xref: /llvm-project/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp (revision d88e28d13e66dfd9bd9dc22e21d82793161c5391)
1 //===- ARMDisassembler.cpp - Disassembler for ARM/Thumb ISA ---------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "ARMBaseInstrInfo.h"
10 #include "MCTargetDesc/ARMAddressingModes.h"
11 #include "MCTargetDesc/ARMBaseInfo.h"
12 #include "MCTargetDesc/ARMMCTargetDesc.h"
13 #include "TargetInfo/ARMTargetInfo.h"
14 #include "Utils/ARMBaseInfo.h"
15 #include "llvm/MC/MCContext.h"
16 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
17 #include "llvm/MC/MCFixedLenDisassembler.h"
18 #include "llvm/MC/MCInst.h"
19 #include "llvm/MC/MCInstrDesc.h"
20 #include "llvm/MC/MCSubtargetInfo.h"
21 #include "llvm/MC/SubtargetFeature.h"
22 #include "llvm/Support/Compiler.h"
23 #include "llvm/Support/ErrorHandling.h"
24 #include "llvm/Support/MathExtras.h"
25 #include "llvm/Support/TargetRegistry.h"
26 #include "llvm/Support/raw_ostream.h"
27 #include <algorithm>
28 #include <cassert>
29 #include <cstdint>
30 #include <vector>
31 
32 using namespace llvm;
33 
34 #define DEBUG_TYPE "arm-disassembler"
35 
36 using DecodeStatus = MCDisassembler::DecodeStatus;
37 
38 namespace {
39 
40   // Handles the condition code status of instructions in IT blocks
41   class ITStatus
42   {
43     public:
44       // Returns the condition code for instruction in IT block
45       unsigned getITCC() {
46         unsigned CC = ARMCC::AL;
47         if (instrInITBlock())
48           CC = ITStates.back();
49         return CC;
50       }
51 
52       // Advances the IT block state to the next T or E
53       void advanceITState() {
54         ITStates.pop_back();
55       }
56 
57       // Returns true if the current instruction is in an IT block
58       bool instrInITBlock() {
59         return !ITStates.empty();
60       }
61 
62       // Returns true if current instruction is the last instruction in an IT block
63       bool instrLastInITBlock() {
64         return ITStates.size() == 1;
65       }
66 
67       // Called when decoding an IT instruction. Sets the IT state for
68       // the following instructions that for the IT block. Firstcond
69       // corresponds to the field in the IT instruction encoding; Mask
70       // is in the MCOperand format in which 1 means 'else' and 0 'then'.
71       void setITState(char Firstcond, char Mask) {
72         // (3 - the number of trailing zeros) is the number of then / else.
73         unsigned NumTZ = countTrailingZeros<uint8_t>(Mask);
74         unsigned char CCBits = static_cast<unsigned char>(Firstcond & 0xf);
75         assert(NumTZ <= 3 && "Invalid IT mask!");
76         // push condition codes onto the stack the correct order for the pops
77         for (unsigned Pos = NumTZ+1; Pos <= 3; ++Pos) {
78           unsigned Else = (Mask >> Pos) & 1;
79           ITStates.push_back(CCBits ^ Else);
80         }
81         ITStates.push_back(CCBits);
82       }
83 
84     private:
85       std::vector<unsigned char> ITStates;
86   };
87 
88   class VPTStatus
89   {
90     public:
91       unsigned getVPTPred() {
92         unsigned Pred = ARMVCC::None;
93         if (instrInVPTBlock())
94           Pred = VPTStates.back();
95         return Pred;
96       }
97 
98       void advanceVPTState() {
99         VPTStates.pop_back();
100       }
101 
102       bool instrInVPTBlock() {
103         return !VPTStates.empty();
104       }
105 
106       bool instrLastInVPTBlock() {
107         return VPTStates.size() == 1;
108       }
109 
110       void setVPTState(char Mask) {
111         // (3 - the number of trailing zeros) is the number of then / else.
112         unsigned NumTZ = countTrailingZeros<uint8_t>(Mask);
113         assert(NumTZ <= 3 && "Invalid VPT mask!");
114         // push predicates onto the stack the correct order for the pops
115         for (unsigned Pos = NumTZ+1; Pos <= 3; ++Pos) {
116           bool T = ((Mask >> Pos) & 1) == 0;
117           if (T)
118             VPTStates.push_back(ARMVCC::Then);
119           else
120             VPTStates.push_back(ARMVCC::Else);
121         }
122         VPTStates.push_back(ARMVCC::Then);
123       }
124 
125     private:
126       SmallVector<unsigned char, 4> VPTStates;
127   };
128 
129 /// ARM disassembler for all ARM platforms.
130 class ARMDisassembler : public MCDisassembler {
131 public:
132   ARMDisassembler(const MCSubtargetInfo &STI, MCContext &Ctx) :
133     MCDisassembler(STI, Ctx) {
134   }
135 
136   ~ARMDisassembler() override = default;
137 
138   DecodeStatus getInstruction(MCInst &Instr, uint64_t &Size,
139                               ArrayRef<uint8_t> Bytes, uint64_t Address,
140                               raw_ostream &VStream,
141                               raw_ostream &CStream) const override;
142 
143 private:
144   DecodeStatus getARMInstruction(MCInst &Instr, uint64_t &Size,
145                                  ArrayRef<uint8_t> Bytes, uint64_t Address,
146                                  raw_ostream &VStream,
147                                  raw_ostream &CStream) const;
148 
149   DecodeStatus getThumbInstruction(MCInst &Instr, uint64_t &Size,
150                                    ArrayRef<uint8_t> Bytes, uint64_t Address,
151                                    raw_ostream &VStream,
152                                    raw_ostream &CStream) const;
153 
154   mutable ITStatus ITBlock;
155   mutable VPTStatus VPTBlock;
156 
157   DecodeStatus AddThumbPredicate(MCInst&) const;
158   void UpdateThumbVFPPredicate(DecodeStatus &, MCInst&) const;
159 };
160 
161 } // end anonymous namespace
162 
163 static bool Check(DecodeStatus &Out, DecodeStatus In) {
164   switch (In) {
165     case MCDisassembler::Success:
166       // Out stays the same.
167       return true;
168     case MCDisassembler::SoftFail:
169       Out = In;
170       return true;
171     case MCDisassembler::Fail:
172       Out = In;
173       return false;
174   }
175   llvm_unreachable("Invalid DecodeStatus!");
176 }
177 
178 // Forward declare these because the autogenerated code will reference them.
179 // Definitions are further down.
180 static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, unsigned RegNo,
181                                    uint64_t Address, const void *Decoder);
182 static DecodeStatus DecodeCLRMGPRRegisterClass(MCInst &Inst, unsigned RegNo,
183                                    uint64_t Address, const void *Decoder);
184 static DecodeStatus DecodetGPROddRegisterClass(MCInst &Inst, unsigned RegNo,
185                                    uint64_t Address, const void *Decoder);
186 static DecodeStatus DecodetGPREvenRegisterClass(MCInst &Inst, unsigned RegNo,
187                                    uint64_t Address, const void *Decoder);
188 static DecodeStatus DecodeGPRnopcRegisterClass(MCInst &Inst,
189                                                unsigned RegNo, uint64_t Address,
190                                                const void *Decoder);
191 static DecodeStatus DecodeGPRwithAPSRRegisterClass(MCInst &Inst,
192                                                unsigned RegNo, uint64_t Address,
193                                                const void *Decoder);
194 static DecodeStatus DecodeGPRwithZRRegisterClass(MCInst &Inst,
195                                                unsigned RegNo, uint64_t Address,
196                                                const void *Decoder);
197 static DecodeStatus DecodetGPRRegisterClass(MCInst &Inst, unsigned RegNo,
198                                    uint64_t Address, const void *Decoder);
199 static DecodeStatus DecodetcGPRRegisterClass(MCInst &Inst, unsigned RegNo,
200                                    uint64_t Address, const void *Decoder);
201 static DecodeStatus DecoderGPRRegisterClass(MCInst &Inst, unsigned RegNo,
202                                    uint64_t Address, const void *Decoder);
203 static DecodeStatus DecodeGPRPairRegisterClass(MCInst &Inst, unsigned RegNo,
204                                    uint64_t Address, const void *Decoder);
205 static DecodeStatus DecodeHPRRegisterClass(MCInst &Inst, unsigned RegNo,
206                                    uint64_t Address, const void *Decoder);
207 static DecodeStatus DecodeSPRRegisterClass(MCInst &Inst, unsigned RegNo,
208                                    uint64_t Address, const void *Decoder);
209 static DecodeStatus DecodeDPRRegisterClass(MCInst &Inst, unsigned RegNo,
210                                    uint64_t Address, const void *Decoder);
211 static DecodeStatus DecodeDPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
212                                    uint64_t Address, const void *Decoder);
213 static DecodeStatus DecodeSPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
214                                    uint64_t Address, const void *Decoder);
215 static DecodeStatus DecodeDPR_VFP2RegisterClass(MCInst &Inst,
216                                                 unsigned RegNo,
217                                                 uint64_t Address,
218                                                 const void *Decoder);
219 static DecodeStatus DecodeQPRRegisterClass(MCInst &Inst, unsigned RegNo,
220                                    uint64_t Address, const void *Decoder);
221 static DecodeStatus DecodeMQPRRegisterClass(MCInst &Inst, unsigned RegNo,
222                                    uint64_t Address, const void *Decoder);
223 static DecodeStatus DecodeDPairRegisterClass(MCInst &Inst, unsigned RegNo,
224                                    uint64_t Address, const void *Decoder);
225 static DecodeStatus DecodeDPairSpacedRegisterClass(MCInst &Inst,
226                                unsigned RegNo, uint64_t Address,
227                                const void *Decoder);
228 
229 static DecodeStatus DecodePredicateOperand(MCInst &Inst, unsigned Val,
230                                uint64_t Address, const void *Decoder);
231 static DecodeStatus DecodeCCOutOperand(MCInst &Inst, unsigned Val,
232                                uint64_t Address, const void *Decoder);
233 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Val,
234                                uint64_t Address, const void *Decoder);
235 static DecodeStatus DecodeSPRRegListOperand(MCInst &Inst, unsigned Val,
236                                uint64_t Address, const void *Decoder);
237 static DecodeStatus DecodeDPRRegListOperand(MCInst &Inst, unsigned Val,
238                                uint64_t Address, const void *Decoder);
239 
240 static DecodeStatus DecodeBitfieldMaskOperand(MCInst &Inst, unsigned Insn,
241                                uint64_t Address, const void *Decoder);
242 static DecodeStatus DecodeCopMemInstruction(MCInst &Inst, unsigned Insn,
243                                uint64_t Address, const void *Decoder);
244 static DecodeStatus DecodeAddrMode2IdxInstruction(MCInst &Inst,
245                                                   unsigned Insn,
246                                                   uint64_t Address,
247                                                   const void *Decoder);
248 static DecodeStatus DecodeSORegMemOperand(MCInst &Inst, unsigned Insn,
249                                uint64_t Address, const void *Decoder);
250 static DecodeStatus DecodeAddrMode3Instruction(MCInst &Inst,unsigned Insn,
251                                uint64_t Address, const void *Decoder);
252 static DecodeStatus DecodeSORegImmOperand(MCInst &Inst, unsigned Insn,
253                                uint64_t Address, const void *Decoder);
254 static DecodeStatus DecodeSORegRegOperand(MCInst &Inst, unsigned Insn,
255                                uint64_t Address, const void *Decoder);
256 
257 static DecodeStatus DecodeMemMultipleWritebackInstruction(MCInst & Inst,
258                                                   unsigned Insn,
259                                                   uint64_t Adddress,
260                                                   const void *Decoder);
261 static DecodeStatus DecodeT2MOVTWInstruction(MCInst &Inst, unsigned Insn,
262                                uint64_t Address, const void *Decoder);
263 static DecodeStatus DecodeArmMOVTWInstruction(MCInst &Inst, unsigned Insn,
264                                uint64_t Address, const void *Decoder);
265 static DecodeStatus DecodeSMLAInstruction(MCInst &Inst, unsigned Insn,
266                                uint64_t Address, const void *Decoder);
267 static DecodeStatus DecodeHINTInstruction(MCInst &Inst, unsigned Insn,
268                                uint64_t Address, const void *Decoder);
269 static DecodeStatus DecodeCPSInstruction(MCInst &Inst, unsigned Insn,
270                                uint64_t Address, const void *Decoder);
271 static DecodeStatus DecodeTSTInstruction(MCInst &Inst, unsigned Insn,
272                                uint64_t Address, const void *Decoder);
273 static DecodeStatus DecodeSETPANInstruction(MCInst &Inst, unsigned Insn,
274                                uint64_t Address, const void *Decoder);
275 static DecodeStatus DecodeT2CPSInstruction(MCInst &Inst, unsigned Insn,
276                                uint64_t Address, const void *Decoder);
277 static DecodeStatus DecodeAddrModeImm12Operand(MCInst &Inst, unsigned Val,
278                                uint64_t Address, const void *Decoder);
279 static DecodeStatus DecodeAddrMode5Operand(MCInst &Inst, unsigned Val,
280                                uint64_t Address, const void *Decoder);
281 static DecodeStatus DecodeAddrMode5FP16Operand(MCInst &Inst, unsigned Val,
282                                uint64_t Address, const void *Decoder);
283 static DecodeStatus DecodeAddrMode7Operand(MCInst &Inst, unsigned Val,
284                                uint64_t Address, const void *Decoder);
285 static DecodeStatus DecodeT2BInstruction(MCInst &Inst, unsigned Insn,
286                                uint64_t Address, const void *Decoder);
287 static DecodeStatus DecodeBranchImmInstruction(MCInst &Inst,unsigned Insn,
288                                uint64_t Address, const void *Decoder);
289 static DecodeStatus DecodeAddrMode6Operand(MCInst &Inst, unsigned Val,
290                                uint64_t Address, const void *Decoder);
291 static DecodeStatus DecodeVLDST1Instruction(MCInst &Inst, unsigned Val,
292                                uint64_t Address, const void *Decoder);
293 static DecodeStatus DecodeVLDST2Instruction(MCInst &Inst, unsigned Val,
294                                uint64_t Address, const void *Decoder);
295 static DecodeStatus DecodeVLDST3Instruction(MCInst &Inst, unsigned Val,
296                                uint64_t Address, const void *Decoder);
297 static DecodeStatus DecodeVLDST4Instruction(MCInst &Inst, unsigned Val,
298                                uint64_t Address, const void *Decoder);
299 static DecodeStatus DecodeVLDInstruction(MCInst &Inst, unsigned Val,
300                                uint64_t Address, const void *Decoder);
301 static DecodeStatus DecodeVSTInstruction(MCInst &Inst, unsigned Val,
302                                uint64_t Address, const void *Decoder);
303 static DecodeStatus DecodeVLD1DupInstruction(MCInst &Inst, unsigned Val,
304                                uint64_t Address, const void *Decoder);
305 static DecodeStatus DecodeVLD2DupInstruction(MCInst &Inst, unsigned Val,
306                                uint64_t Address, const void *Decoder);
307 static DecodeStatus DecodeVLD3DupInstruction(MCInst &Inst, unsigned Val,
308                                uint64_t Address, const void *Decoder);
309 static DecodeStatus DecodeVLD4DupInstruction(MCInst &Inst, unsigned Val,
310                                uint64_t Address, const void *Decoder);
311 static DecodeStatus DecodeNEONModImmInstruction(MCInst &Inst,unsigned Val,
312                                uint64_t Address, const void *Decoder);
313 static DecodeStatus DecodeVSHLMaxInstruction(MCInst &Inst, unsigned Val,
314                                uint64_t Address, const void *Decoder);
315 static DecodeStatus DecodeShiftRight8Imm(MCInst &Inst, unsigned Val,
316                                uint64_t Address, const void *Decoder);
317 static DecodeStatus DecodeShiftRight16Imm(MCInst &Inst, unsigned Val,
318                                uint64_t Address, const void *Decoder);
319 static DecodeStatus DecodeShiftRight32Imm(MCInst &Inst, unsigned Val,
320                                uint64_t Address, const void *Decoder);
321 static DecodeStatus DecodeShiftRight64Imm(MCInst &Inst, unsigned Val,
322                                uint64_t Address, const void *Decoder);
323 static DecodeStatus DecodeTBLInstruction(MCInst &Inst, unsigned Insn,
324                                uint64_t Address, const void *Decoder);
325 static DecodeStatus DecodePostIdxReg(MCInst &Inst, unsigned Insn,
326                                uint64_t Address, const void *Decoder);
327 static DecodeStatus DecodeCoprocessor(MCInst &Inst, unsigned Insn,
328                                uint64_t Address, const void *Decoder);
329 static DecodeStatus DecodeMemBarrierOption(MCInst &Inst, unsigned Insn,
330                                uint64_t Address, const void *Decoder);
331 static DecodeStatus DecodeInstSyncBarrierOption(MCInst &Inst, unsigned Insn,
332                                uint64_t Address, const void *Decoder);
333 static DecodeStatus DecodeMSRMask(MCInst &Inst, unsigned Insn,
334                                uint64_t Address, const void *Decoder);
335 static DecodeStatus DecodeBankedReg(MCInst &Inst, unsigned Insn,
336                                uint64_t Address, const void *Decoder);
337 static DecodeStatus DecodeDoubleRegLoad(MCInst &Inst, unsigned Insn,
338                                uint64_t Address, const void *Decoder);
339 static DecodeStatus DecodeDoubleRegStore(MCInst &Inst, unsigned Insn,
340                                uint64_t Address, const void *Decoder);
341 static DecodeStatus DecodeLDRPreImm(MCInst &Inst, unsigned Insn,
342                                uint64_t Address, const void *Decoder);
343 static DecodeStatus DecodeLDRPreReg(MCInst &Inst, unsigned Insn,
344                                uint64_t Address, const void *Decoder);
345 static DecodeStatus DecodeSTRPreImm(MCInst &Inst, unsigned Insn,
346                                uint64_t Address, const void *Decoder);
347 static DecodeStatus DecodeSTRPreReg(MCInst &Inst, unsigned Insn,
348                                uint64_t Address, const void *Decoder);
349 static DecodeStatus DecodeVLD1LN(MCInst &Inst, unsigned Insn,
350                                uint64_t Address, const void *Decoder);
351 static DecodeStatus DecodeVLD2LN(MCInst &Inst, unsigned Insn,
352                                uint64_t Address, const void *Decoder);
353 static DecodeStatus DecodeVLD3LN(MCInst &Inst, unsigned Insn,
354                                uint64_t Address, const void *Decoder);
355 static DecodeStatus DecodeVLD4LN(MCInst &Inst, unsigned Insn,
356                                uint64_t Address, const void *Decoder);
357 static DecodeStatus DecodeVST1LN(MCInst &Inst, unsigned Insn,
358                                uint64_t Address, const void *Decoder);
359 static DecodeStatus DecodeVST2LN(MCInst &Inst, unsigned Insn,
360                                uint64_t Address, const void *Decoder);
361 static DecodeStatus DecodeVST3LN(MCInst &Inst, unsigned Insn,
362                                uint64_t Address, const void *Decoder);
363 static DecodeStatus DecodeVST4LN(MCInst &Inst, unsigned Insn,
364                                uint64_t Address, const void *Decoder);
365 static DecodeStatus DecodeVMOVSRR(MCInst &Inst, unsigned Insn,
366                                uint64_t Address, const void *Decoder);
367 static DecodeStatus DecodeVMOVRRS(MCInst &Inst, unsigned Insn,
368                                uint64_t Address, const void *Decoder);
369 static DecodeStatus DecodeSwap(MCInst &Inst, unsigned Insn,
370                                uint64_t Address, const void *Decoder);
371 static DecodeStatus DecodeVCVTD(MCInst &Inst, unsigned Insn,
372                                 uint64_t Address, const void *Decoder);
373 static DecodeStatus DecodeVCVTQ(MCInst &Inst, unsigned Insn,
374                                 uint64_t Address, const void *Decoder);
375 static DecodeStatus DecodeNEONComplexLane64Instruction(MCInst &Inst,
376                                                        unsigned Val,
377                                                        uint64_t Address,
378                                                        const void *Decoder);
379 
380 static DecodeStatus DecodeThumbAddSpecialReg(MCInst &Inst, uint16_t Insn,
381                                uint64_t Address, const void *Decoder);
382 static DecodeStatus DecodeThumbBROperand(MCInst &Inst, unsigned Val,
383                                uint64_t Address, const void *Decoder);
384 static DecodeStatus DecodeT2BROperand(MCInst &Inst, unsigned Val,
385                                uint64_t Address, const void *Decoder);
386 static DecodeStatus DecodeThumbCmpBROperand(MCInst &Inst, unsigned Val,
387                                uint64_t Address, const void *Decoder);
388 static DecodeStatus DecodeThumbAddrModeRR(MCInst &Inst, unsigned Val,
389                                uint64_t Address, const void *Decoder);
390 static DecodeStatus DecodeThumbAddrModeIS(MCInst &Inst, unsigned Val,
391                                uint64_t Address, const void *Decoder);
392 static DecodeStatus DecodeThumbAddrModePC(MCInst &Inst, unsigned Val,
393                                uint64_t Address, const void *Decoder);
394 static DecodeStatus DecodeThumbAddrModeSP(MCInst &Inst, unsigned Val,
395                                uint64_t Address, const void *Decoder);
396 static DecodeStatus DecodeT2AddrModeSOReg(MCInst &Inst, unsigned Val,
397                                uint64_t Address, const void *Decoder);
398 static DecodeStatus DecodeT2LoadShift(MCInst &Inst, unsigned Val,
399                                uint64_t Address, const void *Decoder);
400 static DecodeStatus DecodeT2LoadImm8(MCInst &Inst, unsigned Insn,
401                                uint64_t Address, const void* Decoder);
402 static DecodeStatus DecodeT2LoadImm12(MCInst &Inst, unsigned Insn,
403                                uint64_t Address, const void* Decoder);
404 static DecodeStatus DecodeT2LoadT(MCInst &Inst, unsigned Insn,
405                                uint64_t Address, const void* Decoder);
406 static DecodeStatus DecodeT2LoadLabel(MCInst &Inst, unsigned Insn,
407                                uint64_t Address, const void* Decoder);
408 static DecodeStatus DecodeT2Imm8S4(MCInst &Inst, unsigned Val,
409                                uint64_t Address, const void *Decoder);
410 static DecodeStatus DecodeT2Imm7S4(MCInst &Inst, unsigned Val,
411                                uint64_t Address, const void *Decoder);
412 static DecodeStatus DecodeT2AddrModeImm8s4(MCInst &Inst, unsigned Val,
413                                uint64_t Address, const void *Decoder);
414 static DecodeStatus DecodeT2AddrModeImm7s4(MCInst &Inst, unsigned Val,
415                                            uint64_t Address,
416                                            const void *Decoder);
417 static DecodeStatus DecodeT2AddrModeImm0_1020s4(MCInst &Inst,unsigned Val,
418                                uint64_t Address, const void *Decoder);
419 static DecodeStatus DecodeT2Imm8(MCInst &Inst, unsigned Val,
420                                uint64_t Address, const void *Decoder);
421 static DecodeStatus DecodeT2AddrModeImm8(MCInst &Inst, unsigned Val,
422                                uint64_t Address, const void *Decoder);
423 static DecodeStatus DecodeThumbAddSPImm(MCInst &Inst, uint16_t Val,
424                                uint64_t Address, const void *Decoder);
425 static DecodeStatus DecodeThumbAddSPReg(MCInst &Inst, uint16_t Insn,
426                                 uint64_t Address, const void *Decoder);
427 static DecodeStatus DecodeThumbCPS(MCInst &Inst, uint16_t Insn,
428                                 uint64_t Address, const void *Decoder);
429 static DecodeStatus DecodeQADDInstruction(MCInst &Inst, unsigned Insn,
430                                 uint64_t Address, const void *Decoder);
431 static DecodeStatus DecodeThumbBLXOffset(MCInst &Inst, unsigned Insn,
432                                 uint64_t Address, const void *Decoder);
433 static DecodeStatus DecodeT2AddrModeImm12(MCInst &Inst, unsigned Val,
434                                 uint64_t Address, const void *Decoder);
435 static DecodeStatus DecodeThumbTableBranch(MCInst &Inst, unsigned Val,
436                                 uint64_t Address, const void *Decoder);
437 static DecodeStatus DecodeThumb2BCCInstruction(MCInst &Inst, unsigned Val,
438                                 uint64_t Address, const void *Decoder);
439 static DecodeStatus DecodeT2SOImm(MCInst &Inst, unsigned Val,
440                                 uint64_t Address, const void *Decoder);
441 static DecodeStatus DecodeThumbBCCTargetOperand(MCInst &Inst,unsigned Val,
442                                 uint64_t Address, const void *Decoder);
443 static DecodeStatus DecodeThumbBLTargetOperand(MCInst &Inst, unsigned Val,
444                                 uint64_t Address, const void *Decoder);
445 static DecodeStatus DecodeIT(MCInst &Inst, unsigned Val,
446                                 uint64_t Address, const void *Decoder);
447 static DecodeStatus DecodeT2LDRDPreInstruction(MCInst &Inst,unsigned Insn,
448                                uint64_t Address, const void *Decoder);
449 static DecodeStatus DecodeT2STRDPreInstruction(MCInst &Inst,unsigned Insn,
450                                uint64_t Address, const void *Decoder);
451 static DecodeStatus DecodeT2Adr(MCInst &Inst, unsigned Val,
452                                 uint64_t Address, const void *Decoder);
453 static DecodeStatus DecodeT2LdStPre(MCInst &Inst, unsigned Val,
454                                 uint64_t Address, const void *Decoder);
455 static DecodeStatus DecodeT2ShifterImmOperand(MCInst &Inst, unsigned Val,
456                                 uint64_t Address, const void *Decoder);
457 
458 static DecodeStatus DecodeLDR(MCInst &Inst, unsigned Val,
459                                 uint64_t Address, const void *Decoder);
460 static DecodeStatus DecoderForMRRC2AndMCRR2(MCInst &Inst, unsigned Val,
461                                             uint64_t Address, const void *Decoder);
462 static DecodeStatus DecodeForVMRSandVMSR(MCInst &Inst, unsigned Val,
463                                          uint64_t Address, const void *Decoder);
464 
465 template <bool isSigned, bool isNeg, int size>
466 static DecodeStatus DecodeBFLabelOperand(MCInst &Inst, unsigned val,
467                                          uint64_t Address, const void *Decoder);
468 static DecodeStatus DecodeBFAfterTargetOperand(MCInst &Inst, unsigned val,
469                                                uint64_t Address,
470                                                const void *Decoder);
471 static DecodeStatus DecodePredNoALOperand(MCInst &Inst, unsigned Val,
472                                           uint64_t Address,
473                                           const void *Decoder);
474 static DecodeStatus DecodeLOLoop(MCInst &Inst, unsigned Insn, uint64_t Address,
475                                  const void *Decoder);
476 static DecodeStatus DecodeLongShiftOperand(MCInst &Inst, unsigned Val,
477                                            uint64_t Address,
478                                            const void *Decoder);
479 static DecodeStatus DecodeVSCCLRM(MCInst &Inst, unsigned Insn, uint64_t Address,
480                                   const void *Decoder);
481 static DecodeStatus DecodeVPTMaskOperand(MCInst &Inst, unsigned Val,
482                                          uint64_t Address, const void *Decoder);
483 static DecodeStatus DecodeVpredROperand(MCInst &Inst, unsigned Val,
484                                         uint64_t Address, const void *Decoder);
485 static DecodeStatus DecodeRestrictedIPredicateOperand(MCInst &Inst, unsigned Val,
486                                                      uint64_t Address,
487                                                      const void *Decoder);
488 static DecodeStatus DecodeRestrictedSPredicateOperand(MCInst &Inst, unsigned Val,
489                                                      uint64_t Address,
490                                                      const void *Decoder);
491 static DecodeStatus DecodeRestrictedUPredicateOperand(MCInst &Inst, unsigned Val,
492                                                      uint64_t Address,
493                                                      const void *Decoder);
494 static DecodeStatus DecodeRestrictedFPPredicateOperand(MCInst &Inst,
495                                                        unsigned Val,
496                                                        uint64_t Address,
497                                                        const void *Decoder);
498 template<bool Writeback>
499 static DecodeStatus DecodeVSTRVLDR_SYSREG(MCInst &Inst, unsigned Insn,
500                                           uint64_t Address,
501                                           const void *Decoder);
502 template <int shift>
503 static DecodeStatus DecodeExpandedImmOperand(MCInst &Inst, unsigned Val,
504                                              uint64_t Address,
505                                              const void *Decoder);
506 static DecodeStatus DecodeMVEOverlappingLongShift(MCInst &Inst, unsigned Insn,
507                                                   uint64_t Address,
508                                                   const void *Decoder);
509 #include "ARMGenDisassemblerTables.inc"
510 
511 static MCDisassembler *createARMDisassembler(const Target &T,
512                                              const MCSubtargetInfo &STI,
513                                              MCContext &Ctx) {
514   return new ARMDisassembler(STI, Ctx);
515 }
516 
517 // Post-decoding checks
518 static DecodeStatus checkDecodedInstruction(MCInst &MI, uint64_t &Size,
519                                             uint64_t Address, raw_ostream &OS,
520                                             raw_ostream &CS,
521                                             uint32_t Insn,
522                                             DecodeStatus Result) {
523   switch (MI.getOpcode()) {
524     case ARM::HVC: {
525       // HVC is undefined if condition = 0xf otherwise upredictable
526       // if condition != 0xe
527       uint32_t Cond = (Insn >> 28) & 0xF;
528       if (Cond == 0xF)
529         return MCDisassembler::Fail;
530       if (Cond != 0xE)
531         return MCDisassembler::SoftFail;
532       return Result;
533     }
534     case ARM::t2ADDri:
535     case ARM::t2ADDri12:
536     case ARM::t2ADDrr:
537     case ARM::t2ADDrs:
538     case ARM::t2SUBri:
539     case ARM::t2SUBri12:
540     case ARM::t2SUBrr:
541     case ARM::t2SUBrs:
542       if (MI.getOperand(0).getReg() == ARM::SP &&
543           MI.getOperand(1).getReg() != ARM::SP)
544         return MCDisassembler::SoftFail;
545       return Result;
546     default: return Result;
547   }
548 }
549 
550 DecodeStatus ARMDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
551                                              ArrayRef<uint8_t> Bytes,
552                                              uint64_t Address, raw_ostream &OS,
553                                              raw_ostream &CS) const {
554   if (STI.getFeatureBits()[ARM::ModeThumb])
555     return getThumbInstruction(MI, Size, Bytes, Address, OS, CS);
556   return getARMInstruction(MI, Size, Bytes, Address, OS, CS);
557 }
558 
559 DecodeStatus ARMDisassembler::getARMInstruction(MCInst &MI, uint64_t &Size,
560                                                 ArrayRef<uint8_t> Bytes,
561                                                 uint64_t Address,
562                                                 raw_ostream &OS,
563                                                 raw_ostream &CS) const {
564   CommentStream = &CS;
565 
566   assert(!STI.getFeatureBits()[ARM::ModeThumb] &&
567          "Asked to disassemble an ARM instruction but Subtarget is in Thumb "
568          "mode!");
569 
570   // We want to read exactly 4 bytes of data.
