xref: /freebsd-src/contrib/llvm-project/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp (revision 5e801ac66d24704442eba426ed13c3effb8a34e7)
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/MC/TargetRegistry.h"
23 #include "llvm/Support/Compiler.h"
24 #include "llvm/Support/ErrorHandling.h"
25 #include "llvm/Support/MathExtras.h"
26 #include "llvm/Support/raw_ostream.h"
27 #include <algorithm>
28 #include <cassert>
29 #include <cstdint>
30 #include <vector>
31 
32 using namespace llvm;
33 
34 #define DEBUG_TYPE "arm-disassembler"
35 
36 using DecodeStatus = MCDisassembler::DecodeStatus;
37 
38 namespace {
39 
40   // Handles the condition code status of instructions in IT blocks
41   class ITStatus
42   {
43     public:
44       // Returns the condition code for instruction in IT block
45       unsigned getITCC() {
46         unsigned CC = ARMCC::AL;
47         if (instrInITBlock())
48           CC = ITStates.back();
49         return CC;
50       }
51 
52       // Advances the IT block state to the next T or E
53       void advanceITState() {
54         ITStates.pop_back();
55       }
56 
57       // Returns true if the current instruction is in an IT block
58       bool instrInITBlock() {
59         return !ITStates.empty();
60       }
61 
62       // Returns true if current instruction is the last instruction in an IT block
63       bool instrLastInITBlock() {
64         return ITStates.size() == 1;
65       }
66 
67       // Called when decoding an IT instruction. Sets the IT state for
68       // the following instructions that for the IT block. Firstcond
69       // corresponds to the field in the IT instruction encoding; Mask
70       // is in the MCOperand format in which 1 means 'else' and 0 'then'.
71       void setITState(char Firstcond, char Mask) {
72         // (3 - the number of trailing zeros) is the number of then / else.
73         unsigned NumTZ = countTrailingZeros<uint8_t>(Mask);
74         unsigned char CCBits = static_cast<unsigned char>(Firstcond & 0xf);
75         assert(NumTZ <= 3 && "Invalid IT mask!");
76         // push condition codes onto the stack the correct order for the pops
77         for (unsigned Pos = NumTZ+1; Pos <= 3; ++Pos) {
78           unsigned Else = (Mask >> Pos) & 1;
79           ITStates.push_back(CCBits ^ Else);
80         }
81         ITStates.push_back(CCBits);
82       }
83 
84     private:
85       std::vector<unsigned char> ITStates;
86   };
87 
88   class VPTStatus
89   {
90     public:
91       unsigned getVPTPred() {
92         unsigned Pred = ARMVCC::None;
93         if (instrInVPTBlock())
94           Pred = VPTStates.back();
95         return Pred;
96       }
97 
98       void advanceVPTState() {
99         VPTStates.pop_back();
100       }
101 
102       bool instrInVPTBlock() {
103         return !VPTStates.empty();
104       }
105 
106       bool instrLastInVPTBlock() {
107         return VPTStates.size() == 1;
108       }
109 
110       void setVPTState(char Mask) {
111         // (3 - the number of trailing zeros) is the number of then / else.
112         unsigned NumTZ = countTrailingZeros<uint8_t>(Mask);
113         assert(NumTZ <= 3 && "Invalid VPT mask!");
114         // push predicates onto the stack the correct order for the pops
115         for (unsigned Pos = NumTZ+1; Pos <= 3; ++Pos) {
116           bool T = ((Mask >> Pos) & 1) == 0;
117           if (T)
118             VPTStates.push_back(ARMVCC::Then);
119           else
120             VPTStates.push_back(ARMVCC::Else);
121         }
122         VPTStates.push_back(ARMVCC::Then);
123       }
124 
125     private:
126       SmallVector<unsigned char, 4> VPTStates;
127   };
128 
129 /// ARM disassembler for all ARM platforms.
130 class ARMDisassembler : public MCDisassembler {
131 public:
132   ARMDisassembler(const MCSubtargetInfo &STI, MCContext &Ctx) :
133     MCDisassembler(STI, Ctx) {
134   }
135 
136   ~ARMDisassembler() override = default;
137 
138   DecodeStatus getInstruction(MCInst &Instr, uint64_t &Size,
139                               ArrayRef<uint8_t> Bytes, uint64_t Address,
140                               raw_ostream &CStream) const override;
141 
142 private:
143   DecodeStatus getARMInstruction(MCInst &Instr, uint64_t &Size,
144                                  ArrayRef<uint8_t> Bytes, uint64_t Address,
145                                  raw_ostream &CStream) const;
146 
147   DecodeStatus getThumbInstruction(MCInst &Instr, uint64_t &Size,
148                                    ArrayRef<uint8_t> Bytes, uint64_t Address,
149                                    raw_ostream &CStream) const;
150 
151   mutable ITStatus ITBlock;
152   mutable VPTStatus VPTBlock;
153 
154   DecodeStatus AddThumbPredicate(MCInst&) const;
155   void UpdateThumbVFPPredicate(DecodeStatus &, MCInst&) const;
156 };
157 
158 } // end anonymous namespace
159 
160 static bool Check(DecodeStatus &Out, DecodeStatus In) {
161   switch (In) {
162     case MCDisassembler::Success:
163       // Out stays the same.
164       return true;
165     case MCDisassembler::SoftFail:
166       Out = In;
167       return true;
168     case MCDisassembler::Fail:
169       Out = In;
170       return false;
171   }
172   llvm_unreachable("Invalid DecodeStatus!");
173 }
174 
175 // Forward declare these because the autogenerated code will reference them.
176 // Definitions are further down.
177 static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, unsigned RegNo,
178                                    uint64_t Address, const void *Decoder);
179 static DecodeStatus DecodeCLRMGPRRegisterClass(MCInst &Inst, unsigned RegNo,
180                                    uint64_t Address, const void *Decoder);
181 static DecodeStatus DecodetGPROddRegisterClass(MCInst &Inst, unsigned RegNo,
182                                    uint64_t Address, const void *Decoder);
183 static DecodeStatus DecodetGPREvenRegisterClass(MCInst &Inst, unsigned RegNo,
184                                    uint64_t Address, const void *Decoder);
185 static DecodeStatus
186 DecodeGPRwithAPSR_NZCVnospRegisterClass(MCInst &Inst, unsigned RegNo,
187                                         uint64_t Address, const void *Decoder);
188 static DecodeStatus DecodeGPRnopcRegisterClass(MCInst &Inst,
189                                                unsigned RegNo, uint64_t Address,
190                                                const void *Decoder);
191 static DecodeStatus DecodeGPRwithAPSRRegisterClass(MCInst &Inst,
192                                                unsigned RegNo, uint64_t Address,
193                                                const void *Decoder);
194 static DecodeStatus DecodeGPRwithZRRegisterClass(MCInst &Inst,
195                                                unsigned RegNo, uint64_t Address,
196                                                const void *Decoder);
197 static DecodeStatus DecodeGPRwithZRnospRegisterClass(
198     MCInst &Inst, unsigned RegNo, uint64_t Address, const void *Decoder);
199 static DecodeStatus DecodetGPRRegisterClass(MCInst &Inst, unsigned RegNo,
200                                    uint64_t Address, const void *Decoder);
201 static DecodeStatus DecodetcGPRRegisterClass(MCInst &Inst, unsigned RegNo,
202                                    uint64_t Address, const void *Decoder);
203 static DecodeStatus DecoderGPRRegisterClass(MCInst &Inst, unsigned RegNo,
204                                    uint64_t Address, const void *Decoder);
205 static DecodeStatus DecodeGPRPairRegisterClass(MCInst &Inst, unsigned RegNo,
206                                    uint64_t Address, const void *Decoder);
207 static DecodeStatus DecodeGPRPairnospRegisterClass(MCInst &Inst, unsigned RegNo,
208                                    uint64_t Address, const void *Decoder);
209 static DecodeStatus DecodeGPRspRegisterClass(MCInst &Inst, unsigned RegNo,
210                                              uint64_t Address,
211                                              const void *Decoder);
212 static DecodeStatus DecodeHPRRegisterClass(MCInst &Inst, unsigned RegNo,
213                                    uint64_t Address, const void *Decoder);
214 static DecodeStatus DecodeSPRRegisterClass(MCInst &Inst, unsigned RegNo,
215                                    uint64_t Address, const void *Decoder);
216 static DecodeStatus DecodeDPRRegisterClass(MCInst &Inst, unsigned RegNo,
217                                    uint64_t Address, const void *Decoder);
218 static DecodeStatus DecodeDPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
219                                    uint64_t Address, const void *Decoder);
220 static DecodeStatus DecodeSPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
221                                    uint64_t Address, const void *Decoder);
222 static DecodeStatus DecodeDPR_VFP2RegisterClass(MCInst &Inst,
223                                                 unsigned RegNo,
224                                                 uint64_t Address,
225                                                 const void *Decoder);
226 static DecodeStatus DecodeQPRRegisterClass(MCInst &Inst, unsigned RegNo,
227                                    uint64_t Address, const void *Decoder);
228 static DecodeStatus DecodeMQPRRegisterClass(MCInst &Inst, unsigned RegNo,
229                                    uint64_t Address, const void *Decoder);
230 static DecodeStatus DecodeMQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
231                                              uint64_t Address,
232                                              const void *Decoder);
233 static DecodeStatus DecodeMQQQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
234                                                uint64_t Address,
235                                                const void *Decoder);
236 static DecodeStatus DecodeDPairRegisterClass(MCInst &Inst, unsigned RegNo,
237                                    uint64_t Address, const void *Decoder);
238 static DecodeStatus DecodeDPairSpacedRegisterClass(MCInst &Inst,
239                                unsigned RegNo, uint64_t Address,
240                                const void *Decoder);
241 
242 static DecodeStatus DecodePredicateOperand(MCInst &Inst, unsigned Val,
243                                uint64_t Address, const void *Decoder);
244 static DecodeStatus DecodeCCOutOperand(MCInst &Inst, unsigned Val,
245                                uint64_t Address, const void *Decoder);
246 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Val,
247                                uint64_t Address, const void *Decoder);
248 static DecodeStatus DecodeSPRRegListOperand(MCInst &Inst, unsigned Val,
249                                uint64_t Address, const void *Decoder);
250 static DecodeStatus DecodeDPRRegListOperand(MCInst &Inst, unsigned Val,
251                                uint64_t Address, const void *Decoder);
252 
253 static DecodeStatus DecodeBitfieldMaskOperand(MCInst &Inst, unsigned Insn,
254                                uint64_t Address, const void *Decoder);
255 static DecodeStatus DecodeCopMemInstruction(MCInst &Inst, unsigned Insn,
256                                uint64_t Address, const void *Decoder);
257 static DecodeStatus DecodeAddrMode2IdxInstruction(MCInst &Inst,
258                                                   unsigned Insn,
259                                                   uint64_t Address,
260                                                   const void *Decoder);
261 static DecodeStatus DecodeSORegMemOperand(MCInst &Inst, unsigned Insn,
262                                uint64_t Address, const void *Decoder);
263 static DecodeStatus DecodeAddrMode3Instruction(MCInst &Inst,unsigned Insn,
264                                uint64_t Address, const void *Decoder);
265 static DecodeStatus DecodeSORegImmOperand(MCInst &Inst, unsigned Insn,
266                                uint64_t Address, const void *Decoder);
267 static DecodeStatus DecodeSORegRegOperand(MCInst &Inst, unsigned Insn,
268                                uint64_t Address, const void *Decoder);
269 
270 static DecodeStatus DecodeMemMultipleWritebackInstruction(MCInst & Inst,
271                                                   unsigned Insn,
272                                                   uint64_t Adddress,
273                                                   const void *Decoder);
274 static DecodeStatus DecodeT2MOVTWInstruction(MCInst &Inst, unsigned Insn,
275                                uint64_t Address, const void *Decoder);
276 static DecodeStatus DecodeArmMOVTWInstruction(MCInst &Inst, unsigned Insn,
277                                uint64_t Address, const void *Decoder);
278 static DecodeStatus DecodeSMLAInstruction(MCInst &Inst, unsigned Insn,
279                                uint64_t Address, const void *Decoder);
280 static DecodeStatus DecodeHINTInstruction(MCInst &Inst, unsigned Insn,
281                                uint64_t Address, const void *Decoder);
282 static DecodeStatus DecodeCPSInstruction(MCInst &Inst, unsigned Insn,
283                                uint64_t Address, const void *Decoder);
284 static DecodeStatus DecodeTSTInstruction(MCInst &Inst, unsigned Insn,
285                                uint64_t Address, const void *Decoder);
286 static DecodeStatus DecodeSETPANInstruction(MCInst &Inst, unsigned Insn,
287                                uint64_t Address, const void *Decoder);
288 static DecodeStatus DecodeT2CPSInstruction(MCInst &Inst, unsigned Insn,
289                                uint64_t Address, const void *Decoder);
290 static DecodeStatus DecodeAddrModeImm12Operand(MCInst &Inst, unsigned Val,
291                                uint64_t Address, const void *Decoder);
292 static DecodeStatus DecodeAddrMode5Operand(MCInst &Inst, unsigned Val,
293                                uint64_t Address, const void *Decoder);
294 static DecodeStatus DecodeAddrMode5FP16Operand(MCInst &Inst, unsigned Val,
295                                uint64_t Address, const void *Decoder);
296 static DecodeStatus DecodeAddrMode7Operand(MCInst &Inst, unsigned Val,
297                                uint64_t Address, const void *Decoder);
298 static DecodeStatus DecodeT2BInstruction(MCInst &Inst, unsigned Insn,
299                                uint64_t Address, const void *Decoder);
300 static DecodeStatus DecodeBranchImmInstruction(MCInst &Inst,unsigned Insn,
301                                uint64_t Address, const void *Decoder);
302 static DecodeStatus DecodeAddrMode6Operand(MCInst &Inst, unsigned Val,
303                                uint64_t Address, const void *Decoder);
304 static DecodeStatus DecodeVLDST1Instruction(MCInst &Inst, unsigned Val,
305                                uint64_t Address, const void *Decoder);
306 static DecodeStatus DecodeVLDST2Instruction(MCInst &Inst, unsigned Val,
307                                uint64_t Address, const void *Decoder);
308 static DecodeStatus DecodeVLDST3Instruction(MCInst &Inst, unsigned Val,
309                                uint64_t Address, const void *Decoder);
310 static DecodeStatus DecodeVLDST4Instruction(MCInst &Inst, unsigned Val,
311                                uint64_t Address, const void *Decoder);
312 static DecodeStatus DecodeVLDInstruction(MCInst &Inst, unsigned Val,
313                                uint64_t Address, const void *Decoder);
314 static DecodeStatus DecodeVSTInstruction(MCInst &Inst, unsigned Val,
315                                uint64_t Address, const void *Decoder);
316 static DecodeStatus DecodeVLD1DupInstruction(MCInst &Inst, unsigned Val,
317                                uint64_t Address, const void *Decoder);
318 static DecodeStatus DecodeVLD2DupInstruction(MCInst &Inst, unsigned Val,
319                                uint64_t Address, const void *Decoder);
320 static DecodeStatus DecodeVLD3DupInstruction(MCInst &Inst, unsigned Val,
321                                uint64_t Address, const void *Decoder);
322 static DecodeStatus DecodeVLD4DupInstruction(MCInst &Inst, unsigned Val,
323                                uint64_t Address, const void *Decoder);
324 static DecodeStatus DecodeVMOVModImmInstruction(MCInst &Inst,unsigned Val,
325                                uint64_t Address, const void *Decoder);
326 static DecodeStatus DecodeMVEModImmInstruction(MCInst &Inst,unsigned Val,
327                                uint64_t Address, const void *Decoder);
328 static DecodeStatus DecodeMVEVADCInstruction(MCInst &Inst, unsigned Insn,
329                                uint64_t Address, const void *Decoder);
330 static DecodeStatus DecodeVSHLMaxInstruction(MCInst &Inst, unsigned Val,
331                                uint64_t Address, const void *Decoder);
332 static DecodeStatus DecodeShiftRight8Imm(MCInst &Inst, unsigned Val,
333                                uint64_t Address, const void *Decoder);
334 static DecodeStatus DecodeShiftRight16Imm(MCInst &Inst, unsigned Val,
335                                uint64_t Address, const void *Decoder);
336 static DecodeStatus DecodeShiftRight32Imm(MCInst &Inst, unsigned Val,
337                                uint64_t Address, const void *Decoder);
338 static DecodeStatus DecodeShiftRight64Imm(MCInst &Inst, unsigned Val,
339                                uint64_t Address, const void *Decoder);
340 static DecodeStatus DecodeTBLInstruction(MCInst &Inst, unsigned Insn,
341                                uint64_t Address, const void *Decoder);
342 static DecodeStatus DecodePostIdxReg(MCInst &Inst, unsigned Insn,
343                                uint64_t Address, const void *Decoder);
344 static DecodeStatus DecodeMveAddrModeRQ(MCInst &Inst, unsigned Insn,
345                                uint64_t Address, const void *Decoder);
346 template<int shift>
347 static DecodeStatus DecodeMveAddrModeQ(MCInst &Inst, unsigned Insn,
348                                uint64_t Address, const void *Decoder);
349 static DecodeStatus DecodeCoprocessor(MCInst &Inst, unsigned Insn,
350                                uint64_t Address, const void *Decoder);
351 static DecodeStatus DecodeMemBarrierOption(MCInst &Inst, unsigned Insn,
352                                uint64_t Address, const void *Decoder);
353 static DecodeStatus DecodeInstSyncBarrierOption(MCInst &Inst, unsigned Insn,
354                                uint64_t Address, const void *Decoder);
355 static DecodeStatus DecodeMSRMask(MCInst &Inst, unsigned Insn,
356                                uint64_t Address, const void *Decoder);
357 static DecodeStatus DecodeBankedReg(MCInst &Inst, unsigned Insn,
358                                uint64_t Address, const void *Decoder);
359 static DecodeStatus DecodeDoubleRegLoad(MCInst &Inst, unsigned Insn,
360                                uint64_t Address, const void *Decoder);
361 static DecodeStatus DecodeDoubleRegStore(MCInst &Inst, unsigned Insn,
362                                uint64_t Address, const void *Decoder);
363 static DecodeStatus DecodeLDRPreImm(MCInst &Inst, unsigned Insn,
364                                uint64_t Address, const void *Decoder);
365 static DecodeStatus DecodeLDRPreReg(MCInst &Inst, unsigned Insn,
366                                uint64_t Address, const void *Decoder);
367 static DecodeStatus DecodeSTRPreImm(MCInst &Inst, unsigned Insn,
368                                uint64_t Address, const void *Decoder);
369 static DecodeStatus DecodeSTRPreReg(MCInst &Inst, unsigned Insn,
370                                uint64_t Address, const void *Decoder);
371 static DecodeStatus DecodeVLD1LN(MCInst &Inst, unsigned Insn,
372                                uint64_t Address, const void *Decoder);
373 static DecodeStatus DecodeVLD2LN(MCInst &Inst, unsigned Insn,
374                                uint64_t Address, const void *Decoder);
375 static DecodeStatus DecodeVLD3LN(MCInst &Inst, unsigned Insn,
376                                uint64_t Address, const void *Decoder);
377 static DecodeStatus DecodeVLD4LN(MCInst &Inst, unsigned Insn,
378                                uint64_t Address, const void *Decoder);
379 static DecodeStatus DecodeVST1LN(MCInst &Inst, unsigned Insn,
380                                uint64_t Address, const void *Decoder);
381 static DecodeStatus DecodeVST2LN(MCInst &Inst, unsigned Insn,
382                                uint64_t Address, const void *Decoder);
383 static DecodeStatus DecodeVST3LN(MCInst &Inst, unsigned Insn,
384                                uint64_t Address, const void *Decoder);
385 static DecodeStatus DecodeVST4LN(MCInst &Inst, unsigned Insn,
386                                uint64_t Address, const void *Decoder);
387 static DecodeStatus DecodeVMOVSRR(MCInst &Inst, unsigned Insn,
388                                uint64_t Address, const void *Decoder);
389 static DecodeStatus DecodeVMOVRRS(MCInst &Inst, unsigned Insn,
390                                uint64_t Address, const void *Decoder);
391 static DecodeStatus DecodeSwap(MCInst &Inst, unsigned Insn,
392                                uint64_t Address, const void *Decoder);
393 static DecodeStatus DecodeVCVTD(MCInst &Inst, unsigned Insn,
394                                 uint64_t Address, const void *Decoder);
395 static DecodeStatus DecodeVCVTQ(MCInst &Inst, unsigned Insn,
396                                 uint64_t Address, const void *Decoder);
397 static DecodeStatus DecodeVCVTImmOperand(MCInst &Inst, unsigned Insn,
398                                          uint64_t Address, const void *Decoder);
399 static DecodeStatus DecodeNEONComplexLane64Instruction(MCInst &Inst,
400                                                        unsigned Val,
401                                                        uint64_t Address,
402                                                        const void *Decoder);
403 
404 static DecodeStatus DecodeThumbAddSpecialReg(MCInst &Inst, uint16_t Insn,
405                                uint64_t Address, const void *Decoder);
406 static DecodeStatus DecodeThumbBROperand(MCInst &Inst, unsigned Val,
407                                uint64_t Address, const void *Decoder);
408 static DecodeStatus DecodeT2BROperand(MCInst &Inst, unsigned Val,
409                                uint64_t Address, const void *Decoder);
410 static DecodeStatus DecodeThumbCmpBROperand(MCInst &Inst, unsigned Val,
411                                uint64_t Address, const void *Decoder);
412 static DecodeStatus DecodeThumbAddrModeRR(MCInst &Inst, unsigned Val,
413                                uint64_t Address, const void *Decoder);
414 static DecodeStatus DecodeThumbAddrModeIS(MCInst &Inst, unsigned Val,
415                                uint64_t Address, const void *Decoder);
416 static DecodeStatus DecodeThumbAddrModePC(MCInst &Inst, unsigned Val,
417                                uint64_t Address, const void *Decoder);
418 static DecodeStatus DecodeThumbAddrModeSP(MCInst &Inst, unsigned Val,
419                                uint64_t Address, const void *Decoder);
420 static DecodeStatus DecodeT2AddrModeSOReg(MCInst &Inst, unsigned Val,
421                                uint64_t Address, const void *Decoder);
422 static DecodeStatus DecodeT2LoadShift(MCInst &Inst, unsigned Val,
423                                uint64_t Address, const void *Decoder);
424 static DecodeStatus DecodeT2LoadImm8(MCInst &Inst, unsigned Insn,
425                                uint64_t Address, const void* Decoder);
426 static DecodeStatus DecodeT2LoadImm12(MCInst &Inst, unsigned Insn,
427                                uint64_t Address, const void* Decoder);
428 static DecodeStatus DecodeT2LoadT(MCInst &Inst, unsigned Insn,
429                                uint64_t Address, const void* Decoder);
430 static DecodeStatus DecodeT2LoadLabel(MCInst &Inst, unsigned Insn,
431                                uint64_t Address, const void* Decoder);
432 static DecodeStatus DecodeT2Imm8S4(MCInst &Inst, unsigned Val,
433                                uint64_t Address, const void *Decoder);
434 static DecodeStatus DecodeT2Imm7S4(MCInst &Inst, unsigned Val,
435                                uint64_t Address, const void *Decoder);
436 static DecodeStatus DecodeT2AddrModeImm8s4(MCInst &Inst, unsigned Val,
437                                uint64_t Address, const void *Decoder);
438 static DecodeStatus DecodeT2AddrModeImm7s4(MCInst &Inst, unsigned Val,
439                                            uint64_t Address,
440                                            const void *Decoder);
441 static DecodeStatus DecodeT2AddrModeImm0_1020s4(MCInst &Inst,unsigned Val,
442                                uint64_t Address, const void *Decoder);
443 static DecodeStatus DecodeT2Imm8(MCInst &Inst, unsigned Val,
444                                uint64_t Address, const void *Decoder);
445 template<int shift>
446 static DecodeStatus DecodeT2Imm7(MCInst &Inst, unsigned Val,
447                                uint64_t Address, const void *Decoder);
448 static DecodeStatus DecodeT2AddrModeImm8(MCInst &Inst, unsigned Val,
449                                uint64_t Address, const void *Decoder);
450 template<int shift>
451 static DecodeStatus DecodeTAddrModeImm7(MCInst &Inst, unsigned Val,
452                                uint64_t Address, const void *Decoder);
453 template<int shift, int WriteBack>
454 static DecodeStatus DecodeT2AddrModeImm7(MCInst &Inst, unsigned Val,
455                                uint64_t Address, const void *Decoder);
456 static DecodeStatus DecodeThumbAddSPImm(MCInst &Inst, uint16_t Val,
457                                uint64_t Address, const void *Decoder);
458 static DecodeStatus DecodeThumbAddSPReg(MCInst &Inst, uint16_t Insn,
459                                 uint64_t Address, const void *Decoder);
460 static DecodeStatus DecodeThumbCPS(MCInst &Inst, uint16_t Insn,
461                                 uint64_t Address, const void *Decoder);
462 static DecodeStatus DecodeQADDInstruction(MCInst &Inst, unsigned Insn,
463                                 uint64_t Address, const void *Decoder);
464 static DecodeStatus DecodeThumbBLXOffset(MCInst &Inst, unsigned Insn,
465                                 uint64_t Address, const void *Decoder);
466 static DecodeStatus DecodeT2AddrModeImm12(MCInst &Inst, unsigned Val,
467                                 uint64_t Address, const void *Decoder);
468 static DecodeStatus DecodeThumbTableBranch(MCInst &Inst, unsigned Val,
469                                 uint64_t Address, const void *Decoder);
470 static DecodeStatus DecodeThumb2BCCInstruction(MCInst &Inst, unsigned Val,
471                                 uint64_t Address, const void *Decoder);
472 static DecodeStatus DecodeT2SOImm(MCInst &Inst, unsigned Val,
473                                 uint64_t Address, const void *Decoder);
474 static DecodeStatus DecodeThumbBCCTargetOperand(MCInst &Inst,unsigned Val,
475                                 uint64_t Address, const void *Decoder);
476 static DecodeStatus DecodeThumbBLTargetOperand(MCInst &Inst, unsigned Val,
477                                 uint64_t Address, const void *Decoder);
478 static DecodeStatus DecodeIT(MCInst &Inst, unsigned Val,
479                                 uint64_t Address, const void *Decoder);
480 static DecodeStatus DecodeT2LDRDPreInstruction(MCInst &Inst,unsigned Insn,
481                                uint64_t Address, const void *Decoder);
482 static DecodeStatus DecodeT2STRDPreInstruction(MCInst &Inst,unsigned Insn,
483                                uint64_t Address, const void *Decoder);
484 static DecodeStatus DecodeT2Adr(MCInst &Inst, unsigned Val,
485                                 uint64_t Address, const void *Decoder);
486 static DecodeStatus DecodeT2LdStPre(MCInst &Inst, unsigned Val,
487                                 uint64_t Address, const void *Decoder);
488 static DecodeStatus DecodeT2ShifterImmOperand(MCInst &Inst, unsigned Val,
489                                 uint64_t Address, const void *Decoder);
490 
491 static DecodeStatus DecodeLDR(MCInst &Inst, unsigned Val,
492                                 uint64_t Address, const void *Decoder);
493 static DecodeStatus DecoderForMRRC2AndMCRR2(MCInst &Inst, unsigned Val,
494                                             uint64_t Address, const void *Decoder);
495 static DecodeStatus DecodeForVMRSandVMSR(MCInst &Inst, unsigned Val,
496                                          uint64_t Address, const void *Decoder);
497 
498 template <bool isSigned, bool isNeg, bool zeroPermitted, int size>
499 static DecodeStatus DecodeBFLabelOperand(MCInst &Inst, unsigned val,
500                                          uint64_t Address, const void *Decoder);
501 static DecodeStatus DecodeBFAfterTargetOperand(MCInst &Inst, unsigned val,
502                                                uint64_t Address,
503                                                const void *Decoder);
504 static DecodeStatus DecodePredNoALOperand(MCInst &Inst, unsigned Val,
505                                           uint64_t Address,
506                                           const void *Decoder);
507 static DecodeStatus DecodeLOLoop(MCInst &Inst, unsigned Insn, uint64_t Address,
508                                  const void *Decoder);
509 static DecodeStatus DecodeLongShiftOperand(MCInst &Inst, unsigned Val,
510                                            uint64_t Address,
511                                            const void *Decoder);
512 static DecodeStatus DecodeVSCCLRM(MCInst &Inst, unsigned Insn, uint64_t Address,
513                                   const void *Decoder);
514 static DecodeStatus DecodeVPTMaskOperand(MCInst &Inst, unsigned Val,
515                                          uint64_t Address, const void *Decoder);
516 static DecodeStatus DecodeVpredROperand(MCInst &Inst, unsigned Val,
517                                         uint64_t Address, const void *Decoder);
518 static DecodeStatus DecodeRestrictedIPredicateOperand(MCInst &Inst, unsigned Val,
519                                                      uint64_t Address,
520                                                      const void *Decoder);
521 static DecodeStatus DecodeRestrictedSPredicateOperand(MCInst &Inst, unsigned Val,
522                                                      uint64_t Address,
523                                                      const void *Decoder);
524 static DecodeStatus DecodeRestrictedUPredicateOperand(MCInst &Inst, unsigned Val,
525                                                      uint64_t Address,
526                                                      const void *Decoder);
527 static DecodeStatus DecodeRestrictedFPPredicateOperand(MCInst &Inst,
528                                                        unsigned Val,
529                                                        uint64_t Address,
530                                                        const void *Decoder);
531 template<bool Writeback>
532 static DecodeStatus DecodeVSTRVLDR_SYSREG(MCInst &Inst, unsigned Insn,
533                                           uint64_t Address,
534                                           const void *Decoder);
535 template<int shift>
536 static DecodeStatus DecodeMVE_MEM_1_pre(MCInst &Inst, unsigned Val,
537                                         uint64_t Address, const void *Decoder);
538 template<int shift>
539 static DecodeStatus DecodeMVE_MEM_2_pre(MCInst &Inst, unsigned Val,
540                                         uint64_t Address, const void *Decoder);
541 template<int shift>
542 static DecodeStatus DecodeMVE_MEM_3_pre(MCInst &Inst, unsigned Val,
543                                         uint64_t Address, const void *Decoder);
544 template<unsigned MinLog, unsigned MaxLog>
545 static DecodeStatus DecodePowerTwoOperand(MCInst &Inst, unsigned Val,
546                                           uint64_t Address,
547                                           const void *Decoder);
548 template<unsigned start>
549 static DecodeStatus DecodeMVEPairVectorIndexOperand(MCInst &Inst, unsigned Val,
550                                                     uint64_t Address,
551                                                     const void *Decoder);
552 static DecodeStatus DecodeMVEVMOVQtoDReg(MCInst &Inst, unsigned Insn,
553                                          uint64_t Address,
554                                          const void *Decoder);
555 static DecodeStatus DecodeMVEVMOVDRegtoQ(MCInst &Inst, unsigned Insn,
556                                          uint64_t Address,
557                                          const void *Decoder);
558 static DecodeStatus DecodeMVEVCVTt1fp(MCInst &Inst, unsigned Insn,
559                                       uint64_t Address, const void *Decoder);
560 typedef DecodeStatus OperandDecoder(MCInst &Inst, unsigned Val,
561                                     uint64_t Address, const void *Decoder);
562 template<bool scalar, OperandDecoder predicate_decoder>
563 static DecodeStatus DecodeMVEVCMP(MCInst &Inst, unsigned Insn,
564                                   uint64_t Address, const void *Decoder);
565 static DecodeStatus DecodeMveVCTP(MCInst &Inst, unsigned Insn,
566                                   uint64_t Address, const void *Decoder);
567 static DecodeStatus DecodeMVEVPNOT(MCInst &Inst, unsigned Insn,
568                                    uint64_t Address, const void *Decoder);
569 static DecodeStatus DecodeMVEOverlappingLongShift(MCInst &Inst, unsigned Insn,
570                                                   uint64_t Address,
571                                                   const void *Decoder);
572 static DecodeStatus DecodeT2AddSubSPImm(MCInst &Inst, unsigned Insn,
573                                         uint64_t Address, const void *Decoder);
574 
575 #include "ARMGenDisassemblerTables.inc"
576 
577 static MCDisassembler *createARMDisassembler(const Target &T,
578                                              const MCSubtargetInfo &STI,
579                                              MCContext &Ctx) {
580   return new ARMDisassembler(STI, Ctx);
581 }
582 
583 // Post-decoding checks
584 static DecodeStatus checkDecodedInstruction(MCInst &MI, uint64_t &Size,
585                                             uint64_t Address, raw_ostream &CS,
586                                             uint32_t Insn,
587                                             DecodeStatus Result) {
588   switch (MI.getOpcode()) {
589     case ARM::HVC: {
590       // HVC is undefined if condition = 0xf otherwise upredictable
591       // if condition != 0xe
592       uint32_t Cond = (Insn >> 28) & 0xF;
593       if (Cond == 0xF)
594         return MCDisassembler::Fail;
595       if (Cond != 0xE)
596         return MCDisassembler::SoftFail;
597       return Result;
598     }
599     case ARM::t2ADDri:
600     case ARM::t2ADDri12:
601     case ARM::t2ADDrr:
602     case ARM::t2ADDrs:
603     case ARM::t2SUBri:
604     case ARM::t2SUBri12:
605     case ARM::t2SUBrr:
606     case ARM::t2SUBrs:
607       if (MI.getOperand(0).getReg() == ARM::SP &&
608           MI.getOperand(1).getReg() != ARM::SP)
609         return MCDisassembler::SoftFail;
610       return Result;
611     default: return Result;
612   }
613 }
614 
615 DecodeStatus ARMDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
616                                              ArrayRef<uint8_t> Bytes,
617                                              uint64_t Address,
618                                              raw_ostream &CS) const {
619   if (STI.getFeatureBits()[ARM::ModeThumb])
620     return getThumbInstruction(MI, Size, Bytes, Address, CS);
621   return getARMInstruction(MI, Size, Bytes, Address, CS);
622 }
623 
624 DecodeStatus ARMDisassembler::getARMInstruction(MCInst &MI, uint64_t &Size,
625                                                 ArrayRef<uint8_t> Bytes,
626                                                 uint64_t Address,
627                                                 raw_ostream &CS) const {
628   CommentStream = &CS;
629 
630   assert(!STI.getFeatureBits()[ARM::ModeThumb] &&
631          "Asked to disassemble an ARM instruction but Subtarget is in Thumb "
632          "mode!");
633 
634   // We want to read exactly 4 bytes of data.
