xref: /llvm-project/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp (revision 86b7a1e660b55d0082a671282523fa30cc9bff6a)
1 //===- ARMDisassembler.cpp - Disassembler for ARM/Thumb ISA ---------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "ARMBaseInstrInfo.h"
10 #include "MCTargetDesc/ARMAddressingModes.h"
11 #include "MCTargetDesc/ARMBaseInfo.h"
12 #include "MCTargetDesc/ARMMCTargetDesc.h"
13 #include "TargetInfo/ARMTargetInfo.h"
14 #include "Utils/ARMBaseInfo.h"
15 #include "llvm/MC/MCContext.h"
16 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
17 #include "llvm/MC/MCFixedLenDisassembler.h"
18 #include "llvm/MC/MCInst.h"
19 #include "llvm/MC/MCInstrDesc.h"
20 #include "llvm/MC/MCSubtargetInfo.h"
21 #include "llvm/MC/SubtargetFeature.h"
22 #include "llvm/Support/Compiler.h"
23 #include "llvm/Support/ErrorHandling.h"
24 #include "llvm/Support/MathExtras.h"
25 #include "llvm/Support/TargetRegistry.h"
26 #include "llvm/Support/raw_ostream.h"
27 #include <algorithm>
28 #include <cassert>
29 #include <cstdint>
30 #include <vector>
31 
32 using namespace llvm;
33 
34 #define DEBUG_TYPE "arm-disassembler"
35 
36 using DecodeStatus = MCDisassembler::DecodeStatus;
37 
38 namespace {
39 
40   // Handles the condition code status of instructions in IT blocks
41   class ITStatus
42   {
43     public:
44       // Returns the condition code for instruction in IT block
45       unsigned getITCC() {
46         unsigned CC = ARMCC::AL;
47         if (instrInITBlock())
48           CC = ITStates.back();
49         return CC;
50       }
51 
52       // Advances the IT block state to the next T or E
53       void advanceITState() {
54         ITStates.pop_back();
55       }
56 
57       // Returns true if the current instruction is in an IT block
58       bool instrInITBlock() {
59         return !ITStates.empty();
60       }
61 
62       // Returns true if current instruction is the last instruction in an IT block
63       bool instrLastInITBlock() {
64         return ITStates.size() == 1;
65       }
66 
67       // Called when decoding an IT instruction. Sets the IT state for
68       // the following instructions that for the IT block. Firstcond
69       // corresponds to the field in the IT instruction encoding; Mask
70       // is in the MCOperand format in which 1 means 'else' and 0 'then'.
71       void setITState(char Firstcond, char Mask) {
72         // (3 - the number of trailing zeros) is the number of then / else.
73         unsigned NumTZ = countTrailingZeros<uint8_t>(Mask);
74         unsigned char CCBits = static_cast<unsigned char>(Firstcond & 0xf);
75         assert(NumTZ <= 3 && "Invalid IT mask!");
76         // push condition codes onto the stack the correct order for the pops
77         for (unsigned Pos = NumTZ+1; Pos <= 3; ++Pos) {
78           unsigned Else = (Mask >> Pos) & 1;
79           ITStates.push_back(CCBits ^ Else);
80         }
81         ITStates.push_back(CCBits);
82       }
83 
84     private:
85       std::vector<unsigned char> ITStates;
86   };
87 
88   class VPTStatus
89   {
90     public:
91       unsigned getVPTPred() {
92         unsigned Pred = ARMVCC::None;
93         if (instrInVPTBlock())
94           Pred = VPTStates.back();
95         return Pred;
96       }
97 
98       void advanceVPTState() {
99         VPTStates.pop_back();
100       }
101 
102       bool instrInVPTBlock() {
103         return !VPTStates.empty();
104       }
105 
106       bool instrLastInVPTBlock() {
107         return VPTStates.size() == 1;
108       }
109 
110       void setVPTState(char Mask) {
111         // (3 - the number of trailing zeros) is the number of then / else.
112         unsigned NumTZ = countTrailingZeros<uint8_t>(Mask);
113         assert(NumTZ <= 3 && "Invalid VPT mask!");
114         // push predicates onto the stack the correct order for the pops
115         for (unsigned Pos = NumTZ+1; Pos <= 3; ++Pos) {
116           bool T = ((Mask >> Pos) & 1) == 0;
117           if (T)
118             VPTStates.push_back(ARMVCC::Then);
119           else
120             VPTStates.push_back(ARMVCC::Else);
121         }
122         VPTStates.push_back(ARMVCC::Then);
123       }
124 
125     private:
126       SmallVector<unsigned char, 4> VPTStates;
127   };
128 
129 /// ARM disassembler for all ARM platforms.
130 class ARMDisassembler : public MCDisassembler {
131 public:
132   ARMDisassembler(const MCSubtargetInfo &STI, MCContext &Ctx) :
133     MCDisassembler(STI, Ctx) {
134   }
135 
136   ~ARMDisassembler() override = default;
137 
138   DecodeStatus getInstruction(MCInst &Instr, uint64_t &Size,
139                               ArrayRef<uint8_t> Bytes, uint64_t Address,
140                               raw_ostream &VStream,
141                               raw_ostream &CStream) const override;
142 
143 private:
144   DecodeStatus getARMInstruction(MCInst &Instr, uint64_t &Size,
145                                  ArrayRef<uint8_t> Bytes, uint64_t Address,
146                                  raw_ostream &VStream,
147                                  raw_ostream &CStream) const;
148 
149   DecodeStatus getThumbInstruction(MCInst &Instr, uint64_t &Size,
150                                    ArrayRef<uint8_t> Bytes, uint64_t Address,
151                                    raw_ostream &VStream,
152                                    raw_ostream &CStream) const;
153 
154   mutable ITStatus ITBlock;
155   mutable VPTStatus VPTBlock;
156 
157   DecodeStatus AddThumbPredicate(MCInst&) const;
158   void UpdateThumbVFPPredicate(DecodeStatus &, MCInst&) const;
159 };
160 
161 } // end anonymous namespace
162 
163 static bool Check(DecodeStatus &Out, DecodeStatus In) {
164   switch (In) {
165     case MCDisassembler::Success:
166       // Out stays the same.
167       return true;
168     case MCDisassembler::SoftFail:
169       Out = In;
170       return true;
171     case MCDisassembler::Fail:
172       Out = In;
173       return false;
174   }
175   llvm_unreachable("Invalid DecodeStatus!");
176 }
177 
178 // Forward declare these because the autogenerated code will reference them.
179 // Definitions are further down.
180 static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, unsigned RegNo,
181                                    uint64_t Address, const void *Decoder);
182 static DecodeStatus DecodeCLRMGPRRegisterClass(MCInst &Inst, unsigned RegNo,
183                                    uint64_t Address, const void *Decoder);
184 static DecodeStatus DecodetGPROddRegisterClass(MCInst &Inst, unsigned RegNo,
185                                    uint64_t Address, const void *Decoder);
186 static DecodeStatus DecodetGPREvenRegisterClass(MCInst &Inst, unsigned RegNo,
187                                    uint64_t Address, const void *Decoder);
188 static DecodeStatus DecodeGPRnopcRegisterClass(MCInst &Inst,
189                                                unsigned RegNo, uint64_t Address,
190                                                const void *Decoder);
191 static DecodeStatus DecodeGPRwithAPSRRegisterClass(MCInst &Inst,
192                                                unsigned RegNo, uint64_t Address,
193                                                const void *Decoder);
194 static DecodeStatus DecodeGPRwithZRRegisterClass(MCInst &Inst,
195                                                unsigned RegNo, uint64_t Address,
196                                                const void *Decoder);
197 static DecodeStatus DecodetGPRRegisterClass(MCInst &Inst, unsigned RegNo,
198                                    uint64_t Address, const void *Decoder);
199 static DecodeStatus DecodetcGPRRegisterClass(MCInst &Inst, unsigned RegNo,
200                                    uint64_t Address, const void *Decoder);
201 static DecodeStatus DecoderGPRRegisterClass(MCInst &Inst, unsigned RegNo,
202                                    uint64_t Address, const void *Decoder);
203 static DecodeStatus DecodeGPRPairRegisterClass(MCInst &Inst, unsigned RegNo,
204                                    uint64_t Address, const void *Decoder);
205 static DecodeStatus DecodeHPRRegisterClass(MCInst &Inst, unsigned RegNo,
206                                    uint64_t Address, const void *Decoder);
207 static DecodeStatus DecodeSPRRegisterClass(MCInst &Inst, unsigned RegNo,
208                                    uint64_t Address, const void *Decoder);
209 static DecodeStatus DecodeDPRRegisterClass(MCInst &Inst, unsigned RegNo,
210                                    uint64_t Address, const void *Decoder);
211 static DecodeStatus DecodeDPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
212                                    uint64_t Address, const void *Decoder);
213 static DecodeStatus DecodeSPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
214                                    uint64_t Address, const void *Decoder);
215 static DecodeStatus DecodeDPR_VFP2RegisterClass(MCInst &Inst,
216                                                 unsigned RegNo,
217                                                 uint64_t Address,
218                                                 const void *Decoder);
219 static DecodeStatus DecodeQPRRegisterClass(MCInst &Inst, unsigned RegNo,
220                                    uint64_t Address, const void *Decoder);
221 static DecodeStatus DecodeMQPRRegisterClass(MCInst &Inst, unsigned RegNo,
222                                    uint64_t Address, const void *Decoder);
223 static DecodeStatus DecodeQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
224                                    uint64_t Address, const void *Decoder);
225 static DecodeStatus DecodeQQQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
226                                    uint64_t Address, const void *Decoder);
227 static DecodeStatus DecodeDPairRegisterClass(MCInst &Inst, unsigned RegNo,
228                                    uint64_t Address, const void *Decoder);
229 static DecodeStatus DecodeDPairSpacedRegisterClass(MCInst &Inst,
230                                unsigned RegNo, uint64_t Address,
231                                const void *Decoder);
232 
233 static DecodeStatus DecodePredicateOperand(MCInst &Inst, unsigned Val,
234                                uint64_t Address, const void *Decoder);
235 static DecodeStatus DecodeCCOutOperand(MCInst &Inst, unsigned Val,
236                                uint64_t Address, const void *Decoder);
237 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Val,
238                                uint64_t Address, const void *Decoder);
239 static DecodeStatus DecodeSPRRegListOperand(MCInst &Inst, unsigned Val,
240                                uint64_t Address, const void *Decoder);
241 static DecodeStatus DecodeDPRRegListOperand(MCInst &Inst, unsigned Val,
242                                uint64_t Address, const void *Decoder);
243 
244 static DecodeStatus DecodeBitfieldMaskOperand(MCInst &Inst, unsigned Insn,
245                                uint64_t Address, const void *Decoder);
246 static DecodeStatus DecodeCopMemInstruction(MCInst &Inst, unsigned Insn,
247                                uint64_t Address, const void *Decoder);
248 static DecodeStatus DecodeAddrMode2IdxInstruction(MCInst &Inst,
249                                                   unsigned Insn,
250                                                   uint64_t Address,
251                                                   const void *Decoder);
252 static DecodeStatus DecodeSORegMemOperand(MCInst &Inst, unsigned Insn,
253                                uint64_t Address, const void *Decoder);
254 static DecodeStatus DecodeAddrMode3Instruction(MCInst &Inst,unsigned Insn,
255                                uint64_t Address, const void *Decoder);
256 static DecodeStatus DecodeSORegImmOperand(MCInst &Inst, unsigned Insn,
257                                uint64_t Address, const void *Decoder);
258 static DecodeStatus DecodeSORegRegOperand(MCInst &Inst, unsigned Insn,
259                                uint64_t Address, const void *Decoder);
260 
261 static DecodeStatus DecodeMemMultipleWritebackInstruction(MCInst & Inst,
262                                                   unsigned Insn,
263                                                   uint64_t Adddress,
264                                                   const void *Decoder);
265 static DecodeStatus DecodeT2MOVTWInstruction(MCInst &Inst, unsigned Insn,
266                                uint64_t Address, const void *Decoder);
267 static DecodeStatus DecodeArmMOVTWInstruction(MCInst &Inst, unsigned Insn,
268                                uint64_t Address, const void *Decoder);
269 static DecodeStatus DecodeSMLAInstruction(MCInst &Inst, unsigned Insn,
270                                uint64_t Address, const void *Decoder);
271 static DecodeStatus DecodeHINTInstruction(MCInst &Inst, unsigned Insn,
272                                uint64_t Address, const void *Decoder);
273 static DecodeStatus DecodeCPSInstruction(MCInst &Inst, unsigned Insn,
274                                uint64_t Address, const void *Decoder);
275 static DecodeStatus DecodeTSTInstruction(MCInst &Inst, unsigned Insn,
276                                uint64_t Address, const void *Decoder);
277 static DecodeStatus DecodeSETPANInstruction(MCInst &Inst, unsigned Insn,
278                                uint64_t Address, const void *Decoder);
279 static DecodeStatus DecodeT2CPSInstruction(MCInst &Inst, unsigned Insn,
280                                uint64_t Address, const void *Decoder);
281 static DecodeStatus DecodeAddrModeImm12Operand(MCInst &Inst, unsigned Val,
282                                uint64_t Address, const void *Decoder);
283 static DecodeStatus DecodeAddrMode5Operand(MCInst &Inst, unsigned Val,
284                                uint64_t Address, const void *Decoder);
285 static DecodeStatus DecodeAddrMode5FP16Operand(MCInst &Inst, unsigned Val,
286                                uint64_t Address, const void *Decoder);
287 static DecodeStatus DecodeAddrMode7Operand(MCInst &Inst, unsigned Val,
288                                uint64_t Address, const void *Decoder);
289 static DecodeStatus DecodeT2BInstruction(MCInst &Inst, unsigned Insn,
290                                uint64_t Address, const void *Decoder);
291 static DecodeStatus DecodeBranchImmInstruction(MCInst &Inst,unsigned Insn,
292                                uint64_t Address, const void *Decoder);
293 static DecodeStatus DecodeAddrMode6Operand(MCInst &Inst, unsigned Val,
294                                uint64_t Address, const void *Decoder);
295 static DecodeStatus DecodeVLDST1Instruction(MCInst &Inst, unsigned Val,
296                                uint64_t Address, const void *Decoder);
297 static DecodeStatus DecodeVLDST2Instruction(MCInst &Inst, unsigned Val,
298                                uint64_t Address, const void *Decoder);
299 static DecodeStatus DecodeVLDST3Instruction(MCInst &Inst, unsigned Val,
300                                uint64_t Address, const void *Decoder);
301 static DecodeStatus DecodeVLDST4Instruction(MCInst &Inst, unsigned Val,
302                                uint64_t Address, const void *Decoder);
303 static DecodeStatus DecodeVLDInstruction(MCInst &Inst, unsigned Val,
304                                uint64_t Address, const void *Decoder);
305 static DecodeStatus DecodeVSTInstruction(MCInst &Inst, unsigned Val,
306                                uint64_t Address, const void *Decoder);
307 static DecodeStatus DecodeVLD1DupInstruction(MCInst &Inst, unsigned Val,
308                                uint64_t Address, const void *Decoder);
309 static DecodeStatus DecodeVLD2DupInstruction(MCInst &Inst, unsigned Val,
310                                uint64_t Address, const void *Decoder);
311 static DecodeStatus DecodeVLD3DupInstruction(MCInst &Inst, unsigned Val,
312                                uint64_t Address, const void *Decoder);
313 static DecodeStatus DecodeVLD4DupInstruction(MCInst &Inst, unsigned Val,
314                                uint64_t Address, const void *Decoder);
315 static DecodeStatus DecodeNEONModImmInstruction(MCInst &Inst,unsigned Val,
316                                uint64_t Address, const void *Decoder);
317 static DecodeStatus DecodeMVEModImmInstruction(MCInst &Inst,unsigned Val,
318                                uint64_t Address, const void *Decoder);
319 static DecodeStatus DecodeMVEVADCInstruction(MCInst &Inst, unsigned Insn,
320                                uint64_t Address, const void *Decoder);
321 static DecodeStatus DecodeVSHLMaxInstruction(MCInst &Inst, unsigned Val,
322                                uint64_t Address, const void *Decoder);
323 static DecodeStatus DecodeShiftRight8Imm(MCInst &Inst, unsigned Val,
324                                uint64_t Address, const void *Decoder);
325 static DecodeStatus DecodeShiftRight16Imm(MCInst &Inst, unsigned Val,
326                                uint64_t Address, const void *Decoder);
327 static DecodeStatus DecodeShiftRight32Imm(MCInst &Inst, unsigned Val,
328                                uint64_t Address, const void *Decoder);
329 static DecodeStatus DecodeShiftRight64Imm(MCInst &Inst, unsigned Val,
330                                uint64_t Address, const void *Decoder);
331 static DecodeStatus DecodeTBLInstruction(MCInst &Inst, unsigned Insn,
332                                uint64_t Address, const void *Decoder);
333 static DecodeStatus DecodePostIdxReg(MCInst &Inst, unsigned Insn,
334                                uint64_t Address, const void *Decoder);
335 static DecodeStatus DecodeMveAddrModeRQ(MCInst &Inst, unsigned Insn,
336                                uint64_t Address, const void *Decoder);
337 template<int shift>
338 static DecodeStatus DecodeMveAddrModeQ(MCInst &Inst, unsigned Insn,
339                                uint64_t Address, const void *Decoder);
340 static DecodeStatus DecodeCoprocessor(MCInst &Inst, unsigned Insn,
341                                uint64_t Address, const void *Decoder);
342 static DecodeStatus DecodeMemBarrierOption(MCInst &Inst, unsigned Insn,
343                                uint64_t Address, const void *Decoder);
344 static DecodeStatus DecodeInstSyncBarrierOption(MCInst &Inst, unsigned Insn,
345                                uint64_t Address, const void *Decoder);
346 static DecodeStatus DecodeMSRMask(MCInst &Inst, unsigned Insn,
347                                uint64_t Address, const void *Decoder);
348 static DecodeStatus DecodeBankedReg(MCInst &Inst, unsigned Insn,
349                                uint64_t Address, const void *Decoder);
350 static DecodeStatus DecodeDoubleRegLoad(MCInst &Inst, unsigned Insn,
351                                uint64_t Address, const void *Decoder);
352 static DecodeStatus DecodeDoubleRegStore(MCInst &Inst, unsigned Insn,
353                                uint64_t Address, const void *Decoder);
354 static DecodeStatus DecodeLDRPreImm(MCInst &Inst, unsigned Insn,
355                                uint64_t Address, const void *Decoder);
356 static DecodeStatus DecodeLDRPreReg(MCInst &Inst, unsigned Insn,
357                                uint64_t Address, const void *Decoder);
358 static DecodeStatus DecodeSTRPreImm(MCInst &Inst, unsigned Insn,
359                                uint64_t Address, const void *Decoder);
360 static DecodeStatus DecodeSTRPreReg(MCInst &Inst, unsigned Insn,
361                                uint64_t Address, const void *Decoder);
362 static DecodeStatus DecodeVLD1LN(MCInst &Inst, unsigned Insn,
363                                uint64_t Address, const void *Decoder);
364 static DecodeStatus DecodeVLD2LN(MCInst &Inst, unsigned Insn,
365                                uint64_t Address, const void *Decoder);
366 static DecodeStatus DecodeVLD3LN(MCInst &Inst, unsigned Insn,
367                                uint64_t Address, const void *Decoder);
368 static DecodeStatus DecodeVLD4LN(MCInst &Inst, unsigned Insn,
369                                uint64_t Address, const void *Decoder);
370 static DecodeStatus DecodeVST1LN(MCInst &Inst, unsigned Insn,
371                                uint64_t Address, const void *Decoder);
372 static DecodeStatus DecodeVST2LN(MCInst &Inst, unsigned Insn,
373                                uint64_t Address, const void *Decoder);
374 static DecodeStatus DecodeVST3LN(MCInst &Inst, unsigned Insn,
375                                uint64_t Address, const void *Decoder);
376 static DecodeStatus DecodeVST4LN(MCInst &Inst, unsigned Insn,
377                                uint64_t Address, const void *Decoder);
378 static DecodeStatus DecodeVMOVSRR(MCInst &Inst, unsigned Insn,
379                                uint64_t Address, const void *Decoder);
380 static DecodeStatus DecodeVMOVRRS(MCInst &Inst, unsigned Insn,
381                                uint64_t Address, const void *Decoder);
382 static DecodeStatus DecodeSwap(MCInst &Inst, unsigned Insn,
383                                uint64_t Address, const void *Decoder);
384 static DecodeStatus DecodeVCVTD(MCInst &Inst, unsigned Insn,
385                                 uint64_t Address, const void *Decoder);
386 static DecodeStatus DecodeVCVTQ(MCInst &Inst, unsigned Insn,
387                                 uint64_t Address, const void *Decoder);
388 static DecodeStatus DecodeVCVTImmOperand(MCInst &Inst, unsigned Insn,
389                                          uint64_t Address, const void *Decoder);
390 static DecodeStatus DecodeNEONComplexLane64Instruction(MCInst &Inst,
391                                                        unsigned Val,
392                                                        uint64_t Address,
393                                                        const void *Decoder);
394 
395 static DecodeStatus DecodeThumbAddSpecialReg(MCInst &Inst, uint16_t Insn,
396                                uint64_t Address, const void *Decoder);
397 static DecodeStatus DecodeThumbBROperand(MCInst &Inst, unsigned Val,
398                                uint64_t Address, const void *Decoder);
399 static DecodeStatus DecodeT2BROperand(MCInst &Inst, unsigned Val,
400                                uint64_t Address, const void *Decoder);
401 static DecodeStatus DecodeThumbCmpBROperand(MCInst &Inst, unsigned Val,
402                                uint64_t Address, const void *Decoder);
403 static DecodeStatus DecodeThumbAddrModeRR(MCInst &Inst, unsigned Val,
404                                uint64_t Address, const void *Decoder);
405 static DecodeStatus DecodeThumbAddrModeIS(MCInst &Inst, unsigned Val,
406                                uint64_t Address, const void *Decoder);
407 static DecodeStatus DecodeThumbAddrModePC(MCInst &Inst, unsigned Val,
408                                uint64_t Address, const void *Decoder);
409 static DecodeStatus DecodeThumbAddrModeSP(MCInst &Inst, unsigned Val,
410                                uint64_t Address, const void *Decoder);
411 static DecodeStatus DecodeT2AddrModeSOReg(MCInst &Inst, unsigned Val,
412                                uint64_t Address, const void *Decoder);
413 static DecodeStatus DecodeT2LoadShift(MCInst &Inst, unsigned Val,
414                                uint64_t Address, const void *Decoder);
415 static DecodeStatus DecodeT2LoadImm8(MCInst &Inst, unsigned Insn,
416                                uint64_t Address, const void* Decoder);
417 static DecodeStatus DecodeT2LoadImm12(MCInst &Inst, unsigned Insn,
418                                uint64_t Address, const void* Decoder);
419 static DecodeStatus DecodeT2LoadT(MCInst &Inst, unsigned Insn,
420                                uint64_t Address, const void* Decoder);
421 static DecodeStatus DecodeT2LoadLabel(MCInst &Inst, unsigned Insn,
422                                uint64_t Address, const void* Decoder);
423 static DecodeStatus DecodeT2Imm8S4(MCInst &Inst, unsigned Val,
424                                uint64_t Address, const void *Decoder);
425 static DecodeStatus DecodeT2Imm7S4(MCInst &Inst, unsigned Val,
426                                uint64_t Address, const void *Decoder);
427 static DecodeStatus DecodeT2AddrModeImm8s4(MCInst &Inst, unsigned Val,
428                                uint64_t Address, const void *Decoder);
429 static DecodeStatus DecodeT2AddrModeImm7s4(MCInst &Inst, unsigned Val,
430                                            uint64_t Address,
431                                            const void *Decoder);
432 static DecodeStatus DecodeT2AddrModeImm0_1020s4(MCInst &Inst,unsigned Val,
433                                uint64_t Address, const void *Decoder);
434 static DecodeStatus DecodeT2Imm8(MCInst &Inst, unsigned Val,
435                                uint64_t Address, const void *Decoder);
436 template<int shift>
437 static DecodeStatus DecodeT2Imm7(MCInst &Inst, unsigned Val,
438                                uint64_t Address, const void *Decoder);
439 static DecodeStatus DecodeT2AddrModeImm8(MCInst &Inst, unsigned Val,
440                                uint64_t Address, const void *Decoder);
441 template<int shift>
442 static DecodeStatus DecodeTAddrModeImm7(MCInst &Inst, unsigned Val,
443                                uint64_t Address, const void *Decoder);
444 template<int shift, int WriteBack>
445 static DecodeStatus DecodeT2AddrModeImm7(MCInst &Inst, unsigned Val,
446                                uint64_t Address, const void *Decoder);
447 static DecodeStatus DecodeThumbAddSPImm(MCInst &Inst, uint16_t Val,
448                                uint64_t Address, const void *Decoder);
449 static DecodeStatus DecodeThumbAddSPReg(MCInst &Inst, uint16_t Insn,
450                                 uint64_t Address, const void *Decoder);
451 static DecodeStatus DecodeThumbCPS(MCInst &Inst, uint16_t Insn,
452                                 uint64_t Address, const void *Decoder);
453 static DecodeStatus DecodeQADDInstruction(MCInst &Inst, unsigned Insn,
454                                 uint64_t Address, const void *Decoder);
455 static DecodeStatus DecodeThumbBLXOffset(MCInst &Inst, unsigned Insn,
456                                 uint64_t Address, const void *Decoder);
457 static DecodeStatus DecodeT2AddrModeImm12(MCInst &Inst, unsigned Val,
458                                 uint64_t Address, const void *Decoder);
459 static DecodeStatus DecodeThumbTableBranch(MCInst &Inst, unsigned Val,
460                                 uint64_t Address, const void *Decoder);
461 static DecodeStatus DecodeThumb2BCCInstruction(MCInst &Inst, unsigned Val,
462                                 uint64_t Address, const void *Decoder);
463 static DecodeStatus DecodeT2SOImm(MCInst &Inst, unsigned Val,
464                                 uint64_t Address, const void *Decoder);
465 static DecodeStatus DecodeThumbBCCTargetOperand(MCInst &Inst,unsigned Val,
466                                 uint64_t Address, const void *Decoder);
467 static DecodeStatus DecodeThumbBLTargetOperand(MCInst &Inst, unsigned Val,
468                                 uint64_t Address, const void *Decoder);
469 static DecodeStatus DecodeIT(MCInst &Inst, unsigned Val,
470                                 uint64_t Address, const void *Decoder);
471 static DecodeStatus DecodeT2LDRDPreInstruction(MCInst &Inst,unsigned Insn,
472                                uint64_t Address, const void *Decoder);
473 static DecodeStatus DecodeT2STRDPreInstruction(MCInst &Inst,unsigned Insn,
474                                uint64_t Address, const void *Decoder);
475 static DecodeStatus DecodeT2Adr(MCInst &Inst, unsigned Val,
476                                 uint64_t Address, const void *Decoder);
477 static DecodeStatus DecodeT2LdStPre(MCInst &Inst, unsigned Val,
478                                 uint64_t Address, const void *Decoder);
479 static DecodeStatus DecodeT2ShifterImmOperand(MCInst &Inst, unsigned Val,
480                                 uint64_t Address, const void *Decoder);
481 
482 static DecodeStatus DecodeLDR(MCInst &Inst, unsigned Val,
483                                 uint64_t Address, const void *Decoder);
484 static DecodeStatus DecoderForMRRC2AndMCRR2(MCInst &Inst, unsigned Val,
485                                             uint64_t Address, const void *Decoder);
486 static DecodeStatus DecodeForVMRSandVMSR(MCInst &Inst, unsigned Val,
487                                          uint64_t Address, const void *Decoder);
488 
489 template <bool isSigned, bool isNeg, int size>
490 static DecodeStatus DecodeBFLabelOperand(MCInst &Inst, unsigned val,
491                                          uint64_t Address, const void *Decoder);
492 static DecodeStatus DecodeBFAfterTargetOperand(MCInst &Inst, unsigned val,
493                                                uint64_t Address,
494                                                const void *Decoder);
495 static DecodeStatus DecodePredNoALOperand(MCInst &Inst, unsigned Val,
496                                           uint64_t Address,
497                                           const void *Decoder);
498 static DecodeStatus DecodeLOLoop(MCInst &Inst, unsigned Insn, uint64_t Address,
499                                  const void *Decoder);
500 static DecodeStatus DecodeLongShiftOperand(MCInst &Inst, unsigned Val,
501                                            uint64_t Address,
502                                            const void *Decoder);
503 static DecodeStatus DecodeVSCCLRM(MCInst &Inst, unsigned Insn, uint64_t Address,
504                                   const void *Decoder);
505 static DecodeStatus DecodeVPTMaskOperand(MCInst &Inst, unsigned Val,
506                                          uint64_t Address, const void *Decoder);
507 static DecodeStatus DecodeVpredROperand(MCInst &Inst, unsigned Val,
508                                         uint64_t Address, const void *Decoder);
509 static DecodeStatus DecodeRestrictedIPredicateOperand(MCInst &Inst, unsigned Val,
510                                                      uint64_t Address,
511                                                      const void *Decoder);
512 static DecodeStatus DecodeRestrictedSPredicateOperand(MCInst &Inst, unsigned Val,
513                                                      uint64_t Address,
514                                                      const void *Decoder);
515 static DecodeStatus DecodeRestrictedUPredicateOperand(MCInst &Inst, unsigned Val,
516                                                      uint64_t Address,
517                                                      const void *Decoder);
518 static DecodeStatus DecodeRestrictedFPPredicateOperand(MCInst &Inst,
519                                                        unsigned Val,
520                                                        uint64_t Address,
521                                                        const void *Decoder);
522 template<bool Writeback>
523 static DecodeStatus DecodeVSTRVLDR_SYSREG(MCInst &Inst, unsigned Insn,
524                                           uint64_t Address,
525                                           const void *Decoder);
526 template<int shift>
527 static DecodeStatus DecodeMVE_MEM_1_pre(MCInst &Inst, unsigned Val,
528                                         uint64_t Address, const void *Decoder);
529 template<int shift>
530 static DecodeStatus DecodeMVE_MEM_2_pre(MCInst &Inst, unsigned Val,
531                                         uint64_t Address, const void *Decoder);
532 template<int shift>
533 static DecodeStatus DecodeMVE_MEM_3_pre(MCInst &Inst, unsigned Val,
534                                         uint64_t Address, const void *Decoder);
535 template<unsigned MinLog, unsigned MaxLog>
536 static DecodeStatus DecodePowerTwoOperand(MCInst &Inst, unsigned Val,
537                                           uint64_t Address,
538                                           const void *Decoder);
539 template <int shift>
540 static DecodeStatus DecodeExpandedImmOperand(MCInst &Inst, unsigned Val,
541                                              uint64_t Address,
542                                              const void *Decoder);
543 template<unsigned start>
544 static DecodeStatus DecodeMVEPairVectorIndexOperand(MCInst &Inst, unsigned Val,
545                                                     uint64_t Address,
546                                                     const void *Decoder);
547 static DecodeStatus DecodeMVEVMOVQtoDReg(MCInst &Inst, unsigned Insn,
548                                          uint64_t Address,
549                                          const void *Decoder);
550 static DecodeStatus DecodeMVEVMOVDRegtoQ(MCInst &Inst, unsigned Insn,
551                                          uint64_t Address,
552                                          const void *Decoder);
553 static DecodeStatus DecodeMVEVCVTt1fp(MCInst &Inst, unsigned Insn,
554                                       uint64_t Address, const void *Decoder);
555 typedef DecodeStatus OperandDecoder(MCInst &Inst, unsigned Val,
556                                     uint64_t Address, const void *Decoder);
557 template<bool scalar, OperandDecoder predicate_decoder>
558 static DecodeStatus DecodeMVEVCMP(MCInst &Inst, unsigned Insn,
559                                   uint64_t Address, const void *Decoder);
560 static DecodeStatus DecodeMveVCTP(MCInst &Inst, unsigned Insn,
561                                   uint64_t Address, const void *Decoder);
562 static DecodeStatus DecodeMVEOverlappingLongShift(MCInst &Inst, unsigned Insn,
563                                                   uint64_t Address,
564                                                   const void *Decoder);
565 #include "ARMGenDisassemblerTables.inc"
566 
567 static MCDisassembler *createARMDisassembler(const Target &T,
568                                              const MCSubtargetInfo &STI,
569                                              MCContext &Ctx) {
570   return new ARMDisassembler(STI, Ctx);
571 }
572 
573 // Post-decoding checks
574 static DecodeStatus checkDecodedInstruction(MCInst &MI, uint64_t &Size,
575                                             uint64_t Address, raw_ostream &OS,
576                                             raw_ostream &CS,
577                                             uint32_t Insn,
578                                             DecodeStatus Result) {
579   switch (MI.getOpcode()) {
580     case ARM::HVC: {
581       // HVC is undefined if condition = 0xf otherwise upredictable
582       // if condition != 0xe
583       uint32_t Cond = (Insn >> 28) & 0xF;
584       if (Cond == 0xF)
585         return MCDisassembler::Fail;
586       if (Cond != 0xE)
587         return MCDisassembler::SoftFail;
588       return Result;
589     }
590     case ARM::t2ADDri:
591     case ARM::t2ADDri12:
592     case ARM::t2ADDrr:
593     case ARM::t2ADDrs:
594     case ARM::t2SUBri:
595     case ARM::t2SUBri12:
596     case ARM::t2SUBrr:
597     case ARM::t2SUBrs:
598       if (MI.getOperand(0).getReg() == ARM::SP &&
599           MI.getOperand(1).getReg() != ARM::SP)
600         return MCDisassembler::SoftFail;
601       return Result;
602     default: return Result;
603   }
604 }
605 
606 DecodeStatus ARMDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
607                                              ArrayRef<uint8_t> Bytes,
608                                              uint64_t Address, raw_ostream &OS,
609                                              raw_ostream &CS) const {
610   if (STI.getFeatureBits()[ARM::ModeThumb])
611     return getThumbInstruction(MI, Size, Bytes, Address, OS, CS);
612   return getARMInstruction(MI, Size, Bytes, Address, OS, CS);
613 }
614 
615 DecodeStatus ARMDisassembler::getARMInstruction(MCInst &MI, uint64_t &Size,
616                                                 ArrayRef<uint8_t> Bytes,
617                                                 uint64_t Address,
618                                                 raw_ostream &OS,
619                                                 raw_ostream &CS) const {
620   CommentStream = &CS;
621 
622   assert(!STI.getFeatureBits()[ARM::ModeThumb] &&
623          "Asked to disassemble an ARM instruction but Subtarget is in Thumb "
624          "mode!");
625 
626   // We want to read exactly 4 bytes of data.