571   if (Bytes.size() < 4) {
572     Size = 0;
573     return MCDisassembler::Fail;
574   }
575 
576   // Encoded as a small-endian 32-bit word in the stream.
577   uint32_t Insn =
578       (Bytes[3] << 24) | (Bytes[2] << 16) | (Bytes[1] << 8) | (Bytes[0] << 0);
579 
580   // Calling the auto-generated decoder function.
581   DecodeStatus Result =
582       decodeInstruction(DecoderTableARM32, MI, Insn, Address, this, STI);
583   if (Result != MCDisassembler::Fail) {
584     Size = 4;
585     return checkDecodedInstruction(MI, Size, Address, OS, CS, Insn, Result);
586   }
587 
588   struct DecodeTable {
589     const uint8_t *P;
590     bool DecodePred;
591   };
592 
593   const DecodeTable Tables[] = {
594       {DecoderTableVFP32, false},      {DecoderTableVFPV832, false},
595       {DecoderTableNEONData32, true},  {DecoderTableNEONLoadStore32, true},
596       {DecoderTableNEONDup32, true},   {DecoderTablev8NEON32, false},
597       {DecoderTablev8Crypto32, false},
598   };
599 
600   for (auto Table : Tables) {
601     Result = decodeInstruction(Table.P, MI, Insn, Address, this, STI);
602     if (Result != MCDisassembler::Fail) {
603       Size = 4;
604       // Add a fake predicate operand, because we share these instruction
605       // definitions with Thumb2 where these instructions are predicable.
606       if (Table.DecodePred && !DecodePredicateOperand(MI, 0xE, Address, this))
607         return MCDisassembler::Fail;
608       return Result;
609     }
610   }
611 
612   Result =
613       decodeInstruction(DecoderTableCoProc32, MI, Insn, Address, this, STI);
614   if (Result != MCDisassembler::Fail) {
615     Size = 4;
616     return checkDecodedInstruction(MI, Size, Address, OS, CS, Insn, Result);
617   }
618 
619   Size = 4;
620   return MCDisassembler::Fail;
621 }
622 
623 namespace llvm {
624 
625 extern const MCInstrDesc ARMInsts[];
626 
627 } // end namespace llvm
628 
629 /// tryAddingSymbolicOperand - trys to add a symbolic operand in place of the
630 /// immediate Value in the MCInst.  The immediate Value has had any PC
631 /// adjustment made by the caller.  If the instruction is a branch instruction
632 /// then isBranch is true, else false.  If the getOpInfo() function was set as
633 /// part of the setupForSymbolicDisassembly() call then that function is called
634 /// to get any symbolic information at the Address for this instruction.  If
635 /// that returns non-zero then the symbolic information it returns is used to
636 /// create an MCExpr and that is added as an operand to the MCInst.  If
637 /// getOpInfo() returns zero and isBranch is true then a symbol look up for
638 /// Value is done and if a symbol is found an MCExpr is created with that, else
639 /// an MCExpr with Value is created.  This function returns true if it adds an
640 /// operand to the MCInst and false otherwise.
641 static bool tryAddingSymbolicOperand(uint64_t Address, int32_t Value,
642                                      bool isBranch, uint64_t InstSize,
643                                      MCInst &MI, const void *Decoder) {
644   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
645   // FIXME: Does it make sense for value to be negative?
646   return Dis->tryAddingSymbolicOperand(MI, (uint32_t)Value, Address, isBranch,
647                                        /* Offset */ 0, InstSize);
648 }
649 
650 /// tryAddingPcLoadReferenceComment - trys to add a comment as to what is being
651 /// referenced by a load instruction with the base register that is the Pc.
652 /// These can often be values in a literal pool near the Address of the
653 /// instruction.  The Address of the instruction and its immediate Value are
654 /// used as a possible literal pool entry.  The SymbolLookUp call back will
655 /// return the name of a symbol referenced by the literal pool's entry if
656 /// the referenced address is that of a symbol.  Or it will return a pointer to
657 /// a literal 'C' string if the referenced address of the literal pool's entry
658 /// is an address into a section with 'C' string literals.
659 static void tryAddingPcLoadReferenceComment(uint64_t Address, int Value,
660                                             const void *Decoder) {
661   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
662   Dis->tryAddingPcLoadReferenceComment(Value, Address);
663 }
664 
665 // Thumb1 instructions don't have explicit S bits.  Rather, they
666 // implicitly set CPSR.  Since it's not represented in the encoding, the
667 // auto-generated decoder won't inject the CPSR operand.  We need to fix
668 // that as a post-pass.
669 static void AddThumb1SBit(MCInst &MI, bool InITBlock) {
670   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
671   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
672   MCInst::iterator I = MI.begin();
673   for (unsigned i = 0; i < NumOps; ++i, ++I) {
674     if (I == MI.end()) break;
675     if (OpInfo[i].isOptionalDef() && OpInfo[i].RegClass == ARM::CCRRegClassID) {
676       if (i > 0 && OpInfo[i-1].isPredicate()) continue;
677       MI.insert(I, MCOperand::createReg(InITBlock ? 0 : ARM::CPSR));
678       return;
679     }
680   }
681 
682   MI.insert(I, MCOperand::createReg(InITBlock ? 0 : ARM::CPSR));
683 }
684 
685 static bool isVectorPredicable(unsigned Opcode) {
686   const MCOperandInfo *OpInfo = ARMInsts[Opcode].OpInfo;
687   unsigned short NumOps = ARMInsts[Opcode].NumOperands;
688   for (unsigned i = 0; i < NumOps; ++i) {
689     if (ARM::isVpred(OpInfo[i].OperandType))
690       return true;
691   }
692   return false;
693 }
694 
695 // Most Thumb instructions don't have explicit predicates in the
696 // encoding, but rather get their predicates from IT context.  We need
697 // to fix up the predicate operands using this context information as a
698 // post-pass.
699 MCDisassembler::DecodeStatus
700 ARMDisassembler::AddThumbPredicate(MCInst &MI) const {
701   MCDisassembler::DecodeStatus S = Success;
702 
703   const FeatureBitset &FeatureBits = getSubtargetInfo().getFeatureBits();
704 
705   // A few instructions actually have predicates encoded in them.  Don't
706   // try to overwrite it if we're seeing one of those.
707   switch (MI.getOpcode()) {
708     case ARM::tBcc:
709     case ARM::t2Bcc:
710     case ARM::tCBZ:
711     case ARM::tCBNZ:
712     case ARM::tCPS:
713     case ARM::t2CPS3p:
714     case ARM::t2CPS2p:
715     case ARM::t2CPS1p:
716     case ARM::t2CSEL:
717     case ARM::t2CSINC:
718     case ARM::t2CSINV:
719     case ARM::t2CSNEG:
720     case ARM::tMOVSr:
721     case ARM::tSETEND:
722       // Some instructions (mostly conditional branches) are not
723       // allowed in IT blocks.
724       if (ITBlock.instrInITBlock())
725         S = SoftFail;
726       else
727         return Success;
728       break;
729     case ARM::t2HINT:
730       if (MI.getOperand(0).getImm() == 0x10 && (FeatureBits[ARM::FeatureRAS]) != 0)
731         S = SoftFail;
732       break;
733     case ARM::tB:
734     case ARM::t2B:
735     case ARM::t2TBB:
736     case ARM::t2TBH:
737       // Some instructions (mostly unconditional branches) can
738       // only appears at the end of, or outside of, an IT.
739       if (ITBlock.instrInITBlock() && !ITBlock.instrLastInITBlock())
740         S = SoftFail;
741       break;
742     default:
743       break;
744   }
745 
746   // Warn on non-VPT predicable instruction in a VPT block and a VPT
747   // predicable instruction in an IT block
748   if ((!isVectorPredicable(MI.getOpcode()) && VPTBlock.instrInVPTBlock()) ||
749        (isVectorPredicable(MI.getOpcode()) && ITBlock.instrInITBlock()))
750     S = SoftFail;
751 
752   // If we're in an IT/VPT block, base the predicate on that.  Otherwise,
753   // assume a predicate of AL.
754   unsigned CC = ARMCC::AL;
755   unsigned VCC = ARMVCC::None;
756   if (ITBlock.instrInITBlock()) {
757     CC = ITBlock.getITCC();
758     ITBlock.advanceITState();
759   } else if (VPTBlock.instrInVPTBlock()) {
760     VCC = VPTBlock.getVPTPred();
761     VPTBlock.advanceVPTState();
762   }
763 
764   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
765   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
766 
767   MCInst::iterator CCI = MI.begin();
768   for (unsigned i = 0; i < NumOps; ++i, ++CCI) {
769     if (OpInfo[i].isPredicate() || CCI == MI.end()) break;
770   }
771 
772   if (ARMInsts[MI.getOpcode()].isPredicable()) {
773     CCI = MI.insert(CCI, MCOperand::createImm(CC));
774     ++CCI;
775     if (CC == ARMCC::AL)
776       MI.insert(CCI, MCOperand::createReg(0));
777     else
778       MI.insert(CCI, MCOperand::createReg(ARM::CPSR));
779   } else if (CC != ARMCC::AL) {
780     Check(S, SoftFail);
781   }
782 
783   MCInst::iterator VCCI = MI.begin();
784   unsigned VCCPos;
785   for (VCCPos = 0; VCCPos < NumOps; ++VCCPos, ++VCCI) {
786     if (ARM::isVpred(OpInfo[VCCPos].OperandType) || VCCI == MI.end()) break;
787   }
788 
789   if (isVectorPredicable(MI.getOpcode())) {
790     VCCI = MI.insert(VCCI, MCOperand::createImm(VCC));
791     ++VCCI;
792     if (VCC == ARMVCC::None)
793       MI.insert(VCCI, MCOperand::createReg(0));
794     else
795       MI.insert(VCCI, MCOperand::createReg(ARM::P0));
796     if (OpInfo[VCCPos].OperandType == ARM::OPERAND_VPRED_R) {
797       int TiedOp = ARMInsts[MI.getOpcode()].getOperandConstraint(
798         VCCPos + 2, MCOI::TIED_TO);
799       assert(TiedOp >= 0 &&
800              "Inactive register in vpred_r is not tied to an output!");
801       MI.insert(VCCI, MI.getOperand(TiedOp));
802     }
803   } else if (VCC != ARMVCC::None) {
804     Check(S, SoftFail);
805   }
806 
807   return S;
808 }
809 
810 // Thumb VFP instructions are a special case.  Because we share their
811 // encodings between ARM and Thumb modes, and they are predicable in ARM
812 // mode, the auto-generated decoder will give them an (incorrect)
813 // predicate operand.  We need to rewrite these operands based on the IT
814 // context as a post-pass.
815 void ARMDisassembler::UpdateThumbVFPPredicate(
816   DecodeStatus &S, MCInst &MI) const {
817   unsigned CC;
818   CC = ITBlock.getITCC();
819   if (CC == 0xF)
820     CC = ARMCC::AL;
821   if (ITBlock.instrInITBlock())
822     ITBlock.advanceITState();
823   else if (VPTBlock.instrInVPTBlock()) {
824     CC = VPTBlock.getVPTPred();
825     VPTBlock.advanceVPTState();
826   }
827 
828   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
829   MCInst::iterator I = MI.begin();
830   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
831   for (unsigned i = 0; i < NumOps; ++i, ++I) {
832     if (OpInfo[i].isPredicate() ) {
833       if (CC != ARMCC::AL && !ARMInsts[MI.getOpcode()].isPredicable())
834         Check(S, SoftFail);
835       I->setImm(CC);
836       ++I;
837       if (CC == ARMCC::AL)
838         I->setReg(0);
839       else
840         I->setReg(ARM::CPSR);
841       return;
842     }
843   }
844 }
845 
846 DecodeStatus ARMDisassembler::getThumbInstruction(MCInst &MI, uint64_t &Size,
847                                                   ArrayRef<uint8_t> Bytes,
848                                                   uint64_t Address,
849                                                   raw_ostream &OS,
850                                                   raw_ostream &CS) const {
851   CommentStream = &CS;
852 
853   assert(STI.getFeatureBits()[ARM::ModeThumb] &&
854          "Asked to disassemble in Thumb mode but Subtarget is in ARM mode!");
855 
856   // We want to read exactly 2 bytes of data.
857   if (Bytes.size() < 2) {
858     Size = 0;
859     return MCDisassembler::Fail;
860   }
861 
862   uint16_t Insn16 = (Bytes[1] << 8) | Bytes[0];
863   DecodeStatus Result =
864       decodeInstruction(DecoderTableThumb16, MI, Insn16, Address, this, STI);
865   if (Result != MCDisassembler::Fail) {
866     Size = 2;
867     Check(Result, AddThumbPredicate(MI));
868     return Result;
869   }
870 
871   Result = decodeInstruction(DecoderTableThumbSBit16, MI, Insn16, Address, this,
872                              STI);
873   if (Result) {
874     Size = 2;
875     bool InITBlock = ITBlock.instrInITBlock();
876     Check(Result, AddThumbPredicate(MI));
877     AddThumb1SBit(MI, InITBlock);
878     return Result;
879   }
880 
881   Result =
882       decodeInstruction(DecoderTableThumb216, MI, Insn16, Address, this, STI);
883   if (Result != MCDisassembler::Fail) {
884     Size = 2;
885 
886     // Nested IT blocks are UNPREDICTABLE.  Must be checked before we add
887     // the Thumb predicate.
888     if (MI.getOpcode() == ARM::t2IT && ITBlock.instrInITBlock())
889       Result = MCDisassembler::SoftFail;
890 
891     Check(Result, AddThumbPredicate(MI));
892 
893     // If we find an IT instruction, we need to parse its condition
894     // code and mask operands so that we can apply them correctly
895     // to the subsequent instructions.
896     if (MI.getOpcode() == ARM::t2IT) {
897       unsigned Firstcond = MI.getOperand(0).getImm();
898       unsigned Mask = MI.getOperand(1).getImm();
899       ITBlock.setITState(Firstcond, Mask);
900 
901       // An IT instruction that would give a 'NV' predicate is unpredictable.
902       if (Firstcond == ARMCC::AL && !isPowerOf2_32(Mask))
903         CS << "unpredictable IT predicate sequence";
904     }
905 
906     return Result;
907   }
908 
909   // We want to read exactly 4 bytes of data.
910   if (Bytes.size() < 4) {
911     Size = 0;
912     return MCDisassembler::Fail;
913   }
914 
915   uint32_t Insn32 =
916       (Bytes[3] << 8) | (Bytes[2] << 0) | (Bytes[1] << 24) | (Bytes[0] << 16);
917 
918   Result =
919       decodeInstruction(DecoderTableMVE32, MI, Insn32, Address, this, STI);
920   if (Result != MCDisassembler::Fail) {
921     Size = 4;
922 
923     // Nested VPT blocks are UNPREDICTABLE. Must be checked before we add
924     // the VPT predicate.
925     if (isVPTOpcode(MI.getOpcode()) && VPTBlock.instrInVPTBlock())
926       Result = MCDisassembler::SoftFail;
927 
928     Check(Result, AddThumbPredicate(MI));
929 
930     if (isVPTOpcode(MI.getOpcode())) {
931       unsigned Mask = MI.getOperand(0).getImm();
932       VPTBlock.setVPTState(Mask);
933     }
934 
935     return Result;
936   }
937 
938   Result =
939       decodeInstruction(DecoderTableThumb32, MI, Insn32, Address, this, STI);
940   if (Result != MCDisassembler::Fail) {
941     Size = 4;
942     bool InITBlock = ITBlock.instrInITBlock();
943     Check(Result, AddThumbPredicate(MI));
944     AddThumb1SBit(MI, InITBlock);
945     return Result;
946   }
947 
948   Result =
949       decodeInstruction(DecoderTableThumb232, MI, Insn32, Address, this, STI);
950   if (Result != MCDisassembler::Fail) {
951     Size = 4;
952     Check(Result, AddThumbPredicate(MI));
953     return checkDecodedInstruction(MI, Size, Address, OS, CS, Insn32, Result);
954   }
955 
956   if (fieldFromInstruction(Insn32, 28, 4) == 0xE) {
957     Result =
958         decodeInstruction(DecoderTableVFP32, MI, Insn32, Address, this, STI);
959     if (Result != MCDisassembler::Fail) {
960       Size = 4;
961       UpdateThumbVFPPredicate(Result, MI);
962       return Result;
963     }
964   }
965 
966   Result =
967       decodeInstruction(DecoderTableVFPV832, MI, Insn32, Address, this, STI);
968   if (Result != MCDisassembler::Fail) {
969     Size = 4;
970     return Result;
971   }
972 
973   if (fieldFromInstruction(Insn32, 28, 4) == 0xE) {
974     Result = decodeInstruction(DecoderTableNEONDup32, MI, Insn32, Address, this,
975                                STI);
976     if (Result != MCDisassembler::Fail) {
977       Size = 4;
978       Check(Result, AddThumbPredicate(MI));
979       return Result;
980     }
981   }
982 
983   if (fieldFromInstruction(Insn32, 24, 8) == 0xF9) {
984     uint32_t NEONLdStInsn = Insn32;
985     NEONLdStInsn &= 0xF0FFFFFF;
986     NEONLdStInsn |= 0x04000000;
987     Result = decodeInstruction(DecoderTableNEONLoadStore32, MI, NEONLdStInsn,
988                                Address, this, STI);
989     if (Result != MCDisassembler::Fail) {
990       Size = 4;
991       Check(Result, AddThumbPredicate(MI));
992       return Result;
993     }
994   }
995 
996   if (fieldFromInstruction(Insn32, 24, 4) == 0xF) {
997     uint32_t NEONDataInsn = Insn32;
998     NEONDataInsn &= 0xF0FFFFFF; // Clear bits 27-24
999     NEONDataInsn |= (NEONDataInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
1000     NEONDataInsn |= 0x12000000; // Set bits 28 and 25
1001     Result = decodeInstruction(DecoderTableNEONData32, MI, NEONDataInsn,
1002                                Address, this, STI);
1003     if (Result != MCDisassembler::Fail) {
1004       Size = 4;
1005       Check(Result, AddThumbPredicate(MI));
1006       return Result;
1007     }
1008 
1009     uint32_t NEONCryptoInsn = Insn32;
1010     NEONCryptoInsn &= 0xF0FFFFFF; // Clear bits 27-24
1011     NEONCryptoInsn |= (NEONCryptoInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
1012     NEONCryptoInsn |= 0x12000000; // Set bits 28 and 25
1013     Result = decodeInstruction(DecoderTablev8Crypto32, MI, NEONCryptoInsn,
1014                                Address, this, STI);
1015     if (Result != MCDisassembler::Fail) {
1016       Size = 4;
1017       return Result;
1018     }
1019 
1020     uint32_t NEONv8Insn = Insn32;
1021     NEONv8Insn &= 0xF3FFFFFF; // Clear bits 27-26
1022     Result = decodeInstruction(DecoderTablev8NEON32, MI, NEONv8Insn, Address,
1023                                this, STI);
1024     if (Result != MCDisassembler::Fail) {
1025       Size = 4;
1026       return Result;
1027     }
1028   }
1029 
1030   Result =
1031       decodeInstruction(DecoderTableThumb2CoProc32, MI, Insn32, Address, this, STI);
1032   if (Result != MCDisassembler::Fail) {
1033     Size = 4;
1034     Check(Result, AddThumbPredicate(MI));
1035     return Result;
1036   }
1037 
1038   Size = 0;
1039   return MCDisassembler::Fail;
1040 }
1041 
1042 extern "C" void LLVMInitializeARMDisassembler() {
1043   TargetRegistry::RegisterMCDisassembler(getTheARMLETarget(),
1044                                          createARMDisassembler);
1045   TargetRegistry::RegisterMCDisassembler(getTheARMBETarget(),
1046                                          createARMDisassembler);
1047   TargetRegistry::RegisterMCDisassembler(getTheThumbLETarget(),
1048                                          createARMDisassembler);
1049   TargetRegistry::RegisterMCDisassembler(getTheThumbBETarget(),
1050                                          createARMDisassembler);
1051 }
1052 
1053 static const uint16_t GPRDecoderTable[] = {
1054   ARM::R0, ARM::R1, ARM::R2, ARM::R3,
1055   ARM::R4, ARM::R5, ARM::R6, ARM::R7,
1056   ARM::R8, ARM::R9, ARM::R10, ARM::R11,
1057   ARM::R12, ARM::SP, ARM::LR, ARM::PC
1058 };
1059 
1060 static const uint16_t CLRMGPRDecoderTable[] = {
1061   ARM::R0, ARM::R1, ARM::R2, ARM::R3,
1062   ARM::R4, ARM::R5, ARM::R6, ARM::R7,
1063   ARM::R8, ARM::R9, ARM::R10, ARM::R11,
1064   ARM::R12, 0, ARM::LR, ARM::APSR
1065 };
1066 
1067 static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1068                                    uint64_t Address, const void *Decoder) {
1069   if (RegNo > 15)
1070     return MCDisassembler::Fail;
1071 
1072   unsigned Register = GPRDecoderTable[RegNo];
1073   Inst.addOperand(MCOperand::createReg(Register));
1074   return MCDisassembler::Success;
1075 }
1076 
1077 static DecodeStatus DecodeCLRMGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1078                                                uint64_t Address,
1079                                                const void *Decoder) {
1080   if (RegNo > 15)
1081     return MCDisassembler::Fail;
1082 
1083   unsigned Register = CLRMGPRDecoderTable[RegNo];
1084   if (Register == 0)
1085     return MCDisassembler::Fail;
1086 
1087   Inst.addOperand(MCOperand::createReg(Register));
1088   return MCDisassembler::Success;
1089 }
1090 
1091 static DecodeStatus
1092 DecodeGPRnopcRegisterClass(MCInst &Inst, unsigned RegNo,
1093                            uint64_t Address, const void *Decoder) {
1094   DecodeStatus S = MCDisassembler::Success;
1095 
1096   if (RegNo == 15)
1097     S = MCDisassembler::SoftFail;
1098 
1099   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1100 
1101   return S;
1102 }
1103 
1104 static DecodeStatus
1105 DecodeGPRwithAPSRRegisterClass(MCInst &Inst, unsigned RegNo,
1106                                uint64_t Address, const void *Decoder) {
1107   DecodeStatus S = MCDisassembler::Success;
1108 
1109   if (RegNo == 15)
1110   {
1111     Inst.addOperand(MCOperand::createReg(ARM::APSR_NZCV));
1112     return MCDisassembler::Success;
1113   }
1114 
1115   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1116   return S;
1117 }
1118 
1119 static DecodeStatus
1120 DecodeGPRwithZRRegisterClass(MCInst &Inst, unsigned RegNo,
1121                              uint64_t Address, const void *Decoder) {
1122   DecodeStatus S = MCDisassembler::Success;
1123 
1124   if (RegNo == 15)
1125   {
1126     Inst.addOperand(MCOperand::createReg(ARM::ZR));
1127     return MCDisassembler::Success;
1128   }
1129 
1130   if (RegNo == 13)
1131     S = MCDisassembler::SoftFail;
1132 
1133   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1134   return S;
1135 }
1136 
1137 static DecodeStatus DecodetGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1138                                    uint64_t Address, const void *Decoder) {
1139   if (RegNo > 7)
1140     return MCDisassembler::Fail;
1141   return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
1142 }
1143 
1144 static const uint16_t GPRPairDecoderTable[] = {
1145   ARM::R0_R1, ARM::R2_R3,   ARM::R4_R5,  ARM::R6_R7,
1146   ARM::R8_R9, ARM::R10_R11, ARM::R12_SP
1147 };
1148 
1149 static DecodeStatus DecodeGPRPairRegisterClass(MCInst &Inst, unsigned RegNo,
1150                                    uint64_t Address, const void *Decoder) {
1151   DecodeStatus S = MCDisassembler::Success;
1152 
1153   if (RegNo > 13)
1154     return MCDisassembler::Fail;
1155 
1156   if ((RegNo & 1) || RegNo == 0xe)
1157      S = MCDisassembler::SoftFail;
1158 
1159   unsigned RegisterPair = GPRPairDecoderTable[RegNo/2];
1160   Inst.addOperand(MCOperand::createReg(RegisterPair));
1161   return S;
1162 }
1163 
1164 static DecodeStatus DecodetcGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1165                                    uint64_t Address, const void *Decoder) {
1166   unsigned Register = 0;
1167   switch (RegNo) {
1168     case 0:
1169       Register = ARM::R0;
1170       break;
1171     case 1:
1172       Register = ARM::R1;
1173       break;
1174     case 2:
1175       Register = ARM::R2;
1176       break;
1177     case 3:
1178       Register = ARM::R3;
1179       break;
1180     case 9:
1181       Register = ARM::R9;
1182       break;
1183     case 12:
1184       Register = ARM::R12;
1185       break;
1186     default:
1187       return MCDisassembler::Fail;
1188     }
1189 
1190   Inst.addOperand(MCOperand::createReg(Register));
1191   return MCDisassembler::Success;
1192 }
1193 
1194 static DecodeStatus DecoderGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1195                                    uint64_t Address, const void *Decoder) {
1196   DecodeStatus S = MCDisassembler::Success;
1197 
1198   const FeatureBitset &featureBits =
1199     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1200 
1201   if ((RegNo == 13 && !featureBits[ARM::HasV8Ops]) || RegNo == 15)
1202     S = MCDisassembler::SoftFail;
1203 
1204   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1205   return S;
1206 }
1207 
1208 static const uint16_t SPRDecoderTable[] = {
1209      ARM::S0,  ARM::S1,  ARM::S2,  ARM::S3,
1210      ARM::S4,  ARM::S5,  ARM::S6,  ARM::S7,
1211      ARM::S8,  ARM::S9, ARM::S10, ARM::S11,
1212     ARM::S12, ARM::S13, ARM::S14, ARM::S15,
1213     ARM::S16, ARM::S17, ARM::S18, ARM::S19,
1214     ARM::S20, ARM::S21, ARM::S22, ARM::S23,
1215     ARM::S24, ARM::S25, ARM::S26, ARM::S27,
1216     ARM::S28, ARM::S29, ARM::S30, ARM::S31
1217 };
1218 
1219 static DecodeStatus DecodeSPRRegisterClass(MCInst &Inst, unsigned RegNo,
1220                                    uint64_t Address, const void *Decoder) {
1221   if (RegNo > 31)
1222     return MCDisassembler::Fail;
1223 
1224   unsigned Register = SPRDecoderTable[RegNo];
1225   Inst.addOperand(MCOperand::createReg(Register));
1226   return MCDisassembler::Success;
1227 }
1228 
1229 static DecodeStatus DecodeHPRRegisterClass(MCInst &Inst, unsigned RegNo,
1230                                    uint64_t Address, const void *Decoder) {
1231   return DecodeSPRRegisterClass(Inst, RegNo, Address, Decoder);
1232 }
1233 
1234 static const uint16_t DPRDecoderTable[] = {
1235      ARM::D0,  ARM::D1,  ARM::D2,  ARM::D3,
1236      ARM::D4,  ARM::D5,  ARM::D6,  ARM::D7,
1237      ARM::D8,  ARM::D9, ARM::D10, ARM::D11,
1238     ARM::D12, ARM::D13, ARM::D14, ARM::D15,
1239     ARM::D16, ARM::D17, ARM::D18, ARM::D19,
1240     ARM::D20, ARM::D21, ARM::D22, ARM::D23,
1241     ARM::D24, ARM::D25, ARM::D26, ARM::D27,
1242     ARM::D28, ARM::D29, ARM::D30, ARM::D31
1243 };
1244 
1245 static DecodeStatus DecodeDPRRegisterClass(MCInst &Inst, unsigned RegNo,
1246                                    uint64_t Address, const void *Decoder) {
1247   const FeatureBitset &featureBits =
1248     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1249 
1250   bool hasD32 = featureBits[ARM::FeatureD32];
1251 
1252   if (RegNo > 31 || (!hasD32 && RegNo > 15))
1253     return MCDisassembler::Fail;
1254 
1255   unsigned Register = DPRDecoderTable[RegNo];
1256   Inst.addOperand(MCOperand::createReg(Register));
1257   return MCDisassembler::Success;
1258 }
1259 
1260 static DecodeStatus DecodeDPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
1261                                    uint64_t Address, const void *Decoder) {
1262   if (RegNo > 7)
1263     return MCDisassembler::Fail;
1264   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
1265 }
1266 
1267 static DecodeStatus DecodeSPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
1268                                    uint64_t Address, const void *Decoder) {
1269   if (RegNo > 15)
1270     return MCDisassembler::Fail;
1271   return DecodeSPRRegisterClass(Inst, RegNo, Address, Decoder);
1272 }
1273 
1274 static DecodeStatus
1275 DecodeDPR_VFP2RegisterClass(MCInst &Inst, unsigned RegNo,
1276                             uint64_t Address, const void *Decoder) {
1277   if (RegNo > 15)
1278     return MCDisassembler::Fail;
1279   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
1280 }
1281 
1282 static const uint16_t QPRDecoderTable[] = {
1283      ARM::Q0,  ARM::Q1,  ARM::Q2,  ARM::Q3,
1284      ARM::Q4,  ARM::Q5,  ARM::Q6,  ARM::Q7,
1285      ARM::Q8,  ARM::Q9, ARM::Q10, ARM::Q11,
1286     ARM::Q12, ARM::Q13, ARM::Q14, ARM::Q15
1287 };
1288 
1289 static DecodeStatus DecodeQPRRegisterClass(MCInst &Inst, unsigned RegNo,
1290                                    uint64_t Address, const void *Decoder) {
1291   if (RegNo > 31 || (RegNo & 1) != 0)
1292     return MCDisassembler::Fail;
1293   RegNo >>= 1;
1294 
1295   unsigned Register = QPRDecoderTable[RegNo];
1296   Inst.addOperand(MCOperand::createReg(Register));
1297   return MCDisassembler::Success;
1298 }
1299 
1300 static const uint16_t DPairDecoderTable[] = {
1301   ARM::Q0,  ARM::D1_D2,   ARM::Q1,  ARM::D3_D4,   ARM::Q2,  ARM::D5_D6,
1302   ARM::Q3,  ARM::D7_D8,   ARM::Q4,  ARM::D9_D10,  ARM::Q5,  ARM::D11_D12,
1303   ARM::Q6,  ARM::D13_D14, ARM::Q7,  ARM::D15_D16, ARM::Q8,  ARM::D17_D18,
1304   ARM::Q9,  ARM::D19_D20, ARM::Q10, ARM::D21_D22, ARM::Q11, ARM::D23_D24,
1305   ARM::Q12, ARM::D25_D26, ARM::Q13, ARM::D27_D28, ARM::Q14, ARM::D29_D30,
1306   ARM::Q15
1307 };
1308 
1309 static DecodeStatus DecodeDPairRegisterClass(MCInst &Inst, unsigned RegNo,
1310                                    uint64_t Address, const void *Decoder) {
1311   if (RegNo > 30)
1312     return MCDisassembler::Fail;
1313 
1314   unsigned Register = DPairDecoderTable[RegNo];
1315   Inst.addOperand(MCOperand::createReg(Register));
1316   return MCDisassembler::Success;
1317 }
1318 
1319 static const uint16_t DPairSpacedDecoderTable[] = {
1320   ARM::D0_D2,   ARM::D1_D3,   ARM::D2_D4,   ARM::D3_D5,
1321   ARM::D4_D6,   ARM::D5_D7,   ARM::D6_D8,   ARM::D7_D9,
1322   ARM::D8_D10,  ARM::D9_D11,  ARM::D10_D12, ARM::D11_D13,
1323   ARM::D12_D14, ARM::D13_D15, ARM::D14_D16, ARM::D15_D17,
1324   ARM::D16_D18, ARM::D17_D19, ARM::D18_D20, ARM::D19_D21,
1325   ARM::D20_D22, ARM::D21_D23, ARM::D22_D24, ARM::D23_D25,
1326   ARM::D24_D26, ARM::D25_D27, ARM::D26_D28, ARM::D27_D29,
1327   ARM::D28_D30, ARM::D29_D31
1328 };
1329 
1330 static DecodeStatus DecodeDPairSpacedRegisterClass(MCInst &Inst,
1331                                                    unsigned RegNo,
1332                                                    uint64_t Address,
1333                                                    const void *Decoder) {
1334   if (RegNo > 29)
1335     return MCDisassembler::Fail;
1336 
1337   unsigned Register = DPairSpacedDecoderTable[RegNo];
1338   Inst.addOperand(MCOperand::createReg(Register));
1339   return MCDisassembler::Success;
1340 }
1341 
1342 static DecodeStatus DecodePredicateOperand(MCInst &Inst, unsigned Val,
1343                                uint64_t Address, const void *Decoder) {
1344   DecodeStatus S = MCDisassembler::Success;
1345   if (Val == 0xF) return MCDisassembler::Fail;
1346   // AL predicate is not allowed on Thumb1 branches.
