xref: /llvm-project/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp (revision 6fdd6a7b3f696972edc244488f59532d05136a27)
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 DecodeGPRnopcRegisterClass(MCInst &Inst,
186                                                unsigned RegNo, uint64_t Address,
187                                                const void *Decoder);
188 static DecodeStatus DecodeGPRwithAPSRRegisterClass(MCInst &Inst,
189                                                unsigned RegNo, uint64_t Address,
190                                                const void *Decoder);
191 static DecodeStatus DecodeGPRwithZRRegisterClass(MCInst &Inst,
192                                                unsigned RegNo, uint64_t Address,
193                                                const void *Decoder);
194 static DecodeStatus DecodeGPRwithZRnospRegisterClass(
195     MCInst &Inst, unsigned RegNo, uint64_t Address, const void *Decoder);
196 static DecodeStatus DecodetGPRRegisterClass(MCInst &Inst, unsigned RegNo,
197                                    uint64_t Address, const void *Decoder);
198 static DecodeStatus DecodetcGPRRegisterClass(MCInst &Inst, unsigned RegNo,
199                                    uint64_t Address, const void *Decoder);
200 static DecodeStatus DecoderGPRRegisterClass(MCInst &Inst, unsigned RegNo,
201                                    uint64_t Address, const void *Decoder);
202 static DecodeStatus DecodeGPRPairRegisterClass(MCInst &Inst, unsigned RegNo,
203                                    uint64_t Address, const void *Decoder);
204 static DecodeStatus DecodeHPRRegisterClass(MCInst &Inst, unsigned RegNo,
205                                    uint64_t Address, const void *Decoder);
206 static DecodeStatus DecodeSPRRegisterClass(MCInst &Inst, unsigned RegNo,
207                                    uint64_t Address, const void *Decoder);
208 static DecodeStatus DecodeDPRRegisterClass(MCInst &Inst, unsigned RegNo,
209                                    uint64_t Address, const void *Decoder);
210 static DecodeStatus DecodeDPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
211                                    uint64_t Address, const void *Decoder);
212 static DecodeStatus DecodeSPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
213                                    uint64_t Address, const void *Decoder);
214 static DecodeStatus DecodeDPR_VFP2RegisterClass(MCInst &Inst,
215                                                 unsigned RegNo,
216                                                 uint64_t Address,
217                                                 const void *Decoder);
218 static DecodeStatus DecodeQPRRegisterClass(MCInst &Inst, unsigned RegNo,
219                                    uint64_t Address, const void *Decoder);
220 static DecodeStatus DecodeMQPRRegisterClass(MCInst &Inst, unsigned RegNo,
221                                    uint64_t Address, const void *Decoder);
222 static DecodeStatus DecodeQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
223                                    uint64_t Address, const void *Decoder);
224 static DecodeStatus DecodeQQQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
225                                    uint64_t Address, const void *Decoder);
226 static DecodeStatus DecodeDPairRegisterClass(MCInst &Inst, unsigned RegNo,
227                                    uint64_t Address, const void *Decoder);
228 static DecodeStatus DecodeDPairSpacedRegisterClass(MCInst &Inst,
229                                unsigned RegNo, uint64_t Address,
230                                const void *Decoder);
231 
232 static DecodeStatus DecodePredicateOperand(MCInst &Inst, unsigned Val,
233                                uint64_t Address, const void *Decoder);
234 static DecodeStatus DecodeCCOutOperand(MCInst &Inst, unsigned Val,
235                                uint64_t Address, const void *Decoder);
236 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Val,
237                                uint64_t Address, const void *Decoder);
238 static DecodeStatus DecodeSPRRegListOperand(MCInst &Inst, unsigned Val,
239                                uint64_t Address, const void *Decoder);
240 static DecodeStatus DecodeDPRRegListOperand(MCInst &Inst, unsigned Val,
241                                uint64_t Address, const void *Decoder);
242 
243 static DecodeStatus DecodeBitfieldMaskOperand(MCInst &Inst, unsigned Insn,
244                                uint64_t Address, const void *Decoder);
245 static DecodeStatus DecodeCopMemInstruction(MCInst &Inst, unsigned Insn,
246                                uint64_t Address, const void *Decoder);
247 static DecodeStatus DecodeAddrMode2IdxInstruction(MCInst &Inst,
248                                                   unsigned Insn,
249                                                   uint64_t Address,
250                                                   const void *Decoder);
251 static DecodeStatus DecodeSORegMemOperand(MCInst &Inst, unsigned Insn,
252                                uint64_t Address, const void *Decoder);
253 static DecodeStatus DecodeAddrMode3Instruction(MCInst &Inst,unsigned Insn,
254                                uint64_t Address, const void *Decoder);
255 static DecodeStatus DecodeSORegImmOperand(MCInst &Inst, unsigned Insn,
256                                uint64_t Address, const void *Decoder);
257 static DecodeStatus DecodeSORegRegOperand(MCInst &Inst, unsigned Insn,
258                                uint64_t Address, const void *Decoder);
259 
260 static DecodeStatus DecodeMemMultipleWritebackInstruction(MCInst & Inst,
261                                                   unsigned Insn,
262                                                   uint64_t Adddress,
263                                                   const void *Decoder);
264 static DecodeStatus DecodeT2MOVTWInstruction(MCInst &Inst, unsigned Insn,
265                                uint64_t Address, const void *Decoder);
266 static DecodeStatus DecodeArmMOVTWInstruction(MCInst &Inst, unsigned Insn,
267                                uint64_t Address, const void *Decoder);
268 static DecodeStatus DecodeSMLAInstruction(MCInst &Inst, unsigned Insn,
269                                uint64_t Address, const void *Decoder);
270 static DecodeStatus DecodeHINTInstruction(MCInst &Inst, unsigned Insn,
271                                uint64_t Address, const void *Decoder);
272 static DecodeStatus DecodeCPSInstruction(MCInst &Inst, unsigned Insn,
273                                uint64_t Address, const void *Decoder);
274 static DecodeStatus DecodeTSTInstruction(MCInst &Inst, unsigned Insn,
275                                uint64_t Address, const void *Decoder);
276 static DecodeStatus DecodeSETPANInstruction(MCInst &Inst, unsigned Insn,
277                                uint64_t Address, const void *Decoder);
278 static DecodeStatus DecodeT2CPSInstruction(MCInst &Inst, unsigned Insn,
279                                uint64_t Address, const void *Decoder);
280 static DecodeStatus DecodeAddrModeImm12Operand(MCInst &Inst, unsigned Val,
281                                uint64_t Address, const void *Decoder);
282 static DecodeStatus DecodeAddrMode5Operand(MCInst &Inst, unsigned Val,
283                                uint64_t Address, const void *Decoder);
284 static DecodeStatus DecodeAddrMode5FP16Operand(MCInst &Inst, unsigned Val,
285                                uint64_t Address, const void *Decoder);
286 static DecodeStatus DecodeAddrMode7Operand(MCInst &Inst, unsigned Val,
287                                uint64_t Address, const void *Decoder);
288 static DecodeStatus DecodeT2BInstruction(MCInst &Inst, unsigned Insn,
289                                uint64_t Address, const void *Decoder);
290 static DecodeStatus DecodeBranchImmInstruction(MCInst &Inst,unsigned Insn,
291                                uint64_t Address, const void *Decoder);
292 static DecodeStatus DecodeAddrMode6Operand(MCInst &Inst, unsigned Val,
293                                uint64_t Address, const void *Decoder);
294 static DecodeStatus DecodeVLDST1Instruction(MCInst &Inst, unsigned Val,
295                                uint64_t Address, const void *Decoder);
296 static DecodeStatus DecodeVLDST2Instruction(MCInst &Inst, unsigned Val,
297                                uint64_t Address, const void *Decoder);
298 static DecodeStatus DecodeVLDST3Instruction(MCInst &Inst, unsigned Val,
299                                uint64_t Address, const void *Decoder);
300 static DecodeStatus DecodeVLDST4Instruction(MCInst &Inst, unsigned Val,
301                                uint64_t Address, const void *Decoder);
302 static DecodeStatus DecodeVLDInstruction(MCInst &Inst, unsigned Val,
303                                uint64_t Address, const void *Decoder);
304 static DecodeStatus DecodeVSTInstruction(MCInst &Inst, unsigned Val,
305                                uint64_t Address, const void *Decoder);
306 static DecodeStatus DecodeVLD1DupInstruction(MCInst &Inst, unsigned Val,
307                                uint64_t Address, const void *Decoder);
308 static DecodeStatus DecodeVLD2DupInstruction(MCInst &Inst, unsigned Val,
309                                uint64_t Address, const void *Decoder);
310 static DecodeStatus DecodeVLD3DupInstruction(MCInst &Inst, unsigned Val,
311                                uint64_t Address, const void *Decoder);
312 static DecodeStatus DecodeVLD4DupInstruction(MCInst &Inst, unsigned Val,
313                                uint64_t Address, const void *Decoder);
314 static DecodeStatus DecodeVMOVModImmInstruction(MCInst &Inst,unsigned Val,
315                                uint64_t Address, const void *Decoder);
316 static DecodeStatus DecodeMVEModImmInstruction(MCInst &Inst,unsigned Val,
317                                uint64_t Address, const void *Decoder);
318 static DecodeStatus DecodeMVEVADCInstruction(MCInst &Inst, unsigned Insn,
319                                uint64_t Address, const void *Decoder);
320 static DecodeStatus DecodeVSHLMaxInstruction(MCInst &Inst, unsigned Val,
321                                uint64_t Address, const void *Decoder);
322 static DecodeStatus DecodeShiftRight8Imm(MCInst &Inst, unsigned Val,
323                                uint64_t Address, const void *Decoder);
324 static DecodeStatus DecodeShiftRight16Imm(MCInst &Inst, unsigned Val,
325                                uint64_t Address, const void *Decoder);
326 static DecodeStatus DecodeShiftRight32Imm(MCInst &Inst, unsigned Val,
327                                uint64_t Address, const void *Decoder);
328 static DecodeStatus DecodeShiftRight64Imm(MCInst &Inst, unsigned Val,
329                                uint64_t Address, const void *Decoder);
330 static DecodeStatus DecodeTBLInstruction(MCInst &Inst, unsigned Insn,
331                                uint64_t Address, const void *Decoder);
332 static DecodeStatus DecodePostIdxReg(MCInst &Inst, unsigned Insn,
333                                uint64_t Address, const void *Decoder);
334 static DecodeStatus DecodeMveAddrModeRQ(MCInst &Inst, unsigned Insn,
335                                uint64_t Address, const void *Decoder);
336 template<int shift>
337 static DecodeStatus DecodeMveAddrModeQ(MCInst &Inst, unsigned Insn,
338                                uint64_t Address, const void *Decoder);
339 static DecodeStatus DecodeCoprocessor(MCInst &Inst, unsigned Insn,
340                                uint64_t Address, const void *Decoder);
341 static DecodeStatus DecodeMemBarrierOption(MCInst &Inst, unsigned Insn,
342                                uint64_t Address, const void *Decoder);
343 static DecodeStatus DecodeInstSyncBarrierOption(MCInst &Inst, unsigned Insn,
344                                uint64_t Address, const void *Decoder);
345 static DecodeStatus DecodeMSRMask(MCInst &Inst, unsigned Insn,
346                                uint64_t Address, const void *Decoder);
347 static DecodeStatus DecodeBankedReg(MCInst &Inst, unsigned Insn,
348                                uint64_t Address, const void *Decoder);
349 static DecodeStatus DecodeDoubleRegLoad(MCInst &Inst, unsigned Insn,
350                                uint64_t Address, const void *Decoder);
351 static DecodeStatus DecodeDoubleRegStore(MCInst &Inst, unsigned Insn,
352                                uint64_t Address, const void *Decoder);
353 static DecodeStatus DecodeLDRPreImm(MCInst &Inst, unsigned Insn,
354                                uint64_t Address, const void *Decoder);
355 static DecodeStatus DecodeLDRPreReg(MCInst &Inst, unsigned Insn,
356                                uint64_t Address, const void *Decoder);
357 static DecodeStatus DecodeSTRPreImm(MCInst &Inst, unsigned Insn,
358                                uint64_t Address, const void *Decoder);
359 static DecodeStatus DecodeSTRPreReg(MCInst &Inst, unsigned Insn,
360                                uint64_t Address, const void *Decoder);
361 static DecodeStatus DecodeVLD1LN(MCInst &Inst, unsigned Insn,
362                                uint64_t Address, const void *Decoder);
363 static DecodeStatus DecodeVLD2LN(MCInst &Inst, unsigned Insn,
364                                uint64_t Address, const void *Decoder);
365 static DecodeStatus DecodeVLD3LN(MCInst &Inst, unsigned Insn,
366                                uint64_t Address, const void *Decoder);
367 static DecodeStatus DecodeVLD4LN(MCInst &Inst, unsigned Insn,
368                                uint64_t Address, const void *Decoder);
369 static DecodeStatus DecodeVST1LN(MCInst &Inst, unsigned Insn,
370                                uint64_t Address, const void *Decoder);
371 static DecodeStatus DecodeVST2LN(MCInst &Inst, unsigned Insn,
372                                uint64_t Address, const void *Decoder);
373 static DecodeStatus DecodeVST3LN(MCInst &Inst, unsigned Insn,
374                                uint64_t Address, const void *Decoder);
375 static DecodeStatus DecodeVST4LN(MCInst &Inst, unsigned Insn,
376                                uint64_t Address, const void *Decoder);
377 static DecodeStatus DecodeVMOVSRR(MCInst &Inst, unsigned Insn,
378                                uint64_t Address, const void *Decoder);
379 static DecodeStatus DecodeVMOVRRS(MCInst &Inst, unsigned Insn,
380                                uint64_t Address, const void *Decoder);
381 static DecodeStatus DecodeSwap(MCInst &Inst, unsigned Insn,
382                                uint64_t Address, const void *Decoder);
383 static DecodeStatus DecodeVCVTD(MCInst &Inst, unsigned Insn,
384                                 uint64_t Address, const void *Decoder);
385 static DecodeStatus DecodeVCVTQ(MCInst &Inst, unsigned Insn,
386                                 uint64_t Address, const void *Decoder);
387 static DecodeStatus DecodeVCVTImmOperand(MCInst &Inst, unsigned Insn,
388                                          uint64_t Address, const void *Decoder);
389 static DecodeStatus DecodeNEONComplexLane64Instruction(MCInst &Inst,
390                                                        unsigned Val,
391                                                        uint64_t Address,
392                                                        const void *Decoder);
393 
394 static DecodeStatus DecodeThumbAddSpecialReg(MCInst &Inst, uint16_t Insn,
395                                uint64_t Address, const void *Decoder);
396 static DecodeStatus DecodeThumbBROperand(MCInst &Inst, unsigned Val,
397                                uint64_t Address, const void *Decoder);
398 static DecodeStatus DecodeT2BROperand(MCInst &Inst, unsigned Val,
399                                uint64_t Address, const void *Decoder);
400 static DecodeStatus DecodeThumbCmpBROperand(MCInst &Inst, unsigned Val,
401                                uint64_t Address, const void *Decoder);
402 static DecodeStatus DecodeThumbAddrModeRR(MCInst &Inst, unsigned Val,
403                                uint64_t Address, const void *Decoder);
404 static DecodeStatus DecodeThumbAddrModeIS(MCInst &Inst, unsigned Val,
405                                uint64_t Address, const void *Decoder);
406 static DecodeStatus DecodeThumbAddrModePC(MCInst &Inst, unsigned Val,
407                                uint64_t Address, const void *Decoder);
408 static DecodeStatus DecodeThumbAddrModeSP(MCInst &Inst, unsigned Val,
409                                uint64_t Address, const void *Decoder);
410 static DecodeStatus DecodeT2AddrModeSOReg(MCInst &Inst, unsigned Val,
411                                uint64_t Address, const void *Decoder);
412 static DecodeStatus DecodeT2LoadShift(MCInst &Inst, unsigned Val,
413                                uint64_t Address, const void *Decoder);
414 static DecodeStatus DecodeT2LoadImm8(MCInst &Inst, unsigned Insn,
415                                uint64_t Address, const void* Decoder);
416 static DecodeStatus DecodeT2LoadImm12(MCInst &Inst, unsigned Insn,
417                                uint64_t Address, const void* Decoder);
418 static DecodeStatus DecodeT2LoadT(MCInst &Inst, unsigned Insn,
419                                uint64_t Address, const void* Decoder);
420 static DecodeStatus DecodeT2LoadLabel(MCInst &Inst, unsigned Insn,
421                                uint64_t Address, const void* Decoder);
422 static DecodeStatus DecodeT2Imm8S4(MCInst &Inst, unsigned Val,
423                                uint64_t Address, const void *Decoder);
424 static DecodeStatus DecodeT2Imm7S4(MCInst &Inst, unsigned Val,
425                                uint64_t Address, const void *Decoder);
426 static DecodeStatus DecodeT2AddrModeImm8s4(MCInst &Inst, unsigned Val,
427                                uint64_t Address, const void *Decoder);
428 static DecodeStatus DecodeT2AddrModeImm7s4(MCInst &Inst, unsigned Val,
429                                            uint64_t Address,
430                                            const void *Decoder);
431 static DecodeStatus DecodeT2AddrModeImm0_1020s4(MCInst &Inst,unsigned Val,
432                                uint64_t Address, const void *Decoder);
433 static DecodeStatus DecodeT2Imm8(MCInst &Inst, unsigned Val,
434                                uint64_t Address, const void *Decoder);
435 template<int shift>
436 static DecodeStatus DecodeT2Imm7(MCInst &Inst, unsigned Val,
437                                uint64_t Address, const void *Decoder);
438 static DecodeStatus DecodeT2AddrModeImm8(MCInst &Inst, unsigned Val,
439                                uint64_t Address, const void *Decoder);
440 template<int shift>
441 static DecodeStatus DecodeTAddrModeImm7(MCInst &Inst, unsigned Val,
442                                uint64_t Address, const void *Decoder);
443 template<int shift, int WriteBack>
444 static DecodeStatus DecodeT2AddrModeImm7(MCInst &Inst, unsigned Val,
445                                uint64_t Address, const void *Decoder);
446 static DecodeStatus DecodeThumbAddSPImm(MCInst &Inst, uint16_t Val,
447                                uint64_t Address, const void *Decoder);
448 static DecodeStatus DecodeThumbAddSPReg(MCInst &Inst, uint16_t Insn,
449                                 uint64_t Address, const void *Decoder);
450 static DecodeStatus DecodeThumbCPS(MCInst &Inst, uint16_t Insn,
451                                 uint64_t Address, const void *Decoder);
452 static DecodeStatus DecodeQADDInstruction(MCInst &Inst, unsigned Insn,
453                                 uint64_t Address, const void *Decoder);
454 static DecodeStatus DecodeThumbBLXOffset(MCInst &Inst, unsigned Insn,
455                                 uint64_t Address, const void *Decoder);
456 static DecodeStatus DecodeT2AddrModeImm12(MCInst &Inst, unsigned Val,
457                                 uint64_t Address, const void *Decoder);
458 static DecodeStatus DecodeThumbTableBranch(MCInst &Inst, unsigned Val,
459                                 uint64_t Address, const void *Decoder);
460 static DecodeStatus DecodeThumb2BCCInstruction(MCInst &Inst, unsigned Val,
461                                 uint64_t Address, const void *Decoder);
462 static DecodeStatus DecodeT2SOImm(MCInst &Inst, unsigned Val,
463                                 uint64_t Address, const void *Decoder);
464 static DecodeStatus DecodeThumbBCCTargetOperand(MCInst &Inst,unsigned Val,
465                                 uint64_t Address, const void *Decoder);
466 static DecodeStatus DecodeThumbBLTargetOperand(MCInst &Inst, unsigned Val,
467                                 uint64_t Address, const void *Decoder);
468 static DecodeStatus DecodeIT(MCInst &Inst, unsigned Val,
469                                 uint64_t Address, const void *Decoder);
470 static DecodeStatus DecodeT2LDRDPreInstruction(MCInst &Inst,unsigned Insn,
471                                uint64_t Address, const void *Decoder);
472 static DecodeStatus DecodeT2STRDPreInstruction(MCInst &Inst,unsigned Insn,
473                                uint64_t Address, const void *Decoder);
474 static DecodeStatus DecodeT2Adr(MCInst &Inst, unsigned Val,
475                                 uint64_t Address, const void *Decoder);
476 static DecodeStatus DecodeT2LdStPre(MCInst &Inst, unsigned Val,
477                                 uint64_t Address, const void *Decoder);
478 static DecodeStatus DecodeT2ShifterImmOperand(MCInst &Inst, unsigned Val,
479                                 uint64_t Address, const void *Decoder);
480 
481 static DecodeStatus DecodeLDR(MCInst &Inst, unsigned Val,
482                                 uint64_t Address, const void *Decoder);
483 static DecodeStatus DecoderForMRRC2AndMCRR2(MCInst &Inst, unsigned Val,
484                                             uint64_t Address, const void *Decoder);
485 static DecodeStatus DecodeForVMRSandVMSR(MCInst &Inst, unsigned Val,
486                                          uint64_t Address, const void *Decoder);
487 
488 template <bool isSigned, bool isNeg, bool zeroPermitted, int size>
489 static DecodeStatus DecodeBFLabelOperand(MCInst &Inst, unsigned val,
490                                          uint64_t Address, const void *Decoder);
491 static DecodeStatus DecodeBFAfterTargetOperand(MCInst &Inst, unsigned val,
492                                                uint64_t Address,
493                                                const void *Decoder);
494 static DecodeStatus DecodePredNoALOperand(MCInst &Inst, unsigned Val,
495                                           uint64_t Address,
496                                           const void *Decoder);
497 static DecodeStatus DecodeLOLoop(MCInst &Inst, unsigned Insn, uint64_t Address,
498                                  const void *Decoder);
499 static DecodeStatus DecodeLongShiftOperand(MCInst &Inst, unsigned Val,
500                                            uint64_t Address,
501                                            const void *Decoder);
502 static DecodeStatus DecodeVSCCLRM(MCInst &Inst, unsigned Insn, uint64_t Address,
503                                   const void *Decoder);
504 static DecodeStatus DecodeVPTMaskOperand(MCInst &Inst, unsigned Val,
505                                          uint64_t Address, const void *Decoder);
506 static DecodeStatus DecodeVpredROperand(MCInst &Inst, unsigned Val,
507                                         uint64_t Address, const void *Decoder);
508 static DecodeStatus DecodeRestrictedIPredicateOperand(MCInst &Inst, unsigned Val,
509                                                      uint64_t Address,
510                                                      const void *Decoder);
511 static DecodeStatus DecodeRestrictedSPredicateOperand(MCInst &Inst, unsigned Val,
512                                                      uint64_t Address,
513                                                      const void *Decoder);
514 static DecodeStatus DecodeRestrictedUPredicateOperand(MCInst &Inst, unsigned Val,
515                                                      uint64_t Address,
516                                                      const void *Decoder);
517 static DecodeStatus DecodeRestrictedFPPredicateOperand(MCInst &Inst,
518                                                        unsigned Val,
519                                                        uint64_t Address,
520                                                        const void *Decoder);
521 template<bool Writeback>
522 static DecodeStatus DecodeVSTRVLDR_SYSREG(MCInst &Inst, unsigned Insn,
523                                           uint64_t Address,
524                                           const void *Decoder);
525 template<int shift>
526 static DecodeStatus DecodeMVE_MEM_1_pre(MCInst &Inst, unsigned Val,
527                                         uint64_t Address, const void *Decoder);
528 template<int shift>
529 static DecodeStatus DecodeMVE_MEM_2_pre(MCInst &Inst, unsigned Val,
530                                         uint64_t Address, const void *Decoder);
531 template<int shift>
532 static DecodeStatus DecodeMVE_MEM_3_pre(MCInst &Inst, unsigned Val,
533                                         uint64_t Address, const void *Decoder);
534 template<unsigned MinLog, unsigned MaxLog>
535 static DecodeStatus DecodePowerTwoOperand(MCInst &Inst, unsigned Val,
536                                           uint64_t Address,
537                                           const void *Decoder);
538 template <int shift>
539 static DecodeStatus DecodeExpandedImmOperand(MCInst &Inst, unsigned Val,
540                                              uint64_t Address,
541                                              const void *Decoder);
542 template<unsigned start>
543 static DecodeStatus DecodeMVEPairVectorIndexOperand(MCInst &Inst, unsigned Val,
544                                                     uint64_t Address,
545                                                     const void *Decoder);
546 static DecodeStatus DecodeMVEVMOVQtoDReg(MCInst &Inst, unsigned Insn,
547                                          uint64_t Address,
548                                          const void *Decoder);
549 static DecodeStatus DecodeMVEVMOVDRegtoQ(MCInst &Inst, unsigned Insn,
550                                          uint64_t Address,
551                                          const void *Decoder);
552 static DecodeStatus DecodeMVEVCVTt1fp(MCInst &Inst, unsigned Insn,
553                                       uint64_t Address, const void *Decoder);
554 typedef DecodeStatus OperandDecoder(MCInst &Inst, unsigned Val,
555                                     uint64_t Address, const void *Decoder);
556 template<bool scalar, OperandDecoder predicate_decoder>
557 static DecodeStatus DecodeMVEVCMP(MCInst &Inst, unsigned Insn,
558                                   uint64_t Address, const void *Decoder);
559 static DecodeStatus DecodeMveVCTP(MCInst &Inst, unsigned Insn,
560                                   uint64_t Address, const void *Decoder);
561 static DecodeStatus DecodeMVEVPNOT(MCInst &Inst, unsigned Insn,
562                                    uint64_t Address, const void *Decoder);
563 static DecodeStatus DecodeMVEOverlappingLongShift(MCInst &Inst, unsigned Insn,
564                                                   uint64_t Address,
565                                                   const void *Decoder);
566 #include "ARMGenDisassemblerTables.inc"
567 
568 static MCDisassembler *createARMDisassembler(const Target &T,
569                                              const MCSubtargetInfo &STI,
570                                              MCContext &Ctx) {
571   return new ARMDisassembler(STI, Ctx);
572 }
573 
574 // Post-decoding checks
575 static DecodeStatus checkDecodedInstruction(MCInst &MI, uint64_t &Size,
576                                             uint64_t Address, raw_ostream &CS,
577                                             uint32_t Insn,
578                                             DecodeStatus Result) {
579   switch (MI.getOpcode()) {
580     case ARM::HVC: {
581       // HVC is undefined if condition = 0xf otherwise upredictable
582       // if condition != 0xe
583       uint32_t Cond = (Insn >> 28) & 0xF;
584       if (Cond == 0xF)
585         return MCDisassembler::Fail;
586       if (Cond != 0xE)
587         return MCDisassembler::SoftFail;
588       return Result;
589     }
590     case ARM::t2ADDri:
591     case ARM::t2ADDri12:
592     case ARM::t2ADDrr:
593     case ARM::t2ADDrs:
594     case ARM::t2SUBri:
595     case ARM::t2SUBri12:
596     case ARM::t2SUBrr:
597     case ARM::t2SUBrs:
598       if (MI.getOperand(0).getReg() == ARM::SP &&
599           MI.getOperand(1).getReg() != ARM::SP)
600         return MCDisassembler::SoftFail;
601       return Result;
602     default: return Result;
603   }
604 }
605 
606 DecodeStatus ARMDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
607                                              ArrayRef<uint8_t> Bytes,
608                                              uint64_t Address,
609                                              raw_ostream &CS) const {
610   if (STI.getFeatureBits()[ARM::ModeThumb])
611     return getThumbInstruction(MI, Size, Bytes, Address, CS);
612   return getARMInstruction(MI, Size, Bytes, Address, CS);
613 }
614 
615 DecodeStatus ARMDisassembler::getARMInstruction(MCInst &MI, uint64_t &Size,
616                                                 ArrayRef<uint8_t> Bytes,
617                                                 uint64_t Address,
618                                                 raw_ostream &CS) const {
619   CommentStream = &CS;
620 
621   assert(!STI.getFeatureBits()[ARM::ModeThumb] &&
622          "Asked to disassemble an ARM instruction but Subtarget is in Thumb "
623          "mode!");
624 
625   // We want to read exactly 4 bytes of data.
626   if (Bytes.size() < 4) {
627     Size = 0;
628     return MCDisassembler::Fail;
629   }
630 
631   // Encoded as a small-endian 32-bit word in the stream.
632   uint32_t Insn =
633       (Bytes[3] << 24) | (Bytes[2] << 16) | (Bytes[1] << 8) | (Bytes[0] << 0);
634 
635   // Calling the auto-generated decoder function.
636   DecodeStatus Result =
637       decodeInstruction(DecoderTableARM32, MI, Insn, Address, this, STI);
638   if (Result != MCDisassembler::Fail) {
639     Size = 4;
640     return checkDecodedInstruction(MI, Size, Address, CS, Insn, Result);
641   }
642 
643   struct DecodeTable {
644     const uint8_t *P;
645     bool DecodePred;
646   };
647 
648   const DecodeTable Tables[] = {
649       {DecoderTableVFP32, false},      {DecoderTableVFPV832, false},
650       {DecoderTableNEONData32, true},  {DecoderTableNEONLoadStore32, true},
651       {DecoderTableNEONDup32, true},   {DecoderTablev8NEON32, false},
652       {DecoderTablev8Crypto32, false},
653   };
654 
655   for (auto Table : Tables) {
656     Result = decodeInstruction(Table.P, MI, Insn, Address, this, STI);
657     if (Result != MCDisassembler::Fail) {
658       Size = 4;
659       // Add a fake predicate operand, because we share these instruction
660       // definitions with Thumb2 where these instructions are predicable.
661       if (Table.DecodePred && !DecodePredicateOperand(MI, 0xE, Address, this))
662         return MCDisassembler::Fail;
663       return Result;
664     }
665   }
666 
667   Result =
668       decodeInstruction(DecoderTableCoProc32, MI, Insn, Address, this, STI);
669   if (Result != MCDisassembler::Fail) {
670     Size = 4;
671     return checkDecodedInstruction(MI, Size, Address, CS, Insn, Result);
672   }
673 
674   Size = 4;
675   return MCDisassembler::Fail;
676 }
677 
678 namespace llvm {
679 
680 extern const MCInstrDesc ARMInsts[];
681 
682 } // end namespace llvm
683 
684 /// tryAddingSymbolicOperand - trys to add a symbolic operand in place of the
685 /// immediate Value in the MCInst.  The immediate Value has had any PC
686 /// adjustment made by the caller.  If the instruction is a branch instruction
687 /// then isBranch is true, else false.  If the getOpInfo() function was set as
688 /// part of the setupForSymbolicDisassembly() call then that function is called
689 /// to get any symbolic information at the Address for this instruction.  If
690 /// that returns non-zero then the symbolic information it returns is used to
691 /// create an MCExpr and that is added as an operand to the MCInst.  If
692 /// getOpInfo() returns zero and isBranch is true then a symbol look up for
693 /// Value is done and if a symbol is found an MCExpr is created with that, else
694 /// an MCExpr with Value is created.  This function returns true if it adds an
695 /// operand to the MCInst and false otherwise.
696 static bool tryAddingSymbolicOperand(uint64_t Address, int32_t Value,
697                                      bool isBranch, uint64_t InstSize,
698                                      MCInst &MI, const void *Decoder) {
699   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
700   // FIXME: Does it make sense for value to be negative?
701   return Dis->tryAddingSymbolicOperand(MI, (uint32_t)Value, Address, isBranch,
702                                        /* Offset */ 0, InstSize);
703 }
704 
705 /// tryAddingPcLoadReferenceComment - trys to add a comment as to what is being
706 /// referenced by a load instruction with the base register that is the Pc.
707 /// These can often be values in a literal pool near the Address of the
708 /// instruction.  The Address of the instruction and its immediate Value are
709 /// used as a possible literal pool entry.  The SymbolLookUp call back will
710 /// return the name of a symbol referenced by the literal pool's entry if
711 /// the referenced address is that of a symbol.  Or it will return a pointer to
712 /// a literal 'C' string if the referenced address of the literal pool's entry
713 /// is an address into a section with 'C' string literals.
714 static void tryAddingPcLoadReferenceComment(uint64_t Address, int Value,
715                                             const void *Decoder) {
716   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
717   Dis->tryAddingPcLoadReferenceComment(Value, Address);
718 }
719 
720 // Thumb1 instructions don't have explicit S bits.  Rather, they
721 // implicitly set CPSR.  Since it's not represented in the encoding, the
722 // auto-generated decoder won't inject the CPSR operand.  We need to fix
723 // that as a post-pass.
