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/TargetRegistry.h"
24 #include "llvm/Support/raw_ostream.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   struct DecodeTable {
466     const uint8_t *P;
467     bool DecodePred;
468   };
469 
470   const DecodeTable Tables[] = {
471       {DecoderTableVFP32, false},      {DecoderTableVFPV832, false},
472       {DecoderTableNEONData32, true},  {DecoderTableNEONLoadStore32, true},
473       {DecoderTableNEONDup32, true},   {DecoderTablev8NEON32, false},
474       {DecoderTablev8Crypto32, false},
475   };
476 
477   for (auto Table : Tables) {
478     Result = decodeInstruction(Table.P, MI, Insn, Address, this, STI);
479     if (Result != MCDisassembler::Fail) {
480       Size = 4;
481       // Add a fake predicate operand, because we share these instruction
482       // definitions with Thumb2 where these instructions are predicable.
483       if (Table.DecodePred && !DecodePredicateOperand(MI, 0xE, Address, this))
484         return MCDisassembler::Fail;
485       return Result;
486     }
487   }
488 
489   Result =
490       decodeInstruction(DecoderTableCoProc32, MI, Insn, Address, this, STI);
491   if (Result != MCDisassembler::Fail) {
492     Size = 4;
493     return checkDecodedInstruction(MI, Size, Address, OS, CS, Insn, Result);
494   }
495 
496   Size = 4;
497   return MCDisassembler::Fail;
498 }
499 
500 namespace llvm {
501 
502 extern const MCInstrDesc ARMInsts[];
503 
504 } // end namespace llvm
505 
506 /// tryAddingSymbolicOperand - trys to add a symbolic operand in place of the
507 /// immediate Value in the MCInst.  The immediate Value has had any PC
508 /// adjustment made by the caller.  If the instruction is a branch instruction
509 /// then isBranch is true, else false.  If the getOpInfo() function was set as
510 /// part of the setupForSymbolicDisassembly() call then that function is called
511 /// to get any symbolic information at the Address for this instruction.  If
512 /// that returns non-zero then the symbolic information it returns is used to
513 /// create an MCExpr and that is added as an operand to the MCInst.  If
514 /// getOpInfo() returns zero and isBranch is true then a symbol look up for
515 /// Value is done and if a symbol is found an MCExpr is created with that, else
516 /// an MCExpr with Value is created.  This function returns true if it adds an
517 /// operand to the MCInst and false otherwise.
518 static bool tryAddingSymbolicOperand(uint64_t Address, int32_t Value,
519                                      bool isBranch, uint64_t InstSize,
520                                      MCInst &MI, const void *Decoder) {
521   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
522   // FIXME: Does it make sense for value to be negative?
523   return Dis->tryAddingSymbolicOperand(MI, (uint32_t)Value, Address, isBranch,
524                                        /* Offset */ 0, InstSize);
525 }
526 
527 /// tryAddingPcLoadReferenceComment - trys to add a comment as to what is being
528 /// referenced by a load instruction with the base register that is the Pc.
529 /// These can often be values in a literal pool near the Address of the
530 /// instruction.  The Address of the instruction and its immediate Value are
531 /// used as a possible literal pool entry.  The SymbolLookUp call back will
532 /// return the name of a symbol referenced by the literal pool's entry if
533 /// the referenced address is that of a symbol.  Or it will return a pointer to
534 /// a literal 'C' string if the referenced address of the literal pool's entry
535 /// is an address into a section with 'C' string literals.
536 static void tryAddingPcLoadReferenceComment(uint64_t Address, int Value,
537                                             const void *Decoder) {
538   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
539   Dis->tryAddingPcLoadReferenceComment(Value, Address);
540 }
541 
542 // Thumb1 instructions don't have explicit S bits.  Rather, they
543 // implicitly set CPSR.  Since it's not represented in the encoding, the
544 // auto-generated decoder won't inject the CPSR operand.  We need to fix
545 // that as a post-pass.
546 static void AddThumb1SBit(MCInst &MI, bool InITBlock) {
547   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
548   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
549   MCInst::iterator I = MI.begin();
550   for (unsigned i = 0; i < NumOps; ++i, ++I) {
551     if (I == MI.end()) break;
552     if (OpInfo[i].isOptionalDef() && OpInfo[i].RegClass == ARM::CCRRegClassID) {
553       if (i > 0 && OpInfo[i-1].isPredicate()) continue;
554       MI.insert(I, MCOperand::createReg(InITBlock ? 0 : ARM::CPSR));
555       return;
556     }
557   }
558 
559   MI.insert(I, MCOperand::createReg(InITBlock ? 0 : ARM::CPSR));
560 }
561 
562 // Most Thumb instructions don't have explicit predicates in the
563 // encoding, but rather get their predicates from IT context.  We need
564 // to fix up the predicate operands using this context information as a
565 // post-pass.
566 MCDisassembler::DecodeStatus
567 ThumbDisassembler::AddThumbPredicate(MCInst &MI) const {
568   MCDisassembler::DecodeStatus S = Success;
569 
570   const FeatureBitset &FeatureBits = getSubtargetInfo().getFeatureBits();
571 
572   // A few instructions actually have predicates encoded in them.  Don't
573   // try to overwrite it if we're seeing one of those.
574   switch (MI.getOpcode()) {
575     case ARM::tBcc:
576     case ARM::t2Bcc:
577     case ARM::tCBZ:
578     case ARM::tCBNZ:
579     case ARM::tCPS:
580     case ARM::t2CPS3p:
581     case ARM::t2CPS2p:
582     case ARM::t2CPS1p:
583     case ARM::tMOVSr:
584     case ARM::tSETEND:
585       // Some instructions (mostly conditional branches) are not
586       // allowed in IT blocks.
587       if (ITBlock.instrInITBlock())
588         S = SoftFail;
589       else
590         return Success;
591       break;
592     case ARM::t2HINT:
593       if (MI.getOperand(0).getImm() == 0x10 && (FeatureBits[ARM::FeatureRAS]) != 0)
594         S = SoftFail;
595       break;
596     case ARM::tB:
597     case ARM::t2B:
598     case ARM::t2TBB:
599     case ARM::t2TBH:
600       // Some instructions (mostly unconditional branches) can
601       // only appears at the end of, or outside of, an IT.
602       if (ITBlock.instrInITBlock() && !ITBlock.instrLastInITBlock())
603         S = SoftFail;
604       break;
605     default:
606       break;
607   }
608 
609   // If we're in an IT block, base the predicate on that.  Otherwise,
610   // assume a predicate of AL.
611   unsigned CC;
612   CC = ITBlock.getITCC();
613   if (CC == 0xF)
614     CC = ARMCC::AL;
615   if (ITBlock.instrInITBlock())
616     ITBlock.advanceITState();
617 
618   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
619   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
620   MCInst::iterator I = MI.begin();
621   for (unsigned i = 0; i < NumOps; ++i, ++I) {
622     if (I == MI.end()) break;
623     if (OpInfo[i].isPredicate()) {
624       I = MI.insert(I, MCOperand::createImm(CC));
625       ++I;
626       if (CC == ARMCC::AL)
627         MI.insert(I, MCOperand::createReg(0));
628       else
629         MI.insert(I, MCOperand::createReg(ARM::CPSR));
630       return S;
631     }
632   }
633 
634   I = MI.insert(I, MCOperand::createImm(CC));
635   ++I;
636   if (CC == ARMCC::AL)
637     MI.insert(I, MCOperand::createReg(0));
638   else
639     MI.insert(I, MCOperand::createReg(ARM::CPSR));
640 
641   return S;
642 }
643 
644 // Thumb VFP instructions are a special case.  Because we share their
645 // encodings between ARM and Thumb modes, and they are predicable in ARM
646 // mode, the auto-generated decoder will give them an (incorrect)
647 // predicate operand.  We need to rewrite these operands based on the IT
648 // context as a post-pass.
649 void ThumbDisassembler::UpdateThumbVFPPredicate(MCInst &MI) const {
650   unsigned CC;
651   CC = ITBlock.getITCC();
652   if (ITBlock.instrInITBlock())
653     ITBlock.advanceITState();
654 
655   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
656   MCInst::iterator I = MI.begin();
657   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
658   for (unsigned i = 0; i < NumOps; ++i, ++I) {
659     if (OpInfo[i].isPredicate() ) {
660       I->setImm(CC);
661       ++I;
662       if (CC == ARMCC::AL)
663         I->setReg(0);
664       else
665         I->setReg(ARM::CPSR);
666       return;
667     }
668   }
669 }
670 
671 DecodeStatus ThumbDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
672                                                ArrayRef<uint8_t> Bytes,
673                                                uint64_t Address,
674                                                raw_ostream &OS,
675                                                raw_ostream &CS) const {
676   CommentStream = &CS;
677 
678   assert(STI.getFeatureBits()[ARM::ModeThumb] &&
679          "Asked to disassemble in Thumb mode but Subtarget is in ARM mode!");
680 
681   // We want to read exactly 2 bytes of data.
682   if (Bytes.size() < 2) {
683     Size = 0;
684     return MCDisassembler::Fail;
685   }
686 
687   uint16_t Insn16 = (Bytes[1] << 8) | Bytes[0];
688   DecodeStatus Result =
689       decodeInstruction(DecoderTableThumb16, MI, Insn16, Address, this, STI);
690   if (Result != MCDisassembler::Fail) {
691     Size = 2;
692     Check(Result, AddThumbPredicate(MI));
693     return Result;
694   }
695 
696   Result = decodeInstruction(DecoderTableThumbSBit16, MI, Insn16, Address, this,
697                              STI);
698   if (Result) {
699     Size = 2;
700     bool InITBlock = ITBlock.instrInITBlock();
701     Check(Result, AddThumbPredicate(MI));
702     AddThumb1SBit(MI, InITBlock);
703     return Result;
704   }
705 
706   Result =
707       decodeInstruction(DecoderTableThumb216, MI, Insn16, Address, this, STI);
708   if (Result != MCDisassembler::Fail) {
709     Size = 2;
710 
711     // Nested IT blocks are UNPREDICTABLE.  Must be checked before we add
712     // the Thumb predicate.
713     if (MI.getOpcode() == ARM::t2IT && ITBlock.instrInITBlock())
714       Result = MCDisassembler::SoftFail;
715 
716     Check(Result, AddThumbPredicate(MI));
717 
718     // If we find an IT instruction, we need to parse its condition
719     // code and mask operands so that we can apply them correctly
720     // to the subsequent instructions.
721     if (MI.getOpcode() == ARM::t2IT) {
722 
723       unsigned Firstcond = MI.getOperand(0).getImm();
724       unsigned Mask = MI.getOperand(1).getImm();
725       ITBlock.setITState(Firstcond, Mask);
726     }
727 
728     return Result;
729   }
730 
731   // We want to read exactly 4 bytes of data.
732   if (Bytes.size() < 4) {
733     Size = 0;
734     return MCDisassembler::Fail;
735   }
736 
737   uint32_t Insn32 =
738       (Bytes[3] << 8) | (Bytes[2] << 0) | (Bytes[1] << 24) | (Bytes[0] << 16);
739   Result =
740       decodeInstruction(DecoderTableThumb32, MI, Insn32, Address, this, STI);
741   if (Result != MCDisassembler::Fail) {
742     Size = 4;
743     bool InITBlock = ITBlock.instrInITBlock();
744     Check(Result, AddThumbPredicate(MI));
745     AddThumb1SBit(MI, InITBlock);
746     return Result;
747   }
748 
749   Result =
750       decodeInstruction(DecoderTableThumb232, MI, Insn32, Address, this, STI);
751   if (Result != MCDisassembler::Fail) {
752     Size = 4;
753     Check(Result, AddThumbPredicate(MI));
754     return Result;
755   }
756 
757   if (fieldFromInstruction(Insn32, 28, 4) == 0xE) {
758     Result =
759         decodeInstruction(DecoderTableVFP32, MI, Insn32, Address, this, STI);
760     if (Result != MCDisassembler::Fail) {
761       Size = 4;
762       UpdateThumbVFPPredicate(MI);
763       return Result;
764     }
765   }
766 
767   Result =
768       decodeInstruction(DecoderTableVFPV832, MI, Insn32, Address, this, STI);
769   if (Result != MCDisassembler::Fail) {
770     Size = 4;
771     return Result;
772   }
773 
774   if (fieldFromInstruction(Insn32, 28, 4) == 0xE) {
775     Result = decodeInstruction(DecoderTableNEONDup32, MI, Insn32, Address, this,
776                                STI);
777     if (Result != MCDisassembler::Fail) {
778       Size = 4;
779       Check(Result, AddThumbPredicate(MI));
780       return Result;
781     }
782   }
783 
784   if (fieldFromInstruction(Insn32, 24, 8) == 0xF9) {
785     uint32_t NEONLdStInsn = Insn32;
786     NEONLdStInsn &= 0xF0FFFFFF;
787     NEONLdStInsn |= 0x04000000;
788     Result = decodeInstruction(DecoderTableNEONLoadStore32, MI, NEONLdStInsn,
789                                Address, this, STI);
790     if (Result != MCDisassembler::Fail) {
791       Size = 4;
792       Check(Result, AddThumbPredicate(MI));
793       return Result;
794     }
795   }
796 
797   if (fieldFromInstruction(Insn32, 24, 4) == 0xF) {
798     uint32_t NEONDataInsn = Insn32;
799     NEONDataInsn &= 0xF0FFFFFF; // Clear bits 27-24
800     NEONDataInsn |= (NEONDataInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
801     NEONDataInsn |= 0x12000000; // Set bits 28 and 25
802     Result = decodeInstruction(DecoderTableNEONData32, MI, NEONDataInsn,
803                                Address, this, STI);
804     if (Result != MCDisassembler::Fail) {
805       Size = 4;
806       Check(Result, AddThumbPredicate(MI));
807       return Result;
808     }
809 
810     uint32_t NEONCryptoInsn = Insn32;
811     NEONCryptoInsn &= 0xF0FFFFFF; // Clear bits 27-24
812     NEONCryptoInsn |= (NEONCryptoInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
813     NEONCryptoInsn |= 0x12000000; // Set bits 28 and 25
814     Result = decodeInstruction(DecoderTablev8Crypto32, MI, NEONCryptoInsn,
815                                Address, this, STI);
816     if (Result != MCDisassembler::Fail) {
817       Size = 4;
818       return Result;
819     }
820 
821     uint32_t NEONv8Insn = Insn32;
822     NEONv8Insn &= 0xF3FFFFFF; // Clear bits 27-26
823     Result = decodeInstruction(DecoderTablev8NEON32, MI, NEONv8Insn, Address,
824                                this, STI);
825     if (Result != MCDisassembler::Fail) {
826       Size = 4;
827       return Result;
828     }
829   }
830 
831   Result =
832       decodeInstruction(DecoderTableThumb2CoProc32, MI, Insn32, Address, this, STI);
833   if (Result != MCDisassembler::Fail) {
834     Size = 4;
835     Check(Result, AddThumbPredicate(MI));
836     return Result;
837   }
838 
839   Size = 0;
840   return MCDisassembler::Fail;
841 }
842 
843 extern "C" void LLVMInitializeARMDisassembler() {
844   TargetRegistry::RegisterMCDisassembler(getTheARMLETarget(),
845                                          createARMDisassembler);
846   TargetRegistry::RegisterMCDisassembler(getTheARMBETarget(),
847                                          createARMDisassembler);
848   TargetRegistry::RegisterMCDisassembler(getTheThumbLETarget(),
849                                          createThumbDisassembler);
850   TargetRegistry::RegisterMCDisassembler(getTheThumbBETarget(),
851                                          createThumbDisassembler);
852 }
853 
854 static const uint16_t GPRDecoderTable[] = {
855   ARM::R0, ARM::R1, ARM::R2, ARM::R3,
856   ARM::R4, ARM::R5, ARM::R6, ARM::R7,
857   ARM::R8, ARM::R9, ARM::R10, ARM::R11,
858   ARM::R12, ARM::SP, ARM::LR, ARM::PC
859 };
860 
861 static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, unsigned RegNo,
862                                    uint64_t Address, const void *Decoder) {
863   if (RegNo > 15)
864     return MCDisassembler::Fail;
865 
866   unsigned Register = GPRDecoderTable[RegNo];
867   Inst.addOperand(MCOperand::createReg(Register));
868   return MCDisassembler::Success;
869 }
870 
871 static DecodeStatus
872 DecodeGPRnopcRegisterClass(MCInst &Inst, unsigned RegNo,
873                            uint64_t Address, const void *Decoder) {
874   DecodeStatus S = MCDisassembler::Success;
875 
876   if (RegNo == 15)
877     S = MCDisassembler::SoftFail;
878 
879   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
880 
881   return S;
882 }
883 
884 static DecodeStatus
885 DecodeGPRwithAPSRRegisterClass(MCInst &Inst, unsigned RegNo,
886                                uint64_t Address, const void *Decoder) {
887   DecodeStatus S = MCDisassembler::Success;
888 
889   if (RegNo == 15)
890   {
891     Inst.addOperand(MCOperand::createReg(ARM::APSR_NZCV));
892     return MCDisassembler::Success;
893   }
894 
895   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
896   return S;
897 }
898 
899 static DecodeStatus DecodetGPRRegisterClass(MCInst &Inst, unsigned RegNo,
900                                    uint64_t Address, const void *Decoder) {
901   if (RegNo > 7)
902     return MCDisassembler::Fail;
903   return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
904 }
905 
906 static const uint16_t GPRPairDecoderTable[] = {
907   ARM::R0_R1, ARM::R2_R3,   ARM::R4_R5,  ARM::R6_R7,
908   ARM::R8_R9, ARM::R10_R11, ARM::R12_SP
909 };
910 
911 static DecodeStatus DecodeGPRPairRegisterClass(MCInst &Inst, unsigned RegNo,
912                                    uint64_t Address, const void *Decoder) {
913   DecodeStatus S = MCDisassembler::Success;
914 
915   if (RegNo > 13)
916     return MCDisassembler::Fail;
917 
918   if ((RegNo & 1) || RegNo == 0xe)
919      S = MCDisassembler::SoftFail;
920 
921   unsigned RegisterPair = GPRPairDecoderTable[RegNo/2];
922   Inst.addOperand(MCOperand::createReg(RegisterPair));
923   return S;
924 }
925 
926 static DecodeStatus DecodetcGPRRegisterClass(MCInst &Inst, unsigned RegNo,
927                                    uint64_t Address, const void *Decoder) {
928   unsigned Register = 0;
929   switch (RegNo) {
930     case 0:
931       Register = ARM::R0;
932       break;
933     case 1:
934       Register = ARM::R1;
935       break;
936     case 2:
937       Register = ARM::R2;
938       break;
939     case 3:
940       Register = ARM::R3;
941       break;
942     case 9:
943       Register = ARM::R9;
944       break;
945     case 12:
946       Register = ARM::R12;
947       break;
948     default:
949       return MCDisassembler::Fail;
950     }
951 
952   Inst.addOperand(MCOperand::createReg(Register));
953   return MCDisassembler::Success;
954 }
955 
956 static DecodeStatus DecoderGPRRegisterClass(MCInst &Inst, unsigned RegNo,
957                                    uint64_t Address, const void *Decoder) {
958   DecodeStatus S = MCDisassembler::Success;
959 
960   const FeatureBitset &featureBits =
961     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
962 
963   if ((RegNo == 13 && !featureBits[ARM::HasV8Ops]) || RegNo == 15)
964     S = MCDisassembler::SoftFail;
965 
966   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
967   return S;
968 }
969 
970 static const uint16_t SPRDecoderTable[] = {
971      ARM::S0,  ARM::S1,  ARM::S2,  ARM::S3,
972      ARM::S4,  ARM::S5,  ARM::S6,  ARM::S7,
973      ARM::S8,  ARM::S9, ARM::S10, ARM::S11,
974     ARM::S12, ARM::S13, ARM::S14, ARM::S15,
975     ARM::S16, ARM::S17, ARM::S18, ARM::S19,
976     ARM::S20, ARM::S21, ARM::S22, ARM::S23,
977     ARM::S24, ARM::S25, ARM::S26, ARM::S27,
978     ARM::S28, ARM::S29, ARM::S30, ARM::S31
979 };
980 
981 static DecodeStatus DecodeSPRRegisterClass(MCInst &Inst, unsigned RegNo,
982                                    uint64_t Address, const void *Decoder) {
983   if (RegNo > 31)
984     return MCDisassembler::Fail;
985 
986   unsigned Register = SPRDecoderTable[RegNo];
987   Inst.addOperand(MCOperand::createReg(Register));
988   return MCDisassembler::Success;
989 }
990 
991 static const uint16_t DPRDecoderTable[] = {
992      ARM::D0,  ARM::D1,  ARM::D2,  ARM::D3,
993      ARM::D4,  ARM::D5,  ARM::D6,  ARM::D7,
994      ARM::D8,  ARM::D9, ARM::D10, ARM::D11,
995     ARM::D12, ARM::D13, ARM::D14, ARM::D15,
996     ARM::D16, ARM::D17, ARM::D18, ARM::D19,
997     ARM::D20, ARM::D21, ARM::D22, ARM::D23,
998     ARM::D24, ARM::D25, ARM::D26, ARM::D27,
999     ARM::D28, ARM::D29, ARM::D30, ARM::D31
1000 };
1001 
1002 static DecodeStatus DecodeDPRRegisterClass(MCInst &Inst, unsigned RegNo,
1003                                    uint64_t Address, const void *Decoder) {
1004   const FeatureBitset &featureBits =
1005     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1006 
1007   bool hasD16 = featureBits[ARM::FeatureD16];
1008 
1009   if (RegNo > 31 || (hasD16 && RegNo > 15))
1010     return MCDisassembler::Fail;
1011 
1012   unsigned Register = DPRDecoderTable[RegNo];
1013   Inst.addOperand(MCOperand::createReg(Register));
1014   return MCDisassembler::Success;
1015 }
1016 
1017 static DecodeStatus DecodeDPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
1018                                    uint64_t Address, const void *Decoder) {
1019   if (RegNo > 7)
1020     return MCDisassembler::Fail;
1021   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
1022 }
1023 
1024 static DecodeStatus
1025 DecodeDPR_VFP2RegisterClass(MCInst &Inst, unsigned RegNo,
1026                             uint64_t Address, const void *Decoder) {
1027   if (RegNo > 15)
1028     return MCDisassembler::Fail;
1029   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
1030 }
1031 
1032 static const uint16_t QPRDecoderTable[] = {
1033      ARM::Q0,  ARM::Q1,  ARM::Q2,  ARM::Q3,
1034      ARM::Q4,  ARM::Q5,  ARM::Q6,  ARM::Q7,
1035      ARM::Q8,  ARM::Q9, ARM::Q10, ARM::Q11,
1036     ARM::Q12, ARM::Q13, ARM::Q14, ARM::Q15
1037 };
1038 
1039 static DecodeStatus DecodeQPRRegisterClass(MCInst &Inst, unsigned RegNo,
1040                                    uint64_t Address, const void *Decoder) {
1041   if (RegNo > 31 || (RegNo & 1) != 0)
1042     return MCDisassembler::Fail;
1043   RegNo >>= 1;
1044 
1045   unsigned Register = QPRDecoderTable[RegNo];
1046   Inst.addOperand(MCOperand::createReg(Register));
1047   return MCDisassembler::Success;
1048 }
1049 
1050 static const uint16_t DPairDecoderTable[] = {
1051   ARM::Q0,  ARM::D1_D2,   ARM::Q1,  ARM::D3_D4,   ARM::Q2,  ARM::D5_D6,
1052   ARM::Q3,  ARM::D7_D8,   ARM::Q4,  ARM::D9_D10,  ARM::Q5,  ARM::D11_D12,
1053   ARM::Q6,  ARM::D13_D14, ARM::Q7,  ARM::D15_D16, ARM::Q8,  ARM::D17_D18,
1054   ARM::Q9,  ARM::D19_D20, ARM::Q10, ARM::D21_D22, ARM::Q11, ARM::D23_D24,
1055   ARM::Q12, ARM::D25_D26, ARM::Q13, ARM::D27_D28, ARM::Q14, ARM::D29_D30,
1056   ARM::Q15
1057 };
1058 
1059 static DecodeStatus DecodeDPairRegisterClass(MCInst &Inst, unsigned RegNo,
1060                                    uint64_t Address, const void *Decoder) {
1061   if (RegNo > 30)
1062     return MCDisassembler::Fail;
1063 
1064   unsigned Register = DPairDecoderTable[RegNo];
1065   Inst.addOperand(MCOperand::createReg(Register));
1066   return MCDisassembler::Success;
1067 }
1068 
1069 static const uint16_t DPairSpacedDecoderTable[] = {
1070   ARM::D0_D2,   ARM::D1_D3,   ARM::D2_D4,   ARM::D3_D5,
1071   ARM::D4_D6,   ARM::D5_D7,   ARM::D6_D8,   ARM::D7_D9,
1072   ARM::D8_D10,  ARM::D9_D11,  ARM::D10_D12, ARM::D11_D13,
1073   ARM::D12_D14, ARM::D13_D15, ARM::D14_D16, ARM::D15_D17,
1074   ARM::D16_D18, ARM::D17_D19, ARM::D18_D20, ARM::D19_D21,
1075   ARM::D20_D22, ARM::D21_D23, ARM::D22_D24, ARM::D23_D25,
1076   ARM::D24_D26, ARM::D25_D27, ARM::D26_D28, ARM::D27_D29,
1077   ARM::D28_D30, ARM::D29_D31
1078 };
1079 
1080 static DecodeStatus DecodeDPairSpacedRegisterClass(MCInst &Inst,
1081                                                    unsigned RegNo,
1082                                                    uint64_t Address,
1083                                                    const void *Decoder) {
1084   if (RegNo > 29)
1085     return MCDisassembler::Fail;
1086 
1087   unsigned Register = DPairSpacedDecoderTable[RegNo];
1088   Inst.addOperand(MCOperand::createReg(Register));
1089   return MCDisassembler::Success;
1090 }
1091 
1092 static DecodeStatus DecodePredicateOperand(MCInst &Inst, unsigned Val,
1093                                uint64_t Address, const void *Decoder) {
1094   if (Val == 0xF) return MCDisassembler::Fail;
1095   // AL predicate is not allowed on Thumb1 branches.
