1 //===- ARMDisassembler.cpp - Disassembler for ARM/Thumb ISA ---------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "ARMBaseInstrInfo.h"
10 #include "MCTargetDesc/ARMAddressingModes.h"
11 #include "MCTargetDesc/ARMBaseInfo.h"
12 #include "MCTargetDesc/ARMMCTargetDesc.h"
13 #include "TargetInfo/ARMTargetInfo.h"
14 #include "Utils/ARMBaseInfo.h"
15 #include "llvm/MC/MCContext.h"
16 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
17 #include "llvm/MC/MCFixedLenDisassembler.h"
18 #include "llvm/MC/MCInst.h"
19 #include "llvm/MC/MCInstrDesc.h"
20 #include "llvm/MC/MCSubtargetInfo.h"
21 #include "llvm/MC/SubtargetFeature.h"
22 #include "llvm/Support/Compiler.h"
23 #include "llvm/Support/ErrorHandling.h"
24 #include "llvm/Support/MathExtras.h"
25 #include "llvm/Support/TargetRegistry.h"
26 #include "llvm/Support/raw_ostream.h"
27 #include <algorithm>
28 #include <cassert>
29 #include <cstdint>
30 #include <vector>
31 
32 using namespace llvm;
33 
34 #define DEBUG_TYPE "arm-disassembler"
35 
36 using DecodeStatus = MCDisassembler::DecodeStatus;
37 
38 namespace {
39 
40   // Handles the condition code status of instructions in IT blocks
41   class ITStatus
42   {
43     public:
44       // Returns the condition code for instruction in IT block
45       unsigned getITCC() {
46         unsigned CC = ARMCC::AL;
47         if (instrInITBlock())
48           CC = ITStates.back();
49         return CC;
50       }
51 
52       // Advances the IT block state to the next T or E
53       void advanceITState() {
54         ITStates.pop_back();
55       }
56 
57       // Returns true if the current instruction is in an IT block
58       bool instrInITBlock() {
59         return !ITStates.empty();
60       }
61 
62       // Returns true if current instruction is the last instruction in an IT block
63       bool instrLastInITBlock() {
64         return ITStates.size() == 1;
65       }
66 
67       // Called when decoding an IT instruction. Sets the IT state for
68       // the following instructions that for the IT block. Firstcond
69       // corresponds to the field in the IT instruction encoding; Mask
70       // is in the MCOperand format in which 1 means 'else' and 0 'then'.
71       void setITState(char Firstcond, char Mask) {
72         // (3 - the number of trailing zeros) is the number of then / else.
73         unsigned NumTZ = countTrailingZeros<uint8_t>(Mask);
74         unsigned char CCBits = static_cast<unsigned char>(Firstcond & 0xf);
75         assert(NumTZ <= 3 && "Invalid IT mask!");
76         // push condition codes onto the stack the correct order for the pops
77         for (unsigned Pos = NumTZ+1; Pos <= 3; ++Pos) {
78           unsigned Else = (Mask >> Pos) & 1;
79           ITStates.push_back(CCBits ^ Else);
80         }
81         ITStates.push_back(CCBits);
82       }
83 
84     private:
85       std::vector<unsigned char> ITStates;
86   };
87 
88   class VPTStatus
89   {
90     public:
91       unsigned getVPTPred() {
92         unsigned Pred = ARMVCC::None;
93         if (instrInVPTBlock())
94           Pred = VPTStates.back();
95         return Pred;
96       }
97 
98       void advanceVPTState() {
99         VPTStates.pop_back();
100       }
101 
102       bool instrInVPTBlock() {
103         return !VPTStates.empty();
104       }
105 
106       bool instrLastInVPTBlock() {
107         return VPTStates.size() == 1;
108       }
109 
110       void setVPTState(char Mask) {
111         // (3 - the number of trailing zeros) is the number of then / else.
112         unsigned NumTZ = countTrailingZeros<uint8_t>(Mask);
113         assert(NumTZ <= 3 && "Invalid VPT mask!");
114         // push predicates onto the stack the correct order for the pops
115         for (unsigned Pos = NumTZ+1; Pos <= 3; ++Pos) {
116           bool T = ((Mask >> Pos) & 1) == 0;
117           if (T)
118             VPTStates.push_back(ARMVCC::Then);
119           else
120             VPTStates.push_back(ARMVCC::Else);
121         }
122         VPTStates.push_back(ARMVCC::Then);
123       }
124 
125     private:
126       SmallVector<unsigned char, 4> VPTStates;
127   };
128 
129 /// ARM disassembler for all ARM platforms.
130 class ARMDisassembler : public MCDisassembler {
131 public:
132   ARMDisassembler(const MCSubtargetInfo &STI, MCContext &Ctx) :
133     MCDisassembler(STI, Ctx) {
134   }
135 
136   ~ARMDisassembler() override = default;
137 
138   DecodeStatus getInstruction(MCInst &Instr, uint64_t &Size,
139                               ArrayRef<uint8_t> Bytes, uint64_t Address,
140                               raw_ostream &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 DecodeQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
231                                    uint64_t Address, const void *Decoder);
232 static DecodeStatus DecodeQQQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
233                                    uint64_t Address, const void *Decoder);
234 static DecodeStatus DecodeDPairRegisterClass(MCInst &Inst, unsigned RegNo,
235                                    uint64_t Address, const void *Decoder);
236 static DecodeStatus DecodeDPairSpacedRegisterClass(MCInst &Inst,
237                                unsigned RegNo, uint64_t Address,
238                                const void *Decoder);
239 
240 static DecodeStatus DecodePredicateOperand(MCInst &Inst, unsigned Val,
241                                uint64_t Address, const void *Decoder);
242 static DecodeStatus DecodeCCOutOperand(MCInst &Inst, unsigned Val,
243                                uint64_t Address, const void *Decoder);
244 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Val,
245                                uint64_t Address, const void *Decoder);
246 static DecodeStatus DecodeSPRRegListOperand(MCInst &Inst, unsigned Val,
247                                uint64_t Address, const void *Decoder);
248 static DecodeStatus DecodeDPRRegListOperand(MCInst &Inst, unsigned Val,
249                                uint64_t Address, const void *Decoder);
250 
251 static DecodeStatus DecodeBitfieldMaskOperand(MCInst &Inst, unsigned Insn,
252                                uint64_t Address, const void *Decoder);
253 static DecodeStatus DecodeCopMemInstruction(MCInst &Inst, unsigned Insn,
254                                uint64_t Address, const void *Decoder);
255 static DecodeStatus DecodeAddrMode2IdxInstruction(MCInst &Inst,
256                                                   unsigned Insn,
257                                                   uint64_t Address,
258                                                   const void *Decoder);
259 static DecodeStatus DecodeSORegMemOperand(MCInst &Inst, unsigned Insn,
260                                uint64_t Address, const void *Decoder);
261 static DecodeStatus DecodeAddrMode3Instruction(MCInst &Inst,unsigned Insn,
262                                uint64_t Address, const void *Decoder);
263 static DecodeStatus DecodeSORegImmOperand(MCInst &Inst, unsigned Insn,
264                                uint64_t Address, const void *Decoder);
265 static DecodeStatus DecodeSORegRegOperand(MCInst &Inst, unsigned Insn,
266                                uint64_t Address, const void *Decoder);
267 
268 static DecodeStatus DecodeMemMultipleWritebackInstruction(MCInst & Inst,
269                                                   unsigned Insn,
270                                                   uint64_t Adddress,
271                                                   const void *Decoder);
272 static DecodeStatus DecodeT2MOVTWInstruction(MCInst &Inst, unsigned Insn,
273                                uint64_t Address, const void *Decoder);
274 static DecodeStatus DecodeArmMOVTWInstruction(MCInst &Inst, unsigned Insn,
275                                uint64_t Address, const void *Decoder);
276 static DecodeStatus DecodeSMLAInstruction(MCInst &Inst, unsigned Insn,
277                                uint64_t Address, const void *Decoder);
278 static DecodeStatus DecodeHINTInstruction(MCInst &Inst, unsigned Insn,
279                                uint64_t Address, const void *Decoder);
280 static DecodeStatus DecodeCPSInstruction(MCInst &Inst, unsigned Insn,
281                                uint64_t Address, const void *Decoder);
282 static DecodeStatus DecodeTSTInstruction(MCInst &Inst, unsigned Insn,
283                                uint64_t Address, const void *Decoder);
284 static DecodeStatus DecodeSETPANInstruction(MCInst &Inst, unsigned Insn,
285                                uint64_t Address, const void *Decoder);
286 static DecodeStatus DecodeT2CPSInstruction(MCInst &Inst, unsigned Insn,
287                                uint64_t Address, const void *Decoder);
288 static DecodeStatus DecodeAddrModeImm12Operand(MCInst &Inst, unsigned Val,
289                                uint64_t Address, const void *Decoder);
290 static DecodeStatus DecodeAddrMode5Operand(MCInst &Inst, unsigned Val,
291                                uint64_t Address, const void *Decoder);
292 static DecodeStatus DecodeAddrMode5FP16Operand(MCInst &Inst, unsigned Val,
293                                uint64_t Address, const void *Decoder);
294 static DecodeStatus DecodeAddrMode7Operand(MCInst &Inst, unsigned Val,
295                                uint64_t Address, const void *Decoder);
296 static DecodeStatus DecodeT2BInstruction(MCInst &Inst, unsigned Insn,
297                                uint64_t Address, const void *Decoder);
298 static DecodeStatus DecodeBranchImmInstruction(MCInst &Inst,unsigned Insn,
299                                uint64_t Address, const void *Decoder);
300 static DecodeStatus DecodeAddrMode6Operand(MCInst &Inst, unsigned Val,
301                                uint64_t Address, const void *Decoder);
302 static DecodeStatus DecodeVLDST1Instruction(MCInst &Inst, unsigned Val,
303                                uint64_t Address, const void *Decoder);
304 static DecodeStatus DecodeVLDST2Instruction(MCInst &Inst, unsigned Val,
305                                uint64_t Address, const void *Decoder);
306 static DecodeStatus DecodeVLDST3Instruction(MCInst &Inst, unsigned Val,
307                                uint64_t Address, const void *Decoder);
308 static DecodeStatus DecodeVLDST4Instruction(MCInst &Inst, unsigned Val,
309                                uint64_t Address, const void *Decoder);
310 static DecodeStatus DecodeVLDInstruction(MCInst &Inst, unsigned Val,
311                                uint64_t Address, const void *Decoder);
312 static DecodeStatus DecodeVSTInstruction(MCInst &Inst, unsigned Val,
313                                uint64_t Address, const void *Decoder);
314 static DecodeStatus DecodeVLD1DupInstruction(MCInst &Inst, unsigned Val,
315                                uint64_t Address, const void *Decoder);
316 static DecodeStatus DecodeVLD2DupInstruction(MCInst &Inst, unsigned Val,
317                                uint64_t Address, const void *Decoder);
318 static DecodeStatus DecodeVLD3DupInstruction(MCInst &Inst, unsigned Val,
319                                uint64_t Address, const void *Decoder);
320 static DecodeStatus DecodeVLD4DupInstruction(MCInst &Inst, unsigned Val,
321                                uint64_t Address, const void *Decoder);
322 static DecodeStatus DecodeVMOVModImmInstruction(MCInst &Inst,unsigned Val,
323                                uint64_t Address, const void *Decoder);
324 static DecodeStatus DecodeMVEModImmInstruction(MCInst &Inst,unsigned Val,
325                                uint64_t Address, const void *Decoder);
326 static DecodeStatus DecodeMVEVADCInstruction(MCInst &Inst, unsigned Insn,
327                                uint64_t Address, const void *Decoder);
328 static DecodeStatus DecodeVSHLMaxInstruction(MCInst &Inst, unsigned Val,
329                                uint64_t Address, const void *Decoder);
330 static DecodeStatus DecodeShiftRight8Imm(MCInst &Inst, unsigned Val,
331                                uint64_t Address, const void *Decoder);
332 static DecodeStatus DecodeShiftRight16Imm(MCInst &Inst, unsigned Val,
333                                uint64_t Address, const void *Decoder);
334 static DecodeStatus DecodeShiftRight32Imm(MCInst &Inst, unsigned Val,
335                                uint64_t Address, const void *Decoder);
336 static DecodeStatus DecodeShiftRight64Imm(MCInst &Inst, unsigned Val,
337                                uint64_t Address, const void *Decoder);
338 static DecodeStatus DecodeTBLInstruction(MCInst &Inst, unsigned Insn,
339                                uint64_t Address, const void *Decoder);
340 static DecodeStatus DecodePostIdxReg(MCInst &Inst, unsigned Insn,
341                                uint64_t Address, const void *Decoder);
342 static DecodeStatus DecodeMveAddrModeRQ(MCInst &Inst, unsigned Insn,
343                                uint64_t Address, const void *Decoder);
344 template<int shift>
345 static DecodeStatus DecodeMveAddrModeQ(MCInst &Inst, unsigned Insn,
346                                uint64_t Address, const void *Decoder);
347 static DecodeStatus DecodeCoprocessor(MCInst &Inst, unsigned Insn,
348                                uint64_t Address, const void *Decoder);
349 static DecodeStatus DecodeMemBarrierOption(MCInst &Inst, unsigned Insn,
350                                uint64_t Address, const void *Decoder);
351 static DecodeStatus DecodeInstSyncBarrierOption(MCInst &Inst, unsigned Insn,
352                                uint64_t Address, const void *Decoder);
353 static DecodeStatus DecodeMSRMask(MCInst &Inst, unsigned Insn,
354                                uint64_t Address, const void *Decoder);
355 static DecodeStatus DecodeBankedReg(MCInst &Inst, unsigned Insn,
356                                uint64_t Address, const void *Decoder);
357 static DecodeStatus DecodeDoubleRegLoad(MCInst &Inst, unsigned Insn,
358                                uint64_t Address, const void *Decoder);
359 static DecodeStatus DecodeDoubleRegStore(MCInst &Inst, unsigned Insn,
360                                uint64_t Address, const void *Decoder);
361 static DecodeStatus DecodeLDRPreImm(MCInst &Inst, unsigned Insn,
362                                uint64_t Address, const void *Decoder);
363 static DecodeStatus DecodeLDRPreReg(MCInst &Inst, unsigned Insn,
364                                uint64_t Address, const void *Decoder);
365 static DecodeStatus DecodeSTRPreImm(MCInst &Inst, unsigned Insn,
366                                uint64_t Address, const void *Decoder);
367 static DecodeStatus DecodeSTRPreReg(MCInst &Inst, unsigned Insn,
368                                uint64_t Address, const void *Decoder);
369 static DecodeStatus DecodeVLD1LN(MCInst &Inst, unsigned Insn,
370                                uint64_t Address, const void *Decoder);
371 static DecodeStatus DecodeVLD2LN(MCInst &Inst, unsigned Insn,
372                                uint64_t Address, const void *Decoder);
373 static DecodeStatus DecodeVLD3LN(MCInst &Inst, unsigned Insn,
374                                uint64_t Address, const void *Decoder);
375 static DecodeStatus DecodeVLD4LN(MCInst &Inst, unsigned Insn,
376                                uint64_t Address, const void *Decoder);
377 static DecodeStatus DecodeVST1LN(MCInst &Inst, unsigned Insn,
378                                uint64_t Address, const void *Decoder);
379 static DecodeStatus DecodeVST2LN(MCInst &Inst, unsigned Insn,
380                                uint64_t Address, const void *Decoder);
381 static DecodeStatus DecodeVST3LN(MCInst &Inst, unsigned Insn,
382                                uint64_t Address, const void *Decoder);
383 static DecodeStatus DecodeVST4LN(MCInst &Inst, unsigned Insn,
384                                uint64_t Address, const void *Decoder);
385 static DecodeStatus DecodeVMOVSRR(MCInst &Inst, unsigned Insn,
386                                uint64_t Address, const void *Decoder);
387 static DecodeStatus DecodeVMOVRRS(MCInst &Inst, unsigned Insn,
388                                uint64_t Address, const void *Decoder);
389 static DecodeStatus DecodeSwap(MCInst &Inst, unsigned Insn,
390                                uint64_t Address, const void *Decoder);
391 static DecodeStatus DecodeVCVTD(MCInst &Inst, unsigned Insn,
392                                 uint64_t Address, const void *Decoder);
393 static DecodeStatus DecodeVCVTQ(MCInst &Inst, unsigned Insn,
394                                 uint64_t Address, const void *Decoder);
395 static DecodeStatus DecodeVCVTImmOperand(MCInst &Inst, unsigned Insn,
396                                          uint64_t Address, const void *Decoder);
397 static DecodeStatus DecodeNEONComplexLane64Instruction(MCInst &Inst,
398                                                        unsigned Val,
399                                                        uint64_t Address,
400                                                        const void *Decoder);
401 
402 static DecodeStatus DecodeThumbAddSpecialReg(MCInst &Inst, uint16_t Insn,
403                                uint64_t Address, const void *Decoder);
404 static DecodeStatus DecodeThumbBROperand(MCInst &Inst, unsigned Val,
405                                uint64_t Address, const void *Decoder);
406 static DecodeStatus DecodeT2BROperand(MCInst &Inst, unsigned Val,
407                                uint64_t Address, const void *Decoder);
408 static DecodeStatus DecodeThumbCmpBROperand(MCInst &Inst, unsigned Val,
409                                uint64_t Address, const void *Decoder);
410 static DecodeStatus DecodeThumbAddrModeRR(MCInst &Inst, unsigned Val,
411                                uint64_t Address, const void *Decoder);
412 static DecodeStatus DecodeThumbAddrModeIS(MCInst &Inst, unsigned Val,
413                                uint64_t Address, const void *Decoder);
414 static DecodeStatus DecodeThumbAddrModePC(MCInst &Inst, unsigned Val,
415                                uint64_t Address, const void *Decoder);
416 static DecodeStatus DecodeThumbAddrModeSP(MCInst &Inst, unsigned Val,
417                                uint64_t Address, const void *Decoder);
418 static DecodeStatus DecodeT2AddrModeSOReg(MCInst &Inst, unsigned Val,
419                                uint64_t Address, const void *Decoder);
420 static DecodeStatus DecodeT2LoadShift(MCInst &Inst, unsigned Val,
421                                uint64_t Address, const void *Decoder);
422 static DecodeStatus DecodeT2LoadImm8(MCInst &Inst, unsigned Insn,
423                                uint64_t Address, const void* Decoder);
424 static DecodeStatus DecodeT2LoadImm12(MCInst &Inst, unsigned Insn,
425                                uint64_t Address, const void* Decoder);
426 static DecodeStatus DecodeT2LoadT(MCInst &Inst, unsigned Insn,
427                                uint64_t Address, const void* Decoder);
428 static DecodeStatus DecodeT2LoadLabel(MCInst &Inst, unsigned Insn,
429                                uint64_t Address, const void* Decoder);
430 static DecodeStatus DecodeT2Imm8S4(MCInst &Inst, unsigned Val,
431                                uint64_t Address, const void *Decoder);
432 static DecodeStatus DecodeT2Imm7S4(MCInst &Inst, unsigned Val,
433                                uint64_t Address, const void *Decoder);
434 static DecodeStatus DecodeT2AddrModeImm8s4(MCInst &Inst, unsigned Val,
435                                uint64_t Address, const void *Decoder);
436 static DecodeStatus DecodeT2AddrModeImm7s4(MCInst &Inst, unsigned Val,
437                                            uint64_t Address,
438                                            const void *Decoder);
439 static DecodeStatus DecodeT2AddrModeImm0_1020s4(MCInst &Inst,unsigned Val,
440                                uint64_t Address, const void *Decoder);
441 static DecodeStatus DecodeT2Imm8(MCInst &Inst, unsigned Val,
442                                uint64_t Address, const void *Decoder);
443 template<int shift>
444 static DecodeStatus DecodeT2Imm7(MCInst &Inst, unsigned Val,
445                                uint64_t Address, const void *Decoder);
446 static DecodeStatus DecodeT2AddrModeImm8(MCInst &Inst, unsigned Val,
447                                uint64_t Address, const void *Decoder);
448 template<int shift>
449 static DecodeStatus DecodeTAddrModeImm7(MCInst &Inst, unsigned Val,
450                                uint64_t Address, const void *Decoder);
451 template<int shift, int WriteBack>
452 static DecodeStatus DecodeT2AddrModeImm7(MCInst &Inst, unsigned Val,
453                                uint64_t Address, const void *Decoder);
454 static DecodeStatus DecodeThumbAddSPImm(MCInst &Inst, uint16_t Val,
455                                uint64_t Address, const void *Decoder);
456 static DecodeStatus DecodeThumbAddSPReg(MCInst &Inst, uint16_t Insn,
457                                 uint64_t Address, const void *Decoder);
458 static DecodeStatus DecodeThumbCPS(MCInst &Inst, uint16_t Insn,
459                                 uint64_t Address, const void *Decoder);
460 static DecodeStatus DecodeQADDInstruction(MCInst &Inst, unsigned Insn,
461                                 uint64_t Address, const void *Decoder);
462 static DecodeStatus DecodeThumbBLXOffset(MCInst &Inst, unsigned Insn,
463                                 uint64_t Address, const void *Decoder);
464 static DecodeStatus DecodeT2AddrModeImm12(MCInst &Inst, unsigned Val,
465                                 uint64_t Address, const void *Decoder);
466 static DecodeStatus DecodeThumbTableBranch(MCInst &Inst, unsigned Val,
467                                 uint64_t Address, const void *Decoder);
468 static DecodeStatus DecodeThumb2BCCInstruction(MCInst &Inst, unsigned Val,
469                                 uint64_t Address, const void *Decoder);
470 static DecodeStatus DecodeT2SOImm(MCInst &Inst, unsigned Val,
471                                 uint64_t Address, const void *Decoder);
472 static DecodeStatus DecodeThumbBCCTargetOperand(MCInst &Inst,unsigned Val,
473                                 uint64_t Address, const void *Decoder);
474 static DecodeStatus DecodeThumbBLTargetOperand(MCInst &Inst, unsigned Val,
475                                 uint64_t Address, const void *Decoder);
476 static DecodeStatus DecodeIT(MCInst &Inst, unsigned Val,
477                                 uint64_t Address, const void *Decoder);
478 static DecodeStatus DecodeT2LDRDPreInstruction(MCInst &Inst,unsigned Insn,
479                                uint64_t Address, const void *Decoder);
480 static DecodeStatus DecodeT2STRDPreInstruction(MCInst &Inst,unsigned Insn,
481                                uint64_t Address, const void *Decoder);
482 static DecodeStatus DecodeT2Adr(MCInst &Inst, unsigned Val,
483                                 uint64_t Address, const void *Decoder);
484 static DecodeStatus DecodeT2LdStPre(MCInst &Inst, unsigned Val,
485                                 uint64_t Address, const void *Decoder);
486 static DecodeStatus DecodeT2ShifterImmOperand(MCInst &Inst, unsigned Val,
487                                 uint64_t Address, const void *Decoder);
488 
489 static DecodeStatus DecodeLDR(MCInst &Inst, unsigned Val,
490                                 uint64_t Address, const void *Decoder);
491 static DecodeStatus DecoderForMRRC2AndMCRR2(MCInst &Inst, unsigned Val,
492                                             uint64_t Address, const void *Decoder);
493 static DecodeStatus DecodeForVMRSandVMSR(MCInst &Inst, unsigned Val,
494                                          uint64_t Address, const void *Decoder);
495 
496 template <bool isSigned, bool isNeg, bool zeroPermitted, int size>
497 static DecodeStatus DecodeBFLabelOperand(MCInst &Inst, unsigned val,
498                                          uint64_t Address, const void *Decoder);
499 static DecodeStatus DecodeBFAfterTargetOperand(MCInst &Inst, unsigned val,
500                                                uint64_t Address,
501                                                const void *Decoder);
502 static DecodeStatus DecodePredNoALOperand(MCInst &Inst, unsigned Val,
503                                           uint64_t Address,
504                                           const void *Decoder);
505 static DecodeStatus DecodeLOLoop(MCInst &Inst, unsigned Insn, uint64_t Address,
506                                  const void *Decoder);
507 static DecodeStatus DecodeLongShiftOperand(MCInst &Inst, unsigned Val,
508                                            uint64_t Address,
509                                            const void *Decoder);
510 static DecodeStatus DecodeVSCCLRM(MCInst &Inst, unsigned Insn, uint64_t Address,
511                                   const void *Decoder);
512 static DecodeStatus DecodeVPTMaskOperand(MCInst &Inst, unsigned Val,
513                                          uint64_t Address, const void *Decoder);
514 static DecodeStatus DecodeVpredROperand(MCInst &Inst, unsigned Val,
515                                         uint64_t Address, const void *Decoder);
516 static DecodeStatus DecodeRestrictedIPredicateOperand(MCInst &Inst, unsigned Val,
517                                                      uint64_t Address,
518                                                      const void *Decoder);
519 static DecodeStatus DecodeRestrictedSPredicateOperand(MCInst &Inst, unsigned Val,
520                                                      uint64_t Address,
521                                                      const void *Decoder);
522 static DecodeStatus DecodeRestrictedUPredicateOperand(MCInst &Inst, unsigned Val,
523                                                      uint64_t Address,
524                                                      const void *Decoder);
525 static DecodeStatus DecodeRestrictedFPPredicateOperand(MCInst &Inst,
526                                                        unsigned Val,
527                                                        uint64_t Address,
528                                                        const void *Decoder);
529 template<bool Writeback>
530 static DecodeStatus DecodeVSTRVLDR_SYSREG(MCInst &Inst, unsigned Insn,
531                                           uint64_t Address,
532                                           const void *Decoder);
533 template<int shift>
534 static DecodeStatus DecodeMVE_MEM_1_pre(MCInst &Inst, unsigned Val,
535                                         uint64_t Address, const void *Decoder);
536 template<int shift>
537 static DecodeStatus DecodeMVE_MEM_2_pre(MCInst &Inst, unsigned Val,
538                                         uint64_t Address, const void *Decoder);
539 template<int shift>
540 static DecodeStatus DecodeMVE_MEM_3_pre(MCInst &Inst, unsigned Val,
541                                         uint64_t Address, const void *Decoder);
542 template<unsigned MinLog, unsigned MaxLog>
543 static DecodeStatus DecodePowerTwoOperand(MCInst &Inst, unsigned Val,
544                                           uint64_t Address,
545                                           const void *Decoder);
546 template<unsigned start>
547 static DecodeStatus DecodeMVEPairVectorIndexOperand(MCInst &Inst, unsigned Val,
548                                                     uint64_t Address,
549                                                     const void *Decoder);
550 static DecodeStatus DecodeMVEVMOVQtoDReg(MCInst &Inst, unsigned Insn,
551                                          uint64_t Address,
552                                          const void *Decoder);
553 static DecodeStatus DecodeMVEVMOVDRegtoQ(MCInst &Inst, unsigned Insn,
554                                          uint64_t Address,
555                                          const void *Decoder);
556 static DecodeStatus DecodeMVEVCVTt1fp(MCInst &Inst, unsigned Insn,
557                                       uint64_t Address, const void *Decoder);
558 typedef DecodeStatus OperandDecoder(MCInst &Inst, unsigned Val,
559                                     uint64_t Address, const void *Decoder);
560 template<bool scalar, OperandDecoder predicate_decoder>
561 static DecodeStatus DecodeMVEVCMP(MCInst &Inst, unsigned Insn,
562                                   uint64_t Address, const void *Decoder);
563 static DecodeStatus DecodeMveVCTP(MCInst &Inst, unsigned Insn,
564                                   uint64_t Address, const void *Decoder);
565 static DecodeStatus DecodeMVEVPNOT(MCInst &Inst, unsigned Insn,
566                                    uint64_t Address, const void *Decoder);
567 static DecodeStatus DecodeMVEOverlappingLongShift(MCInst &Inst, unsigned Insn,
568                                                   uint64_t Address,
569                                                   const void *Decoder);
570 static DecodeStatus DecodeT2AddSubSPImm(MCInst &Inst, unsigned Insn,
571                                         uint64_t Address, const void *Decoder);
572 
573 #include "ARMGenDisassemblerTables.inc"
574 
575 static MCDisassembler *createARMDisassembler(const Target &T,
576                                              const MCSubtargetInfo &STI,
577                                              MCContext &Ctx) {
578   return new ARMDisassembler(STI, Ctx);
579 }
580 
581 // Post-decoding checks
582 static DecodeStatus checkDecodedInstruction(MCInst &MI, uint64_t &Size,
583                                             uint64_t Address, raw_ostream &CS,
584                                             uint32_t Insn,
585                                             DecodeStatus Result) {
586   switch (MI.getOpcode()) {
587     case ARM::HVC: {
588       // HVC is undefined if condition = 0xf otherwise upredictable
589       // if condition != 0xe
590       uint32_t Cond = (Insn >> 28) & 0xF;
591       if (Cond == 0xF)
592         return MCDisassembler::Fail;
593       if (Cond != 0xE)
594         return MCDisassembler::SoftFail;
595       return Result;
596     }
597     case ARM::t2ADDri:
598     case ARM::t2ADDri12:
599     case ARM::t2ADDrr:
600     case ARM::t2ADDrs:
601     case ARM::t2SUBri:
602     case ARM::t2SUBri12:
603     case ARM::t2SUBrr:
604     case ARM::t2SUBrs:
605       if (MI.getOperand(0).getReg() == ARM::SP &&
606           MI.getOperand(1).getReg() != ARM::SP)
607         return MCDisassembler::SoftFail;
608       return Result;
609     default: return Result;
610   }
611 }
612 
613 DecodeStatus ARMDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
614                                              ArrayRef<uint8_t> Bytes,
615                                              uint64_t Address,
616                                              raw_ostream &CS) const {
617   if (STI.getFeatureBits()[ARM::ModeThumb])
618     return getThumbInstruction(MI, Size, Bytes, Address, CS);
619   return getARMInstruction(MI, Size, Bytes, Address, CS);
620 }
621 
622 DecodeStatus ARMDisassembler::getARMInstruction(MCInst &MI, uint64_t &Size,
623                                                 ArrayRef<uint8_t> Bytes,
624                                                 uint64_t Address,
625                                                 raw_ostream &CS) const {
626   CommentStream = &CS;
627 
628   assert(!STI.getFeatureBits()[ARM::ModeThumb] &&
629          "Asked to disassemble an ARM instruction but Subtarget is in Thumb "
630          "mode!");
631 
632   // We want to read exactly 4 bytes of data.
633   if (Bytes.size() < 4) {
634     Size = 0;
635     return MCDisassembler::Fail;
636   }
637 
638   // Encoded as a small-endian 32-bit word in the stream.
639   uint32_t Insn =
640       (Bytes[3] << 24) | (Bytes[2] << 16) | (Bytes[1] << 8) | (Bytes[0] << 0);
641 
642   // Calling the auto-generated decoder function.
643   DecodeStatus Result =
644       decodeInstruction(DecoderTableARM32, MI, Insn, Address, this, STI);
645   if (Result != MCDisassembler::Fail) {
646     Size = 4;
647     return checkDecodedInstruction(MI, Size, Address, CS, Insn, Result);
648   }
649 
650   struct DecodeTable {
651     const uint8_t *P;
652     bool DecodePred;
653   };
654 
655   const DecodeTable Tables[] = {
656       {DecoderTableVFP32, false},      {DecoderTableVFPV832, false},
657       {DecoderTableNEONData32, true},  {DecoderTableNEONLoadStore32, true},
658       {DecoderTableNEONDup32, true},   {DecoderTablev8NEON32, false},
659       {DecoderTablev8Crypto32, false},
660   };
661 
662   for (auto Table : Tables) {
663     Result = decodeInstruction(Table.P, MI, Insn, Address, this, STI);
664     if (Result != MCDisassembler::Fail) {
665       Size = 4;
666       // Add a fake predicate operand, because we share these instruction
667       // definitions with Thumb2 where these instructions are predicable.
668       if (Table.DecodePred && !DecodePredicateOperand(MI, 0xE, Address, this))
669         return MCDisassembler::Fail;
670       return Result;
671     }
672   }
673 
674   Result =
675       decodeInstruction(DecoderTableCoProc32, MI, Insn, Address, this, STI);
676   if (Result != MCDisassembler::Fail) {
677     Size = 4;
678     return checkDecodedInstruction(MI, Size, Address, CS, Insn, Result);
679   }
680 
681   Size = 4;
682   return MCDisassembler::Fail;
683 }
684 
685 namespace llvm {
686 
687 extern const MCInstrDesc ARMInsts[];
688 
689 } // end namespace llvm
690 
691 /// tryAddingSymbolicOperand - trys to add a symbolic operand in place of the
692 /// immediate Value in the MCInst.  The immediate Value has had any PC
693 /// adjustment made by the caller.  If the instruction is a branch instruction
694 /// then isBranch is true, else false.  If the getOpInfo() function was set as
695 /// part of the setupForSymbolicDisassembly() call then that function is called
696 /// to get any symbolic information at the Address for this instruction.  If
697 /// that returns non-zero then the symbolic information it returns is used to
698 /// create an MCExpr and that is added as an operand to the MCInst.  If
699 /// getOpInfo() returns zero and isBranch is true then a symbol look up for
700 /// Value is done and if a symbol is found an MCExpr is created with that, else
701 /// an MCExpr with Value is created.  This function returns true if it adds an
702 /// operand to the MCInst and false otherwise.
703 static bool tryAddingSymbolicOperand(uint64_t Address, int32_t Value,
704                                      bool isBranch, uint64_t InstSize,
705                                      MCInst &MI, const void *Decoder) {
706   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
707   // FIXME: Does it make sense for value to be negative?