724 static void AddThumb1SBit(MCInst &MI, bool InITBlock) {
725   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
726   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
727   MCInst::iterator I = MI.begin();
728   for (unsigned i = 0; i < NumOps; ++i, ++I) {
729     if (I == MI.end()) break;
730     if (OpInfo[i].isOptionalDef() && OpInfo[i].RegClass == ARM::CCRRegClassID) {
731       if (i > 0 && OpInfo[i-1].isPredicate()) continue;
732       MI.insert(I, MCOperand::createReg(InITBlock ? 0 : ARM::CPSR));
733       return;
734     }
735   }
736 
737   MI.insert(I, MCOperand::createReg(InITBlock ? 0 : ARM::CPSR));
738 }
739 
740 static bool isVectorPredicable(unsigned Opcode) {
741   const MCOperandInfo *OpInfo = ARMInsts[Opcode].OpInfo;
742   unsigned short NumOps = ARMInsts[Opcode].NumOperands;
743   for (unsigned i = 0; i < NumOps; ++i) {
744     if (ARM::isVpred(OpInfo[i].OperandType))
745       return true;
746   }
747   return false;
748 }
749 
750 // Most Thumb instructions don't have explicit predicates in the
751 // encoding, but rather get their predicates from IT context.  We need
752 // to fix up the predicate operands using this context information as a
753 // post-pass.
754 MCDisassembler::DecodeStatus
755 ARMDisassembler::AddThumbPredicate(MCInst &MI) const {
756   MCDisassembler::DecodeStatus S = Success;
757 
758   const FeatureBitset &FeatureBits = getSubtargetInfo().getFeatureBits();
759 
760   // A few instructions actually have predicates encoded in them.  Don't
761   // try to overwrite it if we're seeing one of those.
762   switch (MI.getOpcode()) {
763     case ARM::tBcc:
764     case ARM::t2Bcc:
765     case ARM::tCBZ:
766     case ARM::tCBNZ:
767     case ARM::tCPS:
768     case ARM::t2CPS3p:
769     case ARM::t2CPS2p:
770     case ARM::t2CPS1p:
771     case ARM::t2CSEL:
772     case ARM::t2CSINC:
773     case ARM::t2CSINV:
774     case ARM::t2CSNEG:
775     case ARM::tMOVSr:
776     case ARM::tSETEND:
777       // Some instructions (mostly conditional branches) are not
778       // allowed in IT blocks.
779       if (ITBlock.instrInITBlock())
780         S = SoftFail;
781       else
782         return Success;
783       break;
784     case ARM::t2HINT:
785       if (MI.getOperand(0).getImm() == 0x10 && (FeatureBits[ARM::FeatureRAS]) != 0)
786         S = SoftFail;
787       break;
788     case ARM::tB:
789     case ARM::t2B:
790     case ARM::t2TBB:
791     case ARM::t2TBH:
792       // Some instructions (mostly unconditional branches) can
793       // only appears at the end of, or outside of, an IT.
794       if (ITBlock.instrInITBlock() && !ITBlock.instrLastInITBlock())
795         S = SoftFail;
796       break;
797     default:
798       break;
799   }
800 
801   // Warn on non-VPT predicable instruction in a VPT block and a VPT
802   // predicable instruction in an IT block
803   if ((!isVectorPredicable(MI.getOpcode()) && VPTBlock.instrInVPTBlock()) ||
804        (isVectorPredicable(MI.getOpcode()) && ITBlock.instrInITBlock()))
805     S = SoftFail;
806 
807   // If we're in an IT/VPT block, base the predicate on that.  Otherwise,
808   // assume a predicate of AL.
809   unsigned CC = ARMCC::AL;
810   unsigned VCC = ARMVCC::None;
811   if (ITBlock.instrInITBlock()) {
812     CC = ITBlock.getITCC();
813     ITBlock.advanceITState();
814   } else if (VPTBlock.instrInVPTBlock()) {
815     VCC = VPTBlock.getVPTPred();
816     VPTBlock.advanceVPTState();
817   }
818 
819   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
820   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
821 
822   MCInst::iterator CCI = MI.begin();
823   for (unsigned i = 0; i < NumOps; ++i, ++CCI) {
824     if (OpInfo[i].isPredicate() || CCI == MI.end()) break;
825   }
826 
827   if (ARMInsts[MI.getOpcode()].isPredicable()) {
828     CCI = MI.insert(CCI, MCOperand::createImm(CC));
829     ++CCI;
830     if (CC == ARMCC::AL)
831       MI.insert(CCI, MCOperand::createReg(0));
832     else
833       MI.insert(CCI, MCOperand::createReg(ARM::CPSR));
834   } else if (CC != ARMCC::AL) {
835     Check(S, SoftFail);
836   }
837 
838   MCInst::iterator VCCI = MI.begin();
839   unsigned VCCPos;
840   for (VCCPos = 0; VCCPos < NumOps; ++VCCPos, ++VCCI) {
841     if (ARM::isVpred(OpInfo[VCCPos].OperandType) || VCCI == MI.end()) break;
842   }
843 
844   if (isVectorPredicable(MI.getOpcode())) {
845     VCCI = MI.insert(VCCI, MCOperand::createImm(VCC));
846     ++VCCI;
847     if (VCC == ARMVCC::None)
848       MI.insert(VCCI, MCOperand::createReg(0));
849     else
850       MI.insert(VCCI, MCOperand::createReg(ARM::P0));
851     if (OpInfo[VCCPos].OperandType == ARM::OPERAND_VPRED_R) {
852       int TiedOp = ARMInsts[MI.getOpcode()].getOperandConstraint(
853         VCCPos + 2, MCOI::TIED_TO);
854       assert(TiedOp >= 0 &&
855              "Inactive register in vpred_r is not tied to an output!");
856       MI.insert(VCCI, MI.getOperand(TiedOp));
857     }
858   } else if (VCC != ARMVCC::None) {
859     Check(S, SoftFail);
860   }
861 
862   return S;
863 }
864 
865 // Thumb VFP instructions are a special case.  Because we share their
866 // encodings between ARM and Thumb modes, and they are predicable in ARM
867 // mode, the auto-generated decoder will give them an (incorrect)
868 // predicate operand.  We need to rewrite these operands based on the IT
869 // context as a post-pass.
870 void ARMDisassembler::UpdateThumbVFPPredicate(
871   DecodeStatus &S, MCInst &MI) const {
872   unsigned CC;
873   CC = ITBlock.getITCC();
874   if (CC == 0xF)
875     CC = ARMCC::AL;
876   if (ITBlock.instrInITBlock())
877     ITBlock.advanceITState();
878   else if (VPTBlock.instrInVPTBlock()) {
879     CC = VPTBlock.getVPTPred();
880     VPTBlock.advanceVPTState();
881   }
882 
883   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
884   MCInst::iterator I = MI.begin();
885   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
886   for (unsigned i = 0; i < NumOps; ++i, ++I) {
887     if (OpInfo[i].isPredicate() ) {
888       if (CC != ARMCC::AL && !ARMInsts[MI.getOpcode()].isPredicable())
889         Check(S, SoftFail);
890       I->setImm(CC);
891       ++I;
892       if (CC == ARMCC::AL)
893         I->setReg(0);
894       else
895         I->setReg(ARM::CPSR);
896       return;
897     }
898   }
899 }
900 
901 DecodeStatus ARMDisassembler::getThumbInstruction(MCInst &MI, uint64_t &Size,
902                                                   ArrayRef<uint8_t> Bytes,
903                                                   uint64_t Address,
904                                                   raw_ostream &CS) const {
905   CommentStream = &CS;
906 
907   assert(STI.getFeatureBits()[ARM::ModeThumb] &&
908          "Asked to disassemble in Thumb mode but Subtarget is in ARM mode!");
909 
910   // We want to read exactly 2 bytes of data.
911   if (Bytes.size() < 2) {
912     Size = 0;
913     return MCDisassembler::Fail;
914   }
915 
916   uint16_t Insn16 = (Bytes[1] << 8) | Bytes[0];
917   DecodeStatus Result =
918       decodeInstruction(DecoderTableThumb16, MI, Insn16, Address, this, STI);
919   if (Result != MCDisassembler::Fail) {
920     Size = 2;
921     Check(Result, AddThumbPredicate(MI));
922     return Result;
923   }
924 
925   Result = decodeInstruction(DecoderTableThumbSBit16, MI, Insn16, Address, this,
926                              STI);
927   if (Result) {
928     Size = 2;
929     bool InITBlock = ITBlock.instrInITBlock();
930     Check(Result, AddThumbPredicate(MI));
931     AddThumb1SBit(MI, InITBlock);
932     return Result;
933   }
934 
935   Result =
936       decodeInstruction(DecoderTableThumb216, MI, Insn16, Address, this, STI);
937   if (Result != MCDisassembler::Fail) {
938     Size = 2;
939 
940     // Nested IT blocks are UNPREDICTABLE.  Must be checked before we add
941     // the Thumb predicate.
942     if (MI.getOpcode() == ARM::t2IT && ITBlock.instrInITBlock())
943       Result = MCDisassembler::SoftFail;
944 
945     Check(Result, AddThumbPredicate(MI));
946 
947     // If we find an IT instruction, we need to parse its condition
948     // code and mask operands so that we can apply them correctly
949     // to the subsequent instructions.
950     if (MI.getOpcode() == ARM::t2IT) {
951       unsigned Firstcond = MI.getOperand(0).getImm();
952       unsigned Mask = MI.getOperand(1).getImm();
953       ITBlock.setITState(Firstcond, Mask);
954 
955       // An IT instruction that would give a 'NV' predicate is unpredictable.
956       if (Firstcond == ARMCC::AL && !isPowerOf2_32(Mask))
957         CS << "unpredictable IT predicate sequence";
958     }
959 
960     return Result;
961   }
962 
963   // We want to read exactly 4 bytes of data.
964   if (Bytes.size() < 4) {
965     Size = 0;
966     return MCDisassembler::Fail;
967   }
968 
969   uint32_t Insn32 =
970       (Bytes[3] << 8) | (Bytes[2] << 0) | (Bytes[1] << 24) | (Bytes[0] << 16);
971 
972   Result =
973       decodeInstruction(DecoderTableMVE32, MI, Insn32, Address, this, STI);
974   if (Result != MCDisassembler::Fail) {
975     Size = 4;
976 
977     // Nested VPT blocks are UNPREDICTABLE. Must be checked before we add
978     // the VPT predicate.
979     if (isVPTOpcode(MI.getOpcode()) && VPTBlock.instrInVPTBlock())
980       Result = MCDisassembler::SoftFail;
981 
982     Check(Result, AddThumbPredicate(MI));
983 
984     if (isVPTOpcode(MI.getOpcode())) {
985       unsigned Mask = MI.getOperand(0).getImm();
986       VPTBlock.setVPTState(Mask);
987     }
988 
989     return Result;
990   }
991 
992   Result =
993       decodeInstruction(DecoderTableThumb32, MI, Insn32, Address, this, STI);
994   if (Result != MCDisassembler::Fail) {
995     Size = 4;
996     bool InITBlock = ITBlock.instrInITBlock();
997     Check(Result, AddThumbPredicate(MI));
998     AddThumb1SBit(MI, InITBlock);
999     return Result;
1000   }
1001 
1002   Result =
1003       decodeInstruction(DecoderTableThumb232, MI, Insn32, Address, this, STI);
1004   if (Result != MCDisassembler::Fail) {
1005     Size = 4;
1006     Check(Result, AddThumbPredicate(MI));
1007     return checkDecodedInstruction(MI, Size, Address, CS, Insn32, Result);
1008   }
1009 
1010   if (fieldFromInstruction(Insn32, 28, 4) == 0xE) {
1011     Result =
1012         decodeInstruction(DecoderTableVFP32, MI, Insn32, Address, this, STI);
1013     if (Result != MCDisassembler::Fail) {
1014       Size = 4;
1015       UpdateThumbVFPPredicate(Result, MI);
1016       return Result;
1017     }
1018   }
1019 
1020   Result =
1021       decodeInstruction(DecoderTableVFPV832, MI, Insn32, Address, this, STI);
1022   if (Result != MCDisassembler::Fail) {
1023     Size = 4;
1024     return Result;
1025   }
1026 
1027   if (fieldFromInstruction(Insn32, 28, 4) == 0xE) {
1028     Result = decodeInstruction(DecoderTableNEONDup32, MI, Insn32, Address, this,
1029                                STI);
1030     if (Result != MCDisassembler::Fail) {
1031       Size = 4;
1032       Check(Result, AddThumbPredicate(MI));
1033       return Result;
1034     }
1035   }
1036 
1037   if (fieldFromInstruction(Insn32, 24, 8) == 0xF9) {
1038     uint32_t NEONLdStInsn = Insn32;
1039     NEONLdStInsn &= 0xF0FFFFFF;
1040     NEONLdStInsn |= 0x04000000;
1041     Result = decodeInstruction(DecoderTableNEONLoadStore32, MI, NEONLdStInsn,
1042                                Address, this, STI);
1043     if (Result != MCDisassembler::Fail) {
1044       Size = 4;
1045       Check(Result, AddThumbPredicate(MI));
1046       return Result;
1047     }
1048   }
1049 
1050   if (fieldFromInstruction(Insn32, 24, 4) == 0xF) {
1051     uint32_t NEONDataInsn = Insn32;
1052     NEONDataInsn &= 0xF0FFFFFF; // Clear bits 27-24
1053     NEONDataInsn |= (NEONDataInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
1054     NEONDataInsn |= 0x12000000; // Set bits 28 and 25
1055     Result = decodeInstruction(DecoderTableNEONData32, MI, NEONDataInsn,
1056                                Address, this, STI);
1057     if (Result != MCDisassembler::Fail) {
1058       Size = 4;
1059       Check(Result, AddThumbPredicate(MI));
1060       return Result;
1061     }
1062 
1063     uint32_t NEONCryptoInsn = Insn32;
1064     NEONCryptoInsn &= 0xF0FFFFFF; // Clear bits 27-24
1065     NEONCryptoInsn |= (NEONCryptoInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
1066     NEONCryptoInsn |= 0x12000000; // Set bits 28 and 25
1067     Result = decodeInstruction(DecoderTablev8Crypto32, MI, NEONCryptoInsn,
1068                                Address, this, STI);
1069     if (Result != MCDisassembler::Fail) {
1070       Size = 4;
1071       return Result;
1072     }
1073 
1074     uint32_t NEONv8Insn = Insn32;
1075     NEONv8Insn &= 0xF3FFFFFF; // Clear bits 27-26
1076     Result = decodeInstruction(DecoderTablev8NEON32, MI, NEONv8Insn, Address,
1077                                this, STI);
1078     if (Result != MCDisassembler::Fail) {
1079       Size = 4;
1080       return Result;
1081     }
1082   }
1083 
1084   Result =
1085       decodeInstruction(DecoderTableThumb2CoProc32, MI, Insn32, Address, this, STI);
1086   if (Result != MCDisassembler::Fail) {
1087     Size = 4;
1088     Check(Result, AddThumbPredicate(MI));
1089     return Result;
1090   }
1091 
1092   Size = 0;
1093   return MCDisassembler::Fail;
1094 }
1095 
1096 extern "C" void LLVMInitializeARMDisassembler() {
1097   TargetRegistry::RegisterMCDisassembler(getTheARMLETarget(),
1098                                          createARMDisassembler);
1099   TargetRegistry::RegisterMCDisassembler(getTheARMBETarget(),
1100                                          createARMDisassembler);
1101   TargetRegistry::RegisterMCDisassembler(getTheThumbLETarget(),
1102                                          createARMDisassembler);
1103   TargetRegistry::RegisterMCDisassembler(getTheThumbBETarget(),
1104                                          createARMDisassembler);
1105 }
1106 
1107 static const uint16_t GPRDecoderTable[] = {
1108   ARM::R0, ARM::R1, ARM::R2, ARM::R3,
1109   ARM::R4, ARM::R5, ARM::R6, ARM::R7,
1110   ARM::R8, ARM::R9, ARM::R10, ARM::R11,
1111   ARM::R12, ARM::SP, ARM::LR, ARM::PC
1112 };
1113 
1114 static const uint16_t CLRMGPRDecoderTable[] = {
1115   ARM::R0, ARM::R1, ARM::R2, ARM::R3,
1116   ARM::R4, ARM::R5, ARM::R6, ARM::R7,
1117   ARM::R8, ARM::R9, ARM::R10, ARM::R11,
1118   ARM::R12, 0, ARM::LR, ARM::APSR
1119 };
1120 
1121 static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1122                                    uint64_t Address, const void *Decoder) {
1123   if (RegNo > 15)
1124     return MCDisassembler::Fail;
1125 
1126   unsigned Register = GPRDecoderTable[RegNo];
1127   Inst.addOperand(MCOperand::createReg(Register));
1128   return MCDisassembler::Success;
1129 }
1130 
1131 static DecodeStatus DecodeCLRMGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1132                                                uint64_t Address,
1133                                                const void *Decoder) {
1134   if (RegNo > 15)
1135     return MCDisassembler::Fail;
1136 
1137   unsigned Register = CLRMGPRDecoderTable[RegNo];
1138   if (Register == 0)
1139     return MCDisassembler::Fail;
1140 
1141   Inst.addOperand(MCOperand::createReg(Register));
1142   return MCDisassembler::Success;
1143 }
1144 
1145 static DecodeStatus
1146 DecodeGPRnopcRegisterClass(MCInst &Inst, unsigned RegNo,
1147                            uint64_t Address, const void *Decoder) {
1148   DecodeStatus S = MCDisassembler::Success;
1149 
1150   if (RegNo == 15)
1151     S = MCDisassembler::SoftFail;
1152 
1153   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1154 
1155   return S;
1156 }
1157 
1158 static DecodeStatus
1159 DecodeGPRwithAPSRRegisterClass(MCInst &Inst, unsigned RegNo,
1160                                uint64_t Address, const void *Decoder) {
1161   DecodeStatus S = MCDisassembler::Success;
1162 
1163   if (RegNo == 15)
1164   {
1165     Inst.addOperand(MCOperand::createReg(ARM::APSR_NZCV));
1166     return MCDisassembler::Success;
1167   }
1168 
1169   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1170   return S;
1171 }
1172 
1173 static DecodeStatus
1174 DecodeGPRwithZRRegisterClass(MCInst &Inst, unsigned RegNo,
1175                              uint64_t Address, const void *Decoder) {
1176   DecodeStatus S = MCDisassembler::Success;
1177 
1178   if (RegNo == 15)
1179   {
1180     Inst.addOperand(MCOperand::createReg(ARM::ZR));
1181     return MCDisassembler::Success;
1182   }
1183 
1184   if (RegNo == 13)
1185     Check(S, MCDisassembler::SoftFail);
1186 
1187   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1188   return S;
1189 }
1190 
1191 static DecodeStatus
1192 DecodeGPRwithZRnospRegisterClass(MCInst &Inst, unsigned RegNo,
1193                                  uint64_t Address, const void *Decoder) {
1194   DecodeStatus S = MCDisassembler::Success;
1195   if (RegNo == 13)
1196     return MCDisassembler::Fail;
1197   Check(S, DecodeGPRwithZRRegisterClass(Inst, RegNo, Address, Decoder));
1198   return S;
1199 }
1200 
1201 static DecodeStatus DecodetGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1202                                    uint64_t Address, const void *Decoder) {
1203   if (RegNo > 7)
1204     return MCDisassembler::Fail;
1205   return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
1206 }
1207 
1208 static const uint16_t GPRPairDecoderTable[] = {
1209   ARM::R0_R1, ARM::R2_R3,   ARM::R4_R5,  ARM::R6_R7,
1210   ARM::R8_R9, ARM::R10_R11, ARM::R12_SP
1211 };
1212 
1213 static DecodeStatus DecodeGPRPairRegisterClass(MCInst &Inst, unsigned RegNo,
1214                                    uint64_t Address, const void *Decoder) {
1215   DecodeStatus S = MCDisassembler::Success;
1216 
1217   if (RegNo > 13)
1218     return MCDisassembler::Fail;
1219 
1220   if ((RegNo & 1) || RegNo == 0xe)
1221      S = MCDisassembler::SoftFail;
1222 
1223   unsigned RegisterPair = GPRPairDecoderTable[RegNo/2];
1224   Inst.addOperand(MCOperand::createReg(RegisterPair));
1225   return S;
1226 }
1227 
1228 static DecodeStatus DecodetcGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1229                                    uint64_t Address, const void *Decoder) {
1230   unsigned Register = 0;
1231   switch (RegNo) {
1232     case 0:
1233       Register = ARM::R0;
1234       break;
1235     case 1:
1236       Register = ARM::R1;
1237       break;
1238     case 2:
1239       Register = ARM::R2;
1240       break;
1241     case 3:
1242       Register = ARM::R3;
1243       break;
1244     case 9:
1245       Register = ARM::R9;
1246       break;
1247     case 12:
1248       Register = ARM::R12;
1249       break;
1250     default:
1251       return MCDisassembler::Fail;
1252     }
1253 
1254   Inst.addOperand(MCOperand::createReg(Register));
1255   return MCDisassembler::Success;
1256 }
1257 
1258 static DecodeStatus DecoderGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1259                                    uint64_t Address, const void *Decoder) {
1260   DecodeStatus S = MCDisassembler::Success;
1261 
1262   const FeatureBitset &featureBits =
1263     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1264 
1265   if ((RegNo == 13 && !featureBits[ARM::HasV8Ops]) || RegNo == 15)
1266     S = MCDisassembler::SoftFail;
1267 
1268   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1269   return S;
1270 }
1271 
1272 static const uint16_t SPRDecoderTable[] = {
1273      ARM::S0,  ARM::S1,  ARM::S2,  ARM::S3,
1274      ARM::S4,  ARM::S5,  ARM::S6,  ARM::S7,
1275      ARM::S8,  ARM::S9, ARM::S10, ARM::S11,
1276     ARM::S12, ARM::S13, ARM::S14, ARM::S15,
1277     ARM::S16, ARM::S17, ARM::S18, ARM::S19,
1278     ARM::S20, ARM::S21, ARM::S22, ARM::S23,
1279     ARM::S24, ARM::S25, ARM::S26, ARM::S27,
1280     ARM::S28, ARM::S29, ARM::S30, ARM::S31
1281 };
1282 
1283 static DecodeStatus DecodeSPRRegisterClass(MCInst &Inst, unsigned RegNo,
1284                                    uint64_t Address, const void *Decoder) {
1285   if (RegNo > 31)
1286     return MCDisassembler::Fail;
1287 
1288   unsigned Register = SPRDecoderTable[RegNo];
1289   Inst.addOperand(MCOperand::createReg(Register));
1290   return MCDisassembler::Success;
1291 }
1292 
1293 static DecodeStatus DecodeHPRRegisterClass(MCInst &Inst, unsigned RegNo,
1294                                    uint64_t Address, const void *Decoder) {
1295   return DecodeSPRRegisterClass(Inst, RegNo, Address, Decoder);
1296 }
1297 
1298 static const uint16_t DPRDecoderTable[] = {
1299      ARM::D0,  ARM::D1,  ARM::D2,  ARM::D3,
1300      ARM::D4,  ARM::D5,  ARM::D6,  ARM::D7,
1301      ARM::D8,  ARM::D9, ARM::D10, ARM::D11,
1302     ARM::D12, ARM::D13, ARM::D14, ARM::D15,
1303     ARM::D16, ARM::D17, ARM::D18, ARM::D19,
1304     ARM::D20, ARM::D21, ARM::D22, ARM::D23,
1305     ARM::D24, ARM::D25, ARM::D26, ARM::D27,
1306     ARM::D28, ARM::D29, ARM::D30, ARM::D31
1307 };
1308 
1309 static DecodeStatus DecodeDPRRegisterClass(MCInst &Inst, unsigned RegNo,
1310                                    uint64_t Address, const void *Decoder) {
1311   const FeatureBitset &featureBits =
1312     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1313 
1314   bool hasD32 = featureBits[ARM::FeatureD32];
1315 
1316   if (RegNo > 31 || (!hasD32 && RegNo > 15))
1317     return MCDisassembler::Fail;
1318 
1319   unsigned Register = DPRDecoderTable[RegNo];
1320   Inst.addOperand(MCOperand::createReg(Register));
1321   return MCDisassembler::Success;
1322 }
1323 
1324 static DecodeStatus DecodeDPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
1325                                    uint64_t Address, const void *Decoder) {
1326   if (RegNo > 7)
1327     return MCDisassembler::Fail;
1328   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
1329 }
1330 
1331 static DecodeStatus DecodeSPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
1332                                    uint64_t Address, const void *Decoder) {
1333   if (RegNo > 15)
1334     return MCDisassembler::Fail;
1335   return DecodeSPRRegisterClass(Inst, RegNo, Address, Decoder);
1336 }
1337 
1338 static DecodeStatus
1339 DecodeDPR_VFP2RegisterClass(MCInst &Inst, unsigned RegNo,
1340                             uint64_t Address, const void *Decoder) {
1341   if (RegNo > 15)
1342     return MCDisassembler::Fail;
1343   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
1344 }
1345 
1346 static const uint16_t QPRDecoderTable[] = {
1347      ARM::Q0,  ARM::Q1,  ARM::Q2,  ARM::Q3,
1348      ARM::Q4,  ARM::Q5,  ARM::Q6,  ARM::Q7,
1349      ARM::Q8,  ARM::Q9, ARM::Q10, ARM::Q11,
1350     ARM::Q12, ARM::Q13, ARM::Q14, ARM::Q15
1351 };
1352 
1353 static DecodeStatus DecodeQPRRegisterClass(MCInst &Inst, unsigned RegNo,
1354                                    uint64_t Address, const void *Decoder) {
1355   if (RegNo > 31 || (RegNo & 1) != 0)
1356     return MCDisassembler::Fail;
1357   RegNo >>= 1;
1358 
1359   unsigned Register = QPRDecoderTable[RegNo];
1360   Inst.addOperand(MCOperand::createReg(Register));
1361   return MCDisassembler::Success;
1362 }
1363 
1364 static const uint16_t DPairDecoderTable[] = {
1365   ARM::Q0,  ARM::D1_D2,   ARM::Q1,  ARM::D3_D4,   ARM::Q2,  ARM::D5_D6,
1366   ARM::Q3,  ARM::D7_D8,   ARM::Q4,  ARM::D9_D10,  ARM::Q5,  ARM::D11_D12,
1367   ARM::Q6,  ARM::D13_D14, ARM::Q7,  ARM::D15_D16, ARM::Q8,  ARM::D17_D18,
1368   ARM::Q9,  ARM::D19_D20, ARM::Q10, ARM::D21_D22, ARM::Q11, ARM::D23_D24,
1369   ARM::Q12, ARM::D25_D26, ARM::Q13, ARM::D27_D28, ARM::Q14, ARM::D29_D30,
1370   ARM::Q15
1371 };
1372 
1373 static DecodeStatus DecodeDPairRegisterClass(MCInst &Inst, unsigned RegNo,
1374                                    uint64_t Address, const void *Decoder) {
1375   if (RegNo > 30)
1376     return MCDisassembler::Fail;
1377 
1378   unsigned Register = DPairDecoderTable[RegNo];
1379   Inst.addOperand(MCOperand::createReg(Register));
1380   return MCDisassembler::Success;
1381 }
1382 
1383 static const uint16_t DPairSpacedDecoderTable[] = {
1384   ARM::D0_D2,   ARM::D1_D3,   ARM::D2_D4,   ARM::D3_D5,
1385   ARM::D4_D6,   ARM::D5_D7,   ARM::D6_D8,   ARM::D7_D9,
1386   ARM::D8_D10,  ARM::D9_D11,  ARM::D10_D12, ARM::D11_D13,
1387   ARM::D12_D14, ARM::D13_D15, ARM::D14_D16, ARM::D15_D17,
1388   ARM::D16_D18, ARM::D17_D19, ARM::D18_D20, ARM::D19_D21,
1389   ARM::D20_D22, ARM::D21_D23, ARM::D22_D24, ARM::D23_D25,
1390   ARM::D24_D26, ARM::D25_D27, ARM::D26_D28, ARM::D27_D29,
1391   ARM::D28_D30, ARM::D29_D31
1392 };
1393 
1394 static DecodeStatus DecodeDPairSpacedRegisterClass(MCInst &Inst,
1395                                                    unsigned RegNo,
1396                                                    uint64_t Address,
1397                                                    const void *Decoder) {
1398   if (RegNo > 29)
1399     return MCDisassembler::Fail;
1400 
1401   unsigned Register = DPairSpacedDecoderTable[RegNo];
1402   Inst.addOperand(MCOperand::createReg(Register));
1403   return MCDisassembler::Success;
1404 }
1405 
1406 static DecodeStatus DecodePredicateOperand(MCInst &Inst, unsigned Val,
1407                                uint64_t Address, const void *Decoder) {
1408   DecodeStatus S = MCDisassembler::Success;
1409   if (Val == 0xF) return MCDisassembler::Fail;
1410   // AL predicate is not allowed on Thumb1 branches.
1411   if (Inst.getOpcode() == ARM::tBcc && Val == 0xE)
1412     return MCDisassembler::Fail;
1413   if (Val != ARMCC::AL && !ARMInsts[Inst.getOpcode()].isPredicable())
1414     Check(S, MCDisassembler::SoftFail);
1415   Inst.addOperand(MCOperand::createImm(Val));
1416   if (Val == ARMCC::AL) {
1417     Inst.addOperand(MCOperand::createReg(0));
1418   } else
1419     Inst.addOperand(MCOperand::createReg(ARM::CPSR));
1420   return S;
1421 }
1422 
1423 static DecodeStatus DecodeCCOutOperand(MCInst &Inst, unsigned Val,
1424                                uint64_t Address, const void *Decoder) {
1425   if (Val)
1426     Inst.addOperand(MCOperand::createReg(ARM::CPSR));
1427   else
1428     Inst.addOperand(MCOperand::createReg(0));
1429   return MCDisassembler::Success;
1430 }
1431 
1432 static DecodeStatus DecodeSORegImmOperand(MCInst &Inst, unsigned Val,
1433                                uint64_t Address, const void *Decoder) {
1434   DecodeStatus S = MCDisassembler::Success;
1435 
1436   unsigned Rm = fieldFromInstruction(Val, 0, 4);
1437   unsigned type = fieldFromInstruction(Val, 5, 2);
1438   unsigned imm = fieldFromInstruction(Val, 7, 5);
1439 
1440   // Register-immediate
1441   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
1442     return MCDisassembler::Fail;
1443 
1444   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1445   switch (type) {
1446     case 0:
1447       Shift = ARM_AM::lsl;
1448       break;
1449     case 1:
1450       Shift = ARM_AM::lsr;
1451       break;
1452     case 2:
1453       Shift = ARM_AM::asr;
1454       break;
1455     case 3:
1456       Shift = ARM_AM::ror;
1457       break;
1458   }
1459 
1460   if (Shift == ARM_AM::ror && imm == 0)
1461     Shift = ARM_AM::rrx;
1462 
1463   unsigned Op = Shift | (imm << 3);
1464   Inst.addOperand(MCOperand::createImm(Op));
1465 
1466   return S;
1467 }
1468 
1469 static DecodeStatus DecodeSORegRegOperand(MCInst &Inst, unsigned Val,
1470                                uint64_t Address, const void *Decoder) {
1471   DecodeStatus S = MCDisassembler::Success;
1472 
1473   unsigned Rm = fieldFromInstruction(Val, 0, 4);
1474   unsigned type = fieldFromInstruction(Val, 5, 2);
1475   unsigned Rs = fieldFromInstruction(Val, 8, 4);
1476 
1477   // Register-register
1478   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1479     return MCDisassembler::Fail;
1480   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rs, Address, Decoder)))
1481     return MCDisassembler::Fail;
1482 
1483   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1484   switch (type) {
1485     case 0:
1486       Shift = ARM_AM::lsl;
1487       break;
1488     case 1:
1489       Shift = ARM_AM::lsr;
1490       break;
1491     case 2:
1492       Shift = ARM_AM::asr;
1493       break;
1494     case 3:
1495       Shift = ARM_AM::ror;
1496       break;
1497   }
1498 
1499   Inst.addOperand(MCOperand::createImm(Shift));
1500 
1501   return S;
1502 }
1503 
1504 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Val,
1505                                  uint64_t Address, const void *Decoder) {
1506   DecodeStatus S = MCDisassembler::Success;
1507 
1508   bool NeedDisjointWriteback = false;
1509   unsigned WritebackReg = 0;
1510   bool CLRM = false;
1511   switch (Inst.getOpcode()) {
1512   default:
1513     break;
1514   case ARM::LDMIA_UPD:
1515   case ARM::LDMDB_UPD:
1516   case ARM::LDMIB_UPD:
1517   case ARM::LDMDA_UPD:
1518   case ARM::t2LDMIA_UPD:
1519   case ARM::t2LDMDB_UPD:
1520   case ARM::t2STMIA_UPD:
1521   case ARM::t2STMDB_UPD:
1522     NeedDisjointWriteback = true;
1523     WritebackReg = Inst.getOperand(0).getReg();
1524     break;
1525   case ARM::t2CLRM:
1526     CLRM = true;
1527     break;
1528   }
1529 
1530   // Empty register lists are not allowed.
