1 //===- ARMDisassembler.cpp - Disassembler for ARM/Thumb ISA ---------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "ARMBaseInstrInfo.h"
10 #include "MCTargetDesc/ARMAddressingModes.h"
11 #include "MCTargetDesc/ARMBaseInfo.h"
12 #include "MCTargetDesc/ARMMCTargetDesc.h"
13 #include "TargetInfo/ARMTargetInfo.h"
14 #include "Utils/ARMBaseInfo.h"
15 #include "llvm/MC/MCContext.h"
16 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
17 #include "llvm/MC/MCFixedLenDisassembler.h"
18 #include "llvm/MC/MCInst.h"
19 #include "llvm/MC/MCInstrDesc.h"
20 #include "llvm/MC/MCSubtargetInfo.h"
21 #include "llvm/MC/SubtargetFeature.h"
22 #include "llvm/Support/Compiler.h"
23 #include "llvm/Support/ErrorHandling.h"
24 #include "llvm/Support/MathExtras.h"
25 #include "llvm/Support/TargetRegistry.h"
26 #include "llvm/Support/raw_ostream.h"
27 #include <algorithm>
28 #include <cassert>
29 #include <cstdint>
30 #include <vector>
31 
32 using namespace llvm;
33 
34 #define DEBUG_TYPE "arm-disassembler"
35 
36 using DecodeStatus = MCDisassembler::DecodeStatus;
37 
38 namespace {
39 
40   // Handles the condition code status of instructions in IT blocks
41   class ITStatus
42   {
43     public:
44       // Returns the condition code for instruction in IT block
45       unsigned getITCC() {
46         unsigned CC = ARMCC::AL;
47         if (instrInITBlock())
48           CC = ITStates.back();
49         return CC;
50       }
51 
52       // Advances the IT block state to the next T or E
53       void advanceITState() {
54         ITStates.pop_back();
55       }
56 
57       // Returns true if the current instruction is in an IT block
58       bool instrInITBlock() {
59         return !ITStates.empty();
60       }
61 
62       // Returns true if current instruction is the last instruction in an IT block
63       bool instrLastInITBlock() {
64         return ITStates.size() == 1;
65       }
66 
67       // Called when decoding an IT instruction. Sets the IT state for
68       // the following instructions that for the IT block. Firstcond
69       // corresponds to the field in the IT instruction encoding; Mask
70       // is in the MCOperand format in which 1 means 'else' and 0 'then'.
71       void setITState(char Firstcond, char Mask) {
72         // (3 - the number of trailing zeros) is the number of then / else.
73         unsigned NumTZ = countTrailingZeros<uint8_t>(Mask);
74         unsigned char CCBits = static_cast<unsigned char>(Firstcond & 0xf);
75         assert(NumTZ <= 3 && "Invalid IT mask!");
76         // push condition codes onto the stack the correct order for the pops
77         for (unsigned Pos = NumTZ+1; Pos <= 3; ++Pos) {
78           unsigned Else = (Mask >> Pos) & 1;
79           ITStates.push_back(CCBits ^ Else);
80         }
81         ITStates.push_back(CCBits);
82       }
83 
84     private:
85       std::vector<unsigned char> ITStates;
86   };
87 
88   class VPTStatus
89   {
90     public:
91       unsigned getVPTPred() {
92         unsigned Pred = ARMVCC::None;
93         if (instrInVPTBlock())
94           Pred = VPTStates.back();
95         return Pred;
96       }
97 
98       void advanceVPTState() {
99         VPTStates.pop_back();
100       }
101 
102       bool instrInVPTBlock() {
103         return !VPTStates.empty();
104       }
105 
106       bool instrLastInVPTBlock() {
107         return VPTStates.size() == 1;
108       }
109 
110       void setVPTState(char Mask) {
111         // (3 - the number of trailing zeros) is the number of then / else.
112         unsigned NumTZ = countTrailingZeros<uint8_t>(Mask);
113         assert(NumTZ <= 3 && "Invalid VPT mask!");
114         // push predicates onto the stack the correct order for the pops
115         for (unsigned Pos = NumTZ+1; Pos <= 3; ++Pos) {
116           bool T = ((Mask >> Pos) & 1) == 0;
117           if (T)
118             VPTStates.push_back(ARMVCC::Then);
119           else
120             VPTStates.push_back(ARMVCC::Else);
121         }
122         VPTStates.push_back(ARMVCC::Then);
123       }
124 
125     private:
126       SmallVector<unsigned char, 4> VPTStates;
127   };
128 
129 /// ARM disassembler for all ARM platforms.
130 class ARMDisassembler : public MCDisassembler {
131 public:
132   ARMDisassembler(const MCSubtargetInfo &STI, MCContext &Ctx) :
133     MCDisassembler(STI, Ctx) {
134   }
135 
136   ~ARMDisassembler() override = default;
137 
138   DecodeStatus getInstruction(MCInst &Instr, uint64_t &Size,
139                               ArrayRef<uint8_t> Bytes, uint64_t Address,
140                               raw_ostream &VStream,
141                               raw_ostream &CStream) const override;
142 
143 private:
144   DecodeStatus getARMInstruction(MCInst &Instr, uint64_t &Size,
145                                  ArrayRef<uint8_t> Bytes, uint64_t Address,
146                                  raw_ostream &VStream,
147                                  raw_ostream &CStream) const;
148 
149   DecodeStatus getThumbInstruction(MCInst &Instr, uint64_t &Size,
150                                    ArrayRef<uint8_t> Bytes, uint64_t Address,
151                                    raw_ostream &VStream,
152                                    raw_ostream &CStream) const;
153 
154   mutable ITStatus ITBlock;
155   mutable VPTStatus VPTBlock;
156 
157   DecodeStatus AddThumbPredicate(MCInst&) const;
158   void UpdateThumbVFPPredicate(DecodeStatus &, MCInst&) const;
159 };
160 
161 } // end anonymous namespace
162 
163 static bool Check(DecodeStatus &Out, DecodeStatus In) {
164   switch (In) {
165     case MCDisassembler::Success:
166       // Out stays the same.
167       return true;
168     case MCDisassembler::SoftFail:
169       Out = In;
170       return true;
171     case MCDisassembler::Fail:
172       Out = In;
173       return false;
174   }
175   llvm_unreachable("Invalid DecodeStatus!");
176 }
177 
178 // Forward declare these because the autogenerated code will reference them.
179 // Definitions are further down.
180 static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, unsigned RegNo,
181                                    uint64_t Address, const void *Decoder);
182 static DecodeStatus DecodeCLRMGPRRegisterClass(MCInst &Inst, unsigned RegNo,
183                                    uint64_t Address, const void *Decoder);
184 static DecodeStatus DecodetGPROddRegisterClass(MCInst &Inst, unsigned RegNo,
185                                    uint64_t Address, const void *Decoder);
186 static DecodeStatus DecodetGPREvenRegisterClass(MCInst &Inst, unsigned RegNo,
187                                    uint64_t Address, const void *Decoder);
188 static DecodeStatus DecodeGPRnopcRegisterClass(MCInst &Inst,
189                                                unsigned RegNo, uint64_t Address,
190                                                const void *Decoder);
191 static DecodeStatus DecodeGPRwithAPSRRegisterClass(MCInst &Inst,
192                                                unsigned RegNo, uint64_t Address,
193                                                const void *Decoder);
194 static DecodeStatus DecodeGPRwithZRRegisterClass(MCInst &Inst,
195                                                unsigned RegNo, uint64_t Address,
196                                                const void *Decoder);
197 static DecodeStatus DecodeGPRwithZRnospRegisterClass(
198     MCInst &Inst, unsigned RegNo, uint64_t Address, const void *Decoder);
199 static DecodeStatus DecodetGPRRegisterClass(MCInst &Inst, unsigned RegNo,
200                                    uint64_t Address, const void *Decoder);
201 static DecodeStatus DecodetcGPRRegisterClass(MCInst &Inst, unsigned RegNo,
202                                    uint64_t Address, const void *Decoder);
203 static DecodeStatus DecoderGPRRegisterClass(MCInst &Inst, unsigned RegNo,
204                                    uint64_t Address, const void *Decoder);
205 static DecodeStatus DecodeGPRPairRegisterClass(MCInst &Inst, unsigned RegNo,
206                                    uint64_t Address, const void *Decoder);
207 static DecodeStatus DecodeGPRspRegisterClass(MCInst &Inst, unsigned RegNo,
208                                              uint64_t Address,
209                                              const void *Decoder);
210 static DecodeStatus DecodeHPRRegisterClass(MCInst &Inst, unsigned RegNo,
211                                    uint64_t Address, const void *Decoder);
212 static DecodeStatus DecodeSPRRegisterClass(MCInst &Inst, unsigned RegNo,
213                                    uint64_t Address, const void *Decoder);
214 static DecodeStatus DecodeDPRRegisterClass(MCInst &Inst, unsigned RegNo,
215                                    uint64_t Address, const void *Decoder);
216 static DecodeStatus DecodeDPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
217                                    uint64_t Address, const void *Decoder);
218 static DecodeStatus DecodeSPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
219                                    uint64_t Address, const void *Decoder);
220 static DecodeStatus DecodeDPR_VFP2RegisterClass(MCInst &Inst,
221                                                 unsigned RegNo,
222                                                 uint64_t Address,
223                                                 const void *Decoder);
224 static DecodeStatus DecodeQPRRegisterClass(MCInst &Inst, unsigned RegNo,
225                                    uint64_t Address, const void *Decoder);
226 static DecodeStatus DecodeMQPRRegisterClass(MCInst &Inst, unsigned RegNo,
227                                    uint64_t Address, const void *Decoder);
228 static DecodeStatus DecodeQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
229                                    uint64_t Address, const void *Decoder);
230 static DecodeStatus DecodeQQQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
231                                    uint64_t Address, const void *Decoder);
232 static DecodeStatus DecodeDPairRegisterClass(MCInst &Inst, unsigned RegNo,
233                                    uint64_t Address, const void *Decoder);
234 static DecodeStatus DecodeDPairSpacedRegisterClass(MCInst &Inst,
235                                unsigned RegNo, uint64_t Address,
236                                const void *Decoder);
237 
238 static DecodeStatus DecodePredicateOperand(MCInst &Inst, unsigned Val,
239                                uint64_t Address, const void *Decoder);
240 static DecodeStatus DecodeCCOutOperand(MCInst &Inst, unsigned Val,
241                                uint64_t Address, const void *Decoder);
242 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Val,
243                                uint64_t Address, const void *Decoder);
244 static DecodeStatus DecodeSPRRegListOperand(MCInst &Inst, unsigned Val,
245                                uint64_t Address, const void *Decoder);
246 static DecodeStatus DecodeDPRRegListOperand(MCInst &Inst, unsigned Val,
247                                uint64_t Address, const void *Decoder);
248 
249 static DecodeStatus DecodeBitfieldMaskOperand(MCInst &Inst, unsigned Insn,
250                                uint64_t Address, const void *Decoder);
251 static DecodeStatus DecodeCopMemInstruction(MCInst &Inst, unsigned Insn,
252                                uint64_t Address, const void *Decoder);
253 static DecodeStatus DecodeAddrMode2IdxInstruction(MCInst &Inst,
254                                                   unsigned Insn,
255                                                   uint64_t Address,
256                                                   const void *Decoder);
257 static DecodeStatus DecodeSORegMemOperand(MCInst &Inst, unsigned Insn,
258                                uint64_t Address, const void *Decoder);
259 static DecodeStatus DecodeAddrMode3Instruction(MCInst &Inst,unsigned Insn,
260                                uint64_t Address, const void *Decoder);
261 static DecodeStatus DecodeSORegImmOperand(MCInst &Inst, unsigned Insn,
262                                uint64_t Address, const void *Decoder);
263 static DecodeStatus DecodeSORegRegOperand(MCInst &Inst, unsigned Insn,
264                                uint64_t Address, const void *Decoder);
265 
266 static DecodeStatus DecodeMemMultipleWritebackInstruction(MCInst & Inst,
267                                                   unsigned Insn,
268                                                   uint64_t Adddress,
269                                                   const void *Decoder);
270 static DecodeStatus DecodeT2MOVTWInstruction(MCInst &Inst, unsigned Insn,
271                                uint64_t Address, const void *Decoder);
272 static DecodeStatus DecodeArmMOVTWInstruction(MCInst &Inst, unsigned Insn,
273                                uint64_t Address, const void *Decoder);
274 static DecodeStatus DecodeSMLAInstruction(MCInst &Inst, unsigned Insn,
275                                uint64_t Address, const void *Decoder);
276 static DecodeStatus DecodeHINTInstruction(MCInst &Inst, unsigned Insn,
277                                uint64_t Address, const void *Decoder);
278 static DecodeStatus DecodeCPSInstruction(MCInst &Inst, unsigned Insn,
279                                uint64_t Address, const void *Decoder);
280 static DecodeStatus DecodeTSTInstruction(MCInst &Inst, unsigned Insn,
281                                uint64_t Address, const void *Decoder);
282 static DecodeStatus DecodeSETPANInstruction(MCInst &Inst, unsigned Insn,
283                                uint64_t Address, const void *Decoder);
284 static DecodeStatus DecodeT2CPSInstruction(MCInst &Inst, unsigned Insn,
285                                uint64_t Address, const void *Decoder);
286 static DecodeStatus DecodeAddrModeImm12Operand(MCInst &Inst, unsigned Val,
287                                uint64_t Address, const void *Decoder);
288 static DecodeStatus DecodeAddrMode5Operand(MCInst &Inst, unsigned Val,
289                                uint64_t Address, const void *Decoder);
290 static DecodeStatus DecodeAddrMode5FP16Operand(MCInst &Inst, unsigned Val,
291                                uint64_t Address, const void *Decoder);
292 static DecodeStatus DecodeAddrMode7Operand(MCInst &Inst, unsigned Val,
293                                uint64_t Address, const void *Decoder);
294 static DecodeStatus DecodeT2BInstruction(MCInst &Inst, unsigned Insn,
295                                uint64_t Address, const void *Decoder);
296 static DecodeStatus DecodeBranchImmInstruction(MCInst &Inst,unsigned Insn,
297                                uint64_t Address, const void *Decoder);
298 static DecodeStatus DecodeAddrMode6Operand(MCInst &Inst, unsigned Val,
299                                uint64_t Address, const void *Decoder);
300 static DecodeStatus DecodeVLDST1Instruction(MCInst &Inst, unsigned Val,
301                                uint64_t Address, const void *Decoder);
302 static DecodeStatus DecodeVLDST2Instruction(MCInst &Inst, unsigned Val,
303                                uint64_t Address, const void *Decoder);
304 static DecodeStatus DecodeVLDST3Instruction(MCInst &Inst, unsigned Val,
305                                uint64_t Address, const void *Decoder);
306 static DecodeStatus DecodeVLDST4Instruction(MCInst &Inst, unsigned Val,
307                                uint64_t Address, const void *Decoder);
308 static DecodeStatus DecodeVLDInstruction(MCInst &Inst, unsigned Val,
309                                uint64_t Address, const void *Decoder);
310 static DecodeStatus DecodeVSTInstruction(MCInst &Inst, unsigned Val,
311                                uint64_t Address, const void *Decoder);
312 static DecodeStatus DecodeVLD1DupInstruction(MCInst &Inst, unsigned Val,
313                                uint64_t Address, const void *Decoder);
314 static DecodeStatus DecodeVLD2DupInstruction(MCInst &Inst, unsigned Val,
315                                uint64_t Address, const void *Decoder);
316 static DecodeStatus DecodeVLD3DupInstruction(MCInst &Inst, unsigned Val,
317                                uint64_t Address, const void *Decoder);
318 static DecodeStatus DecodeVLD4DupInstruction(MCInst &Inst, unsigned Val,
319                                uint64_t Address, const void *Decoder);
320 static DecodeStatus DecodeVMOVModImmInstruction(MCInst &Inst,unsigned Val,
321                                uint64_t Address, const void *Decoder);
322 static DecodeStatus DecodeMVEModImmInstruction(MCInst &Inst,unsigned Val,
323                                uint64_t Address, const void *Decoder);
324 static DecodeStatus DecodeMVEVADCInstruction(MCInst &Inst, unsigned Insn,
325                                uint64_t Address, const void *Decoder);
326 static DecodeStatus DecodeVSHLMaxInstruction(MCInst &Inst, unsigned Val,
327                                uint64_t Address, const void *Decoder);
328 static DecodeStatus DecodeShiftRight8Imm(MCInst &Inst, unsigned Val,
329                                uint64_t Address, const void *Decoder);
330 static DecodeStatus DecodeShiftRight16Imm(MCInst &Inst, unsigned Val,
331                                uint64_t Address, const void *Decoder);
332 static DecodeStatus DecodeShiftRight32Imm(MCInst &Inst, unsigned Val,
333                                uint64_t Address, const void *Decoder);
334 static DecodeStatus DecodeShiftRight64Imm(MCInst &Inst, unsigned Val,
335                                uint64_t Address, const void *Decoder);
336 static DecodeStatus DecodeTBLInstruction(MCInst &Inst, unsigned Insn,
337                                uint64_t Address, const void *Decoder);
338 static DecodeStatus DecodePostIdxReg(MCInst &Inst, unsigned Insn,
339                                uint64_t Address, const void *Decoder);
340 static DecodeStatus DecodeMveAddrModeRQ(MCInst &Inst, unsigned Insn,
341                                uint64_t Address, const void *Decoder);
342 template<int shift>
343 static DecodeStatus DecodeMveAddrModeQ(MCInst &Inst, unsigned Insn,
344                                uint64_t Address, const void *Decoder);
345 static DecodeStatus DecodeCoprocessor(MCInst &Inst, unsigned Insn,
346                                uint64_t Address, const void *Decoder);
347 static DecodeStatus DecodeMemBarrierOption(MCInst &Inst, unsigned Insn,
348                                uint64_t Address, const void *Decoder);
349 static DecodeStatus DecodeInstSyncBarrierOption(MCInst &Inst, unsigned Insn,
350                                uint64_t Address, const void *Decoder);
351 static DecodeStatus DecodeMSRMask(MCInst &Inst, unsigned Insn,
352                                uint64_t Address, const void *Decoder);
353 static DecodeStatus DecodeBankedReg(MCInst &Inst, unsigned Insn,
354                                uint64_t Address, const void *Decoder);
355 static DecodeStatus DecodeDoubleRegLoad(MCInst &Inst, unsigned Insn,
356                                uint64_t Address, const void *Decoder);
357 static DecodeStatus DecodeDoubleRegStore(MCInst &Inst, unsigned Insn,
358                                uint64_t Address, const void *Decoder);
359 static DecodeStatus DecodeLDRPreImm(MCInst &Inst, unsigned Insn,
360                                uint64_t Address, const void *Decoder);
361 static DecodeStatus DecodeLDRPreReg(MCInst &Inst, unsigned Insn,
362                                uint64_t Address, const void *Decoder);
363 static DecodeStatus DecodeSTRPreImm(MCInst &Inst, unsigned Insn,
364                                uint64_t Address, const void *Decoder);
365 static DecodeStatus DecodeSTRPreReg(MCInst &Inst, unsigned Insn,
366                                uint64_t Address, const void *Decoder);
367 static DecodeStatus DecodeVLD1LN(MCInst &Inst, unsigned Insn,
368                                uint64_t Address, const void *Decoder);
369 static DecodeStatus DecodeVLD2LN(MCInst &Inst, unsigned Insn,
370                                uint64_t Address, const void *Decoder);
371 static DecodeStatus DecodeVLD3LN(MCInst &Inst, unsigned Insn,
372                                uint64_t Address, const void *Decoder);
373 static DecodeStatus DecodeVLD4LN(MCInst &Inst, unsigned Insn,
374                                uint64_t Address, const void *Decoder);
375 static DecodeStatus DecodeVST1LN(MCInst &Inst, unsigned Insn,
376                                uint64_t Address, const void *Decoder);
377 static DecodeStatus DecodeVST2LN(MCInst &Inst, unsigned Insn,
378                                uint64_t Address, const void *Decoder);
379 static DecodeStatus DecodeVST3LN(MCInst &Inst, unsigned Insn,
380                                uint64_t Address, const void *Decoder);
381 static DecodeStatus DecodeVST4LN(MCInst &Inst, unsigned Insn,
382                                uint64_t Address, const void *Decoder);
383 static DecodeStatus DecodeVMOVSRR(MCInst &Inst, unsigned Insn,
384                                uint64_t Address, const void *Decoder);
385 static DecodeStatus DecodeVMOVRRS(MCInst &Inst, unsigned Insn,
386                                uint64_t Address, const void *Decoder);
387 static DecodeStatus DecodeSwap(MCInst &Inst, unsigned Insn,
388                                uint64_t Address, const void *Decoder);
389 static DecodeStatus DecodeVCVTD(MCInst &Inst, unsigned Insn,
390                                 uint64_t Address, const void *Decoder);
391 static DecodeStatus DecodeVCVTQ(MCInst &Inst, unsigned Insn,
392                                 uint64_t Address, const void *Decoder);
393 static DecodeStatus DecodeVCVTImmOperand(MCInst &Inst, unsigned Insn,
394                                          uint64_t Address, const void *Decoder);
395 static DecodeStatus DecodeNEONComplexLane64Instruction(MCInst &Inst,
396                                                        unsigned Val,
397                                                        uint64_t Address,
398                                                        const void *Decoder);
399 
400 static DecodeStatus DecodeThumbAddSpecialReg(MCInst &Inst, uint16_t Insn,
401                                uint64_t Address, const void *Decoder);
402 static DecodeStatus DecodeThumbBROperand(MCInst &Inst, unsigned Val,
403                                uint64_t Address, const void *Decoder);
404 static DecodeStatus DecodeT2BROperand(MCInst &Inst, unsigned Val,
405                                uint64_t Address, const void *Decoder);
406 static DecodeStatus DecodeThumbCmpBROperand(MCInst &Inst, unsigned Val,
407                                uint64_t Address, const void *Decoder);
408 static DecodeStatus DecodeThumbAddrModeRR(MCInst &Inst, unsigned Val,
409                                uint64_t Address, const void *Decoder);
410 static DecodeStatus DecodeThumbAddrModeIS(MCInst &Inst, unsigned Val,
411                                uint64_t Address, const void *Decoder);
412 static DecodeStatus DecodeThumbAddrModePC(MCInst &Inst, unsigned Val,
413                                uint64_t Address, const void *Decoder);
414 static DecodeStatus DecodeThumbAddrModeSP(MCInst &Inst, unsigned Val,
415                                uint64_t Address, const void *Decoder);
416 static DecodeStatus DecodeT2AddrModeSOReg(MCInst &Inst, unsigned Val,
417                                uint64_t Address, const void *Decoder);
418 static DecodeStatus DecodeT2LoadShift(MCInst &Inst, unsigned Val,
419                                uint64_t Address, const void *Decoder);
420 static DecodeStatus DecodeT2LoadImm8(MCInst &Inst, unsigned Insn,
421                                uint64_t Address, const void* Decoder);
422 static DecodeStatus DecodeT2LoadImm12(MCInst &Inst, unsigned Insn,
423                                uint64_t Address, const void* Decoder);
424 static DecodeStatus DecodeT2LoadT(MCInst &Inst, unsigned Insn,
425                                uint64_t Address, const void* Decoder);
426 static DecodeStatus DecodeT2LoadLabel(MCInst &Inst, unsigned Insn,
427                                uint64_t Address, const void* Decoder);
428 static DecodeStatus DecodeT2Imm8S4(MCInst &Inst, unsigned Val,
429                                uint64_t Address, const void *Decoder);
430 static DecodeStatus DecodeT2Imm7S4(MCInst &Inst, unsigned Val,
431                                uint64_t Address, const void *Decoder);
432 static DecodeStatus DecodeT2AddrModeImm8s4(MCInst &Inst, unsigned Val,
433                                uint64_t Address, const void *Decoder);
434 static DecodeStatus DecodeT2AddrModeImm7s4(MCInst &Inst, unsigned Val,
435                                            uint64_t Address,
436                                            const void *Decoder);
437 static DecodeStatus DecodeT2AddrModeImm0_1020s4(MCInst &Inst,unsigned Val,
438                                uint64_t Address, const void *Decoder);
439 static DecodeStatus DecodeT2Imm8(MCInst &Inst, unsigned Val,
440                                uint64_t Address, const void *Decoder);
441 template<int shift>
442 static DecodeStatus DecodeT2Imm7(MCInst &Inst, unsigned Val,
443                                uint64_t Address, const void *Decoder);
444 static DecodeStatus DecodeT2AddrModeImm8(MCInst &Inst, unsigned Val,
445                                uint64_t Address, const void *Decoder);
446 template<int shift>
447 static DecodeStatus DecodeTAddrModeImm7(MCInst &Inst, unsigned Val,
448                                uint64_t Address, const void *Decoder);
449 template<int shift, int WriteBack>
450 static DecodeStatus DecodeT2AddrModeImm7(MCInst &Inst, unsigned Val,
451                                uint64_t Address, const void *Decoder);
452 static DecodeStatus DecodeThumbAddSPImm(MCInst &Inst, uint16_t Val,
453                                uint64_t Address, const void *Decoder);
454 static DecodeStatus DecodeThumbAddSPReg(MCInst &Inst, uint16_t Insn,
455                                 uint64_t Address, const void *Decoder);
456 static DecodeStatus DecodeThumbCPS(MCInst &Inst, uint16_t Insn,
457                                 uint64_t Address, const void *Decoder);
458 static DecodeStatus DecodeQADDInstruction(MCInst &Inst, unsigned Insn,
459                                 uint64_t Address, const void *Decoder);
460 static DecodeStatus DecodeThumbBLXOffset(MCInst &Inst, unsigned Insn,
461                                 uint64_t Address, const void *Decoder);
462 static DecodeStatus DecodeT2AddrModeImm12(MCInst &Inst, unsigned Val,
463                                 uint64_t Address, const void *Decoder);
464 static DecodeStatus DecodeThumbTableBranch(MCInst &Inst, unsigned Val,
465                                 uint64_t Address, const void *Decoder);
466 static DecodeStatus DecodeThumb2BCCInstruction(MCInst &Inst, unsigned Val,
467                                 uint64_t Address, const void *Decoder);
468 static DecodeStatus DecodeT2SOImm(MCInst &Inst, unsigned Val,
469                                 uint64_t Address, const void *Decoder);
470 static DecodeStatus DecodeThumbBCCTargetOperand(MCInst &Inst,unsigned Val,
471                                 uint64_t Address, const void *Decoder);
472 static DecodeStatus DecodeThumbBLTargetOperand(MCInst &Inst, unsigned Val,
473                                 uint64_t Address, const void *Decoder);
474 static DecodeStatus DecodeIT(MCInst &Inst, unsigned Val,
475                                 uint64_t Address, const void *Decoder);
476 static DecodeStatus DecodeT2LDRDPreInstruction(MCInst &Inst,unsigned Insn,
477                                uint64_t Address, const void *Decoder);
478 static DecodeStatus DecodeT2STRDPreInstruction(MCInst &Inst,unsigned Insn,
479                                uint64_t Address, const void *Decoder);
480 static DecodeStatus DecodeT2Adr(MCInst &Inst, unsigned Val,
481                                 uint64_t Address, const void *Decoder);
482 static DecodeStatus DecodeT2LdStPre(MCInst &Inst, unsigned Val,
483                                 uint64_t Address, const void *Decoder);
484 static DecodeStatus DecodeT2ShifterImmOperand(MCInst &Inst, unsigned Val,
485                                 uint64_t Address, const void *Decoder);
486 
487 static DecodeStatus DecodeLDR(MCInst &Inst, unsigned Val,
488                                 uint64_t Address, const void *Decoder);
489 static DecodeStatus DecoderForMRRC2AndMCRR2(MCInst &Inst, unsigned Val,
490                                             uint64_t Address, const void *Decoder);
491 static DecodeStatus DecodeForVMRSandVMSR(MCInst &Inst, unsigned Val,
492                                          uint64_t Address, const void *Decoder);
493 
494 template <bool isSigned, bool isNeg, bool zeroPermitted, int size>
495 static DecodeStatus DecodeBFLabelOperand(MCInst &Inst, unsigned val,
496                                          uint64_t Address, const void *Decoder);
497 static DecodeStatus DecodeBFAfterTargetOperand(MCInst &Inst, unsigned val,
498                                                uint64_t Address,
499                                                const void *Decoder);
500 static DecodeStatus DecodePredNoALOperand(MCInst &Inst, unsigned Val,
501                                           uint64_t Address,
502                                           const void *Decoder);
503 static DecodeStatus DecodeLOLoop(MCInst &Inst, unsigned Insn, uint64_t Address,
504                                  const void *Decoder);
505 static DecodeStatus DecodeLongShiftOperand(MCInst &Inst, unsigned Val,
506                                            uint64_t Address,
507                                            const void *Decoder);
508 static DecodeStatus DecodeVSCCLRM(MCInst &Inst, unsigned Insn, uint64_t Address,
509                                   const void *Decoder);
510 static DecodeStatus DecodeVPTMaskOperand(MCInst &Inst, unsigned Val,
511                                          uint64_t Address, const void *Decoder);
512 static DecodeStatus DecodeVpredROperand(MCInst &Inst, unsigned Val,
513                                         uint64_t Address, const void *Decoder);
514 static DecodeStatus DecodeRestrictedIPredicateOperand(MCInst &Inst, unsigned Val,
515                                                      uint64_t Address,
516                                                      const void *Decoder);
517 static DecodeStatus DecodeRestrictedSPredicateOperand(MCInst &Inst, unsigned Val,
518                                                      uint64_t Address,
519                                                      const void *Decoder);
520 static DecodeStatus DecodeRestrictedUPredicateOperand(MCInst &Inst, unsigned Val,
521                                                      uint64_t Address,
522                                                      const void *Decoder);
523 static DecodeStatus DecodeRestrictedFPPredicateOperand(MCInst &Inst,
524                                                        unsigned Val,
525                                                        uint64_t Address,
526                                                        const void *Decoder);
527 template<bool Writeback>
528 static DecodeStatus DecodeVSTRVLDR_SYSREG(MCInst &Inst, unsigned Insn,
529                                           uint64_t Address,
530                                           const void *Decoder);
531 template<int shift>
532 static DecodeStatus DecodeMVE_MEM_1_pre(MCInst &Inst, unsigned Val,
533                                         uint64_t Address, const void *Decoder);
534 template<int shift>
535 static DecodeStatus DecodeMVE_MEM_2_pre(MCInst &Inst, unsigned Val,
536                                         uint64_t Address, const void *Decoder);
537 template<int shift>
538 static DecodeStatus DecodeMVE_MEM_3_pre(MCInst &Inst, unsigned Val,
539                                         uint64_t Address, const void *Decoder);
540 template<unsigned MinLog, unsigned MaxLog>
541 static DecodeStatus DecodePowerTwoOperand(MCInst &Inst, unsigned Val,
542                                           uint64_t Address,
543                                           const void *Decoder);
544 template <int shift>
545 static DecodeStatus DecodeExpandedImmOperand(MCInst &Inst, unsigned Val,
546                                              uint64_t Address,
547                                              const void *Decoder);
548 template<unsigned start>
549 static DecodeStatus DecodeMVEPairVectorIndexOperand(MCInst &Inst, unsigned Val,
550                                                     uint64_t Address,
551                                                     const void *Decoder);
552 static DecodeStatus DecodeMVEVMOVQtoDReg(MCInst &Inst, unsigned Insn,
553                                          uint64_t Address,
554                                          const void *Decoder);
555 static DecodeStatus DecodeMVEVMOVDRegtoQ(MCInst &Inst, unsigned Insn,
556                                          uint64_t Address,
557                                          const void *Decoder);
558 static DecodeStatus DecodeMVEVCVTt1fp(MCInst &Inst, unsigned Insn,
559                                       uint64_t Address, const void *Decoder);
560 typedef DecodeStatus OperandDecoder(MCInst &Inst, unsigned Val,
561                                     uint64_t Address, const void *Decoder);
562 template<bool scalar, OperandDecoder predicate_decoder>
563 static DecodeStatus DecodeMVEVCMP(MCInst &Inst, unsigned Insn,
564                                   uint64_t Address, const void *Decoder);
565 static DecodeStatus DecodeMveVCTP(MCInst &Inst, unsigned Insn,
566                                   uint64_t Address, const void *Decoder);
567 static DecodeStatus DecodeMVEVPNOT(MCInst &Inst, unsigned Insn,
568                                    uint64_t Address, const void *Decoder);
569 static DecodeStatus DecodeMVEOverlappingLongShift(MCInst &Inst, unsigned Insn,
570                                                   uint64_t Address,
571                                                   const void *Decoder);
572 static DecodeStatus DecodeT2AddSubSPImm(MCInst &Inst, unsigned Insn,
573                                         uint64_t Address, const void *Decoder);
574 
575 #include "ARMGenDisassemblerTables.inc"
576 
577 static MCDisassembler *createARMDisassembler(const Target &T,
578                                              const MCSubtargetInfo &STI,
579                                              MCContext &Ctx) {
580   return new ARMDisassembler(STI, Ctx);
581 }
582 
583 // Post-decoding checks
584 static DecodeStatus checkDecodedInstruction(MCInst &MI, uint64_t &Size,
585                                             uint64_t Address, raw_ostream &OS,
586                                             raw_ostream &CS,
587                                             uint32_t Insn,
588                                             DecodeStatus Result) {
589   switch (MI.getOpcode()) {
590     case ARM::HVC: {
591       // HVC is undefined if condition = 0xf otherwise upredictable
592       // if condition != 0xe
593       uint32_t Cond = (Insn >> 28) & 0xF;
594       if (Cond == 0xF)
595         return MCDisassembler::Fail;
596       if (Cond != 0xE)
597         return MCDisassembler::SoftFail;
598       return Result;
599     }
600     case ARM::t2ADDri:
601     case ARM::t2ADDri12:
602     case ARM::t2ADDrr:
603     case ARM::t2ADDrs:
604     case ARM::t2SUBri:
605     case ARM::t2SUBri12:
606     case ARM::t2SUBrr:
607     case ARM::t2SUBrs:
608       if (MI.getOperand(0).getReg() == ARM::SP &&
609           MI.getOperand(1).getReg() != ARM::SP)
610         return MCDisassembler::SoftFail;
611       return Result;
612     default: return Result;
613   }
614 }
615 
616 DecodeStatus ARMDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
617                                              ArrayRef<uint8_t> Bytes,
618                                              uint64_t Address, raw_ostream &OS,
619                                              raw_ostream &CS) const {
620   if (STI.getFeatureBits()[ARM::ModeThumb])
621     return getThumbInstruction(MI, Size, Bytes, Address, OS, CS);
622   return getARMInstruction(MI, Size, Bytes, Address, OS, CS);
623 }
624 
625 DecodeStatus ARMDisassembler::getARMInstruction(MCInst &MI, uint64_t &Size,
626                                                 ArrayRef<uint8_t> Bytes,
627                                                 uint64_t Address,
628                                                 raw_ostream &OS,
629                                                 raw_ostream &CS) const {
630   CommentStream = &CS;
631 
632   assert(!STI.getFeatureBits()[ARM::ModeThumb] &&
633          "Asked to disassemble an ARM instruction but Subtarget is in Thumb "
634          "mode!");
635 
636   // We want to read exactly 4 bytes of data.
