1 //===-- ARMDisassembler.cpp - Disassembler for ARM/Thumb ISA --------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "MCTargetDesc/ARMAddressingModes.h"
11 #include "MCTargetDesc/ARMBaseInfo.h"
12 #include "MCTargetDesc/ARMMCTargetDesc.h"
13 #include "llvm/MC/MCContext.h"
14 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
15 #include "llvm/MC/MCFixedLenDisassembler.h"
16 #include "llvm/MC/MCInst.h"
17 #include "llvm/MC/MCInstrDesc.h"
18 #include "llvm/MC/MCSubtargetInfo.h"
19 #include "llvm/MC/SubtargetFeature.h"
20 #include "llvm/Support/Compiler.h"
21 #include "llvm/Support/ErrorHandling.h"
22 #include "llvm/Support/MathExtras.h"
23 #include "llvm/Support/raw_ostream.h"
24 #include "llvm/Support/TargetRegistry.h"
25 #include <algorithm>
26 #include <cassert>
27 #include <cstdint>
28 #include <vector>
29 
30 using namespace llvm;
31 
32 #define DEBUG_TYPE "arm-disassembler"
33 
34 typedef MCDisassembler::DecodeStatus DecodeStatus;
35 
36 namespace {
37 
38   // Handles the condition code status of instructions in IT blocks
39   class ITStatus
40   {
41     public:
42       // Returns the condition code for instruction in IT block
43       unsigned getITCC() {
44         unsigned CC = ARMCC::AL;
45         if (instrInITBlock())
46           CC = ITStates.back();
47         return CC;
48       }
49 
50       // Advances the IT block state to the next T or E
51       void advanceITState() {
52         ITStates.pop_back();
53       }
54 
55       // Returns true if the current instruction is in an IT block
56       bool instrInITBlock() {
57         return !ITStates.empty();
58       }
59 
60       // Returns true if current instruction is the last instruction in an IT block
61       bool instrLastInITBlock() {
62         return ITStates.size() == 1;
63       }
64 
65       // Called when decoding an IT instruction. Sets the IT state for the following
66       // instructions that for the IT block. Firstcond and Mask correspond to the
67       // fields in the IT instruction encoding.
68       void setITState(char Firstcond, char Mask) {
69         // (3 - the number of trailing zeros) is the number of then / else.
70         unsigned CondBit0 = Firstcond & 1;
71         unsigned NumTZ = countTrailingZeros<uint8_t>(Mask);
72         unsigned char CCBits = static_cast<unsigned char>(Firstcond & 0xf);
73         assert(NumTZ <= 3 && "Invalid IT mask!");
74         // push condition codes onto the stack the correct order for the pops
75         for (unsigned Pos = NumTZ+1; Pos <= 3; ++Pos) {
76           bool T = ((Mask >> Pos) & 1) == CondBit0;
77           if (T)
78             ITStates.push_back(CCBits);
79           else
80             ITStates.push_back(CCBits ^ 1);
81         }
82         ITStates.push_back(CCBits);
83       }
84 
85     private:
86       std::vector<unsigned char> ITStates;
87   };
88 
89 /// ARM disassembler for all ARM platforms.
90 class ARMDisassembler : public MCDisassembler {
91 public:
92   ARMDisassembler(const MCSubtargetInfo &STI, MCContext &Ctx) :
93     MCDisassembler(STI, Ctx) {
94   }
95 
96   ~ARMDisassembler() override = default;
97 
98   DecodeStatus getInstruction(MCInst &Instr, uint64_t &Size,
99                               ArrayRef<uint8_t> Bytes, uint64_t Address,
100                               raw_ostream &VStream,
101                               raw_ostream &CStream) const override;
102 };
103 
104 /// Thumb disassembler for all Thumb platforms.
105 class ThumbDisassembler : public MCDisassembler {
106 public:
107   ThumbDisassembler(const MCSubtargetInfo &STI, MCContext &Ctx) :
108     MCDisassembler(STI, Ctx) {
109   }
110 
111   ~ThumbDisassembler() override = default;
112 
113   DecodeStatus getInstruction(MCInst &Instr, uint64_t &Size,
114                               ArrayRef<uint8_t> Bytes, uint64_t Address,
115                               raw_ostream &VStream,
116                               raw_ostream &CStream) const override;
117 
118 private:
119   mutable ITStatus ITBlock;
120   DecodeStatus AddThumbPredicate(MCInst&) const;
121   void UpdateThumbVFPPredicate(MCInst&) const;
122 };
123 
124 } // end anonymous namespace
125 
126 static bool Check(DecodeStatus &Out, DecodeStatus In) {
127   switch (In) {
128     case MCDisassembler::Success:
129       // Out stays the same.
130       return true;
131     case MCDisassembler::SoftFail:
132       Out = In;
133       return true;
134     case MCDisassembler::Fail:
135       Out = In;
136       return false;
137   }
138   llvm_unreachable("Invalid DecodeStatus!");
139 }
140 
141 // Forward declare these because the autogenerated code will reference them.
142 // Definitions are further down.
143 static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, unsigned RegNo,
144                                    uint64_t Address, const void *Decoder);
145 static DecodeStatus DecodeGPRnopcRegisterClass(MCInst &Inst,
146                                                unsigned RegNo, uint64_t Address,
147                                                const void *Decoder);
148 static DecodeStatus DecodeGPRwithAPSRRegisterClass(MCInst &Inst,
149                                                unsigned RegNo, uint64_t Address,
150                                                const void *Decoder);
151 static DecodeStatus DecodetGPRRegisterClass(MCInst &Inst, unsigned RegNo,
152                                    uint64_t Address, const void *Decoder);
153 static DecodeStatus DecodetcGPRRegisterClass(MCInst &Inst, unsigned RegNo,
154                                    uint64_t Address, const void *Decoder);
155 static DecodeStatus DecoderGPRRegisterClass(MCInst &Inst, unsigned RegNo,
156                                    uint64_t Address, const void *Decoder);
157 static DecodeStatus DecodeGPRPairRegisterClass(MCInst &Inst, unsigned RegNo,
158                                    uint64_t Address, const void *Decoder);
159 static DecodeStatus DecodeSPRRegisterClass(MCInst &Inst, unsigned RegNo,
160                                    uint64_t Address, const void *Decoder);
161 static DecodeStatus DecodeDPRRegisterClass(MCInst &Inst, unsigned RegNo,
162                                    uint64_t Address, const void *Decoder);
163 static DecodeStatus DecodeDPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
164                                    uint64_t Address, const void *Decoder);
165 static DecodeStatus DecodeDPR_VFP2RegisterClass(MCInst &Inst,
166                                                 unsigned RegNo,
167                                                 uint64_t Address,
168                                                 const void *Decoder);
169 static DecodeStatus DecodeQPRRegisterClass(MCInst &Inst, unsigned RegNo,
170                                    uint64_t Address, const void *Decoder);
171 static DecodeStatus DecodeDPairRegisterClass(MCInst &Inst, unsigned RegNo,
172                                    uint64_t Address, const void *Decoder);
173 static DecodeStatus DecodeDPairSpacedRegisterClass(MCInst &Inst,
174                                unsigned RegNo, uint64_t Address,
175                                const void *Decoder);
176 
177 static DecodeStatus DecodePredicateOperand(MCInst &Inst, unsigned Val,
178                                uint64_t Address, const void *Decoder);
179 static DecodeStatus DecodeCCOutOperand(MCInst &Inst, unsigned Val,
180                                uint64_t Address, const void *Decoder);
181 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Val,
182                                uint64_t Address, const void *Decoder);
183 static DecodeStatus DecodeSPRRegListOperand(MCInst &Inst, unsigned Val,
184                                uint64_t Address, const void *Decoder);
185 static DecodeStatus DecodeDPRRegListOperand(MCInst &Inst, unsigned Val,
186                                uint64_t Address, const void *Decoder);
187 
188 static DecodeStatus DecodeBitfieldMaskOperand(MCInst &Inst, unsigned Insn,
189                                uint64_t Address, const void *Decoder);
190 static DecodeStatus DecodeCopMemInstruction(MCInst &Inst, unsigned Insn,
191                                uint64_t Address, const void *Decoder);
192 static DecodeStatus DecodeAddrMode2IdxInstruction(MCInst &Inst,
193                                                   unsigned Insn,
194                                                   uint64_t Address,
195                                                   const void *Decoder);
196 static DecodeStatus DecodeSORegMemOperand(MCInst &Inst, unsigned Insn,
197                                uint64_t Address, const void *Decoder);
198 static DecodeStatus DecodeAddrMode3Instruction(MCInst &Inst,unsigned Insn,
199                                uint64_t Address, const void *Decoder);
200 static DecodeStatus DecodeSORegImmOperand(MCInst &Inst, unsigned Insn,
201                                uint64_t Address, const void *Decoder);
202 static DecodeStatus DecodeSORegRegOperand(MCInst &Inst, unsigned Insn,
203                                uint64_t Address, const void *Decoder);
204 
205 static DecodeStatus DecodeMemMultipleWritebackInstruction(MCInst & Inst,
206                                                   unsigned Insn,
207                                                   uint64_t Adddress,
208                                                   const void *Decoder);
209 static DecodeStatus DecodeT2MOVTWInstruction(MCInst &Inst, unsigned Insn,
210                                uint64_t Address, const void *Decoder);
211 static DecodeStatus DecodeArmMOVTWInstruction(MCInst &Inst, unsigned Insn,
212                                uint64_t Address, const void *Decoder);
213 static DecodeStatus DecodeSMLAInstruction(MCInst &Inst, unsigned Insn,
214                                uint64_t Address, const void *Decoder);
215 static DecodeStatus DecodeHINTInstruction(MCInst &Inst, unsigned Insn,
216                                uint64_t Address, const void *Decoder);
217 static DecodeStatus DecodeCPSInstruction(MCInst &Inst, unsigned Insn,
218                                uint64_t Address, const void *Decoder);
219 static DecodeStatus DecodeTSTInstruction(MCInst &Inst, unsigned Insn,
220                                uint64_t Address, const void *Decoder);
221 static DecodeStatus DecodeSETPANInstruction(MCInst &Inst, unsigned Insn,
222                                uint64_t Address, const void *Decoder);
223 static DecodeStatus DecodeT2CPSInstruction(MCInst &Inst, unsigned Insn,
224                                uint64_t Address, const void *Decoder);
225 static DecodeStatus DecodeAddrModeImm12Operand(MCInst &Inst, unsigned Val,
226                                uint64_t Address, const void *Decoder);
227 static DecodeStatus DecodeAddrMode5Operand(MCInst &Inst, unsigned Val,
228                                uint64_t Address, const void *Decoder);
229 static DecodeStatus DecodeAddrMode5FP16Operand(MCInst &Inst, unsigned Val,
230                                uint64_t Address, const void *Decoder);
231 static DecodeStatus DecodeAddrMode7Operand(MCInst &Inst, unsigned Val,
232                                uint64_t Address, const void *Decoder);
233 static DecodeStatus DecodeT2BInstruction(MCInst &Inst, unsigned Insn,
234                                uint64_t Address, const void *Decoder);
235 static DecodeStatus DecodeBranchImmInstruction(MCInst &Inst,unsigned Insn,
236                                uint64_t Address, const void *Decoder);
237 static DecodeStatus DecodeAddrMode6Operand(MCInst &Inst, unsigned Val,
238                                uint64_t Address, const void *Decoder);
239 static DecodeStatus DecodeVLDST1Instruction(MCInst &Inst, unsigned Val,
240                                uint64_t Address, const void *Decoder);
241 static DecodeStatus DecodeVLDST2Instruction(MCInst &Inst, unsigned Val,
242                                uint64_t Address, const void *Decoder);
243 static DecodeStatus DecodeVLDST3Instruction(MCInst &Inst, unsigned Val,
244                                uint64_t Address, const void *Decoder);
245 static DecodeStatus DecodeVLDST4Instruction(MCInst &Inst, unsigned Val,
246                                uint64_t Address, const void *Decoder);
247 static DecodeStatus DecodeVLDInstruction(MCInst &Inst, unsigned Val,
248                                uint64_t Address, const void *Decoder);
249 static DecodeStatus DecodeVSTInstruction(MCInst &Inst, unsigned Val,
250                                uint64_t Address, const void *Decoder);
251 static DecodeStatus DecodeVLD1DupInstruction(MCInst &Inst, unsigned Val,
252                                uint64_t Address, const void *Decoder);
253 static DecodeStatus DecodeVLD2DupInstruction(MCInst &Inst, unsigned Val,
254                                uint64_t Address, const void *Decoder);
255 static DecodeStatus DecodeVLD3DupInstruction(MCInst &Inst, unsigned Val,
256                                uint64_t Address, const void *Decoder);
257 static DecodeStatus DecodeVLD4DupInstruction(MCInst &Inst, unsigned Val,
258                                uint64_t Address, const void *Decoder);
259 static DecodeStatus DecodeNEONModImmInstruction(MCInst &Inst,unsigned Val,
260                                uint64_t Address, const void *Decoder);
261 static DecodeStatus DecodeVSHLMaxInstruction(MCInst &Inst, unsigned Val,
262                                uint64_t Address, const void *Decoder);
263 static DecodeStatus DecodeShiftRight8Imm(MCInst &Inst, unsigned Val,
264                                uint64_t Address, const void *Decoder);
265 static DecodeStatus DecodeShiftRight16Imm(MCInst &Inst, unsigned Val,
266                                uint64_t Address, const void *Decoder);
267 static DecodeStatus DecodeShiftRight32Imm(MCInst &Inst, unsigned Val,
268                                uint64_t Address, const void *Decoder);
269 static DecodeStatus DecodeShiftRight64Imm(MCInst &Inst, unsigned Val,
270                                uint64_t Address, const void *Decoder);
271 static DecodeStatus DecodeTBLInstruction(MCInst &Inst, unsigned Insn,
272                                uint64_t Address, const void *Decoder);
273 static DecodeStatus DecodePostIdxReg(MCInst &Inst, unsigned Insn,
274                                uint64_t Address, const void *Decoder);
275 static DecodeStatus DecodeCoprocessor(MCInst &Inst, unsigned Insn,
276                                uint64_t Address, const void *Decoder);
277 static DecodeStatus DecodeMemBarrierOption(MCInst &Inst, unsigned Insn,
278                                uint64_t Address, const void *Decoder);
279 static DecodeStatus DecodeInstSyncBarrierOption(MCInst &Inst, unsigned Insn,
280                                uint64_t Address, const void *Decoder);
281 static DecodeStatus DecodeMSRMask(MCInst &Inst, unsigned Insn,
282                                uint64_t Address, const void *Decoder);
283 static DecodeStatus DecodeBankedReg(MCInst &Inst, unsigned Insn,
284                                uint64_t Address, const void *Decoder);
285 static DecodeStatus DecodeDoubleRegLoad(MCInst &Inst, unsigned Insn,
286                                uint64_t Address, const void *Decoder);
287 static DecodeStatus DecodeDoubleRegStore(MCInst &Inst, unsigned Insn,
288                                uint64_t Address, const void *Decoder);
289 static DecodeStatus DecodeLDRPreImm(MCInst &Inst, unsigned Insn,
290                                uint64_t Address, const void *Decoder);
291 static DecodeStatus DecodeLDRPreReg(MCInst &Inst, unsigned Insn,
292                                uint64_t Address, const void *Decoder);
293 static DecodeStatus DecodeSTRPreImm(MCInst &Inst, unsigned Insn,
294                                uint64_t Address, const void *Decoder);
295 static DecodeStatus DecodeSTRPreReg(MCInst &Inst, unsigned Insn,
296                                uint64_t Address, const void *Decoder);
297 static DecodeStatus DecodeVLD1LN(MCInst &Inst, unsigned Insn,
298                                uint64_t Address, const void *Decoder);
299 static DecodeStatus DecodeVLD2LN(MCInst &Inst, unsigned Insn,
300                                uint64_t Address, const void *Decoder);
301 static DecodeStatus DecodeVLD3LN(MCInst &Inst, unsigned Insn,
302                                uint64_t Address, const void *Decoder);
303 static DecodeStatus DecodeVLD4LN(MCInst &Inst, unsigned Insn,
304                                uint64_t Address, const void *Decoder);
305 static DecodeStatus DecodeVST1LN(MCInst &Inst, unsigned Insn,
306                                uint64_t Address, const void *Decoder);
307 static DecodeStatus DecodeVST2LN(MCInst &Inst, unsigned Insn,
308                                uint64_t Address, const void *Decoder);
309 static DecodeStatus DecodeVST3LN(MCInst &Inst, unsigned Insn,
310                                uint64_t Address, const void *Decoder);
311 static DecodeStatus DecodeVST4LN(MCInst &Inst, unsigned Insn,
312                                uint64_t Address, const void *Decoder);
313 static DecodeStatus DecodeVMOVSRR(MCInst &Inst, unsigned Insn,
314                                uint64_t Address, const void *Decoder);
315 static DecodeStatus DecodeVMOVRRS(MCInst &Inst, unsigned Insn,
316                                uint64_t Address, const void *Decoder);
317 static DecodeStatus DecodeSwap(MCInst &Inst, unsigned Insn,
318                                uint64_t Address, const void *Decoder);
319 static DecodeStatus DecodeVCVTD(MCInst &Inst, unsigned Insn,
320                                 uint64_t Address, const void *Decoder);
321 static DecodeStatus DecodeVCVTQ(MCInst &Inst, unsigned Insn,
322                                 uint64_t Address, const void *Decoder);
323 
324 static DecodeStatus DecodeThumbAddSpecialReg(MCInst &Inst, uint16_t Insn,
325                                uint64_t Address, const void *Decoder);
326 static DecodeStatus DecodeThumbBROperand(MCInst &Inst, unsigned Val,
327                                uint64_t Address, const void *Decoder);
328 static DecodeStatus DecodeT2BROperand(MCInst &Inst, unsigned Val,
329                                uint64_t Address, const void *Decoder);
330 static DecodeStatus DecodeThumbCmpBROperand(MCInst &Inst, unsigned Val,
331                                uint64_t Address, const void *Decoder);
332 static DecodeStatus DecodeThumbAddrModeRR(MCInst &Inst, unsigned Val,
333                                uint64_t Address, const void *Decoder);
334 static DecodeStatus DecodeThumbAddrModeIS(MCInst &Inst, unsigned Val,
335                                uint64_t Address, const void *Decoder);
336 static DecodeStatus DecodeThumbAddrModePC(MCInst &Inst, unsigned Val,
337                                uint64_t Address, const void *Decoder);
338 static DecodeStatus DecodeThumbAddrModeSP(MCInst &Inst, unsigned Val,
339                                uint64_t Address, const void *Decoder);
340 static DecodeStatus DecodeT2AddrModeSOReg(MCInst &Inst, unsigned Val,
341                                uint64_t Address, const void *Decoder);
342 static DecodeStatus DecodeT2LoadShift(MCInst &Inst, unsigned Val,
343                                uint64_t Address, const void *Decoder);
344 static DecodeStatus DecodeT2LoadImm8(MCInst &Inst, unsigned Insn,
345                                uint64_t Address, const void* Decoder);
346 static DecodeStatus DecodeT2LoadImm12(MCInst &Inst, unsigned Insn,
347                                uint64_t Address, const void* Decoder);
348 static DecodeStatus DecodeT2LoadT(MCInst &Inst, unsigned Insn,
349                                uint64_t Address, const void* Decoder);
350 static DecodeStatus DecodeT2LoadLabel(MCInst &Inst, unsigned Insn,
351                                uint64_t Address, const void* Decoder);
352 static DecodeStatus DecodeT2Imm8S4(MCInst &Inst, unsigned Val,
353                                uint64_t Address, const void *Decoder);
354 static DecodeStatus DecodeT2AddrModeImm8s4(MCInst &Inst, unsigned Val,
355                                uint64_t Address, const void *Decoder);
356 static DecodeStatus DecodeT2AddrModeImm0_1020s4(MCInst &Inst,unsigned Val,
357                                uint64_t Address, const void *Decoder);
358 static DecodeStatus DecodeT2Imm8(MCInst &Inst, unsigned Val,
359                                uint64_t Address, const void *Decoder);
360 static DecodeStatus DecodeT2AddrModeImm8(MCInst &Inst, unsigned Val,
361                                uint64_t Address, const void *Decoder);
362 static DecodeStatus DecodeThumbAddSPImm(MCInst &Inst, uint16_t Val,
363                                uint64_t Address, const void *Decoder);
364 static DecodeStatus DecodeThumbAddSPReg(MCInst &Inst, uint16_t Insn,
365                                 uint64_t Address, const void *Decoder);
366 static DecodeStatus DecodeThumbCPS(MCInst &Inst, uint16_t Insn,
367                                 uint64_t Address, const void *Decoder);
368 static DecodeStatus DecodeQADDInstruction(MCInst &Inst, unsigned Insn,
369                                 uint64_t Address, const void *Decoder);
370 static DecodeStatus DecodeThumbBLXOffset(MCInst &Inst, unsigned Insn,
371                                 uint64_t Address, const void *Decoder);
372 static DecodeStatus DecodeT2AddrModeImm12(MCInst &Inst, unsigned Val,
373                                 uint64_t Address, const void *Decoder);
374 static DecodeStatus DecodeThumbTableBranch(MCInst &Inst, unsigned Val,
375                                 uint64_t Address, const void *Decoder);
376 static DecodeStatus DecodeThumb2BCCInstruction(MCInst &Inst, unsigned Val,
377                                 uint64_t Address, const void *Decoder);
378 static DecodeStatus DecodeT2SOImm(MCInst &Inst, unsigned Val,
379                                 uint64_t Address, const void *Decoder);
380 static DecodeStatus DecodeThumbBCCTargetOperand(MCInst &Inst,unsigned Val,
381                                 uint64_t Address, const void *Decoder);
382 static DecodeStatus DecodeThumbBLTargetOperand(MCInst &Inst, unsigned Val,
383                                 uint64_t Address, const void *Decoder);
384 static DecodeStatus DecodeIT(MCInst &Inst, unsigned Val,
385                                 uint64_t Address, const void *Decoder);
386 static DecodeStatus DecodeT2LDRDPreInstruction(MCInst &Inst,unsigned Insn,
387                                uint64_t Address, const void *Decoder);
388 static DecodeStatus DecodeT2STRDPreInstruction(MCInst &Inst,unsigned Insn,
389                                uint64_t Address, const void *Decoder);
390 static DecodeStatus DecodeT2Adr(MCInst &Inst, unsigned Val,
391                                 uint64_t Address, const void *Decoder);
392 static DecodeStatus DecodeT2LdStPre(MCInst &Inst, unsigned Val,
393                                 uint64_t Address, const void *Decoder);
394 static DecodeStatus DecodeT2ShifterImmOperand(MCInst &Inst, unsigned Val,
395                                 uint64_t Address, const void *Decoder);
396 
397 static DecodeStatus DecodeLDR(MCInst &Inst, unsigned Val,
398                                 uint64_t Address, const void *Decoder);
399 static DecodeStatus DecoderForMRRC2AndMCRR2(MCInst &Inst, unsigned Val,
400                                             uint64_t Address, const void *Decoder);
401 
402 #include "ARMGenDisassemblerTables.inc"
403 
404 static MCDisassembler *createARMDisassembler(const Target &T,
405                                              const MCSubtargetInfo &STI,
406                                              MCContext &Ctx) {
407   return new ARMDisassembler(STI, Ctx);
408 }
409 
410 static MCDisassembler *createThumbDisassembler(const Target &T,
411                                                const MCSubtargetInfo &STI,
412                                                MCContext &Ctx) {
413   return new ThumbDisassembler(STI, Ctx);
414 }
415 
416 // Post-decoding checks
417 static DecodeStatus checkDecodedInstruction(MCInst &MI, uint64_t &Size,
418                                             uint64_t Address, raw_ostream &OS,
419                                             raw_ostream &CS,
420                                             uint32_t Insn,
421                                             DecodeStatus Result) {
422   switch (MI.getOpcode()) {
423     case ARM::HVC: {
424       // HVC is undefined if condition = 0xf otherwise upredictable
425       // if condition != 0xe
426       uint32_t Cond = (Insn >> 28) & 0xF;
427       if (Cond == 0xF)
428         return MCDisassembler::Fail;
429       if (Cond != 0xE)
430         return MCDisassembler::SoftFail;
431       return Result;
432     }
433     default: return Result;
434   }
435 }
436 
437 DecodeStatus ARMDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
438                                              ArrayRef<uint8_t> Bytes,
439                                              uint64_t Address, raw_ostream &OS,
440                                              raw_ostream &CS) const {
441   CommentStream = &CS;
442 
443   assert(!STI.getFeatureBits()[ARM::ModeThumb] &&
444          "Asked to disassemble an ARM instruction but Subtarget is in Thumb "
445          "mode!");
446 
447   // We want to read exactly 4 bytes of data.
448   if (Bytes.size() < 4) {
449     Size = 0;
450     return MCDisassembler::Fail;
451   }
452 
453   // Encoded as a small-endian 32-bit word in the stream.
454   uint32_t Insn =
455       (Bytes[3] << 24) | (Bytes[2] << 16) | (Bytes[1] << 8) | (Bytes[0] << 0);
456 
457   // Calling the auto-generated decoder function.
458   DecodeStatus Result =
459       decodeInstruction(DecoderTableARM32, MI, Insn, Address, this, STI);
460   if (Result != MCDisassembler::Fail) {
461     Size = 4;
462     return checkDecodedInstruction(MI, Size, Address, OS, CS, Insn, Result);
463   }
464 
465   // VFP and NEON instructions, similarly, are shared between ARM
466   // and Thumb modes.
467   Result = decodeInstruction(DecoderTableVFP32, MI, Insn, Address, this, STI);
468   if (Result != MCDisassembler::Fail) {
469     Size = 4;
470     return Result;
471   }
472 
473   Result = decodeInstruction(DecoderTableVFPV832, MI, Insn, Address, this, STI);
474   if (Result != MCDisassembler::Fail) {
475     Size = 4;
476     return Result;
477   }
478 
479   Result =
480       decodeInstruction(DecoderTableNEONData32, MI, Insn, Address, this, STI);
481   if (Result != MCDisassembler::Fail) {
482     Size = 4;
483     // Add a fake predicate operand, because we share these instruction
484     // definitions with Thumb2 where these instructions are predicable.