1531   if (Val == 0) return MCDisassembler::Fail;
1532   for (unsigned i = 0; i < 16; ++i) {
1533     if (Val & (1 << i)) {
1534       if (CLRM) {
1535         if (!Check(S, DecodeCLRMGPRRegisterClass(Inst, i, Address, Decoder))) {
1536           return MCDisassembler::Fail;
1537         }
1538       } else {
1539         if (!Check(S, DecodeGPRRegisterClass(Inst, i, Address, Decoder)))
1540           return MCDisassembler::Fail;
1541         // Writeback not allowed if Rn is in the target list.
1542         if (NeedDisjointWriteback && WritebackReg == Inst.end()[-1].getReg())
1543           Check(S, MCDisassembler::SoftFail);
1544       }
1545     }
1546   }
1547 
1548   return S;
1549 }
1550 
1551 static DecodeStatus DecodeSPRRegListOperand(MCInst &Inst, unsigned Val,
1552                                  uint64_t Address, const void *Decoder) {
1553   DecodeStatus S = MCDisassembler::Success;
1554 
1555   unsigned Vd = fieldFromInstruction(Val, 8, 5);
1556   unsigned regs = fieldFromInstruction(Val, 0, 8);
1557 
1558   // In case of unpredictable encoding, tweak the operands.
1559   if (regs == 0 || (Vd + regs) > 32) {
1560     regs = Vd + regs > 32 ? 32 - Vd : regs;
1561     regs = std::max( 1u, regs);
1562     S = MCDisassembler::SoftFail;
1563   }
1564 
1565   if (!Check(S, DecodeSPRRegisterClass(Inst, Vd, Address, Decoder)))
1566     return MCDisassembler::Fail;
1567   for (unsigned i = 0; i < (regs - 1); ++i) {
1568     if (!Check(S, DecodeSPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1569       return MCDisassembler::Fail;
1570   }
1571 
1572   return S;
1573 }
1574 
1575 static DecodeStatus DecodeDPRRegListOperand(MCInst &Inst, unsigned Val,
1576                                  uint64_t Address, const void *Decoder) {
1577   DecodeStatus S = MCDisassembler::Success;
1578 
1579   unsigned Vd = fieldFromInstruction(Val, 8, 5);
1580   unsigned regs = fieldFromInstruction(Val, 1, 7);
1581 
1582   // In case of unpredictable encoding, tweak the operands.
1583   if (regs == 0 || regs > 16 || (Vd + regs) > 32) {
1584     regs = Vd + regs > 32 ? 32 - Vd : regs;
1585     regs = std::max( 1u, regs);
1586     regs = std::min(16u, regs);
1587     S = MCDisassembler::SoftFail;
1588   }
1589 
1590   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
1591       return MCDisassembler::Fail;
1592   for (unsigned i = 0; i < (regs - 1); ++i) {
1593     if (!Check(S, DecodeDPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1594       return MCDisassembler::Fail;
1595   }
1596 
1597   return S;
1598 }
1599 
1600 static DecodeStatus DecodeBitfieldMaskOperand(MCInst &Inst, unsigned Val,
1601                                       uint64_t Address, const void *Decoder) {
1602   // This operand encodes a mask of contiguous zeros between a specified MSB
1603   // and LSB.  To decode it, we create the mask of all bits MSB-and-lower,
1604   // the mask of all bits LSB-and-lower, and then xor them to create
1605   // the mask of that's all ones on [msb, lsb].  Finally we not it to
1606   // create the final mask.
1607   unsigned msb = fieldFromInstruction(Val, 5, 5);
1608   unsigned lsb = fieldFromInstruction(Val, 0, 5);
1609 
1610   DecodeStatus S = MCDisassembler::Success;
1611   if (lsb > msb) {
1612     Check(S, MCDisassembler::SoftFail);
1613     // The check above will cause the warning for the "potentially undefined
1614     // instruction encoding" but we can't build a bad MCOperand value here
1615     // with a lsb > msb or else printing the MCInst will cause a crash.
1616     lsb = msb;
1617   }
1618 
1619   uint32_t msb_mask = 0xFFFFFFFF;
1620   if (msb != 31) msb_mask = (1U << (msb+1)) - 1;
1621   uint32_t lsb_mask = (1U << lsb) - 1;
1622 
1623   Inst.addOperand(MCOperand::createImm(~(msb_mask ^ lsb_mask)));
1624   return S;
1625 }
1626 
1627 static DecodeStatus DecodeCopMemInstruction(MCInst &Inst, unsigned Insn,
1628                                   uint64_t Address, const void *Decoder) {
1629   DecodeStatus S = MCDisassembler::Success;
1630 
1631   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1632   unsigned CRd = fieldFromInstruction(Insn, 12, 4);
1633   unsigned coproc = fieldFromInstruction(Insn, 8, 4);
1634   unsigned imm = fieldFromInstruction(Insn, 0, 8);
1635   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1636   unsigned U = fieldFromInstruction(Insn, 23, 1);
1637   const FeatureBitset &featureBits =
1638     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1639 
1640   switch (Inst.getOpcode()) {
1641     case ARM::LDC_OFFSET:
1642     case ARM::LDC_PRE:
1643     case ARM::LDC_POST:
1644     case ARM::LDC_OPTION:
1645     case ARM::LDCL_OFFSET:
1646     case ARM::LDCL_PRE:
1647     case ARM::LDCL_POST:
1648     case ARM::LDCL_OPTION:
1649     case ARM::STC_OFFSET:
1650     case ARM::STC_PRE:
1651     case ARM::STC_POST:
1652     case ARM::STC_OPTION:
1653     case ARM::STCL_OFFSET:
1654     case ARM::STCL_PRE:
1655     case ARM::STCL_POST:
1656     case ARM::STCL_OPTION:
1657     case ARM::t2LDC_OFFSET:
1658     case ARM::t2LDC_PRE:
1659     case ARM::t2LDC_POST:
1660     case ARM::t2LDC_OPTION:
1661     case ARM::t2LDCL_OFFSET:
1662     case ARM::t2LDCL_PRE:
1663     case ARM::t2LDCL_POST:
1664     case ARM::t2LDCL_OPTION:
1665     case ARM::t2STC_OFFSET:
1666     case ARM::t2STC_PRE:
1667     case ARM::t2STC_POST:
1668     case ARM::t2STC_OPTION:
1669     case ARM::t2STCL_OFFSET:
1670     case ARM::t2STCL_PRE:
1671     case ARM::t2STCL_POST:
1672     case ARM::t2STCL_OPTION:
1673     case ARM::t2LDC2_OFFSET:
1674     case ARM::t2LDC2L_OFFSET:
1675     case ARM::t2LDC2_PRE:
1676     case ARM::t2LDC2L_PRE:
1677     case ARM::t2STC2_OFFSET:
1678     case ARM::t2STC2L_OFFSET:
1679     case ARM::t2STC2_PRE:
1680     case ARM::t2STC2L_PRE:
1681     case ARM::LDC2_OFFSET:
1682     case ARM::LDC2L_OFFSET:
1683     case ARM::LDC2_PRE:
1684     case ARM::LDC2L_PRE:
1685     case ARM::STC2_OFFSET:
1686     case ARM::STC2L_OFFSET:
1687     case ARM::STC2_PRE:
1688     case ARM::STC2L_PRE:
1689     case ARM::t2LDC2_OPTION:
1690     case ARM::t2STC2_OPTION:
1691     case ARM::t2LDC2_POST:
1692     case ARM::t2LDC2L_POST:
1693     case ARM::t2STC2_POST:
1694     case ARM::t2STC2L_POST:
1695     case ARM::LDC2_POST:
1696     case ARM::LDC2L_POST:
1697     case ARM::STC2_POST:
1698     case ARM::STC2L_POST:
1699       if (coproc == 0xA || coproc == 0xB ||
1700           (featureBits[ARM::HasV8_1MMainlineOps] &&
1701            (coproc == 0x8 || coproc == 0x9 || coproc == 0xA || coproc == 0xB ||
1702             coproc == 0xE || coproc == 0xF)))
1703         return MCDisassembler::Fail;
1704       break;
1705     default:
1706       break;
1707   }
1708 
1709   if (featureBits[ARM::HasV8Ops] && (coproc != 14))
1710     return MCDisassembler::Fail;
1711 
1712   Inst.addOperand(MCOperand::createImm(coproc));
1713   Inst.addOperand(MCOperand::createImm(CRd));
1714   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1715     return MCDisassembler::Fail;
1716 
1717   switch (Inst.getOpcode()) {
1718     case ARM::t2LDC2_OFFSET:
1719     case ARM::t2LDC2L_OFFSET:
1720     case ARM::t2LDC2_PRE:
1721     case ARM::t2LDC2L_PRE:
1722     case ARM::t2STC2_OFFSET:
1723     case ARM::t2STC2L_OFFSET:
1724     case ARM::t2STC2_PRE:
1725     case ARM::t2STC2L_PRE:
1726     case ARM::LDC2_OFFSET:
1727     case ARM::LDC2L_OFFSET:
1728     case ARM::LDC2_PRE:
1729     case ARM::LDC2L_PRE:
1730     case ARM::STC2_OFFSET:
1731     case ARM::STC2L_OFFSET:
1732     case ARM::STC2_PRE:
1733     case ARM::STC2L_PRE:
1734     case ARM::t2LDC_OFFSET:
1735     case ARM::t2LDCL_OFFSET:
1736     case ARM::t2LDC_PRE:
1737     case ARM::t2LDCL_PRE:
1738     case ARM::t2STC_OFFSET:
1739     case ARM::t2STCL_OFFSET:
1740     case ARM::t2STC_PRE:
1741     case ARM::t2STCL_PRE:
1742     case ARM::LDC_OFFSET:
1743     case ARM::LDCL_OFFSET:
1744     case ARM::LDC_PRE:
1745     case ARM::LDCL_PRE:
1746     case ARM::STC_OFFSET:
1747     case ARM::STCL_OFFSET:
1748     case ARM::STC_PRE:
1749     case ARM::STCL_PRE:
1750       imm = ARM_AM::getAM5Opc(U ? ARM_AM::add : ARM_AM::sub, imm);
1751       Inst.addOperand(MCOperand::createImm(imm));
1752       break;
1753     case ARM::t2LDC2_POST:
1754     case ARM::t2LDC2L_POST:
1755     case ARM::t2STC2_POST:
1756     case ARM::t2STC2L_POST:
1757     case ARM::LDC2_POST:
1758     case ARM::LDC2L_POST:
1759     case ARM::STC2_POST:
1760     case ARM::STC2L_POST:
1761     case ARM::t2LDC_POST:
1762     case ARM::t2LDCL_POST:
1763     case ARM::t2STC_POST:
1764     case ARM::t2STCL_POST:
1765     case ARM::LDC_POST:
1766     case ARM::LDCL_POST:
1767     case ARM::STC_POST:
1768     case ARM::STCL_POST:
1769       imm |= U << 8;
1770       LLVM_FALLTHROUGH;
1771     default:
1772       // The 'option' variant doesn't encode 'U' in the immediate since
1773       // the immediate is unsigned [0,255].
1774       Inst.addOperand(MCOperand::createImm(imm));
1775       break;
1776   }
1777 
1778   switch (Inst.getOpcode()) {
1779     case ARM::LDC_OFFSET:
1780     case ARM::LDC_PRE:
1781     case ARM::LDC_POST:
1782     case ARM::LDC_OPTION:
1783     case ARM::LDCL_OFFSET:
1784     case ARM::LDCL_PRE:
1785     case ARM::LDCL_POST:
1786     case ARM::LDCL_OPTION:
1787     case ARM::STC_OFFSET:
1788     case ARM::STC_PRE:
1789     case ARM::STC_POST:
1790     case ARM::STC_OPTION:
1791     case ARM::STCL_OFFSET:
1792     case ARM::STCL_PRE:
1793     case ARM::STCL_POST:
1794     case ARM::STCL_OPTION:
1795       if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1796         return MCDisassembler::Fail;
1797       break;
1798     default:
1799       break;
1800   }
1801 
1802   return S;
1803 }
1804 
1805 static DecodeStatus
1806 DecodeAddrMode2IdxInstruction(MCInst &Inst, unsigned Insn,
1807                               uint64_t Address, const void *Decoder) {
1808   DecodeStatus S = MCDisassembler::Success;
1809 
1810   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1811   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
1812   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
1813   unsigned imm = fieldFromInstruction(Insn, 0, 12);
1814   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1815   unsigned reg = fieldFromInstruction(Insn, 25, 1);
1816   unsigned P = fieldFromInstruction(Insn, 24, 1);
1817   unsigned W = fieldFromInstruction(Insn, 21, 1);
1818 
1819   // On stores, the writeback operand precedes Rt.
1820   switch (Inst.getOpcode()) {
1821     case ARM::STR_POST_IMM:
1822     case ARM::STR_POST_REG:
1823     case ARM::STRB_POST_IMM:
1824     case ARM::STRB_POST_REG:
1825     case ARM::STRT_POST_REG:
1826     case ARM::STRT_POST_IMM:
1827     case ARM::STRBT_POST_REG:
1828     case ARM::STRBT_POST_IMM:
1829       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1830         return MCDisassembler::Fail;
1831       break;
1832     default:
1833       break;
1834   }
1835 
1836   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
1837     return MCDisassembler::Fail;
1838 
1839   // On loads, the writeback operand comes after Rt.
1840   switch (Inst.getOpcode()) {
1841     case ARM::LDR_POST_IMM:
1842     case ARM::LDR_POST_REG:
1843     case ARM::LDRB_POST_IMM:
1844     case ARM::LDRB_POST_REG:
1845     case ARM::LDRBT_POST_REG:
1846     case ARM::LDRBT_POST_IMM:
1847     case ARM::LDRT_POST_REG:
1848     case ARM::LDRT_POST_IMM:
1849       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1850         return MCDisassembler::Fail;
1851       break;
1852     default:
1853       break;
1854   }
1855 
1856   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1857     return MCDisassembler::Fail;
1858 
1859   ARM_AM::AddrOpc Op = ARM_AM::add;
1860   if (!fieldFromInstruction(Insn, 23, 1))
1861     Op = ARM_AM::sub;
1862 
1863   bool writeback = (P == 0) || (W == 1);
1864   unsigned idx_mode = 0;
1865   if (P && writeback)
1866     idx_mode = ARMII::IndexModePre;
1867   else if (!P && writeback)
1868     idx_mode = ARMII::IndexModePost;
1869 
1870   if (writeback && (Rn == 15 || Rn == Rt))
1871     S = MCDisassembler::SoftFail; // UNPREDICTABLE
1872 
1873   if (reg) {
1874     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1875       return MCDisassembler::Fail;
1876     ARM_AM::ShiftOpc Opc = ARM_AM::lsl;
1877     switch( fieldFromInstruction(Insn, 5, 2)) {
1878       case 0:
1879         Opc = ARM_AM::lsl;
1880         break;
1881       case 1:
1882         Opc = ARM_AM::lsr;
1883         break;
1884       case 2:
1885         Opc = ARM_AM::asr;
1886         break;
1887       case 3:
1888         Opc = ARM_AM::ror;
1889         break;
1890       default:
1891         return MCDisassembler::Fail;
1892     }
1893     unsigned amt = fieldFromInstruction(Insn, 7, 5);
1894     if (Opc == ARM_AM::ror && amt == 0)
1895       Opc = ARM_AM::rrx;
1896     unsigned imm = ARM_AM::getAM2Opc(Op, amt, Opc, idx_mode);
1897 
1898     Inst.addOperand(MCOperand::createImm(imm));
1899   } else {
1900     Inst.addOperand(MCOperand::createReg(0));
1901     unsigned tmp = ARM_AM::getAM2Opc(Op, imm, ARM_AM::lsl, idx_mode);
1902     Inst.addOperand(MCOperand::createImm(tmp));
1903   }
1904 
1905   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1906     return MCDisassembler::Fail;
1907 
1908   return S;
1909 }
1910 
1911 static DecodeStatus DecodeSORegMemOperand(MCInst &Inst, unsigned Val,
1912                                   uint64_t Address, const void *Decoder) {
1913   DecodeStatus S = MCDisassembler::Success;
1914 
1915   unsigned Rn = fieldFromInstruction(Val, 13, 4);
1916   unsigned Rm = fieldFromInstruction(Val,  0, 4);
1917   unsigned type = fieldFromInstruction(Val, 5, 2);
1918   unsigned imm = fieldFromInstruction(Val, 7, 5);
1919   unsigned U = fieldFromInstruction(Val, 12, 1);
1920 
1921   ARM_AM::ShiftOpc ShOp = ARM_AM::lsl;
1922   switch (type) {
1923     case 0:
1924       ShOp = ARM_AM::lsl;
1925       break;
1926     case 1:
1927       ShOp = ARM_AM::lsr;
1928       break;
1929     case 2:
1930       ShOp = ARM_AM::asr;
1931       break;
1932     case 3:
1933       ShOp = ARM_AM::ror;
1934       break;
1935   }
1936 
1937   if (ShOp == ARM_AM::ror && imm == 0)
1938     ShOp = ARM_AM::rrx;
1939 
1940   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1941     return MCDisassembler::Fail;
1942   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1943     return MCDisassembler::Fail;
1944   unsigned shift;
1945   if (U)
1946     shift = ARM_AM::getAM2Opc(ARM_AM::add, imm, ShOp);
1947   else
1948     shift = ARM_AM::getAM2Opc(ARM_AM::sub, imm, ShOp);
1949   Inst.addOperand(MCOperand::createImm(shift));
1950 
1951   return S;
1952 }
1953 
1954 static DecodeStatus
1955 DecodeAddrMode3Instruction(MCInst &Inst, unsigned Insn,
1956                            uint64_t Address, const void *Decoder) {
1957   DecodeStatus S = MCDisassembler::Success;
1958 
1959   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
1960   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1961   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
1962   unsigned type = fieldFromInstruction(Insn, 22, 1);
1963   unsigned imm = fieldFromInstruction(Insn, 8, 4);
1964   unsigned U = ((~fieldFromInstruction(Insn, 23, 1)) & 1) << 8;
1965   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1966   unsigned W = fieldFromInstruction(Insn, 21, 1);
1967   unsigned P = fieldFromInstruction(Insn, 24, 1);
1968   unsigned Rt2 = Rt + 1;
1969 
1970   bool writeback = (W == 1) | (P == 0);
1971 
1972   // For {LD,ST}RD, Rt must be even, else undefined.
1973   switch (Inst.getOpcode()) {
1974     case ARM::STRD:
1975     case ARM::STRD_PRE:
1976     case ARM::STRD_POST:
1977     case ARM::LDRD:
1978     case ARM::LDRD_PRE:
1979     case ARM::LDRD_POST:
1980       if (Rt & 0x1) S = MCDisassembler::SoftFail;
1981       break;
1982     default:
1983       break;
1984   }
1985   switch (Inst.getOpcode()) {
1986     case ARM::STRD:
1987     case ARM::STRD_PRE:
1988     case ARM::STRD_POST:
1989       if (P == 0 && W == 1)
1990         S = MCDisassembler::SoftFail;
1991 
1992       if (writeback && (Rn == 15 || Rn == Rt || Rn == Rt2))
1993         S = MCDisassembler::SoftFail;
1994       if (type && Rm == 15)
1995         S = MCDisassembler::SoftFail;
1996       if (Rt2 == 15)
1997         S = MCDisassembler::SoftFail;
1998       if (!type && fieldFromInstruction(Insn, 8, 4))
1999         S = MCDisassembler::SoftFail;
2000       break;
2001     case ARM::STRH:
2002     case ARM::STRH_PRE:
2003     case ARM::STRH_POST:
2004       if (Rt == 15)
2005         S = MCDisassembler::SoftFail;
2006       if (writeback && (Rn == 15 || Rn == Rt))
2007         S = MCDisassembler::SoftFail;
2008       if (!type && Rm == 15)
2009         S = MCDisassembler::SoftFail;
2010       break;
2011     case ARM::LDRD:
2012     case ARM::LDRD_PRE:
2013     case ARM::LDRD_POST:
2014       if (type && Rn == 15) {
2015         if (Rt2 == 15)
2016           S = MCDisassembler::SoftFail;
2017         break;
2018       }
2019       if (P == 0 && W == 1)
2020         S = MCDisassembler::SoftFail;
2021       if (!type && (Rt2 == 15 || Rm == 15 || Rm == Rt || Rm == Rt2))
2022         S = MCDisassembler::SoftFail;
2023       if (!type && writeback && Rn == 15)
2024         S = MCDisassembler::SoftFail;
2025       if (writeback && (Rn == Rt || Rn == Rt2))
2026         S = MCDisassembler::SoftFail;
2027       break;
2028     case ARM::LDRH:
2029     case ARM::LDRH_PRE:
2030     case ARM::LDRH_POST:
2031       if (type && Rn == 15) {
2032         if (Rt == 15)
2033           S = MCDisassembler::SoftFail;
2034         break;
2035       }
2036       if (Rt == 15)
2037         S = MCDisassembler::SoftFail;
2038       if (!type && Rm == 15)
2039         S = MCDisassembler::SoftFail;
2040       if (!type && writeback && (Rn == 15 || Rn == Rt))
2041         S = MCDisassembler::SoftFail;
2042       break;
2043     case ARM::LDRSH:
2044     case ARM::LDRSH_PRE:
2045     case ARM::LDRSH_POST:
2046     case ARM::LDRSB:
2047     case ARM::LDRSB_PRE:
2048     case ARM::LDRSB_POST:
2049       if (type && Rn == 15) {
2050         if (Rt == 15)
2051           S = MCDisassembler::SoftFail;
2052         break;
2053       }
2054       if (type && (Rt == 15 || (writeback && Rn == Rt)))
2055         S = MCDisassembler::SoftFail;
2056       if (!type && (Rt == 15 || Rm == 15))
2057         S = MCDisassembler::SoftFail;
2058       if (!type && writeback && (Rn == 15 || Rn == Rt))
2059         S = MCDisassembler::SoftFail;
2060       break;
2061     default:
2062       break;
2063   }
2064 
2065   if (writeback) { // Writeback
2066     if (P)
2067       U |= ARMII::IndexModePre << 9;
2068     else
2069       U |= ARMII::IndexModePost << 9;
2070 
2071     // On stores, the writeback operand precedes Rt.
2072     switch (Inst.getOpcode()) {
2073     case ARM::STRD:
2074     case ARM::STRD_PRE:
2075     case ARM::STRD_POST:
2076     case ARM::STRH:
2077     case ARM::STRH_PRE:
2078     case ARM::STRH_POST:
2079       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2080         return MCDisassembler::Fail;
2081       break;
2082     default:
2083       break;
2084     }
2085   }
2086 
2087   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
2088     return MCDisassembler::Fail;
2089   switch (Inst.getOpcode()) {
2090     case ARM::STRD:
2091     case ARM::STRD_PRE:
2092     case ARM::STRD_POST:
2093     case ARM::LDRD:
2094     case ARM::LDRD_PRE:
2095     case ARM::LDRD_POST:
2096       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder)))
2097         return MCDisassembler::Fail;
2098       break;
2099     default:
2100       break;
2101   }
2102 
2103   if (writeback) {
2104     // On loads, the writeback operand comes after Rt.
2105     switch (Inst.getOpcode()) {
2106     case ARM::LDRD:
2107     case ARM::LDRD_PRE:
2108     case ARM::LDRD_POST:
2109     case ARM::LDRH:
2110     case ARM::LDRH_PRE:
2111     case ARM::LDRH_POST:
2112     case ARM::LDRSH:
2113     case ARM::LDRSH_PRE:
2114     case ARM::LDRSH_POST:
2115     case ARM::LDRSB:
2116     case ARM::LDRSB_PRE:
2117     case ARM::LDRSB_POST:
2118     case ARM::LDRHTr:
2119     case ARM::LDRSBTr:
2120       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2121         return MCDisassembler::Fail;
2122       break;
2123     default:
2124       break;
2125     }
2126   }
2127 
2128   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2129     return MCDisassembler::Fail;
2130 
2131   if (type) {
2132     Inst.addOperand(MCOperand::createReg(0));
2133     Inst.addOperand(MCOperand::createImm(U | (imm << 4) | Rm));
2134   } else {
2135     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2136     return MCDisassembler::Fail;
2137     Inst.addOperand(MCOperand::createImm(U));
2138   }
2139 
2140   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2141     return MCDisassembler::Fail;
2142 
2143   return S;
2144 }
2145 
2146 static DecodeStatus DecodeRFEInstruction(MCInst &Inst, unsigned Insn,
2147                                  uint64_t Address, const void *Decoder) {
2148   DecodeStatus S = MCDisassembler::Success;
2149 
2150   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2151   unsigned mode = fieldFromInstruction(Insn, 23, 2);
2152 
2153   switch (mode) {
2154     case 0:
2155       mode = ARM_AM::da;
2156       break;
2157     case 1:
2158       mode = ARM_AM::ia;
2159       break;
2160     case 2:
2161       mode = ARM_AM::db;
2162       break;
2163     case 3:
2164       mode = ARM_AM::ib;
2165       break;
2166   }
2167 
2168   Inst.addOperand(MCOperand::createImm(mode));
2169   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2170     return MCDisassembler::Fail;
2171 
2172   return S;
2173 }
2174 
2175 static DecodeStatus DecodeQADDInstruction(MCInst &Inst, unsigned Insn,
2176                                uint64_t Address, const void *Decoder) {
2177   DecodeStatus S = MCDisassembler::Success;
2178 
2179   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2180   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2181   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2182   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2183 
2184   if (pred == 0xF)
2185     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
2186 
2187   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2188     return MCDisassembler::Fail;
2189   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
2190     return MCDisassembler::Fail;
2191   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
2192     return MCDisassembler::Fail;
2193   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2194     return MCDisassembler::Fail;
2195   return S;
2196 }
2197 
2198 static DecodeStatus DecodeMemMultipleWritebackInstruction(MCInst &Inst,
2199                                   unsigned Insn,
2200                                   uint64_t Address, const void *Decoder) {
2201   DecodeStatus S = MCDisassembler::Success;
2202 
2203   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2204   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2205   unsigned reglist = fieldFromInstruction(Insn, 0, 16);
2206 
2207   if (pred == 0xF) {
2208     // Ambiguous with RFE and SRS
2209     switch (Inst.getOpcode()) {
2210       case ARM::LDMDA:
2211         Inst.setOpcode(ARM::RFEDA);
2212         break;
2213       case ARM::LDMDA_UPD:
2214         Inst.setOpcode(ARM::RFEDA_UPD);
2215         break;
2216       case ARM::LDMDB:
2217         Inst.setOpcode(ARM::RFEDB);
2218         break;
2219       case ARM::LDMDB_UPD:
2220         Inst.setOpcode(ARM::RFEDB_UPD);
2221         break;
2222       case ARM::LDMIA:
2223         Inst.setOpcode(ARM::RFEIA);
2224         break;
2225       case ARM::LDMIA_UPD:
2226         Inst.setOpcode(ARM::RFEIA_UPD);
2227         break;
2228       case ARM::LDMIB:
2229         Inst.setOpcode(ARM::RFEIB);
2230         break;
2231       case ARM::LDMIB_UPD:
2232         Inst.setOpcode(ARM::RFEIB_UPD);
2233         break;
2234       case ARM::STMDA:
2235         Inst.setOpcode(ARM::SRSDA);
2236         break;
2237       case ARM::STMDA_UPD:
2238         Inst.setOpcode(ARM::SRSDA_UPD);
2239         break;
2240       case ARM::STMDB:
2241         Inst.setOpcode(ARM::SRSDB);
2242         break;
2243       case ARM::STMDB_UPD:
2244         Inst.setOpcode(ARM::SRSDB_UPD);
2245         break;
2246       case ARM::STMIA:
2247         Inst.setOpcode(ARM::SRSIA);
2248         break;
2249       case ARM::STMIA_UPD:
2250         Inst.setOpcode(ARM::SRSIA_UPD);
2251         break;
2252       case ARM::STMIB:
2253         Inst.setOpcode(ARM::SRSIB);
2254         break;
2255       case ARM::STMIB_UPD:
2256         Inst.setOpcode(ARM::SRSIB_UPD);
2257         break;
2258       default:
2259         return MCDisassembler::Fail;
2260     }
2261 
2262     // For stores (which become SRS's, the only operand is the mode.
2263     if (fieldFromInstruction(Insn, 20, 1) == 0) {
2264       // Check SRS encoding constraints
2265       if (!(fieldFromInstruction(Insn, 22, 1) == 1 &&
2266             fieldFromInstruction(Insn, 20, 1) == 0))
2267         return MCDisassembler::Fail;
2268 
2269       Inst.addOperand(
2270           MCOperand::createImm(fieldFromInstruction(Insn, 0, 4)));
2271       return S;
2272     }
2273 
2274     return DecodeRFEInstruction(Inst, Insn, Address, Decoder);
2275   }
2276 
2277   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2278     return MCDisassembler::Fail;
2279   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2280     return MCDisassembler::Fail; // Tied
2281   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2282     return MCDisassembler::Fail;
2283   if (!Check(S, DecodeRegListOperand(Inst, reglist, Address, Decoder)))
2284     return MCDisassembler::Fail;
2285 
2286   return S;
2287 }
2288 
2289 // Check for UNPREDICTABLE predicated ESB instruction
2290 static DecodeStatus DecodeHINTInstruction(MCInst &Inst, unsigned Insn,
2291                                  uint64_t Address, const void *Decoder) {
2292   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2293   unsigned imm8 = fieldFromInstruction(Insn, 0, 8);
2294   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
2295   const FeatureBitset &FeatureBits = Dis->getSubtargetInfo().getFeatureBits();
2296 
2297   DecodeStatus S = MCDisassembler::Success;
2298 
2299   Inst.addOperand(MCOperand::createImm(imm8));
2300 
2301   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2302     return MCDisassembler::Fail;
2303 
2304   // ESB is unpredictable if pred != AL. Without the RAS extension, it is a NOP,
2305   // so all predicates should be allowed.
2306   if (imm8 == 0x10 && pred != 0xe && ((FeatureBits[ARM::FeatureRAS]) != 0))
2307     S = MCDisassembler::SoftFail;
2308 
2309   return S;
2310 }
2311 
2312 static DecodeStatus DecodeCPSInstruction(MCInst &Inst, unsigned Insn,
2313                                  uint64_t Address, const void *Decoder) {
2314   unsigned imod = fieldFromInstruction(Insn, 18, 2);
2315   unsigned M = fieldFromInstruction(Insn, 17, 1);
2316   unsigned iflags = fieldFromInstruction(Insn, 6, 3);
2317   unsigned mode = fieldFromInstruction(Insn, 0, 5);
2318 
2319   DecodeStatus S = MCDisassembler::Success;
2320 
2321   // This decoder is called from multiple location that do not check
2322   // the full encoding is valid before they do.
2323   if (fieldFromInstruction(Insn, 5, 1) != 0 ||
2324       fieldFromInstruction(Insn, 16, 1) != 0 ||
2325       fieldFromInstruction(Insn, 20, 8) != 0x10)
2326     return MCDisassembler::Fail;
2327 
2328   // imod == '01' --> UNPREDICTABLE
2329   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
2330   // return failure here.  The '01' imod value is unprintable, so there's
2331   // nothing useful we could do even if we returned UNPREDICTABLE.
2332 
2333   if (imod == 1) return MCDisassembler::Fail;
2334 
2335   if (imod && M) {
2336     Inst.setOpcode(ARM::CPS3p);
2337     Inst.addOperand(MCOperand::createImm(imod));
2338     Inst.addOperand(MCOperand::createImm(iflags));
2339     Inst.addOperand(MCOperand::createImm(mode));
2340   } else if (imod && !M) {
2341     Inst.setOpcode(ARM::CPS2p);
2342     Inst.addOperand(MCOperand::createImm(imod));
2343     Inst.addOperand(MCOperand::createImm(iflags));
2344     if (mode) S = MCDisassembler::SoftFail;
2345   } else if (!imod && M) {
2346     Inst.setOpcode(ARM::CPS1p);
2347     Inst.addOperand(MCOperand::createImm(mode));
2348     if (iflags) S = MCDisassembler::SoftFail;
2349   } else {
2350     // imod == '00' && M == '0' --> UNPREDICTABLE
2351     Inst.setOpcode(ARM::CPS1p);
2352     Inst.addOperand(MCOperand::createImm(mode));
2353     S = MCDisassembler::SoftFail;
2354   }
2355 
2356   return S;
2357 }
2358 
2359 static DecodeStatus DecodeT2CPSInstruction(MCInst &Inst, unsigned Insn,
2360                                  uint64_t Address, const void *Decoder) {
2361   unsigned imod = fieldFromInstruction(Insn, 9, 2);
2362   unsigned M = fieldFromInstruction(Insn, 8, 1);
2363   unsigned iflags = fieldFromInstruction(Insn, 5, 3);
2364   unsigned mode = fieldFromInstruction(Insn, 0, 5);
2365 
2366   DecodeStatus S = MCDisassembler::Success;
2367 
2368   // imod == '01' --> UNPREDICTABLE
2369   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
2370   // return failure here.  The '01' imod value is unprintable, so there's
2371   // nothing useful we could do even if we returned UNPREDICTABLE.
