xref: /llvm-project/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp (revision 6af366be8ad3199f715c54e84c779e02bb8c18b8)
1 //===- ARMDisassembler.cpp - Disassembler for ARM/Thumb ISA ---------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "MCTargetDesc/ARMAddressingModes.h"
10 #include "MCTargetDesc/ARMBaseInfo.h"
11 #include "MCTargetDesc/ARMMCTargetDesc.h"
12 #include "Utils/ARMBaseInfo.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 using DecodeStatus = MCDisassembler::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 
121   DecodeStatus AddThumbPredicate(MCInst&) const;
122   void UpdateThumbVFPPredicate(DecodeStatus &, MCInst&) const;
123 };
124 
125 } // end anonymous namespace
126 
127 static bool Check(DecodeStatus &Out, DecodeStatus In) {
128   switch (In) {
129     case MCDisassembler::Success:
130       // Out stays the same.
131       return true;
132     case MCDisassembler::SoftFail:
133       Out = In;
134       return true;
135     case MCDisassembler::Fail:
136       Out = In;
137       return false;
138   }
139   llvm_unreachable("Invalid DecodeStatus!");
140 }
141 
142 // Forward declare these because the autogenerated code will reference them.
143 // Definitions are further down.
144 static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, unsigned RegNo,
145                                    uint64_t Address, const void *Decoder);
146 static DecodeStatus DecodeGPRnopcRegisterClass(MCInst &Inst,
147                                                unsigned RegNo, uint64_t Address,
148                                                const void *Decoder);
149 static DecodeStatus DecodeGPRwithAPSRRegisterClass(MCInst &Inst,
150                                                unsigned RegNo, uint64_t Address,
151                                                const void *Decoder);
152 static DecodeStatus DecodetGPRRegisterClass(MCInst &Inst, unsigned RegNo,
153                                    uint64_t Address, const void *Decoder);
154 static DecodeStatus DecodetcGPRRegisterClass(MCInst &Inst, unsigned RegNo,
155                                    uint64_t Address, const void *Decoder);
156 static DecodeStatus DecoderGPRRegisterClass(MCInst &Inst, unsigned RegNo,
157                                    uint64_t Address, const void *Decoder);
158 static DecodeStatus DecodeGPRPairRegisterClass(MCInst &Inst, unsigned RegNo,
159                                    uint64_t Address, const void *Decoder);
160 static DecodeStatus DecodeHPRRegisterClass(MCInst &Inst, unsigned RegNo,
161                                    uint64_t Address, const void *Decoder);
162 static DecodeStatus DecodeSPRRegisterClass(MCInst &Inst, unsigned RegNo,
163                                    uint64_t Address, const void *Decoder);
164 static DecodeStatus DecodeDPRRegisterClass(MCInst &Inst, unsigned RegNo,
165                                    uint64_t Address, const void *Decoder);
166 static DecodeStatus DecodeDPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
167                                    uint64_t Address, const void *Decoder);
168 static DecodeStatus DecodeSPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
169                                    uint64_t Address, const void *Decoder);
170 static DecodeStatus DecodeDPR_VFP2RegisterClass(MCInst &Inst,
171                                                 unsigned RegNo,
172                                                 uint64_t Address,
173                                                 const void *Decoder);
174 static DecodeStatus DecodeQPRRegisterClass(MCInst &Inst, unsigned RegNo,
175                                    uint64_t Address, const void *Decoder);
176 static DecodeStatus DecodeDPairRegisterClass(MCInst &Inst, unsigned RegNo,
177                                    uint64_t Address, const void *Decoder);
178 static DecodeStatus DecodeDPairSpacedRegisterClass(MCInst &Inst,
179                                unsigned RegNo, uint64_t Address,
180                                const void *Decoder);
181 
182 static DecodeStatus DecodePredicateOperand(MCInst &Inst, unsigned Val,
183                                uint64_t Address, const void *Decoder);
184 static DecodeStatus DecodeCCOutOperand(MCInst &Inst, unsigned Val,
185                                uint64_t Address, const void *Decoder);
186 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Val,
187                                uint64_t Address, const void *Decoder);
188 static DecodeStatus DecodeSPRRegListOperand(MCInst &Inst, unsigned Val,
189                                uint64_t Address, const void *Decoder);
190 static DecodeStatus DecodeDPRRegListOperand(MCInst &Inst, unsigned Val,
191                                uint64_t Address, const void *Decoder);
192 
193 static DecodeStatus DecodeBitfieldMaskOperand(MCInst &Inst, unsigned Insn,
194                                uint64_t Address, const void *Decoder);
195 static DecodeStatus DecodeCopMemInstruction(MCInst &Inst, unsigned Insn,
196                                uint64_t Address, const void *Decoder);
197 static DecodeStatus DecodeAddrMode2IdxInstruction(MCInst &Inst,
198                                                   unsigned Insn,
199                                                   uint64_t Address,
200                                                   const void *Decoder);
201 static DecodeStatus DecodeSORegMemOperand(MCInst &Inst, unsigned Insn,
202                                uint64_t Address, const void *Decoder);
203 static DecodeStatus DecodeAddrMode3Instruction(MCInst &Inst,unsigned Insn,
204                                uint64_t Address, const void *Decoder);
205 static DecodeStatus DecodeSORegImmOperand(MCInst &Inst, unsigned Insn,
206                                uint64_t Address, const void *Decoder);
207 static DecodeStatus DecodeSORegRegOperand(MCInst &Inst, unsigned Insn,
208                                uint64_t Address, const void *Decoder);
209 
210 static DecodeStatus DecodeMemMultipleWritebackInstruction(MCInst & Inst,
211                                                   unsigned Insn,
212                                                   uint64_t Adddress,
213                                                   const void *Decoder);
214 static DecodeStatus DecodeT2MOVTWInstruction(MCInst &Inst, unsigned Insn,
215                                uint64_t Address, const void *Decoder);
216 static DecodeStatus DecodeArmMOVTWInstruction(MCInst &Inst, unsigned Insn,
217                                uint64_t Address, const void *Decoder);
218 static DecodeStatus DecodeSMLAInstruction(MCInst &Inst, unsigned Insn,
219                                uint64_t Address, const void *Decoder);
220 static DecodeStatus DecodeHINTInstruction(MCInst &Inst, unsigned Insn,
221                                uint64_t Address, const void *Decoder);
222 static DecodeStatus DecodeCPSInstruction(MCInst &Inst, unsigned Insn,
223                                uint64_t Address, const void *Decoder);
224 static DecodeStatus DecodeTSTInstruction(MCInst &Inst, unsigned Insn,
225                                uint64_t Address, const void *Decoder);
226 static DecodeStatus DecodeSETPANInstruction(MCInst &Inst, unsigned Insn,
227                                uint64_t Address, const void *Decoder);
228 static DecodeStatus DecodeT2CPSInstruction(MCInst &Inst, unsigned Insn,
229                                uint64_t Address, const void *Decoder);
230 static DecodeStatus DecodeAddrModeImm12Operand(MCInst &Inst, unsigned Val,
231                                uint64_t Address, const void *Decoder);
232 static DecodeStatus DecodeAddrMode5Operand(MCInst &Inst, unsigned Val,
233                                uint64_t Address, const void *Decoder);
234 static DecodeStatus DecodeAddrMode5FP16Operand(MCInst &Inst, unsigned Val,
235                                uint64_t Address, const void *Decoder);
236 static DecodeStatus DecodeAddrMode7Operand(MCInst &Inst, unsigned Val,
237                                uint64_t Address, const void *Decoder);
238 static DecodeStatus DecodeT2BInstruction(MCInst &Inst, unsigned Insn,
239                                uint64_t Address, const void *Decoder);
240 static DecodeStatus DecodeBranchImmInstruction(MCInst &Inst,unsigned Insn,
241                                uint64_t Address, const void *Decoder);
242 static DecodeStatus DecodeAddrMode6Operand(MCInst &Inst, unsigned Val,
243                                uint64_t Address, const void *Decoder);
244 static DecodeStatus DecodeVLDST1Instruction(MCInst &Inst, unsigned Val,
245                                uint64_t Address, const void *Decoder);
246 static DecodeStatus DecodeVLDST2Instruction(MCInst &Inst, unsigned Val,
247                                uint64_t Address, const void *Decoder);
248 static DecodeStatus DecodeVLDST3Instruction(MCInst &Inst, unsigned Val,
249                                uint64_t Address, const void *Decoder);
250 static DecodeStatus DecodeVLDST4Instruction(MCInst &Inst, unsigned Val,
251                                uint64_t Address, const void *Decoder);
252 static DecodeStatus DecodeVLDInstruction(MCInst &Inst, unsigned Val,
253                                uint64_t Address, const void *Decoder);
254 static DecodeStatus DecodeVSTInstruction(MCInst &Inst, unsigned Val,
255                                uint64_t Address, const void *Decoder);
256 static DecodeStatus DecodeVLD1DupInstruction(MCInst &Inst, unsigned Val,
257                                uint64_t Address, const void *Decoder);
258 static DecodeStatus DecodeVLD2DupInstruction(MCInst &Inst, unsigned Val,
259                                uint64_t Address, const void *Decoder);
260 static DecodeStatus DecodeVLD3DupInstruction(MCInst &Inst, unsigned Val,
261                                uint64_t Address, const void *Decoder);
262 static DecodeStatus DecodeVLD4DupInstruction(MCInst &Inst, unsigned Val,
263                                uint64_t Address, const void *Decoder);
264 static DecodeStatus DecodeNEONModImmInstruction(MCInst &Inst,unsigned Val,
265                                uint64_t Address, const void *Decoder);
266 static DecodeStatus DecodeVSHLMaxInstruction(MCInst &Inst, unsigned Val,
267                                uint64_t Address, const void *Decoder);
268 static DecodeStatus DecodeShiftRight8Imm(MCInst &Inst, unsigned Val,
269                                uint64_t Address, const void *Decoder);
270 static DecodeStatus DecodeShiftRight16Imm(MCInst &Inst, unsigned Val,
271                                uint64_t Address, const void *Decoder);
272 static DecodeStatus DecodeShiftRight32Imm(MCInst &Inst, unsigned Val,
273                                uint64_t Address, const void *Decoder);
274 static DecodeStatus DecodeShiftRight64Imm(MCInst &Inst, unsigned Val,
275                                uint64_t Address, const void *Decoder);
276 static DecodeStatus DecodeTBLInstruction(MCInst &Inst, unsigned Insn,
277                                uint64_t Address, const void *Decoder);
278 static DecodeStatus DecodePostIdxReg(MCInst &Inst, unsigned Insn,
279                                uint64_t Address, const void *Decoder);
280 static DecodeStatus DecodeCoprocessor(MCInst &Inst, unsigned Insn,
281                                uint64_t Address, const void *Decoder);
282 static DecodeStatus DecodeMemBarrierOption(MCInst &Inst, unsigned Insn,
283                                uint64_t Address, const void *Decoder);
284 static DecodeStatus DecodeInstSyncBarrierOption(MCInst &Inst, unsigned Insn,
285                                uint64_t Address, const void *Decoder);
286 static DecodeStatus DecodeMSRMask(MCInst &Inst, unsigned Insn,
287                                uint64_t Address, const void *Decoder);
288 static DecodeStatus DecodeBankedReg(MCInst &Inst, unsigned Insn,
289                                uint64_t Address, const void *Decoder);
290 static DecodeStatus DecodeDoubleRegLoad(MCInst &Inst, unsigned Insn,
291                                uint64_t Address, const void *Decoder);
292 static DecodeStatus DecodeDoubleRegStore(MCInst &Inst, unsigned Insn,
293                                uint64_t Address, const void *Decoder);
294 static DecodeStatus DecodeLDRPreImm(MCInst &Inst, unsigned Insn,
295                                uint64_t Address, const void *Decoder);
296 static DecodeStatus DecodeLDRPreReg(MCInst &Inst, unsigned Insn,
297                                uint64_t Address, const void *Decoder);
298 static DecodeStatus DecodeSTRPreImm(MCInst &Inst, unsigned Insn,
299                                uint64_t Address, const void *Decoder);
300 static DecodeStatus DecodeSTRPreReg(MCInst &Inst, unsigned Insn,
301                                uint64_t Address, const void *Decoder);
302 static DecodeStatus DecodeVLD1LN(MCInst &Inst, unsigned Insn,
303                                uint64_t Address, const void *Decoder);
304 static DecodeStatus DecodeVLD2LN(MCInst &Inst, unsigned Insn,
305                                uint64_t Address, const void *Decoder);
306 static DecodeStatus DecodeVLD3LN(MCInst &Inst, unsigned Insn,
307                                uint64_t Address, const void *Decoder);
308 static DecodeStatus DecodeVLD4LN(MCInst &Inst, unsigned Insn,
309                                uint64_t Address, const void *Decoder);
310 static DecodeStatus DecodeVST1LN(MCInst &Inst, unsigned Insn,
311                                uint64_t Address, const void *Decoder);
312 static DecodeStatus DecodeVST2LN(MCInst &Inst, unsigned Insn,
313                                uint64_t Address, const void *Decoder);
314 static DecodeStatus DecodeVST3LN(MCInst &Inst, unsigned Insn,
315                                uint64_t Address, const void *Decoder);
316 static DecodeStatus DecodeVST4LN(MCInst &Inst, unsigned Insn,
317                                uint64_t Address, const void *Decoder);
318 static DecodeStatus DecodeVMOVSRR(MCInst &Inst, unsigned Insn,
319                                uint64_t Address, const void *Decoder);
320 static DecodeStatus DecodeVMOVRRS(MCInst &Inst, unsigned Insn,
321                                uint64_t Address, const void *Decoder);
322 static DecodeStatus DecodeSwap(MCInst &Inst, unsigned Insn,
323                                uint64_t Address, const void *Decoder);
324 static DecodeStatus DecodeVCVTD(MCInst &Inst, unsigned Insn,
325                                 uint64_t Address, const void *Decoder);
326 static DecodeStatus DecodeVCVTQ(MCInst &Inst, unsigned Insn,
327                                 uint64_t Address, const void *Decoder);
328 static DecodeStatus DecodeNEONComplexLane64Instruction(MCInst &Inst,
329                                                        unsigned Val,
330                                                        uint64_t Address,
331                                                        const void *Decoder);
332 
333 static DecodeStatus DecodeThumbAddSpecialReg(MCInst &Inst, uint16_t Insn,
334                                uint64_t Address, const void *Decoder);
335 static DecodeStatus DecodeThumbBROperand(MCInst &Inst, unsigned Val,
336                                uint64_t Address, const void *Decoder);
337 static DecodeStatus DecodeT2BROperand(MCInst &Inst, unsigned Val,
338                                uint64_t Address, const void *Decoder);
339 static DecodeStatus DecodeThumbCmpBROperand(MCInst &Inst, unsigned Val,
340                                uint64_t Address, const void *Decoder);
341 static DecodeStatus DecodeThumbAddrModeRR(MCInst &Inst, unsigned Val,
342                                uint64_t Address, const void *Decoder);
343 static DecodeStatus DecodeThumbAddrModeIS(MCInst &Inst, unsigned Val,
344                                uint64_t Address, const void *Decoder);
345 static DecodeStatus DecodeThumbAddrModePC(MCInst &Inst, unsigned Val,
346                                uint64_t Address, const void *Decoder);
347 static DecodeStatus DecodeThumbAddrModeSP(MCInst &Inst, unsigned Val,
348                                uint64_t Address, const void *Decoder);
349 static DecodeStatus DecodeT2AddrModeSOReg(MCInst &Inst, unsigned Val,
350                                uint64_t Address, const void *Decoder);
351 static DecodeStatus DecodeT2LoadShift(MCInst &Inst, unsigned Val,
352                                uint64_t Address, const void *Decoder);
353 static DecodeStatus DecodeT2LoadImm8(MCInst &Inst, unsigned Insn,
354                                uint64_t Address, const void* Decoder);
355 static DecodeStatus DecodeT2LoadImm12(MCInst &Inst, unsigned Insn,
356                                uint64_t Address, const void* Decoder);
357 static DecodeStatus DecodeT2LoadT(MCInst &Inst, unsigned Insn,
358                                uint64_t Address, const void* Decoder);
359 static DecodeStatus DecodeT2LoadLabel(MCInst &Inst, unsigned Insn,
360                                uint64_t Address, const void* Decoder);
361 static DecodeStatus DecodeT2Imm8S4(MCInst &Inst, unsigned Val,
362                                uint64_t Address, const void *Decoder);
363 static DecodeStatus DecodeT2AddrModeImm8s4(MCInst &Inst, unsigned Val,
364                                uint64_t Address, const void *Decoder);
365 static DecodeStatus DecodeT2AddrModeImm0_1020s4(MCInst &Inst,unsigned Val,
366                                uint64_t Address, const void *Decoder);
367 static DecodeStatus DecodeT2Imm8(MCInst &Inst, unsigned Val,
368                                uint64_t Address, const void *Decoder);
369 static DecodeStatus DecodeT2AddrModeImm8(MCInst &Inst, unsigned Val,
370                                uint64_t Address, const void *Decoder);
371 static DecodeStatus DecodeThumbAddSPImm(MCInst &Inst, uint16_t Val,
372                                uint64_t Address, const void *Decoder);
373 static DecodeStatus DecodeThumbAddSPReg(MCInst &Inst, uint16_t Insn,
374                                 uint64_t Address, const void *Decoder);
375 static DecodeStatus DecodeThumbCPS(MCInst &Inst, uint16_t Insn,
376                                 uint64_t Address, const void *Decoder);
377 static DecodeStatus DecodeQADDInstruction(MCInst &Inst, unsigned Insn,
378                                 uint64_t Address, const void *Decoder);
379 static DecodeStatus DecodeThumbBLXOffset(MCInst &Inst, unsigned Insn,
380                                 uint64_t Address, const void *Decoder);
381 static DecodeStatus DecodeT2AddrModeImm12(MCInst &Inst, unsigned Val,
382                                 uint64_t Address, const void *Decoder);
383 static DecodeStatus DecodeThumbTableBranch(MCInst &Inst, unsigned Val,
384                                 uint64_t Address, const void *Decoder);
385 static DecodeStatus DecodeThumb2BCCInstruction(MCInst &Inst, unsigned Val,
386                                 uint64_t Address, const void *Decoder);
387 static DecodeStatus DecodeT2SOImm(MCInst &Inst, unsigned Val,
388                                 uint64_t Address, const void *Decoder);
389 static DecodeStatus DecodeThumbBCCTargetOperand(MCInst &Inst,unsigned Val,
390                                 uint64_t Address, const void *Decoder);
391 static DecodeStatus DecodeThumbBLTargetOperand(MCInst &Inst, unsigned Val,
392                                 uint64_t Address, const void *Decoder);
393 static DecodeStatus DecodeIT(MCInst &Inst, unsigned Val,
394                                 uint64_t Address, const void *Decoder);
395 static DecodeStatus DecodeT2LDRDPreInstruction(MCInst &Inst,unsigned Insn,
396                                uint64_t Address, const void *Decoder);
397 static DecodeStatus DecodeT2STRDPreInstruction(MCInst &Inst,unsigned Insn,
398                                uint64_t Address, const void *Decoder);
399 static DecodeStatus DecodeT2Adr(MCInst &Inst, unsigned Val,
400                                 uint64_t Address, const void *Decoder);
401 static DecodeStatus DecodeT2LdStPre(MCInst &Inst, unsigned Val,
402                                 uint64_t Address, const void *Decoder);
403 static DecodeStatus DecodeT2ShifterImmOperand(MCInst &Inst, unsigned Val,
404                                 uint64_t Address, const void *Decoder);
405 
406 static DecodeStatus DecodeLDR(MCInst &Inst, unsigned Val,
407                                 uint64_t Address, const void *Decoder);
408 static DecodeStatus DecoderForMRRC2AndMCRR2(MCInst &Inst, unsigned Val,
409                                             uint64_t Address, const void *Decoder);
410 static DecodeStatus DecodeForVMRSandVMSR(MCInst &Inst, unsigned Val,
411                                          uint64_t Address, const void *Decoder);
412 
413 #include "ARMGenDisassemblerTables.inc"
414 
415 static MCDisassembler *createARMDisassembler(const Target &T,
416                                              const MCSubtargetInfo &STI,
417                                              MCContext &Ctx) {
418   return new ARMDisassembler(STI, Ctx);
419 }
420 
421 static MCDisassembler *createThumbDisassembler(const Target &T,
422                                                const MCSubtargetInfo &STI,
423                                                MCContext &Ctx) {
424   return new ThumbDisassembler(STI, Ctx);
425 }
426 
427 // Post-decoding checks
428 static DecodeStatus checkDecodedInstruction(MCInst &MI, uint64_t &Size,
429                                             uint64_t Address, raw_ostream &OS,
430                                             raw_ostream &CS,
431                                             uint32_t Insn,
432                                             DecodeStatus Result) {
433   switch (MI.getOpcode()) {
434     case ARM::HVC: {
435       // HVC is undefined if condition = 0xf otherwise upredictable
436       // if condition != 0xe
437       uint32_t Cond = (Insn >> 28) & 0xF;
438       if (Cond == 0xF)
439         return MCDisassembler::Fail;
440       if (Cond != 0xE)
441         return MCDisassembler::SoftFail;
442       return Result;
443     }
444     case ARM::t2ADDri:
445     case ARM::t2ADDri12:
446     case ARM::t2ADDrr:
447     case ARM::t2ADDrs:
448     case ARM::t2SUBri:
449     case ARM::t2SUBri12:
450     case ARM::t2SUBrr:
451     case ARM::t2SUBrs:
452       if (MI.getOperand(0).getReg() == ARM::SP &&
453           MI.getOperand(1).getReg() != ARM::SP)
454         return MCDisassembler::SoftFail;
455       return Result;
456     default: return Result;
457   }
458 }
459 
460 DecodeStatus ARMDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
461                                              ArrayRef<uint8_t> Bytes,
462                                              uint64_t Address, raw_ostream &OS,
463                                              raw_ostream &CS) const {
464   CommentStream = &CS;
465 
466   assert(!STI.getFeatureBits()[ARM::ModeThumb] &&
467          "Asked to disassemble an ARM instruction but Subtarget is in Thumb "
468          "mode!");
469 
470   // We want to read exactly 4 bytes of data.
471   if (Bytes.size() < 4) {
472     Size = 0;
473     return MCDisassembler::Fail;
474   }
475 
476   // Encoded as a small-endian 32-bit word in the stream.
477   uint32_t Insn =
478       (Bytes[3] << 24) | (Bytes[2] << 16) | (Bytes[1] << 8) | (Bytes[0] << 0);
479 
480   // Calling the auto-generated decoder function.
481   DecodeStatus Result =
482       decodeInstruction(DecoderTableARM32, MI, Insn, Address, this, STI);
483   if (Result != MCDisassembler::Fail) {
484     Size = 4;
485     return checkDecodedInstruction(MI, Size, Address, OS, CS, Insn, Result);
486   }
487 
488   struct DecodeTable {
489     const uint8_t *P;
490     bool DecodePred;
491   };
492 
493   const DecodeTable Tables[] = {
494       {DecoderTableVFP32, false},      {DecoderTableVFPV832, false},
495       {DecoderTableNEONData32, true},  {DecoderTableNEONLoadStore32, true},
496       {DecoderTableNEONDup32, true},   {DecoderTablev8NEON32, false},
497       {DecoderTablev8Crypto32, false},
498   };
499 
500   for (auto Table : Tables) {
501     Result = decodeInstruction(Table.P, MI, Insn, Address, this, STI);
502     if (Result != MCDisassembler::Fail) {
503       Size = 4;
504       // Add a fake predicate operand, because we share these instruction
505       // definitions with Thumb2 where these instructions are predicable.
506       if (Table.DecodePred && !DecodePredicateOperand(MI, 0xE, Address, this))
507         return MCDisassembler::Fail;
508       return Result;
509     }
510   }
511 
512   Result =
513       decodeInstruction(DecoderTableCoProc32, MI, Insn, Address, this, STI);
514   if (Result != MCDisassembler::Fail) {
515     Size = 4;
516     return checkDecodedInstruction(MI, Size, Address, OS, CS, Insn, Result);
517   }
518 
519   Size = 4;
520   return MCDisassembler::Fail;
521 }
522 
523 namespace llvm {
524 
525 extern const MCInstrDesc ARMInsts[];
526 
527 } // end namespace llvm
528 
529 /// tryAddingSymbolicOperand - trys to add a symbolic operand in place of the
530 /// immediate Value in the MCInst.  The immediate Value has had any PC
531 /// adjustment made by the caller.  If the instruction is a branch instruction
532 /// then isBranch is true, else false.  If the getOpInfo() function was set as
533 /// part of the setupForSymbolicDisassembly() call then that function is called
534 /// to get any symbolic information at the Address for this instruction.  If
535 /// that returns non-zero then the symbolic information it returns is used to
536 /// create an MCExpr and that is added as an operand to the MCInst.  If
537 /// getOpInfo() returns zero and isBranch is true then a symbol look up for
538 /// Value is done and if a symbol is found an MCExpr is created with that, else
539 /// an MCExpr with Value is created.  This function returns true if it adds an
540 /// operand to the MCInst and false otherwise.
541 static bool tryAddingSymbolicOperand(uint64_t Address, int32_t Value,
542                                      bool isBranch, uint64_t InstSize,
543                                      MCInst &MI, const void *Decoder) {
544   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
545   // FIXME: Does it make sense for value to be negative?
546   return Dis->tryAddingSymbolicOperand(MI, (uint32_t)Value, Address, isBranch,
547                                        /* Offset */ 0, InstSize);
548 }
549 
550 /// tryAddingPcLoadReferenceComment - trys to add a comment as to what is being
551 /// referenced by a load instruction with the base register that is the Pc.
552 /// These can often be values in a literal pool near the Address of the
553 /// instruction.  The Address of the instruction and its immediate Value are
554 /// used as a possible literal pool entry.  The SymbolLookUp call back will
555 /// return the name of a symbol referenced by the literal pool's entry if
556 /// the referenced address is that of a symbol.  Or it will return a pointer to
557 /// a literal 'C' string if the referenced address of the literal pool's entry
558 /// is an address into a section with 'C' string literals.
