1 //===- ARMDisassembler.cpp - Disassembler for ARM/Thumb ISA ---------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "ARMBaseInstrInfo.h"
10 #include "MCTargetDesc/ARMAddressingModes.h"
11 #include "MCTargetDesc/ARMBaseInfo.h"
12 #include "MCTargetDesc/ARMMCTargetDesc.h"
13 #include "TargetInfo/ARMTargetInfo.h"
14 #include "Utils/ARMBaseInfo.h"
15 #include "llvm/MC/MCContext.h"
16 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
17 #include "llvm/MC/MCFixedLenDisassembler.h"
18 #include "llvm/MC/MCInst.h"
19 #include "llvm/MC/MCInstrDesc.h"
20 #include "llvm/MC/MCSubtargetInfo.h"
21 #include "llvm/MC/SubtargetFeature.h"
22 #include "llvm/Support/Compiler.h"
23 #include "llvm/Support/ErrorHandling.h"
24 #include "llvm/Support/MathExtras.h"
25 #include "llvm/Support/TargetRegistry.h"
26 #include "llvm/Support/raw_ostream.h"
27 #include <algorithm>
28 #include <cassert>
29 #include <cstdint>
30 #include <vector>
31 
32 using namespace llvm;
33 
34 #define DEBUG_TYPE "arm-disassembler"
35 
36 using DecodeStatus = MCDisassembler::DecodeStatus;
37 
38 namespace {
39 
40   // Handles the condition code status of instructions in IT blocks
41   class ITStatus
42   {
43     public:
44       // Returns the condition code for instruction in IT block
45       unsigned getITCC() {
46         unsigned CC = ARMCC::AL;
47         if (instrInITBlock())
48           CC = ITStates.back();
49         return CC;
50       }
51 
52       // Advances the IT block state to the next T or E
53       void advanceITState() {
54         ITStates.pop_back();
55       }
56 
57       // Returns true if the current instruction is in an IT block
58       bool instrInITBlock() {
59         return !ITStates.empty();
60       }
61 
62       // Returns true if current instruction is the last instruction in an IT block
63       bool instrLastInITBlock() {
64         return ITStates.size() == 1;
65       }
66 
67       // Called when decoding an IT instruction. Sets the IT state for
68       // the following instructions that for the IT block. Firstcond
69       // corresponds to the field in the IT instruction encoding; Mask
70       // is in the MCOperand format in which 1 means 'else' and 0 'then'.
71       void setITState(char Firstcond, char Mask) {
72         // (3 - the number of trailing zeros) is the number of then / else.
73         unsigned NumTZ = countTrailingZeros<uint8_t>(Mask);
74         unsigned char CCBits = static_cast<unsigned char>(Firstcond & 0xf);
75         assert(NumTZ <= 3 && "Invalid IT mask!");
76         // push condition codes onto the stack the correct order for the pops
77         for (unsigned Pos = NumTZ+1; Pos <= 3; ++Pos) {
78           unsigned Else = (Mask >> Pos) & 1;
79           ITStates.push_back(CCBits ^ Else);
80         }
81         ITStates.push_back(CCBits);
82       }
83 
84     private:
85       std::vector<unsigned char> ITStates;
86   };
87 
88   class VPTStatus
89   {
90     public:
91       unsigned getVPTPred() {
92         unsigned Pred = ARMVCC::None;
93         if (instrInVPTBlock())
94           Pred = VPTStates.back();
95         return Pred;
96       }
97 
98       void advanceVPTState() {
99         VPTStates.pop_back();
100       }
101 
102       bool instrInVPTBlock() {
103         return !VPTStates.empty();
104       }
105 
106       bool instrLastInVPTBlock() {
107         return VPTStates.size() == 1;
108       }
109 
110       void setVPTState(char Mask) {
111         // (3 - the number of trailing zeros) is the number of then / else.
112         unsigned NumTZ = countTrailingZeros<uint8_t>(Mask);
113         assert(NumTZ <= 3 && "Invalid VPT mask!");
114         // push predicates onto the stack the correct order for the pops
115         for (unsigned Pos = NumTZ+1; Pos <= 3; ++Pos) {
116           bool T = ((Mask >> Pos) & 1) == 0;
117           if (T)
118             VPTStates.push_back(ARMVCC::Then);
119           else
120             VPTStates.push_back(ARMVCC::Else);
121         }
122         VPTStates.push_back(ARMVCC::Then);
123       }
124 
125     private:
126       SmallVector<unsigned char, 4> VPTStates;
127   };
128 
129 /// ARM disassembler for all ARM platforms.
130 class ARMDisassembler : public MCDisassembler {
131 public:
132   ARMDisassembler(const MCSubtargetInfo &STI, MCContext &Ctx) :
133     MCDisassembler(STI, Ctx) {
134   }
135 
136   ~ARMDisassembler() override = default;
137 
138   DecodeStatus getInstruction(MCInst &Instr, uint64_t &Size,
139                               ArrayRef<uint8_t> Bytes, uint64_t Address,
140                               raw_ostream &CStream) const override;
141 
142 private:
143   DecodeStatus getARMInstruction(MCInst &Instr, uint64_t &Size,
144                                  ArrayRef<uint8_t> Bytes, uint64_t Address,
145                                  raw_ostream &CStream) const;
146 
147   DecodeStatus getThumbInstruction(MCInst &Instr, uint64_t &Size,
148                                    ArrayRef<uint8_t> Bytes, uint64_t Address,
149                                    raw_ostream &CStream) const;
150 
151   mutable ITStatus ITBlock;
152   mutable VPTStatus VPTBlock;
153 
154   DecodeStatus AddThumbPredicate(MCInst&) const;
155   void UpdateThumbVFPPredicate(DecodeStatus &, MCInst&) const;
156 };
157 
158 } // end anonymous namespace
159 
160 static bool Check(DecodeStatus &Out, DecodeStatus In) {
161   switch (In) {
162     case MCDisassembler::Success:
163       // Out stays the same.
164       return true;
165     case MCDisassembler::SoftFail:
166       Out = In;
167       return true;
168     case MCDisassembler::Fail:
169       Out = In;
170       return false;
171   }
172   llvm_unreachable("Invalid DecodeStatus!");
173 }
174 
175 // Forward declare these because the autogenerated code will reference them.
176 // Definitions are further down.
177 static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, unsigned RegNo,
178                                    uint64_t Address, const void *Decoder);
179 static DecodeStatus DecodeCLRMGPRRegisterClass(MCInst &Inst, unsigned RegNo,
180                                    uint64_t Address, const void *Decoder);
181 static DecodeStatus DecodetGPROddRegisterClass(MCInst &Inst, unsigned RegNo,
182                                    uint64_t Address, const void *Decoder);
183 static DecodeStatus DecodetGPREvenRegisterClass(MCInst &Inst, unsigned RegNo,
184                                    uint64_t Address, const void *Decoder);
185 static DecodeStatus
186 DecodeGPRwithAPSR_NZCVnospRegisterClass(MCInst &Inst, unsigned RegNo,
187                                         uint64_t Address, const void *Decoder);
188 static DecodeStatus DecodeGPRnopcRegisterClass(MCInst &Inst,
189                                                unsigned RegNo, uint64_t Address,
190                                                const void *Decoder);
191 static DecodeStatus DecodeGPRwithAPSRRegisterClass(MCInst &Inst,
192                                                unsigned RegNo, uint64_t Address,
193                                                const void *Decoder);
194 static DecodeStatus DecodeGPRwithZRRegisterClass(MCInst &Inst,
195                                                unsigned RegNo, uint64_t Address,
196                                                const void *Decoder);
197 static DecodeStatus DecodeGPRwithZRnospRegisterClass(
198     MCInst &Inst, unsigned RegNo, uint64_t Address, const void *Decoder);
199 static DecodeStatus DecodetGPRRegisterClass(MCInst &Inst, unsigned RegNo,
200                                    uint64_t Address, const void *Decoder);
201 static DecodeStatus DecodetcGPRRegisterClass(MCInst &Inst, unsigned RegNo,
202                                    uint64_t Address, const void *Decoder);
203 static DecodeStatus DecoderGPRRegisterClass(MCInst &Inst, unsigned RegNo,
204                                    uint64_t Address, const void *Decoder);
205 static DecodeStatus DecodeGPRPairRegisterClass(MCInst &Inst, unsigned RegNo,
206                                    uint64_t Address, const void *Decoder);
207 static DecodeStatus DecodeGPRPairnospRegisterClass(MCInst &Inst, unsigned RegNo,
208                                    uint64_t Address, const void *Decoder);
209 static DecodeStatus DecodeGPRspRegisterClass(MCInst &Inst, unsigned RegNo,
210                                              uint64_t Address,
211                                              const void *Decoder);
212 static DecodeStatus DecodeHPRRegisterClass(MCInst &Inst, unsigned RegNo,
213                                    uint64_t Address, const void *Decoder);
214 static DecodeStatus DecodeSPRRegisterClass(MCInst &Inst, unsigned RegNo,
215                                    uint64_t Address, const void *Decoder);
216 static DecodeStatus DecodeDPRRegisterClass(MCInst &Inst, unsigned RegNo,
217                                    uint64_t Address, const void *Decoder);
218 static DecodeStatus DecodeDPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
219                                    uint64_t Address, const void *Decoder);
220 static DecodeStatus DecodeSPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
221                                    uint64_t Address, const void *Decoder);
222 static DecodeStatus DecodeDPR_VFP2RegisterClass(MCInst &Inst,
223                                                 unsigned RegNo,
224                                                 uint64_t Address,
225                                                 const void *Decoder);
226 static DecodeStatus DecodeQPRRegisterClass(MCInst &Inst, unsigned RegNo,
227                                    uint64_t Address, const void *Decoder);
228 static DecodeStatus DecodeMQPRRegisterClass(MCInst &Inst, unsigned RegNo,
229                                    uint64_t Address, const void *Decoder);
230 static DecodeStatus DecodeQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
231                                    uint64_t Address, const void *Decoder);
232 static DecodeStatus DecodeQQQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
233                                    uint64_t Address, const void *Decoder);
234 static DecodeStatus DecodeDPairRegisterClass(MCInst &Inst, unsigned RegNo,
235                                    uint64_t Address, const void *Decoder);
236 static DecodeStatus DecodeDPairSpacedRegisterClass(MCInst &Inst,
237                                unsigned RegNo, uint64_t Address,
238                                const void *Decoder);
239 
240 static DecodeStatus DecodePredicateOperand(MCInst &Inst, unsigned Val,
241                                uint64_t Address, const void *Decoder);
242 static DecodeStatus DecodeCCOutOperand(MCInst &Inst, unsigned Val,
243                                uint64_t Address, const void *Decoder);
244 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Val,
245                                uint64_t Address, const void *Decoder);
246 static DecodeStatus DecodeSPRRegListOperand(MCInst &Inst, unsigned Val,
247                                uint64_t Address, const void *Decoder);
248 static DecodeStatus DecodeDPRRegListOperand(MCInst &Inst, unsigned Val,
249                                uint64_t Address, const void *Decoder);
250 
251 static DecodeStatus DecodeBitfieldMaskOperand(MCInst &Inst, unsigned Insn,
252                                uint64_t Address, const void *Decoder);
253 static DecodeStatus DecodeCopMemInstruction(MCInst &Inst, unsigned Insn,
254                                uint64_t Address, const void *Decoder);
255 static DecodeStatus DecodeAddrMode2IdxInstruction(MCInst &Inst,
256                                                   unsigned Insn,
257                                                   uint64_t Address,
258                                                   const void *Decoder);
259 static DecodeStatus DecodeSORegMemOperand(MCInst &Inst, unsigned Insn,
260                                uint64_t Address, const void *Decoder);
261 static DecodeStatus DecodeAddrMode3Instruction(MCInst &Inst,unsigned Insn,
262                                uint64_t Address, const void *Decoder);
263 static DecodeStatus DecodeSORegImmOperand(MCInst &Inst, unsigned Insn,
264                                uint64_t Address, const void *Decoder);
265 static DecodeStatus DecodeSORegRegOperand(MCInst &Inst, unsigned Insn,
266                                uint64_t Address, const void *Decoder);
267 
268 static DecodeStatus DecodeMemMultipleWritebackInstruction(MCInst & Inst,
269                                                   unsigned Insn,
270                                                   uint64_t Adddress,
271                                                   const void *Decoder);
272 static DecodeStatus DecodeT2MOVTWInstruction(MCInst &Inst, unsigned Insn,
273                                uint64_t Address, const void *Decoder);
274 static DecodeStatus DecodeArmMOVTWInstruction(MCInst &Inst, unsigned Insn,
275                                uint64_t Address, const void *Decoder);
276 static DecodeStatus DecodeSMLAInstruction(MCInst &Inst, unsigned Insn,
277                                uint64_t Address, const void *Decoder);
278 static DecodeStatus DecodeHINTInstruction(MCInst &Inst, unsigned Insn,
279                                uint64_t Address, const void *Decoder);
280 static DecodeStatus DecodeCPSInstruction(MCInst &Inst, unsigned Insn,
281                                uint64_t Address, const void *Decoder);
282 static DecodeStatus DecodeTSTInstruction(MCInst &Inst, unsigned Insn,
283                                uint64_t Address, const void *Decoder);
284 static DecodeStatus DecodeSETPANInstruction(MCInst &Inst, unsigned Insn,
285                                uint64_t Address, const void *Decoder);
286 static DecodeStatus DecodeT2CPSInstruction(MCInst &Inst, unsigned Insn,
287                                uint64_t Address, const void *Decoder);
288 static DecodeStatus DecodeAddrModeImm12Operand(MCInst &Inst, unsigned Val,
289                                uint64_t Address, const void *Decoder);
290 static DecodeStatus DecodeAddrMode5Operand(MCInst &Inst, unsigned Val,
291                                uint64_t Address, const void *Decoder);
292 static DecodeStatus DecodeAddrMode5FP16Operand(MCInst &Inst, unsigned Val,
293                                uint64_t Address, const void *Decoder);
294 static DecodeStatus DecodeAddrMode7Operand(MCInst &Inst, unsigned Val,
295                                uint64_t Address, const void *Decoder);
296 static DecodeStatus DecodeT2BInstruction(MCInst &Inst, unsigned Insn,
297                                uint64_t Address, const void *Decoder);
298 static DecodeStatus DecodeBranchImmInstruction(MCInst &Inst,unsigned Insn,
299                                uint64_t Address, const void *Decoder);
300 static DecodeStatus DecodeAddrMode6Operand(MCInst &Inst, unsigned Val,
301                                uint64_t Address, const void *Decoder);
302 static DecodeStatus DecodeVLDST1Instruction(MCInst &Inst, unsigned Val,
303                                uint64_t Address, const void *Decoder);
304 static DecodeStatus DecodeVLDST2Instruction(MCInst &Inst, unsigned Val,
305                                uint64_t Address, const void *Decoder);
306 static DecodeStatus DecodeVLDST3Instruction(MCInst &Inst, unsigned Val,
307                                uint64_t Address, const void *Decoder);
308 static DecodeStatus DecodeVLDST4Instruction(MCInst &Inst, unsigned Val,
309                                uint64_t Address, const void *Decoder);
310 static DecodeStatus DecodeVLDInstruction(MCInst &Inst, unsigned Val,
311                                uint64_t Address, const void *Decoder);
312 static DecodeStatus DecodeVSTInstruction(MCInst &Inst, unsigned Val,
313                                uint64_t Address, const void *Decoder);
314 static DecodeStatus DecodeVLD1DupInstruction(MCInst &Inst, unsigned Val,
315                                uint64_t Address, const void *Decoder);
316 static DecodeStatus DecodeVLD2DupInstruction(MCInst &Inst, unsigned Val,
317                                uint64_t Address, const void *Decoder);
318 static DecodeStatus DecodeVLD3DupInstruction(MCInst &Inst, unsigned Val,
319                                uint64_t Address, const void *Decoder);
320 static DecodeStatus DecodeVLD4DupInstruction(MCInst &Inst, unsigned Val,
321                                uint64_t Address, const void *Decoder);
322 static DecodeStatus DecodeVMOVModImmInstruction(MCInst &Inst,unsigned Val,
323                                uint64_t Address, const void *Decoder);
324 static DecodeStatus DecodeMVEModImmInstruction(MCInst &Inst,unsigned Val,
325                                uint64_t Address, const void *Decoder);
326 static DecodeStatus DecodeMVEVADCInstruction(MCInst &Inst, unsigned Insn,
327                                uint64_t Address, const void *Decoder);
328 static DecodeStatus DecodeVSHLMaxInstruction(MCInst &Inst, unsigned Val,
329                                uint64_t Address, const void *Decoder);
330 static DecodeStatus DecodeShiftRight8Imm(MCInst &Inst, unsigned Val,
331                                uint64_t Address, const void *Decoder);
332 static DecodeStatus DecodeShiftRight16Imm(MCInst &Inst, unsigned Val,
333                                uint64_t Address, const void *Decoder);
334 static DecodeStatus DecodeShiftRight32Imm(MCInst &Inst, unsigned Val,
335                                uint64_t Address, const void *Decoder);
336 static DecodeStatus DecodeShiftRight64Imm(MCInst &Inst, unsigned Val,
337                                uint64_t Address, const void *Decoder);
338 static DecodeStatus DecodeTBLInstruction(MCInst &Inst, unsigned Insn,
339                                uint64_t Address, const void *Decoder);
340 static DecodeStatus DecodePostIdxReg(MCInst &Inst, unsigned Insn,
341                                uint64_t Address, const void *Decoder);
342 static DecodeStatus DecodeMveAddrModeRQ(MCInst &Inst, unsigned Insn,
343                                uint64_t Address, const void *Decoder);
344 template<int shift>
345 static DecodeStatus DecodeMveAddrModeQ(MCInst &Inst, unsigned Insn,
346                                uint64_t Address, const void *Decoder);
347 static DecodeStatus DecodeCoprocessor(MCInst &Inst, unsigned Insn,
348                                uint64_t Address, const void *Decoder);
349 static DecodeStatus DecodeMemBarrierOption(MCInst &Inst, unsigned Insn,
350                                uint64_t Address, const void *Decoder);
351 static DecodeStatus DecodeInstSyncBarrierOption(MCInst &Inst, unsigned Insn,
352                                uint64_t Address, const void *Decoder);
353 static DecodeStatus DecodeMSRMask(MCInst &Inst, unsigned Insn,
354                                uint64_t Address, const void *Decoder);
355 static DecodeStatus DecodeBankedReg(MCInst &Inst, unsigned Insn,
356                                uint64_t Address, const void *Decoder);
357 static DecodeStatus DecodeDoubleRegLoad(MCInst &Inst, unsigned Insn,
358                                uint64_t Address, const void *Decoder);
359 static DecodeStatus DecodeDoubleRegStore(MCInst &Inst, unsigned Insn,
360                                uint64_t Address, const void *Decoder);
361 static DecodeStatus DecodeLDRPreImm(MCInst &Inst, unsigned Insn,
362                                uint64_t Address, const void *Decoder);
363 static DecodeStatus DecodeLDRPreReg(MCInst &Inst, unsigned Insn,
364                                uint64_t Address, const void *Decoder);
365 static DecodeStatus DecodeSTRPreImm(MCInst &Inst, unsigned Insn,
366                                uint64_t Address, const void *Decoder);
367 static DecodeStatus DecodeSTRPreReg(MCInst &Inst, unsigned Insn,
368                                uint64_t Address, const void *Decoder);
369 static DecodeStatus DecodeVLD1LN(MCInst &Inst, unsigned Insn,
370                                uint64_t Address, const void *Decoder);
371 static DecodeStatus DecodeVLD2LN(MCInst &Inst, unsigned Insn,
372                                uint64_t Address, const void *Decoder);
373 static DecodeStatus DecodeVLD3LN(MCInst &Inst, unsigned Insn,
374                                uint64_t Address, const void *Decoder);
375 static DecodeStatus DecodeVLD4LN(MCInst &Inst, unsigned Insn,
376                                uint64_t Address, const void *Decoder);
377 static DecodeStatus DecodeVST1LN(MCInst &Inst, unsigned Insn,
378                                uint64_t Address, const void *Decoder);
379 static DecodeStatus DecodeVST2LN(MCInst &Inst, unsigned Insn,
380                                uint64_t Address, const void *Decoder);
381 static DecodeStatus DecodeVST3LN(MCInst &Inst, unsigned Insn,
382                                uint64_t Address, const void *Decoder);
383 static DecodeStatus DecodeVST4LN(MCInst &Inst, unsigned Insn,
384                                uint64_t Address, const void *Decoder);
385 static DecodeStatus DecodeVMOVSRR(MCInst &Inst, unsigned Insn,
386                                uint64_t Address, const void *Decoder);
387 static DecodeStatus DecodeVMOVRRS(MCInst &Inst, unsigned Insn,
388                                uint64_t Address, const void *Decoder);
389 static DecodeStatus DecodeSwap(MCInst &Inst, unsigned Insn,
390                                uint64_t Address, const void *Decoder);
391 static DecodeStatus DecodeVCVTD(MCInst &Inst, unsigned Insn,
392                                 uint64_t Address, const void *Decoder);
393 static DecodeStatus DecodeVCVTQ(MCInst &Inst, unsigned Insn,
394                                 uint64_t Address, const void *Decoder);
395 static DecodeStatus DecodeVCVTImmOperand(MCInst &Inst, unsigned Insn,
396                                          uint64_t Address, const void *Decoder);
397 static DecodeStatus DecodeNEONComplexLane64Instruction(MCInst &Inst,
398                                                        unsigned Val,
399                                                        uint64_t Address,
400                                                        const void *Decoder);
401 
402 static DecodeStatus DecodeThumbAddSpecialReg(MCInst &Inst, uint16_t Insn,
403                                uint64_t Address, const void *Decoder);
404 static DecodeStatus DecodeThumbBROperand(MCInst &Inst, unsigned Val,
405                                uint64_t Address, const void *Decoder);
406 static DecodeStatus DecodeT2BROperand(MCInst &Inst, unsigned Val,
407                                uint64_t Address, const void *Decoder);
408 static DecodeStatus DecodeThumbCmpBROperand(MCInst &Inst, unsigned Val,
409                                uint64_t Address, const void *Decoder);
410 static DecodeStatus DecodeThumbAddrModeRR(MCInst &Inst, unsigned Val,
411                                uint64_t Address, const void *Decoder);
412 static DecodeStatus DecodeThumbAddrModeIS(MCInst &Inst, unsigned Val,
413                                uint64_t Address, const void *Decoder);
414 static DecodeStatus DecodeThumbAddrModePC(MCInst &Inst, unsigned Val,
415                                uint64_t Address, const void *Decoder);
416 static DecodeStatus DecodeThumbAddrModeSP(MCInst &Inst, unsigned Val,
417                                uint64_t Address, const void *Decoder);
418 static DecodeStatus DecodeT2AddrModeSOReg(MCInst &Inst, unsigned Val,
419                                uint64_t Address, const void *Decoder);
420 static DecodeStatus DecodeT2LoadShift(MCInst &Inst, unsigned Val,
421                                uint64_t Address, const void *Decoder);
422 static DecodeStatus DecodeT2LoadImm8(MCInst &Inst, unsigned Insn,
423                                uint64_t Address, const void* Decoder);
424 static DecodeStatus DecodeT2LoadImm12(MCInst &Inst, unsigned Insn,
425                                uint64_t Address, const void* Decoder);
426 static DecodeStatus DecodeT2LoadT(MCInst &Inst, unsigned Insn,
427                                uint64_t Address, const void* Decoder);
428 static DecodeStatus DecodeT2LoadLabel(MCInst &Inst, unsigned Insn,
429                                uint64_t Address, const void* Decoder);
430 static DecodeStatus DecodeT2Imm8S4(MCInst &Inst, unsigned Val,
431                                uint64_t Address, const void *Decoder);
432 static DecodeStatus DecodeT2Imm7S4(MCInst &Inst, unsigned Val,
433                                uint64_t Address, const void *Decoder);
434 static DecodeStatus DecodeT2AddrModeImm8s4(MCInst &Inst, unsigned Val,
435                                uint64_t Address, const void *Decoder);
436 static DecodeStatus DecodeT2AddrModeImm7s4(MCInst &Inst, unsigned Val,
437                                            uint64_t Address,
438                                            const void *Decoder);
439 static DecodeStatus DecodeT2AddrModeImm0_1020s4(MCInst &Inst,unsigned Val,
440                                uint64_t Address, const void *Decoder);
441 static DecodeStatus DecodeT2Imm8(MCInst &Inst, unsigned Val,
442                                uint64_t Address, const void *Decoder);
443 template<int shift>
444 static DecodeStatus DecodeT2Imm7(MCInst &Inst, unsigned Val,
445                                uint64_t Address, const void *Decoder);
446 static DecodeStatus DecodeT2AddrModeImm8(MCInst &Inst, unsigned Val,
447                                uint64_t Address, const void *Decoder);
448 template<int shift>
449 static DecodeStatus DecodeTAddrModeImm7(MCInst &Inst, unsigned Val,
450                                uint64_t Address, const void *Decoder);
451 template<int shift, int WriteBack>
452 static DecodeStatus DecodeT2AddrModeImm7(MCInst &Inst, unsigned Val,
453                                uint64_t Address, const void *Decoder);
454 static DecodeStatus DecodeThumbAddSPImm(MCInst &Inst, uint16_t Val,
455                                uint64_t Address, const void *Decoder);
456 static DecodeStatus DecodeThumbAddSPReg(MCInst &Inst, uint16_t Insn,
457                                 uint64_t Address, const void *Decoder);
458 static DecodeStatus DecodeThumbCPS(MCInst &Inst, uint16_t Insn,
459                                 uint64_t Address, const void *Decoder);
460 static DecodeStatus DecodeQADDInstruction(MCInst &Inst, unsigned Insn,
461                                 uint64_t Address, const void *Decoder);
462 static DecodeStatus DecodeThumbBLXOffset(MCInst &Inst, unsigned Insn,
463                                 uint64_t Address, const void *Decoder);
464 static DecodeStatus DecodeT2AddrModeImm12(MCInst &Inst, unsigned Val,
465                                 uint64_t Address, const void *Decoder);
466 static DecodeStatus DecodeThumbTableBranch(MCInst &Inst, unsigned Val,
467                                 uint64_t Address, const void *Decoder);
468 static DecodeStatus DecodeThumb2BCCInstruction(MCInst &Inst, unsigned Val,
469                                 uint64_t Address, const void *Decoder);
470 static DecodeStatus DecodeT2SOImm(MCInst &Inst, unsigned Val,
471                                 uint64_t Address, const void *Decoder);
472 static DecodeStatus DecodeThumbBCCTargetOperand(MCInst &Inst,unsigned Val,
473                                 uint64_t Address, const void *Decoder);
474 static DecodeStatus DecodeThumbBLTargetOperand(MCInst &Inst, unsigned Val,
475                                 uint64_t Address, const void *Decoder);
476 static DecodeStatus DecodeIT(MCInst &Inst, unsigned Val,
477                                 uint64_t Address, const void *Decoder);
478 static DecodeStatus DecodeT2LDRDPreInstruction(MCInst &Inst,unsigned Insn,
479                                uint64_t Address, const void *Decoder);
480 static DecodeStatus DecodeT2STRDPreInstruction(MCInst &Inst,unsigned Insn,
481                                uint64_t Address, const void *Decoder);
482 static DecodeStatus DecodeT2Adr(MCInst &Inst, unsigned Val,
483                                 uint64_t Address, const void *Decoder);
484 static DecodeStatus DecodeT2LdStPre(MCInst &Inst, unsigned Val,
485                                 uint64_t Address, const void *Decoder);
486 static DecodeStatus DecodeT2ShifterImmOperand(MCInst &Inst, unsigned Val,
487                                 uint64_t Address, const void *Decoder);
488 
489 static DecodeStatus DecodeLDR(MCInst &Inst, unsigned Val,
490                                 uint64_t Address, const void *Decoder);
491 static DecodeStatus DecoderForMRRC2AndMCRR2(MCInst &Inst, unsigned Val,
492                                             uint64_t Address, const void *Decoder);
493 static DecodeStatus DecodeForVMRSandVMSR(MCInst &Inst, unsigned Val,
494                                          uint64_t Address, const void *Decoder);
495 
496 template <bool isSigned, bool isNeg, bool zeroPermitted, int size>
497 static DecodeStatus DecodeBFLabelOperand(MCInst &Inst, unsigned val,
498                                          uint64_t Address, const void *Decoder);
499 static DecodeStatus DecodeBFAfterTargetOperand(MCInst &Inst, unsigned val,
500                                                uint64_t Address,
501                                                const void *Decoder);
502 static DecodeStatus DecodePredNoALOperand(MCInst &Inst, unsigned Val,
503                                           uint64_t Address,
504                                           const void *Decoder);
505 static DecodeStatus DecodeLOLoop(MCInst &Inst, unsigned Insn, uint64_t Address,
506                                  const void *Decoder);
507 static DecodeStatus DecodeLongShiftOperand(MCInst &Inst, unsigned Val,
508                                            uint64_t Address,
509                                            const void *Decoder);
510 static DecodeStatus DecodeVSCCLRM(MCInst &Inst, unsigned Insn, uint64_t Address,
511                                   const void *Decoder);
512 static DecodeStatus DecodeVPTMaskOperand(MCInst &Inst, unsigned Val,
513                                          uint64_t Address, const void *Decoder);
514 static DecodeStatus DecodeVpredROperand(MCInst &Inst, unsigned Val,
515                                         uint64_t Address, const void *Decoder);
516 static DecodeStatus DecodeRestrictedIPredicateOperand(MCInst &Inst, unsigned Val,
517                                                      uint64_t Address,
518                                                      const void *Decoder);
519 static DecodeStatus DecodeRestrictedSPredicateOperand(MCInst &Inst, unsigned Val,
520                                                      uint64_t Address,
521                                                      const void *Decoder);
522 static DecodeStatus DecodeRestrictedUPredicateOperand(MCInst &Inst, unsigned Val,
523                                                      uint64_t Address,
524                                                      const void *Decoder);
525 static DecodeStatus DecodeRestrictedFPPredicateOperand(MCInst &Inst,
526                                                        unsigned Val,
527                                                        uint64_t Address,
528                                                        const void *Decoder);
529 template<bool Writeback>
530 static DecodeStatus DecodeVSTRVLDR_SYSREG(MCInst &Inst, unsigned Insn,
531                                           uint64_t Address,
532                                           const void *Decoder);
533 template<int shift>
534 static DecodeStatus DecodeMVE_MEM_1_pre(MCInst &Inst, unsigned Val,
535                                         uint64_t Address, const void *Decoder);
536 template<int shift>
537 static DecodeStatus DecodeMVE_MEM_2_pre(MCInst &Inst, unsigned Val,
538                                         uint64_t Address, const void *Decoder);
539 template<int shift>
540 static DecodeStatus DecodeMVE_MEM_3_pre(MCInst &Inst, unsigned Val,
541                                         uint64_t Address, const void *Decoder);
542 template<unsigned MinLog, unsigned MaxLog>
543 static DecodeStatus DecodePowerTwoOperand(MCInst &Inst, unsigned Val,
544                                           uint64_t Address,
545                                           const void *Decoder);
546 template<unsigned start>
547 static DecodeStatus DecodeMVEPairVectorIndexOperand(MCInst &Inst, unsigned Val,
548                                                     uint64_t Address,
549                                                     const void *Decoder);
550 static DecodeStatus DecodeMVEVMOVQtoDReg(MCInst &Inst, unsigned Insn,
551                                          uint64_t Address,
552                                          const void *Decoder);
553 static DecodeStatus DecodeMVEVMOVDRegtoQ(MCInst &Inst, unsigned Insn,
554                                          uint64_t Address,
555                                          const void *Decoder);
556 static DecodeStatus DecodeMVEVCVTt1fp(MCInst &Inst, unsigned Insn,
557                                       uint64_t Address, const void *Decoder);
558 typedef DecodeStatus OperandDecoder(MCInst &Inst, unsigned Val,
559                                     uint64_t Address, const void *Decoder);
560 template<bool scalar, OperandDecoder predicate_decoder>
561 static DecodeStatus DecodeMVEVCMP(MCInst &Inst, unsigned Insn,
562                                   uint64_t Address, const void *Decoder);
563 static DecodeStatus DecodeMveVCTP(MCInst &Inst, unsigned Insn,
564                                   uint64_t Address, const void *Decoder);
565 static DecodeStatus DecodeMVEVPNOT(MCInst &Inst, unsigned Insn,
566                                    uint64_t Address, const void *Decoder);
567 static DecodeStatus DecodeMVEOverlappingLongShift(MCInst &Inst, unsigned Insn,
568                                                   uint64_t Address,
569                                                   const void *Decoder);
570 static DecodeStatus DecodeT2AddSubSPImm(MCInst &Inst, unsigned Insn,
571                                         uint64_t Address, const void *Decoder);
572 
573 #include "ARMGenDisassemblerTables.inc"
574 
575 static MCDisassembler *createARMDisassembler(const Target &T,
576                                              const MCSubtargetInfo &STI,
577                                              MCContext &Ctx) {
578   return new ARMDisassembler(STI, Ctx);
579 }
580 
581 // Post-decoding checks
582 static DecodeStatus checkDecodedInstruction(MCInst &MI, uint64_t &Size,
583                                             uint64_t Address, raw_ostream &CS,
584                                             uint32_t Insn,
585                                             DecodeStatus Result) {
586   switch (MI.getOpcode()) {
587     case ARM::HVC: {
588       // HVC is undefined if condition = 0xf otherwise upredictable
589       // if condition != 0xe
590       uint32_t Cond = (Insn >> 28) & 0xF;
591       if (Cond == 0xF)
592         return MCDisassembler::Fail;
593       if (Cond != 0xE)
594         return MCDisassembler::SoftFail;
595       return Result;
596     }
597     case ARM::t2ADDri:
598     case ARM::t2ADDri12:
599     case ARM::t2ADDrr:
600     case ARM::t2ADDrs:
601     case ARM::t2SUBri:
602     case ARM::t2SUBri12:
603     case ARM::t2SUBrr:
604     case ARM::t2SUBrs:
605       if (MI.getOperand(0).getReg() == ARM::SP &&
606           MI.getOperand(1).getReg() != ARM::SP)
607         return MCDisassembler::SoftFail;
608       return Result;
609     default: return Result;
610   }
611 }
612 
613 DecodeStatus ARMDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
614                                              ArrayRef<uint8_t> Bytes,
615                                              uint64_t Address,
616                                              raw_ostream &CS) const {
617   if (STI.getFeatureBits()[ARM::ModeThumb])
618     return getThumbInstruction(MI, Size, Bytes, Address, CS);
619   return getARMInstruction(MI, Size, Bytes, Address, CS);
620 }
621 
622 DecodeStatus ARMDisassembler::getARMInstruction(MCInst &MI, uint64_t &Size,
623                                                 ArrayRef<uint8_t> Bytes,
624                                                 uint64_t Address,
625                                                 raw_ostream &CS) const {
626   CommentStream = &CS;
627 
628   assert(!STI.getFeatureBits()[ARM::ModeThumb] &&
629          "Asked to disassemble an ARM instruction but Subtarget is in Thumb "
630          "mode!");
631 
632   // We want to read exactly 4 bytes of data.