2372 
2373   if (imod == 1) return MCDisassembler::Fail;
2374 
2375   if (imod && M) {
2376     Inst.setOpcode(ARM::t2CPS3p);
2377     Inst.addOperand(MCOperand::createImm(imod));
2378     Inst.addOperand(MCOperand::createImm(iflags));
2379     Inst.addOperand(MCOperand::createImm(mode));
2380   } else if (imod && !M) {
2381     Inst.setOpcode(ARM::t2CPS2p);
2382     Inst.addOperand(MCOperand::createImm(imod));
2383     Inst.addOperand(MCOperand::createImm(iflags));
2384     if (mode) S = MCDisassembler::SoftFail;
2385   } else if (!imod && M) {
2386     Inst.setOpcode(ARM::t2CPS1p);
2387     Inst.addOperand(MCOperand::createImm(mode));
2388     if (iflags) S = MCDisassembler::SoftFail;
2389   } else {
2390     // imod == '00' && M == '0' --> this is a HINT instruction
2391     int imm = fieldFromInstruction(Insn, 0, 8);
2392     // HINT are defined only for immediate in [0..4]
2393     if(imm > 4) return MCDisassembler::Fail;
2394     Inst.setOpcode(ARM::t2HINT);
2395     Inst.addOperand(MCOperand::createImm(imm));
2396   }
2397 
2398   return S;
2399 }
2400 
2401 static DecodeStatus DecodeT2MOVTWInstruction(MCInst &Inst, unsigned Insn,
2402                                  uint64_t Address, const void *Decoder) {
2403   DecodeStatus S = MCDisassembler::Success;
2404 
2405   unsigned Rd = fieldFromInstruction(Insn, 8, 4);
2406   unsigned imm = 0;
2407 
2408   imm |= (fieldFromInstruction(Insn, 0, 8) << 0);
2409   imm |= (fieldFromInstruction(Insn, 12, 3) << 8);
2410   imm |= (fieldFromInstruction(Insn, 16, 4) << 12);
2411   imm |= (fieldFromInstruction(Insn, 26, 1) << 11);
2412 
2413   if (Inst.getOpcode() == ARM::t2MOVTi16)
2414     if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
2415       return MCDisassembler::Fail;
2416   if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
2417     return MCDisassembler::Fail;
2418 
2419   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
2420     Inst.addOperand(MCOperand::createImm(imm));
2421 
2422   return S;
2423 }
2424 
2425 static DecodeStatus DecodeArmMOVTWInstruction(MCInst &Inst, unsigned Insn,
2426                                  uint64_t Address, const void *Decoder) {
2427   DecodeStatus S = MCDisassembler::Success;
2428 
2429   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2430   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2431   unsigned imm = 0;
2432 
2433   imm |= (fieldFromInstruction(Insn, 0, 12) << 0);
2434   imm |= (fieldFromInstruction(Insn, 16, 4) << 12);
2435 
2436   if (Inst.getOpcode() == ARM::MOVTi16)
2437     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2438       return MCDisassembler::Fail;
2439 
2440   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2441     return MCDisassembler::Fail;
2442 
2443   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
2444     Inst.addOperand(MCOperand::createImm(imm));
2445 
2446   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2447     return MCDisassembler::Fail;
2448 
2449   return S;
2450 }
2451 
2452 static DecodeStatus DecodeSMLAInstruction(MCInst &Inst, unsigned Insn,
2453                                  uint64_t Address, const void *Decoder) {
2454   DecodeStatus S = MCDisassembler::Success;
2455 
2456   unsigned Rd = fieldFromInstruction(Insn, 16, 4);
2457   unsigned Rn = fieldFromInstruction(Insn, 0, 4);
2458   unsigned Rm = fieldFromInstruction(Insn, 8, 4);
2459   unsigned Ra = fieldFromInstruction(Insn, 12, 4);
2460   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2461 
2462   if (pred == 0xF)
2463     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
2464 
2465   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2466     return MCDisassembler::Fail;
2467   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
2468     return MCDisassembler::Fail;
2469   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
2470     return MCDisassembler::Fail;
2471   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Ra, Address, Decoder)))
2472     return MCDisassembler::Fail;
2473 
2474   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2475     return MCDisassembler::Fail;
2476 
2477   return S;
2478 }
2479 
2480 static DecodeStatus DecodeTSTInstruction(MCInst &Inst, unsigned Insn,
2481                                   uint64_t Address, const void *Decoder) {
2482   DecodeStatus S = MCDisassembler::Success;
2483 
2484   unsigned Pred = fieldFromInstruction(Insn, 28, 4);
2485   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2486   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2487 
2488   if (Pred == 0xF)
2489     return DecodeSETPANInstruction(Inst, Insn, Address, Decoder);
2490 
2491   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2492     return MCDisassembler::Fail;
2493   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2494     return MCDisassembler::Fail;
2495   if (!Check(S, DecodePredicateOperand(Inst, Pred, Address, Decoder)))
2496     return MCDisassembler::Fail;
2497 
2498   return S;
2499 }
2500 
2501 static DecodeStatus DecodeSETPANInstruction(MCInst &Inst, unsigned Insn,
2502                                   uint64_t Address, const void *Decoder) {
2503   DecodeStatus S = MCDisassembler::Success;
2504 
2505   unsigned Imm = fieldFromInstruction(Insn, 9, 1);
2506 
2507   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
2508   const FeatureBitset &FeatureBits = Dis->getSubtargetInfo().getFeatureBits();
2509 
2510   if (!FeatureBits[ARM::HasV8_1aOps] ||
2511       !FeatureBits[ARM::HasV8Ops])
2512     return MCDisassembler::Fail;
2513 
2514   // Decoder can be called from DecodeTST, which does not check the full
2515   // encoding is valid.
2516   if (fieldFromInstruction(Insn, 20,12) != 0xf11 ||
2517       fieldFromInstruction(Insn, 4,4) != 0)
2518     return MCDisassembler::Fail;
2519   if (fieldFromInstruction(Insn, 10,10) != 0 ||
2520       fieldFromInstruction(Insn, 0,4) != 0)
2521     S = MCDisassembler::SoftFail;
2522 
2523   Inst.setOpcode(ARM::SETPAN);
2524   Inst.addOperand(MCOperand::createImm(Imm));
2525 
2526   return S;
2527 }
2528 
2529 static DecodeStatus DecodeAddrModeImm12Operand(MCInst &Inst, unsigned Val,
2530                            uint64_t Address, const void *Decoder) {
2531   DecodeStatus S = MCDisassembler::Success;
2532 
2533   unsigned add = fieldFromInstruction(Val, 12, 1);
2534   unsigned imm = fieldFromInstruction(Val, 0, 12);
2535   unsigned Rn = fieldFromInstruction(Val, 13, 4);
2536 
2537   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2538     return MCDisassembler::Fail;
2539 
2540   if (!add) imm *= -1;
2541   if (imm == 0 && !add) imm = INT32_MIN;
2542   Inst.addOperand(MCOperand::createImm(imm));
2543   if (Rn == 15)
2544     tryAddingPcLoadReferenceComment(Address, Address + imm + 8, Decoder);
2545 
2546   return S;
2547 }
2548 
2549 static DecodeStatus DecodeAddrMode5Operand(MCInst &Inst, unsigned Val,
2550                                    uint64_t Address, const void *Decoder) {
2551   DecodeStatus S = MCDisassembler::Success;
2552 
2553   unsigned Rn = fieldFromInstruction(Val, 9, 4);
2554   // U == 1 to add imm, 0 to subtract it.
2555   unsigned U = fieldFromInstruction(Val, 8, 1);
2556   unsigned imm = fieldFromInstruction(Val, 0, 8);
2557 
2558   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2559     return MCDisassembler::Fail;
2560 
2561   if (U)
2562     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5Opc(ARM_AM::add, imm)));
2563   else
2564     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5Opc(ARM_AM::sub, imm)));
2565 
2566   return S;
2567 }
2568 
2569 static DecodeStatus DecodeAddrMode5FP16Operand(MCInst &Inst, unsigned Val,
2570                                    uint64_t Address, const void *Decoder) {
2571   DecodeStatus S = MCDisassembler::Success;
2572 
2573   unsigned Rn = fieldFromInstruction(Val, 9, 4);
2574   // U == 1 to add imm, 0 to subtract it.
2575   unsigned U = fieldFromInstruction(Val, 8, 1);
2576   unsigned imm = fieldFromInstruction(Val, 0, 8);
2577 
2578   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2579     return MCDisassembler::Fail;
2580 
2581   if (U)
2582     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5FP16Opc(ARM_AM::add, imm)));
2583   else
2584     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5FP16Opc(ARM_AM::sub, imm)));
2585 
2586   return S;
2587 }
2588 
2589 static DecodeStatus DecodeAddrMode7Operand(MCInst &Inst, unsigned Val,
2590                                    uint64_t Address, const void *Decoder) {
2591   return DecodeGPRRegisterClass(Inst, Val, Address, Decoder);
2592 }
2593 
2594 static DecodeStatus
2595 DecodeT2BInstruction(MCInst &Inst, unsigned Insn,
2596                      uint64_t Address, const void *Decoder) {
2597   DecodeStatus Status = MCDisassembler::Success;
2598 
2599   // Note the J1 and J2 values are from the encoded instruction.  So here
2600   // change them to I1 and I2 values via as documented:
2601   // I1 = NOT(J1 EOR S);
2602   // I2 = NOT(J2 EOR S);
2603   // and build the imm32 with one trailing zero as documented:
2604   // imm32 = SignExtend(S:I1:I2:imm10:imm11:'0', 32);
2605   unsigned S = fieldFromInstruction(Insn, 26, 1);
2606   unsigned J1 = fieldFromInstruction(Insn, 13, 1);
2607   unsigned J2 = fieldFromInstruction(Insn, 11, 1);
2608   unsigned I1 = !(J1 ^ S);
2609   unsigned I2 = !(J2 ^ S);
2610   unsigned imm10 = fieldFromInstruction(Insn, 16, 10);
2611   unsigned imm11 = fieldFromInstruction(Insn, 0, 11);
2612   unsigned tmp = (S << 23) | (I1 << 22) | (I2 << 21) | (imm10 << 11) | imm11;
2613   int imm32 = SignExtend32<25>(tmp << 1);
2614   if (!tryAddingSymbolicOperand(Address, Address + imm32 + 4,
2615                                 true, 4, Inst, Decoder))
2616     Inst.addOperand(MCOperand::createImm(imm32));
2617 
2618   return Status;
2619 }
2620 
2621 static DecodeStatus
2622 DecodeBranchImmInstruction(MCInst &Inst, unsigned Insn,
2623                            uint64_t Address, const void *Decoder) {
2624   DecodeStatus S = MCDisassembler::Success;
2625 
2626   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2627   unsigned imm = fieldFromInstruction(Insn, 0, 24) << 2;
2628 
2629   if (pred == 0xF) {
2630     Inst.setOpcode(ARM::BLXi);
2631     imm |= fieldFromInstruction(Insn, 24, 1) << 1;
2632     if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<26>(imm) + 8,
2633                                   true, 4, Inst, Decoder))
2634     Inst.addOperand(MCOperand::createImm(SignExtend32<26>(imm)));
2635     return S;
2636   }
2637 
2638   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<26>(imm) + 8,
2639                                 true, 4, Inst, Decoder))
2640     Inst.addOperand(MCOperand::createImm(SignExtend32<26>(imm)));
2641   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2642     return MCDisassembler::Fail;
2643 
2644   return S;
2645 }
2646 
2647 static DecodeStatus DecodeAddrMode6Operand(MCInst &Inst, unsigned Val,
2648                                    uint64_t Address, const void *Decoder) {
2649   DecodeStatus S = MCDisassembler::Success;
2650 
2651   unsigned Rm = fieldFromInstruction(Val, 0, 4);
2652   unsigned align = fieldFromInstruction(Val, 4, 2);
2653 
2654   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2655     return MCDisassembler::Fail;
2656   if (!align)
2657     Inst.addOperand(MCOperand::createImm(0));
2658   else
2659     Inst.addOperand(MCOperand::createImm(4 << align));
2660 
2661   return S;
2662 }
2663 
2664 static DecodeStatus DecodeVLDInstruction(MCInst &Inst, unsigned Insn,
2665                                    uint64_t Address, const void *Decoder) {
2666   DecodeStatus S = MCDisassembler::Success;
2667 
2668   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2669   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
2670   unsigned wb = fieldFromInstruction(Insn, 16, 4);
2671   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2672   Rn |= fieldFromInstruction(Insn, 4, 2) << 4;
2673   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2674 
2675   // First output register
2676   switch (Inst.getOpcode()) {
2677   case ARM::VLD1q16: case ARM::VLD1q32: case ARM::VLD1q64: case ARM::VLD1q8:
2678   case ARM::VLD1q16wb_fixed: case ARM::VLD1q16wb_register:
2679   case ARM::VLD1q32wb_fixed: case ARM::VLD1q32wb_register:
2680   case ARM::VLD1q64wb_fixed: case ARM::VLD1q64wb_register:
2681   case ARM::VLD1q8wb_fixed: case ARM::VLD1q8wb_register:
2682   case ARM::VLD2d16: case ARM::VLD2d32: case ARM::VLD2d8:
2683   case ARM::VLD2d16wb_fixed: case ARM::VLD2d16wb_register:
2684   case ARM::VLD2d32wb_fixed: case ARM::VLD2d32wb_register:
2685   case ARM::VLD2d8wb_fixed: case ARM::VLD2d8wb_register:
2686     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
2687       return MCDisassembler::Fail;
2688     break;
2689   case ARM::VLD2b16:
2690   case ARM::VLD2b32:
2691   case ARM::VLD2b8:
2692   case ARM::VLD2b16wb_fixed:
2693   case ARM::VLD2b16wb_register:
2694   case ARM::VLD2b32wb_fixed:
2695   case ARM::VLD2b32wb_register:
2696   case ARM::VLD2b8wb_fixed:
2697   case ARM::VLD2b8wb_register:
2698     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
2699       return MCDisassembler::Fail;
2700     break;
2701   default:
2702     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2703       return MCDisassembler::Fail;
2704   }
2705 
2706   // Second output register
2707   switch (Inst.getOpcode()) {
2708     case ARM::VLD3d8:
2709     case ARM::VLD3d16:
2710     case ARM::VLD3d32:
2711     case ARM::VLD3d8_UPD:
2712     case ARM::VLD3d16_UPD:
2713     case ARM::VLD3d32_UPD:
2714     case ARM::VLD4d8:
2715     case ARM::VLD4d16:
2716     case ARM::VLD4d32:
2717     case ARM::VLD4d8_UPD:
2718     case ARM::VLD4d16_UPD:
2719     case ARM::VLD4d32_UPD:
2720       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
2721         return MCDisassembler::Fail;
2722       break;
2723     case ARM::VLD3q8:
2724     case ARM::VLD3q16:
2725     case ARM::VLD3q32:
2726     case ARM::VLD3q8_UPD:
2727     case ARM::VLD3q16_UPD:
2728     case ARM::VLD3q32_UPD:
2729     case ARM::VLD4q8:
2730     case ARM::VLD4q16:
2731     case ARM::VLD4q32:
2732     case ARM::VLD4q8_UPD:
2733     case ARM::VLD4q16_UPD:
2734     case ARM::VLD4q32_UPD:
2735       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2736         return MCDisassembler::Fail;
2737       break;
2738     default:
2739       break;
2740   }
2741 
2742   // Third output register
2743   switch(Inst.getOpcode()) {
2744     case ARM::VLD3d8:
2745     case ARM::VLD3d16:
2746     case ARM::VLD3d32:
2747     case ARM::VLD3d8_UPD:
2748     case ARM::VLD3d16_UPD:
2749     case ARM::VLD3d32_UPD:
2750     case ARM::VLD4d8:
2751     case ARM::VLD4d16:
2752     case ARM::VLD4d32:
2753     case ARM::VLD4d8_UPD:
2754     case ARM::VLD4d16_UPD:
2755     case ARM::VLD4d32_UPD:
2756       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2757         return MCDisassembler::Fail;
2758       break;
2759     case ARM::VLD3q8:
2760     case ARM::VLD3q16:
2761     case ARM::VLD3q32:
2762     case ARM::VLD3q8_UPD:
2763     case ARM::VLD3q16_UPD:
2764     case ARM::VLD3q32_UPD:
2765     case ARM::VLD4q8:
2766     case ARM::VLD4q16:
2767     case ARM::VLD4q32:
2768     case ARM::VLD4q8_UPD:
2769     case ARM::VLD4q16_UPD:
2770     case ARM::VLD4q32_UPD:
2771       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
2772         return MCDisassembler::Fail;
2773       break;
2774     default:
2775       break;
2776   }
2777 
2778   // Fourth output register
2779   switch (Inst.getOpcode()) {
2780     case ARM::VLD4d8:
2781     case ARM::VLD4d16:
2782     case ARM::VLD4d32:
2783     case ARM::VLD4d8_UPD:
2784     case ARM::VLD4d16_UPD:
2785     case ARM::VLD4d32_UPD:
2786       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
2787         return MCDisassembler::Fail;
2788       break;
2789     case ARM::VLD4q8:
2790     case ARM::VLD4q16:
2791     case ARM::VLD4q32:
2792     case ARM::VLD4q8_UPD:
2793     case ARM::VLD4q16_UPD:
2794     case ARM::VLD4q32_UPD:
2795       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
2796         return MCDisassembler::Fail;
2797       break;
2798     default:
2799       break;
2800   }
2801 
2802   // Writeback operand
2803   switch (Inst.getOpcode()) {
2804     case ARM::VLD1d8wb_fixed:
2805     case ARM::VLD1d16wb_fixed:
2806     case ARM::VLD1d32wb_fixed:
2807     case ARM::VLD1d64wb_fixed:
2808     case ARM::VLD1d8wb_register:
2809     case ARM::VLD1d16wb_register:
2810     case ARM::VLD1d32wb_register:
2811     case ARM::VLD1d64wb_register:
2812     case ARM::VLD1q8wb_fixed:
2813     case ARM::VLD1q16wb_fixed:
2814     case ARM::VLD1q32wb_fixed:
2815     case ARM::VLD1q64wb_fixed:
2816     case ARM::VLD1q8wb_register:
2817     case ARM::VLD1q16wb_register:
2818     case ARM::VLD1q32wb_register:
2819     case ARM::VLD1q64wb_register:
2820     case ARM::VLD1d8Twb_fixed:
2821     case ARM::VLD1d8Twb_register:
2822     case ARM::VLD1d16Twb_fixed:
2823     case ARM::VLD1d16Twb_register:
2824     case ARM::VLD1d32Twb_fixed:
2825     case ARM::VLD1d32Twb_register:
2826     case ARM::VLD1d64Twb_fixed:
2827     case ARM::VLD1d64Twb_register:
2828     case ARM::VLD1d8Qwb_fixed:
2829     case ARM::VLD1d8Qwb_register:
2830     case ARM::VLD1d16Qwb_fixed:
2831     case ARM::VLD1d16Qwb_register:
2832     case ARM::VLD1d32Qwb_fixed:
2833     case ARM::VLD1d32Qwb_register:
2834     case ARM::VLD1d64Qwb_fixed:
2835     case ARM::VLD1d64Qwb_register:
2836     case ARM::VLD2d8wb_fixed:
2837     case ARM::VLD2d16wb_fixed:
2838     case ARM::VLD2d32wb_fixed:
2839     case ARM::VLD2q8wb_fixed:
2840     case ARM::VLD2q16wb_fixed:
2841     case ARM::VLD2q32wb_fixed:
2842     case ARM::VLD2d8wb_register:
2843     case ARM::VLD2d16wb_register:
2844     case ARM::VLD2d32wb_register:
2845     case ARM::VLD2q8wb_register:
2846     case ARM::VLD2q16wb_register:
2847     case ARM::VLD2q32wb_register:
2848     case ARM::VLD2b8wb_fixed:
2849     case ARM::VLD2b16wb_fixed:
2850     case ARM::VLD2b32wb_fixed:
2851     case ARM::VLD2b8wb_register:
2852     case ARM::VLD2b16wb_register:
2853     case ARM::VLD2b32wb_register:
2854       Inst.addOperand(MCOperand::createImm(0));
2855       break;
2856     case ARM::VLD3d8_UPD:
2857     case ARM::VLD3d16_UPD:
2858     case ARM::VLD3d32_UPD:
2859     case ARM::VLD3q8_UPD:
2860     case ARM::VLD3q16_UPD:
2861     case ARM::VLD3q32_UPD:
2862     case ARM::VLD4d8_UPD:
2863     case ARM::VLD4d16_UPD:
2864     case ARM::VLD4d32_UPD:
2865     case ARM::VLD4q8_UPD:
2866     case ARM::VLD4q16_UPD:
2867     case ARM::VLD4q32_UPD:
2868       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
2869         return MCDisassembler::Fail;
2870       break;
2871     default:
2872       break;
2873   }
2874 
2875   // AddrMode6 Base (register+alignment)
2876   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
2877     return MCDisassembler::Fail;
2878 
2879   // AddrMode6 Offset (register)
2880   switch (Inst.getOpcode()) {
2881   default:
2882     // The below have been updated to have explicit am6offset split
2883     // between fixed and register offset. For those instructions not
2884     // yet updated, we need to add an additional reg0 operand for the
2885     // fixed variant.
2886     //
2887     // The fixed offset encodes as Rm == 0xd, so we check for that.
2888     if (Rm == 0xd) {
2889       Inst.addOperand(MCOperand::createReg(0));
2890       break;
2891     }
2892     // Fall through to handle the register offset variant.
2893     LLVM_FALLTHROUGH;
2894   case ARM::VLD1d8wb_fixed:
2895   case ARM::VLD1d16wb_fixed:
2896   case ARM::VLD1d32wb_fixed:
2897   case ARM::VLD1d64wb_fixed:
2898   case ARM::VLD1d8Twb_fixed:
2899   case ARM::VLD1d16Twb_fixed:
2900   case ARM::VLD1d32Twb_fixed:
2901   case ARM::VLD1d64Twb_fixed:
2902   case ARM::VLD1d8Qwb_fixed:
2903   case ARM::VLD1d16Qwb_fixed:
2904   case ARM::VLD1d32Qwb_fixed:
2905   case ARM::VLD1d64Qwb_fixed:
2906   case ARM::VLD1d8wb_register:
2907   case ARM::VLD1d16wb_register:
2908   case ARM::VLD1d32wb_register:
2909   case ARM::VLD1d64wb_register:
2910   case ARM::VLD1q8wb_fixed:
2911   case ARM::VLD1q16wb_fixed:
2912   case ARM::VLD1q32wb_fixed:
2913   case ARM::VLD1q64wb_fixed:
2914   case ARM::VLD1q8wb_register:
2915   case ARM::VLD1q16wb_register:
2916   case ARM::VLD1q32wb_register:
2917   case ARM::VLD1q64wb_register:
2918     // The fixed offset post-increment encodes Rm == 0xd. The no-writeback
2919     // variant encodes Rm == 0xf. Anything else is a register offset post-
2920     // increment and we need to add the register operand to the instruction.
2921     if (Rm != 0xD && Rm != 0xF &&
2922         !Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2923       return MCDisassembler::Fail;
2924     break;
2925   case ARM::VLD2d8wb_fixed:
2926   case ARM::VLD2d16wb_fixed:
2927   case ARM::VLD2d32wb_fixed:
2928   case ARM::VLD2b8wb_fixed:
2929   case ARM::VLD2b16wb_fixed:
2930   case ARM::VLD2b32wb_fixed:
2931   case ARM::VLD2q8wb_fixed:
2932   case ARM::VLD2q16wb_fixed:
2933   case ARM::VLD2q32wb_fixed:
2934     break;
2935   }
2936 
2937   return S;
2938 }
2939 
2940 static DecodeStatus DecodeVLDST1Instruction(MCInst &Inst, unsigned Insn,
2941                                    uint64_t Address, const void *Decoder) {
2942   unsigned type = fieldFromInstruction(Insn, 8, 4);
2943   unsigned align = fieldFromInstruction(Insn, 4, 2);
2944   if (type == 6 && (align & 2)) return MCDisassembler::Fail;
2945   if (type == 7 && (align & 2)) return MCDisassembler::Fail;
2946   if (type == 10 && align == 3) return MCDisassembler::Fail;
2947 
2948   unsigned load = fieldFromInstruction(Insn, 21, 1);
2949   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2950               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2951 }
2952 
2953 static DecodeStatus DecodeVLDST2Instruction(MCInst &Inst, unsigned Insn,
2954                                    uint64_t Address, const void *Decoder) {
2955   unsigned size = fieldFromInstruction(Insn, 6, 2);
2956   if (size == 3) return MCDisassembler::Fail;
2957 
2958   unsigned type = fieldFromInstruction(Insn, 8, 4);
2959   unsigned align = fieldFromInstruction(Insn, 4, 2);
2960   if (type == 8 && align == 3) return MCDisassembler::Fail;
2961   if (type == 9 && align == 3) return MCDisassembler::Fail;
2962 
2963   unsigned load = fieldFromInstruction(Insn, 21, 1);
2964   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2965               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2966 }
2967 
2968 static DecodeStatus DecodeVLDST3Instruction(MCInst &Inst, unsigned Insn,
2969                                    uint64_t Address, const void *Decoder) {
2970   unsigned size = fieldFromInstruction(Insn, 6, 2);
2971   if (size == 3) return MCDisassembler::Fail;
2972 
2973   unsigned align = fieldFromInstruction(Insn, 4, 2);
2974   if (align & 2) return MCDisassembler::Fail;
2975 
2976   unsigned load = fieldFromInstruction(Insn, 21, 1);
2977   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2978               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2979 }
2980 
2981 static DecodeStatus DecodeVLDST4Instruction(MCInst &Inst, unsigned Insn,
2982                                    uint64_t Address, const void *Decoder) {
2983   unsigned size = fieldFromInstruction(Insn, 6, 2);
2984   if (size == 3) return MCDisassembler::Fail;
2985 
2986   unsigned load = fieldFromInstruction(Insn, 21, 1);
2987   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2988               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2989 }
2990 
2991 static DecodeStatus DecodeVSTInstruction(MCInst &Inst, unsigned Insn,
2992                                  uint64_t Address, const void *Decoder) {
2993   DecodeStatus S = MCDisassembler::Success;
2994 
2995   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2996   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
2997   unsigned wb = fieldFromInstruction(Insn, 16, 4);
2998   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2999   Rn |= fieldFromInstruction(Insn, 4, 2) << 4;
3000   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3001 
3002   // Writeback Operand
3003   switch (Inst.getOpcode()) {
3004     case ARM::VST1d8wb_fixed:
3005     case ARM::VST1d16wb_fixed:
3006     case ARM::VST1d32wb_fixed:
3007     case ARM::VST1d64wb_fixed:
3008     case ARM::VST1d8wb_register:
3009     case ARM::VST1d16wb_register:
3010     case ARM::VST1d32wb_register:
3011     case ARM::VST1d64wb_register:
3012     case ARM::VST1q8wb_fixed:
3013     case ARM::VST1q16wb_fixed:
3014     case ARM::VST1q32wb_fixed:
3015     case ARM::VST1q64wb_fixed:
3016     case ARM::VST1q8wb_register:
3017     case ARM::VST1q16wb_register:
3018     case ARM::VST1q32wb_register:
3019     case ARM::VST1q64wb_register:
3020     case ARM::VST1d8Twb_fixed:
3021     case ARM::VST1d16Twb_fixed:
3022     case ARM::VST1d32Twb_fixed:
3023     case ARM::VST1d64Twb_fixed:
3024     case ARM::VST1d8Twb_register:
3025     case ARM::VST1d16Twb_register:
3026     case ARM::VST1d32Twb_register:
3027     case ARM::VST1d64Twb_register:
3028     case ARM::VST1d8Qwb_fixed:
3029     case ARM::VST1d16Qwb_fixed:
3030     case ARM::VST1d32Qwb_fixed:
3031     case ARM::VST1d64Qwb_fixed:
3032     case ARM::VST1d8Qwb_register:
3033     case ARM::VST1d16Qwb_register:
3034     case ARM::VST1d32Qwb_register:
3035     case ARM::VST1d64Qwb_register:
3036     case ARM::VST2d8wb_fixed:
3037     case ARM::VST2d16wb_fixed:
3038     case ARM::VST2d32wb_fixed:
3039     case ARM::VST2d8wb_register:
3040     case ARM::VST2d16wb_register:
3041     case ARM::VST2d32wb_register:
3042     case ARM::VST2q8wb_fixed:
3043     case ARM::VST2q16wb_fixed:
3044     case ARM::VST2q32wb_fixed:
3045     case ARM::VST2q8wb_register:
3046     case ARM::VST2q16wb_register:
3047     case ARM::VST2q32wb_register:
3048     case ARM::VST2b8wb_fixed:
3049     case ARM::VST2b16wb_fixed:
3050     case ARM::VST2b32wb_fixed:
3051     case ARM::VST2b8wb_register:
3052     case ARM::VST2b16wb_register:
3053     case ARM::VST2b32wb_register:
3054       if (Rm == 0xF)
3055         return MCDisassembler::Fail;
3056       Inst.addOperand(MCOperand::createImm(0));
3057       break;
3058     case ARM::VST3d8_UPD:
3059     case ARM::VST3d16_UPD:
3060     case ARM::VST3d32_UPD:
3061     case ARM::VST3q8_UPD:
3062     case ARM::VST3q16_UPD:
3063     case ARM::VST3q32_UPD:
3064     case ARM::VST4d8_UPD:
3065     case ARM::VST4d16_UPD:
3066     case ARM::VST4d32_UPD:
3067     case ARM::VST4q8_UPD:
3068     case ARM::VST4q16_UPD:
3069     case ARM::VST4q32_UPD:
3070       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
3071         return MCDisassembler::Fail;
3072       break;
3073     default:
3074       break;
3075   }
3076 
3077   // AddrMode6 Base (register+alignment)
3078   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
3079     return MCDisassembler::Fail;
3080 
3081   // AddrMode6 Offset (register)
3082   switch (Inst.getOpcode()) {
3083     default:
3084       if (Rm == 0xD)
3085         Inst.addOperand(MCOperand::createReg(0));
3086       else if (Rm != 0xF) {
3087         if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3088           return MCDisassembler::Fail;
3089       }
3090       break;
3091     case ARM::VST1d8wb_fixed:
3092     case ARM::VST1d16wb_fixed:
3093     case ARM::VST1d32wb_fixed:
3094     case ARM::VST1d64wb_fixed:
3095     case ARM::VST1q8wb_fixed:
3096     case ARM::VST1q16wb_fixed:
3097     case ARM::VST1q32wb_fixed:
3098     case ARM::VST1q64wb_fixed:
3099     case ARM::VST1d8Twb_fixed:
3100     case ARM::VST1d16Twb_fixed:
3101     case ARM::VST1d32Twb_fixed:
3102     case ARM::VST1d64Twb_fixed:
3103     case ARM::VST1d8Qwb_fixed:
3104     case ARM::VST1d16Qwb_fixed:
3105     case ARM::VST1d32Qwb_fixed:
3106     case ARM::VST1d64Qwb_fixed:
3107     case ARM::VST2d8wb_fixed:
3108     case ARM::VST2d16wb_fixed:
3109     case ARM::VST2d32wb_fixed:
3110     case ARM::VST2q8wb_fixed:
3111     case ARM::VST2q16wb_fixed:
3112     case ARM::VST2q32wb_fixed:
3113     case ARM::VST2b8wb_fixed:
3114     case ARM::VST2b16wb_fixed:
3115     case ARM::VST2b32wb_fixed:
3116       break;
3117   }
3118 
3119   // First input register
3120   switch (Inst.getOpcode()) {
3121   case ARM::VST1q16:
3122   case ARM::VST1q32:
3123   case ARM::VST1q64:
3124   case ARM::VST1q8:
3125   case ARM::VST1q16wb_fixed:
3126   case ARM::VST1q16wb_register:
3127   case ARM::VST1q32wb_fixed:
3128   case ARM::VST1q32wb_register:
3129   case ARM::VST1q64wb_fixed:
3130   case ARM::VST1q64wb_register:
3131   case ARM::VST1q8wb_fixed:
3132   case ARM::VST1q8wb_register:
3133   case ARM::VST2d16:
3134   case ARM::VST2d32:
3135   case ARM::VST2d8:
3136   case ARM::VST2d16wb_fixed:
3137   case ARM::VST2d16wb_register:
3138   case ARM::VST2d32wb_fixed:
3139   case ARM::VST2d32wb_register:
3140   case ARM::VST2d8wb_fixed:
3141   case ARM::VST2d8wb_register:
3142     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3143       return MCDisassembler::Fail;
3144     break;
3145   case ARM::VST2b16:
3146   case ARM::VST2b32:
3147   case ARM::VST2b8:
3148   case ARM::VST2b16wb_fixed:
3149   case ARM::VST2b16wb_register:
3150   case ARM::VST2b32wb_fixed:
3151   case ARM::VST2b32wb_register:
3152   case ARM::VST2b8wb_fixed:
3153   case ARM::VST2b8wb_register:
3154     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
3155       return MCDisassembler::Fail;
3156     break;
3157   default:
3158     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3159       return MCDisassembler::Fail;
3160   }
3161 
3162   // Second input register
3163   switch (Inst.getOpcode()) {
3164     case ARM::VST3d8:
3165     case ARM::VST3d16:
3166     case ARM::VST3d32:
3167     case ARM::VST3d8_UPD:
3168     case ARM::VST3d16_UPD:
3169     case ARM::VST3d32_UPD:
3170     case ARM::VST4d8:
3171     case ARM::VST4d16:
3172     case ARM::VST4d32:
3173     case ARM::VST4d8_UPD:
3174     case ARM::VST4d16_UPD:
3175     case ARM::VST4d32_UPD:
3176       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
3177         return MCDisassembler::Fail;
3178       break;
3179     case ARM::VST3q8:
3180     case ARM::VST3q16:
3181     case ARM::VST3q32:
3182     case ARM::VST3q8_UPD:
3183     case ARM::VST3q16_UPD:
3184     case ARM::VST3q32_UPD:
3185     case ARM::VST4q8:
3186     case ARM::VST4q16:
3187     case ARM::VST4q32:
3188     case ARM::VST4q8_UPD:
3189     case ARM::VST4q16_UPD:
3190     case ARM::VST4q32_UPD:
3191       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
3192         return MCDisassembler::Fail;
3193       break;
3194     default:
3195       break;
3196   }
3197 
3198   // Third input register
3199   switch (Inst.getOpcode()) {
3200     case ARM::VST3d8:
3201     case ARM::VST3d16:
3202     case ARM::VST3d32:
3203     case ARM::VST3d8_UPD:
3204     case ARM::VST3d16_UPD:
3205     case ARM::VST3d32_UPD:
3206     case ARM::VST4d8:
3207     case ARM::VST4d16:
3208     case ARM::VST4d32:
3209     case ARM::VST4d8_UPD:
3210     case ARM::VST4d16_UPD:
3211     case ARM::VST4d32_UPD:
3212       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
3213         return MCDisassembler::Fail;
3214       break;
3215     case ARM::VST3q8:
3216     case ARM::VST3q16:
3217     case ARM::VST3q32:
3218     case ARM::VST3q8_UPD:
3219     case ARM::VST3q16_UPD:
3220     case ARM::VST3q32_UPD:
3221     case ARM::VST4q8:
3222     case ARM::VST4q16:
3223     case ARM::VST4q32:
3224     case ARM::VST4q8_UPD:
3225     case ARM::VST4q16_UPD:
3226     case ARM::VST4q32_UPD:
3227       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
3228         return MCDisassembler::Fail;
3229       break;
3230     default:
3231       break;
3232   }
3233 
3234   // Fourth input register
3235   switch (Inst.getOpcode()) {
3236     case ARM::VST4d8:
3237     case ARM::VST4d16:
3238     case ARM::VST4d32:
3239     case ARM::VST4d8_UPD:
3240     case ARM::VST4d16_UPD:
3241     case ARM::VST4d32_UPD:
3242       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
3243         return MCDisassembler::Fail;
3244       break;
3245     case ARM::VST4q8:
3246     case ARM::VST4q16:
3247     case ARM::VST4q32:
3248     case ARM::VST4q8_UPD:
3249     case ARM::VST4q16_UPD:
3250     case ARM::VST4q32_UPD:
3251       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
3252         return MCDisassembler::Fail;
3253       break;
3254     default:
3255       break;
3256   }
3257 
3258   return S;
3259 }
3260 
3261 static DecodeStatus DecodeVLD1DupInstruction(MCInst &Inst, unsigned Insn,
3262                                     uint64_t Address, const void *Decoder) {
3263   DecodeStatus S = MCDisassembler::Success;
3264 
3265   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3266   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3267   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3268   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3269   unsigned align = fieldFromInstruction(Insn, 4, 1);
3270   unsigned size = fieldFromInstruction(Insn, 6, 2);
3271 
3272   if (size == 0 && align == 1)
3273     return MCDisassembler::Fail;
3274   align *= (1 << size);
3275 
3276   switch (Inst.getOpcode()) {
3277   case ARM::VLD1DUPq16: case ARM::VLD1DUPq32: case ARM::VLD1DUPq8:
3278   case ARM::VLD1DUPq16wb_fixed: case ARM::VLD1DUPq16wb_register:
3279   case ARM::VLD1DUPq32wb_fixed: case ARM::VLD1DUPq32wb_register:
3280   case ARM::VLD1DUPq8wb_fixed: case ARM::VLD1DUPq8wb_register:
3281     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3282       return MCDisassembler::Fail;
3283     break;
3284   default:
3285     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3286       return MCDisassembler::Fail;
3287     break;
3288   }
3289   if (Rm != 0xF) {
3290     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3291       return MCDisassembler::Fail;
3292   }
3293 
3294   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3295     return MCDisassembler::Fail;
3296   Inst.addOperand(MCOperand::createImm(align));
3297 
3298   // The fixed offset post-increment encodes Rm == 0xd. The no-writeback
3299   // variant encodes Rm == 0xf. Anything else is a register offset post-
3300   // increment and we need to add the register operand to the instruction.