635   if (Bytes.size() < 4) {
636     Size = 0;
637     return MCDisassembler::Fail;
638   }
639 
640   // Encoded as a small-endian 32-bit word in the stream.
641   uint32_t Insn =
642       (Bytes[3] << 24) | (Bytes[2] << 16) | (Bytes[1] << 8) | (Bytes[0] << 0);
643 
644   // Calling the auto-generated decoder function.
645   DecodeStatus Result =
646       decodeInstruction(DecoderTableARM32, MI, Insn, Address, this, STI);
647   if (Result != MCDisassembler::Fail) {
648     Size = 4;
649     return checkDecodedInstruction(MI, Size, Address, CS, Insn, Result);
650   }
651 
652   struct DecodeTable {
653     const uint8_t *P;
654     bool DecodePred;
655   };
656 
657   const DecodeTable Tables[] = {
658       {DecoderTableVFP32, false},      {DecoderTableVFPV832, false},
659       {DecoderTableNEONData32, true},  {DecoderTableNEONLoadStore32, true},
660       {DecoderTableNEONDup32, true},   {DecoderTablev8NEON32, false},
661       {DecoderTablev8Crypto32, false},
662   };
663 
664   for (auto Table : Tables) {
665     Result = decodeInstruction(Table.P, MI, Insn, Address, this, STI);
666     if (Result != MCDisassembler::Fail) {
667       Size = 4;
668       // Add a fake predicate operand, because we share these instruction
669       // definitions with Thumb2 where these instructions are predicable.
670       if (Table.DecodePred && !DecodePredicateOperand(MI, 0xE, Address, this))
671         return MCDisassembler::Fail;
672       return Result;
673     }
674   }
675 
676   Result =
677       decodeInstruction(DecoderTableCoProc32, MI, Insn, Address, this, STI);
678   if (Result != MCDisassembler::Fail) {
679     Size = 4;
680     return checkDecodedInstruction(MI, Size, Address, CS, Insn, Result);
681   }
682 
683   Size = 4;
684   return MCDisassembler::Fail;
685 }
686 
687 namespace llvm {
688 
689 extern const MCInstrDesc ARMInsts[];
690 
691 } // end namespace llvm
692 
693 /// tryAddingSymbolicOperand - trys to add a symbolic operand in place of the
694 /// immediate Value in the MCInst.  The immediate Value has had any PC
695 /// adjustment made by the caller.  If the instruction is a branch instruction
696 /// then isBranch is true, else false.  If the getOpInfo() function was set as
697 /// part of the setupForSymbolicDisassembly() call then that function is called
698 /// to get any symbolic information at the Address for this instruction.  If
699 /// that returns non-zero then the symbolic information it returns is used to
700 /// create an MCExpr and that is added as an operand to the MCInst.  If
701 /// getOpInfo() returns zero and isBranch is true then a symbol look up for
702 /// Value is done and if a symbol is found an MCExpr is created with that, else
703 /// an MCExpr with Value is created.  This function returns true if it adds an
704 /// operand to the MCInst and false otherwise.
705 static bool tryAddingSymbolicOperand(uint64_t Address, int32_t Value,
706                                      bool isBranch, uint64_t InstSize,
707                                      MCInst &MI, const void *Decoder) {
708   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
709   // FIXME: Does it make sense for value to be negative?
710   return Dis->tryAddingSymbolicOperand(MI, (uint32_t)Value, Address, isBranch,
711                                        /* Offset */ 0, InstSize);
712 }
713 
714 /// tryAddingPcLoadReferenceComment - trys to add a comment as to what is being
715 /// referenced by a load instruction with the base register that is the Pc.
716 /// These can often be values in a literal pool near the Address of the
717 /// instruction.  The Address of the instruction and its immediate Value are
718 /// used as a possible literal pool entry.  The SymbolLookUp call back will
719 /// return the name of a symbol referenced by the literal pool's entry if
720 /// the referenced address is that of a symbol.  Or it will return a pointer to
721 /// a literal 'C' string if the referenced address of the literal pool's entry
722 /// is an address into a section with 'C' string literals.
723 static void tryAddingPcLoadReferenceComment(uint64_t Address, int Value,
724                                             const void *Decoder) {
725   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
726   Dis->tryAddingPcLoadReferenceComment(Value, Address);
727 }
728 
729 // Thumb1 instructions don't have explicit S bits.  Rather, they
730 // implicitly set CPSR.  Since it's not represented in the encoding, the
731 // auto-generated decoder won't inject the CPSR operand.  We need to fix
732 // that as a post-pass.
733 static void AddThumb1SBit(MCInst &MI, bool InITBlock) {
734   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
735   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
736   MCInst::iterator I = MI.begin();
737   for (unsigned i = 0; i < NumOps; ++i, ++I) {
738     if (I == MI.end()) break;
739     if (OpInfo[i].isOptionalDef() && OpInfo[i].RegClass == ARM::CCRRegClassID) {
740       if (i > 0 && OpInfo[i-1].isPredicate()) continue;
741       MI.insert(I, MCOperand::createReg(InITBlock ? 0 : ARM::CPSR));
742       return;
743     }
744   }
745 
746   MI.insert(I, MCOperand::createReg(InITBlock ? 0 : ARM::CPSR));
747 }
748 
749 static bool isVectorPredicable(unsigned Opcode) {
750   const MCOperandInfo *OpInfo = ARMInsts[Opcode].OpInfo;
751   unsigned short NumOps = ARMInsts[Opcode].NumOperands;
752   for (unsigned i = 0; i < NumOps; ++i) {
753     if (ARM::isVpred(OpInfo[i].OperandType))
754       return true;
755   }
756   return false;
757 }
758 
759 // Most Thumb instructions don't have explicit predicates in the
760 // encoding, but rather get their predicates from IT context.  We need
761 // to fix up the predicate operands using this context information as a
762 // post-pass.
763 MCDisassembler::DecodeStatus
764 ARMDisassembler::AddThumbPredicate(MCInst &MI) const {
765   MCDisassembler::DecodeStatus S = Success;
766 
767   const FeatureBitset &FeatureBits = getSubtargetInfo().getFeatureBits();
768 
769   // A few instructions actually have predicates encoded in them.  Don't
770   // try to overwrite it if we're seeing one of those.
771   switch (MI.getOpcode()) {
772     case ARM::tBcc:
773     case ARM::t2Bcc:
774     case ARM::tCBZ:
775     case ARM::tCBNZ:
776     case ARM::tCPS:
777     case ARM::t2CPS3p:
778     case ARM::t2CPS2p:
779     case ARM::t2CPS1p:
780     case ARM::t2CSEL:
781     case ARM::t2CSINC:
782     case ARM::t2CSINV:
783     case ARM::t2CSNEG:
784     case ARM::tMOVSr:
785     case ARM::tSETEND:
786       // Some instructions (mostly conditional branches) are not
787       // allowed in IT blocks.
788       if (ITBlock.instrInITBlock())
789         S = SoftFail;
790       else
791         return Success;
792       break;
793     case ARM::t2HINT:
794       if (MI.getOperand(0).getImm() == 0x10 && (FeatureBits[ARM::FeatureRAS]) != 0)
795         S = SoftFail;
796       break;
797     case ARM::tB:
798     case ARM::t2B:
799     case ARM::t2TBB:
800     case ARM::t2TBH:
801       // Some instructions (mostly unconditional branches) can
802       // only appears at the end of, or outside of, an IT.
803       if (ITBlock.instrInITBlock() && !ITBlock.instrLastInITBlock())
804         S = SoftFail;
805       break;
806     default:
807       break;
808   }
809 
810   // Warn on non-VPT predicable instruction in a VPT block and a VPT
811   // predicable instruction in an IT block
812   if ((!isVectorPredicable(MI.getOpcode()) && VPTBlock.instrInVPTBlock()) ||
813        (isVectorPredicable(MI.getOpcode()) && ITBlock.instrInITBlock()))
814     S = SoftFail;
815 
816   // If we're in an IT/VPT block, base the predicate on that.  Otherwise,
817   // assume a predicate of AL.
818   unsigned CC = ARMCC::AL;
819   unsigned VCC = ARMVCC::None;
820   if (ITBlock.instrInITBlock()) {
821     CC = ITBlock.getITCC();
822     ITBlock.advanceITState();
823   } else if (VPTBlock.instrInVPTBlock()) {
824     VCC = VPTBlock.getVPTPred();
825     VPTBlock.advanceVPTState();
826   }
827 
828   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
829   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
830 
831   MCInst::iterator CCI = MI.begin();
832   for (unsigned i = 0; i < NumOps; ++i, ++CCI) {
833     if (OpInfo[i].isPredicate() || CCI == MI.end()) break;
834   }
835 
836   if (ARMInsts[MI.getOpcode()].isPredicable()) {
837     CCI = MI.insert(CCI, MCOperand::createImm(CC));
838     ++CCI;
839     if (CC == ARMCC::AL)
840       MI.insert(CCI, MCOperand::createReg(0));
841     else
842       MI.insert(CCI, MCOperand::createReg(ARM::CPSR));
843   } else if (CC != ARMCC::AL) {
844     Check(S, SoftFail);
845   }
846 
847   MCInst::iterator VCCI = MI.begin();
848   unsigned VCCPos;
849   for (VCCPos = 0; VCCPos < NumOps; ++VCCPos, ++VCCI) {
850     if (ARM::isVpred(OpInfo[VCCPos].OperandType) || VCCI == MI.end()) break;
851   }
852 
853   if (isVectorPredicable(MI.getOpcode())) {
854     VCCI = MI.insert(VCCI, MCOperand::createImm(VCC));
855     ++VCCI;
856     if (VCC == ARMVCC::None)
857       VCCI = MI.insert(VCCI, MCOperand::createReg(0));
858     else
859       VCCI = MI.insert(VCCI, MCOperand::createReg(ARM::P0));
860     ++VCCI;
861     VCCI = MI.insert(VCCI, MCOperand::createReg(0));
862     ++VCCI;
863     if (OpInfo[VCCPos].OperandType == ARM::OPERAND_VPRED_R) {
864       int TiedOp = ARMInsts[MI.getOpcode()].getOperandConstraint(
865         VCCPos + 3, MCOI::TIED_TO);
866       assert(TiedOp >= 0 &&
867              "Inactive register in vpred_r is not tied to an output!");
868       // Copy the operand to ensure it's not invalidated when MI grows.
869       MI.insert(VCCI, MCOperand(MI.getOperand(TiedOp)));
870     }
871   } else if (VCC != ARMVCC::None) {
872     Check(S, SoftFail);
873   }
874 
875   return S;
876 }
877 
878 // Thumb VFP instructions are a special case.  Because we share their
879 // encodings between ARM and Thumb modes, and they are predicable in ARM
880 // mode, the auto-generated decoder will give them an (incorrect)
881 // predicate operand.  We need to rewrite these operands based on the IT
882 // context as a post-pass.
883 void ARMDisassembler::UpdateThumbVFPPredicate(
884   DecodeStatus &S, MCInst &MI) const {
885   unsigned CC;
886   CC = ITBlock.getITCC();
887   if (CC == 0xF)
888     CC = ARMCC::AL;
889   if (ITBlock.instrInITBlock())
890     ITBlock.advanceITState();
891   else if (VPTBlock.instrInVPTBlock()) {
892     CC = VPTBlock.getVPTPred();
893     VPTBlock.advanceVPTState();
894   }
895 
896   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
897   MCInst::iterator I = MI.begin();
898   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
899   for (unsigned i = 0; i < NumOps; ++i, ++I) {
900     if (OpInfo[i].isPredicate() ) {
901       if (CC != ARMCC::AL && !ARMInsts[MI.getOpcode()].isPredicable())
902         Check(S, SoftFail);
903       I->setImm(CC);
904       ++I;
905       if (CC == ARMCC::AL)
906         I->setReg(0);
907       else
908         I->setReg(ARM::CPSR);
909       return;
910     }
911   }
912 }
913 
914 DecodeStatus ARMDisassembler::getThumbInstruction(MCInst &MI, uint64_t &Size,
915                                                   ArrayRef<uint8_t> Bytes,
916                                                   uint64_t Address,
917                                                   raw_ostream &CS) const {
918   CommentStream = &CS;
919 
920   assert(STI.getFeatureBits()[ARM::ModeThumb] &&
921          "Asked to disassemble in Thumb mode but Subtarget is in ARM mode!");
922 
923   // We want to read exactly 2 bytes of data.
924   if (Bytes.size() < 2) {
925     Size = 0;
926     return MCDisassembler::Fail;
927   }
928 
929   uint16_t Insn16 = (Bytes[1] << 8) | Bytes[0];
930   DecodeStatus Result =
931       decodeInstruction(DecoderTableThumb16, MI, Insn16, Address, this, STI);
932   if (Result != MCDisassembler::Fail) {
933     Size = 2;
934     Check(Result, AddThumbPredicate(MI));
935     return Result;
936   }
937 
938   Result = decodeInstruction(DecoderTableThumbSBit16, MI, Insn16, Address, this,
939                              STI);
940   if (Result) {
941     Size = 2;
942     bool InITBlock = ITBlock.instrInITBlock();
943     Check(Result, AddThumbPredicate(MI));
944     AddThumb1SBit(MI, InITBlock);
945     return Result;
946   }
947 
948   Result =
949       decodeInstruction(DecoderTableThumb216, MI, Insn16, Address, this, STI);
950   if (Result != MCDisassembler::Fail) {
951     Size = 2;
952 
953     // Nested IT blocks are UNPREDICTABLE.  Must be checked before we add
954     // the Thumb predicate.
955     if (MI.getOpcode() == ARM::t2IT && ITBlock.instrInITBlock())
956       Result = MCDisassembler::SoftFail;
957 
958     Check(Result, AddThumbPredicate(MI));
959 
960     // If we find an IT instruction, we need to parse its condition
961     // code and mask operands so that we can apply them correctly
962     // to the subsequent instructions.
963     if (MI.getOpcode() == ARM::t2IT) {
964       unsigned Firstcond = MI.getOperand(0).getImm();
965       unsigned Mask = MI.getOperand(1).getImm();
966       ITBlock.setITState(Firstcond, Mask);
967 
968       // An IT instruction that would give a 'NV' predicate is unpredictable.
969       if (Firstcond == ARMCC::AL && !isPowerOf2_32(Mask))
970         CS << "unpredictable IT predicate sequence";
971     }
972 
973     return Result;
974   }
975 
976   // We want to read exactly 4 bytes of data.
977   if (Bytes.size() < 4) {
978     Size = 0;
979     return MCDisassembler::Fail;
980   }
981 
982   uint32_t Insn32 =
983       (Bytes[3] << 8) | (Bytes[2] << 0) | (Bytes[1] << 24) | (Bytes[0] << 16);
984 
985   Result =
986       decodeInstruction(DecoderTableMVE32, MI, Insn32, Address, this, STI);
987   if (Result != MCDisassembler::Fail) {
988     Size = 4;
989 
990     // Nested VPT blocks are UNPREDICTABLE. Must be checked before we add
991     // the VPT predicate.
992     if (isVPTOpcode(MI.getOpcode()) && VPTBlock.instrInVPTBlock())
993       Result = MCDisassembler::SoftFail;
994 
995     Check(Result, AddThumbPredicate(MI));
996 
997     if (isVPTOpcode(MI.getOpcode())) {
998       unsigned Mask = MI.getOperand(0).getImm();
999       VPTBlock.setVPTState(Mask);
1000     }
1001 
1002     return Result;
1003   }
1004 
1005   Result =
1006       decodeInstruction(DecoderTableThumb32, MI, Insn32, Address, this, STI);
1007   if (Result != MCDisassembler::Fail) {
1008     Size = 4;
1009     bool InITBlock = ITBlock.instrInITBlock();
1010     Check(Result, AddThumbPredicate(MI));
1011     AddThumb1SBit(MI, InITBlock);
1012     return Result;
1013   }
1014 
1015   Result =
1016       decodeInstruction(DecoderTableThumb232, MI, Insn32, Address, this, STI);
1017   if (Result != MCDisassembler::Fail) {
1018     Size = 4;
1019     Check(Result, AddThumbPredicate(MI));
1020     return checkDecodedInstruction(MI, Size, Address, CS, Insn32, Result);
1021   }
1022 
1023   if (fieldFromInstruction(Insn32, 28, 4) == 0xE) {
1024     Result =
1025         decodeInstruction(DecoderTableVFP32, MI, Insn32, Address, this, STI);
1026     if (Result != MCDisassembler::Fail) {
1027       Size = 4;
1028       UpdateThumbVFPPredicate(Result, MI);
1029       return Result;
1030     }
1031   }
1032 
1033   Result =
1034       decodeInstruction(DecoderTableVFPV832, MI, Insn32, Address, this, STI);
1035   if (Result != MCDisassembler::Fail) {
1036     Size = 4;
1037     return Result;
1038   }
1039 
1040   if (fieldFromInstruction(Insn32, 28, 4) == 0xE) {
1041     Result = decodeInstruction(DecoderTableNEONDup32, MI, Insn32, Address, this,
1042                                STI);
1043     if (Result != MCDisassembler::Fail) {
1044       Size = 4;
1045       Check(Result, AddThumbPredicate(MI));
1046       return Result;
1047     }
1048   }
1049 
1050   if (fieldFromInstruction(Insn32, 24, 8) == 0xF9) {
1051     uint32_t NEONLdStInsn = Insn32;
1052     NEONLdStInsn &= 0xF0FFFFFF;
1053     NEONLdStInsn |= 0x04000000;
1054     Result = decodeInstruction(DecoderTableNEONLoadStore32, MI, NEONLdStInsn,
1055                                Address, this, STI);
1056     if (Result != MCDisassembler::Fail) {
1057       Size = 4;
1058       Check(Result, AddThumbPredicate(MI));
1059       return Result;
1060     }
1061   }
1062 
1063   if (fieldFromInstruction(Insn32, 24, 4) == 0xF) {
1064     uint32_t NEONDataInsn = Insn32;
1065     NEONDataInsn &= 0xF0FFFFFF; // Clear bits 27-24
1066     NEONDataInsn |= (NEONDataInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
1067     NEONDataInsn |= 0x12000000; // Set bits 28 and 25
1068     Result = decodeInstruction(DecoderTableNEONData32, MI, NEONDataInsn,
1069                                Address, this, STI);
1070     if (Result != MCDisassembler::Fail) {
1071       Size = 4;
1072       Check(Result, AddThumbPredicate(MI));
1073       return Result;
1074     }
1075 
1076     uint32_t NEONCryptoInsn = Insn32;
1077     NEONCryptoInsn &= 0xF0FFFFFF; // Clear bits 27-24
1078     NEONCryptoInsn |= (NEONCryptoInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
1079     NEONCryptoInsn |= 0x12000000; // Set bits 28 and 25
1080     Result = decodeInstruction(DecoderTablev8Crypto32, MI, NEONCryptoInsn,
1081                                Address, this, STI);
1082     if (Result != MCDisassembler::Fail) {
1083       Size = 4;
1084       return Result;
1085     }
1086 
1087     uint32_t NEONv8Insn = Insn32;
1088     NEONv8Insn &= 0xF3FFFFFF; // Clear bits 27-26
1089     Result = decodeInstruction(DecoderTablev8NEON32, MI, NEONv8Insn, Address,
1090                                this, STI);
1091     if (Result != MCDisassembler::Fail) {
1092       Size = 4;
1093       return Result;
1094     }
1095   }
1096 
1097   uint32_t Coproc = fieldFromInstruction(Insn32, 8, 4);
1098   const uint8_t *DecoderTable = ARM::isCDECoproc(Coproc, STI)
1099                                     ? DecoderTableThumb2CDE32
1100                                     : DecoderTableThumb2CoProc32;
1101   Result =
1102       decodeInstruction(DecoderTable, MI, Insn32, Address, this, STI);
1103   if (Result != MCDisassembler::Fail) {
1104     Size = 4;
1105     Check(Result, AddThumbPredicate(MI));
1106     return Result;
1107   }
1108 
1109   Size = 0;
1110   return MCDisassembler::Fail;
1111 }
1112 
1113 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeARMDisassembler() {
1114   TargetRegistry::RegisterMCDisassembler(getTheARMLETarget(),
1115                                          createARMDisassembler);
1116   TargetRegistry::RegisterMCDisassembler(getTheARMBETarget(),
1117                                          createARMDisassembler);
1118   TargetRegistry::RegisterMCDisassembler(getTheThumbLETarget(),
1119                                          createARMDisassembler);
1120   TargetRegistry::RegisterMCDisassembler(getTheThumbBETarget(),
1121                                          createARMDisassembler);
1122 }
1123 
1124 static const uint16_t GPRDecoderTable[] = {
1125   ARM::R0, ARM::R1, ARM::R2, ARM::R3,
1126   ARM::R4, ARM::R5, ARM::R6, ARM::R7,
1127   ARM::R8, ARM::R9, ARM::R10, ARM::R11,
1128   ARM::R12, ARM::SP, ARM::LR, ARM::PC
1129 };
1130 
1131 static const uint16_t CLRMGPRDecoderTable[] = {
1132   ARM::R0, ARM::R1, ARM::R2, ARM::R3,
1133   ARM::R4, ARM::R5, ARM::R6, ARM::R7,
1134   ARM::R8, ARM::R9, ARM::R10, ARM::R11,
1135   ARM::R12, 0, ARM::LR, ARM::APSR
1136 };
1137 
1138 static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1139                                    uint64_t Address, const void *Decoder) {
1140   if (RegNo > 15)
1141     return MCDisassembler::Fail;
1142 
1143   unsigned Register = GPRDecoderTable[RegNo];
1144   Inst.addOperand(MCOperand::createReg(Register));
1145   return MCDisassembler::Success;
1146 }
1147 
1148 static DecodeStatus DecodeCLRMGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1149                                                uint64_t Address,
1150                                                const void *Decoder) {
1151   if (RegNo > 15)
1152     return MCDisassembler::Fail;
1153 
1154   unsigned Register = CLRMGPRDecoderTable[RegNo];
1155   if (Register == 0)
1156     return MCDisassembler::Fail;
1157 
1158   Inst.addOperand(MCOperand::createReg(Register));
1159   return MCDisassembler::Success;
1160 }
1161 
1162 static DecodeStatus
1163 DecodeGPRnopcRegisterClass(MCInst &Inst, unsigned RegNo,
1164                            uint64_t Address, const void *Decoder) {
1165   DecodeStatus S = MCDisassembler::Success;
1166 
1167   if (RegNo == 15)
1168     S = MCDisassembler::SoftFail;
1169 
1170   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1171 
1172   return S;
1173 }
1174 
1175 static DecodeStatus
1176 DecodeGPRwithAPSRRegisterClass(MCInst &Inst, unsigned RegNo,
1177                                uint64_t Address, const void *Decoder) {
1178   DecodeStatus S = MCDisassembler::Success;
1179 
1180   if (RegNo == 15)
1181   {
1182     Inst.addOperand(MCOperand::createReg(ARM::APSR_NZCV));
1183     return MCDisassembler::Success;
1184   }
1185 
1186   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1187   return S;
1188 }
1189 
1190 static DecodeStatus
1191 DecodeGPRwithZRRegisterClass(MCInst &Inst, unsigned RegNo,
1192                              uint64_t Address, const void *Decoder) {
1193   DecodeStatus S = MCDisassembler::Success;
1194 
1195   if (RegNo == 15)
1196   {
1197     Inst.addOperand(MCOperand::createReg(ARM::ZR));
1198     return MCDisassembler::Success;
1199   }
1200 
1201   if (RegNo == 13)
1202     Check(S, MCDisassembler::SoftFail);
1203 
1204   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1205   return S;
1206 }
1207 
1208 static DecodeStatus
1209 DecodeGPRwithZRnospRegisterClass(MCInst &Inst, unsigned RegNo,
1210                                  uint64_t Address, const void *Decoder) {
1211   DecodeStatus S = MCDisassembler::Success;
1212   if (RegNo == 13)
1213     return MCDisassembler::Fail;
1214   Check(S, DecodeGPRwithZRRegisterClass(Inst, RegNo, Address, Decoder));
1215   return S;
1216 }
1217 
1218 static DecodeStatus DecodetGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1219                                    uint64_t Address, const void *Decoder) {
1220   if (RegNo > 7)
1221     return MCDisassembler::Fail;
1222   return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
1223 }
1224 
1225 static const uint16_t GPRPairDecoderTable[] = {
1226   ARM::R0_R1, ARM::R2_R3,   ARM::R4_R5,  ARM::R6_R7,
1227   ARM::R8_R9, ARM::R10_R11, ARM::R12_SP
1228 };
1229 
1230 static DecodeStatus DecodeGPRPairRegisterClass(MCInst &Inst, unsigned RegNo,
1231                                    uint64_t Address, const void *Decoder) {
1232   DecodeStatus S = MCDisassembler::Success;
1233 
1234   // According to the Arm ARM RegNo = 14 is undefined, but we return fail
1235   // rather than SoftFail as there is no GPRPair table entry for index 7.
1236   if (RegNo > 13)
1237     return MCDisassembler::Fail;
1238 
1239   if (RegNo & 1)
1240      S = MCDisassembler::SoftFail;
1241 
1242   unsigned RegisterPair = GPRPairDecoderTable[RegNo/2];
1243   Inst.addOperand(MCOperand::createReg(RegisterPair));
1244   return S;
1245 }
1246 
1247 static DecodeStatus DecodeGPRPairnospRegisterClass(MCInst &Inst, unsigned RegNo,
1248                                    uint64_t Address, const void *Decoder) {
1249   if (RegNo > 13)
1250     return MCDisassembler::Fail;
1251 
1252   unsigned RegisterPair = GPRPairDecoderTable[RegNo/2];
1253   Inst.addOperand(MCOperand::createReg(RegisterPair));
1254 
1255   if ((RegNo & 1) || RegNo > 10)
1256      return MCDisassembler::SoftFail;
1257   return MCDisassembler::Success;
1258 }
1259 
1260 static DecodeStatus DecodeGPRspRegisterClass(MCInst &Inst, unsigned RegNo,
1261                                              uint64_t Address,
1262                                              const void *Decoder) {
1263   if (RegNo != 13)
1264     return MCDisassembler::Fail;
1265 
1266   unsigned Register = GPRDecoderTable[RegNo];
1267   Inst.addOperand(MCOperand::createReg(Register));
1268   return MCDisassembler::Success;
1269 }
1270 
1271 static DecodeStatus DecodetcGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1272                                    uint64_t Address, const void *Decoder) {
1273   unsigned Register = 0;
1274   switch (RegNo) {
1275     case 0:
1276       Register = ARM::R0;
1277       break;
1278     case 1:
1279       Register = ARM::R1;
1280       break;
1281     case 2:
1282       Register = ARM::R2;
1283       break;
1284     case 3:
1285       Register = ARM::R3;
1286       break;
1287     case 9:
1288       Register = ARM::R9;
1289       break;
1290     case 12:
1291       Register = ARM::R12;
1292       break;
1293     default:
1294       return MCDisassembler::Fail;
1295     }
1296 
1297   Inst.addOperand(MCOperand::createReg(Register));
1298   return MCDisassembler::Success;
1299 }
1300 
1301 static DecodeStatus DecoderGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1302                                    uint64_t Address, const void *Decoder) {
1303   DecodeStatus S = MCDisassembler::Success;
1304 
1305   const FeatureBitset &featureBits =
1306     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1307 
1308   if ((RegNo == 13 && !featureBits[ARM::HasV8Ops]) || RegNo == 15)
1309     S = MCDisassembler::SoftFail;
1310 
1311   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1312   return S;
1313 }
1314 
1315 static const uint16_t SPRDecoderTable[] = {
1316      ARM::S0,  ARM::S1,  ARM::S2,  ARM::S3,
1317      ARM::S4,  ARM::S5,  ARM::S6,  ARM::S7,
1318      ARM::S8,  ARM::S9, ARM::S10, ARM::S11,
1319     ARM::S12, ARM::S13, ARM::S14, ARM::S15,
1320     ARM::S16, ARM::S17, ARM::S18, ARM::S19,
1321     ARM::S20, ARM::S21, ARM::S22, ARM::S23,
1322     ARM::S24, ARM::S25, ARM::S26, ARM::S27,
1323     ARM::S28, ARM::S29, ARM::S30, ARM::S31
1324 };
1325 
1326 static DecodeStatus DecodeSPRRegisterClass(MCInst &Inst, unsigned RegNo,
1327                                    uint64_t Address, const void *Decoder) {
1328   if (RegNo > 31)
1329     return MCDisassembler::Fail;
1330 
1331   unsigned Register = SPRDecoderTable[RegNo];
1332   Inst.addOperand(MCOperand::createReg(Register));
1333   return MCDisassembler::Success;
1334 }
1335 
1336 static DecodeStatus DecodeHPRRegisterClass(MCInst &Inst, unsigned RegNo,
1337                                    uint64_t Address, const void *Decoder) {
1338   return DecodeSPRRegisterClass(Inst, RegNo, Address, Decoder);
1339 }
1340 
1341 static const uint16_t DPRDecoderTable[] = {
1342      ARM::D0,  ARM::D1,  ARM::D2,  ARM::D3,
1343      ARM::D4,  ARM::D5,  ARM::D6,  ARM::D7,
1344      ARM::D8,  ARM::D9, ARM::D10, ARM::D11,
1345     ARM::D12, ARM::D13, ARM::D14, ARM::D15,
1346     ARM::D16, ARM::D17, ARM::D18, ARM::D19,
1347     ARM::D20, ARM::D21, ARM::D22, ARM::D23,
1348     ARM::D24, ARM::D25, ARM::D26, ARM::D27,
1349     ARM::D28, ARM::D29, ARM::D30, ARM::D31
1350 };
1351 
1352 static DecodeStatus DecodeDPRRegisterClass(MCInst &Inst, unsigned RegNo,
1353                                    uint64_t Address, const void *Decoder) {
1354   const FeatureBitset &featureBits =
1355     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1356 
1357   bool hasD32 = featureBits[ARM::FeatureD32];
1358 
1359   if (RegNo > 31 || (!hasD32 && RegNo > 15))
1360     return MCDisassembler::Fail;
1361 
1362   unsigned Register = DPRDecoderTable[RegNo];
1363   Inst.addOperand(MCOperand::createReg(Register));
1364   return MCDisassembler::Success;
1365 }
1366 
1367 static DecodeStatus DecodeDPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
1368                                    uint64_t Address, const void *Decoder) {
1369   if (RegNo > 7)
1370     return MCDisassembler::Fail;
1371   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
1372 }
1373 
1374 static DecodeStatus DecodeSPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
1375                                    uint64_t Address, const void *Decoder) {
1376   if (RegNo > 15)
1377     return MCDisassembler::Fail;
1378   return DecodeSPRRegisterClass(Inst, RegNo, Address, Decoder);
1379 }
1380 
1381 static DecodeStatus
1382 DecodeDPR_VFP2RegisterClass(MCInst &Inst, unsigned RegNo,
1383                             uint64_t Address, const void *Decoder) {
1384   if (RegNo > 15)
1385     return MCDisassembler::Fail;
1386   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
1387 }
1388 
1389 static const uint16_t QPRDecoderTable[] = {
1390      ARM::Q0,  ARM::Q1,  ARM::Q2,  ARM::Q3,
1391      ARM::Q4,  ARM::Q5,  ARM::Q6,  ARM::Q7,
1392      ARM::Q8,  ARM::Q9, ARM::Q10, ARM::Q11,
1393     ARM::Q12, ARM::Q13, ARM::Q14, ARM::Q15
1394 };
1395 
1396 static DecodeStatus DecodeQPRRegisterClass(MCInst &Inst, unsigned RegNo,
1397                                    uint64_t Address, const void *Decoder) {
1398   if (RegNo > 31 || (RegNo & 1) != 0)
1399     return MCDisassembler::Fail;
1400   RegNo >>= 1;
1401 
1402   unsigned Register = QPRDecoderTable[RegNo];
1403   Inst.addOperand(MCOperand::createReg(Register));
1404   return MCDisassembler::Success;
1405 }
1406 
1407 static const uint16_t DPairDecoderTable[] = {
1408   ARM::Q0,  ARM::D1_D2,   ARM::Q1,  ARM::D3_D4,   ARM::Q2,  ARM::D5_D6,
1409   ARM::Q3,  ARM::D7_D8,   ARM::Q4,  ARM::D9_D10,  ARM::Q5,  ARM::D11_D12,
1410   ARM::Q6,  ARM::D13_D14, ARM::Q7,  ARM::D15_D16, ARM::Q8,  ARM::D17_D18,
1411   ARM::Q9,  ARM::D19_D20, ARM::Q10, ARM::D21_D22, ARM::Q11, ARM::D23_D24,
1412   ARM::Q12, ARM::D25_D26, ARM::Q13, ARM::D27_D28, ARM::Q14, ARM::D29_D30,
1413   ARM::Q15
1414 };
1415 
1416 static DecodeStatus DecodeDPairRegisterClass(MCInst &Inst, unsigned RegNo,
1417                                    uint64_t Address, const void *Decoder) {
1418   if (RegNo > 30)
1419     return MCDisassembler::Fail;
1420 
1421   unsigned Register = DPairDecoderTable[RegNo];
1422   Inst.addOperand(MCOperand::createReg(Register));
1423   return MCDisassembler::Success;
1424 }
1425 
1426 static const uint16_t DPairSpacedDecoderTable[] = {
1427   ARM::D0_D2,   ARM::D1_D3,   ARM::D2_D4,   ARM::D3_D5,
1428   ARM::D4_D6,   ARM::D5_D7,   ARM::D6_D8,   ARM::D7_D9,
1429   ARM::D8_D10,  ARM::D9_D11,  ARM::D10_D12, ARM::D11_D13,
1430   ARM::D12_D14, ARM::D13_D15, ARM::D14_D16, ARM::D15_D17,
1431   ARM::D16_D18, ARM::D17_D19, ARM::D18_D20, ARM::D19_D21,
1432   ARM::D20_D22, ARM::D21_D23, ARM::D22_D24, ARM::D23_D25,
1433   ARM::D24_D26, ARM::D25_D27, ARM::D26_D28, ARM::D27_D29,
1434   ARM::D28_D30, ARM::D29_D31
1435 };
1436 
1437 static DecodeStatus DecodeDPairSpacedRegisterClass(MCInst &Inst,
1438                                                    unsigned RegNo,
1439                                                    uint64_t Address,
1440                                                    const void *Decoder) {
1441   if (RegNo > 29)
1442     return MCDisassembler::Fail;
1443 
1444   unsigned Register = DPairSpacedDecoderTable[RegNo];
1445   Inst.addOperand(MCOperand::createReg(Register));
1446   return MCDisassembler::Success;
1447 }
1448 
1449 static DecodeStatus DecodePredicateOperand(MCInst &Inst, unsigned Val,
1450                                uint64_t Address, const void *Decoder) {
1451   DecodeStatus S = MCDisassembler::Success;
1452   if (Val == 0xF) return MCDisassembler::Fail;
1453   // AL predicate is not allowed on Thumb1 branches.