485     if (!DecodePredicateOperand(MI, 0xE, Address, this))
486       return MCDisassembler::Fail;
487     return Result;
488   }
489 
490   Result = decodeInstruction(DecoderTableNEONLoadStore32, MI, Insn, Address,
491                              this, STI);
492   if (Result != MCDisassembler::Fail) {
493     Size = 4;
494     // Add a fake predicate operand, because we share these instruction
495     // definitions with Thumb2 where these instructions are predicable.
496     if (!DecodePredicateOperand(MI, 0xE, Address, this))
497       return MCDisassembler::Fail;
498     return Result;
499   }
500 
501   Result =
502       decodeInstruction(DecoderTableNEONDup32, MI, Insn, Address, this, STI);
503   if (Result != MCDisassembler::Fail) {
504     Size = 4;
505     // Add a fake predicate operand, because we share these instruction
506     // definitions with Thumb2 where these instructions are predicable.
507     if (!DecodePredicateOperand(MI, 0xE, Address, this))
508       return MCDisassembler::Fail;
509     return Result;
510   }
511 
512   Result =
513       decodeInstruction(DecoderTablev8NEON32, MI, Insn, Address, this, STI);
514   if (Result != MCDisassembler::Fail) {
515     Size = 4;
516     return Result;
517   }
518 
519   Result =
520       decodeInstruction(DecoderTablev8Crypto32, MI, Insn, Address, this, STI);
521   if (Result != MCDisassembler::Fail) {
522     Size = 4;
523     return Result;
524   }
525 
526   Size = 0;
527   return MCDisassembler::Fail;
528 }
529 
530 namespace llvm {
531 
532 extern const MCInstrDesc ARMInsts[];
533 
534 } // end namespace llvm
535 
536 /// tryAddingSymbolicOperand - trys to add a symbolic operand in place of the
537 /// immediate Value in the MCInst.  The immediate Value has had any PC
538 /// adjustment made by the caller.  If the instruction is a branch instruction
539 /// then isBranch is true, else false.  If the getOpInfo() function was set as
540 /// part of the setupForSymbolicDisassembly() call then that function is called
541 /// to get any symbolic information at the Address for this instruction.  If
542 /// that returns non-zero then the symbolic information it returns is used to
543 /// create an MCExpr and that is added as an operand to the MCInst.  If
544 /// getOpInfo() returns zero and isBranch is true then a symbol look up for
545 /// Value is done and if a symbol is found an MCExpr is created with that, else
546 /// an MCExpr with Value is created.  This function returns true if it adds an
547 /// operand to the MCInst and false otherwise.
548 static bool tryAddingSymbolicOperand(uint64_t Address, int32_t Value,
549                                      bool isBranch, uint64_t InstSize,
550                                      MCInst &MI, const void *Decoder) {
551   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
552   // FIXME: Does it make sense for value to be negative?
553   return Dis->tryAddingSymbolicOperand(MI, (uint32_t)Value, Address, isBranch,
554                                        /* Offset */ 0, InstSize);
555 }
556 
557 /// tryAddingPcLoadReferenceComment - trys to add a comment as to what is being
558 /// referenced by a load instruction with the base register that is the Pc.
559 /// These can often be values in a literal pool near the Address of the
560 /// instruction.  The Address of the instruction and its immediate Value are
561 /// used as a possible literal pool entry.  The SymbolLookUp call back will
562 /// return the name of a symbol referenced by the literal pool's entry if
563 /// the referenced address is that of a symbol.  Or it will return a pointer to
564 /// a literal 'C' string if the referenced address of the literal pool's entry
565 /// is an address into a section with 'C' string literals.
566 static void tryAddingPcLoadReferenceComment(uint64_t Address, int Value,
567                                             const void *Decoder) {
568   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
569   Dis->tryAddingPcLoadReferenceComment(Value, Address);
570 }
571 
572 // Thumb1 instructions don't have explicit S bits.  Rather, they
573 // implicitly set CPSR.  Since it's not represented in the encoding, the
574 // auto-generated decoder won't inject the CPSR operand.  We need to fix
575 // that as a post-pass.
576 static void AddThumb1SBit(MCInst &MI, bool InITBlock) {
577   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
578   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
579   MCInst::iterator I = MI.begin();
580   for (unsigned i = 0; i < NumOps; ++i, ++I) {
581     if (I == MI.end()) break;
582     if (OpInfo[i].isOptionalDef() && OpInfo[i].RegClass == ARM::CCRRegClassID) {
583       if (i > 0 && OpInfo[i-1].isPredicate()) continue;
584       MI.insert(I, MCOperand::createReg(InITBlock ? 0 : ARM::CPSR));
585       return;
586     }
587   }
588 
589   MI.insert(I, MCOperand::createReg(InITBlock ? 0 : ARM::CPSR));
590 }
591 
592 // Most Thumb instructions don't have explicit predicates in the
593 // encoding, but rather get their predicates from IT context.  We need
594 // to fix up the predicate operands using this context information as a
595 // post-pass.
596 MCDisassembler::DecodeStatus
597 ThumbDisassembler::AddThumbPredicate(MCInst &MI) const {
598   MCDisassembler::DecodeStatus S = Success;
599 
600   const FeatureBitset &FeatureBits = getSubtargetInfo().getFeatureBits();
601 
602   // A few instructions actually have predicates encoded in them.  Don't
603   // try to overwrite it if we're seeing one of those.
604   switch (MI.getOpcode()) {
605     case ARM::tBcc:
606     case ARM::t2Bcc:
607     case ARM::tCBZ:
608     case ARM::tCBNZ:
609     case ARM::tCPS:
610     case ARM::t2CPS3p:
611     case ARM::t2CPS2p:
612     case ARM::t2CPS1p:
613     case ARM::tMOVSr:
614     case ARM::tSETEND:
615       // Some instructions (mostly conditional branches) are not
616       // allowed in IT blocks.
617       if (ITBlock.instrInITBlock())
618         S = SoftFail;
619       else
620         return Success;
621       break;
622     case ARM::t2HINT:
623       if (MI.getOperand(0).getImm() == 0x10 && (FeatureBits[ARM::FeatureRAS]) != 0)
624         S = SoftFail;
625       break;
626     case ARM::tB:
627     case ARM::t2B:
628     case ARM::t2TBB:
629     case ARM::t2TBH:
630       // Some instructions (mostly unconditional branches) can
631       // only appears at the end of, or outside of, an IT.
632       if (ITBlock.instrInITBlock() && !ITBlock.instrLastInITBlock())
633         S = SoftFail;
634       break;
635     default:
636       break;
637   }
638 
639   // If we're in an IT block, base the predicate on that.  Otherwise,
640   // assume a predicate of AL.
641   unsigned CC;
642   CC = ITBlock.getITCC();
643   if (CC == 0xF)
644     CC = ARMCC::AL;
645   if (ITBlock.instrInITBlock())
646     ITBlock.advanceITState();
647 
648   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
649   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
650   MCInst::iterator I = MI.begin();
651   for (unsigned i = 0; i < NumOps; ++i, ++I) {
652     if (I == MI.end()) break;
653     if (OpInfo[i].isPredicate()) {
654       I = MI.insert(I, MCOperand::createImm(CC));
655       ++I;
656       if (CC == ARMCC::AL)
657         MI.insert(I, MCOperand::createReg(0));
658       else
659         MI.insert(I, MCOperand::createReg(ARM::CPSR));
660       return S;
661     }
662   }
663 
664   I = MI.insert(I, MCOperand::createImm(CC));
665   ++I;
666   if (CC == ARMCC::AL)
667     MI.insert(I, MCOperand::createReg(0));
668   else
669     MI.insert(I, MCOperand::createReg(ARM::CPSR));
670 
671   return S;
672 }
673 
674 // Thumb VFP instructions are a special case.  Because we share their
675 // encodings between ARM and Thumb modes, and they are predicable in ARM
676 // mode, the auto-generated decoder will give them an (incorrect)
677 // predicate operand.  We need to rewrite these operands based on the IT
678 // context as a post-pass.
679 void ThumbDisassembler::UpdateThumbVFPPredicate(MCInst &MI) const {
680   unsigned CC;
681   CC = ITBlock.getITCC();
682   if (ITBlock.instrInITBlock())
683     ITBlock.advanceITState();
684 
685   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
686   MCInst::iterator I = MI.begin();
687   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
688   for (unsigned i = 0; i < NumOps; ++i, ++I) {
689     if (OpInfo[i].isPredicate() ) {
690       I->setImm(CC);
691       ++I;
692       if (CC == ARMCC::AL)
693         I->setReg(0);
694       else
695         I->setReg(ARM::CPSR);
696       return;
697     }
698   }
699 }
700 
701 DecodeStatus ThumbDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
702                                                ArrayRef<uint8_t> Bytes,
703                                                uint64_t Address,
704                                                raw_ostream &OS,
705                                                raw_ostream &CS) const {
706   CommentStream = &CS;
707 
708   assert(STI.getFeatureBits()[ARM::ModeThumb] &&
709          "Asked to disassemble in Thumb mode but Subtarget is in ARM mode!");
710 
711   // We want to read exactly 2 bytes of data.
712   if (Bytes.size() < 2) {
713     Size = 0;
714     return MCDisassembler::Fail;
715   }
716 
717   uint16_t Insn16 = (Bytes[1] << 8) | Bytes[0];
718   DecodeStatus Result =
719       decodeInstruction(DecoderTableThumb16, MI, Insn16, Address, this, STI);
720   if (Result != MCDisassembler::Fail) {
721     Size = 2;
722     Check(Result, AddThumbPredicate(MI));
723     return Result;
724   }
725 
726   Result = decodeInstruction(DecoderTableThumbSBit16, MI, Insn16, Address, this,
727                              STI);
728   if (Result) {
729     Size = 2;
730     bool InITBlock = ITBlock.instrInITBlock();
731     Check(Result, AddThumbPredicate(MI));
732     AddThumb1SBit(MI, InITBlock);
733     return Result;
734   }
735 
736   Result =
737       decodeInstruction(DecoderTableThumb216, MI, Insn16, Address, this, STI);
738   if (Result != MCDisassembler::Fail) {
739     Size = 2;
740 
741     // Nested IT blocks are UNPREDICTABLE.  Must be checked before we add
742     // the Thumb predicate.
743     if (MI.getOpcode() == ARM::t2IT && ITBlock.instrInITBlock())
744       Result = MCDisassembler::SoftFail;
745 
746     Check(Result, AddThumbPredicate(MI));
747 
748     // If we find an IT instruction, we need to parse its condition
749     // code and mask operands so that we can apply them correctly
750     // to the subsequent instructions.
751     if (MI.getOpcode() == ARM::t2IT) {
752 
753       unsigned Firstcond = MI.getOperand(0).getImm();
754       unsigned Mask = MI.getOperand(1).getImm();
755       ITBlock.setITState(Firstcond, Mask);
756     }
757 
758     return Result;
759   }
760 
761   // We want to read exactly 4 bytes of data.
762   if (Bytes.size() < 4) {
763     Size = 0;
764     return MCDisassembler::Fail;
765   }
766 
767   uint32_t Insn32 =
768       (Bytes[3] << 8) | (Bytes[2] << 0) | (Bytes[1] << 24) | (Bytes[0] << 16);
769   Result =
770       decodeInstruction(DecoderTableThumb32, MI, Insn32, Address, this, STI);
771   if (Result != MCDisassembler::Fail) {
772     Size = 4;
773     bool InITBlock = ITBlock.instrInITBlock();
774     Check(Result, AddThumbPredicate(MI));
775     AddThumb1SBit(MI, InITBlock);
776     return Result;
777   }
778 
779   Result =
780       decodeInstruction(DecoderTableThumb232, MI, Insn32, Address, this, STI);
781   if (Result != MCDisassembler::Fail) {
782     Size = 4;
783     Check(Result, AddThumbPredicate(MI));
784     return Result;
785   }
786 
787   if (fieldFromInstruction(Insn32, 28, 4) == 0xE) {
788     Result =
789         decodeInstruction(DecoderTableVFP32, MI, Insn32, Address, this, STI);
790     if (Result != MCDisassembler::Fail) {
791       Size = 4;
792       UpdateThumbVFPPredicate(MI);
793       return Result;
794     }
795   }
796 
797   Result =
798       decodeInstruction(DecoderTableVFPV832, MI, Insn32, Address, this, STI);
799   if (Result != MCDisassembler::Fail) {
800     Size = 4;
801     return Result;
802   }
803 
804   if (fieldFromInstruction(Insn32, 28, 4) == 0xE) {
805     Result = decodeInstruction(DecoderTableNEONDup32, MI, Insn32, Address, this,
806                                STI);
807     if (Result != MCDisassembler::Fail) {
808       Size = 4;
809       Check(Result, AddThumbPredicate(MI));
810       return Result;
811     }
812   }
813 
814   if (fieldFromInstruction(Insn32, 24, 8) == 0xF9) {
815     uint32_t NEONLdStInsn = Insn32;
816     NEONLdStInsn &= 0xF0FFFFFF;
817     NEONLdStInsn |= 0x04000000;
818     Result = decodeInstruction(DecoderTableNEONLoadStore32, MI, NEONLdStInsn,
819                                Address, this, STI);
820     if (Result != MCDisassembler::Fail) {
821       Size = 4;
822       Check(Result, AddThumbPredicate(MI));
823       return Result;
824     }
825   }
826 
827   if (fieldFromInstruction(Insn32, 24, 4) == 0xF) {
828     uint32_t NEONDataInsn = Insn32;
829     NEONDataInsn &= 0xF0FFFFFF; // Clear bits 27-24
830     NEONDataInsn |= (NEONDataInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
831     NEONDataInsn |= 0x12000000; // Set bits 28 and 25
832     Result = decodeInstruction(DecoderTableNEONData32, MI, NEONDataInsn,
833                                Address, this, STI);
834     if (Result != MCDisassembler::Fail) {
835       Size = 4;
836       Check(Result, AddThumbPredicate(MI));
837       return Result;
838     }
839 
840     uint32_t NEONCryptoInsn = Insn32;
841     NEONCryptoInsn &= 0xF0FFFFFF; // Clear bits 27-24
842     NEONCryptoInsn |= (NEONCryptoInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
843     NEONCryptoInsn |= 0x12000000; // Set bits 28 and 25
844     Result = decodeInstruction(DecoderTablev8Crypto32, MI, NEONCryptoInsn,
845                                Address, this, STI);
846     if (Result != MCDisassembler::Fail) {
847       Size = 4;
848       return Result;
849     }
850 
851     uint32_t NEONv8Insn = Insn32;
852     NEONv8Insn &= 0xF3FFFFFF; // Clear bits 27-26
853     Result = decodeInstruction(DecoderTablev8NEON32, MI, NEONv8Insn, Address,
854                                this, STI);
855     if (Result != MCDisassembler::Fail) {
856       Size = 4;
857       return Result;
858     }
859   }
860 
861   Size = 0;
862   return MCDisassembler::Fail;
863 }
864 
865 extern "C" void LLVMInitializeARMDisassembler() {
866   TargetRegistry::RegisterMCDisassembler(getTheARMLETarget(),
867                                          createARMDisassembler);
868   TargetRegistry::RegisterMCDisassembler(getTheARMBETarget(),
869                                          createARMDisassembler);
870   TargetRegistry::RegisterMCDisassembler(getTheThumbLETarget(),
871                                          createThumbDisassembler);
872   TargetRegistry::RegisterMCDisassembler(getTheThumbBETarget(),
873                                          createThumbDisassembler);
874 }
875 
876 static const uint16_t GPRDecoderTable[] = {
877   ARM::R0, ARM::R1, ARM::R2, ARM::R3,
878   ARM::R4, ARM::R5, ARM::R6, ARM::R7,
879   ARM::R8, ARM::R9, ARM::R10, ARM::R11,
880   ARM::R12, ARM::SP, ARM::LR, ARM::PC
881 };
882 
883 static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, unsigned RegNo,
884                                    uint64_t Address, const void *Decoder) {
885   if (RegNo > 15)
886     return MCDisassembler::Fail;
887 
888   unsigned Register = GPRDecoderTable[RegNo];
889   Inst.addOperand(MCOperand::createReg(Register));
890   return MCDisassembler::Success;
891 }
892 
893 static DecodeStatus
894 DecodeGPRnopcRegisterClass(MCInst &Inst, unsigned RegNo,
895                            uint64_t Address, const void *Decoder) {
896   DecodeStatus S = MCDisassembler::Success;
897 
898   if (RegNo == 15)
899     S = MCDisassembler::SoftFail;
900 
901   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
902 
903   return S;
904 }
905 
906 static DecodeStatus
907 DecodeGPRwithAPSRRegisterClass(MCInst &Inst, unsigned RegNo,
908                                uint64_t Address, const void *Decoder) {
909   DecodeStatus S = MCDisassembler::Success;
910 
911   if (RegNo == 15)
912   {
913     Inst.addOperand(MCOperand::createReg(ARM::APSR_NZCV));
914     return MCDisassembler::Success;
915   }
916 
917   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
918   return S;
919 }
920 
921 static DecodeStatus DecodetGPRRegisterClass(MCInst &Inst, unsigned RegNo,
922                                    uint64_t Address, const void *Decoder) {
923   if (RegNo > 7)
924     return MCDisassembler::Fail;
925   return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
926 }
927 
928 static const uint16_t GPRPairDecoderTable[] = {
929   ARM::R0_R1, ARM::R2_R3,   ARM::R4_R5,  ARM::R6_R7,
930   ARM::R8_R9, ARM::R10_R11, ARM::R12_SP
931 };
932 
933 static DecodeStatus DecodeGPRPairRegisterClass(MCInst &Inst, unsigned RegNo,
934                                    uint64_t Address, const void *Decoder) {
935   DecodeStatus S = MCDisassembler::Success;
936 
937   if (RegNo > 13)
938     return MCDisassembler::Fail;
939 
940   if ((RegNo & 1) || RegNo == 0xe)
941      S = MCDisassembler::SoftFail;
942 
943   unsigned RegisterPair = GPRPairDecoderTable[RegNo/2];
944   Inst.addOperand(MCOperand::createReg(RegisterPair));
945   return S;
946 }
947 
948 static DecodeStatus DecodetcGPRRegisterClass(MCInst &Inst, unsigned RegNo,
949                                    uint64_t Address, const void *Decoder) {
950   unsigned Register = 0;
951   switch (RegNo) {
952     case 0:
953       Register = ARM::R0;
954       break;
955     case 1:
956       Register = ARM::R1;
957       break;
958     case 2:
959       Register = ARM::R2;
960       break;
961     case 3:
962       Register = ARM::R3;
963       break;
964     case 9:
965       Register = ARM::R9;
966       break;
967     case 12:
968       Register = ARM::R12;
969       break;
970     default:
971       return MCDisassembler::Fail;
972     }
973 
974   Inst.addOperand(MCOperand::createReg(Register));
975   return MCDisassembler::Success;
976 }
977 
978 static DecodeStatus DecoderGPRRegisterClass(MCInst &Inst, unsigned RegNo,
979                                    uint64_t Address, const void *Decoder) {
980   DecodeStatus S = MCDisassembler::Success;
981 
982   const FeatureBitset &featureBits =
983     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
984 
985   if ((RegNo == 13 && !featureBits[ARM::HasV8Ops]) || RegNo == 15)
986     S = MCDisassembler::SoftFail;
987 
988   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
989   return S;
990 }
991 
992 static const uint16_t SPRDecoderTable[] = {
993      ARM::S0,  ARM::S1,  ARM::S2,  ARM::S3,
994      ARM::S4,  ARM::S5,  ARM::S6,  ARM::S7,
995      ARM::S8,  ARM::S9, ARM::S10, ARM::S11,
996     ARM::S12, ARM::S13, ARM::S14, ARM::S15,
997     ARM::S16, ARM::S17, ARM::S18, ARM::S19,
998     ARM::S20, ARM::S21, ARM::S22, ARM::S23,
999     ARM::S24, ARM::S25, ARM::S26, ARM::S27,
1000     ARM::S28, ARM::S29, ARM::S30, ARM::S31
1001 };
1002 
1003 static DecodeStatus DecodeSPRRegisterClass(MCInst &Inst, unsigned RegNo,
1004                                    uint64_t Address, const void *Decoder) {
1005   if (RegNo > 31)
1006     return MCDisassembler::Fail;
1007 
1008   unsigned Register = SPRDecoderTable[RegNo];
1009   Inst.addOperand(MCOperand::createReg(Register));
1010   return MCDisassembler::Success;
1011 }
1012 
1013 static const uint16_t DPRDecoderTable[] = {
1014      ARM::D0,  ARM::D1,  ARM::D2,  ARM::D3,
1015      ARM::D4,  ARM::D5,  ARM::D6,  ARM::D7,
1016      ARM::D8,  ARM::D9, ARM::D10, ARM::D11,
1017     ARM::D12, ARM::D13, ARM::D14, ARM::D15,
1018     ARM::D16, ARM::D17, ARM::D18, ARM::D19,
1019     ARM::D20, ARM::D21, ARM::D22, ARM::D23,
1020     ARM::D24, ARM::D25, ARM::D26, ARM::D27,
1021     ARM::D28, ARM::D29, ARM::D30, ARM::D31
1022 };
1023 
1024 static DecodeStatus DecodeDPRRegisterClass(MCInst &Inst, unsigned RegNo,
1025                                    uint64_t Address, const void *Decoder) {
1026   const FeatureBitset &featureBits =
1027     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1028 
1029   bool hasD16 = featureBits[ARM::FeatureD16];
1030 
1031   if (RegNo > 31 || (hasD16 && RegNo > 15))
1032     return MCDisassembler::Fail;
1033 
1034   unsigned Register = DPRDecoderTable[RegNo];
1035   Inst.addOperand(MCOperand::createReg(Register));
1036   return MCDisassembler::Success;
1037 }
1038 
1039 static DecodeStatus DecodeDPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
1040                                    uint64_t Address, const void *Decoder) {
1041   if (RegNo > 7)
1042     return MCDisassembler::Fail;
1043   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
1044 }
1045 
1046 static DecodeStatus
1047 DecodeDPR_VFP2RegisterClass(MCInst &Inst, unsigned RegNo,
1048                             uint64_t Address, const void *Decoder) {
1049   if (RegNo > 15)
1050     return MCDisassembler::Fail;
1051   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
1052 }
1053 
1054 static const uint16_t QPRDecoderTable[] = {
1055      ARM::Q0,  ARM::Q1,  ARM::Q2,  ARM::Q3,
1056      ARM::Q4,  ARM::Q5,  ARM::Q6,  ARM::Q7,
1057      ARM::Q8,  ARM::Q9, ARM::Q10, ARM::Q11,
1058     ARM::Q12, ARM::Q13, ARM::Q14, ARM::Q15
1059 };
1060 
1061 static DecodeStatus DecodeQPRRegisterClass(MCInst &Inst, unsigned RegNo,
1062                                    uint64_t Address, const void *Decoder) {
1063   if (RegNo > 31 || (RegNo & 1) != 0)
1064     return MCDisassembler::Fail;
1065   RegNo >>= 1;
1066 
1067   unsigned Register = QPRDecoderTable[RegNo];
1068   Inst.addOperand(MCOperand::createReg(Register));
1069   return MCDisassembler::Success;
1070 }
1071 
1072 static const uint16_t DPairDecoderTable[] = {
1073   ARM::Q0,  ARM::D1_D2,   ARM::Q1,  ARM::D3_D4,   ARM::Q2,  ARM::D5_D6,
1074   ARM::Q3,  ARM::D7_D8,   ARM::Q4,  ARM::D9_D10,  ARM::Q5,  ARM::D11_D12,
1075   ARM::Q6,  ARM::D13_D14, ARM::Q7,  ARM::D15_D16, ARM::Q8,  ARM::D17_D18,
1076   ARM::Q9,  ARM::D19_D20, ARM::Q10, ARM::D21_D22, ARM::Q11, ARM::D23_D24,
1077   ARM::Q12, ARM::D25_D26, ARM::Q13, ARM::D27_D28, ARM::Q14, ARM::D29_D30,
1078   ARM::Q15
1079 };
1080 
1081 static DecodeStatus DecodeDPairRegisterClass(MCInst &Inst, unsigned RegNo,
1082                                    uint64_t Address, const void *Decoder) {
1083   if (RegNo > 30)
1084     return MCDisassembler::Fail;
1085 
1086   unsigned Register = DPairDecoderTable[RegNo];
1087   Inst.addOperand(MCOperand::createReg(Register));
1088   return MCDisassembler::Success;
1089 }
1090 
1091 static const uint16_t DPairSpacedDecoderTable[] = {
1092   ARM::D0_D2,   ARM::D1_D3,   ARM::D2_D4,   ARM::D3_D5,
1093   ARM::D4_D6,   ARM::D5_D7,   ARM::D6_D8,   ARM::D7_D9,
1094   ARM::D8_D10,  ARM::D9_D11,  ARM::D10_D12, ARM::D11_D13,
1095   ARM::D12_D14, ARM::D13_D15, ARM::D14_D16, ARM::D15_D17,
1096   ARM::D16_D18, ARM::D17_D19, ARM::D18_D20, ARM::D19_D21,
1097   ARM::D20_D22, ARM::D21_D23, ARM::D22_D24, ARM::D23_D25,
1098   ARM::D24_D26, ARM::D25_D27, ARM::D26_D28, ARM::D27_D29,
1099   ARM::D28_D30, ARM::D29_D31
1100 };
1101 
1102 static DecodeStatus DecodeDPairSpacedRegisterClass(MCInst &Inst,
1103                                                    unsigned RegNo,
1104                                                    uint64_t Address,
1105                                                    const void *Decoder) {
1106   if (RegNo > 29)
1107     return MCDisassembler::Fail;
1108 
1109   unsigned Register = DPairSpacedDecoderTable[RegNo];
1110   Inst.addOperand(MCOperand::createReg(Register));
1111   return MCDisassembler::Success;
1112 }
1113 
1114 static DecodeStatus DecodePredicateOperand(MCInst &Inst, unsigned Val,
1115                                uint64_t Address, const void *Decoder) {
1116   if (Val == 0xF) return MCDisassembler::Fail;
1117   // AL predicate is not allowed on Thumb1 branches.