627   if (Bytes.size() < 4) {
628     Size = 0;
629     return MCDisassembler::Fail;
630   }
631 
632   // Encoded as a small-endian 32-bit word in the stream.
633   uint32_t Insn =
634       (Bytes[3] << 24) | (Bytes[2] << 16) | (Bytes[1] << 8) | (Bytes[0] << 0);
635 
636   // Calling the auto-generated decoder function.
637   DecodeStatus Result =
638       decodeInstruction(DecoderTableARM32, MI, Insn, Address, this, STI);
639   if (Result != MCDisassembler::Fail) {
640     Size = 4;
641     return checkDecodedInstruction(MI, Size, Address, OS, CS, Insn, Result);
642   }
643 
644   struct DecodeTable {
645     const uint8_t *P;
646     bool DecodePred;
647   };
648 
649   const DecodeTable Tables[] = {
650       {DecoderTableVFP32, false},      {DecoderTableVFPV832, false},
651       {DecoderTableNEONData32, true},  {DecoderTableNEONLoadStore32, true},
652       {DecoderTableNEONDup32, true},   {DecoderTablev8NEON32, false},
653       {DecoderTablev8Crypto32, false},
654   };
655 
656   for (auto Table : Tables) {
657     Result = decodeInstruction(Table.P, MI, Insn, Address, this, STI);
658     if (Result != MCDisassembler::Fail) {
659       Size = 4;
660       // Add a fake predicate operand, because we share these instruction
661       // definitions with Thumb2 where these instructions are predicable.
662       if (Table.DecodePred && !DecodePredicateOperand(MI, 0xE, Address, this))
663         return MCDisassembler::Fail;
664       return Result;
665     }
666   }
667 
668   Result =
669       decodeInstruction(DecoderTableCoProc32, MI, Insn, Address, this, STI);
670   if (Result != MCDisassembler::Fail) {
671     Size = 4;
672     return checkDecodedInstruction(MI, Size, Address, OS, CS, Insn, Result);
673   }
674 
675   Size = 4;
676   return MCDisassembler::Fail;
677 }
678 
679 namespace llvm {
680 
681 extern const MCInstrDesc ARMInsts[];
682 
683 } // end namespace llvm
684 
685 /// tryAddingSymbolicOperand - trys to add a symbolic operand in place of the
686 /// immediate Value in the MCInst.  The immediate Value has had any PC
687 /// adjustment made by the caller.  If the instruction is a branch instruction
688 /// then isBranch is true, else false.  If the getOpInfo() function was set as
689 /// part of the setupForSymbolicDisassembly() call then that function is called
690 /// to get any symbolic information at the Address for this instruction.  If
691 /// that returns non-zero then the symbolic information it returns is used to
692 /// create an MCExpr and that is added as an operand to the MCInst.  If
693 /// getOpInfo() returns zero and isBranch is true then a symbol look up for
694 /// Value is done and if a symbol is found an MCExpr is created with that, else
695 /// an MCExpr with Value is created.  This function returns true if it adds an
696 /// operand to the MCInst and false otherwise.
697 static bool tryAddingSymbolicOperand(uint64_t Address, int32_t Value,
698                                      bool isBranch, uint64_t InstSize,
699                                      MCInst &MI, const void *Decoder) {
700   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
701   // FIXME: Does it make sense for value to be negative?
702   return Dis->tryAddingSymbolicOperand(MI, (uint32_t)Value, Address, isBranch,
703                                        /* Offset */ 0, InstSize);
704 }
705 
706 /// tryAddingPcLoadReferenceComment - trys to add a comment as to what is being
707 /// referenced by a load instruction with the base register that is the Pc.
708 /// These can often be values in a literal pool near the Address of the
709 /// instruction.  The Address of the instruction and its immediate Value are
710 /// used as a possible literal pool entry.  The SymbolLookUp call back will
711 /// return the name of a symbol referenced by the literal pool's entry if
712 /// the referenced address is that of a symbol.  Or it will return a pointer to
713 /// a literal 'C' string if the referenced address of the literal pool's entry
714 /// is an address into a section with 'C' string literals.
715 static void tryAddingPcLoadReferenceComment(uint64_t Address, int Value,
716                                             const void *Decoder) {
717   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
718   Dis->tryAddingPcLoadReferenceComment(Value, Address);
719 }
720 
721 // Thumb1 instructions don't have explicit S bits.  Rather, they
722 // implicitly set CPSR.  Since it's not represented in the encoding, the
723 // auto-generated decoder won't inject the CPSR operand.  We need to fix
724 // that as a post-pass.
725 static void AddThumb1SBit(MCInst &MI, bool InITBlock) {
726   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
727   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
728   MCInst::iterator I = MI.begin();
729   for (unsigned i = 0; i < NumOps; ++i, ++I) {
730     if (I == MI.end()) break;
731     if (OpInfo[i].isOptionalDef() && OpInfo[i].RegClass == ARM::CCRRegClassID) {
732       if (i > 0 && OpInfo[i-1].isPredicate()) continue;
733       MI.insert(I, MCOperand::createReg(InITBlock ? 0 : ARM::CPSR));
734       return;
735     }
736   }
737 
738   MI.insert(I, MCOperand::createReg(InITBlock ? 0 : ARM::CPSR));
739 }
740 
741 static bool isVectorPredicable(unsigned Opcode) {
742   const MCOperandInfo *OpInfo = ARMInsts[Opcode].OpInfo;
743   unsigned short NumOps = ARMInsts[Opcode].NumOperands;
744   for (unsigned i = 0; i < NumOps; ++i) {
745     if (ARM::isVpred(OpInfo[i].OperandType))
746       return true;
747   }
748   return false;
749 }
750 
751 // Most Thumb instructions don't have explicit predicates in the
752 // encoding, but rather get their predicates from IT context.  We need
753 // to fix up the predicate operands using this context information as a
754 // post-pass.
755 MCDisassembler::DecodeStatus
756 ARMDisassembler::AddThumbPredicate(MCInst &MI) const {
757   MCDisassembler::DecodeStatus S = Success;
758 
759   const FeatureBitset &FeatureBits = getSubtargetInfo().getFeatureBits();
760 
761   // A few instructions actually have predicates encoded in them.  Don't
762   // try to overwrite it if we're seeing one of those.
763   switch (MI.getOpcode()) {
764     case ARM::tBcc:
765     case ARM::t2Bcc:
766     case ARM::tCBZ:
767     case ARM::tCBNZ:
768     case ARM::tCPS:
769     case ARM::t2CPS3p:
770     case ARM::t2CPS2p:
771     case ARM::t2CPS1p:
772     case ARM::t2CSEL:
773     case ARM::t2CSINC:
774     case ARM::t2CSINV:
775     case ARM::t2CSNEG:
776     case ARM::tMOVSr:
777     case ARM::tSETEND:
778       // Some instructions (mostly conditional branches) are not
779       // allowed in IT blocks.
780       if (ITBlock.instrInITBlock())
781         S = SoftFail;
782       else
783         return Success;
784       break;
785     case ARM::t2HINT:
786       if (MI.getOperand(0).getImm() == 0x10 && (FeatureBits[ARM::FeatureRAS]) != 0)
787         S = SoftFail;
788       break;
789     case ARM::tB:
790     case ARM::t2B:
791     case ARM::t2TBB:
792     case ARM::t2TBH:
793       // Some instructions (mostly unconditional branches) can
794       // only appears at the end of, or outside of, an IT.
795       if (ITBlock.instrInITBlock() && !ITBlock.instrLastInITBlock())
796         S = SoftFail;
797       break;
798     default:
799       break;
800   }
801 
802   // Warn on non-VPT predicable instruction in a VPT block and a VPT
803   // predicable instruction in an IT block
804   if ((!isVectorPredicable(MI.getOpcode()) && VPTBlock.instrInVPTBlock()) ||
805        (isVectorPredicable(MI.getOpcode()) && ITBlock.instrInITBlock()))
806     S = SoftFail;
807 
808   // If we're in an IT/VPT block, base the predicate on that.  Otherwise,
809   // assume a predicate of AL.
810   unsigned CC = ARMCC::AL;
811   unsigned VCC = ARMVCC::None;
812   if (ITBlock.instrInITBlock()) {
813     CC = ITBlock.getITCC();
814     ITBlock.advanceITState();
815   } else if (VPTBlock.instrInVPTBlock()) {
816     VCC = VPTBlock.getVPTPred();
817     VPTBlock.advanceVPTState();
818   }
819 
820   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
821   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
822 
823   MCInst::iterator CCI = MI.begin();
824   for (unsigned i = 0; i < NumOps; ++i, ++CCI) {
825     if (OpInfo[i].isPredicate() || CCI == MI.end()) break;
826   }
827 
828   if (ARMInsts[MI.getOpcode()].isPredicable()) {
829     CCI = MI.insert(CCI, MCOperand::createImm(CC));
830     ++CCI;
831     if (CC == ARMCC::AL)
832       MI.insert(CCI, MCOperand::createReg(0));
833     else
834       MI.insert(CCI, MCOperand::createReg(ARM::CPSR));
835   } else if (CC != ARMCC::AL) {
836     Check(S, SoftFail);
837   }
838 
839   MCInst::iterator VCCI = MI.begin();
840   unsigned VCCPos;
841   for (VCCPos = 0; VCCPos < NumOps; ++VCCPos, ++VCCI) {
842     if (ARM::isVpred(OpInfo[VCCPos].OperandType) || VCCI == MI.end()) break;
843   }
844 
845   if (isVectorPredicable(MI.getOpcode())) {
846     VCCI = MI.insert(VCCI, MCOperand::createImm(VCC));
847     ++VCCI;
848     if (VCC == ARMVCC::None)
849       MI.insert(VCCI, MCOperand::createReg(0));
850     else
851       MI.insert(VCCI, MCOperand::createReg(ARM::P0));
852     if (OpInfo[VCCPos].OperandType == ARM::OPERAND_VPRED_R) {
853       int TiedOp = ARMInsts[MI.getOpcode()].getOperandConstraint(
854         VCCPos + 2, MCOI::TIED_TO);
855       assert(TiedOp >= 0 &&
856              "Inactive register in vpred_r is not tied to an output!");
857       MI.insert(VCCI, MI.getOperand(TiedOp));
858     }
859   } else if (VCC != ARMVCC::None) {
860     Check(S, SoftFail);
861   }
862 
863   return S;
864 }
865 
866 // Thumb VFP instructions are a special case.  Because we share their
867 // encodings between ARM and Thumb modes, and they are predicable in ARM
868 // mode, the auto-generated decoder will give them an (incorrect)
869 // predicate operand.  We need to rewrite these operands based on the IT
870 // context as a post-pass.
871 void ARMDisassembler::UpdateThumbVFPPredicate(
872   DecodeStatus &S, MCInst &MI) const {
873   unsigned CC;
874   CC = ITBlock.getITCC();
875   if (CC == 0xF)
876     CC = ARMCC::AL;
877   if (ITBlock.instrInITBlock())
878     ITBlock.advanceITState();
879   else if (VPTBlock.instrInVPTBlock()) {
880     CC = VPTBlock.getVPTPred();
881     VPTBlock.advanceVPTState();
882   }
883 
884   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
885   MCInst::iterator I = MI.begin();
886   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
887   for (unsigned i = 0; i < NumOps; ++i, ++I) {
888     if (OpInfo[i].isPredicate() ) {
889       if (CC != ARMCC::AL && !ARMInsts[MI.getOpcode()].isPredicable())
890         Check(S, SoftFail);
891       I->setImm(CC);
892       ++I;
893       if (CC == ARMCC::AL)
894         I->setReg(0);
895       else
896         I->setReg(ARM::CPSR);
897       return;
898     }
899   }
900 }
901 
902 DecodeStatus ARMDisassembler::getThumbInstruction(MCInst &MI, uint64_t &Size,
903                                                   ArrayRef<uint8_t> Bytes,
904                                                   uint64_t Address,
905                                                   raw_ostream &OS,
906                                                   raw_ostream &CS) const {
907   CommentStream = &CS;
908 
909   assert(STI.getFeatureBits()[ARM::ModeThumb] &&
910          "Asked to disassemble in Thumb mode but Subtarget is in ARM mode!");
911 
912   // We want to read exactly 2 bytes of data.
913   if (Bytes.size() < 2) {
914     Size = 0;
915     return MCDisassembler::Fail;
916   }
917 
918   uint16_t Insn16 = (Bytes[1] << 8) | Bytes[0];
919   DecodeStatus Result =
920       decodeInstruction(DecoderTableThumb16, MI, Insn16, Address, this, STI);
921   if (Result != MCDisassembler::Fail) {
922     Size = 2;
923     Check(Result, AddThumbPredicate(MI));
924     return Result;
925   }
926 
927   Result = decodeInstruction(DecoderTableThumbSBit16, MI, Insn16, Address, this,
928                              STI);
929   if (Result) {
930     Size = 2;
931     bool InITBlock = ITBlock.instrInITBlock();
932     Check(Result, AddThumbPredicate(MI));
933     AddThumb1SBit(MI, InITBlock);
934     return Result;
935   }
936 
937   Result =
938       decodeInstruction(DecoderTableThumb216, MI, Insn16, Address, this, STI);
939   if (Result != MCDisassembler::Fail) {
940     Size = 2;
941 
942     // Nested IT blocks are UNPREDICTABLE.  Must be checked before we add
943     // the Thumb predicate.
944     if (MI.getOpcode() == ARM::t2IT && ITBlock.instrInITBlock())
945       Result = MCDisassembler::SoftFail;
946 
947     Check(Result, AddThumbPredicate(MI));
948 
949     // If we find an IT instruction, we need to parse its condition
950     // code and mask operands so that we can apply them correctly
951     // to the subsequent instructions.
952     if (MI.getOpcode() == ARM::t2IT) {
953       unsigned Firstcond = MI.getOperand(0).getImm();
954       unsigned Mask = MI.getOperand(1).getImm();
955       ITBlock.setITState(Firstcond, Mask);
956 
957       // An IT instruction that would give a 'NV' predicate is unpredictable.
958       if (Firstcond == ARMCC::AL && !isPowerOf2_32(Mask))
959         CS << "unpredictable IT predicate sequence";
960     }
961 
962     return Result;
963   }
964 
965   // We want to read exactly 4 bytes of data.
966   if (Bytes.size() < 4) {
967     Size = 0;
968     return MCDisassembler::Fail;
969   }
970 
971   uint32_t Insn32 =
972       (Bytes[3] << 8) | (Bytes[2] << 0) | (Bytes[1] << 24) | (Bytes[0] << 16);
973 
974   Result =
975       decodeInstruction(DecoderTableMVE32, MI, Insn32, Address, this, STI);
976   if (Result != MCDisassembler::Fail) {
977     Size = 4;
978 
979     // Nested VPT blocks are UNPREDICTABLE. Must be checked before we add
980     // the VPT predicate.
981     if (isVPTOpcode(MI.getOpcode()) && VPTBlock.instrInVPTBlock())
982       Result = MCDisassembler::SoftFail;
983 
984     Check(Result, AddThumbPredicate(MI));
985 
986     if (isVPTOpcode(MI.getOpcode())) {
987       unsigned Mask = MI.getOperand(0).getImm();
988       VPTBlock.setVPTState(Mask);
989     }
990 
991     return Result;
992   }
993 
994   Result =
995       decodeInstruction(DecoderTableThumb32, MI, Insn32, Address, this, STI);
996   if (Result != MCDisassembler::Fail) {
997     Size = 4;
998     bool InITBlock = ITBlock.instrInITBlock();
999     Check(Result, AddThumbPredicate(MI));
1000     AddThumb1SBit(MI, InITBlock);
1001     return Result;
1002   }
1003 
1004   Result =
1005       decodeInstruction(DecoderTableThumb232, MI, Insn32, Address, this, STI);
1006   if (Result != MCDisassembler::Fail) {
1007     Size = 4;
1008     Check(Result, AddThumbPredicate(MI));
1009     return checkDecodedInstruction(MI, Size, Address, OS, CS, Insn32, Result);
1010   }
1011 
1012   if (fieldFromInstruction(Insn32, 28, 4) == 0xE) {
1013     Result =
1014         decodeInstruction(DecoderTableVFP32, MI, Insn32, Address, this, STI);
1015     if (Result != MCDisassembler::Fail) {
1016       Size = 4;
1017       UpdateThumbVFPPredicate(Result, MI);
1018       return Result;
1019     }
1020   }
1021 
1022   Result =
1023       decodeInstruction(DecoderTableVFPV832, MI, Insn32, Address, this, STI);
1024   if (Result != MCDisassembler::Fail) {
1025     Size = 4;
1026     return Result;
1027   }
1028 
1029   if (fieldFromInstruction(Insn32, 28, 4) == 0xE) {
1030     Result = decodeInstruction(DecoderTableNEONDup32, MI, Insn32, Address, this,
1031                                STI);
1032     if (Result != MCDisassembler::Fail) {
1033       Size = 4;
1034       Check(Result, AddThumbPredicate(MI));
1035       return Result;
1036     }
1037   }
1038 
1039   if (fieldFromInstruction(Insn32, 24, 8) == 0xF9) {
1040     uint32_t NEONLdStInsn = Insn32;
1041     NEONLdStInsn &= 0xF0FFFFFF;
1042     NEONLdStInsn |= 0x04000000;
1043     Result = decodeInstruction(DecoderTableNEONLoadStore32, MI, NEONLdStInsn,
1044                                Address, this, STI);
1045     if (Result != MCDisassembler::Fail) {
1046       Size = 4;
1047       Check(Result, AddThumbPredicate(MI));
1048       return Result;
1049     }
1050   }
1051 
1052   if (fieldFromInstruction(Insn32, 24, 4) == 0xF) {
1053     uint32_t NEONDataInsn = Insn32;
1054     NEONDataInsn &= 0xF0FFFFFF; // Clear bits 27-24
1055     NEONDataInsn |= (NEONDataInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
1056     NEONDataInsn |= 0x12000000; // Set bits 28 and 25
1057     Result = decodeInstruction(DecoderTableNEONData32, MI, NEONDataInsn,
1058                                Address, this, STI);
1059     if (Result != MCDisassembler::Fail) {
1060       Size = 4;
1061       Check(Result, AddThumbPredicate(MI));
1062       return Result;
1063     }
1064 
1065     uint32_t NEONCryptoInsn = Insn32;
1066     NEONCryptoInsn &= 0xF0FFFFFF; // Clear bits 27-24
1067     NEONCryptoInsn |= (NEONCryptoInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
1068     NEONCryptoInsn |= 0x12000000; // Set bits 28 and 25
1069     Result = decodeInstruction(DecoderTablev8Crypto32, MI, NEONCryptoInsn,
1070                                Address, this, STI);
1071     if (Result != MCDisassembler::Fail) {
1072       Size = 4;
1073       return Result;
1074     }
1075 
1076     uint32_t NEONv8Insn = Insn32;
1077     NEONv8Insn &= 0xF3FFFFFF; // Clear bits 27-26
1078     Result = decodeInstruction(DecoderTablev8NEON32, MI, NEONv8Insn, Address,
1079                                this, STI);
1080     if (Result != MCDisassembler::Fail) {
1081       Size = 4;
1082       return Result;
1083     }
1084   }
1085 
1086   Result =
1087       decodeInstruction(DecoderTableThumb2CoProc32, MI, Insn32, Address, this, STI);
1088   if (Result != MCDisassembler::Fail) {
1089     Size = 4;
1090     Check(Result, AddThumbPredicate(MI));
1091     return Result;
1092   }
1093 
1094   Size = 0;
1095   return MCDisassembler::Fail;
1096 }
1097 
1098 extern "C" void LLVMInitializeARMDisassembler() {
1099   TargetRegistry::RegisterMCDisassembler(getTheARMLETarget(),
1100                                          createARMDisassembler);
1101   TargetRegistry::RegisterMCDisassembler(getTheARMBETarget(),
1102                                          createARMDisassembler);
1103   TargetRegistry::RegisterMCDisassembler(getTheThumbLETarget(),
1104                                          createARMDisassembler);
1105   TargetRegistry::RegisterMCDisassembler(getTheThumbBETarget(),
1106                                          createARMDisassembler);
1107 }
1108 
1109 static const uint16_t GPRDecoderTable[] = {
1110   ARM::R0, ARM::R1, ARM::R2, ARM::R3,
1111   ARM::R4, ARM::R5, ARM::R6, ARM::R7,
1112   ARM::R8, ARM::R9, ARM::R10, ARM::R11,
1113   ARM::R12, ARM::SP, ARM::LR, ARM::PC
1114 };
1115 
1116 static const uint16_t CLRMGPRDecoderTable[] = {
1117   ARM::R0, ARM::R1, ARM::R2, ARM::R3,
1118   ARM::R4, ARM::R5, ARM::R6, ARM::R7,
1119   ARM::R8, ARM::R9, ARM::R10, ARM::R11,
1120   ARM::R12, 0, ARM::LR, ARM::APSR
1121 };
1122 
1123 static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1124                                    uint64_t Address, const void *Decoder) {
1125   if (RegNo > 15)
1126     return MCDisassembler::Fail;
1127 
1128   unsigned Register = GPRDecoderTable[RegNo];
1129   Inst.addOperand(MCOperand::createReg(Register));
1130   return MCDisassembler::Success;
1131 }
1132 
1133 static DecodeStatus DecodeCLRMGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1134                                                uint64_t Address,
1135                                                const void *Decoder) {
1136   if (RegNo > 15)
1137     return MCDisassembler::Fail;
1138 
1139   unsigned Register = CLRMGPRDecoderTable[RegNo];
1140   if (Register == 0)
1141     return MCDisassembler::Fail;
1142 
1143   Inst.addOperand(MCOperand::createReg(Register));
1144   return MCDisassembler::Success;
1145 }
1146 
1147 static DecodeStatus
1148 DecodeGPRnopcRegisterClass(MCInst &Inst, unsigned RegNo,
1149                            uint64_t Address, const void *Decoder) {
1150   DecodeStatus S = MCDisassembler::Success;
1151 
1152   if (RegNo == 15)
1153     S = MCDisassembler::SoftFail;
1154 
1155   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1156 
1157   return S;
1158 }
1159 
1160 static DecodeStatus
1161 DecodeGPRwithAPSRRegisterClass(MCInst &Inst, unsigned RegNo,
1162                                uint64_t Address, const void *Decoder) {
1163   DecodeStatus S = MCDisassembler::Success;
1164 
1165   if (RegNo == 15)
1166   {
1167     Inst.addOperand(MCOperand::createReg(ARM::APSR_NZCV));
1168     return MCDisassembler::Success;
1169   }
1170 
1171   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1172   return S;
1173 }
1174 
1175 static DecodeStatus
1176 DecodeGPRwithZRRegisterClass(MCInst &Inst, unsigned RegNo,
1177                              uint64_t Address, const void *Decoder) {
1178   DecodeStatus S = MCDisassembler::Success;
1179 
1180   if (RegNo == 15)
1181   {
1182     Inst.addOperand(MCOperand::createReg(ARM::ZR));
1183     return MCDisassembler::Success;
1184   }
1185 
1186   if (RegNo == 13)
1187     S = MCDisassembler::SoftFail;
1188 
1189   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1190   return S;
1191 }
1192 
1193 static DecodeStatus DecodetGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1194                                    uint64_t Address, const void *Decoder) {
1195   if (RegNo > 7)
1196     return MCDisassembler::Fail;
1197   return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
1198 }
1199 
1200 static const uint16_t GPRPairDecoderTable[] = {
1201   ARM::R0_R1, ARM::R2_R3,   ARM::R4_R5,  ARM::R6_R7,
1202   ARM::R8_R9, ARM::R10_R11, ARM::R12_SP
1203 };
1204 
1205 static DecodeStatus DecodeGPRPairRegisterClass(MCInst &Inst, unsigned RegNo,
1206                                    uint64_t Address, const void *Decoder) {
1207   DecodeStatus S = MCDisassembler::Success;
1208 
1209   if (RegNo > 13)
1210     return MCDisassembler::Fail;
1211 
1212   if ((RegNo & 1) || RegNo == 0xe)
1213      S = MCDisassembler::SoftFail;
1214 
1215   unsigned RegisterPair = GPRPairDecoderTable[RegNo/2];
1216   Inst.addOperand(MCOperand::createReg(RegisterPair));
1217   return S;
1218 }
1219 
1220 static DecodeStatus DecodetcGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1221                                    uint64_t Address, const void *Decoder) {
1222   unsigned Register = 0;
1223   switch (RegNo) {
1224     case 0:
1225       Register = ARM::R0;
1226       break;
1227     case 1:
1228       Register = ARM::R1;
1229       break;
1230     case 2:
1231       Register = ARM::R2;
1232       break;
1233     case 3:
1234       Register = ARM::R3;
1235       break;
1236     case 9:
1237       Register = ARM::R9;
1238       break;
1239     case 12:
1240       Register = ARM::R12;
1241       break;
1242     default:
1243       return MCDisassembler::Fail;
1244     }
1245 
1246   Inst.addOperand(MCOperand::createReg(Register));
1247   return MCDisassembler::Success;
1248 }
1249 
1250 static DecodeStatus DecoderGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1251                                    uint64_t Address, const void *Decoder) {
1252   DecodeStatus S = MCDisassembler::Success;
1253 
1254   const FeatureBitset &featureBits =
1255     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1256 
1257   if ((RegNo == 13 && !featureBits[ARM::HasV8Ops]) || RegNo == 15)
1258     S = MCDisassembler::SoftFail;
1259 
1260   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1261   return S;
1262 }
1263 
1264 static const uint16_t SPRDecoderTable[] = {
1265      ARM::S0,  ARM::S1,  ARM::S2,  ARM::S3,
1266      ARM::S4,  ARM::S5,  ARM::S6,  ARM::S7,
1267      ARM::S8,  ARM::S9, ARM::S10, ARM::S11,
1268     ARM::S12, ARM::S13, ARM::S14, ARM::S15,
1269     ARM::S16, ARM::S17, ARM::S18, ARM::S19,
1270     ARM::S20, ARM::S21, ARM::S22, ARM::S23,
1271     ARM::S24, ARM::S25, ARM::S26, ARM::S27,
1272     ARM::S28, ARM::S29, ARM::S30, ARM::S31
1273 };
1274 
1275 static DecodeStatus DecodeSPRRegisterClass(MCInst &Inst, unsigned RegNo,
1276                                    uint64_t Address, const void *Decoder) {
1277   if (RegNo > 31)
1278     return MCDisassembler::Fail;
1279 
1280   unsigned Register = SPRDecoderTable[RegNo];
1281   Inst.addOperand(MCOperand::createReg(Register));
1282   return MCDisassembler::Success;
1283 }
1284 
1285 static DecodeStatus DecodeHPRRegisterClass(MCInst &Inst, unsigned RegNo,
1286                                    uint64_t Address, const void *Decoder) {
1287   return DecodeSPRRegisterClass(Inst, RegNo, Address, Decoder);
1288 }
1289 
1290 static const uint16_t DPRDecoderTable[] = {
1291      ARM::D0,  ARM::D1,  ARM::D2,  ARM::D3,
1292      ARM::D4,  ARM::D5,  ARM::D6,  ARM::D7,
1293      ARM::D8,  ARM::D9, ARM::D10, ARM::D11,
1294     ARM::D12, ARM::D13, ARM::D14, ARM::D15,
1295     ARM::D16, ARM::D17, ARM::D18, ARM::D19,
1296     ARM::D20, ARM::D21, ARM::D22, ARM::D23,
1297     ARM::D24, ARM::D25, ARM::D26, ARM::D27,
1298     ARM::D28, ARM::D29, ARM::D30, ARM::D31
1299 };
1300 
1301 static DecodeStatus DecodeDPRRegisterClass(MCInst &Inst, unsigned RegNo,
1302                                    uint64_t Address, const void *Decoder) {
1303   const FeatureBitset &featureBits =
1304     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1305 
1306   bool hasD32 = featureBits[ARM::FeatureD32];
1307 
1308   if (RegNo > 31 || (!hasD32 && RegNo > 15))
1309     return MCDisassembler::Fail;
1310 
1311   unsigned Register = DPRDecoderTable[RegNo];
1312   Inst.addOperand(MCOperand::createReg(Register));
1313   return MCDisassembler::Success;
1314 }
1315 
1316 static DecodeStatus DecodeDPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
1317                                    uint64_t Address, const void *Decoder) {
1318   if (RegNo > 7)
1319     return MCDisassembler::Fail;
1320   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
1321 }
1322 
1323 static DecodeStatus DecodeSPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
1324                                    uint64_t Address, const void *Decoder) {
1325   if (RegNo > 15)
1326     return MCDisassembler::Fail;
1327   return DecodeSPRRegisterClass(Inst, RegNo, Address, Decoder);
1328 }
1329 
1330 static DecodeStatus
1331 DecodeDPR_VFP2RegisterClass(MCInst &Inst, unsigned RegNo,
1332                             uint64_t Address, const void *Decoder) {
1333   if (RegNo > 15)
1334     return MCDisassembler::Fail;
1335   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
1336 }
1337 
1338 static const uint16_t QPRDecoderTable[] = {
1339      ARM::Q0,  ARM::Q1,  ARM::Q2,  ARM::Q3,
1340      ARM::Q4,  ARM::Q5,  ARM::Q6,  ARM::Q7,
1341      ARM::Q8,  ARM::Q9, ARM::Q10, ARM::Q11,
1342     ARM::Q12, ARM::Q13, ARM::Q14, ARM::Q15
1343 };
1344 
1345 static DecodeStatus DecodeQPRRegisterClass(MCInst &Inst, unsigned RegNo,
1346                                    uint64_t Address, const void *Decoder) {
1347   if (RegNo > 31 || (RegNo & 1) != 0)
1348     return MCDisassembler::Fail;
1349   RegNo >>= 1;
1350 
1351   unsigned Register = QPRDecoderTable[RegNo];
1352   Inst.addOperand(MCOperand::createReg(Register));
1353   return MCDisassembler::Success;
1354 }
1355 
1356 static const uint16_t DPairDecoderTable[] = {
1357   ARM::Q0,  ARM::D1_D2,   ARM::Q1,  ARM::D3_D4,   ARM::Q2,  ARM::D5_D6,
1358   ARM::Q3,  ARM::D7_D8,   ARM::Q4,  ARM::D9_D10,  ARM::Q5,  ARM::D11_D12,
1359   ARM::Q6,  ARM::D13_D14, ARM::Q7,  ARM::D15_D16, ARM::Q8,  ARM::D17_D18,
1360   ARM::Q9,  ARM::D19_D20, ARM::Q10, ARM::D21_D22, ARM::Q11, ARM::D23_D24,
1361   ARM::Q12, ARM::D25_D26, ARM::Q13, ARM::D27_D28, ARM::Q14, ARM::D29_D30,
1362   ARM::Q15
1363 };
1364 
1365 static DecodeStatus DecodeDPairRegisterClass(MCInst &Inst, unsigned RegNo,
1366                                    uint64_t Address, const void *Decoder) {
1367   if (RegNo > 30)
1368     return MCDisassembler::Fail;
1369 
1370   unsigned Register = DPairDecoderTable[RegNo];
1371   Inst.addOperand(MCOperand::createReg(Register));
1372   return MCDisassembler::Success;
1373 }
1374 
1375 static const uint16_t DPairSpacedDecoderTable[] = {
1376   ARM::D0_D2,   ARM::D1_D3,   ARM::D2_D4,   ARM::D3_D5,
1377   ARM::D4_D6,   ARM::D5_D7,   ARM::D6_D8,   ARM::D7_D9,
1378   ARM::D8_D10,  ARM::D9_D11,  ARM::D10_D12, ARM::D11_D13,
1379   ARM::D12_D14, ARM::D13_D15, ARM::D14_D16, ARM::D15_D17,
1380   ARM::D16_D18, ARM::D17_D19, ARM::D18_D20, ARM::D19_D21,
1381   ARM::D20_D22, ARM::D21_D23, ARM::D22_D24, ARM::D23_D25,
1382   ARM::D24_D26, ARM::D25_D27, ARM::D26_D28, ARM::D27_D29,
1383   ARM::D28_D30, ARM::D29_D31
1384 };
1385 
1386 static DecodeStatus DecodeDPairSpacedRegisterClass(MCInst &Inst,
1387                                                    unsigned RegNo,
1388                                                    uint64_t Address,
1389                                                    const void *Decoder) {
1390   if (RegNo > 29)
1391     return MCDisassembler::Fail;
1392 
1393   unsigned Register = DPairSpacedDecoderTable[RegNo];
1394   Inst.addOperand(MCOperand::createReg(Register));
1395   return MCDisassembler::Success;
1396 }
1397 
1398 static DecodeStatus DecodePredicateOperand(MCInst &Inst, unsigned Val,
1399                                uint64_t Address, const void *Decoder) {
1400   DecodeStatus S = MCDisassembler::Success;
1401   if (Val == 0xF) return MCDisassembler::Fail;
1402   // AL predicate is not allowed on Thumb1 branches.