3301   if (Rm != 0xD && Rm != 0xF &&
3302       !Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3303     return MCDisassembler::Fail;
3304 
3305   return S;
3306 }
3307 
3308 static DecodeStatus DecodeVLD2DupInstruction(MCInst &Inst, unsigned Insn,
3309                                     uint64_t Address, const void *Decoder) {
3310   DecodeStatus S = MCDisassembler::Success;
3311 
3312   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3313   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3314   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3315   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3316   unsigned align = fieldFromInstruction(Insn, 4, 1);
3317   unsigned size = 1 << fieldFromInstruction(Insn, 6, 2);
3318   align *= 2*size;
3319 
3320   switch (Inst.getOpcode()) {
3321   case ARM::VLD2DUPd16: case ARM::VLD2DUPd32: case ARM::VLD2DUPd8:
3322   case ARM::VLD2DUPd16wb_fixed: case ARM::VLD2DUPd16wb_register:
3323   case ARM::VLD2DUPd32wb_fixed: case ARM::VLD2DUPd32wb_register:
3324   case ARM::VLD2DUPd8wb_fixed: case ARM::VLD2DUPd8wb_register:
3325     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3326       return MCDisassembler::Fail;
3327     break;
3328   case ARM::VLD2DUPd16x2: case ARM::VLD2DUPd32x2: case ARM::VLD2DUPd8x2:
3329   case ARM::VLD2DUPd16x2wb_fixed: case ARM::VLD2DUPd16x2wb_register:
3330   case ARM::VLD2DUPd32x2wb_fixed: case ARM::VLD2DUPd32x2wb_register:
3331   case ARM::VLD2DUPd8x2wb_fixed: case ARM::VLD2DUPd8x2wb_register:
3332     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
3333       return MCDisassembler::Fail;
3334     break;
3335   default:
3336     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3337       return MCDisassembler::Fail;
3338     break;
3339   }
3340 
3341   if (Rm != 0xF)
3342     Inst.addOperand(MCOperand::createImm(0));
3343 
3344   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3345     return MCDisassembler::Fail;
3346   Inst.addOperand(MCOperand::createImm(align));
3347 
3348   if (Rm != 0xD && Rm != 0xF) {
3349     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3350       return MCDisassembler::Fail;
3351   }
3352 
3353   return S;
3354 }
3355 
3356 static DecodeStatus DecodeVLD3DupInstruction(MCInst &Inst, unsigned Insn,
3357                                     uint64_t Address, const void *Decoder) {
3358   DecodeStatus S = MCDisassembler::Success;
3359 
3360   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3361   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3362   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3363   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3364   unsigned inc = fieldFromInstruction(Insn, 5, 1) + 1;
3365 
3366   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3367     return MCDisassembler::Fail;
3368   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
3369     return MCDisassembler::Fail;
3370   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
3371     return MCDisassembler::Fail;
3372   if (Rm != 0xF) {
3373     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3374       return MCDisassembler::Fail;
3375   }
3376 
3377   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3378     return MCDisassembler::Fail;
3379   Inst.addOperand(MCOperand::createImm(0));
3380 
3381   if (Rm == 0xD)
3382     Inst.addOperand(MCOperand::createReg(0));
3383   else if (Rm != 0xF) {
3384     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3385       return MCDisassembler::Fail;
3386   }
3387 
3388   return S;
3389 }
3390 
3391 static DecodeStatus DecodeVLD4DupInstruction(MCInst &Inst, unsigned Insn,
3392                                     uint64_t Address, const void *Decoder) {
3393   DecodeStatus S = MCDisassembler::Success;
3394 
3395   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3396   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3397   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3398   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3399   unsigned size = fieldFromInstruction(Insn, 6, 2);
3400   unsigned inc = fieldFromInstruction(Insn, 5, 1) + 1;
3401   unsigned align = fieldFromInstruction(Insn, 4, 1);
3402 
3403   if (size == 0x3) {
3404     if (align == 0)
3405       return MCDisassembler::Fail;
3406     align = 16;
3407   } else {
3408     if (size == 2) {
3409       align *= 8;
3410     } else {
3411       size = 1 << size;
3412       align *= 4*size;
3413     }
3414   }
3415 
3416   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3417     return MCDisassembler::Fail;
3418   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
3419     return MCDisassembler::Fail;
3420   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
3421     return MCDisassembler::Fail;
3422   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3*inc)%32, Address, Decoder)))
3423     return MCDisassembler::Fail;
3424   if (Rm != 0xF) {
3425     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3426       return MCDisassembler::Fail;
3427   }
3428 
3429   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3430     return MCDisassembler::Fail;
3431   Inst.addOperand(MCOperand::createImm(align));
3432 
3433   if (Rm == 0xD)
3434     Inst.addOperand(MCOperand::createReg(0));
3435   else if (Rm != 0xF) {
3436     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3437       return MCDisassembler::Fail;
3438   }
3439 
3440   return S;
3441 }
3442 
3443 static DecodeStatus
3444 DecodeVMOVModImmInstruction(MCInst &Inst, unsigned Insn,
3445                             uint64_t Address, const void *Decoder) {
3446   DecodeStatus S = MCDisassembler::Success;
3447 
3448   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3449   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3450   unsigned imm = fieldFromInstruction(Insn, 0, 4);
3451   imm |= fieldFromInstruction(Insn, 16, 3) << 4;
3452   imm |= fieldFromInstruction(Insn, 24, 1) << 7;
3453   imm |= fieldFromInstruction(Insn, 8, 4) << 8;
3454   imm |= fieldFromInstruction(Insn, 5, 1) << 12;
3455   unsigned Q = fieldFromInstruction(Insn, 6, 1);
3456 
3457   if (Q) {
3458     if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3459     return MCDisassembler::Fail;
3460   } else {
3461     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3462     return MCDisassembler::Fail;
3463   }
3464 
3465   Inst.addOperand(MCOperand::createImm(imm));
3466 
3467   switch (Inst.getOpcode()) {
3468     case ARM::VORRiv4i16:
3469     case ARM::VORRiv2i32:
3470     case ARM::VBICiv4i16:
3471     case ARM::VBICiv2i32:
3472       if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3473         return MCDisassembler::Fail;
3474       break;
3475     case ARM::VORRiv8i16:
3476     case ARM::VORRiv4i32:
3477     case ARM::VBICiv8i16:
3478     case ARM::VBICiv4i32:
3479       if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3480         return MCDisassembler::Fail;
3481       break;
3482     default:
3483       break;
3484   }
3485 
3486   return S;
3487 }
3488 
3489 static DecodeStatus
3490 DecodeMVEModImmInstruction(MCInst &Inst, unsigned Insn,
3491                            uint64_t Address, const void *Decoder) {
3492   DecodeStatus S = MCDisassembler::Success;
3493 
3494   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
3495                  fieldFromInstruction(Insn, 13, 3));
3496   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
3497   unsigned imm = fieldFromInstruction(Insn, 0, 4);
3498   imm |= fieldFromInstruction(Insn, 16, 3) << 4;
3499   imm |= fieldFromInstruction(Insn, 28, 1) << 7;
3500   imm |= cmode                             << 8;
3501   imm |= fieldFromInstruction(Insn, 5, 1)  << 12;
3502 
3503   if (cmode == 0xF && Inst.getOpcode() == ARM::MVE_VMVNimmi32)
3504     return MCDisassembler::Fail;
3505 
3506   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
3507     return MCDisassembler::Fail;
3508 
3509   Inst.addOperand(MCOperand::createImm(imm));
3510 
3511   Inst.addOperand(MCOperand::createImm(ARMVCC::None));
3512   Inst.addOperand(MCOperand::createReg(0));
3513   Inst.addOperand(MCOperand::createImm(0));
3514 
3515   return S;
3516 }
3517 
3518 static DecodeStatus DecodeMVEVADCInstruction(MCInst &Inst, unsigned Insn,
3519                                uint64_t Address, const void *Decoder) {
3520   DecodeStatus S = MCDisassembler::Success;
3521 
3522   unsigned Qd = fieldFromInstruction(Insn, 13, 3);
3523   Qd |= fieldFromInstruction(Insn, 22, 1) << 3;
3524   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
3525     return MCDisassembler::Fail;
3526   Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
3527 
3528   unsigned Qn = fieldFromInstruction(Insn, 17, 3);
3529   Qn |= fieldFromInstruction(Insn, 7, 1) << 3;
3530   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qn, Address, Decoder)))
3531     return MCDisassembler::Fail;
3532   unsigned Qm = fieldFromInstruction(Insn, 1, 3);
3533   Qm |= fieldFromInstruction(Insn, 5, 1) << 3;
3534   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
3535     return MCDisassembler::Fail;
3536   if (!fieldFromInstruction(Insn, 12, 1)) // I bit clear => need input FPSCR
3537     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
3538   Inst.addOperand(MCOperand::createImm(Qd));
3539 
3540   return S;
3541 }
3542 
3543 static DecodeStatus DecodeVSHLMaxInstruction(MCInst &Inst, unsigned Insn,
3544                                         uint64_t Address, const void *Decoder) {
3545   DecodeStatus S = MCDisassembler::Success;
3546 
3547   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3548   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3549   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3550   Rm |= fieldFromInstruction(Insn, 5, 1) << 4;
3551   unsigned size = fieldFromInstruction(Insn, 18, 2);
3552 
3553   if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3554     return MCDisassembler::Fail;
3555   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
3556     return MCDisassembler::Fail;
3557   Inst.addOperand(MCOperand::createImm(8 << size));
3558 
3559   return S;
3560 }
3561 
3562 static DecodeStatus DecodeShiftRight8Imm(MCInst &Inst, unsigned Val,
3563                                uint64_t Address, const void *Decoder) {
3564   Inst.addOperand(MCOperand::createImm(8 - Val));
3565   return MCDisassembler::Success;
3566 }
3567 
3568 static DecodeStatus DecodeShiftRight16Imm(MCInst &Inst, unsigned Val,
3569                                uint64_t Address, const void *Decoder) {
3570   Inst.addOperand(MCOperand::createImm(16 - Val));
3571   return MCDisassembler::Success;
3572 }
3573 
3574 static DecodeStatus DecodeShiftRight32Imm(MCInst &Inst, unsigned Val,
3575                                uint64_t Address, const void *Decoder) {
3576   Inst.addOperand(MCOperand::createImm(32 - Val));
3577   return MCDisassembler::Success;
3578 }
3579 
3580 static DecodeStatus DecodeShiftRight64Imm(MCInst &Inst, unsigned Val,
3581                                uint64_t Address, const void *Decoder) {
3582   Inst.addOperand(MCOperand::createImm(64 - Val));
3583   return MCDisassembler::Success;
3584 }
3585 
3586 static DecodeStatus DecodeTBLInstruction(MCInst &Inst, unsigned Insn,
3587                                uint64_t Address, const void *Decoder) {
3588   DecodeStatus S = MCDisassembler::Success;
3589 
3590   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3591   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3592   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3593   Rn |= fieldFromInstruction(Insn, 7, 1) << 4;
3594   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3595   Rm |= fieldFromInstruction(Insn, 5, 1) << 4;
3596   unsigned op = fieldFromInstruction(Insn, 6, 1);
3597 
3598   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3599     return MCDisassembler::Fail;
3600   if (op) {
3601     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3602     return MCDisassembler::Fail; // Writeback
3603   }
3604 
3605   switch (Inst.getOpcode()) {
3606   case ARM::VTBL2:
3607   case ARM::VTBX2:
3608     if (!Check(S, DecodeDPairRegisterClass(Inst, Rn, Address, Decoder)))
3609       return MCDisassembler::Fail;
3610     break;
3611   default:
3612     if (!Check(S, DecodeDPRRegisterClass(Inst, Rn, Address, Decoder)))
3613       return MCDisassembler::Fail;
3614   }
3615 
3616   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
3617     return MCDisassembler::Fail;
3618 
3619   return S;
3620 }
3621 
3622 static DecodeStatus DecodeThumbAddSpecialReg(MCInst &Inst, uint16_t Insn,
3623                                      uint64_t Address, const void *Decoder) {
3624   DecodeStatus S = MCDisassembler::Success;
3625 
3626   unsigned dst = fieldFromInstruction(Insn, 8, 3);
3627   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3628 
3629   if (!Check(S, DecodetGPRRegisterClass(Inst, dst, Address, Decoder)))
3630     return MCDisassembler::Fail;
3631 
3632   switch(Inst.getOpcode()) {
3633     default:
3634       return MCDisassembler::Fail;
3635     case ARM::tADR:
3636       break; // tADR does not explicitly represent the PC as an operand.
3637     case ARM::tADDrSPi:
3638       Inst.addOperand(MCOperand::createReg(ARM::SP));
3639       break;
3640   }
3641 
3642   Inst.addOperand(MCOperand::createImm(imm));
3643   return S;
3644 }
3645 
3646 static DecodeStatus DecodeThumbBROperand(MCInst &Inst, unsigned Val,
3647                                  uint64_t Address, const void *Decoder) {
3648   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<12>(Val<<1) + 4,
3649                                 true, 2, Inst, Decoder))
3650     Inst.addOperand(MCOperand::createImm(SignExtend32<12>(Val << 1)));
3651   return MCDisassembler::Success;
3652 }
3653 
3654 static DecodeStatus DecodeT2BROperand(MCInst &Inst, unsigned Val,
3655                                  uint64_t Address, const void *Decoder) {
3656   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<21>(Val) + 4,
3657                                 true, 4, Inst, Decoder))
3658     Inst.addOperand(MCOperand::createImm(SignExtend32<21>(Val)));
3659   return MCDisassembler::Success;
3660 }
3661 
3662 static DecodeStatus DecodeThumbCmpBROperand(MCInst &Inst, unsigned Val,
3663                                  uint64_t Address, const void *Decoder) {
3664   if (!tryAddingSymbolicOperand(Address, Address + (Val<<1) + 4,
3665                                 true, 2, Inst, Decoder))
3666     Inst.addOperand(MCOperand::createImm(Val << 1));
3667   return MCDisassembler::Success;
3668 }
3669 
3670 static DecodeStatus DecodeThumbAddrModeRR(MCInst &Inst, unsigned Val,
3671                                  uint64_t Address, const void *Decoder) {
3672   DecodeStatus S = MCDisassembler::Success;
3673 
3674   unsigned Rn = fieldFromInstruction(Val, 0, 3);
3675   unsigned Rm = fieldFromInstruction(Val, 3, 3);
3676 
3677   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
3678     return MCDisassembler::Fail;
3679   if (!Check(S, DecodetGPRRegisterClass(Inst, Rm, Address, Decoder)))
3680     return MCDisassembler::Fail;
3681 
3682   return S;
3683 }
3684 
3685 static DecodeStatus DecodeThumbAddrModeIS(MCInst &Inst, unsigned Val,
3686                                   uint64_t Address, const void *Decoder) {
3687   DecodeStatus S = MCDisassembler::Success;
3688 
3689   unsigned Rn = fieldFromInstruction(Val, 0, 3);
3690   unsigned imm = fieldFromInstruction(Val, 3, 5);
3691 
3692   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
3693     return MCDisassembler::Fail;
3694   Inst.addOperand(MCOperand::createImm(imm));
3695 
3696   return S;
3697 }
3698 
3699 static DecodeStatus DecodeThumbAddrModePC(MCInst &Inst, unsigned Val,
3700                                   uint64_t Address, const void *Decoder) {
3701   unsigned imm = Val << 2;
3702 
3703   Inst.addOperand(MCOperand::createImm(imm));
3704   tryAddingPcLoadReferenceComment(Address, (Address & ~2u) + imm + 4, Decoder);
3705 
3706   return MCDisassembler::Success;
3707 }
3708 
3709 static DecodeStatus DecodeThumbAddrModeSP(MCInst &Inst, unsigned Val,
3710                                   uint64_t Address, const void *Decoder) {
3711   Inst.addOperand(MCOperand::createReg(ARM::SP));
3712   Inst.addOperand(MCOperand::createImm(Val));
3713 
3714   return MCDisassembler::Success;
3715 }
3716 
3717 static DecodeStatus DecodeT2AddrModeSOReg(MCInst &Inst, unsigned Val,
3718                                   uint64_t Address, const void *Decoder) {
3719   DecodeStatus S = MCDisassembler::Success;
3720 
3721   unsigned Rn = fieldFromInstruction(Val, 6, 4);
3722   unsigned Rm = fieldFromInstruction(Val, 2, 4);
3723   unsigned imm = fieldFromInstruction(Val, 0, 2);
3724 
3725   // Thumb stores cannot use PC as dest register.
3726   switch (Inst.getOpcode()) {
3727   case ARM::t2STRHs:
3728   case ARM::t2STRBs:
3729   case ARM::t2STRs:
3730     if (Rn == 15)
3731       return MCDisassembler::Fail;
3732     break;
3733   default:
3734     break;
3735   }
3736 
3737   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3738     return MCDisassembler::Fail;
3739   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
3740     return MCDisassembler::Fail;
3741   Inst.addOperand(MCOperand::createImm(imm));
3742 
3743   return S;
3744 }
3745 
3746 static DecodeStatus DecodeT2LoadShift(MCInst &Inst, unsigned Insn,
3747                               uint64_t Address, const void *Decoder) {
3748   DecodeStatus S = MCDisassembler::Success;
3749 
3750   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3751   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3752 
3753   const FeatureBitset &featureBits =
3754     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3755 
3756   bool hasMP = featureBits[ARM::FeatureMP];
3757   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3758 
3759   if (Rn == 15) {
3760     switch (Inst.getOpcode()) {
3761     case ARM::t2LDRBs:
3762       Inst.setOpcode(ARM::t2LDRBpci);
3763       break;
3764     case ARM::t2LDRHs:
3765       Inst.setOpcode(ARM::t2LDRHpci);
3766       break;
3767     case ARM::t2LDRSHs:
3768       Inst.setOpcode(ARM::t2LDRSHpci);
3769       break;
3770     case ARM::t2LDRSBs:
3771       Inst.setOpcode(ARM::t2LDRSBpci);
3772       break;
3773     case ARM::t2LDRs:
3774       Inst.setOpcode(ARM::t2LDRpci);
3775       break;
3776     case ARM::t2PLDs:
3777       Inst.setOpcode(ARM::t2PLDpci);
3778       break;
3779     case ARM::t2PLIs:
3780       Inst.setOpcode(ARM::t2PLIpci);
3781       break;
3782     default:
3783       return MCDisassembler::Fail;
3784     }
3785 
3786     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3787   }
3788 
3789   if (Rt == 15) {
3790     switch (Inst.getOpcode()) {
3791     case ARM::t2LDRSHs:
3792       return MCDisassembler::Fail;
3793     case ARM::t2LDRHs:
3794       Inst.setOpcode(ARM::t2PLDWs);
3795       break;
3796     case ARM::t2LDRSBs:
3797       Inst.setOpcode(ARM::t2PLIs);
3798       break;
3799     default:
3800       break;
3801     }
3802   }
3803 
3804   switch (Inst.getOpcode()) {
3805     case ARM::t2PLDs:
3806       break;
3807     case ARM::t2PLIs:
3808       if (!hasV7Ops)
3809         return MCDisassembler::Fail;
3810       break;
3811     case ARM::t2PLDWs:
3812       if (!hasV7Ops || !hasMP)
3813         return MCDisassembler::Fail;
3814       break;
3815     default:
3816       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3817         return MCDisassembler::Fail;
3818   }
3819 
3820   unsigned addrmode = fieldFromInstruction(Insn, 4, 2);
3821   addrmode |= fieldFromInstruction(Insn, 0, 4) << 2;
3822   addrmode |= fieldFromInstruction(Insn, 16, 4) << 6;
3823   if (!Check(S, DecodeT2AddrModeSOReg(Inst, addrmode, Address, Decoder)))
3824     return MCDisassembler::Fail;
3825 
3826   return S;
3827 }
3828 
3829 static DecodeStatus DecodeT2LoadImm8(MCInst &Inst, unsigned Insn,
3830                                 uint64_t Address, const void* Decoder) {
3831   DecodeStatus S = MCDisassembler::Success;
3832 
3833   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3834   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3835   unsigned U = fieldFromInstruction(Insn, 9, 1);
3836   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3837   imm |= (U << 8);
3838   imm |= (Rn << 9);
3839   unsigned add = fieldFromInstruction(Insn, 9, 1);
3840 
3841   const FeatureBitset &featureBits =
3842     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3843 
3844   bool hasMP = featureBits[ARM::FeatureMP];
3845   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3846 
3847   if (Rn == 15) {
3848     switch (Inst.getOpcode()) {
3849     case ARM::t2LDRi8:
3850       Inst.setOpcode(ARM::t2LDRpci);
3851       break;
3852     case ARM::t2LDRBi8:
3853       Inst.setOpcode(ARM::t2LDRBpci);
3854       break;
3855     case ARM::t2LDRSBi8:
3856       Inst.setOpcode(ARM::t2LDRSBpci);
3857       break;
3858     case ARM::t2LDRHi8:
3859       Inst.setOpcode(ARM::t2LDRHpci);
3860       break;
3861     case ARM::t2LDRSHi8:
3862       Inst.setOpcode(ARM::t2LDRSHpci);
3863       break;
3864     case ARM::t2PLDi8:
3865       Inst.setOpcode(ARM::t2PLDpci);
3866       break;
3867     case ARM::t2PLIi8:
3868       Inst.setOpcode(ARM::t2PLIpci);
3869       break;
3870     default:
3871       return MCDisassembler::Fail;
3872     }
3873     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3874   }
3875 
3876   if (Rt == 15) {
3877     switch (Inst.getOpcode()) {
3878     case ARM::t2LDRSHi8:
3879       return MCDisassembler::Fail;
3880     case ARM::t2LDRHi8:
3881       if (!add)
3882         Inst.setOpcode(ARM::t2PLDWi8);
3883       break;
3884     case ARM::t2LDRSBi8:
3885       Inst.setOpcode(ARM::t2PLIi8);
3886       break;
3887     default:
3888       break;
3889     }
3890   }
3891 
3892   switch (Inst.getOpcode()) {
3893   case ARM::t2PLDi8:
3894     break;
3895   case ARM::t2PLIi8:
3896     if (!hasV7Ops)
3897       return MCDisassembler::Fail;
3898     break;
3899   case ARM::t2PLDWi8:
3900       if (!hasV7Ops || !hasMP)
3901         return MCDisassembler::Fail;
3902       break;
3903   default:
3904     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3905       return MCDisassembler::Fail;
3906   }
3907 
3908   if (!Check(S, DecodeT2AddrModeImm8(Inst, imm, Address, Decoder)))
3909     return MCDisassembler::Fail;
3910   return S;
3911 }
3912 
3913 static DecodeStatus DecodeT2LoadImm12(MCInst &Inst, unsigned Insn,
3914                                 uint64_t Address, const void* Decoder) {
3915   DecodeStatus S = MCDisassembler::Success;
3916 
3917   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3918   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3919   unsigned imm = fieldFromInstruction(Insn, 0, 12);
3920   imm |= (Rn << 13);
3921 
3922   const FeatureBitset &featureBits =
3923     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3924 
3925   bool hasMP = featureBits[ARM::FeatureMP];
3926   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3927 
3928   if (Rn == 15) {
3929     switch (Inst.getOpcode()) {
3930     case ARM::t2LDRi12:
3931       Inst.setOpcode(ARM::t2LDRpci);
3932       break;
3933     case ARM::t2LDRHi12:
3934       Inst.setOpcode(ARM::t2LDRHpci);
3935       break;
3936     case ARM::t2LDRSHi12:
3937       Inst.setOpcode(ARM::t2LDRSHpci);
3938       break;
3939     case ARM::t2LDRBi12:
3940       Inst.setOpcode(ARM::t2LDRBpci);
3941       break;
3942     case ARM::t2LDRSBi12:
3943       Inst.setOpcode(ARM::t2LDRSBpci);
3944       break;
3945     case ARM::t2PLDi12:
3946       Inst.setOpcode(ARM::t2PLDpci);
3947       break;
3948     case ARM::t2PLIi12:
3949       Inst.setOpcode(ARM::t2PLIpci);
3950       break;
3951     default:
3952       return MCDisassembler::Fail;
3953     }
3954     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3955   }
3956 
3957   if (Rt == 15) {
3958     switch (Inst.getOpcode()) {
3959     case ARM::t2LDRSHi12:
3960       return MCDisassembler::Fail;
3961     case ARM::t2LDRHi12:
3962       Inst.setOpcode(ARM::t2PLDWi12);
3963       break;
3964     case ARM::t2LDRSBi12:
3965       Inst.setOpcode(ARM::t2PLIi12);
3966       break;
3967     default:
3968       break;
3969     }
3970   }
3971 
3972   switch (Inst.getOpcode()) {
3973   case ARM::t2PLDi12:
3974     break;
3975   case ARM::t2PLIi12:
3976     if (!hasV7Ops)
3977       return MCDisassembler::Fail;
3978     break;
3979   case ARM::t2PLDWi12:
3980       if (!hasV7Ops || !hasMP)
3981         return MCDisassembler::Fail;
3982       break;
3983   default:
3984     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3985       return MCDisassembler::Fail;
3986   }
3987 
3988   if (!Check(S, DecodeT2AddrModeImm12(Inst, imm, Address, Decoder)))
3989     return MCDisassembler::Fail;
3990   return S;
3991 }
3992 
3993 static DecodeStatus DecodeT2LoadT(MCInst &Inst, unsigned Insn,
3994                                 uint64_t Address, const void* Decoder) {
3995   DecodeStatus S = MCDisassembler::Success;
3996 
3997   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3998   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3999   unsigned imm = fieldFromInstruction(Insn, 0, 8);
4000   imm |= (Rn << 9);
4001 
4002   if (Rn == 15) {
4003     switch (Inst.getOpcode()) {
4004     case ARM::t2LDRT:
4005       Inst.setOpcode(ARM::t2LDRpci);
4006       break;
4007     case ARM::t2LDRBT:
4008       Inst.setOpcode(ARM::t2LDRBpci);
4009       break;
4010     case ARM::t2LDRHT:
4011       Inst.setOpcode(ARM::t2LDRHpci);
4012       break;
4013     case ARM::t2LDRSBT:
4014       Inst.setOpcode(ARM::t2LDRSBpci);
4015       break;
4016     case ARM::t2LDRSHT:
4017       Inst.setOpcode(ARM::t2LDRSHpci);
4018       break;
4019     default:
4020       return MCDisassembler::Fail;
4021     }
4022     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
4023   }
4024 
4025   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
4026     return MCDisassembler::Fail;
4027   if (!Check(S, DecodeT2AddrModeImm8(Inst, imm, Address, Decoder)))
4028     return MCDisassembler::Fail;
4029   return S;
4030 }
4031 
4032 static DecodeStatus DecodeT2LoadLabel(MCInst &Inst, unsigned Insn,
4033                                 uint64_t Address, const void* Decoder) {
4034   DecodeStatus S = MCDisassembler::Success;
4035 
4036   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4037   unsigned U = fieldFromInstruction(Insn, 23, 1);
4038   int imm = fieldFromInstruction(Insn, 0, 12);
4039 
4040   const FeatureBitset &featureBits =
4041     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4042 
4043   bool hasV7Ops = featureBits[ARM::HasV7Ops];
4044 
4045   if (Rt == 15) {
4046     switch (Inst.getOpcode()) {
4047       case ARM::t2LDRBpci:
4048       case ARM::t2LDRHpci:
4049         Inst.setOpcode(ARM::t2PLDpci);
4050         break;
4051       case ARM::t2LDRSBpci:
4052         Inst.setOpcode(ARM::t2PLIpci);
4053         break;
4054       case ARM::t2LDRSHpci:
4055         return MCDisassembler::Fail;
4056       default:
4057         break;
4058     }
4059   }
4060 
4061   switch(Inst.getOpcode()) {
4062   case ARM::t2PLDpci:
4063     break;
4064   case ARM::t2PLIpci:
4065     if (!hasV7Ops)
4066       return MCDisassembler::Fail;
4067     break;
4068   default:
4069     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4070       return MCDisassembler::Fail;
4071   }
4072 
4073   if (!U) {
4074     // Special case for #-0.