1347   if (Inst.getOpcode() == ARM::tBcc && Val == 0xE)
1348     return MCDisassembler::Fail;
1349   if (Val != ARMCC::AL && !ARMInsts[Inst.getOpcode()].isPredicable())
1350     Check(S, MCDisassembler::SoftFail);
1351   Inst.addOperand(MCOperand::createImm(Val));
1352   if (Val == ARMCC::AL) {
1353     Inst.addOperand(MCOperand::createReg(0));
1354   } else
1355     Inst.addOperand(MCOperand::createReg(ARM::CPSR));
1356   return S;
1357 }
1358 
1359 static DecodeStatus DecodeCCOutOperand(MCInst &Inst, unsigned Val,
1360                                uint64_t Address, const void *Decoder) {
1361   if (Val)
1362     Inst.addOperand(MCOperand::createReg(ARM::CPSR));
1363   else
1364     Inst.addOperand(MCOperand::createReg(0));
1365   return MCDisassembler::Success;
1366 }
1367 
1368 static DecodeStatus DecodeSORegImmOperand(MCInst &Inst, unsigned Val,
1369                                uint64_t Address, const void *Decoder) {
1370   DecodeStatus S = MCDisassembler::Success;
1371 
1372   unsigned Rm = fieldFromInstruction(Val, 0, 4);
1373   unsigned type = fieldFromInstruction(Val, 5, 2);
1374   unsigned imm = fieldFromInstruction(Val, 7, 5);
1375 
1376   // Register-immediate
1377   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
1378     return MCDisassembler::Fail;
1379 
1380   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1381   switch (type) {
1382     case 0:
1383       Shift = ARM_AM::lsl;
1384       break;
1385     case 1:
1386       Shift = ARM_AM::lsr;
1387       break;
1388     case 2:
1389       Shift = ARM_AM::asr;
1390       break;
1391     case 3:
1392       Shift = ARM_AM::ror;
1393       break;
1394   }
1395 
1396   if (Shift == ARM_AM::ror && imm == 0)
1397     Shift = ARM_AM::rrx;
1398 
1399   unsigned Op = Shift | (imm << 3);
1400   Inst.addOperand(MCOperand::createImm(Op));
1401 
1402   return S;
1403 }
1404 
1405 static DecodeStatus DecodeSORegRegOperand(MCInst &Inst, unsigned Val,
1406                                uint64_t Address, const void *Decoder) {
1407   DecodeStatus S = MCDisassembler::Success;
1408 
1409   unsigned Rm = fieldFromInstruction(Val, 0, 4);
1410   unsigned type = fieldFromInstruction(Val, 5, 2);
1411   unsigned Rs = fieldFromInstruction(Val, 8, 4);
1412 
1413   // Register-register
1414   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1415     return MCDisassembler::Fail;
1416   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rs, Address, Decoder)))
1417     return MCDisassembler::Fail;
1418 
1419   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1420   switch (type) {
1421     case 0:
1422       Shift = ARM_AM::lsl;
1423       break;
1424     case 1:
1425       Shift = ARM_AM::lsr;
1426       break;
1427     case 2:
1428       Shift = ARM_AM::asr;
1429       break;
1430     case 3:
1431       Shift = ARM_AM::ror;
1432       break;
1433   }
1434 
1435   Inst.addOperand(MCOperand::createImm(Shift));
1436 
1437   return S;
1438 }
1439 
1440 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Val,
1441                                  uint64_t Address, const void *Decoder) {
1442   DecodeStatus S = MCDisassembler::Success;
1443 
1444   bool NeedDisjointWriteback = false;
1445   unsigned WritebackReg = 0;
1446   bool CLRM = false;
1447   switch (Inst.getOpcode()) {
1448   default:
1449     break;
1450   case ARM::LDMIA_UPD:
1451   case ARM::LDMDB_UPD:
1452   case ARM::LDMIB_UPD:
1453   case ARM::LDMDA_UPD:
1454   case ARM::t2LDMIA_UPD:
1455   case ARM::t2LDMDB_UPD:
1456   case ARM::t2STMIA_UPD:
1457   case ARM::t2STMDB_UPD:
1458     NeedDisjointWriteback = true;
1459     WritebackReg = Inst.getOperand(0).getReg();
1460     break;
1461   case ARM::t2CLRM:
1462     CLRM = true;
1463     break;
1464   }
1465 
1466   // Empty register lists are not allowed.
1467   if (Val == 0) return MCDisassembler::Fail;
1468   for (unsigned i = 0; i < 16; ++i) {
1469     if (Val & (1 << i)) {
1470       if (CLRM) {
1471         if (!Check(S, DecodeCLRMGPRRegisterClass(Inst, i, Address, Decoder))) {
1472           return MCDisassembler::Fail;
1473         }
1474       } else {
1475         if (!Check(S, DecodeGPRRegisterClass(Inst, i, Address, Decoder)))
1476           return MCDisassembler::Fail;
1477         // Writeback not allowed if Rn is in the target list.
1478         if (NeedDisjointWriteback && WritebackReg == Inst.end()[-1].getReg())
1479           Check(S, MCDisassembler::SoftFail);
1480       }
1481     }
1482   }
1483 
1484   return S;
1485 }
1486 
1487 static DecodeStatus DecodeSPRRegListOperand(MCInst &Inst, unsigned Val,
1488                                  uint64_t Address, const void *Decoder) {
1489   DecodeStatus S = MCDisassembler::Success;
1490 
1491   unsigned Vd = fieldFromInstruction(Val, 8, 5);
1492   unsigned regs = fieldFromInstruction(Val, 0, 8);
1493 
1494   // In case of unpredictable encoding, tweak the operands.
1495   if (regs == 0 || (Vd + regs) > 32) {
1496     regs = Vd + regs > 32 ? 32 - Vd : regs;
1497     regs = std::max( 1u, regs);
1498     S = MCDisassembler::SoftFail;
1499   }
1500 
1501   if (!Check(S, DecodeSPRRegisterClass(Inst, Vd, Address, Decoder)))
1502     return MCDisassembler::Fail;
1503   for (unsigned i = 0; i < (regs - 1); ++i) {
1504     if (!Check(S, DecodeSPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1505       return MCDisassembler::Fail;
1506   }
1507 
1508   return S;
1509 }
1510 
1511 static DecodeStatus DecodeDPRRegListOperand(MCInst &Inst, unsigned Val,
1512                                  uint64_t Address, const void *Decoder) {
1513   DecodeStatus S = MCDisassembler::Success;
1514 
1515   unsigned Vd = fieldFromInstruction(Val, 8, 5);
1516   unsigned regs = fieldFromInstruction(Val, 1, 7);
1517 
1518   // In case of unpredictable encoding, tweak the operands.
1519   if (regs == 0 || regs > 16 || (Vd + regs) > 32) {
1520     regs = Vd + regs > 32 ? 32 - Vd : regs;
1521     regs = std::max( 1u, regs);
1522     regs = std::min(16u, regs);
1523     S = MCDisassembler::SoftFail;
1524   }
1525 
1526   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
1527       return MCDisassembler::Fail;
1528   for (unsigned i = 0; i < (regs - 1); ++i) {
1529     if (!Check(S, DecodeDPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1530       return MCDisassembler::Fail;
1531   }
1532 
1533   return S;
1534 }
1535 
1536 static DecodeStatus DecodeBitfieldMaskOperand(MCInst &Inst, unsigned Val,
1537                                       uint64_t Address, const void *Decoder) {
1538   // This operand encodes a mask of contiguous zeros between a specified MSB
1539   // and LSB.  To decode it, we create the mask of all bits MSB-and-lower,
1540   // the mask of all bits LSB-and-lower, and then xor them to create
1541   // the mask of that's all ones on [msb, lsb].  Finally we not it to
1542   // create the final mask.
1543   unsigned msb = fieldFromInstruction(Val, 5, 5);
1544   unsigned lsb = fieldFromInstruction(Val, 0, 5);
1545 
1546   DecodeStatus S = MCDisassembler::Success;
1547   if (lsb > msb) {
1548     Check(S, MCDisassembler::SoftFail);
1549     // The check above will cause the warning for the "potentially undefined
1550     // instruction encoding" but we can't build a bad MCOperand value here
1551     // with a lsb > msb or else printing the MCInst will cause a crash.
1552     lsb = msb;
1553   }
1554 
1555   uint32_t msb_mask = 0xFFFFFFFF;
1556   if (msb != 31) msb_mask = (1U << (msb+1)) - 1;
1557   uint32_t lsb_mask = (1U << lsb) - 1;
1558 
1559   Inst.addOperand(MCOperand::createImm(~(msb_mask ^ lsb_mask)));
1560   return S;
1561 }
1562 
1563 static DecodeStatus DecodeCopMemInstruction(MCInst &Inst, unsigned Insn,
1564                                   uint64_t Address, const void *Decoder) {
1565   DecodeStatus S = MCDisassembler::Success;
1566 
1567   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1568   unsigned CRd = fieldFromInstruction(Insn, 12, 4);
1569   unsigned coproc = fieldFromInstruction(Insn, 8, 4);
1570   unsigned imm = fieldFromInstruction(Insn, 0, 8);
1571   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1572   unsigned U = fieldFromInstruction(Insn, 23, 1);
1573   const FeatureBitset &featureBits =
1574     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1575 
1576   switch (Inst.getOpcode()) {
1577     case ARM::LDC_OFFSET:
1578     case ARM::LDC_PRE:
1579     case ARM::LDC_POST:
1580     case ARM::LDC_OPTION:
1581     case ARM::LDCL_OFFSET:
1582     case ARM::LDCL_PRE:
1583     case ARM::LDCL_POST:
1584     case ARM::LDCL_OPTION:
1585     case ARM::STC_OFFSET:
1586     case ARM::STC_PRE:
1587     case ARM::STC_POST:
1588     case ARM::STC_OPTION:
1589     case ARM::STCL_OFFSET:
1590     case ARM::STCL_PRE:
1591     case ARM::STCL_POST:
1592     case ARM::STCL_OPTION:
1593     case ARM::t2LDC_OFFSET:
1594     case ARM::t2LDC_PRE:
1595     case ARM::t2LDC_POST:
1596     case ARM::t2LDC_OPTION:
1597     case ARM::t2LDCL_OFFSET:
1598     case ARM::t2LDCL_PRE:
1599     case ARM::t2LDCL_POST:
1600     case ARM::t2LDCL_OPTION:
1601     case ARM::t2STC_OFFSET:
1602     case ARM::t2STC_PRE:
1603     case ARM::t2STC_POST:
1604     case ARM::t2STC_OPTION:
1605     case ARM::t2STCL_OFFSET:
1606     case ARM::t2STCL_PRE:
1607     case ARM::t2STCL_POST:
1608     case ARM::t2STCL_OPTION:
1609     case ARM::t2LDC2_OFFSET:
1610     case ARM::t2LDC2L_OFFSET:
1611     case ARM::t2LDC2_PRE:
1612     case ARM::t2LDC2L_PRE:
1613     case ARM::t2STC2_OFFSET:
1614     case ARM::t2STC2L_OFFSET:
1615     case ARM::t2STC2_PRE:
1616     case ARM::t2STC2L_PRE:
1617     case ARM::LDC2_OFFSET:
1618     case ARM::LDC2L_OFFSET:
1619     case ARM::LDC2_PRE:
1620     case ARM::LDC2L_PRE:
1621     case ARM::STC2_OFFSET:
1622     case ARM::STC2L_OFFSET:
1623     case ARM::STC2_PRE:
1624     case ARM::STC2L_PRE:
1625     case ARM::t2LDC2_OPTION:
1626     case ARM::t2STC2_OPTION:
1627     case ARM::t2LDC2_POST:
1628     case ARM::t2LDC2L_POST:
1629     case ARM::t2STC2_POST:
1630     case ARM::t2STC2L_POST:
1631     case ARM::LDC2_POST:
1632     case ARM::LDC2L_POST:
1633     case ARM::STC2_POST:
1634     case ARM::STC2L_POST:
1635       if (coproc == 0xA || coproc == 0xB ||
1636           (featureBits[ARM::HasV8_1MMainlineOps] &&
1637            (coproc == 0x8 || coproc == 0x9 || coproc == 0xA || coproc == 0xB ||
1638             coproc == 0xE || coproc == 0xF)))
1639         return MCDisassembler::Fail;
1640       break;
1641     default:
1642       break;
1643   }
1644 
1645   if (featureBits[ARM::HasV8Ops] && (coproc != 14))
1646     return MCDisassembler::Fail;
1647 
1648   Inst.addOperand(MCOperand::createImm(coproc));
1649   Inst.addOperand(MCOperand::createImm(CRd));
1650   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1651     return MCDisassembler::Fail;
1652 
1653   switch (Inst.getOpcode()) {
1654     case ARM::t2LDC2_OFFSET:
1655     case ARM::t2LDC2L_OFFSET:
1656     case ARM::t2LDC2_PRE:
1657     case ARM::t2LDC2L_PRE:
1658     case ARM::t2STC2_OFFSET:
1659     case ARM::t2STC2L_OFFSET:
1660     case ARM::t2STC2_PRE:
1661     case ARM::t2STC2L_PRE:
1662     case ARM::LDC2_OFFSET:
1663     case ARM::LDC2L_OFFSET:
1664     case ARM::LDC2_PRE:
1665     case ARM::LDC2L_PRE:
1666     case ARM::STC2_OFFSET:
1667     case ARM::STC2L_OFFSET:
1668     case ARM::STC2_PRE:
1669     case ARM::STC2L_PRE:
1670     case ARM::t2LDC_OFFSET:
1671     case ARM::t2LDCL_OFFSET:
1672     case ARM::t2LDC_PRE:
1673     case ARM::t2LDCL_PRE:
1674     case ARM::t2STC_OFFSET:
1675     case ARM::t2STCL_OFFSET:
1676     case ARM::t2STC_PRE:
1677     case ARM::t2STCL_PRE:
1678     case ARM::LDC_OFFSET:
1679     case ARM::LDCL_OFFSET:
1680     case ARM::LDC_PRE:
1681     case ARM::LDCL_PRE:
1682     case ARM::STC_OFFSET:
1683     case ARM::STCL_OFFSET:
1684     case ARM::STC_PRE:
1685     case ARM::STCL_PRE:
1686       imm = ARM_AM::getAM5Opc(U ? ARM_AM::add : ARM_AM::sub, imm);
1687       Inst.addOperand(MCOperand::createImm(imm));
1688       break;
1689     case ARM::t2LDC2_POST:
1690     case ARM::t2LDC2L_POST:
1691     case ARM::t2STC2_POST:
1692     case ARM::t2STC2L_POST:
1693     case ARM::LDC2_POST:
1694     case ARM::LDC2L_POST:
1695     case ARM::STC2_POST:
1696     case ARM::STC2L_POST:
1697     case ARM::t2LDC_POST:
1698     case ARM::t2LDCL_POST:
1699     case ARM::t2STC_POST:
1700     case ARM::t2STCL_POST:
1701     case ARM::LDC_POST:
1702     case ARM::LDCL_POST:
1703     case ARM::STC_POST:
1704     case ARM::STCL_POST:
1705       imm |= U << 8;
1706       LLVM_FALLTHROUGH;
1707     default:
1708       // The 'option' variant doesn't encode 'U' in the immediate since
1709       // the immediate is unsigned [0,255].
1710       Inst.addOperand(MCOperand::createImm(imm));
1711       break;
1712   }
1713 
1714   switch (Inst.getOpcode()) {
1715     case ARM::LDC_OFFSET:
1716     case ARM::LDC_PRE:
1717     case ARM::LDC_POST:
1718     case ARM::LDC_OPTION:
1719     case ARM::LDCL_OFFSET:
1720     case ARM::LDCL_PRE:
1721     case ARM::LDCL_POST:
1722     case ARM::LDCL_OPTION:
1723     case ARM::STC_OFFSET:
1724     case ARM::STC_PRE:
1725     case ARM::STC_POST:
1726     case ARM::STC_OPTION:
1727     case ARM::STCL_OFFSET:
1728     case ARM::STCL_PRE:
1729     case ARM::STCL_POST:
1730     case ARM::STCL_OPTION:
1731       if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1732         return MCDisassembler::Fail;
1733       break;
1734     default:
1735       break;
1736   }
1737 
1738   return S;
1739 }
1740 
1741 static DecodeStatus
1742 DecodeAddrMode2IdxInstruction(MCInst &Inst, unsigned Insn,
1743                               uint64_t Address, const void *Decoder) {
1744   DecodeStatus S = MCDisassembler::Success;
1745 
1746   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1747   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
1748   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
1749   unsigned imm = fieldFromInstruction(Insn, 0, 12);
1750   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1751   unsigned reg = fieldFromInstruction(Insn, 25, 1);
1752   unsigned P = fieldFromInstruction(Insn, 24, 1);
1753   unsigned W = fieldFromInstruction(Insn, 21, 1);
1754 
1755   // On stores, the writeback operand precedes Rt.
1756   switch (Inst.getOpcode()) {
1757     case ARM::STR_POST_IMM:
1758     case ARM::STR_POST_REG:
1759     case ARM::STRB_POST_IMM:
1760     case ARM::STRB_POST_REG:
1761     case ARM::STRT_POST_REG:
1762     case ARM::STRT_POST_IMM:
1763     case ARM::STRBT_POST_REG:
1764     case ARM::STRBT_POST_IMM:
1765       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1766         return MCDisassembler::Fail;
1767       break;
1768     default:
1769       break;
1770   }
1771 
1772   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
1773     return MCDisassembler::Fail;
1774 
1775   // On loads, the writeback operand comes after Rt.
1776   switch (Inst.getOpcode()) {
1777     case ARM::LDR_POST_IMM:
1778     case ARM::LDR_POST_REG:
1779     case ARM::LDRB_POST_IMM:
1780     case ARM::LDRB_POST_REG:
1781     case ARM::LDRBT_POST_REG:
1782     case ARM::LDRBT_POST_IMM:
1783     case ARM::LDRT_POST_REG:
1784     case ARM::LDRT_POST_IMM:
1785       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1786         return MCDisassembler::Fail;
1787       break;
1788     default:
1789       break;
1790   }
1791 
1792   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1793     return MCDisassembler::Fail;
1794 
1795   ARM_AM::AddrOpc Op = ARM_AM::add;
1796   if (!fieldFromInstruction(Insn, 23, 1))
1797     Op = ARM_AM::sub;
1798 
1799   bool writeback = (P == 0) || (W == 1);
1800   unsigned idx_mode = 0;
1801   if (P && writeback)
1802     idx_mode = ARMII::IndexModePre;
1803   else if (!P && writeback)
1804     idx_mode = ARMII::IndexModePost;
1805 
1806   if (writeback && (Rn == 15 || Rn == Rt))
1807     S = MCDisassembler::SoftFail; // UNPREDICTABLE
1808 
1809   if (reg) {
1810     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1811       return MCDisassembler::Fail;
1812     ARM_AM::ShiftOpc Opc = ARM_AM::lsl;
1813     switch( fieldFromInstruction(Insn, 5, 2)) {
1814       case 0:
1815         Opc = ARM_AM::lsl;
1816         break;
1817       case 1:
1818         Opc = ARM_AM::lsr;
1819         break;
1820       case 2:
1821         Opc = ARM_AM::asr;
1822         break;
1823       case 3:
1824         Opc = ARM_AM::ror;
1825         break;
1826       default:
1827         return MCDisassembler::Fail;
1828     }
1829     unsigned amt = fieldFromInstruction(Insn, 7, 5);
1830     if (Opc == ARM_AM::ror && amt == 0)
1831       Opc = ARM_AM::rrx;
1832     unsigned imm = ARM_AM::getAM2Opc(Op, amt, Opc, idx_mode);
1833 
1834     Inst.addOperand(MCOperand::createImm(imm));
1835   } else {
1836     Inst.addOperand(MCOperand::createReg(0));
1837     unsigned tmp = ARM_AM::getAM2Opc(Op, imm, ARM_AM::lsl, idx_mode);
1838     Inst.addOperand(MCOperand::createImm(tmp));
1839   }
1840 
1841   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1842     return MCDisassembler::Fail;
1843 
1844   return S;
1845 }
1846 
1847 static DecodeStatus DecodeSORegMemOperand(MCInst &Inst, unsigned Val,
1848                                   uint64_t Address, const void *Decoder) {
1849   DecodeStatus S = MCDisassembler::Success;
1850 
1851   unsigned Rn = fieldFromInstruction(Val, 13, 4);
1852   unsigned Rm = fieldFromInstruction(Val,  0, 4);
1853   unsigned type = fieldFromInstruction(Val, 5, 2);
1854   unsigned imm = fieldFromInstruction(Val, 7, 5);
1855   unsigned U = fieldFromInstruction(Val, 12, 1);
1856 
1857   ARM_AM::ShiftOpc ShOp = ARM_AM::lsl;
1858   switch (type) {
1859     case 0:
1860       ShOp = ARM_AM::lsl;
1861       break;
1862     case 1:
1863       ShOp = ARM_AM::lsr;
1864       break;
1865     case 2:
1866       ShOp = ARM_AM::asr;
1867       break;
1868     case 3:
1869       ShOp = ARM_AM::ror;
1870       break;
1871   }
1872 
1873   if (ShOp == ARM_AM::ror && imm == 0)
1874     ShOp = ARM_AM::rrx;
1875 
1876   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1877     return MCDisassembler::Fail;
1878   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1879     return MCDisassembler::Fail;
1880   unsigned shift;
1881   if (U)
1882     shift = ARM_AM::getAM2Opc(ARM_AM::add, imm, ShOp);
1883   else
1884     shift = ARM_AM::getAM2Opc(ARM_AM::sub, imm, ShOp);
1885   Inst.addOperand(MCOperand::createImm(shift));
1886 
1887   return S;
1888 }
1889 
1890 static DecodeStatus
1891 DecodeAddrMode3Instruction(MCInst &Inst, unsigned Insn,
1892                            uint64_t Address, const void *Decoder) {
1893   DecodeStatus S = MCDisassembler::Success;
1894 
1895   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
1896   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1897   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
1898   unsigned type = fieldFromInstruction(Insn, 22, 1);
1899   unsigned imm = fieldFromInstruction(Insn, 8, 4);
1900   unsigned U = ((~fieldFromInstruction(Insn, 23, 1)) & 1) << 8;
1901   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1902   unsigned W = fieldFromInstruction(Insn, 21, 1);
1903   unsigned P = fieldFromInstruction(Insn, 24, 1);
1904   unsigned Rt2 = Rt + 1;
1905 
1906   bool writeback = (W == 1) | (P == 0);
1907 
1908   // For {LD,ST}RD, Rt must be even, else undefined.
1909   switch (Inst.getOpcode()) {
1910     case ARM::STRD:
1911     case ARM::STRD_PRE:
1912     case ARM::STRD_POST:
1913     case ARM::LDRD:
1914     case ARM::LDRD_PRE:
1915     case ARM::LDRD_POST:
1916       if (Rt & 0x1) S = MCDisassembler::SoftFail;
1917       break;
1918     default:
1919       break;
1920   }
1921   switch (Inst.getOpcode()) {
1922     case ARM::STRD:
1923     case ARM::STRD_PRE:
1924     case ARM::STRD_POST:
1925       if (P == 0 && W == 1)
1926         S = MCDisassembler::SoftFail;
1927 
1928       if (writeback && (Rn == 15 || Rn == Rt || Rn == Rt2))
1929         S = MCDisassembler::SoftFail;
1930       if (type && Rm == 15)
1931         S = MCDisassembler::SoftFail;
1932       if (Rt2 == 15)
1933         S = MCDisassembler::SoftFail;
1934       if (!type && fieldFromInstruction(Insn, 8, 4))
1935         S = MCDisassembler::SoftFail;
1936       break;
1937     case ARM::STRH:
1938     case ARM::STRH_PRE:
1939     case ARM::STRH_POST:
1940       if (Rt == 15)
1941         S = MCDisassembler::SoftFail;
1942       if (writeback && (Rn == 15 || Rn == Rt))
1943         S = MCDisassembler::SoftFail;
1944       if (!type && Rm == 15)
1945         S = MCDisassembler::SoftFail;
1946       break;
1947     case ARM::LDRD:
1948     case ARM::LDRD_PRE:
1949     case ARM::LDRD_POST:
1950       if (type && Rn == 15) {
1951         if (Rt2 == 15)
1952           S = MCDisassembler::SoftFail;
1953         break;
1954       }
1955       if (P == 0 && W == 1)
1956         S = MCDisassembler::SoftFail;
1957       if (!type && (Rt2 == 15 || Rm == 15 || Rm == Rt || Rm == Rt2))
1958         S = MCDisassembler::SoftFail;
1959       if (!type && writeback && Rn == 15)
1960         S = MCDisassembler::SoftFail;
1961       if (writeback && (Rn == Rt || Rn == Rt2))
1962         S = MCDisassembler::SoftFail;
1963       break;
1964     case ARM::LDRH:
1965     case ARM::LDRH_PRE:
1966     case ARM::LDRH_POST:
1967       if (type && Rn == 15) {
1968         if (Rt == 15)
1969           S = MCDisassembler::SoftFail;
1970         break;
1971       }
1972       if (Rt == 15)
1973         S = MCDisassembler::SoftFail;
1974       if (!type && Rm == 15)
1975         S = MCDisassembler::SoftFail;
1976       if (!type && writeback && (Rn == 15 || Rn == Rt))
1977         S = MCDisassembler::SoftFail;
1978       break;
1979     case ARM::LDRSH:
1980     case ARM::LDRSH_PRE:
1981     case ARM::LDRSH_POST:
1982     case ARM::LDRSB:
1983     case ARM::LDRSB_PRE:
1984     case ARM::LDRSB_POST:
1985       if (type && Rn == 15) {
1986         if (Rt == 15)
1987           S = MCDisassembler::SoftFail;
1988         break;
1989       }
1990       if (type && (Rt == 15 || (writeback && Rn == Rt)))
1991         S = MCDisassembler::SoftFail;
1992       if (!type && (Rt == 15 || Rm == 15))
1993         S = MCDisassembler::SoftFail;
1994       if (!type && writeback && (Rn == 15 || Rn == Rt))
1995         S = MCDisassembler::SoftFail;
1996       break;
1997     default:
1998       break;
1999   }
2000 
2001   if (writeback) { // Writeback
2002     if (P)
2003       U |= ARMII::IndexModePre << 9;
2004     else
2005       U |= ARMII::IndexModePost << 9;
2006 
2007     // On stores, the writeback operand precedes Rt.
2008     switch (Inst.getOpcode()) {
2009     case ARM::STRD:
2010     case ARM::STRD_PRE:
2011     case ARM::STRD_POST:
2012     case ARM::STRH:
2013     case ARM::STRH_PRE:
2014     case ARM::STRH_POST:
2015       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2016         return MCDisassembler::Fail;
2017       break;
2018     default:
2019       break;
2020     }
2021   }
2022 
2023   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
2024     return MCDisassembler::Fail;
2025   switch (Inst.getOpcode()) {
2026     case ARM::STRD:
2027     case ARM::STRD_PRE:
2028     case ARM::STRD_POST:
2029     case ARM::LDRD:
2030     case ARM::LDRD_PRE:
2031     case ARM::LDRD_POST:
2032       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder)))
2033         return MCDisassembler::Fail;
2034       break;
2035     default:
2036       break;
2037   }
2038 
2039   if (writeback) {
2040     // On loads, the writeback operand comes after Rt.