1403   if (Inst.getOpcode() == ARM::tBcc && Val == 0xE)
1404     return MCDisassembler::Fail;
1405   if (Val != ARMCC::AL && !ARMInsts[Inst.getOpcode()].isPredicable())
1406     Check(S, MCDisassembler::SoftFail);
1407   Inst.addOperand(MCOperand::createImm(Val));
1408   if (Val == ARMCC::AL) {
1409     Inst.addOperand(MCOperand::createReg(0));
1410   } else
1411     Inst.addOperand(MCOperand::createReg(ARM::CPSR));
1412   return S;
1413 }
1414 
1415 static DecodeStatus DecodeCCOutOperand(MCInst &Inst, unsigned Val,
1416                                uint64_t Address, const void *Decoder) {
1417   if (Val)
1418     Inst.addOperand(MCOperand::createReg(ARM::CPSR));
1419   else
1420     Inst.addOperand(MCOperand::createReg(0));
1421   return MCDisassembler::Success;
1422 }
1423 
1424 static DecodeStatus DecodeSORegImmOperand(MCInst &Inst, unsigned Val,
1425                                uint64_t Address, const void *Decoder) {
1426   DecodeStatus S = MCDisassembler::Success;
1427 
1428   unsigned Rm = fieldFromInstruction(Val, 0, 4);
1429   unsigned type = fieldFromInstruction(Val, 5, 2);
1430   unsigned imm = fieldFromInstruction(Val, 7, 5);
1431 
1432   // Register-immediate
1433   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
1434     return MCDisassembler::Fail;
1435 
1436   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1437   switch (type) {
1438     case 0:
1439       Shift = ARM_AM::lsl;
1440       break;
1441     case 1:
1442       Shift = ARM_AM::lsr;
1443       break;
1444     case 2:
1445       Shift = ARM_AM::asr;
1446       break;
1447     case 3:
1448       Shift = ARM_AM::ror;
1449       break;
1450   }
1451 
1452   if (Shift == ARM_AM::ror && imm == 0)
1453     Shift = ARM_AM::rrx;
1454 
1455   unsigned Op = Shift | (imm << 3);
1456   Inst.addOperand(MCOperand::createImm(Op));
1457 
1458   return S;
1459 }
1460 
1461 static DecodeStatus DecodeSORegRegOperand(MCInst &Inst, unsigned Val,
1462                                uint64_t Address, const void *Decoder) {
1463   DecodeStatus S = MCDisassembler::Success;
1464 
1465   unsigned Rm = fieldFromInstruction(Val, 0, 4);
1466   unsigned type = fieldFromInstruction(Val, 5, 2);
1467   unsigned Rs = fieldFromInstruction(Val, 8, 4);
1468 
1469   // Register-register
1470   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1471     return MCDisassembler::Fail;
1472   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rs, Address, Decoder)))
1473     return MCDisassembler::Fail;
1474 
1475   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1476   switch (type) {
1477     case 0:
1478       Shift = ARM_AM::lsl;
1479       break;
1480     case 1:
1481       Shift = ARM_AM::lsr;
1482       break;
1483     case 2:
1484       Shift = ARM_AM::asr;
1485       break;
1486     case 3:
1487       Shift = ARM_AM::ror;
1488       break;
1489   }
1490 
1491   Inst.addOperand(MCOperand::createImm(Shift));
1492 
1493   return S;
1494 }
1495 
1496 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Val,
1497                                  uint64_t Address, const void *Decoder) {
1498   DecodeStatus S = MCDisassembler::Success;
1499 
1500   bool NeedDisjointWriteback = false;
1501   unsigned WritebackReg = 0;
1502   bool CLRM = false;
1503   switch (Inst.getOpcode()) {
1504   default:
1505     break;
1506   case ARM::LDMIA_UPD:
1507   case ARM::LDMDB_UPD:
1508   case ARM::LDMIB_UPD:
1509   case ARM::LDMDA_UPD:
1510   case ARM::t2LDMIA_UPD:
1511   case ARM::t2LDMDB_UPD:
1512   case ARM::t2STMIA_UPD:
1513   case ARM::t2STMDB_UPD:
1514     NeedDisjointWriteback = true;
1515     WritebackReg = Inst.getOperand(0).getReg();
1516     break;
1517   case ARM::t2CLRM:
1518     CLRM = true;
1519     break;
1520   }
1521 
1522   // Empty register lists are not allowed.
1523   if (Val == 0) return MCDisassembler::Fail;
1524   for (unsigned i = 0; i < 16; ++i) {
1525     if (Val & (1 << i)) {
1526       if (CLRM) {
1527         if (!Check(S, DecodeCLRMGPRRegisterClass(Inst, i, Address, Decoder))) {
1528           return MCDisassembler::Fail;
1529         }
1530       } else {
1531         if (!Check(S, DecodeGPRRegisterClass(Inst, i, Address, Decoder)))
1532           return MCDisassembler::Fail;
1533         // Writeback not allowed if Rn is in the target list.
1534         if (NeedDisjointWriteback && WritebackReg == Inst.end()[-1].getReg())
1535           Check(S, MCDisassembler::SoftFail);
1536       }
1537     }
1538   }
1539 
1540   return S;
1541 }
1542 
1543 static DecodeStatus DecodeSPRRegListOperand(MCInst &Inst, unsigned Val,
1544                                  uint64_t Address, const void *Decoder) {
1545   DecodeStatus S = MCDisassembler::Success;
1546 
1547   unsigned Vd = fieldFromInstruction(Val, 8, 5);
1548   unsigned regs = fieldFromInstruction(Val, 0, 8);
1549 
1550   // In case of unpredictable encoding, tweak the operands.
1551   if (regs == 0 || (Vd + regs) > 32) {
1552     regs = Vd + regs > 32 ? 32 - Vd : regs;
1553     regs = std::max( 1u, regs);
1554     S = MCDisassembler::SoftFail;
1555   }
1556 
1557   if (!Check(S, DecodeSPRRegisterClass(Inst, Vd, Address, Decoder)))
1558     return MCDisassembler::Fail;
1559   for (unsigned i = 0; i < (regs - 1); ++i) {
1560     if (!Check(S, DecodeSPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1561       return MCDisassembler::Fail;
1562   }
1563 
1564   return S;
1565 }
1566 
1567 static DecodeStatus DecodeDPRRegListOperand(MCInst &Inst, unsigned Val,
1568                                  uint64_t Address, const void *Decoder) {
1569   DecodeStatus S = MCDisassembler::Success;
1570 
1571   unsigned Vd = fieldFromInstruction(Val, 8, 5);
1572   unsigned regs = fieldFromInstruction(Val, 1, 7);
1573 
1574   // In case of unpredictable encoding, tweak the operands.
1575   if (regs == 0 || regs > 16 || (Vd + regs) > 32) {
1576     regs = Vd + regs > 32 ? 32 - Vd : regs;
1577     regs = std::max( 1u, regs);
1578     regs = std::min(16u, regs);
1579     S = MCDisassembler::SoftFail;
1580   }
1581 
1582   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
1583       return MCDisassembler::Fail;
1584   for (unsigned i = 0; i < (regs - 1); ++i) {
1585     if (!Check(S, DecodeDPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1586       return MCDisassembler::Fail;
1587   }
1588 
1589   return S;
1590 }
1591 
1592 static DecodeStatus DecodeBitfieldMaskOperand(MCInst &Inst, unsigned Val,
1593                                       uint64_t Address, const void *Decoder) {
1594   // This operand encodes a mask of contiguous zeros between a specified MSB
1595   // and LSB.  To decode it, we create the mask of all bits MSB-and-lower,
1596   // the mask of all bits LSB-and-lower, and then xor them to create
1597   // the mask of that's all ones on [msb, lsb].  Finally we not it to
1598   // create the final mask.
1599   unsigned msb = fieldFromInstruction(Val, 5, 5);
1600   unsigned lsb = fieldFromInstruction(Val, 0, 5);
1601 
1602   DecodeStatus S = MCDisassembler::Success;
1603   if (lsb > msb) {
1604     Check(S, MCDisassembler::SoftFail);
1605     // The check above will cause the warning for the "potentially undefined
1606     // instruction encoding" but we can't build a bad MCOperand value here
1607     // with a lsb > msb or else printing the MCInst will cause a crash.
1608     lsb = msb;
1609   }
1610 
1611   uint32_t msb_mask = 0xFFFFFFFF;
1612   if (msb != 31) msb_mask = (1U << (msb+1)) - 1;
1613   uint32_t lsb_mask = (1U << lsb) - 1;
1614 
1615   Inst.addOperand(MCOperand::createImm(~(msb_mask ^ lsb_mask)));
1616   return S;
1617 }
1618 
1619 static DecodeStatus DecodeCopMemInstruction(MCInst &Inst, unsigned Insn,
1620                                   uint64_t Address, const void *Decoder) {
1621   DecodeStatus S = MCDisassembler::Success;
1622 
1623   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1624   unsigned CRd = fieldFromInstruction(Insn, 12, 4);
1625   unsigned coproc = fieldFromInstruction(Insn, 8, 4);
1626   unsigned imm = fieldFromInstruction(Insn, 0, 8);
1627   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1628   unsigned U = fieldFromInstruction(Insn, 23, 1);
1629   const FeatureBitset &featureBits =
1630     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1631 
1632   switch (Inst.getOpcode()) {
1633     case ARM::LDC_OFFSET:
1634     case ARM::LDC_PRE:
1635     case ARM::LDC_POST:
1636     case ARM::LDC_OPTION:
1637     case ARM::LDCL_OFFSET:
1638     case ARM::LDCL_PRE:
1639     case ARM::LDCL_POST:
1640     case ARM::LDCL_OPTION:
1641     case ARM::STC_OFFSET:
1642     case ARM::STC_PRE:
1643     case ARM::STC_POST:
1644     case ARM::STC_OPTION:
1645     case ARM::STCL_OFFSET:
1646     case ARM::STCL_PRE:
1647     case ARM::STCL_POST:
1648     case ARM::STCL_OPTION:
1649     case ARM::t2LDC_OFFSET:
1650     case ARM::t2LDC_PRE:
1651     case ARM::t2LDC_POST:
1652     case ARM::t2LDC_OPTION:
1653     case ARM::t2LDCL_OFFSET:
1654     case ARM::t2LDCL_PRE:
1655     case ARM::t2LDCL_POST:
1656     case ARM::t2LDCL_OPTION:
1657     case ARM::t2STC_OFFSET:
1658     case ARM::t2STC_PRE:
1659     case ARM::t2STC_POST:
1660     case ARM::t2STC_OPTION:
1661     case ARM::t2STCL_OFFSET:
1662     case ARM::t2STCL_PRE:
1663     case ARM::t2STCL_POST:
1664     case ARM::t2STCL_OPTION:
1665     case ARM::t2LDC2_OFFSET:
1666     case ARM::t2LDC2L_OFFSET:
1667     case ARM::t2LDC2_PRE:
1668     case ARM::t2LDC2L_PRE:
1669     case ARM::t2STC2_OFFSET:
1670     case ARM::t2STC2L_OFFSET:
1671     case ARM::t2STC2_PRE:
1672     case ARM::t2STC2L_PRE:
1673     case ARM::LDC2_OFFSET:
1674     case ARM::LDC2L_OFFSET:
1675     case ARM::LDC2_PRE:
1676     case ARM::LDC2L_PRE:
1677     case ARM::STC2_OFFSET:
1678     case ARM::STC2L_OFFSET:
1679     case ARM::STC2_PRE:
1680     case ARM::STC2L_PRE:
1681     case ARM::t2LDC2_OPTION:
1682     case ARM::t2STC2_OPTION:
1683     case ARM::t2LDC2_POST:
1684     case ARM::t2LDC2L_POST:
1685     case ARM::t2STC2_POST:
1686     case ARM::t2STC2L_POST:
1687     case ARM::LDC2_POST:
1688     case ARM::LDC2L_POST:
1689     case ARM::STC2_POST:
1690     case ARM::STC2L_POST:
1691       if (coproc == 0xA || coproc == 0xB ||
1692           (featureBits[ARM::HasV8_1MMainlineOps] &&
1693            (coproc == 0x8 || coproc == 0x9 || coproc == 0xA || coproc == 0xB ||
1694             coproc == 0xE || coproc == 0xF)))
1695         return MCDisassembler::Fail;
1696       break;
1697     default:
1698       break;
1699   }
1700 
1701   if (featureBits[ARM::HasV8Ops] && (coproc != 14))
1702     return MCDisassembler::Fail;
1703 
1704   Inst.addOperand(MCOperand::createImm(coproc));
1705   Inst.addOperand(MCOperand::createImm(CRd));
1706   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1707     return MCDisassembler::Fail;
1708 
1709   switch (Inst.getOpcode()) {
1710     case ARM::t2LDC2_OFFSET:
1711     case ARM::t2LDC2L_OFFSET:
1712     case ARM::t2LDC2_PRE:
1713     case ARM::t2LDC2L_PRE:
1714     case ARM::t2STC2_OFFSET:
1715     case ARM::t2STC2L_OFFSET:
1716     case ARM::t2STC2_PRE:
1717     case ARM::t2STC2L_PRE:
1718     case ARM::LDC2_OFFSET:
1719     case ARM::LDC2L_OFFSET:
1720     case ARM::LDC2_PRE:
1721     case ARM::LDC2L_PRE:
1722     case ARM::STC2_OFFSET:
1723     case ARM::STC2L_OFFSET:
1724     case ARM::STC2_PRE:
1725     case ARM::STC2L_PRE:
1726     case ARM::t2LDC_OFFSET:
1727     case ARM::t2LDCL_OFFSET:
1728     case ARM::t2LDC_PRE:
1729     case ARM::t2LDCL_PRE:
1730     case ARM::t2STC_OFFSET:
1731     case ARM::t2STCL_OFFSET:
1732     case ARM::t2STC_PRE:
1733     case ARM::t2STCL_PRE:
1734     case ARM::LDC_OFFSET:
1735     case ARM::LDCL_OFFSET:
1736     case ARM::LDC_PRE:
1737     case ARM::LDCL_PRE:
1738     case ARM::STC_OFFSET:
1739     case ARM::STCL_OFFSET:
1740     case ARM::STC_PRE:
1741     case ARM::STCL_PRE:
1742       imm = ARM_AM::getAM5Opc(U ? ARM_AM::add : ARM_AM::sub, imm);
1743       Inst.addOperand(MCOperand::createImm(imm));
1744       break;
1745     case ARM::t2LDC2_POST:
1746     case ARM::t2LDC2L_POST:
1747     case ARM::t2STC2_POST:
1748     case ARM::t2STC2L_POST:
1749     case ARM::LDC2_POST:
1750     case ARM::LDC2L_POST:
1751     case ARM::STC2_POST:
1752     case ARM::STC2L_POST:
1753     case ARM::t2LDC_POST:
1754     case ARM::t2LDCL_POST:
1755     case ARM::t2STC_POST:
1756     case ARM::t2STCL_POST:
1757     case ARM::LDC_POST:
1758     case ARM::LDCL_POST:
1759     case ARM::STC_POST:
1760     case ARM::STCL_POST:
1761       imm |= U << 8;
1762       LLVM_FALLTHROUGH;
1763     default:
1764       // The 'option' variant doesn't encode 'U' in the immediate since
1765       // the immediate is unsigned [0,255].
1766       Inst.addOperand(MCOperand::createImm(imm));
1767       break;
1768   }
1769 
1770   switch (Inst.getOpcode()) {
1771     case ARM::LDC_OFFSET:
1772     case ARM::LDC_PRE:
1773     case ARM::LDC_POST:
1774     case ARM::LDC_OPTION:
1775     case ARM::LDCL_OFFSET:
1776     case ARM::LDCL_PRE:
1777     case ARM::LDCL_POST:
1778     case ARM::LDCL_OPTION:
1779     case ARM::STC_OFFSET:
1780     case ARM::STC_PRE:
1781     case ARM::STC_POST:
1782     case ARM::STC_OPTION:
1783     case ARM::STCL_OFFSET:
1784     case ARM::STCL_PRE:
1785     case ARM::STCL_POST:
1786     case ARM::STCL_OPTION:
1787       if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1788         return MCDisassembler::Fail;
1789       break;
1790     default:
1791       break;
1792   }
1793 
1794   return S;
1795 }
1796 
1797 static DecodeStatus
1798 DecodeAddrMode2IdxInstruction(MCInst &Inst, unsigned Insn,
1799                               uint64_t Address, const void *Decoder) {
1800   DecodeStatus S = MCDisassembler::Success;
1801 
1802   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1803   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
1804   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
1805   unsigned imm = fieldFromInstruction(Insn, 0, 12);
1806   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1807   unsigned reg = fieldFromInstruction(Insn, 25, 1);
1808   unsigned P = fieldFromInstruction(Insn, 24, 1);
1809   unsigned W = fieldFromInstruction(Insn, 21, 1);
1810 
1811   // On stores, the writeback operand precedes Rt.
1812   switch (Inst.getOpcode()) {
1813     case ARM::STR_POST_IMM:
1814     case ARM::STR_POST_REG:
1815     case ARM::STRB_POST_IMM:
1816     case ARM::STRB_POST_REG:
1817     case ARM::STRT_POST_REG:
1818     case ARM::STRT_POST_IMM:
1819     case ARM::STRBT_POST_REG:
1820     case ARM::STRBT_POST_IMM:
1821       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1822         return MCDisassembler::Fail;
1823       break;
1824     default:
1825       break;
1826   }
1827 
1828   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
1829     return MCDisassembler::Fail;
1830 
1831   // On loads, the writeback operand comes after Rt.
1832   switch (Inst.getOpcode()) {
1833     case ARM::LDR_POST_IMM:
1834     case ARM::LDR_POST_REG:
1835     case ARM::LDRB_POST_IMM:
1836     case ARM::LDRB_POST_REG:
1837     case ARM::LDRBT_POST_REG:
1838     case ARM::LDRBT_POST_IMM:
1839     case ARM::LDRT_POST_REG:
1840     case ARM::LDRT_POST_IMM:
1841       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1842         return MCDisassembler::Fail;
1843       break;
1844     default:
1845       break;
1846   }
1847 
1848   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1849     return MCDisassembler::Fail;
1850 
1851   ARM_AM::AddrOpc Op = ARM_AM::add;
1852   if (!fieldFromInstruction(Insn, 23, 1))
1853     Op = ARM_AM::sub;
1854 
1855   bool writeback = (P == 0) || (W == 1);
1856   unsigned idx_mode = 0;
1857   if (P && writeback)
1858     idx_mode = ARMII::IndexModePre;
1859   else if (!P && writeback)
1860     idx_mode = ARMII::IndexModePost;
1861 
1862   if (writeback && (Rn == 15 || Rn == Rt))
1863     S = MCDisassembler::SoftFail; // UNPREDICTABLE
1864 
1865   if (reg) {
1866     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1867       return MCDisassembler::Fail;
1868     ARM_AM::ShiftOpc Opc = ARM_AM::lsl;
1869     switch( fieldFromInstruction(Insn, 5, 2)) {
1870       case 0:
1871         Opc = ARM_AM::lsl;
1872         break;
1873       case 1:
1874         Opc = ARM_AM::lsr;
1875         break;
1876       case 2:
1877         Opc = ARM_AM::asr;
1878         break;
1879       case 3:
1880         Opc = ARM_AM::ror;
1881         break;
1882       default:
1883         return MCDisassembler::Fail;
1884     }
1885     unsigned amt = fieldFromInstruction(Insn, 7, 5);
1886     if (Opc == ARM_AM::ror && amt == 0)
1887       Opc = ARM_AM::rrx;
1888     unsigned imm = ARM_AM::getAM2Opc(Op, amt, Opc, idx_mode);
1889 
1890     Inst.addOperand(MCOperand::createImm(imm));
1891   } else {
1892     Inst.addOperand(MCOperand::createReg(0));
1893     unsigned tmp = ARM_AM::getAM2Opc(Op, imm, ARM_AM::lsl, idx_mode);
1894     Inst.addOperand(MCOperand::createImm(tmp));
1895   }
1896 
1897   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1898     return MCDisassembler::Fail;
1899 
1900   return S;
1901 }
1902 
1903 static DecodeStatus DecodeSORegMemOperand(MCInst &Inst, unsigned Val,
1904                                   uint64_t Address, const void *Decoder) {
1905   DecodeStatus S = MCDisassembler::Success;
1906 
1907   unsigned Rn = fieldFromInstruction(Val, 13, 4);
1908   unsigned Rm = fieldFromInstruction(Val,  0, 4);
1909   unsigned type = fieldFromInstruction(Val, 5, 2);
1910   unsigned imm = fieldFromInstruction(Val, 7, 5);
1911   unsigned U = fieldFromInstruction(Val, 12, 1);
1912 
1913   ARM_AM::ShiftOpc ShOp = ARM_AM::lsl;
1914   switch (type) {
1915     case 0:
1916       ShOp = ARM_AM::lsl;
1917       break;
1918     case 1:
1919       ShOp = ARM_AM::lsr;
1920       break;
1921     case 2:
1922       ShOp = ARM_AM::asr;
1923       break;
1924     case 3:
1925       ShOp = ARM_AM::ror;
1926       break;
1927   }
1928 
1929   if (ShOp == ARM_AM::ror && imm == 0)
1930     ShOp = ARM_AM::rrx;
1931 
1932   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1933     return MCDisassembler::Fail;
1934   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1935     return MCDisassembler::Fail;
1936   unsigned shift;
1937   if (U)
1938     shift = ARM_AM::getAM2Opc(ARM_AM::add, imm, ShOp);
1939   else
1940     shift = ARM_AM::getAM2Opc(ARM_AM::sub, imm, ShOp);
1941   Inst.addOperand(MCOperand::createImm(shift));
1942 
1943   return S;
1944 }
1945 
1946 static DecodeStatus
1947 DecodeAddrMode3Instruction(MCInst &Inst, unsigned Insn,
1948                            uint64_t Address, const void *Decoder) {
1949   DecodeStatus S = MCDisassembler::Success;
1950 
1951   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
1952   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1953   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
1954   unsigned type = fieldFromInstruction(Insn, 22, 1);
1955   unsigned imm = fieldFromInstruction(Insn, 8, 4);
1956   unsigned U = ((~fieldFromInstruction(Insn, 23, 1)) & 1) << 8;
1957   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1958   unsigned W = fieldFromInstruction(Insn, 21, 1);
1959   unsigned P = fieldFromInstruction(Insn, 24, 1);
1960   unsigned Rt2 = Rt + 1;
1961 
1962   bool writeback = (W == 1) | (P == 0);
1963 
1964   // For {LD,ST}RD, Rt must be even, else undefined.
1965   switch (Inst.getOpcode()) {
1966     case ARM::STRD:
1967     case ARM::STRD_PRE:
1968     case ARM::STRD_POST:
1969     case ARM::LDRD:
1970     case ARM::LDRD_PRE:
1971     case ARM::LDRD_POST:
1972       if (Rt & 0x1) S = MCDisassembler::SoftFail;
1973       break;
1974     default:
1975       break;
1976   }
1977   switch (Inst.getOpcode()) {
1978     case ARM::STRD:
1979     case ARM::STRD_PRE:
1980     case ARM::STRD_POST:
1981       if (P == 0 && W == 1)
1982         S = MCDisassembler::SoftFail;
1983 
1984       if (writeback && (Rn == 15 || Rn == Rt || Rn == Rt2))
1985         S = MCDisassembler::SoftFail;
1986       if (type && Rm == 15)
1987         S = MCDisassembler::SoftFail;
1988       if (Rt2 == 15)
1989         S = MCDisassembler::SoftFail;
1990       if (!type && fieldFromInstruction(Insn, 8, 4))
1991         S = MCDisassembler::SoftFail;
1992       break;
1993     case ARM::STRH:
1994     case ARM::STRH_PRE:
1995     case ARM::STRH_POST:
1996       if (Rt == 15)
1997         S = MCDisassembler::SoftFail;
1998       if (writeback && (Rn == 15 || Rn == Rt))
1999         S = MCDisassembler::SoftFail;
2000       if (!type && Rm == 15)
2001         S = MCDisassembler::SoftFail;
2002       break;
2003     case ARM::LDRD:
2004     case ARM::LDRD_PRE:
2005     case ARM::LDRD_POST:
2006       if (type && Rn == 15) {
2007         if (Rt2 == 15)
2008           S = MCDisassembler::SoftFail;
2009         break;
2010       }
2011       if (P == 0 && W == 1)
2012         S = MCDisassembler::SoftFail;
2013       if (!type && (Rt2 == 15 || Rm == 15 || Rm == Rt || Rm == Rt2))
2014         S = MCDisassembler::SoftFail;
2015       if (!type && writeback && Rn == 15)
2016         S = MCDisassembler::SoftFail;
2017       if (writeback && (Rn == Rt || Rn == Rt2))
2018         S = MCDisassembler::SoftFail;
2019       break;
2020     case ARM::LDRH:
2021     case ARM::LDRH_PRE:
2022     case ARM::LDRH_POST:
2023       if (type && Rn == 15) {
2024         if (Rt == 15)
2025           S = MCDisassembler::SoftFail;
2026         break;
2027       }
2028       if (Rt == 15)
2029         S = MCDisassembler::SoftFail;
2030       if (!type && Rm == 15)
2031         S = MCDisassembler::SoftFail;
2032       if (!type && writeback && (Rn == 15 || Rn == Rt))
2033         S = MCDisassembler::SoftFail;
2034       break;
2035     case ARM::LDRSH:
2036     case ARM::LDRSH_PRE:
2037     case ARM::LDRSH_POST:
2038     case ARM::LDRSB:
2039     case ARM::LDRSB_PRE:
2040     case ARM::LDRSB_POST:
2041       if (type && Rn == 15) {
2042         if (Rt == 15)
2043           S = MCDisassembler::SoftFail;
2044         break;
2045       }
2046       if (type && (Rt == 15 || (writeback && Rn == Rt)))
2047         S = MCDisassembler::SoftFail;
2048       if (!type && (Rt == 15 || Rm == 15))
2049         S = MCDisassembler::SoftFail;
2050       if (!type && writeback && (Rn == 15 || Rn == Rt))
2051         S = MCDisassembler::SoftFail;
2052       break;
2053     default:
2054       break;
2055   }
2056 
2057   if (writeback) { // Writeback
2058     if (P)
2059       U |= ARMII::IndexModePre << 9;
2060     else
2061       U |= ARMII::IndexModePost << 9;
2062 
2063     // On stores, the writeback operand precedes Rt.
2064     switch (Inst.getOpcode()) {
2065     case ARM::STRD:
2066     case ARM::STRD_PRE:
2067     case ARM::STRD_POST:
2068     case ARM::STRH:
2069     case ARM::STRH_PRE:
2070     case ARM::STRH_POST:
2071       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2072         return MCDisassembler::Fail;
2073       break;
2074     default:
2075       break;
2076     }
2077   }
2078 
2079   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
2080     return MCDisassembler::Fail;
2081   switch (Inst.getOpcode()) {
2082     case ARM::STRD:
2083     case ARM::STRD_PRE:
2084     case ARM::STRD_POST:
2085     case ARM::LDRD:
2086     case ARM::LDRD_PRE:
2087     case ARM::LDRD_POST:
2088       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder)))
2089         return MCDisassembler::Fail;
2090       break;
2091     default:
2092       break;
2093   }
2094 
2095   if (writeback) {
2096     // On loads, the writeback operand comes after Rt.
2097     switch (Inst.getOpcode()) {
2098     case ARM::LDRD:
2099     case ARM::LDRD_PRE:
2100     case ARM::LDRD_POST:
2101     case ARM::LDRH:
2102     case ARM::LDRH_PRE:
2103     case ARM::LDRH_POST:
2104     case ARM::LDRSH:
2105     case ARM::LDRSH_PRE:
2106     case ARM::LDRSH_POST:
2107     case ARM::LDRSB:
2108     case ARM::LDRSB_PRE:
2109     case ARM::LDRSB_POST:
2110     case ARM::LDRHTr:
2111     case ARM::LDRSBTr:
2112       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2113         return MCDisassembler::Fail;
2114       break;
2115     default:
2116       break;
2117     }
2118   }
2119 
2120   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2121     return MCDisassembler::Fail;
2122 
2123   if (type) {
2124     Inst.addOperand(MCOperand::createReg(0));
2125     Inst.addOperand(MCOperand::createImm(U | (imm << 4) | Rm));
2126   } else {
2127     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2128     return MCDisassembler::Fail;
2129     Inst.addOperand(MCOperand::createImm(U));
2130   }
2131 
2132   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2133     return MCDisassembler::Fail;
2134 
2135   return S;
2136 }
2137 
2138 static DecodeStatus DecodeRFEInstruction(MCInst &Inst, unsigned Insn,
2139                                  uint64_t Address, const void *Decoder) {
2140   DecodeStatus S = MCDisassembler::Success;
2141 
2142   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2143   unsigned mode = fieldFromInstruction(Insn, 23, 2);
2144 
2145   switch (mode) {
2146     case 0:
2147       mode = ARM_AM::da;
2148       break;
2149     case 1:
2150       mode = ARM_AM::ia;
2151       break;
2152     case 2:
2153       mode = ARM_AM::db;
2154       break;
2155     case 3:
2156       mode = ARM_AM::ib;
2157       break;
2158   }
2159 
2160   Inst.addOperand(MCOperand::createImm(mode));
2161   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2162     return MCDisassembler::Fail;
2163 
2164   return S;
2165 }
2166 
2167 static DecodeStatus DecodeQADDInstruction(MCInst &Inst, unsigned Insn,
2168                                uint64_t Address, const void *Decoder) {
2169   DecodeStatus S = MCDisassembler::Success;
2170 
2171   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2172   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2173   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2174   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2175 
2176   if (pred == 0xF)
2177     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
2178 
2179   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2180     return MCDisassembler::Fail;
2181   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
2182     return MCDisassembler::Fail;
2183   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
2184     return MCDisassembler::Fail;
2185   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2186     return MCDisassembler::Fail;
2187   return S;
2188 }
2189 
2190 static DecodeStatus DecodeMemMultipleWritebackInstruction(MCInst &Inst,
2191                                   unsigned Insn,
2192                                   uint64_t Address, const void *Decoder) {
2193   DecodeStatus S = MCDisassembler::Success;
2194 
2195   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2196   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2197   unsigned reglist = fieldFromInstruction(Insn, 0, 16);
2198 
2199   if (pred == 0xF) {
2200     // Ambiguous with RFE and SRS
2201     switch (Inst.getOpcode()) {
2202       case ARM::LDMDA:
2203         Inst.setOpcode(ARM::RFEDA);
2204         break;
2205       case ARM::LDMDA_UPD:
2206         Inst.setOpcode(ARM::RFEDA_UPD);
2207         break;
2208       case ARM::LDMDB:
2209         Inst.setOpcode(ARM::RFEDB);
2210         break;
2211       case ARM::LDMDB_UPD:
2212         Inst.setOpcode(ARM::RFEDB_UPD);
2213         break;
2214       case ARM::LDMIA:
2215         Inst.setOpcode(ARM::RFEIA);
2216         break;
2217       case ARM::LDMIA_UPD:
2218         Inst.setOpcode(ARM::RFEIA_UPD);
2219         break;
2220       case ARM::LDMIB:
2221         Inst.setOpcode(ARM::RFEIB);
2222         break;
2223       case ARM::LDMIB_UPD:
2224         Inst.setOpcode(ARM::RFEIB_UPD);
2225         break;
2226       case ARM::STMDA:
2227         Inst.setOpcode(ARM::SRSDA);
2228         break;
2229       case ARM::STMDA_UPD:
2230         Inst.setOpcode(ARM::SRSDA_UPD);
2231         break;
2232       case ARM::STMDB:
2233         Inst.setOpcode(ARM::SRSDB);
2234         break;
2235       case ARM::STMDB_UPD:
2236         Inst.setOpcode(ARM::SRSDB_UPD);
2237         break;
2238       case ARM::STMIA:
2239         Inst.setOpcode(ARM::SRSIA);
2240         break;
2241       case ARM::STMIA_UPD:
2242         Inst.setOpcode(ARM::SRSIA_UPD);
2243         break;
2244       case ARM::STMIB:
2245         Inst.setOpcode(ARM::SRSIB);
2246         break;
2247       case ARM::STMIB_UPD:
2248         Inst.setOpcode(ARM::SRSIB_UPD);
2249         break;
2250       default:
2251         return MCDisassembler::Fail;
2252     }
2253 
2254     // For stores (which become SRS's, the only operand is the mode.