633   if (Bytes.size() < 4) {
634     Size = 0;
635     return MCDisassembler::Fail;
636   }
637 
638   // Encoded as a small-endian 32-bit word in the stream.
639   uint32_t Insn =
640       (Bytes[3] << 24) | (Bytes[2] << 16) | (Bytes[1] << 8) | (Bytes[0] << 0);
641 
642   // Calling the auto-generated decoder function.
643   DecodeStatus Result =
644       decodeInstruction(DecoderTableARM32, MI, Insn, Address, this, STI);
645   if (Result != MCDisassembler::Fail) {
646     Size = 4;
647     return checkDecodedInstruction(MI, Size, Address, CS, Insn, Result);
648   }
649 
650   struct DecodeTable {
651     const uint8_t *P;
652     bool DecodePred;
653   };
654 
655   const DecodeTable Tables[] = {
656       {DecoderTableVFP32, false},      {DecoderTableVFPV832, false},
657       {DecoderTableNEONData32, true},  {DecoderTableNEONLoadStore32, true},
658       {DecoderTableNEONDup32, true},   {DecoderTablev8NEON32, false},
659       {DecoderTablev8Crypto32, false},
660   };
661 
662   for (auto Table : Tables) {
663     Result = decodeInstruction(Table.P, MI, Insn, Address, this, STI);
664     if (Result != MCDisassembler::Fail) {
665       Size = 4;
666       // Add a fake predicate operand, because we share these instruction
667       // definitions with Thumb2 where these instructions are predicable.
668       if (Table.DecodePred && !DecodePredicateOperand(MI, 0xE, Address, this))
669         return MCDisassembler::Fail;
670       return Result;
671     }
672   }
673 
674   Result =
675       decodeInstruction(DecoderTableCoProc32, MI, Insn, Address, this, STI);
676   if (Result != MCDisassembler::Fail) {
677     Size = 4;
678     return checkDecodedInstruction(MI, Size, Address, CS, Insn, Result);
679   }
680 
681   Size = 4;
682   return MCDisassembler::Fail;
683 }
684 
685 namespace llvm {
686 
687 extern const MCInstrDesc ARMInsts[];
688 
689 } // end namespace llvm
690 
691 /// tryAddingSymbolicOperand - trys to add a symbolic operand in place of the
692 /// immediate Value in the MCInst.  The immediate Value has had any PC
693 /// adjustment made by the caller.  If the instruction is a branch instruction
694 /// then isBranch is true, else false.  If the getOpInfo() function was set as
695 /// part of the setupForSymbolicDisassembly() call then that function is called
696 /// to get any symbolic information at the Address for this instruction.  If
697 /// that returns non-zero then the symbolic information it returns is used to
698 /// create an MCExpr and that is added as an operand to the MCInst.  If
699 /// getOpInfo() returns zero and isBranch is true then a symbol look up for
700 /// Value is done and if a symbol is found an MCExpr is created with that, else
701 /// an MCExpr with Value is created.  This function returns true if it adds an
702 /// operand to the MCInst and false otherwise.
703 static bool tryAddingSymbolicOperand(uint64_t Address, int32_t Value,
704                                      bool isBranch, uint64_t InstSize,
705                                      MCInst &MI, const void *Decoder) {
706   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
707   // FIXME: Does it make sense for value to be negative?
708   return Dis->tryAddingSymbolicOperand(MI, (uint32_t)Value, Address, isBranch,
709                                        /* Offset */ 0, InstSize);
710 }
711 
712 /// tryAddingPcLoadReferenceComment - trys to add a comment as to what is being
713 /// referenced by a load instruction with the base register that is the Pc.
714 /// These can often be values in a literal pool near the Address of the
715 /// instruction.  The Address of the instruction and its immediate Value are
716 /// used as a possible literal pool entry.  The SymbolLookUp call back will
717 /// return the name of a symbol referenced by the literal pool's entry if
718 /// the referenced address is that of a symbol.  Or it will return a pointer to
719 /// a literal 'C' string if the referenced address of the literal pool's entry
720 /// is an address into a section with 'C' string literals.
721 static void tryAddingPcLoadReferenceComment(uint64_t Address, int Value,
722                                             const void *Decoder) {
723   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
724   Dis->tryAddingPcLoadReferenceComment(Value, Address);
725 }
726 
727 // Thumb1 instructions don't have explicit S bits.  Rather, they
728 // implicitly set CPSR.  Since it's not represented in the encoding, the
729 // auto-generated decoder won't inject the CPSR operand.  We need to fix
730 // that as a post-pass.
731 static void AddThumb1SBit(MCInst &MI, bool InITBlock) {
732   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
733   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
734   MCInst::iterator I = MI.begin();
735   for (unsigned i = 0; i < NumOps; ++i, ++I) {
736     if (I == MI.end()) break;
737     if (OpInfo[i].isOptionalDef() && OpInfo[i].RegClass == ARM::CCRRegClassID) {
738       if (i > 0 && OpInfo[i-1].isPredicate()) continue;
739       MI.insert(I, MCOperand::createReg(InITBlock ? 0 : ARM::CPSR));
740       return;
741     }
742   }
743 
744   MI.insert(I, MCOperand::createReg(InITBlock ? 0 : ARM::CPSR));
745 }
746 
747 static bool isVectorPredicable(unsigned Opcode) {
748   const MCOperandInfo *OpInfo = ARMInsts[Opcode].OpInfo;
749   unsigned short NumOps = ARMInsts[Opcode].NumOperands;
750   for (unsigned i = 0; i < NumOps; ++i) {
751     if (ARM::isVpred(OpInfo[i].OperandType))
752       return true;
753   }
754   return false;
755 }
756 
757 // Most Thumb instructions don't have explicit predicates in the
758 // encoding, but rather get their predicates from IT context.  We need
759 // to fix up the predicate operands using this context information as a
760 // post-pass.
761 MCDisassembler::DecodeStatus
762 ARMDisassembler::AddThumbPredicate(MCInst &MI) const {
763   MCDisassembler::DecodeStatus S = Success;
764 
765   const FeatureBitset &FeatureBits = getSubtargetInfo().getFeatureBits();
766 
767   // A few instructions actually have predicates encoded in them.  Don't
768   // try to overwrite it if we're seeing one of those.
769   switch (MI.getOpcode()) {
770     case ARM::tBcc:
771     case ARM::t2Bcc:
772     case ARM::tCBZ:
773     case ARM::tCBNZ:
774     case ARM::tCPS:
775     case ARM::t2CPS3p:
776     case ARM::t2CPS2p:
777     case ARM::t2CPS1p:
778     case ARM::t2CSEL:
779     case ARM::t2CSINC:
780     case ARM::t2CSINV:
781     case ARM::t2CSNEG:
782     case ARM::tMOVSr:
783     case ARM::tSETEND:
784       // Some instructions (mostly conditional branches) are not
785       // allowed in IT blocks.
786       if (ITBlock.instrInITBlock())
787         S = SoftFail;
788       else
789         return Success;
790       break;
791     case ARM::t2HINT:
792       if (MI.getOperand(0).getImm() == 0x10 && (FeatureBits[ARM::FeatureRAS]) != 0)
793         S = SoftFail;
794       break;
795     case ARM::tB:
796     case ARM::t2B:
797     case ARM::t2TBB:
798     case ARM::t2TBH:
799       // Some instructions (mostly unconditional branches) can
800       // only appears at the end of, or outside of, an IT.
801       if (ITBlock.instrInITBlock() && !ITBlock.instrLastInITBlock())
802         S = SoftFail;
803       break;
804     default:
805       break;
806   }
807 
808   // Warn on non-VPT predicable instruction in a VPT block and a VPT
809   // predicable instruction in an IT block
810   if ((!isVectorPredicable(MI.getOpcode()) && VPTBlock.instrInVPTBlock()) ||
811        (isVectorPredicable(MI.getOpcode()) && ITBlock.instrInITBlock()))
812     S = SoftFail;
813 
814   // If we're in an IT/VPT block, base the predicate on that.  Otherwise,
815   // assume a predicate of AL.
816   unsigned CC = ARMCC::AL;
817   unsigned VCC = ARMVCC::None;
818   if (ITBlock.instrInITBlock()) {
819     CC = ITBlock.getITCC();
820     ITBlock.advanceITState();
821   } else if (VPTBlock.instrInVPTBlock()) {
822     VCC = VPTBlock.getVPTPred();
823     VPTBlock.advanceVPTState();
824   }
825 
826   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
827   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
828 
829   MCInst::iterator CCI = MI.begin();
830   for (unsigned i = 0; i < NumOps; ++i, ++CCI) {
831     if (OpInfo[i].isPredicate() || CCI == MI.end()) break;
832   }
833 
834   if (ARMInsts[MI.getOpcode()].isPredicable()) {
835     CCI = MI.insert(CCI, MCOperand::createImm(CC));
836     ++CCI;
837     if (CC == ARMCC::AL)
838       MI.insert(CCI, MCOperand::createReg(0));
839     else
840       MI.insert(CCI, MCOperand::createReg(ARM::CPSR));
841   } else if (CC != ARMCC::AL) {
842     Check(S, SoftFail);
843   }
844 
845   MCInst::iterator VCCI = MI.begin();
846   unsigned VCCPos;
847   for (VCCPos = 0; VCCPos < NumOps; ++VCCPos, ++VCCI) {
848     if (ARM::isVpred(OpInfo[VCCPos].OperandType) || VCCI == MI.end()) break;
849   }
850 
851   if (isVectorPredicable(MI.getOpcode())) {
852     VCCI = MI.insert(VCCI, MCOperand::createImm(VCC));
853     ++VCCI;
854     if (VCC == ARMVCC::None)
855       MI.insert(VCCI, MCOperand::createReg(0));
856     else
857       MI.insert(VCCI, MCOperand::createReg(ARM::P0));
858     if (OpInfo[VCCPos].OperandType == ARM::OPERAND_VPRED_R) {
859       int TiedOp = ARMInsts[MI.getOpcode()].getOperandConstraint(
860         VCCPos + 2, MCOI::TIED_TO);
861       assert(TiedOp >= 0 &&
862              "Inactive register in vpred_r is not tied to an output!");
863       // Copy the operand to ensure it's not invalidated when MI grows.
864       MI.insert(VCCI, MCOperand(MI.getOperand(TiedOp)));
865     }
866   } else if (VCC != ARMVCC::None) {
867     Check(S, SoftFail);
868   }
869 
870   return S;
871 }
872 
873 // Thumb VFP instructions are a special case.  Because we share their
874 // encodings between ARM and Thumb modes, and they are predicable in ARM
875 // mode, the auto-generated decoder will give them an (incorrect)
876 // predicate operand.  We need to rewrite these operands based on the IT
877 // context as a post-pass.
878 void ARMDisassembler::UpdateThumbVFPPredicate(
879   DecodeStatus &S, MCInst &MI) const {
880   unsigned CC;
881   CC = ITBlock.getITCC();
882   if (CC == 0xF)
883     CC = ARMCC::AL;
884   if (ITBlock.instrInITBlock())
885     ITBlock.advanceITState();
886   else if (VPTBlock.instrInVPTBlock()) {
887     CC = VPTBlock.getVPTPred();
888     VPTBlock.advanceVPTState();
889   }
890 
891   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
892   MCInst::iterator I = MI.begin();
893   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
894   for (unsigned i = 0; i < NumOps; ++i, ++I) {
895     if (OpInfo[i].isPredicate() ) {
896       if (CC != ARMCC::AL && !ARMInsts[MI.getOpcode()].isPredicable())
897         Check(S, SoftFail);
898       I->setImm(CC);
899       ++I;
900       if (CC == ARMCC::AL)
901         I->setReg(0);
902       else
903         I->setReg(ARM::CPSR);
904       return;
905     }
906   }
907 }
908 
909 DecodeStatus ARMDisassembler::getThumbInstruction(MCInst &MI, uint64_t &Size,
910                                                   ArrayRef<uint8_t> Bytes,
911                                                   uint64_t Address,
912                                                   raw_ostream &CS) const {
913   CommentStream = &CS;
914 
915   assert(STI.getFeatureBits()[ARM::ModeThumb] &&
916          "Asked to disassemble in Thumb mode but Subtarget is in ARM mode!");
917 
918   // We want to read exactly 2 bytes of data.
919   if (Bytes.size() < 2) {
920     Size = 0;
921     return MCDisassembler::Fail;
922   }
923 
924   uint16_t Insn16 = (Bytes[1] << 8) | Bytes[0];
925   DecodeStatus Result =
926       decodeInstruction(DecoderTableThumb16, MI, Insn16, Address, this, STI);
927   if (Result != MCDisassembler::Fail) {
928     Size = 2;
929     Check(Result, AddThumbPredicate(MI));
930     return Result;
931   }
932 
933   Result = decodeInstruction(DecoderTableThumbSBit16, MI, Insn16, Address, this,
934                              STI);
935   if (Result) {
936     Size = 2;
937     bool InITBlock = ITBlock.instrInITBlock();
938     Check(Result, AddThumbPredicate(MI));
939     AddThumb1SBit(MI, InITBlock);
940     return Result;
941   }
942 
943   Result =
944       decodeInstruction(DecoderTableThumb216, MI, Insn16, Address, this, STI);
945   if (Result != MCDisassembler::Fail) {
946     Size = 2;
947 
948     // Nested IT blocks are UNPREDICTABLE.  Must be checked before we add
949     // the Thumb predicate.
950     if (MI.getOpcode() == ARM::t2IT && ITBlock.instrInITBlock())
951       Result = MCDisassembler::SoftFail;
952 
953     Check(Result, AddThumbPredicate(MI));
954 
955     // If we find an IT instruction, we need to parse its condition
956     // code and mask operands so that we can apply them correctly
957     // to the subsequent instructions.
958     if (MI.getOpcode() == ARM::t2IT) {
959       unsigned Firstcond = MI.getOperand(0).getImm();
960       unsigned Mask = MI.getOperand(1).getImm();
961       ITBlock.setITState(Firstcond, Mask);
962 
963       // An IT instruction that would give a 'NV' predicate is unpredictable.
964       if (Firstcond == ARMCC::AL && !isPowerOf2_32(Mask))
965         CS << "unpredictable IT predicate sequence";
966     }
967 
968     return Result;
969   }
970 
971   // We want to read exactly 4 bytes of data.
972   if (Bytes.size() < 4) {
973     Size = 0;
974     return MCDisassembler::Fail;
975   }
976 
977   uint32_t Insn32 =
978       (Bytes[3] << 8) | (Bytes[2] << 0) | (Bytes[1] << 24) | (Bytes[0] << 16);
979 
980   Result =
981       decodeInstruction(DecoderTableMVE32, MI, Insn32, Address, this, STI);
982   if (Result != MCDisassembler::Fail) {
983     Size = 4;
984 
985     // Nested VPT blocks are UNPREDICTABLE. Must be checked before we add
986     // the VPT predicate.
987     if (isVPTOpcode(MI.getOpcode()) && VPTBlock.instrInVPTBlock())
988       Result = MCDisassembler::SoftFail;
989 
990     Check(Result, AddThumbPredicate(MI));
991 
992     if (isVPTOpcode(MI.getOpcode())) {
993       unsigned Mask = MI.getOperand(0).getImm();
994       VPTBlock.setVPTState(Mask);
995     }
996 
997     return Result;
998   }
999 
1000   Result =
1001       decodeInstruction(DecoderTableThumb32, MI, Insn32, Address, this, STI);
1002   if (Result != MCDisassembler::Fail) {
1003     Size = 4;
1004     bool InITBlock = ITBlock.instrInITBlock();
1005     Check(Result, AddThumbPredicate(MI));
1006     AddThumb1SBit(MI, InITBlock);
1007     return Result;
1008   }
1009 
1010   Result =
1011       decodeInstruction(DecoderTableThumb232, MI, Insn32, Address, this, STI);
1012   if (Result != MCDisassembler::Fail) {
1013     Size = 4;
1014     Check(Result, AddThumbPredicate(MI));
1015     return checkDecodedInstruction(MI, Size, Address, CS, Insn32, Result);
1016   }
1017 
1018   if (fieldFromInstruction(Insn32, 28, 4) == 0xE) {
1019     Result =
1020         decodeInstruction(DecoderTableVFP32, MI, Insn32, Address, this, STI);
1021     if (Result != MCDisassembler::Fail) {
1022       Size = 4;
1023       UpdateThumbVFPPredicate(Result, MI);
1024       return Result;
1025     }
1026   }
1027 
1028   Result =
1029       decodeInstruction(DecoderTableVFPV832, MI, Insn32, Address, this, STI);
1030   if (Result != MCDisassembler::Fail) {
1031     Size = 4;
1032     return Result;
1033   }
1034 
1035   if (fieldFromInstruction(Insn32, 28, 4) == 0xE) {
1036     Result = decodeInstruction(DecoderTableNEONDup32, MI, Insn32, Address, this,
1037                                STI);
1038     if (Result != MCDisassembler::Fail) {
1039       Size = 4;
1040       Check(Result, AddThumbPredicate(MI));
1041       return Result;
1042     }
1043   }
1044 
1045   if (fieldFromInstruction(Insn32, 24, 8) == 0xF9) {
1046     uint32_t NEONLdStInsn = Insn32;
1047     NEONLdStInsn &= 0xF0FFFFFF;
1048     NEONLdStInsn |= 0x04000000;
1049     Result = decodeInstruction(DecoderTableNEONLoadStore32, MI, NEONLdStInsn,
1050                                Address, this, STI);
1051     if (Result != MCDisassembler::Fail) {
1052       Size = 4;
1053       Check(Result, AddThumbPredicate(MI));
1054       return Result;
1055     }
1056   }
1057 
1058   if (fieldFromInstruction(Insn32, 24, 4) == 0xF) {
1059     uint32_t NEONDataInsn = Insn32;
1060     NEONDataInsn &= 0xF0FFFFFF; // Clear bits 27-24
1061     NEONDataInsn |= (NEONDataInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
1062     NEONDataInsn |= 0x12000000; // Set bits 28 and 25
1063     Result = decodeInstruction(DecoderTableNEONData32, MI, NEONDataInsn,
1064                                Address, this, STI);
1065     if (Result != MCDisassembler::Fail) {
1066       Size = 4;
1067       Check(Result, AddThumbPredicate(MI));
1068       return Result;
1069     }
1070 
1071     uint32_t NEONCryptoInsn = Insn32;
1072     NEONCryptoInsn &= 0xF0FFFFFF; // Clear bits 27-24
1073     NEONCryptoInsn |= (NEONCryptoInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
1074     NEONCryptoInsn |= 0x12000000; // Set bits 28 and 25
1075     Result = decodeInstruction(DecoderTablev8Crypto32, MI, NEONCryptoInsn,
1076                                Address, this, STI);
1077     if (Result != MCDisassembler::Fail) {
1078       Size = 4;
1079       return Result;
1080     }
1081 
1082     uint32_t NEONv8Insn = Insn32;
1083     NEONv8Insn &= 0xF3FFFFFF; // Clear bits 27-26
1084     Result = decodeInstruction(DecoderTablev8NEON32, MI, NEONv8Insn, Address,
1085                                this, STI);
1086     if (Result != MCDisassembler::Fail) {
1087       Size = 4;
1088       return Result;
1089     }
1090   }
1091 
1092   uint32_t Coproc = fieldFromInstruction(Insn32, 8, 4);
1093   const uint8_t *DecoderTable = ARM::isCDECoproc(Coproc, STI)
1094                                     ? DecoderTableThumb2CDE32
1095                                     : DecoderTableThumb2CoProc32;
1096   Result =
1097       decodeInstruction(DecoderTable, MI, Insn32, Address, this, STI);
1098   if (Result != MCDisassembler::Fail) {
1099     Size = 4;
1100     Check(Result, AddThumbPredicate(MI));
1101     return Result;
1102   }
1103 
1104   Size = 0;
1105   return MCDisassembler::Fail;
1106 }
1107 
1108 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeARMDisassembler() {
1109   TargetRegistry::RegisterMCDisassembler(getTheARMLETarget(),
1110                                          createARMDisassembler);
1111   TargetRegistry::RegisterMCDisassembler(getTheARMBETarget(),
1112                                          createARMDisassembler);
1113   TargetRegistry::RegisterMCDisassembler(getTheThumbLETarget(),
1114                                          createARMDisassembler);
1115   TargetRegistry::RegisterMCDisassembler(getTheThumbBETarget(),
1116                                          createARMDisassembler);
1117 }
1118 
1119 static const uint16_t GPRDecoderTable[] = {
1120   ARM::R0, ARM::R1, ARM::R2, ARM::R3,
1121   ARM::R4, ARM::R5, ARM::R6, ARM::R7,
1122   ARM::R8, ARM::R9, ARM::R10, ARM::R11,
1123   ARM::R12, ARM::SP, ARM::LR, ARM::PC
1124 };
1125 
1126 static const uint16_t CLRMGPRDecoderTable[] = {
1127   ARM::R0, ARM::R1, ARM::R2, ARM::R3,
1128   ARM::R4, ARM::R5, ARM::R6, ARM::R7,
1129   ARM::R8, ARM::R9, ARM::R10, ARM::R11,
1130   ARM::R12, 0, ARM::LR, ARM::APSR
1131 };
1132 
1133 static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1134                                    uint64_t Address, const void *Decoder) {
1135   if (RegNo > 15)
1136     return MCDisassembler::Fail;
1137 
1138   unsigned Register = GPRDecoderTable[RegNo];
1139   Inst.addOperand(MCOperand::createReg(Register));
1140   return MCDisassembler::Success;
1141 }
1142 
1143 static DecodeStatus DecodeCLRMGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1144                                                uint64_t Address,
1145                                                const void *Decoder) {
1146   if (RegNo > 15)
1147     return MCDisassembler::Fail;
1148 
1149   unsigned Register = CLRMGPRDecoderTable[RegNo];
1150   if (Register == 0)
1151     return MCDisassembler::Fail;
1152 
1153   Inst.addOperand(MCOperand::createReg(Register));
1154   return MCDisassembler::Success;
1155 }
1156 
1157 static DecodeStatus
1158 DecodeGPRnopcRegisterClass(MCInst &Inst, unsigned RegNo,
1159                            uint64_t Address, const void *Decoder) {
1160   DecodeStatus S = MCDisassembler::Success;
1161 
1162   if (RegNo == 15)
1163     S = MCDisassembler::SoftFail;
1164 
1165   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1166 
1167   return S;
1168 }
1169 
1170 static DecodeStatus
1171 DecodeGPRwithAPSRRegisterClass(MCInst &Inst, unsigned RegNo,
1172                                uint64_t Address, const void *Decoder) {
1173   DecodeStatus S = MCDisassembler::Success;
1174 
1175   if (RegNo == 15)
1176   {
1177     Inst.addOperand(MCOperand::createReg(ARM::APSR_NZCV));
1178     return MCDisassembler::Success;
1179   }
1180 
1181   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1182   return S;
1183 }
1184 
1185 static DecodeStatus
1186 DecodeGPRwithZRRegisterClass(MCInst &Inst, unsigned RegNo,
1187                              uint64_t Address, const void *Decoder) {
1188   DecodeStatus S = MCDisassembler::Success;
1189 
1190   if (RegNo == 15)
1191   {
1192     Inst.addOperand(MCOperand::createReg(ARM::ZR));
1193     return MCDisassembler::Success;
1194   }
1195 
1196   if (RegNo == 13)
1197     Check(S, MCDisassembler::SoftFail);
1198 
1199   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1200   return S;
1201 }
1202 
1203 static DecodeStatus
1204 DecodeGPRwithZRnospRegisterClass(MCInst &Inst, unsigned RegNo,
1205                                  uint64_t Address, const void *Decoder) {
1206   DecodeStatus S = MCDisassembler::Success;
1207   if (RegNo == 13)
1208     return MCDisassembler::Fail;
1209   Check(S, DecodeGPRwithZRRegisterClass(Inst, RegNo, Address, Decoder));
1210   return S;
1211 }
1212 
1213 static DecodeStatus DecodetGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1214                                    uint64_t Address, const void *Decoder) {
1215   if (RegNo > 7)
1216     return MCDisassembler::Fail;
1217   return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
1218 }
1219 
1220 static const uint16_t GPRPairDecoderTable[] = {
1221   ARM::R0_R1, ARM::R2_R3,   ARM::R4_R5,  ARM::R6_R7,
1222   ARM::R8_R9, ARM::R10_R11, ARM::R12_SP
1223 };
1224 
1225 static DecodeStatus DecodeGPRPairRegisterClass(MCInst &Inst, unsigned RegNo,
1226                                    uint64_t Address, const void *Decoder) {
1227   DecodeStatus S = MCDisassembler::Success;
1228 
1229   // According to the Arm ARM RegNo = 14 is undefined, but we return fail
1230   // rather than SoftFail as there is no GPRPair table entry for index 7.
1231   if (RegNo > 13)
1232     return MCDisassembler::Fail;
1233 
1234   if (RegNo & 1)
1235      S = MCDisassembler::SoftFail;
1236 
1237   unsigned RegisterPair = GPRPairDecoderTable[RegNo/2];
1238   Inst.addOperand(MCOperand::createReg(RegisterPair));
1239   return S;
1240 }
1241 
1242 static DecodeStatus DecodeGPRPairnospRegisterClass(MCInst &Inst, unsigned RegNo,
1243                                    uint64_t Address, const void *Decoder) {
1244   if (RegNo > 13)
1245     return MCDisassembler::Fail;
1246 
1247   unsigned RegisterPair = GPRPairDecoderTable[RegNo/2];
1248   Inst.addOperand(MCOperand::createReg(RegisterPair));
1249 
1250   if ((RegNo & 1) || RegNo > 10)
1251      return MCDisassembler::SoftFail;
1252   return MCDisassembler::Success;
1253 }
1254 
1255 static DecodeStatus DecodeGPRspRegisterClass(MCInst &Inst, unsigned RegNo,
1256                                              uint64_t Address,
1257                                              const void *Decoder) {
1258   if (RegNo != 13)
1259     return MCDisassembler::Fail;
1260 
1261   unsigned Register = GPRDecoderTable[RegNo];
1262   Inst.addOperand(MCOperand::createReg(Register));
1263   return MCDisassembler::Success;
1264 }
1265 
1266 static DecodeStatus DecodetcGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1267                                    uint64_t Address, const void *Decoder) {
1268   unsigned Register = 0;
1269   switch (RegNo) {
1270     case 0:
1271       Register = ARM::R0;
1272       break;
1273     case 1:
1274       Register = ARM::R1;
1275       break;
1276     case 2:
1277       Register = ARM::R2;
1278       break;
1279     case 3:
1280       Register = ARM::R3;
1281       break;
1282     case 9:
1283       Register = ARM::R9;
1284       break;
1285     case 12:
1286       Register = ARM::R12;
1287       break;
1288     default:
1289       return MCDisassembler::Fail;
1290     }
1291 
1292   Inst.addOperand(MCOperand::createReg(Register));
1293   return MCDisassembler::Success;
1294 }
1295 
1296 static DecodeStatus DecoderGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1297                                    uint64_t Address, const void *Decoder) {
1298   DecodeStatus S = MCDisassembler::Success;
1299 
1300   const FeatureBitset &featureBits =
1301     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1302 
1303   if ((RegNo == 13 && !featureBits[ARM::HasV8Ops]) || RegNo == 15)
1304     S = MCDisassembler::SoftFail;
1305 
1306   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1307   return S;
1308 }
1309 
1310 static const uint16_t SPRDecoderTable[] = {
1311      ARM::S0,  ARM::S1,  ARM::S2,  ARM::S3,
1312      ARM::S4,  ARM::S5,  ARM::S6,  ARM::S7,
1313      ARM::S8,  ARM::S9, ARM::S10, ARM::S11,
1314     ARM::S12, ARM::S13, ARM::S14, ARM::S15,
1315     ARM::S16, ARM::S17, ARM::S18, ARM::S19,
1316     ARM::S20, ARM::S21, ARM::S22, ARM::S23,
1317     ARM::S24, ARM::S25, ARM::S26, ARM::S27,
1318     ARM::S28, ARM::S29, ARM::S30, ARM::S31
1319 };
1320 
1321 static DecodeStatus DecodeSPRRegisterClass(MCInst &Inst, unsigned RegNo,
1322                                    uint64_t Address, const void *Decoder) {
1323   if (RegNo > 31)
1324     return MCDisassembler::Fail;
1325 
1326   unsigned Register = SPRDecoderTable[RegNo];
1327   Inst.addOperand(MCOperand::createReg(Register));
1328   return MCDisassembler::Success;
1329 }
1330 
1331 static DecodeStatus DecodeHPRRegisterClass(MCInst &Inst, unsigned RegNo,
1332                                    uint64_t Address, const void *Decoder) {
1333   return DecodeSPRRegisterClass(Inst, RegNo, Address, Decoder);
1334 }
1335 
1336 static const uint16_t DPRDecoderTable[] = {
1337      ARM::D0,  ARM::D1,  ARM::D2,  ARM::D3,
1338      ARM::D4,  ARM::D5,  ARM::D6,  ARM::D7,
1339      ARM::D8,  ARM::D9, ARM::D10, ARM::D11,
1340     ARM::D12, ARM::D13, ARM::D14, ARM::D15,
1341     ARM::D16, ARM::D17, ARM::D18, ARM::D19,
1342     ARM::D20, ARM::D21, ARM::D22, ARM::D23,
1343     ARM::D24, ARM::D25, ARM::D26, ARM::D27,
1344     ARM::D28, ARM::D29, ARM::D30, ARM::D31
1345 };
1346 
1347 static DecodeStatus DecodeDPRRegisterClass(MCInst &Inst, unsigned RegNo,
1348                                    uint64_t Address, const void *Decoder) {
1349   const FeatureBitset &featureBits =
1350     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1351 
1352   bool hasD32 = featureBits[ARM::FeatureD32];
1353 
1354   if (RegNo > 31 || (!hasD32 && RegNo > 15))
1355     return MCDisassembler::Fail;
1356 
1357   unsigned Register = DPRDecoderTable[RegNo];
1358   Inst.addOperand(MCOperand::createReg(Register));
1359   return MCDisassembler::Success;
1360 }
1361 
1362 static DecodeStatus DecodeDPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
1363                                    uint64_t Address, const void *Decoder) {
1364   if (RegNo > 7)
1365     return MCDisassembler::Fail;
1366   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
1367 }
1368 
1369 static DecodeStatus DecodeSPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
1370                                    uint64_t Address, const void *Decoder) {
1371   if (RegNo > 15)
1372     return MCDisassembler::Fail;
1373   return DecodeSPRRegisterClass(Inst, RegNo, Address, Decoder);
1374 }
1375 
1376 static DecodeStatus
1377 DecodeDPR_VFP2RegisterClass(MCInst &Inst, unsigned RegNo,
1378                             uint64_t Address, const void *Decoder) {
1379   if (RegNo > 15)
1380     return MCDisassembler::Fail;
1381   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
1382 }
1383 
1384 static const uint16_t QPRDecoderTable[] = {
1385      ARM::Q0,  ARM::Q1,  ARM::Q2,  ARM::Q3,
1386      ARM::Q4,  ARM::Q5,  ARM::Q6,  ARM::Q7,
1387      ARM::Q8,  ARM::Q9, ARM::Q10, ARM::Q11,
1388     ARM::Q12, ARM::Q13, ARM::Q14, ARM::Q15
1389 };
1390 
1391 static DecodeStatus DecodeQPRRegisterClass(MCInst &Inst, unsigned RegNo,
1392                                    uint64_t Address, const void *Decoder) {
1393   if (RegNo > 31 || (RegNo & 1) != 0)
1394     return MCDisassembler::Fail;
1395   RegNo >>= 1;
1396 
1397   unsigned Register = QPRDecoderTable[RegNo];
1398   Inst.addOperand(MCOperand::createReg(Register));
1399   return MCDisassembler::Success;
1400 }
1401 
1402 static const uint16_t DPairDecoderTable[] = {
1403   ARM::Q0,  ARM::D1_D2,   ARM::Q1,  ARM::D3_D4,   ARM::Q2,  ARM::D5_D6,
1404   ARM::Q3,  ARM::D7_D8,   ARM::Q4,  ARM::D9_D10,  ARM::Q5,  ARM::D11_D12,
1405   ARM::Q6,  ARM::D13_D14, ARM::Q7,  ARM::D15_D16, ARM::Q8,  ARM::D17_D18,
1406   ARM::Q9,  ARM::D19_D20, ARM::Q10, ARM::D21_D22, ARM::Q11, ARM::D23_D24,
1407   ARM::Q12, ARM::D25_D26, ARM::Q13, ARM::D27_D28, ARM::Q14, ARM::D29_D30,
1408   ARM::Q15
1409 };
1410 
1411 static DecodeStatus DecodeDPairRegisterClass(MCInst &Inst, unsigned RegNo,
1412                                    uint64_t Address, const void *Decoder) {
1413   if (RegNo > 30)
1414     return MCDisassembler::Fail;
1415 
1416   unsigned Register = DPairDecoderTable[RegNo];
1417   Inst.addOperand(MCOperand::createReg(Register));
1418   return MCDisassembler::Success;
1419 }
1420 
1421 static const uint16_t DPairSpacedDecoderTable[] = {
1422   ARM::D0_D2,   ARM::D1_D3,   ARM::D2_D4,   ARM::D3_D5,
1423   ARM::D4_D6,   ARM::D5_D7,   ARM::D6_D8,   ARM::D7_D9,
1424   ARM::D8_D10,  ARM::D9_D11,  ARM::D10_D12, ARM::D11_D13,
1425   ARM::D12_D14, ARM::D13_D15, ARM::D14_D16, ARM::D15_D17,
1426   ARM::D16_D18, ARM::D17_D19, ARM::D18_D20, ARM::D19_D21,
1427   ARM::D20_D22, ARM::D21_D23, ARM::D22_D24, ARM::D23_D25,
1428   ARM::D24_D26, ARM::D25_D27, ARM::D26_D28, ARM::D27_D29,
1429   ARM::D28_D30, ARM::D29_D31
1430 };
1431 
1432 static DecodeStatus DecodeDPairSpacedRegisterClass(MCInst &Inst,
1433                                                    unsigned RegNo,
1434                                                    uint64_t Address,
1435                                                    const void *Decoder) {
1436   if (RegNo > 29)
1437     return MCDisassembler::Fail;
1438 
1439   unsigned Register = DPairSpacedDecoderTable[RegNo];
1440   Inst.addOperand(MCOperand::createReg(Register));
1441   return MCDisassembler::Success;
1442 }
1443 
1444 static DecodeStatus DecodePredicateOperand(MCInst &Inst, unsigned Val,
1445                                uint64_t Address, const void *Decoder) {
1446   DecodeStatus S = MCDisassembler::Success;
1447   if (Val == 0xF) return MCDisassembler::Fail;
1448   // AL predicate is not allowed on Thumb1 branches.
