstruction(Insn, 12, 3) << 8);
2375   imm |= (fieldFromInstruction(Insn, 16, 4) << 12);
2376   imm |= (fieldFromInstruction(Insn, 26, 1) << 11);
2377 
2378   if (Inst.getOpcode() == ARM::t2MOVTi16)
2379     if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
2380       return MCDisassembler::Fail;
2381   if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
2382     return MCDisassembler::Fail;
2383 
2384   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
2385     Inst.addOperand(MCOperand::createImm(imm));
2386 
2387   return S;
2388 }
2389 
2390 static DecodeStatus DecodeArmMOVTWInstruction(MCInst &Inst, unsigned Insn,
2391                                  uint64_t Address, const void *Decoder) {
2392   DecodeStatus S = MCDisassembler::Success;
2393 
2394   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2395   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2396   unsigned imm = 0;
2397 
2398   imm |= (fieldFromInstruction(Insn, 0, 12) << 0);
2399   imm |= (fieldFromInstruction(Insn, 16, 4) << 12);
2400 
2401   if (Inst.getOpcode() == ARM::MOVTi16)
2402     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2403       return MCDisassembler::Fail;
2404 
2405   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2406     return MCDisassembler::Fail;
2407 
2408   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
2409     Inst.addOperand(MCOperand::createImm(imm));
2410 
2411   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2412     return MCDisassembler::Fail;
2413 
2414   return S;
2415 }
2416 
2417 static DecodeStatus DecodeSMLAInstruction(MCInst &Inst, unsigned Insn,
2418                                  uint64_t Address, const void *Decoder) {
2419   DecodeStatus S = MCDisassembler::Success;
2420 
2421   unsigned Rd = fieldFromInstruction(Insn, 16, 4);
2422   unsigned Rn = fieldFromInstruction(Insn, 0, 4);
2423   unsigned Rm = fieldFromInstruction(Insn, 8, 4);
2424   unsigned Ra = fieldFromInstruction(Insn, 12, 4);
2425   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2426 
2427   if (pred == 0xF)
2428     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
2429 
2430   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2431     return MCDisassembler::Fail;
2432   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
2433     return MCDisassembler::Fail;
2434   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
2435     return MCDisassembler::Fail;
2436   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Ra, Address, Decoder)))
2437     return MCDisassembler::Fail;
2438 
2439   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2440     return MCDisassembler::Fail;
2441 
2442   return S;
2443 }
2444 
2445 static DecodeStatus DecodeTSTInstruction(MCInst &Inst, unsigned Insn,
2446                                   uint64_t Address, const void *Decoder) {
2447   DecodeStatus S = MCDisassembler::Success;
2448 
2449   unsigned Pred = fieldFromInstruction(Insn, 28, 4);
2450   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2451   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2452 
2453   if (Pred == 0xF)
2454     return DecodeSETPANInstruction(Inst, Insn, Address, Decoder);
2455 
2456   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2457     return MCDisassembler::Fail;
2458   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2459     return MCDisassembler::Fail;
2460   if (!Check(S, DecodePredicateOperand(Inst, Pred, Address, Decoder)))
2461     return MCDisassembler::Fail;
2462 
2463   return S;
2464 }
2465 
2466 static DecodeStatus DecodeSETPANInstruction(MCInst &Inst, unsigned Insn,
2467                                   uint64_t Address, const void *Decoder) {
2468   DecodeStatus S = MCDisassembler::Success;
2469 
2470   unsigned Imm = fieldFromInstruction(Insn, 9, 1);
2471 
2472   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
2473   const FeatureBitset &FeatureBits = Dis->getSubtargetInfo().getFeatureBits();
2474 
2475   if (!FeatureBits[ARM::HasV8_1aOps] ||
2476       !FeatureBits[ARM::HasV8Ops])
2477     return MCDisassembler::Fail;
2478 
2479   // Decoder can be called from DecodeTST, which does not check the full
2480   // encoding is valid.
2481   if (fieldFromInstruction(Insn, 20,12) != 0xf11 ||
2482       fieldFromInstruction(Insn, 4,4) != 0)
2483     return MCDisassembler::Fail;
2484   if (fieldFromInstruction(Insn, 10,10) != 0 ||
2485       fieldFromInstruction(Insn, 0,4) != 0)
2486     S = MCDisassembler::SoftFail;
2487 
2488   Inst.setOpcode(ARM::SETPAN);
2489   Inst.addOperand(MCOperand::createImm(Imm));
2490 
2491   return S;
2492 }
2493 
2494 static DecodeStatus DecodeAddrModeImm12Operand(MCInst &Inst, unsigned Val,
2495                            uint64_t Address, const void *Decoder) {
2496   DecodeStatus S = MCDisassembler::Success;
2497 
2498   unsigned add = fieldFromInstruction(Val, 12, 1);
2499   unsigned imm = fieldFromInstruction(Val, 0, 12);
2500   unsigned Rn = fieldFromInstruction(Val, 13, 4);
2501 
2502   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2503     return MCDisassembler::Fail;
2504 
2505   if (!add) imm *= -1;
2506   if (imm == 0 && !add) imm = INT32_MIN;
2507   Inst.addOperand(MCOperand::createImm(imm));
2508   if (Rn == 15)
2509     tryAddingPcLoadReferenceComment(Address, Address + imm + 8, Decoder);
2510 
2511   return S;
2512 }
2513 
2514 static DecodeStatus DecodeAddrMode5Operand(MCInst &Inst, unsigned Val,
2515                                    uint64_t Address, const void *Decoder) {
2516   DecodeStatus S = MCDisassembler::Success;
2517 
2518   unsigned Rn = fieldFromInstruction(Val, 9, 4);
2519   // U == 1 to add imm, 0 to subtract it.
2520   unsigned U = fieldFromInstruction(Val, 8, 1);
2521   unsigned imm = fieldFromInstruction(Val, 0, 8);
2522 
2523   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2524     return MCDisassembler::Fail;
2525 
2526   if (U)
2527     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5Opc(ARM_AM::add, imm)));
2528   else
2529     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5Opc(ARM_AM::sub, imm)));
2530 
2531   return S;
2532 }
2533 
2534 static DecodeStatus DecodeAddrMode5FP16Operand(MCInst &Inst, unsigned Val,
2535                                    uint64_t Address, const void *Decoder) {
2536   DecodeStatus S = MCDisassembler::Success;
2537 
2538   unsigned Rn = fieldFromInstruction(Val, 9, 4);
2539   // U == 1 to add imm, 0 to subtract it.
2540   unsigned U = fieldFromInstruction(Val, 8, 1);
2541   unsigned imm = fieldFromInstruction(Val, 0, 8);
2542 
2543   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2544     return MCDisassembler::Fail;
2545 
2546   if (U)
2547     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5FP16Opc(ARM_AM::add, imm)));
2548   else
2549     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5FP16Opc(ARM_AM::sub, imm)));
2550 
2551   return S;
2552 }
2553 
2554 static DecodeStatus DecodeAddrMode7Operand(MCInst &Inst, unsigned Val,
2555                                    uint64_t Address, const void *Decoder) {
2556   return DecodeGPRRegisterClass(Inst, Val, Address, Decoder);
2557 }
2558 
2559 static DecodeStatus
2560 DecodeT2BInstruction(MCInst &Inst, unsigned Insn,
2561                      uint64_t Address, const void *Decoder) {
2562   DecodeStatus Status = MCDisassembler::Success;
2563 
2564   // Note the J1 and J2 values are from the encoded instruction.  So here
2565   // change them to I1 and I2 values via as documented:
2566   // I1 = NOT(J1 EOR S);
2567   // I2 = NOT(J2 EOR S);
2568   // and build the imm32 with one trailing zero as documented:
2569   // imm32 = SignExtend(S:I1:I2:imm10:imm11:'0', 32);
2570   unsigned S = fieldFromInstruction(Insn, 26, 1);
2571   unsigned J1 = fieldFromInstruction(Insn, 13, 1);
2572   unsigned J2 = fieldFromInstruction(Insn, 11, 1);
2573   unsigned I1 = !(J1 ^ S);
2574   unsigned I2 = !(J2 ^ S);
2575   unsigned imm10 = fieldFromInstruction(Insn, 16, 10);
2576   unsigned imm11 = fieldFromInstruction(Insn, 0, 11);
2577   unsigned tmp = (S << 23) | (I1 << 22) | (I2 << 21) | (imm10 << 11) | imm11;
2578   int imm32 = SignExtend32<25>(tmp << 1);
2579   if (!tryAddingSymbolicOperand(Address, Address + imm32 + 4,
2580                                 true, 4, Inst, Decoder))
2581     Inst.addOperand(MCOperand::createImm(imm32));
2582 
2583   return Status;
2584 }
2585 
2586 static DecodeStatus
2587 DecodeBranchImmInstruction(MCInst &Inst, unsigned Insn,
2588                            uint64_t Address, const void *Decoder) {
2589   DecodeStatus S = MCDisassembler::Success;
2590 
2591   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2592   unsigned imm = fieldFromInstruction(Insn, 0, 24) << 2;
2593 
2594   if (pred == 0xF) {
2595     Inst.setOpcode(ARM::BLXi);
2596     imm |= fieldFromInstruction(Insn, 24, 1) << 1;
2597     if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<26>(imm) + 8,
2598                                   true, 4, Inst, Decoder))
2599     Inst.addOperand(MCOperand::createImm(SignExtend32<26>(imm)));
2600     return S;
2601   }
2602 
2603   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<26>(imm) + 8,
2604                                 true, 4, Inst, Decoder))
2605     Inst.addOperand(MCOperand::createImm(SignExtend32<26>(imm)));
2606   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2607     return MCDisassembler::Fail;
2608 
2609   return S;
2610 }
2611 
2612 static DecodeStatus DecodeAddrMode6Operand(MCInst &Inst, unsigned Val,
2613                                    uint64_t Address, const void *Decoder) {
2614   DecodeStatus S = MCDisassembler::Success;
2615 
2616   unsigned Rm = fieldFromInstruction(Val, 0, 4);
2617   unsigned align = fieldFromInstruction(Val, 4, 2);
2618 
2619   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2620     return MCDisassembler::Fail;
2621   if (!align)
2622     Inst.addOperand(MCOperand::createImm(0));
2623   else
2624     Inst.addOperand(MCOperand::createImm(4 << align));
2625 
2626   return S;
2627 }
2628 
2629 static DecodeStatus DecodeVLDInstruction(MCInst &Inst, unsigned Insn,
2630                                    uint64_t Address, const void *Decoder) {
2631   DecodeStatus S = MCDisassembler::Success;
2632 
2633   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2634   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
2635   unsigned wb = fieldFromInstruction(Insn, 16, 4);
2636   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2637   Rn |= fieldFromInstruction(Insn, 4, 2) << 4;
2638   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2639 
2640   // First output register
2641   switch (Inst.getOpcode()) {
2642   case ARM::VLD1q16: case ARM::VLD1q32: case ARM::VLD1q64: case ARM::VLD1q8:
2643   case ARM::VLD1q16wb_fixed: case ARM::VLD1q16wb_register:
2644   case ARM::VLD1q32wb_fixed: case ARM::VLD1q32wb_register:
2645   case ARM::VLD1q64wb_fixed: case ARM::VLD1q64wb_register:
2646   case ARM::VLD1q8wb_fixed: case ARM::VLD1q8wb_register:
2647   case ARM::VLD2d16: case ARM::VLD2d32: case ARM::VLD2d8:
2648   case ARM::VLD2d16wb_fixed: case ARM::VLD2d16wb_register:
2649   case ARM::VLD2d32wb_fixed: case ARM::VLD2d32wb_register:
2650   case ARM::VLD2d8wb_fixed: case ARM::VLD2d8wb_register:
2651     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
2652       return MCDisassembler::Fail;
2653     break;
2654   case ARM::VLD2b16:
2655   case ARM::VLD2b32:
2656   case ARM::VLD2b8:
2657   case ARM::VLD2b16wb_fixed:
2658   case ARM::VLD2b16wb_register:
2659   case ARM::VLD2b32wb_fixed:
2660   case ARM::VLD2b32wb_register:
2661   case ARM::VLD2b8wb_fixed:
2662   case ARM::VLD2b8wb_register:
2663     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
2664       return MCDisassembler::Fail;
2665     break;
2666   default:
2667     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2668       return MCDisassembler::Fail;
2669   }
2670 
2671   // Second output register
2672   switch (Inst.getOpcode()) {
2673     case ARM::VLD3d8:
2674     case ARM::VLD3d16:
2675     case ARM::VLD3d32:
2676     case ARM::VLD3d8_UPD:
2677     case ARM::VLD3d16_UPD:
2678     case ARM::VLD3d32_UPD:
2679     case ARM::VLD4d8:
2680     case ARM::VLD4d16:
2681     case ARM::VLD4d32:
2682     case ARM::VLD4d8_UPD:
2683     case ARM::VLD4d16_UPD:
2684     case ARM::VLD4d32_UPD:
2685       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
2686         return MCDisassembler::Fail;
2687       break;
2688     case ARM::VLD3q8:
2689     case ARM::VLD3q16:
2690     case ARM::VLD3q32:
2691     case ARM::VLD3q8_UPD:
2692     case ARM::VLD3q16_UPD:
2693     case ARM::VLD3q32_UPD:
2694     case ARM::VLD4q8:
2695     case ARM::VLD4q16:
2696     case ARM::VLD4q32:
2697     case ARM::VLD4q8_UPD:
2698     case ARM::VLD4q16_UPD:
2699     case ARM::VLD4q32_UPD:
2700       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2701         return MCDisassembler::Fail;
2702       break;
2703     default:
2704       break;
2705   }
2706 
2707   // Third output register
2708   switch(Inst.getOpcode()) {
2709     case ARM::VLD3d8:
2710     case ARM::VLD3d16:
2711     case ARM::VLD3d32:
2712     case ARM::VLD3d8_UPD:
2713     case ARM::VLD3d16_UPD:
2714     case ARM::VLD3d32_UPD:
2715     case ARM::VLD4d8:
2716     case ARM::VLD4d16:
2717     case ARM::VLD4d32:
2718     case ARM::VLD4d8_UPD:
2719     case ARM::VLD4d16_UPD:
2720     case ARM::VLD4d32_UPD:
2721       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2722         return MCDisassembler::Fail;
2723       break;
2724     case ARM::VLD3q8:
2725     case ARM::VLD3q16:
2726     case ARM::VLD3q32:
2727     case ARM::VLD3q8_UPD:
2728     case ARM::VLD3q16_UPD:
2729     case ARM::VLD3q32_UPD:
2730     case ARM::VLD4q8:
2731     case ARM::VLD4q16:
2732     case ARM::VLD4q32:
2733     case ARM::VLD4q8_UPD:
2734     case ARM::VLD4q16_UPD:
2735     case ARM::VLD4q32_UPD:
2736       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
2737         return MCDisassembler::Fail;
2738       break;
2739     default:
2740       break;
2741   }
2742 
2743   // Fourth output register
2744   switch (Inst.getOpcode()) {
2745     case ARM::VLD4d8:
2746     case ARM::VLD4d16:
2747     case ARM::VLD4d32:
2748     case ARM::VLD4d8_UPD:
2749     case ARM::VLD4d16_UPD:
2750     case ARM::VLD4d32_UPD:
2751       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
2752         return MCDisassembler::Fail;
2753       break;
2754     case ARM::VLD4q8:
2755     case ARM::VLD4q16:
2756     case ARM::VLD4q32:
2757     case ARM::VLD4q8_UPD:
2758     case ARM::VLD4q16_UPD:
2759     case ARM::VLD4q32_UPD:
2760       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
2761         return MCDisassembler::Fail;
2762       break;
2763     default:
2764       break;
2765   }
2766 
2767   // Writeback operand
2768   switch (Inst.getOpcode()) {
2769     case ARM::VLD1d8wb_fixed:
2770     case ARM::VLD1d16wb_fixed:
2771     case ARM::VLD1d32wb_fixed:
2772     case ARM::VLD1d64wb_fixed:
2773     case ARM::VLD1d8wb_register:
2774     case ARM::VLD1d16wb_register:
2775     case ARM::VLD1d32wb_register:
2776     case ARM::VLD1d64wb_register:
2777     case ARM::VLD1q8wb_fixed:
2778     case ARM::VLD1q16wb_fixed:
2779     case ARM::VLD1q32wb_fixed:
2780     case ARM::VLD1q64wb_fixed:
2781     case ARM::VLD1q8wb_register:
2782     case ARM::VLD1q16wb_register:
2783     case ARM::VLD1q32wb_register:
2784     case ARM::VLD1q64wb_register:
2785     case ARM::VLD1d8Twb_fixed:
2786     case ARM::VLD1d8Twb_register:
2787     case ARM::VLD1d16Twb_fixed:
2788     case ARM::VLD1d16Twb_register:
2789     case ARM::VLD1d32Twb_fixed:
2790     case ARM::VLD1d32Twb_register:
2791     case ARM::VLD1d64Twb_fixed:
2792     case ARM::VLD1d64Twb_register:
2793     case ARM::VLD1d8Qwb_fixed:
2794     case ARM::VLD1d8Qwb_register:
2795     case ARM::VLD1d16Qwb_fixed:
2796     case ARM::VLD1d16Qwb_register:
2797     case ARM::VLD1d32Qwb_fixed:
2798     case ARM::VLD1d32Qwb_register:
2799     case ARM::VLD1d64Qwb_fixed:
2800     case ARM::VLD1d64Qwb_register:
2801     case ARM::VLD2d8wb_fixed:
2802     case ARM::VLD2d16wb_fixed:
2803     case ARM::VLD2d32wb_fixed:
2804     case ARM::VLD2q8wb_fixed:
2805     case ARM::VLD2q16wb_fixed:
2806     case ARM::VLD2q32wb_fixed:
2807     case ARM::VLD2d8wb_register:
2808     case ARM::VLD2d16wb_register:
2809     case ARM::VLD2d32wb_register:
2810     case ARM::VLD2q8wb_register:
2811     case ARM::VLD2q16wb_register:
2812     case ARM::VLD2q32wb_register:
2813     case ARM::VLD2b8wb_fixed:
2814     case ARM::VLD2b16wb_fixed:
2815     case ARM::VLD2b32wb_fixed:
2816     case ARM::VLD2b8wb_register:
2817     case ARM::VLD2b16wb_register:
2818     case ARM::VLD2b32wb_register:
2819       Inst.addOperand(MCOperand::createImm(0));
2820       break;
2821     case ARM::VLD3d8_UPD:
2822     case ARM::VLD3d16_UPD:
2823     case ARM::VLD3d32_UPD:
2824     case ARM::VLD3q8_UPD:
2825     case ARM::VLD3q16_UPD:
2826     case ARM::VLD3q32_UPD:
2827     case ARM::VLD4d8_UPD:
2828     case ARM::VLD4d16_UPD:
2829     case ARM::VLD4d32_UPD:
2830     case ARM::VLD4q8_UPD:
2831     case ARM::VLD4q16_UPD:
2832     case ARM::VLD4q32_UPD:
2833       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
2834         return MCDisassembler::Fail;
2835       break;
2836     default:
2837       break;
2838   }
2839 
2840   // AddrMode6 Base (register+alignment)
2841   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
2842     return MCDisassembler::Fail;
2843 
2844   // AddrMode6 Offset (register)
2845   switch (Inst.getOpcode()) {
2846   default:
2847     // The below have been updated to have explicit am6offset split
2848     // between fixed and register offset. For those instructions not
2849     // yet updated, we need to add an additional reg0 operand for the
2850     // fixed variant.