2255     if (fieldFromInstruction(Insn, 20, 1) == 0) {
2256       // Check SRS encoding constraints
2257       if (!(fieldFromInstruction(Insn, 22, 1) == 1 &&
2258             fieldFromInstruction(Insn, 20, 1) == 0))
2259         return MCDisassembler::Fail;
2260 
2261       Inst.addOperand(
2262           MCOperand::createImm(fieldFromInstruction(Insn, 0, 4)));
2263       return S;
2264     }
2265 
2266     return DecodeRFEInstruction(Inst, Insn, Address, Decoder);
2267   }
2268 
2269   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2270     return MCDisassembler::Fail;
2271   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2272     return MCDisassembler::Fail; // Tied
2273   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2274     return MCDisassembler::Fail;
2275   if (!Check(S, DecodeRegListOperand(Inst, reglist, Address, Decoder)))
2276     return MCDisassembler::Fail;
2277 
2278   return S;
2279 }
2280 
2281 // Check for UNPREDICTABLE predicated ESB instruction
2282 static DecodeStatus DecodeHINTInstruction(MCInst &Inst, unsigned Insn,
2283                                  uint64_t Address, const void *Decoder) {
2284   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2285   unsigned imm8 = fieldFromInstruction(Insn, 0, 8);
2286   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
2287   const FeatureBitset &FeatureBits = Dis->getSubtargetInfo().getFeatureBits();
2288 
2289   DecodeStatus S = MCDisassembler::Success;
2290 
2291   Inst.addOperand(MCOperand::createImm(imm8));
2292 
2293   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2294     return MCDisassembler::Fail;
2295 
2296   // ESB is unpredictable if pred != AL. Without the RAS extension, it is a NOP,
2297   // so all predicates should be allowed.
2298   if (imm8 == 0x10 && pred != 0xe && ((FeatureBits[ARM::FeatureRAS]) != 0))
2299     S = MCDisassembler::SoftFail;
2300 
2301   return S;
2302 }
2303 
2304 static DecodeStatus DecodeCPSInstruction(MCInst &Inst, unsigned Insn,
2305                                  uint64_t Address, const void *Decoder) {
2306   unsigned imod = fieldFromInstruction(Insn, 18, 2);
2307   unsigned M = fieldFromInstruction(Insn, 17, 1);
2308   unsigned iflags = fieldFromInstruction(Insn, 6, 3);
2309   unsigned mode = fieldFromInstruction(Insn, 0, 5);
2310 
2311   DecodeStatus S = MCDisassembler::Success;
2312 
2313   // This decoder is called from multiple location that do not check
2314   // the full encoding is valid before they do.
2315   if (fieldFromInstruction(Insn, 5, 1) != 0 ||
2316       fieldFromInstruction(Insn, 16, 1) != 0 ||
2317       fieldFromInstruction(Insn, 20, 8) != 0x10)
2318     return MCDisassembler::Fail;
2319 
2320   // imod == '01' --> UNPREDICTABLE
2321   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
2322   // return failure here.  The '01' imod value is unprintable, so there's
2323   // nothing useful we could do even if we returned UNPREDICTABLE.
2324 
2325   if (imod == 1) return MCDisassembler::Fail;
2326 
2327   if (imod && M) {
2328     Inst.setOpcode(ARM::CPS3p);
2329     Inst.addOperand(MCOperand::createImm(imod));
2330     Inst.addOperand(MCOperand::createImm(iflags));
2331     Inst.addOperand(MCOperand::createImm(mode));
2332   } else if (imod && !M) {
2333     Inst.setOpcode(ARM::CPS2p);
2334     Inst.addOperand(MCOperand::createImm(imod));
2335     Inst.addOperand(MCOperand::createImm(iflags));
2336     if (mode) S = MCDisassembler::SoftFail;
2337   } else if (!imod && M) {
2338     Inst.setOpcode(ARM::CPS1p);
2339     Inst.addOperand(MCOperand::createImm(mode));
2340     if (iflags) S = MCDisassembler::SoftFail;
2341   } else {
2342     // imod == '00' && M == '0' --> UNPREDICTABLE
2343     Inst.setOpcode(ARM::CPS1p);
2344     Inst.addOperand(MCOperand::createImm(mode));
2345     S = MCDisassembler::SoftFail;
2346   }
2347 
2348   return S;
2349 }
2350 
2351 static DecodeStatus DecodeT2CPSInstruction(MCInst &Inst, unsigned Insn,
2352                                  uint64_t Address, const void *Decoder) {
2353   unsigned imod = fieldFromInstruction(Insn, 9, 2);
2354   unsigned M = fieldFromInstruction(Insn, 8, 1);
2355   unsigned iflags = fieldFromInstruction(Insn, 5, 3);
2356   unsigned mode = fieldFromInstruction(Insn, 0, 5);
2357 
2358   DecodeStatus S = MCDisassembler::Success;
2359 
2360   // imod == '01' --> UNPREDICTABLE
2361   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
2362   // return failure here.  The '01' imod value is unprintable, so there's
2363   // nothing useful we could do even if we returned UNPREDICTABLE.
2364 
2365   if (imod == 1) return MCDisassembler::Fail;
2366 
2367   if (imod && M) {
2368     Inst.setOpcode(ARM::t2CPS3p);
2369     Inst.addOperand(MCOperand::createImm(imod));
2370     Inst.addOperand(MCOperand::createImm(iflags));
2371     Inst.addOperand(MCOperand::createImm(mode));
2372   } else if (imod && !M) {
2373     Inst.setOpcode(ARM::t2CPS2p);
2374     Inst.addOperand(MCOperand::createImm(imod));
2375     Inst.addOperand(MCOperand::createImm(iflags));
2376     if (mode) S = MCDisassembler::SoftFail;
2377   } else if (!imod && M) {
2378     Inst.setOpcode(ARM::t2CPS1p);
2379     Inst.addOperand(MCOperand::createImm(mode));
2380     if (iflags) S = MCDisassembler::SoftFail;
2381   } else {
2382     // imod == '00' && M == '0' --> this is a HINT instruction
2383     int imm = fieldFromInstruction(Insn, 0, 8);
2384     // HINT are defined only for immediate in [0..4]
2385     if(imm > 4) return MCDisassembler::Fail;
2386     Inst.setOpcode(ARM::t2HINT);
2387     Inst.addOperand(MCOperand::createImm(imm));
2388   }
2389 
2390   return S;
2391 }
2392 
2393 static DecodeStatus DecodeT2MOVTWInstruction(MCInst &Inst, unsigned Insn,
2394                                  uint64_t Address, const void *Decoder) {
2395   DecodeStatus S = MCDisassembler::Success;
2396 
2397   unsigned Rd = fieldFromInstruction(Insn, 8, 4);
2398   unsigned imm = 0;
2399 
2400   imm |= (fieldFromInstruction(Insn, 0, 8) << 0);
2401   imm |= (fieldFromInstruction(Insn, 12, 3) << 8);
2402   imm |= (fieldFromInstruction(Insn, 16, 4) << 12);
2403   imm |= (fieldFromInstruction(Insn, 26, 1) << 11);
2404 
2405   if (Inst.getOpcode() == ARM::t2MOVTi16)
2406     if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
2407       return MCDisassembler::Fail;
2408   if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
2409     return MCDisassembler::Fail;
2410 
2411   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
2412     Inst.addOperand(MCOperand::createImm(imm));
2413 
2414   return S;
2415 }
2416 
2417 static DecodeStatus DecodeArmMOVTWInstruction(MCInst &Inst, unsigned Insn,
2418                                  uint64_t Address, const void *Decoder) {
2419   DecodeStatus S = MCDisassembler::Success;
2420 
2421   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2422   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2423   unsigned imm = 0;
2424 
2425   imm |= (fieldFromInstruction(Insn, 0, 12) << 0);
2426   imm |= (fieldFromInstruction(Insn, 16, 4) << 12);
2427 
2428   if (Inst.getOpcode() == ARM::MOVTi16)
2429     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2430       return MCDisassembler::Fail;
2431 
2432   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2433     return MCDisassembler::Fail;
2434 
2435   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
2436     Inst.addOperand(MCOperand::createImm(imm));
2437 
2438   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2439     return MCDisassembler::Fail;
2440 
2441   return S;
2442 }
2443 
2444 static DecodeStatus DecodeSMLAInstruction(MCInst &Inst, unsigned Insn,
2445                                  uint64_t Address, const void *Decoder) {
2446   DecodeStatus S = MCDisassembler::Success;
2447 
2448   unsigned Rd = fieldFromInstruction(Insn, 16, 4);
2449   unsigned Rn = fieldFromInstruction(Insn, 0, 4);
2450   unsigned Rm = fieldFromInstruction(Insn, 8, 4);
2451   unsigned Ra = fieldFromInstruction(Insn, 12, 4);
2452   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2453 
2454   if (pred == 0xF)
2455     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
2456 
2457   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2458     return MCDisassembler::Fail;
2459   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
2460     return MCDisassembler::Fail;
2461   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
2462     return MCDisassembler::Fail;
2463   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Ra, Address, Decoder)))
2464     return MCDisassembler::Fail;
2465 
2466   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2467     return MCDisassembler::Fail;
2468 
2469   return S;
2470 }
2471 
2472 static DecodeStatus DecodeTSTInstruction(MCInst &Inst, unsigned Insn,
2473                                   uint64_t Address, const void *Decoder) {
2474   DecodeStatus S = MCDisassembler::Success;
2475 
2476   unsigned Pred = fieldFromInstruction(Insn, 28, 4);
2477   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2478   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2479 
2480   if (Pred == 0xF)
2481     return DecodeSETPANInstruction(Inst, Insn, Address, Decoder);
2482 
2483   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2484     return MCDisassembler::Fail;
2485   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2486     return MCDisassembler::Fail;
2487   if (!Check(S, DecodePredicateOperand(Inst, Pred, Address, Decoder)))
2488     return MCDisassembler::Fail;
2489 
2490   return S;
2491 }
2492 
2493 static DecodeStatus DecodeSETPANInstruction(MCInst &Inst, unsigned Insn,
2494                                   uint64_t Address, const void *Decoder) {
2495   DecodeStatus S = MCDisassembler::Success;
2496 
2497   unsigned Imm = fieldFromInstruction(Insn, 9, 1);
2498 
2499   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
2500   const FeatureBitset &FeatureBits = Dis->getSubtargetInfo().getFeatureBits();
2501 
2502   if (!FeatureBits[ARM::HasV8_1aOps] ||
2503       !FeatureBits[ARM::HasV8Ops])
2504     return MCDisassembler::Fail;
2505 
2506   // Decoder can be called from DecodeTST, which does not check the full
2507   // encoding is valid.
2508   if (fieldFromInstruction(Insn, 20,12) != 0xf11 ||
2509       fieldFromInstruction(Insn, 4,4) != 0)
2510     return MCDisassembler::Fail;
2511   if (fieldFromInstruction(Insn, 10,10) != 0 ||
2512       fieldFromInstruction(Insn, 0,4) != 0)
2513     S = MCDisassembler::SoftFail;
2514 
2515   Inst.setOpcode(ARM::SETPAN);
2516   Inst.addOperand(MCOperand::createImm(Imm));
2517 
2518   return S;
2519 }
2520 
2521 static DecodeStatus DecodeAddrModeImm12Operand(MCInst &Inst, unsigned Val,
2522                            uint64_t Address, const void *Decoder) {
2523   DecodeStatus S = MCDisassembler::Success;
2524 
2525   unsigned add = fieldFromInstruction(Val, 12, 1);
2526   unsigned imm = fieldFromInstruction(Val, 0, 12);
2527   unsigned Rn = fieldFromInstruction(Val, 13, 4);
2528 
2529   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2530     return MCDisassembler::Fail;
2531 
2532   if (!add) imm *= -1;
2533   if (imm == 0 && !add) imm = INT32_MIN;
2534   Inst.addOperand(MCOperand::createImm(imm));
2535   if (Rn == 15)
2536     tryAddingPcLoadReferenceComment(Address, Address + imm + 8, Decoder);
2537 
2538   return S;
2539 }
2540 
2541 static DecodeStatus DecodeAddrMode5Operand(MCInst &Inst, unsigned Val,
2542                                    uint64_t Address, const void *Decoder) {
2543   DecodeStatus S = MCDisassembler::Success;
2544 
2545   unsigned Rn = fieldFromInstruction(Val, 9, 4);
2546   // U == 1 to add imm, 0 to subtract it.
2547   unsigned U = fieldFromInstruction(Val, 8, 1);
2548   unsigned imm = fieldFromInstruction(Val, 0, 8);
2549 
2550   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2551     return MCDisassembler::Fail;
2552 
2553   if (U)
2554     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5Opc(ARM_AM::add, imm)));
2555   else
2556     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5Opc(ARM_AM::sub, imm)));
2557 
2558   return S;
2559 }
2560 
2561 static DecodeStatus DecodeAddrMode5FP16Operand(MCInst &Inst, unsigned Val,
2562                                    uint64_t Address, const void *Decoder) {
2563   DecodeStatus S = MCDisassembler::Success;
2564 
2565   unsigned Rn = fieldFromInstruction(Val, 9, 4);
2566   // U == 1 to add imm, 0 to subtract it.
2567   unsigned U = fieldFromInstruction(Val, 8, 1);
2568   unsigned imm = fieldFromInstruction(Val, 0, 8);
2569 
2570   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2571     return MCDisassembler::Fail;
2572 
2573   if (U)
2574     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5FP16Opc(ARM_AM::add, imm)));
2575   else
2576     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5FP16Opc(ARM_AM::sub, imm)));
2577 
2578   return S;
2579 }
2580 
2581 static DecodeStatus DecodeAddrMode7Operand(MCInst &Inst, unsigned Val,
2582                                    uint64_t Address, const void *Decoder) {
2583   return DecodeGPRRegisterClass(Inst, Val, Address, Decoder);
2584 }
2585 
2586 static DecodeStatus
2587 DecodeT2BInstruction(MCInst &Inst, unsigned Insn,
2588                      uint64_t Address, const void *Decoder) {
2589   DecodeStatus Status = MCDisassembler::Success;
2590 
2591   // Note the J1 and J2 values are from the encoded instruction.  So here
2592   // change them to I1 and I2 values via as documented:
2593   // I1 = NOT(J1 EOR S);
2594   // I2 = NOT(J2 EOR S);
2595   // and build the imm32 with one trailing zero as documented:
2596   // imm32 = SignExtend(S:I1:I2:imm10:imm11:'0', 32);
2597   unsigned S = fieldFromInstruction(Insn, 26, 1);
2598   unsigned J1 = fieldFromInstruction(Insn, 13, 1);
2599   unsigned J2 = fieldFromInstruction(Insn, 11, 1);
2600   unsigned I1 = !(J1 ^ S);
2601   unsigned I2 = !(J2 ^ S);
2602   unsigned imm10 = fieldFromInstruction(Insn, 16, 10);
2603   unsigned imm11 = fieldFromInstruction(Insn, 0, 11);
2604   unsigned tmp = (S << 23) | (I1 << 22) | (I2 << 21) | (imm10 << 11) | imm11;
2605   int imm32 = SignExtend32<25>(tmp << 1);
2606   if (!tryAddingSymbolicOperand(Address, Address + imm32 + 4,
2607                                 true, 4, Inst, Decoder))
2608     Inst.addOperand(MCOperand::createImm(imm32));
2609 
2610   return Status;
2611 }
2612 
2613 static DecodeStatus
2614 DecodeBranchImmInstruction(MCInst &Inst, unsigned Insn,
2615                            uint64_t Address, const void *Decoder) {
2616   DecodeStatus S = MCDisassembler::Success;
2617 
2618   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2619   unsigned imm = fieldFromInstruction(Insn, 0, 24) << 2;
2620 
2621   if (pred == 0xF) {
2622     Inst.setOpcode(ARM::BLXi);
2623     imm |= fieldFromInstruction(Insn, 24, 1) << 1;
2624     if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<26>(imm) + 8,
2625                                   true, 4, Inst, Decoder))
2626     Inst.addOperand(MCOperand::createImm(SignExtend32<26>(imm)));
2627     return S;
2628   }
2629 
2630   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<26>(imm) + 8,
2631                                 true, 4, Inst, Decoder))
2632     Inst.addOperand(MCOperand::createImm(SignExtend32<26>(imm)));
2633   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2634     return MCDisassembler::Fail;
2635 
2636   return S;
2637 }
2638 
2639 static DecodeStatus DecodeAddrMode6Operand(MCInst &Inst, unsigned Val,
2640                                    uint64_t Address, const void *Decoder) {
2641   DecodeStatus S = MCDisassembler::Success;
2642 
2643   unsigned Rm = fieldFromInstruction(Val, 0, 4);
2644   unsigned align = fieldFromInstruction(Val, 4, 2);
2645 
2646   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2647     return MCDisassembler::Fail;
2648   if (!align)
2649     Inst.addOperand(MCOperand::createImm(0));
2650   else
2651     Inst.addOperand(MCOperand::createImm(4 << align));
2652 
2653   return S;
2654 }
2655 
2656 static DecodeStatus DecodeVLDInstruction(MCInst &Inst, unsigned Insn,
2657                                    uint64_t Address, const void *Decoder) {
2658   DecodeStatus S = MCDisassembler::Success;
2659 
2660   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2661   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
2662   unsigned wb = fieldFromInstruction(Insn, 16, 4);
2663   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2664   Rn |= fieldFromInstruction(Insn, 4, 2) << 4;
2665   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2666 
2667   // First output register
2668   switch (Inst.getOpcode()) {
2669   case ARM::VLD1q16: case ARM::VLD1q32: case ARM::VLD1q64: case ARM::VLD1q8:
2670   case ARM::VLD1q16wb_fixed: case ARM::VLD1q16wb_register:
2671   case ARM::VLD1q32wb_fixed: case ARM::VLD1q32wb_register:
2672   case ARM::VLD1q64wb_fixed: case ARM::VLD1q64wb_register:
2673   case ARM::VLD1q8wb_fixed: case ARM::VLD1q8wb_register:
2674   case ARM::VLD2d16: case ARM::VLD2d32: case ARM::VLD2d8:
2675   case ARM::VLD2d16wb_fixed: case ARM::VLD2d16wb_register:
2676   case ARM::VLD2d32wb_fixed: case ARM::VLD2d32wb_register:
2677   case ARM::VLD2d8wb_fixed: case ARM::VLD2d8wb_register:
2678     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
2679       return MCDisassembler::Fail;
2680     break;
2681   case ARM::VLD2b16:
2682   case ARM::VLD2b32:
2683   case ARM::VLD2b8:
2684   case ARM::VLD2b16wb_fixed:
2685   case ARM::VLD2b16wb_register:
2686   case ARM::VLD2b32wb_fixed:
2687   case ARM::VLD2b32wb_register:
2688   case ARM::VLD2b8wb_fixed:
2689   case ARM::VLD2b8wb_register:
2690     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
2691       return MCDisassembler::Fail;
2692     break;
2693   default:
2694     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2695       return MCDisassembler::Fail;
2696   }
2697 
2698   // Second output register
2699   switch (Inst.getOpcode()) {
2700     case ARM::VLD3d8:
2701     case ARM::VLD3d16:
2702     case ARM::VLD3d32:
2703     case ARM::VLD3d8_UPD:
2704     case ARM::VLD3d16_UPD:
2705     case ARM::VLD3d32_UPD:
2706     case ARM::VLD4d8:
2707     case ARM::VLD4d16:
2708     case ARM::VLD4d32:
2709     case ARM::VLD4d8_UPD:
2710     case ARM::VLD4d16_UPD:
2711     case ARM::VLD4d32_UPD:
2712       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
2713         return MCDisassembler::Fail;
2714       break;
2715     case ARM::VLD3q8:
2716     case ARM::VLD3q16:
2717     case ARM::VLD3q32:
2718     case ARM::VLD3q8_UPD:
2719     case ARM::VLD3q16_UPD:
2720     case ARM::VLD3q32_UPD:
2721     case ARM::VLD4q8:
2722     case ARM::VLD4q16:
2723     case ARM::VLD4q32:
2724     case ARM::VLD4q8_UPD:
2725     case ARM::VLD4q16_UPD:
2726     case ARM::VLD4q32_UPD:
2727       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2728         return MCDisassembler::Fail;
2729       break;
2730     default:
2731       break;
2732   }
2733 
2734   // Third output register
2735   switch(Inst.getOpcode()) {
2736     case ARM::VLD3d8:
2737     case ARM::VLD3d16:
2738     case ARM::VLD3d32:
2739     case ARM::VLD3d8_UPD:
2740     case ARM::VLD3d16_UPD:
2741     case ARM::VLD3d32_UPD:
2742     case ARM::VLD4d8:
2743     case ARM::VLD4d16:
2744     case ARM::VLD4d32:
2745     case ARM::VLD4d8_UPD:
2746     case ARM::VLD4d16_UPD:
2747     case ARM::VLD4d32_UPD:
2748       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2749         return MCDisassembler::Fail;
2750       break;
2751     case ARM::VLD3q8:
2752     case ARM::VLD3q16:
2753     case ARM::VLD3q32:
2754     case ARM::VLD3q8_UPD:
2755     case ARM::VLD3q16_UPD:
2756     case ARM::VLD3q32_UPD:
2757     case ARM::VLD4q8:
2758     case ARM::VLD4q16:
2759     case ARM::VLD4q32:
2760     case ARM::VLD4q8_UPD:
2761     case ARM::VLD4q16_UPD:
2762     case ARM::VLD4q32_UPD:
2763       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
2764         return MCDisassembler::Fail;
2765       break;
2766     default:
2767       break;
2768   }
2769 
2770   // Fourth output register
2771   switch (Inst.getOpcode()) {
2772     case ARM::VLD4d8:
2773     case ARM::VLD4d16:
2774     case ARM::VLD4d32:
2775     case ARM::VLD4d8_UPD:
2776     case ARM::VLD4d16_UPD:
2777     case ARM::VLD4d32_UPD:
2778       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
2779         return MCDisassembler::Fail;
2780       break;
2781     case ARM::VLD4q8:
2782     case ARM::VLD4q16:
2783     case ARM::VLD4q32:
2784     case ARM::VLD4q8_UPD:
2785     case ARM::VLD4q16_UPD:
2786     case ARM::VLD4q32_UPD:
2787       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
2788         return MCDisassembler::Fail;
2789       break;
2790     default:
2791       break;
2792   }
2793 
2794   // Writeback operand
2795   switch (Inst.getOpcode()) {
2796     case ARM::VLD1d8wb_fixed:
2797     case ARM::VLD1d16wb_fixed:
2798     case ARM::VLD1d32wb_fixed:
2799     case ARM::VLD1d64wb_fixed:
2800     case ARM::VLD1d8wb_register:
2801     case ARM::VLD1d16wb_register:
2802     case ARM::VLD1d32wb_register:
2803     case ARM::VLD1d64wb_register:
2804     case ARM::VLD1q8wb_fixed:
2805     case ARM::VLD1q16wb_fixed:
2806     case ARM::VLD1q32wb_fixed:
2807     case ARM::VLD1q64wb_fixed:
2808     case ARM::VLD1q8wb_register:
2809     case ARM::VLD1q16wb_register:
2810     case ARM::VLD1q32wb_register:
2811     case ARM::VLD1q64wb_register:
2812     case ARM::VLD1d8Twb_fixed:
2813     case ARM::VLD1d8Twb_register:
2814     case ARM::VLD1d16Twb_fixed:
2815     case ARM::VLD1d16Twb_register:
2816     case ARM::VLD1d32Twb_fixed:
2817     case ARM::VLD1d32Twb_register:
2818     case ARM::VLD1d64Twb_fixed:
2819     case ARM::VLD1d64Twb_register:
2820     case ARM::VLD1d8Qwb_fixed:
2821     case ARM::VLD1d8Qwb_register:
2822     case ARM::VLD1d16Qwb_fixed:
2823     case ARM::VLD1d16Qwb_register:
2824     case ARM::VLD1d32Qwb_fixed:
2825     case ARM::VLD1d32Qwb_register:
2826     case ARM::VLD1d64Qwb_fixed:
2827     case ARM::VLD1d64Qwb_register:
2828     case ARM::VLD2d8wb_fixed:
2829     case ARM::VLD2d16wb_fixed:
2830     case ARM::VLD2d32wb_fixed:
2831     case ARM::VLD2q8wb_fixed:
2832     case ARM::VLD2q16wb_fixed:
2833     case ARM::VLD2q32wb_fixed:
2834     case ARM::VLD2d8wb_register:
2835     case ARM::VLD2d16wb_register:
2836     case ARM::VLD2d32wb_register:
2837     case ARM::VLD2q8wb_register:
2838     case ARM::VLD2q16wb_register:
2839     case ARM::VLD2q32wb_register:
2840     case ARM::VLD2b8wb_fixed:
2841     case ARM::VLD2b16wb_fixed:
2842     case ARM::VLD2b32wb_fixed:
2843     case ARM::VLD2b8wb_register:
2844     case ARM::VLD2b16wb_register:
2845     case ARM::VLD2b32wb_register:
2846       Inst.addOperand(MCOperand::createImm(0));
2847       break;
2848     case ARM::VLD3d8_UPD:
2849     case ARM::VLD3d16_UPD:
2850     case ARM::VLD3d32_UPD:
2851     case ARM::VLD3q8_UPD:
2852     case ARM::VLD3q16_UPD:
2853     case ARM::VLD3q32_UPD:
2854     case ARM::VLD4d8_UPD:
2855     case ARM::VLD4d16_UPD:
2856     case ARM::VLD4d32_UPD:
2857     case ARM::VLD4q8_UPD:
2858     case ARM::VLD4q16_UPD:
2859     case ARM::VLD4q32_UPD:
2860       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
2861         return MCDisassembler::Fail;
2862       break;
2863     default:
2864       break;
2865   }
2866 
2867   // AddrMode6 Base (register+alignment)
2868   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
2869     return MCDisassembler::Fail;
2870 
2871   // AddrMode6 Offset (register)
2872   switch (Inst.getOpcode()) {
2873   default:
2874     // The below have been updated to have explicit am6offset split
2875     // between fixed and register offset. For those instructions not
2876     // yet updated, we need to add an additional reg0 operand for the
2877     // fixed variant.
2878     //
2879     // The fixed offset encodes as Rm == 0xd, so we check for that.
2880     if (Rm == 0xd) {
2881       Inst.addOperand(MCOperand::createReg(0));
2882       break;
2883     }
2884     // Fall through to handle the register offset variant.
2885     LLVM_FALLTHROUGH;
2886   case ARM::VLD1d8wb_fixed:
2887   case ARM::VLD1d16wb_fixed:
2888   case ARM::VLD1d32wb_fixed:
2889   case ARM::VLD1d64wb_fixed:
2890   case ARM::VLD1d8Twb_fixed:
2891   case ARM::VLD1d16Twb_fixed:
2892   case ARM::VLD1d32Twb_fixed:
2893   case ARM::VLD1d64Twb_fixed:
2894   case ARM::VLD1d8Qwb_fixed:
2895   case ARM::VLD1d16Qwb_fixed:
2896   case ARM::VLD1d32Qwb_fixed:
2897   case ARM::VLD1d64Qwb_fixed:
2898   case ARM::VLD1d8wb_register:
2899   case ARM::VLD1d16wb_register:
2900   case ARM::VLD1d32wb_register:
2901   case ARM::VLD1d64wb_register:
2902   case ARM::VLD1q8wb_fixed:
2903   case ARM::VLD1q16wb_fixed:
2904   case ARM::VLD1q32wb_fixed:
2905   case ARM::VLD1q64wb_fixed:
2906   case ARM::VLD1q8wb_register:
2907   case ARM::VLD1q16wb_register:
2908   case ARM::VLD1q32wb_register:
2909   case ARM::VLD1q64wb_register:
2910     // The fixed offset post-increment encodes Rm == 0xd. The no-writeback
2911     // variant encodes Rm == 0xf. Anything else is a register offset post-
2912     // increment and we need to add the register operand to the instruction.