1454   if (Inst.getOpcode() == ARM::tBcc && Val == 0xE)
1455     return MCDisassembler::Fail;
1456   if (Val != ARMCC::AL && !ARMInsts[Inst.getOpcode()].isPredicable())
1457     Check(S, MCDisassembler::SoftFail);
1458   Inst.addOperand(MCOperand::createImm(Val));
1459   if (Val == ARMCC::AL) {
1460     Inst.addOperand(MCOperand::createReg(0));
1461   } else
1462     Inst.addOperand(MCOperand::createReg(ARM::CPSR));
1463   return S;
1464 }
1465 
1466 static DecodeStatus DecodeCCOutOperand(MCInst &Inst, unsigned Val,
1467                                uint64_t Address, const void *Decoder) {
1468   if (Val)
1469     Inst.addOperand(MCOperand::createReg(ARM::CPSR));
1470   else
1471     Inst.addOperand(MCOperand::createReg(0));
1472   return MCDisassembler::Success;
1473 }
1474 
1475 static DecodeStatus DecodeSORegImmOperand(MCInst &Inst, unsigned Val,
1476                                uint64_t Address, const void *Decoder) {
1477   DecodeStatus S = MCDisassembler::Success;
1478 
1479   unsigned Rm = fieldFromInstruction(Val, 0, 4);
1480   unsigned type = fieldFromInstruction(Val, 5, 2);
1481   unsigned imm = fieldFromInstruction(Val, 7, 5);
1482 
1483   // Register-immediate
1484   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
1485     return MCDisassembler::Fail;
1486 
1487   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1488   switch (type) {
1489     case 0:
1490       Shift = ARM_AM::lsl;
1491       break;
1492     case 1:
1493       Shift = ARM_AM::lsr;
1494       break;
1495     case 2:
1496       Shift = ARM_AM::asr;
1497       break;
1498     case 3:
1499       Shift = ARM_AM::ror;
1500       break;
1501   }
1502 
1503   if (Shift == ARM_AM::ror && imm == 0)
1504     Shift = ARM_AM::rrx;
1505 
1506   unsigned Op = Shift | (imm << 3);
1507   Inst.addOperand(MCOperand::createImm(Op));
1508 
1509   return S;
1510 }
1511 
1512 static DecodeStatus DecodeSORegRegOperand(MCInst &Inst, unsigned Val,
1513                                uint64_t Address, const void *Decoder) {
1514   DecodeStatus S = MCDisassembler::Success;
1515 
1516   unsigned Rm = fieldFromInstruction(Val, 0, 4);
1517   unsigned type = fieldFromInstruction(Val, 5, 2);
1518   unsigned Rs = fieldFromInstruction(Val, 8, 4);
1519 
1520   // Register-register
1521   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1522     return MCDisassembler::Fail;
1523   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rs, Address, Decoder)))
1524     return MCDisassembler::Fail;
1525 
1526   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1527   switch (type) {
1528     case 0:
1529       Shift = ARM_AM::lsl;
1530       break;
1531     case 1:
1532       Shift = ARM_AM::lsr;
1533       break;
1534     case 2:
1535       Shift = ARM_AM::asr;
1536       break;
1537     case 3:
1538       Shift = ARM_AM::ror;
1539       break;
1540   }
1541 
1542   Inst.addOperand(MCOperand::createImm(Shift));
1543 
1544   return S;
1545 }
1546 
1547 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Val,
1548                                  uint64_t Address, const void *Decoder) {
1549   DecodeStatus S = MCDisassembler::Success;
1550 
1551   bool NeedDisjointWriteback = false;
1552   unsigned WritebackReg = 0;
1553   bool CLRM = false;
1554   switch (Inst.getOpcode()) {
1555   default:
1556     break;
1557   case ARM::LDMIA_UPD:
1558   case ARM::LDMDB_UPD:
1559   case ARM::LDMIB_UPD:
1560   case ARM::LDMDA_UPD:
1561   case ARM::t2LDMIA_UPD:
1562   case ARM::t2LDMDB_UPD:
1563   case ARM::t2STMIA_UPD:
1564   case ARM::t2STMDB_UPD:
1565     NeedDisjointWriteback = true;
1566     WritebackReg = Inst.getOperand(0).getReg();
1567     break;
1568   case ARM::t2CLRM:
1569     CLRM = true;
1570     break;
1571   }
1572 
1573   // Empty register lists are not allowed.
1574   if (Val == 0) return MCDisassembler::Fail;
1575   for (unsigned i = 0; i < 16; ++i) {
1576     if (Val & (1 << i)) {
1577       if (CLRM) {
1578         if (!Check(S, DecodeCLRMGPRRegisterClass(Inst, i, Address, Decoder))) {
1579           return MCDisassembler::Fail;
1580         }
1581       } else {
1582         if (!Check(S, DecodeGPRRegisterClass(Inst, i, Address, Decoder)))
1583           return MCDisassembler::Fail;
1584         // Writeback not allowed if Rn is in the target list.
1585         if (NeedDisjointWriteback && WritebackReg == Inst.end()[-1].getReg())
1586           Check(S, MCDisassembler::SoftFail);
1587       }
1588     }
1589   }
1590 
1591   return S;
1592 }
1593 
1594 static DecodeStatus DecodeSPRRegListOperand(MCInst &Inst, unsigned Val,
1595                                  uint64_t Address, const void *Decoder) {
1596   DecodeStatus S = MCDisassembler::Success;
1597 
1598   unsigned Vd = fieldFromInstruction(Val, 8, 5);
1599   unsigned regs = fieldFromInstruction(Val, 0, 8);
1600 
1601   // In case of unpredictable encoding, tweak the operands.
1602   if (regs == 0 || (Vd + regs) > 32) {
1603     regs = Vd + regs > 32 ? 32 - Vd : regs;
1604     regs = std::max( 1u, regs);
1605     S = MCDisassembler::SoftFail;
1606   }
1607 
1608   if (!Check(S, DecodeSPRRegisterClass(Inst, Vd, Address, Decoder)))
1609     return MCDisassembler::Fail;
1610   for (unsigned i = 0; i < (regs - 1); ++i) {
1611     if (!Check(S, DecodeSPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1612       return MCDisassembler::Fail;
1613   }
1614 
1615   return S;
1616 }
1617 
1618 static DecodeStatus DecodeDPRRegListOperand(MCInst &Inst, unsigned Val,
1619                                  uint64_t Address, const void *Decoder) {
1620   DecodeStatus S = MCDisassembler::Success;
1621 
1622   unsigned Vd = fieldFromInstruction(Val, 8, 5);
1623   unsigned regs = fieldFromInstruction(Val, 1, 7);
1624 
1625   // In case of unpredictable encoding, tweak the operands.
1626   if (regs == 0 || regs > 16 || (Vd + regs) > 32) {
1627     regs = Vd + regs > 32 ? 32 - Vd : regs;
1628     regs = std::max( 1u, regs);
1629     regs = std::min(16u, regs);
1630     S = MCDisassembler::SoftFail;
1631   }
1632 
1633   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
1634       return MCDisassembler::Fail;
1635   for (unsigned i = 0; i < (regs - 1); ++i) {
1636     if (!Check(S, DecodeDPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1637       return MCDisassembler::Fail;
1638   }
1639 
1640   return S;
1641 }
1642 
1643 static DecodeStatus DecodeBitfieldMaskOperand(MCInst &Inst, unsigned Val,
1644                                       uint64_t Address, const void *Decoder) {
1645   // This operand encodes a mask of contiguous zeros between a specified MSB
1646   // and LSB.  To decode it, we create the mask of all bits MSB-and-lower,
1647   // the mask of all bits LSB-and-lower, and then xor them to create
1648   // the mask of that's all ones on [msb, lsb].  Finally we not it to
1649   // create the final mask.
1650   unsigned msb = fieldFromInstruction(Val, 5, 5);
1651   unsigned lsb = fieldFromInstruction(Val, 0, 5);
1652 
1653   DecodeStatus S = MCDisassembler::Success;
1654   if (lsb > msb) {
1655     Check(S, MCDisassembler::SoftFail);
1656     // The check above will cause the warning for the "potentially undefined
1657     // instruction encoding" but we can't build a bad MCOperand value here
1658     // with a lsb > msb or else printing the MCInst will cause a crash.
1659     lsb = msb;
1660   }
1661 
1662   uint32_t msb_mask = 0xFFFFFFFF;
1663   if (msb != 31) msb_mask = (1U << (msb+1)) - 1;
1664   uint32_t lsb_mask = (1U << lsb) - 1;
1665 
1666   Inst.addOperand(MCOperand::createImm(~(msb_mask ^ lsb_mask)));
1667   return S;
1668 }
1669 
1670 static DecodeStatus DecodeCopMemInstruction(MCInst &Inst, unsigned Insn,
1671                                   uint64_t Address, const void *Decoder) {
1672   DecodeStatus S = MCDisassembler::Success;
1673 
1674   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1675   unsigned CRd = fieldFromInstruction(Insn, 12, 4);
1676   unsigned coproc = fieldFromInstruction(Insn, 8, 4);
1677   unsigned imm = fieldFromInstruction(Insn, 0, 8);
1678   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1679   unsigned U = fieldFromInstruction(Insn, 23, 1);
1680   const FeatureBitset &featureBits =
1681     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1682 
1683   switch (Inst.getOpcode()) {
1684     case ARM::LDC_OFFSET:
1685     case ARM::LDC_PRE:
1686     case ARM::LDC_POST:
1687     case ARM::LDC_OPTION:
1688     case ARM::LDCL_OFFSET:
1689     case ARM::LDCL_PRE:
1690     case ARM::LDCL_POST:
1691     case ARM::LDCL_OPTION:
1692     case ARM::STC_OFFSET:
1693     case ARM::STC_PRE:
1694     case ARM::STC_POST:
1695     case ARM::STC_OPTION:
1696     case ARM::STCL_OFFSET:
1697     case ARM::STCL_PRE:
1698     case ARM::STCL_POST:
1699     case ARM::STCL_OPTION:
1700     case ARM::t2LDC_OFFSET:
1701     case ARM::t2LDC_PRE:
1702     case ARM::t2LDC_POST:
1703     case ARM::t2LDC_OPTION:
1704     case ARM::t2LDCL_OFFSET:
1705     case ARM::t2LDCL_PRE:
1706     case ARM::t2LDCL_POST:
1707     case ARM::t2LDCL_OPTION:
1708     case ARM::t2STC_OFFSET:
1709     case ARM::t2STC_PRE:
1710     case ARM::t2STC_POST:
1711     case ARM::t2STC_OPTION:
1712     case ARM::t2STCL_OFFSET:
1713     case ARM::t2STCL_PRE:
1714     case ARM::t2STCL_POST:
1715     case ARM::t2STCL_OPTION:
1716     case ARM::t2LDC2_OFFSET:
1717     case ARM::t2LDC2L_OFFSET:
1718     case ARM::t2LDC2_PRE:
1719     case ARM::t2LDC2L_PRE:
1720     case ARM::t2STC2_OFFSET:
1721     case ARM::t2STC2L_OFFSET:
1722     case ARM::t2STC2_PRE:
1723     case ARM::t2STC2L_PRE:
1724     case ARM::LDC2_OFFSET:
1725     case ARM::LDC2L_OFFSET:
1726     case ARM::LDC2_PRE:
1727     case ARM::LDC2L_PRE:
1728     case ARM::STC2_OFFSET:
1729     case ARM::STC2L_OFFSET:
1730     case ARM::STC2_PRE:
1731     case ARM::STC2L_PRE:
1732     case ARM::t2LDC2_OPTION:
1733     case ARM::t2STC2_OPTION:
1734     case ARM::t2LDC2_POST:
1735     case ARM::t2LDC2L_POST:
1736     case ARM::t2STC2_POST:
1737     case ARM::t2STC2L_POST:
1738     case ARM::LDC2_POST:
1739     case ARM::LDC2L_POST:
1740     case ARM::STC2_POST:
1741     case ARM::STC2L_POST:
1742       if (coproc == 0xA || coproc == 0xB ||
1743           (featureBits[ARM::HasV8_1MMainlineOps] &&
1744            (coproc == 0x8 || coproc == 0x9 || coproc == 0xA || coproc == 0xB ||
1745             coproc == 0xE || coproc == 0xF)))
1746         return MCDisassembler::Fail;
1747       break;
1748     default:
1749       break;
1750   }
1751 
1752   if (featureBits[ARM::HasV8Ops] && (coproc != 14))
1753     return MCDisassembler::Fail;
1754 
1755   Inst.addOperand(MCOperand::createImm(coproc));
1756   Inst.addOperand(MCOperand::createImm(CRd));
1757   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1758     return MCDisassembler::Fail;
1759 
1760   switch (Inst.getOpcode()) {
1761     case ARM::t2LDC2_OFFSET:
1762     case ARM::t2LDC2L_OFFSET:
1763     case ARM::t2LDC2_PRE:
1764     case ARM::t2LDC2L_PRE:
1765     case ARM::t2STC2_OFFSET:
1766     case ARM::t2STC2L_OFFSET:
1767     case ARM::t2STC2_PRE:
1768     case ARM::t2STC2L_PRE:
1769     case ARM::LDC2_OFFSET:
1770     case ARM::LDC2L_OFFSET:
1771     case ARM::LDC2_PRE:
1772     case ARM::LDC2L_PRE:
1773     case ARM::STC2_OFFSET:
1774     case ARM::STC2L_OFFSET:
1775     case ARM::STC2_PRE:
1776     case ARM::STC2L_PRE:
1777     case ARM::t2LDC_OFFSET:
1778     case ARM::t2LDCL_OFFSET:
1779     case ARM::t2LDC_PRE:
1780     case ARM::t2LDCL_PRE:
1781     case ARM::t2STC_OFFSET:
1782     case ARM::t2STCL_OFFSET:
1783     case ARM::t2STC_PRE:
1784     case ARM::t2STCL_PRE:
1785     case ARM::LDC_OFFSET:
1786     case ARM::LDCL_OFFSET:
1787     case ARM::LDC_PRE:
1788     case ARM::LDCL_PRE:
1789     case ARM::STC_OFFSET:
1790     case ARM::STCL_OFFSET:
1791     case ARM::STC_PRE:
1792     case ARM::STCL_PRE:
1793       imm = ARM_AM::getAM5Opc(U ? ARM_AM::add : ARM_AM::sub, imm);
1794       Inst.addOperand(MCOperand::createImm(imm));
1795       break;
1796     case ARM::t2LDC2_POST:
1797     case ARM::t2LDC2L_POST:
1798     case ARM::t2STC2_POST:
1799     case ARM::t2STC2L_POST:
1800     case ARM::LDC2_POST:
1801     case ARM::LDC2L_POST:
1802     case ARM::STC2_POST:
1803     case ARM::STC2L_POST:
1804     case ARM::t2LDC_POST:
1805     case ARM::t2LDCL_POST:
1806     case ARM::t2STC_POST:
1807     case ARM::t2STCL_POST:
1808     case ARM::LDC_POST:
1809     case ARM::LDCL_POST:
1810     case ARM::STC_POST:
1811     case ARM::STCL_POST:
1812       imm |= U << 8;
1813       LLVM_FALLTHROUGH;
1814     default:
1815       // The 'option' variant doesn't encode 'U' in the immediate since
1816       // the immediate is unsigned [0,255].
1817       Inst.addOperand(MCOperand::createImm(imm));
1818       break;
1819   }
1820 
1821   switch (Inst.getOpcode()) {
1822     case ARM::LDC_OFFSET:
1823     case ARM::LDC_PRE:
1824     case ARM::LDC_POST:
1825     case ARM::LDC_OPTION:
1826     case ARM::LDCL_OFFSET:
1827     case ARM::LDCL_PRE:
1828     case ARM::LDCL_POST:
1829     case ARM::LDCL_OPTION:
1830     case ARM::STC_OFFSET:
1831     case ARM::STC_PRE:
1832     case ARM::STC_POST:
1833     case ARM::STC_OPTION:
1834     case ARM::STCL_OFFSET:
1835     case ARM::STCL_PRE:
1836     case ARM::STCL_POST:
1837     case ARM::STCL_OPTION:
1838       if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1839         return MCDisassembler::Fail;
1840       break;
1841     default:
1842       break;
1843   }
1844 
1845   return S;
1846 }
1847 
1848 static DecodeStatus
1849 DecodeAddrMode2IdxInstruction(MCInst &Inst, unsigned Insn,
1850                               uint64_t Address, const void *Decoder) {
1851   DecodeStatus S = MCDisassembler::Success;
1852 
1853   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1854   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
1855   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
1856   unsigned imm = fieldFromInstruction(Insn, 0, 12);
1857   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1858   unsigned reg = fieldFromInstruction(Insn, 25, 1);
1859   unsigned P = fieldFromInstruction(Insn, 24, 1);
1860   unsigned W = fieldFromInstruction(Insn, 21, 1);
1861 
1862   // On stores, the writeback operand precedes Rt.
1863   switch (Inst.getOpcode()) {
1864     case ARM::STR_POST_IMM:
1865     case ARM::STR_POST_REG:
1866     case ARM::STRB_POST_IMM:
1867     case ARM::STRB_POST_REG:
1868     case ARM::STRT_POST_REG:
1869     case ARM::STRT_POST_IMM:
1870     case ARM::STRBT_POST_REG:
1871     case ARM::STRBT_POST_IMM:
1872       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1873         return MCDisassembler::Fail;
1874       break;
1875     default:
1876       break;
1877   }
1878 
1879   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
1880     return MCDisassembler::Fail;
1881 
1882   // On loads, the writeback operand comes after Rt.
1883   switch (Inst.getOpcode()) {
1884     case ARM::LDR_POST_IMM:
1885     case ARM::LDR_POST_REG:
1886     case ARM::LDRB_POST_IMM:
1887     case ARM::LDRB_POST_REG:
1888     case ARM::LDRBT_POST_REG:
1889     case ARM::LDRBT_POST_IMM:
1890     case ARM::LDRT_POST_REG:
1891     case ARM::LDRT_POST_IMM:
1892       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1893         return MCDisassembler::Fail;
1894       break;
1895     default:
1896       break;
1897   }
1898 
1899   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1900     return MCDisassembler::Fail;
1901 
1902   ARM_AM::AddrOpc Op = ARM_AM::add;
1903   if (!fieldFromInstruction(Insn, 23, 1))
1904     Op = ARM_AM::sub;
1905 
1906   bool writeback = (P == 0) || (W == 1);
1907   unsigned idx_mode = 0;
1908   if (P && writeback)
1909     idx_mode = ARMII::IndexModePre;
1910   else if (!P && writeback)
1911     idx_mode = ARMII::IndexModePost;
1912 
1913   if (writeback && (Rn == 15 || Rn == Rt))
1914     S = MCDisassembler::SoftFail; // UNPREDICTABLE
1915 
1916   if (reg) {
1917     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1918       return MCDisassembler::Fail;
1919     ARM_AM::ShiftOpc Opc = ARM_AM::lsl;
1920     switch( fieldFromInstruction(Insn, 5, 2)) {
1921       case 0:
1922         Opc = ARM_AM::lsl;
1923         break;
1924       case 1:
1925         Opc = ARM_AM::lsr;
1926         break;
1927       case 2:
1928         Opc = ARM_AM::asr;
1929         break;
1930       case 3:
1931         Opc = ARM_AM::ror;
1932         break;
1933       default:
1934         return MCDisassembler::Fail;
1935     }
1936     unsigned amt = fieldFromInstruction(Insn, 7, 5);
1937     if (Opc == ARM_AM::ror && amt == 0)
1938       Opc = ARM_AM::rrx;
1939     unsigned imm = ARM_AM::getAM2Opc(Op, amt, Opc, idx_mode);
1940 
1941     Inst.addOperand(MCOperand::createImm(imm));
1942   } else {
1943     Inst.addOperand(MCOperand::createReg(0));
1944     unsigned tmp = ARM_AM::getAM2Opc(Op, imm, ARM_AM::lsl, idx_mode);
1945     Inst.addOperand(MCOperand::createImm(tmp));
1946   }
1947 
1948   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1949     return MCDisassembler::Fail;
1950 
1951   return S;
1952 }
1953 
1954 static DecodeStatus DecodeSORegMemOperand(MCInst &Inst, unsigned Val,
1955                                   uint64_t Address, const void *Decoder) {
1956   DecodeStatus S = MCDisassembler::Success;
1957 
1958   unsigned Rn = fieldFromInstruction(Val, 13, 4);
1959   unsigned Rm = fieldFromInstruction(Val,  0, 4);
1960   unsigned type = fieldFromInstruction(Val, 5, 2);
1961   unsigned imm = fieldFromInstruction(Val, 7, 5);
1962   unsigned U = fieldFromInstruction(Val, 12, 1);
1963 
1964   ARM_AM::ShiftOpc ShOp = ARM_AM::lsl;
1965   switch (type) {
1966     case 0:
1967       ShOp = ARM_AM::lsl;
1968       break;
1969     case 1:
1970       ShOp = ARM_AM::lsr;
1971       break;
1972     case 2:
1973       ShOp = ARM_AM::asr;
1974       break;
1975     case 3:
1976       ShOp = ARM_AM::ror;
1977       break;
1978   }
1979 
1980   if (ShOp == ARM_AM::ror && imm == 0)
1981     ShOp = ARM_AM::rrx;
1982 
1983   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1984     return MCDisassembler::Fail;
1985   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1986     return MCDisassembler::Fail;
1987   unsigned shift;
1988   if (U)
1989     shift = ARM_AM::getAM2Opc(ARM_AM::add, imm, ShOp);
1990   else
1991     shift = ARM_AM::getAM2Opc(ARM_AM::sub, imm, ShOp);
1992   Inst.addOperand(MCOperand::createImm(shift));
1993 
1994   return S;
1995 }
1996 
1997 static DecodeStatus
1998 DecodeAddrMode3Instruction(MCInst &Inst, unsigned Insn,
1999                            uint64_t Address, const void *Decoder) {
2000   DecodeStatus S = MCDisassembler::Success;
2001 
2002   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
2003   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2004   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2005   unsigned type = fieldFromInstruction(Insn, 22, 1);
2006   unsigned imm = fieldFromInstruction(Insn, 8, 4);
2007   unsigned U = ((~fieldFromInstruction(Insn, 23, 1)) & 1) << 8;
2008   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2009   unsigned W = fieldFromInstruction(Insn, 21, 1);
2010   unsigned P = fieldFromInstruction(Insn, 24, 1);
2011   unsigned Rt2 = Rt + 1;
2012 
2013   bool writeback = (W == 1) | (P == 0);
2014 
2015   // For {LD,ST}RD, Rt must be even, else undefined.
2016   switch (Inst.getOpcode()) {
2017     case ARM::STRD:
2018     case ARM::STRD_PRE:
2019     case ARM::STRD_POST:
2020     case ARM::LDRD:
2021     case ARM::LDRD_PRE:
2022     case ARM::LDRD_POST:
2023       if (Rt & 0x1) S = MCDisassembler::SoftFail;
2024       break;
2025     default:
2026       break;
2027   }
2028   switch (Inst.getOpcode()) {
2029     case ARM::STRD:
2030     case ARM::STRD_PRE:
2031     case ARM::STRD_POST:
2032       if (P == 0 && W == 1)
2033         S = MCDisassembler::SoftFail;
2034 
2035       if (writeback && (Rn == 15 || Rn == Rt || Rn == Rt2))
2036         S = MCDisassembler::SoftFail;
2037       if (type && Rm == 15)
2038         S = MCDisassembler::SoftFail;
2039       if (Rt2 == 15)
2040         S = MCDisassembler::SoftFail;
2041       if (!type && fieldFromInstruction(Insn, 8, 4))
2042         S = MCDisassembler::SoftFail;
2043       break;
2044     case ARM::STRH:
2045     case ARM::STRH_PRE:
2046     case ARM::STRH_POST:
2047       if (Rt == 15)
2048         S = MCDisassembler::SoftFail;
2049       if (writeback && (Rn == 15 || Rn == Rt))
2050         S = MCDisassembler::SoftFail;
2051       if (!type && Rm == 15)
2052         S = MCDisassembler::SoftFail;
2053       break;
2054     case ARM::LDRD:
2055     case ARM::LDRD_PRE:
2056     case ARM::LDRD_POST:
2057       if (type && Rn == 15) {
2058         if (Rt2 == 15)
2059           S = MCDisassembler::SoftFail;
2060         break;
2061       }
2062       if (P == 0 && W == 1)
2063         S = MCDisassembler::SoftFail;
2064       if (!type && (Rt2 == 15 || Rm == 15 || Rm == Rt || Rm == Rt2))
2065         S = MCDisassembler::SoftFail;
2066       if (!type && writeback && Rn == 15)
2067         S = MCDisassembler::SoftFail;
2068       if (writeback && (Rn == Rt || Rn == Rt2))
2069         S = MCDisassembler::SoftFail;
2070       break;
2071     case ARM::LDRH:
2072     case ARM::LDRH_PRE:
2073     case ARM::LDRH_POST:
2074       if (type && Rn == 15) {
2075         if (Rt == 15)
2076           S = MCDisassembler::SoftFail;
2077         break;
2078       }
2079       if (Rt == 15)
2080         S = MCDisassembler::SoftFail;
2081       if (!type && Rm == 15)
2082         S = MCDisassembler::SoftFail;
2083       if (!type && writeback && (Rn == 15 || Rn == Rt))
2084         S = MCDisassembler::SoftFail;
2085       break;
2086     case ARM::LDRSH:
2087     case ARM::LDRSH_PRE:
2088     case ARM::LDRSH_POST:
2089     case ARM::LDRSB:
2090     case ARM::LDRSB_PRE:
2091     case ARM::LDRSB_POST:
2092       if (type && Rn == 15) {
2093         if (Rt == 15)
2094           S = MCDisassembler::SoftFail;
2095         break;
2096       }
2097       if (type && (Rt == 15 || (writeback && Rn == Rt)))
2098         S = MCDisassembler::SoftFail;
2099       if (!type && (Rt == 15 || Rm == 15))
2100         S = MCDisassembler::SoftFail;
2101       if (!type && writeback && (Rn == 15 || Rn == Rt))
2102         S = MCDisassembler::SoftFail;
2103       break;
2104     default:
2105       break;
2106   }
2107 
2108   if (writeback) { // Writeback
2109     if (P)
2110       U |= ARMII::IndexModePre << 9;
2111     else
2112       U |= ARMII::IndexModePost << 9;
2113 
2114     // On stores, the writeback operand precedes Rt.
2115     switch (Inst.getOpcode()) {
2116     case ARM::STRD:
2117     case ARM::STRD_PRE:
2118     case ARM::STRD_POST:
2119     case ARM::STRH:
2120     case ARM::STRH_PRE:
2121     case ARM::STRH_POST:
2122       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2123         return MCDisassembler::Fail;
2124       break;
2125     default:
2126       break;
2127     }
2128   }
2129 
2130   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
2131     return MCDisassembler::Fail;
2132   switch (Inst.getOpcode()) {
2133     case ARM::STRD:
2134     case ARM::STRD_PRE:
2135     case ARM::STRD_POST:
2136     case ARM::LDRD:
2137     case ARM::LDRD_PRE:
2138     case ARM::LDRD_POST:
2139       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder)))
2140         return MCDisassembler::Fail;
2141       break;
2142     default:
2143       break;
2144   }
2145 
2146   if (writeback) {
2147     // On loads, the writeback operand comes after Rt.
2148     switch (Inst.getOpcode()) {
2149     case ARM::LDRD:
2150     case ARM::LDRD_PRE:
2151     case ARM::LDRD_POST:
2152     case ARM::LDRH:
2153     case ARM::LDRH_PRE:
2154     case ARM::LDRH_POST:
2155     case ARM::LDRSH:
2156     case ARM::LDRSH_PRE:
2157     case ARM::LDRSH_POST:
2158     case ARM::LDRSB:
2159     case ARM::LDRSB_PRE:
2160     case ARM::LDRSB_POST:
2161     case ARM::LDRHTr:
2162     case ARM::LDRSBTr:
2163       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2164         return MCDisassembler::Fail;
2165       break;
2166     default:
2167       break;
2168     }
2169   }
2170 
2171   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2172     return MCDisassembler::Fail;
2173 
2174   if (type) {
2175     Inst.addOperand(MCOperand::createReg(0));
2176     Inst.addOperand(MCOperand::createImm(U | (imm << 4) | Rm));
2177   } else {
2178     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2179     return MCDisassembler::Fail;
2180     Inst.addOperand(MCOperand::createImm(U));
2181   }
2182 
2183   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2184     return MCDisassembler::Fail;
2185 
2186   return S;
2187 }
2188 
2189 static DecodeStatus DecodeRFEInstruction(MCInst &Inst, unsigned Insn,
2190                                  uint64_t Address, const void *Decoder) {
2191   DecodeStatus S = MCDisassembler::Success;
2192 
2193   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2194   unsigned mode = fieldFromInstruction(Insn, 23, 2);
2195 
2196   switch (mode) {
2197     case 0:
2198       mode = ARM_AM::da;
2199       break;
2200     case 1:
2201       mode = ARM_AM::ia;
2202       break;
2203     case 2:
2204       mode = ARM_AM::db;
2205       break;
2206     case 3:
2207       mode = ARM_AM::ib;
2208       break;
2209   }
2210 
2211   Inst.addOperand(MCOperand::createImm(mode));
2212   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2213     return MCDisassembler::Fail;
2214 
2215   return S;
2216 }
2217 
2218 static DecodeStatus DecodeQADDInstruction(MCInst &Inst, unsigned Insn,
2219                                uint64_t Address, const void *Decoder) {
2220   DecodeStatus S = MCDisassembler::Success;
2221 
2222   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2223   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2224   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2225   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2226 
2227   if (pred == 0xF)
2228     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
2229 
2230   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2231     return MCDisassembler::Fail;
2232   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
2233     return MCDisassembler::Fail;
2234   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
2235     return MCDisassembler::Fail;
2236   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2237     return MCDisassembler::Fail;
2238   return S;
2239 }
2240 
2241 static DecodeStatus DecodeMemMultipleWritebackInstruction(MCInst &Inst,
2242                                   unsigned Insn,
2243                                   uint64_t Address, const void *Decoder) {
2244   DecodeStatus S = MCDisassembler::Success;
2245 
2246   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2247   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2248   unsigned reglist = fieldFromInstruction(Insn, 0, 16);
2249 
2250   if (pred == 0xF) {
2251     // Ambiguous with RFE and SRS
2252     switch (Inst.getOpcode()) {
2253       case ARM::LDMDA:
2254         Inst.setOpcode(ARM::RFEDA);
2255         break;
2256       case ARM::LDMDA_UPD:
2257         Inst.setOpcode(ARM::RFEDA_UPD);
2258         break;
2259       case ARM::LDMDB:
2260         Inst.setOpcode(ARM::RFEDB);
2261         break;
2262       case ARM::LDMDB_UPD:
2263         Inst.setOpcode(ARM::RFEDB_UPD);
2264         break;
2265       case ARM::LDMIA:
2266         Inst.setOpcode(ARM::RFEIA);
2267         break;
2268       case ARM::LDMIA_UPD:
2269         Inst.setOpcode(ARM::RFEIA_UPD);
2270         break;
2271       case ARM::LDMIB:
2272         Inst.setOpcode(ARM::RFEIB);
2273         break;
2274       case ARM::LDMIB_UPD:
2275         Inst.setOpcode(ARM::RFEIB_UPD);
2276         break;
2277       case ARM::STMDA:
2278         Inst.setOpcode(ARM::SRSDA);
2279         break;
2280       case ARM::STMDA_UPD:
2281         Inst.setOpcode(ARM::SRSDA_UPD);
2282         break;
2283       case ARM::STMDB:
2284         Inst.setOpcode(ARM::SRSDB);
2285         break;
2286       case ARM::STMDB_UPD:
2287         Inst.setOpcode(ARM::SRSDB_UPD);
2288         break;
2289       case ARM::STMIA:
2290         Inst.setOpcode(ARM::SRSIA);
2291         break;
2292       case ARM::STMIA_UPD:
2293         Inst.setOpcode(ARM::SRSIA_UPD);
2294         break;
2295       case ARM::STMIB:
2296         Inst.setOpcode(ARM::SRSIB);
2297         break;
2298       case ARM::STMIB_UPD:
2299         Inst.setOpcode(ARM::SRSIB_UPD);
2300         break;
2301       default:
2302         return MCDisassembler::Fail;
2303     }
2304 
2305     // For stores (which become SRS's, the only operand is the mode.