559 static void tryAddingPcLoadReferenceComment(uint64_t Address, int Value,
560                                             const void *Decoder) {
561   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
562   Dis->tryAddingPcLoadReferenceComment(Value, Address);
563 }
564 
565 // Thumb1 instructions don't have explicit S bits.  Rather, they
566 // implicitly set CPSR.  Since it's not represented in the encoding, the
567 // auto-generated decoder won't inject the CPSR operand.  We need to fix
568 // that as a post-pass.
569 static void AddThumb1SBit(MCInst &MI, bool InITBlock) {
570   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
571   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
572   MCInst::iterator I = MI.begin();
573   for (unsigned i = 0; i < NumOps; ++i, ++I) {
574     if (I == MI.end()) break;
575     if (OpInfo[i].isOptionalDef() && OpInfo[i].RegClass == ARM::CCRRegClassID) {
576       if (i > 0 && OpInfo[i-1].isPredicate()) continue;
577       MI.insert(I, MCOperand::createReg(InITBlock ? 0 : ARM::CPSR));
578       return;
579     }
580   }
581 
582   MI.insert(I, MCOperand::createReg(InITBlock ? 0 : ARM::CPSR));
583 }
584 
585 // Most Thumb instructions don't have explicit predicates in the
586 // encoding, but rather get their predicates from IT context.  We need
587 // to fix up the predicate operands using this context information as a
588 // post-pass.
589 MCDisassembler::DecodeStatus
590 ThumbDisassembler::AddThumbPredicate(MCInst &MI) const {
591   MCDisassembler::DecodeStatus S = Success;
592 
593   const FeatureBitset &FeatureBits = getSubtargetInfo().getFeatureBits();
594 
595   // A few instructions actually have predicates encoded in them.  Don't
596   // try to overwrite it if we're seeing one of those.
597   switch (MI.getOpcode()) {
598     case ARM::tBcc:
599     case ARM::t2Bcc:
600     case ARM::tCBZ:
601     case ARM::tCBNZ:
602     case ARM::tCPS:
603     case ARM::t2CPS3p:
604     case ARM::t2CPS2p:
605     case ARM::t2CPS1p:
606     case ARM::tMOVSr:
607     case ARM::tSETEND:
608       // Some instructions (mostly conditional branches) are not
609       // allowed in IT blocks.
610       if (ITBlock.instrInITBlock())
611         S = SoftFail;
612       else
613         return Success;
614       break;
615     case ARM::t2HINT:
616       if (MI.getOperand(0).getImm() == 0x10 && (FeatureBits[ARM::FeatureRAS]) != 0)
617         S = SoftFail;
618       break;
619     case ARM::tB:
620     case ARM::t2B:
621     case ARM::t2TBB:
622     case ARM::t2TBH:
623       // Some instructions (mostly unconditional branches) can
624       // only appears at the end of, or outside of, an IT.
625       if (ITBlock.instrInITBlock() && !ITBlock.instrLastInITBlock())
626         S = SoftFail;
627       break;
628     default:
629       break;
630   }
631 
632   // If we're in an IT block, base the predicate on that.  Otherwise,
633   // assume a predicate of AL.
634   unsigned CC;
635   CC = ITBlock.getITCC();
636   if (CC == 0xF)
637     CC = ARMCC::AL;
638   if (ITBlock.instrInITBlock())
639     ITBlock.advanceITState();
640 
641   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
642   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
643   MCInst::iterator I = MI.begin();
644   for (unsigned i = 0; i < NumOps; ++i, ++I) {
645     if (I == MI.end()) break;
646     if (OpInfo[i].isPredicate()) {
647       if (CC != ARMCC::AL && !ARMInsts[MI.getOpcode()].isPredicable())
648         Check(S, SoftFail);
649       I = MI.insert(I, MCOperand::createImm(CC));
650       ++I;
651       if (CC == ARMCC::AL)
652         MI.insert(I, MCOperand::createReg(0));
653       else
654         MI.insert(I, MCOperand::createReg(ARM::CPSR));
655       return S;
656     }
657   }
658 
659   I = MI.insert(I, MCOperand::createImm(CC));
660   ++I;
661   if (CC == ARMCC::AL)
662     MI.insert(I, MCOperand::createReg(0));
663   else
664     MI.insert(I, MCOperand::createReg(ARM::CPSR));
665 
666   return S;
667 }
668 
669 // Thumb VFP instructions are a special case.  Because we share their
670 // encodings between ARM and Thumb modes, and they are predicable in ARM
671 // mode, the auto-generated decoder will give them an (incorrect)
672 // predicate operand.  We need to rewrite these operands based on the IT
673 // context as a post-pass.
674 void ThumbDisassembler::UpdateThumbVFPPredicate(
675   DecodeStatus &S, MCInst &MI) const {
676   unsigned CC;
677   CC = ITBlock.getITCC();
678   if (CC == 0xF)
679     CC = ARMCC::AL;
680   if (ITBlock.instrInITBlock())
681     ITBlock.advanceITState();
682 
683   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
684   MCInst::iterator I = MI.begin();
685   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
686   for (unsigned i = 0; i < NumOps; ++i, ++I) {
687     if (OpInfo[i].isPredicate() ) {
688       if (CC != ARMCC::AL && !ARMInsts[MI.getOpcode()].isPredicable())
689         Check(S, SoftFail);
690       I->setImm(CC);
691       ++I;
692       if (CC == ARMCC::AL)
693         I->setReg(0);
694       else
695         I->setReg(ARM::CPSR);
696       return;
697     }
698   }
699 }
700 
701 DecodeStatus ThumbDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
702                                                ArrayRef<uint8_t> Bytes,
703                                                uint64_t Address,
704                                                raw_ostream &OS,
705                                                raw_ostream &CS) const {
706   CommentStream = &CS;
707 
708   assert(STI.getFeatureBits()[ARM::ModeThumb] &&
709          "Asked to disassemble in Thumb mode but Subtarget is in ARM mode!");
710 
711   // We want to read exactly 2 bytes of data.
712   if (Bytes.size() < 2) {
713     Size = 0;
714     return MCDisassembler::Fail;
715   }
716 
717   uint16_t Insn16 = (Bytes[1] << 8) | Bytes[0];
718   DecodeStatus Result =
719       decodeInstruction(DecoderTableThumb16, MI, Insn16, Address, this, STI);
720   if (Result != MCDisassembler::Fail) {
721     Size = 2;
722     Check(Result, AddThumbPredicate(MI));
723     return Result;
724   }
725 
726   Result = decodeInstruction(DecoderTableThumbSBit16, MI, Insn16, Address, this,
727                              STI);
728   if (Result) {
729     Size = 2;
730     bool InITBlock = ITBlock.instrInITBlock();
731     Check(Result, AddThumbPredicate(MI));
732     AddThumb1SBit(MI, InITBlock);
733     return Result;
734   }
735 
736   Result =
737       decodeInstruction(DecoderTableThumb216, MI, Insn16, Address, this, STI);
738   if (Result != MCDisassembler::Fail) {
739     Size = 2;
740 
741     // Nested IT blocks are UNPREDICTABLE.  Must be checked before we add
742     // the Thumb predicate.
743     if (MI.getOpcode() == ARM::t2IT && ITBlock.instrInITBlock())
744       Result = MCDisassembler::SoftFail;
745 
746     Check(Result, AddThumbPredicate(MI));
747 
748     // If we find an IT instruction, we need to parse its condition
749     // code and mask operands so that we can apply them correctly
750     // to the subsequent instructions.
751     if (MI.getOpcode() == ARM::t2IT) {
752       unsigned Firstcond = MI.getOperand(0).getImm();
753       unsigned Mask = MI.getOperand(1).getImm();
754       ITBlock.setITState(Firstcond, Mask);
755 
756       // An IT instruction that would give a 'NV' predicate is unpredictable.
757       if (Firstcond == ARMCC::AL && !isPowerOf2_32(Mask))
758         CS << "unpredictable IT predicate sequence";
759     }
760 
761     return Result;
762   }
763 
764   // We want to read exactly 4 bytes of data.
765   if (Bytes.size() < 4) {
766     Size = 0;
767     return MCDisassembler::Fail;
768   }
769 
770   uint32_t Insn32 =
771       (Bytes[3] << 8) | (Bytes[2] << 0) | (Bytes[1] << 24) | (Bytes[0] << 16);
772   Result =
773       decodeInstruction(DecoderTableThumb32, MI, Insn32, Address, this, STI);
774   if (Result != MCDisassembler::Fail) {
775     Size = 4;
776     bool InITBlock = ITBlock.instrInITBlock();
777     Check(Result, AddThumbPredicate(MI));
778     AddThumb1SBit(MI, InITBlock);
779     return Result;
780   }
781 
782   Result =
783       decodeInstruction(DecoderTableThumb232, MI, Insn32, Address, this, STI);
784   if (Result != MCDisassembler::Fail) {
785     Size = 4;
786     Check(Result, AddThumbPredicate(MI));
787     return checkDecodedInstruction(MI, Size, Address, OS, CS, Insn32, Result);
788   }
789 
790   if (fieldFromInstruction(Insn32, 28, 4) == 0xE) {
791     Result =
792         decodeInstruction(DecoderTableVFP32, MI, Insn32, Address, this, STI);
793     if (Result != MCDisassembler::Fail) {
794       Size = 4;
795       UpdateThumbVFPPredicate(Result, MI);
796       return Result;
797     }
798   }
799 
800   Result =
801       decodeInstruction(DecoderTableVFPV832, MI, Insn32, Address, this, STI);
802   if (Result != MCDisassembler::Fail) {
803     Size = 4;
804     return Result;
805   }
806 
807   if (fieldFromInstruction(Insn32, 28, 4) == 0xE) {
808     Result = decodeInstruction(DecoderTableNEONDup32, MI, Insn32, Address, this,
809                                STI);
810     if (Result != MCDisassembler::Fail) {
811       Size = 4;
812       Check(Result, AddThumbPredicate(MI));
813       return Result;
814     }
815   }
816 
817   if (fieldFromInstruction(Insn32, 24, 8) == 0xF9) {
818     uint32_t NEONLdStInsn = Insn32;
819     NEONLdStInsn &= 0xF0FFFFFF;
820     NEONLdStInsn |= 0x04000000;
821     Result = decodeInstruction(DecoderTableNEONLoadStore32, MI, NEONLdStInsn,
822                                Address, this, STI);
823     if (Result != MCDisassembler::Fail) {
824       Size = 4;
825       Check(Result, AddThumbPredicate(MI));
826       return Result;
827     }
828   }
829 
830   if (fieldFromInstruction(Insn32, 24, 4) == 0xF) {
831     uint32_t NEONDataInsn = Insn32;
832     NEONDataInsn &= 0xF0FFFFFF; // Clear bits 27-24
833     NEONDataInsn |= (NEONDataInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
834     NEONDataInsn |= 0x12000000; // Set bits 28 and 25
835     Result = decodeInstruction(DecoderTableNEONData32, MI, NEONDataInsn,
836                                Address, this, STI);
837     if (Result != MCDisassembler::Fail) {
838       Size = 4;
839       Check(Result, AddThumbPredicate(MI));
840       return Result;
841     }
842 
843     uint32_t NEONCryptoInsn = Insn32;
844     NEONCryptoInsn &= 0xF0FFFFFF; // Clear bits 27-24
845     NEONCryptoInsn |= (NEONCryptoInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
846     NEONCryptoInsn |= 0x12000000; // Set bits 28 and 25
847     Result = decodeInstruction(DecoderTablev8Crypto32, MI, NEONCryptoInsn,
848                                Address, this, STI);
849     if (Result != MCDisassembler::Fail) {
850       Size = 4;
851       return Result;
852     }
853 
854     uint32_t NEONv8Insn = Insn32;
855     NEONv8Insn &= 0xF3FFFFFF; // Clear bits 27-26
856     Result = decodeInstruction(DecoderTablev8NEON32, MI, NEONv8Insn, Address,
857                                this, STI);
858     if (Result != MCDisassembler::Fail) {
859       Size = 4;
860       return Result;
861     }
862   }
863 
864   Result =
865       decodeInstruction(DecoderTableThumb2CoProc32, MI, Insn32, Address, this, STI);
866   if (Result != MCDisassembler::Fail) {
867     Size = 4;
868     Check(Result, AddThumbPredicate(MI));
869     return Result;
870   }
871 
872   Size = 0;
873   return MCDisassembler::Fail;
874 }
875 
876 extern "C" void LLVMInitializeARMDisassembler() {
877   TargetRegistry::RegisterMCDisassembler(getTheARMLETarget(),
878                                          createARMDisassembler);
879   TargetRegistry::RegisterMCDisassembler(getTheARMBETarget(),
880                                          createARMDisassembler);
881   TargetRegistry::RegisterMCDisassembler(getTheThumbLETarget(),
882                                          createThumbDisassembler);
883   TargetRegistry::RegisterMCDisassembler(getTheThumbBETarget(),
884                                          createThumbDisassembler);
885 }
886 
887 static const uint16_t GPRDecoderTable[] = {
888   ARM::R0, ARM::R1, ARM::R2, ARM::R3,
889   ARM::R4, ARM::R5, ARM::R6, ARM::R7,
890   ARM::R8, ARM::R9, ARM::R10, ARM::R11,
891   ARM::R12, ARM::SP, ARM::LR, ARM::PC
892 };
893 
894 static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, unsigned RegNo,
895                                    uint64_t Address, const void *Decoder) {
896   if (RegNo > 15)
897     return MCDisassembler::Fail;
898 
899   unsigned Register = GPRDecoderTable[RegNo];
900   Inst.addOperand(MCOperand::createReg(Register));
901   return MCDisassembler::Success;
902 }
903 
904 static DecodeStatus
905 DecodeGPRnopcRegisterClass(MCInst &Inst, unsigned RegNo,
906                            uint64_t Address, const void *Decoder) {
907   DecodeStatus S = MCDisassembler::Success;
908 
909   if (RegNo == 15)
910     S = MCDisassembler::SoftFail;
911 
912   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
913 
914   return S;
915 }
916 
917 static DecodeStatus
918 DecodeGPRwithAPSRRegisterClass(MCInst &Inst, unsigned RegNo,
919                                uint64_t Address, const void *Decoder) {
920   DecodeStatus S = MCDisassembler::Success;
921 
922   if (RegNo == 15)
923   {
924     Inst.addOperand(MCOperand::createReg(ARM::APSR_NZCV));
925     return MCDisassembler::Success;
926   }
927 
928   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
929   return S;
930 }
931 
932 static DecodeStatus DecodetGPRRegisterClass(MCInst &Inst, unsigned RegNo,
933                                    uint64_t Address, const void *Decoder) {
934   if (RegNo > 7)
935     return MCDisassembler::Fail;
936   return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
937 }
938 
939 static const uint16_t GPRPairDecoderTable[] = {
940   ARM::R0_R1, ARM::R2_R3,   ARM::R4_R5,  ARM::R6_R7,
941   ARM::R8_R9, ARM::R10_R11, ARM::R12_SP
942 };
943 
944 static DecodeStatus DecodeGPRPairRegisterClass(MCInst &Inst, unsigned RegNo,
945                                    uint64_t Address, const void *Decoder) {
946   DecodeStatus S = MCDisassembler::Success;
947 
948   if (RegNo > 13)
949     return MCDisassembler::Fail;
950 
951   if ((RegNo & 1) || RegNo == 0xe)
952      S = MCDisassembler::SoftFail;
953 
954   unsigned RegisterPair = GPRPairDecoderTable[RegNo/2];
955   Inst.addOperand(MCOperand::createReg(RegisterPair));
956   return S;
957 }
958 
959 static DecodeStatus DecodetcGPRRegisterClass(MCInst &Inst, unsigned RegNo,
960                                    uint64_t Address, const void *Decoder) {
961   unsigned Register = 0;
962   switch (RegNo) {
963     case 0:
964       Register = ARM::R0;
965       break;
966     case 1:
967       Register = ARM::R1;
968       break;
969     case 2:
970       Register = ARM::R2;
971       break;
972     case 3:
973       Register = ARM::R3;
974       break;
975     case 9:
976       Register = ARM::R9;
977       break;
978     case 12:
979       Register = ARM::R12;
980       break;
981     default:
982       return MCDisassembler::Fail;
983     }
984 
985   Inst.addOperand(MCOperand::createReg(Register));
986   return MCDisassembler::Success;
987 }
988 
989 static DecodeStatus DecoderGPRRegisterClass(MCInst &Inst, unsigned RegNo,
990                                    uint64_t Address, const void *Decoder) {
991   DecodeStatus S = MCDisassembler::Success;
992 
993   const FeatureBitset &featureBits =
994     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
995 
996   if ((RegNo == 13 && !featureBits[ARM::HasV8Ops]) || RegNo == 15)
997     S = MCDisassembler::SoftFail;
998 
999   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1000   return S;
1001 }
1002 
1003 static const uint16_t SPRDecoderTable[] = {
1004      ARM::S0,  ARM::S1,  ARM::S2,  ARM::S3,
1005      ARM::S4,  ARM::S5,  ARM::S6,  ARM::S7,
1006      ARM::S8,  ARM::S9, ARM::S10, ARM::S11,
1007     ARM::S12, ARM::S13, ARM::S14, ARM::S15,
1008     ARM::S16, ARM::S17, ARM::S18, ARM::S19,
1009     ARM::S20, ARM::S21, ARM::S22, ARM::S23,
1010     ARM::S24, ARM::S25, ARM::S26, ARM::S27,
1011     ARM::S28, ARM::S29, ARM::S30, ARM::S31
1012 };
1013 
1014 static DecodeStatus DecodeSPRRegisterClass(MCInst &Inst, unsigned RegNo,
1015                                    uint64_t Address, const void *Decoder) {
1016   if (RegNo > 31)
1017     return MCDisassembler::Fail;
1018 
1019   unsigned Register = SPRDecoderTable[RegNo];
1020   Inst.addOperand(MCOperand::createReg(Register));
1021   return MCDisassembler::Success;
1022 }
1023 
1024 static DecodeStatus DecodeHPRRegisterClass(MCInst &Inst, unsigned RegNo,
1025                                    uint64_t Address, const void *Decoder) {
1026   return DecodeSPRRegisterClass(Inst, RegNo, Address, Decoder);
1027 }
1028 
1029 static const uint16_t DPRDecoderTable[] = {
1030      ARM::D0,  ARM::D1,  ARM::D2,  ARM::D3,
1031      ARM::D4,  ARM::D5,  ARM::D6,  ARM::D7,
1032      ARM::D8,  ARM::D9, ARM::D10, ARM::D11,
1033     ARM::D12, ARM::D13, ARM::D14, ARM::D15,
1034     ARM::D16, ARM::D17, ARM::D18, ARM::D19,
1035     ARM::D20, ARM::D21, ARM::D22, ARM::D23,
1036     ARM::D24, ARM::D25, ARM::D26, ARM::D27,
1037     ARM::D28, ARM::D29, ARM::D30, ARM::D31
1038 };
1039 
1040 static DecodeStatus DecodeDPRRegisterClass(MCInst &Inst, unsigned RegNo,
1041                                    uint64_t Address, const void *Decoder) {
1042   const FeatureBitset &featureBits =
1043     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1044 
1045   bool hasD16 = featureBits[ARM::FeatureD16];
1046 
1047   if (RegNo > 31 || (hasD16 && RegNo > 15))
1048     return MCDisassembler::Fail;
1049 
1050   unsigned Register = DPRDecoderTable[RegNo];
1051   Inst.addOperand(MCOperand::createReg(Register));
1052   return MCDisassembler::Success;
1053 }
1054 
1055 static DecodeStatus DecodeDPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
1056                                    uint64_t Address, const void *Decoder) {
1057   if (RegNo > 7)
1058     return MCDisassembler::Fail;
1059   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
1060 }
1061 
1062 static DecodeStatus DecodeSPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
1063                                    uint64_t Address, const void *Decoder) {
1064   if (RegNo > 15)
1065     return MCDisassembler::Fail;
1066   return DecodeSPRRegisterClass(Inst, RegNo, Address, Decoder);
1067 }
1068 
1069 static DecodeStatus
1070 DecodeDPR_VFP2RegisterClass(MCInst &Inst, unsigned RegNo,
1071                             uint64_t Address, const void *Decoder) {
1072   if (RegNo > 15)
1073     return MCDisassembler::Fail;
1074   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
1075 }
1076 
1077 static const uint16_t QPRDecoderTable[] = {
1078      ARM::Q0,  ARM::Q1,  ARM::Q2,  ARM::Q3,
1079      ARM::Q4,  ARM::Q5,  ARM::Q6,  ARM::Q7,
1080      ARM::Q8,  ARM::Q9, ARM::Q10, ARM::Q11,
1081     ARM::Q12, ARM::Q13, ARM::Q14, ARM::Q15
1082 };
1083 
1084 static DecodeStatus DecodeQPRRegisterClass(MCInst &Inst, unsigned RegNo,
1085                                    uint64_t Address, const void *Decoder) {
1086   if (RegNo > 31 || (RegNo & 1) != 0)
1087     return MCDisassembler::Fail;
1088   RegNo >>= 1;
1089 
1090   unsigned Register = QPRDecoderTable[RegNo];
1091   Inst.addOperand(MCOperand::createReg(Register));
1092   return MCDisassembler::Success;
1093 }
1094 
1095 static const uint16_t DPairDecoderTable[] = {
1096   ARM::Q0,  ARM::D1_D2,   ARM::Q1,  ARM::D3_D4,   ARM::Q2,  ARM::D5_D6,
1097   ARM::Q3,  ARM::D7_D8,   ARM::Q4,  ARM::D9_D10,  ARM::Q5,  ARM::D11_D12,
1098   ARM::Q6,  ARM::D13_D14, ARM::Q7,  ARM::D15_D16, ARM::Q8,  ARM::D17_D18,
1099   ARM::Q9,  ARM::D19_D20, ARM::Q10, ARM::D21_D22, ARM::Q11, ARM::D23_D24,
1100   ARM::Q12, ARM::D25_D26, ARM::Q13, ARM::D27_D28, ARM::Q14, ARM::D29_D30,
1101   ARM::Q15
1102 };
1103 
1104 static DecodeStatus DecodeDPairRegisterClass(MCInst &Inst, unsigned RegNo,
1105                                    uint64_t Address, const void *Decoder) {
1106   if (RegNo > 30)
1107     return MCDisassembler::Fail;
1108 
1109   unsigned Register = DPairDecoderTable[RegNo];
1110   Inst.addOperand(MCOperand::createReg(Register));
1111   return MCDisassembler::Success;
1112 }
1113 
1114 static const uint16_t DPairSpacedDecoderTable[] = {
1115   ARM::D0_D2,   ARM::D1_D3,   ARM::D2_D4,   ARM::D3_D5,
1116   ARM::D4_D6,   ARM::D5_D7,   ARM::D6_D8,   ARM::D7_D9,
1117   ARM::D8_D10,  ARM::D9_D11,  ARM::D10_D12, ARM::D11_D13,
1118   ARM::D12_D14, ARM::D13_D15, ARM::D14_D16, ARM::D15_D17,
1119   ARM::D16_D18, ARM::D17_D19, ARM::D18_D20, ARM::D19_D21,
1120   ARM::D20_D22, ARM::D21_D23, ARM::D22_D24, ARM::D23_D25,
1121   ARM::D24_D26, ARM::D25_D27, ARM::D26_D28, ARM::D27_D29,
1122   ARM::D28_D30, ARM::D29_D31
1123 };
1124 
1125 static DecodeStatus DecodeDPairSpacedRegisterClass(MCInst &Inst,
1126                                                    unsigned RegNo,
1127                                                    uint64_t Address,
1128                                                    const void *Decoder) {
1129   if (RegNo > 29)
1130     return MCDisassembler::Fail;
1131 
1132   unsigned Register = DPairSpacedDecoderTable[RegNo];
1133   Inst.addOperand(MCOperand::createReg(Register));
1134   return MCDisassembler::Success;
1135 }
1136 
1137 static DecodeStatus DecodePredicateOperand(MCInst &Inst, unsigned Val,
1138                                uint64_t Address, const void *Decoder) {
1139   DecodeStatus S = MCDisassembler::Success;
1140   if (Val == 0xF) return MCDisassembler::Fail;
1141   // AL predicate is not allowed on Thumb1 branches.
1142   if (Inst.getOpcode() == ARM::tBcc && Val == 0xE)
1143     return MCDisassembler::Fail;
1144   if (Val != ARMCC::AL && !ARMInsts[Inst.getOpcode()].isPredicable())
1145     Check(S, MCDisassembler::SoftFail);
1146   Inst.addOperand(MCOperand::createImm(Val));
1147   if (Val == ARMCC::AL) {
1148     Inst.addOperand(MCOperand::createReg(0));
1149   } else
1150     Inst.addOperand(MCOperand::createReg(ARM::CPSR));
1151   return S;
1152 }
1153 
1154 static DecodeStatus DecodeCCOutOperand(MCInst &Inst, unsigned Val,
1155                                uint64_t Address, const void *Decoder) {
1156   if (Val)
1157     Inst.addOperand(MCOperand::createReg(ARM::CPSR));
1158   else
1159     Inst.addOperand(MCOperand::createReg(0));
1160   return MCDisassembler::Success;
1161 }
1162 
1163 static DecodeStatus DecodeSORegImmOperand(MCInst &Inst, unsigned Val,
1164                                uint64_t Address, const void *Decoder) {
1165   DecodeStatus S = MCDisassembler::Success;
1166 
1167   unsigned Rm = fieldFromInstruction(Val, 0, 4);
1168   unsigned type = fieldFromInstruction(Val, 5, 2);
1169   unsigned imm = fieldFromInstruction(Val, 7, 5);
1170 
1171   // Register-immediate
1172   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
1173     return MCDisassembler::Fail;
1174 
1175   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1176   switch (type) {
1177     case 0:
1178       Shift = ARM_AM::lsl;
1179       break;
1180     case 1:
1181       Shift = ARM_AM::lsr;
1182       break;
1183     case 2:
1184       Shift = ARM_AM::asr;
1185       break;
1186     case 3:
1187       Shift = ARM_AM::ror;
1188       break;
1189   }
1190 
1191   if (Shift == ARM_AM::ror && imm == 0)
1192     Shift = ARM_AM::rrx;
1193 
1194   unsigned Op = Shift | (imm << 3);
1195   Inst.addOperand(MCOperand::createImm(Op));
1196 
1197   return S;
1198 }
1199 
1200 static DecodeStatus DecodeSORegRegOperand(MCInst &Inst, unsigned Val,
1201                                uint64_t Address, const void *Decoder) {
1202   DecodeStatus S = MCDisassembler::Success;
1203 
1204   unsigned Rm = fieldFromInstruction(Val, 0, 4);
1205   unsigned type = fieldFromInstruction(Val, 5, 2);
1206   unsigned Rs = fieldFromInstruction(Val, 8, 4);
1207 
1208   // Register-register
1209   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1210     return MCDisassembler::Fail;
1211   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rs, Address, Decoder)))
1212     return MCDisassembler::Fail;
1213 
1214   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1215   switch (type) {
1216     case 0:
1217       Shift = ARM_AM::lsl;
1218       break;
1219     case 1:
1220       Shift = ARM_AM::lsr;
1221       break;
1222     case 2:
1223       Shift = ARM_AM::asr;
1224       break;
1225     case 3:
1226       Shift = ARM_AM::ror;
1227       break;
1228   }
1229 
1230   Inst.addOperand(MCOperand::createImm(Shift));
1231 
1232   return S;
1233 }
1234 
1235 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Val,
1236                                  uint64_t Address, const void *Decoder) {
1237   DecodeStatus S = MCDisassembler::Success;
1238 
1239   bool NeedDisjointWriteback = false;
1240   unsigned WritebackReg = 0;
1241   switch (Inst.getOpcode()) {
1242   default:
1243     break;
1244   case ARM::LDMIA_UPD:
1245   case ARM::LDMDB_UPD:
1246   case ARM::LDMIB_UPD:
1247   case ARM::LDMDA_UPD:
1248   case ARM::t2LDMIA_UPD:
1249   case ARM::t2LDMDB_UPD:
1250   case ARM::t2STMIA_UPD:
1251   case ARM::t2STMDB_UPD:
1252     NeedDisjointWriteback = true;
1253     WritebackReg = Inst.getOperand(0).getReg();
1254     break;
1255   }
1256 
1257   // Empty register lists are not allowed.