1096   if (Inst.getOpcode() == ARM::tBcc && Val == 0xE)
1097     return MCDisassembler::Fail;
1098   Inst.addOperand(MCOperand::createImm(Val));
1099   if (Val == ARMCC::AL) {
1100     Inst.addOperand(MCOperand::createReg(0));
1101   } else
1102     Inst.addOperand(MCOperand::createReg(ARM::CPSR));
1103   return MCDisassembler::Success;
1104 }
1105 
1106 static DecodeStatus DecodeCCOutOperand(MCInst &Inst, unsigned Val,
1107                                uint64_t Address, const void *Decoder) {
1108   if (Val)
1109     Inst.addOperand(MCOperand::createReg(ARM::CPSR));
1110   else
1111     Inst.addOperand(MCOperand::createReg(0));
1112   return MCDisassembler::Success;
1113 }
1114 
1115 static DecodeStatus DecodeSORegImmOperand(MCInst &Inst, unsigned Val,
1116                                uint64_t Address, const void *Decoder) {
1117   DecodeStatus S = MCDisassembler::Success;
1118 
1119   unsigned Rm = fieldFromInstruction(Val, 0, 4);
1120   unsigned type = fieldFromInstruction(Val, 5, 2);
1121   unsigned imm = fieldFromInstruction(Val, 7, 5);
1122 
1123   // Register-immediate
1124   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
1125     return MCDisassembler::Fail;
1126 
1127   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1128   switch (type) {
1129     case 0:
1130       Shift = ARM_AM::lsl;
1131       break;
1132     case 1:
1133       Shift = ARM_AM::lsr;
1134       break;
1135     case 2:
1136       Shift = ARM_AM::asr;
1137       break;
1138     case 3:
1139       Shift = ARM_AM::ror;
1140       break;
1141   }
1142 
1143   if (Shift == ARM_AM::ror && imm == 0)
1144     Shift = ARM_AM::rrx;
1145 
1146   unsigned Op = Shift | (imm << 3);
1147   Inst.addOperand(MCOperand::createImm(Op));
1148 
1149   return S;
1150 }
1151 
1152 static DecodeStatus DecodeSORegRegOperand(MCInst &Inst, unsigned Val,
1153                                uint64_t Address, const void *Decoder) {
1154   DecodeStatus S = MCDisassembler::Success;
1155 
1156   unsigned Rm = fieldFromInstruction(Val, 0, 4);
1157   unsigned type = fieldFromInstruction(Val, 5, 2);
1158   unsigned Rs = fieldFromInstruction(Val, 8, 4);
1159 
1160   // Register-register
1161   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1162     return MCDisassembler::Fail;
1163   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rs, Address, Decoder)))
1164     return MCDisassembler::Fail;
1165 
1166   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1167   switch (type) {
1168     case 0:
1169       Shift = ARM_AM::lsl;
1170       break;
1171     case 1:
1172       Shift = ARM_AM::lsr;
1173       break;
1174     case 2:
1175       Shift = ARM_AM::asr;
1176       break;
1177     case 3:
1178       Shift = ARM_AM::ror;
1179       break;
1180   }
1181 
1182   Inst.addOperand(MCOperand::createImm(Shift));
1183 
1184   return S;
1185 }
1186 
1187 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Val,
1188                                  uint64_t Address, const void *Decoder) {
1189   DecodeStatus S = MCDisassembler::Success;
1190 
1191   bool NeedDisjointWriteback = false;
1192   unsigned WritebackReg = 0;
1193   switch (Inst.getOpcode()) {
1194   default:
1195     break;
1196   case ARM::LDMIA_UPD:
1197   case ARM::LDMDB_UPD:
1198   case ARM::LDMIB_UPD:
1199   case ARM::LDMDA_UPD:
1200   case ARM::t2LDMIA_UPD:
1201   case ARM::t2LDMDB_UPD:
1202   case ARM::t2STMIA_UPD:
1203   case ARM::t2STMDB_UPD:
1204     NeedDisjointWriteback = true;
1205     WritebackReg = Inst.getOperand(0).getReg();
1206     break;
1207   }
1208 
1209   // Empty register lists are not allowed.
1210   if (Val == 0) return MCDisassembler::Fail;
1211   for (unsigned i = 0; i < 16; ++i) {
1212     if (Val & (1 << i)) {
1213       if (!Check(S, DecodeGPRRegisterClass(Inst, i, Address, Decoder)))
1214         return MCDisassembler::Fail;
1215       // Writeback not allowed if Rn is in the target list.
1216       if (NeedDisjointWriteback && WritebackReg == Inst.end()[-1].getReg())
1217         Check(S, MCDisassembler::SoftFail);
1218     }
1219   }
1220 
1221   return S;
1222 }
1223 
1224 static DecodeStatus DecodeSPRRegListOperand(MCInst &Inst, unsigned Val,
1225                                  uint64_t Address, const void *Decoder) {
1226   DecodeStatus S = MCDisassembler::Success;
1227 
1228   unsigned Vd = fieldFromInstruction(Val, 8, 5);
1229   unsigned regs = fieldFromInstruction(Val, 0, 8);
1230 
1231   // In case of unpredictable encoding, tweak the operands.
1232   if (regs == 0 || (Vd + regs) > 32) {
1233     regs = Vd + regs > 32 ? 32 - Vd : regs;
1234     regs = std::max( 1u, regs);
1235     S = MCDisassembler::SoftFail;
1236   }
1237 
1238   if (!Check(S, DecodeSPRRegisterClass(Inst, Vd, Address, Decoder)))
1239     return MCDisassembler::Fail;
1240   for (unsigned i = 0; i < (regs - 1); ++i) {
1241     if (!Check(S, DecodeSPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1242       return MCDisassembler::Fail;
1243   }
1244 
1245   return S;
1246 }
1247 
1248 static DecodeStatus DecodeDPRRegListOperand(MCInst &Inst, unsigned Val,
1249                                  uint64_t Address, const void *Decoder) {
1250   DecodeStatus S = MCDisassembler::Success;
1251 
1252   unsigned Vd = fieldFromInstruction(Val, 8, 5);
1253   unsigned regs = fieldFromInstruction(Val, 1, 7);
1254 
1255   // In case of unpredictable encoding, tweak the operands.
1256   if (regs == 0 || regs > 16 || (Vd + regs) > 32) {
1257     regs = Vd + regs > 32 ? 32 - Vd : regs;
1258     regs = std::max( 1u, regs);
1259     regs = std::min(16u, regs);
1260     S = MCDisassembler::SoftFail;
1261   }
1262 
1263   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
1264       return MCDisassembler::Fail;
1265   for (unsigned i = 0; i < (regs - 1); ++i) {
1266     if (!Check(S, DecodeDPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1267       return MCDisassembler::Fail;
1268   }
1269 
1270   return S;
1271 }
1272 
1273 static DecodeStatus DecodeBitfieldMaskOperand(MCInst &Inst, unsigned Val,
1274                                       uint64_t Address, const void *Decoder) {
1275   // This operand encodes a mask of contiguous zeros between a specified MSB
1276   // and LSB.  To decode it, we create the mask of all bits MSB-and-lower,
1277   // the mask of all bits LSB-and-lower, and then xor them to create
1278   // the mask of that's all ones on [msb, lsb].  Finally we not it to
1279   // create the final mask.
1280   unsigned msb = fieldFromInstruction(Val, 5, 5);
1281   unsigned lsb = fieldFromInstruction(Val, 0, 5);
1282 
1283   DecodeStatus S = MCDisassembler::Success;
1284   if (lsb > msb) {
1285     Check(S, MCDisassembler::SoftFail);
1286     // The check above will cause the warning for the "potentially undefined
1287     // instruction encoding" but we can't build a bad MCOperand value here
1288     // with a lsb > msb or else printing the MCInst will cause a crash.
1289     lsb = msb;
1290   }
1291 
1292   uint32_t msb_mask = 0xFFFFFFFF;
1293   if (msb != 31) msb_mask = (1U << (msb+1)) - 1;
1294   uint32_t lsb_mask = (1U << lsb) - 1;
1295 
1296   Inst.addOperand(MCOperand::createImm(~(msb_mask ^ lsb_mask)));
1297   return S;
1298 }
1299 
1300 static DecodeStatus DecodeCopMemInstruction(MCInst &Inst, unsigned Insn,
1301                                   uint64_t Address, const void *Decoder) {
1302   DecodeStatus S = MCDisassembler::Success;
1303 
1304   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1305   unsigned CRd = fieldFromInstruction(Insn, 12, 4);
1306   unsigned coproc = fieldFromInstruction(Insn, 8, 4);
1307   unsigned imm = fieldFromInstruction(Insn, 0, 8);
1308   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1309   unsigned U = fieldFromInstruction(Insn, 23, 1);
1310 
1311   switch (Inst.getOpcode()) {
1312     case ARM::LDC_OFFSET:
1313     case ARM::LDC_PRE:
1314     case ARM::LDC_POST:
1315     case ARM::LDC_OPTION:
1316     case ARM::LDCL_OFFSET:
1317     case ARM::LDCL_PRE:
1318     case ARM::LDCL_POST:
1319     case ARM::LDCL_OPTION:
1320     case ARM::STC_OFFSET:
1321     case ARM::STC_PRE:
1322     case ARM::STC_POST:
1323     case ARM::STC_OPTION:
1324     case ARM::STCL_OFFSET:
1325     case ARM::STCL_PRE:
1326     case ARM::STCL_POST:
1327     case ARM::STCL_OPTION:
1328     case ARM::t2LDC_OFFSET:
1329     case ARM::t2LDC_PRE:
1330     case ARM::t2LDC_POST:
1331     case ARM::t2LDC_OPTION:
1332     case ARM::t2LDCL_OFFSET:
1333     case ARM::t2LDCL_PRE:
1334     case ARM::t2LDCL_POST:
1335     case ARM::t2LDCL_OPTION:
1336     case ARM::t2STC_OFFSET:
1337     case ARM::t2STC_PRE:
1338     case ARM::t2STC_POST:
1339     case ARM::t2STC_OPTION:
1340     case ARM::t2STCL_OFFSET:
1341     case ARM::t2STCL_PRE:
1342     case ARM::t2STCL_POST:
1343     case ARM::t2STCL_OPTION:
1344       if (coproc == 0xA || coproc == 0xB)
1345         return MCDisassembler::Fail;
1346       break;
1347     default:
1348       break;
1349   }
1350 
1351   const FeatureBitset &featureBits =
1352     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1353   if (featureBits[ARM::HasV8Ops] && (coproc != 14))
1354     return MCDisassembler::Fail;
1355 
1356   Inst.addOperand(MCOperand::createImm(coproc));
1357   Inst.addOperand(MCOperand::createImm(CRd));
1358   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1359     return MCDisassembler::Fail;
1360 
1361   switch (Inst.getOpcode()) {
1362     case ARM::t2LDC2_OFFSET:
1363     case ARM::t2LDC2L_OFFSET:
1364     case ARM::t2LDC2_PRE:
1365     case ARM::t2LDC2L_PRE:
1366     case ARM::t2STC2_OFFSET:
1367     case ARM::t2STC2L_OFFSET:
1368     case ARM::t2STC2_PRE:
1369     case ARM::t2STC2L_PRE:
1370     case ARM::LDC2_OFFSET:
1371     case ARM::LDC2L_OFFSET:
1372     case ARM::LDC2_PRE:
1373     case ARM::LDC2L_PRE:
1374     case ARM::STC2_OFFSET:
1375     case ARM::STC2L_OFFSET:
1376     case ARM::STC2_PRE:
1377     case ARM::STC2L_PRE:
1378     case ARM::t2LDC_OFFSET:
1379     case ARM::t2LDCL_OFFSET:
1380     case ARM::t2LDC_PRE:
1381     case ARM::t2LDCL_PRE:
1382     case ARM::t2STC_OFFSET:
1383     case ARM::t2STCL_OFFSET:
1384     case ARM::t2STC_PRE:
1385     case ARM::t2STCL_PRE:
1386     case ARM::LDC_OFFSET:
1387     case ARM::LDCL_OFFSET:
1388     case ARM::LDC_PRE:
1389     case ARM::LDCL_PRE:
1390     case ARM::STC_OFFSET:
1391     case ARM::STCL_OFFSET:
1392     case ARM::STC_PRE:
1393     case ARM::STCL_PRE:
1394       imm = ARM_AM::getAM5Opc(U ? ARM_AM::add : ARM_AM::sub, imm);
1395       Inst.addOperand(MCOperand::createImm(imm));
1396       break;
1397     case ARM::t2LDC2_POST:
1398     case ARM::t2LDC2L_POST:
1399     case ARM::t2STC2_POST:
1400     case ARM::t2STC2L_POST:
1401     case ARM::LDC2_POST:
1402     case ARM::LDC2L_POST:
1403     case ARM::STC2_POST:
1404     case ARM::STC2L_POST:
1405     case ARM::t2LDC_POST:
1406     case ARM::t2LDCL_POST:
1407     case ARM::t2STC_POST:
1408     case ARM::t2STCL_POST:
1409     case ARM::LDC_POST:
1410     case ARM::LDCL_POST:
1411     case ARM::STC_POST:
1412     case ARM::STCL_POST:
1413       imm |= U << 8;
1414       LLVM_FALLTHROUGH;
1415     default:
1416       // The 'option' variant doesn't encode 'U' in the immediate since
1417       // the immediate is unsigned [0,255].
1418       Inst.addOperand(MCOperand::createImm(imm));
1419       break;
1420   }
1421 
1422   switch (Inst.getOpcode()) {
1423     case ARM::LDC_OFFSET:
1424     case ARM::LDC_PRE:
1425     case ARM::LDC_POST:
1426     case ARM::LDC_OPTION:
1427     case ARM::LDCL_OFFSET:
1428     case ARM::LDCL_PRE:
1429     case ARM::LDCL_POST:
1430     case ARM::LDCL_OPTION:
1431     case ARM::STC_OFFSET:
1432     case ARM::STC_PRE:
1433     case ARM::STC_POST:
1434     case ARM::STC_OPTION:
1435     case ARM::STCL_OFFSET:
1436     case ARM::STCL_PRE:
1437     case ARM::STCL_POST:
1438     case ARM::STCL_OPTION:
1439       if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1440         return MCDisassembler::Fail;
1441       break;
1442     default:
1443       break;
1444   }
1445 
1446   return S;
1447 }
1448 
1449 static DecodeStatus
1450 DecodeAddrMode2IdxInstruction(MCInst &Inst, unsigned Insn,
1451                               uint64_t Address, const void *Decoder) {
1452   DecodeStatus S = MCDisassembler::Success;
1453 
1454   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1455   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
1456   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
1457   unsigned imm = fieldFromInstruction(Insn, 0, 12);
1458   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1459   unsigned reg = fieldFromInstruction(Insn, 25, 1);
1460   unsigned P = fieldFromInstruction(Insn, 24, 1);
1461   unsigned W = fieldFromInstruction(Insn, 21, 1);
1462 
1463   // On stores, the writeback operand precedes Rt.
1464   switch (Inst.getOpcode()) {
1465     case ARM::STR_POST_IMM:
1466     case ARM::STR_POST_REG:
1467     case ARM::STRB_POST_IMM:
1468     case ARM::STRB_POST_REG:
1469     case ARM::STRT_POST_REG:
1470     case ARM::STRT_POST_IMM:
1471     case ARM::STRBT_POST_REG:
1472     case ARM::STRBT_POST_IMM:
1473       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1474         return MCDisassembler::Fail;
1475       break;
1476     default:
1477       break;
1478   }
1479 
1480   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
1481     return MCDisassembler::Fail;
1482 
1483   // On loads, the writeback operand comes after Rt.
1484   switch (Inst.getOpcode()) {
1485     case ARM::LDR_POST_IMM:
1486     case ARM::LDR_POST_REG:
1487     case ARM::LDRB_POST_IMM:
1488     case ARM::LDRB_POST_REG:
1489     case ARM::LDRBT_POST_REG:
1490     case ARM::LDRBT_POST_IMM:
1491     case ARM::LDRT_POST_REG:
1492     case ARM::LDRT_POST_IMM:
1493       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1494         return MCDisassembler::Fail;
1495       break;
1496     default:
1497       break;
1498   }
1499 
1500   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1501     return MCDisassembler::Fail;
1502 
1503   ARM_AM::AddrOpc Op = ARM_AM::add;
1504   if (!fieldFromInstruction(Insn, 23, 1))
1505     Op = ARM_AM::sub;
1506 
1507   bool writeback = (P == 0) || (W == 1);
1508   unsigned idx_mode = 0;
1509   if (P && writeback)
1510     idx_mode = ARMII::IndexModePre;
1511   else if (!P && writeback)
1512     idx_mode = ARMII::IndexModePost;
1513 
1514   if (writeback && (Rn == 15 || Rn == Rt))
1515     S = MCDisassembler::SoftFail; // UNPREDICTABLE
1516 
1517   if (reg) {
1518     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1519       return MCDisassembler::Fail;
1520     ARM_AM::ShiftOpc Opc = ARM_AM::lsl;
1521     switch( fieldFromInstruction(Insn, 5, 2)) {
1522       case 0:
1523         Opc = ARM_AM::lsl;
1524         break;
1525       case 1:
1526         Opc = ARM_AM::lsr;
1527         break;
1528       case 2:
1529         Opc = ARM_AM::asr;
1530         break;
1531       case 3:
1532         Opc = ARM_AM::ror;
1533         break;
1534       default:
1535         return MCDisassembler::Fail;
1536     }
1537     unsigned amt = fieldFromInstruction(Insn, 7, 5);
1538     if (Opc == ARM_AM::ror && amt == 0)
1539       Opc = ARM_AM::rrx;
1540     unsigned imm = ARM_AM::getAM2Opc(Op, amt, Opc, idx_mode);
1541 
1542     Inst.addOperand(MCOperand::createImm(imm));
1543   } else {
1544     Inst.addOperand(MCOperand::createReg(0));
1545     unsigned tmp = ARM_AM::getAM2Opc(Op, imm, ARM_AM::lsl, idx_mode);
1546     Inst.addOperand(MCOperand::createImm(tmp));
1547   }
1548 
1549   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1550     return MCDisassembler::Fail;
1551 
1552   return S;
1553 }
1554 
1555 static DecodeStatus DecodeSORegMemOperand(MCInst &Inst, unsigned Val,
1556                                   uint64_t Address, const void *Decoder) {
1557   DecodeStatus S = MCDisassembler::Success;
1558 
1559   unsigned Rn = fieldFromInstruction(Val, 13, 4);
1560   unsigned Rm = fieldFromInstruction(Val,  0, 4);
1561   unsigned type = fieldFromInstruction(Val, 5, 2);
1562   unsigned imm = fieldFromInstruction(Val, 7, 5);
1563   unsigned U = fieldFromInstruction(Val, 12, 1);
1564 
1565   ARM_AM::ShiftOpc ShOp = ARM_AM::lsl;
1566   switch (type) {
1567     case 0:
1568       ShOp = ARM_AM::lsl;
1569       break;
1570     case 1:
1571       ShOp = ARM_AM::lsr;
1572       break;
1573     case 2:
1574       ShOp = ARM_AM::asr;
1575       break;
1576     case 3:
1577       ShOp = ARM_AM::ror;
1578       break;
1579   }
1580 
1581   if (ShOp == ARM_AM::ror && imm == 0)
1582     ShOp = ARM_AM::rrx;
1583 
1584   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1585     return MCDisassembler::Fail;
1586   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1587     return MCDisassembler::Fail;
1588   unsigned shift;
1589   if (U)
1590     shift = ARM_AM::getAM2Opc(ARM_AM::add, imm, ShOp);
1591   else
1592     shift = ARM_AM::getAM2Opc(ARM_AM::sub, imm, ShOp);
1593   Inst.addOperand(MCOperand::createImm(shift));
1594 
1595   return S;
1596 }
1597 
1598 static DecodeStatus
1599 DecodeAddrMode3Instruction(MCInst &Inst, unsigned Insn,
1600                            uint64_t Address, const void *Decoder) {
1601   DecodeStatus S = MCDisassembler::Success;
1602 
1603   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
1604   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1605   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
1606   unsigned type = fieldFromInstruction(Insn, 22, 1);
1607   unsigned imm = fieldFromInstruction(Insn, 8, 4);
1608   unsigned U = ((~fieldFromInstruction(Insn, 23, 1)) & 1) << 8;
1609   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1610   unsigned W = fieldFromInstruction(Insn, 21, 1);
1611   unsigned P = fieldFromInstruction(Insn, 24, 1);
1612   unsigned Rt2 = Rt + 1;
1613 
1614   bool writeback = (W == 1) | (P == 0);
1615 
1616   // For {LD,ST}RD, Rt must be even, else undefined.