1118   if (Inst.getOpcode() == ARM::tBcc && Val == 0xE)
1119     return MCDisassembler::Fail;
1120   Inst.addOperand(MCOperand::createImm(Val));
1121   if (Val == ARMCC::AL) {
1122     Inst.addOperand(MCOperand::createReg(0));
1123   } else
1124     Inst.addOperand(MCOperand::createReg(ARM::CPSR));
1125   return MCDisassembler::Success;
1126 }
1127 
1128 static DecodeStatus DecodeCCOutOperand(MCInst &Inst, unsigned Val,
1129                                uint64_t Address, const void *Decoder) {
1130   if (Val)
1131     Inst.addOperand(MCOperand::createReg(ARM::CPSR));
1132   else
1133     Inst.addOperand(MCOperand::createReg(0));
1134   return MCDisassembler::Success;
1135 }
1136 
1137 static DecodeStatus DecodeSORegImmOperand(MCInst &Inst, unsigned Val,
1138                                uint64_t Address, const void *Decoder) {
1139   DecodeStatus S = MCDisassembler::Success;
1140 
1141   unsigned Rm = fieldFromInstruction(Val, 0, 4);
1142   unsigned type = fieldFromInstruction(Val, 5, 2);
1143   unsigned imm = fieldFromInstruction(Val, 7, 5);
1144 
1145   // Register-immediate
1146   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
1147     return MCDisassembler::Fail;
1148 
1149   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1150   switch (type) {
1151     case 0:
1152       Shift = ARM_AM::lsl;
1153       break;
1154     case 1:
1155       Shift = ARM_AM::lsr;
1156       break;
1157     case 2:
1158       Shift = ARM_AM::asr;
1159       break;
1160     case 3:
1161       Shift = ARM_AM::ror;
1162       break;
1163   }
1164 
1165   if (Shift == ARM_AM::ror && imm == 0)
1166     Shift = ARM_AM::rrx;
1167 
1168   unsigned Op = Shift | (imm << 3);
1169   Inst.addOperand(MCOperand::createImm(Op));
1170 
1171   return S;
1172 }
1173 
1174 static DecodeStatus DecodeSORegRegOperand(MCInst &Inst, unsigned Val,
1175                                uint64_t Address, const void *Decoder) {
1176   DecodeStatus S = MCDisassembler::Success;
1177 
1178   unsigned Rm = fieldFromInstruction(Val, 0, 4);
1179   unsigned type = fieldFromInstruction(Val, 5, 2);
1180   unsigned Rs = fieldFromInstruction(Val, 8, 4);
1181 
1182   // Register-register
1183   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1184     return MCDisassembler::Fail;
1185   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rs, Address, Decoder)))
1186     return MCDisassembler::Fail;
1187 
1188   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1189   switch (type) {
1190     case 0:
1191       Shift = ARM_AM::lsl;
1192       break;
1193     case 1:
1194       Shift = ARM_AM::lsr;
1195       break;
1196     case 2:
1197       Shift = ARM_AM::asr;
1198       break;
1199     case 3:
1200       Shift = ARM_AM::ror;
1201       break;
1202   }
1203 
1204   Inst.addOperand(MCOperand::createImm(Shift));
1205 
1206   return S;
1207 }
1208 
1209 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Val,
1210                                  uint64_t Address, const void *Decoder) {
1211   DecodeStatus S = MCDisassembler::Success;
1212 
1213   bool NeedDisjointWriteback = false;
1214   unsigned WritebackReg = 0;
1215   switch (Inst.getOpcode()) {
1216   default:
1217     break;
1218   case ARM::LDMIA_UPD:
1219   case ARM::LDMDB_UPD:
1220   case ARM::LDMIB_UPD:
1221   case ARM::LDMDA_UPD:
1222   case ARM::t2LDMIA_UPD:
1223   case ARM::t2LDMDB_UPD:
1224   case ARM::t2STMIA_UPD:
1225   case ARM::t2STMDB_UPD:
1226     NeedDisjointWriteback = true;
1227     WritebackReg = Inst.getOperand(0).getReg();
1228     break;
1229   }
1230 
1231   // Empty register lists are not allowed.
1232   if (Val == 0) return MCDisassembler::Fail;
1233   for (unsigned i = 0; i < 16; ++i) {
1234     if (Val & (1 << i)) {
1235       if (!Check(S, DecodeGPRRegisterClass(Inst, i, Address, Decoder)))
1236         return MCDisassembler::Fail;
1237       // Writeback not allowed if Rn is in the target list.
1238       if (NeedDisjointWriteback && WritebackReg == Inst.end()[-1].getReg())
1239         Check(S, MCDisassembler::SoftFail);
1240     }
1241   }
1242 
1243   return S;
1244 }
1245 
1246 static DecodeStatus DecodeSPRRegListOperand(MCInst &Inst, unsigned Val,
1247                                  uint64_t Address, const void *Decoder) {
1248   DecodeStatus S = MCDisassembler::Success;
1249 
1250   unsigned Vd = fieldFromInstruction(Val, 8, 5);
1251   unsigned regs = fieldFromInstruction(Val, 0, 8);
1252 
1253   // In case of unpredictable encoding, tweak the operands.
1254   if (regs == 0 || (Vd + regs) > 32) {
1255     regs = Vd + regs > 32 ? 32 - Vd : regs;
1256     regs = std::max( 1u, regs);
1257     S = MCDisassembler::SoftFail;
1258   }
1259 
1260   if (!Check(S, DecodeSPRRegisterClass(Inst, Vd, Address, Decoder)))
1261     return MCDisassembler::Fail;
1262   for (unsigned i = 0; i < (regs - 1); ++i) {
1263     if (!Check(S, DecodeSPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1264       return MCDisassembler::Fail;
1265   }
1266 
1267   return S;
1268 }
1269 
1270 static DecodeStatus DecodeDPRRegListOperand(MCInst &Inst, unsigned Val,
1271                                  uint64_t Address, const void *Decoder) {
1272   DecodeStatus S = MCDisassembler::Success;
1273 
1274   unsigned Vd = fieldFromInstruction(Val, 8, 5);
1275   unsigned regs = fieldFromInstruction(Val, 1, 7);
1276 
1277   // In case of unpredictable encoding, tweak the operands.
1278   if (regs == 0 || regs > 16 || (Vd + regs) > 32) {
1279     regs = Vd + regs > 32 ? 32 - Vd : regs;
1280     regs = std::max( 1u, regs);
1281     regs = std::min(16u, regs);
1282     S = MCDisassembler::SoftFail;
1283   }
1284 
1285   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
1286       return MCDisassembler::Fail;
1287   for (unsigned i = 0; i < (regs - 1); ++i) {
1288     if (!Check(S, DecodeDPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1289       return MCDisassembler::Fail;
1290   }
1291 
1292   return S;
1293 }
1294 
1295 static DecodeStatus DecodeBitfieldMaskOperand(MCInst &Inst, unsigned Val,
1296                                       uint64_t Address, const void *Decoder) {
1297   // This operand encodes a mask of contiguous zeros between a specified MSB
1298   // and LSB.  To decode it, we create the mask of all bits MSB-and-lower,
1299   // the mask of all bits LSB-and-lower, and then xor them to create
1300   // the mask of that's all ones on [msb, lsb].  Finally we not it to
1301   // create the final mask.
1302   unsigned msb = fieldFromInstruction(Val, 5, 5);
1303   unsigned lsb = fieldFromInstruction(Val, 0, 5);
1304 
1305   DecodeStatus S = MCDisassembler::Success;
1306   if (lsb > msb) {
1307     Check(S, MCDisassembler::SoftFail);
1308     // The check above will cause the warning for the "potentially undefined
1309     // instruction encoding" but we can't build a bad MCOperand value here
1310     // with a lsb > msb or else printing the MCInst will cause a crash.
1311     lsb = msb;
1312   }
1313 
1314   uint32_t msb_mask = 0xFFFFFFFF;
1315   if (msb != 31) msb_mask = (1U << (msb+1)) - 1;
1316   uint32_t lsb_mask = (1U << lsb) - 1;
1317 
1318   Inst.addOperand(MCOperand::createImm(~(msb_mask ^ lsb_mask)));
1319   return S;
1320 }
1321 
1322 static DecodeStatus DecodeCopMemInstruction(MCInst &Inst, unsigned Insn,
1323                                   uint64_t Address, const void *Decoder) {
1324   DecodeStatus S = MCDisassembler::Success;
1325 
1326   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1327   unsigned CRd = fieldFromInstruction(Insn, 12, 4);
1328   unsigned coproc = fieldFromInstruction(Insn, 8, 4);
1329   unsigned imm = fieldFromInstruction(Insn, 0, 8);
1330   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1331   unsigned U = fieldFromInstruction(Insn, 23, 1);
1332 
1333   switch (Inst.getOpcode()) {
1334     case ARM::LDC_OFFSET:
1335     case ARM::LDC_PRE:
1336     case ARM::LDC_POST:
1337     case ARM::LDC_OPTION:
1338     case ARM::LDCL_OFFSET:
1339     case ARM::LDCL_PRE:
1340     case ARM::LDCL_POST:
1341     case ARM::LDCL_OPTION:
1342     case ARM::STC_OFFSET:
1343     case ARM::STC_PRE:
1344     case ARM::STC_POST:
1345     case ARM::STC_OPTION:
1346     case ARM::STCL_OFFSET:
1347     case ARM::STCL_PRE:
1348     case ARM::STCL_POST:
1349     case ARM::STCL_OPTION:
1350     case ARM::t2LDC_OFFSET:
1351     case ARM::t2LDC_PRE:
1352     case ARM::t2LDC_POST:
1353     case ARM::t2LDC_OPTION:
1354     case ARM::t2LDCL_OFFSET:
1355     case ARM::t2LDCL_PRE:
1356     case ARM::t2LDCL_POST:
1357     case ARM::t2LDCL_OPTION:
1358     case ARM::t2STC_OFFSET:
1359     case ARM::t2STC_PRE:
1360     case ARM::t2STC_POST:
1361     case ARM::t2STC_OPTION:
1362     case ARM::t2STCL_OFFSET:
1363     case ARM::t2STCL_PRE:
1364     case ARM::t2STCL_POST:
1365     case ARM::t2STCL_OPTION:
1366       if (coproc == 0xA || coproc == 0xB)
1367         return MCDisassembler::Fail;
1368       break;
1369     default:
1370       break;
1371   }
1372 
1373   const FeatureBitset &featureBits =
1374     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1375   if (featureBits[ARM::HasV8Ops] && (coproc != 14))
1376     return MCDisassembler::Fail;
1377 
1378   Inst.addOperand(MCOperand::createImm(coproc));
1379   Inst.addOperand(MCOperand::createImm(CRd));
1380   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1381     return MCDisassembler::Fail;
1382 
1383   switch (Inst.getOpcode()) {
1384     case ARM::t2LDC2_OFFSET:
1385     case ARM::t2LDC2L_OFFSET:
1386     case ARM::t2LDC2_PRE:
1387     case ARM::t2LDC2L_PRE:
1388     case ARM::t2STC2_OFFSET:
1389     case ARM::t2STC2L_OFFSET:
1390     case ARM::t2STC2_PRE:
1391     case ARM::t2STC2L_PRE:
1392     case ARM::LDC2_OFFSET:
1393     case ARM::LDC2L_OFFSET:
1394     case ARM::LDC2_PRE:
1395     case ARM::LDC2L_PRE:
1396     case ARM::STC2_OFFSET:
1397     case ARM::STC2L_OFFSET:
1398     case ARM::STC2_PRE:
1399     case ARM::STC2L_PRE:
1400     case ARM::t2LDC_OFFSET:
1401     case ARM::t2LDCL_OFFSET:
1402     case ARM::t2LDC_PRE:
1403     case ARM::t2LDCL_PRE:
1404     case ARM::t2STC_OFFSET:
1405     case ARM::t2STCL_OFFSET:
1406     case ARM::t2STC_PRE:
1407     case ARM::t2STCL_PRE:
1408     case ARM::LDC_OFFSET:
1409     case ARM::LDCL_OFFSET:
1410     case ARM::LDC_PRE:
1411     case ARM::LDCL_PRE:
1412     case ARM::STC_OFFSET:
1413     case ARM::STCL_OFFSET:
1414     case ARM::STC_PRE:
1415     case ARM::STCL_PRE:
1416       imm = ARM_AM::getAM5Opc(U ? ARM_AM::add : ARM_AM::sub, imm);
1417       Inst.addOperand(MCOperand::createImm(imm));
1418       break;
1419     case ARM::t2LDC2_POST:
1420     case ARM::t2LDC2L_POST:
1421     case ARM::t2STC2_POST:
1422     case ARM::t2STC2L_POST:
1423     case ARM::LDC2_POST:
1424     case ARM::LDC2L_POST:
1425     case ARM::STC2_POST:
1426     case ARM::STC2L_POST:
1427     case ARM::t2LDC_POST:
1428     case ARM::t2LDCL_POST:
1429     case ARM::t2STC_POST:
1430     case ARM::t2STCL_POST:
1431     case ARM::LDC_POST:
1432     case ARM::LDCL_POST:
1433     case ARM::STC_POST:
1434     case ARM::STCL_POST:
1435       imm |= U << 8;
1436       LLVM_FALLTHROUGH;
1437     default:
1438       // The 'option' variant doesn't encode 'U' in the immediate since
1439       // the immediate is unsigned [0,255].
1440       Inst.addOperand(MCOperand::createImm(imm));
1441       break;
1442   }
1443 
1444   switch (Inst.getOpcode()) {
1445     case ARM::LDC_OFFSET:
1446     case ARM::LDC_PRE:
1447     case ARM::LDC_POST:
1448     case ARM::LDC_OPTION:
1449     case ARM::LDCL_OFFSET:
1450     case ARM::LDCL_PRE:
1451     case ARM::LDCL_POST:
1452     case ARM::LDCL_OPTION:
1453     case ARM::STC_OFFSET:
1454     case ARM::STC_PRE:
1455     case ARM::STC_POST:
1456     case ARM::STC_OPTION:
1457     case ARM::STCL_OFFSET:
1458     case ARM::STCL_PRE:
1459     case ARM::STCL_POST:
1460     case ARM::STCL_OPTION:
1461       if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1462         return MCDisassembler::Fail;
1463       break;
1464     default:
1465       break;
1466   }
1467 
1468   return S;
1469 }
1470 
1471 static DecodeStatus
1472 DecodeAddrMode2IdxInstruction(MCInst &Inst, unsigned Insn,
1473                               uint64_t Address, const void *Decoder) {
1474   DecodeStatus S = MCDisassembler::Success;
1475 
1476   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1477   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
1478   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
1479   unsigned imm = fieldFromInstruction(Insn, 0, 12);
1480   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1481   unsigned reg = fieldFromInstruction(Insn, 25, 1);
1482   unsigned P = fieldFromInstruction(Insn, 24, 1);
1483   unsigned W = fieldFromInstruction(Insn, 21, 1);
1484 
1485   // On stores, the writeback operand precedes Rt.
1486   switch (Inst.getOpcode()) {
1487     case ARM::STR_POST_IMM:
1488     case ARM::STR_POST_REG:
1489     case ARM::STRB_POST_IMM:
1490     case ARM::STRB_POST_REG:
1491     case ARM::STRT_POST_REG:
1492     case ARM::STRT_POST_IMM:
1493     case ARM::STRBT_POST_REG:
1494     case ARM::STRBT_POST_IMM:
1495       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1496         return MCDisassembler::Fail;
1497       break;
1498     default:
1499       break;
1500   }
1501 
1502   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
1503     return MCDisassembler::Fail;
1504 
1505   // On loads, the writeback operand comes after Rt.
1506   switch (Inst.getOpcode()) {
1507     case ARM::LDR_POST_IMM:
1508     case ARM::LDR_POST_REG:
1509     case ARM::LDRB_POST_IMM:
1510     case ARM::LDRB_POST_REG:
1511     case ARM::LDRBT_POST_REG:
1512     case ARM::LDRBT_POST_IMM:
1513     case ARM::LDRT_POST_REG:
1514     case ARM::LDRT_POST_IMM:
1515       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1516         return MCDisassembler::Fail;
1517       break;
1518     default:
1519       break;
1520   }
1521 
1522   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1523     return MCDisassembler::Fail;
1524 
1525   ARM_AM::AddrOpc Op = ARM_AM::add;
1526   if (!fieldFromInstruction(Insn, 23, 1))
1527     Op = ARM_AM::sub;
1528 
1529   bool writeback = (P == 0) || (W == 1);
1530   unsigned idx_mode = 0;
1531   if (P && writeback)
1532     idx_mode = ARMII::IndexModePre;
1533   else if (!P && writeback)
1534     idx_mode = ARMII::IndexModePost;
1535 
1536   if (writeback && (Rn == 15 || Rn == Rt))
1537     S = MCDisassembler::SoftFail; // UNPREDICTABLE
1538 
1539   if (reg) {
1540     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1541       return MCDisassembler::Fail;
1542     ARM_AM::ShiftOpc Opc = ARM_AM::lsl;
1543     switch( fieldFromInstruction(Insn, 5, 2)) {
1544       case 0:
1545         Opc = ARM_AM::lsl;
1546         break;
1547       case 1:
1548         Opc = ARM_AM::lsr;
1549         break;
1550       case 2:
1551         Opc = ARM_AM::asr;
1552         break;
1553       case 3:
1554         Opc = ARM_AM::ror;
1555         break;
1556       default:
1557         return MCDisassembler::Fail;
1558     }
1559     unsigned amt = fieldFromInstruction(Insn, 7, 5);
1560     if (Opc == ARM_AM::ror && amt == 0)
1561       Opc = ARM_AM::rrx;
1562     unsigned imm = ARM_AM::getAM2Opc(Op, amt, Opc, idx_mode);
1563 
1564     Inst.addOperand(MCOperand::createImm(imm));
1565   } else {
1566     Inst.addOperand(MCOperand::createReg(0));
1567     unsigned tmp = ARM_AM::getAM2Opc(Op, imm, ARM_AM::lsl, idx_mode);
1568     Inst.addOperand(MCOperand::createImm(tmp));
1569   }
1570 
1571   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1572     return MCDisassembler::Fail;
1573 
1574   return S;
1575 }
1576 
1577 static DecodeStatus DecodeSORegMemOperand(MCInst &Inst, unsigned Val,
1578                                   uint64_t Address, const void *Decoder) {
1579   DecodeStatus S = MCDisassembler::Success;
1580 
1581   unsigned Rn = fieldFromInstruction(Val, 13, 4);
1582   unsigned Rm = fieldFromInstruction(Val,  0, 4);
1583   unsigned type = fieldFromInstruction(Val, 5, 2);
1584   unsigned imm = fieldFromInstruction(Val, 7, 5);
1585   unsigned U = fieldFromInstruction(Val, 12, 1);
1586 
1587   ARM_AM::ShiftOpc ShOp = ARM_AM::lsl;
1588   switch (type) {
1589     case 0:
1590       ShOp = ARM_AM::lsl;
1591       break;
1592     case 1:
1593       ShOp = ARM_AM::lsr;
1594       break;
1595     case 2:
1596       ShOp = ARM_AM::asr;
1597       break;
1598     case 3:
1599       ShOp = ARM_AM::ror;
1600       break;
1601   }
1602 
1603   if (ShOp == ARM_AM::ror && imm == 0)
1604     ShOp = ARM_AM::rrx;
1605 
1606   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1607     return MCDisassembler::Fail;
1608   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1609     return MCDisassembler::Fail;
1610   unsigned shift;
1611   if (U)
1612     shift = ARM_AM::getAM2Opc(ARM_AM::add, imm, ShOp);
1613   else
1614     shift = ARM_AM::getAM2Opc(ARM_AM::sub, imm, ShOp);
1615   Inst.addOperand(MCOperand::createImm(shift));
1616 
1617   return S;
1618 }
1619 
1620 static DecodeStatus
1621 DecodeAddrMode3Instruction(MCInst &Inst, unsigned Insn,
1622                            uint64_t Address, const void *Decoder) {
1623   DecodeStatus S = MCDisassembler::Success;
1624 
1625   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
1626   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1627   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
1628   unsigned type = fieldFromInstruction(Insn, 22, 1);
1629   unsigned imm = fieldFromInstruction(Insn, 8, 4);
1630   unsigned U = ((~fieldFromInstruction(Insn, 23, 1)) & 1) << 8;
1631   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1632   unsigned W = fieldFromInstruction(Insn, 21, 1);
1633   unsigned P = fieldFromInstruction(Insn, 24, 1);
1634   unsigned Rt2 = Rt + 1;
1635 
1636   bool writeback = (W == 1) | (P == 0);
1637 
1638   // For {LD,ST}RD, Rt must be even, else undefined.
1639   switch (Inst.getOpcode()) {
1640     case ARM::STRD:
1641     case ARM::STRD_PRE:
1642     case ARM::STRD_POST:
1643     case ARM::LDRD:
1644     case ARM::LDRD_PRE:
1645     case ARM::LDRD_POST:
1646       if (Rt & 0x1) S = MCDisassembler::SoftFail;
1647       break;
1648     default:
1649       break;
1650   }
1651   switch (Inst.getOpcode()) {
1652     case ARM::STRD:
1653     case ARM::STRD_PRE:
1654     case ARM::STRD_POST:
1655       if (P == 0 && W == 1)
1656         S = MCDisassembler::SoftFail;
1657 
1658       if (writeback && (Rn == 15 || Rn == Rt || Rn == Rt2))
1659         S = MCDisassembler::SoftFail;
1660       if (type && Rm == 15)
1661         S = MCDisassembler::SoftFail;
1662       if (Rt2 == 15)
1663         S = MCDisassembler::SoftFail;
1664       if (!type && fieldFromInstruction(Insn, 8, 4))
1665         S = MCDisassembler::SoftFail;
1666       break;
1667     case ARM::STRH:
1668     case ARM::STRH_PRE:
1669     case ARM::STRH_POST:
1670       if (Rt == 15)
1671         S = MCDisassembler::SoftFail;
1672       if (writeback && (Rn == 15 || Rn == Rt))
1673         S = MCDisassembler::SoftFail;
1674       if (!type && Rm == 15)
1675         S = MCDisassembler::SoftFail;
1676       break;
1677     case ARM::LDRD:
1678     case ARM::LDRD_PRE:
1679     case ARM::LDRD_POST:
1680       if (type && Rn == 15) {
1681         if (Rt2 == 15)
1682           S = MCDisassembler::SoftFail;
1683         break;
1684       }
1685       if (P == 0 && W == 1)
1686         S = MCDisassembler::SoftFail;
1687       if (!type && (Rt2 == 15 || Rm == 15 || Rm == Rt || Rm == Rt2))
1688         S = MCDisassembler::SoftFail;
1689       if (!type && writeback && Rn == 15)
1690         S = MCDisassembler::SoftFail;
1691       if (writeback && (Rn == Rt || Rn == Rt2))
1692         S = MCDisassembler::SoftFail;
1693       break;
1694     case ARM::LDRH:
1695     case ARM::LDRH_PRE:
1696     case ARM::LDRH_POST:
1697       if (type && Rn == 15) {
1698         if (Rt == 15)
1699           S = MCDisassembler::SoftFail;
1700         break;
1701       }
1702       if (Rt == 15)
1703         S = MCDisassembler::SoftFail;
1704       if (!type && Rm == 15)
1705         S = MCDisassembler::SoftFail;
1706       if (!type && writeback && (Rn == 15 || Rn == Rt))
1707         S = MCDisassembler::SoftFail;
1708       break;
1709     case ARM::LDRSH:
1710     case ARM::LDRSH_PRE:
1711     case ARM::LDRSH_POST:
1712     case ARM::LDRSB:
1713     case ARM::LDRSB_PRE:
1714     case ARM::LDRSB_POST:
1715       if (type && Rn == 15) {
1716         if (Rt == 15)
1717           S = MCDisassembler::SoftFail;
1718         break;
1719       }
1720       if (type && (Rt == 15 || (writeback && Rn == Rt)))
1721         S = MCDisassembler::SoftFail;
1722       if (!type && (Rt == 15 || Rm == 15))
1723         S = MCDisassembler::SoftFail;
1724       if (!type && writeback && (Rn == 15 || Rn == Rt))
1725         S = MCDisassembler::SoftFail;
1726       break;
1727     default:
1728       break;
1729   }
1730 
1731   if (writeback) { // Writeback
1732     if (P)
1733       U |= ARMII::IndexModePre << 9;
1734     else
1735       U |= ARMII::IndexModePost << 9;
1736 
1737     // On stores, the writeback operand precedes Rt.
1738     switch (Inst.getOpcode()) {
1739     case ARM::STRD:
1740     case ARM::STRD_PRE:
1741     case ARM::STRD_POST:
1742     case ARM::STRH:
1743     case ARM::STRH_PRE:
1744     case ARM::STRH_POST:
1745       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1746         return MCDisassembler::Fail;
1747       break;
1748     default:
1749       break;
1750     }
1751   }
1752 
1753   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
1754     return MCDisassembler::Fail;
1755   switch (Inst.getOpcode()) {
1756     case ARM::STRD:
1757     case ARM::STRD_PRE:
1758     case ARM::STRD_POST:
1759     case ARM::LDRD:
1760     case ARM::LDRD_PRE:
1761     case ARM::LDRD_POST:
1762       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder)))
1763         return MCDisassembler::Fail;
1764       break;
1765     default:
1766       break;
1767   }
1768 
1769   if (writeback) {
1770     // On loads, the writeback operand comes after Rt.