2913     if (Rm != 0xD && Rm != 0xF &&
2914         !Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2915       return MCDisassembler::Fail;
2916     break;
2917   case ARM::VLD2d8wb_fixed:
2918   case ARM::VLD2d16wb_fixed:
2919   case ARM::VLD2d32wb_fixed:
2920   case ARM::VLD2b8wb_fixed:
2921   case ARM::VLD2b16wb_fixed:
2922   case ARM::VLD2b32wb_fixed:
2923   case ARM::VLD2q8wb_fixed:
2924   case ARM::VLD2q16wb_fixed:
2925   case ARM::VLD2q32wb_fixed:
2926     break;
2927   }
2928 
2929   return S;
2930 }
2931 
2932 static DecodeStatus DecodeVLDST1Instruction(MCInst &Inst, unsigned Insn,
2933                                    uint64_t Address, const void *Decoder) {
2934   unsigned type = fieldFromInstruction(Insn, 8, 4);
2935   unsigned align = fieldFromInstruction(Insn, 4, 2);
2936   if (type == 6 && (align & 2)) return MCDisassembler::Fail;
2937   if (type == 7 && (align & 2)) return MCDisassembler::Fail;
2938   if (type == 10 && align == 3) return MCDisassembler::Fail;
2939 
2940   unsigned load = fieldFromInstruction(Insn, 21, 1);
2941   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2942               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2943 }
2944 
2945 static DecodeStatus DecodeVLDST2Instruction(MCInst &Inst, unsigned Insn,
2946                                    uint64_t Address, const void *Decoder) {
2947   unsigned size = fieldFromInstruction(Insn, 6, 2);
2948   if (size == 3) return MCDisassembler::Fail;
2949 
2950   unsigned type = fieldFromInstruction(Insn, 8, 4);
2951   unsigned align = fieldFromInstruction(Insn, 4, 2);
2952   if (type == 8 && align == 3) return MCDisassembler::Fail;
2953   if (type == 9 && align == 3) return MCDisassembler::Fail;
2954 
2955   unsigned load = fieldFromInstruction(Insn, 21, 1);
2956   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2957               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2958 }
2959 
2960 static DecodeStatus DecodeVLDST3Instruction(MCInst &Inst, unsigned Insn,
2961                                    uint64_t Address, const void *Decoder) {
2962   unsigned size = fieldFromInstruction(Insn, 6, 2);
2963   if (size == 3) return MCDisassembler::Fail;
2964 
2965   unsigned align = fieldFromInstruction(Insn, 4, 2);
2966   if (align & 2) return MCDisassembler::Fail;
2967 
2968   unsigned load = fieldFromInstruction(Insn, 21, 1);
2969   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2970               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2971 }
2972 
2973 static DecodeStatus DecodeVLDST4Instruction(MCInst &Inst, unsigned Insn,
2974                                    uint64_t Address, const void *Decoder) {
2975   unsigned size = fieldFromInstruction(Insn, 6, 2);
2976   if (size == 3) return MCDisassembler::Fail;
2977 
2978   unsigned load = fieldFromInstruction(Insn, 21, 1);
2979   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2980               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2981 }
2982 
2983 static DecodeStatus DecodeVSTInstruction(MCInst &Inst, unsigned Insn,
2984                                  uint64_t Address, const void *Decoder) {
2985   DecodeStatus S = MCDisassembler::Success;
2986 
2987   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2988   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
2989   unsigned wb = fieldFromInstruction(Insn, 16, 4);
2990   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2991   Rn |= fieldFromInstruction(Insn, 4, 2) << 4;
2992   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2993 
2994   // Writeback Operand
2995   switch (Inst.getOpcode()) {
2996     case ARM::VST1d8wb_fixed:
2997     case ARM::VST1d16wb_fixed:
2998     case ARM::VST1d32wb_fixed:
2999     case ARM::VST1d64wb_fixed:
3000     case ARM::VST1d8wb_register:
3001     case ARM::VST1d16wb_register:
3002     case ARM::VST1d32wb_register:
3003     case ARM::VST1d64wb_register:
3004     case ARM::VST1q8wb_fixed:
3005     case ARM::VST1q16wb_fixed:
3006     case ARM::VST1q32wb_fixed:
3007     case ARM::VST1q64wb_fixed:
3008     case ARM::VST1q8wb_register:
3009     case ARM::VST1q16wb_register:
3010     case ARM::VST1q32wb_register:
3011     case ARM::VST1q64wb_register:
3012     case ARM::VST1d8Twb_fixed:
3013     case ARM::VST1d16Twb_fixed:
3014     case ARM::VST1d32Twb_fixed:
3015     case ARM::VST1d64Twb_fixed:
3016     case ARM::VST1d8Twb_register:
3017     case ARM::VST1d16Twb_register:
3018     case ARM::VST1d32Twb_register:
3019     case ARM::VST1d64Twb_register:
3020     case ARM::VST1d8Qwb_fixed:
3021     case ARM::VST1d16Qwb_fixed:
3022     case ARM::VST1d32Qwb_fixed:
3023     case ARM::VST1d64Qwb_fixed:
3024     case ARM::VST1d8Qwb_register:
3025     case ARM::VST1d16Qwb_register:
3026     case ARM::VST1d32Qwb_register:
3027     case ARM::VST1d64Qwb_register:
3028     case ARM::VST2d8wb_fixed:
3029     case ARM::VST2d16wb_fixed:
3030     case ARM::VST2d32wb_fixed:
3031     case ARM::VST2d8wb_register:
3032     case ARM::VST2d16wb_register:
3033     case ARM::VST2d32wb_register:
3034     case ARM::VST2q8wb_fixed:
3035     case ARM::VST2q16wb_fixed:
3036     case ARM::VST2q32wb_fixed:
3037     case ARM::VST2q8wb_register:
3038     case ARM::VST2q16wb_register:
3039     case ARM::VST2q32wb_register:
3040     case ARM::VST2b8wb_fixed:
3041     case ARM::VST2b16wb_fixed:
3042     case ARM::VST2b32wb_fixed:
3043     case ARM::VST2b8wb_register:
3044     case ARM::VST2b16wb_register:
3045     case ARM::VST2b32wb_register:
3046       if (Rm == 0xF)
3047         return MCDisassembler::Fail;
3048       Inst.addOperand(MCOperand::createImm(0));
3049       break;
3050     case ARM::VST3d8_UPD:
3051     case ARM::VST3d16_UPD:
3052     case ARM::VST3d32_UPD:
3053     case ARM::VST3q8_UPD:
3054     case ARM::VST3q16_UPD:
3055     case ARM::VST3q32_UPD:
3056     case ARM::VST4d8_UPD:
3057     case ARM::VST4d16_UPD:
3058     case ARM::VST4d32_UPD:
3059     case ARM::VST4q8_UPD:
3060     case ARM::VST4q16_UPD:
3061     case ARM::VST4q32_UPD:
3062       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
3063         return MCDisassembler::Fail;
3064       break;
3065     default:
3066       break;
3067   }
3068 
3069   // AddrMode6 Base (register+alignment)
3070   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
3071     return MCDisassembler::Fail;
3072 
3073   // AddrMode6 Offset (register)
3074   switch (Inst.getOpcode()) {
3075     default:
3076       if (Rm == 0xD)
3077         Inst.addOperand(MCOperand::createReg(0));
3078       else if (Rm != 0xF) {
3079         if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3080           return MCDisassembler::Fail;
3081       }
3082       break;
3083     case ARM::VST1d8wb_fixed:
3084     case ARM::VST1d16wb_fixed:
3085     case ARM::VST1d32wb_fixed:
3086     case ARM::VST1d64wb_fixed:
3087     case ARM::VST1q8wb_fixed:
3088     case ARM::VST1q16wb_fixed:
3089     case ARM::VST1q32wb_fixed:
3090     case ARM::VST1q64wb_fixed:
3091     case ARM::VST1d8Twb_fixed:
3092     case ARM::VST1d16Twb_fixed:
3093     case ARM::VST1d32Twb_fixed:
3094     case ARM::VST1d64Twb_fixed:
3095     case ARM::VST1d8Qwb_fixed:
3096     case ARM::VST1d16Qwb_fixed:
3097     case ARM::VST1d32Qwb_fixed:
3098     case ARM::VST1d64Qwb_fixed:
3099     case ARM::VST2d8wb_fixed:
3100     case ARM::VST2d16wb_fixed:
3101     case ARM::VST2d32wb_fixed:
3102     case ARM::VST2q8wb_fixed:
3103     case ARM::VST2q16wb_fixed:
3104     case ARM::VST2q32wb_fixed:
3105     case ARM::VST2b8wb_fixed:
3106     case ARM::VST2b16wb_fixed:
3107     case ARM::VST2b32wb_fixed:
3108       break;
3109   }
3110 
3111   // First input register
3112   switch (Inst.getOpcode()) {
3113   case ARM::VST1q16:
3114   case ARM::VST1q32:
3115   case ARM::VST1q64:
3116   case ARM::VST1q8:
3117   case ARM::VST1q16wb_fixed:
3118   case ARM::VST1q16wb_register:
3119   case ARM::VST1q32wb_fixed:
3120   case ARM::VST1q32wb_register:
3121   case ARM::VST1q64wb_fixed:
3122   case ARM::VST1q64wb_register:
3123   case ARM::VST1q8wb_fixed:
3124   case ARM::VST1q8wb_register:
3125   case ARM::VST2d16:
3126   case ARM::VST2d32:
3127   case ARM::VST2d8:
3128   case ARM::VST2d16wb_fixed:
3129   case ARM::VST2d16wb_register:
3130   case ARM::VST2d32wb_fixed:
3131   case ARM::VST2d32wb_register:
3132   case ARM::VST2d8wb_fixed:
3133   case ARM::VST2d8wb_register:
3134     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3135       return MCDisassembler::Fail;
3136     break;
3137   case ARM::VST2b16:
3138   case ARM::VST2b32:
3139   case ARM::VST2b8:
3140   case ARM::VST2b16wb_fixed:
3141   case ARM::VST2b16wb_register:
3142   case ARM::VST2b32wb_fixed:
3143   case ARM::VST2b32wb_register:
3144   case ARM::VST2b8wb_fixed:
3145   case ARM::VST2b8wb_register:
3146     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
3147       return MCDisassembler::Fail;
3148     break;
3149   default:
3150     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3151       return MCDisassembler::Fail;
3152   }
3153 
3154   // Second input register
3155   switch (Inst.getOpcode()) {
3156     case ARM::VST3d8:
3157     case ARM::VST3d16:
3158     case ARM::VST3d32:
3159     case ARM::VST3d8_UPD:
3160     case ARM::VST3d16_UPD:
3161     case ARM::VST3d32_UPD:
3162     case ARM::VST4d8:
3163     case ARM::VST4d16:
3164     case ARM::VST4d32:
3165     case ARM::VST4d8_UPD:
3166     case ARM::VST4d16_UPD:
3167     case ARM::VST4d32_UPD:
3168       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
3169         return MCDisassembler::Fail;
3170       break;
3171     case ARM::VST3q8:
3172     case ARM::VST3q16:
3173     case ARM::VST3q32:
3174     case ARM::VST3q8_UPD:
3175     case ARM::VST3q16_UPD:
3176     case ARM::VST3q32_UPD:
3177     case ARM::VST4q8:
3178     case ARM::VST4q16:
3179     case ARM::VST4q32:
3180     case ARM::VST4q8_UPD:
3181     case ARM::VST4q16_UPD:
3182     case ARM::VST4q32_UPD:
3183       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
3184         return MCDisassembler::Fail;
3185       break;
3186     default:
3187       break;
3188   }
3189 
3190   // Third input register
3191   switch (Inst.getOpcode()) {
3192     case ARM::VST3d8:
3193     case ARM::VST3d16:
3194     case ARM::VST3d32:
3195     case ARM::VST3d8_UPD:
3196     case ARM::VST3d16_UPD:
3197     case ARM::VST3d32_UPD:
3198     case ARM::VST4d8:
3199     case ARM::VST4d16:
3200     case ARM::VST4d32:
3201     case ARM::VST4d8_UPD:
3202     case ARM::VST4d16_UPD:
3203     case ARM::VST4d32_UPD:
3204       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
3205         return MCDisassembler::Fail;
3206       break;
3207     case ARM::VST3q8:
3208     case ARM::VST3q16:
3209     case ARM::VST3q32:
3210     case ARM::VST3q8_UPD:
3211     case ARM::VST3q16_UPD:
3212     case ARM::VST3q32_UPD:
3213     case ARM::VST4q8:
3214     case ARM::VST4q16:
3215     case ARM::VST4q32:
3216     case ARM::VST4q8_UPD:
3217     case ARM::VST4q16_UPD:
3218     case ARM::VST4q32_UPD:
3219       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
3220         return MCDisassembler::Fail;
3221       break;
3222     default:
3223       break;
3224   }
3225 
3226   // Fourth input register
3227   switch (Inst.getOpcode()) {
3228     case ARM::VST4d8:
3229     case ARM::VST4d16:
3230     case ARM::VST4d32:
3231     case ARM::VST4d8_UPD:
3232     case ARM::VST4d16_UPD:
3233     case ARM::VST4d32_UPD:
3234       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
3235         return MCDisassembler::Fail;
3236       break;
3237     case ARM::VST4q8:
3238     case ARM::VST4q16:
3239     case ARM::VST4q32:
3240     case ARM::VST4q8_UPD:
3241     case ARM::VST4q16_UPD:
3242     case ARM::VST4q32_UPD:
3243       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
3244         return MCDisassembler::Fail;
3245       break;
3246     default:
3247       break;
3248   }
3249 
3250   return S;
3251 }
3252 
3253 static DecodeStatus DecodeVLD1DupInstruction(MCInst &Inst, unsigned Insn,
3254                                     uint64_t Address, const void *Decoder) {
3255   DecodeStatus S = MCDisassembler::Success;
3256 
3257   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3258   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3259   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3260   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3261   unsigned align = fieldFromInstruction(Insn, 4, 1);
3262   unsigned size = fieldFromInstruction(Insn, 6, 2);
3263 
3264   if (size == 0 && align == 1)
3265     return MCDisassembler::Fail;
3266   align *= (1 << size);
3267 
3268   switch (Inst.getOpcode()) {
3269   case ARM::VLD1DUPq16: case ARM::VLD1DUPq32: case ARM::VLD1DUPq8:
3270   case ARM::VLD1DUPq16wb_fixed: case ARM::VLD1DUPq16wb_register:
3271   case ARM::VLD1DUPq32wb_fixed: case ARM::VLD1DUPq32wb_register:
3272   case ARM::VLD1DUPq8wb_fixed: case ARM::VLD1DUPq8wb_register:
3273     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3274       return MCDisassembler::Fail;
3275     break;
3276   default:
3277     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3278       return MCDisassembler::Fail;
3279     break;
3280   }
3281   if (Rm != 0xF) {
3282     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3283       return MCDisassembler::Fail;
3284   }
3285 
3286   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3287     return MCDisassembler::Fail;
3288   Inst.addOperand(MCOperand::createImm(align));
3289 
3290   // The fixed offset post-increment encodes Rm == 0xd. The no-writeback
3291   // variant encodes Rm == 0xf. Anything else is a register offset post-
3292   // increment and we need to add the register operand to the instruction.
3293   if (Rm != 0xD && Rm != 0xF &&
3294       !Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3295     return MCDisassembler::Fail;
3296 
3297   return S;
3298 }
3299 
3300 static DecodeStatus DecodeVLD2DupInstruction(MCInst &Inst, unsigned Insn,
3301                                     uint64_t Address, const void *Decoder) {
3302   DecodeStatus S = MCDisassembler::Success;
3303 
3304   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3305   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3306   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3307   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3308   unsigned align = fieldFromInstruction(Insn, 4, 1);
3309   unsigned size = 1 << fieldFromInstruction(Insn, 6, 2);
3310   align *= 2*size;
3311 
3312   switch (Inst.getOpcode()) {
3313   case ARM::VLD2DUPd16: case ARM::VLD2DUPd32: case ARM::VLD2DUPd8:
3314   case ARM::VLD2DUPd16wb_fixed: case ARM::VLD2DUPd16wb_register:
3315   case ARM::VLD2DUPd32wb_fixed: case ARM::VLD2DUPd32wb_register:
3316   case ARM::VLD2DUPd8wb_fixed: case ARM::VLD2DUPd8wb_register:
3317     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3318       return MCDisassembler::Fail;
3319     break;
3320   case ARM::VLD2DUPd16x2: case ARM::VLD2DUPd32x2: case ARM::VLD2DUPd8x2:
3321   case ARM::VLD2DUPd16x2wb_fixed: case ARM::VLD2DUPd16x2wb_register:
3322   case ARM::VLD2DUPd32x2wb_fixed: case ARM::VLD2DUPd32x2wb_register:
3323   case ARM::VLD2DUPd8x2wb_fixed: case ARM::VLD2DUPd8x2wb_register:
3324     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
3325       return MCDisassembler::Fail;
3326     break;
3327   default:
3328     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3329       return MCDisassembler::Fail;
3330     break;
3331   }
3332 
3333   if (Rm != 0xF)
3334     Inst.addOperand(MCOperand::createImm(0));
3335 
3336   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3337     return MCDisassembler::Fail;
3338   Inst.addOperand(MCOperand::createImm(align));
3339 
3340   if (Rm != 0xD && Rm != 0xF) {
3341     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3342       return MCDisassembler::Fail;
3343   }
3344 
3345   return S;
3346 }
3347 
3348 static DecodeStatus DecodeVLD3DupInstruction(MCInst &Inst, unsigned Insn,
3349                                     uint64_t Address, const void *Decoder) {
3350   DecodeStatus S = MCDisassembler::Success;
3351 
3352   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3353   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3354   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3355   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3356   unsigned inc = fieldFromInstruction(Insn, 5, 1) + 1;
3357 
3358   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3359     return MCDisassembler::Fail;
3360   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
3361     return MCDisassembler::Fail;
3362   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
3363     return MCDisassembler::Fail;
3364   if (Rm != 0xF) {
3365     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3366       return MCDisassembler::Fail;
3367   }
3368 
3369   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3370     return MCDisassembler::Fail;
3371   Inst.addOperand(MCOperand::createImm(0));
3372 
3373   if (Rm == 0xD)
3374     Inst.addOperand(MCOperand::createReg(0));
3375   else if (Rm != 0xF) {
3376     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3377       return MCDisassembler::Fail;
3378   }
3379 
3380   return S;
3381 }
3382 
3383 static DecodeStatus DecodeVLD4DupInstruction(MCInst &Inst, unsigned Insn,
3384                                     uint64_t Address, const void *Decoder) {
3385   DecodeStatus S = MCDisassembler::Success;
3386 
3387   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3388   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3389   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3390   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3391   unsigned size = fieldFromInstruction(Insn, 6, 2);
3392   unsigned inc = fieldFromInstruction(Insn, 5, 1) + 1;
3393   unsigned align = fieldFromInstruction(Insn, 4, 1);
3394 
3395   if (size == 0x3) {
3396     if (align == 0)
3397       return MCDisassembler::Fail;
3398     align = 16;
3399   } else {
3400     if (size == 2) {
3401       align *= 8;
3402     } else {
3403       size = 1 << size;
3404       align *= 4*size;
3405     }
3406   }
3407 
3408   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3409     return MCDisassembler::Fail;
3410   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
3411     return MCDisassembler::Fail;
3412   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
3413     return MCDisassembler::Fail;
3414   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3*inc)%32, Address, Decoder)))
3415     return MCDisassembler::Fail;
3416   if (Rm != 0xF) {
3417     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3418       return MCDisassembler::Fail;
3419   }
3420 
3421   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3422     return MCDisassembler::Fail;
3423   Inst.addOperand(MCOperand::createImm(align));
3424 
3425   if (Rm == 0xD)
3426     Inst.addOperand(MCOperand::createReg(0));
3427   else if (Rm != 0xF) {
3428     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3429       return MCDisassembler::Fail;
3430   }
3431 
3432   return S;
3433 }
3434 
3435 static DecodeStatus
3436 DecodeNEONModImmInstruction(MCInst &Inst, unsigned Insn,
3437                             uint64_t Address, const void *Decoder) {
3438   DecodeStatus S = MCDisassembler::Success;
3439 
3440   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3441   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3442   unsigned imm = fieldFromInstruction(Insn, 0, 4);
3443   imm |= fieldFromInstruction(Insn, 16, 3) << 4;
3444   imm |= fieldFromInstruction(Insn, 24, 1) << 7;
3445   imm |= fieldFromInstruction(Insn, 8, 4) << 8;
3446   imm |= fieldFromInstruction(Insn, 5, 1) << 12;
3447   unsigned Q = fieldFromInstruction(Insn, 6, 1);
3448 
3449   if (Q) {
3450     if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3451     return MCDisassembler::Fail;
3452   } else {
3453     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3454     return MCDisassembler::Fail;
3455   }
3456 
3457   Inst.addOperand(MCOperand::createImm(imm));
3458 
3459   switch (Inst.getOpcode()) {
3460     case ARM::VORRiv4i16:
3461     case ARM::VORRiv2i32:
3462     case ARM::VBICiv4i16:
3463     case ARM::VBICiv2i32:
3464       if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3465         return MCDisassembler::Fail;
3466       break;
3467     case ARM::VORRiv8i16:
3468     case ARM::VORRiv4i32:
3469     case ARM::VBICiv8i16:
3470     case ARM::VBICiv4i32:
3471       if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3472         return MCDisassembler::Fail;
3473       break;
3474     default:
3475       break;
3476   }
3477 
3478   return S;
3479 }
3480 
3481 static DecodeStatus
3482 DecodeMVEModImmInstruction(MCInst &Inst, unsigned Insn,
3483                            uint64_t Address, const void *Decoder) {
3484   DecodeStatus S = MCDisassembler::Success;
3485 
3486   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
3487                  fieldFromInstruction(Insn, 13, 3));
3488   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
3489   unsigned imm = fieldFromInstruction(Insn, 0, 4);
3490   imm |= fieldFromInstruction(Insn, 16, 3) << 4;
3491   imm |= fieldFromInstruction(Insn, 28, 1) << 7;
3492   imm |= cmode                             << 8;
3493   imm |= fieldFromInstruction(Insn, 5, 1)  << 12;
3494 
3495   if (cmode == 0xF && Inst.getOpcode() == ARM::MVE_VMVNimmi32)
3496     return MCDisassembler::Fail;
3497 
3498   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
3499     return MCDisassembler::Fail;
3500 
3501   Inst.addOperand(MCOperand::createImm(imm));
3502 
3503   Inst.addOperand(MCOperand::createImm(ARMVCC::None));
3504   Inst.addOperand(MCOperand::createReg(0));
3505   Inst.addOperand(MCOperand::createImm(0));
3506 
3507   return S;
3508 }
3509 
3510 static DecodeStatus DecodeMVEVADCInstruction(MCInst &Inst, unsigned Insn,
3511                                uint64_t Address, const void *Decoder) {
3512   DecodeStatus S = MCDisassembler::Success;
3513 
3514   unsigned Qd = fieldFromInstruction(Insn, 13, 3);
3515   Qd |= fieldFromInstruction(Insn, 22, 1) << 3;
3516   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
3517     return MCDisassembler::Fail;
3518   Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
3519 
3520   unsigned Qn = fieldFromInstruction(Insn, 17, 3);
3521   Qn |= fieldFromInstruction(Insn, 7, 1) << 3;
3522   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qn, Address, Decoder)))
3523     return MCDisassembler::Fail;
3524   unsigned Qm = fieldFromInstruction(Insn, 1, 3);
3525   Qm |= fieldFromInstruction(Insn, 5, 1) << 3;
3526   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
3527     return MCDisassembler::Fail;
3528   if (!fieldFromInstruction(Insn, 12, 1)) // I bit clear => need input FPSCR
3529     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
3530   Inst.addOperand(MCOperand::createImm(Qd));
3531 
3532   return S;
3533 }
3534 
3535 static DecodeStatus DecodeVSHLMaxInstruction(MCInst &Inst, unsigned Insn,
3536                                         uint64_t Address, const void *Decoder) {
3537   DecodeStatus S = MCDisassembler::Success;
3538 
3539   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3540   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3541   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3542   Rm |= fieldFromInstruction(Insn, 5, 1) << 4;
3543   unsigned size = fieldFromInstruction(Insn, 18, 2);
3544 
3545   if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3546     return MCDisassembler::Fail;
3547   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
3548     return MCDisassembler::Fail;
3549   Inst.addOperand(MCOperand::createImm(8 << size));
3550 
3551   return S;
3552 }
3553 
3554 static DecodeStatus DecodeShiftRight8Imm(MCInst &Inst, unsigned Val,
3555                                uint64_t Address, const void *Decoder) {
3556   Inst.addOperand(MCOperand::createImm(8 - Val));
3557   return MCDisassembler::Success;
3558 }
3559 
3560 static DecodeStatus DecodeShiftRight16Imm(MCInst &Inst, unsigned Val,
3561                                uint64_t Address, const void *Decoder) {
3562   Inst.addOperand(MCOperand::createImm(16 - Val));
3563   return MCDisassembler::Success;
3564 }
3565 
3566 static DecodeStatus DecodeShiftRight32Imm(MCInst &Inst, unsigned Val,
3567                                uint64_t Address, const void *Decoder) {
3568   Inst.addOperand(MCOperand::createImm(32 - Val));
3569   return MCDisassembler::Success;
3570 }
3571 
3572 static DecodeStatus DecodeShiftRight64Imm(MCInst &Inst, unsigned Val,
3573                                uint64_t Address, const void *Decoder) {
3574   Inst.addOperand(MCOperand::createImm(64 - Val));
3575   return MCDisassembler::Success;
3576 }
3577 
3578 static DecodeStatus DecodeTBLInstruction(MCInst &Inst, unsigned Insn,
3579                                uint64_t Address, const void *Decoder) {
3580   DecodeStatus S = MCDisassembler::Success;
3581 
3582   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3583   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3584   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3585   Rn |= fieldFromInstruction(Insn, 7, 1) << 4;
3586   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3587   Rm |= fieldFromInstruction(Insn, 5, 1) << 4;
3588   unsigned op = fieldFromInstruction(Insn, 6, 1);
3589 
3590   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3591     return MCDisassembler::Fail;
3592   if (op) {
3593     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3594     return MCDisassembler::Fail; // Writeback
3595   }
3596 
3597   switch (Inst.getOpcode()) {
3598   case ARM::VTBL2:
3599   case ARM::VTBX2:
3600     if (!Check(S, DecodeDPairRegisterClass(Inst, Rn, Address, Decoder)))
3601       return MCDisassembler::Fail;
3602     break;
3603   default:
3604     if (!Check(S, DecodeDPRRegisterClass(Inst, Rn, Address, Decoder)))
3605       return MCDisassembler::Fail;
3606   }
3607 
3608   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
3609     return MCDisassembler::Fail;
3610 
3611   return S;
3612 }
3613 
3614 static DecodeStatus DecodeThumbAddSpecialReg(MCInst &Inst, uint16_t Insn,
3615                                      uint64_t Address, const void *Decoder) {
3616   DecodeStatus S = MCDisassembler::Success;
3617 
3618   unsigned dst = fieldFromInstruction(Insn, 8, 3);
3619   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3620 
3621   if (!Check(S, DecodetGPRRegisterClass(Inst, dst, Address, Decoder)))
3622     return MCDisassembler::Fail;
3623 
3624   switch(Inst.getOpcode()) {
3625     default:
3626       return MCDisassembler::Fail;
3627     case ARM::tADR:
3628       break; // tADR does not explicitly represent the PC as an operand.
3629     case ARM::tADDrSPi:
3630       Inst.addOperand(MCOperand::createReg(ARM::SP));
3631       break;
3632   }
3633 
3634   Inst.addOperand(MCOperand::createImm(imm));
3635   return S;
3636 }
3637 
3638 static DecodeStatus DecodeThumbBROperand(MCInst &Inst, unsigned Val,
3639                                  uint64_t Address, const void *Decoder) {
3640   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<12>(Val<<1) + 4,
3641                                 true, 2, Inst, Decoder))
3642     Inst.addOperand(MCOperand::createImm(SignExtend32<12>(Val << 1)));
3643   return MCDisassembler::Success;
3644 }
3645 
3646 static DecodeStatus DecodeT2BROperand(MCInst &Inst, unsigned Val,
3647                                  uint64_t Address, const void *Decoder) {
3648   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<21>(Val) + 4,
3649                                 true, 4, Inst, Decoder))
3650     Inst.addOperand(MCOperand::createImm(SignExtend32<21>(Val)));
3651   return MCDisassembler::Success;
3652 }
3653 
3654 static DecodeStatus DecodeThumbCmpBROperand(MCInst &Inst, unsigned Val,
3655                                  uint64_t Address, const void *Decoder) {
3656   if (!tryAddingSymbolicOperand(Address, Address + (Val<<1) + 4,
3657                                 true, 2, Inst, Decoder))
3658     Inst.addOperand(MCOperand::createImm(Val << 1));
3659   return MCDisassembler::Success;
3660 }
3661 
3662 static DecodeStatus DecodeThumbAddrModeRR(MCInst &Inst, unsigned Val,
3663                                  uint64_t Address, const void *Decoder) {
3664   DecodeStatus S = MCDisassembler::Success;
3665 
3666   unsigned Rn = fieldFromInstruction(Val, 0, 3);
3667   unsigned Rm = fieldFromInstruction(Val, 3, 3);
3668 
3669   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
3670     return MCDisassembler::Fail;
3671   if (!Check(S, DecodetGPRRegisterClass(Inst, Rm, Address, Decoder)))
3672     return MCDisassembler::Fail;
3673 
3674   return S;
3675 }
3676 
3677 static DecodeStatus DecodeThumbAddrModeIS(MCInst &Inst, unsigned Val,
3678                                   uint64_t Address, const void *Decoder) {
3679   DecodeStatus S = MCDisassembler::Success;
3680 
3681   unsigned Rn = fieldFromInstruction(Val, 0, 3);
3682   unsigned imm = fieldFromInstruction(Val, 3, 5);
3683 
3684   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
3685     return MCDisassembler::Fail;
3686   Inst.addOperand(MCOperand::createImm(imm));
3687 
3688   return S;
3689 }
3690 
3691 static DecodeStatus DecodeThumbAddrModePC(MCInst &Inst, unsigned Val,
3692                                   uint64_t Address, const void *Decoder) {
3693   unsigned imm = Val << 2;
3694 
3695   Inst.addOperand(MCOperand::createImm(imm));
3696   tryAddingPcLoadReferenceComment(Address, (Address & ~2u) + imm + 4, Decoder);
3697 
3698   return MCDisassembler::Success;
3699 }
3700 
3701 static DecodeStatus DecodeThumbAddrModeSP(MCInst &Inst, unsigned Val,
3702                                   uint64_t Address, const void *Decoder) {
3703   Inst.addOperand(MCOperand::createReg(ARM::SP));
3704   Inst.addOperand(MCOperand::createImm(Val));
3705 
3706   return MCDisassembler::Success;
3707 }
3708 
3709 static DecodeStatus DecodeT2AddrModeSOReg(MCInst &Inst, unsigned Val,
3710                                   uint64_t Address, const void *Decoder) {
3711   DecodeStatus S = MCDisassembler::Success;
3712 
3713   unsigned Rn = fieldFromInstruction(Val, 6, 4);
3714   unsigned Rm = fieldFromInstruction(Val, 2, 4);
3715   unsigned imm = fieldFromInstruction(Val, 0, 2);
3716 
3717   // Thumb stores cannot use PC as dest register.
3718   switch (Inst.getOpcode()) {
3719   case ARM::t2STRHs:
3720   case ARM::t2STRBs:
3721   case ARM::t2STRs:
3722     if (Rn == 15)
3723       return MCDisassembler::Fail;
3724     break;
3725   default:
3726     break;
3727   }
3728 
3729   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3730     return MCDisassembler::Fail;
3731   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
3732     return MCDisassembler::Fail;
3733   Inst.addOperand(MCOperand::createImm(imm));
3734 
3735   return S;
3736 }
3737 
3738 static DecodeStatus DecodeT2LoadShift(MCInst &Inst, unsigned Insn,
3739                               uint64_t Address, const void *Decoder) {
3740   DecodeStatus S = MCDisassembler::Success;
3741 
3742   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3743   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3744 
3745   const FeatureBitset &featureBits =
3746     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3747 
3748   bool hasMP = featureBits[ARM::FeatureMP];
3749   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3750 
3751   if (Rn == 15) {
3752     switch (Inst.getOpcode()) {
3753     case ARM::t2LDRBs:
3754       Inst.setOpcode(ARM::t2LDRBpci);
3755       break;
3756     case ARM::t2LDRHs:
3757       Inst.setOpcode(ARM::t2LDRHpci);
3758       break;
3759     case ARM::t2LDRSHs:
3760       Inst.setOpcode(ARM::t2LDRSHpci);
3761       break;
3762     case ARM::t2LDRSBs:
3763       Inst.setOpcode(ARM::t2LDRSBpci);
3764       break;
3765     case ARM::t2LDRs:
3766       Inst.setOpcode(ARM::t2LDRpci);
3767       break;
3768     case ARM::t2PLDs:
3769       Inst.setOpcode(ARM::t2PLDpci);
3770       break;
3771     case ARM::t2PLIs:
3772       Inst.setOpcode(ARM::t2PLIpci);
3773       break;
3774     default:
3775       return MCDisassembler::Fail;
3776     }
3777 
3778     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3779   }
3780 
3781   if (Rt == 15) {
3782     switch (Inst.getOpcode()) {
3783     case ARM::t2LDRSHs:
3784       return MCDisassembler::Fail;
3785     case ARM::t2LDRHs:
3786       Inst.setOpcode(ARM::t2PLDWs);
3787       break;
3788     case ARM::t2LDRSBs:
3789       Inst.setOpcode(ARM::t2PLIs);
3790       break;
3791     default:
3792       break;
3793     }
3794   }
3795 
3796   switch (Inst.getOpcode()) {
3797     case ARM::t2PLDs:
3798       break;
3799     case ARM::t2PLIs:
3800       if (!hasV7Ops)
3801         return MCDisassembler::Fail;
3802       break;
3803     case ARM::t2PLDWs:
3804       if (!hasV7Ops || !hasMP)
3805         return MCDisassembler::Fail;
3806       break;
3807     default:
3808       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3809         return MCDisassembler::Fail;
3810   }
3811 
3812   unsigned addrmode = fieldFromInstruction(Insn, 4, 2);
3813   addrmode |= fieldFromInstruction(Insn, 0, 4) << 2;
3814   addrmode |= fieldFromInstruction(Insn, 16, 4) << 6;
3815   if (!Check(S, DecodeT2AddrModeSOReg(Inst, addrmode, Address, Decoder)))
3816     return MCDisassembler::Fail;
3817 
3818   return S;
3819 }
3820 
3821 static DecodeStatus DecodeT2LoadImm8(MCInst &Inst, unsigned Insn,
3822                                 uint64_t Address, const void* Decoder) {
3823   DecodeStatus S = MCDisassembler::Success;
3824 
3825   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3826   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3827   unsigned U = fieldFromInstruction(Insn, 9, 1);
3828   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3829   imm |= (U << 8);
3830   imm |= (Rn << 9);
3831   unsigned add = fieldFromInstruction(Insn, 9, 1);
3832 
3833   const FeatureBitset &featureBits =
3834     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3835 
3836   bool hasMP = featureBits[ARM::FeatureMP];
3837   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3838 
3839   if (Rn == 15) {
3840     switch (Inst.getOpcode()) {
3841     case ARM::t2LDRi8:
3842       Inst.setOpcode(ARM::t2LDRpci);
3843       break;
3844     case ARM::t2LDRBi8:
3845       Inst.setOpcode(ARM::t2LDRBpci);
3846       break;
3847     case ARM::t2LDRSBi8:
3848       Inst.setOpcode(ARM::t2LDRSBpci);
3849       break;
3850     case ARM::t2LDRHi8:
3851       Inst.setOpcode(ARM::t2LDRHpci);
3852       break;
3853     case ARM::t2LDRSHi8:
3854       Inst.setOpcode(ARM::t2LDRSHpci);
3855       break;
3856     case ARM::t2PLDi8:
3857       Inst.setOpcode(ARM::t2PLDpci);
3858       break;
3859     case ARM::t2PLIi8:
3860       Inst.setOpcode(ARM::t2PLIpci);
3861       break;
3862     default:
3863       return MCDisassembler::Fail;
3864     }
3865     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3866   }
3867 
3868   if (Rt == 15) {
3869     switch (Inst.getOpcode()) {
3870     case ARM::t2LDRSHi8:
3871       return MCDisassembler::Fail;
3872     case ARM::t2LDRHi8:
3873       if (!add)
3874         Inst.setOpcode(ARM::t2PLDWi8);
3875       break;
3876     case ARM::t2LDRSBi8:
3877       Inst.setOpcode(ARM::t2PLIi8);
3878       break;
3879     default:
3880       break;
3881     }
3882   }
3883 
3884   switch (Inst.getOpcode()) {
3885   case ARM::t2PLDi8:
3886     break;
3887   case ARM::t2PLIi8:
3888     if (!hasV7Ops)
3889       return MCDisassembler::Fail;
3890     break;
3891   case ARM::t2PLDWi8:
3892       if (!hasV7Ops || !hasMP)
3893         return MCDisassembler::Fail;
3894       break;
3895   default:
3896     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3897       return MCDisassembler::Fail;
3898   }
3899 
3900   if (!Check(S, DecodeT2AddrModeImm8(Inst, imm, Address, Decoder)))
3901     return MCDisassembler::Fail;
3902   return S;
3903 }
3904 
3905 static DecodeStatus DecodeT2LoadImm12(MCInst &Inst, unsigned Insn,
3906                                 uint64_t Address, const void* Decoder) {
3907   DecodeStatus S = MCDisassembler::Success;
3908 
3909   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3910   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3911   unsigned imm = fieldFromInstruction(Insn, 0, 12);
3912   imm |= (Rn << 13);
3913 
3914   const FeatureBitset &featureBits =
3915     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3916 
3917   bool hasMP = featureBits[ARM::FeatureMP];
3918   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3919 
3920   if (Rn == 15) {
3921     switch (Inst.getOpcode()) {
3922     case ARM::t2LDRi12:
3923       Inst.setOpcode(ARM::t2LDRpci);
3924       break;
3925     case ARM::t2LDRHi12:
3926       Inst.setOpcode(ARM::t2LDRHpci);
3927       break;
3928     case ARM::t2LDRSHi12:
3929       Inst.setOpcode(ARM::t2LDRSHpci);
3930       break;
3931     case ARM::t2LDRBi12:
3932       Inst.setOpcode(ARM::t2LDRBpci);
3933       break;
3934     case ARM::t2LDRSBi12:
3935       Inst.setOpcode(ARM::t2LDRSBpci);
3936       break;
3937     case ARM::t2PLDi12:
3938       Inst.setOpcode(ARM::t2PLDpci);
3939       break;
3940     case ARM::t2PLIi12:
3941       Inst.setOpcode(ARM::t2PLIpci);
3942       break;
3943     default:
3944       return MCDisassembler::Fail;
3945     }
3946     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3947   }
3948 
3949   if (Rt == 15) {
3950     switch (Inst.getOpcode()) {
3951     case ARM::t2LDRSHi12:
3952       return MCDisassembler::Fail;
3953     case ARM::t2LDRHi12:
3954       Inst.setOpcode(ARM::t2PLDWi12);
3955       break;
3956     case ARM::t2LDRSBi12:
3957       Inst.setOpcode(ARM::t2PLIi12);
3958       break;
3959     default:
3960       break;
3961     }
3962   }
3963 
3964   switch (Inst.getOpcode()) {
3965   case ARM::t2PLDi12:
3966     break;
3967   case ARM::t2PLIi12:
3968     if (!hasV7Ops)
3969       return MCDisassembler::Fail;
3970     break;
3971   case ARM::t2PLDWi12:
3972       if (!hasV7Ops || !hasMP)
3973         return MCDisassembler::Fail;
3974       break;
3975   default:
3976     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3977       return MCDisassembler::Fail;
3978   }
3979 
3980   if (!Check(S, DecodeT2AddrModeImm12(Inst, imm, Address, Decoder)))
3981     return MCDisassembler::Fail;
3982   return S;
3983 }
3984 
3985 static DecodeStatus DecodeT2LoadT(MCInst &Inst, unsigned Insn,
3986                                 uint64_t Address, const void* Decoder) {
3987   DecodeStatus S = MCDisassembler::Success;
3988 
3989   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3990   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3991   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3992   imm |= (Rn << 9);
3993 
3994   if (Rn == 15) {
3995     switch (Inst.getOpcode()) {
3996     case ARM::t2LDRT:
3997       Inst.setOpcode(ARM::t2LDRpci);
3998       break;
3999     case ARM::t2LDRBT:
4000       Inst.setOpcode(ARM::t2LDRBpci);
4001       break;
4002     case ARM::t2LDRHT:
4003       Inst.setOpcode(ARM::t2LDRHpci);
4004       break;
4005     case ARM::t2LDRSBT:
4006       Inst.setOpcode(ARM::t2LDRSBpci);
4007       break;
4008     case ARM::t2LDRSHT:
4009       Inst.setOpcode(ARM::t2LDRSHpci);
4010       break;
4011     default:
4012       return MCDisassembler::Fail;
4013     }
4014     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
4015   }
4016 
4017   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
4018     return MCDisassembler::Fail;
4019   if (!Check(S, DecodeT2AddrModeImm8(Inst, imm, Address, Decoder)))
4020     return MCDisassembler::Fail;
4021   return S;
4022 }
4023 
4024 static DecodeStatus DecodeT2LoadLabel(MCInst &Inst, unsigned Insn,
4025                                 uint64_t Address, const void* Decoder) {
4026   DecodeStatus S = MCDisassembler::Success;
4027 
4028   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4029   unsigned U = fieldFromInstruction(Insn, 23, 1);
4030   int imm = fieldFromInstruction(Insn, 0, 12);
4031 
4032   const FeatureBitset &featureBits =
4033     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4034 
4035   bool hasV7Ops = featureBits[ARM::HasV7Ops];
4036 
4037   if (Rt == 15) {
4038     switch (Inst.getOpcode()) {
4039       case ARM::t2LDRBpci:
4040       case ARM::t2LDRHpci:
4041         Inst.setOpcode(ARM::t2PLDpci);
4042         break;
4043       case ARM::t2LDRSBpci:
4044         Inst.setOpcode(ARM::t2PLIpci);
4045         break;
4046       case ARM::t2LDRSHpci:
4047         return MCDisassembler::Fail;
4048       default:
4049         break;
4050     }
4051   }
4052 
4053   switch(Inst.getOpcode()) {
4054   case ARM::t2PLDpci:
4055     break;
4056   case ARM::t2PLIpci:
4057     if (!hasV7Ops)
4058       return MCDisassembler::Fail;
4059     break;
4060   default:
4061     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4062       return MCDisassembler::Fail;
4063   }
4064 
4065   if (!U) {
4066     // Special case for #-0.