708   return Dis->tryAddingSymbolicOperand(MI, (uint32_t)Value, Address, isBranch,
709                                        /* Offset */ 0, InstSize);
710 }
711 
712 /// tryAddingPcLoadReferenceComment - trys to add a comment as to what is being
713 /// referenced by a load instruction with the base register that is the Pc.
714 /// These can often be values in a literal pool near the Address of the
715 /// instruction.  The Address of the instruction and its immediate Value are
716 /// used as a possible literal pool entry.  The SymbolLookUp call back will
717 /// return the name of a symbol referenced by the literal pool's entry if
718 /// the referenced address is that of a symbol.  Or it will return a pointer to
719 /// a literal 'C' string if the referenced address of the literal pool's entry
720 /// is an address into a section with 'C' string literals.
721 static void tryAddingPcLoadReferenceComment(uint64_t Address, int Value,
722                                             const void *Decoder) {
723   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
724   Dis->tryAddingPcLoadReferenceComment(Value, Address);
725 }
726 
727 // Thumb1 instructions don't have explicit S bits.  Rather, they
728 // implicitly set CPSR.  Since it's not represented in the encoding, the
729 // auto-generated decoder won't inject the CPSR operand.  We need to fix
730 // that as a post-pass.
731 static void AddThumb1SBit(MCInst &MI, bool InITBlock) {
732   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
733   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
734   MCInst::iterator I = MI.begin();
735   for (unsigned i = 0; i < NumOps; ++i, ++I) {
736     if (I == MI.end()) break;
737     if (OpInfo[i].isOptionalDef() && OpInfo[i].RegClass == ARM::CCRRegClassID) {
738       if (i > 0 && OpInfo[i-1].isPredicate()) continue;
739       MI.insert(I, MCOperand::createReg(InITBlock ? 0 : ARM::CPSR));
740       return;
741     }
742   }
743 
744   MI.insert(I, MCOperand::createReg(InITBlock ? 0 : ARM::CPSR));
745 }
746 
747 static bool isVectorPredicable(unsigned Opcode) {
748   const MCOperandInfo *OpInfo = ARMInsts[Opcode].OpInfo;
749   unsigned short NumOps = ARMInsts[Opcode].NumOperands;
750   for (unsigned i = 0; i < NumOps; ++i) {
751     if (ARM::isVpred(OpInfo[i].OperandType))
752       return true;
753   }
754   return false;
755 }
756 
757 // Most Thumb instructions don't have explicit predicates in the
758 // encoding, but rather get their predicates from IT context.  We need
759 // to fix up the predicate operands using this context information as a
760 // post-pass.
761 MCDisassembler::DecodeStatus
762 ARMDisassembler::AddThumbPredicate(MCInst &MI) const {
763   MCDisassembler::DecodeStatus S = Success;
764 
765   const FeatureBitset &FeatureBits = getSubtargetInfo().getFeatureBits();
766 
767   // A few instructions actually have predicates encoded in them.  Don't
768   // try to overwrite it if we're seeing one of those.
769   switch (MI.getOpcode()) {
770     case ARM::tBcc:
771     case ARM::t2Bcc:
772     case ARM::tCBZ:
773     case ARM::tCBNZ:
774     case ARM::tCPS:
775     case ARM::t2CPS3p:
776     case ARM::t2CPS2p:
777     case ARM::t2CPS1p:
778     case ARM::t2CSEL:
779     case ARM::t2CSINC:
780     case ARM::t2CSINV:
781     case ARM::t2CSNEG:
782     case ARM::tMOVSr:
783     case ARM::tSETEND:
784       // Some instructions (mostly conditional branches) are not
785       // allowed in IT blocks.
786       if (ITBlock.instrInITBlock())
787         S = SoftFail;
788       else
789         return Success;
790       break;
791     case ARM::t2HINT:
792       if (MI.getOperand(0).getImm() == 0x10 && (FeatureBits[ARM::FeatureRAS]) != 0)
793         S = SoftFail;
794       break;
795     case ARM::tB:
796     case ARM::t2B:
797     case ARM::t2TBB:
798     case ARM::t2TBH:
799       // Some instructions (mostly unconditional branches) can
800       // only appears at the end of, or outside of, an IT.
801       if (ITBlock.instrInITBlock() && !ITBlock.instrLastInITBlock())
802         S = SoftFail;
803       break;
804     default:
805       break;
806   }
807 
808   // Warn on non-VPT predicable instruction in a VPT block and a VPT
809   // predicable instruction in an IT block
810   if ((!isVectorPredicable(MI.getOpcode()) && VPTBlock.instrInVPTBlock()) ||
811        (isVectorPredicable(MI.getOpcode()) && ITBlock.instrInITBlock()))
812     S = SoftFail;
813 
814   // If we're in an IT/VPT block, base the predicate on that.  Otherwise,
815   // assume a predicate of AL.
816   unsigned CC = ARMCC::AL;
817   unsigned VCC = ARMVCC::None;
818   if (ITBlock.instrInITBlock()) {
819     CC = ITBlock.getITCC();
820     ITBlock.advanceITState();
821   } else if (VPTBlock.instrInVPTBlock()) {
822     VCC = VPTBlock.getVPTPred();
823     VPTBlock.advanceVPTState();
824   }
825 
826   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
827   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
828 
829   MCInst::iterator CCI = MI.begin();
830   for (unsigned i = 0; i < NumOps; ++i, ++CCI) {
831     if (OpInfo[i].isPredicate() || CCI == MI.end()) break;
832   }
833 
834   if (ARMInsts[MI.getOpcode()].isPredicable()) {
835     CCI = MI.insert(CCI, MCOperand::createImm(CC));
836     ++CCI;
837     if (CC == ARMCC::AL)
838       MI.insert(CCI, MCOperand::createReg(0));
839     else
840       MI.insert(CCI, MCOperand::createReg(ARM::CPSR));
841   } else if (CC != ARMCC::AL) {
842     Check(S, SoftFail);
843   }
844 
845   MCInst::iterator VCCI = MI.begin();
846   unsigned VCCPos;
847   for (VCCPos = 0; VCCPos < NumOps; ++VCCPos, ++VCCI) {
848     if (ARM::isVpred(OpInfo[VCCPos].OperandType) || VCCI == MI.end()) break;
849   }
850 
851   if (isVectorPredicable(MI.getOpcode())) {
852     VCCI = MI.insert(VCCI, MCOperand::createImm(VCC));
853     ++VCCI;
854     if (VCC == ARMVCC::None)
855       MI.insert(VCCI, MCOperand::createReg(0));
856     else
857       MI.insert(VCCI, MCOperand::createReg(ARM::P0));
858     if (OpInfo[VCCPos].OperandType == ARM::OPERAND_VPRED_R) {
859       int TiedOp = ARMInsts[MI.getOpcode()].getOperandConstraint(
860         VCCPos + 2, MCOI::TIED_TO);
861       assert(TiedOp >= 0 &&
862              "Inactive register in vpred_r is not tied to an output!");
863       // Copy the operand to ensure it's not invalidated when MI grows.
864       MI.insert(VCCI, MCOperand(MI.getOperand(TiedOp)));
865     }
866   } else if (VCC != ARMVCC::None) {
867     Check(S, SoftFail);
868   }
869 
870   return S;
871 }
872 
873 // Thumb VFP instructions are a special case.  Because we share their
874 // encodings between ARM and Thumb modes, and they are predicable in ARM
875 // mode, the auto-generated decoder will give them an (incorrect)
876 // predicate operand.  We need to rewrite these operands based on the IT
877 // context as a post-pass.
878 void ARMDisassembler::UpdateThumbVFPPredicate(
879   DecodeStatus &S, MCInst &MI) const {
880   unsigned CC;
881   CC = ITBlock.getITCC();
882   if (CC == 0xF)
883     CC = ARMCC::AL;
884   if (ITBlock.instrInITBlock())
885     ITBlock.advanceITState();
886   else if (VPTBlock.instrInVPTBlock()) {
887     CC = VPTBlock.getVPTPred();
888     VPTBlock.advanceVPTState();
889   }
890 
891   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
892   MCInst::iterator I = MI.begin();
893   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
894   for (unsigned i = 0; i < NumOps; ++i, ++I) {
895     if (OpInfo[i].isPredicate() ) {
896       if (CC != ARMCC::AL && !ARMInsts[MI.getOpcode()].isPredicable())
897         Check(S, SoftFail);
898       I->setImm(CC);
899       ++I;
900       if (CC == ARMCC::AL)
901         I->setReg(0);
902       else
903         I->setReg(ARM::CPSR);
904       return;
905     }
906   }
907 }
908 
909 DecodeStatus ARMDisassembler::getThumbInstruction(MCInst &MI, uint64_t &Size,
910                                                   ArrayRef<uint8_t> Bytes,
911                                                   uint64_t Address,
912                                                   raw_ostream &CS) const {
913   CommentStream = &CS;
914 
915   assert(STI.getFeatureBits()[ARM::ModeThumb] &&
916          "Asked to disassemble in Thumb mode but Subtarget is in ARM mode!");
917 
918   // We want to read exactly 2 bytes of data.
919   if (Bytes.size() < 2) {
920     Size = 0;
921     return MCDisassembler::Fail;
922   }
923 
924   uint16_t Insn16 = (Bytes[1] << 8) | Bytes[0];
925   DecodeStatus Result =
926       decodeInstruction(DecoderTableThumb16, MI, Insn16, Address, this, STI);
927   if (Result != MCDisassembler::Fail) {
928     Size = 2;
929     Check(Result, AddThumbPredicate(MI));
930     return Result;
931   }
932 
933   Result = decodeInstruction(DecoderTableThumbSBit16, MI, Insn16, Address, this,
934                              STI);
935   if (Result) {
936     Size = 2;
937     bool InITBlock = ITBlock.instrInITBlock();
938     Check(Result, AddThumbPredicate(MI));
939     AddThumb1SBit(MI, InITBlock);
940     return Result;
941   }
942 
943   Result =
944       decodeInstruction(DecoderTableThumb216, MI, Insn16, Address, this, STI);
945   if (Result != MCDisassembler::Fail) {
946     Size = 2;
947 
948     // Nested IT blocks are UNPREDICTABLE.  Must be checked before we add
949     // the Thumb predicate.
950     if (MI.getOpcode() == ARM::t2IT && ITBlock.instrInITBlock())
951       Result = MCDisassembler::SoftFail;
952 
953     Check(Result, AddThumbPredicate(MI));
954 
955     // If we find an IT instruction, we need to parse its condition
956     // code and mask operands so that we can apply them correctly
957     // to the subsequent instructions.
958     if (MI.getOpcode() == ARM::t2IT) {
959       unsigned Firstcond = MI.getOperand(0).getImm();
960       unsigned Mask = MI.getOperand(1).getImm();
961       ITBlock.setITState(Firstcond, Mask);
962 
963       // An IT instruction that would give a 'NV' predicate is unpredictable.
964       if (Firstcond == ARMCC::AL && !isPowerOf2_32(Mask))
965         CS << "unpredictable IT predicate sequence";
966     }
967 
968     return Result;
969   }
970 
971   // We want to read exactly 4 bytes of data.
972   if (Bytes.size() < 4) {
973     Size = 0;
974     return MCDisassembler::Fail;
975   }
976 
977   uint32_t Insn32 =
978       (Bytes[3] << 8) | (Bytes[2] << 0) | (Bytes[1] << 24) | (Bytes[0] << 16);
979 
980   Result =
981       decodeInstruction(DecoderTableMVE32, MI, Insn32, Address, this, STI);
982   if (Result != MCDisassembler::Fail) {
983     Size = 4;
984 
985     // Nested VPT blocks are UNPREDICTABLE. Must be checked before we add
986     // the VPT predicate.
987     if (isVPTOpcode(MI.getOpcode()) && VPTBlock.instrInVPTBlock())
988       Result = MCDisassembler::SoftFail;
989 
990     Check(Result, AddThumbPredicate(MI));
991 
992     if (isVPTOpcode(MI.getOpcode())) {
993       unsigned Mask = MI.getOperand(0).getImm();
994       VPTBlock.setVPTState(Mask);
995     }
996 
997     return Result;
998   }
999 
1000   Result =
1001       decodeInstruction(DecoderTableThumb32, MI, Insn32, Address, this, STI);
1002   if (Result != MCDisassembler::Fail) {
1003     Size = 4;
1004     bool InITBlock = ITBlock.instrInITBlock();
1005     Check(Result, AddThumbPredicate(MI));
1006     AddThumb1SBit(MI, InITBlock);
1007     return Result;
1008   }
1009 
1010   Result =
1011       decodeInstruction(DecoderTableThumb232, MI, Insn32, Address, this, STI);
1012   if (Result != MCDisassembler::Fail) {
1013     Size = 4;
1014     Check(Result, AddThumbPredicate(MI));
1015     return checkDecodedInstruction(MI, Size, Address, CS, Insn32, Result);
1016   }
1017 
1018   if (fieldFromInstruction(Insn32, 28, 4) == 0xE) {
1019     Result =
1020         decodeInstruction(DecoderTableVFP32, MI, Insn32, Address, this, STI);
1021     if (Result != MCDisassembler::Fail) {
1022       Size = 4;
1023       UpdateThumbVFPPredicate(Result, MI);
1024       return Result;
1025     }
1026   }
1027 
1028   Result =
1029       decodeInstruction(DecoderTableVFPV832, MI, Insn32, Address, this, STI);
1030   if (Result != MCDisassembler::Fail) {
1031     Size = 4;
1032     return Result;
1033   }
1034 
1035   if (fieldFromInstruction(Insn32, 28, 4) == 0xE) {
1036     Result = decodeInstruction(DecoderTableNEONDup32, MI, Insn32, Address, this,
1037                                STI);
1038     if (Result != MCDisassembler::Fail) {
1039       Size = 4;
1040       Check(Result, AddThumbPredicate(MI));
1041       return Result;
1042     }
1043   }
1044 
1045   if (fieldFromInstruction(Insn32, 24, 8) == 0xF9) {
1046     uint32_t NEONLdStInsn = Insn32;
1047     NEONLdStInsn &= 0xF0FFFFFF;
1048     NEONLdStInsn |= 0x04000000;
1049     Result = decodeInstruction(DecoderTableNEONLoadStore32, MI, NEONLdStInsn,
1050                                Address, this, STI);
1051     if (Result != MCDisassembler::Fail) {
1052       Size = 4;
1053       Check(Result, AddThumbPredicate(MI));
1054       return Result;
1055     }
1056   }
1057 
1058   if (fieldFromInstruction(Insn32, 24, 4) == 0xF) {
1059     uint32_t NEONDataInsn = Insn32;
1060     NEONDataInsn &= 0xF0FFFFFF; // Clear bits 27-24
1061     NEONDataInsn |= (NEONDataInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
1062     NEONDataInsn |= 0x12000000; // Set bits 28 and 25
1063     Result = decodeInstruction(DecoderTableNEONData32, MI, NEONDataInsn,
1064                                Address, this, STI);
1065     if (Result != MCDisassembler::Fail) {
1066       Size = 4;
1067       Check(Result, AddThumbPredicate(MI));
1068       return Result;
1069     }
1070 
1071     uint32_t NEONCryptoInsn = Insn32;
1072     NEONCryptoInsn &= 0xF0FFFFFF; // Clear bits 27-24
1073     NEONCryptoInsn |= (NEONCryptoInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
1074     NEONCryptoInsn |= 0x12000000; // Set bits 28 and 25
1075     Result = decodeInstruction(DecoderTablev8Crypto32, MI, NEONCryptoInsn,
1076                                Address, this, STI);
1077     if (Result != MCDisassembler::Fail) {
1078       Size = 4;
1079       return Result;
1080     }
1081 
1082     uint32_t NEONv8Insn = Insn32;
1083     NEONv8Insn &= 0xF3FFFFFF; // Clear bits 27-26
1084     Result = decodeInstruction(DecoderTablev8NEON32, MI, NEONv8Insn, Address,
1085                                this, STI);
1086     if (Result != MCDisassembler::Fail) {
1087       Size = 4;
1088       return Result;
1089     }
1090   }
1091 
1092   uint32_t Coproc = fieldFromInstruction(Insn32, 8, 4);
1093   const uint8_t *DecoderTable = ARM::isCDECoproc(Coproc, STI)
1094                                     ? DecoderTableThumb2CDE32
1095                                     : DecoderTableThumb2CoProc32;
1096   Result =
1097       decodeInstruction(DecoderTable, MI, Insn32, Address, this, STI);
1098   if (Result != MCDisassembler::Fail) {
1099     Size = 4;
1100     Check(Result, AddThumbPredicate(MI));
1101     return Result;
1102   }
1103 
1104   Size = 0;
1105   return MCDisassembler::Fail;
1106 }
1107 
1108 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeARMDisassembler() {
1109   TargetRegistry::RegisterMCDisassembler(getTheARMLETarget(),
1110                                          createARMDisassembler);
1111   TargetRegistry::RegisterMCDisassembler(getTheARMBETarget(),
1112                                          createARMDisassembler);
1113   TargetRegistry::RegisterMCDisassembler(getTheThumbLETarget(),
1114                                          createARMDisassembler);
1115   TargetRegistry::RegisterMCDisassembler(getTheThumbBETarget(),
1116                                          createARMDisassembler);
1117 }
1118 
1119 static const uint16_t GPRDecoderTable[] = {
1120   ARM::R0, ARM::R1, ARM::R2, ARM::R3,
1121   ARM::R4, ARM::R5, ARM::R6, ARM::R7,
1122   ARM::R8, ARM::R9, ARM::R10, ARM::R11,
1123   ARM::R12, ARM::SP, ARM::LR, ARM::PC
1124 };
1125 
1126 static const uint16_t CLRMGPRDecoderTable[] = {
1127   ARM::R0, ARM::R1, ARM::R2, ARM::R3,
1128   ARM::R4, ARM::R5, ARM::R6, ARM::R7,
1129   ARM::R8, ARM::R9, ARM::R10, ARM::R11,
1130   ARM::R12, 0, ARM::LR, ARM::APSR
1131 };
1132 
1133 static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1134                                    uint64_t Address, const void *Decoder) {
1135   if (RegNo > 15)
1136     return MCDisassembler::Fail;
1137 
1138   unsigned Register = GPRDecoderTable[RegNo];
1139   Inst.addOperand(MCOperand::createReg(Register));
1140   return MCDisassembler::Success;
1141 }
1142 
1143 static DecodeStatus DecodeCLRMGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1144                                                uint64_t Address,
1145                                                const void *Decoder) {
1146   if (RegNo > 15)
1147     return MCDisassembler::Fail;
1148 
1149   unsigned Register = CLRMGPRDecoderTable[RegNo];
1150   if (Register == 0)
1151     return MCDisassembler::Fail;
1152 
1153   Inst.addOperand(MCOperand::createReg(Register));
1154   return MCDisassembler::Success;
1155 }
1156 
1157 static DecodeStatus
1158 DecodeGPRnopcRegisterClass(MCInst &Inst, unsigned RegNo,
1159                            uint64_t Address, const void *Decoder) {
1160   DecodeStatus S = MCDisassembler::Success;
1161 
1162   if (RegNo == 15)
1163     S = MCDisassembler::SoftFail;
1164 
1165   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1166 
1167   return S;
1168 }
1169 
1170 static DecodeStatus
1171 DecodeGPRwithAPSRRegisterClass(MCInst &Inst, unsigned RegNo,
1172                                uint64_t Address, const void *Decoder) {
1173   DecodeStatus S = MCDisassembler::Success;
1174 
1175   if (RegNo == 15)
1176   {
1177     Inst.addOperand(MCOperand::createReg(ARM::APSR_NZCV));
1178     return MCDisassembler::Success;
1179   }
1180 
1181   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1182   return S;
1183 }
1184 
1185 static DecodeStatus
1186 DecodeGPRwithZRRegisterClass(MCInst &Inst, unsigned RegNo,
1187                              uint64_t Address, const void *Decoder) {
1188   DecodeStatus S = MCDisassembler::Success;
1189 
1190   if (RegNo == 15)
1191   {
1192     Inst.addOperand(MCOperand::createReg(ARM::ZR));
1193     return MCDisassembler::Success;
1194   }
1195 
1196   if (RegNo == 13)
1197     Check(S, MCDisassembler::SoftFail);
1198 
1199   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1200   return S;
1201 }
1202 
1203 static DecodeStatus
1204 DecodeGPRwithZRnospRegisterClass(MCInst &Inst, unsigned RegNo,
1205                                  uint64_t Address, const void *Decoder) {
1206   DecodeStatus S = MCDisassembler::Success;
1207   if (RegNo == 13)
1208     return MCDisassembler::Fail;
1209   Check(S, DecodeGPRwithZRRegisterClass(Inst, RegNo, Address, Decoder));
1210   return S;
1211 }
1212 
1213 static DecodeStatus DecodetGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1214                                    uint64_t Address, const void *Decoder) {
1215   if (RegNo > 7)
1216     return MCDisassembler::Fail;
1217   return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
1218 }
1219 
1220 static const uint16_t GPRPairDecoderTable[] = {
1221   ARM::R0_R1, ARM::R2_R3,   ARM::R4_R5,  ARM::R6_R7,
1222   ARM::R8_R9, ARM::R10_R11, ARM::R12_SP
1223 };
1224 
1225 static DecodeStatus DecodeGPRPairRegisterClass(MCInst &Inst, unsigned RegNo,
1226                                    uint64_t Address, const void *Decoder) {
1227   DecodeStatus S = MCDisassembler::Success;
1228 
1229   // According to the Arm ARM RegNo = 14 is undefined, but we return fail
1230   // rather than SoftFail as there is no GPRPair table entry for index 7.
1231   if (RegNo > 13)
1232     return MCDisassembler::Fail;
1233 
1234   if (RegNo & 1)
1235      S = MCDisassembler::SoftFail;
1236 
1237   unsigned RegisterPair = GPRPairDecoderTable[RegNo/2];
1238   Inst.addOperand(MCOperand::createReg(RegisterPair));
1239   return S;
1240 }
1241 
1242 static DecodeStatus DecodeGPRPairnospRegisterClass(MCInst &Inst, unsigned RegNo,
1243                                    uint64_t Address, const void *Decoder) {
1244   if (RegNo > 13)
1245     return MCDisassembler::Fail;
1246 
1247   unsigned RegisterPair = GPRPairDecoderTable[RegNo/2];
1248   Inst.addOperand(MCOperand::createReg(RegisterPair));
1249 
1250   if ((RegNo & 1) || RegNo > 10)
1251      return MCDisassembler::SoftFail;
1252   return MCDisassembler::Success;
1253 }
1254 
1255 static DecodeStatus DecodeGPRspRegisterClass(MCInst &Inst, unsigned RegNo,
1256                                              uint64_t Address,
1257                                              const void *Decoder) {
1258   if (RegNo != 13)
1259     return MCDisassembler::Fail;
1260 
1261   unsigned Register = GPRDecoderTable[RegNo];
1262   Inst.addOperand(MCOperand::createReg(Register));
1263   return MCDisassembler::Success;
1264 }
1265 
1266 static DecodeStatus DecodetcGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1267                                    uint64_t Address, const void *Decoder) {
1268   unsigned Register = 0;
1269   switch (RegNo) {
1270     case 0:
1271       Register = ARM::R0;
1272       break;
1273     case 1:
1274       Register = ARM::R1;
1275       break;
1276     case 2:
1277       Register = ARM::R2;
1278       break;
1279     case 3:
1280       Register = ARM::R3;
1281       break;
1282     case 9:
1283       Register = ARM::R9;
1284       break;
1285     case 12:
1286       Register = ARM::R12;
1287       break;
1288     default:
1289       return MCDisassembler::Fail;
1290     }
1291 
1292   Inst.addOperand(MCOperand::createReg(Register));
1293   return MCDisassembler::Success;
1294 }
1295 
1296 static DecodeStatus DecoderGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1297                                    uint64_t Address, const void *Decoder) {
1298   DecodeStatus S = MCDisassembler::Success;
1299 
1300   const FeatureBitset &featureBits =
1301     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1302 
1303   if ((RegNo == 13 && !featureBits[ARM::HasV8Ops]) || RegNo == 15)
1304     S = MCDisassembler::SoftFail;
1305 
1306   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1307   return S;
1308 }
1309 
1310 static const uint16_t SPRDecoderTable[] = {
1311      ARM::S0,  ARM::S1,  ARM::S2,  ARM::S3,
1312      ARM::S4,  ARM::S5,  ARM::S6,  ARM::S7,
1313      ARM::S8,  ARM::S9, ARM::S10, ARM::S11,
1314     ARM::S12, ARM::S13, ARM::S14, ARM::S15,
1315     ARM::S16, ARM::S17, ARM::S18, ARM::S19,
1316     ARM::S20, ARM::S21, ARM::S22, ARM::S23,
1317     ARM::S24, ARM::S25, ARM::S26, ARM::S27,
1318     ARM::S28, ARM::S29, ARM::S30, ARM::S31
1319 };
1320 
1321 static DecodeStatus DecodeSPRRegisterClass(MCInst &Inst, unsigned RegNo,
1322                                    uint64_t Address, const void *Decoder) {
1323   if (RegNo > 31)
1324     return MCDisassembler::Fail;
1325 
1326   unsigned Register = SPRDecoderTable[RegNo];
1327   Inst.addOperand(MCOperand::createReg(Register));
1328   return MCDisassembler::Success;
1329 }
1330 
1331 static DecodeStatus DecodeHPRRegisterClass(MCInst &Inst, unsigned RegNo,
1332                                    uint64_t Address, const void *Decoder) {
1333   return DecodeSPRRegisterClass(Inst, RegNo, Address, Decoder);
1334 }
1335 
1336 static const uint16_t DPRDecoderTable[] = {
1337      ARM::D0,  ARM::D1,  ARM::D2,  ARM::D3,
1338      ARM::D4,  ARM::D5,  ARM::D6,  ARM::D7,
1339      ARM::D8,  ARM::D9, ARM::D10, ARM::D11,
1340     ARM::D12, ARM::D13, ARM::D14, ARM::D15,
1341     ARM::D16, ARM::D17, ARM::D18, ARM::D19,
1342     ARM::D20, ARM::D21, ARM::D22, ARM::D23,
1343     ARM::D24, ARM::D25, ARM::D26, ARM::D27,
1344     ARM::D28, ARM::D29, ARM::D30, ARM::D31
1345 };
1346 
1347 static DecodeStatus DecodeDPRRegisterClass(MCInst &Inst, unsigned RegNo,
1348                                    uint64_t Address, const void *Decoder) {
1349   const FeatureBitset &featureBits =
1350     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1351 
1352   bool hasD32 = featureBits[ARM::FeatureD32];
1353 
1354   if (RegNo > 31 || (!hasD32 && RegNo > 15))
1355     return MCDisassembler::Fail;
1356 
1357   unsigned Register = DPRDecoderTable[RegNo];
1358   Inst.addOperand(MCOperand::createReg(Register));
1359   return MCDisassembler::Success;
1360 }
1361 
1362 static DecodeStatus DecodeDPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
1363                                    uint64_t Address, const void *Decoder) {
1364   if (RegNo > 7)
1365     return MCDisassembler::Fail;
1366   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
1367 }
1368 
1369 static DecodeStatus DecodeSPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
1370                                    uint64_t Address, const void *Decoder) {
1371   if (RegNo > 15)
1372     return MCDisassembler::Fail;
1373   return DecodeSPRRegisterClass(Inst, RegNo, Address, Decoder);
1374 }
1375 
1376 static DecodeStatus
1377 DecodeDPR_VFP2RegisterClass(MCInst &Inst, unsigned RegNo,
1378                             uint64_t Address, const void *Decoder) {
1379   if (RegNo > 15)
1380     return MCDisassembler::Fail;
1381   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
1382 }
1383 
1384 static const uint16_t QPRDecoderTable[] = {
1385      ARM::Q0,  ARM::Q1,  ARM::Q2,  ARM::Q3,
1386      ARM::Q4,  ARM::Q5,  ARM::Q6,  ARM::Q7,
1387      ARM::Q8,  ARM::Q9, ARM::Q10, ARM::Q11,
1388     ARM::Q12, ARM::Q13, ARM::Q14, ARM::Q15
1389 };
1390 
1391 static DecodeStatus DecodeQPRRegisterClass(MCInst &Inst, unsigned RegNo,
1392                                    uint64_t Address, const void *Decoder) {
1393   if (RegNo > 31 || (RegNo & 1) != 0)
1394     return MCDisassembler::Fail;
1395   RegNo >>= 1;
1396 
1397   unsigned Register = QPRDecoderTable[RegNo];
1398   Inst.addOperand(MCOperand::createReg(Register));
1399   return MCDisassembler::Success;
1400 }
1401 
1402 static const uint16_t DPairDecoderTable[] = {
1403   ARM::Q0,  ARM::D1_D2,   ARM::Q1,  ARM::D3_D4,   ARM::Q2,  ARM::D5_D6,
1404   ARM::Q3,  ARM::D7_D8,   ARM::Q4,  ARM::D9_D10,  ARM::Q5,  ARM::D11_D12,
1405   ARM::Q6,  ARM::D13_D14, ARM::Q7,  ARM::D15_D16, ARM::Q8,  ARM::D17_D18,
1406   ARM::Q9,  ARM::D19_D20, ARM::Q10, ARM::D21_D22, ARM::Q11, ARM::D23_D24,
1407   ARM::Q12, ARM::D25_D26, ARM::Q13, ARM::D27_D28, ARM::Q14, ARM::D29_D30,
1408   ARM::Q15
1409 };
1410 
1411 static DecodeStatus DecodeDPairRegisterClass(MCInst &Inst, unsigned RegNo,
1412                                    uint64_t Address, const void *Decoder) {
1413   if (RegNo > 30)
1414     return MCDisassembler::Fail;
1415 
1416   unsigned Register = DPairDecoderTable[RegNo];
1417   Inst.addOperand(MCOperand::createReg(Register));
1418   return MCDisassembler::Success;
1419 }
1420 
1421 static const uint16_t DPairSpacedDecoderTable[] = {
1422   ARM::D0_D2,   ARM::D1_D3,   ARM::D2_D4,   ARM::D3_D5,
1423   ARM::D4_D6,   ARM::D5_D7,   ARM::D6_D8,   ARM::D7_D9,
1424   ARM::D8_D10,  ARM::D9_D11,  ARM::D10_D12, ARM::D11_D13,
1425   ARM::D12_D14, ARM::D13_D15, ARM::D14_D16, ARM::D15_D17,
1426   ARM::D16_D18, ARM::D17_D19, ARM::D18_D20, ARM::D19_D21,
1427   ARM::D20_D22, ARM::D21_D23, ARM::D22_D24, ARM::D23_D25,
1428   ARM::D24_D26, ARM::D25_D27, ARM::D26_D28, ARM::D27_D29,
1429   ARM::D28_D30, ARM::D29_D31
1430 };
1431 
1432 static DecodeStatus DecodeDPairSpacedRegisterClass(MCInst &Inst,
1433                                                    unsigned RegNo,
1434                                                    uint64_t Address,
1435                                                    const void *Decoder) {
1436   if (RegNo > 29)
1437     return MCDisassembler::Fail;
1438 
1439   unsigned Register = DPairSpacedDecoderTable[RegNo];
1440   Inst.addOperand(MCOperand::createReg(Register));
1441   return MCDisassembler::Success;
1442 }
1443 
1444 static DecodeStatus DecodePredicateOperand(MCInst &Inst, unsigned Val,
1445                                uint64_t Address, const void *Decoder) {
1446   DecodeStatus S = MCDisassembler::Success;
1447   if (Val == 0xF) return MCDisassembler::Fail;
1448   // AL predicate is not allowed on Thumb1 branches.