2851     //
2852     // The fixed offset encodes as Rm == 0xd, so we check for that.
2853     if (Rm == 0xd) {
2854       Inst.addOperand(MCOperand::createReg(0));
2855       break;
2856     }
2857     // Fall through to handle the register offset variant.
2858     LLVM_FALLTHROUGH;
2859   case ARM::VLD1d8wb_fixed:
2860   case ARM::VLD1d16wb_fixed:
2861   case ARM::VLD1d32wb_fixed:
2862   case ARM::VLD1d64wb_fixed:
2863   case ARM::VLD1d8Twb_fixed:
2864   case ARM::VLD1d16Twb_fixed:
2865   case ARM::VLD1d32Twb_fixed:
2866   case ARM::VLD1d64Twb_fixed:
2867   case ARM::VLD1d8Qwb_fixed:
2868   case ARM::VLD1d16Qwb_fixed:
2869   case ARM::VLD1d32Qwb_fixed:
2870   case ARM::VLD1d64Qwb_fixed:
2871   case ARM::VLD1d8wb_register:
2872   case ARM::VLD1d16wb_register:
2873   case ARM::VLD1d32wb_register:
2874   case ARM::VLD1d64wb_register:
2875   case ARM::VLD1q8wb_fixed:
2876   case ARM::VLD1q16wb_fixed:
2877   case ARM::VLD1q32wb_fixed:
2878   case ARM::VLD1q64wb_fixed:
2879   case ARM::VLD1q8wb_register:
2880   case ARM::VLD1q16wb_register:
2881   case ARM::VLD1q32wb_register:
2882   case ARM::VLD1q64wb_register:
2883     // The fixed offset post-increment encodes Rm == 0xd. The no-writeback
2884     // variant encodes Rm == 0xf. Anything else is a register offset post-
2885     // increment and we need to add the register operand to the instruction.
2886     if (Rm != 0xD && Rm != 0xF &&
2887         !Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2888       return MCDisassembler::Fail;
2889     break;
2890   case ARM::VLD2d8wb_fixed:
2891   case ARM::VLD2d16wb_fixed:
2892   case ARM::VLD2d32wb_fixed:
2893   case ARM::VLD2b8wb_fixed:
2894   case ARM::VLD2b16wb_fixed:
2895   case ARM::VLD2b32wb_fixed:
2896   case ARM::VLD2q8wb_fixed:
2897   case ARM::VLD2q16wb_fixed:
2898   case ARM::VLD2q32wb_fixed:
2899     break;
2900   }
2901 
2902   return S;
2903 }
2904 
2905 static DecodeStatus DecodeVLDST1Instruction(MCInst &Inst, unsigned Insn,
2906                                    uint64_t Address, const void *Decoder) {
2907   unsigned type = fieldFromInstruction(Insn, 8, 4);
2908   unsigned align = fieldFromInstruction(Insn, 4, 2);
2909   if (type == 6 && (align & 2)) return MCDisassembler::Fail;
2910   if (type == 7 && (align & 2)) return MCDisassembler::Fail;
2911   if (type == 10 && align == 3) return MCDisassembler::Fail;
2912 
2913   unsigned load = fieldFromInstruction(Insn, 21, 1);
2914   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2915               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2916 }
2917 
2918 static DecodeStatus DecodeVLDST2Instruction(MCInst &Inst, unsigned Insn,
2919                                    uint64_t Address, const void *Decoder) {
2920   unsigned size = fieldFromInstruction(Insn, 6, 2);
2921   if (size == 3) return MCDisassembler::Fail;
2922 
2923   unsigned type = fieldFromInstruction(Insn, 8, 4);
2924   unsigned align = fieldFromInstruction(Insn, 4, 2);
2925   if (type == 8 && align == 3) return MCDisassembler::Fail;
2926   if (type == 9 && align == 3) return MCDisassembler::Fail;
2927 
2928   unsigned load = fieldFromInstruction(Insn, 21, 1);
2929   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2930               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2931 }
2932 
2933 static DecodeStatus DecodeVLDST3Instruction(MCInst &Inst, unsigned Insn,
2934                                    uint64_t Address, const void *Decoder) {
2935   unsigned size = fieldFromInstruction(Insn, 6, 2);
2936   if (size == 3) return MCDisassembler::Fail;
2937 
2938   unsigned align = fieldFromInstruction(Insn, 4, 2);
2939   if (align & 2) return MCDisassembler::Fail;
2940 
2941   unsigned load = fieldFromInstruction(Insn, 21, 1);
2942   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2943               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2944 }
2945 
2946 static DecodeStatus DecodeVLDST4Instruction(MCInst &Inst, unsigned Insn,
2947                                    uint64_t Address, const void *Decoder) {
2948   unsigned size = fieldFromInstruction(Insn, 6, 2);
2949   if (size == 3) return MCDisassembler::Fail;
2950 
2951   unsigned load = fieldFromInstruction(Insn, 21, 1);
2952   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2953               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2954 }
2955 
2956 static DecodeStatus DecodeVSTInstruction(MCInst &Inst, unsigned Insn,
2957                                  uint64_t Address, const void *Decoder) {
2958   DecodeStatus S = MCDisassembler::Success;
2959 
2960   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2961   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
2962   unsigned wb = fieldFromInstruction(Insn, 16, 4);
2963   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2964   Rn |= fieldFromInstruction(Insn, 4, 2) << 4;
2965   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2966 
2967   // Writeback Operand
2968   switch (Inst.getOpcode()) {
2969     case ARM::VST1d8wb_fixed:
2970     case ARM::VST1d16wb_fixed:
2971     case ARM::VST1d32wb_fixed:
2972     case ARM::VST1d64wb_fixed:
2973     case ARM::VST1d8wb_register:
2974     case ARM::VST1d16wb_register:
2975     case ARM::VST1d32wb_register:
2976     case ARM::VST1d64wb_register:
2977     case ARM::VST1q8wb_fixed:
2978     case ARM::VST1q16wb_fixed:
2979     case ARM::VST1q32wb_fixed:
2980     case ARM::VST1q64wb_fixed:
2981     case ARM::VST1q8wb_register:
2982     case ARM::VST1q16wb_register:
2983     case ARM::VST1q32wb_register:
2984     case ARM::VST1q64wb_register:
2985     case ARM::VST1d8Twb_fixed:
2986     case ARM::VST1d16Twb_fixed:
2987     case ARM::VST1d32Twb_fixed:
2988     case ARM::VST1d64Twb_fixed:
2989     case ARM::VST1d8Twb_register:
2990     case ARM::VST1d16Twb_register:
2991     case ARM::VST1d32Twb_register:
2992     case ARM::VST1d64Twb_register:
2993     case ARM::VST1d8Qwb_fixed:
2994     case ARM::VST1d16Qwb_fixed:
2995     case ARM::VST1d32Qwb_fixed:
2996     case ARM::VST1d64Qwb_fixed:
2997     case ARM::VST1d8Qwb_register:
2998     case ARM::VST1d16Qwb_register:
2999     case ARM::VST1d32Qwb_register:
3000     case ARM::VST1d64Qwb_register:
3001     case ARM::VST2d8wb_fixed:
3002     case ARM::VST2d16wb_fixed:
3003     case ARM::VST2d32wb_fixed:
3004     case ARM::VST2d8wb_register:
3005     case ARM::VST2d16wb_register:
3006     case ARM::VST2d32wb_register:
3007     case ARM::VST2q8wb_fixed:
3008     case ARM::VST2q16wb_fixed:
3009     case ARM::VST2q32wb_fixed:
3010     case ARM::VST2q8wb_register:
3011     case ARM::VST2q16wb_register:
3012     case ARM::VST2q32wb_register:
3013     case ARM::VST2b8wb_fixed:
3014     case ARM::VST2b16wb_fixed:
3015     case ARM::VST2b32wb_fixed:
3016     case ARM::VST2b8wb_register:
3017     case ARM::VST2b16wb_register:
3018     case ARM::VST2b32wb_register:
3019       if (Rm == 0xF)
3020         return MCDisassembler::Fail;
3021       Inst.addOperand(MCOperand::createImm(0));
3022       break;
3023     case ARM::VST3d8_UPD:
3024     case ARM::VST3d16_UPD:
3025     case ARM::VST3d32_UPD:
3026     case ARM::VST3q8_UPD:
3027     case ARM::VST3q16_UPD:
3028     case ARM::VST3q32_UPD:
3029     case ARM::VST4d8_UPD:
3030     case ARM::VST4d16_UPD:
3031     case ARM::VST4d32_UPD:
3032     case ARM::VST4q8_UPD:
3033     case ARM::VST4q16_UPD:
3034     case ARM::VST4q32_UPD:
3035       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
3036         return MCDisassembler::Fail;
3037       break;
3038     default:
3039       break;
3040   }
3041 
3042   // AddrMode6 Base (register+alignment)
3043   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
3044     return MCDisassembler::Fail;
3045 
3046   // AddrMode6 Offset (register)
3047   switch (Inst.getOpcode()) {
3048     default:
3049       if (Rm == 0xD)
3050         Inst.addOperand(MCOperand::createReg(0));
3051       else if (Rm != 0xF) {
3052         if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3053           return MCDisassembler::Fail;
3054       }
3055       break;
3056     case ARM::VST1d8wb_fixed:
3057     case ARM::VST1d16wb_fixed:
3058     case ARM::VST1d32wb_fixed:
3059     case ARM::VST1d64wb_fixed:
3060     case ARM::VST1q8wb_fixed:
3061     case ARM::VST1q16wb_fixed:
3062     case ARM::VST1q32wb_fixed:
3063     case ARM::VST1q64wb_fixed:
3064     case ARM::VST1d8Twb_fixed:
3065     case ARM::VST1d16Twb_fixed:
3066     case ARM::VST1d32Twb_fixed:
3067     case ARM::VST1d64Twb_fixed:
3068     case ARM::VST1d8Qwb_fixed:
3069     case ARM::VST1d16Qwb_fixed:
3070     case ARM::VST1d32Qwb_fixed:
3071     case ARM::VST1d64Qwb_fixed:
3072     case ARM::VST2d8wb_fixed:
3073     case ARM::VST2d16wb_fixed:
3074     case ARM::VST2d32wb_fixed:
3075     case ARM::VST2q8wb_fixed:
3076     case ARM::VST2q16wb_fixed:
3077     case ARM::VST2q32wb_fixed:
3078     case ARM::VST2b8wb_fixed:
3079     case ARM::VST2b16wb_fixed:
3080     case ARM::VST2b32wb_fixed:
3081       break;
3082   }
3083 
3084   // First input register
3085   switch (Inst.getOpcode()) {
3086   case ARM::VST1q16:
3087   case ARM::VST1q32:
3088   case ARM::VST1q64:
3089   case ARM::VST1q8:
3090   case ARM::VST1q16wb_fixed:
3091   case ARM::VST1q16wb_register:
3092   case ARM::VST1q32wb_fixed:
3093   case ARM::VST1q32wb_register:
3094   case ARM::VST1q64wb_fixed:
3095   case ARM::VST1q64wb_register:
3096   case ARM::VST1q8wb_fixed:
3097   case ARM::VST1q8wb_register:
3098   case ARM::VST2d16:
3099   case ARM::VST2d32:
3100   case ARM::VST2d8:
3101   case ARM::VST2d16wb_fixed:
3102   case ARM::VST2d16wb_register:
3103   case ARM::VST2d32wb_fixed:
3104   case ARM::VST2d32wb_register:
3105   case ARM::VST2d8wb_fixed:
3106   case ARM::VST2d8wb_register:
3107     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3108       return MCDisassembler::Fail;
3109     break;
3110   case ARM::VST2b16:
3111   case ARM::VST2b32:
3112   case ARM::VST2b8:
3113   case ARM::VST2b16wb_fixed:
3114   case ARM::VST2b16wb_register:
3115   case ARM::VST2b32wb_fixed:
3116   case ARM::VST2b32wb_register:
3117   case ARM::VST2b8wb_fixed:
3118   case ARM::VST2b8wb_register:
3119     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
3120       return MCDisassembler::Fail;
3121     break;
3122   default:
3123     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3124       return MCDisassembler::Fail;
3125   }
3126 
3127   // Second input register
3128   switch (Inst.getOpcode()) {
3129     case ARM::VST3d8:
3130     case ARM::VST3d16:
3131     case ARM::VST3d32:
3132     case ARM::VST3d8_UPD:
3133     case ARM::VST3d16_UPD:
3134     case ARM::VST3d32_UPD:
3135     case ARM::VST4d8:
3136     case ARM::VST4d16:
3137     case ARM::VST4d32:
3138     case ARM::VST4d8_UPD:
3139     case ARM::VST4d16_UPD:
3140     case ARM::VST4d32_UPD:
3141       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
3142         return MCDisassembler::Fail;
3143       break;
3144     case ARM::VST3q8:
3145     case ARM::VST3q16:
3146     case ARM::VST3q32:
3147     case ARM::VST3q8_UPD:
3148     case ARM::VST3q16_UPD:
3149     case ARM::VST3q32_UPD:
3150     case ARM::VST4q8:
3151     case ARM::VST4q16:
3152     case ARM::VST4q32:
3153     case ARM::VST4q8_UPD:
3154     case ARM::VST4q16_UPD:
3155     case ARM::VST4q32_UPD:
3156       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
3157         return MCDisassembler::Fail;
3158       break;
3159     default:
3160       break;
3161   }
3162 
3163   // Third input register
3164   switch (Inst.getOpcode()) {
3165     case ARM::VST3d8:
3166     case ARM::VST3d16:
3167     case ARM::VST3d32:
3168     case ARM::VST3d8_UPD:
3169     case ARM::VST3d16_UPD:
3170     case ARM::VST3d32_UPD:
3171     case ARM::VST4d8:
3172     case ARM::VST4d16:
3173     case ARM::VST4d32:
3174     case ARM::VST4d8_UPD:
3175     case ARM::VST4d16_UPD:
3176     case ARM::VST4d32_UPD:
3177       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
3178         return MCDisassembler::Fail;
3179       break;
3180     case ARM::VST3q8:
3181     case ARM::VST3q16:
3182     case ARM::VST3q32:
3183     case ARM::VST3q8_UPD:
3184     case ARM::VST3q16_UPD:
3185     case ARM::VST3q32_UPD:
3186     case ARM::VST4q8:
3187     case ARM::VST4q16:
3188     case ARM::VST4q32:
3189     case ARM::VST4q8_UPD:
3190     case ARM::VST4q16_UPD:
3191     case ARM::VST4q32_UPD:
3192       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
3193         return MCDisassembler::Fail;
3194       break;
3195     default:
3196       break;
3197   }
3198 
3199   // Fourth input register
3200   switch (Inst.getOpcode()) {
3201     case ARM::VST4d8:
3202     case ARM::VST4d16:
3203     case ARM::VST4d32:
3204     case ARM::VST4d8_UPD:
3205     case ARM::VST4d16_UPD:
3206     case ARM::VST4d32_UPD:
3207       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
3208         return MCDisassembler::Fail;
3209       break;
3210     case ARM::VST4q8:
3211     case ARM::VST4q16:
3212     case ARM::VST4q32:
3213     case ARM::VST4q8_UPD:
3214     case ARM::VST4q16_UPD:
3215     case ARM::VST4q32_UPD:
3216       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
3217         return MCDisassembler::Fail;
3218       break;
3219     default:
3220       break;
3221   }
3222 
3223   return S;
3224 }
3225 
3226 static DecodeStatus DecodeVLD1DupInstruction(MCInst &Inst, unsigned Insn,
3227                                     uint64_t Address, const void *Decoder) {
3228   DecodeStatus S = MCDisassembler::Success;
3229 
3230   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3231   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3232   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3233   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3234   unsigned align = fieldFromInstruction(Insn, 4, 1);
3235   unsigned size = fieldFromInstruction(Insn, 6, 2);
3236 
3237   if (size == 0 && align == 1)
3238     return MCDisassembler::Fail;
3239   align *= (1 << size);
3240 
3241   switch (Inst.getOpcode()) {
3242   case ARM::VLD1DUPq16: case ARM::VLD1DUPq32: case ARM::VLD1DUPq8:
3243   case ARM::VLD1DUPq16wb_fixed: case ARM::VLD1DUPq16wb_register:
3244   case ARM::VLD1DUPq32wb_fixed: case ARM::VLD1DUPq32wb_register:
3245   case ARM::VLD1DUPq8wb_fixed: case ARM::VLD1DUPq8wb_register:
3246     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3247       return MCDisassembler::Fail;
3248     break;
3249   default:
3250     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3251       return MCDisassembler::Fail;
3252     break;
3253   }
3254   if (Rm != 0xF) {
3255     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3256       return MCDisassembler::Fail;
3257   }
3258 
3259   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3260     return MCDisassembler::Fail;
3261   Inst.addOperand(MCOperand::createImm(align));
3262 
3263   // The fixed offset post-increment encodes Rm == 0xd. The no-writeback
3264   // variant encodes Rm == 0xf. Anything else is a register offset post-
3265   // increment and we need to add the register operand to the instruction.