2306     if (fieldFromInstruction(Insn, 20, 1) == 0) {
2307       // Check SRS encoding constraints
2308       if (!(fieldFromInstruction(Insn, 22, 1) == 1 &&
2309             fieldFromInstruction(Insn, 20, 1) == 0))
2310         return MCDisassembler::Fail;
2311 
2312       Inst.addOperand(
2313           MCOperand::createImm(fieldFromInstruction(Insn, 0, 4)));
2314       return S;
2315     }
2316 
2317     return DecodeRFEInstruction(Inst, Insn, Address, Decoder);
2318   }
2319 
2320   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2321     return MCDisassembler::Fail;
2322   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2323     return MCDisassembler::Fail; // Tied
2324   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2325     return MCDisassembler::Fail;
2326   if (!Check(S, DecodeRegListOperand(Inst, reglist, Address, Decoder)))
2327     return MCDisassembler::Fail;
2328 
2329   return S;
2330 }
2331 
2332 // Check for UNPREDICTABLE predicated ESB instruction
2333 static DecodeStatus DecodeHINTInstruction(MCInst &Inst, unsigned Insn,
2334                                  uint64_t Address, const void *Decoder) {
2335   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2336   unsigned imm8 = fieldFromInstruction(Insn, 0, 8);
2337   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
2338   const FeatureBitset &FeatureBits = Dis->getSubtargetInfo().getFeatureBits();
2339 
2340   DecodeStatus S = MCDisassembler::Success;
2341 
2342   Inst.addOperand(MCOperand::createImm(imm8));
2343 
2344   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2345     return MCDisassembler::Fail;
2346 
2347   // ESB is unpredictable if pred != AL. Without the RAS extension, it is a NOP,
2348   // so all predicates should be allowed.
2349   if (imm8 == 0x10 && pred != 0xe && ((FeatureBits[ARM::FeatureRAS]) != 0))
2350     S = MCDisassembler::SoftFail;
2351 
2352   return S;
2353 }
2354 
2355 static DecodeStatus DecodeCPSInstruction(MCInst &Inst, unsigned Insn,
2356                                  uint64_t Address, const void *Decoder) {
2357   unsigned imod = fieldFromInstruction(Insn, 18, 2);
2358   unsigned M = fieldFromInstruction(Insn, 17, 1);
2359   unsigned iflags = fieldFromInstruction(Insn, 6, 3);
2360   unsigned mode = fieldFromInstruction(Insn, 0, 5);
2361 
2362   DecodeStatus S = MCDisassembler::Success;
2363 
2364   // This decoder is called from multiple location that do not check
2365   // the full encoding is valid before they do.
2366   if (fieldFromInstruction(Insn, 5, 1) != 0 ||
2367       fieldFromInstruction(Insn, 16, 1) != 0 ||
2368       fieldFromInstruction(Insn, 20, 8) != 0x10)
2369     return MCDisassembler::Fail;
2370 
2371   // imod == '01' --> UNPREDICTABLE
2372   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
2373   // return failure here.  The '01' imod value is unprintable, so there's
2374   // nothing useful we could do even if we returned UNPREDICTABLE.
2375 
2376   if (imod == 1) return MCDisassembler::Fail;
2377 
2378   if (imod && M) {
2379     Inst.setOpcode(ARM::CPS3p);
2380     Inst.addOperand(MCOperand::createImm(imod));
2381     Inst.addOperand(MCOperand::createImm(iflags));
2382     Inst.addOperand(MCOperand::createImm(mode));
2383   } else if (imod && !M) {
2384     Inst.setOpcode(ARM::CPS2p);
2385     Inst.addOperand(MCOperand::createImm(imod));
2386     Inst.addOperand(MCOperand::createImm(iflags));
2387     if (mode) S = MCDisassembler::SoftFail;
2388   } else if (!imod && M) {
2389     Inst.setOpcode(ARM::CPS1p);
2390     Inst.addOperand(MCOperand::createImm(mode));
2391     if (iflags) S = MCDisassembler::SoftFail;
2392   } else {
2393     // imod == '00' && M == '0' --> UNPREDICTABLE
2394     Inst.setOpcode(ARM::CPS1p);
2395     Inst.addOperand(MCOperand::createImm(mode));
2396     S = MCDisassembler::SoftFail;
2397   }
2398 
2399   return S;
2400 }
2401 
2402 static DecodeStatus DecodeT2CPSInstruction(MCInst &Inst, unsigned Insn,
2403                                  uint64_t Address, const void *Decoder) {
2404   unsigned imod = fieldFromInstruction(Insn, 9, 2);
2405   unsigned M = fieldFromInstruction(Insn, 8, 1);
2406   unsigned iflags = fieldFromInstruction(Insn, 5, 3);
2407   unsigned mode = fieldFromInstruction(Insn, 0, 5);
2408 
2409   DecodeStatus S = MCDisassembler::Success;
2410 
2411   // imod == '01' --> UNPREDICTABLE
2412   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
2413   // return failure here.  The '01' imod value is unprintable, so there's
2414   // nothing useful we could do even if we returned UNPREDICTABLE.
2415 
2416   if (imod == 1) return MCDisassembler::Fail;
2417 
2418   if (imod && M) {
2419     Inst.setOpcode(ARM::t2CPS3p);
2420     Inst.addOperand(MCOperand::createImm(imod));
2421     Inst.addOperand(MCOperand::createImm(iflags));
2422     Inst.addOperand(MCOperand::createImm(mode));
2423   } else if (imod && !M) {
2424     Inst.setOpcode(ARM::t2CPS2p);
2425     Inst.addOperand(MCOperand::createImm(imod));
2426     Inst.addOperand(MCOperand::createImm(iflags));
2427     if (mode) S = MCDisassembler::SoftFail;
2428   } else if (!imod && M) {
2429     Inst.setOpcode(ARM::t2CPS1p);
2430     Inst.addOperand(MCOperand::createImm(mode));
2431     if (iflags) S = MCDisassembler::SoftFail;
2432   } else {
2433     // imod == '00' && M == '0' --> this is a HINT instruction
2434     int imm = fieldFromInstruction(Insn, 0, 8);
2435     // HINT are defined only for immediate in [0..4]
2436     if(imm > 4) return MCDisassembler::Fail;
2437     Inst.setOpcode(ARM::t2HINT);
2438     Inst.addOperand(MCOperand::createImm(imm));
2439   }
2440 
2441   return S;
2442 }
2443 
2444 static DecodeStatus DecodeT2MOVTWInstruction(MCInst &Inst, unsigned Insn,
2445                                  uint64_t Address, const void *Decoder) {
2446   DecodeStatus S = MCDisassembler::Success;
2447 
2448   unsigned Rd = fieldFromInstruction(Insn, 8, 4);
2449   unsigned imm = 0;
2450 
2451   imm |= (fieldFromInstruction(Insn, 0, 8) << 0);
2452   imm |= (fieldFromInstruction(Insn, 12, 3) << 8);
2453   imm |= (fieldFromInstruction(Insn, 16, 4) << 12);
2454   imm |= (fieldFromInstruction(Insn, 26, 1) << 11);
2455 
2456   if (Inst.getOpcode() == ARM::t2MOVTi16)
2457     if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
2458       return MCDisassembler::Fail;
2459   if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
2460     return MCDisassembler::Fail;
2461 
2462   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
2463     Inst.addOperand(MCOperand::createImm(imm));
2464 
2465   return S;
2466 }
2467 
2468 static DecodeStatus DecodeArmMOVTWInstruction(MCInst &Inst, unsigned Insn,
2469                                  uint64_t Address, const void *Decoder) {
2470   DecodeStatus S = MCDisassembler::Success;
2471 
2472   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2473   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2474   unsigned imm = 0;
2475 
2476   imm |= (fieldFromInstruction(Insn, 0, 12) << 0);
2477   imm |= (fieldFromInstruction(Insn, 16, 4) << 12);
2478 
2479   if (Inst.getOpcode() == ARM::MOVTi16)
2480     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2481       return MCDisassembler::Fail;
2482 
2483   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2484     return MCDisassembler::Fail;
2485 
2486   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
2487     Inst.addOperand(MCOperand::createImm(imm));
2488 
2489   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2490     return MCDisassembler::Fail;
2491 
2492   return S;
2493 }
2494 
2495 static DecodeStatus DecodeSMLAInstruction(MCInst &Inst, unsigned Insn,
2496                                  uint64_t Address, const void *Decoder) {
2497   DecodeStatus S = MCDisassembler::Success;
2498 
2499   unsigned Rd = fieldFromInstruction(Insn, 16, 4);
2500   unsigned Rn = fieldFromInstruction(Insn, 0, 4);
2501   unsigned Rm = fieldFromInstruction(Insn, 8, 4);
2502   unsigned Ra = fieldFromInstruction(Insn, 12, 4);
2503   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2504 
2505   if (pred == 0xF)
2506     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
2507 
2508   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2509     return MCDisassembler::Fail;
2510   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
2511     return MCDisassembler::Fail;
2512   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
2513     return MCDisassembler::Fail;
2514   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Ra, Address, Decoder)))
2515     return MCDisassembler::Fail;
2516 
2517   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2518     return MCDisassembler::Fail;
2519 
2520   return S;
2521 }
2522 
2523 static DecodeStatus DecodeTSTInstruction(MCInst &Inst, unsigned Insn,
2524                                   uint64_t Address, const void *Decoder) {
2525   DecodeStatus S = MCDisassembler::Success;
2526 
2527   unsigned Pred = fieldFromInstruction(Insn, 28, 4);
2528   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2529   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2530 
2531   if (Pred == 0xF)
2532     return DecodeSETPANInstruction(Inst, Insn, Address, Decoder);
2533 
2534   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2535     return MCDisassembler::Fail;
2536   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2537     return MCDisassembler::Fail;
2538   if (!Check(S, DecodePredicateOperand(Inst, Pred, Address, Decoder)))
2539     return MCDisassembler::Fail;
2540 
2541   return S;
2542 }
2543 
2544 static DecodeStatus DecodeSETPANInstruction(MCInst &Inst, unsigned Insn,
2545                                   uint64_t Address, const void *Decoder) {
2546   DecodeStatus S = MCDisassembler::Success;
2547 
2548   unsigned Imm = fieldFromInstruction(Insn, 9, 1);
2549 
2550   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
2551   const FeatureBitset &FeatureBits = Dis->getSubtargetInfo().getFeatureBits();
2552 
2553   if (!FeatureBits[ARM::HasV8_1aOps] ||
2554       !FeatureBits[ARM::HasV8Ops])
2555     return MCDisassembler::Fail;
2556 
2557   // Decoder can be called from DecodeTST, which does not check the full
2558   // encoding is valid.
2559   if (fieldFromInstruction(Insn, 20,12) != 0xf11 ||
2560       fieldFromInstruction(Insn, 4,4) != 0)
2561     return MCDisassembler::Fail;
2562   if (fieldFromInstruction(Insn, 10,10) != 0 ||
2563       fieldFromInstruction(Insn, 0,4) != 0)
2564     S = MCDisassembler::SoftFail;
2565 
2566   Inst.setOpcode(ARM::SETPAN);
2567   Inst.addOperand(MCOperand::createImm(Imm));
2568 
2569   return S;
2570 }
2571 
2572 static DecodeStatus DecodeAddrModeImm12Operand(MCInst &Inst, unsigned Val,
2573                            uint64_t Address, const void *Decoder) {
2574   DecodeStatus S = MCDisassembler::Success;
2575 
2576   unsigned add = fieldFromInstruction(Val, 12, 1);
2577   unsigned imm = fieldFromInstruction(Val, 0, 12);
2578   unsigned Rn = fieldFromInstruction(Val, 13, 4);
2579 
2580   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2581     return MCDisassembler::Fail;
2582 
2583   if (!add) imm *= -1;
2584   if (imm == 0 && !add) imm = INT32_MIN;
2585   Inst.addOperand(MCOperand::createImm(imm));
2586   if (Rn == 15)
2587     tryAddingPcLoadReferenceComment(Address, Address + imm + 8, Decoder);
2588 
2589   return S;
2590 }
2591 
2592 static DecodeStatus DecodeAddrMode5Operand(MCInst &Inst, unsigned Val,
2593                                    uint64_t Address, const void *Decoder) {
2594   DecodeStatus S = MCDisassembler::Success;
2595 
2596   unsigned Rn = fieldFromInstruction(Val, 9, 4);
2597   // U == 1 to add imm, 0 to subtract it.
2598   unsigned U = fieldFromInstruction(Val, 8, 1);
2599   unsigned imm = fieldFromInstruction(Val, 0, 8);
2600 
2601   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2602     return MCDisassembler::Fail;
2603 
2604   if (U)
2605     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5Opc(ARM_AM::add, imm)));
2606   else
2607     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5Opc(ARM_AM::sub, imm)));
2608 
2609   return S;
2610 }
2611 
2612 static DecodeStatus DecodeAddrMode5FP16Operand(MCInst &Inst, unsigned Val,
2613                                    uint64_t Address, const void *Decoder) {
2614   DecodeStatus S = MCDisassembler::Success;
2615 
2616   unsigned Rn = fieldFromInstruction(Val, 9, 4);
2617   // U == 1 to add imm, 0 to subtract it.
2618   unsigned U = fieldFromInstruction(Val, 8, 1);
2619   unsigned imm = fieldFromInstruction(Val, 0, 8);
2620 
2621   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2622     return MCDisassembler::Fail;
2623 
2624   if (U)
2625     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5FP16Opc(ARM_AM::add, imm)));
2626   else
2627     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5FP16Opc(ARM_AM::sub, imm)));
2628 
2629   return S;
2630 }
2631 
2632 static DecodeStatus DecodeAddrMode7Operand(MCInst &Inst, unsigned Val,
2633                                    uint64_t Address, const void *Decoder) {
2634   return DecodeGPRRegisterClass(Inst, Val, Address, Decoder);
2635 }
2636 
2637 static DecodeStatus
2638 DecodeT2BInstruction(MCInst &Inst, unsigned Insn,
2639                      uint64_t Address, const void *Decoder) {
2640   DecodeStatus Status = MCDisassembler::Success;
2641 
2642   // Note the J1 and J2 values are from the encoded instruction.  So here
2643   // change them to I1 and I2 values via as documented:
2644   // I1 = NOT(J1 EOR S);
2645   // I2 = NOT(J2 EOR S);
2646   // and build the imm32 with one trailing zero as documented:
2647   // imm32 = SignExtend(S:I1:I2:imm10:imm11:'0', 32);
2648   unsigned S = fieldFromInstruction(Insn, 26, 1);
2649   unsigned J1 = fieldFromInstruction(Insn, 13, 1);
2650   unsigned J2 = fieldFromInstruction(Insn, 11, 1);
2651   unsigned I1 = !(J1 ^ S);
2652   unsigned I2 = !(J2 ^ S);
2653   unsigned imm10 = fieldFromInstruction(Insn, 16, 10);
2654   unsigned imm11 = fieldFromInstruction(Insn, 0, 11);
2655   unsigned tmp = (S << 23) | (I1 << 22) | (I2 << 21) | (imm10 << 11) | imm11;
2656   int imm32 = SignExtend32<25>(tmp << 1);
2657   if (!tryAddingSymbolicOperand(Address, Address + imm32 + 4,
2658                                 true, 4, Inst, Decoder))
2659     Inst.addOperand(MCOperand::createImm(imm32));
2660 
2661   return Status;
2662 }
2663 
2664 static DecodeStatus
2665 DecodeBranchImmInstruction(MCInst &Inst, unsigned Insn,
2666                            uint64_t Address, const void *Decoder) {
2667   DecodeStatus S = MCDisassembler::Success;
2668 
2669   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2670   unsigned imm = fieldFromInstruction(Insn, 0, 24) << 2;
2671 
2672   if (pred == 0xF) {
2673     Inst.setOpcode(ARM::BLXi);
2674     imm |= fieldFromInstruction(Insn, 24, 1) << 1;
2675     if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<26>(imm) + 8,
2676                                   true, 4, Inst, Decoder))
2677     Inst.addOperand(MCOperand::createImm(SignExtend32<26>(imm)));
2678     return S;
2679   }
2680 
2681   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<26>(imm) + 8,
2682                                 true, 4, Inst, Decoder))
2683     Inst.addOperand(MCOperand::createImm(SignExtend32<26>(imm)));
2684 
2685   // We already have BL_pred for BL w/ predicate, no need to add addition
2686   // predicate opreands for BL
2687   if (Inst.getOpcode() != ARM::BL)
2688     if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2689       return MCDisassembler::Fail;
2690 
2691   return S;
2692 }
2693 
2694 static DecodeStatus DecodeAddrMode6Operand(MCInst &Inst, unsigned Val,
2695                                    uint64_t Address, const void *Decoder) {
2696   DecodeStatus S = MCDisassembler::Success;
2697 
2698   unsigned Rm = fieldFromInstruction(Val, 0, 4);
2699   unsigned align = fieldFromInstruction(Val, 4, 2);
2700 
2701   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2702     return MCDisassembler::Fail;
2703   if (!align)
2704     Inst.addOperand(MCOperand::createImm(0));
2705   else
2706     Inst.addOperand(MCOperand::createImm(4 << align));
2707 
2708   return S;
2709 }
2710 
2711 static DecodeStatus DecodeVLDInstruction(MCInst &Inst, unsigned Insn,
2712                                    uint64_t Address, const void *Decoder) {
2713   DecodeStatus S = MCDisassembler::Success;
2714 
2715   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2716   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
2717   unsigned wb = fieldFromInstruction(Insn, 16, 4);
2718   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2719   Rn |= fieldFromInstruction(Insn, 4, 2) << 4;
2720   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2721 
2722   // First output register
2723   switch (Inst.getOpcode()) {
2724   case ARM::VLD1q16: case ARM::VLD1q32: case ARM::VLD1q64: case ARM::VLD1q8:
2725   case ARM::VLD1q16wb_fixed: case ARM::VLD1q16wb_register:
2726   case ARM::VLD1q32wb_fixed: case ARM::VLD1q32wb_register:
2727   case ARM::VLD1q64wb_fixed: case ARM::VLD1q64wb_register:
2728   case ARM::VLD1q8wb_fixed: case ARM::VLD1q8wb_register:
2729   case ARM::VLD2d16: case ARM::VLD2d32: case ARM::VLD2d8:
2730   case ARM::VLD2d16wb_fixed: case ARM::VLD2d16wb_register:
2731   case ARM::VLD2d32wb_fixed: case ARM::VLD2d32wb_register:
2732   case ARM::VLD2d8wb_fixed: case ARM::VLD2d8wb_register:
2733     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
2734       return MCDisassembler::Fail;
2735     break;
2736   case ARM::VLD2b16:
2737   case ARM::VLD2b32:
2738   case ARM::VLD2b8:
2739   case ARM::VLD2b16wb_fixed:
2740   case ARM::VLD2b16wb_register:
2741   case ARM::VLD2b32wb_fixed:
2742   case ARM::VLD2b32wb_register:
2743   case ARM::VLD2b8wb_fixed:
2744   case ARM::VLD2b8wb_register:
2745     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
2746       return MCDisassembler::Fail;
2747     break;
2748   default:
2749     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2750       return MCDisassembler::Fail;
2751   }
2752 
2753   // Second output register
2754   switch (Inst.getOpcode()) {
2755     case ARM::VLD3d8:
2756     case ARM::VLD3d16:
2757     case ARM::VLD3d32:
2758     case ARM::VLD3d8_UPD:
2759     case ARM::VLD3d16_UPD:
2760     case ARM::VLD3d32_UPD:
2761     case ARM::VLD4d8:
2762     case ARM::VLD4d16:
2763     case ARM::VLD4d32:
2764     case ARM::VLD4d8_UPD:
2765     case ARM::VLD4d16_UPD:
2766     case ARM::VLD4d32_UPD:
2767       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
2768         return MCDisassembler::Fail;
2769       break;
2770     case ARM::VLD3q8:
2771     case ARM::VLD3q16:
2772     case ARM::VLD3q32:
2773     case ARM::VLD3q8_UPD:
2774     case ARM::VLD3q16_UPD:
2775     case ARM::VLD3q32_UPD:
2776     case ARM::VLD4q8:
2777     case ARM::VLD4q16:
2778     case ARM::VLD4q32:
2779     case ARM::VLD4q8_UPD:
2780     case ARM::VLD4q16_UPD:
2781     case ARM::VLD4q32_UPD:
2782       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2783         return MCDisassembler::Fail;
2784       break;
2785     default:
2786       break;
2787   }
2788 
2789   // Third output register
2790   switch(Inst.getOpcode()) {
2791     case ARM::VLD3d8:
2792     case ARM::VLD3d16:
2793     case ARM::VLD3d32:
2794     case ARM::VLD3d8_UPD:
2795     case ARM::VLD3d16_UPD:
2796     case ARM::VLD3d32_UPD:
2797     case ARM::VLD4d8:
2798     case ARM::VLD4d16:
2799     case ARM::VLD4d32:
2800     case ARM::VLD4d8_UPD:
2801     case ARM::VLD4d16_UPD:
2802     case ARM::VLD4d32_UPD:
2803       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2804         return MCDisassembler::Fail;
2805       break;
2806     case ARM::VLD3q8:
2807     case ARM::VLD3q16:
2808     case ARM::VLD3q32:
2809     case ARM::VLD3q8_UPD:
2810     case ARM::VLD3q16_UPD:
2811     case ARM::VLD3q32_UPD:
2812     case ARM::VLD4q8:
2813     case ARM::VLD4q16:
2814     case ARM::VLD4q32:
2815     case ARM::VLD4q8_UPD:
2816     case ARM::VLD4q16_UPD:
2817     case ARM::VLD4q32_UPD:
2818       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
2819         return MCDisassembler::Fail;
2820       break;
2821     default:
2822       break;
2823   }
2824 
2825   // Fourth output register
2826   switch (Inst.getOpcode()) {
2827     case ARM::VLD4d8:
2828     case ARM::VLD4d16:
2829     case ARM::VLD4d32:
2830     case ARM::VLD4d8_UPD:
2831     case ARM::VLD4d16_UPD:
2832     case ARM::VLD4d32_UPD:
2833       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
2834         return MCDisassembler::Fail;
2835       break;
2836     case ARM::VLD4q8:
2837     case ARM::VLD4q16:
2838     case ARM::VLD4q32:
2839     case ARM::VLD4q8_UPD:
2840     case ARM::VLD4q16_UPD:
2841     case ARM::VLD4q32_UPD:
2842       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
2843         return MCDisassembler::Fail;
2844       break;
2845     default:
2846       break;
2847   }
2848 
2849   // Writeback operand
2850   switch (Inst.getOpcode()) {
2851     case ARM::VLD1d8wb_fixed:
2852     case ARM::VLD1d16wb_fixed:
2853     case ARM::VLD1d32wb_fixed:
2854     case ARM::VLD1d64wb_fixed:
2855     case ARM::VLD1d8wb_register:
2856     case ARM::VLD1d16wb_register:
2857     case ARM::VLD1d32wb_register:
2858     case ARM::VLD1d64wb_register:
2859     case ARM::VLD1q8wb_fixed:
2860     case ARM::VLD1q16wb_fixed:
2861     case ARM::VLD1q32wb_fixed:
2862     case ARM::VLD1q64wb_fixed:
2863     case ARM::VLD1q8wb_register:
2864     case ARM::VLD1q16wb_register:
2865     case ARM::VLD1q32wb_register:
2866     case ARM::VLD1q64wb_register:
2867     case ARM::VLD1d8Twb_fixed:
2868     case ARM::VLD1d8Twb_register:
2869     case ARM::VLD1d16Twb_fixed:
2870     case ARM::VLD1d16Twb_register:
2871     case ARM::VLD1d32Twb_fixed:
2872     case ARM::VLD1d32Twb_register:
2873     case ARM::VLD1d64Twb_fixed:
2874     case ARM::VLD1d64Twb_register:
2875     case ARM::VLD1d8Qwb_fixed:
2876     case ARM::VLD1d8Qwb_register:
2877     case ARM::VLD1d16Qwb_fixed:
2878     case ARM::VLD1d16Qwb_register:
2879     case ARM::VLD1d32Qwb_fixed:
2880     case ARM::VLD1d32Qwb_register:
2881     case ARM::VLD1d64Qwb_fixed:
2882     case ARM::VLD1d64Qwb_register:
2883     case ARM::VLD2d8wb_fixed:
2884     case ARM::VLD2d16wb_fixed:
2885     case ARM::VLD2d32wb_fixed:
2886     case ARM::VLD2q8wb_fixed:
2887     case ARM::VLD2q16wb_fixed:
2888     case ARM::VLD2q32wb_fixed:
2889     case ARM::VLD2d8wb_register:
2890     case ARM::VLD2d16wb_register:
2891     case ARM::VLD2d32wb_register:
2892     case ARM::VLD2q8wb_register:
2893     case ARM::VLD2q16wb_register:
2894     case ARM::VLD2q32wb_register:
2895     case ARM::VLD2b8wb_fixed:
2896     case ARM::VLD2b16wb_fixed:
2897     case ARM::VLD2b32wb_fixed:
2898     case ARM::VLD2b8wb_register:
2899     case ARM::VLD2b16wb_register:
2900     case ARM::VLD2b32wb_register:
2901       Inst.addOperand(MCOperand::createImm(0));
2902       break;
2903     case ARM::VLD3d8_UPD:
2904     case ARM::VLD3d16_UPD:
2905     case ARM::VLD3d32_UPD:
2906     case ARM::VLD3q8_UPD:
2907     case ARM::VLD3q16_UPD:
2908     case ARM::VLD3q32_UPD:
2909     case ARM::VLD4d8_UPD:
2910     case ARM::VLD4d16_UPD:
2911     case ARM::VLD4d32_UPD:
2912     case ARM::VLD4q8_UPD:
2913     case ARM::VLD4q16_UPD:
2914     case ARM::VLD4q32_UPD:
2915       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
2916         return MCDisassembler::Fail;
2917       break;
2918     default:
2919       break;
2920   }
2921 
2922   // AddrMode6 Base (register+alignment)
2923   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
2924     return MCDisassembler::Fail;
2925 
2926   // AddrMode6 Offset (register)
2927   switch (Inst.getOpcode()) {
2928   default:
2929     // The below have been updated to have explicit am6offset split
2930     // between fixed and register offset. For those instructions not
2931     // yet updated, we need to add an additional reg0 operand for the
2932     // fixed variant.
2933     //
2934     // The fixed offset encodes as Rm == 0xd, so we check for that.
2935     if (Rm == 0xd) {
2936       Inst.addOperand(MCOperand::createReg(0));
2937       break;
2938     }
2939     // Fall through to handle the register offset variant.
2940     LLVM_FALLTHROUGH;
2941   case ARM::VLD1d8wb_fixed:
2942   case ARM::VLD1d16wb_fixed:
2943   case ARM::VLD1d32wb_fixed:
2944   case ARM::VLD1d64wb_fixed:
2945   case ARM::VLD1d8Twb_fixed:
2946   case ARM::VLD1d16Twb_fixed:
2947   case ARM::VLD1d32Twb_fixed:
2948   case ARM::VLD1d64Twb_fixed:
2949   case ARM::VLD1d8Qwb_fixed:
2950   case ARM::VLD1d16Qwb_fixed:
2951   case ARM::VLD1d32Qwb_fixed:
2952   case ARM::VLD1d64Qwb_fixed:
2953   case ARM::VLD1d8wb_register:
2954   case ARM::VLD1d16wb_register:
2955   case ARM::VLD1d32wb_register:
2956   case ARM::VLD1d64wb_register:
2957   case ARM::VLD1q8wb_fixed:
2958   case ARM::VLD1q16wb_fixed:
2959   case ARM::VLD1q32wb_fixed:
2960   case ARM::VLD1q64wb_fixed:
2961   case ARM::VLD1q8wb_register:
2962   case ARM::VLD1q16wb_register:
2963   case ARM::VLD1q32wb_register:
2964   case ARM::VLD1q64wb_register:
2965     // The fixed offset post-increment encodes Rm == 0xd. The no-writeback
2966     // variant encodes Rm == 0xf. Anything else is a register offset post-
2967     // increment and we need to add the register operand to the instruction.