637   if (Bytes.size() < 4) {
638     Size = 0;
639     return MCDisassembler::Fail;
640   }
641 
642   // Encoded as a small-endian 32-bit word in the stream.
643   uint32_t Insn =
644       (Bytes[3] << 24) | (Bytes[2] << 16) | (Bytes[1] << 8) | (Bytes[0] << 0);
645 
646   // Calling the auto-generated decoder function.
647   DecodeStatus Result =
648       decodeInstruction(DecoderTableARM32, MI, Insn, Address, this, STI);
649   if (Result != MCDisassembler::Fail) {
650     Size = 4;
651     return checkDecodedInstruction(MI, Size, Address, OS, CS, Insn, Result);
652   }
653 
654   struct DecodeTable {
655     const uint8_t *P;
656     bool DecodePred;
657   };
658 
659   const DecodeTable Tables[] = {
660       {DecoderTableVFP32, false},      {DecoderTableVFPV832, false},
661       {DecoderTableNEONData32, true},  {DecoderTableNEONLoadStore32, true},
662       {DecoderTableNEONDup32, true},   {DecoderTablev8NEON32, false},
663       {DecoderTablev8Crypto32, false},
664   };
665 
666   for (auto Table : Tables) {
667     Result = decodeInstruction(Table.P, MI, Insn, Address, this, STI);
668     if (Result != MCDisassembler::Fail) {
669       Size = 4;
670       // Add a fake predicate operand, because we share these instruction
671       // definitions with Thumb2 where these instructions are predicable.
672       if (Table.DecodePred && !DecodePredicateOperand(MI, 0xE, Address, this))
673         return MCDisassembler::Fail;
674       return Result;
675     }
676   }
677 
678   Result =
679       decodeInstruction(DecoderTableCoProc32, MI, Insn, Address, this, STI);
680   if (Result != MCDisassembler::Fail) {
681     Size = 4;
682     return checkDecodedInstruction(MI, Size, Address, OS, CS, Insn, Result);
683   }
684 
685   Size = 4;
686   return MCDisassembler::Fail;
687 }
688 
689 namespace llvm {
690 
691 extern const MCInstrDesc ARMInsts[];
692 
693 } // end namespace llvm
694 
695 /// tryAddingSymbolicOperand - trys to add a symbolic operand in place of the
696 /// immediate Value in the MCInst.  The immediate Value has had any PC
697 /// adjustment made by the caller.  If the instruction is a branch instruction
698 /// then isBranch is true, else false.  If the getOpInfo() function was set as
699 /// part of the setupForSymbolicDisassembly() call then that function is called
700 /// to get any symbolic information at the Address for this instruction.  If
701 /// that returns non-zero then the symbolic information it returns is used to
702 /// create an MCExpr and that is added as an operand to the MCInst.  If
703 /// getOpInfo() returns zero and isBranch is true then a symbol look up for
704 /// Value is done and if a symbol is found an MCExpr is created with that, else
705 /// an MCExpr with Value is created.  This function returns true if it adds an
706 /// operand to the MCInst and false otherwise.
707 static bool tryAddingSymbolicOperand(uint64_t Address, int32_t Value,
708                                      bool isBranch, uint64_t InstSize,
709                                      MCInst &MI, const void *Decoder) {
710   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
711   // FIXME: Does it make sense for value to be negative?
712   return Dis->tryAddingSymbolicOperand(MI, (uint32_t)Value, Address, isBranch,
713                                        /* Offset */ 0, InstSize);
714 }
715 
716 /// tryAddingPcLoadReferenceComment - trys to add a comment as to what is being
717 /// referenced by a load instruction with the base register that is the Pc.
718 /// These can often be values in a literal pool near the Address of the
719 /// instruction.  The Address of the instruction and its immediate Value are
720 /// used as a possible literal pool entry.  The SymbolLookUp call back will
721 /// return the name of a symbol referenced by the literal pool's entry if
722 /// the referenced address is that of a symbol.  Or it will return a pointer to
723 /// a literal 'C' string if the referenced address of the literal pool's entry
724 /// is an address into a section with 'C' string literals.
725 static void tryAddingPcLoadReferenceComment(uint64_t Address, int Value,
726                                             const void *Decoder) {
727   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
728   Dis->tryAddingPcLoadReferenceComment(Value, Address);
729 }
730 
731 // Thumb1 instructions don't have explicit S bits.  Rather, they
732 // implicitly set CPSR.  Since it's not represented in the encoding, the
733 // auto-generated decoder won't inject the CPSR operand.  We need to fix
734 // that as a post-pass.
735 static void AddThumb1SBit(MCInst &MI, bool InITBlock) {
736   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
737   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
738   MCInst::iterator I = MI.begin();
739   for (unsigned i = 0; i < NumOps; ++i, ++I) {
740     if (I == MI.end()) break;
741     if (OpInfo[i].isOptionalDef() && OpInfo[i].RegClass == ARM::CCRRegClassID) {
742       if (i > 0 && OpInfo[i-1].isPredicate()) continue;
743       MI.insert(I, MCOperand::createReg(InITBlock ? 0 : ARM::CPSR));
744       return;
745     }
746   }
747 
748   MI.insert(I, MCOperand::createReg(InITBlock ? 0 : ARM::CPSR));
749 }
750 
751 static bool isVectorPredicable(unsigned Opcode) {
752   const MCOperandInfo *OpInfo = ARMInsts[Opcode].OpInfo;
753   unsigned short NumOps = ARMInsts[Opcode].NumOperands;
754   for (unsigned i = 0; i < NumOps; ++i) {
755     if (ARM::isVpred(OpInfo[i].OperandType))
756       return true;
757   }
758   return false;
759 }
760 
761 // Most Thumb instructions don't have explicit predicates in the
762 // encoding, but rather get their predicates from IT context.  We need
763 // to fix up the predicate operands using this context information as a
764 // post-pass.
765 MCDisassembler::DecodeStatus
766 ARMDisassembler::AddThumbPredicate(MCInst &MI) const {
767   MCDisassembler::DecodeStatus S = Success;
768 
769   const FeatureBitset &FeatureBits = getSubtargetInfo().getFeatureBits();
770 
771   // A few instructions actually have predicates encoded in them.  Don't
772   // try to overwrite it if we're seeing one of those.
773   switch (MI.getOpcode()) {
774     case ARM::tBcc:
775     case ARM::t2Bcc:
776     case ARM::tCBZ:
777     case ARM::tCBNZ:
778     case ARM::tCPS:
779     case ARM::t2CPS3p:
780     case ARM::t2CPS2p:
781     case ARM::t2CPS1p:
782     case ARM::t2CSEL:
783     case ARM::t2CSINC:
784     case ARM::t2CSINV:
785     case ARM::t2CSNEG:
786     case ARM::tMOVSr:
787     case ARM::tSETEND:
788       // Some instructions (mostly conditional branches) are not
789       // allowed in IT blocks.
790       if (ITBlock.instrInITBlock())
791         S = SoftFail;
792       else
793         return Success;
794       break;
795     case ARM::t2HINT:
796       if (MI.getOperand(0).getImm() == 0x10 && (FeatureBits[ARM::FeatureRAS]) != 0)
797         S = SoftFail;
798       break;
799     case ARM::tB:
800     case ARM::t2B:
801     case ARM::t2TBB:
802     case ARM::t2TBH:
803       // Some instructions (mostly unconditional branches) can
804       // only appears at the end of, or outside of, an IT.
805       if (ITBlock.instrInITBlock() && !ITBlock.instrLastInITBlock())
806         S = SoftFail;
807       break;
808     default:
809       break;
810   }
811 
812   // Warn on non-VPT predicable instruction in a VPT block and a VPT
813   // predicable instruction in an IT block
814   if ((!isVectorPredicable(MI.getOpcode()) && VPTBlock.instrInVPTBlock()) ||
815        (isVectorPredicable(MI.getOpcode()) && ITBlock.instrInITBlock()))
816     S = SoftFail;
817 
818   // If we're in an IT/VPT block, base the predicate on that.  Otherwise,
819   // assume a predicate of AL.
820   unsigned CC = ARMCC::AL;
821   unsigned VCC = ARMVCC::None;
822   if (ITBlock.instrInITBlock()) {
823     CC = ITBlock.getITCC();
824     ITBlock.advanceITState();
825   } else if (VPTBlock.instrInVPTBlock()) {
826     VCC = VPTBlock.getVPTPred();
827     VPTBlock.advanceVPTState();
828   }
829 
830   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
831   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
832 
833   MCInst::iterator CCI = MI.begin();
834   for (unsigned i = 0; i < NumOps; ++i, ++CCI) {
835     if (OpInfo[i].isPredicate() || CCI == MI.end()) break;
836   }
837 
838   if (ARMInsts[MI.getOpcode()].isPredicable()) {
839     CCI = MI.insert(CCI, MCOperand::createImm(CC));
840     ++CCI;
841     if (CC == ARMCC::AL)
842       MI.insert(CCI, MCOperand::createReg(0));
843     else
844       MI.insert(CCI, MCOperand::createReg(ARM::CPSR));
845   } else if (CC != ARMCC::AL) {
846     Check(S, SoftFail);
847   }
848 
849   MCInst::iterator VCCI = MI.begin();
850   unsigned VCCPos;
851   for (VCCPos = 0; VCCPos < NumOps; ++VCCPos, ++VCCI) {
852     if (ARM::isVpred(OpInfo[VCCPos].OperandType) || VCCI == MI.end()) break;
853   }
854 
855   if (isVectorPredicable(MI.getOpcode())) {
856     VCCI = MI.insert(VCCI, MCOperand::createImm(VCC));
857     ++VCCI;
858     if (VCC == ARMVCC::None)
859       MI.insert(VCCI, MCOperand::createReg(0));
860     else
861       MI.insert(VCCI, MCOperand::createReg(ARM::P0));
862     if (OpInfo[VCCPos].OperandType == ARM::OPERAND_VPRED_R) {
863       int TiedOp = ARMInsts[MI.getOpcode()].getOperandConstraint(
864         VCCPos + 2, MCOI::TIED_TO);
865       assert(TiedOp >= 0 &&
866              "Inactive register in vpred_r is not tied to an output!");
867       MI.insert(VCCI, MI.getOperand(TiedOp));
868     }
869   } else if (VCC != ARMVCC::None) {
870     Check(S, SoftFail);
871   }
872 
873   return S;
874 }
875 
876 // Thumb VFP instructions are a special case.  Because we share their
877 // encodings between ARM and Thumb modes, and they are predicable in ARM
878 // mode, the auto-generated decoder will give them an (incorrect)
879 // predicate operand.  We need to rewrite these operands based on the IT
880 // context as a post-pass.
881 void ARMDisassembler::UpdateThumbVFPPredicate(
882   DecodeStatus &S, MCInst &MI) const {
883   unsigned CC;
884   CC = ITBlock.getITCC();
885   if (CC == 0xF)
886     CC = ARMCC::AL;
887   if (ITBlock.instrInITBlock())
888     ITBlock.advanceITState();
889   else if (VPTBlock.instrInVPTBlock()) {
890     CC = VPTBlock.getVPTPred();
891     VPTBlock.advanceVPTState();
892   }
893 
894   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
895   MCInst::iterator I = MI.begin();
896   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
897   for (unsigned i = 0; i < NumOps; ++i, ++I) {
898     if (OpInfo[i].isPredicate() ) {
899       if (CC != ARMCC::AL && !ARMInsts[MI.getOpcode()].isPredicable())
900         Check(S, SoftFail);
901       I->setImm(CC);
902       ++I;
903       if (CC == ARMCC::AL)
904         I->setReg(0);
905       else
906         I->setReg(ARM::CPSR);
907       return;
908     }
909   }
910 }
911 
912 DecodeStatus ARMDisassembler::getThumbInstruction(MCInst &MI, uint64_t &Size,
913                                                   ArrayRef<uint8_t> Bytes,
914                                                   uint64_t Address,
915                                                   raw_ostream &OS,
916                                                   raw_ostream &CS) const {
917   CommentStream = &CS;
918 
919   assert(STI.getFeatureBits()[ARM::ModeThumb] &&
920          "Asked to disassemble in Thumb mode but Subtarget is in ARM mode!");
921 
922   // We want to read exactly 2 bytes of data.
923   if (Bytes.size() < 2) {
924     Size = 0;
925     return MCDisassembler::Fail;
926   }
927 
928   uint16_t Insn16 = (Bytes[1] << 8) | Bytes[0];
929   DecodeStatus Result =
930       decodeInstruction(DecoderTableThumb16, MI, Insn16, Address, this, STI);
931   if (Result != MCDisassembler::Fail) {
932     Size = 2;
933     Check(Result, AddThumbPredicate(MI));
934     return Result;
935   }
936 
937   Result = decodeInstruction(DecoderTableThumbSBit16, MI, Insn16, Address, this,
938                              STI);
939   if (Result) {
940     Size = 2;
941     bool InITBlock = ITBlock.instrInITBlock();
942     Check(Result, AddThumbPredicate(MI));
943     AddThumb1SBit(MI, InITBlock);
944     return Result;
945   }
946 
947   Result =
948       decodeInstruction(DecoderTableThumb216, MI, Insn16, Address, this, STI);
949   if (Result != MCDisassembler::Fail) {
950     Size = 2;
951 
952     // Nested IT blocks are UNPREDICTABLE.  Must be checked before we add
953     // the Thumb predicate.
954     if (MI.getOpcode() == ARM::t2IT && ITBlock.instrInITBlock())
955       Result = MCDisassembler::SoftFail;
956 
957     Check(Result, AddThumbPredicate(MI));
958 
959     // If we find an IT instruction, we need to parse its condition
960     // code and mask operands so that we can apply them correctly
961     // to the subsequent instructions.
962     if (MI.getOpcode() == ARM::t2IT) {
963       unsigned Firstcond = MI.getOperand(0).getImm();
964       unsigned Mask = MI.getOperand(1).getImm();
965       ITBlock.setITState(Firstcond, Mask);
966 
967       // An IT instruction that would give a 'NV' predicate is unpredictable.
968       if (Firstcond == ARMCC::AL && !isPowerOf2_32(Mask))
969         CS << "unpredictable IT predicate sequence";
970     }
971 
972     return Result;
973   }
974 
975   // We want to read exactly 4 bytes of data.
976   if (Bytes.size() < 4) {
977     Size = 0;
978     return MCDisassembler::Fail;
979   }
980 
981   uint32_t Insn32 =
982       (Bytes[3] << 8) | (Bytes[2] << 0) | (Bytes[1] << 24) | (Bytes[0] << 16);
983 
984   Result =
985       decodeInstruction(DecoderTableMVE32, MI, Insn32, Address, this, STI);
986   if (Result != MCDisassembler::Fail) {
987     Size = 4;
988 
989     // Nested VPT blocks are UNPREDICTABLE. Must be checked before we add
990     // the VPT predicate.
991     if (isVPTOpcode(MI.getOpcode()) && VPTBlock.instrInVPTBlock())
992       Result = MCDisassembler::SoftFail;
993 
994     Check(Result, AddThumbPredicate(MI));
995 
996     if (isVPTOpcode(MI.getOpcode())) {
997       unsigned Mask = MI.getOperand(0).getImm();
998       VPTBlock.setVPTState(Mask);
999     }
1000 
1001     return Result;
1002   }
1003 
1004   Result =
1005       decodeInstruction(DecoderTableThumb32, MI, Insn32, Address, this, STI);
1006   if (Result != MCDisassembler::Fail) {
1007     Size = 4;
1008     bool InITBlock = ITBlock.instrInITBlock();
1009     Check(Result, AddThumbPredicate(MI));
1010     AddThumb1SBit(MI, InITBlock);
1011     return Result;
1012   }
1013 
1014   Result =
1015       decodeInstruction(DecoderTableThumb232, MI, Insn32, Address, this, STI);
1016   if (Result != MCDisassembler::Fail) {
1017     Size = 4;
1018     Check(Result, AddThumbPredicate(MI));
1019     return checkDecodedInstruction(MI, Size, Address, OS, CS, Insn32, Result);
1020   }
1021 
1022   if (fieldFromInstruction(Insn32, 28, 4) == 0xE) {
1023     Result =
1024         decodeInstruction(DecoderTableVFP32, MI, Insn32, Address, this, STI);
1025     if (Result != MCDisassembler::Fail) {
1026       Size = 4;
1027       UpdateThumbVFPPredicate(Result, MI);
1028       return Result;
1029     }
1030   }
1031 
1032   Result =
1033       decodeInstruction(DecoderTableVFPV832, MI, Insn32, Address, this, STI);
1034   if (Result != MCDisassembler::Fail) {
1035     Size = 4;
1036     return Result;
1037   }
1038 
1039   if (fieldFromInstruction(Insn32, 28, 4) == 0xE) {
1040     Result = decodeInstruction(DecoderTableNEONDup32, MI, Insn32, Address, this,
1041                                STI);
1042     if (Result != MCDisassembler::Fail) {
1043       Size = 4;
1044       Check(Result, AddThumbPredicate(MI));
1045       return Result;
1046     }
1047   }
1048 
1049   if (fieldFromInstruction(Insn32, 24, 8) == 0xF9) {
1050     uint32_t NEONLdStInsn = Insn32;
1051     NEONLdStInsn &= 0xF0FFFFFF;
1052     NEONLdStInsn |= 0x04000000;
1053     Result = decodeInstruction(DecoderTableNEONLoadStore32, MI, NEONLdStInsn,
1054                                Address, this, STI);
1055     if (Result != MCDisassembler::Fail) {
1056       Size = 4;
1057       Check(Result, AddThumbPredicate(MI));
1058       return Result;
1059     }
1060   }
1061 
1062   if (fieldFromInstruction(Insn32, 24, 4) == 0xF) {
1063     uint32_t NEONDataInsn = Insn32;
1064     NEONDataInsn &= 0xF0FFFFFF; // Clear bits 27-24
1065     NEONDataInsn |= (NEONDataInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
1066     NEONDataInsn |= 0x12000000; // Set bits 28 and 25
1067     Result = decodeInstruction(DecoderTableNEONData32, MI, NEONDataInsn,
1068                                Address, this, STI);
1069     if (Result != MCDisassembler::Fail) {
1070       Size = 4;
1071       Check(Result, AddThumbPredicate(MI));
1072       return Result;
1073     }
1074 
1075     uint32_t NEONCryptoInsn = Insn32;
1076     NEONCryptoInsn &= 0xF0FFFFFF; // Clear bits 27-24
1077     NEONCryptoInsn |= (NEONCryptoInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
1078     NEONCryptoInsn |= 0x12000000; // Set bits 28 and 25
1079     Result = decodeInstruction(DecoderTablev8Crypto32, MI, NEONCryptoInsn,
1080                                Address, this, STI);
1081     if (Result != MCDisassembler::Fail) {
1082       Size = 4;
1083       return Result;
1084     }
1085 
1086     uint32_t NEONv8Insn = Insn32;
1087     NEONv8Insn &= 0xF3FFFFFF; // Clear bits 27-26
1088     Result = decodeInstruction(DecoderTablev8NEON32, MI, NEONv8Insn, Address,
1089                                this, STI);
1090     if (Result != MCDisassembler::Fail) {
1091       Size = 4;
1092       return Result;
1093     }
1094   }
1095 
1096   Result =
1097       decodeInstruction(DecoderTableThumb2CoProc32, MI, Insn32, Address, this, STI);
1098   if (Result != MCDisassembler::Fail) {
1099     Size = 4;
1100     Check(Result, AddThumbPredicate(MI));
1101     return Result;
1102   }
1103 
1104   Size = 0;
1105   return MCDisassembler::Fail;
1106 }
1107 
1108 extern "C" void LLVMInitializeARMDisassembler() {
1109   TargetRegistry::RegisterMCDisassembler(getTheARMLETarget(),
1110                                          createARMDisassembler);
1111   TargetRegistry::RegisterMCDisassembler(getTheARMBETarget(),
1112                                          createARMDisassembler);
1113   TargetRegistry::RegisterMCDisassembler(getTheThumbLETarget(),
1114                                          createARMDisassembler);
1115   TargetRegistry::RegisterMCDisassembler(getTheThumbBETarget(),
1116                                          createARMDisassembler);
1117 }
1118 
1119 static const uint16_t GPRDecoderTable[] = {
1120   ARM::R0, ARM::R1, ARM::R2, ARM::R3,
1121   ARM::R4, ARM::R5, ARM::R6, ARM::R7,
1122   ARM::R8, ARM::R9, ARM::R10, ARM::R11,
1123   ARM::R12, ARM::SP, ARM::LR, ARM::PC
1124 };
1125 
1126 static const uint16_t CLRMGPRDecoderTable[] = {
1127   ARM::R0, ARM::R1, ARM::R2, ARM::R3,
1128   ARM::R4, ARM::R5, ARM::R6, ARM::R7,
1129   ARM::R8, ARM::R9, ARM::R10, ARM::R11,
1130   ARM::R12, 0, ARM::LR, ARM::APSR
1131 };
1132 
1133 static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1134                                    uint64_t Address, const void *Decoder) {
1135   if (RegNo > 15)
1136     return MCDisassembler::Fail;
1137 
1138   unsigned Register = GPRDecoderTable[RegNo];
1139   Inst.addOperand(MCOperand::createReg(Register));
1140   return MCDisassembler::Success;
1141 }
1142 
1143 static DecodeStatus DecodeCLRMGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1144                                                uint64_t Address,
1145                                                const void *Decoder) {
1146   if (RegNo > 15)
1147     return MCDisassembler::Fail;
1148 
1149   unsigned Register = CLRMGPRDecoderTable[RegNo];
1150   if (Register == 0)
1151     return MCDisassembler::Fail;
1152 
1153   Inst.addOperand(MCOperand::createReg(Register));
1154   return MCDisassembler::Success;
1155 }
1156 
1157 static DecodeStatus
1158 DecodeGPRnopcRegisterClass(MCInst &Inst, unsigned RegNo,
1159                            uint64_t Address, const void *Decoder) {
1160   DecodeStatus S = MCDisassembler::Success;
1161 
1162   if (RegNo == 15)
1163     S = MCDisassembler::SoftFail;
1164 
1165   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1166 
1167   return S;
1168 }
1169 
1170 static DecodeStatus
1171 DecodeGPRwithAPSRRegisterClass(MCInst &Inst, unsigned RegNo,
1172                                uint64_t Address, const void *Decoder) {
1173   DecodeStatus S = MCDisassembler::Success;
1174 
1175   if (RegNo == 15)
1176   {
1177     Inst.addOperand(MCOperand::createReg(ARM::APSR_NZCV));
1178     return MCDisassembler::Success;
1179   }
1180 
1181   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1182   return S;
1183 }
1184 
1185 static DecodeStatus
1186 DecodeGPRwithZRRegisterClass(MCInst &Inst, unsigned RegNo,
1187                              uint64_t Address, const void *Decoder) {
1188   DecodeStatus S = MCDisassembler::Success;
1189 
1190   if (RegNo == 15)
1191   {
1192     Inst.addOperand(MCOperand::createReg(ARM::ZR));
1193     return MCDisassembler::Success;
1194   }
1195 
1196   if (RegNo == 13)
1197     Check(S, MCDisassembler::SoftFail);
1198 
1199   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1200   return S;
1201 }
1202 
1203 static DecodeStatus
1204 DecodeGPRwithZRnospRegisterClass(MCInst &Inst, unsigned RegNo,
1205                                  uint64_t Address, const void *Decoder) {
1206   DecodeStatus S = MCDisassembler::Success;
1207   if (RegNo == 13)
1208     return MCDisassembler::Fail;
1209   Check(S, DecodeGPRwithZRRegisterClass(Inst, RegNo, Address, Decoder));
1210   return S;
1211 }
1212 
1213 static DecodeStatus DecodetGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1214                                    uint64_t Address, const void *Decoder) {
1215   if (RegNo > 7)
1216     return MCDisassembler::Fail;
1217   return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
1218 }
1219 
1220 static const uint16_t GPRPairDecoderTable[] = {
1221   ARM::R0_R1, ARM::R2_R3,   ARM::R4_R5,  ARM::R6_R7,
1222   ARM::R8_R9, ARM::R10_R11, ARM::R12_SP
1223 };
1224 
1225 static DecodeStatus DecodeGPRPairRegisterClass(MCInst &Inst, unsigned RegNo,
1226                                    uint64_t Address, const void *Decoder) {
1227   DecodeStatus S = MCDisassembler::Success;
1228 
1229   if (RegNo > 13)
1230     return MCDisassembler::Fail;
1231 
1232   if ((RegNo & 1) || RegNo == 0xe)
1233      S = MCDisassembler::SoftFail;
1234 
1235   unsigned RegisterPair = GPRPairDecoderTable[RegNo/2];
1236   Inst.addOperand(MCOperand::createReg(RegisterPair));
1237   return S;
1238 }
1239 
1240 static DecodeStatus DecodeGPRspRegisterClass(MCInst &Inst, unsigned RegNo,
1241                                              uint64_t Address,
1242                                              const void *Decoder) {
1243   if (RegNo != 13)
1244     return MCDisassembler::Fail;
1245 
1246   unsigned Register = GPRDecoderTable[RegNo];
1247   Inst.addOperand(MCOperand::createReg(Register));
1248   return MCDisassembler::Success;
1249 }
1250 
1251 static DecodeStatus DecodetcGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1252                                    uint64_t Address, const void *Decoder) {
1253   unsigned Register = 0;
1254   switch (RegNo) {
1255     case 0:
1256       Register = ARM::R0;
1257       break;
1258     case 1:
1259       Register = ARM::R1;
1260       break;
1261     case 2:
1262       Register = ARM::R2;
1263       break;
1264     case 3:
1265       Register = ARM::R3;
1266       break;
1267     case 9:
1268       Register = ARM::R9;
1269       break;
1270     case 12:
1271       Register = ARM::R12;
1272       break;
1273     default:
1274       return MCDisassembler::Fail;
1275     }
1276 
1277   Inst.addOperand(MCOperand::createReg(Register));
1278   return MCDisassembler::Success;
1279 }
1280 
1281 static DecodeStatus DecoderGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1282                                    uint64_t Address, const void *Decoder) {
1283   DecodeStatus S = MCDisassembler::Success;
1284 
1285   const FeatureBitset &featureBits =
1286     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1287 
1288   if ((RegNo == 13 && !featureBits[ARM::HasV8Ops]) || RegNo == 15)
1289     S = MCDisassembler::SoftFail;
1290 
1291   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1292   return S;
1293 }
1294 
1295 static const uint16_t SPRDecoderTable[] = {
1296      ARM::S0,  ARM::S1,  ARM::S2,  ARM::S3,
1297      ARM::S4,  ARM::S5,  ARM::S6,  ARM::S7,
1298      ARM::S8,  ARM::S9, ARM::S10, ARM::S11,
1299     ARM::S12, ARM::S13, ARM::S14, ARM::S15,
1300     ARM::S16, ARM::S17, ARM::S18, ARM::S19,
1301     ARM::S20, ARM::S21, ARM::S22, ARM::S23,
1302     ARM::S24, ARM::S25, ARM::S26, ARM::S27,
1303     ARM::S28, ARM::S29, ARM::S30, ARM::S31
1304 };
1305 
1306 static DecodeStatus DecodeSPRRegisterClass(MCInst &Inst, unsigned RegNo,
1307                                    uint64_t Address, const void *Decoder) {
1308   if (RegNo > 31)
1309     return MCDisassembler::Fail;
1310 
1311   unsigned Register = SPRDecoderTable[RegNo];
1312   Inst.addOperand(MCOperand::createReg(Register));
1313   return MCDisassembler::Success;
1314 }
1315 
1316 static DecodeStatus DecodeHPRRegisterClass(MCInst &Inst, unsigned RegNo,
1317                                    uint64_t Address, const void *Decoder) {
1318   return DecodeSPRRegisterClass(Inst, RegNo, Address, Decoder);
1319 }
1320 
1321 static const uint16_t DPRDecoderTable[] = {
1322      ARM::D0,  ARM::D1,  ARM::D2,  ARM::D3,
1323      ARM::D4,  ARM::D5,  ARM::D6,  ARM::D7,
1324      ARM::D8,  ARM::D9, ARM::D10, ARM::D11,
1325     ARM::D12, ARM::D13, ARM::D14, ARM::D15,
1326     ARM::D16, ARM::D17, ARM::D18, ARM::D19,
1327     ARM::D20, ARM::D21, ARM::D22, ARM::D23,
1328     ARM::D24, ARM::D25, ARM::D26, ARM::D27,
1329     ARM::D28, ARM::D29, ARM::D30, ARM::D31
1330 };
1331 
1332 static DecodeStatus DecodeDPRRegisterClass(MCInst &Inst, unsigned RegNo,
1333                                    uint64_t Address, const void *Decoder) {
1334   const FeatureBitset &featureBits =
1335     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1336 
1337   bool hasD32 = featureBits[ARM::FeatureD32];
1338 
1339   if (RegNo > 31 || (!hasD32 && RegNo > 15))
1340     return MCDisassembler::Fail;
1341 
1342   unsigned Register = DPRDecoderTable[RegNo];
1343   Inst.addOperand(MCOperand::createReg(Register));
1344   return MCDisassembler::Success;
1345 }
1346 
1347 static DecodeStatus DecodeDPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
1348                                    uint64_t Address, const void *Decoder) {
1349   if (RegNo > 7)
1350     return MCDisassembler::Fail;
1351   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
1352 }
1353 
1354 static DecodeStatus DecodeSPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
1355                                    uint64_t Address, const void *Decoder) {
1356   if (RegNo > 15)
1357     return MCDisassembler::Fail;
1358   return DecodeSPRRegisterClass(Inst, RegNo, Address, Decoder);
1359 }
1360 
1361 static DecodeStatus
1362 DecodeDPR_VFP2RegisterClass(MCInst &Inst, unsigned RegNo,
1363                             uint64_t Address, const void *Decoder) {
1364   if (RegNo > 15)
1365     return MCDisassembler::Fail;
1366   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
1367 }
1368 
1369 static const uint16_t QPRDecoderTable[] = {
1370      ARM::Q0,  ARM::Q1,  ARM::Q2,  ARM::Q3,
1371      ARM::Q4,  ARM::Q5,  ARM::Q6,  ARM::Q7,
1372      ARM::Q8,  ARM::Q9, ARM::Q10, ARM::Q11,
1373     ARM::Q12, ARM::Q13, ARM::Q14, ARM::Q15
1374 };
1375 
1376 static DecodeStatus DecodeQPRRegisterClass(MCInst &Inst, unsigned RegNo,
1377                                    uint64_t Address, const void *Decoder) {
1378   if (RegNo > 31 || (RegNo & 1) != 0)
1379     return MCDisassembler::Fail;
1380   RegNo >>= 1;
1381 
1382   unsigned Register = QPRDecoderTable[RegNo];
1383   Inst.addOperand(MCOperand::createReg(Register));
1384   return MCDisassembler::Success;
1385 }
1386 
1387 static const uint16_t DPairDecoderTable[] = {
1388   ARM::Q0,  ARM::D1_D2,   ARM::Q1,  ARM::D3_D4,   ARM::Q2,  ARM::D5_D6,
1389   ARM::Q3,  ARM::D7_D8,   ARM::Q4,  ARM::D9_D10,  ARM::Q5,  ARM::D11_D12,
1390   ARM::Q6,  ARM::D13_D14, ARM::Q7,  ARM::D15_D16, ARM::Q8,  ARM::D17_D18,
1391   ARM::Q9,  ARM::D19_D20, ARM::Q10, ARM::D21_D22, ARM::Q11, ARM::D23_D24,
1392   ARM::Q12, ARM::D25_D26, ARM::Q13, ARM::D27_D28, ARM::Q14, ARM::D29_D30,
1393   ARM::Q15
1394 };
1395 
1396 static DecodeStatus DecodeDPairRegisterClass(MCInst &Inst, unsigned RegNo,
1397                                    uint64_t Address, const void *Decoder) {
1398   if (RegNo > 30)
1399     return MCDisassembler::Fail;
1400 
1401   unsigned Register = DPairDecoderTable[RegNo];
1402   Inst.addOperand(MCOperand::createReg(Register));
1403   return MCDisassembler::Success;
1404 }
1405 
1406 static const uint16_t DPairSpacedDecoderTable[] = {
1407   ARM::D0_D2,   ARM::D1_D3,   ARM::D2_D4,   ARM::D3_D5,
1408   ARM::D4_D6,   ARM::D5_D7,   ARM::D6_D8,   ARM::D7_D9,
1409   ARM::D8_D10,  ARM::D9_D11,  ARM::D10_D12, ARM::D11_D13,
1410   ARM::D12_D14, ARM::D13_D15, ARM::D14_D16, ARM::D15_D17,
1411   ARM::D16_D18, ARM::D17_D19, ARM::D18_D20, ARM::D19_D21,
1412   ARM::D20_D22, ARM::D21_D23, ARM::D22_D24, ARM::D23_D25,
1413   ARM::D24_D26, ARM::D25_D27, ARM::D26_D28, ARM::D27_D29,
1414   ARM::D28_D30, ARM::D29_D31
1415 };
1416 
1417 static DecodeStatus DecodeDPairSpacedRegisterClass(MCInst &Inst,
1418                                                    unsigned RegNo,
1419                                                    uint64_t Address,
1420                                                    const void *Decoder) {
1421   if (RegNo > 29)
1422     return MCDisassembler::Fail;
1423 
1424   unsigned Register = DPairSpacedDecoderTable[RegNo];
1425   Inst.addOperand(MCOperand::createReg(Register));
1426   return MCDisassembler::Success;
1427 }
1428 
1429 static DecodeStatus DecodePredicateOperand(MCInst &Inst, unsigned Val,
1430                                uint64_t Address, const void *Decoder) {
1431   DecodeStatus S = MCDisassembler::Success;
1432   if (Val == 0xF) return MCDisassembler::Fail;
1433   // AL predicate is not allowed on Thumb1 branches.