1449   if (Inst.getOpcode() == ARM::tBcc && Val == 0xE)
1450     return MCDisassembler::Fail;
1451   if (Val != ARMCC::AL && !ARMInsts[Inst.getOpcode()].isPredicable())
1452     Check(S, MCDisassembler::SoftFail);
1453   Inst.addOperand(MCOperand::createImm(Val));
1454   if (Val == ARMCC::AL) {
1455     Inst.addOperand(MCOperand::createReg(0));
1456   } else
1457     Inst.addOperand(MCOperand::createReg(ARM::CPSR));
1458   return S;
1459 }
1460 
1461 static DecodeStatus DecodeCCOutOperand(MCInst &Inst, unsigned Val,
1462                                uint64_t Address, const void *Decoder) {
1463   if (Val)
1464     Inst.addOperand(MCOperand::createReg(ARM::CPSR));
1465   else
1466     Inst.addOperand(MCOperand::createReg(0));
1467   return MCDisassembler::Success;
1468 }
1469 
1470 static DecodeStatus DecodeSORegImmOperand(MCInst &Inst, unsigned Val,
1471                                uint64_t Address, const void *Decoder) {
1472   DecodeStatus S = MCDisassembler::Success;
1473 
1474   unsigned Rm = fieldFromInstruction(Val, 0, 4);
1475   unsigned type = fieldFromInstruction(Val, 5, 2);
1476   unsigned imm = fieldFromInstruction(Val, 7, 5);
1477 
1478   // Register-immediate
1479   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
1480     return MCDisassembler::Fail;
1481 
1482   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1483   switch (type) {
1484     case 0:
1485       Shift = ARM_AM::lsl;
1486       break;
1487     case 1:
1488       Shift = ARM_AM::lsr;
1489       break;
1490     case 2:
1491       Shift = ARM_AM::asr;
1492       break;
1493     case 3:
1494       Shift = ARM_AM::ror;
1495       break;
1496   }
1497 
1498   if (Shift == ARM_AM::ror && imm == 0)
1499     Shift = ARM_AM::rrx;
1500 
1501   unsigned Op = Shift | (imm << 3);
1502   Inst.addOperand(MCOperand::createImm(Op));
1503 
1504   return S;
1505 }
1506 
1507 static DecodeStatus DecodeSORegRegOperand(MCInst &Inst, unsigned Val,
1508                                uint64_t Address, const void *Decoder) {
1509   DecodeStatus S = MCDisassembler::Success;
1510 
1511   unsigned Rm = fieldFromInstruction(Val, 0, 4);
1512   unsigned type = fieldFromInstruction(Val, 5, 2);
1513   unsigned Rs = fieldFromInstruction(Val, 8, 4);
1514 
1515   // Register-register
1516   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1517     return MCDisassembler::Fail;
1518   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rs, Address, Decoder)))
1519     return MCDisassembler::Fail;
1520 
1521   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1522   switch (type) {
1523     case 0:
1524       Shift = ARM_AM::lsl;
1525       break;
1526     case 1:
1527       Shift = ARM_AM::lsr;
1528       break;
1529     case 2:
1530       Shift = ARM_AM::asr;
1531       break;
1532     case 3:
1533       Shift = ARM_AM::ror;
1534       break;
1535   }
1536 
1537   Inst.addOperand(MCOperand::createImm(Shift));
1538 
1539   return S;
1540 }
1541 
1542 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Val,
1543                                  uint64_t Address, const void *Decoder) {
1544   DecodeStatus S = MCDisassembler::Success;
1545 
1546   bool NeedDisjointWriteback = false;
1547   unsigned WritebackReg = 0;
1548   bool CLRM = false;
1549   switch (Inst.getOpcode()) {
1550   default:
1551     break;
1552   case ARM::LDMIA_UPD:
1553   case ARM::LDMDB_UPD:
1554   case ARM::LDMIB_UPD:
1555   case ARM::LDMDA_UPD:
1556   case ARM::t2LDMIA_UPD:
1557   case ARM::t2LDMDB_UPD:
1558   case ARM::t2STMIA_UPD:
1559   case ARM::t2STMDB_UPD:
1560     NeedDisjointWriteback = true;
1561     WritebackReg = Inst.getOperand(0).getReg();
1562     break;
1563   case ARM::t2CLRM:
1564     CLRM = true;
1565     break;
1566   }
1567 
1568   // Empty register lists are not allowed.
1569   if (Val == 0) return MCDisassembler::Fail;
1570   for (unsigned i = 0; i < 16; ++i) {
1571     if (Val & (1 << i)) {
1572       if (CLRM) {
1573         if (!Check(S, DecodeCLRMGPRRegisterClass(Inst, i, Address, Decoder))) {
1574           return MCDisassembler::Fail;
1575         }
1576       } else {
1577         if (!Check(S, DecodeGPRRegisterClass(Inst, i, Address, Decoder)))
1578           return MCDisassembler::Fail;
1579         // Writeback not allowed if Rn is in the target list.
1580         if (NeedDisjointWriteback && WritebackReg == Inst.end()[-1].getReg())
1581           Check(S, MCDisassembler::SoftFail);
1582       }
1583     }
1584   }
1585 
1586   return S;
1587 }
1588 
1589 static DecodeStatus DecodeSPRRegListOperand(MCInst &Inst, unsigned Val,
1590                                  uint64_t Address, const void *Decoder) {
1591   DecodeStatus S = MCDisassembler::Success;
1592 
1593   unsigned Vd = fieldFromInstruction(Val, 8, 5);
1594   unsigned regs = fieldFromInstruction(Val, 0, 8);
1595 
1596   // In case of unpredictable encoding, tweak the operands.
1597   if (regs == 0 || (Vd + regs) > 32) {
1598     regs = Vd + regs > 32 ? 32 - Vd : regs;
1599     regs = std::max( 1u, regs);
1600     S = MCDisassembler::SoftFail;
1601   }
1602 
1603   if (!Check(S, DecodeSPRRegisterClass(Inst, Vd, Address, Decoder)))
1604     return MCDisassembler::Fail;
1605   for (unsigned i = 0; i < (regs - 1); ++i) {
1606     if (!Check(S, DecodeSPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1607       return MCDisassembler::Fail;
1608   }
1609 
1610   return S;
1611 }
1612 
1613 static DecodeStatus DecodeDPRRegListOperand(MCInst &Inst, unsigned Val,
1614                                  uint64_t Address, const void *Decoder) {
1615   DecodeStatus S = MCDisassembler::Success;
1616 
1617   unsigned Vd = fieldFromInstruction(Val, 8, 5);
1618   unsigned regs = fieldFromInstruction(Val, 1, 7);
1619 
1620   // In case of unpredictable encoding, tweak the operands.
1621   if (regs == 0 || regs > 16 || (Vd + regs) > 32) {
1622     regs = Vd + regs > 32 ? 32 - Vd : regs;
1623     regs = std::max( 1u, regs);
1624     regs = std::min(16u, regs);
1625     S = MCDisassembler::SoftFail;
1626   }
1627 
1628   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
1629       return MCDisassembler::Fail;
1630   for (unsigned i = 0; i < (regs - 1); ++i) {
1631     if (!Check(S, DecodeDPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1632       return MCDisassembler::Fail;
1633   }
1634 
1635   return S;
1636 }
1637 
1638 static DecodeStatus DecodeBitfieldMaskOperand(MCInst &Inst, unsigned Val,
1639                                       uint64_t Address, const void *Decoder) {
1640   // This operand encodes a mask of contiguous zeros between a specified MSB
1641   // and LSB.  To decode it, we create the mask of all bits MSB-and-lower,
1642   // the mask of all bits LSB-and-lower, and then xor them to create
1643   // the mask of that's all ones on [msb, lsb].  Finally we not it to
1644   // create the final mask.
1645   unsigned msb = fieldFromInstruction(Val, 5, 5);
1646   unsigned lsb = fieldFromInstruction(Val, 0, 5);
1647 
1648   DecodeStatus S = MCDisassembler::Success;
1649   if (lsb > msb) {
1650     Check(S, MCDisassembler::SoftFail);
1651     // The check above will cause the warning for the "potentially undefined
1652     // instruction encoding" but we can't build a bad MCOperand value here
1653     // with a lsb > msb or else printing the MCInst will cause a crash.
1654     lsb = msb;
1655   }
1656 
1657   uint32_t msb_mask = 0xFFFFFFFF;
1658   if (msb != 31) msb_mask = (1U << (msb+1)) - 1;
1659   uint32_t lsb_mask = (1U << lsb) - 1;
1660 
1661   Inst.addOperand(MCOperand::createImm(~(msb_mask ^ lsb_mask)));
1662   return S;
1663 }
1664 
1665 static DecodeStatus DecodeCopMemInstruction(MCInst &Inst, unsigned Insn,
1666                                   uint64_t Address, const void *Decoder) {
1667   DecodeStatus S = MCDisassembler::Success;
1668 
1669   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1670   unsigned CRd = fieldFromInstruction(Insn, 12, 4);
1671   unsigned coproc = fieldFromInstruction(Insn, 8, 4);
1672   unsigned imm = fieldFromInstruction(Insn, 0, 8);
1673   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1674   unsigned U = fieldFromInstruction(Insn, 23, 1);
1675   const FeatureBitset &featureBits =
1676     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1677 
1678   switch (Inst.getOpcode()) {
1679     case ARM::LDC_OFFSET:
1680     case ARM::LDC_PRE:
1681     case ARM::LDC_POST:
1682     case ARM::LDC_OPTION:
1683     case ARM::LDCL_OFFSET:
1684     case ARM::LDCL_PRE:
1685     case ARM::LDCL_POST:
1686     case ARM::LDCL_OPTION:
1687     case ARM::STC_OFFSET:
1688     case ARM::STC_PRE:
1689     case ARM::STC_POST:
1690     case ARM::STC_OPTION:
1691     case ARM::STCL_OFFSET:
1692     case ARM::STCL_PRE:
1693     case ARM::STCL_POST:
1694     case ARM::STCL_OPTION:
1695     case ARM::t2LDC_OFFSET:
1696     case ARM::t2LDC_PRE:
1697     case ARM::t2LDC_POST:
1698     case ARM::t2LDC_OPTION:
1699     case ARM::t2LDCL_OFFSET:
1700     case ARM::t2LDCL_PRE:
1701     case ARM::t2LDCL_POST:
1702     case ARM::t2LDCL_OPTION:
1703     case ARM::t2STC_OFFSET:
1704     case ARM::t2STC_PRE:
1705     case ARM::t2STC_POST:
1706     case ARM::t2STC_OPTION:
1707     case ARM::t2STCL_OFFSET:
1708     case ARM::t2STCL_PRE:
1709     case ARM::t2STCL_POST:
1710     case ARM::t2STCL_OPTION:
1711     case ARM::t2LDC2_OFFSET:
1712     case ARM::t2LDC2L_OFFSET:
1713     case ARM::t2LDC2_PRE:
1714     case ARM::t2LDC2L_PRE:
1715     case ARM::t2STC2_OFFSET:
1716     case ARM::t2STC2L_OFFSET:
1717     case ARM::t2STC2_PRE:
1718     case ARM::t2STC2L_PRE:
1719     case ARM::LDC2_OFFSET:
1720     case ARM::LDC2L_OFFSET:
1721     case ARM::LDC2_PRE:
1722     case ARM::LDC2L_PRE:
1723     case ARM::STC2_OFFSET:
1724     case ARM::STC2L_OFFSET:
1725     case ARM::STC2_PRE:
1726     case ARM::STC2L_PRE:
1727     case ARM::t2LDC2_OPTION:
1728     case ARM::t2STC2_OPTION:
1729     case ARM::t2LDC2_POST:
1730     case ARM::t2LDC2L_POST:
1731     case ARM::t2STC2_POST:
1732     case ARM::t2STC2L_POST:
1733     case ARM::LDC2_POST:
1734     case ARM::LDC2L_POST:
1735     case ARM::STC2_POST:
1736     case ARM::STC2L_POST:
1737       if (coproc == 0xA || coproc == 0xB ||
1738           (featureBits[ARM::HasV8_1MMainlineOps] &&
1739            (coproc == 0x8 || coproc == 0x9 || coproc == 0xA || coproc == 0xB ||
1740             coproc == 0xE || coproc == 0xF)))
1741         return MCDisassembler::Fail;
1742       break;
1743     default:
1744       break;
1745   }
1746 
1747   if (featureBits[ARM::HasV8Ops] && (coproc != 14))
1748     return MCDisassembler::Fail;
1749 
1750   Inst.addOperand(MCOperand::createImm(coproc));
1751   Inst.addOperand(MCOperand::createImm(CRd));
1752   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1753     return MCDisassembler::Fail;
1754 
1755   switch (Inst.getOpcode()) {
1756     case ARM::t2LDC2_OFFSET:
1757     case ARM::t2LDC2L_OFFSET:
1758     case ARM::t2LDC2_PRE:
1759     case ARM::t2LDC2L_PRE:
1760     case ARM::t2STC2_OFFSET:
1761     case ARM::t2STC2L_OFFSET:
1762     case ARM::t2STC2_PRE:
1763     case ARM::t2STC2L_PRE:
1764     case ARM::LDC2_OFFSET:
1765     case ARM::LDC2L_OFFSET:
1766     case ARM::LDC2_PRE:
1767     case ARM::LDC2L_PRE:
1768     case ARM::STC2_OFFSET:
1769     case ARM::STC2L_OFFSET:
1770     case ARM::STC2_PRE:
1771     case ARM::STC2L_PRE:
1772     case ARM::t2LDC_OFFSET:
1773     case ARM::t2LDCL_OFFSET:
1774     case ARM::t2LDC_PRE:
1775     case ARM::t2LDCL_PRE:
1776     case ARM::t2STC_OFFSET:
1777     case ARM::t2STCL_OFFSET:
1778     case ARM::t2STC_PRE:
1779     case ARM::t2STCL_PRE:
1780     case ARM::LDC_OFFSET:
1781     case ARM::LDCL_OFFSET:
1782     case ARM::LDC_PRE:
1783     case ARM::LDCL_PRE:
1784     case ARM::STC_OFFSET:
1785     case ARM::STCL_OFFSET:
1786     case ARM::STC_PRE:
1787     case ARM::STCL_PRE:
1788       imm = ARM_AM::getAM5Opc(U ? ARM_AM::add : ARM_AM::sub, imm);
1789       Inst.addOperand(MCOperand::createImm(imm));
1790       break;
1791     case ARM::t2LDC2_POST:
1792     case ARM::t2LDC2L_POST:
1793     case ARM::t2STC2_POST:
1794     case ARM::t2STC2L_POST:
1795     case ARM::LDC2_POST:
1796     case ARM::LDC2L_POST:
1797     case ARM::STC2_POST:
1798     case ARM::STC2L_POST:
1799     case ARM::t2LDC_POST:
1800     case ARM::t2LDCL_POST:
1801     case ARM::t2STC_POST:
1802     case ARM::t2STCL_POST:
1803     case ARM::LDC_POST:
1804     case ARM::LDCL_POST:
1805     case ARM::STC_POST:
1806     case ARM::STCL_POST:
1807       imm |= U << 8;
1808       LLVM_FALLTHROUGH;
1809     default:
1810       // The 'option' variant doesn't encode 'U' in the immediate since
1811       // the immediate is unsigned [0,255].
1812       Inst.addOperand(MCOperand::createImm(imm));
1813       break;
1814   }
1815 
1816   switch (Inst.getOpcode()) {
1817     case ARM::LDC_OFFSET:
1818     case ARM::LDC_PRE:
1819     case ARM::LDC_POST:
1820     case ARM::LDC_OPTION:
1821     case ARM::LDCL_OFFSET:
1822     case ARM::LDCL_PRE:
1823     case ARM::LDCL_POST:
1824     case ARM::LDCL_OPTION:
1825     case ARM::STC_OFFSET:
1826     case ARM::STC_PRE:
1827     case ARM::STC_POST:
1828     case ARM::STC_OPTION:
1829     case ARM::STCL_OFFSET:
1830     case ARM::STCL_PRE:
1831     case ARM::STCL_POST:
1832     case ARM::STCL_OPTION:
1833       if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1834         return MCDisassembler::Fail;
1835       break;
1836     default:
1837       break;
1838   }
1839 
1840   return S;
1841 }
1842 
1843 static DecodeStatus
1844 DecodeAddrMode2IdxInstruction(MCInst &Inst, unsigned Insn,
1845                               uint64_t Address, const void *Decoder) {
1846   DecodeStatus S = MCDisassembler::Success;
1847 
1848   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1849   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
1850   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
1851   unsigned imm = fieldFromInstruction(Insn, 0, 12);
1852   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1853   unsigned reg = fieldFromInstruction(Insn, 25, 1);
1854   unsigned P = fieldFromInstruction(Insn, 24, 1);
1855   unsigned W = fieldFromInstruction(Insn, 21, 1);
1856 
1857   // On stores, the writeback operand precedes Rt.
1858   switch (Inst.getOpcode()) {
1859     case ARM::STR_POST_IMM:
1860     case ARM::STR_POST_REG:
1861     case ARM::STRB_POST_IMM:
1862     case ARM::STRB_POST_REG:
1863     case ARM::STRT_POST_REG:
1864     case ARM::STRT_POST_IMM:
1865     case ARM::STRBT_POST_REG:
1866     case ARM::STRBT_POST_IMM:
1867       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1868         return MCDisassembler::Fail;
1869       break;
1870     default:
1871       break;
1872   }
1873 
1874   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
1875     return MCDisassembler::Fail;
1876 
1877   // On loads, the writeback operand comes after Rt.
1878   switch (Inst.getOpcode()) {
1879     case ARM::LDR_POST_IMM:
1880     case ARM::LDR_POST_REG:
1881     case ARM::LDRB_POST_IMM:
1882     case ARM::LDRB_POST_REG:
1883     case ARM::LDRBT_POST_REG:
1884     case ARM::LDRBT_POST_IMM:
1885     case ARM::LDRT_POST_REG:
1886     case ARM::LDRT_POST_IMM:
1887       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1888         return MCDisassembler::Fail;
1889       break;
1890     default:
1891       break;
1892   }
1893 
1894   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1895     return MCDisassembler::Fail;
1896 
1897   ARM_AM::AddrOpc Op = ARM_AM::add;
1898   if (!fieldFromInstruction(Insn, 23, 1))
1899     Op = ARM_AM::sub;
1900 
1901   bool writeback = (P == 0) || (W == 1);
1902   unsigned idx_mode = 0;
1903   if (P && writeback)
1904     idx_mode = ARMII::IndexModePre;
1905   else if (!P && writeback)
1906     idx_mode = ARMII::IndexModePost;
1907 
1908   if (writeback && (Rn == 15 || Rn == Rt))
1909     S = MCDisassembler::SoftFail; // UNPREDICTABLE
1910 
1911   if (reg) {
1912     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1913       return MCDisassembler::Fail;
1914     ARM_AM::ShiftOpc Opc = ARM_AM::lsl;
1915     switch( fieldFromInstruction(Insn, 5, 2)) {
1916       case 0:
1917         Opc = ARM_AM::lsl;
1918         break;
1919       case 1:
1920         Opc = ARM_AM::lsr;
1921         break;
1922       case 2:
1923         Opc = ARM_AM::asr;
1924         break;
1925       case 3:
1926         Opc = ARM_AM::ror;
1927         break;
1928       default:
1929         return MCDisassembler::Fail;
1930     }
1931     unsigned amt = fieldFromInstruction(Insn, 7, 5);
1932     if (Opc == ARM_AM::ror && amt == 0)
1933       Opc = ARM_AM::rrx;
1934     unsigned imm = ARM_AM::getAM2Opc(Op, amt, Opc, idx_mode);
1935 
1936     Inst.addOperand(MCOperand::createImm(imm));
1937   } else {
1938     Inst.addOperand(MCOperand::createReg(0));
1939     unsigned tmp = ARM_AM::getAM2Opc(Op, imm, ARM_AM::lsl, idx_mode);
1940     Inst.addOperand(MCOperand::createImm(tmp));
1941   }
1942 
1943   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1944     return MCDisassembler::Fail;
1945 
1946   return S;
1947 }
1948 
1949 static DecodeStatus DecodeSORegMemOperand(MCInst &Inst, unsigned Val,
1950                                   uint64_t Address, const void *Decoder) {
1951   DecodeStatus S = MCDisassembler::Success;
1952 
1953   unsigned Rn = fieldFromInstruction(Val, 13, 4);
1954   unsigned Rm = fieldFromInstruction(Val,  0, 4);
1955   unsigned type = fieldFromInstruction(Val, 5, 2);
1956   unsigned imm = fieldFromInstruction(Val, 7, 5);
1957   unsigned U = fieldFromInstruction(Val, 12, 1);
1958 
1959   ARM_AM::ShiftOpc ShOp = ARM_AM::lsl;
1960   switch (type) {
1961     case 0:
1962       ShOp = ARM_AM::lsl;
1963       break;
1964     case 1:
1965       ShOp = ARM_AM::lsr;
1966       break;
1967     case 2:
1968       ShOp = ARM_AM::asr;
1969       break;
1970     case 3:
1971       ShOp = ARM_AM::ror;
1972       break;
1973   }
1974 
1975   if (ShOp == ARM_AM::ror && imm == 0)
1976     ShOp = ARM_AM::rrx;
1977 
1978   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1979     return MCDisassembler::Fail;
1980   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1981     return MCDisassembler::Fail;
1982   unsigned shift;
1983   if (U)
1984     shift = ARM_AM::getAM2Opc(ARM_AM::add, imm, ShOp);
1985   else
1986     shift = ARM_AM::getAM2Opc(ARM_AM::sub, imm, ShOp);
1987   Inst.addOperand(MCOperand::createImm(shift));
1988 
1989   return S;
1990 }
1991 
1992 static DecodeStatus
1993 DecodeAddrMode3Instruction(MCInst &Inst, unsigned Insn,
1994                            uint64_t Address, const void *Decoder) {
1995   DecodeStatus S = MCDisassembler::Success;
1996 
1997   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
1998   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1999   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2000   unsigned type = fieldFromInstruction(Insn, 22, 1);
2001   unsigned imm = fieldFromInstruction(Insn, 8, 4);
2002   unsigned U = ((~fieldFromInstruction(Insn, 23, 1)) & 1) << 8;
2003   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2004   unsigned W = fieldFromInstruction(Insn, 21, 1);
2005   unsigned P = fieldFromInstruction(Insn, 24, 1);
2006   unsigned Rt2 = Rt + 1;
2007 
2008   bool writeback = (W == 1) | (P == 0);
2009 
2010   // For {LD,ST}RD, Rt must be even, else undefined.
2011   switch (Inst.getOpcode()) {
2012     case ARM::STRD:
2013     case ARM::STRD_PRE:
2014     case ARM::STRD_POST:
2015     case ARM::LDRD:
2016     case ARM::LDRD_PRE:
2017     case ARM::LDRD_POST:
2018       if (Rt & 0x1) S = MCDisassembler::SoftFail;
2019       break;
2020     default:
2021       break;
2022   }
2023   switch (Inst.getOpcode()) {
2024     case ARM::STRD:
2025     case ARM::STRD_PRE:
2026     case ARM::STRD_POST:
2027       if (P == 0 && W == 1)
2028         S = MCDisassembler::SoftFail;
2029 
2030       if (writeback && (Rn == 15 || Rn == Rt || Rn == Rt2))
2031         S = MCDisassembler::SoftFail;
2032       if (type && Rm == 15)
2033         S = MCDisassembler::SoftFail;
2034       if (Rt2 == 15)
2035         S = MCDisassembler::SoftFail;
2036       if (!type && fieldFromInstruction(Insn, 8, 4))
2037         S = MCDisassembler::SoftFail;
2038       break;
2039     case ARM::STRH:
2040     case ARM::STRH_PRE:
2041     case ARM::STRH_POST:
2042       if (Rt == 15)
2043         S = MCDisassembler::SoftFail;
2044       if (writeback && (Rn == 15 || Rn == Rt))
2045         S = MCDisassembler::SoftFail;
2046       if (!type && Rm == 15)
2047         S = MCDisassembler::SoftFail;
2048       break;
2049     case ARM::LDRD:
2050     case ARM::LDRD_PRE:
2051     case ARM::LDRD_POST:
2052       if (type && Rn == 15) {
2053         if (Rt2 == 15)
2054           S = MCDisassembler::SoftFail;
2055         break;
2056       }
2057       if (P == 0 && W == 1)
2058         S = MCDisassembler::SoftFail;
2059       if (!type && (Rt2 == 15 || Rm == 15 || Rm == Rt || Rm == Rt2))
2060         S = MCDisassembler::SoftFail;
2061       if (!type && writeback && Rn == 15)
2062         S = MCDisassembler::SoftFail;
2063       if (writeback && (Rn == Rt || Rn == Rt2))
2064         S = MCDisassembler::SoftFail;
2065       break;
2066     case ARM::LDRH:
2067     case ARM::LDRH_PRE:
2068     case ARM::LDRH_POST:
2069       if (type && Rn == 15) {
2070         if (Rt == 15)
2071           S = MCDisassembler::SoftFail;
2072         break;
2073       }
2074       if (Rt == 15)
2075         S = MCDisassembler::SoftFail;
2076       if (!type && Rm == 15)
2077         S = MCDisassembler::SoftFail;
2078       if (!type && writeback && (Rn == 15 || Rn == Rt))
2079         S = MCDisassembler::SoftFail;
2080       break;
2081     case ARM::LDRSH:
2082     case ARM::LDRSH_PRE:
2083     case ARM::LDRSH_POST:
2084     case ARM::LDRSB:
2085     case ARM::LDRSB_PRE:
2086     case ARM::LDRSB_POST:
2087       if (type && Rn == 15) {
2088         if (Rt == 15)
2089           S = MCDisassembler::SoftFail;
2090         break;
2091       }
2092       if (type && (Rt == 15 || (writeback && Rn == Rt)))
2093         S = MCDisassembler::SoftFail;
2094       if (!type && (Rt == 15 || Rm == 15))
2095         S = MCDisassembler::SoftFail;
2096       if (!type && writeback && (Rn == 15 || Rn == Rt))
2097         S = MCDisassembler::SoftFail;
2098       break;
2099     default:
2100       break;
2101   }
2102 
2103   if (writeback) { // Writeback
2104     if (P)
2105       U |= ARMII::IndexModePre << 9;
2106     else
2107       U |= ARMII::IndexModePost << 9;
2108 
2109     // On stores, the writeback operand precedes Rt.
2110     switch (Inst.getOpcode()) {
2111     case ARM::STRD:
2112     case ARM::STRD_PRE:
2113     case ARM::STRD_POST:
2114     case ARM::STRH:
2115     case ARM::STRH_PRE:
2116     case ARM::STRH_POST:
2117       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2118         return MCDisassembler::Fail;
2119       break;
2120     default:
2121       break;
2122     }
2123   }
2124 
2125   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
2126     return MCDisassembler::Fail;
2127   switch (Inst.getOpcode()) {
2128     case ARM::STRD:
2129     case ARM::STRD_PRE:
2130     case ARM::STRD_POST:
2131     case ARM::LDRD:
2132     case ARM::LDRD_PRE:
2133     case ARM::LDRD_POST:
2134       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder)))
2135         return MCDisassembler::Fail;
2136       break;
2137     default:
2138       break;
2139   }
2140 
2141   if (writeback) {
2142     // On loads, the writeback operand comes after Rt.
2143     switch (Inst.getOpcode()) {
2144     case ARM::LDRD:
2145     case ARM::LDRD_PRE:
2146     case ARM::LDRD_POST:
2147     case ARM::LDRH:
2148     case ARM::LDRH_PRE:
2149     case ARM::LDRH_POST:
2150     case ARM::LDRSH:
2151     case ARM::LDRSH_PRE:
2152     case ARM::LDRSH_POST:
2153     case ARM::LDRSB:
2154     case ARM::LDRSB_PRE:
2155     case ARM::LDRSB_POST:
2156     case ARM::LDRHTr:
2157     case ARM::LDRSBTr:
2158       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2159         return MCDisassembler::Fail;
2160       break;
2161     default:
2162       break;
2163     }
2164   }
2165 
2166   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2167     return MCDisassembler::Fail;
2168 
2169   if (type) {
2170     Inst.addOperand(MCOperand::createReg(0));
2171     Inst.addOperand(MCOperand::createImm(U | (imm << 4) | Rm));
2172   } else {
2173     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2174     return MCDisassembler::Fail;
2175     Inst.addOperand(MCOperand::createImm(U));
2176   }
2177 
2178   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2179     return MCDisassembler::Fail;
2180 
2181   return S;
2182 }
2183 
2184 static DecodeStatus DecodeRFEInstruction(MCInst &Inst, unsigned Insn,
2185                                  uint64_t Address, const void *Decoder) {
2186   DecodeStatus S = MCDisassembler::Success;
2187 
2188   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2189   unsigned mode = fieldFromInstruction(Insn, 23, 2);
2190 
2191   switch (mode) {
2192     case 0:
2193       mode = ARM_AM::da;
2194       break;
2195     case 1:
2196       mode = ARM_AM::ia;
2197       break;
2198     case 2:
2199       mode = ARM_AM::db;
2200       break;
2201     case 3:
2202       mode = ARM_AM::ib;
2203       break;
2204   }
2205 
2206   Inst.addOperand(MCOperand::createImm(mode));
2207   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2208     return MCDisassembler::Fail;
2209 
2210   return S;
2211 }
2212 
2213 static DecodeStatus DecodeQADDInstruction(MCInst &Inst, unsigned Insn,
2214                                uint64_t Address, const void *Decoder) {
2215   DecodeStatus S = MCDisassembler::Success;
2216 
2217   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2218   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2219   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2220   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2221 
2222   if (pred == 0xF)
2223     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
2224 
2225   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2226     return MCDisassembler::Fail;
2227   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
2228     return MCDisassembler::Fail;
2229   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
2230     return MCDisassembler::Fail;
2231   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2232     return MCDisassembler::Fail;
2233   return S;
2234 }
2235 
2236 static DecodeStatus DecodeMemMultipleWritebackInstruction(MCInst &Inst,
2237                                   unsigned Insn,
2238                                   uint64_t Address, const void *Decoder) {
2239   DecodeStatus S = MCDisassembler::Success;
2240 
2241   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2242   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2243   unsigned reglist = fieldFromInstruction(Insn, 0, 16);
2244 
2245   if (pred == 0xF) {
2246     // Ambiguous with RFE and SRS
2247     switch (Inst.getOpcode()) {
2248       case ARM::LDMDA:
2249         Inst.setOpcode(ARM::RFEDA);
2250         break;
2251       case ARM::LDMDA_UPD:
2252         Inst.setOpcode(ARM::RFEDA_UPD);
2253         break;
2254       case ARM::LDMDB:
2255         Inst.setOpcode(ARM::RFEDB);
2256         break;
2257       case ARM::LDMDB_UPD:
2258         Inst.setOpcode(ARM::RFEDB_UPD);
2259         break;
2260       case ARM::LDMIA:
2261         Inst.setOpcode(ARM::RFEIA);
2262         break;
2263       case ARM::LDMIA_UPD:
2264         Inst.setOpcode(ARM::RFEIA_UPD);
2265         break;
2266       case ARM::LDMIB:
2267         Inst.setOpcode(ARM::RFEIB);
2268         break;
2269       case ARM::LDMIB_UPD:
2270         Inst.setOpcode(ARM::RFEIB_UPD);
2271         break;
2272       case ARM::STMDA:
2273         Inst.setOpcode(ARM::SRSDA);
2274         break;
2275       case ARM::STMDA_UPD:
2276         Inst.setOpcode(ARM::SRSDA_UPD);
2277         break;
2278       case ARM::STMDB:
2279         Inst.setOpcode(ARM::SRSDB);
2280         break;
2281       case ARM::STMDB_UPD:
2282         Inst.setOpcode(ARM::SRSDB_UPD);
2283         break;
2284       case ARM::STMIA:
2285         Inst.setOpcode(ARM::SRSIA);
2286         break;
2287       case ARM::STMIA_UPD:
2288         Inst.setOpcode(ARM::SRSIA_UPD);
2289         break;
2290       case ARM::STMIB:
2291         Inst.setOpcode(ARM::SRSIB);
2292         break;
2293       case ARM::STMIB_UPD:
2294         Inst.setOpcode(ARM::SRSIB_UPD);
2295         break;
2296       default:
2297         return MCDisassembler::Fail;
2298     }
2299 
2300     // For stores (which become SRS's, the only operand is the mode.