2041     switch (Inst.getOpcode()) {
2042     case ARM::LDRD:
2043     case ARM::LDRD_PRE:
2044     case ARM::LDRD_POST:
2045     case ARM::LDRH:
2046     case ARM::LDRH_PRE:
2047     case ARM::LDRH_POST:
2048     case ARM::LDRSH:
2049     case ARM::LDRSH_PRE:
2050     case ARM::LDRSH_POST:
2051     case ARM::LDRSB:
2052     case ARM::LDRSB_PRE:
2053     case ARM::LDRSB_POST:
2054     case ARM::LDRHTr:
2055     case ARM::LDRSBTr:
2056       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2057         return MCDisassembler::Fail;
2058       break;
2059     default:
2060       break;
2061     }
2062   }
2063 
2064   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2065     return MCDisassembler::Fail;
2066 
2067   if (type) {
2068     Inst.addOperand(MCOperand::createReg(0));
2069     Inst.addOperand(MCOperand::createImm(U | (imm << 4) | Rm));
2070   } else {
2071     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2072     return MCDisassembler::Fail;
2073     Inst.addOperand(MCOperand::createImm(U));
2074   }
2075 
2076   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2077     return MCDisassembler::Fail;
2078 
2079   return S;
2080 }
2081 
2082 static DecodeStatus DecodeRFEInstruction(MCInst &Inst, unsigned Insn,
2083                                  uint64_t Address, const void *Decoder) {
2084   DecodeStatus S = MCDisassembler::Success;
2085 
2086   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2087   unsigned mode = fieldFromInstruction(Insn, 23, 2);
2088 
2089   switch (mode) {
2090     case 0:
2091       mode = ARM_AM::da;
2092       break;
2093     case 1:
2094       mode = ARM_AM::ia;
2095       break;
2096     case 2:
2097       mode = ARM_AM::db;
2098       break;
2099     case 3:
2100       mode = ARM_AM::ib;
2101       break;
2102   }
2103 
2104   Inst.addOperand(MCOperand::createImm(mode));
2105   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2106     return MCDisassembler::Fail;
2107 
2108   return S;
2109 }
2110 
2111 static DecodeStatus DecodeQADDInstruction(MCInst &Inst, unsigned Insn,
2112                                uint64_t Address, const void *Decoder) {
2113   DecodeStatus S = MCDisassembler::Success;
2114 
2115   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2116   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2117   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2118   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2119 
2120   if (pred == 0xF)
2121     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
2122 
2123   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2124     return MCDisassembler::Fail;
2125   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
2126     return MCDisassembler::Fail;
2127   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
2128     return MCDisassembler::Fail;
2129   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2130     return MCDisassembler::Fail;
2131   return S;
2132 }
2133 
2134 static DecodeStatus DecodeMemMultipleWritebackInstruction(MCInst &Inst,
2135                                   unsigned Insn,
2136                                   uint64_t Address, const void *Decoder) {
2137   DecodeStatus S = MCDisassembler::Success;
2138 
2139   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2140   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2141   unsigned reglist = fieldFromInstruction(Insn, 0, 16);
2142 
2143   if (pred == 0xF) {
2144     // Ambiguous with RFE and SRS
2145     switch (Inst.getOpcode()) {
2146       case ARM::LDMDA:
2147         Inst.setOpcode(ARM::RFEDA);
2148         break;
2149       case ARM::LDMDA_UPD:
2150         Inst.setOpcode(ARM::RFEDA_UPD);
2151         break;
2152       case ARM::LDMDB:
2153         Inst.setOpcode(ARM::RFEDB);
2154         break;
2155       case ARM::LDMDB_UPD:
2156         Inst.setOpcode(ARM::RFEDB_UPD);
2157         break;
2158       case ARM::LDMIA:
2159         Inst.setOpcode(ARM::RFEIA);
2160         break;
2161       case ARM::LDMIA_UPD:
2162         Inst.setOpcode(ARM::RFEIA_UPD);
2163         break;
2164       case ARM::LDMIB:
2165         Inst.setOpcode(ARM::RFEIB);
2166         break;
2167       case ARM::LDMIB_UPD:
2168         Inst.setOpcode(ARM::RFEIB_UPD);
2169         break;
2170       case ARM::STMDA:
2171         Inst.setOpcode(ARM::SRSDA);
2172         break;
2173       case ARM::STMDA_UPD:
2174         Inst.setOpcode(ARM::SRSDA_UPD);
2175         break;
2176       case ARM::STMDB:
2177         Inst.setOpcode(ARM::SRSDB);
2178         break;
2179       case ARM::STMDB_UPD:
2180         Inst.setOpcode(ARM::SRSDB_UPD);
2181         break;
2182       case ARM::STMIA:
2183         Inst.setOpcode(ARM::SRSIA);
2184         break;
2185       case ARM::STMIA_UPD:
2186         Inst.setOpcode(ARM::SRSIA_UPD);
2187         break;
2188       case ARM::STMIB:
2189         Inst.setOpcode(ARM::SRSIB);
2190         break;
2191       case ARM::STMIB_UPD:
2192         Inst.setOpcode(ARM::SRSIB_UPD);
2193         break;
2194       default:
2195         return MCDisassembler::Fail;
2196     }
2197 
2198     // For stores (which become SRS's, the only operand is the mode.
2199     if (fieldFromInstruction(Insn, 20, 1) == 0) {
2200       // Check SRS encoding constraints
2201       if (!(fieldFromInstruction(Insn, 22, 1) == 1 &&
2202             fieldFromInstruction(Insn, 20, 1) == 0))
2203         return MCDisassembler::Fail;
2204 
2205       Inst.addOperand(
2206           MCOperand::createImm(fieldFromInstruction(Insn, 0, 4)));
2207       return S;
2208     }
2209 
2210     return DecodeRFEInstruction(Inst, Insn, Address, Decoder);
2211   }
2212 
2213   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2214     return MCDisassembler::Fail;
2215   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2216     return MCDisassembler::Fail; // Tied
2217   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2218     return MCDisassembler::Fail;
2219   if (!Check(S, DecodeRegListOperand(Inst, reglist, Address, Decoder)))
2220     return MCDisassembler::Fail;
2221 
2222   return S;
2223 }
2224 
2225 // Check for UNPREDICTABLE predicated ESB instruction
2226 static DecodeStatus DecodeHINTInstruction(MCInst &Inst, unsigned Insn,
2227                                  uint64_t Address, const void *Decoder) {
2228   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2229   unsigned imm8 = fieldFromInstruction(Insn, 0, 8);
2230   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
2231   const FeatureBitset &FeatureBits = Dis->getSubtargetInfo().getFeatureBits();
2232 
2233   DecodeStatus S = MCDisassembler::Success;
2234 
2235   Inst.addOperand(MCOperand::createImm(imm8));
2236 
2237   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2238     return MCDisassembler::Fail;
2239 
2240   // ESB is unpredictable if pred != AL. Without the RAS extension, it is a NOP,
2241   // so all predicates should be allowed.
2242   if (imm8 == 0x10 && pred != 0xe && ((FeatureBits[ARM::FeatureRAS]) != 0))
2243     S = MCDisassembler::SoftFail;
2244 
2245   return S;
2246 }
2247 
2248 static DecodeStatus DecodeCPSInstruction(MCInst &Inst, unsigned Insn,
2249                                  uint64_t Address, const void *Decoder) {
2250   unsigned imod = fieldFromInstruction(Insn, 18, 2);
2251   unsigned M = fieldFromInstruction(Insn, 17, 1);
2252   unsigned iflags = fieldFromInstruction(Insn, 6, 3);
2253   unsigned mode = fieldFromInstruction(Insn, 0, 5);
2254 
2255   DecodeStatus S = MCDisassembler::Success;
2256 
2257   // This decoder is called from multiple location that do not check
2258   // the full encoding is valid before they do.
2259   if (fieldFromInstruction(Insn, 5, 1) != 0 ||
2260       fieldFromInstruction(Insn, 16, 1) != 0 ||
2261       fieldFromInstruction(Insn, 20, 8) != 0x10)
2262     return MCDisassembler::Fail;
2263 
2264   // imod == '01' --> UNPREDICTABLE
2265   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
2266   // return failure here.  The '01' imod value is unprintable, so there's
2267   // nothing useful we could do even if we returned UNPREDICTABLE.
2268 
2269   if (imod == 1) return MCDisassembler::Fail;
2270 
2271   if (imod && M) {
2272     Inst.setOpcode(ARM::CPS3p);
2273     Inst.addOperand(MCOperand::createImm(imod));
2274     Inst.addOperand(MCOperand::createImm(iflags));
2275     Inst.addOperand(MCOperand::createImm(mode));
2276   } else if (imod && !M) {
2277     Inst.setOpcode(ARM::CPS2p);
2278     Inst.addOperand(MCOperand::createImm(imod));
2279     Inst.addOperand(MCOperand::createImm(iflags));
2280     if (mode) S = MCDisassembler::SoftFail;
2281   } else if (!imod && M) {
2282     Inst.setOpcode(ARM::CPS1p);
2283     Inst.addOperand(MCOperand::createImm(mode));
2284     if (iflags) S = MCDisassembler::SoftFail;
2285   } else {
2286     // imod == '00' && M == '0' --> UNPREDICTABLE
2287     Inst.setOpcode(ARM::CPS1p);
2288     Inst.addOperand(MCOperand::createImm(mode));
2289     S = MCDisassembler::SoftFail;
2290   }
2291 
2292   return S;
2293 }
2294 
2295 static DecodeStatus DecodeT2CPSInstruction(MCInst &Inst, unsigned Insn,
2296                                  uint64_t Address, const void *Decoder) {
2297   unsigned imod = fieldFromInstruction(Insn, 9, 2);
2298   unsigned M = fieldFromInstruction(Insn, 8, 1);
2299   unsigned iflags = fieldFromInstruction(Insn, 5, 3);
2300   unsigned mode = fieldFromInstruction(Insn, 0, 5);
2301 
2302   DecodeStatus S = MCDisassembler::Success;
2303 
2304   // imod == '01' --> UNPREDICTABLE
2305   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
2306   // return failure here.  The '01' imod value is unprintable, so there's
2307   // nothing useful we could do even if we returned UNPREDICTABLE.
2308 
2309   if (imod == 1) return MCDisassembler::Fail;
2310 
2311   if (imod && M) {
2312     Inst.setOpcode(ARM::t2CPS3p);
2313     Inst.addOperand(MCOperand::createImm(imod));
2314     Inst.addOperand(MCOperand::createImm(iflags));
2315     Inst.addOperand(MCOperand::createImm(mode));
2316   } else if (imod && !M) {
2317     Inst.setOpcode(ARM::t2CPS2p);
2318     Inst.addOperand(MCOperand::createImm(imod));
2319     Inst.addOperand(MCOperand::createImm(iflags));
2320     if (mode) S = MCDisassembler::SoftFail;
2321   } else if (!imod && M) {
2322     Inst.setOpcode(ARM::t2CPS1p);
2323     Inst.addOperand(MCOperand::createImm(mode));
2324     if (iflags) S = MCDisassembler::SoftFail;
2325   } else {
2326     // imod == '00' && M == '0' --> this is a HINT instruction
2327     int imm = fieldFromInstruction(Insn, 0, 8);
2328     // HINT are defined only for immediate in [0..4]
2329     if(imm > 4) return MCDisassembler::Fail;
2330     Inst.setOpcode(ARM::t2HINT);
2331     Inst.addOperand(MCOperand::createImm(imm));
2332   }
2333 
2334   return S;
2335 }
2336 
2337 static DecodeStatus DecodeT2MOVTWInstruction(MCInst &Inst, unsigned Insn,
2338                                  uint64_t Address, const void *Decoder) {
2339   DecodeStatus S = MCDisassembler::Success;
2340 
2341   unsigned Rd = fieldFromInstruction(Insn, 8, 4);
2342   unsigned imm = 0;
2343 
2344   imm |= (fieldFromInstruction(Insn, 0, 8) << 0);
2345   imm |= (fieldFromInstruction(Insn, 12, 3) << 8);
2346   imm |= (fieldFromInstruction(Insn, 16, 4) << 12);
2347   imm |= (fieldFromInstruction(Insn, 26, 1) << 11);
2348 
2349   if (Inst.getOpcode() == ARM::t2MOVTi16)
2350     if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
2351       return MCDisassembler::Fail;
2352   if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
2353     return MCDisassembler::Fail;
2354 
2355   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
2356     Inst.addOperand(MCOperand::createImm(imm));
2357 
2358   return S;
2359 }
2360 
2361 static DecodeStatus DecodeArmMOVTWInstruction(MCInst &Inst, unsigned Insn,
2362                                  uint64_t Address, const void *Decoder) {
2363   DecodeStatus S = MCDisassembler::Success;
2364 
2365   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2366   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2367   unsigned imm = 0;
2368 
2369   imm |= (fieldFromInstruction(Insn, 0, 12) << 0);
2370   imm |= (fieldFromInstruction(Insn, 16, 4) << 12);
2371 
2372   if (Inst.getOpcode() == ARM::MOVTi16)
2373     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2374       return MCDisassembler::Fail;
2375 
2376   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2377     return MCDisassembler::Fail;
2378 
2379   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
2380     Inst.addOperand(MCOperand::createImm(imm));
2381 
2382   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2383     return MCDisassembler::Fail;
2384 
2385   return S;
2386 }
2387 
2388 static DecodeStatus DecodeSMLAInstruction(MCInst &Inst, unsigned Insn,
2389                                  uint64_t Address, const void *Decoder) {
2390   DecodeStatus S = MCDisassembler::Success;
2391 
2392   unsigned Rd = fieldFromInstruction(Insn, 16, 4);
2393   unsigned Rn = fieldFromInstruction(Insn, 0, 4);
2394   unsigned Rm = fieldFromInstruction(Insn, 8, 4);
2395   unsigned Ra = fieldFromInstruction(Insn, 12, 4);
2396   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2397 
2398   if (pred == 0xF)
2399     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
2400 
2401   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2402     return MCDisassembler::Fail;
2403   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
2404     return MCDisassembler::Fail;
2405   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
2406     return MCDisassembler::Fail;
2407   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Ra, Address, Decoder)))
2408     return MCDisassembler::Fail;
2409 
2410   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2411     return MCDisassembler::Fail;
2412 
2413   return S;
2414 }
2415 
2416 static DecodeStatus DecodeTSTInstruction(MCInst &Inst, unsigned Insn,
2417                                   uint64_t Address, const void *Decoder) {
2418   DecodeStatus S = MCDisassembler::Success;
2419 
2420   unsigned Pred = fieldFromInstruction(Insn, 28, 4);
2421   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2422   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2423 
2424   if (Pred == 0xF)
2425     return DecodeSETPANInstruction(Inst, Insn, Address, Decoder);
2426 
2427   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2428     return MCDisassembler::Fail;
2429   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2430     return MCDisassembler::Fail;
2431   if (!Check(S, DecodePredicateOperand(Inst, Pred, Address, Decoder)))
2432     return MCDisassembler::Fail;
2433 
2434   return S;
2435 }
2436 
2437 static DecodeStatus DecodeSETPANInstruction(MCInst &Inst, unsigned Insn,
2438                                   uint64_t Address, const void *Decoder) {
2439   DecodeStatus S = MCDisassembler::Success;
2440 
2441   unsigned Imm = fieldFromInstruction(Insn, 9, 1);
2442 
2443   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
2444   const FeatureBitset &FeatureBits = Dis->getSubtargetInfo().getFeatureBits();
2445 
2446   if (!FeatureBits[ARM::HasV8_1aOps] ||
2447       !FeatureBits[ARM::HasV8Ops])
2448     return MCDisassembler::Fail;
2449 
2450   // Decoder can be called from DecodeTST, which does not check the full
2451   // encoding is valid.
2452   if (fieldFromInstruction(Insn, 20,12) != 0xf11 ||
2453       fieldFromInstruction(Insn, 4,4) != 0)
2454     return MCDisassembler::Fail;
2455   if (fieldFromInstruction(Insn, 10,10) != 0 ||
2456       fieldFromInstruction(Insn, 0,4) != 0)
2457     S = MCDisassembler::SoftFail;
2458 
2459   Inst.setOpcode(ARM::SETPAN);
2460   Inst.addOperand(MCOperand::createImm(Imm));
2461 
2462   return S;
2463 }
2464 
2465 static DecodeStatus DecodeAddrModeImm12Operand(MCInst &Inst, unsigned Val,
2466                            uint64_t Address, const void *Decoder) {
2467   DecodeStatus S = MCDisassembler::Success;
2468 
2469   unsigned add = fieldFromInstruction(Val, 12, 1);
2470   unsigned imm = fieldFromInstruction(Val, 0, 12);
2471   unsigned Rn = fieldFromInstruction(Val, 13, 4);
2472 
2473   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2474     return MCDisassembler::Fail;
2475 
2476   if (!add) imm *= -1;
2477   if (imm == 0 && !add) imm = INT32_MIN;
2478   Inst.addOperand(MCOperand::createImm(imm));
2479   if (Rn == 15)
2480     tryAddingPcLoadReferenceComment(Address, Address + imm + 8, Decoder);
2481 
2482   return S;
2483 }
2484 
2485 static DecodeStatus DecodeAddrMode5Operand(MCInst &Inst, unsigned Val,
2486                                    uint64_t Address, const void *Decoder) {
2487   DecodeStatus S = MCDisassembler::Success;
2488 
2489   unsigned Rn = fieldFromInstruction(Val, 9, 4);
2490   // U == 1 to add imm, 0 to subtract it.
2491   unsigned U = fieldFromInstruction(Val, 8, 1);
2492   unsigned imm = fieldFromInstruction(Val, 0, 8);
2493 
2494   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2495     return MCDisassembler::Fail;
2496 
2497   if (U)
2498     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5Opc(ARM_AM::add, imm)));
2499   else
2500     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5Opc(ARM_AM::sub, imm)));
2501 
2502   return S;
2503 }
2504 
2505 static DecodeStatus DecodeAddrMode5FP16Operand(MCInst &Inst, unsigned Val,
2506                                    uint64_t Address, const void *Decoder) {
2507   DecodeStatus S = MCDisassembler::Success;
2508 
2509   unsigned Rn = fieldFromInstruction(Val, 9, 4);
2510   // U == 1 to add imm, 0 to subtract it.
2511   unsigned U = fieldFromInstruction(Val, 8, 1);
2512   unsigned imm = fieldFromInstruction(Val, 0, 8);
2513 
2514   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2515     return MCDisassembler::Fail;
2516 
2517   if (U)
2518     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5FP16Opc(ARM_AM::add, imm)));
2519   else
2520     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5FP16Opc(ARM_AM::sub, imm)));
2521 
2522   return S;
2523 }
2524 
2525 static DecodeStatus DecodeAddrMode7Operand(MCInst &Inst, unsigned Val,
2526                                    uint64_t Address, const void *Decoder) {
2527   return DecodeGPRRegisterClass(Inst, Val, Address, Decoder);
2528 }
2529 
2530 static DecodeStatus
2531 DecodeT2BInstruction(MCInst &Inst, unsigned Insn,
2532                      uint64_t Address, const void *Decoder) {
2533   DecodeStatus Status = MCDisassembler::Success;
2534 
2535   // Note the J1 and J2 values are from the encoded instruction.  So here
2536   // change them to I1 and I2 values via as documented:
2537   // I1 = NOT(J1 EOR S);
2538   // I2 = NOT(J2 EOR S);
2539   // and build the imm32 with one trailing zero as documented:
2540   // imm32 = SignExtend(S:I1:I2:imm10:imm11:'0', 32);
2541   unsigned S = fieldFromInstruction(Insn, 26, 1);
2542   unsigned J1 = fieldFromInstruction(Insn, 13, 1);
2543   unsigned J2 = fieldFromInstruction(Insn, 11, 1);
2544   unsigned I1 = !(J1 ^ S);
2545   unsigned I2 = !(J2 ^ S);
2546   unsigned imm10 = fieldFromInstruction(Insn, 16, 10);
2547   unsigned imm11 = fieldFromInstruction(Insn, 0, 11);
2548   unsigned tmp = (S << 23) | (I1 << 22) | (I2 << 21) | (imm10 << 11) | imm11;
2549   int imm32 = SignExtend32<25>(tmp << 1);
2550   if (!tryAddingSymbolicOperand(Address, Address + imm32 + 4,
2551                                 true, 4, Inst, Decoder))
2552     Inst.addOperand(MCOperand::createImm(imm32));
2553 
2554   return Status;
2555 }
2556 
2557 static DecodeStatus
2558 DecodeBranchImmInstruction(MCInst &Inst, unsigned Insn,
2559                            uint64_t Address, const void *Decoder) {
2560   DecodeStatus S = MCDisassembler::Success;
2561 
2562   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2563   unsigned imm = fieldFromInstruction(Insn, 0, 24) << 2;
2564 
2565   if (pred == 0xF) {
2566     Inst.setOpcode(ARM::BLXi);
2567     imm |= fieldFromInstruction(Insn, 24, 1) << 1;
2568     if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<26>(imm) + 8,
2569                                   true, 4, Inst, Decoder))
2570     Inst.addOperand(MCOperand::createImm(SignExtend32<26>(imm)));
2571     return S;
2572   }
2573 
2574   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<26>(imm) + 8,
2575                                 true, 4, Inst, Decoder))
2576     Inst.addOperand(MCOperand::createImm(SignExtend32<26>(imm)));
2577   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2578     return MCDisassembler::Fail;
2579 
2580   return S;
2581 }
2582 
2583 static DecodeStatus DecodeAddrMode6Operand(MCInst &Inst, unsigned Val,
2584                                    uint64_t Address, const void *Decoder) {
2585   DecodeStatus S = MCDisassembler::Success;
2586 
2587   unsigned Rm = fieldFromInstruction(Val, 0, 4);
2588   unsigned align = fieldFromInstruction(Val, 4, 2);
2589 
2590   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2591     return MCDisassembler::Fail;
2592   if (!align)
2593     Inst.addOperand(MCOperand::createImm(0));
2594   else
2595     Inst.addOperand(MCOperand::createImm(4 << align));
2596 
2597   return S;
2598 }
2599 
2600 static DecodeStatus DecodeVLDInstruction(MCInst &Inst, unsigned Insn,
2601                                    uint64_t Address, const void *Decoder) {
2602   DecodeStatus S = MCDisassembler::Success;
2603 
2604   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2605   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
2606   unsigned wb = fieldFromInstruction(Insn, 16, 4);
2607   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2608   Rn |= fieldFromInstruction(Insn, 4, 2) << 4;
2609   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2610 
2611   // First output register
2612   switch (Inst.getOpcode()) {
2613   case ARM::VLD1q16: case ARM::VLD1q32: case ARM::VLD1q64: case ARM::VLD1q8:
2614   case ARM::VLD1q16wb_fixed: case ARM::VLD1q16wb_register:
2615   case ARM::VLD1q32wb_fixed: case ARM::VLD1q32wb_register:
2616   case ARM::VLD1q64wb_fixed: case ARM::VLD1q64wb_register:
2617   case ARM::VLD1q8wb_fixed: case ARM::VLD1q8wb_register:
2618   case ARM::VLD2d16: case ARM::VLD2d32: case ARM::VLD2d8:
2619   case ARM::VLD2d16wb_fixed: case ARM::VLD2d16wb_register:
2620   case ARM::VLD2d32wb_fixed: case ARM::VLD2d32wb_register:
2621   case ARM::VLD2d8wb_fixed: case ARM::VLD2d8wb_register:
2622     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
2623       return MCDisassembler::Fail;
2624     break;
2625   case ARM::VLD2b16:
2626   case ARM::VLD2b32:
2627   case ARM::VLD2b8:
2628   case ARM::VLD2b16wb_fixed:
2629   case ARM::VLD2b16wb_register:
2630   case ARM::VLD2b32wb_fixed:
2631   case ARM::VLD2b32wb_register:
2632   case ARM::VLD2b8wb_fixed:
2633   case ARM::VLD2b8wb_register:
2634     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
2635       return MCDisassembler::Fail;
2636     break;
2637   default:
2638     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2639       return MCDisassembler::Fail;
2640   }
2641 
2642   // Second output register
2643   switch (Inst.getOpcode()) {
2644     case ARM::VLD3d8:
2645     case ARM::VLD3d16:
2646     case ARM::VLD3d32:
2647     case ARM::VLD3d8_UPD:
2648     case ARM::VLD3d16_UPD:
2649     case ARM::VLD3d32_UPD:
2650     case ARM::VLD4d8:
2651     case ARM::VLD4d16:
2652     case ARM::VLD4d32:
2653     case ARM::VLD4d8_UPD:
2654     case ARM::VLD4d16_UPD:
2655     case ARM::VLD4d32_UPD:
2656       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
2657         return MCDisassembler::Fail;
2658       break;
2659     case ARM::VLD3q8:
2660     case ARM::VLD3q16:
2661     case ARM::VLD3q32:
2662     case ARM::VLD3q8_UPD:
2663     case ARM::VLD3q16_UPD:
2664     case ARM::VLD3q32_UPD:
2665     case ARM::VLD4q8:
2666     case ARM::VLD4q16:
2667     case ARM::VLD4q32:
2668     case ARM::VLD4q8_UPD:
2669     case ARM::VLD4q16_UPD:
2670     case ARM::VLD4q32_UPD:
2671       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2672         return MCDisassembler::Fail;
2673       break;
2674     default:
2675       break;
2676   }
2677 
2678   // Third output register
2679   switch(Inst.getOpcode()) {
2680     case ARM::VLD3d8:
2681     case ARM::VLD3d16:
2682     case ARM::VLD3d32:
2683     case ARM::VLD3d8_UPD:
2684     case ARM::VLD3d16_UPD:
2685     case ARM::VLD3d32_UPD:
2686     case ARM::VLD4d8:
2687     case ARM::VLD4d16:
2688     case ARM::VLD4d32:
2689     case ARM::VLD4d8_UPD:
2690     case ARM::VLD4d16_UPD:
2691     case ARM::VLD4d32_UPD:
2692       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2693         return MCDisassembler::Fail;
2694       break;
2695     case ARM::VLD3q8:
2696     case ARM::VLD3q16:
2697     case ARM::VLD3q32:
2698     case ARM::VLD3q8_UPD:
2699     case ARM::VLD3q16_UPD:
2700     case ARM::VLD3q32_UPD:
2701     case ARM::VLD4q8:
2702     case ARM::VLD4q16:
2703     case ARM::VLD4q32:
2704     case ARM::VLD4q8_UPD:
2705     case ARM::VLD4q16_UPD:
2706     case ARM::VLD4q32_UPD:
2707       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
2708         return MCDisassembler::Fail;
2709       break;
2710     default:
2711       break;
2712   }
2713 
2714   // Fourth output register
2715   switch (Inst.getOpcode()) {
2716     case ARM::VLD4d8:
2717     case ARM::VLD4d16:
2718     case ARM::VLD4d32:
2719     case ARM::VLD4d8_UPD:
2720     case ARM::VLD4d16_UPD:
2721     case ARM::VLD4d32_UPD:
2722       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
2723         return MCDisassembler::Fail;
2724       break;
2725     case ARM::VLD4q8:
2726     case ARM::VLD4q16:
2727     case ARM::VLD4q32:
2728     case ARM::VLD4q8_UPD:
2729     case ARM::VLD4q16_UPD:
2730     case ARM::VLD4q32_UPD:
2731       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
2732         return MCDisassembler::Fail;
2733       break;
2734     default:
2735       break;
2736   }
2737 
2738   // Writeback operand
2739   switch (Inst.getOpcode()) {
2740     case ARM::VLD1d8wb_fixed:
2741     case ARM::VLD1d16wb_fixed:
2742     case ARM::VLD1d32wb_fixed:
2743     case ARM::VLD1d64wb_fixed:
2744     case ARM::VLD1d8wb_register:
2745     case ARM::VLD1d16wb_register:
2746     case ARM::VLD1d32wb_register:
2747     case ARM::VLD1d64wb_register:
2748     case ARM::VLD1q8wb_fixed:
2749     case ARM::VLD1q16wb_fixed:
2750     case ARM::VLD1q32wb_fixed:
2751     case ARM::VLD1q64wb_fixed:
2752     case ARM::VLD1q8wb_register:
2753     case ARM::VLD1q16wb_register:
2754     case ARM::VLD1q32wb_register:
2755     case ARM::VLD1q64wb_register:
2756     case ARM::VLD1d8Twb_fixed:
2757     case ARM::VLD1d8Twb_register:
2758     case ARM::VLD1d16Twb_fixed:
2759     case ARM::VLD1d16Twb_register:
2760     case ARM::VLD1d32Twb_fixed:
2761     case ARM::VLD1d32Twb_register:
2762     case ARM::VLD1d64Twb_fixed:
2763     case ARM::VLD1d64Twb_register:
2764     case ARM::VLD1d8Qwb_fixed:
2765     case ARM::VLD1d8Qwb_register:
2766     case ARM::VLD1d16Qwb_fixed:
2767     case ARM::VLD1d16Qwb_register:
2768     case ARM::VLD1d32Qwb_fixed:
2769     case ARM::VLD1d32Qwb_register:
2770     case ARM::VLD1d64Qwb_fixed:
2771     case ARM::VLD1d64Qwb_register:
2772     case ARM::VLD2d8wb_fixed:
2773     case ARM::VLD2d16wb_fixed:
2774     case ARM::VLD2d32wb_fixed:
2775     case ARM::VLD2q8wb_fixed:
2776     case ARM::VLD2q16wb_fixed:
2777     case ARM::VLD2q32wb_fixed:
2778     case ARM::VLD2d8wb_register:
2779     case ARM::VLD2d16wb_register:
2780     case ARM::VLD2d32wb_register:
2781     case ARM::VLD2q8wb_register:
2782     case ARM::VLD2q16wb_register:
2783     case ARM::VLD2q32wb_register:
2784     case ARM::VLD2b8wb_fixed:
2785     case ARM::VLD2b16wb_fixed:
2786     case ARM::VLD2b32wb_fixed:
2787     case ARM::VLD2b8wb_register:
2788     case ARM::VLD2b16wb_register:
2789     case ARM::VLD2b32wb_register:
2790       Inst.addOperand(MCOperand::createImm(0));
2791       break;
2792     case ARM::VLD3d8_UPD:
2793     case ARM::VLD3d16_UPD:
2794     case ARM::VLD3d32_UPD:
2795     case ARM::VLD3q8_UPD:
2796     case ARM::VLD3q16_UPD:
2797     case ARM::VLD3q32_UPD:
2798     case ARM::VLD4d8_UPD:
2799     case ARM::VLD4d16_UPD:
2800     case ARM::VLD4d32_UPD:
2801     case ARM::VLD4q8_UPD:
2802     case ARM::VLD4q16_UPD:
2803     case ARM::VLD4q32_UPD:
2804       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
2805         return MCDisassembler::Fail;
2806       break;
2807     default:
2808       break;
2809   }
2810 
2811   // AddrMode6 Base (register+alignment)
2812   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
2813     return MCDisassembler::Fail;
2814 
2815   // AddrMode6 Offset (register)
2816   switch (Inst.getOpcode()) {
2817   default:
2818     // The below have been updated to have explicit am6offset split
2819     // between fixed and register offset. For those instructions not
2820     // yet updated, we need to add an additional reg0 operand for the
2821     // fixed variant.
2822     //
2823     // The fixed offset encodes as Rm == 0xd, so we check for that.