1771     switch (Inst.getOpcode()) {
1772     case ARM::LDRD:
1773     case ARM::LDRD_PRE:
1774     case ARM::LDRD_POST:
1775     case ARM::LDRH:
1776     case ARM::LDRH_PRE:
1777     case ARM::LDRH_POST:
1778     case ARM::LDRSH:
1779     case ARM::LDRSH_PRE:
1780     case ARM::LDRSH_POST:
1781     case ARM::LDRSB:
1782     case ARM::LDRSB_PRE:
1783     case ARM::LDRSB_POST:
1784     case ARM::LDRHTr:
1785     case ARM::LDRSBTr:
1786       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1787         return MCDisassembler::Fail;
1788       break;
1789     default:
1790       break;
1791     }
1792   }
1793 
1794   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1795     return MCDisassembler::Fail;
1796 
1797   if (type) {
1798     Inst.addOperand(MCOperand::createReg(0));
1799     Inst.addOperand(MCOperand::createImm(U | (imm << 4) | Rm));
1800   } else {
1801     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1802     return MCDisassembler::Fail;
1803     Inst.addOperand(MCOperand::createImm(U));
1804   }
1805 
1806   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1807     return MCDisassembler::Fail;
1808 
1809   return S;
1810 }
1811 
1812 static DecodeStatus DecodeRFEInstruction(MCInst &Inst, unsigned Insn,
1813                                  uint64_t Address, const void *Decoder) {
1814   DecodeStatus S = MCDisassembler::Success;
1815 
1816   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1817   unsigned mode = fieldFromInstruction(Insn, 23, 2);
1818 
1819   switch (mode) {
1820     case 0:
1821       mode = ARM_AM::da;
1822       break;
1823     case 1:
1824       mode = ARM_AM::ia;
1825       break;
1826     case 2:
1827       mode = ARM_AM::db;
1828       break;
1829     case 3:
1830       mode = ARM_AM::ib;
1831       break;
1832   }
1833 
1834   Inst.addOperand(MCOperand::createImm(mode));
1835   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1836     return MCDisassembler::Fail;
1837 
1838   return S;
1839 }
1840 
1841 static DecodeStatus DecodeQADDInstruction(MCInst &Inst, unsigned Insn,
1842                                uint64_t Address, const void *Decoder) {
1843   DecodeStatus S = MCDisassembler::Success;
1844 
1845   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
1846   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
1847   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1848   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1849 
1850   if (pred == 0xF)
1851     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
1852 
1853   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
1854     return MCDisassembler::Fail;
1855   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1856     return MCDisassembler::Fail;
1857   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
1858     return MCDisassembler::Fail;
1859   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1860     return MCDisassembler::Fail;
1861   return S;
1862 }
1863 
1864 static DecodeStatus DecodeMemMultipleWritebackInstruction(MCInst &Inst,
1865                                   unsigned Insn,
1866                                   uint64_t Address, const void *Decoder) {
1867   DecodeStatus S = MCDisassembler::Success;
1868 
1869   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1870   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1871   unsigned reglist = fieldFromInstruction(Insn, 0, 16);
1872 
1873   if (pred == 0xF) {
1874     // Ambiguous with RFE and SRS
1875     switch (Inst.getOpcode()) {
1876       case ARM::LDMDA:
1877         Inst.setOpcode(ARM::RFEDA);
1878         break;
1879       case ARM::LDMDA_UPD:
1880         Inst.setOpcode(ARM::RFEDA_UPD);
1881         break;
1882       case ARM::LDMDB:
1883         Inst.setOpcode(ARM::RFEDB);
1884         break;
1885       case ARM::LDMDB_UPD:
1886         Inst.setOpcode(ARM::RFEDB_UPD);
1887         break;
1888       case ARM::LDMIA:
1889         Inst.setOpcode(ARM::RFEIA);
1890         break;
1891       case ARM::LDMIA_UPD:
1892         Inst.setOpcode(ARM::RFEIA_UPD);
1893         break;
1894       case ARM::LDMIB:
1895         Inst.setOpcode(ARM::RFEIB);
1896         break;
1897       case ARM::LDMIB_UPD:
1898         Inst.setOpcode(ARM::RFEIB_UPD);
1899         break;
1900       case ARM::STMDA:
1901         Inst.setOpcode(ARM::SRSDA);
1902         break;
1903       case ARM::STMDA_UPD:
1904         Inst.setOpcode(ARM::SRSDA_UPD);
1905         break;
1906       case ARM::STMDB:
1907         Inst.setOpcode(ARM::SRSDB);
1908         break;
1909       case ARM::STMDB_UPD:
1910         Inst.setOpcode(ARM::SRSDB_UPD);
1911         break;
1912       case ARM::STMIA:
1913         Inst.setOpcode(ARM::SRSIA);
1914         break;
1915       case ARM::STMIA_UPD:
1916         Inst.setOpcode(ARM::SRSIA_UPD);
1917         break;
1918       case ARM::STMIB:
1919         Inst.setOpcode(ARM::SRSIB);
1920         break;
1921       case ARM::STMIB_UPD:
1922         Inst.setOpcode(ARM::SRSIB_UPD);
1923         break;
1924       default:
1925         return MCDisassembler::Fail;
1926     }
1927 
1928     // For stores (which become SRS's, the only operand is the mode.
1929     if (fieldFromInstruction(Insn, 20, 1) == 0) {
1930       // Check SRS encoding constraints
1931       if (!(fieldFromInstruction(Insn, 22, 1) == 1 &&
1932             fieldFromInstruction(Insn, 20, 1) == 0))
1933         return MCDisassembler::Fail;
1934 
1935       Inst.addOperand(
1936           MCOperand::createImm(fieldFromInstruction(Insn, 0, 4)));
1937       return S;
1938     }
1939 
1940     return DecodeRFEInstruction(Inst, Insn, Address, Decoder);
1941   }
1942 
1943   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1944     return MCDisassembler::Fail;
1945   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1946     return MCDisassembler::Fail; // Tied
1947   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1948     return MCDisassembler::Fail;
1949   if (!Check(S, DecodeRegListOperand(Inst, reglist, Address, Decoder)))
1950     return MCDisassembler::Fail;
1951 
1952   return S;
1953 }
1954 
1955 // Check for UNPREDICTABLE predicated ESB instruction
1956 static DecodeStatus DecodeHINTInstruction(MCInst &Inst, unsigned Insn,
1957                                  uint64_t Address, const void *Decoder) {
1958   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1959   unsigned imm8 = fieldFromInstruction(Insn, 0, 8);
1960   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
1961   const FeatureBitset &FeatureBits = Dis->getSubtargetInfo().getFeatureBits();
1962 
1963   DecodeStatus S = MCDisassembler::Success;
1964 
1965   Inst.addOperand(MCOperand::createImm(imm8));
1966 
1967   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1968     return MCDisassembler::Fail;
1969 
1970   // ESB is unpredictable if pred != AL. Without the RAS extension, it is a NOP,
1971   // so all predicates should be allowed.
1972   if (imm8 == 0x10 && pred != 0xe && ((FeatureBits[ARM::FeatureRAS]) != 0))
1973     S = MCDisassembler::SoftFail;
1974 
1975   return S;
1976 }
1977 
1978 static DecodeStatus DecodeCPSInstruction(MCInst &Inst, unsigned Insn,
1979                                  uint64_t Address, const void *Decoder) {
1980   unsigned imod = fieldFromInstruction(Insn, 18, 2);
1981   unsigned M = fieldFromInstruction(Insn, 17, 1);
1982   unsigned iflags = fieldFromInstruction(Insn, 6, 3);
1983   unsigned mode = fieldFromInstruction(Insn, 0, 5);
1984 
1985   DecodeStatus S = MCDisassembler::Success;
1986 
1987   // This decoder is called from multiple location that do not check
1988   // the full encoding is valid before they do.
1989   if (fieldFromInstruction(Insn, 5, 1) != 0 ||
1990       fieldFromInstruction(Insn, 16, 1) != 0 ||
1991       fieldFromInstruction(Insn, 20, 8) != 0x10)
1992     return MCDisassembler::Fail;
1993 
1994   // imod == '01' --> UNPREDICTABLE
1995   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
1996   // return failure here.  The '01' imod value is unprintable, so there's
1997   // nothing useful we could do even if we returned UNPREDICTABLE.
1998 
1999   if (imod == 1) return MCDisassembler::Fail;
2000 
2001   if (imod && M) {
2002     Inst.setOpcode(ARM::CPS3p);
2003     Inst.addOperand(MCOperand::createImm(imod));
2004     Inst.addOperand(MCOperand::createImm(iflags));
2005     Inst.addOperand(MCOperand::createImm(mode));
2006   } else if (imod && !M) {
2007     Inst.setOpcode(ARM::CPS2p);
2008     Inst.addOperand(MCOperand::createImm(imod));
2009     Inst.addOperand(MCOperand::createImm(iflags));
2010     if (mode) S = MCDisassembler::SoftFail;
2011   } else if (!imod && M) {
2012     Inst.setOpcode(ARM::CPS1p);
2013     Inst.addOperand(MCOperand::createImm(mode));
2014     if (iflags) S = MCDisassembler::SoftFail;
2015   } else {
2016     // imod == '00' && M == '0' --> UNPREDICTABLE
2017     Inst.setOpcode(ARM::CPS1p);
2018     Inst.addOperand(MCOperand::createImm(mode));
2019     S = MCDisassembler::SoftFail;
2020   }
2021 
2022   return S;
2023 }
2024 
2025 static DecodeStatus DecodeT2CPSInstruction(MCInst &Inst, unsigned Insn,
2026                                  uint64_t Address, const void *Decoder) {
2027   unsigned imod = fieldFromInstruction(Insn, 9, 2);
2028   unsigned M = fieldFromInstruction(Insn, 8, 1);
2029   unsigned iflags = fieldFromInstruction(Insn, 5, 3);
2030   unsigned mode = fieldFromInstruction(Insn, 0, 5);
2031 
2032   DecodeStatus S = MCDisassembler::Success;
2033 
2034   // imod == '01' --> UNPREDICTABLE
2035   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
2036   // return failure here.  The '01' imod value is unprintable, so there's
2037   // nothing useful we could do even if we returned UNPREDICTABLE.
2038 
2039   if (imod == 1) return MCDisassembler::Fail;
2040 
2041   if (imod && M) {
2042     Inst.setOpcode(ARM::t2CPS3p);
2043     Inst.addOperand(MCOperand::createImm(imod));
2044     Inst.addOperand(MCOperand::createImm(iflags));
2045     Inst.addOperand(MCOperand::createImm(mode));
2046   } else if (imod && !M) {
2047     Inst.setOpcode(ARM::t2CPS2p);
2048     Inst.addOperand(MCOperand::createImm(imod));
2049     Inst.addOperand(MCOperand::createImm(iflags));
2050     if (mode) S = MCDisassembler::SoftFail;
2051   } else if (!imod && M) {
2052     Inst.setOpcode(ARM::t2CPS1p);
2053     Inst.addOperand(MCOperand::createImm(mode));
2054     if (iflags) S = MCDisassembler::SoftFail;
2055   } else {
2056     // imod == '00' && M == '0' --> this is a HINT instruction
2057     int imm = fieldFromInstruction(Insn, 0, 8);
2058     // HINT are defined only for immediate in [0..4]
2059     if(imm > 4) return MCDisassembler::Fail;
2060     Inst.setOpcode(ARM::t2HINT);
2061     Inst.addOperand(MCOperand::createImm(imm));
2062   }
2063 
2064   return S;
2065 }
2066 
2067 static DecodeStatus DecodeT2MOVTWInstruction(MCInst &Inst, unsigned Insn,
2068                                  uint64_t Address, const void *Decoder) {
2069   DecodeStatus S = MCDisassembler::Success;
2070 
2071   unsigned Rd = fieldFromInstruction(Insn, 8, 4);
2072   unsigned imm = 0;
2073 
2074   imm |= (fieldFromInstruction(Insn, 0, 8) << 0);
2075   imm |= (fieldFromInstruction(Insn, 12, 3) << 8);
2076   imm |= (fieldFromInstruction(Insn, 16, 4) << 12);
2077   imm |= (fieldFromInstruction(Insn, 26, 1) << 11);
2078 
2079   if (Inst.getOpcode() == ARM::t2MOVTi16)
2080     if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
2081       return MCDisassembler::Fail;
2082   if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
2083     return MCDisassembler::Fail;
2084 
2085   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
2086     Inst.addOperand(MCOperand::createImm(imm));
2087 
2088   return S;
2089 }
2090 
2091 static DecodeStatus DecodeArmMOVTWInstruction(MCInst &Inst, unsigned Insn,
2092                                  uint64_t Address, const void *Decoder) {
2093   DecodeStatus S = MCDisassembler::Success;
2094 
2095   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2096   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2097   unsigned imm = 0;
2098 
2099   imm |= (fieldFromInstruction(Insn, 0, 12) << 0);
2100   imm |= (fieldFromInstruction(Insn, 16, 4) << 12);
2101 
2102   if (Inst.getOpcode() == ARM::MOVTi16)
2103     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2104       return MCDisassembler::Fail;
2105 
2106   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2107     return MCDisassembler::Fail;
2108 
2109   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
2110     Inst.addOperand(MCOperand::createImm(imm));
2111 
2112   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2113     return MCDisassembler::Fail;
2114 
2115   return S;
2116 }
2117 
2118 static DecodeStatus DecodeSMLAInstruction(MCInst &Inst, unsigned Insn,
2119                                  uint64_t Address, const void *Decoder) {
2120   DecodeStatus S = MCDisassembler::Success;
2121 
2122   unsigned Rd = fieldFromInstruction(Insn, 16, 4);
2123   unsigned Rn = fieldFromInstruction(Insn, 0, 4);
2124   unsigned Rm = fieldFromInstruction(Insn, 8, 4);
2125   unsigned Ra = fieldFromInstruction(Insn, 12, 4);
2126   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2127 
2128   if (pred == 0xF)
2129     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
2130 
2131   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2132     return MCDisassembler::Fail;
2133   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
2134     return MCDisassembler::Fail;
2135   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
2136     return MCDisassembler::Fail;
2137   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Ra, Address, Decoder)))
2138     return MCDisassembler::Fail;
2139 
2140   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2141     return MCDisassembler::Fail;
2142 
2143   return S;
2144 }
2145 
2146 static DecodeStatus DecodeTSTInstruction(MCInst &Inst, unsigned Insn,
2147                                   uint64_t Address, const void *Decoder) {
2148   DecodeStatus S = MCDisassembler::Success;
2149 
2150   unsigned Pred = fieldFromInstruction(Insn, 28, 4);
2151   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2152   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2153 
2154   if (Pred == 0xF)
2155     return DecodeSETPANInstruction(Inst, Insn, Address, Decoder);
2156 
2157   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2158     return MCDisassembler::Fail;
2159   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2160     return MCDisassembler::Fail;
2161   if (!Check(S, DecodePredicateOperand(Inst, Pred, Address, Decoder)))
2162     return MCDisassembler::Fail;
2163 
2164   return S;
2165 }
2166 
2167 static DecodeStatus DecodeSETPANInstruction(MCInst &Inst, unsigned Insn,
2168                                   uint64_t Address, const void *Decoder) {
2169   DecodeStatus S = MCDisassembler::Success;
2170 
2171   unsigned Imm = fieldFromInstruction(Insn, 9, 1);
2172 
2173   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
2174   const FeatureBitset &FeatureBits = Dis->getSubtargetInfo().getFeatureBits();
2175 
2176   if (!FeatureBits[ARM::HasV8_1aOps] ||
2177       !FeatureBits[ARM::HasV8Ops])
2178     return MCDisassembler::Fail;
2179 
2180   // Decoder can be called from DecodeTST, which does not check the full
2181   // encoding is valid.
2182   if (fieldFromInstruction(Insn, 20,12) != 0xf11 ||
2183       fieldFromInstruction(Insn, 4,4) != 0)
2184     return MCDisassembler::Fail;
2185   if (fieldFromInstruction(Insn, 10,10) != 0 ||
2186       fieldFromInstruction(Insn, 0,4) != 0)
2187     S = MCDisassembler::SoftFail;
2188 
2189   Inst.setOpcode(ARM::SETPAN);
2190   Inst.addOperand(MCOperand::createImm(Imm));
2191 
2192   return S;
2193 }
2194 
2195 static DecodeStatus DecodeAddrModeImm12Operand(MCInst &Inst, unsigned Val,
2196                            uint64_t Address, const void *Decoder) {
2197   DecodeStatus S = MCDisassembler::Success;
2198 
2199   unsigned add = fieldFromInstruction(Val, 12, 1);
2200   unsigned imm = fieldFromInstruction(Val, 0, 12);
2201   unsigned Rn = fieldFromInstruction(Val, 13, 4);
2202 
2203   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2204     return MCDisassembler::Fail;
2205 
2206   if (!add) imm *= -1;
2207   if (imm == 0 && !add) imm = INT32_MIN;
2208   Inst.addOperand(MCOperand::createImm(imm));
2209   if (Rn == 15)
2210     tryAddingPcLoadReferenceComment(Address, Address + imm + 8, Decoder);
2211 
2212   return S;
2213 }
2214 
2215 static DecodeStatus DecodeAddrMode5Operand(MCInst &Inst, unsigned Val,
2216                                    uint64_t Address, const void *Decoder) {
2217   DecodeStatus S = MCDisassembler::Success;
2218 
2219   unsigned Rn = fieldFromInstruction(Val, 9, 4);
2220   // U == 1 to add imm, 0 to subtract it.
2221   unsigned U = fieldFromInstruction(Val, 8, 1);
2222   unsigned imm = fieldFromInstruction(Val, 0, 8);
2223 
2224   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2225     return MCDisassembler::Fail;
2226 
2227   if (U)
2228     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5Opc(ARM_AM::add, imm)));
2229   else
2230     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5Opc(ARM_AM::sub, imm)));
2231 
2232   return S;
2233 }
2234 
2235 static DecodeStatus DecodeAddrMode5FP16Operand(MCInst &Inst, unsigned Val,
2236                                    uint64_t Address, const void *Decoder) {
2237   DecodeStatus S = MCDisassembler::Success;
2238 
2239   unsigned Rn = fieldFromInstruction(Val, 9, 4);
2240   // U == 1 to add imm, 0 to subtract it.
2241   unsigned U = fieldFromInstruction(Val, 8, 1);
2242   unsigned imm = fieldFromInstruction(Val, 0, 8);
2243 
2244   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2245     return MCDisassembler::Fail;
2246 
2247   if (U)
2248     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5FP16Opc(ARM_AM::add, imm)));
2249   else
2250     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5FP16Opc(ARM_AM::sub, imm)));
2251 
2252   return S;
2253 }
2254 
2255 static DecodeStatus DecodeAddrMode7Operand(MCInst &Inst, unsigned Val,
2256                                    uint64_t Address, const void *Decoder) {
2257   return DecodeGPRRegisterClass(Inst, Val, Address, Decoder);
2258 }
2259 
2260 static DecodeStatus
2261 DecodeT2BInstruction(MCInst &Inst, unsigned Insn,
2262                      uint64_t Address, const void *Decoder) {
2263   DecodeStatus Status = MCDisassembler::Success;
2264 
2265   // Note the J1 and J2 values are from the encoded instruction.  So here
2266   // change them to I1 and I2 values via as documented:
2267   // I1 = NOT(J1 EOR S);
2268   // I2 = NOT(J2 EOR S);
2269   // and build the imm32 with one trailing zero as documented:
2270   // imm32 = SignExtend(S:I1:I2:imm10:imm11:'0', 32);
2271   unsigned S = fieldFromInstruction(Insn, 26, 1);
2272   unsigned J1 = fieldFromInstruction(Insn, 13, 1);
2273   unsigned J2 = fieldFromInstruction(Insn, 11, 1);
2274   unsigned I1 = !(J1 ^ S);
2275   unsigned I2 = !(J2 ^ S);
2276   unsigned imm10 = fieldFromInstruction(Insn, 16, 10);
2277   unsigned imm11 = fieldFromInstruction(Insn, 0, 11);
2278   unsigned tmp = (S << 23) | (I1 << 22) | (I2 << 21) | (imm10 << 11) | imm11;
2279   int imm32 = SignExtend32<25>(tmp << 1);
2280   if (!tryAddingSymbolicOperand(Address, Address + imm32 + 4,
2281                                 true, 4, Inst, Decoder))
2282     Inst.addOperand(MCOperand::createImm(imm32));
2283 
2284   return Status;
2285 }
2286 
2287 static DecodeStatus
2288 DecodeBranchImmInstruction(MCInst &Inst, unsigned Insn,
2289                            uint64_t Address, const void *Decoder) {
2290   DecodeStatus S = MCDisassembler::Success;
2291 
2292   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2293   unsigned imm = fieldFromInstruction(Insn, 0, 24) << 2;
2294 
2295   if (pred == 0xF) {
2296     Inst.setOpcode(ARM::BLXi);
2297     imm |= fieldFromInstruction(Insn, 24, 1) << 1;
2298     if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<26>(imm) + 8,
2299                                   true, 4, Inst, Decoder))
2300     Inst.addOperand(MCOperand::createImm(SignExtend32<26>(imm)));
2301     return S;
2302   }
2303 
2304   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<26>(imm) + 8,
2305                                 true, 4, Inst, Decoder))
2306     Inst.addOperand(MCOperand::createImm(SignExtend32<26>(imm)));
2307   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2308     return MCDisassembler::Fail;
2309 
2310   return S;
2311 }
2312 
2313 static DecodeStatus DecodeAddrMode6Operand(MCInst &Inst, unsigned Val,
2314                                    uint64_t Address, const void *Decoder) {
2315   DecodeStatus S = MCDisassembler::Success;
2316 
2317   unsigned Rm = fieldFromInstruction(Val, 0, 4);
2318   unsigned align = fieldFromInstruction(Val, 4, 2);
2319 
2320   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2321     return MCDisassembler::Fail;
2322   if (!align)
2323     Inst.addOperand(MCOperand::createImm(0));
2324   else
2325     Inst.addOperand(MCOperand::createImm(4 << align));
2326 
2327   return S;
2328 }
2329 
2330 static DecodeStatus DecodeVLDInstruction(MCInst &Inst, unsigned Insn,
2331                                    uint64_t Address, const void *Decoder) {
2332   DecodeStatus S = MCDisassembler::Success;
2333 
2334   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2335   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
2336   unsigned wb = fieldFromInstruction(Insn, 16, 4);
2337   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2338   Rn |= fieldFromInstruction(Insn, 4, 2) << 4;
2339   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2340 
2341   // First output register
2342   switch (Inst.getOpcode()) {
2343   case ARM::VLD1q16: case ARM::VLD1q32: case ARM::VLD1q64: case ARM::VLD1q8:
2344   case ARM::VLD1q16wb_fixed: case ARM::VLD1q16wb_register:
2345   case ARM::VLD1q32wb_fixed: case ARM::VLD1q32wb_register:
2346   case ARM::VLD1q64wb_fixed: case ARM::VLD1q64wb_register:
2347   case ARM::VLD1q8wb_fixed: case ARM::VLD1q8wb_register:
2348   case ARM::VLD2d16: case ARM::VLD2d32: case ARM::VLD2d8:
2349   case ARM::VLD2d16wb_fixed: case ARM::VLD2d16wb_register:
2350   case ARM::VLD2d32wb_fixed: case ARM::VLD2d32wb_register:
2351   case ARM::VLD2d8wb_fixed: case ARM::VLD2d8wb_register:
2352     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
2353       return MCDisassembler::Fail;
2354     break;
2355   case ARM::VLD2b16:
2356   case ARM::VLD2b32:
2357   case ARM::VLD2b8:
2358   case ARM::VLD2b16wb_fixed:
2359   case ARM::VLD2b16wb_register:
2360   case ARM::VLD2b32wb_fixed:
2361   case ARM::VLD2b32wb_register:
2362   case ARM::VLD2b8wb_fixed:
2363   case ARM::VLD2b8wb_register:
2364     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
2365       return MCDisassembler::Fail;
2366     break;
2367   default:
2368     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2369       return MCDisassembler::Fail;
2370   }
2371 
2372   // Second output register
2373   switch (Inst.getOpcode()) {
2374     case ARM::VLD3d8:
2375     case ARM::VLD3d16:
2376     case ARM::VLD3d32:
2377     case ARM::VLD3d8_UPD:
2378     case ARM::VLD3d16_UPD:
2379     case ARM::VLD3d32_UPD:
2380     case ARM::VLD4d8:
2381     case ARM::VLD4d16:
2382     case ARM::VLD4d32:
2383     case ARM::VLD4d8_UPD:
2384     case ARM::VLD4d16_UPD:
2385     case ARM::VLD4d32_UPD:
2386       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
2387         return MCDisassembler::Fail;
2388       break;
2389     case ARM::VLD3q8:
2390     case ARM::VLD3q16:
2391     case ARM::VLD3q32:
2392     case ARM::VLD3q8_UPD:
2393     case ARM::VLD3q16_UPD:
2394     case ARM::VLD3q32_UPD:
2395     case ARM::VLD4q8:
2396     case ARM::VLD4q16:
2397     case ARM::VLD4q32:
2398     case ARM::VLD4q8_UPD:
2399     case ARM::VLD4q16_UPD:
2400     case ARM::VLD4q32_UPD:
2401       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2402         return MCDisassembler::Fail;
2403     default:
2404       break;
2405   }
2406 
2407   // Third output register
2408   switch(Inst.getOpcode()) {
2409     case ARM::VLD3d8:
2410     case ARM::VLD3d16:
2411     case ARM::VLD3d32:
2412     case ARM::VLD3d8_UPD:
2413     case ARM::VLD3d16_UPD:
2414     case ARM::VLD3d32_UPD:
2415     case ARM::VLD4d8:
2416     case ARM::VLD4d16:
2417     case ARM::VLD4d32:
2418     case ARM::VLD4d8_UPD:
2419     case ARM::VLD4d16_UPD:
2420     case ARM::VLD4d32_UPD:
2421       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2422         return MCDisassembler::Fail;
2423       break;
2424     case ARM::VLD3q8:
2425     case ARM::VLD3q16:
2426     case ARM::VLD3q32:
2427     case ARM::VLD3q8_UPD:
2428     case ARM::VLD3q16_UPD:
2429     case ARM::VLD3q32_UPD:
2430     case ARM::VLD4q8:
2431     case ARM::VLD4q16:
2432     case ARM::VLD4q32:
2433     case ARM::VLD4q8_UPD:
2434     case ARM::VLD4q16_UPD:
2435     case ARM::VLD4q32_UPD:
2436       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
2437         return MCDisassembler::Fail;
2438       break;
2439     default:
2440       break;
2441   }
2442 
2443   // Fourth output register
2444   switch (Inst.getOpcode()) {
2445     case ARM::VLD4d8:
2446     case ARM::VLD4d16:
2447     case ARM::VLD4d32:
2448     case ARM::VLD4d8_UPD:
2449     case ARM::VLD4d16_UPD:
2450     case ARM::VLD4d32_UPD:
2451       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
2452         return MCDisassembler::Fail;
2453       break;
2454     case ARM::VLD4q8:
2455     case ARM::VLD4q16:
2456     case ARM::VLD4q32:
2457     case ARM::VLD4q8_UPD:
2458     case ARM::VLD4q16_UPD:
2459     case ARM::VLD4q32_UPD:
2460       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
2461         return MCDisassembler::Fail;
2462       break;
2463     default:
2464       break;
2465   }
2466 
2467   // Writeback operand
2468   switch (Inst.getOpcode()) {
2469     case ARM::VLD1d8wb_fixed:
2470     case ARM::VLD1d16wb_fixed:
2471     case ARM::VLD1d32wb_fixed:
2472     case ARM::VLD1d64wb_fixed:
2473     case ARM::VLD1d8wb_register:
2474     case ARM::VLD1d16wb_register:
2475     case ARM::VLD1d32wb_register:
2476     case ARM::VLD1d64wb_register:
2477     case ARM::VLD1q8wb_fixed:
2478     case ARM::VLD1q16wb_fixed:
2479     case ARM::VLD1q32wb_fixed:
2480     case ARM::VLD1q64wb_fixed:
2481     case ARM::VLD1q8wb_register:
2482     case ARM::VLD1q16wb_register:
2483     case ARM::VLD1q32wb_register:
2484     case ARM::VLD1q64wb_register:
2485     case ARM::VLD1d8Twb_fixed:
2486     case ARM::VLD1d8Twb_register:
2487     case ARM::VLD1d16Twb_fixed:
2488     case ARM::VLD1d16Twb_register:
2489     case ARM::VLD1d32Twb_fixed:
2490     case ARM::VLD1d32Twb_register:
2491     case ARM::VLD1d64Twb_fixed:
2492     case ARM::VLD1d64Twb_register:
2493     case ARM::VLD1d8Qwb_fixed:
2494     case ARM::VLD1d8Qwb_register:
2495     case ARM::VLD1d16Qwb_fixed:
2496     case ARM::VLD1d16Qwb_register:
2497     case ARM::VLD1d32Qwb_fixed:
2498     case ARM::VLD1d32Qwb_register:
2499     case ARM::VLD1d64Qwb_fixed:
2500     case ARM::VLD1d64Qwb_register:
2501     case ARM::VLD2d8wb_fixed:
2502     case ARM::VLD2d16wb_fixed:
2503     case ARM::VLD2d32wb_fixed:
2504     case ARM::VLD2q8wb_fixed:
2505     case ARM::VLD2q16wb_fixed:
2506     case ARM::VLD2q32wb_fixed:
2507     case ARM::VLD2d8wb_register:
2508     case ARM::VLD2d16wb_register:
2509     case ARM::VLD2d32wb_register:
2510     case ARM::VLD2q8wb_register:
2511     case ARM::VLD2q16wb_register:
2512     case ARM::VLD2q32wb_register:
2513     case ARM::VLD2b8wb_fixed:
2514     case ARM::VLD2b16wb_fixed:
2515     case ARM::VLD2b32wb_fixed:
2516     case ARM::VLD2b8wb_register:
2517     case ARM::VLD2b16wb_register:
2518     case ARM::VLD2b32wb_register:
2519       Inst.addOperand(MCOperand::createImm(0));
2520       break;
2521     case ARM::VLD3d8_UPD:
2522     case ARM::VLD3d16_UPD:
2523     case ARM::VLD3d32_UPD:
2524     case ARM::VLD3q8_UPD:
2525     case ARM::VLD3q16_UPD:
2526     case ARM::VLD3q32_UPD:
2527     case ARM::VLD4d8_UPD:
2528     case ARM::VLD4d16_UPD:
2529     case ARM::VLD4d32_UPD:
2530     case ARM::VLD4q8_UPD:
2531     case ARM::VLD4q16_UPD:
2532     case ARM::VLD4q32_UPD:
2533       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
2534         return MCDisassembler::Fail;
2535       break;
2536     default:
2537       break;
2538   }
2539 
2540   // AddrMode6 Base (register+alignment)
2541   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
2542     return MCDisassembler::Fail;
2543 
2544   // AddrMode6 Offset (register)
2545   switch (Inst.getOpcode()) {
2546   default:
2547     // The below have been updated to have explicit am6offset split
2548     // between fixed and register offset. For those instructions not
2549     // yet updated, we need to add an additional reg0 operand for the
2550     // fixed variant.