2301     if (fieldFromInstruction(Insn, 20, 1) == 0) {
2302       // Check SRS encoding constraints
2303       if (!(fieldFromInstruction(Insn, 22, 1) == 1 &&
2304             fieldFromInstruction(Insn, 20, 1) == 0))
2305         return MCDisassembler::Fail;
2306 
2307       Inst.addOperand(
2308           MCOperand::createImm(fieldFromInstruction(Insn, 0, 4)));
2309       return S;
2310     }
2311 
2312     return DecodeRFEInstruction(Inst, Insn, Address, Decoder);
2313   }
2314 
2315   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2316     return MCDisassembler::Fail;
2317   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2318     return MCDisassembler::Fail; // Tied
2319   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2320     return MCDisassembler::Fail;
2321   if (!Check(S, DecodeRegListOperand(Inst, reglist, Address, Decoder)))
2322     return MCDisassembler::Fail;
2323 
2324   return S;
2325 }
2326 
2327 // Check for UNPREDICTABLE predicated ESB instruction
2328 static DecodeStatus DecodeHINTInstruction(MCInst &Inst, unsigned Insn,
2329                                  uint64_t Address, const void *Decoder) {
2330   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2331   unsigned imm8 = fieldFromInstruction(Insn, 0, 8);
2332   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
2333   const FeatureBitset &FeatureBits = Dis->getSubtargetInfo().getFeatureBits();
2334 
2335   DecodeStatus S = MCDisassembler::Success;
2336 
2337   Inst.addOperand(MCOperand::createImm(imm8));
2338 
2339   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2340     return MCDisassembler::Fail;
2341 
2342   // ESB is unpredictable if pred != AL. Without the RAS extension, it is a NOP,
2343   // so all predicates should be allowed.
2344   if (imm8 == 0x10 && pred != 0xe && ((FeatureBits[ARM::FeatureRAS]) != 0))
2345     S = MCDisassembler::SoftFail;
2346 
2347   return S;
2348 }
2349 
2350 static DecodeStatus DecodeCPSInstruction(MCInst &Inst, unsigned Insn,
2351                                  uint64_t Address, const void *Decoder) {
2352   unsigned imod = fieldFromInstruction(Insn, 18, 2);
2353   unsigned M = fieldFromInstruction(Insn, 17, 1);
2354   unsigned iflags = fieldFromInstruction(Insn, 6, 3);
2355   unsigned mode = fieldFromInstruction(Insn, 0, 5);
2356 
2357   DecodeStatus S = MCDisassembler::Success;
2358 
2359   // This decoder is called from multiple location that do not check
2360   // the full encoding is valid before they do.
2361   if (fieldFromInstruction(Insn, 5, 1) != 0 ||
2362       fieldFromInstruction(Insn, 16, 1) != 0 ||
2363       fieldFromInstruction(Insn, 20, 8) != 0x10)
2364     return MCDisassembler::Fail;
2365 
2366   // imod == '01' --> UNPREDICTABLE
2367   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
2368   // return failure here.  The '01' imod value is unprintable, so there's
2369   // nothing useful we could do even if we returned UNPREDICTABLE.
2370 
2371   if (imod == 1) return MCDisassembler::Fail;
2372 
2373   if (imod && M) {
2374     Inst.setOpcode(ARM::CPS3p);
2375     Inst.addOperand(MCOperand::createImm(imod));
2376     Inst.addOperand(MCOperand::createImm(iflags));
2377     Inst.addOperand(MCOperand::createImm(mode));
2378   } else if (imod && !M) {
2379     Inst.setOpcode(ARM::CPS2p);
2380     Inst.addOperand(MCOperand::createImm(imod));
2381     Inst.addOperand(MCOperand::createImm(iflags));
2382     if (mode) S = MCDisassembler::SoftFail;
2383   } else if (!imod && M) {
2384     Inst.setOpcode(ARM::CPS1p);
2385     Inst.addOperand(MCOperand::createImm(mode));
2386     if (iflags) S = MCDisassembler::SoftFail;
2387   } else {
2388     // imod == '00' && M == '0' --> UNPREDICTABLE
2389     Inst.setOpcode(ARM::CPS1p);
2390     Inst.addOperand(MCOperand::createImm(mode));
2391     S = MCDisassembler::SoftFail;
2392   }
2393 
2394   return S;
2395 }
2396 
2397 static DecodeStatus DecodeT2CPSInstruction(MCInst &Inst, unsigned Insn,
2398                                  uint64_t Address, const void *Decoder) {
2399   unsigned imod = fieldFromInstruction(Insn, 9, 2);
2400   unsigned M = fieldFromInstruction(Insn, 8, 1);
2401   unsigned iflags = fieldFromInstruction(Insn, 5, 3);
2402   unsigned mode = fieldFromInstruction(Insn, 0, 5);
2403 
2404   DecodeStatus S = MCDisassembler::Success;
2405 
2406   // imod == '01' --> UNPREDICTABLE
2407   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
2408   // return failure here.  The '01' imod value is unprintable, so there's
2409   // nothing useful we could do even if we returned UNPREDICTABLE.
2410 
2411   if (imod == 1) return MCDisassembler::Fail;
2412 
2413   if (imod && M) {
2414     Inst.setOpcode(ARM::t2CPS3p);
2415     Inst.addOperand(MCOperand::createImm(imod));
2416     Inst.addOperand(MCOperand::createImm(iflags));
2417     Inst.addOperand(MCOperand::createImm(mode));
2418   } else if (imod && !M) {
2419     Inst.setOpcode(ARM::t2CPS2p);
2420     Inst.addOperand(MCOperand::createImm(imod));
2421     Inst.addOperand(MCOperand::createImm(iflags));
2422     if (mode) S = MCDisassembler::SoftFail;
2423   } else if (!imod && M) {
2424     Inst.setOpcode(ARM::t2CPS1p);
2425     Inst.addOperand(MCOperand::createImm(mode));
2426     if (iflags) S = MCDisassembler::SoftFail;
2427   } else {
2428     // imod == '00' && M == '0' --> this is a HINT instruction
2429     int imm = fieldFromInstruction(Insn, 0, 8);
2430     // HINT are defined only for immediate in [0..4]
2431     if(imm > 4) return MCDisassembler::Fail;
2432     Inst.setOpcode(ARM::t2HINT);
2433     Inst.addOperand(MCOperand::createImm(imm));
2434   }
2435 
2436   return S;
2437 }
2438 
2439 static DecodeStatus DecodeT2MOVTWInstruction(MCInst &Inst, unsigned Insn,
2440                                  uint64_t Address, const void *Decoder) {
2441   DecodeStatus S = MCDisassembler::Success;
2442 
2443   unsigned Rd = fieldFromInstruction(Insn, 8, 4);
2444   unsigned imm = 0;
2445 
2446   imm |= (fieldFromInstruction(Insn, 0, 8) << 0);
2447   imm |= (fieldFromInstruction(Insn, 12, 3) << 8);
2448   imm |= (fieldFromInstruction(Insn, 16, 4) << 12);
2449   imm |= (fieldFromInstruction(Insn, 26, 1) << 11);
2450 
2451   if (Inst.getOpcode() == ARM::t2MOVTi16)
2452     if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
2453       return MCDisassembler::Fail;
2454   if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
2455     return MCDisassembler::Fail;
2456 
2457   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
2458     Inst.addOperand(MCOperand::createImm(imm));
2459 
2460   return S;
2461 }
2462 
2463 static DecodeStatus DecodeArmMOVTWInstruction(MCInst &Inst, unsigned Insn,
2464                                  uint64_t Address, const void *Decoder) {
2465   DecodeStatus S = MCDisassembler::Success;
2466 
2467   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2468   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2469   unsigned imm = 0;
2470 
2471   imm |= (fieldFromInstruction(Insn, 0, 12) << 0);
2472   imm |= (fieldFromInstruction(Insn, 16, 4) << 12);
2473 
2474   if (Inst.getOpcode() == ARM::MOVTi16)
2475     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2476       return MCDisassembler::Fail;
2477 
2478   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2479     return MCDisassembler::Fail;
2480 
2481   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
2482     Inst.addOperand(MCOperand::createImm(imm));
2483 
2484   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2485     return MCDisassembler::Fail;
2486 
2487   return S;
2488 }
2489 
2490 static DecodeStatus DecodeSMLAInstruction(MCInst &Inst, unsigned Insn,
2491                                  uint64_t Address, const void *Decoder) {
2492   DecodeStatus S = MCDisassembler::Success;
2493 
2494   unsigned Rd = fieldFromInstruction(Insn, 16, 4);
2495   unsigned Rn = fieldFromInstruction(Insn, 0, 4);
2496   unsigned Rm = fieldFromInstruction(Insn, 8, 4);
2497   unsigned Ra = fieldFromInstruction(Insn, 12, 4);
2498   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2499 
2500   if (pred == 0xF)
2501     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
2502 
2503   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2504     return MCDisassembler::Fail;
2505   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
2506     return MCDisassembler::Fail;
2507   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
2508     return MCDisassembler::Fail;
2509   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Ra, Address, Decoder)))
2510     return MCDisassembler::Fail;
2511 
2512   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2513     return MCDisassembler::Fail;
2514 
2515   return S;
2516 }
2517 
2518 static DecodeStatus DecodeTSTInstruction(MCInst &Inst, unsigned Insn,
2519                                   uint64_t Address, const void *Decoder) {
2520   DecodeStatus S = MCDisassembler::Success;
2521 
2522   unsigned Pred = fieldFromInstruction(Insn, 28, 4);
2523   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2524   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2525 
2526   if (Pred == 0xF)
2527     return DecodeSETPANInstruction(Inst, Insn, Address, Decoder);
2528 
2529   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2530     return MCDisassembler::Fail;
2531   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2532     return MCDisassembler::Fail;
2533   if (!Check(S, DecodePredicateOperand(Inst, Pred, Address, Decoder)))
2534     return MCDisassembler::Fail;
2535 
2536   return S;
2537 }
2538 
2539 static DecodeStatus DecodeSETPANInstruction(MCInst &Inst, unsigned Insn,
2540                                   uint64_t Address, const void *Decoder) {
2541   DecodeStatus S = MCDisassembler::Success;
2542 
2543   unsigned Imm = fieldFromInstruction(Insn, 9, 1);
2544 
2545   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
2546   const FeatureBitset &FeatureBits = Dis->getSubtargetInfo().getFeatureBits();
2547 
2548   if (!FeatureBits[ARM::HasV8_1aOps] ||
2549       !FeatureBits[ARM::HasV8Ops])
2550     return MCDisassembler::Fail;
2551 
2552   // Decoder can be called from DecodeTST, which does not check the full
2553   // encoding is valid.
2554   if (fieldFromInstruction(Insn, 20,12) != 0xf11 ||
2555       fieldFromInstruction(Insn, 4,4) != 0)
2556     return MCDisassembler::Fail;
2557   if (fieldFromInstruction(Insn, 10,10) != 0 ||
2558       fieldFromInstruction(Insn, 0,4) != 0)
2559     S = MCDisassembler::SoftFail;
2560 
2561   Inst.setOpcode(ARM::SETPAN);
2562   Inst.addOperand(MCOperand::createImm(Imm));
2563 
2564   return S;
2565 }
2566 
2567 static DecodeStatus DecodeAddrModeImm12Operand(MCInst &Inst, unsigned Val,
2568                            uint64_t Address, const void *Decoder) {
2569   DecodeStatus S = MCDisassembler::Success;
2570 
2571   unsigned add = fieldFromInstruction(Val, 12, 1);
2572   unsigned imm = fieldFromInstruction(Val, 0, 12);
2573   unsigned Rn = fieldFromInstruction(Val, 13, 4);
2574 
2575   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2576     return MCDisassembler::Fail;
2577 
2578   if (!add) imm *= -1;
2579   if (imm == 0 && !add) imm = INT32_MIN;
2580   Inst.addOperand(MCOperand::createImm(imm));
2581   if (Rn == 15)
2582     tryAddingPcLoadReferenceComment(Address, Address + imm + 8, Decoder);
2583 
2584   return S;
2585 }
2586 
2587 static DecodeStatus DecodeAddrMode5Operand(MCInst &Inst, unsigned Val,
2588                                    uint64_t Address, const void *Decoder) {
2589   DecodeStatus S = MCDisassembler::Success;
2590 
2591   unsigned Rn = fieldFromInstruction(Val, 9, 4);
2592   // U == 1 to add imm, 0 to subtract it.
2593   unsigned U = fieldFromInstruction(Val, 8, 1);
2594   unsigned imm = fieldFromInstruction(Val, 0, 8);
2595 
2596   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2597     return MCDisassembler::Fail;
2598 
2599   if (U)
2600     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5Opc(ARM_AM::add, imm)));
2601   else
2602     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5Opc(ARM_AM::sub, imm)));
2603 
2604   return S;
2605 }
2606 
2607 static DecodeStatus DecodeAddrMode5FP16Operand(MCInst &Inst, unsigned Val,
2608                                    uint64_t Address, const void *Decoder) {
2609   DecodeStatus S = MCDisassembler::Success;
2610 
2611   unsigned Rn = fieldFromInstruction(Val, 9, 4);
2612   // U == 1 to add imm, 0 to subtract it.
2613   unsigned U = fieldFromInstruction(Val, 8, 1);
2614   unsigned imm = fieldFromInstruction(Val, 0, 8);
2615 
2616   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2617     return MCDisassembler::Fail;
2618 
2619   if (U)
2620     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5FP16Opc(ARM_AM::add, imm)));
2621   else
2622     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5FP16Opc(ARM_AM::sub, imm)));
2623 
2624   return S;
2625 }
2626 
2627 static DecodeStatus DecodeAddrMode7Operand(MCInst &Inst, unsigned Val,
2628                                    uint64_t Address, const void *Decoder) {
2629   return DecodeGPRRegisterClass(Inst, Val, Address, Decoder);
2630 }
2631 
2632 static DecodeStatus
2633 DecodeT2BInstruction(MCInst &Inst, unsigned Insn,
2634                      uint64_t Address, const void *Decoder) {
2635   DecodeStatus Status = MCDisassembler::Success;
2636 
2637   // Note the J1 and J2 values are from the encoded instruction.  So here
2638   // change them to I1 and I2 values via as documented:
2639   // I1 = NOT(J1 EOR S);
2640   // I2 = NOT(J2 EOR S);
2641   // and build the imm32 with one trailing zero as documented:
2642   // imm32 = SignExtend(S:I1:I2:imm10:imm11:'0', 32);
2643   unsigned S = fieldFromInstruction(Insn, 26, 1);
2644   unsigned J1 = fieldFromInstruction(Insn, 13, 1);
2645   unsigned J2 = fieldFromInstruction(Insn, 11, 1);
2646   unsigned I1 = !(J1 ^ S);
2647   unsigned I2 = !(J2 ^ S);
2648   unsigned imm10 = fieldFromInstruction(Insn, 16, 10);
2649   unsigned imm11 = fieldFromInstruction(Insn, 0, 11);
2650   unsigned tmp = (S << 23) | (I1 << 22) | (I2 << 21) | (imm10 << 11) | imm11;
2651   int imm32 = SignExtend32<25>(tmp << 1);
2652   if (!tryAddingSymbolicOperand(Address, Address + imm32 + 4,
2653                                 true, 4, Inst, Decoder))
2654     Inst.addOperand(MCOperand::createImm(imm32));
2655 
2656   return Status;
2657 }
2658 
2659 static DecodeStatus
2660 DecodeBranchImmInstruction(MCInst &Inst, unsigned Insn,
2661                            uint64_t Address, const void *Decoder) {
2662   DecodeStatus S = MCDisassembler::Success;
2663 
2664   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2665   unsigned imm = fieldFromInstruction(Insn, 0, 24) << 2;
2666 
2667   if (pred == 0xF) {
2668     Inst.setOpcode(ARM::BLXi);
2669     imm |= fieldFromInstruction(Insn, 24, 1) << 1;
2670     if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<26>(imm) + 8,
2671                                   true, 4, Inst, Decoder))
2672     Inst.addOperand(MCOperand::createImm(SignExtend32<26>(imm)));
2673     return S;
2674   }
2675 
2676   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<26>(imm) + 8,
2677                                 true, 4, Inst, Decoder))
2678     Inst.addOperand(MCOperand::createImm(SignExtend32<26>(imm)));
2679   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2680     return MCDisassembler::Fail;
2681 
2682   return S;
2683 }
2684 
2685 static DecodeStatus DecodeAddrMode6Operand(MCInst &Inst, unsigned Val,
2686                                    uint64_t Address, const void *Decoder) {
2687   DecodeStatus S = MCDisassembler::Success;
2688 
2689   unsigned Rm = fieldFromInstruction(Val, 0, 4);
2690   unsigned align = fieldFromInstruction(Val, 4, 2);
2691 
2692   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2693     return MCDisassembler::Fail;
2694   if (!align)
2695     Inst.addOperand(MCOperand::createImm(0));
2696   else
2697     Inst.addOperand(MCOperand::createImm(4 << align));
2698 
2699   return S;
2700 }
2701 
2702 static DecodeStatus DecodeVLDInstruction(MCInst &Inst, unsigned Insn,
2703                                    uint64_t Address, const void *Decoder) {
2704   DecodeStatus S = MCDisassembler::Success;
2705 
2706   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2707   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
2708   unsigned wb = fieldFromInstruction(Insn, 16, 4);
2709   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2710   Rn |= fieldFromInstruction(Insn, 4, 2) << 4;
2711   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2712 
2713   // First output register
2714   switch (Inst.getOpcode()) {
2715   case ARM::VLD1q16: case ARM::VLD1q32: case ARM::VLD1q64: case ARM::VLD1q8:
2716   case ARM::VLD1q16wb_fixed: case ARM::VLD1q16wb_register:
2717   case ARM::VLD1q32wb_fixed: case ARM::VLD1q32wb_register:
2718   case ARM::VLD1q64wb_fixed: case ARM::VLD1q64wb_register:
2719   case ARM::VLD1q8wb_fixed: case ARM::VLD1q8wb_register:
2720   case ARM::VLD2d16: case ARM::VLD2d32: case ARM::VLD2d8:
2721   case ARM::VLD2d16wb_fixed: case ARM::VLD2d16wb_register:
2722   case ARM::VLD2d32wb_fixed: case ARM::VLD2d32wb_register:
2723   case ARM::VLD2d8wb_fixed: case ARM::VLD2d8wb_register:
2724     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
2725       return MCDisassembler::Fail;
2726     break;
2727   case ARM::VLD2b16:
2728   case ARM::VLD2b32:
2729   case ARM::VLD2b8:
2730   case ARM::VLD2b16wb_fixed:
2731   case ARM::VLD2b16wb_register:
2732   case ARM::VLD2b32wb_fixed:
2733   case ARM::VLD2b32wb_register:
2734   case ARM::VLD2b8wb_fixed:
2735   case ARM::VLD2b8wb_register:
2736     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
2737       return MCDisassembler::Fail;
2738     break;
2739   default:
2740     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2741       return MCDisassembler::Fail;
2742   }
2743 
2744   // Second output register
2745   switch (Inst.getOpcode()) {
2746     case ARM::VLD3d8:
2747     case ARM::VLD3d16:
2748     case ARM::VLD3d32:
2749     case ARM::VLD3d8_UPD:
2750     case ARM::VLD3d16_UPD:
2751     case ARM::VLD3d32_UPD:
2752     case ARM::VLD4d8:
2753     case ARM::VLD4d16:
2754     case ARM::VLD4d32:
2755     case ARM::VLD4d8_UPD:
2756     case ARM::VLD4d16_UPD:
2757     case ARM::VLD4d32_UPD:
2758       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
2759         return MCDisassembler::Fail;
2760       break;
2761     case ARM::VLD3q8:
2762     case ARM::VLD3q16:
2763     case ARM::VLD3q32:
2764     case ARM::VLD3q8_UPD:
2765     case ARM::VLD3q16_UPD:
2766     case ARM::VLD3q32_UPD:
2767     case ARM::VLD4q8:
2768     case ARM::VLD4q16:
2769     case ARM::VLD4q32:
2770     case ARM::VLD4q8_UPD:
2771     case ARM::VLD4q16_UPD:
2772     case ARM::VLD4q32_UPD:
2773       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2774         return MCDisassembler::Fail;
2775       break;
2776     default:
2777       break;
2778   }
2779 
2780   // Third output register
2781   switch(Inst.getOpcode()) {
2782     case ARM::VLD3d8:
2783     case ARM::VLD3d16:
2784     case ARM::VLD3d32:
2785     case ARM::VLD3d8_UPD:
2786     case ARM::VLD3d16_UPD:
2787     case ARM::VLD3d32_UPD:
2788     case ARM::VLD4d8:
2789     case ARM::VLD4d16:
2790     case ARM::VLD4d32:
2791     case ARM::VLD4d8_UPD:
2792     case ARM::VLD4d16_UPD:
2793     case ARM::VLD4d32_UPD:
2794       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2795         return MCDisassembler::Fail;
2796       break;
2797     case ARM::VLD3q8:
2798     case ARM::VLD3q16:
2799     case ARM::VLD3q32:
2800     case ARM::VLD3q8_UPD:
2801     case ARM::VLD3q16_UPD:
2802     case ARM::VLD3q32_UPD:
2803     case ARM::VLD4q8:
2804     case ARM::VLD4q16:
2805     case ARM::VLD4q32:
2806     case ARM::VLD4q8_UPD:
2807     case ARM::VLD4q16_UPD:
2808     case ARM::VLD4q32_UPD:
2809       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
2810         return MCDisassembler::Fail;
2811       break;
2812     default:
2813       break;
2814   }
2815 
2816   // Fourth output register
2817   switch (Inst.getOpcode()) {
2818     case ARM::VLD4d8:
2819     case ARM::VLD4d16:
2820     case ARM::VLD4d32:
2821     case ARM::VLD4d8_UPD:
2822     case ARM::VLD4d16_UPD:
2823     case ARM::VLD4d32_UPD:
2824       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
2825         return MCDisassembler::Fail;
2826       break;
2827     case ARM::VLD4q8:
2828     case ARM::VLD4q16:
2829     case ARM::VLD4q32:
2830     case ARM::VLD4q8_UPD:
2831     case ARM::VLD4q16_UPD:
2832     case ARM::VLD4q32_UPD:
2833       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
2834         return MCDisassembler::Fail;
2835       break;
2836     default:
2837       break;
2838   }
2839 
2840   // Writeback operand
2841   switch (Inst.getOpcode()) {
2842     case ARM::VLD1d8wb_fixed:
2843     case ARM::VLD1d16wb_fixed:
2844     case ARM::VLD1d32wb_fixed:
2845     case ARM::VLD1d64wb_fixed:
2846     case ARM::VLD1d8wb_register:
2847     case ARM::VLD1d16wb_register:
2848     case ARM::VLD1d32wb_register:
2849     case ARM::VLD1d64wb_register:
2850     case ARM::VLD1q8wb_fixed:
2851     case ARM::VLD1q16wb_fixed:
2852     case ARM::VLD1q32wb_fixed:
2853     case ARM::VLD1q64wb_fixed:
2854     case ARM::VLD1q8wb_register:
2855     case ARM::VLD1q16wb_register:
2856     case ARM::VLD1q32wb_register:
2857     case ARM::VLD1q64wb_register:
2858     case ARM::VLD1d8Twb_fixed:
2859     case ARM::VLD1d8Twb_register:
2860     case ARM::VLD1d16Twb_fixed:
2861     case ARM::VLD1d16Twb_register:
2862     case ARM::VLD1d32Twb_fixed:
2863     case ARM::VLD1d32Twb_register:
2864     case ARM::VLD1d64Twb_fixed:
2865     case ARM::VLD1d64Twb_register:
2866     case ARM::VLD1d8Qwb_fixed:
2867     case ARM::VLD1d8Qwb_register:
2868     case ARM::VLD1d16Qwb_fixed:
2869     case ARM::VLD1d16Qwb_register:
2870     case ARM::VLD1d32Qwb_fixed:
2871     case ARM::VLD1d32Qwb_register:
2872     case ARM::VLD1d64Qwb_fixed:
2873     case ARM::VLD1d64Qwb_register:
2874     case ARM::VLD2d8wb_fixed:
2875     case ARM::VLD2d16wb_fixed:
2876     case ARM::VLD2d32wb_fixed:
2877     case ARM::VLD2q8wb_fixed:
2878     case ARM::VLD2q16wb_fixed:
2879     case ARM::VLD2q32wb_fixed:
2880     case ARM::VLD2d8wb_register:
2881     case ARM::VLD2d16wb_register:
2882     case ARM::VLD2d32wb_register:
2883     case ARM::VLD2q8wb_register:
2884     case ARM::VLD2q16wb_register:
2885     case ARM::VLD2q32wb_register:
2886     case ARM::VLD2b8wb_fixed:
2887     case ARM::VLD2b16wb_fixed:
2888     case ARM::VLD2b32wb_fixed:
2889     case ARM::VLD2b8wb_register:
2890     case ARM::VLD2b16wb_register:
2891     case ARM::VLD2b32wb_register:
2892       Inst.addOperand(MCOperand::createImm(0));
2893       break;
2894     case ARM::VLD3d8_UPD:
2895     case ARM::VLD3d16_UPD:
2896     case ARM::VLD3d32_UPD:
2897     case ARM::VLD3q8_UPD:
2898     case ARM::VLD3q16_UPD:
2899     case ARM::VLD3q32_UPD:
2900     case ARM::VLD4d8_UPD:
2901     case ARM::VLD4d16_UPD:
2902     case ARM::VLD4d32_UPD:
2903     case ARM::VLD4q8_UPD:
2904     case ARM::VLD4q16_UPD:
2905     case ARM::VLD4q32_UPD:
2906       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
2907         return MCDisassembler::Fail;
2908       break;
2909     default:
2910       break;
2911   }
2912 
2913   // AddrMode6 Base (register+alignment)
2914   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
2915     return MCDisassembler::Fail;
2916 
2917   // AddrMode6 Offset (register)
2918   switch (Inst.getOpcode()) {
2919   default:
2920     // The below have been updated to have explicit am6offset split
2921     // between fixed and register offset. For those instructions not
2922     // yet updated, we need to add an additional reg0 operand for the
2923     // fixed variant.
2924     //
2925     // The fixed offset encodes as Rm == 0xd, so we check for that.
2926     if (Rm == 0xd) {
2927       Inst.addOperand(MCOperand::createReg(0));
2928       break;
2929     }
2930     // Fall through to handle the register offset variant.
2931     LLVM_FALLTHROUGH;
2932   case ARM::VLD1d8wb_fixed:
2933   case ARM::VLD1d16wb_fixed:
2934   case ARM::VLD1d32wb_fixed:
2935   case ARM::VLD1d64wb_fixed:
2936   case ARM::VLD1d8Twb_fixed:
2937   case ARM::VLD1d16Twb_fixed:
2938   case ARM::VLD1d32Twb_fixed:
2939   case ARM::VLD1d64Twb_fixed:
2940   case ARM::VLD1d8Qwb_fixed:
2941   case ARM::VLD1d16Qwb_fixed:
2942   case ARM::VLD1d32Qwb_fixed:
2943   case ARM::VLD1d64Qwb_fixed:
2944   case ARM::VLD1d8wb_register:
2945   case ARM::VLD1d16wb_register:
2946   case ARM::VLD1d32wb_register:
2947   case ARM::VLD1d64wb_register:
2948   case ARM::VLD1q8wb_fixed:
2949   case ARM::VLD1q16wb_fixed:
2950   case ARM::VLD1q32wb_fixed:
2951   case ARM::VLD1q64wb_fixed:
2952   case ARM::VLD1q8wb_register:
2953   case ARM::VLD1q16wb_register:
2954   case ARM::VLD1q32wb_register:
2955   case ARM::VLD1q64wb_register:
2956     // The fixed offset post-increment encodes Rm == 0xd. The no-writeback
2957     // variant encodes Rm == 0xf. Anything else is a register offset post-
2958     // increment and we need to add the register operand to the instruction.