2968     if (Rm != 0xD && Rm != 0xF &&
2969         !Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2970       return MCDisassembler::Fail;
2971     break;
2972   case ARM::VLD2d8wb_fixed:
2973   case ARM::VLD2d16wb_fixed:
2974   case ARM::VLD2d32wb_fixed:
2975   case ARM::VLD2b8wb_fixed:
2976   case ARM::VLD2b16wb_fixed:
2977   case ARM::VLD2b32wb_fixed:
2978   case ARM::VLD2q8wb_fixed:
2979   case ARM::VLD2q16wb_fixed:
2980   case ARM::VLD2q32wb_fixed:
2981     break;
2982   }
2983 
2984   return S;
2985 }
2986 
2987 static DecodeStatus DecodeVLDST1Instruction(MCInst &Inst, unsigned Insn,
2988                                    uint64_t Address, const void *Decoder) {
2989   unsigned type = fieldFromInstruction(Insn, 8, 4);
2990   unsigned align = fieldFromInstruction(Insn, 4, 2);
2991   if (type == 6 && (align & 2)) return MCDisassembler::Fail;
2992   if (type == 7 && (align & 2)) return MCDisassembler::Fail;
2993   if (type == 10 && align == 3) return MCDisassembler::Fail;
2994 
2995   unsigned load = fieldFromInstruction(Insn, 21, 1);
2996   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2997               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2998 }
2999 
3000 static DecodeStatus DecodeVLDST2Instruction(MCInst &Inst, unsigned Insn,
3001                                    uint64_t Address, const void *Decoder) {
3002   unsigned size = fieldFromInstruction(Insn, 6, 2);
3003   if (size == 3) return MCDisassembler::Fail;
3004 
3005   unsigned type = fieldFromInstruction(Insn, 8, 4);
3006   unsigned align = fieldFromInstruction(Insn, 4, 2);
3007   if (type == 8 && align == 3) return MCDisassembler::Fail;
3008   if (type == 9 && align == 3) return MCDisassembler::Fail;
3009 
3010   unsigned load = fieldFromInstruction(Insn, 21, 1);
3011   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
3012               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
3013 }
3014 
3015 static DecodeStatus DecodeVLDST3Instruction(MCInst &Inst, unsigned Insn,
3016                                    uint64_t Address, const void *Decoder) {
3017   unsigned size = fieldFromInstruction(Insn, 6, 2);
3018   if (size == 3) return MCDisassembler::Fail;
3019 
3020   unsigned align = fieldFromInstruction(Insn, 4, 2);
3021   if (align & 2) return MCDisassembler::Fail;
3022 
3023   unsigned load = fieldFromInstruction(Insn, 21, 1);
3024   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
3025               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
3026 }
3027 
3028 static DecodeStatus DecodeVLDST4Instruction(MCInst &Inst, unsigned Insn,
3029                                    uint64_t Address, const void *Decoder) {
3030   unsigned size = fieldFromInstruction(Insn, 6, 2);
3031   if (size == 3) return MCDisassembler::Fail;
3032 
3033   unsigned load = fieldFromInstruction(Insn, 21, 1);
3034   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
3035               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
3036 }
3037 
3038 static DecodeStatus DecodeVSTInstruction(MCInst &Inst, unsigned Insn,
3039                                  uint64_t Address, const void *Decoder) {
3040   DecodeStatus S = MCDisassembler::Success;
3041 
3042   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3043   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3044   unsigned wb = fieldFromInstruction(Insn, 16, 4);
3045   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3046   Rn |= fieldFromInstruction(Insn, 4, 2) << 4;
3047   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3048 
3049   // Writeback Operand
3050   switch (Inst.getOpcode()) {
3051     case ARM::VST1d8wb_fixed:
3052     case ARM::VST1d16wb_fixed:
3053     case ARM::VST1d32wb_fixed:
3054     case ARM::VST1d64wb_fixed:
3055     case ARM::VST1d8wb_register:
3056     case ARM::VST1d16wb_register:
3057     case ARM::VST1d32wb_register:
3058     case ARM::VST1d64wb_register:
3059     case ARM::VST1q8wb_fixed:
3060     case ARM::VST1q16wb_fixed:
3061     case ARM::VST1q32wb_fixed:
3062     case ARM::VST1q64wb_fixed:
3063     case ARM::VST1q8wb_register:
3064     case ARM::VST1q16wb_register:
3065     case ARM::VST1q32wb_register:
3066     case ARM::VST1q64wb_register:
3067     case ARM::VST1d8Twb_fixed:
3068     case ARM::VST1d16Twb_fixed:
3069     case ARM::VST1d32Twb_fixed:
3070     case ARM::VST1d64Twb_fixed:
3071     case ARM::VST1d8Twb_register:
3072     case ARM::VST1d16Twb_register:
3073     case ARM::VST1d32Twb_register:
3074     case ARM::VST1d64Twb_register:
3075     case ARM::VST1d8Qwb_fixed:
3076     case ARM::VST1d16Qwb_fixed:
3077     case ARM::VST1d32Qwb_fixed:
3078     case ARM::VST1d64Qwb_fixed:
3079     case ARM::VST1d8Qwb_register:
3080     case ARM::VST1d16Qwb_register:
3081     case ARM::VST1d32Qwb_register:
3082     case ARM::VST1d64Qwb_register:
3083     case ARM::VST2d8wb_fixed:
3084     case ARM::VST2d16wb_fixed:
3085     case ARM::VST2d32wb_fixed:
3086     case ARM::VST2d8wb_register:
3087     case ARM::VST2d16wb_register:
3088     case ARM::VST2d32wb_register:
3089     case ARM::VST2q8wb_fixed:
3090     case ARM::VST2q16wb_fixed:
3091     case ARM::VST2q32wb_fixed:
3092     case ARM::VST2q8wb_register:
3093     case ARM::VST2q16wb_register:
3094     case ARM::VST2q32wb_register:
3095     case ARM::VST2b8wb_fixed:
3096     case ARM::VST2b16wb_fixed:
3097     case ARM::VST2b32wb_fixed:
3098     case ARM::VST2b8wb_register:
3099     case ARM::VST2b16wb_register:
3100     case ARM::VST2b32wb_register:
3101       if (Rm == 0xF)
3102         return MCDisassembler::Fail;
3103       Inst.addOperand(MCOperand::createImm(0));
3104       break;
3105     case ARM::VST3d8_UPD:
3106     case ARM::VST3d16_UPD:
3107     case ARM::VST3d32_UPD:
3108     case ARM::VST3q8_UPD:
3109     case ARM::VST3q16_UPD:
3110     case ARM::VST3q32_UPD:
3111     case ARM::VST4d8_UPD:
3112     case ARM::VST4d16_UPD:
3113     case ARM::VST4d32_UPD:
3114     case ARM::VST4q8_UPD:
3115     case ARM::VST4q16_UPD:
3116     case ARM::VST4q32_UPD:
3117       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
3118         return MCDisassembler::Fail;
3119       break;
3120     default:
3121       break;
3122   }
3123 
3124   // AddrMode6 Base (register+alignment)
3125   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
3126     return MCDisassembler::Fail;
3127 
3128   // AddrMode6 Offset (register)
3129   switch (Inst.getOpcode()) {
3130     default:
3131       if (Rm == 0xD)
3132         Inst.addOperand(MCOperand::createReg(0));
3133       else if (Rm != 0xF) {
3134         if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3135           return MCDisassembler::Fail;
3136       }
3137       break;
3138     case ARM::VST1d8wb_fixed:
3139     case ARM::VST1d16wb_fixed:
3140     case ARM::VST1d32wb_fixed:
3141     case ARM::VST1d64wb_fixed:
3142     case ARM::VST1q8wb_fixed:
3143     case ARM::VST1q16wb_fixed:
3144     case ARM::VST1q32wb_fixed:
3145     case ARM::VST1q64wb_fixed:
3146     case ARM::VST1d8Twb_fixed:
3147     case ARM::VST1d16Twb_fixed:
3148     case ARM::VST1d32Twb_fixed:
3149     case ARM::VST1d64Twb_fixed:
3150     case ARM::VST1d8Qwb_fixed:
3151     case ARM::VST1d16Qwb_fixed:
3152     case ARM::VST1d32Qwb_fixed:
3153     case ARM::VST1d64Qwb_fixed:
3154     case ARM::VST2d8wb_fixed:
3155     case ARM::VST2d16wb_fixed:
3156     case ARM::VST2d32wb_fixed:
3157     case ARM::VST2q8wb_fixed:
3158     case ARM::VST2q16wb_fixed:
3159     case ARM::VST2q32wb_fixed:
3160     case ARM::VST2b8wb_fixed:
3161     case ARM::VST2b16wb_fixed:
3162     case ARM::VST2b32wb_fixed:
3163       break;
3164   }
3165 
3166   // First input register
3167   switch (Inst.getOpcode()) {
3168   case ARM::VST1q16:
3169   case ARM::VST1q32:
3170   case ARM::VST1q64:
3171   case ARM::VST1q8:
3172   case ARM::VST1q16wb_fixed:
3173   case ARM::VST1q16wb_register:
3174   case ARM::VST1q32wb_fixed:
3175   case ARM::VST1q32wb_register:
3176   case ARM::VST1q64wb_fixed:
3177   case ARM::VST1q64wb_register:
3178   case ARM::VST1q8wb_fixed:
3179   case ARM::VST1q8wb_register:
3180   case ARM::VST2d16:
3181   case ARM::VST2d32:
3182   case ARM::VST2d8:
3183   case ARM::VST2d16wb_fixed:
3184   case ARM::VST2d16wb_register:
3185   case ARM::VST2d32wb_fixed:
3186   case ARM::VST2d32wb_register:
3187   case ARM::VST2d8wb_fixed:
3188   case ARM::VST2d8wb_register:
3189     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3190       return MCDisassembler::Fail;
3191     break;
3192   case ARM::VST2b16:
3193   case ARM::VST2b32:
3194   case ARM::VST2b8:
3195   case ARM::VST2b16wb_fixed:
3196   case ARM::VST2b16wb_register:
3197   case ARM::VST2b32wb_fixed:
3198   case ARM::VST2b32wb_register:
3199   case ARM::VST2b8wb_fixed:
3200   case ARM::VST2b8wb_register:
3201     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
3202       return MCDisassembler::Fail;
3203     break;
3204   default:
3205     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3206       return MCDisassembler::Fail;
3207   }
3208 
3209   // Second input register
3210   switch (Inst.getOpcode()) {
3211     case ARM::VST3d8:
3212     case ARM::VST3d16:
3213     case ARM::VST3d32:
3214     case ARM::VST3d8_UPD:
3215     case ARM::VST3d16_UPD:
3216     case ARM::VST3d32_UPD:
3217     case ARM::VST4d8:
3218     case ARM::VST4d16:
3219     case ARM::VST4d32:
3220     case ARM::VST4d8_UPD:
3221     case ARM::VST4d16_UPD:
3222     case ARM::VST4d32_UPD:
3223       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
3224         return MCDisassembler::Fail;
3225       break;
3226     case ARM::VST3q8:
3227     case ARM::VST3q16:
3228     case ARM::VST3q32:
3229     case ARM::VST3q8_UPD:
3230     case ARM::VST3q16_UPD:
3231     case ARM::VST3q32_UPD:
3232     case ARM::VST4q8:
3233     case ARM::VST4q16:
3234     case ARM::VST4q32:
3235     case ARM::VST4q8_UPD:
3236     case ARM::VST4q16_UPD:
3237     case ARM::VST4q32_UPD:
3238       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
3239         return MCDisassembler::Fail;
3240       break;
3241     default:
3242       break;
3243   }
3244 
3245   // Third input register
3246   switch (Inst.getOpcode()) {
3247     case ARM::VST3d8:
3248     case ARM::VST3d16:
3249     case ARM::VST3d32:
3250     case ARM::VST3d8_UPD:
3251     case ARM::VST3d16_UPD:
3252     case ARM::VST3d32_UPD:
3253     case ARM::VST4d8:
3254     case ARM::VST4d16:
3255     case ARM::VST4d32:
3256     case ARM::VST4d8_UPD:
3257     case ARM::VST4d16_UPD:
3258     case ARM::VST4d32_UPD:
3259       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
3260         return MCDisassembler::Fail;
3261       break;
3262     case ARM::VST3q8:
3263     case ARM::VST3q16:
3264     case ARM::VST3q32:
3265     case ARM::VST3q8_UPD:
3266     case ARM::VST3q16_UPD:
3267     case ARM::VST3q32_UPD:
3268     case ARM::VST4q8:
3269     case ARM::VST4q16:
3270     case ARM::VST4q32:
3271     case ARM::VST4q8_UPD:
3272     case ARM::VST4q16_UPD:
3273     case ARM::VST4q32_UPD:
3274       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
3275         return MCDisassembler::Fail;
3276       break;
3277     default:
3278       break;
3279   }
3280 
3281   // Fourth input register
3282   switch (Inst.getOpcode()) {
3283     case ARM::VST4d8:
3284     case ARM::VST4d16:
3285     case ARM::VST4d32:
3286     case ARM::VST4d8_UPD:
3287     case ARM::VST4d16_UPD:
3288     case ARM::VST4d32_UPD:
3289       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
3290         return MCDisassembler::Fail;
3291       break;
3292     case ARM::VST4q8:
3293     case ARM::VST4q16:
3294     case ARM::VST4q32:
3295     case ARM::VST4q8_UPD:
3296     case ARM::VST4q16_UPD:
3297     case ARM::VST4q32_UPD:
3298       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
3299         return MCDisassembler::Fail;
3300       break;
3301     default:
3302       break;
3303   }
3304 
3305   return S;
3306 }
3307 
3308 static DecodeStatus DecodeVLD1DupInstruction(MCInst &Inst, unsigned Insn,
3309                                     uint64_t Address, const void *Decoder) {
3310   DecodeStatus S = MCDisassembler::Success;
3311 
3312   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3313   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3314   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3315   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3316   unsigned align = fieldFromInstruction(Insn, 4, 1);
3317   unsigned size = fieldFromInstruction(Insn, 6, 2);
3318 
3319   if (size == 0 && align == 1)
3320     return MCDisassembler::Fail;
3321   align *= (1 << size);
3322 
3323   switch (Inst.getOpcode()) {
3324   case ARM::VLD1DUPq16: case ARM::VLD1DUPq32: case ARM::VLD1DUPq8:
3325   case ARM::VLD1DUPq16wb_fixed: case ARM::VLD1DUPq16wb_register:
3326   case ARM::VLD1DUPq32wb_fixed: case ARM::VLD1DUPq32wb_register:
3327   case ARM::VLD1DUPq8wb_fixed: case ARM::VLD1DUPq8wb_register:
3328     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3329       return MCDisassembler::Fail;
3330     break;
3331   default:
3332     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3333       return MCDisassembler::Fail;
3334     break;
3335   }
3336   if (Rm != 0xF) {
3337     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3338       return MCDisassembler::Fail;
3339   }
3340 
3341   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3342     return MCDisassembler::Fail;
3343   Inst.addOperand(MCOperand::createImm(align));
3344 
3345   // The fixed offset post-increment encodes Rm == 0xd. The no-writeback
3346   // variant encodes Rm == 0xf. Anything else is a register offset post-
3347   // increment and we need to add the register operand to the instruction.
3348   if (Rm != 0xD && Rm != 0xF &&
3349       !Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3350     return MCDisassembler::Fail;
3351 
3352   return S;
3353 }
3354 
3355 static DecodeStatus DecodeVLD2DupInstruction(MCInst &Inst, unsigned Insn,
3356                                     uint64_t Address, const void *Decoder) {
3357   DecodeStatus S = MCDisassembler::Success;
3358 
3359   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3360   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3361   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3362   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3363   unsigned align = fieldFromInstruction(Insn, 4, 1);
3364   unsigned size = 1 << fieldFromInstruction(Insn, 6, 2);
3365   align *= 2*size;
3366 
3367   switch (Inst.getOpcode()) {
3368   case ARM::VLD2DUPd16: case ARM::VLD2DUPd32: case ARM::VLD2DUPd8:
3369   case ARM::VLD2DUPd16wb_fixed: case ARM::VLD2DUPd16wb_register:
3370   case ARM::VLD2DUPd32wb_fixed: case ARM::VLD2DUPd32wb_register:
3371   case ARM::VLD2DUPd8wb_fixed: case ARM::VLD2DUPd8wb_register:
3372     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3373       return MCDisassembler::Fail;
3374     break;
3375   case ARM::VLD2DUPd16x2: case ARM::VLD2DUPd32x2: case ARM::VLD2DUPd8x2:
3376   case ARM::VLD2DUPd16x2wb_fixed: case ARM::VLD2DUPd16x2wb_register:
3377   case ARM::VLD2DUPd32x2wb_fixed: case ARM::VLD2DUPd32x2wb_register:
3378   case ARM::VLD2DUPd8x2wb_fixed: case ARM::VLD2DUPd8x2wb_register:
3379     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
3380       return MCDisassembler::Fail;
3381     break;
3382   default:
3383     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3384       return MCDisassembler::Fail;
3385     break;
3386   }
3387 
3388   if (Rm != 0xF)
3389     Inst.addOperand(MCOperand::createImm(0));
3390 
3391   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3392     return MCDisassembler::Fail;
3393   Inst.addOperand(MCOperand::createImm(align));
3394 
3395   if (Rm != 0xD && Rm != 0xF) {
3396     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3397       return MCDisassembler::Fail;
3398   }
3399 
3400   return S;
3401 }
3402 
3403 static DecodeStatus DecodeVLD3DupInstruction(MCInst &Inst, unsigned Insn,
3404                                     uint64_t Address, const void *Decoder) {
3405   DecodeStatus S = MCDisassembler::Success;
3406 
3407   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3408   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3409   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3410   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3411   unsigned inc = fieldFromInstruction(Insn, 5, 1) + 1;
3412 
3413   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3414     return MCDisassembler::Fail;
3415   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
3416     return MCDisassembler::Fail;
3417   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
3418     return MCDisassembler::Fail;
3419   if (Rm != 0xF) {
3420     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3421       return MCDisassembler::Fail;
3422   }
3423 
3424   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3425     return MCDisassembler::Fail;
3426   Inst.addOperand(MCOperand::createImm(0));
3427 
3428   if (Rm == 0xD)
3429     Inst.addOperand(MCOperand::createReg(0));
3430   else if (Rm != 0xF) {
3431     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3432       return MCDisassembler::Fail;
3433   }
3434 
3435   return S;
3436 }
3437 
3438 static DecodeStatus DecodeVLD4DupInstruction(MCInst &Inst, unsigned Insn,
3439                                     uint64_t Address, const void *Decoder) {
3440   DecodeStatus S = MCDisassembler::Success;
3441 
3442   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3443   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3444   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3445   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3446   unsigned size = fieldFromInstruction(Insn, 6, 2);
3447   unsigned inc = fieldFromInstruction(Insn, 5, 1) + 1;
3448   unsigned align = fieldFromInstruction(Insn, 4, 1);
3449 
3450   if (size == 0x3) {
3451     if (align == 0)
3452       return MCDisassembler::Fail;
3453     align = 16;
3454   } else {
3455     if (size == 2) {
3456       align *= 8;
3457     } else {
3458       size = 1 << size;
3459       align *= 4*size;
3460     }
3461   }
3462 
3463   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3464     return MCDisassembler::Fail;
3465   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
3466     return MCDisassembler::Fail;
3467   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
3468     return MCDisassembler::Fail;
3469   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3*inc)%32, Address, Decoder)))
3470     return MCDisassembler::Fail;
3471   if (Rm != 0xF) {
3472     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3473       return MCDisassembler::Fail;
3474   }
3475 
3476   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3477     return MCDisassembler::Fail;
3478   Inst.addOperand(MCOperand::createImm(align));
3479 
3480   if (Rm == 0xD)
3481     Inst.addOperand(MCOperand::createReg(0));
3482   else if (Rm != 0xF) {
3483     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3484       return MCDisassembler::Fail;
3485   }
3486 
3487   return S;
3488 }
3489 
3490 static DecodeStatus
3491 DecodeVMOVModImmInstruction(MCInst &Inst, unsigned Insn,
3492                             uint64_t Address, const void *Decoder) {
3493   DecodeStatus S = MCDisassembler::Success;
3494 
3495   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3496   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3497   unsigned imm = fieldFromInstruction(Insn, 0, 4);
3498   imm |= fieldFromInstruction(Insn, 16, 3) << 4;
3499   imm |= fieldFromInstruction(Insn, 24, 1) << 7;
3500   imm |= fieldFromInstruction(Insn, 8, 4) << 8;
3501   imm |= fieldFromInstruction(Insn, 5, 1) << 12;
3502   unsigned Q = fieldFromInstruction(Insn, 6, 1);
3503 
3504   if (Q) {
3505     if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3506     return MCDisassembler::Fail;
3507   } else {
3508     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3509     return MCDisassembler::Fail;
3510   }
3511 
3512   Inst.addOperand(MCOperand::createImm(imm));
3513 
3514   switch (Inst.getOpcode()) {
3515     case ARM::VORRiv4i16:
3516     case ARM::VORRiv2i32:
3517     case ARM::VBICiv4i16:
3518     case ARM::VBICiv2i32:
3519       if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3520         return MCDisassembler::Fail;
3521       break;
3522     case ARM::VORRiv8i16:
3523     case ARM::VORRiv4i32:
3524     case ARM::VBICiv8i16:
3525     case ARM::VBICiv4i32:
3526       if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3527         return MCDisassembler::Fail;
3528       break;
3529     default:
3530       break;
3531   }
3532 
3533   return S;
3534 }
3535 
3536 static DecodeStatus
3537 DecodeMVEModImmInstruction(MCInst &Inst, unsigned Insn,
3538                            uint64_t Address, const void *Decoder) {
3539   DecodeStatus S = MCDisassembler::Success;
3540 
3541   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
3542                  fieldFromInstruction(Insn, 13, 3));
3543   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
3544   unsigned imm = fieldFromInstruction(Insn, 0, 4);
3545   imm |= fieldFromInstruction(Insn, 16, 3) << 4;
3546   imm |= fieldFromInstruction(Insn, 28, 1) << 7;
3547   imm |= cmode                             << 8;
3548   imm |= fieldFromInstruction(Insn, 5, 1)  << 12;
3549 
3550   if (cmode == 0xF && Inst.getOpcode() == ARM::MVE_VMVNimmi32)
3551     return MCDisassembler::Fail;
3552 
3553   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
3554     return MCDisassembler::Fail;
3555 
3556   Inst.addOperand(MCOperand::createImm(imm));
3557 
3558   Inst.addOperand(MCOperand::createImm(ARMVCC::None));
3559   Inst.addOperand(MCOperand::createReg(0));
3560   Inst.addOperand(MCOperand::createImm(0));
3561 
3562   return S;
3563 }
3564 
3565 static DecodeStatus DecodeMVEVADCInstruction(MCInst &Inst, unsigned Insn,
3566                                uint64_t Address, const void *Decoder) {
3567   DecodeStatus S = MCDisassembler::Success;
3568 
3569   unsigned Qd = fieldFromInstruction(Insn, 13, 3);
3570   Qd |= fieldFromInstruction(Insn, 22, 1) << 3;
3571   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
3572     return MCDisassembler::Fail;
3573   Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
3574 
3575   unsigned Qn = fieldFromInstruction(Insn, 17, 3);
3576   Qn |= fieldFromInstruction(Insn, 7, 1) << 3;
3577   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qn, Address, Decoder)))
3578     return MCDisassembler::Fail;
3579   unsigned Qm = fieldFromInstruction(Insn, 1, 3);
3580   Qm |= fieldFromInstruction(Insn, 5, 1) << 3;
3581   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
3582     return MCDisassembler::Fail;
3583   if (!fieldFromInstruction(Insn, 12, 1)) // I bit clear => need input FPSCR
3584     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
3585   Inst.addOperand(MCOperand::createImm(Qd));
3586 
3587   return S;
3588 }
3589 
3590 static DecodeStatus DecodeVSHLMaxInstruction(MCInst &Inst, unsigned Insn,
3591                                         uint64_t Address, const void *Decoder) {
3592   DecodeStatus S = MCDisassembler::Success;
3593 
3594   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3595   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3596   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3597   Rm |= fieldFromInstruction(Insn, 5, 1) << 4;
3598   unsigned size = fieldFromInstruction(Insn, 18, 2);
3599 
3600   if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3601     return MCDisassembler::Fail;
3602   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
3603     return MCDisassembler::Fail;
3604   Inst.addOperand(MCOperand::createImm(8 << size));
3605 
3606   return S;
3607 }
3608 
3609 static DecodeStatus DecodeShiftRight8Imm(MCInst &Inst, unsigned Val,
3610                                uint64_t Address, const void *Decoder) {
3611   Inst.addOperand(MCOperand::createImm(8 - Val));
3612   return MCDisassembler::Success;
3613 }
3614 
3615 static DecodeStatus DecodeShiftRight16Imm(MCInst &Inst, unsigned Val,
3616                                uint64_t Address, const void *Decoder) {
3617   Inst.addOperand(MCOperand::createImm(16 - Val));
3618   return MCDisassembler::Success;
3619 }
3620 
3621 static DecodeStatus DecodeShiftRight32Imm(MCInst &Inst, unsigned Val,
3622                                uint64_t Address, const void *Decoder) {
3623   Inst.addOperand(MCOperand::createImm(32 - Val));
3624   return MCDisassembler::Success;
3625 }
3626 
3627 static DecodeStatus DecodeShiftRight64Imm(MCInst &Inst, unsigned Val,
3628                                uint64_t Address, const void *Decoder) {
3629   Inst.addOperand(MCOperand::createImm(64 - Val));
3630   return MCDisassembler::Success;
3631 }
3632 
3633 static DecodeStatus DecodeTBLInstruction(MCInst &Inst, unsigned Insn,
3634                                uint64_t Address, const void *Decoder) {
3635   DecodeStatus S = MCDisassembler::Success;
3636 
3637   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3638   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3639   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3640   Rn |= fieldFromInstruction(Insn, 7, 1) << 4;
3641   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3642   Rm |= fieldFromInstruction(Insn, 5, 1) << 4;
3643   unsigned op = fieldFromInstruction(Insn, 6, 1);
3644 
3645   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3646     return MCDisassembler::Fail;
3647   if (op) {
3648     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3649     return MCDisassembler::Fail; // Writeback
3650   }
3651 
3652   switch (Inst.getOpcode()) {
3653   case ARM::VTBL2:
3654   case ARM::VTBX2:
3655     if (!Check(S, DecodeDPairRegisterClass(Inst, Rn, Address, Decoder)))
3656       return MCDisassembler::Fail;
3657     break;
3658   default:
3659     if (!Check(S, DecodeDPRRegisterClass(Inst, Rn, Address, Decoder)))
3660       return MCDisassembler::Fail;
3661   }
3662 
3663   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
3664     return MCDisassembler::Fail;
3665 
3666   return S;
3667 }
3668 
3669 static DecodeStatus DecodeThumbAddSpecialReg(MCInst &Inst, uint16_t Insn,
3670                                      uint64_t Address, const void *Decoder) {
3671   DecodeStatus S = MCDisassembler::Success;
3672 
3673   unsigned dst = fieldFromInstruction(Insn, 8, 3);
3674   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3675 
3676   if (!Check(S, DecodetGPRRegisterClass(Inst, dst, Address, Decoder)))
3677     return MCDisassembler::Fail;
3678 
3679   switch(Inst.getOpcode()) {
3680     default:
3681       return MCDisassembler::Fail;
3682     case ARM::tADR:
3683       break; // tADR does not explicitly represent the PC as an operand.
3684     case ARM::tADDrSPi:
3685       Inst.addOperand(MCOperand::createReg(ARM::SP));
3686       break;
3687   }
3688 
3689   Inst.addOperand(MCOperand::createImm(imm));
3690   return S;
3691 }
3692 
3693 static DecodeStatus DecodeThumbBROperand(MCInst &Inst, unsigned Val,
3694                                  uint64_t Address, const void *Decoder) {
3695   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<12>(Val<<1) + 4,
3696                                 true, 2, Inst, Decoder))
3697     Inst.addOperand(MCOperand::createImm(SignExtend32<12>(Val << 1)));
3698   return MCDisassembler::Success;
3699 }
3700 
3701 static DecodeStatus DecodeT2BROperand(MCInst &Inst, unsigned Val,
3702                                  uint64_t Address, const void *Decoder) {
3703   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<21>(Val) + 4,
3704                                 true, 4, Inst, Decoder))
3705     Inst.addOperand(MCOperand::createImm(SignExtend32<21>(Val)));
3706   return MCDisassembler::Success;
3707 }
3708 
3709 static DecodeStatus DecodeThumbCmpBROperand(MCInst &Inst, unsigned Val,
3710                                  uint64_t Address, const void *Decoder) {
3711   if (!tryAddingSymbolicOperand(Address, Address + (Val<<1) + 4,
3712                                 true, 2, Inst, Decoder))
3713     Inst.addOperand(MCOperand::createImm(Val << 1));
3714   return MCDisassembler::Success;
3715 }
3716 
3717 static DecodeStatus DecodeThumbAddrModeRR(MCInst &Inst, unsigned Val,
3718                                  uint64_t Address, const void *Decoder) {
3719   DecodeStatus S = MCDisassembler::Success;
3720 
3721   unsigned Rn = fieldFromInstruction(Val, 0, 3);
3722   unsigned Rm = fieldFromInstruction(Val, 3, 3);
3723 
3724   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
3725     return MCDisassembler::Fail;
3726   if (!Check(S, DecodetGPRRegisterClass(Inst, Rm, Address, Decoder)))
3727     return MCDisassembler::Fail;
3728 
3729   return S;
3730 }
3731 
3732 static DecodeStatus DecodeThumbAddrModeIS(MCInst &Inst, unsigned Val,
3733                                   uint64_t Address, const void *Decoder) {
3734   DecodeStatus S = MCDisassembler::Success;
3735 
3736   unsigned Rn = fieldFromInstruction(Val, 0, 3);
3737   unsigned imm = fieldFromInstruction(Val, 3, 5);
3738 
3739   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
3740     return MCDisassembler::Fail;
3741   Inst.addOperand(MCOperand::createImm(imm));
3742 
3743   return S;
3744 }
3745 
3746 static DecodeStatus DecodeThumbAddrModePC(MCInst &Inst, unsigned Val,
3747                                   uint64_t Address, const void *Decoder) {
3748   unsigned imm = Val << 2;
3749 
3750   Inst.addOperand(MCOperand::createImm(imm));
3751   tryAddingPcLoadReferenceComment(Address, (Address & ~2u) + imm + 4, Decoder);
3752 
3753   return MCDisassembler::Success;
3754 }
3755 
3756 static DecodeStatus DecodeThumbAddrModeSP(MCInst &Inst, unsigned Val,
3757                                   uint64_t Address, const void *Decoder) {
3758   Inst.addOperand(MCOperand::createReg(ARM::SP));
3759   Inst.addOperand(MCOperand::createImm(Val));
3760 
3761   return MCDisassembler::Success;
3762 }
3763 
3764 static DecodeStatus DecodeT2AddrModeSOReg(MCInst &Inst, unsigned Val,
3765                                   uint64_t Address, const void *Decoder) {
3766   DecodeStatus S = MCDisassembler::Success;
3767 
3768   unsigned Rn = fieldFromInstruction(Val, 6, 4);
3769   unsigned Rm = fieldFromInstruction(Val, 2, 4);
3770   unsigned imm = fieldFromInstruction(Val, 0, 2);
3771 
3772   // Thumb stores cannot use PC as dest register.
3773   switch (Inst.getOpcode()) {
3774   case ARM::t2STRHs:
3775   case ARM::t2STRBs:
3776   case ARM::t2STRs:
3777     if (Rn == 15)
3778       return MCDisassembler::Fail;
3779     break;
3780   default:
3781     break;
3782   }
3783 
3784   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3785     return MCDisassembler::Fail;
3786   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
3787     return MCDisassembler::Fail;
3788   Inst.addOperand(MCOperand::createImm(imm));
3789 
3790   return S;
3791 }
3792 
3793 static DecodeStatus DecodeT2LoadShift(MCInst &Inst, unsigned Insn,
3794                               uint64_t Address, const void *Decoder) {
3795   DecodeStatus S = MCDisassembler::Success;
3796 
3797   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3798   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3799 
3800   const FeatureBitset &featureBits =
3801     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3802 
3803   bool hasMP = featureBits[ARM::FeatureMP];
3804   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3805 
3806   if (Rn == 15) {
3807     switch (Inst.getOpcode()) {
3808     case ARM::t2LDRBs:
3809       Inst.setOpcode(ARM::t2LDRBpci);
3810       break;
3811     case ARM::t2LDRHs:
3812       Inst.setOpcode(ARM::t2LDRHpci);
3813       break;
3814     case ARM::t2LDRSHs:
3815       Inst.setOpcode(ARM::t2LDRSHpci);
3816       break;
3817     case ARM::t2LDRSBs:
3818       Inst.setOpcode(ARM::t2LDRSBpci);
3819       break;
3820     case ARM::t2LDRs:
3821       Inst.setOpcode(ARM::t2LDRpci);
3822       break;
3823     case ARM::t2PLDs:
3824       Inst.setOpcode(ARM::t2PLDpci);
3825       break;
3826     case ARM::t2PLIs:
3827       Inst.setOpcode(ARM::t2PLIpci);
3828       break;
3829     default:
3830       return MCDisassembler::Fail;
3831     }
3832 
3833     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3834   }
3835 
3836   if (Rt == 15) {
3837     switch (Inst.getOpcode()) {
3838     case ARM::t2LDRSHs:
3839       return MCDisassembler::Fail;
3840     case ARM::t2LDRHs:
3841       Inst.setOpcode(ARM::t2PLDWs);
3842       break;
3843     case ARM::t2LDRSBs:
3844       Inst.setOpcode(ARM::t2PLIs);
3845       break;
3846     default:
3847       break;
3848     }
3849   }
3850 
3851   switch (Inst.getOpcode()) {
3852     case ARM::t2PLDs:
3853       break;
3854     case ARM::t2PLIs:
3855       if (!hasV7Ops)
3856         return MCDisassembler::Fail;
3857       break;
3858     case ARM::t2PLDWs:
3859       if (!hasV7Ops || !hasMP)
3860         return MCDisassembler::Fail;
3861       break;
3862     default:
3863       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3864         return MCDisassembler::Fail;
3865   }
3866 
3867   unsigned addrmode = fieldFromInstruction(Insn, 4, 2);
3868   addrmode |= fieldFromInstruction(Insn, 0, 4) << 2;
3869   addrmode |= fieldFromInstruction(Insn, 16, 4) << 6;
3870   if (!Check(S, DecodeT2AddrModeSOReg(Inst, addrmode, Address, Decoder)))
3871     return MCDisassembler::Fail;
3872 
3873   return S;
3874 }
3875 
3876 static DecodeStatus DecodeT2LoadImm8(MCInst &Inst, unsigned Insn,
3877                                 uint64_t Address, const void* Decoder) {
3878   DecodeStatus S = MCDisassembler::Success;
3879 
3880   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3881   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3882   unsigned U = fieldFromInstruction(Insn, 9, 1);
3883   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3884   imm |= (U << 8);
3885   imm |= (Rn << 9);
3886   unsigned add = fieldFromInstruction(Insn, 9, 1);
3887 
3888   const FeatureBitset &featureBits =
3889     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3890 
3891   bool hasMP = featureBits[ARM::FeatureMP];
3892   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3893 
3894   if (Rn == 15) {
3895     switch (Inst.getOpcode()) {
3896     case ARM::t2LDRi8:
3897       Inst.setOpcode(ARM::t2LDRpci);
3898       break;
3899     case ARM::t2LDRBi8:
3900       Inst.setOpcode(ARM::t2LDRBpci);
3901       break;
3902     case ARM::t2LDRSBi8:
3903       Inst.setOpcode(ARM::t2LDRSBpci);
3904       break;
3905     case ARM::t2LDRHi8:
3906       Inst.setOpcode(ARM::t2LDRHpci);
3907       break;
3908     case ARM::t2LDRSHi8:
3909       Inst.setOpcode(ARM::t2LDRSHpci);
3910       break;
3911     case ARM::t2PLDi8:
3912       Inst.setOpcode(ARM::t2PLDpci);
3913       break;
3914     case ARM::t2PLIi8:
3915       Inst.setOpcode(ARM::t2PLIpci);
3916       break;
3917     default:
3918       return MCDisassembler::Fail;
3919     }
3920     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3921   }
3922 
3923   if (Rt == 15) {
3924     switch (Inst.getOpcode()) {
3925     case ARM::t2LDRSHi8:
3926       return MCDisassembler::Fail;
3927     case ARM::t2LDRHi8:
3928       if (!add)
3929         Inst.setOpcode(ARM::t2PLDWi8);
3930       break;
3931     case ARM::t2LDRSBi8:
3932       Inst.setOpcode(ARM::t2PLIi8);
3933       break;
3934     default:
3935       break;
3936     }
3937   }
3938 
3939   switch (Inst.getOpcode()) {
3940   case ARM::t2PLDi8:
3941     break;
3942   case ARM::t2PLIi8:
3943     if (!hasV7Ops)
3944       return MCDisassembler::Fail;
3945     break;
3946   case ARM::t2PLDWi8:
3947       if (!hasV7Ops || !hasMP)
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 (!Check(S, DecodeT2AddrModeImm8(Inst, imm, Address, Decoder)))
3956     return MCDisassembler::Fail;
3957   return S;
3958 }
3959 
3960 static DecodeStatus DecodeT2LoadImm12(MCInst &Inst, unsigned Insn,
3961                                 uint64_t Address, const void* Decoder) {
3962   DecodeStatus S = MCDisassembler::Success;
3963 
3964   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3965   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3966   unsigned imm = fieldFromInstruction(Insn, 0, 12);
3967   imm |= (Rn << 13);
3968 
3969   const FeatureBitset &featureBits =
3970     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3971 
3972   bool hasMP = featureBits[ARM::FeatureMP];
3973   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3974 
3975   if (Rn == 15) {
3976     switch (Inst.getOpcode()) {
3977     case ARM::t2LDRi12:
3978       Inst.setOpcode(ARM::t2LDRpci);
3979       break;
3980     case ARM::t2LDRHi12:
3981       Inst.setOpcode(ARM::t2LDRHpci);
3982       break;
3983     case ARM::t2LDRSHi12:
3984       Inst.setOpcode(ARM::t2LDRSHpci);
3985       break;
3986     case ARM::t2LDRBi12:
3987       Inst.setOpcode(ARM::t2LDRBpci);
3988       break;
3989     case ARM::t2LDRSBi12:
3990       Inst.setOpcode(ARM::t2LDRSBpci);
3991       break;
3992     case ARM::t2PLDi12:
3993       Inst.setOpcode(ARM::t2PLDpci);
3994       break;
3995     case ARM::t2PLIi12:
3996       Inst.setOpcode(ARM::t2PLIpci);
3997       break;
3998     default:
3999       return MCDisassembler::Fail;
4000     }
4001     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
4002   }
4003 
4004   if (Rt == 15) {
4005     switch (Inst.getOpcode()) {
4006     case ARM::t2LDRSHi12:
4007       return MCDisassembler::Fail;
4008     case ARM::t2LDRHi12:
4009       Inst.setOpcode(ARM::t2PLDWi12);
4010       break;
4011     case ARM::t2LDRSBi12:
4012       Inst.setOpcode(ARM::t2PLIi12);
4013       break;
4014     default:
4015       break;
4016     }
4017   }
4018 
4019   switch (Inst.getOpcode()) {
4020   case ARM::t2PLDi12:
4021     break;
4022   case ARM::t2PLIi12:
4023     if (!hasV7Ops)
4024       return MCDisassembler::Fail;
4025     break;
4026   case ARM::t2PLDWi12:
4027       if (!hasV7Ops || !hasMP)
4028         return MCDisassembler::Fail;
4029       break;
4030   default:
4031     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4032       return MCDisassembler::Fail;
4033   }
4034 
4035   if (!Check(S, DecodeT2AddrModeImm12(Inst, imm, Address, Decoder)))
4036     return MCDisassembler::Fail;
4037   return S;
4038 }
4039 
4040 static DecodeStatus DecodeT2LoadT(MCInst &Inst, unsigned Insn,
4041                                 uint64_t Address, const void* Decoder) {
4042   DecodeStatus S = MCDisassembler::Success;
4043 
4044   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4045   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4046   unsigned imm = fieldFromInstruction(Insn, 0, 8);
4047   imm |= (Rn << 9);
4048 
4049   if (Rn == 15) {
4050     switch (Inst.getOpcode()) {
4051     case ARM::t2LDRT:
4052       Inst.setOpcode(ARM::t2LDRpci);
4053       break;
4054     case ARM::t2LDRBT:
4055       Inst.setOpcode(ARM::t2LDRBpci);
4056       break;
4057     case ARM::t2LDRHT:
4058       Inst.setOpcode(ARM::t2LDRHpci);
4059       break;
4060     case ARM::t2LDRSBT:
4061       Inst.setOpcode(ARM::t2LDRSBpci);
4062       break;
4063     case ARM::t2LDRSHT:
4064       Inst.setOpcode(ARM::t2LDRSHpci);
4065       break;
4066     default:
4067       return MCDisassembler::Fail;
4068     }
4069     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
4070   }
4071 
4072   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
4073     return MCDisassembler::Fail;
4074   if (!Check(S, DecodeT2AddrModeImm8(Inst, imm, Address, Decoder)))
4075     return MCDisassembler::Fail;
4076   return S;
4077 }
4078 
4079 static DecodeStatus DecodeT2LoadLabel(MCInst &Inst, unsigned Insn,
4080                                 uint64_t Address, const void* Decoder) {
4081   DecodeStatus S = MCDisassembler::Success;
4082 
4083   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4084   unsigned U = fieldFromInstruction(Insn, 23, 1);
4085   int imm = fieldFromInstruction(Insn, 0, 12);
4086 
4087   const FeatureBitset &featureBits =
4088     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4089 
4090   bool hasV7Ops = featureBits[ARM::HasV7Ops];
4091 
4092   if (Rt == 15) {
4093     switch (Inst.getOpcode()) {
4094       case ARM::t2LDRBpci:
4095       case ARM::t2LDRHpci:
4096         Inst.setOpcode(ARM::t2PLDpci);
4097         break;
4098       case ARM::t2LDRSBpci:
4099         Inst.setOpcode(ARM::t2PLIpci);
4100         break;
4101       case ARM::t2LDRSHpci:
4102         return MCDisassembler::Fail;
4103       default:
4104         break;
4105     }
4106   }
4107 
4108   switch(Inst.getOpcode()) {
4109   case ARM::t2PLDpci:
4110     break;
4111   case ARM::t2PLIpci:
4112     if (!hasV7Ops)
4113       return MCDisassembler::Fail;
4114     break;
4115   default:
4116     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4117       return MCDisassembler::Fail;
4118   }
4119 
4120   if (!U) {
4121     // Special case for #-0.