2551     //
2552     // The fixed offset encodes as Rm == 0xd, so we check for that.
2553     if (Rm == 0xd) {
2554       Inst.addOperand(MCOperand::createReg(0));
2555       break;
2556     }
2557     // Fall through to handle the register offset variant.
2558     LLVM_FALLTHROUGH;
2559   case ARM::VLD1d8wb_fixed:
2560   case ARM::VLD1d16wb_fixed:
2561   case ARM::VLD1d32wb_fixed:
2562   case ARM::VLD1d64wb_fixed:
2563   case ARM::VLD1d8Twb_fixed:
2564   case ARM::VLD1d16Twb_fixed:
2565   case ARM::VLD1d32Twb_fixed:
2566   case ARM::VLD1d64Twb_fixed:
2567   case ARM::VLD1d8Qwb_fixed:
2568   case ARM::VLD1d16Qwb_fixed:
2569   case ARM::VLD1d32Qwb_fixed:
2570   case ARM::VLD1d64Qwb_fixed:
2571   case ARM::VLD1d8wb_register:
2572   case ARM::VLD1d16wb_register:
2573   case ARM::VLD1d32wb_register:
2574   case ARM::VLD1d64wb_register:
2575   case ARM::VLD1q8wb_fixed:
2576   case ARM::VLD1q16wb_fixed:
2577   case ARM::VLD1q32wb_fixed:
2578   case ARM::VLD1q64wb_fixed:
2579   case ARM::VLD1q8wb_register:
2580   case ARM::VLD1q16wb_register:
2581   case ARM::VLD1q32wb_register:
2582   case ARM::VLD1q64wb_register:
2583     // The fixed offset post-increment encodes Rm == 0xd. The no-writeback
2584     // variant encodes Rm == 0xf. Anything else is a register offset post-
2585     // increment and we need to add the register operand to the instruction.
2586     if (Rm != 0xD && Rm != 0xF &&
2587         !Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2588       return MCDisassembler::Fail;
2589     break;
2590   case ARM::VLD2d8wb_fixed:
2591   case ARM::VLD2d16wb_fixed:
2592   case ARM::VLD2d32wb_fixed:
2593   case ARM::VLD2b8wb_fixed:
2594   case ARM::VLD2b16wb_fixed:
2595   case ARM::VLD2b32wb_fixed:
2596   case ARM::VLD2q8wb_fixed:
2597   case ARM::VLD2q16wb_fixed:
2598   case ARM::VLD2q32wb_fixed:
2599     break;
2600   }
2601 
2602   return S;
2603 }
2604 
2605 static DecodeStatus DecodeVLDST1Instruction(MCInst &Inst, unsigned Insn,
2606                                    uint64_t Address, const void *Decoder) {
2607   unsigned type = fieldFromInstruction(Insn, 8, 4);
2608   unsigned align = fieldFromInstruction(Insn, 4, 2);
2609   if (type == 6 && (align & 2)) return MCDisassembler::Fail;
2610   if (type == 7 && (align & 2)) return MCDisassembler::Fail;
2611   if (type == 10 && align == 3) return MCDisassembler::Fail;
2612 
2613   unsigned load = fieldFromInstruction(Insn, 21, 1);
2614   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2615               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2616 }
2617 
2618 static DecodeStatus DecodeVLDST2Instruction(MCInst &Inst, unsigned Insn,
2619                                    uint64_t Address, const void *Decoder) {
2620   unsigned size = fieldFromInstruction(Insn, 6, 2);
2621   if (size == 3) return MCDisassembler::Fail;
2622 
2623   unsigned type = fieldFromInstruction(Insn, 8, 4);
2624   unsigned align = fieldFromInstruction(Insn, 4, 2);
2625   if (type == 8 && align == 3) return MCDisassembler::Fail;
2626   if (type == 9 && align == 3) return MCDisassembler::Fail;
2627 
2628   unsigned load = fieldFromInstruction(Insn, 21, 1);
2629   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2630               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2631 }
2632 
2633 static DecodeStatus DecodeVLDST3Instruction(MCInst &Inst, unsigned Insn,
2634                                    uint64_t Address, const void *Decoder) {
2635   unsigned size = fieldFromInstruction(Insn, 6, 2);
2636   if (size == 3) return MCDisassembler::Fail;
2637 
2638   unsigned align = fieldFromInstruction(Insn, 4, 2);
2639   if (align & 2) return MCDisassembler::Fail;
2640 
2641   unsigned load = fieldFromInstruction(Insn, 21, 1);
2642   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2643               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2644 }
2645 
2646 static DecodeStatus DecodeVLDST4Instruction(MCInst &Inst, unsigned Insn,
2647                                    uint64_t Address, const void *Decoder) {
2648   unsigned size = fieldFromInstruction(Insn, 6, 2);
2649   if (size == 3) return MCDisassembler::Fail;
2650 
2651   unsigned load = fieldFromInstruction(Insn, 21, 1);
2652   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2653               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2654 }
2655 
2656 static DecodeStatus DecodeVSTInstruction(MCInst &Inst, unsigned Insn,
2657                                  uint64_t Address, const void *Decoder) {
2658   DecodeStatus S = MCDisassembler::Success;
2659 
2660   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2661   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
2662   unsigned wb = fieldFromInstruction(Insn, 16, 4);
2663   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2664   Rn |= fieldFromInstruction(Insn, 4, 2) << 4;
2665   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2666 
2667   // Writeback Operand
2668   switch (Inst.getOpcode()) {
2669     case ARM::VST1d8wb_fixed:
2670     case ARM::VST1d16wb_fixed:
2671     case ARM::VST1d32wb_fixed:
2672     case ARM::VST1d64wb_fixed:
2673     case ARM::VST1d8wb_register:
2674     case ARM::VST1d16wb_register:
2675     case ARM::VST1d32wb_register:
2676     case ARM::VST1d64wb_register:
2677     case ARM::VST1q8wb_fixed:
2678     case ARM::VST1q16wb_fixed:
2679     case ARM::VST1q32wb_fixed:
2680     case ARM::VST1q64wb_fixed:
2681     case ARM::VST1q8wb_register:
2682     case ARM::VST1q16wb_register:
2683     case ARM::VST1q32wb_register:
2684     case ARM::VST1q64wb_register:
2685     case ARM::VST1d8Twb_fixed:
2686     case ARM::VST1d16Twb_fixed:
2687     case ARM::VST1d32Twb_fixed:
2688     case ARM::VST1d64Twb_fixed:
2689     case ARM::VST1d8Twb_register:
2690     case ARM::VST1d16Twb_register:
2691     case ARM::VST1d32Twb_register:
2692     case ARM::VST1d64Twb_register:
2693     case ARM::VST1d8Qwb_fixed:
2694     case ARM::VST1d16Qwb_fixed:
2695     case ARM::VST1d32Qwb_fixed:
2696     case ARM::VST1d64Qwb_fixed:
2697     case ARM::VST1d8Qwb_register:
2698     case ARM::VST1d16Qwb_register:
2699     case ARM::VST1d32Qwb_register:
2700     case ARM::VST1d64Qwb_register:
2701     case ARM::VST2d8wb_fixed:
2702     case ARM::VST2d16wb_fixed:
2703     case ARM::VST2d32wb_fixed:
2704     case ARM::VST2d8wb_register:
2705     case ARM::VST2d16wb_register:
2706     case ARM::VST2d32wb_register:
2707     case ARM::VST2q8wb_fixed:
2708     case ARM::VST2q16wb_fixed:
2709     case ARM::VST2q32wb_fixed:
2710     case ARM::VST2q8wb_register:
2711     case ARM::VST2q16wb_register:
2712     case ARM::VST2q32wb_register:
2713     case ARM::VST2b8wb_fixed:
2714     case ARM::VST2b16wb_fixed:
2715     case ARM::VST2b32wb_fixed:
2716     case ARM::VST2b8wb_register:
2717     case ARM::VST2b16wb_register:
2718     case ARM::VST2b32wb_register:
2719       if (Rm == 0xF)
2720         return MCDisassembler::Fail;
2721       Inst.addOperand(MCOperand::createImm(0));
2722       break;
2723     case ARM::VST3d8_UPD:
2724     case ARM::VST3d16_UPD:
2725     case ARM::VST3d32_UPD:
2726     case ARM::VST3q8_UPD:
2727     case ARM::VST3q16_UPD:
2728     case ARM::VST3q32_UPD:
2729     case ARM::VST4d8_UPD:
2730     case ARM::VST4d16_UPD:
2731     case ARM::VST4d32_UPD:
2732     case ARM::VST4q8_UPD:
2733     case ARM::VST4q16_UPD:
2734     case ARM::VST4q32_UPD:
2735       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
2736         return MCDisassembler::Fail;
2737       break;
2738     default:
2739       break;
2740   }
2741 
2742   // AddrMode6 Base (register+alignment)
2743   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
2744     return MCDisassembler::Fail;
2745 
2746   // AddrMode6 Offset (register)
2747   switch (Inst.getOpcode()) {
2748     default:
2749       if (Rm == 0xD)
2750         Inst.addOperand(MCOperand::createReg(0));
2751       else if (Rm != 0xF) {
2752         if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2753           return MCDisassembler::Fail;
2754       }
2755       break;
2756     case ARM::VST1d8wb_fixed:
2757     case ARM::VST1d16wb_fixed:
2758     case ARM::VST1d32wb_fixed:
2759     case ARM::VST1d64wb_fixed:
2760     case ARM::VST1q8wb_fixed:
2761     case ARM::VST1q16wb_fixed:
2762     case ARM::VST1q32wb_fixed:
2763     case ARM::VST1q64wb_fixed:
2764     case ARM::VST1d8Twb_fixed:
2765     case ARM::VST1d16Twb_fixed:
2766     case ARM::VST1d32Twb_fixed:
2767     case ARM::VST1d64Twb_fixed:
2768     case ARM::VST1d8Qwb_fixed:
2769     case ARM::VST1d16Qwb_fixed:
2770     case ARM::VST1d32Qwb_fixed:
2771     case ARM::VST1d64Qwb_fixed:
2772     case ARM::VST2d8wb_fixed:
2773     case ARM::VST2d16wb_fixed:
2774     case ARM::VST2d32wb_fixed:
2775     case ARM::VST2q8wb_fixed:
2776     case ARM::VST2q16wb_fixed:
2777     case ARM::VST2q32wb_fixed:
2778     case ARM::VST2b8wb_fixed:
2779     case ARM::VST2b16wb_fixed:
2780     case ARM::VST2b32wb_fixed:
2781       break;
2782   }
2783 
2784 
2785   // First input register
2786   switch (Inst.getOpcode()) {
2787   case ARM::VST1q16:
2788   case ARM::VST1q32:
2789   case ARM::VST1q64:
2790   case ARM::VST1q8:
2791   case ARM::VST1q16wb_fixed:
2792   case ARM::VST1q16wb_register:
2793   case ARM::VST1q32wb_fixed:
2794   case ARM::VST1q32wb_register:
2795   case ARM::VST1q64wb_fixed:
2796   case ARM::VST1q64wb_register:
2797   case ARM::VST1q8wb_fixed:
2798   case ARM::VST1q8wb_register:
2799   case ARM::VST2d16:
2800   case ARM::VST2d32:
2801   case ARM::VST2d8:
2802   case ARM::VST2d16wb_fixed:
2803   case ARM::VST2d16wb_register:
2804   case ARM::VST2d32wb_fixed:
2805   case ARM::VST2d32wb_register:
2806   case ARM::VST2d8wb_fixed:
2807   case ARM::VST2d8wb_register:
2808     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
2809       return MCDisassembler::Fail;
2810     break;
2811   case ARM::VST2b16:
2812   case ARM::VST2b32:
2813   case ARM::VST2b8:
2814   case ARM::VST2b16wb_fixed:
2815   case ARM::VST2b16wb_register:
2816   case ARM::VST2b32wb_fixed:
2817   case ARM::VST2b32wb_register:
2818   case ARM::VST2b8wb_fixed:
2819   case ARM::VST2b8wb_register:
2820     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
2821       return MCDisassembler::Fail;
2822     break;
2823   default:
2824     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2825       return MCDisassembler::Fail;
2826   }
2827 
2828   // Second input register
2829   switch (Inst.getOpcode()) {
2830     case ARM::VST3d8:
2831     case ARM::VST3d16:
2832     case ARM::VST3d32:
2833     case ARM::VST3d8_UPD:
2834     case ARM::VST3d16_UPD:
2835     case ARM::VST3d32_UPD:
2836     case ARM::VST4d8:
2837     case ARM::VST4d16:
2838     case ARM::VST4d32:
2839     case ARM::VST4d8_UPD:
2840     case ARM::VST4d16_UPD:
2841     case ARM::VST4d32_UPD:
2842       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
2843         return MCDisassembler::Fail;
2844       break;
2845     case ARM::VST3q8:
2846     case ARM::VST3q16:
2847     case ARM::VST3q32:
2848     case ARM::VST3q8_UPD:
2849     case ARM::VST3q16_UPD:
2850     case ARM::VST3q32_UPD:
2851     case ARM::VST4q8:
2852     case ARM::VST4q16:
2853     case ARM::VST4q32:
2854     case ARM::VST4q8_UPD:
2855     case ARM::VST4q16_UPD:
2856     case ARM::VST4q32_UPD:
2857       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2858         return MCDisassembler::Fail;
2859       break;
2860     default:
2861       break;
2862   }
2863 
2864   // Third input register
2865   switch (Inst.getOpcode()) {
2866     case ARM::VST3d8:
2867     case ARM::VST3d16:
2868     case ARM::VST3d32:
2869     case ARM::VST3d8_UPD:
2870     case ARM::VST3d16_UPD:
2871     case ARM::VST3d32_UPD:
2872     case ARM::VST4d8:
2873     case ARM::VST4d16:
2874     case ARM::VST4d32:
2875     case ARM::VST4d8_UPD:
2876     case ARM::VST4d16_UPD:
2877     case ARM::VST4d32_UPD:
2878       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2879         return MCDisassembler::Fail;
2880       break;
2881     case ARM::VST3q8:
2882     case ARM::VST3q16:
2883     case ARM::VST3q32:
2884     case ARM::VST3q8_UPD:
2885     case ARM::VST3q16_UPD:
2886     case ARM::VST3q32_UPD:
2887     case ARM::VST4q8:
2888     case ARM::VST4q16:
2889     case ARM::VST4q32:
2890     case ARM::VST4q8_UPD:
2891     case ARM::VST4q16_UPD:
2892     case ARM::VST4q32_UPD:
2893       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
2894         return MCDisassembler::Fail;
2895       break;
2896     default:
2897       break;
2898   }
2899 
2900   // Fourth input register
2901   switch (Inst.getOpcode()) {
2902     case ARM::VST4d8:
2903     case ARM::VST4d16:
2904     case ARM::VST4d32:
2905     case ARM::VST4d8_UPD:
2906     case ARM::VST4d16_UPD:
2907     case ARM::VST4d32_UPD:
2908       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
2909         return MCDisassembler::Fail;
2910       break;
2911     case ARM::VST4q8:
2912     case ARM::VST4q16:
2913     case ARM::VST4q32:
2914     case ARM::VST4q8_UPD:
2915     case ARM::VST4q16_UPD:
2916     case ARM::VST4q32_UPD:
2917       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
2918         return MCDisassembler::Fail;
2919       break;
2920     default:
2921       break;
2922   }
2923 
2924   return S;
2925 }
2926 
2927 static DecodeStatus DecodeVLD1DupInstruction(MCInst &Inst, unsigned Insn,
2928                                     uint64_t Address, const void *Decoder) {
2929   DecodeStatus S = MCDisassembler::Success;
2930 
2931   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2932   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
2933   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2934   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2935   unsigned align = fieldFromInstruction(Insn, 4, 1);
2936   unsigned size = fieldFromInstruction(Insn, 6, 2);
2937 
2938   if (size == 0 && align == 1)
2939     return MCDisassembler::Fail;
2940   align *= (1 << size);
2941 
2942   switch (Inst.getOpcode()) {
2943   case ARM::VLD1DUPq16: case ARM::VLD1DUPq32: case ARM::VLD1DUPq8:
2944   case ARM::VLD1DUPq16wb_fixed: case ARM::VLD1DUPq16wb_register:
2945   case ARM::VLD1DUPq32wb_fixed: case ARM::VLD1DUPq32wb_register:
2946   case ARM::VLD1DUPq8wb_fixed: case ARM::VLD1DUPq8wb_register:
2947     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
2948       return MCDisassembler::Fail;
2949     break;
2950   default:
2951     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2952       return MCDisassembler::Fail;
2953     break;
2954   }
2955   if (Rm != 0xF) {
2956     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2957       return MCDisassembler::Fail;
2958   }
2959 
2960   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2961     return MCDisassembler::Fail;
2962   Inst.addOperand(MCOperand::createImm(align));
2963 
2964   // The fixed offset post-increment encodes Rm == 0xd. The no-writeback
2965   // variant encodes Rm == 0xf. Anything else is a register offset post-
2966   // increment and we need to add the register operand to the instruction.
2967   if (Rm != 0xD && Rm != 0xF &&
2968       !Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2969     return MCDisassembler::Fail;
2970 
2971   return S;
2972 }
2973 
2974 static DecodeStatus DecodeVLD2DupInstruction(MCInst &Inst, unsigned Insn,
2975                                     uint64_t Address, const void *Decoder) {
2976   DecodeStatus S = MCDisassembler::Success;
2977 
2978   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2979   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
2980   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2981   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2982   unsigned align = fieldFromInstruction(Insn, 4, 1);
2983   unsigned size = 1 << fieldFromInstruction(Insn, 6, 2);
2984   align *= 2*size;
2985 
2986   switch (Inst.getOpcode()) {
2987   case ARM::VLD2DUPd16: case ARM::VLD2DUPd32: case ARM::VLD2DUPd8:
2988   case ARM::VLD2DUPd16wb_fixed: case ARM::VLD2DUPd16wb_register:
2989   case ARM::VLD2DUPd32wb_fixed: case ARM::VLD2DUPd32wb_register:
2990   case ARM::VLD2DUPd8wb_fixed: case ARM::VLD2DUPd8wb_register:
2991     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
2992       return MCDisassembler::Fail;
2993     break;
2994   case ARM::VLD2DUPd16x2: case ARM::VLD2DUPd32x2: case ARM::VLD2DUPd8x2:
2995   case ARM::VLD2DUPd16x2wb_fixed: case ARM::VLD2DUPd16x2wb_register:
2996   case ARM::VLD2DUPd32x2wb_fixed: case ARM::VLD2DUPd32x2wb_register:
2997   case ARM::VLD2DUPd8x2wb_fixed: case ARM::VLD2DUPd8x2wb_register:
2998     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
2999       return MCDisassembler::Fail;
3000     break;
3001   default:
3002     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3003       return MCDisassembler::Fail;
3004     break;
3005   }
3006 
3007   if (Rm != 0xF)
3008     Inst.addOperand(MCOperand::createImm(0));
3009 
3010   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3011     return MCDisassembler::Fail;
3012   Inst.addOperand(MCOperand::createImm(align));
3013 
3014   if (Rm != 0xD && Rm != 0xF) {
3015     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3016       return MCDisassembler::Fail;
3017   }
3018 
3019   return S;
3020 }
3021 
3022 static DecodeStatus DecodeVLD3DupInstruction(MCInst &Inst, unsigned Insn,
3023                                     uint64_t Address, const void *Decoder) {
3024   DecodeStatus S = MCDisassembler::Success;
3025 
3026   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3027   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3028   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3029   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3030   unsigned inc = fieldFromInstruction(Insn, 5, 1) + 1;
3031 
3032   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3033     return MCDisassembler::Fail;
3034   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
3035     return MCDisassembler::Fail;
3036   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
3037     return MCDisassembler::Fail;
3038   if (Rm != 0xF) {
3039     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3040       return MCDisassembler::Fail;
3041   }
3042 
3043   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3044     return MCDisassembler::Fail;
3045   Inst.addOperand(MCOperand::createImm(0));
3046 
3047   if (Rm == 0xD)
3048     Inst.addOperand(MCOperand::createReg(0));
3049   else if (Rm != 0xF) {
3050     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3051       return MCDisassembler::Fail;
3052   }
3053 
3054   return S;
3055 }
3056 
3057 static DecodeStatus DecodeVLD4DupInstruction(MCInst &Inst, unsigned Insn,
3058                                     uint64_t Address, const void *Decoder) {
3059   DecodeStatus S = MCDisassembler::Success;
3060 
3061   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3062   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3063   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3064   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3065   unsigned size = fieldFromInstruction(Insn, 6, 2);
3066   unsigned inc = fieldFromInstruction(Insn, 5, 1) + 1;
3067   unsigned align = fieldFromInstruction(Insn, 4, 1);
3068 
3069   if (size == 0x3) {
3070     if (align == 0)
3071       return MCDisassembler::Fail;
3072     align = 16;
3073   } else {
3074     if (size == 2) {
3075       align *= 8;
3076     } else {
3077       size = 1 << size;
3078       align *= 4*size;
3079     }
3080   }
3081 
3082   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3083     return MCDisassembler::Fail;
3084   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
3085     return MCDisassembler::Fail;
3086   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
3087     return MCDisassembler::Fail;
3088   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3*inc)%32, Address, Decoder)))
3089     return MCDisassembler::Fail;
3090   if (Rm != 0xF) {
3091     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3092       return MCDisassembler::Fail;
3093   }
3094 
3095   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3096     return MCDisassembler::Fail;
3097   Inst.addOperand(MCOperand::createImm(align));
3098 
3099   if (Rm == 0xD)
3100     Inst.addOperand(MCOperand::createReg(0));
3101   else if (Rm != 0xF) {
3102     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3103       return MCDisassembler::Fail;
3104   }
3105 
3106   return S;
3107 }
3108 
3109 static DecodeStatus
3110 DecodeNEONModImmInstruction(MCInst &Inst, unsigned Insn,
3111                             uint64_t Address, const void *Decoder) {
3112   DecodeStatus S = MCDisassembler::Success;
3113 
3114   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3115   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3116   unsigned imm = fieldFromInstruction(Insn, 0, 4);
3117   imm |= fieldFromInstruction(Insn, 16, 3) << 4;
3118   imm |= fieldFromInstruction(Insn, 24, 1) << 7;
3119   imm |= fieldFromInstruction(Insn, 8, 4) << 8;
3120   imm |= fieldFromInstruction(Insn, 5, 1) << 12;
3121   unsigned Q = fieldFromInstruction(Insn, 6, 1);
3122 
3123   if (Q) {
3124     if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3125     return MCDisassembler::Fail;
3126   } else {
3127     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3128     return MCDisassembler::Fail;
3129   }
3130 
3131   Inst.addOperand(MCOperand::createImm(imm));
3132 
3133   switch (Inst.getOpcode()) {
3134     case ARM::VORRiv4i16:
3135     case ARM::VORRiv2i32:
3136     case ARM::VBICiv4i16:
3137     case ARM::VBICiv2i32:
3138       if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3139         return MCDisassembler::Fail;
3140       break;
3141     case ARM::VORRiv8i16:
3142     case ARM::VORRiv4i32:
3143     case ARM::VBICiv8i16:
3144     case ARM::VBICiv4i32:
3145       if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3146         return MCDisassembler::Fail;
3147       break;
3148     default:
3149       break;
3150   }
3151 
3152   return S;
3153 }
3154 
3155 static DecodeStatus DecodeVSHLMaxInstruction(MCInst &Inst, unsigned Insn,
3156                                         uint64_t Address, const void *Decoder) {
3157   DecodeStatus S = MCDisassembler::Success;
3158 
3159   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3160   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3161   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3162   Rm |= fieldFromInstruction(Insn, 5, 1) << 4;
3163   unsigned size = fieldFromInstruction(Insn, 18, 2);
3164 
3165   if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3166     return MCDisassembler::Fail;
3167   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
3168     return MCDisassembler::Fail;
3169   Inst.addOperand(MCOperand::createImm(8 << size));
3170 
3171   return S;
3172 }
3173 
3174 static DecodeStatus DecodeShiftRight8Imm(MCInst &Inst, unsigned Val,
3175                                uint64_t Address, const void *Decoder) {
3176   Inst.addOperand(MCOperand::createImm(8 - Val));
3177   return MCDisassembler::Success;
3178 }
3179 
3180 static DecodeStatus DecodeShiftRight16Imm(MCInst &Inst, unsigned Val,
3181                                uint64_t Address, const void *Decoder) {
3182   Inst.addOperand(MCOperand::createImm(16 - Val));
3183   return MCDisassembler::Success;
3184 }
3185 
3186 static DecodeStatus DecodeShiftRight32Imm(MCInst &Inst, unsigned Val,
3187                                uint64_t Address, const void *Decoder) {
3188   Inst.addOperand(MCOperand::createImm(32 - Val));
3189   return MCDisassembler::Success;
3190 }
3191 
3192 static DecodeStatus DecodeShiftRight64Imm(MCInst &Inst, unsigned Val,
3193                                uint64_t Address, const void *Decoder) {
3194   Inst.addOperand(MCOperand::createImm(64 - Val));
3195   return MCDisassembler::Success;
3196 }
3197 
3198 static DecodeStatus DecodeTBLInstruction(MCInst &Inst, unsigned Insn,
3199                                uint64_t Address, const void *Decoder) {
3200   DecodeStatus S = MCDisassembler::Success;
3201 
3202   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3203   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3204   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3205   Rn |= fieldFromInstruction(Insn, 7, 1) << 4;
3206   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3207   Rm |= fieldFromInstruction(Insn, 5, 1) << 4;
3208   unsigned op = fieldFromInstruction(Insn, 6, 1);
3209 
3210   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3211     return MCDisassembler::Fail;
3212   if (op) {
3213     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3214     return MCDisassembler::Fail; // Writeback
3215   }
3216 
3217   switch (Inst.getOpcode()) {
3218   case ARM::VTBL2:
3219   case ARM::VTBX2:
3220     if (!Check(S, DecodeDPairRegisterClass(Inst, Rn, Address, Decoder)))
3221       return MCDisassembler::Fail;
3222     break;
3223   default:
3224     if (!Check(S, DecodeDPRRegisterClass(Inst, Rn, Address, Decoder)))
3225       return MCDisassembler::Fail;
3226   }
3227 
3228   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
3229     return MCDisassembler::Fail;
3230 
3231   return S;
3232 }
3233 
3234 static DecodeStatus DecodeThumbAddSpecialReg(MCInst &Inst, uint16_t Insn,
3235                                      uint64_t Address, const void *Decoder) {
3236   DecodeStatus S = MCDisassembler::Success;
3237 
3238   unsigned dst = fieldFromInstruction(Insn, 8, 3);
3239   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3240 
3241   if (!Check(S, DecodetGPRRegisterClass(Inst, dst, Address, Decoder)))
3242     return MCDisassembler::Fail;
3243 
3244   switch(Inst.getOpcode()) {
3245     default:
3246       return MCDisassembler::Fail;
3247     case ARM::tADR:
3248       break; // tADR does not explicitly represent the PC as an operand.