4067     if (imm == 0)
4068       imm = INT32_MIN;
4069     else
4070       imm = -imm;
4071   }
4072   Inst.addOperand(MCOperand::createImm(imm));
4073 
4074   return S;
4075 }
4076 
4077 static DecodeStatus DecodeT2Imm8S4(MCInst &Inst, unsigned Val,
4078                            uint64_t Address, const void *Decoder) {
4079   if (Val == 0)
4080     Inst.addOperand(MCOperand::createImm(INT32_MIN));
4081   else {
4082     int imm = Val & 0xFF;
4083 
4084     if (!(Val & 0x100)) imm *= -1;
4085     Inst.addOperand(MCOperand::createImm(imm * 4));
4086   }
4087 
4088   return MCDisassembler::Success;
4089 }
4090 
4091 static DecodeStatus DecodeT2Imm7S4(MCInst &Inst, unsigned Val, uint64_t Address,
4092                                    const void *Decoder) {
4093   if (Val == 0)
4094     Inst.addOperand(MCOperand::createImm(INT32_MIN));
4095   else {
4096     int imm = Val & 0x7F;
4097 
4098     if (!(Val & 0x80))
4099       imm *= -1;
4100     Inst.addOperand(MCOperand::createImm(imm * 4));
4101   }
4102 
4103   return MCDisassembler::Success;
4104 }
4105 
4106 static DecodeStatus DecodeT2AddrModeImm8s4(MCInst &Inst, unsigned Val,
4107                                    uint64_t Address, const void *Decoder) {
4108   DecodeStatus S = MCDisassembler::Success;
4109 
4110   unsigned Rn = fieldFromInstruction(Val, 9, 4);
4111   unsigned imm = fieldFromInstruction(Val, 0, 9);
4112 
4113   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4114     return MCDisassembler::Fail;
4115   if (!Check(S, DecodeT2Imm8S4(Inst, imm, Address, Decoder)))
4116     return MCDisassembler::Fail;
4117 
4118   return S;
4119 }
4120 
4121 static DecodeStatus DecodeT2AddrModeImm7s4(MCInst &Inst, unsigned Val,
4122                                            uint64_t Address,
4123                                            const void *Decoder) {
4124   DecodeStatus S = MCDisassembler::Success;
4125 
4126   unsigned Rn = fieldFromInstruction(Val, 8, 4);
4127   unsigned imm = fieldFromInstruction(Val, 0, 8);
4128 
4129   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4130     return MCDisassembler::Fail;
4131   if (!Check(S, DecodeT2Imm7S4(Inst, imm, Address, Decoder)))
4132     return MCDisassembler::Fail;
4133 
4134   return S;
4135 }
4136 
4137 static DecodeStatus DecodeT2AddrModeImm0_1020s4(MCInst &Inst,unsigned Val,
4138                                    uint64_t Address, const void *Decoder) {
4139   DecodeStatus S = MCDisassembler::Success;
4140 
4141   unsigned Rn = fieldFromInstruction(Val, 8, 4);
4142   unsigned imm = fieldFromInstruction(Val, 0, 8);
4143 
4144   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4145     return MCDisassembler::Fail;
4146 
4147   Inst.addOperand(MCOperand::createImm(imm));
4148 
4149   return S;
4150 }
4151 
4152 static DecodeStatus DecodeT2Imm8(MCInst &Inst, unsigned Val,
4153                          uint64_t Address, const void *Decoder) {
4154   int imm = Val & 0xFF;
4155   if (Val == 0)
4156     imm = INT32_MIN;
4157   else if (!(Val & 0x100))
4158     imm *= -1;
4159   Inst.addOperand(MCOperand::createImm(imm));
4160 
4161   return MCDisassembler::Success;
4162 }
4163 
4164 template<int shift>
4165 static DecodeStatus DecodeT2Imm7(MCInst &Inst, unsigned Val,
4166                          uint64_t Address, const void *Decoder) {
4167   int imm = Val & 0x7F;
4168   if (Val == 0)
4169     imm = INT32_MIN;
4170   else if (!(Val & 0x80))
4171     imm *= -1;
4172   if (imm != INT32_MIN)
4173     imm <<= shift;
4174   Inst.addOperand(MCOperand::createImm(imm));
4175 
4176   return MCDisassembler::Success;
4177 }
4178 
4179 static DecodeStatus DecodeT2AddrModeImm8(MCInst &Inst, unsigned Val,
4180                                  uint64_t Address, const void *Decoder) {
4181   DecodeStatus S = MCDisassembler::Success;
4182 
4183   unsigned Rn = fieldFromInstruction(Val, 9, 4);
4184   unsigned imm = fieldFromInstruction(Val, 0, 9);
4185 
4186   // Thumb stores cannot use PC as dest register.
4187   switch (Inst.getOpcode()) {
4188   case ARM::t2STRT:
4189   case ARM::t2STRBT:
4190   case ARM::t2STRHT:
4191   case ARM::t2STRi8:
4192   case ARM::t2STRHi8:
4193   case ARM::t2STRBi8:
4194     if (Rn == 15)
4195       return MCDisassembler::Fail;
4196     break;
4197   default:
4198     break;
4199   }
4200 
4201   // Some instructions always use an additive offset.
4202   switch (Inst.getOpcode()) {
4203     case ARM::t2LDRT:
4204     case ARM::t2LDRBT:
4205     case ARM::t2LDRHT:
4206     case ARM::t2LDRSBT:
4207     case ARM::t2LDRSHT:
4208     case ARM::t2STRT:
4209     case ARM::t2STRBT:
4210     case ARM::t2STRHT:
4211       imm |= 0x100;
4212       break;
4213     default:
4214       break;
4215   }
4216 
4217   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4218     return MCDisassembler::Fail;
4219   if (!Check(S, DecodeT2Imm8(Inst, imm, Address, Decoder)))
4220     return MCDisassembler::Fail;
4221 
4222   return S;
4223 }
4224 
4225 template<int shift>
4226 static DecodeStatus DecodeTAddrModeImm7(MCInst &Inst, unsigned Val,
4227                                          uint64_t Address,
4228                                          const void *Decoder) {
4229   DecodeStatus S = MCDisassembler::Success;
4230 
4231   unsigned Rn = fieldFromInstruction(Val, 8, 3);
4232   unsigned imm = fieldFromInstruction(Val, 0, 8);
4233 
4234   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
4235     return MCDisassembler::Fail;
4236   if (!Check(S, DecodeT2Imm7<shift>(Inst, imm, Address, Decoder)))
4237     return MCDisassembler::Fail;
4238 
4239   return S;
4240 }
4241 
4242 template<int shift, int WriteBack>
4243 static DecodeStatus DecodeT2AddrModeImm7(MCInst &Inst, unsigned Val,
4244                                          uint64_t Address,
4245                                          const void *Decoder) {
4246   DecodeStatus S = MCDisassembler::Success;
4247 
4248   unsigned Rn = fieldFromInstruction(Val, 8, 4);
4249   unsigned imm = fieldFromInstruction(Val, 0, 8);
4250   if (WriteBack) {
4251     if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
4252       return MCDisassembler::Fail;
4253   } else if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4254     return MCDisassembler::Fail;
4255   if (!Check(S, DecodeT2Imm7<shift>(Inst, imm, Address, Decoder)))
4256     return MCDisassembler::Fail;
4257 
4258   return S;
4259 }
4260 
4261 static DecodeStatus DecodeT2LdStPre(MCInst &Inst, unsigned Insn,
4262                                     uint64_t Address, const void *Decoder) {
4263   DecodeStatus S = MCDisassembler::Success;
4264 
4265   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4266   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4267   unsigned addr = fieldFromInstruction(Insn, 0, 8);
4268   addr |= fieldFromInstruction(Insn, 9, 1) << 8;
4269   addr |= Rn << 9;
4270   unsigned load = fieldFromInstruction(Insn, 20, 1);
4271 
4272   if (Rn == 15) {
4273     switch (Inst.getOpcode()) {
4274     case ARM::t2LDR_PRE:
4275     case ARM::t2LDR_POST:
4276       Inst.setOpcode(ARM::t2LDRpci);
4277       break;
4278     case ARM::t2LDRB_PRE:
4279     case ARM::t2LDRB_POST:
4280       Inst.setOpcode(ARM::t2LDRBpci);
4281       break;
4282     case ARM::t2LDRH_PRE:
4283     case ARM::t2LDRH_POST:
4284       Inst.setOpcode(ARM::t2LDRHpci);
4285       break;
4286     case ARM::t2LDRSB_PRE:
4287     case ARM::t2LDRSB_POST:
4288       if (Rt == 15)
4289         Inst.setOpcode(ARM::t2PLIpci);
4290       else
4291         Inst.setOpcode(ARM::t2LDRSBpci);
4292       break;
4293     case ARM::t2LDRSH_PRE:
4294     case ARM::t2LDRSH_POST:
4295       Inst.setOpcode(ARM::t2LDRSHpci);
4296       break;
4297     default:
4298       return MCDisassembler::Fail;
4299     }
4300     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
4301   }
4302 
4303   if (!load) {
4304     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4305       return MCDisassembler::Fail;
4306   }
4307 
4308   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4309     return MCDisassembler::Fail;
4310 
4311   if (load) {
4312     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4313       return MCDisassembler::Fail;
4314   }
4315 
4316   if (!Check(S, DecodeT2AddrModeImm8(Inst, addr, Address, Decoder)))
4317     return MCDisassembler::Fail;
4318 
4319   return S;
4320 }
4321 
4322 static DecodeStatus DecodeT2AddrModeImm12(MCInst &Inst, unsigned Val,
4323                                   uint64_t Address, const void *Decoder) {
4324   DecodeStatus S = MCDisassembler::Success;
4325 
4326   unsigned Rn = fieldFromInstruction(Val, 13, 4);
4327   unsigned imm = fieldFromInstruction(Val, 0, 12);
4328 
4329   // Thumb stores cannot use PC as dest register.
4330   switch (Inst.getOpcode()) {
4331   case ARM::t2STRi12:
4332   case ARM::t2STRBi12:
4333   case ARM::t2STRHi12:
4334     if (Rn == 15)
4335       return MCDisassembler::Fail;
4336     break;
4337   default:
4338     break;
4339   }
4340 
4341   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4342     return MCDisassembler::Fail;
4343   Inst.addOperand(MCOperand::createImm(imm));
4344 
4345   return S;
4346 }
4347 
4348 static DecodeStatus DecodeThumbAddSPImm(MCInst &Inst, uint16_t Insn,
4349                                 uint64_t Address, const void *Decoder) {
4350   unsigned imm = fieldFromInstruction(Insn, 0, 7);
4351 
4352   Inst.addOperand(MCOperand::createReg(ARM::SP));
4353   Inst.addOperand(MCOperand::createReg(ARM::SP));
4354   Inst.addOperand(MCOperand::createImm(imm));
4355 
4356   return MCDisassembler::Success;
4357 }
4358 
4359 static DecodeStatus DecodeThumbAddSPReg(MCInst &Inst, uint16_t Insn,
4360                                 uint64_t Address, const void *Decoder) {
4361   DecodeStatus S = MCDisassembler::Success;
4362 
4363   if (Inst.getOpcode() == ARM::tADDrSP) {
4364     unsigned Rdm = fieldFromInstruction(Insn, 0, 3);
4365     Rdm |= fieldFromInstruction(Insn, 7, 1) << 3;
4366 
4367     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
4368     return MCDisassembler::Fail;
4369     Inst.addOperand(MCOperand::createReg(ARM::SP));
4370     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
4371     return MCDisassembler::Fail;
4372   } else if (Inst.getOpcode() == ARM::tADDspr) {
4373     unsigned Rm = fieldFromInstruction(Insn, 3, 4);
4374 
4375     Inst.addOperand(MCOperand::createReg(ARM::SP));
4376     Inst.addOperand(MCOperand::createReg(ARM::SP));
4377     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4378     return MCDisassembler::Fail;
4379   }
4380 
4381   return S;
4382 }
4383 
4384 static DecodeStatus DecodeThumbCPS(MCInst &Inst, uint16_t Insn,
4385                            uint64_t Address, const void *Decoder) {
4386   unsigned imod = fieldFromInstruction(Insn, 4, 1) | 0x2;
4387   unsigned flags = fieldFromInstruction(Insn, 0, 3);
4388 
4389   Inst.addOperand(MCOperand::createImm(imod));
4390   Inst.addOperand(MCOperand::createImm(flags));
4391 
4392   return MCDisassembler::Success;
4393 }
4394 
4395 static DecodeStatus DecodePostIdxReg(MCInst &Inst, unsigned Insn,
4396                              uint64_t Address, const void *Decoder) {
4397   DecodeStatus S = MCDisassembler::Success;
4398   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4399   unsigned add = fieldFromInstruction(Insn, 4, 1);
4400 
4401   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
4402     return MCDisassembler::Fail;
4403   Inst.addOperand(MCOperand::createImm(add));
4404 
4405   return S;
4406 }
4407 
4408 static DecodeStatus DecodeMveAddrModeRQ(MCInst &Inst, unsigned Insn,
4409                              uint64_t Address, const void *Decoder) {
4410   DecodeStatus S = MCDisassembler::Success;
4411   unsigned Rn = fieldFromInstruction(Insn, 3, 4);
4412   unsigned Qm = fieldFromInstruction(Insn, 0, 3);
4413 
4414   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4415     return MCDisassembler::Fail;
4416   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
4417     return MCDisassembler::Fail;
4418 
4419   return S;
4420 }
4421 
4422 template<int shift>
4423 static DecodeStatus DecodeMveAddrModeQ(MCInst &Inst, unsigned Insn,
4424                              uint64_t Address, const void *Decoder) {
4425   DecodeStatus S = MCDisassembler::Success;
4426   unsigned Qm = fieldFromInstruction(Insn, 8, 3);
4427   int imm = fieldFromInstruction(Insn, 0, 7);
4428 
4429   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
4430     return MCDisassembler::Fail;
4431 
4432   if(!fieldFromInstruction(Insn, 7, 1)) {
4433     if (imm == 0)
4434       imm = INT32_MIN;                 // indicate -0
4435     else
4436       imm *= -1;
4437   }
4438   if (imm != INT32_MIN)
4439     imm <<= shift;
4440   Inst.addOperand(MCOperand::createImm(imm));
4441 
4442   return S;
4443 }
4444 
4445 static DecodeStatus DecodeThumbBLXOffset(MCInst &Inst, unsigned Val,
4446                                  uint64_t Address, const void *Decoder) {
4447   // Val is passed in as S:J1:J2:imm10H:imm10L:'0'
4448   // Note only one trailing zero not two.  Also the J1 and J2 values are from
4449   // the encoded instruction.  So here change to I1 and I2 values via:
4450   // I1 = NOT(J1 EOR S);
4451   // I2 = NOT(J2 EOR S);
4452   // and build the imm32 with two trailing zeros as documented:
4453   // imm32 = SignExtend(S:I1:I2:imm10H:imm10L:'00', 32);
4454   unsigned S = (Val >> 23) & 1;
4455   unsigned J1 = (Val >> 22) & 1;
4456   unsigned J2 = (Val >> 21) & 1;
4457   unsigned I1 = !(J1 ^ S);
4458   unsigned I2 = !(J2 ^ S);
4459   unsigned tmp = (Val & ~0x600000) | (I1 << 22) | (I2 << 21);
4460   int imm32 = SignExtend32<25>(tmp << 1);
4461 
4462   if (!tryAddingSymbolicOperand(Address,
4463                                 (Address & ~2u) + imm32 + 4,
4464                                 true, 4, Inst, Decoder))
4465     Inst.addOperand(MCOperand::createImm(imm32));
4466   return MCDisassembler::Success;
4467 }
4468 
4469 static DecodeStatus DecodeCoprocessor(MCInst &Inst, unsigned Val,
4470                               uint64_t Address, const void *Decoder) {
4471   if (Val == 0xA || Val == 0xB)
4472     return MCDisassembler::Fail;
4473 
4474   const FeatureBitset &featureBits =
4475     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4476 
4477   if (featureBits[ARM::HasV8Ops] && !(Val == 14 || Val == 15))
4478     return MCDisassembler::Fail;
4479 
4480   // For Armv8.1-M Mainline coprocessors matching 100x,101x or 111x should
4481   // decode as VFP/MVE instructions.
4482   if (featureBits[ARM::HasV8_1MMainlineOps] &&
4483       ((Val & 0xE) == 0x8 || (Val & 0xE) == 0xA ||
4484        (Val & 0xE) == 0xE))
4485     return MCDisassembler::Fail;
4486 
4487   Inst.addOperand(MCOperand::createImm(Val));
4488   return MCDisassembler::Success;
4489 }
4490 
4491 static DecodeStatus
4492 DecodeThumbTableBranch(MCInst &Inst, unsigned Insn,
4493                        uint64_t Address, const void *Decoder) {
4494   DecodeStatus S = MCDisassembler::Success;
4495 
4496   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4497   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4498 
4499   if (Rn == ARM::SP) S = MCDisassembler::SoftFail;
4500   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4501     return MCDisassembler::Fail;
4502   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
4503     return MCDisassembler::Fail;
4504   return S;
4505 }
4506 
4507 static DecodeStatus
4508 DecodeThumb2BCCInstruction(MCInst &Inst, unsigned Insn,
4509                            uint64_t Address, const void *Decoder) {
4510   DecodeStatus S = MCDisassembler::Success;
4511 
4512   unsigned pred = fieldFromInstruction(Insn, 22, 4);
4513   if (pred == 0xE || pred == 0xF) {
4514     unsigned opc = fieldFromInstruction(Insn, 4, 28);
4515     switch (opc) {
4516       default:
4517         return MCDisassembler::Fail;
4518       case 0xf3bf8f4:
4519         Inst.setOpcode(ARM::t2DSB);
4520         break;
4521       case 0xf3bf8f5:
4522         Inst.setOpcode(ARM::t2DMB);
4523         break;
4524       case 0xf3bf8f6:
4525         Inst.setOpcode(ARM::t2ISB);
4526         break;
4527     }
4528 
4529     unsigned imm = fieldFromInstruction(Insn, 0, 4);
4530     return DecodeMemBarrierOption(Inst, imm, Address, Decoder);
4531   }
4532 
4533   unsigned brtarget = fieldFromInstruction(Insn, 0, 11) << 1;
4534   brtarget |= fieldFromInstruction(Insn, 11, 1) << 19;
4535   brtarget |= fieldFromInstruction(Insn, 13, 1) << 18;
4536   brtarget |= fieldFromInstruction(Insn, 16, 6) << 12;
4537   brtarget |= fieldFromInstruction(Insn, 26, 1) << 20;
4538 
4539   if (!Check(S, DecodeT2BROperand(Inst, brtarget, Address, Decoder)))
4540     return MCDisassembler::Fail;
4541   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4542     return MCDisassembler::Fail;
4543 
4544   return S;
4545 }
4546 
4547 // Decode a shifted immediate operand.  These basically consist
4548 // of an 8-bit value, and a 4-bit directive that specifies either
4549 // a splat operation or a rotation.
4550 static DecodeStatus DecodeT2SOImm(MCInst &Inst, unsigned Val,
4551                           uint64_t Address, const void *Decoder) {
4552   unsigned ctrl = fieldFromInstruction(Val, 10, 2);
4553   if (ctrl == 0) {
4554     unsigned byte = fieldFromInstruction(Val, 8, 2);
4555     unsigned imm = fieldFromInstruction(Val, 0, 8);
4556     switch (byte) {
4557       case 0:
4558         Inst.addOperand(MCOperand::createImm(imm));
4559         break;
4560       case 1:
4561         Inst.addOperand(MCOperand::createImm((imm << 16) | imm));
4562         break;
4563       case 2:
4564         Inst.addOperand(MCOperand::createImm((imm << 24) | (imm << 8)));
4565         break;
4566       case 3:
4567         Inst.addOperand(MCOperand::createImm((imm << 24) | (imm << 16) |
4568                                              (imm << 8)  |  imm));
4569         break;
4570     }
4571   } else {
4572     unsigned unrot = fieldFromInstruction(Val, 0, 7) | 0x80;
4573     unsigned rot = fieldFromInstruction(Val, 7, 5);
4574     unsigned imm = (unrot >> rot) | (unrot << ((32-rot)&31));
4575     Inst.addOperand(MCOperand::createImm(imm));
4576   }
4577 
4578   return MCDisassembler::Success;
4579 }
4580 
4581 static DecodeStatus
4582 DecodeThumbBCCTargetOperand(MCInst &Inst, unsigned Val,
4583                             uint64_t Address, const void *Decoder) {
4584   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<9>(Val<<1) + 4,
4585                                 true, 2, Inst, Decoder))
4586     Inst.addOperand(MCOperand::createImm(SignExtend32<9>(Val << 1)));
4587   return MCDisassembler::Success;
4588 }
4589 
4590 static DecodeStatus DecodeThumbBLTargetOperand(MCInst &Inst, unsigned Val,
4591                                                uint64_t Address,
4592                                                const void *Decoder) {
4593   // Val is passed in as S:J1:J2:imm10:imm11
4594   // Note no trailing zero after imm11.  Also the J1 and J2 values are from
4595   // the encoded instruction.  So here change to I1 and I2 values via:
4596   // I1 = NOT(J1 EOR S);
4597   // I2 = NOT(J2 EOR S);
4598   // and build the imm32 with one trailing zero as documented:
4599   // imm32 = SignExtend(S:I1:I2:imm10:imm11:'0', 32);
4600   unsigned S = (Val >> 23) & 1;
4601   unsigned J1 = (Val >> 22) & 1;
4602   unsigned J2 = (Val >> 21) & 1;
4603   unsigned I1 = !(J1 ^ S);
4604   unsigned I2 = !(J2 ^ S);
4605   unsigned tmp = (Val & ~0x600000) | (I1 << 22) | (I2 << 21);
4606   int imm32 = SignExtend32<25>(tmp << 1);
4607 
4608   if (!tryAddingSymbolicOperand(Address, Address + imm32 + 4,
4609                                 true, 4, Inst, Decoder))
4610     Inst.addOperand(MCOperand::createImm(imm32));
4611   return MCDisassembler::Success;
4612 }
4613 
4614 static DecodeStatus DecodeMemBarrierOption(MCInst &Inst, unsigned Val,
4615                                    uint64_t Address, const void *Decoder) {
4616   if (Val & ~0xf)
4617     return MCDisassembler::Fail;
4618 
4619   Inst.addOperand(MCOperand::createImm(Val));
4620   return MCDisassembler::Success;
4621 }
4622 
4623 static DecodeStatus DecodeInstSyncBarrierOption(MCInst &Inst, unsigned Val,
4624                                         uint64_t Address, const void *Decoder) {
4625   if (Val & ~0xf)
4626     return MCDisassembler::Fail;
4627 
4628   Inst.addOperand(MCOperand::createImm(Val));
4629   return MCDisassembler::Success;
4630 }
4631 
4632 static DecodeStatus DecodeMSRMask(MCInst &Inst, unsigned Val,
4633                           uint64_t Address, const void *Decoder) {
4634   DecodeStatus S = MCDisassembler::Success;
4635   const FeatureBitset &FeatureBits =
4636     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4637 
4638   if (FeatureBits[ARM::FeatureMClass]) {
4639     unsigned ValLow = Val & 0xff;
4640 
4641     // Validate the SYSm value first.
4642     switch (ValLow) {
4643     case  0: // apsr
4644     case  1: // iapsr
4645     case  2: // eapsr
4646     case  3: // xpsr
4647     case  5: // ipsr
4648     case  6: // epsr
4649     case  7: // iepsr
4650     case  8: // msp
4651     case  9: // psp
4652     case 16: // primask
4653     case 20: // control
4654       break;
4655     case 17: // basepri
4656     case 18: // basepri_max
4657     case 19: // faultmask
4658       if (!(FeatureBits[ARM::HasV7Ops]))
4659         // Values basepri, basepri_max and faultmask are only valid for v7m.
4660         return MCDisassembler::Fail;
4661       break;
4662     case 0x8a: // msplim_ns
4663     case 0x8b: // psplim_ns
4664     case 0x91: // basepri_ns
4665     case 0x93: // faultmask_ns
4666       if (!(FeatureBits[ARM::HasV8MMainlineOps]))
4667         return MCDisassembler::Fail;
4668       LLVM_FALLTHROUGH;
4669     case 10:   // msplim
4670     case 11:   // psplim
4671     case 0x88: // msp_ns
4672     case 0x89: // psp_ns
4673     case 0x90: // primask_ns
4674     case 0x94: // control_ns
4675     case 0x98: // sp_ns
4676       if (!(FeatureBits[ARM::Feature8MSecExt]))
4677         return MCDisassembler::Fail;
4678       break;
4679     default:
4680       // Architecturally defined as unpredictable
4681       S = MCDisassembler::SoftFail;
4682       break;
4683     }
4684 
4685     if (Inst.getOpcode() == ARM::t2MSR_M) {
4686       unsigned Mask = fieldFromInstruction(Val, 10, 2);
4687       if (!(FeatureBits[ARM::HasV7Ops])) {
4688         // The ARMv6-M MSR bits {11-10} can be only 0b10, other values are
4689         // unpredictable.
4690         if (Mask != 2)
4691           S = MCDisassembler::SoftFail;
4692       }
4693       else {
4694         // The ARMv7-M architecture stores an additional 2-bit mask value in
4695         // MSR bits {11-10}. The mask is used only with apsr, iapsr, eapsr and
4696         // xpsr, it has to be 0b10 in other cases. Bit mask{1} indicates if
4697         // the NZCVQ bits should be moved by the instruction. Bit mask{0}
4698         // indicates the move for the GE{3:0} bits, the mask{0} bit can be set
4699         // only if the processor includes the DSP extension.