1258   if (Val == 0) return MCDisassembler::Fail;
1259   for (unsigned i = 0; i < 16; ++i) {
1260     if (Val & (1 << i)) {
1261       if (!Check(S, DecodeGPRRegisterClass(Inst, i, Address, Decoder)))
1262         return MCDisassembler::Fail;
1263       // Writeback not allowed if Rn is in the target list.
1264       if (NeedDisjointWriteback && WritebackReg == Inst.end()[-1].getReg())
1265         Check(S, MCDisassembler::SoftFail);
1266     }
1267   }
1268 
1269   return S;
1270 }
1271 
1272 static DecodeStatus DecodeSPRRegListOperand(MCInst &Inst, unsigned Val,
1273                                  uint64_t Address, const void *Decoder) {
1274   DecodeStatus S = MCDisassembler::Success;
1275 
1276   unsigned Vd = fieldFromInstruction(Val, 8, 5);
1277   unsigned regs = fieldFromInstruction(Val, 0, 8);
1278 
1279   // In case of unpredictable encoding, tweak the operands.
1280   if (regs == 0 || (Vd + regs) > 32) {
1281     regs = Vd + regs > 32 ? 32 - Vd : regs;
1282     regs = std::max( 1u, regs);
1283     S = MCDisassembler::SoftFail;
1284   }
1285 
1286   if (!Check(S, DecodeSPRRegisterClass(Inst, Vd, Address, Decoder)))
1287     return MCDisassembler::Fail;
1288   for (unsigned i = 0; i < (regs - 1); ++i) {
1289     if (!Check(S, DecodeSPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1290       return MCDisassembler::Fail;
1291   }
1292 
1293   return S;
1294 }
1295 
1296 static DecodeStatus DecodeDPRRegListOperand(MCInst &Inst, unsigned Val,
1297                                  uint64_t Address, const void *Decoder) {
1298   DecodeStatus S = MCDisassembler::Success;
1299 
1300   unsigned Vd = fieldFromInstruction(Val, 8, 5);
1301   unsigned regs = fieldFromInstruction(Val, 1, 7);
1302 
1303   // In case of unpredictable encoding, tweak the operands.
1304   if (regs == 0 || regs > 16 || (Vd + regs) > 32) {
1305     regs = Vd + regs > 32 ? 32 - Vd : regs;
1306     regs = std::max( 1u, regs);
1307     regs = std::min(16u, regs);
1308     S = MCDisassembler::SoftFail;
1309   }
1310 
1311   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
1312       return MCDisassembler::Fail;
1313   for (unsigned i = 0; i < (regs - 1); ++i) {
1314     if (!Check(S, DecodeDPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1315       return MCDisassembler::Fail;
1316   }
1317 
1318   return S;
1319 }
1320 
1321 static DecodeStatus DecodeBitfieldMaskOperand(MCInst &Inst, unsigned Val,
1322                                       uint64_t Address, const void *Decoder) {
1323   // This operand encodes a mask of contiguous zeros between a specified MSB
1324   // and LSB.  To decode it, we create the mask of all bits MSB-and-lower,
1325   // the mask of all bits LSB-and-lower, and then xor them to create
1326   // the mask of that's all ones on [msb, lsb].  Finally we not it to
1327   // create the final mask.
1328   unsigned msb = fieldFromInstruction(Val, 5, 5);
1329   unsigned lsb = fieldFromInstruction(Val, 0, 5);
1330 
1331   DecodeStatus S = MCDisassembler::Success;
1332   if (lsb > msb) {
1333     Check(S, MCDisassembler::SoftFail);
1334     // The check above will cause the warning for the "potentially undefined
1335     // instruction encoding" but we can't build a bad MCOperand value here
1336     // with a lsb > msb or else printing the MCInst will cause a crash.
1337     lsb = msb;
1338   }
1339 
1340   uint32_t msb_mask = 0xFFFFFFFF;
1341   if (msb != 31) msb_mask = (1U << (msb+1)) - 1;
1342   uint32_t lsb_mask = (1U << lsb) - 1;
1343 
1344   Inst.addOperand(MCOperand::createImm(~(msb_mask ^ lsb_mask)));
1345   return S;
1346 }
1347 
1348 static DecodeStatus DecodeCopMemInstruction(MCInst &Inst, unsigned Insn,
1349                                   uint64_t Address, const void *Decoder) {
1350   DecodeStatus S = MCDisassembler::Success;
1351 
1352   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1353   unsigned CRd = fieldFromInstruction(Insn, 12, 4);
1354   unsigned coproc = fieldFromInstruction(Insn, 8, 4);
1355   unsigned imm = fieldFromInstruction(Insn, 0, 8);
1356   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1357   unsigned U = fieldFromInstruction(Insn, 23, 1);
1358 
1359   switch (Inst.getOpcode()) {
1360     case ARM::LDC_OFFSET:
1361     case ARM::LDC_PRE:
1362     case ARM::LDC_POST:
1363     case ARM::LDC_OPTION:
1364     case ARM::LDCL_OFFSET:
1365     case ARM::LDCL_PRE:
1366     case ARM::LDCL_POST:
1367     case ARM::LDCL_OPTION:
1368     case ARM::STC_OFFSET:
1369     case ARM::STC_PRE:
1370     case ARM::STC_POST:
1371     case ARM::STC_OPTION:
1372     case ARM::STCL_OFFSET:
1373     case ARM::STCL_PRE:
1374     case ARM::STCL_POST:
1375     case ARM::STCL_OPTION:
1376     case ARM::t2LDC_OFFSET:
1377     case ARM::t2LDC_PRE:
1378     case ARM::t2LDC_POST:
1379     case ARM::t2LDC_OPTION:
1380     case ARM::t2LDCL_OFFSET:
1381     case ARM::t2LDCL_PRE:
1382     case ARM::t2LDCL_POST:
1383     case ARM::t2LDCL_OPTION:
1384     case ARM::t2STC_OFFSET:
1385     case ARM::t2STC_PRE:
1386     case ARM::t2STC_POST:
1387     case ARM::t2STC_OPTION:
1388     case ARM::t2STCL_OFFSET:
1389     case ARM::t2STCL_PRE:
1390     case ARM::t2STCL_POST:
1391     case ARM::t2STCL_OPTION:
1392       if (coproc == 0xA || coproc == 0xB)
1393         return MCDisassembler::Fail;
1394       break;
1395     default:
1396       break;
1397   }
1398 
1399   const FeatureBitset &featureBits =
1400     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1401   if (featureBits[ARM::HasV8Ops] && (coproc != 14))
1402     return MCDisassembler::Fail;
1403 
1404   Inst.addOperand(MCOperand::createImm(coproc));
1405   Inst.addOperand(MCOperand::createImm(CRd));
1406   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1407     return MCDisassembler::Fail;
1408 
1409   switch (Inst.getOpcode()) {
1410     case ARM::t2LDC2_OFFSET:
1411     case ARM::t2LDC2L_OFFSET:
1412     case ARM::t2LDC2_PRE:
1413     case ARM::t2LDC2L_PRE:
1414     case ARM::t2STC2_OFFSET:
1415     case ARM::t2STC2L_OFFSET:
1416     case ARM::t2STC2_PRE:
1417     case ARM::t2STC2L_PRE:
1418     case ARM::LDC2_OFFSET:
1419     case ARM::LDC2L_OFFSET:
1420     case ARM::LDC2_PRE:
1421     case ARM::LDC2L_PRE:
1422     case ARM::STC2_OFFSET:
1423     case ARM::STC2L_OFFSET:
1424     case ARM::STC2_PRE:
1425     case ARM::STC2L_PRE:
1426     case ARM::t2LDC_OFFSET:
1427     case ARM::t2LDCL_OFFSET:
1428     case ARM::t2LDC_PRE:
1429     case ARM::t2LDCL_PRE:
1430     case ARM::t2STC_OFFSET:
1431     case ARM::t2STCL_OFFSET:
1432     case ARM::t2STC_PRE:
1433     case ARM::t2STCL_PRE:
1434     case ARM::LDC_OFFSET:
1435     case ARM::LDCL_OFFSET:
1436     case ARM::LDC_PRE:
1437     case ARM::LDCL_PRE:
1438     case ARM::STC_OFFSET:
1439     case ARM::STCL_OFFSET:
1440     case ARM::STC_PRE:
1441     case ARM::STCL_PRE:
1442       imm = ARM_AM::getAM5Opc(U ? ARM_AM::add : ARM_AM::sub, imm);
1443       Inst.addOperand(MCOperand::createImm(imm));
1444       break;
1445     case ARM::t2LDC2_POST:
1446     case ARM::t2LDC2L_POST:
1447     case ARM::t2STC2_POST:
1448     case ARM::t2STC2L_POST:
1449     case ARM::LDC2_POST:
1450     case ARM::LDC2L_POST:
1451     case ARM::STC2_POST:
1452     case ARM::STC2L_POST:
1453     case ARM::t2LDC_POST:
1454     case ARM::t2LDCL_POST:
1455     case ARM::t2STC_POST:
1456     case ARM::t2STCL_POST:
1457     case ARM::LDC_POST:
1458     case ARM::LDCL_POST:
1459     case ARM::STC_POST:
1460     case ARM::STCL_POST:
1461       imm |= U << 8;
1462       LLVM_FALLTHROUGH;
1463     default:
1464       // The 'option' variant doesn't encode 'U' in the immediate since
1465       // the immediate is unsigned [0,255].
1466       Inst.addOperand(MCOperand::createImm(imm));
1467       break;
1468   }
1469 
1470   switch (Inst.getOpcode()) {
1471     case ARM::LDC_OFFSET:
1472     case ARM::LDC_PRE:
1473     case ARM::LDC_POST:
1474     case ARM::LDC_OPTION:
1475     case ARM::LDCL_OFFSET:
1476     case ARM::LDCL_PRE:
1477     case ARM::LDCL_POST:
1478     case ARM::LDCL_OPTION:
1479     case ARM::STC_OFFSET:
1480     case ARM::STC_PRE:
1481     case ARM::STC_POST:
1482     case ARM::STC_OPTION:
1483     case ARM::STCL_OFFSET:
1484     case ARM::STCL_PRE:
1485     case ARM::STCL_POST:
1486     case ARM::STCL_OPTION:
1487       if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1488         return MCDisassembler::Fail;
1489       break;
1490     default:
1491       break;
1492   }
1493 
1494   return S;
1495 }
1496 
1497 static DecodeStatus
1498 DecodeAddrMode2IdxInstruction(MCInst &Inst, unsigned Insn,
1499                               uint64_t Address, const void *Decoder) {
1500   DecodeStatus S = MCDisassembler::Success;
1501 
1502   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1503   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
1504   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
1505   unsigned imm = fieldFromInstruction(Insn, 0, 12);
1506   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1507   unsigned reg = fieldFromInstruction(Insn, 25, 1);
1508   unsigned P = fieldFromInstruction(Insn, 24, 1);
1509   unsigned W = fieldFromInstruction(Insn, 21, 1);
1510 
1511   // On stores, the writeback operand precedes Rt.
1512   switch (Inst.getOpcode()) {
1513     case ARM::STR_POST_IMM:
1514     case ARM::STR_POST_REG:
1515     case ARM::STRB_POST_IMM:
1516     case ARM::STRB_POST_REG:
1517     case ARM::STRT_POST_REG:
1518     case ARM::STRT_POST_IMM:
1519     case ARM::STRBT_POST_REG:
1520     case ARM::STRBT_POST_IMM:
1521       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1522         return MCDisassembler::Fail;
1523       break;
1524     default:
1525       break;
1526   }
1527 
1528   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
1529     return MCDisassembler::Fail;
1530 
1531   // On loads, the writeback operand comes after Rt.
1532   switch (Inst.getOpcode()) {
1533     case ARM::LDR_POST_IMM:
1534     case ARM::LDR_POST_REG:
1535     case ARM::LDRB_POST_IMM:
1536     case ARM::LDRB_POST_REG:
1537     case ARM::LDRBT_POST_REG:
1538     case ARM::LDRBT_POST_IMM:
1539     case ARM::LDRT_POST_REG:
1540     case ARM::LDRT_POST_IMM:
1541       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1542         return MCDisassembler::Fail;
1543       break;
1544     default:
1545       break;
1546   }
1547 
1548   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1549     return MCDisassembler::Fail;
1550 
1551   ARM_AM::AddrOpc Op = ARM_AM::add;
1552   if (!fieldFromInstruction(Insn, 23, 1))
1553     Op = ARM_AM::sub;
1554 
1555   bool writeback = (P == 0) || (W == 1);
1556   unsigned idx_mode = 0;
1557   if (P && writeback)
1558     idx_mode = ARMII::IndexModePre;
1559   else if (!P && writeback)
1560     idx_mode = ARMII::IndexModePost;
1561 
1562   if (writeback && (Rn == 15 || Rn == Rt))
1563     S = MCDisassembler::SoftFail; // UNPREDICTABLE
1564 
1565   if (reg) {
1566     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1567       return MCDisassembler::Fail;
1568     ARM_AM::ShiftOpc Opc = ARM_AM::lsl;
1569     switch( fieldFromInstruction(Insn, 5, 2)) {
1570       case 0:
1571         Opc = ARM_AM::lsl;
1572         break;
1573       case 1:
1574         Opc = ARM_AM::lsr;
1575         break;
1576       case 2:
1577         Opc = ARM_AM::asr;
1578         break;
1579       case 3:
1580         Opc = ARM_AM::ror;
1581         break;
1582       default:
1583         return MCDisassembler::Fail;
1584     }
1585     unsigned amt = fieldFromInstruction(Insn, 7, 5);
1586     if (Opc == ARM_AM::ror && amt == 0)
1587       Opc = ARM_AM::rrx;
1588     unsigned imm = ARM_AM::getAM2Opc(Op, amt, Opc, idx_mode);
1589 
1590     Inst.addOperand(MCOperand::createImm(imm));
1591   } else {
1592     Inst.addOperand(MCOperand::createReg(0));
1593     unsigned tmp = ARM_AM::getAM2Opc(Op, imm, ARM_AM::lsl, idx_mode);
1594     Inst.addOperand(MCOperand::createImm(tmp));
1595   }
1596 
1597   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1598     return MCDisassembler::Fail;
1599 
1600   return S;
1601 }
1602 
1603 static DecodeStatus DecodeSORegMemOperand(MCInst &Inst, unsigned Val,
1604                                   uint64_t Address, const void *Decoder) {
1605   DecodeStatus S = MCDisassembler::Success;
1606 
1607   unsigned Rn = fieldFromInstruction(Val, 13, 4);
1608   unsigned Rm = fieldFromInstruction(Val,  0, 4);
1609   unsigned type = fieldFromInstruction(Val, 5, 2);
1610   unsigned imm = fieldFromInstruction(Val, 7, 5);
1611   unsigned U = fieldFromInstruction(Val, 12, 1);
1612 
1613   ARM_AM::ShiftOpc ShOp = ARM_AM::lsl;
1614   switch (type) {
1615     case 0:
1616       ShOp = ARM_AM::lsl;
1617       break;
1618     case 1:
1619       ShOp = ARM_AM::lsr;
1620       break;
1621     case 2:
1622       ShOp = ARM_AM::asr;
1623       break;
1624     case 3:
1625       ShOp = ARM_AM::ror;
1626       break;
1627   }
1628 
1629   if (ShOp == ARM_AM::ror && imm == 0)
1630     ShOp = ARM_AM::rrx;
1631 
1632   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1633     return MCDisassembler::Fail;
1634   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1635     return MCDisassembler::Fail;
1636   unsigned shift;
1637   if (U)
1638     shift = ARM_AM::getAM2Opc(ARM_AM::add, imm, ShOp);
1639   else
1640     shift = ARM_AM::getAM2Opc(ARM_AM::sub, imm, ShOp);
1641   Inst.addOperand(MCOperand::createImm(shift));
1642 
1643   return S;
1644 }
1645 
1646 static DecodeStatus
1647 DecodeAddrMode3Instruction(MCInst &Inst, unsigned Insn,
1648                            uint64_t Address, const void *Decoder) {
1649   DecodeStatus S = MCDisassembler::Success;
1650 
1651   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
1652   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1653   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
1654   unsigned type = fieldFromInstruction(Insn, 22, 1);
1655   unsigned imm = fieldFromInstruction(Insn, 8, 4);
1656   unsigned U = ((~fieldFromInstruction(Insn, 23, 1)) & 1) << 8;
1657   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1658   unsigned W = fieldFromInstruction(Insn, 21, 1);
1659   unsigned P = fieldFromInstruction(Insn, 24, 1);
1660   unsigned Rt2 = Rt + 1;
1661 
1662   bool writeback = (W == 1) | (P == 0);
1663 
1664   // For {LD,ST}RD, Rt must be even, else undefined.
1665   switch (Inst.getOpcode()) {
1666     case ARM::STRD:
1667     case ARM::STRD_PRE:
1668     case ARM::STRD_POST:
1669     case ARM::LDRD:
1670     case ARM::LDRD_PRE:
1671     case ARM::LDRD_POST:
1672       if (Rt & 0x1) S = MCDisassembler::SoftFail;
1673       break;
1674     default:
1675       break;
1676   }
1677   switch (Inst.getOpcode()) {
1678     case ARM::STRD:
1679     case ARM::STRD_PRE:
1680     case ARM::STRD_POST:
1681       if (P == 0 && W == 1)
1682         S = MCDisassembler::SoftFail;
1683 
1684       if (writeback && (Rn == 15 || Rn == Rt || Rn == Rt2))
1685         S = MCDisassembler::SoftFail;
1686       if (type && Rm == 15)
1687         S = MCDisassembler::SoftFail;
1688       if (Rt2 == 15)
1689         S = MCDisassembler::SoftFail;
1690       if (!type && fieldFromInstruction(Insn, 8, 4))
1691         S = MCDisassembler::SoftFail;
1692       break;
1693     case ARM::STRH:
1694     case ARM::STRH_PRE:
1695     case ARM::STRH_POST:
1696       if (Rt == 15)
1697         S = MCDisassembler::SoftFail;
1698       if (writeback && (Rn == 15 || Rn == Rt))
1699         S = MCDisassembler::SoftFail;
1700       if (!type && Rm == 15)
1701         S = MCDisassembler::SoftFail;
1702       break;
1703     case ARM::LDRD:
1704     case ARM::LDRD_PRE:
1705     case ARM::LDRD_POST:
1706       if (type && Rn == 15) {
1707         if (Rt2 == 15)
1708           S = MCDisassembler::SoftFail;
1709         break;
1710       }
1711       if (P == 0 && W == 1)
1712         S = MCDisassembler::SoftFail;
1713       if (!type && (Rt2 == 15 || Rm == 15 || Rm == Rt || Rm == Rt2))
1714         S = MCDisassembler::SoftFail;
1715       if (!type && writeback && Rn == 15)
1716         S = MCDisassembler::SoftFail;
1717       if (writeback && (Rn == Rt || Rn == Rt2))
1718         S = MCDisassembler::SoftFail;
1719       break;
1720     case ARM::LDRH:
1721     case ARM::LDRH_PRE:
1722     case ARM::LDRH_POST:
1723       if (type && Rn == 15) {
1724         if (Rt == 15)
1725           S = MCDisassembler::SoftFail;
1726         break;
1727       }
1728       if (Rt == 15)
1729         S = MCDisassembler::SoftFail;
1730       if (!type && Rm == 15)
1731         S = MCDisassembler::SoftFail;
1732       if (!type && writeback && (Rn == 15 || Rn == Rt))
1733         S = MCDisassembler::SoftFail;
1734       break;
1735     case ARM::LDRSH:
1736     case ARM::LDRSH_PRE:
1737     case ARM::LDRSH_POST:
1738     case ARM::LDRSB:
1739     case ARM::LDRSB_PRE:
1740     case ARM::LDRSB_POST:
1741       if (type && Rn == 15) {
1742         if (Rt == 15)
1743           S = MCDisassembler::SoftFail;
1744         break;
1745       }
1746       if (type && (Rt == 15 || (writeback && Rn == Rt)))
1747         S = MCDisassembler::SoftFail;
1748       if (!type && (Rt == 15 || Rm == 15))
1749         S = MCDisassembler::SoftFail;
1750       if (!type && writeback && (Rn == 15 || Rn == Rt))
1751         S = MCDisassembler::SoftFail;
1752       break;
1753     default:
1754       break;
1755   }
1756 
1757   if (writeback) { // Writeback
1758     if (P)
1759       U |= ARMII::IndexModePre << 9;
1760     else
1761       U |= ARMII::IndexModePost << 9;
1762 
1763     // On stores, the writeback operand precedes Rt.
1764     switch (Inst.getOpcode()) {
1765     case ARM::STRD:
1766     case ARM::STRD_PRE:
1767     case ARM::STRD_POST:
1768     case ARM::STRH:
1769     case ARM::STRH_PRE:
1770     case ARM::STRH_POST:
1771       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1772         return MCDisassembler::Fail;
1773       break;
1774     default:
1775       break;
1776     }
1777   }
1778 
1779   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
1780     return MCDisassembler::Fail;
1781   switch (Inst.getOpcode()) {
1782     case ARM::STRD:
1783     case ARM::STRD_PRE:
1784     case ARM::STRD_POST:
1785     case ARM::LDRD:
1786     case ARM::LDRD_PRE:
1787     case ARM::LDRD_POST:
1788       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder)))
1789         return MCDisassembler::Fail;
1790       break;
1791     default:
1792       break;
1793   }
1794 
1795   if (writeback) {
1796     // On loads, the writeback operand comes after Rt.
1797     switch (Inst.getOpcode()) {
1798     case ARM::LDRD:
1799     case ARM::LDRD_PRE:
1800     case ARM::LDRD_POST:
1801     case ARM::LDRH:
1802     case ARM::LDRH_PRE:
1803     case ARM::LDRH_POST:
1804     case ARM::LDRSH:
1805     case ARM::LDRSH_PRE:
1806     case ARM::LDRSH_POST:
1807     case ARM::LDRSB:
1808     case ARM::LDRSB_PRE:
1809     case ARM::LDRSB_POST:
1810     case ARM::LDRHTr:
1811     case ARM::LDRSBTr:
1812       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1813         return MCDisassembler::Fail;
1814       break;
1815     default:
1816       break;
1817     }
1818   }
1819 
1820   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1821     return MCDisassembler::Fail;
1822 
1823   if (type) {
1824     Inst.addOperand(MCOperand::createReg(0));
1825     Inst.addOperand(MCOperand::createImm(U | (imm << 4) | Rm));
1826   } else {
1827     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1828     return MCDisassembler::Fail;
1829     Inst.addOperand(MCOperand::createImm(U));
1830   }
1831 
1832   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1833     return MCDisassembler::Fail;
1834 
1835   return S;
1836 }
1837 
1838 static DecodeStatus DecodeRFEInstruction(MCInst &Inst, unsigned Insn,
1839                                  uint64_t Address, const void *Decoder) {
1840   DecodeStatus S = MCDisassembler::Success;
1841 
1842   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1843   unsigned mode = fieldFromInstruction(Insn, 23, 2);
1844 
1845   switch (mode) {
1846     case 0:
1847       mode = ARM_AM::da;
1848       break;
1849     case 1:
1850       mode = ARM_AM::ia;
1851       break;
1852     case 2:
1853       mode = ARM_AM::db;
1854       break;
1855     case 3:
1856       mode = ARM_AM::ib;
1857       break;
1858   }
1859 
1860   Inst.addOperand(MCOperand::createImm(mode));
1861   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1862     return MCDisassembler::Fail;
1863 
1864   return S;
1865 }
1866 
1867 static DecodeStatus DecodeQADDInstruction(MCInst &Inst, unsigned Insn,
1868                                uint64_t Address, const void *Decoder) {
1869   DecodeStatus S = MCDisassembler::Success;
1870 
1871   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
1872   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
1873   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1874   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1875 
1876   if (pred == 0xF)
1877     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
1878 
1879   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
1880     return MCDisassembler::Fail;
1881   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1882     return MCDisassembler::Fail;
1883   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
1884     return MCDisassembler::Fail;
1885   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1886     return MCDisassembler::Fail;
1887   return S;
1888 }
1889 
1890 static DecodeStatus DecodeMemMultipleWritebackInstruction(MCInst &Inst,
1891                                   unsigned Insn,
1892                                   uint64_t Address, const void *Decoder) {
1893   DecodeStatus S = MCDisassembler::Success;
1894 
1895   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1896   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1897   unsigned reglist = fieldFromInstruction(Insn, 0, 16);
1898 
1899   if (pred == 0xF) {
1900     // Ambiguous with RFE and SRS
1901     switch (Inst.getOpcode()) {
1902       case ARM::LDMDA:
1903         Inst.setOpcode(ARM::RFEDA);
1904         break;
1905       case ARM::LDMDA_UPD:
1906         Inst.setOpcode(ARM::RFEDA_UPD);
1907         break;
1908       case ARM::LDMDB:
1909         Inst.setOpcode(ARM::RFEDB);
1910         break;
1911       case ARM::LDMDB_UPD:
1912         Inst.setOpcode(ARM::RFEDB_UPD);
1913         break;
1914       case ARM::LDMIA:
1915         Inst.setOpcode(ARM::RFEIA);
1916         break;
1917       case ARM::LDMIA_UPD:
1918         Inst.setOpcode(ARM::RFEIA_UPD);
1919         break;
1920       case ARM::LDMIB:
1921         Inst.setOpcode(ARM::RFEIB);
1922         break;
1923       case ARM::LDMIB_UPD:
1924         Inst.setOpcode(ARM::RFEIB_UPD);
1925         break;
1926       case ARM::STMDA:
1927         Inst.setOpcode(ARM::SRSDA);
1928         break;
1929       case ARM::STMDA_UPD:
1930         Inst.setOpcode(ARM::SRSDA_UPD);
1931         break;
1932       case ARM::STMDB:
1933         Inst.setOpcode(ARM::SRSDB);
1934         break;
1935       case ARM::STMDB_UPD:
1936         Inst.setOpcode(ARM::SRSDB_UPD);
1937         break;
1938       case ARM::STMIA:
1939         Inst.setOpcode(ARM::SRSIA);
1940         break;
1941       case ARM::STMIA_UPD:
1942         Inst.setOpcode(ARM::SRSIA_UPD);
1943         break;
1944       case ARM::STMIB:
1945         Inst.setOpcode(ARM::SRSIB);
1946         break;
1947       case ARM::STMIB_UPD:
1948         Inst.setOpcode(ARM::SRSIB_UPD);
1949         break;
1950       default:
1951         return MCDisassembler::Fail;
1952     }
1953 
1954     // For stores (which become SRS's, the only operand is the mode.