3249     case ARM::tADDrSPi:
3250       Inst.addOperand(MCOperand::createReg(ARM::SP));
3251       break;
3252   }
3253 
3254   Inst.addOperand(MCOperand::createImm(imm));
3255   return S;
3256 }
3257 
3258 static DecodeStatus DecodeThumbBROperand(MCInst &Inst, unsigned Val,
3259                                  uint64_t Address, const void *Decoder) {
3260   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<12>(Val<<1) + 4,
3261                                 true, 2, Inst, Decoder))
3262     Inst.addOperand(MCOperand::createImm(SignExtend32<12>(Val << 1)));
3263   return MCDisassembler::Success;
3264 }
3265 
3266 static DecodeStatus DecodeT2BROperand(MCInst &Inst, unsigned Val,
3267                                  uint64_t Address, const void *Decoder) {
3268   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<21>(Val) + 4,
3269                                 true, 4, Inst, Decoder))
3270     Inst.addOperand(MCOperand::createImm(SignExtend32<21>(Val)));
3271   return MCDisassembler::Success;
3272 }
3273 
3274 static DecodeStatus DecodeThumbCmpBROperand(MCInst &Inst, unsigned Val,
3275                                  uint64_t Address, const void *Decoder) {
3276   if (!tryAddingSymbolicOperand(Address, Address + (Val<<1) + 4,
3277                                 true, 2, Inst, Decoder))
3278     Inst.addOperand(MCOperand::createImm(Val << 1));
3279   return MCDisassembler::Success;
3280 }
3281 
3282 static DecodeStatus DecodeThumbAddrModeRR(MCInst &Inst, unsigned Val,
3283                                  uint64_t Address, const void *Decoder) {
3284   DecodeStatus S = MCDisassembler::Success;
3285 
3286   unsigned Rn = fieldFromInstruction(Val, 0, 3);
3287   unsigned Rm = fieldFromInstruction(Val, 3, 3);
3288 
3289   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
3290     return MCDisassembler::Fail;
3291   if (!Check(S, DecodetGPRRegisterClass(Inst, Rm, Address, Decoder)))
3292     return MCDisassembler::Fail;
3293 
3294   return S;
3295 }
3296 
3297 static DecodeStatus DecodeThumbAddrModeIS(MCInst &Inst, unsigned Val,
3298                                   uint64_t Address, const void *Decoder) {
3299   DecodeStatus S = MCDisassembler::Success;
3300 
3301   unsigned Rn = fieldFromInstruction(Val, 0, 3);
3302   unsigned imm = fieldFromInstruction(Val, 3, 5);
3303 
3304   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
3305     return MCDisassembler::Fail;
3306   Inst.addOperand(MCOperand::createImm(imm));
3307 
3308   return S;
3309 }
3310 
3311 static DecodeStatus DecodeThumbAddrModePC(MCInst &Inst, unsigned Val,
3312                                   uint64_t Address, const void *Decoder) {
3313   unsigned imm = Val << 2;
3314 
3315   Inst.addOperand(MCOperand::createImm(imm));
3316   tryAddingPcLoadReferenceComment(Address, (Address & ~2u) + imm + 4, Decoder);
3317 
3318   return MCDisassembler::Success;
3319 }
3320 
3321 static DecodeStatus DecodeThumbAddrModeSP(MCInst &Inst, unsigned Val,
3322                                   uint64_t Address, const void *Decoder) {
3323   Inst.addOperand(MCOperand::createReg(ARM::SP));
3324   Inst.addOperand(MCOperand::createImm(Val));
3325 
3326   return MCDisassembler::Success;
3327 }
3328 
3329 static DecodeStatus DecodeT2AddrModeSOReg(MCInst &Inst, unsigned Val,
3330                                   uint64_t Address, const void *Decoder) {
3331   DecodeStatus S = MCDisassembler::Success;
3332 
3333   unsigned Rn = fieldFromInstruction(Val, 6, 4);
3334   unsigned Rm = fieldFromInstruction(Val, 2, 4);
3335   unsigned imm = fieldFromInstruction(Val, 0, 2);
3336 
3337   // Thumb stores cannot use PC as dest register.
3338   switch (Inst.getOpcode()) {
3339   case ARM::t2STRHs:
3340   case ARM::t2STRBs:
3341   case ARM::t2STRs:
3342     if (Rn == 15)
3343       return MCDisassembler::Fail;
3344   default:
3345     break;
3346   }
3347 
3348   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3349     return MCDisassembler::Fail;
3350   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
3351     return MCDisassembler::Fail;
3352   Inst.addOperand(MCOperand::createImm(imm));
3353 
3354   return S;
3355 }
3356 
3357 static DecodeStatus DecodeT2LoadShift(MCInst &Inst, unsigned Insn,
3358                               uint64_t Address, const void *Decoder) {
3359   DecodeStatus S = MCDisassembler::Success;
3360 
3361   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3362   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3363 
3364   const FeatureBitset &featureBits =
3365     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3366 
3367   bool hasMP = featureBits[ARM::FeatureMP];
3368   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3369 
3370   if (Rn == 15) {
3371     switch (Inst.getOpcode()) {
3372     case ARM::t2LDRBs:
3373       Inst.setOpcode(ARM::t2LDRBpci);
3374       break;
3375     case ARM::t2LDRHs:
3376       Inst.setOpcode(ARM::t2LDRHpci);
3377       break;
3378     case ARM::t2LDRSHs:
3379       Inst.setOpcode(ARM::t2LDRSHpci);
3380       break;
3381     case ARM::t2LDRSBs:
3382       Inst.setOpcode(ARM::t2LDRSBpci);
3383       break;
3384     case ARM::t2LDRs:
3385       Inst.setOpcode(ARM::t2LDRpci);
3386       break;
3387     case ARM::t2PLDs:
3388       Inst.setOpcode(ARM::t2PLDpci);
3389       break;
3390     case ARM::t2PLIs:
3391       Inst.setOpcode(ARM::t2PLIpci);
3392       break;
3393     default:
3394       return MCDisassembler::Fail;
3395     }
3396 
3397     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3398   }
3399 
3400   if (Rt == 15) {
3401     switch (Inst.getOpcode()) {
3402     case ARM::t2LDRSHs:
3403       return MCDisassembler::Fail;
3404     case ARM::t2LDRHs:
3405       Inst.setOpcode(ARM::t2PLDWs);
3406       break;
3407     case ARM::t2LDRSBs:
3408       Inst.setOpcode(ARM::t2PLIs);
3409     default:
3410       break;
3411     }
3412   }
3413 
3414   switch (Inst.getOpcode()) {
3415     case ARM::t2PLDs:
3416       break;
3417     case ARM::t2PLIs:
3418       if (!hasV7Ops)
3419         return MCDisassembler::Fail;
3420       break;
3421     case ARM::t2PLDWs:
3422       if (!hasV7Ops || !hasMP)
3423         return MCDisassembler::Fail;
3424       break;
3425     default:
3426       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3427         return MCDisassembler::Fail;
3428   }
3429 
3430   unsigned addrmode = fieldFromInstruction(Insn, 4, 2);
3431   addrmode |= fieldFromInstruction(Insn, 0, 4) << 2;
3432   addrmode |= fieldFromInstruction(Insn, 16, 4) << 6;
3433   if (!Check(S, DecodeT2AddrModeSOReg(Inst, addrmode, Address, Decoder)))
3434     return MCDisassembler::Fail;
3435 
3436   return S;
3437 }
3438 
3439 static DecodeStatus DecodeT2LoadImm8(MCInst &Inst, unsigned Insn,
3440                                 uint64_t Address, const void* Decoder) {
3441   DecodeStatus S = MCDisassembler::Success;
3442 
3443   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3444   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3445   unsigned U = fieldFromInstruction(Insn, 9, 1);
3446   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3447   imm |= (U << 8);
3448   imm |= (Rn << 9);
3449   unsigned add = fieldFromInstruction(Insn, 9, 1);
3450 
3451   const FeatureBitset &featureBits =
3452     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3453 
3454   bool hasMP = featureBits[ARM::FeatureMP];
3455   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3456 
3457   if (Rn == 15) {
3458     switch (Inst.getOpcode()) {
3459     case ARM::t2LDRi8:
3460       Inst.setOpcode(ARM::t2LDRpci);
3461       break;
3462     case ARM::t2LDRBi8:
3463       Inst.setOpcode(ARM::t2LDRBpci);
3464       break;
3465     case ARM::t2LDRSBi8:
3466       Inst.setOpcode(ARM::t2LDRSBpci);
3467       break;
3468     case ARM::t2LDRHi8:
3469       Inst.setOpcode(ARM::t2LDRHpci);
3470       break;
3471     case ARM::t2LDRSHi8:
3472       Inst.setOpcode(ARM::t2LDRSHpci);
3473       break;
3474     case ARM::t2PLDi8:
3475       Inst.setOpcode(ARM::t2PLDpci);
3476       break;
3477     case ARM::t2PLIi8:
3478       Inst.setOpcode(ARM::t2PLIpci);
3479       break;
3480     default:
3481       return MCDisassembler::Fail;
3482     }
3483     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3484   }
3485 
3486   if (Rt == 15) {
3487     switch (Inst.getOpcode()) {
3488     case ARM::t2LDRSHi8:
3489       return MCDisassembler::Fail;
3490     case ARM::t2LDRHi8:
3491       if (!add)
3492         Inst.setOpcode(ARM::t2PLDWi8);
3493       break;
3494     case ARM::t2LDRSBi8:
3495       Inst.setOpcode(ARM::t2PLIi8);
3496       break;
3497     default:
3498       break;
3499     }
3500   }
3501 
3502   switch (Inst.getOpcode()) {
3503   case ARM::t2PLDi8:
3504     break;
3505   case ARM::t2PLIi8:
3506     if (!hasV7Ops)
3507       return MCDisassembler::Fail;
3508     break;
3509   case ARM::t2PLDWi8:
3510       if (!hasV7Ops || !hasMP)
3511         return MCDisassembler::Fail;
3512       break;
3513   default:
3514     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3515       return MCDisassembler::Fail;
3516   }
3517 
3518   if (!Check(S, DecodeT2AddrModeImm8(Inst, imm, Address, Decoder)))
3519     return MCDisassembler::Fail;
3520   return S;
3521 }
3522 
3523 static DecodeStatus DecodeT2LoadImm12(MCInst &Inst, unsigned Insn,
3524                                 uint64_t Address, const void* Decoder) {
3525   DecodeStatus S = MCDisassembler::Success;
3526 
3527   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3528   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3529   unsigned imm = fieldFromInstruction(Insn, 0, 12);
3530   imm |= (Rn << 13);
3531 
3532   const FeatureBitset &featureBits =
3533     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3534 
3535   bool hasMP = featureBits[ARM::FeatureMP];
3536   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3537 
3538   if (Rn == 15) {
3539     switch (Inst.getOpcode()) {
3540     case ARM::t2LDRi12:
3541       Inst.setOpcode(ARM::t2LDRpci);
3542       break;
3543     case ARM::t2LDRHi12:
3544       Inst.setOpcode(ARM::t2LDRHpci);
3545       break;
3546     case ARM::t2LDRSHi12:
3547       Inst.setOpcode(ARM::t2LDRSHpci);
3548       break;
3549     case ARM::t2LDRBi12:
3550       Inst.setOpcode(ARM::t2LDRBpci);
3551       break;
3552     case ARM::t2LDRSBi12:
3553       Inst.setOpcode(ARM::t2LDRSBpci);
3554       break;
3555     case ARM::t2PLDi12:
3556       Inst.setOpcode(ARM::t2PLDpci);
3557       break;
3558     case ARM::t2PLIi12:
3559       Inst.setOpcode(ARM::t2PLIpci);
3560       break;
3561     default:
3562       return MCDisassembler::Fail;
3563     }
3564     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3565   }
3566 
3567   if (Rt == 15) {
3568     switch (Inst.getOpcode()) {
3569     case ARM::t2LDRSHi12:
3570       return MCDisassembler::Fail;
3571     case ARM::t2LDRHi12:
3572       Inst.setOpcode(ARM::t2PLDWi12);
3573       break;
3574     case ARM::t2LDRSBi12:
3575       Inst.setOpcode(ARM::t2PLIi12);
3576       break;
3577     default:
3578       break;
3579     }
3580   }
3581 
3582   switch (Inst.getOpcode()) {
3583   case ARM::t2PLDi12:
3584     break;
3585   case ARM::t2PLIi12:
3586     if (!hasV7Ops)
3587       return MCDisassembler::Fail;
3588     break;
3589   case ARM::t2PLDWi12:
3590       if (!hasV7Ops || !hasMP)
3591         return MCDisassembler::Fail;
3592       break;
3593   default:
3594     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3595       return MCDisassembler::Fail;
3596   }
3597 
3598   if (!Check(S, DecodeT2AddrModeImm12(Inst, imm, Address, Decoder)))
3599     return MCDisassembler::Fail;
3600   return S;
3601 }
3602 
3603 static DecodeStatus DecodeT2LoadT(MCInst &Inst, unsigned Insn,
3604                                 uint64_t Address, const void* Decoder) {
3605   DecodeStatus S = MCDisassembler::Success;
3606 
3607   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3608   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3609   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3610   imm |= (Rn << 9);
3611 
3612   if (Rn == 15) {
3613     switch (Inst.getOpcode()) {
3614     case ARM::t2LDRT:
3615       Inst.setOpcode(ARM::t2LDRpci);
3616       break;
3617     case ARM::t2LDRBT:
3618       Inst.setOpcode(ARM::t2LDRBpci);
3619       break;
3620     case ARM::t2LDRHT:
3621       Inst.setOpcode(ARM::t2LDRHpci);
3622       break;
3623     case ARM::t2LDRSBT:
3624       Inst.setOpcode(ARM::t2LDRSBpci);
3625       break;
3626     case ARM::t2LDRSHT:
3627       Inst.setOpcode(ARM::t2LDRSHpci);
3628       break;
3629     default:
3630       return MCDisassembler::Fail;
3631     }
3632     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3633   }
3634 
3635   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
3636     return MCDisassembler::Fail;
3637   if (!Check(S, DecodeT2AddrModeImm8(Inst, imm, Address, Decoder)))
3638     return MCDisassembler::Fail;
3639   return S;
3640 }
3641 
3642 static DecodeStatus DecodeT2LoadLabel(MCInst &Inst, unsigned Insn,
3643                                 uint64_t Address, const void* Decoder) {
3644   DecodeStatus S = MCDisassembler::Success;
3645 
3646   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3647   unsigned U = fieldFromInstruction(Insn, 23, 1);
3648   int imm = fieldFromInstruction(Insn, 0, 12);
3649 
3650   const FeatureBitset &featureBits =
3651     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3652 
3653   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3654 
3655   if (Rt == 15) {
3656     switch (Inst.getOpcode()) {
3657       case ARM::t2LDRBpci:
3658       case ARM::t2LDRHpci:
3659         Inst.setOpcode(ARM::t2PLDpci);
3660         break;
3661       case ARM::t2LDRSBpci:
3662         Inst.setOpcode(ARM::t2PLIpci);
3663         break;
3664       case ARM::t2LDRSHpci:
3665         return MCDisassembler::Fail;
3666       default:
3667         break;
3668     }
3669   }
3670 
3671   switch(Inst.getOpcode()) {
3672   case ARM::t2PLDpci:
3673     break;
3674   case ARM::t2PLIpci:
3675     if (!hasV7Ops)
3676       return MCDisassembler::Fail;
3677     break;
3678   default:
3679     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3680       return MCDisassembler::Fail;
3681   }
3682 
3683   if (!U) {
3684     // Special case for #-0.
3685     if (imm == 0)
3686       imm = INT32_MIN;
3687     else
3688       imm = -imm;
3689   }
3690   Inst.addOperand(MCOperand::createImm(imm));
3691 
3692   return S;
3693 }
3694 
3695 static DecodeStatus DecodeT2Imm8S4(MCInst &Inst, unsigned Val,
3696                            uint64_t Address, const void *Decoder) {
3697   if (Val == 0)
3698     Inst.addOperand(MCOperand::createImm(INT32_MIN));
3699   else {
3700     int imm = Val & 0xFF;
3701 
3702     if (!(Val & 0x100)) imm *= -1;
3703     Inst.addOperand(MCOperand::createImm(imm * 4));
3704   }
3705 
3706   return MCDisassembler::Success;
3707 }
3708 
3709 static DecodeStatus DecodeT2AddrModeImm8s4(MCInst &Inst, unsigned Val,
3710                                    uint64_t Address, const void *Decoder) {
3711   DecodeStatus S = MCDisassembler::Success;
3712 
3713   unsigned Rn = fieldFromInstruction(Val, 9, 4);
3714   unsigned imm = fieldFromInstruction(Val, 0, 9);
3715 
3716   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3717     return MCDisassembler::Fail;
3718   if (!Check(S, DecodeT2Imm8S4(Inst, imm, Address, Decoder)))
3719     return MCDisassembler::Fail;
3720 
3721   return S;
3722 }
3723 
3724 static DecodeStatus DecodeT2AddrModeImm0_1020s4(MCInst &Inst,unsigned Val,
3725                                    uint64_t Address, const void *Decoder) {
3726   DecodeStatus S = MCDisassembler::Success;
3727 
3728   unsigned Rn = fieldFromInstruction(Val, 8, 4);
3729   unsigned imm = fieldFromInstruction(Val, 0, 8);
3730 
3731   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
3732     return MCDisassembler::Fail;
3733 
3734   Inst.addOperand(MCOperand::createImm(imm));
3735 
3736   return S;
3737 }
3738 
3739 static DecodeStatus DecodeT2Imm8(MCInst &Inst, unsigned Val,
3740                          uint64_t Address, const void *Decoder) {
3741   int imm = Val & 0xFF;
3742   if (Val == 0)
3743     imm = INT32_MIN;
3744   else if (!(Val & 0x100))
3745     imm *= -1;
3746   Inst.addOperand(MCOperand::createImm(imm));
3747 
3748   return MCDisassembler::Success;
3749 }
3750 
3751 static DecodeStatus DecodeT2AddrModeImm8(MCInst &Inst, unsigned Val,
3752                                  uint64_t Address, const void *Decoder) {
3753   DecodeStatus S = MCDisassembler::Success;
3754 
3755   unsigned Rn = fieldFromInstruction(Val, 9, 4);
3756   unsigned imm = fieldFromInstruction(Val, 0, 9);
3757 
3758   // Thumb stores cannot use PC as dest register.
3759   switch (Inst.getOpcode()) {
3760   case ARM::t2STRT:
3761   case ARM::t2STRBT:
3762   case ARM::t2STRHT:
3763   case ARM::t2STRi8:
3764   case ARM::t2STRHi8:
3765   case ARM::t2STRBi8:
3766     if (Rn == 15)
3767       return MCDisassembler::Fail;
3768     break;
3769   default:
3770     break;
3771   }
3772 
3773   // Some instructions always use an additive offset.
3774   switch (Inst.getOpcode()) {
3775     case ARM::t2LDRT:
3776     case ARM::t2LDRBT:
3777     case ARM::t2LDRHT:
3778     case ARM::t2LDRSBT:
3779     case ARM::t2LDRSHT:
3780     case ARM::t2STRT:
3781     case ARM::t2STRBT:
3782     case ARM::t2STRHT:
3783       imm |= 0x100;
3784       break;
3785     default:
3786       break;
3787   }
3788 
3789   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3790     return MCDisassembler::Fail;
3791   if (!Check(S, DecodeT2Imm8(Inst, imm, Address, Decoder)))
3792     return MCDisassembler::Fail;
3793 
3794   return S;
3795 }
3796 
3797 static DecodeStatus DecodeT2LdStPre(MCInst &Inst, unsigned Insn,
3798                                     uint64_t Address, const void *Decoder) {
3799   DecodeStatus S = MCDisassembler::Success;
3800 
3801   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3802   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3803   unsigned addr = fieldFromInstruction(Insn, 0, 8);
3804   addr |= fieldFromInstruction(Insn, 9, 1) << 8;
3805   addr |= Rn << 9;
3806   unsigned load = fieldFromInstruction(Insn, 20, 1);
3807 
3808   if (Rn == 15) {
3809     switch (Inst.getOpcode()) {
3810     case ARM::t2LDR_PRE:
3811     case ARM::t2LDR_POST:
3812       Inst.setOpcode(ARM::t2LDRpci);
3813       break;
3814     case ARM::t2LDRB_PRE:
3815     case ARM::t2LDRB_POST:
3816       Inst.setOpcode(ARM::t2LDRBpci);
3817       break;
3818     case ARM::t2LDRH_PRE:
3819     case ARM::t2LDRH_POST:
3820       Inst.setOpcode(ARM::t2LDRHpci);
3821       break;
3822     case ARM::t2LDRSB_PRE:
3823     case ARM::t2LDRSB_POST:
3824       if (Rt == 15)
3825         Inst.setOpcode(ARM::t2PLIpci);
3826       else
3827         Inst.setOpcode(ARM::t2LDRSBpci);
3828       break;
3829     case ARM::t2LDRSH_PRE:
3830     case ARM::t2LDRSH_POST:
3831       Inst.setOpcode(ARM::t2LDRSHpci);
3832       break;
3833     default:
3834       return MCDisassembler::Fail;
3835     }
3836     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3837   }
3838 
3839   if (!load) {
3840     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3841       return MCDisassembler::Fail;
3842   }
3843 
3844   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3845     return MCDisassembler::Fail;
3846 
3847   if (load) {
3848     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3849       return MCDisassembler::Fail;
3850   }
3851 
3852   if (!Check(S, DecodeT2AddrModeImm8(Inst, addr, Address, Decoder)))
3853     return MCDisassembler::Fail;
3854 
3855   return S;
3856 }
3857 
3858 static DecodeStatus DecodeT2AddrModeImm12(MCInst &Inst, unsigned Val,
3859                                   uint64_t Address, const void *Decoder) {
3860   DecodeStatus S = MCDisassembler::Success;
3861 
3862   unsigned Rn = fieldFromInstruction(Val, 13, 4);
3863   unsigned imm = fieldFromInstruction(Val, 0, 12);
3864 
3865   // Thumb stores cannot use PC as dest register.
