xref: /llvm-project/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp (revision 02449f9c3cf59836335d7e8c6ca76c84c5d9880c)
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 DecodeGPRwithZRnospRegisterClass(
198     MCInst &Inst, unsigned RegNo, uint64_t Address, const void *Decoder);
199 static DecodeStatus DecodetGPRRegisterClass(MCInst &Inst, unsigned RegNo,
200                                    uint64_t Address, const void *Decoder);
201 static DecodeStatus DecodetcGPRRegisterClass(MCInst &Inst, unsigned RegNo,
202                                    uint64_t Address, const void *Decoder);
203 static DecodeStatus DecoderGPRRegisterClass(MCInst &Inst, unsigned RegNo,
204                                    uint64_t Address, const void *Decoder);
205 static DecodeStatus DecodeGPRPairRegisterClass(MCInst &Inst, unsigned RegNo,
206                                    uint64_t Address, const void *Decoder);
207 static DecodeStatus DecodeHPRRegisterClass(MCInst &Inst, unsigned RegNo,
208                                    uint64_t Address, const void *Decoder);
209 static DecodeStatus DecodeSPRRegisterClass(MCInst &Inst, unsigned RegNo,
210                                    uint64_t Address, const void *Decoder);
211 static DecodeStatus DecodeDPRRegisterClass(MCInst &Inst, unsigned RegNo,
212                                    uint64_t Address, const void *Decoder);
213 static DecodeStatus DecodeDPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
214                                    uint64_t Address, const void *Decoder);
215 static DecodeStatus DecodeSPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
216                                    uint64_t Address, const void *Decoder);
217 static DecodeStatus DecodeDPR_VFP2RegisterClass(MCInst &Inst,
218                                                 unsigned RegNo,
219                                                 uint64_t Address,
220                                                 const void *Decoder);
221 static DecodeStatus DecodeQPRRegisterClass(MCInst &Inst, unsigned RegNo,
222                                    uint64_t Address, const void *Decoder);
223 static DecodeStatus DecodeMQPRRegisterClass(MCInst &Inst, unsigned RegNo,
224                                    uint64_t Address, const void *Decoder);
225 static DecodeStatus DecodeQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
226                                    uint64_t Address, const void *Decoder);
227 static DecodeStatus DecodeQQQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
228                                    uint64_t Address, const void *Decoder);
229 static DecodeStatus DecodeDPairRegisterClass(MCInst &Inst, unsigned RegNo,
230                                    uint64_t Address, const void *Decoder);
231 static DecodeStatus DecodeDPairSpacedRegisterClass(MCInst &Inst,
232                                unsigned RegNo, uint64_t Address,
233                                const void *Decoder);
234 
235 static DecodeStatus DecodePredicateOperand(MCInst &Inst, unsigned Val,
236                                uint64_t Address, const void *Decoder);
237 static DecodeStatus DecodeCCOutOperand(MCInst &Inst, unsigned Val,
238                                uint64_t Address, const void *Decoder);
239 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Val,
240                                uint64_t Address, const void *Decoder);
241 static DecodeStatus DecodeSPRRegListOperand(MCInst &Inst, unsigned Val,
242                                uint64_t Address, const void *Decoder);
243 static DecodeStatus DecodeDPRRegListOperand(MCInst &Inst, unsigned Val,
244                                uint64_t Address, const void *Decoder);
245 
246 static DecodeStatus DecodeBitfieldMaskOperand(MCInst &Inst, unsigned Insn,
247                                uint64_t Address, const void *Decoder);
248 static DecodeStatus DecodeCopMemInstruction(MCInst &Inst, unsigned Insn,
249                                uint64_t Address, const void *Decoder);
250 static DecodeStatus DecodeAddrMode2IdxInstruction(MCInst &Inst,
251                                                   unsigned Insn,
252                                                   uint64_t Address,
253                                                   const void *Decoder);
254 static DecodeStatus DecodeSORegMemOperand(MCInst &Inst, unsigned Insn,
255                                uint64_t Address, const void *Decoder);
256 static DecodeStatus DecodeAddrMode3Instruction(MCInst &Inst,unsigned Insn,
257                                uint64_t Address, const void *Decoder);
258 static DecodeStatus DecodeSORegImmOperand(MCInst &Inst, unsigned Insn,
259                                uint64_t Address, const void *Decoder);
260 static DecodeStatus DecodeSORegRegOperand(MCInst &Inst, unsigned Insn,
261                                uint64_t Address, const void *Decoder);
262 
263 static DecodeStatus DecodeMemMultipleWritebackInstruction(MCInst & Inst,
264                                                   unsigned Insn,
265                                                   uint64_t Adddress,
266                                                   const void *Decoder);
267 static DecodeStatus DecodeT2MOVTWInstruction(MCInst &Inst, unsigned Insn,
268                                uint64_t Address, const void *Decoder);
269 static DecodeStatus DecodeArmMOVTWInstruction(MCInst &Inst, unsigned Insn,
270                                uint64_t Address, const void *Decoder);
271 static DecodeStatus DecodeSMLAInstruction(MCInst &Inst, unsigned Insn,
272                                uint64_t Address, const void *Decoder);
273 static DecodeStatus DecodeHINTInstruction(MCInst &Inst, unsigned Insn,
274                                uint64_t Address, const void *Decoder);
275 static DecodeStatus DecodeCPSInstruction(MCInst &Inst, unsigned Insn,
276                                uint64_t Address, const void *Decoder);
277 static DecodeStatus DecodeTSTInstruction(MCInst &Inst, unsigned Insn,
278                                uint64_t Address, const void *Decoder);
279 static DecodeStatus DecodeSETPANInstruction(MCInst &Inst, unsigned Insn,
280                                uint64_t Address, const void *Decoder);
281 static DecodeStatus DecodeT2CPSInstruction(MCInst &Inst, unsigned Insn,
282                                uint64_t Address, const void *Decoder);
283 static DecodeStatus DecodeAddrModeImm12Operand(MCInst &Inst, unsigned Val,
284                                uint64_t Address, const void *Decoder);
285 static DecodeStatus DecodeAddrMode5Operand(MCInst &Inst, unsigned Val,
286                                uint64_t Address, const void *Decoder);
287 static DecodeStatus DecodeAddrMode5FP16Operand(MCInst &Inst, unsigned Val,
288                                uint64_t Address, const void *Decoder);
289 static DecodeStatus DecodeAddrMode7Operand(MCInst &Inst, unsigned Val,
290                                uint64_t Address, const void *Decoder);
291 static DecodeStatus DecodeT2BInstruction(MCInst &Inst, unsigned Insn,
292                                uint64_t Address, const void *Decoder);
293 static DecodeStatus DecodeBranchImmInstruction(MCInst &Inst,unsigned Insn,
294                                uint64_t Address, const void *Decoder);
295 static DecodeStatus DecodeAddrMode6Operand(MCInst &Inst, unsigned Val,
296                                uint64_t Address, const void *Decoder);
297 static DecodeStatus DecodeVLDST1Instruction(MCInst &Inst, unsigned Val,
298                                uint64_t Address, const void *Decoder);
299 static DecodeStatus DecodeVLDST2Instruction(MCInst &Inst, unsigned Val,
300                                uint64_t Address, const void *Decoder);
301 static DecodeStatus DecodeVLDST3Instruction(MCInst &Inst, unsigned Val,
302                                uint64_t Address, const void *Decoder);
303 static DecodeStatus DecodeVLDST4Instruction(MCInst &Inst, unsigned Val,
304                                uint64_t Address, const void *Decoder);
305 static DecodeStatus DecodeVLDInstruction(MCInst &Inst, unsigned Val,
306                                uint64_t Address, const void *Decoder);
307 static DecodeStatus DecodeVSTInstruction(MCInst &Inst, unsigned Val,
308                                uint64_t Address, const void *Decoder);
309 static DecodeStatus DecodeVLD1DupInstruction(MCInst &Inst, unsigned Val,
310                                uint64_t Address, const void *Decoder);
311 static DecodeStatus DecodeVLD2DupInstruction(MCInst &Inst, unsigned Val,
312                                uint64_t Address, const void *Decoder);
313 static DecodeStatus DecodeVLD3DupInstruction(MCInst &Inst, unsigned Val,
314                                uint64_t Address, const void *Decoder);
315 static DecodeStatus DecodeVLD4DupInstruction(MCInst &Inst, unsigned Val,
316                                uint64_t Address, const void *Decoder);
317 static DecodeStatus DecodeNEONModImmInstruction(MCInst &Inst,unsigned Val,
318                                uint64_t Address, const void *Decoder);
319 static DecodeStatus DecodeMVEModImmInstruction(MCInst &Inst,unsigned Val,
320                                uint64_t Address, const void *Decoder);
321 static DecodeStatus DecodeMVEVADCInstruction(MCInst &Inst, unsigned Insn,
322                                uint64_t Address, const void *Decoder);
323 static DecodeStatus DecodeVSHLMaxInstruction(MCInst &Inst, unsigned Val,
324                                uint64_t Address, const void *Decoder);
325 static DecodeStatus DecodeShiftRight8Imm(MCInst &Inst, unsigned Val,
326                                uint64_t Address, const void *Decoder);
327 static DecodeStatus DecodeShiftRight16Imm(MCInst &Inst, unsigned Val,
328                                uint64_t Address, const void *Decoder);
329 static DecodeStatus DecodeShiftRight32Imm(MCInst &Inst, unsigned Val,
330                                uint64_t Address, const void *Decoder);
331 static DecodeStatus DecodeShiftRight64Imm(MCInst &Inst, unsigned Val,
332                                uint64_t Address, const void *Decoder);
333 static DecodeStatus DecodeTBLInstruction(MCInst &Inst, unsigned Insn,
334                                uint64_t Address, const void *Decoder);
335 static DecodeStatus DecodePostIdxReg(MCInst &Inst, unsigned Insn,
336                                uint64_t Address, const void *Decoder);
337 static DecodeStatus DecodeMveAddrModeRQ(MCInst &Inst, unsigned Insn,
338                                uint64_t Address, const void *Decoder);
339 template<int shift>
340 static DecodeStatus DecodeMveAddrModeQ(MCInst &Inst, unsigned Insn,
341                                uint64_t Address, const void *Decoder);
342 static DecodeStatus DecodeCoprocessor(MCInst &Inst, unsigned Insn,
343                                uint64_t Address, const void *Decoder);
344 static DecodeStatus DecodeMemBarrierOption(MCInst &Inst, unsigned Insn,
345                                uint64_t Address, const void *Decoder);
346 static DecodeStatus DecodeInstSyncBarrierOption(MCInst &Inst, unsigned Insn,
347                                uint64_t Address, const void *Decoder);
348 static DecodeStatus DecodeMSRMask(MCInst &Inst, unsigned Insn,
349                                uint64_t Address, const void *Decoder);
350 static DecodeStatus DecodeBankedReg(MCInst &Inst, unsigned Insn,
351                                uint64_t Address, const void *Decoder);
352 static DecodeStatus DecodeDoubleRegLoad(MCInst &Inst, unsigned Insn,
353                                uint64_t Address, const void *Decoder);
354 static DecodeStatus DecodeDoubleRegStore(MCInst &Inst, unsigned Insn,
355                                uint64_t Address, const void *Decoder);
356 static DecodeStatus DecodeLDRPreImm(MCInst &Inst, unsigned Insn,
357                                uint64_t Address, const void *Decoder);
358 static DecodeStatus DecodeLDRPreReg(MCInst &Inst, unsigned Insn,
359                                uint64_t Address, const void *Decoder);
360 static DecodeStatus DecodeSTRPreImm(MCInst &Inst, unsigned Insn,
361                                uint64_t Address, const void *Decoder);
362 static DecodeStatus DecodeSTRPreReg(MCInst &Inst, unsigned Insn,
363                                uint64_t Address, const void *Decoder);
364 static DecodeStatus DecodeVLD1LN(MCInst &Inst, unsigned Insn,
365                                uint64_t Address, const void *Decoder);
366 static DecodeStatus DecodeVLD2LN(MCInst &Inst, unsigned Insn,
367                                uint64_t Address, const void *Decoder);
368 static DecodeStatus DecodeVLD3LN(MCInst &Inst, unsigned Insn,
369                                uint64_t Address, const void *Decoder);
370 static DecodeStatus DecodeVLD4LN(MCInst &Inst, unsigned Insn,
371                                uint64_t Address, const void *Decoder);
372 static DecodeStatus DecodeVST1LN(MCInst &Inst, unsigned Insn,
373                                uint64_t Address, const void *Decoder);
374 static DecodeStatus DecodeVST2LN(MCInst &Inst, unsigned Insn,
375                                uint64_t Address, const void *Decoder);
376 static DecodeStatus DecodeVST3LN(MCInst &Inst, unsigned Insn,
377                                uint64_t Address, const void *Decoder);
378 static DecodeStatus DecodeVST4LN(MCInst &Inst, unsigned Insn,
379                                uint64_t Address, const void *Decoder);
380 static DecodeStatus DecodeVMOVSRR(MCInst &Inst, unsigned Insn,
381                                uint64_t Address, const void *Decoder);
382 static DecodeStatus DecodeVMOVRRS(MCInst &Inst, unsigned Insn,
383                                uint64_t Address, const void *Decoder);
384 static DecodeStatus DecodeSwap(MCInst &Inst, unsigned Insn,
385                                uint64_t Address, const void *Decoder);
386 static DecodeStatus DecodeVCVTD(MCInst &Inst, unsigned Insn,
387                                 uint64_t Address, const void *Decoder);
388 static DecodeStatus DecodeVCVTQ(MCInst &Inst, unsigned Insn,
389                                 uint64_t Address, const void *Decoder);
390 static DecodeStatus DecodeVCVTImmOperand(MCInst &Inst, unsigned Insn,
391                                          uint64_t Address, const void *Decoder);
392 static DecodeStatus DecodeNEONComplexLane64Instruction(MCInst &Inst,
393                                                        unsigned Val,
394                                                        uint64_t Address,
395                                                        const void *Decoder);
396 
397 static DecodeStatus DecodeThumbAddSpecialReg(MCInst &Inst, uint16_t Insn,
398                                uint64_t Address, const void *Decoder);
399 static DecodeStatus DecodeThumbBROperand(MCInst &Inst, unsigned Val,
400                                uint64_t Address, const void *Decoder);
401 static DecodeStatus DecodeT2BROperand(MCInst &Inst, unsigned Val,
402                                uint64_t Address, const void *Decoder);
403 static DecodeStatus DecodeThumbCmpBROperand(MCInst &Inst, unsigned Val,
404                                uint64_t Address, const void *Decoder);
405 static DecodeStatus DecodeThumbAddrModeRR(MCInst &Inst, unsigned Val,
406                                uint64_t Address, const void *Decoder);
407 static DecodeStatus DecodeThumbAddrModeIS(MCInst &Inst, unsigned Val,
408                                uint64_t Address, const void *Decoder);
409 static DecodeStatus DecodeThumbAddrModePC(MCInst &Inst, unsigned Val,
410                                uint64_t Address, const void *Decoder);
411 static DecodeStatus DecodeThumbAddrModeSP(MCInst &Inst, unsigned Val,
412                                uint64_t Address, const void *Decoder);
413 static DecodeStatus DecodeT2AddrModeSOReg(MCInst &Inst, unsigned Val,
414                                uint64_t Address, const void *Decoder);
415 static DecodeStatus DecodeT2LoadShift(MCInst &Inst, unsigned Val,
416                                uint64_t Address, const void *Decoder);
417 static DecodeStatus DecodeT2LoadImm8(MCInst &Inst, unsigned Insn,
418                                uint64_t Address, const void* Decoder);
419 static DecodeStatus DecodeT2LoadImm12(MCInst &Inst, unsigned Insn,
420                                uint64_t Address, const void* Decoder);
421 static DecodeStatus DecodeT2LoadT(MCInst &Inst, unsigned Insn,
422                                uint64_t Address, const void* Decoder);
423 static DecodeStatus DecodeT2LoadLabel(MCInst &Inst, unsigned Insn,
424                                uint64_t Address, const void* Decoder);
425 static DecodeStatus DecodeT2Imm8S4(MCInst &Inst, unsigned Val,
426                                uint64_t Address, const void *Decoder);
427 static DecodeStatus DecodeT2Imm7S4(MCInst &Inst, unsigned Val,
428                                uint64_t Address, const void *Decoder);
429 static DecodeStatus DecodeT2AddrModeImm8s4(MCInst &Inst, unsigned Val,
430                                uint64_t Address, const void *Decoder);
431 static DecodeStatus DecodeT2AddrModeImm7s4(MCInst &Inst, unsigned Val,
432                                            uint64_t Address,
433                                            const void *Decoder);
434 static DecodeStatus DecodeT2AddrModeImm0_1020s4(MCInst &Inst,unsigned Val,
435                                uint64_t Address, const void *Decoder);
436 static DecodeStatus DecodeT2Imm8(MCInst &Inst, unsigned Val,
437                                uint64_t Address, const void *Decoder);
438 template<int shift>
439 static DecodeStatus DecodeT2Imm7(MCInst &Inst, unsigned Val,
440                                uint64_t Address, const void *Decoder);
441 static DecodeStatus DecodeT2AddrModeImm8(MCInst &Inst, unsigned Val,
442                                uint64_t Address, const void *Decoder);
443 template<int shift>
444 static DecodeStatus DecodeTAddrModeImm7(MCInst &Inst, unsigned Val,
445                                uint64_t Address, const void *Decoder);
446 template<int shift, int WriteBack>
447 static DecodeStatus DecodeT2AddrModeImm7(MCInst &Inst, unsigned Val,
448                                uint64_t Address, const void *Decoder);
449 static DecodeStatus DecodeThumbAddSPImm(MCInst &Inst, uint16_t Val,
450                                uint64_t Address, const void *Decoder);
451 static DecodeStatus DecodeThumbAddSPReg(MCInst &Inst, uint16_t Insn,
452                                 uint64_t Address, const void *Decoder);
453 static DecodeStatus DecodeThumbCPS(MCInst &Inst, uint16_t Insn,
454                                 uint64_t Address, const void *Decoder);
455 static DecodeStatus DecodeQADDInstruction(MCInst &Inst, unsigned Insn,
456                                 uint64_t Address, const void *Decoder);
457 static DecodeStatus DecodeThumbBLXOffset(MCInst &Inst, unsigned Insn,
458                                 uint64_t Address, const void *Decoder);
459 static DecodeStatus DecodeT2AddrModeImm12(MCInst &Inst, unsigned Val,
460                                 uint64_t Address, const void *Decoder);
461 static DecodeStatus DecodeThumbTableBranch(MCInst &Inst, unsigned Val,
462                                 uint64_t Address, const void *Decoder);
463 static DecodeStatus DecodeThumb2BCCInstruction(MCInst &Inst, unsigned Val,
464                                 uint64_t Address, const void *Decoder);
465 static DecodeStatus DecodeT2SOImm(MCInst &Inst, unsigned Val,
466                                 uint64_t Address, const void *Decoder);
467 static DecodeStatus DecodeThumbBCCTargetOperand(MCInst &Inst,unsigned Val,
468                                 uint64_t Address, const void *Decoder);
469 static DecodeStatus DecodeThumbBLTargetOperand(MCInst &Inst, unsigned Val,
470                                 uint64_t Address, const void *Decoder);
471 static DecodeStatus DecodeIT(MCInst &Inst, unsigned Val,
472                                 uint64_t Address, const void *Decoder);
473 static DecodeStatus DecodeT2LDRDPreInstruction(MCInst &Inst,unsigned Insn,
474                                uint64_t Address, const void *Decoder);
475 static DecodeStatus DecodeT2STRDPreInstruction(MCInst &Inst,unsigned Insn,
476                                uint64_t Address, const void *Decoder);
477 static DecodeStatus DecodeT2Adr(MCInst &Inst, unsigned Val,
478                                 uint64_t Address, const void *Decoder);
479 static DecodeStatus DecodeT2LdStPre(MCInst &Inst, unsigned Val,
480                                 uint64_t Address, const void *Decoder);
481 static DecodeStatus DecodeT2ShifterImmOperand(MCInst &Inst, unsigned Val,
482                                 uint64_t Address, const void *Decoder);
483 
484 static DecodeStatus DecodeLDR(MCInst &Inst, unsigned Val,
485                                 uint64_t Address, const void *Decoder);
486 static DecodeStatus DecoderForMRRC2AndMCRR2(MCInst &Inst, unsigned Val,
487                                             uint64_t Address, const void *Decoder);
488 static DecodeStatus DecodeForVMRSandVMSR(MCInst &Inst, unsigned Val,
489                                          uint64_t Address, const void *Decoder);
490 
491 template <bool isSigned, bool isNeg, int size>
492 static DecodeStatus DecodeBFLabelOperand(MCInst &Inst, unsigned val,
493                                          uint64_t Address, const void *Decoder);
494 static DecodeStatus DecodeBFAfterTargetOperand(MCInst &Inst, unsigned val,
495                                                uint64_t Address,
496                                                const void *Decoder);
497 static DecodeStatus DecodePredNoALOperand(MCInst &Inst, unsigned Val,
498                                           uint64_t Address,
499                                           const void *Decoder);
500 static DecodeStatus DecodeLOLoop(MCInst &Inst, unsigned Insn, uint64_t Address,
501                                  const void *Decoder);
502 static DecodeStatus DecodeLongShiftOperand(MCInst &Inst, unsigned Val,
503                                            uint64_t Address,
504                                            const void *Decoder);
505 static DecodeStatus DecodeVSCCLRM(MCInst &Inst, unsigned Insn, uint64_t Address,
506                                   const void *Decoder);
507 static DecodeStatus DecodeVPTMaskOperand(MCInst &Inst, unsigned Val,
508                                          uint64_t Address, const void *Decoder);
509 static DecodeStatus DecodeVpredROperand(MCInst &Inst, unsigned Val,
510                                         uint64_t Address, const void *Decoder);
511 static DecodeStatus DecodeRestrictedIPredicateOperand(MCInst &Inst, unsigned Val,
512                                                      uint64_t Address,
513                                                      const void *Decoder);
514 static DecodeStatus DecodeRestrictedSPredicateOperand(MCInst &Inst, unsigned Val,
515                                                      uint64_t Address,
516                                                      const void *Decoder);
517 static DecodeStatus DecodeRestrictedUPredicateOperand(MCInst &Inst, unsigned Val,
518                                                      uint64_t Address,
519                                                      const void *Decoder);
520 static DecodeStatus DecodeRestrictedFPPredicateOperand(MCInst &Inst,
521                                                        unsigned Val,
522                                                        uint64_t Address,
523                                                        const void *Decoder);
524 template<bool Writeback>
525 static DecodeStatus DecodeVSTRVLDR_SYSREG(MCInst &Inst, unsigned Insn,
526                                           uint64_t Address,
527                                           const void *Decoder);
528 template<int shift>
529 static DecodeStatus DecodeMVE_MEM_1_pre(MCInst &Inst, unsigned Val,
530                                         uint64_t Address, const void *Decoder);
531 template<int shift>
532 static DecodeStatus DecodeMVE_MEM_2_pre(MCInst &Inst, unsigned Val,
533                                         uint64_t Address, const void *Decoder);
534 template<int shift>
535 static DecodeStatus DecodeMVE_MEM_3_pre(MCInst &Inst, unsigned Val,
536                                         uint64_t Address, const void *Decoder);
537 template<unsigned MinLog, unsigned MaxLog>
538 static DecodeStatus DecodePowerTwoOperand(MCInst &Inst, unsigned Val,
539                                           uint64_t Address,
540                                           const void *Decoder);
541 template <int shift>
542 static DecodeStatus DecodeExpandedImmOperand(MCInst &Inst, unsigned Val,
543                                              uint64_t Address,
544                                              const void *Decoder);
545 template<unsigned start>
546 static DecodeStatus DecodeMVEPairVectorIndexOperand(MCInst &Inst, unsigned Val,
547                                                     uint64_t Address,
548                                                     const void *Decoder);
549 static DecodeStatus DecodeMVEVMOVQtoDReg(MCInst &Inst, unsigned Insn,
550                                          uint64_t Address,
551                                          const void *Decoder);
552 static DecodeStatus DecodeMVEVMOVDRegtoQ(MCInst &Inst, unsigned Insn,
553                                          uint64_t Address,
554                                          const void *Decoder);
555 static DecodeStatus DecodeMVEVCVTt1fp(MCInst &Inst, unsigned Insn,
556                                       uint64_t Address, const void *Decoder);
557 typedef DecodeStatus OperandDecoder(MCInst &Inst, unsigned Val,
558                                     uint64_t Address, const void *Decoder);
559 template<bool scalar, OperandDecoder predicate_decoder>
560 static DecodeStatus DecodeMVEVCMP(MCInst &Inst, unsigned Insn,
561                                   uint64_t Address, const void *Decoder);
562 static DecodeStatus DecodeMveVCTP(MCInst &Inst, unsigned Insn,
563                                   uint64_t Address, const void *Decoder);
564 static DecodeStatus DecodeMVEOverlappingLongShift(MCInst &Inst, unsigned Insn,
565                                                   uint64_t Address,
566                                                   const void *Decoder);
567 #include "ARMGenDisassemblerTables.inc"
568 
569 static MCDisassembler *createARMDisassembler(const Target &T,
570                                              const MCSubtargetInfo &STI,
571                                              MCContext &Ctx) {
572   return new ARMDisassembler(STI, Ctx);
573 }
574 
575 // Post-decoding checks
576 static DecodeStatus checkDecodedInstruction(MCInst &MI, uint64_t &Size,
577                                             uint64_t Address, raw_ostream &OS,
578                                             raw_ostream &CS,
579                                             uint32_t Insn,
580                                             DecodeStatus Result) {
581   switch (MI.getOpcode()) {
582     case ARM::HVC: {
583       // HVC is undefined if condition = 0xf otherwise upredictable
584       // if condition != 0xe
585       uint32_t Cond = (Insn >> 28) & 0xF;
586       if (Cond == 0xF)
587         return MCDisassembler::Fail;
588       if (Cond != 0xE)
589         return MCDisassembler::SoftFail;
590       return Result;
591     }
592     case ARM::t2ADDri:
593     case ARM::t2ADDri12:
594     case ARM::t2ADDrr:
595     case ARM::t2ADDrs:
596     case ARM::t2SUBri:
597     case ARM::t2SUBri12:
598     case ARM::t2SUBrr:
599     case ARM::t2SUBrs:
600       if (MI.getOperand(0).getReg() == ARM::SP &&
601           MI.getOperand(1).getReg() != ARM::SP)
602         return MCDisassembler::SoftFail;
603       return Result;
604     default: return Result;
605   }
606 }
607 
608 DecodeStatus ARMDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
609                                              ArrayRef<uint8_t> Bytes,
610                                              uint64_t Address, raw_ostream &OS,
611                                              raw_ostream &CS) const {
612   if (STI.getFeatureBits()[ARM::ModeThumb])
613     return getThumbInstruction(MI, Size, Bytes, Address, OS, CS);
614   return getARMInstruction(MI, Size, Bytes, Address, OS, CS);
615 }
616 
617 DecodeStatus ARMDisassembler::getARMInstruction(MCInst &MI, uint64_t &Size,
618                                                 ArrayRef<uint8_t> Bytes,
619                                                 uint64_t Address,
620                                                 raw_ostream &OS,
621                                                 raw_ostream &CS) const {
622   CommentStream = &CS;
623 
624   assert(!STI.getFeatureBits()[ARM::ModeThumb] &&
625          "Asked to disassemble an ARM instruction but Subtarget is in Thumb "
626          "mode!");
627 
628   // We want to read exactly 4 bytes of data.
629   if (Bytes.size() < 4) {
630     Size = 0;
631     return MCDisassembler::Fail;
632   }
633 
634   // Encoded as a small-endian 32-bit word in the stream.
635   uint32_t Insn =
636       (Bytes[3] << 24) | (Bytes[2] << 16) | (Bytes[1] << 8) | (Bytes[0] << 0);
637 
638   // Calling the auto-generated decoder function.
639   DecodeStatus Result =
640       decodeInstruction(DecoderTableARM32, MI, Insn, Address, this, STI);
641   if (Result != MCDisassembler::Fail) {
642     Size = 4;
643     return checkDecodedInstruction(MI, Size, Address, OS, CS, Insn, Result);
644   }
645 
646   struct DecodeTable {
647     const uint8_t *P;
648     bool DecodePred;
649   };
650 
651   const DecodeTable Tables[] = {
652       {DecoderTableVFP32, false},      {DecoderTableVFPV832, false},
653       {DecoderTableNEONData32, true},  {DecoderTableNEONLoadStore32, true},
654       {DecoderTableNEONDup32, true},   {DecoderTablev8NEON32, false},
655       {DecoderTablev8Crypto32, false},
656   };
657 
658   for (auto Table : Tables) {
659     Result = decodeInstruction(Table.P, MI, Insn, Address, this, STI);
660     if (Result != MCDisassembler::Fail) {
661       Size = 4;
662       // Add a fake predicate operand, because we share these instruction
663       // definitions with Thumb2 where these instructions are predicable.
664       if (Table.DecodePred && !DecodePredicateOperand(MI, 0xE, Address, this))
665         return MCDisassembler::Fail;
666       return Result;
667     }
668   }
669 
670   Result =
671       decodeInstruction(DecoderTableCoProc32, MI, Insn, Address, this, STI);
672   if (Result != MCDisassembler::Fail) {
673     Size = 4;
674     return checkDecodedInstruction(MI, Size, Address, OS, CS, Insn, Result);
675   }
676 
677   Size = 4;
678   return MCDisassembler::Fail;
679 }
680 
681 namespace llvm {
682 
683 extern const MCInstrDesc ARMInsts[];
684 
685 } // end namespace llvm
686 
687 /// tryAddingSymbolicOperand - trys to add a symbolic operand in place of the
688 /// immediate Value in the MCInst.  The immediate Value has had any PC
689 /// adjustment made by the caller.  If the instruction is a branch instruction
690 /// then isBranch is true, else false.  If the getOpInfo() function was set as
691 /// part of the setupForSymbolicDisassembly() call then that function is called
692 /// to get any symbolic information at the Address for this instruction.  If
693 /// that returns non-zero then the symbolic information it returns is used to
694 /// create an MCExpr and that is added as an operand to the MCInst.  If
695 /// getOpInfo() returns zero and isBranch is true then a symbol look up for
696 /// Value is done and if a symbol is found an MCExpr is created with that, else
697 /// an MCExpr with Value is created.  This function returns true if it adds an
698 /// operand to the MCInst and false otherwise.
699 static bool tryAddingSymbolicOperand(uint64_t Address, int32_t Value,
700                                      bool isBranch, uint64_t InstSize,
701                                      MCInst &MI, const void *Decoder) {
702   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
703   // FIXME: Does it make sense for value to be negative?
704   return Dis->tryAddingSymbolicOperand(MI, (uint32_t)Value, Address, isBranch,
705                                        /* Offset */ 0, InstSize);
706 }
707 
708 /// tryAddingPcLoadReferenceComment - trys to add a comment as to what is being
709 /// referenced by a load instruction with the base register that is the Pc.
710 /// These can often be values in a literal pool near the Address of the
711 /// instruction.  The Address of the instruction and its immediate Value are
712 /// used as a possible literal pool entry.  The SymbolLookUp call back will
713 /// return the name of a symbol referenced by the literal pool's entry if
714 /// the referenced address is that of a symbol.  Or it will return a pointer to
715 /// a literal 'C' string if the referenced address of the literal pool's entry
716 /// is an address into a section with 'C' string literals.
717 static void tryAddingPcLoadReferenceComment(uint64_t Address, int Value,
718                                             const void *Decoder) {
719   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
720   Dis->tryAddingPcLoadReferenceComment(Value, Address);
721 }
722 
723 // Thumb1 instructions don't have explicit S bits.  Rather, they
724 // implicitly set CPSR.  Since it's not represented in the encoding, the
725 // auto-generated decoder won't inject the CPSR operand.  We need to fix
726 // that as a post-pass.