1434   if (Inst.getOpcode() == ARM::tBcc && Val == 0xE)
1435     return MCDisassembler::Fail;
1436   if (Val != ARMCC::AL && !ARMInsts[Inst.getOpcode()].isPredicable())
1437     Check(S, MCDisassembler::SoftFail);
1438   Inst.addOperand(MCOperand::createImm(Val));
1439   if (Val == ARMCC::AL) {
1440     Inst.addOperand(MCOperand::createReg(0));
1441   } else
1442     Inst.addOperand(MCOperand::createReg(ARM::CPSR));
1443   return S;
1444 }
1445 
1446 static DecodeStatus DecodeCCOutOperand(MCInst &Inst, unsigned Val,
1447                                uint64_t Address, const void *Decoder) {
1448   if (Val)
1449     Inst.addOperand(MCOperand::createReg(ARM::CPSR));
1450   else
1451     Inst.addOperand(MCOperand::createReg(0));
1452   return MCDisassembler::Success;
1453 }
1454 
1455 static DecodeStatus DecodeSORegImmOperand(MCInst &Inst, unsigned Val,
1456                                uint64_t Address, const void *Decoder) {
1457   DecodeStatus S = MCDisassembler::Success;
1458 
1459   unsigned Rm = fieldFromInstruction(Val, 0, 4);
1460   unsigned type = fieldFromInstruction(Val, 5, 2);
1461   unsigned imm = fieldFromInstruction(Val, 7, 5);
1462 
1463   // Register-immediate
1464   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
1465     return MCDisassembler::Fail;
1466 
1467   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1468   switch (type) {
1469     case 0:
1470       Shift = ARM_AM::lsl;
1471       break;
1472     case 1:
1473       Shift = ARM_AM::lsr;
1474       break;
1475     case 2:
1476       Shift = ARM_AM::asr;
1477       break;
1478     case 3:
1479       Shift = ARM_AM::ror;
1480       break;
1481   }
1482 
1483   if (Shift == ARM_AM::ror && imm == 0)
1484     Shift = ARM_AM::rrx;
1485 
1486   unsigned Op = Shift | (imm << 3);
1487   Inst.addOperand(MCOperand::createImm(Op));
1488 
1489   return S;
1490 }
1491 
1492 static DecodeStatus DecodeSORegRegOperand(MCInst &Inst, unsigned Val,
1493                                uint64_t Address, const void *Decoder) {
1494   DecodeStatus S = MCDisassembler::Success;
1495 
1496   unsigned Rm = fieldFromInstruction(Val, 0, 4);
1497   unsigned type = fieldFromInstruction(Val, 5, 2);
1498   unsigned Rs = fieldFromInstruction(Val, 8, 4);
1499 
1500   // Register-register
1501   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1502     return MCDisassembler::Fail;
1503   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rs, Address, Decoder)))
1504     return MCDisassembler::Fail;
1505 
1506   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1507   switch (type) {
1508     case 0:
1509       Shift = ARM_AM::lsl;
1510       break;
1511     case 1:
1512       Shift = ARM_AM::lsr;
1513       break;
1514     case 2:
1515       Shift = ARM_AM::asr;
1516       break;
1517     case 3:
1518       Shift = ARM_AM::ror;
1519       break;
1520   }
1521 
1522   Inst.addOperand(MCOperand::createImm(Shift));
1523 
1524   return S;
1525 }
1526 
1527 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Val,
1528                                  uint64_t Address, const void *Decoder) {
1529   DecodeStatus S = MCDisassembler::Success;
1530 
1531   bool NeedDisjointWriteback = false;
1532   unsigned WritebackReg = 0;
1533   bool CLRM = false;
1534   switch (Inst.getOpcode()) {
1535   default:
1536     break;
1537   case ARM::LDMIA_UPD:
1538   case ARM::LDMDB_UPD:
1539   case ARM::LDMIB_UPD:
1540   case ARM::LDMDA_UPD:
1541   case ARM::t2LDMIA_UPD:
1542   case ARM::t2LDMDB_UPD:
1543   case ARM::t2STMIA_UPD:
1544   case ARM::t2STMDB_UPD:
1545     NeedDisjointWriteback = true;
1546     WritebackReg = Inst.getOperand(0).getReg();
1547     break;
1548   case ARM::t2CLRM:
1549     CLRM = true;
1550     break;
1551   }
1552 
1553   // Empty register lists are not allowed.
1554   if (Val == 0) return MCDisassembler::Fail;
1555   for (unsigned i = 0; i < 16; ++i) {
1556     if (Val & (1 << i)) {
1557       if (CLRM) {
1558         if (!Check(S, DecodeCLRMGPRRegisterClass(Inst, i, Address, Decoder))) {
1559           return MCDisassembler::Fail;
1560         }
1561       } else {
1562         if (!Check(S, DecodeGPRRegisterClass(Inst, i, Address, Decoder)))
1563           return MCDisassembler::Fail;
1564         // Writeback not allowed if Rn is in the target list.
1565         if (NeedDisjointWriteback && WritebackReg == Inst.end()[-1].getReg())
1566           Check(S, MCDisassembler::SoftFail);
1567       }
1568     }
1569   }
1570 
1571   return S;
1572 }
1573 
1574 static DecodeStatus DecodeSPRRegListOperand(MCInst &Inst, unsigned Val,
1575                                  uint64_t Address, const void *Decoder) {
1576   DecodeStatus S = MCDisassembler::Success;
1577 
1578   unsigned Vd = fieldFromInstruction(Val, 8, 5);
1579   unsigned regs = fieldFromInstruction(Val, 0, 8);
1580 
1581   // In case of unpredictable encoding, tweak the operands.
1582   if (regs == 0 || (Vd + regs) > 32) {
1583     regs = Vd + regs > 32 ? 32 - Vd : regs;
1584     regs = std::max( 1u, regs);
1585     S = MCDisassembler::SoftFail;
1586   }
1587 
1588   if (!Check(S, DecodeSPRRegisterClass(Inst, Vd, Address, Decoder)))
1589     return MCDisassembler::Fail;
1590   for (unsigned i = 0; i < (regs - 1); ++i) {
1591     if (!Check(S, DecodeSPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1592       return MCDisassembler::Fail;
1593   }
1594 
1595   return S;
1596 }
1597 
1598 static DecodeStatus DecodeDPRRegListOperand(MCInst &Inst, unsigned Val,
1599                                  uint64_t Address, const void *Decoder) {
1600   DecodeStatus S = MCDisassembler::Success;
1601 
1602   unsigned Vd = fieldFromInstruction(Val, 8, 5);
1603   unsigned regs = fieldFromInstruction(Val, 1, 7);
1604 
1605   // In case of unpredictable encoding, tweak the operands.
1606   if (regs == 0 || regs > 16 || (Vd + regs) > 32) {
1607     regs = Vd + regs > 32 ? 32 - Vd : regs;
1608     regs = std::max( 1u, regs);
1609     regs = std::min(16u, regs);
1610     S = MCDisassembler::SoftFail;
1611   }
1612 
1613   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
1614       return MCDisassembler::Fail;
1615   for (unsigned i = 0; i < (regs - 1); ++i) {
1616     if (!Check(S, DecodeDPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1617       return MCDisassembler::Fail;
1618   }
1619 
1620   return S;
1621 }
1622 
1623 static DecodeStatus DecodeBitfieldMaskOperand(MCInst &Inst, unsigned Val,
1624                                       uint64_t Address, const void *Decoder) {
1625   // This operand encodes a mask of contiguous zeros between a specified MSB
1626   // and LSB.  To decode it, we create the mask of all bits MSB-and-lower,
1627   // the mask of all bits LSB-and-lower, and then xor them to create
1628   // the mask of that's all ones on [msb, lsb].  Finally we not it to
1629   // create the final mask.
1630   unsigned msb = fieldFromInstruction(Val, 5, 5);
1631   unsigned lsb = fieldFromInstruction(Val, 0, 5);
1632 
1633   DecodeStatus S = MCDisassembler::Success;
1634   if (lsb > msb) {
1635     Check(S, MCDisassembler::SoftFail);
1636     // The check above will cause the warning for the "potentially undefined
1637     // instruction encoding" but we can't build a bad MCOperand value here
1638     // with a lsb > msb or else printing the MCInst will cause a crash.
1639     lsb = msb;
1640   }
1641 
1642   uint32_t msb_mask = 0xFFFFFFFF;
1643   if (msb != 31) msb_mask = (1U << (msb+1)) - 1;
1644   uint32_t lsb_mask = (1U << lsb) - 1;
1645 
1646   Inst.addOperand(MCOperand::createImm(~(msb_mask ^ lsb_mask)));
1647   return S;
1648 }
1649 
1650 static DecodeStatus DecodeCopMemInstruction(MCInst &Inst, unsigned Insn,
1651                                   uint64_t Address, const void *Decoder) {
1652   DecodeStatus S = MCDisassembler::Success;
1653 
1654   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1655   unsigned CRd = fieldFromInstruction(Insn, 12, 4);
1656   unsigned coproc = fieldFromInstruction(Insn, 8, 4);
1657   unsigned imm = fieldFromInstruction(Insn, 0, 8);
1658   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1659   unsigned U = fieldFromInstruction(Insn, 23, 1);
1660   const FeatureBitset &featureBits =
1661     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1662 
1663   switch (Inst.getOpcode()) {
1664     case ARM::LDC_OFFSET:
1665     case ARM::LDC_PRE:
1666     case ARM::LDC_POST:
1667     case ARM::LDC_OPTION:
1668     case ARM::LDCL_OFFSET:
1669     case ARM::LDCL_PRE:
1670     case ARM::LDCL_POST:
1671     case ARM::LDCL_OPTION:
1672     case ARM::STC_OFFSET:
1673     case ARM::STC_PRE:
1674     case ARM::STC_POST:
1675     case ARM::STC_OPTION:
1676     case ARM::STCL_OFFSET:
1677     case ARM::STCL_PRE:
1678     case ARM::STCL_POST:
1679     case ARM::STCL_OPTION:
1680     case ARM::t2LDC_OFFSET:
1681     case ARM::t2LDC_PRE:
1682     case ARM::t2LDC_POST:
1683     case ARM::t2LDC_OPTION:
1684     case ARM::t2LDCL_OFFSET:
1685     case ARM::t2LDCL_PRE:
1686     case ARM::t2LDCL_POST:
1687     case ARM::t2LDCL_OPTION:
1688     case ARM::t2STC_OFFSET:
1689     case ARM::t2STC_PRE:
1690     case ARM::t2STC_POST:
1691     case ARM::t2STC_OPTION:
1692     case ARM::t2STCL_OFFSET:
1693     case ARM::t2STCL_PRE:
1694     case ARM::t2STCL_POST:
1695     case ARM::t2STCL_OPTION:
1696     case ARM::t2LDC2_OFFSET:
1697     case ARM::t2LDC2L_OFFSET:
1698     case ARM::t2LDC2_PRE:
1699     case ARM::t2LDC2L_PRE:
1700     case ARM::t2STC2_OFFSET:
1701     case ARM::t2STC2L_OFFSET:
1702     case ARM::t2STC2_PRE:
1703     case ARM::t2STC2L_PRE:
1704     case ARM::LDC2_OFFSET:
1705     case ARM::LDC2L_OFFSET:
1706     case ARM::LDC2_PRE:
1707     case ARM::LDC2L_PRE:
1708     case ARM::STC2_OFFSET:
1709     case ARM::STC2L_OFFSET:
1710     case ARM::STC2_PRE:
1711     case ARM::STC2L_PRE:
1712     case ARM::t2LDC2_OPTION:
1713     case ARM::t2STC2_OPTION:
1714     case ARM::t2LDC2_POST:
1715     case ARM::t2LDC2L_POST:
1716     case ARM::t2STC2_POST:
1717     case ARM::t2STC2L_POST:
1718     case ARM::LDC2_POST:
1719     case ARM::LDC2L_POST:
1720     case ARM::STC2_POST:
1721     case ARM::STC2L_POST:
1722       if (coproc == 0xA || coproc == 0xB ||
1723           (featureBits[ARM::HasV8_1MMainlineOps] &&
1724            (coproc == 0x8 || coproc == 0x9 || coproc == 0xA || coproc == 0xB ||
1725             coproc == 0xE || coproc == 0xF)))
1726         return MCDisassembler::Fail;
1727       break;
1728     default:
1729       break;
1730   }
1731 
1732   if (featureBits[ARM::HasV8Ops] && (coproc != 14))
1733     return MCDisassembler::Fail;
1734 
1735   Inst.addOperand(MCOperand::createImm(coproc));
1736   Inst.addOperand(MCOperand::createImm(CRd));
1737   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1738     return MCDisassembler::Fail;
1739 
1740   switch (Inst.getOpcode()) {
1741     case ARM::t2LDC2_OFFSET:
1742     case ARM::t2LDC2L_OFFSET:
1743     case ARM::t2LDC2_PRE:
1744     case ARM::t2LDC2L_PRE:
1745     case ARM::t2STC2_OFFSET:
1746     case ARM::t2STC2L_OFFSET:
1747     case ARM::t2STC2_PRE:
1748     case ARM::t2STC2L_PRE:
1749     case ARM::LDC2_OFFSET:
1750     case ARM::LDC2L_OFFSET:
1751     case ARM::LDC2_PRE:
1752     case ARM::LDC2L_PRE:
1753     case ARM::STC2_OFFSET:
1754     case ARM::STC2L_OFFSET:
1755     case ARM::STC2_PRE:
1756     case ARM::STC2L_PRE:
1757     case ARM::t2LDC_OFFSET:
1758     case ARM::t2LDCL_OFFSET:
1759     case ARM::t2LDC_PRE:
1760     case ARM::t2LDCL_PRE:
1761     case ARM::t2STC_OFFSET:
1762     case ARM::t2STCL_OFFSET:
1763     case ARM::t2STC_PRE:
1764     case ARM::t2STCL_PRE:
1765     case ARM::LDC_OFFSET:
1766     case ARM::LDCL_OFFSET:
1767     case ARM::LDC_PRE:
1768     case ARM::LDCL_PRE:
1769     case ARM::STC_OFFSET:
1770     case ARM::STCL_OFFSET:
1771     case ARM::STC_PRE:
1772     case ARM::STCL_PRE:
1773       imm = ARM_AM::getAM5Opc(U ? ARM_AM::add : ARM_AM::sub, imm);
1774       Inst.addOperand(MCOperand::createImm(imm));
1775       break;
1776     case ARM::t2LDC2_POST:
1777     case ARM::t2LDC2L_POST:
1778     case ARM::t2STC2_POST:
1779     case ARM::t2STC2L_POST:
1780     case ARM::LDC2_POST:
1781     case ARM::LDC2L_POST:
1782     case ARM::STC2_POST:
1783     case ARM::STC2L_POST:
1784     case ARM::t2LDC_POST:
1785     case ARM::t2LDCL_POST:
1786     case ARM::t2STC_POST:
1787     case ARM::t2STCL_POST:
1788     case ARM::LDC_POST:
1789     case ARM::LDCL_POST:
1790     case ARM::STC_POST:
1791     case ARM::STCL_POST:
1792       imm |= U << 8;
1793       LLVM_FALLTHROUGH;
1794     default:
1795       // The 'option' variant doesn't encode 'U' in the immediate since
1796       // the immediate is unsigned [0,255].
1797       Inst.addOperand(MCOperand::createImm(imm));
1798       break;
1799   }
1800 
1801   switch (Inst.getOpcode()) {
1802     case ARM::LDC_OFFSET:
1803     case ARM::LDC_PRE:
1804     case ARM::LDC_POST:
1805     case ARM::LDC_OPTION:
1806     case ARM::LDCL_OFFSET:
1807     case ARM::LDCL_PRE:
1808     case ARM::LDCL_POST:
1809     case ARM::LDCL_OPTION:
1810     case ARM::STC_OFFSET:
1811     case ARM::STC_PRE:
1812     case ARM::STC_POST:
1813     case ARM::STC_OPTION:
1814     case ARM::STCL_OFFSET:
1815     case ARM::STCL_PRE:
1816     case ARM::STCL_POST:
1817     case ARM::STCL_OPTION:
1818       if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1819         return MCDisassembler::Fail;
1820       break;
1821     default:
1822       break;
1823   }
1824 
1825   return S;
1826 }
1827 
1828 static DecodeStatus
1829 DecodeAddrMode2IdxInstruction(MCInst &Inst, unsigned Insn,
1830                               uint64_t Address, const void *Decoder) {
1831   DecodeStatus S = MCDisassembler::Success;
1832 
1833   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1834   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
1835   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
1836   unsigned imm = fieldFromInstruction(Insn, 0, 12);
1837   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1838   unsigned reg = fieldFromInstruction(Insn, 25, 1);
1839   unsigned P = fieldFromInstruction(Insn, 24, 1);
1840   unsigned W = fieldFromInstruction(Insn, 21, 1);
1841 
1842   // On stores, the writeback operand precedes Rt.
1843   switch (Inst.getOpcode()) {
1844     case ARM::STR_POST_IMM:
1845     case ARM::STR_POST_REG:
1846     case ARM::STRB_POST_IMM:
1847     case ARM::STRB_POST_REG:
1848     case ARM::STRT_POST_REG:
1849     case ARM::STRT_POST_IMM:
1850     case ARM::STRBT_POST_REG:
1851     case ARM::STRBT_POST_IMM:
1852       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1853         return MCDisassembler::Fail;
1854       break;
1855     default:
1856       break;
1857   }
1858 
1859   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
1860     return MCDisassembler::Fail;
1861 
1862   // On loads, the writeback operand comes after Rt.
1863   switch (Inst.getOpcode()) {
1864     case ARM::LDR_POST_IMM:
1865     case ARM::LDR_POST_REG:
1866     case ARM::LDRB_POST_IMM:
1867     case ARM::LDRB_POST_REG:
1868     case ARM::LDRBT_POST_REG:
1869     case ARM::LDRBT_POST_IMM:
1870     case ARM::LDRT_POST_REG:
1871     case ARM::LDRT_POST_IMM:
1872       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1873         return MCDisassembler::Fail;
1874       break;
1875     default:
1876       break;
1877   }
1878 
1879   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1880     return MCDisassembler::Fail;
1881 
1882   ARM_AM::AddrOpc Op = ARM_AM::add;
1883   if (!fieldFromInstruction(Insn, 23, 1))
1884     Op = ARM_AM::sub;
1885 
1886   bool writeback = (P == 0) || (W == 1);
1887   unsigned idx_mode = 0;
1888   if (P && writeback)
1889     idx_mode = ARMII::IndexModePre;
1890   else if (!P && writeback)
1891     idx_mode = ARMII::IndexModePost;
1892 
1893   if (writeback && (Rn == 15 || Rn == Rt))
1894     S = MCDisassembler::SoftFail; // UNPREDICTABLE
1895 
1896   if (reg) {
1897     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1898       return MCDisassembler::Fail;
1899     ARM_AM::ShiftOpc Opc = ARM_AM::lsl;
1900     switch( fieldFromInstruction(Insn, 5, 2)) {
1901       case 0:
1902         Opc = ARM_AM::lsl;
1903         break;
1904       case 1:
1905         Opc = ARM_AM::lsr;
1906         break;
1907       case 2:
1908         Opc = ARM_AM::asr;
1909         break;
1910       case 3:
1911         Opc = ARM_AM::ror;
1912         break;
1913       default:
1914         return MCDisassembler::Fail;
1915     }
1916     unsigned amt = fieldFromInstruction(Insn, 7, 5);
1917     if (Opc == ARM_AM::ror && amt == 0)
1918       Opc = ARM_AM::rrx;
1919     unsigned imm = ARM_AM::getAM2Opc(Op, amt, Opc, idx_mode);
1920 
1921     Inst.addOperand(MCOperand::createImm(imm));
1922   } else {
1923     Inst.addOperand(MCOperand::createReg(0));
1924     unsigned tmp = ARM_AM::getAM2Opc(Op, imm, ARM_AM::lsl, idx_mode);
1925     Inst.addOperand(MCOperand::createImm(tmp));
1926   }
1927 
1928   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1929     return MCDisassembler::Fail;
1930 
1931   return S;
1932 }
1933 
1934 static DecodeStatus DecodeSORegMemOperand(MCInst &Inst, unsigned Val,
1935                                   uint64_t Address, const void *Decoder) {
1936   DecodeStatus S = MCDisassembler::Success;
1937 
1938   unsigned Rn = fieldFromInstruction(Val, 13, 4);
1939   unsigned Rm = fieldFromInstruction(Val,  0, 4);
1940   unsigned type = fieldFromInstruction(Val, 5, 2);
1941   unsigned imm = fieldFromInstruction(Val, 7, 5);
1942   unsigned U = fieldFromInstruction(Val, 12, 1);
1943 
1944   ARM_AM::ShiftOpc ShOp = ARM_AM::lsl;
1945   switch (type) {
1946     case 0:
1947       ShOp = ARM_AM::lsl;
1948       break;
1949     case 1:
1950       ShOp = ARM_AM::lsr;
1951       break;
1952     case 2:
1953       ShOp = ARM_AM::asr;
1954       break;
1955     case 3:
1956       ShOp = ARM_AM::ror;
1957       break;
1958   }
1959 
1960   if (ShOp == ARM_AM::ror && imm == 0)
1961     ShOp = ARM_AM::rrx;
1962 
1963   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1964     return MCDisassembler::Fail;
1965   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1966     return MCDisassembler::Fail;
1967   unsigned shift;
1968   if (U)
1969     shift = ARM_AM::getAM2Opc(ARM_AM::add, imm, ShOp);
1970   else
1971     shift = ARM_AM::getAM2Opc(ARM_AM::sub, imm, ShOp);
1972   Inst.addOperand(MCOperand::createImm(shift));
1973 
1974   return S;
1975 }
1976 
1977 static DecodeStatus
1978 DecodeAddrMode3Instruction(MCInst &Inst, unsigned Insn,
1979                            uint64_t Address, const void *Decoder) {
1980   DecodeStatus S = MCDisassembler::Success;
1981 
1982   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
1983   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1984   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
1985   unsigned type = fieldFromInstruction(Insn, 22, 1);
1986   unsigned imm = fieldFromInstruction(Insn, 8, 4);
1987   unsigned U = ((~fieldFromInstruction(Insn, 23, 1)) & 1) << 8;
1988   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1989   unsigned W = fieldFromInstruction(Insn, 21, 1);
1990   unsigned P = fieldFromInstruction(Insn, 24, 1);
1991   unsigned Rt2 = Rt + 1;
1992 
1993   bool writeback = (W == 1) | (P == 0);
1994 
1995   // For {LD,ST}RD, Rt must be even, else undefined.
1996   switch (Inst.getOpcode()) {
1997     case ARM::STRD:
1998     case ARM::STRD_PRE:
1999     case ARM::STRD_POST:
2000     case ARM::LDRD:
2001     case ARM::LDRD_PRE:
2002     case ARM::LDRD_POST:
2003       if (Rt & 0x1) S = MCDisassembler::SoftFail;
2004       break;
2005     default:
2006       break;
2007   }
2008   switch (Inst.getOpcode()) {
2009     case ARM::STRD:
2010     case ARM::STRD_PRE:
2011     case ARM::STRD_POST:
2012       if (P == 0 && W == 1)
2013         S = MCDisassembler::SoftFail;
2014 
2015       if (writeback && (Rn == 15 || Rn == Rt || Rn == Rt2))
2016         S = MCDisassembler::SoftFail;
2017       if (type && Rm == 15)
2018         S = MCDisassembler::SoftFail;
2019       if (Rt2 == 15)
2020         S = MCDisassembler::SoftFail;
2021       if (!type && fieldFromInstruction(Insn, 8, 4))
2022         S = MCDisassembler::SoftFail;
2023       break;
2024     case ARM::STRH:
2025     case ARM::STRH_PRE:
2026     case ARM::STRH_POST:
2027       if (Rt == 15)
2028         S = MCDisassembler::SoftFail;
2029       if (writeback && (Rn == 15 || Rn == Rt))
2030         S = MCDisassembler::SoftFail;
2031       if (!type && Rm == 15)
2032         S = MCDisassembler::SoftFail;
2033       break;
2034     case ARM::LDRD:
2035     case ARM::LDRD_PRE:
2036     case ARM::LDRD_POST:
2037       if (type && Rn == 15) {
2038         if (Rt2 == 15)
2039           S = MCDisassembler::SoftFail;
2040         break;
2041       }
2042       if (P == 0 && W == 1)
2043         S = MCDisassembler::SoftFail;
2044       if (!type && (Rt2 == 15 || Rm == 15 || Rm == Rt || Rm == Rt2))
2045         S = MCDisassembler::SoftFail;
2046       if (!type && writeback && Rn == 15)
2047         S = MCDisassembler::SoftFail;
2048       if (writeback && (Rn == Rt || Rn == Rt2))
2049         S = MCDisassembler::SoftFail;
2050       break;
2051     case ARM::LDRH:
2052     case ARM::LDRH_PRE:
2053     case ARM::LDRH_POST:
2054       if (type && Rn == 15) {
2055         if (Rt == 15)
2056           S = MCDisassembler::SoftFail;
2057         break;
2058       }
2059       if (Rt == 15)
2060         S = MCDisassembler::SoftFail;
2061       if (!type && Rm == 15)
2062         S = MCDisassembler::SoftFail;
2063       if (!type && writeback && (Rn == 15 || Rn == Rt))
2064         S = MCDisassembler::SoftFail;
2065       break;
2066     case ARM::LDRSH:
2067     case ARM::LDRSH_PRE:
2068     case ARM::LDRSH_POST:
2069     case ARM::LDRSB:
2070     case ARM::LDRSB_PRE:
2071     case ARM::LDRSB_POST:
2072       if (type && Rn == 15) {
2073         if (Rt == 15)
2074           S = MCDisassembler::SoftFail;
2075         break;
2076       }
2077       if (type && (Rt == 15 || (writeback && Rn == Rt)))
2078         S = MCDisassembler::SoftFail;
2079       if (!type && (Rt == 15 || Rm == 15))
2080         S = MCDisassembler::SoftFail;
2081       if (!type && writeback && (Rn == 15 || Rn == Rt))
2082         S = MCDisassembler::SoftFail;
2083       break;
2084     default:
2085       break;
2086   }
2087 
2088   if (writeback) { // Writeback
2089     if (P)
2090       U |= ARMII::IndexModePre << 9;
2091     else
2092       U |= ARMII::IndexModePost << 9;
2093 
2094     // On stores, the writeback operand precedes Rt.
2095     switch (Inst.getOpcode()) {
2096     case ARM::STRD:
2097     case ARM::STRD_PRE:
2098     case ARM::STRD_POST:
2099     case ARM::STRH:
2100     case ARM::STRH_PRE:
2101     case ARM::STRH_POST:
2102       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2103         return MCDisassembler::Fail;
2104       break;
2105     default:
2106       break;
2107     }
2108   }
2109 
2110   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
2111     return MCDisassembler::Fail;
2112   switch (Inst.getOpcode()) {
2113     case ARM::STRD:
2114     case ARM::STRD_PRE:
2115     case ARM::STRD_POST:
2116     case ARM::LDRD:
2117     case ARM::LDRD_PRE:
2118     case ARM::LDRD_POST:
2119       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder)))
2120         return MCDisassembler::Fail;
2121       break;
2122     default:
2123       break;
2124   }
2125 
2126   if (writeback) {
2127     // On loads, the writeback operand comes after Rt.
2128     switch (Inst.getOpcode()) {
2129     case ARM::LDRD:
2130     case ARM::LDRD_PRE:
2131     case ARM::LDRD_POST:
2132     case ARM::LDRH:
2133     case ARM::LDRH_PRE:
2134     case ARM::LDRH_POST:
2135     case ARM::LDRSH:
2136     case ARM::LDRSH_PRE:
2137     case ARM::LDRSH_POST:
2138     case ARM::LDRSB:
2139     case ARM::LDRSB_PRE:
2140     case ARM::LDRSB_POST:
2141     case ARM::LDRHTr:
2142     case ARM::LDRSBTr:
2143       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2144         return MCDisassembler::Fail;
2145       break;
2146     default:
2147       break;
2148     }
2149   }
2150 
2151   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2152     return MCDisassembler::Fail;
2153 
2154   if (type) {
2155     Inst.addOperand(MCOperand::createReg(0));
2156     Inst.addOperand(MCOperand::createImm(U | (imm << 4) | Rm));
2157   } else {
2158     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2159     return MCDisassembler::Fail;
2160     Inst.addOperand(MCOperand::createImm(U));
2161   }
2162 
2163   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2164     return MCDisassembler::Fail;
2165 
2166   return S;
2167 }
2168 
2169 static DecodeStatus DecodeRFEInstruction(MCInst &Inst, unsigned Insn,
2170                                  uint64_t Address, const void *Decoder) {
2171   DecodeStatus S = MCDisassembler::Success;
2172 
2173   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2174   unsigned mode = fieldFromInstruction(Insn, 23, 2);
2175 
2176   switch (mode) {
2177     case 0:
2178       mode = ARM_AM::da;
2179       break;
2180     case 1:
2181       mode = ARM_AM::ia;
2182       break;
2183     case 2:
2184       mode = ARM_AM::db;
2185       break;
2186     case 3:
2187       mode = ARM_AM::ib;
2188       break;
2189   }
2190 
2191   Inst.addOperand(MCOperand::createImm(mode));
2192   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2193     return MCDisassembler::Fail;
2194 
2195   return S;
2196 }
2197 
2198 static DecodeStatus DecodeQADDInstruction(MCInst &Inst, unsigned Insn,
2199                                uint64_t Address, const void *Decoder) {
2200   DecodeStatus S = MCDisassembler::Success;
2201 
2202   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2203   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2204   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2205   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2206 
2207   if (pred == 0xF)
2208     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
2209 
2210   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2211     return MCDisassembler::Fail;
2212   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
2213     return MCDisassembler::Fail;
2214   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
2215     return MCDisassembler::Fail;
2216   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2217     return MCDisassembler::Fail;
2218   return S;
2219 }
2220 
2221 static DecodeStatus DecodeMemMultipleWritebackInstruction(MCInst &Inst,
2222                                   unsigned Insn,
2223                                   uint64_t Address, const void *Decoder) {
2224   DecodeStatus S = MCDisassembler::Success;
2225 
2226   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2227   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2228   unsigned reglist = fieldFromInstruction(Insn, 0, 16);
2229 
2230   if (pred == 0xF) {
2231     // Ambiguous with RFE and SRS
2232     switch (Inst.getOpcode()) {
2233       case ARM::LDMDA:
2234         Inst.setOpcode(ARM::RFEDA);
2235         break;
2236       case ARM::LDMDA_UPD:
2237         Inst.setOpcode(ARM::RFEDA_UPD);
2238         break;
2239       case ARM::LDMDB:
2240         Inst.setOpcode(ARM::RFEDB);
2241         break;
2242       case ARM::LDMDB_UPD:
2243         Inst.setOpcode(ARM::RFEDB_UPD);
2244         break;
2245       case ARM::LDMIA:
2246         Inst.setOpcode(ARM::RFEIA);
2247         break;
2248       case ARM::LDMIA_UPD:
2249         Inst.setOpcode(ARM::RFEIA_UPD);
2250         break;
2251       case ARM::LDMIB:
2252         Inst.setOpcode(ARM::RFEIB);
2253         break;
2254       case ARM::LDMIB_UPD:
2255         Inst.setOpcode(ARM::RFEIB_UPD);
2256         break;
2257       case ARM::STMDA:
2258         Inst.setOpcode(ARM::SRSDA);
2259         break;
2260       case ARM::STMDA_UPD:
2261         Inst.setOpcode(ARM::SRSDA_UPD);
2262         break;
2263       case ARM::STMDB:
2264         Inst.setOpcode(ARM::SRSDB);
2265         break;
2266       case ARM::STMDB_UPD:
2267         Inst.setOpcode(ARM::SRSDB_UPD);
2268         break;
2269       case ARM::STMIA:
2270         Inst.setOpcode(ARM::SRSIA);
2271         break;
2272       case ARM::STMIA_UPD:
2273         Inst.setOpcode(ARM::SRSIA_UPD);
2274         break;
2275       case ARM::STMIB:
2276         Inst.setOpcode(ARM::SRSIB);
2277         break;
2278       case ARM::STMIB_UPD:
2279         Inst.setOpcode(ARM::SRSIB_UPD);
2280         break;
2281       default:
2282         return MCDisassembler::Fail;
2283     }
2284 
2285     // For stores (which become SRS's, the only operand is the mode.