1449   if (Inst.getOpcode() == ARM::tBcc && Val == 0xE)
1450     return MCDisassembler::Fail;
1451   if (Val != ARMCC::AL && !ARMInsts[Inst.getOpcode()].isPredicable())
1452     Check(S, MCDisassembler::SoftFail);
1453   Inst.addOperand(MCOperand::createImm(Val));
1454   if (Val == ARMCC::AL) {
1455     Inst.addOperand(MCOperand::createReg(0));
1456   } else
1457     Inst.addOperand(MCOperand::createReg(ARM::CPSR));
1458   return S;
1459 }
1460 
1461 static DecodeStatus DecodeCCOutOperand(MCInst &Inst, unsigned Val,
1462                                uint64_t Address, const void *Decoder) {
1463   if (Val)
1464     Inst.addOperand(MCOperand::createReg(ARM::CPSR));
1465   else
1466     Inst.addOperand(MCOperand::createReg(0));
1467   return MCDisassembler::Success;
1468 }
1469 
1470 static DecodeStatus DecodeSORegImmOperand(MCInst &Inst, unsigned Val,
1471                                uint64_t Address, const void *Decoder) {
1472   DecodeStatus S = MCDisassembler::Success;
1473 
1474   unsigned Rm = fieldFromInstruction(Val, 0, 4);
1475   unsigned type = fieldFromInstruction(Val, 5, 2);
1476   unsigned imm = fieldFromInstruction(Val, 7, 5);
1477 
1478   // Register-immediate
1479   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
1480     return MCDisassembler::Fail;
1481 
1482   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1483   switch (type) {
1484     case 0:
1485       Shift = ARM_AM::lsl;
1486       break;
1487     case 1:
1488       Shift = ARM_AM::lsr;
1489       break;
1490     case 2:
1491       Shift = ARM_AM::asr;
1492       break;
1493     case 3:
1494       Shift = ARM_AM::ror;
1495       break;
1496   }
1497 
1498   if (Shift == ARM_AM::ror && imm == 0)
1499     Shift = ARM_AM::rrx;
1500 
1501   unsigned Op = Shift | (imm << 3);
1502   Inst.addOperand(MCOperand::createImm(Op));
1503 
1504   return S;
1505 }
1506 
1507 static DecodeStatus DecodeSORegRegOperand(MCInst &Inst, unsigned Val,
1508                                uint64_t Address, const void *Decoder) {
1509   DecodeStatus S = MCDisassembler::Success;
1510 
1511   unsigned Rm = fieldFromInstruction(Val, 0, 4);
1512   unsigned type = fieldFromInstruction(Val, 5, 2);
1513   unsigned Rs = fieldFromInstruction(Val, 8, 4);
1514 
1515   // Register-register
1516   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1517     return MCDisassembler::Fail;
1518   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rs, Address, Decoder)))
1519     return MCDisassembler::Fail;
1520 
1521   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1522   switch (type) {
1523     case 0:
1524       Shift = ARM_AM::lsl;
1525       break;
1526     case 1:
1527       Shift = ARM_AM::lsr;
1528       break;
1529     case 2:
1530       Shift = ARM_AM::asr;
1531       break;
1532     case 3:
1533       Shift = ARM_AM::ror;
1534       break;
1535   }
1536 
1537   Inst.addOperand(MCOperand::createImm(Shift));
1538 
1539   return S;
1540 }
1541 
1542 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Val,
1543                                  uint64_t Address, const void *Decoder) {
1544   DecodeStatus S = MCDisassembler::Success;
1545 
1546   bool NeedDisjointWriteback = false;
1547   unsigned WritebackReg = 0;
1548   bool CLRM = false;
1549   switch (Inst.getOpcode()) {
1550   default:
1551     break;
1552   case ARM::LDMIA_UPD:
1553   case ARM::LDMDB_UPD:
1554   case ARM::LDMIB_UPD:
1555   case ARM::LDMDA_UPD:
1556   case ARM::t2LDMIA_UPD:
1557   case ARM::t2LDMDB_UPD:
1558   case ARM::t2STMIA_UPD:
1559   case ARM::t2STMDB_UPD:
1560     NeedDisjointWriteback = true;
1561     WritebackReg = Inst.getOperand(0).getReg();
1562     break;
1563   case ARM::t2CLRM:
1564     CLRM = true;
1565     break;
1566   }
1567 
1568   // Empty register lists are not allowed.
1569   if (Val == 0) return MCDisassembler::Fail;
1570   for (unsigned i = 0; i < 16; ++i) {
1571     if (Val & (1 << i)) {
1572       if (CLRM) {
1573         if (!Check(S, DecodeCLRMGPRRegisterClass(Inst, i, Address, Decoder))) {
1574           return MCDisassembler::Fail;
1575         }
1576       } else {
1577         if (!Check(S, DecodeGPRRegisterClass(Inst, i, Address, Decoder)))
1578           return MCDisassembler::Fail;
1579         // Writeback not allowed if Rn is in the target list.
1580         if (NeedDisjointWriteback && WritebackReg == Inst.end()[-1].getReg())
1581           Check(S, MCDisassembler::SoftFail);
1582       }
1583     }
1584   }
1585 
1586   return S;
1587 }
1588 
1589 static DecodeStatus DecodeSPRRegListOperand(MCInst &Inst, unsigned Val,
1590                                  uint64_t Address, const void *Decoder) {
1591   DecodeStatus S = MCDisassembler::Success;
1592 
1593   unsigned Vd = fieldFromInstruction(Val, 8, 5);
1594   unsigned regs = fieldFromInstruction(Val, 0, 8);
1595 
1596   // In case of unpredictable encoding, tweak the operands.
1597   if (regs == 0 || (Vd + regs) > 32) {
1598     regs = Vd + regs > 32 ? 32 - Vd : regs;
1599     regs = std::max( 1u, regs);
1600     S = MCDisassembler::SoftFail;
1601   }
1602 
1603   if (!Check(S, DecodeSPRRegisterClass(Inst, Vd, Address, Decoder)))
1604     return MCDisassembler::Fail;
1605   for (unsigned i = 0; i < (regs - 1); ++i) {
1606     if (!Check(S, DecodeSPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1607       return MCDisassembler::Fail;
1608   }
1609 
1610   return S;
1611 }
1612 
1613 static DecodeStatus DecodeDPRRegListOperand(MCInst &Inst, unsigned Val,
1614                                  uint64_t Address, const void *Decoder) {
1615   DecodeStatus S = MCDisassembler::Success;
1616 
1617   unsigned Vd = fieldFromInstruction(Val, 8, 5);
1618   unsigned regs = fieldFromInstruction(Val, 1, 7);
1619 
1620   // In case of unpredictable encoding, tweak the operands.
1621   if (regs == 0 || regs > 16 || (Vd + regs) > 32) {
1622     regs = Vd + regs > 32 ? 32 - Vd : regs;
1623     regs = std::max( 1u, regs);
1624     regs = std::min(16u, regs);
1625     S = MCDisassembler::SoftFail;
1626   }
1627 
1628   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
1629       return MCDisassembler::Fail;
1630   for (unsigned i = 0; i < (regs - 1); ++i) {
1631     if (!Check(S, DecodeDPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1632       return MCDisassembler::Fail;
1633   }
1634 
1635   return S;
1636 }
1637 
1638 static DecodeStatus DecodeBitfieldMaskOperand(MCInst &Inst, unsigned Val,
1639                                       uint64_t Address, const void *Decoder) {
1640   // This operand encodes a mask of contiguous zeros between a specified MSB
1641   // and LSB.  To decode it, we create the mask of all bits MSB-and-lower,
1642   // the mask of all bits LSB-and-lower, and then xor them to create
1643   // the mask of that's all ones on [msb, lsb].  Finally we not it to
1644   // create the final mask.
1645   unsigned msb = fieldFromInstruction(Val, 5, 5);
1646   unsigned lsb = fieldFromInstruction(Val, 0, 5);
1647 
1648   DecodeStatus S = MCDisassembler::Success;
1649   if (lsb > msb) {
1650     Check(S, MCDisassembler::SoftFail);
1651     // The check above will cause the warning for the "potentially undefined
1652     // instruction encoding" but we can't build a bad MCOperand value here
1653     // with a lsb > msb or else printing the MCInst will cause a crash.
1654     lsb = msb;
1655   }
1656 
1657   uint32_t msb_mask = 0xFFFFFFFF;
1658   if (msb != 31) msb_mask = (1U << (msb+1)) - 1;
1659   uint32_t lsb_mask = (1U << lsb) - 1;
1660 
1661   Inst.addOperand(MCOperand::createImm(~(msb_mask ^ lsb_mask)));
1662   return S;
1663 }
1664 
1665 static DecodeStatus DecodeCopMemInstruction(MCInst &Inst, unsigned Insn,
1666                                   uint64_t Address, const void *Decoder) {
1667   DecodeStatus S = MCDisassembler::Success;
1668 
1669   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1670   unsigned CRd = fieldFromInstruction(Insn, 12, 4);
1671   unsigned coproc = fieldFromInstruction(Insn, 8, 4);
1672   unsigned imm = fieldFromInstruction(Insn, 0, 8);
1673   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1674   unsigned U = fieldFromInstruction(Insn, 23, 1);
1675   const FeatureBitset &featureBits =
1676     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1677 
1678   switch (Inst.getOpcode()) {
1679     case ARM::LDC_OFFSET:
1680     case ARM::LDC_PRE:
1681     case ARM::LDC_POST:
1682     case ARM::LDC_OPTION:
1683     case ARM::LDCL_OFFSET:
1684     case ARM::LDCL_PRE:
1685     case ARM::LDCL_POST:
1686     case ARM::LDCL_OPTION:
1687     case ARM::STC_OFFSET:
1688     case ARM::STC_PRE:
1689     case ARM::STC_POST:
1690     case ARM::STC_OPTION:
1691     case ARM::STCL_OFFSET:
1692     case ARM::STCL_PRE:
1693     case ARM::STCL_POST:
1694     case ARM::STCL_OPTION:
1695     case ARM::t2LDC_OFFSET:
1696     case ARM::t2LDC_PRE:
1697     case ARM::t2LDC_POST:
1698     case ARM::t2LDC_OPTION:
1699     case ARM::t2LDCL_OFFSET:
1700     case ARM::t2LDCL_PRE:
1701     case ARM::t2LDCL_POST:
1702     case ARM::t2LDCL_OPTION:
1703     case ARM::t2STC_OFFSET:
1704     case ARM::t2STC_PRE:
1705     case ARM::t2STC_POST:
1706     case ARM::t2STC_OPTION:
1707     case ARM::t2STCL_OFFSET:
1708     case ARM::t2STCL_PRE:
1709     case ARM::t2STCL_POST:
1710     case ARM::t2STCL_OPTION:
1711     case ARM::t2LDC2_OFFSET:
1712     case ARM::t2LDC2L_OFFSET:
1713     case ARM::t2LDC2_PRE:
1714     case ARM::t2LDC2L_PRE:
1715     case ARM::t2STC2_OFFSET:
1716     case ARM::t2STC2L_OFFSET:
1717     case ARM::t2STC2_PRE:
1718     case ARM::t2STC2L_PRE:
1719     case ARM::LDC2_OFFSET:
1720     case ARM::LDC2L_OFFSET:
1721     case ARM::LDC2_PRE:
1722     case ARM::LDC2L_PRE:
1723     case ARM::STC2_OFFSET:
1724     case ARM::STC2L_OFFSET:
1725     case ARM::STC2_PRE:
1726     case ARM::STC2L_PRE:
1727     case ARM::t2LDC2_OPTION:
1728     case ARM::t2STC2_OPTION:
1729     case ARM::t2LDC2_POST:
1730     case ARM::t2LDC2L_POST:
1731     case ARM::t2STC2_POST:
1732     case ARM::t2STC2L_POST:
1733     case ARM::LDC2_POST:
1734     case ARM::LDC2L_POST:
1735     case ARM::STC2_POST:
1736     case ARM::STC2L_POST:
1737       if (coproc == 0xA || coproc == 0xB ||
1738           (featureBits[ARM::HasV8_1MMainlineOps] &&
1739            (coproc == 0x8 || coproc == 0x9 || coproc == 0xA || coproc == 0xB ||
1740             coproc == 0xE || coproc == 0xF)))
1741         return MCDisassembler::Fail;
1742       break;
1743     default:
1744       break;
1745   }
1746 
1747   if (featureBits[ARM::HasV8Ops] && (coproc != 14))
1748     return MCDisassembler::Fail;
1749 
1750   Inst.addOperand(MCOperand::createImm(coproc));
1751   Inst.addOperand(MCOperand::createImm(CRd));
1752   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1753     return MCDisassembler::Fail;
1754 
1755   switch (Inst.getOpcode()) {
1756     case ARM::t2LDC2_OFFSET:
1757     case ARM::t2LDC2L_OFFSET:
1758     case ARM::t2LDC2_PRE:
1759     case ARM::t2LDC2L_PRE:
1760     case ARM::t2STC2_OFFSET:
1761     case ARM::t2STC2L_OFFSET:
1762     case ARM::t2STC2_PRE:
1763     case ARM::t2STC2L_PRE:
1764     case ARM::LDC2_OFFSET:
1765     case ARM::LDC2L_OFFSET:
1766     case ARM::LDC2_PRE:
1767     case ARM::LDC2L_PRE:
1768     case ARM::STC2_OFFSET:
1769     case ARM::STC2L_OFFSET:
1770     case ARM::STC2_PRE:
1771     case ARM::STC2L_PRE:
1772     case ARM::t2LDC_OFFSET:
1773     case ARM::t2LDCL_OFFSET:
1774     case ARM::t2LDC_PRE:
1775     case ARM::t2LDCL_PRE:
1776     case ARM::t2STC_OFFSET:
1777     case ARM::t2STCL_OFFSET:
1778     case ARM::t2STC_PRE:
1779     case ARM::t2STCL_PRE:
1780     case ARM::LDC_OFFSET:
1781     case ARM::LDCL_OFFSET:
1782     case ARM::LDC_PRE:
1783     case ARM::LDCL_PRE:
1784     case ARM::STC_OFFSET:
1785     case ARM::STCL_OFFSET:
1786     case ARM::STC_PRE:
1787     case ARM::STCL_PRE:
1788       imm = ARM_AM::getAM5Opc(U ? ARM_AM::add : ARM_AM::sub, imm);
1789       Inst.addOperand(MCOperand::createImm(imm));
1790       break;
1791     case ARM::t2LDC2_POST:
1792     case ARM::t2LDC2L_POST:
1793     case ARM::t2STC2_POST:
1794     case ARM::t2STC2L_POST:
1795     case ARM::LDC2_POST:
1796     case ARM::LDC2L_POST:
1797     case ARM::STC2_POST:
1798     case ARM::STC2L_POST:
1799     case ARM::t2LDC_POST:
1800     case ARM::t2LDCL_POST:
1801     case ARM::t2STC_POST:
1802     case ARM::t2STCL_POST:
1803     case ARM::LDC_POST:
1804     case ARM::LDCL_POST:
1805     case ARM::STC_POST:
1806     case ARM::STCL_POST:
1807       imm |= U << 8;
1808       LLVM_FALLTHROUGH;
1809     default:
1810       // The 'option' variant doesn't encode 'U' in the immediate since
1811       // the immediate is unsigned [0,255].
1812       Inst.addOperand(MCOperand::createImm(imm));
1813       break;
1814   }
1815 
1816   switch (Inst.getOpcode()) {
1817     case ARM::LDC_OFFSET:
1818     case ARM::LDC_PRE:
1819     case ARM::LDC_POST:
1820     case ARM::LDC_OPTION:
1821     case ARM::LDCL_OFFSET:
1822     case ARM::LDCL_PRE:
1823     case ARM::LDCL_POST:
1824     case ARM::LDCL_OPTION:
1825     case ARM::STC_OFFSET:
1826     case ARM::STC_PRE:
1827     case ARM::STC_POST:
1828     case ARM::STC_OPTION:
1829     case ARM::STCL_OFFSET:
1830     case ARM::STCL_PRE:
1831     case ARM::STCL_POST:
1832     case ARM::STCL_OPTION:
1833       if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1834         return MCDisassembler::Fail;
1835       break;
1836     default:
1837       break;
1838   }
1839 
1840   return S;
1841 }
1842 
1843 static DecodeStatus
1844 DecodeAddrMode2IdxInstruction(MCInst &Inst, unsigned Insn,
1845                               uint64_t Address, const void *Decoder) {
1846   DecodeStatus S = MCDisassembler::Success;
1847 
1848   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1849   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
1850   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
1851   unsigned imm = fieldFromInstruction(Insn, 0, 12);
1852   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1853   unsigned reg = fieldFromInstruction(Insn, 25, 1);
1854   unsigned P = fieldFromInstruction(Insn, 24, 1);
1855   unsigned W = fieldFromInstruction(Insn, 21, 1);
1856 
1857   // On stores, the writeback operand precedes Rt.
1858   switch (Inst.getOpcode()) {
1859     case ARM::STR_POST_IMM:
1860     case ARM::STR_POST_REG:
1861     case ARM::STRB_POST_IMM:
1862     case ARM::STRB_POST_REG:
1863     case ARM::STRT_POST_REG:
1864     case ARM::STRT_POST_IMM:
1865     case ARM::STRBT_POST_REG:
1866     case ARM::STRBT_POST_IMM:
1867       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1868         return MCDisassembler::Fail;
1869       break;
1870     default:
1871       break;
1872   }
1873 
1874   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
1875     return MCDisassembler::Fail;
1876 
1877   // On loads, the writeback operand comes after Rt.
1878   switch (Inst.getOpcode()) {
1879     case ARM::LDR_POST_IMM:
1880     case ARM::LDR_POST_REG:
1881     case ARM::LDRB_POST_IMM:
1882     case ARM::LDRB_POST_REG:
1883     case ARM::LDRBT_POST_REG:
1884     case ARM::LDRBT_POST_IMM:
1885     case ARM::LDRT_POST_REG:
1886     case ARM::LDRT_POST_IMM:
1887       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1888         return MCDisassembler::Fail;
1889       break;
1890     default:
1891       break;
1892   }
1893 
1894   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1895     return MCDisassembler::Fail;
1896 
1897   ARM_AM::AddrOpc Op = ARM_AM::add;
1898   if (!fieldFromInstruction(Insn, 23, 1))
1899     Op = ARM_AM::sub;
1900 
1901   bool writeback = (P == 0) || (W == 1);
1902   unsigned idx_mode = 0;
1903   if (P && writeback)
1904     idx_mode = ARMII::IndexModePre;
1905   else if (!P && writeback)
1906     idx_mode = ARMII::IndexModePost;
1907 
1908   if (writeback && (Rn == 15 || Rn == Rt))
1909     S = MCDisassembler::SoftFail; // UNPREDICTABLE
1910 
1911   if (reg) {
1912     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1913       return MCDisassembler::Fail;
1914     ARM_AM::ShiftOpc Opc = ARM_AM::lsl;
1915     switch( fieldFromInstruction(Insn, 5, 2)) {
1916       case 0:
1917         Opc = ARM_AM::lsl;
1918         break;
1919       case 1:
1920         Opc = ARM_AM::lsr;
1921         break;
1922       case 2:
1923         Opc = ARM_AM::asr;
1924         break;
1925       case 3:
1926         Opc = ARM_AM::ror;
1927         break;
1928       default:
1929         return MCDisassembler::Fail;
1930     }
1931     unsigned amt = fieldFromInstruction(Insn, 7, 5);
1932     if (Opc == ARM_AM::ror && amt == 0)
1933       Opc = ARM_AM::rrx;
1934     unsigned imm = ARM_AM::getAM2Opc(Op, amt, Opc, idx_mode);
1935 
1936     Inst.addOperand(MCOperand::createImm(imm));
1937   } else {
1938     Inst.addOperand(MCOperand::createReg(0));
1939     unsigned tmp = ARM_AM::getAM2Opc(Op, imm, ARM_AM::lsl, idx_mode);
1940     Inst.addOperand(MCOperand::createImm(tmp));
1941   }
1942 
1943   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1944     return MCDisassembler::Fail;
1945 
1946   return S;
1947 }
1948 
1949 static DecodeStatus DecodeSORegMemOperand(MCInst &Inst, unsigned Val,
1950                                   uint64_t Address, const void *Decoder) {
1951   DecodeStatus S = MCDisassembler::Success;
1952 
1953   unsigned Rn = fieldFromInstruction(Val, 13, 4);
1954   unsigned Rm = fieldFromInstruction(Val,  0, 4);
1955   unsigned type = fieldFromInstruction(Val, 5, 2);
1956   unsigned imm = fieldFromInstruction(Val, 7, 5);
1957   unsigned U = fieldFromInstruction(Val, 12, 1);
1958 
1959   ARM_AM::ShiftOpc ShOp = ARM_AM::lsl;
1960   switch (type) {
1961     case 0:
1962       ShOp = ARM_AM::lsl;
1963       break;
1964     case 1:
1965       ShOp = ARM_AM::lsr;
1966       break;
1967     case 2:
1968       ShOp = ARM_AM::asr;
1969       break;
1970     case 3:
1971       ShOp = ARM_AM::ror;
1972       break;
1973   }
1974 
1975   if (ShOp == ARM_AM::ror && imm == 0)
1976     ShOp = ARM_AM::rrx;
1977 
1978   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1979     return MCDisassembler::Fail;
1980   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1981     return MCDisassembler::Fail;
1982   unsigned shift;
1983   if (U)
1984     shift = ARM_AM::getAM2Opc(ARM_AM::add, imm, ShOp);
1985   else
1986     shift = ARM_AM::getAM2Opc(ARM_AM::sub, imm, ShOp);
1987   Inst.addOperand(MCOperand::createImm(shift));
1988 
1989   return S;
1990 }
1991 
1992 static DecodeStatus
1993 DecodeAddrMode3Instruction(MCInst &Inst, unsigned Insn,
1994                            uint64_t Address, const void *Decoder) {
1995   DecodeStatus S = MCDisassembler::Success;
1996 
1997   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
1998   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1999   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2000   unsigned type = fieldFromInstruction(Insn, 22, 1);
2001   unsigned imm = fieldFromInstruction(Insn, 8, 4);
2002   unsigned U = ((~fieldFromInstruction(Insn, 23, 1)) & 1) << 8;
2003   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2004   unsigned W = fieldFromInstruction(Insn, 21, 1);
2005   unsigned P = fieldFromInstruction(Insn, 24, 1);
2006   unsigned Rt2 = Rt + 1;
2007 
2008   bool writeback = (W == 1) | (P == 0);
2009 
2010   // For {LD,ST}RD, Rt must be even, else undefined.
2011   switch (Inst.getOpcode()) {
2012     case ARM::STRD:
2013     case ARM::STRD_PRE:
2014     case ARM::STRD_POST:
2015     case ARM::LDRD:
2016     case ARM::LDRD_PRE:
2017     case ARM::LDRD_POST:
2018       if (Rt & 0x1) S = MCDisassembler::SoftFail;
2019       break;
2020     default:
2021       break;
2022   }
2023   switch (Inst.getOpcode()) {
2024     case ARM::STRD:
2025     case ARM::STRD_PRE:
2026     case ARM::STRD_POST:
2027       if (P == 0 && W == 1)
2028         S = MCDisassembler::SoftFail;
2029 
2030       if (writeback && (Rn == 15 || Rn == Rt || Rn == Rt2))
2031         S = MCDisassembler::SoftFail;
2032       if (type && Rm == 15)
2033         S = MCDisassembler::SoftFail;
2034       if (Rt2 == 15)
2035         S = MCDisassembler::SoftFail;
2036       if (!type && fieldFromInstruction(Insn, 8, 4))
2037         S = MCDisassembler::SoftFail;
2038       break;
2039     case ARM::STRH:
2040     case ARM::STRH_PRE:
2041     case ARM::STRH_POST:
2042       if (Rt == 15)
2043         S = MCDisassembler::SoftFail;
2044       if (writeback && (Rn == 15 || Rn == Rt))
2045         S = MCDisassembler::SoftFail;
2046       if (!type && Rm == 15)
2047         S = MCDisassembler::SoftFail;
2048       break;
2049     case ARM::LDRD:
2050     case ARM::LDRD_PRE:
2051     case ARM::LDRD_POST:
2052       if (type && Rn == 15) {
2053         if (Rt2 == 15)
2054           S = MCDisassembler::SoftFail;
2055         break;
2056       }
2057       if (P == 0 && W == 1)
2058         S = MCDisassembler::SoftFail;
2059       if (!type && (Rt2 == 15 || Rm == 15 || Rm == Rt || Rm == Rt2))
2060         S = MCDisassembler::SoftFail;
2061       if (!type && writeback && Rn == 15)
2062         S = MCDisassembler::SoftFail;
2063       if (writeback && (Rn == Rt || Rn == Rt2))
2064         S = MCDisassembler::SoftFail;
2065       break;
2066     case ARM::LDRH:
2067     case ARM::LDRH_PRE:
2068     case ARM::LDRH_POST:
2069       if (type && Rn == 15) {
2070         if (Rt == 15)
2071           S = MCDisassembler::SoftFail;
2072         break;
2073       }
2074       if (Rt == 15)
2075         S = MCDisassembler::SoftFail;
2076       if (!type && Rm == 15)
2077         S = MCDisassembler::SoftFail;
2078       if (!type && writeback && (Rn == 15 || Rn == Rt))
2079         S = MCDisassembler::SoftFail;
2080       break;
2081     case ARM::LDRSH:
2082     case ARM::LDRSH_PRE:
2083     case ARM::LDRSH_POST:
2084     case ARM::LDRSB:
2085     case ARM::LDRSB_PRE:
2086     case ARM::LDRSB_POST:
2087       if (type && Rn == 15) {
2088         if (Rt == 15)
2089           S = MCDisassembler::SoftFail;
2090         break;
2091       }
2092       if (type && (Rt == 15 || (writeback && Rn == Rt)))
2093         S = MCDisassembler::SoftFail;
2094       if (!type && (Rt == 15 || Rm == 15))
2095         S = MCDisassembler::SoftFail;
2096       if (!type && writeback && (Rn == 15 || Rn == Rt))
2097         S = MCDisassembler::SoftFail;
2098       break;
2099     default:
2100       break;
2101   }
2102 
2103   if (writeback) { // Writeback
2104     if (P)
2105       U |= ARMII::IndexModePre << 9;
2106     else
2107       U |= ARMII::IndexModePost << 9;
2108 
2109     // On stores, the writeback operand precedes Rt.
2110     switch (Inst.getOpcode()) {
2111     case ARM::STRD:
2112     case ARM::STRD_PRE:
2113     case ARM::STRD_POST:
2114     case ARM::STRH:
2115     case ARM::STRH_PRE:
2116     case ARM::STRH_POST:
2117       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2118         return MCDisassembler::Fail;
2119       break;
2120     default:
2121       break;
2122     }
2123   }
2124 
2125   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
2126     return MCDisassembler::Fail;
2127   switch (Inst.getOpcode()) {
2128     case ARM::STRD:
2129     case ARM::STRD_PRE:
2130     case ARM::STRD_POST:
2131     case ARM::LDRD:
2132     case ARM::LDRD_PRE:
2133     case ARM::LDRD_POST:
2134       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder)))
2135         return MCDisassembler::Fail;
2136       break;
2137     default:
2138       break;
2139   }
2140 
2141   if (writeback) {
2142     // On loads, the writeback operand comes after Rt.
2143     switch (Inst.getOpcode()) {
2144     case ARM::LDRD:
2145     case ARM::LDRD_PRE:
2146     case ARM::LDRD_POST:
2147     case ARM::LDRH:
2148     case ARM::LDRH_PRE:
2149     case ARM::LDRH_POST:
2150     case ARM::LDRSH:
2151     case ARM::LDRSH_PRE:
2152     case ARM::LDRSH_POST:
2153     case ARM::LDRSB:
2154     case ARM::LDRSB_PRE:
2155     case ARM::LDRSB_POST:
2156     case ARM::LDRHTr:
2157     case ARM::LDRSBTr:
2158       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2159         return MCDisassembler::Fail;
2160       break;
2161     default:
2162       break;
2163     }
2164   }
2165 
2166   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2167     return MCDisassembler::Fail;
2168 
2169   if (type) {
2170     Inst.addOperand(MCOperand::createReg(0));
2171     Inst.addOperand(MCOperand::createImm(U | (imm << 4) | Rm));
2172   } else {
2173     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2174     return MCDisassembler::Fail;
2175     Inst.addOperand(MCOperand::createImm(U));
2176   }
2177 
2178   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2179     return MCDisassembler::Fail;
2180 
2181   return S;
2182 }
2183 
2184 static DecodeStatus DecodeRFEInstruction(MCInst &Inst, unsigned Insn,
2185                                  uint64_t Address, const void *Decoder) {
2186   DecodeStatus S = MCDisassembler::Success;
2187 
2188   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2189   unsigned mode = fieldFromInstruction(Insn, 23, 2);
2190 
2191   switch (mode) {
2192     case 0:
2193       mode = ARM_AM::da;
2194       break;
2195     case 1:
2196       mode = ARM_AM::ia;
2197       break;
2198     case 2:
2199       mode = ARM_AM::db;
2200       break;
2201     case 3:
2202       mode = ARM_AM::ib;
2203       break;
2204   }
2205 
2206   Inst.addOperand(MCOperand::createImm(mode));
2207   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2208     return MCDisassembler::Fail;
2209 
2210   return S;
2211 }
2212 
2213 static DecodeStatus DecodeQADDInstruction(MCInst &Inst, unsigned Insn,
2214                                uint64_t Address, const void *Decoder) {
2215   DecodeStatus S = MCDisassembler::Success;
2216 
2217   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2218   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2219   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2220   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2221 
2222   if (pred == 0xF)
2223     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
2224 
2225   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2226     return MCDisassembler::Fail;
2227   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
2228     return MCDisassembler::Fail;
2229   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
2230     return MCDisassembler::Fail;
2231   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2232     return MCDisassembler::Fail;
2233   return S;
2234 }
2235 
2236 static DecodeStatus DecodeMemMultipleWritebackInstruction(MCInst &Inst,
2237                                   unsigned Insn,
2238                                   uint64_t Address, const void *Decoder) {
2239   DecodeStatus S = MCDisassembler::Success;
2240 
2241   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2242   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2243   unsigned reglist = fieldFromInstruction(Insn, 0, 16);
2244 
2245   if (pred == 0xF) {
2246     // Ambiguous with RFE and SRS
2247     switch (Inst.getOpcode()) {
2248       case ARM::LDMDA:
2249         Inst.setOpcode(ARM::RFEDA);
2250         break;
2251       case ARM::LDMDA_UPD:
2252         Inst.setOpcode(ARM::RFEDA_UPD);
2253         break;
2254       case ARM::LDMDB:
2255         Inst.setOpcode(ARM::RFEDB);
2256         break;
2257       case ARM::LDMDB_UPD:
2258         Inst.setOpcode(ARM::RFEDB_UPD);
2259         break;
2260       case ARM::LDMIA:
2261         Inst.setOpcode(ARM::RFEIA);
2262         break;
2263       case ARM::LDMIA_UPD:
2264         Inst.setOpcode(ARM::RFEIA_UPD);
2265         break;
2266       case ARM::LDMIB:
2267         Inst.setOpcode(ARM::RFEIB);
2268         break;
2269       case ARM::LDMIB_UPD:
2270         Inst.setOpcode(ARM::RFEIB_UPD);
2271         break;
2272       case ARM::STMDA:
2273         Inst.setOpcode(ARM::SRSDA);
2274         break;
2275       case ARM::STMDA_UPD:
2276         Inst.setOpcode(ARM::SRSDA_UPD);
2277         break;
2278       case ARM::STMDB:
2279         Inst.setOpcode(ARM::SRSDB);
2280         break;
2281       case ARM::STMDB_UPD:
2282         Inst.setOpcode(ARM::SRSDB_UPD);
2283         break;
2284       case ARM::STMIA:
2285         Inst.setOpcode(ARM::SRSIA);
2286         break;
2287       case ARM::STMIA_UPD:
2288         Inst.setOpcode(ARM::SRSIA_UPD);
2289         break;
2290       case ARM::STMIB:
2291         Inst.setOpcode(ARM::SRSIB);
2292         break;
2293       case ARM::STMIB_UPD:
2294         Inst.setOpcode(ARM::SRSIB_UPD);
2295         break;
2296       default:
2297         return MCDisassembler::Fail;
2298     }
2299 
2300     // For stores (which become SRS's, the only operand is the mode.
2301     if (fieldFromInstruction(Insn, 20, 1) == 0) {
2302       // Check SRS encoding constraints
2303       if (!(fieldFromInstruction(Insn, 22, 1) == 1 &&
2304             fieldFromInstruction(Insn, 20, 1) == 0))
2305         return MCDisassembler::Fail;
2306 
2307       Inst.addOperand(
2308           MCOperand::createImm(fieldFromInstruction(Insn, 0, 4)));
2309       return S;
2310     }
2311 
2312     return DecodeRFEInstruction(Inst, Insn, Address, Decoder);
2313   }
2314 
2315   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2316     return MCDisassembler::Fail;
2317   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2318     return MCDisassembler::Fail; // Tied
2319   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2320     return MCDisassembler::Fail;
2321   if (!Check(S, DecodeRegListOperand(Inst, reglist, Address, Decoder)))
2322     return MCDisassembler::Fail;
2323 
2324   return S;
2325 }
2326 
2327 // Check for UNPREDICTABLE predicated ESB instruction
2328 static DecodeStatus DecodeHINTInstruction(MCInst &Inst, unsigned Insn,
2329                                  uint64_t Address, const void *Decoder) {
2330   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2331   unsigned imm8 = fieldFromInstruction(Insn, 0, 8);
2332   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
2333   const FeatureBitset &FeatureBits = Dis->getSubtargetInfo().getFeatureBits();
2334 
2335   DecodeStatus S = MCDisassembler::Success;
2336 
2337   Inst.addOperand(MCOperand::createImm(imm8));
2338 
2339   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2340     return MCDisassembler::Fail;
2341 
2342   // ESB is unpredictable if pred != AL. Without the RAS extension, it is a NOP,
2343   // so all predicates should be allowed.
2344   if (imm8 == 0x10 && pred != 0xe && ((FeatureBits[ARM::FeatureRAS]) != 0))
2345     S = MCDisassembler::SoftFail;
2346 
2347   return S;
2348 }
2349 
2350 static DecodeStatus DecodeCPSInstruction(MCInst &Inst, unsigned Insn,
2351                                  uint64_t Address, const void *Decoder) {
2352   unsigned imod = fieldFromInstruction(Insn, 18, 2);
2353   unsigned M = fieldFromInstruction(Insn, 17, 1);
2354   unsigned iflags = fieldFromInstruction(Insn, 6, 3);
2355   unsigned mode = fieldFromInstruction(Insn, 0, 5);
2356 
2357   DecodeStatus S = MCDisassembler::Success;
2358 
2359   // This decoder is called from multiple location that do not check
2360   // the full encoding is valid before they do.
2361   if (fieldFromInstruction(Insn, 5, 1) != 0 ||
2362       fieldFromInstruction(Insn, 16, 1) != 0 ||
2363       fieldFromInstruction(Insn, 20, 8) != 0x10)
2364     return MCDisassembler::Fail;
2365 
2366   // imod == '01' --> UNPREDICTABLE
2367   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
2368   // return failure here.  The '01' imod value is unprintable, so there's
2369   // nothing useful we could do even if we returned UNPREDICTABLE.