727 static void AddThumb1SBit(MCInst &MI, bool InITBlock) {
728   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
729   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
730   MCInst::iterator I = MI.begin();
731   for (unsigned i = 0; i < NumOps; ++i, ++I) {
732     if (I == MI.end()) break;
733     if (OpInfo[i].isOptionalDef() && OpInfo[i].RegClass == ARM::CCRRegClassID) {
734       if (i > 0 && OpInfo[i-1].isPredicate()) continue;
735       MI.insert(I, MCOperand::createReg(InITBlock ? 0 : ARM::CPSR));
736       return;
737     }
738   }
739 
740   MI.insert(I, MCOperand::createReg(InITBlock ? 0 : ARM::CPSR));
741 }
742 
743 static bool isVectorPredicable(unsigned Opcode) {
744   const MCOperandInfo *OpInfo = ARMInsts[Opcode].OpInfo;
745   unsigned short NumOps = ARMInsts[Opcode].NumOperands;
746   for (unsigned i = 0; i < NumOps; ++i) {
747     if (ARM::isVpred(OpInfo[i].OperandType))
748       return true;
749   }
750   return false;
751 }
752 
753 // Most Thumb instructions don't have explicit predicates in the
754 // encoding, but rather get their predicates from IT context.  We need
755 // to fix up the predicate operands using this context information as a
756 // post-pass.
757 MCDisassembler::DecodeStatus
758 ARMDisassembler::AddThumbPredicate(MCInst &MI) const {
759   MCDisassembler::DecodeStatus S = Success;
760 
761   const FeatureBitset &FeatureBits = getSubtargetInfo().getFeatureBits();
762 
763   // A few instructions actually have predicates encoded in them.  Don't
764   // try to overwrite it if we're seeing one of those.
765   switch (MI.getOpcode()) {
766     case ARM::tBcc:
767     case ARM::t2Bcc:
768     case ARM::tCBZ:
769     case ARM::tCBNZ:
770     case ARM::tCPS:
771     case ARM::t2CPS3p:
772     case ARM::t2CPS2p:
773     case ARM::t2CPS1p:
774     case ARM::t2CSEL:
775     case ARM::t2CSINC:
776     case ARM::t2CSINV:
777     case ARM::t2CSNEG:
778     case ARM::tMOVSr:
779     case ARM::tSETEND:
780       // Some instructions (mostly conditional branches) are not
781       // allowed in IT blocks.
782       if (ITBlock.instrInITBlock())
783         S = SoftFail;
784       else
785         return Success;
786       break;
787     case ARM::t2HINT:
788       if (MI.getOperand(0).getImm() == 0x10 && (FeatureBits[ARM::FeatureRAS]) != 0)
789         S = SoftFail;
790       break;
791     case ARM::tB:
792     case ARM::t2B:
793     case ARM::t2TBB:
794     case ARM::t2TBH:
795       // Some instructions (mostly unconditional branches) can
796       // only appears at the end of, or outside of, an IT.
797       if (ITBlock.instrInITBlock() && !ITBlock.instrLastInITBlock())
798         S = SoftFail;
799       break;
800     default:
801       break;
802   }
803 
804   // Warn on non-VPT predicable instruction in a VPT block and a VPT
805   // predicable instruction in an IT block
806   if ((!isVectorPredicable(MI.getOpcode()) && VPTBlock.instrInVPTBlock()) ||
807        (isVectorPredicable(MI.getOpcode()) && ITBlock.instrInITBlock()))
808     S = SoftFail;
809 
810   // If we're in an IT/VPT block, base the predicate on that.  Otherwise,
811   // assume a predicate of AL.
812   unsigned CC = ARMCC::AL;
813   unsigned VCC = ARMVCC::None;
814   if (ITBlock.instrInITBlock()) {
815     CC = ITBlock.getITCC();
816     ITBlock.advanceITState();
817   } else if (VPTBlock.instrInVPTBlock()) {
818     VCC = VPTBlock.getVPTPred();
819     VPTBlock.advanceVPTState();
820   }
821 
822   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
823   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
824 
825   MCInst::iterator CCI = MI.begin();
826   for (unsigned i = 0; i < NumOps; ++i, ++CCI) {
827     if (OpInfo[i].isPredicate() || CCI == MI.end()) break;
828   }
829 
830   if (ARMInsts[MI.getOpcode()].isPredicable()) {
831     CCI = MI.insert(CCI, MCOperand::createImm(CC));
832     ++CCI;
833     if (CC == ARMCC::AL)
834       MI.insert(CCI, MCOperand::createReg(0));
835     else
836       MI.insert(CCI, MCOperand::createReg(ARM::CPSR));
837   } else if (CC != ARMCC::AL) {
838     Check(S, SoftFail);
839   }
840 
841   MCInst::iterator VCCI = MI.begin();
842   unsigned VCCPos;
843   for (VCCPos = 0; VCCPos < NumOps; ++VCCPos, ++VCCI) {
844     if (ARM::isVpred(OpInfo[VCCPos].OperandType) || VCCI == MI.end()) break;
845   }
846 
847   if (isVectorPredicable(MI.getOpcode())) {
848     VCCI = MI.insert(VCCI, MCOperand::createImm(VCC));
849     ++VCCI;
850     if (VCC == ARMVCC::None)
851       MI.insert(VCCI, MCOperand::createReg(0));
852     else
853       MI.insert(VCCI, MCOperand::createReg(ARM::P0));
854     if (OpInfo[VCCPos].OperandType == ARM::OPERAND_VPRED_R) {
855       int TiedOp = ARMInsts[MI.getOpcode()].getOperandConstraint(
856         VCCPos + 2, MCOI::TIED_TO);
857       assert(TiedOp >= 0 &&
858              "Inactive register in vpred_r is not tied to an output!");
859       MI.insert(VCCI, MI.getOperand(TiedOp));
860     }
861   } else if (VCC != ARMVCC::None) {
862     Check(S, SoftFail);
863   }
864 
865   return S;
866 }
867 
868 // Thumb VFP instructions are a special case.  Because we share their
869 // encodings between ARM and Thumb modes, and they are predicable in ARM
870 // mode, the auto-generated decoder will give them an (incorrect)
871 // predicate operand.  We need to rewrite these operands based on the IT
872 // context as a post-pass.
873 void ARMDisassembler::UpdateThumbVFPPredicate(
874   DecodeStatus &S, MCInst &MI) const {
875   unsigned CC;
876   CC = ITBlock.getITCC();
877   if (CC == 0xF)
878     CC = ARMCC::AL;
879   if (ITBlock.instrInITBlock())
880     ITBlock.advanceITState();
881   else if (VPTBlock.instrInVPTBlock()) {
882     CC = VPTBlock.getVPTPred();
883     VPTBlock.advanceVPTState();
884   }
885 
886   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
887   MCInst::iterator I = MI.begin();
888   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
889   for (unsigned i = 0; i < NumOps; ++i, ++I) {
890     if (OpInfo[i].isPredicate() ) {
891       if (CC != ARMCC::AL && !ARMInsts[MI.getOpcode()].isPredicable())
892         Check(S, SoftFail);
893       I->setImm(CC);
894       ++I;
895       if (CC == ARMCC::AL)
896         I->setReg(0);
897       else
898         I->setReg(ARM::CPSR);
899       return;
900     }
901   }
902 }
903 
904 DecodeStatus ARMDisassembler::getThumbInstruction(MCInst &MI, uint64_t &Size,
905                                                   ArrayRef<uint8_t> Bytes,
906                                                   uint64_t Address,
907                                                   raw_ostream &OS,
908                                                   raw_ostream &CS) const {
909   CommentStream = &CS;
910 
911   assert(STI.getFeatureBits()[ARM::ModeThumb] &&
912          "Asked to disassemble in Thumb mode but Subtarget is in ARM mode!");
913 
914   // We want to read exactly 2 bytes of data.
915   if (Bytes.size() < 2) {
916     Size = 0;
917     return MCDisassembler::Fail;
918   }
919 
920   uint16_t Insn16 = (Bytes[1] << 8) | Bytes[0];
921   DecodeStatus Result =
922       decodeInstruction(DecoderTableThumb16, MI, Insn16, Address, this, STI);
923   if (Result != MCDisassembler::Fail) {
924     Size = 2;
925     Check(Result, AddThumbPredicate(MI));
926     return Result;
927   }
928 
929   Result = decodeInstruction(DecoderTableThumbSBit16, MI, Insn16, Address, this,
930                              STI);
931   if (Result) {
932     Size = 2;
933     bool InITBlock = ITBlock.instrInITBlock();
934     Check(Result, AddThumbPredicate(MI));
935     AddThumb1SBit(MI, InITBlock);
936     return Result;
937   }
938 
939   Result =
940       decodeInstruction(DecoderTableThumb216, MI, Insn16, Address, this, STI);
941   if (Result != MCDisassembler::Fail) {
942     Size = 2;
943 
944     // Nested IT blocks are UNPREDICTABLE.  Must be checked before we add
945     // the Thumb predicate.
946     if (MI.getOpcode() == ARM::t2IT && ITBlock.instrInITBlock())
947       Result = MCDisassembler::SoftFail;
948 
949     Check(Result, AddThumbPredicate(MI));
950 
951     // If we find an IT instruction, we need to parse its condition
952     // code and mask operands so that we can apply them correctly
953     // to the subsequent instructions.
954     if (MI.getOpcode() == ARM::t2IT) {
955       unsigned Firstcond = MI.getOperand(0).getImm();
956       unsigned Mask = MI.getOperand(1).getImm();
957       ITBlock.setITState(Firstcond, Mask);
958 
959       // An IT instruction that would give a 'NV' predicate is unpredictable.
960       if (Firstcond == ARMCC::AL && !isPowerOf2_32(Mask))
961         CS << "unpredictable IT predicate sequence";
962     }
963 
964     return Result;
965   }
966 
967   // We want to read exactly 4 bytes of data.
968   if (Bytes.size() < 4) {
969     Size = 0;
970     return MCDisassembler::Fail;
971   }
972 
973   uint32_t Insn32 =
974       (Bytes[3] << 8) | (Bytes[2] << 0) | (Bytes[1] << 24) | (Bytes[0] << 16);
975 
976   Result =
977       decodeInstruction(DecoderTableMVE32, MI, Insn32, Address, this, STI);
978   if (Result != MCDisassembler::Fail) {
979     Size = 4;
980 
981     // Nested VPT blocks are UNPREDICTABLE. Must be checked before we add
982     // the VPT predicate.
983     if (isVPTOpcode(MI.getOpcode()) && VPTBlock.instrInVPTBlock())
984       Result = MCDisassembler::SoftFail;
985 
986     Check(Result, AddThumbPredicate(MI));
987 
988     if (isVPTOpcode(MI.getOpcode())) {
989       unsigned Mask = MI.getOperand(0).getImm();
990       VPTBlock.setVPTState(Mask);
991     }
992 
993     return Result;
994   }
995 
996   Result =
997       decodeInstruction(DecoderTableThumb32, MI, Insn32, Address, this, STI);
998   if (Result != MCDisassembler::Fail) {
999     Size = 4;
1000     bool InITBlock = ITBlock.instrInITBlock();
1001     Check(Result, AddThumbPredicate(MI));
1002     AddThumb1SBit(MI, InITBlock);
1003     return Result;
1004   }
1005 
1006   Result =
1007       decodeInstruction(DecoderTableThumb232, MI, Insn32, Address, this, STI);
1008   if (Result != MCDisassembler::Fail) {
1009     Size = 4;
1010     Check(Result, AddThumbPredicate(MI));
1011     return checkDecodedInstruction(MI, Size, Address, OS, CS, Insn32, Result);
1012   }
1013 
1014   if (fieldFromInstruction(Insn32, 28, 4) == 0xE) {
1015     Result =
1016         decodeInstruction(DecoderTableVFP32, MI, Insn32, Address, this, STI);
1017     if (Result != MCDisassembler::Fail) {
1018       Size = 4;
1019       UpdateThumbVFPPredicate(Result, MI);
1020       return Result;
1021     }
1022   }
1023 
1024   Result =
1025       decodeInstruction(DecoderTableVFPV832, MI, Insn32, Address, this, STI);
1026   if (Result != MCDisassembler::Fail) {
1027     Size = 4;
1028     return Result;
1029   }
1030 
1031   if (fieldFromInstruction(Insn32, 28, 4) == 0xE) {
1032     Result = decodeInstruction(DecoderTableNEONDup32, MI, Insn32, Address, this,
1033                                STI);
1034     if (Result != MCDisassembler::Fail) {
1035       Size = 4;
1036       Check(Result, AddThumbPredicate(MI));
1037       return Result;
1038     }
1039   }
1040 
1041   if (fieldFromInstruction(Insn32, 24, 8) == 0xF9) {
1042     uint32_t NEONLdStInsn = Insn32;
1043     NEONLdStInsn &= 0xF0FFFFFF;
1044     NEONLdStInsn |= 0x04000000;
1045     Result = decodeInstruction(DecoderTableNEONLoadStore32, MI, NEONLdStInsn,
1046                                Address, this, STI);
1047     if (Result != MCDisassembler::Fail) {
1048       Size = 4;
1049       Check(Result, AddThumbPredicate(MI));
1050       return Result;
1051     }
1052   }
1053 
1054   if (fieldFromInstruction(Insn32, 24, 4) == 0xF) {
1055     uint32_t NEONDataInsn = Insn32;
1056     NEONDataInsn &= 0xF0FFFFFF; // Clear bits 27-24
1057     NEONDataInsn |= (NEONDataInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
1058     NEONDataInsn |= 0x12000000; // Set bits 28 and 25
1059     Result = decodeInstruction(DecoderTableNEONData32, MI, NEONDataInsn,
1060                                Address, this, STI);
1061     if (Result != MCDisassembler::Fail) {
1062       Size = 4;
1063       Check(Result, AddThumbPredicate(MI));
1064       return Result;
1065     }
1066 
1067     uint32_t NEONCryptoInsn = Insn32;
1068     NEONCryptoInsn &= 0xF0FFFFFF; // Clear bits 27-24
1069     NEONCryptoInsn |= (NEONCryptoInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
1070     NEONCryptoInsn |= 0x12000000; // Set bits 28 and 25
1071     Result = decodeInstruction(DecoderTablev8Crypto32, MI, NEONCryptoInsn,
1072                                Address, this, STI);
1073     if (Result != MCDisassembler::Fail) {
1074       Size = 4;
1075       return Result;
1076     }
1077 
1078     uint32_t NEONv8Insn = Insn32;
1079     NEONv8Insn &= 0xF3FFFFFF; // Clear bits 27-26
1080     Result = decodeInstruction(DecoderTablev8NEON32, MI, NEONv8Insn, Address,
1081                                this, STI);
1082     if (Result != MCDisassembler::Fail) {
1083       Size = 4;
1084       return Result;
1085     }
1086   }
1087 
1088   Result =
1089       decodeInstruction(DecoderTableThumb2CoProc32, MI, Insn32, Address, this, STI);
1090   if (Result != MCDisassembler::Fail) {
1091     Size = 4;
1092     Check(Result, AddThumbPredicate(MI));
1093     return Result;
1094   }
1095 
1096   Size = 0;
1097   return MCDisassembler::Fail;
1098 }
1099 
1100 extern "C" void LLVMInitializeARMDisassembler() {
1101   TargetRegistry::RegisterMCDisassembler(getTheARMLETarget(),
1102                                          createARMDisassembler);
1103   TargetRegistry::RegisterMCDisassembler(getTheARMBETarget(),
1104                                          createARMDisassembler);
1105   TargetRegistry::RegisterMCDisassembler(getTheThumbLETarget(),
1106                                          createARMDisassembler);
1107   TargetRegistry::RegisterMCDisassembler(getTheThumbBETarget(),
1108                                          createARMDisassembler);
1109 }
1110 
1111 static const uint16_t GPRDecoderTable[] = {
1112   ARM::R0, ARM::R1, ARM::R2, ARM::R3,
1113   ARM::R4, ARM::R5, ARM::R6, ARM::R7,
1114   ARM::R8, ARM::R9, ARM::R10, ARM::R11,
1115   ARM::R12, ARM::SP, ARM::LR, ARM::PC
1116 };
1117 
1118 static const uint16_t CLRMGPRDecoderTable[] = {
1119   ARM::R0, ARM::R1, ARM::R2, ARM::R3,
1120   ARM::R4, ARM::R5, ARM::R6, ARM::R7,
1121   ARM::R8, ARM::R9, ARM::R10, ARM::R11,
1122   ARM::R12, 0, ARM::LR, ARM::APSR
1123 };
1124 
1125 static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1126                                    uint64_t Address, const void *Decoder) {
1127   if (RegNo > 15)
1128     return MCDisassembler::Fail;
1129 
1130   unsigned Register = GPRDecoderTable[RegNo];
1131   Inst.addOperand(MCOperand::createReg(Register));
1132   return MCDisassembler::Success;
1133 }
1134 
1135 static DecodeStatus DecodeCLRMGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1136                                                uint64_t Address,
1137                                                const void *Decoder) {
1138   if (RegNo > 15)
1139     return MCDisassembler::Fail;
1140 
1141   unsigned Register = CLRMGPRDecoderTable[RegNo];
1142   if (Register == 0)
1143     return MCDisassembler::Fail;
1144 
1145   Inst.addOperand(MCOperand::createReg(Register));
1146   return MCDisassembler::Success;
1147 }
1148 
1149 static DecodeStatus
1150 DecodeGPRnopcRegisterClass(MCInst &Inst, unsigned RegNo,
1151                            uint64_t Address, const void *Decoder) {
1152   DecodeStatus S = MCDisassembler::Success;
1153 
1154   if (RegNo == 15)
1155     S = MCDisassembler::SoftFail;
1156 
1157   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1158 
1159   return S;
1160 }
1161 
1162 static DecodeStatus
1163 DecodeGPRwithAPSRRegisterClass(MCInst &Inst, unsigned RegNo,
1164                                uint64_t Address, const void *Decoder) {
1165   DecodeStatus S = MCDisassembler::Success;
1166 
1167   if (RegNo == 15)
1168   {
1169     Inst.addOperand(MCOperand::createReg(ARM::APSR_NZCV));
1170     return MCDisassembler::Success;
1171   }
1172 
1173   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1174   return S;
1175 }
1176 
1177 static DecodeStatus
1178 DecodeGPRwithZRRegisterClass(MCInst &Inst, unsigned RegNo,
1179                              uint64_t Address, const void *Decoder) {
1180   DecodeStatus S = MCDisassembler::Success;
1181 
1182   if (RegNo == 15)
1183   {
1184     Inst.addOperand(MCOperand::createReg(ARM::ZR));
1185     return MCDisassembler::Success;
1186   }
1187 
1188   if (RegNo == 13)
1189     Check(S, MCDisassembler::SoftFail);
1190 
1191   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1192   return S;
1193 }
1194 
1195 static DecodeStatus
1196 DecodeGPRwithZRnospRegisterClass(MCInst &Inst, unsigned RegNo,
1197                                  uint64_t Address, const void *Decoder) {
1198   DecodeStatus S = MCDisassembler::Success;
1199   if (RegNo == 13)
1200     return MCDisassembler::Fail;
1201   Check(S, DecodeGPRwithZRRegisterClass(Inst, RegNo, Address, Decoder));
1202   return S;
1203 }
1204 
1205 static DecodeStatus DecodetGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1206                                    uint64_t Address, const void *Decoder) {
1207   if (RegNo > 7)
1208     return MCDisassembler::Fail;
1209   return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
1210 }
1211 
1212 static const uint16_t GPRPairDecoderTable[] = {
1213   ARM::R0_R1, ARM::R2_R3,   ARM::R4_R5,  ARM::R6_R7,
1214   ARM::R8_R9, ARM::R10_R11, ARM::R12_SP
1215 };
1216 
1217 static DecodeStatus DecodeGPRPairRegisterClass(MCInst &Inst, unsigned RegNo,
1218                                    uint64_t Address, const void *Decoder) {
1219   DecodeStatus S = MCDisassembler::Success;
1220 
1221   if (RegNo > 13)
1222     return MCDisassembler::Fail;
1223 
1224   if ((RegNo & 1) || RegNo == 0xe)
1225      S = MCDisassembler::SoftFail;
1226 
1227   unsigned RegisterPair = GPRPairDecoderTable[RegNo/2];
1228   Inst.addOperand(MCOperand::createReg(RegisterPair));
1229   return S;
1230 }
1231 
1232 static DecodeStatus DecodetcGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1233                                    uint64_t Address, const void *Decoder) {
1234   unsigned Register = 0;
1235   switch (RegNo) {
1236     case 0:
1237       Register = ARM::R0;
1238       break;
1239     case 1:
1240       Register = ARM::R1;
1241       break;
1242     case 2:
1243       Register = ARM::R2;
1244       break;
1245     case 3:
1246       Register = ARM::R3;
1247       break;
1248     case 9:
1249       Register = ARM::R9;
1250       break;
1251     case 12:
1252       Register = ARM::R12;
1253       break;
1254     default:
1255       return MCDisassembler::Fail;
1256     }
1257 
1258   Inst.addOperand(MCOperand::createReg(Register));
1259   return MCDisassembler::Success;
1260 }
1261 
1262 static DecodeStatus DecoderGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1263                                    uint64_t Address, const void *Decoder) {
1264   DecodeStatus S = MCDisassembler::Success;
1265 
1266   const FeatureBitset &featureBits =
1267     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1268 
1269   if ((RegNo == 13 && !featureBits[ARM::HasV8Ops]) || RegNo == 15)
1270     S = MCDisassembler::SoftFail;
1271 
1272   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1273   return S;
1274 }
1275 
1276 static const uint16_t SPRDecoderTable[] = {
1277      ARM::S0,  ARM::S1,  ARM::S2,  ARM::S3,
1278      ARM::S4,  ARM::S5,  ARM::S6,  ARM::S7,
1279      ARM::S8,  ARM::S9, ARM::S10, ARM::S11,
1280     ARM::S12, ARM::S13, ARM::S14, ARM::S15,
1281     ARM::S16, ARM::S17, ARM::S18, ARM::S19,
1282     ARM::S20, ARM::S21, ARM::S22, ARM::S23,
1283     ARM::S24, ARM::S25, ARM::S26, ARM::S27,
1284     ARM::S28, ARM::S29, ARM::S30, ARM::S31
1285 };
1286 
1287 static DecodeStatus DecodeSPRRegisterClass(MCInst &Inst, unsigned RegNo,
1288                                    uint64_t Address, const void *Decoder) {
1289   if (RegNo > 31)
1290     return MCDisassembler::Fail;
1291 
1292   unsigned Register = SPRDecoderTable[RegNo];
1293   Inst.addOperand(MCOperand::createReg(Register));
1294   return MCDisassembler::Success;
1295 }
1296 
1297 static DecodeStatus DecodeHPRRegisterClass(MCInst &Inst, unsigned RegNo,
1298                                    uint64_t Address, const void *Decoder) {
1299   return DecodeSPRRegisterClass(Inst, RegNo, Address, Decoder);
1300 }
1301 
1302 static const uint16_t DPRDecoderTable[] = {
1303      ARM::D0,  ARM::D1,  ARM::D2,  ARM::D3,
1304      ARM::D4,  ARM::D5,  ARM::D6,  ARM::D7,
1305      ARM::D8,  ARM::D9, ARM::D10, ARM::D11,
1306     ARM::D12, ARM::D13, ARM::D14, ARM::D15,
1307     ARM::D16, ARM::D17, ARM::D18, ARM::D19,
1308     ARM::D20, ARM::D21, ARM::D22, ARM::D23,
1309     ARM::D24, ARM::D25, ARM::D26, ARM::D27,
1310     ARM::D28, ARM::D29, ARM::D30, ARM::D31
1311 };
1312 
1313 static DecodeStatus DecodeDPRRegisterClass(MCInst &Inst, unsigned RegNo,
1314                                    uint64_t Address, const void *Decoder) {
1315   const FeatureBitset &featureBits =
1316     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1317 
1318   bool hasD32 = featureBits[ARM::FeatureD32];
1319 
1320   if (RegNo > 31 || (!hasD32 && RegNo > 15))
1321     return MCDisassembler::Fail;
1322 
1323   unsigned Register = DPRDecoderTable[RegNo];
1324   Inst.addOperand(MCOperand::createReg(Register));
1325   return MCDisassembler::Success;
1326 }
1327 
1328 static DecodeStatus DecodeDPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
1329                                    uint64_t Address, const void *Decoder) {
1330   if (RegNo > 7)
1331     return MCDisassembler::Fail;
1332   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
1333 }
1334 
1335 static DecodeStatus DecodeSPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
1336                                    uint64_t Address, const void *Decoder) {
1337   if (RegNo > 15)
1338     return MCDisassembler::Fail;
1339   return DecodeSPRRegisterClass(Inst, RegNo, Address, Decoder);
1340 }
1341 
1342 static DecodeStatus
1343 DecodeDPR_VFP2RegisterClass(MCInst &Inst, unsigned RegNo,
1344                             uint64_t Address, const void *Decoder) {
1345   if (RegNo > 15)
1346     return MCDisassembler::Fail;
1347   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
1348 }
1349 
1350 static const uint16_t QPRDecoderTable[] = {
1351      ARM::Q0,  ARM::Q1,  ARM::Q2,  ARM::Q3,
1352      ARM::Q4,  ARM::Q5,  ARM::Q6,  ARM::Q7,
1353      ARM::Q8,  ARM::Q9, ARM::Q10, ARM::Q11,
1354     ARM::Q12, ARM::Q13, ARM::Q14, ARM::Q15
1355 };
1356 
1357 static DecodeStatus DecodeQPRRegisterClass(MCInst &Inst, unsigned RegNo,
1358                                    uint64_t Address, const void *Decoder) {
1359   if (RegNo > 31 || (RegNo & 1) != 0)
1360     return MCDisassembler::Fail;
1361   RegNo >>= 1;
1362 
1363   unsigned Register = QPRDecoderTable[RegNo];
1364   Inst.addOperand(MCOperand::createReg(Register));
1365   return MCDisassembler::Success;
1366 }
1367 
1368 static const uint16_t DPairDecoderTable[] = {
1369   ARM::Q0,  ARM::D1_D2,   ARM::Q1,  ARM::D3_D4,   ARM::Q2,  ARM::D5_D6,
1370   ARM::Q3,  ARM::D7_D8,   ARM::Q4,  ARM::D9_D10,  ARM::Q5,  ARM::D11_D12,
1371   ARM::Q6,  ARM::D13_D14, ARM::Q7,  ARM::D15_D16, ARM::Q8,  ARM::D17_D18,
1372   ARM::Q9,  ARM::D19_D20, ARM::Q10, ARM::D21_D22, ARM::Q11, ARM::D23_D24,
1373   ARM::Q12, ARM::D25_D26, ARM::Q13, ARM::D27_D28, ARM::Q14, ARM::D29_D30,
1374   ARM::Q15
1375 };
1376 
1377 static DecodeStatus DecodeDPairRegisterClass(MCInst &Inst, unsigned RegNo,
1378                                    uint64_t Address, const void *Decoder) {
1379   if (RegNo > 30)
1380     return MCDisassembler::Fail;
1381 
1382   unsigned Register = DPairDecoderTable[RegNo];
1383   Inst.addOperand(MCOperand::createReg(Register));
1384   return MCDisassembler::Success;
1385 }
1386 
1387 static const uint16_t DPairSpacedDecoderTable[] = {
1388   ARM::D0_D2,   ARM::D1_D3,   ARM::D2_D4,   ARM::D3_D5,
1389   ARM::D4_D6,   ARM::D5_D7,   ARM::D6_D8,   ARM::D7_D9,
1390   ARM::D8_D10,  ARM::D9_D11,  ARM::D10_D12, ARM::D11_D13,
1391   ARM::D12_D14, ARM::D13_D15, ARM::D14_D16, ARM::D15_D17,
1392   ARM::D16_D18, ARM::D17_D19, ARM::D18_D20, ARM::D19_D21,
1393   ARM::D20_D22, ARM::D21_D23, ARM::D22_D24, ARM::D23_D25,
1394   ARM::D24_D26, ARM::D25_D27, ARM::D26_D28, ARM::D27_D29,
1395   ARM::D28_D30, ARM::D29_D31
1396 };
1397 
1398 static DecodeStatus DecodeDPairSpacedRegisterClass(MCInst &Inst,
1399                                                    unsigned RegNo,
1400                                                    uint64_t Address,
1401                                                    const void *Decoder) {
1402   if (RegNo > 29)
1403     return MCDisassembler::Fail;
1404 
1405   unsigned Register = DPairSpacedDecoderTable[RegNo];
1406   Inst.addOperand(MCOperand::createReg(Register));
1407   return MCDisassembler::Success;
1408 }
1409 
1410 static DecodeStatus DecodePredicateOperand(MCInst &Inst, unsigned Val,
1411                                uint64_t Address, const void *Decoder) {
1412   DecodeStatus S = MCDisassembler::Success;
1413   if (Val == 0xF) return MCDisassembler::Fail;
1414   // AL predicate is not allowed on Thumb1 branches.
1415   if (Inst.getOpcode() == ARM::tBcc && Val == 0xE)
1416     return MCDisassembler::Fail;
1417   if (Val != ARMCC::AL && !ARMInsts[Inst.getOpcode()].isPredicable())
1418     Check(S, MCDisassembler::SoftFail);
1419   Inst.addOperand(MCOperand::createImm(Val));
1420   if (Val == ARMCC::AL) {
1421     Inst.addOperand(MCOperand::createReg(0));
1422   } else
1423     Inst.addOperand(MCOperand::createReg(ARM::CPSR));
1424   return S;
1425 }
1426 
1427 static DecodeStatus DecodeCCOutOperand(MCInst &Inst, unsigned Val,
1428                                uint64_t Address, const void *Decoder) {
1429   if (Val)
1430     Inst.addOperand(MCOperand::createReg(ARM::CPSR));
1431   else
1432     Inst.addOperand(MCOperand::createReg(0));
1433   return MCDisassembler::Success;
1434 }
1435 
1436 static DecodeStatus DecodeSORegImmOperand(MCInst &Inst, unsigned Val,
1437                                uint64_t Address, const void *Decoder) {
1438   DecodeStatus S = MCDisassembler::Success;
1439 
1440   unsigned Rm = fieldFromInstruction(Val, 0, 4);
1441   unsigned type = fieldFromInstruction(Val, 5, 2);
1442   unsigned imm = fieldFromInstruction(Val, 7, 5);
1443 
1444   // Register-immediate
1445   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, 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   if (Shift == ARM_AM::ror && imm == 0)
1465     Shift = ARM_AM::rrx;
1466 
1467   unsigned Op = Shift | (imm << 3);
1468   Inst.addOperand(MCOperand::createImm(Op));
1469 
1470   return S;
1471 }
1472 
1473 static DecodeStatus DecodeSORegRegOperand(MCInst &Inst, unsigned Val,
1474                                uint64_t Address, const void *Decoder) {
1475   DecodeStatus S = MCDisassembler::Success;
1476 
1477   unsigned Rm = fieldFromInstruction(Val, 0, 4);
1478   unsigned type = fieldFromInstruction(Val, 5, 2);
1479   unsigned Rs = fieldFromInstruction(Val, 8, 4);
1480 
1481   // Register-register
1482   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1483     return MCDisassembler::Fail;
1484   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rs, Address, Decoder)))
1485     return MCDisassembler::Fail;
1486 
1487   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1488   switch (type) {
1489     case 0:
1490       Shift = ARM_AM::lsl;
1491       break;
1492     case 1:
1493       Shift = ARM_AM::lsr;
1494       break;
1495     case 2:
1496       Shift = ARM_AM::asr;
1497       break;
1498     case 3:
1499       Shift = ARM_AM::ror;
1500       break;
1501   }
1502 
1503   Inst.addOperand(MCOperand::createImm(Shift));
1504 
1505   return S;
1506 }
1507 
1508 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Val,
1509                                  uint64_t Address, const void *Decoder) {
1510   DecodeStatus S = MCDisassembler::Success;
1511 
1512   bool NeedDisjointWriteback = false;
1513   unsigned WritebackReg = 0;
1514   bool CLRM = false;
1515   switch (Inst.getOpcode()) {
1516   default:
1517     break;
1518   case ARM::LDMIA_UPD:
1519   case ARM::LDMDB_UPD:
1520   case ARM::LDMIB_UPD:
1521   case ARM::LDMDA_UPD:
1522   case ARM::t2LDMIA_UPD:
1523   case ARM::t2LDMDB_UPD:
1524   case ARM::t2STMIA_UPD:
1525   case ARM::t2STMDB_UPD:
1526     NeedDisjointWriteback = true;
1527     WritebackReg = Inst.getOperand(0).getReg();
1528     break;
1529   case ARM::t2CLRM:
1530     CLRM = true;
1531     break;
1532   }
1533 
1534   // Empty register lists are not allowed.