1955     if (fieldFromInstruction(Insn, 20, 1) == 0) {
1956       // Check SRS encoding constraints
1957       if (!(fieldFromInstruction(Insn, 22, 1) == 1 &&
1958             fieldFromInstruction(Insn, 20, 1) == 0))
1959         return MCDisassembler::Fail;
1960 
1961       Inst.addOperand(
1962           MCOperand::createImm(fieldFromInstruction(Insn, 0, 4)));
1963       return S;
1964     }
1965 
1966     return DecodeRFEInstruction(Inst, Insn, Address, Decoder);
1967   }
1968 
1969   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1970     return MCDisassembler::Fail;
1971   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1972     return MCDisassembler::Fail; // Tied
1973   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1974     return MCDisassembler::Fail;
1975   if (!Check(S, DecodeRegListOperand(Inst, reglist, Address, Decoder)))
1976     return MCDisassembler::Fail;
1977 
1978   return S;
1979 }
1980 
1981 // Check for UNPREDICTABLE predicated ESB instruction
1982 static DecodeStatus DecodeHINTInstruction(MCInst &Inst, unsigned Insn,
1983                                  uint64_t Address, const void *Decoder) {
1984   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1985   unsigned imm8 = fieldFromInstruction(Insn, 0, 8);
1986   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
1987   const FeatureBitset &FeatureBits = Dis->getSubtargetInfo().getFeatureBits();
1988 
1989   DecodeStatus S = MCDisassembler::Success;
1990 
1991   Inst.addOperand(MCOperand::createImm(imm8));
1992 
1993   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1994     return MCDisassembler::Fail;
1995 
1996   // ESB is unpredictable if pred != AL. Without the RAS extension, it is a NOP,
1997   // so all predicates should be allowed.
1998   if (imm8 == 0x10 && pred != 0xe && ((FeatureBits[ARM::FeatureRAS]) != 0))
1999     S = MCDisassembler::SoftFail;
2000 
2001   return S;
2002 }
2003 
2004 static DecodeStatus DecodeCPSInstruction(MCInst &Inst, unsigned Insn,
2005                                  uint64_t Address, const void *Decoder) {
2006   unsigned imod = fieldFromInstruction(Insn, 18, 2);
2007   unsigned M = fieldFromInstruction(Insn, 17, 1);
2008   unsigned iflags = fieldFromInstruction(Insn, 6, 3);
2009   unsigned mode = fieldFromInstruction(Insn, 0, 5);
2010 
2011   DecodeStatus S = MCDisassembler::Success;
2012 
2013   // This decoder is called from multiple location that do not check
2014   // the full encoding is valid before they do.
2015   if (fieldFromInstruction(Insn, 5, 1) != 0 ||
2016       fieldFromInstruction(Insn, 16, 1) != 0 ||
2017       fieldFromInstruction(Insn, 20, 8) != 0x10)
2018     return MCDisassembler::Fail;
2019 
2020   // imod == '01' --> UNPREDICTABLE
2021   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
2022   // return failure here.  The '01' imod value is unprintable, so there's
2023   // nothing useful we could do even if we returned UNPREDICTABLE.
2024 
2025   if (imod == 1) return MCDisassembler::Fail;
2026 
2027   if (imod && M) {
2028     Inst.setOpcode(ARM::CPS3p);
2029     Inst.addOperand(MCOperand::createImm(imod));
2030     Inst.addOperand(MCOperand::createImm(iflags));
2031     Inst.addOperand(MCOperand::createImm(mode));
2032   } else if (imod && !M) {
2033     Inst.setOpcode(ARM::CPS2p);
2034     Inst.addOperand(MCOperand::createImm(imod));
2035     Inst.addOperand(MCOperand::createImm(iflags));
2036     if (mode) S = MCDisassembler::SoftFail;
2037   } else if (!imod && M) {
2038     Inst.setOpcode(ARM::CPS1p);
2039     Inst.addOperand(MCOperand::createImm(mode));
2040     if (iflags) S = MCDisassembler::SoftFail;
2041   } else {
2042     // imod == '00' && M == '0' --> UNPREDICTABLE
2043     Inst.setOpcode(ARM::CPS1p);
2044     Inst.addOperand(MCOperand::createImm(mode));
2045     S = MCDisassembler::SoftFail;
2046   }
2047 
2048   return S;
2049 }
2050 
2051 static DecodeStatus DecodeT2CPSInstruction(MCInst &Inst, unsigned Insn,
2052                                  uint64_t Address, const void *Decoder) {
2053   unsigned imod = fieldFromInstruction(Insn, 9, 2);
2054   unsigned M = fieldFromInstruction(Insn, 8, 1);
2055   unsigned iflags = fieldFromInstruction(Insn, 5, 3);
2056   unsigned mode = fieldFromInstruction(Insn, 0, 5);
2057 
2058   DecodeStatus S = MCDisassembler::Success;
2059 
2060   // imod == '01' --> UNPREDICTABLE
2061   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
2062   // return failure here.  The '01' imod value is unprintable, so there's
2063   // nothing useful we could do even if we returned UNPREDICTABLE.
2064 
2065   if (imod == 1) return MCDisassembler::Fail;
2066 
2067   if (imod && M) {
2068     Inst.setOpcode(ARM::t2CPS3p);
2069     Inst.addOperand(MCOperand::createImm(imod));
2070     Inst.addOperand(MCOperand::createImm(iflags));
2071     Inst.addOperand(MCOperand::createImm(mode));
2072   } else if (imod && !M) {
2073     Inst.setOpcode(ARM::t2CPS2p);
2074     Inst.addOperand(MCOperand::createImm(imod));
2075     Inst.addOperand(MCOperand::createImm(iflags));
2076     if (mode) S = MCDisassembler::SoftFail;
2077   } else if (!imod && M) {
2078     Inst.setOpcode(ARM::t2CPS1p);
2079     Inst.addOperand(MCOperand::createImm(mode));
2080     if (iflags) S = MCDisassembler::SoftFail;
2081   } else {
2082     // imod == '00' && M == '0' --> this is a HINT instruction
2083     int imm = fieldFromInstruction(Insn, 0, 8);
2084     // HINT are defined only for immediate in [0..4]
2085     if(imm > 4) return MCDisassembler::Fail;
2086     Inst.setOpcode(ARM::t2HINT);
2087     Inst.addOperand(MCOperand::createImm(imm));
2088   }
2089 
2090   return S;
2091 }
2092 
2093 static DecodeStatus DecodeT2MOVTWInstruction(MCInst &Inst, unsigned Insn,
2094                                  uint64_t Address, const void *Decoder) {
2095   DecodeStatus S = MCDisassembler::Success;
2096 
2097   unsigned Rd = fieldFromInstruction(Insn, 8, 4);
2098   unsigned imm = 0;
2099 
2100   imm |= (fieldFromInstruction(Insn, 0, 8) << 0);
2101   imm |= (fieldFromInstruction(Insn, 12, 3) << 8);
2102   imm |= (fieldFromInstruction(Insn, 16, 4) << 12);
2103   imm |= (fieldFromInstruction(Insn, 26, 1) << 11);
2104 
2105   if (Inst.getOpcode() == ARM::t2MOVTi16)
2106     if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
2107       return MCDisassembler::Fail;
2108   if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
2109     return MCDisassembler::Fail;
2110 
2111   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
2112     Inst.addOperand(MCOperand::createImm(imm));
2113 
2114   return S;
2115 }
2116 
2117 static DecodeStatus DecodeArmMOVTWInstruction(MCInst &Inst, unsigned Insn,
2118                                  uint64_t Address, const void *Decoder) {
2119   DecodeStatus S = MCDisassembler::Success;
2120 
2121   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2122   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2123   unsigned imm = 0;
2124 
2125   imm |= (fieldFromInstruction(Insn, 0, 12) << 0);
2126   imm |= (fieldFromInstruction(Insn, 16, 4) << 12);
2127 
2128   if (Inst.getOpcode() == ARM::MOVTi16)
2129     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2130       return MCDisassembler::Fail;
2131 
2132   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2133     return MCDisassembler::Fail;
2134 
2135   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
2136     Inst.addOperand(MCOperand::createImm(imm));
2137 
2138   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2139     return MCDisassembler::Fail;
2140 
2141   return S;
2142 }
2143 
2144 static DecodeStatus DecodeSMLAInstruction(MCInst &Inst, unsigned Insn,
2145                                  uint64_t Address, const void *Decoder) {
2146   DecodeStatus S = MCDisassembler::Success;
2147 
2148   unsigned Rd = fieldFromInstruction(Insn, 16, 4);
2149   unsigned Rn = fieldFromInstruction(Insn, 0, 4);
2150   unsigned Rm = fieldFromInstruction(Insn, 8, 4);
2151   unsigned Ra = fieldFromInstruction(Insn, 12, 4);
2152   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2153 
2154   if (pred == 0xF)
2155     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
2156 
2157   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2158     return MCDisassembler::Fail;
2159   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
2160     return MCDisassembler::Fail;
2161   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
2162     return MCDisassembler::Fail;
2163   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Ra, Address, Decoder)))
2164     return MCDisassembler::Fail;
2165 
2166   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2167     return MCDisassembler::Fail;
2168 
2169   return S;
2170 }
2171 
2172 static DecodeStatus DecodeTSTInstruction(MCInst &Inst, unsigned Insn,
2173                                   uint64_t Address, const void *Decoder) {
2174   DecodeStatus S = MCDisassembler::Success;
2175 
2176   unsigned Pred = fieldFromInstruction(Insn, 28, 4);
2177   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2178   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2179 
2180   if (Pred == 0xF)
2181     return DecodeSETPANInstruction(Inst, Insn, Address, Decoder);
2182 
2183   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2184     return MCDisassembler::Fail;
2185   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2186     return MCDisassembler::Fail;
2187   if (!Check(S, DecodePredicateOperand(Inst, Pred, Address, Decoder)))
2188     return MCDisassembler::Fail;
2189 
2190   return S;
2191 }
2192 
2193 static DecodeStatus DecodeSETPANInstruction(MCInst &Inst, unsigned Insn,
2194                                   uint64_t Address, const void *Decoder) {
2195   DecodeStatus S = MCDisassembler::Success;
2196 
2197   unsigned Imm = fieldFromInstruction(Insn, 9, 1);
2198 
2199   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
2200   const FeatureBitset &FeatureBits = Dis->getSubtargetInfo().getFeatureBits();
2201 
2202   if (!FeatureBits[ARM::HasV8_1aOps] ||
2203       !FeatureBits[ARM::HasV8Ops])
2204     return MCDisassembler::Fail;
2205 
2206   // Decoder can be called from DecodeTST, which does not check the full
2207   // encoding is valid.
2208   if (fieldFromInstruction(Insn, 20,12) != 0xf11 ||
2209       fieldFromInstruction(Insn, 4,4) != 0)
2210     return MCDisassembler::Fail;
2211   if (fieldFromInstruction(Insn, 10,10) != 0 ||
2212       fieldFromInstruction(Insn, 0,4) != 0)
2213     S = MCDisassembler::SoftFail;
2214 
2215   Inst.setOpcode(ARM::SETPAN);
2216   Inst.addOperand(MCOperand::createImm(Imm));
2217 
2218   return S;
2219 }
2220 
2221 static DecodeStatus DecodeAddrModeImm12Operand(MCInst &Inst, unsigned Val,
2222                            uint64_t Address, const void *Decoder) {
2223   DecodeStatus S = MCDisassembler::Success;
2224 
2225   unsigned add = fieldFromInstruction(Val, 12, 1);
2226   unsigned imm = fieldFromInstruction(Val, 0, 12);
2227   unsigned Rn = fieldFromInstruction(Val, 13, 4);
2228 
2229   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2230     return MCDisassembler::Fail;
2231 
2232   if (!add) imm *= -1;
2233   if (imm == 0 && !add) imm = INT32_MIN;
2234   Inst.addOperand(MCOperand::createImm(imm));
2235   if (Rn == 15)
2236     tryAddingPcLoadReferenceComment(Address, Address + imm + 8, Decoder);
2237 
2238   return S;
2239 }
2240 
2241 static DecodeStatus DecodeAddrMode5Operand(MCInst &Inst, unsigned Val,
2242                                    uint64_t Address, const void *Decoder) {
2243   DecodeStatus S = MCDisassembler::Success;
2244 
2245   unsigned Rn = fieldFromInstruction(Val, 9, 4);
2246   // U == 1 to add imm, 0 to subtract it.
2247   unsigned U = fieldFromInstruction(Val, 8, 1);
2248   unsigned imm = fieldFromInstruction(Val, 0, 8);
2249 
2250   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2251     return MCDisassembler::Fail;
2252 
2253   if (U)
2254     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5Opc(ARM_AM::add, imm)));
2255   else
2256     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5Opc(ARM_AM::sub, imm)));
2257 
2258   return S;
2259 }
2260 
2261 static DecodeStatus DecodeAddrMode5FP16Operand(MCInst &Inst, unsigned Val,
2262                                    uint64_t Address, const void *Decoder) {
2263   DecodeStatus S = MCDisassembler::Success;
2264 
2265   unsigned Rn = fieldFromInstruction(Val, 9, 4);
2266   // U == 1 to add imm, 0 to subtract it.
2267   unsigned U = fieldFromInstruction(Val, 8, 1);
2268   unsigned imm = fieldFromInstruction(Val, 0, 8);
2269 
2270   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2271     return MCDisassembler::Fail;
2272 
2273   if (U)
2274     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5FP16Opc(ARM_AM::add, imm)));
2275   else
2276     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5FP16Opc(ARM_AM::sub, imm)));
2277 
2278   return S;
2279 }
2280 
2281 static DecodeStatus DecodeAddrMode7Operand(MCInst &Inst, unsigned Val,
2282                                    uint64_t Address, const void *Decoder) {
2283   return DecodeGPRRegisterClass(Inst, Val, Address, Decoder);
2284 }
2285 
2286 static DecodeStatus
2287 DecodeT2BInstruction(MCInst &Inst, unsigned Insn,
2288                      uint64_t Address, const void *Decoder) {
2289   DecodeStatus Status = MCDisassembler::Success;
2290 
2291   // Note the J1 and J2 values are from the encoded instruction.  So here
2292   // change them to I1 and I2 values via as documented:
2293   // I1 = NOT(J1 EOR S);
2294   // I2 = NOT(J2 EOR S);
2295   // and build the imm32 with one trailing zero as documented:
2296   // imm32 = SignExtend(S:I1:I2:imm10:imm11:'0', 32);
2297   unsigned S = fieldFromInstruction(Insn, 26, 1);
2298   unsigned J1 = fieldFromInstruction(Insn, 13, 1);
2299   unsigned J2 = fieldFromInstruction(Insn, 11, 1);
2300   unsigned I1 = !(J1 ^ S);
2301   unsigned I2 = !(J2 ^ S);
2302   unsigned imm10 = fieldFromInstruction(Insn, 16, 10);
2303   unsigned imm11 = fieldFromInstruction(Insn, 0, 11);
2304   unsigned tmp = (S << 23) | (I1 << 22) | (I2 << 21) | (imm10 << 11) | imm11;
2305   int imm32 = SignExtend32<25>(tmp << 1);
2306   if (!tryAddingSymbolicOperand(Address, Address + imm32 + 4,
2307                                 true, 4, Inst, Decoder))
2308     Inst.addOperand(MCOperand::createImm(imm32));
2309 
2310   return Status;
2311 }
2312 
2313 static DecodeStatus
2314 DecodeBranchImmInstruction(MCInst &Inst, unsigned Insn,
2315                            uint64_t Address, const void *Decoder) {
2316   DecodeStatus S = MCDisassembler::Success;
2317 
2318   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2319   unsigned imm = fieldFromInstruction(Insn, 0, 24) << 2;
2320 
2321   if (pred == 0xF) {
2322     Inst.setOpcode(ARM::BLXi);
2323     imm |= fieldFromInstruction(Insn, 24, 1) << 1;
2324     if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<26>(imm) + 8,
2325                                   true, 4, Inst, Decoder))
2326     Inst.addOperand(MCOperand::createImm(SignExtend32<26>(imm)));
2327     return S;
2328   }
2329 
2330   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<26>(imm) + 8,
2331                                 true, 4, Inst, Decoder))
2332     Inst.addOperand(MCOperand::createImm(SignExtend32<26>(imm)));
2333   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2334     return MCDisassembler::Fail;
2335 
2336   return S;
2337 }
2338 
2339 static DecodeStatus DecodeAddrMode6Operand(MCInst &Inst, unsigned Val,
2340                                    uint64_t Address, const void *Decoder) {
2341   DecodeStatus S = MCDisassembler::Success;
2342 
2343   unsigned Rm = fieldFromInstruction(Val, 0, 4);
2344   unsigned align = fieldFromInstruction(Val, 4, 2);
2345 
2346   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2347     return MCDisassembler::Fail;
2348   if (!align)
2349     Inst.addOperand(MCOperand::createImm(0));
2350   else
2351     Inst.addOperand(MCOperand::createImm(4 << align));
2352 
2353   return S;
2354 }
2355 
2356 static DecodeStatus DecodeVLDInstruction(MCInst &Inst, unsigned Insn,
2357                                    uint64_t Address, const void *Decoder) {
2358   DecodeStatus S = MCDisassembler::Success;
2359 
2360   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2361   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
2362   unsigned wb = fieldFromInstruction(Insn, 16, 4);
2363   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2364   Rn |= fieldFromInstruction(Insn, 4, 2) << 4;
2365   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2366 
2367   // First output register
2368   switch (Inst.getOpcode()) {
2369   case ARM::VLD1q16: case ARM::VLD1q32: case ARM::VLD1q64: case ARM::VLD1q8:
2370   case ARM::VLD1q16wb_fixed: case ARM::VLD1q16wb_register:
2371   case ARM::VLD1q32wb_fixed: case ARM::VLD1q32wb_register:
2372   case ARM::VLD1q64wb_fixed: case ARM::VLD1q64wb_register:
2373   case ARM::VLD1q8wb_fixed: case ARM::VLD1q8wb_register:
2374   case ARM::VLD2d16: case ARM::VLD2d32: case ARM::VLD2d8:
2375   case ARM::VLD2d16wb_fixed: case ARM::VLD2d16wb_register:
2376   case ARM::VLD2d32wb_fixed: case ARM::VLD2d32wb_register:
2377   case ARM::VLD2d8wb_fixed: case ARM::VLD2d8wb_register:
2378     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
2379       return MCDisassembler::Fail;
2380     break;
2381   case ARM::VLD2b16:
2382   case ARM::VLD2b32:
2383   case ARM::VLD2b8:
2384   case ARM::VLD2b16wb_fixed:
2385   case ARM::VLD2b16wb_register:
2386   case ARM::VLD2b32wb_fixed:
2387   case ARM::VLD2b32wb_register:
2388   case ARM::VLD2b8wb_fixed:
2389   case ARM::VLD2b8wb_register:
2390     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
2391       return MCDisassembler::Fail;
2392     break;
2393   default:
2394     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2395       return MCDisassembler::Fail;
2396   }
2397 
2398   // Second output register
2399   switch (Inst.getOpcode()) {
2400     case ARM::VLD3d8:
2401     case ARM::VLD3d16:
2402     case ARM::VLD3d32:
2403     case ARM::VLD3d8_UPD:
2404     case ARM::VLD3d16_UPD:
2405     case ARM::VLD3d32_UPD:
2406     case ARM::VLD4d8:
2407     case ARM::VLD4d16:
2408     case ARM::VLD4d32:
2409     case ARM::VLD4d8_UPD:
2410     case ARM::VLD4d16_UPD:
2411     case ARM::VLD4d32_UPD:
2412       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
2413         return MCDisassembler::Fail;
2414       break;
2415     case ARM::VLD3q8:
2416     case ARM::VLD3q16:
2417     case ARM::VLD3q32:
2418     case ARM::VLD3q8_UPD:
2419     case ARM::VLD3q16_UPD:
2420     case ARM::VLD3q32_UPD:
2421     case ARM::VLD4q8:
2422     case ARM::VLD4q16:
2423     case ARM::VLD4q32:
2424     case ARM::VLD4q8_UPD:
2425     case ARM::VLD4q16_UPD:
2426     case ARM::VLD4q32_UPD:
2427       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2428         return MCDisassembler::Fail;
2429       break;
2430     default:
2431       break;
2432   }
2433 
2434   // Third output register
2435   switch(Inst.getOpcode()) {
2436     case ARM::VLD3d8:
2437     case ARM::VLD3d16:
2438     case ARM::VLD3d32:
2439     case ARM::VLD3d8_UPD:
2440     case ARM::VLD3d16_UPD:
2441     case ARM::VLD3d32_UPD:
2442     case ARM::VLD4d8:
2443     case ARM::VLD4d16:
2444     case ARM::VLD4d32:
2445     case ARM::VLD4d8_UPD:
2446     case ARM::VLD4d16_UPD:
2447     case ARM::VLD4d32_UPD:
2448       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2449         return MCDisassembler::Fail;
2450       break;
2451     case ARM::VLD3q8:
2452     case ARM::VLD3q16:
2453     case ARM::VLD3q32:
2454     case ARM::VLD3q8_UPD:
2455     case ARM::VLD3q16_UPD:
2456     case ARM::VLD3q32_UPD:
2457     case ARM::VLD4q8:
2458     case ARM::VLD4q16:
2459     case ARM::VLD4q32:
2460     case ARM::VLD4q8_UPD:
2461     case ARM::VLD4q16_UPD:
2462     case ARM::VLD4q32_UPD:
2463       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
2464         return MCDisassembler::Fail;
2465       break;
2466     default:
2467       break;
2468   }
2469 
2470   // Fourth output register
2471   switch (Inst.getOpcode()) {
2472     case ARM::VLD4d8:
2473     case ARM::VLD4d16:
2474     case ARM::VLD4d32:
2475     case ARM::VLD4d8_UPD:
2476     case ARM::VLD4d16_UPD:
2477     case ARM::VLD4d32_UPD:
2478       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
2479         return MCDisassembler::Fail;
2480       break;
2481     case ARM::VLD4q8:
2482     case ARM::VLD4q16:
2483     case ARM::VLD4q32:
2484     case ARM::VLD4q8_UPD:
2485     case ARM::VLD4q16_UPD:
2486     case ARM::VLD4q32_UPD:
2487       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
2488         return MCDisassembler::Fail;
2489       break;
2490     default:
2491       break;
2492   }
2493 
2494   // Writeback operand
2495   switch (Inst.getOpcode()) {
2496     case ARM::VLD1d8wb_fixed:
2497     case ARM::VLD1d16wb_fixed:
2498     case ARM::VLD1d32wb_fixed:
2499     case ARM::VLD1d64wb_fixed:
2500     case ARM::VLD1d8wb_register:
2501     case ARM::VLD1d16wb_register:
2502     case ARM::VLD1d32wb_register:
2503     case ARM::VLD1d64wb_register:
2504     case ARM::VLD1q8wb_fixed:
2505     case ARM::VLD1q16wb_fixed:
2506     case ARM::VLD1q32wb_fixed:
2507     case ARM::VLD1q64wb_fixed:
2508     case ARM::VLD1q8wb_register:
2509     case ARM::VLD1q16wb_register:
2510     case ARM::VLD1q32wb_register:
2511     case ARM::VLD1q64wb_register:
2512     case ARM::VLD1d8Twb_fixed:
2513     case ARM::VLD1d8Twb_register:
2514     case ARM::VLD1d16Twb_fixed:
2515     case ARM::VLD1d16Twb_register:
2516     case ARM::VLD1d32Twb_fixed:
2517     case ARM::VLD1d32Twb_register:
2518     case ARM::VLD1d64Twb_fixed:
2519     case ARM::VLD1d64Twb_register:
2520     case ARM::VLD1d8Qwb_fixed:
2521     case ARM::VLD1d8Qwb_register:
2522     case ARM::VLD1d16Qwb_fixed:
2523     case ARM::VLD1d16Qwb_register:
2524     case ARM::VLD1d32Qwb_fixed:
2525     case ARM::VLD1d32Qwb_register:
2526     case ARM::VLD1d64Qwb_fixed:
2527     case ARM::VLD1d64Qwb_register:
2528     case ARM::VLD2d8wb_fixed:
2529     case ARM::VLD2d16wb_fixed:
2530     case ARM::VLD2d32wb_fixed:
2531     case ARM::VLD2q8wb_fixed:
2532     case ARM::VLD2q16wb_fixed:
2533     case ARM::VLD2q32wb_fixed:
2534     case ARM::VLD2d8wb_register:
2535     case ARM::VLD2d16wb_register:
2536     case ARM::VLD2d32wb_register:
2537     case ARM::VLD2q8wb_register:
2538     case ARM::VLD2q16wb_register:
2539     case ARM::VLD2q32wb_register:
2540     case ARM::VLD2b8wb_fixed:
2541     case ARM::VLD2b16wb_fixed:
2542     case ARM::VLD2b32wb_fixed:
2543     case ARM::VLD2b8wb_register:
2544     case ARM::VLD2b16wb_register:
2545     case ARM::VLD2b32wb_register:
2546       Inst.addOperand(MCOperand::createImm(0));
2547       break;
2548     case ARM::VLD3d8_UPD:
2549     case ARM::VLD3d16_UPD:
2550     case ARM::VLD3d32_UPD:
2551     case ARM::VLD3q8_UPD:
2552     case ARM::VLD3q16_UPD:
2553     case ARM::VLD3q32_UPD:
2554     case ARM::VLD4d8_UPD:
2555     case ARM::VLD4d16_UPD:
2556     case ARM::VLD4d32_UPD:
2557     case ARM::VLD4q8_UPD:
2558     case ARM::VLD4q16_UPD:
2559     case ARM::VLD4q32_UPD:
2560       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
2561         return MCDisassembler::Fail;
2562       break;
2563     default:
2564       break;
2565   }
2566 
2567   // AddrMode6 Base (register+alignment)
2568   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
2569     return MCDisassembler::Fail;
2570 
2571   // AddrMode6 Offset (register)
2572   switch (Inst.getOpcode()) {
2573   default:
2574     // The below have been updated to have explicit am6offset split
2575     // between fixed and register offset. For those instructions not
2576     // yet updated, we need to add an additional reg0 operand for the
2577     // fixed variant.