1617   switch (Inst.getOpcode()) {
1618     case ARM::STRD:
1619     case ARM::STRD_PRE:
1620     case ARM::STRD_POST:
1621     case ARM::LDRD:
1622     case ARM::LDRD_PRE:
1623     case ARM::LDRD_POST:
1624       if (Rt & 0x1) S = MCDisassembler::SoftFail;
1625       break;
1626     default:
1627       break;
1628   }
1629   switch (Inst.getOpcode()) {
1630     case ARM::STRD:
1631     case ARM::STRD_PRE:
1632     case ARM::STRD_POST:
1633       if (P == 0 && W == 1)
1634         S = MCDisassembler::SoftFail;
1635 
1636       if (writeback && (Rn == 15 || Rn == Rt || Rn == Rt2))
1637         S = MCDisassembler::SoftFail;
1638       if (type && Rm == 15)
1639         S = MCDisassembler::SoftFail;
1640       if (Rt2 == 15)
1641         S = MCDisassembler::SoftFail;
1642       if (!type && fieldFromInstruction(Insn, 8, 4))
1643         S = MCDisassembler::SoftFail;
1644       break;
1645     case ARM::STRH:
1646     case ARM::STRH_PRE:
1647     case ARM::STRH_POST:
1648       if (Rt == 15)
1649         S = MCDisassembler::SoftFail;
1650       if (writeback && (Rn == 15 || Rn == Rt))
1651         S = MCDisassembler::SoftFail;
1652       if (!type && Rm == 15)
1653         S = MCDisassembler::SoftFail;
1654       break;
1655     case ARM::LDRD:
1656     case ARM::LDRD_PRE:
1657     case ARM::LDRD_POST:
1658       if (type && Rn == 15) {
1659         if (Rt2 == 15)
1660           S = MCDisassembler::SoftFail;
1661         break;
1662       }
1663       if (P == 0 && W == 1)
1664         S = MCDisassembler::SoftFail;
1665       if (!type && (Rt2 == 15 || Rm == 15 || Rm == Rt || Rm == Rt2))
1666         S = MCDisassembler::SoftFail;
1667       if (!type && writeback && Rn == 15)
1668         S = MCDisassembler::SoftFail;
1669       if (writeback && (Rn == Rt || Rn == Rt2))
1670         S = MCDisassembler::SoftFail;
1671       break;
1672     case ARM::LDRH:
1673     case ARM::LDRH_PRE:
1674     case ARM::LDRH_POST:
1675       if (type && Rn == 15) {
1676         if (Rt == 15)
1677           S = MCDisassembler::SoftFail;
1678         break;
1679       }
1680       if (Rt == 15)
1681         S = MCDisassembler::SoftFail;
1682       if (!type && Rm == 15)
1683         S = MCDisassembler::SoftFail;
1684       if (!type && writeback && (Rn == 15 || Rn == Rt))
1685         S = MCDisassembler::SoftFail;
1686       break;
1687     case ARM::LDRSH:
1688     case ARM::LDRSH_PRE:
1689     case ARM::LDRSH_POST:
1690     case ARM::LDRSB:
1691     case ARM::LDRSB_PRE:
1692     case ARM::LDRSB_POST:
1693       if (type && Rn == 15) {
1694         if (Rt == 15)
1695           S = MCDisassembler::SoftFail;
1696         break;
1697       }
1698       if (type && (Rt == 15 || (writeback && Rn == Rt)))
1699         S = MCDisassembler::SoftFail;
1700       if (!type && (Rt == 15 || Rm == 15))
1701         S = MCDisassembler::SoftFail;
1702       if (!type && writeback && (Rn == 15 || Rn == Rt))
1703         S = MCDisassembler::SoftFail;
1704       break;
1705     default:
1706       break;
1707   }
1708 
1709   if (writeback) { // Writeback
1710     if (P)
1711       U |= ARMII::IndexModePre << 9;
1712     else
1713       U |= ARMII::IndexModePost << 9;
1714 
1715     // On stores, the writeback operand precedes Rt.
1716     switch (Inst.getOpcode()) {
1717     case ARM::STRD:
1718     case ARM::STRD_PRE:
1719     case ARM::STRD_POST:
1720     case ARM::STRH:
1721     case ARM::STRH_PRE:
1722     case ARM::STRH_POST:
1723       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1724         return MCDisassembler::Fail;
1725       break;
1726     default:
1727       break;
1728     }
1729   }
1730 
1731   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
1732     return MCDisassembler::Fail;
1733   switch (Inst.getOpcode()) {
1734     case ARM::STRD:
1735     case ARM::STRD_PRE:
1736     case ARM::STRD_POST:
1737     case ARM::LDRD:
1738     case ARM::LDRD_PRE:
1739     case ARM::LDRD_POST:
1740       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder)))
1741         return MCDisassembler::Fail;
1742       break;
1743     default:
1744       break;
1745   }
1746 
1747   if (writeback) {
1748     // On loads, the writeback operand comes after Rt.
1749     switch (Inst.getOpcode()) {
1750     case ARM::LDRD:
1751     case ARM::LDRD_PRE:
1752     case ARM::LDRD_POST:
1753     case ARM::LDRH:
1754     case ARM::LDRH_PRE:
1755     case ARM::LDRH_POST:
1756     case ARM::LDRSH:
1757     case ARM::LDRSH_PRE:
1758     case ARM::LDRSH_POST:
1759     case ARM::LDRSB:
1760     case ARM::LDRSB_PRE:
1761     case ARM::LDRSB_POST:
1762     case ARM::LDRHTr:
1763     case ARM::LDRSBTr:
1764       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1765         return MCDisassembler::Fail;
1766       break;
1767     default:
1768       break;
1769     }
1770   }
1771 
1772   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1773     return MCDisassembler::Fail;
1774 
1775   if (type) {
1776     Inst.addOperand(MCOperand::createReg(0));
1777     Inst.addOperand(MCOperand::createImm(U | (imm << 4) | Rm));
1778   } else {
1779     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1780     return MCDisassembler::Fail;
1781     Inst.addOperand(MCOperand::createImm(U));
1782   }
1783 
1784   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1785     return MCDisassembler::Fail;
1786 
1787   return S;
1788 }
1789 
1790 static DecodeStatus DecodeRFEInstruction(MCInst &Inst, unsigned Insn,
1791                                  uint64_t Address, const void *Decoder) {
1792   DecodeStatus S = MCDisassembler::Success;
1793 
1794   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1795   unsigned mode = fieldFromInstruction(Insn, 23, 2);
1796 
1797   switch (mode) {
1798     case 0:
1799       mode = ARM_AM::da;
1800       break;
1801     case 1:
1802       mode = ARM_AM::ia;
1803       break;
1804     case 2:
1805       mode = ARM_AM::db;
1806       break;
1807     case 3:
1808       mode = ARM_AM::ib;
1809       break;
1810   }
1811 
1812   Inst.addOperand(MCOperand::createImm(mode));
1813   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1814     return MCDisassembler::Fail;
1815 
1816   return S;
1817 }
1818 
1819 static DecodeStatus DecodeQADDInstruction(MCInst &Inst, unsigned Insn,
1820                                uint64_t Address, const void *Decoder) {
1821   DecodeStatus S = MCDisassembler::Success;
1822 
1823   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
1824   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
1825   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1826   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1827 
1828   if (pred == 0xF)
1829     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
1830 
1831   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
1832     return MCDisassembler::Fail;
1833   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1834     return MCDisassembler::Fail;
1835   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
1836     return MCDisassembler::Fail;
1837   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1838     return MCDisassembler::Fail;
1839   return S;
1840 }
1841 
1842 static DecodeStatus DecodeMemMultipleWritebackInstruction(MCInst &Inst,
1843                                   unsigned Insn,
1844                                   uint64_t Address, const void *Decoder) {
1845   DecodeStatus S = MCDisassembler::Success;
1846 
1847   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1848   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1849   unsigned reglist = fieldFromInstruction(Insn, 0, 16);
1850 
1851   if (pred == 0xF) {
1852     // Ambiguous with RFE and SRS
1853     switch (Inst.getOpcode()) {
1854       case ARM::LDMDA:
1855         Inst.setOpcode(ARM::RFEDA);
1856         break;
1857       case ARM::LDMDA_UPD:
1858         Inst.setOpcode(ARM::RFEDA_UPD);
1859         break;
1860       case ARM::LDMDB:
1861         Inst.setOpcode(ARM::RFEDB);
1862         break;
1863       case ARM::LDMDB_UPD:
1864         Inst.setOpcode(ARM::RFEDB_UPD);
1865         break;
1866       case ARM::LDMIA:
1867         Inst.setOpcode(ARM::RFEIA);
1868         break;
1869       case ARM::LDMIA_UPD:
1870         Inst.setOpcode(ARM::RFEIA_UPD);
1871         break;
1872       case ARM::LDMIB:
1873         Inst.setOpcode(ARM::RFEIB);
1874         break;
1875       case ARM::LDMIB_UPD:
1876         Inst.setOpcode(ARM::RFEIB_UPD);
1877         break;
1878       case ARM::STMDA:
1879         Inst.setOpcode(ARM::SRSDA);
1880         break;
1881       case ARM::STMDA_UPD:
1882         Inst.setOpcode(ARM::SRSDA_UPD);
1883         break;
1884       case ARM::STMDB:
1885         Inst.setOpcode(ARM::SRSDB);
1886         break;
1887       case ARM::STMDB_UPD:
1888         Inst.setOpcode(ARM::SRSDB_UPD);
1889         break;
1890       case ARM::STMIA:
1891         Inst.setOpcode(ARM::SRSIA);
1892         break;
1893       case ARM::STMIA_UPD:
1894         Inst.setOpcode(ARM::SRSIA_UPD);
1895         break;
1896       case ARM::STMIB:
1897         Inst.setOpcode(ARM::SRSIB);
1898         break;
1899       case ARM::STMIB_UPD:
1900         Inst.setOpcode(ARM::SRSIB_UPD);
1901         break;
1902       default:
1903         return MCDisassembler::Fail;
1904     }
1905 
1906     // For stores (which become SRS's, the only operand is the mode.
1907     if (fieldFromInstruction(Insn, 20, 1) == 0) {
1908       // Check SRS encoding constraints
1909       if (!(fieldFromInstruction(Insn, 22, 1) == 1 &&
1910             fieldFromInstruction(Insn, 20, 1) == 0))
1911         return MCDisassembler::Fail;
1912 
1913       Inst.addOperand(
1914           MCOperand::createImm(fieldFromInstruction(Insn, 0, 4)));
1915       return S;
1916     }
1917 
1918     return DecodeRFEInstruction(Inst, Insn, Address, Decoder);
1919   }
1920 
1921   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1922     return MCDisassembler::Fail;
1923   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1924     return MCDisassembler::Fail; // Tied
1925   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1926     return MCDisassembler::Fail;
1927   if (!Check(S, DecodeRegListOperand(Inst, reglist, Address, Decoder)))
1928     return MCDisassembler::Fail;
1929 
1930   return S;
1931 }
1932 
1933 // Check for UNPREDICTABLE predicated ESB instruction
1934 static DecodeStatus DecodeHINTInstruction(MCInst &Inst, unsigned Insn,
1935                                  uint64_t Address, const void *Decoder) {
1936   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1937   unsigned imm8 = fieldFromInstruction(Insn, 0, 8);
1938   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
1939   const FeatureBitset &FeatureBits = Dis->getSubtargetInfo().getFeatureBits();
1940 
1941   DecodeStatus S = MCDisassembler::Success;
1942 
1943   Inst.addOperand(MCOperand::createImm(imm8));
1944 
1945   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1946     return MCDisassembler::Fail;
1947 
1948   // ESB is unpredictable if pred != AL. Without the RAS extension, it is a NOP,
1949   // so all predicates should be allowed.
1950   if (imm8 == 0x10 && pred != 0xe && ((FeatureBits[ARM::FeatureRAS]) != 0))
1951     S = MCDisassembler::SoftFail;
1952 
1953   return S;
1954 }
1955 
1956 static DecodeStatus DecodeCPSInstruction(MCInst &Inst, unsigned Insn,
1957                                  uint64_t Address, const void *Decoder) {
1958   unsigned imod = fieldFromInstruction(Insn, 18, 2);
1959   unsigned M = fieldFromInstruction(Insn, 17, 1);
1960   unsigned iflags = fieldFromInstruction(Insn, 6, 3);
1961   unsigned mode = fieldFromInstruction(Insn, 0, 5);
1962 
1963   DecodeStatus S = MCDisassembler::Success;
1964 
1965   // This decoder is called from multiple location that do not check
1966   // the full encoding is valid before they do.
1967   if (fieldFromInstruction(Insn, 5, 1) != 0 ||
1968       fieldFromInstruction(Insn, 16, 1) != 0 ||
1969       fieldFromInstruction(Insn, 20, 8) != 0x10)
1970     return MCDisassembler::Fail;
1971 
1972   // imod == '01' --> UNPREDICTABLE
1973   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
1974   // return failure here.  The '01' imod value is unprintable, so there's
1975   // nothing useful we could do even if we returned UNPREDICTABLE.
1976 
1977   if (imod == 1) return MCDisassembler::Fail;
1978 
1979   if (imod && M) {
1980     Inst.setOpcode(ARM::CPS3p);
1981     Inst.addOperand(MCOperand::createImm(imod));
1982     Inst.addOperand(MCOperand::createImm(iflags));
1983     Inst.addOperand(MCOperand::createImm(mode));
1984   } else if (imod && !M) {
1985     Inst.setOpcode(ARM::CPS2p);
1986     Inst.addOperand(MCOperand::createImm(imod));
1987     Inst.addOperand(MCOperand::createImm(iflags));
1988     if (mode) S = MCDisassembler::SoftFail;
1989   } else if (!imod && M) {
1990     Inst.setOpcode(ARM::CPS1p);
1991     Inst.addOperand(MCOperand::createImm(mode));
1992     if (iflags) S = MCDisassembler::SoftFail;
1993   } else {
1994     // imod == '00' && M == '0' --> UNPREDICTABLE
1995     Inst.setOpcode(ARM::CPS1p);
1996     Inst.addOperand(MCOperand::createImm(mode));
1997     S = MCDisassembler::SoftFail;
1998   }
1999 
2000   return S;
2001 }
2002 
2003 static DecodeStatus DecodeT2CPSInstruction(MCInst &Inst, unsigned Insn,
2004                                  uint64_t Address, const void *Decoder) {
2005   unsigned imod = fieldFromInstruction(Insn, 9, 2);
2006   unsigned M = fieldFromInstruction(Insn, 8, 1);
2007   unsigned iflags = fieldFromInstruction(Insn, 5, 3);
2008   unsigned mode = fieldFromInstruction(Insn, 0, 5);
2009 
2010   DecodeStatus S = MCDisassembler::Success;
2011 
2012   // imod == '01' --> UNPREDICTABLE
2013   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
2014   // return failure here.  The '01' imod value is unprintable, so there's
2015   // nothing useful we could do even if we returned UNPREDICTABLE.
2016 
2017   if (imod == 1) return MCDisassembler::Fail;
2018 
2019   if (imod && M) {
2020     Inst.setOpcode(ARM::t2CPS3p);
2021     Inst.addOperand(MCOperand::createImm(imod));
2022     Inst.addOperand(MCOperand::createImm(iflags));
2023     Inst.addOperand(MCOperand::createImm(mode));
2024   } else if (imod && !M) {
2025     Inst.setOpcode(ARM::t2CPS2p);
2026     Inst.addOperand(MCOperand::createImm(imod));
2027     Inst.addOperand(MCOperand::createImm(iflags));
2028     if (mode) S = MCDisassembler::SoftFail;
2029   } else if (!imod && M) {
2030     Inst.setOpcode(ARM::t2CPS1p);
2031     Inst.addOperand(MCOperand::createImm(mode));
2032     if (iflags) S = MCDisassembler::SoftFail;
2033   } else {
2034     // imod == '00' && M == '0' --> this is a HINT instruction
2035     int imm = fieldFromInstruction(Insn, 0, 8);
2036     // HINT are defined only for immediate in [0..4]
2037     if(imm > 4) return MCDisassembler::Fail;
2038     Inst.setOpcode(ARM::t2HINT);
2039     Inst.addOperand(MCOperand::createImm(imm));
2040   }
2041 
2042   return S;
2043 }
2044 
2045 static DecodeStatus DecodeT2MOVTWInstruction(MCInst &Inst, unsigned Insn,
2046                                  uint64_t Address, const void *Decoder) {
2047   DecodeStatus S = MCDisassembler::Success;
2048 
2049   unsigned Rd = fieldFromInstruction(Insn, 8, 4);
2050   unsigned imm = 0;
2051 
2052   imm |= (fieldFromInstruction(Insn, 0, 8) << 0);
2053   imm |= (fieldFromInstruction(Insn, 12, 3) << 8);
2054   imm |= (fieldFromInstruction(Insn, 16, 4) << 12);
2055   imm |= (fieldFromInstruction(Insn, 26, 1) << 11);
2056 
2057   if (Inst.getOpcode() == ARM::t2MOVTi16)
2058     if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
2059       return MCDisassembler::Fail;
2060   if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
2061     return MCDisassembler::Fail;
2062 
2063   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
2064     Inst.addOperand(MCOperand::createImm(imm));
2065 
2066   return S;
2067 }
2068 
2069 static DecodeStatus DecodeArmMOVTWInstruction(MCInst &Inst, unsigned Insn,
2070                                  uint64_t Address, const void *Decoder) {
2071   DecodeStatus S = MCDisassembler::Success;
2072 
2073   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2074   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2075   unsigned imm = 0;
2076 
2077   imm |= (fieldFromInstruction(Insn, 0, 12) << 0);
2078   imm |= (fieldFromInstruction(Insn, 16, 4) << 12);
2079 
2080   if (Inst.getOpcode() == ARM::MOVTi16)
2081     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2082       return MCDisassembler::Fail;
2083 
2084   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2085     return MCDisassembler::Fail;
2086 
2087   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
2088     Inst.addOperand(MCOperand::createImm(imm));
2089 
2090   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2091     return MCDisassembler::Fail;
2092 
2093   return S;
2094 }
2095 
2096 static DecodeStatus DecodeSMLAInstruction(MCInst &Inst, unsigned Insn,
2097                                  uint64_t Address, const void *Decoder) {
2098   DecodeStatus S = MCDisassembler::Success;
2099 
2100   unsigned Rd = fieldFromInstruction(Insn, 16, 4);
2101   unsigned Rn = fieldFromInstruction(Insn, 0, 4);
2102   unsigned Rm = fieldFromInstruction(Insn, 8, 4);
2103   unsigned Ra = fieldFromInstruction(Insn, 12, 4);
2104   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2105 
2106   if (pred == 0xF)
2107     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
2108 
2109   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2110     return MCDisassembler::Fail;
2111   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
2112     return MCDisassembler::Fail;
2113   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
2114     return MCDisassembler::Fail;
2115   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Ra, Address, Decoder)))
2116     return MCDisassembler::Fail;
2117 
2118   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2119     return MCDisassembler::Fail;
2120 
2121   return S;
2122 }
2123 
2124 static DecodeStatus DecodeTSTInstruction(MCInst &Inst, unsigned Insn,
2125                                   uint64_t Address, const void *Decoder) {
2126   DecodeStatus S = MCDisassembler::Success;
2127 
2128   unsigned Pred = fieldFromInstruction(Insn, 28, 4);
2129   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2130   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2131 
2132   if (Pred == 0xF)
2133     return DecodeSETPANInstruction(Inst, Insn, Address, Decoder);
2134 
2135   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2136     return MCDisassembler::Fail;
2137   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2138     return MCDisassembler::Fail;
2139   if (!Check(S, DecodePredicateOperand(Inst, Pred, Address, Decoder)))
2140     return MCDisassembler::Fail;
2141 
2142   return S;
2143 }
2144 
2145 static DecodeStatus DecodeSETPANInstruction(MCInst &Inst, unsigned Insn,
2146                                   uint64_t Address, const void *Decoder) {
2147   DecodeStatus S = MCDisassembler::Success;
2148 
2149   unsigned Imm = fieldFromInstruction(Insn, 9, 1);
2150 
2151   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
2152   const FeatureBitset &FeatureBits = Dis->getSubtargetInfo().getFeatureBits();
2153 
2154   if (!FeatureBits[ARM::HasV8_1aOps] ||
2155       !FeatureBits[ARM::HasV8Ops])
2156     return MCDisassembler::Fail;
2157 
2158   // Decoder can be called from DecodeTST, which does not check the full
2159   // encoding is valid.
2160   if (fieldFromInstruction(Insn, 20,12) != 0xf11 ||
2161       fieldFromInstruction(Insn, 4,4) != 0)
2162     return MCDisassembler::Fail;
2163   if (fieldFromInstruction(Insn, 10,10) != 0 ||
2164       fieldFromInstruction(Insn, 0,4) != 0)
2165     S = MCDisassembler::SoftFail;
2166 
2167   Inst.setOpcode(ARM::SETPAN);
2168   Inst.addOperand(MCOperand::createImm(Imm));
2169 
2170   return S;
2171 }
2172 
2173 static DecodeStatus DecodeAddrModeImm12Operand(MCInst &Inst, unsigned Val,
2174                            uint64_t Address, const void *Decoder) {
2175   DecodeStatus S = MCDisassembler::Success;
2176 
2177   unsigned add = fieldFromInstruction(Val, 12, 1);
2178   unsigned imm = fieldFromInstruction(Val, 0, 12);
2179   unsigned Rn = fieldFromInstruction(Val, 13, 4);
2180 
2181   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2182     return MCDisassembler::Fail;
2183 
2184   if (!add) imm *= -1;
2185   if (imm == 0 && !add) imm = INT32_MIN;
2186   Inst.addOperand(MCOperand::createImm(imm));
2187   if (Rn == 15)
2188     tryAddingPcLoadReferenceComment(Address, Address + imm + 8, Decoder);
2189 
2190   return S;
2191 }
2192 
2193 static DecodeStatus DecodeAddrMode5Operand(MCInst &Inst, unsigned Val,
2194                                    uint64_t Address, const void *Decoder) {
2195   DecodeStatus S = MCDisassembler::Success;
2196 
2197   unsigned Rn = fieldFromInstruction(Val, 9, 4);
2198   // U == 1 to add imm, 0 to subtract it.