1535   if (Val == 0) return MCDisassembler::Fail;
1536   for (unsigned i = 0; i < 16; ++i) {
1537     if (Val & (1 << i)) {
1538       if (CLRM) {
1539         if (!Check(S, DecodeCLRMGPRRegisterClass(Inst, i, Address, Decoder))) {
1540           return MCDisassembler::Fail;
1541         }
1542       } else {
1543         if (!Check(S, DecodeGPRRegisterClass(Inst, i, Address, Decoder)))
1544           return MCDisassembler::Fail;
1545         // Writeback not allowed if Rn is in the target list.
1546         if (NeedDisjointWriteback && WritebackReg == Inst.end()[-1].getReg())
1547           Check(S, MCDisassembler::SoftFail);
1548       }
1549     }
1550   }
1551 
1552   return S;
1553 }
1554 
1555 static DecodeStatus DecodeSPRRegListOperand(MCInst &Inst, unsigned Val,
1556                                  uint64_t Address, const void *Decoder) {
1557   DecodeStatus S = MCDisassembler::Success;
1558 
1559   unsigned Vd = fieldFromInstruction(Val, 8, 5);
1560   unsigned regs = fieldFromInstruction(Val, 0, 8);
1561 
1562   // In case of unpredictable encoding, tweak the operands.
1563   if (regs == 0 || (Vd + regs) > 32) {
1564     regs = Vd + regs > 32 ? 32 - Vd : regs;
1565     regs = std::max( 1u, regs);
1566     S = MCDisassembler::SoftFail;
1567   }
1568 
1569   if (!Check(S, DecodeSPRRegisterClass(Inst, Vd, Address, Decoder)))
1570     return MCDisassembler::Fail;
1571   for (unsigned i = 0; i < (regs - 1); ++i) {
1572     if (!Check(S, DecodeSPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1573       return MCDisassembler::Fail;
1574   }
1575 
1576   return S;
1577 }
1578 
1579 static DecodeStatus DecodeDPRRegListOperand(MCInst &Inst, unsigned Val,
1580                                  uint64_t Address, const void *Decoder) {
1581   DecodeStatus S = MCDisassembler::Success;
1582 
1583   unsigned Vd = fieldFromInstruction(Val, 8, 5);
1584   unsigned regs = fieldFromInstruction(Val, 1, 7);
1585 
1586   // In case of unpredictable encoding, tweak the operands.
1587   if (regs == 0 || regs > 16 || (Vd + regs) > 32) {
1588     regs = Vd + regs > 32 ? 32 - Vd : regs;
1589     regs = std::max( 1u, regs);
1590     regs = std::min(16u, regs);
1591     S = MCDisassembler::SoftFail;
1592   }
1593 
1594   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
1595       return MCDisassembler::Fail;
1596   for (unsigned i = 0; i < (regs - 1); ++i) {
1597     if (!Check(S, DecodeDPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1598       return MCDisassembler::Fail;
1599   }
1600 
1601   return S;
1602 }
1603 
1604 static DecodeStatus DecodeBitfieldMaskOperand(MCInst &Inst, unsigned Val,
1605                                       uint64_t Address, const void *Decoder) {
1606   // This operand encodes a mask of contiguous zeros between a specified MSB
1607   // and LSB.  To decode it, we create the mask of all bits MSB-and-lower,
1608   // the mask of all bits LSB-and-lower, and then xor them to create
1609   // the mask of that's all ones on [msb, lsb].  Finally we not it to
1610   // create the final mask.
1611   unsigned msb = fieldFromInstruction(Val, 5, 5);
1612   unsigned lsb = fieldFromInstruction(Val, 0, 5);
1613 
1614   DecodeStatus S = MCDisassembler::Success;
1615   if (lsb > msb) {
1616     Check(S, MCDisassembler::SoftFail);
1617     // The check above will cause the warning for the "potentially undefined
1618     // instruction encoding" but we can't build a bad MCOperand value here
1619     // with a lsb > msb or else printing the MCInst will cause a crash.
1620     lsb = msb;
1621   }
1622 
1623   uint32_t msb_mask = 0xFFFFFFFF;
1624   if (msb != 31) msb_mask = (1U << (msb+1)) - 1;
1625   uint32_t lsb_mask = (1U << lsb) - 1;
1626 
1627   Inst.addOperand(MCOperand::createImm(~(msb_mask ^ lsb_mask)));
1628   return S;
1629 }
1630 
1631 static DecodeStatus DecodeCopMemInstruction(MCInst &Inst, unsigned Insn,
1632                                   uint64_t Address, const void *Decoder) {
1633   DecodeStatus S = MCDisassembler::Success;
1634 
1635   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1636   unsigned CRd = fieldFromInstruction(Insn, 12, 4);
1637   unsigned coproc = fieldFromInstruction(Insn, 8, 4);
1638   unsigned imm = fieldFromInstruction(Insn, 0, 8);
1639   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1640   unsigned U = fieldFromInstruction(Insn, 23, 1);
1641   const FeatureBitset &featureBits =
1642     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1643 
1644   switch (Inst.getOpcode()) {
1645     case ARM::LDC_OFFSET:
1646     case ARM::LDC_PRE:
1647     case ARM::LDC_POST:
1648     case ARM::LDC_OPTION:
1649     case ARM::LDCL_OFFSET:
1650     case ARM::LDCL_PRE:
1651     case ARM::LDCL_POST:
1652     case ARM::LDCL_OPTION:
1653     case ARM::STC_OFFSET:
1654     case ARM::STC_PRE:
1655     case ARM::STC_POST:
1656     case ARM::STC_OPTION:
1657     case ARM::STCL_OFFSET:
1658     case ARM::STCL_PRE:
1659     case ARM::STCL_POST:
1660     case ARM::STCL_OPTION:
1661     case ARM::t2LDC_OFFSET:
1662     case ARM::t2LDC_PRE:
1663     case ARM::t2LDC_POST:
1664     case ARM::t2LDC_OPTION:
1665     case ARM::t2LDCL_OFFSET:
1666     case ARM::t2LDCL_PRE:
1667     case ARM::t2LDCL_POST:
1668     case ARM::t2LDCL_OPTION:
1669     case ARM::t2STC_OFFSET:
1670     case ARM::t2STC_PRE:
1671     case ARM::t2STC_POST:
1672     case ARM::t2STC_OPTION:
1673     case ARM::t2STCL_OFFSET:
1674     case ARM::t2STCL_PRE:
1675     case ARM::t2STCL_POST:
1676     case ARM::t2STCL_OPTION:
1677     case ARM::t2LDC2_OFFSET:
1678     case ARM::t2LDC2L_OFFSET:
1679     case ARM::t2LDC2_PRE:
1680     case ARM::t2LDC2L_PRE:
1681     case ARM::t2STC2_OFFSET:
1682     case ARM::t2STC2L_OFFSET:
1683     case ARM::t2STC2_PRE:
1684     case ARM::t2STC2L_PRE:
1685     case ARM::LDC2_OFFSET:
1686     case ARM::LDC2L_OFFSET:
1687     case ARM::LDC2_PRE:
1688     case ARM::LDC2L_PRE:
1689     case ARM::STC2_OFFSET:
1690     case ARM::STC2L_OFFSET:
1691     case ARM::STC2_PRE:
1692     case ARM::STC2L_PRE:
1693     case ARM::t2LDC2_OPTION:
1694     case ARM::t2STC2_OPTION:
1695     case ARM::t2LDC2_POST:
1696     case ARM::t2LDC2L_POST:
1697     case ARM::t2STC2_POST:
1698     case ARM::t2STC2L_POST:
1699     case ARM::LDC2_POST:
1700     case ARM::LDC2L_POST:
1701     case ARM::STC2_POST:
1702     case ARM::STC2L_POST:
1703       if (coproc == 0xA || coproc == 0xB ||
1704           (featureBits[ARM::HasV8_1MMainlineOps] &&
1705            (coproc == 0x8 || coproc == 0x9 || coproc == 0xA || coproc == 0xB ||
1706             coproc == 0xE || coproc == 0xF)))
1707         return MCDisassembler::Fail;
1708       break;
1709     default:
1710       break;
1711   }
1712 
1713   if (featureBits[ARM::HasV8Ops] && (coproc != 14))
1714     return MCDisassembler::Fail;
1715 
1716   Inst.addOperand(MCOperand::createImm(coproc));
1717   Inst.addOperand(MCOperand::createImm(CRd));
1718   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1719     return MCDisassembler::Fail;
1720 
1721   switch (Inst.getOpcode()) {
1722     case ARM::t2LDC2_OFFSET:
1723     case ARM::t2LDC2L_OFFSET:
1724     case ARM::t2LDC2_PRE:
1725     case ARM::t2LDC2L_PRE:
1726     case ARM::t2STC2_OFFSET:
1727     case ARM::t2STC2L_OFFSET:
1728     case ARM::t2STC2_PRE:
1729     case ARM::t2STC2L_PRE:
1730     case ARM::LDC2_OFFSET:
1731     case ARM::LDC2L_OFFSET:
1732     case ARM::LDC2_PRE:
1733     case ARM::LDC2L_PRE:
1734     case ARM::STC2_OFFSET:
1735     case ARM::STC2L_OFFSET:
1736     case ARM::STC2_PRE:
1737     case ARM::STC2L_PRE:
1738     case ARM::t2LDC_OFFSET:
1739     case ARM::t2LDCL_OFFSET:
1740     case ARM::t2LDC_PRE:
1741     case ARM::t2LDCL_PRE:
1742     case ARM::t2STC_OFFSET:
1743     case ARM::t2STCL_OFFSET:
1744     case ARM::t2STC_PRE:
1745     case ARM::t2STCL_PRE:
1746     case ARM::LDC_OFFSET:
1747     case ARM::LDCL_OFFSET:
1748     case ARM::LDC_PRE:
1749     case ARM::LDCL_PRE:
1750     case ARM::STC_OFFSET:
1751     case ARM::STCL_OFFSET:
1752     case ARM::STC_PRE:
1753     case ARM::STCL_PRE:
1754       imm = ARM_AM::getAM5Opc(U ? ARM_AM::add : ARM_AM::sub, imm);
1755       Inst.addOperand(MCOperand::createImm(imm));
1756       break;
1757     case ARM::t2LDC2_POST:
1758     case ARM::t2LDC2L_POST:
1759     case ARM::t2STC2_POST:
1760     case ARM::t2STC2L_POST:
1761     case ARM::LDC2_POST:
1762     case ARM::LDC2L_POST:
1763     case ARM::STC2_POST:
1764     case ARM::STC2L_POST:
1765     case ARM::t2LDC_POST:
1766     case ARM::t2LDCL_POST:
1767     case ARM::t2STC_POST:
1768     case ARM::t2STCL_POST:
1769     case ARM::LDC_POST:
1770     case ARM::LDCL_POST:
1771     case ARM::STC_POST:
1772     case ARM::STCL_POST:
1773       imm |= U << 8;
1774       LLVM_FALLTHROUGH;
1775     default:
1776       // The 'option' variant doesn't encode 'U' in the immediate since
1777       // the immediate is unsigned [0,255].
1778       Inst.addOperand(MCOperand::createImm(imm));
1779       break;
1780   }
1781 
1782   switch (Inst.getOpcode()) {
1783     case ARM::LDC_OFFSET:
1784     case ARM::LDC_PRE:
1785     case ARM::LDC_POST:
1786     case ARM::LDC_OPTION:
1787     case ARM::LDCL_OFFSET:
1788     case ARM::LDCL_PRE:
1789     case ARM::LDCL_POST:
1790     case ARM::LDCL_OPTION:
1791     case ARM::STC_OFFSET:
1792     case ARM::STC_PRE:
1793     case ARM::STC_POST:
1794     case ARM::STC_OPTION:
1795     case ARM::STCL_OFFSET:
1796     case ARM::STCL_PRE:
1797     case ARM::STCL_POST:
1798     case ARM::STCL_OPTION:
1799       if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1800         return MCDisassembler::Fail;
1801       break;
1802     default:
1803       break;
1804   }
1805 
1806   return S;
1807 }
1808 
1809 static DecodeStatus
1810 DecodeAddrMode2IdxInstruction(MCInst &Inst, unsigned Insn,
1811                               uint64_t Address, const void *Decoder) {
1812   DecodeStatus S = MCDisassembler::Success;
1813 
1814   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1815   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
1816   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
1817   unsigned imm = fieldFromInstruction(Insn, 0, 12);
1818   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1819   unsigned reg = fieldFromInstruction(Insn, 25, 1);
1820   unsigned P = fieldFromInstruction(Insn, 24, 1);
1821   unsigned W = fieldFromInstruction(Insn, 21, 1);
1822 
1823   // On stores, the writeback operand precedes Rt.
1824   switch (Inst.getOpcode()) {
1825     case ARM::STR_POST_IMM:
1826     case ARM::STR_POST_REG:
1827     case ARM::STRB_POST_IMM:
1828     case ARM::STRB_POST_REG:
1829     case ARM::STRT_POST_REG:
1830     case ARM::STRT_POST_IMM:
1831     case ARM::STRBT_POST_REG:
1832     case ARM::STRBT_POST_IMM:
1833       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1834         return MCDisassembler::Fail;
1835       break;
1836     default:
1837       break;
1838   }
1839 
1840   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
1841     return MCDisassembler::Fail;
1842 
1843   // On loads, the writeback operand comes after Rt.
1844   switch (Inst.getOpcode()) {
1845     case ARM::LDR_POST_IMM:
1846     case ARM::LDR_POST_REG:
1847     case ARM::LDRB_POST_IMM:
1848     case ARM::LDRB_POST_REG:
1849     case ARM::LDRBT_POST_REG:
1850     case ARM::LDRBT_POST_IMM:
1851     case ARM::LDRT_POST_REG:
1852     case ARM::LDRT_POST_IMM:
1853       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1854         return MCDisassembler::Fail;
1855       break;
1856     default:
1857       break;
1858   }
1859 
1860   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1861     return MCDisassembler::Fail;
1862 
1863   ARM_AM::AddrOpc Op = ARM_AM::add;
1864   if (!fieldFromInstruction(Insn, 23, 1))
1865     Op = ARM_AM::sub;
1866 
1867   bool writeback = (P == 0) || (W == 1);
1868   unsigned idx_mode = 0;
1869   if (P && writeback)
1870     idx_mode = ARMII::IndexModePre;
1871   else if (!P && writeback)
1872     idx_mode = ARMII::IndexModePost;
1873 
1874   if (writeback && (Rn == 15 || Rn == Rt))
1875     S = MCDisassembler::SoftFail; // UNPREDICTABLE
1876 
1877   if (reg) {
1878     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1879       return MCDisassembler::Fail;
1880     ARM_AM::ShiftOpc Opc = ARM_AM::lsl;
1881     switch( fieldFromInstruction(Insn, 5, 2)) {
1882       case 0:
1883         Opc = ARM_AM::lsl;
1884         break;
1885       case 1:
1886         Opc = ARM_AM::lsr;
1887         break;
1888       case 2:
1889         Opc = ARM_AM::asr;
1890         break;
1891       case 3:
1892         Opc = ARM_AM::ror;
1893         break;
1894       default:
1895         return MCDisassembler::Fail;
1896     }
1897     unsigned amt = fieldFromInstruction(Insn, 7, 5);
1898     if (Opc == ARM_AM::ror && amt == 0)
1899       Opc = ARM_AM::rrx;
1900     unsigned imm = ARM_AM::getAM2Opc(Op, amt, Opc, idx_mode);
1901 
1902     Inst.addOperand(MCOperand::createImm(imm));
1903   } else {
1904     Inst.addOperand(MCOperand::createReg(0));
1905     unsigned tmp = ARM_AM::getAM2Opc(Op, imm, ARM_AM::lsl, idx_mode);
1906     Inst.addOperand(MCOperand::createImm(tmp));
1907   }
1908 
1909   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1910     return MCDisassembler::Fail;
1911 
1912   return S;
1913 }
1914 
1915 static DecodeStatus DecodeSORegMemOperand(MCInst &Inst, unsigned Val,
1916                                   uint64_t Address, const void *Decoder) {
1917   DecodeStatus S = MCDisassembler::Success;
1918 
1919   unsigned Rn = fieldFromInstruction(Val, 13, 4);
1920   unsigned Rm = fieldFromInstruction(Val,  0, 4);
1921   unsigned type = fieldFromInstruction(Val, 5, 2);
1922   unsigned imm = fieldFromInstruction(Val, 7, 5);
1923   unsigned U = fieldFromInstruction(Val, 12, 1);
1924 
1925   ARM_AM::ShiftOpc ShOp = ARM_AM::lsl;
1926   switch (type) {
1927     case 0:
1928       ShOp = ARM_AM::lsl;
1929       break;
1930     case 1:
1931       ShOp = ARM_AM::lsr;
1932       break;
1933     case 2:
1934       ShOp = ARM_AM::asr;
1935       break;
1936     case 3:
1937       ShOp = ARM_AM::ror;
1938       break;
1939   }
1940 
1941   if (ShOp == ARM_AM::ror && imm == 0)
1942     ShOp = ARM_AM::rrx;
1943 
1944   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1945     return MCDisassembler::Fail;
1946   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1947     return MCDisassembler::Fail;
1948   unsigned shift;
1949   if (U)
1950     shift = ARM_AM::getAM2Opc(ARM_AM::add, imm, ShOp);
1951   else
1952     shift = ARM_AM::getAM2Opc(ARM_AM::sub, imm, ShOp);
1953   Inst.addOperand(MCOperand::createImm(shift));
1954 
1955   return S;
1956 }
1957 
1958 static DecodeStatus
1959 DecodeAddrMode3Instruction(MCInst &Inst, unsigned Insn,
1960                            uint64_t Address, const void *Decoder) {
1961   DecodeStatus S = MCDisassembler::Success;
1962 
1963   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
1964   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1965   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
1966   unsigned type = fieldFromInstruction(Insn, 22, 1);
1967   unsigned imm = fieldFromInstruction(Insn, 8, 4);
1968   unsigned U = ((~fieldFromInstruction(Insn, 23, 1)) & 1) << 8;
1969   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1970   unsigned W = fieldFromInstruction(Insn, 21, 1);
1971   unsigned P = fieldFromInstruction(Insn, 24, 1);
1972   unsigned Rt2 = Rt + 1;
1973 
1974   bool writeback = (W == 1) | (P == 0);
1975 
1976   // For {LD,ST}RD, Rt must be even, else undefined.
1977   switch (Inst.getOpcode()) {
1978     case ARM::STRD:
1979     case ARM::STRD_PRE:
1980     case ARM::STRD_POST:
1981     case ARM::LDRD:
1982     case ARM::LDRD_PRE:
1983     case ARM::LDRD_POST:
1984       if (Rt & 0x1) S = MCDisassembler::SoftFail;
1985       break;
1986     default:
1987       break;
1988   }
1989   switch (Inst.getOpcode()) {
1990     case ARM::STRD:
1991     case ARM::STRD_PRE:
1992     case ARM::STRD_POST:
1993       if (P == 0 && W == 1)
1994         S = MCDisassembler::SoftFail;
1995 
1996       if (writeback && (Rn == 15 || Rn == Rt || Rn == Rt2))
1997         S = MCDisassembler::SoftFail;
1998       if (type && Rm == 15)
1999         S = MCDisassembler::SoftFail;
2000       if (Rt2 == 15)
2001         S = MCDisassembler::SoftFail;
2002       if (!type && fieldFromInstruction(Insn, 8, 4))
2003         S = MCDisassembler::SoftFail;
2004       break;
2005     case ARM::STRH:
2006     case ARM::STRH_PRE:
2007     case ARM::STRH_POST:
2008       if (Rt == 15)
2009         S = MCDisassembler::SoftFail;
2010       if (writeback && (Rn == 15 || Rn == Rt))
2011         S = MCDisassembler::SoftFail;
2012       if (!type && Rm == 15)
2013         S = MCDisassembler::SoftFail;
2014       break;
2015     case ARM::LDRD:
2016     case ARM::LDRD_PRE:
2017     case ARM::LDRD_POST:
2018       if (type && Rn == 15) {
2019         if (Rt2 == 15)
2020           S = MCDisassembler::SoftFail;
2021         break;
2022       }
2023       if (P == 0 && W == 1)
2024         S = MCDisassembler::SoftFail;
2025       if (!type && (Rt2 == 15 || Rm == 15 || Rm == Rt || Rm == Rt2))
2026         S = MCDisassembler::SoftFail;
2027       if (!type && writeback && Rn == 15)
2028         S = MCDisassembler::SoftFail;
2029       if (writeback && (Rn == Rt || Rn == Rt2))
2030         S = MCDisassembler::SoftFail;
2031       break;
2032     case ARM::LDRH:
2033     case ARM::LDRH_PRE:
2034     case ARM::LDRH_POST:
2035       if (type && Rn == 15) {
2036         if (Rt == 15)
2037           S = MCDisassembler::SoftFail;
2038         break;
2039       }
2040       if (Rt == 15)
2041         S = MCDisassembler::SoftFail;
2042       if (!type && Rm == 15)
2043         S = MCDisassembler::SoftFail;
2044       if (!type && writeback && (Rn == 15 || Rn == Rt))
2045         S = MCDisassembler::SoftFail;
2046       break;
2047     case ARM::LDRSH:
2048     case ARM::LDRSH_PRE:
2049     case ARM::LDRSH_POST:
2050     case ARM::LDRSB:
2051     case ARM::LDRSB_PRE:
2052     case ARM::LDRSB_POST:
2053       if (type && Rn == 15) {
2054         if (Rt == 15)
2055           S = MCDisassembler::SoftFail;
2056         break;
2057       }
2058       if (type && (Rt == 15 || (writeback && Rn == Rt)))
2059         S = MCDisassembler::SoftFail;
2060       if (!type && (Rt == 15 || Rm == 15))
2061         S = MCDisassembler::SoftFail;
2062       if (!type && writeback && (Rn == 15 || Rn == Rt))
2063         S = MCDisassembler::SoftFail;
2064       break;
2065     default:
2066       break;
2067   }
2068 
2069   if (writeback) { // Writeback
2070     if (P)
2071       U |= ARMII::IndexModePre << 9;
2072     else
2073       U |= ARMII::IndexModePost << 9;
2074 
2075     // On stores, the writeback operand precedes Rt.
2076     switch (Inst.getOpcode()) {
2077     case ARM::STRD:
2078     case ARM::STRD_PRE:
2079     case ARM::STRD_POST:
2080     case ARM::STRH:
2081     case ARM::STRH_PRE:
2082     case ARM::STRH_POST:
2083       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2084         return MCDisassembler::Fail;
2085       break;
2086     default:
2087       break;
2088     }
2089   }
2090 
2091   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
2092     return MCDisassembler::Fail;
2093   switch (Inst.getOpcode()) {
2094     case ARM::STRD:
2095     case ARM::STRD_PRE:
2096     case ARM::STRD_POST:
2097     case ARM::LDRD:
2098     case ARM::LDRD_PRE:
2099     case ARM::LDRD_POST:
2100       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder)))
2101         return MCDisassembler::Fail;
2102       break;
2103     default:
2104       break;
2105   }
2106 
2107   if (writeback) {
2108     // On loads, the writeback operand comes after Rt.
2109     switch (Inst.getOpcode()) {
2110     case ARM::LDRD:
2111     case ARM::LDRD_PRE:
2112     case ARM::LDRD_POST:
2113     case ARM::LDRH:
2114     case ARM::LDRH_PRE:
2115     case ARM::LDRH_POST:
2116     case ARM::LDRSH:
2117     case ARM::LDRSH_PRE:
2118     case ARM::LDRSH_POST:
2119     case ARM::LDRSB:
2120     case ARM::LDRSB_PRE:
2121     case ARM::LDRSB_POST:
2122     case ARM::LDRHTr:
2123     case ARM::LDRSBTr:
2124       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2125         return MCDisassembler::Fail;
2126       break;
2127     default:
2128       break;
2129     }
2130   }
2131 
2132   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2133     return MCDisassembler::Fail;
2134 
2135   if (type) {
2136     Inst.addOperand(MCOperand::createReg(0));
2137     Inst.addOperand(MCOperand::createImm(U | (imm << 4) | Rm));
2138   } else {
2139     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2140     return MCDisassembler::Fail;
2141     Inst.addOperand(MCOperand::createImm(U));
2142   }
2143 
2144   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2145     return MCDisassembler::Fail;
2146 
2147   return S;
2148 }
2149 
2150 static DecodeStatus DecodeRFEInstruction(MCInst &Inst, unsigned Insn,
2151                                  uint64_t Address, const void *Decoder) {
2152   DecodeStatus S = MCDisassembler::Success;
2153 
2154   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2155   unsigned mode = fieldFromInstruction(Insn, 23, 2);
2156 
2157   switch (mode) {
2158     case 0:
2159       mode = ARM_AM::da;
2160       break;
2161     case 1:
2162       mode = ARM_AM::ia;
2163       break;
2164     case 2:
2165       mode = ARM_AM::db;
2166       break;
2167     case 3:
2168       mode = ARM_AM::ib;
2169       break;
2170   }
2171 
2172   Inst.addOperand(MCOperand::createImm(mode));
2173   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2174     return MCDisassembler::Fail;
2175 
2176   return S;
2177 }
2178 
2179 static DecodeStatus DecodeQADDInstruction(MCInst &Inst, unsigned Insn,
2180                                uint64_t Address, const void *Decoder) {
2181   DecodeStatus S = MCDisassembler::Success;
2182 
2183   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2184   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2185   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2186   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2187 
2188   if (pred == 0xF)
2189     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
2190 
2191   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2192     return MCDisassembler::Fail;
2193   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
2194     return MCDisassembler::Fail;
2195   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
2196     return MCDisassembler::Fail;
2197   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2198     return MCDisassembler::Fail;
2199   return S;
2200 }
2201 
2202 static DecodeStatus DecodeMemMultipleWritebackInstruction(MCInst &Inst,
2203                                   unsigned Insn,
2204                                   uint64_t Address, const void *Decoder) {
2205   DecodeStatus S = MCDisassembler::Success;
2206 
2207   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2208   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2209   unsigned reglist = fieldFromInstruction(Insn, 0, 16);
2210 
2211   if (pred == 0xF) {
2212     // Ambiguous with RFE and SRS
2213     switch (Inst.getOpcode()) {
2214       case ARM::LDMDA:
2215         Inst.setOpcode(ARM::RFEDA);
2216         break;
2217       case ARM::LDMDA_UPD:
2218         Inst.setOpcode(ARM::RFEDA_UPD);
2219         break;
2220       case ARM::LDMDB:
2221         Inst.setOpcode(ARM::RFEDB);
2222         break;
2223       case ARM::LDMDB_UPD:
2224         Inst.setOpcode(ARM::RFEDB_UPD);
2225         break;
2226       case ARM::LDMIA:
2227         Inst.setOpcode(ARM::RFEIA);
2228         break;
2229       case ARM::LDMIA_UPD:
2230         Inst.setOpcode(ARM::RFEIA_UPD);
2231         break;
2232       case ARM::LDMIB:
2233         Inst.setOpcode(ARM::RFEIB);
2234         break;
2235       case ARM::LDMIB_UPD:
2236         Inst.setOpcode(ARM::RFEIB_UPD);
2237         break;
2238       case ARM::STMDA:
2239         Inst.setOpcode(ARM::SRSDA);
2240         break;
2241       case ARM::STMDA_UPD:
2242         Inst.setOpcode(ARM::SRSDA_UPD);
2243         break;
2244       case ARM::STMDB:
2245         Inst.setOpcode(ARM::SRSDB);
2246         break;
2247       case ARM::STMDB_UPD:
2248         Inst.setOpcode(ARM::SRSDB_UPD);
2249         break;
2250       case ARM::STMIA:
2251         Inst.setOpcode(ARM::SRSIA);
2252         break;
2253       case ARM::STMIA_UPD:
2254         Inst.setOpcode(ARM::SRSIA_UPD);
2255         break;
2256       case ARM::STMIB:
2257         Inst.setOpcode(ARM::SRSIB);
2258         break;
2259       case ARM::STMIB_UPD:
2260         Inst.setOpcode(ARM::SRSIB_UPD);
2261         break;
2262       default:
2263         return MCDisassembler::Fail;
2264     }
2265 
2266     // For stores (which become SRS's, the only operand is the mode.
2267     if (fieldFromInstruction(Insn, 20, 1) == 0) {
2268       // Check SRS encoding constraints
2269       if (!(fieldFromInstruction(Insn, 22, 1) == 1 &&
2270             fieldFromInstruction(Insn, 20, 1) == 0))
2271         return MCDisassembler::Fail;
2272 
2273       Inst.addOperand(
2274           MCOperand::createImm(fieldFromInstruction(Insn, 0, 4)));
2275       return S;
2276     }
2277 
2278     return DecodeRFEInstruction(Inst, Insn, Address, Decoder);
2279   }
2280 
2281   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2282     return MCDisassembler::Fail;
2283   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2284     return MCDisassembler::Fail; // Tied
2285   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2286     return MCDisassembler::Fail;
2287   if (!Check(S, DecodeRegListOperand(Inst, reglist, Address, Decoder)))
2288     return MCDisassembler::Fail;
2289 
2290   return S;
2291 }
2292 
2293 // Check for UNPREDICTABLE predicated ESB instruction
2294 static DecodeStatus DecodeHINTInstruction(MCInst &Inst, unsigned Insn,
2295                                  uint64_t Address, const void *Decoder) {
2296   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2297   unsigned imm8 = fieldFromInstruction(Insn, 0, 8);
2298   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
2299   const FeatureBitset &FeatureBits = Dis->getSubtargetInfo().getFeatureBits();
2300 
2301   DecodeStatus S = MCDisassembler::Success;
2302 
2303   Inst.addOperand(MCOperand::createImm(imm8));
2304 
2305   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2306     return MCDisassembler::Fail;
2307 
2308   // ESB is unpredictable if pred != AL. Without the RAS extension, it is a NOP,
2309   // so all predicates should be allowed.
2310   if (imm8 == 0x10 && pred != 0xe && ((FeatureBits[ARM::FeatureRAS]) != 0))
2311     S = MCDisassembler::SoftFail;
2312 
2313   return S;
2314 }
2315 
2316 static DecodeStatus DecodeCPSInstruction(MCInst &Inst, unsigned Insn,
2317                                  uint64_t Address, const void *Decoder) {
2318   unsigned imod = fieldFromInstruction(Insn, 18, 2);
2319   unsigned M = fieldFromInstruction(Insn, 17, 1);
2320   unsigned iflags = fieldFromInstruction(Insn, 6, 3);
2321   unsigned mode = fieldFromInstruction(Insn, 0, 5);
2322 
2323   DecodeStatus S = MCDisassembler::Success;
2324 
2325   // This decoder is called from multiple location that do not check
2326   // the full encoding is valid before they do.
2327   if (fieldFromInstruction(Insn, 5, 1) != 0 ||
2328       fieldFromInstruction(Insn, 16, 1) != 0 ||
2329       fieldFromInstruction(Insn, 20, 8) != 0x10)
2330     return MCDisassembler::Fail;
2331 
2332   // imod == '01' --> UNPREDICTABLE
2333   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
2334   // return failure here.  The '01' imod value is unprintable, so there's
2335   // nothing useful we could do even if we returned UNPREDICTABLE.
2336 
2337   if (imod == 1) return MCDisassembler::Fail;
2338 
2339   if (imod && M) {
2340     Inst.setOpcode(ARM::CPS3p);
2341     Inst.addOperand(MCOperand::createImm(imod));
2342     Inst.addOperand(MCOperand::createImm(iflags));
2343     Inst.addOperand(MCOperand::createImm(mode));
2344   } else if (imod && !M) {
2345     Inst.setOpcode(ARM::CPS2p);
2346     Inst.addOperand(MCOperand::createImm(imod));
2347     Inst.addOperand(MCOperand::createImm(iflags));
2348     if (mode) S = MCDisassembler::SoftFail;
2349   } else if (!imod && M) {
2350     Inst.setOpcode(ARM::CPS1p);
2351     Inst.addOperand(MCOperand::createImm(mode));
2352     if (iflags) S = MCDisassembler::SoftFail;
2353   } else {
2354     // imod == '00' && M == '0' --> UNPREDICTABLE
2355     Inst.setOpcode(ARM::CPS1p);
2356     Inst.addOperand(MCOperand::createImm(mode));
2357     S = MCDisassembler::SoftFail;
2358   }
2359 
2360   return S;
2361 }
2362 
2363 static DecodeStatus DecodeT2CPSInstruction(MCInst &Inst, unsigned Insn,
2364                                  uint64_t Address, const void *Decoder) {
2365   unsigned imod = fieldFromInstruction(Insn, 9, 2);
2366   unsigned M = fieldFromInstruction(Insn, 8, 1);
2367   unsigned iflags = fieldFromInstruction(Insn, 5, 3);
2368   unsigned mode = fieldFromInstruction(Insn, 0, 5);
2369 
2370   DecodeStatus S = MCDisassembler::Success;
2371 
2372   // imod == '01' --> UNPREDICTABLE
2373   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
2374   // return failure here.  The '01' imod value is unprintable, so there's
2375   // nothing useful we could do even if we returned UNPREDICTABLE.