2824     if (Rm == 0xd) {
2825       Inst.addOperand(MCOperand::createReg(0));
2826       break;
2827     }
2828     // Fall through to handle the register offset variant.
2829     LLVM_FALLTHROUGH;
2830   case ARM::VLD1d8wb_fixed:
2831   case ARM::VLD1d16wb_fixed:
2832   case ARM::VLD1d32wb_fixed:
2833   case ARM::VLD1d64wb_fixed:
2834   case ARM::VLD1d8Twb_fixed:
2835   case ARM::VLD1d16Twb_fixed:
2836   case ARM::VLD1d32Twb_fixed:
2837   case ARM::VLD1d64Twb_fixed:
2838   case ARM::VLD1d8Qwb_fixed:
2839   case ARM::VLD1d16Qwb_fixed:
2840   case ARM::VLD1d32Qwb_fixed:
2841   case ARM::VLD1d64Qwb_fixed:
2842   case ARM::VLD1d8wb_register:
2843   case ARM::VLD1d16wb_register:
2844   case ARM::VLD1d32wb_register:
2845   case ARM::VLD1d64wb_register:
2846   case ARM::VLD1q8wb_fixed:
2847   case ARM::VLD1q16wb_fixed:
2848   case ARM::VLD1q32wb_fixed:
2849   case ARM::VLD1q64wb_fixed:
2850   case ARM::VLD1q8wb_register:
2851   case ARM::VLD1q16wb_register:
2852   case ARM::VLD1q32wb_register:
2853   case ARM::VLD1q64wb_register:
2854     // The fixed offset post-increment encodes Rm == 0xd. The no-writeback
2855     // variant encodes Rm == 0xf. Anything else is a register offset post-
2856     // increment and we need to add the register operand to the instruction.
2857     if (Rm != 0xD && Rm != 0xF &&
2858         !Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2859       return MCDisassembler::Fail;
2860     break;
2861   case ARM::VLD2d8wb_fixed:
2862   case ARM::VLD2d16wb_fixed:
2863   case ARM::VLD2d32wb_fixed:
2864   case ARM::VLD2b8wb_fixed:
2865   case ARM::VLD2b16wb_fixed:
2866   case ARM::VLD2b32wb_fixed:
2867   case ARM::VLD2q8wb_fixed:
2868   case ARM::VLD2q16wb_fixed:
2869   case ARM::VLD2q32wb_fixed:
2870     break;
2871   }
2872 
2873   return S;
2874 }
2875 
2876 static DecodeStatus DecodeVLDST1Instruction(MCInst &Inst, unsigned Insn,
2877                                    uint64_t Address, const void *Decoder) {
2878   unsigned type = fieldFromInstruction(Insn, 8, 4);
2879   unsigned align = fieldFromInstruction(Insn, 4, 2);
2880   if (type == 6 && (align & 2)) return MCDisassembler::Fail;
2881   if (type == 7 && (align & 2)) return MCDisassembler::Fail;
2882   if (type == 10 && align == 3) return MCDisassembler::Fail;
2883 
2884   unsigned load = fieldFromInstruction(Insn, 21, 1);
2885   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2886               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2887 }
2888 
2889 static DecodeStatus DecodeVLDST2Instruction(MCInst &Inst, unsigned Insn,
2890                                    uint64_t Address, const void *Decoder) {
2891   unsigned size = fieldFromInstruction(Insn, 6, 2);
2892   if (size == 3) return MCDisassembler::Fail;
2893 
2894   unsigned type = fieldFromInstruction(Insn, 8, 4);
2895   unsigned align = fieldFromInstruction(Insn, 4, 2);
2896   if (type == 8 && align == 3) return MCDisassembler::Fail;
2897   if (type == 9 && align == 3) return MCDisassembler::Fail;
2898 
2899   unsigned load = fieldFromInstruction(Insn, 21, 1);
2900   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2901               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2902 }
2903 
2904 static DecodeStatus DecodeVLDST3Instruction(MCInst &Inst, unsigned Insn,
2905                                    uint64_t Address, const void *Decoder) {
2906   unsigned size = fieldFromInstruction(Insn, 6, 2);
2907   if (size == 3) return MCDisassembler::Fail;
2908 
2909   unsigned align = fieldFromInstruction(Insn, 4, 2);
2910   if (align & 2) return MCDisassembler::Fail;
2911 
2912   unsigned load = fieldFromInstruction(Insn, 21, 1);
2913   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2914               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2915 }
2916 
2917 static DecodeStatus DecodeVLDST4Instruction(MCInst &Inst, unsigned Insn,
2918                                    uint64_t Address, const void *Decoder) {
2919   unsigned size = fieldFromInstruction(Insn, 6, 2);
2920   if (size == 3) return MCDisassembler::Fail;
2921 
2922   unsigned load = fieldFromInstruction(Insn, 21, 1);
2923   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2924               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2925 }
2926 
2927 static DecodeStatus DecodeVSTInstruction(MCInst &Inst, unsigned Insn,
2928                                  uint64_t Address, const void *Decoder) {
2929   DecodeStatus S = MCDisassembler::Success;
2930 
2931   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2932   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
2933   unsigned wb = fieldFromInstruction(Insn, 16, 4);
2934   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2935   Rn |= fieldFromInstruction(Insn, 4, 2) << 4;
2936   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2937 
2938   // Writeback Operand
2939   switch (Inst.getOpcode()) {
2940     case ARM::VST1d8wb_fixed:
2941     case ARM::VST1d16wb_fixed:
2942     case ARM::VST1d32wb_fixed:
2943     case ARM::VST1d64wb_fixed:
2944     case ARM::VST1d8wb_register:
2945     case ARM::VST1d16wb_register:
2946     case ARM::VST1d32wb_register:
2947     case ARM::VST1d64wb_register:
2948     case ARM::VST1q8wb_fixed:
2949     case ARM::VST1q16wb_fixed:
2950     case ARM::VST1q32wb_fixed:
2951     case ARM::VST1q64wb_fixed:
2952     case ARM::VST1q8wb_register:
2953     case ARM::VST1q16wb_register:
2954     case ARM::VST1q32wb_register:
2955     case ARM::VST1q64wb_register:
2956     case ARM::VST1d8Twb_fixed:
2957     case ARM::VST1d16Twb_fixed:
2958     case ARM::VST1d32Twb_fixed:
2959     case ARM::VST1d64Twb_fixed:
2960     case ARM::VST1d8Twb_register:
2961     case ARM::VST1d16Twb_register:
2962     case ARM::VST1d32Twb_register:
2963     case ARM::VST1d64Twb_register:
2964     case ARM::VST1d8Qwb_fixed:
2965     case ARM::VST1d16Qwb_fixed:
2966     case ARM::VST1d32Qwb_fixed:
2967     case ARM::VST1d64Qwb_fixed:
2968     case ARM::VST1d8Qwb_register:
2969     case ARM::VST1d16Qwb_register:
2970     case ARM::VST1d32Qwb_register:
2971     case ARM::VST1d64Qwb_register:
2972     case ARM::VST2d8wb_fixed:
2973     case ARM::VST2d16wb_fixed:
2974     case ARM::VST2d32wb_fixed:
2975     case ARM::VST2d8wb_register:
2976     case ARM::VST2d16wb_register:
2977     case ARM::VST2d32wb_register:
2978     case ARM::VST2q8wb_fixed:
2979     case ARM::VST2q16wb_fixed:
2980     case ARM::VST2q32wb_fixed:
2981     case ARM::VST2q8wb_register:
2982     case ARM::VST2q16wb_register:
2983     case ARM::VST2q32wb_register:
2984     case ARM::VST2b8wb_fixed:
2985     case ARM::VST2b16wb_fixed:
2986     case ARM::VST2b32wb_fixed:
2987     case ARM::VST2b8wb_register:
2988     case ARM::VST2b16wb_register:
2989     case ARM::VST2b32wb_register:
2990       if (Rm == 0xF)
2991         return MCDisassembler::Fail;
2992       Inst.addOperand(MCOperand::createImm(0));
2993       break;
2994     case ARM::VST3d8_UPD:
2995     case ARM::VST3d16_UPD:
2996     case ARM::VST3d32_UPD:
2997     case ARM::VST3q8_UPD:
2998     case ARM::VST3q16_UPD:
2999     case ARM::VST3q32_UPD:
3000     case ARM::VST4d8_UPD:
3001     case ARM::VST4d16_UPD:
3002     case ARM::VST4d32_UPD:
3003     case ARM::VST4q8_UPD:
3004     case ARM::VST4q16_UPD:
3005     case ARM::VST4q32_UPD:
3006       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
3007         return MCDisassembler::Fail;
3008       break;
3009     default:
3010       break;
3011   }
3012 
3013   // AddrMode6 Base (register+alignment)
3014   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
3015     return MCDisassembler::Fail;
3016 
3017   // AddrMode6 Offset (register)
3018   switch (Inst.getOpcode()) {
3019     default:
3020       if (Rm == 0xD)
3021         Inst.addOperand(MCOperand::createReg(0));
3022       else if (Rm != 0xF) {
3023         if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3024           return MCDisassembler::Fail;
3025       }
3026       break;
3027     case ARM::VST1d8wb_fixed:
3028     case ARM::VST1d16wb_fixed:
3029     case ARM::VST1d32wb_fixed:
3030     case ARM::VST1d64wb_fixed:
3031     case ARM::VST1q8wb_fixed:
3032     case ARM::VST1q16wb_fixed:
3033     case ARM::VST1q32wb_fixed:
3034     case ARM::VST1q64wb_fixed:
3035     case ARM::VST1d8Twb_fixed:
3036     case ARM::VST1d16Twb_fixed:
3037     case ARM::VST1d32Twb_fixed:
3038     case ARM::VST1d64Twb_fixed:
3039     case ARM::VST1d8Qwb_fixed:
3040     case ARM::VST1d16Qwb_fixed:
3041     case ARM::VST1d32Qwb_fixed:
3042     case ARM::VST1d64Qwb_fixed:
3043     case ARM::VST2d8wb_fixed:
3044     case ARM::VST2d16wb_fixed:
3045     case ARM::VST2d32wb_fixed:
3046     case ARM::VST2q8wb_fixed:
3047     case ARM::VST2q16wb_fixed:
3048     case ARM::VST2q32wb_fixed:
3049     case ARM::VST2b8wb_fixed:
3050     case ARM::VST2b16wb_fixed:
3051     case ARM::VST2b32wb_fixed:
3052       break;
3053   }
3054 
3055   // First input register
3056   switch (Inst.getOpcode()) {
3057   case ARM::VST1q16:
3058   case ARM::VST1q32:
3059   case ARM::VST1q64:
3060   case ARM::VST1q8:
3061   case ARM::VST1q16wb_fixed:
3062   case ARM::VST1q16wb_register:
3063   case ARM::VST1q32wb_fixed:
3064   case ARM::VST1q32wb_register:
3065   case ARM::VST1q64wb_fixed:
3066   case ARM::VST1q64wb_register:
3067   case ARM::VST1q8wb_fixed:
3068   case ARM::VST1q8wb_register:
3069   case ARM::VST2d16:
3070   case ARM::VST2d32:
3071   case ARM::VST2d8:
3072   case ARM::VST2d16wb_fixed:
3073   case ARM::VST2d16wb_register:
3074   case ARM::VST2d32wb_fixed:
3075   case ARM::VST2d32wb_register:
3076   case ARM::VST2d8wb_fixed:
3077   case ARM::VST2d8wb_register:
3078     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3079       return MCDisassembler::Fail;
3080     break;
3081   case ARM::VST2b16:
3082   case ARM::VST2b32:
3083   case ARM::VST2b8:
3084   case ARM::VST2b16wb_fixed:
3085   case ARM::VST2b16wb_register:
3086   case ARM::VST2b32wb_fixed:
3087   case ARM::VST2b32wb_register:
3088   case ARM::VST2b8wb_fixed:
3089   case ARM::VST2b8wb_register:
3090     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
3091       return MCDisassembler::Fail;
3092     break;
3093   default:
3094     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3095       return MCDisassembler::Fail;
3096   }
3097 
3098   // Second input register
3099   switch (Inst.getOpcode()) {
3100     case ARM::VST3d8:
3101     case ARM::VST3d16:
3102     case ARM::VST3d32:
3103     case ARM::VST3d8_UPD:
3104     case ARM::VST3d16_UPD:
3105     case ARM::VST3d32_UPD:
3106     case ARM::VST4d8:
3107     case ARM::VST4d16:
3108     case ARM::VST4d32:
3109     case ARM::VST4d8_UPD:
3110     case ARM::VST4d16_UPD:
3111     case ARM::VST4d32_UPD:
3112       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
3113         return MCDisassembler::Fail;
3114       break;
3115     case ARM::VST3q8:
3116     case ARM::VST3q16:
3117     case ARM::VST3q32:
3118     case ARM::VST3q8_UPD:
3119     case ARM::VST3q16_UPD:
3120     case ARM::VST3q32_UPD:
3121     case ARM::VST4q8:
3122     case ARM::VST4q16:
3123     case ARM::VST4q32:
3124     case ARM::VST4q8_UPD:
3125     case ARM::VST4q16_UPD:
3126     case ARM::VST4q32_UPD:
3127       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
3128         return MCDisassembler::Fail;
3129       break;
3130     default:
3131       break;
3132   }
3133 
3134   // Third input register
3135   switch (Inst.getOpcode()) {
3136     case ARM::VST3d8:
3137     case ARM::VST3d16:
3138     case ARM::VST3d32:
3139     case ARM::VST3d8_UPD:
3140     case ARM::VST3d16_UPD:
3141     case ARM::VST3d32_UPD:
3142     case ARM::VST4d8:
3143     case ARM::VST4d16:
3144     case ARM::VST4d32:
3145     case ARM::VST4d8_UPD:
3146     case ARM::VST4d16_UPD:
3147     case ARM::VST4d32_UPD:
3148       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
3149         return MCDisassembler::Fail;
3150       break;
3151     case ARM::VST3q8:
3152     case ARM::VST3q16:
3153     case ARM::VST3q32:
3154     case ARM::VST3q8_UPD:
3155     case ARM::VST3q16_UPD:
3156     case ARM::VST3q32_UPD:
3157     case ARM::VST4q8:
3158     case ARM::VST4q16:
3159     case ARM::VST4q32:
3160     case ARM::VST4q8_UPD:
3161     case ARM::VST4q16_UPD:
3162     case ARM::VST4q32_UPD:
3163       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
3164         return MCDisassembler::Fail;
3165       break;
3166     default:
3167       break;
3168   }
3169 
3170   // Fourth input register
3171   switch (Inst.getOpcode()) {
3172     case ARM::VST4d8:
3173     case ARM::VST4d16:
3174     case ARM::VST4d32:
3175     case ARM::VST4d8_UPD:
3176     case ARM::VST4d16_UPD:
3177     case ARM::VST4d32_UPD:
3178       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
3179         return MCDisassembler::Fail;
3180       break;
3181     case ARM::VST4q8:
3182     case ARM::VST4q16:
3183     case ARM::VST4q32:
3184     case ARM::VST4q8_UPD:
3185     case ARM::VST4q16_UPD:
3186     case ARM::VST4q32_UPD:
3187       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
3188         return MCDisassembler::Fail;
3189       break;
3190     default:
3191       break;
3192   }
3193 
3194   return S;
3195 }
3196 
3197 static DecodeStatus DecodeVLD1DupInstruction(MCInst &Inst, unsigned Insn,
3198                                     uint64_t Address, const void *Decoder) {
3199   DecodeStatus S = MCDisassembler::Success;
3200 
3201   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3202   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3203   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3204   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3205   unsigned align = fieldFromInstruction(Insn, 4, 1);
3206   unsigned size = fieldFromInstruction(Insn, 6, 2);
3207 
3208   if (size == 0 && align == 1)
3209     return MCDisassembler::Fail;
3210   align *= (1 << size);
3211 
3212   switch (Inst.getOpcode()) {
3213   case ARM::VLD1DUPq16: case ARM::VLD1DUPq32: case ARM::VLD1DUPq8:
3214   case ARM::VLD1DUPq16wb_fixed: case ARM::VLD1DUPq16wb_register:
3215   case ARM::VLD1DUPq32wb_fixed: case ARM::VLD1DUPq32wb_register:
3216   case ARM::VLD1DUPq8wb_fixed: case ARM::VLD1DUPq8wb_register:
3217     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3218       return MCDisassembler::Fail;
3219     break;
3220   default:
3221     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3222       return MCDisassembler::Fail;
3223     break;
3224   }
3225   if (Rm != 0xF) {
3226     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3227       return MCDisassembler::Fail;
3228   }
3229 
3230   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3231     return MCDisassembler::Fail;
3232   Inst.addOperand(MCOperand::createImm(align));
3233 
3234   // The fixed offset post-increment encodes Rm == 0xd. The no-writeback
3235   // variant encodes Rm == 0xf. Anything else is a register offset post-
3236   // increment and we need to add the register operand to the instruction.
3237   if (Rm != 0xD && Rm != 0xF &&
3238       !Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3239     return MCDisassembler::Fail;
3240 
3241   return S;
3242 }
3243 
3244 static DecodeStatus DecodeVLD2DupInstruction(MCInst &Inst, unsigned Insn,
3245                                     uint64_t Address, const void *Decoder) {
3246   DecodeStatus S = MCDisassembler::Success;
3247 
3248   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3249   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3250   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3251   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3252   unsigned align = fieldFromInstruction(Insn, 4, 1);
3253   unsigned size = 1 << fieldFromInstruction(Insn, 6, 2);
3254   align *= 2*size;
3255 
3256   switch (Inst.getOpcode()) {
3257   case ARM::VLD2DUPd16: case ARM::VLD2DUPd32: case ARM::VLD2DUPd8:
3258   case ARM::VLD2DUPd16wb_fixed: case ARM::VLD2DUPd16wb_register:
3259   case ARM::VLD2DUPd32wb_fixed: case ARM::VLD2DUPd32wb_register:
3260   case ARM::VLD2DUPd8wb_fixed: case ARM::VLD2DUPd8wb_register:
3261     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3262       return MCDisassembler::Fail;
3263     break;
3264   case ARM::VLD2DUPd16x2: case ARM::VLD2DUPd32x2: case ARM::VLD2DUPd8x2:
3265   case ARM::VLD2DUPd16x2wb_fixed: case ARM::VLD2DUPd16x2wb_register:
3266   case ARM::VLD2DUPd32x2wb_fixed: case ARM::VLD2DUPd32x2wb_register:
3267   case ARM::VLD2DUPd8x2wb_fixed: case ARM::VLD2DUPd8x2wb_register:
3268     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
3269       return MCDisassembler::Fail;
3270     break;
3271   default:
3272     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3273       return MCDisassembler::Fail;
3274     break;
3275   }
3276 
3277   if (Rm != 0xF)
3278     Inst.addOperand(MCOperand::createImm(0));
3279 
3280   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3281     return MCDisassembler::Fail;
3282   Inst.addOperand(MCOperand::createImm(align));
3283 
3284   if (Rm != 0xD && Rm != 0xF) {
3285     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3286       return MCDisassembler::Fail;
3287   }
3288 
3289   return S;
3290 }
3291 
3292 static DecodeStatus DecodeVLD3DupInstruction(MCInst &Inst, unsigned Insn,
3293                                     uint64_t Address, const void *Decoder) {
3294   DecodeStatus S = MCDisassembler::Success;
3295 
3296   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3297   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3298   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3299   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3300   unsigned inc = fieldFromInstruction(Insn, 5, 1) + 1;
3301 
3302   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3303     return MCDisassembler::Fail;
3304   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
3305     return MCDisassembler::Fail;
3306   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
3307     return MCDisassembler::Fail;
3308   if (Rm != 0xF) {
3309     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3310       return MCDisassembler::Fail;
3311   }
3312 
3313   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3314     return MCDisassembler::Fail;
3315   Inst.addOperand(MCOperand::createImm(0));
3316 
3317   if (Rm == 0xD)
3318     Inst.addOperand(MCOperand::createReg(0));
3319   else if (Rm != 0xF) {
3320     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3321       return MCDisassembler::Fail;
3322   }
3323 
3324   return S;
3325 }
3326 
3327 static DecodeStatus DecodeVLD4DupInstruction(MCInst &Inst, unsigned Insn,
3328                                     uint64_t Address, const void *Decoder) {
3329   DecodeStatus S = MCDisassembler::Success;
3330 
3331   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3332   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3333   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3334   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3335   unsigned size = fieldFromInstruction(Insn, 6, 2);
3336   unsigned inc = fieldFromInstruction(Insn, 5, 1) + 1;
3337   unsigned align = fieldFromInstruction(Insn, 4, 1);
3338 
3339   if (size == 0x3) {
3340     if (align == 0)
3341       return MCDisassembler::Fail;
3342     align = 16;
3343   } else {
3344     if (size == 2) {
3345       align *= 8;
3346     } else {
3347       size = 1 << size;
3348       align *= 4*size;
3349     }
3350   }
3351 
3352   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3353     return MCDisassembler::Fail;
3354   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
3355     return MCDisassembler::Fail;
3356   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
3357     return MCDisassembler::Fail;
3358   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3*inc)%32, Address, Decoder)))
3359     return MCDisassembler::Fail;
3360   if (Rm != 0xF) {
3361     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3362       return MCDisassembler::Fail;
3363   }
3364 
3365   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3366     return MCDisassembler::Fail;
3367   Inst.addOperand(MCOperand::createImm(align));
3368 
3369   if (Rm == 0xD)
3370     Inst.addOperand(MCOperand::createReg(0));
3371   else if (Rm != 0xF) {
3372     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3373       return MCDisassembler::Fail;
3374   }
3375 
3376   return S;
3377 }
3378 
3379 static DecodeStatus
3380 DecodeNEONModImmInstruction(MCInst &Inst, unsigned Insn,
3381                             uint64_t Address, const void *Decoder) {
3382   DecodeStatus S = MCDisassembler::Success;
3383 
3384   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3385   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3386   unsigned imm = fieldFromInstruction(Insn, 0, 4);
3387   imm |= fieldFromInstruction(Insn, 16, 3) << 4;
3388   imm |= fieldFromInstruction(Insn, 24, 1) << 7;
3389   imm |= fieldFromInstruction(Insn, 8, 4) << 8;
3390   imm |= fieldFromInstruction(Insn, 5, 1) << 12;
3391   unsigned Q = fieldFromInstruction(Insn, 6, 1);
3392 
3393   if (Q) {
3394     if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3395     return MCDisassembler::Fail;
3396   } else {
3397     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3398     return MCDisassembler::Fail;
3399   }
3400 
3401   Inst.addOperand(MCOperand::createImm(imm));
3402 
3403   switch (Inst.getOpcode()) {
3404     case ARM::VORRiv4i16:
3405     case ARM::VORRiv2i32:
3406     case ARM::VBICiv4i16:
3407     case ARM::VBICiv2i32:
3408       if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3409         return MCDisassembler::Fail;
3410       break;
3411     case ARM::VORRiv8i16:
3412     case ARM::VORRiv4i32:
3413     case ARM::VBICiv8i16:
3414     case ARM::VBICiv4i32:
3415       if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3416         return MCDisassembler::Fail;
3417       break;
3418     default:
3419       break;
3420   }
3421 
3422   return S;
3423 }
3424 
3425 static DecodeStatus DecodeVSHLMaxInstruction(MCInst &Inst, unsigned Insn,
3426                                         uint64_t Address, const void *Decoder) {
3427   DecodeStatus S = MCDisassembler::Success;
3428 
3429   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3430   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3431   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3432   Rm |= fieldFromInstruction(Insn, 5, 1) << 4;
3433   unsigned size = fieldFromInstruction(Insn, 18, 2);
3434 
3435   if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3436     return MCDisassembler::Fail;
3437   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
3438     return MCDisassembler::Fail;
3439   Inst.addOperand(MCOperand::createImm(8 << size));
3440 
3441   return S;
3442 }
3443 
3444 static DecodeStatus DecodeShiftRight8Imm(MCInst &Inst, unsigned Val,
3445                                uint64_t Address, const void *Decoder) {
3446   Inst.addOperand(MCOperand::createImm(8 - Val));
3447   return MCDisassembler::Success;
3448 }
3449 
3450 static DecodeStatus DecodeShiftRight16Imm(MCInst &Inst, unsigned Val,
3451                                uint64_t Address, const void *Decoder) {
3452   Inst.addOperand(MCOperand::createImm(16 - Val));
3453   return MCDisassembler::Success;
3454 }
3455 
3456 static DecodeStatus DecodeShiftRight32Imm(MCInst &Inst, unsigned Val,
3457                                uint64_t Address, const void *Decoder) {
3458   Inst.addOperand(MCOperand::createImm(32 - Val));
3459   return MCDisassembler::Success;
3460 }
3461 
3462 static DecodeStatus DecodeShiftRight64Imm(MCInst &Inst, unsigned Val,
3463                                uint64_t Address, const void *Decoder) {
3464   Inst.addOperand(MCOperand::createImm(64 - Val));
3465   return MCDisassembler::Success;
3466 }
3467 
3468 static DecodeStatus DecodeTBLInstruction(MCInst &Inst, unsigned Insn,
3469                                uint64_t Address, const void *Decoder) {
3470   DecodeStatus S = MCDisassembler::Success;
3471 
3472   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3473   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3474   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3475   Rn |= fieldFromInstruction(Insn, 7, 1) << 4;
3476   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3477   Rm |= fieldFromInstruction(Insn, 5, 1) << 4;
3478   unsigned op = fieldFromInstruction(Insn, 6, 1);
3479 
3480   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3481     return MCDisassembler::Fail;
3482   if (op) {
3483     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3484     return MCDisassembler::Fail; // Writeback
3485   }
3486 
3487   switch (Inst.getOpcode()) {
3488   case ARM::VTBL2:
3489   case ARM::VTBX2:
3490     if (!Check(S, DecodeDPairRegisterClass(Inst, Rn, Address, Decoder)))
3491       return MCDisassembler::Fail;
3492     break;
3493   default:
3494     if (!Check(S, DecodeDPRRegisterClass(Inst, Rn, Address, Decoder)))
3495       return MCDisassembler::Fail;
3496   }
3497 
3498   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
3499     return MCDisassembler::Fail;
3500 
3501   return S;
3502 }
3503 
3504 static DecodeStatus DecodeThumbAddSpecialReg(MCInst &Inst, uint16_t Insn,
3505                                      uint64_t Address, const void *Decoder) {
3506   DecodeStatus S = MCDisassembler::Success;
3507 
3508   unsigned dst = fieldFromInstruction(Insn, 8, 3);
3509   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3510 
3511   if (!Check(S, DecodetGPRRegisterClass(Inst, dst, Address, Decoder)))
3512     return MCDisassembler::Fail;
3513 
3514   switch(Inst.getOpcode()) {
3515     default:
3516       return MCDisassembler::Fail;
3517     case ARM::tADR:
3518       break; // tADR does not explicitly represent the PC as an operand.
3519     case ARM::tADDrSPi:
3520       Inst.addOperand(MCOperand::createReg(ARM::SP));
3521       break;
3522   }
3523 
3524   Inst.addOperand(MCOperand::createImm(imm));
3525   return S;
3526 }
3527 
3528 static DecodeStatus DecodeThumbBROperand(MCInst &Inst, unsigned Val,
3529                                  uint64_t Address, const void *Decoder) {
3530   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<12>(Val<<1) + 4,
3531                                 true, 2, Inst, Decoder))
3532     Inst.addOperand(MCOperand::createImm(SignExtend32<12>(Val << 1)));
3533   return MCDisassembler::Success;
3534 }
3535 
3536 static DecodeStatus DecodeT2BROperand(MCInst &Inst, unsigned Val,
3537                                  uint64_t Address, const void *Decoder) {
3538   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<21>(Val) + 4,
3539                                 true, 4, Inst, Decoder))
3540     Inst.addOperand(MCOperand::createImm(SignExtend32<21>(Val)));
3541   return MCDisassembler::Success;
3542 }
3543 
3544 static DecodeStatus DecodeThumbCmpBROperand(MCInst &Inst, unsigned Val,
3545                                  uint64_t Address, const void *Decoder) {
3546   if (!tryAddingSymbolicOperand(Address, Address + (Val<<1) + 4,
3547                                 true, 2, Inst, Decoder))
3548     Inst.addOperand(MCOperand::createImm(Val << 1));
3549   return MCDisassembler::Success;
3550 }
3551 
3552 static DecodeStatus DecodeThumbAddrModeRR(MCInst &Inst, unsigned Val,
3553                                  uint64_t Address, const void *Decoder) {
3554   DecodeStatus S = MCDisassembler::Success;
3555 
3556   unsigned Rn = fieldFromInstruction(Val, 0, 3);
3557   unsigned Rm = fieldFromInstruction(Val, 3, 3);
3558 
3559   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
3560     return MCDisassembler::Fail;
3561   if (!Check(S, DecodetGPRRegisterClass(Inst, Rm, Address, Decoder)))
3562     return MCDisassembler::Fail;
3563 
3564   return S;
3565 }
3566 
3567 static DecodeStatus DecodeThumbAddrModeIS(MCInst &Inst, unsigned Val,
3568                                   uint64_t Address, const void *Decoder) {
3569   DecodeStatus S = MCDisassembler::Success;
3570 
3571   unsigned Rn = fieldFromInstruction(Val, 0, 3);
3572   unsigned imm = fieldFromInstruction(Val, 3, 5);
3573 
3574   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
3575     return MCDisassembler::Fail;
3576   Inst.addOperand(MCOperand::createImm(imm));
3577 
3578   return S;
3579 }
3580 
3581 static DecodeStatus DecodeThumbAddrModePC(MCInst &Inst, unsigned Val,
3582                                   uint64_t Address, const void *Decoder) {
3583   unsigned imm = Val << 2;
3584 
3585   Inst.addOperand(MCOperand::createImm(imm));
3586   tryAddingPcLoadReferenceComment(Address, (Address & ~2u) + imm + 4, Decoder);
3587 
3588   return MCDisassembler::Success;
3589 }
3590 
3591 static DecodeStatus DecodeThumbAddrModeSP(MCInst &Inst, unsigned Val,
3592                                   uint64_t Address, const void *Decoder) {
3593   Inst.addOperand(MCOperand::createReg(ARM::SP));
3594   Inst.addOperand(MCOperand::createImm(Val));
3595 
3596   return MCDisassembler::Success;
3597 }
3598 
3599 static DecodeStatus DecodeT2AddrModeSOReg(MCInst &Inst, unsigned Val,
3600                                   uint64_t Address, const void *Decoder) {
3601   DecodeStatus S = MCDisassembler::Success;
3602 
3603   unsigned Rn = fieldFromInstruction(Val, 6, 4);
3604   unsigned Rm = fieldFromInstruction(Val, 2, 4);
3605   unsigned imm = fieldFromInstruction(Val, 0, 2);
3606 
3607   // Thumb stores cannot use PC as dest register.