2199   unsigned U = fieldFromInstruction(Val, 8, 1);
2200   unsigned imm = fieldFromInstruction(Val, 0, 8);
2201 
2202   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2203     return MCDisassembler::Fail;
2204 
2205   if (U)
2206     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5Opc(ARM_AM::add, imm)));
2207   else
2208     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5Opc(ARM_AM::sub, imm)));
2209 
2210   return S;
2211 }
2212 
2213 static DecodeStatus DecodeAddrMode5FP16Operand(MCInst &Inst, unsigned Val,
2214                                    uint64_t Address, const void *Decoder) {
2215   DecodeStatus S = MCDisassembler::Success;
2216 
2217   unsigned Rn = fieldFromInstruction(Val, 9, 4);
2218   // U == 1 to add imm, 0 to subtract it.
2219   unsigned U = fieldFromInstruction(Val, 8, 1);
2220   unsigned imm = fieldFromInstruction(Val, 0, 8);
2221 
2222   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2223     return MCDisassembler::Fail;
2224 
2225   if (U)
2226     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5FP16Opc(ARM_AM::add, imm)));
2227   else
2228     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5FP16Opc(ARM_AM::sub, imm)));
2229 
2230   return S;
2231 }
2232 
2233 static DecodeStatus DecodeAddrMode7Operand(MCInst &Inst, unsigned Val,
2234                                    uint64_t Address, const void *Decoder) {
2235   return DecodeGPRRegisterClass(Inst, Val, Address, Decoder);
2236 }
2237 
2238 static DecodeStatus
2239 DecodeT2BInstruction(MCInst &Inst, unsigned Insn,
2240                      uint64_t Address, const void *Decoder) {
2241   DecodeStatus Status = MCDisassembler::Success;
2242 
2243   // Note the J1 and J2 values are from the encoded instruction.  So here
2244   // change them to I1 and I2 values via as documented:
2245   // I1 = NOT(J1 EOR S);
2246   // I2 = NOT(J2 EOR S);
2247   // and build the imm32 with one trailing zero as documented:
2248   // imm32 = SignExtend(S:I1:I2:imm10:imm11:'0', 32);
2249   unsigned S = fieldFromInstruction(Insn, 26, 1);
2250   unsigned J1 = fieldFromInstruction(Insn, 13, 1);
2251   unsigned J2 = fieldFromInstruction(Insn, 11, 1);
2252   unsigned I1 = !(J1 ^ S);
2253   unsigned I2 = !(J2 ^ S);
2254   unsigned imm10 = fieldFromInstruction(Insn, 16, 10);
2255   unsigned imm11 = fieldFromInstruction(Insn, 0, 11);
2256   unsigned tmp = (S << 23) | (I1 << 22) | (I2 << 21) | (imm10 << 11) | imm11;
2257   int imm32 = SignExtend32<25>(tmp << 1);
2258   if (!tryAddingSymbolicOperand(Address, Address + imm32 + 4,
2259                                 true, 4, Inst, Decoder))
2260     Inst.addOperand(MCOperand::createImm(imm32));
2261 
2262   return Status;
2263 }
2264 
2265 static DecodeStatus
2266 DecodeBranchImmInstruction(MCInst &Inst, unsigned Insn,
2267                            uint64_t Address, const void *Decoder) {
2268   DecodeStatus S = MCDisassembler::Success;
2269 
2270   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2271   unsigned imm = fieldFromInstruction(Insn, 0, 24) << 2;
2272 
2273   if (pred == 0xF) {
2274     Inst.setOpcode(ARM::BLXi);
2275     imm |= fieldFromInstruction(Insn, 24, 1) << 1;
2276     if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<26>(imm) + 8,
2277                                   true, 4, Inst, Decoder))
2278     Inst.addOperand(MCOperand::createImm(SignExtend32<26>(imm)));
2279     return S;
2280   }
2281 
2282   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<26>(imm) + 8,
2283                                 true, 4, Inst, Decoder))
2284     Inst.addOperand(MCOperand::createImm(SignExtend32<26>(imm)));
2285   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2286     return MCDisassembler::Fail;
2287 
2288   return S;
2289 }
2290 
2291 static DecodeStatus DecodeAddrMode6Operand(MCInst &Inst, unsigned Val,
2292                                    uint64_t Address, const void *Decoder) {
2293   DecodeStatus S = MCDisassembler::Success;
2294 
2295   unsigned Rm = fieldFromInstruction(Val, 0, 4);
2296   unsigned align = fieldFromInstruction(Val, 4, 2);
2297 
2298   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2299     return MCDisassembler::Fail;
2300   if (!align)
2301     Inst.addOperand(MCOperand::createImm(0));
2302   else
2303     Inst.addOperand(MCOperand::createImm(4 << align));
2304 
2305   return S;
2306 }
2307 
2308 static DecodeStatus DecodeVLDInstruction(MCInst &Inst, unsigned Insn,
2309                                    uint64_t Address, const void *Decoder) {
2310   DecodeStatus S = MCDisassembler::Success;
2311 
2312   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2313   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
2314   unsigned wb = fieldFromInstruction(Insn, 16, 4);
2315   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2316   Rn |= fieldFromInstruction(Insn, 4, 2) << 4;
2317   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2318 
2319   // First output register
2320   switch (Inst.getOpcode()) {
2321   case ARM::VLD1q16: case ARM::VLD1q32: case ARM::VLD1q64: case ARM::VLD1q8:
2322   case ARM::VLD1q16wb_fixed: case ARM::VLD1q16wb_register:
2323   case ARM::VLD1q32wb_fixed: case ARM::VLD1q32wb_register:
2324   case ARM::VLD1q64wb_fixed: case ARM::VLD1q64wb_register:
2325   case ARM::VLD1q8wb_fixed: case ARM::VLD1q8wb_register:
2326   case ARM::VLD2d16: case ARM::VLD2d32: case ARM::VLD2d8:
2327   case ARM::VLD2d16wb_fixed: case ARM::VLD2d16wb_register:
2328   case ARM::VLD2d32wb_fixed: case ARM::VLD2d32wb_register:
2329   case ARM::VLD2d8wb_fixed: case ARM::VLD2d8wb_register:
2330     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
2331       return MCDisassembler::Fail;
2332     break;
2333   case ARM::VLD2b16:
2334   case ARM::VLD2b32:
2335   case ARM::VLD2b8:
2336   case ARM::VLD2b16wb_fixed:
2337   case ARM::VLD2b16wb_register:
2338   case ARM::VLD2b32wb_fixed:
2339   case ARM::VLD2b32wb_register:
2340   case ARM::VLD2b8wb_fixed:
2341   case ARM::VLD2b8wb_register:
2342     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
2343       return MCDisassembler::Fail;
2344     break;
2345   default:
2346     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2347       return MCDisassembler::Fail;
2348   }
2349 
2350   // Second output register
2351   switch (Inst.getOpcode()) {
2352     case ARM::VLD3d8:
2353     case ARM::VLD3d16:
2354     case ARM::VLD3d32:
2355     case ARM::VLD3d8_UPD:
2356     case ARM::VLD3d16_UPD:
2357     case ARM::VLD3d32_UPD:
2358     case ARM::VLD4d8:
2359     case ARM::VLD4d16:
2360     case ARM::VLD4d32:
2361     case ARM::VLD4d8_UPD:
2362     case ARM::VLD4d16_UPD:
2363     case ARM::VLD4d32_UPD:
2364       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
2365         return MCDisassembler::Fail;
2366       break;
2367     case ARM::VLD3q8:
2368     case ARM::VLD3q16:
2369     case ARM::VLD3q32:
2370     case ARM::VLD3q8_UPD:
2371     case ARM::VLD3q16_UPD:
2372     case ARM::VLD3q32_UPD:
2373     case ARM::VLD4q8:
2374     case ARM::VLD4q16:
2375     case ARM::VLD4q32:
2376     case ARM::VLD4q8_UPD:
2377     case ARM::VLD4q16_UPD:
2378     case ARM::VLD4q32_UPD:
2379       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2380         return MCDisassembler::Fail;
2381     default:
2382       break;
2383   }
2384 
2385   // Third output register
2386   switch(Inst.getOpcode()) {
2387     case ARM::VLD3d8:
2388     case ARM::VLD3d16:
2389     case ARM::VLD3d32:
2390     case ARM::VLD3d8_UPD:
2391     case ARM::VLD3d16_UPD:
2392     case ARM::VLD3d32_UPD:
2393     case ARM::VLD4d8:
2394     case ARM::VLD4d16:
2395     case ARM::VLD4d32:
2396     case ARM::VLD4d8_UPD:
2397     case ARM::VLD4d16_UPD:
2398     case ARM::VLD4d32_UPD:
2399       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2400         return MCDisassembler::Fail;
2401       break;
2402     case ARM::VLD3q8:
2403     case ARM::VLD3q16:
2404     case ARM::VLD3q32:
2405     case ARM::VLD3q8_UPD:
2406     case ARM::VLD3q16_UPD:
2407     case ARM::VLD3q32_UPD:
2408     case ARM::VLD4q8:
2409     case ARM::VLD4q16:
2410     case ARM::VLD4q32:
2411     case ARM::VLD4q8_UPD:
2412     case ARM::VLD4q16_UPD:
2413     case ARM::VLD4q32_UPD:
2414       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
2415         return MCDisassembler::Fail;
2416       break;
2417     default:
2418       break;
2419   }
2420 
2421   // Fourth output register
2422   switch (Inst.getOpcode()) {
2423     case ARM::VLD4d8:
2424     case ARM::VLD4d16:
2425     case ARM::VLD4d32:
2426     case ARM::VLD4d8_UPD:
2427     case ARM::VLD4d16_UPD:
2428     case ARM::VLD4d32_UPD:
2429       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
2430         return MCDisassembler::Fail;
2431       break;
2432     case ARM::VLD4q8:
2433     case ARM::VLD4q16:
2434     case ARM::VLD4q32:
2435     case ARM::VLD4q8_UPD:
2436     case ARM::VLD4q16_UPD:
2437     case ARM::VLD4q32_UPD:
2438       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
2439         return MCDisassembler::Fail;
2440       break;
2441     default:
2442       break;
2443   }
2444 
2445   // Writeback operand
2446   switch (Inst.getOpcode()) {
2447     case ARM::VLD1d8wb_fixed:
2448     case ARM::VLD1d16wb_fixed:
2449     case ARM::VLD1d32wb_fixed:
2450     case ARM::VLD1d64wb_fixed:
2451     case ARM::VLD1d8wb_register:
2452     case ARM::VLD1d16wb_register:
2453     case ARM::VLD1d32wb_register:
2454     case ARM::VLD1d64wb_register:
2455     case ARM::VLD1q8wb_fixed:
2456     case ARM::VLD1q16wb_fixed:
2457     case ARM::VLD1q32wb_fixed:
2458     case ARM::VLD1q64wb_fixed:
2459     case ARM::VLD1q8wb_register:
2460     case ARM::VLD1q16wb_register:
2461     case ARM::VLD1q32wb_register:
2462     case ARM::VLD1q64wb_register:
2463     case ARM::VLD1d8Twb_fixed:
2464     case ARM::VLD1d8Twb_register:
2465     case ARM::VLD1d16Twb_fixed:
2466     case ARM::VLD1d16Twb_register:
2467     case ARM::VLD1d32Twb_fixed:
2468     case ARM::VLD1d32Twb_register:
2469     case ARM::VLD1d64Twb_fixed:
2470     case ARM::VLD1d64Twb_register:
2471     case ARM::VLD1d8Qwb_fixed:
2472     case ARM::VLD1d8Qwb_register:
2473     case ARM::VLD1d16Qwb_fixed:
2474     case ARM::VLD1d16Qwb_register:
2475     case ARM::VLD1d32Qwb_fixed:
2476     case ARM::VLD1d32Qwb_register:
2477     case ARM::VLD1d64Qwb_fixed:
2478     case ARM::VLD1d64Qwb_register:
2479     case ARM::VLD2d8wb_fixed:
2480     case ARM::VLD2d16wb_fixed:
2481     case ARM::VLD2d32wb_fixed:
2482     case ARM::VLD2q8wb_fixed:
2483     case ARM::VLD2q16wb_fixed:
2484     case ARM::VLD2q32wb_fixed:
2485     case ARM::VLD2d8wb_register:
2486     case ARM::VLD2d16wb_register:
2487     case ARM::VLD2d32wb_register:
2488     case ARM::VLD2q8wb_register:
2489     case ARM::VLD2q16wb_register:
2490     case ARM::VLD2q32wb_register:
2491     case ARM::VLD2b8wb_fixed:
2492     case ARM::VLD2b16wb_fixed:
2493     case ARM::VLD2b32wb_fixed:
2494     case ARM::VLD2b8wb_register:
2495     case ARM::VLD2b16wb_register:
2496     case ARM::VLD2b32wb_register:
2497       Inst.addOperand(MCOperand::createImm(0));
2498       break;
2499     case ARM::VLD3d8_UPD:
2500     case ARM::VLD3d16_UPD:
2501     case ARM::VLD3d32_UPD:
2502     case ARM::VLD3q8_UPD:
2503     case ARM::VLD3q16_UPD:
2504     case ARM::VLD3q32_UPD:
2505     case ARM::VLD4d8_UPD:
2506     case ARM::VLD4d16_UPD:
2507     case ARM::VLD4d32_UPD:
2508     case ARM::VLD4q8_UPD:
2509     case ARM::VLD4q16_UPD:
2510     case ARM::VLD4q32_UPD:
2511       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
2512         return MCDisassembler::Fail;
2513       break;
2514     default:
2515       break;
2516   }
2517 
2518   // AddrMode6 Base (register+alignment)
2519   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
2520     return MCDisassembler::Fail;
2521 
2522   // AddrMode6 Offset (register)
2523   switch (Inst.getOpcode()) {
2524   default:
2525     // The below have been updated to have explicit am6offset split
2526     // between fixed and register offset. For those instructions not
2527     // yet updated, we need to add an additional reg0 operand for the
2528     // fixed variant.
2529     //
2530     // The fixed offset encodes as Rm == 0xd, so we check for that.
2531     if (Rm == 0xd) {
2532       Inst.addOperand(MCOperand::createReg(0));
2533       break;
2534     }
2535     // Fall through to handle the register offset variant.
2536     LLVM_FALLTHROUGH;
2537   case ARM::VLD1d8wb_fixed:
2538   case ARM::VLD1d16wb_fixed:
2539   case ARM::VLD1d32wb_fixed:
2540   case ARM::VLD1d64wb_fixed:
2541   case ARM::VLD1d8Twb_fixed:
2542   case ARM::VLD1d16Twb_fixed:
2543   case ARM::VLD1d32Twb_fixed:
2544   case ARM::VLD1d64Twb_fixed:
2545   case ARM::VLD1d8Qwb_fixed:
2546   case ARM::VLD1d16Qwb_fixed:
2547   case ARM::VLD1d32Qwb_fixed:
2548   case ARM::VLD1d64Qwb_fixed:
2549   case ARM::VLD1d8wb_register:
2550   case ARM::VLD1d16wb_register:
2551   case ARM::VLD1d32wb_register:
2552   case ARM::VLD1d64wb_register:
2553   case ARM::VLD1q8wb_fixed:
2554   case ARM::VLD1q16wb_fixed:
2555   case ARM::VLD1q32wb_fixed:
2556   case ARM::VLD1q64wb_fixed:
2557   case ARM::VLD1q8wb_register:
2558   case ARM::VLD1q16wb_register:
2559   case ARM::VLD1q32wb_register:
2560   case ARM::VLD1q64wb_register:
2561     // The fixed offset post-increment encodes Rm == 0xd. The no-writeback
2562     // variant encodes Rm == 0xf. Anything else is a register offset post-
2563     // increment and we need to add the register operand to the instruction.
2564     if (Rm != 0xD && Rm != 0xF &&
2565         !Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2566       return MCDisassembler::Fail;
2567     break;
2568   case ARM::VLD2d8wb_fixed:
2569   case ARM::VLD2d16wb_fixed:
2570   case ARM::VLD2d32wb_fixed:
2571   case ARM::VLD2b8wb_fixed:
2572   case ARM::VLD2b16wb_fixed:
2573   case ARM::VLD2b32wb_fixed:
2574   case ARM::VLD2q8wb_fixed:
2575   case ARM::VLD2q16wb_fixed:
2576   case ARM::VLD2q32wb_fixed:
2577     break;
2578   }
2579 
2580   return S;
2581 }
2582 
2583 static DecodeStatus DecodeVLDST1Instruction(MCInst &Inst, unsigned Insn,
2584                                    uint64_t Address, const void *Decoder) {
2585   unsigned type = fieldFromInstruction(Insn, 8, 4);
2586   unsigned align = fieldFromInstruction(Insn, 4, 2);
2587   if (type == 6 && (align & 2)) return MCDisassembler::Fail;
2588   if (type == 7 && (align & 2)) return MCDisassembler::Fail;
2589   if (type == 10 && align == 3) return MCDisassembler::Fail;
2590 
2591   unsigned load = fieldFromInstruction(Insn, 21, 1);
2592   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2593               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2594 }
2595 
2596 static DecodeStatus DecodeVLDST2Instruction(MCInst &Inst, unsigned Insn,
2597                                    uint64_t Address, const void *Decoder) {
2598   unsigned size = fieldFromInstruction(Insn, 6, 2);
2599   if (size == 3) return MCDisassembler::Fail;
2600 
2601   unsigned type = fieldFromInstruction(Insn, 8, 4);
2602   unsigned align = fieldFromInstruction(Insn, 4, 2);
2603   if (type == 8 && align == 3) return MCDisassembler::Fail;
2604   if (type == 9 && align == 3) return MCDisassembler::Fail;
2605 
2606   unsigned load = fieldFromInstruction(Insn, 21, 1);
2607   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2608               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2609 }
2610 
2611 static DecodeStatus DecodeVLDST3Instruction(MCInst &Inst, unsigned Insn,
2612                                    uint64_t Address, const void *Decoder) {
2613   unsigned size = fieldFromInstruction(Insn, 6, 2);
2614   if (size == 3) return MCDisassembler::Fail;
2615 
2616   unsigned align = fieldFromInstruction(Insn, 4, 2);
2617   if (align & 2) return MCDisassembler::Fail;
2618 
2619   unsigned load = fieldFromInstruction(Insn, 21, 1);
2620   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2621               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2622 }
2623 
2624 static DecodeStatus DecodeVLDST4Instruction(MCInst &Inst, unsigned Insn,
2625                                    uint64_t Address, const void *Decoder) {
2626   unsigned size = fieldFromInstruction(Insn, 6, 2);
2627   if (size == 3) return MCDisassembler::Fail;
2628 
2629   unsigned load = fieldFromInstruction(Insn, 21, 1);
2630   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2631               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2632 }
2633 
2634 static DecodeStatus DecodeVSTInstruction(MCInst &Inst, unsigned Insn,
2635                                  uint64_t Address, const void *Decoder) {
2636   DecodeStatus S = MCDisassembler::Success;
2637 
2638   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2639   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
2640   unsigned wb = fieldFromInstruction(Insn, 16, 4);
2641   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2642   Rn |= fieldFromInstruction(Insn, 4, 2) << 4;
2643   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2644 
2645   // Writeback Operand
2646   switch (Inst.getOpcode()) {
2647     case ARM::VST1d8wb_fixed:
2648     case ARM::VST1d16wb_fixed:
2649     case ARM::VST1d32wb_fixed:
2650     case ARM::VST1d64wb_fixed:
2651     case ARM::VST1d8wb_register:
2652     case ARM::VST1d16wb_register:
2653     case ARM::VST1d32wb_register:
2654     case ARM::VST1d64wb_register:
2655     case ARM::VST1q8wb_fixed:
2656     case ARM::VST1q16wb_fixed:
2657     case ARM::VST1q32wb_fixed:
2658     case ARM::VST1q64wb_fixed:
2659     case ARM::VST1q8wb_register:
2660     case ARM::VST1q16wb_register:
2661     case ARM::VST1q32wb_register:
2662     case ARM::VST1q64wb_register:
2663     case ARM::VST1d8Twb_fixed:
2664     case ARM::VST1d16Twb_fixed:
2665     case ARM::VST1d32Twb_fixed:
2666     case ARM::VST1d64Twb_fixed:
2667     case ARM::VST1d8Twb_register:
2668     case ARM::VST1d16Twb_register:
2669     case ARM::VST1d32Twb_register:
2670     case ARM::VST1d64Twb_register:
2671     case ARM::VST1d8Qwb_fixed:
2672     case ARM::VST1d16Qwb_fixed:
2673     case ARM::VST1d32Qwb_fixed:
2674     case ARM::VST1d64Qwb_fixed:
2675     case ARM::VST1d8Qwb_register:
2676     case ARM::VST1d16Qwb_register:
2677     case ARM::VST1d32Qwb_register:
2678     case ARM::VST1d64Qwb_register:
2679     case ARM::VST2d8wb_fixed:
2680     case ARM::VST2d16wb_fixed:
2681     case ARM::VST2d32wb_fixed:
2682     case ARM::VST2d8wb_register:
2683     case ARM::VST2d16wb_register:
2684     case ARM::VST2d32wb_register:
2685     case ARM::VST2q8wb_fixed:
2686     case ARM::VST2q16wb_fixed:
2687     case ARM::VST2q32wb_fixed:
2688     case ARM::VST2q8wb_register:
2689     case ARM::VST2q16wb_register:
2690     case ARM::VST2q32wb_register:
2691     case ARM::VST2b8wb_fixed:
2692     case ARM::VST2b16wb_fixed:
2693     case ARM::VST2b32wb_fixed:
2694     case ARM::VST2b8wb_register:
2695     case ARM::VST2b16wb_register:
2696     case ARM::VST2b32wb_register:
2697       if (Rm == 0xF)
2698         return MCDisassembler::Fail;
2699       Inst.addOperand(MCOperand::createImm(0));
2700       break;
2701     case ARM::VST3d8_UPD:
2702     case ARM::VST3d16_UPD:
2703     case ARM::VST3d32_UPD:
2704     case ARM::VST3q8_UPD:
2705     case ARM::VST3q16_UPD:
2706     case ARM::VST3q32_UPD:
2707     case ARM::VST4d8_UPD:
2708     case ARM::VST4d16_UPD:
2709     case ARM::VST4d32_UPD:
2710     case ARM::VST4q8_UPD:
2711     case ARM::VST4q16_UPD:
2712     case ARM::VST4q32_UPD:
2713       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
2714         return MCDisassembler::Fail;
2715       break;
2716     default:
2717       break;
2718   }
2719 
2720   // AddrMode6 Base (register+alignment)
2721   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
2722     return MCDisassembler::Fail;
2723 
2724   // AddrMode6 Offset (register)
2725   switch (Inst.getOpcode()) {
2726     default:
2727       if (Rm == 0xD)
2728         Inst.addOperand(MCOperand::createReg(0));
2729       else if (Rm != 0xF) {
2730         if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2731           return MCDisassembler::Fail;
2732       }
2733       break;
2734     case ARM::VST1d8wb_fixed:
2735     case ARM::VST1d16wb_fixed:
2736     case ARM::VST1d32wb_fixed:
2737     case ARM::VST1d64wb_fixed:
2738     case ARM::VST1q8wb_fixed:
2739     case ARM::VST1q16wb_fixed:
2740     case ARM::VST1q32wb_fixed:
2741     case ARM::VST1q64wb_fixed:
2742     case ARM::VST1d8Twb_fixed:
2743     case ARM::VST1d16Twb_fixed:
2744     case ARM::VST1d32Twb_fixed:
2745     case ARM::VST1d64Twb_fixed:
2746     case ARM::VST1d8Qwb_fixed:
2747     case ARM::VST1d16Qwb_fixed:
2748     case ARM::VST1d32Qwb_fixed:
2749     case ARM::VST1d64Qwb_fixed:
2750     case ARM::VST2d8wb_fixed:
2751     case ARM::VST2d16wb_fixed:
2752     case ARM::VST2d32wb_fixed:
2753     case ARM::VST2q8wb_fixed:
2754     case ARM::VST2q16wb_fixed:
2755     case ARM::VST2q32wb_fixed:
2756     case ARM::VST2b8wb_fixed:
2757     case ARM::VST2b16wb_fixed:
2758     case ARM::VST2b32wb_fixed:
2759       break;
2760   }
2761 
2762 
2763   // First input register
2764   switch (Inst.getOpcode()) {
2765   case ARM::VST1q16:
2766   case ARM::VST1q32:
2767   case ARM::VST1q64:
2768   case ARM::VST1q8:
2769   case ARM::VST1q16wb_fixed:
2770   case ARM::VST1q16wb_register:
2771   case ARM::VST1q32wb_fixed:
2772   case ARM::VST1q32wb_register:
2773   case ARM::VST1q64wb_fixed:
2774   case ARM::VST1q64wb_register:
2775   case ARM::VST1q8wb_fixed:
2776   case ARM::VST1q8wb_register:
2777   case ARM::VST2d16:
2778   case ARM::VST2d32:
2779   case ARM::VST2d8:
2780   case ARM::VST2d16wb_fixed:
2781   case ARM::VST2d16wb_register:
2782   case ARM::VST2d32wb_fixed:
2783   case ARM::VST2d32wb_register:
2784   case ARM::VST2d8wb_fixed:
2785   case ARM::VST2d8wb_register:
2786     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
2787       return MCDisassembler::Fail;
2788     break;
2789   case ARM::VST2b16:
2790   case ARM::VST2b32:
2791   case ARM::VST2b8:
2792   case ARM::VST2b16wb_fixed:
2793   case ARM::VST2b16wb_register:
2794   case ARM::VST2b32wb_fixed:
2795   case ARM::VST2b32wb_register:
2796   case ARM::VST2b8wb_fixed:
2797   case ARM::VST2b8wb_register:
2798     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
2799       return MCDisassembler::Fail;
2800     break;
2801   default:
2802     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2803       return MCDisassembler::Fail;
2804   }
2805 
2806   // Second input register
2807   switch (Inst.getOpcode()) {
2808     case ARM::VST3d8:
2809     case ARM::VST3d16:
2810     case ARM::VST3d32:
2811     case ARM::VST3d8_UPD:
2812     case ARM::VST3d16_UPD:
2813     case ARM::VST3d32_UPD:
2814     case ARM::VST4d8:
2815     case ARM::VST4d16:
2816     case ARM::VST4d32:
2817     case ARM::VST4d8_UPD:
2818     case ARM::VST4d16_UPD:
2819     case ARM::VST4d32_UPD:
2820       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
2821         return MCDisassembler::Fail;
2822       break;
2823     case ARM::VST3q8:
2824     case ARM::VST3q16:
2825     case ARM::VST3q32:
2826     case ARM::VST3q8_UPD:
2827     case ARM::VST3q16_UPD:
2828     case ARM::VST3q32_UPD:
2829     case ARM::VST4q8:
2830     case ARM::VST4q16:
2831     case ARM::VST4q32:
2832     case ARM::VST4q8_UPD:
2833     case ARM::VST4q16_UPD:
2834     case ARM::VST4q32_UPD:
2835       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2836         return MCDisassembler::Fail;
2837       break;
2838     default:
2839       break;
2840   }
2841 
2842   // Third input register
2843   switch (Inst.getOpcode()) {
2844     case ARM::VST3d8:
2845     case ARM::VST3d16:
2846     case ARM::VST3d32:
2847     case ARM::VST3d8_UPD:
2848     case ARM::VST3d16_UPD:
2849     case ARM::VST3d32_UPD:
2850     case ARM::VST4d8:
2851     case ARM::VST4d16:
2852     case ARM::VST4d32:
2853     case ARM::VST4d8_UPD:
2854     case ARM::VST4d16_UPD:
2855     case ARM::VST4d32_UPD:
2856       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2857         return MCDisassembler::Fail;
2858       break;
2859     case ARM::VST3q8:
2860     case ARM::VST3q16:
2861     case ARM::VST3q32:
2862     case ARM::VST3q8_UPD:
2863     case ARM::VST3q16_UPD:
2864     case ARM::VST3q32_UPD:
2865     case ARM::VST4q8:
2866     case ARM::VST4q16:
2867     case ARM::VST4q32:
2868     case ARM::VST4q8_UPD:
2869     case ARM::VST4q16_UPD:
2870     case ARM::VST4q32_UPD:
2871       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
2872         return MCDisassembler::Fail;
2873       break;
2874     default:
2875       break;
2876   }
2877 
2878   // Fourth input register
2879   switch (Inst.getOpcode()) {
2880     case ARM::VST4d8:
2881     case ARM::VST4d16:
2882     case ARM::VST4d32:
2883     case ARM::VST4d8_UPD:
2884     case ARM::VST4d16_UPD:
2885     case ARM::VST4d32_UPD:
2886       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
2887         return MCDisassembler::Fail;
2888       break;
2889     case ARM::VST4q8:
2890     case ARM::VST4q16:
2891     case ARM::VST4q32:
2892     case ARM::VST4q8_UPD:
2893     case ARM::VST4q16_UPD:
2894     case ARM::VST4q32_UPD:
2895       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
2896         return MCDisassembler::Fail;
2897       break;
2898     default:
2899       break;
2900   }
2901 
2902   return S;
2903 }
2904 
2905 static DecodeStatus DecodeVLD1DupInstruction(MCInst &Inst, unsigned Insn,
2906                                     uint64_t Address, const void *Decoder) {
2907   DecodeStatus S = MCDisassembler::Success;
2908 
2909   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2910   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
2911   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2912   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2913   unsigned align = fieldFromInstruction(Insn, 4, 1);
2914   unsigned size = fieldFromInstruction(Insn, 6, 2);
2915 
2916   if (size == 0 && align == 1)
2917     return MCDisassembler::Fail;
2918   align *= (1 << size);
2919 
2920   switch (Inst.getOpcode()) {
2921   case ARM::VLD1DUPq16: case ARM::VLD1DUPq32: case ARM::VLD1DUPq8:
2922   case ARM::VLD1DUPq16wb_fixed: case ARM::VLD1DUPq16wb_register:
2923   case ARM::VLD1DUPq32wb_fixed: case ARM::VLD1DUPq32wb_register:
2924   case ARM::VLD1DUPq8wb_fixed: case ARM::VLD1DUPq8wb_register:
2925     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
2926       return MCDisassembler::Fail;
2927     break;
2928   default:
2929     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2930       return MCDisassembler::Fail;
2931     break;
2932   }
2933   if (Rm != 0xF) {
2934     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2935       return MCDisassembler::Fail;
2936   }
2937 
2938   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2939     return MCDisassembler::Fail;
2940   Inst.addOperand(MCOperand::createImm(align));
2941 
2942   // The fixed offset post-increment encodes Rm == 0xd. The no-writeback
2943   // variant encodes Rm == 0xf. Anything else is a register offset post-
2944   // increment and we need to add the register operand to the instruction.
2945   if (Rm != 0xD && Rm != 0xF &&
2946       !Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2947     return MCDisassembler::Fail;
2948 
2949   return S;
2950 }
2951 
2952 static DecodeStatus DecodeVLD2DupInstruction(MCInst &Inst, unsigned Insn,
2953                                     uint64_t Address, const void *Decoder) {
2954   DecodeStatus S = MCDisassembler::Success;
2955 
2956   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2957   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
2958   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2959   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2960   unsigned align = fieldFromInstruction(Insn, 4, 1);
2961   unsigned size = 1 << fieldFromInstruction(Insn, 6, 2);
2962   align *= 2*size;
2963 
2964   switch (Inst.getOpcode()) {
2965   case ARM::VLD2DUPd16: case ARM::VLD2DUPd32: case ARM::VLD2DUPd8:
2966   case ARM::VLD2DUPd16wb_fixed: case ARM::VLD2DUPd16wb_register:
2967   case ARM::VLD2DUPd32wb_fixed: case ARM::VLD2DUPd32wb_register:
2968   case ARM::VLD2DUPd8wb_fixed: case ARM::VLD2DUPd8wb_register:
2969     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
2970       return MCDisassembler::Fail;
2971     break;
2972   case ARM::VLD2DUPd16x2: case ARM::VLD2DUPd32x2: case ARM::VLD2DUPd8x2:
2973   case ARM::VLD2DUPd16x2wb_fixed: case ARM::VLD2DUPd16x2wb_register:
2974   case ARM::VLD2DUPd32x2wb_fixed: case ARM::VLD2DUPd32x2wb_register:
2975   case ARM::VLD2DUPd8x2wb_fixed: case ARM::VLD2DUPd8x2wb_register:
2976     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
2977       return MCDisassembler::Fail;
2978     break;
2979   default:
2980     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2981       return MCDisassembler::Fail;
2982     break;
2983   }
2984 
2985   if (Rm != 0xF)
2986     Inst.addOperand(MCOperand::createImm(0));
2987 
2988   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2989     return MCDisassembler::Fail;
2990   Inst.addOperand(MCOperand::createImm(align));
2991 
2992   if (Rm != 0xD && Rm != 0xF) {
2993     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2994       return MCDisassembler::Fail;
2995   }
2996 
2997   return S;
2998 }
2999 
3000 static DecodeStatus DecodeVLD3DupInstruction(MCInst &Inst, unsigned Insn,
3001                                     uint64_t Address, const void *Decoder) {
3002   DecodeStatus S = MCDisassembler::Success;
3003 
3004   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3005   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3006   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3007   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3008   unsigned inc = fieldFromInstruction(Insn, 5, 1) + 1;
3009 
3010   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3011     return MCDisassembler::Fail;
3012   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
3013     return MCDisassembler::Fail;
3014   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
3015     return MCDisassembler::Fail;
3016   if (Rm != 0xF) {
3017     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3018       return MCDisassembler::Fail;
3019   }
3020 
3021   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3022     return MCDisassembler::Fail;
3023   Inst.addOperand(MCOperand::createImm(0));
3024 
3025   if (Rm == 0xD)
3026     Inst.addOperand(MCOperand::createReg(0));
3027   else if (Rm != 0xF) {
3028     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3029       return MCDisassembler::Fail;
3030   }
3031 
3032   return S;
3033 }
3034 
3035 static DecodeStatus DecodeVLD4DupInstruction(MCInst &Inst, unsigned Insn,
3036                                     uint64_t Address, const void *Decoder) {
3037   DecodeStatus S = MCDisassembler::Success;
3038 
3039   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3040   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3041   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3042   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3043   unsigned size = fieldFromInstruction(Insn, 6, 2);
3044   unsigned inc = fieldFromInstruction(Insn, 5, 1) + 1;
3045   unsigned align = fieldFromInstruction(Insn, 4, 1);
3046 
3047   if (size == 0x3) {
3048     if (align == 0)
3049       return MCDisassembler::Fail;
3050     align = 16;
3051   } else {
3052     if (size == 2) {
3053       align *= 8;
3054     } else {
3055       size = 1 << size;
3056       align *= 4*size;
3057     }
3058   }
3059 
3060   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3061     return MCDisassembler::Fail;
3062   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
3063     return MCDisassembler::Fail;
3064   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
3065     return MCDisassembler::Fail;
3066   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3*inc)%32, Address, Decoder)))
3067     return MCDisassembler::Fail;
3068   if (Rm != 0xF) {
3069     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3070       return MCDisassembler::Fail;
3071   }
3072 
3073   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3074     return MCDisassembler::Fail;
3075   Inst.addOperand(MCOperand::createImm(align));
3076 
3077   if (Rm == 0xD)
3078     Inst.addOperand(MCOperand::createReg(0));
3079   else if (Rm != 0xF) {
3080     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3081       return MCDisassembler::Fail;
3082   }
3083 
3084   return S;
3085 }
3086 
3087 static DecodeStatus
3088 DecodeNEONModImmInstruction(MCInst &Inst, unsigned Insn,
3089                             uint64_t Address, const void *Decoder) {
3090   DecodeStatus S = MCDisassembler::Success;
3091 
3092   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3093   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3094   unsigned imm = fieldFromInstruction(Insn, 0, 4);
3095   imm |= fieldFromInstruction(Insn, 16, 3) << 4;
3096   imm |= fieldFromInstruction(Insn, 24, 1) << 7;
3097   imm |= fieldFromInstruction(Insn, 8, 4) << 8;
3098   imm |= fieldFromInstruction(Insn, 5, 1) << 12;
3099   unsigned Q = fieldFromInstruction(Insn, 6, 1);
3100 
3101   if (Q) {
3102     if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3103     return MCDisassembler::Fail;
3104   } else {
3105     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3106     return MCDisassembler::Fail;
3107   }
3108 
3109   Inst.addOperand(MCOperand::createImm(imm));
3110 
3111   switch (Inst.getOpcode()) {
3112     case ARM::VORRiv4i16:
3113     case ARM::VORRiv2i32:
3114     case ARM::VBICiv4i16:
3115     case ARM::VBICiv2i32:
3116       if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3117         return MCDisassembler::Fail;
3118       break;
3119     case ARM::VORRiv8i16:
3120     case ARM::VORRiv4i32:
3121     case ARM::VBICiv8i16:
3122     case ARM::VBICiv4i32:
3123       if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3124         return MCDisassembler::Fail;
3125       break;
3126     default:
3127       break;
3128   }
3129 
3130   return S;
3131 }
3132 
3133 static DecodeStatus DecodeVSHLMaxInstruction(MCInst &Inst, unsigned Insn,
3134                                         uint64_t Address, const void *Decoder) {
3135   DecodeStatus S = MCDisassembler::Success;
3136 
3137   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3138   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3139   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3140   Rm |= fieldFromInstruction(Insn, 5, 1) << 4;
3141   unsigned size = fieldFromInstruction(Insn, 18, 2);
3142 
3143   if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3144     return MCDisassembler::Fail;
3145   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
3146     return MCDisassembler::Fail;
3147   Inst.addOperand(MCOperand::createImm(8 << size));
3148 
3149   return S;
3150 }
3151 
3152 static DecodeStatus DecodeShiftRight8Imm(MCInst &Inst, unsigned Val,
3153                                uint64_t Address, const void *Decoder) {
3154   Inst.addOperand(MCOperand::createImm(8 - Val));
3155   return MCDisassembler::Success;
3156 }
3157 
3158 static DecodeStatus DecodeShiftRight16Imm(MCInst &Inst, unsigned Val,
3159                                uint64_t Address, const void *Decoder) {
3160   Inst.addOperand(MCOperand::createImm(16 - Val));
3161   return MCDisassembler::Success;
3162 }
3163 
3164 static DecodeStatus DecodeShiftRight32Imm(MCInst &Inst, unsigned Val,
3165                                uint64_t Address, const void *Decoder) {
3166   Inst.addOperand(MCOperand::createImm(32 - Val));
3167   return MCDisassembler::Success;
3168 }
3169 
3170 static DecodeStatus DecodeShiftRight64Imm(MCInst &Inst, unsigned Val,
3171                                uint64_t Address, const void *Decoder) {
3172   Inst.addOperand(MCOperand::createImm(64 - Val));
3173   return MCDisassembler::Success;
3174 }
3175 
3176 static DecodeStatus DecodeTBLInstruction(MCInst &Inst, unsigned Insn,
3177                                uint64_t Address, const void *Decoder) {
3178   DecodeStatus S = MCDisassembler::Success;
3179 
3180   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3181   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3182   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3183   Rn |= fieldFromInstruction(Insn, 7, 1) << 4;
3184   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3185   Rm |= fieldFromInstruction(Insn, 5, 1) << 4;
3186   unsigned op = fieldFromInstruction(Insn, 6, 1);
3187 
3188   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3189     return MCDisassembler::Fail;
3190   if (op) {
3191     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3192     return MCDisassembler::Fail; // Writeback
3193   }
3194 
3195   switch (Inst.getOpcode()) {
3196   case ARM::VTBL2:
3197   case ARM::VTBX2:
3198     if (!Check(S, DecodeDPairRegisterClass(Inst, Rn, Address, Decoder)))
3199       return MCDisassembler::Fail;
3200     break;
3201   default:
3202     if (!Check(S, DecodeDPRRegisterClass(Inst, Rn, Address, Decoder)))
3203       return MCDisassembler::Fail;
3204   }
3205 
3206   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
3207     return MCDisassembler::Fail;
3208 
3209   return S;
3210 }
3211 
3212 static DecodeStatus DecodeThumbAddSpecialReg(MCInst &Inst, uint16_t Insn,
3213                                      uint64_t Address, const void *Decoder) {
3214   DecodeStatus S = MCDisassembler::Success;
3215 
3216   unsigned dst = fieldFromInstruction(Insn, 8, 3);
3217   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3218 
3219   if (!Check(S, DecodetGPRRegisterClass(Inst, dst, Address, Decoder)))
3220     return MCDisassembler::Fail;
3221 
3222   switch(Inst.getOpcode()) {
3223     default:
3224       return MCDisassembler::Fail;
3225     case ARM::tADR:
3226       break; // tADR does not explicitly represent the PC as an operand.
3227     case ARM::tADDrSPi:
3228       Inst.addOperand(MCOperand::createReg(ARM::SP));
3229       break;
3230   }
3231 
3232   Inst.addOperand(MCOperand::createImm(imm));
3233   return S;
3234 }
3235 
3236 static DecodeStatus DecodeThumbBROperand(MCInst &Inst, unsigned Val,
3237                                  uint64_t Address, const void *Decoder) {
3238   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<12>(Val<<1) + 4,
3239                                 true, 2, Inst, Decoder))
3240     Inst.addOperand(MCOperand::createImm(SignExtend32<12>(Val << 1)));
3241   return MCDisassembler::Success;
3242 }
3243 
3244 static DecodeStatus DecodeT2BROperand(MCInst &Inst, unsigned Val,
3245                                  uint64_t Address, const void *Decoder) {
3246   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<21>(Val) + 4,
3247                                 true, 4, Inst, Decoder))
3248     Inst.addOperand(MCOperand::createImm(SignExtend32<21>(Val)));
3249   return MCDisassembler::Success;
3250 }
3251 
3252 static DecodeStatus DecodeThumbCmpBROperand(MCInst &Inst, unsigned Val,
3253                                  uint64_t Address, const void *Decoder) {
3254   if (!tryAddingSymbolicOperand(Address, Address + (Val<<1) + 4,
3255                                 true, 2, Inst, Decoder))
3256     Inst.addOperand(MCOperand::createImm(Val << 1));
3257   return MCDisassembler::Success;
3258 }
3259 
3260 static DecodeStatus DecodeThumbAddrModeRR(MCInst &Inst, unsigned Val,
3261                                  uint64_t Address, const void *Decoder) {
3262   DecodeStatus S = MCDisassembler::Success;
3263 
3264   unsigned Rn = fieldFromInstruction(Val, 0, 3);
3265   unsigned Rm = fieldFromInstruction(Val, 3, 3);
3266 
3267   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
3268     return MCDisassembler::Fail;
3269   if (!Check(S, DecodetGPRRegisterClass(Inst, Rm, Address, Decoder)))
3270     return MCDisassembler::Fail;
3271 
3272   return S;
3273 }
3274 
3275 static DecodeStatus DecodeThumbAddrModeIS(MCInst &Inst, unsigned Val,
3276                                   uint64_t Address, const void *Decoder) {
3277   DecodeStatus S = MCDisassembler::Success;
3278 
3279   unsigned Rn = fieldFromInstruction(Val, 0, 3);
3280   unsigned imm = fieldFromInstruction(Val, 3, 5);
3281 
3282   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
3283     return MCDisassembler::Fail;
3284   Inst.addOperand(MCOperand::createImm(imm));
3285 
3286   return S;
3287 }
3288 
3289 static DecodeStatus DecodeThumbAddrModePC(MCInst &Inst, unsigned Val,
3290                                   uint64_t Address, const void *Decoder) {
3291   unsigned imm = Val << 2;
3292 
3293   Inst.addOperand(MCOperand::createImm(imm));
3294   tryAddingPcLoadReferenceComment(Address, (Address & ~2u) + imm + 4, Decoder);
3295 
3296   return MCDisassembler::Success;
3297 }
3298 
3299 static DecodeStatus DecodeThumbAddrModeSP(MCInst &Inst, unsigned Val,
3300                                   uint64_t Address, const void *Decoder) {
3301   Inst.addOperand(MCOperand::createReg(ARM::SP));
3302   Inst.addOperand(MCOperand::createImm(Val));
3303 
3304   return MCDisassembler::Success;
3305 }
3306 
3307 static DecodeStatus DecodeT2AddrModeSOReg(MCInst &Inst, unsigned Val,
3308                                   uint64_t Address, const void *Decoder) {
3309   DecodeStatus S = MCDisassembler::Success;
3310 
3311   unsigned Rn = fieldFromInstruction(Val, 6, 4);
3312   unsigned Rm = fieldFromInstruction(Val, 2, 4);
3313   unsigned imm = fieldFromInstruction(Val, 0, 2);
3314 
3315   // Thumb stores cannot use PC as dest register.