2376 
2377   if (imod == 1) return MCDisassembler::Fail;
2378 
2379   if (imod && M) {
2380     Inst.setOpcode(ARM::t2CPS3p);
2381     Inst.addOperand(MCOperand::createImm(imod));
2382     Inst.addOperand(MCOperand::createImm(iflags));
2383     Inst.addOperand(MCOperand::createImm(mode));
2384   } else if (imod && !M) {
2385     Inst.setOpcode(ARM::t2CPS2p);
2386     Inst.addOperand(MCOperand::createImm(imod));
2387     Inst.addOperand(MCOperand::createImm(iflags));
2388     if (mode) S = MCDisassembler::SoftFail;
2389   } else if (!imod && M) {
2390     Inst.setOpcode(ARM::t2CPS1p);
2391     Inst.addOperand(MCOperand::createImm(mode));
2392     if (iflags) S = MCDisassembler::SoftFail;
2393   } else {
2394     // imod == '00' && M == '0' --> this is a HINT instruction
2395     int imm = fieldFromInstruction(Insn, 0, 8);
2396     // HINT are defined only for immediate in [0..4]
2397     if(imm > 4) return MCDisassembler::Fail;
2398     Inst.setOpcode(ARM::t2HINT);
2399     Inst.addOperand(MCOperand::createImm(imm));
2400   }
2401 
2402   return S;
2403 }
2404 
2405 static DecodeStatus DecodeT2MOVTWInstruction(MCInst &Inst, unsigned Insn,
2406                                  uint64_t Address, const void *Decoder) {
2407   DecodeStatus S = MCDisassembler::Success;
2408 
2409   unsigned Rd = fieldFromInstruction(Insn, 8, 4);
2410   unsigned imm = 0;
2411 
2412   imm |= (fieldFromInstruction(Insn, 0, 8) << 0);
2413   imm |= (fieldFromInstruction(Insn, 12, 3) << 8);
2414   imm |= (fieldFromInstruction(Insn, 16, 4) << 12);
2415   imm |= (fieldFromInstruction(Insn, 26, 1) << 11);
2416 
2417   if (Inst.getOpcode() == ARM::t2MOVTi16)
2418     if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
2419       return MCDisassembler::Fail;
2420   if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
2421     return MCDisassembler::Fail;
2422 
2423   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
2424     Inst.addOperand(MCOperand::createImm(imm));
2425 
2426   return S;
2427 }
2428 
2429 static DecodeStatus DecodeArmMOVTWInstruction(MCInst &Inst, unsigned Insn,
2430                                  uint64_t Address, const void *Decoder) {
2431   DecodeStatus S = MCDisassembler::Success;
2432 
2433   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2434   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2435   unsigned imm = 0;
2436 
2437   imm |= (fieldFromInstruction(Insn, 0, 12) << 0);
2438   imm |= (fieldFromInstruction(Insn, 16, 4) << 12);
2439 
2440   if (Inst.getOpcode() == ARM::MOVTi16)
2441     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2442       return MCDisassembler::Fail;
2443 
2444   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2445     return MCDisassembler::Fail;
2446 
2447   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
2448     Inst.addOperand(MCOperand::createImm(imm));
2449 
2450   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2451     return MCDisassembler::Fail;
2452 
2453   return S;
2454 }
2455 
2456 static DecodeStatus DecodeSMLAInstruction(MCInst &Inst, unsigned Insn,
2457                                  uint64_t Address, const void *Decoder) {
2458   DecodeStatus S = MCDisassembler::Success;
2459 
2460   unsigned Rd = fieldFromInstruction(Insn, 16, 4);
2461   unsigned Rn = fieldFromInstruction(Insn, 0, 4);
2462   unsigned Rm = fieldFromInstruction(Insn, 8, 4);
2463   unsigned Ra = fieldFromInstruction(Insn, 12, 4);
2464   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2465 
2466   if (pred == 0xF)
2467     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
2468 
2469   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2470     return MCDisassembler::Fail;
2471   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
2472     return MCDisassembler::Fail;
2473   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
2474     return MCDisassembler::Fail;
2475   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Ra, Address, Decoder)))
2476     return MCDisassembler::Fail;
2477 
2478   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2479     return MCDisassembler::Fail;
2480 
2481   return S;
2482 }
2483 
2484 static DecodeStatus DecodeTSTInstruction(MCInst &Inst, unsigned Insn,
2485                                   uint64_t Address, const void *Decoder) {
2486   DecodeStatus S = MCDisassembler::Success;
2487 
2488   unsigned Pred = fieldFromInstruction(Insn, 28, 4);
2489   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2490   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2491 
2492   if (Pred == 0xF)
2493     return DecodeSETPANInstruction(Inst, Insn, Address, Decoder);
2494 
2495   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2496     return MCDisassembler::Fail;
2497   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2498     return MCDisassembler::Fail;
2499   if (!Check(S, DecodePredicateOperand(Inst, Pred, Address, Decoder)))
2500     return MCDisassembler::Fail;
2501 
2502   return S;
2503 }
2504 
2505 static DecodeStatus DecodeSETPANInstruction(MCInst &Inst, unsigned Insn,
2506                                   uint64_t Address, const void *Decoder) {
2507   DecodeStatus S = MCDisassembler::Success;
2508 
2509   unsigned Imm = fieldFromInstruction(Insn, 9, 1);
2510 
2511   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
2512   const FeatureBitset &FeatureBits = Dis->getSubtargetInfo().getFeatureBits();
2513 
2514   if (!FeatureBits[ARM::HasV8_1aOps] ||
2515       !FeatureBits[ARM::HasV8Ops])
2516     return MCDisassembler::Fail;
2517 
2518   // Decoder can be called from DecodeTST, which does not check the full
2519   // encoding is valid.
2520   if (fieldFromInstruction(Insn, 20,12) != 0xf11 ||
2521       fieldFromInstruction(Insn, 4,4) != 0)
2522     return MCDisassembler::Fail;
2523   if (fieldFromInstruction(Insn, 10,10) != 0 ||
2524       fieldFromInstruction(Insn, 0,4) != 0)
2525     S = MCDisassembler::SoftFail;
2526 
2527   Inst.setOpcode(ARM::SETPAN);
2528   Inst.addOperand(MCOperand::createImm(Imm));
2529 
2530   return S;
2531 }
2532 
2533 static DecodeStatus DecodeAddrModeImm12Operand(MCInst &Inst, unsigned Val,
2534                            uint64_t Address, const void *Decoder) {
2535   DecodeStatus S = MCDisassembler::Success;
2536 
2537   unsigned add = fieldFromInstruction(Val, 12, 1);
2538   unsigned imm = fieldFromInstruction(Val, 0, 12);
2539   unsigned Rn = fieldFromInstruction(Val, 13, 4);
2540 
2541   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2542     return MCDisassembler::Fail;
2543 
2544   if (!add) imm *= -1;
2545   if (imm == 0 && !add) imm = INT32_MIN;
2546   Inst.addOperand(MCOperand::createImm(imm));
2547   if (Rn == 15)
2548     tryAddingPcLoadReferenceComment(Address, Address + imm + 8, Decoder);
2549 
2550   return S;
2551 }
2552 
2553 static DecodeStatus DecodeAddrMode5Operand(MCInst &Inst, unsigned Val,
2554                                    uint64_t Address, const void *Decoder) {
2555   DecodeStatus S = MCDisassembler::Success;
2556 
2557   unsigned Rn = fieldFromInstruction(Val, 9, 4);
2558   // U == 1 to add imm, 0 to subtract it.
2559   unsigned U = fieldFromInstruction(Val, 8, 1);
2560   unsigned imm = fieldFromInstruction(Val, 0, 8);
2561 
2562   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2563     return MCDisassembler::Fail;
2564 
2565   if (U)
2566     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5Opc(ARM_AM::add, imm)));
2567   else
2568     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5Opc(ARM_AM::sub, imm)));
2569 
2570   return S;
2571 }
2572 
2573 static DecodeStatus DecodeAddrMode5FP16Operand(MCInst &Inst, unsigned Val,
2574                                    uint64_t Address, const void *Decoder) {
2575   DecodeStatus S = MCDisassembler::Success;
2576 
2577   unsigned Rn = fieldFromInstruction(Val, 9, 4);
2578   // U == 1 to add imm, 0 to subtract it.
2579   unsigned U = fieldFromInstruction(Val, 8, 1);
2580   unsigned imm = fieldFromInstruction(Val, 0, 8);
2581 
2582   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2583     return MCDisassembler::Fail;
2584 
2585   if (U)
2586     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5FP16Opc(ARM_AM::add, imm)));
2587   else
2588     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5FP16Opc(ARM_AM::sub, imm)));
2589 
2590   return S;
2591 }
2592 
2593 static DecodeStatus DecodeAddrMode7Operand(MCInst &Inst, unsigned Val,
2594                                    uint64_t Address, const void *Decoder) {
2595   return DecodeGPRRegisterClass(Inst, Val, Address, Decoder);
2596 }
2597 
2598 static DecodeStatus
2599 DecodeT2BInstruction(MCInst &Inst, unsigned Insn,
2600                      uint64_t Address, const void *Decoder) {
2601   DecodeStatus Status = MCDisassembler::Success;
2602 
2603   // Note the J1 and J2 values are from the encoded instruction.  So here
2604   // change them to I1 and I2 values via as documented:
2605   // I1 = NOT(J1 EOR S);
2606   // I2 = NOT(J2 EOR S);
2607   // and build the imm32 with one trailing zero as documented:
2608   // imm32 = SignExtend(S:I1:I2:imm10:imm11:'0', 32);
2609   unsigned S = fieldFromInstruction(Insn, 26, 1);
2610   unsigned J1 = fieldFromInstruction(Insn, 13, 1);
2611   unsigned J2 = fieldFromInstruction(Insn, 11, 1);
2612   unsigned I1 = !(J1 ^ S);
2613   unsigned I2 = !(J2 ^ S);
2614   unsigned imm10 = fieldFromInstruction(Insn, 16, 10);
2615   unsigned imm11 = fieldFromInstruction(Insn, 0, 11);
2616   unsigned tmp = (S << 23) | (I1 << 22) | (I2 << 21) | (imm10 << 11) | imm11;
2617   int imm32 = SignExtend32<25>(tmp << 1);
2618   if (!tryAddingSymbolicOperand(Address, Address + imm32 + 4,
2619                                 true, 4, Inst, Decoder))
2620     Inst.addOperand(MCOperand::createImm(imm32));
2621 
2622   return Status;
2623 }
2624 
2625 static DecodeStatus
2626 DecodeBranchImmInstruction(MCInst &Inst, unsigned Insn,
2627                            uint64_t Address, const void *Decoder) {
2628   DecodeStatus S = MCDisassembler::Success;
2629 
2630   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2631   unsigned imm = fieldFromInstruction(Insn, 0, 24) << 2;
2632 
2633   if (pred == 0xF) {
2634     Inst.setOpcode(ARM::BLXi);
2635     imm |= fieldFromInstruction(Insn, 24, 1) << 1;
2636     if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<26>(imm) + 8,
2637                                   true, 4, Inst, Decoder))
2638     Inst.addOperand(MCOperand::createImm(SignExtend32<26>(imm)));
2639     return S;
2640   }
2641 
2642   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<26>(imm) + 8,
2643                                 true, 4, Inst, Decoder))
2644     Inst.addOperand(MCOperand::createImm(SignExtend32<26>(imm)));
2645   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2646     return MCDisassembler::Fail;
2647 
2648   return S;
2649 }
2650 
2651 static DecodeStatus DecodeAddrMode6Operand(MCInst &Inst, unsigned Val,
2652                                    uint64_t Address, const void *Decoder) {
2653   DecodeStatus S = MCDisassembler::Success;
2654 
2655   unsigned Rm = fieldFromInstruction(Val, 0, 4);
2656   unsigned align = fieldFromInstruction(Val, 4, 2);
2657 
2658   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2659     return MCDisassembler::Fail;
2660   if (!align)
2661     Inst.addOperand(MCOperand::createImm(0));
2662   else
2663     Inst.addOperand(MCOperand::createImm(4 << align));
2664 
2665   return S;
2666 }
2667 
2668 static DecodeStatus DecodeVLDInstruction(MCInst &Inst, unsigned Insn,
2669                                    uint64_t Address, const void *Decoder) {
2670   DecodeStatus S = MCDisassembler::Success;
2671 
2672   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2673   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
2674   unsigned wb = fieldFromInstruction(Insn, 16, 4);
2675   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2676   Rn |= fieldFromInstruction(Insn, 4, 2) << 4;
2677   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2678 
2679   // First output register
2680   switch (Inst.getOpcode()) {
2681   case ARM::VLD1q16: case ARM::VLD1q32: case ARM::VLD1q64: case ARM::VLD1q8:
2682   case ARM::VLD1q16wb_fixed: case ARM::VLD1q16wb_register:
2683   case ARM::VLD1q32wb_fixed: case ARM::VLD1q32wb_register:
2684   case ARM::VLD1q64wb_fixed: case ARM::VLD1q64wb_register:
2685   case ARM::VLD1q8wb_fixed: case ARM::VLD1q8wb_register:
2686   case ARM::VLD2d16: case ARM::VLD2d32: case ARM::VLD2d8:
2687   case ARM::VLD2d16wb_fixed: case ARM::VLD2d16wb_register:
2688   case ARM::VLD2d32wb_fixed: case ARM::VLD2d32wb_register:
2689   case ARM::VLD2d8wb_fixed: case ARM::VLD2d8wb_register:
2690     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
2691       return MCDisassembler::Fail;
2692     break;
2693   case ARM::VLD2b16:
2694   case ARM::VLD2b32:
2695   case ARM::VLD2b8:
2696   case ARM::VLD2b16wb_fixed:
2697   case ARM::VLD2b16wb_register:
2698   case ARM::VLD2b32wb_fixed:
2699   case ARM::VLD2b32wb_register:
2700   case ARM::VLD2b8wb_fixed:
2701   case ARM::VLD2b8wb_register:
2702     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
2703       return MCDisassembler::Fail;
2704     break;
2705   default:
2706     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2707       return MCDisassembler::Fail;
2708   }
2709 
2710   // Second output register
2711   switch (Inst.getOpcode()) {
2712     case ARM::VLD3d8:
2713     case ARM::VLD3d16:
2714     case ARM::VLD3d32:
2715     case ARM::VLD3d8_UPD:
2716     case ARM::VLD3d16_UPD:
2717     case ARM::VLD3d32_UPD:
2718     case ARM::VLD4d8:
2719     case ARM::VLD4d16:
2720     case ARM::VLD4d32:
2721     case ARM::VLD4d8_UPD:
2722     case ARM::VLD4d16_UPD:
2723     case ARM::VLD4d32_UPD:
2724       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
2725         return MCDisassembler::Fail;
2726       break;
2727     case ARM::VLD3q8:
2728     case ARM::VLD3q16:
2729     case ARM::VLD3q32:
2730     case ARM::VLD3q8_UPD:
2731     case ARM::VLD3q16_UPD:
2732     case ARM::VLD3q32_UPD:
2733     case ARM::VLD4q8:
2734     case ARM::VLD4q16:
2735     case ARM::VLD4q32:
2736     case ARM::VLD4q8_UPD:
2737     case ARM::VLD4q16_UPD:
2738     case ARM::VLD4q32_UPD:
2739       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2740         return MCDisassembler::Fail;
2741       break;
2742     default:
2743       break;
2744   }
2745 
2746   // Third output register
2747   switch(Inst.getOpcode()) {
2748     case ARM::VLD3d8:
2749     case ARM::VLD3d16:
2750     case ARM::VLD3d32:
2751     case ARM::VLD3d8_UPD:
2752     case ARM::VLD3d16_UPD:
2753     case ARM::VLD3d32_UPD:
2754     case ARM::VLD4d8:
2755     case ARM::VLD4d16:
2756     case ARM::VLD4d32:
2757     case ARM::VLD4d8_UPD:
2758     case ARM::VLD4d16_UPD:
2759     case ARM::VLD4d32_UPD:
2760       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2761         return MCDisassembler::Fail;
2762       break;
2763     case ARM::VLD3q8:
2764     case ARM::VLD3q16:
2765     case ARM::VLD3q32:
2766     case ARM::VLD3q8_UPD:
2767     case ARM::VLD3q16_UPD:
2768     case ARM::VLD3q32_UPD:
2769     case ARM::VLD4q8:
2770     case ARM::VLD4q16:
2771     case ARM::VLD4q32:
2772     case ARM::VLD4q8_UPD:
2773     case ARM::VLD4q16_UPD:
2774     case ARM::VLD4q32_UPD:
2775       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
2776         return MCDisassembler::Fail;
2777       break;
2778     default:
2779       break;
2780   }
2781 
2782   // Fourth output register
2783   switch (Inst.getOpcode()) {
2784     case ARM::VLD4d8:
2785     case ARM::VLD4d16:
2786     case ARM::VLD4d32:
2787     case ARM::VLD4d8_UPD:
2788     case ARM::VLD4d16_UPD:
2789     case ARM::VLD4d32_UPD:
2790       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
2791         return MCDisassembler::Fail;
2792       break;
2793     case ARM::VLD4q8:
2794     case ARM::VLD4q16:
2795     case ARM::VLD4q32:
2796     case ARM::VLD4q8_UPD:
2797     case ARM::VLD4q16_UPD:
2798     case ARM::VLD4q32_UPD:
2799       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
2800         return MCDisassembler::Fail;
2801       break;
2802     default:
2803       break;
2804   }
2805 
2806   // Writeback operand
2807   switch (Inst.getOpcode()) {
2808     case ARM::VLD1d8wb_fixed:
2809     case ARM::VLD1d16wb_fixed:
2810     case ARM::VLD1d32wb_fixed:
2811     case ARM::VLD1d64wb_fixed:
2812     case ARM::VLD1d8wb_register:
2813     case ARM::VLD1d16wb_register:
2814     case ARM::VLD1d32wb_register:
2815     case ARM::VLD1d64wb_register:
2816     case ARM::VLD1q8wb_fixed:
2817     case ARM::VLD1q16wb_fixed:
2818     case ARM::VLD1q32wb_fixed:
2819     case ARM::VLD1q64wb_fixed:
2820     case ARM::VLD1q8wb_register:
2821     case ARM::VLD1q16wb_register:
2822     case ARM::VLD1q32wb_register:
2823     case ARM::VLD1q64wb_register:
2824     case ARM::VLD1d8Twb_fixed:
2825     case ARM::VLD1d8Twb_register:
2826     case ARM::VLD1d16Twb_fixed:
2827     case ARM::VLD1d16Twb_register:
2828     case ARM::VLD1d32Twb_fixed:
2829     case ARM::VLD1d32Twb_register:
2830     case ARM::VLD1d64Twb_fixed:
2831     case ARM::VLD1d64Twb_register:
2832     case ARM::VLD1d8Qwb_fixed:
2833     case ARM::VLD1d8Qwb_register:
2834     case ARM::VLD1d16Qwb_fixed:
2835     case ARM::VLD1d16Qwb_register:
2836     case ARM::VLD1d32Qwb_fixed:
2837     case ARM::VLD1d32Qwb_register:
2838     case ARM::VLD1d64Qwb_fixed:
2839     case ARM::VLD1d64Qwb_register:
2840     case ARM::VLD2d8wb_fixed:
2841     case ARM::VLD2d16wb_fixed:
2842     case ARM::VLD2d32wb_fixed:
2843     case ARM::VLD2q8wb_fixed:
2844     case ARM::VLD2q16wb_fixed:
2845     case ARM::VLD2q32wb_fixed:
2846     case ARM::VLD2d8wb_register:
2847     case ARM::VLD2d16wb_register:
2848     case ARM::VLD2d32wb_register:
2849     case ARM::VLD2q8wb_register:
2850     case ARM::VLD2q16wb_register:
2851     case ARM::VLD2q32wb_register:
2852     case ARM::VLD2b8wb_fixed:
2853     case ARM::VLD2b16wb_fixed:
2854     case ARM::VLD2b32wb_fixed:
2855     case ARM::VLD2b8wb_register:
2856     case ARM::VLD2b16wb_register:
2857     case ARM::VLD2b32wb_register:
2858       Inst.addOperand(MCOperand::createImm(0));
2859       break;
2860     case ARM::VLD3d8_UPD:
2861     case ARM::VLD3d16_UPD:
2862     case ARM::VLD3d32_UPD:
2863     case ARM::VLD3q8_UPD:
2864     case ARM::VLD3q16_UPD:
2865     case ARM::VLD3q32_UPD:
2866     case ARM::VLD4d8_UPD:
2867     case ARM::VLD4d16_UPD:
2868     case ARM::VLD4d32_UPD:
2869     case ARM::VLD4q8_UPD:
2870     case ARM::VLD4q16_UPD:
2871     case ARM::VLD4q32_UPD:
2872       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
2873         return MCDisassembler::Fail;
2874       break;
2875     default:
2876       break;
2877   }
2878 
2879   // AddrMode6 Base (register+alignment)
2880   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
2881     return MCDisassembler::Fail;
2882 
2883   // AddrMode6 Offset (register)
2884   switch (Inst.getOpcode()) {
2885   default:
2886     // The below have been updated to have explicit am6offset split
2887     // between fixed and register offset. For those instructions not
2888     // yet updated, we need to add an additional reg0 operand for the
2889     // fixed variant.
2890     //
2891     // The fixed offset encodes as Rm == 0xd, so we check for that.
2892     if (Rm == 0xd) {
2893       Inst.addOperand(MCOperand::createReg(0));
2894       break;
2895     }
2896     // Fall through to handle the register offset variant.
2897     LLVM_FALLTHROUGH;
2898   case ARM::VLD1d8wb_fixed:
2899   case ARM::VLD1d16wb_fixed:
2900   case ARM::VLD1d32wb_fixed:
2901   case ARM::VLD1d64wb_fixed:
2902   case ARM::VLD1d8Twb_fixed:
2903   case ARM::VLD1d16Twb_fixed:
2904   case ARM::VLD1d32Twb_fixed:
2905   case ARM::VLD1d64Twb_fixed:
2906   case ARM::VLD1d8Qwb_fixed:
2907   case ARM::VLD1d16Qwb_fixed:
2908   case ARM::VLD1d32Qwb_fixed:
2909   case ARM::VLD1d64Qwb_fixed:
2910   case ARM::VLD1d8wb_register:
2911   case ARM::VLD1d16wb_register:
2912   case ARM::VLD1d32wb_register:
2913   case ARM::VLD1d64wb_register:
2914   case ARM::VLD1q8wb_fixed:
2915   case ARM::VLD1q16wb_fixed:
2916   case ARM::VLD1q32wb_fixed:
2917   case ARM::VLD1q64wb_fixed:
2918   case ARM::VLD1q8wb_register:
2919   case ARM::VLD1q16wb_register:
2920   case ARM::VLD1q32wb_register:
2921   case ARM::VLD1q64wb_register:
2922     // The fixed offset post-increment encodes Rm == 0xd. The no-writeback
2923     // variant encodes Rm == 0xf. Anything else is a register offset post-
2924     // increment and we need to add the register operand to the instruction.
2925     if (Rm != 0xD && Rm != 0xF &&
2926         !Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2927       return MCDisassembler::Fail;
2928     break;
2929   case ARM::VLD2d8wb_fixed:
2930   case ARM::VLD2d16wb_fixed:
2931   case ARM::VLD2d32wb_fixed:
2932   case ARM::VLD2b8wb_fixed:
2933   case ARM::VLD2b16wb_fixed:
2934   case ARM::VLD2b32wb_fixed:
2935   case ARM::VLD2q8wb_fixed:
2936   case ARM::VLD2q16wb_fixed:
2937   case ARM::VLD2q32wb_fixed:
2938     break;
2939   }
2940 
2941   return S;
2942 }
2943 
2944 static DecodeStatus DecodeVLDST1Instruction(MCInst &Inst, unsigned Insn,
2945                                    uint64_t Address, const void *Decoder) {
2946   unsigned type = fieldFromInstruction(Insn, 8, 4);
2947   unsigned align = fieldFromInstruction(Insn, 4, 2);
2948   if (type == 6 && (align & 2)) return MCDisassembler::Fail;
2949   if (type == 7 && (align & 2)) return MCDisassembler::Fail;
2950   if (type == 10 && align == 3) return MCDisassembler::Fail;
2951 
2952   unsigned load = fieldFromInstruction(Insn, 21, 1);
2953   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2954               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2955 }
2956 
2957 static DecodeStatus DecodeVLDST2Instruction(MCInst &Inst, unsigned Insn,
2958                                    uint64_t Address, const void *Decoder) {
2959   unsigned size = fieldFromInstruction(Insn, 6, 2);
2960   if (size == 3) return MCDisassembler::Fail;
2961 
2962   unsigned type = fieldFromInstruction(Insn, 8, 4);
2963   unsigned align = fieldFromInstruction(Insn, 4, 2);
2964   if (type == 8 && align == 3) return MCDisassembler::Fail;
2965   if (type == 9 && align == 3) return MCDisassembler::Fail;
2966 
2967   unsigned load = fieldFromInstruction(Insn, 21, 1);
2968   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2969               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2970 }
2971 
2972 static DecodeStatus DecodeVLDST3Instruction(MCInst &Inst, unsigned Insn,
2973                                    uint64_t Address, const void *Decoder) {
2974   unsigned size = fieldFromInstruction(Insn, 6, 2);
2975   if (size == 3) return MCDisassembler::Fail;
2976 
2977   unsigned align = fieldFromInstruction(Insn, 4, 2);
2978   if (align & 2) return MCDisassembler::Fail;
2979 
2980   unsigned load = fieldFromInstruction(Insn, 21, 1);
2981   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2982               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2983 }
2984 
2985 static DecodeStatus DecodeVLDST4Instruction(MCInst &Inst, unsigned Insn,
2986                                    uint64_t Address, const void *Decoder) {
2987   unsigned size = fieldFromInstruction(Insn, 6, 2);
2988   if (size == 3) return MCDisassembler::Fail;
2989 
2990   unsigned load = fieldFromInstruction(Insn, 21, 1);
2991   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2992               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2993 }
2994 
2995 static DecodeStatus DecodeVSTInstruction(MCInst &Inst, unsigned Insn,
2996                                  uint64_t Address, const void *Decoder) {
2997   DecodeStatus S = MCDisassembler::Success;
2998 
2999   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3000   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3001   unsigned wb = fieldFromInstruction(Insn, 16, 4);
3002   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3003   Rn |= fieldFromInstruction(Insn, 4, 2) << 4;
3004   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3005 
3006   // Writeback Operand
3007   switch (Inst.getOpcode()) {
3008     case ARM::VST1d8wb_fixed:
3009     case ARM::VST1d16wb_fixed:
3010     case ARM::VST1d32wb_fixed:
3011     case ARM::VST1d64wb_fixed:
3012     case ARM::VST1d8wb_register:
3013     case ARM::VST1d16wb_register:
3014     case ARM::VST1d32wb_register:
3015     case ARM::VST1d64wb_register:
3016     case ARM::VST1q8wb_fixed:
3017     case ARM::VST1q16wb_fixed:
3018     case ARM::VST1q32wb_fixed:
3019     case ARM::VST1q64wb_fixed:
3020     case ARM::VST1q8wb_register:
3021     case ARM::VST1q16wb_register:
3022     case ARM::VST1q32wb_register:
3023     case ARM::VST1q64wb_register:
3024     case ARM::VST1d8Twb_fixed:
3025     case ARM::VST1d16Twb_fixed:
3026     case ARM::VST1d32Twb_fixed:
3027     case ARM::VST1d64Twb_fixed:
3028     case ARM::VST1d8Twb_register:
3029     case ARM::VST1d16Twb_register:
3030     case ARM::VST1d32Twb_register:
3031     case ARM::VST1d64Twb_register:
3032     case ARM::VST1d8Qwb_fixed:
3033     case ARM::VST1d16Qwb_fixed:
3034     case ARM::VST1d32Qwb_fixed:
3035     case ARM::VST1d64Qwb_fixed:
3036     case ARM::VST1d8Qwb_register:
3037     case ARM::VST1d16Qwb_register:
3038     case ARM::VST1d32Qwb_register:
3039     case ARM::VST1d64Qwb_register:
3040     case ARM::VST2d8wb_fixed:
3041     case ARM::VST2d16wb_fixed:
3042     case ARM::VST2d32wb_fixed:
3043     case ARM::VST2d8wb_register:
3044     case ARM::VST2d16wb_register:
3045     case ARM::VST2d32wb_register:
3046     case ARM::VST2q8wb_fixed:
3047     case ARM::VST2q16wb_fixed:
3048     case ARM::VST2q32wb_fixed:
3049     case ARM::VST2q8wb_register:
3050     case ARM::VST2q16wb_register:
3051     case ARM::VST2q32wb_register:
3052     case ARM::VST2b8wb_fixed:
3053     case ARM::VST2b16wb_fixed:
3054     case ARM::VST2b32wb_fixed:
3055     case ARM::VST2b8wb_register:
3056     case ARM::VST2b16wb_register:
3057     case ARM::VST2b32wb_register:
3058       if (Rm == 0xF)
3059         return MCDisassembler::Fail;
3060       Inst.addOperand(MCOperand::createImm(0));
3061       break;
3062     case ARM::VST3d8_UPD:
3063     case ARM::VST3d16_UPD:
3064     case ARM::VST3d32_UPD:
3065     case ARM::VST3q8_UPD:
3066     case ARM::VST3q16_UPD:
3067     case ARM::VST3q32_UPD:
3068     case ARM::VST4d8_UPD:
3069     case ARM::VST4d16_UPD:
3070     case ARM::VST4d32_UPD:
3071     case ARM::VST4q8_UPD:
3072     case ARM::VST4q16_UPD:
3073     case ARM::VST4q32_UPD:
3074       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
3075         return MCDisassembler::Fail;
3076       break;
3077     default:
3078       break;
3079   }
3080 
3081   // AddrMode6 Base (register+alignment)
3082   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
3083     return MCDisassembler::Fail;
3084 
3085   // AddrMode6 Offset (register)
3086   switch (Inst.getOpcode()) {
3087     default:
3088       if (Rm == 0xD)
3089         Inst.addOperand(MCOperand::createReg(0));
3090       else if (Rm != 0xF) {
3091         if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3092           return MCDisassembler::Fail;
3093       }
3094       break;
3095     case ARM::VST1d8wb_fixed:
3096     case ARM::VST1d16wb_fixed:
3097     case ARM::VST1d32wb_fixed:
3098     case ARM::VST1d64wb_fixed:
3099     case ARM::VST1q8wb_fixed:
3100     case ARM::VST1q16wb_fixed:
3101     case ARM::VST1q32wb_fixed:
3102     case ARM::VST1q64wb_fixed:
3103     case ARM::VST1d8Twb_fixed:
3104     case ARM::VST1d16Twb_fixed:
3105     case ARM::VST1d32Twb_fixed:
3106     case ARM::VST1d64Twb_fixed:
3107     case ARM::VST1d8Qwb_fixed:
3108     case ARM::VST1d16Qwb_fixed:
3109     case ARM::VST1d32Qwb_fixed:
3110     case ARM::VST1d64Qwb_fixed:
3111     case ARM::VST2d8wb_fixed:
3112     case ARM::VST2d16wb_fixed:
3113     case ARM::VST2d32wb_fixed:
3114     case ARM::VST2q8wb_fixed:
3115     case ARM::VST2q16wb_fixed:
3116     case ARM::VST2q32wb_fixed:
3117     case ARM::VST2b8wb_fixed:
3118     case ARM::VST2b16wb_fixed:
3119     case ARM::VST2b32wb_fixed:
3120       break;
3121   }
3122 
3123   // First input register
3124   switch (Inst.getOpcode()) {
3125   case ARM::VST1q16:
3126   case ARM::VST1q32:
3127   case ARM::VST1q64:
3128   case ARM::VST1q8:
3129   case ARM::VST1q16wb_fixed:
3130   case ARM::VST1q16wb_register:
3131   case ARM::VST1q32wb_fixed:
3132   case ARM::VST1q32wb_register:
3133   case ARM::VST1q64wb_fixed:
3134   case ARM::VST1q64wb_register:
3135   case ARM::VST1q8wb_fixed:
3136   case ARM::VST1q8wb_register:
3137   case ARM::VST2d16:
3138   case ARM::VST2d32:
3139   case ARM::VST2d8:
3140   case ARM::VST2d16wb_fixed:
3141   case ARM::VST2d16wb_register:
3142   case ARM::VST2d32wb_fixed:
3143   case ARM::VST2d32wb_register:
3144   case ARM::VST2d8wb_fixed:
3145   case ARM::VST2d8wb_register:
3146     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3147       return MCDisassembler::Fail;
3148     break;
3149   case ARM::VST2b16:
3150   case ARM::VST2b32:
3151   case ARM::VST2b8:
3152   case ARM::VST2b16wb_fixed:
3153   case ARM::VST2b16wb_register:
3154   case ARM::VST2b32wb_fixed:
3155   case ARM::VST2b32wb_register:
3156   case ARM::VST2b8wb_fixed:
3157   case ARM::VST2b8wb_register:
3158     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
3159       return MCDisassembler::Fail;
3160     break;
3161   default:
3162     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3163       return MCDisassembler::Fail;
3164   }
3165 
3166   // Second input register
3167   switch (Inst.getOpcode()) {
3168     case ARM::VST3d8:
3169     case ARM::VST3d16:
3170     case ARM::VST3d32:
3171     case ARM::VST3d8_UPD:
3172     case ARM::VST3d16_UPD:
3173     case ARM::VST3d32_UPD:
3174     case ARM::VST4d8:
3175     case ARM::VST4d16:
3176     case ARM::VST4d32:
3177     case ARM::VST4d8_UPD:
3178     case ARM::VST4d16_UPD:
3179     case ARM::VST4d32_UPD:
3180       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
3181         return MCDisassembler::Fail;
3182       break;
3183     case ARM::VST3q8:
3184     case ARM::VST3q16:
3185     case ARM::VST3q32:
3186     case ARM::VST3q8_UPD:
3187     case ARM::VST3q16_UPD:
3188     case ARM::VST3q32_UPD:
3189     case ARM::VST4q8:
3190     case ARM::VST4q16:
3191     case ARM::VST4q32:
3192     case ARM::VST4q8_UPD:
3193     case ARM::VST4q16_UPD:
3194     case ARM::VST4q32_UPD:
3195       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
3196         return MCDisassembler::Fail;
3197       break;
3198     default:
3199       break;
3200   }
3201 
3202   // Third input register
3203   switch (Inst.getOpcode()) {
3204     case ARM::VST3d8:
3205     case ARM::VST3d16:
3206     case ARM::VST3d32:
3207     case ARM::VST3d8_UPD:
3208     case ARM::VST3d16_UPD:
3209     case ARM::VST3d32_UPD:
3210     case ARM::VST4d8:
3211     case ARM::VST4d16:
3212     case ARM::VST4d32:
3213     case ARM::VST4d8_UPD:
3214     case ARM::VST4d16_UPD:
3215     case ARM::VST4d32_UPD:
3216       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
3217         return MCDisassembler::Fail;
3218       break;
3219     case ARM::VST3q8:
3220     case ARM::VST3q16:
3221     case ARM::VST3q32:
3222     case ARM::VST3q8_UPD:
3223     case ARM::VST3q16_UPD:
3224     case ARM::VST3q32_UPD:
3225     case ARM::VST4q8:
3226     case ARM::VST4q16:
3227     case ARM::VST4q32:
3228     case ARM::VST4q8_UPD:
3229     case ARM::VST4q16_UPD:
3230     case ARM::VST4q32_UPD:
3231       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
3232         return MCDisassembler::Fail;
3233       break;
3234     default:
3235       break;
3236   }
3237 
3238   // Fourth input register
3239   switch (Inst.getOpcode()) {
3240     case ARM::VST4d8:
3241     case ARM::VST4d16:
3242     case ARM::VST4d32:
3243     case ARM::VST4d8_UPD:
3244     case ARM::VST4d16_UPD:
3245     case ARM::VST4d32_UPD:
3246       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
3247         return MCDisassembler::Fail;
3248       break;
3249     case ARM::VST4q8:
3250     case ARM::VST4q16:
3251     case ARM::VST4q32:
3252     case ARM::VST4q8_UPD:
3253     case ARM::VST4q16_UPD:
3254     case ARM::VST4q32_UPD:
3255       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
3256         return MCDisassembler::Fail;
3257       break;
3258     default:
3259       break;
3260   }
3261 
3262   return S;
3263 }
3264 
3265 static DecodeStatus DecodeVLD1DupInstruction(MCInst &Inst, unsigned Insn,
3266                                     uint64_t Address, const void *Decoder) {
3267   DecodeStatus S = MCDisassembler::Success;
3268 
3269   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3270   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3271   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3272   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3273   unsigned align = fieldFromInstruction(Insn, 4, 1);
3274   unsigned size = fieldFromInstruction(Insn, 6, 2);
3275 
3276   if (size == 0 && align == 1)
3277     return MCDisassembler::Fail;
3278   align *= (1 << size);
3279 
3280   switch (Inst.getOpcode()) {
3281   case ARM::VLD1DUPq16: case ARM::VLD1DUPq32: case ARM::VLD1DUPq8:
3282   case ARM::VLD1DUPq16wb_fixed: case ARM::VLD1DUPq16wb_register:
3283   case ARM::VLD1DUPq32wb_fixed: case ARM::VLD1DUPq32wb_register:
3284   case ARM::VLD1DUPq8wb_fixed: case ARM::VLD1DUPq8wb_register:
3285     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3286       return MCDisassembler::Fail;
3287     break;
3288   default:
3289     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3290       return MCDisassembler::Fail;
3291     break;
3292   }
3293   if (Rm != 0xF) {
3294     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3295       return MCDisassembler::Fail;
3296   }
3297 
3298   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3299     return MCDisassembler::Fail;
3300   Inst.addOperand(MCOperand::createImm(align));
3301 
3302   // The fixed offset post-increment encodes Rm == 0xd. The no-writeback
3303   // variant encodes Rm == 0xf. Anything else is a register offset post-
3304   // increment and we need to add the register operand to the instruction.