4700         if (Mask == 0 || (Mask != 2 && ValLow > 3) ||
4701             (!(FeatureBits[ARM::FeatureDSP]) && (Mask & 1)))
4702           S = MCDisassembler::SoftFail;
4703       }
4704     }
4705   } else {
4706     // A/R class
4707     if (Val == 0)
4708       return MCDisassembler::Fail;
4709   }
4710   Inst.addOperand(MCOperand::createImm(Val));
4711   return S;
4712 }
4713 
4714 static DecodeStatus DecodeBankedReg(MCInst &Inst, unsigned Val,
4715                                     uint64_t Address, const void *Decoder) {
4716   unsigned R = fieldFromInstruction(Val, 5, 1);
4717   unsigned SysM = fieldFromInstruction(Val, 0, 5);
4718 
4719   // The table of encodings for these banked registers comes from B9.2.3 of the
4720   // ARM ARM. There are patterns, but nothing regular enough to make this logic
4721   // neater. So by fiat, these values are UNPREDICTABLE:
4722   if (!ARMBankedReg::lookupBankedRegByEncoding((R << 5) | SysM))
4723     return MCDisassembler::Fail;
4724 
4725   Inst.addOperand(MCOperand::createImm(Val));
4726   return MCDisassembler::Success;
4727 }
4728 
4729 static DecodeStatus DecodeDoubleRegLoad(MCInst &Inst, unsigned Insn,
4730                                         uint64_t Address, const void *Decoder) {
4731   DecodeStatus S = MCDisassembler::Success;
4732 
4733   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4734   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4735   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4736 
4737   if (Rn == 0xF)
4738     S = MCDisassembler::SoftFail;
4739 
4740   if (!Check(S, DecodeGPRPairRegisterClass(Inst, Rt, Address, Decoder)))
4741     return MCDisassembler::Fail;
4742   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4743     return MCDisassembler::Fail;
4744   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4745     return MCDisassembler::Fail;
4746 
4747   return S;
4748 }
4749 
4750 static DecodeStatus DecodeDoubleRegStore(MCInst &Inst, unsigned Insn,
4751                                          uint64_t Address,
4752                                          const void *Decoder) {
4753   DecodeStatus S = MCDisassembler::Success;
4754 
4755   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4756   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
4757   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4758   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4759 
4760   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
4761     return MCDisassembler::Fail;
4762 
4763   if (Rn == 0xF || Rd == Rn || Rd == Rt || Rd == Rt+1)
4764     S = MCDisassembler::SoftFail;
4765 
4766   if (!Check(S, DecodeGPRPairRegisterClass(Inst, Rt, Address, Decoder)))
4767     return MCDisassembler::Fail;
4768   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4769     return MCDisassembler::Fail;
4770   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4771     return MCDisassembler::Fail;
4772 
4773   return S;
4774 }
4775 
4776 static DecodeStatus DecodeLDRPreImm(MCInst &Inst, unsigned Insn,
4777                             uint64_t Address, const void *Decoder) {
4778   DecodeStatus S = MCDisassembler::Success;
4779 
4780   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4781   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4782   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4783   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4784   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4785   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4786 
4787   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4788 
4789   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4790     return MCDisassembler::Fail;
4791   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4792     return MCDisassembler::Fail;
4793   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
4794     return MCDisassembler::Fail;
4795   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4796     return MCDisassembler::Fail;
4797 
4798   return S;
4799 }
4800 
4801 static DecodeStatus DecodeLDRPreReg(MCInst &Inst, unsigned Insn,
4802                             uint64_t Address, const void *Decoder) {
4803   DecodeStatus S = MCDisassembler::Success;
4804 
4805   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4806   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4807   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4808   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4809   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4810   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4811   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4812 
4813   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4814   if (Rm == 0xF) S = MCDisassembler::SoftFail;
4815 
4816   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4817     return MCDisassembler::Fail;
4818   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4819     return MCDisassembler::Fail;
4820   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
4821     return MCDisassembler::Fail;
4822   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4823     return MCDisassembler::Fail;
4824 
4825   return S;
4826 }
4827 
4828 static DecodeStatus DecodeSTRPreImm(MCInst &Inst, unsigned Insn,
4829                             uint64_t Address, const void *Decoder) {
4830   DecodeStatus S = MCDisassembler::Success;
4831 
4832   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4833   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4834   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4835   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4836   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4837   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4838 
4839   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4840 
4841   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4842     return MCDisassembler::Fail;
4843   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4844     return MCDisassembler::Fail;
4845   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
4846     return MCDisassembler::Fail;
4847   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4848     return MCDisassembler::Fail;
4849 
4850   return S;
4851 }
4852 
4853 static DecodeStatus DecodeSTRPreReg(MCInst &Inst, unsigned Insn,
4854                             uint64_t Address, const void *Decoder) {
4855   DecodeStatus S = MCDisassembler::Success;
4856 
4857   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4858   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4859   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4860   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4861   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4862   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4863 
4864   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4865 
4866   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4867     return MCDisassembler::Fail;
4868   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4869     return MCDisassembler::Fail;
4870   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
4871     return MCDisassembler::Fail;
4872   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4873     return MCDisassembler::Fail;
4874 
4875   return S;
4876 }
4877 
4878 static DecodeStatus DecodeVLD1LN(MCInst &Inst, unsigned Insn,
4879                          uint64_t Address, const void *Decoder) {
4880   DecodeStatus S = MCDisassembler::Success;
4881 
4882   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4883   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4884   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4885   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4886   unsigned size = fieldFromInstruction(Insn, 10, 2);
4887 
4888   unsigned align = 0;
4889   unsigned index = 0;
4890   switch (size) {
4891     default:
4892       return MCDisassembler::Fail;
4893     case 0:
4894       if (fieldFromInstruction(Insn, 4, 1))
4895         return MCDisassembler::Fail; // UNDEFINED
4896       index = fieldFromInstruction(Insn, 5, 3);
4897       break;
4898     case 1:
4899       if (fieldFromInstruction(Insn, 5, 1))
4900         return MCDisassembler::Fail; // UNDEFINED
4901       index = fieldFromInstruction(Insn, 6, 2);
4902       if (fieldFromInstruction(Insn, 4, 1))
4903         align = 2;
4904       break;
4905     case 2:
4906       if (fieldFromInstruction(Insn, 6, 1))
4907         return MCDisassembler::Fail; // UNDEFINED
4908       index = fieldFromInstruction(Insn, 7, 1);
4909 
4910       switch (fieldFromInstruction(Insn, 4, 2)) {
4911         case 0 :
4912           align = 0; break;
4913         case 3:
4914           align = 4; break;
4915         default:
4916           return MCDisassembler::Fail;
4917       }
4918       break;
4919   }
4920 
4921   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4922     return MCDisassembler::Fail;
4923   if (Rm != 0xF) { // Writeback
4924     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4925       return MCDisassembler::Fail;
4926   }
4927   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4928     return MCDisassembler::Fail;
4929   Inst.addOperand(MCOperand::createImm(align));
4930   if (Rm != 0xF) {
4931     if (Rm != 0xD) {
4932       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4933         return MCDisassembler::Fail;
4934     } else
4935       Inst.addOperand(MCOperand::createReg(0));
4936   }
4937 
4938   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4939     return MCDisassembler::Fail;
4940   Inst.addOperand(MCOperand::createImm(index));
4941 
4942   return S;
4943 }
4944 
4945 static DecodeStatus DecodeVST1LN(MCInst &Inst, unsigned Insn,
4946                          uint64_t Address, const void *Decoder) {
4947   DecodeStatus S = MCDisassembler::Success;
4948 
4949   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4950   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4951   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4952   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4953   unsigned size = fieldFromInstruction(Insn, 10, 2);
4954 
4955   unsigned align = 0;
4956   unsigned index = 0;
4957   switch (size) {
4958     default:
4959       return MCDisassembler::Fail;
4960     case 0:
4961       if (fieldFromInstruction(Insn, 4, 1))
4962         return MCDisassembler::Fail; // UNDEFINED
4963       index = fieldFromInstruction(Insn, 5, 3);
4964       break;
4965     case 1:
4966       if (fieldFromInstruction(Insn, 5, 1))
4967         return MCDisassembler::Fail; // UNDEFINED
4968       index = fieldFromInstruction(Insn, 6, 2);
4969       if (fieldFromInstruction(Insn, 4, 1))
4970         align = 2;
4971       break;
4972     case 2:
4973       if (fieldFromInstruction(Insn, 6, 1))
4974         return MCDisassembler::Fail; // UNDEFINED
4975       index = fieldFromInstruction(Insn, 7, 1);
4976 
4977       switch (fieldFromInstruction(Insn, 4, 2)) {
4978         case 0:
4979           align = 0; break;
4980         case 3:
4981           align = 4; break;
4982         default:
4983           return MCDisassembler::Fail;
4984       }
4985       break;
4986   }
4987 
4988   if (Rm != 0xF) { // Writeback
4989     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4990     return MCDisassembler::Fail;
4991   }
4992   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4993     return MCDisassembler::Fail;
4994   Inst.addOperand(MCOperand::createImm(align));
4995   if (Rm != 0xF) {
4996     if (Rm != 0xD) {
4997       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4998     return MCDisassembler::Fail;
4999     } else
5000       Inst.addOperand(MCOperand::createReg(0));
5001   }
5002 
5003   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5004     return MCDisassembler::Fail;
5005   Inst.addOperand(MCOperand::createImm(index));
5006 
5007   return S;
5008 }
5009 
5010 static DecodeStatus DecodeVLD2LN(MCInst &Inst, unsigned Insn,
5011                          uint64_t Address, const void *Decoder) {
5012   DecodeStatus S = MCDisassembler::Success;
5013 
5014   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5015   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5016   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5017   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5018   unsigned size = fieldFromInstruction(Insn, 10, 2);
5019 
5020   unsigned align = 0;
5021   unsigned index = 0;
5022   unsigned inc = 1;
5023   switch (size) {
5024     default:
5025       return MCDisassembler::Fail;
5026     case 0:
5027       index = fieldFromInstruction(Insn, 5, 3);
5028       if (fieldFromInstruction(Insn, 4, 1))
5029         align = 2;
5030       break;
5031     case 1:
5032       index = fieldFromInstruction(Insn, 6, 2);
5033       if (fieldFromInstruction(Insn, 4, 1))
5034         align = 4;
5035       if (fieldFromInstruction(Insn, 5, 1))
5036         inc = 2;
5037       break;
5038     case 2:
5039       if (fieldFromInstruction(Insn, 5, 1))
5040         return MCDisassembler::Fail; // UNDEFINED
5041       index = fieldFromInstruction(Insn, 7, 1);
5042       if (fieldFromInstruction(Insn, 4, 1) != 0)
5043         align = 8;
5044       if (fieldFromInstruction(Insn, 6, 1))
5045         inc = 2;
5046       break;
5047   }
5048 
5049   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5050     return MCDisassembler::Fail;
5051   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5052     return MCDisassembler::Fail;
5053   if (Rm != 0xF) { // Writeback
5054     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5055       return MCDisassembler::Fail;
5056   }
5057   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5058     return MCDisassembler::Fail;
5059   Inst.addOperand(MCOperand::createImm(align));
5060   if (Rm != 0xF) {
5061     if (Rm != 0xD) {
5062       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5063         return MCDisassembler::Fail;
5064     } else
5065       Inst.addOperand(MCOperand::createReg(0));
5066   }
5067 
5068   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5069     return MCDisassembler::Fail;
5070   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5071     return MCDisassembler::Fail;
5072   Inst.addOperand(MCOperand::createImm(index));
5073 
5074   return S;
5075 }
5076 
5077 static DecodeStatus DecodeVST2LN(MCInst &Inst, unsigned Insn,
5078                          uint64_t Address, const void *Decoder) {
5079   DecodeStatus S = MCDisassembler::Success;
5080 
5081   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5082   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5083   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5084   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5085   unsigned size = fieldFromInstruction(Insn, 10, 2);
5086 
5087   unsigned align = 0;
5088   unsigned index = 0;
5089   unsigned inc = 1;
5090   switch (size) {
5091     default:
5092       return MCDisassembler::Fail;
5093     case 0:
5094       index = fieldFromInstruction(Insn, 5, 3);
5095       if (fieldFromInstruction(Insn, 4, 1))
5096         align = 2;
5097       break;
5098     case 1:
5099       index = fieldFromInstruction(Insn, 6, 2);
5100       if (fieldFromInstruction(Insn, 4, 1))
5101         align = 4;
5102       if (fieldFromInstruction(Insn, 5, 1))
5103         inc = 2;
5104       break;
5105     case 2:
5106       if (fieldFromInstruction(Insn, 5, 1))
5107         return MCDisassembler::Fail; // UNDEFINED
5108       index = fieldFromInstruction(Insn, 7, 1);
5109       if (fieldFromInstruction(Insn, 4, 1) != 0)
5110         align = 8;
5111       if (fieldFromInstruction(Insn, 6, 1))
5112         inc = 2;
5113       break;
5114   }
5115 
5116   if (Rm != 0xF) { // Writeback
5117     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5118       return MCDisassembler::Fail;
5119   }
5120   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5121     return MCDisassembler::Fail;
5122   Inst.addOperand(MCOperand::createImm(align));
5123   if (Rm != 0xF) {
5124     if (Rm != 0xD) {
5125       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5126         return MCDisassembler::Fail;
5127     } else
5128       Inst.addOperand(MCOperand::createReg(0));
5129   }
5130 
5131   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5132     return MCDisassembler::Fail;
5133   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5134     return MCDisassembler::Fail;
5135   Inst.addOperand(MCOperand::createImm(index));
5136 
5137   return S;
5138 }
5139 
5140 static DecodeStatus DecodeVLD3LN(MCInst &Inst, unsigned Insn,
5141                          uint64_t Address, const void *Decoder) {
5142   DecodeStatus S = MCDisassembler::Success;
5143 
5144   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5145   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5146   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5147   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5148   unsigned size = fieldFromInstruction(Insn, 10, 2);
5149 
5150   unsigned align = 0;
5151   unsigned index = 0;
5152   unsigned inc = 1;
5153   switch (size) {
5154     default:
5155       return MCDisassembler::Fail;
5156     case 0:
5157       if (fieldFromInstruction(Insn, 4, 1))
5158         return MCDisassembler::Fail; // UNDEFINED
5159       index = fieldFromInstruction(Insn, 5, 3);
5160       break;
5161     case 1:
5162       if (fieldFromInstruction(Insn, 4, 1))
5163         return MCDisassembler::Fail; // UNDEFINED
5164       index = fieldFromInstruction(Insn, 6, 2);
5165       if (fieldFromInstruction(Insn, 5, 1))
5166         inc = 2;
5167       break;
5168     case 2:
5169       if (fieldFromInstruction(Insn, 4, 2))
5170         return MCDisassembler::Fail; // UNDEFINED
5171       index = fieldFromInstruction(Insn, 7, 1);
5172       if (fieldFromInstruction(Insn, 6, 1))
5173         inc = 2;
5174       break;
5175   }
5176 
5177   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5178     return MCDisassembler::Fail;
5179   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5180     return MCDisassembler::Fail;
5181   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5182     return MCDisassembler::Fail;
5183 
5184   if (Rm != 0xF) { // Writeback
5185     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5186     return MCDisassembler::Fail;
5187   }
5188   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5189     return MCDisassembler::Fail;
5190   Inst.addOperand(MCOperand::createImm(align));
5191   if (Rm != 0xF) {
5192     if (Rm != 0xD) {
5193       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5194     return MCDisassembler::Fail;
5195     } else
5196       Inst.addOperand(MCOperand::createReg(0));
5197   }
5198 
5199   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5200     return MCDisassembler::Fail;
5201   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5202     return MCDisassembler::Fail;
5203   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5204     return MCDisassembler::Fail;
5205   Inst.addOperand(MCOperand::createImm(index));
5206 
5207   return S;
5208 }
5209 
5210 static DecodeStatus DecodeVST3LN(MCInst &Inst, unsigned Insn,
5211                          uint64_t Address, const void *Decoder) {
5212   DecodeStatus S = MCDisassembler::Success;
5213 
5214   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5215   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5216   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5217   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5218   unsigned size = fieldFromInstruction(Insn, 10, 2);
5219 
5220   unsigned align = 0;
5221   unsigned index = 0;
5222   unsigned inc = 1;
5223   switch (size) {
5224     default:
5225       return MCDisassembler::Fail;
5226     case 0:
5227       if (fieldFromInstruction(Insn, 4, 1))
5228         return MCDisassembler::Fail; // UNDEFINED
5229       index = fieldFromInstruction(Insn, 5, 3);
5230       break;
5231     case 1:
5232       if (fieldFromInstruction(Insn, 4, 1))
5233         return MCDisassembler::Fail; // UNDEFINED
5234       index = fieldFromInstruction(Insn, 6, 2);
5235       if (fieldFromInstruction(Insn, 5, 1))
5236         inc = 2;
5237       break;
5238     case 2:
5239       if (fieldFromInstruction(Insn, 4, 2))
5240         return MCDisassembler::Fail; // UNDEFINED
5241       index = fieldFromInstruction(Insn, 7, 1);
5242       if (fieldFromInstruction(Insn, 6, 1))
5243         inc = 2;
5244       break;
5245   }
5246 
5247   if (Rm != 0xF) { // Writeback
5248     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5249     return MCDisassembler::Fail;
5250   }
5251   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5252     return MCDisassembler::Fail;
5253   Inst.addOperand(MCOperand::createImm(align));
5254   if (Rm != 0xF) {
5255     if (Rm != 0xD) {
5256       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5257     return MCDisassembler::Fail;
5258     } else
5259       Inst.addOperand(MCOperand::createReg(0));
5260   }
5261 
5262   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5263     return MCDisassembler::Fail;
5264   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5265     return MCDisassembler::Fail;
5266   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5267     return MCDisassembler::Fail;
5268   Inst.addOperand(MCOperand::createImm(index));
5269 
5270   return S;
5271 }
5272 
5273 static DecodeStatus DecodeVLD4LN(MCInst &Inst, unsigned Insn,
5274                          uint64_t Address, const void *Decoder) {
5275   DecodeStatus S = MCDisassembler::Success;
5276 
5277   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5278   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5279   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5280   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5281   unsigned size = fieldFromInstruction(Insn, 10, 2);
5282 
5283   unsigned align = 0;
5284   unsigned index = 0;
5285   unsigned inc = 1;
5286   switch (size) {
5287     default:
5288       return MCDisassembler::Fail;
5289     case 0:
5290       if (fieldFromInstruction(Insn, 4, 1))
5291         align = 4;
5292       index = fieldFromInstruction(Insn, 5, 3);
5293       break;
5294     case 1:
5295       if (fieldFromInstruction(Insn, 4, 1))
5296         align = 8;
5297       index = fieldFromInstruction(Insn, 6, 2);
5298       if (fieldFromInstruction(Insn, 5, 1))
5299         inc = 2;
5300       break;
5301     case 2:
5302       switch (fieldFromInstruction(Insn, 4, 2)) {
5303         case 0:
5304           align = 0; break;
5305         case 3:
5306           return MCDisassembler::Fail;
5307         default:
5308           align = 4 << fieldFromInstruction(Insn, 4, 2); break;
5309       }
5310 
5311       index = fieldFromInstruction(Insn, 7, 1);
5312       if (fieldFromInstruction(Insn, 6, 1))
5313         inc = 2;
5314       break;
5315   }
5316 
5317   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5318     return MCDisassembler::Fail;
5319   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5320     return MCDisassembler::Fail;
5321   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5322     return MCDisassembler::Fail;
5323   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5324     return MCDisassembler::Fail;
5325 
5326   if (Rm != 0xF) { // Writeback
5327     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5328       return MCDisassembler::Fail;
5329   }
5330   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5331     return MCDisassembler::Fail;
5332   Inst.addOperand(MCOperand::createImm(align));
5333   if (Rm != 0xF) {
5334     if (Rm != 0xD) {
5335       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5336         return MCDisassembler::Fail;
5337     } else
5338       Inst.addOperand(MCOperand::createReg(0));
5339   }
5340 
5341   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5342     return MCDisassembler::Fail;
5343   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5344     return MCDisassembler::Fail;
5345   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5346     return MCDisassembler::Fail;
5347   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5348     return MCDisassembler::Fail;
5349   Inst.addOperand(MCOperand::createImm(index));
5350 
5351   return S;
5352 }
5353 
5354 static DecodeStatus DecodeVST4LN(MCInst &Inst, unsigned Insn,
5355                          uint64_t Address, const void *Decoder) {
5356   DecodeStatus S = MCDisassembler::Success;
5357 
5358   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5359   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5360   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5361   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5362   unsigned size = fieldFromInstruction(Insn, 10, 2);
5363 
5364   unsigned align = 0;
5365   unsigned index = 0;
5366   unsigned inc = 1;
5367   switch (size) {
5368     default:
5369       return MCDisassembler::Fail;
5370     case 0:
5371       if (fieldFromInstruction(Insn, 4, 1))
5372         align = 4;
5373       index = fieldFromInstruction(Insn, 5, 3);
5374       break;
5375     case 1:
5376       if (fieldFromInstruction(Insn, 4, 1))
5377         align = 8;
5378       index = fieldFromInstruction(Insn, 6, 2);
5379       if (fieldFromInstruction(Insn, 5, 1))
5380         inc = 2;
5381       break;
5382     case 2:
5383       switch (fieldFromInstruction(Insn, 4, 2)) {
5384         case 0:
5385           align = 0; break;
5386         case 3:
5387           return MCDisassembler::Fail;
5388         default:
5389           align = 4 << fieldFromInstruction(Insn, 4, 2); break;
5390       }
5391 
5392       index = fieldFromInstruction(Insn, 7, 1);
5393       if (fieldFromInstruction(Insn, 6, 1))
5394         inc = 2;
5395       break;
5396   }
5397 
5398   if (Rm != 0xF) { // Writeback
5399     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5400     return MCDisassembler::Fail;
5401   }
5402   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5403     return MCDisassembler::Fail;
5404   Inst.addOperand(MCOperand::createImm(align));
5405   if (Rm != 0xF) {
5406     if (Rm != 0xD) {
5407       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5408     return MCDisassembler::Fail;
5409     } else
5410       Inst.addOperand(MCOperand::createReg(0));
5411   }
5412 
5413   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5414     return MCDisassembler::Fail;
5415   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5416     return MCDisassembler::Fail;
5417   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5418     return MCDisassembler::Fail;
5419   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5420     return MCDisassembler::Fail;
5421   Inst.addOperand(MCOperand::createImm(index));
5422 
5423   return S;
5424 }
5425 
5426 static DecodeStatus DecodeVMOVSRR(MCInst &Inst, unsigned Insn,
5427                                   uint64_t Address, const void *Decoder) {
5428   DecodeStatus S = MCDisassembler::Success;
5429   unsigned Rt  = fieldFromInstruction(Insn, 12, 4);
5430   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
5431   unsigned Rm  = fieldFromInstruction(Insn,  5, 1);
5432   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5433   Rm |= fieldFromInstruction(Insn, 0, 4) << 1;
5434 
5435   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
5436     S = MCDisassembler::SoftFail;
5437 
5438   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
5439     return MCDisassembler::Fail;
5440   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
5441     return MCDisassembler::Fail;
5442   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
5443     return MCDisassembler::Fail;
5444   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
5445     return MCDisassembler::Fail;
5446   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5447     return MCDisassembler::Fail;
5448 
5449   return S;
5450 }
5451 
5452 static DecodeStatus DecodeVMOVRRS(MCInst &Inst, unsigned Insn,
5453                                   uint64_t Address, const void *Decoder) {
5454   DecodeStatus S = MCDisassembler::Success;
5455   unsigned Rt  = fieldFromInstruction(Insn, 12, 4);
5456   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
5457   unsigned Rm  = fieldFromInstruction(Insn,  5, 1);
5458   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5459   Rm |= fieldFromInstruction(Insn, 0, 4) << 1;
5460 
5461   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
5462     S = MCDisassembler::SoftFail;
5463 
5464   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
5465     return MCDisassembler::Fail;
5466   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
5467     return MCDisassembler::Fail;
5468   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
5469     return MCDisassembler::Fail;
5470   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
5471     return MCDisassembler::Fail;
5472   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5473     return MCDisassembler::Fail;
5474 
5475   return S;
5476 }
5477 
5478 static DecodeStatus DecodeIT(MCInst &Inst, unsigned Insn,
5479                              uint64_t Address, const void *Decoder) {
5480   DecodeStatus S = MCDisassembler::Success;
5481   unsigned pred = fieldFromInstruction(Insn, 4, 4);
5482   unsigned mask = fieldFromInstruction(Insn, 0, 4);
5483 
5484   if (pred == 0xF) {
5485     pred = 0xE;
5486     S = MCDisassembler::SoftFail;
5487   }
5488 
5489   if (mask == 0x0)
5490     return MCDisassembler::Fail;
5491 
5492   // IT masks are encoded as a sequence of replacement low-order bits
5493   // for the condition code. So if the low bit of the starting
5494   // condition code is 1, then we have to flip all the bits above the
5495   // terminating bit (which is the lowest 1 bit).
5496   if (pred & 1) {
5497     unsigned LowBit = mask & -mask;
5498     unsigned BitsAboveLowBit = 0xF & (-LowBit << 1);
5499     mask ^= BitsAboveLowBit;
5500   }
5501 
5502   Inst.addOperand(MCOperand::createImm(pred));
5503   Inst.addOperand(MCOperand::createImm(mask));
5504   return S;
5505 }
5506 
5507 static DecodeStatus
5508 DecodeT2LDRDPreInstruction(MCInst &Inst, unsigned Insn,
5509                            uint64_t Address, const void *Decoder) {
5510   DecodeStatus S = MCDisassembler::Success;
5511 
5512   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5513   unsigned Rt2 = fieldFromInstruction(Insn, 8, 4);
5514   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5515   unsigned addr = fieldFromInstruction(Insn, 0, 8);
5516   unsigned W = fieldFromInstruction(Insn, 21, 1);
5517   unsigned U = fieldFromInstruction(Insn, 23, 1);
5518   unsigned P = fieldFromInstruction(Insn, 24, 1);
5519   bool writeback = (W == 1) | (P == 0);
5520 
5521   addr |= (U << 8) | (Rn << 9);
5522 
5523   if (writeback && (Rn == Rt || Rn == Rt2))
5524     Check(S, MCDisassembler::SoftFail);
5525   if (Rt == Rt2)
5526     Check(S, MCDisassembler::SoftFail);
5527 
5528   // Rt
5529   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
5530     return MCDisassembler::Fail;
5531   // Rt2
5532   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
5533     return MCDisassembler::Fail;
5534   // Writeback operand
5535   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
5536     return MCDisassembler::Fail;
5537   // addr
5538   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
5539     return MCDisassembler::Fail;
5540 
5541   return S;
5542 }
5543 
5544 static DecodeStatus
5545 DecodeT2STRDPreInstruction(MCInst &Inst, unsigned Insn,
5546                            uint64_t Address, const void *Decoder) {
5547   DecodeStatus S = MCDisassembler::Success;
5548 
5549   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5550   unsigned Rt2 = fieldFromInstruction(Insn, 8, 4);
5551   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5552   unsigned addr = fieldFromInstruction(Insn, 0, 8);
5553   unsigned W = fieldFromInstruction(Insn, 21, 1);
5554   unsigned U = fieldFromInstruction(Insn, 23, 1);
5555   unsigned P = fieldFromInstruction(Insn, 24, 1);
5556   bool writeback = (W == 1) | (P == 0);
5557 
5558   addr |= (U << 8) | (Rn << 9);
5559 
5560   if (writeback && (Rn == Rt || Rn == Rt2))
5561     Check(S, MCDisassembler::SoftFail);
5562 
5563   // Writeback operand
5564   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
5565     return MCDisassembler::Fail;
5566   // Rt
5567   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
5568     return MCDisassembler::Fail;
5569   // Rt2
5570   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
5571     return MCDisassembler::Fail;
5572   // addr
5573   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
5574     return MCDisassembler::Fail;
5575 
5576   return S;
5577 }
5578 
5579 static DecodeStatus DecodeT2Adr(MCInst &Inst, uint32_t Insn,
5580                                 uint64_t Address, const void *Decoder) {
5581   unsigned sign1 = fieldFromInstruction(Insn, 21, 1);
5582   unsigned sign2 = fieldFromInstruction(Insn, 23, 1);
5583   if (sign1 != sign2) return MCDisassembler::Fail;
5584 
5585   unsigned Val = fieldFromInstruction(Insn, 0, 8);
5586   Val |= fieldFromInstruction(Insn, 12, 3) << 8;
5587   Val |= fieldFromInstruction(Insn, 26, 1) << 11;
5588   Val |= sign1 << 12;
5589   Inst.addOperand(MCOperand::createImm(SignExtend32<13>(Val)));
5590 
5591   return MCDisassembler::Success;
5592 }
5593 
5594 static DecodeStatus DecodeT2ShifterImmOperand(MCInst &Inst, uint32_t Val,
5595                                               uint64_t Address,
5596                                               const void *Decoder) {
5597   DecodeStatus S = MCDisassembler::Success;
5598 
5599   // Shift of "asr #32" is not allowed in Thumb2 mode.
5600   if (Val == 0x20) S = MCDisassembler::Fail;
5601   Inst.addOperand(MCOperand::createImm(Val));
5602   return S;
5603 }
5604 
5605 static DecodeStatus DecodeSwap(MCInst &Inst, unsigned Insn,
5606                                uint64_t Address, const void *Decoder) {
5607   unsigned Rt   = fieldFromInstruction(Insn, 12, 4);
5608   unsigned Rt2  = fieldFromInstruction(Insn, 0,  4);
5609   unsigned Rn   = fieldFromInstruction(Insn, 16, 4);
5610   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5611 
5612   if (pred == 0xF)
5613     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
5614 
5615   DecodeStatus S = MCDisassembler::Success;
5616 
5617   if (Rt == Rn || Rn == Rt2)
5618     S = MCDisassembler::SoftFail;
5619 
5620   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5621     return MCDisassembler::Fail;
5622   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5623     return MCDisassembler::Fail;
5624   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
5625     return MCDisassembler::Fail;
5626   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5627     return MCDisassembler::Fail;
5628 
5629   return S;
5630 }
5631 
5632 static DecodeStatus DecodeVCVTD(MCInst &Inst, unsigned Insn,
5633                                 uint64_t Address, const void *Decoder) {
5634   const FeatureBitset &featureBits =
5635       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5636   bool hasFullFP16 = featureBits[ARM::FeatureFullFP16];
5637 
5638   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5639   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5640   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5641   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5642   unsigned imm = fieldFromInstruction(Insn, 16, 6);
5643   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
5644   unsigned op = fieldFromInstruction(Insn, 5, 1);
5645 
5646   DecodeStatus S = MCDisassembler::Success;
5647 
5648   // If the top 3 bits of imm are clear, this is a VMOV (immediate)
5649   if (!(imm & 0x38)) {
5650     if (cmode == 0xF) {
5651       if (op == 1) return MCDisassembler::Fail;
5652       Inst.setOpcode(ARM::VMOVv2f32);
5653     }
5654     if (hasFullFP16) {
5655       if (cmode == 0xE) {
5656         if (op == 1) {
5657           Inst.setOpcode(ARM::VMOVv1i64);
5658         } else {
5659           Inst.setOpcode(ARM::VMOVv8i8);
5660         }
5661       }
5662       if (cmode == 0xD) {
5663         if (op == 1) {
5664           Inst.setOpcode(ARM::VMVNv2i32);
5665         } else {
5666           Inst.setOpcode(ARM::VMOVv2i32);
5667         }
5668       }
5669       if (cmode == 0xC) {
5670         if (op == 1) {
5671           Inst.setOpcode(ARM::VMVNv2i32);
5672         } else {
5673           Inst.setOpcode(ARM::VMOVv2i32);
5674         }
5675       }
5676     }
5677     return DecodeNEONModImmInstruction(Inst, Insn, Address, Decoder);
5678   }
5679 
5680   if (!(imm & 0x20)) return MCDisassembler::Fail;
5681 
5682   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
5683     return MCDisassembler::Fail;
5684   if (!Check(S, DecodeDPRRegisterClass(Inst, Vm, Address, Decoder)))
5685     return MCDisassembler::Fail;
5686   Inst.addOperand(MCOperand::createImm(64 - imm));
5687 
5688   return S;
5689 }
5690 
5691 static DecodeStatus DecodeVCVTQ(MCInst &Inst, unsigned Insn,
5692                                 uint64_t Address, const void *Decoder) {
5693   const FeatureBitset &featureBits =
5694       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5695   bool hasFullFP16 = featureBits[ARM::FeatureFullFP16];
5696 
5697   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5698   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5699   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5700   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5701   unsigned imm = fieldFromInstruction(Insn, 16, 6);
5702   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
5703   unsigned op = fieldFromInstruction(Insn, 5, 1);
5704 
5705   DecodeStatus S = MCDisassembler::Success;
5706 
5707   // If the top 3 bits of imm are clear, this is a VMOV (immediate)
5708   if (!(imm & 0x38)) {
5709     if (cmode == 0xF) {
5710       if (op == 1) return MCDisassembler::Fail;
5711       Inst.setOpcode(ARM::VMOVv4f32);
5712     }
5713     if (hasFullFP16) {
5714       if (cmode == 0xE) {
5715         if (op == 1) {
5716           Inst.setOpcode(ARM::VMOVv2i64);
5717         } else {
5718           Inst.setOpcode(ARM::VMOVv16i8);
5719         }
5720       }
5721       if (cmode == 0xD) {
5722         if (op == 1) {
5723           Inst.setOpcode(ARM::VMVNv4i32);
5724         } else {
5725           Inst.setOpcode(ARM::VMOVv4i32);
5726         }
5727       }
5728       if (cmode == 0xC) {
5729         if (op == 1) {
5730           Inst.setOpcode(ARM::VMVNv4i32);
5731         } else {
5732           Inst.setOpcode(ARM::VMOVv4i32);
5733         }
5734       }
5735     }
5736     return DecodeNEONModImmInstruction(Inst, Insn, Address, Decoder);
5737   }
5738 
5739   if (!(imm & 0x20)) return MCDisassembler::Fail;
5740 
5741   if (!Check(S, DecodeQPRRegisterClass(Inst, Vd, Address, Decoder)))
5742     return MCDisassembler::Fail;
5743   if (!Check(S, DecodeQPRRegisterClass(Inst, Vm, Address, Decoder)))
5744     return MCDisassembler::Fail;
5745   Inst.addOperand(MCOperand::createImm(64 - imm));
5746 
5747   return S;
5748 }
5749 
5750 static DecodeStatus DecodeNEONComplexLane64Instruction(MCInst &Inst,
5751                                                        unsigned Insn,
5752                                                        uint64_t Address,
5753                                                        const void *Decoder) {
5754   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5755   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5756   unsigned Vn = (fieldFromInstruction(Insn, 16, 4) << 0);
5757   Vn |= (fieldFromInstruction(Insn, 7, 1) << 4);
5758   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5759   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5760   unsigned q = (fieldFromInstruction(Insn, 6, 1) << 0);
5761   unsigned rotate = (fieldFromInstruction(Insn, 20, 2) << 0);
5762 
5763   DecodeStatus S = MCDisassembler::Success;
5764 
5765   auto DestRegDecoder = q ? DecodeQPRRegisterClass : DecodeDPRRegisterClass;
5766 
5767   if (!Check(S, DestRegDecoder(Inst, Vd, Address, Decoder)))
5768     return MCDisassembler::Fail;
5769   if (!Check(S, DestRegDecoder(Inst, Vd, Address, Decoder)))
5770     return MCDisassembler::Fail;
5771   if (!Check(S, DestRegDecoder(Inst, Vn, Address, Decoder)))
5772     return MCDisassembler::Fail;
5773   if (!Check(S, DecodeDPRRegisterClass(Inst, Vm, Address, Decoder)))
5774     return MCDisassembler::Fail;
5775   // The lane index does not have any bits in the encoding, because it can only
5776   // be 0.