2578     //
2579     // The fixed offset encodes as Rm == 0xd, so we check for that.
2580     if (Rm == 0xd) {
2581       Inst.addOperand(MCOperand::createReg(0));
2582       break;
2583     }
2584     // Fall through to handle the register offset variant.
2585     LLVM_FALLTHROUGH;
2586   case ARM::VLD1d8wb_fixed:
2587   case ARM::VLD1d16wb_fixed:
2588   case ARM::VLD1d32wb_fixed:
2589   case ARM::VLD1d64wb_fixed:
2590   case ARM::VLD1d8Twb_fixed:
2591   case ARM::VLD1d16Twb_fixed:
2592   case ARM::VLD1d32Twb_fixed:
2593   case ARM::VLD1d64Twb_fixed:
2594   case ARM::VLD1d8Qwb_fixed:
2595   case ARM::VLD1d16Qwb_fixed:
2596   case ARM::VLD1d32Qwb_fixed:
2597   case ARM::VLD1d64Qwb_fixed:
2598   case ARM::VLD1d8wb_register:
2599   case ARM::VLD1d16wb_register:
2600   case ARM::VLD1d32wb_register:
2601   case ARM::VLD1d64wb_register:
2602   case ARM::VLD1q8wb_fixed:
2603   case ARM::VLD1q16wb_fixed:
2604   case ARM::VLD1q32wb_fixed:
2605   case ARM::VLD1q64wb_fixed:
2606   case ARM::VLD1q8wb_register:
2607   case ARM::VLD1q16wb_register:
2608   case ARM::VLD1q32wb_register:
2609   case ARM::VLD1q64wb_register:
2610     // The fixed offset post-increment encodes Rm == 0xd. The no-writeback
2611     // variant encodes Rm == 0xf. Anything else is a register offset post-
2612     // increment and we need to add the register operand to the instruction.
2613     if (Rm != 0xD && Rm != 0xF &&
2614         !Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2615       return MCDisassembler::Fail;
2616     break;
2617   case ARM::VLD2d8wb_fixed:
2618   case ARM::VLD2d16wb_fixed:
2619   case ARM::VLD2d32wb_fixed:
2620   case ARM::VLD2b8wb_fixed:
2621   case ARM::VLD2b16wb_fixed:
2622   case ARM::VLD2b32wb_fixed:
2623   case ARM::VLD2q8wb_fixed:
2624   case ARM::VLD2q16wb_fixed:
2625   case ARM::VLD2q32wb_fixed:
2626     break;
2627   }
2628 
2629   return S;
2630 }
2631 
2632 static DecodeStatus DecodeVLDST1Instruction(MCInst &Inst, unsigned Insn,
2633                                    uint64_t Address, const void *Decoder) {
2634   unsigned type = fieldFromInstruction(Insn, 8, 4);
2635   unsigned align = fieldFromInstruction(Insn, 4, 2);
2636   if (type == 6 && (align & 2)) return MCDisassembler::Fail;
2637   if (type == 7 && (align & 2)) return MCDisassembler::Fail;
2638   if (type == 10 && align == 3) return MCDisassembler::Fail;
2639 
2640   unsigned load = fieldFromInstruction(Insn, 21, 1);
2641   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2642               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2643 }
2644 
2645 static DecodeStatus DecodeVLDST2Instruction(MCInst &Inst, unsigned Insn,
2646                                    uint64_t Address, const void *Decoder) {
2647   unsigned size = fieldFromInstruction(Insn, 6, 2);
2648   if (size == 3) return MCDisassembler::Fail;
2649 
2650   unsigned type = fieldFromInstruction(Insn, 8, 4);
2651   unsigned align = fieldFromInstruction(Insn, 4, 2);
2652   if (type == 8 && align == 3) return MCDisassembler::Fail;
2653   if (type == 9 && align == 3) return MCDisassembler::Fail;
2654 
2655   unsigned load = fieldFromInstruction(Insn, 21, 1);
2656   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2657               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2658 }
2659 
2660 static DecodeStatus DecodeVLDST3Instruction(MCInst &Inst, unsigned Insn,
2661                                    uint64_t Address, const void *Decoder) {
2662   unsigned size = fieldFromInstruction(Insn, 6, 2);
2663   if (size == 3) return MCDisassembler::Fail;
2664 
2665   unsigned align = fieldFromInstruction(Insn, 4, 2);
2666   if (align & 2) return MCDisassembler::Fail;
2667 
2668   unsigned load = fieldFromInstruction(Insn, 21, 1);
2669   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2670               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2671 }
2672 
2673 static DecodeStatus DecodeVLDST4Instruction(MCInst &Inst, unsigned Insn,
2674                                    uint64_t Address, const void *Decoder) {
2675   unsigned size = fieldFromInstruction(Insn, 6, 2);
2676   if (size == 3) return MCDisassembler::Fail;
2677 
2678   unsigned load = fieldFromInstruction(Insn, 21, 1);
2679   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2680               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2681 }
2682 
2683 static DecodeStatus DecodeVSTInstruction(MCInst &Inst, unsigned Insn,
2684                                  uint64_t Address, const void *Decoder) {
2685   DecodeStatus S = MCDisassembler::Success;
2686 
2687   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2688   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
2689   unsigned wb = fieldFromInstruction(Insn, 16, 4);
2690   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2691   Rn |= fieldFromInstruction(Insn, 4, 2) << 4;
2692   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2693 
2694   // Writeback Operand
2695   switch (Inst.getOpcode()) {
2696     case ARM::VST1d8wb_fixed:
2697     case ARM::VST1d16wb_fixed:
2698     case ARM::VST1d32wb_fixed:
2699     case ARM::VST1d64wb_fixed:
2700     case ARM::VST1d8wb_register:
2701     case ARM::VST1d16wb_register:
2702     case ARM::VST1d32wb_register:
2703     case ARM::VST1d64wb_register:
2704     case ARM::VST1q8wb_fixed:
2705     case ARM::VST1q16wb_fixed:
2706     case ARM::VST1q32wb_fixed:
2707     case ARM::VST1q64wb_fixed:
2708     case ARM::VST1q8wb_register:
2709     case ARM::VST1q16wb_register:
2710     case ARM::VST1q32wb_register:
2711     case ARM::VST1q64wb_register:
2712     case ARM::VST1d8Twb_fixed:
2713     case ARM::VST1d16Twb_fixed:
2714     case ARM::VST1d32Twb_fixed:
2715     case ARM::VST1d64Twb_fixed:
2716     case ARM::VST1d8Twb_register:
2717     case ARM::VST1d16Twb_register:
2718     case ARM::VST1d32Twb_register:
2719     case ARM::VST1d64Twb_register:
2720     case ARM::VST1d8Qwb_fixed:
2721     case ARM::VST1d16Qwb_fixed:
2722     case ARM::VST1d32Qwb_fixed:
2723     case ARM::VST1d64Qwb_fixed:
2724     case ARM::VST1d8Qwb_register:
2725     case ARM::VST1d16Qwb_register:
2726     case ARM::VST1d32Qwb_register:
2727     case ARM::VST1d64Qwb_register:
2728     case ARM::VST2d8wb_fixed:
2729     case ARM::VST2d16wb_fixed:
2730     case ARM::VST2d32wb_fixed:
2731     case ARM::VST2d8wb_register:
2732     case ARM::VST2d16wb_register:
2733     case ARM::VST2d32wb_register:
2734     case ARM::VST2q8wb_fixed:
2735     case ARM::VST2q16wb_fixed:
2736     case ARM::VST2q32wb_fixed:
2737     case ARM::VST2q8wb_register:
2738     case ARM::VST2q16wb_register:
2739     case ARM::VST2q32wb_register:
2740     case ARM::VST2b8wb_fixed:
2741     case ARM::VST2b16wb_fixed:
2742     case ARM::VST2b32wb_fixed:
2743     case ARM::VST2b8wb_register:
2744     case ARM::VST2b16wb_register:
2745     case ARM::VST2b32wb_register:
2746       if (Rm == 0xF)
2747         return MCDisassembler::Fail;
2748       Inst.addOperand(MCOperand::createImm(0));
2749       break;
2750     case ARM::VST3d8_UPD:
2751     case ARM::VST3d16_UPD:
2752     case ARM::VST3d32_UPD:
2753     case ARM::VST3q8_UPD:
2754     case ARM::VST3q16_UPD:
2755     case ARM::VST3q32_UPD:
2756     case ARM::VST4d8_UPD:
2757     case ARM::VST4d16_UPD:
2758     case ARM::VST4d32_UPD:
2759     case ARM::VST4q8_UPD:
2760     case ARM::VST4q16_UPD:
2761     case ARM::VST4q32_UPD:
2762       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
2763         return MCDisassembler::Fail;
2764       break;
2765     default:
2766       break;
2767   }
2768 
2769   // AddrMode6 Base (register+alignment)
2770   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
2771     return MCDisassembler::Fail;
2772 
2773   // AddrMode6 Offset (register)
2774   switch (Inst.getOpcode()) {
2775     default:
2776       if (Rm == 0xD)
2777         Inst.addOperand(MCOperand::createReg(0));
2778       else if (Rm != 0xF) {
2779         if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2780           return MCDisassembler::Fail;
2781       }
2782       break;
2783     case ARM::VST1d8wb_fixed:
2784     case ARM::VST1d16wb_fixed:
2785     case ARM::VST1d32wb_fixed:
2786     case ARM::VST1d64wb_fixed:
2787     case ARM::VST1q8wb_fixed:
2788     case ARM::VST1q16wb_fixed:
2789     case ARM::VST1q32wb_fixed:
2790     case ARM::VST1q64wb_fixed:
2791     case ARM::VST1d8Twb_fixed:
2792     case ARM::VST1d16Twb_fixed:
2793     case ARM::VST1d32Twb_fixed:
2794     case ARM::VST1d64Twb_fixed:
2795     case ARM::VST1d8Qwb_fixed:
2796     case ARM::VST1d16Qwb_fixed:
2797     case ARM::VST1d32Qwb_fixed:
2798     case ARM::VST1d64Qwb_fixed:
2799     case ARM::VST2d8wb_fixed:
2800     case ARM::VST2d16wb_fixed:
2801     case ARM::VST2d32wb_fixed:
2802     case ARM::VST2q8wb_fixed:
2803     case ARM::VST2q16wb_fixed:
2804     case ARM::VST2q32wb_fixed:
2805     case ARM::VST2b8wb_fixed:
2806     case ARM::VST2b16wb_fixed:
2807     case ARM::VST2b32wb_fixed:
2808       break;
2809   }
2810 
2811   // First input register
2812   switch (Inst.getOpcode()) {
2813   case ARM::VST1q16:
2814   case ARM::VST1q32:
2815   case ARM::VST1q64:
2816   case ARM::VST1q8:
2817   case ARM::VST1q16wb_fixed:
2818   case ARM::VST1q16wb_register:
2819   case ARM::VST1q32wb_fixed:
2820   case ARM::VST1q32wb_register:
2821   case ARM::VST1q64wb_fixed:
2822   case ARM::VST1q64wb_register:
2823   case ARM::VST1q8wb_fixed:
2824   case ARM::VST1q8wb_register:
2825   case ARM::VST2d16:
2826   case ARM::VST2d32:
2827   case ARM::VST2d8:
2828   case ARM::VST2d16wb_fixed:
2829   case ARM::VST2d16wb_register:
2830   case ARM::VST2d32wb_fixed:
2831   case ARM::VST2d32wb_register:
2832   case ARM::VST2d8wb_fixed:
2833   case ARM::VST2d8wb_register:
2834     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
2835       return MCDisassembler::Fail;
2836     break;
2837   case ARM::VST2b16:
2838   case ARM::VST2b32:
2839   case ARM::VST2b8:
2840   case ARM::VST2b16wb_fixed:
2841   case ARM::VST2b16wb_register:
2842   case ARM::VST2b32wb_fixed:
2843   case ARM::VST2b32wb_register:
2844   case ARM::VST2b8wb_fixed:
2845   case ARM::VST2b8wb_register:
2846     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
2847       return MCDisassembler::Fail;
2848     break;
2849   default:
2850     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2851       return MCDisassembler::Fail;
2852   }
2853 
2854   // Second input register
2855   switch (Inst.getOpcode()) {
2856     case ARM::VST3d8:
2857     case ARM::VST3d16:
2858     case ARM::VST3d32:
2859     case ARM::VST3d8_UPD:
2860     case ARM::VST3d16_UPD:
2861     case ARM::VST3d32_UPD:
2862     case ARM::VST4d8:
2863     case ARM::VST4d16:
2864     case ARM::VST4d32:
2865     case ARM::VST4d8_UPD:
2866     case ARM::VST4d16_UPD:
2867     case ARM::VST4d32_UPD:
2868       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
2869         return MCDisassembler::Fail;
2870       break;
2871     case ARM::VST3q8:
2872     case ARM::VST3q16:
2873     case ARM::VST3q32:
2874     case ARM::VST3q8_UPD:
2875     case ARM::VST3q16_UPD:
2876     case ARM::VST3q32_UPD:
2877     case ARM::VST4q8:
2878     case ARM::VST4q16:
2879     case ARM::VST4q32:
2880     case ARM::VST4q8_UPD:
2881     case ARM::VST4q16_UPD:
2882     case ARM::VST4q32_UPD:
2883       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2884         return MCDisassembler::Fail;
2885       break;
2886     default:
2887       break;
2888   }
2889 
2890   // Third input register
2891   switch (Inst.getOpcode()) {
2892     case ARM::VST3d8:
2893     case ARM::VST3d16:
2894     case ARM::VST3d32:
2895     case ARM::VST3d8_UPD:
2896     case ARM::VST3d16_UPD:
2897     case ARM::VST3d32_UPD:
2898     case ARM::VST4d8:
2899     case ARM::VST4d16:
2900     case ARM::VST4d32:
2901     case ARM::VST4d8_UPD:
2902     case ARM::VST4d16_UPD:
2903     case ARM::VST4d32_UPD:
2904       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2905         return MCDisassembler::Fail;
2906       break;
2907     case ARM::VST3q8:
2908     case ARM::VST3q16:
2909     case ARM::VST3q32:
2910     case ARM::VST3q8_UPD:
2911     case ARM::VST3q16_UPD:
2912     case ARM::VST3q32_UPD:
2913     case ARM::VST4q8:
2914     case ARM::VST4q16:
2915     case ARM::VST4q32:
2916     case ARM::VST4q8_UPD:
2917     case ARM::VST4q16_UPD:
2918     case ARM::VST4q32_UPD:
2919       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
2920         return MCDisassembler::Fail;
2921       break;
2922     default:
2923       break;
2924   }
2925 
2926   // Fourth input register
2927   switch (Inst.getOpcode()) {
2928     case ARM::VST4d8:
2929     case ARM::VST4d16:
2930     case ARM::VST4d32:
2931     case ARM::VST4d8_UPD:
2932     case ARM::VST4d16_UPD:
2933     case ARM::VST4d32_UPD:
2934       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
2935         return MCDisassembler::Fail;
2936       break;
2937     case ARM::VST4q8:
2938     case ARM::VST4q16:
2939     case ARM::VST4q32:
2940     case ARM::VST4q8_UPD:
2941     case ARM::VST4q16_UPD:
2942     case ARM::VST4q32_UPD:
2943       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
2944         return MCDisassembler::Fail;
2945       break;
2946     default:
2947       break;
2948   }
2949 
2950   return S;
2951 }
2952 
2953 static DecodeStatus DecodeVLD1DupInstruction(MCInst &Inst, unsigned Insn,
2954                                     uint64_t Address, const void *Decoder) {
2955   DecodeStatus S = MCDisassembler::Success;
2956 
2957   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2958   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
2959   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2960   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2961   unsigned align = fieldFromInstruction(Insn, 4, 1);
2962   unsigned size = fieldFromInstruction(Insn, 6, 2);
2963 
2964   if (size == 0 && align == 1)
2965     return MCDisassembler::Fail;
2966   align *= (1 << size);
2967 
2968   switch (Inst.getOpcode()) {
2969   case ARM::VLD1DUPq16: case ARM::VLD1DUPq32: case ARM::VLD1DUPq8:
2970   case ARM::VLD1DUPq16wb_fixed: case ARM::VLD1DUPq16wb_register:
2971   case ARM::VLD1DUPq32wb_fixed: case ARM::VLD1DUPq32wb_register:
2972   case ARM::VLD1DUPq8wb_fixed: case ARM::VLD1DUPq8wb_register:
2973     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
2974       return MCDisassembler::Fail;
2975     break;
2976   default:
2977     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2978       return MCDisassembler::Fail;
2979     break;
2980   }
2981   if (Rm != 0xF) {
2982     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2983       return MCDisassembler::Fail;
2984   }
2985 
2986   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2987     return MCDisassembler::Fail;
2988   Inst.addOperand(MCOperand::createImm(align));
2989 
2990   // The fixed offset post-increment encodes Rm == 0xd. The no-writeback
2991   // variant encodes Rm == 0xf. Anything else is a register offset post-
2992   // increment and we need to add the register operand to the instruction.
2993   if (Rm != 0xD && Rm != 0xF &&
2994       !Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2995     return MCDisassembler::Fail;
2996 
2997   return S;
2998 }
2999 
3000 static DecodeStatus DecodeVLD2DupInstruction(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 align = fieldFromInstruction(Insn, 4, 1);
3009   unsigned size = 1 << fieldFromInstruction(Insn, 6, 2);
3010   align *= 2*size;
3011 
3012   switch (Inst.getOpcode()) {
3013   case ARM::VLD2DUPd16: case ARM::VLD2DUPd32: case ARM::VLD2DUPd8:
3014   case ARM::VLD2DUPd16wb_fixed: case ARM::VLD2DUPd16wb_register:
3015   case ARM::VLD2DUPd32wb_fixed: case ARM::VLD2DUPd32wb_register:
3016   case ARM::VLD2DUPd8wb_fixed: case ARM::VLD2DUPd8wb_register:
3017     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3018       return MCDisassembler::Fail;
3019     break;
3020   case ARM::VLD2DUPd16x2: case ARM::VLD2DUPd32x2: case ARM::VLD2DUPd8x2:
3021   case ARM::VLD2DUPd16x2wb_fixed: case ARM::VLD2DUPd16x2wb_register:
3022   case ARM::VLD2DUPd32x2wb_fixed: case ARM::VLD2DUPd32x2wb_register:
3023   case ARM::VLD2DUPd8x2wb_fixed: case ARM::VLD2DUPd8x2wb_register:
3024     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
3025       return MCDisassembler::Fail;
3026     break;
3027   default:
3028     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3029       return MCDisassembler::Fail;
3030     break;
3031   }
3032 
3033   if (Rm != 0xF)
3034     Inst.addOperand(MCOperand::createImm(0));
3035 
3036   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3037     return MCDisassembler::Fail;
3038   Inst.addOperand(MCOperand::createImm(align));
3039 
3040   if (Rm != 0xD && Rm != 0xF) {
3041     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3042       return MCDisassembler::Fail;
3043   }
3044 
3045   return S;
3046 }
3047 
3048 static DecodeStatus DecodeVLD3DupInstruction(MCInst &Inst, unsigned Insn,
3049                                     uint64_t Address, const void *Decoder) {
3050   DecodeStatus S = MCDisassembler::Success;
3051 
3052   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3053   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3054   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3055   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3056   unsigned inc = fieldFromInstruction(Insn, 5, 1) + 1;
3057 
3058   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3059     return MCDisassembler::Fail;
3060   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
3061     return MCDisassembler::Fail;
3062   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
3063     return MCDisassembler::Fail;
3064   if (Rm != 0xF) {
3065     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3066       return MCDisassembler::Fail;
3067   }
3068 
3069   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3070     return MCDisassembler::Fail;
3071   Inst.addOperand(MCOperand::createImm(0));
3072 
3073   if (Rm == 0xD)
3074     Inst.addOperand(MCOperand::createReg(0));
3075   else if (Rm != 0xF) {
3076     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3077       return MCDisassembler::Fail;
3078   }
3079 
3080   return S;
3081 }
3082 
3083 static DecodeStatus DecodeVLD4DupInstruction(MCInst &Inst, unsigned Insn,
3084                                     uint64_t Address, const void *Decoder) {
3085   DecodeStatus S = MCDisassembler::Success;
3086 
3087   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3088   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3089   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3090   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3091   unsigned size = fieldFromInstruction(Insn, 6, 2);
3092   unsigned inc = fieldFromInstruction(Insn, 5, 1) + 1;
3093   unsigned align = fieldFromInstruction(Insn, 4, 1);
3094 
3095   if (size == 0x3) {
3096     if (align == 0)
3097       return MCDisassembler::Fail;
3098     align = 16;
3099   } else {
3100     if (size == 2) {
3101       align *= 8;
3102     } else {
3103       size = 1 << size;
3104       align *= 4*size;
3105     }
3106   }
3107 
3108   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3109     return MCDisassembler::Fail;
3110   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
3111     return MCDisassembler::Fail;
3112   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
3113     return MCDisassembler::Fail;
3114   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3*inc)%32, Address, Decoder)))
3115     return MCDisassembler::Fail;
3116   if (Rm != 0xF) {
3117     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3118       return MCDisassembler::Fail;
3119   }
3120 
3121   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3122     return MCDisassembler::Fail;
3123   Inst.addOperand(MCOperand::createImm(align));
3124 
3125   if (Rm == 0xD)
3126     Inst.addOperand(MCOperand::createReg(0));
3127   else if (Rm != 0xF) {
3128     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3129       return MCDisassembler::Fail;
3130   }
3131 
3132   return S;
3133 }
3134 
3135 static DecodeStatus
3136 DecodeNEONModImmInstruction(MCInst &Inst, unsigned Insn,
3137                             uint64_t Address, const void *Decoder) {
3138   DecodeStatus S = MCDisassembler::Success;
3139 
3140   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3141   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3142   unsigned imm = fieldFromInstruction(Insn, 0, 4);
3143   imm |= fieldFromInstruction(Insn, 16, 3) << 4;
3144   imm |= fieldFromInstruction(Insn, 24, 1) << 7;
3145   imm |= fieldFromInstruction(Insn, 8, 4) << 8;
3146   imm |= fieldFromInstruction(Insn, 5, 1) << 12;
3147   unsigned Q = fieldFromInstruction(Insn, 6, 1);
3148 
3149   if (Q) {
3150     if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3151     return MCDisassembler::Fail;
3152   } else {
3153     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3154     return MCDisassembler::Fail;
3155   }
3156 
3157   Inst.addOperand(MCOperand::createImm(imm));
3158 
3159   switch (Inst.getOpcode()) {
3160     case ARM::VORRiv4i16:
3161     case ARM::VORRiv2i32:
3162     case ARM::VBICiv4i16:
3163     case ARM::VBICiv2i32:
3164       if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3165         return MCDisassembler::Fail;
3166       break;
3167     case ARM::VORRiv8i16:
3168     case ARM::VORRiv4i32:
3169     case ARM::VBICiv8i16:
3170     case ARM::VBICiv4i32:
3171       if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3172         return MCDisassembler::Fail;
3173       break;
3174     default:
3175       break;
3176   }
3177 
3178   return S;
3179 }
3180 
3181 static DecodeStatus DecodeVSHLMaxInstruction(MCInst &Inst, unsigned Insn,
3182                                         uint64_t Address, const void *Decoder) {
3183   DecodeStatus S = MCDisassembler::Success;
3184 
3185   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3186   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3187   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3188   Rm |= fieldFromInstruction(Insn, 5, 1) << 4;
3189   unsigned size = fieldFromInstruction(Insn, 18, 2);
3190 
3191   if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3192     return MCDisassembler::Fail;
3193   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
3194     return MCDisassembler::Fail;
3195   Inst.addOperand(MCOperand::createImm(8 << size));
3196 
3197   return S;
3198 }
3199 
3200 static DecodeStatus DecodeShiftRight8Imm(MCInst &Inst, unsigned Val,
3201                                uint64_t Address, const void *Decoder) {
3202   Inst.addOperand(MCOperand::createImm(8 - Val));
3203   return MCDisassembler::Success;
3204 }
3205 
3206 static DecodeStatus DecodeShiftRight16Imm(MCInst &Inst, unsigned Val,
3207                                uint64_t Address, const void *Decoder) {
3208   Inst.addOperand(MCOperand::createImm(16 - Val));
3209   return MCDisassembler::Success;
3210 }
3211 
3212 static DecodeStatus DecodeShiftRight32Imm(MCInst &Inst, unsigned Val,
3213                                uint64_t Address, const void *Decoder) {
3214   Inst.addOperand(MCOperand::createImm(32 - Val));
3215   return MCDisassembler::Success;
3216 }
3217 
3218 static DecodeStatus DecodeShiftRight64Imm(MCInst &Inst, unsigned Val,
3219                                uint64_t Address, const void *Decoder) {
3220   Inst.addOperand(MCOperand::createImm(64 - Val));
3221   return MCDisassembler::Success;
3222 }
3223 
3224 static DecodeStatus DecodeTBLInstruction(MCInst &Inst, unsigned Insn,
3225                                uint64_t Address, const void *Decoder) {
3226   DecodeStatus S = MCDisassembler::Success;
3227 
3228   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3229   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3230   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3231   Rn |= fieldFromInstruction(Insn, 7, 1) << 4;
3232   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3233   Rm |= fieldFromInstruction(Insn, 5, 1) << 4;
3234   unsigned op = fieldFromInstruction(Insn, 6, 1);
3235 
3236   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3237     return MCDisassembler::Fail;
3238   if (op) {
3239     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3240     return MCDisassembler::Fail; // Writeback
3241   }
3242 
3243   switch (Inst.getOpcode()) {
3244   case ARM::VTBL2:
3245   case ARM::VTBX2:
3246     if (!Check(S, DecodeDPairRegisterClass(Inst, Rn, Address, Decoder)))
3247       return MCDisassembler::Fail;
3248     break;
3249   default:
3250     if (!Check(S, DecodeDPRRegisterClass(Inst, Rn, Address, Decoder)))
3251       return MCDisassembler::Fail;
3252   }
3253 
3254   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
3255     return MCDisassembler::Fail;
3256 
3257   return S;
3258 }
3259 
3260 static DecodeStatus DecodeThumbAddSpecialReg(MCInst &Inst, uint16_t Insn,
3261                                      uint64_t Address, const void *Decoder) {
3262   DecodeStatus S = MCDisassembler::Success;
3263 
3264   unsigned dst = fieldFromInstruction(Insn, 8, 3);
3265   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3266 
3267   if (!Check(S, DecodetGPRRegisterClass(Inst, dst, Address, Decoder)))
3268     return MCDisassembler::Fail;
3269 
3270   switch(Inst.getOpcode()) {
3271     default:
3272       return MCDisassembler::Fail;
3273     case ARM::tADR:
3274       break; // tADR does not explicitly represent the PC as an operand.