4075     if (imm == 0)
4076       imm = INT32_MIN;
4077     else
4078       imm = -imm;
4079   }
4080   Inst.addOperand(MCOperand::createImm(imm));
4081 
4082   return S;
4083 }
4084 
4085 static DecodeStatus DecodeT2Imm8S4(MCInst &Inst, unsigned Val,
4086                            uint64_t Address, const void *Decoder) {
4087   if (Val == 0)
4088     Inst.addOperand(MCOperand::createImm(INT32_MIN));
4089   else {
4090     int imm = Val & 0xFF;
4091 
4092     if (!(Val & 0x100)) imm *= -1;
4093     Inst.addOperand(MCOperand::createImm(imm * 4));
4094   }
4095 
4096   return MCDisassembler::Success;
4097 }
4098 
4099 static DecodeStatus DecodeT2Imm7S4(MCInst &Inst, unsigned Val, uint64_t Address,
4100                                    const void *Decoder) {
4101   if (Val == 0)
4102     Inst.addOperand(MCOperand::createImm(INT32_MIN));
4103   else {
4104     int imm = Val & 0x7F;
4105 
4106     if (!(Val & 0x80))
4107       imm *= -1;
4108     Inst.addOperand(MCOperand::createImm(imm * 4));
4109   }
4110 
4111   return MCDisassembler::Success;
4112 }
4113 
4114 static DecodeStatus DecodeT2AddrModeImm8s4(MCInst &Inst, unsigned Val,
4115                                    uint64_t Address, const void *Decoder) {
4116   DecodeStatus S = MCDisassembler::Success;
4117 
4118   unsigned Rn = fieldFromInstruction(Val, 9, 4);
4119   unsigned imm = fieldFromInstruction(Val, 0, 9);
4120 
4121   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4122     return MCDisassembler::Fail;
4123   if (!Check(S, DecodeT2Imm8S4(Inst, imm, Address, Decoder)))
4124     return MCDisassembler::Fail;
4125 
4126   return S;
4127 }
4128 
4129 static DecodeStatus DecodeT2AddrModeImm7s4(MCInst &Inst, unsigned Val,
4130                                            uint64_t Address,
4131                                            const void *Decoder) {
4132   DecodeStatus S = MCDisassembler::Success;
4133 
4134   unsigned Rn = fieldFromInstruction(Val, 8, 4);
4135   unsigned imm = fieldFromInstruction(Val, 0, 8);
4136 
4137   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4138     return MCDisassembler::Fail;
4139   if (!Check(S, DecodeT2Imm7S4(Inst, imm, Address, Decoder)))
4140     return MCDisassembler::Fail;
4141 
4142   return S;
4143 }
4144 
4145 static DecodeStatus DecodeT2AddrModeImm0_1020s4(MCInst &Inst,unsigned Val,
4146                                    uint64_t Address, const void *Decoder) {
4147   DecodeStatus S = MCDisassembler::Success;
4148 
4149   unsigned Rn = fieldFromInstruction(Val, 8, 4);
4150   unsigned imm = fieldFromInstruction(Val, 0, 8);
4151 
4152   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4153     return MCDisassembler::Fail;
4154 
4155   Inst.addOperand(MCOperand::createImm(imm));
4156 
4157   return S;
4158 }
4159 
4160 static DecodeStatus DecodeT2Imm8(MCInst &Inst, unsigned Val,
4161                          uint64_t Address, const void *Decoder) {
4162   int imm = Val & 0xFF;
4163   if (Val == 0)
4164     imm = INT32_MIN;
4165   else if (!(Val & 0x100))
4166     imm *= -1;
4167   Inst.addOperand(MCOperand::createImm(imm));
4168 
4169   return MCDisassembler::Success;
4170 }
4171 
4172 template<int shift>
4173 static DecodeStatus DecodeT2Imm7(MCInst &Inst, unsigned Val,
4174                          uint64_t Address, const void *Decoder) {
4175   int imm = Val & 0x7F;
4176   if (Val == 0)
4177     imm = INT32_MIN;
4178   else if (!(Val & 0x80))
4179     imm *= -1;
4180   if (imm != INT32_MIN)
4181     imm *= (1U << shift);
4182   Inst.addOperand(MCOperand::createImm(imm));
4183 
4184   return MCDisassembler::Success;
4185 }
4186 
4187 static DecodeStatus DecodeT2AddrModeImm8(MCInst &Inst, unsigned Val,
4188                                  uint64_t Address, const void *Decoder) {
4189   DecodeStatus S = MCDisassembler::Success;
4190 
4191   unsigned Rn = fieldFromInstruction(Val, 9, 4);
4192   unsigned imm = fieldFromInstruction(Val, 0, 9);
4193 
4194   // Thumb stores cannot use PC as dest register.
4195   switch (Inst.getOpcode()) {
4196   case ARM::t2STRT:
4197   case ARM::t2STRBT:
4198   case ARM::t2STRHT:
4199   case ARM::t2STRi8:
4200   case ARM::t2STRHi8:
4201   case ARM::t2STRBi8:
4202     if (Rn == 15)
4203       return MCDisassembler::Fail;
4204     break;
4205   default:
4206     break;
4207   }
4208 
4209   // Some instructions always use an additive offset.
4210   switch (Inst.getOpcode()) {
4211     case ARM::t2LDRT:
4212     case ARM::t2LDRBT:
4213     case ARM::t2LDRHT:
4214     case ARM::t2LDRSBT:
4215     case ARM::t2LDRSHT:
4216     case ARM::t2STRT:
4217     case ARM::t2STRBT:
4218     case ARM::t2STRHT:
4219       imm |= 0x100;
4220       break;
4221     default:
4222       break;
4223   }
4224 
4225   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4226     return MCDisassembler::Fail;
4227   if (!Check(S, DecodeT2Imm8(Inst, imm, Address, Decoder)))
4228     return MCDisassembler::Fail;
4229 
4230   return S;
4231 }
4232 
4233 template<int shift>
4234 static DecodeStatus DecodeTAddrModeImm7(MCInst &Inst, unsigned Val,
4235                                          uint64_t Address,
4236                                          const void *Decoder) {
4237   DecodeStatus S = MCDisassembler::Success;
4238 
4239   unsigned Rn = fieldFromInstruction(Val, 8, 3);
4240   unsigned imm = fieldFromInstruction(Val, 0, 8);
4241 
4242   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
4243     return MCDisassembler::Fail;
4244   if (!Check(S, DecodeT2Imm7<shift>(Inst, imm, Address, Decoder)))
4245     return MCDisassembler::Fail;
4246 
4247   return S;
4248 }
4249 
4250 template<int shift, int WriteBack>
4251 static DecodeStatus DecodeT2AddrModeImm7(MCInst &Inst, unsigned Val,
4252                                          uint64_t Address,
4253                                          const void *Decoder) {
4254   DecodeStatus S = MCDisassembler::Success;
4255 
4256   unsigned Rn = fieldFromInstruction(Val, 8, 4);
4257   unsigned imm = fieldFromInstruction(Val, 0, 8);
4258   if (WriteBack) {
4259     if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
4260       return MCDisassembler::Fail;
4261   } else if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4262     return MCDisassembler::Fail;
4263   if (!Check(S, DecodeT2Imm7<shift>(Inst, imm, Address, Decoder)))
4264     return MCDisassembler::Fail;
4265 
4266   return S;
4267 }
4268 
4269 static DecodeStatus DecodeT2LdStPre(MCInst &Inst, unsigned Insn,
4270                                     uint64_t Address, const void *Decoder) {
4271   DecodeStatus S = MCDisassembler::Success;
4272 
4273   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4274   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4275   unsigned addr = fieldFromInstruction(Insn, 0, 8);
4276   addr |= fieldFromInstruction(Insn, 9, 1) << 8;
4277   addr |= Rn << 9;
4278   unsigned load = fieldFromInstruction(Insn, 20, 1);
4279 
4280   if (Rn == 15) {
4281     switch (Inst.getOpcode()) {
4282     case ARM::t2LDR_PRE:
4283     case ARM::t2LDR_POST:
4284       Inst.setOpcode(ARM::t2LDRpci);
4285       break;
4286     case ARM::t2LDRB_PRE:
4287     case ARM::t2LDRB_POST:
4288       Inst.setOpcode(ARM::t2LDRBpci);
4289       break;
4290     case ARM::t2LDRH_PRE:
4291     case ARM::t2LDRH_POST:
4292       Inst.setOpcode(ARM::t2LDRHpci);
4293       break;
4294     case ARM::t2LDRSB_PRE:
4295     case ARM::t2LDRSB_POST:
4296       if (Rt == 15)
4297         Inst.setOpcode(ARM::t2PLIpci);
4298       else
4299         Inst.setOpcode(ARM::t2LDRSBpci);
4300       break;
4301     case ARM::t2LDRSH_PRE:
4302     case ARM::t2LDRSH_POST:
4303       Inst.setOpcode(ARM::t2LDRSHpci);
4304       break;
4305     default:
4306       return MCDisassembler::Fail;
4307     }
4308     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
4309   }
4310 
4311   if (!load) {
4312     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4313       return MCDisassembler::Fail;
4314   }
4315 
4316   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4317     return MCDisassembler::Fail;
4318 
4319   if (load) {
4320     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4321       return MCDisassembler::Fail;
4322   }
4323 
4324   if (!Check(S, DecodeT2AddrModeImm8(Inst, addr, Address, Decoder)))
4325     return MCDisassembler::Fail;
4326 
4327   return S;
4328 }
4329 
4330 static DecodeStatus DecodeT2AddrModeImm12(MCInst &Inst, unsigned Val,
4331                                   uint64_t Address, const void *Decoder) {
4332   DecodeStatus S = MCDisassembler::Success;
4333 
4334   unsigned Rn = fieldFromInstruction(Val, 13, 4);
4335   unsigned imm = fieldFromInstruction(Val, 0, 12);
4336 
4337   // Thumb stores cannot use PC as dest register.
4338   switch (Inst.getOpcode()) {
4339   case ARM::t2STRi12:
4340   case ARM::t2STRBi12:
4341   case ARM::t2STRHi12:
4342     if (Rn == 15)
4343       return MCDisassembler::Fail;
4344     break;
4345   default:
4346     break;
4347   }
4348 
4349   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4350     return MCDisassembler::Fail;
4351   Inst.addOperand(MCOperand::createImm(imm));
4352 
4353   return S;
4354 }
4355 
4356 static DecodeStatus DecodeThumbAddSPImm(MCInst &Inst, uint16_t Insn,
4357                                 uint64_t Address, const void *Decoder) {
4358   unsigned imm = fieldFromInstruction(Insn, 0, 7);
4359 
4360   Inst.addOperand(MCOperand::createReg(ARM::SP));
4361   Inst.addOperand(MCOperand::createReg(ARM::SP));
4362   Inst.addOperand(MCOperand::createImm(imm));
4363 
4364   return MCDisassembler::Success;
4365 }
4366 
4367 static DecodeStatus DecodeThumbAddSPReg(MCInst &Inst, uint16_t Insn,
4368                                 uint64_t Address, const void *Decoder) {
4369   DecodeStatus S = MCDisassembler::Success;
4370 
4371   if (Inst.getOpcode() == ARM::tADDrSP) {
4372     unsigned Rdm = fieldFromInstruction(Insn, 0, 3);
4373     Rdm |= fieldFromInstruction(Insn, 7, 1) << 3;
4374 
4375     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
4376     return MCDisassembler::Fail;
4377     Inst.addOperand(MCOperand::createReg(ARM::SP));
4378     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
4379     return MCDisassembler::Fail;
4380   } else if (Inst.getOpcode() == ARM::tADDspr) {
4381     unsigned Rm = fieldFromInstruction(Insn, 3, 4);
4382 
4383     Inst.addOperand(MCOperand::createReg(ARM::SP));
4384     Inst.addOperand(MCOperand::createReg(ARM::SP));
4385     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4386     return MCDisassembler::Fail;
4387   }
4388 
4389   return S;
4390 }
4391 
4392 static DecodeStatus DecodeThumbCPS(MCInst &Inst, uint16_t Insn,
4393                            uint64_t Address, const void *Decoder) {
4394   unsigned imod = fieldFromInstruction(Insn, 4, 1) | 0x2;
4395   unsigned flags = fieldFromInstruction(Insn, 0, 3);
4396 
4397   Inst.addOperand(MCOperand::createImm(imod));
4398   Inst.addOperand(MCOperand::createImm(flags));
4399 
4400   return MCDisassembler::Success;
4401 }
4402 
4403 static DecodeStatus DecodePostIdxReg(MCInst &Inst, unsigned Insn,
4404                              uint64_t Address, const void *Decoder) {
4405   DecodeStatus S = MCDisassembler::Success;
4406   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4407   unsigned add = fieldFromInstruction(Insn, 4, 1);
4408 
4409   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
4410     return MCDisassembler::Fail;
4411   Inst.addOperand(MCOperand::createImm(add));
4412 
4413   return S;
4414 }
4415 
4416 static DecodeStatus DecodeMveAddrModeRQ(MCInst &Inst, unsigned Insn,
4417                              uint64_t Address, const void *Decoder) {
4418   DecodeStatus S = MCDisassembler::Success;
4419   unsigned Rn = fieldFromInstruction(Insn, 3, 4);
4420   unsigned Qm = fieldFromInstruction(Insn, 0, 3);
4421 
4422   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4423     return MCDisassembler::Fail;
4424   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
4425     return MCDisassembler::Fail;
4426 
4427   return S;
4428 }
4429 
4430 template<int shift>
4431 static DecodeStatus DecodeMveAddrModeQ(MCInst &Inst, unsigned Insn,
4432                              uint64_t Address, const void *Decoder) {
4433   DecodeStatus S = MCDisassembler::Success;
4434   unsigned Qm = fieldFromInstruction(Insn, 8, 3);
4435   int imm = fieldFromInstruction(Insn, 0, 7);
4436 
4437   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
4438     return MCDisassembler::Fail;
4439 
4440   if(!fieldFromInstruction(Insn, 7, 1)) {
4441     if (imm == 0)
4442       imm = INT32_MIN;                 // indicate -0
4443     else
4444       imm *= -1;
4445   }
4446   if (imm != INT32_MIN)
4447     imm *= (1U << shift);
4448   Inst.addOperand(MCOperand::createImm(imm));
4449 
4450   return S;
4451 }
4452 
4453 static DecodeStatus DecodeThumbBLXOffset(MCInst &Inst, unsigned Val,
4454                                  uint64_t Address, const void *Decoder) {
4455   // Val is passed in as S:J1:J2:imm10H:imm10L:'0'
4456   // Note only one trailing zero not two.  Also the J1 and J2 values are from
4457   // the encoded instruction.  So here change to I1 and I2 values via:
4458   // I1 = NOT(J1 EOR S);
4459   // I2 = NOT(J2 EOR S);
4460   // and build the imm32 with two trailing zeros as documented:
4461   // imm32 = SignExtend(S:I1:I2:imm10H:imm10L:'00', 32);
4462   unsigned S = (Val >> 23) & 1;
4463   unsigned J1 = (Val >> 22) & 1;
4464   unsigned J2 = (Val >> 21) & 1;
4465   unsigned I1 = !(J1 ^ S);
4466   unsigned I2 = !(J2 ^ S);
4467   unsigned tmp = (Val & ~0x600000) | (I1 << 22) | (I2 << 21);
4468   int imm32 = SignExtend32<25>(tmp << 1);
4469 
4470   if (!tryAddingSymbolicOperand(Address,
4471                                 (Address & ~2u) + imm32 + 4,
4472                                 true, 4, Inst, Decoder))
4473     Inst.addOperand(MCOperand::createImm(imm32));
4474   return MCDisassembler::Success;
4475 }
4476 
4477 static DecodeStatus DecodeCoprocessor(MCInst &Inst, unsigned Val,
4478                               uint64_t Address, const void *Decoder) {
4479   if (Val == 0xA || Val == 0xB)
4480     return MCDisassembler::Fail;
4481 
4482   const FeatureBitset &featureBits =
4483     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4484 
4485   if (!isValidCoprocessorNumber(Val, featureBits))
4486     return MCDisassembler::Fail;
4487 
4488   Inst.addOperand(MCOperand::createImm(Val));
4489   return MCDisassembler::Success;
4490 }
4491 
4492 static DecodeStatus
4493 DecodeThumbTableBranch(MCInst &Inst, unsigned Insn,
4494                        uint64_t Address, const void *Decoder) {
4495   DecodeStatus S = MCDisassembler::Success;
4496 
4497   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4498   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4499 
4500   if (Rn == ARM::SP) S = MCDisassembler::SoftFail;
4501   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4502     return MCDisassembler::Fail;
4503   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
4504     return MCDisassembler::Fail;
4505   return S;
4506 }
4507 
4508 static DecodeStatus
4509 DecodeThumb2BCCInstruction(MCInst &Inst, unsigned Insn,
4510                            uint64_t Address, const void *Decoder) {
4511   DecodeStatus S = MCDisassembler::Success;
4512 
4513   unsigned pred = fieldFromInstruction(Insn, 22, 4);
4514   if (pred == 0xE || pred == 0xF) {
4515     unsigned opc = fieldFromInstruction(Insn, 4, 28);
4516     switch (opc) {
4517       default:
4518         return MCDisassembler::Fail;
4519       case 0xf3bf8f4:
4520         Inst.setOpcode(ARM::t2DSB);
4521         break;
4522       case 0xf3bf8f5:
4523         Inst.setOpcode(ARM::t2DMB);
4524         break;
4525       case 0xf3bf8f6:
4526         Inst.setOpcode(ARM::t2ISB);
4527         break;
4528     }
4529 
4530     unsigned imm = fieldFromInstruction(Insn, 0, 4);
4531     return DecodeMemBarrierOption(Inst, imm, Address, Decoder);
4532   }
4533 
4534   unsigned brtarget = fieldFromInstruction(Insn, 0, 11) << 1;
4535   brtarget |= fieldFromInstruction(Insn, 11, 1) << 19;
4536   brtarget |= fieldFromInstruction(Insn, 13, 1) << 18;
4537   brtarget |= fieldFromInstruction(Insn, 16, 6) << 12;
4538   brtarget |= fieldFromInstruction(Insn, 26, 1) << 20;
4539 
4540   if (!Check(S, DecodeT2BROperand(Inst, brtarget, Address, Decoder)))
4541     return MCDisassembler::Fail;
4542   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4543     return MCDisassembler::Fail;
4544 
4545   return S;
4546 }
4547 
4548 // Decode a shifted immediate operand.  These basically consist
4549 // of an 8-bit value, and a 4-bit directive that specifies either
4550 // a splat operation or a rotation.
4551 static DecodeStatus DecodeT2SOImm(MCInst &Inst, unsigned Val,
4552                           uint64_t Address, const void *Decoder) {
4553   unsigned ctrl = fieldFromInstruction(Val, 10, 2);
4554   if (ctrl == 0) {
4555     unsigned byte = fieldFromInstruction(Val, 8, 2);
4556     unsigned imm = fieldFromInstruction(Val, 0, 8);
4557     switch (byte) {
4558       case 0:
4559         Inst.addOperand(MCOperand::createImm(imm));
4560         break;
4561       case 1:
4562         Inst.addOperand(MCOperand::createImm((imm << 16) | imm));
4563         break;
4564       case 2:
4565         Inst.addOperand(MCOperand::createImm((imm << 24) | (imm << 8)));
4566         break;
4567       case 3:
4568         Inst.addOperand(MCOperand::createImm((imm << 24) | (imm << 16) |
4569                                              (imm << 8)  |  imm));
4570         break;
4571     }
4572   } else {
4573     unsigned unrot = fieldFromInstruction(Val, 0, 7) | 0x80;
4574     unsigned rot = fieldFromInstruction(Val, 7, 5);
4575     unsigned imm = (unrot >> rot) | (unrot << ((32-rot)&31));
4576     Inst.addOperand(MCOperand::createImm(imm));
4577   }
4578 
4579   return MCDisassembler::Success;
4580 }
4581 
4582 static DecodeStatus
4583 DecodeThumbBCCTargetOperand(MCInst &Inst, unsigned Val,
4584                             uint64_t Address, const void *Decoder) {
4585   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<9>(Val<<1) + 4,
4586                                 true, 2, Inst, Decoder))
4587     Inst.addOperand(MCOperand::createImm(SignExtend32<9>(Val << 1)));
4588   return MCDisassembler::Success;
4589 }
4590 
4591 static DecodeStatus DecodeThumbBLTargetOperand(MCInst &Inst, unsigned Val,
4592                                                uint64_t Address,
4593                                                const void *Decoder) {
4594   // Val is passed in as S:J1:J2:imm10:imm11
4595   // Note no trailing zero after imm11.  Also the J1 and J2 values are from
4596   // the encoded instruction.  So here change to I1 and I2 values via:
4597   // I1 = NOT(J1 EOR S);
4598   // I2 = NOT(J2 EOR S);
4599   // and build the imm32 with one trailing zero as documented:
4600   // imm32 = SignExtend(S:I1:I2:imm10:imm11:'0', 32);
4601   unsigned S = (Val >> 23) & 1;
4602   unsigned J1 = (Val >> 22) & 1;
4603   unsigned J2 = (Val >> 21) & 1;
4604   unsigned I1 = !(J1 ^ S);
4605   unsigned I2 = !(J2 ^ S);
4606   unsigned tmp = (Val & ~0x600000) | (I1 << 22) | (I2 << 21);
4607   int imm32 = SignExtend32<25>(tmp << 1);
4608 
4609   if (!tryAddingSymbolicOperand(Address, Address + imm32 + 4,
4610                                 true, 4, Inst, Decoder))
4611     Inst.addOperand(MCOperand::createImm(imm32));
4612   return MCDisassembler::Success;
4613 }
4614 
4615 static DecodeStatus DecodeMemBarrierOption(MCInst &Inst, unsigned Val,
4616                                    uint64_t Address, const void *Decoder) {
4617   if (Val & ~0xf)
4618     return MCDisassembler::Fail;
4619 
4620   Inst.addOperand(MCOperand::createImm(Val));
4621   return MCDisassembler::Success;
4622 }
4623 
4624 static DecodeStatus DecodeInstSyncBarrierOption(MCInst &Inst, unsigned Val,
4625                                         uint64_t Address, const void *Decoder) {
4626   if (Val & ~0xf)
4627     return MCDisassembler::Fail;
4628 
4629   Inst.addOperand(MCOperand::createImm(Val));
4630   return MCDisassembler::Success;
4631 }
4632 
4633 static DecodeStatus DecodeMSRMask(MCInst &Inst, unsigned Val,
4634                           uint64_t Address, const void *Decoder) {
4635   DecodeStatus S = MCDisassembler::Success;
4636   const FeatureBitset &FeatureBits =
4637     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4638 
4639   if (FeatureBits[ARM::FeatureMClass]) {
4640     unsigned ValLow = Val & 0xff;
4641 
4642     // Validate the SYSm value first.
4643     switch (ValLow) {
4644     case  0: // apsr
4645     case  1: // iapsr
4646     case  2: // eapsr
4647     case  3: // xpsr
4648     case  5: // ipsr
4649     case  6: // epsr
4650     case  7: // iepsr
4651     case  8: // msp
4652     case  9: // psp
4653     case 16: // primask
4654     case 20: // control
4655       break;
4656     case 17: // basepri
4657     case 18: // basepri_max
4658     case 19: // faultmask
4659       if (!(FeatureBits[ARM::HasV7Ops]))
4660         // Values basepri, basepri_max and faultmask are only valid for v7m.
4661         return MCDisassembler::Fail;
4662       break;
4663     case 0x8a: // msplim_ns
4664     case 0x8b: // psplim_ns
4665     case 0x91: // basepri_ns
4666     case 0x93: // faultmask_ns
4667       if (!(FeatureBits[ARM::HasV8MMainlineOps]))
4668         return MCDisassembler::Fail;
4669       LLVM_FALLTHROUGH;
4670     case 10:   // msplim
4671     case 11:   // psplim
4672     case 0x88: // msp_ns
4673     case 0x89: // psp_ns
4674     case 0x90: // primask_ns
4675     case 0x94: // control_ns
4676     case 0x98: // sp_ns
4677       if (!(FeatureBits[ARM::Feature8MSecExt]))
4678         return MCDisassembler::Fail;
4679       break;
4680     default:
4681       // Architecturally defined as unpredictable
4682       S = MCDisassembler::SoftFail;
4683       break;
4684     }
4685 
4686     if (Inst.getOpcode() == ARM::t2MSR_M) {
4687       unsigned Mask = fieldFromInstruction(Val, 10, 2);
4688       if (!(FeatureBits[ARM::HasV7Ops])) {
4689         // The ARMv6-M MSR bits {11-10} can be only 0b10, other values are
4690         // unpredictable.
4691         if (Mask != 2)
4692           S = MCDisassembler::SoftFail;
4693       }
4694       else {
4695         // The ARMv7-M architecture stores an additional 2-bit mask value in
4696         // MSR bits {11-10}. The mask is used only with apsr, iapsr, eapsr and
4697         // xpsr, it has to be 0b10 in other cases. Bit mask{1} indicates if
4698         // the NZCVQ bits should be moved by the instruction. Bit mask{0}
4699         // indicates the move for the GE{3:0} bits, the mask{0} bit can be set
4700         // only if the processor includes the DSP extension.