4122     if (imm == 0)
4123       imm = INT32_MIN;
4124     else
4125       imm = -imm;
4126   }
4127   Inst.addOperand(MCOperand::createImm(imm));
4128 
4129   return S;
4130 }
4131 
4132 static DecodeStatus DecodeT2Imm8S4(MCInst &Inst, unsigned Val,
4133                            uint64_t Address, const void *Decoder) {
4134   if (Val == 0)
4135     Inst.addOperand(MCOperand::createImm(INT32_MIN));
4136   else {
4137     int imm = Val & 0xFF;
4138 
4139     if (!(Val & 0x100)) imm *= -1;
4140     Inst.addOperand(MCOperand::createImm(imm * 4));
4141   }
4142 
4143   return MCDisassembler::Success;
4144 }
4145 
4146 static DecodeStatus DecodeT2Imm7S4(MCInst &Inst, unsigned Val, uint64_t Address,
4147                                    const void *Decoder) {
4148   if (Val == 0)
4149     Inst.addOperand(MCOperand::createImm(INT32_MIN));
4150   else {
4151     int imm = Val & 0x7F;
4152 
4153     if (!(Val & 0x80))
4154       imm *= -1;
4155     Inst.addOperand(MCOperand::createImm(imm * 4));
4156   }
4157 
4158   return MCDisassembler::Success;
4159 }
4160 
4161 static DecodeStatus DecodeT2AddrModeImm8s4(MCInst &Inst, unsigned Val,
4162                                    uint64_t Address, const void *Decoder) {
4163   DecodeStatus S = MCDisassembler::Success;
4164 
4165   unsigned Rn = fieldFromInstruction(Val, 9, 4);
4166   unsigned imm = fieldFromInstruction(Val, 0, 9);
4167 
4168   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4169     return MCDisassembler::Fail;
4170   if (!Check(S, DecodeT2Imm8S4(Inst, imm, Address, Decoder)))
4171     return MCDisassembler::Fail;
4172 
4173   return S;
4174 }
4175 
4176 static DecodeStatus DecodeT2AddrModeImm7s4(MCInst &Inst, unsigned Val,
4177                                            uint64_t Address,
4178                                            const void *Decoder) {
4179   DecodeStatus S = MCDisassembler::Success;
4180 
4181   unsigned Rn = fieldFromInstruction(Val, 8, 4);
4182   unsigned imm = fieldFromInstruction(Val, 0, 8);
4183 
4184   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4185     return MCDisassembler::Fail;
4186   if (!Check(S, DecodeT2Imm7S4(Inst, imm, Address, Decoder)))
4187     return MCDisassembler::Fail;
4188 
4189   return S;
4190 }
4191 
4192 static DecodeStatus DecodeT2AddrModeImm0_1020s4(MCInst &Inst,unsigned Val,
4193                                    uint64_t Address, const void *Decoder) {
4194   DecodeStatus S = MCDisassembler::Success;
4195 
4196   unsigned Rn = fieldFromInstruction(Val, 8, 4);
4197   unsigned imm = fieldFromInstruction(Val, 0, 8);
4198 
4199   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4200     return MCDisassembler::Fail;
4201 
4202   Inst.addOperand(MCOperand::createImm(imm));
4203 
4204   return S;
4205 }
4206 
4207 static DecodeStatus DecodeT2Imm8(MCInst &Inst, unsigned Val,
4208                          uint64_t Address, const void *Decoder) {
4209   int imm = Val & 0xFF;
4210   if (Val == 0)
4211     imm = INT32_MIN;
4212   else if (!(Val & 0x100))
4213     imm *= -1;
4214   Inst.addOperand(MCOperand::createImm(imm));
4215 
4216   return MCDisassembler::Success;
4217 }
4218 
4219 template<int shift>
4220 static DecodeStatus DecodeT2Imm7(MCInst &Inst, unsigned Val,
4221                          uint64_t Address, const void *Decoder) {
4222   int imm = Val & 0x7F;
4223   if (Val == 0)
4224     imm = INT32_MIN;
4225   else if (!(Val & 0x80))
4226     imm *= -1;
4227   if (imm != INT32_MIN)
4228     imm *= (1U << shift);
4229   Inst.addOperand(MCOperand::createImm(imm));
4230 
4231   return MCDisassembler::Success;
4232 }
4233 
4234 static DecodeStatus DecodeT2AddrModeImm8(MCInst &Inst, unsigned Val,
4235                                  uint64_t Address, const void *Decoder) {
4236   DecodeStatus S = MCDisassembler::Success;
4237 
4238   unsigned Rn = fieldFromInstruction(Val, 9, 4);
4239   unsigned imm = fieldFromInstruction(Val, 0, 9);
4240 
4241   // Thumb stores cannot use PC as dest register.
4242   switch (Inst.getOpcode()) {
4243   case ARM::t2STRT:
4244   case ARM::t2STRBT:
4245   case ARM::t2STRHT:
4246   case ARM::t2STRi8:
4247   case ARM::t2STRHi8:
4248   case ARM::t2STRBi8:
4249     if (Rn == 15)
4250       return MCDisassembler::Fail;
4251     break;
4252   default:
4253     break;
4254   }
4255 
4256   // Some instructions always use an additive offset.
4257   switch (Inst.getOpcode()) {
4258     case ARM::t2LDRT:
4259     case ARM::t2LDRBT:
4260     case ARM::t2LDRHT:
4261     case ARM::t2LDRSBT:
4262     case ARM::t2LDRSHT:
4263     case ARM::t2STRT:
4264     case ARM::t2STRBT:
4265     case ARM::t2STRHT:
4266       imm |= 0x100;
4267       break;
4268     default:
4269       break;
4270   }
4271 
4272   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4273     return MCDisassembler::Fail;
4274   if (!Check(S, DecodeT2Imm8(Inst, imm, Address, Decoder)))
4275     return MCDisassembler::Fail;
4276 
4277   return S;
4278 }
4279 
4280 template<int shift>
4281 static DecodeStatus DecodeTAddrModeImm7(MCInst &Inst, unsigned Val,
4282                                          uint64_t Address,
4283                                          const void *Decoder) {
4284   DecodeStatus S = MCDisassembler::Success;
4285 
4286   unsigned Rn = fieldFromInstruction(Val, 8, 3);
4287   unsigned imm = fieldFromInstruction(Val, 0, 8);
4288 
4289   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
4290     return MCDisassembler::Fail;
4291   if (!Check(S, DecodeT2Imm7<shift>(Inst, imm, Address, Decoder)))
4292     return MCDisassembler::Fail;
4293 
4294   return S;
4295 }
4296 
4297 template<int shift, int WriteBack>
4298 static DecodeStatus DecodeT2AddrModeImm7(MCInst &Inst, unsigned Val,
4299                                          uint64_t Address,
4300                                          const void *Decoder) {
4301   DecodeStatus S = MCDisassembler::Success;
4302 
4303   unsigned Rn = fieldFromInstruction(Val, 8, 4);
4304   unsigned imm = fieldFromInstruction(Val, 0, 8);
4305   if (WriteBack) {
4306     if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
4307       return MCDisassembler::Fail;
4308   } else if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4309     return MCDisassembler::Fail;
4310   if (!Check(S, DecodeT2Imm7<shift>(Inst, imm, Address, Decoder)))
4311     return MCDisassembler::Fail;
4312 
4313   return S;
4314 }
4315 
4316 static DecodeStatus DecodeT2LdStPre(MCInst &Inst, unsigned Insn,
4317                                     uint64_t Address, const void *Decoder) {
4318   DecodeStatus S = MCDisassembler::Success;
4319 
4320   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4321   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4322   unsigned addr = fieldFromInstruction(Insn, 0, 8);
4323   addr |= fieldFromInstruction(Insn, 9, 1) << 8;
4324   addr |= Rn << 9;
4325   unsigned load = fieldFromInstruction(Insn, 20, 1);
4326 
4327   if (Rn == 15) {
4328     switch (Inst.getOpcode()) {
4329     case ARM::t2LDR_PRE:
4330     case ARM::t2LDR_POST:
4331       Inst.setOpcode(ARM::t2LDRpci);
4332       break;
4333     case ARM::t2LDRB_PRE:
4334     case ARM::t2LDRB_POST:
4335       Inst.setOpcode(ARM::t2LDRBpci);
4336       break;
4337     case ARM::t2LDRH_PRE:
4338     case ARM::t2LDRH_POST:
4339       Inst.setOpcode(ARM::t2LDRHpci);
4340       break;
4341     case ARM::t2LDRSB_PRE:
4342     case ARM::t2LDRSB_POST:
4343       if (Rt == 15)
4344         Inst.setOpcode(ARM::t2PLIpci);
4345       else
4346         Inst.setOpcode(ARM::t2LDRSBpci);
4347       break;
4348     case ARM::t2LDRSH_PRE:
4349     case ARM::t2LDRSH_POST:
4350       Inst.setOpcode(ARM::t2LDRSHpci);
4351       break;
4352     default:
4353       return MCDisassembler::Fail;
4354     }
4355     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
4356   }
4357 
4358   if (!load) {
4359     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4360       return MCDisassembler::Fail;
4361   }
4362 
4363   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4364     return MCDisassembler::Fail;
4365 
4366   if (load) {
4367     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4368       return MCDisassembler::Fail;
4369   }
4370 
4371   if (!Check(S, DecodeT2AddrModeImm8(Inst, addr, Address, Decoder)))
4372     return MCDisassembler::Fail;
4373 
4374   return S;
4375 }
4376 
4377 static DecodeStatus DecodeT2AddrModeImm12(MCInst &Inst, unsigned Val,
4378                                   uint64_t Address, const void *Decoder) {
4379   DecodeStatus S = MCDisassembler::Success;
4380 
4381   unsigned Rn = fieldFromInstruction(Val, 13, 4);
4382   unsigned imm = fieldFromInstruction(Val, 0, 12);
4383 
4384   // Thumb stores cannot use PC as dest register.
4385   switch (Inst.getOpcode()) {
4386   case ARM::t2STRi12:
4387   case ARM::t2STRBi12:
4388   case ARM::t2STRHi12:
4389     if (Rn == 15)
4390       return MCDisassembler::Fail;
4391     break;
4392   default:
4393     break;
4394   }
4395 
4396   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4397     return MCDisassembler::Fail;
4398   Inst.addOperand(MCOperand::createImm(imm));
4399 
4400   return S;
4401 }
4402 
4403 static DecodeStatus DecodeThumbAddSPImm(MCInst &Inst, uint16_t Insn,
4404                                 uint64_t Address, const void *Decoder) {
4405   unsigned imm = fieldFromInstruction(Insn, 0, 7);
4406 
4407   Inst.addOperand(MCOperand::createReg(ARM::SP));
4408   Inst.addOperand(MCOperand::createReg(ARM::SP));
4409   Inst.addOperand(MCOperand::createImm(imm));
4410 
4411   return MCDisassembler::Success;
4412 }
4413 
4414 static DecodeStatus DecodeThumbAddSPReg(MCInst &Inst, uint16_t Insn,
4415                                 uint64_t Address, const void *Decoder) {
4416   DecodeStatus S = MCDisassembler::Success;
4417 
4418   if (Inst.getOpcode() == ARM::tADDrSP) {
4419     unsigned Rdm = fieldFromInstruction(Insn, 0, 3);
4420     Rdm |= fieldFromInstruction(Insn, 7, 1) << 3;
4421 
4422     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
4423     return MCDisassembler::Fail;
4424     Inst.addOperand(MCOperand::createReg(ARM::SP));
4425     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
4426     return MCDisassembler::Fail;
4427   } else if (Inst.getOpcode() == ARM::tADDspr) {
4428     unsigned Rm = fieldFromInstruction(Insn, 3, 4);
4429 
4430     Inst.addOperand(MCOperand::createReg(ARM::SP));
4431     Inst.addOperand(MCOperand::createReg(ARM::SP));
4432     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4433     return MCDisassembler::Fail;
4434   }
4435 
4436   return S;
4437 }
4438 
4439 static DecodeStatus DecodeThumbCPS(MCInst &Inst, uint16_t Insn,
4440                            uint64_t Address, const void *Decoder) {
4441   unsigned imod = fieldFromInstruction(Insn, 4, 1) | 0x2;
4442   unsigned flags = fieldFromInstruction(Insn, 0, 3);
4443 
4444   Inst.addOperand(MCOperand::createImm(imod));
4445   Inst.addOperand(MCOperand::createImm(flags));
4446 
4447   return MCDisassembler::Success;
4448 }
4449 
4450 static DecodeStatus DecodePostIdxReg(MCInst &Inst, unsigned Insn,
4451                              uint64_t Address, const void *Decoder) {
4452   DecodeStatus S = MCDisassembler::Success;
4453   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4454   unsigned add = fieldFromInstruction(Insn, 4, 1);
4455 
4456   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
4457     return MCDisassembler::Fail;
4458   Inst.addOperand(MCOperand::createImm(add));
4459 
4460   return S;
4461 }
4462 
4463 static DecodeStatus DecodeMveAddrModeRQ(MCInst &Inst, unsigned Insn,
4464                              uint64_t Address, const void *Decoder) {
4465   DecodeStatus S = MCDisassembler::Success;
4466   unsigned Rn = fieldFromInstruction(Insn, 3, 4);
4467   unsigned Qm = fieldFromInstruction(Insn, 0, 3);
4468 
4469   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4470     return MCDisassembler::Fail;
4471   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
4472     return MCDisassembler::Fail;
4473 
4474   return S;
4475 }
4476 
4477 template<int shift>
4478 static DecodeStatus DecodeMveAddrModeQ(MCInst &Inst, unsigned Insn,
4479                              uint64_t Address, const void *Decoder) {
4480   DecodeStatus S = MCDisassembler::Success;
4481   unsigned Qm = fieldFromInstruction(Insn, 8, 3);
4482   int imm = fieldFromInstruction(Insn, 0, 7);
4483 
4484   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
4485     return MCDisassembler::Fail;
4486 
4487   if(!fieldFromInstruction(Insn, 7, 1)) {
4488     if (imm == 0)
4489       imm = INT32_MIN;                 // indicate -0
4490     else
4491       imm *= -1;
4492   }
4493   if (imm != INT32_MIN)
4494     imm *= (1U << shift);
4495   Inst.addOperand(MCOperand::createImm(imm));
4496 
4497   return S;
4498 }
4499 
4500 static DecodeStatus DecodeThumbBLXOffset(MCInst &Inst, unsigned Val,
4501                                  uint64_t Address, const void *Decoder) {
4502   // Val is passed in as S:J1:J2:imm10H:imm10L:'0'
4503   // Note only one trailing zero not two.  Also the J1 and J2 values are from
4504   // the encoded instruction.  So here change to I1 and I2 values via:
4505   // I1 = NOT(J1 EOR S);
4506   // I2 = NOT(J2 EOR S);
4507   // and build the imm32 with two trailing zeros as documented:
4508   // imm32 = SignExtend(S:I1:I2:imm10H:imm10L:'00', 32);
4509   unsigned S = (Val >> 23) & 1;
4510   unsigned J1 = (Val >> 22) & 1;
4511   unsigned J2 = (Val >> 21) & 1;
4512   unsigned I1 = !(J1 ^ S);
4513   unsigned I2 = !(J2 ^ S);
4514   unsigned tmp = (Val & ~0x600000) | (I1 << 22) | (I2 << 21);
4515   int imm32 = SignExtend32<25>(tmp << 1);
4516 
4517   if (!tryAddingSymbolicOperand(Address,
4518                                 (Address & ~2u) + imm32 + 4,
4519                                 true, 4, Inst, Decoder))
4520     Inst.addOperand(MCOperand::createImm(imm32));
4521   return MCDisassembler::Success;
4522 }
4523 
4524 static DecodeStatus DecodeCoprocessor(MCInst &Inst, unsigned Val,
4525                               uint64_t Address, const void *Decoder) {
4526   if (Val == 0xA || Val == 0xB)
4527     return MCDisassembler::Fail;
4528 
4529   const FeatureBitset &featureBits =
4530     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4531 
4532   if (!isValidCoprocessorNumber(Val, featureBits))
4533     return MCDisassembler::Fail;
4534 
4535   Inst.addOperand(MCOperand::createImm(Val));
4536   return MCDisassembler::Success;
4537 }
4538 
4539 static DecodeStatus
4540 DecodeThumbTableBranch(MCInst &Inst, unsigned Insn,
4541                        uint64_t Address, const void *Decoder) {
4542   const FeatureBitset &FeatureBits =
4543     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4544   DecodeStatus S = MCDisassembler::Success;
4545 
4546   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4547   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4548 
4549   if (Rn == 13 && !FeatureBits[ARM::HasV8Ops]) S = MCDisassembler::SoftFail;
4550   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4551     return MCDisassembler::Fail;
4552   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
4553     return MCDisassembler::Fail;
4554   return S;
4555 }
4556 
4557 static DecodeStatus
4558 DecodeThumb2BCCInstruction(MCInst &Inst, unsigned Insn,
4559                            uint64_t Address, const void *Decoder) {
4560   DecodeStatus S = MCDisassembler::Success;
4561 
4562   unsigned pred = fieldFromInstruction(Insn, 22, 4);
4563   if (pred == 0xE || pred == 0xF) {
4564     unsigned opc = fieldFromInstruction(Insn, 4, 28);
4565     switch (opc) {
4566       default:
4567         return MCDisassembler::Fail;
4568       case 0xf3bf8f4:
4569         Inst.setOpcode(ARM::t2DSB);
4570         break;
4571       case 0xf3bf8f5:
4572         Inst.setOpcode(ARM::t2DMB);
4573         break;
4574       case 0xf3bf8f6:
4575         Inst.setOpcode(ARM::t2ISB);
4576         break;
4577     }
4578 
4579     unsigned imm = fieldFromInstruction(Insn, 0, 4);
4580     return DecodeMemBarrierOption(Inst, imm, Address, Decoder);
4581   }
4582 
4583   unsigned brtarget = fieldFromInstruction(Insn, 0, 11) << 1;
4584   brtarget |= fieldFromInstruction(Insn, 11, 1) << 19;
4585   brtarget |= fieldFromInstruction(Insn, 13, 1) << 18;
4586   brtarget |= fieldFromInstruction(Insn, 16, 6) << 12;
4587   brtarget |= fieldFromInstruction(Insn, 26, 1) << 20;
4588 
4589   if (!Check(S, DecodeT2BROperand(Inst, brtarget, Address, Decoder)))
4590     return MCDisassembler::Fail;
4591   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4592     return MCDisassembler::Fail;
4593 
4594   return S;
4595 }
4596 
4597 // Decode a shifted immediate operand.  These basically consist
4598 // of an 8-bit value, and a 4-bit directive that specifies either
4599 // a splat operation or a rotation.
4600 static DecodeStatus DecodeT2SOImm(MCInst &Inst, unsigned Val,
4601                           uint64_t Address, const void *Decoder) {
4602   unsigned ctrl = fieldFromInstruction(Val, 10, 2);
4603   if (ctrl == 0) {
4604     unsigned byte = fieldFromInstruction(Val, 8, 2);
4605     unsigned imm = fieldFromInstruction(Val, 0, 8);
4606     switch (byte) {
4607       case 0:
4608         Inst.addOperand(MCOperand::createImm(imm));
4609         break;
4610       case 1:
4611         Inst.addOperand(MCOperand::createImm((imm << 16) | imm));
4612         break;
4613       case 2:
4614         Inst.addOperand(MCOperand::createImm((imm << 24) | (imm << 8)));
4615         break;
4616       case 3:
4617         Inst.addOperand(MCOperand::createImm((imm << 24) | (imm << 16) |
4618                                              (imm << 8)  |  imm));
4619         break;
4620     }
4621   } else {
4622     unsigned unrot = fieldFromInstruction(Val, 0, 7) | 0x80;
4623     unsigned rot = fieldFromInstruction(Val, 7, 5);
4624     unsigned imm = (unrot >> rot) | (unrot << ((32-rot)&31));
4625     Inst.addOperand(MCOperand::createImm(imm));
4626   }
4627 
4628   return MCDisassembler::Success;
4629 }
4630 
4631 static DecodeStatus
4632 DecodeThumbBCCTargetOperand(MCInst &Inst, unsigned Val,
4633                             uint64_t Address, const void *Decoder) {
4634   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<9>(Val<<1) + 4,
4635                                 true, 2, Inst, Decoder))
4636     Inst.addOperand(MCOperand::createImm(SignExtend32<9>(Val << 1)));
4637   return MCDisassembler::Success;
4638 }
4639 
4640 static DecodeStatus DecodeThumbBLTargetOperand(MCInst &Inst, unsigned Val,
4641                                                uint64_t Address,
4642                                                const void *Decoder) {
4643   // Val is passed in as S:J1:J2:imm10:imm11
4644   // Note no trailing zero after imm11.  Also the J1 and J2 values are from
4645   // the encoded instruction.  So here change to I1 and I2 values via:
4646   // I1 = NOT(J1 EOR S);
4647   // I2 = NOT(J2 EOR S);
4648   // and build the imm32 with one trailing zero as documented:
4649   // imm32 = SignExtend(S:I1:I2:imm10:imm11:'0', 32);
4650   unsigned S = (Val >> 23) & 1;
4651   unsigned J1 = (Val >> 22) & 1;
4652   unsigned J2 = (Val >> 21) & 1;
4653   unsigned I1 = !(J1 ^ S);
4654   unsigned I2 = !(J2 ^ S);
4655   unsigned tmp = (Val & ~0x600000) | (I1 << 22) | (I2 << 21);
4656   int imm32 = SignExtend32<25>(tmp << 1);
4657 
4658   if (!tryAddingSymbolicOperand(Address, Address + imm32 + 4,
4659                                 true, 4, Inst, Decoder))
4660     Inst.addOperand(MCOperand::createImm(imm32));
4661   return MCDisassembler::Success;
4662 }
4663 
4664 static DecodeStatus DecodeMemBarrierOption(MCInst &Inst, unsigned Val,
4665                                    uint64_t Address, const void *Decoder) {
4666   if (Val & ~0xf)
4667     return MCDisassembler::Fail;
4668 
4669   Inst.addOperand(MCOperand::createImm(Val));
4670   return MCDisassembler::Success;
4671 }
4672 
4673 static DecodeStatus DecodeInstSyncBarrierOption(MCInst &Inst, unsigned Val,
4674                                         uint64_t Address, const void *Decoder) {
4675   if (Val & ~0xf)
4676     return MCDisassembler::Fail;
4677 
4678   Inst.addOperand(MCOperand::createImm(Val));
4679   return MCDisassembler::Success;
4680 }
4681 
4682 static DecodeStatus DecodeMSRMask(MCInst &Inst, unsigned Val,
4683                           uint64_t Address, const void *Decoder) {
4684   DecodeStatus S = MCDisassembler::Success;
4685   const FeatureBitset &FeatureBits =
4686     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4687 
4688   if (FeatureBits[ARM::FeatureMClass]) {
4689     unsigned ValLow = Val & 0xff;
4690 
4691     // Validate the SYSm value first.
4692     switch (ValLow) {
4693     case  0: // apsr
4694     case  1: // iapsr
4695     case  2: // eapsr
4696     case  3: // xpsr
4697     case  5: // ipsr
4698     case  6: // epsr
4699     case  7: // iepsr
4700     case  8: // msp
4701     case  9: // psp
4702     case 16: // primask
4703     case 20: // control
4704       break;
4705     case 17: // basepri
4706     case 18: // basepri_max
4707     case 19: // faultmask
4708       if (!(FeatureBits[ARM::HasV7Ops]))
4709         // Values basepri, basepri_max and faultmask are only valid for v7m.
4710         return MCDisassembler::Fail;
4711       break;
4712     case 0x8a: // msplim_ns
4713     case 0x8b: // psplim_ns
4714     case 0x91: // basepri_ns
4715     case 0x93: // faultmask_ns
4716       if (!(FeatureBits[ARM::HasV8MMainlineOps]))
4717         return MCDisassembler::Fail;
4718       LLVM_FALLTHROUGH;
4719     case 10:   // msplim
4720     case 11:   // psplim
4721     case 0x88: // msp_ns
4722     case 0x89: // psp_ns
4723     case 0x90: // primask_ns
4724     case 0x94: // control_ns
4725     case 0x98: // sp_ns
4726       if (!(FeatureBits[ARM::Feature8MSecExt]))
4727         return MCDisassembler::Fail;
4728       break;
4729     default:
4730       // Architecturally defined as unpredictable
4731       S = MCDisassembler::SoftFail;
4732       break;
4733     }
4734 
4735     if (Inst.getOpcode() == ARM::t2MSR_M) {
4736       unsigned Mask = fieldFromInstruction(Val, 10, 2);
4737       if (!(FeatureBits[ARM::HasV7Ops])) {
4738         // The ARMv6-M MSR bits {11-10} can be only 0b10, other values are
4739         // unpredictable.
4740         if (Mask != 2)
4741           S = MCDisassembler::SoftFail;
4742       }
4743       else {
4744         // The ARMv7-M architecture stores an additional 2-bit mask value in
4745         // MSR bits {11-10}. The mask is used only with apsr, iapsr, eapsr and
4746         // xpsr, it has to be 0b10 in other cases. Bit mask{1} indicates if
4747         // the NZCVQ bits should be moved by the instruction. Bit mask{0}
4748         // indicates the move for the GE{3:0} bits, the mask{0} bit can be set
4749         // only if the processor includes the DSP extension.