3608   switch (Inst.getOpcode()) {
3609   case ARM::t2STRHs:
3610   case ARM::t2STRBs:
3611   case ARM::t2STRs:
3612     if (Rn == 15)
3613       return MCDisassembler::Fail;
3614     break;
3615   default:
3616     break;
3617   }
3618 
3619   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3620     return MCDisassembler::Fail;
3621   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
3622     return MCDisassembler::Fail;
3623   Inst.addOperand(MCOperand::createImm(imm));
3624 
3625   return S;
3626 }
3627 
3628 static DecodeStatus DecodeT2LoadShift(MCInst &Inst, unsigned Insn,
3629                               uint64_t Address, const void *Decoder) {
3630   DecodeStatus S = MCDisassembler::Success;
3631 
3632   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3633   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3634 
3635   const FeatureBitset &featureBits =
3636     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3637 
3638   bool hasMP = featureBits[ARM::FeatureMP];
3639   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3640 
3641   if (Rn == 15) {
3642     switch (Inst.getOpcode()) {
3643     case ARM::t2LDRBs:
3644       Inst.setOpcode(ARM::t2LDRBpci);
3645       break;
3646     case ARM::t2LDRHs:
3647       Inst.setOpcode(ARM::t2LDRHpci);
3648       break;
3649     case ARM::t2LDRSHs:
3650       Inst.setOpcode(ARM::t2LDRSHpci);
3651       break;
3652     case ARM::t2LDRSBs:
3653       Inst.setOpcode(ARM::t2LDRSBpci);
3654       break;
3655     case ARM::t2LDRs:
3656       Inst.setOpcode(ARM::t2LDRpci);
3657       break;
3658     case ARM::t2PLDs:
3659       Inst.setOpcode(ARM::t2PLDpci);
3660       break;
3661     case ARM::t2PLIs:
3662       Inst.setOpcode(ARM::t2PLIpci);
3663       break;
3664     default:
3665       return MCDisassembler::Fail;
3666     }
3667 
3668     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3669   }
3670 
3671   if (Rt == 15) {
3672     switch (Inst.getOpcode()) {
3673     case ARM::t2LDRSHs:
3674       return MCDisassembler::Fail;
3675     case ARM::t2LDRHs:
3676       Inst.setOpcode(ARM::t2PLDWs);
3677       break;
3678     case ARM::t2LDRSBs:
3679       Inst.setOpcode(ARM::t2PLIs);
3680       break;
3681     default:
3682       break;
3683     }
3684   }
3685 
3686   switch (Inst.getOpcode()) {
3687     case ARM::t2PLDs:
3688       break;
3689     case ARM::t2PLIs:
3690       if (!hasV7Ops)
3691         return MCDisassembler::Fail;
3692       break;
3693     case ARM::t2PLDWs:
3694       if (!hasV7Ops || !hasMP)
3695         return MCDisassembler::Fail;
3696       break;
3697     default:
3698       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3699         return MCDisassembler::Fail;
3700   }
3701 
3702   unsigned addrmode = fieldFromInstruction(Insn, 4, 2);
3703   addrmode |= fieldFromInstruction(Insn, 0, 4) << 2;
3704   addrmode |= fieldFromInstruction(Insn, 16, 4) << 6;
3705   if (!Check(S, DecodeT2AddrModeSOReg(Inst, addrmode, Address, Decoder)))
3706     return MCDisassembler::Fail;
3707 
3708   return S;
3709 }
3710 
3711 static DecodeStatus DecodeT2LoadImm8(MCInst &Inst, unsigned Insn,
3712                                 uint64_t Address, const void* Decoder) {
3713   DecodeStatus S = MCDisassembler::Success;
3714 
3715   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3716   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3717   unsigned U = fieldFromInstruction(Insn, 9, 1);
3718   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3719   imm |= (U << 8);
3720   imm |= (Rn << 9);
3721   unsigned add = fieldFromInstruction(Insn, 9, 1);
3722 
3723   const FeatureBitset &featureBits =
3724     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3725 
3726   bool hasMP = featureBits[ARM::FeatureMP];
3727   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3728 
3729   if (Rn == 15) {
3730     switch (Inst.getOpcode()) {
3731     case ARM::t2LDRi8:
3732       Inst.setOpcode(ARM::t2LDRpci);
3733       break;
3734     case ARM::t2LDRBi8:
3735       Inst.setOpcode(ARM::t2LDRBpci);
3736       break;
3737     case ARM::t2LDRSBi8:
3738       Inst.setOpcode(ARM::t2LDRSBpci);
3739       break;
3740     case ARM::t2LDRHi8:
3741       Inst.setOpcode(ARM::t2LDRHpci);
3742       break;
3743     case ARM::t2LDRSHi8:
3744       Inst.setOpcode(ARM::t2LDRSHpci);
3745       break;
3746     case ARM::t2PLDi8:
3747       Inst.setOpcode(ARM::t2PLDpci);
3748       break;
3749     case ARM::t2PLIi8:
3750       Inst.setOpcode(ARM::t2PLIpci);
3751       break;
3752     default:
3753       return MCDisassembler::Fail;
3754     }
3755     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3756   }
3757 
3758   if (Rt == 15) {
3759     switch (Inst.getOpcode()) {
3760     case ARM::t2LDRSHi8:
3761       return MCDisassembler::Fail;
3762     case ARM::t2LDRHi8:
3763       if (!add)
3764         Inst.setOpcode(ARM::t2PLDWi8);
3765       break;
3766     case ARM::t2LDRSBi8:
3767       Inst.setOpcode(ARM::t2PLIi8);
3768       break;
3769     default:
3770       break;
3771     }
3772   }
3773 
3774   switch (Inst.getOpcode()) {
3775   case ARM::t2PLDi8:
3776     break;
3777   case ARM::t2PLIi8:
3778     if (!hasV7Ops)
3779       return MCDisassembler::Fail;
3780     break;
3781   case ARM::t2PLDWi8:
3782       if (!hasV7Ops || !hasMP)
3783         return MCDisassembler::Fail;
3784       break;
3785   default:
3786     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3787       return MCDisassembler::Fail;
3788   }
3789 
3790   if (!Check(S, DecodeT2AddrModeImm8(Inst, imm, Address, Decoder)))
3791     return MCDisassembler::Fail;
3792   return S;
3793 }
3794 
3795 static DecodeStatus DecodeT2LoadImm12(MCInst &Inst, unsigned Insn,
3796                                 uint64_t Address, const void* Decoder) {
3797   DecodeStatus S = MCDisassembler::Success;
3798 
3799   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3800   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3801   unsigned imm = fieldFromInstruction(Insn, 0, 12);
3802   imm |= (Rn << 13);
3803 
3804   const FeatureBitset &featureBits =
3805     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3806 
3807   bool hasMP = featureBits[ARM::FeatureMP];
3808   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3809 
3810   if (Rn == 15) {
3811     switch (Inst.getOpcode()) {
3812     case ARM::t2LDRi12:
3813       Inst.setOpcode(ARM::t2LDRpci);
3814       break;
3815     case ARM::t2LDRHi12:
3816       Inst.setOpcode(ARM::t2LDRHpci);
3817       break;
3818     case ARM::t2LDRSHi12:
3819       Inst.setOpcode(ARM::t2LDRSHpci);
3820       break;
3821     case ARM::t2LDRBi12:
3822       Inst.setOpcode(ARM::t2LDRBpci);
3823       break;
3824     case ARM::t2LDRSBi12:
3825       Inst.setOpcode(ARM::t2LDRSBpci);
3826       break;
3827     case ARM::t2PLDi12:
3828       Inst.setOpcode(ARM::t2PLDpci);
3829       break;
3830     case ARM::t2PLIi12:
3831       Inst.setOpcode(ARM::t2PLIpci);
3832       break;
3833     default:
3834       return MCDisassembler::Fail;
3835     }
3836     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3837   }
3838 
3839   if (Rt == 15) {
3840     switch (Inst.getOpcode()) {
3841     case ARM::t2LDRSHi12:
3842       return MCDisassembler::Fail;
3843     case ARM::t2LDRHi12:
3844       Inst.setOpcode(ARM::t2PLDWi12);
3845       break;
3846     case ARM::t2LDRSBi12:
3847       Inst.setOpcode(ARM::t2PLIi12);
3848       break;
3849     default:
3850       break;
3851     }
3852   }
3853 
3854   switch (Inst.getOpcode()) {
3855   case ARM::t2PLDi12:
3856     break;
3857   case ARM::t2PLIi12:
3858     if (!hasV7Ops)
3859       return MCDisassembler::Fail;
3860     break;
3861   case ARM::t2PLDWi12:
3862       if (!hasV7Ops || !hasMP)
3863         return MCDisassembler::Fail;
3864       break;
3865   default:
3866     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3867       return MCDisassembler::Fail;
3868   }
3869 
3870   if (!Check(S, DecodeT2AddrModeImm12(Inst, imm, Address, Decoder)))
3871     return MCDisassembler::Fail;
3872   return S;
3873 }
3874 
3875 static DecodeStatus DecodeT2LoadT(MCInst &Inst, unsigned Insn,
3876                                 uint64_t Address, const void* Decoder) {
3877   DecodeStatus S = MCDisassembler::Success;
3878 
3879   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3880   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3881   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3882   imm |= (Rn << 9);
3883 
3884   if (Rn == 15) {
3885     switch (Inst.getOpcode()) {
3886     case ARM::t2LDRT:
3887       Inst.setOpcode(ARM::t2LDRpci);
3888       break;
3889     case ARM::t2LDRBT:
3890       Inst.setOpcode(ARM::t2LDRBpci);
3891       break;
3892     case ARM::t2LDRHT:
3893       Inst.setOpcode(ARM::t2LDRHpci);
3894       break;
3895     case ARM::t2LDRSBT:
3896       Inst.setOpcode(ARM::t2LDRSBpci);
3897       break;
3898     case ARM::t2LDRSHT:
3899       Inst.setOpcode(ARM::t2LDRSHpci);
3900       break;
3901     default:
3902       return MCDisassembler::Fail;
3903     }
3904     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3905   }
3906 
3907   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
3908     return MCDisassembler::Fail;
3909   if (!Check(S, DecodeT2AddrModeImm8(Inst, imm, Address, Decoder)))
3910     return MCDisassembler::Fail;
3911   return S;
3912 }
3913 
3914 static DecodeStatus DecodeT2LoadLabel(MCInst &Inst, unsigned Insn,
3915                                 uint64_t Address, const void* Decoder) {
3916   DecodeStatus S = MCDisassembler::Success;
3917 
3918   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3919   unsigned U = fieldFromInstruction(Insn, 23, 1);
3920   int imm = fieldFromInstruction(Insn, 0, 12);
3921 
3922   const FeatureBitset &featureBits =
3923     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3924 
3925   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3926 
3927   if (Rt == 15) {
3928     switch (Inst.getOpcode()) {
3929       case ARM::t2LDRBpci:
3930       case ARM::t2LDRHpci:
3931         Inst.setOpcode(ARM::t2PLDpci);
3932         break;
3933       case ARM::t2LDRSBpci:
3934         Inst.setOpcode(ARM::t2PLIpci);
3935         break;
3936       case ARM::t2LDRSHpci:
3937         return MCDisassembler::Fail;
3938       default:
3939         break;
3940     }
3941   }
3942 
3943   switch(Inst.getOpcode()) {
3944   case ARM::t2PLDpci:
3945     break;
3946   case ARM::t2PLIpci:
3947     if (!hasV7Ops)
3948       return MCDisassembler::Fail;
3949     break;
3950   default:
3951     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3952       return MCDisassembler::Fail;
3953   }
3954 
3955   if (!U) {
3956     // Special case for #-0.
3957     if (imm == 0)
3958       imm = INT32_MIN;
3959     else
3960       imm = -imm;
3961   }
3962   Inst.addOperand(MCOperand::createImm(imm));
3963 
3964   return S;
3965 }
3966 
3967 static DecodeStatus DecodeT2Imm8S4(MCInst &Inst, unsigned Val,
3968                            uint64_t Address, const void *Decoder) {
3969   if (Val == 0)
3970     Inst.addOperand(MCOperand::createImm(INT32_MIN));
3971   else {
3972     int imm = Val & 0xFF;
3973 
3974     if (!(Val & 0x100)) imm *= -1;
3975     Inst.addOperand(MCOperand::createImm(imm * 4));
3976   }
3977 
3978   return MCDisassembler::Success;
3979 }
3980 
3981 static DecodeStatus DecodeT2Imm7S4(MCInst &Inst, unsigned Val, uint64_t Address,
3982                                    const void *Decoder) {
3983   if (Val == 0)
3984     Inst.addOperand(MCOperand::createImm(INT32_MIN));
3985   else {
3986     int imm = Val & 0x7F;
3987 
3988     if (!(Val & 0x80))
3989       imm *= -1;
3990     Inst.addOperand(MCOperand::createImm(imm * 4));
3991   }
3992 
3993   return MCDisassembler::Success;
3994 }
3995 
3996 static DecodeStatus DecodeT2AddrModeImm8s4(MCInst &Inst, unsigned Val,
3997                                    uint64_t Address, const void *Decoder) {
3998   DecodeStatus S = MCDisassembler::Success;
3999 
4000   unsigned Rn = fieldFromInstruction(Val, 9, 4);
4001   unsigned imm = fieldFromInstruction(Val, 0, 9);
4002 
4003   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4004     return MCDisassembler::Fail;
4005   if (!Check(S, DecodeT2Imm8S4(Inst, imm, Address, Decoder)))
4006     return MCDisassembler::Fail;
4007 
4008   return S;
4009 }
4010 
4011 static DecodeStatus DecodeT2AddrModeImm7s4(MCInst &Inst, unsigned Val,
4012                                            uint64_t Address,
4013                                            const void *Decoder) {
4014   DecodeStatus S = MCDisassembler::Success;
4015 
4016   unsigned Rn = fieldFromInstruction(Val, 8, 4);
4017   unsigned imm = fieldFromInstruction(Val, 0, 8);
4018 
4019   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4020     return MCDisassembler::Fail;
4021   if (!Check(S, DecodeT2Imm7S4(Inst, imm, Address, Decoder)))
4022     return MCDisassembler::Fail;
4023 
4024   return S;
4025 }
4026 
4027 static DecodeStatus DecodeT2AddrModeImm0_1020s4(MCInst &Inst,unsigned Val,
4028                                    uint64_t Address, const void *Decoder) {
4029   DecodeStatus S = MCDisassembler::Success;
4030 
4031   unsigned Rn = fieldFromInstruction(Val, 8, 4);
4032   unsigned imm = fieldFromInstruction(Val, 0, 8);
4033 
4034   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4035     return MCDisassembler::Fail;
4036 
4037   Inst.addOperand(MCOperand::createImm(imm));
4038 
4039   return S;
4040 }
4041 
4042 static DecodeStatus DecodeT2Imm8(MCInst &Inst, unsigned Val,
4043                          uint64_t Address, const void *Decoder) {
4044   int imm = Val & 0xFF;
4045   if (Val == 0)
4046     imm = INT32_MIN;
4047   else if (!(Val & 0x100))
4048     imm *= -1;
4049   Inst.addOperand(MCOperand::createImm(imm));
4050 
4051   return MCDisassembler::Success;
4052 }
4053 
4054 static DecodeStatus DecodeT2AddrModeImm8(MCInst &Inst, unsigned Val,
4055                                  uint64_t Address, const void *Decoder) {
4056   DecodeStatus S = MCDisassembler::Success;
4057 
4058   unsigned Rn = fieldFromInstruction(Val, 9, 4);
4059   unsigned imm = fieldFromInstruction(Val, 0, 9);
4060 
4061   // Thumb stores cannot use PC as dest register.
4062   switch (Inst.getOpcode()) {
4063   case ARM::t2STRT:
4064   case ARM::t2STRBT:
4065   case ARM::t2STRHT:
4066   case ARM::t2STRi8:
4067   case ARM::t2STRHi8:
4068   case ARM::t2STRBi8:
4069     if (Rn == 15)
4070       return MCDisassembler::Fail;
4071     break;
4072   default:
4073     break;
4074   }
4075 
4076   // Some instructions always use an additive offset.
4077   switch (Inst.getOpcode()) {
4078     case ARM::t2LDRT:
4079     case ARM::t2LDRBT:
4080     case ARM::t2LDRHT:
4081     case ARM::t2LDRSBT:
4082     case ARM::t2LDRSHT:
4083     case ARM::t2STRT:
4084     case ARM::t2STRBT:
4085     case ARM::t2STRHT:
4086       imm |= 0x100;
4087       break;
4088     default:
4089       break;
4090   }
4091 
4092   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4093     return MCDisassembler::Fail;
4094   if (!Check(S, DecodeT2Imm8(Inst, imm, Address, Decoder)))
4095     return MCDisassembler::Fail;
4096 
4097   return S;
4098 }
4099 
4100 static DecodeStatus DecodeT2LdStPre(MCInst &Inst, unsigned Insn,
4101                                     uint64_t Address, const void *Decoder) {
4102   DecodeStatus S = MCDisassembler::Success;
4103 
4104   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4105   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4106   unsigned addr = fieldFromInstruction(Insn, 0, 8);
4107   addr |= fieldFromInstruction(Insn, 9, 1) << 8;
4108   addr |= Rn << 9;
4109   unsigned load = fieldFromInstruction(Insn, 20, 1);
4110 
4111   if (Rn == 15) {
4112     switch (Inst.getOpcode()) {
4113     case ARM::t2LDR_PRE:
4114     case ARM::t2LDR_POST:
4115       Inst.setOpcode(ARM::t2LDRpci);
4116       break;
4117     case ARM::t2LDRB_PRE:
4118     case ARM::t2LDRB_POST:
4119       Inst.setOpcode(ARM::t2LDRBpci);
4120       break;
4121     case ARM::t2LDRH_PRE:
4122     case ARM::t2LDRH_POST:
4123       Inst.setOpcode(ARM::t2LDRHpci);
4124       break;
4125     case ARM::t2LDRSB_PRE:
4126     case ARM::t2LDRSB_POST:
4127       if (Rt == 15)
4128         Inst.setOpcode(ARM::t2PLIpci);
4129       else
4130         Inst.setOpcode(ARM::t2LDRSBpci);
4131       break;
4132     case ARM::t2LDRSH_PRE:
4133     case ARM::t2LDRSH_POST:
4134       Inst.setOpcode(ARM::t2LDRSHpci);
4135       break;
4136     default:
4137       return MCDisassembler::Fail;
4138     }
4139     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
4140   }
4141 
4142   if (!load) {
4143     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4144       return MCDisassembler::Fail;
4145   }
4146 
4147   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4148     return MCDisassembler::Fail;
4149 
4150   if (load) {
4151     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4152       return MCDisassembler::Fail;
4153   }
4154 
4155   if (!Check(S, DecodeT2AddrModeImm8(Inst, addr, Address, Decoder)))
4156     return MCDisassembler::Fail;
4157 
4158   return S;
4159 }
4160 
4161 static DecodeStatus DecodeT2AddrModeImm12(MCInst &Inst, unsigned Val,
4162                                   uint64_t Address, const void *Decoder) {
4163   DecodeStatus S = MCDisassembler::Success;
4164 
4165   unsigned Rn = fieldFromInstruction(Val, 13, 4);
4166   unsigned imm = fieldFromInstruction(Val, 0, 12);
4167 
4168   // Thumb stores cannot use PC as dest register.
4169   switch (Inst.getOpcode()) {
4170   case ARM::t2STRi12:
4171   case ARM::t2STRBi12:
4172   case ARM::t2STRHi12:
4173     if (Rn == 15)
4174       return MCDisassembler::Fail;
4175     break;
4176   default:
4177     break;
4178   }
4179 
4180   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4181     return MCDisassembler::Fail;
4182   Inst.addOperand(MCOperand::createImm(imm));
4183 
4184   return S;
4185 }
4186 
4187 static DecodeStatus DecodeThumbAddSPImm(MCInst &Inst, uint16_t Insn,
4188                                 uint64_t Address, const void *Decoder) {
4189   unsigned imm = fieldFromInstruction(Insn, 0, 7);
4190 
4191   Inst.addOperand(MCOperand::createReg(ARM::SP));
4192   Inst.addOperand(MCOperand::createReg(ARM::SP));
4193   Inst.addOperand(MCOperand::createImm(imm));
4194 
4195   return MCDisassembler::Success;
4196 }
4197 
4198 static DecodeStatus DecodeThumbAddSPReg(MCInst &Inst, uint16_t Insn,
4199                                 uint64_t Address, const void *Decoder) {
4200   DecodeStatus S = MCDisassembler::Success;
4201 
4202   if (Inst.getOpcode() == ARM::tADDrSP) {
4203     unsigned Rdm = fieldFromInstruction(Insn, 0, 3);
4204     Rdm |= fieldFromInstruction(Insn, 7, 1) << 3;
4205 
4206     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
4207     return MCDisassembler::Fail;
4208     Inst.addOperand(MCOperand::createReg(ARM::SP));
4209     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
4210     return MCDisassembler::Fail;
4211   } else if (Inst.getOpcode() == ARM::tADDspr) {
4212     unsigned Rm = fieldFromInstruction(Insn, 3, 4);
4213 
4214     Inst.addOperand(MCOperand::createReg(ARM::SP));
4215     Inst.addOperand(MCOperand::createReg(ARM::SP));
4216     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4217     return MCDisassembler::Fail;
4218   }
4219 
4220   return S;
4221 }
4222 
4223 static DecodeStatus DecodeThumbCPS(MCInst &Inst, uint16_t Insn,
4224                            uint64_t Address, const void *Decoder) {
4225   unsigned imod = fieldFromInstruction(Insn, 4, 1) | 0x2;
4226   unsigned flags = fieldFromInstruction(Insn, 0, 3);
4227 
4228   Inst.addOperand(MCOperand::createImm(imod));
4229   Inst.addOperand(MCOperand::createImm(flags));
4230 
4231   return MCDisassembler::Success;
4232 }
4233 
4234 static DecodeStatus DecodePostIdxReg(MCInst &Inst, unsigned Insn,
4235                              uint64_t Address, const void *Decoder) {
4236   DecodeStatus S = MCDisassembler::Success;
4237   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4238   unsigned add = fieldFromInstruction(Insn, 4, 1);
4239 
4240   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
4241     return MCDisassembler::Fail;
4242   Inst.addOperand(MCOperand::createImm(add));
4243 
4244   return S;
4245 }
4246 
4247 static DecodeStatus DecodeThumbBLXOffset(MCInst &Inst, unsigned Val,
4248                                  uint64_t Address, const void *Decoder) {
4249   // Val is passed in as S:J1:J2:imm10H:imm10L:'0'
4250   // Note only one trailing zero not two.  Also the J1 and J2 values are from
4251   // the encoded instruction.  So here change to I1 and I2 values via:
4252   // I1 = NOT(J1 EOR S);
4253   // I2 = NOT(J2 EOR S);
4254   // and build the imm32 with two trailing zeros as documented:
4255   // imm32 = SignExtend(S:I1:I2:imm10H:imm10L:'00', 32);
4256   unsigned S = (Val >> 23) & 1;
4257   unsigned J1 = (Val >> 22) & 1;
4258   unsigned J2 = (Val >> 21) & 1;
4259   unsigned I1 = !(J1 ^ S);
4260   unsigned I2 = !(J2 ^ S);
4261   unsigned tmp = (Val & ~0x600000) | (I1 << 22) | (I2 << 21);
4262   int imm32 = SignExtend32<25>(tmp << 1);
4263 
4264   if (!tryAddingSymbolicOperand(Address,
4265                                 (Address & ~2u) + imm32 + 4,
4266                                 true, 4, Inst, Decoder))
4267     Inst.addOperand(MCOperand::createImm(imm32));
4268   return MCDisassembler::Success;
4269 }
4270 
4271 static DecodeStatus DecodeCoprocessor(MCInst &Inst, unsigned Val,
4272                               uint64_t Address, const void *Decoder) {
4273   if (Val == 0xA || Val == 0xB)
4274     return MCDisassembler::Fail;
4275 
4276   const FeatureBitset &featureBits =
4277     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4278 
4279   if (featureBits[ARM::HasV8Ops] && !(Val == 14 || Val == 15))
4280     return MCDisassembler::Fail;
4281 
4282   // For Armv8.1-M Mainline coprocessors matching 100x,101x or 111x should
4283   // decode as VFP/MVE instructions.
4284   if (featureBits[ARM::HasV8_1MMainlineOps] &&
4285       ((Val & 0xE) == 0x8 || (Val & 0xE) == 0xA ||
4286        (Val & 0xE) == 0xE))
4287     return MCDisassembler::Fail;
4288 
4289   Inst.addOperand(MCOperand::createImm(Val));
4290   return MCDisassembler::Success;
4291 }
4292 
4293 static DecodeStatus
4294 DecodeThumbTableBranch(MCInst &Inst, unsigned Insn,
4295                        uint64_t Address, const void *Decoder) {
4296   DecodeStatus S = MCDisassembler::Success;
4297 
4298   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4299   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4300 
4301   if (Rn == ARM::SP) S = MCDisassembler::SoftFail;
4302   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4303     return MCDisassembler::Fail;
4304   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
4305     return MCDisassembler::Fail;
4306   return S;
4307 }
4308 
4309 static DecodeStatus
4310 DecodeThumb2BCCInstruction(MCInst &Inst, unsigned Insn,
4311                            uint64_t Address, const void *Decoder) {
4312   DecodeStatus S = MCDisassembler::Success;
4313 
4314   unsigned pred = fieldFromInstruction(Insn, 22, 4);
4315   if (pred == 0xE || pred == 0xF) {
4316     unsigned opc = fieldFromInstruction(Insn, 4, 28);
4317     switch (opc) {
4318       default:
4319         return MCDisassembler::Fail;
4320       case 0xf3bf8f4:
4321         Inst.setOpcode(ARM::t2DSB);
4322         break;
4323       case 0xf3bf8f5:
4324         Inst.setOpcode(ARM::t2DMB);
4325         break;
4326       case 0xf3bf8f6:
4327         Inst.setOpcode(ARM::t2ISB);
4328         break;
4329     }
4330 
4331     unsigned imm = fieldFromInstruction(Insn, 0, 4);
4332     return DecodeMemBarrierOption(Inst, imm, Address, Decoder);
4333   }
4334 
4335   unsigned brtarget = fieldFromInstruction(Insn, 0, 11) << 1;
4336   brtarget |= fieldFromInstruction(Insn, 11, 1) << 19;
4337   brtarget |= fieldFromInstruction(Insn, 13, 1) << 18;
4338   brtarget |= fieldFromInstruction(Insn, 16, 6) << 12;
4339   brtarget |= fieldFromInstruction(Insn, 26, 1) << 20;
4340 
4341   if (!Check(S, DecodeT2BROperand(Inst, brtarget, Address, Decoder)))
4342     return MCDisassembler::Fail;
4343   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4344     return MCDisassembler::Fail;
4345 
4346   return S;
4347 }
4348 
4349 // Decode a shifted immediate operand.  These basically consist
4350 // of an 8-bit value, and a 4-bit directive that specifies either
4351 // a splat operation or a rotation.
4352 static DecodeStatus DecodeT2SOImm(MCInst &Inst, unsigned Val,
4353                           uint64_t Address, const void *Decoder) {
4354   unsigned ctrl = fieldFromInstruction(Val, 10, 2);
4355   if (ctrl == 0) {
4356     unsigned byte = fieldFromInstruction(Val, 8, 2);
4357     unsigned imm = fieldFromInstruction(Val, 0, 8);
4358     switch (byte) {
4359       case 0:
4360         Inst.addOperand(MCOperand::createImm(imm));
4361         break;
4362       case 1:
4363         Inst.addOperand(MCOperand::createImm((imm << 16) | imm));
4364         break;
4365       case 2:
4366         Inst.addOperand(MCOperand::createImm((imm << 24) | (imm << 8)));
4367         break;
4368       case 3:
4369         Inst.addOperand(MCOperand::createImm((imm << 24) | (imm << 16) |
4370                                              (imm << 8)  |  imm));
4371         break;
4372     }
4373   } else {
4374     unsigned unrot = fieldFromInstruction(Val, 0, 7) | 0x80;
4375     unsigned rot = fieldFromInstruction(Val, 7, 5);
4376     unsigned imm = (unrot >> rot) | (unrot << ((32-rot)&31));
4377     Inst.addOperand(MCOperand::createImm(imm));
4378   }
4379 
4380   return MCDisassembler::Success;
4381 }
4382 
4383 static DecodeStatus
4384 DecodeThumbBCCTargetOperand(MCInst &Inst, unsigned Val,
4385                             uint64_t Address, const void *Decoder) {
4386   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<9>(Val<<1) + 4,
4387                                 true, 2, Inst, Decoder))
4388     Inst.addOperand(MCOperand::createImm(SignExtend32<9>(Val << 1)));
4389   return MCDisassembler::Success;
4390 }
4391 
4392 static DecodeStatus DecodeThumbBLTargetOperand(MCInst &Inst, unsigned Val,
4393                                                uint64_t Address,
4394                                                const void *Decoder) {
4395   // Val is passed in as S:J1:J2:imm10:imm11
4396   // Note no trailing zero after imm11.  Also the J1 and J2 values are from
4397   // the encoded instruction.  So here change to I1 and I2 values via:
4398   // I1 = NOT(J1 EOR S);
4399   // I2 = NOT(J2 EOR S);
4400   // and build the imm32 with one trailing zero as documented:
4401   // imm32 = SignExtend(S:I1:I2:imm10:imm11:'0', 32);
4402   unsigned S = (Val >> 23) & 1;
4403   unsigned J1 = (Val >> 22) & 1;
4404   unsigned J2 = (Val >> 21) & 1;
4405   unsigned I1 = !(J1 ^ S);
4406   unsigned I2 = !(J2 ^ S);
4407   unsigned tmp = (Val & ~0x600000) | (I1 << 22) | (I2 << 21);
4408   int imm32 = SignExtend32<25>(tmp << 1);
4409 
4410   if (!tryAddingSymbolicOperand(Address, Address + imm32 + 4,
4411                                 true, 4, Inst, Decoder))
4412     Inst.addOperand(MCOperand::createImm(imm32));
4413   return MCDisassembler::Success;
4414 }
4415 
4416 static DecodeStatus DecodeMemBarrierOption(MCInst &Inst, unsigned Val,
4417                                    uint64_t Address, const void *Decoder) {
4418   if (Val & ~0xf)
4419     return MCDisassembler::Fail;
4420 
4421   Inst.addOperand(MCOperand::createImm(Val));
4422   return MCDisassembler::Success;
4423 }
4424 
4425 static DecodeStatus DecodeInstSyncBarrierOption(MCInst &Inst, unsigned Val,
4426                                         uint64_t Address, const void *Decoder) {
4427   if (Val & ~0xf)
4428     return MCDisassembler::Fail;
4429 
4430   Inst.addOperand(MCOperand::createImm(Val));
4431   return MCDisassembler::Success;
4432 }
4433 
4434 static DecodeStatus DecodeMSRMask(MCInst &Inst, unsigned Val,
4435                           uint64_t Address, const void *Decoder) {
4436   DecodeStatus S = MCDisassembler::Success;
4437   const FeatureBitset &FeatureBits =
4438     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4439 
4440   if (FeatureBits[ARM::FeatureMClass]) {
4441     unsigned ValLow = Val & 0xff;
4442 
4443     // Validate the SYSm value first.