3266   if (Rm != 0xD && Rm != 0xF &&
3267       !Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3268     return MCDisassembler::Fail;
3269 
3270   return S;
3271 }
3272 
3273 static DecodeStatus DecodeVLD2DupInstruction(MCInst &Inst, unsigned Insn,
3274                                     uint64_t Address, const void *Decoder) {
3275   DecodeStatus S = MCDisassembler::Success;
3276 
3277   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3278   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3279   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3280   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3281   unsigned align = fieldFromInstruction(Insn, 4, 1);
3282   unsigned size = 1 << fieldFromInstruction(Insn, 6, 2);
3283   align *= 2*size;
3284 
3285   switch (Inst.getOpcode()) {
3286   case ARM::VLD2DUPd16: case ARM::VLD2DUPd32: case ARM::VLD2DUPd8:
3287   case ARM::VLD2DUPd16wb_fixed: case ARM::VLD2DUPd16wb_register:
3288   case ARM::VLD2DUPd32wb_fixed: case ARM::VLD2DUPd32wb_register:
3289   case ARM::VLD2DUPd8wb_fixed: case ARM::VLD2DUPd8wb_register:
3290     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3291       return MCDisassembler::Fail;
3292     break;
3293   case ARM::VLD2DUPd16x2: case ARM::VLD2DUPd32x2: case ARM::VLD2DUPd8x2:
3294   case ARM::VLD2DUPd16x2wb_fixed: case ARM::VLD2DUPd16x2wb_register:
3295   case ARM::VLD2DUPd32x2wb_fixed: case ARM::VLD2DUPd32x2wb_register:
3296   case ARM::VLD2DUPd8x2wb_fixed: case ARM::VLD2DUPd8x2wb_register:
3297     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
3298       return MCDisassembler::Fail;
3299     break;
3300   default:
3301     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3302       return MCDisassembler::Fail;
3303     break;
3304   }
3305 
3306   if (Rm != 0xF)
3307     Inst.addOperand(MCOperand::createImm(0));
3308 
3309   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3310     return MCDisassembler::Fail;
3311   Inst.addOperand(MCOperand::createImm(align));
3312 
3313   if (Rm != 0xD && Rm != 0xF) {
3314     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3315       return MCDisassembler::Fail;
3316   }
3317 
3318   return S;
3319 }
3320 
3321 static DecodeStatus DecodeVLD3DupInstruction(MCInst &Inst, unsigned Insn,
3322                                     uint64_t Address, const void *Decoder) {
3323   DecodeStatus S = MCDisassembler::Success;
3324 
3325   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3326   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3327   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3328   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3329   unsigned inc = fieldFromInstruction(Insn, 5, 1) + 1;
3330 
3331   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3332     return MCDisassembler::Fail;
3333   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
3334     return MCDisassembler::Fail;
3335   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
3336     return MCDisassembler::Fail;
3337   if (Rm != 0xF) {
3338     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3339       return MCDisassembler::Fail;
3340   }
3341 
3342   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3343     return MCDisassembler::Fail;
3344   Inst.addOperand(MCOperand::createImm(0));
3345 
3346   if (Rm == 0xD)
3347     Inst.addOperand(MCOperand::createReg(0));
3348   else if (Rm != 0xF) {
3349     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3350       return MCDisassembler::Fail;
3351   }
3352 
3353   return S;
3354 }
3355 
3356 static DecodeStatus DecodeVLD4DupInstruction(MCInst &Inst, unsigned Insn,
3357                                     uint64_t Address, const void *Decoder) {
3358   DecodeStatus S = MCDisassembler::Success;
3359 
3360   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3361   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3362   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3363   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3364   unsigned size = fieldFromInstruction(Insn, 6, 2);
3365   unsigned inc = fieldFromInstruction(Insn, 5, 1) + 1;
3366   unsigned align = fieldFromInstruction(Insn, 4, 1);
3367 
3368   if (size == 0x3) {
3369     if (align == 0)
3370       return MCDisassembler::Fail;
3371     align = 16;
3372   } else {
3373     if (size == 2) {
3374       align *= 8;
3375     } else {
3376       size = 1 << size;
3377       align *= 4*size;
3378     }
3379   }
3380 
3381   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3382     return MCDisassembler::Fail;
3383   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
3384     return MCDisassembler::Fail;
3385   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
3386     return MCDisassembler::Fail;
3387   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3*inc)%32, Address, Decoder)))
3388     return MCDisassembler::Fail;
3389   if (Rm != 0xF) {
3390     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3391       return MCDisassembler::Fail;
3392   }
3393 
3394   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3395     return MCDisassembler::Fail;
3396   Inst.addOperand(MCOperand::createImm(align));
3397 
3398   if (Rm == 0xD)
3399     Inst.addOperand(MCOperand::createReg(0));
3400   else if (Rm != 0xF) {
3401     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3402       return MCDisassembler::Fail;
3403   }
3404 
3405   return S;
3406 }
3407 
3408 static DecodeStatus
3409 DecodeNEONModImmInstruction(MCInst &Inst, unsigned Insn,
3410                             uint64_t Address, const void *Decoder) {
3411   DecodeStatus S = MCDisassembler::Success;
3412 
3413   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3414   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3415   unsigned imm = fieldFromInstruction(Insn, 0, 4);
3416   imm |= fieldFromInstruction(Insn, 16, 3) << 4;
3417   imm |= fieldFromInstruction(Insn, 24, 1) << 7;
3418   imm |= fieldFromInstruction(Insn, 8, 4) << 8;
3419   imm |= fieldFromInstruction(Insn, 5, 1) << 12;
3420   unsigned Q = fieldFromInstruction(Insn, 6, 1);
3421 
3422   if (Q) {
3423     if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3424     return MCDisassembler::Fail;
3425   } else {
3426     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3427     return MCDisassembler::Fail;
3428   }
3429 
3430   Inst.addOperand(MCOperand::createImm(imm));
3431 
3432   switch (Inst.getOpcode()) {
3433     case ARM::VORRiv4i16:
3434     case ARM::VORRiv2i32:
3435     case ARM::VBICiv4i16:
3436     case ARM::VBICiv2i32:
3437       if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3438         return MCDisassembler::Fail;
3439       break;
3440     case ARM::VORRiv8i16:
3441     case ARM::VORRiv4i32:
3442     case ARM::VBICiv8i16:
3443     case ARM::VBICiv4i32:
3444       if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3445         return MCDisassembler::Fail;
3446       break;
3447     default:
3448       break;
3449   }
3450 
3451   return S;
3452 }
3453 
3454 static DecodeStatus
3455 DecodeMVEModImmInstruction(MCInst &Inst, unsigned Insn,
3456                            uint64_t Address, const void *Decoder) {
3457   DecodeStatus S = MCDisassembler::Success;
3458 
3459   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
3460                  fieldFromInstruction(Insn, 13, 3));
3461   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
3462   unsigned imm = fieldFromInstruction(Insn, 0, 4);
3463   imm |= fieldFromInstruction(Insn, 16, 3) << 4;
3464   imm |= fieldFromInstruction(Insn, 28, 1) << 7;
3465   imm |= cmode                             << 8;
3466   imm |= fieldFromInstruction(Insn, 5, 1)  << 12;
3467 
3468   if (cmode == 0xF && Inst.getOpcode() == ARM::MVE_VMVNimmi32)
3469     return MCDisassembler::Fail;
3470 
3471   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
3472     return MCDisassembler::Fail;
3473 
3474   Inst.addOperand(MCOperand::createImm(imm));
3475 
3476   Inst.addOperand(MCOperand::createImm(ARMVCC::None));
3477   Inst.addOperand(MCOperand::createReg(0));
3478   Inst.addOperand(MCOperand::createImm(0));
3479 
3480   return S;
3481 }
3482 
3483 static DecodeStatus DecodeMVEVADCInstruction(MCInst &Inst, unsigned Insn,
3484                                uint64_t Address, const void *Decoder) {
3485   DecodeStatus S = MCDisassembler::Success;
3486 
3487   unsigned Qd = fieldFromInstruction(Insn, 13, 3);
3488   Qd |= fieldFromInstruction(Insn, 22, 1) << 3;
3489   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
3490     return MCDisassembler::Fail;
3491   Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
3492 
3493   unsigned Qn = fieldFromInstruction(Insn, 17, 3);
3494   Qn |= fieldFromInstruction(Insn, 7, 1) << 3;
3495   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qn, Address, Decoder)))
3496     return MCDisassembler::Fail;
3497   unsigned Qm = fieldFromInstruction(Insn, 1, 3);
3498   Qm |= fieldFromInstruction(Insn, 5, 1) << 3;
3499   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
3500     return MCDisassembler::Fail;
3501   if (!fieldFromInstruction(Insn, 12, 1)) // I bit clear => need input FPSCR
3502     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
3503   Inst.addOperand(MCOperand::createImm(Qd));
3504 
3505   return S;
3506 }
3507 
3508 static DecodeStatus DecodeVSHLMaxInstruction(MCInst &Inst, unsigned Insn,
3509                                         uint64_t Address, const void *Decoder) {
3510   DecodeStatus S = MCDisassembler::Success;
3511 
3512   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3513   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3514   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3515   Rm |= fieldFromInstruction(Insn, 5, 1) << 4;
3516   unsigned size = fieldFromInstruction(Insn, 18, 2);
3517 
3518   if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3519     return MCDisassembler::Fail;
3520   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
3521     return MCDisassembler::Fail;
3522   Inst.addOperand(MCOperand::createImm(8 << size));
3523 
3524   return S;
3525 }
3526 
3527 static DecodeStatus DecodeShiftRight8Imm(MCInst &Inst, unsigned Val,
3528                                uint64_t Address, const void *Decoder) {
3529   Inst.addOperand(MCOperand::createImm(8 - Val));
3530   return MCDisassembler::Success;
3531 }
3532 
3533 static DecodeStatus DecodeShiftRight16Imm(MCInst &Inst, unsigned Val,
3534                                uint64_t Address, const void *Decoder) {
3535   Inst.addOperand(MCOperand::createImm(16 - Val));
3536   return MCDisassembler::Success;
3537 }
3538 
3539 static DecodeStatus DecodeShiftRight32Imm(MCInst &Inst, unsigned Val,
3540                                uint64_t Address, const void *Decoder) {
3541   Inst.addOperand(MCOperand::createImm(32 - Val));
3542   return MCDisassembler::Success;
3543 }
3544 
3545 static DecodeStatus DecodeShiftRight64Imm(MCInst &Inst, unsigned Val,
3546                                uint64_t Address, const void *Decoder) {
3547   Inst.addOperand(MCOperand::createImm(64 - Val));
3548   return MCDisassembler::Success;
3549 }
3550 
3551 static DecodeStatus DecodeTBLInstruction(MCInst &Inst, unsigned Insn,
3552                                uint64_t Address, const void *Decoder) {
3553   DecodeStatus S = MCDisassembler::Success;
3554 
3555   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3556   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3557   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3558   Rn |= fieldFromInstruction(Insn, 7, 1) << 4;
3559   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3560   Rm |= fieldFromInstruction(Insn, 5, 1) << 4;
3561   unsigned op = fieldFromInstruction(Insn, 6, 1);
3562 
3563   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3564     return MCDisassembler::Fail;
3565   if (op) {
3566     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3567     return MCDisassembler::Fail; // Writeback
3568   }
3569 
3570   switch (Inst.getOpcode()) {
3571   case ARM::VTBL2:
3572   case ARM::VTBX2:
3573     if (!Check(S, DecodeDPairRegisterClass(Inst, Rn, Address, Decoder)))
3574       return MCDisassembler::Fail;
3575     break;
3576   default:
3577     if (!Check(S, DecodeDPRRegisterClass(Inst, Rn, Address, Decoder)))
3578       return MCDisassembler::Fail;
3579   }
3580 
3581   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
3582     return MCDisassembler::Fail;
3583 
3584   return S;
3585 }
3586 
3587 static DecodeStatus DecodeThumbAddSpecialReg(MCInst &Inst, uint16_t Insn,
3588                                      uint64_t Address, const void *Decoder) {
3589   DecodeStatus S = MCDisassembler::Success;
3590 
3591   unsigned dst = fieldFromInstruction(Insn, 8, 3);
3592   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3593 
3594   if (!Check(S, DecodetGPRRegisterClass(Inst, dst, Address, Decoder)))
3595     return MCDisassembler::Fail;
3596 
3597   switch(Inst.getOpcode()) {
3598     default:
3599       return MCDisassembler::Fail;
3600     case ARM::tADR:
3601       break; // tADR does not explicitly represent the PC as an operand.
3602     case ARM::tADDrSPi:
3603       Inst.addOperand(MCOperand::createReg(ARM::SP));
3604       break;
3605   }
3606 
3607   Inst.addOperand(MCOperand::createImm(imm));
3608   return S;
3609 }
3610 
3611 static DecodeStatus DecodeThumbBROperand(MCInst &Inst, unsigned Val,
3612                                  uint64_t Address, const void *Decoder) {
3613   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<12>(Val<<1) + 4,
3614                                 true, 2, Inst, Decoder))
3615     Inst.addOperand(MCOperand::createImm(SignExtend32<12>(Val << 1)));
3616   return MCDisassembler::Success;
3617 }
3618 
3619 static DecodeStatus DecodeT2BROperand(MCInst &Inst, unsigned Val,
3620                                  uint64_t Address, const void *Decoder) {
3621   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<21>(Val) + 4,
3622                                 true, 4, Inst, Decoder))
3623     Inst.addOperand(MCOperand::createImm(SignExtend32<21>(Val)));
3624   return MCDisassembler::Success;
3625 }
3626 
3627 static DecodeStatus DecodeThumbCmpBROperand(MCInst &Inst, unsigned Val,
3628                                  uint64_t Address, const void *Decoder) {
3629   if (!tryAddingSymbolicOperand(Address, Address + (Val<<1) + 4,
3630                                 true, 2, Inst, Decoder))
3631     Inst.addOperand(MCOperand::createImm(Val << 1));
3632   return MCDisassembler::Success;
3633 }
3634 
3635 static DecodeStatus DecodeThumbAddrModeRR(MCInst &Inst, unsigned Val,
3636                                  uint64_t Address, const void *Decoder) {
3637   DecodeStatus S = MCDisassembler::Success;
3638 
3639   unsigned Rn = fieldFromInstruction(Val, 0, 3);
3640   unsigned Rm = fieldFromInstruction(Val, 3, 3);
3641 
3642   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
3643     return MCDisassembler::Fail;
3644   if (!Check(S, DecodetGPRRegisterClass(Inst, Rm, Address, Decoder)))
3645     return MCDisassembler::Fail;
3646 
3647   return S;
3648 }
3649 
3650 static DecodeStatus DecodeThumbAddrModeIS(MCInst &Inst, unsigned Val,
3651                                   uint64_t Address, const void *Decoder) {
3652   DecodeStatus S = MCDisassembler::Success;
3653 
3654   unsigned Rn = fieldFromInstruction(Val, 0, 3);
3655   unsigned imm = fieldFromInstruction(Val, 3, 5);
3656 
3657   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
3658     return MCDisassembler::Fail;
3659   Inst.addOperand(MCOperand::createImm(imm));
3660 
3661   return S;
3662 }
3663 
3664 static DecodeStatus DecodeThumbAddrModePC(MCInst &Inst, unsigned Val,
3665                                   uint64_t Address, const void *Decoder) {
3666   unsigned imm = Val << 2;
3667 
3668   Inst.addOperand(MCOperand::createImm(imm));
3669   tryAddingPcLoadReferenceComment(Address, (Address & ~2u) + imm + 4, Decoder);
3670 
3671   return MCDisassembler::Success;
3672 }
3673 
3674 static DecodeStatus DecodeThumbAddrModeSP(MCInst &Inst, unsigned Val,
3675                                   uint64_t Address, const void *Decoder) {
3676   Inst.addOperand(MCOperand::createReg(ARM::SP));
3677   Inst.addOperand(MCOperand::createImm(Val));
3678 
3679   return MCDisassembler::Success;
3680 }
3681 
3682 static DecodeStatus DecodeT2AddrModeSOReg(MCInst &Inst, unsigned Val,
3683                                   uint64_t Address, const void *Decoder) {
3684   DecodeStatus S = MCDisassembler::Success;
3685 
3686   unsigned Rn = fieldFromInstruction(Val, 6, 4);
3687   unsigned Rm = fieldFromInstruction(Val, 2, 4);
3688   unsigned imm = fieldFromInstruction(Val, 0, 2);
3689 
3690   // Thumb stores cannot use PC as dest register.