3316   switch (Inst.getOpcode()) {
3317   case ARM::t2STRHs:
3318   case ARM::t2STRBs:
3319   case ARM::t2STRs:
3320     if (Rn == 15)
3321       return MCDisassembler::Fail;
3322   default:
3323     break;
3324   }
3325 
3326   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3327     return MCDisassembler::Fail;
3328   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
3329     return MCDisassembler::Fail;
3330   Inst.addOperand(MCOperand::createImm(imm));
3331 
3332   return S;
3333 }
3334 
3335 static DecodeStatus DecodeT2LoadShift(MCInst &Inst, unsigned Insn,
3336                               uint64_t Address, const void *Decoder) {
3337   DecodeStatus S = MCDisassembler::Success;
3338 
3339   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3340   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3341 
3342   const FeatureBitset &featureBits =
3343     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3344 
3345   bool hasMP = featureBits[ARM::FeatureMP];
3346   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3347 
3348   if (Rn == 15) {
3349     switch (Inst.getOpcode()) {
3350     case ARM::t2LDRBs:
3351       Inst.setOpcode(ARM::t2LDRBpci);
3352       break;
3353     case ARM::t2LDRHs:
3354       Inst.setOpcode(ARM::t2LDRHpci);
3355       break;
3356     case ARM::t2LDRSHs:
3357       Inst.setOpcode(ARM::t2LDRSHpci);
3358       break;
3359     case ARM::t2LDRSBs:
3360       Inst.setOpcode(ARM::t2LDRSBpci);
3361       break;
3362     case ARM::t2LDRs:
3363       Inst.setOpcode(ARM::t2LDRpci);
3364       break;
3365     case ARM::t2PLDs:
3366       Inst.setOpcode(ARM::t2PLDpci);
3367       break;
3368     case ARM::t2PLIs:
3369       Inst.setOpcode(ARM::t2PLIpci);
3370       break;
3371     default:
3372       return MCDisassembler::Fail;
3373     }
3374 
3375     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3376   }
3377 
3378   if (Rt == 15) {
3379     switch (Inst.getOpcode()) {
3380     case ARM::t2LDRSHs:
3381       return MCDisassembler::Fail;
3382     case ARM::t2LDRHs:
3383       Inst.setOpcode(ARM::t2PLDWs);
3384       break;
3385     case ARM::t2LDRSBs:
3386       Inst.setOpcode(ARM::t2PLIs);
3387     default:
3388       break;
3389     }
3390   }
3391 
3392   switch (Inst.getOpcode()) {
3393     case ARM::t2PLDs:
3394       break;
3395     case ARM::t2PLIs:
3396       if (!hasV7Ops)
3397         return MCDisassembler::Fail;
3398       break;
3399     case ARM::t2PLDWs:
3400       if (!hasV7Ops || !hasMP)
3401         return MCDisassembler::Fail;
3402       break;
3403     default:
3404       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3405         return MCDisassembler::Fail;
3406   }
3407 
3408   unsigned addrmode = fieldFromInstruction(Insn, 4, 2);
3409   addrmode |= fieldFromInstruction(Insn, 0, 4) << 2;
3410   addrmode |= fieldFromInstruction(Insn, 16, 4) << 6;
3411   if (!Check(S, DecodeT2AddrModeSOReg(Inst, addrmode, Address, Decoder)))
3412     return MCDisassembler::Fail;
3413 
3414   return S;
3415 }
3416 
3417 static DecodeStatus DecodeT2LoadImm8(MCInst &Inst, unsigned Insn,
3418                                 uint64_t Address, const void* Decoder) {
3419   DecodeStatus S = MCDisassembler::Success;
3420 
3421   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3422   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3423   unsigned U = fieldFromInstruction(Insn, 9, 1);
3424   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3425   imm |= (U << 8);
3426   imm |= (Rn << 9);
3427   unsigned add = fieldFromInstruction(Insn, 9, 1);
3428 
3429   const FeatureBitset &featureBits =
3430     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3431 
3432   bool hasMP = featureBits[ARM::FeatureMP];
3433   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3434 
3435   if (Rn == 15) {
3436     switch (Inst.getOpcode()) {
3437     case ARM::t2LDRi8:
3438       Inst.setOpcode(ARM::t2LDRpci);
3439       break;
3440     case ARM::t2LDRBi8:
3441       Inst.setOpcode(ARM::t2LDRBpci);
3442       break;
3443     case ARM::t2LDRSBi8:
3444       Inst.setOpcode(ARM::t2LDRSBpci);
3445       break;
3446     case ARM::t2LDRHi8:
3447       Inst.setOpcode(ARM::t2LDRHpci);
3448       break;
3449     case ARM::t2LDRSHi8:
3450       Inst.setOpcode(ARM::t2LDRSHpci);
3451       break;
3452     case ARM::t2PLDi8:
3453       Inst.setOpcode(ARM::t2PLDpci);
3454       break;
3455     case ARM::t2PLIi8:
3456       Inst.setOpcode(ARM::t2PLIpci);
3457       break;
3458     default:
3459       return MCDisassembler::Fail;
3460     }
3461     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3462   }
3463 
3464   if (Rt == 15) {
3465     switch (Inst.getOpcode()) {
3466     case ARM::t2LDRSHi8:
3467       return MCDisassembler::Fail;
3468     case ARM::t2LDRHi8:
3469       if (!add)
3470         Inst.setOpcode(ARM::t2PLDWi8);
3471       break;
3472     case ARM::t2LDRSBi8:
3473       Inst.setOpcode(ARM::t2PLIi8);
3474       break;
3475     default:
3476       break;
3477     }
3478   }
3479 
3480   switch (Inst.getOpcode()) {
3481   case ARM::t2PLDi8:
3482     break;
3483   case ARM::t2PLIi8:
3484     if (!hasV7Ops)
3485       return MCDisassembler::Fail;
3486     break;
3487   case ARM::t2PLDWi8:
3488       if (!hasV7Ops || !hasMP)
3489         return MCDisassembler::Fail;
3490       break;
3491   default:
3492     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3493       return MCDisassembler::Fail;
3494   }
3495 
3496   if (!Check(S, DecodeT2AddrModeImm8(Inst, imm, Address, Decoder)))
3497     return MCDisassembler::Fail;
3498   return S;
3499 }
3500 
3501 static DecodeStatus DecodeT2LoadImm12(MCInst &Inst, unsigned Insn,
3502                                 uint64_t Address, const void* Decoder) {
3503   DecodeStatus S = MCDisassembler::Success;
3504 
3505   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3506   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3507   unsigned imm = fieldFromInstruction(Insn, 0, 12);
3508   imm |= (Rn << 13);
3509 
3510   const FeatureBitset &featureBits =
3511     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3512 
3513   bool hasMP = featureBits[ARM::FeatureMP];
3514   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3515 
3516   if (Rn == 15) {
3517     switch (Inst.getOpcode()) {
3518     case ARM::t2LDRi12:
3519       Inst.setOpcode(ARM::t2LDRpci);
3520       break;
3521     case ARM::t2LDRHi12:
3522       Inst.setOpcode(ARM::t2LDRHpci);
3523       break;
3524     case ARM::t2LDRSHi12:
3525       Inst.setOpcode(ARM::t2LDRSHpci);
3526       break;
3527     case ARM::t2LDRBi12:
3528       Inst.setOpcode(ARM::t2LDRBpci);
3529       break;
3530     case ARM::t2LDRSBi12:
3531       Inst.setOpcode(ARM::t2LDRSBpci);
3532       break;
3533     case ARM::t2PLDi12:
3534       Inst.setOpcode(ARM::t2PLDpci);
3535       break;
3536     case ARM::t2PLIi12:
3537       Inst.setOpcode(ARM::t2PLIpci);
3538       break;
3539     default:
3540       return MCDisassembler::Fail;
3541     }
3542     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3543   }
3544 
3545   if (Rt == 15) {
3546     switch (Inst.getOpcode()) {
3547     case ARM::t2LDRSHi12:
3548       return MCDisassembler::Fail;
3549     case ARM::t2LDRHi12:
3550       Inst.setOpcode(ARM::t2PLDWi12);
3551       break;
3552     case ARM::t2LDRSBi12:
3553       Inst.setOpcode(ARM::t2PLIi12);
3554       break;
3555     default:
3556       break;
3557     }
3558   }
3559 
3560   switch (Inst.getOpcode()) {
3561   case ARM::t2PLDi12:
3562     break;
3563   case ARM::t2PLIi12:
3564     if (!hasV7Ops)
3565       return MCDisassembler::Fail;
3566     break;
3567   case ARM::t2PLDWi12:
3568       if (!hasV7Ops || !hasMP)
3569         return MCDisassembler::Fail;
3570       break;
3571   default:
3572     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3573       return MCDisassembler::Fail;
3574   }
3575 
3576   if (!Check(S, DecodeT2AddrModeImm12(Inst, imm, Address, Decoder)))
3577     return MCDisassembler::Fail;
3578   return S;
3579 }
3580 
3581 static DecodeStatus DecodeT2LoadT(MCInst &Inst, unsigned Insn,
3582                                 uint64_t Address, const void* Decoder) {
3583   DecodeStatus S = MCDisassembler::Success;
3584 
3585   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3586   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3587   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3588   imm |= (Rn << 9);
3589 
3590   if (Rn == 15) {
3591     switch (Inst.getOpcode()) {
3592     case ARM::t2LDRT:
3593       Inst.setOpcode(ARM::t2LDRpci);
3594       break;
3595     case ARM::t2LDRBT:
3596       Inst.setOpcode(ARM::t2LDRBpci);
3597       break;
3598     case ARM::t2LDRHT:
3599       Inst.setOpcode(ARM::t2LDRHpci);
3600       break;
3601     case ARM::t2LDRSBT:
3602       Inst.setOpcode(ARM::t2LDRSBpci);
3603       break;
3604     case ARM::t2LDRSHT:
3605       Inst.setOpcode(ARM::t2LDRSHpci);
3606       break;
3607     default:
3608       return MCDisassembler::Fail;
3609     }
3610     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3611   }
3612 
3613   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
3614     return MCDisassembler::Fail;
3615   if (!Check(S, DecodeT2AddrModeImm8(Inst, imm, Address, Decoder)))
3616     return MCDisassembler::Fail;
3617   return S;
3618 }
3619 
3620 static DecodeStatus DecodeT2LoadLabel(MCInst &Inst, unsigned Insn,
3621                                 uint64_t Address, const void* Decoder) {
3622   DecodeStatus S = MCDisassembler::Success;
3623 
3624   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3625   unsigned U = fieldFromInstruction(Insn, 23, 1);
3626   int imm = fieldFromInstruction(Insn, 0, 12);
3627 
3628   const FeatureBitset &featureBits =
3629     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3630 
3631   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3632 
3633   if (Rt == 15) {
3634     switch (Inst.getOpcode()) {
3635       case ARM::t2LDRBpci:
3636       case ARM::t2LDRHpci:
3637         Inst.setOpcode(ARM::t2PLDpci);
3638         break;
3639       case ARM::t2LDRSBpci:
3640         Inst.setOpcode(ARM::t2PLIpci);
3641         break;
3642       case ARM::t2LDRSHpci:
3643         return MCDisassembler::Fail;
3644       default:
3645         break;
3646     }
3647   }
3648 
3649   switch(Inst.getOpcode()) {
3650   case ARM::t2PLDpci:
3651     break;
3652   case ARM::t2PLIpci:
3653     if (!hasV7Ops)
3654       return MCDisassembler::Fail;
3655     break;
3656   default:
3657     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3658       return MCDisassembler::Fail;
3659   }
3660 
3661   if (!U) {
3662     // Special case for #-0.
3663     if (imm == 0)
3664       imm = INT32_MIN;
3665     else
3666       imm = -imm;
3667   }
3668   Inst.addOperand(MCOperand::createImm(imm));
3669 
3670   return S;
3671 }
3672 
3673 static DecodeStatus DecodeT2Imm8S4(MCInst &Inst, unsigned Val,
3674                            uint64_t Address, const void *Decoder) {
3675   if (Val == 0)
3676     Inst.addOperand(MCOperand::createImm(INT32_MIN));
3677   else {
3678     int imm = Val & 0xFF;
3679 
3680     if (!(Val & 0x100)) imm *= -1;
3681     Inst.addOperand(MCOperand::createImm(imm * 4));
3682   }
3683 
3684   return MCDisassembler::Success;
3685 }
3686 
3687 static DecodeStatus DecodeT2AddrModeImm8s4(MCInst &Inst, unsigned Val,
3688                                    uint64_t Address, const void *Decoder) {
3689   DecodeStatus S = MCDisassembler::Success;
3690 
3691   unsigned Rn = fieldFromInstruction(Val, 9, 4);
3692   unsigned imm = fieldFromInstruction(Val, 0, 9);
3693 
3694   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3695     return MCDisassembler::Fail;
3696   if (!Check(S, DecodeT2Imm8S4(Inst, imm, Address, Decoder)))
3697     return MCDisassembler::Fail;
3698 
3699   return S;
3700 }
3701 
3702 static DecodeStatus DecodeT2AddrModeImm0_1020s4(MCInst &Inst,unsigned Val,
3703                                    uint64_t Address, const void *Decoder) {
3704   DecodeStatus S = MCDisassembler::Success;
3705 
3706   unsigned Rn = fieldFromInstruction(Val, 8, 4);
3707   unsigned imm = fieldFromInstruction(Val, 0, 8);
3708 
3709   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
3710     return MCDisassembler::Fail;
3711 
3712   Inst.addOperand(MCOperand::createImm(imm));
3713 
3714   return S;
3715 }
3716 
3717 static DecodeStatus DecodeT2Imm8(MCInst &Inst, unsigned Val,
3718                          uint64_t Address, const void *Decoder) {
3719   int imm = Val & 0xFF;
3720   if (Val == 0)
3721     imm = INT32_MIN;
3722   else if (!(Val & 0x100))
3723     imm *= -1;
3724   Inst.addOperand(MCOperand::createImm(imm));
3725 
3726   return MCDisassembler::Success;
3727 }
3728 
3729 static DecodeStatus DecodeT2AddrModeImm8(MCInst &Inst, unsigned Val,
3730                                  uint64_t Address, const void *Decoder) {
3731   DecodeStatus S = MCDisassembler::Success;
3732 
3733   unsigned Rn = fieldFromInstruction(Val, 9, 4);
3734   unsigned imm = fieldFromInstruction(Val, 0, 9);
3735 
3736   // Thumb stores cannot use PC as dest register.
3737   switch (Inst.getOpcode()) {
3738   case ARM::t2STRT:
3739   case ARM::t2STRBT:
3740   case ARM::t2STRHT:
3741   case ARM::t2STRi8:
3742   case ARM::t2STRHi8:
3743   case ARM::t2STRBi8:
3744     if (Rn == 15)
3745       return MCDisassembler::Fail;
3746     break;
3747   default:
3748     break;
3749   }
3750 
3751   // Some instructions always use an additive offset.
3752   switch (Inst.getOpcode()) {
3753     case ARM::t2LDRT:
3754     case ARM::t2LDRBT:
3755     case ARM::t2LDRHT:
3756     case ARM::t2LDRSBT:
3757     case ARM::t2LDRSHT:
3758     case ARM::t2STRT:
3759     case ARM::t2STRBT:
3760     case ARM::t2STRHT:
3761       imm |= 0x100;
3762       break;
3763     default:
3764       break;
3765   }
3766 
3767   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3768     return MCDisassembler::Fail;
3769   if (!Check(S, DecodeT2Imm8(Inst, imm, Address, Decoder)))
3770     return MCDisassembler::Fail;
3771 
3772   return S;
3773 }
3774 
3775 static DecodeStatus DecodeT2LdStPre(MCInst &Inst, unsigned Insn,
3776                                     uint64_t Address, const void *Decoder) {
3777   DecodeStatus S = MCDisassembler::Success;
3778 
3779   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3780   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3781   unsigned addr = fieldFromInstruction(Insn, 0, 8);
3782   addr |= fieldFromInstruction(Insn, 9, 1) << 8;
3783   addr |= Rn << 9;
3784   unsigned load = fieldFromInstruction(Insn, 20, 1);
3785 
3786   if (Rn == 15) {
3787     switch (Inst.getOpcode()) {
3788     case ARM::t2LDR_PRE:
3789     case ARM::t2LDR_POST:
3790       Inst.setOpcode(ARM::t2LDRpci);
3791       break;
3792     case ARM::t2LDRB_PRE:
3793     case ARM::t2LDRB_POST:
3794       Inst.setOpcode(ARM::t2LDRBpci);
3795       break;
3796     case ARM::t2LDRH_PRE:
3797     case ARM::t2LDRH_POST:
3798       Inst.setOpcode(ARM::t2LDRHpci);
3799       break;
3800     case ARM::t2LDRSB_PRE:
3801     case ARM::t2LDRSB_POST:
3802       if (Rt == 15)
3803         Inst.setOpcode(ARM::t2PLIpci);
3804       else
3805         Inst.setOpcode(ARM::t2LDRSBpci);
3806       break;
3807     case ARM::t2LDRSH_PRE:
3808     case ARM::t2LDRSH_POST:
3809       Inst.setOpcode(ARM::t2LDRSHpci);
3810       break;
3811     default:
3812       return MCDisassembler::Fail;
3813     }
3814     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3815   }
3816 
3817   if (!load) {
3818     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3819       return MCDisassembler::Fail;
3820   }
3821 
3822   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3823     return MCDisassembler::Fail;
3824 
3825   if (load) {
3826     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3827       return MCDisassembler::Fail;
3828   }
3829 
3830   if (!Check(S, DecodeT2AddrModeImm8(Inst, addr, Address, Decoder)))
3831     return MCDisassembler::Fail;
3832 
3833   return S;
3834 }
3835 
3836 static DecodeStatus DecodeT2AddrModeImm12(MCInst &Inst, unsigned Val,
3837                                   uint64_t Address, const void *Decoder) {
3838   DecodeStatus S = MCDisassembler::Success;
3839 
3840   unsigned Rn = fieldFromInstruction(Val, 13, 4);
3841   unsigned imm = fieldFromInstruction(Val, 0, 12);
3842 
3843   // Thumb stores cannot use PC as dest register.
3844   switch (Inst.getOpcode()) {
3845   case ARM::t2STRi12:
3846   case ARM::t2STRBi12:
3847   case ARM::t2STRHi12:
3848     if (Rn == 15)
3849       return MCDisassembler::Fail;
3850   default:
3851     break;
3852   }
3853 
3854   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3855     return MCDisassembler::Fail;
3856   Inst.addOperand(MCOperand::createImm(imm));
3857 
3858   return S;
3859 }
3860 
3861 
3862 static DecodeStatus DecodeThumbAddSPImm(MCInst &Inst, uint16_t Insn,
3863                                 uint64_t Address, const void *Decoder) {
3864   unsigned imm = fieldFromInstruction(Insn, 0, 7);
3865 
3866   Inst.addOperand(MCOperand::createReg(ARM::SP));
3867   Inst.addOperand(MCOperand::createReg(ARM::SP));
3868   Inst.addOperand(MCOperand::createImm(imm));
3869 
3870   return MCDisassembler::Success;
3871 }
3872 
3873 static DecodeStatus DecodeThumbAddSPReg(MCInst &Inst, uint16_t Insn,
3874                                 uint64_t Address, const void *Decoder) {
3875   DecodeStatus S = MCDisassembler::Success;
3876 
3877   if (Inst.getOpcode() == ARM::tADDrSP) {
3878     unsigned Rdm = fieldFromInstruction(Insn, 0, 3);
3879     Rdm |= fieldFromInstruction(Insn, 7, 1) << 3;
3880 
3881     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
3882     return MCDisassembler::Fail;
3883     Inst.addOperand(MCOperand::createReg(ARM::SP));
3884     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
3885     return MCDisassembler::Fail;
3886   } else if (Inst.getOpcode() == ARM::tADDspr) {
3887     unsigned Rm = fieldFromInstruction(Insn, 3, 4);
3888 
3889     Inst.addOperand(MCOperand::createReg(ARM::SP));
3890     Inst.addOperand(MCOperand::createReg(ARM::SP));
3891     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3892     return MCDisassembler::Fail;
3893   }
3894 
3895   return S;
3896 }
3897 
3898 static DecodeStatus DecodeThumbCPS(MCInst &Inst, uint16_t Insn,
3899                            uint64_t Address, const void *Decoder) {
3900   unsigned imod = fieldFromInstruction(Insn, 4, 1) | 0x2;
3901   unsigned flags = fieldFromInstruction(Insn, 0, 3);
3902 
3903   Inst.addOperand(MCOperand::createImm(imod));
3904   Inst.addOperand(MCOperand::createImm(flags));
3905 
3906   return MCDisassembler::Success;
3907 }
3908 
3909 static DecodeStatus DecodePostIdxReg(MCInst &Inst, unsigned Insn,
3910                              uint64_t Address, const void *Decoder) {
3911   DecodeStatus S = MCDisassembler::Success;
3912   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3913   unsigned add = fieldFromInstruction(Insn, 4, 1);
3914 
3915   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
3916     return MCDisassembler::Fail;
3917   Inst.addOperand(MCOperand::createImm(add));
3918 
3919   return S;
3920 }
3921 
3922 static DecodeStatus DecodeThumbBLXOffset(MCInst &Inst, unsigned Val,
3923                                  uint64_t Address, const void *Decoder) {
3924   // Val is passed in as S:J1:J2:imm10H:imm10L:'0'
3925   // Note only one trailing zero not two.  Also the J1 and J2 values are from
3926   // the encoded instruction.  So here change to I1 and I2 values via:
3927   // I1 = NOT(J1 EOR S);
3928   // I2 = NOT(J2 EOR S);
3929   // and build the imm32 with two trailing zeros as documented:
3930   // imm32 = SignExtend(S:I1:I2:imm10H:imm10L:'00', 32);
3931   unsigned S = (Val >> 23) & 1;
3932   unsigned J1 = (Val >> 22) & 1;
3933   unsigned J2 = (Val >> 21) & 1;
3934   unsigned I1 = !(J1 ^ S);
3935   unsigned I2 = !(J2 ^ S);
3936   unsigned tmp = (Val & ~0x600000) | (I1 << 22) | (I2 << 21);
3937   int imm32 = SignExtend32<25>(tmp << 1);
3938 
3939   if (!tryAddingSymbolicOperand(Address,
3940                                 (Address & ~2u) + imm32 + 4,
3941                                 true, 4, Inst, Decoder))
3942     Inst.addOperand(MCOperand::createImm(imm32));
3943   return MCDisassembler::Success;
3944 }
3945 
3946 static DecodeStatus DecodeCoprocessor(MCInst &Inst, unsigned Val,
3947                               uint64_t Address, const void *Decoder) {
3948   if (Val == 0xA || Val == 0xB)
3949     return MCDisassembler::Fail;
3950 
3951   const FeatureBitset &featureBits =
3952     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3953 
3954   if (featureBits[ARM::HasV8Ops] && !(Val == 14 || Val == 15))
3955     return MCDisassembler::Fail;
3956 
3957   Inst.addOperand(MCOperand::createImm(Val));
3958   return MCDisassembler::Success;
3959 }
3960 
3961 static DecodeStatus
3962 DecodeThumbTableBranch(MCInst &Inst, unsigned Insn,
3963                        uint64_t Address, const void *Decoder) {
3964   DecodeStatus S = MCDisassembler::Success;
3965 
3966   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3967   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3968 
3969   if (Rn == ARM::SP) S = MCDisassembler::SoftFail;
3970   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3971     return MCDisassembler::Fail;
3972   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
3973     return MCDisassembler::Fail;
3974   return S;
3975 }
3976 
3977 static DecodeStatus
3978 DecodeThumb2BCCInstruction(MCInst &Inst, unsigned Insn,
3979                            uint64_t Address, const void *Decoder) {
3980   DecodeStatus S = MCDisassembler::Success;
3981 
3982   unsigned pred = fieldFromInstruction(Insn, 22, 4);
3983   if (pred == 0xE || pred == 0xF) {
3984     unsigned opc = fieldFromInstruction(Insn, 4, 28);
3985     switch (opc) {
3986       default:
3987         return MCDisassembler::Fail;
3988       case 0xf3bf8f4:
3989         Inst.setOpcode(ARM::t2DSB);
3990         break;
3991       case 0xf3bf8f5:
3992         Inst.setOpcode(ARM::t2DMB);
3993         break;
3994       case 0xf3bf8f6:
3995         Inst.setOpcode(ARM::t2ISB);
3996         break;
3997     }
3998 
3999     unsigned imm = fieldFromInstruction(Insn, 0, 4);
4000     return DecodeMemBarrierOption(Inst, imm, Address, Decoder);
4001   }
4002 
4003   unsigned brtarget = fieldFromInstruction(Insn, 0, 11) << 1;
4004   brtarget |= fieldFromInstruction(Insn, 11, 1) << 19;
4005   brtarget |= fieldFromInstruction(Insn, 13, 1) << 18;
4006   brtarget |= fieldFromInstruction(Insn, 16, 6) << 12;
4007   brtarget |= fieldFromInstruction(Insn, 26, 1) << 20;
4008 
4009   if (!Check(S, DecodeT2BROperand(Inst, brtarget, Address, Decoder)))
4010     return MCDisassembler::Fail;
4011   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4012     return MCDisassembler::Fail;
4013 
4014   return S;
4015 }
4016 
4017 // Decode a shifted immediate operand.  These basically consist
4018 // of an 8-bit value, and a 4-bit directive that specifies either
4019 // a splat operation or a rotation.