2370 
2371   if (imod == 1) return MCDisassembler::Fail;
2372 
2373   if (imod && M) {
2374     Inst.setOpcode(ARM::CPS3p);
2375     Inst.addOperand(MCOperand::createImm(imod));
2376     Inst.addOperand(MCOperand::createImm(iflags));
2377     Inst.addOperand(MCOperand::createImm(mode));
2378   } else if (imod && !M) {
2379     Inst.setOpcode(ARM::CPS2p);
2380     Inst.addOperand(MCOperand::createImm(imod));
2381     Inst.addOperand(MCOperand::createImm(iflags));
2382     if (mode) S = MCDisassembler::SoftFail;
2383   } else if (!imod && M) {
2384     Inst.setOpcode(ARM::CPS1p);
2385     Inst.addOperand(MCOperand::createImm(mode));
2386     if (iflags) S = MCDisassembler::SoftFail;
2387   } else {
2388     // imod == '00' && M == '0' --> UNPREDICTABLE
2389     Inst.setOpcode(ARM::CPS1p);
2390     Inst.addOperand(MCOperand::createImm(mode));
2391     S = MCDisassembler::SoftFail;
2392   }
2393 
2394   return S;
2395 }
2396 
2397 static DecodeStatus DecodeT2CPSInstruction(MCInst &Inst, unsigned Insn,
2398                                  uint64_t Address, const void *Decoder) {
2399   unsigned imod = fieldFromInstruction(Insn, 9, 2);
2400   unsigned M = fieldFromInstruction(Insn, 8, 1);
2401   unsigned iflags = fieldFromInstruction(Insn, 5, 3);
2402   unsigned mode = fieldFromInstruction(Insn, 0, 5);
2403 
2404   DecodeStatus S = MCDisassembler::Success;
2405 
2406   // imod == '01' --> UNPREDICTABLE
2407   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
2408   // return failure here.  The '01' imod value is unprintable, so there's
2409   // nothing useful we could do even if we returned UNPREDICTABLE.
2410 
2411   if (imod == 1) return MCDisassembler::Fail;
2412 
2413   if (imod && M) {
2414     Inst.setOpcode(ARM::t2CPS3p);
2415     Inst.addOperand(MCOperand::createImm(imod));
2416     Inst.addOperand(MCOperand::createImm(iflags));
2417     Inst.addOperand(MCOperand::createImm(mode));
2418   } else if (imod && !M) {
2419     Inst.setOpcode(ARM::t2CPS2p);
2420     Inst.addOperand(MCOperand::createImm(imod));
2421     Inst.addOperand(MCOperand::createImm(iflags));
2422     if (mode) S = MCDisassembler::SoftFail;
2423   } else if (!imod && M) {
2424     Inst.setOpcode(ARM::t2CPS1p);
2425     Inst.addOperand(MCOperand::createImm(mode));
2426     if (iflags) S = MCDisassembler::SoftFail;
2427   } else {
2428     // imod == '00' && M == '0' --> this is a HINT instruction
2429     int imm = fieldFromInstruction(Insn, 0, 8);
2430     // HINT are defined only for immediate in [0..4]
2431     if(imm > 4) return MCDisassembler::Fail;
2432     Inst.setOpcode(ARM::t2HINT);
2433     Inst.addOperand(MCOperand::createImm(imm));
2434   }
2435 
2436   return S;
2437 }
2438 
2439 static DecodeStatus DecodeT2MOVTWInstruction(MCInst &Inst, unsigned Insn,
2440                                  uint64_t Address, const void *Decoder) {
2441   DecodeStatus S = MCDisassembler::Success;
2442 
2443   unsigned Rd = fieldFromInstruction(Insn, 8, 4);
2444   unsigned imm = 0;
2445 
2446   imm |= (fieldFromInstruction(Insn, 0, 8) << 0);
2447   imm |= (fieldFromInstruction(Insn, 12, 3) << 8);
2448   imm |= (fieldFromInstruction(Insn, 16, 4) << 12);
2449   imm |= (fieldFromInstruction(Insn, 26, 1) << 11);
2450 
2451   if (Inst.getOpcode() == ARM::t2MOVTi16)
2452     if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
2453       return MCDisassembler::Fail;
2454   if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
2455     return MCDisassembler::Fail;
2456 
2457   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
2458     Inst.addOperand(MCOperand::createImm(imm));
2459 
2460   return S;
2461 }
2462 
2463 static DecodeStatus DecodeArmMOVTWInstruction(MCInst &Inst, unsigned Insn,
2464                                  uint64_t Address, const void *Decoder) {
2465   DecodeStatus S = MCDisassembler::Success;
2466 
2467   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2468   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2469   unsigned imm = 0;
2470 
2471   imm |= (fieldFromInstruction(Insn, 0, 12) << 0);
2472   imm |= (fieldFromInstruction(Insn, 16, 4) << 12);
2473 
2474   if (Inst.getOpcode() == ARM::MOVTi16)
2475     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2476       return MCDisassembler::Fail;
2477 
2478   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2479     return MCDisassembler::Fail;
2480 
2481   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
2482     Inst.addOperand(MCOperand::createImm(imm));
2483 
2484   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2485     return MCDisassembler::Fail;
2486 
2487   return S;
2488 }
2489 
2490 static DecodeStatus DecodeSMLAInstruction(MCInst &Inst, unsigned Insn,
2491                                  uint64_t Address, const void *Decoder) {
2492   DecodeStatus S = MCDisassembler::Success;
2493 
2494   unsigned Rd = fieldFromInstruction(Insn, 16, 4);
2495   unsigned Rn = fieldFromInstruction(Insn, 0, 4);
2496   unsigned Rm = fieldFromInstruction(Insn, 8, 4);
2497   unsigned Ra = fieldFromInstruction(Insn, 12, 4);
2498   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2499 
2500   if (pred == 0xF)
2501     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
2502 
2503   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2504     return MCDisassembler::Fail;
2505   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
2506     return MCDisassembler::Fail;
2507   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
2508     return MCDisassembler::Fail;
2509   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Ra, Address, Decoder)))
2510     return MCDisassembler::Fail;
2511 
2512   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2513     return MCDisassembler::Fail;
2514 
2515   return S;
2516 }
2517 
2518 static DecodeStatus DecodeTSTInstruction(MCInst &Inst, unsigned Insn,
2519                                   uint64_t Address, const void *Decoder) {
2520   DecodeStatus S = MCDisassembler::Success;
2521 
2522   unsigned Pred = fieldFromInstruction(Insn, 28, 4);
2523   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2524   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2525 
2526   if (Pred == 0xF)
2527     return DecodeSETPANInstruction(Inst, Insn, Address, Decoder);
2528 
2529   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2530     return MCDisassembler::Fail;
2531   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2532     return MCDisassembler::Fail;
2533   if (!Check(S, DecodePredicateOperand(Inst, Pred, Address, Decoder)))
2534     return MCDisassembler::Fail;
2535 
2536   return S;
2537 }
2538 
2539 static DecodeStatus DecodeSETPANInstruction(MCInst &Inst, unsigned Insn,
2540                                   uint64_t Address, const void *Decoder) {
2541   DecodeStatus S = MCDisassembler::Success;
2542 
2543   unsigned Imm = fieldFromInstruction(Insn, 9, 1);
2544 
2545   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
2546   const FeatureBitset &FeatureBits = Dis->getSubtargetInfo().getFeatureBits();
2547 
2548   if (!FeatureBits[ARM::HasV8_1aOps] ||
2549       !FeatureBits[ARM::HasV8Ops])
2550     return MCDisassembler::Fail;
2551 
2552   // Decoder can be called from DecodeTST, which does not check the full
2553   // encoding is valid.
2554   if (fieldFromInstruction(Insn, 20,12) != 0xf11 ||
2555       fieldFromInstruction(Insn, 4,4) != 0)
2556     return MCDisassembler::Fail;
2557   if (fieldFromInstruction(Insn, 10,10) != 0 ||
2558       fieldFromInstruction(Insn, 0,4) != 0)
2559     S = MCDisassembler::SoftFail;
2560 
2561   Inst.setOpcode(ARM::SETPAN);
2562   Inst.addOperand(MCOperand::createImm(Imm));
2563 
2564   return S;
2565 }
2566 
2567 static DecodeStatus DecodeAddrModeImm12Operand(MCInst &Inst, unsigned Val,
2568                            uint64_t Address, const void *Decoder) {
2569   DecodeStatus S = MCDisassembler::Success;
2570 
2571   unsigned add = fieldFromInstruction(Val, 12, 1);
2572   unsigned imm = fieldFromInstruction(Val, 0, 12);
2573   unsigned Rn = fieldFromInstruction(Val, 13, 4);
2574 
2575   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2576     return MCDisassembler::Fail;
2577 
2578   if (!add) imm *= -1;
2579   if (imm == 0 && !add) imm = INT32_MIN;
2580   Inst.addOperand(MCOperand::createImm(imm));
2581   if (Rn == 15)
2582     tryAddingPcLoadReferenceComment(Address, Address + imm + 8, Decoder);
2583 
2584   return S;
2585 }
2586 
2587 static DecodeStatus DecodeAddrMode5Operand(MCInst &Inst, unsigned Val,
2588                                    uint64_t Address, const void *Decoder) {
2589   DecodeStatus S = MCDisassembler::Success;
2590 
2591   unsigned Rn = fieldFromInstruction(Val, 9, 4);
2592   // U == 1 to add imm, 0 to subtract it.
2593   unsigned U = fieldFromInstruction(Val, 8, 1);
2594   unsigned imm = fieldFromInstruction(Val, 0, 8);
2595 
2596   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2597     return MCDisassembler::Fail;
2598 
2599   if (U)
2600     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5Opc(ARM_AM::add, imm)));
2601   else
2602     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5Opc(ARM_AM::sub, imm)));
2603 
2604   return S;
2605 }
2606 
2607 static DecodeStatus DecodeAddrMode5FP16Operand(MCInst &Inst, unsigned Val,
2608                                    uint64_t Address, const void *Decoder) {
2609   DecodeStatus S = MCDisassembler::Success;
2610 
2611   unsigned Rn = fieldFromInstruction(Val, 9, 4);
2612   // U == 1 to add imm, 0 to subtract it.
2613   unsigned U = fieldFromInstruction(Val, 8, 1);
2614   unsigned imm = fieldFromInstruction(Val, 0, 8);
2615 
2616   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2617     return MCDisassembler::Fail;
2618 
2619   if (U)
2620     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5FP16Opc(ARM_AM::add, imm)));
2621   else
2622     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5FP16Opc(ARM_AM::sub, imm)));
2623 
2624   return S;
2625 }
2626 
2627 static DecodeStatus DecodeAddrMode7Operand(MCInst &Inst, unsigned Val,
2628                                    uint64_t Address, const void *Decoder) {
2629   return DecodeGPRRegisterClass(Inst, Val, Address, Decoder);
2630 }
2631 
2632 static DecodeStatus
2633 DecodeT2BInstruction(MCInst &Inst, unsigned Insn,
2634                      uint64_t Address, const void *Decoder) {
2635   DecodeStatus Status = MCDisassembler::Success;
2636 
2637   // Note the J1 and J2 values are from the encoded instruction.  So here
2638   // change them to I1 and I2 values via as documented:
2639   // I1 = NOT(J1 EOR S);
2640   // I2 = NOT(J2 EOR S);
2641   // and build the imm32 with one trailing zero as documented:
2642   // imm32 = SignExtend(S:I1:I2:imm10:imm11:'0', 32);
2643   unsigned S = fieldFromInstruction(Insn, 26, 1);
2644   unsigned J1 = fieldFromInstruction(Insn, 13, 1);
2645   unsigned J2 = fieldFromInstruction(Insn, 11, 1);
2646   unsigned I1 = !(J1 ^ S);
2647   unsigned I2 = !(J2 ^ S);
2648   unsigned imm10 = fieldFromInstruction(Insn, 16, 10);
2649   unsigned imm11 = fieldFromInstruction(Insn, 0, 11);
2650   unsigned tmp = (S << 23) | (I1 << 22) | (I2 << 21) | (imm10 << 11) | imm11;
2651   int imm32 = SignExtend32<25>(tmp << 1);
2652   if (!tryAddingSymbolicOperand(Address, Address + imm32 + 4,
2653                                 true, 4, Inst, Decoder))
2654     Inst.addOperand(MCOperand::createImm(imm32));
2655 
2656   return Status;
2657 }
2658 
2659 static DecodeStatus
2660 DecodeBranchImmInstruction(MCInst &Inst, unsigned Insn,
2661                            uint64_t Address, const void *Decoder) {
2662   DecodeStatus S = MCDisassembler::Success;
2663 
2664   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2665   unsigned imm = fieldFromInstruction(Insn, 0, 24) << 2;
2666 
2667   if (pred == 0xF) {
2668     Inst.setOpcode(ARM::BLXi);
2669     imm |= fieldFromInstruction(Insn, 24, 1) << 1;
2670     if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<26>(imm) + 8,
2671                                   true, 4, Inst, Decoder))
2672     Inst.addOperand(MCOperand::createImm(SignExtend32<26>(imm)));
2673     return S;
2674   }
2675 
2676   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<26>(imm) + 8,
2677                                 true, 4, Inst, Decoder))
2678     Inst.addOperand(MCOperand::createImm(SignExtend32<26>(imm)));
2679 
2680   // We already have BL_pred for BL w/ predicate, no need to add addition
2681   // predicate opreands for BL
2682   if (Inst.getOpcode() != ARM::BL)
2683     if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2684       return MCDisassembler::Fail;
2685 
2686   return S;
2687 }
2688 
2689 static DecodeStatus DecodeAddrMode6Operand(MCInst &Inst, unsigned Val,
2690                                    uint64_t Address, const void *Decoder) {
2691   DecodeStatus S = MCDisassembler::Success;
2692 
2693   unsigned Rm = fieldFromInstruction(Val, 0, 4);
2694   unsigned align = fieldFromInstruction(Val, 4, 2);
2695 
2696   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2697     return MCDisassembler::Fail;
2698   if (!align)
2699     Inst.addOperand(MCOperand::createImm(0));
2700   else
2701     Inst.addOperand(MCOperand::createImm(4 << align));
2702 
2703   return S;
2704 }
2705 
2706 static DecodeStatus DecodeVLDInstruction(MCInst &Inst, unsigned Insn,
2707                                    uint64_t Address, const void *Decoder) {
2708   DecodeStatus S = MCDisassembler::Success;
2709 
2710   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2711   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
2712   unsigned wb = fieldFromInstruction(Insn, 16, 4);
2713   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2714   Rn |= fieldFromInstruction(Insn, 4, 2) << 4;
2715   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2716 
2717   // First output register
2718   switch (Inst.getOpcode()) {
2719   case ARM::VLD1q16: case ARM::VLD1q32: case ARM::VLD1q64: case ARM::VLD1q8:
2720   case ARM::VLD1q16wb_fixed: case ARM::VLD1q16wb_register:
2721   case ARM::VLD1q32wb_fixed: case ARM::VLD1q32wb_register:
2722   case ARM::VLD1q64wb_fixed: case ARM::VLD1q64wb_register:
2723   case ARM::VLD1q8wb_fixed: case ARM::VLD1q8wb_register:
2724   case ARM::VLD2d16: case ARM::VLD2d32: case ARM::VLD2d8:
2725   case ARM::VLD2d16wb_fixed: case ARM::VLD2d16wb_register:
2726   case ARM::VLD2d32wb_fixed: case ARM::VLD2d32wb_register:
2727   case ARM::VLD2d8wb_fixed: case ARM::VLD2d8wb_register:
2728     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
2729       return MCDisassembler::Fail;
2730     break;
2731   case ARM::VLD2b16:
2732   case ARM::VLD2b32:
2733   case ARM::VLD2b8:
2734   case ARM::VLD2b16wb_fixed:
2735   case ARM::VLD2b16wb_register:
2736   case ARM::VLD2b32wb_fixed:
2737   case ARM::VLD2b32wb_register:
2738   case ARM::VLD2b8wb_fixed:
2739   case ARM::VLD2b8wb_register:
2740     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
2741       return MCDisassembler::Fail;
2742     break;
2743   default:
2744     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2745       return MCDisassembler::Fail;
2746   }
2747 
2748   // Second output register
2749   switch (Inst.getOpcode()) {
2750     case ARM::VLD3d8:
2751     case ARM::VLD3d16:
2752     case ARM::VLD3d32:
2753     case ARM::VLD3d8_UPD:
2754     case ARM::VLD3d16_UPD:
2755     case ARM::VLD3d32_UPD:
2756     case ARM::VLD4d8:
2757     case ARM::VLD4d16:
2758     case ARM::VLD4d32:
2759     case ARM::VLD4d8_UPD:
2760     case ARM::VLD4d16_UPD:
2761     case ARM::VLD4d32_UPD:
2762       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
2763         return MCDisassembler::Fail;
2764       break;
2765     case ARM::VLD3q8:
2766     case ARM::VLD3q16:
2767     case ARM::VLD3q32:
2768     case ARM::VLD3q8_UPD:
2769     case ARM::VLD3q16_UPD:
2770     case ARM::VLD3q32_UPD:
2771     case ARM::VLD4q8:
2772     case ARM::VLD4q16:
2773     case ARM::VLD4q32:
2774     case ARM::VLD4q8_UPD:
2775     case ARM::VLD4q16_UPD:
2776     case ARM::VLD4q32_UPD:
2777       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2778         return MCDisassembler::Fail;
2779       break;
2780     default:
2781       break;
2782   }
2783 
2784   // Third output register
2785   switch(Inst.getOpcode()) {
2786     case ARM::VLD3d8:
2787     case ARM::VLD3d16:
2788     case ARM::VLD3d32:
2789     case ARM::VLD3d8_UPD:
2790     case ARM::VLD3d16_UPD:
2791     case ARM::VLD3d32_UPD:
2792     case ARM::VLD4d8:
2793     case ARM::VLD4d16:
2794     case ARM::VLD4d32:
2795     case ARM::VLD4d8_UPD:
2796     case ARM::VLD4d16_UPD:
2797     case ARM::VLD4d32_UPD:
2798       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2799         return MCDisassembler::Fail;
2800       break;
2801     case ARM::VLD3q8:
2802     case ARM::VLD3q16:
2803     case ARM::VLD3q32:
2804     case ARM::VLD3q8_UPD:
2805     case ARM::VLD3q16_UPD:
2806     case ARM::VLD3q32_UPD:
2807     case ARM::VLD4q8:
2808     case ARM::VLD4q16:
2809     case ARM::VLD4q32:
2810     case ARM::VLD4q8_UPD:
2811     case ARM::VLD4q16_UPD:
2812     case ARM::VLD4q32_UPD:
2813       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
2814         return MCDisassembler::Fail;
2815       break;
2816     default:
2817       break;
2818   }
2819 
2820   // Fourth output register
2821   switch (Inst.getOpcode()) {
2822     case ARM::VLD4d8:
2823     case ARM::VLD4d16:
2824     case ARM::VLD4d32:
2825     case ARM::VLD4d8_UPD:
2826     case ARM::VLD4d16_UPD:
2827     case ARM::VLD4d32_UPD:
2828       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
2829         return MCDisassembler::Fail;
2830       break;
2831     case ARM::VLD4q8:
2832     case ARM::VLD4q16:
2833     case ARM::VLD4q32:
2834     case ARM::VLD4q8_UPD:
2835     case ARM::VLD4q16_UPD:
2836     case ARM::VLD4q32_UPD:
2837       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
2838         return MCDisassembler::Fail;
2839       break;
2840     default:
2841       break;
2842   }
2843 
2844   // Writeback operand
2845   switch (Inst.getOpcode()) {
2846     case ARM::VLD1d8wb_fixed:
2847     case ARM::VLD1d16wb_fixed:
2848     case ARM::VLD1d32wb_fixed:
2849     case ARM::VLD1d64wb_fixed:
2850     case ARM::VLD1d8wb_register:
2851     case ARM::VLD1d16wb_register:
2852     case ARM::VLD1d32wb_register:
2853     case ARM::VLD1d64wb_register:
2854     case ARM::VLD1q8wb_fixed:
2855     case ARM::VLD1q16wb_fixed:
2856     case ARM::VLD1q32wb_fixed:
2857     case ARM::VLD1q64wb_fixed:
2858     case ARM::VLD1q8wb_register:
2859     case ARM::VLD1q16wb_register:
2860     case ARM::VLD1q32wb_register:
2861     case ARM::VLD1q64wb_register:
2862     case ARM::VLD1d8Twb_fixed:
2863     case ARM::VLD1d8Twb_register:
2864     case ARM::VLD1d16Twb_fixed:
2865     case ARM::VLD1d16Twb_register:
2866     case ARM::VLD1d32Twb_fixed:
2867     case ARM::VLD1d32Twb_register:
2868     case ARM::VLD1d64Twb_fixed:
2869     case ARM::VLD1d64Twb_register:
2870     case ARM::VLD1d8Qwb_fixed:
2871     case ARM::VLD1d8Qwb_register:
2872     case ARM::VLD1d16Qwb_fixed:
2873     case ARM::VLD1d16Qwb_register:
2874     case ARM::VLD1d32Qwb_fixed:
2875     case ARM::VLD1d32Qwb_register:
2876     case ARM::VLD1d64Qwb_fixed:
2877     case ARM::VLD1d64Qwb_register:
2878     case ARM::VLD2d8wb_fixed:
2879     case ARM::VLD2d16wb_fixed:
2880     case ARM::VLD2d32wb_fixed:
2881     case ARM::VLD2q8wb_fixed:
2882     case ARM::VLD2q16wb_fixed:
2883     case ARM::VLD2q32wb_fixed:
2884     case ARM::VLD2d8wb_register:
2885     case ARM::VLD2d16wb_register:
2886     case ARM::VLD2d32wb_register:
2887     case ARM::VLD2q8wb_register:
2888     case ARM::VLD2q16wb_register:
2889     case ARM::VLD2q32wb_register:
2890     case ARM::VLD2b8wb_fixed:
2891     case ARM::VLD2b16wb_fixed:
2892     case ARM::VLD2b32wb_fixed:
2893     case ARM::VLD2b8wb_register:
2894     case ARM::VLD2b16wb_register:
2895     case ARM::VLD2b32wb_register:
2896       Inst.addOperand(MCOperand::createImm(0));
2897       break;
2898     case ARM::VLD3d8_UPD:
2899     case ARM::VLD3d16_UPD:
2900     case ARM::VLD3d32_UPD:
2901     case ARM::VLD3q8_UPD:
2902     case ARM::VLD3q16_UPD:
2903     case ARM::VLD3q32_UPD:
2904     case ARM::VLD4d8_UPD:
2905     case ARM::VLD4d16_UPD:
2906     case ARM::VLD4d32_UPD:
2907     case ARM::VLD4q8_UPD:
2908     case ARM::VLD4q16_UPD:
2909     case ARM::VLD4q32_UPD:
2910       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
2911         return MCDisassembler::Fail;
2912       break;
2913     default:
2914       break;
2915   }
2916 
2917   // AddrMode6 Base (register+alignment)
2918   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
2919     return MCDisassembler::Fail;
2920 
2921   // AddrMode6 Offset (register)
2922   switch (Inst.getOpcode()) {
2923   default:
2924     // The below have been updated to have explicit am6offset split
2925     // between fixed and register offset. For those instructions not
2926     // yet updated, we need to add an additional reg0 operand for the
2927     // fixed variant.
2928     //
2929     // The fixed offset encodes as Rm == 0xd, so we check for that.
2930     if (Rm == 0xd) {
2931       Inst.addOperand(MCOperand::createReg(0));
2932       break;
2933     }
2934     // Fall through to handle the register offset variant.
2935     LLVM_FALLTHROUGH;
2936   case ARM::VLD1d8wb_fixed:
2937   case ARM::VLD1d16wb_fixed:
2938   case ARM::VLD1d32wb_fixed:
2939   case ARM::VLD1d64wb_fixed:
2940   case ARM::VLD1d8Twb_fixed:
2941   case ARM::VLD1d16Twb_fixed:
2942   case ARM::VLD1d32Twb_fixed:
2943   case ARM::VLD1d64Twb_fixed:
2944   case ARM::VLD1d8Qwb_fixed:
2945   case ARM::VLD1d16Qwb_fixed:
2946   case ARM::VLD1d32Qwb_fixed:
2947   case ARM::VLD1d64Qwb_fixed:
2948   case ARM::VLD1d8wb_register:
2949   case ARM::VLD1d16wb_register:
2950   case ARM::VLD1d32wb_register:
2951   case ARM::VLD1d64wb_register:
2952   case ARM::VLD1q8wb_fixed:
2953   case ARM::VLD1q16wb_fixed:
2954   case ARM::VLD1q32wb_fixed:
2955   case ARM::VLD1q64wb_fixed:
2956   case ARM::VLD1q8wb_register:
2957   case ARM::VLD1q16wb_register:
2958   case ARM::VLD1q32wb_register:
2959   case ARM::VLD1q64wb_register:
2960     // The fixed offset post-increment encodes Rm == 0xd. The no-writeback
2961     // variant encodes Rm == 0xf. Anything else is a register offset post-
2962     // increment and we need to add the register operand to the instruction.
2963     if (Rm != 0xD && Rm != 0xF &&
2964         !Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2965       return MCDisassembler::Fail;
2966     break;
2967   case ARM::VLD2d8wb_fixed:
2968   case ARM::VLD2d16wb_fixed:
2969   case ARM::VLD2d32wb_fixed:
2970   case ARM::VLD2b8wb_fixed:
2971   case ARM::VLD2b16wb_fixed:
2972   case ARM::VLD2b32wb_fixed:
2973   case ARM::VLD2q8wb_fixed:
2974   case ARM::VLD2q16wb_fixed:
2975   case ARM::VLD2q32wb_fixed:
2976     break;
2977   }
2978 
2979   return S;
2980 }
2981 
2982 static DecodeStatus DecodeVLDST1Instruction(MCInst &Inst, unsigned Insn,
2983                                    uint64_t Address, const void *Decoder) {
2984   unsigned type = fieldFromInstruction(Insn, 8, 4);
2985   unsigned align = fieldFromInstruction(Insn, 4, 2);
2986   if (type == 6 && (align & 2)) return MCDisassembler::Fail;
2987   if (type == 7 && (align & 2)) return MCDisassembler::Fail;
2988   if (type == 10 && align == 3) return MCDisassembler::Fail;
2989 
2990   unsigned load = fieldFromInstruction(Insn, 21, 1);
2991   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2992               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2993 }
2994 
2995 static DecodeStatus DecodeVLDST2Instruction(MCInst &Inst, unsigned Insn,
2996                                    uint64_t Address, const void *Decoder) {
2997   unsigned size = fieldFromInstruction(Insn, 6, 2);
2998   if (size == 3) return MCDisassembler::Fail;
2999 
3000   unsigned type = fieldFromInstruction(Insn, 8, 4);
3001   unsigned align = fieldFromInstruction(Insn, 4, 2);
3002   if (type == 8 && align == 3) return MCDisassembler::Fail;
3003   if (type == 9 && align == 3) return MCDisassembler::Fail;
3004 
3005   unsigned load = fieldFromInstruction(Insn, 21, 1);
3006   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
3007               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
3008 }
3009 
3010 static DecodeStatus DecodeVLDST3Instruction(MCInst &Inst, unsigned Insn,
3011                                    uint64_t Address, const void *Decoder) {
3012   unsigned size = fieldFromInstruction(Insn, 6, 2);
3013   if (size == 3) return MCDisassembler::Fail;
3014 
3015   unsigned align = fieldFromInstruction(Insn, 4, 2);
3016   if (align & 2) return MCDisassembler::Fail;
3017 
3018   unsigned load = fieldFromInstruction(Insn, 21, 1);
3019   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
3020               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
3021 }
3022 
3023 static DecodeStatus DecodeVLDST4Instruction(MCInst &Inst, unsigned Insn,
3024                                    uint64_t Address, const void *Decoder) {
3025   unsigned size = fieldFromInstruction(Insn, 6, 2);
3026   if (size == 3) return MCDisassembler::Fail;
3027 
3028   unsigned load = fieldFromInstruction(Insn, 21, 1);
3029   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
3030               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
3031 }
3032 
3033 static DecodeStatus DecodeVSTInstruction(MCInst &Inst, unsigned Insn,
3034                                  uint64_t Address, const void *Decoder) {
3035   DecodeStatus S = MCDisassembler::Success;
3036 
3037   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3038   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3039   unsigned wb = fieldFromInstruction(Insn, 16, 4);
3040   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3041   Rn |= fieldFromInstruction(Insn, 4, 2) << 4;
3042   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3043 
3044   // Writeback Operand
3045   switch (Inst.getOpcode()) {
3046     case ARM::VST1d8wb_fixed:
3047     case ARM::VST1d16wb_fixed:
3048     case ARM::VST1d32wb_fixed:
3049     case ARM::VST1d64wb_fixed:
3050     case ARM::VST1d8wb_register:
3051     case ARM::VST1d16wb_register:
3052     case ARM::VST1d32wb_register:
3053     case ARM::VST1d64wb_register:
3054     case ARM::VST1q8wb_fixed:
3055     case ARM::VST1q16wb_fixed:
3056     case ARM::VST1q32wb_fixed:
3057     case ARM::VST1q64wb_fixed:
3058     case ARM::VST1q8wb_register:
3059     case ARM::VST1q16wb_register:
3060     case ARM::VST1q32wb_register:
3061     case ARM::VST1q64wb_register:
3062     case ARM::VST1d8Twb_fixed:
3063     case ARM::VST1d16Twb_fixed:
3064     case ARM::VST1d32Twb_fixed:
3065     case ARM::VST1d64Twb_fixed:
3066     case ARM::VST1d8Twb_register:
3067     case ARM::VST1d16Twb_register:
3068     case ARM::VST1d32Twb_register:
3069     case ARM::VST1d64Twb_register:
3070     case ARM::VST1d8Qwb_fixed:
3071     case ARM::VST1d16Qwb_fixed:
3072     case ARM::VST1d32Qwb_fixed:
3073     case ARM::VST1d64Qwb_fixed:
3074     case ARM::VST1d8Qwb_register:
3075     case ARM::VST1d16Qwb_register:
3076     case ARM::VST1d32Qwb_register:
3077     case ARM::VST1d64Qwb_register:
3078     case ARM::VST2d8wb_fixed:
3079     case ARM::VST2d16wb_fixed:
3080     case ARM::VST2d32wb_fixed:
3081     case ARM::VST2d8wb_register:
3082     case ARM::VST2d16wb_register:
3083     case ARM::VST2d32wb_register:
3084     case ARM::VST2q8wb_fixed:
3085     case ARM::VST2q16wb_fixed:
3086     case ARM::VST2q32wb_fixed:
3087     case ARM::VST2q8wb_register:
3088     case ARM::VST2q16wb_register:
3089     case ARM::VST2q32wb_register:
3090     case ARM::VST2b8wb_fixed:
3091     case ARM::VST2b16wb_fixed:
3092     case ARM::VST2b32wb_fixed:
3093     case ARM::VST2b8wb_register:
3094     case ARM::VST2b16wb_register:
3095     case ARM::VST2b32wb_register:
3096       if (Rm == 0xF)
3097         return MCDisassembler::Fail;
3098       Inst.addOperand(MCOperand::createImm(0));
3099       break;
3100     case ARM::VST3d8_UPD:
3101     case ARM::VST3d16_UPD:
3102     case ARM::VST3d32_UPD:
3103     case ARM::VST3q8_UPD:
3104     case ARM::VST3q16_UPD:
3105     case ARM::VST3q32_UPD:
3106     case ARM::VST4d8_UPD:
3107     case ARM::VST4d16_UPD:
3108     case ARM::VST4d32_UPD:
3109     case ARM::VST4q8_UPD:
3110     case ARM::VST4q16_UPD:
3111     case ARM::VST4q32_UPD:
3112       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
3113         return MCDisassembler::Fail;
3114       break;
3115     default:
3116       break;
3117   }
3118 
3119   // AddrMode6 Base (register+alignment)
3120   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
3121     return MCDisassembler::Fail;
3122 
3123   // AddrMode6 Offset (register)
3124   switch (Inst.getOpcode()) {
3125     default:
3126       if (Rm == 0xD)
3127         Inst.addOperand(MCOperand::createReg(0));
3128       else if (Rm != 0xF) {
3129         if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3130           return MCDisassembler::Fail;
3131       }
3132       break;
3133     case ARM::VST1d8wb_fixed:
3134     case ARM::VST1d16wb_fixed:
3135     case ARM::VST1d32wb_fixed:
3136     case ARM::VST1d64wb_fixed:
3137     case ARM::VST1q8wb_fixed:
3138     case ARM::VST1q16wb_fixed:
3139     case ARM::VST1q32wb_fixed:
3140     case ARM::VST1q64wb_fixed:
3141     case ARM::VST1d8Twb_fixed:
3142     case ARM::VST1d16Twb_fixed:
3143     case ARM::VST1d32Twb_fixed:
3144     case ARM::VST1d64Twb_fixed:
3145     case ARM::VST1d8Qwb_fixed:
3146     case ARM::VST1d16Qwb_fixed:
3147     case ARM::VST1d32Qwb_fixed:
3148     case ARM::VST1d64Qwb_fixed:
3149     case ARM::VST2d8wb_fixed:
3150     case ARM::VST2d16wb_fixed:
3151     case ARM::VST2d32wb_fixed:
3152     case ARM::VST2q8wb_fixed:
3153     case ARM::VST2q16wb_fixed:
3154     case ARM::VST2q32wb_fixed:
3155     case ARM::VST2b8wb_fixed:
3156     case ARM::VST2b16wb_fixed:
3157     case ARM::VST2b32wb_fixed:
3158       break;
3159   }
3160 
3161   // First input register
3162   switch (Inst.getOpcode()) {
3163   case ARM::VST1q16:
3164   case ARM::VST1q32:
3165   case ARM::VST1q64:
3166   case ARM::VST1q8:
3167   case ARM::VST1q16wb_fixed:
3168   case ARM::VST1q16wb_register:
3169   case ARM::VST1q32wb_fixed:
3170   case ARM::VST1q32wb_register:
3171   case ARM::VST1q64wb_fixed:
3172   case ARM::VST1q64wb_register:
3173   case ARM::VST1q8wb_fixed:
3174   case ARM::VST1q8wb_register:
3175   case ARM::VST2d16:
3176   case ARM::VST2d32:
3177   case ARM::VST2d8:
3178   case ARM::VST2d16wb_fixed:
3179   case ARM::VST2d16wb_register:
3180   case ARM::VST2d32wb_fixed:
3181   case ARM::VST2d32wb_register:
3182   case ARM::VST2d8wb_fixed:
3183   case ARM::VST2d8wb_register:
3184     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3185       return MCDisassembler::Fail;
3186     break;
3187   case ARM::VST2b16:
3188   case ARM::VST2b32:
3189   case ARM::VST2b8:
3190   case ARM::VST2b16wb_fixed:
3191   case ARM::VST2b16wb_register:
3192   case ARM::VST2b32wb_fixed:
3193   case ARM::VST2b32wb_register:
3194   case ARM::VST2b8wb_fixed:
3195   case ARM::VST2b8wb_register:
3196     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
3197       return MCDisassembler::Fail;
3198     break;
3199   default:
3200     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3201       return MCDisassembler::Fail;
3202   }
3203 
3204   // Second input register
3205   switch (Inst.getOpcode()) {
3206     case ARM::VST3d8:
3207     case ARM::VST3d16:
3208     case ARM::VST3d32:
3209     case ARM::VST3d8_UPD:
3210     case ARM::VST3d16_UPD:
3211     case ARM::VST3d32_UPD:
3212     case ARM::VST4d8:
3213     case ARM::VST4d16:
3214     case ARM::VST4d32:
3215     case ARM::VST4d8_UPD:
3216     case ARM::VST4d16_UPD:
3217     case ARM::VST4d32_UPD:
3218       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
3219         return MCDisassembler::Fail;
3220       break;
3221     case ARM::VST3q8:
3222     case ARM::VST3q16:
3223     case ARM::VST3q32:
3224     case ARM::VST3q8_UPD:
3225     case ARM::VST3q16_UPD:
3226     case ARM::VST3q32_UPD:
3227     case ARM::VST4q8:
3228     case ARM::VST4q16:
3229     case ARM::VST4q32:
3230     case ARM::VST4q8_UPD:
3231     case ARM::VST4q16_UPD:
3232     case ARM::VST4q32_UPD:
3233       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
3234         return MCDisassembler::Fail;
3235       break;
3236     default:
3237       break;
3238   }
3239 
3240   // Third input register
3241   switch (Inst.getOpcode()) {
3242     case ARM::VST3d8:
3243     case ARM::VST3d16:
3244     case ARM::VST3d32:
3245     case ARM::VST3d8_UPD:
3246     case ARM::VST3d16_UPD:
3247     case ARM::VST3d32_UPD:
3248     case ARM::VST4d8:
3249     case ARM::VST4d16:
3250     case ARM::VST4d32:
3251     case ARM::VST4d8_UPD:
3252     case ARM::VST4d16_UPD:
3253     case ARM::VST4d32_UPD:
3254       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
3255         return MCDisassembler::Fail;
3256       break;
3257     case ARM::VST3q8:
3258     case ARM::VST3q16:
3259     case ARM::VST3q32:
3260     case ARM::VST3q8_UPD:
3261     case ARM::VST3q16_UPD:
3262     case ARM::VST3q32_UPD:
3263     case ARM::VST4q8:
3264     case ARM::VST4q16:
3265     case ARM::VST4q32:
3266     case ARM::VST4q8_UPD:
3267     case ARM::VST4q16_UPD:
3268     case ARM::VST4q32_UPD:
3269       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
3270         return MCDisassembler::Fail;
3271       break;
3272     default:
3273       break;
3274   }
3275 
3276   // Fourth input register
3277   switch (Inst.getOpcode()) {
3278     case ARM::VST4d8:
3279     case ARM::VST4d16:
3280     case ARM::VST4d32:
3281     case ARM::VST4d8_UPD:
3282     case ARM::VST4d16_UPD:
3283     case ARM::VST4d32_UPD:
3284       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
3285         return MCDisassembler::Fail;
3286       break;
3287     case ARM::VST4q8:
3288     case ARM::VST4q16:
3289     case ARM::VST4q32:
3290     case ARM::VST4q8_UPD:
3291     case ARM::VST4q16_UPD:
3292     case ARM::VST4q32_UPD:
3293       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
3294         return MCDisassembler::Fail;
3295       break;
3296     default:
3297       break;
3298   }
3299 
3300   return S;
3301 }
3302 
3303 static DecodeStatus DecodeVLD1DupInstruction(MCInst &Inst, unsigned Insn,
3304                                     uint64_t Address, const void *Decoder) {
3305   DecodeStatus S = MCDisassembler::Success;
3306 
3307   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3308   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3309   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3310   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3311   unsigned align = fieldFromInstruction(Insn, 4, 1);
3312   unsigned size = fieldFromInstruction(Insn, 6, 2);
3313 
3314   if (size == 0 && align == 1)
3315     return MCDisassembler::Fail;
3316   align *= (1 << size);
3317 
3318   switch (Inst.getOpcode()) {
3319   case ARM::VLD1DUPq16: case ARM::VLD1DUPq32: case ARM::VLD1DUPq8:
3320   case ARM::VLD1DUPq16wb_fixed: case ARM::VLD1DUPq16wb_register:
3321   case ARM::VLD1DUPq32wb_fixed: case ARM::VLD1DUPq32wb_register:
3322   case ARM::VLD1DUPq8wb_fixed: case ARM::VLD1DUPq8wb_register:
3323     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3324       return MCDisassembler::Fail;
3325     break;
3326   default:
3327     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3328       return MCDisassembler::Fail;
3329     break;
3330   }
3331   if (Rm != 0xF) {
3332     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3333       return MCDisassembler::Fail;
3334   }
3335 
3336   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3337     return MCDisassembler::Fail;
3338   Inst.addOperand(MCOperand::createImm(align));
3339 
3340   // The fixed offset post-increment encodes Rm == 0xd. The no-writeback
3341   // variant encodes Rm == 0xf. Anything else is a register offset post-
3342   // increment and we need to add the register operand to the instruction.