3691   switch (Inst.getOpcode()) {
3692   case ARM::t2STRHs:
3693   case ARM::t2STRBs:
3694   case ARM::t2STRs:
3695     if (Rn == 15)
3696       return MCDisassembler::Fail;
3697     break;
3698   default:
3699     break;
3700   }
3701 
3702   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3703     return MCDisassembler::Fail;
3704   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
3705     return MCDisassembler::Fail;
3706   Inst.addOperand(MCOperand::createImm(imm));
3707 
3708   return S;
3709 }
3710 
3711 static DecodeStatus DecodeT2LoadShift(MCInst &Inst, unsigned Insn,
3712                               uint64_t Address, const void *Decoder) {
3713   DecodeStatus S = MCDisassembler::Success;
3714 
3715   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3716   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3717 
3718   const FeatureBitset &featureBits =
3719     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3720 
3721   bool hasMP = featureBits[ARM::FeatureMP];
3722   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3723 
3724   if (Rn == 15) {
3725     switch (Inst.getOpcode()) {
3726     case ARM::t2LDRBs:
3727       Inst.setOpcode(ARM::t2LDRBpci);
3728       break;
3729     case ARM::t2LDRHs:
3730       Inst.setOpcode(ARM::t2LDRHpci);
3731       break;
3732     case ARM::t2LDRSHs:
3733       Inst.setOpcode(ARM::t2LDRSHpci);
3734       break;
3735     case ARM::t2LDRSBs:
3736       Inst.setOpcode(ARM::t2LDRSBpci);
3737       break;
3738     case ARM::t2LDRs:
3739       Inst.setOpcode(ARM::t2LDRpci);
3740       break;
3741     case ARM::t2PLDs:
3742       Inst.setOpcode(ARM::t2PLDpci);
3743       break;
3744     case ARM::t2PLIs:
3745       Inst.setOpcode(ARM::t2PLIpci);
3746       break;
3747     default:
3748       return MCDisassembler::Fail;
3749     }
3750 
3751     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3752   }
3753 
3754   if (Rt == 15) {
3755     switch (Inst.getOpcode()) {
3756     case ARM::t2LDRSHs:
3757       return MCDisassembler::Fail;
3758     case ARM::t2LDRHs:
3759       Inst.setOpcode(ARM::t2PLDWs);
3760       break;
3761     case ARM::t2LDRSBs:
3762       Inst.setOpcode(ARM::t2PLIs);
3763       break;
3764     default:
3765       break;
3766     }
3767   }
3768 
3769   switch (Inst.getOpcode()) {
3770     case ARM::t2PLDs:
3771       break;
3772     case ARM::t2PLIs:
3773       if (!hasV7Ops)
3774         return MCDisassembler::Fail;
3775       break;
3776     case ARM::t2PLDWs:
3777       if (!hasV7Ops || !hasMP)
3778         return MCDisassembler::Fail;
3779       break;
3780     default:
3781       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3782         return MCDisassembler::Fail;
3783   }
3784 
3785   unsigned addrmode = fieldFromInstruction(Insn, 4, 2);
3786   addrmode |= fieldFromInstruction(Insn, 0, 4) << 2;
3787   addrmode |= fieldFromInstruction(Insn, 16, 4) << 6;
3788   if (!Check(S, DecodeT2AddrModeSOReg(Inst, addrmode, Address, Decoder)))
3789     return MCDisassembler::Fail;
3790 
3791   return S;
3792 }
3793 
3794 static DecodeStatus DecodeT2LoadImm8(MCInst &Inst, unsigned Insn,
3795                                 uint64_t Address, const void* Decoder) {
3796   DecodeStatus S = MCDisassembler::Success;
3797 
3798   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3799   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3800   unsigned U = fieldFromInstruction(Insn, 9, 1);
3801   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3802   imm |= (U << 8);
3803   imm |= (Rn << 9);
3804   unsigned add = fieldFromInstruction(Insn, 9, 1);
3805 
3806   const FeatureBitset &featureBits =
3807     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3808 
3809   bool hasMP = featureBits[ARM::FeatureMP];
3810   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3811 
3812   if (Rn == 15) {
3813     switch (Inst.getOpcode()) {
3814     case ARM::t2LDRi8:
3815       Inst.setOpcode(ARM::t2LDRpci);
3816       break;
3817     case ARM::t2LDRBi8:
3818       Inst.setOpcode(ARM::t2LDRBpci);
3819       break;
3820     case ARM::t2LDRSBi8:
3821       Inst.setOpcode(ARM::t2LDRSBpci);
3822       break;
3823     case ARM::t2LDRHi8:
3824       Inst.setOpcode(ARM::t2LDRHpci);
3825       break;
3826     case ARM::t2LDRSHi8:
3827       Inst.setOpcode(ARM::t2LDRSHpci);
3828       break;
3829     case ARM::t2PLDi8:
3830       Inst.setOpcode(ARM::t2PLDpci);
3831       break;
3832     case ARM::t2PLIi8:
3833       Inst.setOpcode(ARM::t2PLIpci);
3834       break;
3835     default:
3836       return MCDisassembler::Fail;
3837     }
3838     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3839   }
3840 
3841   if (Rt == 15) {
3842     switch (Inst.getOpcode()) {
3843     case ARM::t2LDRSHi8:
3844       return MCDisassembler::Fail;
3845     case ARM::t2LDRHi8:
3846       if (!add)
3847         Inst.setOpcode(ARM::t2PLDWi8);
3848       break;
3849     case ARM::t2LDRSBi8:
3850       Inst.setOpcode(ARM::t2PLIi8);
3851       break;
3852     default:
3853       break;
3854     }
3855   }
3856 
3857   switch (Inst.getOpcode()) {
3858   case ARM::t2PLDi8:
3859     break;
3860   case ARM::t2PLIi8:
3861     if (!hasV7Ops)
3862       return MCDisassembler::Fail;
3863     break;
3864   case ARM::t2PLDWi8:
3865       if (!hasV7Ops || !hasMP)
3866         return MCDisassembler::Fail;
3867       break;
3868   default:
3869     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3870       return MCDisassembler::Fail;
3871   }
3872 
3873   if (!Check(S, DecodeT2AddrModeImm8(Inst, imm, Address, Decoder)))
3874     return MCDisassembler::Fail;
3875   return S;
3876 }
3877 
3878 static DecodeStatus DecodeT2LoadImm12(MCInst &Inst, unsigned Insn,
3879                                 uint64_t Address, const void* Decoder) {
3880   DecodeStatus S = MCDisassembler::Success;
3881 
3882   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3883   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3884   unsigned imm = fieldFromInstruction(Insn, 0, 12);
3885   imm |= (Rn << 13);
3886 
3887   const FeatureBitset &featureBits =
3888     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3889 
3890   bool hasMP = featureBits[ARM::FeatureMP];
3891   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3892 
3893   if (Rn == 15) {
3894     switch (Inst.getOpcode()) {
3895     case ARM::t2LDRi12:
3896       Inst.setOpcode(ARM::t2LDRpci);
3897       break;
3898     case ARM::t2LDRHi12:
3899       Inst.setOpcode(ARM::t2LDRHpci);
3900       break;
3901     case ARM::t2LDRSHi12:
3902       Inst.setOpcode(ARM::t2LDRSHpci);
3903       break;
3904     case ARM::t2LDRBi12:
3905       Inst.setOpcode(ARM::t2LDRBpci);
3906       break;
3907     case ARM::t2LDRSBi12:
3908       Inst.setOpcode(ARM::t2LDRSBpci);
3909       break;
3910     case ARM::t2PLDi12:
3911       Inst.setOpcode(ARM::t2PLDpci);
3912       break;
3913     case ARM::t2PLIi12:
3914       Inst.setOpcode(ARM::t2PLIpci);
3915       break;
3916     default:
3917       return MCDisassembler::Fail;
3918     }
3919     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3920   }
3921 
3922   if (Rt == 15) {
3923     switch (Inst.getOpcode()) {
3924     case ARM::t2LDRSHi12:
3925       return MCDisassembler::Fail;
3926     case ARM::t2LDRHi12:
3927       Inst.setOpcode(ARM::t2PLDWi12);
3928       break;
3929     case ARM::t2LDRSBi12:
3930       Inst.setOpcode(ARM::t2PLIi12);
3931       break;
3932     default:
3933       break;
3934     }
3935   }
3936 
3937   switch (Inst.getOpcode()) {
3938   case ARM::t2PLDi12:
3939     break;
3940   case ARM::t2PLIi12:
3941     if (!hasV7Ops)
3942       return MCDisassembler::Fail;
3943     break;
3944   case ARM::t2PLDWi12:
3945       if (!hasV7Ops || !hasMP)
3946         return MCDisassembler::Fail;
3947       break;
3948   default:
3949     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3950       return MCDisassembler::Fail;
3951   }
3952 
3953   if (!Check(S, DecodeT2AddrModeImm12(Inst, imm, Address, Decoder)))
3954     return MCDisassembler::Fail;
3955   return S;
3956 }
3957 
3958 static DecodeStatus DecodeT2LoadT(MCInst &Inst, unsigned Insn,
3959                                 uint64_t Address, const void* Decoder) {
3960   DecodeStatus S = MCDisassembler::Success;
3961 
3962   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3963   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3964   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3965   imm |= (Rn << 9);
3966 
3967   if (Rn == 15) {
3968     switch (Inst.getOpcode()) {
3969     case ARM::t2LDRT:
3970       Inst.setOpcode(ARM::t2LDRpci);
3971       break;
3972     case ARM::t2LDRBT:
3973       Inst.setOpcode(ARM::t2LDRBpci);
3974       break;
3975     case ARM::t2LDRHT:
3976       Inst.setOpcode(ARM::t2LDRHpci);
3977       break;
3978     case ARM::t2LDRSBT:
3979       Inst.setOpcode(ARM::t2LDRSBpci);
3980       break;
3981     case ARM::t2LDRSHT:
3982       Inst.setOpcode(ARM::t2LDRSHpci);
3983       break;
3984     default:
3985       return MCDisassembler::Fail;
3986     }
3987     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3988   }
3989 
3990   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
3991     return MCDisassembler::Fail;
3992   if (!Check(S, DecodeT2AddrModeImm8(Inst, imm, Address, Decoder)))
3993     return MCDisassembler::Fail;
3994   return S;
3995 }
3996 
3997 static DecodeStatus DecodeT2LoadLabel(MCInst &Inst, unsigned Insn,
3998                                 uint64_t Address, const void* Decoder) {
3999   DecodeStatus S = MCDisassembler::Success;
4000 
4001   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4002   unsigned U = fieldFromInstruction(Insn, 23, 1);
4003   int imm = fieldFromInstruction(Insn, 0, 12);
4004 
4005   const FeatureBitset &featureBits =
4006     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4007 
4008   bool hasV7Ops = featureBits[ARM::HasV7Ops];
4009 
4010   if (Rt == 15) {
4011     switch (Inst.getOpcode()) {
4012       case ARM::t2LDRBpci:
4013       case ARM::t2LDRHpci:
4014         Inst.setOpcode(ARM::t2PLDpci);
4015         break;
4016       case ARM::t2LDRSBpci:
4017         Inst.setOpcode(ARM::t2PLIpci);
4018         break;
4019       case ARM::t2LDRSHpci:
4020         return MCDisassembler::Fail;
4021       default:
4022         break;
4023     }
4024   }
4025 
4026   switch(Inst.getOpcode()) {
4027   case ARM::t2PLDpci:
4028     break;
4029   case ARM::t2PLIpci:
4030     if (!hasV7Ops)
4031       return MCDisassembler::Fail;
4032     break;
4033   default:
4034     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4035       return MCDisassembler::Fail;
4036   }
4037 
4038   if (!U) {
4039     // Special case for #-0.
4040     if (imm == 0)
4041       imm = INT32_MIN;
4042     else
4043       imm = -imm;
4044   }
4045   Inst.addOperand(MCOperand::createImm(imm));
4046 
4047   return S;
4048 }
4049 
4050 static DecodeStatus DecodeT2Imm8S4(MCInst &Inst, unsigned Val,
4051                            uint64_t Address, const void *Decoder) {
4052   if (Val == 0)
4053     Inst.addOperand(MCOperand::createImm(INT32_MIN));
4054   else {
4055     int imm = Val & 0xFF;
4056 
4057     if (!(Val & 0x100)) imm *= -1;
4058     Inst.addOperand(MCOperand::createImm(imm * 4));
4059   }
4060 
4061   return MCDisassembler::Success;
4062 }
4063 
4064 static DecodeStatus DecodeT2Imm7S4(MCInst &Inst, unsigned Val, uint64_t Address,
4065                                    const void *Decoder) {
4066   if (Val == 0)
4067     Inst.addOperand(MCOperand::createImm(INT32_MIN));
4068   else {
4069     int imm = Val & 0x7F;
4070 
4071     if (!(Val & 0x80))
4072       imm *= -1;
4073     Inst.addOperand(MCOperand::createImm(imm * 4));
4074   }
4075 
4076   return MCDisassembler::Success;
4077 }
4078 
4079 static DecodeStatus DecodeT2AddrModeImm8s4(MCInst &Inst, unsigned Val,
4080                                    uint64_t Address, const void *Decoder) {
4081   DecodeStatus S = MCDisassembler::Success;
4082 
4083   unsigned Rn = fieldFromInstruction(Val, 9, 4);
4084   unsigned imm = fieldFromInstruction(Val, 0, 9);
4085 
4086   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4087     return MCDisassembler::Fail;
4088   if (!Check(S, DecodeT2Imm8S4(Inst, imm, Address, Decoder)))
4089     return MCDisassembler::Fail;
4090 
4091   return S;
4092 }
4093 
4094 static DecodeStatus DecodeT2AddrModeImm7s4(MCInst &Inst, unsigned Val,
4095                                            uint64_t Address,
4096                                            const void *Decoder) {
4097   DecodeStatus S = MCDisassembler::Success;
4098 
4099   unsigned Rn = fieldFromInstruction(Val, 8, 4);
4100   unsigned imm = fieldFromInstruction(Val, 0, 8);
4101 
4102   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4103     return MCDisassembler::Fail;
4104   if (!Check(S, DecodeT2Imm7S4(Inst, imm, Address, Decoder)))
4105     return MCDisassembler::Fail;
4106 
4107   return S;
4108 }
4109 
4110 static DecodeStatus DecodeT2AddrModeImm0_1020s4(MCInst &Inst,unsigned Val,
4111                                    uint64_t Address, const void *Decoder) {
4112   DecodeStatus S = MCDisassembler::Success;
4113 
4114   unsigned Rn = fieldFromInstruction(Val, 8, 4);
4115   unsigned imm = fieldFromInstruction(Val, 0, 8);
4116 
4117   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4118     return MCDisassembler::Fail;
4119 
4120   Inst.addOperand(MCOperand::createImm(imm));
4121 
4122   return S;
4123 }
4124 
4125 static DecodeStatus DecodeT2Imm8(MCInst &Inst, unsigned Val,
4126                          uint64_t Address, const void *Decoder) {
4127   int imm = Val & 0xFF;
4128   if (Val == 0)
4129     imm = INT32_MIN;
4130   else if (!(Val & 0x100))
4131     imm *= -1;
4132   Inst.addOperand(MCOperand::createImm(imm));
4133 
4134   return MCDisassembler::Success;
4135 }
4136 
4137 static DecodeStatus DecodeT2AddrModeImm8(MCInst &Inst, unsigned Val,
4138                                  uint64_t Address, const void *Decoder) {
4139   DecodeStatus S = MCDisassembler::Success;
4140 
4141   unsigned Rn = fieldFromInstruction(Val, 9, 4);
4142   unsigned imm = fieldFromInstruction(Val, 0, 9);
4143 
4144   // Thumb stores cannot use PC as dest register.
4145   switch (Inst.getOpcode()) {
4146   case ARM::t2STRT:
4147   case ARM::t2STRBT:
4148   case ARM::t2STRHT:
4149   case ARM::t2STRi8:
4150   case ARM::t2STRHi8:
4151   case ARM::t2STRBi8:
4152     if (Rn == 15)
4153       return MCDisassembler::Fail;
4154     break;
4155   default:
4156     break;
4157   }
4158 
4159   // Some instructions always use an additive offset.
4160   switch (Inst.getOpcode()) {
4161     case ARM::t2LDRT:
4162     case ARM::t2LDRBT:
4163     case ARM::t2LDRHT:
4164     case ARM::t2LDRSBT:
4165     case ARM::t2LDRSHT:
4166     case ARM::t2STRT:
4167     case ARM::t2STRBT:
4168     case ARM::t2STRHT:
4169       imm |= 0x100;
4170       break;
4171     default:
4172       break;
4173   }
4174 
4175   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4176     return MCDisassembler::Fail;
4177   if (!Check(S, DecodeT2Imm8(Inst, imm, Address, Decoder)))
4178     return MCDisassembler::Fail;
4179 
4180   return S;
4181 }
4182 
4183 static DecodeStatus DecodeT2LdStPre(MCInst &Inst, unsigned Insn,
4184                                     uint64_t Address, const void *Decoder) {
4185   DecodeStatus S = MCDisassembler::Success;
4186 
4187   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4188   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4189   unsigned addr = fieldFromInstruction(Insn, 0, 8);
4190   addr |= fieldFromInstruction(Insn, 9, 1) << 8;
4191   addr |= Rn << 9;
4192   unsigned load = fieldFromInstruction(Insn, 20, 1);
4193 
4194   if (Rn == 15) {
4195     switch (Inst.getOpcode()) {
4196     case ARM::t2LDR_PRE:
4197     case ARM::t2LDR_POST:
4198       Inst.setOpcode(ARM::t2LDRpci);
4199       break;
4200     case ARM::t2LDRB_PRE:
4201     case ARM::t2LDRB_POST:
4202       Inst.setOpcode(ARM::t2LDRBpci);
4203       break;
4204     case ARM::t2LDRH_PRE:
4205     case ARM::t2LDRH_POST:
4206       Inst.setOpcode(ARM::t2LDRHpci);
4207       break;
4208     case ARM::t2LDRSB_PRE:
4209     case ARM::t2LDRSB_POST:
4210       if (Rt == 15)
4211         Inst.setOpcode(ARM::t2PLIpci);
4212       else
4213         Inst.setOpcode(ARM::t2LDRSBpci);
4214       break;
4215     case ARM::t2LDRSH_PRE:
4216     case ARM::t2LDRSH_POST:
4217       Inst.setOpcode(ARM::t2LDRSHpci);
4218       break;
4219     default:
4220       return MCDisassembler::Fail;
4221     }
4222     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
4223   }
4224 
4225   if (!load) {
4226     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4227       return MCDisassembler::Fail;
4228   }
4229 
4230   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4231     return MCDisassembler::Fail;
4232 
4233   if (load) {
4234     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4235       return MCDisassembler::Fail;
4236   }
4237 
4238   if (!Check(S, DecodeT2AddrModeImm8(Inst, addr, Address, Decoder)))
4239     return MCDisassembler::Fail;
4240 
4241   return S;
4242 }
4243 
4244 static DecodeStatus DecodeT2AddrModeImm12(MCInst &Inst, unsigned Val,
4245                                   uint64_t Address, const void *Decoder) {
4246   DecodeStatus S = MCDisassembler::Success;
4247 
4248   unsigned Rn = fieldFromInstruction(Val, 13, 4);
4249   unsigned imm = fieldFromInstruction(Val, 0, 12);
4250 
4251   // Thumb stores cannot use PC as dest register.
4252   switch (Inst.getOpcode()) {
4253   case ARM::t2STRi12:
4254   case ARM::t2STRBi12:
4255   case ARM::t2STRHi12:
4256     if (Rn == 15)
4257       return MCDisassembler::Fail;
4258     break;
4259   default:
4260     break;
4261   }
4262 
4263   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4264     return MCDisassembler::Fail;
4265   Inst.addOperand(MCOperand::createImm(imm));
4266 
4267   return S;
4268 }
4269 
4270 static DecodeStatus DecodeThumbAddSPImm(MCInst &Inst, uint16_t Insn,
4271                                 uint64_t Address, const void *Decoder) {
4272   unsigned imm = fieldFromInstruction(Insn, 0, 7);
4273 
4274   Inst.addOperand(MCOperand::createReg(ARM::SP));
4275   Inst.addOperand(MCOperand::createReg(ARM::SP));
4276   Inst.addOperand(MCOperand::createImm(imm));
4277 
4278   return MCDisassembler::Success;
4279 }
4280 
4281 static DecodeStatus DecodeThumbAddSPReg(MCInst &Inst, uint16_t Insn,
4282                                 uint64_t Address, const void *Decoder) {
4283   DecodeStatus S = MCDisassembler::Success;
4284 
4285   if (Inst.getOpcode() == ARM::tADDrSP) {
4286     unsigned Rdm = fieldFromInstruction(Insn, 0, 3);
4287     Rdm |= fieldFromInstruction(Insn, 7, 1) << 3;
4288 
4289     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
4290     return MCDisassembler::Fail;
4291     Inst.addOperand(MCOperand::createReg(ARM::SP));
4292     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
4293     return MCDisassembler::Fail;
4294   } else if (Inst.getOpcode() == ARM::tADDspr) {
4295     unsigned Rm = fieldFromInstruction(Insn, 3, 4);
4296 
4297     Inst.addOperand(MCOperand::createReg(ARM::SP));
4298     Inst.addOperand(MCOperand::createReg(ARM::SP));
4299     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4300     return MCDisassembler::Fail;
4301   }
4302 
4303   return S;
4304 }
4305 
4306 static DecodeStatus DecodeThumbCPS(MCInst &Inst, uint16_t Insn,
4307                            uint64_t Address, const void *Decoder) {
4308   unsigned imod = fieldFromInstruction(Insn, 4, 1) | 0x2;
4309   unsigned flags = fieldFromInstruction(Insn, 0, 3);
4310 
4311   Inst.addOperand(MCOperand::createImm(imod));
4312   Inst.addOperand(MCOperand::createImm(flags));
4313 
4314   return MCDisassembler::Success;
4315 }
4316 
4317 static DecodeStatus DecodePostIdxReg(MCInst &Inst, unsigned Insn,
4318                              uint64_t Address, const void *Decoder) {
4319   DecodeStatus S = MCDisassembler::Success;
4320   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4321   unsigned add = fieldFromInstruction(Insn, 4, 1);
4322 
4323   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
4324     return MCDisassembler::Fail;
4325   Inst.addOperand(MCOperand::createImm(add));
4326 
4327   return S;
4328 }
4329 
4330 static DecodeStatus DecodeThumbBLXOffset(MCInst &Inst, unsigned Val,
4331                                  uint64_t Address, const void *Decoder) {
4332   // Val is passed in as S:J1:J2:imm10H:imm10L:'0'
4333   // Note only one trailing zero not two.  Also the J1 and J2 values are from
4334   // the encoded instruction.  So here change to I1 and I2 values via:
4335   // I1 = NOT(J1 EOR S);
4336   // I2 = NOT(J2 EOR S);
4337   // and build the imm32 with two trailing zeros as documented:
4338   // imm32 = SignExtend(S:I1:I2:imm10H:imm10L:'00', 32);
4339   unsigned S = (Val >> 23) & 1;
4340   unsigned J1 = (Val >> 22) & 1;
4341   unsigned J2 = (Val >> 21) & 1;
4342   unsigned I1 = !(J1 ^ S);
4343   unsigned I2 = !(J2 ^ S);
4344   unsigned tmp = (Val & ~0x600000) | (I1 << 22) | (I2 << 21);
4345   int imm32 = SignExtend32<25>(tmp << 1);
4346 
4347   if (!tryAddingSymbolicOperand(Address,
4348                                 (Address & ~2u) + imm32 + 4,
4349                                 true, 4, Inst, Decoder))
4350     Inst.addOperand(MCOperand::createImm(imm32));
4351   return MCDisassembler::Success;
4352 }
4353 
4354 static DecodeStatus DecodeCoprocessor(MCInst &Inst, unsigned Val,
4355                               uint64_t Address, const void *Decoder) {
4356   if (Val == 0xA || Val == 0xB)
4357     return MCDisassembler::Fail;
4358 
4359   const FeatureBitset &featureBits =
4360     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4361 
4362   if (featureBits[ARM::HasV8Ops] && !(Val == 14 || Val == 15))
4363     return MCDisassembler::Fail;
4364 
4365   // For Armv8.1-M Mainline coprocessors matching 100x,101x or 111x should
4366   // decode as VFP/MVE instructions.