3275     case ARM::tADDrSPi:
3276       Inst.addOperand(MCOperand::createReg(ARM::SP));
3277       break;
3278   }
3279 
3280   Inst.addOperand(MCOperand::createImm(imm));
3281   return S;
3282 }
3283 
3284 static DecodeStatus DecodeThumbBROperand(MCInst &Inst, unsigned Val,
3285                                  uint64_t Address, const void *Decoder) {
3286   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<12>(Val<<1) + 4,
3287                                 true, 2, Inst, Decoder))
3288     Inst.addOperand(MCOperand::createImm(SignExtend32<12>(Val << 1)));
3289   return MCDisassembler::Success;
3290 }
3291 
3292 static DecodeStatus DecodeT2BROperand(MCInst &Inst, unsigned Val,
3293                                  uint64_t Address, const void *Decoder) {
3294   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<21>(Val) + 4,
3295                                 true, 4, Inst, Decoder))
3296     Inst.addOperand(MCOperand::createImm(SignExtend32<21>(Val)));
3297   return MCDisassembler::Success;
3298 }
3299 
3300 static DecodeStatus DecodeThumbCmpBROperand(MCInst &Inst, unsigned Val,
3301                                  uint64_t Address, const void *Decoder) {
3302   if (!tryAddingSymbolicOperand(Address, Address + (Val<<1) + 4,
3303                                 true, 2, Inst, Decoder))
3304     Inst.addOperand(MCOperand::createImm(Val << 1));
3305   return MCDisassembler::Success;
3306 }
3307 
3308 static DecodeStatus DecodeThumbAddrModeRR(MCInst &Inst, unsigned Val,
3309                                  uint64_t Address, const void *Decoder) {
3310   DecodeStatus S = MCDisassembler::Success;
3311 
3312   unsigned Rn = fieldFromInstruction(Val, 0, 3);
3313   unsigned Rm = fieldFromInstruction(Val, 3, 3);
3314 
3315   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
3316     return MCDisassembler::Fail;
3317   if (!Check(S, DecodetGPRRegisterClass(Inst, Rm, Address, Decoder)))
3318     return MCDisassembler::Fail;
3319 
3320   return S;
3321 }
3322 
3323 static DecodeStatus DecodeThumbAddrModeIS(MCInst &Inst, unsigned Val,
3324                                   uint64_t Address, const void *Decoder) {
3325   DecodeStatus S = MCDisassembler::Success;
3326 
3327   unsigned Rn = fieldFromInstruction(Val, 0, 3);
3328   unsigned imm = fieldFromInstruction(Val, 3, 5);
3329 
3330   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
3331     return MCDisassembler::Fail;
3332   Inst.addOperand(MCOperand::createImm(imm));
3333 
3334   return S;
3335 }
3336 
3337 static DecodeStatus DecodeThumbAddrModePC(MCInst &Inst, unsigned Val,
3338                                   uint64_t Address, const void *Decoder) {
3339   unsigned imm = Val << 2;
3340 
3341   Inst.addOperand(MCOperand::createImm(imm));
3342   tryAddingPcLoadReferenceComment(Address, (Address & ~2u) + imm + 4, Decoder);
3343 
3344   return MCDisassembler::Success;
3345 }
3346 
3347 static DecodeStatus DecodeThumbAddrModeSP(MCInst &Inst, unsigned Val,
3348                                   uint64_t Address, const void *Decoder) {
3349   Inst.addOperand(MCOperand::createReg(ARM::SP));
3350   Inst.addOperand(MCOperand::createImm(Val));
3351 
3352   return MCDisassembler::Success;
3353 }
3354 
3355 static DecodeStatus DecodeT2AddrModeSOReg(MCInst &Inst, unsigned Val,
3356                                   uint64_t Address, const void *Decoder) {
3357   DecodeStatus S = MCDisassembler::Success;
3358 
3359   unsigned Rn = fieldFromInstruction(Val, 6, 4);
3360   unsigned Rm = fieldFromInstruction(Val, 2, 4);
3361   unsigned imm = fieldFromInstruction(Val, 0, 2);
3362 
3363   // Thumb stores cannot use PC as dest register.
3364   switch (Inst.getOpcode()) {
3365   case ARM::t2STRHs:
3366   case ARM::t2STRBs:
3367   case ARM::t2STRs:
3368     if (Rn == 15)
3369       return MCDisassembler::Fail;
3370     break;
3371   default:
3372     break;
3373   }
3374 
3375   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3376     return MCDisassembler::Fail;
3377   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
3378     return MCDisassembler::Fail;
3379   Inst.addOperand(MCOperand::createImm(imm));
3380 
3381   return S;
3382 }
3383 
3384 static DecodeStatus DecodeT2LoadShift(MCInst &Inst, unsigned Insn,
3385                               uint64_t Address, const void *Decoder) {
3386   DecodeStatus S = MCDisassembler::Success;
3387 
3388   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3389   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3390 
3391   const FeatureBitset &featureBits =
3392     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3393 
3394   bool hasMP = featureBits[ARM::FeatureMP];
3395   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3396 
3397   if (Rn == 15) {
3398     switch (Inst.getOpcode()) {
3399     case ARM::t2LDRBs:
3400       Inst.setOpcode(ARM::t2LDRBpci);
3401       break;
3402     case ARM::t2LDRHs:
3403       Inst.setOpcode(ARM::t2LDRHpci);
3404       break;
3405     case ARM::t2LDRSHs:
3406       Inst.setOpcode(ARM::t2LDRSHpci);
3407       break;
3408     case ARM::t2LDRSBs:
3409       Inst.setOpcode(ARM::t2LDRSBpci);
3410       break;
3411     case ARM::t2LDRs:
3412       Inst.setOpcode(ARM::t2LDRpci);
3413       break;
3414     case ARM::t2PLDs:
3415       Inst.setOpcode(ARM::t2PLDpci);
3416       break;
3417     case ARM::t2PLIs:
3418       Inst.setOpcode(ARM::t2PLIpci);
3419       break;
3420     default:
3421       return MCDisassembler::Fail;
3422     }
3423 
3424     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3425   }
3426 
3427   if (Rt == 15) {
3428     switch (Inst.getOpcode()) {
3429     case ARM::t2LDRSHs:
3430       return MCDisassembler::Fail;
3431     case ARM::t2LDRHs:
3432       Inst.setOpcode(ARM::t2PLDWs);
3433       break;
3434     case ARM::t2LDRSBs:
3435       Inst.setOpcode(ARM::t2PLIs);
3436       break;
3437     default:
3438       break;
3439     }
3440   }
3441 
3442   switch (Inst.getOpcode()) {
3443     case ARM::t2PLDs:
3444       break;
3445     case ARM::t2PLIs:
3446       if (!hasV7Ops)
3447         return MCDisassembler::Fail;
3448       break;
3449     case ARM::t2PLDWs:
3450       if (!hasV7Ops || !hasMP)
3451         return MCDisassembler::Fail;
3452       break;
3453     default:
3454       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3455         return MCDisassembler::Fail;
3456   }
3457 
3458   unsigned addrmode = fieldFromInstruction(Insn, 4, 2);
3459   addrmode |= fieldFromInstruction(Insn, 0, 4) << 2;
3460   addrmode |= fieldFromInstruction(Insn, 16, 4) << 6;
3461   if (!Check(S, DecodeT2AddrModeSOReg(Inst, addrmode, Address, Decoder)))
3462     return MCDisassembler::Fail;
3463 
3464   return S;
3465 }
3466 
3467 static DecodeStatus DecodeT2LoadImm8(MCInst &Inst, unsigned Insn,
3468                                 uint64_t Address, const void* Decoder) {
3469   DecodeStatus S = MCDisassembler::Success;
3470 
3471   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3472   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3473   unsigned U = fieldFromInstruction(Insn, 9, 1);
3474   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3475   imm |= (U << 8);
3476   imm |= (Rn << 9);
3477   unsigned add = fieldFromInstruction(Insn, 9, 1);
3478 
3479   const FeatureBitset &featureBits =
3480     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3481 
3482   bool hasMP = featureBits[ARM::FeatureMP];
3483   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3484 
3485   if (Rn == 15) {
3486     switch (Inst.getOpcode()) {
3487     case ARM::t2LDRi8:
3488       Inst.setOpcode(ARM::t2LDRpci);
3489       break;
3490     case ARM::t2LDRBi8:
3491       Inst.setOpcode(ARM::t2LDRBpci);
3492       break;
3493     case ARM::t2LDRSBi8:
3494       Inst.setOpcode(ARM::t2LDRSBpci);
3495       break;
3496     case ARM::t2LDRHi8:
3497       Inst.setOpcode(ARM::t2LDRHpci);
3498       break;
3499     case ARM::t2LDRSHi8:
3500       Inst.setOpcode(ARM::t2LDRSHpci);
3501       break;
3502     case ARM::t2PLDi8:
3503       Inst.setOpcode(ARM::t2PLDpci);
3504       break;
3505     case ARM::t2PLIi8:
3506       Inst.setOpcode(ARM::t2PLIpci);
3507       break;
3508     default:
3509       return MCDisassembler::Fail;
3510     }
3511     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3512   }
3513 
3514   if (Rt == 15) {
3515     switch (Inst.getOpcode()) {
3516     case ARM::t2LDRSHi8:
3517       return MCDisassembler::Fail;
3518     case ARM::t2LDRHi8:
3519       if (!add)
3520         Inst.setOpcode(ARM::t2PLDWi8);
3521       break;
3522     case ARM::t2LDRSBi8:
3523       Inst.setOpcode(ARM::t2PLIi8);
3524       break;
3525     default:
3526       break;
3527     }
3528   }
3529 
3530   switch (Inst.getOpcode()) {
3531   case ARM::t2PLDi8:
3532     break;
3533   case ARM::t2PLIi8:
3534     if (!hasV7Ops)
3535       return MCDisassembler::Fail;
3536     break;
3537   case ARM::t2PLDWi8:
3538       if (!hasV7Ops || !hasMP)
3539         return MCDisassembler::Fail;
3540       break;
3541   default:
3542     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3543       return MCDisassembler::Fail;
3544   }
3545 
3546   if (!Check(S, DecodeT2AddrModeImm8(Inst, imm, Address, Decoder)))
3547     return MCDisassembler::Fail;
3548   return S;
3549 }
3550 
3551 static DecodeStatus DecodeT2LoadImm12(MCInst &Inst, unsigned Insn,
3552                                 uint64_t Address, const void* Decoder) {
3553   DecodeStatus S = MCDisassembler::Success;
3554 
3555   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3556   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3557   unsigned imm = fieldFromInstruction(Insn, 0, 12);
3558   imm |= (Rn << 13);
3559 
3560   const FeatureBitset &featureBits =
3561     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3562 
3563   bool hasMP = featureBits[ARM::FeatureMP];
3564   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3565 
3566   if (Rn == 15) {
3567     switch (Inst.getOpcode()) {
3568     case ARM::t2LDRi12:
3569       Inst.setOpcode(ARM::t2LDRpci);
3570       break;
3571     case ARM::t2LDRHi12:
3572       Inst.setOpcode(ARM::t2LDRHpci);
3573       break;
3574     case ARM::t2LDRSHi12:
3575       Inst.setOpcode(ARM::t2LDRSHpci);
3576       break;
3577     case ARM::t2LDRBi12:
3578       Inst.setOpcode(ARM::t2LDRBpci);
3579       break;
3580     case ARM::t2LDRSBi12:
3581       Inst.setOpcode(ARM::t2LDRSBpci);
3582       break;
3583     case ARM::t2PLDi12:
3584       Inst.setOpcode(ARM::t2PLDpci);
3585       break;
3586     case ARM::t2PLIi12:
3587       Inst.setOpcode(ARM::t2PLIpci);
3588       break;
3589     default:
3590       return MCDisassembler::Fail;
3591     }
3592     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3593   }
3594 
3595   if (Rt == 15) {
3596     switch (Inst.getOpcode()) {
3597     case ARM::t2LDRSHi12:
3598       return MCDisassembler::Fail;
3599     case ARM::t2LDRHi12:
3600       Inst.setOpcode(ARM::t2PLDWi12);
3601       break;
3602     case ARM::t2LDRSBi12:
3603       Inst.setOpcode(ARM::t2PLIi12);
3604       break;
3605     default:
3606       break;
3607     }
3608   }
3609 
3610   switch (Inst.getOpcode()) {
3611   case ARM::t2PLDi12:
3612     break;
3613   case ARM::t2PLIi12:
3614     if (!hasV7Ops)
3615       return MCDisassembler::Fail;
3616     break;
3617   case ARM::t2PLDWi12:
3618       if (!hasV7Ops || !hasMP)
3619         return MCDisassembler::Fail;
3620       break;
3621   default:
3622     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3623       return MCDisassembler::Fail;
3624   }
3625 
3626   if (!Check(S, DecodeT2AddrModeImm12(Inst, imm, Address, Decoder)))
3627     return MCDisassembler::Fail;
3628   return S;
3629 }
3630 
3631 static DecodeStatus DecodeT2LoadT(MCInst &Inst, unsigned Insn,
3632                                 uint64_t Address, const void* Decoder) {
3633   DecodeStatus S = MCDisassembler::Success;
3634 
3635   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3636   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3637   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3638   imm |= (Rn << 9);
3639 
3640   if (Rn == 15) {
3641     switch (Inst.getOpcode()) {
3642     case ARM::t2LDRT:
3643       Inst.setOpcode(ARM::t2LDRpci);
3644       break;
3645     case ARM::t2LDRBT:
3646       Inst.setOpcode(ARM::t2LDRBpci);
3647       break;
3648     case ARM::t2LDRHT:
3649       Inst.setOpcode(ARM::t2LDRHpci);
3650       break;
3651     case ARM::t2LDRSBT:
3652       Inst.setOpcode(ARM::t2LDRSBpci);
3653       break;
3654     case ARM::t2LDRSHT:
3655       Inst.setOpcode(ARM::t2LDRSHpci);
3656       break;
3657     default:
3658       return MCDisassembler::Fail;
3659     }
3660     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3661   }
3662 
3663   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
3664     return MCDisassembler::Fail;
3665   if (!Check(S, DecodeT2AddrModeImm8(Inst, imm, Address, Decoder)))
3666     return MCDisassembler::Fail;
3667   return S;
3668 }
3669 
3670 static DecodeStatus DecodeT2LoadLabel(MCInst &Inst, unsigned Insn,
3671                                 uint64_t Address, const void* Decoder) {
3672   DecodeStatus S = MCDisassembler::Success;
3673 
3674   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3675   unsigned U = fieldFromInstruction(Insn, 23, 1);
3676   int imm = fieldFromInstruction(Insn, 0, 12);
3677 
3678   const FeatureBitset &featureBits =
3679     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3680 
3681   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3682 
3683   if (Rt == 15) {
3684     switch (Inst.getOpcode()) {
3685       case ARM::t2LDRBpci:
3686       case ARM::t2LDRHpci:
3687         Inst.setOpcode(ARM::t2PLDpci);
3688         break;
3689       case ARM::t2LDRSBpci:
3690         Inst.setOpcode(ARM::t2PLIpci);
3691         break;
3692       case ARM::t2LDRSHpci:
3693         return MCDisassembler::Fail;
3694       default:
3695         break;
3696     }
3697   }
3698 
3699   switch(Inst.getOpcode()) {
3700   case ARM::t2PLDpci:
3701     break;
3702   case ARM::t2PLIpci:
3703     if (!hasV7Ops)
3704       return MCDisassembler::Fail;
3705     break;
3706   default:
3707     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3708       return MCDisassembler::Fail;
3709   }
3710 
3711   if (!U) {
3712     // Special case for #-0.
3713     if (imm == 0)
3714       imm = INT32_MIN;
3715     else
3716       imm = -imm;
3717   }
3718   Inst.addOperand(MCOperand::createImm(imm));
3719 
3720   return S;
3721 }
3722 
3723 static DecodeStatus DecodeT2Imm8S4(MCInst &Inst, unsigned Val,
3724                            uint64_t Address, const void *Decoder) {
3725   if (Val == 0)
3726     Inst.addOperand(MCOperand::createImm(INT32_MIN));
3727   else {
3728     int imm = Val & 0xFF;
3729 
3730     if (!(Val & 0x100)) imm *= -1;
3731     Inst.addOperand(MCOperand::createImm(imm * 4));
3732   }
3733 
3734   return MCDisassembler::Success;
3735 }
3736 
3737 static DecodeStatus DecodeT2AddrModeImm8s4(MCInst &Inst, unsigned Val,
3738                                    uint64_t Address, const void *Decoder) {
3739   DecodeStatus S = MCDisassembler::Success;
3740 
3741   unsigned Rn = fieldFromInstruction(Val, 9, 4);
3742   unsigned imm = fieldFromInstruction(Val, 0, 9);
3743 
3744   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3745     return MCDisassembler::Fail;
3746   if (!Check(S, DecodeT2Imm8S4(Inst, imm, Address, Decoder)))
3747     return MCDisassembler::Fail;
3748 
3749   return S;
3750 }
3751 
3752 static DecodeStatus DecodeT2AddrModeImm0_1020s4(MCInst &Inst,unsigned Val,
3753                                    uint64_t Address, const void *Decoder) {
3754   DecodeStatus S = MCDisassembler::Success;
3755 
3756   unsigned Rn = fieldFromInstruction(Val, 8, 4);
3757   unsigned imm = fieldFromInstruction(Val, 0, 8);
3758 
3759   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
3760     return MCDisassembler::Fail;
3761 
3762   Inst.addOperand(MCOperand::createImm(imm));
3763 
3764   return S;
3765 }
3766 
3767 static DecodeStatus DecodeT2Imm8(MCInst &Inst, unsigned Val,
3768                          uint64_t Address, const void *Decoder) {
3769   int imm = Val & 0xFF;
3770   if (Val == 0)
3771     imm = INT32_MIN;
3772   else if (!(Val & 0x100))
3773     imm *= -1;
3774   Inst.addOperand(MCOperand::createImm(imm));
3775 
3776   return MCDisassembler::Success;
3777 }
3778 
3779 static DecodeStatus DecodeT2AddrModeImm8(MCInst &Inst, unsigned Val,
3780                                  uint64_t Address, const void *Decoder) {
3781   DecodeStatus S = MCDisassembler::Success;
3782 
3783   unsigned Rn = fieldFromInstruction(Val, 9, 4);
3784   unsigned imm = fieldFromInstruction(Val, 0, 9);
3785 
3786   // Thumb stores cannot use PC as dest register.
3787   switch (Inst.getOpcode()) {
3788   case ARM::t2STRT:
3789   case ARM::t2STRBT:
3790   case ARM::t2STRHT:
3791   case ARM::t2STRi8:
3792   case ARM::t2STRHi8:
3793   case ARM::t2STRBi8:
3794     if (Rn == 15)
3795       return MCDisassembler::Fail;
3796     break;
3797   default:
3798     break;
3799   }
3800 
3801   // Some instructions always use an additive offset.
3802   switch (Inst.getOpcode()) {
3803     case ARM::t2LDRT:
3804     case ARM::t2LDRBT:
3805     case ARM::t2LDRHT:
3806     case ARM::t2LDRSBT:
3807     case ARM::t2LDRSHT:
3808     case ARM::t2STRT:
3809     case ARM::t2STRBT:
3810     case ARM::t2STRHT:
3811       imm |= 0x100;
3812       break;
3813     default:
3814       break;
3815   }
3816 
3817   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3818     return MCDisassembler::Fail;
3819   if (!Check(S, DecodeT2Imm8(Inst, imm, Address, Decoder)))
3820     return MCDisassembler::Fail;
3821 
3822   return S;
3823 }
3824 
3825 static DecodeStatus DecodeT2LdStPre(MCInst &Inst, unsigned Insn,
3826                                     uint64_t Address, const void *Decoder) {
3827   DecodeStatus S = MCDisassembler::Success;
3828 
3829   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3830   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3831   unsigned addr = fieldFromInstruction(Insn, 0, 8);
3832   addr |= fieldFromInstruction(Insn, 9, 1) << 8;
3833   addr |= Rn << 9;
3834   unsigned load = fieldFromInstruction(Insn, 20, 1);
3835 
3836   if (Rn == 15) {
3837     switch (Inst.getOpcode()) {
3838     case ARM::t2LDR_PRE:
3839     case ARM::t2LDR_POST:
3840       Inst.setOpcode(ARM::t2LDRpci);
3841       break;
3842     case ARM::t2LDRB_PRE:
3843     case ARM::t2LDRB_POST:
3844       Inst.setOpcode(ARM::t2LDRBpci);
3845       break;
3846     case ARM::t2LDRH_PRE:
3847     case ARM::t2LDRH_POST:
3848       Inst.setOpcode(ARM::t2LDRHpci);
3849       break;
3850     case ARM::t2LDRSB_PRE:
3851     case ARM::t2LDRSB_POST:
3852       if (Rt == 15)
3853         Inst.setOpcode(ARM::t2PLIpci);
3854       else
3855         Inst.setOpcode(ARM::t2LDRSBpci);
3856       break;
3857     case ARM::t2LDRSH_PRE:
3858     case ARM::t2LDRSH_POST:
3859       Inst.setOpcode(ARM::t2LDRSHpci);
3860       break;
3861     default:
3862       return MCDisassembler::Fail;
3863     }
3864     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3865   }
3866 
3867   if (!load) {
3868     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3869       return MCDisassembler::Fail;
3870   }
3871 
3872   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3873     return MCDisassembler::Fail;
3874 
3875   if (load) {
3876     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3877       return MCDisassembler::Fail;
3878   }
3879 
3880   if (!Check(S, DecodeT2AddrModeImm8(Inst, addr, Address, Decoder)))
3881     return MCDisassembler::Fail;
3882 
3883   return S;
3884 }
3885 
3886 static DecodeStatus DecodeT2AddrModeImm12(MCInst &Inst, unsigned Val,
3887                                   uint64_t Address, const void *Decoder) {
3888   DecodeStatus S = MCDisassembler::Success;
3889 
3890   unsigned Rn = fieldFromInstruction(Val, 13, 4);
3891   unsigned imm = fieldFromInstruction(Val, 0, 12);
3892 
3893   // Thumb stores cannot use PC as dest register.