4444     switch (ValLow) {
4445     case  0: // apsr
4446     case  1: // iapsr
4447     case  2: // eapsr
4448     case  3: // xpsr
4449     case  5: // ipsr
4450     case  6: // epsr
4451     case  7: // iepsr
4452     case  8: // msp
4453     case  9: // psp
4454     case 16: // primask
4455     case 20: // control
4456       break;
4457     case 17: // basepri
4458     case 18: // basepri_max
4459     case 19: // faultmask
4460       if (!(FeatureBits[ARM::HasV7Ops]))
4461         // Values basepri, basepri_max and faultmask are only valid for v7m.
4462         return MCDisassembler::Fail;
4463       break;
4464     case 0x8a: // msplim_ns
4465     case 0x8b: // psplim_ns
4466     case 0x91: // basepri_ns
4467     case 0x93: // faultmask_ns
4468       if (!(FeatureBits[ARM::HasV8MMainlineOps]))
4469         return MCDisassembler::Fail;
4470       LLVM_FALLTHROUGH;
4471     case 10:   // msplim
4472     case 11:   // psplim
4473     case 0x88: // msp_ns
4474     case 0x89: // psp_ns
4475     case 0x90: // primask_ns
4476     case 0x94: // control_ns
4477     case 0x98: // sp_ns
4478       if (!(FeatureBits[ARM::Feature8MSecExt]))
4479         return MCDisassembler::Fail;
4480       break;
4481     default:
4482       // Architecturally defined as unpredictable
4483       S = MCDisassembler::SoftFail;
4484       break;
4485     }
4486 
4487     if (Inst.getOpcode() == ARM::t2MSR_M) {
4488       unsigned Mask = fieldFromInstruction(Val, 10, 2);
4489       if (!(FeatureBits[ARM::HasV7Ops])) {
4490         // The ARMv6-M MSR bits {11-10} can be only 0b10, other values are
4491         // unpredictable.
4492         if (Mask != 2)
4493           S = MCDisassembler::SoftFail;
4494       }
4495       else {
4496         // The ARMv7-M architecture stores an additional 2-bit mask value in
4497         // MSR bits {11-10}. The mask is used only with apsr, iapsr, eapsr and
4498         // xpsr, it has to be 0b10 in other cases. Bit mask{1} indicates if
4499         // the NZCVQ bits should be moved by the instruction. Bit mask{0}
4500         // indicates the move for the GE{3:0} bits, the mask{0} bit can be set
4501         // only if the processor includes the DSP extension.
4502         if (Mask == 0 || (Mask != 2 && ValLow > 3) ||
4503             (!(FeatureBits[ARM::FeatureDSP]) && (Mask & 1)))
4504           S = MCDisassembler::SoftFail;
4505       }
4506     }
4507   } else {
4508     // A/R class
4509     if (Val == 0)
4510       return MCDisassembler::Fail;
4511   }
4512   Inst.addOperand(MCOperand::createImm(Val));
4513   return S;
4514 }
4515 
4516 static DecodeStatus DecodeBankedReg(MCInst &Inst, unsigned Val,
4517                                     uint64_t Address, const void *Decoder) {
4518   unsigned R = fieldFromInstruction(Val, 5, 1);
4519   unsigned SysM = fieldFromInstruction(Val, 0, 5);
4520 
4521   // The table of encodings for these banked registers comes from B9.2.3 of the
4522   // ARM ARM. There are patterns, but nothing regular enough to make this logic
4523   // neater. So by fiat, these values are UNPREDICTABLE:
4524   if (!ARMBankedReg::lookupBankedRegByEncoding((R << 5) | SysM))
4525     return MCDisassembler::Fail;
4526 
4527   Inst.addOperand(MCOperand::createImm(Val));
4528   return MCDisassembler::Success;
4529 }
4530 
4531 static DecodeStatus DecodeDoubleRegLoad(MCInst &Inst, unsigned Insn,
4532                                         uint64_t Address, const void *Decoder) {
4533   DecodeStatus S = MCDisassembler::Success;
4534 
4535   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4536   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4537   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4538 
4539   if (Rn == 0xF)
4540     S = MCDisassembler::SoftFail;
4541 
4542   if (!Check(S, DecodeGPRPairRegisterClass(Inst, Rt, Address, Decoder)))
4543     return MCDisassembler::Fail;
4544   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4545     return MCDisassembler::Fail;
4546   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4547     return MCDisassembler::Fail;
4548 
4549   return S;
4550 }
4551 
4552 static DecodeStatus DecodeDoubleRegStore(MCInst &Inst, unsigned Insn,
4553                                          uint64_t Address,
4554                                          const void *Decoder) {
4555   DecodeStatus S = MCDisassembler::Success;
4556 
4557   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4558   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
4559   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4560   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4561 
4562   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
4563     return MCDisassembler::Fail;
4564 
4565   if (Rn == 0xF || Rd == Rn || Rd == Rt || Rd == Rt+1)
4566     S = MCDisassembler::SoftFail;
4567 
4568   if (!Check(S, DecodeGPRPairRegisterClass(Inst, Rt, Address, Decoder)))
4569     return MCDisassembler::Fail;
4570   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4571     return MCDisassembler::Fail;
4572   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4573     return MCDisassembler::Fail;
4574 
4575   return S;
4576 }
4577 
4578 static DecodeStatus DecodeLDRPreImm(MCInst &Inst, unsigned Insn,
4579                             uint64_t Address, const void *Decoder) {
4580   DecodeStatus S = MCDisassembler::Success;
4581 
4582   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4583   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4584   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4585   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4586   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4587   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4588 
4589   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4590 
4591   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4592     return MCDisassembler::Fail;
4593   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4594     return MCDisassembler::Fail;
4595   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
4596     return MCDisassembler::Fail;
4597   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4598     return MCDisassembler::Fail;
4599 
4600   return S;
4601 }
4602 
4603 static DecodeStatus DecodeLDRPreReg(MCInst &Inst, unsigned Insn,
4604                             uint64_t Address, const void *Decoder) {
4605   DecodeStatus S = MCDisassembler::Success;
4606 
4607   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4608   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4609   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4610   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4611   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4612   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4613   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4614 
4615   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4616   if (Rm == 0xF) S = MCDisassembler::SoftFail;
4617 
4618   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4619     return MCDisassembler::Fail;
4620   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4621     return MCDisassembler::Fail;
4622   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
4623     return MCDisassembler::Fail;
4624   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4625     return MCDisassembler::Fail;
4626 
4627   return S;
4628 }
4629 
4630 static DecodeStatus DecodeSTRPreImm(MCInst &Inst, unsigned Insn,
4631                             uint64_t Address, const void *Decoder) {
4632   DecodeStatus S = MCDisassembler::Success;
4633 
4634   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4635   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4636   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4637   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4638   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4639   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4640 
4641   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4642 
4643   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4644     return MCDisassembler::Fail;
4645   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4646     return MCDisassembler::Fail;
4647   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
4648     return MCDisassembler::Fail;
4649   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4650     return MCDisassembler::Fail;
4651 
4652   return S;
4653 }
4654 
4655 static DecodeStatus DecodeSTRPreReg(MCInst &Inst, unsigned Insn,
4656                             uint64_t Address, const void *Decoder) {
4657   DecodeStatus S = MCDisassembler::Success;
4658 
4659   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4660   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4661   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4662   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4663   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4664   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4665 
4666   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4667 
4668   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4669     return MCDisassembler::Fail;
4670   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4671     return MCDisassembler::Fail;
4672   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
4673     return MCDisassembler::Fail;
4674   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4675     return MCDisassembler::Fail;
4676 
4677   return S;
4678 }
4679 
4680 static DecodeStatus DecodeVLD1LN(MCInst &Inst, unsigned Insn,
4681                          uint64_t Address, const void *Decoder) {
4682   DecodeStatus S = MCDisassembler::Success;
4683 
4684   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4685   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4686   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4687   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4688   unsigned size = fieldFromInstruction(Insn, 10, 2);
4689 
4690   unsigned align = 0;
4691   unsigned index = 0;
4692   switch (size) {
4693     default:
4694       return MCDisassembler::Fail;
4695     case 0:
4696       if (fieldFromInstruction(Insn, 4, 1))
4697         return MCDisassembler::Fail; // UNDEFINED
4698       index = fieldFromInstruction(Insn, 5, 3);
4699       break;
4700     case 1:
4701       if (fieldFromInstruction(Insn, 5, 1))
4702         return MCDisassembler::Fail; // UNDEFINED
4703       index = fieldFromInstruction(Insn, 6, 2);
4704       if (fieldFromInstruction(Insn, 4, 1))
4705         align = 2;
4706       break;
4707     case 2:
4708       if (fieldFromInstruction(Insn, 6, 1))
4709         return MCDisassembler::Fail; // UNDEFINED
4710       index = fieldFromInstruction(Insn, 7, 1);
4711 
4712       switch (fieldFromInstruction(Insn, 4, 2)) {
4713         case 0 :
4714           align = 0; break;
4715         case 3:
4716           align = 4; break;
4717         default:
4718           return MCDisassembler::Fail;
4719       }
4720       break;
4721   }
4722 
4723   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4724     return MCDisassembler::Fail;
4725   if (Rm != 0xF) { // Writeback
4726     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4727       return MCDisassembler::Fail;
4728   }
4729   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4730     return MCDisassembler::Fail;
4731   Inst.addOperand(MCOperand::createImm(align));
4732   if (Rm != 0xF) {
4733     if (Rm != 0xD) {
4734       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4735         return MCDisassembler::Fail;
4736     } else
4737       Inst.addOperand(MCOperand::createReg(0));
4738   }
4739 
4740   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4741     return MCDisassembler::Fail;
4742   Inst.addOperand(MCOperand::createImm(index));
4743 
4744   return S;
4745 }
4746 
4747 static DecodeStatus DecodeVST1LN(MCInst &Inst, unsigned Insn,
4748                          uint64_t Address, const void *Decoder) {
4749   DecodeStatus S = MCDisassembler::Success;
4750 
4751   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4752   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4753   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4754   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4755   unsigned size = fieldFromInstruction(Insn, 10, 2);
4756 
4757   unsigned align = 0;
4758   unsigned index = 0;
4759   switch (size) {
4760     default:
4761       return MCDisassembler::Fail;
4762     case 0:
4763       if (fieldFromInstruction(Insn, 4, 1))
4764         return MCDisassembler::Fail; // UNDEFINED
4765       index = fieldFromInstruction(Insn, 5, 3);
4766       break;
4767     case 1:
4768       if (fieldFromInstruction(Insn, 5, 1))
4769         return MCDisassembler::Fail; // UNDEFINED
4770       index = fieldFromInstruction(Insn, 6, 2);
4771       if (fieldFromInstruction(Insn, 4, 1))
4772         align = 2;
4773       break;
4774     case 2:
4775       if (fieldFromInstruction(Insn, 6, 1))
4776         return MCDisassembler::Fail; // UNDEFINED
4777       index = fieldFromInstruction(Insn, 7, 1);
4778 
4779       switch (fieldFromInstruction(Insn, 4, 2)) {
4780         case 0:
4781           align = 0; break;
4782         case 3:
4783           align = 4; break;
4784         default:
4785           return MCDisassembler::Fail;
4786       }
4787       break;
4788   }
4789 
4790   if (Rm != 0xF) { // Writeback
4791     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4792     return MCDisassembler::Fail;
4793   }
4794   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4795     return MCDisassembler::Fail;
4796   Inst.addOperand(MCOperand::createImm(align));
4797   if (Rm != 0xF) {
4798     if (Rm != 0xD) {
4799       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4800     return MCDisassembler::Fail;
4801     } else
4802       Inst.addOperand(MCOperand::createReg(0));
4803   }
4804 
4805   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4806     return MCDisassembler::Fail;
4807   Inst.addOperand(MCOperand::createImm(index));
4808 
4809   return S;
4810 }
4811 
4812 static DecodeStatus DecodeVLD2LN(MCInst &Inst, unsigned Insn,
4813                          uint64_t Address, const void *Decoder) {
4814   DecodeStatus S = MCDisassembler::Success;
4815 
4816   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4817   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4818   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4819   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4820   unsigned size = fieldFromInstruction(Insn, 10, 2);
4821 
4822   unsigned align = 0;
4823   unsigned index = 0;
4824   unsigned inc = 1;
4825   switch (size) {
4826     default:
4827       return MCDisassembler::Fail;
4828     case 0:
4829       index = fieldFromInstruction(Insn, 5, 3);
4830       if (fieldFromInstruction(Insn, 4, 1))
4831         align = 2;
4832       break;
4833     case 1:
4834       index = fieldFromInstruction(Insn, 6, 2);
4835       if (fieldFromInstruction(Insn, 4, 1))
4836         align = 4;
4837       if (fieldFromInstruction(Insn, 5, 1))
4838         inc = 2;
4839       break;
4840     case 2:
4841       if (fieldFromInstruction(Insn, 5, 1))
4842         return MCDisassembler::Fail; // UNDEFINED
4843       index = fieldFromInstruction(Insn, 7, 1);
4844       if (fieldFromInstruction(Insn, 4, 1) != 0)
4845         align = 8;
4846       if (fieldFromInstruction(Insn, 6, 1))
4847         inc = 2;
4848       break;
4849   }
4850 
4851   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4852     return MCDisassembler::Fail;
4853   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4854     return MCDisassembler::Fail;
4855   if (Rm != 0xF) { // Writeback
4856     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4857       return MCDisassembler::Fail;
4858   }
4859   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4860     return MCDisassembler::Fail;
4861   Inst.addOperand(MCOperand::createImm(align));
4862   if (Rm != 0xF) {
4863     if (Rm != 0xD) {
4864       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4865         return MCDisassembler::Fail;
4866     } else
4867       Inst.addOperand(MCOperand::createReg(0));
4868   }
4869 
4870   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4871     return MCDisassembler::Fail;
4872   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4873     return MCDisassembler::Fail;
4874   Inst.addOperand(MCOperand::createImm(index));
4875 
4876   return S;
4877 }
4878 
4879 static DecodeStatus DecodeVST2LN(MCInst &Inst, unsigned Insn,
4880                          uint64_t Address, const void *Decoder) {
4881   DecodeStatus S = MCDisassembler::Success;
4882 
4883   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4884   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4885   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4886   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4887   unsigned size = fieldFromInstruction(Insn, 10, 2);
4888 
4889   unsigned align = 0;
4890   unsigned index = 0;
4891   unsigned inc = 1;
4892   switch (size) {
4893     default:
4894       return MCDisassembler::Fail;
4895     case 0:
4896       index = fieldFromInstruction(Insn, 5, 3);
4897       if (fieldFromInstruction(Insn, 4, 1))
4898         align = 2;
4899       break;
4900     case 1:
4901       index = fieldFromInstruction(Insn, 6, 2);
4902       if (fieldFromInstruction(Insn, 4, 1))
4903         align = 4;
4904       if (fieldFromInstruction(Insn, 5, 1))
4905         inc = 2;
4906       break;
4907     case 2:
4908       if (fieldFromInstruction(Insn, 5, 1))
4909         return MCDisassembler::Fail; // UNDEFINED
4910       index = fieldFromInstruction(Insn, 7, 1);
4911       if (fieldFromInstruction(Insn, 4, 1) != 0)
4912         align = 8;
4913       if (fieldFromInstruction(Insn, 6, 1))
4914         inc = 2;
4915       break;
4916   }
4917 
4918   if (Rm != 0xF) { // Writeback
4919     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4920       return MCDisassembler::Fail;
4921   }
4922   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4923     return MCDisassembler::Fail;
4924   Inst.addOperand(MCOperand::createImm(align));
4925   if (Rm != 0xF) {
4926     if (Rm != 0xD) {
4927       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4928         return MCDisassembler::Fail;
4929     } else
4930       Inst.addOperand(MCOperand::createReg(0));
4931   }
4932 
4933   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4934     return MCDisassembler::Fail;
4935   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4936     return MCDisassembler::Fail;
4937   Inst.addOperand(MCOperand::createImm(index));
4938 
4939   return S;
4940 }
4941 
4942 static DecodeStatus DecodeVLD3LN(MCInst &Inst, unsigned Insn,
4943                          uint64_t Address, const void *Decoder) {
4944   DecodeStatus S = MCDisassembler::Success;
4945 
4946   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4947   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4948   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4949   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4950   unsigned size = fieldFromInstruction(Insn, 10, 2);
4951 
4952   unsigned align = 0;
4953   unsigned index = 0;
4954   unsigned inc = 1;
4955   switch (size) {
4956     default:
4957       return MCDisassembler::Fail;
4958     case 0:
4959       if (fieldFromInstruction(Insn, 4, 1))
4960         return MCDisassembler::Fail; // UNDEFINED
4961       index = fieldFromInstruction(Insn, 5, 3);
4962       break;
4963     case 1:
4964       if (fieldFromInstruction(Insn, 4, 1))
4965         return MCDisassembler::Fail; // UNDEFINED
4966       index = fieldFromInstruction(Insn, 6, 2);
4967       if (fieldFromInstruction(Insn, 5, 1))
4968         inc = 2;
4969       break;
4970     case 2:
4971       if (fieldFromInstruction(Insn, 4, 2))
4972         return MCDisassembler::Fail; // UNDEFINED
4973       index = fieldFromInstruction(Insn, 7, 1);
4974       if (fieldFromInstruction(Insn, 6, 1))
4975         inc = 2;
4976       break;
4977   }
4978 
4979   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4980     return MCDisassembler::Fail;
4981   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4982     return MCDisassembler::Fail;
4983   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
4984     return MCDisassembler::Fail;
4985 
4986   if (Rm != 0xF) { // Writeback
4987     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4988     return MCDisassembler::Fail;
4989   }
4990   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4991     return MCDisassembler::Fail;
4992   Inst.addOperand(MCOperand::createImm(align));
4993   if (Rm != 0xF) {
4994     if (Rm != 0xD) {
4995       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4996     return MCDisassembler::Fail;
4997     } else
4998       Inst.addOperand(MCOperand::createReg(0));
4999   }
5000 
5001   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5002     return MCDisassembler::Fail;
5003   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5004     return MCDisassembler::Fail;
5005   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5006     return MCDisassembler::Fail;
5007   Inst.addOperand(MCOperand::createImm(index));
5008 
5009   return S;
5010 }
5011 
5012 static DecodeStatus DecodeVST3LN(MCInst &Inst, unsigned Insn,
5013                          uint64_t Address, const void *Decoder) {
5014   DecodeStatus S = MCDisassembler::Success;
5015 
5016   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5017   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5018   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5019   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5020   unsigned size = fieldFromInstruction(Insn, 10, 2);
5021 
5022   unsigned align = 0;
5023   unsigned index = 0;
5024   unsigned inc = 1;
5025   switch (size) {
5026     default:
5027       return MCDisassembler::Fail;
5028     case 0:
5029       if (fieldFromInstruction(Insn, 4, 1))
5030         return MCDisassembler::Fail; // UNDEFINED
5031       index = fieldFromInstruction(Insn, 5, 3);
5032       break;
5033     case 1:
5034       if (fieldFromInstruction(Insn, 4, 1))
5035         return MCDisassembler::Fail; // UNDEFINED
5036       index = fieldFromInstruction(Insn, 6, 2);
5037       if (fieldFromInstruction(Insn, 5, 1))
5038         inc = 2;
5039       break;
5040     case 2:
5041       if (fieldFromInstruction(Insn, 4, 2))
5042         return MCDisassembler::Fail; // UNDEFINED
5043       index = fieldFromInstruction(Insn, 7, 1);
5044       if (fieldFromInstruction(Insn, 6, 1))
5045         inc = 2;
5046       break;
5047   }
5048 
5049   if (Rm != 0xF) { // Writeback
5050     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5051     return MCDisassembler::Fail;
5052   }
5053   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5054     return MCDisassembler::Fail;
5055   Inst.addOperand(MCOperand::createImm(align));
5056   if (Rm != 0xF) {
5057     if (Rm != 0xD) {
5058       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5059     return MCDisassembler::Fail;
5060     } else
5061       Inst.addOperand(MCOperand::createReg(0));
5062   }
5063 
5064   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5065     return MCDisassembler::Fail;
5066   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5067     return MCDisassembler::Fail;
5068   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5069     return MCDisassembler::Fail;
5070   Inst.addOperand(MCOperand::createImm(index));
5071 
5072   return S;
5073 }
5074 
5075 static DecodeStatus DecodeVLD4LN(MCInst &Inst, unsigned Insn,
5076                          uint64_t Address, const void *Decoder) {
5077   DecodeStatus S = MCDisassembler::Success;
5078 
5079   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5080   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5081   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5082   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5083   unsigned size = fieldFromInstruction(Insn, 10, 2);
5084 
5085   unsigned align = 0;
5086   unsigned index = 0;
5087   unsigned inc = 1;
5088   switch (size) {
5089     default:
5090       return MCDisassembler::Fail;
5091     case 0:
5092       if (fieldFromInstruction(Insn, 4, 1))
5093         align = 4;
5094       index = fieldFromInstruction(Insn, 5, 3);
5095       break;
5096     case 1:
5097       if (fieldFromInstruction(Insn, 4, 1))
5098         align = 8;
5099       index = fieldFromInstruction(Insn, 6, 2);
5100       if (fieldFromInstruction(Insn, 5, 1))
5101         inc = 2;
5102       break;
5103     case 2:
5104       switch (fieldFromInstruction(Insn, 4, 2)) {
5105         case 0:
5106           align = 0; break;
5107         case 3:
5108           return MCDisassembler::Fail;
5109         default:
5110           align = 4 << fieldFromInstruction(Insn, 4, 2); break;
5111       }
5112 
5113       index = fieldFromInstruction(Insn, 7, 1);
5114       if (fieldFromInstruction(Insn, 6, 1))
5115         inc = 2;
5116       break;
5117   }
5118 
5119   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5120     return MCDisassembler::Fail;
5121   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5122     return MCDisassembler::Fail;
5123   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5124     return MCDisassembler::Fail;
5125   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5126     return MCDisassembler::Fail;
5127 
5128   if (Rm != 0xF) { // Writeback
5129     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5130       return MCDisassembler::Fail;
5131   }
5132   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5133     return MCDisassembler::Fail;
5134   Inst.addOperand(MCOperand::createImm(align));
5135   if (Rm != 0xF) {
5136     if (Rm != 0xD) {
5137       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5138         return MCDisassembler::Fail;
5139     } else
5140       Inst.addOperand(MCOperand::createReg(0));
5141   }
5142 
5143   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5144     return MCDisassembler::Fail;
5145   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5146     return MCDisassembler::Fail;
5147   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5148     return MCDisassembler::Fail;
5149   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5150     return MCDisassembler::Fail;
5151   Inst.addOperand(MCOperand::createImm(index));
5152 
5153   return S;
5154 }
5155 
5156 static DecodeStatus DecodeVST4LN(MCInst &Inst, unsigned Insn,
5157                          uint64_t Address, const void *Decoder) {
5158   DecodeStatus S = MCDisassembler::Success;
5159 
5160   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5161   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5162   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5163   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5164   unsigned size = fieldFromInstruction(Insn, 10, 2);
5165 
5166   unsigned align = 0;
5167   unsigned index = 0;
5168   unsigned inc = 1;
5169   switch (size) {
5170     default:
5171       return MCDisassembler::Fail;
5172     case 0:
5173       if (fieldFromInstruction(Insn, 4, 1))
5174         align = 4;
5175       index = fieldFromInstruction(Insn, 5, 3);
5176       break;
5177     case 1:
5178       if (fieldFromInstruction(Insn, 4, 1))
5179         align = 8;
5180       index = fieldFromInstruction(Insn, 6, 2);
5181       if (fieldFromInstruction(Insn, 5, 1))
5182         inc = 2;
5183       break;
5184     case 2:
5185       switch (fieldFromInstruction(Insn, 4, 2)) {
5186         case 0:
5187           align = 0; break;
5188         case 3:
5189           return MCDisassembler::Fail;
5190         default:
5191           align = 4 << fieldFromInstruction(Insn, 4, 2); break;
5192       }
5193 
5194       index = fieldFromInstruction(Insn, 7, 1);
5195       if (fieldFromInstruction(Insn, 6, 1))
5196         inc = 2;
5197       break;
5198   }
5199 
5200   if (Rm != 0xF) { // Writeback
5201     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5202     return MCDisassembler::Fail;
5203   }
5204   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5205     return MCDisassembler::Fail;
5206   Inst.addOperand(MCOperand::createImm(align));
5207   if (Rm != 0xF) {
5208     if (Rm != 0xD) {
5209       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5210     return MCDisassembler::Fail;
5211     } else
5212       Inst.addOperand(MCOperand::createReg(0));
5213   }
5214 
5215   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5216     return MCDisassembler::Fail;
5217   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5218     return MCDisassembler::Fail;
5219   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5220     return MCDisassembler::Fail;
5221   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5222     return MCDisassembler::Fail;
5223   Inst.addOperand(MCOperand::createImm(index));
5224 
5225   return S;
5226 }
5227 
5228 static DecodeStatus DecodeVMOVSRR(MCInst &Inst, unsigned Insn,
5229                                   uint64_t Address, const void *Decoder) {
5230   DecodeStatus S = MCDisassembler::Success;
5231   unsigned Rt  = fieldFromInstruction(Insn, 12, 4);
5232   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
5233   unsigned Rm  = fieldFromInstruction(Insn,  5, 1);
5234   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5235   Rm |= fieldFromInstruction(Insn, 0, 4) << 1;
5236 
5237   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
5238     S = MCDisassembler::SoftFail;
5239 
5240   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
5241     return MCDisassembler::Fail;
5242   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
5243     return MCDisassembler::Fail;
5244   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
5245     return MCDisassembler::Fail;
5246   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
5247     return MCDisassembler::Fail;
5248   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5249     return MCDisassembler::Fail;
5250 
5251   return S;
5252 }
5253 
5254 static DecodeStatus DecodeVMOVRRS(MCInst &Inst, unsigned Insn,
5255                                   uint64_t Address, const void *Decoder) {
5256   DecodeStatus S = MCDisassembler::Success;
5257   unsigned Rt  = fieldFromInstruction(Insn, 12, 4);
5258   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
5259   unsigned Rm  = fieldFromInstruction(Insn,  5, 1);
5260   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5261   Rm |= fieldFromInstruction(Insn, 0, 4) << 1;
5262 
5263   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
5264     S = MCDisassembler::SoftFail;
5265 
5266   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
5267     return MCDisassembler::Fail;
5268   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
5269     return MCDisassembler::Fail;
5270   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
5271     return MCDisassembler::Fail;
5272   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
5273     return MCDisassembler::Fail;
5274   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5275     return MCDisassembler::Fail;
5276 
5277   return S;
5278 }
5279 
5280 static DecodeStatus DecodeIT(MCInst &Inst, unsigned Insn,
5281                              uint64_t Address, const void *Decoder) {
5282   DecodeStatus S = MCDisassembler::Success;
5283   unsigned pred = fieldFromInstruction(Insn, 4, 4);
5284   unsigned mask = fieldFromInstruction(Insn, 0, 4);
5285 
5286   if (pred == 0xF) {
5287     pred = 0xE;
5288     S = MCDisassembler::SoftFail;
5289   }
5290 
5291   if (mask == 0x0)
5292     return MCDisassembler::Fail;
5293 
5294   // IT masks are encoded as a sequence of replacement low-order bits
5295   // for the condition code. So if the low bit of the starting
5296   // condition code is 1, then we have to flip all the bits above the
5297   // terminating bit (which is the lowest 1 bit).
5298   if (pred & 1) {
5299     unsigned LowBit = mask & -mask;
5300     unsigned BitsAboveLowBit = 0xF & (-LowBit << 1);
5301     mask ^= BitsAboveLowBit;
5302   }
5303 
5304   Inst.addOperand(MCOperand::createImm(pred));
5305   Inst.addOperand(MCOperand::createImm(mask));
5306   return S;
5307 }
5308 
5309 static DecodeStatus
5310 DecodeT2LDRDPreInstruction(MCInst &Inst, unsigned Insn,
5311                            uint64_t Address, const void *Decoder) {
5312   DecodeStatus S = MCDisassembler::Success;
5313 
5314   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5315   unsigned Rt2 = fieldFromInstruction(Insn, 8, 4);
5316   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5317   unsigned addr = fieldFromInstruction(Insn, 0, 8);
5318   unsigned W = fieldFromInstruction(Insn, 21, 1);
5319   unsigned U = fieldFromInstruction(Insn, 23, 1);
5320   unsigned P = fieldFromInstruction(Insn, 24, 1);
5321   bool writeback = (W == 1) | (P == 0);
5322 
5323   addr |= (U << 8) | (Rn << 9);
5324 
5325   if (writeback && (Rn == Rt || Rn == Rt2))
5326     Check(S, MCDisassembler::SoftFail);
5327   if (Rt == Rt2)
5328     Check(S, MCDisassembler::SoftFail);
5329 
5330   // Rt
5331   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
5332     return MCDisassembler::Fail;
5333   // Rt2
5334   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
5335     return MCDisassembler::Fail;
5336   // Writeback operand
5337   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
5338     return MCDisassembler::Fail;
5339   // addr
5340   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
5341     return MCDisassembler::Fail;
5342 
5343   return S;
5344 }
5345 
5346 static DecodeStatus
5347 DecodeT2STRDPreInstruction(MCInst &Inst, unsigned Insn,
5348                            uint64_t Address, const void *Decoder) {
5349   DecodeStatus S = MCDisassembler::Success;
5350 
5351   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5352   unsigned Rt2 = fieldFromInstruction(Insn, 8, 4);
5353   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5354   unsigned addr = fieldFromInstruction(Insn, 0, 8);
5355   unsigned W = fieldFromInstruction(Insn, 21, 1);
5356   unsigned U = fieldFromInstruction(Insn, 23, 1);
5357   unsigned P = fieldFromInstruction(Insn, 24, 1);
5358   bool writeback = (W == 1) | (P == 0);
5359 
5360   addr |= (U << 8) | (Rn << 9);
5361 
5362   if (writeback && (Rn == Rt || Rn == Rt2))
5363     Check(S, MCDisassembler::SoftFail);
5364 
5365   // Writeback operand
5366   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
5367     return MCDisassembler::Fail;
5368   // Rt
5369   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
5370     return MCDisassembler::Fail;
5371   // Rt2
5372   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
5373     return MCDisassembler::Fail;
5374   // addr
5375   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
5376     return MCDisassembler::Fail;
5377 
5378   return S;
5379 }
5380 
5381 static DecodeStatus DecodeT2Adr(MCInst &Inst, uint32_t Insn,
5382                                 uint64_t Address, const void *Decoder) {
5383   unsigned sign1 = fieldFromInstruction(Insn, 21, 1);
5384   unsigned sign2 = fieldFromInstruction(Insn, 23, 1);
5385   if (sign1 != sign2) return MCDisassembler::Fail;
5386 
5387   unsigned Val = fieldFromInstruction(Insn, 0, 8);
5388   Val |= fieldFromInstruction(Insn, 12, 3) << 8;
5389   Val |= fieldFromInstruction(Insn, 26, 1) << 11;
5390   Val |= sign1 << 12;
5391   Inst.addOperand(MCOperand::createImm(SignExtend32<13>(Val)));
5392 
5393   return MCDisassembler::Success;
5394 }
5395 
5396 static DecodeStatus DecodeT2ShifterImmOperand(MCInst &Inst, uint32_t Val,
5397                                               uint64_t Address,
5398                                               const void *Decoder) {
5399   DecodeStatus S = MCDisassembler::Success;
5400 
5401   // Shift of "asr #32" is not allowed in Thumb2 mode.