2959     if (Rm != 0xD && Rm != 0xF &&
2960         !Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2961       return MCDisassembler::Fail;
2962     break;
2963   case ARM::VLD2d8wb_fixed:
2964   case ARM::VLD2d16wb_fixed:
2965   case ARM::VLD2d32wb_fixed:
2966   case ARM::VLD2b8wb_fixed:
2967   case ARM::VLD2b16wb_fixed:
2968   case ARM::VLD2b32wb_fixed:
2969   case ARM::VLD2q8wb_fixed:
2970   case ARM::VLD2q16wb_fixed:
2971   case ARM::VLD2q32wb_fixed:
2972     break;
2973   }
2974 
2975   return S;
2976 }
2977 
2978 static DecodeStatus DecodeVLDST1Instruction(MCInst &Inst, unsigned Insn,
2979                                    uint64_t Address, const void *Decoder) {
2980   unsigned type = fieldFromInstruction(Insn, 8, 4);
2981   unsigned align = fieldFromInstruction(Insn, 4, 2);
2982   if (type == 6 && (align & 2)) return MCDisassembler::Fail;
2983   if (type == 7 && (align & 2)) return MCDisassembler::Fail;
2984   if (type == 10 && align == 3) return MCDisassembler::Fail;
2985 
2986   unsigned load = fieldFromInstruction(Insn, 21, 1);
2987   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2988               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2989 }
2990 
2991 static DecodeStatus DecodeVLDST2Instruction(MCInst &Inst, unsigned Insn,
2992                                    uint64_t Address, const void *Decoder) {
2993   unsigned size = fieldFromInstruction(Insn, 6, 2);
2994   if (size == 3) return MCDisassembler::Fail;
2995 
2996   unsigned type = fieldFromInstruction(Insn, 8, 4);
2997   unsigned align = fieldFromInstruction(Insn, 4, 2);
2998   if (type == 8 && align == 3) return MCDisassembler::Fail;
2999   if (type == 9 && align == 3) return MCDisassembler::Fail;
3000 
3001   unsigned load = fieldFromInstruction(Insn, 21, 1);
3002   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
3003               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
3004 }
3005 
3006 static DecodeStatus DecodeVLDST3Instruction(MCInst &Inst, unsigned Insn,
3007                                    uint64_t Address, const void *Decoder) {
3008   unsigned size = fieldFromInstruction(Insn, 6, 2);
3009   if (size == 3) return MCDisassembler::Fail;
3010 
3011   unsigned align = fieldFromInstruction(Insn, 4, 2);
3012   if (align & 2) return MCDisassembler::Fail;
3013 
3014   unsigned load = fieldFromInstruction(Insn, 21, 1);
3015   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
3016               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
3017 }
3018 
3019 static DecodeStatus DecodeVLDST4Instruction(MCInst &Inst, unsigned Insn,
3020                                    uint64_t Address, const void *Decoder) {
3021   unsigned size = fieldFromInstruction(Insn, 6, 2);
3022   if (size == 3) return MCDisassembler::Fail;
3023 
3024   unsigned load = fieldFromInstruction(Insn, 21, 1);
3025   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
3026               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
3027 }
3028 
3029 static DecodeStatus DecodeVSTInstruction(MCInst &Inst, unsigned Insn,
3030                                  uint64_t Address, const void *Decoder) {
3031   DecodeStatus S = MCDisassembler::Success;
3032 
3033   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3034   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3035   unsigned wb = fieldFromInstruction(Insn, 16, 4);
3036   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3037   Rn |= fieldFromInstruction(Insn, 4, 2) << 4;
3038   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3039 
3040   // Writeback Operand
3041   switch (Inst.getOpcode()) {
3042     case ARM::VST1d8wb_fixed:
3043     case ARM::VST1d16wb_fixed:
3044     case ARM::VST1d32wb_fixed:
3045     case ARM::VST1d64wb_fixed:
3046     case ARM::VST1d8wb_register:
3047     case ARM::VST1d16wb_register:
3048     case ARM::VST1d32wb_register:
3049     case ARM::VST1d64wb_register:
3050     case ARM::VST1q8wb_fixed:
3051     case ARM::VST1q16wb_fixed:
3052     case ARM::VST1q32wb_fixed:
3053     case ARM::VST1q64wb_fixed:
3054     case ARM::VST1q8wb_register:
3055     case ARM::VST1q16wb_register:
3056     case ARM::VST1q32wb_register:
3057     case ARM::VST1q64wb_register:
3058     case ARM::VST1d8Twb_fixed:
3059     case ARM::VST1d16Twb_fixed:
3060     case ARM::VST1d32Twb_fixed:
3061     case ARM::VST1d64Twb_fixed:
3062     case ARM::VST1d8Twb_register:
3063     case ARM::VST1d16Twb_register:
3064     case ARM::VST1d32Twb_register:
3065     case ARM::VST1d64Twb_register:
3066     case ARM::VST1d8Qwb_fixed:
3067     case ARM::VST1d16Qwb_fixed:
3068     case ARM::VST1d32Qwb_fixed:
3069     case ARM::VST1d64Qwb_fixed:
3070     case ARM::VST1d8Qwb_register:
3071     case ARM::VST1d16Qwb_register:
3072     case ARM::VST1d32Qwb_register:
3073     case ARM::VST1d64Qwb_register:
3074     case ARM::VST2d8wb_fixed:
3075     case ARM::VST2d16wb_fixed:
3076     case ARM::VST2d32wb_fixed:
3077     case ARM::VST2d8wb_register:
3078     case ARM::VST2d16wb_register:
3079     case ARM::VST2d32wb_register:
3080     case ARM::VST2q8wb_fixed:
3081     case ARM::VST2q16wb_fixed:
3082     case ARM::VST2q32wb_fixed:
3083     case ARM::VST2q8wb_register:
3084     case ARM::VST2q16wb_register:
3085     case ARM::VST2q32wb_register:
3086     case ARM::VST2b8wb_fixed:
3087     case ARM::VST2b16wb_fixed:
3088     case ARM::VST2b32wb_fixed:
3089     case ARM::VST2b8wb_register:
3090     case ARM::VST2b16wb_register:
3091     case ARM::VST2b32wb_register:
3092       if (Rm == 0xF)
3093         return MCDisassembler::Fail;
3094       Inst.addOperand(MCOperand::createImm(0));
3095       break;
3096     case ARM::VST3d8_UPD:
3097     case ARM::VST3d16_UPD:
3098     case ARM::VST3d32_UPD:
3099     case ARM::VST3q8_UPD:
3100     case ARM::VST3q16_UPD:
3101     case ARM::VST3q32_UPD:
3102     case ARM::VST4d8_UPD:
3103     case ARM::VST4d16_UPD:
3104     case ARM::VST4d32_UPD:
3105     case ARM::VST4q8_UPD:
3106     case ARM::VST4q16_UPD:
3107     case ARM::VST4q32_UPD:
3108       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
3109         return MCDisassembler::Fail;
3110       break;
3111     default:
3112       break;
3113   }
3114 
3115   // AddrMode6 Base (register+alignment)
3116   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
3117     return MCDisassembler::Fail;
3118 
3119   // AddrMode6 Offset (register)
3120   switch (Inst.getOpcode()) {
3121     default:
3122       if (Rm == 0xD)
3123         Inst.addOperand(MCOperand::createReg(0));
3124       else if (Rm != 0xF) {
3125         if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3126           return MCDisassembler::Fail;
3127       }
3128       break;
3129     case ARM::VST1d8wb_fixed:
3130     case ARM::VST1d16wb_fixed:
3131     case ARM::VST1d32wb_fixed:
3132     case ARM::VST1d64wb_fixed:
3133     case ARM::VST1q8wb_fixed:
3134     case ARM::VST1q16wb_fixed:
3135     case ARM::VST1q32wb_fixed:
3136     case ARM::VST1q64wb_fixed:
3137     case ARM::VST1d8Twb_fixed:
3138     case ARM::VST1d16Twb_fixed:
3139     case ARM::VST1d32Twb_fixed:
3140     case ARM::VST1d64Twb_fixed:
3141     case ARM::VST1d8Qwb_fixed:
3142     case ARM::VST1d16Qwb_fixed:
3143     case ARM::VST1d32Qwb_fixed:
3144     case ARM::VST1d64Qwb_fixed:
3145     case ARM::VST2d8wb_fixed:
3146     case ARM::VST2d16wb_fixed:
3147     case ARM::VST2d32wb_fixed:
3148     case ARM::VST2q8wb_fixed:
3149     case ARM::VST2q16wb_fixed:
3150     case ARM::VST2q32wb_fixed:
3151     case ARM::VST2b8wb_fixed:
3152     case ARM::VST2b16wb_fixed:
3153     case ARM::VST2b32wb_fixed:
3154       break;
3155   }
3156 
3157   // First input register
3158   switch (Inst.getOpcode()) {
3159   case ARM::VST1q16:
3160   case ARM::VST1q32:
3161   case ARM::VST1q64:
3162   case ARM::VST1q8:
3163   case ARM::VST1q16wb_fixed:
3164   case ARM::VST1q16wb_register:
3165   case ARM::VST1q32wb_fixed:
3166   case ARM::VST1q32wb_register:
3167   case ARM::VST1q64wb_fixed:
3168   case ARM::VST1q64wb_register:
3169   case ARM::VST1q8wb_fixed:
3170   case ARM::VST1q8wb_register:
3171   case ARM::VST2d16:
3172   case ARM::VST2d32:
3173   case ARM::VST2d8:
3174   case ARM::VST2d16wb_fixed:
3175   case ARM::VST2d16wb_register:
3176   case ARM::VST2d32wb_fixed:
3177   case ARM::VST2d32wb_register:
3178   case ARM::VST2d8wb_fixed:
3179   case ARM::VST2d8wb_register:
3180     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3181       return MCDisassembler::Fail;
3182     break;
3183   case ARM::VST2b16:
3184   case ARM::VST2b32:
3185   case ARM::VST2b8:
3186   case ARM::VST2b16wb_fixed:
3187   case ARM::VST2b16wb_register:
3188   case ARM::VST2b32wb_fixed:
3189   case ARM::VST2b32wb_register:
3190   case ARM::VST2b8wb_fixed:
3191   case ARM::VST2b8wb_register:
3192     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
3193       return MCDisassembler::Fail;
3194     break;
3195   default:
3196     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3197       return MCDisassembler::Fail;
3198   }
3199 
3200   // Second input register
3201   switch (Inst.getOpcode()) {
3202     case ARM::VST3d8:
3203     case ARM::VST3d16:
3204     case ARM::VST3d32:
3205     case ARM::VST3d8_UPD:
3206     case ARM::VST3d16_UPD:
3207     case ARM::VST3d32_UPD:
3208     case ARM::VST4d8:
3209     case ARM::VST4d16:
3210     case ARM::VST4d32:
3211     case ARM::VST4d8_UPD:
3212     case ARM::VST4d16_UPD:
3213     case ARM::VST4d32_UPD:
3214       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
3215         return MCDisassembler::Fail;
3216       break;
3217     case ARM::VST3q8:
3218     case ARM::VST3q16:
3219     case ARM::VST3q32:
3220     case ARM::VST3q8_UPD:
3221     case ARM::VST3q16_UPD:
3222     case ARM::VST3q32_UPD:
3223     case ARM::VST4q8:
3224     case ARM::VST4q16:
3225     case ARM::VST4q32:
3226     case ARM::VST4q8_UPD:
3227     case ARM::VST4q16_UPD:
3228     case ARM::VST4q32_UPD:
3229       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
3230         return MCDisassembler::Fail;
3231       break;
3232     default:
3233       break;
3234   }
3235 
3236   // Third input register
3237   switch (Inst.getOpcode()) {
3238     case ARM::VST3d8:
3239     case ARM::VST3d16:
3240     case ARM::VST3d32:
3241     case ARM::VST3d8_UPD:
3242     case ARM::VST3d16_UPD:
3243     case ARM::VST3d32_UPD:
3244     case ARM::VST4d8:
3245     case ARM::VST4d16:
3246     case ARM::VST4d32:
3247     case ARM::VST4d8_UPD:
3248     case ARM::VST4d16_UPD:
3249     case ARM::VST4d32_UPD:
3250       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
3251         return MCDisassembler::Fail;
3252       break;
3253     case ARM::VST3q8:
3254     case ARM::VST3q16:
3255     case ARM::VST3q32:
3256     case ARM::VST3q8_UPD:
3257     case ARM::VST3q16_UPD:
3258     case ARM::VST3q32_UPD:
3259     case ARM::VST4q8:
3260     case ARM::VST4q16:
3261     case ARM::VST4q32:
3262     case ARM::VST4q8_UPD:
3263     case ARM::VST4q16_UPD:
3264     case ARM::VST4q32_UPD:
3265       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
3266         return MCDisassembler::Fail;
3267       break;
3268     default:
3269       break;
3270   }
3271 
3272   // Fourth input register
3273   switch (Inst.getOpcode()) {
3274     case ARM::VST4d8:
3275     case ARM::VST4d16:
3276     case ARM::VST4d32:
3277     case ARM::VST4d8_UPD:
3278     case ARM::VST4d16_UPD:
3279     case ARM::VST4d32_UPD:
3280       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
3281         return MCDisassembler::Fail;
3282       break;
3283     case ARM::VST4q8:
3284     case ARM::VST4q16:
3285     case ARM::VST4q32:
3286     case ARM::VST4q8_UPD:
3287     case ARM::VST4q16_UPD:
3288     case ARM::VST4q32_UPD:
3289       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
3290         return MCDisassembler::Fail;
3291       break;
3292     default:
3293       break;
3294   }
3295 
3296   return S;
3297 }
3298 
3299 static DecodeStatus DecodeVLD1DupInstruction(MCInst &Inst, unsigned Insn,
3300                                     uint64_t Address, const void *Decoder) {
3301   DecodeStatus S = MCDisassembler::Success;
3302 
3303   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3304   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3305   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3306   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3307   unsigned align = fieldFromInstruction(Insn, 4, 1);
3308   unsigned size = fieldFromInstruction(Insn, 6, 2);
3309 
3310   if (size == 0 && align == 1)
3311     return MCDisassembler::Fail;
3312   align *= (1 << size);
3313 
3314   switch (Inst.getOpcode()) {
3315   case ARM::VLD1DUPq16: case ARM::VLD1DUPq32: case ARM::VLD1DUPq8:
3316   case ARM::VLD1DUPq16wb_fixed: case ARM::VLD1DUPq16wb_register:
3317   case ARM::VLD1DUPq32wb_fixed: case ARM::VLD1DUPq32wb_register:
3318   case ARM::VLD1DUPq8wb_fixed: case ARM::VLD1DUPq8wb_register:
3319     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3320       return MCDisassembler::Fail;
3321     break;
3322   default:
3323     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3324       return MCDisassembler::Fail;
3325     break;
3326   }
3327   if (Rm != 0xF) {
3328     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3329       return MCDisassembler::Fail;
3330   }
3331 
3332   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3333     return MCDisassembler::Fail;
3334   Inst.addOperand(MCOperand::createImm(align));
3335 
3336   // The fixed offset post-increment encodes Rm == 0xd. The no-writeback
3337   // variant encodes Rm == 0xf. Anything else is a register offset post-
3338   // increment and we need to add the register operand to the instruction.
3339   if (Rm != 0xD && Rm != 0xF &&
3340       !Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3341     return MCDisassembler::Fail;
3342 
3343   return S;
3344 }
3345 
3346 static DecodeStatus DecodeVLD2DupInstruction(MCInst &Inst, unsigned Insn,
3347                                     uint64_t Address, const void *Decoder) {
3348   DecodeStatus S = MCDisassembler::Success;
3349 
3350   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3351   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3352   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3353   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3354   unsigned align = fieldFromInstruction(Insn, 4, 1);
3355   unsigned size = 1 << fieldFromInstruction(Insn, 6, 2);
3356   align *= 2*size;
3357 
3358   switch (Inst.getOpcode()) {
3359   case ARM::VLD2DUPd16: case ARM::VLD2DUPd32: case ARM::VLD2DUPd8:
3360   case ARM::VLD2DUPd16wb_fixed: case ARM::VLD2DUPd16wb_register:
3361   case ARM::VLD2DUPd32wb_fixed: case ARM::VLD2DUPd32wb_register:
3362   case ARM::VLD2DUPd8wb_fixed: case ARM::VLD2DUPd8wb_register:
3363     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3364       return MCDisassembler::Fail;
3365     break;
3366   case ARM::VLD2DUPd16x2: case ARM::VLD2DUPd32x2: case ARM::VLD2DUPd8x2:
3367   case ARM::VLD2DUPd16x2wb_fixed: case ARM::VLD2DUPd16x2wb_register:
3368   case ARM::VLD2DUPd32x2wb_fixed: case ARM::VLD2DUPd32x2wb_register:
3369   case ARM::VLD2DUPd8x2wb_fixed: case ARM::VLD2DUPd8x2wb_register:
3370     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
3371       return MCDisassembler::Fail;
3372     break;
3373   default:
3374     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3375       return MCDisassembler::Fail;
3376     break;
3377   }
3378 
3379   if (Rm != 0xF)
3380     Inst.addOperand(MCOperand::createImm(0));
3381 
3382   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3383     return MCDisassembler::Fail;
3384   Inst.addOperand(MCOperand::createImm(align));
3385 
3386   if (Rm != 0xD && Rm != 0xF) {
3387     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3388       return MCDisassembler::Fail;
3389   }
3390 
3391   return S;
3392 }
3393 
3394 static DecodeStatus DecodeVLD3DupInstruction(MCInst &Inst, unsigned Insn,
3395                                     uint64_t Address, const void *Decoder) {
3396   DecodeStatus S = MCDisassembler::Success;
3397 
3398   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3399   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3400   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3401   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3402   unsigned inc = fieldFromInstruction(Insn, 5, 1) + 1;
3403 
3404   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3405     return MCDisassembler::Fail;
3406   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
3407     return MCDisassembler::Fail;
3408   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
3409     return MCDisassembler::Fail;
3410   if (Rm != 0xF) {
3411     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3412       return MCDisassembler::Fail;
3413   }
3414 
3415   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3416     return MCDisassembler::Fail;
3417   Inst.addOperand(MCOperand::createImm(0));
3418 
3419   if (Rm == 0xD)
3420     Inst.addOperand(MCOperand::createReg(0));
3421   else if (Rm != 0xF) {
3422     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3423       return MCDisassembler::Fail;
3424   }
3425 
3426   return S;
3427 }
3428 
3429 static DecodeStatus DecodeVLD4DupInstruction(MCInst &Inst, unsigned Insn,
3430                                     uint64_t Address, const void *Decoder) {
3431   DecodeStatus S = MCDisassembler::Success;
3432 
3433   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3434   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3435   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3436   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3437   unsigned size = fieldFromInstruction(Insn, 6, 2);
3438   unsigned inc = fieldFromInstruction(Insn, 5, 1) + 1;
3439   unsigned align = fieldFromInstruction(Insn, 4, 1);
3440 
3441   if (size == 0x3) {
3442     if (align == 0)
3443       return MCDisassembler::Fail;
3444     align = 16;
3445   } else {
3446     if (size == 2) {
3447       align *= 8;
3448     } else {
3449       size = 1 << size;
3450       align *= 4*size;
3451     }
3452   }
3453 
3454   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3455     return MCDisassembler::Fail;
3456   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
3457     return MCDisassembler::Fail;
3458   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
3459     return MCDisassembler::Fail;
3460   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3*inc)%32, Address, Decoder)))
3461     return MCDisassembler::Fail;
3462   if (Rm != 0xF) {
3463     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3464       return MCDisassembler::Fail;
3465   }
3466 
3467   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3468     return MCDisassembler::Fail;
3469   Inst.addOperand(MCOperand::createImm(align));
3470 
3471   if (Rm == 0xD)
3472     Inst.addOperand(MCOperand::createReg(0));
3473   else if (Rm != 0xF) {
3474     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3475       return MCDisassembler::Fail;
3476   }
3477 
3478   return S;
3479 }
3480 
3481 static DecodeStatus
3482 DecodeVMOVModImmInstruction(MCInst &Inst, unsigned Insn,
3483                             uint64_t Address, const void *Decoder) {
3484   DecodeStatus S = MCDisassembler::Success;
3485 
3486   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3487   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3488   unsigned imm = fieldFromInstruction(Insn, 0, 4);
3489   imm |= fieldFromInstruction(Insn, 16, 3) << 4;
3490   imm |= fieldFromInstruction(Insn, 24, 1) << 7;
3491   imm |= fieldFromInstruction(Insn, 8, 4) << 8;
3492   imm |= fieldFromInstruction(Insn, 5, 1) << 12;
3493   unsigned Q = fieldFromInstruction(Insn, 6, 1);
3494 
3495   if (Q) {
3496     if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3497     return MCDisassembler::Fail;
3498   } else {
3499     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3500     return MCDisassembler::Fail;
3501   }
3502 
3503   Inst.addOperand(MCOperand::createImm(imm));
3504 
3505   switch (Inst.getOpcode()) {
3506     case ARM::VORRiv4i16:
3507     case ARM::VORRiv2i32:
3508     case ARM::VBICiv4i16:
3509     case ARM::VBICiv2i32:
3510       if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3511         return MCDisassembler::Fail;
3512       break;
3513     case ARM::VORRiv8i16:
3514     case ARM::VORRiv4i32:
3515     case ARM::VBICiv8i16:
3516     case ARM::VBICiv4i32:
3517       if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3518         return MCDisassembler::Fail;
3519       break;
3520     default:
3521       break;
3522   }
3523 
3524   return S;
3525 }
3526 
3527 static DecodeStatus
3528 DecodeMVEModImmInstruction(MCInst &Inst, unsigned Insn,
3529                            uint64_t Address, const void *Decoder) {
3530   DecodeStatus S = MCDisassembler::Success;
3531 
3532   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
3533                  fieldFromInstruction(Insn, 13, 3));
3534   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
3535   unsigned imm = fieldFromInstruction(Insn, 0, 4);
3536   imm |= fieldFromInstruction(Insn, 16, 3) << 4;
3537   imm |= fieldFromInstruction(Insn, 28, 1) << 7;
3538   imm |= cmode                             << 8;
3539   imm |= fieldFromInstruction(Insn, 5, 1)  << 12;
3540 
3541   if (cmode == 0xF && Inst.getOpcode() == ARM::MVE_VMVNimmi32)
3542     return MCDisassembler::Fail;
3543 
3544   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
3545     return MCDisassembler::Fail;
3546 
3547   Inst.addOperand(MCOperand::createImm(imm));
3548 
3549   Inst.addOperand(MCOperand::createImm(ARMVCC::None));
3550   Inst.addOperand(MCOperand::createReg(0));
3551   Inst.addOperand(MCOperand::createImm(0));
3552 
3553   return S;
3554 }
3555 
3556 static DecodeStatus DecodeMVEVADCInstruction(MCInst &Inst, unsigned Insn,
3557                                uint64_t Address, const void *Decoder) {
3558   DecodeStatus S = MCDisassembler::Success;
3559 
3560   unsigned Qd = fieldFromInstruction(Insn, 13, 3);
3561   Qd |= fieldFromInstruction(Insn, 22, 1) << 3;
3562   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
3563     return MCDisassembler::Fail;
3564   Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
3565 
3566   unsigned Qn = fieldFromInstruction(Insn, 17, 3);
3567   Qn |= fieldFromInstruction(Insn, 7, 1) << 3;
3568   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qn, Address, Decoder)))
3569     return MCDisassembler::Fail;
3570   unsigned Qm = fieldFromInstruction(Insn, 1, 3);
3571   Qm |= fieldFromInstruction(Insn, 5, 1) << 3;
3572   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
3573     return MCDisassembler::Fail;
3574   if (!fieldFromInstruction(Insn, 12, 1)) // I bit clear => need input FPSCR
3575     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
3576   Inst.addOperand(MCOperand::createImm(Qd));
3577 
3578   return S;
3579 }
3580 
3581 static DecodeStatus DecodeVSHLMaxInstruction(MCInst &Inst, unsigned Insn,
3582                                         uint64_t Address, const void *Decoder) {
3583   DecodeStatus S = MCDisassembler::Success;
3584 
3585   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3586   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3587   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3588   Rm |= fieldFromInstruction(Insn, 5, 1) << 4;
3589   unsigned size = fieldFromInstruction(Insn, 18, 2);
3590 
3591   if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3592     return MCDisassembler::Fail;
3593   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
3594     return MCDisassembler::Fail;
3595   Inst.addOperand(MCOperand::createImm(8 << size));
3596 
3597   return S;
3598 }
3599 
3600 static DecodeStatus DecodeShiftRight8Imm(MCInst &Inst, unsigned Val,
3601                                uint64_t Address, const void *Decoder) {
3602   Inst.addOperand(MCOperand::createImm(8 - Val));
3603   return MCDisassembler::Success;
3604 }
3605 
3606 static DecodeStatus DecodeShiftRight16Imm(MCInst &Inst, unsigned Val,
3607                                uint64_t Address, const void *Decoder) {
3608   Inst.addOperand(MCOperand::createImm(16 - Val));
3609   return MCDisassembler::Success;
3610 }
3611 
3612 static DecodeStatus DecodeShiftRight32Imm(MCInst &Inst, unsigned Val,
3613                                uint64_t Address, const void *Decoder) {
3614   Inst.addOperand(MCOperand::createImm(32 - Val));
3615   return MCDisassembler::Success;
3616 }
3617 
3618 static DecodeStatus DecodeShiftRight64Imm(MCInst &Inst, unsigned Val,
3619                                uint64_t Address, const void *Decoder) {
3620   Inst.addOperand(MCOperand::createImm(64 - Val));
3621   return MCDisassembler::Success;
3622 }
3623 
3624 static DecodeStatus DecodeTBLInstruction(MCInst &Inst, unsigned Insn,
3625                                uint64_t Address, const void *Decoder) {
3626   DecodeStatus S = MCDisassembler::Success;
3627 
3628   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3629   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3630   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3631   Rn |= fieldFromInstruction(Insn, 7, 1) << 4;
3632   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3633   Rm |= fieldFromInstruction(Insn, 5, 1) << 4;
3634   unsigned op = fieldFromInstruction(Insn, 6, 1);
3635 
3636   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3637     return MCDisassembler::Fail;
3638   if (op) {
3639     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3640     return MCDisassembler::Fail; // Writeback
3641   }
3642 
3643   switch (Inst.getOpcode()) {
3644   case ARM::VTBL2:
3645   case ARM::VTBX2:
3646     if (!Check(S, DecodeDPairRegisterClass(Inst, Rn, Address, Decoder)))
3647       return MCDisassembler::Fail;
3648     break;
3649   default:
3650     if (!Check(S, DecodeDPRRegisterClass(Inst, Rn, Address, Decoder)))
3651       return MCDisassembler::Fail;
3652   }
3653 
3654   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
3655     return MCDisassembler::Fail;
3656 
3657   return S;
3658 }
3659 
3660 static DecodeStatus DecodeThumbAddSpecialReg(MCInst &Inst, uint16_t Insn,
3661                                      uint64_t Address, const void *Decoder) {
3662   DecodeStatus S = MCDisassembler::Success;
3663 
3664   unsigned dst = fieldFromInstruction(Insn, 8, 3);
3665   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3666 
3667   if (!Check(S, DecodetGPRRegisterClass(Inst, dst, Address, Decoder)))
3668     return MCDisassembler::Fail;
3669 
3670   switch(Inst.getOpcode()) {
3671     default:
3672       return MCDisassembler::Fail;
3673     case ARM::tADR:
3674       break; // tADR does not explicitly represent the PC as an operand.
3675     case ARM::tADDrSPi:
3676       Inst.addOperand(MCOperand::createReg(ARM::SP));
3677       break;
3678   }
3679 
3680   Inst.addOperand(MCOperand::createImm(imm));
3681   return S;
3682 }
3683 
3684 static DecodeStatus DecodeThumbBROperand(MCInst &Inst, unsigned Val,
3685                                  uint64_t Address, const void *Decoder) {
3686   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<12>(Val<<1) + 4,
3687                                 true, 2, Inst, Decoder))
3688     Inst.addOperand(MCOperand::createImm(SignExtend32<12>(Val << 1)));
3689   return MCDisassembler::Success;
3690 }
3691 
3692 static DecodeStatus DecodeT2BROperand(MCInst &Inst, unsigned Val,
3693                                  uint64_t Address, const void *Decoder) {
3694   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<21>(Val) + 4,
3695                                 true, 4, Inst, Decoder))
3696     Inst.addOperand(MCOperand::createImm(SignExtend32<21>(Val)));
3697   return MCDisassembler::Success;
3698 }
3699 
3700 static DecodeStatus DecodeThumbCmpBROperand(MCInst &Inst, unsigned Val,
3701                                  uint64_t Address, const void *Decoder) {
3702   if (!tryAddingSymbolicOperand(Address, Address + (Val<<1) + 4,
3703                                 true, 2, Inst, Decoder))
3704     Inst.addOperand(MCOperand::createImm(Val << 1));
3705   return MCDisassembler::Success;
3706 }
3707 
3708 static DecodeStatus DecodeThumbAddrModeRR(MCInst &Inst, unsigned Val,
3709                                  uint64_t Address, const void *Decoder) {
3710   DecodeStatus S = MCDisassembler::Success;
3711 
3712   unsigned Rn = fieldFromInstruction(Val, 0, 3);
3713   unsigned Rm = fieldFromInstruction(Val, 3, 3);
3714 
3715   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
3716     return MCDisassembler::Fail;
3717   if (!Check(S, DecodetGPRRegisterClass(Inst, Rm, Address, Decoder)))
3718     return MCDisassembler::Fail;
3719 
3720   return S;
3721 }
3722 
3723 static DecodeStatus DecodeThumbAddrModeIS(MCInst &Inst, unsigned Val,
3724                                   uint64_t Address, const void *Decoder) {
3725   DecodeStatus S = MCDisassembler::Success;
3726 
3727   unsigned Rn = fieldFromInstruction(Val, 0, 3);
3728   unsigned imm = fieldFromInstruction(Val, 3, 5);
3729 
3730   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
3731     return MCDisassembler::Fail;
3732   Inst.addOperand(MCOperand::createImm(imm));
3733 
3734   return S;
3735 }
3736 
3737 static DecodeStatus DecodeThumbAddrModePC(MCInst &Inst, unsigned Val,
3738                                   uint64_t Address, const void *Decoder) {
3739   unsigned imm = Val << 2;
3740 
3741   Inst.addOperand(MCOperand::createImm(imm));
3742   tryAddingPcLoadReferenceComment(Address, (Address & ~2u) + imm + 4, Decoder);
3743 
3744   return MCDisassembler::Success;
3745 }
3746 
3747 static DecodeStatus DecodeThumbAddrModeSP(MCInst &Inst, unsigned Val,
3748                                   uint64_t Address, const void *Decoder) {
3749   Inst.addOperand(MCOperand::createReg(ARM::SP));
3750   Inst.addOperand(MCOperand::createImm(Val));
3751 
3752   return MCDisassembler::Success;
3753 }
3754 
3755 static DecodeStatus DecodeT2AddrModeSOReg(MCInst &Inst, unsigned Val,
3756                                   uint64_t Address, const void *Decoder) {
3757   DecodeStatus S = MCDisassembler::Success;
3758 
3759   unsigned Rn = fieldFromInstruction(Val, 6, 4);
3760   unsigned Rm = fieldFromInstruction(Val, 2, 4);
3761   unsigned imm = fieldFromInstruction(Val, 0, 2);
3762 
3763   // Thumb stores cannot use PC as dest register.
3764   switch (Inst.getOpcode()) {
3765   case ARM::t2STRHs:
3766   case ARM::t2STRBs:
3767   case ARM::t2STRs:
3768     if (Rn == 15)
3769       return MCDisassembler::Fail;
3770     break;
3771   default:
3772     break;
3773   }
3774 
3775   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3776     return MCDisassembler::Fail;
3777   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
3778     return MCDisassembler::Fail;
3779   Inst.addOperand(MCOperand::createImm(imm));
3780 
3781   return S;
3782 }
3783 
3784 static DecodeStatus DecodeT2LoadShift(MCInst &Inst, unsigned Insn,
3785                               uint64_t Address, const void *Decoder) {
3786   DecodeStatus S = MCDisassembler::Success;
3787 
3788   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3789   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3790 
3791   const FeatureBitset &featureBits =
3792     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3793 
3794   bool hasMP = featureBits[ARM::FeatureMP];
3795   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3796 
3797   if (Rn == 15) {
3798     switch (Inst.getOpcode()) {
3799     case ARM::t2LDRBs:
3800       Inst.setOpcode(ARM::t2LDRBpci);
3801       break;
3802     case ARM::t2LDRHs:
3803       Inst.setOpcode(ARM::t2LDRHpci);
3804       break;
3805     case ARM::t2LDRSHs:
3806       Inst.setOpcode(ARM::t2LDRSHpci);
3807       break;
3808     case ARM::t2LDRSBs:
3809       Inst.setOpcode(ARM::t2LDRSBpci);
3810       break;
3811     case ARM::t2LDRs:
3812       Inst.setOpcode(ARM::t2LDRpci);
3813       break;
3814     case ARM::t2PLDs:
3815       Inst.setOpcode(ARM::t2PLDpci);
3816       break;
3817     case ARM::t2PLIs:
3818       Inst.setOpcode(ARM::t2PLIpci);
3819       break;
3820     default:
3821       return MCDisassembler::Fail;
3822     }
3823 
3824     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3825   }
3826 
3827   if (Rt == 15) {
3828     switch (Inst.getOpcode()) {
3829     case ARM::t2LDRSHs:
3830       return MCDisassembler::Fail;
3831     case ARM::t2LDRHs:
3832       Inst.setOpcode(ARM::t2PLDWs);
3833       break;
3834     case ARM::t2LDRSBs:
3835       Inst.setOpcode(ARM::t2PLIs);
3836       break;
3837     default:
3838       break;
3839     }
3840   }
3841 
3842   switch (Inst.getOpcode()) {
3843     case ARM::t2PLDs:
3844       break;
3845     case ARM::t2PLIs:
3846       if (!hasV7Ops)
3847         return MCDisassembler::Fail;
3848       break;
3849     case ARM::t2PLDWs:
3850       if (!hasV7Ops || !hasMP)
3851         return MCDisassembler::Fail;
3852       break;
3853     default:
3854       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3855         return MCDisassembler::Fail;
3856   }
3857 
3858   unsigned addrmode = fieldFromInstruction(Insn, 4, 2);
3859   addrmode |= fieldFromInstruction(Insn, 0, 4) << 2;
3860   addrmode |= fieldFromInstruction(Insn, 16, 4) << 6;
3861   if (!Check(S, DecodeT2AddrModeSOReg(Inst, addrmode, Address, Decoder)))
3862     return MCDisassembler::Fail;
3863 
3864   return S;
3865 }
3866 
3867 static DecodeStatus DecodeT2LoadImm8(MCInst &Inst, unsigned Insn,
3868                                 uint64_t Address, const void* Decoder) {
3869   DecodeStatus S = MCDisassembler::Success;
3870 
3871   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3872   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3873   unsigned U = fieldFromInstruction(Insn, 9, 1);
3874   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3875   imm |= (U << 8);
3876   imm |= (Rn << 9);
3877   unsigned add = fieldFromInstruction(Insn, 9, 1);
3878 
3879   const FeatureBitset &featureBits =
3880     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3881 
3882   bool hasMP = featureBits[ARM::FeatureMP];
3883   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3884 
3885   if (Rn == 15) {
3886     switch (Inst.getOpcode()) {
3887     case ARM::t2LDRi8:
3888       Inst.setOpcode(ARM::t2LDRpci);
3889       break;
3890     case ARM::t2LDRBi8:
3891       Inst.setOpcode(ARM::t2LDRBpci);
3892       break;
3893     case ARM::t2LDRSBi8:
3894       Inst.setOpcode(ARM::t2LDRSBpci);
3895       break;
3896     case ARM::t2LDRHi8:
3897       Inst.setOpcode(ARM::t2LDRHpci);
3898       break;
3899     case ARM::t2LDRSHi8:
3900       Inst.setOpcode(ARM::t2LDRSHpci);
3901       break;
3902     case ARM::t2PLDi8:
3903       Inst.setOpcode(ARM::t2PLDpci);
3904       break;
3905     case ARM::t2PLIi8:
3906       Inst.setOpcode(ARM::t2PLIpci);
3907       break;
3908     default:
3909       return MCDisassembler::Fail;
3910     }
3911     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3912   }
3913 
3914   if (Rt == 15) {
3915     switch (Inst.getOpcode()) {
3916     case ARM::t2LDRSHi8:
3917       return MCDisassembler::Fail;
3918     case ARM::t2LDRHi8:
3919       if (!add)
3920         Inst.setOpcode(ARM::t2PLDWi8);
3921       break;
3922     case ARM::t2LDRSBi8:
3923       Inst.setOpcode(ARM::t2PLIi8);
3924       break;
3925     default:
3926       break;
3927     }
3928   }
3929 
3930   switch (Inst.getOpcode()) {
3931   case ARM::t2PLDi8:
3932     break;
3933   case ARM::t2PLIi8:
3934     if (!hasV7Ops)
3935       return MCDisassembler::Fail;
3936     break;
3937   case ARM::t2PLDWi8:
3938       if (!hasV7Ops || !hasMP)
3939         return MCDisassembler::Fail;
3940       break;
3941   default:
3942     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3943       return MCDisassembler::Fail;
3944   }
3945 
3946   if (!Check(S, DecodeT2AddrModeImm8(Inst, imm, Address, Decoder)))
3947     return MCDisassembler::Fail;
3948   return S;
3949 }
3950 
3951 static DecodeStatus DecodeT2LoadImm12(MCInst &Inst, unsigned Insn,
3952                                 uint64_t Address, const void* Decoder) {
3953   DecodeStatus S = MCDisassembler::Success;
3954 
3955   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3956   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3957   unsigned imm = fieldFromInstruction(Insn, 0, 12);
3958   imm |= (Rn << 13);
3959 
3960   const FeatureBitset &featureBits =
3961     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3962 
3963   bool hasMP = featureBits[ARM::FeatureMP];
3964   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3965 
3966   if (Rn == 15) {
3967     switch (Inst.getOpcode()) {
3968     case ARM::t2LDRi12:
3969       Inst.setOpcode(ARM::t2LDRpci);
3970       break;
3971     case ARM::t2LDRHi12:
3972       Inst.setOpcode(ARM::t2LDRHpci);
3973       break;
3974     case ARM::t2LDRSHi12:
3975       Inst.setOpcode(ARM::t2LDRSHpci);
3976       break;
3977     case ARM::t2LDRBi12:
3978       Inst.setOpcode(ARM::t2LDRBpci);
3979       break;
3980     case ARM::t2LDRSBi12:
3981       Inst.setOpcode(ARM::t2LDRSBpci);
3982       break;
3983     case ARM::t2PLDi12:
3984       Inst.setOpcode(ARM::t2PLDpci);
3985       break;
3986     case ARM::t2PLIi12:
3987       Inst.setOpcode(ARM::t2PLIpci);
3988       break;
3989     default:
3990       return MCDisassembler::Fail;
3991     }
3992     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3993   }
3994 
3995   if (Rt == 15) {
3996     switch (Inst.getOpcode()) {
3997     case ARM::t2LDRSHi12:
3998       return MCDisassembler::Fail;
3999     case ARM::t2LDRHi12:
4000       Inst.setOpcode(ARM::t2PLDWi12);
4001       break;
4002     case ARM::t2LDRSBi12:
4003       Inst.setOpcode(ARM::t2PLIi12);
4004       break;
4005     default:
4006       break;
4007     }
4008   }
4009 
4010   switch (Inst.getOpcode()) {
4011   case ARM::t2PLDi12:
4012     break;
4013   case ARM::t2PLIi12:
4014     if (!hasV7Ops)
4015       return MCDisassembler::Fail;
4016     break;
4017   case ARM::t2PLDWi12:
4018       if (!hasV7Ops || !hasMP)
4019         return MCDisassembler::Fail;
4020       break;
4021   default:
4022     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4023       return MCDisassembler::Fail;
4024   }
4025 
4026   if (!Check(S, DecodeT2AddrModeImm12(Inst, imm, Address, Decoder)))
4027     return MCDisassembler::Fail;
4028   return S;
4029 }
4030 
4031 static DecodeStatus DecodeT2LoadT(MCInst &Inst, unsigned Insn,
4032                                 uint64_t Address, const void* Decoder) {
4033   DecodeStatus S = MCDisassembler::Success;
4034 
4035   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4036   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4037   unsigned imm = fieldFromInstruction(Insn, 0, 8);
4038   imm |= (Rn << 9);
4039 
4040   if (Rn == 15) {
4041     switch (Inst.getOpcode()) {
4042     case ARM::t2LDRT:
4043       Inst.setOpcode(ARM::t2LDRpci);
4044       break;
4045     case ARM::t2LDRBT:
4046       Inst.setOpcode(ARM::t2LDRBpci);
4047       break;
4048     case ARM::t2LDRHT:
4049       Inst.setOpcode(ARM::t2LDRHpci);
4050       break;
4051     case ARM::t2LDRSBT:
4052       Inst.setOpcode(ARM::t2LDRSBpci);
4053       break;
4054     case ARM::t2LDRSHT:
4055       Inst.setOpcode(ARM::t2LDRSHpci);
4056       break;
4057     default:
4058       return MCDisassembler::Fail;
4059     }
4060     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
4061   }
4062 
4063   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
4064     return MCDisassembler::Fail;
4065   if (!Check(S, DecodeT2AddrModeImm8(Inst, imm, Address, Decoder)))
4066     return MCDisassembler::Fail;
4067   return S;
4068 }
4069 
4070 static DecodeStatus DecodeT2LoadLabel(MCInst &Inst, unsigned Insn,
4071                                 uint64_t Address, const void* Decoder) {
4072   DecodeStatus S = MCDisassembler::Success;
4073 
4074   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4075   unsigned U = fieldFromInstruction(Insn, 23, 1);
4076   int imm = fieldFromInstruction(Insn, 0, 12);
4077 
4078   const FeatureBitset &featureBits =
4079     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4080 
4081   bool hasV7Ops = featureBits[ARM::HasV7Ops];
4082 
4083   if (Rt == 15) {
4084     switch (Inst.getOpcode()) {
4085       case ARM::t2LDRBpci:
4086       case ARM::t2LDRHpci:
4087         Inst.setOpcode(ARM::t2PLDpci);
4088         break;
4089       case ARM::t2LDRSBpci:
4090         Inst.setOpcode(ARM::t2PLIpci);
4091         break;
4092       case ARM::t2LDRSHpci:
4093         return MCDisassembler::Fail;
4094       default:
4095         break;
4096     }
4097   }
4098 
4099   switch(Inst.getOpcode()) {
4100   case ARM::t2PLDpci:
4101     break;
4102   case ARM::t2PLIpci:
4103     if (!hasV7Ops)
4104       return MCDisassembler::Fail;
4105     break;
4106   default:
4107     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4108       return MCDisassembler::Fail;
4109   }
4110 
4111   if (!U) {
4112     // Special case for #-0.