2286     if (fieldFromInstruction(Insn, 20, 1) == 0) {
2287       // Check SRS encoding constraints
2288       if (!(fieldFromInstruction(Insn, 22, 1) == 1 &&
2289             fieldFromInstruction(Insn, 20, 1) == 0))
2290         return MCDisassembler::Fail;
2291 
2292       Inst.addOperand(
2293           MCOperand::createImm(fieldFromInstruction(Insn, 0, 4)));
2294       return S;
2295     }
2296 
2297     return DecodeRFEInstruction(Inst, Insn, Address, Decoder);
2298   }
2299 
2300   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2301     return MCDisassembler::Fail;
2302   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2303     return MCDisassembler::Fail; // Tied
2304   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2305     return MCDisassembler::Fail;
2306   if (!Check(S, DecodeRegListOperand(Inst, reglist, Address, Decoder)))
2307     return MCDisassembler::Fail;
2308 
2309   return S;
2310 }
2311 
2312 // Check for UNPREDICTABLE predicated ESB instruction
2313 static DecodeStatus DecodeHINTInstruction(MCInst &Inst, unsigned Insn,
2314                                  uint64_t Address, const void *Decoder) {
2315   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2316   unsigned imm8 = fieldFromInstruction(Insn, 0, 8);
2317   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
2318   const FeatureBitset &FeatureBits = Dis->getSubtargetInfo().getFeatureBits();
2319 
2320   DecodeStatus S = MCDisassembler::Success;
2321 
2322   Inst.addOperand(MCOperand::createImm(imm8));
2323 
2324   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2325     return MCDisassembler::Fail;
2326 
2327   // ESB is unpredictable if pred != AL. Without the RAS extension, it is a NOP,
2328   // so all predicates should be allowed.
2329   if (imm8 == 0x10 && pred != 0xe && ((FeatureBits[ARM::FeatureRAS]) != 0))
2330     S = MCDisassembler::SoftFail;
2331 
2332   return S;
2333 }
2334 
2335 static DecodeStatus DecodeCPSInstruction(MCInst &Inst, unsigned Insn,
2336                                  uint64_t Address, const void *Decoder) {
2337   unsigned imod = fieldFromInstruction(Insn, 18, 2);
2338   unsigned M = fieldFromInstruction(Insn, 17, 1);
2339   unsigned iflags = fieldFromInstruction(Insn, 6, 3);
2340   unsigned mode = fieldFromInstruction(Insn, 0, 5);
2341 
2342   DecodeStatus S = MCDisassembler::Success;
2343 
2344   // This decoder is called from multiple location that do not check
2345   // the full encoding is valid before they do.
2346   if (fieldFromInstruction(Insn, 5, 1) != 0 ||
2347       fieldFromInstruction(Insn, 16, 1) != 0 ||
2348       fieldFromInstruction(Insn, 20, 8) != 0x10)
2349     return MCDisassembler::Fail;
2350 
2351   // imod == '01' --> UNPREDICTABLE
2352   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
2353   // return failure here.  The '01' imod value is unprintable, so there's
2354   // nothing useful we could do even if we returned UNPREDICTABLE.
2355 
2356   if (imod == 1) return MCDisassembler::Fail;
2357 
2358   if (imod && M) {
2359     Inst.setOpcode(ARM::CPS3p);
2360     Inst.addOperand(MCOperand::createImm(imod));
2361     Inst.addOperand(MCOperand::createImm(iflags));
2362     Inst.addOperand(MCOperand::createImm(mode));
2363   } else if (imod && !M) {
2364     Inst.setOpcode(ARM::CPS2p);
2365     Inst.addOperand(MCOperand::createImm(imod));
2366     Inst.addOperand(MCOperand::createImm(iflags));
2367     if (mode) S = MCDisassembler::SoftFail;
2368   } else if (!imod && M) {
2369     Inst.setOpcode(ARM::CPS1p);
2370     Inst.addOperand(MCOperand::createImm(mode));
2371     if (iflags) S = MCDisassembler::SoftFail;
2372   } else {
2373     // imod == '00' && M == '0' --> UNPREDICTABLE
2374     Inst.setOpcode(ARM::CPS1p);
2375     Inst.addOperand(MCOperand::createImm(mode));
2376     S = MCDisassembler::SoftFail;
2377   }
2378 
2379   return S;
2380 }
2381 
2382 static DecodeStatus DecodeT2CPSInstruction(MCInst &Inst, unsigned Insn,
2383                                  uint64_t Address, const void *Decoder) {
2384   unsigned imod = fieldFromInstruction(Insn, 9, 2);
2385   unsigned M = fieldFromInstruction(Insn, 8, 1);
2386   unsigned iflags = fieldFromInstruction(Insn, 5, 3);
2387   unsigned mode = fieldFromInstruction(Insn, 0, 5);
2388 
2389   DecodeStatus S = MCDisassembler::Success;
2390 
2391   // imod == '01' --> UNPREDICTABLE
2392   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
2393   // return failure here.  The '01' imod value is unprintable, so there's
2394   // nothing useful we could do even if we returned UNPREDICTABLE.
2395 
2396   if (imod == 1) return MCDisassembler::Fail;
2397 
2398   if (imod && M) {
2399     Inst.setOpcode(ARM::t2CPS3p);
2400     Inst.addOperand(MCOperand::createImm(imod));
2401     Inst.addOperand(MCOperand::createImm(iflags));
2402     Inst.addOperand(MCOperand::createImm(mode));
2403   } else if (imod && !M) {
2404     Inst.setOpcode(ARM::t2CPS2p);
2405     Inst.addOperand(MCOperand::createImm(imod));
2406     Inst.addOperand(MCOperand::createImm(iflags));
2407     if (mode) S = MCDisassembler::SoftFail;
2408   } else if (!imod && M) {
2409     Inst.setOpcode(ARM::t2CPS1p);
2410     Inst.addOperand(MCOperand::createImm(mode));
2411     if (iflags) S = MCDisassembler::SoftFail;
2412   } else {
2413     // imod == '00' && M == '0' --> this is a HINT instruction
2414     int imm = fieldFromInstruction(Insn, 0, 8);
2415     // HINT are defined only for immediate in [0..4]
2416     if(imm > 4) return MCDisassembler::Fail;
2417     Inst.setOpcode(ARM::t2HINT);
2418     Inst.addOperand(MCOperand::createImm(imm));
2419   }
2420 
2421   return S;
2422 }
2423 
2424 static DecodeStatus DecodeT2MOVTWInstruction(MCInst &Inst, unsigned Insn,
2425                                  uint64_t Address, const void *Decoder) {
2426   DecodeStatus S = MCDisassembler::Success;
2427 
2428   unsigned Rd = fieldFromInstruction(Insn, 8, 4);
2429   unsigned imm = 0;
2430 
2431   imm |= (fieldFromInstruction(Insn, 0, 8) << 0);
2432   imm |= (fieldFromInstruction(Insn, 12, 3) << 8);
2433   imm |= (fieldFromInstruction(Insn, 16, 4) << 12);
2434   imm |= (fieldFromInstruction(Insn, 26, 1) << 11);
2435 
2436   if (Inst.getOpcode() == ARM::t2MOVTi16)
2437     if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
2438       return MCDisassembler::Fail;
2439   if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
2440     return MCDisassembler::Fail;
2441 
2442   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
2443     Inst.addOperand(MCOperand::createImm(imm));
2444 
2445   return S;
2446 }
2447 
2448 static DecodeStatus DecodeArmMOVTWInstruction(MCInst &Inst, unsigned Insn,
2449                                  uint64_t Address, const void *Decoder) {
2450   DecodeStatus S = MCDisassembler::Success;
2451 
2452   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2453   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2454   unsigned imm = 0;
2455 
2456   imm |= (fieldFromInstruction(Insn, 0, 12) << 0);
2457   imm |= (fieldFromInstruction(Insn, 16, 4) << 12);
2458 
2459   if (Inst.getOpcode() == ARM::MOVTi16)
2460     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2461       return MCDisassembler::Fail;
2462 
2463   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2464     return MCDisassembler::Fail;
2465 
2466   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
2467     Inst.addOperand(MCOperand::createImm(imm));
2468 
2469   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2470     return MCDisassembler::Fail;
2471 
2472   return S;
2473 }
2474 
2475 static DecodeStatus DecodeSMLAInstruction(MCInst &Inst, unsigned Insn,
2476                                  uint64_t Address, const void *Decoder) {
2477   DecodeStatus S = MCDisassembler::Success;
2478 
2479   unsigned Rd = fieldFromInstruction(Insn, 16, 4);
2480   unsigned Rn = fieldFromInstruction(Insn, 0, 4);
2481   unsigned Rm = fieldFromInstruction(Insn, 8, 4);
2482   unsigned Ra = fieldFromInstruction(Insn, 12, 4);
2483   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2484 
2485   if (pred == 0xF)
2486     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
2487 
2488   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2489     return MCDisassembler::Fail;
2490   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
2491     return MCDisassembler::Fail;
2492   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
2493     return MCDisassembler::Fail;
2494   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Ra, Address, Decoder)))
2495     return MCDisassembler::Fail;
2496 
2497   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2498     return MCDisassembler::Fail;
2499 
2500   return S;
2501 }
2502 
2503 static DecodeStatus DecodeTSTInstruction(MCInst &Inst, unsigned Insn,
2504                                   uint64_t Address, const void *Decoder) {
2505   DecodeStatus S = MCDisassembler::Success;
2506 
2507   unsigned Pred = fieldFromInstruction(Insn, 28, 4);
2508   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2509   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2510 
2511   if (Pred == 0xF)
2512     return DecodeSETPANInstruction(Inst, Insn, Address, Decoder);
2513 
2514   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2515     return MCDisassembler::Fail;
2516   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2517     return MCDisassembler::Fail;
2518   if (!Check(S, DecodePredicateOperand(Inst, Pred, Address, Decoder)))
2519     return MCDisassembler::Fail;
2520 
2521   return S;
2522 }
2523 
2524 static DecodeStatus DecodeSETPANInstruction(MCInst &Inst, unsigned Insn,
2525                                   uint64_t Address, const void *Decoder) {
2526   DecodeStatus S = MCDisassembler::Success;
2527 
2528   unsigned Imm = fieldFromInstruction(Insn, 9, 1);
2529 
2530   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
2531   const FeatureBitset &FeatureBits = Dis->getSubtargetInfo().getFeatureBits();
2532 
2533   if (!FeatureBits[ARM::HasV8_1aOps] ||
2534       !FeatureBits[ARM::HasV8Ops])
2535     return MCDisassembler::Fail;
2536 
2537   // Decoder can be called from DecodeTST, which does not check the full
2538   // encoding is valid.
2539   if (fieldFromInstruction(Insn, 20,12) != 0xf11 ||
2540       fieldFromInstruction(Insn, 4,4) != 0)
2541     return MCDisassembler::Fail;
2542   if (fieldFromInstruction(Insn, 10,10) != 0 ||
2543       fieldFromInstruction(Insn, 0,4) != 0)
2544     S = MCDisassembler::SoftFail;
2545 
2546   Inst.setOpcode(ARM::SETPAN);
2547   Inst.addOperand(MCOperand::createImm(Imm));
2548 
2549   return S;
2550 }
2551 
2552 static DecodeStatus DecodeAddrModeImm12Operand(MCInst &Inst, unsigned Val,
2553                            uint64_t Address, const void *Decoder) {
2554   DecodeStatus S = MCDisassembler::Success;
2555 
2556   unsigned add = fieldFromInstruction(Val, 12, 1);
2557   unsigned imm = fieldFromInstruction(Val, 0, 12);
2558   unsigned Rn = fieldFromInstruction(Val, 13, 4);
2559 
2560   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2561     return MCDisassembler::Fail;
2562 
2563   if (!add) imm *= -1;
2564   if (imm == 0 && !add) imm = INT32_MIN;
2565   Inst.addOperand(MCOperand::createImm(imm));
2566   if (Rn == 15)
2567     tryAddingPcLoadReferenceComment(Address, Address + imm + 8, Decoder);
2568 
2569   return S;
2570 }
2571 
2572 static DecodeStatus DecodeAddrMode5Operand(MCInst &Inst, unsigned Val,
2573                                    uint64_t Address, const void *Decoder) {
2574   DecodeStatus S = MCDisassembler::Success;
2575 
2576   unsigned Rn = fieldFromInstruction(Val, 9, 4);
2577   // U == 1 to add imm, 0 to subtract it.
2578   unsigned U = fieldFromInstruction(Val, 8, 1);
2579   unsigned imm = fieldFromInstruction(Val, 0, 8);
2580 
2581   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2582     return MCDisassembler::Fail;
2583 
2584   if (U)
2585     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5Opc(ARM_AM::add, imm)));
2586   else
2587     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5Opc(ARM_AM::sub, imm)));
2588 
2589   return S;
2590 }
2591 
2592 static DecodeStatus DecodeAddrMode5FP16Operand(MCInst &Inst, unsigned Val,
2593                                    uint64_t Address, const void *Decoder) {
2594   DecodeStatus S = MCDisassembler::Success;
2595 
2596   unsigned Rn = fieldFromInstruction(Val, 9, 4);
2597   // U == 1 to add imm, 0 to subtract it.
2598   unsigned U = fieldFromInstruction(Val, 8, 1);
2599   unsigned imm = fieldFromInstruction(Val, 0, 8);
2600 
2601   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2602     return MCDisassembler::Fail;
2603 
2604   if (U)
2605     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5FP16Opc(ARM_AM::add, imm)));
2606   else
2607     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5FP16Opc(ARM_AM::sub, imm)));
2608 
2609   return S;
2610 }
2611 
2612 static DecodeStatus DecodeAddrMode7Operand(MCInst &Inst, unsigned Val,
2613                                    uint64_t Address, const void *Decoder) {
2614   return DecodeGPRRegisterClass(Inst, Val, Address, Decoder);
2615 }
2616 
2617 static DecodeStatus
2618 DecodeT2BInstruction(MCInst &Inst, unsigned Insn,
2619                      uint64_t Address, const void *Decoder) {
2620   DecodeStatus Status = MCDisassembler::Success;
2621 
2622   // Note the J1 and J2 values are from the encoded instruction.  So here
2623   // change them to I1 and I2 values via as documented:
2624   // I1 = NOT(J1 EOR S);
2625   // I2 = NOT(J2 EOR S);
2626   // and build the imm32 with one trailing zero as documented:
2627   // imm32 = SignExtend(S:I1:I2:imm10:imm11:'0', 32);
2628   unsigned S = fieldFromInstruction(Insn, 26, 1);
2629   unsigned J1 = fieldFromInstruction(Insn, 13, 1);
2630   unsigned J2 = fieldFromInstruction(Insn, 11, 1);
2631   unsigned I1 = !(J1 ^ S);
2632   unsigned I2 = !(J2 ^ S);
2633   unsigned imm10 = fieldFromInstruction(Insn, 16, 10);
2634   unsigned imm11 = fieldFromInstruction(Insn, 0, 11);
2635   unsigned tmp = (S << 23) | (I1 << 22) | (I2 << 21) | (imm10 << 11) | imm11;
2636   int imm32 = SignExtend32<25>(tmp << 1);
2637   if (!tryAddingSymbolicOperand(Address, Address + imm32 + 4,
2638                                 true, 4, Inst, Decoder))
2639     Inst.addOperand(MCOperand::createImm(imm32));
2640 
2641   return Status;
2642 }
2643 
2644 static DecodeStatus
2645 DecodeBranchImmInstruction(MCInst &Inst, unsigned Insn,
2646                            uint64_t Address, const void *Decoder) {
2647   DecodeStatus S = MCDisassembler::Success;
2648 
2649   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2650   unsigned imm = fieldFromInstruction(Insn, 0, 24) << 2;
2651 
2652   if (pred == 0xF) {
2653     Inst.setOpcode(ARM::BLXi);
2654     imm |= fieldFromInstruction(Insn, 24, 1) << 1;
2655     if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<26>(imm) + 8,
2656                                   true, 4, Inst, Decoder))
2657     Inst.addOperand(MCOperand::createImm(SignExtend32<26>(imm)));
2658     return S;
2659   }
2660 
2661   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<26>(imm) + 8,
2662                                 true, 4, Inst, Decoder))
2663     Inst.addOperand(MCOperand::createImm(SignExtend32<26>(imm)));
2664   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2665     return MCDisassembler::Fail;
2666 
2667   return S;
2668 }
2669 
2670 static DecodeStatus DecodeAddrMode6Operand(MCInst &Inst, unsigned Val,
2671                                    uint64_t Address, const void *Decoder) {
2672   DecodeStatus S = MCDisassembler::Success;
2673 
2674   unsigned Rm = fieldFromInstruction(Val, 0, 4);
2675   unsigned align = fieldFromInstruction(Val, 4, 2);
2676 
2677   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2678     return MCDisassembler::Fail;
2679   if (!align)
2680     Inst.addOperand(MCOperand::createImm(0));
2681   else
2682     Inst.addOperand(MCOperand::createImm(4 << align));
2683 
2684   return S;
2685 }
2686 
2687 static DecodeStatus DecodeVLDInstruction(MCInst &Inst, unsigned Insn,
2688                                    uint64_t Address, const void *Decoder) {
2689   DecodeStatus S = MCDisassembler::Success;
2690 
2691   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2692   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
2693   unsigned wb = fieldFromInstruction(Insn, 16, 4);
2694   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2695   Rn |= fieldFromInstruction(Insn, 4, 2) << 4;
2696   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2697 
2698   // First output register
2699   switch (Inst.getOpcode()) {
2700   case ARM::VLD1q16: case ARM::VLD1q32: case ARM::VLD1q64: case ARM::VLD1q8:
2701   case ARM::VLD1q16wb_fixed: case ARM::VLD1q16wb_register:
2702   case ARM::VLD1q32wb_fixed: case ARM::VLD1q32wb_register:
2703   case ARM::VLD1q64wb_fixed: case ARM::VLD1q64wb_register:
2704   case ARM::VLD1q8wb_fixed: case ARM::VLD1q8wb_register:
2705   case ARM::VLD2d16: case ARM::VLD2d32: case ARM::VLD2d8:
2706   case ARM::VLD2d16wb_fixed: case ARM::VLD2d16wb_register:
2707   case ARM::VLD2d32wb_fixed: case ARM::VLD2d32wb_register:
2708   case ARM::VLD2d8wb_fixed: case ARM::VLD2d8wb_register:
2709     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
2710       return MCDisassembler::Fail;
2711     break;
2712   case ARM::VLD2b16:
2713   case ARM::VLD2b32:
2714   case ARM::VLD2b8:
2715   case ARM::VLD2b16wb_fixed:
2716   case ARM::VLD2b16wb_register:
2717   case ARM::VLD2b32wb_fixed:
2718   case ARM::VLD2b32wb_register:
2719   case ARM::VLD2b8wb_fixed:
2720   case ARM::VLD2b8wb_register:
2721     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
2722       return MCDisassembler::Fail;
2723     break;
2724   default:
2725     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2726       return MCDisassembler::Fail;
2727   }
2728 
2729   // Second output register
2730   switch (Inst.getOpcode()) {
2731     case ARM::VLD3d8:
2732     case ARM::VLD3d16:
2733     case ARM::VLD3d32:
2734     case ARM::VLD3d8_UPD:
2735     case ARM::VLD3d16_UPD:
2736     case ARM::VLD3d32_UPD:
2737     case ARM::VLD4d8:
2738     case ARM::VLD4d16:
2739     case ARM::VLD4d32:
2740     case ARM::VLD4d8_UPD:
2741     case ARM::VLD4d16_UPD:
2742     case ARM::VLD4d32_UPD:
2743       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
2744         return MCDisassembler::Fail;
2745       break;
2746     case ARM::VLD3q8:
2747     case ARM::VLD3q16:
2748     case ARM::VLD3q32:
2749     case ARM::VLD3q8_UPD:
2750     case ARM::VLD3q16_UPD:
2751     case ARM::VLD3q32_UPD:
2752     case ARM::VLD4q8:
2753     case ARM::VLD4q16:
2754     case ARM::VLD4q32:
2755     case ARM::VLD4q8_UPD:
2756     case ARM::VLD4q16_UPD:
2757     case ARM::VLD4q32_UPD:
2758       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2759         return MCDisassembler::Fail;
2760       break;
2761     default:
2762       break;
2763   }
2764 
2765   // Third output register
2766   switch(Inst.getOpcode()) {
2767     case ARM::VLD3d8:
2768     case ARM::VLD3d16:
2769     case ARM::VLD3d32:
2770     case ARM::VLD3d8_UPD:
2771     case ARM::VLD3d16_UPD:
2772     case ARM::VLD3d32_UPD:
2773     case ARM::VLD4d8:
2774     case ARM::VLD4d16:
2775     case ARM::VLD4d32:
2776     case ARM::VLD4d8_UPD:
2777     case ARM::VLD4d16_UPD:
2778     case ARM::VLD4d32_UPD:
2779       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2780         return MCDisassembler::Fail;
2781       break;
2782     case ARM::VLD3q8:
2783     case ARM::VLD3q16:
2784     case ARM::VLD3q32:
2785     case ARM::VLD3q8_UPD:
2786     case ARM::VLD3q16_UPD:
2787     case ARM::VLD3q32_UPD:
2788     case ARM::VLD4q8:
2789     case ARM::VLD4q16:
2790     case ARM::VLD4q32:
2791     case ARM::VLD4q8_UPD:
2792     case ARM::VLD4q16_UPD:
2793     case ARM::VLD4q32_UPD:
2794       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
2795         return MCDisassembler::Fail;
2796       break;
2797     default:
2798       break;
2799   }
2800 
2801   // Fourth output register
2802   switch (Inst.getOpcode()) {
2803     case ARM::VLD4d8:
2804     case ARM::VLD4d16:
2805     case ARM::VLD4d32:
2806     case ARM::VLD4d8_UPD:
2807     case ARM::VLD4d16_UPD:
2808     case ARM::VLD4d32_UPD:
2809       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
2810         return MCDisassembler::Fail;
2811       break;
2812     case ARM::VLD4q8:
2813     case ARM::VLD4q16:
2814     case ARM::VLD4q32:
2815     case ARM::VLD4q8_UPD:
2816     case ARM::VLD4q16_UPD:
2817     case ARM::VLD4q32_UPD:
2818       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
2819         return MCDisassembler::Fail;
2820       break;
2821     default:
2822       break;
2823   }
2824 
2825   // Writeback operand
2826   switch (Inst.getOpcode()) {
2827     case ARM::VLD1d8wb_fixed:
2828     case ARM::VLD1d16wb_fixed:
2829     case ARM::VLD1d32wb_fixed:
2830     case ARM::VLD1d64wb_fixed:
2831     case ARM::VLD1d8wb_register:
2832     case ARM::VLD1d16wb_register:
2833     case ARM::VLD1d32wb_register:
2834     case ARM::VLD1d64wb_register:
2835     case ARM::VLD1q8wb_fixed:
2836     case ARM::VLD1q16wb_fixed:
2837     case ARM::VLD1q32wb_fixed:
2838     case ARM::VLD1q64wb_fixed:
2839     case ARM::VLD1q8wb_register:
2840     case ARM::VLD1q16wb_register:
2841     case ARM::VLD1q32wb_register:
2842     case ARM::VLD1q64wb_register:
2843     case ARM::VLD1d8Twb_fixed:
2844     case ARM::VLD1d8Twb_register:
2845     case ARM::VLD1d16Twb_fixed:
2846     case ARM::VLD1d16Twb_register:
2847     case ARM::VLD1d32Twb_fixed:
2848     case ARM::VLD1d32Twb_register:
2849     case ARM::VLD1d64Twb_fixed:
2850     case ARM::VLD1d64Twb_register:
2851     case ARM::VLD1d8Qwb_fixed:
2852     case ARM::VLD1d8Qwb_register:
2853     case ARM::VLD1d16Qwb_fixed:
2854     case ARM::VLD1d16Qwb_register:
2855     case ARM::VLD1d32Qwb_fixed:
2856     case ARM::VLD1d32Qwb_register:
2857     case ARM::VLD1d64Qwb_fixed:
2858     case ARM::VLD1d64Qwb_register:
2859     case ARM::VLD2d8wb_fixed:
2860     case ARM::VLD2d16wb_fixed:
2861     case ARM::VLD2d32wb_fixed:
2862     case ARM::VLD2q8wb_fixed:
2863     case ARM::VLD2q16wb_fixed:
2864     case ARM::VLD2q32wb_fixed:
2865     case ARM::VLD2d8wb_register:
2866     case ARM::VLD2d16wb_register:
2867     case ARM::VLD2d32wb_register:
2868     case ARM::VLD2q8wb_register:
2869     case ARM::VLD2q16wb_register:
2870     case ARM::VLD2q32wb_register:
2871     case ARM::VLD2b8wb_fixed:
2872     case ARM::VLD2b16wb_fixed:
2873     case ARM::VLD2b32wb_fixed:
2874     case ARM::VLD2b8wb_register:
2875     case ARM::VLD2b16wb_register:
2876     case ARM::VLD2b32wb_register:
2877       Inst.addOperand(MCOperand::createImm(0));
2878       break;
2879     case ARM::VLD3d8_UPD:
2880     case ARM::VLD3d16_UPD:
2881     case ARM::VLD3d32_UPD:
2882     case ARM::VLD3q8_UPD:
2883     case ARM::VLD3q16_UPD:
2884     case ARM::VLD3q32_UPD:
2885     case ARM::VLD4d8_UPD:
2886     case ARM::VLD4d16_UPD:
2887     case ARM::VLD4d32_UPD:
2888     case ARM::VLD4q8_UPD:
2889     case ARM::VLD4q16_UPD:
2890     case ARM::VLD4q32_UPD:
2891       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
2892         return MCDisassembler::Fail;
2893       break;
2894     default:
2895       break;
2896   }
2897 
2898   // AddrMode6 Base (register+alignment)
2899   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
2900     return MCDisassembler::Fail;
2901 
2902   // AddrMode6 Offset (register)
2903   switch (Inst.getOpcode()) {
2904   default:
2905     // The below have been updated to have explicit am6offset split
2906     // between fixed and register offset. For those instructions not
2907     // yet updated, we need to add an additional reg0 operand for the
2908     // fixed variant.
2909     //
2910     // The fixed offset encodes as Rm == 0xd, so we check for that.
2911     if (Rm == 0xd) {
2912       Inst.addOperand(MCOperand::createReg(0));
2913       break;
2914     }
2915     // Fall through to handle the register offset variant.
2916     LLVM_FALLTHROUGH;
2917   case ARM::VLD1d8wb_fixed:
2918   case ARM::VLD1d16wb_fixed:
2919   case ARM::VLD1d32wb_fixed:
2920   case ARM::VLD1d64wb_fixed:
2921   case ARM::VLD1d8Twb_fixed:
2922   case ARM::VLD1d16Twb_fixed:
2923   case ARM::VLD1d32Twb_fixed:
2924   case ARM::VLD1d64Twb_fixed:
2925   case ARM::VLD1d8Qwb_fixed:
2926   case ARM::VLD1d16Qwb_fixed:
2927   case ARM::VLD1d32Qwb_fixed:
2928   case ARM::VLD1d64Qwb_fixed:
2929   case ARM::VLD1d8wb_register:
2930   case ARM::VLD1d16wb_register:
2931   case ARM::VLD1d32wb_register:
2932   case ARM::VLD1d64wb_register:
2933   case ARM::VLD1q8wb_fixed:
2934   case ARM::VLD1q16wb_fixed:
2935   case ARM::VLD1q32wb_fixed:
2936   case ARM::VLD1q64wb_fixed:
2937   case ARM::VLD1q8wb_register:
2938   case ARM::VLD1q16wb_register:
2939   case ARM::VLD1q32wb_register:
2940   case ARM::VLD1q64wb_register:
2941     // The fixed offset post-increment encodes Rm == 0xd. The no-writeback
2942     // variant encodes Rm == 0xf. Anything else is a register offset post-
2943     // increment and we need to add the register operand to the instruction.