3894   switch (Inst.getOpcode()) {
3895   case ARM::t2STRi12:
3896   case ARM::t2STRBi12:
3897   case ARM::t2STRHi12:
3898     if (Rn == 15)
3899       return MCDisassembler::Fail;
3900     break;
3901   default:
3902     break;
3903   }
3904 
3905   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3906     return MCDisassembler::Fail;
3907   Inst.addOperand(MCOperand::createImm(imm));
3908 
3909   return S;
3910 }
3911 
3912 static DecodeStatus DecodeThumbAddSPImm(MCInst &Inst, uint16_t Insn,
3913                                 uint64_t Address, const void *Decoder) {
3914   unsigned imm = fieldFromInstruction(Insn, 0, 7);
3915 
3916   Inst.addOperand(MCOperand::createReg(ARM::SP));
3917   Inst.addOperand(MCOperand::createReg(ARM::SP));
3918   Inst.addOperand(MCOperand::createImm(imm));
3919 
3920   return MCDisassembler::Success;
3921 }
3922 
3923 static DecodeStatus DecodeThumbAddSPReg(MCInst &Inst, uint16_t Insn,
3924                                 uint64_t Address, const void *Decoder) {
3925   DecodeStatus S = MCDisassembler::Success;
3926 
3927   if (Inst.getOpcode() == ARM::tADDrSP) {
3928     unsigned Rdm = fieldFromInstruction(Insn, 0, 3);
3929     Rdm |= fieldFromInstruction(Insn, 7, 1) << 3;
3930 
3931     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
3932     return MCDisassembler::Fail;
3933     Inst.addOperand(MCOperand::createReg(ARM::SP));
3934     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
3935     return MCDisassembler::Fail;
3936   } else if (Inst.getOpcode() == ARM::tADDspr) {
3937     unsigned Rm = fieldFromInstruction(Insn, 3, 4);
3938 
3939     Inst.addOperand(MCOperand::createReg(ARM::SP));
3940     Inst.addOperand(MCOperand::createReg(ARM::SP));
3941     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3942     return MCDisassembler::Fail;
3943   }
3944 
3945   return S;
3946 }
3947 
3948 static DecodeStatus DecodeThumbCPS(MCInst &Inst, uint16_t Insn,
3949                            uint64_t Address, const void *Decoder) {
3950   unsigned imod = fieldFromInstruction(Insn, 4, 1) | 0x2;
3951   unsigned flags = fieldFromInstruction(Insn, 0, 3);
3952 
3953   Inst.addOperand(MCOperand::createImm(imod));
3954   Inst.addOperand(MCOperand::createImm(flags));
3955 
3956   return MCDisassembler::Success;
3957 }
3958 
3959 static DecodeStatus DecodePostIdxReg(MCInst &Inst, unsigned Insn,
3960                              uint64_t Address, const void *Decoder) {
3961   DecodeStatus S = MCDisassembler::Success;
3962   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3963   unsigned add = fieldFromInstruction(Insn, 4, 1);
3964 
3965   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
3966     return MCDisassembler::Fail;
3967   Inst.addOperand(MCOperand::createImm(add));
3968 
3969   return S;
3970 }
3971 
3972 static DecodeStatus DecodeThumbBLXOffset(MCInst &Inst, unsigned Val,
3973                                  uint64_t Address, const void *Decoder) {
3974   // Val is passed in as S:J1:J2:imm10H:imm10L:'0'
3975   // Note only one trailing zero not two.  Also the J1 and J2 values are from
3976   // the encoded instruction.  So here change to I1 and I2 values via:
3977   // I1 = NOT(J1 EOR S);
3978   // I2 = NOT(J2 EOR S);
3979   // and build the imm32 with two trailing zeros as documented:
3980   // imm32 = SignExtend(S:I1:I2:imm10H:imm10L:'00', 32);
3981   unsigned S = (Val >> 23) & 1;
3982   unsigned J1 = (Val >> 22) & 1;
3983   unsigned J2 = (Val >> 21) & 1;
3984   unsigned I1 = !(J1 ^ S);
3985   unsigned I2 = !(J2 ^ S);
3986   unsigned tmp = (Val & ~0x600000) | (I1 << 22) | (I2 << 21);
3987   int imm32 = SignExtend32<25>(tmp << 1);
3988 
3989   if (!tryAddingSymbolicOperand(Address,
3990                                 (Address & ~2u) + imm32 + 4,
3991                                 true, 4, Inst, Decoder))
3992     Inst.addOperand(MCOperand::createImm(imm32));
3993   return MCDisassembler::Success;
3994 }
3995 
3996 static DecodeStatus DecodeCoprocessor(MCInst &Inst, unsigned Val,
3997                               uint64_t Address, const void *Decoder) {
3998   if (Val == 0xA || Val == 0xB)
3999     return MCDisassembler::Fail;
4000 
4001   const FeatureBitset &featureBits =
4002     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4003 
4004   if (featureBits[ARM::HasV8Ops] && !(Val == 14 || Val == 15))
4005     return MCDisassembler::Fail;
4006 
4007   Inst.addOperand(MCOperand::createImm(Val));
4008   return MCDisassembler::Success;
4009 }
4010 
4011 static DecodeStatus
4012 DecodeThumbTableBranch(MCInst &Inst, unsigned Insn,
4013                        uint64_t Address, const void *Decoder) {
4014   DecodeStatus S = MCDisassembler::Success;
4015 
4016   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4017   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4018 
4019   if (Rn == ARM::SP) S = MCDisassembler::SoftFail;
4020   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4021     return MCDisassembler::Fail;
4022   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
4023     return MCDisassembler::Fail;
4024   return S;
4025 }
4026 
4027 static DecodeStatus
4028 DecodeThumb2BCCInstruction(MCInst &Inst, unsigned Insn,
4029                            uint64_t Address, const void *Decoder) {
4030   DecodeStatus S = MCDisassembler::Success;
4031 
4032   unsigned pred = fieldFromInstruction(Insn, 22, 4);
4033   if (pred == 0xE || pred == 0xF) {
4034     unsigned opc = fieldFromInstruction(Insn, 4, 28);
4035     switch (opc) {
4036       default:
4037         return MCDisassembler::Fail;
4038       case 0xf3bf8f4:
4039         Inst.setOpcode(ARM::t2DSB);
4040         break;
4041       case 0xf3bf8f5:
4042         Inst.setOpcode(ARM::t2DMB);
4043         break;
4044       case 0xf3bf8f6:
4045         Inst.setOpcode(ARM::t2ISB);
4046         break;
4047     }
4048 
4049     unsigned imm = fieldFromInstruction(Insn, 0, 4);
4050     return DecodeMemBarrierOption(Inst, imm, Address, Decoder);
4051   }
4052 
4053   unsigned brtarget = fieldFromInstruction(Insn, 0, 11) << 1;
4054   brtarget |= fieldFromInstruction(Insn, 11, 1) << 19;
4055   brtarget |= fieldFromInstruction(Insn, 13, 1) << 18;
4056   brtarget |= fieldFromInstruction(Insn, 16, 6) << 12;
4057   brtarget |= fieldFromInstruction(Insn, 26, 1) << 20;
4058 
4059   if (!Check(S, DecodeT2BROperand(Inst, brtarget, Address, Decoder)))
4060     return MCDisassembler::Fail;
4061   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4062     return MCDisassembler::Fail;
4063 
4064   return S;
4065 }
4066 
4067 // Decode a shifted immediate operand.  These basically consist
4068 // of an 8-bit value, and a 4-bit directive that specifies either
4069 // a splat operation or a rotation.
4070 static DecodeStatus DecodeT2SOImm(MCInst &Inst, unsigned Val,
4071                           uint64_t Address, const void *Decoder) {
4072   unsigned ctrl = fieldFromInstruction(Val, 10, 2);
4073   if (ctrl == 0) {
4074     unsigned byte = fieldFromInstruction(Val, 8, 2);
4075     unsigned imm = fieldFromInstruction(Val, 0, 8);
4076     switch (byte) {
4077       case 0:
4078         Inst.addOperand(MCOperand::createImm(imm));
4079         break;
4080       case 1:
4081         Inst.addOperand(MCOperand::createImm((imm << 16) | imm));
4082         break;
4083       case 2:
4084         Inst.addOperand(MCOperand::createImm((imm << 24) | (imm << 8)));
4085         break;
4086       case 3:
4087         Inst.addOperand(MCOperand::createImm((imm << 24) | (imm << 16) |
4088                                              (imm << 8)  |  imm));
4089         break;
4090     }
4091   } else {
4092     unsigned unrot = fieldFromInstruction(Val, 0, 7) | 0x80;
4093     unsigned rot = fieldFromInstruction(Val, 7, 5);
4094     unsigned imm = (unrot >> rot) | (unrot << ((32-rot)&31));
4095     Inst.addOperand(MCOperand::createImm(imm));
4096   }
4097 
4098   return MCDisassembler::Success;
4099 }
4100 
4101 static DecodeStatus
4102 DecodeThumbBCCTargetOperand(MCInst &Inst, unsigned Val,
4103                             uint64_t Address, const void *Decoder) {
4104   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<9>(Val<<1) + 4,
4105                                 true, 2, Inst, Decoder))
4106     Inst.addOperand(MCOperand::createImm(SignExtend32<9>(Val << 1)));
4107   return MCDisassembler::Success;
4108 }
4109 
4110 static DecodeStatus DecodeThumbBLTargetOperand(MCInst &Inst, unsigned Val,
4111                                                uint64_t Address,
4112                                                const void *Decoder) {
4113   // Val is passed in as S:J1:J2:imm10:imm11
4114   // Note no trailing zero after imm11.  Also the J1 and J2 values are from
4115   // the encoded instruction.  So here change to I1 and I2 values via:
4116   // I1 = NOT(J1 EOR S);
4117   // I2 = NOT(J2 EOR S);
4118   // and build the imm32 with one trailing zero as documented:
4119   // imm32 = SignExtend(S:I1:I2:imm10:imm11:'0', 32);
4120   unsigned S = (Val >> 23) & 1;
4121   unsigned J1 = (Val >> 22) & 1;
4122   unsigned J2 = (Val >> 21) & 1;
4123   unsigned I1 = !(J1 ^ S);
4124   unsigned I2 = !(J2 ^ S);
4125   unsigned tmp = (Val & ~0x600000) | (I1 << 22) | (I2 << 21);
4126   int imm32 = SignExtend32<25>(tmp << 1);
4127 
4128   if (!tryAddingSymbolicOperand(Address, Address + imm32 + 4,
4129                                 true, 4, Inst, Decoder))
4130     Inst.addOperand(MCOperand::createImm(imm32));
4131   return MCDisassembler::Success;
4132 }
4133 
4134 static DecodeStatus DecodeMemBarrierOption(MCInst &Inst, unsigned Val,
4135                                    uint64_t Address, const void *Decoder) {
4136   if (Val & ~0xf)
4137     return MCDisassembler::Fail;
4138 
4139   Inst.addOperand(MCOperand::createImm(Val));
4140   return MCDisassembler::Success;
4141 }
4142 
4143 static DecodeStatus DecodeInstSyncBarrierOption(MCInst &Inst, unsigned Val,
4144                                         uint64_t Address, const void *Decoder) {
4145   if (Val & ~0xf)
4146     return MCDisassembler::Fail;
4147 
4148   Inst.addOperand(MCOperand::createImm(Val));
4149   return MCDisassembler::Success;
4150 }
4151 
4152 static DecodeStatus DecodeMSRMask(MCInst &Inst, unsigned Val,
4153                           uint64_t Address, const void *Decoder) {
4154   DecodeStatus S = MCDisassembler::Success;
4155   const FeatureBitset &FeatureBits =
4156     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4157 
4158   if (FeatureBits[ARM::FeatureMClass]) {
4159     unsigned ValLow = Val & 0xff;
4160 
4161     // Validate the SYSm value first.
4162     switch (ValLow) {
4163     case  0: // apsr
4164     case  1: // iapsr
4165     case  2: // eapsr
4166     case  3: // xpsr
4167     case  5: // ipsr
4168     case  6: // epsr
4169     case  7: // iepsr
4170     case  8: // msp
4171     case  9: // psp
4172     case 16: // primask
4173     case 20: // control
4174       break;
4175     case 17: // basepri
4176     case 18: // basepri_max
4177     case 19: // faultmask
4178       if (!(FeatureBits[ARM::HasV7Ops]))
4179         // Values basepri, basepri_max and faultmask are only valid for v7m.
4180         return MCDisassembler::Fail;
4181       break;
4182     case 0x8a: // msplim_ns
4183     case 0x8b: // psplim_ns
4184     case 0x91: // basepri_ns
4185     case 0x93: // faultmask_ns
4186       if (!(FeatureBits[ARM::HasV8MMainlineOps]))
4187         return MCDisassembler::Fail;
4188       LLVM_FALLTHROUGH;
4189     case 10:   // msplim
4190     case 11:   // psplim
4191     case 0x88: // msp_ns
4192     case 0x89: // psp_ns
4193     case 0x90: // primask_ns
4194     case 0x94: // control_ns
4195     case 0x98: // sp_ns
4196       if (!(FeatureBits[ARM::Feature8MSecExt]))
4197         return MCDisassembler::Fail;
4198       break;
4199     default:
4200       // Architecturally defined as unpredictable
4201       S = MCDisassembler::SoftFail;
4202       break;
4203     }
4204 
4205     if (Inst.getOpcode() == ARM::t2MSR_M) {
4206       unsigned Mask = fieldFromInstruction(Val, 10, 2);
4207       if (!(FeatureBits[ARM::HasV7Ops])) {
4208         // The ARMv6-M MSR bits {11-10} can be only 0b10, other values are
4209         // unpredictable.
4210         if (Mask != 2)
4211           S = MCDisassembler::SoftFail;
4212       }
4213       else {
4214         // The ARMv7-M architecture stores an additional 2-bit mask value in
4215         // MSR bits {11-10}. The mask is used only with apsr, iapsr, eapsr and
4216         // xpsr, it has to be 0b10 in other cases. Bit mask{1} indicates if
4217         // the NZCVQ bits should be moved by the instruction. Bit mask{0}
4218         // indicates the move for the GE{3:0} bits, the mask{0} bit can be set
4219         // only if the processor includes the DSP extension.
4220         if (Mask == 0 || (Mask != 2 && ValLow > 3) ||
4221             (!(FeatureBits[ARM::FeatureDSP]) && (Mask & 1)))
4222           S = MCDisassembler::SoftFail;
4223       }
4224     }
4225   } else {
4226     // A/R class
4227     if (Val == 0)
4228       return MCDisassembler::Fail;
4229   }
4230   Inst.addOperand(MCOperand::createImm(Val));
4231   return S;
4232 }
4233 
4234 static DecodeStatus DecodeBankedReg(MCInst &Inst, unsigned Val,
4235                                     uint64_t Address, const void *Decoder) {
4236   unsigned R = fieldFromInstruction(Val, 5, 1);
4237   unsigned SysM = fieldFromInstruction(Val, 0, 5);
4238 
4239   // The table of encodings for these banked registers comes from B9.2.3 of the
4240   // ARM ARM. There are patterns, but nothing regular enough to make this logic
4241   // neater. So by fiat, these values are UNPREDICTABLE:
4242   if (!ARMBankedReg::lookupBankedRegByEncoding((R << 5) | SysM))
4243     return MCDisassembler::Fail;
4244 
4245   Inst.addOperand(MCOperand::createImm(Val));
4246   return MCDisassembler::Success;
4247 }
4248 
4249 static DecodeStatus DecodeDoubleRegLoad(MCInst &Inst, unsigned Insn,
4250                                         uint64_t Address, const void *Decoder) {
4251   DecodeStatus S = MCDisassembler::Success;
4252 
4253   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4254   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4255   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4256 
4257   if (Rn == 0xF)
4258     S = MCDisassembler::SoftFail;
4259 
4260   if (!Check(S, DecodeGPRPairRegisterClass(Inst, Rt, Address, Decoder)))
4261     return MCDisassembler::Fail;
4262   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4263     return MCDisassembler::Fail;
4264   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4265     return MCDisassembler::Fail;
4266 
4267   return S;
4268 }
4269 
4270 static DecodeStatus DecodeDoubleRegStore(MCInst &Inst, unsigned Insn,
4271                                          uint64_t Address,
4272                                          const void *Decoder) {
4273   DecodeStatus S = MCDisassembler::Success;
4274 
4275   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4276   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
4277   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4278   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4279 
4280   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
4281     return MCDisassembler::Fail;
4282 
4283   if (Rn == 0xF || Rd == Rn || Rd == Rt || Rd == Rt+1)
4284     S = MCDisassembler::SoftFail;
4285 
4286   if (!Check(S, DecodeGPRPairRegisterClass(Inst, Rt, Address, Decoder)))
4287     return MCDisassembler::Fail;
4288   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4289     return MCDisassembler::Fail;
4290   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4291     return MCDisassembler::Fail;
4292 
4293   return S;
4294 }
4295 
4296 static DecodeStatus DecodeLDRPreImm(MCInst &Inst, unsigned Insn,
4297                             uint64_t Address, const void *Decoder) {
4298   DecodeStatus S = MCDisassembler::Success;
4299 
4300   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4301   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4302   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4303   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4304   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4305   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4306 
4307   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4308 
4309   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4310     return MCDisassembler::Fail;
4311   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4312     return MCDisassembler::Fail;
4313   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
4314     return MCDisassembler::Fail;
4315   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4316     return MCDisassembler::Fail;
4317 
4318   return S;
4319 }
4320 
4321 static DecodeStatus DecodeLDRPreReg(MCInst &Inst, unsigned Insn,
4322                             uint64_t Address, const void *Decoder) {
4323   DecodeStatus S = MCDisassembler::Success;
4324 
4325   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4326   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4327   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4328   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4329   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4330   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4331   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4332 
4333   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4334   if (Rm == 0xF) S = MCDisassembler::SoftFail;
4335 
4336   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4337     return MCDisassembler::Fail;
4338   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4339     return MCDisassembler::Fail;
4340   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
4341     return MCDisassembler::Fail;
4342   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4343     return MCDisassembler::Fail;
4344 
4345   return S;
4346 }
4347 
4348 static DecodeStatus DecodeSTRPreImm(MCInst &Inst, unsigned Insn,
4349                             uint64_t Address, const void *Decoder) {
4350   DecodeStatus S = MCDisassembler::Success;
4351 
4352   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4353   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4354   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4355   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4356   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4357   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4358 
4359   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4360 
4361   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4362     return MCDisassembler::Fail;
4363   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4364     return MCDisassembler::Fail;
4365   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
4366     return MCDisassembler::Fail;
4367   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4368     return MCDisassembler::Fail;
4369 
4370   return S;
4371 }
4372 
4373 static DecodeStatus DecodeSTRPreReg(MCInst &Inst, unsigned Insn,
4374                             uint64_t Address, const void *Decoder) {
4375   DecodeStatus S = MCDisassembler::Success;
4376 
4377   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4378   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4379   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4380   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4381   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4382   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4383 
4384   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4385 
4386   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4387     return MCDisassembler::Fail;
4388   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4389     return MCDisassembler::Fail;
4390   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
4391     return MCDisassembler::Fail;
4392   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4393     return MCDisassembler::Fail;
4394 
4395   return S;
4396 }
4397 
4398 static DecodeStatus DecodeVLD1LN(MCInst &Inst, unsigned Insn,
4399                          uint64_t Address, const void *Decoder) {
4400   DecodeStatus S = MCDisassembler::Success;
4401 
4402   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4403   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4404   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4405   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4406   unsigned size = fieldFromInstruction(Insn, 10, 2);
4407 
4408   unsigned align = 0;
4409   unsigned index = 0;
4410   switch (size) {
4411     default:
4412       return MCDisassembler::Fail;
4413     case 0:
4414       if (fieldFromInstruction(Insn, 4, 1))
4415         return MCDisassembler::Fail; // UNDEFINED
4416       index = fieldFromInstruction(Insn, 5, 3);
4417       break;
4418     case 1:
4419       if (fieldFromInstruction(Insn, 5, 1))
4420         return MCDisassembler::Fail; // UNDEFINED
4421       index = fieldFromInstruction(Insn, 6, 2);
4422       if (fieldFromInstruction(Insn, 4, 1))
4423         align = 2;
4424       break;
4425     case 2:
4426       if (fieldFromInstruction(Insn, 6, 1))
4427         return MCDisassembler::Fail; // UNDEFINED
4428       index = fieldFromInstruction(Insn, 7, 1);
4429 
4430       switch (fieldFromInstruction(Insn, 4, 2)) {
4431         case 0 :
4432           align = 0; break;
4433         case 3:
4434           align = 4; break;
4435         default:
4436           return MCDisassembler::Fail;
4437       }
4438       break;
4439   }
4440 
4441   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4442     return MCDisassembler::Fail;
4443   if (Rm != 0xF) { // Writeback
4444     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4445       return MCDisassembler::Fail;
4446   }
4447   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4448     return MCDisassembler::Fail;
4449   Inst.addOperand(MCOperand::createImm(align));
4450   if (Rm != 0xF) {
4451     if (Rm != 0xD) {
4452       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4453         return MCDisassembler::Fail;
4454     } else
4455       Inst.addOperand(MCOperand::createReg(0));
4456   }
4457 
4458   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4459     return MCDisassembler::Fail;
4460   Inst.addOperand(MCOperand::createImm(index));
4461 
4462   return S;
4463 }
4464 
4465 static DecodeStatus DecodeVST1LN(MCInst &Inst, unsigned Insn,
4466                          uint64_t Address, const void *Decoder) {
4467   DecodeStatus S = MCDisassembler::Success;
4468 
4469   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4470   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4471   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4472   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4473   unsigned size = fieldFromInstruction(Insn, 10, 2);
4474 
4475   unsigned align = 0;
4476   unsigned index = 0;
4477   switch (size) {
4478     default:
4479       return MCDisassembler::Fail;
4480     case 0:
4481       if (fieldFromInstruction(Insn, 4, 1))
4482         return MCDisassembler::Fail; // UNDEFINED
4483       index = fieldFromInstruction(Insn, 5, 3);
4484       break;
4485     case 1:
4486       if (fieldFromInstruction(Insn, 5, 1))
4487         return MCDisassembler::Fail; // UNDEFINED
4488       index = fieldFromInstruction(Insn, 6, 2);
4489       if (fieldFromInstruction(Insn, 4, 1))
4490         align = 2;
4491       break;
4492     case 2:
4493       if (fieldFromInstruction(Insn, 6, 1))
4494         return MCDisassembler::Fail; // UNDEFINED
4495       index = fieldFromInstruction(Insn, 7, 1);
4496 
4497       switch (fieldFromInstruction(Insn, 4, 2)) {
4498         case 0:
4499           align = 0; break;
4500         case 3:
4501           align = 4; break;
4502         default:
4503           return MCDisassembler::Fail;
4504       }
4505       break;
4506   }
4507 
4508   if (Rm != 0xF) { // Writeback
4509     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4510     return MCDisassembler::Fail;
4511   }
4512   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4513     return MCDisassembler::Fail;
4514   Inst.addOperand(MCOperand::createImm(align));
4515   if (Rm != 0xF) {
4516     if (Rm != 0xD) {
4517       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4518     return MCDisassembler::Fail;
4519     } else
4520       Inst.addOperand(MCOperand::createReg(0));
4521   }
4522 
4523   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4524     return MCDisassembler::Fail;
4525   Inst.addOperand(MCOperand::createImm(index));
4526 
4527   return S;
4528 }
4529 
4530 static DecodeStatus DecodeVLD2LN(MCInst &Inst, unsigned Insn,
4531                          uint64_t Address, const void *Decoder) {
4532   DecodeStatus S = MCDisassembler::Success;
4533 
4534   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4535   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4536   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4537   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4538   unsigned size = fieldFromInstruction(Insn, 10, 2);
4539 
4540   unsigned align = 0;
4541   unsigned index = 0;
4542   unsigned inc = 1;
4543   switch (size) {
4544     default:
4545       return MCDisassembler::Fail;
4546     case 0:
4547       index = fieldFromInstruction(Insn, 5, 3);
4548       if (fieldFromInstruction(Insn, 4, 1))
4549         align = 2;
4550       break;
4551     case 1:
4552       index = fieldFromInstruction(Insn, 6, 2);
4553       if (fieldFromInstruction(Insn, 4, 1))
4554         align = 4;
4555       if (fieldFromInstruction(Insn, 5, 1))
4556         inc = 2;
4557       break;
4558     case 2:
4559       if (fieldFromInstruction(Insn, 5, 1))
4560         return MCDisassembler::Fail; // UNDEFINED
4561       index = fieldFromInstruction(Insn, 7, 1);
4562       if (fieldFromInstruction(Insn, 4, 1) != 0)
4563         align = 8;
4564       if (fieldFromInstruction(Insn, 6, 1))
4565         inc = 2;
4566       break;
4567   }
4568 
4569   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4570     return MCDisassembler::Fail;
4571   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4572     return MCDisassembler::Fail;
4573   if (Rm != 0xF) { // Writeback
4574     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4575       return MCDisassembler::Fail;
4576   }
4577   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4578     return MCDisassembler::Fail;
4579   Inst.addOperand(MCOperand::createImm(align));
4580   if (Rm != 0xF) {
4581     if (Rm != 0xD) {
4582       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4583         return MCDisassembler::Fail;
4584     } else
4585       Inst.addOperand(MCOperand::createReg(0));
4586   }
4587 
4588   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4589     return MCDisassembler::Fail;
4590   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4591     return MCDisassembler::Fail;
4592   Inst.addOperand(MCOperand::createImm(index));
4593 
4594   return S;
4595 }
4596 
4597 static DecodeStatus DecodeVST2LN(MCInst &Inst, unsigned Insn,
4598                          uint64_t Address, const void *Decoder) {
4599   DecodeStatus S = MCDisassembler::Success;
4600 
4601   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4602   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4603   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4604   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4605   unsigned size = fieldFromInstruction(Insn, 10, 2);
4606 
4607   unsigned align = 0;
4608   unsigned index = 0;
4609   unsigned inc = 1;
4610   switch (size) {
4611     default:
4612       return MCDisassembler::Fail;
4613     case 0:
4614       index = fieldFromInstruction(Insn, 5, 3);
4615       if (fieldFromInstruction(Insn, 4, 1))
4616         align = 2;
4617       break;
4618     case 1:
4619       index = fieldFromInstruction(Insn, 6, 2);
4620       if (fieldFromInstruction(Insn, 4, 1))
4621         align = 4;
4622       if (fieldFromInstruction(Insn, 5, 1))
4623         inc = 2;
4624       break;
4625     case 2:
4626       if (fieldFromInstruction(Insn, 5, 1))
4627         return MCDisassembler::Fail; // UNDEFINED
4628       index = fieldFromInstruction(Insn, 7, 1);
4629       if (fieldFromInstruction(Insn, 4, 1) != 0)
4630         align = 8;
4631       if (fieldFromInstruction(Insn, 6, 1))
4632         inc = 2;
4633       break;
4634   }
4635 
4636   if (Rm != 0xF) { // Writeback
4637     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4638       return MCDisassembler::Fail;