4020 static DecodeStatus DecodeT2SOImm(MCInst &Inst, unsigned Val,
4021                           uint64_t Address, const void *Decoder) {
4022   unsigned ctrl = fieldFromInstruction(Val, 10, 2);
4023   if (ctrl == 0) {
4024     unsigned byte = fieldFromInstruction(Val, 8, 2);
4025     unsigned imm = fieldFromInstruction(Val, 0, 8);
4026     switch (byte) {
4027       case 0:
4028         Inst.addOperand(MCOperand::createImm(imm));
4029         break;
4030       case 1:
4031         Inst.addOperand(MCOperand::createImm((imm << 16) | imm));
4032         break;
4033       case 2:
4034         Inst.addOperand(MCOperand::createImm((imm << 24) | (imm << 8)));
4035         break;
4036       case 3:
4037         Inst.addOperand(MCOperand::createImm((imm << 24) | (imm << 16) |
4038                                              (imm << 8)  |  imm));
4039         break;
4040     }
4041   } else {
4042     unsigned unrot = fieldFromInstruction(Val, 0, 7) | 0x80;
4043     unsigned rot = fieldFromInstruction(Val, 7, 5);
4044     unsigned imm = (unrot >> rot) | (unrot << ((32-rot)&31));
4045     Inst.addOperand(MCOperand::createImm(imm));
4046   }
4047 
4048   return MCDisassembler::Success;
4049 }
4050 
4051 static DecodeStatus
4052 DecodeThumbBCCTargetOperand(MCInst &Inst, unsigned Val,
4053                             uint64_t Address, const void *Decoder) {
4054   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<9>(Val<<1) + 4,
4055                                 true, 2, Inst, Decoder))
4056     Inst.addOperand(MCOperand::createImm(SignExtend32<9>(Val << 1)));
4057   return MCDisassembler::Success;
4058 }
4059 
4060 static DecodeStatus DecodeThumbBLTargetOperand(MCInst &Inst, unsigned Val,
4061                                                uint64_t Address,
4062                                                const void *Decoder) {
4063   // Val is passed in as S:J1:J2:imm10:imm11
4064   // Note no trailing zero after imm11.  Also the J1 and J2 values are from
4065   // the encoded instruction.  So here change to I1 and I2 values via:
4066   // I1 = NOT(J1 EOR S);
4067   // I2 = NOT(J2 EOR S);
4068   // and build the imm32 with one trailing zero as documented:
4069   // imm32 = SignExtend(S:I1:I2:imm10:imm11:'0', 32);
4070   unsigned S = (Val >> 23) & 1;
4071   unsigned J1 = (Val >> 22) & 1;
4072   unsigned J2 = (Val >> 21) & 1;
4073   unsigned I1 = !(J1 ^ S);
4074   unsigned I2 = !(J2 ^ S);
4075   unsigned tmp = (Val & ~0x600000) | (I1 << 22) | (I2 << 21);
4076   int imm32 = SignExtend32<25>(tmp << 1);
4077 
4078   if (!tryAddingSymbolicOperand(Address, Address + imm32 + 4,
4079                                 true, 4, Inst, Decoder))
4080     Inst.addOperand(MCOperand::createImm(imm32));
4081   return MCDisassembler::Success;
4082 }
4083 
4084 static DecodeStatus DecodeMemBarrierOption(MCInst &Inst, unsigned Val,
4085                                    uint64_t Address, const void *Decoder) {
4086   if (Val & ~0xf)
4087     return MCDisassembler::Fail;
4088 
4089   Inst.addOperand(MCOperand::createImm(Val));
4090   return MCDisassembler::Success;
4091 }
4092 
4093 static DecodeStatus DecodeInstSyncBarrierOption(MCInst &Inst, unsigned Val,
4094                                         uint64_t Address, const void *Decoder) {
4095   if (Val & ~0xf)
4096     return MCDisassembler::Fail;
4097 
4098   Inst.addOperand(MCOperand::createImm(Val));
4099   return MCDisassembler::Success;
4100 }
4101 
4102 static DecodeStatus DecodeMSRMask(MCInst &Inst, unsigned Val,
4103                           uint64_t Address, const void *Decoder) {
4104   DecodeStatus S = MCDisassembler::Success;
4105   const FeatureBitset &FeatureBits =
4106     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4107 
4108   if (FeatureBits[ARM::FeatureMClass]) {
4109     unsigned ValLow = Val & 0xff;
4110 
4111     // Validate the SYSm value first.
4112     switch (ValLow) {
4113     case  0: // apsr
4114     case  1: // iapsr
4115     case  2: // eapsr
4116     case  3: // xpsr
4117     case  5: // ipsr
4118     case  6: // epsr
4119     case  7: // iepsr
4120     case  8: // msp
4121     case  9: // psp
4122     case 16: // primask
4123     case 20: // control
4124       break;
4125     case 17: // basepri
4126     case 18: // basepri_max
4127     case 19: // faultmask
4128       if (!(FeatureBits[ARM::HasV7Ops]))
4129         // Values basepri, basepri_max and faultmask are only valid for v7m.
4130         return MCDisassembler::Fail;
4131       break;
4132     case 0x8a: // msplim_ns
4133     case 0x8b: // psplim_ns
4134     case 0x91: // basepri_ns
4135     case 0x92: // basepri_max_ns
4136     case 0x93: // faultmask_ns
4137       if (!(FeatureBits[ARM::HasV8MMainlineOps]))
4138         return MCDisassembler::Fail;
4139       LLVM_FALLTHROUGH;
4140     case 10:   // msplim
4141     case 11:   // psplim
4142     case 0x88: // msp_ns
4143     case 0x89: // psp_ns
4144     case 0x90: // primask_ns
4145     case 0x94: // control_ns
4146     case 0x98: // sp_ns
4147       if (!(FeatureBits[ARM::Feature8MSecExt]))
4148         return MCDisassembler::Fail;
4149       break;
4150     default:
4151       return MCDisassembler::Fail;
4152     }
4153 
4154     if (Inst.getOpcode() == ARM::t2MSR_M) {
4155       unsigned Mask = fieldFromInstruction(Val, 10, 2);
4156       if (!(FeatureBits[ARM::HasV7Ops])) {
4157         // The ARMv6-M MSR bits {11-10} can be only 0b10, other values are
4158         // unpredictable.
4159         if (Mask != 2)
4160           S = MCDisassembler::SoftFail;
4161       }
4162       else {
4163         // The ARMv7-M architecture stores an additional 2-bit mask value in
4164         // MSR bits {11-10}. The mask is used only with apsr, iapsr, eapsr and
4165         // xpsr, it has to be 0b10 in other cases. Bit mask{1} indicates if
4166         // the NZCVQ bits should be moved by the instruction. Bit mask{0}
4167         // indicates the move for the GE{3:0} bits, the mask{0} bit can be set
4168         // only if the processor includes the DSP extension.
4169         if (Mask == 0 || (Mask != 2 && ValLow > 3) ||
4170             (!(FeatureBits[ARM::FeatureDSP]) && (Mask & 1)))
4171           S = MCDisassembler::SoftFail;
4172       }
4173     }
4174   } else {
4175     // A/R class
4176     if (Val == 0)
4177       return MCDisassembler::Fail;
4178   }
4179   Inst.addOperand(MCOperand::createImm(Val));
4180   return S;
4181 }
4182 
4183 static DecodeStatus DecodeBankedReg(MCInst &Inst, unsigned Val,
4184                                     uint64_t Address, const void *Decoder) {
4185 
4186   unsigned R = fieldFromInstruction(Val, 5, 1);
4187   unsigned SysM = fieldFromInstruction(Val, 0, 5);
4188 
4189   // The table of encodings for these banked registers comes from B9.2.3 of the
4190   // ARM ARM. There are patterns, but nothing regular enough to make this logic
4191   // neater. So by fiat, these values are UNPREDICTABLE:
4192   if (!R) {
4193     if (SysM == 0x7 || SysM == 0xf || SysM == 0x18 || SysM == 0x19 ||
4194         SysM == 0x1a || SysM == 0x1b)
4195       return MCDisassembler::SoftFail;
4196   } else {
4197     if (SysM != 0xe && SysM != 0x10 && SysM != 0x12 && SysM != 0x14 &&
4198         SysM != 0x16 && SysM != 0x1c && SysM != 0x1e)
4199       return MCDisassembler::SoftFail;
4200   }
4201 
4202   Inst.addOperand(MCOperand::createImm(Val));
4203   return MCDisassembler::Success;
4204 }
4205 
4206 static DecodeStatus DecodeDoubleRegLoad(MCInst &Inst, unsigned Insn,
4207                                         uint64_t Address, const void *Decoder) {
4208   DecodeStatus S = MCDisassembler::Success;
4209 
4210   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4211   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4212   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4213 
4214   if (Rn == 0xF)
4215     S = MCDisassembler::SoftFail;
4216 
4217   if (!Check(S, DecodeGPRPairRegisterClass(Inst, Rt, Address, Decoder)))
4218     return MCDisassembler::Fail;
4219   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4220     return MCDisassembler::Fail;
4221   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4222     return MCDisassembler::Fail;
4223 
4224   return S;
4225 }
4226 
4227 static DecodeStatus DecodeDoubleRegStore(MCInst &Inst, unsigned Insn,
4228                                          uint64_t Address,
4229                                          const void *Decoder) {
4230   DecodeStatus S = MCDisassembler::Success;
4231 
4232   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4233   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
4234   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4235   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4236 
4237   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
4238     return MCDisassembler::Fail;
4239 
4240   if (Rn == 0xF || Rd == Rn || Rd == Rt || Rd == Rt+1)
4241     S = MCDisassembler::SoftFail;
4242 
4243   if (!Check(S, DecodeGPRPairRegisterClass(Inst, Rt, Address, Decoder)))
4244     return MCDisassembler::Fail;
4245   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4246     return MCDisassembler::Fail;
4247   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4248     return MCDisassembler::Fail;
4249 
4250   return S;
4251 }
4252 
4253 static DecodeStatus DecodeLDRPreImm(MCInst &Inst, unsigned Insn,
4254                             uint64_t Address, const void *Decoder) {
4255   DecodeStatus S = MCDisassembler::Success;
4256 
4257   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4258   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4259   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4260   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4261   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4262   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4263 
4264   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4265 
4266   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4267     return MCDisassembler::Fail;
4268   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4269     return MCDisassembler::Fail;
4270   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
4271     return MCDisassembler::Fail;
4272   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4273     return MCDisassembler::Fail;
4274 
4275   return S;
4276 }
4277 
4278 static DecodeStatus DecodeLDRPreReg(MCInst &Inst, unsigned Insn,
4279                             uint64_t Address, const void *Decoder) {
4280   DecodeStatus S = MCDisassembler::Success;
4281 
4282   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4283   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4284   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4285   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4286   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4287   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4288   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4289 
4290   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4291   if (Rm == 0xF) S = MCDisassembler::SoftFail;
4292 
4293   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4294     return MCDisassembler::Fail;
4295   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4296     return MCDisassembler::Fail;
4297   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
4298     return MCDisassembler::Fail;
4299   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4300     return MCDisassembler::Fail;
4301 
4302   return S;
4303 }
4304 
4305 static DecodeStatus DecodeSTRPreImm(MCInst &Inst, unsigned Insn,
4306                             uint64_t Address, const void *Decoder) {
4307   DecodeStatus S = MCDisassembler::Success;
4308 
4309   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4310   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4311   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4312   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4313   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4314   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4315 
4316   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4317 
4318   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4319     return MCDisassembler::Fail;
4320   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4321     return MCDisassembler::Fail;
4322   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
4323     return MCDisassembler::Fail;
4324   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4325     return MCDisassembler::Fail;
4326 
4327   return S;
4328 }
4329 
4330 static DecodeStatus DecodeSTRPreReg(MCInst &Inst, unsigned Insn,
4331                             uint64_t Address, const void *Decoder) {
4332   DecodeStatus S = MCDisassembler::Success;
4333 
4334   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4335   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4336   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4337   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4338   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4339   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4340 
4341   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4342 
4343   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4344     return MCDisassembler::Fail;
4345   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4346     return MCDisassembler::Fail;
4347   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
4348     return MCDisassembler::Fail;
4349   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4350     return MCDisassembler::Fail;
4351 
4352   return S;
4353 }
4354 
4355 static DecodeStatus DecodeVLD1LN(MCInst &Inst, unsigned Insn,
4356                          uint64_t Address, const void *Decoder) {
4357   DecodeStatus S = MCDisassembler::Success;
4358 
4359   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4360   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4361   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4362   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4363   unsigned size = fieldFromInstruction(Insn, 10, 2);
4364 
4365   unsigned align = 0;
4366   unsigned index = 0;
4367   switch (size) {
4368     default:
4369       return MCDisassembler::Fail;
4370     case 0:
4371       if (fieldFromInstruction(Insn, 4, 1))
4372         return MCDisassembler::Fail; // UNDEFINED
4373       index = fieldFromInstruction(Insn, 5, 3);
4374       break;
4375     case 1:
4376       if (fieldFromInstruction(Insn, 5, 1))
4377         return MCDisassembler::Fail; // UNDEFINED
4378       index = fieldFromInstruction(Insn, 6, 2);
4379       if (fieldFromInstruction(Insn, 4, 1))
4380         align = 2;
4381       break;
4382     case 2:
4383       if (fieldFromInstruction(Insn, 6, 1))
4384         return MCDisassembler::Fail; // UNDEFINED
4385       index = fieldFromInstruction(Insn, 7, 1);
4386 
4387       switch (fieldFromInstruction(Insn, 4, 2)) {
4388         case 0 :
4389           align = 0; break;
4390         case 3:
4391           align = 4; break;
4392         default:
4393           return MCDisassembler::Fail;
4394       }
4395       break;
4396   }
4397 
4398   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4399     return MCDisassembler::Fail;
4400   if (Rm != 0xF) { // Writeback
4401     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4402       return MCDisassembler::Fail;
4403   }
4404   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4405     return MCDisassembler::Fail;
4406   Inst.addOperand(MCOperand::createImm(align));
4407   if (Rm != 0xF) {
4408     if (Rm != 0xD) {
4409       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4410         return MCDisassembler::Fail;
4411     } else
4412       Inst.addOperand(MCOperand::createReg(0));
4413   }
4414 
4415   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4416     return MCDisassembler::Fail;
4417   Inst.addOperand(MCOperand::createImm(index));
4418 
4419   return S;
4420 }
4421 
4422 static DecodeStatus DecodeVST1LN(MCInst &Inst, unsigned Insn,
4423                          uint64_t Address, const void *Decoder) {
4424   DecodeStatus S = MCDisassembler::Success;
4425 
4426   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4427   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4428   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4429   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4430   unsigned size = fieldFromInstruction(Insn, 10, 2);
4431 
4432   unsigned align = 0;
4433   unsigned index = 0;
4434   switch (size) {
4435     default:
4436       return MCDisassembler::Fail;
4437     case 0:
4438       if (fieldFromInstruction(Insn, 4, 1))
4439         return MCDisassembler::Fail; // UNDEFINED
4440       index = fieldFromInstruction(Insn, 5, 3);
4441       break;
4442     case 1:
4443       if (fieldFromInstruction(Insn, 5, 1))
4444         return MCDisassembler::Fail; // UNDEFINED
4445       index = fieldFromInstruction(Insn, 6, 2);
4446       if (fieldFromInstruction(Insn, 4, 1))
4447         align = 2;
4448       break;
4449     case 2:
4450       if (fieldFromInstruction(Insn, 6, 1))
4451         return MCDisassembler::Fail; // UNDEFINED
4452       index = fieldFromInstruction(Insn, 7, 1);
4453 
4454       switch (fieldFromInstruction(Insn, 4, 2)) {
4455         case 0:
4456           align = 0; break;
4457         case 3:
4458           align = 4; break;
4459         default:
4460           return MCDisassembler::Fail;
4461       }
4462       break;
4463   }
4464 
4465   if (Rm != 0xF) { // Writeback
4466     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4467     return MCDisassembler::Fail;
4468   }
4469   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4470     return MCDisassembler::Fail;
4471   Inst.addOperand(MCOperand::createImm(align));
4472   if (Rm != 0xF) {
4473     if (Rm != 0xD) {
4474       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4475     return MCDisassembler::Fail;
4476     } else
4477       Inst.addOperand(MCOperand::createReg(0));
4478   }
4479 
4480   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4481     return MCDisassembler::Fail;
4482   Inst.addOperand(MCOperand::createImm(index));
4483 
4484   return S;
4485 }
4486 
4487 static DecodeStatus DecodeVLD2LN(MCInst &Inst, unsigned Insn,
4488                          uint64_t Address, const void *Decoder) {
4489   DecodeStatus S = MCDisassembler::Success;
4490 
4491   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4492   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4493   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4494   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4495   unsigned size = fieldFromInstruction(Insn, 10, 2);
4496 
4497   unsigned align = 0;
4498   unsigned index = 0;
4499   unsigned inc = 1;
4500   switch (size) {
4501     default:
4502       return MCDisassembler::Fail;
4503     case 0:
4504       index = fieldFromInstruction(Insn, 5, 3);
4505       if (fieldFromInstruction(Insn, 4, 1))
4506         align = 2;
4507       break;
4508     case 1:
4509       index = fieldFromInstruction(Insn, 6, 2);
4510       if (fieldFromInstruction(Insn, 4, 1))
4511         align = 4;
4512       if (fieldFromInstruction(Insn, 5, 1))
4513         inc = 2;
4514       break;
4515     case 2:
4516       if (fieldFromInstruction(Insn, 5, 1))
4517         return MCDisassembler::Fail; // UNDEFINED
4518       index = fieldFromInstruction(Insn, 7, 1);
4519       if (fieldFromInstruction(Insn, 4, 1) != 0)
4520         align = 8;
4521       if (fieldFromInstruction(Insn, 6, 1))
4522         inc = 2;
4523       break;
4524   }
4525 
4526   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4527     return MCDisassembler::Fail;
4528   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4529     return MCDisassembler::Fail;
4530   if (Rm != 0xF) { // Writeback
4531     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4532       return MCDisassembler::Fail;
4533   }
4534   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4535     return MCDisassembler::Fail;
4536   Inst.addOperand(MCOperand::createImm(align));
4537   if (Rm != 0xF) {
4538     if (Rm != 0xD) {
4539       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4540         return MCDisassembler::Fail;
4541     } else
4542       Inst.addOperand(MCOperand::createReg(0));
4543   }
4544 
4545   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4546     return MCDisassembler::Fail;
4547   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4548     return MCDisassembler::Fail;
4549   Inst.addOperand(MCOperand::createImm(index));
4550 
4551   return S;
4552 }
4553 
4554 static DecodeStatus DecodeVST2LN(MCInst &Inst, unsigned Insn,
4555                          uint64_t Address, const void *Decoder) {
4556   DecodeStatus S = MCDisassembler::Success;
4557 
4558   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4559   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4560   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4561   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4562   unsigned size = fieldFromInstruction(Insn, 10, 2);
4563 
4564   unsigned align = 0;
4565   unsigned index = 0;
4566   unsigned inc = 1;
4567   switch (size) {
4568     default:
4569       return MCDisassembler::Fail;
4570     case 0:
4571       index = fieldFromInstruction(Insn, 5, 3);
4572       if (fieldFromInstruction(Insn, 4, 1))
4573         align = 2;
4574       break;
4575     case 1:
4576       index = fieldFromInstruction(Insn, 6, 2);
4577       if (fieldFromInstruction(Insn, 4, 1))
4578         align = 4;
4579       if (fieldFromInstruction(Insn, 5, 1))
4580         inc = 2;
4581       break;
4582     case 2:
4583       if (fieldFromInstruction(Insn, 5, 1))
4584         return MCDisassembler::Fail; // UNDEFINED
4585       index = fieldFromInstruction(Insn, 7, 1);
4586       if (fieldFromInstruction(Insn, 4, 1) != 0)
4587         align = 8;
4588       if (fieldFromInstruction(Insn, 6, 1))
4589         inc = 2;
4590       break;
4591   }
4592 
4593   if (Rm != 0xF) { // Writeback
4594     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4595       return MCDisassembler::Fail;
4596   }
4597   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4598     return MCDisassembler::Fail;
4599   Inst.addOperand(MCOperand::createImm(align));
4600   if (Rm != 0xF) {
4601     if (Rm != 0xD) {
4602       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4603         return MCDisassembler::Fail;
4604     } else
4605       Inst.addOperand(MCOperand::createReg(0));
4606   }
4607 
4608   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4609     return MCDisassembler::Fail;
4610   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4611     return MCDisassembler::Fail;
4612   Inst.addOperand(MCOperand::createImm(index));
4613 
4614   return S;
4615 }
4616 
4617 static DecodeStatus DecodeVLD3LN(MCInst &Inst, unsigned Insn,
4618                          uint64_t Address, const void *Decoder) {
4619   DecodeStatus S = MCDisassembler::Success;
4620 
4621   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4622   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4623   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4624   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4625   unsigned size = fieldFromInstruction(Insn, 10, 2);
4626 
4627   unsigned align = 0;
4628   unsigned index = 0;
4629   unsigned inc = 1;
4630   switch (size) {
4631     default:
4632       return MCDisassembler::Fail;
4633     case 0:
4634       if (fieldFromInstruction(Insn, 4, 1))
4635         return MCDisassembler::Fail; // UNDEFINED
4636       index = fieldFromInstruction(Insn, 5, 3);
4637       break;
4638     case 1:
4639       if (fieldFromInstruction(Insn, 4, 1))
4640         return MCDisassembler::Fail; // UNDEFINED