3343   if (Rm != 0xD && Rm != 0xF &&
3344       !Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3345     return MCDisassembler::Fail;
3346 
3347   return S;
3348 }
3349 
3350 static DecodeStatus DecodeVLD2DupInstruction(MCInst &Inst, unsigned Insn,
3351                                     uint64_t Address, const void *Decoder) {
3352   DecodeStatus S = MCDisassembler::Success;
3353 
3354   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3355   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3356   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3357   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3358   unsigned align = fieldFromInstruction(Insn, 4, 1);
3359   unsigned size = 1 << fieldFromInstruction(Insn, 6, 2);
3360   align *= 2*size;
3361 
3362   switch (Inst.getOpcode()) {
3363   case ARM::VLD2DUPd16: case ARM::VLD2DUPd32: case ARM::VLD2DUPd8:
3364   case ARM::VLD2DUPd16wb_fixed: case ARM::VLD2DUPd16wb_register:
3365   case ARM::VLD2DUPd32wb_fixed: case ARM::VLD2DUPd32wb_register:
3366   case ARM::VLD2DUPd8wb_fixed: case ARM::VLD2DUPd8wb_register:
3367     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3368       return MCDisassembler::Fail;
3369     break;
3370   case ARM::VLD2DUPd16x2: case ARM::VLD2DUPd32x2: case ARM::VLD2DUPd8x2:
3371   case ARM::VLD2DUPd16x2wb_fixed: case ARM::VLD2DUPd16x2wb_register:
3372   case ARM::VLD2DUPd32x2wb_fixed: case ARM::VLD2DUPd32x2wb_register:
3373   case ARM::VLD2DUPd8x2wb_fixed: case ARM::VLD2DUPd8x2wb_register:
3374     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
3375       return MCDisassembler::Fail;
3376     break;
3377   default:
3378     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3379       return MCDisassembler::Fail;
3380     break;
3381   }
3382 
3383   if (Rm != 0xF)
3384     Inst.addOperand(MCOperand::createImm(0));
3385 
3386   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3387     return MCDisassembler::Fail;
3388   Inst.addOperand(MCOperand::createImm(align));
3389 
3390   if (Rm != 0xD && Rm != 0xF) {
3391     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3392       return MCDisassembler::Fail;
3393   }
3394 
3395   return S;
3396 }
3397 
3398 static DecodeStatus DecodeVLD3DupInstruction(MCInst &Inst, unsigned Insn,
3399                                     uint64_t Address, const void *Decoder) {
3400   DecodeStatus S = MCDisassembler::Success;
3401 
3402   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3403   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3404   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3405   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3406   unsigned inc = fieldFromInstruction(Insn, 5, 1) + 1;
3407 
3408   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3409     return MCDisassembler::Fail;
3410   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
3411     return MCDisassembler::Fail;
3412   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
3413     return MCDisassembler::Fail;
3414   if (Rm != 0xF) {
3415     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3416       return MCDisassembler::Fail;
3417   }
3418 
3419   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3420     return MCDisassembler::Fail;
3421   Inst.addOperand(MCOperand::createImm(0));
3422 
3423   if (Rm == 0xD)
3424     Inst.addOperand(MCOperand::createReg(0));
3425   else if (Rm != 0xF) {
3426     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3427       return MCDisassembler::Fail;
3428   }
3429 
3430   return S;
3431 }
3432 
3433 static DecodeStatus DecodeVLD4DupInstruction(MCInst &Inst, unsigned Insn,
3434                                     uint64_t Address, const void *Decoder) {
3435   DecodeStatus S = MCDisassembler::Success;
3436 
3437   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3438   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3439   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3440   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3441   unsigned size = fieldFromInstruction(Insn, 6, 2);
3442   unsigned inc = fieldFromInstruction(Insn, 5, 1) + 1;
3443   unsigned align = fieldFromInstruction(Insn, 4, 1);
3444 
3445   if (size == 0x3) {
3446     if (align == 0)
3447       return MCDisassembler::Fail;
3448     align = 16;
3449   } else {
3450     if (size == 2) {
3451       align *= 8;
3452     } else {
3453       size = 1 << size;
3454       align *= 4*size;
3455     }
3456   }
3457 
3458   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3459     return MCDisassembler::Fail;
3460   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
3461     return MCDisassembler::Fail;
3462   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
3463     return MCDisassembler::Fail;
3464   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3*inc)%32, Address, Decoder)))
3465     return MCDisassembler::Fail;
3466   if (Rm != 0xF) {
3467     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3468       return MCDisassembler::Fail;
3469   }
3470 
3471   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3472     return MCDisassembler::Fail;
3473   Inst.addOperand(MCOperand::createImm(align));
3474 
3475   if (Rm == 0xD)
3476     Inst.addOperand(MCOperand::createReg(0));
3477   else if (Rm != 0xF) {
3478     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3479       return MCDisassembler::Fail;
3480   }
3481 
3482   return S;
3483 }
3484 
3485 static DecodeStatus
3486 DecodeVMOVModImmInstruction(MCInst &Inst, unsigned Insn,
3487                             uint64_t Address, const void *Decoder) {
3488   DecodeStatus S = MCDisassembler::Success;
3489 
3490   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3491   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3492   unsigned imm = fieldFromInstruction(Insn, 0, 4);
3493   imm |= fieldFromInstruction(Insn, 16, 3) << 4;
3494   imm |= fieldFromInstruction(Insn, 24, 1) << 7;
3495   imm |= fieldFromInstruction(Insn, 8, 4) << 8;
3496   imm |= fieldFromInstruction(Insn, 5, 1) << 12;
3497   unsigned Q = fieldFromInstruction(Insn, 6, 1);
3498 
3499   if (Q) {
3500     if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3501     return MCDisassembler::Fail;
3502   } else {
3503     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3504     return MCDisassembler::Fail;
3505   }
3506 
3507   Inst.addOperand(MCOperand::createImm(imm));
3508 
3509   switch (Inst.getOpcode()) {
3510     case ARM::VORRiv4i16:
3511     case ARM::VORRiv2i32:
3512     case ARM::VBICiv4i16:
3513     case ARM::VBICiv2i32:
3514       if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3515         return MCDisassembler::Fail;
3516       break;
3517     case ARM::VORRiv8i16:
3518     case ARM::VORRiv4i32:
3519     case ARM::VBICiv8i16:
3520     case ARM::VBICiv4i32:
3521       if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3522         return MCDisassembler::Fail;
3523       break;
3524     default:
3525       break;
3526   }
3527 
3528   return S;
3529 }
3530 
3531 static DecodeStatus
3532 DecodeMVEModImmInstruction(MCInst &Inst, unsigned Insn,
3533                            uint64_t Address, const void *Decoder) {
3534   DecodeStatus S = MCDisassembler::Success;
3535 
3536   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
3537                  fieldFromInstruction(Insn, 13, 3));
3538   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
3539   unsigned imm = fieldFromInstruction(Insn, 0, 4);
3540   imm |= fieldFromInstruction(Insn, 16, 3) << 4;
3541   imm |= fieldFromInstruction(Insn, 28, 1) << 7;
3542   imm |= cmode                             << 8;
3543   imm |= fieldFromInstruction(Insn, 5, 1)  << 12;
3544 
3545   if (cmode == 0xF && Inst.getOpcode() == ARM::MVE_VMVNimmi32)
3546     return MCDisassembler::Fail;
3547 
3548   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
3549     return MCDisassembler::Fail;
3550 
3551   Inst.addOperand(MCOperand::createImm(imm));
3552 
3553   Inst.addOperand(MCOperand::createImm(ARMVCC::None));
3554   Inst.addOperand(MCOperand::createReg(0));
3555   Inst.addOperand(MCOperand::createImm(0));
3556 
3557   return S;
3558 }
3559 
3560 static DecodeStatus DecodeMVEVADCInstruction(MCInst &Inst, unsigned Insn,
3561                                uint64_t Address, const void *Decoder) {
3562   DecodeStatus S = MCDisassembler::Success;
3563 
3564   unsigned Qd = fieldFromInstruction(Insn, 13, 3);
3565   Qd |= fieldFromInstruction(Insn, 22, 1) << 3;
3566   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
3567     return MCDisassembler::Fail;
3568   Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
3569 
3570   unsigned Qn = fieldFromInstruction(Insn, 17, 3);
3571   Qn |= fieldFromInstruction(Insn, 7, 1) << 3;
3572   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qn, Address, Decoder)))
3573     return MCDisassembler::Fail;
3574   unsigned Qm = fieldFromInstruction(Insn, 1, 3);
3575   Qm |= fieldFromInstruction(Insn, 5, 1) << 3;
3576   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
3577     return MCDisassembler::Fail;
3578   if (!fieldFromInstruction(Insn, 12, 1)) // I bit clear => need input FPSCR
3579     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
3580   Inst.addOperand(MCOperand::createImm(Qd));
3581 
3582   return S;
3583 }
3584 
3585 static DecodeStatus DecodeVSHLMaxInstruction(MCInst &Inst, unsigned Insn,
3586                                         uint64_t Address, const void *Decoder) {
3587   DecodeStatus S = MCDisassembler::Success;
3588 
3589   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3590   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3591   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3592   Rm |= fieldFromInstruction(Insn, 5, 1) << 4;
3593   unsigned size = fieldFromInstruction(Insn, 18, 2);
3594 
3595   if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3596     return MCDisassembler::Fail;
3597   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
3598     return MCDisassembler::Fail;
3599   Inst.addOperand(MCOperand::createImm(8 << size));
3600 
3601   return S;
3602 }
3603 
3604 static DecodeStatus DecodeShiftRight8Imm(MCInst &Inst, unsigned Val,
3605                                uint64_t Address, const void *Decoder) {
3606   Inst.addOperand(MCOperand::createImm(8 - Val));
3607   return MCDisassembler::Success;
3608 }
3609 
3610 static DecodeStatus DecodeShiftRight16Imm(MCInst &Inst, unsigned Val,
3611                                uint64_t Address, const void *Decoder) {
3612   Inst.addOperand(MCOperand::createImm(16 - Val));
3613   return MCDisassembler::Success;
3614 }
3615 
3616 static DecodeStatus DecodeShiftRight32Imm(MCInst &Inst, unsigned Val,
3617                                uint64_t Address, const void *Decoder) {
3618   Inst.addOperand(MCOperand::createImm(32 - Val));
3619   return MCDisassembler::Success;
3620 }
3621 
3622 static DecodeStatus DecodeShiftRight64Imm(MCInst &Inst, unsigned Val,
3623                                uint64_t Address, const void *Decoder) {
3624   Inst.addOperand(MCOperand::createImm(64 - Val));
3625   return MCDisassembler::Success;
3626 }
3627 
3628 static DecodeStatus DecodeTBLInstruction(MCInst &Inst, unsigned Insn,
3629                                uint64_t Address, const void *Decoder) {
3630   DecodeStatus S = MCDisassembler::Success;
3631 
3632   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3633   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3634   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3635   Rn |= fieldFromInstruction(Insn, 7, 1) << 4;
3636   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3637   Rm |= fieldFromInstruction(Insn, 5, 1) << 4;
3638   unsigned op = fieldFromInstruction(Insn, 6, 1);
3639 
3640   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3641     return MCDisassembler::Fail;
3642   if (op) {
3643     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3644     return MCDisassembler::Fail; // Writeback
3645   }
3646 
3647   switch (Inst.getOpcode()) {
3648   case ARM::VTBL2:
3649   case ARM::VTBX2:
3650     if (!Check(S, DecodeDPairRegisterClass(Inst, Rn, Address, Decoder)))
3651       return MCDisassembler::Fail;
3652     break;
3653   default:
3654     if (!Check(S, DecodeDPRRegisterClass(Inst, Rn, Address, Decoder)))
3655       return MCDisassembler::Fail;
3656   }
3657 
3658   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
3659     return MCDisassembler::Fail;
3660 
3661   return S;
3662 }
3663 
3664 static DecodeStatus DecodeThumbAddSpecialReg(MCInst &Inst, uint16_t Insn,
3665                                      uint64_t Address, const void *Decoder) {
3666   DecodeStatus S = MCDisassembler::Success;
3667 
3668   unsigned dst = fieldFromInstruction(Insn, 8, 3);
3669   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3670 
3671   if (!Check(S, DecodetGPRRegisterClass(Inst, dst, Address, Decoder)))
3672     return MCDisassembler::Fail;
3673 
3674   switch(Inst.getOpcode()) {
3675     default:
3676       return MCDisassembler::Fail;
3677     case ARM::tADR:
3678       break; // tADR does not explicitly represent the PC as an operand.
3679     case ARM::tADDrSPi:
3680       Inst.addOperand(MCOperand::createReg(ARM::SP));
3681       break;
3682   }
3683 
3684   Inst.addOperand(MCOperand::createImm(imm));
3685   return S;
3686 }
3687 
3688 static DecodeStatus DecodeThumbBROperand(MCInst &Inst, unsigned Val,
3689                                  uint64_t Address, const void *Decoder) {
3690   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<12>(Val<<1) + 4,
3691                                 true, 2, Inst, Decoder))
3692     Inst.addOperand(MCOperand::createImm(SignExtend32<12>(Val << 1)));
3693   return MCDisassembler::Success;
3694 }
3695 
3696 static DecodeStatus DecodeT2BROperand(MCInst &Inst, unsigned Val,
3697                                  uint64_t Address, const void *Decoder) {
3698   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<21>(Val) + 4,
3699                                 true, 4, Inst, Decoder))
3700     Inst.addOperand(MCOperand::createImm(SignExtend32<21>(Val)));
3701   return MCDisassembler::Success;
3702 }
3703 
3704 static DecodeStatus DecodeThumbCmpBROperand(MCInst &Inst, unsigned Val,
3705                                  uint64_t Address, const void *Decoder) {
3706   if (!tryAddingSymbolicOperand(Address, Address + (Val<<1) + 4,
3707                                 true, 2, Inst, Decoder))
3708     Inst.addOperand(MCOperand::createImm(Val << 1));
3709   return MCDisassembler::Success;
3710 }
3711 
3712 static DecodeStatus DecodeThumbAddrModeRR(MCInst &Inst, unsigned Val,
3713                                  uint64_t Address, const void *Decoder) {
3714   DecodeStatus S = MCDisassembler::Success;
3715 
3716   unsigned Rn = fieldFromInstruction(Val, 0, 3);
3717   unsigned Rm = fieldFromInstruction(Val, 3, 3);
3718 
3719   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
3720     return MCDisassembler::Fail;
3721   if (!Check(S, DecodetGPRRegisterClass(Inst, Rm, Address, Decoder)))
3722     return MCDisassembler::Fail;
3723 
3724   return S;
3725 }
3726 
3727 static DecodeStatus DecodeThumbAddrModeIS(MCInst &Inst, unsigned Val,
3728                                   uint64_t Address, const void *Decoder) {
3729   DecodeStatus S = MCDisassembler::Success;
3730 
3731   unsigned Rn = fieldFromInstruction(Val, 0, 3);
3732   unsigned imm = fieldFromInstruction(Val, 3, 5);
3733 
3734   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
3735     return MCDisassembler::Fail;
3736   Inst.addOperand(MCOperand::createImm(imm));
3737 
3738   return S;
3739 }
3740 
3741 static DecodeStatus DecodeThumbAddrModePC(MCInst &Inst, unsigned Val,
3742                                   uint64_t Address, const void *Decoder) {
3743   unsigned imm = Val << 2;
3744 
3745   Inst.addOperand(MCOperand::createImm(imm));
3746   tryAddingPcLoadReferenceComment(Address, (Address & ~2u) + imm + 4, Decoder);
3747 
3748   return MCDisassembler::Success;
3749 }
3750 
3751 static DecodeStatus DecodeThumbAddrModeSP(MCInst &Inst, unsigned Val,
3752                                   uint64_t Address, const void *Decoder) {
3753   Inst.addOperand(MCOperand::createReg(ARM::SP));
3754   Inst.addOperand(MCOperand::createImm(Val));
3755 
3756   return MCDisassembler::Success;
3757 }
3758 
3759 static DecodeStatus DecodeT2AddrModeSOReg(MCInst &Inst, unsigned Val,
3760                                   uint64_t Address, const void *Decoder) {
3761   DecodeStatus S = MCDisassembler::Success;
3762 
3763   unsigned Rn = fieldFromInstruction(Val, 6, 4);
3764   unsigned Rm = fieldFromInstruction(Val, 2, 4);
3765   unsigned imm = fieldFromInstruction(Val, 0, 2);
3766 
3767   // Thumb stores cannot use PC as dest register.
3768   switch (Inst.getOpcode()) {
3769   case ARM::t2STRHs:
3770   case ARM::t2STRBs:
3771   case ARM::t2STRs:
3772     if (Rn == 15)
3773       return MCDisassembler::Fail;
3774     break;
3775   default:
3776     break;
3777   }
3778 
3779   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3780     return MCDisassembler::Fail;
3781   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
3782     return MCDisassembler::Fail;
3783   Inst.addOperand(MCOperand::createImm(imm));
3784 
3785   return S;
3786 }
3787 
3788 static DecodeStatus DecodeT2LoadShift(MCInst &Inst, unsigned Insn,
3789                               uint64_t Address, const void *Decoder) {
3790   DecodeStatus S = MCDisassembler::Success;
3791 
3792   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3793   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3794 
3795   const FeatureBitset &featureBits =
3796     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3797 
3798   bool hasMP = featureBits[ARM::FeatureMP];
3799   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3800 
3801   if (Rn == 15) {
3802     switch (Inst.getOpcode()) {
3803     case ARM::t2LDRBs:
3804       Inst.setOpcode(ARM::t2LDRBpci);
3805       break;
3806     case ARM::t2LDRHs:
3807       Inst.setOpcode(ARM::t2LDRHpci);
3808       break;
3809     case ARM::t2LDRSHs:
3810       Inst.setOpcode(ARM::t2LDRSHpci);
3811       break;
3812     case ARM::t2LDRSBs:
3813       Inst.setOpcode(ARM::t2LDRSBpci);
3814       break;
3815     case ARM::t2LDRs:
3816       Inst.setOpcode(ARM::t2LDRpci);
3817       break;
3818     case ARM::t2PLDs:
3819       Inst.setOpcode(ARM::t2PLDpci);
3820       break;
3821     case ARM::t2PLIs:
3822       Inst.setOpcode(ARM::t2PLIpci);
3823       break;
3824     default:
3825       return MCDisassembler::Fail;
3826     }
3827 
3828     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3829   }
3830 
3831   if (Rt == 15) {
3832     switch (Inst.getOpcode()) {
3833     case ARM::t2LDRSHs:
3834       return MCDisassembler::Fail;
3835     case ARM::t2LDRHs:
3836       Inst.setOpcode(ARM::t2PLDWs);
3837       break;
3838     case ARM::t2LDRSBs:
3839       Inst.setOpcode(ARM::t2PLIs);
3840       break;
3841     default:
3842       break;
3843     }
3844   }
3845 
3846   switch (Inst.getOpcode()) {
3847     case ARM::t2PLDs:
3848       break;
3849     case ARM::t2PLIs:
3850       if (!hasV7Ops)
3851         return MCDisassembler::Fail;
3852       break;
3853     case ARM::t2PLDWs:
3854       if (!hasV7Ops || !hasMP)
3855         return MCDisassembler::Fail;
3856       break;
3857     default:
3858       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3859         return MCDisassembler::Fail;
3860   }
3861 
3862   unsigned addrmode = fieldFromInstruction(Insn, 4, 2);
3863   addrmode |= fieldFromInstruction(Insn, 0, 4) << 2;
3864   addrmode |= fieldFromInstruction(Insn, 16, 4) << 6;
3865   if (!Check(S, DecodeT2AddrModeSOReg(Inst, addrmode, Address, Decoder)))
3866     return MCDisassembler::Fail;
3867 
3868   return S;
3869 }
3870 
3871 static DecodeStatus DecodeT2LoadImm8(MCInst &Inst, unsigned Insn,
3872                                 uint64_t Address, const void* Decoder) {
3873   DecodeStatus S = MCDisassembler::Success;
3874 
3875   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3876   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3877   unsigned U = fieldFromInstruction(Insn, 9, 1);
3878   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3879   imm |= (U << 8);
3880   imm |= (Rn << 9);
3881   unsigned add = fieldFromInstruction(Insn, 9, 1);
3882 
3883   const FeatureBitset &featureBits =
3884     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3885 
3886   bool hasMP = featureBits[ARM::FeatureMP];
3887   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3888 
3889   if (Rn == 15) {
3890     switch (Inst.getOpcode()) {
3891     case ARM::t2LDRi8:
3892       Inst.setOpcode(ARM::t2LDRpci);
3893       break;
3894     case ARM::t2LDRBi8:
3895       Inst.setOpcode(ARM::t2LDRBpci);
3896       break;
3897     case ARM::t2LDRSBi8:
3898       Inst.setOpcode(ARM::t2LDRSBpci);
3899       break;
3900     case ARM::t2LDRHi8:
3901       Inst.setOpcode(ARM::t2LDRHpci);
3902       break;
3903     case ARM::t2LDRSHi8:
3904       Inst.setOpcode(ARM::t2LDRSHpci);
3905       break;
3906     case ARM::t2PLDi8:
3907       Inst.setOpcode(ARM::t2PLDpci);
3908       break;
3909     case ARM::t2PLIi8:
3910       Inst.setOpcode(ARM::t2PLIpci);
3911       break;
3912     default:
3913       return MCDisassembler::Fail;
3914     }
3915     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3916   }
3917 
3918   if (Rt == 15) {
3919     switch (Inst.getOpcode()) {
3920     case ARM::t2LDRSHi8:
3921       return MCDisassembler::Fail;
3922     case ARM::t2LDRHi8:
3923       if (!add)
3924         Inst.setOpcode(ARM::t2PLDWi8);
3925       break;
3926     case ARM::t2LDRSBi8:
3927       Inst.setOpcode(ARM::t2PLIi8);
3928       break;
3929     default:
3930       break;
3931     }
3932   }
3933 
3934   switch (Inst.getOpcode()) {
3935   case ARM::t2PLDi8:
3936     break;
3937   case ARM::t2PLIi8:
3938     if (!hasV7Ops)
3939       return MCDisassembler::Fail;
3940     break;
3941   case ARM::t2PLDWi8:
3942       if (!hasV7Ops || !hasMP)
3943         return MCDisassembler::Fail;
3944       break;
3945   default:
3946     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3947       return MCDisassembler::Fail;
3948   }
3949 
3950   if (!Check(S, DecodeT2AddrModeImm8(Inst, imm, Address, Decoder)))
3951     return MCDisassembler::Fail;
3952   return S;
3953 }
3954 
3955 static DecodeStatus DecodeT2LoadImm12(MCInst &Inst, unsigned Insn,
3956                                 uint64_t Address, const void* Decoder) {
3957   DecodeStatus S = MCDisassembler::Success;
3958 
3959   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3960   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3961   unsigned imm = fieldFromInstruction(Insn, 0, 12);
3962   imm |= (Rn << 13);
3963 
3964   const FeatureBitset &featureBits =
3965     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3966 
3967   bool hasMP = featureBits[ARM::FeatureMP];
3968   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3969 
3970   if (Rn == 15) {
3971     switch (Inst.getOpcode()) {
3972     case ARM::t2LDRi12:
3973       Inst.setOpcode(ARM::t2LDRpci);
3974       break;
3975     case ARM::t2LDRHi12:
3976       Inst.setOpcode(ARM::t2LDRHpci);
3977       break;
3978     case ARM::t2LDRSHi12:
3979       Inst.setOpcode(ARM::t2LDRSHpci);
3980       break;
3981     case ARM::t2LDRBi12:
3982       Inst.setOpcode(ARM::t2LDRBpci);
3983       break;
3984     case ARM::t2LDRSBi12:
3985       Inst.setOpcode(ARM::t2LDRSBpci);
3986       break;
3987     case ARM::t2PLDi12:
3988       Inst.setOpcode(ARM::t2PLDpci);
3989       break;
3990     case ARM::t2PLIi12:
3991       Inst.setOpcode(ARM::t2PLIpci);
3992       break;
3993     default:
3994       return MCDisassembler::Fail;
3995     }
3996     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3997   }
3998 
3999   if (Rt == 15) {
4000     switch (Inst.getOpcode()) {
4001     case ARM::t2LDRSHi12:
4002       return MCDisassembler::Fail;
4003     case ARM::t2LDRHi12:
4004       Inst.setOpcode(ARM::t2PLDWi12);
4005       break;
4006     case ARM::t2LDRSBi12:
4007       Inst.setOpcode(ARM::t2PLIi12);
4008       break;
4009     default:
4010       break;
4011     }
4012   }
4013 
4014   switch (Inst.getOpcode()) {
4015   case ARM::t2PLDi12:
4016     break;
4017   case ARM::t2PLIi12:
4018     if (!hasV7Ops)
4019       return MCDisassembler::Fail;
4020     break;
4021   case ARM::t2PLDWi12:
4022       if (!hasV7Ops || !hasMP)
4023         return MCDisassembler::Fail;
4024       break;
4025   default:
4026     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4027       return MCDisassembler::Fail;
4028   }
4029 
4030   if (!Check(S, DecodeT2AddrModeImm12(Inst, imm, Address, Decoder)))
4031     return MCDisassembler::Fail;
4032   return S;
4033 }
4034 
4035 static DecodeStatus DecodeT2LoadT(MCInst &Inst, unsigned Insn,
4036                                 uint64_t Address, const void* Decoder) {
4037   DecodeStatus S = MCDisassembler::Success;
4038 
4039   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4040   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4041   unsigned imm = fieldFromInstruction(Insn, 0, 8);
4042   imm |= (Rn << 9);
4043 
4044   if (Rn == 15) {
4045     switch (Inst.getOpcode()) {
4046     case ARM::t2LDRT:
4047       Inst.setOpcode(ARM::t2LDRpci);
4048       break;
4049     case ARM::t2LDRBT:
4050       Inst.setOpcode(ARM::t2LDRBpci);
4051       break;
4052     case ARM::t2LDRHT:
4053       Inst.setOpcode(ARM::t2LDRHpci);
4054       break;
4055     case ARM::t2LDRSBT:
4056       Inst.setOpcode(ARM::t2LDRSBpci);
4057       break;
4058     case ARM::t2LDRSHT:
4059       Inst.setOpcode(ARM::t2LDRSHpci);
4060       break;
4061     default:
4062       return MCDisassembler::Fail;
4063     }
4064     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
4065   }
4066 
4067   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
4068     return MCDisassembler::Fail;
4069   if (!Check(S, DecodeT2AddrModeImm8(Inst, imm, Address, Decoder)))
4070     return MCDisassembler::Fail;
4071   return S;
4072 }
4073 
4074 static DecodeStatus DecodeT2LoadLabel(MCInst &Inst, unsigned Insn,
4075                                 uint64_t Address, const void* Decoder) {
4076   DecodeStatus S = MCDisassembler::Success;
4077 
4078   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4079   unsigned U = fieldFromInstruction(Insn, 23, 1);
4080   int imm = fieldFromInstruction(Insn, 0, 12);
4081 
4082   const FeatureBitset &featureBits =
4083     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4084 
4085   bool hasV7Ops = featureBits[ARM::HasV7Ops];
4086 
4087   if (Rt == 15) {
4088     switch (Inst.getOpcode()) {
4089       case ARM::t2LDRBpci:
4090       case ARM::t2LDRHpci:
4091         Inst.setOpcode(ARM::t2PLDpci);
4092         break;
4093       case ARM::t2LDRSBpci:
4094         Inst.setOpcode(ARM::t2PLIpci);
4095         break;
4096       case ARM::t2LDRSHpci:
4097         return MCDisassembler::Fail;
4098       default:
4099         break;
4100     }
4101   }
4102 
4103   switch(Inst.getOpcode()) {
4104   case ARM::t2PLDpci:
4105     break;
4106   case ARM::t2PLIpci:
4107     if (!hasV7Ops)
4108       return MCDisassembler::Fail;
4109     break;
4110   default:
4111     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4112       return MCDisassembler::Fail;
4113   }
4114 
4115   if (!U) {
4116     // Special case for #-0.