2944     if (Rm != 0xD && Rm != 0xF &&
2945         !Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2946       return MCDisassembler::Fail;
2947     break;
2948   case ARM::VLD2d8wb_fixed:
2949   case ARM::VLD2d16wb_fixed:
2950   case ARM::VLD2d32wb_fixed:
2951   case ARM::VLD2b8wb_fixed:
2952   case ARM::VLD2b16wb_fixed:
2953   case ARM::VLD2b32wb_fixed:
2954   case ARM::VLD2q8wb_fixed:
2955   case ARM::VLD2q16wb_fixed:
2956   case ARM::VLD2q32wb_fixed:
2957     break;
2958   }
2959 
2960   return S;
2961 }
2962 
2963 static DecodeStatus DecodeVLDST1Instruction(MCInst &Inst, unsigned Insn,
2964                                    uint64_t Address, const void *Decoder) {
2965   unsigned type = fieldFromInstruction(Insn, 8, 4);
2966   unsigned align = fieldFromInstruction(Insn, 4, 2);
2967   if (type == 6 && (align & 2)) return MCDisassembler::Fail;
2968   if (type == 7 && (align & 2)) return MCDisassembler::Fail;
2969   if (type == 10 && align == 3) return MCDisassembler::Fail;
2970 
2971   unsigned load = fieldFromInstruction(Insn, 21, 1);
2972   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2973               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2974 }
2975 
2976 static DecodeStatus DecodeVLDST2Instruction(MCInst &Inst, unsigned Insn,
2977                                    uint64_t Address, const void *Decoder) {
2978   unsigned size = fieldFromInstruction(Insn, 6, 2);
2979   if (size == 3) return MCDisassembler::Fail;
2980 
2981   unsigned type = fieldFromInstruction(Insn, 8, 4);
2982   unsigned align = fieldFromInstruction(Insn, 4, 2);
2983   if (type == 8 && align == 3) return MCDisassembler::Fail;
2984   if (type == 9 && align == 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 DecodeVLDST3Instruction(MCInst &Inst, unsigned Insn,
2992                                    uint64_t Address, const void *Decoder) {
2993   unsigned size = fieldFromInstruction(Insn, 6, 2);
2994   if (size == 3) return MCDisassembler::Fail;
2995 
2996   unsigned align = fieldFromInstruction(Insn, 4, 2);
2997   if (align & 2) return MCDisassembler::Fail;
2998 
2999   unsigned load = fieldFromInstruction(Insn, 21, 1);
3000   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
3001               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
3002 }
3003 
3004 static DecodeStatus DecodeVLDST4Instruction(MCInst &Inst, unsigned Insn,
3005                                    uint64_t Address, const void *Decoder) {
3006   unsigned size = fieldFromInstruction(Insn, 6, 2);
3007   if (size == 3) return MCDisassembler::Fail;
3008 
3009   unsigned load = fieldFromInstruction(Insn, 21, 1);
3010   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
3011               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
3012 }
3013 
3014 static DecodeStatus DecodeVSTInstruction(MCInst &Inst, unsigned Insn,
3015                                  uint64_t Address, const void *Decoder) {
3016   DecodeStatus S = MCDisassembler::Success;
3017 
3018   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3019   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3020   unsigned wb = fieldFromInstruction(Insn, 16, 4);
3021   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3022   Rn |= fieldFromInstruction(Insn, 4, 2) << 4;
3023   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3024 
3025   // Writeback Operand
3026   switch (Inst.getOpcode()) {
3027     case ARM::VST1d8wb_fixed:
3028     case ARM::VST1d16wb_fixed:
3029     case ARM::VST1d32wb_fixed:
3030     case ARM::VST1d64wb_fixed:
3031     case ARM::VST1d8wb_register:
3032     case ARM::VST1d16wb_register:
3033     case ARM::VST1d32wb_register:
3034     case ARM::VST1d64wb_register:
3035     case ARM::VST1q8wb_fixed:
3036     case ARM::VST1q16wb_fixed:
3037     case ARM::VST1q32wb_fixed:
3038     case ARM::VST1q64wb_fixed:
3039     case ARM::VST1q8wb_register:
3040     case ARM::VST1q16wb_register:
3041     case ARM::VST1q32wb_register:
3042     case ARM::VST1q64wb_register:
3043     case ARM::VST1d8Twb_fixed:
3044     case ARM::VST1d16Twb_fixed:
3045     case ARM::VST1d32Twb_fixed:
3046     case ARM::VST1d64Twb_fixed:
3047     case ARM::VST1d8Twb_register:
3048     case ARM::VST1d16Twb_register:
3049     case ARM::VST1d32Twb_register:
3050     case ARM::VST1d64Twb_register:
3051     case ARM::VST1d8Qwb_fixed:
3052     case ARM::VST1d16Qwb_fixed:
3053     case ARM::VST1d32Qwb_fixed:
3054     case ARM::VST1d64Qwb_fixed:
3055     case ARM::VST1d8Qwb_register:
3056     case ARM::VST1d16Qwb_register:
3057     case ARM::VST1d32Qwb_register:
3058     case ARM::VST1d64Qwb_register:
3059     case ARM::VST2d8wb_fixed:
3060     case ARM::VST2d16wb_fixed:
3061     case ARM::VST2d32wb_fixed:
3062     case ARM::VST2d8wb_register:
3063     case ARM::VST2d16wb_register:
3064     case ARM::VST2d32wb_register:
3065     case ARM::VST2q8wb_fixed:
3066     case ARM::VST2q16wb_fixed:
3067     case ARM::VST2q32wb_fixed:
3068     case ARM::VST2q8wb_register:
3069     case ARM::VST2q16wb_register:
3070     case ARM::VST2q32wb_register:
3071     case ARM::VST2b8wb_fixed:
3072     case ARM::VST2b16wb_fixed:
3073     case ARM::VST2b32wb_fixed:
3074     case ARM::VST2b8wb_register:
3075     case ARM::VST2b16wb_register:
3076     case ARM::VST2b32wb_register:
3077       if (Rm == 0xF)
3078         return MCDisassembler::Fail;
3079       Inst.addOperand(MCOperand::createImm(0));
3080       break;
3081     case ARM::VST3d8_UPD:
3082     case ARM::VST3d16_UPD:
3083     case ARM::VST3d32_UPD:
3084     case ARM::VST3q8_UPD:
3085     case ARM::VST3q16_UPD:
3086     case ARM::VST3q32_UPD:
3087     case ARM::VST4d8_UPD:
3088     case ARM::VST4d16_UPD:
3089     case ARM::VST4d32_UPD:
3090     case ARM::VST4q8_UPD:
3091     case ARM::VST4q16_UPD:
3092     case ARM::VST4q32_UPD:
3093       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
3094         return MCDisassembler::Fail;
3095       break;
3096     default:
3097       break;
3098   }
3099 
3100   // AddrMode6 Base (register+alignment)
3101   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
3102     return MCDisassembler::Fail;
3103 
3104   // AddrMode6 Offset (register)
3105   switch (Inst.getOpcode()) {
3106     default:
3107       if (Rm == 0xD)
3108         Inst.addOperand(MCOperand::createReg(0));
3109       else if (Rm != 0xF) {
3110         if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3111           return MCDisassembler::Fail;
3112       }
3113       break;
3114     case ARM::VST1d8wb_fixed:
3115     case ARM::VST1d16wb_fixed:
3116     case ARM::VST1d32wb_fixed:
3117     case ARM::VST1d64wb_fixed:
3118     case ARM::VST1q8wb_fixed:
3119     case ARM::VST1q16wb_fixed:
3120     case ARM::VST1q32wb_fixed:
3121     case ARM::VST1q64wb_fixed:
3122     case ARM::VST1d8Twb_fixed:
3123     case ARM::VST1d16Twb_fixed:
3124     case ARM::VST1d32Twb_fixed:
3125     case ARM::VST1d64Twb_fixed:
3126     case ARM::VST1d8Qwb_fixed:
3127     case ARM::VST1d16Qwb_fixed:
3128     case ARM::VST1d32Qwb_fixed:
3129     case ARM::VST1d64Qwb_fixed:
3130     case ARM::VST2d8wb_fixed:
3131     case ARM::VST2d16wb_fixed:
3132     case ARM::VST2d32wb_fixed:
3133     case ARM::VST2q8wb_fixed:
3134     case ARM::VST2q16wb_fixed:
3135     case ARM::VST2q32wb_fixed:
3136     case ARM::VST2b8wb_fixed:
3137     case ARM::VST2b16wb_fixed:
3138     case ARM::VST2b32wb_fixed:
3139       break;
3140   }
3141 
3142   // First input register
3143   switch (Inst.getOpcode()) {
3144   case ARM::VST1q16:
3145   case ARM::VST1q32:
3146   case ARM::VST1q64:
3147   case ARM::VST1q8:
3148   case ARM::VST1q16wb_fixed:
3149   case ARM::VST1q16wb_register:
3150   case ARM::VST1q32wb_fixed:
3151   case ARM::VST1q32wb_register:
3152   case ARM::VST1q64wb_fixed:
3153   case ARM::VST1q64wb_register:
3154   case ARM::VST1q8wb_fixed:
3155   case ARM::VST1q8wb_register:
3156   case ARM::VST2d16:
3157   case ARM::VST2d32:
3158   case ARM::VST2d8:
3159   case ARM::VST2d16wb_fixed:
3160   case ARM::VST2d16wb_register:
3161   case ARM::VST2d32wb_fixed:
3162   case ARM::VST2d32wb_register:
3163   case ARM::VST2d8wb_fixed:
3164   case ARM::VST2d8wb_register:
3165     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3166       return MCDisassembler::Fail;
3167     break;
3168   case ARM::VST2b16:
3169   case ARM::VST2b32:
3170   case ARM::VST2b8:
3171   case ARM::VST2b16wb_fixed:
3172   case ARM::VST2b16wb_register:
3173   case ARM::VST2b32wb_fixed:
3174   case ARM::VST2b32wb_register:
3175   case ARM::VST2b8wb_fixed:
3176   case ARM::VST2b8wb_register:
3177     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
3178       return MCDisassembler::Fail;
3179     break;
3180   default:
3181     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3182       return MCDisassembler::Fail;
3183   }
3184 
3185   // Second input register
3186   switch (Inst.getOpcode()) {
3187     case ARM::VST3d8:
3188     case ARM::VST3d16:
3189     case ARM::VST3d32:
3190     case ARM::VST3d8_UPD:
3191     case ARM::VST3d16_UPD:
3192     case ARM::VST3d32_UPD:
3193     case ARM::VST4d8:
3194     case ARM::VST4d16:
3195     case ARM::VST4d32:
3196     case ARM::VST4d8_UPD:
3197     case ARM::VST4d16_UPD:
3198     case ARM::VST4d32_UPD:
3199       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
3200         return MCDisassembler::Fail;
3201       break;
3202     case ARM::VST3q8:
3203     case ARM::VST3q16:
3204     case ARM::VST3q32:
3205     case ARM::VST3q8_UPD:
3206     case ARM::VST3q16_UPD:
3207     case ARM::VST3q32_UPD:
3208     case ARM::VST4q8:
3209     case ARM::VST4q16:
3210     case ARM::VST4q32:
3211     case ARM::VST4q8_UPD:
3212     case ARM::VST4q16_UPD:
3213     case ARM::VST4q32_UPD:
3214       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
3215         return MCDisassembler::Fail;
3216       break;
3217     default:
3218       break;
3219   }
3220 
3221   // Third input register
3222   switch (Inst.getOpcode()) {
3223     case ARM::VST3d8:
3224     case ARM::VST3d16:
3225     case ARM::VST3d32:
3226     case ARM::VST3d8_UPD:
3227     case ARM::VST3d16_UPD:
3228     case ARM::VST3d32_UPD:
3229     case ARM::VST4d8:
3230     case ARM::VST4d16:
3231     case ARM::VST4d32:
3232     case ARM::VST4d8_UPD:
3233     case ARM::VST4d16_UPD:
3234     case ARM::VST4d32_UPD:
3235       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
3236         return MCDisassembler::Fail;
3237       break;
3238     case ARM::VST3q8:
3239     case ARM::VST3q16:
3240     case ARM::VST3q32:
3241     case ARM::VST3q8_UPD:
3242     case ARM::VST3q16_UPD:
3243     case ARM::VST3q32_UPD:
3244     case ARM::VST4q8:
3245     case ARM::VST4q16:
3246     case ARM::VST4q32:
3247     case ARM::VST4q8_UPD:
3248     case ARM::VST4q16_UPD:
3249     case ARM::VST4q32_UPD:
3250       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
3251         return MCDisassembler::Fail;
3252       break;
3253     default:
3254       break;
3255   }
3256 
3257   // Fourth input register
3258   switch (Inst.getOpcode()) {
3259     case ARM::VST4d8:
3260     case ARM::VST4d16:
3261     case ARM::VST4d32:
3262     case ARM::VST4d8_UPD:
3263     case ARM::VST4d16_UPD:
3264     case ARM::VST4d32_UPD:
3265       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
3266         return MCDisassembler::Fail;
3267       break;
3268     case ARM::VST4q8:
3269     case ARM::VST4q16:
3270     case ARM::VST4q32:
3271     case ARM::VST4q8_UPD:
3272     case ARM::VST4q16_UPD:
3273     case ARM::VST4q32_UPD:
3274       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
3275         return MCDisassembler::Fail;
3276       break;
3277     default:
3278       break;
3279   }
3280 
3281   return S;
3282 }
3283 
3284 static DecodeStatus DecodeVLD1DupInstruction(MCInst &Inst, unsigned Insn,
3285                                     uint64_t Address, const void *Decoder) {
3286   DecodeStatus S = MCDisassembler::Success;
3287 
3288   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3289   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3290   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3291   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3292   unsigned align = fieldFromInstruction(Insn, 4, 1);
3293   unsigned size = fieldFromInstruction(Insn, 6, 2);
3294 
3295   if (size == 0 && align == 1)
3296     return MCDisassembler::Fail;
3297   align *= (1 << size);
3298 
3299   switch (Inst.getOpcode()) {
3300   case ARM::VLD1DUPq16: case ARM::VLD1DUPq32: case ARM::VLD1DUPq8:
3301   case ARM::VLD1DUPq16wb_fixed: case ARM::VLD1DUPq16wb_register:
3302   case ARM::VLD1DUPq32wb_fixed: case ARM::VLD1DUPq32wb_register:
3303   case ARM::VLD1DUPq8wb_fixed: case ARM::VLD1DUPq8wb_register:
3304     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3305       return MCDisassembler::Fail;
3306     break;
3307   default:
3308     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3309       return MCDisassembler::Fail;
3310     break;
3311   }
3312   if (Rm != 0xF) {
3313     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3314       return MCDisassembler::Fail;
3315   }
3316 
3317   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3318     return MCDisassembler::Fail;
3319   Inst.addOperand(MCOperand::createImm(align));
3320 
3321   // The fixed offset post-increment encodes Rm == 0xd. The no-writeback
3322   // variant encodes Rm == 0xf. Anything else is a register offset post-
3323   // increment and we need to add the register operand to the instruction.
3324   if (Rm != 0xD && Rm != 0xF &&
3325       !Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3326     return MCDisassembler::Fail;
3327 
3328   return S;
3329 }
3330 
3331 static DecodeStatus DecodeVLD2DupInstruction(MCInst &Inst, unsigned Insn,
3332                                     uint64_t Address, const void *Decoder) {
3333   DecodeStatus S = MCDisassembler::Success;
3334 
3335   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3336   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3337   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3338   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3339   unsigned align = fieldFromInstruction(Insn, 4, 1);
3340   unsigned size = 1 << fieldFromInstruction(Insn, 6, 2);
3341   align *= 2*size;
3342 
3343   switch (Inst.getOpcode()) {
3344   case ARM::VLD2DUPd16: case ARM::VLD2DUPd32: case ARM::VLD2DUPd8:
3345   case ARM::VLD2DUPd16wb_fixed: case ARM::VLD2DUPd16wb_register:
3346   case ARM::VLD2DUPd32wb_fixed: case ARM::VLD2DUPd32wb_register:
3347   case ARM::VLD2DUPd8wb_fixed: case ARM::VLD2DUPd8wb_register:
3348     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3349       return MCDisassembler::Fail;
3350     break;
3351   case ARM::VLD2DUPd16x2: case ARM::VLD2DUPd32x2: case ARM::VLD2DUPd8x2:
3352   case ARM::VLD2DUPd16x2wb_fixed: case ARM::VLD2DUPd16x2wb_register:
3353   case ARM::VLD2DUPd32x2wb_fixed: case ARM::VLD2DUPd32x2wb_register:
3354   case ARM::VLD2DUPd8x2wb_fixed: case ARM::VLD2DUPd8x2wb_register:
3355     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
3356       return MCDisassembler::Fail;
3357     break;
3358   default:
3359     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3360       return MCDisassembler::Fail;
3361     break;
3362   }
3363 
3364   if (Rm != 0xF)
3365     Inst.addOperand(MCOperand::createImm(0));
3366 
3367   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3368     return MCDisassembler::Fail;
3369   Inst.addOperand(MCOperand::createImm(align));
3370 
3371   if (Rm != 0xD && Rm != 0xF) {
3372     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3373       return MCDisassembler::Fail;
3374   }
3375 
3376   return S;
3377 }
3378 
3379 static DecodeStatus DecodeVLD3DupInstruction(MCInst &Inst, unsigned Insn,
3380                                     uint64_t Address, const void *Decoder) {
3381   DecodeStatus S = MCDisassembler::Success;
3382 
3383   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3384   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3385   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3386   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3387   unsigned inc = fieldFromInstruction(Insn, 5, 1) + 1;
3388 
3389   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3390     return MCDisassembler::Fail;
3391   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
3392     return MCDisassembler::Fail;
3393   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
3394     return MCDisassembler::Fail;
3395   if (Rm != 0xF) {
3396     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3397       return MCDisassembler::Fail;
3398   }
3399 
3400   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3401     return MCDisassembler::Fail;
3402   Inst.addOperand(MCOperand::createImm(0));
3403 
3404   if (Rm == 0xD)
3405     Inst.addOperand(MCOperand::createReg(0));
3406   else if (Rm != 0xF) {
3407     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3408       return MCDisassembler::Fail;
3409   }
3410 
3411   return S;
3412 }
3413 
3414 static DecodeStatus DecodeVLD4DupInstruction(MCInst &Inst, unsigned Insn,
3415                                     uint64_t Address, const void *Decoder) {
3416   DecodeStatus S = MCDisassembler::Success;
3417 
3418   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3419   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3420   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3421   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3422   unsigned size = fieldFromInstruction(Insn, 6, 2);
3423   unsigned inc = fieldFromInstruction(Insn, 5, 1) + 1;
3424   unsigned align = fieldFromInstruction(Insn, 4, 1);
3425 
3426   if (size == 0x3) {
3427     if (align == 0)
3428       return MCDisassembler::Fail;
3429     align = 16;
3430   } else {
3431     if (size == 2) {
3432       align *= 8;
3433     } else {
3434       size = 1 << size;
3435       align *= 4*size;
3436     }
3437   }
3438 
3439   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3440     return MCDisassembler::Fail;
3441   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
3442     return MCDisassembler::Fail;
3443   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
3444     return MCDisassembler::Fail;
3445   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3*inc)%32, Address, Decoder)))
3446     return MCDisassembler::Fail;
3447   if (Rm != 0xF) {
3448     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3449       return MCDisassembler::Fail;
3450   }
3451 
3452   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3453     return MCDisassembler::Fail;
3454   Inst.addOperand(MCOperand::createImm(align));
3455 
3456   if (Rm == 0xD)
3457     Inst.addOperand(MCOperand::createReg(0));
3458   else if (Rm != 0xF) {
3459     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3460       return MCDisassembler::Fail;
3461   }
3462 
3463   return S;
3464 }
3465 
3466 static DecodeStatus
3467 DecodeVMOVModImmInstruction(MCInst &Inst, unsigned Insn,
3468                             uint64_t Address, const void *Decoder) {
3469   DecodeStatus S = MCDisassembler::Success;
3470 
3471   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3472   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3473   unsigned imm = fieldFromInstruction(Insn, 0, 4);
3474   imm |= fieldFromInstruction(Insn, 16, 3) << 4;
3475   imm |= fieldFromInstruction(Insn, 24, 1) << 7;
3476   imm |= fieldFromInstruction(Insn, 8, 4) << 8;
3477   imm |= fieldFromInstruction(Insn, 5, 1) << 12;
3478   unsigned Q = fieldFromInstruction(Insn, 6, 1);
3479 
3480   if (Q) {
3481     if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3482     return MCDisassembler::Fail;
3483   } else {
3484     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3485     return MCDisassembler::Fail;
3486   }
3487 
3488   Inst.addOperand(MCOperand::createImm(imm));
3489 
3490   switch (Inst.getOpcode()) {
3491     case ARM::VORRiv4i16:
3492     case ARM::VORRiv2i32:
3493     case ARM::VBICiv4i16:
3494     case ARM::VBICiv2i32:
3495       if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3496         return MCDisassembler::Fail;
3497       break;
3498     case ARM::VORRiv8i16:
3499     case ARM::VORRiv4i32:
3500     case ARM::VBICiv8i16:
3501     case ARM::VBICiv4i32:
3502       if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3503         return MCDisassembler::Fail;
3504       break;
3505     default:
3506       break;
3507   }
3508 
3509   return S;
3510 }
3511 
3512 static DecodeStatus
3513 DecodeMVEModImmInstruction(MCInst &Inst, unsigned Insn,
3514                            uint64_t Address, const void *Decoder) {
3515   DecodeStatus S = MCDisassembler::Success;
3516 
3517   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
3518                  fieldFromInstruction(Insn, 13, 3));
3519   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
3520   unsigned imm = fieldFromInstruction(Insn, 0, 4);
3521   imm |= fieldFromInstruction(Insn, 16, 3) << 4;
3522   imm |= fieldFromInstruction(Insn, 28, 1) << 7;
3523   imm |= cmode                             << 8;
3524   imm |= fieldFromInstruction(Insn, 5, 1)  << 12;
3525 
3526   if (cmode == 0xF && Inst.getOpcode() == ARM::MVE_VMVNimmi32)
3527     return MCDisassembler::Fail;
3528 
3529   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
3530     return MCDisassembler::Fail;
3531 
3532   Inst.addOperand(MCOperand::createImm(imm));
3533 
3534   Inst.addOperand(MCOperand::createImm(ARMVCC::None));
3535   Inst.addOperand(MCOperand::createReg(0));
3536   Inst.addOperand(MCOperand::createImm(0));
3537 
3538   return S;
3539 }
3540 
3541 static DecodeStatus DecodeMVEVADCInstruction(MCInst &Inst, unsigned Insn,
3542                                uint64_t Address, const void *Decoder) {
3543   DecodeStatus S = MCDisassembler::Success;
3544 
3545   unsigned Qd = fieldFromInstruction(Insn, 13, 3);
3546   Qd |= fieldFromInstruction(Insn, 22, 1) << 3;
3547   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
3548     return MCDisassembler::Fail;
3549   Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
3550 
3551   unsigned Qn = fieldFromInstruction(Insn, 17, 3);
3552   Qn |= fieldFromInstruction(Insn, 7, 1) << 3;
3553   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qn, Address, Decoder)))
3554     return MCDisassembler::Fail;
3555   unsigned Qm = fieldFromInstruction(Insn, 1, 3);
3556   Qm |= fieldFromInstruction(Insn, 5, 1) << 3;
3557   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
3558     return MCDisassembler::Fail;
3559   if (!fieldFromInstruction(Insn, 12, 1)) // I bit clear => need input FPSCR
3560     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
3561   Inst.addOperand(MCOperand::createImm(Qd));
3562 
3563   return S;
3564 }
3565 
3566 static DecodeStatus DecodeVSHLMaxInstruction(MCInst &Inst, unsigned Insn,
3567                                         uint64_t Address, const void *Decoder) {
3568   DecodeStatus S = MCDisassembler::Success;
3569 
3570   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3571   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3572   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3573   Rm |= fieldFromInstruction(Insn, 5, 1) << 4;
3574   unsigned size = fieldFromInstruction(Insn, 18, 2);
3575 
3576   if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3577     return MCDisassembler::Fail;
3578   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
3579     return MCDisassembler::Fail;
3580   Inst.addOperand(MCOperand::createImm(8 << size));
3581 
3582   return S;
3583 }
3584 
3585 static DecodeStatus DecodeShiftRight8Imm(MCInst &Inst, unsigned Val,
3586                                uint64_t Address, const void *Decoder) {
3587   Inst.addOperand(MCOperand::createImm(8 - Val));
3588   return MCDisassembler::Success;
3589 }
3590 
3591 static DecodeStatus DecodeShiftRight16Imm(MCInst &Inst, unsigned Val,
3592                                uint64_t Address, const void *Decoder) {
3593   Inst.addOperand(MCOperand::createImm(16 - Val));
3594   return MCDisassembler::Success;
3595 }
3596 
3597 static DecodeStatus DecodeShiftRight32Imm(MCInst &Inst, unsigned Val,
3598                                uint64_t Address, const void *Decoder) {
3599   Inst.addOperand(MCOperand::createImm(32 - Val));
3600   return MCDisassembler::Success;
3601 }
3602 
3603 static DecodeStatus DecodeShiftRight64Imm(MCInst &Inst, unsigned Val,
3604                                uint64_t Address, const void *Decoder) {
3605   Inst.addOperand(MCOperand::createImm(64 - Val));
3606   return MCDisassembler::Success;
3607 }
3608 
3609 static DecodeStatus DecodeTBLInstruction(MCInst &Inst, unsigned Insn,
3610                                uint64_t Address, const void *Decoder) {
3611   DecodeStatus S = MCDisassembler::Success;
3612 
3613   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3614   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3615   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3616   Rn |= fieldFromInstruction(Insn, 7, 1) << 4;
3617   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3618   Rm |= fieldFromInstruction(Insn, 5, 1) << 4;
3619   unsigned op = fieldFromInstruction(Insn, 6, 1);
3620 
3621   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3622     return MCDisassembler::Fail;
3623   if (op) {
3624     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3625     return MCDisassembler::Fail; // Writeback
3626   }
3627 
3628   switch (Inst.getOpcode()) {
3629   case ARM::VTBL2:
3630   case ARM::VTBX2:
3631     if (!Check(S, DecodeDPairRegisterClass(Inst, Rn, Address, Decoder)))
3632       return MCDisassembler::Fail;
3633     break;
3634   default:
3635     if (!Check(S, DecodeDPRRegisterClass(Inst, Rn, Address, Decoder)))
3636       return MCDisassembler::Fail;
3637   }
3638 
3639   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
3640     return MCDisassembler::Fail;
3641 
3642   return S;
3643 }
3644 
3645 static DecodeStatus DecodeThumbAddSpecialReg(MCInst &Inst, uint16_t Insn,
3646                                      uint64_t Address, const void *Decoder) {
3647   DecodeStatus S = MCDisassembler::Success;
3648 
3649   unsigned dst = fieldFromInstruction(Insn, 8, 3);
3650   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3651 
3652   if (!Check(S, DecodetGPRRegisterClass(Inst, dst, Address, Decoder)))
3653     return MCDisassembler::Fail;
3654 
3655   switch(Inst.getOpcode()) {
3656     default:
3657       return MCDisassembler::Fail;
3658     case ARM::tADR:
3659       break; // tADR does not explicitly represent the PC as an operand.
3660     case ARM::tADDrSPi:
3661       Inst.addOperand(MCOperand::createReg(ARM::SP));
3662       break;
3663   }
3664 
3665   Inst.addOperand(MCOperand::createImm(imm));
3666   return S;
3667 }
3668 
3669 static DecodeStatus DecodeThumbBROperand(MCInst &Inst, unsigned Val,
3670                                  uint64_t Address, const void *Decoder) {
3671   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<12>(Val<<1) + 4,
3672                                 true, 2, Inst, Decoder))
3673     Inst.addOperand(MCOperand::createImm(SignExtend32<12>(Val << 1)));
3674   return MCDisassembler::Success;
3675 }
3676 
3677 static DecodeStatus DecodeT2BROperand(MCInst &Inst, unsigned Val,
3678                                  uint64_t Address, const void *Decoder) {
3679   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<21>(Val) + 4,
3680                                 true, 4, Inst, Decoder))
3681     Inst.addOperand(MCOperand::createImm(SignExtend32<21>(Val)));
3682   return MCDisassembler::Success;
3683 }
3684 
3685 static DecodeStatus DecodeThumbCmpBROperand(MCInst &Inst, unsigned Val,
3686                                  uint64_t Address, const void *Decoder) {
3687   if (!tryAddingSymbolicOperand(Address, Address + (Val<<1) + 4,
3688                                 true, 2, Inst, Decoder))
3689     Inst.addOperand(MCOperand::createImm(Val << 1));
3690   return MCDisassembler::Success;
3691 }
3692 
3693 static DecodeStatus DecodeThumbAddrModeRR(MCInst &Inst, unsigned Val,
3694                                  uint64_t Address, const void *Decoder) {
3695   DecodeStatus S = MCDisassembler::Success;
3696 
3697   unsigned Rn = fieldFromInstruction(Val, 0, 3);
3698   unsigned Rm = fieldFromInstruction(Val, 3, 3);
3699 
3700   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
3701     return MCDisassembler::Fail;
3702   if (!Check(S, DecodetGPRRegisterClass(Inst, Rm, Address, Decoder)))
3703     return MCDisassembler::Fail;
3704 
3705   return S;
3706 }
3707 
3708 static DecodeStatus DecodeThumbAddrModeIS(MCInst &Inst, unsigned Val,
3709                                   uint64_t Address, const void *Decoder) {
3710   DecodeStatus S = MCDisassembler::Success;
3711 
3712   unsigned Rn = fieldFromInstruction(Val, 0, 3);
3713   unsigned imm = fieldFromInstruction(Val, 3, 5);
3714 
3715   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
3716     return MCDisassembler::Fail;
3717   Inst.addOperand(MCOperand::createImm(imm));
3718 
3719   return S;
3720 }
3721 
3722 static DecodeStatus DecodeThumbAddrModePC(MCInst &Inst, unsigned Val,
3723                                   uint64_t Address, const void *Decoder) {
3724   unsigned imm = Val << 2;
3725 
3726   Inst.addOperand(MCOperand::createImm(imm));
3727   tryAddingPcLoadReferenceComment(Address, (Address & ~2u) + imm + 4, Decoder);
3728 
3729   return MCDisassembler::Success;
3730 }
3731 
3732 static DecodeStatus DecodeThumbAddrModeSP(MCInst &Inst, unsigned Val,
3733                                   uint64_t Address, const void *Decoder) {
3734   Inst.addOperand(MCOperand::createReg(ARM::SP));
3735   Inst.addOperand(MCOperand::createImm(Val));
3736 
3737   return MCDisassembler::Success;
3738 }
3739 
3740 static DecodeStatus DecodeT2AddrModeSOReg(MCInst &Inst, unsigned Val,
3741                                   uint64_t Address, const void *Decoder) {
3742   DecodeStatus S = MCDisassembler::Success;
3743 
3744   unsigned Rn = fieldFromInstruction(Val, 6, 4);
3745   unsigned Rm = fieldFromInstruction(Val, 2, 4);
3746   unsigned imm = fieldFromInstruction(Val, 0, 2);
3747 
3748   // Thumb stores cannot use PC as dest register.
3749   switch (Inst.getOpcode()) {
3750   case ARM::t2STRHs:
3751   case ARM::t2STRBs:
3752   case ARM::t2STRs:
3753     if (Rn == 15)
3754       return MCDisassembler::Fail;
3755     break;
3756   default:
3757     break;
3758   }
3759 
3760   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3761     return MCDisassembler::Fail;
3762   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
3763     return MCDisassembler::Fail;
3764   Inst.addOperand(MCOperand::createImm(imm));
3765 
3766   return S;
3767 }
3768 
3769 static DecodeStatus DecodeT2LoadShift(MCInst &Inst, unsigned Insn,
3770                               uint64_t Address, const void *Decoder) {
3771   DecodeStatus S = MCDisassembler::Success;
3772 
3773   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3774   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3775 
3776   const FeatureBitset &featureBits =
3777     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3778 
3779   bool hasMP = featureBits[ARM::FeatureMP];
3780   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3781 
3782   if (Rn == 15) {
3783     switch (Inst.getOpcode()) {
3784     case ARM::t2LDRBs:
3785       Inst.setOpcode(ARM::t2LDRBpci);
3786       break;
3787     case ARM::t2LDRHs:
3788       Inst.setOpcode(ARM::t2LDRHpci);
3789       break;
3790     case ARM::t2LDRSHs:
3791       Inst.setOpcode(ARM::t2LDRSHpci);
3792       break;
3793     case ARM::t2LDRSBs:
3794       Inst.setOpcode(ARM::t2LDRSBpci);
3795       break;
3796     case ARM::t2LDRs:
3797       Inst.setOpcode(ARM::t2LDRpci);
3798       break;
3799     case ARM::t2PLDs:
3800       Inst.setOpcode(ARM::t2PLDpci);
3801       break;
3802     case ARM::t2PLIs:
3803       Inst.setOpcode(ARM::t2PLIpci);
3804       break;
3805     default:
3806       return MCDisassembler::Fail;
3807     }
3808 
3809     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3810   }
3811 
3812   if (Rt == 15) {
3813     switch (Inst.getOpcode()) {
3814     case ARM::t2LDRSHs:
3815       return MCDisassembler::Fail;
3816     case ARM::t2LDRHs:
3817       Inst.setOpcode(ARM::t2PLDWs);
3818       break;
3819     case ARM::t2LDRSBs:
3820       Inst.setOpcode(ARM::t2PLIs);
3821       break;
3822     default:
3823       break;
3824     }
3825   }
3826 
3827   switch (Inst.getOpcode()) {
3828     case ARM::t2PLDs:
3829       break;
3830     case ARM::t2PLIs:
3831       if (!hasV7Ops)
3832         return MCDisassembler::Fail;
3833       break;
3834     case ARM::t2PLDWs:
3835       if (!hasV7Ops || !hasMP)
3836         return MCDisassembler::Fail;
3837       break;
3838     default:
3839       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3840         return MCDisassembler::Fail;
3841   }
3842 
3843   unsigned addrmode = fieldFromInstruction(Insn, 4, 2);
3844   addrmode |= fieldFromInstruction(Insn, 0, 4) << 2;
3845   addrmode |= fieldFromInstruction(Insn, 16, 4) << 6;
3846   if (!Check(S, DecodeT2AddrModeSOReg(Inst, addrmode, Address, Decoder)))
3847     return MCDisassembler::Fail;
3848 
3849   return S;
3850 }
3851 
3852 static DecodeStatus DecodeT2LoadImm8(MCInst &Inst, unsigned Insn,
3853                                 uint64_t Address, const void* Decoder) {
3854   DecodeStatus S = MCDisassembler::Success;
3855 
3856   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3857   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3858   unsigned U = fieldFromInstruction(Insn, 9, 1);
3859   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3860   imm |= (U << 8);
3861   imm |= (Rn << 9);
3862   unsigned add = fieldFromInstruction(Insn, 9, 1);
3863 
3864   const FeatureBitset &featureBits =
3865     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3866 
3867   bool hasMP = featureBits[ARM::FeatureMP];
3868   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3869 
3870   if (Rn == 15) {
3871     switch (Inst.getOpcode()) {
3872     case ARM::t2LDRi8:
3873       Inst.setOpcode(ARM::t2LDRpci);
3874       break;
3875     case ARM::t2LDRBi8:
3876       Inst.setOpcode(ARM::t2LDRBpci);
3877       break;
3878     case ARM::t2LDRSBi8:
3879       Inst.setOpcode(ARM::t2LDRSBpci);
3880       break;
3881     case ARM::t2LDRHi8:
3882       Inst.setOpcode(ARM::t2LDRHpci);
3883       break;
3884     case ARM::t2LDRSHi8:
3885       Inst.setOpcode(ARM::t2LDRSHpci);
3886       break;
3887     case ARM::t2PLDi8:
3888       Inst.setOpcode(ARM::t2PLDpci);
3889       break;
3890     case ARM::t2PLIi8:
3891       Inst.setOpcode(ARM::t2PLIpci);
3892       break;
3893     default:
3894       return MCDisassembler::Fail;
3895     }
3896     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3897   }
3898 
3899   if (Rt == 15) {
3900     switch (Inst.getOpcode()) {
3901     case ARM::t2LDRSHi8:
3902       return MCDisassembler::Fail;
3903     case ARM::t2LDRHi8:
3904       if (!add)
3905         Inst.setOpcode(ARM::t2PLDWi8);
3906       break;
3907     case ARM::t2LDRSBi8:
3908       Inst.setOpcode(ARM::t2PLIi8);
3909       break;
3910     default:
3911       break;
3912     }
3913   }
3914 
3915   switch (Inst.getOpcode()) {
3916   case ARM::t2PLDi8:
3917     break;
3918   case ARM::t2PLIi8:
3919     if (!hasV7Ops)
3920       return MCDisassembler::Fail;
3921     break;
3922   case ARM::t2PLDWi8:
3923       if (!hasV7Ops || !hasMP)
3924         return MCDisassembler::Fail;
3925       break;
3926   default:
3927     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3928       return MCDisassembler::Fail;
3929   }
3930 
3931   if (!Check(S, DecodeT2AddrModeImm8(Inst, imm, Address, Decoder)))
3932     return MCDisassembler::Fail;
3933   return S;
3934 }
3935 
3936 static DecodeStatus DecodeT2LoadImm12(MCInst &Inst, unsigned Insn,
3937                                 uint64_t Address, const void* Decoder) {
3938   DecodeStatus S = MCDisassembler::Success;
3939 
3940   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3941   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3942   unsigned imm = fieldFromInstruction(Insn, 0, 12);
3943   imm |= (Rn << 13);
3944 
3945   const FeatureBitset &featureBits =
3946     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3947 
3948   bool hasMP = featureBits[ARM::FeatureMP];
3949   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3950 
3951   if (Rn == 15) {
3952     switch (Inst.getOpcode()) {
3953     case ARM::t2LDRi12:
3954       Inst.setOpcode(ARM::t2LDRpci);
3955       break;
3956     case ARM::t2LDRHi12:
3957       Inst.setOpcode(ARM::t2LDRHpci);
3958       break;
3959     case ARM::t2LDRSHi12:
3960       Inst.setOpcode(ARM::t2LDRSHpci);
3961       break;
3962     case ARM::t2LDRBi12:
3963       Inst.setOpcode(ARM::t2LDRBpci);
3964       break;
3965     case ARM::t2LDRSBi12:
3966       Inst.setOpcode(ARM::t2LDRSBpci);
3967       break;
3968     case ARM::t2PLDi12:
3969       Inst.setOpcode(ARM::t2PLDpci);
3970       break;
3971     case ARM::t2PLIi12:
3972       Inst.setOpcode(ARM::t2PLIpci);
3973       break;
3974     default:
3975       return MCDisassembler::Fail;
3976     }
3977     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3978   }
3979 
3980   if (Rt == 15) {
3981     switch (Inst.getOpcode()) {
3982     case ARM::t2LDRSHi12:
3983       return MCDisassembler::Fail;
3984     case ARM::t2LDRHi12:
3985       Inst.setOpcode(ARM::t2PLDWi12);
3986       break;
3987     case ARM::t2LDRSBi12:
3988       Inst.setOpcode(ARM::t2PLIi12);
3989       break;
3990     default:
3991       break;
3992     }
3993   }
3994 
3995   switch (Inst.getOpcode()) {
3996   case ARM::t2PLDi12:
3997     break;
3998   case ARM::t2PLIi12:
3999     if (!hasV7Ops)
4000       return MCDisassembler::Fail;
4001     break;
4002   case ARM::t2PLDWi12:
4003       if (!hasV7Ops || !hasMP)
4004         return MCDisassembler::Fail;
4005       break;
4006   default:
4007     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4008       return MCDisassembler::Fail;
4009   }
4010 
4011   if (!Check(S, DecodeT2AddrModeImm12(Inst, imm, Address, Decoder)))
4012     return MCDisassembler::Fail;
4013   return S;
4014 }
4015 
4016 static DecodeStatus DecodeT2LoadT(MCInst &Inst, unsigned Insn,
4017                                 uint64_t Address, const void* Decoder) {
4018   DecodeStatus S = MCDisassembler::Success;
4019 
4020   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4021   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4022   unsigned imm = fieldFromInstruction(Insn, 0, 8);
4023   imm |= (Rn << 9);
4024 
4025   if (Rn == 15) {
4026     switch (Inst.getOpcode()) {
4027     case ARM::t2LDRT:
4028       Inst.setOpcode(ARM::t2LDRpci);
4029       break;
4030     case ARM::t2LDRBT:
4031       Inst.setOpcode(ARM::t2LDRBpci);
4032       break;
4033     case ARM::t2LDRHT:
4034       Inst.setOpcode(ARM::t2LDRHpci);
4035       break;
4036     case ARM::t2LDRSBT:
4037       Inst.setOpcode(ARM::t2LDRSBpci);
4038       break;
4039     case ARM::t2LDRSHT:
4040       Inst.setOpcode(ARM::t2LDRSHpci);
4041       break;
4042     default:
4043       return MCDisassembler::Fail;
4044     }
4045     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
4046   }
4047 
4048   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
4049     return MCDisassembler::Fail;
4050   if (!Check(S, DecodeT2AddrModeImm8(Inst, imm, Address, Decoder)))
4051     return MCDisassembler::Fail;
4052   return S;
4053 }
4054 
4055 static DecodeStatus DecodeT2LoadLabel(MCInst &Inst, unsigned Insn,
4056                                 uint64_t Address, const void* Decoder) {
4057   DecodeStatus S = MCDisassembler::Success;
4058 
4059   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4060   unsigned U = fieldFromInstruction(Insn, 23, 1);
4061   int imm = fieldFromInstruction(Insn, 0, 12);
4062 
4063   const FeatureBitset &featureBits =
4064     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4065 
4066   bool hasV7Ops = featureBits[ARM::HasV7Ops];
4067 
4068   if (Rt == 15) {
4069     switch (Inst.getOpcode()) {
4070       case ARM::t2LDRBpci:
4071       case ARM::t2LDRHpci:
4072         Inst.setOpcode(ARM::t2PLDpci);
4073         break;
4074       case ARM::t2LDRSBpci:
4075         Inst.setOpcode(ARM::t2PLIpci);
4076         break;
4077       case ARM::t2LDRSHpci:
4078         return MCDisassembler::Fail;
4079       default:
4080         break;
4081     }
4082   }
4083 
4084   switch(Inst.getOpcode()) {
4085   case ARM::t2PLDpci:
4086     break;
4087   case ARM::t2PLIpci:
4088     if (!hasV7Ops)
4089       return MCDisassembler::Fail;
4090     break;
4091   default:
4092     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4093       return MCDisassembler::Fail;
4094   }
4095 
4096   if (!U) {
4097     // Special case for #-0.