4641       index = fieldFromInstruction(Insn, 6, 2);
4642       if (fieldFromInstruction(Insn, 5, 1))
4643         inc = 2;
4644       break;
4645     case 2:
4646       if (fieldFromInstruction(Insn, 4, 2))
4647         return MCDisassembler::Fail; // UNDEFINED
4648       index = fieldFromInstruction(Insn, 7, 1);
4649       if (fieldFromInstruction(Insn, 6, 1))
4650         inc = 2;
4651       break;
4652   }
4653 
4654   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4655     return MCDisassembler::Fail;
4656   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4657     return MCDisassembler::Fail;
4658   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
4659     return MCDisassembler::Fail;
4660 
4661   if (Rm != 0xF) { // Writeback
4662     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4663     return MCDisassembler::Fail;
4664   }
4665   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4666     return MCDisassembler::Fail;
4667   Inst.addOperand(MCOperand::createImm(align));
4668   if (Rm != 0xF) {
4669     if (Rm != 0xD) {
4670       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4671     return MCDisassembler::Fail;
4672     } else
4673       Inst.addOperand(MCOperand::createReg(0));
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   Inst.addOperand(MCOperand::createImm(index));
4683 
4684   return S;
4685 }
4686 
4687 static DecodeStatus DecodeVST3LN(MCInst &Inst, unsigned Insn,
4688                          uint64_t Address, const void *Decoder) {
4689   DecodeStatus S = MCDisassembler::Success;
4690 
4691   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4692   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4693   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4694   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4695   unsigned size = fieldFromInstruction(Insn, 10, 2);
4696 
4697   unsigned align = 0;
4698   unsigned index = 0;
4699   unsigned inc = 1;
4700   switch (size) {
4701     default:
4702       return MCDisassembler::Fail;
4703     case 0:
4704       if (fieldFromInstruction(Insn, 4, 1))
4705         return MCDisassembler::Fail; // UNDEFINED
4706       index = fieldFromInstruction(Insn, 5, 3);
4707       break;
4708     case 1:
4709       if (fieldFromInstruction(Insn, 4, 1))
4710         return MCDisassembler::Fail; // UNDEFINED
4711       index = fieldFromInstruction(Insn, 6, 2);
4712       if (fieldFromInstruction(Insn, 5, 1))
4713         inc = 2;
4714       break;
4715     case 2:
4716       if (fieldFromInstruction(Insn, 4, 2))
4717         return MCDisassembler::Fail; // UNDEFINED
4718       index = fieldFromInstruction(Insn, 7, 1);
4719       if (fieldFromInstruction(Insn, 6, 1))
4720         inc = 2;
4721       break;
4722   }
4723 
4724   if (Rm != 0xF) { // Writeback
4725     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4726     return MCDisassembler::Fail;
4727   }
4728   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4729     return MCDisassembler::Fail;
4730   Inst.addOperand(MCOperand::createImm(align));
4731   if (Rm != 0xF) {
4732     if (Rm != 0xD) {
4733       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4734     return MCDisassembler::Fail;
4735     } else
4736       Inst.addOperand(MCOperand::createReg(0));
4737   }
4738 
4739   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4740     return MCDisassembler::Fail;
4741   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4742     return MCDisassembler::Fail;
4743   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
4744     return MCDisassembler::Fail;
4745   Inst.addOperand(MCOperand::createImm(index));
4746 
4747   return S;
4748 }
4749 
4750 static DecodeStatus DecodeVLD4LN(MCInst &Inst, unsigned Insn,
4751                          uint64_t Address, const void *Decoder) {
4752   DecodeStatus S = MCDisassembler::Success;
4753 
4754   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4755   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4756   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4757   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4758   unsigned size = fieldFromInstruction(Insn, 10, 2);
4759 
4760   unsigned align = 0;
4761   unsigned index = 0;
4762   unsigned inc = 1;
4763   switch (size) {
4764     default:
4765       return MCDisassembler::Fail;
4766     case 0:
4767       if (fieldFromInstruction(Insn, 4, 1))
4768         align = 4;
4769       index = fieldFromInstruction(Insn, 5, 3);
4770       break;
4771     case 1:
4772       if (fieldFromInstruction(Insn, 4, 1))
4773         align = 8;
4774       index = fieldFromInstruction(Insn, 6, 2);
4775       if (fieldFromInstruction(Insn, 5, 1))
4776         inc = 2;
4777       break;
4778     case 2:
4779       switch (fieldFromInstruction(Insn, 4, 2)) {
4780         case 0:
4781           align = 0; break;
4782         case 3:
4783           return MCDisassembler::Fail;
4784         default:
4785           align = 4 << fieldFromInstruction(Insn, 4, 2); break;
4786       }
4787 
4788       index = fieldFromInstruction(Insn, 7, 1);
4789       if (fieldFromInstruction(Insn, 6, 1))
4790         inc = 2;
4791       break;
4792   }
4793 
4794   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4795     return MCDisassembler::Fail;
4796   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4797     return MCDisassembler::Fail;
4798   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
4799     return MCDisassembler::Fail;
4800   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
4801     return MCDisassembler::Fail;
4802 
4803   if (Rm != 0xF) { // Writeback
4804     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4805       return MCDisassembler::Fail;
4806   }
4807   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4808     return MCDisassembler::Fail;
4809   Inst.addOperand(MCOperand::createImm(align));
4810   if (Rm != 0xF) {
4811     if (Rm != 0xD) {
4812       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4813         return MCDisassembler::Fail;
4814     } else
4815       Inst.addOperand(MCOperand::createReg(0));
4816   }
4817 
4818   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4819     return MCDisassembler::Fail;
4820   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4821     return MCDisassembler::Fail;
4822   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
4823     return MCDisassembler::Fail;
4824   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
4825     return MCDisassembler::Fail;
4826   Inst.addOperand(MCOperand::createImm(index));
4827 
4828   return S;
4829 }
4830 
4831 static DecodeStatus DecodeVST4LN(MCInst &Inst, unsigned Insn,
4832                          uint64_t Address, const void *Decoder) {
4833   DecodeStatus S = MCDisassembler::Success;
4834 
4835   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4836   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4837   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4838   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4839   unsigned size = fieldFromInstruction(Insn, 10, 2);
4840 
4841   unsigned align = 0;
4842   unsigned index = 0;
4843   unsigned inc = 1;
4844   switch (size) {
4845     default:
4846       return MCDisassembler::Fail;
4847     case 0:
4848       if (fieldFromInstruction(Insn, 4, 1))
4849         align = 4;
4850       index = fieldFromInstruction(Insn, 5, 3);
4851       break;
4852     case 1:
4853       if (fieldFromInstruction(Insn, 4, 1))
4854         align = 8;
4855       index = fieldFromInstruction(Insn, 6, 2);
4856       if (fieldFromInstruction(Insn, 5, 1))
4857         inc = 2;
4858       break;
4859     case 2:
4860       switch (fieldFromInstruction(Insn, 4, 2)) {
4861         case 0:
4862           align = 0; break;
4863         case 3:
4864           return MCDisassembler::Fail;
4865         default:
4866           align = 4 << fieldFromInstruction(Insn, 4, 2); break;
4867       }
4868 
4869       index = fieldFromInstruction(Insn, 7, 1);
4870       if (fieldFromInstruction(Insn, 6, 1))
4871         inc = 2;
4872       break;
4873   }
4874 
4875   if (Rm != 0xF) { // Writeback
4876     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4877     return MCDisassembler::Fail;
4878   }
4879   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4880     return MCDisassembler::Fail;
4881   Inst.addOperand(MCOperand::createImm(align));
4882   if (Rm != 0xF) {
4883     if (Rm != 0xD) {
4884       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4885     return MCDisassembler::Fail;
4886     } else
4887       Inst.addOperand(MCOperand::createReg(0));
4888   }
4889 
4890   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4891     return MCDisassembler::Fail;
4892   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4893     return MCDisassembler::Fail;
4894   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
4895     return MCDisassembler::Fail;
4896   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
4897     return MCDisassembler::Fail;
4898   Inst.addOperand(MCOperand::createImm(index));
4899 
4900   return S;
4901 }
4902 
4903 static DecodeStatus DecodeVMOVSRR(MCInst &Inst, unsigned Insn,
4904                                   uint64_t Address, const void *Decoder) {
4905   DecodeStatus S = MCDisassembler::Success;
4906   unsigned Rt  = fieldFromInstruction(Insn, 12, 4);
4907   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
4908   unsigned Rm  = fieldFromInstruction(Insn,  5, 1);
4909   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4910   Rm |= fieldFromInstruction(Insn, 0, 4) << 1;
4911 
4912   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
4913     S = MCDisassembler::SoftFail;
4914 
4915   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
4916     return MCDisassembler::Fail;
4917   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
4918     return MCDisassembler::Fail;
4919   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
4920     return MCDisassembler::Fail;
4921   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
4922     return MCDisassembler::Fail;
4923   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4924     return MCDisassembler::Fail;
4925 
4926   return S;
4927 }
4928 
4929 static DecodeStatus DecodeVMOVRRS(MCInst &Inst, unsigned Insn,
4930                                   uint64_t Address, const void *Decoder) {
4931   DecodeStatus S = MCDisassembler::Success;
4932   unsigned Rt  = fieldFromInstruction(Insn, 12, 4);
4933   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
4934   unsigned Rm  = fieldFromInstruction(Insn,  5, 1);
4935   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4936   Rm |= fieldFromInstruction(Insn, 0, 4) << 1;
4937 
4938   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
4939     S = MCDisassembler::SoftFail;
4940 
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, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
4946     return MCDisassembler::Fail;
4947   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
4948     return MCDisassembler::Fail;
4949   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4950     return MCDisassembler::Fail;
4951 
4952   return S;
4953 }
4954 
4955 static DecodeStatus DecodeIT(MCInst &Inst, unsigned Insn,
4956                              uint64_t Address, const void *Decoder) {
4957   DecodeStatus S = MCDisassembler::Success;
4958   unsigned pred = fieldFromInstruction(Insn, 4, 4);
4959   unsigned mask = fieldFromInstruction(Insn, 0, 4);
4960 
4961   if (pred == 0xF) {
4962     pred = 0xE;
4963     S = MCDisassembler::SoftFail;
4964   }
4965 
4966   if (mask == 0x0)
4967     return MCDisassembler::Fail;
4968 
4969   Inst.addOperand(MCOperand::createImm(pred));
4970   Inst.addOperand(MCOperand::createImm(mask));
4971   return S;
4972 }
4973 
4974 static DecodeStatus
4975 DecodeT2LDRDPreInstruction(MCInst &Inst, unsigned Insn,
4976                            uint64_t Address, const void *Decoder) {
4977   DecodeStatus S = MCDisassembler::Success;
4978 
4979   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4980   unsigned Rt2 = fieldFromInstruction(Insn, 8, 4);
4981   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4982   unsigned addr = fieldFromInstruction(Insn, 0, 8);
4983   unsigned W = fieldFromInstruction(Insn, 21, 1);
4984   unsigned U = fieldFromInstruction(Insn, 23, 1);
4985   unsigned P = fieldFromInstruction(Insn, 24, 1);
4986   bool writeback = (W == 1) | (P == 0);
4987 
4988   addr |= (U << 8) | (Rn << 9);
4989 
4990   if (writeback && (Rn == Rt || Rn == Rt2))
4991     Check(S, MCDisassembler::SoftFail);
4992   if (Rt == Rt2)
4993     Check(S, MCDisassembler::SoftFail);
4994 
4995   // Rt
4996   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
4997     return MCDisassembler::Fail;
4998   // Rt2
4999   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
5000     return MCDisassembler::Fail;
5001   // Writeback operand
5002   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
5003     return MCDisassembler::Fail;
5004   // addr
5005   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
5006     return MCDisassembler::Fail;
5007 
5008   return S;
5009 }
5010 
5011 static DecodeStatus
5012 DecodeT2STRDPreInstruction(MCInst &Inst, unsigned Insn,
5013                            uint64_t Address, const void *Decoder) {
5014   DecodeStatus S = MCDisassembler::Success;
5015 
5016   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5017   unsigned Rt2 = fieldFromInstruction(Insn, 8, 4);
5018   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5019   unsigned addr = fieldFromInstruction(Insn, 0, 8);
5020   unsigned W = fieldFromInstruction(Insn, 21, 1);
5021   unsigned U = fieldFromInstruction(Insn, 23, 1);
5022   unsigned P = fieldFromInstruction(Insn, 24, 1);
5023   bool writeback = (W == 1) | (P == 0);
5024 
5025   addr |= (U << 8) | (Rn << 9);
5026 
5027   if (writeback && (Rn == Rt || Rn == Rt2))
5028     Check(S, MCDisassembler::SoftFail);
5029 
5030   // Writeback operand
5031   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
5032     return MCDisassembler::Fail;
5033   // Rt
5034   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
5035     return MCDisassembler::Fail;
5036   // Rt2
5037   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
5038     return MCDisassembler::Fail;
5039   // addr
5040   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
5041     return MCDisassembler::Fail;
5042 
5043   return S;
5044 }
5045 
5046 static DecodeStatus DecodeT2Adr(MCInst &Inst, uint32_t Insn,
5047                                 uint64_t Address, const void *Decoder) {
5048   unsigned sign1 = fieldFromInstruction(Insn, 21, 1);
5049   unsigned sign2 = fieldFromInstruction(Insn, 23, 1);
5050   if (sign1 != sign2) return MCDisassembler::Fail;
5051 
5052   unsigned Val = fieldFromInstruction(Insn, 0, 8);
5053   Val |= fieldFromInstruction(Insn, 12, 3) << 8;
5054   Val |= fieldFromInstruction(Insn, 26, 1) << 11;
5055   Val |= sign1 << 12;
5056   Inst.addOperand(MCOperand::createImm(SignExtend32<13>(Val)));
5057 
5058   return MCDisassembler::Success;
5059 }
5060 
5061 static DecodeStatus DecodeT2ShifterImmOperand(MCInst &Inst, uint32_t Val,
5062                                               uint64_t Address,
5063                                               const void *Decoder) {
5064   DecodeStatus S = MCDisassembler::Success;
5065 
5066   // Shift of "asr #32" is not allowed in Thumb2 mode.
5067   if (Val == 0x20) S = MCDisassembler::Fail;
5068   Inst.addOperand(MCOperand::createImm(Val));
5069   return S;
5070 }
5071 
5072 static DecodeStatus DecodeSwap(MCInst &Inst, unsigned Insn,
5073                                uint64_t Address, const void *Decoder) {
5074   unsigned Rt   = fieldFromInstruction(Insn, 12, 4);
5075   unsigned Rt2  = fieldFromInstruction(Insn, 0,  4);
5076   unsigned Rn   = fieldFromInstruction(Insn, 16, 4);
5077   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5078 
5079   if (pred == 0xF)
5080     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
5081 
5082   DecodeStatus S = MCDisassembler::Success;
5083 
5084   if (Rt == Rn || Rn == Rt2)
5085     S = MCDisassembler::SoftFail;
5086 
5087   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5088     return MCDisassembler::Fail;
5089   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5090     return MCDisassembler::Fail;
5091   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
5092     return MCDisassembler::Fail;
5093   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5094     return MCDisassembler::Fail;
5095 
5096   return S;
5097 }
5098 
5099 static DecodeStatus DecodeVCVTD(MCInst &Inst, unsigned Insn,
5100                                 uint64_t Address, const void *Decoder) {
5101   const FeatureBitset &featureBits =
5102       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5103   bool hasFullFP16 = featureBits[ARM::FeatureFullFP16];
5104 
5105   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5106   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5107   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5108   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5109   unsigned imm = fieldFromInstruction(Insn, 16, 6);
5110   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
5111   unsigned op = fieldFromInstruction(Insn, 5, 1);
5112 
5113   DecodeStatus S = MCDisassembler::Success;
5114 
5115   // If the top 3 bits of imm are clear, this is a VMOV (immediate)
5116   if (!(imm & 0x38)) {
5117     if (cmode == 0xF) {
5118       if (op == 1) return MCDisassembler::Fail;
5119       Inst.setOpcode(ARM::VMOVv2f32);
5120     }
5121     if (hasFullFP16) {
5122       if (cmode == 0xE) {
5123         if (op == 1) {
5124           Inst.setOpcode(ARM::VMOVv1i64);
5125         } else {
5126           Inst.setOpcode(ARM::VMOVv8i8);
5127         }
5128       }
5129       if (cmode == 0xD) {
5130         if (op == 1) {
5131           Inst.setOpcode(ARM::VMVNv2i32);
5132         } else {
5133           Inst.setOpcode(ARM::VMOVv2i32);
5134         }
5135       }
5136       if (cmode == 0xC) {
5137         if (op == 1) {
5138           Inst.setOpcode(ARM::VMVNv2i32);
5139         } else {
5140           Inst.setOpcode(ARM::VMOVv2i32);
5141         }
5142       }
5143     }
5144     return DecodeNEONModImmInstruction(Inst, Insn, Address, Decoder);
5145   }
5146 
5147   if (!(imm & 0x20)) return MCDisassembler::Fail;
5148 
5149   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
5150     return MCDisassembler::Fail;
5151   if (!Check(S, DecodeDPRRegisterClass(Inst, Vm, Address, Decoder)))
5152     return MCDisassembler::Fail;
5153   Inst.addOperand(MCOperand::createImm(64 - imm));
5154 
5155   return S;
5156 }
5157 
5158 static DecodeStatus DecodeVCVTQ(MCInst &Inst, unsigned Insn,
5159                                 uint64_t Address, const void *Decoder) {
5160   const FeatureBitset &featureBits =
5161       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5162   bool hasFullFP16 = featureBits[ARM::FeatureFullFP16];
5163 
5164   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5165   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5166   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5167   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5168   unsigned imm = fieldFromInstruction(Insn, 16, 6);
5169   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
5170   unsigned op = fieldFromInstruction(Insn, 5, 1);
5171 
5172   DecodeStatus S = MCDisassembler::Success;
5173 
5174   // If the top 3 bits of imm are clear, this is a VMOV (immediate)
5175   if (!(imm & 0x38)) {
5176     if (cmode == 0xF) {
5177       if (op == 1) return MCDisassembler::Fail;
5178       Inst.setOpcode(ARM::VMOVv4f32);
5179     }
5180     if (hasFullFP16) {
5181       if (cmode == 0xE) {
5182         if (op == 1) {
5183           Inst.setOpcode(ARM::VMOVv2i64);
5184         } else {
5185           Inst.setOpcode(ARM::VMOVv16i8);
5186         }
5187       }
5188       if (cmode == 0xD) {
5189         if (op == 1) {
5190           Inst.setOpcode(ARM::VMVNv4i32);
5191         } else {
5192           Inst.setOpcode(ARM::VMOVv4i32);
5193         }
5194       }
5195       if (cmode == 0xC) {
5196         if (op == 1) {
5197           Inst.setOpcode(ARM::VMVNv4i32);
5198         } else {
5199           Inst.setOpcode(ARM::VMOVv4i32);
5200         }
5201       }
5202     }
5203     return DecodeNEONModImmInstruction(Inst, Insn, Address, Decoder);
5204   }
5205 
5206   if (!(imm & 0x20)) return MCDisassembler::Fail;
5207 
5208   if (!Check(S, DecodeQPRRegisterClass(Inst, Vd, Address, Decoder)))
5209     return MCDisassembler::Fail;
5210   if (!Check(S, DecodeQPRRegisterClass(Inst, Vm, Address, Decoder)))
5211     return MCDisassembler::Fail;
5212   Inst.addOperand(MCOperand::createImm(64 - imm));
5213 
5214   return S;
5215 }
5216 
5217 static DecodeStatus DecodeLDR(MCInst &Inst, unsigned Val,
5218                                 uint64_t Address, const void *Decoder) {
5219   DecodeStatus S = MCDisassembler::Success;
5220 
5221   unsigned Rn = fieldFromInstruction(Val, 16, 4);
5222   unsigned Rt = fieldFromInstruction(Val, 12, 4);
5223   unsigned Rm = fieldFromInstruction(Val, 0, 4);
5224   Rm |= (fieldFromInstruction(Val, 23, 1) << 4);
5225   unsigned Cond = fieldFromInstruction(Val, 28, 4);
5226 
5227   if (fieldFromInstruction(Val, 8, 4) != 0 || Rn == Rt)
5228     S = MCDisassembler::SoftFail;
5229 
5230   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5231     return MCDisassembler::Fail;
5232   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
5233     return MCDisassembler::Fail;
5234   if (!Check(S, DecodeAddrMode7Operand(Inst, Rn, Address, Decoder)))
5235     return MCDisassembler::Fail;
5236   if (!Check(S, DecodePostIdxReg(Inst, Rm, Address, Decoder)))
5237     return MCDisassembler::Fail;
5238   if (!Check(S, DecodePredicateOperand(Inst, Cond, Address, Decoder)))
5239     return MCDisassembler::Fail;
5240 
5241   return S;
5242 }
5243 
5244 static DecodeStatus DecoderForMRRC2AndMCRR2(MCInst &Inst, unsigned Val,
5245                                             uint64_t Address, const void *Decoder) {
5246   DecodeStatus S = MCDisassembler::Success;
5247 
5248   unsigned CRm = fieldFromInstruction(Val, 0, 4);
5249   unsigned opc1 = fieldFromInstruction(Val, 4, 4);
5250   unsigned cop = fieldFromInstruction(Val, 8, 4);
5251   unsigned Rt = fieldFromInstruction(Val, 12, 4);
5252   unsigned Rt2 = fieldFromInstruction(Val, 16, 4);
5253 
5254   if ((cop & ~0x1) == 0xa)
5255     return MCDisassembler::Fail;
5256 
5257   if (Rt == Rt2)
5258     S = MCDisassembler::SoftFail;
5259 
5260   // We have to check if the instruction is MRRC2
5261   // or MCRR2 when constructing the operands for
5262   // Inst. Reason is because MRRC2 stores to two
5263   // registers so it's tablegen desc has has two
5264   // outputs whereas MCRR doesn't store to any
5265   // registers so all of it's operands are listed
5266   // as inputs, therefore the operand order for
5267   // MRRC2 needs to be [Rt, Rt2, cop, opc1, CRm]
5268   // and MCRR2 operand order is [cop, opc1, Rt, Rt2, CRm]
5269 
5270   if (Inst.getOpcode() == ARM::MRRC2) {
5271     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5272       return MCDisassembler::Fail;
5273     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5274       return MCDisassembler::Fail;
5275   }
5276   Inst.addOperand(MCOperand::createImm(cop));
5277   Inst.addOperand(MCOperand::createImm(opc1));
5278   if (Inst.getOpcode() == ARM::MCRR2) {
5279     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5280       return MCDisassembler::Fail;
5281     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5282       return MCDisassembler::Fail;
5283   }
5284   Inst.addOperand(MCOperand::createImm(CRm));
5285 
5286   return S;
5287 }
5288