4367   if (featureBits[ARM::HasV8_1MMainlineOps] &&
4368       ((Val & 0xE) == 0x8 || (Val & 0xE) == 0xA ||
4369        (Val & 0xE) == 0xE))
4370     return MCDisassembler::Fail;
4371 
4372   Inst.addOperand(MCOperand::createImm(Val));
4373   return MCDisassembler::Success;
4374 }
4375 
4376 static DecodeStatus
4377 DecodeThumbTableBranch(MCInst &Inst, unsigned Insn,
4378                        uint64_t Address, const void *Decoder) {
4379   DecodeStatus S = MCDisassembler::Success;
4380 
4381   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4382   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4383 
4384   if (Rn == ARM::SP) S = MCDisassembler::SoftFail;
4385   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4386     return MCDisassembler::Fail;
4387   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
4388     return MCDisassembler::Fail;
4389   return S;
4390 }
4391 
4392 static DecodeStatus
4393 DecodeThumb2BCCInstruction(MCInst &Inst, unsigned Insn,
4394                            uint64_t Address, const void *Decoder) {
4395   DecodeStatus S = MCDisassembler::Success;
4396 
4397   unsigned pred = fieldFromInstruction(Insn, 22, 4);
4398   if (pred == 0xE || pred == 0xF) {
4399     unsigned opc = fieldFromInstruction(Insn, 4, 28);
4400     switch (opc) {
4401       default:
4402         return MCDisassembler::Fail;
4403       case 0xf3bf8f4:
4404         Inst.setOpcode(ARM::t2DSB);
4405         break;
4406       case 0xf3bf8f5:
4407         Inst.setOpcode(ARM::t2DMB);
4408         break;
4409       case 0xf3bf8f6:
4410         Inst.setOpcode(ARM::t2ISB);
4411         break;
4412     }
4413 
4414     unsigned imm = fieldFromInstruction(Insn, 0, 4);
4415     return DecodeMemBarrierOption(Inst, imm, Address, Decoder);
4416   }
4417 
4418   unsigned brtarget = fieldFromInstruction(Insn, 0, 11) << 1;
4419   brtarget |= fieldFromInstruction(Insn, 11, 1) << 19;
4420   brtarget |= fieldFromInstruction(Insn, 13, 1) << 18;
4421   brtarget |= fieldFromInstruction(Insn, 16, 6) << 12;
4422   brtarget |= fieldFromInstruction(Insn, 26, 1) << 20;
4423 
4424   if (!Check(S, DecodeT2BROperand(Inst, brtarget, Address, Decoder)))
4425     return MCDisassembler::Fail;
4426   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4427     return MCDisassembler::Fail;
4428 
4429   return S;
4430 }
4431 
4432 // Decode a shifted immediate operand.  These basically consist
4433 // of an 8-bit value, and a 4-bit directive that specifies either
4434 // a splat operation or a rotation.
4435 static DecodeStatus DecodeT2SOImm(MCInst &Inst, unsigned Val,
4436                           uint64_t Address, const void *Decoder) {
4437   unsigned ctrl = fieldFromInstruction(Val, 10, 2);
4438   if (ctrl == 0) {
4439     unsigned byte = fieldFromInstruction(Val, 8, 2);
4440     unsigned imm = fieldFromInstruction(Val, 0, 8);
4441     switch (byte) {
4442       case 0:
4443         Inst.addOperand(MCOperand::createImm(imm));
4444         break;
4445       case 1:
4446         Inst.addOperand(MCOperand::createImm((imm << 16) | imm));
4447         break;
4448       case 2:
4449         Inst.addOperand(MCOperand::createImm((imm << 24) | (imm << 8)));
4450         break;
4451       case 3:
4452         Inst.addOperand(MCOperand::createImm((imm << 24) | (imm << 16) |
4453                                              (imm << 8)  |  imm));
4454         break;
4455     }
4456   } else {
4457     unsigned unrot = fieldFromInstruction(Val, 0, 7) | 0x80;
4458     unsigned rot = fieldFromInstruction(Val, 7, 5);
4459     unsigned imm = (unrot >> rot) | (unrot << ((32-rot)&31));
4460     Inst.addOperand(MCOperand::createImm(imm));
4461   }
4462 
4463   return MCDisassembler::Success;
4464 }
4465 
4466 static DecodeStatus
4467 DecodeThumbBCCTargetOperand(MCInst &Inst, unsigned Val,
4468                             uint64_t Address, const void *Decoder) {
4469   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<9>(Val<<1) + 4,
4470                                 true, 2, Inst, Decoder))
4471     Inst.addOperand(MCOperand::createImm(SignExtend32<9>(Val << 1)));
4472   return MCDisassembler::Success;
4473 }
4474 
4475 static DecodeStatus DecodeThumbBLTargetOperand(MCInst &Inst, unsigned Val,
4476                                                uint64_t Address,
4477                                                const void *Decoder) {
4478   // Val is passed in as S:J1:J2:imm10:imm11
4479   // Note no trailing zero after imm11.  Also the J1 and J2 values are from
4480   // the encoded instruction.  So here change to I1 and I2 values via:
4481   // I1 = NOT(J1 EOR S);
4482   // I2 = NOT(J2 EOR S);
4483   // and build the imm32 with one trailing zero as documented:
4484   // imm32 = SignExtend(S:I1:I2:imm10:imm11:'0', 32);
4485   unsigned S = (Val >> 23) & 1;
4486   unsigned J1 = (Val >> 22) & 1;
4487   unsigned J2 = (Val >> 21) & 1;
4488   unsigned I1 = !(J1 ^ S);
4489   unsigned I2 = !(J2 ^ S);
4490   unsigned tmp = (Val & ~0x600000) | (I1 << 22) | (I2 << 21);
4491   int imm32 = SignExtend32<25>(tmp << 1);
4492 
4493   if (!tryAddingSymbolicOperand(Address, Address + imm32 + 4,
4494                                 true, 4, Inst, Decoder))
4495     Inst.addOperand(MCOperand::createImm(imm32));
4496   return MCDisassembler::Success;
4497 }
4498 
4499 static DecodeStatus DecodeMemBarrierOption(MCInst &Inst, unsigned Val,
4500                                    uint64_t Address, const void *Decoder) {
4501   if (Val & ~0xf)
4502     return MCDisassembler::Fail;
4503 
4504   Inst.addOperand(MCOperand::createImm(Val));
4505   return MCDisassembler::Success;
4506 }
4507 
4508 static DecodeStatus DecodeInstSyncBarrierOption(MCInst &Inst, unsigned Val,
4509                                         uint64_t Address, const void *Decoder) {
4510   if (Val & ~0xf)
4511     return MCDisassembler::Fail;
4512 
4513   Inst.addOperand(MCOperand::createImm(Val));
4514   return MCDisassembler::Success;
4515 }
4516 
4517 static DecodeStatus DecodeMSRMask(MCInst &Inst, unsigned Val,
4518                           uint64_t Address, const void *Decoder) {
4519   DecodeStatus S = MCDisassembler::Success;
4520   const FeatureBitset &FeatureBits =
4521     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4522 
4523   if (FeatureBits[ARM::FeatureMClass]) {
4524     unsigned ValLow = Val & 0xff;
4525 
4526     // Validate the SYSm value first.
4527     switch (ValLow) {
4528     case  0: // apsr
4529     case  1: // iapsr
4530     case  2: // eapsr
4531     case  3: // xpsr
4532     case  5: // ipsr
4533     case  6: // epsr
4534     case  7: // iepsr
4535     case  8: // msp
4536     case  9: // psp
4537     case 16: // primask
4538     case 20: // control
4539       break;
4540     case 17: // basepri
4541     case 18: // basepri_max
4542     case 19: // faultmask
4543       if (!(FeatureBits[ARM::HasV7Ops]))
4544         // Values basepri, basepri_max and faultmask are only valid for v7m.
4545         return MCDisassembler::Fail;
4546       break;
4547     case 0x8a: // msplim_ns
4548     case 0x8b: // psplim_ns
4549     case 0x91: // basepri_ns
4550     case 0x93: // faultmask_ns
4551       if (!(FeatureBits[ARM::HasV8MMainlineOps]))
4552         return MCDisassembler::Fail;
4553       LLVM_FALLTHROUGH;
4554     case 10:   // msplim
4555     case 11:   // psplim
4556     case 0x88: // msp_ns
4557     case 0x89: // psp_ns
4558     case 0x90: // primask_ns
4559     case 0x94: // control_ns
4560     case 0x98: // sp_ns
4561       if (!(FeatureBits[ARM::Feature8MSecExt]))
4562         return MCDisassembler::Fail;
4563       break;
4564     default:
4565       // Architecturally defined as unpredictable
4566       S = MCDisassembler::SoftFail;
4567       break;
4568     }
4569 
4570     if (Inst.getOpcode() == ARM::t2MSR_M) {
4571       unsigned Mask = fieldFromInstruction(Val, 10, 2);
4572       if (!(FeatureBits[ARM::HasV7Ops])) {
4573         // The ARMv6-M MSR bits {11-10} can be only 0b10, other values are
4574         // unpredictable.
4575         if (Mask != 2)
4576           S = MCDisassembler::SoftFail;
4577       }
4578       else {
4579         // The ARMv7-M architecture stores an additional 2-bit mask value in
4580         // MSR bits {11-10}. The mask is used only with apsr, iapsr, eapsr and
4581         // xpsr, it has to be 0b10 in other cases. Bit mask{1} indicates if
4582         // the NZCVQ bits should be moved by the instruction. Bit mask{0}
4583         // indicates the move for the GE{3:0} bits, the mask{0} bit can be set
4584         // only if the processor includes the DSP extension.
4585         if (Mask == 0 || (Mask != 2 && ValLow > 3) ||
4586             (!(FeatureBits[ARM::FeatureDSP]) && (Mask & 1)))
4587           S = MCDisassembler::SoftFail;
4588       }
4589     }
4590   } else {
4591     // A/R class
4592     if (Val == 0)
4593       return MCDisassembler::Fail;
4594   }
4595   Inst.addOperand(MCOperand::createImm(Val));
4596   return S;
4597 }
4598 
4599 static DecodeStatus DecodeBankedReg(MCInst &Inst, unsigned Val,
4600                                     uint64_t Address, const void *Decoder) {
4601   unsigned R = fieldFromInstruction(Val, 5, 1);
4602   unsigned SysM = fieldFromInstruction(Val, 0, 5);
4603 
4604   // The table of encodings for these banked registers comes from B9.2.3 of the
4605   // ARM ARM. There are patterns, but nothing regular enough to make this logic
4606   // neater. So by fiat, these values are UNPREDICTABLE:
4607   if (!ARMBankedReg::lookupBankedRegByEncoding((R << 5) | SysM))
4608     return MCDisassembler::Fail;
4609 
4610   Inst.addOperand(MCOperand::createImm(Val));
4611   return MCDisassembler::Success;
4612 }
4613 
4614 static DecodeStatus DecodeDoubleRegLoad(MCInst &Inst, unsigned Insn,
4615                                         uint64_t Address, const void *Decoder) {
4616   DecodeStatus S = MCDisassembler::Success;
4617 
4618   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4619   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4620   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4621 
4622   if (Rn == 0xF)
4623     S = MCDisassembler::SoftFail;
4624 
4625   if (!Check(S, DecodeGPRPairRegisterClass(Inst, Rt, Address, Decoder)))
4626     return MCDisassembler::Fail;
4627   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4628     return MCDisassembler::Fail;
4629   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4630     return MCDisassembler::Fail;
4631 
4632   return S;
4633 }
4634 
4635 static DecodeStatus DecodeDoubleRegStore(MCInst &Inst, unsigned Insn,
4636                                          uint64_t Address,
4637                                          const void *Decoder) {
4638   DecodeStatus S = MCDisassembler::Success;
4639 
4640   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4641   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
4642   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4643   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4644 
4645   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
4646     return MCDisassembler::Fail;
4647 
4648   if (Rn == 0xF || Rd == Rn || Rd == Rt || Rd == Rt+1)
4649     S = MCDisassembler::SoftFail;
4650 
4651   if (!Check(S, DecodeGPRPairRegisterClass(Inst, Rt, Address, Decoder)))
4652     return MCDisassembler::Fail;
4653   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4654     return MCDisassembler::Fail;
4655   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4656     return MCDisassembler::Fail;
4657 
4658   return S;
4659 }
4660 
4661 static DecodeStatus DecodeLDRPreImm(MCInst &Inst, unsigned Insn,
4662                             uint64_t Address, const void *Decoder) {
4663   DecodeStatus S = MCDisassembler::Success;
4664 
4665   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4666   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4667   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4668   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4669   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4670   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4671 
4672   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4673 
4674   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4675     return MCDisassembler::Fail;
4676   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4677     return MCDisassembler::Fail;
4678   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
4679     return MCDisassembler::Fail;
4680   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4681     return MCDisassembler::Fail;
4682 
4683   return S;
4684 }
4685 
4686 static DecodeStatus DecodeLDRPreReg(MCInst &Inst, unsigned Insn,
4687                             uint64_t Address, const void *Decoder) {
4688   DecodeStatus S = MCDisassembler::Success;
4689 
4690   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4691   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4692   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4693   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4694   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4695   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4696   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4697 
4698   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4699   if (Rm == 0xF) S = MCDisassembler::SoftFail;
4700 
4701   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4702     return MCDisassembler::Fail;
4703   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4704     return MCDisassembler::Fail;
4705   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
4706     return MCDisassembler::Fail;
4707   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4708     return MCDisassembler::Fail;
4709 
4710   return S;
4711 }
4712 
4713 static DecodeStatus DecodeSTRPreImm(MCInst &Inst, unsigned Insn,
4714                             uint64_t Address, const void *Decoder) {
4715   DecodeStatus S = MCDisassembler::Success;
4716 
4717   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4718   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4719   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4720   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4721   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4722   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4723 
4724   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4725 
4726   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4727     return MCDisassembler::Fail;
4728   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4729     return MCDisassembler::Fail;
4730   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
4731     return MCDisassembler::Fail;
4732   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4733     return MCDisassembler::Fail;
4734 
4735   return S;
4736 }
4737 
4738 static DecodeStatus DecodeSTRPreReg(MCInst &Inst, unsigned Insn,
4739                             uint64_t Address, const void *Decoder) {
4740   DecodeStatus S = MCDisassembler::Success;
4741 
4742   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4743   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4744   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4745   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4746   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4747   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4748 
4749   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4750 
4751   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4752     return MCDisassembler::Fail;
4753   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4754     return MCDisassembler::Fail;
4755   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
4756     return MCDisassembler::Fail;
4757   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4758     return MCDisassembler::Fail;
4759 
4760   return S;
4761 }
4762 
4763 static DecodeStatus DecodeVLD1LN(MCInst &Inst, unsigned Insn,
4764                          uint64_t Address, const void *Decoder) {
4765   DecodeStatus S = MCDisassembler::Success;
4766 
4767   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4768   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4769   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4770   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4771   unsigned size = fieldFromInstruction(Insn, 10, 2);
4772 
4773   unsigned align = 0;
4774   unsigned index = 0;
4775   switch (size) {
4776     default:
4777       return MCDisassembler::Fail;
4778     case 0:
4779       if (fieldFromInstruction(Insn, 4, 1))
4780         return MCDisassembler::Fail; // UNDEFINED
4781       index = fieldFromInstruction(Insn, 5, 3);
4782       break;
4783     case 1:
4784       if (fieldFromInstruction(Insn, 5, 1))
4785         return MCDisassembler::Fail; // UNDEFINED
4786       index = fieldFromInstruction(Insn, 6, 2);
4787       if (fieldFromInstruction(Insn, 4, 1))
4788         align = 2;
4789       break;
4790     case 2:
4791       if (fieldFromInstruction(Insn, 6, 1))
4792         return MCDisassembler::Fail; // UNDEFINED
4793       index = fieldFromInstruction(Insn, 7, 1);
4794 
4795       switch (fieldFromInstruction(Insn, 4, 2)) {
4796         case 0 :
4797           align = 0; break;
4798         case 3:
4799           align = 4; break;
4800         default:
4801           return MCDisassembler::Fail;
4802       }
4803       break;
4804   }
4805 
4806   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4807     return MCDisassembler::Fail;
4808   if (Rm != 0xF) { // Writeback
4809     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4810       return MCDisassembler::Fail;
4811   }
4812   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4813     return MCDisassembler::Fail;
4814   Inst.addOperand(MCOperand::createImm(align));
4815   if (Rm != 0xF) {
4816     if (Rm != 0xD) {
4817       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4818         return MCDisassembler::Fail;
4819     } else
4820       Inst.addOperand(MCOperand::createReg(0));
4821   }
4822 
4823   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4824     return MCDisassembler::Fail;
4825   Inst.addOperand(MCOperand::createImm(index));
4826 
4827   return S;
4828 }
4829 
4830 static DecodeStatus DecodeVST1LN(MCInst &Inst, unsigned Insn,
4831                          uint64_t Address, const void *Decoder) {
4832   DecodeStatus S = MCDisassembler::Success;
4833 
4834   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4835   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4836   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4837   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4838   unsigned size = fieldFromInstruction(Insn, 10, 2);
4839 
4840   unsigned align = 0;
4841   unsigned index = 0;
4842   switch (size) {
4843     default:
4844       return MCDisassembler::Fail;
4845     case 0:
4846       if (fieldFromInstruction(Insn, 4, 1))
4847         return MCDisassembler::Fail; // UNDEFINED
4848       index = fieldFromInstruction(Insn, 5, 3);
4849       break;
4850     case 1:
4851       if (fieldFromInstruction(Insn, 5, 1))
4852         return MCDisassembler::Fail; // UNDEFINED
4853       index = fieldFromInstruction(Insn, 6, 2);
4854       if (fieldFromInstruction(Insn, 4, 1))
4855         align = 2;
4856       break;
4857     case 2:
4858       if (fieldFromInstruction(Insn, 6, 1))
4859         return MCDisassembler::Fail; // UNDEFINED
4860       index = fieldFromInstruction(Insn, 7, 1);
4861 
4862       switch (fieldFromInstruction(Insn, 4, 2)) {
4863         case 0:
4864           align = 0; break;
4865         case 3:
4866           align = 4; break;
4867         default:
4868           return MCDisassembler::Fail;
4869       }
4870       break;
4871   }
4872 
4873   if (Rm != 0xF) { // Writeback
4874     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4875     return MCDisassembler::Fail;
4876   }
4877   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4878     return MCDisassembler::Fail;
4879   Inst.addOperand(MCOperand::createImm(align));
4880   if (Rm != 0xF) {
4881     if (Rm != 0xD) {
4882       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4883     return MCDisassembler::Fail;
4884     } else
4885       Inst.addOperand(MCOperand::createReg(0));
4886   }
4887 
4888   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4889     return MCDisassembler::Fail;
4890   Inst.addOperand(MCOperand::createImm(index));
4891 
4892   return S;
4893 }
4894 
4895 static DecodeStatus DecodeVLD2LN(MCInst &Inst, unsigned Insn,
4896                          uint64_t Address, const void *Decoder) {
4897   DecodeStatus S = MCDisassembler::Success;
4898 
4899   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4900   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4901   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4902   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4903   unsigned size = fieldFromInstruction(Insn, 10, 2);
4904 
4905   unsigned align = 0;
4906   unsigned index = 0;
4907   unsigned inc = 1;
4908   switch (size) {
4909     default:
4910       return MCDisassembler::Fail;
4911     case 0:
4912       index = fieldFromInstruction(Insn, 5, 3);
4913       if (fieldFromInstruction(Insn, 4, 1))
4914         align = 2;
4915       break;
4916     case 1:
4917       index = fieldFromInstruction(Insn, 6, 2);
4918       if (fieldFromInstruction(Insn, 4, 1))
4919         align = 4;
4920       if (fieldFromInstruction(Insn, 5, 1))
4921         inc = 2;
4922       break;
4923     case 2:
4924       if (fieldFromInstruction(Insn, 5, 1))
4925         return MCDisassembler::Fail; // UNDEFINED
4926       index = fieldFromInstruction(Insn, 7, 1);
4927       if (fieldFromInstruction(Insn, 4, 1) != 0)
4928         align = 8;
4929       if (fieldFromInstruction(Insn, 6, 1))
4930         inc = 2;
4931       break;
4932   }
4933 
4934   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4935     return MCDisassembler::Fail;
4936   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4937     return MCDisassembler::Fail;
4938   if (Rm != 0xF) { // Writeback
4939     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4940       return MCDisassembler::Fail;
4941   }
4942   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4943     return MCDisassembler::Fail;
4944   Inst.addOperand(MCOperand::createImm(align));
4945   if (Rm != 0xF) {
4946     if (Rm != 0xD) {
4947       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4948         return MCDisassembler::Fail;
4949     } else
4950       Inst.addOperand(MCOperand::createReg(0));
4951   }
4952 
4953   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4954     return MCDisassembler::Fail;
4955   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4956     return MCDisassembler::Fail;
4957   Inst.addOperand(MCOperand::createImm(index));
4958 
4959   return S;
4960 }
4961 
4962 static DecodeStatus DecodeVST2LN(MCInst &Inst, unsigned Insn,
4963                          uint64_t Address, const void *Decoder) {
4964   DecodeStatus S = MCDisassembler::Success;
4965 
4966   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4967   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4968   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4969   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4970   unsigned size = fieldFromInstruction(Insn, 10, 2);
4971 
4972   unsigned align = 0;
4973   unsigned index = 0;
4974   unsigned inc = 1;
4975   switch (size) {
4976     default:
4977       return MCDisassembler::Fail;
4978     case 0:
4979       index = fieldFromInstruction(Insn, 5, 3);
4980       if (fieldFromInstruction(Insn, 4, 1))
4981         align = 2;
4982       break;
4983     case 1:
4984       index = fieldFromInstruction(Insn, 6, 2);
4985       if (fieldFromInstruction(Insn, 4, 1))
4986         align = 4;
4987       if (fieldFromInstruction(Insn, 5, 1))
4988         inc = 2;
4989       break;
4990     case 2:
4991       if (fieldFromInstruction(Insn, 5, 1))
4992         return MCDisassembler::Fail; // UNDEFINED
4993       index = fieldFromInstruction(Insn, 7, 1);
4994       if (fieldFromInstruction(Insn, 4, 1) != 0)
4995         align = 8;
4996       if (fieldFromInstruction(Insn, 6, 1))
4997         inc = 2;
4998       break;
4999   }
5000 
5001   if (Rm != 0xF) { // Writeback
5002     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5003       return MCDisassembler::Fail;
5004   }
5005   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5006     return MCDisassembler::Fail;
5007   Inst.addOperand(MCOperand::createImm(align));
5008   if (Rm != 0xF) {
5009     if (Rm != 0xD) {
5010       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5011         return MCDisassembler::Fail;
5012     } else
5013       Inst.addOperand(MCOperand::createReg(0));
5014   }
5015 
5016   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5017     return MCDisassembler::Fail;
5018   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5019     return MCDisassembler::Fail;
5020   Inst.addOperand(MCOperand::createImm(index));
5021 
5022   return S;
5023 }
5024 
5025 static DecodeStatus DecodeVLD3LN(MCInst &Inst, unsigned Insn,
5026                          uint64_t Address, const void *Decoder) {
5027   DecodeStatus S = MCDisassembler::Success;
5028 
5029   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5030   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5031   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5032   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5033   unsigned size = fieldFromInstruction(Insn, 10, 2);
5034 
5035   unsigned align = 0;
5036   unsigned index = 0;
5037   unsigned inc = 1;
5038   switch (size) {
5039     default:
5040       return MCDisassembler::Fail;
5041     case 0:
5042       if (fieldFromInstruction(Insn, 4, 1))
5043         return MCDisassembler::Fail; // UNDEFINED
5044       index = fieldFromInstruction(Insn, 5, 3);
5045       break;
5046     case 1:
5047       if (fieldFromInstruction(Insn, 4, 1))
5048         return MCDisassembler::Fail; // UNDEFINED
5049       index = fieldFromInstruction(Insn, 6, 2);
5050       if (fieldFromInstruction(Insn, 5, 1))
5051         inc = 2;
5052       break;
5053     case 2:
5054       if (fieldFromInstruction(Insn, 4, 2))
5055         return MCDisassembler::Fail; // UNDEFINED
5056       index = fieldFromInstruction(Insn, 7, 1);
5057       if (fieldFromInstruction(Insn, 6, 1))
5058         inc = 2;
5059       break;
5060   }
5061 
5062   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5063     return MCDisassembler::Fail;
5064   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5065     return MCDisassembler::Fail;
5066   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5067     return MCDisassembler::Fail;
5068 
5069   if (Rm != 0xF) { // Writeback
5070     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5071     return MCDisassembler::Fail;
5072   }
5073   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5074     return MCDisassembler::Fail;
5075   Inst.addOperand(MCOperand::createImm(align));
5076   if (Rm != 0xF) {
5077     if (Rm != 0xD) {
5078       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5079     return MCDisassembler::Fail;
5080     } else
5081       Inst.addOperand(MCOperand::createReg(0));
5082   }
5083 
5084   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5085     return MCDisassembler::Fail;
5086   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5087     return MCDisassembler::Fail;
5088   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5089     return MCDisassembler::Fail;
5090   Inst.addOperand(MCOperand::createImm(index));
5091 
5092   return S;
5093 }
5094 
5095 static DecodeStatus DecodeVST3LN(MCInst &Inst, unsigned Insn,
5096                          uint64_t Address, const void *Decoder) {
5097   DecodeStatus S = MCDisassembler::Success;
5098 
5099   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5100   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5101   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5102   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5103   unsigned size = fieldFromInstruction(Insn, 10, 2);
5104 
5105   unsigned align = 0;
5106   unsigned index = 0;
5107   unsigned inc = 1;
5108   switch (size) {
5109     default:
5110       return MCDisassembler::Fail;
5111     case 0:
5112       if (fieldFromInstruction(Insn, 4, 1))
5113         return MCDisassembler::Fail; // UNDEFINED
5114       index = fieldFromInstruction(Insn, 5, 3);
5115       break;
5116     case 1:
5117       if (fieldFromInstruction(Insn, 4, 1))
5118         return MCDisassembler::Fail; // UNDEFINED
5119       index = fieldFromInstruction(Insn, 6, 2);
5120       if (fieldFromInstruction(Insn, 5, 1))
5121         inc = 2;
5122       break;
5123     case 2:
5124       if (fieldFromInstruction(Insn, 4, 2))
5125         return MCDisassembler::Fail; // UNDEFINED
5126       index = fieldFromInstruction(Insn, 7, 1);
5127       if (fieldFromInstruction(Insn, 6, 1))
5128         inc = 2;
5129       break;
5130   }
5131 
5132   if (Rm != 0xF) { // Writeback
5133     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5134     return MCDisassembler::Fail;
5135   }
5136   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5137     return MCDisassembler::Fail;
5138   Inst.addOperand(MCOperand::createImm(align));
5139   if (Rm != 0xF) {
5140     if (Rm != 0xD) {
5141       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5142     return MCDisassembler::Fail;
5143     } else
5144       Inst.addOperand(MCOperand::createReg(0));
5145   }
5146 
5147   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5148     return MCDisassembler::Fail;
5149   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5150     return MCDisassembler::Fail;
5151   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5152     return MCDisassembler::Fail;
5153   Inst.addOperand(MCOperand::createImm(index));
5154 
5155   return S;
5156 }
5157 
5158 static DecodeStatus DecodeVLD4LN(MCInst &Inst, unsigned Insn,
5159                          uint64_t Address, const void *Decoder) {
5160   DecodeStatus S = MCDisassembler::Success;
5161 
5162   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5163   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5164   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5165   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5166   unsigned size = fieldFromInstruction(Insn, 10, 2);
5167 
5168   unsigned align = 0;
5169   unsigned index = 0;
5170   unsigned inc = 1;
5171   switch (size) {
5172     default:
5173       return MCDisassembler::Fail;
5174     case 0:
5175       if (fieldFromInstruction(Insn, 4, 1))
5176         align = 4;
5177       index = fieldFromInstruction(Insn, 5, 3);
5178       break;
5179     case 1:
5180       if (fieldFromInstruction(Insn, 4, 1))
5181         align = 8;
5182       index = fieldFromInstruction(Insn, 6, 2);
5183       if (fieldFromInstruction(Insn, 5, 1))
5184         inc = 2;
5185       break;
5186     case 2:
5187       switch (fieldFromInstruction(Insn, 4, 2)) {
5188         case 0:
5189           align = 0; break;
5190         case 3:
5191           return MCDisassembler::Fail;
5192         default:
5193           align = 4 << fieldFromInstruction(Insn, 4, 2); break;
5194       }
5195 
5196       index = fieldFromInstruction(Insn, 7, 1);
5197       if (fieldFromInstruction(Insn, 6, 1))
5198         inc = 2;
5199       break;
5200   }
5201 
5202   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5203     return MCDisassembler::Fail;
5204   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5205     return MCDisassembler::Fail;
5206   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5207     return MCDisassembler::Fail;
5208   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5209     return MCDisassembler::Fail;
5210 
5211   if (Rm != 0xF) { // Writeback
5212     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5213       return MCDisassembler::Fail;
5214   }
5215   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5216     return MCDisassembler::Fail;
5217   Inst.addOperand(MCOperand::createImm(align));
5218   if (Rm != 0xF) {
5219     if (Rm != 0xD) {
5220       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5221         return MCDisassembler::Fail;
5222     } else
5223       Inst.addOperand(MCOperand::createReg(0));
5224   }
5225 
5226   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5227     return MCDisassembler::Fail;
5228   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5229     return MCDisassembler::Fail;
5230   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5231     return MCDisassembler::Fail;
5232   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5233     return MCDisassembler::Fail;
5234   Inst.addOperand(MCOperand::createImm(index));
5235 
5236   return S;
5237 }
5238 
5239 static DecodeStatus DecodeVST4LN(MCInst &Inst, unsigned Insn,
5240                          uint64_t Address, const void *Decoder) {
5241   DecodeStatus S = MCDisassembler::Success;
5242 
5243   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5244   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5245   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5246   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5247   unsigned size = fieldFromInstruction(Insn, 10, 2);
5248 
5249   unsigned align = 0;
5250   unsigned index = 0;
5251   unsigned inc = 1;
5252   switch (size) {
5253     default:
5254       return MCDisassembler::Fail;
5255     case 0:
5256       if (fieldFromInstruction(Insn, 4, 1))
5257         align = 4;
5258       index = fieldFromInstruction(Insn, 5, 3);
5259       break;
5260     case 1:
5261       if (fieldFromInstruction(Insn, 4, 1))
5262         align = 8;
5263       index = fieldFromInstruction(Insn, 6, 2);
5264       if (fieldFromInstruction(Insn, 5, 1))
5265         inc = 2;
5266       break;
5267     case 2:
5268       switch (fieldFromInstruction(Insn, 4, 2)) {
5269         case 0:
5270           align = 0; break;
5271         case 3:
5272           return MCDisassembler::Fail;
5273         default:
5274           align = 4 << fieldFromInstruction(Insn, 4, 2); break;
5275       }
5276 
5277       index = fieldFromInstruction(Insn, 7, 1);
5278       if (fieldFromInstruction(Insn, 6, 1))
5279         inc = 2;
5280       break;
5281   }
5282 
5283   if (Rm != 0xF) { // Writeback
5284     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5285     return MCDisassembler::Fail;
5286   }
5287   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5288     return MCDisassembler::Fail;
5289   Inst.addOperand(MCOperand::createImm(align));
5290   if (Rm != 0xF) {
5291     if (Rm != 0xD) {
5292       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5293     return MCDisassembler::Fail;
5294     } else
5295       Inst.addOperand(MCOperand::createReg(0));
5296   }
5297 
5298   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5299     return MCDisassembler::Fail;
5300   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5301     return MCDisassembler::Fail;
5302   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5303     return MCDisassembler::Fail;
5304   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5305     return MCDisassembler::Fail;
5306   Inst.addOperand(MCOperand::createImm(index));
5307 
5308   return S;
5309 }
5310 
5311 static DecodeStatus DecodeVMOVSRR(MCInst &Inst, unsigned Insn,
5312                                   uint64_t Address, const void *Decoder) {
5313   DecodeStatus S = MCDisassembler::Success;
5314   unsigned Rt  = fieldFromInstruction(Insn, 12, 4);
5315   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
5316   unsigned Rm  = fieldFromInstruction(Insn,  5, 1);
5317   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5318   Rm |= fieldFromInstruction(Insn, 0, 4) << 1;
5319 
5320   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
5321     S = MCDisassembler::SoftFail;
5322 
5323   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
5324     return MCDisassembler::Fail;
5325   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
5326     return MCDisassembler::Fail;
5327   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
5328     return MCDisassembler::Fail;
5329   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
5330     return MCDisassembler::Fail;
5331   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5332     return MCDisassembler::Fail;
5333 
5334   return S;
5335 }
5336 
5337 static DecodeStatus DecodeVMOVRRS(MCInst &Inst, unsigned Insn,
5338                                   uint64_t Address, const void *Decoder) {
5339   DecodeStatus S = MCDisassembler::Success;
5340   unsigned Rt  = fieldFromInstruction(Insn, 12, 4);
5341   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
5342   unsigned Rm  = fieldFromInstruction(Insn,  5, 1);
5343   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5344   Rm |= fieldFromInstruction(Insn, 0, 4) << 1;
5345 
5346   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
5347     S = MCDisassembler::SoftFail;
5348 
5349   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
5350     return MCDisassembler::Fail;
5351   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
5352     return MCDisassembler::Fail;
5353   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
5354     return MCDisassembler::Fail;
5355   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
5356     return MCDisassembler::Fail;
5357   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5358     return MCDisassembler::Fail;
5359 
5360   return S;
5361 }
5362 
5363 static DecodeStatus DecodeIT(MCInst &Inst, unsigned Insn,
5364                              uint64_t Address, const void *Decoder) {
5365   DecodeStatus S = MCDisassembler::Success;
5366   unsigned pred = fieldFromInstruction(Insn, 4, 4);
5367   unsigned mask = fieldFromInstruction(Insn, 0, 4);
5368 
5369   if (pred == 0xF) {
5370     pred = 0xE;
5371     S = MCDisassembler::SoftFail;
5372   }
5373 
5374   if (mask == 0x0)
5375     return MCDisassembler::Fail;
5376 
5377   // IT masks are encoded as a sequence of replacement low-order bits
5378   // for the condition code. So if the low bit of the starting
5379   // condition code is 1, then we have to flip all the bits above the
5380   // terminating bit (which is the lowest 1 bit).
5381   if (pred & 1) {
5382     unsigned LowBit = mask & -mask;
5383     unsigned BitsAboveLowBit = 0xF & (-LowBit << 1);
5384     mask ^= BitsAboveLowBit;
5385   }
5386 
5387   Inst.addOperand(MCOperand::createImm(pred));
5388   Inst.addOperand(MCOperand::createImm(mask));
5389   return S;
5390 }
5391 
5392 static DecodeStatus
5393 DecodeT2LDRDPreInstruction(MCInst &Inst, unsigned Insn,
5394                            uint64_t Address, const void *Decoder) {
5395   DecodeStatus S = MCDisassembler::Success;
5396 
5397   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5398   unsigned Rt2 = fieldFromInstruction(Insn, 8, 4);
5399   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5400   unsigned addr = fieldFromInstruction(Insn, 0, 8);
5401   unsigned W = fieldFromInstruction(Insn, 21, 1);
5402   unsigned U = fieldFromInstruction(Insn, 23, 1);
5403   unsigned P = fieldFromInstruction(Insn, 24, 1);
5404   bool writeback = (W == 1) | (P == 0);
5405 
5406   addr |= (U << 8) | (Rn << 9);
5407 
5408   if (writeback && (Rn == Rt || Rn == Rt2))
5409     Check(S, MCDisassembler::SoftFail);
5410   if (Rt == Rt2)
5411     Check(S, MCDisassembler::SoftFail);
5412 
5413   // Rt
5414   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
5415     return MCDisassembler::Fail;
5416   // Rt2
5417   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
5418     return MCDisassembler::Fail;
5419   // Writeback operand
5420   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
5421     return MCDisassembler::Fail;
5422   // addr
5423   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
5424     return MCDisassembler::Fail;
5425 
5426   return S;
5427 }
5428 
5429 static DecodeStatus
5430 DecodeT2STRDPreInstruction(MCInst &Inst, unsigned Insn,
5431                            uint64_t Address, const void *Decoder) {
5432   DecodeStatus S = MCDisassembler::Success;
5433 
5434   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5435   unsigned Rt2 = fieldFromInstruction(Insn, 8, 4);
5436   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5437   unsigned addr = fieldFromInstruction(Insn, 0, 8);
5438   unsigned W = fieldFromInstruction(Insn, 21, 1);
5439   unsigned U = fieldFromInstruction(Insn, 23, 1);
5440   unsigned P = fieldFromInstruction(Insn, 24, 1);
5441   bool writeback = (W == 1) | (P == 0);
5442 
5443   addr |= (U << 8) | (Rn << 9);
5444 
5445   if (writeback && (Rn == Rt || Rn == Rt2))
5446     Check(S, MCDisassembler::SoftFail);
5447 
5448   // Writeback operand
5449   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
5450     return MCDisassembler::Fail;
5451   // Rt
5452   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
5453     return MCDisassembler::Fail;
5454   // Rt2
5455   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
5456     return MCDisassembler::Fail;
5457   // addr
5458   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
5459     return MCDisassembler::Fail;
5460 
5461   return S;
5462 }
5463 
5464 static DecodeStatus DecodeT2Adr(MCInst &Inst, uint32_t Insn,
5465                                 uint64_t Address, const void *Decoder) {
5466   unsigned sign1 = fieldFromInstruction(Insn, 21, 1);
5467   unsigned sign2 = fieldFromInstruction(Insn, 23, 1);
5468   if (sign1 != sign2) return MCDisassembler::Fail;
5469 
5470   unsigned Val = fieldFromInstruction(Insn, 0, 8);
5471   Val |= fieldFromInstruction(Insn, 12, 3) << 8;
5472   Val |= fieldFromInstruction(Insn, 26, 1) << 11;
5473   Val |= sign1 << 12;
5474   Inst.addOperand(MCOperand::createImm(SignExtend32<13>(Val)));
5475 
5476   return MCDisassembler::Success;
5477 }
5478 
5479 static DecodeStatus DecodeT2ShifterImmOperand(MCInst &Inst, uint32_t Val,
5480                                               uint64_t Address,
5481                                               const void *Decoder) {
5482   DecodeStatus S = MCDisassembler::Success;
5483 
5484   // Shift of "asr #32" is not allowed in Thumb2 mode.