4117     if (imm == 0)
4118       imm = INT32_MIN;
4119     else
4120       imm = -imm;
4121   }
4122   Inst.addOperand(MCOperand::createImm(imm));
4123 
4124   return S;
4125 }
4126 
4127 static DecodeStatus DecodeT2Imm8S4(MCInst &Inst, unsigned Val,
4128                            uint64_t Address, const void *Decoder) {
4129   if (Val == 0)
4130     Inst.addOperand(MCOperand::createImm(INT32_MIN));
4131   else {
4132     int imm = Val & 0xFF;
4133 
4134     if (!(Val & 0x100)) imm *= -1;
4135     Inst.addOperand(MCOperand::createImm(imm * 4));
4136   }
4137 
4138   return MCDisassembler::Success;
4139 }
4140 
4141 static DecodeStatus DecodeT2Imm7S4(MCInst &Inst, unsigned Val, uint64_t Address,
4142                                    const void *Decoder) {
4143   if (Val == 0)
4144     Inst.addOperand(MCOperand::createImm(INT32_MIN));
4145   else {
4146     int imm = Val & 0x7F;
4147 
4148     if (!(Val & 0x80))
4149       imm *= -1;
4150     Inst.addOperand(MCOperand::createImm(imm * 4));
4151   }
4152 
4153   return MCDisassembler::Success;
4154 }
4155 
4156 static DecodeStatus DecodeT2AddrModeImm8s4(MCInst &Inst, unsigned Val,
4157                                    uint64_t Address, const void *Decoder) {
4158   DecodeStatus S = MCDisassembler::Success;
4159 
4160   unsigned Rn = fieldFromInstruction(Val, 9, 4);
4161   unsigned imm = fieldFromInstruction(Val, 0, 9);
4162 
4163   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4164     return MCDisassembler::Fail;
4165   if (!Check(S, DecodeT2Imm8S4(Inst, imm, Address, Decoder)))
4166     return MCDisassembler::Fail;
4167 
4168   return S;
4169 }
4170 
4171 static DecodeStatus DecodeT2AddrModeImm7s4(MCInst &Inst, unsigned Val,
4172                                            uint64_t Address,
4173                                            const void *Decoder) {
4174   DecodeStatus S = MCDisassembler::Success;
4175 
4176   unsigned Rn = fieldFromInstruction(Val, 8, 4);
4177   unsigned imm = fieldFromInstruction(Val, 0, 8);
4178 
4179   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4180     return MCDisassembler::Fail;
4181   if (!Check(S, DecodeT2Imm7S4(Inst, imm, Address, Decoder)))
4182     return MCDisassembler::Fail;
4183 
4184   return S;
4185 }
4186 
4187 static DecodeStatus DecodeT2AddrModeImm0_1020s4(MCInst &Inst,unsigned Val,
4188                                    uint64_t Address, const void *Decoder) {
4189   DecodeStatus S = MCDisassembler::Success;
4190 
4191   unsigned Rn = fieldFromInstruction(Val, 8, 4);
4192   unsigned imm = fieldFromInstruction(Val, 0, 8);
4193 
4194   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4195     return MCDisassembler::Fail;
4196 
4197   Inst.addOperand(MCOperand::createImm(imm));
4198 
4199   return S;
4200 }
4201 
4202 static DecodeStatus DecodeT2Imm8(MCInst &Inst, unsigned Val,
4203                          uint64_t Address, const void *Decoder) {
4204   int imm = Val & 0xFF;
4205   if (Val == 0)
4206     imm = INT32_MIN;
4207   else if (!(Val & 0x100))
4208     imm *= -1;
4209   Inst.addOperand(MCOperand::createImm(imm));
4210 
4211   return MCDisassembler::Success;
4212 }
4213 
4214 template<int shift>
4215 static DecodeStatus DecodeT2Imm7(MCInst &Inst, unsigned Val,
4216                          uint64_t Address, const void *Decoder) {
4217   int imm = Val & 0x7F;
4218   if (Val == 0)
4219     imm = INT32_MIN;
4220   else if (!(Val & 0x80))
4221     imm *= -1;
4222   if (imm != INT32_MIN)
4223     imm *= (1U << shift);
4224   Inst.addOperand(MCOperand::createImm(imm));
4225 
4226   return MCDisassembler::Success;
4227 }
4228 
4229 static DecodeStatus DecodeT2AddrModeImm8(MCInst &Inst, unsigned Val,
4230                                  uint64_t Address, const void *Decoder) {
4231   DecodeStatus S = MCDisassembler::Success;
4232 
4233   unsigned Rn = fieldFromInstruction(Val, 9, 4);
4234   unsigned imm = fieldFromInstruction(Val, 0, 9);
4235 
4236   // Thumb stores cannot use PC as dest register.
4237   switch (Inst.getOpcode()) {
4238   case ARM::t2STRT:
4239   case ARM::t2STRBT:
4240   case ARM::t2STRHT:
4241   case ARM::t2STRi8:
4242   case ARM::t2STRHi8:
4243   case ARM::t2STRBi8:
4244     if (Rn == 15)
4245       return MCDisassembler::Fail;
4246     break;
4247   default:
4248     break;
4249   }
4250 
4251   // Some instructions always use an additive offset.
4252   switch (Inst.getOpcode()) {
4253     case ARM::t2LDRT:
4254     case ARM::t2LDRBT:
4255     case ARM::t2LDRHT:
4256     case ARM::t2LDRSBT:
4257     case ARM::t2LDRSHT:
4258     case ARM::t2STRT:
4259     case ARM::t2STRBT:
4260     case ARM::t2STRHT:
4261       imm |= 0x100;
4262       break;
4263     default:
4264       break;
4265   }
4266 
4267   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4268     return MCDisassembler::Fail;
4269   if (!Check(S, DecodeT2Imm8(Inst, imm, Address, Decoder)))
4270     return MCDisassembler::Fail;
4271 
4272   return S;
4273 }
4274 
4275 template<int shift>
4276 static DecodeStatus DecodeTAddrModeImm7(MCInst &Inst, unsigned Val,
4277                                          uint64_t Address,
4278                                          const void *Decoder) {
4279   DecodeStatus S = MCDisassembler::Success;
4280 
4281   unsigned Rn = fieldFromInstruction(Val, 8, 3);
4282   unsigned imm = fieldFromInstruction(Val, 0, 8);
4283 
4284   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
4285     return MCDisassembler::Fail;
4286   if (!Check(S, DecodeT2Imm7<shift>(Inst, imm, Address, Decoder)))
4287     return MCDisassembler::Fail;
4288 
4289   return S;
4290 }
4291 
4292 template<int shift, int WriteBack>
4293 static DecodeStatus DecodeT2AddrModeImm7(MCInst &Inst, unsigned Val,
4294                                          uint64_t Address,
4295                                          const void *Decoder) {
4296   DecodeStatus S = MCDisassembler::Success;
4297 
4298   unsigned Rn = fieldFromInstruction(Val, 8, 4);
4299   unsigned imm = fieldFromInstruction(Val, 0, 8);
4300   if (WriteBack) {
4301     if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
4302       return MCDisassembler::Fail;
4303   } else if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4304     return MCDisassembler::Fail;
4305   if (!Check(S, DecodeT2Imm7<shift>(Inst, imm, Address, Decoder)))
4306     return MCDisassembler::Fail;
4307 
4308   return S;
4309 }
4310 
4311 static DecodeStatus DecodeT2LdStPre(MCInst &Inst, unsigned Insn,
4312                                     uint64_t Address, const void *Decoder) {
4313   DecodeStatus S = MCDisassembler::Success;
4314 
4315   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4316   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4317   unsigned addr = fieldFromInstruction(Insn, 0, 8);
4318   addr |= fieldFromInstruction(Insn, 9, 1) << 8;
4319   addr |= Rn << 9;
4320   unsigned load = fieldFromInstruction(Insn, 20, 1);
4321 
4322   if (Rn == 15) {
4323     switch (Inst.getOpcode()) {
4324     case ARM::t2LDR_PRE:
4325     case ARM::t2LDR_POST:
4326       Inst.setOpcode(ARM::t2LDRpci);
4327       break;
4328     case ARM::t2LDRB_PRE:
4329     case ARM::t2LDRB_POST:
4330       Inst.setOpcode(ARM::t2LDRBpci);
4331       break;
4332     case ARM::t2LDRH_PRE:
4333     case ARM::t2LDRH_POST:
4334       Inst.setOpcode(ARM::t2LDRHpci);
4335       break;
4336     case ARM::t2LDRSB_PRE:
4337     case ARM::t2LDRSB_POST:
4338       if (Rt == 15)
4339         Inst.setOpcode(ARM::t2PLIpci);
4340       else
4341         Inst.setOpcode(ARM::t2LDRSBpci);
4342       break;
4343     case ARM::t2LDRSH_PRE:
4344     case ARM::t2LDRSH_POST:
4345       Inst.setOpcode(ARM::t2LDRSHpci);
4346       break;
4347     default:
4348       return MCDisassembler::Fail;
4349     }
4350     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
4351   }
4352 
4353   if (!load) {
4354     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4355       return MCDisassembler::Fail;
4356   }
4357 
4358   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4359     return MCDisassembler::Fail;
4360 
4361   if (load) {
4362     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4363       return MCDisassembler::Fail;
4364   }
4365 
4366   if (!Check(S, DecodeT2AddrModeImm8(Inst, addr, Address, Decoder)))
4367     return MCDisassembler::Fail;
4368 
4369   return S;
4370 }
4371 
4372 static DecodeStatus DecodeT2AddrModeImm12(MCInst &Inst, unsigned Val,
4373                                   uint64_t Address, const void *Decoder) {
4374   DecodeStatus S = MCDisassembler::Success;
4375 
4376   unsigned Rn = fieldFromInstruction(Val, 13, 4);
4377   unsigned imm = fieldFromInstruction(Val, 0, 12);
4378 
4379   // Thumb stores cannot use PC as dest register.
4380   switch (Inst.getOpcode()) {
4381   case ARM::t2STRi12:
4382   case ARM::t2STRBi12:
4383   case ARM::t2STRHi12:
4384     if (Rn == 15)
4385       return MCDisassembler::Fail;
4386     break;
4387   default:
4388     break;
4389   }
4390 
4391   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4392     return MCDisassembler::Fail;
4393   Inst.addOperand(MCOperand::createImm(imm));
4394 
4395   return S;
4396 }
4397 
4398 static DecodeStatus DecodeThumbAddSPImm(MCInst &Inst, uint16_t Insn,
4399                                 uint64_t Address, const void *Decoder) {
4400   unsigned imm = fieldFromInstruction(Insn, 0, 7);
4401 
4402   Inst.addOperand(MCOperand::createReg(ARM::SP));
4403   Inst.addOperand(MCOperand::createReg(ARM::SP));
4404   Inst.addOperand(MCOperand::createImm(imm));
4405 
4406   return MCDisassembler::Success;
4407 }
4408 
4409 static DecodeStatus DecodeThumbAddSPReg(MCInst &Inst, uint16_t Insn,
4410                                 uint64_t Address, const void *Decoder) {
4411   DecodeStatus S = MCDisassembler::Success;
4412 
4413   if (Inst.getOpcode() == ARM::tADDrSP) {
4414     unsigned Rdm = fieldFromInstruction(Insn, 0, 3);
4415     Rdm |= fieldFromInstruction(Insn, 7, 1) << 3;
4416 
4417     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
4418     return MCDisassembler::Fail;
4419     Inst.addOperand(MCOperand::createReg(ARM::SP));
4420     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
4421     return MCDisassembler::Fail;
4422   } else if (Inst.getOpcode() == ARM::tADDspr) {
4423     unsigned Rm = fieldFromInstruction(Insn, 3, 4);
4424 
4425     Inst.addOperand(MCOperand::createReg(ARM::SP));
4426     Inst.addOperand(MCOperand::createReg(ARM::SP));
4427     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4428     return MCDisassembler::Fail;
4429   }
4430 
4431   return S;
4432 }
4433 
4434 static DecodeStatus DecodeThumbCPS(MCInst &Inst, uint16_t Insn,
4435                            uint64_t Address, const void *Decoder) {
4436   unsigned imod = fieldFromInstruction(Insn, 4, 1) | 0x2;
4437   unsigned flags = fieldFromInstruction(Insn, 0, 3);
4438 
4439   Inst.addOperand(MCOperand::createImm(imod));
4440   Inst.addOperand(MCOperand::createImm(flags));
4441 
4442   return MCDisassembler::Success;
4443 }
4444 
4445 static DecodeStatus DecodePostIdxReg(MCInst &Inst, unsigned Insn,
4446                              uint64_t Address, const void *Decoder) {
4447   DecodeStatus S = MCDisassembler::Success;
4448   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4449   unsigned add = fieldFromInstruction(Insn, 4, 1);
4450 
4451   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
4452     return MCDisassembler::Fail;
4453   Inst.addOperand(MCOperand::createImm(add));
4454 
4455   return S;
4456 }
4457 
4458 static DecodeStatus DecodeMveAddrModeRQ(MCInst &Inst, unsigned Insn,
4459                              uint64_t Address, const void *Decoder) {
4460   DecodeStatus S = MCDisassembler::Success;
4461   unsigned Rn = fieldFromInstruction(Insn, 3, 4);
4462   unsigned Qm = fieldFromInstruction(Insn, 0, 3);
4463 
4464   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4465     return MCDisassembler::Fail;
4466   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
4467     return MCDisassembler::Fail;
4468 
4469   return S;
4470 }
4471 
4472 template<int shift>
4473 static DecodeStatus DecodeMveAddrModeQ(MCInst &Inst, unsigned Insn,
4474                              uint64_t Address, const void *Decoder) {
4475   DecodeStatus S = MCDisassembler::Success;
4476   unsigned Qm = fieldFromInstruction(Insn, 8, 3);
4477   int imm = fieldFromInstruction(Insn, 0, 7);
4478 
4479   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
4480     return MCDisassembler::Fail;
4481 
4482   if(!fieldFromInstruction(Insn, 7, 1)) {
4483     if (imm == 0)
4484       imm = INT32_MIN;                 // indicate -0
4485     else
4486       imm *= -1;
4487   }
4488   if (imm != INT32_MIN)
4489     imm *= (1U << shift);
4490   Inst.addOperand(MCOperand::createImm(imm));
4491 
4492   return S;
4493 }
4494 
4495 static DecodeStatus DecodeThumbBLXOffset(MCInst &Inst, unsigned Val,
4496                                  uint64_t Address, const void *Decoder) {
4497   // Val is passed in as S:J1:J2:imm10H:imm10L:'0'
4498   // Note only one trailing zero not two.  Also the J1 and J2 values are from
4499   // the encoded instruction.  So here change to I1 and I2 values via:
4500   // I1 = NOT(J1 EOR S);
4501   // I2 = NOT(J2 EOR S);
4502   // and build the imm32 with two trailing zeros as documented:
4503   // imm32 = SignExtend(S:I1:I2:imm10H:imm10L:'00', 32);
4504   unsigned S = (Val >> 23) & 1;
4505   unsigned J1 = (Val >> 22) & 1;
4506   unsigned J2 = (Val >> 21) & 1;
4507   unsigned I1 = !(J1 ^ S);
4508   unsigned I2 = !(J2 ^ S);
4509   unsigned tmp = (Val & ~0x600000) | (I1 << 22) | (I2 << 21);
4510   int imm32 = SignExtend32<25>(tmp << 1);
4511 
4512   if (!tryAddingSymbolicOperand(Address,
4513                                 (Address & ~2u) + imm32 + 4,
4514                                 true, 4, Inst, Decoder))
4515     Inst.addOperand(MCOperand::createImm(imm32));
4516   return MCDisassembler::Success;
4517 }
4518 
4519 static DecodeStatus DecodeCoprocessor(MCInst &Inst, unsigned Val,
4520                               uint64_t Address, const void *Decoder) {
4521   if (Val == 0xA || Val == 0xB)
4522     return MCDisassembler::Fail;
4523 
4524   const FeatureBitset &featureBits =
4525     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4526 
4527   if (!isValidCoprocessorNumber(Val, featureBits))
4528     return MCDisassembler::Fail;
4529 
4530   Inst.addOperand(MCOperand::createImm(Val));
4531   return MCDisassembler::Success;
4532 }
4533 
4534 static DecodeStatus
4535 DecodeThumbTableBranch(MCInst &Inst, unsigned Insn,
4536                        uint64_t Address, const void *Decoder) {
4537   const FeatureBitset &FeatureBits =
4538     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4539   DecodeStatus S = MCDisassembler::Success;
4540 
4541   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4542   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4543 
4544   if (Rn == 13 && !FeatureBits[ARM::HasV8Ops]) S = MCDisassembler::SoftFail;
4545   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4546     return MCDisassembler::Fail;
4547   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
4548     return MCDisassembler::Fail;
4549   return S;
4550 }
4551 
4552 static DecodeStatus
4553 DecodeThumb2BCCInstruction(MCInst &Inst, unsigned Insn,
4554                            uint64_t Address, const void *Decoder) {
4555   DecodeStatus S = MCDisassembler::Success;
4556 
4557   unsigned pred = fieldFromInstruction(Insn, 22, 4);
4558   if (pred == 0xE || pred == 0xF) {
4559     unsigned opc = fieldFromInstruction(Insn, 4, 28);
4560     switch (opc) {
4561       default:
4562         return MCDisassembler::Fail;
4563       case 0xf3bf8f4:
4564         Inst.setOpcode(ARM::t2DSB);
4565         break;
4566       case 0xf3bf8f5:
4567         Inst.setOpcode(ARM::t2DMB);
4568         break;
4569       case 0xf3bf8f6:
4570         Inst.setOpcode(ARM::t2ISB);
4571         break;
4572     }
4573 
4574     unsigned imm = fieldFromInstruction(Insn, 0, 4);
4575     return DecodeMemBarrierOption(Inst, imm, Address, Decoder);
4576   }
4577 
4578   unsigned brtarget = fieldFromInstruction(Insn, 0, 11) << 1;
4579   brtarget |= fieldFromInstruction(Insn, 11, 1) << 19;
4580   brtarget |= fieldFromInstruction(Insn, 13, 1) << 18;
4581   brtarget |= fieldFromInstruction(Insn, 16, 6) << 12;
4582   brtarget |= fieldFromInstruction(Insn, 26, 1) << 20;
4583 
4584   if (!Check(S, DecodeT2BROperand(Inst, brtarget, Address, Decoder)))
4585     return MCDisassembler::Fail;
4586   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4587     return MCDisassembler::Fail;
4588 
4589   return S;
4590 }
4591 
4592 // Decode a shifted immediate operand.  These basically consist
4593 // of an 8-bit value, and a 4-bit directive that specifies either
4594 // a splat operation or a rotation.
4595 static DecodeStatus DecodeT2SOImm(MCInst &Inst, unsigned Val,
4596                           uint64_t Address, const void *Decoder) {
4597   unsigned ctrl = fieldFromInstruction(Val, 10, 2);
4598   if (ctrl == 0) {
4599     unsigned byte = fieldFromInstruction(Val, 8, 2);
4600     unsigned imm = fieldFromInstruction(Val, 0, 8);
4601     switch (byte) {
4602       case 0:
4603         Inst.addOperand(MCOperand::createImm(imm));
4604         break;
4605       case 1:
4606         Inst.addOperand(MCOperand::createImm((imm << 16) | imm));
4607         break;
4608       case 2:
4609         Inst.addOperand(MCOperand::createImm((imm << 24) | (imm << 8)));
4610         break;
4611       case 3:
4612         Inst.addOperand(MCOperand::createImm((imm << 24) | (imm << 16) |
4613                                              (imm << 8)  |  imm));
4614         break;
4615     }
4616   } else {
4617     unsigned unrot = fieldFromInstruction(Val, 0, 7) | 0x80;
4618     unsigned rot = fieldFromInstruction(Val, 7, 5);
4619     unsigned imm = (unrot >> rot) | (unrot << ((32-rot)&31));
4620     Inst.addOperand(MCOperand::createImm(imm));
4621   }
4622 
4623   return MCDisassembler::Success;
4624 }
4625 
4626 static DecodeStatus
4627 DecodeThumbBCCTargetOperand(MCInst &Inst, unsigned Val,
4628                             uint64_t Address, const void *Decoder) {
4629   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<9>(Val<<1) + 4,
4630                                 true, 2, Inst, Decoder))
4631     Inst.addOperand(MCOperand::createImm(SignExtend32<9>(Val << 1)));
4632   return MCDisassembler::Success;
4633 }
4634 
4635 static DecodeStatus DecodeThumbBLTargetOperand(MCInst &Inst, unsigned Val,
4636                                                uint64_t Address,
4637                                                const void *Decoder) {
4638   // Val is passed in as S:J1:J2:imm10:imm11
4639   // Note no trailing zero after imm11.  Also the J1 and J2 values are from
4640   // the encoded instruction.  So here change to I1 and I2 values via:
4641   // I1 = NOT(J1 EOR S);
4642   // I2 = NOT(J2 EOR S);
4643   // and build the imm32 with one trailing zero as documented:
4644   // imm32 = SignExtend(S:I1:I2:imm10:imm11:'0', 32);
4645   unsigned S = (Val >> 23) & 1;
4646   unsigned J1 = (Val >> 22) & 1;
4647   unsigned J2 = (Val >> 21) & 1;
4648   unsigned I1 = !(J1 ^ S);
4649   unsigned I2 = !(J2 ^ S);
4650   unsigned tmp = (Val & ~0x600000) | (I1 << 22) | (I2 << 21);
4651   int imm32 = SignExtend32<25>(tmp << 1);
4652 
4653   if (!tryAddingSymbolicOperand(Address, Address + imm32 + 4,
4654                                 true, 4, Inst, Decoder))
4655     Inst.addOperand(MCOperand::createImm(imm32));
4656   return MCDisassembler::Success;
4657 }
4658 
4659 static DecodeStatus DecodeMemBarrierOption(MCInst &Inst, unsigned Val,
4660                                    uint64_t Address, const void *Decoder) {
4661   if (Val & ~0xf)
4662     return MCDisassembler::Fail;
4663 
4664   Inst.addOperand(MCOperand::createImm(Val));
4665   return MCDisassembler::Success;
4666 }
4667 
4668 static DecodeStatus DecodeInstSyncBarrierOption(MCInst &Inst, unsigned Val,
4669                                         uint64_t Address, const void *Decoder) {
4670   if (Val & ~0xf)
4671     return MCDisassembler::Fail;
4672 
4673   Inst.addOperand(MCOperand::createImm(Val));
4674   return MCDisassembler::Success;
4675 }
4676 
4677 static DecodeStatus DecodeMSRMask(MCInst &Inst, unsigned Val,
4678                           uint64_t Address, const void *Decoder) {
4679   DecodeStatus S = MCDisassembler::Success;
4680   const FeatureBitset &FeatureBits =
4681     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4682 
4683   if (FeatureBits[ARM::FeatureMClass]) {
4684     unsigned ValLow = Val & 0xff;
4685 
4686     // Validate the SYSm value first.
4687     switch (ValLow) {
4688     case  0: // apsr
4689     case  1: // iapsr
4690     case  2: // eapsr
4691     case  3: // xpsr
4692     case  5: // ipsr
4693     case  6: // epsr
4694     case  7: // iepsr
4695     case  8: // msp
4696     case  9: // psp
4697     case 16: // primask
4698     case 20: // control
4699       break;
4700     case 17: // basepri
4701     case 18: // basepri_max
4702     case 19: // faultmask
4703       if (!(FeatureBits[ARM::HasV7Ops]))
4704         // Values basepri, basepri_max and faultmask are only valid for v7m.
4705         return MCDisassembler::Fail;
4706       break;
4707     case 0x8a: // msplim_ns
4708     case 0x8b: // psplim_ns
4709     case 0x91: // basepri_ns
4710     case 0x93: // faultmask_ns
4711       if (!(FeatureBits[ARM::HasV8MMainlineOps]))
4712         return MCDisassembler::Fail;
4713       LLVM_FALLTHROUGH;
4714     case 10:   // msplim
4715     case 11:   // psplim
4716     case 0x88: // msp_ns
4717     case 0x89: // psp_ns
4718     case 0x90: // primask_ns
4719     case 0x94: // control_ns
4720     case 0x98: // sp_ns
4721       if (!(FeatureBits[ARM::Feature8MSecExt]))
4722         return MCDisassembler::Fail;
4723       break;
4724     default:
4725       // Architecturally defined as unpredictable
4726       S = MCDisassembler::SoftFail;
4727       break;
4728     }
4729 
4730     if (Inst.getOpcode() == ARM::t2MSR_M) {
4731       unsigned Mask = fieldFromInstruction(Val, 10, 2);
4732       if (!(FeatureBits[ARM::HasV7Ops])) {
4733         // The ARMv6-M MSR bits {11-10} can be only 0b10, other values are
4734         // unpredictable.
4735         if (Mask != 2)
4736           S = MCDisassembler::SoftFail;
4737       }
4738       else {
4739         // The ARMv7-M architecture stores an additional 2-bit mask value in
4740         // MSR bits {11-10}. The mask is used only with apsr, iapsr, eapsr and
4741         // xpsr, it has to be 0b10 in other cases. Bit mask{1} indicates if
4742         // the NZCVQ bits should be moved by the instruction. Bit mask{0}
4743         // indicates the move for the GE{3:0} bits, the mask{0} bit can be set
4744         // only if the processor includes the DSP extension.