5777   Inst.addOperand(MCOperand::createImm(0));
5778   Inst.addOperand(MCOperand::createImm(rotate));
5779 
5780   return S;
5781 }
5782 
5783 static DecodeStatus DecodeLDR(MCInst &Inst, unsigned Val,
5784                                 uint64_t Address, const void *Decoder) {
5785   DecodeStatus S = MCDisassembler::Success;
5786 
5787   unsigned Rn = fieldFromInstruction(Val, 16, 4);
5788   unsigned Rt = fieldFromInstruction(Val, 12, 4);
5789   unsigned Rm = fieldFromInstruction(Val, 0, 4);
5790   Rm |= (fieldFromInstruction(Val, 23, 1) << 4);
5791   unsigned Cond = fieldFromInstruction(Val, 28, 4);
5792 
5793   if (fieldFromInstruction(Val, 8, 4) != 0 || Rn == Rt)
5794     S = MCDisassembler::SoftFail;
5795 
5796   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5797     return MCDisassembler::Fail;
5798   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
5799     return MCDisassembler::Fail;
5800   if (!Check(S, DecodeAddrMode7Operand(Inst, Rn, Address, Decoder)))
5801     return MCDisassembler::Fail;
5802   if (!Check(S, DecodePostIdxReg(Inst, Rm, Address, Decoder)))
5803     return MCDisassembler::Fail;
5804   if (!Check(S, DecodePredicateOperand(Inst, Cond, Address, Decoder)))
5805     return MCDisassembler::Fail;
5806 
5807   return S;
5808 }
5809 
5810 static DecodeStatus DecoderForMRRC2AndMCRR2(MCInst &Inst, unsigned Val,
5811                                             uint64_t Address, const void *Decoder) {
5812   DecodeStatus S = MCDisassembler::Success;
5813 
5814   unsigned CRm = fieldFromInstruction(Val, 0, 4);
5815   unsigned opc1 = fieldFromInstruction(Val, 4, 4);
5816   unsigned cop = fieldFromInstruction(Val, 8, 4);
5817   unsigned Rt = fieldFromInstruction(Val, 12, 4);
5818   unsigned Rt2 = fieldFromInstruction(Val, 16, 4);
5819 
5820   if ((cop & ~0x1) == 0xa)
5821     return MCDisassembler::Fail;
5822 
5823   if (Rt == Rt2)
5824     S = MCDisassembler::SoftFail;
5825 
5826   // We have to check if the instruction is MRRC2
5827   // or MCRR2 when constructing the operands for
5828   // Inst. Reason is because MRRC2 stores to two
5829   // registers so it's tablegen desc has has two
5830   // outputs whereas MCRR doesn't store to any
5831   // registers so all of it's operands are listed
5832   // as inputs, therefore the operand order for
5833   // MRRC2 needs to be [Rt, Rt2, cop, opc1, CRm]
5834   // and MCRR2 operand order is [cop, opc1, Rt, Rt2, CRm]
5835 
5836   if (Inst.getOpcode() == ARM::MRRC2) {
5837     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5838       return MCDisassembler::Fail;
5839     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5840       return MCDisassembler::Fail;
5841   }
5842   Inst.addOperand(MCOperand::createImm(cop));
5843   Inst.addOperand(MCOperand::createImm(opc1));
5844   if (Inst.getOpcode() == ARM::MCRR2) {
5845     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5846       return MCDisassembler::Fail;
5847     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5848       return MCDisassembler::Fail;
5849   }
5850   Inst.addOperand(MCOperand::createImm(CRm));
5851 
5852   return S;
5853 }
5854 
5855 static DecodeStatus DecodeForVMRSandVMSR(MCInst &Inst, unsigned Val,
5856                                          uint64_t Address,
5857                                          const void *Decoder) {
5858   const FeatureBitset &featureBits =
5859       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5860   DecodeStatus S = MCDisassembler::Success;
5861 
5862   // Add explicit operand for the destination sysreg, for cases where
5863   // we have to model it for code generation purposes.
5864   switch (Inst.getOpcode()) {
5865   case ARM::VMSR_FPSCR_NZCVQC:
5866     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
5867     break;
5868   case ARM::VMSR_P0:
5869     Inst.addOperand(MCOperand::createReg(ARM::VPR));
5870     break;
5871   }
5872 
5873   if (Inst.getOpcode() != ARM::FMSTAT) {
5874     unsigned Rt = fieldFromInstruction(Val, 12, 4);
5875 
5876     if (featureBits[ARM::ModeThumb] && !featureBits[ARM::HasV8Ops]) {
5877       if (Rt == 13 || Rt == 15)
5878         S = MCDisassembler::SoftFail;
5879       Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder));
5880     } else
5881       Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder));
5882   }
5883 
5884   // Add explicit operand for the source sysreg, similarly to above.
5885   switch (Inst.getOpcode()) {
5886   case ARM::VMRS_FPSCR_NZCVQC:
5887     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
5888     break;
5889   case ARM::VMRS_P0:
5890     Inst.addOperand(MCOperand::createReg(ARM::VPR));
5891     break;
5892   }
5893 
5894   if (featureBits[ARM::ModeThumb]) {
5895     Inst.addOperand(MCOperand::createImm(ARMCC::AL));
5896     Inst.addOperand(MCOperand::createReg(0));
5897   } else {
5898     unsigned pred = fieldFromInstruction(Val, 28, 4);
5899     if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5900       return MCDisassembler::Fail;
5901   }
5902 
5903   return S;
5904 }
5905 
5906 template <bool isSigned, bool isNeg, int size>
5907 static DecodeStatus DecodeBFLabelOperand(MCInst &Inst, unsigned Val,
5908                                          uint64_t Address,
5909                                          const void *Decoder) {
5910   DecodeStatus S = MCDisassembler::Success;
5911   if (Val == 0)
5912     S = MCDisassembler::SoftFail;
5913 
5914   uint64_t DecVal;
5915   if (isSigned)
5916     DecVal = SignExtend32<size + 1>(Val << 1);
5917   else
5918     DecVal = (Val << 1);
5919 
5920   if (!tryAddingSymbolicOperand(Address, Address + DecVal + 4, true, 4, Inst,
5921                                 Decoder))
5922     Inst.addOperand(MCOperand::createImm(isNeg ? -DecVal : DecVal));
5923   return S;
5924 }
5925 
5926 static DecodeStatus DecodeBFAfterTargetOperand(MCInst &Inst, unsigned Val,
5927                                                uint64_t Address,
5928                                                const void *Decoder) {
5929 
5930   uint64_t LocImm = Inst.getOperand(0).getImm();
5931   Val = LocImm + (2 << Val);
5932   if (!tryAddingSymbolicOperand(Address, Address + Val + 4, true, 4, Inst,
5933                                 Decoder))
5934     Inst.addOperand(MCOperand::createImm(Val));
5935   return MCDisassembler::Success;
5936 }
5937 
5938 static DecodeStatus DecodePredNoALOperand(MCInst &Inst, unsigned Val,
5939                                           uint64_t Address,
5940                                           const void *Decoder) {
5941   if (Val >= ARMCC::AL)  // also exclude the non-condition NV
5942     return MCDisassembler::Fail;
5943   Inst.addOperand(MCOperand::createImm(Val));
5944   return MCDisassembler::Success;
5945 }
5946 
5947 static DecodeStatus DecodeLOLoop(MCInst &Inst, unsigned Insn, uint64_t Address,
5948                                  const void *Decoder) {
5949   DecodeStatus S = MCDisassembler::Success;
5950 
5951   if (Inst.getOpcode() == ARM::MVE_LCTP)
5952     return S;
5953 
5954   unsigned Imm = fieldFromInstruction(Insn, 11, 1) |
5955                  fieldFromInstruction(Insn, 1, 10) << 1;
5956   switch (Inst.getOpcode()) {
5957   case ARM::t2LEUpdate:
5958   case ARM::MVE_LETP:
5959     Inst.addOperand(MCOperand::createReg(ARM::LR));
5960     Inst.addOperand(MCOperand::createReg(ARM::LR));
5961     LLVM_FALLTHROUGH;
5962   case ARM::t2LE:
5963     if (!Check(S, DecodeBFLabelOperand<false, true, 11>(Inst, Imm, Address,
5964                                                         Decoder)))
5965       return MCDisassembler::Fail;
5966     break;
5967   case ARM::t2WLS:
5968   case ARM::MVE_WLSTP_8:
5969   case ARM::MVE_WLSTP_16:
5970   case ARM::MVE_WLSTP_32:
5971   case ARM::MVE_WLSTP_64:
5972     Inst.addOperand(MCOperand::createReg(ARM::LR));
5973     if (!Check(S,
5974                DecoderGPRRegisterClass(Inst, fieldFromInstruction(Insn, 16, 4),
5975                                        Address, Decoder)) ||
5976         !Check(S, DecodeBFLabelOperand<false, false, 11>(Inst, Imm, Address,
5977                                                          Decoder)))
5978       return MCDisassembler::Fail;
5979     break;
5980   case ARM::t2DLS:
5981   case ARM::MVE_DLSTP_8:
5982   case ARM::MVE_DLSTP_16:
5983   case ARM::MVE_DLSTP_32:
5984   case ARM::MVE_DLSTP_64:
5985     unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5986     if (Rn == 0xF) {
5987       // Enforce all the rest of the instruction bits in LCTP, which
5988       // won't have been reliably checked based on LCTP's own tablegen
5989       // record, because we came to this decode by a roundabout route.
5990       uint32_t CanonicalLCTP = 0xF00FE001, SBZMask = 0x00300FFE;
5991       if ((Insn & ~SBZMask) != CanonicalLCTP)
5992         return MCDisassembler::Fail;   // a mandatory bit is wrong: hard fail
5993       if (Insn != CanonicalLCTP)
5994         Check(S, MCDisassembler::SoftFail); // an SBZ bit is wrong: soft fail
5995 
5996       Inst.setOpcode(ARM::MVE_LCTP);
5997     } else {
5998       Inst.addOperand(MCOperand::createReg(ARM::LR));
5999       if (!Check(S, DecoderGPRRegisterClass(Inst,
6000                                             fieldFromInstruction(Insn, 16, 4),
6001                                             Address, Decoder)))
6002         return MCDisassembler::Fail;
6003     }
6004     break;
6005   }
6006   return S;
6007 }
6008 
6009 static DecodeStatus DecodeLongShiftOperand(MCInst &Inst, unsigned Val,
6010                                            uint64_t Address,
6011                                            const void *Decoder) {
6012   DecodeStatus S = MCDisassembler::Success;
6013 
6014   if (Val == 0)
6015     Val = 32;
6016 
6017   Inst.addOperand(MCOperand::createImm(Val));
6018 
6019   return S;
6020 }
6021 
6022 static DecodeStatus DecodetGPROddRegisterClass(MCInst &Inst, unsigned RegNo,
6023                                    uint64_t Address, const void *Decoder) {
6024   if ((RegNo) + 1 > 11)
6025     return MCDisassembler::Fail;
6026 
6027   unsigned Register = GPRDecoderTable[(RegNo) + 1];
6028   Inst.addOperand(MCOperand::createReg(Register));
6029   return MCDisassembler::Success;
6030 }
6031 
6032 static DecodeStatus DecodetGPREvenRegisterClass(MCInst &Inst, unsigned RegNo,
6033                                    uint64_t Address, const void *Decoder) {
6034   if ((RegNo) > 14)
6035     return MCDisassembler::Fail;
6036 
6037   unsigned Register = GPRDecoderTable[(RegNo)];
6038   Inst.addOperand(MCOperand::createReg(Register));
6039   return MCDisassembler::Success;
6040 }
6041 
6042 static DecodeStatus DecodeVSCCLRM(MCInst &Inst, unsigned Insn, uint64_t Address,
6043                                   const void *Decoder) {
6044   DecodeStatus S = MCDisassembler::Success;
6045 
6046   Inst.addOperand(MCOperand::createImm(ARMCC::AL));
6047   Inst.addOperand(MCOperand::createReg(0));
6048   if (Inst.getOpcode() == ARM::VSCCLRMD) {
6049     unsigned reglist = (fieldFromInstruction(Insn, 1, 7) << 1) |
6050                        (fieldFromInstruction(Insn, 12, 4) << 8) |
6051                        (fieldFromInstruction(Insn, 22, 1) << 12);
6052     if (!Check(S, DecodeDPRRegListOperand(Inst, reglist, Address, Decoder))) {
6053       return MCDisassembler::Fail;
6054     }
6055   } else {
6056     unsigned reglist = fieldFromInstruction(Insn, 0, 8) |
6057                        (fieldFromInstruction(Insn, 22, 1) << 8) |
6058                        (fieldFromInstruction(Insn, 12, 4) << 9);
6059     if (!Check(S, DecodeSPRRegListOperand(Inst, reglist, Address, Decoder))) {
6060       return MCDisassembler::Fail;
6061     }
6062   }
6063   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6064 
6065   return S;
6066 }
6067 
6068 static DecodeStatus DecodeMQPRRegisterClass(MCInst &Inst, unsigned RegNo,
6069                               uint64_t Address,
6070                               const void *Decoder) {
6071   if (RegNo > 7)
6072     return MCDisassembler::Fail;
6073 
6074   unsigned Register = QPRDecoderTable[RegNo];
6075   Inst.addOperand(MCOperand::createReg(Register));
6076   return MCDisassembler::Success;
6077 }
6078 
6079 static const uint16_t QQPRDecoderTable[] = {
6080      ARM::Q0_Q1,  ARM::Q1_Q2,  ARM::Q2_Q3,  ARM::Q3_Q4,
6081      ARM::Q4_Q5,  ARM::Q5_Q6,  ARM::Q6_Q7
6082 };
6083 
6084 static DecodeStatus DecodeQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
6085                               uint64_t Address,
6086                               const void *Decoder) {
6087   if (RegNo > 6)
6088     return MCDisassembler::Fail;
6089 
6090   unsigned Register = QQPRDecoderTable[RegNo];
6091   Inst.addOperand(MCOperand::createReg(Register));
6092   return MCDisassembler::Success;
6093 }
6094 
6095 static const uint16_t QQQQPRDecoderTable[] = {
6096      ARM::Q0_Q1_Q2_Q3,  ARM::Q1_Q2_Q3_Q4,  ARM::Q2_Q3_Q4_Q5,
6097      ARM::Q3_Q4_Q5_Q6,  ARM::Q4_Q5_Q6_Q7
6098 };
6099 
6100 static DecodeStatus DecodeQQQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
6101                               uint64_t Address,
6102                               const void *Decoder) {
6103   if (RegNo > 4)
6104     return MCDisassembler::Fail;
6105 
6106   unsigned Register = QQQQPRDecoderTable[RegNo];
6107   Inst.addOperand(MCOperand::createReg(Register));
6108   return MCDisassembler::Success;
6109 }
6110 
6111 static DecodeStatus DecodeVPTMaskOperand(MCInst &Inst, unsigned Val,
6112                                          uint64_t Address,
6113                                          const void *Decoder) {
6114   DecodeStatus S = MCDisassembler::Success;
6115 
6116   // Parse VPT mask and encode it in the MCInst as an immediate with the same
6117   // format as the it_mask.  That is, from the second 'e|t' encode 'e' as 1 and
6118   // 't' as 0 and finish with a 1.
6119   unsigned Imm = 0;
6120   // We always start with a 't'.
6121   unsigned CurBit = 0;
6122   for (int i = 3; i >= 0; --i) {
6123     // If the bit we are looking at is not the same as last one, invert the
6124     // CurBit, if it is the same leave it as is.
6125     CurBit ^= (Val >> i) & 1U;
6126 
6127     // Encode the CurBit at the right place in the immediate.
6128     Imm |= (CurBit << i);
6129 
6130     // If we are done, finish the encoding with a 1.
6131     if ((Val & ~(~0U << i)) == 0) {
6132       Imm |= 1U << i;
6133       break;
6134     }
6135   }
6136 
6137   Inst.addOperand(MCOperand::createImm(Imm));
6138 
6139   return S;
6140 }
6141 
6142 static DecodeStatus DecodeVpredROperand(MCInst &Inst, unsigned RegNo,
6143                                         uint64_t Address, const void *Decoder) {
6144   // The vpred_r operand type includes an MQPR register field derived
6145   // from the encoding. But we don't actually want to add an operand
6146   // to the MCInst at this stage, because AddThumbPredicate will do it
6147   // later, and will infer the register number from the TIED_TO
6148   // constraint. So this is a deliberately empty decoder method that
6149   // will inhibit the auto-generated disassembly code from adding an
6150   // operand at all.
6151   return MCDisassembler::Success;
6152 }
6153 
6154 static DecodeStatus DecodeRestrictedIPredicateOperand(MCInst &Inst,
6155                                                       unsigned Val,
6156                                                       uint64_t Address,
6157                                                       const void *Decoder) {
6158   Inst.addOperand(MCOperand::createImm((Val & 0x1) == 0 ? ARMCC::EQ : ARMCC::NE));
6159   return MCDisassembler::Success;
6160 }
6161 
6162 static DecodeStatus DecodeRestrictedSPredicateOperand(MCInst &Inst,
6163                                                       unsigned Val,
6164                                                       uint64_t Address,
6165                                                       const void *Decoder) {
6166   unsigned Code;
6167   switch (Val & 0x3) {
6168   case 0:
6169     Code = ARMCC::GE;
6170     break;
6171   case 1:
6172     Code = ARMCC::LT;
6173     break;
6174   case 2:
6175     Code = ARMCC::GT;
6176     break;
6177   case 3:
6178     Code = ARMCC::LE;
6179     break;
6180   }
6181   Inst.addOperand(MCOperand::createImm(Code));
6182   return MCDisassembler::Success;
6183 }
6184 
6185 static DecodeStatus DecodeRestrictedUPredicateOperand(MCInst &Inst,
6186                                                       unsigned Val,
6187                                                       uint64_t Address,
6188                                                       const void *Decoder) {
6189   Inst.addOperand(MCOperand::createImm((Val & 0x1) == 0 ? ARMCC::HS : ARMCC::HI));
6190   return MCDisassembler::Success;
6191 }
6192 
6193 static DecodeStatus DecodeRestrictedFPPredicateOperand(MCInst &Inst, unsigned Val,
6194                                                      uint64_t Address,
6195                                                      const void *Decoder) {
6196   unsigned Code;
6197   switch (Val) {
6198   default:
6199     return MCDisassembler::Fail;
6200   case 0:
6201     Code = ARMCC::EQ;
6202     break;
6203   case 1:
6204     Code = ARMCC::NE;
6205     break;
6206   case 4:
6207     Code = ARMCC::GE;
6208     break;
6209   case 5:
6210     Code = ARMCC::LT;
6211     break;
6212   case 6:
6213     Code = ARMCC::GT;
6214     break;
6215   case 7:
6216     Code = ARMCC::LE;
6217     break;
6218   }
6219 
6220   Inst.addOperand(MCOperand::createImm(Code));
6221   return MCDisassembler::Success;
6222 }
6223 
6224 static DecodeStatus DecodeVCVTImmOperand(MCInst &Inst, unsigned Val,
6225                                          uint64_t Address, const void *Decoder) {
6226   DecodeStatus S = MCDisassembler::Success;
6227 
6228   unsigned DecodedVal = 64 - Val;
6229 
6230   switch (Inst.getOpcode()) {
6231   case ARM::MVE_VCVTf16s16_fix:
6232   case ARM::MVE_VCVTs16f16_fix:
6233   case ARM::MVE_VCVTf16u16_fix:
6234   case ARM::MVE_VCVTu16f16_fix:
6235     if (DecodedVal > 16)
6236       return MCDisassembler::Fail;
6237     break;
6238   case ARM::MVE_VCVTf32s32_fix:
6239   case ARM::MVE_VCVTs32f32_fix:
6240   case ARM::MVE_VCVTf32u32_fix:
6241   case ARM::MVE_VCVTu32f32_fix:
6242     if (DecodedVal > 32)
6243       return MCDisassembler::Fail;
6244     break;
6245   }
6246 
6247   Inst.addOperand(MCOperand::createImm(64 - Val));
6248 
6249   return S;
6250 }
6251 
6252 static unsigned FixedRegForVSTRVLDR_SYSREG(unsigned Opcode) {
6253   switch (Opcode) {
6254   case ARM::VSTR_P0_off:
6255   case ARM::VSTR_P0_pre:
6256   case ARM::VSTR_P0_post:
6257   case ARM::VLDR_P0_off:
6258   case ARM::VLDR_P0_pre:
6259   case ARM::VLDR_P0_post:
6260     return ARM::P0;
6261   default:
6262     return 0;
6263   }
6264 }
6265 
6266 template<bool Writeback>
6267 static DecodeStatus DecodeVSTRVLDR_SYSREG(MCInst &Inst, unsigned Val,
6268                                           uint64_t Address,
6269                                           const void *Decoder) {
6270   switch (Inst.getOpcode()) {
6271   case ARM::VSTR_FPSCR_pre:
6272   case ARM::VSTR_FPSCR_NZCVQC_pre:
6273   case ARM::VLDR_FPSCR_pre:
6274   case ARM::VLDR_FPSCR_NZCVQC_pre:
6275   case ARM::VSTR_FPSCR_off:
6276   case ARM::VSTR_FPSCR_NZCVQC_off:
6277   case ARM::VLDR_FPSCR_off:
6278   case ARM::VLDR_FPSCR_NZCVQC_off:
6279   case ARM::VSTR_FPSCR_post:
6280   case ARM::VSTR_FPSCR_NZCVQC_post:
6281   case ARM::VLDR_FPSCR_post:
6282   case ARM::VLDR_FPSCR_NZCVQC_post:
6283     const FeatureBitset &featureBits =
6284         ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
6285 
6286     if (!featureBits[ARM::HasMVEIntegerOps] && !featureBits[ARM::FeatureVFP2])
6287       return MCDisassembler::Fail;
6288   }
6289 
6290   DecodeStatus S = MCDisassembler::Success;
6291   if (unsigned Sysreg = FixedRegForVSTRVLDR_SYSREG(Inst.getOpcode()))
6292     Inst.addOperand(MCOperand::createReg(Sysreg));
6293   unsigned Rn = fieldFromInstruction(Val, 16, 4);
6294   unsigned addr = fieldFromInstruction(Val, 0, 7) |
6295                   (fieldFromInstruction(Val, 23, 1) << 7) | (Rn << 8);
6296 
6297   if (Writeback) {
6298     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
6299       return MCDisassembler::Fail;
6300   }
6301   if (!Check(S, DecodeT2AddrModeImm7s4(Inst, addr, Address, Decoder)))
6302     return MCDisassembler::Fail;
6303 
6304   Inst.addOperand(MCOperand::createImm(ARMCC::AL));
6305   Inst.addOperand(MCOperand::createReg(0));
6306 
6307   return S;
6308 }
6309 
6310 static inline DecodeStatus DecodeMVE_MEM_pre(
6311   MCInst &Inst, unsigned Val, uint64_t Address, const void *Decoder,
6312   unsigned Rn, OperandDecoder RnDecoder, OperandDecoder AddrDecoder) {
6313   DecodeStatus S = MCDisassembler::Success;
6314 
6315   unsigned Qd = fieldFromInstruction(Val, 13, 3);
6316   unsigned addr = fieldFromInstruction(Val, 0, 7) |
6317                   (fieldFromInstruction(Val, 23, 1) << 7) | (Rn << 8);
6318 
6319   if (!Check(S, RnDecoder(Inst, Rn, Address, Decoder)))
6320     return MCDisassembler::Fail;
6321   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6322     return MCDisassembler::Fail;
6323   if (!Check(S, AddrDecoder(Inst, addr, Address, Decoder)))
6324     return MCDisassembler::Fail;
6325 
6326   return S;
6327 }
6328 
6329 template <int shift>
6330 static DecodeStatus DecodeMVE_MEM_1_pre(MCInst &Inst, unsigned Val,
6331                                         uint64_t Address, const void *Decoder) {
6332   return DecodeMVE_MEM_pre(Inst, Val, Address, Decoder,
6333                            fieldFromInstruction(Val, 16, 3),
6334                            DecodetGPRRegisterClass,
6335                            DecodeTAddrModeImm7<shift>);
6336 }
6337 
6338 template <int shift>
6339 static DecodeStatus DecodeMVE_MEM_2_pre(MCInst &Inst, unsigned Val,
6340                                         uint64_t Address, const void *Decoder) {
6341   return DecodeMVE_MEM_pre(Inst, Val, Address, Decoder,
6342                            fieldFromInstruction(Val, 16, 4),
6343                            DecoderGPRRegisterClass,
6344                            DecodeT2AddrModeImm7<shift,1>);
6345 }
6346 
6347 template <int shift>
6348 static DecodeStatus DecodeMVE_MEM_3_pre(MCInst &Inst, unsigned Val,
6349                                         uint64_t Address, const void *Decoder) {
6350   return DecodeMVE_MEM_pre(Inst, Val, Address, Decoder,
6351                            fieldFromInstruction(Val, 17, 3),
6352                            DecodeMQPRRegisterClass,
6353                            DecodeMveAddrModeQ<shift>);
6354 }
6355 
6356 template<unsigned MinLog, unsigned MaxLog>
6357 static DecodeStatus DecodePowerTwoOperand(MCInst &Inst, unsigned Val,
6358                                           uint64_t Address,
6359                                           const void *Decoder) {
6360   DecodeStatus S = MCDisassembler::Success;
6361 
6362   if (Val < MinLog || Val > MaxLog)
6363     return MCDisassembler::Fail;
6364 
6365   Inst.addOperand(MCOperand::createImm(1LL << Val));
6366   return S;
6367 }
6368 
6369 template <int shift>
6370 static DecodeStatus DecodeExpandedImmOperand(MCInst &Inst, unsigned Val,
6371                                              uint64_t Address,
6372                                              const void *Decoder) {
6373     Val <<= shift;
6374 
6375     Inst.addOperand(MCOperand::createImm(Val));
6376     return MCDisassembler::Success;
6377 }
6378 
6379 template<unsigned start>
6380 static DecodeStatus DecodeMVEPairVectorIndexOperand(MCInst &Inst, unsigned Val,
6381                                                     uint64_t Address,
6382                                                     const void *Decoder) {
6383   DecodeStatus S = MCDisassembler::Success;
6384 
6385   Inst.addOperand(MCOperand::createImm(start + Val));
6386 
6387   return S;
6388 }
6389 
6390 static DecodeStatus DecodeMVEVMOVQtoDReg(MCInst &Inst, unsigned Insn,
6391                                          uint64_t Address, const void *Decoder) {
6392   DecodeStatus S = MCDisassembler::Success;
6393   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
6394   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
6395   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
6396                  fieldFromInstruction(Insn, 13, 3));
6397   unsigned index = fieldFromInstruction(Insn, 4, 1);
6398 
6399   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
6400     return MCDisassembler::Fail;
6401   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2, Address, Decoder)))
6402     return MCDisassembler::Fail;
6403   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6404     return MCDisassembler::Fail;
6405   if (!Check(S, DecodeMVEPairVectorIndexOperand<2>(Inst, index, Address, Decoder)))
6406     return MCDisassembler::Fail;
6407   if (!Check(S, DecodeMVEPairVectorIndexOperand<0>(Inst, index, Address, Decoder)))
6408     return MCDisassembler::Fail;
6409 
6410   return S;
6411 }
6412 
6413 static DecodeStatus DecodeMVEVMOVDRegtoQ(MCInst &Inst, unsigned Insn,
6414                                          uint64_t Address, const void *Decoder) {
6415   DecodeStatus S = MCDisassembler::Success;
6416   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
6417   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
6418   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
6419                  fieldFromInstruction(Insn, 13, 3));
6420   unsigned index = fieldFromInstruction(Insn, 4, 1);
6421 
6422   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6423     return MCDisassembler::Fail;
6424   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6425     return MCDisassembler::Fail;
6426   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
6427     return MCDisassembler::Fail;
6428   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2, Address, Decoder)))
6429     return MCDisassembler::Fail;
6430   if (!Check(S, DecodeMVEPairVectorIndexOperand<2>(Inst, index, Address, Decoder)))
6431     return MCDisassembler::Fail;
6432   if (!Check(S, DecodeMVEPairVectorIndexOperand<0>(Inst, index, Address, Decoder)))
6433     return MCDisassembler::Fail;
6434 
6435   return S;
6436 }
6437 
6438 static DecodeStatus DecodeMVEOverlappingLongShift(
6439   MCInst &Inst, unsigned Insn, uint64_t Address, const void *Decoder) {
6440   DecodeStatus S = MCDisassembler::Success;
6441 
6442   unsigned RdaLo = fieldFromInstruction(Insn, 17, 3) << 1;
6443   unsigned RdaHi = fieldFromInstruction(Insn, 9, 3) << 1;
6444   unsigned Rm = fieldFromInstruction(Insn, 12, 4);
6445 
6446   if (RdaHi == 14) {
6447     // This value of RdaHi (really indicating pc, because RdaHi has to
6448     // be an odd-numbered register, so the low bit will be set by the
6449     // decode function below) indicates that we must decode as SQRSHR
6450     // or UQRSHL, which both have a single Rda register field with all
6451     // four bits.
6452     unsigned Rda = fieldFromInstruction(Insn, 16, 4);
6453 
6454     switch (Inst.getOpcode()) {
6455       case ARM::MVE_ASRLr:
6456       case ARM::MVE_SQRSHRL:
6457         Inst.setOpcode(ARM::MVE_SQRSHR);
6458         break;
6459       case ARM::MVE_LSLLr:
6460       case ARM::MVE_UQRSHLL:
6461         Inst.setOpcode(ARM::MVE_UQRSHL);
6462         break;
6463       default:
6464         llvm_unreachable("Unexpected starting opcode!");
6465     }
6466 
6467     // Rda as output parameter
6468     if (!Check(S, DecoderGPRRegisterClass(Inst, Rda, Address, Decoder)))
6469       return MCDisassembler::Fail;
6470 
6471     // Rda again as input parameter
6472     if (!Check(S, DecoderGPRRegisterClass(Inst, Rda, Address, Decoder)))
6473       return MCDisassembler::Fail;
6474 
6475     // Rm, the amount to shift by
6476     if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
6477       return MCDisassembler::Fail;
6478 
6479     return S;
6480   }
6481 
6482   // Otherwise, we decode as whichever opcode our caller has already
6483   // put into Inst. Those all look the same:
6484 
6485   // RdaLo,RdaHi as output parameters
6486   if (!Check(S, DecodetGPREvenRegisterClass(Inst, RdaLo, Address, Decoder)))
6487     return MCDisassembler::Fail;
6488   if (!Check(S, DecodetGPROddRegisterClass(Inst, RdaHi, Address, Decoder)))
6489     return MCDisassembler::Fail;
6490 
6491   // RdaLo,RdaHi again as input parameters
6492   if (!Check(S, DecodetGPREvenRegisterClass(Inst, RdaLo, Address, Decoder)))
6493     return MCDisassembler::Fail;
6494   if (!Check(S, DecodetGPROddRegisterClass(Inst, RdaHi, Address, Decoder)))
6495     return MCDisassembler::Fail;
6496 
6497   // Rm, the amount to shift by
6498   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
6499     return MCDisassembler::Fail;
6500 
6501   return S;
6502 }
6503 
6504 static DecodeStatus DecodeMVEVCVTt1fp(MCInst &Inst, unsigned Insn, uint64_t Address,
6505                                       const void *Decoder) {
6506   DecodeStatus S = MCDisassembler::Success;
6507   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
6508                  fieldFromInstruction(Insn, 13, 3));
6509   unsigned Qm = ((fieldFromInstruction(Insn, 5, 1) << 3) |
6510                  fieldFromInstruction(Insn, 1, 3));
6511   unsigned imm6 = fieldFromInstruction(Insn, 16, 6);
6512 
6513   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6514     return MCDisassembler::Fail;
6515   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
6516     return MCDisassembler::Fail;
6517   if (!Check(S, DecodeVCVTImmOperand(Inst, imm6, Address, Decoder)))
6518     return MCDisassembler::Fail;
6519 
6520   return S;
6521 }
6522 
6523 template<bool scalar, OperandDecoder predicate_decoder>
6524 static DecodeStatus DecodeMVEVCMP(MCInst &Inst, unsigned Insn, uint64_t Address,
6525                                   const void *Decoder) {
6526   DecodeStatus S = MCDisassembler::Success;
6527   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6528   unsigned Qn = fieldFromInstruction(Insn, 17, 3);
6529   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qn, Address, Decoder)))
6530     return MCDisassembler::Fail;
6531 
6532   unsigned fc;
6533 
6534   if (scalar) {
6535     fc = fieldFromInstruction(Insn, 12, 1) << 2 |
6536          fieldFromInstruction(Insn, 7, 1) |
6537          fieldFromInstruction(Insn, 5, 1) << 1;
6538     unsigned Rm = fieldFromInstruction(Insn, 0, 4);
6539     if (!Check(S, DecodeGPRwithZRRegisterClass(Inst, Rm, Address, Decoder)))
6540       return MCDisassembler::Fail;
6541   } else {
6542     fc = fieldFromInstruction(Insn, 12, 1) << 2 |
6543          fieldFromInstruction(Insn, 7, 1) |
6544          fieldFromInstruction(Insn, 0, 1) << 1;
6545     unsigned Qm = fieldFromInstruction(Insn, 5, 1) << 4 |
6546                   fieldFromInstruction(Insn, 1, 3);
6547     if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
6548       return MCDisassembler::Fail;
6549   }
6550 
6551   if (!Check(S, predicate_decoder(Inst, fc, Address, Decoder)))
6552     return MCDisassembler::Fail;
6553 
6554   Inst.addOperand(MCOperand::createImm(ARMVCC::None));
6555   Inst.addOperand(MCOperand::createReg(0));
6556   Inst.addOperand(MCOperand::createImm(0));
6557 
6558   return S;
6559 }
6560 
6561 static DecodeStatus DecodeMveVCTP(MCInst &Inst, unsigned Insn, uint64_t Address,
6562                                   const void *Decoder) {
6563   DecodeStatus S = MCDisassembler::Success;
6564   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6565   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
6566   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
6567     return MCDisassembler::Fail;
6568   return S;
6569 }
6570