5485   if (Val == 0x20) S = MCDisassembler::Fail;
5486   Inst.addOperand(MCOperand::createImm(Val));
5487   return S;
5488 }
5489 
5490 static DecodeStatus DecodeSwap(MCInst &Inst, unsigned Insn,
5491                                uint64_t Address, const void *Decoder) {
5492   unsigned Rt   = fieldFromInstruction(Insn, 12, 4);
5493   unsigned Rt2  = fieldFromInstruction(Insn, 0,  4);
5494   unsigned Rn   = fieldFromInstruction(Insn, 16, 4);
5495   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5496 
5497   if (pred == 0xF)
5498     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
5499 
5500   DecodeStatus S = MCDisassembler::Success;
5501 
5502   if (Rt == Rn || Rn == Rt2)
5503     S = MCDisassembler::SoftFail;
5504 
5505   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5506     return MCDisassembler::Fail;
5507   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5508     return MCDisassembler::Fail;
5509   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
5510     return MCDisassembler::Fail;
5511   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5512     return MCDisassembler::Fail;
5513 
5514   return S;
5515 }
5516 
5517 static DecodeStatus DecodeVCVTD(MCInst &Inst, unsigned Insn,
5518                                 uint64_t Address, const void *Decoder) {
5519   const FeatureBitset &featureBits =
5520       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5521   bool hasFullFP16 = featureBits[ARM::FeatureFullFP16];
5522 
5523   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5524   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5525   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5526   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5527   unsigned imm = fieldFromInstruction(Insn, 16, 6);
5528   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
5529   unsigned op = fieldFromInstruction(Insn, 5, 1);
5530 
5531   DecodeStatus S = MCDisassembler::Success;
5532 
5533   // If the top 3 bits of imm are clear, this is a VMOV (immediate)
5534   if (!(imm & 0x38)) {
5535     if (cmode == 0xF) {
5536       if (op == 1) return MCDisassembler::Fail;
5537       Inst.setOpcode(ARM::VMOVv2f32);
5538     }
5539     if (hasFullFP16) {
5540       if (cmode == 0xE) {
5541         if (op == 1) {
5542           Inst.setOpcode(ARM::VMOVv1i64);
5543         } else {
5544           Inst.setOpcode(ARM::VMOVv8i8);
5545         }
5546       }
5547       if (cmode == 0xD) {
5548         if (op == 1) {
5549           Inst.setOpcode(ARM::VMVNv2i32);
5550         } else {
5551           Inst.setOpcode(ARM::VMOVv2i32);
5552         }
5553       }
5554       if (cmode == 0xC) {
5555         if (op == 1) {
5556           Inst.setOpcode(ARM::VMVNv2i32);
5557         } else {
5558           Inst.setOpcode(ARM::VMOVv2i32);
5559         }
5560       }
5561     }
5562     return DecodeNEONModImmInstruction(Inst, Insn, Address, Decoder);
5563   }
5564 
5565   if (!(imm & 0x20)) return MCDisassembler::Fail;
5566 
5567   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
5568     return MCDisassembler::Fail;
5569   if (!Check(S, DecodeDPRRegisterClass(Inst, Vm, Address, Decoder)))
5570     return MCDisassembler::Fail;
5571   Inst.addOperand(MCOperand::createImm(64 - imm));
5572 
5573   return S;
5574 }
5575 
5576 static DecodeStatus DecodeVCVTQ(MCInst &Inst, unsigned Insn,
5577                                 uint64_t Address, const void *Decoder) {
5578   const FeatureBitset &featureBits =
5579       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5580   bool hasFullFP16 = featureBits[ARM::FeatureFullFP16];
5581 
5582   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5583   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5584   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5585   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5586   unsigned imm = fieldFromInstruction(Insn, 16, 6);
5587   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
5588   unsigned op = fieldFromInstruction(Insn, 5, 1);
5589 
5590   DecodeStatus S = MCDisassembler::Success;
5591 
5592   // If the top 3 bits of imm are clear, this is a VMOV (immediate)
5593   if (!(imm & 0x38)) {
5594     if (cmode == 0xF) {
5595       if (op == 1) return MCDisassembler::Fail;
5596       Inst.setOpcode(ARM::VMOVv4f32);
5597     }
5598     if (hasFullFP16) {
5599       if (cmode == 0xE) {
5600         if (op == 1) {
5601           Inst.setOpcode(ARM::VMOVv2i64);
5602         } else {
5603           Inst.setOpcode(ARM::VMOVv16i8);
5604         }
5605       }
5606       if (cmode == 0xD) {
5607         if (op == 1) {
5608           Inst.setOpcode(ARM::VMVNv4i32);
5609         } else {
5610           Inst.setOpcode(ARM::VMOVv4i32);
5611         }
5612       }
5613       if (cmode == 0xC) {
5614         if (op == 1) {
5615           Inst.setOpcode(ARM::VMVNv4i32);
5616         } else {
5617           Inst.setOpcode(ARM::VMOVv4i32);
5618         }
5619       }
5620     }
5621     return DecodeNEONModImmInstruction(Inst, Insn, Address, Decoder);
5622   }
5623 
5624   if (!(imm & 0x20)) return MCDisassembler::Fail;
5625 
5626   if (!Check(S, DecodeQPRRegisterClass(Inst, Vd, Address, Decoder)))
5627     return MCDisassembler::Fail;
5628   if (!Check(S, DecodeQPRRegisterClass(Inst, Vm, Address, Decoder)))
5629     return MCDisassembler::Fail;
5630   Inst.addOperand(MCOperand::createImm(64 - imm));
5631 
5632   return S;
5633 }
5634 
5635 static DecodeStatus DecodeNEONComplexLane64Instruction(MCInst &Inst,
5636                                                        unsigned Insn,
5637                                                        uint64_t Address,
5638                                                        const void *Decoder) {
5639   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5640   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5641   unsigned Vn = (fieldFromInstruction(Insn, 16, 4) << 0);
5642   Vn |= (fieldFromInstruction(Insn, 7, 1) << 4);
5643   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5644   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5645   unsigned q = (fieldFromInstruction(Insn, 6, 1) << 0);
5646   unsigned rotate = (fieldFromInstruction(Insn, 20, 2) << 0);
5647 
5648   DecodeStatus S = MCDisassembler::Success;
5649 
5650   auto DestRegDecoder = q ? DecodeQPRRegisterClass : DecodeDPRRegisterClass;
5651 
5652   if (!Check(S, DestRegDecoder(Inst, Vd, Address, Decoder)))
5653     return MCDisassembler::Fail;
5654   if (!Check(S, DestRegDecoder(Inst, Vd, Address, Decoder)))
5655     return MCDisassembler::Fail;
5656   if (!Check(S, DestRegDecoder(Inst, Vn, Address, Decoder)))
5657     return MCDisassembler::Fail;
5658   if (!Check(S, DecodeDPRRegisterClass(Inst, Vm, Address, Decoder)))
5659     return MCDisassembler::Fail;
5660   // The lane index does not have any bits in the encoding, because it can only
5661   // be 0.
5662   Inst.addOperand(MCOperand::createImm(0));
5663   Inst.addOperand(MCOperand::createImm(rotate));
5664 
5665   return S;
5666 }
5667 
5668 static DecodeStatus DecodeLDR(MCInst &Inst, unsigned Val,
5669                                 uint64_t Address, const void *Decoder) {
5670   DecodeStatus S = MCDisassembler::Success;
5671 
5672   unsigned Rn = fieldFromInstruction(Val, 16, 4);
5673   unsigned Rt = fieldFromInstruction(Val, 12, 4);
5674   unsigned Rm = fieldFromInstruction(Val, 0, 4);
5675   Rm |= (fieldFromInstruction(Val, 23, 1) << 4);
5676   unsigned Cond = fieldFromInstruction(Val, 28, 4);
5677 
5678   if (fieldFromInstruction(Val, 8, 4) != 0 || Rn == Rt)
5679     S = MCDisassembler::SoftFail;
5680 
5681   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5682     return MCDisassembler::Fail;
5683   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
5684     return MCDisassembler::Fail;
5685   if (!Check(S, DecodeAddrMode7Operand(Inst, Rn, Address, Decoder)))
5686     return MCDisassembler::Fail;
5687   if (!Check(S, DecodePostIdxReg(Inst, Rm, Address, Decoder)))
5688     return MCDisassembler::Fail;
5689   if (!Check(S, DecodePredicateOperand(Inst, Cond, Address, Decoder)))
5690     return MCDisassembler::Fail;
5691 
5692   return S;
5693 }
5694 
5695 static DecodeStatus DecoderForMRRC2AndMCRR2(MCInst &Inst, unsigned Val,
5696                                             uint64_t Address, const void *Decoder) {
5697   DecodeStatus S = MCDisassembler::Success;
5698 
5699   unsigned CRm = fieldFromInstruction(Val, 0, 4);
5700   unsigned opc1 = fieldFromInstruction(Val, 4, 4);
5701   unsigned cop = fieldFromInstruction(Val, 8, 4);
5702   unsigned Rt = fieldFromInstruction(Val, 12, 4);
5703   unsigned Rt2 = fieldFromInstruction(Val, 16, 4);
5704 
5705   if ((cop & ~0x1) == 0xa)
5706     return MCDisassembler::Fail;
5707 
5708   if (Rt == Rt2)
5709     S = MCDisassembler::SoftFail;
5710 
5711   // We have to check if the instruction is MRRC2
5712   // or MCRR2 when constructing the operands for
5713   // Inst. Reason is because MRRC2 stores to two
5714   // registers so it's tablegen desc has has two
5715   // outputs whereas MCRR doesn't store to any
5716   // registers so all of it's operands are listed
5717   // as inputs, therefore the operand order for
5718   // MRRC2 needs to be [Rt, Rt2, cop, opc1, CRm]
5719   // and MCRR2 operand order is [cop, opc1, Rt, Rt2, CRm]
5720 
5721   if (Inst.getOpcode() == ARM::MRRC2) {
5722     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5723       return MCDisassembler::Fail;
5724     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5725       return MCDisassembler::Fail;
5726   }
5727   Inst.addOperand(MCOperand::createImm(cop));
5728   Inst.addOperand(MCOperand::createImm(opc1));
5729   if (Inst.getOpcode() == ARM::MCRR2) {
5730     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5731       return MCDisassembler::Fail;
5732     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5733       return MCDisassembler::Fail;
5734   }
5735   Inst.addOperand(MCOperand::createImm(CRm));
5736 
5737   return S;
5738 }
5739 
5740 static DecodeStatus DecodeForVMRSandVMSR(MCInst &Inst, unsigned Val,
5741                                          uint64_t Address,
5742                                          const void *Decoder) {
5743   const FeatureBitset &featureBits =
5744       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5745   DecodeStatus S = MCDisassembler::Success;
5746 
5747   // Add explicit operand for the destination sysreg, for cases where
5748   // we have to model it for code generation purposes.
5749   switch (Inst.getOpcode()) {
5750   case ARM::VMSR_FPSCR_NZCVQC:
5751     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
5752     break;
5753   case ARM::VMSR_P0:
5754     Inst.addOperand(MCOperand::createReg(ARM::VPR));
5755     break;
5756   }
5757 
5758   if (Inst.getOpcode() != ARM::FMSTAT) {
5759     unsigned Rt = fieldFromInstruction(Val, 12, 4);
5760 
5761     if (featureBits[ARM::ModeThumb] && !featureBits[ARM::HasV8Ops]) {
5762       if (Rt == 13 || Rt == 15)
5763         S = MCDisassembler::SoftFail;
5764       Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder));
5765     } else
5766       Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder));
5767   }
5768 
5769   // Add explicit operand for the source sysreg, similarly to above.
5770   switch (Inst.getOpcode()) {
5771   case ARM::VMRS_FPSCR_NZCVQC:
5772     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
5773     break;
5774   case ARM::VMRS_P0:
5775     Inst.addOperand(MCOperand::createReg(ARM::VPR));
5776     break;
5777   }
5778 
5779   if (featureBits[ARM::ModeThumb]) {
5780     Inst.addOperand(MCOperand::createImm(ARMCC::AL));
5781     Inst.addOperand(MCOperand::createReg(0));
5782   } else {
5783     unsigned pred = fieldFromInstruction(Val, 28, 4);
5784     if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5785       return MCDisassembler::Fail;
5786   }
5787 
5788   return S;
5789 }
5790 
5791 template <bool isSigned, bool isNeg, int size>
5792 static DecodeStatus DecodeBFLabelOperand(MCInst &Inst, unsigned Val,
5793                                          uint64_t Address,
5794                                          const void *Decoder) {
5795   DecodeStatus S = MCDisassembler::Success;
5796   if (Val == 0)
5797     S = MCDisassembler::SoftFail;
5798 
5799   uint64_t DecVal;
5800   if (isSigned)
5801     DecVal = SignExtend32<size + 1>(Val << 1);
5802   else
5803     DecVal = (Val << 1);
5804 
5805   if (!tryAddingSymbolicOperand(Address, Address + DecVal + 4, true, 4, Inst,
5806                                 Decoder))
5807     Inst.addOperand(MCOperand::createImm(isNeg ? -DecVal : DecVal));
5808   return S;
5809 }
5810 
5811 static DecodeStatus DecodeBFAfterTargetOperand(MCInst &Inst, unsigned Val,
5812                                                uint64_t Address,
5813                                                const void *Decoder) {
5814 
5815   uint64_t LocImm = Inst.getOperand(0).getImm();
5816   Val = LocImm + (2 << Val);
5817   if (!tryAddingSymbolicOperand(Address, Address + Val + 4, true, 4, Inst,
5818                                 Decoder))
5819     Inst.addOperand(MCOperand::createImm(Val));
5820   return MCDisassembler::Success;
5821 }
5822 
5823 static DecodeStatus DecodePredNoALOperand(MCInst &Inst, unsigned Val,
5824                                           uint64_t Address,
5825                                           const void *Decoder) {
5826   if (Val >= ARMCC::AL)  // also exclude the non-condition NV
5827     return MCDisassembler::Fail;
5828   Inst.addOperand(MCOperand::createImm(Val));
5829   return MCDisassembler::Success;
5830 }
5831 
5832 static DecodeStatus DecodeLOLoop(MCInst &Inst, unsigned Insn, uint64_t Address,
5833                                  const void *Decoder) {
5834   DecodeStatus S = MCDisassembler::Success;
5835 
5836   unsigned Imm = fieldFromInstruction(Insn, 11, 1) |
5837                  fieldFromInstruction(Insn, 1, 10) << 1;
5838   switch (Inst.getOpcode()) {
5839   case ARM::t2LEUpdate:
5840     Inst.addOperand(MCOperand::createReg(ARM::LR));
5841     Inst.addOperand(MCOperand::createReg(ARM::LR));
5842     LLVM_FALLTHROUGH;
5843   case ARM::t2LE:
5844     if (!Check(S, DecodeBFLabelOperand<false, true, 11>(Inst, Imm, Address,
5845                                                         Decoder)))
5846       return MCDisassembler::Fail;
5847     break;
5848   case ARM::t2WLS:
5849     Inst.addOperand(MCOperand::createReg(ARM::LR));
5850     if (!Check(S,
5851                DecoderGPRRegisterClass(Inst, fieldFromInstruction(Insn, 16, 4),
5852                                        Address, Decoder)) ||
5853         !Check(S, DecodeBFLabelOperand<false, false, 11>(Inst, Imm, Address,
5854                                                          Decoder)))
5855       return MCDisassembler::Fail;
5856     break;
5857   case ARM::t2DLS:
5858     unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5859     if (Rn == 0xF) {
5860       return MCDisassembler::Fail;
5861     } else {
5862       Inst.addOperand(MCOperand::createReg(ARM::LR));
5863       if (!Check(S, DecoderGPRRegisterClass(Inst,
5864                                             fieldFromInstruction(Insn, 16, 4),
5865                                             Address, Decoder)))
5866         return MCDisassembler::Fail;
5867     }
5868     break;
5869   }
5870   return S;
5871 }
5872 
5873 static DecodeStatus DecodeLongShiftOperand(MCInst &Inst, unsigned Val,
5874                                            uint64_t Address,
5875                                            const void *Decoder) {
5876   DecodeStatus S = MCDisassembler::Success;
5877 
5878   if (Val == 0)
5879     Val = 32;
5880 
5881   Inst.addOperand(MCOperand::createImm(Val));
5882 
5883   return S;
5884 }
5885 
5886 static DecodeStatus DecodetGPROddRegisterClass(MCInst &Inst, unsigned RegNo,
5887                                    uint64_t Address, const void *Decoder) {
5888   if ((RegNo) + 1 > 11)
5889     return MCDisassembler::Fail;
5890 
5891   unsigned Register = GPRDecoderTable[(RegNo) + 1];
5892   Inst.addOperand(MCOperand::createReg(Register));
5893   return MCDisassembler::Success;
5894 }
5895 
5896 static DecodeStatus DecodetGPREvenRegisterClass(MCInst &Inst, unsigned RegNo,
5897                                    uint64_t Address, const void *Decoder) {
5898   if ((RegNo) > 14)
5899     return MCDisassembler::Fail;
5900 
5901   unsigned Register = GPRDecoderTable[(RegNo)];
5902   Inst.addOperand(MCOperand::createReg(Register));
5903   return MCDisassembler::Success;
5904 }
5905 
5906 static DecodeStatus DecodeVSCCLRM(MCInst &Inst, unsigned Insn, uint64_t Address,
5907                                   const void *Decoder) {
5908   DecodeStatus S = MCDisassembler::Success;
5909 
5910   Inst.addOperand(MCOperand::createImm(ARMCC::AL));
5911   Inst.addOperand(MCOperand::createReg(0));
5912   if (Inst.getOpcode() == ARM::VSCCLRMD) {
5913     unsigned reglist = (fieldFromInstruction(Insn, 1, 7) << 1) |
5914                        (fieldFromInstruction(Insn, 12, 4) << 8) |
5915                        (fieldFromInstruction(Insn, 22, 1) << 12);
5916     if (!Check(S, DecodeDPRRegListOperand(Inst, reglist, Address, Decoder))) {
5917       return MCDisassembler::Fail;
5918     }
5919   } else {
5920     unsigned reglist = fieldFromInstruction(Insn, 0, 8) |
5921                        (fieldFromInstruction(Insn, 22, 1) << 8) |
5922                        (fieldFromInstruction(Insn, 12, 4) << 9);
5923     if (!Check(S, DecodeSPRRegListOperand(Inst, reglist, Address, Decoder))) {
5924       return MCDisassembler::Fail;
5925     }
5926   }
5927   Inst.addOperand(MCOperand::createReg(ARM::VPR));
5928 
5929   return S;
5930 }
5931 
5932 static DecodeStatus DecodeMQPRRegisterClass(MCInst &Inst, unsigned RegNo,
5933                               uint64_t Address,
5934                               const void *Decoder) {
5935   if (RegNo > 7)
5936     return MCDisassembler::Fail;
5937 
5938   unsigned Register = QPRDecoderTable[RegNo];
5939   Inst.addOperand(MCOperand::createReg(Register));
5940   return MCDisassembler::Success;
5941 }
5942 
5943 static DecodeStatus DecodeVPTMaskOperand(MCInst &Inst, unsigned Val,
5944                                          uint64_t Address,
5945                                          const void *Decoder) {
5946   DecodeStatus S = MCDisassembler::Success;
5947 
5948   // Parse VPT mask and encode it in the MCInst as an immediate with the same
5949   // format as the it_mask.  That is, from the second 'e|t' encode 'e' as 1 and
5950   // 't' as 0 and finish with a 1.