4098     if (imm == 0)
4099       imm = INT32_MIN;
4100     else
4101       imm = -imm;
4102   }
4103   Inst.addOperand(MCOperand::createImm(imm));
4104 
4105   return S;
4106 }
4107 
4108 static DecodeStatus DecodeT2Imm8S4(MCInst &Inst, unsigned Val,
4109                            uint64_t Address, const void *Decoder) {
4110   if (Val == 0)
4111     Inst.addOperand(MCOperand::createImm(INT32_MIN));
4112   else {
4113     int imm = Val & 0xFF;
4114 
4115     if (!(Val & 0x100)) imm *= -1;
4116     Inst.addOperand(MCOperand::createImm(imm * 4));
4117   }
4118 
4119   return MCDisassembler::Success;
4120 }
4121 
4122 static DecodeStatus DecodeT2Imm7S4(MCInst &Inst, unsigned Val, uint64_t Address,
4123                                    const void *Decoder) {
4124   if (Val == 0)
4125     Inst.addOperand(MCOperand::createImm(INT32_MIN));
4126   else {
4127     int imm = Val & 0x7F;
4128 
4129     if (!(Val & 0x80))
4130       imm *= -1;
4131     Inst.addOperand(MCOperand::createImm(imm * 4));
4132   }
4133 
4134   return MCDisassembler::Success;
4135 }
4136 
4137 static DecodeStatus DecodeT2AddrModeImm8s4(MCInst &Inst, unsigned Val,
4138                                    uint64_t Address, const void *Decoder) {
4139   DecodeStatus S = MCDisassembler::Success;
4140 
4141   unsigned Rn = fieldFromInstruction(Val, 9, 4);
4142   unsigned imm = fieldFromInstruction(Val, 0, 9);
4143 
4144   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4145     return MCDisassembler::Fail;
4146   if (!Check(S, DecodeT2Imm8S4(Inst, imm, Address, Decoder)))
4147     return MCDisassembler::Fail;
4148 
4149   return S;
4150 }
4151 
4152 static DecodeStatus DecodeT2AddrModeImm7s4(MCInst &Inst, unsigned Val,
4153                                            uint64_t Address,
4154                                            const void *Decoder) {
4155   DecodeStatus S = MCDisassembler::Success;
4156 
4157   unsigned Rn = fieldFromInstruction(Val, 8, 4);
4158   unsigned imm = fieldFromInstruction(Val, 0, 8);
4159 
4160   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4161     return MCDisassembler::Fail;
4162   if (!Check(S, DecodeT2Imm7S4(Inst, imm, Address, Decoder)))
4163     return MCDisassembler::Fail;
4164 
4165   return S;
4166 }
4167 
4168 static DecodeStatus DecodeT2AddrModeImm0_1020s4(MCInst &Inst,unsigned Val,
4169                                    uint64_t Address, const void *Decoder) {
4170   DecodeStatus S = MCDisassembler::Success;
4171 
4172   unsigned Rn = fieldFromInstruction(Val, 8, 4);
4173   unsigned imm = fieldFromInstruction(Val, 0, 8);
4174 
4175   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4176     return MCDisassembler::Fail;
4177 
4178   Inst.addOperand(MCOperand::createImm(imm));
4179 
4180   return S;
4181 }
4182 
4183 static DecodeStatus DecodeT2Imm8(MCInst &Inst, unsigned Val,
4184                          uint64_t Address, const void *Decoder) {
4185   int imm = Val & 0xFF;
4186   if (Val == 0)
4187     imm = INT32_MIN;
4188   else if (!(Val & 0x100))
4189     imm *= -1;
4190   Inst.addOperand(MCOperand::createImm(imm));
4191 
4192   return MCDisassembler::Success;
4193 }
4194 
4195 template<int shift>
4196 static DecodeStatus DecodeT2Imm7(MCInst &Inst, unsigned Val,
4197                          uint64_t Address, const void *Decoder) {
4198   int imm = Val & 0x7F;
4199   if (Val == 0)
4200     imm = INT32_MIN;
4201   else if (!(Val & 0x80))
4202     imm *= -1;
4203   if (imm != INT32_MIN)
4204     imm *= (1U << shift);
4205   Inst.addOperand(MCOperand::createImm(imm));
4206 
4207   return MCDisassembler::Success;
4208 }
4209 
4210 static DecodeStatus DecodeT2AddrModeImm8(MCInst &Inst, unsigned Val,
4211                                  uint64_t Address, const void *Decoder) {
4212   DecodeStatus S = MCDisassembler::Success;
4213 
4214   unsigned Rn = fieldFromInstruction(Val, 9, 4);
4215   unsigned imm = fieldFromInstruction(Val, 0, 9);
4216 
4217   // Thumb stores cannot use PC as dest register.
4218   switch (Inst.getOpcode()) {
4219   case ARM::t2STRT:
4220   case ARM::t2STRBT:
4221   case ARM::t2STRHT:
4222   case ARM::t2STRi8:
4223   case ARM::t2STRHi8:
4224   case ARM::t2STRBi8:
4225     if (Rn == 15)
4226       return MCDisassembler::Fail;
4227     break;
4228   default:
4229     break;
4230   }
4231 
4232   // Some instructions always use an additive offset.
4233   switch (Inst.getOpcode()) {
4234     case ARM::t2LDRT:
4235     case ARM::t2LDRBT:
4236     case ARM::t2LDRHT:
4237     case ARM::t2LDRSBT:
4238     case ARM::t2LDRSHT:
4239     case ARM::t2STRT:
4240     case ARM::t2STRBT:
4241     case ARM::t2STRHT:
4242       imm |= 0x100;
4243       break;
4244     default:
4245       break;
4246   }
4247 
4248   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4249     return MCDisassembler::Fail;
4250   if (!Check(S, DecodeT2Imm8(Inst, imm, Address, Decoder)))
4251     return MCDisassembler::Fail;
4252 
4253   return S;
4254 }
4255 
4256 template<int shift>
4257 static DecodeStatus DecodeTAddrModeImm7(MCInst &Inst, unsigned Val,
4258                                          uint64_t Address,
4259                                          const void *Decoder) {
4260   DecodeStatus S = MCDisassembler::Success;
4261 
4262   unsigned Rn = fieldFromInstruction(Val, 8, 3);
4263   unsigned imm = fieldFromInstruction(Val, 0, 8);
4264 
4265   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
4266     return MCDisassembler::Fail;
4267   if (!Check(S, DecodeT2Imm7<shift>(Inst, imm, Address, Decoder)))
4268     return MCDisassembler::Fail;
4269 
4270   return S;
4271 }
4272 
4273 template<int shift, int WriteBack>
4274 static DecodeStatus DecodeT2AddrModeImm7(MCInst &Inst, unsigned Val,
4275                                          uint64_t Address,
4276                                          const void *Decoder) {
4277   DecodeStatus S = MCDisassembler::Success;
4278 
4279   unsigned Rn = fieldFromInstruction(Val, 8, 4);
4280   unsigned imm = fieldFromInstruction(Val, 0, 8);
4281   if (WriteBack) {
4282     if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
4283       return MCDisassembler::Fail;
4284   } else if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4285     return MCDisassembler::Fail;
4286   if (!Check(S, DecodeT2Imm7<shift>(Inst, imm, Address, Decoder)))
4287     return MCDisassembler::Fail;
4288 
4289   return S;
4290 }
4291 
4292 static DecodeStatus DecodeT2LdStPre(MCInst &Inst, unsigned Insn,
4293                                     uint64_t Address, const void *Decoder) {
4294   DecodeStatus S = MCDisassembler::Success;
4295 
4296   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4297   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4298   unsigned addr = fieldFromInstruction(Insn, 0, 8);
4299   addr |= fieldFromInstruction(Insn, 9, 1) << 8;
4300   addr |= Rn << 9;
4301   unsigned load = fieldFromInstruction(Insn, 20, 1);
4302 
4303   if (Rn == 15) {
4304     switch (Inst.getOpcode()) {
4305     case ARM::t2LDR_PRE:
4306     case ARM::t2LDR_POST:
4307       Inst.setOpcode(ARM::t2LDRpci);
4308       break;
4309     case ARM::t2LDRB_PRE:
4310     case ARM::t2LDRB_POST:
4311       Inst.setOpcode(ARM::t2LDRBpci);
4312       break;
4313     case ARM::t2LDRH_PRE:
4314     case ARM::t2LDRH_POST:
4315       Inst.setOpcode(ARM::t2LDRHpci);
4316       break;
4317     case ARM::t2LDRSB_PRE:
4318     case ARM::t2LDRSB_POST:
4319       if (Rt == 15)
4320         Inst.setOpcode(ARM::t2PLIpci);
4321       else
4322         Inst.setOpcode(ARM::t2LDRSBpci);
4323       break;
4324     case ARM::t2LDRSH_PRE:
4325     case ARM::t2LDRSH_POST:
4326       Inst.setOpcode(ARM::t2LDRSHpci);
4327       break;
4328     default:
4329       return MCDisassembler::Fail;
4330     }
4331     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
4332   }
4333 
4334   if (!load) {
4335     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4336       return MCDisassembler::Fail;
4337   }
4338 
4339   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4340     return MCDisassembler::Fail;
4341 
4342   if (load) {
4343     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4344       return MCDisassembler::Fail;
4345   }
4346 
4347   if (!Check(S, DecodeT2AddrModeImm8(Inst, addr, Address, Decoder)))
4348     return MCDisassembler::Fail;
4349 
4350   return S;
4351 }
4352 
4353 static DecodeStatus DecodeT2AddrModeImm12(MCInst &Inst, unsigned Val,
4354                                   uint64_t Address, const void *Decoder) {
4355   DecodeStatus S = MCDisassembler::Success;
4356 
4357   unsigned Rn = fieldFromInstruction(Val, 13, 4);
4358   unsigned imm = fieldFromInstruction(Val, 0, 12);
4359 
4360   // Thumb stores cannot use PC as dest register.
4361   switch (Inst.getOpcode()) {
4362   case ARM::t2STRi12:
4363   case ARM::t2STRBi12:
4364   case ARM::t2STRHi12:
4365     if (Rn == 15)
4366       return MCDisassembler::Fail;
4367     break;
4368   default:
4369     break;
4370   }
4371 
4372   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4373     return MCDisassembler::Fail;
4374   Inst.addOperand(MCOperand::createImm(imm));
4375 
4376   return S;
4377 }
4378 
4379 static DecodeStatus DecodeThumbAddSPImm(MCInst &Inst, uint16_t Insn,
4380                                 uint64_t Address, const void *Decoder) {
4381   unsigned imm = fieldFromInstruction(Insn, 0, 7);
4382 
4383   Inst.addOperand(MCOperand::createReg(ARM::SP));
4384   Inst.addOperand(MCOperand::createReg(ARM::SP));
4385   Inst.addOperand(MCOperand::createImm(imm));
4386 
4387   return MCDisassembler::Success;
4388 }
4389 
4390 static DecodeStatus DecodeThumbAddSPReg(MCInst &Inst, uint16_t Insn,
4391                                 uint64_t Address, const void *Decoder) {
4392   DecodeStatus S = MCDisassembler::Success;
4393 
4394   if (Inst.getOpcode() == ARM::tADDrSP) {
4395     unsigned Rdm = fieldFromInstruction(Insn, 0, 3);
4396     Rdm |= fieldFromInstruction(Insn, 7, 1) << 3;
4397 
4398     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
4399     return MCDisassembler::Fail;
4400     Inst.addOperand(MCOperand::createReg(ARM::SP));
4401     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
4402     return MCDisassembler::Fail;
4403   } else if (Inst.getOpcode() == ARM::tADDspr) {
4404     unsigned Rm = fieldFromInstruction(Insn, 3, 4);
4405 
4406     Inst.addOperand(MCOperand::createReg(ARM::SP));
4407     Inst.addOperand(MCOperand::createReg(ARM::SP));
4408     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4409     return MCDisassembler::Fail;
4410   }
4411 
4412   return S;
4413 }
4414 
4415 static DecodeStatus DecodeThumbCPS(MCInst &Inst, uint16_t Insn,
4416                            uint64_t Address, const void *Decoder) {
4417   unsigned imod = fieldFromInstruction(Insn, 4, 1) | 0x2;
4418   unsigned flags = fieldFromInstruction(Insn, 0, 3);
4419 
4420   Inst.addOperand(MCOperand::createImm(imod));
4421   Inst.addOperand(MCOperand::createImm(flags));
4422 
4423   return MCDisassembler::Success;
4424 }
4425 
4426 static DecodeStatus DecodePostIdxReg(MCInst &Inst, unsigned Insn,
4427                              uint64_t Address, const void *Decoder) {
4428   DecodeStatus S = MCDisassembler::Success;
4429   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4430   unsigned add = fieldFromInstruction(Insn, 4, 1);
4431 
4432   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
4433     return MCDisassembler::Fail;
4434   Inst.addOperand(MCOperand::createImm(add));
4435 
4436   return S;
4437 }
4438 
4439 static DecodeStatus DecodeMveAddrModeRQ(MCInst &Inst, unsigned Insn,
4440                              uint64_t Address, const void *Decoder) {
4441   DecodeStatus S = MCDisassembler::Success;
4442   unsigned Rn = fieldFromInstruction(Insn, 3, 4);
4443   unsigned Qm = fieldFromInstruction(Insn, 0, 3);
4444 
4445   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4446     return MCDisassembler::Fail;
4447   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
4448     return MCDisassembler::Fail;
4449 
4450   return S;
4451 }
4452 
4453 template<int shift>
4454 static DecodeStatus DecodeMveAddrModeQ(MCInst &Inst, unsigned Insn,
4455                              uint64_t Address, const void *Decoder) {
4456   DecodeStatus S = MCDisassembler::Success;
4457   unsigned Qm = fieldFromInstruction(Insn, 8, 3);
4458   int imm = fieldFromInstruction(Insn, 0, 7);
4459 
4460   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
4461     return MCDisassembler::Fail;
4462 
4463   if(!fieldFromInstruction(Insn, 7, 1)) {
4464     if (imm == 0)
4465       imm = INT32_MIN;                 // indicate -0
4466     else
4467       imm *= -1;
4468   }
4469   if (imm != INT32_MIN)
4470     imm *= (1U << shift);
4471   Inst.addOperand(MCOperand::createImm(imm));
4472 
4473   return S;
4474 }
4475 
4476 static DecodeStatus DecodeThumbBLXOffset(MCInst &Inst, unsigned Val,
4477                                  uint64_t Address, const void *Decoder) {
4478   // Val is passed in as S:J1:J2:imm10H:imm10L:'0'
4479   // Note only one trailing zero not two.  Also the J1 and J2 values are from
4480   // the encoded instruction.  So here change to I1 and I2 values via:
4481   // I1 = NOT(J1 EOR S);
4482   // I2 = NOT(J2 EOR S);
4483   // and build the imm32 with two trailing zeros as documented:
4484   // imm32 = SignExtend(S:I1:I2:imm10H:imm10L:'00', 32);
4485   unsigned S = (Val >> 23) & 1;
4486   unsigned J1 = (Val >> 22) & 1;
4487   unsigned J2 = (Val >> 21) & 1;
4488   unsigned I1 = !(J1 ^ S);
4489   unsigned I2 = !(J2 ^ S);
4490   unsigned tmp = (Val & ~0x600000) | (I1 << 22) | (I2 << 21);
4491   int imm32 = SignExtend32<25>(tmp << 1);
4492 
4493   if (!tryAddingSymbolicOperand(Address,
4494                                 (Address & ~2u) + imm32 + 4,
4495                                 true, 4, Inst, Decoder))
4496     Inst.addOperand(MCOperand::createImm(imm32));
4497   return MCDisassembler::Success;
4498 }
4499 
4500 static DecodeStatus DecodeCoprocessor(MCInst &Inst, unsigned Val,
4501                               uint64_t Address, const void *Decoder) {
4502   if (Val == 0xA || Val == 0xB)
4503     return MCDisassembler::Fail;
4504 
4505   const FeatureBitset &featureBits =
4506     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4507 
4508   if (!isValidCoprocessorNumber(Val, featureBits))
4509     return MCDisassembler::Fail;
4510 
4511   Inst.addOperand(MCOperand::createImm(Val));
4512   return MCDisassembler::Success;
4513 }
4514 
4515 static DecodeStatus
4516 DecodeThumbTableBranch(MCInst &Inst, unsigned Insn,
4517                        uint64_t Address, const void *Decoder) {
4518   DecodeStatus S = MCDisassembler::Success;
4519 
4520   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4521   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4522 
4523   if (Rn == ARM::SP) S = MCDisassembler::SoftFail;
4524   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4525     return MCDisassembler::Fail;
4526   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
4527     return MCDisassembler::Fail;
4528   return S;
4529 }
4530 
4531 static DecodeStatus
4532 DecodeThumb2BCCInstruction(MCInst &Inst, unsigned Insn,
4533                            uint64_t Address, const void *Decoder) {
4534   DecodeStatus S = MCDisassembler::Success;
4535 
4536   unsigned pred = fieldFromInstruction(Insn, 22, 4);
4537   if (pred == 0xE || pred == 0xF) {
4538     unsigned opc = fieldFromInstruction(Insn, 4, 28);
4539     switch (opc) {
4540       default:
4541         return MCDisassembler::Fail;
4542       case 0xf3bf8f4:
4543         Inst.setOpcode(ARM::t2DSB);
4544         break;
4545       case 0xf3bf8f5:
4546         Inst.setOpcode(ARM::t2DMB);
4547         break;
4548       case 0xf3bf8f6:
4549         Inst.setOpcode(ARM::t2ISB);
4550         break;
4551     }
4552 
4553     unsigned imm = fieldFromInstruction(Insn, 0, 4);
4554     return DecodeMemBarrierOption(Inst, imm, Address, Decoder);
4555   }
4556 
4557   unsigned brtarget = fieldFromInstruction(Insn, 0, 11) << 1;
4558   brtarget |= fieldFromInstruction(Insn, 11, 1) << 19;
4559   brtarget |= fieldFromInstruction(Insn, 13, 1) << 18;
4560   brtarget |= fieldFromInstruction(Insn, 16, 6) << 12;
4561   brtarget |= fieldFromInstruction(Insn, 26, 1) << 20;
4562 
4563   if (!Check(S, DecodeT2BROperand(Inst, brtarget, Address, Decoder)))
4564     return MCDisassembler::Fail;
4565   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4566     return MCDisassembler::Fail;
4567 
4568   return S;
4569 }
4570 
4571 // Decode a shifted immediate operand.  These basically consist
4572 // of an 8-bit value, and a 4-bit directive that specifies either
4573 // a splat operation or a rotation.
4574 static DecodeStatus DecodeT2SOImm(MCInst &Inst, unsigned Val,
4575                           uint64_t Address, const void *Decoder) {
4576   unsigned ctrl = fieldFromInstruction(Val, 10, 2);
4577   if (ctrl == 0) {
4578     unsigned byte = fieldFromInstruction(Val, 8, 2);
4579     unsigned imm = fieldFromInstruction(Val, 0, 8);
4580     switch (byte) {
4581       case 0:
4582         Inst.addOperand(MCOperand::createImm(imm));
4583         break;
4584       case 1:
4585         Inst.addOperand(MCOperand::createImm((imm << 16) | imm));
4586         break;
4587       case 2:
4588         Inst.addOperand(MCOperand::createImm((imm << 24) | (imm << 8)));
4589         break;
4590       case 3:
4591         Inst.addOperand(MCOperand::createImm((imm << 24) | (imm << 16) |
4592                                              (imm << 8)  |  imm));
4593         break;
4594     }
4595   } else {
4596     unsigned unrot = fieldFromInstruction(Val, 0, 7) | 0x80;
4597     unsigned rot = fieldFromInstruction(Val, 7, 5);
4598     unsigned imm = (unrot >> rot) | (unrot << ((32-rot)&31));
4599     Inst.addOperand(MCOperand::createImm(imm));
4600   }
4601 
4602   return MCDisassembler::Success;
4603 }
4604 
4605 static DecodeStatus
4606 DecodeThumbBCCTargetOperand(MCInst &Inst, unsigned Val,
4607                             uint64_t Address, const void *Decoder) {
4608   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<9>(Val<<1) + 4,
4609                                 true, 2, Inst, Decoder))
4610     Inst.addOperand(MCOperand::createImm(SignExtend32<9>(Val << 1)));
4611   return MCDisassembler::Success;
4612 }
4613 
4614 static DecodeStatus DecodeThumbBLTargetOperand(MCInst &Inst, unsigned Val,
4615                                                uint64_t Address,
4616                                                const void *Decoder) {
4617   // Val is passed in as S:J1:J2:imm10:imm11
4618   // Note no trailing zero after imm11.  Also the J1 and J2 values are from
4619   // the encoded instruction.  So here change to I1 and I2 values via:
4620   // I1 = NOT(J1 EOR S);
4621   // I2 = NOT(J2 EOR S);
4622   // and build the imm32 with one trailing zero as documented:
4623   // imm32 = SignExtend(S:I1:I2:imm10:imm11:'0', 32);
4624   unsigned S = (Val >> 23) & 1;
4625   unsigned J1 = (Val >> 22) & 1;
4626   unsigned J2 = (Val >> 21) & 1;
4627   unsigned I1 = !(J1 ^ S);
4628   unsigned I2 = !(J2 ^ S);
4629   unsigned tmp = (Val & ~0x600000) | (I1 << 22) | (I2 << 21);
4630   int imm32 = SignExtend32<25>(tmp << 1);
4631 
4632   if (!tryAddingSymbolicOperand(Address, Address + imm32 + 4,
4633                                 true, 4, Inst, Decoder))
4634     Inst.addOperand(MCOperand::createImm(imm32));
4635   return MCDisassembler::Success;
4636 }
4637 
4638 static DecodeStatus DecodeMemBarrierOption(MCInst &Inst, unsigned Val,
4639                                    uint64_t Address, const void *Decoder) {
4640   if (Val & ~0xf)
4641     return MCDisassembler::Fail;
4642 
4643   Inst.addOperand(MCOperand::createImm(Val));
4644   return MCDisassembler::Success;
4645 }
4646 
4647 static DecodeStatus DecodeInstSyncBarrierOption(MCInst &Inst, unsigned Val,
4648                                         uint64_t Address, const void *Decoder) {
4649   if (Val & ~0xf)
4650     return MCDisassembler::Fail;
4651 
4652   Inst.addOperand(MCOperand::createImm(Val));
4653   return MCDisassembler::Success;
4654 }
4655 
4656 static DecodeStatus DecodeMSRMask(MCInst &Inst, unsigned Val,
4657                           uint64_t Address, const void *Decoder) {
4658   DecodeStatus S = MCDisassembler::Success;
4659   const FeatureBitset &FeatureBits =
4660     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4661 
4662   if (FeatureBits[ARM::FeatureMClass]) {
4663     unsigned ValLow = Val & 0xff;
4664 
4665     // Validate the SYSm value first.
4666     switch (ValLow) {
4667     case  0: // apsr
4668     case  1: // iapsr
4669     case  2: // eapsr
4670     case  3: // xpsr
4671     case  5: // ipsr
4672     case  6: // epsr
4673     case  7: // iepsr
4674     case  8: // msp
4675     case  9: // psp
4676     case 16: // primask
4677     case 20: // control
4678       break;
4679     case 17: // basepri
4680     case 18: // basepri_max
4681     case 19: // faultmask
4682       if (!(FeatureBits[ARM::HasV7Ops]))
4683         // Values basepri, basepri_max and faultmask are only valid for v7m.
4684         return MCDisassembler::Fail;
4685       break;
4686     case 0x8a: // msplim_ns
4687     case 0x8b: // psplim_ns
4688     case 0x91: // basepri_ns
4689     case 0x93: // faultmask_ns
4690       if (!(FeatureBits[ARM::HasV8MMainlineOps]))
4691         return MCDisassembler::Fail;
4692       LLVM_FALLTHROUGH;
4693     case 10:   // msplim
4694     case 11:   // psplim
4695     case 0x88: // msp_ns
4696     case 0x89: // psp_ns
4697     case 0x90: // primask_ns
4698     case 0x94: // control_ns
4699     case 0x98: // sp_ns
4700       if (!(FeatureBits[ARM::Feature8MSecExt]))
4701         return MCDisassembler::Fail;
4702       break;
4703     default:
4704       // Architecturally defined as unpredictable
4705       S = MCDisassembler::SoftFail;
4706       break;
4707     }
4708 
4709     if (Inst.getOpcode() == ARM::t2MSR_M) {
4710       unsigned Mask = fieldFromInstruction(Val, 10, 2);
4711       if (!(FeatureBits[ARM::HasV7Ops])) {
4712         // The ARMv6-M MSR bits {11-10} can be only 0b10, other values are
4713         // unpredictable.
4714         if (Mask != 2)
4715           S = MCDisassembler::SoftFail;
4716       }
4717       else {
4718         // The ARMv7-M architecture stores an additional 2-bit mask value in
4719         // MSR bits {11-10}. The mask is used only with apsr, iapsr, eapsr and
4720         // xpsr, it has to be 0b10 in other cases. Bit mask{1} indicates if
4721         // the NZCVQ bits should be moved by the instruction. Bit mask{0}
4722         // indicates the move for the GE{3:0} bits, the mask{0} bit can be set
4723         // only if the processor includes the DSP extension.