4113     if (imm == 0)
4114       imm = INT32_MIN;
4115     else
4116       imm = -imm;
4117   }
4118   Inst.addOperand(MCOperand::createImm(imm));
4119 
4120   return S;
4121 }
4122 
4123 static DecodeStatus DecodeT2Imm8S4(MCInst &Inst, unsigned Val,
4124                            uint64_t Address, const void *Decoder) {
4125   if (Val == 0)
4126     Inst.addOperand(MCOperand::createImm(INT32_MIN));
4127   else {
4128     int imm = Val & 0xFF;
4129 
4130     if (!(Val & 0x100)) imm *= -1;
4131     Inst.addOperand(MCOperand::createImm(imm * 4));
4132   }
4133 
4134   return MCDisassembler::Success;
4135 }
4136 
4137 static DecodeStatus DecodeT2Imm7S4(MCInst &Inst, unsigned Val, uint64_t Address,
4138                                    const void *Decoder) {
4139   if (Val == 0)
4140     Inst.addOperand(MCOperand::createImm(INT32_MIN));
4141   else {
4142     int imm = Val & 0x7F;
4143 
4144     if (!(Val & 0x80))
4145       imm *= -1;
4146     Inst.addOperand(MCOperand::createImm(imm * 4));
4147   }
4148 
4149   return MCDisassembler::Success;
4150 }
4151 
4152 static DecodeStatus DecodeT2AddrModeImm8s4(MCInst &Inst, unsigned Val,
4153                                    uint64_t Address, const void *Decoder) {
4154   DecodeStatus S = MCDisassembler::Success;
4155 
4156   unsigned Rn = fieldFromInstruction(Val, 9, 4);
4157   unsigned imm = fieldFromInstruction(Val, 0, 9);
4158 
4159   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4160     return MCDisassembler::Fail;
4161   if (!Check(S, DecodeT2Imm8S4(Inst, imm, Address, Decoder)))
4162     return MCDisassembler::Fail;
4163 
4164   return S;
4165 }
4166 
4167 static DecodeStatus DecodeT2AddrModeImm7s4(MCInst &Inst, unsigned Val,
4168                                            uint64_t Address,
4169                                            const void *Decoder) {
4170   DecodeStatus S = MCDisassembler::Success;
4171 
4172   unsigned Rn = fieldFromInstruction(Val, 8, 4);
4173   unsigned imm = fieldFromInstruction(Val, 0, 8);
4174 
4175   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4176     return MCDisassembler::Fail;
4177   if (!Check(S, DecodeT2Imm7S4(Inst, imm, Address, Decoder)))
4178     return MCDisassembler::Fail;
4179 
4180   return S;
4181 }
4182 
4183 static DecodeStatus DecodeT2AddrModeImm0_1020s4(MCInst &Inst,unsigned Val,
4184                                    uint64_t Address, const void *Decoder) {
4185   DecodeStatus S = MCDisassembler::Success;
4186 
4187   unsigned Rn = fieldFromInstruction(Val, 8, 4);
4188   unsigned imm = fieldFromInstruction(Val, 0, 8);
4189 
4190   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4191     return MCDisassembler::Fail;
4192 
4193   Inst.addOperand(MCOperand::createImm(imm));
4194 
4195   return S;
4196 }
4197 
4198 static DecodeStatus DecodeT2Imm8(MCInst &Inst, unsigned Val,
4199                          uint64_t Address, const void *Decoder) {
4200   int imm = Val & 0xFF;
4201   if (Val == 0)
4202     imm = INT32_MIN;
4203   else if (!(Val & 0x100))
4204     imm *= -1;
4205   Inst.addOperand(MCOperand::createImm(imm));
4206 
4207   return MCDisassembler::Success;
4208 }
4209 
4210 template<int shift>
4211 static DecodeStatus DecodeT2Imm7(MCInst &Inst, unsigned Val,
4212                          uint64_t Address, const void *Decoder) {
4213   int imm = Val & 0x7F;
4214   if (Val == 0)
4215     imm = INT32_MIN;
4216   else if (!(Val & 0x80))
4217     imm *= -1;
4218   if (imm != INT32_MIN)
4219     imm *= (1U << shift);
4220   Inst.addOperand(MCOperand::createImm(imm));
4221 
4222   return MCDisassembler::Success;
4223 }
4224 
4225 static DecodeStatus DecodeT2AddrModeImm8(MCInst &Inst, unsigned Val,
4226                                  uint64_t Address, const void *Decoder) {
4227   DecodeStatus S = MCDisassembler::Success;
4228 
4229   unsigned Rn = fieldFromInstruction(Val, 9, 4);
4230   unsigned imm = fieldFromInstruction(Val, 0, 9);
4231 
4232   // Thumb stores cannot use PC as dest register.
4233   switch (Inst.getOpcode()) {
4234   case ARM::t2STRT:
4235   case ARM::t2STRBT:
4236   case ARM::t2STRHT:
4237   case ARM::t2STRi8:
4238   case ARM::t2STRHi8:
4239   case ARM::t2STRBi8:
4240     if (Rn == 15)
4241       return MCDisassembler::Fail;
4242     break;
4243   default:
4244     break;
4245   }
4246 
4247   // Some instructions always use an additive offset.
4248   switch (Inst.getOpcode()) {
4249     case ARM::t2LDRT:
4250     case ARM::t2LDRBT:
4251     case ARM::t2LDRHT:
4252     case ARM::t2LDRSBT:
4253     case ARM::t2LDRSHT:
4254     case ARM::t2STRT:
4255     case ARM::t2STRBT:
4256     case ARM::t2STRHT:
4257       imm |= 0x100;
4258       break;
4259     default:
4260       break;
4261   }
4262 
4263   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4264     return MCDisassembler::Fail;
4265   if (!Check(S, DecodeT2Imm8(Inst, imm, Address, Decoder)))
4266     return MCDisassembler::Fail;
4267 
4268   return S;
4269 }
4270 
4271 template<int shift>
4272 static DecodeStatus DecodeTAddrModeImm7(MCInst &Inst, unsigned Val,
4273                                          uint64_t Address,
4274                                          const void *Decoder) {
4275   DecodeStatus S = MCDisassembler::Success;
4276 
4277   unsigned Rn = fieldFromInstruction(Val, 8, 3);
4278   unsigned imm = fieldFromInstruction(Val, 0, 8);
4279 
4280   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
4281     return MCDisassembler::Fail;
4282   if (!Check(S, DecodeT2Imm7<shift>(Inst, imm, Address, Decoder)))
4283     return MCDisassembler::Fail;
4284 
4285   return S;
4286 }
4287 
4288 template<int shift, int WriteBack>
4289 static DecodeStatus DecodeT2AddrModeImm7(MCInst &Inst, unsigned Val,
4290                                          uint64_t Address,
4291                                          const void *Decoder) {
4292   DecodeStatus S = MCDisassembler::Success;
4293 
4294   unsigned Rn = fieldFromInstruction(Val, 8, 4);
4295   unsigned imm = fieldFromInstruction(Val, 0, 8);
4296   if (WriteBack) {
4297     if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
4298       return MCDisassembler::Fail;
4299   } else if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4300     return MCDisassembler::Fail;
4301   if (!Check(S, DecodeT2Imm7<shift>(Inst, imm, Address, Decoder)))
4302     return MCDisassembler::Fail;
4303 
4304   return S;
4305 }
4306 
4307 static DecodeStatus DecodeT2LdStPre(MCInst &Inst, unsigned Insn,
4308                                     uint64_t Address, const void *Decoder) {
4309   DecodeStatus S = MCDisassembler::Success;
4310 
4311   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4312   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4313   unsigned addr = fieldFromInstruction(Insn, 0, 8);
4314   addr |= fieldFromInstruction(Insn, 9, 1) << 8;
4315   addr |= Rn << 9;
4316   unsigned load = fieldFromInstruction(Insn, 20, 1);
4317 
4318   if (Rn == 15) {
4319     switch (Inst.getOpcode()) {
4320     case ARM::t2LDR_PRE:
4321     case ARM::t2LDR_POST:
4322       Inst.setOpcode(ARM::t2LDRpci);
4323       break;
4324     case ARM::t2LDRB_PRE:
4325     case ARM::t2LDRB_POST:
4326       Inst.setOpcode(ARM::t2LDRBpci);
4327       break;
4328     case ARM::t2LDRH_PRE:
4329     case ARM::t2LDRH_POST:
4330       Inst.setOpcode(ARM::t2LDRHpci);
4331       break;
4332     case ARM::t2LDRSB_PRE:
4333     case ARM::t2LDRSB_POST:
4334       if (Rt == 15)
4335         Inst.setOpcode(ARM::t2PLIpci);
4336       else
4337         Inst.setOpcode(ARM::t2LDRSBpci);
4338       break;
4339     case ARM::t2LDRSH_PRE:
4340     case ARM::t2LDRSH_POST:
4341       Inst.setOpcode(ARM::t2LDRSHpci);
4342       break;
4343     default:
4344       return MCDisassembler::Fail;
4345     }
4346     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
4347   }
4348 
4349   if (!load) {
4350     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4351       return MCDisassembler::Fail;
4352   }
4353 
4354   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4355     return MCDisassembler::Fail;
4356 
4357   if (load) {
4358     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4359       return MCDisassembler::Fail;
4360   }
4361 
4362   if (!Check(S, DecodeT2AddrModeImm8(Inst, addr, Address, Decoder)))
4363     return MCDisassembler::Fail;
4364 
4365   return S;
4366 }
4367 
4368 static DecodeStatus DecodeT2AddrModeImm12(MCInst &Inst, unsigned Val,
4369                                   uint64_t Address, const void *Decoder) {
4370   DecodeStatus S = MCDisassembler::Success;
4371 
4372   unsigned Rn = fieldFromInstruction(Val, 13, 4);
4373   unsigned imm = fieldFromInstruction(Val, 0, 12);
4374 
4375   // Thumb stores cannot use PC as dest register.
4376   switch (Inst.getOpcode()) {
4377   case ARM::t2STRi12:
4378   case ARM::t2STRBi12:
4379   case ARM::t2STRHi12:
4380     if (Rn == 15)
4381       return MCDisassembler::Fail;
4382     break;
4383   default:
4384     break;
4385   }
4386 
4387   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4388     return MCDisassembler::Fail;
4389   Inst.addOperand(MCOperand::createImm(imm));
4390 
4391   return S;
4392 }
4393 
4394 static DecodeStatus DecodeThumbAddSPImm(MCInst &Inst, uint16_t Insn,
4395                                 uint64_t Address, const void *Decoder) {
4396   unsigned imm = fieldFromInstruction(Insn, 0, 7);
4397 
4398   Inst.addOperand(MCOperand::createReg(ARM::SP));
4399   Inst.addOperand(MCOperand::createReg(ARM::SP));
4400   Inst.addOperand(MCOperand::createImm(imm));
4401 
4402   return MCDisassembler::Success;
4403 }
4404 
4405 static DecodeStatus DecodeThumbAddSPReg(MCInst &Inst, uint16_t Insn,
4406                                 uint64_t Address, const void *Decoder) {
4407   DecodeStatus S = MCDisassembler::Success;
4408 
4409   if (Inst.getOpcode() == ARM::tADDrSP) {
4410     unsigned Rdm = fieldFromInstruction(Insn, 0, 3);
4411     Rdm |= fieldFromInstruction(Insn, 7, 1) << 3;
4412 
4413     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
4414     return MCDisassembler::Fail;
4415     Inst.addOperand(MCOperand::createReg(ARM::SP));
4416     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
4417     return MCDisassembler::Fail;
4418   } else if (Inst.getOpcode() == ARM::tADDspr) {
4419     unsigned Rm = fieldFromInstruction(Insn, 3, 4);
4420 
4421     Inst.addOperand(MCOperand::createReg(ARM::SP));
4422     Inst.addOperand(MCOperand::createReg(ARM::SP));
4423     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4424     return MCDisassembler::Fail;
4425   }
4426 
4427   return S;
4428 }
4429 
4430 static DecodeStatus DecodeThumbCPS(MCInst &Inst, uint16_t Insn,
4431                            uint64_t Address, const void *Decoder) {
4432   unsigned imod = fieldFromInstruction(Insn, 4, 1) | 0x2;
4433   unsigned flags = fieldFromInstruction(Insn, 0, 3);
4434 
4435   Inst.addOperand(MCOperand::createImm(imod));
4436   Inst.addOperand(MCOperand::createImm(flags));
4437 
4438   return MCDisassembler::Success;
4439 }
4440 
4441 static DecodeStatus DecodePostIdxReg(MCInst &Inst, unsigned Insn,
4442                              uint64_t Address, const void *Decoder) {
4443   DecodeStatus S = MCDisassembler::Success;
4444   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4445   unsigned add = fieldFromInstruction(Insn, 4, 1);
4446 
4447   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
4448     return MCDisassembler::Fail;
4449   Inst.addOperand(MCOperand::createImm(add));
4450 
4451   return S;
4452 }
4453 
4454 static DecodeStatus DecodeMveAddrModeRQ(MCInst &Inst, unsigned Insn,
4455                              uint64_t Address, const void *Decoder) {
4456   DecodeStatus S = MCDisassembler::Success;
4457   unsigned Rn = fieldFromInstruction(Insn, 3, 4);
4458   unsigned Qm = fieldFromInstruction(Insn, 0, 3);
4459 
4460   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
4461     return MCDisassembler::Fail;
4462   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
4463     return MCDisassembler::Fail;
4464 
4465   return S;
4466 }
4467 
4468 template<int shift>
4469 static DecodeStatus DecodeMveAddrModeQ(MCInst &Inst, unsigned Insn,
4470                              uint64_t Address, const void *Decoder) {
4471   DecodeStatus S = MCDisassembler::Success;
4472   unsigned Qm = fieldFromInstruction(Insn, 8, 3);
4473   int imm = fieldFromInstruction(Insn, 0, 7);
4474 
4475   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
4476     return MCDisassembler::Fail;
4477 
4478   if(!fieldFromInstruction(Insn, 7, 1)) {
4479     if (imm == 0)
4480       imm = INT32_MIN;                 // indicate -0
4481     else
4482       imm *= -1;
4483   }
4484   if (imm != INT32_MIN)
4485     imm *= (1U << shift);
4486   Inst.addOperand(MCOperand::createImm(imm));
4487 
4488   return S;
4489 }
4490 
4491 static DecodeStatus DecodeThumbBLXOffset(MCInst &Inst, unsigned Val,
4492                                  uint64_t Address, const void *Decoder) {
4493   // Val is passed in as S:J1:J2:imm10H:imm10L:'0'
4494   // Note only one trailing zero not two.  Also the J1 and J2 values are from
4495   // the encoded instruction.  So here change to I1 and I2 values via:
4496   // I1 = NOT(J1 EOR S);
4497   // I2 = NOT(J2 EOR S);
4498   // and build the imm32 with two trailing zeros as documented:
4499   // imm32 = SignExtend(S:I1:I2:imm10H:imm10L:'00', 32);
4500   unsigned S = (Val >> 23) & 1;
4501   unsigned J1 = (Val >> 22) & 1;
4502   unsigned J2 = (Val >> 21) & 1;
4503   unsigned I1 = !(J1 ^ S);
4504   unsigned I2 = !(J2 ^ S);
4505   unsigned tmp = (Val & ~0x600000) | (I1 << 22) | (I2 << 21);
4506   int imm32 = SignExtend32<25>(tmp << 1);
4507 
4508   if (!tryAddingSymbolicOperand(Address,
4509                                 (Address & ~2u) + imm32 + 4,
4510                                 true, 4, Inst, Decoder))
4511     Inst.addOperand(MCOperand::createImm(imm32));
4512   return MCDisassembler::Success;
4513 }
4514 
4515 static DecodeStatus DecodeCoprocessor(MCInst &Inst, unsigned Val,
4516                               uint64_t Address, const void *Decoder) {
4517   if (Val == 0xA || Val == 0xB)
4518     return MCDisassembler::Fail;
4519 
4520   const FeatureBitset &featureBits =
4521     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4522 
4523   if (!isValidCoprocessorNumber(Val, featureBits))
4524     return MCDisassembler::Fail;
4525 
4526   Inst.addOperand(MCOperand::createImm(Val));
4527   return MCDisassembler::Success;
4528 }
4529 
4530 static DecodeStatus
4531 DecodeThumbTableBranch(MCInst &Inst, unsigned Insn,
4532                        uint64_t Address, const void *Decoder) {
4533   const FeatureBitset &FeatureBits =
4534     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4535   DecodeStatus S = MCDisassembler::Success;
4536 
4537   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4538   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4539 
4540   if (Rn == 13 && !FeatureBits[ARM::HasV8Ops]) S = MCDisassembler::SoftFail;
4541   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4542     return MCDisassembler::Fail;
4543   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
4544     return MCDisassembler::Fail;
4545   return S;
4546 }
4547 
4548 static DecodeStatus
4549 DecodeThumb2BCCInstruction(MCInst &Inst, unsigned Insn,
4550                            uint64_t Address, const void *Decoder) {
4551   DecodeStatus S = MCDisassembler::Success;
4552 
4553   unsigned pred = fieldFromInstruction(Insn, 22, 4);
4554   if (pred == 0xE || pred == 0xF) {
4555     unsigned opc = fieldFromInstruction(Insn, 4, 28);
4556     switch (opc) {
4557       default:
4558         return MCDisassembler::Fail;
4559       case 0xf3bf8f4:
4560         Inst.setOpcode(ARM::t2DSB);
4561         break;
4562       case 0xf3bf8f5:
4563         Inst.setOpcode(ARM::t2DMB);
4564         break;
4565       case 0xf3bf8f6:
4566         Inst.setOpcode(ARM::t2ISB);
4567         break;
4568     }
4569 
4570     unsigned imm = fieldFromInstruction(Insn, 0, 4);
4571     return DecodeMemBarrierOption(Inst, imm, Address, Decoder);
4572   }
4573 
4574   unsigned brtarget = fieldFromInstruction(Insn, 0, 11) << 1;
4575   brtarget |= fieldFromInstruction(Insn, 11, 1) << 19;
4576   brtarget |= fieldFromInstruction(Insn, 13, 1) << 18;
4577   brtarget |= fieldFromInstruction(Insn, 16, 6) << 12;
4578   brtarget |= fieldFromInstruction(Insn, 26, 1) << 20;
4579 
4580   if (!Check(S, DecodeT2BROperand(Inst, brtarget, Address, Decoder)))
4581     return MCDisassembler::Fail;
4582   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4583     return MCDisassembler::Fail;
4584 
4585   return S;
4586 }
4587 
4588 // Decode a shifted immediate operand.  These basically consist
4589 // of an 8-bit value, and a 4-bit directive that specifies either
4590 // a splat operation or a rotation.
4591 static DecodeStatus DecodeT2SOImm(MCInst &Inst, unsigned Val,
4592                           uint64_t Address, const void *Decoder) {
4593   unsigned ctrl = fieldFromInstruction(Val, 10, 2);
4594   if (ctrl == 0) {
4595     unsigned byte = fieldFromInstruction(Val, 8, 2);
4596     unsigned imm = fieldFromInstruction(Val, 0, 8);
4597     switch (byte) {
4598       case 0:
4599         Inst.addOperand(MCOperand::createImm(imm));
4600         break;
4601       case 1:
4602         Inst.addOperand(MCOperand::createImm((imm << 16) | imm));
4603         break;
4604       case 2:
4605         Inst.addOperand(MCOperand::createImm((imm << 24) | (imm << 8)));
4606         break;
4607       case 3:
4608         Inst.addOperand(MCOperand::createImm((imm << 24) | (imm << 16) |
4609                                              (imm << 8)  |  imm));
4610         break;
4611     }
4612   } else {
4613     unsigned unrot = fieldFromInstruction(Val, 0, 7) | 0x80;
4614     unsigned rot = fieldFromInstruction(Val, 7, 5);
4615     unsigned imm = (unrot >> rot) | (unrot << ((32-rot)&31));
4616     Inst.addOperand(MCOperand::createImm(imm));
4617   }
4618 
4619   return MCDisassembler::Success;
4620 }
4621 
4622 static DecodeStatus
4623 DecodeThumbBCCTargetOperand(MCInst &Inst, unsigned Val,
4624                             uint64_t Address, const void *Decoder) {
4625   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<9>(Val<<1) + 4,
4626                                 true, 2, Inst, Decoder))
4627     Inst.addOperand(MCOperand::createImm(SignExtend32<9>(Val << 1)));
4628   return MCDisassembler::Success;
4629 }
4630 
4631 static DecodeStatus DecodeThumbBLTargetOperand(MCInst &Inst, unsigned Val,
4632                                                uint64_t Address,
4633                                                const void *Decoder) {
4634   // Val is passed in as S:J1:J2:imm10:imm11
4635   // Note no trailing zero after imm11.  Also the J1 and J2 values are from
4636   // the encoded instruction.  So here change to I1 and I2 values via:
4637   // I1 = NOT(J1 EOR S);
4638   // I2 = NOT(J2 EOR S);
4639   // and build the imm32 with one trailing zero as documented:
4640   // imm32 = SignExtend(S:I1:I2:imm10:imm11:'0', 32);
4641   unsigned S = (Val >> 23) & 1;
4642   unsigned J1 = (Val >> 22) & 1;
4643   unsigned J2 = (Val >> 21) & 1;
4644   unsigned I1 = !(J1 ^ S);
4645   unsigned I2 = !(J2 ^ S);
4646   unsigned tmp = (Val & ~0x600000) | (I1 << 22) | (I2 << 21);
4647   int imm32 = SignExtend32<25>(tmp << 1);
4648 
4649   if (!tryAddingSymbolicOperand(Address, Address + imm32 + 4,
4650                                 true, 4, Inst, Decoder))
4651     Inst.addOperand(MCOperand::createImm(imm32));
4652   return MCDisassembler::Success;
4653 }
4654 
4655 static DecodeStatus DecodeMemBarrierOption(MCInst &Inst, unsigned Val,
4656                                    uint64_t Address, const void *Decoder) {
4657   if (Val & ~0xf)
4658     return MCDisassembler::Fail;
4659 
4660   Inst.addOperand(MCOperand::createImm(Val));
4661   return MCDisassembler::Success;
4662 }
4663 
4664 static DecodeStatus DecodeInstSyncBarrierOption(MCInst &Inst, unsigned Val,
4665                                         uint64_t Address, const void *Decoder) {
4666   if (Val & ~0xf)
4667     return MCDisassembler::Fail;
4668 
4669   Inst.addOperand(MCOperand::createImm(Val));
4670   return MCDisassembler::Success;
4671 }
4672 
4673 static DecodeStatus DecodeMSRMask(MCInst &Inst, unsigned Val,
4674                           uint64_t Address, const void *Decoder) {
4675   DecodeStatus S = MCDisassembler::Success;
4676   const FeatureBitset &FeatureBits =
4677     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4678 
4679   if (FeatureBits[ARM::FeatureMClass]) {
4680     unsigned ValLow = Val & 0xff;
4681 
4682     // Validate the SYSm value first.
4683     switch (ValLow) {
4684     case  0: // apsr
4685     case  1: // iapsr
4686     case  2: // eapsr
4687     case  3: // xpsr
4688     case  5: // ipsr
4689     case  6: // epsr
4690     case  7: // iepsr
4691     case  8: // msp
4692     case  9: // psp
4693     case 16: // primask
4694     case 20: // control
4695       break;
4696     case 17: // basepri
4697     case 18: // basepri_max
4698     case 19: // faultmask
4699       if (!(FeatureBits[ARM::HasV7Ops]))
4700         // Values basepri, basepri_max and faultmask are only valid for v7m.
4701         return MCDisassembler::Fail;
4702       break;
4703     case 0x8a: // msplim_ns
4704     case 0x8b: // psplim_ns
4705     case 0x91: // basepri_ns
4706     case 0x93: // faultmask_ns
4707       if (!(FeatureBits[ARM::HasV8MMainlineOps]))
4708         return MCDisassembler::Fail;
4709       LLVM_FALLTHROUGH;
4710     case 10:   // msplim
4711     case 11:   // psplim
4712     case 0x88: // msp_ns
4713     case 0x89: // psp_ns
4714     case 0x90: // primask_ns
4715     case 0x94: // control_ns
4716     case 0x98: // sp_ns
4717       if (!(FeatureBits[ARM::Feature8MSecExt]))
4718         return MCDisassembler::Fail;
4719       break;
4720     default:
4721       // Architecturally defined as unpredictable
4722       S = MCDisassembler::SoftFail;
4723       break;
4724     }
4725 
4726     if (Inst.getOpcode() == ARM::t2MSR_M) {
4727       unsigned Mask = fieldFromInstruction(Val, 10, 2);
4728       if (!(FeatureBits[ARM::HasV7Ops])) {
4729         // The ARMv6-M MSR bits {11-10} can be only 0b10, other values are
4730         // unpredictable.
4731         if (Mask != 2)
4732           S = MCDisassembler::SoftFail;
4733       }
4734       else {
4735         // The ARMv7-M architecture stores an additional 2-bit mask value in
4736         // MSR bits {11-10}. The mask is used only with apsr, iapsr, eapsr and
4737         // xpsr, it has to be 0b10 in other cases. Bit mask{1} indicates if
4738         // the NZCVQ bits should be moved by the instruction. Bit mask{0}
4739         // indicates the move for the GE{3:0} bits, the mask{0} bit can be set
4740         // only if the processor includes the DSP extension.