5951   unsigned Imm = 0;
5952   // We always start with a 't'.
5953   unsigned CurBit = 0;
5954   for (int i = 3; i >= 0; --i) {
5955     // If the bit we are looking at is not the same as last one, invert the
5956     // CurBit, if it is the same leave it as is.
5957     CurBit ^= (Val >> i) & 1U;
5958 
5959     // Encode the CurBit at the right place in the immediate.
5960     Imm |= (CurBit << i);
5961 
5962     // If we are done, finish the encoding with a 1.
5963     if ((Val & ~(~0U << i)) == 0) {
5964       Imm |= 1U << i;
5965       break;
5966     }
5967   }
5968 
5969   Inst.addOperand(MCOperand::createImm(Imm));
5970 
5971   return S;
5972 }
5973 
5974 static DecodeStatus DecodeVpredROperand(MCInst &Inst, unsigned RegNo,
5975                                         uint64_t Address, const void *Decoder) {
5976   // The vpred_r operand type includes an MQPR register field derived
5977   // from the encoding. But we don't actually want to add an operand
5978   // to the MCInst at this stage, because AddThumbPredicate will do it
5979   // later, and will infer the register number from the TIED_TO
5980   // constraint. So this is a deliberately empty decoder method that
5981   // will inhibit the auto-generated disassembly code from adding an
5982   // operand at all.
5983   return MCDisassembler::Success;
5984 }
5985 
5986 static DecodeStatus DecodeRestrictedIPredicateOperand(MCInst &Inst,
5987                                                       unsigned Val,
5988                                                       uint64_t Address,
5989                                                       const void *Decoder) {
5990   Inst.addOperand(MCOperand::createImm((Val & 0x1) == 0 ? ARMCC::EQ : ARMCC::NE));
5991   return MCDisassembler::Success;
5992 }
5993 
5994 static DecodeStatus DecodeRestrictedSPredicateOperand(MCInst &Inst,
5995                                                       unsigned Val,
5996                                                       uint64_t Address,
5997                                                       const void *Decoder) {
5998   unsigned Code;
5999   switch (Val & 0x3) {
6000   case 0:
6001     Code = ARMCC::GE;
6002     break;
6003   case 1:
6004     Code = ARMCC::LT;
6005     break;
6006   case 2:
6007     Code = ARMCC::GT;
6008     break;
6009   case 3:
6010     Code = ARMCC::LE;
6011     break;
6012   }
6013   Inst.addOperand(MCOperand::createImm(Code));
6014   return MCDisassembler::Success;
6015 }
6016 
6017 static DecodeStatus DecodeRestrictedUPredicateOperand(MCInst &Inst,
6018                                                       unsigned Val,
6019                                                       uint64_t Address,
6020                                                       const void *Decoder) {
6021   Inst.addOperand(MCOperand::createImm((Val & 0x1) == 0 ? ARMCC::HS : ARMCC::HI));
6022   return MCDisassembler::Success;
6023 }
6024 
6025 static DecodeStatus DecodeRestrictedFPPredicateOperand(MCInst &Inst, unsigned Val,
6026                                                      uint64_t Address,
6027                                                      const void *Decoder) {
6028   unsigned Code;
6029   switch (Val) {
6030   default:
6031     return MCDisassembler::Fail;
6032   case 0:
6033     Code = ARMCC::EQ;
6034     break;
6035   case 1:
6036     Code = ARMCC::NE;
6037     break;
6038   case 4:
6039     Code = ARMCC::GE;
6040     break;
6041   case 5:
6042     Code = ARMCC::LT;
6043     break;
6044   case 6:
6045     Code = ARMCC::GT;
6046     break;
6047   case 7:
6048     Code = ARMCC::LE;
6049     break;
6050   }
6051 
6052   Inst.addOperand(MCOperand::createImm(Code));
6053   return MCDisassembler::Success;
6054 }
6055 
6056 static DecodeStatus DecodeVCVTImmOperand(MCInst &Inst, unsigned Val,
6057                                          uint64_t Address, const void *Decoder) {
6058   DecodeStatus S = MCDisassembler::Success;
6059 
6060   unsigned DecodedVal = 64 - Val;
6061 
6062   switch (Inst.getOpcode()) {
6063   case ARM::MVE_VCVTf16s16_fix:
6064   case ARM::MVE_VCVTs16f16_fix:
6065   case ARM::MVE_VCVTf16u16_fix:
6066   case ARM::MVE_VCVTu16f16_fix:
6067     if (DecodedVal > 16)
6068       return MCDisassembler::Fail;
6069     break;
6070   case ARM::MVE_VCVTf32s32_fix:
6071   case ARM::MVE_VCVTs32f32_fix:
6072   case ARM::MVE_VCVTf32u32_fix:
6073   case ARM::MVE_VCVTu32f32_fix:
6074     if (DecodedVal > 32)
6075       return MCDisassembler::Fail;
6076     break;
6077   }
6078 
6079   Inst.addOperand(MCOperand::createImm(64 - Val));
6080 
6081   return S;
6082 }
6083 
6084 static unsigned FixedRegForVSTRVLDR_SYSREG(unsigned Opcode) {
6085   switch (Opcode) {
6086   case ARM::VSTR_P0_off:
6087   case ARM::VSTR_P0_pre:
6088   case ARM::VSTR_P0_post:
6089   case ARM::VLDR_P0_off:
6090   case ARM::VLDR_P0_pre:
6091   case ARM::VLDR_P0_post:
6092     return ARM::P0;
6093   default:
6094     return 0;
6095   }
6096 }
6097 
6098 template<bool Writeback>
6099 static DecodeStatus DecodeVSTRVLDR_SYSREG(MCInst &Inst, unsigned Val,
6100                                           uint64_t Address,
6101                                           const void *Decoder) {
6102   switch (Inst.getOpcode()) {
6103   case ARM::VSTR_FPSCR_pre:
6104   case ARM::VSTR_FPSCR_NZCVQC_pre:
6105   case ARM::VLDR_FPSCR_pre:
6106   case ARM::VLDR_FPSCR_NZCVQC_pre:
6107   case ARM::VSTR_FPSCR_off:
6108   case ARM::VSTR_FPSCR_NZCVQC_off:
6109   case ARM::VLDR_FPSCR_off:
6110   case ARM::VLDR_FPSCR_NZCVQC_off:
6111   case ARM::VSTR_FPSCR_post:
6112   case ARM::VSTR_FPSCR_NZCVQC_post:
6113   case ARM::VLDR_FPSCR_post:
6114   case ARM::VLDR_FPSCR_NZCVQC_post:
6115     const FeatureBitset &featureBits =
6116         ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
6117 
6118     if (!featureBits[ARM::HasMVEIntegerOps] && !featureBits[ARM::FeatureVFP2])
6119       return MCDisassembler::Fail;
6120   }
6121 
6122   DecodeStatus S = MCDisassembler::Success;
6123   if (unsigned Sysreg = FixedRegForVSTRVLDR_SYSREG(Inst.getOpcode()))
6124     Inst.addOperand(MCOperand::createReg(Sysreg));
6125   unsigned Rn = fieldFromInstruction(Val, 16, 4);
6126   unsigned addr = fieldFromInstruction(Val, 0, 7) |
6127                   (fieldFromInstruction(Val, 23, 1) << 7) | (Rn << 8);
6128 
6129   if (Writeback) {
6130     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
6131       return MCDisassembler::Fail;
6132   }
6133   if (!Check(S, DecodeT2AddrModeImm7s4(Inst, addr, Address, Decoder)))
6134     return MCDisassembler::Fail;
6135 
6136   Inst.addOperand(MCOperand::createImm(ARMCC::AL));
6137   Inst.addOperand(MCOperand::createReg(0));
6138 
6139   return S;
6140 }
6141 
6142 template<unsigned MinLog, unsigned MaxLog>
6143 static DecodeStatus DecodePowerTwoOperand(MCInst &Inst, unsigned Val,
6144                                           uint64_t Address,
6145                                           const void *Decoder) {
6146   DecodeStatus S = MCDisassembler::Success;
6147 
6148   if (Val < MinLog || Val > MaxLog)
6149     return MCDisassembler::Fail;
6150 
6151   Inst.addOperand(MCOperand::createImm(1LL << Val));
6152   return S;
6153 }
6154 
6155 template <int shift>
6156 static DecodeStatus DecodeExpandedImmOperand(MCInst &Inst, unsigned Val,
6157                                              uint64_t Address,
6158                                              const void *Decoder) {
6159     Val <<= shift;
6160 
6161     Inst.addOperand(MCOperand::createImm(Val));
6162     return MCDisassembler::Success;
6163 }
6164 
6165 template<unsigned start>
6166 static DecodeStatus DecodeMVEPairVectorIndexOperand(MCInst &Inst, unsigned Val,
6167                                                     uint64_t Address,
6168                                                     const void *Decoder) {
6169   DecodeStatus S = MCDisassembler::Success;
6170 
6171   Inst.addOperand(MCOperand::createImm(start + Val));
6172 
6173   return S;
6174 }
6175 
6176 static DecodeStatus DecodeMVEVMOVQtoDReg(MCInst &Inst, unsigned Insn,
6177                                          uint64_t Address, const void *Decoder) {
6178   DecodeStatus S = MCDisassembler::Success;
6179   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
6180   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
6181   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
6182                  fieldFromInstruction(Insn, 13, 3));
6183   unsigned index = fieldFromInstruction(Insn, 4, 1);
6184 
6185   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
6186     return MCDisassembler::Fail;
6187   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2, Address, Decoder)))
6188     return MCDisassembler::Fail;
6189   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6190     return MCDisassembler::Fail;
6191   if (!Check(S, DecodeMVEPairVectorIndexOperand<2>(Inst, index, Address, Decoder)))
6192     return MCDisassembler::Fail;
6193   if (!Check(S, DecodeMVEPairVectorIndexOperand<0>(Inst, index, Address, Decoder)))
6194     return MCDisassembler::Fail;
6195 
6196   return S;
6197 }
6198 
6199 static DecodeStatus DecodeMVEVMOVDRegtoQ(MCInst &Inst, unsigned Insn,
6200                                          uint64_t Address, const void *Decoder) {
6201   DecodeStatus S = MCDisassembler::Success;
6202   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
6203   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
6204   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
6205                  fieldFromInstruction(Insn, 13, 3));
6206   unsigned index = fieldFromInstruction(Insn, 4, 1);
6207 
6208   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6209     return MCDisassembler::Fail;
6210   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6211     return MCDisassembler::Fail;
6212   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
6213     return MCDisassembler::Fail;
6214   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2, Address, Decoder)))
6215     return MCDisassembler::Fail;
6216   if (!Check(S, DecodeMVEPairVectorIndexOperand<2>(Inst, index, Address, Decoder)))
6217     return MCDisassembler::Fail;
6218   if (!Check(S, DecodeMVEPairVectorIndexOperand<0>(Inst, index, Address, Decoder)))
6219     return MCDisassembler::Fail;
6220 
6221   return S;
6222 }
6223 
6224 static DecodeStatus DecodeMVEOverlappingLongShift(
6225   MCInst &Inst, unsigned Insn, uint64_t Address, const void *Decoder) {
6226   DecodeStatus S = MCDisassembler::Success;
6227 
6228   unsigned RdaLo = fieldFromInstruction(Insn, 17, 3) << 1;
6229   unsigned RdaHi = fieldFromInstruction(Insn, 9, 3) << 1;
6230   unsigned Rm = fieldFromInstruction(Insn, 12, 4);
6231 
6232   if (RdaHi == 14) {
6233     // This value of RdaHi (really indicating pc, because RdaHi has to
6234     // be an odd-numbered register, so the low bit will be set by the
6235     // decode function below) indicates that we must decode as SQRSHR
6236     // or UQRSHL, which both have a single Rda register field with all
6237     // four bits.
6238     unsigned Rda = fieldFromInstruction(Insn, 16, 4);
6239 
6240     switch (Inst.getOpcode()) {
6241       case ARM::MVE_ASRLr:
6242       case ARM::MVE_SQRSHRL:
6243         Inst.setOpcode(ARM::MVE_SQRSHR);
6244         break;
6245       case ARM::MVE_LSLLr:
6246       case ARM::MVE_UQRSHLL:
6247         Inst.setOpcode(ARM::MVE_UQRSHL);
6248         break;
6249       default:
6250         llvm_unreachable("Unexpected starting opcode!");
6251     }
6252 
6253     // Rda as output parameter
6254     if (!Check(S, DecoderGPRRegisterClass(Inst, Rda, Address, Decoder)))
6255       return MCDisassembler::Fail;
6256 
6257     // Rda again as input parameter
6258     if (!Check(S, DecoderGPRRegisterClass(Inst, Rda, Address, Decoder)))
6259       return MCDisassembler::Fail;
6260 
6261     // Rm, the amount to shift by
6262     if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
6263       return MCDisassembler::Fail;
6264 
6265     return S;
6266   }
6267 
6268   // Otherwise, we decode as whichever opcode our caller has already
6269   // put into Inst. Those all look the same:
6270 
6271   // RdaLo,RdaHi as output parameters
6272   if (!Check(S, DecodetGPREvenRegisterClass(Inst, RdaLo, Address, Decoder)))
6273     return MCDisassembler::Fail;
6274   if (!Check(S, DecodetGPROddRegisterClass(Inst, RdaHi, Address, Decoder)))
6275     return MCDisassembler::Fail;
6276 
6277   // RdaLo,RdaHi again as input parameters
6278   if (!Check(S, DecodetGPREvenRegisterClass(Inst, RdaLo, Address, Decoder)))
6279     return MCDisassembler::Fail;
6280   if (!Check(S, DecodetGPROddRegisterClass(Inst, RdaHi, Address, Decoder)))
6281     return MCDisassembler::Fail;
6282 
6283   // Rm, the amount to shift by
6284   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
6285     return MCDisassembler::Fail;
6286 
6287   return S;
6288 }
6289 
6290 static DecodeStatus DecodeMVEVCVTt1fp(MCInst &Inst, unsigned Insn, uint64_t Address,
6291                                       const void *Decoder) {
6292   DecodeStatus S = MCDisassembler::Success;
6293   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
6294                  fieldFromInstruction(Insn, 13, 3));
6295   unsigned Qm = ((fieldFromInstruction(Insn, 5, 1) << 3) |
6296                  fieldFromInstruction(Insn, 1, 3));
6297   unsigned imm6 = fieldFromInstruction(Insn, 16, 6);
6298 
6299   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6300     return MCDisassembler::Fail;
6301   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
6302     return MCDisassembler::Fail;
6303   if (!Check(S, DecodeVCVTImmOperand(Inst, imm6, Address, Decoder)))
6304     return MCDisassembler::Fail;
6305 
6306   return S;
6307 }
6308 
6309 template<bool scalar, OperandDecoder predicate_decoder>
6310 static DecodeStatus DecodeMVEVCMP(MCInst &Inst, unsigned Insn, uint64_t Address,
6311                                   const void *Decoder) {
6312   DecodeStatus S = MCDisassembler::Success;
6313   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6314   unsigned Qn = fieldFromInstruction(Insn, 17, 3);
6315   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qn, Address, Decoder)))
6316     return MCDisassembler::Fail;
6317 
6318   unsigned fc;
6319 
6320   if (scalar) {
6321     fc = fieldFromInstruction(Insn, 12, 1) << 2 |
6322          fieldFromInstruction(Insn, 7, 1) |
6323          fieldFromInstruction(Insn, 5, 1) << 1;
6324     unsigned Rm = fieldFromInstruction(Insn, 0, 4);
6325     if (!Check(S, DecodeGPRwithZRRegisterClass(Inst, Rm, Address, Decoder)))
6326       return MCDisassembler::Fail;
6327   } else {
6328     fc = fieldFromInstruction(Insn, 12, 1) << 2 |
6329          fieldFromInstruction(Insn, 7, 1) |
6330          fieldFromInstruction(Insn, 0, 1) << 1;
6331     unsigned Qm = fieldFromInstruction(Insn, 5, 1) << 4 |
6332                   fieldFromInstruction(Insn, 1, 3);
6333     if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
6334       return MCDisassembler::Fail;
6335   }
6336 
6337   if (!Check(S, predicate_decoder(Inst, fc, Address, Decoder)))
6338     return MCDisassembler::Fail;
6339 
6340   Inst.addOperand(MCOperand::createImm(ARMVCC::None));
6341   Inst.addOperand(MCOperand::createReg(0));
6342   Inst.addOperand(MCOperand::createImm(0));
6343 
6344   return S;
6345 }
6346 
6347 static DecodeStatus DecodeMveVCTP(MCInst &Inst, unsigned Insn, uint64_t Address,
6348                                   const void *Decoder) {
6349   DecodeStatus S = MCDisassembler::Success;
6350   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6351   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
6352   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
6353     return MCDisassembler::Fail;
6354   return S;
6355 }
6356