4724         if (Mask == 0 || (Mask != 2 && ValLow > 3) ||
4725             (!(FeatureBits[ARM::FeatureDSP]) && (Mask & 1)))
4726           S = MCDisassembler::SoftFail;
4727       }
4728     }
4729   } else {
4730     // A/R class
4731     if (Val == 0)
4732       return MCDisassembler::Fail;
4733   }
4734   Inst.addOperand(MCOperand::createImm(Val));
4735   return S;
4736 }
4737 
4738 static DecodeStatus DecodeBankedReg(MCInst &Inst, unsigned Val,
4739                                     uint64_t Address, const void *Decoder) {
4740   unsigned R = fieldFromInstruction(Val, 5, 1);
4741   unsigned SysM = fieldFromInstruction(Val, 0, 5);
4742 
4743   // The table of encodings for these banked registers comes from B9.2.3 of the
4744   // ARM ARM. There are patterns, but nothing regular enough to make this logic
4745   // neater. So by fiat, these values are UNPREDICTABLE:
4746   if (!ARMBankedReg::lookupBankedRegByEncoding((R << 5) | SysM))
4747     return MCDisassembler::Fail;
4748 
4749   Inst.addOperand(MCOperand::createImm(Val));
4750   return MCDisassembler::Success;
4751 }
4752 
4753 static DecodeStatus DecodeDoubleRegLoad(MCInst &Inst, unsigned Insn,
4754                                         uint64_t Address, const void *Decoder) {
4755   DecodeStatus S = MCDisassembler::Success;
4756 
4757   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4758   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4759   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4760 
4761   if (Rn == 0xF)
4762     S = MCDisassembler::SoftFail;
4763 
4764   if (!Check(S, DecodeGPRPairRegisterClass(Inst, Rt, Address, Decoder)))
4765     return MCDisassembler::Fail;
4766   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4767     return MCDisassembler::Fail;
4768   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4769     return MCDisassembler::Fail;
4770 
4771   return S;
4772 }
4773 
4774 static DecodeStatus DecodeDoubleRegStore(MCInst &Inst, unsigned Insn,
4775                                          uint64_t Address,
4776                                          const void *Decoder) {
4777   DecodeStatus S = MCDisassembler::Success;
4778 
4779   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4780   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
4781   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4782   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4783 
4784   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
4785     return MCDisassembler::Fail;
4786 
4787   if (Rn == 0xF || Rd == Rn || Rd == Rt || Rd == Rt+1)
4788     S = MCDisassembler::SoftFail;
4789 
4790   if (!Check(S, DecodeGPRPairRegisterClass(Inst, Rt, Address, Decoder)))
4791     return MCDisassembler::Fail;
4792   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4793     return MCDisassembler::Fail;
4794   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4795     return MCDisassembler::Fail;
4796 
4797   return S;
4798 }
4799 
4800 static DecodeStatus DecodeLDRPreImm(MCInst &Inst, unsigned Insn,
4801                             uint64_t Address, const void *Decoder) {
4802   DecodeStatus S = MCDisassembler::Success;
4803 
4804   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4805   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4806   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4807   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4808   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4809   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4810 
4811   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4812 
4813   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4814     return MCDisassembler::Fail;
4815   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4816     return MCDisassembler::Fail;
4817   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
4818     return MCDisassembler::Fail;
4819   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4820     return MCDisassembler::Fail;
4821 
4822   return S;
4823 }
4824 
4825 static DecodeStatus DecodeLDRPreReg(MCInst &Inst, unsigned Insn,
4826                             uint64_t Address, const void *Decoder) {
4827   DecodeStatus S = MCDisassembler::Success;
4828 
4829   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4830   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4831   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4832   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4833   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4834   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4835   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4836 
4837   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4838   if (Rm == 0xF) S = MCDisassembler::SoftFail;
4839 
4840   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4841     return MCDisassembler::Fail;
4842   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4843     return MCDisassembler::Fail;
4844   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
4845     return MCDisassembler::Fail;
4846   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4847     return MCDisassembler::Fail;
4848 
4849   return S;
4850 }
4851 
4852 static DecodeStatus DecodeSTRPreImm(MCInst &Inst, unsigned Insn,
4853                             uint64_t Address, const void *Decoder) {
4854   DecodeStatus S = MCDisassembler::Success;
4855 
4856   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4857   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4858   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4859   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4860   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4861   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4862 
4863   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4864 
4865   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4866     return MCDisassembler::Fail;
4867   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4868     return MCDisassembler::Fail;
4869   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
4870     return MCDisassembler::Fail;
4871   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4872     return MCDisassembler::Fail;
4873 
4874   return S;
4875 }
4876 
4877 static DecodeStatus DecodeSTRPreReg(MCInst &Inst, unsigned Insn,
4878                             uint64_t Address, const void *Decoder) {
4879   DecodeStatus S = MCDisassembler::Success;
4880 
4881   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4882   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4883   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4884   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4885   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4886   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4887 
4888   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4889 
4890   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4891     return MCDisassembler::Fail;
4892   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4893     return MCDisassembler::Fail;
4894   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
4895     return MCDisassembler::Fail;
4896   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4897     return MCDisassembler::Fail;
4898 
4899   return S;
4900 }
4901 
4902 static DecodeStatus DecodeVLD1LN(MCInst &Inst, unsigned Insn,
4903                          uint64_t Address, const void *Decoder) {
4904   DecodeStatus S = MCDisassembler::Success;
4905 
4906   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4907   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4908   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4909   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4910   unsigned size = fieldFromInstruction(Insn, 10, 2);
4911 
4912   unsigned align = 0;
4913   unsigned index = 0;
4914   switch (size) {
4915     default:
4916       return MCDisassembler::Fail;
4917     case 0:
4918       if (fieldFromInstruction(Insn, 4, 1))
4919         return MCDisassembler::Fail; // UNDEFINED
4920       index = fieldFromInstruction(Insn, 5, 3);
4921       break;
4922     case 1:
4923       if (fieldFromInstruction(Insn, 5, 1))
4924         return MCDisassembler::Fail; // UNDEFINED
4925       index = fieldFromInstruction(Insn, 6, 2);
4926       if (fieldFromInstruction(Insn, 4, 1))
4927         align = 2;
4928       break;
4929     case 2:
4930       if (fieldFromInstruction(Insn, 6, 1))
4931         return MCDisassembler::Fail; // UNDEFINED
4932       index = fieldFromInstruction(Insn, 7, 1);
4933 
4934       switch (fieldFromInstruction(Insn, 4, 2)) {
4935         case 0 :
4936           align = 0; break;
4937         case 3:
4938           align = 4; break;
4939         default:
4940           return MCDisassembler::Fail;
4941       }
4942       break;
4943   }
4944 
4945   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4946     return MCDisassembler::Fail;
4947   if (Rm != 0xF) { // Writeback
4948     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4949       return MCDisassembler::Fail;
4950   }
4951   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4952     return MCDisassembler::Fail;
4953   Inst.addOperand(MCOperand::createImm(align));
4954   if (Rm != 0xF) {
4955     if (Rm != 0xD) {
4956       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4957         return MCDisassembler::Fail;
4958     } else
4959       Inst.addOperand(MCOperand::createReg(0));
4960   }
4961 
4962   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4963     return MCDisassembler::Fail;
4964   Inst.addOperand(MCOperand::createImm(index));
4965 
4966   return S;
4967 }
4968 
4969 static DecodeStatus DecodeVST1LN(MCInst &Inst, unsigned Insn,
4970                          uint64_t Address, const void *Decoder) {
4971   DecodeStatus S = MCDisassembler::Success;
4972 
4973   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4974   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4975   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4976   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4977   unsigned size = fieldFromInstruction(Insn, 10, 2);
4978 
4979   unsigned align = 0;
4980   unsigned index = 0;
4981   switch (size) {
4982     default:
4983       return MCDisassembler::Fail;
4984     case 0:
4985       if (fieldFromInstruction(Insn, 4, 1))
4986         return MCDisassembler::Fail; // UNDEFINED
4987       index = fieldFromInstruction(Insn, 5, 3);
4988       break;
4989     case 1:
4990       if (fieldFromInstruction(Insn, 5, 1))
4991         return MCDisassembler::Fail; // UNDEFINED
4992       index = fieldFromInstruction(Insn, 6, 2);
4993       if (fieldFromInstruction(Insn, 4, 1))
4994         align = 2;
4995       break;
4996     case 2:
4997       if (fieldFromInstruction(Insn, 6, 1))
4998         return MCDisassembler::Fail; // UNDEFINED
4999       index = fieldFromInstruction(Insn, 7, 1);
5000 
5001       switch (fieldFromInstruction(Insn, 4, 2)) {
5002         case 0:
5003           align = 0; break;
5004         case 3:
5005           align = 4; break;
5006         default:
5007           return MCDisassembler::Fail;
5008       }
5009       break;
5010   }
5011 
5012   if (Rm != 0xF) { // Writeback
5013     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5014     return MCDisassembler::Fail;
5015   }
5016   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5017     return MCDisassembler::Fail;
5018   Inst.addOperand(MCOperand::createImm(align));
5019   if (Rm != 0xF) {
5020     if (Rm != 0xD) {
5021       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5022     return MCDisassembler::Fail;
5023     } else
5024       Inst.addOperand(MCOperand::createReg(0));
5025   }
5026 
5027   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5028     return MCDisassembler::Fail;
5029   Inst.addOperand(MCOperand::createImm(index));
5030 
5031   return S;
5032 }
5033 
5034 static DecodeStatus DecodeVLD2LN(MCInst &Inst, unsigned Insn,
5035                          uint64_t Address, const void *Decoder) {
5036   DecodeStatus S = MCDisassembler::Success;
5037 
5038   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5039   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5040   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5041   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5042   unsigned size = fieldFromInstruction(Insn, 10, 2);
5043 
5044   unsigned align = 0;
5045   unsigned index = 0;
5046   unsigned inc = 1;
5047   switch (size) {
5048     default:
5049       return MCDisassembler::Fail;
5050     case 0:
5051       index = fieldFromInstruction(Insn, 5, 3);
5052       if (fieldFromInstruction(Insn, 4, 1))
5053         align = 2;
5054       break;
5055     case 1:
5056       index = fieldFromInstruction(Insn, 6, 2);
5057       if (fieldFromInstruction(Insn, 4, 1))
5058         align = 4;
5059       if (fieldFromInstruction(Insn, 5, 1))
5060         inc = 2;
5061       break;
5062     case 2:
5063       if (fieldFromInstruction(Insn, 5, 1))
5064         return MCDisassembler::Fail; // UNDEFINED
5065       index = fieldFromInstruction(Insn, 7, 1);
5066       if (fieldFromInstruction(Insn, 4, 1) != 0)
5067         align = 8;
5068       if (fieldFromInstruction(Insn, 6, 1))
5069         inc = 2;
5070       break;
5071   }
5072 
5073   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5074     return MCDisassembler::Fail;
5075   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5076     return MCDisassembler::Fail;
5077   if (Rm != 0xF) { // Writeback
5078     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5079       return MCDisassembler::Fail;
5080   }
5081   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5082     return MCDisassembler::Fail;
5083   Inst.addOperand(MCOperand::createImm(align));
5084   if (Rm != 0xF) {
5085     if (Rm != 0xD) {
5086       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5087         return MCDisassembler::Fail;
5088     } else
5089       Inst.addOperand(MCOperand::createReg(0));
5090   }
5091 
5092   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5093     return MCDisassembler::Fail;
5094   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5095     return MCDisassembler::Fail;
5096   Inst.addOperand(MCOperand::createImm(index));
5097 
5098   return S;
5099 }
5100 
5101 static DecodeStatus DecodeVST2LN(MCInst &Inst, unsigned Insn,
5102                          uint64_t Address, const void *Decoder) {
5103   DecodeStatus S = MCDisassembler::Success;
5104 
5105   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5106   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5107   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5108   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5109   unsigned size = fieldFromInstruction(Insn, 10, 2);
5110 
5111   unsigned align = 0;
5112   unsigned index = 0;
5113   unsigned inc = 1;
5114   switch (size) {
5115     default:
5116       return MCDisassembler::Fail;
5117     case 0:
5118       index = fieldFromInstruction(Insn, 5, 3);
5119       if (fieldFromInstruction(Insn, 4, 1))
5120         align = 2;
5121       break;
5122     case 1:
5123       index = fieldFromInstruction(Insn, 6, 2);
5124       if (fieldFromInstruction(Insn, 4, 1))
5125         align = 4;
5126       if (fieldFromInstruction(Insn, 5, 1))
5127         inc = 2;
5128       break;
5129     case 2:
5130       if (fieldFromInstruction(Insn, 5, 1))
5131         return MCDisassembler::Fail; // UNDEFINED
5132       index = fieldFromInstruction(Insn, 7, 1);
5133       if (fieldFromInstruction(Insn, 4, 1) != 0)
5134         align = 8;
5135       if (fieldFromInstruction(Insn, 6, 1))
5136         inc = 2;
5137       break;
5138   }
5139 
5140   if (Rm != 0xF) { // Writeback
5141     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5142       return MCDisassembler::Fail;
5143   }
5144   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5145     return MCDisassembler::Fail;
5146   Inst.addOperand(MCOperand::createImm(align));
5147   if (Rm != 0xF) {
5148     if (Rm != 0xD) {
5149       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5150         return MCDisassembler::Fail;
5151     } else
5152       Inst.addOperand(MCOperand::createReg(0));
5153   }
5154 
5155   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5156     return MCDisassembler::Fail;
5157   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5158     return MCDisassembler::Fail;
5159   Inst.addOperand(MCOperand::createImm(index));
5160 
5161   return S;
5162 }
5163 
5164 static DecodeStatus DecodeVLD3LN(MCInst &Inst, unsigned Insn,
5165                          uint64_t Address, const void *Decoder) {
5166   DecodeStatus S = MCDisassembler::Success;
5167 
5168   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5169   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5170   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5171   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5172   unsigned size = fieldFromInstruction(Insn, 10, 2);
5173 
5174   unsigned align = 0;
5175   unsigned index = 0;
5176   unsigned inc = 1;
5177   switch (size) {
5178     default:
5179       return MCDisassembler::Fail;
5180     case 0:
5181       if (fieldFromInstruction(Insn, 4, 1))
5182         return MCDisassembler::Fail; // UNDEFINED
5183       index = fieldFromInstruction(Insn, 5, 3);
5184       break;
5185     case 1:
5186       if (fieldFromInstruction(Insn, 4, 1))
5187         return MCDisassembler::Fail; // UNDEFINED
5188       index = fieldFromInstruction(Insn, 6, 2);
5189       if (fieldFromInstruction(Insn, 5, 1))
5190         inc = 2;
5191       break;
5192     case 2:
5193       if (fieldFromInstruction(Insn, 4, 2))
5194         return MCDisassembler::Fail; // UNDEFINED
5195       index = fieldFromInstruction(Insn, 7, 1);
5196       if (fieldFromInstruction(Insn, 6, 1))
5197         inc = 2;
5198       break;
5199   }
5200 
5201   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5202     return MCDisassembler::Fail;
5203   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5204     return MCDisassembler::Fail;
5205   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5206     return MCDisassembler::Fail;
5207 
5208   if (Rm != 0xF) { // Writeback
5209     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5210     return MCDisassembler::Fail;
5211   }
5212   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5213     return MCDisassembler::Fail;
5214   Inst.addOperand(MCOperand::createImm(align));
5215   if (Rm != 0xF) {
5216     if (Rm != 0xD) {
5217       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5218     return MCDisassembler::Fail;
5219     } else
5220       Inst.addOperand(MCOperand::createReg(0));
5221   }
5222 
5223   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5224     return MCDisassembler::Fail;
5225   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5226     return MCDisassembler::Fail;
5227   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5228     return MCDisassembler::Fail;
5229   Inst.addOperand(MCOperand::createImm(index));
5230 
5231   return S;
5232 }
5233 
5234 static DecodeStatus DecodeVST3LN(MCInst &Inst, unsigned Insn,
5235                          uint64_t Address, const void *Decoder) {
5236   DecodeStatus S = MCDisassembler::Success;
5237 
5238   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5239   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5240   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5241   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5242   unsigned size = fieldFromInstruction(Insn, 10, 2);
5243 
5244   unsigned align = 0;
5245   unsigned index = 0;
5246   unsigned inc = 1;
5247   switch (size) {
5248     default:
5249       return MCDisassembler::Fail;
5250     case 0:
5251       if (fieldFromInstruction(Insn, 4, 1))
5252         return MCDisassembler::Fail; // UNDEFINED
5253       index = fieldFromInstruction(Insn, 5, 3);
5254       break;
5255     case 1:
5256       if (fieldFromInstruction(Insn, 4, 1))
5257         return MCDisassembler::Fail; // UNDEFINED
5258       index = fieldFromInstruction(Insn, 6, 2);
5259       if (fieldFromInstruction(Insn, 5, 1))
5260         inc = 2;
5261       break;
5262     case 2:
5263       if (fieldFromInstruction(Insn, 4, 2))
5264         return MCDisassembler::Fail; // UNDEFINED
5265       index = fieldFromInstruction(Insn, 7, 1);
5266       if (fieldFromInstruction(Insn, 6, 1))
5267         inc = 2;
5268       break;
5269   }
5270 
5271   if (Rm != 0xF) { // Writeback
5272     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5273     return MCDisassembler::Fail;
5274   }
5275   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5276     return MCDisassembler::Fail;
5277   Inst.addOperand(MCOperand::createImm(align));
5278   if (Rm != 0xF) {
5279     if (Rm != 0xD) {
5280       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5281     return MCDisassembler::Fail;
5282     } else
5283       Inst.addOperand(MCOperand::createReg(0));
5284   }
5285 
5286   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5287     return MCDisassembler::Fail;
5288   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5289     return MCDisassembler::Fail;
5290   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5291     return MCDisassembler::Fail;
5292   Inst.addOperand(MCOperand::createImm(index));
5293 
5294   return S;
5295 }
5296 
5297 static DecodeStatus DecodeVLD4LN(MCInst &Inst, unsigned Insn,
5298                          uint64_t Address, const void *Decoder) {
5299   DecodeStatus S = MCDisassembler::Success;
5300 
5301   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5302   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5303   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5304   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5305   unsigned size = fieldFromInstruction(Insn, 10, 2);
5306 
5307   unsigned align = 0;
5308   unsigned index = 0;
5309   unsigned inc = 1;
5310   switch (size) {
5311     default:
5312       return MCDisassembler::Fail;
5313     case 0:
5314       if (fieldFromInstruction(Insn, 4, 1))
5315         align = 4;
5316       index = fieldFromInstruction(Insn, 5, 3);
5317       break;
5318     case 1:
5319       if (fieldFromInstruction(Insn, 4, 1))
5320         align = 8;
5321       index = fieldFromInstruction(Insn, 6, 2);
5322       if (fieldFromInstruction(Insn, 5, 1))
5323         inc = 2;
5324       break;
5325     case 2:
5326       switch (fieldFromInstruction(Insn, 4, 2)) {
5327         case 0:
5328           align = 0; break;
5329         case 3:
5330           return MCDisassembler::Fail;
5331         default:
5332           align = 4 << fieldFromInstruction(Insn, 4, 2); break;
5333       }
5334 
5335       index = fieldFromInstruction(Insn, 7, 1);
5336       if (fieldFromInstruction(Insn, 6, 1))
5337         inc = 2;
5338       break;
5339   }
5340 
5341   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5342     return MCDisassembler::Fail;
5343   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5344     return MCDisassembler::Fail;
5345   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5346     return MCDisassembler::Fail;
5347   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5348     return MCDisassembler::Fail;
5349 
5350   if (Rm != 0xF) { // Writeback
5351     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5352       return MCDisassembler::Fail;
5353   }
5354   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5355     return MCDisassembler::Fail;
5356   Inst.addOperand(MCOperand::createImm(align));
5357   if (Rm != 0xF) {
5358     if (Rm != 0xD) {
5359       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5360         return MCDisassembler::Fail;
5361     } else
5362       Inst.addOperand(MCOperand::createReg(0));
5363   }
5364 
5365   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5366     return MCDisassembler::Fail;
5367   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5368     return MCDisassembler::Fail;
5369   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5370     return MCDisassembler::Fail;
5371   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5372     return MCDisassembler::Fail;
5373   Inst.addOperand(MCOperand::createImm(index));
5374 
5375   return S;
5376 }
5377 
5378 static DecodeStatus DecodeVST4LN(MCInst &Inst, unsigned Insn,
5379                          uint64_t Address, const void *Decoder) {
5380   DecodeStatus S = MCDisassembler::Success;
5381 
5382   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5383   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5384   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5385   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5386   unsigned size = fieldFromInstruction(Insn, 10, 2);
5387 
5388   unsigned align = 0;
5389   unsigned index = 0;
5390   unsigned inc = 1;
5391   switch (size) {
5392     default:
5393       return MCDisassembler::Fail;
5394     case 0:
5395       if (fieldFromInstruction(Insn, 4, 1))
5396         align = 4;
5397       index = fieldFromInstruction(Insn, 5, 3);
5398       break;
5399     case 1:
5400       if (fieldFromInstruction(Insn, 4, 1))
5401         align = 8;
5402       index = fieldFromInstruction(Insn, 6, 2);
5403       if (fieldFromInstruction(Insn, 5, 1))
5404         inc = 2;
5405       break;
5406     case 2:
5407       switch (fieldFromInstruction(Insn, 4, 2)) {
5408         case 0:
5409           align = 0; break;
5410         case 3:
5411           return MCDisassembler::Fail;
5412         default:
5413           align = 4 << fieldFromInstruction(Insn, 4, 2); break;
5414       }
5415 
5416       index = fieldFromInstruction(Insn, 7, 1);
5417       if (fieldFromInstruction(Insn, 6, 1))
5418         inc = 2;
5419       break;
5420   }
5421 
5422   if (Rm != 0xF) { // Writeback
5423     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5424     return MCDisassembler::Fail;
5425   }
5426   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5427     return MCDisassembler::Fail;
5428   Inst.addOperand(MCOperand::createImm(align));
5429   if (Rm != 0xF) {
5430     if (Rm != 0xD) {
5431       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5432     return MCDisassembler::Fail;
5433     } else
5434       Inst.addOperand(MCOperand::createReg(0));
5435   }
5436 
5437   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5438     return MCDisassembler::Fail;
5439   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5440     return MCDisassembler::Fail;
5441   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5442     return MCDisassembler::Fail;
5443   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5444     return MCDisassembler::Fail;
5445   Inst.addOperand(MCOperand::createImm(index));
5446 
5447   return S;
5448 }
5449 
5450 static DecodeStatus DecodeVMOVSRR(MCInst &Inst, unsigned Insn,
5451                                   uint64_t Address, const void *Decoder) {
5452   DecodeStatus S = MCDisassembler::Success;
5453   unsigned Rt  = fieldFromInstruction(Insn, 12, 4);
5454   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
5455   unsigned Rm  = fieldFromInstruction(Insn,  5, 1);
5456   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5457   Rm |= fieldFromInstruction(Insn, 0, 4) << 1;
5458 
5459   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
5460     S = MCDisassembler::SoftFail;
5461 
5462   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
5463     return MCDisassembler::Fail;
5464   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
5465     return MCDisassembler::Fail;
5466   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
5467     return MCDisassembler::Fail;
5468   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
5469     return MCDisassembler::Fail;
5470   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5471     return MCDisassembler::Fail;
5472 
5473   return S;
5474 }
5475 
5476 static DecodeStatus DecodeVMOVRRS(MCInst &Inst, unsigned Insn,
5477                                   uint64_t Address, const void *Decoder) {
5478   DecodeStatus S = MCDisassembler::Success;
5479   unsigned Rt  = fieldFromInstruction(Insn, 12, 4);
5480   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
5481   unsigned Rm  = fieldFromInstruction(Insn,  5, 1);
5482   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5483   Rm |= fieldFromInstruction(Insn, 0, 4) << 1;
5484 
5485   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
5486     S = MCDisassembler::SoftFail;
5487 
5488   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
5489     return MCDisassembler::Fail;
5490   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
5491     return MCDisassembler::Fail;
5492   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
5493     return MCDisassembler::Fail;
5494   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
5495     return MCDisassembler::Fail;
5496   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5497     return MCDisassembler::Fail;
5498 
5499   return S;
5500 }
5501 
5502 static DecodeStatus DecodeIT(MCInst &Inst, unsigned Insn,
5503                              uint64_t Address, const void *Decoder) {
5504   DecodeStatus S = MCDisassembler::Success;
5505   unsigned pred = fieldFromInstruction(Insn, 4, 4);
5506   unsigned mask = fieldFromInstruction(Insn, 0, 4);
5507 
5508   if (pred == 0xF) {
5509     pred = 0xE;
5510     S = MCDisassembler::SoftFail;
5511   }
5512 
5513   if (mask == 0x0)
5514     return MCDisassembler::Fail;
5515 
5516   // IT masks are encoded as a sequence of replacement low-order bits
5517   // for the condition code. So if the low bit of the starting
5518   // condition code is 1, then we have to flip all the bits above the
5519   // terminating bit (which is the lowest 1 bit).
5520   if (pred & 1) {
5521     unsigned LowBit = mask & -mask;
5522     unsigned BitsAboveLowBit = 0xF & (-LowBit << 1);
5523     mask ^= BitsAboveLowBit;
5524   }
5525 
5526   Inst.addOperand(MCOperand::createImm(pred));
5527   Inst.addOperand(MCOperand::createImm(mask));
5528   return S;
5529 }
5530 
5531 static DecodeStatus
5532 DecodeT2LDRDPreInstruction(MCInst &Inst, unsigned Insn,
5533                            uint64_t Address, const void *Decoder) {
5534   DecodeStatus S = MCDisassembler::Success;
5535 
5536   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5537   unsigned Rt2 = fieldFromInstruction(Insn, 8, 4);
5538   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5539   unsigned addr = fieldFromInstruction(Insn, 0, 8);
5540   unsigned W = fieldFromInstruction(Insn, 21, 1);
5541   unsigned U = fieldFromInstruction(Insn, 23, 1);
5542   unsigned P = fieldFromInstruction(Insn, 24, 1);
5543   bool writeback = (W == 1) | (P == 0);
5544 
5545   addr |= (U << 8) | (Rn << 9);
5546 
5547   if (writeback && (Rn == Rt || Rn == Rt2))
5548     Check(S, MCDisassembler::SoftFail);
5549   if (Rt == Rt2)
5550     Check(S, MCDisassembler::SoftFail);
5551 
5552   // Rt
5553   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
5554     return MCDisassembler::Fail;
5555   // Rt2
5556   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
5557     return MCDisassembler::Fail;
5558   // Writeback operand
5559   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
5560     return MCDisassembler::Fail;
5561   // addr
5562   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
5563     return MCDisassembler::Fail;
5564 
5565   return S;
5566 }
5567 
5568 static DecodeStatus
5569 DecodeT2STRDPreInstruction(MCInst &Inst, unsigned Insn,
5570                            uint64_t Address, const void *Decoder) {
5571   DecodeStatus S = MCDisassembler::Success;
5572 
5573   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5574   unsigned Rt2 = fieldFromInstruction(Insn, 8, 4);
5575   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5576   unsigned addr = fieldFromInstruction(Insn, 0, 8);
5577   unsigned W = fieldFromInstruction(Insn, 21, 1);
5578   unsigned U = fieldFromInstruction(Insn, 23, 1);
5579   unsigned P = fieldFromInstruction(Insn, 24, 1);
5580   bool writeback = (W == 1) | (P == 0);
5581 
5582   addr |= (U << 8) | (Rn << 9);
5583 
5584   if (writeback && (Rn == Rt || Rn == Rt2))
5585     Check(S, MCDisassembler::SoftFail);
5586 
5587   // Writeback operand
5588   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
5589     return MCDisassembler::Fail;
5590   // Rt
5591   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
5592     return MCDisassembler::Fail;
5593   // Rt2
5594   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
5595     return MCDisassembler::Fail;
5596   // addr
5597   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
5598     return MCDisassembler::Fail;
5599 
5600   return S;
5601 }
5602 
5603 static DecodeStatus DecodeT2Adr(MCInst &Inst, uint32_t Insn,
5604                                 uint64_t Address, const void *Decoder) {
5605   unsigned sign1 = fieldFromInstruction(Insn, 21, 1);
5606   unsigned sign2 = fieldFromInstruction(Insn, 23, 1);
5607   if (sign1 != sign2) return MCDisassembler::Fail;
5608   const unsigned Rd = fieldFromInstruction(Insn, 8, 4);
5609   assert(Inst.getNumOperands() == 0 && "We should receive an empty Inst");
5610   DecodeStatus S = DecoderGPRRegisterClass(Inst, Rd, Address, Decoder);
5611 
5612   unsigned Val = fieldFromInstruction(Insn, 0, 8);
5613   Val |= fieldFromInstruction(Insn, 12, 3) << 8;
5614   Val |= fieldFromInstruction(Insn, 26, 1) << 11;
5615   // If sign, then it is decreasing the address.
5616   if (sign1) {
5617     // Following ARMv7 Architecture Manual, when the offset
5618     // is zero, it is decoded as a subw, not as a adr.w
5619     if (!Val) {
5620       Inst.setOpcode(ARM::t2SUBri12);
5621       Inst.addOperand(MCOperand::createReg(ARM::PC));
5622     } else
5623       Val = -Val;
5624   }
5625   Inst.addOperand(MCOperand::createImm(Val));
5626   return S;
5627 }
5628 
5629 static DecodeStatus DecodeT2ShifterImmOperand(MCInst &Inst, uint32_t Val,
5630                                               uint64_t Address,
5631                                               const void *Decoder) {
5632   DecodeStatus S = MCDisassembler::Success;
5633 
5634   // Shift of "asr #32" is not allowed in Thumb2 mode.
5635   if (Val == 0x20) S = MCDisassembler::Fail;
5636   Inst.addOperand(MCOperand::createImm(Val));
5637   return S;
5638 }
5639 
5640 static DecodeStatus DecodeSwap(MCInst &Inst, unsigned Insn,
5641                                uint64_t Address, const void *Decoder) {
5642   unsigned Rt   = fieldFromInstruction(Insn, 12, 4);
5643   unsigned Rt2  = fieldFromInstruction(Insn, 0,  4);
5644   unsigned Rn   = fieldFromInstruction(Insn, 16, 4);
5645   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5646 
5647   if (pred == 0xF)
5648     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
5649 
5650   DecodeStatus S = MCDisassembler::Success;
5651 
5652   if (Rt == Rn || Rn == Rt2)
5653     S = MCDisassembler::SoftFail;
5654 
5655   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5656     return MCDisassembler::Fail;
5657   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5658     return MCDisassembler::Fail;
5659   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
5660     return MCDisassembler::Fail;
5661   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5662     return MCDisassembler::Fail;
5663 
5664   return S;
5665 }
5666 
5667 static DecodeStatus DecodeVCVTD(MCInst &Inst, unsigned Insn,
5668                                 uint64_t Address, const void *Decoder) {
5669   const FeatureBitset &featureBits =
5670       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5671   bool hasFullFP16 = featureBits[ARM::FeatureFullFP16];
5672 
5673   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5674   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5675   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5676   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5677   unsigned imm = fieldFromInstruction(Insn, 16, 6);
5678   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
5679   unsigned op = fieldFromInstruction(Insn, 5, 1);
5680 
5681   DecodeStatus S = MCDisassembler::Success;
5682 
5683   // If the top 3 bits of imm are clear, this is a VMOV (immediate)
5684   if (!(imm & 0x38)) {
5685     if (cmode == 0xF) {
5686       if (op == 1) return MCDisassembler::Fail;
5687       Inst.setOpcode(ARM::VMOVv2f32);
5688     }
5689     if (hasFullFP16) {
5690       if (cmode == 0xE) {
5691         if (op == 1) {
5692           Inst.setOpcode(ARM::VMOVv1i64);
5693         } else {
5694           Inst.setOpcode(ARM::VMOVv8i8);
5695         }
5696       }
5697       if (cmode == 0xD) {
5698         if (op == 1) {
5699           Inst.setOpcode(ARM::VMVNv2i32);
5700         } else {
5701           Inst.setOpcode(ARM::VMOVv2i32);
5702         }
5703       }
5704       if (cmode == 0xC) {
5705         if (op == 1) {
5706           Inst.setOpcode(ARM::VMVNv2i32);
5707         } else {
5708           Inst.setOpcode(ARM::VMOVv2i32);
5709         }
5710       }
5711     }
5712     return DecodeVMOVModImmInstruction(Inst, Insn, Address, Decoder);
5713   }
5714 
5715   if (!(imm & 0x20)) return MCDisassembler::Fail;
5716 
5717   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
5718     return MCDisassembler::Fail;
5719   if (!Check(S, DecodeDPRRegisterClass(Inst, Vm, Address, Decoder)))
5720     return MCDisassembler::Fail;
5721   Inst.addOperand(MCOperand::createImm(64 - imm));
5722 
5723   return S;
5724 }
5725 
5726 static DecodeStatus DecodeVCVTQ(MCInst &Inst, unsigned Insn,
5727                                 uint64_t Address, const void *Decoder) {
5728   const FeatureBitset &featureBits =
5729       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5730   bool hasFullFP16 = featureBits[ARM::FeatureFullFP16];
5731 
5732   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5733   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5734   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5735   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5736   unsigned imm = fieldFromInstruction(Insn, 16, 6);
5737   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
5738   unsigned op = fieldFromInstruction(Insn, 5, 1);
5739 
5740   DecodeStatus S = MCDisassembler::Success;
5741 
5742   // If the top 3 bits of imm are clear, this is a VMOV (immediate)
5743   if (!(imm & 0x38)) {
5744     if (cmode == 0xF) {
5745       if (op == 1) return MCDisassembler::Fail;
5746       Inst.setOpcode(ARM::VMOVv4f32);
5747     }
5748     if (hasFullFP16) {
5749       if (cmode == 0xE) {
5750         if (op == 1) {
5751           Inst.setOpcode(ARM::VMOVv2i64);
5752         } else {
5753           Inst.setOpcode(ARM::VMOVv16i8);
5754         }
5755       }
5756       if (cmode == 0xD) {
5757         if (op == 1) {
5758           Inst.setOpcode(ARM::VMVNv4i32);
5759         } else {
5760           Inst.setOpcode(ARM::VMOVv4i32);
5761         }
5762       }
5763       if (cmode == 0xC) {
5764         if (op == 1) {
5765           Inst.setOpcode(ARM::VMVNv4i32);
5766         } else {
5767           Inst.setOpcode(ARM::VMOVv4i32);
5768         }
5769       }
5770     }
5771     return DecodeVMOVModImmInstruction(Inst, Insn, Address, Decoder);
5772   }
5773 
5774   if (!(imm & 0x20)) return MCDisassembler::Fail;
5775 
5776   if (!Check(S, DecodeQPRRegisterClass(Inst, Vd, Address, Decoder)))
5777     return MCDisassembler::Fail;
5778   if (!Check(S, DecodeQPRRegisterClass(Inst, Vm, Address, Decoder)))
5779     return MCDisassembler::Fail;
5780   Inst.addOperand(MCOperand::createImm(64 - imm));
5781 
5782   return S;
5783 }
5784 
5785 static DecodeStatus DecodeNEONComplexLane64Instruction(MCInst &Inst,
5786                                                        unsigned Insn,
5787                                                        uint64_t Address,
5788                                                        const void *Decoder) {
5789   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5790   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5791   unsigned Vn = (fieldFromInstruction(Insn, 16, 4) << 0);
5792   Vn |= (fieldFromInstruction(Insn, 7, 1) << 4);
5793   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5794   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5795   unsigned q = (fieldFromInstruction(Insn, 6, 1) << 0);
5796   unsigned rotate = (fieldFromInstruction(Insn, 20, 2) << 0);
5797 
5798   DecodeStatus S = MCDisassembler::Success;
5799 
5800   auto DestRegDecoder = q ? DecodeQPRRegisterClass : DecodeDPRRegisterClass;
5801 
5802   if (!Check(S, DestRegDecoder(Inst, Vd, Address, Decoder)))
5803     return MCDisassembler::Fail;
5804   if (!Check(S, DestRegDecoder(Inst, Vd, Address, Decoder)))
5805     return MCDisassembler::Fail;
5806   if (!Check(S, DestRegDecoder(Inst, Vn, Address, Decoder)))
5807     return MCDisassembler::Fail;
5808   if (!Check(S, DecodeDPRRegisterClass(Inst, Vm, Address, Decoder)))
5809     return MCDisassembler::Fail;
5810   // The lane index does not have any bits in the encoding, because it can only
5811   // be 0.
5812   Inst.addOperand(MCOperand::createImm(0));
5813   Inst.addOperand(MCOperand::createImm(rotate));
5814 
5815   return S;
5816 }
5817 
5818 static DecodeStatus DecodeLDR(MCInst &Inst, unsigned Val,
5819                                 uint64_t Address, const void *Decoder) {
5820   DecodeStatus S = MCDisassembler::Success;
5821 
5822   unsigned Rn = fieldFromInstruction(Val, 16, 4);
5823   unsigned Rt = fieldFromInstruction(Val, 12, 4);
5824   unsigned Rm = fieldFromInstruction(Val, 0, 4);
5825   Rm |= (fieldFromInstruction(Val, 23, 1) << 4);
5826   unsigned Cond = fieldFromInstruction(Val, 28, 4);
5827 
5828   if (fieldFromInstruction(Val, 8, 4) != 0 || Rn == Rt)
5829     S = MCDisassembler::SoftFail;
5830 
5831   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5832     return MCDisassembler::Fail;
5833   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
5834     return MCDisassembler::Fail;
5835   if (!Check(S, DecodeAddrMode7Operand(Inst, Rn, Address, Decoder)))
5836     return MCDisassembler::Fail;
5837   if (!Check(S, DecodePostIdxReg(Inst, Rm, Address, Decoder)))
5838     return MCDisassembler::Fail;
5839   if (!Check(S, DecodePredicateOperand(Inst, Cond, Address, Decoder)))
5840     return MCDisassembler::Fail;
5841 
5842   return S;
5843 }
5844 
5845 static DecodeStatus DecoderForMRRC2AndMCRR2(MCInst &Inst, unsigned Val,
5846                                             uint64_t Address, const void *Decoder) {
5847   DecodeStatus S = MCDisassembler::Success;
5848 
5849   unsigned CRm = fieldFromInstruction(Val, 0, 4);
5850   unsigned opc1 = fieldFromInstruction(Val, 4, 4);
5851   unsigned cop = fieldFromInstruction(Val, 8, 4);
5852   unsigned Rt = fieldFromInstruction(Val, 12, 4);
5853   unsigned Rt2 = fieldFromInstruction(Val, 16, 4);
5854 
5855   if ((cop & ~0x1) == 0xa)
5856     return MCDisassembler::Fail;
5857 
5858   if (Rt == Rt2)
5859     S = MCDisassembler::SoftFail;
5860 
5861   // We have to check if the instruction is MRRC2
5862   // or MCRR2 when constructing the operands for
5863   // Inst. Reason is because MRRC2 stores to two
5864   // registers so it's tablegen desc has has two
5865   // outputs whereas MCRR doesn't store to any
5866   // registers so all of it's operands are listed
5867   // as inputs, therefore the operand order for
5868   // MRRC2 needs to be [Rt, Rt2, cop, opc1, CRm]
5869   // and MCRR2 operand order is [cop, opc1, Rt, Rt2, CRm]
5870 
5871   if (Inst.getOpcode() == ARM::MRRC2) {
5872     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5873       return MCDisassembler::Fail;
5874     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5875       return MCDisassembler::Fail;
5876   }
5877   Inst.addOperand(MCOperand::createImm(cop));
5878   Inst.addOperand(MCOperand::createImm(opc1));
5879   if (Inst.getOpcode() == ARM::MCRR2) {
5880     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5881       return MCDisassembler::Fail;
5882     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5883       return MCDisassembler::Fail;
5884   }
5885   Inst.addOperand(MCOperand::createImm(CRm));
5886 
5887   return S;
5888 }
5889 
5890 static DecodeStatus DecodeForVMRSandVMSR(MCInst &Inst, unsigned Val,
5891                                          uint64_t Address,
5892                                          const void *Decoder) {
5893   const FeatureBitset &featureBits =
5894       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5895   DecodeStatus S = MCDisassembler::Success;
5896 
5897   // Add explicit operand for the destination sysreg, for cases where
5898   // we have to model it for code generation purposes.