3305   if (Rm != 0xD && Rm != 0xF &&
3306       !Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3307     return MCDisassembler::Fail;
3308 
3309   return S;
3310 }
3311 
3312 static DecodeStatus DecodeVLD2DupInstruction(MCInst &Inst, unsigned Insn,
3313                                     uint64_t Address, const void *Decoder) {
3314   DecodeStatus S = MCDisassembler::Success;
3315 
3316   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3317   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3318   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3319   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3320   unsigned align = fieldFromInstruction(Insn, 4, 1);
3321   unsigned size = 1 << fieldFromInstruction(Insn, 6, 2);
3322   align *= 2*size;
3323 
3324   switch (Inst.getOpcode()) {
3325   case ARM::VLD2DUPd16: case ARM::VLD2DUPd32: case ARM::VLD2DUPd8:
3326   case ARM::VLD2DUPd16wb_fixed: case ARM::VLD2DUPd16wb_register:
3327   case ARM::VLD2DUPd32wb_fixed: case ARM::VLD2DUPd32wb_register:
3328   case ARM::VLD2DUPd8wb_fixed: case ARM::VLD2DUPd8wb_register:
3329     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3330       return MCDisassembler::Fail;
3331     break;
3332   case ARM::VLD2DUPd16x2: case ARM::VLD2DUPd32x2: case ARM::VLD2DUPd8x2:
3333   case ARM::VLD2DUPd16x2wb_fixed: case ARM::VLD2DUPd16x2wb_register:
3334   case ARM::VLD2DUPd32x2wb_fixed: case ARM::VLD2DUPd32x2wb_register:
3335   case ARM::VLD2DUPd8x2wb_fixed: case ARM::VLD2DUPd8x2wb_register:
3336     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
3337       return MCDisassembler::Fail;
3338     break;
3339   default:
3340     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3341       return MCDisassembler::Fail;
3342     break;
3343   }
3344 
3345   if (Rm != 0xF)
3346     Inst.addOperand(MCOperand::createImm(0));
3347 
3348   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3349     return MCDisassembler::Fail;
3350   Inst.addOperand(MCOperand::createImm(align));
3351 
3352   if (Rm != 0xD && Rm != 0xF) {
3353     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3354       return MCDisassembler::Fail;
3355   }
3356 
3357   return S;
3358 }
3359 
3360 static DecodeStatus DecodeVLD3DupInstruction(MCInst &Inst, unsigned Insn,
3361                                     uint64_t Address, const void *Decoder) {
3362   DecodeStatus S = MCDisassembler::Success;
3363 
3364   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3365   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3366   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3367   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3368   unsigned inc = fieldFromInstruction(Insn, 5, 1) + 1;
3369 
3370   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3371     return MCDisassembler::Fail;
3372   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
3373     return MCDisassembler::Fail;
3374   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
3375     return MCDisassembler::Fail;
3376   if (Rm != 0xF) {
3377     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3378       return MCDisassembler::Fail;
3379   }
3380 
3381   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3382     return MCDisassembler::Fail;
3383   Inst.addOperand(MCOperand::createImm(0));
3384 
3385   if (Rm == 0xD)
3386     Inst.addOperand(MCOperand::createReg(0));
3387   else if (Rm != 0xF) {
3388     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3389       return MCDisassembler::Fail;
3390   }
3391 
3392   return S;
3393 }
3394 
3395 static DecodeStatus DecodeVLD4DupInstruction(MCInst &Inst, unsigned Insn,
3396                                     uint64_t Address, const void *Decoder) {
3397   DecodeStatus S = MCDisassembler::Success;
3398 
3399   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3400   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3401   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3402   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3403   unsigned size = fieldFromInstruction(Insn, 6, 2);
3404   unsigned inc = fieldFromInstruction(Insn, 5, 1) + 1;
3405   unsigned align = fieldFromInstruction(Insn, 4, 1);
3406 
3407   if (size == 0x3) {
3408     if (align == 0)
3409       return MCDisassembler::Fail;
3410     align = 16;
3411   } else {
3412     if (size == 2) {
3413       align *= 8;
3414     } else {
3415       size = 1 << size;
3416       align *= 4*size;
3417     }
3418   }
3419 
3420   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3421     return MCDisassembler::Fail;
3422   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
3423     return MCDisassembler::Fail;
3424   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
3425     return MCDisassembler::Fail;
3426   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3*inc)%32, Address, Decoder)))
3427     return MCDisassembler::Fail;
3428   if (Rm != 0xF) {
3429     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3430       return MCDisassembler::Fail;
3431   }
3432 
3433   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3434     return MCDisassembler::Fail;
3435   Inst.addOperand(MCOperand::createImm(align));
3436 
3437   if (Rm == 0xD)
3438     Inst.addOperand(MCOperand::createReg(0));
3439   else if (Rm != 0xF) {
3440     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3441       return MCDisassembler::Fail;
3442   }
3443 
3444   return S;
3445 }
3446 
3447 static DecodeStatus
3448 DecodeNEONModImmInstruction(MCInst &Inst, unsigned Insn,
3449                             uint64_t Address, const void *Decoder) {
3450   DecodeStatus S = MCDisassembler::Success;
3451 
3452   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3453   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3454   unsigned imm = fieldFromInstruction(Insn, 0, 4);
3455   imm |= fieldFromInstruction(Insn, 16, 3) << 4;
3456   imm |= fieldFromInstruction(Insn, 24, 1) << 7;
3457   imm |= fieldFromInstruction(Insn, 8, 4) << 8;
3458   imm |= fieldFromInstruction(Insn, 5, 1) << 12;
3459   unsigned Q = fieldFromInstruction(Insn, 6, 1);
3460 
3461   if (Q) {
3462     if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3463     return MCDisassembler::Fail;
3464   } else {
3465     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3466     return MCDisassembler::Fail;
3467   }
3468 
3469   Inst.addOperand(MCOperand::createImm(imm));
3470 
3471   switch (Inst.getOpcode()) {
3472     case ARM::VORRiv4i16:
3473     case ARM::VORRiv2i32:
3474     case ARM::VBICiv4i16:
3475     case ARM::VBICiv2i32:
3476       if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3477         return MCDisassembler::Fail;
3478       break;
3479     case ARM::VORRiv8i16:
3480     case ARM::VORRiv4i32:
3481     case ARM::VBICiv8i16:
3482     case ARM::VBICiv4i32:
3483       if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3484         return MCDisassembler::Fail;
3485       break;
3486     default:
3487       break;
3488   }
3489 
3490   return S;
3491 }
3492 
3493 static DecodeStatus
3494 DecodeMVEModImmInstruction(MCInst &Inst, unsigned Insn,
3495                            uint64_t Address, const void *Decoder) {
3496   DecodeStatus S = MCDisassembler::Success;
3497 
3498   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
3499                  fieldFromInstruction(Insn, 13, 3));
3500   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
3501   unsigned imm = fieldFromInstruction(Insn, 0, 4);
3502   imm |= fieldFromInstruction(Insn, 16, 3) << 4;
3503   imm |= fieldFromInstruction(Insn, 28, 1) << 7;
3504   imm |= cmode                             << 8;
3505   imm |= fieldFromInstruction(Insn, 5, 1)  << 12;
3506 
3507   if (cmode == 0xF && Inst.getOpcode() == ARM::MVE_VMVNimmi32)
3508     return MCDisassembler::Fail;
3509 
3510   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
3511     return MCDisassembler::Fail;
3512 
3513   Inst.addOperand(MCOperand::createImm(imm));
3514 
3515   Inst.addOperand(MCOperand::createImm(ARMVCC::None));
3516   Inst.addOperand(MCOperand::createReg(0));
3517   Inst.addOperand(MCOperand::createImm(0));
3518 
3519   return S;
3520 }
3521 
3522 static DecodeStatus DecodeMVEVADCInstruction(MCInst &Inst, unsigned Insn,
3523                                uint64_t Address, const void *Decoder) {
3524   DecodeStatus S = MCDisassembler::Success;
3525 
3526   unsigned Qd = fieldFromInstruction(Insn, 13, 3);
3527   Qd |= fieldFromInstruction(Insn, 22, 1) << 3;
3528   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
3529     return MCDisassembler::Fail;
3530   Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
3531 
3532   unsigned Qn = fieldFromInstruction(Insn, 17, 3);
3533   Qn |= fieldFromInstruction(Insn, 7, 1) << 3;
3534   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qn, Address, Decoder)))
3535     return MCDisassembler::Fail;
3536   unsigned Qm = fieldFromInstruction(Insn, 1, 3);
3537   Qm |= fieldFromInstruction(Insn, 5, 1) << 3;
3538   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
3539     return MCDisassembler::Fail;
3540   if (!fieldFromInstruction(Insn, 12, 1)) // I bit clear => need input FPSCR
3541     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
3542   Inst.addOperand(MCOperand::createImm(Qd));
3543 
3544   return S;
3545 }
3546 
3547 static DecodeStatus DecodeVSHLMaxInstruction(MCInst &Inst, unsigned Insn,
3548                                         uint64_t Address, const void *Decoder) {
3549   DecodeStatus S = MCDisassembler::Success;
3550 
3551   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3552   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3553   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3554   Rm |= fieldFromInstruction(Insn, 5, 1) << 4;
3555   unsigned size = fieldFromInstruction(Insn, 18, 2);
3556 
3557   if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3558     return MCDisassembler::Fail;
3559   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
3560     return MCDisassembler::Fail;
3561   Inst.addOperand(MCOperand::createImm(8 << size));
3562 
3563   return S;
3564 }
3565 
3566 static DecodeStatus DecodeShiftRight8Imm(MCInst &Inst, unsigned Val,
3567                                uint64_t Address, const void *Decoder) {
3568   Inst.addOperand(MCOperand::createImm(8 - Val));
3569   return MCDisassembler::Success;
3570 }
3571 
3572 static DecodeStatus DecodeShiftRight16Imm(MCInst &Inst, unsigned Val,
3573                                uint64_t Address, const void *Decoder) {
3574   Inst.addOperand(MCOperand::createImm(16 - Val));
3575   return MCDisassembler::Success;
3576 }
3577 
3578 static DecodeStatus DecodeShiftRight32Imm(MCInst &Inst, unsigned Val,
3579                                uint64_t Address, const void *Decoder) {
3580   Inst.addOperand(MCOperand::createImm(32 - Val));
3581   return MCDisassembler::Success;
3582 }
3583 
3584 static DecodeStatus DecodeShiftRight64Imm(MCInst &Inst, unsigned Val,
3585                                uint64_t Address, const void *Decoder) {
3586   Inst.addOperand(MCOperand::createImm(64 - Val));
3587   return MCDisassembler::Success;
3588 }
3589 
3590 static DecodeStatus DecodeTBLInstruction(MCInst &Inst, unsigned Insn,
3591                                uint64_t Address, const void *Decoder) {
3592   DecodeStatus S = MCDisassembler::Success;
3593 
3594   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3595   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3596   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3597   Rn |= fieldFromInstruction(Insn, 7, 1) << 4;
3598   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3599   Rm |= fieldFromInstruction(Insn, 5, 1) << 4;
3600   unsigned op = fieldFromInstruction(Insn, 6, 1);
3601 
3602   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3603     return MCDisassembler::Fail;
3604   if (op) {
3605     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3606     return MCDisassembler::Fail; // Writeback
3607   }
3608 
3609   switch (Inst.getOpcode()) {
3610   case ARM::VTBL2:
3611   case ARM::VTBX2:
3612     if (!Check(S, DecodeDPairRegisterClass(Inst, Rn, Address, Decoder)))
3613       return MCDisassembler::Fail;
3614     break;
3615   default:
3616     if (!Check(S, DecodeDPRRegisterClass(Inst, Rn, Address, Decoder)))
3617       return MCDisassembler::Fail;
3618   }
3619 
3620   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
3621     return MCDisassembler::Fail;
3622 
3623   return S;
3624 }
3625 
3626 static DecodeStatus DecodeThumbAddSpecialReg(MCInst &Inst, uint16_t Insn,
3627                                      uint64_t Address, const void *Decoder) {
3628   DecodeStatus S = MCDisassembler::Success;
3629 
3630   unsigned dst = fieldFromInstruction(Insn, 8, 3);
3631   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3632 
3633   if (!Check(S, DecodetGPRRegisterClass(Inst, dst, Address, Decoder)))
3634     return MCDisassembler::Fail;
3635 
3636   switch(Inst.getOpcode()) {
3637     default:
3638       return MCDisassembler::Fail;
3639     case ARM::tADR:
3640       break; // tADR does not explicitly represent the PC as an operand.
3641     case ARM::tADDrSPi:
3642       Inst.addOperand(MCOperand::createReg(ARM::SP));
3643       break;
3644   }
3645 
3646   Inst.addOperand(MCOperand::createImm(imm));
3647   return S;
3648 }
3649 
3650 static DecodeStatus DecodeThumbBROperand(MCInst &Inst, unsigned Val,
3651                                  uint64_t Address, const void *Decoder) {
3652   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<12>(Val<<1) + 4,
3653                                 true, 2, Inst, Decoder))
3654     Inst.addOperand(MCOperand::createImm(SignExtend32<12>(Val << 1)));
3655   return MCDisassembler::Success;
3656 }
3657 
3658 static DecodeStatus DecodeT2BROperand(MCInst &Inst, unsigned Val,
3659                                  uint64_t Address, const void *Decoder) {
3660   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<21>(Val) + 4,
3661                                 true, 4, Inst, Decoder))
3662     Inst.addOperand(MCOperand::createImm(SignExtend32<21>(Val)));
3663   return MCDisassembler::Success;
3664 }
3665 
3666 static DecodeStatus DecodeThumbCmpBROperand(MCInst &Inst, unsigned Val,
3667                                  uint64_t Address, const void *Decoder) {
3668   if (!tryAddingSymbolicOperand(Address, Address + (Val<<1) + 4,
3669                                 true, 2, Inst, Decoder))
3670     Inst.addOperand(MCOperand::createImm(Val << 1));
3671   return MCDisassembler::Success;
3672 }
3673 
3674 static DecodeStatus DecodeThumbAddrModeRR(MCInst &Inst, unsigned Val,
3675                                  uint64_t Address, const void *Decoder) {
3676   DecodeStatus S = MCDisassembler::Success;
3677 
3678   unsigned Rn = fieldFromInstruction(Val, 0, 3);
3679   unsigned Rm = fieldFromInstruction(Val, 3, 3);
3680 
3681   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
3682     return MCDisassembler::Fail;
3683   if (!Check(S, DecodetGPRRegisterClass(Inst, Rm, Address, Decoder)))
3684     return MCDisassembler::Fail;
3685 
3686   return S;
3687 }
3688 
3689 static DecodeStatus DecodeThumbAddrModeIS(MCInst &Inst, unsigned Val,
3690                                   uint64_t Address, const void *Decoder) {
3691   DecodeStatus S = MCDisassembler::Success;
3692 
3693   unsigned Rn = fieldFromInstruction(Val, 0, 3);
3694   unsigned imm = fieldFromInstruction(Val, 3, 5);
3695 
3696   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
3697     return MCDisassembler::Fail;
3698   Inst.addOperand(MCOperand::createImm(imm));
3699 
3700   return S;
3701 }
3702 
3703 static DecodeStatus DecodeThumbAddrModePC(MCInst &Inst, unsigned Val,
3704                                   uint64_t Address, const void *Decoder) {
3705   unsigned imm = Val << 2;
3706 
3707   Inst.addOperand(MCOperand::createImm(imm));
3708   tryAddingPcLoadReferenceComment(Address, (Address & ~2u) + imm + 4, Decoder);
3709 
3710   return MCDisassembler::Success;
3711 }
3712 
3713 static DecodeStatus DecodeThumbAddrModeSP(MCInst &Inst, unsigned Val,
3714                                   uint64_t Address, const void *Decoder) {
3715   Inst.addOperand(MCOperand::createReg(ARM::SP));
3716   Inst.addOperand(MCOperand::createImm(Val));
3717 
3718   return MCDisassembler::Success;
3719 }
3720 
3721 static DecodeStatus DecodeT2AddrModeSOReg(MCInst &Inst, unsigned Val,
3722                                   uint64_t Address, const void *Decoder) {
3723   DecodeStatus S = MCDisassembler::Success;
3724 
3725   unsigned Rn = fieldFromInstruction(Val, 6, 4);
3726   unsigned Rm = fieldFromInstruction(Val, 2, 4);
3727   unsigned imm = fieldFromInstruction(Val, 0, 2);
3728 
3729   // Thumb stores cannot use PC as dest register.
3730   switch (Inst.getOpcode()) {
3731   case ARM::t2STRHs:
3732   case ARM::t2STRBs:
3733   case ARM::t2STRs:
3734     if (Rn == 15)
3735       return MCDisassembler::Fail;
3736     break;
3737   default:
3738     break;
3739   }
3740 
3741   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3742     return MCDisassembler::Fail;
3743   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
3744     return MCDisassembler::Fail;
3745   Inst.addOperand(MCOperand::createImm(imm));
3746 
3747   return S;
3748 }
3749 
3750 static DecodeStatus DecodeT2LoadShift(MCInst &Inst, unsigned Insn,
3751                               uint64_t Address, const void *Decoder) {
3752   DecodeStatus S = MCDisassembler::Success;
3753 
3754   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3755   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3756 
3757   const FeatureBitset &featureBits =
3758     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3759 
3760   bool hasMP = featureBits[ARM::FeatureMP];
3761   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3762 
3763   if (Rn == 15) {
3764     switch (Inst.getOpcode()) {
3765     case ARM::t2LDRBs:
3766       Inst.setOpcode(ARM::t2LDRBpci);
3767       break;
3768     case ARM::t2LDRHs:
3769       Inst.setOpcode(ARM::t2LDRHpci);
3770       break;
3771     case ARM::t2LDRSHs:
3772       Inst.setOpcode(ARM::t2LDRSHpci);
3773       break;
3774     case ARM::t2LDRSBs:
3775       Inst.setOpcode(ARM::t2LDRSBpci);
3776       break;
3777     case ARM::t2LDRs:
3778       Inst.setOpcode(ARM::t2LDRpci);
3779       break;
3780     case ARM::t2PLDs:
3781       Inst.setOpcode(ARM::t2PLDpci);
3782       break;
3783     case ARM::t2PLIs:
3784       Inst.setOpcode(ARM::t2PLIpci);
3785       break;
3786     default:
3787       return MCDisassembler::Fail;
3788     }
3789 
3790     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3791   }
3792 
3793   if (Rt == 15) {
3794     switch (Inst.getOpcode()) {
3795     case ARM::t2LDRSHs:
3796       return MCDisassembler::Fail;
3797     case ARM::t2LDRHs:
3798       Inst.setOpcode(ARM::t2PLDWs);
3799       break;
3800     case ARM::t2LDRSBs:
3801       Inst.setOpcode(ARM::t2PLIs);
3802       break;
3803     default:
3804       break;
3805     }
3806   }
3807 
3808   switch (Inst.getOpcode()) {
3809     case ARM::t2PLDs:
3810       break;
3811     case ARM::t2PLIs:
3812       if (!hasV7Ops)
3813         return MCDisassembler::Fail;
3814       break;
3815     case ARM::t2PLDWs:
3816       if (!hasV7Ops || !hasMP)
3817         return MCDisassembler::Fail;
3818       break;
3819     default:
3820       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3821         return MCDisassembler::Fail;
3822   }
3823 
3824   unsigned addrmode = fieldFromInstruction(Insn, 4, 2);
3825   addrmode |= fieldFromInstruction(Insn, 0, 4) << 2;
3826   addrmode |= fieldFromInstruction(Insn, 16, 4) << 6;
3827   if (!Check(S, DecodeT2AddrModeSOReg(Inst, addrmode, Address, Decoder)))
3828     return MCDisassembler::Fail;
3829 
3830   return S;
3831 }
3832 
3833 static DecodeStatus DecodeT2LoadImm8(MCInst &Inst, unsigned Insn,
3834                                 uint64_t Address, const void* Decoder) {
3835   DecodeStatus S = MCDisassembler::Success;
3836 
3837   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3838   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3839   unsigned U = fieldFromInstruction(Insn, 9, 1);
3840   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3841   imm |= (U << 8);
3842   imm |= (Rn << 9);
3843   unsigned add = fieldFromInstruction(Insn, 9, 1);
3844 
3845   const FeatureBitset &featureBits =
3846     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3847 
3848   bool hasMP = featureBits[ARM::FeatureMP];
3849   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3850 
3851   if (Rn == 15) {
3852     switch (Inst.getOpcode()) {
3853     case ARM::t2LDRi8:
3854       Inst.setOpcode(ARM::t2LDRpci);
3855       break;
3856     case ARM::t2LDRBi8:
3857       Inst.setOpcode(ARM::t2LDRBpci);
3858       break;
3859     case ARM::t2LDRSBi8:
3860       Inst.setOpcode(ARM::t2LDRSBpci);
3861       break;
3862     case ARM::t2LDRHi8:
3863       Inst.setOpcode(ARM::t2LDRHpci);
3864       break;
3865     case ARM::t2LDRSHi8:
3866       Inst.setOpcode(ARM::t2LDRSHpci);
3867       break;
3868     case ARM::t2PLDi8:
3869       Inst.setOpcode(ARM::t2PLDpci);
3870       break;
3871     case ARM::t2PLIi8:
3872       Inst.setOpcode(ARM::t2PLIpci);
3873       break;
3874     default:
3875       return MCDisassembler::Fail;
3876     }
3877     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3878   }
3879 
3880   if (Rt == 15) {
3881     switch (Inst.getOpcode()) {
3882     case ARM::t2LDRSHi8:
3883       return MCDisassembler::Fail;
3884     case ARM::t2LDRHi8:
3885       if (!add)
3886         Inst.setOpcode(ARM::t2PLDWi8);
3887       break;
3888     case ARM::t2LDRSBi8:
3889       Inst.setOpcode(ARM::t2PLIi8);
3890       break;
3891     default:
3892       break;
3893     }
3894   }
3895 
3896   switch (Inst.getOpcode()) {
3897   case ARM::t2PLDi8:
3898     break;
3899   case ARM::t2PLIi8:
3900     if (!hasV7Ops)
3901       return MCDisassembler::Fail;
3902     break;
3903   case ARM::t2PLDWi8:
3904       if (!hasV7Ops || !hasMP)
3905         return MCDisassembler::Fail;
3906       break;
3907   default:
3908     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3909       return MCDisassembler::Fail;
3910   }
3911 
3912   if (!Check(S, DecodeT2AddrModeImm8(Inst, imm, Address, Decoder)))
3913     return MCDisassembler::Fail;
3914   return S;
3915 }
3916 
3917 static DecodeStatus DecodeT2LoadImm12(MCInst &Inst, unsigned Insn,
3918                                 uint64_t Address, const void* Decoder) {
3919   DecodeStatus S = MCDisassembler::Success;
3920 
3921   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3922   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3923   unsigned imm = fieldFromInstruction(Insn, 0, 12);
3924   imm |= (Rn << 13);
3925 
3926   const FeatureBitset &featureBits =
3927     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3928 
3929   bool hasMP = featureBits[ARM::FeatureMP];
3930   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3931 
3932   if (Rn == 15) {
3933     switch (Inst.getOpcode()) {
3934     case ARM::t2LDRi12:
3935       Inst.setOpcode(ARM::t2LDRpci);
3936       break;
3937     case ARM::t2LDRHi12:
3938       Inst.setOpcode(ARM::t2LDRHpci);
3939       break;
3940     case ARM::t2LDRSHi12:
3941       Inst.setOpcode(ARM::t2LDRSHpci);
3942       break;
3943     case ARM::t2LDRBi12:
3944       Inst.setOpcode(ARM::t2LDRBpci);
3945       break;
3946     case ARM::t2LDRSBi12:
3947       Inst.setOpcode(ARM::t2LDRSBpci);
3948       break;
3949     case ARM::t2PLDi12:
3950       Inst.setOpcode(ARM::t2PLDpci);
3951       break;
3952     case ARM::t2PLIi12:
3953       Inst.setOpcode(ARM::t2PLIpci);
3954       break;
3955     default:
3956       return MCDisassembler::Fail;
3957     }
3958     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3959   }
3960 
3961   if (Rt == 15) {
3962     switch (Inst.getOpcode()) {
3963     case ARM::t2LDRSHi12:
3964       return MCDisassembler::Fail;
3965     case ARM::t2LDRHi12:
3966       Inst.setOpcode(ARM::t2PLDWi12);
3967       break;
3968     case ARM::t2LDRSBi12:
3969       Inst.setOpcode(ARM::t2PLIi12);
3970       break;
3971     default:
3972       break;
3973     }
3974   }
3975 
3976   switch (Inst.getOpcode()) {
3977   case ARM::t2PLDi12:
3978     break;
3979   case ARM::t2PLIi12:
3980     if (!hasV7Ops)
3981       return MCDisassembler::Fail;
3982     break;
3983   case ARM::t2PLDWi12:
3984       if (!hasV7Ops || !hasMP)
3985         return MCDisassembler::Fail;
3986       break;
3987   default:
3988     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3989       return MCDisassembler::Fail;
3990   }
3991 
3992   if (!Check(S, DecodeT2AddrModeImm12(Inst, imm, Address, Decoder)))
3993     return MCDisassembler::Fail;
3994   return S;
3995 }
3996 
3997 static DecodeStatus DecodeT2LoadT(MCInst &Inst, unsigned Insn,
3998                                 uint64_t Address, const void* Decoder) {
3999   DecodeStatus S = MCDisassembler::Success;
4000 
4001   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4002   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4003   unsigned imm = fieldFromInstruction(Insn, 0, 8);
4004   imm |= (Rn << 9);
4005 
4006   if (Rn == 15) {
4007     switch (Inst.getOpcode()) {
4008     case ARM::t2LDRT:
4009       Inst.setOpcode(ARM::t2LDRpci);
4010       break;
4011     case ARM::t2LDRBT:
4012       Inst.setOpcode(ARM::t2LDRBpci);
4013       break;
4014     case ARM::t2LDRHT:
4015       Inst.setOpcode(ARM::t2LDRHpci);
4016       break;
4017     case ARM::t2LDRSBT:
4018       Inst.setOpcode(ARM::t2LDRSBpci);
4019       break;
4020     case ARM::t2LDRSHT:
4021       Inst.setOpcode(ARM::t2LDRSHpci);
4022       break;
4023     default:
4024       return MCDisassembler::Fail;
4025     }
4026     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
4027   }
4028 
4029   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
4030     return MCDisassembler::Fail;
4031   if (!Check(S, DecodeT2AddrModeImm8(Inst, imm, Address, Decoder)))
4032     return MCDisassembler::Fail;
4033   return S;
4034 }
4035 
4036 static DecodeStatus DecodeT2LoadLabel(MCInst &Inst, unsigned Insn,
4037                                 uint64_t Address, const void* Decoder) {
4038   DecodeStatus S = MCDisassembler::Success;
4039 
4040   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4041   unsigned U = fieldFromInstruction(Insn, 23, 1);
4042   int imm = fieldFromInstruction(Insn, 0, 12);
4043 
4044   const FeatureBitset &featureBits =
4045     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4046 
4047   bool hasV7Ops = featureBits[ARM::HasV7Ops];
4048 
4049   if (Rt == 15) {
4050     switch (Inst.getOpcode()) {
4051       case ARM::t2LDRBpci:
4052       case ARM::t2LDRHpci:
4053         Inst.setOpcode(ARM::t2PLDpci);
4054         break;
4055       case ARM::t2LDRSBpci:
4056         Inst.setOpcode(ARM::t2PLIpci);
4057         break;
4058       case ARM::t2LDRSHpci:
4059         return MCDisassembler::Fail;
4060       default:
4061         break;
4062     }
4063   }
4064 
4065   switch(Inst.getOpcode()) {
4066   case ARM::t2PLDpci:
4067     break;
4068   case ARM::t2PLIpci:
4069     if (!hasV7Ops)
4070       return MCDisassembler::Fail;
4071     break;
4072   default:
4073     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4074       return MCDisassembler::Fail;
4075   }
4076 
4077   if (!U) {
4078     // Special case for #-0.