4701         if (Mask == 0 || (Mask != 2 && ValLow > 3) ||
4702             (!(FeatureBits[ARM::FeatureDSP]) && (Mask & 1)))
4703           S = MCDisassembler::SoftFail;
4704       }
4705     }
4706   } else {
4707     // A/R class
4708     if (Val == 0)
4709       return MCDisassembler::Fail;
4710   }
4711   Inst.addOperand(MCOperand::createImm(Val));
4712   return S;
4713 }
4714 
4715 static DecodeStatus DecodeBankedReg(MCInst &Inst, unsigned Val,
4716                                     uint64_t Address, const void *Decoder) {
4717   unsigned R = fieldFromInstruction(Val, 5, 1);
4718   unsigned SysM = fieldFromInstruction(Val, 0, 5);
4719 
4720   // The table of encodings for these banked registers comes from B9.2.3 of the
4721   // ARM ARM. There are patterns, but nothing regular enough to make this logic
4722   // neater. So by fiat, these values are UNPREDICTABLE:
4723   if (!ARMBankedReg::lookupBankedRegByEncoding((R << 5) | SysM))
4724     return MCDisassembler::Fail;
4725 
4726   Inst.addOperand(MCOperand::createImm(Val));
4727   return MCDisassembler::Success;
4728 }
4729 
4730 static DecodeStatus DecodeDoubleRegLoad(MCInst &Inst, unsigned Insn,
4731                                         uint64_t Address, const void *Decoder) {
4732   DecodeStatus S = MCDisassembler::Success;
4733 
4734   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4735   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4736   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4737 
4738   if (Rn == 0xF)
4739     S = MCDisassembler::SoftFail;
4740 
4741   if (!Check(S, DecodeGPRPairRegisterClass(Inst, Rt, Address, Decoder)))
4742     return MCDisassembler::Fail;
4743   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4744     return MCDisassembler::Fail;
4745   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4746     return MCDisassembler::Fail;
4747 
4748   return S;
4749 }
4750 
4751 static DecodeStatus DecodeDoubleRegStore(MCInst &Inst, unsigned Insn,
4752                                          uint64_t Address,
4753                                          const void *Decoder) {
4754   DecodeStatus S = MCDisassembler::Success;
4755 
4756   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4757   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
4758   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4759   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4760 
4761   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
4762     return MCDisassembler::Fail;
4763 
4764   if (Rn == 0xF || Rd == Rn || Rd == Rt || Rd == Rt+1)
4765     S = MCDisassembler::SoftFail;
4766 
4767   if (!Check(S, DecodeGPRPairRegisterClass(Inst, Rt, Address, Decoder)))
4768     return MCDisassembler::Fail;
4769   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4770     return MCDisassembler::Fail;
4771   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4772     return MCDisassembler::Fail;
4773 
4774   return S;
4775 }
4776 
4777 static DecodeStatus DecodeLDRPreImm(MCInst &Inst, unsigned Insn,
4778                             uint64_t Address, const void *Decoder) {
4779   DecodeStatus S = MCDisassembler::Success;
4780 
4781   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4782   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4783   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4784   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4785   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4786   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4787 
4788   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4789 
4790   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4791     return MCDisassembler::Fail;
4792   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4793     return MCDisassembler::Fail;
4794   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
4795     return MCDisassembler::Fail;
4796   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4797     return MCDisassembler::Fail;
4798 
4799   return S;
4800 }
4801 
4802 static DecodeStatus DecodeLDRPreReg(MCInst &Inst, unsigned Insn,
4803                             uint64_t Address, const void *Decoder) {
4804   DecodeStatus S = MCDisassembler::Success;
4805 
4806   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4807   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4808   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4809   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4810   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4811   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4812   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4813 
4814   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4815   if (Rm == 0xF) S = MCDisassembler::SoftFail;
4816 
4817   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4818     return MCDisassembler::Fail;
4819   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4820     return MCDisassembler::Fail;
4821   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
4822     return MCDisassembler::Fail;
4823   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4824     return MCDisassembler::Fail;
4825 
4826   return S;
4827 }
4828 
4829 static DecodeStatus DecodeSTRPreImm(MCInst &Inst, unsigned Insn,
4830                             uint64_t Address, const void *Decoder) {
4831   DecodeStatus S = MCDisassembler::Success;
4832 
4833   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4834   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4835   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4836   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4837   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4838   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4839 
4840   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4841 
4842   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4843     return MCDisassembler::Fail;
4844   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4845     return MCDisassembler::Fail;
4846   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
4847     return MCDisassembler::Fail;
4848   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4849     return MCDisassembler::Fail;
4850 
4851   return S;
4852 }
4853 
4854 static DecodeStatus DecodeSTRPreReg(MCInst &Inst, unsigned Insn,
4855                             uint64_t Address, const void *Decoder) {
4856   DecodeStatus S = MCDisassembler::Success;
4857 
4858   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4859   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4860   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4861   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4862   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4863   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4864 
4865   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4866 
4867   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4868     return MCDisassembler::Fail;
4869   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4870     return MCDisassembler::Fail;
4871   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
4872     return MCDisassembler::Fail;
4873   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4874     return MCDisassembler::Fail;
4875 
4876   return S;
4877 }
4878 
4879 static DecodeStatus DecodeVLD1LN(MCInst &Inst, unsigned Insn,
4880                          uint64_t Address, const void *Decoder) {
4881   DecodeStatus S = MCDisassembler::Success;
4882 
4883   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4884   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4885   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4886   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4887   unsigned size = fieldFromInstruction(Insn, 10, 2);
4888 
4889   unsigned align = 0;
4890   unsigned index = 0;
4891   switch (size) {
4892     default:
4893       return MCDisassembler::Fail;
4894     case 0:
4895       if (fieldFromInstruction(Insn, 4, 1))
4896         return MCDisassembler::Fail; // UNDEFINED
4897       index = fieldFromInstruction(Insn, 5, 3);
4898       break;
4899     case 1:
4900       if (fieldFromInstruction(Insn, 5, 1))
4901         return MCDisassembler::Fail; // UNDEFINED
4902       index = fieldFromInstruction(Insn, 6, 2);
4903       if (fieldFromInstruction(Insn, 4, 1))
4904         align = 2;
4905       break;
4906     case 2:
4907       if (fieldFromInstruction(Insn, 6, 1))
4908         return MCDisassembler::Fail; // UNDEFINED
4909       index = fieldFromInstruction(Insn, 7, 1);
4910 
4911       switch (fieldFromInstruction(Insn, 4, 2)) {
4912         case 0 :
4913           align = 0; break;
4914         case 3:
4915           align = 4; break;
4916         default:
4917           return MCDisassembler::Fail;
4918       }
4919       break;
4920   }
4921 
4922   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4923     return MCDisassembler::Fail;
4924   if (Rm != 0xF) { // Writeback
4925     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4926       return MCDisassembler::Fail;
4927   }
4928   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4929     return MCDisassembler::Fail;
4930   Inst.addOperand(MCOperand::createImm(align));
4931   if (Rm != 0xF) {
4932     if (Rm != 0xD) {
4933       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4934         return MCDisassembler::Fail;
4935     } else
4936       Inst.addOperand(MCOperand::createReg(0));
4937   }
4938 
4939   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4940     return MCDisassembler::Fail;
4941   Inst.addOperand(MCOperand::createImm(index));
4942 
4943   return S;
4944 }
4945 
4946 static DecodeStatus DecodeVST1LN(MCInst &Inst, unsigned Insn,
4947                          uint64_t Address, const void *Decoder) {
4948   DecodeStatus S = MCDisassembler::Success;
4949 
4950   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4951   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4952   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4953   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4954   unsigned size = fieldFromInstruction(Insn, 10, 2);
4955 
4956   unsigned align = 0;
4957   unsigned index = 0;
4958   switch (size) {
4959     default:
4960       return MCDisassembler::Fail;
4961     case 0:
4962       if (fieldFromInstruction(Insn, 4, 1))
4963         return MCDisassembler::Fail; // UNDEFINED
4964       index = fieldFromInstruction(Insn, 5, 3);
4965       break;
4966     case 1:
4967       if (fieldFromInstruction(Insn, 5, 1))
4968         return MCDisassembler::Fail; // UNDEFINED
4969       index = fieldFromInstruction(Insn, 6, 2);
4970       if (fieldFromInstruction(Insn, 4, 1))
4971         align = 2;
4972       break;
4973     case 2:
4974       if (fieldFromInstruction(Insn, 6, 1))
4975         return MCDisassembler::Fail; // UNDEFINED
4976       index = fieldFromInstruction(Insn, 7, 1);
4977 
4978       switch (fieldFromInstruction(Insn, 4, 2)) {
4979         case 0:
4980           align = 0; break;
4981         case 3:
4982           align = 4; break;
4983         default:
4984           return MCDisassembler::Fail;
4985       }
4986       break;
4987   }
4988 
4989   if (Rm != 0xF) { // Writeback
4990     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4991     return MCDisassembler::Fail;
4992   }
4993   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4994     return MCDisassembler::Fail;
4995   Inst.addOperand(MCOperand::createImm(align));
4996   if (Rm != 0xF) {
4997     if (Rm != 0xD) {
4998       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4999     return MCDisassembler::Fail;
5000     } else
5001       Inst.addOperand(MCOperand::createReg(0));
5002   }
5003 
5004   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5005     return MCDisassembler::Fail;
5006   Inst.addOperand(MCOperand::createImm(index));
5007 
5008   return S;
5009 }
5010 
5011 static DecodeStatus DecodeVLD2LN(MCInst &Inst, unsigned Insn,
5012                          uint64_t Address, const void *Decoder) {
5013   DecodeStatus S = MCDisassembler::Success;
5014 
5015   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5016   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5017   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5018   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5019   unsigned size = fieldFromInstruction(Insn, 10, 2);
5020 
5021   unsigned align = 0;
5022   unsigned index = 0;
5023   unsigned inc = 1;
5024   switch (size) {
5025     default:
5026       return MCDisassembler::Fail;
5027     case 0:
5028       index = fieldFromInstruction(Insn, 5, 3);
5029       if (fieldFromInstruction(Insn, 4, 1))
5030         align = 2;
5031       break;
5032     case 1:
5033       index = fieldFromInstruction(Insn, 6, 2);
5034       if (fieldFromInstruction(Insn, 4, 1))
5035         align = 4;
5036       if (fieldFromInstruction(Insn, 5, 1))
5037         inc = 2;
5038       break;
5039     case 2:
5040       if (fieldFromInstruction(Insn, 5, 1))
5041         return MCDisassembler::Fail; // UNDEFINED
5042       index = fieldFromInstruction(Insn, 7, 1);
5043       if (fieldFromInstruction(Insn, 4, 1) != 0)
5044         align = 8;
5045       if (fieldFromInstruction(Insn, 6, 1))
5046         inc = 2;
5047       break;
5048   }
5049 
5050   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5051     return MCDisassembler::Fail;
5052   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5053     return MCDisassembler::Fail;
5054   if (Rm != 0xF) { // Writeback
5055     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5056       return MCDisassembler::Fail;
5057   }
5058   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5059     return MCDisassembler::Fail;
5060   Inst.addOperand(MCOperand::createImm(align));
5061   if (Rm != 0xF) {
5062     if (Rm != 0xD) {
5063       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5064         return MCDisassembler::Fail;
5065     } else
5066       Inst.addOperand(MCOperand::createReg(0));
5067   }
5068 
5069   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5070     return MCDisassembler::Fail;
5071   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5072     return MCDisassembler::Fail;
5073   Inst.addOperand(MCOperand::createImm(index));
5074 
5075   return S;
5076 }
5077 
5078 static DecodeStatus DecodeVST2LN(MCInst &Inst, unsigned Insn,
5079                          uint64_t Address, const void *Decoder) {
5080   DecodeStatus S = MCDisassembler::Success;
5081 
5082   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5083   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5084   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5085   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5086   unsigned size = fieldFromInstruction(Insn, 10, 2);
5087 
5088   unsigned align = 0;
5089   unsigned index = 0;
5090   unsigned inc = 1;
5091   switch (size) {
5092     default:
5093       return MCDisassembler::Fail;
5094     case 0:
5095       index = fieldFromInstruction(Insn, 5, 3);
5096       if (fieldFromInstruction(Insn, 4, 1))
5097         align = 2;
5098       break;
5099     case 1:
5100       index = fieldFromInstruction(Insn, 6, 2);
5101       if (fieldFromInstruction(Insn, 4, 1))
5102         align = 4;
5103       if (fieldFromInstruction(Insn, 5, 1))
5104         inc = 2;
5105       break;
5106     case 2:
5107       if (fieldFromInstruction(Insn, 5, 1))
5108         return MCDisassembler::Fail; // UNDEFINED
5109       index = fieldFromInstruction(Insn, 7, 1);
5110       if (fieldFromInstruction(Insn, 4, 1) != 0)
5111         align = 8;
5112       if (fieldFromInstruction(Insn, 6, 1))
5113         inc = 2;
5114       break;
5115   }
5116 
5117   if (Rm != 0xF) { // Writeback
5118     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5119       return MCDisassembler::Fail;
5120   }
5121   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5122     return MCDisassembler::Fail;
5123   Inst.addOperand(MCOperand::createImm(align));
5124   if (Rm != 0xF) {
5125     if (Rm != 0xD) {
5126       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5127         return MCDisassembler::Fail;
5128     } else
5129       Inst.addOperand(MCOperand::createReg(0));
5130   }
5131 
5132   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5133     return MCDisassembler::Fail;
5134   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5135     return MCDisassembler::Fail;
5136   Inst.addOperand(MCOperand::createImm(index));
5137 
5138   return S;
5139 }
5140 
5141 static DecodeStatus DecodeVLD3LN(MCInst &Inst, unsigned Insn,
5142                          uint64_t Address, const void *Decoder) {
5143   DecodeStatus S = MCDisassembler::Success;
5144 
5145   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5146   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5147   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5148   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5149   unsigned size = fieldFromInstruction(Insn, 10, 2);
5150 
5151   unsigned align = 0;
5152   unsigned index = 0;
5153   unsigned inc = 1;
5154   switch (size) {
5155     default:
5156       return MCDisassembler::Fail;
5157     case 0:
5158       if (fieldFromInstruction(Insn, 4, 1))
5159         return MCDisassembler::Fail; // UNDEFINED
5160       index = fieldFromInstruction(Insn, 5, 3);
5161       break;
5162     case 1:
5163       if (fieldFromInstruction(Insn, 4, 1))
5164         return MCDisassembler::Fail; // UNDEFINED
5165       index = fieldFromInstruction(Insn, 6, 2);
5166       if (fieldFromInstruction(Insn, 5, 1))
5167         inc = 2;
5168       break;
5169     case 2:
5170       if (fieldFromInstruction(Insn, 4, 2))
5171         return MCDisassembler::Fail; // UNDEFINED
5172       index = fieldFromInstruction(Insn, 7, 1);
5173       if (fieldFromInstruction(Insn, 6, 1))
5174         inc = 2;
5175       break;
5176   }
5177 
5178   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5179     return MCDisassembler::Fail;
5180   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5181     return MCDisassembler::Fail;
5182   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5183     return MCDisassembler::Fail;
5184 
5185   if (Rm != 0xF) { // Writeback
5186     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5187     return MCDisassembler::Fail;
5188   }
5189   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5190     return MCDisassembler::Fail;
5191   Inst.addOperand(MCOperand::createImm(align));
5192   if (Rm != 0xF) {
5193     if (Rm != 0xD) {
5194       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5195     return MCDisassembler::Fail;
5196     } else
5197       Inst.addOperand(MCOperand::createReg(0));
5198   }
5199 
5200   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5201     return MCDisassembler::Fail;
5202   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5203     return MCDisassembler::Fail;
5204   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5205     return MCDisassembler::Fail;
5206   Inst.addOperand(MCOperand::createImm(index));
5207 
5208   return S;
5209 }
5210 
5211 static DecodeStatus DecodeVST3LN(MCInst &Inst, unsigned Insn,
5212                          uint64_t Address, const void *Decoder) {
5213   DecodeStatus S = MCDisassembler::Success;
5214 
5215   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5216   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5217   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5218   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5219   unsigned size = fieldFromInstruction(Insn, 10, 2);
5220 
5221   unsigned align = 0;
5222   unsigned index = 0;
5223   unsigned inc = 1;
5224   switch (size) {
5225     default:
5226       return MCDisassembler::Fail;
5227     case 0:
5228       if (fieldFromInstruction(Insn, 4, 1))
5229         return MCDisassembler::Fail; // UNDEFINED
5230       index = fieldFromInstruction(Insn, 5, 3);
5231       break;
5232     case 1:
5233       if (fieldFromInstruction(Insn, 4, 1))
5234         return MCDisassembler::Fail; // UNDEFINED
5235       index = fieldFromInstruction(Insn, 6, 2);
5236       if (fieldFromInstruction(Insn, 5, 1))
5237         inc = 2;
5238       break;
5239     case 2:
5240       if (fieldFromInstruction(Insn, 4, 2))
5241         return MCDisassembler::Fail; // UNDEFINED
5242       index = fieldFromInstruction(Insn, 7, 1);
5243       if (fieldFromInstruction(Insn, 6, 1))
5244         inc = 2;
5245       break;
5246   }
5247 
5248   if (Rm != 0xF) { // Writeback
5249     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5250     return MCDisassembler::Fail;
5251   }
5252   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5253     return MCDisassembler::Fail;
5254   Inst.addOperand(MCOperand::createImm(align));
5255   if (Rm != 0xF) {
5256     if (Rm != 0xD) {
5257       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5258     return MCDisassembler::Fail;
5259     } else
5260       Inst.addOperand(MCOperand::createReg(0));
5261   }
5262 
5263   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5264     return MCDisassembler::Fail;
5265   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5266     return MCDisassembler::Fail;
5267   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5268     return MCDisassembler::Fail;
5269   Inst.addOperand(MCOperand::createImm(index));
5270 
5271   return S;
5272 }
5273 
5274 static DecodeStatus DecodeVLD4LN(MCInst &Inst, unsigned Insn,
5275                          uint64_t Address, const void *Decoder) {
5276   DecodeStatus S = MCDisassembler::Success;
5277 
5278   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5279   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5280   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5281   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5282   unsigned size = fieldFromInstruction(Insn, 10, 2);
5283 
5284   unsigned align = 0;
5285   unsigned index = 0;
5286   unsigned inc = 1;
5287   switch (size) {
5288     default:
5289       return MCDisassembler::Fail;
5290     case 0:
5291       if (fieldFromInstruction(Insn, 4, 1))
5292         align = 4;
5293       index = fieldFromInstruction(Insn, 5, 3);
5294       break;
5295     case 1:
5296       if (fieldFromInstruction(Insn, 4, 1))
5297         align = 8;
5298       index = fieldFromInstruction(Insn, 6, 2);
5299       if (fieldFromInstruction(Insn, 5, 1))
5300         inc = 2;
5301       break;
5302     case 2:
5303       switch (fieldFromInstruction(Insn, 4, 2)) {
5304         case 0:
5305           align = 0; break;
5306         case 3:
5307           return MCDisassembler::Fail;
5308         default:
5309           align = 4 << fieldFromInstruction(Insn, 4, 2); break;
5310       }
5311 
5312       index = fieldFromInstruction(Insn, 7, 1);
5313       if (fieldFromInstruction(Insn, 6, 1))
5314         inc = 2;
5315       break;
5316   }
5317 
5318   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5319     return MCDisassembler::Fail;
5320   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5321     return MCDisassembler::Fail;
5322   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5323     return MCDisassembler::Fail;
5324   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5325     return MCDisassembler::Fail;
5326 
5327   if (Rm != 0xF) { // Writeback
5328     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5329       return MCDisassembler::Fail;
5330   }
5331   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5332     return MCDisassembler::Fail;
5333   Inst.addOperand(MCOperand::createImm(align));
5334   if (Rm != 0xF) {
5335     if (Rm != 0xD) {
5336       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5337         return MCDisassembler::Fail;
5338     } else
5339       Inst.addOperand(MCOperand::createReg(0));
5340   }
5341 
5342   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5343     return MCDisassembler::Fail;
5344   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5345     return MCDisassembler::Fail;
5346   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5347     return MCDisassembler::Fail;
5348   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5349     return MCDisassembler::Fail;
5350   Inst.addOperand(MCOperand::createImm(index));
5351 
5352   return S;
5353 }
5354 
5355 static DecodeStatus DecodeVST4LN(MCInst &Inst, unsigned Insn,
5356                          uint64_t Address, const void *Decoder) {
5357   DecodeStatus S = MCDisassembler::Success;
5358 
5359   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5360   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5361   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5362   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5363   unsigned size = fieldFromInstruction(Insn, 10, 2);
5364 
5365   unsigned align = 0;
5366   unsigned index = 0;
5367   unsigned inc = 1;
5368   switch (size) {
5369     default:
5370       return MCDisassembler::Fail;
5371     case 0:
5372       if (fieldFromInstruction(Insn, 4, 1))
5373         align = 4;
5374       index = fieldFromInstruction(Insn, 5, 3);
5375       break;
5376     case 1:
5377       if (fieldFromInstruction(Insn, 4, 1))
5378         align = 8;
5379       index = fieldFromInstruction(Insn, 6, 2);
5380       if (fieldFromInstruction(Insn, 5, 1))
5381         inc = 2;
5382       break;
5383     case 2:
5384       switch (fieldFromInstruction(Insn, 4, 2)) {
5385         case 0:
5386           align = 0; break;
5387         case 3:
5388           return MCDisassembler::Fail;
5389         default:
5390           align = 4 << fieldFromInstruction(Insn, 4, 2); break;
5391       }
5392 
5393       index = fieldFromInstruction(Insn, 7, 1);
5394       if (fieldFromInstruction(Insn, 6, 1))
5395         inc = 2;
5396       break;
5397   }
5398 
5399   if (Rm != 0xF) { // Writeback
5400     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5401     return MCDisassembler::Fail;
5402   }
5403   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5404     return MCDisassembler::Fail;
5405   Inst.addOperand(MCOperand::createImm(align));
5406   if (Rm != 0xF) {
5407     if (Rm != 0xD) {
5408       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5409     return MCDisassembler::Fail;
5410     } else
5411       Inst.addOperand(MCOperand::createReg(0));
5412   }
5413 
5414   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5415     return MCDisassembler::Fail;
5416   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5417     return MCDisassembler::Fail;
5418   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5419     return MCDisassembler::Fail;
5420   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5421     return MCDisassembler::Fail;
5422   Inst.addOperand(MCOperand::createImm(index));
5423 
5424   return S;
5425 }
5426 
5427 static DecodeStatus DecodeVMOVSRR(MCInst &Inst, unsigned Insn,
5428                                   uint64_t Address, const void *Decoder) {
5429   DecodeStatus S = MCDisassembler::Success;
5430   unsigned Rt  = fieldFromInstruction(Insn, 12, 4);
5431   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
5432   unsigned Rm  = fieldFromInstruction(Insn,  5, 1);
5433   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5434   Rm |= fieldFromInstruction(Insn, 0, 4) << 1;
5435 
5436   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
5437     S = MCDisassembler::SoftFail;
5438 
5439   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
5440     return MCDisassembler::Fail;
5441   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
5442     return MCDisassembler::Fail;
5443   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
5444     return MCDisassembler::Fail;
5445   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
5446     return MCDisassembler::Fail;
5447   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5448     return MCDisassembler::Fail;
5449 
5450   return S;
5451 }
5452 
5453 static DecodeStatus DecodeVMOVRRS(MCInst &Inst, unsigned Insn,
5454                                   uint64_t Address, const void *Decoder) {
5455   DecodeStatus S = MCDisassembler::Success;
5456   unsigned Rt  = fieldFromInstruction(Insn, 12, 4);
5457   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
5458   unsigned Rm  = fieldFromInstruction(Insn,  5, 1);
5459   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5460   Rm |= fieldFromInstruction(Insn, 0, 4) << 1;
5461 
5462   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
5463     S = MCDisassembler::SoftFail;
5464 
5465   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
5466     return MCDisassembler::Fail;
5467   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
5468     return MCDisassembler::Fail;
5469   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
5470     return MCDisassembler::Fail;
5471   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
5472     return MCDisassembler::Fail;
5473   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5474     return MCDisassembler::Fail;
5475 
5476   return S;
5477 }
5478 
5479 static DecodeStatus DecodeIT(MCInst &Inst, unsigned Insn,
5480                              uint64_t Address, const void *Decoder) {
5481   DecodeStatus S = MCDisassembler::Success;
5482   unsigned pred = fieldFromInstruction(Insn, 4, 4);
5483   unsigned mask = fieldFromInstruction(Insn, 0, 4);
5484 
5485   if (pred == 0xF) {
5486     pred = 0xE;
5487     S = MCDisassembler::SoftFail;
5488   }
5489 
5490   if (mask == 0x0)
5491     return MCDisassembler::Fail;
5492 
5493   // IT masks are encoded as a sequence of replacement low-order bits
5494   // for the condition code. So if the low bit of the starting
5495   // condition code is 1, then we have to flip all the bits above the
5496   // terminating bit (which is the lowest 1 bit).
5497   if (pred & 1) {
5498     unsigned LowBit = mask & -mask;
5499     unsigned BitsAboveLowBit = 0xF & (-LowBit << 1);
5500     mask ^= BitsAboveLowBit;
5501   }
5502 
5503   Inst.addOperand(MCOperand::createImm(pred));
5504   Inst.addOperand(MCOperand::createImm(mask));
5505   return S;
5506 }
5507 
5508 static DecodeStatus
5509 DecodeT2LDRDPreInstruction(MCInst &Inst, unsigned Insn,
5510                            uint64_t Address, const void *Decoder) {
5511   DecodeStatus S = MCDisassembler::Success;
5512 
5513   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5514   unsigned Rt2 = fieldFromInstruction(Insn, 8, 4);
5515   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5516   unsigned addr = fieldFromInstruction(Insn, 0, 8);
5517   unsigned W = fieldFromInstruction(Insn, 21, 1);
5518   unsigned U = fieldFromInstruction(Insn, 23, 1);
5519   unsigned P = fieldFromInstruction(Insn, 24, 1);
5520   bool writeback = (W == 1) | (P == 0);
5521 
5522   addr |= (U << 8) | (Rn << 9);
5523 
5524   if (writeback && (Rn == Rt || Rn == Rt2))
5525     Check(S, MCDisassembler::SoftFail);
5526   if (Rt == Rt2)
5527     Check(S, MCDisassembler::SoftFail);
5528 
5529   // Rt
5530   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
5531     return MCDisassembler::Fail;
5532   // Rt2
5533   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
5534     return MCDisassembler::Fail;
5535   // Writeback operand
5536   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
5537     return MCDisassembler::Fail;
5538   // addr
5539   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
5540     return MCDisassembler::Fail;
5541 
5542   return S;
5543 }
5544 
5545 static DecodeStatus
5546 DecodeT2STRDPreInstruction(MCInst &Inst, unsigned Insn,
5547                            uint64_t Address, const void *Decoder) {
5548   DecodeStatus S = MCDisassembler::Success;
5549 
5550   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5551   unsigned Rt2 = fieldFromInstruction(Insn, 8, 4);
5552   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5553   unsigned addr = fieldFromInstruction(Insn, 0, 8);
5554   unsigned W = fieldFromInstruction(Insn, 21, 1);
5555   unsigned U = fieldFromInstruction(Insn, 23, 1);
5556   unsigned P = fieldFromInstruction(Insn, 24, 1);
5557   bool writeback = (W == 1) | (P == 0);
5558 
5559   addr |= (U << 8) | (Rn << 9);
5560 
5561   if (writeback && (Rn == Rt || Rn == Rt2))
5562     Check(S, MCDisassembler::SoftFail);
5563 
5564   // Writeback operand
5565   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
5566     return MCDisassembler::Fail;
5567   // Rt
5568   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
5569     return MCDisassembler::Fail;
5570   // Rt2
5571   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
5572     return MCDisassembler::Fail;
5573   // addr
5574   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
5575     return MCDisassembler::Fail;
5576 
5577   return S;
5578 }
5579 
5580 static DecodeStatus DecodeT2Adr(MCInst &Inst, uint32_t Insn,
5581                                 uint64_t Address, const void *Decoder) {
5582   unsigned sign1 = fieldFromInstruction(Insn, 21, 1);
5583   unsigned sign2 = fieldFromInstruction(Insn, 23, 1);
5584   if (sign1 != sign2) return MCDisassembler::Fail;
5585 
5586   unsigned Val = fieldFromInstruction(Insn, 0, 8);
5587   Val |= fieldFromInstruction(Insn, 12, 3) << 8;
5588   Val |= fieldFromInstruction(Insn, 26, 1) << 11;
5589   Val |= sign1 << 12;
5590   Inst.addOperand(MCOperand::createImm(SignExtend32<13>(Val)));
5591 
5592   return MCDisassembler::Success;
5593 }
5594 
5595 static DecodeStatus DecodeT2ShifterImmOperand(MCInst &Inst, uint32_t Val,
5596                                               uint64_t Address,
5597                                               const void *Decoder) {
5598   DecodeStatus S = MCDisassembler::Success;
5599 
5600   // Shift of "asr #32" is not allowed in Thumb2 mode.
5601   if (Val == 0x20) S = MCDisassembler::Fail;
5602   Inst.addOperand(MCOperand::createImm(Val));
5603   return S;
5604 }
5605 
5606 static DecodeStatus DecodeSwap(MCInst &Inst, unsigned Insn,
5607                                uint64_t Address, const void *Decoder) {
5608   unsigned Rt   = fieldFromInstruction(Insn, 12, 4);
5609   unsigned Rt2  = fieldFromInstruction(Insn, 0,  4);
5610   unsigned Rn   = fieldFromInstruction(Insn, 16, 4);
5611   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5612 
5613   if (pred == 0xF)
5614     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
5615 
5616   DecodeStatus S = MCDisassembler::Success;
5617 
5618   if (Rt == Rn || Rn == Rt2)
5619     S = MCDisassembler::SoftFail;
5620 
5621   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5622     return MCDisassembler::Fail;
5623   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5624     return MCDisassembler::Fail;
5625   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
5626     return MCDisassembler::Fail;
5627   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5628     return MCDisassembler::Fail;
5629 
5630   return S;
5631 }
5632 
5633 static DecodeStatus DecodeVCVTD(MCInst &Inst, unsigned Insn,
5634                                 uint64_t Address, const void *Decoder) {
5635   const FeatureBitset &featureBits =
5636       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5637   bool hasFullFP16 = featureBits[ARM::FeatureFullFP16];
5638 
5639   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5640   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5641   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5642   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5643   unsigned imm = fieldFromInstruction(Insn, 16, 6);
5644   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
5645   unsigned op = fieldFromInstruction(Insn, 5, 1);
5646 
5647   DecodeStatus S = MCDisassembler::Success;
5648 
5649   // If the top 3 bits of imm are clear, this is a VMOV (immediate)
5650   if (!(imm & 0x38)) {
5651     if (cmode == 0xF) {
5652       if (op == 1) return MCDisassembler::Fail;
5653       Inst.setOpcode(ARM::VMOVv2f32);
5654     }
5655     if (hasFullFP16) {
5656       if (cmode == 0xE) {
5657         if (op == 1) {
5658           Inst.setOpcode(ARM::VMOVv1i64);
5659         } else {
5660           Inst.setOpcode(ARM::VMOVv8i8);
5661         }
5662       }
5663       if (cmode == 0xD) {
5664         if (op == 1) {
5665           Inst.setOpcode(ARM::VMVNv2i32);
5666         } else {
5667           Inst.setOpcode(ARM::VMOVv2i32);
5668         }
5669       }
5670       if (cmode == 0xC) {
5671         if (op == 1) {
5672           Inst.setOpcode(ARM::VMVNv2i32);
5673         } else {
5674           Inst.setOpcode(ARM::VMOVv2i32);
5675         }
5676       }
5677     }
5678     return DecodeVMOVModImmInstruction(Inst, Insn, Address, Decoder);
5679   }
5680 
5681   if (!(imm & 0x20)) return MCDisassembler::Fail;
5682 
5683   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
5684     return MCDisassembler::Fail;
5685   if (!Check(S, DecodeDPRRegisterClass(Inst, Vm, Address, Decoder)))
5686     return MCDisassembler::Fail;
5687   Inst.addOperand(MCOperand::createImm(64 - imm));
5688 
5689   return S;
5690 }
5691 
5692 static DecodeStatus DecodeVCVTQ(MCInst &Inst, unsigned Insn,
5693                                 uint64_t Address, const void *Decoder) {
5694   const FeatureBitset &featureBits =
5695       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5696   bool hasFullFP16 = featureBits[ARM::FeatureFullFP16];
5697 
5698   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5699   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5700   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5701   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5702   unsigned imm = fieldFromInstruction(Insn, 16, 6);
5703   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
5704   unsigned op = fieldFromInstruction(Insn, 5, 1);
5705 
5706   DecodeStatus S = MCDisassembler::Success;
5707 
5708   // If the top 3 bits of imm are clear, this is a VMOV (immediate)
5709   if (!(imm & 0x38)) {
5710     if (cmode == 0xF) {
5711       if (op == 1) return MCDisassembler::Fail;
5712       Inst.setOpcode(ARM::VMOVv4f32);
5713     }
5714     if (hasFullFP16) {
5715       if (cmode == 0xE) {
5716         if (op == 1) {
5717           Inst.setOpcode(ARM::VMOVv2i64);
5718         } else {
5719           Inst.setOpcode(ARM::VMOVv16i8);
5720         }
5721       }
5722       if (cmode == 0xD) {
5723         if (op == 1) {
5724           Inst.setOpcode(ARM::VMVNv4i32);
5725         } else {
5726           Inst.setOpcode(ARM::VMOVv4i32);
5727         }
5728       }
5729       if (cmode == 0xC) {
5730         if (op == 1) {
5731           Inst.setOpcode(ARM::VMVNv4i32);
5732         } else {
5733           Inst.setOpcode(ARM::VMOVv4i32);
5734         }
5735       }
5736     }
5737     return DecodeVMOVModImmInstruction(Inst, Insn, Address, Decoder);
5738   }
5739 
5740   if (!(imm & 0x20)) return MCDisassembler::Fail;
5741 
5742   if (!Check(S, DecodeQPRRegisterClass(Inst, Vd, Address, Decoder)))
5743     return MCDisassembler::Fail;
5744   if (!Check(S, DecodeQPRRegisterClass(Inst, Vm, Address, Decoder)))
5745     return MCDisassembler::Fail;
5746   Inst.addOperand(MCOperand::createImm(64 - imm));
5747 
5748   return S;
5749 }
5750 
5751 static DecodeStatus DecodeNEONComplexLane64Instruction(MCInst &Inst,
5752                                                        unsigned Insn,
5753                                                        uint64_t Address,
5754                                                        const void *Decoder) {
5755   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5756   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5757   unsigned Vn = (fieldFromInstruction(Insn, 16, 4) << 0);
5758   Vn |= (fieldFromInstruction(Insn, 7, 1) << 4);
5759   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5760   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5761   unsigned q = (fieldFromInstruction(Insn, 6, 1) << 0);
5762   unsigned rotate = (fieldFromInstruction(Insn, 20, 2) << 0);
5763 
5764   DecodeStatus S = MCDisassembler::Success;
5765 
5766   auto DestRegDecoder = q ? DecodeQPRRegisterClass : DecodeDPRRegisterClass;
5767 
5768   if (!Check(S, DestRegDecoder(Inst, Vd, Address, Decoder)))
5769     return MCDisassembler::Fail;
5770   if (!Check(S, DestRegDecoder(Inst, Vd, Address, Decoder)))
5771     return MCDisassembler::Fail;
5772   if (!Check(S, DestRegDecoder(Inst, Vn, Address, Decoder)))
5773     return MCDisassembler::Fail;
5774   if (!Check(S, DecodeDPRRegisterClass(Inst, Vm, Address, Decoder)))
5775     return MCDisassembler::Fail;
5776   // The lane index does not have any bits in the encoding, because it can only
5777   // be 0.
5778   Inst.addOperand(MCOperand::createImm(0));
5779   Inst.addOperand(MCOperand::createImm(rotate));
5780 
5781   return S;
5782 }
5783 
5784 static DecodeStatus DecodeLDR(MCInst &Inst, unsigned Val,
5785                                 uint64_t Address, const void *Decoder) {
5786   DecodeStatus S = MCDisassembler::Success;
5787 
5788   unsigned Rn = fieldFromInstruction(Val, 16, 4);
5789   unsigned Rt = fieldFromInstruction(Val, 12, 4);
5790   unsigned Rm = fieldFromInstruction(Val, 0, 4);
5791   Rm |= (fieldFromInstruction(Val, 23, 1) << 4);
5792   unsigned Cond = fieldFromInstruction(Val, 28, 4);
5793 
5794   if (fieldFromInstruction(Val, 8, 4) != 0 || Rn == Rt)
5795     S = MCDisassembler::SoftFail;
5796 
5797   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5798     return MCDisassembler::Fail;
5799   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
5800     return MCDisassembler::Fail;
5801   if (!Check(S, DecodeAddrMode7Operand(Inst, Rn, Address, Decoder)))
5802     return MCDisassembler::Fail;
5803   if (!Check(S, DecodePostIdxReg(Inst, Rm, Address, Decoder)))
5804     return MCDisassembler::Fail;
5805   if (!Check(S, DecodePredicateOperand(Inst, Cond, Address, Decoder)))
5806     return MCDisassembler::Fail;
5807 
5808   return S;
5809 }
5810 
5811 static DecodeStatus DecoderForMRRC2AndMCRR2(MCInst &Inst, unsigned Val,
5812                                             uint64_t Address, const void *Decoder) {
5813   DecodeStatus S = MCDisassembler::Success;
5814 
5815   unsigned CRm = fieldFromInstruction(Val, 0, 4);
5816   unsigned opc1 = fieldFromInstruction(Val, 4, 4);
5817   unsigned cop = fieldFromInstruction(Val, 8, 4);
5818   unsigned Rt = fieldFromInstruction(Val, 12, 4);
5819   unsigned Rt2 = fieldFromInstruction(Val, 16, 4);
5820 
5821   if ((cop & ~0x1) == 0xa)
5822     return MCDisassembler::Fail;
5823 
5824   if (Rt == Rt2)
5825     S = MCDisassembler::SoftFail;
5826 
5827   // We have to check if the instruction is MRRC2
5828   // or MCRR2 when constructing the operands for
5829   // Inst. Reason is because MRRC2 stores to two
5830   // registers so it's tablegen desc has has two
5831   // outputs whereas MCRR doesn't store to any
5832   // registers so all of it's operands are listed
5833   // as inputs, therefore the operand order for
5834   // MRRC2 needs to be [Rt, Rt2, cop, opc1, CRm]
5835   // and MCRR2 operand order is [cop, opc1, Rt, Rt2, CRm]
5836 
5837   if (Inst.getOpcode() == ARM::MRRC2) {
5838     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5839       return MCDisassembler::Fail;
5840     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5841       return MCDisassembler::Fail;
5842   }
5843   Inst.addOperand(MCOperand::createImm(cop));
5844   Inst.addOperand(MCOperand::createImm(opc1));
5845   if (Inst.getOpcode() == ARM::MCRR2) {
5846     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5847       return MCDisassembler::Fail;
5848     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5849       return MCDisassembler::Fail;
5850   }
5851   Inst.addOperand(MCOperand::createImm(CRm));
5852 
5853   return S;
5854 }
5855 
5856 static DecodeStatus DecodeForVMRSandVMSR(MCInst &Inst, unsigned Val,
5857                                          uint64_t Address,
5858                                          const void *Decoder) {
5859   const FeatureBitset &featureBits =
5860       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5861   DecodeStatus S = MCDisassembler::Success;
5862 
5863   // Add explicit operand for the destination sysreg, for cases where
5864   // we have to model it for code generation purposes.