4745         if (Mask == 0 || (Mask != 2 && ValLow > 3) ||
4746             (!(FeatureBits[ARM::FeatureDSP]) && (Mask & 1)))
4747           S = MCDisassembler::SoftFail;
4748       }
4749     }
4750   } else {
4751     // A/R class
4752     if (Val == 0)
4753       return MCDisassembler::Fail;
4754   }
4755   Inst.addOperand(MCOperand::createImm(Val));
4756   return S;
4757 }
4758 
4759 static DecodeStatus DecodeBankedReg(MCInst &Inst, unsigned Val,
4760                                     uint64_t Address, const void *Decoder) {
4761   unsigned R = fieldFromInstruction(Val, 5, 1);
4762   unsigned SysM = fieldFromInstruction(Val, 0, 5);
4763 
4764   // The table of encodings for these banked registers comes from B9.2.3 of the
4765   // ARM ARM. There are patterns, but nothing regular enough to make this logic
4766   // neater. So by fiat, these values are UNPREDICTABLE:
4767   if (!ARMBankedReg::lookupBankedRegByEncoding((R << 5) | SysM))
4768     return MCDisassembler::Fail;
4769 
4770   Inst.addOperand(MCOperand::createImm(Val));
4771   return MCDisassembler::Success;
4772 }
4773 
4774 static DecodeStatus DecodeDoubleRegLoad(MCInst &Inst, unsigned Insn,
4775                                         uint64_t Address, const void *Decoder) {
4776   DecodeStatus S = MCDisassembler::Success;
4777 
4778   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4779   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4780   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4781 
4782   if (Rn == 0xF)
4783     S = MCDisassembler::SoftFail;
4784 
4785   if (!Check(S, DecodeGPRPairRegisterClass(Inst, Rt, Address, Decoder)))
4786     return MCDisassembler::Fail;
4787   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4788     return MCDisassembler::Fail;
4789   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4790     return MCDisassembler::Fail;
4791 
4792   return S;
4793 }
4794 
4795 static DecodeStatus DecodeDoubleRegStore(MCInst &Inst, unsigned Insn,
4796                                          uint64_t Address,
4797                                          const void *Decoder) {
4798   DecodeStatus S = MCDisassembler::Success;
4799 
4800   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4801   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
4802   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4803   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4804 
4805   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
4806     return MCDisassembler::Fail;
4807 
4808   if (Rn == 0xF || Rd == Rn || Rd == Rt || Rd == Rt+1)
4809     S = MCDisassembler::SoftFail;
4810 
4811   if (!Check(S, DecodeGPRPairRegisterClass(Inst, Rt, Address, Decoder)))
4812     return MCDisassembler::Fail;
4813   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4814     return MCDisassembler::Fail;
4815   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4816     return MCDisassembler::Fail;
4817 
4818   return S;
4819 }
4820 
4821 static DecodeStatus DecodeLDRPreImm(MCInst &Inst, unsigned Insn,
4822                             uint64_t Address, const void *Decoder) {
4823   DecodeStatus S = MCDisassembler::Success;
4824 
4825   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4826   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4827   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4828   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4829   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4830   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4831 
4832   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4833 
4834   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4835     return MCDisassembler::Fail;
4836   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4837     return MCDisassembler::Fail;
4838   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
4839     return MCDisassembler::Fail;
4840   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4841     return MCDisassembler::Fail;
4842 
4843   return S;
4844 }
4845 
4846 static DecodeStatus DecodeLDRPreReg(MCInst &Inst, unsigned Insn,
4847                             uint64_t Address, const void *Decoder) {
4848   DecodeStatus S = MCDisassembler::Success;
4849 
4850   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4851   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4852   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4853   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4854   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4855   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4856   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4857 
4858   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4859   if (Rm == 0xF) S = MCDisassembler::SoftFail;
4860 
4861   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4862     return MCDisassembler::Fail;
4863   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4864     return MCDisassembler::Fail;
4865   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
4866     return MCDisassembler::Fail;
4867   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4868     return MCDisassembler::Fail;
4869 
4870   return S;
4871 }
4872 
4873 static DecodeStatus DecodeSTRPreImm(MCInst &Inst, unsigned Insn,
4874                             uint64_t Address, const void *Decoder) {
4875   DecodeStatus S = MCDisassembler::Success;
4876 
4877   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4878   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4879   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4880   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4881   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4882   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4883 
4884   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4885 
4886   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4887     return MCDisassembler::Fail;
4888   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4889     return MCDisassembler::Fail;
4890   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
4891     return MCDisassembler::Fail;
4892   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4893     return MCDisassembler::Fail;
4894 
4895   return S;
4896 }
4897 
4898 static DecodeStatus DecodeSTRPreReg(MCInst &Inst, unsigned Insn,
4899                             uint64_t Address, const void *Decoder) {
4900   DecodeStatus S = MCDisassembler::Success;
4901 
4902   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4903   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4904   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4905   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4906   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4907   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4908 
4909   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4910 
4911   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4912     return MCDisassembler::Fail;
4913   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4914     return MCDisassembler::Fail;
4915   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
4916     return MCDisassembler::Fail;
4917   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4918     return MCDisassembler::Fail;
4919 
4920   return S;
4921 }
4922 
4923 static DecodeStatus DecodeVLD1LN(MCInst &Inst, unsigned Insn,
4924                          uint64_t Address, const void *Decoder) {
4925   DecodeStatus S = MCDisassembler::Success;
4926 
4927   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4928   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4929   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4930   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4931   unsigned size = fieldFromInstruction(Insn, 10, 2);
4932 
4933   unsigned align = 0;
4934   unsigned index = 0;
4935   switch (size) {
4936     default:
4937       return MCDisassembler::Fail;
4938     case 0:
4939       if (fieldFromInstruction(Insn, 4, 1))
4940         return MCDisassembler::Fail; // UNDEFINED
4941       index = fieldFromInstruction(Insn, 5, 3);
4942       break;
4943     case 1:
4944       if (fieldFromInstruction(Insn, 5, 1))
4945         return MCDisassembler::Fail; // UNDEFINED
4946       index = fieldFromInstruction(Insn, 6, 2);
4947       if (fieldFromInstruction(Insn, 4, 1))
4948         align = 2;
4949       break;
4950     case 2:
4951       if (fieldFromInstruction(Insn, 6, 1))
4952         return MCDisassembler::Fail; // UNDEFINED
4953       index = fieldFromInstruction(Insn, 7, 1);
4954 
4955       switch (fieldFromInstruction(Insn, 4, 2)) {
4956         case 0 :
4957           align = 0; break;
4958         case 3:
4959           align = 4; break;
4960         default:
4961           return MCDisassembler::Fail;
4962       }
4963       break;
4964   }
4965 
4966   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4967     return MCDisassembler::Fail;
4968   if (Rm != 0xF) { // Writeback
4969     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4970       return MCDisassembler::Fail;
4971   }
4972   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4973     return MCDisassembler::Fail;
4974   Inst.addOperand(MCOperand::createImm(align));
4975   if (Rm != 0xF) {
4976     if (Rm != 0xD) {
4977       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4978         return MCDisassembler::Fail;
4979     } else
4980       Inst.addOperand(MCOperand::createReg(0));
4981   }
4982 
4983   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4984     return MCDisassembler::Fail;
4985   Inst.addOperand(MCOperand::createImm(index));
4986 
4987   return S;
4988 }
4989 
4990 static DecodeStatus DecodeVST1LN(MCInst &Inst, unsigned Insn,
4991                          uint64_t Address, const void *Decoder) {
4992   DecodeStatus S = MCDisassembler::Success;
4993 
4994   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4995   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4996   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4997   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4998   unsigned size = fieldFromInstruction(Insn, 10, 2);
4999 
5000   unsigned align = 0;
5001   unsigned index = 0;
5002   switch (size) {
5003     default:
5004       return MCDisassembler::Fail;
5005     case 0:
5006       if (fieldFromInstruction(Insn, 4, 1))
5007         return MCDisassembler::Fail; // UNDEFINED
5008       index = fieldFromInstruction(Insn, 5, 3);
5009       break;
5010     case 1:
5011       if (fieldFromInstruction(Insn, 5, 1))
5012         return MCDisassembler::Fail; // UNDEFINED
5013       index = fieldFromInstruction(Insn, 6, 2);
5014       if (fieldFromInstruction(Insn, 4, 1))
5015         align = 2;
5016       break;
5017     case 2:
5018       if (fieldFromInstruction(Insn, 6, 1))
5019         return MCDisassembler::Fail; // UNDEFINED
5020       index = fieldFromInstruction(Insn, 7, 1);
5021 
5022       switch (fieldFromInstruction(Insn, 4, 2)) {
5023         case 0:
5024           align = 0; break;
5025         case 3:
5026           align = 4; break;
5027         default:
5028           return MCDisassembler::Fail;
5029       }
5030       break;
5031   }
5032 
5033   if (Rm != 0xF) { // Writeback
5034     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5035     return MCDisassembler::Fail;
5036   }
5037   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5038     return MCDisassembler::Fail;
5039   Inst.addOperand(MCOperand::createImm(align));
5040   if (Rm != 0xF) {
5041     if (Rm != 0xD) {
5042       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5043     return MCDisassembler::Fail;
5044     } else
5045       Inst.addOperand(MCOperand::createReg(0));
5046   }
5047 
5048   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5049     return MCDisassembler::Fail;
5050   Inst.addOperand(MCOperand::createImm(index));
5051 
5052   return S;
5053 }
5054 
5055 static DecodeStatus DecodeVLD2LN(MCInst &Inst, unsigned Insn,
5056                          uint64_t Address, const void *Decoder) {
5057   DecodeStatus S = MCDisassembler::Success;
5058 
5059   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5060   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5061   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5062   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5063   unsigned size = fieldFromInstruction(Insn, 10, 2);
5064 
5065   unsigned align = 0;
5066   unsigned index = 0;
5067   unsigned inc = 1;
5068   switch (size) {
5069     default:
5070       return MCDisassembler::Fail;
5071     case 0:
5072       index = fieldFromInstruction(Insn, 5, 3);
5073       if (fieldFromInstruction(Insn, 4, 1))
5074         align = 2;
5075       break;
5076     case 1:
5077       index = fieldFromInstruction(Insn, 6, 2);
5078       if (fieldFromInstruction(Insn, 4, 1))
5079         align = 4;
5080       if (fieldFromInstruction(Insn, 5, 1))
5081         inc = 2;
5082       break;
5083     case 2:
5084       if (fieldFromInstruction(Insn, 5, 1))
5085         return MCDisassembler::Fail; // UNDEFINED
5086       index = fieldFromInstruction(Insn, 7, 1);
5087       if (fieldFromInstruction(Insn, 4, 1) != 0)
5088         align = 8;
5089       if (fieldFromInstruction(Insn, 6, 1))
5090         inc = 2;
5091       break;
5092   }
5093 
5094   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5095     return MCDisassembler::Fail;
5096   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5097     return MCDisassembler::Fail;
5098   if (Rm != 0xF) { // Writeback
5099     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5100       return MCDisassembler::Fail;
5101   }
5102   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5103     return MCDisassembler::Fail;
5104   Inst.addOperand(MCOperand::createImm(align));
5105   if (Rm != 0xF) {
5106     if (Rm != 0xD) {
5107       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5108         return MCDisassembler::Fail;
5109     } else
5110       Inst.addOperand(MCOperand::createReg(0));
5111   }
5112 
5113   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5114     return MCDisassembler::Fail;
5115   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5116     return MCDisassembler::Fail;
5117   Inst.addOperand(MCOperand::createImm(index));
5118 
5119   return S;
5120 }
5121 
5122 static DecodeStatus DecodeVST2LN(MCInst &Inst, unsigned Insn,
5123                          uint64_t Address, const void *Decoder) {
5124   DecodeStatus S = MCDisassembler::Success;
5125 
5126   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5127   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5128   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5129   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5130   unsigned size = fieldFromInstruction(Insn, 10, 2);
5131 
5132   unsigned align = 0;
5133   unsigned index = 0;
5134   unsigned inc = 1;
5135   switch (size) {
5136     default:
5137       return MCDisassembler::Fail;
5138     case 0:
5139       index = fieldFromInstruction(Insn, 5, 3);
5140       if (fieldFromInstruction(Insn, 4, 1))
5141         align = 2;
5142       break;
5143     case 1:
5144       index = fieldFromInstruction(Insn, 6, 2);
5145       if (fieldFromInstruction(Insn, 4, 1))
5146         align = 4;
5147       if (fieldFromInstruction(Insn, 5, 1))
5148         inc = 2;
5149       break;
5150     case 2:
5151       if (fieldFromInstruction(Insn, 5, 1))
5152         return MCDisassembler::Fail; // UNDEFINED
5153       index = fieldFromInstruction(Insn, 7, 1);
5154       if (fieldFromInstruction(Insn, 4, 1) != 0)
5155         align = 8;
5156       if (fieldFromInstruction(Insn, 6, 1))
5157         inc = 2;
5158       break;
5159   }
5160 
5161   if (Rm != 0xF) { // Writeback
5162     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5163       return MCDisassembler::Fail;
5164   }
5165   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5166     return MCDisassembler::Fail;
5167   Inst.addOperand(MCOperand::createImm(align));
5168   if (Rm != 0xF) {
5169     if (Rm != 0xD) {
5170       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5171         return MCDisassembler::Fail;
5172     } else
5173       Inst.addOperand(MCOperand::createReg(0));
5174   }
5175 
5176   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5177     return MCDisassembler::Fail;
5178   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5179     return MCDisassembler::Fail;
5180   Inst.addOperand(MCOperand::createImm(index));
5181 
5182   return S;
5183 }
5184 
5185 static DecodeStatus DecodeVLD3LN(MCInst &Inst, unsigned Insn,
5186                          uint64_t Address, const void *Decoder) {
5187   DecodeStatus S = MCDisassembler::Success;
5188 
5189   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5190   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5191   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5192   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5193   unsigned size = fieldFromInstruction(Insn, 10, 2);
5194 
5195   unsigned align = 0;
5196   unsigned index = 0;
5197   unsigned inc = 1;
5198   switch (size) {
5199     default:
5200       return MCDisassembler::Fail;
5201     case 0:
5202       if (fieldFromInstruction(Insn, 4, 1))
5203         return MCDisassembler::Fail; // UNDEFINED
5204       index = fieldFromInstruction(Insn, 5, 3);
5205       break;
5206     case 1:
5207       if (fieldFromInstruction(Insn, 4, 1))
5208         return MCDisassembler::Fail; // UNDEFINED
5209       index = fieldFromInstruction(Insn, 6, 2);
5210       if (fieldFromInstruction(Insn, 5, 1))
5211         inc = 2;
5212       break;
5213     case 2:
5214       if (fieldFromInstruction(Insn, 4, 2))
5215         return MCDisassembler::Fail; // UNDEFINED
5216       index = fieldFromInstruction(Insn, 7, 1);
5217       if (fieldFromInstruction(Insn, 6, 1))
5218         inc = 2;
5219       break;
5220   }
5221 
5222   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5223     return MCDisassembler::Fail;
5224   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5225     return MCDisassembler::Fail;
5226   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5227     return MCDisassembler::Fail;
5228 
5229   if (Rm != 0xF) { // Writeback
5230     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5231     return MCDisassembler::Fail;
5232   }
5233   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5234     return MCDisassembler::Fail;
5235   Inst.addOperand(MCOperand::createImm(align));
5236   if (Rm != 0xF) {
5237     if (Rm != 0xD) {
5238       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5239     return MCDisassembler::Fail;
5240     } else
5241       Inst.addOperand(MCOperand::createReg(0));
5242   }
5243 
5244   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5245     return MCDisassembler::Fail;
5246   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5247     return MCDisassembler::Fail;
5248   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5249     return MCDisassembler::Fail;
5250   Inst.addOperand(MCOperand::createImm(index));
5251 
5252   return S;
5253 }
5254 
5255 static DecodeStatus DecodeVST3LN(MCInst &Inst, unsigned Insn,
5256                          uint64_t Address, const void *Decoder) {
5257   DecodeStatus S = MCDisassembler::Success;
5258 
5259   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5260   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5261   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5262   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5263   unsigned size = fieldFromInstruction(Insn, 10, 2);
5264 
5265   unsigned align = 0;
5266   unsigned index = 0;
5267   unsigned inc = 1;
5268   switch (size) {
5269     default:
5270       return MCDisassembler::Fail;
5271     case 0:
5272       if (fieldFromInstruction(Insn, 4, 1))
5273         return MCDisassembler::Fail; // UNDEFINED
5274       index = fieldFromInstruction(Insn, 5, 3);
5275       break;
5276     case 1:
5277       if (fieldFromInstruction(Insn, 4, 1))
5278         return MCDisassembler::Fail; // UNDEFINED
5279       index = fieldFromInstruction(Insn, 6, 2);
5280       if (fieldFromInstruction(Insn, 5, 1))
5281         inc = 2;
5282       break;
5283     case 2:
5284       if (fieldFromInstruction(Insn, 4, 2))
5285         return MCDisassembler::Fail; // UNDEFINED
5286       index = fieldFromInstruction(Insn, 7, 1);
5287       if (fieldFromInstruction(Insn, 6, 1))
5288         inc = 2;
5289       break;
5290   }
5291 
5292   if (Rm != 0xF) { // Writeback
5293     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5294     return MCDisassembler::Fail;
5295   }
5296   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5297     return MCDisassembler::Fail;
5298   Inst.addOperand(MCOperand::createImm(align));
5299   if (Rm != 0xF) {
5300     if (Rm != 0xD) {
5301       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5302     return MCDisassembler::Fail;
5303     } else
5304       Inst.addOperand(MCOperand::createReg(0));
5305   }
5306 
5307   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5308     return MCDisassembler::Fail;
5309   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5310     return MCDisassembler::Fail;
5311   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5312     return MCDisassembler::Fail;
5313   Inst.addOperand(MCOperand::createImm(index));
5314 
5315   return S;
5316 }
5317 
5318 static DecodeStatus DecodeVLD4LN(MCInst &Inst, unsigned Insn,
5319                          uint64_t Address, const void *Decoder) {
5320   DecodeStatus S = MCDisassembler::Success;
5321 
5322   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5323   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5324   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5325   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5326   unsigned size = fieldFromInstruction(Insn, 10, 2);
5327 
5328   unsigned align = 0;
5329   unsigned index = 0;
5330   unsigned inc = 1;
5331   switch (size) {
5332     default:
5333       return MCDisassembler::Fail;
5334     case 0:
5335       if (fieldFromInstruction(Insn, 4, 1))
5336         align = 4;
5337       index = fieldFromInstruction(Insn, 5, 3);
5338       break;
5339     case 1:
5340       if (fieldFromInstruction(Insn, 4, 1))
5341         align = 8;
5342       index = fieldFromInstruction(Insn, 6, 2);
5343       if (fieldFromInstruction(Insn, 5, 1))
5344         inc = 2;
5345       break;
5346     case 2:
5347       switch (fieldFromInstruction(Insn, 4, 2)) {
5348         case 0:
5349           align = 0; break;
5350         case 3:
5351           return MCDisassembler::Fail;
5352         default:
5353           align = 4 << fieldFromInstruction(Insn, 4, 2); break;
5354       }
5355 
5356       index = fieldFromInstruction(Insn, 7, 1);
5357       if (fieldFromInstruction(Insn, 6, 1))
5358         inc = 2;
5359       break;
5360   }
5361 
5362   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5363     return MCDisassembler::Fail;
5364   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5365     return MCDisassembler::Fail;
5366   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5367     return MCDisassembler::Fail;
5368   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5369     return MCDisassembler::Fail;
5370 
5371   if (Rm != 0xF) { // Writeback
5372     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5373       return MCDisassembler::Fail;
5374   }
5375   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5376     return MCDisassembler::Fail;
5377   Inst.addOperand(MCOperand::createImm(align));
5378   if (Rm != 0xF) {
5379     if (Rm != 0xD) {
5380       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5381         return MCDisassembler::Fail;
5382     } else
5383       Inst.addOperand(MCOperand::createReg(0));
5384   }
5385 
5386   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5387     return MCDisassembler::Fail;
5388   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5389     return MCDisassembler::Fail;
5390   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5391     return MCDisassembler::Fail;
5392   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5393     return MCDisassembler::Fail;
5394   Inst.addOperand(MCOperand::createImm(index));
5395 
5396   return S;
5397 }
5398 
5399 static DecodeStatus DecodeVST4LN(MCInst &Inst, unsigned Insn,
5400                          uint64_t Address, const void *Decoder) {
5401   DecodeStatus S = MCDisassembler::Success;
5402 
5403   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5404   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5405   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5406   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5407   unsigned size = fieldFromInstruction(Insn, 10, 2);
5408 
5409   unsigned align = 0;
5410   unsigned index = 0;
5411   unsigned inc = 1;
5412   switch (size) {
5413     default:
5414       return MCDisassembler::Fail;
5415     case 0:
5416       if (fieldFromInstruction(Insn, 4, 1))
5417         align = 4;
5418       index = fieldFromInstruction(Insn, 5, 3);
5419       break;
5420     case 1:
5421       if (fieldFromInstruction(Insn, 4, 1))
5422         align = 8;
5423       index = fieldFromInstruction(Insn, 6, 2);
5424       if (fieldFromInstruction(Insn, 5, 1))
5425         inc = 2;
5426       break;
5427     case 2:
5428       switch (fieldFromInstruction(Insn, 4, 2)) {
5429         case 0:
5430           align = 0; break;
5431         case 3:
5432           return MCDisassembler::Fail;
5433         default:
5434           align = 4 << fieldFromInstruction(Insn, 4, 2); break;
5435       }
5436 
5437       index = fieldFromInstruction(Insn, 7, 1);
5438       if (fieldFromInstruction(Insn, 6, 1))
5439         inc = 2;
5440       break;
5441   }
5442 
5443   if (Rm != 0xF) { // Writeback
5444     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5445     return MCDisassembler::Fail;
5446   }
5447   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5448     return MCDisassembler::Fail;
5449   Inst.addOperand(MCOperand::createImm(align));
5450   if (Rm != 0xF) {
5451     if (Rm != 0xD) {
5452       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5453     return MCDisassembler::Fail;
5454     } else
5455       Inst.addOperand(MCOperand::createReg(0));
5456   }
5457 
5458   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5459     return MCDisassembler::Fail;
5460   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5461     return MCDisassembler::Fail;
5462   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5463     return MCDisassembler::Fail;
5464   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5465     return MCDisassembler::Fail;
5466   Inst.addOperand(MCOperand::createImm(index));
5467 
5468   return S;
5469 }
5470 
5471 static DecodeStatus DecodeVMOVSRR(MCInst &Inst, unsigned Insn,
5472                                   uint64_t Address, const void *Decoder) {
5473   DecodeStatus S = MCDisassembler::Success;
5474   unsigned Rt  = fieldFromInstruction(Insn, 12, 4);
5475   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
5476   unsigned Rm  = fieldFromInstruction(Insn,  5, 1);
5477   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5478   Rm |= fieldFromInstruction(Insn, 0, 4) << 1;
5479 
5480   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
5481     S = MCDisassembler::SoftFail;
5482 
5483   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
5484     return MCDisassembler::Fail;
5485   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
5486     return MCDisassembler::Fail;
5487   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
5488     return MCDisassembler::Fail;
5489   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
5490     return MCDisassembler::Fail;
5491   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5492     return MCDisassembler::Fail;
5493 
5494   return S;
5495 }
5496 
5497 static DecodeStatus DecodeVMOVRRS(MCInst &Inst, unsigned Insn,
5498                                   uint64_t Address, const void *Decoder) {
5499   DecodeStatus S = MCDisassembler::Success;
5500   unsigned Rt  = fieldFromInstruction(Insn, 12, 4);
5501   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
5502   unsigned Rm  = fieldFromInstruction(Insn,  5, 1);
5503   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5504   Rm |= fieldFromInstruction(Insn, 0, 4) << 1;
5505 
5506   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
5507     S = MCDisassembler::SoftFail;
5508 
5509   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
5510     return MCDisassembler::Fail;
5511   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
5512     return MCDisassembler::Fail;
5513   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
5514     return MCDisassembler::Fail;
5515   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
5516     return MCDisassembler::Fail;
5517   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5518     return MCDisassembler::Fail;
5519 
5520   return S;
5521 }
5522 
5523 static DecodeStatus DecodeIT(MCInst &Inst, unsigned Insn,
5524                              uint64_t Address, const void *Decoder) {
5525   DecodeStatus S = MCDisassembler::Success;
5526   unsigned pred = fieldFromInstruction(Insn, 4, 4);
5527   unsigned mask = fieldFromInstruction(Insn, 0, 4);
5528 
5529   if (pred == 0xF) {
5530     pred = 0xE;
5531     S = MCDisassembler::SoftFail;
5532   }
5533 
5534   if (mask == 0x0)
5535     return MCDisassembler::Fail;
5536 
5537   // IT masks are encoded as a sequence of replacement low-order bits
5538   // for the condition code. So if the low bit of the starting
5539   // condition code is 1, then we have to flip all the bits above the
5540   // terminating bit (which is the lowest 1 bit).
5541   if (pred & 1) {
5542     unsigned LowBit = mask & -mask;
5543     unsigned BitsAboveLowBit = 0xF & (-LowBit << 1);
5544     mask ^= BitsAboveLowBit;
5545   }
5546 
5547   Inst.addOperand(MCOperand::createImm(pred));
5548   Inst.addOperand(MCOperand::createImm(mask));
5549   return S;
5550 }
5551 
5552 static DecodeStatus
5553 DecodeT2LDRDPreInstruction(MCInst &Inst, unsigned Insn,
5554                            uint64_t Address, const void *Decoder) {
5555   DecodeStatus S = MCDisassembler::Success;
5556 
5557   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5558   unsigned Rt2 = fieldFromInstruction(Insn, 8, 4);
5559   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5560   unsigned addr = fieldFromInstruction(Insn, 0, 8);
5561   unsigned W = fieldFromInstruction(Insn, 21, 1);
5562   unsigned U = fieldFromInstruction(Insn, 23, 1);
5563   unsigned P = fieldFromInstruction(Insn, 24, 1);
5564   bool writeback = (W == 1) | (P == 0);
5565 
5566   addr |= (U << 8) | (Rn << 9);
5567 
5568   if (writeback && (Rn == Rt || Rn == Rt2))
5569     Check(S, MCDisassembler::SoftFail);
5570   if (Rt == Rt2)
5571     Check(S, MCDisassembler::SoftFail);
5572 
5573   // Rt
5574   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
5575     return MCDisassembler::Fail;
5576   // Rt2
5577   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
5578     return MCDisassembler::Fail;
5579   // Writeback operand
5580   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
5581     return MCDisassembler::Fail;
5582   // addr
5583   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
5584     return MCDisassembler::Fail;
5585 
5586   return S;
5587 }
5588 
5589 static DecodeStatus
5590 DecodeT2STRDPreInstruction(MCInst &Inst, unsigned Insn,
5591                            uint64_t Address, const void *Decoder) {
5592   DecodeStatus S = MCDisassembler::Success;
5593 
5594   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5595   unsigned Rt2 = fieldFromInstruction(Insn, 8, 4);
5596   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5597   unsigned addr = fieldFromInstruction(Insn, 0, 8);
5598   unsigned W = fieldFromInstruction(Insn, 21, 1);
5599   unsigned U = fieldFromInstruction(Insn, 23, 1);
5600   unsigned P = fieldFromInstruction(Insn, 24, 1);
5601   bool writeback = (W == 1) | (P == 0);
5602 
5603   addr |= (U << 8) | (Rn << 9);
5604 
5605   if (writeback && (Rn == Rt || Rn == Rt2))
5606     Check(S, MCDisassembler::SoftFail);
5607 
5608   // Writeback operand
5609   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
5610     return MCDisassembler::Fail;
5611   // Rt
5612   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
5613     return MCDisassembler::Fail;
5614   // Rt2
5615   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
5616     return MCDisassembler::Fail;
5617   // addr
5618   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
5619     return MCDisassembler::Fail;
5620 
5621   return S;
5622 }
5623 
5624 static DecodeStatus DecodeT2Adr(MCInst &Inst, uint32_t Insn,
5625                                 uint64_t Address, const void *Decoder) {
5626   unsigned sign1 = fieldFromInstruction(Insn, 21, 1);
5627   unsigned sign2 = fieldFromInstruction(Insn, 23, 1);
5628   if (sign1 != sign2) return MCDisassembler::Fail;
5629   const unsigned Rd = fieldFromInstruction(Insn, 8, 4);
5630   assert(Inst.getNumOperands() == 0 && "We should receive an empty Inst");
5631   DecodeStatus S = DecoderGPRRegisterClass(Inst, Rd, Address, Decoder);
5632 
5633   unsigned Val = fieldFromInstruction(Insn, 0, 8);
5634   Val |= fieldFromInstruction(Insn, 12, 3) << 8;
5635   Val |= fieldFromInstruction(Insn, 26, 1) << 11;
5636   // If sign, then it is decreasing the address.
5637   if (sign1) {
5638     // Following ARMv7 Architecture Manual, when the offset
5639     // is zero, it is decoded as a subw, not as a adr.w
5640     if (!Val) {
5641       Inst.setOpcode(ARM::t2SUBri12);
5642       Inst.addOperand(MCOperand::createReg(ARM::PC));
5643     } else
5644       Val = -Val;
5645   }
5646   Inst.addOperand(MCOperand::createImm(Val));
5647   return S;
5648 }
5649 
5650 static DecodeStatus DecodeT2ShifterImmOperand(MCInst &Inst, uint32_t Val,
5651                                               uint64_t Address,
5652                                               const void *Decoder) {
5653   DecodeStatus S = MCDisassembler::Success;
5654 
5655   // Shift of "asr #32" is not allowed in Thumb2 mode.
5656   if (Val == 0x20) S = MCDisassembler::Fail;
5657   Inst.addOperand(MCOperand::createImm(Val));
5658   return S;
5659 }
5660 
5661 static DecodeStatus DecodeSwap(MCInst &Inst, unsigned Insn,
5662                                uint64_t Address, const void *Decoder) {
5663   unsigned Rt   = fieldFromInstruction(Insn, 12, 4);
5664   unsigned Rt2  = fieldFromInstruction(Insn, 0,  4);
5665   unsigned Rn   = fieldFromInstruction(Insn, 16, 4);
5666   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5667 
5668   if (pred == 0xF)
5669     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
5670 
5671   DecodeStatus S = MCDisassembler::Success;
5672 
5673   if (Rt == Rn || Rn == Rt2)
5674     S = MCDisassembler::SoftFail;
5675 
5676   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5677     return MCDisassembler::Fail;
5678   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5679     return MCDisassembler::Fail;
5680   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
5681     return MCDisassembler::Fail;
5682   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5683     return MCDisassembler::Fail;
5684 
5685   return S;
5686 }
5687 
5688 static DecodeStatus DecodeVCVTD(MCInst &Inst, unsigned Insn,
5689                                 uint64_t Address, const void *Decoder) {
5690   const FeatureBitset &featureBits =
5691       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5692   bool hasFullFP16 = featureBits[ARM::FeatureFullFP16];
5693 
5694   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5695   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5696   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5697   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5698   unsigned imm = fieldFromInstruction(Insn, 16, 6);
5699   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
5700   unsigned op = fieldFromInstruction(Insn, 5, 1);
5701 
5702   DecodeStatus S = MCDisassembler::Success;
5703 
5704   // If the top 3 bits of imm are clear, this is a VMOV (immediate)
5705   if (!(imm & 0x38)) {
5706     if (cmode == 0xF) {
5707       if (op == 1) return MCDisassembler::Fail;
5708       Inst.setOpcode(ARM::VMOVv2f32);
5709     }
5710     if (hasFullFP16) {
5711       if (cmode == 0xE) {
5712         if (op == 1) {
5713           Inst.setOpcode(ARM::VMOVv1i64);
5714         } else {
5715           Inst.setOpcode(ARM::VMOVv8i8);
5716         }
5717       }
5718       if (cmode == 0xD) {
5719         if (op == 1) {
5720           Inst.setOpcode(ARM::VMVNv2i32);
5721         } else {
5722           Inst.setOpcode(ARM::VMOVv2i32);
5723         }
5724       }
5725       if (cmode == 0xC) {
5726         if (op == 1) {
5727           Inst.setOpcode(ARM::VMVNv2i32);
5728         } else {
5729           Inst.setOpcode(ARM::VMOVv2i32);
5730         }
5731       }
5732     }
5733     return DecodeVMOVModImmInstruction(Inst, Insn, Address, Decoder);
5734   }
5735 
5736   if (!(imm & 0x20)) return MCDisassembler::Fail;
5737 
5738   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
5739     return MCDisassembler::Fail;
5740   if (!Check(S, DecodeDPRRegisterClass(Inst, Vm, Address, Decoder)))
5741     return MCDisassembler::Fail;
5742   Inst.addOperand(MCOperand::createImm(64 - imm));
5743 
5744   return S;
5745 }
5746 
5747 static DecodeStatus DecodeVCVTQ(MCInst &Inst, unsigned Insn,
5748                                 uint64_t Address, const void *Decoder) {
5749   const FeatureBitset &featureBits =
5750       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5751   bool hasFullFP16 = featureBits[ARM::FeatureFullFP16];
5752 
5753   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5754   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5755   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5756   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5757   unsigned imm = fieldFromInstruction(Insn, 16, 6);
5758   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
5759   unsigned op = fieldFromInstruction(Insn, 5, 1);
5760 
5761   DecodeStatus S = MCDisassembler::Success;
5762 
5763   // If the top 3 bits of imm are clear, this is a VMOV (immediate)
5764   if (!(imm & 0x38)) {
5765     if (cmode == 0xF) {
5766       if (op == 1) return MCDisassembler::Fail;
5767       Inst.setOpcode(ARM::VMOVv4f32);
5768     }
5769     if (hasFullFP16) {
5770       if (cmode == 0xE) {
5771         if (op == 1) {
5772           Inst.setOpcode(ARM::VMOVv2i64);
5773         } else {
5774           Inst.setOpcode(ARM::VMOVv16i8);
5775         }
5776       }
5777       if (cmode == 0xD) {
5778         if (op == 1) {
5779           Inst.setOpcode(ARM::VMVNv4i32);
5780         } else {
5781           Inst.setOpcode(ARM::VMOVv4i32);
5782         }
5783       }
5784       if (cmode == 0xC) {
5785         if (op == 1) {
5786           Inst.setOpcode(ARM::VMVNv4i32);
5787         } else {
5788           Inst.setOpcode(ARM::VMOVv4i32);
5789         }
5790       }
5791     }
5792     return DecodeVMOVModImmInstruction(Inst, Insn, Address, Decoder);
5793   }
5794 
5795   if (!(imm & 0x20)) return MCDisassembler::Fail;
5796 
5797   if (!Check(S, DecodeQPRRegisterClass(Inst, Vd, Address, Decoder)))
5798     return MCDisassembler::Fail;
5799   if (!Check(S, DecodeQPRRegisterClass(Inst, Vm, Address, Decoder)))
5800     return MCDisassembler::Fail;
5801   Inst.addOperand(MCOperand::createImm(64 - imm));
5802 
5803   return S;
5804 }
5805 
5806 static DecodeStatus DecodeNEONComplexLane64Instruction(MCInst &Inst,
5807                                                        unsigned Insn,
5808                                                        uint64_t Address,
5809                                                        const void *Decoder) {
5810   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5811   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5812   unsigned Vn = (fieldFromInstruction(Insn, 16, 4) << 0);
5813   Vn |= (fieldFromInstruction(Insn, 7, 1) << 4);
5814   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5815   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5816   unsigned q = (fieldFromInstruction(Insn, 6, 1) << 0);
5817   unsigned rotate = (fieldFromInstruction(Insn, 20, 2) << 0);
5818 
5819   DecodeStatus S = MCDisassembler::Success;
5820 
5821   auto DestRegDecoder = q ? DecodeQPRRegisterClass : DecodeDPRRegisterClass;
5822 
5823   if (!Check(S, DestRegDecoder(Inst, Vd, Address, Decoder)))
5824     return MCDisassembler::Fail;
5825   if (!Check(S, DestRegDecoder(Inst, Vd, Address, Decoder)))
5826     return MCDisassembler::Fail;
5827   if (!Check(S, DestRegDecoder(Inst, Vn, Address, Decoder)))
5828     return MCDisassembler::Fail;
5829   if (!Check(S, DecodeDPRRegisterClass(Inst, Vm, Address, Decoder)))
5830     return MCDisassembler::Fail;
5831   // The lane index does not have any bits in the encoding, because it can only
5832   // be 0.
5833   Inst.addOperand(MCOperand::createImm(0));
5834   Inst.addOperand(MCOperand::createImm(rotate));
5835 
5836   return S;
5837 }
5838 
5839 static DecodeStatus DecodeLDR(MCInst &Inst, unsigned Val,
5840                                 uint64_t Address, const void *Decoder) {
5841   DecodeStatus S = MCDisassembler::Success;
5842 
5843   unsigned Rn = fieldFromInstruction(Val, 16, 4);
5844   unsigned Rt = fieldFromInstruction(Val, 12, 4);
5845   unsigned Rm = fieldFromInstruction(Val, 0, 4);
5846   Rm |= (fieldFromInstruction(Val, 23, 1) << 4);
5847   unsigned Cond = fieldFromInstruction(Val, 28, 4);
5848 
5849   if (fieldFromInstruction(Val, 8, 4) != 0 || Rn == Rt)
5850     S = MCDisassembler::SoftFail;
5851 
5852   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5853     return MCDisassembler::Fail;
5854   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
5855     return MCDisassembler::Fail;
5856   if (!Check(S, DecodeAddrMode7Operand(Inst, Rn, Address, Decoder)))
5857     return MCDisassembler::Fail;
5858   if (!Check(S, DecodePostIdxReg(Inst, Rm, Address, Decoder)))
5859     return MCDisassembler::Fail;
5860   if (!Check(S, DecodePredicateOperand(Inst, Cond, Address, Decoder)))
5861     return MCDisassembler::Fail;
5862 
5863   return S;
5864 }
5865 
5866 static DecodeStatus DecoderForMRRC2AndMCRR2(MCInst &Inst, unsigned Val,
5867                                             uint64_t Address, const void *Decoder) {
5868   DecodeStatus S = MCDisassembler::Success;
5869 
5870   unsigned CRm = fieldFromInstruction(Val, 0, 4);
5871   unsigned opc1 = fieldFromInstruction(Val, 4, 4);
5872   unsigned cop = fieldFromInstruction(Val, 8, 4);
5873   unsigned Rt = fieldFromInstruction(Val, 12, 4);
5874   unsigned Rt2 = fieldFromInstruction(Val, 16, 4);
5875 
5876   if ((cop & ~0x1) == 0xa)
5877     return MCDisassembler::Fail;
5878 
5879   if (Rt == Rt2)
5880     S = MCDisassembler::SoftFail;
5881 
5882   // We have to check if the instruction is MRRC2
5883   // or MCRR2 when constructing the operands for
5884   // Inst. Reason is because MRRC2 stores to two
5885   // registers so it's tablegen desc has has two
5886   // outputs whereas MCRR doesn't store to any
5887   // registers so all of it's operands are listed
5888   // as inputs, therefore the operand order for
5889   // MRRC2 needs to be [Rt, Rt2, cop, opc1, CRm]
5890   // and MCRR2 operand order is [cop, opc1, Rt, Rt2, CRm]
5891 
5892   if (Inst.getOpcode() == ARM::MRRC2) {
5893     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5894       return MCDisassembler::Fail;
5895     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5896       return MCDisassembler::Fail;
5897   }
5898   Inst.addOperand(MCOperand::createImm(cop));
5899   Inst.addOperand(MCOperand::createImm(opc1));
5900   if (Inst.getOpcode() == ARM::MCRR2) {
5901     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5902       return MCDisassembler::Fail;
5903     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5904       return MCDisassembler::Fail;
5905   }
5906   Inst.addOperand(MCOperand::createImm(CRm));
5907 
5908   return S;
5909 }
5910 
5911 static DecodeStatus DecodeForVMRSandVMSR(MCInst &Inst, unsigned Val,
5912                                          uint64_t Address,
5913                                          const void *Decoder) {
5914   const FeatureBitset &featureBits =
5915       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5916   DecodeStatus S = MCDisassembler::Success;
5917 
5918   // Add explicit operand for the destination sysreg, for cases where
5919   // we have to model it for code generation purposes.