4079     if (imm == 0)
4080       imm = INT32_MIN;
4081     else
4082       imm = -imm;
4083   }
4084   Inst.addOperand(MCOperand::createImm(imm));
4085 
4086   return S;
4087 }
4088 
4089 static DecodeStatus DecodeT2Imm8S4(MCInst &Inst, unsigned Val,
4090                            uint64_t Address, const void *Decoder) {
4091   if (Val == 0)
4092     Inst.addOperand(MCOperand::createImm(INT32_MIN));
4093   else {
4094     int imm = Val & 0xFF;
4095 
4096     if (!(Val & 0x100)) imm *= -1;
4097     Inst.addOperand(MCOperand::createImm(imm * 4));
4098   }
4099 
4100   return MCDisassembler::Success;
4101 }
4102 
4103 static DecodeStatus DecodeT2Imm7S4(MCInst &Inst, unsigned Val, uint64_t Address,
4104                                    const void *Decoder) {
4105   if (Val == 0)
4106     Inst.addOperand(MCOperand::createImm(INT32_MIN));
4107   else {
4108     int imm = Val & 0x7F;
4109 
4110     if (!(Val & 0x80))
4111       imm *= -1;
4112     Inst.addOperand(MCOperand::createImm(imm * 4));
4113   }
4114 
4115   return MCDisassembler::Success;
4116 }
4117 
4118 static DecodeStatus DecodeT2AddrModeImm8s4(MCInst &Inst, unsigned Val,
4119                                    uint64_t Address, const void *Decoder) {
4120   DecodeStatus S = MCDisassembler::Success;
4121 
4122   unsigned Rn = fieldFromInstruction(Val, 9, 4);
4123   unsigned imm = fieldFromInstruction(Val, 0, 9);
4124 
4125   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4126     return MCDisassembler::Fail;
4127   if (!Check(S, DecodeT2Imm8S4(Inst, imm, Address, Decoder)))
4128     return MCDisassembler::Fail;
4129 
4130   return S;
4131 }
4132 
4133 static DecodeStatus DecodeT2AddrModeImm7s4(MCInst &Inst, unsigned Val,
4134                                            uint64_t Address,
4135                                            const void *Decoder) {
4136   DecodeStatus S = MCDisassembler::Success;
4137 
4138   unsigned Rn = fieldFromInstruction(Val, 8, 4);
4139   unsigned imm = fieldFromInstruction(Val, 0, 8);
4140 
4141   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4142     return MCDisassembler::Fail;
4143   if (!Check(S, DecodeT2Imm7S4(Inst, imm, Address, Decoder)))
4144     return MCDisassembler::Fail;
4145 
4146   return S;
4147 }
4148 
4149 static DecodeStatus DecodeT2AddrModeImm0_1020s4(MCInst &Inst,unsigned Val,
4150                                    uint64_t Address, const void *Decoder) {
4151   DecodeStatus S = MCDisassembler::Success;
4152 
4153   unsigned Rn = fieldFromInstruction(Val, 8, 4);
4154   unsigned imm = fieldFromInstruction(Val, 0, 8);
4155 
4156   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4157     return MCDisassembler::Fail;
4158 
4159   Inst.addOperand(MCOperand::createImm(imm));
4160 
4161   return S;
4162 }
4163 
4164 static DecodeStatus DecodeT2Imm8(MCInst &Inst, unsigned Val,
4165                          uint64_t Address, const void *Decoder) {
4166   int imm = Val & 0xFF;
4167   if (Val == 0)
4168     imm = INT32_MIN;
4169   else if (!(Val & 0x100))
4170     imm *= -1;
4171   Inst.addOperand(MCOperand::createImm(imm));
4172 
4173   return MCDisassembler::Success;
4174 }
4175 
4176 template<int shift>
4177 static DecodeStatus DecodeT2Imm7(MCInst &Inst, unsigned Val,
4178                          uint64_t Address, const void *Decoder) {
4179   int imm = Val & 0x7F;
4180   if (Val == 0)
4181     imm = INT32_MIN;
4182   else if (!(Val & 0x80))
4183     imm *= -1;
4184   if (imm != INT32_MIN)
4185     imm <<= shift;
4186   Inst.addOperand(MCOperand::createImm(imm));
4187 
4188   return MCDisassembler::Success;
4189 }
4190 
4191 static DecodeStatus DecodeT2AddrModeImm8(MCInst &Inst, unsigned Val,
4192                                  uint64_t Address, const void *Decoder) {
4193   DecodeStatus S = MCDisassembler::Success;
4194 
4195   unsigned Rn = fieldFromInstruction(Val, 9, 4);
4196   unsigned imm = fieldFromInstruction(Val, 0, 9);
4197 
4198   // Thumb stores cannot use PC as dest register.
4199   switch (Inst.getOpcode()) {
4200   case ARM::t2STRT:
4201   case ARM::t2STRBT:
4202   case ARM::t2STRHT:
4203   case ARM::t2STRi8:
4204   case ARM::t2STRHi8:
4205   case ARM::t2STRBi8:
4206     if (Rn == 15)
4207       return MCDisassembler::Fail;
4208     break;
4209   default:
4210     break;
4211   }
4212 
4213   // Some instructions always use an additive offset.
4214   switch (Inst.getOpcode()) {
4215     case ARM::t2LDRT:
4216     case ARM::t2LDRBT:
4217     case ARM::t2LDRHT:
4218     case ARM::t2LDRSBT:
4219     case ARM::t2LDRSHT:
4220     case ARM::t2STRT:
4221     case ARM::t2STRBT:
4222     case ARM::t2STRHT:
4223       imm |= 0x100;
4224       break;
4225     default:
4226       break;
4227   }
4228 
4229   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4230     return MCDisassembler::Fail;
4231   if (!Check(S, DecodeT2Imm8(Inst, imm, Address, Decoder)))
4232     return MCDisassembler::Fail;
4233 
4234   return S;
4235 }
4236 
4237 template<int shift>
4238 static DecodeStatus DecodeTAddrModeImm7(MCInst &Inst, unsigned Val,
4239                                          uint64_t Address,
4240                                          const void *Decoder) {
4241   DecodeStatus S = MCDisassembler::Success;
4242 
4243   unsigned Rn = fieldFromInstruction(Val, 8, 3);
4244   unsigned imm = fieldFromInstruction(Val, 0, 8);
4245 
4246   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
4247     return MCDisassembler::Fail;
4248   if (!Check(S, DecodeT2Imm7<shift>(Inst, imm, Address, Decoder)))
4249     return MCDisassembler::Fail;
4250 
4251   return S;
4252 }
4253 
4254 template<int shift, int WriteBack>
4255 static DecodeStatus DecodeT2AddrModeImm7(MCInst &Inst, unsigned Val,
4256                                          uint64_t Address,
4257                                          const void *Decoder) {
4258   DecodeStatus S = MCDisassembler::Success;
4259 
4260   unsigned Rn = fieldFromInstruction(Val, 8, 4);
4261   unsigned imm = fieldFromInstruction(Val, 0, 8);
4262   if (WriteBack) {
4263     if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
4264       return MCDisassembler::Fail;
4265   } else if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4266     return MCDisassembler::Fail;
4267   if (!Check(S, DecodeT2Imm7<shift>(Inst, imm, Address, Decoder)))
4268     return MCDisassembler::Fail;
4269 
4270   return S;
4271 }
4272 
4273 static DecodeStatus DecodeT2LdStPre(MCInst &Inst, unsigned Insn,
4274                                     uint64_t Address, const void *Decoder) {
4275   DecodeStatus S = MCDisassembler::Success;
4276 
4277   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4278   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4279   unsigned addr = fieldFromInstruction(Insn, 0, 8);
4280   addr |= fieldFromInstruction(Insn, 9, 1) << 8;
4281   addr |= Rn << 9;
4282   unsigned load = fieldFromInstruction(Insn, 20, 1);
4283 
4284   if (Rn == 15) {
4285     switch (Inst.getOpcode()) {
4286     case ARM::t2LDR_PRE:
4287     case ARM::t2LDR_POST:
4288       Inst.setOpcode(ARM::t2LDRpci);
4289       break;
4290     case ARM::t2LDRB_PRE:
4291     case ARM::t2LDRB_POST:
4292       Inst.setOpcode(ARM::t2LDRBpci);
4293       break;
4294     case ARM::t2LDRH_PRE:
4295     case ARM::t2LDRH_POST:
4296       Inst.setOpcode(ARM::t2LDRHpci);
4297       break;
4298     case ARM::t2LDRSB_PRE:
4299     case ARM::t2LDRSB_POST:
4300       if (Rt == 15)
4301         Inst.setOpcode(ARM::t2PLIpci);
4302       else
4303         Inst.setOpcode(ARM::t2LDRSBpci);
4304       break;
4305     case ARM::t2LDRSH_PRE:
4306     case ARM::t2LDRSH_POST:
4307       Inst.setOpcode(ARM::t2LDRSHpci);
4308       break;
4309     default:
4310       return MCDisassembler::Fail;
4311     }
4312     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
4313   }
4314 
4315   if (!load) {
4316     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4317       return MCDisassembler::Fail;
4318   }
4319 
4320   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4321     return MCDisassembler::Fail;
4322 
4323   if (load) {
4324     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4325       return MCDisassembler::Fail;
4326   }
4327 
4328   if (!Check(S, DecodeT2AddrModeImm8(Inst, addr, Address, Decoder)))
4329     return MCDisassembler::Fail;
4330 
4331   return S;
4332 }
4333 
4334 static DecodeStatus DecodeT2AddrModeImm12(MCInst &Inst, unsigned Val,
4335                                   uint64_t Address, const void *Decoder) {
4336   DecodeStatus S = MCDisassembler::Success;
4337 
4338   unsigned Rn = fieldFromInstruction(Val, 13, 4);
4339   unsigned imm = fieldFromInstruction(Val, 0, 12);
4340 
4341   // Thumb stores cannot use PC as dest register.
4342   switch (Inst.getOpcode()) {
4343   case ARM::t2STRi12:
4344   case ARM::t2STRBi12:
4345   case ARM::t2STRHi12:
4346     if (Rn == 15)
4347       return MCDisassembler::Fail;
4348     break;
4349   default:
4350     break;
4351   }
4352 
4353   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4354     return MCDisassembler::Fail;
4355   Inst.addOperand(MCOperand::createImm(imm));
4356 
4357   return S;
4358 }
4359 
4360 static DecodeStatus DecodeThumbAddSPImm(MCInst &Inst, uint16_t Insn,
4361                                 uint64_t Address, const void *Decoder) {
4362   unsigned imm = fieldFromInstruction(Insn, 0, 7);
4363 
4364   Inst.addOperand(MCOperand::createReg(ARM::SP));
4365   Inst.addOperand(MCOperand::createReg(ARM::SP));
4366   Inst.addOperand(MCOperand::createImm(imm));
4367 
4368   return MCDisassembler::Success;
4369 }
4370 
4371 static DecodeStatus DecodeThumbAddSPReg(MCInst &Inst, uint16_t Insn,
4372                                 uint64_t Address, const void *Decoder) {
4373   DecodeStatus S = MCDisassembler::Success;
4374 
4375   if (Inst.getOpcode() == ARM::tADDrSP) {
4376     unsigned Rdm = fieldFromInstruction(Insn, 0, 3);
4377     Rdm |= fieldFromInstruction(Insn, 7, 1) << 3;
4378 
4379     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
4380     return MCDisassembler::Fail;
4381     Inst.addOperand(MCOperand::createReg(ARM::SP));
4382     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
4383     return MCDisassembler::Fail;
4384   } else if (Inst.getOpcode() == ARM::tADDspr) {
4385     unsigned Rm = fieldFromInstruction(Insn, 3, 4);
4386 
4387     Inst.addOperand(MCOperand::createReg(ARM::SP));
4388     Inst.addOperand(MCOperand::createReg(ARM::SP));
4389     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4390     return MCDisassembler::Fail;
4391   }
4392 
4393   return S;
4394 }
4395 
4396 static DecodeStatus DecodeThumbCPS(MCInst &Inst, uint16_t Insn,
4397                            uint64_t Address, const void *Decoder) {
4398   unsigned imod = fieldFromInstruction(Insn, 4, 1) | 0x2;
4399   unsigned flags = fieldFromInstruction(Insn, 0, 3);
4400 
4401   Inst.addOperand(MCOperand::createImm(imod));
4402   Inst.addOperand(MCOperand::createImm(flags));
4403 
4404   return MCDisassembler::Success;
4405 }
4406 
4407 static DecodeStatus DecodePostIdxReg(MCInst &Inst, unsigned Insn,
4408                              uint64_t Address, const void *Decoder) {
4409   DecodeStatus S = MCDisassembler::Success;
4410   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4411   unsigned add = fieldFromInstruction(Insn, 4, 1);
4412 
4413   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
4414     return MCDisassembler::Fail;
4415   Inst.addOperand(MCOperand::createImm(add));
4416 
4417   return S;
4418 }
4419 
4420 static DecodeStatus DecodeMveAddrModeRQ(MCInst &Inst, unsigned Insn,
4421                              uint64_t Address, const void *Decoder) {
4422   DecodeStatus S = MCDisassembler::Success;
4423   unsigned Rn = fieldFromInstruction(Insn, 3, 4);
4424   unsigned Qm = fieldFromInstruction(Insn, 0, 3);
4425 
4426   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4427     return MCDisassembler::Fail;
4428   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
4429     return MCDisassembler::Fail;
4430 
4431   return S;
4432 }
4433 
4434 template<int shift>
4435 static DecodeStatus DecodeMveAddrModeQ(MCInst &Inst, unsigned Insn,
4436                              uint64_t Address, const void *Decoder) {
4437   DecodeStatus S = MCDisassembler::Success;
4438   unsigned Qm = fieldFromInstruction(Insn, 8, 3);
4439   int imm = fieldFromInstruction(Insn, 0, 7);
4440 
4441   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
4442     return MCDisassembler::Fail;
4443 
4444   if(!fieldFromInstruction(Insn, 7, 1)) {
4445     if (imm == 0)
4446       imm = INT32_MIN;                 // indicate -0
4447     else
4448       imm *= -1;
4449   }
4450   if (imm != INT32_MIN)
4451     imm <<= shift;
4452   Inst.addOperand(MCOperand::createImm(imm));
4453 
4454   return S;
4455 }
4456 
4457 static DecodeStatus DecodeThumbBLXOffset(MCInst &Inst, unsigned Val,
4458                                  uint64_t Address, const void *Decoder) {
4459   // Val is passed in as S:J1:J2:imm10H:imm10L:'0'
4460   // Note only one trailing zero not two.  Also the J1 and J2 values are from
4461   // the encoded instruction.  So here change to I1 and I2 values via:
4462   // I1 = NOT(J1 EOR S);
4463   // I2 = NOT(J2 EOR S);
4464   // and build the imm32 with two trailing zeros as documented:
4465   // imm32 = SignExtend(S:I1:I2:imm10H:imm10L:'00', 32);
4466   unsigned S = (Val >> 23) & 1;
4467   unsigned J1 = (Val >> 22) & 1;
4468   unsigned J2 = (Val >> 21) & 1;
4469   unsigned I1 = !(J1 ^ S);
4470   unsigned I2 = !(J2 ^ S);
4471   unsigned tmp = (Val & ~0x600000) | (I1 << 22) | (I2 << 21);
4472   int imm32 = SignExtend32<25>(tmp << 1);
4473 
4474   if (!tryAddingSymbolicOperand(Address,
4475                                 (Address & ~2u) + imm32 + 4,
4476                                 true, 4, Inst, Decoder))
4477     Inst.addOperand(MCOperand::createImm(imm32));
4478   return MCDisassembler::Success;
4479 }
4480 
4481 static DecodeStatus DecodeCoprocessor(MCInst &Inst, unsigned Val,
4482                               uint64_t Address, const void *Decoder) {
4483   if (Val == 0xA || Val == 0xB)
4484     return MCDisassembler::Fail;
4485 
4486   const FeatureBitset &featureBits =
4487     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4488 
4489   if (featureBits[ARM::HasV8Ops] && !(Val == 14 || Val == 15))
4490     return MCDisassembler::Fail;
4491 
4492   // For Armv8.1-M Mainline coprocessors matching 100x,101x or 111x should
4493   // decode as VFP/MVE instructions.
4494   if (featureBits[ARM::HasV8_1MMainlineOps] &&
4495       ((Val & 0xE) == 0x8 || (Val & 0xE) == 0xA ||
4496        (Val & 0xE) == 0xE))
4497     return MCDisassembler::Fail;
4498 
4499   Inst.addOperand(MCOperand::createImm(Val));
4500   return MCDisassembler::Success;
4501 }
4502 
4503 static DecodeStatus
4504 DecodeThumbTableBranch(MCInst &Inst, unsigned Insn,
4505                        uint64_t Address, const void *Decoder) {
4506   DecodeStatus S = MCDisassembler::Success;
4507 
4508   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4509   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4510 
4511   if (Rn == ARM::SP) S = MCDisassembler::SoftFail;
4512   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4513     return MCDisassembler::Fail;
4514   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
4515     return MCDisassembler::Fail;
4516   return S;
4517 }
4518 
4519 static DecodeStatus
4520 DecodeThumb2BCCInstruction(MCInst &Inst, unsigned Insn,
4521                            uint64_t Address, const void *Decoder) {
4522   DecodeStatus S = MCDisassembler::Success;
4523 
4524   unsigned pred = fieldFromInstruction(Insn, 22, 4);
4525   if (pred == 0xE || pred == 0xF) {
4526     unsigned opc = fieldFromInstruction(Insn, 4, 28);
4527     switch (opc) {
4528       default:
4529         return MCDisassembler::Fail;
4530       case 0xf3bf8f4:
4531         Inst.setOpcode(ARM::t2DSB);
4532         break;
4533       case 0xf3bf8f5:
4534         Inst.setOpcode(ARM::t2DMB);
4535         break;
4536       case 0xf3bf8f6:
4537         Inst.setOpcode(ARM::t2ISB);
4538         break;
4539     }
4540 
4541     unsigned imm = fieldFromInstruction(Insn, 0, 4);
4542     return DecodeMemBarrierOption(Inst, imm, Address, Decoder);
4543   }
4544 
4545   unsigned brtarget = fieldFromInstruction(Insn, 0, 11) << 1;
4546   brtarget |= fieldFromInstruction(Insn, 11, 1) << 19;
4547   brtarget |= fieldFromInstruction(Insn, 13, 1) << 18;
4548   brtarget |= fieldFromInstruction(Insn, 16, 6) << 12;
4549   brtarget |= fieldFromInstruction(Insn, 26, 1) << 20;
4550 
4551   if (!Check(S, DecodeT2BROperand(Inst, brtarget, Address, Decoder)))
4552     return MCDisassembler::Fail;
4553   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4554     return MCDisassembler::Fail;
4555 
4556   return S;
4557 }
4558 
4559 // Decode a shifted immediate operand.  These basically consist
4560 // of an 8-bit value, and a 4-bit directive that specifies either
4561 // a splat operation or a rotation.
4562 static DecodeStatus DecodeT2SOImm(MCInst &Inst, unsigned Val,
4563                           uint64_t Address, const void *Decoder) {
4564   unsigned ctrl = fieldFromInstruction(Val, 10, 2);
4565   if (ctrl == 0) {
4566     unsigned byte = fieldFromInstruction(Val, 8, 2);
4567     unsigned imm = fieldFromInstruction(Val, 0, 8);
4568     switch (byte) {
4569       case 0:
4570         Inst.addOperand(MCOperand::createImm(imm));
4571         break;
4572       case 1:
4573         Inst.addOperand(MCOperand::createImm((imm << 16) | imm));
4574         break;
4575       case 2:
4576         Inst.addOperand(MCOperand::createImm((imm << 24) | (imm << 8)));
4577         break;
4578       case 3:
4579         Inst.addOperand(MCOperand::createImm((imm << 24) | (imm << 16) |
4580                                              (imm << 8)  |  imm));
4581         break;
4582     }
4583   } else {
4584     unsigned unrot = fieldFromInstruction(Val, 0, 7) | 0x80;
4585     unsigned rot = fieldFromInstruction(Val, 7, 5);
4586     unsigned imm = (unrot >> rot) | (unrot << ((32-rot)&31));
4587     Inst.addOperand(MCOperand::createImm(imm));
4588   }
4589 
4590   return MCDisassembler::Success;
4591 }
4592 
4593 static DecodeStatus
4594 DecodeThumbBCCTargetOperand(MCInst &Inst, unsigned Val,
4595                             uint64_t Address, const void *Decoder) {
4596   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<9>(Val<<1) + 4,
4597                                 true, 2, Inst, Decoder))
4598     Inst.addOperand(MCOperand::createImm(SignExtend32<9>(Val << 1)));
4599   return MCDisassembler::Success;
4600 }
4601 
4602 static DecodeStatus DecodeThumbBLTargetOperand(MCInst &Inst, unsigned Val,
4603                                                uint64_t Address,
4604                                                const void *Decoder) {
4605   // Val is passed in as S:J1:J2:imm10:imm11
4606   // Note no trailing zero after imm11.  Also the J1 and J2 values are from
4607   // the encoded instruction.  So here change to I1 and I2 values via:
4608   // I1 = NOT(J1 EOR S);
4609   // I2 = NOT(J2 EOR S);
4610   // and build the imm32 with one trailing zero as documented:
4611   // imm32 = SignExtend(S:I1:I2:imm10:imm11:'0', 32);
4612   unsigned S = (Val >> 23) & 1;
4613   unsigned J1 = (Val >> 22) & 1;
4614   unsigned J2 = (Val >> 21) & 1;
4615   unsigned I1 = !(J1 ^ S);
4616   unsigned I2 = !(J2 ^ S);
4617   unsigned tmp = (Val & ~0x600000) | (I1 << 22) | (I2 << 21);
4618   int imm32 = SignExtend32<25>(tmp << 1);
4619 
4620   if (!tryAddingSymbolicOperand(Address, Address + imm32 + 4,
4621                                 true, 4, Inst, Decoder))
4622     Inst.addOperand(MCOperand::createImm(imm32));
4623   return MCDisassembler::Success;
4624 }
4625 
4626 static DecodeStatus DecodeMemBarrierOption(MCInst &Inst, unsigned Val,
4627                                    uint64_t Address, const void *Decoder) {
4628   if (Val & ~0xf)
4629     return MCDisassembler::Fail;
4630 
4631   Inst.addOperand(MCOperand::createImm(Val));
4632   return MCDisassembler::Success;
4633 }
4634 
4635 static DecodeStatus DecodeInstSyncBarrierOption(MCInst &Inst, unsigned Val,
4636                                         uint64_t Address, const void *Decoder) {
4637   if (Val & ~0xf)
4638     return MCDisassembler::Fail;
4639 
4640   Inst.addOperand(MCOperand::createImm(Val));
4641   return MCDisassembler::Success;
4642 }
4643 
4644 static DecodeStatus DecodeMSRMask(MCInst &Inst, unsigned Val,
4645                           uint64_t Address, const void *Decoder) {
4646   DecodeStatus S = MCDisassembler::Success;
4647   const FeatureBitset &FeatureBits =
4648     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4649 
4650   if (FeatureBits[ARM::FeatureMClass]) {
4651     unsigned ValLow = Val & 0xff;
4652 
4653     // Validate the SYSm value first.
4654     switch (ValLow) {
4655     case  0: // apsr
4656     case  1: // iapsr
4657     case  2: // eapsr
4658     case  3: // xpsr
4659     case  5: // ipsr
4660     case  6: // epsr
4661     case  7: // iepsr
4662     case  8: // msp
4663     case  9: // psp
4664     case 16: // primask
4665     case 20: // control
4666       break;
4667     case 17: // basepri
4668     case 18: // basepri_max
4669     case 19: // faultmask
4670       if (!(FeatureBits[ARM::HasV7Ops]))
4671         // Values basepri, basepri_max and faultmask are only valid for v7m.
4672         return MCDisassembler::Fail;
4673       break;
4674     case 0x8a: // msplim_ns
4675     case 0x8b: // psplim_ns
4676     case 0x91: // basepri_ns
4677     case 0x93: // faultmask_ns
4678       if (!(FeatureBits[ARM::HasV8MMainlineOps]))
4679         return MCDisassembler::Fail;
4680       LLVM_FALLTHROUGH;
4681     case 10:   // msplim
4682     case 11:   // psplim
4683     case 0x88: // msp_ns
4684     case 0x89: // psp_ns
4685     case 0x90: // primask_ns
4686     case 0x94: // control_ns
4687     case 0x98: // sp_ns
4688       if (!(FeatureBits[ARM::Feature8MSecExt]))
4689         return MCDisassembler::Fail;
4690       break;
4691     default:
4692       // Architecturally defined as unpredictable
4693       S = MCDisassembler::SoftFail;
4694       break;
4695     }
4696 
4697     if (Inst.getOpcode() == ARM::t2MSR_M) {
4698       unsigned Mask = fieldFromInstruction(Val, 10, 2);
4699       if (!(FeatureBits[ARM::HasV7Ops])) {
4700         // The ARMv6-M MSR bits {11-10} can be only 0b10, other values are
4701         // unpredictable.
4702         if (Mask != 2)
4703           S = MCDisassembler::SoftFail;
4704       }
4705       else {
4706         // The ARMv7-M architecture stores an additional 2-bit mask value in
4707         // MSR bits {11-10}. The mask is used only with apsr, iapsr, eapsr and
4708         // xpsr, it has to be 0b10 in other cases. Bit mask{1} indicates if
4709         // the NZCVQ bits should be moved by the instruction. Bit mask{0}
4710         // indicates the move for the GE{3:0} bits, the mask{0} bit can be set
4711         // only if the processor includes the DSP extension.