5865   switch (Inst.getOpcode()) {
5866   case ARM::VMSR_FPSCR_NZCVQC:
5867     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
5868     break;
5869   case ARM::VMSR_P0:
5870     Inst.addOperand(MCOperand::createReg(ARM::VPR));
5871     break;
5872   }
5873 
5874   if (Inst.getOpcode() != ARM::FMSTAT) {
5875     unsigned Rt = fieldFromInstruction(Val, 12, 4);
5876 
5877     if (featureBits[ARM::ModeThumb] && !featureBits[ARM::HasV8Ops]) {
5878       if (Rt == 13 || Rt == 15)
5879         S = MCDisassembler::SoftFail;
5880       Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder));
5881     } else
5882       Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder));
5883   }
5884 
5885   // Add explicit operand for the source sysreg, similarly to above.
5886   switch (Inst.getOpcode()) {
5887   case ARM::VMRS_FPSCR_NZCVQC:
5888     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
5889     break;
5890   case ARM::VMRS_P0:
5891     Inst.addOperand(MCOperand::createReg(ARM::VPR));
5892     break;
5893   }
5894 
5895   if (featureBits[ARM::ModeThumb]) {
5896     Inst.addOperand(MCOperand::createImm(ARMCC::AL));
5897     Inst.addOperand(MCOperand::createReg(0));
5898   } else {
5899     unsigned pred = fieldFromInstruction(Val, 28, 4);
5900     if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5901       return MCDisassembler::Fail;
5902   }
5903 
5904   return S;
5905 }
5906 
5907 template <bool isSigned, bool isNeg, bool zeroPermitted, int size>
5908 static DecodeStatus DecodeBFLabelOperand(MCInst &Inst, unsigned Val,
5909                                          uint64_t Address,
5910                                          const void *Decoder) {
5911   DecodeStatus S = MCDisassembler::Success;
5912   if (Val == 0 && !zeroPermitted)
5913     S = MCDisassembler::Fail;
5914 
5915   uint64_t DecVal;
5916   if (isSigned)
5917     DecVal = SignExtend32<size + 1>(Val << 1);
5918   else
5919     DecVal = (Val << 1);
5920 
5921   if (!tryAddingSymbolicOperand(Address, Address + DecVal + 4, true, 4, Inst,
5922                                 Decoder))
5923     Inst.addOperand(MCOperand::createImm(isNeg ? -DecVal : DecVal));
5924   return S;
5925 }
5926 
5927 static DecodeStatus DecodeBFAfterTargetOperand(MCInst &Inst, unsigned Val,
5928                                                uint64_t Address,
5929                                                const void *Decoder) {
5930 
5931   uint64_t LocImm = Inst.getOperand(0).getImm();
5932   Val = LocImm + (2 << Val);
5933   if (!tryAddingSymbolicOperand(Address, Address + Val + 4, true, 4, Inst,
5934                                 Decoder))
5935     Inst.addOperand(MCOperand::createImm(Val));
5936   return MCDisassembler::Success;
5937 }
5938 
5939 static DecodeStatus DecodePredNoALOperand(MCInst &Inst, unsigned Val,
5940                                           uint64_t Address,
5941                                           const void *Decoder) {
5942   if (Val >= ARMCC::AL)  // also exclude the non-condition NV
5943     return MCDisassembler::Fail;
5944   Inst.addOperand(MCOperand::createImm(Val));
5945   return MCDisassembler::Success;
5946 }
5947 
5948 static DecodeStatus DecodeLOLoop(MCInst &Inst, unsigned Insn, uint64_t Address,
5949                                  const void *Decoder) {
5950   DecodeStatus S = MCDisassembler::Success;
5951 
5952   if (Inst.getOpcode() == ARM::MVE_LCTP)
5953     return S;
5954 
5955   unsigned Imm = fieldFromInstruction(Insn, 11, 1) |
5956                  fieldFromInstruction(Insn, 1, 10) << 1;
5957   switch (Inst.getOpcode()) {
5958   case ARM::t2LEUpdate:
5959   case ARM::MVE_LETP:
5960     Inst.addOperand(MCOperand::createReg(ARM::LR));
5961     Inst.addOperand(MCOperand::createReg(ARM::LR));
5962     LLVM_FALLTHROUGH;
5963   case ARM::t2LE:
5964     if (!Check(S, DecodeBFLabelOperand<false, true, true, 11>(
5965                    Inst, Imm, Address, Decoder)))
5966       return MCDisassembler::Fail;
5967     break;
5968   case ARM::t2WLS:
5969   case ARM::MVE_WLSTP_8:
5970   case ARM::MVE_WLSTP_16:
5971   case ARM::MVE_WLSTP_32:
5972   case ARM::MVE_WLSTP_64:
5973     Inst.addOperand(MCOperand::createReg(ARM::LR));
5974     if (!Check(S,
5975                DecoderGPRRegisterClass(Inst, fieldFromInstruction(Insn, 16, 4),
5976                                        Address, Decoder)) ||
5977         !Check(S, DecodeBFLabelOperand<false, false, true, 11>(
5978                    Inst, Imm, Address, Decoder)))
5979       return MCDisassembler::Fail;
5980     break;
5981   case ARM::t2DLS:
5982   case ARM::MVE_DLSTP_8:
5983   case ARM::MVE_DLSTP_16:
5984   case ARM::MVE_DLSTP_32:
5985   case ARM::MVE_DLSTP_64:
5986     unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5987     if (Rn == 0xF) {
5988       // Enforce all the rest of the instruction bits in LCTP, which
5989       // won't have been reliably checked based on LCTP's own tablegen
5990       // record, because we came to this decode by a roundabout route.
5991       uint32_t CanonicalLCTP = 0xF00FE001, SBZMask = 0x00300FFE;
5992       if ((Insn & ~SBZMask) != CanonicalLCTP)
5993         return MCDisassembler::Fail;   // a mandatory bit is wrong: hard fail
5994       if (Insn != CanonicalLCTP)
5995         Check(S, MCDisassembler::SoftFail); // an SBZ bit is wrong: soft fail
5996 
5997       Inst.setOpcode(ARM::MVE_LCTP);
5998     } else {
5999       Inst.addOperand(MCOperand::createReg(ARM::LR));
6000       if (!Check(S, DecoderGPRRegisterClass(Inst,
6001                                             fieldFromInstruction(Insn, 16, 4),
6002                                             Address, Decoder)))
6003         return MCDisassembler::Fail;
6004     }
6005     break;
6006   }
6007   return S;
6008 }
6009 
6010 static DecodeStatus DecodeLongShiftOperand(MCInst &Inst, unsigned Val,
6011                                            uint64_t Address,
6012                                            const void *Decoder) {
6013   DecodeStatus S = MCDisassembler::Success;
6014 
6015   if (Val == 0)
6016     Val = 32;
6017 
6018   Inst.addOperand(MCOperand::createImm(Val));
6019 
6020   return S;
6021 }
6022 
6023 static DecodeStatus DecodetGPROddRegisterClass(MCInst &Inst, unsigned RegNo,
6024                                    uint64_t Address, const void *Decoder) {
6025   if ((RegNo) + 1 > 11)
6026     return MCDisassembler::Fail;
6027 
6028   unsigned Register = GPRDecoderTable[(RegNo) + 1];
6029   Inst.addOperand(MCOperand::createReg(Register));
6030   return MCDisassembler::Success;
6031 }
6032 
6033 static DecodeStatus DecodetGPREvenRegisterClass(MCInst &Inst, unsigned RegNo,
6034                                    uint64_t Address, const void *Decoder) {
6035   if ((RegNo) > 14)
6036     return MCDisassembler::Fail;
6037 
6038   unsigned Register = GPRDecoderTable[(RegNo)];
6039   Inst.addOperand(MCOperand::createReg(Register));
6040   return MCDisassembler::Success;
6041 }
6042 
6043 static DecodeStatus DecodeVSCCLRM(MCInst &Inst, unsigned Insn, uint64_t Address,
6044                                   const void *Decoder) {
6045   DecodeStatus S = MCDisassembler::Success;
6046 
6047   Inst.addOperand(MCOperand::createImm(ARMCC::AL));
6048   Inst.addOperand(MCOperand::createReg(0));
6049   if (Inst.getOpcode() == ARM::VSCCLRMD) {
6050     unsigned reglist = (fieldFromInstruction(Insn, 1, 7) << 1) |
6051                        (fieldFromInstruction(Insn, 12, 4) << 8) |
6052                        (fieldFromInstruction(Insn, 22, 1) << 12);
6053     if (!Check(S, DecodeDPRRegListOperand(Inst, reglist, Address, Decoder))) {
6054       return MCDisassembler::Fail;
6055     }
6056   } else {
6057     unsigned reglist = fieldFromInstruction(Insn, 0, 8) |
6058                        (fieldFromInstruction(Insn, 22, 1) << 8) |
6059                        (fieldFromInstruction(Insn, 12, 4) << 9);
6060     if (!Check(S, DecodeSPRRegListOperand(Inst, reglist, Address, Decoder))) {
6061       return MCDisassembler::Fail;
6062     }
6063   }
6064   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6065 
6066   return S;
6067 }
6068 
6069 static DecodeStatus DecodeMQPRRegisterClass(MCInst &Inst, unsigned RegNo,
6070                               uint64_t Address,
6071                               const void *Decoder) {
6072   if (RegNo > 7)
6073     return MCDisassembler::Fail;
6074 
6075   unsigned Register = QPRDecoderTable[RegNo];
6076   Inst.addOperand(MCOperand::createReg(Register));
6077   return MCDisassembler::Success;
6078 }
6079 
6080 static const uint16_t QQPRDecoderTable[] = {
6081      ARM::Q0_Q1,  ARM::Q1_Q2,  ARM::Q2_Q3,  ARM::Q3_Q4,
6082      ARM::Q4_Q5,  ARM::Q5_Q6,  ARM::Q6_Q7
6083 };
6084 
6085 static DecodeStatus DecodeQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
6086                               uint64_t Address,
6087                               const void *Decoder) {
6088   if (RegNo > 6)
6089     return MCDisassembler::Fail;
6090 
6091   unsigned Register = QQPRDecoderTable[RegNo];
6092   Inst.addOperand(MCOperand::createReg(Register));
6093   return MCDisassembler::Success;
6094 }
6095 
6096 static const uint16_t QQQQPRDecoderTable[] = {
6097      ARM::Q0_Q1_Q2_Q3,  ARM::Q1_Q2_Q3_Q4,  ARM::Q2_Q3_Q4_Q5,
6098      ARM::Q3_Q4_Q5_Q6,  ARM::Q4_Q5_Q6_Q7
6099 };
6100 
6101 static DecodeStatus DecodeQQQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
6102                               uint64_t Address,
6103                               const void *Decoder) {
6104   if (RegNo > 4)
6105     return MCDisassembler::Fail;
6106 
6107   unsigned Register = QQQQPRDecoderTable[RegNo];
6108   Inst.addOperand(MCOperand::createReg(Register));
6109   return MCDisassembler::Success;
6110 }
6111 
6112 static DecodeStatus DecodeVPTMaskOperand(MCInst &Inst, unsigned Val,
6113                                          uint64_t Address,
6114                                          const void *Decoder) {
6115   DecodeStatus S = MCDisassembler::Success;
6116 
6117   // Parse VPT mask and encode it in the MCInst as an immediate with the same
6118   // format as the it_mask.  That is, from the second 'e|t' encode 'e' as 1 and
6119   // 't' as 0 and finish with a 1.
6120   unsigned Imm = 0;
6121   // We always start with a 't'.
6122   unsigned CurBit = 0;
6123   for (int i = 3; i >= 0; --i) {
6124     // If the bit we are looking at is not the same as last one, invert the
6125     // CurBit, if it is the same leave it as is.
6126     CurBit ^= (Val >> i) & 1U;
6127 
6128     // Encode the CurBit at the right place in the immediate.
6129     Imm |= (CurBit << i);
6130 
6131     // If we are done, finish the encoding with a 1.
6132     if ((Val & ~(~0U << i)) == 0) {
6133       Imm |= 1U << i;
6134       break;
6135     }
6136   }
6137 
6138   Inst.addOperand(MCOperand::createImm(Imm));
6139 
6140   return S;
6141 }
6142 
6143 static DecodeStatus DecodeVpredROperand(MCInst &Inst, unsigned RegNo,
6144                                         uint64_t Address, const void *Decoder) {
6145   // The vpred_r operand type includes an MQPR register field derived
6146   // from the encoding. But we don't actually want to add an operand
6147   // to the MCInst at this stage, because AddThumbPredicate will do it
6148   // later, and will infer the register number from the TIED_TO
6149   // constraint. So this is a deliberately empty decoder method that
6150   // will inhibit the auto-generated disassembly code from adding an
6151   // operand at all.
6152   return MCDisassembler::Success;
6153 }
6154 
6155 static DecodeStatus DecodeRestrictedIPredicateOperand(MCInst &Inst,
6156                                                       unsigned Val,
6157                                                       uint64_t Address,
6158                                                       const void *Decoder) {
6159   Inst.addOperand(MCOperand::createImm((Val & 0x1) == 0 ? ARMCC::EQ : ARMCC::NE));
6160   return MCDisassembler::Success;
6161 }
6162 
6163 static DecodeStatus DecodeRestrictedSPredicateOperand(MCInst &Inst,
6164                                                       unsigned Val,
6165                                                       uint64_t Address,
6166                                                       const void *Decoder) {
6167   unsigned Code;
6168   switch (Val & 0x3) {
6169   case 0:
6170     Code = ARMCC::GE;
6171     break;
6172   case 1:
6173     Code = ARMCC::LT;
6174     break;
6175   case 2:
6176     Code = ARMCC::GT;
6177     break;
6178   case 3:
6179     Code = ARMCC::LE;
6180     break;
6181   }
6182   Inst.addOperand(MCOperand::createImm(Code));
6183   return MCDisassembler::Success;
6184 }
6185 
6186 static DecodeStatus DecodeRestrictedUPredicateOperand(MCInst &Inst,
6187                                                       unsigned Val,
6188                                                       uint64_t Address,
6189                                                       const void *Decoder) {
6190   Inst.addOperand(MCOperand::createImm((Val & 0x1) == 0 ? ARMCC::HS : ARMCC::HI));
6191   return MCDisassembler::Success;
6192 }
6193 
6194 static DecodeStatus DecodeRestrictedFPPredicateOperand(MCInst &Inst, unsigned Val,
6195                                                      uint64_t Address,
6196                                                      const void *Decoder) {
6197   unsigned Code;
6198   switch (Val) {
6199   default:
6200     return MCDisassembler::Fail;
6201   case 0:
6202     Code = ARMCC::EQ;
6203     break;
6204   case 1:
6205     Code = ARMCC::NE;
6206     break;
6207   case 4:
6208     Code = ARMCC::GE;
6209     break;
6210   case 5:
6211     Code = ARMCC::LT;
6212     break;
6213   case 6:
6214     Code = ARMCC::GT;
6215     break;
6216   case 7:
6217     Code = ARMCC::LE;
6218     break;
6219   }
6220 
6221   Inst.addOperand(MCOperand::createImm(Code));
6222   return MCDisassembler::Success;
6223 }
6224 
6225 static DecodeStatus DecodeVCVTImmOperand(MCInst &Inst, unsigned Val,
6226                                          uint64_t Address, const void *Decoder) {
6227   DecodeStatus S = MCDisassembler::Success;
6228 
6229   unsigned DecodedVal = 64 - Val;
6230 
6231   switch (Inst.getOpcode()) {
6232   case ARM::MVE_VCVTf16s16_fix:
6233   case ARM::MVE_VCVTs16f16_fix:
6234   case ARM::MVE_VCVTf16u16_fix:
6235   case ARM::MVE_VCVTu16f16_fix:
6236     if (DecodedVal > 16)
6237       return MCDisassembler::Fail;
6238     break;
6239   case ARM::MVE_VCVTf32s32_fix:
6240   case ARM::MVE_VCVTs32f32_fix:
6241   case ARM::MVE_VCVTf32u32_fix:
6242   case ARM::MVE_VCVTu32f32_fix:
6243     if (DecodedVal > 32)
6244       return MCDisassembler::Fail;
6245     break;
6246   }
6247 
6248   Inst.addOperand(MCOperand::createImm(64 - Val));
6249 
6250   return S;
6251 }
6252 
6253 static unsigned FixedRegForVSTRVLDR_SYSREG(unsigned Opcode) {
6254   switch (Opcode) {
6255   case ARM::VSTR_P0_off:
6256   case ARM::VSTR_P0_pre:
6257   case ARM::VSTR_P0_post:
6258   case ARM::VLDR_P0_off:
6259   case ARM::VLDR_P0_pre:
6260   case ARM::VLDR_P0_post:
6261     return ARM::P0;
6262   default:
6263     return 0;
6264   }
6265 }
6266 
6267 template<bool Writeback>
6268 static DecodeStatus DecodeVSTRVLDR_SYSREG(MCInst &Inst, unsigned Val,
6269                                           uint64_t Address,
6270                                           const void *Decoder) {
6271   switch (Inst.getOpcode()) {
6272   case ARM::VSTR_FPSCR_pre:
6273   case ARM::VSTR_FPSCR_NZCVQC_pre:
6274   case ARM::VLDR_FPSCR_pre:
6275   case ARM::VLDR_FPSCR_NZCVQC_pre:
6276   case ARM::VSTR_FPSCR_off:
6277   case ARM::VSTR_FPSCR_NZCVQC_off:
6278   case ARM::VLDR_FPSCR_off:
6279   case ARM::VLDR_FPSCR_NZCVQC_off:
6280   case ARM::VSTR_FPSCR_post:
6281   case ARM::VSTR_FPSCR_NZCVQC_post:
6282   case ARM::VLDR_FPSCR_post:
6283   case ARM::VLDR_FPSCR_NZCVQC_post:
6284     const FeatureBitset &featureBits =
6285         ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
6286 
6287     if (!featureBits[ARM::HasMVEIntegerOps] && !featureBits[ARM::FeatureVFP2])
6288       return MCDisassembler::Fail;
6289   }
6290 
6291   DecodeStatus S = MCDisassembler::Success;
6292   if (unsigned Sysreg = FixedRegForVSTRVLDR_SYSREG(Inst.getOpcode()))
6293     Inst.addOperand(MCOperand::createReg(Sysreg));
6294   unsigned Rn = fieldFromInstruction(Val, 16, 4);
6295   unsigned addr = fieldFromInstruction(Val, 0, 7) |
6296                   (fieldFromInstruction(Val, 23, 1) << 7) | (Rn << 8);
6297 
6298   if (Writeback) {
6299     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
6300       return MCDisassembler::Fail;
6301   }
6302   if (!Check(S, DecodeT2AddrModeImm7s4(Inst, addr, Address, Decoder)))
6303     return MCDisassembler::Fail;
6304 
6305   Inst.addOperand(MCOperand::createImm(ARMCC::AL));
6306   Inst.addOperand(MCOperand::createReg(0));
6307 
6308   return S;
6309 }
6310 
6311 static inline DecodeStatus DecodeMVE_MEM_pre(
6312   MCInst &Inst, unsigned Val, uint64_t Address, const void *Decoder,
6313   unsigned Rn, OperandDecoder RnDecoder, OperandDecoder AddrDecoder) {
6314   DecodeStatus S = MCDisassembler::Success;
6315 
6316   unsigned Qd = fieldFromInstruction(Val, 13, 3);
6317   unsigned addr = fieldFromInstruction(Val, 0, 7) |
6318                   (fieldFromInstruction(Val, 23, 1) << 7) | (Rn << 8);
6319 
6320   if (!Check(S, RnDecoder(Inst, Rn, Address, Decoder)))
6321     return MCDisassembler::Fail;
6322   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6323     return MCDisassembler::Fail;
6324   if (!Check(S, AddrDecoder(Inst, addr, Address, Decoder)))
6325     return MCDisassembler::Fail;
6326 
6327   return S;
6328 }
6329 
6330 template <int shift>
6331 static DecodeStatus DecodeMVE_MEM_1_pre(MCInst &Inst, unsigned Val,
6332                                         uint64_t Address, const void *Decoder) {
6333   return DecodeMVE_MEM_pre(Inst, Val, Address, Decoder,
6334                            fieldFromInstruction(Val, 16, 3),
6335                            DecodetGPRRegisterClass,
6336                            DecodeTAddrModeImm7<shift>);
6337 }
6338 
6339 template <int shift>
6340 static DecodeStatus DecodeMVE_MEM_2_pre(MCInst &Inst, unsigned Val,
6341                                         uint64_t Address, const void *Decoder) {
6342   return DecodeMVE_MEM_pre(Inst, Val, Address, Decoder,
6343                            fieldFromInstruction(Val, 16, 4),
6344                            DecoderGPRRegisterClass,
6345                            DecodeT2AddrModeImm7<shift,1>);
6346 }
6347 
6348 template <int shift>
6349 static DecodeStatus DecodeMVE_MEM_3_pre(MCInst &Inst, unsigned Val,
6350                                         uint64_t Address, const void *Decoder) {
6351   return DecodeMVE_MEM_pre(Inst, Val, Address, Decoder,
6352                            fieldFromInstruction(Val, 17, 3),
6353                            DecodeMQPRRegisterClass,
6354                            DecodeMveAddrModeQ<shift>);
6355 }
6356 
6357 template<unsigned MinLog, unsigned MaxLog>
6358 static DecodeStatus DecodePowerTwoOperand(MCInst &Inst, unsigned Val,
6359                                           uint64_t Address,
6360                                           const void *Decoder) {
6361   DecodeStatus S = MCDisassembler::Success;
6362 
6363   if (Val < MinLog || Val > MaxLog)
6364     return MCDisassembler::Fail;
6365 
6366   Inst.addOperand(MCOperand::createImm(1LL << Val));
6367   return S;
6368 }
6369 
6370 template <int shift>
6371 static DecodeStatus DecodeExpandedImmOperand(MCInst &Inst, unsigned Val,
6372                                              uint64_t Address,
6373                                              const void *Decoder) {
6374     Val <<= shift;
6375 
6376     Inst.addOperand(MCOperand::createImm(Val));
6377     return MCDisassembler::Success;
6378 }
6379 
6380 template<unsigned start>
6381 static DecodeStatus DecodeMVEPairVectorIndexOperand(MCInst &Inst, unsigned Val,
6382                                                     uint64_t Address,
6383                                                     const void *Decoder) {
6384   DecodeStatus S = MCDisassembler::Success;
6385 
6386   Inst.addOperand(MCOperand::createImm(start + Val));
6387 
6388   return S;
6389 }
6390 
6391 static DecodeStatus DecodeMVEVMOVQtoDReg(MCInst &Inst, unsigned Insn,
6392                                          uint64_t Address, const void *Decoder) {
6393   DecodeStatus S = MCDisassembler::Success;
6394   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
6395   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
6396   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
6397                  fieldFromInstruction(Insn, 13, 3));
6398   unsigned index = fieldFromInstruction(Insn, 4, 1);
6399 
6400   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
6401     return MCDisassembler::Fail;
6402   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2, Address, Decoder)))
6403     return MCDisassembler::Fail;
6404   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6405     return MCDisassembler::Fail;
6406   if (!Check(S, DecodeMVEPairVectorIndexOperand<2>(Inst, index, Address, Decoder)))
6407     return MCDisassembler::Fail;
6408   if (!Check(S, DecodeMVEPairVectorIndexOperand<0>(Inst, index, Address, Decoder)))
6409     return MCDisassembler::Fail;
6410 
6411   return S;
6412 }
6413 
6414 static DecodeStatus DecodeMVEVMOVDRegtoQ(MCInst &Inst, unsigned Insn,
6415                                          uint64_t Address, const void *Decoder) {
6416   DecodeStatus S = MCDisassembler::Success;
6417   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
6418   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
6419   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
6420                  fieldFromInstruction(Insn, 13, 3));
6421   unsigned index = fieldFromInstruction(Insn, 4, 1);
6422 
6423   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6424     return MCDisassembler::Fail;
6425   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6426     return MCDisassembler::Fail;
6427   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
6428     return MCDisassembler::Fail;
6429   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2, Address, Decoder)))
6430     return MCDisassembler::Fail;
6431   if (!Check(S, DecodeMVEPairVectorIndexOperand<2>(Inst, index, Address, Decoder)))
6432     return MCDisassembler::Fail;
6433   if (!Check(S, DecodeMVEPairVectorIndexOperand<0>(Inst, index, Address, Decoder)))
6434     return MCDisassembler::Fail;
6435 
6436   return S;
6437 }
6438 
6439 static DecodeStatus DecodeMVEOverlappingLongShift(
6440   MCInst &Inst, unsigned Insn, uint64_t Address, const void *Decoder) {
6441   DecodeStatus S = MCDisassembler::Success;
6442 
6443   unsigned RdaLo = fieldFromInstruction(Insn, 17, 3) << 1;
6444   unsigned RdaHi = fieldFromInstruction(Insn, 9, 3) << 1;
6445   unsigned Rm = fieldFromInstruction(Insn, 12, 4);
6446 
6447   if (RdaHi == 14) {
6448     // This value of RdaHi (really indicating pc, because RdaHi has to
6449     // be an odd-numbered register, so the low bit will be set by the
6450     // decode function below) indicates that we must decode as SQRSHR
6451     // or UQRSHL, which both have a single Rda register field with all
6452     // four bits.
6453     unsigned Rda = fieldFromInstruction(Insn, 16, 4);
6454 
6455     switch (Inst.getOpcode()) {
6456       case ARM::MVE_ASRLr:
6457       case ARM::MVE_SQRSHRL:
6458         Inst.setOpcode(ARM::MVE_SQRSHR);
6459         break;
6460       case ARM::MVE_LSLLr:
6461       case ARM::MVE_UQRSHLL:
6462         Inst.setOpcode(ARM::MVE_UQRSHL);
6463         break;
6464       default:
6465         llvm_unreachable("Unexpected starting opcode!");
6466     }
6467 
6468     // Rda as output parameter
6469     if (!Check(S, DecoderGPRRegisterClass(Inst, Rda, Address, Decoder)))
6470       return MCDisassembler::Fail;
6471 
6472     // Rda again as input parameter
6473     if (!Check(S, DecoderGPRRegisterClass(Inst, Rda, Address, Decoder)))
6474       return MCDisassembler::Fail;
6475 
6476     // Rm, the amount to shift by
6477     if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
6478       return MCDisassembler::Fail;
6479 
6480     if (fieldFromInstruction (Insn, 6, 3) != 4)
6481       return MCDisassembler::SoftFail;
6482 
6483     if (Rda == Rm)
6484       return MCDisassembler::SoftFail;
6485 
6486     return S;
6487   }
6488 
6489   // Otherwise, we decode as whichever opcode our caller has already
6490   // put into Inst. Those all look the same:
6491 
6492   // RdaLo,RdaHi as output parameters
6493   if (!Check(S, DecodetGPREvenRegisterClass(Inst, RdaLo, Address, Decoder)))
6494     return MCDisassembler::Fail;
6495   if (!Check(S, DecodetGPROddRegisterClass(Inst, RdaHi, Address, Decoder)))
6496     return MCDisassembler::Fail;
6497 
6498   // RdaLo,RdaHi again as input parameters
6499   if (!Check(S, DecodetGPREvenRegisterClass(Inst, RdaLo, Address, Decoder)))
6500     return MCDisassembler::Fail;
6501   if (!Check(S, DecodetGPROddRegisterClass(Inst, RdaHi, Address, Decoder)))
6502     return MCDisassembler::Fail;
6503 
6504   // Rm, the amount to shift by
6505   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
6506     return MCDisassembler::Fail;
6507 
6508   if (Inst.getOpcode() == ARM::MVE_SQRSHRL ||
6509       Inst.getOpcode() == ARM::MVE_UQRSHLL) {
6510     unsigned Saturate = fieldFromInstruction(Insn, 7, 1);
6511     // Saturate, the bit position for saturation
6512     Inst.addOperand(MCOperand::createImm(Saturate));
6513   }
6514 
6515   return S;
6516 }
6517 
6518 static DecodeStatus DecodeMVEVCVTt1fp(MCInst &Inst, unsigned Insn, uint64_t Address,
6519                                       const void *Decoder) {
6520   DecodeStatus S = MCDisassembler::Success;
6521   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
6522                  fieldFromInstruction(Insn, 13, 3));
6523   unsigned Qm = ((fieldFromInstruction(Insn, 5, 1) << 3) |
6524                  fieldFromInstruction(Insn, 1, 3));
6525   unsigned imm6 = fieldFromInstruction(Insn, 16, 6);
6526 
6527   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6528     return MCDisassembler::Fail;
6529   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
6530     return MCDisassembler::Fail;
6531   if (!Check(S, DecodeVCVTImmOperand(Inst, imm6, Address, Decoder)))
6532     return MCDisassembler::Fail;
6533 
6534   return S;
6535 }
6536 
6537 template<bool scalar, OperandDecoder predicate_decoder>
6538 static DecodeStatus DecodeMVEVCMP(MCInst &Inst, unsigned Insn, uint64_t Address,
6539                                   const void *Decoder) {
6540   DecodeStatus S = MCDisassembler::Success;
6541   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6542   unsigned Qn = fieldFromInstruction(Insn, 17, 3);
6543   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qn, Address, Decoder)))
6544     return MCDisassembler::Fail;
6545 
6546   unsigned fc;
6547 
6548   if (scalar) {
6549     fc = fieldFromInstruction(Insn, 12, 1) << 2 |
6550          fieldFromInstruction(Insn, 7, 1) |
6551          fieldFromInstruction(Insn, 5, 1) << 1;
6552     unsigned Rm = fieldFromInstruction(Insn, 0, 4);
6553     if (!Check(S, DecodeGPRwithZRRegisterClass(Inst, Rm, Address, Decoder)))
6554       return MCDisassembler::Fail;
6555   } else {
6556     fc = fieldFromInstruction(Insn, 12, 1) << 2 |
6557          fieldFromInstruction(Insn, 7, 1) |
6558          fieldFromInstruction(Insn, 0, 1) << 1;
6559     unsigned Qm = fieldFromInstruction(Insn, 5, 1) << 4 |
6560                   fieldFromInstruction(Insn, 1, 3);
6561     if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
6562       return MCDisassembler::Fail;
6563   }
6564 
6565   if (!Check(S, predicate_decoder(Inst, fc, Address, Decoder)))
6566     return MCDisassembler::Fail;
6567 
6568   Inst.addOperand(MCOperand::createImm(ARMVCC::None));
6569   Inst.addOperand(MCOperand::createReg(0));
6570   Inst.addOperand(MCOperand::createImm(0));
6571 
6572   return S;
6573 }
6574 
6575 static DecodeStatus DecodeMveVCTP(MCInst &Inst, unsigned Insn, uint64_t Address,
6576                                   const void *Decoder) {
6577   DecodeStatus S = MCDisassembler::Success;
6578   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6579   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
6580   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
6581     return MCDisassembler::Fail;
6582   return S;
6583 }
6584 
6585 static DecodeStatus DecodeMVEVPNOT(MCInst &Inst, unsigned Insn, uint64_t Address,
6586                                    const void *Decoder) {
6587   DecodeStatus S = MCDisassembler::Success;
6588   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6589   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6590   return S;
6591 }
6592