4750         if (Mask == 0 || (Mask != 2 && ValLow > 3) ||
4751             (!(FeatureBits[ARM::FeatureDSP]) && (Mask & 1)))
4752           S = MCDisassembler::SoftFail;
4753       }
4754     }
4755   } else {
4756     // A/R class
4757     if (Val == 0)
4758       return MCDisassembler::Fail;
4759   }
4760   Inst.addOperand(MCOperand::createImm(Val));
4761   return S;
4762 }
4763 
4764 static DecodeStatus DecodeBankedReg(MCInst &Inst, unsigned Val,
4765                                     uint64_t Address, const void *Decoder) {
4766   unsigned R = fieldFromInstruction(Val, 5, 1);
4767   unsigned SysM = fieldFromInstruction(Val, 0, 5);
4768 
4769   // The table of encodings for these banked registers comes from B9.2.3 of the
4770   // ARM ARM. There are patterns, but nothing regular enough to make this logic
4771   // neater. So by fiat, these values are UNPREDICTABLE:
4772   if (!ARMBankedReg::lookupBankedRegByEncoding((R << 5) | SysM))
4773     return MCDisassembler::Fail;
4774 
4775   Inst.addOperand(MCOperand::createImm(Val));
4776   return MCDisassembler::Success;
4777 }
4778 
4779 static DecodeStatus DecodeDoubleRegLoad(MCInst &Inst, unsigned Insn,
4780                                         uint64_t Address, const void *Decoder) {
4781   DecodeStatus S = MCDisassembler::Success;
4782 
4783   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4784   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4785   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4786 
4787   if (Rn == 0xF)
4788     S = MCDisassembler::SoftFail;
4789 
4790   if (!Check(S, DecodeGPRPairRegisterClass(Inst, Rt, Address, Decoder)))
4791     return MCDisassembler::Fail;
4792   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4793     return MCDisassembler::Fail;
4794   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4795     return MCDisassembler::Fail;
4796 
4797   return S;
4798 }
4799 
4800 static DecodeStatus DecodeDoubleRegStore(MCInst &Inst, unsigned Insn,
4801                                          uint64_t Address,
4802                                          const void *Decoder) {
4803   DecodeStatus S = MCDisassembler::Success;
4804 
4805   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4806   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
4807   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4808   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4809 
4810   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
4811     return MCDisassembler::Fail;
4812 
4813   if (Rn == 0xF || Rd == Rn || Rd == Rt || Rd == Rt+1)
4814     S = MCDisassembler::SoftFail;
4815 
4816   if (!Check(S, DecodeGPRPairRegisterClass(Inst, Rt, Address, Decoder)))
4817     return MCDisassembler::Fail;
4818   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4819     return MCDisassembler::Fail;
4820   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4821     return MCDisassembler::Fail;
4822 
4823   return S;
4824 }
4825 
4826 static DecodeStatus DecodeLDRPreImm(MCInst &Inst, unsigned Insn,
4827                             uint64_t Address, const void *Decoder) {
4828   DecodeStatus S = MCDisassembler::Success;
4829 
4830   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4831   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4832   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4833   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4834   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4835   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4836 
4837   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4838 
4839   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4840     return MCDisassembler::Fail;
4841   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4842     return MCDisassembler::Fail;
4843   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
4844     return MCDisassembler::Fail;
4845   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4846     return MCDisassembler::Fail;
4847 
4848   return S;
4849 }
4850 
4851 static DecodeStatus DecodeLDRPreReg(MCInst &Inst, unsigned Insn,
4852                             uint64_t Address, const void *Decoder) {
4853   DecodeStatus S = MCDisassembler::Success;
4854 
4855   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4856   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4857   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4858   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4859   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4860   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4861   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4862 
4863   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4864   if (Rm == 0xF) S = MCDisassembler::SoftFail;
4865 
4866   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4867     return MCDisassembler::Fail;
4868   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4869     return MCDisassembler::Fail;
4870   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
4871     return MCDisassembler::Fail;
4872   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4873     return MCDisassembler::Fail;
4874 
4875   return S;
4876 }
4877 
4878 static DecodeStatus DecodeSTRPreImm(MCInst &Inst, unsigned Insn,
4879                             uint64_t Address, const void *Decoder) {
4880   DecodeStatus S = MCDisassembler::Success;
4881 
4882   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4883   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4884   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4885   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4886   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4887   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4888 
4889   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4890 
4891   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4892     return MCDisassembler::Fail;
4893   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4894     return MCDisassembler::Fail;
4895   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
4896     return MCDisassembler::Fail;
4897   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4898     return MCDisassembler::Fail;
4899 
4900   return S;
4901 }
4902 
4903 static DecodeStatus DecodeSTRPreReg(MCInst &Inst, unsigned Insn,
4904                             uint64_t Address, const void *Decoder) {
4905   DecodeStatus S = MCDisassembler::Success;
4906 
4907   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4908   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4909   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4910   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4911   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4912   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4913 
4914   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4915 
4916   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4917     return MCDisassembler::Fail;
4918   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4919     return MCDisassembler::Fail;
4920   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
4921     return MCDisassembler::Fail;
4922   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4923     return MCDisassembler::Fail;
4924 
4925   return S;
4926 }
4927 
4928 static DecodeStatus DecodeVLD1LN(MCInst &Inst, unsigned Insn,
4929                          uint64_t Address, const void *Decoder) {
4930   DecodeStatus S = MCDisassembler::Success;
4931 
4932   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4933   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4934   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4935   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4936   unsigned size = fieldFromInstruction(Insn, 10, 2);
4937 
4938   unsigned align = 0;
4939   unsigned index = 0;
4940   switch (size) {
4941     default:
4942       return MCDisassembler::Fail;
4943     case 0:
4944       if (fieldFromInstruction(Insn, 4, 1))
4945         return MCDisassembler::Fail; // UNDEFINED
4946       index = fieldFromInstruction(Insn, 5, 3);
4947       break;
4948     case 1:
4949       if (fieldFromInstruction(Insn, 5, 1))
4950         return MCDisassembler::Fail; // UNDEFINED
4951       index = fieldFromInstruction(Insn, 6, 2);
4952       if (fieldFromInstruction(Insn, 4, 1))
4953         align = 2;
4954       break;
4955     case 2:
4956       if (fieldFromInstruction(Insn, 6, 1))
4957         return MCDisassembler::Fail; // UNDEFINED
4958       index = fieldFromInstruction(Insn, 7, 1);
4959 
4960       switch (fieldFromInstruction(Insn, 4, 2)) {
4961         case 0 :
4962           align = 0; break;
4963         case 3:
4964           align = 4; break;
4965         default:
4966           return MCDisassembler::Fail;
4967       }
4968       break;
4969   }
4970 
4971   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4972     return MCDisassembler::Fail;
4973   if (Rm != 0xF) { // Writeback
4974     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4975       return MCDisassembler::Fail;
4976   }
4977   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4978     return MCDisassembler::Fail;
4979   Inst.addOperand(MCOperand::createImm(align));
4980   if (Rm != 0xF) {
4981     if (Rm != 0xD) {
4982       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4983         return MCDisassembler::Fail;
4984     } else
4985       Inst.addOperand(MCOperand::createReg(0));
4986   }
4987 
4988   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4989     return MCDisassembler::Fail;
4990   Inst.addOperand(MCOperand::createImm(index));
4991 
4992   return S;
4993 }
4994 
4995 static DecodeStatus DecodeVST1LN(MCInst &Inst, unsigned Insn,
4996                          uint64_t Address, const void *Decoder) {
4997   DecodeStatus S = MCDisassembler::Success;
4998 
4999   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5000   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5001   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5002   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5003   unsigned size = fieldFromInstruction(Insn, 10, 2);
5004 
5005   unsigned align = 0;
5006   unsigned index = 0;
5007   switch (size) {
5008     default:
5009       return MCDisassembler::Fail;
5010     case 0:
5011       if (fieldFromInstruction(Insn, 4, 1))
5012         return MCDisassembler::Fail; // UNDEFINED
5013       index = fieldFromInstruction(Insn, 5, 3);
5014       break;
5015     case 1:
5016       if (fieldFromInstruction(Insn, 5, 1))
5017         return MCDisassembler::Fail; // UNDEFINED
5018       index = fieldFromInstruction(Insn, 6, 2);
5019       if (fieldFromInstruction(Insn, 4, 1))
5020         align = 2;
5021       break;
5022     case 2:
5023       if (fieldFromInstruction(Insn, 6, 1))
5024         return MCDisassembler::Fail; // UNDEFINED
5025       index = fieldFromInstruction(Insn, 7, 1);
5026 
5027       switch (fieldFromInstruction(Insn, 4, 2)) {
5028         case 0:
5029           align = 0; break;
5030         case 3:
5031           align = 4; break;
5032         default:
5033           return MCDisassembler::Fail;
5034       }
5035       break;
5036   }
5037 
5038   if (Rm != 0xF) { // Writeback
5039     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5040     return MCDisassembler::Fail;
5041   }
5042   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5043     return MCDisassembler::Fail;
5044   Inst.addOperand(MCOperand::createImm(align));
5045   if (Rm != 0xF) {
5046     if (Rm != 0xD) {
5047       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5048     return MCDisassembler::Fail;
5049     } else
5050       Inst.addOperand(MCOperand::createReg(0));
5051   }
5052 
5053   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5054     return MCDisassembler::Fail;
5055   Inst.addOperand(MCOperand::createImm(index));
5056 
5057   return S;
5058 }
5059 
5060 static DecodeStatus DecodeVLD2LN(MCInst &Inst, unsigned Insn,
5061                          uint64_t Address, const void *Decoder) {
5062   DecodeStatus S = MCDisassembler::Success;
5063 
5064   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5065   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5066   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5067   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5068   unsigned size = fieldFromInstruction(Insn, 10, 2);
5069 
5070   unsigned align = 0;
5071   unsigned index = 0;
5072   unsigned inc = 1;
5073   switch (size) {
5074     default:
5075       return MCDisassembler::Fail;
5076     case 0:
5077       index = fieldFromInstruction(Insn, 5, 3);
5078       if (fieldFromInstruction(Insn, 4, 1))
5079         align = 2;
5080       break;
5081     case 1:
5082       index = fieldFromInstruction(Insn, 6, 2);
5083       if (fieldFromInstruction(Insn, 4, 1))
5084         align = 4;
5085       if (fieldFromInstruction(Insn, 5, 1))
5086         inc = 2;
5087       break;
5088     case 2:
5089       if (fieldFromInstruction(Insn, 5, 1))
5090         return MCDisassembler::Fail; // UNDEFINED
5091       index = fieldFromInstruction(Insn, 7, 1);
5092       if (fieldFromInstruction(Insn, 4, 1) != 0)
5093         align = 8;
5094       if (fieldFromInstruction(Insn, 6, 1))
5095         inc = 2;
5096       break;
5097   }
5098 
5099   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5100     return MCDisassembler::Fail;
5101   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5102     return MCDisassembler::Fail;
5103   if (Rm != 0xF) { // Writeback
5104     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5105       return MCDisassembler::Fail;
5106   }
5107   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5108     return MCDisassembler::Fail;
5109   Inst.addOperand(MCOperand::createImm(align));
5110   if (Rm != 0xF) {
5111     if (Rm != 0xD) {
5112       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5113         return MCDisassembler::Fail;
5114     } else
5115       Inst.addOperand(MCOperand::createReg(0));
5116   }
5117 
5118   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5119     return MCDisassembler::Fail;
5120   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5121     return MCDisassembler::Fail;
5122   Inst.addOperand(MCOperand::createImm(index));
5123 
5124   return S;
5125 }
5126 
5127 static DecodeStatus DecodeVST2LN(MCInst &Inst, unsigned Insn,
5128                          uint64_t Address, const void *Decoder) {
5129   DecodeStatus S = MCDisassembler::Success;
5130 
5131   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5132   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5133   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5134   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5135   unsigned size = fieldFromInstruction(Insn, 10, 2);
5136 
5137   unsigned align = 0;
5138   unsigned index = 0;
5139   unsigned inc = 1;
5140   switch (size) {
5141     default:
5142       return MCDisassembler::Fail;
5143     case 0:
5144       index = fieldFromInstruction(Insn, 5, 3);
5145       if (fieldFromInstruction(Insn, 4, 1))
5146         align = 2;
5147       break;
5148     case 1:
5149       index = fieldFromInstruction(Insn, 6, 2);
5150       if (fieldFromInstruction(Insn, 4, 1))
5151         align = 4;
5152       if (fieldFromInstruction(Insn, 5, 1))
5153         inc = 2;
5154       break;
5155     case 2:
5156       if (fieldFromInstruction(Insn, 5, 1))
5157         return MCDisassembler::Fail; // UNDEFINED
5158       index = fieldFromInstruction(Insn, 7, 1);
5159       if (fieldFromInstruction(Insn, 4, 1) != 0)
5160         align = 8;
5161       if (fieldFromInstruction(Insn, 6, 1))
5162         inc = 2;
5163       break;
5164   }
5165 
5166   if (Rm != 0xF) { // Writeback
5167     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5168       return MCDisassembler::Fail;
5169   }
5170   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5171     return MCDisassembler::Fail;
5172   Inst.addOperand(MCOperand::createImm(align));
5173   if (Rm != 0xF) {
5174     if (Rm != 0xD) {
5175       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5176         return MCDisassembler::Fail;
5177     } else
5178       Inst.addOperand(MCOperand::createReg(0));
5179   }
5180 
5181   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5182     return MCDisassembler::Fail;
5183   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5184     return MCDisassembler::Fail;
5185   Inst.addOperand(MCOperand::createImm(index));
5186 
5187   return S;
5188 }
5189 
5190 static DecodeStatus DecodeVLD3LN(MCInst &Inst, unsigned Insn,
5191                          uint64_t Address, const void *Decoder) {
5192   DecodeStatus S = MCDisassembler::Success;
5193 
5194   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5195   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5196   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5197   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5198   unsigned size = fieldFromInstruction(Insn, 10, 2);
5199 
5200   unsigned align = 0;
5201   unsigned index = 0;
5202   unsigned inc = 1;
5203   switch (size) {
5204     default:
5205       return MCDisassembler::Fail;
5206     case 0:
5207       if (fieldFromInstruction(Insn, 4, 1))
5208         return MCDisassembler::Fail; // UNDEFINED
5209       index = fieldFromInstruction(Insn, 5, 3);
5210       break;
5211     case 1:
5212       if (fieldFromInstruction(Insn, 4, 1))
5213         return MCDisassembler::Fail; // UNDEFINED
5214       index = fieldFromInstruction(Insn, 6, 2);
5215       if (fieldFromInstruction(Insn, 5, 1))
5216         inc = 2;
5217       break;
5218     case 2:
5219       if (fieldFromInstruction(Insn, 4, 2))
5220         return MCDisassembler::Fail; // UNDEFINED
5221       index = fieldFromInstruction(Insn, 7, 1);
5222       if (fieldFromInstruction(Insn, 6, 1))
5223         inc = 2;
5224       break;
5225   }
5226 
5227   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5228     return MCDisassembler::Fail;
5229   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5230     return MCDisassembler::Fail;
5231   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5232     return MCDisassembler::Fail;
5233 
5234   if (Rm != 0xF) { // Writeback
5235     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5236     return MCDisassembler::Fail;
5237   }
5238   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5239     return MCDisassembler::Fail;
5240   Inst.addOperand(MCOperand::createImm(align));
5241   if (Rm != 0xF) {
5242     if (Rm != 0xD) {
5243       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5244     return MCDisassembler::Fail;
5245     } else
5246       Inst.addOperand(MCOperand::createReg(0));
5247   }
5248 
5249   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5250     return MCDisassembler::Fail;
5251   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5252     return MCDisassembler::Fail;
5253   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5254     return MCDisassembler::Fail;
5255   Inst.addOperand(MCOperand::createImm(index));
5256 
5257   return S;
5258 }
5259 
5260 static DecodeStatus DecodeVST3LN(MCInst &Inst, unsigned Insn,
5261                          uint64_t Address, const void *Decoder) {
5262   DecodeStatus S = MCDisassembler::Success;
5263 
5264   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5265   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5266   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5267   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5268   unsigned size = fieldFromInstruction(Insn, 10, 2);
5269 
5270   unsigned align = 0;
5271   unsigned index = 0;
5272   unsigned inc = 1;
5273   switch (size) {
5274     default:
5275       return MCDisassembler::Fail;
5276     case 0:
5277       if (fieldFromInstruction(Insn, 4, 1))
5278         return MCDisassembler::Fail; // UNDEFINED
5279       index = fieldFromInstruction(Insn, 5, 3);
5280       break;
5281     case 1:
5282       if (fieldFromInstruction(Insn, 4, 1))
5283         return MCDisassembler::Fail; // UNDEFINED
5284       index = fieldFromInstruction(Insn, 6, 2);
5285       if (fieldFromInstruction(Insn, 5, 1))
5286         inc = 2;
5287       break;
5288     case 2:
5289       if (fieldFromInstruction(Insn, 4, 2))
5290         return MCDisassembler::Fail; // UNDEFINED
5291       index = fieldFromInstruction(Insn, 7, 1);
5292       if (fieldFromInstruction(Insn, 6, 1))
5293         inc = 2;
5294       break;
5295   }
5296 
5297   if (Rm != 0xF) { // Writeback
5298     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5299     return MCDisassembler::Fail;
5300   }
5301   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5302     return MCDisassembler::Fail;
5303   Inst.addOperand(MCOperand::createImm(align));
5304   if (Rm != 0xF) {
5305     if (Rm != 0xD) {
5306       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5307     return MCDisassembler::Fail;
5308     } else
5309       Inst.addOperand(MCOperand::createReg(0));
5310   }
5311 
5312   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5313     return MCDisassembler::Fail;
5314   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5315     return MCDisassembler::Fail;
5316   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5317     return MCDisassembler::Fail;
5318   Inst.addOperand(MCOperand::createImm(index));
5319 
5320   return S;
5321 }
5322 
5323 static DecodeStatus DecodeVLD4LN(MCInst &Inst, unsigned Insn,
5324                          uint64_t Address, const void *Decoder) {
5325   DecodeStatus S = MCDisassembler::Success;
5326 
5327   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5328   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5329   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5330   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5331   unsigned size = fieldFromInstruction(Insn, 10, 2);
5332 
5333   unsigned align = 0;
5334   unsigned index = 0;
5335   unsigned inc = 1;
5336   switch (size) {
5337     default:
5338       return MCDisassembler::Fail;
5339     case 0:
5340       if (fieldFromInstruction(Insn, 4, 1))
5341         align = 4;
5342       index = fieldFromInstruction(Insn, 5, 3);
5343       break;
5344     case 1:
5345       if (fieldFromInstruction(Insn, 4, 1))
5346         align = 8;
5347       index = fieldFromInstruction(Insn, 6, 2);
5348       if (fieldFromInstruction(Insn, 5, 1))
5349         inc = 2;
5350       break;
5351     case 2:
5352       switch (fieldFromInstruction(Insn, 4, 2)) {
5353         case 0:
5354           align = 0; break;
5355         case 3:
5356           return MCDisassembler::Fail;
5357         default:
5358           align = 4 << fieldFromInstruction(Insn, 4, 2); break;
5359       }
5360 
5361       index = fieldFromInstruction(Insn, 7, 1);
5362       if (fieldFromInstruction(Insn, 6, 1))
5363         inc = 2;
5364       break;
5365   }
5366 
5367   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5368     return MCDisassembler::Fail;
5369   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5370     return MCDisassembler::Fail;
5371   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5372     return MCDisassembler::Fail;
5373   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5374     return MCDisassembler::Fail;
5375 
5376   if (Rm != 0xF) { // Writeback
5377     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5378       return MCDisassembler::Fail;
5379   }
5380   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5381     return MCDisassembler::Fail;
5382   Inst.addOperand(MCOperand::createImm(align));
5383   if (Rm != 0xF) {
5384     if (Rm != 0xD) {
5385       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5386         return MCDisassembler::Fail;
5387     } else
5388       Inst.addOperand(MCOperand::createReg(0));
5389   }
5390 
5391   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5392     return MCDisassembler::Fail;
5393   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5394     return MCDisassembler::Fail;
5395   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5396     return MCDisassembler::Fail;
5397   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5398     return MCDisassembler::Fail;
5399   Inst.addOperand(MCOperand::createImm(index));
5400 
5401   return S;
5402 }
5403 
5404 static DecodeStatus DecodeVST4LN(MCInst &Inst, unsigned Insn,
5405                          uint64_t Address, const void *Decoder) {
5406   DecodeStatus S = MCDisassembler::Success;
5407 
5408   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5409   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5410   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5411   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5412   unsigned size = fieldFromInstruction(Insn, 10, 2);
5413 
5414   unsigned align = 0;
5415   unsigned index = 0;
5416   unsigned inc = 1;
5417   switch (size) {
5418     default:
5419       return MCDisassembler::Fail;
5420     case 0:
5421       if (fieldFromInstruction(Insn, 4, 1))
5422         align = 4;
5423       index = fieldFromInstruction(Insn, 5, 3);
5424       break;
5425     case 1:
5426       if (fieldFromInstruction(Insn, 4, 1))
5427         align = 8;
5428       index = fieldFromInstruction(Insn, 6, 2);
5429       if (fieldFromInstruction(Insn, 5, 1))
5430         inc = 2;
5431       break;
5432     case 2:
5433       switch (fieldFromInstruction(Insn, 4, 2)) {
5434         case 0:
5435           align = 0; break;
5436         case 3:
5437           return MCDisassembler::Fail;
5438         default:
5439           align = 4 << fieldFromInstruction(Insn, 4, 2); break;
5440       }
5441 
5442       index = fieldFromInstruction(Insn, 7, 1);
5443       if (fieldFromInstruction(Insn, 6, 1))
5444         inc = 2;
5445       break;
5446   }
5447 
5448   if (Rm != 0xF) { // Writeback
5449     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5450     return MCDisassembler::Fail;
5451   }
5452   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5453     return MCDisassembler::Fail;
5454   Inst.addOperand(MCOperand::createImm(align));
5455   if (Rm != 0xF) {
5456     if (Rm != 0xD) {
5457       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5458     return MCDisassembler::Fail;
5459     } else
5460       Inst.addOperand(MCOperand::createReg(0));
5461   }
5462 
5463   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5464     return MCDisassembler::Fail;
5465   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5466     return MCDisassembler::Fail;
5467   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5468     return MCDisassembler::Fail;
5469   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5470     return MCDisassembler::Fail;
5471   Inst.addOperand(MCOperand::createImm(index));
5472 
5473   return S;
5474 }
5475 
5476 static DecodeStatus DecodeVMOVSRR(MCInst &Inst, unsigned Insn,
5477                                   uint64_t Address, const void *Decoder) {
5478   DecodeStatus S = MCDisassembler::Success;
5479   unsigned Rt  = fieldFromInstruction(Insn, 12, 4);
5480   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
5481   unsigned Rm  = fieldFromInstruction(Insn,  5, 1);
5482   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5483   Rm |= fieldFromInstruction(Insn, 0, 4) << 1;
5484 
5485   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
5486     S = MCDisassembler::SoftFail;
5487 
5488   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
5489     return MCDisassembler::Fail;
5490   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
5491     return MCDisassembler::Fail;
5492   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
5493     return MCDisassembler::Fail;
5494   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
5495     return MCDisassembler::Fail;
5496   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5497     return MCDisassembler::Fail;
5498 
5499   return S;
5500 }
5501 
5502 static DecodeStatus DecodeVMOVRRS(MCInst &Inst, unsigned Insn,
5503                                   uint64_t Address, const void *Decoder) {
5504   DecodeStatus S = MCDisassembler::Success;
5505   unsigned Rt  = fieldFromInstruction(Insn, 12, 4);
5506   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
5507   unsigned Rm  = fieldFromInstruction(Insn,  5, 1);
5508   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5509   Rm |= fieldFromInstruction(Insn, 0, 4) << 1;
5510 
5511   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
5512     S = MCDisassembler::SoftFail;
5513 
5514   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
5515     return MCDisassembler::Fail;
5516   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
5517     return MCDisassembler::Fail;
5518   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
5519     return MCDisassembler::Fail;
5520   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
5521     return MCDisassembler::Fail;
5522   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5523     return MCDisassembler::Fail;
5524 
5525   return S;
5526 }
5527 
5528 static DecodeStatus DecodeIT(MCInst &Inst, unsigned Insn,
5529                              uint64_t Address, const void *Decoder) {
5530   DecodeStatus S = MCDisassembler::Success;
5531   unsigned pred = fieldFromInstruction(Insn, 4, 4);
5532   unsigned mask = fieldFromInstruction(Insn, 0, 4);
5533 
5534   if (pred == 0xF) {
5535     pred = 0xE;
5536     S = MCDisassembler::SoftFail;
5537   }
5538 
5539   if (mask == 0x0)
5540     return MCDisassembler::Fail;
5541 
5542   // IT masks are encoded as a sequence of replacement low-order bits
5543   // for the condition code. So if the low bit of the starting
5544   // condition code is 1, then we have to flip all the bits above the
5545   // terminating bit (which is the lowest 1 bit).
5546   if (pred & 1) {
5547     unsigned LowBit = mask & -mask;
5548     unsigned BitsAboveLowBit = 0xF & (-LowBit << 1);
5549     mask ^= BitsAboveLowBit;
5550   }
5551 
5552   Inst.addOperand(MCOperand::createImm(pred));
5553   Inst.addOperand(MCOperand::createImm(mask));
5554   return S;
5555 }
5556 
5557 static DecodeStatus
5558 DecodeT2LDRDPreInstruction(MCInst &Inst, unsigned Insn,
5559                            uint64_t Address, const void *Decoder) {
5560   DecodeStatus S = MCDisassembler::Success;
5561 
5562   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5563   unsigned Rt2 = fieldFromInstruction(Insn, 8, 4);
5564   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5565   unsigned addr = fieldFromInstruction(Insn, 0, 8);
5566   unsigned W = fieldFromInstruction(Insn, 21, 1);
5567   unsigned U = fieldFromInstruction(Insn, 23, 1);
5568   unsigned P = fieldFromInstruction(Insn, 24, 1);
5569   bool writeback = (W == 1) | (P == 0);
5570 
5571   addr |= (U << 8) | (Rn << 9);
5572 
5573   if (writeback && (Rn == Rt || Rn == Rt2))
5574     Check(S, MCDisassembler::SoftFail);
5575   if (Rt == Rt2)
5576     Check(S, MCDisassembler::SoftFail);
5577 
5578   // Rt
5579   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
5580     return MCDisassembler::Fail;
5581   // Rt2
5582   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
5583     return MCDisassembler::Fail;
5584   // Writeback operand
5585   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
5586     return MCDisassembler::Fail;
5587   // addr
5588   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
5589     return MCDisassembler::Fail;
5590 
5591   return S;
5592 }
5593 
5594 static DecodeStatus
5595 DecodeT2STRDPreInstruction(MCInst &Inst, unsigned Insn,
5596                            uint64_t Address, const void *Decoder) {
5597   DecodeStatus S = MCDisassembler::Success;
5598 
5599   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5600   unsigned Rt2 = fieldFromInstruction(Insn, 8, 4);
5601   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5602   unsigned addr = fieldFromInstruction(Insn, 0, 8);
5603   unsigned W = fieldFromInstruction(Insn, 21, 1);
5604   unsigned U = fieldFromInstruction(Insn, 23, 1);
5605   unsigned P = fieldFromInstruction(Insn, 24, 1);
5606   bool writeback = (W == 1) | (P == 0);
5607 
5608   addr |= (U << 8) | (Rn << 9);
5609 
5610   if (writeback && (Rn == Rt || Rn == Rt2))
5611     Check(S, MCDisassembler::SoftFail);
5612 
5613   // Writeback operand
5614   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
5615     return MCDisassembler::Fail;
5616   // Rt
5617   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
5618     return MCDisassembler::Fail;
5619   // Rt2
5620   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
5621     return MCDisassembler::Fail;
5622   // addr
5623   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
5624     return MCDisassembler::Fail;
5625 
5626   return S;
5627 }
5628 
5629 static DecodeStatus DecodeT2Adr(MCInst &Inst, uint32_t Insn,
5630                                 uint64_t Address, const void *Decoder) {
5631   unsigned sign1 = fieldFromInstruction(Insn, 21, 1);
5632   unsigned sign2 = fieldFromInstruction(Insn, 23, 1);
5633   if (sign1 != sign2) return MCDisassembler::Fail;
5634   const unsigned Rd = fieldFromInstruction(Insn, 8, 4);
5635   assert(Inst.getNumOperands() == 0 && "We should receive an empty Inst");
5636   DecodeStatus S = DecoderGPRRegisterClass(Inst, Rd, Address, Decoder);
5637 
5638   unsigned Val = fieldFromInstruction(Insn, 0, 8);
5639   Val |= fieldFromInstruction(Insn, 12, 3) << 8;
5640   Val |= fieldFromInstruction(Insn, 26, 1) << 11;
5641   // If sign, then it is decreasing the address.
5642   if (sign1) {
5643     // Following ARMv7 Architecture Manual, when the offset
5644     // is zero, it is decoded as a subw, not as a adr.w
5645     if (!Val) {
5646       Inst.setOpcode(ARM::t2SUBri12);
5647       Inst.addOperand(MCOperand::createReg(ARM::PC));
5648     } else
5649       Val = -Val;
5650   }
5651   Inst.addOperand(MCOperand::createImm(Val));
5652   return S;
5653 }
5654 
5655 static DecodeStatus DecodeT2ShifterImmOperand(MCInst &Inst, uint32_t Val,
5656                                               uint64_t Address,
5657                                               const void *Decoder) {
5658   DecodeStatus S = MCDisassembler::Success;
5659 
5660   // Shift of "asr #32" is not allowed in Thumb2 mode.
5661   if (Val == 0x20) S = MCDisassembler::Fail;
5662   Inst.addOperand(MCOperand::createImm(Val));
5663   return S;
5664 }
5665 
5666 static DecodeStatus DecodeSwap(MCInst &Inst, unsigned Insn,
5667                                uint64_t Address, const void *Decoder) {
5668   unsigned Rt   = fieldFromInstruction(Insn, 12, 4);
5669   unsigned Rt2  = fieldFromInstruction(Insn, 0,  4);
5670   unsigned Rn   = fieldFromInstruction(Insn, 16, 4);
5671   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5672 
5673   if (pred == 0xF)
5674     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
5675 
5676   DecodeStatus S = MCDisassembler::Success;
5677 
5678   if (Rt == Rn || Rn == Rt2)
5679     S = MCDisassembler::SoftFail;
5680 
5681   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5682     return MCDisassembler::Fail;
5683   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5684     return MCDisassembler::Fail;
5685   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
5686     return MCDisassembler::Fail;
5687   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5688     return MCDisassembler::Fail;
5689 
5690   return S;
5691 }
5692 
5693 static DecodeStatus DecodeVCVTD(MCInst &Inst, unsigned Insn,
5694                                 uint64_t Address, const void *Decoder) {
5695   const FeatureBitset &featureBits =
5696       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5697   bool hasFullFP16 = featureBits[ARM::FeatureFullFP16];
5698 
5699   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5700   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5701   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5702   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5703   unsigned imm = fieldFromInstruction(Insn, 16, 6);
5704   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
5705   unsigned op = fieldFromInstruction(Insn, 5, 1);
5706 
5707   DecodeStatus S = MCDisassembler::Success;
5708 
5709   // If the top 3 bits of imm are clear, this is a VMOV (immediate)
5710   if (!(imm & 0x38)) {
5711     if (cmode == 0xF) {
5712       if (op == 1) return MCDisassembler::Fail;
5713       Inst.setOpcode(ARM::VMOVv2f32);
5714     }
5715     if (hasFullFP16) {
5716       if (cmode == 0xE) {
5717         if (op == 1) {
5718           Inst.setOpcode(ARM::VMOVv1i64);
5719         } else {
5720           Inst.setOpcode(ARM::VMOVv8i8);
5721         }
5722       }
5723       if (cmode == 0xD) {
5724         if (op == 1) {
5725           Inst.setOpcode(ARM::VMVNv2i32);
5726         } else {
5727           Inst.setOpcode(ARM::VMOVv2i32);
5728         }
5729       }
5730       if (cmode == 0xC) {
5731         if (op == 1) {
5732           Inst.setOpcode(ARM::VMVNv2i32);
5733         } else {
5734           Inst.setOpcode(ARM::VMOVv2i32);
5735         }
5736       }
5737     }
5738     return DecodeVMOVModImmInstruction(Inst, Insn, Address, Decoder);
5739   }
5740 
5741   if (!(imm & 0x20)) return MCDisassembler::Fail;
5742 
5743   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
5744     return MCDisassembler::Fail;
5745   if (!Check(S, DecodeDPRRegisterClass(Inst, Vm, Address, Decoder)))
5746     return MCDisassembler::Fail;
5747   Inst.addOperand(MCOperand::createImm(64 - imm));
5748 
5749   return S;
5750 }
5751 
5752 static DecodeStatus DecodeVCVTQ(MCInst &Inst, unsigned Insn,
5753                                 uint64_t Address, const void *Decoder) {
5754   const FeatureBitset &featureBits =
5755       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5756   bool hasFullFP16 = featureBits[ARM::FeatureFullFP16];
5757 
5758   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5759   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5760   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5761   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5762   unsigned imm = fieldFromInstruction(Insn, 16, 6);
5763   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
5764   unsigned op = fieldFromInstruction(Insn, 5, 1);
5765 
5766   DecodeStatus S = MCDisassembler::Success;
5767 
5768   // If the top 3 bits of imm are clear, this is a VMOV (immediate)
5769   if (!(imm & 0x38)) {
5770     if (cmode == 0xF) {
5771       if (op == 1) return MCDisassembler::Fail;
5772       Inst.setOpcode(ARM::VMOVv4f32);
5773     }
5774     if (hasFullFP16) {
5775       if (cmode == 0xE) {
5776         if (op == 1) {
5777           Inst.setOpcode(ARM::VMOVv2i64);
5778         } else {
5779           Inst.setOpcode(ARM::VMOVv16i8);
5780         }
5781       }
5782       if (cmode == 0xD) {
5783         if (op == 1) {
5784           Inst.setOpcode(ARM::VMVNv4i32);
5785         } else {
5786           Inst.setOpcode(ARM::VMOVv4i32);
5787         }
5788       }
5789       if (cmode == 0xC) {
5790         if (op == 1) {
5791           Inst.setOpcode(ARM::VMVNv4i32);
5792         } else {
5793           Inst.setOpcode(ARM::VMOVv4i32);
5794         }
5795       }
5796     }
5797     return DecodeVMOVModImmInstruction(Inst, Insn, Address, Decoder);
5798   }
5799 
5800   if (!(imm & 0x20)) return MCDisassembler::Fail;
5801 
5802   if (!Check(S, DecodeQPRRegisterClass(Inst, Vd, Address, Decoder)))
5803     return MCDisassembler::Fail;
5804   if (!Check(S, DecodeQPRRegisterClass(Inst, Vm, Address, Decoder)))
5805     return MCDisassembler::Fail;
5806   Inst.addOperand(MCOperand::createImm(64 - imm));
5807 
5808   return S;
5809 }
5810 
5811 static DecodeStatus DecodeNEONComplexLane64Instruction(MCInst &Inst,
5812                                                        unsigned Insn,
5813                                                        uint64_t Address,
5814                                                        const void *Decoder) {
5815   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5816   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5817   unsigned Vn = (fieldFromInstruction(Insn, 16, 4) << 0);
5818   Vn |= (fieldFromInstruction(Insn, 7, 1) << 4);
5819   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5820   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5821   unsigned q = (fieldFromInstruction(Insn, 6, 1) << 0);
5822   unsigned rotate = (fieldFromInstruction(Insn, 20, 2) << 0);
5823 
5824   DecodeStatus S = MCDisassembler::Success;
5825 
5826   auto DestRegDecoder = q ? DecodeQPRRegisterClass : DecodeDPRRegisterClass;
5827 
5828   if (!Check(S, DestRegDecoder(Inst, Vd, Address, Decoder)))
5829     return MCDisassembler::Fail;
5830   if (!Check(S, DestRegDecoder(Inst, Vd, Address, Decoder)))
5831     return MCDisassembler::Fail;
5832   if (!Check(S, DestRegDecoder(Inst, Vn, Address, Decoder)))
5833     return MCDisassembler::Fail;
5834   if (!Check(S, DecodeDPRRegisterClass(Inst, Vm, Address, Decoder)))
5835     return MCDisassembler::Fail;
5836   // The lane index does not have any bits in the encoding, because it can only
5837   // be 0.
5838   Inst.addOperand(MCOperand::createImm(0));
5839   Inst.addOperand(MCOperand::createImm(rotate));
5840 
5841   return S;
5842 }
5843 
5844 static DecodeStatus DecodeLDR(MCInst &Inst, unsigned Val,
5845                                 uint64_t Address, const void *Decoder) {
5846   DecodeStatus S = MCDisassembler::Success;
5847 
5848   unsigned Rn = fieldFromInstruction(Val, 16, 4);
5849   unsigned Rt = fieldFromInstruction(Val, 12, 4);
5850   unsigned Rm = fieldFromInstruction(Val, 0, 4);
5851   Rm |= (fieldFromInstruction(Val, 23, 1) << 4);
5852   unsigned Cond = fieldFromInstruction(Val, 28, 4);
5853 
5854   if (fieldFromInstruction(Val, 8, 4) != 0 || Rn == Rt)
5855     S = MCDisassembler::SoftFail;
5856 
5857   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5858     return MCDisassembler::Fail;
5859   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
5860     return MCDisassembler::Fail;
5861   if (!Check(S, DecodeAddrMode7Operand(Inst, Rn, Address, Decoder)))
5862     return MCDisassembler::Fail;
5863   if (!Check(S, DecodePostIdxReg(Inst, Rm, Address, Decoder)))
5864     return MCDisassembler::Fail;
5865   if (!Check(S, DecodePredicateOperand(Inst, Cond, Address, Decoder)))
5866     return MCDisassembler::Fail;
5867 
5868   return S;
5869 }
5870 
5871 static DecodeStatus DecoderForMRRC2AndMCRR2(MCInst &Inst, unsigned Val,
5872                                             uint64_t Address, const void *Decoder) {
5873   DecodeStatus S = MCDisassembler::Success;
5874 
5875   unsigned CRm = fieldFromInstruction(Val, 0, 4);
5876   unsigned opc1 = fieldFromInstruction(Val, 4, 4);
5877   unsigned cop = fieldFromInstruction(Val, 8, 4);
5878   unsigned Rt = fieldFromInstruction(Val, 12, 4);
5879   unsigned Rt2 = fieldFromInstruction(Val, 16, 4);
5880 
5881   if ((cop & ~0x1) == 0xa)
5882     return MCDisassembler::Fail;
5883 
5884   if (Rt == Rt2)
5885     S = MCDisassembler::SoftFail;
5886 
5887   // We have to check if the instruction is MRRC2
5888   // or MCRR2 when constructing the operands for
5889   // Inst. Reason is because MRRC2 stores to two
5890   // registers so it's tablegen desc has has two
5891   // outputs whereas MCRR doesn't store to any
5892   // registers so all of it's operands are listed
5893   // as inputs, therefore the operand order for
5894   // MRRC2 needs to be [Rt, Rt2, cop, opc1, CRm]
5895   // and MCRR2 operand order is [cop, opc1, Rt, Rt2, CRm]
5896 
5897   if (Inst.getOpcode() == ARM::MRRC2) {
5898     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5899       return MCDisassembler::Fail;
5900     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5901       return MCDisassembler::Fail;
5902   }
5903   Inst.addOperand(MCOperand::createImm(cop));
5904   Inst.addOperand(MCOperand::createImm(opc1));
5905   if (Inst.getOpcode() == ARM::MCRR2) {
5906     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5907       return MCDisassembler::Fail;
5908     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5909       return MCDisassembler::Fail;
5910   }
5911   Inst.addOperand(MCOperand::createImm(CRm));
5912 
5913   return S;
5914 }
5915 
5916 static DecodeStatus DecodeForVMRSandVMSR(MCInst &Inst, unsigned Val,
5917                                          uint64_t Address,
5918                                          const void *Decoder) {
5919   const FeatureBitset &featureBits =
5920       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5921   DecodeStatus S = MCDisassembler::Success;
5922 
5923   // Add explicit operand for the destination sysreg, for cases where
5924   // we have to model it for code generation purposes.