5899   switch (Inst.getOpcode()) {
5900   case ARM::VMSR_FPSCR_NZCVQC:
5901     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
5902     break;
5903   case ARM::VMSR_P0:
5904     Inst.addOperand(MCOperand::createReg(ARM::VPR));
5905     break;
5906   }
5907 
5908   if (Inst.getOpcode() != ARM::FMSTAT) {
5909     unsigned Rt = fieldFromInstruction(Val, 12, 4);
5910 
5911     if (featureBits[ARM::ModeThumb] && !featureBits[ARM::HasV8Ops]) {
5912       if (Rt == 13 || Rt == 15)
5913         S = MCDisassembler::SoftFail;
5914       Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder));
5915     } else
5916       Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder));
5917   }
5918 
5919   // Add explicit operand for the source sysreg, similarly to above.
5920   switch (Inst.getOpcode()) {
5921   case ARM::VMRS_FPSCR_NZCVQC:
5922     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
5923     break;
5924   case ARM::VMRS_P0:
5925     Inst.addOperand(MCOperand::createReg(ARM::VPR));
5926     break;
5927   }
5928 
5929   if (featureBits[ARM::ModeThumb]) {
5930     Inst.addOperand(MCOperand::createImm(ARMCC::AL));
5931     Inst.addOperand(MCOperand::createReg(0));
5932   } else {
5933     unsigned pred = fieldFromInstruction(Val, 28, 4);
5934     if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5935       return MCDisassembler::Fail;
5936   }
5937 
5938   return S;
5939 }
5940 
5941 template <bool isSigned, bool isNeg, bool zeroPermitted, int size>
5942 static DecodeStatus DecodeBFLabelOperand(MCInst &Inst, unsigned Val,
5943                                          uint64_t Address,
5944                                          const void *Decoder) {
5945   DecodeStatus S = MCDisassembler::Success;
5946   if (Val == 0 && !zeroPermitted)
5947     S = MCDisassembler::Fail;
5948 
5949   uint64_t DecVal;
5950   if (isSigned)
5951     DecVal = SignExtend32<size + 1>(Val << 1);
5952   else
5953     DecVal = (Val << 1);
5954 
5955   if (!tryAddingSymbolicOperand(Address, Address + DecVal + 4, true, 4, Inst,
5956                                 Decoder))
5957     Inst.addOperand(MCOperand::createImm(isNeg ? -DecVal : DecVal));
5958   return S;
5959 }
5960 
5961 static DecodeStatus DecodeBFAfterTargetOperand(MCInst &Inst, unsigned Val,
5962                                                uint64_t Address,
5963                                                const void *Decoder) {
5964 
5965   uint64_t LocImm = Inst.getOperand(0).getImm();
5966   Val = LocImm + (2 << Val);
5967   if (!tryAddingSymbolicOperand(Address, Address + Val + 4, true, 4, Inst,
5968                                 Decoder))
5969     Inst.addOperand(MCOperand::createImm(Val));
5970   return MCDisassembler::Success;
5971 }
5972 
5973 static DecodeStatus DecodePredNoALOperand(MCInst &Inst, unsigned Val,
5974                                           uint64_t Address,
5975                                           const void *Decoder) {
5976   if (Val >= ARMCC::AL)  // also exclude the non-condition NV
5977     return MCDisassembler::Fail;
5978   Inst.addOperand(MCOperand::createImm(Val));
5979   return MCDisassembler::Success;
5980 }
5981 
5982 static DecodeStatus DecodeLOLoop(MCInst &Inst, unsigned Insn, uint64_t Address,
5983                                  const void *Decoder) {
5984   DecodeStatus S = MCDisassembler::Success;
5985 
5986   if (Inst.getOpcode() == ARM::MVE_LCTP)
5987     return S;
5988 
5989   unsigned Imm = fieldFromInstruction(Insn, 11, 1) |
5990                  fieldFromInstruction(Insn, 1, 10) << 1;
5991   switch (Inst.getOpcode()) {
5992   case ARM::t2LEUpdate:
5993   case ARM::MVE_LETP:
5994     Inst.addOperand(MCOperand::createReg(ARM::LR));
5995     Inst.addOperand(MCOperand::createReg(ARM::LR));
5996     LLVM_FALLTHROUGH;
5997   case ARM::t2LE:
5998     if (!Check(S, DecodeBFLabelOperand<false, true, true, 11>(
5999                    Inst, Imm, Address, Decoder)))
6000       return MCDisassembler::Fail;
6001     break;
6002   case ARM::t2WLS:
6003   case ARM::MVE_WLSTP_8:
6004   case ARM::MVE_WLSTP_16:
6005   case ARM::MVE_WLSTP_32:
6006   case ARM::MVE_WLSTP_64:
6007     Inst.addOperand(MCOperand::createReg(ARM::LR));
6008     if (!Check(S,
6009                DecoderGPRRegisterClass(Inst, fieldFromInstruction(Insn, 16, 4),
6010                                        Address, Decoder)) ||
6011         !Check(S, DecodeBFLabelOperand<false, false, true, 11>(
6012                    Inst, Imm, Address, Decoder)))
6013       return MCDisassembler::Fail;
6014     break;
6015   case ARM::t2DLS:
6016   case ARM::MVE_DLSTP_8:
6017   case ARM::MVE_DLSTP_16:
6018   case ARM::MVE_DLSTP_32:
6019   case ARM::MVE_DLSTP_64:
6020     unsigned Rn = fieldFromInstruction(Insn, 16, 4);
6021     if (Rn == 0xF) {
6022       // Enforce all the rest of the instruction bits in LCTP, which
6023       // won't have been reliably checked based on LCTP's own tablegen
6024       // record, because we came to this decode by a roundabout route.
6025       uint32_t CanonicalLCTP = 0xF00FE001, SBZMask = 0x00300FFE;
6026       if ((Insn & ~SBZMask) != CanonicalLCTP)
6027         return MCDisassembler::Fail;   // a mandatory bit is wrong: hard fail
6028       if (Insn != CanonicalLCTP)
6029         Check(S, MCDisassembler::SoftFail); // an SBZ bit is wrong: soft fail
6030 
6031       Inst.setOpcode(ARM::MVE_LCTP);
6032     } else {
6033       Inst.addOperand(MCOperand::createReg(ARM::LR));
6034       if (!Check(S, DecoderGPRRegisterClass(Inst,
6035                                             fieldFromInstruction(Insn, 16, 4),
6036                                             Address, Decoder)))
6037         return MCDisassembler::Fail;
6038     }
6039     break;
6040   }
6041   return S;
6042 }
6043 
6044 static DecodeStatus DecodeLongShiftOperand(MCInst &Inst, unsigned Val,
6045                                            uint64_t Address,
6046                                            const void *Decoder) {
6047   DecodeStatus S = MCDisassembler::Success;
6048 
6049   if (Val == 0)
6050     Val = 32;
6051 
6052   Inst.addOperand(MCOperand::createImm(Val));
6053 
6054   return S;
6055 }
6056 
6057 static DecodeStatus DecodetGPROddRegisterClass(MCInst &Inst, unsigned RegNo,
6058                                    uint64_t Address, const void *Decoder) {
6059   if ((RegNo) + 1 > 11)
6060     return MCDisassembler::Fail;
6061 
6062   unsigned Register = GPRDecoderTable[(RegNo) + 1];
6063   Inst.addOperand(MCOperand::createReg(Register));
6064   return MCDisassembler::Success;
6065 }
6066 
6067 static DecodeStatus DecodetGPREvenRegisterClass(MCInst &Inst, unsigned RegNo,
6068                                    uint64_t Address, const void *Decoder) {
6069   if ((RegNo) > 14)
6070     return MCDisassembler::Fail;
6071 
6072   unsigned Register = GPRDecoderTable[(RegNo)];
6073   Inst.addOperand(MCOperand::createReg(Register));
6074   return MCDisassembler::Success;
6075 }
6076 
6077 static DecodeStatus DecodeVSCCLRM(MCInst &Inst, unsigned Insn, uint64_t Address,
6078                                   const void *Decoder) {
6079   DecodeStatus S = MCDisassembler::Success;
6080 
6081   Inst.addOperand(MCOperand::createImm(ARMCC::AL));
6082   Inst.addOperand(MCOperand::createReg(0));
6083   if (Inst.getOpcode() == ARM::VSCCLRMD) {
6084     unsigned reglist = (fieldFromInstruction(Insn, 1, 7) << 1) |
6085                        (fieldFromInstruction(Insn, 12, 4) << 8) |
6086                        (fieldFromInstruction(Insn, 22, 1) << 12);
6087     if (!Check(S, DecodeDPRRegListOperand(Inst, reglist, Address, Decoder))) {
6088       return MCDisassembler::Fail;
6089     }
6090   } else {
6091     unsigned reglist = fieldFromInstruction(Insn, 0, 8) |
6092                        (fieldFromInstruction(Insn, 22, 1) << 8) |
6093                        (fieldFromInstruction(Insn, 12, 4) << 9);
6094     if (!Check(S, DecodeSPRRegListOperand(Inst, reglist, Address, Decoder))) {
6095       return MCDisassembler::Fail;
6096     }
6097   }
6098   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6099 
6100   return S;
6101 }
6102 
6103 static DecodeStatus DecodeMQPRRegisterClass(MCInst &Inst, unsigned RegNo,
6104                               uint64_t Address,
6105                               const void *Decoder) {
6106   if (RegNo > 7)
6107     return MCDisassembler::Fail;
6108 
6109   unsigned Register = QPRDecoderTable[RegNo];
6110   Inst.addOperand(MCOperand::createReg(Register));
6111   return MCDisassembler::Success;
6112 }
6113 
6114 static const uint16_t QQPRDecoderTable[] = {
6115      ARM::Q0_Q1,  ARM::Q1_Q2,  ARM::Q2_Q3,  ARM::Q3_Q4,
6116      ARM::Q4_Q5,  ARM::Q5_Q6,  ARM::Q6_Q7
6117 };
6118 
6119 static DecodeStatus DecodeQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
6120                               uint64_t Address,
6121                               const void *Decoder) {
6122   if (RegNo > 6)
6123     return MCDisassembler::Fail;
6124 
6125   unsigned Register = QQPRDecoderTable[RegNo];
6126   Inst.addOperand(MCOperand::createReg(Register));
6127   return MCDisassembler::Success;
6128 }
6129 
6130 static const uint16_t QQQQPRDecoderTable[] = {
6131      ARM::Q0_Q1_Q2_Q3,  ARM::Q1_Q2_Q3_Q4,  ARM::Q2_Q3_Q4_Q5,
6132      ARM::Q3_Q4_Q5_Q6,  ARM::Q4_Q5_Q6_Q7
6133 };
6134 
6135 static DecodeStatus DecodeQQQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
6136                               uint64_t Address,
6137                               const void *Decoder) {
6138   if (RegNo > 4)
6139     return MCDisassembler::Fail;
6140 
6141   unsigned Register = QQQQPRDecoderTable[RegNo];
6142   Inst.addOperand(MCOperand::createReg(Register));
6143   return MCDisassembler::Success;
6144 }
6145 
6146 static DecodeStatus DecodeVPTMaskOperand(MCInst &Inst, unsigned Val,
6147                                          uint64_t Address,
6148                                          const void *Decoder) {
6149   DecodeStatus S = MCDisassembler::Success;
6150 
6151   // Parse VPT mask and encode it in the MCInst as an immediate with the same
6152   // format as the it_mask.  That is, from the second 'e|t' encode 'e' as 1 and
6153   // 't' as 0 and finish with a 1.
6154   unsigned Imm = 0;
6155   // We always start with a 't'.
6156   unsigned CurBit = 0;
6157   for (int i = 3; i >= 0; --i) {
6158     // If the bit we are looking at is not the same as last one, invert the
6159     // CurBit, if it is the same leave it as is.
6160     CurBit ^= (Val >> i) & 1U;
6161 
6162     // Encode the CurBit at the right place in the immediate.
6163     Imm |= (CurBit << i);
6164 
6165     // If we are done, finish the encoding with a 1.
6166     if ((Val & ~(~0U << i)) == 0) {
6167       Imm |= 1U << i;
6168       break;
6169     }
6170   }
6171 
6172   Inst.addOperand(MCOperand::createImm(Imm));
6173 
6174   return S;
6175 }
6176 
6177 static DecodeStatus DecodeVpredROperand(MCInst &Inst, unsigned RegNo,
6178                                         uint64_t Address, const void *Decoder) {
6179   // The vpred_r operand type includes an MQPR register field derived
6180   // from the encoding. But we don't actually want to add an operand
6181   // to the MCInst at this stage, because AddThumbPredicate will do it
6182   // later, and will infer the register number from the TIED_TO
6183   // constraint. So this is a deliberately empty decoder method that
6184   // will inhibit the auto-generated disassembly code from adding an
6185   // operand at all.
6186   return MCDisassembler::Success;
6187 }
6188 
6189 static DecodeStatus DecodeRestrictedIPredicateOperand(MCInst &Inst,
6190                                                       unsigned Val,
6191                                                       uint64_t Address,
6192                                                       const void *Decoder) {
6193   Inst.addOperand(MCOperand::createImm((Val & 0x1) == 0 ? ARMCC::EQ : ARMCC::NE));
6194   return MCDisassembler::Success;
6195 }
6196 
6197 static DecodeStatus DecodeRestrictedSPredicateOperand(MCInst &Inst,
6198                                                       unsigned Val,
6199                                                       uint64_t Address,
6200                                                       const void *Decoder) {
6201   unsigned Code;
6202   switch (Val & 0x3) {
6203   case 0:
6204     Code = ARMCC::GE;
6205     break;
6206   case 1:
6207     Code = ARMCC::LT;
6208     break;
6209   case 2:
6210     Code = ARMCC::GT;
6211     break;
6212   case 3:
6213     Code = ARMCC::LE;
6214     break;
6215   }
6216   Inst.addOperand(MCOperand::createImm(Code));
6217   return MCDisassembler::Success;
6218 }
6219 
6220 static DecodeStatus DecodeRestrictedUPredicateOperand(MCInst &Inst,
6221                                                       unsigned Val,
6222                                                       uint64_t Address,
6223                                                       const void *Decoder) {
6224   Inst.addOperand(MCOperand::createImm((Val & 0x1) == 0 ? ARMCC::HS : ARMCC::HI));
6225   return MCDisassembler::Success;
6226 }
6227 
6228 static DecodeStatus DecodeRestrictedFPPredicateOperand(MCInst &Inst, unsigned Val,
6229                                                      uint64_t Address,
6230                                                      const void *Decoder) {
6231   unsigned Code;
6232   switch (Val) {
6233   default:
6234     return MCDisassembler::Fail;
6235   case 0:
6236     Code = ARMCC::EQ;
6237     break;
6238   case 1:
6239     Code = ARMCC::NE;
6240     break;
6241   case 4:
6242     Code = ARMCC::GE;
6243     break;
6244   case 5:
6245     Code = ARMCC::LT;
6246     break;
6247   case 6:
6248     Code = ARMCC::GT;
6249     break;
6250   case 7:
6251     Code = ARMCC::LE;
6252     break;
6253   }
6254 
6255   Inst.addOperand(MCOperand::createImm(Code));
6256   return MCDisassembler::Success;
6257 }
6258 
6259 static DecodeStatus DecodeVCVTImmOperand(MCInst &Inst, unsigned Val,
6260                                          uint64_t Address, const void *Decoder) {
6261   DecodeStatus S = MCDisassembler::Success;
6262 
6263   unsigned DecodedVal = 64 - Val;
6264 
6265   switch (Inst.getOpcode()) {
6266   case ARM::MVE_VCVTf16s16_fix:
6267   case ARM::MVE_VCVTs16f16_fix:
6268   case ARM::MVE_VCVTf16u16_fix:
6269   case ARM::MVE_VCVTu16f16_fix:
6270     if (DecodedVal > 16)
6271       return MCDisassembler::Fail;
6272     break;
6273   case ARM::MVE_VCVTf32s32_fix:
6274   case ARM::MVE_VCVTs32f32_fix:
6275   case ARM::MVE_VCVTf32u32_fix:
6276   case ARM::MVE_VCVTu32f32_fix:
6277     if (DecodedVal > 32)
6278       return MCDisassembler::Fail;
6279     break;
6280   }
6281 
6282   Inst.addOperand(MCOperand::createImm(64 - Val));
6283 
6284   return S;
6285 }
6286 
6287 static unsigned FixedRegForVSTRVLDR_SYSREG(unsigned Opcode) {
6288   switch (Opcode) {
6289   case ARM::VSTR_P0_off:
6290   case ARM::VSTR_P0_pre:
6291   case ARM::VSTR_P0_post:
6292   case ARM::VLDR_P0_off:
6293   case ARM::VLDR_P0_pre:
6294   case ARM::VLDR_P0_post:
6295     return ARM::P0;
6296   default:
6297     return 0;
6298   }
6299 }
6300 
6301 template<bool Writeback>
6302 static DecodeStatus DecodeVSTRVLDR_SYSREG(MCInst &Inst, unsigned Val,
6303                                           uint64_t Address,
6304                                           const void *Decoder) {
6305   switch (Inst.getOpcode()) {
6306   case ARM::VSTR_FPSCR_pre:
6307   case ARM::VSTR_FPSCR_NZCVQC_pre:
6308   case ARM::VLDR_FPSCR_pre:
6309   case ARM::VLDR_FPSCR_NZCVQC_pre:
6310   case ARM::VSTR_FPSCR_off:
6311   case ARM::VSTR_FPSCR_NZCVQC_off:
6312   case ARM::VLDR_FPSCR_off:
6313   case ARM::VLDR_FPSCR_NZCVQC_off:
6314   case ARM::VSTR_FPSCR_post:
6315   case ARM::VSTR_FPSCR_NZCVQC_post:
6316   case ARM::VLDR_FPSCR_post:
6317   case ARM::VLDR_FPSCR_NZCVQC_post:
6318     const FeatureBitset &featureBits =
6319         ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
6320 
6321     if (!featureBits[ARM::HasMVEIntegerOps] && !featureBits[ARM::FeatureVFP2])
6322       return MCDisassembler::Fail;
6323   }
6324 
6325   DecodeStatus S = MCDisassembler::Success;
6326   if (unsigned Sysreg = FixedRegForVSTRVLDR_SYSREG(Inst.getOpcode()))
6327     Inst.addOperand(MCOperand::createReg(Sysreg));
6328   unsigned Rn = fieldFromInstruction(Val, 16, 4);
6329   unsigned addr = fieldFromInstruction(Val, 0, 7) |
6330                   (fieldFromInstruction(Val, 23, 1) << 7) | (Rn << 8);
6331 
6332   if (Writeback) {
6333     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
6334       return MCDisassembler::Fail;
6335   }
6336   if (!Check(S, DecodeT2AddrModeImm7s4(Inst, addr, Address, Decoder)))
6337     return MCDisassembler::Fail;
6338 
6339   Inst.addOperand(MCOperand::createImm(ARMCC::AL));
6340   Inst.addOperand(MCOperand::createReg(0));
6341 
6342   return S;
6343 }
6344 
6345 static inline DecodeStatus DecodeMVE_MEM_pre(
6346   MCInst &Inst, unsigned Val, uint64_t Address, const void *Decoder,
6347   unsigned Rn, OperandDecoder RnDecoder, OperandDecoder AddrDecoder) {
6348   DecodeStatus S = MCDisassembler::Success;
6349 
6350   unsigned Qd = fieldFromInstruction(Val, 13, 3);
6351   unsigned addr = fieldFromInstruction(Val, 0, 7) |
6352                   (fieldFromInstruction(Val, 23, 1) << 7) | (Rn << 8);
6353 
6354   if (!Check(S, RnDecoder(Inst, Rn, Address, Decoder)))
6355     return MCDisassembler::Fail;
6356   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6357     return MCDisassembler::Fail;
6358   if (!Check(S, AddrDecoder(Inst, addr, Address, Decoder)))
6359     return MCDisassembler::Fail;
6360 
6361   return S;
6362 }
6363 
6364 template <int shift>
6365 static DecodeStatus DecodeMVE_MEM_1_pre(MCInst &Inst, unsigned Val,
6366                                         uint64_t Address, const void *Decoder) {
6367   return DecodeMVE_MEM_pre(Inst, Val, Address, Decoder,
6368                            fieldFromInstruction(Val, 16, 3),
6369                            DecodetGPRRegisterClass,
6370                            DecodeTAddrModeImm7<shift>);
6371 }
6372 
6373 template <int shift>
6374 static DecodeStatus DecodeMVE_MEM_2_pre(MCInst &Inst, unsigned Val,
6375                                         uint64_t Address, const void *Decoder) {
6376   return DecodeMVE_MEM_pre(Inst, Val, Address, Decoder,
6377                            fieldFromInstruction(Val, 16, 4),
6378                            DecoderGPRRegisterClass,
6379                            DecodeT2AddrModeImm7<shift,1>);
6380 }
6381 
6382 template <int shift>
6383 static DecodeStatus DecodeMVE_MEM_3_pre(MCInst &Inst, unsigned Val,
6384                                         uint64_t Address, const void *Decoder) {
6385   return DecodeMVE_MEM_pre(Inst, Val, Address, Decoder,
6386                            fieldFromInstruction(Val, 17, 3),
6387                            DecodeMQPRRegisterClass,
6388                            DecodeMveAddrModeQ<shift>);
6389 }
6390 
6391 template<unsigned MinLog, unsigned MaxLog>
6392 static DecodeStatus DecodePowerTwoOperand(MCInst &Inst, unsigned Val,
6393                                           uint64_t Address,
6394                                           const void *Decoder) {
6395   DecodeStatus S = MCDisassembler::Success;
6396 
6397   if (Val < MinLog || Val > MaxLog)
6398     return MCDisassembler::Fail;
6399 
6400   Inst.addOperand(MCOperand::createImm(1LL << Val));
6401   return S;
6402 }
6403 
6404 template <int shift>
6405 static DecodeStatus DecodeExpandedImmOperand(MCInst &Inst, unsigned Val,
6406                                              uint64_t Address,
6407                                              const void *Decoder) {
6408     Val <<= shift;
6409 
6410     Inst.addOperand(MCOperand::createImm(Val));
6411     return MCDisassembler::Success;
6412 }
6413 
6414 template<unsigned start>
6415 static DecodeStatus DecodeMVEPairVectorIndexOperand(MCInst &Inst, unsigned Val,
6416                                                     uint64_t Address,
6417                                                     const void *Decoder) {
6418   DecodeStatus S = MCDisassembler::Success;
6419 
6420   Inst.addOperand(MCOperand::createImm(start + Val));
6421 
6422   return S;
6423 }
6424 
6425 static DecodeStatus DecodeMVEVMOVQtoDReg(MCInst &Inst, unsigned Insn,
6426                                          uint64_t Address, const void *Decoder) {
6427   DecodeStatus S = MCDisassembler::Success;
6428   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
6429   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
6430   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
6431                  fieldFromInstruction(Insn, 13, 3));
6432   unsigned index = fieldFromInstruction(Insn, 4, 1);
6433 
6434   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
6435     return MCDisassembler::Fail;
6436   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2, Address, Decoder)))
6437     return MCDisassembler::Fail;
6438   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6439     return MCDisassembler::Fail;
6440   if (!Check(S, DecodeMVEPairVectorIndexOperand<2>(Inst, index, Address, Decoder)))
6441     return MCDisassembler::Fail;
6442   if (!Check(S, DecodeMVEPairVectorIndexOperand<0>(Inst, index, Address, Decoder)))
6443     return MCDisassembler::Fail;
6444 
6445   return S;
6446 }
6447 
6448 static DecodeStatus DecodeMVEVMOVDRegtoQ(MCInst &Inst, unsigned Insn,
6449                                          uint64_t Address, const void *Decoder) {
6450   DecodeStatus S = MCDisassembler::Success;
6451   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
6452   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
6453   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
6454                  fieldFromInstruction(Insn, 13, 3));
6455   unsigned index = fieldFromInstruction(Insn, 4, 1);
6456 
6457   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6458     return MCDisassembler::Fail;
6459   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6460     return MCDisassembler::Fail;
6461   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
6462     return MCDisassembler::Fail;
6463   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2, Address, Decoder)))
6464     return MCDisassembler::Fail;
6465   if (!Check(S, DecodeMVEPairVectorIndexOperand<2>(Inst, index, Address, Decoder)))
6466     return MCDisassembler::Fail;
6467   if (!Check(S, DecodeMVEPairVectorIndexOperand<0>(Inst, index, Address, Decoder)))
6468     return MCDisassembler::Fail;
6469 
6470   return S;
6471 }
6472 
6473 static DecodeStatus DecodeMVEOverlappingLongShift(
6474   MCInst &Inst, unsigned Insn, uint64_t Address, const void *Decoder) {
6475   DecodeStatus S = MCDisassembler::Success;
6476 
6477   unsigned RdaLo = fieldFromInstruction(Insn, 17, 3) << 1;
6478   unsigned RdaHi = fieldFromInstruction(Insn, 9, 3) << 1;
6479   unsigned Rm = fieldFromInstruction(Insn, 12, 4);
6480 
6481   if (RdaHi == 14) {
6482     // This value of RdaHi (really indicating pc, because RdaHi has to
6483     // be an odd-numbered register, so the low bit will be set by the
6484     // decode function below) indicates that we must decode as SQRSHR
6485     // or UQRSHL, which both have a single Rda register field with all
6486     // four bits.
6487     unsigned Rda = fieldFromInstruction(Insn, 16, 4);
6488 
6489     switch (Inst.getOpcode()) {
6490       case ARM::MVE_ASRLr:
6491       case ARM::MVE_SQRSHRL:
6492         Inst.setOpcode(ARM::MVE_SQRSHR);
6493         break;
6494       case ARM::MVE_LSLLr:
6495       case ARM::MVE_UQRSHLL:
6496         Inst.setOpcode(ARM::MVE_UQRSHL);
6497         break;
6498       default:
6499         llvm_unreachable("Unexpected starting opcode!");
6500     }
6501 
6502     // Rda as output parameter
6503     if (!Check(S, DecoderGPRRegisterClass(Inst, Rda, Address, Decoder)))
6504       return MCDisassembler::Fail;
6505 
6506     // Rda again as input parameter
6507     if (!Check(S, DecoderGPRRegisterClass(Inst, Rda, Address, Decoder)))
6508       return MCDisassembler::Fail;
6509 
6510     // Rm, the amount to shift by
6511     if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
6512       return MCDisassembler::Fail;
6513 
6514     if (fieldFromInstruction (Insn, 6, 3) != 4)
6515       return MCDisassembler::SoftFail;
6516 
6517     if (Rda == Rm)
6518       return MCDisassembler::SoftFail;
6519 
6520     return S;
6521   }
6522 
6523   // Otherwise, we decode as whichever opcode our caller has already
6524   // put into Inst. Those all look the same:
6525 
6526   // RdaLo,RdaHi as output parameters
6527   if (!Check(S, DecodetGPREvenRegisterClass(Inst, RdaLo, Address, Decoder)))
6528     return MCDisassembler::Fail;
6529   if (!Check(S, DecodetGPROddRegisterClass(Inst, RdaHi, Address, Decoder)))
6530     return MCDisassembler::Fail;
6531 
6532   // RdaLo,RdaHi again as input parameters
6533   if (!Check(S, DecodetGPREvenRegisterClass(Inst, RdaLo, Address, Decoder)))
6534     return MCDisassembler::Fail;
6535   if (!Check(S, DecodetGPROddRegisterClass(Inst, RdaHi, Address, Decoder)))
6536     return MCDisassembler::Fail;
6537 
6538   // Rm, the amount to shift by
6539   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
6540     return MCDisassembler::Fail;
6541 
6542   if (Inst.getOpcode() == ARM::MVE_SQRSHRL ||
6543       Inst.getOpcode() == ARM::MVE_UQRSHLL) {
6544     unsigned Saturate = fieldFromInstruction(Insn, 7, 1);
6545     // Saturate, the bit position for saturation
6546     Inst.addOperand(MCOperand::createImm(Saturate));
6547   }
6548 
6549   return S;
6550 }
6551 
6552 static DecodeStatus DecodeMVEVCVTt1fp(MCInst &Inst, unsigned Insn, uint64_t Address,
6553                                       const void *Decoder) {
6554   DecodeStatus S = MCDisassembler::Success;
6555   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
6556                  fieldFromInstruction(Insn, 13, 3));
6557   unsigned Qm = ((fieldFromInstruction(Insn, 5, 1) << 3) |
6558                  fieldFromInstruction(Insn, 1, 3));
6559   unsigned imm6 = fieldFromInstruction(Insn, 16, 6);
6560 
6561   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6562     return MCDisassembler::Fail;
6563   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
6564     return MCDisassembler::Fail;
6565   if (!Check(S, DecodeVCVTImmOperand(Inst, imm6, Address, Decoder)))
6566     return MCDisassembler::Fail;
6567 
6568   return S;
6569 }
6570 
6571 template<bool scalar, OperandDecoder predicate_decoder>
6572 static DecodeStatus DecodeMVEVCMP(MCInst &Inst, unsigned Insn, uint64_t Address,
6573                                   const void *Decoder) {
6574   DecodeStatus S = MCDisassembler::Success;
6575   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6576   unsigned Qn = fieldFromInstruction(Insn, 17, 3);
6577   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qn, Address, Decoder)))
6578     return MCDisassembler::Fail;
6579 
6580   unsigned fc;
6581 
6582   if (scalar) {
6583     fc = fieldFromInstruction(Insn, 12, 1) << 2 |
6584          fieldFromInstruction(Insn, 7, 1) |
6585          fieldFromInstruction(Insn, 5, 1) << 1;
6586     unsigned Rm = fieldFromInstruction(Insn, 0, 4);
6587     if (!Check(S, DecodeGPRwithZRRegisterClass(Inst, Rm, Address, Decoder)))
6588       return MCDisassembler::Fail;
6589   } else {
6590     fc = fieldFromInstruction(Insn, 12, 1) << 2 |
6591          fieldFromInstruction(Insn, 7, 1) |
6592          fieldFromInstruction(Insn, 0, 1) << 1;
6593     unsigned Qm = fieldFromInstruction(Insn, 5, 1) << 4 |
6594                   fieldFromInstruction(Insn, 1, 3);
6595     if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
6596       return MCDisassembler::Fail;
6597   }
6598 
6599   if (!Check(S, predicate_decoder(Inst, fc, Address, Decoder)))
6600     return MCDisassembler::Fail;
6601 
6602   Inst.addOperand(MCOperand::createImm(ARMVCC::None));
6603   Inst.addOperand(MCOperand::createReg(0));
6604   Inst.addOperand(MCOperand::createImm(0));
6605 
6606   return S;
6607 }
6608 
6609 static DecodeStatus DecodeMveVCTP(MCInst &Inst, unsigned Insn, uint64_t Address,
6610                                   const void *Decoder) {
6611   DecodeStatus S = MCDisassembler::Success;
6612   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6613   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
6614   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
6615     return MCDisassembler::Fail;
6616   return S;
6617 }
6618 
6619 static DecodeStatus DecodeMVEVPNOT(MCInst &Inst, unsigned Insn, uint64_t Address,
6620                                    const void *Decoder) {
6621   DecodeStatus S = MCDisassembler::Success;
6622   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6623   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6624   return S;
6625 }
6626 
6627 static DecodeStatus DecodeT2AddSubSPImm(MCInst &Inst, unsigned Insn,
6628                                         uint64_t Address, const void *Decoder) {
6629   const unsigned Rd = fieldFromInstruction(Insn, 8, 4);
6630   const unsigned Rn = fieldFromInstruction(Insn, 16, 4);
6631   const unsigned Imm12 = fieldFromInstruction(Insn, 26, 1) << 11 |
6632                          fieldFromInstruction(Insn, 12, 3) << 8 |
6633                          fieldFromInstruction(Insn, 0, 8);
6634   const unsigned TypeT3 = fieldFromInstruction(Insn, 25, 1);
6635   unsigned sign1 = fieldFromInstruction(Insn, 21, 1);
6636   unsigned sign2 = fieldFromInstruction(Insn, 23, 1);
6637   unsigned S = fieldFromInstruction(Insn, 20, 1);
6638   if (sign1 != sign2)
6639     return MCDisassembler::Fail;
6640 
6641   // T3 does a zext of imm12, where T2 does a ThumbExpandImm (T2SOImm)
6642   DecodeStatus DS = MCDisassembler::Success;
6643   if ((!Check(DS,
6644               DecodeGPRspRegisterClass(Inst, Rd, Address, Decoder))) || // dst
6645       (!Check(DS, DecodeGPRspRegisterClass(Inst, Rn, Address, Decoder))))
6646     return MCDisassembler::Fail;
6647   if (TypeT3) {
6648     Inst.setOpcode(sign1 ? ARM::t2SUBspImm12 : ARM::t2ADDspImm12);
6649     S = 0;
6650     Inst.addOperand(MCOperand::createImm(Imm12)); // zext imm12
6651   } else {
6652     Inst.setOpcode(sign1 ? ARM::t2SUBspImm : ARM::t2ADDspImm);
6653     if (!Check(DS, DecodeT2SOImm(Inst, Imm12, Address, Decoder))) // imm12
6654       return MCDisassembler::Fail;
6655   }
6656   if (!Check(DS, DecodeCCOutOperand(Inst, S, Address, Decoder))) // cc_out
6657     return MCDisassembler::Fail;
6658 
6659   Inst.addOperand(MCOperand::createReg(0)); // pred
6660 
6661   return DS;
6662 }
6663