4712         if (Mask == 0 || (Mask != 2 && ValLow > 3) ||
4713             (!(FeatureBits[ARM::FeatureDSP]) && (Mask & 1)))
4714           S = MCDisassembler::SoftFail;
4715       }
4716     }
4717   } else {
4718     // A/R class
4719     if (Val == 0)
4720       return MCDisassembler::Fail;
4721   }
4722   Inst.addOperand(MCOperand::createImm(Val));
4723   return S;
4724 }
4725 
4726 static DecodeStatus DecodeBankedReg(MCInst &Inst, unsigned Val,
4727                                     uint64_t Address, const void *Decoder) {
4728   unsigned R = fieldFromInstruction(Val, 5, 1);
4729   unsigned SysM = fieldFromInstruction(Val, 0, 5);
4730 
4731   // The table of encodings for these banked registers comes from B9.2.3 of the
4732   // ARM ARM. There are patterns, but nothing regular enough to make this logic
4733   // neater. So by fiat, these values are UNPREDICTABLE:
4734   if (!ARMBankedReg::lookupBankedRegByEncoding((R << 5) | SysM))
4735     return MCDisassembler::Fail;
4736 
4737   Inst.addOperand(MCOperand::createImm(Val));
4738   return MCDisassembler::Success;
4739 }
4740 
4741 static DecodeStatus DecodeDoubleRegLoad(MCInst &Inst, unsigned Insn,
4742                                         uint64_t Address, const void *Decoder) {
4743   DecodeStatus S = MCDisassembler::Success;
4744 
4745   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4746   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4747   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4748 
4749   if (Rn == 0xF)
4750     S = MCDisassembler::SoftFail;
4751 
4752   if (!Check(S, DecodeGPRPairRegisterClass(Inst, Rt, Address, Decoder)))
4753     return MCDisassembler::Fail;
4754   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4755     return MCDisassembler::Fail;
4756   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4757     return MCDisassembler::Fail;
4758 
4759   return S;
4760 }
4761 
4762 static DecodeStatus DecodeDoubleRegStore(MCInst &Inst, unsigned Insn,
4763                                          uint64_t Address,
4764                                          const void *Decoder) {
4765   DecodeStatus S = MCDisassembler::Success;
4766 
4767   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4768   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
4769   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4770   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4771 
4772   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
4773     return MCDisassembler::Fail;
4774 
4775   if (Rn == 0xF || Rd == Rn || Rd == Rt || Rd == Rt+1)
4776     S = MCDisassembler::SoftFail;
4777 
4778   if (!Check(S, DecodeGPRPairRegisterClass(Inst, Rt, Address, Decoder)))
4779     return MCDisassembler::Fail;
4780   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4781     return MCDisassembler::Fail;
4782   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4783     return MCDisassembler::Fail;
4784 
4785   return S;
4786 }
4787 
4788 static DecodeStatus DecodeLDRPreImm(MCInst &Inst, unsigned Insn,
4789                             uint64_t Address, const void *Decoder) {
4790   DecodeStatus S = MCDisassembler::Success;
4791 
4792   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4793   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4794   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4795   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4796   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4797   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4798 
4799   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4800 
4801   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4802     return MCDisassembler::Fail;
4803   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4804     return MCDisassembler::Fail;
4805   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
4806     return MCDisassembler::Fail;
4807   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4808     return MCDisassembler::Fail;
4809 
4810   return S;
4811 }
4812 
4813 static DecodeStatus DecodeLDRPreReg(MCInst &Inst, unsigned Insn,
4814                             uint64_t Address, const void *Decoder) {
4815   DecodeStatus S = MCDisassembler::Success;
4816 
4817   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4818   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4819   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4820   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4821   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4822   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4823   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4824 
4825   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4826   if (Rm == 0xF) S = MCDisassembler::SoftFail;
4827 
4828   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4829     return MCDisassembler::Fail;
4830   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4831     return MCDisassembler::Fail;
4832   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
4833     return MCDisassembler::Fail;
4834   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4835     return MCDisassembler::Fail;
4836 
4837   return S;
4838 }
4839 
4840 static DecodeStatus DecodeSTRPreImm(MCInst &Inst, unsigned Insn,
4841                             uint64_t Address, const void *Decoder) {
4842   DecodeStatus S = MCDisassembler::Success;
4843 
4844   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4845   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4846   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4847   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4848   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4849   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4850 
4851   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4852 
4853   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4854     return MCDisassembler::Fail;
4855   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4856     return MCDisassembler::Fail;
4857   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
4858     return MCDisassembler::Fail;
4859   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4860     return MCDisassembler::Fail;
4861 
4862   return S;
4863 }
4864 
4865 static DecodeStatus DecodeSTRPreReg(MCInst &Inst, unsigned Insn,
4866                             uint64_t Address, const void *Decoder) {
4867   DecodeStatus S = MCDisassembler::Success;
4868 
4869   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4870   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4871   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4872   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4873   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4874   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4875 
4876   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4877 
4878   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4879     return MCDisassembler::Fail;
4880   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4881     return MCDisassembler::Fail;
4882   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
4883     return MCDisassembler::Fail;
4884   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4885     return MCDisassembler::Fail;
4886 
4887   return S;
4888 }
4889 
4890 static DecodeStatus DecodeVLD1LN(MCInst &Inst, unsigned Insn,
4891                          uint64_t Address, const void *Decoder) {
4892   DecodeStatus S = MCDisassembler::Success;
4893 
4894   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4895   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4896   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4897   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4898   unsigned size = fieldFromInstruction(Insn, 10, 2);
4899 
4900   unsigned align = 0;
4901   unsigned index = 0;
4902   switch (size) {
4903     default:
4904       return MCDisassembler::Fail;
4905     case 0:
4906       if (fieldFromInstruction(Insn, 4, 1))
4907         return MCDisassembler::Fail; // UNDEFINED
4908       index = fieldFromInstruction(Insn, 5, 3);
4909       break;
4910     case 1:
4911       if (fieldFromInstruction(Insn, 5, 1))
4912         return MCDisassembler::Fail; // UNDEFINED
4913       index = fieldFromInstruction(Insn, 6, 2);
4914       if (fieldFromInstruction(Insn, 4, 1))
4915         align = 2;
4916       break;
4917     case 2:
4918       if (fieldFromInstruction(Insn, 6, 1))
4919         return MCDisassembler::Fail; // UNDEFINED
4920       index = fieldFromInstruction(Insn, 7, 1);
4921 
4922       switch (fieldFromInstruction(Insn, 4, 2)) {
4923         case 0 :
4924           align = 0; break;
4925         case 3:
4926           align = 4; break;
4927         default:
4928           return MCDisassembler::Fail;
4929       }
4930       break;
4931   }
4932 
4933   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4934     return MCDisassembler::Fail;
4935   if (Rm != 0xF) { // Writeback
4936     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4937       return MCDisassembler::Fail;
4938   }
4939   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4940     return MCDisassembler::Fail;
4941   Inst.addOperand(MCOperand::createImm(align));
4942   if (Rm != 0xF) {
4943     if (Rm != 0xD) {
4944       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4945         return MCDisassembler::Fail;
4946     } else
4947       Inst.addOperand(MCOperand::createReg(0));
4948   }
4949 
4950   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4951     return MCDisassembler::Fail;
4952   Inst.addOperand(MCOperand::createImm(index));
4953 
4954   return S;
4955 }
4956 
4957 static DecodeStatus DecodeVST1LN(MCInst &Inst, unsigned Insn,
4958                          uint64_t Address, const void *Decoder) {
4959   DecodeStatus S = MCDisassembler::Success;
4960 
4961   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4962   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4963   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4964   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4965   unsigned size = fieldFromInstruction(Insn, 10, 2);
4966 
4967   unsigned align = 0;
4968   unsigned index = 0;
4969   switch (size) {
4970     default:
4971       return MCDisassembler::Fail;
4972     case 0:
4973       if (fieldFromInstruction(Insn, 4, 1))
4974         return MCDisassembler::Fail; // UNDEFINED
4975       index = fieldFromInstruction(Insn, 5, 3);
4976       break;
4977     case 1:
4978       if (fieldFromInstruction(Insn, 5, 1))
4979         return MCDisassembler::Fail; // UNDEFINED
4980       index = fieldFromInstruction(Insn, 6, 2);
4981       if (fieldFromInstruction(Insn, 4, 1))
4982         align = 2;
4983       break;
4984     case 2:
4985       if (fieldFromInstruction(Insn, 6, 1))
4986         return MCDisassembler::Fail; // UNDEFINED
4987       index = fieldFromInstruction(Insn, 7, 1);
4988 
4989       switch (fieldFromInstruction(Insn, 4, 2)) {
4990         case 0:
4991           align = 0; break;
4992         case 3:
4993           align = 4; break;
4994         default:
4995           return MCDisassembler::Fail;
4996       }
4997       break;
4998   }
4999 
5000   if (Rm != 0xF) { // Writeback
5001     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5002     return MCDisassembler::Fail;
5003   }
5004   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5005     return MCDisassembler::Fail;
5006   Inst.addOperand(MCOperand::createImm(align));
5007   if (Rm != 0xF) {
5008     if (Rm != 0xD) {
5009       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5010     return MCDisassembler::Fail;
5011     } else
5012       Inst.addOperand(MCOperand::createReg(0));
5013   }
5014 
5015   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5016     return MCDisassembler::Fail;
5017   Inst.addOperand(MCOperand::createImm(index));
5018 
5019   return S;
5020 }
5021 
5022 static DecodeStatus DecodeVLD2LN(MCInst &Inst, unsigned Insn,
5023                          uint64_t Address, const void *Decoder) {
5024   DecodeStatus S = MCDisassembler::Success;
5025 
5026   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5027   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5028   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5029   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5030   unsigned size = fieldFromInstruction(Insn, 10, 2);
5031 
5032   unsigned align = 0;
5033   unsigned index = 0;
5034   unsigned inc = 1;
5035   switch (size) {
5036     default:
5037       return MCDisassembler::Fail;
5038     case 0:
5039       index = fieldFromInstruction(Insn, 5, 3);
5040       if (fieldFromInstruction(Insn, 4, 1))
5041         align = 2;
5042       break;
5043     case 1:
5044       index = fieldFromInstruction(Insn, 6, 2);
5045       if (fieldFromInstruction(Insn, 4, 1))
5046         align = 4;
5047       if (fieldFromInstruction(Insn, 5, 1))
5048         inc = 2;
5049       break;
5050     case 2:
5051       if (fieldFromInstruction(Insn, 5, 1))
5052         return MCDisassembler::Fail; // UNDEFINED
5053       index = fieldFromInstruction(Insn, 7, 1);
5054       if (fieldFromInstruction(Insn, 4, 1) != 0)
5055         align = 8;
5056       if (fieldFromInstruction(Insn, 6, 1))
5057         inc = 2;
5058       break;
5059   }
5060 
5061   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5062     return MCDisassembler::Fail;
5063   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5064     return MCDisassembler::Fail;
5065   if (Rm != 0xF) { // Writeback
5066     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5067       return MCDisassembler::Fail;
5068   }
5069   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5070     return MCDisassembler::Fail;
5071   Inst.addOperand(MCOperand::createImm(align));
5072   if (Rm != 0xF) {
5073     if (Rm != 0xD) {
5074       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5075         return MCDisassembler::Fail;
5076     } else
5077       Inst.addOperand(MCOperand::createReg(0));
5078   }
5079 
5080   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5081     return MCDisassembler::Fail;
5082   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5083     return MCDisassembler::Fail;
5084   Inst.addOperand(MCOperand::createImm(index));
5085 
5086   return S;
5087 }
5088 
5089 static DecodeStatus DecodeVST2LN(MCInst &Inst, unsigned Insn,
5090                          uint64_t Address, const void *Decoder) {
5091   DecodeStatus S = MCDisassembler::Success;
5092 
5093   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5094   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5095   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5096   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5097   unsigned size = fieldFromInstruction(Insn, 10, 2);
5098 
5099   unsigned align = 0;
5100   unsigned index = 0;
5101   unsigned inc = 1;
5102   switch (size) {
5103     default:
5104       return MCDisassembler::Fail;
5105     case 0:
5106       index = fieldFromInstruction(Insn, 5, 3);
5107       if (fieldFromInstruction(Insn, 4, 1))
5108         align = 2;
5109       break;
5110     case 1:
5111       index = fieldFromInstruction(Insn, 6, 2);
5112       if (fieldFromInstruction(Insn, 4, 1))
5113         align = 4;
5114       if (fieldFromInstruction(Insn, 5, 1))
5115         inc = 2;
5116       break;
5117     case 2:
5118       if (fieldFromInstruction(Insn, 5, 1))
5119         return MCDisassembler::Fail; // UNDEFINED
5120       index = fieldFromInstruction(Insn, 7, 1);
5121       if (fieldFromInstruction(Insn, 4, 1) != 0)
5122         align = 8;
5123       if (fieldFromInstruction(Insn, 6, 1))
5124         inc = 2;
5125       break;
5126   }
5127 
5128   if (Rm != 0xF) { // Writeback
5129     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5130       return MCDisassembler::Fail;
5131   }
5132   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5133     return MCDisassembler::Fail;
5134   Inst.addOperand(MCOperand::createImm(align));
5135   if (Rm != 0xF) {
5136     if (Rm != 0xD) {
5137       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5138         return MCDisassembler::Fail;
5139     } else
5140       Inst.addOperand(MCOperand::createReg(0));
5141   }
5142 
5143   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5144     return MCDisassembler::Fail;
5145   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5146     return MCDisassembler::Fail;
5147   Inst.addOperand(MCOperand::createImm(index));
5148 
5149   return S;
5150 }
5151 
5152 static DecodeStatus DecodeVLD3LN(MCInst &Inst, unsigned Insn,
5153                          uint64_t Address, const void *Decoder) {
5154   DecodeStatus S = MCDisassembler::Success;
5155 
5156   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5157   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5158   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5159   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5160   unsigned size = fieldFromInstruction(Insn, 10, 2);
5161 
5162   unsigned align = 0;
5163   unsigned index = 0;
5164   unsigned inc = 1;
5165   switch (size) {
5166     default:
5167       return MCDisassembler::Fail;
5168     case 0:
5169       if (fieldFromInstruction(Insn, 4, 1))
5170         return MCDisassembler::Fail; // UNDEFINED
5171       index = fieldFromInstruction(Insn, 5, 3);
5172       break;
5173     case 1:
5174       if (fieldFromInstruction(Insn, 4, 1))
5175         return MCDisassembler::Fail; // UNDEFINED
5176       index = fieldFromInstruction(Insn, 6, 2);
5177       if (fieldFromInstruction(Insn, 5, 1))
5178         inc = 2;
5179       break;
5180     case 2:
5181       if (fieldFromInstruction(Insn, 4, 2))
5182         return MCDisassembler::Fail; // UNDEFINED
5183       index = fieldFromInstruction(Insn, 7, 1);
5184       if (fieldFromInstruction(Insn, 6, 1))
5185         inc = 2;
5186       break;
5187   }
5188 
5189   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5190     return MCDisassembler::Fail;
5191   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5192     return MCDisassembler::Fail;
5193   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5194     return MCDisassembler::Fail;
5195 
5196   if (Rm != 0xF) { // Writeback
5197     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5198     return MCDisassembler::Fail;
5199   }
5200   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5201     return MCDisassembler::Fail;
5202   Inst.addOperand(MCOperand::createImm(align));
5203   if (Rm != 0xF) {
5204     if (Rm != 0xD) {
5205       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5206     return MCDisassembler::Fail;
5207     } else
5208       Inst.addOperand(MCOperand::createReg(0));
5209   }
5210 
5211   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5212     return MCDisassembler::Fail;
5213   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5214     return MCDisassembler::Fail;
5215   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5216     return MCDisassembler::Fail;
5217   Inst.addOperand(MCOperand::createImm(index));
5218 
5219   return S;
5220 }
5221 
5222 static DecodeStatus DecodeVST3LN(MCInst &Inst, unsigned Insn,
5223                          uint64_t Address, const void *Decoder) {
5224   DecodeStatus S = MCDisassembler::Success;
5225 
5226   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5227   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5228   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5229   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5230   unsigned size = fieldFromInstruction(Insn, 10, 2);
5231 
5232   unsigned align = 0;
5233   unsigned index = 0;
5234   unsigned inc = 1;
5235   switch (size) {
5236     default:
5237       return MCDisassembler::Fail;
5238     case 0:
5239       if (fieldFromInstruction(Insn, 4, 1))
5240         return MCDisassembler::Fail; // UNDEFINED
5241       index = fieldFromInstruction(Insn, 5, 3);
5242       break;
5243     case 1:
5244       if (fieldFromInstruction(Insn, 4, 1))
5245         return MCDisassembler::Fail; // UNDEFINED
5246       index = fieldFromInstruction(Insn, 6, 2);
5247       if (fieldFromInstruction(Insn, 5, 1))
5248         inc = 2;
5249       break;
5250     case 2:
5251       if (fieldFromInstruction(Insn, 4, 2))
5252         return MCDisassembler::Fail; // UNDEFINED
5253       index = fieldFromInstruction(Insn, 7, 1);
5254       if (fieldFromInstruction(Insn, 6, 1))
5255         inc = 2;
5256       break;
5257   }
5258 
5259   if (Rm != 0xF) { // Writeback
5260     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5261     return MCDisassembler::Fail;
5262   }
5263   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5264     return MCDisassembler::Fail;
5265   Inst.addOperand(MCOperand::createImm(align));
5266   if (Rm != 0xF) {
5267     if (Rm != 0xD) {
5268       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5269     return MCDisassembler::Fail;
5270     } else
5271       Inst.addOperand(MCOperand::createReg(0));
5272   }
5273 
5274   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5275     return MCDisassembler::Fail;
5276   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5277     return MCDisassembler::Fail;
5278   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5279     return MCDisassembler::Fail;
5280   Inst.addOperand(MCOperand::createImm(index));
5281 
5282   return S;
5283 }
5284 
5285 static DecodeStatus DecodeVLD4LN(MCInst &Inst, unsigned Insn,
5286                          uint64_t Address, const void *Decoder) {
5287   DecodeStatus S = MCDisassembler::Success;
5288 
5289   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5290   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5291   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5292   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5293   unsigned size = fieldFromInstruction(Insn, 10, 2);
5294 
5295   unsigned align = 0;
5296   unsigned index = 0;
5297   unsigned inc = 1;
5298   switch (size) {
5299     default:
5300       return MCDisassembler::Fail;
5301     case 0:
5302       if (fieldFromInstruction(Insn, 4, 1))
5303         align = 4;
5304       index = fieldFromInstruction(Insn, 5, 3);
5305       break;
5306     case 1:
5307       if (fieldFromInstruction(Insn, 4, 1))
5308         align = 8;
5309       index = fieldFromInstruction(Insn, 6, 2);
5310       if (fieldFromInstruction(Insn, 5, 1))
5311         inc = 2;
5312       break;
5313     case 2:
5314       switch (fieldFromInstruction(Insn, 4, 2)) {
5315         case 0:
5316           align = 0; break;
5317         case 3:
5318           return MCDisassembler::Fail;
5319         default:
5320           align = 4 << fieldFromInstruction(Insn, 4, 2); break;
5321       }
5322 
5323       index = fieldFromInstruction(Insn, 7, 1);
5324       if (fieldFromInstruction(Insn, 6, 1))
5325         inc = 2;
5326       break;
5327   }
5328 
5329   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5330     return MCDisassembler::Fail;
5331   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5332     return MCDisassembler::Fail;
5333   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5334     return MCDisassembler::Fail;
5335   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5336     return MCDisassembler::Fail;
5337 
5338   if (Rm != 0xF) { // Writeback
5339     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5340       return MCDisassembler::Fail;
5341   }
5342   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5343     return MCDisassembler::Fail;
5344   Inst.addOperand(MCOperand::createImm(align));
5345   if (Rm != 0xF) {
5346     if (Rm != 0xD) {
5347       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5348         return MCDisassembler::Fail;
5349     } else
5350       Inst.addOperand(MCOperand::createReg(0));
5351   }
5352 
5353   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5354     return MCDisassembler::Fail;
5355   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5356     return MCDisassembler::Fail;
5357   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5358     return MCDisassembler::Fail;
5359   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5360     return MCDisassembler::Fail;
5361   Inst.addOperand(MCOperand::createImm(index));
5362 
5363   return S;
5364 }
5365 
5366 static DecodeStatus DecodeVST4LN(MCInst &Inst, unsigned Insn,
5367                          uint64_t Address, const void *Decoder) {
5368   DecodeStatus S = MCDisassembler::Success;
5369 
5370   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5371   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5372   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5373   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5374   unsigned size = fieldFromInstruction(Insn, 10, 2);
5375 
5376   unsigned align = 0;
5377   unsigned index = 0;
5378   unsigned inc = 1;
5379   switch (size) {
5380     default:
5381       return MCDisassembler::Fail;
5382     case 0:
5383       if (fieldFromInstruction(Insn, 4, 1))
5384         align = 4;
5385       index = fieldFromInstruction(Insn, 5, 3);
5386       break;
5387     case 1:
5388       if (fieldFromInstruction(Insn, 4, 1))
5389         align = 8;
5390       index = fieldFromInstruction(Insn, 6, 2);
5391       if (fieldFromInstruction(Insn, 5, 1))
5392         inc = 2;
5393       break;
5394     case 2:
5395       switch (fieldFromInstruction(Insn, 4, 2)) {
5396         case 0:
5397           align = 0; break;
5398         case 3:
5399           return MCDisassembler::Fail;
5400         default:
5401           align = 4 << fieldFromInstruction(Insn, 4, 2); break;
5402       }
5403 
5404       index = fieldFromInstruction(Insn, 7, 1);
5405       if (fieldFromInstruction(Insn, 6, 1))
5406         inc = 2;
5407       break;
5408   }
5409 
5410   if (Rm != 0xF) { // Writeback
5411     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5412     return MCDisassembler::Fail;
5413   }
5414   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5415     return MCDisassembler::Fail;
5416   Inst.addOperand(MCOperand::createImm(align));
5417   if (Rm != 0xF) {
5418     if (Rm != 0xD) {
5419       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5420     return MCDisassembler::Fail;
5421     } else
5422       Inst.addOperand(MCOperand::createReg(0));
5423   }
5424 
5425   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5426     return MCDisassembler::Fail;
5427   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5428     return MCDisassembler::Fail;
5429   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5430     return MCDisassembler::Fail;
5431   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5432     return MCDisassembler::Fail;
5433   Inst.addOperand(MCOperand::createImm(index));
5434 
5435   return S;
5436 }
5437 
5438 static DecodeStatus DecodeVMOVSRR(MCInst &Inst, unsigned Insn,
5439                                   uint64_t Address, const void *Decoder) {
5440   DecodeStatus S = MCDisassembler::Success;
5441   unsigned Rt  = fieldFromInstruction(Insn, 12, 4);
5442   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
5443   unsigned Rm  = fieldFromInstruction(Insn,  5, 1);
5444   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5445   Rm |= fieldFromInstruction(Insn, 0, 4) << 1;
5446 
5447   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
5448     S = MCDisassembler::SoftFail;
5449 
5450   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
5451     return MCDisassembler::Fail;
5452   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
5453     return MCDisassembler::Fail;
5454   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
5455     return MCDisassembler::Fail;
5456   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
5457     return MCDisassembler::Fail;
5458   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5459     return MCDisassembler::Fail;
5460 
5461   return S;
5462 }
5463 
5464 static DecodeStatus DecodeVMOVRRS(MCInst &Inst, unsigned Insn,
5465                                   uint64_t Address, const void *Decoder) {
5466   DecodeStatus S = MCDisassembler::Success;
5467   unsigned Rt  = fieldFromInstruction(Insn, 12, 4);
5468   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
5469   unsigned Rm  = fieldFromInstruction(Insn,  5, 1);
5470   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5471   Rm |= fieldFromInstruction(Insn, 0, 4) << 1;
5472 
5473   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
5474     S = MCDisassembler::SoftFail;
5475 
5476   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
5477     return MCDisassembler::Fail;
5478   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
5479     return MCDisassembler::Fail;
5480   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
5481     return MCDisassembler::Fail;
5482   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
5483     return MCDisassembler::Fail;
5484   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5485     return MCDisassembler::Fail;
5486 
5487   return S;
5488 }
5489 
5490 static DecodeStatus DecodeIT(MCInst &Inst, unsigned Insn,
5491                              uint64_t Address, const void *Decoder) {
5492   DecodeStatus S = MCDisassembler::Success;
5493   unsigned pred = fieldFromInstruction(Insn, 4, 4);
5494   unsigned mask = fieldFromInstruction(Insn, 0, 4);
5495 
5496   if (pred == 0xF) {
5497     pred = 0xE;
5498     S = MCDisassembler::SoftFail;
5499   }
5500 
5501   if (mask == 0x0)
5502     return MCDisassembler::Fail;
5503 
5504   // IT masks are encoded as a sequence of replacement low-order bits
5505   // for the condition code. So if the low bit of the starting
5506   // condition code is 1, then we have to flip all the bits above the
5507   // terminating bit (which is the lowest 1 bit).
5508   if (pred & 1) {
5509     unsigned LowBit = mask & -mask;
5510     unsigned BitsAboveLowBit = 0xF & (-LowBit << 1);
5511     mask ^= BitsAboveLowBit;
5512   }
5513 
5514   Inst.addOperand(MCOperand::createImm(pred));
5515   Inst.addOperand(MCOperand::createImm(mask));
5516   return S;
5517 }
5518 
5519 static DecodeStatus
5520 DecodeT2LDRDPreInstruction(MCInst &Inst, unsigned Insn,
5521                            uint64_t Address, const void *Decoder) {
5522   DecodeStatus S = MCDisassembler::Success;
5523 
5524   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5525   unsigned Rt2 = fieldFromInstruction(Insn, 8, 4);
5526   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5527   unsigned addr = fieldFromInstruction(Insn, 0, 8);
5528   unsigned W = fieldFromInstruction(Insn, 21, 1);
5529   unsigned U = fieldFromInstruction(Insn, 23, 1);
5530   unsigned P = fieldFromInstruction(Insn, 24, 1);
5531   bool writeback = (W == 1) | (P == 0);
5532 
5533   addr |= (U << 8) | (Rn << 9);
5534 
5535   if (writeback && (Rn == Rt || Rn == Rt2))
5536     Check(S, MCDisassembler::SoftFail);
5537   if (Rt == Rt2)
5538     Check(S, MCDisassembler::SoftFail);
5539 
5540   // Rt
5541   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
5542     return MCDisassembler::Fail;
5543   // Rt2
5544   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
5545     return MCDisassembler::Fail;
5546   // Writeback operand
5547   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
5548     return MCDisassembler::Fail;
5549   // addr
5550   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
5551     return MCDisassembler::Fail;
5552 
5553   return S;
5554 }
5555 
5556 static DecodeStatus
5557 DecodeT2STRDPreInstruction(MCInst &Inst, unsigned Insn,
5558                            uint64_t Address, const void *Decoder) {
5559   DecodeStatus S = MCDisassembler::Success;
5560 
5561   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5562   unsigned Rt2 = fieldFromInstruction(Insn, 8, 4);
5563   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5564   unsigned addr = fieldFromInstruction(Insn, 0, 8);
5565   unsigned W = fieldFromInstruction(Insn, 21, 1);
5566   unsigned U = fieldFromInstruction(Insn, 23, 1);
5567   unsigned P = fieldFromInstruction(Insn, 24, 1);
5568   bool writeback = (W == 1) | (P == 0);
5569 
5570   addr |= (U << 8) | (Rn << 9);
5571 
5572   if (writeback && (Rn == Rt || Rn == Rt2))
5573     Check(S, MCDisassembler::SoftFail);
5574 
5575   // Writeback operand
5576   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
5577     return MCDisassembler::Fail;
5578   // Rt
5579   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
5580     return MCDisassembler::Fail;
5581   // Rt2
5582   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
5583     return MCDisassembler::Fail;
5584   // addr
5585   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
5586     return MCDisassembler::Fail;
5587 
5588   return S;
5589 }
5590 
5591 static DecodeStatus DecodeT2Adr(MCInst &Inst, uint32_t Insn,
5592                                 uint64_t Address, const void *Decoder) {
5593   unsigned sign1 = fieldFromInstruction(Insn, 21, 1);
5594   unsigned sign2 = fieldFromInstruction(Insn, 23, 1);
5595   if (sign1 != sign2) return MCDisassembler::Fail;
5596 
5597   unsigned Val = fieldFromInstruction(Insn, 0, 8);
5598   Val |= fieldFromInstruction(Insn, 12, 3) << 8;
5599   Val |= fieldFromInstruction(Insn, 26, 1) << 11;
5600   Val |= sign1 << 12;
5601   Inst.addOperand(MCOperand::createImm(SignExtend32<13>(Val)));
5602 
5603   return MCDisassembler::Success;
5604 }
5605 
5606 static DecodeStatus DecodeT2ShifterImmOperand(MCInst &Inst, uint32_t Val,
5607                                               uint64_t Address,
5608                                               const void *Decoder) {
5609   DecodeStatus S = MCDisassembler::Success;
5610 
5611   // Shift of "asr #32" is not allowed in Thumb2 mode.
5612   if (Val == 0x20) S = MCDisassembler::Fail;
5613   Inst.addOperand(MCOperand::createImm(Val));
5614   return S;
5615 }
5616 
5617 static DecodeStatus DecodeSwap(MCInst &Inst, unsigned Insn,
5618                                uint64_t Address, const void *Decoder) {
5619   unsigned Rt   = fieldFromInstruction(Insn, 12, 4);
5620   unsigned Rt2  = fieldFromInstruction(Insn, 0,  4);
5621   unsigned Rn   = fieldFromInstruction(Insn, 16, 4);
5622   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5623 
5624   if (pred == 0xF)
5625     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
5626 
5627   DecodeStatus S = MCDisassembler::Success;
5628 
5629   if (Rt == Rn || Rn == Rt2)
5630     S = MCDisassembler::SoftFail;
5631 
5632   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5633     return MCDisassembler::Fail;
5634   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5635     return MCDisassembler::Fail;
5636   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
5637     return MCDisassembler::Fail;
5638   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5639     return MCDisassembler::Fail;
5640 
5641   return S;
5642 }
5643 
5644 static DecodeStatus DecodeVCVTD(MCInst &Inst, unsigned Insn,
5645                                 uint64_t Address, const void *Decoder) {
5646   const FeatureBitset &featureBits =
5647       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5648   bool hasFullFP16 = featureBits[ARM::FeatureFullFP16];
5649 
5650   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5651   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5652   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5653   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5654   unsigned imm = fieldFromInstruction(Insn, 16, 6);
5655   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
5656   unsigned op = fieldFromInstruction(Insn, 5, 1);
5657 
5658   DecodeStatus S = MCDisassembler::Success;
5659 
5660   // If the top 3 bits of imm are clear, this is a VMOV (immediate)
5661   if (!(imm & 0x38)) {
5662     if (cmode == 0xF) {
5663       if (op == 1) return MCDisassembler::Fail;
5664       Inst.setOpcode(ARM::VMOVv2f32);
5665     }
5666     if (hasFullFP16) {
5667       if (cmode == 0xE) {
5668         if (op == 1) {
5669           Inst.setOpcode(ARM::VMOVv1i64);
5670         } else {
5671           Inst.setOpcode(ARM::VMOVv8i8);
5672         }
5673       }
5674       if (cmode == 0xD) {
5675         if (op == 1) {
5676           Inst.setOpcode(ARM::VMVNv2i32);
5677         } else {
5678           Inst.setOpcode(ARM::VMOVv2i32);
5679         }
5680       }
5681       if (cmode == 0xC) {
5682         if (op == 1) {
5683           Inst.setOpcode(ARM::VMVNv2i32);
5684         } else {
5685           Inst.setOpcode(ARM::VMOVv2i32);
5686         }
5687       }
5688     }
5689     return DecodeNEONModImmInstruction(Inst, Insn, Address, Decoder);
5690   }
5691 
5692   if (!(imm & 0x20)) return MCDisassembler::Fail;
5693 
5694   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
5695     return MCDisassembler::Fail;
5696   if (!Check(S, DecodeDPRRegisterClass(Inst, Vm, Address, Decoder)))
5697     return MCDisassembler::Fail;
5698   Inst.addOperand(MCOperand::createImm(64 - imm));
5699 
5700   return S;
5701 }
5702 
5703 static DecodeStatus DecodeVCVTQ(MCInst &Inst, unsigned Insn,
5704                                 uint64_t Address, const void *Decoder) {
5705   const FeatureBitset &featureBits =
5706       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5707   bool hasFullFP16 = featureBits[ARM::FeatureFullFP16];
5708 
5709   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5710   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5711   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5712   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5713   unsigned imm = fieldFromInstruction(Insn, 16, 6);
5714   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
5715   unsigned op = fieldFromInstruction(Insn, 5, 1);
5716 
5717   DecodeStatus S = MCDisassembler::Success;
5718 
5719   // If the top 3 bits of imm are clear, this is a VMOV (immediate)
5720   if (!(imm & 0x38)) {
5721     if (cmode == 0xF) {
5722       if (op == 1) return MCDisassembler::Fail;
5723       Inst.setOpcode(ARM::VMOVv4f32);
5724     }
5725     if (hasFullFP16) {
5726       if (cmode == 0xE) {
5727         if (op == 1) {
5728           Inst.setOpcode(ARM::VMOVv2i64);
5729         } else {
5730           Inst.setOpcode(ARM::VMOVv16i8);
5731         }
5732       }
5733       if (cmode == 0xD) {
5734         if (op == 1) {
5735           Inst.setOpcode(ARM::VMVNv4i32);
5736         } else {
5737           Inst.setOpcode(ARM::VMOVv4i32);
5738         }
5739       }
5740       if (cmode == 0xC) {
5741         if (op == 1) {
5742           Inst.setOpcode(ARM::VMVNv4i32);
5743         } else {
5744           Inst.setOpcode(ARM::VMOVv4i32);
5745         }
5746       }
5747     }
5748     return DecodeNEONModImmInstruction(Inst, Insn, Address, Decoder);
5749   }
5750 
5751   if (!(imm & 0x20)) return MCDisassembler::Fail;
5752 
5753   if (!Check(S, DecodeQPRRegisterClass(Inst, Vd, Address, Decoder)))
5754     return MCDisassembler::Fail;
5755   if (!Check(S, DecodeQPRRegisterClass(Inst, Vm, Address, Decoder)))
5756     return MCDisassembler::Fail;
5757   Inst.addOperand(MCOperand::createImm(64 - imm));
5758 
5759   return S;
5760 }
5761 
5762 static DecodeStatus DecodeNEONComplexLane64Instruction(MCInst &Inst,
5763                                                        unsigned Insn,
5764                                                        uint64_t Address,
5765                                                        const void *Decoder) {
5766   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5767   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5768   unsigned Vn = (fieldFromInstruction(Insn, 16, 4) << 0);
5769   Vn |= (fieldFromInstruction(Insn, 7, 1) << 4);
5770   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5771   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5772   unsigned q = (fieldFromInstruction(Insn, 6, 1) << 0);
5773   unsigned rotate = (fieldFromInstruction(Insn, 20, 2) << 0);
5774 
5775   DecodeStatus S = MCDisassembler::Success;
5776 
5777   auto DestRegDecoder = q ? DecodeQPRRegisterClass : DecodeDPRRegisterClass;
5778 
5779   if (!Check(S, DestRegDecoder(Inst, Vd, Address, Decoder)))
5780     return MCDisassembler::Fail;
5781   if (!Check(S, DestRegDecoder(Inst, Vd, Address, Decoder)))
5782     return MCDisassembler::Fail;
5783   if (!Check(S, DestRegDecoder(Inst, Vn, Address, Decoder)))
5784     return MCDisassembler::Fail;
5785   if (!Check(S, DecodeDPRRegisterClass(Inst, Vm, Address, Decoder)))
5786     return MCDisassembler::Fail;
5787   // The lane index does not have any bits in the encoding, because it can only
5788   // be 0.