3866   switch (Inst.getOpcode()) {
3867   case ARM::t2STRi12:
3868   case ARM::t2STRBi12:
3869   case ARM::t2STRHi12:
3870     if (Rn == 15)
3871       return MCDisassembler::Fail;
3872   default:
3873     break;
3874   }
3875 
3876   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3877     return MCDisassembler::Fail;
3878   Inst.addOperand(MCOperand::createImm(imm));
3879 
3880   return S;
3881 }
3882 
3883 
3884 static DecodeStatus DecodeThumbAddSPImm(MCInst &Inst, uint16_t Insn,
3885                                 uint64_t Address, const void *Decoder) {
3886   unsigned imm = fieldFromInstruction(Insn, 0, 7);
3887 
3888   Inst.addOperand(MCOperand::createReg(ARM::SP));
3889   Inst.addOperand(MCOperand::createReg(ARM::SP));
3890   Inst.addOperand(MCOperand::createImm(imm));
3891 
3892   return MCDisassembler::Success;
3893 }
3894 
3895 static DecodeStatus DecodeThumbAddSPReg(MCInst &Inst, uint16_t Insn,
3896                                 uint64_t Address, const void *Decoder) {
3897   DecodeStatus S = MCDisassembler::Success;
3898 
3899   if (Inst.getOpcode() == ARM::tADDrSP) {
3900     unsigned Rdm = fieldFromInstruction(Insn, 0, 3);
3901     Rdm |= fieldFromInstruction(Insn, 7, 1) << 3;
3902 
3903     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
3904     return MCDisassembler::Fail;
3905     Inst.addOperand(MCOperand::createReg(ARM::SP));
3906     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
3907     return MCDisassembler::Fail;
3908   } else if (Inst.getOpcode() == ARM::tADDspr) {
3909     unsigned Rm = fieldFromInstruction(Insn, 3, 4);
3910 
3911     Inst.addOperand(MCOperand::createReg(ARM::SP));
3912     Inst.addOperand(MCOperand::createReg(ARM::SP));
3913     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3914     return MCDisassembler::Fail;
3915   }
3916 
3917   return S;
3918 }
3919 
3920 static DecodeStatus DecodeThumbCPS(MCInst &Inst, uint16_t Insn,
3921                            uint64_t Address, const void *Decoder) {
3922   unsigned imod = fieldFromInstruction(Insn, 4, 1) | 0x2;
3923   unsigned flags = fieldFromInstruction(Insn, 0, 3);
3924 
3925   Inst.addOperand(MCOperand::createImm(imod));
3926   Inst.addOperand(MCOperand::createImm(flags));
3927 
3928   return MCDisassembler::Success;
3929 }
3930 
3931 static DecodeStatus DecodePostIdxReg(MCInst &Inst, unsigned Insn,
3932                              uint64_t Address, const void *Decoder) {
3933   DecodeStatus S = MCDisassembler::Success;
3934   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3935   unsigned add = fieldFromInstruction(Insn, 4, 1);
3936 
3937   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
3938     return MCDisassembler::Fail;
3939   Inst.addOperand(MCOperand::createImm(add));
3940 
3941   return S;
3942 }
3943 
3944 static DecodeStatus DecodeThumbBLXOffset(MCInst &Inst, unsigned Val,
3945                                  uint64_t Address, const void *Decoder) {
3946   // Val is passed in as S:J1:J2:imm10H:imm10L:'0'
3947   // Note only one trailing zero not two.  Also the J1 and J2 values are from
3948   // the encoded instruction.  So here change to I1 and I2 values via:
3949   // I1 = NOT(J1 EOR S);
3950   // I2 = NOT(J2 EOR S);
3951   // and build the imm32 with two trailing zeros as documented:
3952   // imm32 = SignExtend(S:I1:I2:imm10H:imm10L:'00', 32);
3953   unsigned S = (Val >> 23) & 1;
3954   unsigned J1 = (Val >> 22) & 1;
3955   unsigned J2 = (Val >> 21) & 1;
3956   unsigned I1 = !(J1 ^ S);
3957   unsigned I2 = !(J2 ^ S);
3958   unsigned tmp = (Val & ~0x600000) | (I1 << 22) | (I2 << 21);
3959   int imm32 = SignExtend32<25>(tmp << 1);
3960 
3961   if (!tryAddingSymbolicOperand(Address,
3962                                 (Address & ~2u) + imm32 + 4,
3963                                 true, 4, Inst, Decoder))
3964     Inst.addOperand(MCOperand::createImm(imm32));
3965   return MCDisassembler::Success;
3966 }
3967 
3968 static DecodeStatus DecodeCoprocessor(MCInst &Inst, unsigned Val,
3969                               uint64_t Address, const void *Decoder) {
3970   if (Val == 0xA || Val == 0xB)
3971     return MCDisassembler::Fail;
3972 
3973   const FeatureBitset &featureBits =
3974     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3975 
3976   if (featureBits[ARM::HasV8Ops] && !(Val == 14 || Val == 15))
3977     return MCDisassembler::Fail;
3978 
3979   Inst.addOperand(MCOperand::createImm(Val));
3980   return MCDisassembler::Success;
3981 }
3982 
3983 static DecodeStatus
3984 DecodeThumbTableBranch(MCInst &Inst, unsigned Insn,
3985                        uint64_t Address, const void *Decoder) {
3986   DecodeStatus S = MCDisassembler::Success;
3987 
3988   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3989   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3990 
3991   if (Rn == ARM::SP) S = MCDisassembler::SoftFail;
3992   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3993     return MCDisassembler::Fail;
3994   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
3995     return MCDisassembler::Fail;
3996   return S;
3997 }
3998 
3999 static DecodeStatus
4000 DecodeThumb2BCCInstruction(MCInst &Inst, unsigned Insn,
4001                            uint64_t Address, const void *Decoder) {
4002   DecodeStatus S = MCDisassembler::Success;
4003 
4004   unsigned pred = fieldFromInstruction(Insn, 22, 4);
4005   if (pred == 0xE || pred == 0xF) {
4006     unsigned opc = fieldFromInstruction(Insn, 4, 28);
4007     switch (opc) {
4008       default:
4009         return MCDisassembler::Fail;
4010       case 0xf3bf8f4:
4011         Inst.setOpcode(ARM::t2DSB);
4012         break;
4013       case 0xf3bf8f5:
4014         Inst.setOpcode(ARM::t2DMB);
4015         break;
4016       case 0xf3bf8f6:
4017         Inst.setOpcode(ARM::t2ISB);
4018         break;
4019     }
4020 
4021     unsigned imm = fieldFromInstruction(Insn, 0, 4);
4022     return DecodeMemBarrierOption(Inst, imm, Address, Decoder);
4023   }
4024 
4025   unsigned brtarget = fieldFromInstruction(Insn, 0, 11) << 1;
4026   brtarget |= fieldFromInstruction(Insn, 11, 1) << 19;
4027   brtarget |= fieldFromInstruction(Insn, 13, 1) << 18;
4028   brtarget |= fieldFromInstruction(Insn, 16, 6) << 12;
4029   brtarget |= fieldFromInstruction(Insn, 26, 1) << 20;
4030 
4031   if (!Check(S, DecodeT2BROperand(Inst, brtarget, Address, Decoder)))
4032     return MCDisassembler::Fail;
4033   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4034     return MCDisassembler::Fail;
4035 
4036   return S;
4037 }
4038 
4039 // Decode a shifted immediate operand.  These basically consist
4040 // of an 8-bit value, and a 4-bit directive that specifies either
4041 // a splat operation or a rotation.
4042 static DecodeStatus DecodeT2SOImm(MCInst &Inst, unsigned Val,
4043                           uint64_t Address, const void *Decoder) {
4044   unsigned ctrl = fieldFromInstruction(Val, 10, 2);
4045   if (ctrl == 0) {
4046     unsigned byte = fieldFromInstruction(Val, 8, 2);
4047     unsigned imm = fieldFromInstruction(Val, 0, 8);
4048     switch (byte) {
4049       case 0:
4050         Inst.addOperand(MCOperand::createImm(imm));
4051         break;
4052       case 1:
4053         Inst.addOperand(MCOperand::createImm((imm << 16) | imm));
4054         break;
4055       case 2:
4056         Inst.addOperand(MCOperand::createImm((imm << 24) | (imm << 8)));
4057         break;
4058       case 3:
4059         Inst.addOperand(MCOperand::createImm((imm << 24) | (imm << 16) |
4060                                              (imm << 8)  |  imm));
4061         break;
4062     }
4063   } else {
4064     unsigned unrot = fieldFromInstruction(Val, 0, 7) | 0x80;
4065     unsigned rot = fieldFromInstruction(Val, 7, 5);
4066     unsigned imm = (unrot >> rot) | (unrot << ((32-rot)&31));
4067     Inst.addOperand(MCOperand::createImm(imm));
4068   }
4069 
4070   return MCDisassembler::Success;
4071 }
4072 
4073 static DecodeStatus
4074 DecodeThumbBCCTargetOperand(MCInst &Inst, unsigned Val,
4075                             uint64_t Address, const void *Decoder) {
4076   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<9>(Val<<1) + 4,
4077                                 true, 2, Inst, Decoder))
4078     Inst.addOperand(MCOperand::createImm(SignExtend32<9>(Val << 1)));
4079   return MCDisassembler::Success;
4080 }
4081 
4082 static DecodeStatus DecodeThumbBLTargetOperand(MCInst &Inst, unsigned Val,
4083                                                uint64_t Address,
4084                                                const void *Decoder) {
4085   // Val is passed in as S:J1:J2:imm10:imm11
4086   // Note no trailing zero after imm11.  Also the J1 and J2 values are from
4087   // the encoded instruction.  So here change to I1 and I2 values via:
4088   // I1 = NOT(J1 EOR S);
4089   // I2 = NOT(J2 EOR S);
4090   // and build the imm32 with one trailing zero as documented:
4091   // imm32 = SignExtend(S:I1:I2:imm10:imm11:'0', 32);
4092   unsigned S = (Val >> 23) & 1;
4093   unsigned J1 = (Val >> 22) & 1;
4094   unsigned J2 = (Val >> 21) & 1;
4095   unsigned I1 = !(J1 ^ S);
4096   unsigned I2 = !(J2 ^ S);
4097   unsigned tmp = (Val & ~0x600000) | (I1 << 22) | (I2 << 21);
4098   int imm32 = SignExtend32<25>(tmp << 1);
4099 
4100   if (!tryAddingSymbolicOperand(Address, Address + imm32 + 4,
4101                                 true, 4, Inst, Decoder))
4102     Inst.addOperand(MCOperand::createImm(imm32));
4103   return MCDisassembler::Success;
4104 }
4105 
4106 static DecodeStatus DecodeMemBarrierOption(MCInst &Inst, unsigned Val,
4107                                    uint64_t Address, const void *Decoder) {
4108   if (Val & ~0xf)
4109     return MCDisassembler::Fail;
4110 
4111   Inst.addOperand(MCOperand::createImm(Val));
4112   return MCDisassembler::Success;
4113 }
4114 
4115 static DecodeStatus DecodeInstSyncBarrierOption(MCInst &Inst, unsigned Val,
4116                                         uint64_t Address, const void *Decoder) {
4117   if (Val & ~0xf)
4118     return MCDisassembler::Fail;
4119 
4120   Inst.addOperand(MCOperand::createImm(Val));
4121   return MCDisassembler::Success;
4122 }
4123 
4124 static DecodeStatus DecodeMSRMask(MCInst &Inst, unsigned Val,
4125                           uint64_t Address, const void *Decoder) {
4126   DecodeStatus S = MCDisassembler::Success;
4127   const FeatureBitset &FeatureBits =
4128     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4129 
4130   if (FeatureBits[ARM::FeatureMClass]) {
4131     unsigned ValLow = Val & 0xff;
4132 
4133     // Validate the SYSm value first.
4134     switch (ValLow) {
4135     case  0: // apsr
4136     case  1: // iapsr
4137     case  2: // eapsr
4138     case  3: // xpsr
4139     case  5: // ipsr
4140     case  6: // epsr
4141     case  7: // iepsr
4142     case  8: // msp
4143     case  9: // psp
4144     case 16: // primask
4145     case 20: // control
4146       break;
4147     case 17: // basepri
4148     case 18: // basepri_max
4149     case 19: // faultmask
4150       if (!(FeatureBits[ARM::HasV7Ops]))
4151         // Values basepri, basepri_max and faultmask are only valid for v7m.
4152         return MCDisassembler::Fail;
4153       break;
4154     case 0x8a: // msplim_ns
4155     case 0x8b: // psplim_ns
4156     case 0x91: // basepri_ns
4157     case 0x92: // basepri_max_ns
4158     case 0x93: // faultmask_ns
4159       if (!(FeatureBits[ARM::HasV8MMainlineOps]))
4160         return MCDisassembler::Fail;
4161       LLVM_FALLTHROUGH;
4162     case 10:   // msplim
4163     case 11:   // psplim
4164     case 0x88: // msp_ns
4165     case 0x89: // psp_ns
4166     case 0x90: // primask_ns
4167     case 0x94: // control_ns
4168     case 0x98: // sp_ns
4169       if (!(FeatureBits[ARM::Feature8MSecExt]))
4170         return MCDisassembler::Fail;
4171       break;
4172     default:
4173       return MCDisassembler::Fail;
4174     }
4175 
4176     if (Inst.getOpcode() == ARM::t2MSR_M) {
4177       unsigned Mask = fieldFromInstruction(Val, 10, 2);
4178       if (!(FeatureBits[ARM::HasV7Ops])) {
4179         // The ARMv6-M MSR bits {11-10} can be only 0b10, other values are
4180         // unpredictable.
4181         if (Mask != 2)
4182           S = MCDisassembler::SoftFail;
4183       }
4184       else {
4185         // The ARMv7-M architecture stores an additional 2-bit mask value in
4186         // MSR bits {11-10}. The mask is used only with apsr, iapsr, eapsr and
4187         // xpsr, it has to be 0b10 in other cases. Bit mask{1} indicates if
4188         // the NZCVQ bits should be moved by the instruction. Bit mask{0}
4189         // indicates the move for the GE{3:0} bits, the mask{0} bit can be set
4190         // only if the processor includes the DSP extension.
4191         if (Mask == 0 || (Mask != 2 && ValLow > 3) ||
4192             (!(FeatureBits[ARM::FeatureDSP]) && (Mask & 1)))
4193           S = MCDisassembler::SoftFail;
4194       }
4195     }
4196   } else {
4197     // A/R class
4198     if (Val == 0)
4199       return MCDisassembler::Fail;
4200   }
4201   Inst.addOperand(MCOperand::createImm(Val));
4202   return S;
4203 }
4204 
4205 static DecodeStatus DecodeBankedReg(MCInst &Inst, unsigned Val,
4206                                     uint64_t Address, const void *Decoder) {
4207 
4208   unsigned R = fieldFromInstruction(Val, 5, 1);
4209   unsigned SysM = fieldFromInstruction(Val, 0, 5);
4210 
4211   // The table of encodings for these banked registers comes from B9.2.3 of the
4212   // ARM ARM. There are patterns, but nothing regular enough to make this logic
4213   // neater. So by fiat, these values are UNPREDICTABLE:
4214   if (!R) {
4215     if (SysM == 0x7 || SysM == 0xf || SysM == 0x18 || SysM == 0x19 ||
4216         SysM == 0x1a || SysM == 0x1b)
4217       return MCDisassembler::SoftFail;
4218   } else {
4219     if (SysM != 0xe && SysM != 0x10 && SysM != 0x12 && SysM != 0x14 &&
4220         SysM != 0x16 && SysM != 0x1c && SysM != 0x1e)
4221       return MCDisassembler::SoftFail;
4222   }
4223 
4224   Inst.addOperand(MCOperand::createImm(Val));
4225   return MCDisassembler::Success;
4226 }
4227 
4228 static DecodeStatus DecodeDoubleRegLoad(MCInst &Inst, unsigned Insn,
4229                                         uint64_t Address, const void *Decoder) {
4230   DecodeStatus S = MCDisassembler::Success;
4231 
4232   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4233   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4234   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4235 
4236   if (Rn == 0xF)
4237     S = MCDisassembler::SoftFail;
4238 
4239   if (!Check(S, DecodeGPRPairRegisterClass(Inst, Rt, Address, Decoder)))
4240     return MCDisassembler::Fail;
4241   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4242     return MCDisassembler::Fail;
4243   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4244     return MCDisassembler::Fail;
4245 
4246   return S;
4247 }
4248 
4249 static DecodeStatus DecodeDoubleRegStore(MCInst &Inst, unsigned Insn,
4250                                          uint64_t Address,
4251                                          const void *Decoder) {
4252   DecodeStatus S = MCDisassembler::Success;
4253 
4254   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4255   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
4256   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4257   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4258 
4259   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
4260     return MCDisassembler::Fail;
4261 
4262   if (Rn == 0xF || Rd == Rn || Rd == Rt || Rd == Rt+1)
4263     S = MCDisassembler::SoftFail;
4264 
4265   if (!Check(S, DecodeGPRPairRegisterClass(Inst, Rt, Address, Decoder)))
4266     return MCDisassembler::Fail;
4267   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4268     return MCDisassembler::Fail;
4269   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4270     return MCDisassembler::Fail;
4271 
4272   return S;
4273 }
4274 
4275 static DecodeStatus DecodeLDRPreImm(MCInst &Inst, unsigned Insn,
4276                             uint64_t Address, const void *Decoder) {
4277   DecodeStatus S = MCDisassembler::Success;
4278 
4279   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4280   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4281   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4282   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4283   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4284   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4285 
4286   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4287 
4288   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4289     return MCDisassembler::Fail;
4290   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4291     return MCDisassembler::Fail;
4292   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
4293     return MCDisassembler::Fail;
4294   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4295     return MCDisassembler::Fail;
4296 
4297   return S;
4298 }
4299 
4300 static DecodeStatus DecodeLDRPreReg(MCInst &Inst, unsigned Insn,
4301                             uint64_t Address, const void *Decoder) {
4302   DecodeStatus S = MCDisassembler::Success;
4303 
4304   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4305   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4306   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4307   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4308   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4309   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4310   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4311 
4312   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4313   if (Rm == 0xF) S = MCDisassembler::SoftFail;
4314 
4315   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4316     return MCDisassembler::Fail;
4317   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4318     return MCDisassembler::Fail;
4319   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
4320     return MCDisassembler::Fail;
4321   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4322     return MCDisassembler::Fail;
4323 
4324   return S;
4325 }
4326 
4327 static DecodeStatus DecodeSTRPreImm(MCInst &Inst, unsigned Insn,
4328                             uint64_t Address, const void *Decoder) {
4329   DecodeStatus S = MCDisassembler::Success;
4330 
4331   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4332   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4333   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4334   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4335   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4336   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4337 
4338   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4339 
4340   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4341     return MCDisassembler::Fail;
4342   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4343     return MCDisassembler::Fail;
4344   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
4345     return MCDisassembler::Fail;
4346   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4347     return MCDisassembler::Fail;
4348 
4349   return S;
4350 }
4351 
4352 static DecodeStatus DecodeSTRPreReg(MCInst &Inst, unsigned Insn,
4353                             uint64_t Address, const void *Decoder) {
4354   DecodeStatus S = MCDisassembler::Success;
4355 
4356   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4357   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4358   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4359   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4360   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4361   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4362 
4363   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4364 
4365   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4366     return MCDisassembler::Fail;
4367   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4368     return MCDisassembler::Fail;
4369   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
4370     return MCDisassembler::Fail;
4371   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4372     return MCDisassembler::Fail;
4373 
4374   return S;
4375 }
4376 
4377 static DecodeStatus DecodeVLD1LN(MCInst &Inst, unsigned Insn,
4378                          uint64_t Address, const void *Decoder) {
4379   DecodeStatus S = MCDisassembler::Success;
4380 
4381   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4382   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4383   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4384   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4385   unsigned size = fieldFromInstruction(Insn, 10, 2);
4386 
4387   unsigned align = 0;
4388   unsigned index = 0;
4389   switch (size) {
4390     default:
4391       return MCDisassembler::Fail;
4392     case 0:
4393       if (fieldFromInstruction(Insn, 4, 1))
4394         return MCDisassembler::Fail; // UNDEFINED
4395       index = fieldFromInstruction(Insn, 5, 3);
4396       break;
4397     case 1:
4398       if (fieldFromInstruction(Insn, 5, 1))
4399         return MCDisassembler::Fail; // UNDEFINED
4400       index = fieldFromInstruction(Insn, 6, 2);
4401       if (fieldFromInstruction(Insn, 4, 1))
4402         align = 2;
4403       break;
4404     case 2:
4405       if (fieldFromInstruction(Insn, 6, 1))
4406         return MCDisassembler::Fail; // UNDEFINED
4407       index = fieldFromInstruction(Insn, 7, 1);
4408 
4409       switch (fieldFromInstruction(Insn, 4, 2)) {
4410         case 0 :
4411           align = 0; break;
4412         case 3:
4413           align = 4; break;
4414         default:
4415           return MCDisassembler::Fail;
4416       }
4417       break;
4418   }
4419 
4420   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4421     return MCDisassembler::Fail;
4422   if (Rm != 0xF) { // Writeback
4423     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4424       return MCDisassembler::Fail;
4425   }
4426   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4427     return MCDisassembler::Fail;
4428   Inst.addOperand(MCOperand::createImm(align));
4429   if (Rm != 0xF) {
4430     if (Rm != 0xD) {
4431       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4432         return MCDisassembler::Fail;
4433     } else
4434       Inst.addOperand(MCOperand::createReg(0));
4435   }
4436 
4437   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4438     return MCDisassembler::Fail;
4439   Inst.addOperand(MCOperand::createImm(index));
4440 
4441   return S;
4442 }
4443 
4444 static DecodeStatus DecodeVST1LN(MCInst &Inst, unsigned Insn,
4445                          uint64_t Address, const void *Decoder) {
4446   DecodeStatus S = MCDisassembler::Success;
4447 
4448   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4449   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4450   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4451   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4452   unsigned size = fieldFromInstruction(Insn, 10, 2);
4453 
4454   unsigned align = 0;
4455   unsigned index = 0;
4456   switch (size) {
4457     default:
4458       return MCDisassembler::Fail;
4459     case 0:
4460       if (fieldFromInstruction(Insn, 4, 1))
4461         return MCDisassembler::Fail; // UNDEFINED
4462       index = fieldFromInstruction(Insn, 5, 3);
4463       break;
4464     case 1:
4465       if (fieldFromInstruction(Insn, 5, 1))
4466         return MCDisassembler::Fail; // UNDEFINED
4467       index = fieldFromInstruction(Insn, 6, 2);
4468       if (fieldFromInstruction(Insn, 4, 1))
4469         align = 2;
4470       break;
4471     case 2:
4472       if (fieldFromInstruction(Insn, 6, 1))
4473         return MCDisassembler::Fail; // UNDEFINED
4474       index = fieldFromInstruction(Insn, 7, 1);
4475 
4476       switch (fieldFromInstruction(Insn, 4, 2)) {
4477         case 0:
4478           align = 0; break;
4479         case 3:
4480           align = 4; break;
4481         default:
4482           return MCDisassembler::Fail;
4483       }
4484       break;
4485   }
4486 
4487   if (Rm != 0xF) { // Writeback
4488     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4489     return MCDisassembler::Fail;
4490   }
4491   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4492     return MCDisassembler::Fail;
4493   Inst.addOperand(MCOperand::createImm(align));
4494   if (Rm != 0xF) {
4495     if (Rm != 0xD) {
4496       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4497     return MCDisassembler::Fail;
4498     } else
4499       Inst.addOperand(MCOperand::createReg(0));
4500   }
4501 
4502   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4503     return MCDisassembler::Fail;
4504   Inst.addOperand(MCOperand::createImm(index));
4505 
4506   return S;
4507 }
4508 
4509 static DecodeStatus DecodeVLD2LN(MCInst &Inst, unsigned Insn,
4510                          uint64_t Address, const void *Decoder) {
4511   DecodeStatus S = MCDisassembler::Success;
4512 
4513   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4514   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4515   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4516   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4517   unsigned size = fieldFromInstruction(Insn, 10, 2);
4518 
4519   unsigned align = 0;
4520   unsigned index = 0;
4521   unsigned inc = 1;
4522   switch (size) {
4523     default:
4524       return MCDisassembler::Fail;
4525     case 0:
4526       index = fieldFromInstruction(Insn, 5, 3);
4527       if (fieldFromInstruction(Insn, 4, 1))
4528         align = 2;
4529       break;
4530     case 1:
4531       index = fieldFromInstruction(Insn, 6, 2);
4532       if (fieldFromInstruction(Insn, 4, 1))
4533         align = 4;
4534       if (fieldFromInstruction(Insn, 5, 1))
4535         inc = 2;
4536       break;
4537     case 2:
4538       if (fieldFromInstruction(Insn, 5, 1))
4539         return MCDisassembler::Fail; // UNDEFINED
4540       index = fieldFromInstruction(Insn, 7, 1);
4541       if (fieldFromInstruction(Insn, 4, 1) != 0)
4542         align = 8;
4543       if (fieldFromInstruction(Insn, 6, 1))
4544         inc = 2;
4545       break;
4546   }
4547 
4548   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4549     return MCDisassembler::Fail;
4550   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4551     return MCDisassembler::Fail;
4552   if (Rm != 0xF) { // Writeback
4553     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4554       return MCDisassembler::Fail;
4555   }
4556   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4557     return MCDisassembler::Fail;
4558   Inst.addOperand(MCOperand::createImm(align));
4559   if (Rm != 0xF) {
4560     if (Rm != 0xD) {
4561       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4562         return MCDisassembler::Fail;
4563     } else
4564       Inst.addOperand(MCOperand::createReg(0));
4565   }
4566 
4567   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4568     return MCDisassembler::Fail;
4569   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4570     return MCDisassembler::Fail;
4571   Inst.addOperand(MCOperand::createImm(index));
4572 
4573   return S;
4574 }
4575 
4576 static DecodeStatus DecodeVST2LN(MCInst &Inst, unsigned Insn,