5402   if (Val == 0x20) S = MCDisassembler::Fail;
5403   Inst.addOperand(MCOperand::createImm(Val));
5404   return S;
5405 }
5406 
5407 static DecodeStatus DecodeSwap(MCInst &Inst, unsigned Insn,
5408                                uint64_t Address, const void *Decoder) {
5409   unsigned Rt   = fieldFromInstruction(Insn, 12, 4);
5410   unsigned Rt2  = fieldFromInstruction(Insn, 0,  4);
5411   unsigned Rn   = fieldFromInstruction(Insn, 16, 4);
5412   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5413 
5414   if (pred == 0xF)
5415     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
5416 
5417   DecodeStatus S = MCDisassembler::Success;
5418 
5419   if (Rt == Rn || Rn == Rt2)
5420     S = MCDisassembler::SoftFail;
5421 
5422   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5423     return MCDisassembler::Fail;
5424   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5425     return MCDisassembler::Fail;
5426   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
5427     return MCDisassembler::Fail;
5428   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5429     return MCDisassembler::Fail;
5430 
5431   return S;
5432 }
5433 
5434 static DecodeStatus DecodeVCVTD(MCInst &Inst, unsigned Insn,
5435                                 uint64_t Address, const void *Decoder) {
5436   const FeatureBitset &featureBits =
5437       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5438   bool hasFullFP16 = featureBits[ARM::FeatureFullFP16];
5439 
5440   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5441   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5442   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5443   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5444   unsigned imm = fieldFromInstruction(Insn, 16, 6);
5445   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
5446   unsigned op = fieldFromInstruction(Insn, 5, 1);
5447 
5448   DecodeStatus S = MCDisassembler::Success;
5449 
5450   // If the top 3 bits of imm are clear, this is a VMOV (immediate)
5451   if (!(imm & 0x38)) {
5452     if (cmode == 0xF) {
5453       if (op == 1) return MCDisassembler::Fail;
5454       Inst.setOpcode(ARM::VMOVv2f32);
5455     }
5456     if (hasFullFP16) {
5457       if (cmode == 0xE) {
5458         if (op == 1) {
5459           Inst.setOpcode(ARM::VMOVv1i64);
5460         } else {
5461           Inst.setOpcode(ARM::VMOVv8i8);
5462         }
5463       }
5464       if (cmode == 0xD) {
5465         if (op == 1) {
5466           Inst.setOpcode(ARM::VMVNv2i32);
5467         } else {
5468           Inst.setOpcode(ARM::VMOVv2i32);
5469         }
5470       }
5471       if (cmode == 0xC) {
5472         if (op == 1) {
5473           Inst.setOpcode(ARM::VMVNv2i32);
5474         } else {
5475           Inst.setOpcode(ARM::VMOVv2i32);
5476         }
5477       }
5478     }
5479     return DecodeNEONModImmInstruction(Inst, Insn, Address, Decoder);
5480   }
5481 
5482   if (!(imm & 0x20)) return MCDisassembler::Fail;
5483 
5484   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
5485     return MCDisassembler::Fail;
5486   if (!Check(S, DecodeDPRRegisterClass(Inst, Vm, Address, Decoder)))
5487     return MCDisassembler::Fail;
5488   Inst.addOperand(MCOperand::createImm(64 - imm));
5489 
5490   return S;
5491 }
5492 
5493 static DecodeStatus DecodeVCVTQ(MCInst &Inst, unsigned Insn,
5494                                 uint64_t Address, const void *Decoder) {
5495   const FeatureBitset &featureBits =
5496       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5497   bool hasFullFP16 = featureBits[ARM::FeatureFullFP16];
5498 
5499   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5500   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5501   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5502   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5503   unsigned imm = fieldFromInstruction(Insn, 16, 6);
5504   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
5505   unsigned op = fieldFromInstruction(Insn, 5, 1);
5506 
5507   DecodeStatus S = MCDisassembler::Success;
5508 
5509   // If the top 3 bits of imm are clear, this is a VMOV (immediate)
5510   if (!(imm & 0x38)) {
5511     if (cmode == 0xF) {
5512       if (op == 1) return MCDisassembler::Fail;
5513       Inst.setOpcode(ARM::VMOVv4f32);
5514     }
5515     if (hasFullFP16) {
5516       if (cmode == 0xE) {
5517         if (op == 1) {
5518           Inst.setOpcode(ARM::VMOVv2i64);
5519         } else {
5520           Inst.setOpcode(ARM::VMOVv16i8);
5521         }
5522       }
5523       if (cmode == 0xD) {
5524         if (op == 1) {
5525           Inst.setOpcode(ARM::VMVNv4i32);
5526         } else {
5527           Inst.setOpcode(ARM::VMOVv4i32);
5528         }
5529       }
5530       if (cmode == 0xC) {
5531         if (op == 1) {
5532           Inst.setOpcode(ARM::VMVNv4i32);
5533         } else {
5534           Inst.setOpcode(ARM::VMOVv4i32);
5535         }
5536       }
5537     }
5538     return DecodeNEONModImmInstruction(Inst, Insn, Address, Decoder);
5539   }
5540 
5541   if (!(imm & 0x20)) return MCDisassembler::Fail;
5542 
5543   if (!Check(S, DecodeQPRRegisterClass(Inst, Vd, Address, Decoder)))
5544     return MCDisassembler::Fail;
5545   if (!Check(S, DecodeQPRRegisterClass(Inst, Vm, Address, Decoder)))
5546     return MCDisassembler::Fail;
5547   Inst.addOperand(MCOperand::createImm(64 - imm));
5548 
5549   return S;
5550 }
5551 
5552 static DecodeStatus DecodeNEONComplexLane64Instruction(MCInst &Inst,
5553                                                        unsigned Insn,
5554                                                        uint64_t Address,
5555                                                        const void *Decoder) {
5556   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5557   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5558   unsigned Vn = (fieldFromInstruction(Insn, 16, 4) << 0);
5559   Vn |= (fieldFromInstruction(Insn, 7, 1) << 4);
5560   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5561   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5562   unsigned q = (fieldFromInstruction(Insn, 6, 1) << 0);
5563   unsigned rotate = (fieldFromInstruction(Insn, 20, 2) << 0);
5564 
5565   DecodeStatus S = MCDisassembler::Success;
5566 
5567   auto DestRegDecoder = q ? DecodeQPRRegisterClass : DecodeDPRRegisterClass;
5568 
5569   if (!Check(S, DestRegDecoder(Inst, Vd, Address, Decoder)))
5570     return MCDisassembler::Fail;
5571   if (!Check(S, DestRegDecoder(Inst, Vd, Address, Decoder)))
5572     return MCDisassembler::Fail;
5573   if (!Check(S, DestRegDecoder(Inst, Vn, Address, Decoder)))
5574     return MCDisassembler::Fail;
5575   if (!Check(S, DecodeDPRRegisterClass(Inst, Vm, Address, Decoder)))
5576     return MCDisassembler::Fail;
5577   // The lane index does not have any bits in the encoding, because it can only
5578   // be 0.
5579   Inst.addOperand(MCOperand::createImm(0));
5580   Inst.addOperand(MCOperand::createImm(rotate));
5581 
5582   return S;
5583 }
5584 
5585 static DecodeStatus DecodeLDR(MCInst &Inst, unsigned Val,
5586                                 uint64_t Address, const void *Decoder) {
5587   DecodeStatus S = MCDisassembler::Success;
5588 
5589   unsigned Rn = fieldFromInstruction(Val, 16, 4);
5590   unsigned Rt = fieldFromInstruction(Val, 12, 4);
5591   unsigned Rm = fieldFromInstruction(Val, 0, 4);
5592   Rm |= (fieldFromInstruction(Val, 23, 1) << 4);
5593   unsigned Cond = fieldFromInstruction(Val, 28, 4);
5594 
5595   if (fieldFromInstruction(Val, 8, 4) != 0 || Rn == Rt)
5596     S = MCDisassembler::SoftFail;
5597 
5598   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5599     return MCDisassembler::Fail;
5600   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
5601     return MCDisassembler::Fail;
5602   if (!Check(S, DecodeAddrMode7Operand(Inst, Rn, Address, Decoder)))
5603     return MCDisassembler::Fail;
5604   if (!Check(S, DecodePostIdxReg(Inst, Rm, Address, Decoder)))
5605     return MCDisassembler::Fail;
5606   if (!Check(S, DecodePredicateOperand(Inst, Cond, Address, Decoder)))
5607     return MCDisassembler::Fail;
5608 
5609   return S;
5610 }
5611 
5612 static DecodeStatus DecoderForMRRC2AndMCRR2(MCInst &Inst, unsigned Val,
5613                                             uint64_t Address, const void *Decoder) {
5614   DecodeStatus S = MCDisassembler::Success;
5615 
5616   unsigned CRm = fieldFromInstruction(Val, 0, 4);
5617   unsigned opc1 = fieldFromInstruction(Val, 4, 4);
5618   unsigned cop = fieldFromInstruction(Val, 8, 4);
5619   unsigned Rt = fieldFromInstruction(Val, 12, 4);
5620   unsigned Rt2 = fieldFromInstruction(Val, 16, 4);
5621 
5622   if ((cop & ~0x1) == 0xa)
5623     return MCDisassembler::Fail;
5624 
5625   if (Rt == Rt2)
5626     S = MCDisassembler::SoftFail;
5627 
5628   // We have to check if the instruction is MRRC2
5629   // or MCRR2 when constructing the operands for
5630   // Inst. Reason is because MRRC2 stores to two
5631   // registers so it's tablegen desc has has two
5632   // outputs whereas MCRR doesn't store to any
5633   // registers so all of it's operands are listed
5634   // as inputs, therefore the operand order for
5635   // MRRC2 needs to be [Rt, Rt2, cop, opc1, CRm]
5636   // and MCRR2 operand order is [cop, opc1, Rt, Rt2, CRm]
5637 
5638   if (Inst.getOpcode() == ARM::MRRC2) {
5639     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5640       return MCDisassembler::Fail;
5641     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5642       return MCDisassembler::Fail;
5643   }
5644   Inst.addOperand(MCOperand::createImm(cop));
5645   Inst.addOperand(MCOperand::createImm(opc1));
5646   if (Inst.getOpcode() == ARM::MCRR2) {
5647     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5648       return MCDisassembler::Fail;
5649     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5650       return MCDisassembler::Fail;
5651   }
5652   Inst.addOperand(MCOperand::createImm(CRm));
5653 
5654   return S;
5655 }
5656 
5657 static DecodeStatus DecodeForVMRSandVMSR(MCInst &Inst, unsigned Val,
5658                                          uint64_t Address,
5659                                          const void *Decoder) {
5660   const FeatureBitset &featureBits =
5661       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5662   DecodeStatus S = MCDisassembler::Success;
5663 
5664   // Add explicit operand for the destination sysreg, for cases where
5665   // we have to model it for code generation purposes.
5666   switch (Inst.getOpcode()) {
5667   case ARM::VMSR_FPSCR_NZCVQC:
5668     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
5669     break;
5670   case ARM::VMSR_P0:
5671     Inst.addOperand(MCOperand::createReg(ARM::VPR));
5672     break;
5673   }
5674 
5675   if (Inst.getOpcode() != ARM::FMSTAT) {
5676     unsigned Rt = fieldFromInstruction(Val, 12, 4);
5677 
5678     if (featureBits[ARM::ModeThumb] && !featureBits[ARM::HasV8Ops]) {
5679       if (Rt == 13 || Rt == 15)
5680         S = MCDisassembler::SoftFail;
5681       Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder));
5682     } else
5683       Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder));
5684   }
5685 
5686   // Add explicit operand for the source sysreg, similarly to above.
5687   switch (Inst.getOpcode()) {
5688   case ARM::VMRS_FPSCR_NZCVQC:
5689     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
5690     break;
5691   case ARM::VMRS_P0:
5692     Inst.addOperand(MCOperand::createReg(ARM::VPR));
5693     break;
5694   }
5695 
5696   if (featureBits[ARM::ModeThumb]) {
5697     Inst.addOperand(MCOperand::createImm(ARMCC::AL));
5698     Inst.addOperand(MCOperand::createReg(0));
5699   } else {
5700     unsigned pred = fieldFromInstruction(Val, 28, 4);
5701     if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5702       return MCDisassembler::Fail;
5703   }
5704 
5705   return S;
5706 }
5707 
5708 template <bool isSigned, bool isNeg, int size>
5709 static DecodeStatus DecodeBFLabelOperand(MCInst &Inst, unsigned Val,
5710                                          uint64_t Address,
5711                                          const void *Decoder) {
5712   DecodeStatus S = MCDisassembler::Success;
5713   if (Val == 0)
5714     S = MCDisassembler::SoftFail;
5715 
5716   uint64_t DecVal;
5717   if (isSigned)
5718     DecVal = SignExtend32<size + 1>(Val << 1);
5719   else
5720     DecVal = (Val << 1);
5721 
5722   if (!tryAddingSymbolicOperand(Address, Address + DecVal + 4, true, 4, Inst,
5723                                 Decoder))
5724     Inst.addOperand(MCOperand::createImm(isNeg ? -DecVal : DecVal));
5725   return S;
5726 }
5727 
5728 static DecodeStatus DecodeBFAfterTargetOperand(MCInst &Inst, unsigned Val,
5729                                                uint64_t Address,
5730                                                const void *Decoder) {
5731 
5732   uint64_t LocImm = Inst.getOperand(0).getImm();
5733   Val = LocImm + (2 << Val);
5734   if (!tryAddingSymbolicOperand(Address, Address + Val + 4, true, 4, Inst,
5735                                 Decoder))
5736     Inst.addOperand(MCOperand::createImm(Val));
5737   return MCDisassembler::Success;
5738 }
5739 
5740 static DecodeStatus DecodePredNoALOperand(MCInst &Inst, unsigned Val,
5741                                           uint64_t Address,
5742                                           const void *Decoder) {
5743   if (Val >= ARMCC::AL)  // also exclude the non-condition NV
5744     return MCDisassembler::Fail;
5745   Inst.addOperand(MCOperand::createImm(Val));
5746   return MCDisassembler::Success;
5747 }
5748 
5749 static DecodeStatus DecodeLOLoop(MCInst &Inst, unsigned Insn, uint64_t Address,
5750                                  const void *Decoder) {
5751   DecodeStatus S = MCDisassembler::Success;
5752 
5753   unsigned Imm = fieldFromInstruction(Insn, 11, 1) |
5754                  fieldFromInstruction(Insn, 1, 10) << 1;
5755   switch (Inst.getOpcode()) {
5756   case ARM::t2LEUpdate:
5757     Inst.addOperand(MCOperand::createReg(ARM::LR));
5758     Inst.addOperand(MCOperand::createReg(ARM::LR));
5759     LLVM_FALLTHROUGH;
5760   case ARM::t2LE:
5761     if (!Check(S, DecodeBFLabelOperand<false, true, 11>(Inst, Imm, Address,
5762                                                         Decoder)))
5763       return MCDisassembler::Fail;
5764     break;
5765   case ARM::t2WLS:
5766     Inst.addOperand(MCOperand::createReg(ARM::LR));
5767     if (!Check(S,
5768                DecoderGPRRegisterClass(Inst, fieldFromInstruction(Insn, 16, 4),
5769                                        Address, Decoder)) ||
5770         !Check(S, DecodeBFLabelOperand<false, false, 11>(Inst, Imm, Address,
5771                                                          Decoder)))
5772       return MCDisassembler::Fail;
5773     break;
5774   case ARM::t2DLS:
5775     unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5776     if (Rn == 0xF) {
5777       return MCDisassembler::Fail;
5778     } else {
5779       Inst.addOperand(MCOperand::createReg(ARM::LR));
5780       if (!Check(S, DecoderGPRRegisterClass(Inst,
5781                                             fieldFromInstruction(Insn, 16, 4),
5782                                             Address, Decoder)))
5783         return MCDisassembler::Fail;
5784     }
5785     break;
5786   }
5787   return S;
5788 }
5789 
5790 static DecodeStatus DecodeLongShiftOperand(MCInst &Inst, unsigned Val,
5791                                            uint64_t Address,
5792                                            const void *Decoder) {
5793   DecodeStatus S = MCDisassembler::Success;
5794 
5795   if (Val == 0)
5796     Val = 32;
5797 
5798   Inst.addOperand(MCOperand::createImm(Val));
5799 
5800   return S;
5801 }
5802 
5803 static DecodeStatus DecodetGPROddRegisterClass(MCInst &Inst, unsigned RegNo,
5804                                    uint64_t Address, const void *Decoder) {
5805   if ((RegNo) + 1 > 11)
5806     return MCDisassembler::Fail;
5807 
5808   unsigned Register = GPRDecoderTable[(RegNo) + 1];
5809   Inst.addOperand(MCOperand::createReg(Register));
5810   return MCDisassembler::Success;
5811 }
5812 
5813 static DecodeStatus DecodetGPREvenRegisterClass(MCInst &Inst, unsigned RegNo,
5814                                    uint64_t Address, const void *Decoder) {
5815   if ((RegNo) > 14)
5816     return MCDisassembler::Fail;
5817 
5818   unsigned Register = GPRDecoderTable[(RegNo)];
5819   Inst.addOperand(MCOperand::createReg(Register));
5820   return MCDisassembler::Success;
5821 }
5822 
5823 static DecodeStatus DecodeVSCCLRM(MCInst &Inst, unsigned Insn, uint64_t Address,
5824                                   const void *Decoder) {
5825   DecodeStatus S = MCDisassembler::Success;
5826 
5827   Inst.addOperand(MCOperand::createImm(ARMCC::AL));
5828   Inst.addOperand(MCOperand::createReg(0));
5829   if (Inst.getOpcode() == ARM::VSCCLRMD) {
5830     unsigned reglist = (fieldFromInstruction(Insn, 1, 7) << 1) |
5831                        (fieldFromInstruction(Insn, 12, 4) << 8) |
5832                        (fieldFromInstruction(Insn, 22, 1) << 12);
5833     if (!Check(S, DecodeDPRRegListOperand(Inst, reglist, Address, Decoder))) {
5834       return MCDisassembler::Fail;
5835     }
5836   } else {
5837     unsigned reglist = fieldFromInstruction(Insn, 0, 8) |
5838                        (fieldFromInstruction(Insn, 22, 1) << 8) |
5839                        (fieldFromInstruction(Insn, 12, 4) << 9);
5840     if (!Check(S, DecodeSPRRegListOperand(Inst, reglist, Address, Decoder))) {
5841       return MCDisassembler::Fail;
5842     }
5843   }
5844   Inst.addOperand(MCOperand::createReg(ARM::VPR));
5845 
5846   return S;
5847 }
5848 
5849 static DecodeStatus DecodeMQPRRegisterClass(MCInst &Inst, unsigned RegNo,
5850                               uint64_t Address,
5851                               const void *Decoder) {
5852   if (RegNo > 7)
5853     return MCDisassembler::Fail;
5854 
5855   unsigned Register = QPRDecoderTable[RegNo];
5856   Inst.addOperand(MCOperand::createReg(Register));
5857   return MCDisassembler::Success;
5858 }
5859 
5860 static DecodeStatus DecodeVPTMaskOperand(MCInst &Inst, unsigned Val,
5861                                          uint64_t Address,
5862                                          const void *Decoder) {
5863   DecodeStatus S = MCDisassembler::Success;
5864 
5865   // Parse VPT mask and encode it in the MCInst as an immediate with the same
5866   // format as the it_mask.  That is, from the second 'e|t' encode 'e' as 1 and
5867   // 't' as 0 and finish with a 1.
5868   unsigned Imm = 0;
5869   // We always start with a 't'.
5870   unsigned CurBit = 0;
5871   for (int i = 3; i >= 0; --i) {
5872     // If the bit we are looking at is not the same as last one, invert the
5873     // CurBit, if it is the same leave it as is.
5874     CurBit ^= (Val >> i) & 1U;
5875 
5876     // Encode the CurBit at the right place in the immediate.
5877     Imm |= (CurBit << i);
5878 
5879     // If we are done, finish the encoding with a 1.
5880     if ((Val & ~(~0U << i)) == 0) {
5881       Imm |= 1U << i;
5882       break;
5883     }
5884   }
5885 
5886   Inst.addOperand(MCOperand::createImm(Imm));
5887 
5888   return S;
5889 }
5890 
5891 static DecodeStatus DecodeVpredROperand(MCInst &Inst, unsigned RegNo,
5892                                         uint64_t Address, const void *Decoder) {
5893   // The vpred_r operand type includes an MQPR register field derived
5894   // from the encoding. But we don't actually want to add an operand
5895   // to the MCInst at this stage, because AddThumbPredicate will do it
5896   // later, and will infer the register number from the TIED_TO
5897   // constraint. So this is a deliberately empty decoder method that
5898   // will inhibit the auto-generated disassembly code from adding an
5899   // operand at all.
5900   return MCDisassembler::Success;
5901 }
5902 
5903 static DecodeStatus DecodeRestrictedIPredicateOperand(MCInst &Inst,
5904                                                       unsigned Val,
5905                                                       uint64_t Address,
5906                                                       const void *Decoder) {
5907   Inst.addOperand(MCOperand::createImm((Val & 0x1) == 0 ? ARMCC::EQ : ARMCC::NE));
5908   return MCDisassembler::Success;
5909 }
5910 
5911 static DecodeStatus DecodeRestrictedSPredicateOperand(MCInst &Inst,
5912                                                       unsigned Val,
5913                                                       uint64_t Address,
5914                                                       const void *Decoder) {
5915   unsigned Code;
5916   switch (Val & 0x3) {
5917   case 0:
5918     Code = ARMCC::GE;
5919     break;
5920   case 1:
5921     Code = ARMCC::LT;
5922     break;
5923   case 2:
5924     Code = ARMCC::GT;
5925     break;
5926   case 3:
5927     Code = ARMCC::LE;
5928     break;
5929   }
5930   Inst.addOperand(MCOperand::createImm(Code));
5931   return MCDisassembler::Success;
5932 }
5933 
5934 static DecodeStatus DecodeRestrictedUPredicateOperand(MCInst &Inst,
5935                                                       unsigned Val,
5936                                                       uint64_t Address,
5937                                                       const void *Decoder) {
5938   Inst.addOperand(MCOperand::createImm((Val & 0x1) == 0 ? ARMCC::HS : ARMCC::HI));
5939   return MCDisassembler::Success;
5940 }
5941 
5942 static DecodeStatus DecodeRestrictedFPPredicateOperand(MCInst &Inst, unsigned Val,
5943                                                      uint64_t Address,
5944                                                      const void *Decoder) {
5945   unsigned Code;
5946   switch (Val) {
5947   default:
5948     return MCDisassembler::Fail;
5949   case 0:
5950     Code = ARMCC::EQ;
5951     break;
5952   case 1:
5953     Code = ARMCC::NE;
5954     break;
5955   case 4:
5956     Code = ARMCC::GE;
5957     break;
5958   case 5:
5959     Code = ARMCC::LT;
5960     break;
5961   case 6:
5962     Code = ARMCC::GT;
5963     break;
5964   case 7:
5965     Code = ARMCC::LE;
5966     break;
5967   }
5968 
5969   Inst.addOperand(MCOperand::createImm(Code));
5970   return MCDisassembler::Success;
5971 }
5972 
5973 static unsigned FixedRegForVSTRVLDR_SYSREG(unsigned Opcode) {
5974   switch (Opcode) {
5975   case ARM::VSTR_P0_off:
5976   case ARM::VSTR_P0_pre:
5977   case ARM::VSTR_P0_post:
5978   case ARM::VLDR_P0_off:
5979   case ARM::VLDR_P0_pre:
5980   case ARM::VLDR_P0_post:
5981     return ARM::P0;
5982   default:
5983     return 0;
5984   }
5985 }
5986 
5987 template<bool Writeback>
5988 static DecodeStatus DecodeVSTRVLDR_SYSREG(MCInst &Inst, unsigned Val,
5989                                           uint64_t Address,
5990                                           const void *Decoder) {
5991   switch (Inst.getOpcode()) {
5992   case ARM::VSTR_FPSCR_pre:
5993   case ARM::VSTR_FPSCR_NZCVQC_pre:
5994   case ARM::VLDR_FPSCR_pre:
5995   case ARM::VLDR_FPSCR_NZCVQC_pre:
5996   case ARM::VSTR_FPSCR_off:
5997   case ARM::VSTR_FPSCR_NZCVQC_off:
5998   case ARM::VLDR_FPSCR_off:
5999   case ARM::VLDR_FPSCR_NZCVQC_off:
6000   case ARM::VSTR_FPSCR_post:
6001   case ARM::VSTR_FPSCR_NZCVQC_post:
6002   case ARM::VLDR_FPSCR_post:
6003   case ARM::VLDR_FPSCR_NZCVQC_post:
6004     const FeatureBitset &featureBits =
6005         ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
6006 
6007     if (!featureBits[ARM::HasMVEIntegerOps] && !featureBits[ARM::FeatureVFP2])
6008       return MCDisassembler::Fail;
6009   }
6010 
6011   DecodeStatus S = MCDisassembler::Success;
6012   if (unsigned Sysreg = FixedRegForVSTRVLDR_SYSREG(Inst.getOpcode()))
6013     Inst.addOperand(MCOperand::createReg(Sysreg));
6014   unsigned Rn = fieldFromInstruction(Val, 16, 4);
6015   unsigned addr = fieldFromInstruction(Val, 0, 7) |
6016                   (fieldFromInstruction(Val, 23, 1) << 7) | (Rn << 8);
6017 
6018   if (Writeback) {
6019     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
6020       return MCDisassembler::Fail;
6021   }
6022   if (!Check(S, DecodeT2AddrModeImm7s4(Inst, addr, Address, Decoder)))
6023     return MCDisassembler::Fail;
6024 
6025   Inst.addOperand(MCOperand::createImm(ARMCC::AL));
6026   Inst.addOperand(MCOperand::createReg(0));
6027 
6028   return S;
6029 }
6030 
6031 template <int shift>
6032 static DecodeStatus DecodeExpandedImmOperand(MCInst &Inst, unsigned Val,
6033                                              uint64_t Address,
6034                                              const void *Decoder) {
6035     Val <<= shift;
6036 
6037     Inst.addOperand(MCOperand::createImm(Val));
6038     return MCDisassembler::Success;
6039 }
6040 
6041 static DecodeStatus DecodeMVEOverlappingLongShift(
6042   MCInst &Inst, unsigned Insn, uint64_t Address, const void *Decoder) {
6043   DecodeStatus S = MCDisassembler::Success;
6044 
6045   unsigned RdaLo = fieldFromInstruction(Insn, 17, 3) << 1;
6046   unsigned RdaHi = fieldFromInstruction(Insn, 9, 3) << 1;
6047   unsigned Rm = fieldFromInstruction(Insn, 12, 4);
6048 
6049   if (RdaHi == 14) {
6050     // This value of RdaHi (really indicating pc, because RdaHi has to
6051     // be an odd-numbered register, so the low bit will be set by the
6052     // decode function below) indicates that we must decode as SQRSHR
6053     // or UQRSHL, which both have a single Rda register field with all
6054     // four bits.
6055     unsigned Rda = fieldFromInstruction(Insn, 16, 4);
6056 
6057     switch (Inst.getOpcode()) {
6058       case ARM::MVE_ASRLr:
6059       case ARM::MVE_SQRSHRL:
6060         Inst.setOpcode(ARM::MVE_SQRSHR);
6061         break;
6062       case ARM::MVE_LSLLr:
6063       case ARM::MVE_UQRSHLL:
6064         Inst.setOpcode(ARM::MVE_UQRSHL);
6065         break;
6066       default:
6067         llvm_unreachable("Unexpected starting opcode!");
6068     }
6069 
6070     // Rda as output parameter
6071     if (!Check(S, DecoderGPRRegisterClass(Inst, Rda, Address, Decoder)))
6072       return MCDisassembler::Fail;
6073 
6074     // Rda again as input parameter
6075     if (!Check(S, DecoderGPRRegisterClass(Inst, Rda, Address, Decoder)))
6076       return MCDisassembler::Fail;
6077 
6078     // Rm, the amount to shift by
6079     if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
6080       return MCDisassembler::Fail;
6081 
6082     return S;
6083   }
6084 
6085   // Otherwise, we decode as whichever opcode our caller has already
6086   // put into Inst. Those all look the same:
6087 
6088   // RdaLo,RdaHi as output parameters
6089   if (!Check(S, DecodetGPREvenRegisterClass(Inst, RdaLo, Address, Decoder)))
6090     return MCDisassembler::Fail;
6091   if (!Check(S, DecodetGPROddRegisterClass(Inst, RdaHi, Address, Decoder)))
6092     return MCDisassembler::Fail;
6093 
6094   // RdaLo,RdaHi again as input parameters
6095   if (!Check(S, DecodetGPREvenRegisterClass(Inst, RdaLo, Address, Decoder)))
6096     return MCDisassembler::Fail;
6097   if (!Check(S, DecodetGPROddRegisterClass(Inst, RdaHi, Address, Decoder)))
6098     return MCDisassembler::Fail;
6099 
6100   // Rm, the amount to shift by
6101   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
6102     return MCDisassembler::Fail;
6103 
6104   return S;
6105 }
6106