5925   switch (Inst.getOpcode()) {
5926   case ARM::VMSR_FPSCR_NZCVQC:
5927     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
5928     break;
5929   case ARM::VMSR_P0:
5930     Inst.addOperand(MCOperand::createReg(ARM::VPR));
5931     break;
5932   }
5933 
5934   if (Inst.getOpcode() != ARM::FMSTAT) {
5935     unsigned Rt = fieldFromInstruction(Val, 12, 4);
5936 
5937     if (featureBits[ARM::ModeThumb] && !featureBits[ARM::HasV8Ops]) {
5938       if (Rt == 13 || Rt == 15)
5939         S = MCDisassembler::SoftFail;
5940       Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder));
5941     } else
5942       Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder));
5943   }
5944 
5945   // Add explicit operand for the source sysreg, similarly to above.
5946   switch (Inst.getOpcode()) {
5947   case ARM::VMRS_FPSCR_NZCVQC:
5948     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
5949     break;
5950   case ARM::VMRS_P0:
5951     Inst.addOperand(MCOperand::createReg(ARM::VPR));
5952     break;
5953   }
5954 
5955   if (featureBits[ARM::ModeThumb]) {
5956     Inst.addOperand(MCOperand::createImm(ARMCC::AL));
5957     Inst.addOperand(MCOperand::createReg(0));
5958   } else {
5959     unsigned pred = fieldFromInstruction(Val, 28, 4);
5960     if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5961       return MCDisassembler::Fail;
5962   }
5963 
5964   return S;
5965 }
5966 
5967 template <bool isSigned, bool isNeg, bool zeroPermitted, int size>
5968 static DecodeStatus DecodeBFLabelOperand(MCInst &Inst, unsigned Val,
5969                                          uint64_t Address,
5970                                          const void *Decoder) {
5971   DecodeStatus S = MCDisassembler::Success;
5972   if (Val == 0 && !zeroPermitted)
5973     S = MCDisassembler::Fail;
5974 
5975   uint64_t DecVal;
5976   if (isSigned)
5977     DecVal = SignExtend32<size + 1>(Val << 1);
5978   else
5979     DecVal = (Val << 1);
5980 
5981   if (!tryAddingSymbolicOperand(Address, Address + DecVal + 4, true, 4, Inst,
5982                                 Decoder))
5983     Inst.addOperand(MCOperand::createImm(isNeg ? -DecVal : DecVal));
5984   return S;
5985 }
5986 
5987 static DecodeStatus DecodeBFAfterTargetOperand(MCInst &Inst, unsigned Val,
5988                                                uint64_t Address,
5989                                                const void *Decoder) {
5990 
5991   uint64_t LocImm = Inst.getOperand(0).getImm();
5992   Val = LocImm + (2 << Val);
5993   if (!tryAddingSymbolicOperand(Address, Address + Val + 4, true, 4, Inst,
5994                                 Decoder))
5995     Inst.addOperand(MCOperand::createImm(Val));
5996   return MCDisassembler::Success;
5997 }
5998 
5999 static DecodeStatus DecodePredNoALOperand(MCInst &Inst, unsigned Val,
6000                                           uint64_t Address,
6001                                           const void *Decoder) {
6002   if (Val >= ARMCC::AL)  // also exclude the non-condition NV
6003     return MCDisassembler::Fail;
6004   Inst.addOperand(MCOperand::createImm(Val));
6005   return MCDisassembler::Success;
6006 }
6007 
6008 static DecodeStatus DecodeLOLoop(MCInst &Inst, unsigned Insn, uint64_t Address,
6009                                  const void *Decoder) {
6010   DecodeStatus S = MCDisassembler::Success;
6011 
6012   if (Inst.getOpcode() == ARM::MVE_LCTP)
6013     return S;
6014 
6015   unsigned Imm = fieldFromInstruction(Insn, 11, 1) |
6016                  fieldFromInstruction(Insn, 1, 10) << 1;
6017   switch (Inst.getOpcode()) {
6018   case ARM::t2LEUpdate:
6019   case ARM::MVE_LETP:
6020     Inst.addOperand(MCOperand::createReg(ARM::LR));
6021     Inst.addOperand(MCOperand::createReg(ARM::LR));
6022     LLVM_FALLTHROUGH;
6023   case ARM::t2LE:
6024     if (!Check(S, DecodeBFLabelOperand<false, true, true, 11>(
6025                    Inst, Imm, Address, Decoder)))
6026       return MCDisassembler::Fail;
6027     break;
6028   case ARM::t2WLS:
6029   case ARM::MVE_WLSTP_8:
6030   case ARM::MVE_WLSTP_16:
6031   case ARM::MVE_WLSTP_32:
6032   case ARM::MVE_WLSTP_64:
6033     Inst.addOperand(MCOperand::createReg(ARM::LR));
6034     if (!Check(S,
6035                DecoderGPRRegisterClass(Inst, fieldFromInstruction(Insn, 16, 4),
6036                                        Address, Decoder)) ||
6037         !Check(S, DecodeBFLabelOperand<false, false, true, 11>(
6038                    Inst, Imm, Address, Decoder)))
6039       return MCDisassembler::Fail;
6040     break;
6041   case ARM::t2DLS:
6042   case ARM::MVE_DLSTP_8:
6043   case ARM::MVE_DLSTP_16:
6044   case ARM::MVE_DLSTP_32:
6045   case ARM::MVE_DLSTP_64:
6046     unsigned Rn = fieldFromInstruction(Insn, 16, 4);
6047     if (Rn == 0xF) {
6048       // Enforce all the rest of the instruction bits in LCTP, which
6049       // won't have been reliably checked based on LCTP's own tablegen
6050       // record, because we came to this decode by a roundabout route.
6051       uint32_t CanonicalLCTP = 0xF00FE001, SBZMask = 0x00300FFE;
6052       if ((Insn & ~SBZMask) != CanonicalLCTP)
6053         return MCDisassembler::Fail;   // a mandatory bit is wrong: hard fail
6054       if (Insn != CanonicalLCTP)
6055         Check(S, MCDisassembler::SoftFail); // an SBZ bit is wrong: soft fail
6056 
6057       Inst.setOpcode(ARM::MVE_LCTP);
6058     } else {
6059       Inst.addOperand(MCOperand::createReg(ARM::LR));
6060       if (!Check(S, DecoderGPRRegisterClass(Inst,
6061                                             fieldFromInstruction(Insn, 16, 4),
6062                                             Address, Decoder)))
6063         return MCDisassembler::Fail;
6064     }
6065     break;
6066   }
6067   return S;
6068 }
6069 
6070 static DecodeStatus DecodeLongShiftOperand(MCInst &Inst, unsigned Val,
6071                                            uint64_t Address,
6072                                            const void *Decoder) {
6073   DecodeStatus S = MCDisassembler::Success;
6074 
6075   if (Val == 0)
6076     Val = 32;
6077 
6078   Inst.addOperand(MCOperand::createImm(Val));
6079 
6080   return S;
6081 }
6082 
6083 static DecodeStatus DecodetGPROddRegisterClass(MCInst &Inst, unsigned RegNo,
6084                                    uint64_t Address, const void *Decoder) {
6085   if ((RegNo) + 1 > 11)
6086     return MCDisassembler::Fail;
6087 
6088   unsigned Register = GPRDecoderTable[(RegNo) + 1];
6089   Inst.addOperand(MCOperand::createReg(Register));
6090   return MCDisassembler::Success;
6091 }
6092 
6093 static DecodeStatus DecodetGPREvenRegisterClass(MCInst &Inst, unsigned RegNo,
6094                                    uint64_t Address, const void *Decoder) {
6095   if ((RegNo) > 14)
6096     return MCDisassembler::Fail;
6097 
6098   unsigned Register = GPRDecoderTable[(RegNo)];
6099   Inst.addOperand(MCOperand::createReg(Register));
6100   return MCDisassembler::Success;
6101 }
6102 
6103 static DecodeStatus
6104 DecodeGPRwithAPSR_NZCVnospRegisterClass(MCInst &Inst, unsigned RegNo,
6105                                         uint64_t Address, const void *Decoder) {
6106   if (RegNo == 15) {
6107     Inst.addOperand(MCOperand::createReg(ARM::APSR_NZCV));
6108     return MCDisassembler::Success;
6109   }
6110 
6111   unsigned Register = GPRDecoderTable[RegNo];
6112   Inst.addOperand(MCOperand::createReg(Register));
6113 
6114   if (RegNo == 13)
6115     return MCDisassembler::SoftFail;
6116 
6117   return MCDisassembler::Success;
6118 }
6119 
6120 static DecodeStatus DecodeVSCCLRM(MCInst &Inst, unsigned Insn, uint64_t Address,
6121                                   const void *Decoder) {
6122   DecodeStatus S = MCDisassembler::Success;
6123 
6124   Inst.addOperand(MCOperand::createImm(ARMCC::AL));
6125   Inst.addOperand(MCOperand::createReg(0));
6126   if (Inst.getOpcode() == ARM::VSCCLRMD) {
6127     unsigned reglist = (fieldFromInstruction(Insn, 1, 7) << 1) |
6128                        (fieldFromInstruction(Insn, 12, 4) << 8) |
6129                        (fieldFromInstruction(Insn, 22, 1) << 12);
6130     if (!Check(S, DecodeDPRRegListOperand(Inst, reglist, Address, Decoder))) {
6131       return MCDisassembler::Fail;
6132     }
6133   } else {
6134     unsigned reglist = fieldFromInstruction(Insn, 0, 8) |
6135                        (fieldFromInstruction(Insn, 22, 1) << 8) |
6136                        (fieldFromInstruction(Insn, 12, 4) << 9);
6137     if (!Check(S, DecodeSPRRegListOperand(Inst, reglist, Address, Decoder))) {
6138       return MCDisassembler::Fail;
6139     }
6140   }
6141   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6142 
6143   return S;
6144 }
6145 
6146 static DecodeStatus DecodeMQPRRegisterClass(MCInst &Inst, unsigned RegNo,
6147                               uint64_t Address,
6148                               const void *Decoder) {
6149   if (RegNo > 7)
6150     return MCDisassembler::Fail;
6151 
6152   unsigned Register = QPRDecoderTable[RegNo];
6153   Inst.addOperand(MCOperand::createReg(Register));
6154   return MCDisassembler::Success;
6155 }
6156 
6157 static const uint16_t QQPRDecoderTable[] = {
6158      ARM::Q0_Q1,  ARM::Q1_Q2,  ARM::Q2_Q3,  ARM::Q3_Q4,
6159      ARM::Q4_Q5,  ARM::Q5_Q6,  ARM::Q6_Q7
6160 };
6161 
6162 static DecodeStatus DecodeMQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
6163                                              uint64_t Address,
6164                                              const void *Decoder) {
6165   if (RegNo > 6)
6166     return MCDisassembler::Fail;
6167 
6168   unsigned Register = QQPRDecoderTable[RegNo];
6169   Inst.addOperand(MCOperand::createReg(Register));
6170   return MCDisassembler::Success;
6171 }
6172 
6173 static const uint16_t QQQQPRDecoderTable[] = {
6174      ARM::Q0_Q1_Q2_Q3,  ARM::Q1_Q2_Q3_Q4,  ARM::Q2_Q3_Q4_Q5,
6175      ARM::Q3_Q4_Q5_Q6,  ARM::Q4_Q5_Q6_Q7
6176 };
6177 
6178 static DecodeStatus DecodeMQQQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
6179                                                uint64_t Address,
6180                                                const void *Decoder) {
6181   if (RegNo > 4)
6182     return MCDisassembler::Fail;
6183 
6184   unsigned Register = QQQQPRDecoderTable[RegNo];
6185   Inst.addOperand(MCOperand::createReg(Register));
6186   return MCDisassembler::Success;
6187 }
6188 
6189 static DecodeStatus DecodeVPTMaskOperand(MCInst &Inst, unsigned Val,
6190                                          uint64_t Address,
6191                                          const void *Decoder) {
6192   DecodeStatus S = MCDisassembler::Success;
6193 
6194   // Parse VPT mask and encode it in the MCInst as an immediate with the same
6195   // format as the it_mask.  That is, from the second 'e|t' encode 'e' as 1 and
6196   // 't' as 0 and finish with a 1.
6197   unsigned Imm = 0;
6198   // We always start with a 't'.
6199   unsigned CurBit = 0;
6200   for (int i = 3; i >= 0; --i) {
6201     // If the bit we are looking at is not the same as last one, invert the
6202     // CurBit, if it is the same leave it as is.
6203     CurBit ^= (Val >> i) & 1U;
6204 
6205     // Encode the CurBit at the right place in the immediate.
6206     Imm |= (CurBit << i);
6207 
6208     // If we are done, finish the encoding with a 1.
6209     if ((Val & ~(~0U << i)) == 0) {
6210       Imm |= 1U << i;
6211       break;
6212     }
6213   }
6214 
6215   Inst.addOperand(MCOperand::createImm(Imm));
6216 
6217   return S;
6218 }
6219 
6220 static DecodeStatus DecodeVpredROperand(MCInst &Inst, unsigned RegNo,
6221                                         uint64_t Address, const void *Decoder) {
6222   // The vpred_r operand type includes an MQPR register field derived
6223   // from the encoding. But we don't actually want to add an operand
6224   // to the MCInst at this stage, because AddThumbPredicate will do it
6225   // later, and will infer the register number from the TIED_TO
6226   // constraint. So this is a deliberately empty decoder method that
6227   // will inhibit the auto-generated disassembly code from adding an
6228   // operand at all.
6229   return MCDisassembler::Success;
6230 }
6231 
6232 static DecodeStatus DecodeRestrictedIPredicateOperand(MCInst &Inst,
6233                                                       unsigned Val,
6234                                                       uint64_t Address,
6235                                                       const void *Decoder) {
6236   Inst.addOperand(MCOperand::createImm((Val & 0x1) == 0 ? ARMCC::EQ : ARMCC::NE));
6237   return MCDisassembler::Success;
6238 }
6239 
6240 static DecodeStatus DecodeRestrictedSPredicateOperand(MCInst &Inst,
6241                                                       unsigned Val,
6242                                                       uint64_t Address,
6243                                                       const void *Decoder) {
6244   unsigned Code;
6245   switch (Val & 0x3) {
6246   case 0:
6247     Code = ARMCC::GE;
6248     break;
6249   case 1:
6250     Code = ARMCC::LT;
6251     break;
6252   case 2:
6253     Code = ARMCC::GT;
6254     break;
6255   case 3:
6256     Code = ARMCC::LE;
6257     break;
6258   }
6259   Inst.addOperand(MCOperand::createImm(Code));
6260   return MCDisassembler::Success;
6261 }
6262 
6263 static DecodeStatus DecodeRestrictedUPredicateOperand(MCInst &Inst,
6264                                                       unsigned Val,
6265                                                       uint64_t Address,
6266                                                       const void *Decoder) {
6267   Inst.addOperand(MCOperand::createImm((Val & 0x1) == 0 ? ARMCC::HS : ARMCC::HI));
6268   return MCDisassembler::Success;
6269 }
6270 
6271 static DecodeStatus DecodeRestrictedFPPredicateOperand(MCInst &Inst, unsigned Val,
6272                                                      uint64_t Address,
6273                                                      const void *Decoder) {
6274   unsigned Code;
6275   switch (Val) {
6276   default:
6277     return MCDisassembler::Fail;
6278   case 0:
6279     Code = ARMCC::EQ;
6280     break;
6281   case 1:
6282     Code = ARMCC::NE;
6283     break;
6284   case 4:
6285     Code = ARMCC::GE;
6286     break;
6287   case 5:
6288     Code = ARMCC::LT;
6289     break;
6290   case 6:
6291     Code = ARMCC::GT;
6292     break;
6293   case 7:
6294     Code = ARMCC::LE;
6295     break;
6296   }
6297 
6298   Inst.addOperand(MCOperand::createImm(Code));
6299   return MCDisassembler::Success;
6300 }
6301 
6302 static DecodeStatus DecodeVCVTImmOperand(MCInst &Inst, unsigned Val,
6303                                          uint64_t Address, const void *Decoder) {
6304   DecodeStatus S = MCDisassembler::Success;
6305 
6306   unsigned DecodedVal = 64 - Val;
6307 
6308   switch (Inst.getOpcode()) {
6309   case ARM::MVE_VCVTf16s16_fix:
6310   case ARM::MVE_VCVTs16f16_fix:
6311   case ARM::MVE_VCVTf16u16_fix:
6312   case ARM::MVE_VCVTu16f16_fix:
6313     if (DecodedVal > 16)
6314       return MCDisassembler::Fail;
6315     break;
6316   case ARM::MVE_VCVTf32s32_fix:
6317   case ARM::MVE_VCVTs32f32_fix:
6318   case ARM::MVE_VCVTf32u32_fix:
6319   case ARM::MVE_VCVTu32f32_fix:
6320     if (DecodedVal > 32)
6321       return MCDisassembler::Fail;
6322     break;
6323   }
6324 
6325   Inst.addOperand(MCOperand::createImm(64 - Val));
6326 
6327   return S;
6328 }
6329 
6330 static unsigned FixedRegForVSTRVLDR_SYSREG(unsigned Opcode) {
6331   switch (Opcode) {
6332   case ARM::VSTR_P0_off:
6333   case ARM::VSTR_P0_pre:
6334   case ARM::VSTR_P0_post:
6335   case ARM::VLDR_P0_off:
6336   case ARM::VLDR_P0_pre:
6337   case ARM::VLDR_P0_post:
6338     return ARM::P0;
6339   default:
6340     return 0;
6341   }
6342 }
6343 
6344 template<bool Writeback>
6345 static DecodeStatus DecodeVSTRVLDR_SYSREG(MCInst &Inst, unsigned Val,
6346                                           uint64_t Address,
6347                                           const void *Decoder) {
6348   switch (Inst.getOpcode()) {
6349   case ARM::VSTR_FPSCR_pre:
6350   case ARM::VSTR_FPSCR_NZCVQC_pre:
6351   case ARM::VLDR_FPSCR_pre:
6352   case ARM::VLDR_FPSCR_NZCVQC_pre:
6353   case ARM::VSTR_FPSCR_off:
6354   case ARM::VSTR_FPSCR_NZCVQC_off:
6355   case ARM::VLDR_FPSCR_off:
6356   case ARM::VLDR_FPSCR_NZCVQC_off:
6357   case ARM::VSTR_FPSCR_post:
6358   case ARM::VSTR_FPSCR_NZCVQC_post:
6359   case ARM::VLDR_FPSCR_post:
6360   case ARM::VLDR_FPSCR_NZCVQC_post:
6361     const FeatureBitset &featureBits =
6362         ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
6363 
6364     if (!featureBits[ARM::HasMVEIntegerOps] && !featureBits[ARM::FeatureVFP2])
6365       return MCDisassembler::Fail;
6366   }
6367 
6368   DecodeStatus S = MCDisassembler::Success;
6369   if (unsigned Sysreg = FixedRegForVSTRVLDR_SYSREG(Inst.getOpcode()))
6370     Inst.addOperand(MCOperand::createReg(Sysreg));
6371   unsigned Rn = fieldFromInstruction(Val, 16, 4);
6372   unsigned addr = fieldFromInstruction(Val, 0, 7) |
6373                   (fieldFromInstruction(Val, 23, 1) << 7) | (Rn << 8);
6374 
6375   if (Writeback) {
6376     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
6377       return MCDisassembler::Fail;
6378   }
6379   if (!Check(S, DecodeT2AddrModeImm7s4(Inst, addr, Address, Decoder)))
6380     return MCDisassembler::Fail;
6381 
6382   Inst.addOperand(MCOperand::createImm(ARMCC::AL));
6383   Inst.addOperand(MCOperand::createReg(0));
6384 
6385   return S;
6386 }
6387 
6388 static inline DecodeStatus DecodeMVE_MEM_pre(
6389   MCInst &Inst, unsigned Val, uint64_t Address, const void *Decoder,
6390   unsigned Rn, OperandDecoder RnDecoder, OperandDecoder AddrDecoder) {
6391   DecodeStatus S = MCDisassembler::Success;
6392 
6393   unsigned Qd = fieldFromInstruction(Val, 13, 3);
6394   unsigned addr = fieldFromInstruction(Val, 0, 7) |
6395                   (fieldFromInstruction(Val, 23, 1) << 7) | (Rn << 8);
6396 
6397   if (!Check(S, RnDecoder(Inst, Rn, Address, Decoder)))
6398     return MCDisassembler::Fail;
6399   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6400     return MCDisassembler::Fail;
6401   if (!Check(S, AddrDecoder(Inst, addr, Address, Decoder)))
6402     return MCDisassembler::Fail;
6403 
6404   return S;
6405 }
6406 
6407 template <int shift>
6408 static DecodeStatus DecodeMVE_MEM_1_pre(MCInst &Inst, unsigned Val,
6409                                         uint64_t Address, const void *Decoder) {
6410   return DecodeMVE_MEM_pre(Inst, Val, Address, Decoder,
6411                            fieldFromInstruction(Val, 16, 3),
6412                            DecodetGPRRegisterClass,
6413                            DecodeTAddrModeImm7<shift>);
6414 }
6415 
6416 template <int shift>
6417 static DecodeStatus DecodeMVE_MEM_2_pre(MCInst &Inst, unsigned Val,
6418                                         uint64_t Address, const void *Decoder) {
6419   return DecodeMVE_MEM_pre(Inst, Val, Address, Decoder,
6420                            fieldFromInstruction(Val, 16, 4),
6421                            DecoderGPRRegisterClass,
6422                            DecodeT2AddrModeImm7<shift,1>);
6423 }
6424 
6425 template <int shift>
6426 static DecodeStatus DecodeMVE_MEM_3_pre(MCInst &Inst, unsigned Val,
6427                                         uint64_t Address, const void *Decoder) {
6428   return DecodeMVE_MEM_pre(Inst, Val, Address, Decoder,
6429                            fieldFromInstruction(Val, 17, 3),
6430                            DecodeMQPRRegisterClass,
6431                            DecodeMveAddrModeQ<shift>);
6432 }
6433 
6434 template<unsigned MinLog, unsigned MaxLog>
6435 static DecodeStatus DecodePowerTwoOperand(MCInst &Inst, unsigned Val,
6436                                           uint64_t Address,
6437                                           const void *Decoder) {
6438   DecodeStatus S = MCDisassembler::Success;
6439 
6440   if (Val < MinLog || Val > MaxLog)
6441     return MCDisassembler::Fail;
6442 
6443   Inst.addOperand(MCOperand::createImm(1LL << Val));
6444   return S;
6445 }
6446 
6447 template<unsigned start>
6448 static DecodeStatus DecodeMVEPairVectorIndexOperand(MCInst &Inst, unsigned Val,
6449                                                     uint64_t Address,
6450                                                     const void *Decoder) {
6451   DecodeStatus S = MCDisassembler::Success;
6452 
6453   Inst.addOperand(MCOperand::createImm(start + Val));
6454 
6455   return S;
6456 }
6457 
6458 static DecodeStatus DecodeMVEVMOVQtoDReg(MCInst &Inst, unsigned Insn,
6459                                          uint64_t Address, const void *Decoder) {
6460   DecodeStatus S = MCDisassembler::Success;
6461   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
6462   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
6463   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
6464                  fieldFromInstruction(Insn, 13, 3));
6465   unsigned index = fieldFromInstruction(Insn, 4, 1);
6466 
6467   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
6468     return MCDisassembler::Fail;
6469   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2, Address, Decoder)))
6470     return MCDisassembler::Fail;
6471   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6472     return MCDisassembler::Fail;
6473   if (!Check(S, DecodeMVEPairVectorIndexOperand<2>(Inst, index, Address, Decoder)))
6474     return MCDisassembler::Fail;
6475   if (!Check(S, DecodeMVEPairVectorIndexOperand<0>(Inst, index, Address, Decoder)))
6476     return MCDisassembler::Fail;
6477 
6478   return S;
6479 }
6480 
6481 static DecodeStatus DecodeMVEVMOVDRegtoQ(MCInst &Inst, unsigned Insn,
6482                                          uint64_t Address, const void *Decoder) {
6483   DecodeStatus S = MCDisassembler::Success;
6484   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
6485   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
6486   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
6487                  fieldFromInstruction(Insn, 13, 3));
6488   unsigned index = fieldFromInstruction(Insn, 4, 1);
6489 
6490   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6491     return MCDisassembler::Fail;
6492   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6493     return MCDisassembler::Fail;
6494   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
6495     return MCDisassembler::Fail;
6496   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2, Address, Decoder)))
6497     return MCDisassembler::Fail;
6498   if (!Check(S, DecodeMVEPairVectorIndexOperand<2>(Inst, index, Address, Decoder)))
6499     return MCDisassembler::Fail;
6500   if (!Check(S, DecodeMVEPairVectorIndexOperand<0>(Inst, index, Address, Decoder)))
6501     return MCDisassembler::Fail;
6502 
6503   return S;
6504 }
6505 
6506 static DecodeStatus DecodeMVEOverlappingLongShift(
6507   MCInst &Inst, unsigned Insn, uint64_t Address, const void *Decoder) {
6508   DecodeStatus S = MCDisassembler::Success;
6509 
6510   unsigned RdaLo = fieldFromInstruction(Insn, 17, 3) << 1;
6511   unsigned RdaHi = fieldFromInstruction(Insn, 9, 3) << 1;
6512   unsigned Rm = fieldFromInstruction(Insn, 12, 4);
6513 
6514   if (RdaHi == 14) {
6515     // This value of RdaHi (really indicating pc, because RdaHi has to
6516     // be an odd-numbered register, so the low bit will be set by the
6517     // decode function below) indicates that we must decode as SQRSHR
6518     // or UQRSHL, which both have a single Rda register field with all
6519     // four bits.
6520     unsigned Rda = fieldFromInstruction(Insn, 16, 4);
6521 
6522     switch (Inst.getOpcode()) {
6523       case ARM::MVE_ASRLr:
6524       case ARM::MVE_SQRSHRL:
6525         Inst.setOpcode(ARM::MVE_SQRSHR);
6526         break;
6527       case ARM::MVE_LSLLr:
6528       case ARM::MVE_UQRSHLL:
6529         Inst.setOpcode(ARM::MVE_UQRSHL);
6530         break;
6531       default:
6532         llvm_unreachable("Unexpected starting opcode!");
6533     }
6534 
6535     // Rda as output parameter
6536     if (!Check(S, DecoderGPRRegisterClass(Inst, Rda, Address, Decoder)))
6537       return MCDisassembler::Fail;
6538 
6539     // Rda again as input parameter
6540     if (!Check(S, DecoderGPRRegisterClass(Inst, Rda, Address, Decoder)))
6541       return MCDisassembler::Fail;
6542 
6543     // Rm, the amount to shift by
6544     if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
6545       return MCDisassembler::Fail;
6546 
6547     if (fieldFromInstruction (Insn, 6, 3) != 4)
6548       return MCDisassembler::SoftFail;
6549 
6550     if (Rda == Rm)
6551       return MCDisassembler::SoftFail;
6552 
6553     return S;
6554   }
6555 
6556   // Otherwise, we decode as whichever opcode our caller has already
6557   // put into Inst. Those all look the same:
6558 
6559   // RdaLo,RdaHi as output parameters
6560   if (!Check(S, DecodetGPREvenRegisterClass(Inst, RdaLo, Address, Decoder)))
6561     return MCDisassembler::Fail;
6562   if (!Check(S, DecodetGPROddRegisterClass(Inst, RdaHi, Address, Decoder)))
6563     return MCDisassembler::Fail;
6564 
6565   // RdaLo,RdaHi again as input parameters
6566   if (!Check(S, DecodetGPREvenRegisterClass(Inst, RdaLo, Address, Decoder)))
6567     return MCDisassembler::Fail;
6568   if (!Check(S, DecodetGPROddRegisterClass(Inst, RdaHi, Address, Decoder)))
6569     return MCDisassembler::Fail;
6570 
6571   // Rm, the amount to shift by
6572   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
6573     return MCDisassembler::Fail;
6574 
6575   if (Inst.getOpcode() == ARM::MVE_SQRSHRL ||
6576       Inst.getOpcode() == ARM::MVE_UQRSHLL) {
6577     unsigned Saturate = fieldFromInstruction(Insn, 7, 1);
6578     // Saturate, the bit position for saturation
6579     Inst.addOperand(MCOperand::createImm(Saturate));
6580   }
6581 
6582   return S;
6583 }
6584 
6585 static DecodeStatus DecodeMVEVCVTt1fp(MCInst &Inst, unsigned Insn, uint64_t Address,
6586                                       const void *Decoder) {
6587   DecodeStatus S = MCDisassembler::Success;
6588   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
6589                  fieldFromInstruction(Insn, 13, 3));
6590   unsigned Qm = ((fieldFromInstruction(Insn, 5, 1) << 3) |
6591                  fieldFromInstruction(Insn, 1, 3));
6592   unsigned imm6 = fieldFromInstruction(Insn, 16, 6);
6593 
6594   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6595     return MCDisassembler::Fail;
6596   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
6597     return MCDisassembler::Fail;
6598   if (!Check(S, DecodeVCVTImmOperand(Inst, imm6, Address, Decoder)))
6599     return MCDisassembler::Fail;
6600 
6601   return S;
6602 }
6603 
6604 template<bool scalar, OperandDecoder predicate_decoder>
6605 static DecodeStatus DecodeMVEVCMP(MCInst &Inst, unsigned Insn, uint64_t Address,
6606                                   const void *Decoder) {
6607   DecodeStatus S = MCDisassembler::Success;
6608   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6609   unsigned Qn = fieldFromInstruction(Insn, 17, 3);
6610   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qn, Address, Decoder)))
6611     return MCDisassembler::Fail;
6612 
6613   unsigned fc;
6614 
6615   if (scalar) {
6616     fc = fieldFromInstruction(Insn, 12, 1) << 2 |
6617          fieldFromInstruction(Insn, 7, 1) |
6618          fieldFromInstruction(Insn, 5, 1) << 1;
6619     unsigned Rm = fieldFromInstruction(Insn, 0, 4);
6620     if (!Check(S, DecodeGPRwithZRRegisterClass(Inst, Rm, Address, Decoder)))
6621       return MCDisassembler::Fail;
6622   } else {
6623     fc = fieldFromInstruction(Insn, 12, 1) << 2 |
6624          fieldFromInstruction(Insn, 7, 1) |
6625          fieldFromInstruction(Insn, 0, 1) << 1;
6626     unsigned Qm = fieldFromInstruction(Insn, 5, 1) << 4 |
6627                   fieldFromInstruction(Insn, 1, 3);
6628     if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
6629       return MCDisassembler::Fail;
6630   }
6631 
6632   if (!Check(S, predicate_decoder(Inst, fc, Address, Decoder)))
6633     return MCDisassembler::Fail;
6634 
6635   Inst.addOperand(MCOperand::createImm(ARMVCC::None));
6636   Inst.addOperand(MCOperand::createReg(0));
6637   Inst.addOperand(MCOperand::createImm(0));
6638 
6639   return S;
6640 }
6641 
6642 static DecodeStatus DecodeMveVCTP(MCInst &Inst, unsigned Insn, uint64_t Address,
6643                                   const void *Decoder) {
6644   DecodeStatus S = MCDisassembler::Success;
6645   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6646   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
6647   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
6648     return MCDisassembler::Fail;
6649   return S;
6650 }
6651 
6652 static DecodeStatus DecodeMVEVPNOT(MCInst &Inst, unsigned Insn, uint64_t Address,
6653                                    const void *Decoder) {
6654   DecodeStatus S = MCDisassembler::Success;
6655   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6656   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6657   return S;
6658 }
6659 
6660 static DecodeStatus DecodeT2AddSubSPImm(MCInst &Inst, unsigned Insn,
6661                                         uint64_t Address, const void *Decoder) {
6662   const unsigned Rd = fieldFromInstruction(Insn, 8, 4);
6663   const unsigned Rn = fieldFromInstruction(Insn, 16, 4);
6664   const unsigned Imm12 = fieldFromInstruction(Insn, 26, 1) << 11 |
6665                          fieldFromInstruction(Insn, 12, 3) << 8 |
6666                          fieldFromInstruction(Insn, 0, 8);
6667   const unsigned TypeT3 = fieldFromInstruction(Insn, 25, 1);
6668   unsigned sign1 = fieldFromInstruction(Insn, 21, 1);
6669   unsigned sign2 = fieldFromInstruction(Insn, 23, 1);
6670   unsigned S = fieldFromInstruction(Insn, 20, 1);
6671   if (sign1 != sign2)
6672     return MCDisassembler::Fail;
6673 
6674   // T3 does a zext of imm12, where T2 does a ThumbExpandImm (T2SOImm)
6675   DecodeStatus DS = MCDisassembler::Success;
6676   if ((!Check(DS,
6677               DecodeGPRspRegisterClass(Inst, Rd, Address, Decoder))) || // dst
6678       (!Check(DS, DecodeGPRspRegisterClass(Inst, Rn, Address, Decoder))))
6679     return MCDisassembler::Fail;
6680   if (TypeT3) {
6681     Inst.setOpcode(sign1 ? ARM::t2SUBspImm12 : ARM::t2ADDspImm12);
6682     Inst.addOperand(MCOperand::createImm(Imm12)); // zext imm12
6683   } else {
6684     Inst.setOpcode(sign1 ? ARM::t2SUBspImm : ARM::t2ADDspImm);
6685     if (!Check(DS, DecodeT2SOImm(Inst, Imm12, Address, Decoder))) // imm12
6686       return MCDisassembler::Fail;
6687     if (!Check(DS, DecodeCCOutOperand(Inst, S, Address, Decoder))) // cc_out
6688       return MCDisassembler::Fail;
6689   }
6690 
6691   return DS;
6692 }
6693