4577                          uint64_t Address, const void *Decoder) {
4578   DecodeStatus S = MCDisassembler::Success;
4579 
4580   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4581   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4582   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4583   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4584   unsigned size = fieldFromInstruction(Insn, 10, 2);
4585 
4586   unsigned align = 0;
4587   unsigned index = 0;
4588   unsigned inc = 1;
4589   switch (size) {
4590     default:
4591       return MCDisassembler::Fail;
4592     case 0:
4593       index = fieldFromInstruction(Insn, 5, 3);
4594       if (fieldFromInstruction(Insn, 4, 1))
4595         align = 2;
4596       break;
4597     case 1:
4598       index = fieldFromInstruction(Insn, 6, 2);
4599       if (fieldFromInstruction(Insn, 4, 1))
4600         align = 4;
4601       if (fieldFromInstruction(Insn, 5, 1))
4602         inc = 2;
4603       break;
4604     case 2:
4605       if (fieldFromInstruction(Insn, 5, 1))
4606         return MCDisassembler::Fail; // UNDEFINED
4607       index = fieldFromInstruction(Insn, 7, 1);
4608       if (fieldFromInstruction(Insn, 4, 1) != 0)
4609         align = 8;
4610       if (fieldFromInstruction(Insn, 6, 1))
4611         inc = 2;
4612       break;
4613   }
4614 
4615   if (Rm != 0xF) { // Writeback
4616     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4617       return MCDisassembler::Fail;
4618   }
4619   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4620     return MCDisassembler::Fail;
4621   Inst.addOperand(MCOperand::createImm(align));
4622   if (Rm != 0xF) {
4623     if (Rm != 0xD) {
4624       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4625         return MCDisassembler::Fail;
4626     } else
4627       Inst.addOperand(MCOperand::createReg(0));
4628   }
4629 
4630   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4631     return MCDisassembler::Fail;
4632   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4633     return MCDisassembler::Fail;
4634   Inst.addOperand(MCOperand::createImm(index));
4635 
4636   return S;
4637 }
4638 
4639 static DecodeStatus DecodeVLD3LN(MCInst &Inst, unsigned Insn,
4640                          uint64_t Address, const void *Decoder) {
4641   DecodeStatus S = MCDisassembler::Success;
4642 
4643   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4644   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4645   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4646   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4647   unsigned size = fieldFromInstruction(Insn, 10, 2);
4648 
4649   unsigned align = 0;
4650   unsigned index = 0;
4651   unsigned inc = 1;
4652   switch (size) {
4653     default:
4654       return MCDisassembler::Fail;
4655     case 0:
4656       if (fieldFromInstruction(Insn, 4, 1))
4657         return MCDisassembler::Fail; // UNDEFINED
4658       index = fieldFromInstruction(Insn, 5, 3);
4659       break;
4660     case 1:
4661       if (fieldFromInstruction(Insn, 4, 1))
4662         return MCDisassembler::Fail; // UNDEFINED
4663       index = fieldFromInstruction(Insn, 6, 2);
4664       if (fieldFromInstruction(Insn, 5, 1))
4665         inc = 2;
4666       break;
4667     case 2:
4668       if (fieldFromInstruction(Insn, 4, 2))
4669         return MCDisassembler::Fail; // UNDEFINED
4670       index = fieldFromInstruction(Insn, 7, 1);
4671       if (fieldFromInstruction(Insn, 6, 1))
4672         inc = 2;
4673       break;
4674   }
4675 
4676   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4677     return MCDisassembler::Fail;
4678   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4679     return MCDisassembler::Fail;
4680   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
4681     return MCDisassembler::Fail;
4682 
4683   if (Rm != 0xF) { // Writeback
4684     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4685     return MCDisassembler::Fail;
4686   }
4687   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4688     return MCDisassembler::Fail;
4689   Inst.addOperand(MCOperand::createImm(align));
4690   if (Rm != 0xF) {
4691     if (Rm != 0xD) {
4692       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4693     return MCDisassembler::Fail;
4694     } else
4695       Inst.addOperand(MCOperand::createReg(0));
4696   }
4697 
4698   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4699     return MCDisassembler::Fail;
4700   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4701     return MCDisassembler::Fail;
4702   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
4703     return MCDisassembler::Fail;
4704   Inst.addOperand(MCOperand::createImm(index));
4705 
4706   return S;
4707 }
4708 
4709 static DecodeStatus DecodeVST3LN(MCInst &Inst, unsigned Insn,
4710                          uint64_t Address, const void *Decoder) {
4711   DecodeStatus S = MCDisassembler::Success;
4712 
4713   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4714   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4715   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4716   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4717   unsigned size = fieldFromInstruction(Insn, 10, 2);
4718 
4719   unsigned align = 0;
4720   unsigned index = 0;
4721   unsigned inc = 1;
4722   switch (size) {
4723     default:
4724       return MCDisassembler::Fail;
4725     case 0:
4726       if (fieldFromInstruction(Insn, 4, 1))
4727         return MCDisassembler::Fail; // UNDEFINED
4728       index = fieldFromInstruction(Insn, 5, 3);
4729       break;
4730     case 1:
4731       if (fieldFromInstruction(Insn, 4, 1))
4732         return MCDisassembler::Fail; // UNDEFINED
4733       index = fieldFromInstruction(Insn, 6, 2);
4734       if (fieldFromInstruction(Insn, 5, 1))
4735         inc = 2;
4736       break;
4737     case 2:
4738       if (fieldFromInstruction(Insn, 4, 2))
4739         return MCDisassembler::Fail; // UNDEFINED
4740       index = fieldFromInstruction(Insn, 7, 1);
4741       if (fieldFromInstruction(Insn, 6, 1))
4742         inc = 2;
4743       break;
4744   }
4745 
4746   if (Rm != 0xF) { // Writeback
4747     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4748     return MCDisassembler::Fail;
4749   }
4750   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4751     return MCDisassembler::Fail;
4752   Inst.addOperand(MCOperand::createImm(align));
4753   if (Rm != 0xF) {
4754     if (Rm != 0xD) {
4755       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4756     return MCDisassembler::Fail;
4757     } else
4758       Inst.addOperand(MCOperand::createReg(0));
4759   }
4760 
4761   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4762     return MCDisassembler::Fail;
4763   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4764     return MCDisassembler::Fail;
4765   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
4766     return MCDisassembler::Fail;
4767   Inst.addOperand(MCOperand::createImm(index));
4768 
4769   return S;
4770 }
4771 
4772 static DecodeStatus DecodeVLD4LN(MCInst &Inst, unsigned Insn,
4773                          uint64_t Address, const void *Decoder) {
4774   DecodeStatus S = MCDisassembler::Success;
4775 
4776   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4777   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4778   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4779   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4780   unsigned size = fieldFromInstruction(Insn, 10, 2);
4781 
4782   unsigned align = 0;
4783   unsigned index = 0;
4784   unsigned inc = 1;
4785   switch (size) {
4786     default:
4787       return MCDisassembler::Fail;
4788     case 0:
4789       if (fieldFromInstruction(Insn, 4, 1))
4790         align = 4;
4791       index = fieldFromInstruction(Insn, 5, 3);
4792       break;
4793     case 1:
4794       if (fieldFromInstruction(Insn, 4, 1))
4795         align = 8;
4796       index = fieldFromInstruction(Insn, 6, 2);
4797       if (fieldFromInstruction(Insn, 5, 1))
4798         inc = 2;
4799       break;
4800     case 2:
4801       switch (fieldFromInstruction(Insn, 4, 2)) {
4802         case 0:
4803           align = 0; break;
4804         case 3:
4805           return MCDisassembler::Fail;
4806         default:
4807           align = 4 << fieldFromInstruction(Insn, 4, 2); break;
4808       }
4809 
4810       index = fieldFromInstruction(Insn, 7, 1);
4811       if (fieldFromInstruction(Insn, 6, 1))
4812         inc = 2;
4813       break;
4814   }
4815 
4816   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4817     return MCDisassembler::Fail;
4818   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4819     return MCDisassembler::Fail;
4820   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
4821     return MCDisassembler::Fail;
4822   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
4823     return MCDisassembler::Fail;
4824 
4825   if (Rm != 0xF) { // Writeback
4826     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4827       return MCDisassembler::Fail;
4828   }
4829   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4830     return MCDisassembler::Fail;
4831   Inst.addOperand(MCOperand::createImm(align));
4832   if (Rm != 0xF) {
4833     if (Rm != 0xD) {
4834       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4835         return MCDisassembler::Fail;
4836     } else
4837       Inst.addOperand(MCOperand::createReg(0));
4838   }
4839 
4840   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4841     return MCDisassembler::Fail;
4842   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4843     return MCDisassembler::Fail;
4844   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
4845     return MCDisassembler::Fail;
4846   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
4847     return MCDisassembler::Fail;
4848   Inst.addOperand(MCOperand::createImm(index));
4849 
4850   return S;
4851 }
4852 
4853 static DecodeStatus DecodeVST4LN(MCInst &Inst, unsigned Insn,
4854                          uint64_t Address, const void *Decoder) {
4855   DecodeStatus S = MCDisassembler::Success;
4856 
4857   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4858   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4859   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4860   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4861   unsigned size = fieldFromInstruction(Insn, 10, 2);
4862 
4863   unsigned align = 0;
4864   unsigned index = 0;
4865   unsigned inc = 1;
4866   switch (size) {
4867     default:
4868       return MCDisassembler::Fail;
4869     case 0:
4870       if (fieldFromInstruction(Insn, 4, 1))
4871         align = 4;
4872       index = fieldFromInstruction(Insn, 5, 3);
4873       break;
4874     case 1:
4875       if (fieldFromInstruction(Insn, 4, 1))
4876         align = 8;
4877       index = fieldFromInstruction(Insn, 6, 2);
4878       if (fieldFromInstruction(Insn, 5, 1))
4879         inc = 2;
4880       break;
4881     case 2:
4882       switch (fieldFromInstruction(Insn, 4, 2)) {
4883         case 0:
4884           align = 0; break;
4885         case 3:
4886           return MCDisassembler::Fail;
4887         default:
4888           align = 4 << fieldFromInstruction(Insn, 4, 2); break;
4889       }
4890 
4891       index = fieldFromInstruction(Insn, 7, 1);
4892       if (fieldFromInstruction(Insn, 6, 1))
4893         inc = 2;
4894       break;
4895   }
4896 
4897   if (Rm != 0xF) { // Writeback
4898     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4899     return MCDisassembler::Fail;
4900   }
4901   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4902     return MCDisassembler::Fail;
4903   Inst.addOperand(MCOperand::createImm(align));
4904   if (Rm != 0xF) {
4905     if (Rm != 0xD) {
4906       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4907     return MCDisassembler::Fail;
4908     } else
4909       Inst.addOperand(MCOperand::createReg(0));
4910   }
4911 
4912   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4913     return MCDisassembler::Fail;
4914   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4915     return MCDisassembler::Fail;
4916   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
4917     return MCDisassembler::Fail;
4918   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
4919     return MCDisassembler::Fail;
4920   Inst.addOperand(MCOperand::createImm(index));
4921 
4922   return S;
4923 }
4924 
4925 static DecodeStatus DecodeVMOVSRR(MCInst &Inst, unsigned Insn,
4926                                   uint64_t Address, const void *Decoder) {
4927   DecodeStatus S = MCDisassembler::Success;
4928   unsigned Rt  = fieldFromInstruction(Insn, 12, 4);
4929   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
4930   unsigned Rm  = fieldFromInstruction(Insn,  5, 1);
4931   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4932   Rm |= fieldFromInstruction(Insn, 0, 4) << 1;
4933 
4934   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
4935     S = MCDisassembler::SoftFail;
4936 
4937   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
4938     return MCDisassembler::Fail;
4939   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
4940     return MCDisassembler::Fail;
4941   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
4942     return MCDisassembler::Fail;
4943   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
4944     return MCDisassembler::Fail;
4945   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4946     return MCDisassembler::Fail;
4947 
4948   return S;
4949 }
4950 
4951 static DecodeStatus DecodeVMOVRRS(MCInst &Inst, unsigned Insn,
4952                                   uint64_t Address, const void *Decoder) {
4953   DecodeStatus S = MCDisassembler::Success;
4954   unsigned Rt  = fieldFromInstruction(Insn, 12, 4);
4955   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
4956   unsigned Rm  = fieldFromInstruction(Insn,  5, 1);
4957   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4958   Rm |= fieldFromInstruction(Insn, 0, 4) << 1;
4959 
4960   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
4961     S = MCDisassembler::SoftFail;
4962 
4963   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
4964     return MCDisassembler::Fail;
4965   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
4966     return MCDisassembler::Fail;
4967   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
4968     return MCDisassembler::Fail;
4969   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
4970     return MCDisassembler::Fail;
4971   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4972     return MCDisassembler::Fail;
4973 
4974   return S;
4975 }
4976 
4977 static DecodeStatus DecodeIT(MCInst &Inst, unsigned Insn,
4978                              uint64_t Address, const void *Decoder) {
4979   DecodeStatus S = MCDisassembler::Success;
4980   unsigned pred = fieldFromInstruction(Insn, 4, 4);
4981   unsigned mask = fieldFromInstruction(Insn, 0, 4);
4982 
4983   if (pred == 0xF) {
4984     pred = 0xE;
4985     S = MCDisassembler::SoftFail;
4986   }
4987 
4988   if (mask == 0x0)
4989     return MCDisassembler::Fail;
4990 
4991   Inst.addOperand(MCOperand::createImm(pred));
4992   Inst.addOperand(MCOperand::createImm(mask));
4993   return S;
4994 }
4995 
4996 static DecodeStatus
4997 DecodeT2LDRDPreInstruction(MCInst &Inst, unsigned Insn,
4998                            uint64_t Address, const void *Decoder) {
4999   DecodeStatus S = MCDisassembler::Success;
5000 
5001   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5002   unsigned Rt2 = fieldFromInstruction(Insn, 8, 4);
5003   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5004   unsigned addr = fieldFromInstruction(Insn, 0, 8);
5005   unsigned W = fieldFromInstruction(Insn, 21, 1);
5006   unsigned U = fieldFromInstruction(Insn, 23, 1);
5007   unsigned P = fieldFromInstruction(Insn, 24, 1);
5008   bool writeback = (W == 1) | (P == 0);
5009 
5010   addr |= (U << 8) | (Rn << 9);
5011 
5012   if (writeback && (Rn == Rt || Rn == Rt2))
5013     Check(S, MCDisassembler::SoftFail);
5014   if (Rt == Rt2)
5015     Check(S, MCDisassembler::SoftFail);
5016 
5017   // Rt
5018   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
5019     return MCDisassembler::Fail;
5020   // Rt2
5021   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
5022     return MCDisassembler::Fail;
5023   // Writeback operand
5024   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
5025     return MCDisassembler::Fail;
5026   // addr
5027   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
5028     return MCDisassembler::Fail;
5029 
5030   return S;
5031 }
5032 
5033 static DecodeStatus
5034 DecodeT2STRDPreInstruction(MCInst &Inst, unsigned Insn,
5035                            uint64_t Address, const void *Decoder) {
5036   DecodeStatus S = MCDisassembler::Success;
5037 
5038   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5039   unsigned Rt2 = fieldFromInstruction(Insn, 8, 4);
5040   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5041   unsigned addr = fieldFromInstruction(Insn, 0, 8);
5042   unsigned W = fieldFromInstruction(Insn, 21, 1);
5043   unsigned U = fieldFromInstruction(Insn, 23, 1);
5044   unsigned P = fieldFromInstruction(Insn, 24, 1);
5045   bool writeback = (W == 1) | (P == 0);
5046 
5047   addr |= (U << 8) | (Rn << 9);
5048 
5049   if (writeback && (Rn == Rt || Rn == Rt2))
5050     Check(S, MCDisassembler::SoftFail);
5051 
5052   // Writeback operand
5053   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
5054     return MCDisassembler::Fail;
5055   // Rt
5056   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
5057     return MCDisassembler::Fail;
5058   // Rt2
5059   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
5060     return MCDisassembler::Fail;
5061   // addr
5062   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
5063     return MCDisassembler::Fail;
5064 
5065   return S;
5066 }
5067 
5068 static DecodeStatus DecodeT2Adr(MCInst &Inst, uint32_t Insn,
5069                                 uint64_t Address, const void *Decoder) {
5070   unsigned sign1 = fieldFromInstruction(Insn, 21, 1);
5071   unsigned sign2 = fieldFromInstruction(Insn, 23, 1);
5072   if (sign1 != sign2) return MCDisassembler::Fail;
5073 
5074   unsigned Val = fieldFromInstruction(Insn, 0, 8);
5075   Val |= fieldFromInstruction(Insn, 12, 3) << 8;
5076   Val |= fieldFromInstruction(Insn, 26, 1) << 11;
5077   Val |= sign1 << 12;
5078   Inst.addOperand(MCOperand::createImm(SignExtend32<13>(Val)));
5079 
5080   return MCDisassembler::Success;
5081 }
5082 
5083 static DecodeStatus DecodeT2ShifterImmOperand(MCInst &Inst, uint32_t Val,
5084                                               uint64_t Address,
5085                                               const void *Decoder) {
5086   DecodeStatus S = MCDisassembler::Success;
5087 
5088   // Shift of "asr #32" is not allowed in Thumb2 mode.
5089   if (Val == 0x20) S = MCDisassembler::Fail;
5090   Inst.addOperand(MCOperand::createImm(Val));
5091   return S;
5092 }
5093 
5094 static DecodeStatus DecodeSwap(MCInst &Inst, unsigned Insn,
5095                                uint64_t Address, const void *Decoder) {
5096   unsigned Rt   = fieldFromInstruction(Insn, 12, 4);
5097   unsigned Rt2  = fieldFromInstruction(Insn, 0,  4);
5098   unsigned Rn   = fieldFromInstruction(Insn, 16, 4);
5099   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5100 
5101   if (pred == 0xF)
5102     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
5103 
5104   DecodeStatus S = MCDisassembler::Success;
5105 
5106   if (Rt == Rn || Rn == Rt2)
5107     S = MCDisassembler::SoftFail;
5108 
5109   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5110     return MCDisassembler::Fail;
5111   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5112     return MCDisassembler::Fail;
5113   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
5114     return MCDisassembler::Fail;
5115   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5116     return MCDisassembler::Fail;
5117 
5118   return S;
5119 }
5120 
5121 static DecodeStatus DecodeVCVTD(MCInst &Inst, unsigned Insn,
5122                                 uint64_t Address, const void *Decoder) {
5123   const FeatureBitset &featureBits =
5124       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5125   bool hasFullFP16 = featureBits[ARM::FeatureFullFP16];
5126 
5127   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5128   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5129   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5130   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5131   unsigned imm = fieldFromInstruction(Insn, 16, 6);
5132   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
5133   unsigned op = fieldFromInstruction(Insn, 5, 1);
5134 
5135   DecodeStatus S = MCDisassembler::Success;
5136 
5137   // If the top 3 bits of imm are clear, this is a VMOV (immediate)
5138   if (!(imm & 0x38)) {
5139     if (cmode == 0xF) {
5140       if (op == 1) return MCDisassembler::Fail;
5141       Inst.setOpcode(ARM::VMOVv2f32);
5142     }
5143     if (hasFullFP16) {
5144       if (cmode == 0xE) {
5145         if (op == 1) {
5146           Inst.setOpcode(ARM::VMOVv1i64);
5147         } else {
5148           Inst.setOpcode(ARM::VMOVv8i8);
5149         }
5150       }
5151       if (cmode == 0xD) {
5152         if (op == 1) {
5153           Inst.setOpcode(ARM::VMVNv2i32);
5154         } else {
5155           Inst.setOpcode(ARM::VMOVv2i32);
5156         }
5157       }
5158       if (cmode == 0xC) {
5159         if (op == 1) {
5160           Inst.setOpcode(ARM::VMVNv2i32);
5161         } else {
5162           Inst.setOpcode(ARM::VMOVv2i32);
5163         }
5164       }
5165     }
5166     return DecodeNEONModImmInstruction(Inst, Insn, Address, Decoder);
5167   }
5168 
5169   if (!(imm & 0x20)) return MCDisassembler::Fail;
5170 
5171   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
5172     return MCDisassembler::Fail;
5173   if (!Check(S, DecodeDPRRegisterClass(Inst, Vm, Address, Decoder)))
5174     return MCDisassembler::Fail;
5175   Inst.addOperand(MCOperand::createImm(64 - imm));
5176 
5177   return S;
5178 }
5179 
5180 static DecodeStatus DecodeVCVTQ(MCInst &Inst, unsigned Insn,
5181                                 uint64_t Address, const void *Decoder) {
5182   const FeatureBitset &featureBits =
5183       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5184   bool hasFullFP16 = featureBits[ARM::FeatureFullFP16];
5185 
5186   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5187   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5188   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5189   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5190   unsigned imm = fieldFromInstruction(Insn, 16, 6);
5191   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
5192   unsigned op = fieldFromInstruction(Insn, 5, 1);
5193 
5194   DecodeStatus S = MCDisassembler::Success;
5195 
5196   // If the top 3 bits of imm are clear, this is a VMOV (immediate)
5197   if (!(imm & 0x38)) {
5198     if (cmode == 0xF) {
5199       if (op == 1) return MCDisassembler::Fail;
5200       Inst.setOpcode(ARM::VMOVv4f32);
5201     }
5202     if (hasFullFP16) {
5203       if (cmode == 0xE) {
5204         if (op == 1) {
5205           Inst.setOpcode(ARM::VMOVv2i64);
5206         } else {
5207           Inst.setOpcode(ARM::VMOVv16i8);
5208         }
5209       }
5210       if (cmode == 0xD) {
5211         if (op == 1) {
5212           Inst.setOpcode(ARM::VMVNv4i32);
5213         } else {
5214           Inst.setOpcode(ARM::VMOVv4i32);
5215         }
5216       }
5217       if (cmode == 0xC) {
5218         if (op == 1) {
5219           Inst.setOpcode(ARM::VMVNv4i32);
5220         } else {
5221           Inst.setOpcode(ARM::VMOVv4i32);
5222         }
5223       }
5224     }
5225     return DecodeNEONModImmInstruction(Inst, Insn, Address, Decoder);
5226   }
5227 
5228   if (!(imm & 0x20)) return MCDisassembler::Fail;
5229 
5230   if (!Check(S, DecodeQPRRegisterClass(Inst, Vd, Address, Decoder)))
5231     return MCDisassembler::Fail;
5232   if (!Check(S, DecodeQPRRegisterClass(Inst, Vm, Address, Decoder)))
5233     return MCDisassembler::Fail;
5234   Inst.addOperand(MCOperand::createImm(64 - imm));
5235 
5236   return S;
5237 }
5238 
5239 static DecodeStatus DecodeLDR(MCInst &Inst, unsigned Val,
5240                                 uint64_t Address, const void *Decoder) {
5241   DecodeStatus S = MCDisassembler::Success;
5242 
5243   unsigned Rn = fieldFromInstruction(Val, 16, 4);
5244   unsigned Rt = fieldFromInstruction(Val, 12, 4);
5245   unsigned Rm = fieldFromInstruction(Val, 0, 4);
5246   Rm |= (fieldFromInstruction(Val, 23, 1) << 4);
5247   unsigned Cond = fieldFromInstruction(Val, 28, 4);
5248 
5249   if (fieldFromInstruction(Val, 8, 4) != 0 || Rn == Rt)
5250     S = MCDisassembler::SoftFail;
5251 
5252   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5253     return MCDisassembler::Fail;
5254   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
5255     return MCDisassembler::Fail;
5256   if (!Check(S, DecodeAddrMode7Operand(Inst, Rn, Address, Decoder)))
5257     return MCDisassembler::Fail;
5258   if (!Check(S, DecodePostIdxReg(Inst, Rm, Address, Decoder)))
5259     return MCDisassembler::Fail;
5260   if (!Check(S, DecodePredicateOperand(Inst, Cond, Address, Decoder)))
5261     return MCDisassembler::Fail;
5262 
5263   return S;
5264 }
5265 
5266 static DecodeStatus DecoderForMRRC2AndMCRR2(MCInst &Inst, unsigned Val,
5267                                             uint64_t Address, const void *Decoder) {
5268   DecodeStatus S = MCDisassembler::Success;
5269 
5270   unsigned CRm = fieldFromInstruction(Val, 0, 4);
5271   unsigned opc1 = fieldFromInstruction(Val, 4, 4);
5272   unsigned cop = fieldFromInstruction(Val, 8, 4);
5273   unsigned Rt = fieldFromInstruction(Val, 12, 4);
5274   unsigned Rt2 = fieldFromInstruction(Val, 16, 4);
5275 
5276   if ((cop & ~0x1) == 0xa)
5277     return MCDisassembler::Fail;
5278 
5279   if (Rt == Rt2)
5280     S = MCDisassembler::SoftFail;
5281 
5282   // We have to check if the instruction is MRRC2
5283   // or MCRR2 when constructing the operands for
5284   // Inst. Reason is because MRRC2 stores to two
5285   // registers so it's tablegen desc has has two
5286   // outputs whereas MCRR doesn't store to any
5287   // registers so all of it's operands are listed
5288   // as inputs, therefore the operand order for
5289   // MRRC2 needs to be [Rt, Rt2, cop, opc1, CRm]
5290   // and MCRR2 operand order is [cop, opc1, Rt, Rt2, CRm]
5291 
5292   if (Inst.getOpcode() == ARM::MRRC2) {
5293     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5294       return MCDisassembler::Fail;
5295     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5296       return MCDisassembler::Fail;
5297   }
5298   Inst.addOperand(MCOperand::createImm(cop));
5299   Inst.addOperand(MCOperand::createImm(opc1));
5300   if (Inst.getOpcode() == ARM::MCRR2) {
5301     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5302       return MCDisassembler::Fail;
5303     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5304       return MCDisassembler::Fail;
5305   }
5306   Inst.addOperand(MCOperand::createImm(CRm));
5307 
5308   return S;
5309 }
5310