4741         if (Mask == 0 || (Mask != 2 && ValLow > 3) ||
4742             (!(FeatureBits[ARM::FeatureDSP]) && (Mask & 1)))
4743           S = MCDisassembler::SoftFail;
4744       }
4745     }
4746   } else {
4747     // A/R class
4748     if (Val == 0)
4749       return MCDisassembler::Fail;
4750   }
4751   Inst.addOperand(MCOperand::createImm(Val));
4752   return S;
4753 }
4754 
4755 static DecodeStatus DecodeBankedReg(MCInst &Inst, unsigned Val,
4756                                     uint64_t Address, const void *Decoder) {
4757   unsigned R = fieldFromInstruction(Val, 5, 1);
4758   unsigned SysM = fieldFromInstruction(Val, 0, 5);
4759 
4760   // The table of encodings for these banked registers comes from B9.2.3 of the
4761   // ARM ARM. There are patterns, but nothing regular enough to make this logic
4762   // neater. So by fiat, these values are UNPREDICTABLE:
4763   if (!ARMBankedReg::lookupBankedRegByEncoding((R << 5) | SysM))
4764     return MCDisassembler::Fail;
4765 
4766   Inst.addOperand(MCOperand::createImm(Val));
4767   return MCDisassembler::Success;
4768 }
4769 
4770 static DecodeStatus DecodeDoubleRegLoad(MCInst &Inst, unsigned Insn,
4771                                         uint64_t Address, const void *Decoder) {
4772   DecodeStatus S = MCDisassembler::Success;
4773 
4774   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4775   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4776   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4777 
4778   if (Rn == 0xF)
4779     S = MCDisassembler::SoftFail;
4780 
4781   if (!Check(S, DecodeGPRPairRegisterClass(Inst, Rt, Address, Decoder)))
4782     return MCDisassembler::Fail;
4783   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4784     return MCDisassembler::Fail;
4785   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4786     return MCDisassembler::Fail;
4787 
4788   return S;
4789 }
4790 
4791 static DecodeStatus DecodeDoubleRegStore(MCInst &Inst, unsigned Insn,
4792                                          uint64_t Address,
4793                                          const void *Decoder) {
4794   DecodeStatus S = MCDisassembler::Success;
4795 
4796   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4797   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
4798   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4799   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4800 
4801   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
4802     return MCDisassembler::Fail;
4803 
4804   if (Rn == 0xF || Rd == Rn || Rd == Rt || Rd == Rt+1)
4805     S = MCDisassembler::SoftFail;
4806 
4807   if (!Check(S, DecodeGPRPairRegisterClass(Inst, Rt, Address, Decoder)))
4808     return MCDisassembler::Fail;
4809   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4810     return MCDisassembler::Fail;
4811   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4812     return MCDisassembler::Fail;
4813 
4814   return S;
4815 }
4816 
4817 static DecodeStatus DecodeLDRPreImm(MCInst &Inst, unsigned Insn,
4818                             uint64_t Address, const void *Decoder) {
4819   DecodeStatus S = MCDisassembler::Success;
4820 
4821   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4822   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4823   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4824   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4825   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4826   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4827 
4828   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4829 
4830   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4831     return MCDisassembler::Fail;
4832   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4833     return MCDisassembler::Fail;
4834   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
4835     return MCDisassembler::Fail;
4836   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4837     return MCDisassembler::Fail;
4838 
4839   return S;
4840 }
4841 
4842 static DecodeStatus DecodeLDRPreReg(MCInst &Inst, unsigned Insn,
4843                             uint64_t Address, const void *Decoder) {
4844   DecodeStatus S = MCDisassembler::Success;
4845 
4846   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4847   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4848   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4849   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4850   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4851   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4852   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4853 
4854   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4855   if (Rm == 0xF) S = MCDisassembler::SoftFail;
4856 
4857   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4858     return MCDisassembler::Fail;
4859   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4860     return MCDisassembler::Fail;
4861   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
4862     return MCDisassembler::Fail;
4863   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4864     return MCDisassembler::Fail;
4865 
4866   return S;
4867 }
4868 
4869 static DecodeStatus DecodeSTRPreImm(MCInst &Inst, unsigned Insn,
4870                             uint64_t Address, const void *Decoder) {
4871   DecodeStatus S = MCDisassembler::Success;
4872 
4873   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4874   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4875   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4876   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4877   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4878   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4879 
4880   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4881 
4882   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4883     return MCDisassembler::Fail;
4884   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4885     return MCDisassembler::Fail;
4886   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
4887     return MCDisassembler::Fail;
4888   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4889     return MCDisassembler::Fail;
4890 
4891   return S;
4892 }
4893 
4894 static DecodeStatus DecodeSTRPreReg(MCInst &Inst, unsigned Insn,
4895                             uint64_t Address, const void *Decoder) {
4896   DecodeStatus S = MCDisassembler::Success;
4897 
4898   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4899   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4900   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4901   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4902   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4903   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4904 
4905   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4906 
4907   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4908     return MCDisassembler::Fail;
4909   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4910     return MCDisassembler::Fail;
4911   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
4912     return MCDisassembler::Fail;
4913   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4914     return MCDisassembler::Fail;
4915 
4916   return S;
4917 }
4918 
4919 static DecodeStatus DecodeVLD1LN(MCInst &Inst, unsigned Insn,
4920                          uint64_t Address, const void *Decoder) {
4921   DecodeStatus S = MCDisassembler::Success;
4922 
4923   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4924   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4925   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4926   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4927   unsigned size = fieldFromInstruction(Insn, 10, 2);
4928 
4929   unsigned align = 0;
4930   unsigned index = 0;
4931   switch (size) {
4932     default:
4933       return MCDisassembler::Fail;
4934     case 0:
4935       if (fieldFromInstruction(Insn, 4, 1))
4936         return MCDisassembler::Fail; // UNDEFINED
4937       index = fieldFromInstruction(Insn, 5, 3);
4938       break;
4939     case 1:
4940       if (fieldFromInstruction(Insn, 5, 1))
4941         return MCDisassembler::Fail; // UNDEFINED
4942       index = fieldFromInstruction(Insn, 6, 2);
4943       if (fieldFromInstruction(Insn, 4, 1))
4944         align = 2;
4945       break;
4946     case 2:
4947       if (fieldFromInstruction(Insn, 6, 1))
4948         return MCDisassembler::Fail; // UNDEFINED
4949       index = fieldFromInstruction(Insn, 7, 1);
4950 
4951       switch (fieldFromInstruction(Insn, 4, 2)) {
4952         case 0 :
4953           align = 0; break;
4954         case 3:
4955           align = 4; break;
4956         default:
4957           return MCDisassembler::Fail;
4958       }
4959       break;
4960   }
4961 
4962   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4963     return MCDisassembler::Fail;
4964   if (Rm != 0xF) { // Writeback
4965     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4966       return MCDisassembler::Fail;
4967   }
4968   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4969     return MCDisassembler::Fail;
4970   Inst.addOperand(MCOperand::createImm(align));
4971   if (Rm != 0xF) {
4972     if (Rm != 0xD) {
4973       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4974         return MCDisassembler::Fail;
4975     } else
4976       Inst.addOperand(MCOperand::createReg(0));
4977   }
4978 
4979   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4980     return MCDisassembler::Fail;
4981   Inst.addOperand(MCOperand::createImm(index));
4982 
4983   return S;
4984 }
4985 
4986 static DecodeStatus DecodeVST1LN(MCInst &Inst, unsigned Insn,
4987                          uint64_t Address, const void *Decoder) {
4988   DecodeStatus S = MCDisassembler::Success;
4989 
4990   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4991   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4992   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4993   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4994   unsigned size = fieldFromInstruction(Insn, 10, 2);
4995 
4996   unsigned align = 0;
4997   unsigned index = 0;
4998   switch (size) {
4999     default:
5000       return MCDisassembler::Fail;
5001     case 0:
5002       if (fieldFromInstruction(Insn, 4, 1))
5003         return MCDisassembler::Fail; // UNDEFINED
5004       index = fieldFromInstruction(Insn, 5, 3);
5005       break;
5006     case 1:
5007       if (fieldFromInstruction(Insn, 5, 1))
5008         return MCDisassembler::Fail; // UNDEFINED
5009       index = fieldFromInstruction(Insn, 6, 2);
5010       if (fieldFromInstruction(Insn, 4, 1))
5011         align = 2;
5012       break;
5013     case 2:
5014       if (fieldFromInstruction(Insn, 6, 1))
5015         return MCDisassembler::Fail; // UNDEFINED
5016       index = fieldFromInstruction(Insn, 7, 1);
5017 
5018       switch (fieldFromInstruction(Insn, 4, 2)) {
5019         case 0:
5020           align = 0; break;
5021         case 3:
5022           align = 4; break;
5023         default:
5024           return MCDisassembler::Fail;
5025       }
5026       break;
5027   }
5028 
5029   if (Rm != 0xF) { // Writeback
5030     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5031     return MCDisassembler::Fail;
5032   }
5033   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5034     return MCDisassembler::Fail;
5035   Inst.addOperand(MCOperand::createImm(align));
5036   if (Rm != 0xF) {
5037     if (Rm != 0xD) {
5038       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5039     return MCDisassembler::Fail;
5040     } else
5041       Inst.addOperand(MCOperand::createReg(0));
5042   }
5043 
5044   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5045     return MCDisassembler::Fail;
5046   Inst.addOperand(MCOperand::createImm(index));
5047 
5048   return S;
5049 }
5050 
5051 static DecodeStatus DecodeVLD2LN(MCInst &Inst, unsigned Insn,
5052                          uint64_t Address, const void *Decoder) {
5053   DecodeStatus S = MCDisassembler::Success;
5054 
5055   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5056   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5057   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5058   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5059   unsigned size = fieldFromInstruction(Insn, 10, 2);
5060 
5061   unsigned align = 0;
5062   unsigned index = 0;
5063   unsigned inc = 1;
5064   switch (size) {
5065     default:
5066       return MCDisassembler::Fail;
5067     case 0:
5068       index = fieldFromInstruction(Insn, 5, 3);
5069       if (fieldFromInstruction(Insn, 4, 1))
5070         align = 2;
5071       break;
5072     case 1:
5073       index = fieldFromInstruction(Insn, 6, 2);
5074       if (fieldFromInstruction(Insn, 4, 1))
5075         align = 4;
5076       if (fieldFromInstruction(Insn, 5, 1))
5077         inc = 2;
5078       break;
5079     case 2:
5080       if (fieldFromInstruction(Insn, 5, 1))
5081         return MCDisassembler::Fail; // UNDEFINED
5082       index = fieldFromInstruction(Insn, 7, 1);
5083       if (fieldFromInstruction(Insn, 4, 1) != 0)
5084         align = 8;
5085       if (fieldFromInstruction(Insn, 6, 1))
5086         inc = 2;
5087       break;
5088   }
5089 
5090   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5091     return MCDisassembler::Fail;
5092   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5093     return MCDisassembler::Fail;
5094   if (Rm != 0xF) { // Writeback
5095     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5096       return MCDisassembler::Fail;
5097   }
5098   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5099     return MCDisassembler::Fail;
5100   Inst.addOperand(MCOperand::createImm(align));
5101   if (Rm != 0xF) {
5102     if (Rm != 0xD) {
5103       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5104         return MCDisassembler::Fail;
5105     } else
5106       Inst.addOperand(MCOperand::createReg(0));
5107   }
5108 
5109   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5110     return MCDisassembler::Fail;
5111   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5112     return MCDisassembler::Fail;
5113   Inst.addOperand(MCOperand::createImm(index));
5114 
5115   return S;
5116 }
5117 
5118 static DecodeStatus DecodeVST2LN(MCInst &Inst, unsigned Insn,
5119                          uint64_t Address, const void *Decoder) {
5120   DecodeStatus S = MCDisassembler::Success;
5121 
5122   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5123   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5124   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5125   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5126   unsigned size = fieldFromInstruction(Insn, 10, 2);
5127 
5128   unsigned align = 0;
5129   unsigned index = 0;
5130   unsigned inc = 1;
5131   switch (size) {
5132     default:
5133       return MCDisassembler::Fail;
5134     case 0:
5135       index = fieldFromInstruction(Insn, 5, 3);
5136       if (fieldFromInstruction(Insn, 4, 1))
5137         align = 2;
5138       break;
5139     case 1:
5140       index = fieldFromInstruction(Insn, 6, 2);
5141       if (fieldFromInstruction(Insn, 4, 1))
5142         align = 4;
5143       if (fieldFromInstruction(Insn, 5, 1))
5144         inc = 2;
5145       break;
5146     case 2:
5147       if (fieldFromInstruction(Insn, 5, 1))
5148         return MCDisassembler::Fail; // UNDEFINED
5149       index = fieldFromInstruction(Insn, 7, 1);
5150       if (fieldFromInstruction(Insn, 4, 1) != 0)
5151         align = 8;
5152       if (fieldFromInstruction(Insn, 6, 1))
5153         inc = 2;
5154       break;
5155   }
5156 
5157   if (Rm != 0xF) { // Writeback
5158     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5159       return MCDisassembler::Fail;
5160   }
5161   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5162     return MCDisassembler::Fail;
5163   Inst.addOperand(MCOperand::createImm(align));
5164   if (Rm != 0xF) {
5165     if (Rm != 0xD) {
5166       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5167         return MCDisassembler::Fail;
5168     } else
5169       Inst.addOperand(MCOperand::createReg(0));
5170   }
5171 
5172   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5173     return MCDisassembler::Fail;
5174   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5175     return MCDisassembler::Fail;
5176   Inst.addOperand(MCOperand::createImm(index));
5177 
5178   return S;
5179 }
5180 
5181 static DecodeStatus DecodeVLD3LN(MCInst &Inst, unsigned Insn,
5182                          uint64_t Address, const void *Decoder) {
5183   DecodeStatus S = MCDisassembler::Success;
5184 
5185   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5186   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5187   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5188   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5189   unsigned size = fieldFromInstruction(Insn, 10, 2);
5190 
5191   unsigned align = 0;
5192   unsigned index = 0;
5193   unsigned inc = 1;
5194   switch (size) {
5195     default:
5196       return MCDisassembler::Fail;
5197     case 0:
5198       if (fieldFromInstruction(Insn, 4, 1))
5199         return MCDisassembler::Fail; // UNDEFINED
5200       index = fieldFromInstruction(Insn, 5, 3);
5201       break;
5202     case 1:
5203       if (fieldFromInstruction(Insn, 4, 1))
5204         return MCDisassembler::Fail; // UNDEFINED
5205       index = fieldFromInstruction(Insn, 6, 2);
5206       if (fieldFromInstruction(Insn, 5, 1))
5207         inc = 2;
5208       break;
5209     case 2:
5210       if (fieldFromInstruction(Insn, 4, 2))
5211         return MCDisassembler::Fail; // UNDEFINED
5212       index = fieldFromInstruction(Insn, 7, 1);
5213       if (fieldFromInstruction(Insn, 6, 1))
5214         inc = 2;
5215       break;
5216   }
5217 
5218   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5219     return MCDisassembler::Fail;
5220   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5221     return MCDisassembler::Fail;
5222   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5223     return MCDisassembler::Fail;
5224 
5225   if (Rm != 0xF) { // Writeback
5226     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5227     return MCDisassembler::Fail;
5228   }
5229   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5230     return MCDisassembler::Fail;
5231   Inst.addOperand(MCOperand::createImm(align));
5232   if (Rm != 0xF) {
5233     if (Rm != 0xD) {
5234       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5235     return MCDisassembler::Fail;
5236     } else
5237       Inst.addOperand(MCOperand::createReg(0));
5238   }
5239 
5240   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5241     return MCDisassembler::Fail;
5242   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5243     return MCDisassembler::Fail;
5244   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5245     return MCDisassembler::Fail;
5246   Inst.addOperand(MCOperand::createImm(index));
5247 
5248   return S;
5249 }
5250 
5251 static DecodeStatus DecodeVST3LN(MCInst &Inst, unsigned Insn,
5252                          uint64_t Address, const void *Decoder) {
5253   DecodeStatus S = MCDisassembler::Success;
5254 
5255   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5256   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5257   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5258   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5259   unsigned size = fieldFromInstruction(Insn, 10, 2);
5260 
5261   unsigned align = 0;
5262   unsigned index = 0;
5263   unsigned inc = 1;
5264   switch (size) {
5265     default:
5266       return MCDisassembler::Fail;
5267     case 0:
5268       if (fieldFromInstruction(Insn, 4, 1))
5269         return MCDisassembler::Fail; // UNDEFINED
5270       index = fieldFromInstruction(Insn, 5, 3);
5271       break;
5272     case 1:
5273       if (fieldFromInstruction(Insn, 4, 1))
5274         return MCDisassembler::Fail; // UNDEFINED
5275       index = fieldFromInstruction(Insn, 6, 2);
5276       if (fieldFromInstruction(Insn, 5, 1))
5277         inc = 2;
5278       break;
5279     case 2:
5280       if (fieldFromInstruction(Insn, 4, 2))
5281         return MCDisassembler::Fail; // UNDEFINED
5282       index = fieldFromInstruction(Insn, 7, 1);
5283       if (fieldFromInstruction(Insn, 6, 1))
5284         inc = 2;
5285       break;
5286   }
5287 
5288   if (Rm != 0xF) { // Writeback
5289     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5290     return MCDisassembler::Fail;
5291   }
5292   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5293     return MCDisassembler::Fail;
5294   Inst.addOperand(MCOperand::createImm(align));
5295   if (Rm != 0xF) {
5296     if (Rm != 0xD) {
5297       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5298     return MCDisassembler::Fail;
5299     } else
5300       Inst.addOperand(MCOperand::createReg(0));
5301   }
5302 
5303   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5304     return MCDisassembler::Fail;
5305   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5306     return MCDisassembler::Fail;
5307   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5308     return MCDisassembler::Fail;
5309   Inst.addOperand(MCOperand::createImm(index));
5310 
5311   return S;
5312 }
5313 
5314 static DecodeStatus DecodeVLD4LN(MCInst &Inst, unsigned Insn,
5315                          uint64_t Address, const void *Decoder) {
5316   DecodeStatus S = MCDisassembler::Success;
5317 
5318   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5319   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5320   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5321   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5322   unsigned size = fieldFromInstruction(Insn, 10, 2);
5323 
5324   unsigned align = 0;
5325   unsigned index = 0;
5326   unsigned inc = 1;
5327   switch (size) {
5328     default:
5329       return MCDisassembler::Fail;
5330     case 0:
5331       if (fieldFromInstruction(Insn, 4, 1))
5332         align = 4;
5333       index = fieldFromInstruction(Insn, 5, 3);
5334       break;
5335     case 1:
5336       if (fieldFromInstruction(Insn, 4, 1))
5337         align = 8;
5338       index = fieldFromInstruction(Insn, 6, 2);
5339       if (fieldFromInstruction(Insn, 5, 1))
5340         inc = 2;
5341       break;
5342     case 2:
5343       switch (fieldFromInstruction(Insn, 4, 2)) {
5344         case 0:
5345           align = 0; break;
5346         case 3:
5347           return MCDisassembler::Fail;
5348         default:
5349           align = 4 << fieldFromInstruction(Insn, 4, 2); break;
5350       }
5351 
5352       index = fieldFromInstruction(Insn, 7, 1);
5353       if (fieldFromInstruction(Insn, 6, 1))
5354         inc = 2;
5355       break;
5356   }
5357 
5358   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5359     return MCDisassembler::Fail;
5360   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5361     return MCDisassembler::Fail;
5362   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5363     return MCDisassembler::Fail;
5364   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5365     return MCDisassembler::Fail;
5366 
5367   if (Rm != 0xF) { // Writeback
5368     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5369       return MCDisassembler::Fail;
5370   }
5371   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5372     return MCDisassembler::Fail;
5373   Inst.addOperand(MCOperand::createImm(align));
5374   if (Rm != 0xF) {
5375     if (Rm != 0xD) {
5376       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5377         return MCDisassembler::Fail;
5378     } else
5379       Inst.addOperand(MCOperand::createReg(0));
5380   }
5381 
5382   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5383     return MCDisassembler::Fail;
5384   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5385     return MCDisassembler::Fail;
5386   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5387     return MCDisassembler::Fail;
5388   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5389     return MCDisassembler::Fail;
5390   Inst.addOperand(MCOperand::createImm(index));
5391 
5392   return S;
5393 }
5394 
5395 static DecodeStatus DecodeVST4LN(MCInst &Inst, unsigned Insn,
5396                          uint64_t Address, const void *Decoder) {
5397   DecodeStatus S = MCDisassembler::Success;
5398 
5399   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5400   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5401   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5402   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5403   unsigned size = fieldFromInstruction(Insn, 10, 2);
5404 
5405   unsigned align = 0;
5406   unsigned index = 0;
5407   unsigned inc = 1;
5408   switch (size) {
5409     default:
5410       return MCDisassembler::Fail;
5411     case 0:
5412       if (fieldFromInstruction(Insn, 4, 1))
5413         align = 4;
5414       index = fieldFromInstruction(Insn, 5, 3);
5415       break;
5416     case 1:
5417       if (fieldFromInstruction(Insn, 4, 1))
5418         align = 8;
5419       index = fieldFromInstruction(Insn, 6, 2);
5420       if (fieldFromInstruction(Insn, 5, 1))
5421         inc = 2;
5422       break;
5423     case 2:
5424       switch (fieldFromInstruction(Insn, 4, 2)) {
5425         case 0:
5426           align = 0; break;
5427         case 3:
5428           return MCDisassembler::Fail;
5429         default:
5430           align = 4 << fieldFromInstruction(Insn, 4, 2); break;
5431       }
5432 
5433       index = fieldFromInstruction(Insn, 7, 1);
5434       if (fieldFromInstruction(Insn, 6, 1))
5435         inc = 2;
5436       break;
5437   }
5438 
5439   if (Rm != 0xF) { // Writeback
5440     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5441     return MCDisassembler::Fail;
5442   }
5443   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5444     return MCDisassembler::Fail;
5445   Inst.addOperand(MCOperand::createImm(align));
5446   if (Rm != 0xF) {
5447     if (Rm != 0xD) {
5448       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5449     return MCDisassembler::Fail;
5450     } else
5451       Inst.addOperand(MCOperand::createReg(0));
5452   }
5453 
5454   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5455     return MCDisassembler::Fail;
5456   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5457     return MCDisassembler::Fail;
5458   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5459     return MCDisassembler::Fail;
5460   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5461     return MCDisassembler::Fail;
5462   Inst.addOperand(MCOperand::createImm(index));
5463 
5464   return S;
5465 }
5466 
5467 static DecodeStatus DecodeVMOVSRR(MCInst &Inst, unsigned Insn,
5468                                   uint64_t Address, const void *Decoder) {
5469   DecodeStatus S = MCDisassembler::Success;
5470   unsigned Rt  = fieldFromInstruction(Insn, 12, 4);
5471   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
5472   unsigned Rm  = fieldFromInstruction(Insn,  5, 1);
5473   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5474   Rm |= fieldFromInstruction(Insn, 0, 4) << 1;
5475 
5476   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
5477     S = MCDisassembler::SoftFail;
5478 
5479   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
5480     return MCDisassembler::Fail;
5481   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
5482     return MCDisassembler::Fail;
5483   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
5484     return MCDisassembler::Fail;
5485   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
5486     return MCDisassembler::Fail;
5487   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5488     return MCDisassembler::Fail;
5489 
5490   return S;
5491 }
5492 
5493 static DecodeStatus DecodeVMOVRRS(MCInst &Inst, unsigned Insn,
5494                                   uint64_t Address, const void *Decoder) {
5495   DecodeStatus S = MCDisassembler::Success;
5496   unsigned Rt  = fieldFromInstruction(Insn, 12, 4);
5497   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
5498   unsigned Rm  = fieldFromInstruction(Insn,  5, 1);
5499   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5500   Rm |= fieldFromInstruction(Insn, 0, 4) << 1;
5501 
5502   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
5503     S = MCDisassembler::SoftFail;
5504 
5505   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
5506     return MCDisassembler::Fail;
5507   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
5508     return MCDisassembler::Fail;
5509   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
5510     return MCDisassembler::Fail;
5511   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
5512     return MCDisassembler::Fail;
5513   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5514     return MCDisassembler::Fail;
5515 
5516   return S;
5517 }
5518 
5519 static DecodeStatus DecodeIT(MCInst &Inst, unsigned Insn,
5520                              uint64_t Address, const void *Decoder) {
5521   DecodeStatus S = MCDisassembler::Success;
5522   unsigned pred = fieldFromInstruction(Insn, 4, 4);
5523   unsigned mask = fieldFromInstruction(Insn, 0, 4);
5524 
5525   if (pred == 0xF) {
5526     pred = 0xE;
5527     S = MCDisassembler::SoftFail;
5528   }
5529 
5530   if (mask == 0x0)
5531     return MCDisassembler::Fail;
5532 
5533   // IT masks are encoded as a sequence of replacement low-order bits
5534   // for the condition code. So if the low bit of the starting
5535   // condition code is 1, then we have to flip all the bits above the
5536   // terminating bit (which is the lowest 1 bit).
5537   if (pred & 1) {
5538     unsigned LowBit = mask & -mask;
5539     unsigned BitsAboveLowBit = 0xF & (-LowBit << 1);
5540     mask ^= BitsAboveLowBit;
5541   }
5542 
5543   Inst.addOperand(MCOperand::createImm(pred));
5544   Inst.addOperand(MCOperand::createImm(mask));
5545   return S;
5546 }
5547 
5548 static DecodeStatus
5549 DecodeT2LDRDPreInstruction(MCInst &Inst, unsigned Insn,
5550                            uint64_t Address, const void *Decoder) {
5551   DecodeStatus S = MCDisassembler::Success;
5552 
5553   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5554   unsigned Rt2 = fieldFromInstruction(Insn, 8, 4);
5555   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5556   unsigned addr = fieldFromInstruction(Insn, 0, 8);
5557   unsigned W = fieldFromInstruction(Insn, 21, 1);
5558   unsigned U = fieldFromInstruction(Insn, 23, 1);
5559   unsigned P = fieldFromInstruction(Insn, 24, 1);
5560   bool writeback = (W == 1) | (P == 0);
5561 
5562   addr |= (U << 8) | (Rn << 9);
5563 
5564   if (writeback && (Rn == Rt || Rn == Rt2))
5565     Check(S, MCDisassembler::SoftFail);
5566   if (Rt == Rt2)
5567     Check(S, MCDisassembler::SoftFail);
5568 
5569   // Rt
5570   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
5571     return MCDisassembler::Fail;
5572   // Rt2
5573   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
5574     return MCDisassembler::Fail;
5575   // Writeback operand
5576   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
5577     return MCDisassembler::Fail;
5578   // addr
5579   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
5580     return MCDisassembler::Fail;
5581 
5582   return S;
5583 }
5584 
5585 static DecodeStatus
5586 DecodeT2STRDPreInstruction(MCInst &Inst, unsigned Insn,
5587                            uint64_t Address, const void *Decoder) {
5588   DecodeStatus S = MCDisassembler::Success;
5589 
5590   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5591   unsigned Rt2 = fieldFromInstruction(Insn, 8, 4);
5592   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5593   unsigned addr = fieldFromInstruction(Insn, 0, 8);
5594   unsigned W = fieldFromInstruction(Insn, 21, 1);
5595   unsigned U = fieldFromInstruction(Insn, 23, 1);
5596   unsigned P = fieldFromInstruction(Insn, 24, 1);
5597   bool writeback = (W == 1) | (P == 0);
5598 
5599   addr |= (U << 8) | (Rn << 9);
5600 
5601   if (writeback && (Rn == Rt || Rn == Rt2))
5602     Check(S, MCDisassembler::SoftFail);
5603 
5604   // Writeback operand
5605   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
5606     return MCDisassembler::Fail;
5607   // Rt
5608   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
5609     return MCDisassembler::Fail;
5610   // Rt2
5611   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
5612     return MCDisassembler::Fail;
5613   // addr
5614   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
5615     return MCDisassembler::Fail;
5616 
5617   return S;
5618 }
5619 
5620 static DecodeStatus DecodeT2Adr(MCInst &Inst, uint32_t Insn,
5621                                 uint64_t Address, const void *Decoder) {
5622   unsigned sign1 = fieldFromInstruction(Insn, 21, 1);
5623   unsigned sign2 = fieldFromInstruction(Insn, 23, 1);
5624   if (sign1 != sign2) return MCDisassembler::Fail;
5625   const unsigned Rd = fieldFromInstruction(Insn, 8, 4);
5626   assert(Inst.getNumOperands() == 0 && "We should receive an empty Inst");
5627   DecodeStatus S = DecoderGPRRegisterClass(Inst, Rd, Address, Decoder);
5628 
5629   unsigned Val = fieldFromInstruction(Insn, 0, 8);
5630   Val |= fieldFromInstruction(Insn, 12, 3) << 8;
5631   Val |= fieldFromInstruction(Insn, 26, 1) << 11;
5632   // If sign, then it is decreasing the address.
5633   if (sign1) {
5634     // Following ARMv7 Architecture Manual, when the offset
5635     // is zero, it is decoded as a subw, not as a adr.w
5636     if (!Val) {
5637       Inst.setOpcode(ARM::t2SUBri12);
5638       Inst.addOperand(MCOperand::createReg(ARM::PC));
5639     } else
5640       Val = -Val;
5641   }
5642   Inst.addOperand(MCOperand::createImm(Val));
5643   return S;
5644 }
5645 
5646 static DecodeStatus DecodeT2ShifterImmOperand(MCInst &Inst, uint32_t Val,
5647                                               uint64_t Address,
5648                                               const void *Decoder) {
5649   DecodeStatus S = MCDisassembler::Success;
5650 
5651   // Shift of "asr #32" is not allowed in Thumb2 mode.
5652   if (Val == 0x20) S = MCDisassembler::Fail;
5653   Inst.addOperand(MCOperand::createImm(Val));
5654   return S;
5655 }
5656 
5657 static DecodeStatus DecodeSwap(MCInst &Inst, unsigned Insn,
5658                                uint64_t Address, const void *Decoder) {
5659   unsigned Rt   = fieldFromInstruction(Insn, 12, 4);
5660   unsigned Rt2  = fieldFromInstruction(Insn, 0,  4);
5661   unsigned Rn   = fieldFromInstruction(Insn, 16, 4);
5662   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5663 
5664   if (pred == 0xF)
5665     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
5666 
5667   DecodeStatus S = MCDisassembler::Success;
5668 
5669   if (Rt == Rn || Rn == Rt2)
5670     S = MCDisassembler::SoftFail;
5671 
5672   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5673     return MCDisassembler::Fail;
5674   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5675     return MCDisassembler::Fail;
5676   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
5677     return MCDisassembler::Fail;
5678   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5679     return MCDisassembler::Fail;
5680 
5681   return S;
5682 }
5683 
5684 static DecodeStatus DecodeVCVTD(MCInst &Inst, unsigned Insn,
5685                                 uint64_t Address, const void *Decoder) {
5686   const FeatureBitset &featureBits =
5687       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5688   bool hasFullFP16 = featureBits[ARM::FeatureFullFP16];
5689 
5690   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5691   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5692   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5693   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5694   unsigned imm = fieldFromInstruction(Insn, 16, 6);
5695   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
5696   unsigned op = fieldFromInstruction(Insn, 5, 1);
5697 
5698   DecodeStatus S = MCDisassembler::Success;
5699 
5700   // If the top 3 bits of imm are clear, this is a VMOV (immediate)
5701   if (!(imm & 0x38)) {
5702     if (cmode == 0xF) {
5703       if (op == 1) return MCDisassembler::Fail;
5704       Inst.setOpcode(ARM::VMOVv2f32);
5705     }
5706     if (hasFullFP16) {
5707       if (cmode == 0xE) {
5708         if (op == 1) {
5709           Inst.setOpcode(ARM::VMOVv1i64);
5710         } else {
5711           Inst.setOpcode(ARM::VMOVv8i8);
5712         }
5713       }
5714       if (cmode == 0xD) {
5715         if (op == 1) {
5716           Inst.setOpcode(ARM::VMVNv2i32);
5717         } else {
5718           Inst.setOpcode(ARM::VMOVv2i32);
5719         }
5720       }
5721       if (cmode == 0xC) {
5722         if (op == 1) {
5723           Inst.setOpcode(ARM::VMVNv2i32);
5724         } else {
5725           Inst.setOpcode(ARM::VMOVv2i32);
5726         }
5727       }
5728     }
5729     return DecodeVMOVModImmInstruction(Inst, Insn, Address, Decoder);
5730   }
5731 
5732   if (!(imm & 0x20)) return MCDisassembler::Fail;
5733 
5734   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
5735     return MCDisassembler::Fail;
5736   if (!Check(S, DecodeDPRRegisterClass(Inst, Vm, Address, Decoder)))
5737     return MCDisassembler::Fail;
5738   Inst.addOperand(MCOperand::createImm(64 - imm));
5739 
5740   return S;
5741 }
5742 
5743 static DecodeStatus DecodeVCVTQ(MCInst &Inst, unsigned Insn,
5744                                 uint64_t Address, const void *Decoder) {
5745   const FeatureBitset &featureBits =
5746       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5747   bool hasFullFP16 = featureBits[ARM::FeatureFullFP16];
5748 
5749   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5750   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5751   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5752   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5753   unsigned imm = fieldFromInstruction(Insn, 16, 6);
5754   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
5755   unsigned op = fieldFromInstruction(Insn, 5, 1);
5756 
5757   DecodeStatus S = MCDisassembler::Success;
5758 
5759   // If the top 3 bits of imm are clear, this is a VMOV (immediate)
5760   if (!(imm & 0x38)) {
5761     if (cmode == 0xF) {
5762       if (op == 1) return MCDisassembler::Fail;
5763       Inst.setOpcode(ARM::VMOVv4f32);
5764     }
5765     if (hasFullFP16) {
5766       if (cmode == 0xE) {
5767         if (op == 1) {
5768           Inst.setOpcode(ARM::VMOVv2i64);
5769         } else {
5770           Inst.setOpcode(ARM::VMOVv16i8);
5771         }
5772       }
5773       if (cmode == 0xD) {
5774         if (op == 1) {
5775           Inst.setOpcode(ARM::VMVNv4i32);
5776         } else {
5777           Inst.setOpcode(ARM::VMOVv4i32);
5778         }
5779       }
5780       if (cmode == 0xC) {
5781         if (op == 1) {
5782           Inst.setOpcode(ARM::VMVNv4i32);
5783         } else {
5784           Inst.setOpcode(ARM::VMOVv4i32);
5785         }
5786       }
5787     }
5788     return DecodeVMOVModImmInstruction(Inst, Insn, Address, Decoder);
5789   }
5790 
5791   if (!(imm & 0x20)) return MCDisassembler::Fail;
5792 
5793   if (!Check(S, DecodeQPRRegisterClass(Inst, Vd, Address, Decoder)))
5794     return MCDisassembler::Fail;
5795   if (!Check(S, DecodeQPRRegisterClass(Inst, Vm, Address, Decoder)))
5796     return MCDisassembler::Fail;
5797   Inst.addOperand(MCOperand::createImm(64 - imm));
5798 
5799   return S;
5800 }
5801 
5802 static DecodeStatus DecodeNEONComplexLane64Instruction(MCInst &Inst,
5803                                                        unsigned Insn,
5804                                                        uint64_t Address,
5805                                                        const void *Decoder) {
5806   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5807   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5808   unsigned Vn = (fieldFromInstruction(Insn, 16, 4) << 0);
5809   Vn |= (fieldFromInstruction(Insn, 7, 1) << 4);
5810   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5811   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5812   unsigned q = (fieldFromInstruction(Insn, 6, 1) << 0);
5813   unsigned rotate = (fieldFromInstruction(Insn, 20, 2) << 0);
5814 
5815   DecodeStatus S = MCDisassembler::Success;
5816 
5817   auto DestRegDecoder = q ? DecodeQPRRegisterClass : DecodeDPRRegisterClass;
5818 
5819   if (!Check(S, DestRegDecoder(Inst, Vd, Address, Decoder)))
5820     return MCDisassembler::Fail;
5821   if (!Check(S, DestRegDecoder(Inst, Vd, Address, Decoder)))
5822     return MCDisassembler::Fail;
5823   if (!Check(S, DestRegDecoder(Inst, Vn, Address, Decoder)))
5824     return MCDisassembler::Fail;
5825   if (!Check(S, DecodeDPRRegisterClass(Inst, Vm, Address, Decoder)))
5826     return MCDisassembler::Fail;
5827   // The lane index does not have any bits in the encoding, because it can only
5828   // be 0.
5829   Inst.addOperand(MCOperand::createImm(0));
5830   Inst.addOperand(MCOperand::createImm(rotate));
5831 
5832   return S;
5833 }
5834 
5835 static DecodeStatus DecodeLDR(MCInst &Inst, unsigned Val,
5836                                 uint64_t Address, const void *Decoder) {
5837   DecodeStatus S = MCDisassembler::Success;
5838 
5839   unsigned Rn = fieldFromInstruction(Val, 16, 4);
5840   unsigned Rt = fieldFromInstruction(Val, 12, 4);
5841   unsigned Rm = fieldFromInstruction(Val, 0, 4);
5842   Rm |= (fieldFromInstruction(Val, 23, 1) << 4);
5843   unsigned Cond = fieldFromInstruction(Val, 28, 4);
5844 
5845   if (fieldFromInstruction(Val, 8, 4) != 0 || Rn == Rt)
5846     S = MCDisassembler::SoftFail;
5847 
5848   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5849     return MCDisassembler::Fail;
5850   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
5851     return MCDisassembler::Fail;
5852   if (!Check(S, DecodeAddrMode7Operand(Inst, Rn, Address, Decoder)))
5853     return MCDisassembler::Fail;
5854   if (!Check(S, DecodePostIdxReg(Inst, Rm, Address, Decoder)))
5855     return MCDisassembler::Fail;
5856   if (!Check(S, DecodePredicateOperand(Inst, Cond, Address, Decoder)))
5857     return MCDisassembler::Fail;
5858 
5859   return S;
5860 }
5861 
5862 static DecodeStatus DecoderForMRRC2AndMCRR2(MCInst &Inst, unsigned Val,
5863                                             uint64_t Address, const void *Decoder) {
5864   DecodeStatus S = MCDisassembler::Success;
5865 
5866   unsigned CRm = fieldFromInstruction(Val, 0, 4);
5867   unsigned opc1 = fieldFromInstruction(Val, 4, 4);
5868   unsigned cop = fieldFromInstruction(Val, 8, 4);
5869   unsigned Rt = fieldFromInstruction(Val, 12, 4);
5870   unsigned Rt2 = fieldFromInstruction(Val, 16, 4);
5871 
5872   if ((cop & ~0x1) == 0xa)
5873     return MCDisassembler::Fail;
5874 
5875   if (Rt == Rt2)
5876     S = MCDisassembler::SoftFail;
5877 
5878   // We have to check if the instruction is MRRC2
5879   // or MCRR2 when constructing the operands for
5880   // Inst. Reason is because MRRC2 stores to two
5881   // registers so it's tablegen desc has has two
5882   // outputs whereas MCRR doesn't store to any
5883   // registers so all of it's operands are listed
5884   // as inputs, therefore the operand order for
5885   // MRRC2 needs to be [Rt, Rt2, cop, opc1, CRm]
5886   // and MCRR2 operand order is [cop, opc1, Rt, Rt2, CRm]
5887 
5888   if (Inst.getOpcode() == ARM::MRRC2) {
5889     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5890       return MCDisassembler::Fail;
5891     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5892       return MCDisassembler::Fail;
5893   }
5894   Inst.addOperand(MCOperand::createImm(cop));
5895   Inst.addOperand(MCOperand::createImm(opc1));
5896   if (Inst.getOpcode() == ARM::MCRR2) {
5897     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5898       return MCDisassembler::Fail;
5899     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5900       return MCDisassembler::Fail;
5901   }
5902   Inst.addOperand(MCOperand::createImm(CRm));
5903 
5904   return S;
5905 }
5906 
5907 static DecodeStatus DecodeForVMRSandVMSR(MCInst &Inst, unsigned Val,
5908                                          uint64_t Address,
5909                                          const void *Decoder) {
5910   const FeatureBitset &featureBits =
5911       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5912   DecodeStatus S = MCDisassembler::Success;
5913 
5914   // Add explicit operand for the destination sysreg, for cases where
5915   // we have to model it for code generation purposes.