5789   Inst.addOperand(MCOperand::createImm(0));
5790   Inst.addOperand(MCOperand::createImm(rotate));
5791 
5792   return S;
5793 }
5794 
5795 static DecodeStatus DecodeLDR(MCInst &Inst, unsigned Val,
5796                                 uint64_t Address, const void *Decoder) {
5797   DecodeStatus S = MCDisassembler::Success;
5798 
5799   unsigned Rn = fieldFromInstruction(Val, 16, 4);
5800   unsigned Rt = fieldFromInstruction(Val, 12, 4);
5801   unsigned Rm = fieldFromInstruction(Val, 0, 4);
5802   Rm |= (fieldFromInstruction(Val, 23, 1) << 4);
5803   unsigned Cond = fieldFromInstruction(Val, 28, 4);
5804 
5805   if (fieldFromInstruction(Val, 8, 4) != 0 || Rn == Rt)
5806     S = MCDisassembler::SoftFail;
5807 
5808   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5809     return MCDisassembler::Fail;
5810   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
5811     return MCDisassembler::Fail;
5812   if (!Check(S, DecodeAddrMode7Operand(Inst, Rn, Address, Decoder)))
5813     return MCDisassembler::Fail;
5814   if (!Check(S, DecodePostIdxReg(Inst, Rm, Address, Decoder)))
5815     return MCDisassembler::Fail;
5816   if (!Check(S, DecodePredicateOperand(Inst, Cond, Address, Decoder)))
5817     return MCDisassembler::Fail;
5818 
5819   return S;
5820 }
5821 
5822 static DecodeStatus DecoderForMRRC2AndMCRR2(MCInst &Inst, unsigned Val,
5823                                             uint64_t Address, const void *Decoder) {
5824   DecodeStatus S = MCDisassembler::Success;
5825 
5826   unsigned CRm = fieldFromInstruction(Val, 0, 4);
5827   unsigned opc1 = fieldFromInstruction(Val, 4, 4);
5828   unsigned cop = fieldFromInstruction(Val, 8, 4);
5829   unsigned Rt = fieldFromInstruction(Val, 12, 4);
5830   unsigned Rt2 = fieldFromInstruction(Val, 16, 4);
5831 
5832   if ((cop & ~0x1) == 0xa)
5833     return MCDisassembler::Fail;
5834 
5835   if (Rt == Rt2)
5836     S = MCDisassembler::SoftFail;
5837 
5838   // We have to check if the instruction is MRRC2
5839   // or MCRR2 when constructing the operands for
5840   // Inst. Reason is because MRRC2 stores to two
5841   // registers so it's tablegen desc has has two
5842   // outputs whereas MCRR doesn't store to any
5843   // registers so all of it's operands are listed
5844   // as inputs, therefore the operand order for
5845   // MRRC2 needs to be [Rt, Rt2, cop, opc1, CRm]
5846   // and MCRR2 operand order is [cop, opc1, Rt, Rt2, CRm]
5847 
5848   if (Inst.getOpcode() == ARM::MRRC2) {
5849     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5850       return MCDisassembler::Fail;
5851     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5852       return MCDisassembler::Fail;
5853   }
5854   Inst.addOperand(MCOperand::createImm(cop));
5855   Inst.addOperand(MCOperand::createImm(opc1));
5856   if (Inst.getOpcode() == ARM::MCRR2) {
5857     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5858       return MCDisassembler::Fail;
5859     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5860       return MCDisassembler::Fail;
5861   }
5862   Inst.addOperand(MCOperand::createImm(CRm));
5863 
5864   return S;
5865 }
5866 
5867 static DecodeStatus DecodeForVMRSandVMSR(MCInst &Inst, unsigned Val,
5868                                          uint64_t Address,
5869                                          const void *Decoder) {
5870   const FeatureBitset &featureBits =
5871       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5872   DecodeStatus S = MCDisassembler::Success;
5873 
5874   // Add explicit operand for the destination sysreg, for cases where
5875   // we have to model it for code generation purposes.
5876   switch (Inst.getOpcode()) {
5877   case ARM::VMSR_FPSCR_NZCVQC:
5878     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
5879     break;
5880   case ARM::VMSR_P0:
5881     Inst.addOperand(MCOperand::createReg(ARM::VPR));
5882     break;
5883   }
5884 
5885   if (Inst.getOpcode() != ARM::FMSTAT) {
5886     unsigned Rt = fieldFromInstruction(Val, 12, 4);
5887 
5888     if (featureBits[ARM::ModeThumb] && !featureBits[ARM::HasV8Ops]) {
5889       if (Rt == 13 || Rt == 15)
5890         S = MCDisassembler::SoftFail;
5891       Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder));
5892     } else
5893       Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder));
5894   }
5895 
5896   // Add explicit operand for the source sysreg, similarly to above.
5897   switch (Inst.getOpcode()) {
5898   case ARM::VMRS_FPSCR_NZCVQC:
5899     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
5900     break;
5901   case ARM::VMRS_P0:
5902     Inst.addOperand(MCOperand::createReg(ARM::VPR));
5903     break;
5904   }
5905 
5906   if (featureBits[ARM::ModeThumb]) {
5907     Inst.addOperand(MCOperand::createImm(ARMCC::AL));
5908     Inst.addOperand(MCOperand::createReg(0));
5909   } else {
5910     unsigned pred = fieldFromInstruction(Val, 28, 4);
5911     if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5912       return MCDisassembler::Fail;
5913   }
5914 
5915   return S;
5916 }
5917 
5918 template <bool isSigned, bool isNeg, int size>
5919 static DecodeStatus DecodeBFLabelOperand(MCInst &Inst, unsigned Val,
5920                                          uint64_t Address,
5921                                          const void *Decoder) {
5922   DecodeStatus S = MCDisassembler::Success;
5923   if (Val == 0)
5924     S = MCDisassembler::SoftFail;
5925 
5926   uint64_t DecVal;
5927   if (isSigned)
5928     DecVal = SignExtend32<size + 1>(Val << 1);
5929   else
5930     DecVal = (Val << 1);
5931 
5932   if (!tryAddingSymbolicOperand(Address, Address + DecVal + 4, true, 4, Inst,
5933                                 Decoder))
5934     Inst.addOperand(MCOperand::createImm(isNeg ? -DecVal : DecVal));
5935   return S;
5936 }
5937 
5938 static DecodeStatus DecodeBFAfterTargetOperand(MCInst &Inst, unsigned Val,
5939                                                uint64_t Address,
5940                                                const void *Decoder) {
5941 
5942   uint64_t LocImm = Inst.getOperand(0).getImm();
5943   Val = LocImm + (2 << Val);
5944   if (!tryAddingSymbolicOperand(Address, Address + Val + 4, true, 4, Inst,
5945                                 Decoder))
5946     Inst.addOperand(MCOperand::createImm(Val));
5947   return MCDisassembler::Success;
5948 }
5949 
5950 static DecodeStatus DecodePredNoALOperand(MCInst &Inst, unsigned Val,
5951                                           uint64_t Address,
5952                                           const void *Decoder) {
5953   if (Val >= ARMCC::AL)  // also exclude the non-condition NV
5954     return MCDisassembler::Fail;
5955   Inst.addOperand(MCOperand::createImm(Val));
5956   return MCDisassembler::Success;
5957 }
5958 
5959 static DecodeStatus DecodeLOLoop(MCInst &Inst, unsigned Insn, uint64_t Address,
5960                                  const void *Decoder) {
5961   DecodeStatus S = MCDisassembler::Success;
5962 
5963   if (Inst.getOpcode() == ARM::MVE_LCTP)
5964     return S;
5965 
5966   unsigned Imm = fieldFromInstruction(Insn, 11, 1) |
5967                  fieldFromInstruction(Insn, 1, 10) << 1;
5968   switch (Inst.getOpcode()) {
5969   case ARM::t2LEUpdate:
5970   case ARM::MVE_LETP:
5971     Inst.addOperand(MCOperand::createReg(ARM::LR));
5972     Inst.addOperand(MCOperand::createReg(ARM::LR));
5973     LLVM_FALLTHROUGH;
5974   case ARM::t2LE:
5975     if (!Check(S, DecodeBFLabelOperand<false, true, 11>(Inst, Imm, Address,
5976                                                         Decoder)))
5977       return MCDisassembler::Fail;
5978     break;
5979   case ARM::t2WLS:
5980   case ARM::MVE_WLSTP_8:
5981   case ARM::MVE_WLSTP_16:
5982   case ARM::MVE_WLSTP_32:
5983   case ARM::MVE_WLSTP_64:
5984     Inst.addOperand(MCOperand::createReg(ARM::LR));
5985     if (!Check(S,
5986                DecoderGPRRegisterClass(Inst, fieldFromInstruction(Insn, 16, 4),
5987                                        Address, Decoder)) ||
5988         !Check(S, DecodeBFLabelOperand<false, false, 11>(Inst, Imm, Address,
5989                                                          Decoder)))
5990       return MCDisassembler::Fail;
5991     break;
5992   case ARM::t2DLS:
5993   case ARM::MVE_DLSTP_8:
5994   case ARM::MVE_DLSTP_16:
5995   case ARM::MVE_DLSTP_32:
5996   case ARM::MVE_DLSTP_64:
5997     unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5998     if (Rn == 0xF) {
5999       // Enforce all the rest of the instruction bits in LCTP, which
6000       // won't have been reliably checked based on LCTP's own tablegen
6001       // record, because we came to this decode by a roundabout route.
6002       uint32_t CanonicalLCTP = 0xF00FE001, SBZMask = 0x00300FFE;
6003       if ((Insn & ~SBZMask) != CanonicalLCTP)
6004         return MCDisassembler::Fail;   // a mandatory bit is wrong: hard fail
6005       if (Insn != CanonicalLCTP)
6006         Check(S, MCDisassembler::SoftFail); // an SBZ bit is wrong: soft fail
6007 
6008       Inst.setOpcode(ARM::MVE_LCTP);
6009     } else {
6010       Inst.addOperand(MCOperand::createReg(ARM::LR));
6011       if (!Check(S, DecoderGPRRegisterClass(Inst,
6012                                             fieldFromInstruction(Insn, 16, 4),
6013                                             Address, Decoder)))
6014         return MCDisassembler::Fail;
6015     }
6016     break;
6017   }
6018   return S;
6019 }
6020 
6021 static DecodeStatus DecodeLongShiftOperand(MCInst &Inst, unsigned Val,
6022                                            uint64_t Address,
6023                                            const void *Decoder) {
6024   DecodeStatus S = MCDisassembler::Success;
6025 
6026   if (Val == 0)
6027     Val = 32;
6028 
6029   Inst.addOperand(MCOperand::createImm(Val));
6030 
6031   return S;
6032 }
6033 
6034 static DecodeStatus DecodetGPROddRegisterClass(MCInst &Inst, unsigned RegNo,
6035                                    uint64_t Address, const void *Decoder) {
6036   if ((RegNo) + 1 > 11)
6037     return MCDisassembler::Fail;
6038 
6039   unsigned Register = GPRDecoderTable[(RegNo) + 1];
6040   Inst.addOperand(MCOperand::createReg(Register));
6041   return MCDisassembler::Success;
6042 }
6043 
6044 static DecodeStatus DecodetGPREvenRegisterClass(MCInst &Inst, unsigned RegNo,
6045                                    uint64_t Address, const void *Decoder) {
6046   if ((RegNo) > 14)
6047     return MCDisassembler::Fail;
6048 
6049   unsigned Register = GPRDecoderTable[(RegNo)];
6050   Inst.addOperand(MCOperand::createReg(Register));
6051   return MCDisassembler::Success;
6052 }
6053 
6054 static DecodeStatus DecodeVSCCLRM(MCInst &Inst, unsigned Insn, uint64_t Address,
6055                                   const void *Decoder) {
6056   DecodeStatus S = MCDisassembler::Success;
6057 
6058   Inst.addOperand(MCOperand::createImm(ARMCC::AL));
6059   Inst.addOperand(MCOperand::createReg(0));
6060   if (Inst.getOpcode() == ARM::VSCCLRMD) {
6061     unsigned reglist = (fieldFromInstruction(Insn, 1, 7) << 1) |
6062                        (fieldFromInstruction(Insn, 12, 4) << 8) |
6063                        (fieldFromInstruction(Insn, 22, 1) << 12);
6064     if (!Check(S, DecodeDPRRegListOperand(Inst, reglist, Address, Decoder))) {
6065       return MCDisassembler::Fail;
6066     }
6067   } else {
6068     unsigned reglist = fieldFromInstruction(Insn, 0, 8) |
6069                        (fieldFromInstruction(Insn, 22, 1) << 8) |
6070                        (fieldFromInstruction(Insn, 12, 4) << 9);
6071     if (!Check(S, DecodeSPRRegListOperand(Inst, reglist, Address, Decoder))) {
6072       return MCDisassembler::Fail;
6073     }
6074   }
6075   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6076 
6077   return S;
6078 }
6079 
6080 static DecodeStatus DecodeMQPRRegisterClass(MCInst &Inst, unsigned RegNo,
6081                               uint64_t Address,
6082                               const void *Decoder) {
6083   if (RegNo > 7)
6084     return MCDisassembler::Fail;
6085 
6086   unsigned Register = QPRDecoderTable[RegNo];
6087   Inst.addOperand(MCOperand::createReg(Register));
6088   return MCDisassembler::Success;
6089 }
6090 
6091 static const uint16_t QQPRDecoderTable[] = {
6092      ARM::Q0_Q1,  ARM::Q1_Q2,  ARM::Q2_Q3,  ARM::Q3_Q4,
6093      ARM::Q4_Q5,  ARM::Q5_Q6,  ARM::Q6_Q7
6094 };
6095 
6096 static DecodeStatus DecodeQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
6097                               uint64_t Address,
6098                               const void *Decoder) {
6099   if (RegNo > 6)
6100     return MCDisassembler::Fail;
6101 
6102   unsigned Register = QQPRDecoderTable[RegNo];
6103   Inst.addOperand(MCOperand::createReg(Register));
6104   return MCDisassembler::Success;
6105 }
6106 
6107 static const uint16_t QQQQPRDecoderTable[] = {
6108      ARM::Q0_Q1_Q2_Q3,  ARM::Q1_Q2_Q3_Q4,  ARM::Q2_Q3_Q4_Q5,
6109      ARM::Q3_Q4_Q5_Q6,  ARM::Q4_Q5_Q6_Q7
6110 };
6111 
6112 static DecodeStatus DecodeQQQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
6113                               uint64_t Address,
6114                               const void *Decoder) {
6115   if (RegNo > 4)
6116     return MCDisassembler::Fail;
6117 
6118   unsigned Register = QQQQPRDecoderTable[RegNo];
6119   Inst.addOperand(MCOperand::createReg(Register));
6120   return MCDisassembler::Success;
6121 }
6122 
6123 static DecodeStatus DecodeVPTMaskOperand(MCInst &Inst, unsigned Val,
6124                                          uint64_t Address,
6125                                          const void *Decoder) {
6126   DecodeStatus S = MCDisassembler::Success;
6127 
6128   // Parse VPT mask and encode it in the MCInst as an immediate with the same
6129   // format as the it_mask.  That is, from the second 'e|t' encode 'e' as 1 and
6130   // 't' as 0 and finish with a 1.
6131   unsigned Imm = 0;
6132   // We always start with a 't'.
6133   unsigned CurBit = 0;
6134   for (int i = 3; i >= 0; --i) {
6135     // If the bit we are looking at is not the same as last one, invert the
6136     // CurBit, if it is the same leave it as is.
6137     CurBit ^= (Val >> i) & 1U;
6138 
6139     // Encode the CurBit at the right place in the immediate.
6140     Imm |= (CurBit << i);
6141 
6142     // If we are done, finish the encoding with a 1.
6143     if ((Val & ~(~0U << i)) == 0) {
6144       Imm |= 1U << i;
6145       break;
6146     }
6147   }
6148 
6149   Inst.addOperand(MCOperand::createImm(Imm));
6150 
6151   return S;
6152 }
6153 
6154 static DecodeStatus DecodeVpredROperand(MCInst &Inst, unsigned RegNo,
6155                                         uint64_t Address, const void *Decoder) {
6156   // The vpred_r operand type includes an MQPR register field derived
6157   // from the encoding. But we don't actually want to add an operand
6158   // to the MCInst at this stage, because AddThumbPredicate will do it
6159   // later, and will infer the register number from the TIED_TO
6160   // constraint. So this is a deliberately empty decoder method that
6161   // will inhibit the auto-generated disassembly code from adding an
6162   // operand at all.
6163   return MCDisassembler::Success;
6164 }
6165 
6166 static DecodeStatus DecodeRestrictedIPredicateOperand(MCInst &Inst,
6167                                                       unsigned Val,
6168                                                       uint64_t Address,
6169                                                       const void *Decoder) {
6170   Inst.addOperand(MCOperand::createImm((Val & 0x1) == 0 ? ARMCC::EQ : ARMCC::NE));
6171   return MCDisassembler::Success;
6172 }
6173 
6174 static DecodeStatus DecodeRestrictedSPredicateOperand(MCInst &Inst,
6175                                                       unsigned Val,
6176                                                       uint64_t Address,
6177                                                       const void *Decoder) {
6178   unsigned Code;
6179   switch (Val & 0x3) {
6180   case 0:
6181     Code = ARMCC::GE;
6182     break;
6183   case 1:
6184     Code = ARMCC::LT;
6185     break;
6186   case 2:
6187     Code = ARMCC::GT;
6188     break;
6189   case 3:
6190     Code = ARMCC::LE;
6191     break;
6192   }
6193   Inst.addOperand(MCOperand::createImm(Code));
6194   return MCDisassembler::Success;
6195 }
6196 
6197 static DecodeStatus DecodeRestrictedUPredicateOperand(MCInst &Inst,
6198                                                       unsigned Val,
6199                                                       uint64_t Address,
6200                                                       const void *Decoder) {
6201   Inst.addOperand(MCOperand::createImm((Val & 0x1) == 0 ? ARMCC::HS : ARMCC::HI));
6202   return MCDisassembler::Success;
6203 }
6204 
6205 static DecodeStatus DecodeRestrictedFPPredicateOperand(MCInst &Inst, unsigned Val,
6206                                                      uint64_t Address,
6207                                                      const void *Decoder) {
6208   unsigned Code;
6209   switch (Val) {
6210   default:
6211     return MCDisassembler::Fail;
6212   case 0:
6213     Code = ARMCC::EQ;
6214     break;
6215   case 1:
6216     Code = ARMCC::NE;
6217     break;
6218   case 4:
6219     Code = ARMCC::GE;
6220     break;
6221   case 5:
6222     Code = ARMCC::LT;
6223     break;
6224   case 6:
6225     Code = ARMCC::GT;
6226     break;
6227   case 7:
6228     Code = ARMCC::LE;
6229     break;
6230   }
6231 
6232   Inst.addOperand(MCOperand::createImm(Code));
6233   return MCDisassembler::Success;
6234 }
6235 
6236 static DecodeStatus DecodeVCVTImmOperand(MCInst &Inst, unsigned Val,
6237                                          uint64_t Address, const void *Decoder) {
6238   DecodeStatus S = MCDisassembler::Success;
6239 
6240   unsigned DecodedVal = 64 - Val;
6241 
6242   switch (Inst.getOpcode()) {
6243   case ARM::MVE_VCVTf16s16_fix:
6244   case ARM::MVE_VCVTs16f16_fix:
6245   case ARM::MVE_VCVTf16u16_fix:
6246   case ARM::MVE_VCVTu16f16_fix:
6247     if (DecodedVal > 16)
6248       return MCDisassembler::Fail;
6249     break;
6250   case ARM::MVE_VCVTf32s32_fix:
6251   case ARM::MVE_VCVTs32f32_fix:
6252   case ARM::MVE_VCVTf32u32_fix:
6253   case ARM::MVE_VCVTu32f32_fix:
6254     if (DecodedVal > 32)
6255       return MCDisassembler::Fail;
6256     break;
6257   }
6258 
6259   Inst.addOperand(MCOperand::createImm(64 - Val));
6260 
6261   return S;
6262 }
6263 
6264 static unsigned FixedRegForVSTRVLDR_SYSREG(unsigned Opcode) {
6265   switch (Opcode) {
6266   case ARM::VSTR_P0_off:
6267   case ARM::VSTR_P0_pre:
6268   case ARM::VSTR_P0_post:
6269   case ARM::VLDR_P0_off:
6270   case ARM::VLDR_P0_pre:
6271   case ARM::VLDR_P0_post:
6272     return ARM::P0;
6273   default:
6274     return 0;
6275   }
6276 }
6277 
6278 template<bool Writeback>
6279 static DecodeStatus DecodeVSTRVLDR_SYSREG(MCInst &Inst, unsigned Val,
6280                                           uint64_t Address,
6281                                           const void *Decoder) {
6282   switch (Inst.getOpcode()) {
6283   case ARM::VSTR_FPSCR_pre:
6284   case ARM::VSTR_FPSCR_NZCVQC_pre:
6285   case ARM::VLDR_FPSCR_pre:
6286   case ARM::VLDR_FPSCR_NZCVQC_pre:
6287   case ARM::VSTR_FPSCR_off:
6288   case ARM::VSTR_FPSCR_NZCVQC_off:
6289   case ARM::VLDR_FPSCR_off:
6290   case ARM::VLDR_FPSCR_NZCVQC_off:
6291   case ARM::VSTR_FPSCR_post:
6292   case ARM::VSTR_FPSCR_NZCVQC_post:
6293   case ARM::VLDR_FPSCR_post:
6294   case ARM::VLDR_FPSCR_NZCVQC_post:
6295     const FeatureBitset &featureBits =
6296         ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
6297 
6298     if (!featureBits[ARM::HasMVEIntegerOps] && !featureBits[ARM::FeatureVFP2])
6299       return MCDisassembler::Fail;
6300   }
6301 
6302   DecodeStatus S = MCDisassembler::Success;
6303   if (unsigned Sysreg = FixedRegForVSTRVLDR_SYSREG(Inst.getOpcode()))
6304     Inst.addOperand(MCOperand::createReg(Sysreg));
6305   unsigned Rn = fieldFromInstruction(Val, 16, 4);
6306   unsigned addr = fieldFromInstruction(Val, 0, 7) |
6307                   (fieldFromInstruction(Val, 23, 1) << 7) | (Rn << 8);
6308 
6309   if (Writeback) {
6310     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
6311       return MCDisassembler::Fail;
6312   }
6313   if (!Check(S, DecodeT2AddrModeImm7s4(Inst, addr, Address, Decoder)))
6314     return MCDisassembler::Fail;
6315 
6316   Inst.addOperand(MCOperand::createImm(ARMCC::AL));
6317   Inst.addOperand(MCOperand::createReg(0));
6318 
6319   return S;
6320 }
6321 
6322 static inline DecodeStatus DecodeMVE_MEM_pre(
6323   MCInst &Inst, unsigned Val, uint64_t Address, const void *Decoder,
6324   unsigned Rn, OperandDecoder RnDecoder, OperandDecoder AddrDecoder) {
6325   DecodeStatus S = MCDisassembler::Success;
6326 
6327   unsigned Qd = fieldFromInstruction(Val, 13, 3);
6328   unsigned addr = fieldFromInstruction(Val, 0, 7) |
6329                   (fieldFromInstruction(Val, 23, 1) << 7) | (Rn << 8);
6330 
6331   if (!Check(S, RnDecoder(Inst, Rn, Address, Decoder)))
6332     return MCDisassembler::Fail;
6333   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6334     return MCDisassembler::Fail;
6335   if (!Check(S, AddrDecoder(Inst, addr, Address, Decoder)))
6336     return MCDisassembler::Fail;
6337 
6338   return S;
6339 }
6340 
6341 template <int shift>
6342 static DecodeStatus DecodeMVE_MEM_1_pre(MCInst &Inst, unsigned Val,
6343                                         uint64_t Address, const void *Decoder) {
6344   return DecodeMVE_MEM_pre(Inst, Val, Address, Decoder,
6345                            fieldFromInstruction(Val, 16, 3),
6346                            DecodetGPRRegisterClass,
6347                            DecodeTAddrModeImm7<shift>);
6348 }
6349 
6350 template <int shift>
6351 static DecodeStatus DecodeMVE_MEM_2_pre(MCInst &Inst, unsigned Val,
6352                                         uint64_t Address, const void *Decoder) {
6353   return DecodeMVE_MEM_pre(Inst, Val, Address, Decoder,
6354                            fieldFromInstruction(Val, 16, 4),
6355                            DecoderGPRRegisterClass,
6356                            DecodeT2AddrModeImm7<shift,1>);
6357 }
6358 
6359 template <int shift>
6360 static DecodeStatus DecodeMVE_MEM_3_pre(MCInst &Inst, unsigned Val,
6361                                         uint64_t Address, const void *Decoder) {
6362   return DecodeMVE_MEM_pre(Inst, Val, Address, Decoder,
6363                            fieldFromInstruction(Val, 17, 3),
6364                            DecodeMQPRRegisterClass,
6365                            DecodeMveAddrModeQ<shift>);
6366 }
6367 
6368 template<unsigned MinLog, unsigned MaxLog>
6369 static DecodeStatus DecodePowerTwoOperand(MCInst &Inst, unsigned Val,
6370                                           uint64_t Address,
6371                                           const void *Decoder) {
6372   DecodeStatus S = MCDisassembler::Success;
6373 
6374   if (Val < MinLog || Val > MaxLog)
6375     return MCDisassembler::Fail;
6376 
6377   Inst.addOperand(MCOperand::createImm(1LL << Val));
6378   return S;
6379 }
6380 
6381 template <int shift>
6382 static DecodeStatus DecodeExpandedImmOperand(MCInst &Inst, unsigned Val,
6383                                              uint64_t Address,
6384                                              const void *Decoder) {
6385     Val <<= shift;
6386 
6387     Inst.addOperand(MCOperand::createImm(Val));
6388     return MCDisassembler::Success;
6389 }
6390 
6391 template<unsigned start>
6392 static DecodeStatus DecodeMVEPairVectorIndexOperand(MCInst &Inst, unsigned Val,
6393                                                     uint64_t Address,
6394                                                     const void *Decoder) {
6395   DecodeStatus S = MCDisassembler::Success;
6396 
6397   Inst.addOperand(MCOperand::createImm(start + Val));
6398 
6399   return S;
6400 }
6401 
6402 static DecodeStatus DecodeMVEVMOVQtoDReg(MCInst &Inst, unsigned Insn,
6403                                          uint64_t Address, const void *Decoder) {
6404   DecodeStatus S = MCDisassembler::Success;
6405   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
6406   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
6407   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
6408                  fieldFromInstruction(Insn, 13, 3));
6409   unsigned index = fieldFromInstruction(Insn, 4, 1);
6410 
6411   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
6412     return MCDisassembler::Fail;
6413   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2, Address, Decoder)))
6414     return MCDisassembler::Fail;
6415   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6416     return MCDisassembler::Fail;
6417   if (!Check(S, DecodeMVEPairVectorIndexOperand<2>(Inst, index, Address, Decoder)))
6418     return MCDisassembler::Fail;
6419   if (!Check(S, DecodeMVEPairVectorIndexOperand<0>(Inst, index, Address, Decoder)))
6420     return MCDisassembler::Fail;
6421 
6422   return S;
6423 }
6424 
6425 static DecodeStatus DecodeMVEVMOVDRegtoQ(MCInst &Inst, unsigned Insn,
6426                                          uint64_t Address, const void *Decoder) {
6427   DecodeStatus S = MCDisassembler::Success;
6428   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
6429   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
6430   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
6431                  fieldFromInstruction(Insn, 13, 3));
6432   unsigned index = fieldFromInstruction(Insn, 4, 1);
6433 
6434   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6435     return MCDisassembler::Fail;
6436   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6437     return MCDisassembler::Fail;
6438   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
6439     return MCDisassembler::Fail;
6440   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2, Address, Decoder)))
6441     return MCDisassembler::Fail;
6442   if (!Check(S, DecodeMVEPairVectorIndexOperand<2>(Inst, index, Address, Decoder)))
6443     return MCDisassembler::Fail;
6444   if (!Check(S, DecodeMVEPairVectorIndexOperand<0>(Inst, index, Address, Decoder)))
6445     return MCDisassembler::Fail;
6446 
6447   return S;
6448 }
6449 
6450 static DecodeStatus DecodeMVEOverlappingLongShift(
6451   MCInst &Inst, unsigned Insn, uint64_t Address, const void *Decoder) {
6452   DecodeStatus S = MCDisassembler::Success;
6453 
6454   unsigned RdaLo = fieldFromInstruction(Insn, 17, 3) << 1;
6455   unsigned RdaHi = fieldFromInstruction(Insn, 9, 3) << 1;
6456   unsigned Rm = fieldFromInstruction(Insn, 12, 4);
6457 
6458   if (RdaHi == 14) {
6459     // This value of RdaHi (really indicating pc, because RdaHi has to
6460     // be an odd-numbered register, so the low bit will be set by the
6461     // decode function below) indicates that we must decode as SQRSHR
6462     // or UQRSHL, which both have a single Rda register field with all
6463     // four bits.
6464     unsigned Rda = fieldFromInstruction(Insn, 16, 4);
6465 
6466     switch (Inst.getOpcode()) {
6467       case ARM::MVE_ASRLr:
6468       case ARM::MVE_SQRSHRL:
6469         Inst.setOpcode(ARM::MVE_SQRSHR);
6470         break;
6471       case ARM::MVE_LSLLr:
6472       case ARM::MVE_UQRSHLL:
6473         Inst.setOpcode(ARM::MVE_UQRSHL);
6474         break;
6475       default:
6476         llvm_unreachable("Unexpected starting opcode!");
6477     }
6478 
6479     // Rda as output parameter
6480     if (!Check(S, DecoderGPRRegisterClass(Inst, Rda, Address, Decoder)))
6481       return MCDisassembler::Fail;
6482 
6483     // Rda again as input parameter
6484     if (!Check(S, DecoderGPRRegisterClass(Inst, Rda, Address, Decoder)))
6485       return MCDisassembler::Fail;
6486 
6487     // Rm, the amount to shift by
6488     if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
6489       return MCDisassembler::Fail;
6490 
6491     return S;
6492   }
6493 
6494   // Otherwise, we decode as whichever opcode our caller has already
6495   // put into Inst. Those all look the same:
6496 
6497   // RdaLo,RdaHi as output parameters
6498   if (!Check(S, DecodetGPREvenRegisterClass(Inst, RdaLo, Address, Decoder)))
6499     return MCDisassembler::Fail;
6500   if (!Check(S, DecodetGPROddRegisterClass(Inst, RdaHi, Address, Decoder)))
6501     return MCDisassembler::Fail;
6502 
6503   // RdaLo,RdaHi again as input parameters
6504   if (!Check(S, DecodetGPREvenRegisterClass(Inst, RdaLo, Address, Decoder)))
6505     return MCDisassembler::Fail;
6506   if (!Check(S, DecodetGPROddRegisterClass(Inst, RdaHi, Address, Decoder)))
6507     return MCDisassembler::Fail;
6508 
6509   // Rm, the amount to shift by
6510   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
6511     return MCDisassembler::Fail;
6512 
6513   return S;
6514 }
6515 
6516 static DecodeStatus DecodeMVEVCVTt1fp(MCInst &Inst, unsigned Insn, uint64_t Address,
6517                                       const void *Decoder) {
6518   DecodeStatus S = MCDisassembler::Success;
6519   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
6520                  fieldFromInstruction(Insn, 13, 3));
6521   unsigned Qm = ((fieldFromInstruction(Insn, 5, 1) << 3) |
6522                  fieldFromInstruction(Insn, 1, 3));
6523   unsigned imm6 = fieldFromInstruction(Insn, 16, 6);
6524 
6525   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6526     return MCDisassembler::Fail;
6527   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
6528     return MCDisassembler::Fail;
6529   if (!Check(S, DecodeVCVTImmOperand(Inst, imm6, Address, Decoder)))
6530     return MCDisassembler::Fail;
6531 
6532   return S;
6533 }
6534 
6535 template<bool scalar, OperandDecoder predicate_decoder>
6536 static DecodeStatus DecodeMVEVCMP(MCInst &Inst, unsigned Insn, uint64_t Address,
6537                                   const void *Decoder) {
6538   DecodeStatus S = MCDisassembler::Success;
6539   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6540   unsigned Qn = fieldFromInstruction(Insn, 17, 3);
6541   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qn, Address, Decoder)))
6542     return MCDisassembler::Fail;
6543 
6544   unsigned fc;
6545 
6546   if (scalar) {
6547     fc = fieldFromInstruction(Insn, 12, 1) << 2 |
6548          fieldFromInstruction(Insn, 7, 1) |
6549          fieldFromInstruction(Insn, 5, 1) << 1;
6550     unsigned Rm = fieldFromInstruction(Insn, 0, 4);
6551     if (!Check(S, DecodeGPRwithZRRegisterClass(Inst, Rm, Address, Decoder)))
6552       return MCDisassembler::Fail;
6553   } else {
6554     fc = fieldFromInstruction(Insn, 12, 1) << 2 |
6555          fieldFromInstruction(Insn, 7, 1) |
6556          fieldFromInstruction(Insn, 0, 1) << 1;
6557     unsigned Qm = fieldFromInstruction(Insn, 5, 1) << 4 |
6558                   fieldFromInstruction(Insn, 1, 3);
6559     if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
6560       return MCDisassembler::Fail;
6561   }
6562 
6563   if (!Check(S, predicate_decoder(Inst, fc, Address, Decoder)))
6564     return MCDisassembler::Fail;
6565 
6566   Inst.addOperand(MCOperand::createImm(ARMVCC::None));
6567   Inst.addOperand(MCOperand::createReg(0));
6568   Inst.addOperand(MCOperand::createImm(0));
6569 
6570   return S;
6571 }
6572 
6573 static DecodeStatus DecodeMveVCTP(MCInst &Inst, unsigned Insn, uint64_t Address,
6574                                   const void *Decoder) {
6575   DecodeStatus S = MCDisassembler::Success;
6576   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6577   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
6578   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
6579     return MCDisassembler::Fail;
6580   return S;
6581 }
6582