5920   switch (Inst.getOpcode()) {
5921   case ARM::VMSR_FPSCR_NZCVQC:
5922     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
5923     break;
5924   case ARM::VMSR_P0:
5925     Inst.addOperand(MCOperand::createReg(ARM::VPR));
5926     break;
5927   }
5928 
5929   if (Inst.getOpcode() != ARM::FMSTAT) {
5930     unsigned Rt = fieldFromInstruction(Val, 12, 4);
5931 
5932     if (featureBits[ARM::ModeThumb] && !featureBits[ARM::HasV8Ops]) {
5933       if (Rt == 13 || Rt == 15)
5934         S = MCDisassembler::SoftFail;
5935       Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder));
5936     } else
5937       Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder));
5938   }
5939 
5940   // Add explicit operand for the source sysreg, similarly to above.
5941   switch (Inst.getOpcode()) {
5942   case ARM::VMRS_FPSCR_NZCVQC:
5943     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
5944     break;
5945   case ARM::VMRS_P0:
5946     Inst.addOperand(MCOperand::createReg(ARM::VPR));
5947     break;
5948   }
5949 
5950   if (featureBits[ARM::ModeThumb]) {
5951     Inst.addOperand(MCOperand::createImm(ARMCC::AL));
5952     Inst.addOperand(MCOperand::createReg(0));
5953   } else {
5954     unsigned pred = fieldFromInstruction(Val, 28, 4);
5955     if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5956       return MCDisassembler::Fail;
5957   }
5958 
5959   return S;
5960 }
5961 
5962 template <bool isSigned, bool isNeg, bool zeroPermitted, int size>
5963 static DecodeStatus DecodeBFLabelOperand(MCInst &Inst, unsigned Val,
5964                                          uint64_t Address,
5965                                          const void *Decoder) {
5966   DecodeStatus S = MCDisassembler::Success;
5967   if (Val == 0 && !zeroPermitted)
5968     S = MCDisassembler::Fail;
5969 
5970   uint64_t DecVal;
5971   if (isSigned)
5972     DecVal = SignExtend32<size + 1>(Val << 1);
5973   else
5974     DecVal = (Val << 1);
5975 
5976   if (!tryAddingSymbolicOperand(Address, Address + DecVal + 4, true, 4, Inst,
5977                                 Decoder))
5978     Inst.addOperand(MCOperand::createImm(isNeg ? -DecVal : DecVal));
5979   return S;
5980 }
5981 
5982 static DecodeStatus DecodeBFAfterTargetOperand(MCInst &Inst, unsigned Val,
5983                                                uint64_t Address,
5984                                                const void *Decoder) {
5985 
5986   uint64_t LocImm = Inst.getOperand(0).getImm();
5987   Val = LocImm + (2 << Val);
5988   if (!tryAddingSymbolicOperand(Address, Address + Val + 4, true, 4, Inst,
5989                                 Decoder))
5990     Inst.addOperand(MCOperand::createImm(Val));
5991   return MCDisassembler::Success;
5992 }
5993 
5994 static DecodeStatus DecodePredNoALOperand(MCInst &Inst, unsigned Val,
5995                                           uint64_t Address,
5996                                           const void *Decoder) {
5997   if (Val >= ARMCC::AL)  // also exclude the non-condition NV
5998     return MCDisassembler::Fail;
5999   Inst.addOperand(MCOperand::createImm(Val));
6000   return MCDisassembler::Success;
6001 }
6002 
6003 static DecodeStatus DecodeLOLoop(MCInst &Inst, unsigned Insn, uint64_t Address,
6004                                  const void *Decoder) {
6005   DecodeStatus S = MCDisassembler::Success;
6006 
6007   if (Inst.getOpcode() == ARM::MVE_LCTP)
6008     return S;
6009 
6010   unsigned Imm = fieldFromInstruction(Insn, 11, 1) |
6011                  fieldFromInstruction(Insn, 1, 10) << 1;
6012   switch (Inst.getOpcode()) {
6013   case ARM::t2LEUpdate:
6014   case ARM::MVE_LETP:
6015     Inst.addOperand(MCOperand::createReg(ARM::LR));
6016     Inst.addOperand(MCOperand::createReg(ARM::LR));
6017     LLVM_FALLTHROUGH;
6018   case ARM::t2LE:
6019     if (!Check(S, DecodeBFLabelOperand<false, true, true, 11>(
6020                    Inst, Imm, Address, Decoder)))
6021       return MCDisassembler::Fail;
6022     break;
6023   case ARM::t2WLS:
6024   case ARM::MVE_WLSTP_8:
6025   case ARM::MVE_WLSTP_16:
6026   case ARM::MVE_WLSTP_32:
6027   case ARM::MVE_WLSTP_64:
6028     Inst.addOperand(MCOperand::createReg(ARM::LR));
6029     if (!Check(S,
6030                DecoderGPRRegisterClass(Inst, fieldFromInstruction(Insn, 16, 4),
6031                                        Address, Decoder)) ||
6032         !Check(S, DecodeBFLabelOperand<false, false, true, 11>(
6033                    Inst, Imm, Address, Decoder)))
6034       return MCDisassembler::Fail;
6035     break;
6036   case ARM::t2DLS:
6037   case ARM::MVE_DLSTP_8:
6038   case ARM::MVE_DLSTP_16:
6039   case ARM::MVE_DLSTP_32:
6040   case ARM::MVE_DLSTP_64:
6041     unsigned Rn = fieldFromInstruction(Insn, 16, 4);
6042     if (Rn == 0xF) {
6043       // Enforce all the rest of the instruction bits in LCTP, which
6044       // won't have been reliably checked based on LCTP's own tablegen
6045       // record, because we came to this decode by a roundabout route.
6046       uint32_t CanonicalLCTP = 0xF00FE001, SBZMask = 0x00300FFE;
6047       if ((Insn & ~SBZMask) != CanonicalLCTP)
6048         return MCDisassembler::Fail;   // a mandatory bit is wrong: hard fail
6049       if (Insn != CanonicalLCTP)
6050         Check(S, MCDisassembler::SoftFail); // an SBZ bit is wrong: soft fail
6051 
6052       Inst.setOpcode(ARM::MVE_LCTP);
6053     } else {
6054       Inst.addOperand(MCOperand::createReg(ARM::LR));
6055       if (!Check(S, DecoderGPRRegisterClass(Inst,
6056                                             fieldFromInstruction(Insn, 16, 4),
6057                                             Address, Decoder)))
6058         return MCDisassembler::Fail;
6059     }
6060     break;
6061   }
6062   return S;
6063 }
6064 
6065 static DecodeStatus DecodeLongShiftOperand(MCInst &Inst, unsigned Val,
6066                                            uint64_t Address,
6067                                            const void *Decoder) {
6068   DecodeStatus S = MCDisassembler::Success;
6069 
6070   if (Val == 0)
6071     Val = 32;
6072 
6073   Inst.addOperand(MCOperand::createImm(Val));
6074 
6075   return S;
6076 }
6077 
6078 static DecodeStatus DecodetGPROddRegisterClass(MCInst &Inst, unsigned RegNo,
6079                                    uint64_t Address, const void *Decoder) {
6080   if ((RegNo) + 1 > 11)
6081     return MCDisassembler::Fail;
6082 
6083   unsigned Register = GPRDecoderTable[(RegNo) + 1];
6084   Inst.addOperand(MCOperand::createReg(Register));
6085   return MCDisassembler::Success;
6086 }
6087 
6088 static DecodeStatus DecodetGPREvenRegisterClass(MCInst &Inst, unsigned RegNo,
6089                                    uint64_t Address, const void *Decoder) {
6090   if ((RegNo) > 14)
6091     return MCDisassembler::Fail;
6092 
6093   unsigned Register = GPRDecoderTable[(RegNo)];
6094   Inst.addOperand(MCOperand::createReg(Register));
6095   return MCDisassembler::Success;
6096 }
6097 
6098 static DecodeStatus
6099 DecodeGPRwithAPSR_NZCVnospRegisterClass(MCInst &Inst, unsigned RegNo,
6100                                         uint64_t Address, const void *Decoder) {
6101   if (RegNo == 15) {
6102     Inst.addOperand(MCOperand::createReg(ARM::APSR_NZCV));
6103     return MCDisassembler::Success;
6104   }
6105 
6106   unsigned Register = GPRDecoderTable[RegNo];
6107   Inst.addOperand(MCOperand::createReg(Register));
6108 
6109   if (RegNo == 13)
6110     return MCDisassembler::SoftFail;
6111 
6112   return MCDisassembler::Success;
6113 }
6114 
6115 static DecodeStatus DecodeVSCCLRM(MCInst &Inst, unsigned Insn, uint64_t Address,
6116                                   const void *Decoder) {
6117   DecodeStatus S = MCDisassembler::Success;
6118 
6119   Inst.addOperand(MCOperand::createImm(ARMCC::AL));
6120   Inst.addOperand(MCOperand::createReg(0));
6121   if (Inst.getOpcode() == ARM::VSCCLRMD) {
6122     unsigned reglist = (fieldFromInstruction(Insn, 1, 7) << 1) |
6123                        (fieldFromInstruction(Insn, 12, 4) << 8) |
6124                        (fieldFromInstruction(Insn, 22, 1) << 12);
6125     if (!Check(S, DecodeDPRRegListOperand(Inst, reglist, Address, Decoder))) {
6126       return MCDisassembler::Fail;
6127     }
6128   } else {
6129     unsigned reglist = fieldFromInstruction(Insn, 0, 8) |
6130                        (fieldFromInstruction(Insn, 22, 1) << 8) |
6131                        (fieldFromInstruction(Insn, 12, 4) << 9);
6132     if (!Check(S, DecodeSPRRegListOperand(Inst, reglist, Address, Decoder))) {
6133       return MCDisassembler::Fail;
6134     }
6135   }
6136   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6137 
6138   return S;
6139 }
6140 
6141 static DecodeStatus DecodeMQPRRegisterClass(MCInst &Inst, unsigned RegNo,
6142                               uint64_t Address,
6143                               const void *Decoder) {
6144   if (RegNo > 7)
6145     return MCDisassembler::Fail;
6146 
6147   unsigned Register = QPRDecoderTable[RegNo];
6148   Inst.addOperand(MCOperand::createReg(Register));
6149   return MCDisassembler::Success;
6150 }
6151 
6152 static const uint16_t QQPRDecoderTable[] = {
6153      ARM::Q0_Q1,  ARM::Q1_Q2,  ARM::Q2_Q3,  ARM::Q3_Q4,
6154      ARM::Q4_Q5,  ARM::Q5_Q6,  ARM::Q6_Q7
6155 };
6156 
6157 static DecodeStatus DecodeQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
6158                               uint64_t Address,
6159                               const void *Decoder) {
6160   if (RegNo > 6)
6161     return MCDisassembler::Fail;
6162 
6163   unsigned Register = QQPRDecoderTable[RegNo];
6164   Inst.addOperand(MCOperand::createReg(Register));
6165   return MCDisassembler::Success;
6166 }
6167 
6168 static const uint16_t QQQQPRDecoderTable[] = {
6169      ARM::Q0_Q1_Q2_Q3,  ARM::Q1_Q2_Q3_Q4,  ARM::Q2_Q3_Q4_Q5,
6170      ARM::Q3_Q4_Q5_Q6,  ARM::Q4_Q5_Q6_Q7
6171 };
6172 
6173 static DecodeStatus DecodeQQQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
6174                               uint64_t Address,
6175                               const void *Decoder) {
6176   if (RegNo > 4)
6177     return MCDisassembler::Fail;
6178 
6179   unsigned Register = QQQQPRDecoderTable[RegNo];
6180   Inst.addOperand(MCOperand::createReg(Register));
6181   return MCDisassembler::Success;
6182 }
6183 
6184 static DecodeStatus DecodeVPTMaskOperand(MCInst &Inst, unsigned Val,
6185                                          uint64_t Address,
6186                                          const void *Decoder) {
6187   DecodeStatus S = MCDisassembler::Success;
6188 
6189   // Parse VPT mask and encode it in the MCInst as an immediate with the same
6190   // format as the it_mask.  That is, from the second 'e|t' encode 'e' as 1 and
6191   // 't' as 0 and finish with a 1.
6192   unsigned Imm = 0;
6193   // We always start with a 't'.
6194   unsigned CurBit = 0;
6195   for (int i = 3; i >= 0; --i) {
6196     // If the bit we are looking at is not the same as last one, invert the
6197     // CurBit, if it is the same leave it as is.
6198     CurBit ^= (Val >> i) & 1U;
6199 
6200     // Encode the CurBit at the right place in the immediate.
6201     Imm |= (CurBit << i);
6202 
6203     // If we are done, finish the encoding with a 1.
6204     if ((Val & ~(~0U << i)) == 0) {
6205       Imm |= 1U << i;
6206       break;
6207     }
6208   }
6209 
6210   Inst.addOperand(MCOperand::createImm(Imm));
6211 
6212   return S;
6213 }
6214 
6215 static DecodeStatus DecodeVpredROperand(MCInst &Inst, unsigned RegNo,
6216                                         uint64_t Address, const void *Decoder) {
6217   // The vpred_r operand type includes an MQPR register field derived
6218   // from the encoding. But we don't actually want to add an operand
6219   // to the MCInst at this stage, because AddThumbPredicate will do it
6220   // later, and will infer the register number from the TIED_TO
6221   // constraint. So this is a deliberately empty decoder method that
6222   // will inhibit the auto-generated disassembly code from adding an
6223   // operand at all.
6224   return MCDisassembler::Success;
6225 }
6226 
6227 static DecodeStatus DecodeRestrictedIPredicateOperand(MCInst &Inst,
6228                                                       unsigned Val,
6229                                                       uint64_t Address,
6230                                                       const void *Decoder) {
6231   Inst.addOperand(MCOperand::createImm((Val & 0x1) == 0 ? ARMCC::EQ : ARMCC::NE));
6232   return MCDisassembler::Success;
6233 }
6234 
6235 static DecodeStatus DecodeRestrictedSPredicateOperand(MCInst &Inst,
6236                                                       unsigned Val,
6237                                                       uint64_t Address,
6238                                                       const void *Decoder) {
6239   unsigned Code;
6240   switch (Val & 0x3) {
6241   case 0:
6242     Code = ARMCC::GE;
6243     break;
6244   case 1:
6245     Code = ARMCC::LT;
6246     break;
6247   case 2:
6248     Code = ARMCC::GT;
6249     break;
6250   case 3:
6251     Code = ARMCC::LE;
6252     break;
6253   }
6254   Inst.addOperand(MCOperand::createImm(Code));
6255   return MCDisassembler::Success;
6256 }
6257 
6258 static DecodeStatus DecodeRestrictedUPredicateOperand(MCInst &Inst,
6259                                                       unsigned Val,
6260                                                       uint64_t Address,
6261                                                       const void *Decoder) {
6262   Inst.addOperand(MCOperand::createImm((Val & 0x1) == 0 ? ARMCC::HS : ARMCC::HI));
6263   return MCDisassembler::Success;
6264 }
6265 
6266 static DecodeStatus DecodeRestrictedFPPredicateOperand(MCInst &Inst, unsigned Val,
6267                                                      uint64_t Address,
6268                                                      const void *Decoder) {
6269   unsigned Code;
6270   switch (Val) {
6271   default:
6272     return MCDisassembler::Fail;
6273   case 0:
6274     Code = ARMCC::EQ;
6275     break;
6276   case 1:
6277     Code = ARMCC::NE;
6278     break;
6279   case 4:
6280     Code = ARMCC::GE;
6281     break;
6282   case 5:
6283     Code = ARMCC::LT;
6284     break;
6285   case 6:
6286     Code = ARMCC::GT;
6287     break;
6288   case 7:
6289     Code = ARMCC::LE;
6290     break;
6291   }
6292 
6293   Inst.addOperand(MCOperand::createImm(Code));
6294   return MCDisassembler::Success;
6295 }
6296 
6297 static DecodeStatus DecodeVCVTImmOperand(MCInst &Inst, unsigned Val,
6298                                          uint64_t Address, const void *Decoder) {
6299   DecodeStatus S = MCDisassembler::Success;
6300 
6301   unsigned DecodedVal = 64 - Val;
6302 
6303   switch (Inst.getOpcode()) {
6304   case ARM::MVE_VCVTf16s16_fix:
6305   case ARM::MVE_VCVTs16f16_fix:
6306   case ARM::MVE_VCVTf16u16_fix:
6307   case ARM::MVE_VCVTu16f16_fix:
6308     if (DecodedVal > 16)
6309       return MCDisassembler::Fail;
6310     break;
6311   case ARM::MVE_VCVTf32s32_fix:
6312   case ARM::MVE_VCVTs32f32_fix:
6313   case ARM::MVE_VCVTf32u32_fix:
6314   case ARM::MVE_VCVTu32f32_fix:
6315     if (DecodedVal > 32)
6316       return MCDisassembler::Fail;
6317     break;
6318   }
6319 
6320   Inst.addOperand(MCOperand::createImm(64 - Val));
6321 
6322   return S;
6323 }
6324 
6325 static unsigned FixedRegForVSTRVLDR_SYSREG(unsigned Opcode) {
6326   switch (Opcode) {
6327   case ARM::VSTR_P0_off:
6328   case ARM::VSTR_P0_pre:
6329   case ARM::VSTR_P0_post:
6330   case ARM::VLDR_P0_off:
6331   case ARM::VLDR_P0_pre:
6332   case ARM::VLDR_P0_post:
6333     return ARM::P0;
6334   default:
6335     return 0;
6336   }
6337 }
6338 
6339 template<bool Writeback>
6340 static DecodeStatus DecodeVSTRVLDR_SYSREG(MCInst &Inst, unsigned Val,
6341                                           uint64_t Address,
6342                                           const void *Decoder) {
6343   switch (Inst.getOpcode()) {
6344   case ARM::VSTR_FPSCR_pre:
6345   case ARM::VSTR_FPSCR_NZCVQC_pre:
6346   case ARM::VLDR_FPSCR_pre:
6347   case ARM::VLDR_FPSCR_NZCVQC_pre:
6348   case ARM::VSTR_FPSCR_off:
6349   case ARM::VSTR_FPSCR_NZCVQC_off:
6350   case ARM::VLDR_FPSCR_off:
6351   case ARM::VLDR_FPSCR_NZCVQC_off:
6352   case ARM::VSTR_FPSCR_post:
6353   case ARM::VSTR_FPSCR_NZCVQC_post:
6354   case ARM::VLDR_FPSCR_post:
6355   case ARM::VLDR_FPSCR_NZCVQC_post:
6356     const FeatureBitset &featureBits =
6357         ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
6358 
6359     if (!featureBits[ARM::HasMVEIntegerOps] && !featureBits[ARM::FeatureVFP2])
6360       return MCDisassembler::Fail;
6361   }
6362 
6363   DecodeStatus S = MCDisassembler::Success;
6364   if (unsigned Sysreg = FixedRegForVSTRVLDR_SYSREG(Inst.getOpcode()))
6365     Inst.addOperand(MCOperand::createReg(Sysreg));
6366   unsigned Rn = fieldFromInstruction(Val, 16, 4);
6367   unsigned addr = fieldFromInstruction(Val, 0, 7) |
6368                   (fieldFromInstruction(Val, 23, 1) << 7) | (Rn << 8);
6369 
6370   if (Writeback) {
6371     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
6372       return MCDisassembler::Fail;
6373   }
6374   if (!Check(S, DecodeT2AddrModeImm7s4(Inst, addr, Address, Decoder)))
6375     return MCDisassembler::Fail;
6376 
6377   Inst.addOperand(MCOperand::createImm(ARMCC::AL));
6378   Inst.addOperand(MCOperand::createReg(0));
6379 
6380   return S;
6381 }
6382 
6383 static inline DecodeStatus DecodeMVE_MEM_pre(
6384   MCInst &Inst, unsigned Val, uint64_t Address, const void *Decoder,
6385   unsigned Rn, OperandDecoder RnDecoder, OperandDecoder AddrDecoder) {
6386   DecodeStatus S = MCDisassembler::Success;
6387 
6388   unsigned Qd = fieldFromInstruction(Val, 13, 3);
6389   unsigned addr = fieldFromInstruction(Val, 0, 7) |
6390                   (fieldFromInstruction(Val, 23, 1) << 7) | (Rn << 8);
6391 
6392   if (!Check(S, RnDecoder(Inst, Rn, Address, Decoder)))
6393     return MCDisassembler::Fail;
6394   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6395     return MCDisassembler::Fail;
6396   if (!Check(S, AddrDecoder(Inst, addr, Address, Decoder)))
6397     return MCDisassembler::Fail;
6398 
6399   return S;
6400 }
6401 
6402 template <int shift>
6403 static DecodeStatus DecodeMVE_MEM_1_pre(MCInst &Inst, unsigned Val,
6404                                         uint64_t Address, const void *Decoder) {
6405   return DecodeMVE_MEM_pre(Inst, Val, Address, Decoder,
6406                            fieldFromInstruction(Val, 16, 3),
6407                            DecodetGPRRegisterClass,
6408                            DecodeTAddrModeImm7<shift>);
6409 }
6410 
6411 template <int shift>
6412 static DecodeStatus DecodeMVE_MEM_2_pre(MCInst &Inst, unsigned Val,
6413                                         uint64_t Address, const void *Decoder) {
6414   return DecodeMVE_MEM_pre(Inst, Val, Address, Decoder,
6415                            fieldFromInstruction(Val, 16, 4),
6416                            DecoderGPRRegisterClass,
6417                            DecodeT2AddrModeImm7<shift,1>);
6418 }
6419 
6420 template <int shift>
6421 static DecodeStatus DecodeMVE_MEM_3_pre(MCInst &Inst, unsigned Val,
6422                                         uint64_t Address, const void *Decoder) {
6423   return DecodeMVE_MEM_pre(Inst, Val, Address, Decoder,
6424                            fieldFromInstruction(Val, 17, 3),
6425                            DecodeMQPRRegisterClass,
6426                            DecodeMveAddrModeQ<shift>);
6427 }
6428 
6429 template<unsigned MinLog, unsigned MaxLog>
6430 static DecodeStatus DecodePowerTwoOperand(MCInst &Inst, unsigned Val,
6431                                           uint64_t Address,
6432                                           const void *Decoder) {
6433   DecodeStatus S = MCDisassembler::Success;
6434 
6435   if (Val < MinLog || Val > MaxLog)
6436     return MCDisassembler::Fail;
6437 
6438   Inst.addOperand(MCOperand::createImm(1LL << Val));
6439   return S;
6440 }
6441 
6442 template<unsigned start>
6443 static DecodeStatus DecodeMVEPairVectorIndexOperand(MCInst &Inst, unsigned Val,
6444                                                     uint64_t Address,
6445                                                     const void *Decoder) {
6446   DecodeStatus S = MCDisassembler::Success;
6447 
6448   Inst.addOperand(MCOperand::createImm(start + Val));
6449 
6450   return S;
6451 }
6452 
6453 static DecodeStatus DecodeMVEVMOVQtoDReg(MCInst &Inst, unsigned Insn,
6454                                          uint64_t Address, const void *Decoder) {
6455   DecodeStatus S = MCDisassembler::Success;
6456   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
6457   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
6458   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
6459                  fieldFromInstruction(Insn, 13, 3));
6460   unsigned index = fieldFromInstruction(Insn, 4, 1);
6461 
6462   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
6463     return MCDisassembler::Fail;
6464   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2, Address, Decoder)))
6465     return MCDisassembler::Fail;
6466   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6467     return MCDisassembler::Fail;
6468   if (!Check(S, DecodeMVEPairVectorIndexOperand<2>(Inst, index, Address, Decoder)))
6469     return MCDisassembler::Fail;
6470   if (!Check(S, DecodeMVEPairVectorIndexOperand<0>(Inst, index, Address, Decoder)))
6471     return MCDisassembler::Fail;
6472 
6473   return S;
6474 }
6475 
6476 static DecodeStatus DecodeMVEVMOVDRegtoQ(MCInst &Inst, unsigned Insn,
6477                                          uint64_t Address, const void *Decoder) {
6478   DecodeStatus S = MCDisassembler::Success;
6479   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
6480   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
6481   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
6482                  fieldFromInstruction(Insn, 13, 3));
6483   unsigned index = fieldFromInstruction(Insn, 4, 1);
6484 
6485   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6486     return MCDisassembler::Fail;
6487   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6488     return MCDisassembler::Fail;
6489   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
6490     return MCDisassembler::Fail;
6491   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2, Address, Decoder)))
6492     return MCDisassembler::Fail;
6493   if (!Check(S, DecodeMVEPairVectorIndexOperand<2>(Inst, index, Address, Decoder)))
6494     return MCDisassembler::Fail;
6495   if (!Check(S, DecodeMVEPairVectorIndexOperand<0>(Inst, index, Address, Decoder)))
6496     return MCDisassembler::Fail;
6497 
6498   return S;
6499 }
6500 
6501 static DecodeStatus DecodeMVEOverlappingLongShift(
6502   MCInst &Inst, unsigned Insn, uint64_t Address, const void *Decoder) {
6503   DecodeStatus S = MCDisassembler::Success;
6504 
6505   unsigned RdaLo = fieldFromInstruction(Insn, 17, 3) << 1;
6506   unsigned RdaHi = fieldFromInstruction(Insn, 9, 3) << 1;
6507   unsigned Rm = fieldFromInstruction(Insn, 12, 4);
6508 
6509   if (RdaHi == 14) {
6510     // This value of RdaHi (really indicating pc, because RdaHi has to
6511     // be an odd-numbered register, so the low bit will be set by the
6512     // decode function below) indicates that we must decode as SQRSHR
6513     // or UQRSHL, which both have a single Rda register field with all
6514     // four bits.
6515     unsigned Rda = fieldFromInstruction(Insn, 16, 4);
6516 
6517     switch (Inst.getOpcode()) {
6518       case ARM::MVE_ASRLr:
6519       case ARM::MVE_SQRSHRL:
6520         Inst.setOpcode(ARM::MVE_SQRSHR);
6521         break;
6522       case ARM::MVE_LSLLr:
6523       case ARM::MVE_UQRSHLL:
6524         Inst.setOpcode(ARM::MVE_UQRSHL);
6525         break;
6526       default:
6527         llvm_unreachable("Unexpected starting opcode!");
6528     }
6529 
6530     // Rda as output parameter
6531     if (!Check(S, DecoderGPRRegisterClass(Inst, Rda, Address, Decoder)))
6532       return MCDisassembler::Fail;
6533 
6534     // Rda again as input parameter
6535     if (!Check(S, DecoderGPRRegisterClass(Inst, Rda, Address, Decoder)))
6536       return MCDisassembler::Fail;
6537 
6538     // Rm, the amount to shift by
6539     if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
6540       return MCDisassembler::Fail;
6541 
6542     if (fieldFromInstruction (Insn, 6, 3) != 4)
6543       return MCDisassembler::SoftFail;
6544 
6545     if (Rda == Rm)
6546       return MCDisassembler::SoftFail;
6547 
6548     return S;
6549   }
6550 
6551   // Otherwise, we decode as whichever opcode our caller has already
6552   // put into Inst. Those all look the same:
6553 
6554   // RdaLo,RdaHi as output parameters
6555   if (!Check(S, DecodetGPREvenRegisterClass(Inst, RdaLo, Address, Decoder)))
6556     return MCDisassembler::Fail;
6557   if (!Check(S, DecodetGPROddRegisterClass(Inst, RdaHi, Address, Decoder)))
6558     return MCDisassembler::Fail;
6559 
6560   // RdaLo,RdaHi again as input parameters
6561   if (!Check(S, DecodetGPREvenRegisterClass(Inst, RdaLo, Address, Decoder)))
6562     return MCDisassembler::Fail;
6563   if (!Check(S, DecodetGPROddRegisterClass(Inst, RdaHi, Address, Decoder)))
6564     return MCDisassembler::Fail;
6565 
6566   // Rm, the amount to shift by
6567   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
6568     return MCDisassembler::Fail;
6569 
6570   if (Inst.getOpcode() == ARM::MVE_SQRSHRL ||
6571       Inst.getOpcode() == ARM::MVE_UQRSHLL) {
6572     unsigned Saturate = fieldFromInstruction(Insn, 7, 1);
6573     // Saturate, the bit position for saturation
6574     Inst.addOperand(MCOperand::createImm(Saturate));
6575   }
6576 
6577   return S;
6578 }
6579 
6580 static DecodeStatus DecodeMVEVCVTt1fp(MCInst &Inst, unsigned Insn, uint64_t Address,
6581                                       const void *Decoder) {
6582   DecodeStatus S = MCDisassembler::Success;
6583   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
6584                  fieldFromInstruction(Insn, 13, 3));
6585   unsigned Qm = ((fieldFromInstruction(Insn, 5, 1) << 3) |
6586                  fieldFromInstruction(Insn, 1, 3));
6587   unsigned imm6 = fieldFromInstruction(Insn, 16, 6);
6588 
6589   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6590     return MCDisassembler::Fail;
6591   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
6592     return MCDisassembler::Fail;
6593   if (!Check(S, DecodeVCVTImmOperand(Inst, imm6, Address, Decoder)))
6594     return MCDisassembler::Fail;
6595 
6596   return S;
6597 }
6598 
6599 template<bool scalar, OperandDecoder predicate_decoder>
6600 static DecodeStatus DecodeMVEVCMP(MCInst &Inst, unsigned Insn, uint64_t Address,
6601                                   const void *Decoder) {
6602   DecodeStatus S = MCDisassembler::Success;
6603   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6604   unsigned Qn = fieldFromInstruction(Insn, 17, 3);
6605   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qn, Address, Decoder)))
6606     return MCDisassembler::Fail;
6607 
6608   unsigned fc;
6609 
6610   if (scalar) {
6611     fc = fieldFromInstruction(Insn, 12, 1) << 2 |
6612          fieldFromInstruction(Insn, 7, 1) |
6613          fieldFromInstruction(Insn, 5, 1) << 1;
6614     unsigned Rm = fieldFromInstruction(Insn, 0, 4);
6615     if (!Check(S, DecodeGPRwithZRRegisterClass(Inst, Rm, Address, Decoder)))
6616       return MCDisassembler::Fail;
6617   } else {
6618     fc = fieldFromInstruction(Insn, 12, 1) << 2 |
6619          fieldFromInstruction(Insn, 7, 1) |
6620          fieldFromInstruction(Insn, 0, 1) << 1;
6621     unsigned Qm = fieldFromInstruction(Insn, 5, 1) << 4 |
6622                   fieldFromInstruction(Insn, 1, 3);
6623     if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
6624       return MCDisassembler::Fail;
6625   }
6626 
6627   if (!Check(S, predicate_decoder(Inst, fc, Address, Decoder)))
6628     return MCDisassembler::Fail;
6629 
6630   Inst.addOperand(MCOperand::createImm(ARMVCC::None));
6631   Inst.addOperand(MCOperand::createReg(0));
6632   Inst.addOperand(MCOperand::createImm(0));
6633 
6634   return S;
6635 }
6636 
6637 static DecodeStatus DecodeMveVCTP(MCInst &Inst, unsigned Insn, uint64_t Address,
6638                                   const void *Decoder) {
6639   DecodeStatus S = MCDisassembler::Success;
6640   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6641   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
6642   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
6643     return MCDisassembler::Fail;
6644   return S;
6645 }
6646 
6647 static DecodeStatus DecodeMVEVPNOT(MCInst &Inst, unsigned Insn, uint64_t Address,
6648                                    const void *Decoder) {
6649   DecodeStatus S = MCDisassembler::Success;
6650   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6651   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6652   return S;
6653 }
6654 
6655 static DecodeStatus DecodeT2AddSubSPImm(MCInst &Inst, unsigned Insn,
6656                                         uint64_t Address, const void *Decoder) {
6657   const unsigned Rd = fieldFromInstruction(Insn, 8, 4);
6658   const unsigned Rn = fieldFromInstruction(Insn, 16, 4);
6659   const unsigned Imm12 = fieldFromInstruction(Insn, 26, 1) << 11 |
6660                          fieldFromInstruction(Insn, 12, 3) << 8 |
6661                          fieldFromInstruction(Insn, 0, 8);
6662   const unsigned TypeT3 = fieldFromInstruction(Insn, 25, 1);
6663   unsigned sign1 = fieldFromInstruction(Insn, 21, 1);
6664   unsigned sign2 = fieldFromInstruction(Insn, 23, 1);
6665   unsigned S = fieldFromInstruction(Insn, 20, 1);
6666   if (sign1 != sign2)
6667     return MCDisassembler::Fail;
6668 
6669   // T3 does a zext of imm12, where T2 does a ThumbExpandImm (T2SOImm)
6670   DecodeStatus DS = MCDisassembler::Success;
6671   if ((!Check(DS,
6672               DecodeGPRspRegisterClass(Inst, Rd, Address, Decoder))) || // dst
6673       (!Check(DS, DecodeGPRspRegisterClass(Inst, Rn, Address, Decoder))))
6674     return MCDisassembler::Fail;
6675   if (TypeT3) {
6676     Inst.setOpcode(sign1 ? ARM::t2SUBspImm12 : ARM::t2ADDspImm12);
6677     Inst.addOperand(MCOperand::createImm(Imm12)); // zext imm12
6678   } else {
6679     Inst.setOpcode(sign1 ? ARM::t2SUBspImm : ARM::t2ADDspImm);
6680     if (!Check(DS, DecodeT2SOImm(Inst, Imm12, Address, Decoder))) // imm12
6681       return MCDisassembler::Fail;
6682     if (!Check(DS, DecodeCCOutOperand(Inst, S, Address, Decoder))) // cc_out
6683       return MCDisassembler::Fail;
6684   }
6685 
6686   return DS;
6687 }
6688