5916   switch (Inst.getOpcode()) {
5917   case ARM::VMSR_FPSCR_NZCVQC:
5918     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
5919     break;
5920   case ARM::VMSR_P0:
5921     Inst.addOperand(MCOperand::createReg(ARM::VPR));
5922     break;
5923   }
5924 
5925   if (Inst.getOpcode() != ARM::FMSTAT) {
5926     unsigned Rt = fieldFromInstruction(Val, 12, 4);
5927 
5928     if (featureBits[ARM::ModeThumb] && !featureBits[ARM::HasV8Ops]) {
5929       if (Rt == 13 || Rt == 15)
5930         S = MCDisassembler::SoftFail;
5931       Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder));
5932     } else
5933       Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder));
5934   }
5935 
5936   // Add explicit operand for the source sysreg, similarly to above.
5937   switch (Inst.getOpcode()) {
5938   case ARM::VMRS_FPSCR_NZCVQC:
5939     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
5940     break;
5941   case ARM::VMRS_P0:
5942     Inst.addOperand(MCOperand::createReg(ARM::VPR));
5943     break;
5944   }
5945 
5946   if (featureBits[ARM::ModeThumb]) {
5947     Inst.addOperand(MCOperand::createImm(ARMCC::AL));
5948     Inst.addOperand(MCOperand::createReg(0));
5949   } else {
5950     unsigned pred = fieldFromInstruction(Val, 28, 4);
5951     if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5952       return MCDisassembler::Fail;
5953   }
5954 
5955   return S;
5956 }
5957 
5958 template <bool isSigned, bool isNeg, bool zeroPermitted, int size>
5959 static DecodeStatus DecodeBFLabelOperand(MCInst &Inst, unsigned Val,
5960                                          uint64_t Address,
5961                                          const void *Decoder) {
5962   DecodeStatus S = MCDisassembler::Success;
5963   if (Val == 0 && !zeroPermitted)
5964     S = MCDisassembler::Fail;
5965 
5966   uint64_t DecVal;
5967   if (isSigned)
5968     DecVal = SignExtend32<size + 1>(Val << 1);
5969   else
5970     DecVal = (Val << 1);
5971 
5972   if (!tryAddingSymbolicOperand(Address, Address + DecVal + 4, true, 4, Inst,
5973                                 Decoder))
5974     Inst.addOperand(MCOperand::createImm(isNeg ? -DecVal : DecVal));
5975   return S;
5976 }
5977 
5978 static DecodeStatus DecodeBFAfterTargetOperand(MCInst &Inst, unsigned Val,
5979                                                uint64_t Address,
5980                                                const void *Decoder) {
5981 
5982   uint64_t LocImm = Inst.getOperand(0).getImm();
5983   Val = LocImm + (2 << Val);
5984   if (!tryAddingSymbolicOperand(Address, Address + Val + 4, true, 4, Inst,
5985                                 Decoder))
5986     Inst.addOperand(MCOperand::createImm(Val));
5987   return MCDisassembler::Success;
5988 }
5989 
5990 static DecodeStatus DecodePredNoALOperand(MCInst &Inst, unsigned Val,
5991                                           uint64_t Address,
5992                                           const void *Decoder) {
5993   if (Val >= ARMCC::AL)  // also exclude the non-condition NV
5994     return MCDisassembler::Fail;
5995   Inst.addOperand(MCOperand::createImm(Val));
5996   return MCDisassembler::Success;
5997 }
5998 
5999 static DecodeStatus DecodeLOLoop(MCInst &Inst, unsigned Insn, uint64_t Address,
6000                                  const void *Decoder) {
6001   DecodeStatus S = MCDisassembler::Success;
6002 
6003   if (Inst.getOpcode() == ARM::MVE_LCTP)
6004     return S;
6005 
6006   unsigned Imm = fieldFromInstruction(Insn, 11, 1) |
6007                  fieldFromInstruction(Insn, 1, 10) << 1;
6008   switch (Inst.getOpcode()) {
6009   case ARM::t2LEUpdate:
6010   case ARM::MVE_LETP:
6011     Inst.addOperand(MCOperand::createReg(ARM::LR));
6012     Inst.addOperand(MCOperand::createReg(ARM::LR));
6013     LLVM_FALLTHROUGH;
6014   case ARM::t2LE:
6015     if (!Check(S, DecodeBFLabelOperand<false, true, true, 11>(
6016                    Inst, Imm, Address, Decoder)))
6017       return MCDisassembler::Fail;
6018     break;
6019   case ARM::t2WLS:
6020   case ARM::MVE_WLSTP_8:
6021   case ARM::MVE_WLSTP_16:
6022   case ARM::MVE_WLSTP_32:
6023   case ARM::MVE_WLSTP_64:
6024     Inst.addOperand(MCOperand::createReg(ARM::LR));
6025     if (!Check(S,
6026                DecoderGPRRegisterClass(Inst, fieldFromInstruction(Insn, 16, 4),
6027                                        Address, Decoder)) ||
6028         !Check(S, DecodeBFLabelOperand<false, false, true, 11>(
6029                    Inst, Imm, Address, Decoder)))
6030       return MCDisassembler::Fail;
6031     break;
6032   case ARM::t2DLS:
6033   case ARM::MVE_DLSTP_8:
6034   case ARM::MVE_DLSTP_16:
6035   case ARM::MVE_DLSTP_32:
6036   case ARM::MVE_DLSTP_64:
6037     unsigned Rn = fieldFromInstruction(Insn, 16, 4);
6038     if (Rn == 0xF) {
6039       // Enforce all the rest of the instruction bits in LCTP, which
6040       // won't have been reliably checked based on LCTP's own tablegen
6041       // record, because we came to this decode by a roundabout route.
6042       uint32_t CanonicalLCTP = 0xF00FE001, SBZMask = 0x00300FFE;
6043       if ((Insn & ~SBZMask) != CanonicalLCTP)
6044         return MCDisassembler::Fail;   // a mandatory bit is wrong: hard fail
6045       if (Insn != CanonicalLCTP)
6046         Check(S, MCDisassembler::SoftFail); // an SBZ bit is wrong: soft fail
6047 
6048       Inst.setOpcode(ARM::MVE_LCTP);
6049     } else {
6050       Inst.addOperand(MCOperand::createReg(ARM::LR));
6051       if (!Check(S, DecoderGPRRegisterClass(Inst,
6052                                             fieldFromInstruction(Insn, 16, 4),
6053                                             Address, Decoder)))
6054         return MCDisassembler::Fail;
6055     }
6056     break;
6057   }
6058   return S;
6059 }
6060 
6061 static DecodeStatus DecodeLongShiftOperand(MCInst &Inst, unsigned Val,
6062                                            uint64_t Address,
6063                                            const void *Decoder) {
6064   DecodeStatus S = MCDisassembler::Success;
6065 
6066   if (Val == 0)
6067     Val = 32;
6068 
6069   Inst.addOperand(MCOperand::createImm(Val));
6070 
6071   return S;
6072 }
6073 
6074 static DecodeStatus DecodetGPROddRegisterClass(MCInst &Inst, unsigned RegNo,
6075                                    uint64_t Address, const void *Decoder) {
6076   if ((RegNo) + 1 > 11)
6077     return MCDisassembler::Fail;
6078 
6079   unsigned Register = GPRDecoderTable[(RegNo) + 1];
6080   Inst.addOperand(MCOperand::createReg(Register));
6081   return MCDisassembler::Success;
6082 }
6083 
6084 static DecodeStatus DecodetGPREvenRegisterClass(MCInst &Inst, unsigned RegNo,
6085                                    uint64_t Address, const void *Decoder) {
6086   if ((RegNo) > 14)
6087     return MCDisassembler::Fail;
6088 
6089   unsigned Register = GPRDecoderTable[(RegNo)];
6090   Inst.addOperand(MCOperand::createReg(Register));
6091   return MCDisassembler::Success;
6092 }
6093 
6094 static DecodeStatus
6095 DecodeGPRwithAPSR_NZCVnospRegisterClass(MCInst &Inst, unsigned RegNo,
6096                                         uint64_t Address, const void *Decoder) {
6097   if (RegNo == 15) {
6098     Inst.addOperand(MCOperand::createReg(ARM::APSR_NZCV));
6099     return MCDisassembler::Success;
6100   }
6101 
6102   unsigned Register = GPRDecoderTable[RegNo];
6103   Inst.addOperand(MCOperand::createReg(Register));
6104 
6105   if (RegNo == 13)
6106     return MCDisassembler::SoftFail;
6107 
6108   return MCDisassembler::Success;
6109 }
6110 
6111 static DecodeStatus DecodeVSCCLRM(MCInst &Inst, unsigned Insn, uint64_t Address,
6112                                   const void *Decoder) {
6113   DecodeStatus S = MCDisassembler::Success;
6114 
6115   Inst.addOperand(MCOperand::createImm(ARMCC::AL));
6116   Inst.addOperand(MCOperand::createReg(0));
6117   if (Inst.getOpcode() == ARM::VSCCLRMD) {
6118     unsigned reglist = (fieldFromInstruction(Insn, 1, 7) << 1) |
6119                        (fieldFromInstruction(Insn, 12, 4) << 8) |
6120                        (fieldFromInstruction(Insn, 22, 1) << 12);
6121     if (!Check(S, DecodeDPRRegListOperand(Inst, reglist, Address, Decoder))) {
6122       return MCDisassembler::Fail;
6123     }
6124   } else {
6125     unsigned reglist = fieldFromInstruction(Insn, 0, 8) |
6126                        (fieldFromInstruction(Insn, 22, 1) << 8) |
6127                        (fieldFromInstruction(Insn, 12, 4) << 9);
6128     if (!Check(S, DecodeSPRRegListOperand(Inst, reglist, Address, Decoder))) {
6129       return MCDisassembler::Fail;
6130     }
6131   }
6132   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6133 
6134   return S;
6135 }
6136 
6137 static DecodeStatus DecodeMQPRRegisterClass(MCInst &Inst, unsigned RegNo,
6138                               uint64_t Address,
6139                               const void *Decoder) {
6140   if (RegNo > 7)
6141     return MCDisassembler::Fail;
6142 
6143   unsigned Register = QPRDecoderTable[RegNo];
6144   Inst.addOperand(MCOperand::createReg(Register));
6145   return MCDisassembler::Success;
6146 }
6147 
6148 static const uint16_t QQPRDecoderTable[] = {
6149      ARM::Q0_Q1,  ARM::Q1_Q2,  ARM::Q2_Q3,  ARM::Q3_Q4,
6150      ARM::Q4_Q5,  ARM::Q5_Q6,  ARM::Q6_Q7
6151 };
6152 
6153 static DecodeStatus DecodeQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
6154                               uint64_t Address,
6155                               const void *Decoder) {
6156   if (RegNo > 6)
6157     return MCDisassembler::Fail;
6158 
6159   unsigned Register = QQPRDecoderTable[RegNo];
6160   Inst.addOperand(MCOperand::createReg(Register));
6161   return MCDisassembler::Success;
6162 }
6163 
6164 static const uint16_t QQQQPRDecoderTable[] = {
6165      ARM::Q0_Q1_Q2_Q3,  ARM::Q1_Q2_Q3_Q4,  ARM::Q2_Q3_Q4_Q5,
6166      ARM::Q3_Q4_Q5_Q6,  ARM::Q4_Q5_Q6_Q7
6167 };
6168 
6169 static DecodeStatus DecodeQQQQPRRegisterClass(MCInst &Inst, unsigned RegNo,
6170                               uint64_t Address,
6171                               const void *Decoder) {
6172   if (RegNo > 4)
6173     return MCDisassembler::Fail;
6174 
6175   unsigned Register = QQQQPRDecoderTable[RegNo];
6176   Inst.addOperand(MCOperand::createReg(Register));
6177   return MCDisassembler::Success;
6178 }
6179 
6180 static DecodeStatus DecodeVPTMaskOperand(MCInst &Inst, unsigned Val,
6181                                          uint64_t Address,
6182                                          const void *Decoder) {
6183   DecodeStatus S = MCDisassembler::Success;
6184 
6185   // Parse VPT mask and encode it in the MCInst as an immediate with the same
6186   // format as the it_mask.  That is, from the second 'e|t' encode 'e' as 1 and
6187   // 't' as 0 and finish with a 1.
6188   unsigned Imm = 0;
6189   // We always start with a 't'.
6190   unsigned CurBit = 0;
6191   for (int i = 3; i >= 0; --i) {
6192     // If the bit we are looking at is not the same as last one, invert the
6193     // CurBit, if it is the same leave it as is.
6194     CurBit ^= (Val >> i) & 1U;
6195 
6196     // Encode the CurBit at the right place in the immediate.
6197     Imm |= (CurBit << i);
6198 
6199     // If we are done, finish the encoding with a 1.
6200     if ((Val & ~(~0U << i)) == 0) {
6201       Imm |= 1U << i;
6202       break;
6203     }
6204   }
6205 
6206   Inst.addOperand(MCOperand::createImm(Imm));
6207 
6208   return S;
6209 }
6210 
6211 static DecodeStatus DecodeVpredROperand(MCInst &Inst, unsigned RegNo,
6212                                         uint64_t Address, const void *Decoder) {
6213   // The vpred_r operand type includes an MQPR register field derived
6214   // from the encoding. But we don't actually want to add an operand
6215   // to the MCInst at this stage, because AddThumbPredicate will do it
6216   // later, and will infer the register number from the TIED_TO
6217   // constraint. So this is a deliberately empty decoder method that
6218   // will inhibit the auto-generated disassembly code from adding an
6219   // operand at all.
6220   return MCDisassembler::Success;
6221 }
6222 
6223 static DecodeStatus DecodeRestrictedIPredicateOperand(MCInst &Inst,
6224                                                       unsigned Val,
6225                                                       uint64_t Address,
6226                                                       const void *Decoder) {
6227   Inst.addOperand(MCOperand::createImm((Val & 0x1) == 0 ? ARMCC::EQ : ARMCC::NE));
6228   return MCDisassembler::Success;
6229 }
6230 
6231 static DecodeStatus DecodeRestrictedSPredicateOperand(MCInst &Inst,
6232                                                       unsigned Val,
6233                                                       uint64_t Address,
6234                                                       const void *Decoder) {
6235   unsigned Code;
6236   switch (Val & 0x3) {
6237   case 0:
6238     Code = ARMCC::GE;
6239     break;
6240   case 1:
6241     Code = ARMCC::LT;
6242     break;
6243   case 2:
6244     Code = ARMCC::GT;
6245     break;
6246   case 3:
6247     Code = ARMCC::LE;
6248     break;
6249   }
6250   Inst.addOperand(MCOperand::createImm(Code));
6251   return MCDisassembler::Success;
6252 }
6253 
6254 static DecodeStatus DecodeRestrictedUPredicateOperand(MCInst &Inst,
6255                                                       unsigned Val,
6256                                                       uint64_t Address,
6257                                                       const void *Decoder) {
6258   Inst.addOperand(MCOperand::createImm((Val & 0x1) == 0 ? ARMCC::HS : ARMCC::HI));
6259   return MCDisassembler::Success;
6260 }
6261 
6262 static DecodeStatus DecodeRestrictedFPPredicateOperand(MCInst &Inst, unsigned Val,
6263                                                      uint64_t Address,
6264                                                      const void *Decoder) {
6265   unsigned Code;
6266   switch (Val) {
6267   default:
6268     return MCDisassembler::Fail;
6269   case 0:
6270     Code = ARMCC::EQ;
6271     break;
6272   case 1:
6273     Code = ARMCC::NE;
6274     break;
6275   case 4:
6276     Code = ARMCC::GE;
6277     break;
6278   case 5:
6279     Code = ARMCC::LT;
6280     break;
6281   case 6:
6282     Code = ARMCC::GT;
6283     break;
6284   case 7:
6285     Code = ARMCC::LE;
6286     break;
6287   }
6288 
6289   Inst.addOperand(MCOperand::createImm(Code));
6290   return MCDisassembler::Success;
6291 }
6292 
6293 static DecodeStatus DecodeVCVTImmOperand(MCInst &Inst, unsigned Val,
6294                                          uint64_t Address, const void *Decoder) {
6295   DecodeStatus S = MCDisassembler::Success;
6296 
6297   unsigned DecodedVal = 64 - Val;
6298 
6299   switch (Inst.getOpcode()) {
6300   case ARM::MVE_VCVTf16s16_fix:
6301   case ARM::MVE_VCVTs16f16_fix:
6302   case ARM::MVE_VCVTf16u16_fix:
6303   case ARM::MVE_VCVTu16f16_fix:
6304     if (DecodedVal > 16)
6305       return MCDisassembler::Fail;
6306     break;
6307   case ARM::MVE_VCVTf32s32_fix:
6308   case ARM::MVE_VCVTs32f32_fix:
6309   case ARM::MVE_VCVTf32u32_fix:
6310   case ARM::MVE_VCVTu32f32_fix:
6311     if (DecodedVal > 32)
6312       return MCDisassembler::Fail;
6313     break;
6314   }
6315 
6316   Inst.addOperand(MCOperand::createImm(64 - Val));
6317 
6318   return S;
6319 }
6320 
6321 static unsigned FixedRegForVSTRVLDR_SYSREG(unsigned Opcode) {
6322   switch (Opcode) {
6323   case ARM::VSTR_P0_off:
6324   case ARM::VSTR_P0_pre:
6325   case ARM::VSTR_P0_post:
6326   case ARM::VLDR_P0_off:
6327   case ARM::VLDR_P0_pre:
6328   case ARM::VLDR_P0_post:
6329     return ARM::P0;
6330   default:
6331     return 0;
6332   }
6333 }
6334 
6335 template<bool Writeback>
6336 static DecodeStatus DecodeVSTRVLDR_SYSREG(MCInst &Inst, unsigned Val,
6337                                           uint64_t Address,
6338                                           const void *Decoder) {
6339   switch (Inst.getOpcode()) {
6340   case ARM::VSTR_FPSCR_pre:
6341   case ARM::VSTR_FPSCR_NZCVQC_pre:
6342   case ARM::VLDR_FPSCR_pre:
6343   case ARM::VLDR_FPSCR_NZCVQC_pre:
6344   case ARM::VSTR_FPSCR_off:
6345   case ARM::VSTR_FPSCR_NZCVQC_off:
6346   case ARM::VLDR_FPSCR_off:
6347   case ARM::VLDR_FPSCR_NZCVQC_off:
6348   case ARM::VSTR_FPSCR_post:
6349   case ARM::VSTR_FPSCR_NZCVQC_post:
6350   case ARM::VLDR_FPSCR_post:
6351   case ARM::VLDR_FPSCR_NZCVQC_post:
6352     const FeatureBitset &featureBits =
6353         ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
6354 
6355     if (!featureBits[ARM::HasMVEIntegerOps] && !featureBits[ARM::FeatureVFP2])
6356       return MCDisassembler::Fail;
6357   }
6358 
6359   DecodeStatus S = MCDisassembler::Success;
6360   if (unsigned Sysreg = FixedRegForVSTRVLDR_SYSREG(Inst.getOpcode()))
6361     Inst.addOperand(MCOperand::createReg(Sysreg));
6362   unsigned Rn = fieldFromInstruction(Val, 16, 4);
6363   unsigned addr = fieldFromInstruction(Val, 0, 7) |
6364                   (fieldFromInstruction(Val, 23, 1) << 7) | (Rn << 8);
6365 
6366   if (Writeback) {
6367     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
6368       return MCDisassembler::Fail;
6369   }
6370   if (!Check(S, DecodeT2AddrModeImm7s4(Inst, addr, Address, Decoder)))
6371     return MCDisassembler::Fail;
6372 
6373   Inst.addOperand(MCOperand::createImm(ARMCC::AL));
6374   Inst.addOperand(MCOperand::createReg(0));
6375 
6376   return S;
6377 }
6378 
6379 static inline DecodeStatus DecodeMVE_MEM_pre(
6380   MCInst &Inst, unsigned Val, uint64_t Address, const void *Decoder,
6381   unsigned Rn, OperandDecoder RnDecoder, OperandDecoder AddrDecoder) {
6382   DecodeStatus S = MCDisassembler::Success;
6383 
6384   unsigned Qd = fieldFromInstruction(Val, 13, 3);
6385   unsigned addr = fieldFromInstruction(Val, 0, 7) |
6386                   (fieldFromInstruction(Val, 23, 1) << 7) | (Rn << 8);
6387 
6388   if (!Check(S, RnDecoder(Inst, Rn, Address, Decoder)))
6389     return MCDisassembler::Fail;
6390   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6391     return MCDisassembler::Fail;
6392   if (!Check(S, AddrDecoder(Inst, addr, Address, Decoder)))
6393     return MCDisassembler::Fail;
6394 
6395   return S;
6396 }
6397 
6398 template <int shift>
6399 static DecodeStatus DecodeMVE_MEM_1_pre(MCInst &Inst, unsigned Val,
6400                                         uint64_t Address, const void *Decoder) {
6401   return DecodeMVE_MEM_pre(Inst, Val, Address, Decoder,
6402                            fieldFromInstruction(Val, 16, 3),
6403                            DecodetGPRRegisterClass,
6404                            DecodeTAddrModeImm7<shift>);
6405 }
6406 
6407 template <int shift>
6408 static DecodeStatus DecodeMVE_MEM_2_pre(MCInst &Inst, unsigned Val,
6409                                         uint64_t Address, const void *Decoder) {
6410   return DecodeMVE_MEM_pre(Inst, Val, Address, Decoder,
6411                            fieldFromInstruction(Val, 16, 4),
6412                            DecoderGPRRegisterClass,
6413                            DecodeT2AddrModeImm7<shift,1>);
6414 }
6415 
6416 template <int shift>
6417 static DecodeStatus DecodeMVE_MEM_3_pre(MCInst &Inst, unsigned Val,
6418                                         uint64_t Address, const void *Decoder) {
6419   return DecodeMVE_MEM_pre(Inst, Val, Address, Decoder,
6420                            fieldFromInstruction(Val, 17, 3),
6421                            DecodeMQPRRegisterClass,
6422                            DecodeMveAddrModeQ<shift>);
6423 }
6424 
6425 template<unsigned MinLog, unsigned MaxLog>
6426 static DecodeStatus DecodePowerTwoOperand(MCInst &Inst, unsigned Val,
6427                                           uint64_t Address,
6428                                           const void *Decoder) {
6429   DecodeStatus S = MCDisassembler::Success;
6430 
6431   if (Val < MinLog || Val > MaxLog)
6432     return MCDisassembler::Fail;
6433 
6434   Inst.addOperand(MCOperand::createImm(1LL << Val));
6435   return S;
6436 }
6437 
6438 template<unsigned start>
6439 static DecodeStatus DecodeMVEPairVectorIndexOperand(MCInst &Inst, unsigned Val,
6440                                                     uint64_t Address,
6441                                                     const void *Decoder) {
6442   DecodeStatus S = MCDisassembler::Success;
6443 
6444   Inst.addOperand(MCOperand::createImm(start + Val));
6445 
6446   return S;
6447 }
6448 
6449 static DecodeStatus DecodeMVEVMOVQtoDReg(MCInst &Inst, unsigned Insn,
6450                                          uint64_t Address, const void *Decoder) {
6451   DecodeStatus S = MCDisassembler::Success;
6452   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
6453   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
6454   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
6455                  fieldFromInstruction(Insn, 13, 3));
6456   unsigned index = fieldFromInstruction(Insn, 4, 1);
6457 
6458   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
6459     return MCDisassembler::Fail;
6460   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2, Address, Decoder)))
6461     return MCDisassembler::Fail;
6462   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6463     return MCDisassembler::Fail;
6464   if (!Check(S, DecodeMVEPairVectorIndexOperand<2>(Inst, index, Address, Decoder)))
6465     return MCDisassembler::Fail;
6466   if (!Check(S, DecodeMVEPairVectorIndexOperand<0>(Inst, index, Address, Decoder)))
6467     return MCDisassembler::Fail;
6468 
6469   return S;
6470 }
6471 
6472 static DecodeStatus DecodeMVEVMOVDRegtoQ(MCInst &Inst, unsigned Insn,
6473                                          uint64_t Address, const void *Decoder) {
6474   DecodeStatus S = MCDisassembler::Success;
6475   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
6476   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
6477   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
6478                  fieldFromInstruction(Insn, 13, 3));
6479   unsigned index = fieldFromInstruction(Insn, 4, 1);
6480 
6481   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6482     return MCDisassembler::Fail;
6483   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6484     return MCDisassembler::Fail;
6485   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
6486     return MCDisassembler::Fail;
6487   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2, Address, Decoder)))
6488     return MCDisassembler::Fail;
6489   if (!Check(S, DecodeMVEPairVectorIndexOperand<2>(Inst, index, Address, Decoder)))
6490     return MCDisassembler::Fail;
6491   if (!Check(S, DecodeMVEPairVectorIndexOperand<0>(Inst, index, Address, Decoder)))
6492     return MCDisassembler::Fail;
6493 
6494   return S;
6495 }
6496 
6497 static DecodeStatus DecodeMVEOverlappingLongShift(
6498   MCInst &Inst, unsigned Insn, uint64_t Address, const void *Decoder) {
6499   DecodeStatus S = MCDisassembler::Success;
6500 
6501   unsigned RdaLo = fieldFromInstruction(Insn, 17, 3) << 1;
6502   unsigned RdaHi = fieldFromInstruction(Insn, 9, 3) << 1;
6503   unsigned Rm = fieldFromInstruction(Insn, 12, 4);
6504 
6505   if (RdaHi == 14) {
6506     // This value of RdaHi (really indicating pc, because RdaHi has to
6507     // be an odd-numbered register, so the low bit will be set by the
6508     // decode function below) indicates that we must decode as SQRSHR
6509     // or UQRSHL, which both have a single Rda register field with all
6510     // four bits.
6511     unsigned Rda = fieldFromInstruction(Insn, 16, 4);
6512 
6513     switch (Inst.getOpcode()) {
6514       case ARM::MVE_ASRLr:
6515       case ARM::MVE_SQRSHRL:
6516         Inst.setOpcode(ARM::MVE_SQRSHR);
6517         break;
6518       case ARM::MVE_LSLLr:
6519       case ARM::MVE_UQRSHLL:
6520         Inst.setOpcode(ARM::MVE_UQRSHL);
6521         break;
6522       default:
6523         llvm_unreachable("Unexpected starting opcode!");
6524     }
6525 
6526     // Rda as output parameter
6527     if (!Check(S, DecoderGPRRegisterClass(Inst, Rda, Address, Decoder)))
6528       return MCDisassembler::Fail;
6529 
6530     // Rda again as input parameter
6531     if (!Check(S, DecoderGPRRegisterClass(Inst, Rda, Address, Decoder)))
6532       return MCDisassembler::Fail;
6533 
6534     // Rm, the amount to shift by
6535     if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
6536       return MCDisassembler::Fail;
6537 
6538     if (fieldFromInstruction (Insn, 6, 3) != 4)
6539       return MCDisassembler::SoftFail;
6540 
6541     if (Rda == Rm)
6542       return MCDisassembler::SoftFail;
6543 
6544     return S;
6545   }
6546 
6547   // Otherwise, we decode as whichever opcode our caller has already
6548   // put into Inst. Those all look the same:
6549 
6550   // RdaLo,RdaHi as output parameters
6551   if (!Check(S, DecodetGPREvenRegisterClass(Inst, RdaLo, Address, Decoder)))
6552     return MCDisassembler::Fail;
6553   if (!Check(S, DecodetGPROddRegisterClass(Inst, RdaHi, Address, Decoder)))
6554     return MCDisassembler::Fail;
6555 
6556   // RdaLo,RdaHi again as input parameters
6557   if (!Check(S, DecodetGPREvenRegisterClass(Inst, RdaLo, Address, Decoder)))
6558     return MCDisassembler::Fail;
6559   if (!Check(S, DecodetGPROddRegisterClass(Inst, RdaHi, Address, Decoder)))
6560     return MCDisassembler::Fail;
6561 
6562   // Rm, the amount to shift by
6563   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
6564     return MCDisassembler::Fail;
6565 
6566   if (Inst.getOpcode() == ARM::MVE_SQRSHRL ||
6567       Inst.getOpcode() == ARM::MVE_UQRSHLL) {
6568     unsigned Saturate = fieldFromInstruction(Insn, 7, 1);
6569     // Saturate, the bit position for saturation
6570     Inst.addOperand(MCOperand::createImm(Saturate));
6571   }
6572 
6573   return S;
6574 }
6575 
6576 static DecodeStatus DecodeMVEVCVTt1fp(MCInst &Inst, unsigned Insn, uint64_t Address,
6577                                       const void *Decoder) {
6578   DecodeStatus S = MCDisassembler::Success;
6579   unsigned Qd = ((fieldFromInstruction(Insn, 22, 1) << 3) |
6580                  fieldFromInstruction(Insn, 13, 3));
6581   unsigned Qm = ((fieldFromInstruction(Insn, 5, 1) << 3) |
6582                  fieldFromInstruction(Insn, 1, 3));
6583   unsigned imm6 = fieldFromInstruction(Insn, 16, 6);
6584 
6585   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qd, Address, Decoder)))
6586     return MCDisassembler::Fail;
6587   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
6588     return MCDisassembler::Fail;
6589   if (!Check(S, DecodeVCVTImmOperand(Inst, imm6, Address, Decoder)))
6590     return MCDisassembler::Fail;
6591 
6592   return S;
6593 }
6594 
6595 template<bool scalar, OperandDecoder predicate_decoder>
6596 static DecodeStatus DecodeMVEVCMP(MCInst &Inst, unsigned Insn, uint64_t Address,
6597                                   const void *Decoder) {
6598   DecodeStatus S = MCDisassembler::Success;
6599   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6600   unsigned Qn = fieldFromInstruction(Insn, 17, 3);
6601   if (!Check(S, DecodeMQPRRegisterClass(Inst, Qn, Address, Decoder)))
6602     return MCDisassembler::Fail;
6603 
6604   unsigned fc;
6605 
6606   if (scalar) {
6607     fc = fieldFromInstruction(Insn, 12, 1) << 2 |
6608          fieldFromInstruction(Insn, 7, 1) |
6609          fieldFromInstruction(Insn, 5, 1) << 1;
6610     unsigned Rm = fieldFromInstruction(Insn, 0, 4);
6611     if (!Check(S, DecodeGPRwithZRRegisterClass(Inst, Rm, Address, Decoder)))
6612       return MCDisassembler::Fail;
6613   } else {
6614     fc = fieldFromInstruction(Insn, 12, 1) << 2 |
6615          fieldFromInstruction(Insn, 7, 1) |
6616          fieldFromInstruction(Insn, 0, 1) << 1;
6617     unsigned Qm = fieldFromInstruction(Insn, 5, 1) << 4 |
6618                   fieldFromInstruction(Insn, 1, 3);
6619     if (!Check(S, DecodeMQPRRegisterClass(Inst, Qm, Address, Decoder)))
6620       return MCDisassembler::Fail;
6621   }
6622 
6623   if (!Check(S, predicate_decoder(Inst, fc, Address, Decoder)))
6624     return MCDisassembler::Fail;
6625 
6626   Inst.addOperand(MCOperand::createImm(ARMVCC::None));
6627   Inst.addOperand(MCOperand::createReg(0));
6628   Inst.addOperand(MCOperand::createImm(0));
6629 
6630   return S;
6631 }
6632 
6633 static DecodeStatus DecodeMveVCTP(MCInst &Inst, unsigned Insn, uint64_t Address,
6634                                   const void *Decoder) {
6635   DecodeStatus S = MCDisassembler::Success;
6636   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6637   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
6638   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
6639     return MCDisassembler::Fail;
6640   return S;
6641 }
6642 
6643 static DecodeStatus DecodeMVEVPNOT(MCInst &Inst, unsigned Insn, uint64_t Address,
6644                                    const void *Decoder) {
6645   DecodeStatus S = MCDisassembler::Success;
6646   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6647   Inst.addOperand(MCOperand::createReg(ARM::VPR));
6648   return S;
6649 }
6650 
6651 static DecodeStatus DecodeT2AddSubSPImm(MCInst &Inst, unsigned Insn,
6652                                         uint64_t Address, const void *Decoder) {
6653   const unsigned Rd = fieldFromInstruction(Insn, 8, 4);
6654   const unsigned Rn = fieldFromInstruction(Insn, 16, 4);
6655   const unsigned Imm12 = fieldFromInstruction(Insn, 26, 1) << 11 |
6656                          fieldFromInstruction(Insn, 12, 3) << 8 |
6657                          fieldFromInstruction(Insn, 0, 8);
6658   const unsigned TypeT3 = fieldFromInstruction(Insn, 25, 1);
6659   unsigned sign1 = fieldFromInstruction(Insn, 21, 1);
6660   unsigned sign2 = fieldFromInstruction(Insn, 23, 1);
6661   unsigned S = fieldFromInstruction(Insn, 20, 1);
6662   if (sign1 != sign2)
6663     return MCDisassembler::Fail;
6664 
6665   // T3 does a zext of imm12, where T2 does a ThumbExpandImm (T2SOImm)
6666   DecodeStatus DS = MCDisassembler::Success;
6667   if ((!Check(DS,
6668               DecodeGPRspRegisterClass(Inst, Rd, Address, Decoder))) || // dst
6669       (!Check(DS, DecodeGPRspRegisterClass(Inst, Rn, Address, Decoder))))
6670     return MCDisassembler::Fail;
6671   if (TypeT3) {
6672     Inst.setOpcode(sign1 ? ARM::t2SUBspImm12 : ARM::t2ADDspImm12);
6673     S = 0;
6674     Inst.addOperand(MCOperand::createImm(Imm12)); // zext imm12
6675   } else {
6676     Inst.setOpcode(sign1 ? ARM::t2SUBspImm : ARM::t2ADDspImm);
6677     if (!Check(DS, DecodeT2SOImm(Inst, Imm12, Address, Decoder))) // imm12
6678       return MCDisassembler::Fail;
6679   }
6680   if (!Check(DS, DecodeCCOutOperand(Inst, S, Address, Decoder))) // cc_out
6681     return MCDisassembler::Fail;
6682 
6683   Inst.addOperand(MCOperand::createReg(0)); // pred
6684 
6685   return DS;
6686 }
6687