4639   }
4640   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4641     return MCDisassembler::Fail;
4642   Inst.addOperand(MCOperand::createImm(align));
4643   if (Rm != 0xF) {
4644     if (Rm != 0xD) {
4645       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4646         return MCDisassembler::Fail;
4647     } else
4648       Inst.addOperand(MCOperand::createReg(0));
4649   }
4650 
4651   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4652     return MCDisassembler::Fail;
4653   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4654     return MCDisassembler::Fail;
4655   Inst.addOperand(MCOperand::createImm(index));
4656 
4657   return S;
4658 }
4659 
4660 static DecodeStatus DecodeVLD3LN(MCInst &Inst, unsigned Insn,
4661                          uint64_t Address, const void *Decoder) {
4662   DecodeStatus S = MCDisassembler::Success;
4663 
4664   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4665   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4666   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4667   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4668   unsigned size = fieldFromInstruction(Insn, 10, 2);
4669 
4670   unsigned align = 0;
4671   unsigned index = 0;
4672   unsigned inc = 1;
4673   switch (size) {
4674     default:
4675       return MCDisassembler::Fail;
4676     case 0:
4677       if (fieldFromInstruction(Insn, 4, 1))
4678         return MCDisassembler::Fail; // UNDEFINED
4679       index = fieldFromInstruction(Insn, 5, 3);
4680       break;
4681     case 1:
4682       if (fieldFromInstruction(Insn, 4, 1))
4683         return MCDisassembler::Fail; // UNDEFINED
4684       index = fieldFromInstruction(Insn, 6, 2);
4685       if (fieldFromInstruction(Insn, 5, 1))
4686         inc = 2;
4687       break;
4688     case 2:
4689       if (fieldFromInstruction(Insn, 4, 2))
4690         return MCDisassembler::Fail; // UNDEFINED
4691       index = fieldFromInstruction(Insn, 7, 1);
4692       if (fieldFromInstruction(Insn, 6, 1))
4693         inc = 2;
4694       break;
4695   }
4696 
4697   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4698     return MCDisassembler::Fail;
4699   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4700     return MCDisassembler::Fail;
4701   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
4702     return MCDisassembler::Fail;
4703 
4704   if (Rm != 0xF) { // Writeback
4705     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4706     return MCDisassembler::Fail;
4707   }
4708   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4709     return MCDisassembler::Fail;
4710   Inst.addOperand(MCOperand::createImm(align));
4711   if (Rm != 0xF) {
4712     if (Rm != 0xD) {
4713       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4714     return MCDisassembler::Fail;
4715     } else
4716       Inst.addOperand(MCOperand::createReg(0));
4717   }
4718 
4719   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4720     return MCDisassembler::Fail;
4721   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4722     return MCDisassembler::Fail;
4723   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
4724     return MCDisassembler::Fail;
4725   Inst.addOperand(MCOperand::createImm(index));
4726 
4727   return S;
4728 }
4729 
4730 static DecodeStatus DecodeVST3LN(MCInst &Inst, unsigned Insn,
4731                          uint64_t Address, const void *Decoder) {
4732   DecodeStatus S = MCDisassembler::Success;
4733 
4734   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4735   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4736   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4737   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4738   unsigned size = fieldFromInstruction(Insn, 10, 2);
4739 
4740   unsigned align = 0;
4741   unsigned index = 0;
4742   unsigned inc = 1;
4743   switch (size) {
4744     default:
4745       return MCDisassembler::Fail;
4746     case 0:
4747       if (fieldFromInstruction(Insn, 4, 1))
4748         return MCDisassembler::Fail; // UNDEFINED
4749       index = fieldFromInstruction(Insn, 5, 3);
4750       break;
4751     case 1:
4752       if (fieldFromInstruction(Insn, 4, 1))
4753         return MCDisassembler::Fail; // UNDEFINED
4754       index = fieldFromInstruction(Insn, 6, 2);
4755       if (fieldFromInstruction(Insn, 5, 1))
4756         inc = 2;
4757       break;
4758     case 2:
4759       if (fieldFromInstruction(Insn, 4, 2))
4760         return MCDisassembler::Fail; // UNDEFINED
4761       index = fieldFromInstruction(Insn, 7, 1);
4762       if (fieldFromInstruction(Insn, 6, 1))
4763         inc = 2;
4764       break;
4765   }
4766 
4767   if (Rm != 0xF) { // Writeback
4768     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4769     return MCDisassembler::Fail;
4770   }
4771   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4772     return MCDisassembler::Fail;
4773   Inst.addOperand(MCOperand::createImm(align));
4774   if (Rm != 0xF) {
4775     if (Rm != 0xD) {
4776       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4777     return MCDisassembler::Fail;
4778     } else
4779       Inst.addOperand(MCOperand::createReg(0));
4780   }
4781 
4782   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4783     return MCDisassembler::Fail;
4784   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4785     return MCDisassembler::Fail;
4786   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
4787     return MCDisassembler::Fail;
4788   Inst.addOperand(MCOperand::createImm(index));
4789 
4790   return S;
4791 }
4792 
4793 static DecodeStatus DecodeVLD4LN(MCInst &Inst, unsigned Insn,
4794                          uint64_t Address, const void *Decoder) {
4795   DecodeStatus S = MCDisassembler::Success;
4796 
4797   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4798   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4799   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4800   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4801   unsigned size = fieldFromInstruction(Insn, 10, 2);
4802 
4803   unsigned align = 0;
4804   unsigned index = 0;
4805   unsigned inc = 1;
4806   switch (size) {
4807     default:
4808       return MCDisassembler::Fail;
4809     case 0:
4810       if (fieldFromInstruction(Insn, 4, 1))
4811         align = 4;
4812       index = fieldFromInstruction(Insn, 5, 3);
4813       break;
4814     case 1:
4815       if (fieldFromInstruction(Insn, 4, 1))
4816         align = 8;
4817       index = fieldFromInstruction(Insn, 6, 2);
4818       if (fieldFromInstruction(Insn, 5, 1))
4819         inc = 2;
4820       break;
4821     case 2:
4822       switch (fieldFromInstruction(Insn, 4, 2)) {
4823         case 0:
4824           align = 0; break;
4825         case 3:
4826           return MCDisassembler::Fail;
4827         default:
4828           align = 4 << fieldFromInstruction(Insn, 4, 2); break;
4829       }
4830 
4831       index = fieldFromInstruction(Insn, 7, 1);
4832       if (fieldFromInstruction(Insn, 6, 1))
4833         inc = 2;
4834       break;
4835   }
4836 
4837   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4838     return MCDisassembler::Fail;
4839   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4840     return MCDisassembler::Fail;
4841   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
4842     return MCDisassembler::Fail;
4843   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
4844     return MCDisassembler::Fail;
4845 
4846   if (Rm != 0xF) { // Writeback
4847     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4848       return MCDisassembler::Fail;
4849   }
4850   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4851     return MCDisassembler::Fail;
4852   Inst.addOperand(MCOperand::createImm(align));
4853   if (Rm != 0xF) {
4854     if (Rm != 0xD) {
4855       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4856         return MCDisassembler::Fail;
4857     } else
4858       Inst.addOperand(MCOperand::createReg(0));
4859   }
4860 
4861   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4862     return MCDisassembler::Fail;
4863   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4864     return MCDisassembler::Fail;
4865   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
4866     return MCDisassembler::Fail;
4867   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
4868     return MCDisassembler::Fail;
4869   Inst.addOperand(MCOperand::createImm(index));
4870 
4871   return S;
4872 }
4873 
4874 static DecodeStatus DecodeVST4LN(MCInst &Inst, unsigned Insn,
4875                          uint64_t Address, const void *Decoder) {
4876   DecodeStatus S = MCDisassembler::Success;
4877 
4878   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4879   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4880   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4881   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4882   unsigned size = fieldFromInstruction(Insn, 10, 2);
4883 
4884   unsigned align = 0;
4885   unsigned index = 0;
4886   unsigned inc = 1;
4887   switch (size) {
4888     default:
4889       return MCDisassembler::Fail;
4890     case 0:
4891       if (fieldFromInstruction(Insn, 4, 1))
4892         align = 4;
4893       index = fieldFromInstruction(Insn, 5, 3);
4894       break;
4895     case 1:
4896       if (fieldFromInstruction(Insn, 4, 1))
4897         align = 8;
4898       index = fieldFromInstruction(Insn, 6, 2);
4899       if (fieldFromInstruction(Insn, 5, 1))
4900         inc = 2;
4901       break;
4902     case 2:
4903       switch (fieldFromInstruction(Insn, 4, 2)) {
4904         case 0:
4905           align = 0; break;
4906         case 3:
4907           return MCDisassembler::Fail;
4908         default:
4909           align = 4 << fieldFromInstruction(Insn, 4, 2); break;
4910       }
4911 
4912       index = fieldFromInstruction(Insn, 7, 1);
4913       if (fieldFromInstruction(Insn, 6, 1))
4914         inc = 2;
4915       break;
4916   }
4917 
4918   if (Rm != 0xF) { // Writeback
4919     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4920     return MCDisassembler::Fail;
4921   }
4922   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4923     return MCDisassembler::Fail;
4924   Inst.addOperand(MCOperand::createImm(align));
4925   if (Rm != 0xF) {
4926     if (Rm != 0xD) {
4927       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4928     return MCDisassembler::Fail;
4929     } else
4930       Inst.addOperand(MCOperand::createReg(0));
4931   }
4932 
4933   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4934     return MCDisassembler::Fail;
4935   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4936     return MCDisassembler::Fail;
4937   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
4938     return MCDisassembler::Fail;
4939   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
4940     return MCDisassembler::Fail;
4941   Inst.addOperand(MCOperand::createImm(index));
4942 
4943   return S;
4944 }
4945 
4946 static DecodeStatus DecodeVMOVSRR(MCInst &Inst, unsigned Insn,
4947                                   uint64_t Address, const void *Decoder) {
4948   DecodeStatus S = MCDisassembler::Success;
4949   unsigned Rt  = fieldFromInstruction(Insn, 12, 4);
4950   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
4951   unsigned Rm  = fieldFromInstruction(Insn,  5, 1);
4952   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4953   Rm |= fieldFromInstruction(Insn, 0, 4) << 1;
4954 
4955   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
4956     S = MCDisassembler::SoftFail;
4957 
4958   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
4959     return MCDisassembler::Fail;
4960   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
4961     return MCDisassembler::Fail;
4962   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
4963     return MCDisassembler::Fail;
4964   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
4965     return MCDisassembler::Fail;
4966   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4967     return MCDisassembler::Fail;
4968 
4969   return S;
4970 }
4971 
4972 static DecodeStatus DecodeVMOVRRS(MCInst &Inst, unsigned Insn,
4973                                   uint64_t Address, const void *Decoder) {
4974   DecodeStatus S = MCDisassembler::Success;
4975   unsigned Rt  = fieldFromInstruction(Insn, 12, 4);
4976   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
4977   unsigned Rm  = fieldFromInstruction(Insn,  5, 1);
4978   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4979   Rm |= fieldFromInstruction(Insn, 0, 4) << 1;
4980 
4981   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
4982     S = MCDisassembler::SoftFail;
4983 
4984   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
4985     return MCDisassembler::Fail;
4986   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
4987     return MCDisassembler::Fail;
4988   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
4989     return MCDisassembler::Fail;
4990   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
4991     return MCDisassembler::Fail;
4992   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4993     return MCDisassembler::Fail;
4994 
4995   return S;
4996 }
4997 
4998 static DecodeStatus DecodeIT(MCInst &Inst, unsigned Insn,
4999                              uint64_t Address, const void *Decoder) {
5000   DecodeStatus S = MCDisassembler::Success;
5001   unsigned pred = fieldFromInstruction(Insn, 4, 4);
5002   unsigned mask = fieldFromInstruction(Insn, 0, 4);
5003 
5004   if (pred == 0xF) {
5005     pred = 0xE;
5006     S = MCDisassembler::SoftFail;
5007   }
5008 
5009   if (mask == 0x0)
5010     return MCDisassembler::Fail;
5011 
5012   Inst.addOperand(MCOperand::createImm(pred));
5013   Inst.addOperand(MCOperand::createImm(mask));
5014   return S;
5015 }
5016 
5017 static DecodeStatus
5018 DecodeT2LDRDPreInstruction(MCInst &Inst, unsigned Insn,
5019                            uint64_t Address, const void *Decoder) {
5020   DecodeStatus S = MCDisassembler::Success;
5021 
5022   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5023   unsigned Rt2 = fieldFromInstruction(Insn, 8, 4);
5024   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5025   unsigned addr = fieldFromInstruction(Insn, 0, 8);
5026   unsigned W = fieldFromInstruction(Insn, 21, 1);
5027   unsigned U = fieldFromInstruction(Insn, 23, 1);
5028   unsigned P = fieldFromInstruction(Insn, 24, 1);
5029   bool writeback = (W == 1) | (P == 0);
5030 
5031   addr |= (U << 8) | (Rn << 9);
5032 
5033   if (writeback && (Rn == Rt || Rn == Rt2))
5034     Check(S, MCDisassembler::SoftFail);
5035   if (Rt == Rt2)
5036     Check(S, MCDisassembler::SoftFail);
5037 
5038   // Rt
5039   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
5040     return MCDisassembler::Fail;
5041   // Rt2
5042   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
5043     return MCDisassembler::Fail;
5044   // Writeback operand
5045   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
5046     return MCDisassembler::Fail;
5047   // addr
5048   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
5049     return MCDisassembler::Fail;
5050 
5051   return S;
5052 }
5053 
5054 static DecodeStatus
5055 DecodeT2STRDPreInstruction(MCInst &Inst, unsigned Insn,
5056                            uint64_t Address, const void *Decoder) {
5057   DecodeStatus S = MCDisassembler::Success;
5058 
5059   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5060   unsigned Rt2 = fieldFromInstruction(Insn, 8, 4);
5061   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5062   unsigned addr = fieldFromInstruction(Insn, 0, 8);
5063   unsigned W = fieldFromInstruction(Insn, 21, 1);
5064   unsigned U = fieldFromInstruction(Insn, 23, 1);
5065   unsigned P = fieldFromInstruction(Insn, 24, 1);
5066   bool writeback = (W == 1) | (P == 0);
5067 
5068   addr |= (U << 8) | (Rn << 9);
5069 
5070   if (writeback && (Rn == Rt || Rn == Rt2))
5071     Check(S, MCDisassembler::SoftFail);
5072 
5073   // Writeback operand
5074   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
5075     return MCDisassembler::Fail;
5076   // Rt
5077   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
5078     return MCDisassembler::Fail;
5079   // Rt2
5080   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
5081     return MCDisassembler::Fail;
5082   // addr
5083   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
5084     return MCDisassembler::Fail;
5085 
5086   return S;
5087 }
5088 
5089 static DecodeStatus DecodeT2Adr(MCInst &Inst, uint32_t Insn,
5090                                 uint64_t Address, const void *Decoder) {
5091   unsigned sign1 = fieldFromInstruction(Insn, 21, 1);
5092   unsigned sign2 = fieldFromInstruction(Insn, 23, 1);
5093   if (sign1 != sign2) return MCDisassembler::Fail;
5094 
5095   unsigned Val = fieldFromInstruction(Insn, 0, 8);
5096   Val |= fieldFromInstruction(Insn, 12, 3) << 8;
5097   Val |= fieldFromInstruction(Insn, 26, 1) << 11;
5098   Val |= sign1 << 12;
5099   Inst.addOperand(MCOperand::createImm(SignExtend32<13>(Val)));
5100 
5101   return MCDisassembler::Success;
5102 }
5103 
5104 static DecodeStatus DecodeT2ShifterImmOperand(MCInst &Inst, uint32_t Val,
5105                                               uint64_t Address,
5106                                               const void *Decoder) {
5107   DecodeStatus S = MCDisassembler::Success;
5108 
5109   // Shift of "asr #32" is not allowed in Thumb2 mode.
5110   if (Val == 0x20) S = MCDisassembler::Fail;
5111   Inst.addOperand(MCOperand::createImm(Val));
5112   return S;
5113 }
5114 
5115 static DecodeStatus DecodeSwap(MCInst &Inst, unsigned Insn,
5116                                uint64_t Address, const void *Decoder) {
5117   unsigned Rt   = fieldFromInstruction(Insn, 12, 4);
5118   unsigned Rt2  = fieldFromInstruction(Insn, 0,  4);
5119   unsigned Rn   = fieldFromInstruction(Insn, 16, 4);
5120   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5121 
5122   if (pred == 0xF)
5123     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
5124 
5125   DecodeStatus S = MCDisassembler::Success;
5126 
5127   if (Rt == Rn || Rn == Rt2)
5128     S = MCDisassembler::SoftFail;
5129 
5130   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5131     return MCDisassembler::Fail;
5132   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5133     return MCDisassembler::Fail;
5134   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
5135     return MCDisassembler::Fail;
5136   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5137     return MCDisassembler::Fail;
5138 
5139   return S;
5140 }
5141 
5142 static DecodeStatus DecodeVCVTD(MCInst &Inst, unsigned Insn,
5143                                 uint64_t Address, const void *Decoder) {
5144   const FeatureBitset &featureBits =
5145       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5146   bool hasFullFP16 = featureBits[ARM::FeatureFullFP16];
5147 
5148   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5149   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5150   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5151   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5152   unsigned imm = fieldFromInstruction(Insn, 16, 6);
5153   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
5154   unsigned op = fieldFromInstruction(Insn, 5, 1);
5155 
5156   DecodeStatus S = MCDisassembler::Success;
5157 
5158   // If the top 3 bits of imm are clear, this is a VMOV (immediate)
5159   if (!(imm & 0x38)) {
5160     if (cmode == 0xF) {
5161       if (op == 1) return MCDisassembler::Fail;
5162       Inst.setOpcode(ARM::VMOVv2f32);
5163     }
5164     if (hasFullFP16) {
5165       if (cmode == 0xE) {
5166         if (op == 1) {
5167           Inst.setOpcode(ARM::VMOVv1i64);
5168         } else {
5169           Inst.setOpcode(ARM::VMOVv8i8);
5170         }
5171       }
5172       if (cmode == 0xD) {
5173         if (op == 1) {
5174           Inst.setOpcode(ARM::VMVNv2i32);
5175         } else {
5176           Inst.setOpcode(ARM::VMOVv2i32);
5177         }
5178       }
5179       if (cmode == 0xC) {
5180         if (op == 1) {
5181           Inst.setOpcode(ARM::VMVNv2i32);
5182         } else {
5183           Inst.setOpcode(ARM::VMOVv2i32);
5184         }
5185       }
5186     }
5187     return DecodeNEONModImmInstruction(Inst, Insn, Address, Decoder);
5188   }
5189 
5190   if (!(imm & 0x20)) return MCDisassembler::Fail;
5191 
5192   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
5193     return MCDisassembler::Fail;
5194   if (!Check(S, DecodeDPRRegisterClass(Inst, Vm, Address, Decoder)))
5195     return MCDisassembler::Fail;
5196   Inst.addOperand(MCOperand::createImm(64 - imm));
5197 
5198   return S;
5199 }
5200 
5201 static DecodeStatus DecodeVCVTQ(MCInst &Inst, unsigned Insn,
5202                                 uint64_t Address, const void *Decoder) {
5203   const FeatureBitset &featureBits =
5204       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5205   bool hasFullFP16 = featureBits[ARM::FeatureFullFP16];
5206 
5207   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5208   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5209   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5210   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5211   unsigned imm = fieldFromInstruction(Insn, 16, 6);
5212   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
5213   unsigned op = fieldFromInstruction(Insn, 5, 1);
5214 
5215   DecodeStatus S = MCDisassembler::Success;
5216 
5217   // If the top 3 bits of imm are clear, this is a VMOV (immediate)
5218   if (!(imm & 0x38)) {
5219     if (cmode == 0xF) {
5220       if (op == 1) return MCDisassembler::Fail;
5221       Inst.setOpcode(ARM::VMOVv4f32);
5222     }
5223     if (hasFullFP16) {
5224       if (cmode == 0xE) {
5225         if (op == 1) {
5226           Inst.setOpcode(ARM::VMOVv2i64);
5227         } else {
5228           Inst.setOpcode(ARM::VMOVv16i8);
5229         }
5230       }
5231       if (cmode == 0xD) {
5232         if (op == 1) {
5233           Inst.setOpcode(ARM::VMVNv4i32);
5234         } else {
5235           Inst.setOpcode(ARM::VMOVv4i32);
5236         }
5237       }
5238       if (cmode == 0xC) {
5239         if (op == 1) {
5240           Inst.setOpcode(ARM::VMVNv4i32);
5241         } else {
5242           Inst.setOpcode(ARM::VMOVv4i32);
5243         }
5244       }
5245     }
5246     return DecodeNEONModImmInstruction(Inst, Insn, Address, Decoder);
5247   }
5248 
5249   if (!(imm & 0x20)) return MCDisassembler::Fail;
5250 
5251   if (!Check(S, DecodeQPRRegisterClass(Inst, Vd, Address, Decoder)))
5252     return MCDisassembler::Fail;
5253   if (!Check(S, DecodeQPRRegisterClass(Inst, Vm, Address, Decoder)))
5254     return MCDisassembler::Fail;
5255   Inst.addOperand(MCOperand::createImm(64 - imm));
5256 
5257   return S;
5258 }
5259 
5260 static DecodeStatus DecodeNEONComplexLane64Instruction(MCInst &Inst,
5261                                                        unsigned Insn,
5262                                                        uint64_t Address,
5263                                                        const void *Decoder) {
5264   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5265   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5266   unsigned Vn = (fieldFromInstruction(Insn, 16, 4) << 0);
5267   Vn |= (fieldFromInstruction(Insn, 7, 1) << 4);
5268   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5269   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5270   unsigned q = (fieldFromInstruction(Insn, 6, 1) << 0);
5271   unsigned rotate = (fieldFromInstruction(Insn, 20, 2) << 0);
5272 
5273   DecodeStatus S = MCDisassembler::Success;
5274 
5275   auto DestRegDecoder = q ? DecodeQPRRegisterClass : DecodeDPRRegisterClass;
5276 
5277   if (!Check(S, DestRegDecoder(Inst, Vd, Address, Decoder)))
5278     return MCDisassembler::Fail;
5279   if (!Check(S, DestRegDecoder(Inst, Vd, Address, Decoder)))
5280     return MCDisassembler::Fail;
5281   if (!Check(S, DestRegDecoder(Inst, Vn, Address, Decoder)))
5282     return MCDisassembler::Fail;
5283   if (!Check(S, DecodeDPRRegisterClass(Inst, Vm, Address, Decoder)))
5284     return MCDisassembler::Fail;
5285   // The lane index does not have any bits in the encoding, because it can only
5286   // be 0.
5287   Inst.addOperand(MCOperand::createImm(0));
5288   Inst.addOperand(MCOperand::createImm(rotate));
5289 
5290   return S;
5291 }
5292 
5293 static DecodeStatus DecodeLDR(MCInst &Inst, unsigned Val,
5294                                 uint64_t Address, const void *Decoder) {
5295   DecodeStatus S = MCDisassembler::Success;
5296 
5297   unsigned Rn = fieldFromInstruction(Val, 16, 4);
5298   unsigned Rt = fieldFromInstruction(Val, 12, 4);
5299   unsigned Rm = fieldFromInstruction(Val, 0, 4);
5300   Rm |= (fieldFromInstruction(Val, 23, 1) << 4);
5301   unsigned Cond = fieldFromInstruction(Val, 28, 4);
5302 
5303   if (fieldFromInstruction(Val, 8, 4) != 0 || Rn == Rt)
5304     S = MCDisassembler::SoftFail;
5305 
5306   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5307     return MCDisassembler::Fail;
5308   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
5309     return MCDisassembler::Fail;
5310   if (!Check(S, DecodeAddrMode7Operand(Inst, Rn, Address, Decoder)))
5311     return MCDisassembler::Fail;
5312   if (!Check(S, DecodePostIdxReg(Inst, Rm, Address, Decoder)))
5313     return MCDisassembler::Fail;
5314   if (!Check(S, DecodePredicateOperand(Inst, Cond, Address, Decoder)))
5315     return MCDisassembler::Fail;
5316 
5317   return S;
5318 }
5319 
5320 static DecodeStatus DecoderForMRRC2AndMCRR2(MCInst &Inst, unsigned Val,
5321                                             uint64_t Address, const void *Decoder) {
5322   DecodeStatus S = MCDisassembler::Success;
5323 
5324   unsigned CRm = fieldFromInstruction(Val, 0, 4);
5325   unsigned opc1 = fieldFromInstruction(Val, 4, 4);
5326   unsigned cop = fieldFromInstruction(Val, 8, 4);
5327   unsigned Rt = fieldFromInstruction(Val, 12, 4);
5328   unsigned Rt2 = fieldFromInstruction(Val, 16, 4);
5329 
5330   if ((cop & ~0x1) == 0xa)
5331     return MCDisassembler::Fail;
5332 
5333   if (Rt == Rt2)
5334     S = MCDisassembler::SoftFail;
5335 
5336   // We have to check if the instruction is MRRC2
5337   // or MCRR2 when constructing the operands for
5338   // Inst. Reason is because MRRC2 stores to two
5339   // registers so it's tablegen desc has has two
5340   // outputs whereas MCRR doesn't store to any
5341   // registers so all of it's operands are listed
5342   // as inputs, therefore the operand order for
5343   // MRRC2 needs to be [Rt, Rt2, cop, opc1, CRm]
5344   // and MCRR2 operand order is [cop, opc1, Rt, Rt2, CRm]
5345 
5346   if (Inst.getOpcode() == ARM::MRRC2) {
5347     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5348       return MCDisassembler::Fail;
5349     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5350       return MCDisassembler::Fail;
5351   }
5352   Inst.addOperand(MCOperand::createImm(cop));
5353   Inst.addOperand(MCOperand::createImm(opc1));
5354   if (Inst.getOpcode() == ARM::MCRR2) {
5355     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5356       return MCDisassembler::Fail;
5357     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5358       return MCDisassembler::Fail;
5359   }
5360   Inst.addOperand(MCOperand::createImm(CRm));
5361 
5362   return S;
5363 }
5364 
5365 static DecodeStatus DecodeForVMRSandVMSR(MCInst &Inst, unsigned Val,
5366                                          uint64_t Address,
5367                                          const void *Decoder) {
5368   const FeatureBitset &featureBits =
5369       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5370   DecodeStatus S = MCDisassembler::Success;
5371 
5372   unsigned Rt = fieldFromInstruction(Val, 12, 4);
5373 
5374   if (featureBits[ARM::ModeThumb] && !featureBits[ARM::HasV8Ops]) {
5375     if (Rt == 13 || Rt == 15)
5376       S = MCDisassembler::SoftFail;
5377     Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder));
5378   } else
5379     Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder));
5380 
5381   if (featureBits[ARM::ModeThumb]) {
5382     Inst.addOperand(MCOperand::createImm(ARMCC::AL));
5383     Inst.addOperand(MCOperand::createReg(0));
5384   } else {
5385     unsigned pred = fieldFromInstruction(Val, 28, 4);
5386     if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5387       return MCDisassembler::Fail;
5388   }
5389 
5390   return S;
5391 }
5392